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@*
65 Copyright @copyright{} 2019 Josh Holland@*
66 Copyright @copyright{} 2019 Diego Nicola Barbato@*
68 Permission is granted to copy, distribute and/or modify this document
69 under the terms of the GNU Free Documentation License, Version 1.3 or
70 any later version published by the Free Software Foundation; with no
71 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
72 copy of the license is included in the section entitled ``GNU Free
73 Documentation License''.
76 @dircategory System administration
78 * Guix: (guix). Manage installed software and system configuration.
79 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
80 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
81 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
82 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
85 @dircategory Software development
87 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
88 * guix build: (guix)Invoking guix build. Building packages.
89 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
93 @title GNU Guix Reference Manual
94 @subtitle Using the GNU Guix Functional Package Manager
95 @author The GNU Guix Developers
98 @vskip 0pt plus 1filll
99 Edition @value{EDITION} @*
107 @c *********************************************************************
111 This document describes GNU Guix version @value{VERSION}, a functional
112 package management tool written for the GNU system.
114 @c TRANSLATORS: You can replace the following paragraph with information on
115 @c how to join your own translation team and how to report issues with the
117 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
118 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
119 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
120 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
121 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
122 would like to translate it in your native language, consider joining the
123 @uref{https://translationproject.org/domain/guix-manual.html, Translation
127 * Introduction:: What is Guix about?
128 * Installation:: Installing Guix.
129 * System Installation:: Installing the whole operating system.
130 * Package Management:: Package installation, upgrade, etc.
131 * Development:: Guix-aided software development.
132 * Programming Interface:: Using Guix in Scheme.
133 * Utilities:: Package management commands.
134 * System Configuration:: Configuring the operating system.
135 * Documentation:: Browsing software user manuals.
136 * Installing Debugging Files:: Feeding the debugger.
137 * Security Updates:: Deploying security fixes quickly.
138 * Bootstrapping:: GNU/Linux built from scratch.
139 * Porting:: Targeting another platform or kernel.
140 * Contributing:: Your help needed!
142 * Acknowledgments:: Thanks!
143 * GNU Free Documentation License:: The license of this manual.
144 * Concept Index:: Concepts.
145 * Programming Index:: Data types, functions, and variables.
148 --- The Detailed Node Listing ---
152 * Managing Software the Guix Way:: What's special.
153 * GNU Distribution:: The packages and tools.
157 * Binary Installation:: Getting Guix running in no time!
158 * Requirements:: Software needed to build and run Guix.
159 * Running the Test Suite:: Testing Guix.
160 * Setting Up the Daemon:: Preparing the build daemon's environment.
161 * Invoking guix-daemon:: Running the build daemon.
162 * Application Setup:: Application-specific setup.
164 Setting Up the Daemon
166 * Build Environment Setup:: Preparing the isolated build environment.
167 * Daemon Offload Setup:: Offloading builds to remote machines.
168 * SELinux Support:: Using an SELinux policy for the daemon.
172 * Limitations:: What you can expect.
173 * Hardware Considerations:: Supported hardware.
174 * USB Stick and DVD Installation:: Preparing the installation medium.
175 * Preparing for Installation:: Networking, partitioning, etc.
176 * Guided Graphical Installation:: Easy graphical installation.
177 * Manual Installation:: Manual installation for wizards.
178 * After System Installation:: When installation succeeded.
179 * Installing Guix in a VM:: Guix System playground.
180 * Building the Installation Image:: How this comes to be.
184 * Keyboard Layout and Networking and Partitioning:: Initial setup.
185 * Proceeding with the Installation:: Installing.
189 * Features:: How Guix will make your life brighter.
190 * Invoking guix package:: Package installation, removal, etc.
191 * Substitutes:: Downloading pre-built binaries.
192 * Packages with Multiple Outputs:: Single source package, multiple outputs.
193 * Invoking guix gc:: Running the garbage collector.
194 * Invoking guix pull:: Fetching the latest Guix and distribution.
195 * Channels:: Customizing the package collection.
196 * Inferiors:: Interacting with another revision of Guix.
197 * Invoking guix describe:: Display information about your Guix revision.
198 * Invoking guix archive:: Exporting and importing store files.
202 * Official Substitute Server:: One particular source of substitutes.
203 * Substitute Server Authorization:: How to enable or disable substitutes.
204 * Substitute Authentication:: How Guix verifies substitutes.
205 * Proxy Settings:: How to get substitutes via proxy.
206 * Substitution Failure:: What happens when substitution fails.
207 * On Trusting Binaries:: How can you trust that binary blob?
211 * Invoking guix environment:: Setting up development environments.
212 * Invoking guix pack:: Creating software bundles.
214 Programming Interface
216 * Package Modules:: Packages from the programmer's viewpoint.
217 * Defining Packages:: Defining new packages.
218 * Build Systems:: Specifying how packages are built.
219 * The Store:: Manipulating the package store.
220 * Derivations:: Low-level interface to package derivations.
221 * The Store Monad:: Purely functional interface to the store.
222 * G-Expressions:: Manipulating build expressions.
223 * Invoking guix repl:: Fiddling with Guix interactively.
227 * package Reference:: The package data type.
228 * origin Reference:: The origin data type.
232 * Invoking guix build:: Building packages from the command line.
233 * Invoking guix edit:: Editing package definitions.
234 * Invoking guix download:: Downloading a file and printing its hash.
235 * Invoking guix hash:: Computing the cryptographic hash of a file.
236 * Invoking guix import:: Importing package definitions.
237 * Invoking guix refresh:: Updating package definitions.
238 * Invoking guix lint:: Finding errors in package definitions.
239 * Invoking guix size:: Profiling disk usage.
240 * Invoking guix graph:: Visualizing the graph of packages.
241 * Invoking guix publish:: Sharing substitutes.
242 * Invoking guix challenge:: Challenging substitute servers.
243 * Invoking guix copy:: Copying to and from a remote store.
244 * Invoking guix container:: Process isolation.
245 * Invoking guix weather:: Assessing substitute availability.
246 * Invoking guix processes:: Listing client processes.
248 Invoking @command{guix build}
250 * Common Build Options:: Build options for most commands.
251 * Package Transformation Options:: Creating variants of packages.
252 * Additional Build Options:: Options specific to 'guix build'.
253 * Debugging Build Failures:: Real life packaging experience.
257 * Using the Configuration System:: Customizing your GNU system.
258 * operating-system Reference:: Detail of operating-system declarations.
259 * File Systems:: Configuring file system mounts.
260 * Mapped Devices:: Block device extra processing.
261 * User Accounts:: Specifying user accounts.
262 * Keyboard Layout:: How the system interprets key strokes.
263 * Locales:: Language and cultural convention settings.
264 * Services:: Specifying system services.
265 * Setuid Programs:: Programs running with root privileges.
266 * X.509 Certificates:: Authenticating HTTPS servers.
267 * Name Service Switch:: Configuring libc's name service switch.
268 * Initial RAM Disk:: Linux-Libre bootstrapping.
269 * Bootloader Configuration:: Configuring the boot loader.
270 * Invoking guix system:: Instantiating a system configuration.
271 * Running Guix in a VM:: How to run Guix System in a virtual machine.
272 * Defining Services:: Adding new service definitions.
276 * Base Services:: Essential system services.
277 * Scheduled Job Execution:: The mcron service.
278 * Log Rotation:: The rottlog service.
279 * Networking Services:: Network setup, SSH daemon, etc.
280 * X Window:: Graphical display.
281 * Printing Services:: Local and remote printer support.
282 * Desktop Services:: D-Bus and desktop services.
283 * Sound Services:: ALSA and Pulseaudio services.
284 * Database Services:: SQL databases, key-value stores, etc.
285 * Mail Services:: IMAP, POP3, SMTP, and all that.
286 * Messaging Services:: Messaging services.
287 * Telephony Services:: Telephony services.
288 * Monitoring Services:: Monitoring services.
289 * Kerberos Services:: Kerberos services.
290 * Web Services:: Web servers.
291 * Certificate Services:: TLS certificates via Let's Encrypt.
292 * DNS Services:: DNS daemons.
293 * VPN Services:: VPN daemons.
294 * Network File System:: NFS related services.
295 * Continuous Integration:: The Cuirass service.
296 * Power Management Services:: Extending battery life.
297 * Audio Services:: The MPD.
298 * Virtualization Services:: Virtualization services.
299 * Version Control Services:: Providing remote access to Git repositories.
300 * Game Services:: Game servers.
301 * Miscellaneous Services:: Other services.
305 * Service Composition:: The model for composing services.
306 * Service Types and Services:: Types and services.
307 * Service Reference:: API reference.
308 * Shepherd Services:: A particular type of service.
313 @c *********************************************************************
315 @chapter Introduction
318 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
319 using the international phonetic alphabet (IPA).} is a package
320 management tool for and distribution of the GNU system.
321 Guix makes it easy for unprivileged
322 users to install, upgrade, or remove software packages, to roll back to a
323 previous package set, to build packages from source, and generally
324 assists with the creation and maintenance of software environments.
327 @cindex GuixSD, now Guix System
328 @cindex Guix System Distribution, now Guix System
329 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
330 complements the available tools without interference (@pxref{Installation}),
331 or you can use it as a standalone operating system distribution,
332 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
333 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
334 group everything under the ``Guix'' banner since, after all, Guix System is
335 readily available through the @command{guix system} command, even if you're
336 using a different distro underneath!}. @xref{GNU Distribution}.
339 * Managing Software the Guix Way:: What's special.
340 * GNU Distribution:: The packages and tools.
343 @node Managing Software the Guix Way
344 @section Managing Software the Guix Way
346 @cindex user interfaces
347 Guix provides a command-line package management interface
348 (@pxref{Package Management}), tools to help with software development
349 (@pxref{Development}), command-line utilities for more advanced usage,
350 (@pxref{Utilities}), as well as Scheme programming interfaces
351 (@pxref{Programming Interface}).
353 Its @dfn{build daemon} is responsible for building packages on behalf of
354 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
355 binaries from authorized sources (@pxref{Substitutes}).
357 @cindex extensibility of the distribution
358 @cindex customization, of packages
359 Guix includes package definitions for many GNU and non-GNU packages, all
360 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
361 user's computing freedom}. It is @emph{extensible}: users can write
362 their own package definitions (@pxref{Defining Packages}) and make them
363 available as independent package modules (@pxref{Package Modules}). It
364 is also @emph{customizable}: users can @emph{derive} specialized package
365 definitions from existing ones, including from the command line
366 (@pxref{Package Transformation Options}).
368 @cindex functional package management
370 Under the hood, Guix implements the @dfn{functional package management}
371 discipline pioneered by Nix (@pxref{Acknowledgments}).
372 In Guix, the package build and installation process is seen
373 as a @emph{function}, in the mathematical sense. That function takes inputs,
374 such as build scripts, a compiler, and libraries, and
375 returns an installed package. As a pure function, its result depends
376 solely on its inputs---for instance, it cannot refer to software or
377 scripts that were not explicitly passed as inputs. A build function
378 always produces the same result when passed a given set of inputs. It
379 cannot alter the environment of the running system in
380 any way; for instance, it cannot create, modify, or delete files outside
381 of its build and installation directories. This is achieved by running
382 build processes in isolated environments (or @dfn{containers}), where only their
383 explicit inputs are visible.
386 The result of package build functions is @dfn{cached} in the file
387 system, in a special directory called @dfn{the store} (@pxref{The
388 Store}). Each package is installed in a directory of its own in the
389 store---by default under @file{/gnu/store}. The directory name contains
390 a hash of all the inputs used to build that package; thus, changing an
391 input yields a different directory name.
393 This approach is the foundation for the salient features of Guix: support
394 for transactional package upgrade and rollback, per-user installation, and
395 garbage collection of packages (@pxref{Features}).
398 @node GNU Distribution
399 @section GNU Distribution
402 Guix comes with a distribution of the GNU system consisting entirely of
403 free software@footnote{The term ``free'' here refers to the
404 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
405 users of that software}.}. The
406 distribution can be installed on its own (@pxref{System Installation}),
407 but it is also possible to install Guix as a package manager on top of
408 an installed GNU/Linux system (@pxref{Installation}). When we need to
409 distinguish between the two, we refer to the standalone distribution as
412 The distribution provides core GNU packages such as GNU libc, GCC, and
413 Binutils, as well as many GNU and non-GNU applications. The complete
414 list of available packages can be browsed
415 @url{https://www.gnu.org/software/guix/packages,on-line} or by
416 running @command{guix package} (@pxref{Invoking guix package}):
419 guix package --list-available
422 Our goal is to provide a practical 100% free software distribution of
423 Linux-based and other variants of GNU, with a focus on the promotion and
424 tight integration of GNU components, and an emphasis on programs and
425 tools that help users exert that freedom.
427 Packages are currently available on the following platforms:
432 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
435 Intel 32-bit architecture (IA32), Linux-Libre kernel;
438 ARMv7-A architecture with hard float, Thumb-2 and NEON,
439 using the EABI hard-float application binary interface (ABI),
440 and Linux-Libre kernel.
443 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
446 little-endian 64-bit MIPS processors, specifically the Loongson series,
447 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
448 supported; in particular, the project's build farms no longer provide
449 substitutes for this architecture.
453 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
454 configuration and Guix takes care of instantiating the configuration in a
455 transactional, reproducible, and stateless fashion (@pxref{System
456 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
457 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
458 Manual}), the well-known GNU utilities and tool chain, as well as the
459 graphical environment or system services of your choice.
461 Guix System is available on all the above platforms except
462 @code{mips64el-linux}.
465 For information on porting to other architectures or kernels,
468 Building this distribution is a cooperative effort, and you are invited
469 to join! @xref{Contributing}, for information about how you can help.
472 @c *********************************************************************
474 @chapter Installation
476 @cindex installing Guix
479 We recommend the use of this
480 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
481 shell installer script} to install Guix on top of a running GNU/Linux system,
482 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
483 with the installation of the package manager, which can be done on top of a
484 running GNU/Linux system. If, instead, you want to install the complete GNU
485 operating system, @pxref{System Installation}.} The script automates the
486 download, installation, and initial configuration of Guix. It should be run
490 @cindex foreign distro
491 @cindex directories related to foreign distro
492 When installed on a foreign distro, GNU@tie{}Guix complements the available
493 tools without interference. Its data lives exclusively in two directories,
494 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
495 such as @file{/etc}, are left untouched.
497 Once installed, Guix can be updated by running @command{guix pull}
498 (@pxref{Invoking guix pull}).
500 If you prefer to perform the installation steps manually or want to tweak
501 them, you may find the following subsections useful. They describe the
502 software requirements of Guix, as well as how to install it manually and get
506 * Binary Installation:: Getting Guix running in no time!
507 * Requirements:: Software needed to build and run Guix.
508 * Running the Test Suite:: Testing Guix.
509 * Setting Up the Daemon:: Preparing the build daemon's environment.
510 * Invoking guix-daemon:: Running the build daemon.
511 * Application Setup:: Application-specific setup.
514 @node Binary Installation
515 @section Binary Installation
517 @cindex installing Guix from binaries
518 @cindex installer script
519 This section describes how to install Guix on an arbitrary system from a
520 self-contained tarball providing binaries for Guix and for all its
521 dependencies. This is often quicker than installing from source, which
522 is described in the next sections. The only requirement is to have
525 @c Note duplicated from the ``Installation'' node.
527 We recommend the use of this
528 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
529 shell installer script}. The script automates the download, installation, and
530 initial configuration steps described below. It should be run as the root
534 Installing goes along these lines:
538 @cindex downloading Guix binary
539 Download the binary tarball from
540 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz},
541 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
542 already running the kernel Linux, and so on.
544 @c The following is somewhat duplicated in ``System Installation''.
545 Make sure to download the associated @file{.sig} file and to verify the
546 authenticity of the tarball against it, along these lines:
549 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
550 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
553 If that command fails because you do not have the required public key,
554 then run this command to import it:
557 $ gpg --keyserver @value{KEY-SERVER} \
558 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
562 and rerun the @code{gpg --verify} command.
563 @c end authentication part
566 Now, you need to become the @code{root} user. Depending on your distribution,
567 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
571 # tar --warning=no-timestamp -xf \
572 guix-binary-@value{VERSION}.@var{system}.tar.xz
573 # mv var/guix /var/ && mv gnu /
576 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
577 The latter contains a ready-to-use profile for @code{root} (see next
580 Do @emph{not} unpack the tarball on a working Guix system since that
581 would overwrite its own essential files.
583 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
584 not emit warnings about ``implausibly old time stamps'' (such
585 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
587 They stem from the fact that all the
588 files in the archive have their modification time set to zero (which
589 means January 1st, 1970.) This is done on purpose to make sure the
590 archive content is independent of its creation time, thus making it
594 Make the profile available under @file{~root/.config/guix/current}, which is
595 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
598 # mkdir -p ~root/.config/guix
599 # ln -sf /var/guix/profiles/per-user/root/current-guix \
600 ~root/.config/guix/current
603 Source @file{etc/profile} to augment @code{PATH} and other relevant
604 environment variables:
607 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
608 source $GUIX_PROFILE/etc/profile
612 Create the group and user accounts for build users as explained below
613 (@pxref{Build Environment Setup}).
616 Run the daemon, and set it to automatically start on boot.
618 If your host distro uses the systemd init system, this can be achieved
621 @c Versions of systemd that supported symlinked service files are not
622 @c yet widely deployed, so we should suggest that users copy the service
625 @c See this thread for more information:
626 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
629 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
631 # systemctl start guix-daemon && systemctl enable guix-daemon
634 If your host distro uses the Upstart init system:
637 # initctl reload-configuration
638 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
643 Otherwise, you can still start the daemon manually with:
646 # ~root/.config/guix/current/bin/guix-daemon \
647 --build-users-group=guixbuild
651 Make the @command{guix} command available to other users on the machine,
655 # mkdir -p /usr/local/bin
657 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
660 It is also a good idea to make the Info version of this manual available
664 # mkdir -p /usr/local/share/info
665 # cd /usr/local/share/info
666 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
670 That way, assuming @file{/usr/local/share/info} is in the search path,
671 running @command{info guix} will open this manual (@pxref{Other Info
672 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
676 @cindex substitutes, authorization thereof
677 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
678 (@pxref{Substitutes}), authorize them:
681 # guix archive --authorize < \
682 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
686 Each user may need to perform a few additional steps to make their Guix
687 environment ready for use, @pxref{Application Setup}.
690 Voilà, the installation is complete!
692 You can confirm that Guix is working by installing a sample package into
699 The binary installation tarball can be (re)produced and verified simply
700 by running the following command in the Guix source tree:
703 make guix-binary.@var{system}.tar.xz
707 ...@: which, in turn, runs:
710 guix pack -s @var{system} --localstatedir \
711 --profile-name=current-guix guix
714 @xref{Invoking guix pack}, for more info on this handy tool.
717 @section Requirements
719 This section lists requirements when building Guix from source. The
720 build procedure for Guix is the same as for other GNU software, and is
721 not covered here. Please see the files @file{README} and @file{INSTALL}
722 in the Guix source tree for additional details.
724 @cindex official website
725 GNU Guix is available for download from its website at
726 @url{https://www.gnu.org/software/guix/}.
728 GNU Guix depends on the following packages:
731 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 2.2.x;
732 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
735 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
736 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
737 Guile,, gnutls-guile, GnuTLS-Guile});
739 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
742 @c FIXME: Specify a version number once a release has been made.
743 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
745 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON};
746 @item @url{https://zlib.net, zlib};
747 @item @url{https://www.gnu.org/software/make/, GNU Make}.
750 The following dependencies are optional:
754 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
755 Support for build offloading (@pxref{Daemon Offload Setup}) and
756 @command{guix copy} (@pxref{Invoking guix copy}) depends on
757 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
758 version 0.10.2 or later.
761 When @url{http://www.bzip.org, libbz2} is available,
762 @command{guix-daemon} can use it to compress build logs.
765 Unless @code{--disable-daemon} was passed to @command{configure}, the
766 following packages are also needed:
769 @item @url{https://gnupg.org/, GNU libgcrypt};
770 @item @url{https://sqlite.org, SQLite 3};
771 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
775 @cindex state directory
776 When configuring Guix on a system that already has a Guix installation,
777 be sure to specify the same state directory as the existing installation
778 using the @code{--localstatedir} option of the @command{configure}
779 script (@pxref{Directory Variables, @code{localstatedir},, standards,
780 GNU Coding Standards}). The @command{configure} script protects against
781 unintended misconfiguration of @var{localstatedir} so you do not
782 inadvertently corrupt your store (@pxref{The Store}).
784 @cindex Nix, compatibility
785 When a working installation of @url{https://nixos.org/nix/, the Nix package
786 manager} is available, you
787 can instead configure Guix with @code{--disable-daemon}. In that case,
788 Nix replaces the three dependencies above.
790 Guix is compatible with Nix, so it is possible to share the same store
791 between both. To do so, you must pass @command{configure} not only the
792 same @code{--with-store-dir} value, but also the same
793 @code{--localstatedir} value. The latter is essential because it
794 specifies where the database that stores metadata about the store is
795 located, among other things. The default values for Nix are
796 @code{--with-store-dir=/nix/store} and @code{--localstatedir=/nix/var}.
797 Note that @code{--disable-daemon} is not required if
798 your goal is to share the store with Nix.
800 @node Running the Test Suite
801 @section Running the Test Suite
804 After a successful @command{configure} and @code{make} run, it is a good
805 idea to run the test suite. It can help catch issues with the setup or
806 environment, or bugs in Guix itself---and really, reporting test
807 failures is a good way to help improve the software. To run the test
814 Test cases can run in parallel: you can use the @code{-j} option of
815 GNU@tie{}make to speed things up. The first run may take a few minutes
816 on a recent machine; subsequent runs will be faster because the store
817 that is created for test purposes will already have various things in
820 It is also possible to run a subset of the tests by defining the
821 @code{TESTS} makefile variable as in this example:
824 make check TESTS="tests/store.scm tests/cpio.scm"
827 By default, tests results are displayed at a file level. In order to
828 see the details of every individual test cases, it is possible to define
829 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
832 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
835 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
836 @file{test-suite.log} file. Please specify the Guix version being used
837 as well as version numbers of the dependencies (@pxref{Requirements}) in
840 Guix also comes with a whole-system test suite that tests complete
841 Guix System instances. It can only run on systems where
842 Guix is already installed, using:
849 or, again, by defining @code{TESTS} to select a subset of tests to run:
852 make check-system TESTS="basic mcron"
855 These system tests are defined in the @code{(gnu tests @dots{})}
856 modules. They work by running the operating systems under test with
857 lightweight instrumentation in a virtual machine (VM). They can be
858 computationally intensive or rather cheap, depending on whether
859 substitutes are available for their dependencies (@pxref{Substitutes}).
860 Some of them require a lot of storage space to hold VM images.
862 Again in case of test failures, please send @email{bug-guix@@gnu.org}
865 @node Setting Up the Daemon
866 @section Setting Up the Daemon
869 Operations such as building a package or running the garbage collector
870 are all performed by a specialized process, the @dfn{build daemon}, on
871 behalf of clients. Only the daemon may access the store and its
872 associated database. Thus, any operation that manipulates the store
873 goes through the daemon. For instance, command-line tools such as
874 @command{guix package} and @command{guix build} communicate with the
875 daemon (@i{via} remote procedure calls) to instruct it what to do.
877 The following sections explain how to prepare the build daemon's
878 environment. See also @ref{Substitutes}, for information on how to allow
879 the daemon to download pre-built binaries.
882 * Build Environment Setup:: Preparing the isolated build environment.
883 * Daemon Offload Setup:: Offloading builds to remote machines.
884 * SELinux Support:: Using an SELinux policy for the daemon.
887 @node Build Environment Setup
888 @subsection Build Environment Setup
890 @cindex build environment
891 In a standard multi-user setup, Guix and its daemon---the
892 @command{guix-daemon} program---are installed by the system
893 administrator; @file{/gnu/store} is owned by @code{root} and
894 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
895 Guix tools to build packages or otherwise access the store, and the
896 daemon will do it on their behalf, ensuring that the store is kept in a
897 consistent state, and allowing built packages to be shared among users.
900 When @command{guix-daemon} runs as @code{root}, you may not want package
901 build processes themselves to run as @code{root} too, for obvious
902 security reasons. To avoid that, a special pool of @dfn{build users}
903 should be created for use by build processes started by the daemon.
904 These build users need not have a shell and a home directory: they will
905 just be used when the daemon drops @code{root} privileges in build
906 processes. Having several such users allows the daemon to launch
907 distinct build processes under separate UIDs, which guarantees that they
908 do not interfere with each other---an essential feature since builds are
909 regarded as pure functions (@pxref{Introduction}).
911 On a GNU/Linux system, a build user pool may be created like this (using
912 Bash syntax and the @code{shadow} commands):
914 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
915 @c for why `-G' is needed.
917 # groupadd --system guixbuild
918 # for i in `seq -w 1 10`;
920 useradd -g guixbuild -G guixbuild \
921 -d /var/empty -s `which nologin` \
922 -c "Guix build user $i" --system \
928 The number of build users determines how many build jobs may run in
929 parallel, as specified by the @option{--max-jobs} option
930 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
931 @command{guix system vm} and related commands, you may need to add the
932 build users to the @code{kvm} group so they can access @file{/dev/kvm},
933 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
934 (@pxref{Invoking guix system}).
936 The @code{guix-daemon} program may then be run as @code{root} with the
937 following command@footnote{If your machine uses the systemd init system,
938 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
939 file in @file{/etc/systemd/system} will ensure that
940 @command{guix-daemon} is automatically started. Similarly, if your
941 machine uses the Upstart init system, drop the
942 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
943 file in @file{/etc/init}.}:
946 # guix-daemon --build-users-group=guixbuild
951 This way, the daemon starts build processes in a chroot, under one of
952 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
953 environment contains nothing but:
955 @c Keep this list in sync with libstore/build.cc! -----------------------
958 a minimal @code{/dev} directory, created mostly independently from the
959 host @code{/dev}@footnote{``Mostly'', because while the set of files
960 that appear in the chroot's @code{/dev} is fixed, most of these files
961 can only be created if the host has them.};
964 the @code{/proc} directory; it only shows the processes of the container
965 since a separate PID name space is used;
968 @file{/etc/passwd} with an entry for the current user and an entry for
972 @file{/etc/group} with an entry for the user's group;
975 @file{/etc/hosts} with an entry that maps @code{localhost} to
979 a writable @file{/tmp} directory.
982 You can influence the directory where the daemon stores build trees
983 @i{via} the @code{TMPDIR} environment variable. However, the build tree
984 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
985 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
986 This way, the value of @code{TMPDIR} does not leak inside build
987 environments, which avoids discrepancies in cases where build processes
988 capture the name of their build tree.
991 The daemon also honors the @code{http_proxy} environment variable for
992 HTTP downloads it performs, be it for fixed-output derivations
993 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
995 If you are installing Guix as an unprivileged user, it is still possible
996 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
997 However, build processes will not be isolated from one another, and not
998 from the rest of the system. Thus, build processes may interfere with
999 each other, and may access programs, libraries, and other files
1000 available on the system---making it much harder to view them as
1001 @emph{pure} functions.
1004 @node Daemon Offload Setup
1005 @subsection Using the Offload Facility
1009 When desired, the build daemon can @dfn{offload} derivation builds to
1010 other machines running Guix, using the @code{offload} @dfn{build
1011 hook}@footnote{This feature is available only when
1012 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1013 present.}. When that
1014 feature is enabled, a list of user-specified build machines is read from
1015 @file{/etc/guix/machines.scm}; every time a build is requested, for
1016 instance via @code{guix build}, the daemon attempts to offload it to one
1017 of the machines that satisfy the constraints of the derivation, in
1018 particular its system type---e.g., @file{x86_64-linux}. Missing
1019 prerequisites for the build are copied over SSH to the target machine,
1020 which then proceeds with the build; upon success the output(s) of the
1021 build are copied back to the initial machine.
1023 The @file{/etc/guix/machines.scm} file typically looks like this:
1026 (list (build-machine
1027 (name "eightysix.example.org")
1028 (system "x86_64-linux")
1029 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1031 (speed 2.)) ;incredibly fast!
1034 (name "meeps.example.org")
1035 (system "mips64el-linux")
1036 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1039 (string-append (getenv "HOME")
1040 "/.ssh/identity-for-guix"))))
1044 In the example above we specify a list of two build machines, one for
1045 the @code{x86_64} architecture and one for the @code{mips64el}
1048 In fact, this file is---not surprisingly!---a Scheme file that is
1049 evaluated when the @code{offload} hook is started. Its return value
1050 must be a list of @code{build-machine} objects. While this example
1051 shows a fixed list of build machines, one could imagine, say, using
1052 DNS-SD to return a list of potential build machines discovered in the
1053 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1054 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1057 @deftp {Data Type} build-machine
1058 This data type represents build machines to which the daemon may offload
1059 builds. The important fields are:
1064 The host name of the remote machine.
1067 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1070 The user account to use when connecting to the remote machine over SSH.
1071 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1072 allow non-interactive logins.
1075 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1076 This is used to authenticate the machine when we connect to it. It is a
1077 long string that looks like this:
1080 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1083 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1084 key can be found in a file such as
1085 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1087 If the machine is running the SSH daemon of GNU@tie{}lsh,
1088 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1089 similar file. It can be converted to the OpenSSH format using
1090 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1093 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1094 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1099 A number of optional fields may be specified:
1103 @item @code{port} (default: @code{22})
1104 Port number of SSH server on the machine.
1106 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1107 The SSH private key file to use when connecting to the machine, in
1108 OpenSSH format. This key must not be protected with a passphrase.
1110 Note that the default value is the private key @emph{of the root
1111 account}. Make sure it exists if you use the default.
1113 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1114 @itemx @code{compression-level} (default: @code{3})
1115 The SSH-level compression methods and compression level requested.
1117 Note that offloading relies on SSH compression to reduce bandwidth usage
1118 when transferring files to and from build machines.
1120 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1121 File name of the Unix-domain socket @command{guix-daemon} is listening
1124 @item @code{parallel-builds} (default: @code{1})
1125 The number of builds that may run in parallel on the machine.
1127 @item @code{speed} (default: @code{1.0})
1128 A ``relative speed factor''. The offload scheduler will tend to prefer
1129 machines with a higher speed factor.
1131 @item @code{features} (default: @code{'()})
1132 A list of strings denoting specific features supported by the machine.
1133 An example is @code{"kvm"} for machines that have the KVM Linux modules
1134 and corresponding hardware support. Derivations can request features by
1135 name, and they will be scheduled on matching build machines.
1140 The @command{guix} command must be in the search path on the build
1141 machines. You can check whether this is the case by running:
1144 ssh build-machine guix repl --version
1147 There is one last thing to do once @file{machines.scm} is in place. As
1148 explained above, when offloading, files are transferred back and forth
1149 between the machine stores. For this to work, you first need to
1150 generate a key pair on each machine to allow the daemon to export signed
1151 archives of files from the store (@pxref{Invoking guix archive}):
1154 # guix archive --generate-key
1158 Each build machine must authorize the key of the master machine so that
1159 it accepts store items it receives from the master:
1162 # guix archive --authorize < master-public-key.txt
1166 Likewise, the master machine must authorize the key of each build machine.
1168 All the fuss with keys is here to express pairwise mutual trust
1169 relations between the master and the build machines. Concretely, when
1170 the master receives files from a build machine (and @i{vice versa}), its
1171 build daemon can make sure they are genuine, have not been tampered
1172 with, and that they are signed by an authorized key.
1174 @cindex offload test
1175 To test whether your setup is operational, run this command on the
1182 This will attempt to connect to each of the build machines specified in
1183 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1184 available on each machine, attempt to export to the machine and import
1185 from it, and report any error in the process.
1187 If you want to test a different machine file, just specify it on the
1191 # guix offload test machines-qualif.scm
1194 Last, you can test the subset of the machines whose name matches a
1195 regular expression like this:
1198 # guix offload test machines.scm '\.gnu\.org$'
1201 @cindex offload status
1202 To display the current load of all build hosts, run this command on the
1206 # guix offload status
1210 @node SELinux Support
1211 @subsection SELinux Support
1213 @cindex SELinux, daemon policy
1214 @cindex mandatory access control, SELinux
1215 @cindex security, guix-daemon
1216 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1217 can be installed on a system where SELinux is enabled, in order to label
1218 Guix files and to specify the expected behavior of the daemon. Since
1219 Guix System does not provide an SELinux base policy, the daemon policy cannot
1220 be used on Guix System.
1222 @subsubsection Installing the SELinux policy
1223 @cindex SELinux, policy installation
1224 To install the policy run this command as root:
1227 semodule -i etc/guix-daemon.cil
1230 Then relabel the file system with @code{restorecon} or by a different
1231 mechanism provided by your system.
1233 Once the policy is installed, the file system has been relabeled, and
1234 the daemon has been restarted, it should be running in the
1235 @code{guix_daemon_t} context. You can confirm this with the following
1239 ps -Zax | grep guix-daemon
1242 Monitor the SELinux log files as you run a command like @code{guix build
1243 hello} to convince yourself that SELinux permits all necessary
1246 @subsubsection Limitations
1247 @cindex SELinux, limitations
1249 This policy is not perfect. Here is a list of limitations or quirks
1250 that should be considered when deploying the provided SELinux policy for
1255 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1256 operations involve contexts that have anything to do with
1257 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1258 but it would be preferrable to define socket rules for only this label.
1261 @code{guix gc} cannot access arbitrary links to profiles. By design,
1262 the file label of the destination of a symlink is independent of the
1263 file label of the link itself. Although all profiles under
1264 $localstatedir are labelled, the links to these profiles inherit the
1265 label of the directory they are in. For links in the user’s home
1266 directory this will be @code{user_home_t}. But for links from the root
1267 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1268 directory, etc, this won’t work. @code{guix gc} would be prevented from
1269 reading and following these links.
1272 The daemon’s feature to listen for TCP connections might no longer work.
1273 This might require extra rules, because SELinux treats network sockets
1274 differently from files.
1277 Currently all files with a name matching the regular expression
1278 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1279 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1280 that name in any profile would be permitted to run in the
1281 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1282 build a package that provides this executable and convince a user to
1283 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1284 At that point SELinux could not prevent it from accessing files that are
1285 allowed for processes in that domain.
1287 We could generate a much more restrictive policy at installation time,
1288 so that only the @emph{exact} file name of the currently installed
1289 @code{guix-daemon} executable would be labelled with
1290 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1291 The downside is that root would have to install or upgrade the policy at
1292 installation time whenever the Guix package that provides the
1293 effectively running @code{guix-daemon} executable is upgraded.
1296 @node Invoking guix-daemon
1297 @section Invoking @command{guix-daemon}
1299 The @command{guix-daemon} program implements all the functionality to
1300 access the store. This includes launching build processes, running the
1301 garbage collector, querying the availability of a build result, etc. It
1302 is normally run as @code{root} like this:
1305 # guix-daemon --build-users-group=guixbuild
1309 For details on how to set it up, @pxref{Setting Up the Daemon}.
1312 @cindex container, build environment
1313 @cindex build environment
1314 @cindex reproducible builds
1315 By default, @command{guix-daemon} launches build processes under
1316 different UIDs, taken from the build group specified with
1317 @code{--build-users-group}. In addition, each build process is run in a
1318 chroot environment that only contains the subset of the store that the
1319 build process depends on, as specified by its derivation
1320 (@pxref{Programming Interface, derivation}), plus a set of specific
1321 system directories. By default, the latter contains @file{/dev} and
1322 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1323 @dfn{container}: in addition to having its own file system tree, it has
1324 a separate mount name space, its own PID name space, network name space,
1325 etc. This helps achieve reproducible builds (@pxref{Features}).
1327 When the daemon performs a build on behalf of the user, it creates a
1328 build directory under @file{/tmp} or under the directory specified by
1329 its @code{TMPDIR} environment variable. This directory is shared with
1330 the container for the duration of the build, though within the container,
1331 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1333 The build directory is automatically deleted upon completion, unless the
1334 build failed and the client specified @option{--keep-failed}
1335 (@pxref{Invoking guix build, @option{--keep-failed}}).
1337 The daemon listens for connections and spawns one sub-process for each session
1338 started by a client (one of the @command{guix} sub-commands.) The
1339 @command{guix processes} command allows you to get an overview of the activity
1340 on your system by viewing each of the active sessions and clients.
1341 @xref{Invoking guix processes}, for more information.
1343 The following command-line options are supported:
1346 @item --build-users-group=@var{group}
1347 Take users from @var{group} to run build processes (@pxref{Setting Up
1348 the Daemon, build users}).
1350 @item --no-substitutes
1352 Do not use substitutes for build products. That is, always build things
1353 locally instead of allowing downloads of pre-built binaries
1354 (@pxref{Substitutes}).
1356 When the daemon runs with @code{--no-substitutes}, clients can still
1357 explicitly enable substitution @i{via} the @code{set-build-options}
1358 remote procedure call (@pxref{The Store}).
1360 @item --substitute-urls=@var{urls}
1361 @anchor{daemon-substitute-urls}
1362 Consider @var{urls} the default whitespace-separated list of substitute
1363 source URLs. When this option is omitted,
1364 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1366 This means that substitutes may be downloaded from @var{urls}, as long
1367 as they are signed by a trusted signature (@pxref{Substitutes}).
1370 @item --no-build-hook
1371 Do not use the @dfn{build hook}.
1373 The build hook is a helper program that the daemon can start and to
1374 which it submits build requests. This mechanism is used to offload
1375 builds to other machines (@pxref{Daemon Offload Setup}).
1377 @item --cache-failures
1378 Cache build failures. By default, only successful builds are cached.
1380 When this option is used, @command{guix gc --list-failures} can be used
1381 to query the set of store items marked as failed; @command{guix gc
1382 --clear-failures} removes store items from the set of cached failures.
1383 @xref{Invoking guix gc}.
1385 @item --cores=@var{n}
1387 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1390 The default value is @code{0}, but it may be overridden by clients, such
1391 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1394 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1395 in the build process, which can then use it to exploit internal
1396 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1398 @item --max-jobs=@var{n}
1400 Allow at most @var{n} build jobs in parallel. The default value is
1401 @code{1}. Setting it to @code{0} means that no builds will be performed
1402 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1403 Setup}), or simply fail.
1405 @item --max-silent-time=@var{seconds}
1406 When the build or substitution process remains silent for more than
1407 @var{seconds}, terminate it and report a build failure.
1409 The default value is @code{0}, which disables the timeout.
1411 The value specified here can be overridden by clients (@pxref{Common
1412 Build Options, @code{--max-silent-time}}).
1414 @item --timeout=@var{seconds}
1415 Likewise, when the build or substitution process lasts for more than
1416 @var{seconds}, terminate it and report a build failure.
1418 The default value is @code{0}, which disables the timeout.
1420 The value specified here can be overridden by clients (@pxref{Common
1421 Build Options, @code{--timeout}}).
1423 @item --rounds=@var{N}
1424 Build each derivation @var{n} times in a row, and raise an error if
1425 consecutive build results are not bit-for-bit identical. Note that this
1426 setting can be overridden by clients such as @command{guix build}
1427 (@pxref{Invoking guix build}).
1429 When used in conjunction with @option{--keep-failed}, the differing
1430 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1431 This makes it easy to look for differences between the two results.
1434 Produce debugging output.
1436 This is useful to debug daemon start-up issues, but then it may be
1437 overridden by clients, for example the @code{--verbosity} option of
1438 @command{guix build} (@pxref{Invoking guix build}).
1440 @item --chroot-directory=@var{dir}
1441 Add @var{dir} to the build chroot.
1443 Doing this may change the result of build processes---for instance if
1444 they use optional dependencies found in @var{dir} when it is available,
1445 and not otherwise. For that reason, it is not recommended to do so.
1446 Instead, make sure that each derivation declares all the inputs that it
1449 @item --disable-chroot
1450 Disable chroot builds.
1452 Using this option is not recommended since, again, it would allow build
1453 processes to gain access to undeclared dependencies. It is necessary,
1454 though, when @command{guix-daemon} is running under an unprivileged user
1457 @item --log-compression=@var{type}
1458 Compress build logs according to @var{type}, one of @code{gzip},
1459 @code{bzip2}, or @code{none}.
1461 Unless @code{--lose-logs} is used, all the build logs are kept in the
1462 @var{localstatedir}. To save space, the daemon automatically compresses
1463 them with bzip2 by default.
1465 @item --disable-deduplication
1466 @cindex deduplication
1467 Disable automatic file ``deduplication'' in the store.
1469 By default, files added to the store are automatically ``deduplicated'':
1470 if a newly added file is identical to another one found in the store,
1471 the daemon makes the new file a hard link to the other file. This can
1472 noticeably reduce disk usage, at the expense of slightly increased
1473 input/output load at the end of a build process. This option disables
1476 @item --gc-keep-outputs[=yes|no]
1477 Tell whether the garbage collector (GC) must keep outputs of live
1481 @cindex garbage collector roots
1482 When set to ``yes'', the GC will keep the outputs of any live derivation
1483 available in the store---the @code{.drv} files. The default is ``no'',
1484 meaning that derivation outputs are kept only if they are reachable from a GC
1485 root. @xref{Invoking guix gc}, for more on GC roots.
1487 @item --gc-keep-derivations[=yes|no]
1488 Tell whether the garbage collector (GC) must keep derivations
1489 corresponding to live outputs.
1491 When set to ``yes'', as is the case by default, the GC keeps
1492 derivations---i.e., @code{.drv} files---as long as at least one of their
1493 outputs is live. This allows users to keep track of the origins of
1494 items in their store. Setting it to ``no'' saves a bit of disk space.
1496 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1497 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1498 ``yes'' causes liveness to flow from derivations to outputs. When both are
1499 set to ``yes'', the effect is to keep all the build prerequisites (the
1500 sources, compiler, libraries, and other build-time tools) of live objects in
1501 the store, regardless of whether these prerequisites are reachable from a GC
1502 root. This is convenient for developers since it saves rebuilds or downloads.
1504 @item --impersonate-linux-2.6
1505 On Linux-based systems, impersonate Linux 2.6. This means that the
1506 kernel's @code{uname} system call will report 2.6 as the release number.
1508 This might be helpful to build programs that (usually wrongfully) depend
1509 on the kernel version number.
1512 Do not keep build logs. By default they are kept under
1513 @code{@var{localstatedir}/guix/log}.
1515 @item --system=@var{system}
1516 Assume @var{system} as the current system type. By default it is the
1517 architecture/kernel pair found at configure time, such as
1518 @code{x86_64-linux}.
1520 @item --listen=@var{endpoint}
1521 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1522 as the file name of a Unix-domain socket if it starts with
1523 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1524 host name or host name and port to listen to. Here are a few examples:
1527 @item --listen=/gnu/var/daemon
1528 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1529 creating it if needed.
1531 @item --listen=localhost
1532 @cindex daemon, remote access
1533 @cindex remote access to the daemon
1534 @cindex daemon, cluster setup
1535 @cindex clusters, daemon setup
1536 Listen for TCP connections on the network interface corresponding to
1537 @code{localhost}, on port 44146.
1539 @item --listen=128.0.0.42:1234
1540 Listen for TCP connections on the network interface corresponding to
1541 @code{128.0.0.42}, on port 1234.
1544 This option can be repeated multiple times, in which case
1545 @command{guix-daemon} accepts connections on all the specified
1546 endpoints. Users can tell client commands what endpoint to connect to
1547 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1548 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1551 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1552 @code{--listen=@var{host}} is suitable on local networks, such as
1553 clusters, where only trusted nodes may connect to the build daemon. In
1554 other cases where remote access to the daemon is needed, we recommend
1555 using Unix-domain sockets along with SSH.
1558 When @code{--listen} is omitted, @command{guix-daemon} listens for
1559 connections on the Unix-domain socket located at
1560 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1564 @node Application Setup
1565 @section Application Setup
1567 @cindex foreign distro
1568 When using Guix on top of GNU/Linux distribution other than Guix System---a
1569 so-called @dfn{foreign distro}---a few additional steps are needed to
1570 get everything in place. Here are some of them.
1574 @anchor{locales-and-locpath}
1575 @cindex locales, when not on Guix System
1577 @vindex GUIX_LOCPATH
1578 Packages installed @i{via} Guix will not use the locale data of the
1579 host system. Instead, you must first install one of the locale packages
1580 available with Guix and then define the @code{GUIX_LOCPATH} environment
1584 $ guix install glibc-locales
1585 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1588 Note that the @code{glibc-locales} package contains data for all the
1589 locales supported by the GNU@tie{}libc and weighs in at around
1590 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1591 limited to a few UTF-8 locales.
1593 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1594 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1595 Manual}). There are two important differences though:
1599 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1600 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1601 to make sure the programs of the foreign distro will not end up loading
1602 incompatible locale data.
1605 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1606 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1607 should your Guix profile contain a mixture of programs linked against
1608 different libc version, each libc version will only try to load locale
1609 data in the right format.
1612 This is important because the locale data format used by different libc
1613 versions may be incompatible.
1615 @subsection Name Service Switch
1617 @cindex name service switch, glibc
1618 @cindex NSS (name service switch), glibc
1619 @cindex nscd (name service caching daemon)
1620 @cindex name service caching daemon (nscd)
1621 When using Guix on a foreign distro, we @emph{strongly recommend} that
1622 the system run the GNU C library's @dfn{name service cache daemon},
1623 @command{nscd}, which should be listening on the
1624 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1625 installed with Guix may fail to look up host names or user accounts, or
1626 may even crash. The next paragraphs explain why.
1628 @cindex @file{nsswitch.conf}
1629 The GNU C library implements a @dfn{name service switch} (NSS), which is
1630 an extensible mechanism for ``name lookups'' in general: host name
1631 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1632 The GNU C Library Reference Manual}).
1634 @cindex Network information service (NIS)
1635 @cindex NIS (Network information service)
1636 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1637 lookup implementations: for example, the @code{nss-mdns} plugin allow
1638 resolution of @code{.local} host names, the @code{nis} plugin allows
1639 user account lookup using the Network information service (NIS), and so
1640 on. These extra ``lookup services'' are configured system-wide in
1641 @file{/etc/nsswitch.conf}, and all the programs running on the system
1642 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1645 When they perform a name lookup---for instance by calling the
1646 @code{getaddrinfo} function in C---applications first try to connect to
1647 the nscd; on success, nscd performs name lookups on their behalf. If
1648 the nscd is not running, then they perform the name lookup by
1649 themselves, by loading the name lookup services into their own address
1650 space and running it. These name lookup services---the
1651 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1652 the host system's C library, rather than from the C library the
1653 application is linked against (the C library coming from Guix).
1655 And this is where the problem is: if your application is linked against
1656 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1657 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1658 likely crash or have its name lookups fail unexpectedly.
1660 Running @command{nscd} on the system, among other advantages, eliminates
1661 this binary incompatibility problem because those @code{libnss_*.so}
1662 files are loaded in the @command{nscd} process, not in applications
1665 @subsection X11 Fonts
1668 The majority of graphical applications use Fontconfig to locate and
1669 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1670 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1671 by default. Thus, to allow graphical applications installed with Guix
1672 to display fonts, you have to install fonts with Guix as well.
1673 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1674 @code{font-gnu-freefont-ttf}.
1676 To display text written in Chinese languages, Japanese, or Korean in
1677 graphical applications, consider installing
1678 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1679 has multiple outputs, one per language family (@pxref{Packages with
1680 Multiple Outputs}). For instance, the following command installs fonts
1681 for Chinese languages:
1684 guix install font-adobe-source-han-sans:cn
1687 @cindex @code{xterm}
1688 Older programs such as @command{xterm} do not use Fontconfig and instead
1689 rely on server-side font rendering. Such programs require to specify a
1690 full name of a font using XLFD (X Logical Font Description), like this:
1693 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1696 To be able to use such full names for the TrueType fonts installed in
1697 your Guix profile, you need to extend the font path of the X server:
1699 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1700 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1702 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1705 @cindex @code{xlsfonts}
1706 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1707 to make sure your TrueType fonts are listed there.
1709 @cindex @code{fc-cache}
1711 After installing fonts you may have to refresh the font cache to use
1712 them in applications. The same applies when applications installed via
1713 Guix do not seem to find fonts. To force rebuilding of the font cache
1714 run @code{fc-cache -f}. The @code{fc-cache} command is provided by the
1715 @code{fontconfig} package.
1717 @subsection X.509 Certificates
1719 @cindex @code{nss-certs}
1720 The @code{nss-certs} package provides X.509 certificates, which allow
1721 programs to authenticate Web servers accessed over HTTPS.
1723 When using Guix on a foreign distro, you can install this package and
1724 define the relevant environment variables so that packages know where to
1725 look for certificates. @xref{X.509 Certificates}, for detailed
1728 @subsection Emacs Packages
1730 @cindex @code{emacs}
1731 When you install Emacs packages with Guix, the elisp files may be placed
1732 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1734 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1735 directory exists because potentially there may exist thousands of Emacs
1736 packages and storing all their files in a single directory may not be
1737 reliable (because of name conflicts). So we think using a separate
1738 directory for each package is a good idea. It is very similar to how
1739 the Emacs package system organizes the file structure (@pxref{Package
1740 Files,,, emacs, The GNU Emacs Manual}).
1742 By default, Emacs (installed with Guix) ``knows'' where these packages
1743 are placed, so you do not need to perform any configuration. If, for
1744 some reason, you want to avoid auto-loading Emacs packages installed
1745 with Guix, you can do so by running Emacs with @code{--no-site-file}
1746 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1748 @subsection The GCC toolchain
1753 Guix offers individual compiler packages such as @code{gcc} but if you
1754 are in need of a complete toolchain for compiling and linking source
1755 code what you really want is the @code{gcc-toolchain} package. This
1756 package provides a complete GCC toolchain for C/C++ development,
1757 including GCC itself, the GNU C Library (headers and binaries, plus
1758 debugging symbols in the @code{debug} output), Binutils, and a linker
1761 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1762 passed to the linker, add corresponding @code{-rpath} arguments, and
1763 invoke the actual linker with this new set of arguments. You can instruct the
1764 wrapper to refuse to link against libraries not in the store by setting the
1765 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
1769 @c *********************************************************************
1770 @node System Installation
1771 @chapter System Installation
1773 @cindex installing Guix System
1774 @cindex Guix System, installation
1775 This section explains how to install Guix System
1776 on a machine. Guix, as a package manager, can
1777 also be installed on top of a running GNU/Linux system,
1778 @pxref{Installation}.
1782 @c This paragraph is for people reading this from tty2 of the
1783 @c installation image.
1784 You are reading this documentation with an Info reader. For details on
1785 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1786 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1787 Info}. Hit @kbd{l} afterwards to come back here.
1789 Alternately, run @command{info info} in another tty to keep the manual
1795 * Limitations:: What you can expect.
1796 * Hardware Considerations:: Supported hardware.
1797 * USB Stick and DVD Installation:: Preparing the installation medium.
1798 * Preparing for Installation:: Networking, partitioning, etc.
1799 * Guided Graphical Installation:: Easy graphical installation.
1800 * Manual Installation:: Manual installation for wizards.
1801 * After System Installation:: When installation succeeded.
1802 * Installing Guix in a VM:: Guix System playground.
1803 * Building the Installation Image:: How this comes to be.
1807 @section Limitations
1809 We consider Guix System to be ready for a wide range of ``desktop'' and server
1810 use cases. The reliability guarantees it provides---transactional upgrades
1811 and rollbacks, reproducibility---make it a solid foundation.
1813 Nevertheless, before you proceed with the installation, be aware of the
1814 following noteworthy limitations applicable to version @value{VERSION}:
1818 Support for the Logical Volume Manager (LVM) is missing.
1821 More and more system services are provided (@pxref{Services}), but some
1825 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1826 as well as a number of X11 window managers. However, KDE is currently
1830 More than a disclaimer, this is an invitation to report issues (and success
1831 stories!), and to join us in improving it. @xref{Contributing}, for more
1835 @node Hardware Considerations
1836 @section Hardware Considerations
1838 @cindex hardware support on Guix System
1839 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1840 builds around the kernel Linux-libre, which means that only hardware for
1841 which free software drivers and firmware exist is supported. Nowadays,
1842 a wide range of off-the-shelf hardware is supported on
1843 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1844 Ethernet controllers. Unfortunately, there are still areas where
1845 hardware vendors deny users control over their own computing, and such
1846 hardware is not supported on Guix System.
1848 @cindex WiFi, hardware support
1849 One of the main areas where free drivers or firmware are lacking is WiFi
1850 devices. WiFi devices known to work include those using Atheros chips
1851 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1852 driver, and those using Broadcom/AirForce chips (BCM43xx with
1853 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1854 Linux-libre driver. Free firmware exists for both and is available
1855 out-of-the-box on Guix System, as part of @code{%base-firmware}
1856 (@pxref{operating-system Reference, @code{firmware}}).
1858 @cindex RYF, Respects Your Freedom
1859 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1860 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1861 certification program for hardware products that respect your freedom
1862 and your privacy and ensure that you have control over your device. We
1863 encourage you to check the list of RYF-certified devices.
1865 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1866 web site. It contains a catalog of hardware devices with information
1867 about their support in GNU/Linux.
1870 @node USB Stick and DVD Installation
1871 @section USB Stick and DVD Installation
1873 An ISO-9660 installation image that can be written to a USB stick or
1874 burnt to a DVD can be downloaded from
1875 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1876 where @var{system} is one of:
1880 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1883 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1886 @c start duplication of authentication part from ``Binary Installation''
1887 Make sure to download the associated @file{.sig} file and to verify the
1888 authenticity of the image against it, along these lines:
1891 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1892 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1895 If that command fails because you do not have the required public key,
1896 then run this command to import it:
1899 $ gpg --keyserver @value{KEY-SERVER} \
1900 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
1904 and rerun the @code{gpg --verify} command.
1907 This image contains the tools necessary for an installation.
1908 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1910 @unnumberedsubsec Copying to a USB Stick
1912 To copy the image to a USB stick, follow these steps:
1916 Decompress the image using the @command{xz} command:
1919 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1923 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1924 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1925 copy the image with:
1928 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1932 Access to @file{/dev/sdX} usually requires root privileges.
1935 @unnumberedsubsec Burning on a DVD
1937 To copy the image to a DVD, follow these steps:
1941 Decompress the image using the @command{xz} command:
1944 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1948 Insert a blank DVD into your machine, and determine
1949 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
1950 copy the image with:
1953 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
1956 Access to @file{/dev/srX} usually requires root privileges.
1959 @unnumberedsubsec Booting
1961 Once this is done, you should be able to reboot the system and boot from
1962 the USB stick or DVD. The latter usually requires you to get in the
1963 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
1965 @xref{Installing Guix in a VM}, if, instead, you would like to install
1966 Guix System in a virtual machine (VM).
1969 @node Preparing for Installation
1970 @section Preparing for Installation
1972 Once you have booted, you can use the guided graphical installer, which makes
1973 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
1974 if you are already familiar with GNU/Linux and if you want more control than
1975 what the graphical installer provides, you can choose the ``manual''
1976 installation process (@pxref{Manual Installation}).
1978 The graphical installer is available on TTY1. You can obtain root shells on
1979 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
1980 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
1981 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
1982 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
1983 which allows you to select text with the left mouse button and to paste it
1984 with the middle button.
1987 Installation requires access to the Internet so that any missing
1988 dependencies of your system configuration can be downloaded. See the
1989 ``Networking'' section below.
1992 @node Guided Graphical Installation
1993 @section Guided Graphical Installation
1995 The graphical installer is a text-based user interface. It will guide you,
1996 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
1998 The first dialog boxes allow you to set up the system as you use it during the
1999 installation: you can choose the language, keyboard layout, and set up
2000 networking, which will be used during the installation. The image below shows
2001 the networking dialog.
2003 @image{images/installer-network,5in,, networking setup with the graphical installer}
2005 Later steps allow you to partition your hard disk, as shown in the image
2006 below, to choose whether or not to use encrypted file systems, to enter the
2007 host name and root password, and to create an additional account, among other
2010 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2012 Note that, at any time, the installer allows you to exit the current
2013 installation step and resume at a previous step, as show in the image below.
2015 @image{images/installer-resume,5in,, resuming the installation process}
2017 Once you're done, the installer produces an operating system configuration and
2018 displays it (@pxref{Using the Configuration System}). At that point you can
2019 hit ``OK'' and installation will proceed. On success, you can reboot into the
2020 new system and enjoy. @xref{After System Installation}, for what's next!
2023 @node Manual Installation
2024 @section Manual Installation
2026 This section describes how you would ``manually'' install GNU@tie{}Guix System
2027 on your machine. This option requires familiarity with GNU/Linux, with the
2028 shell, and with common administration tools. If you think this is not for
2029 you, consider using the guided graphical installer (@pxref{Guided Graphical
2032 The installation system provides root shells on TTYs 3 to 6; press
2033 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2034 many common tools needed to install the system. But it is also a full-blown
2035 Guix System, which means that you can install additional packages, should you
2036 need it, using @command{guix package} (@pxref{Invoking guix package}).
2039 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2040 * Proceeding with the Installation:: Installing.
2043 @node Keyboard Layout and Networking and Partitioning
2044 @subsection Keyboard Layout, Networking, and Partitioning
2046 Before you can install the system, you may want to adjust the keyboard layout,
2047 set up networking, and partition your target hard disk. This section will
2048 guide you through this.
2050 @subsubsection Keyboard Layout
2052 @cindex keyboard layout
2053 The installation image uses the US qwerty keyboard layout. If you want
2054 to change it, you can use the @command{loadkeys} command. For example,
2055 the following command selects the Dvorak keyboard layout:
2061 See the files under @file{/run/current-system/profile/share/keymaps} for
2062 a list of available keyboard layouts. Run @command{man loadkeys} for
2065 @subsubsection Networking
2067 Run the following command to see what your network interfaces are called:
2074 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2080 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2081 Wired interfaces have a name starting with @samp{e}; for example, the
2082 interface corresponding to the first on-board Ethernet controller is
2083 called @samp{eno1}. Wireless interfaces have a name starting with
2084 @samp{w}, like @samp{w1p2s0}.
2087 @item Wired connection
2088 To configure a wired network run the following command, substituting
2089 @var{interface} with the name of the wired interface you want to use.
2092 ifconfig @var{interface} up
2095 @item Wireless connection
2098 To configure wireless networking, you can create a configuration file
2099 for the @command{wpa_supplicant} configuration tool (its location is not
2100 important) using one of the available text editors such as
2104 nano wpa_supplicant.conf
2107 As an example, the following stanza can go to this file and will work
2108 for many wireless networks, provided you give the actual SSID and
2109 passphrase for the network you are connecting to:
2113 ssid="@var{my-ssid}"
2115 psk="the network's secret passphrase"
2119 Start the wireless service and run it in the background with the
2120 following command (substitute @var{interface} with the name of the
2121 network interface you want to use):
2124 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2127 Run @command{man wpa_supplicant} for more information.
2131 At this point, you need to acquire an IP address. On a network where IP
2132 addresses are automatically assigned @i{via} DHCP, you can run:
2135 dhclient -v @var{interface}
2138 Try to ping a server to see if networking is up and running:
2144 Setting up network access is almost always a requirement because the
2145 image does not contain all the software and tools that may be needed.
2147 @cindex installing over SSH
2148 If you want to, you can continue the installation remotely by starting
2152 herd start ssh-daemon
2155 Make sure to either set a password with @command{passwd}, or configure
2156 OpenSSH public key authentication before logging in.
2158 @subsubsection Disk Partitioning
2160 Unless this has already been done, the next step is to partition, and
2161 then format the target partition(s).
2163 The installation image includes several partitioning tools, including
2164 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2165 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2166 the partition layout you want:
2172 If your disk uses the GUID Partition Table (GPT) format and you plan to
2173 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2174 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2177 @cindex EFI, installation
2178 @cindex UEFI, installation
2179 @cindex ESP, EFI system partition
2180 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2181 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2182 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2185 parted /dev/sda set 1 esp on
2189 @vindex grub-bootloader
2190 @vindex grub-efi-bootloader
2191 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2192 @file{/sys/firmware/efi} exists in the installation image, then you should
2193 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2194 Otherwise you should use the BIOS-based GRUB, known as
2195 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2199 Once you are done partitioning the target hard disk drive, you have to
2200 create a file system on the relevant partition(s)@footnote{Currently
2201 Guix System only supports ext4 and btrfs file systems. In particular, code
2202 that reads file system UUIDs and labels only works for these file system
2203 types.}. For the ESP, if you have one and assuming it is
2204 @file{/dev/sda1}, run:
2207 mkfs.fat -F32 /dev/sda1
2210 Preferably, assign file systems a label so that you can easily and
2211 reliably refer to them in @code{file-system} declarations (@pxref{File
2212 Systems}). This is typically done using the @code{-L} option of
2213 @command{mkfs.ext4} and related commands. So, assuming the target root
2214 partition lives at @file{/dev/sda2}, a file system with the label
2215 @code{my-root} can be created with:
2218 mkfs.ext4 -L my-root /dev/sda2
2221 @cindex encrypted disk
2222 If you are instead planning to encrypt the root partition, you can use
2223 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2224 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2225 @code{man cryptsetup}} for more information.) Assuming you want to
2226 store the root partition on @file{/dev/sda2}, the command sequence would
2227 be along these lines:
2230 cryptsetup luksFormat /dev/sda2
2231 cryptsetup open --type luks /dev/sda2 my-partition
2232 mkfs.ext4 -L my-root /dev/mapper/my-partition
2235 Once that is done, mount the target file system under @file{/mnt}
2236 with a command like (again, assuming @code{my-root} is the label of the
2240 mount LABEL=my-root /mnt
2243 Also mount any other file systems you would like to use on the target
2244 system relative to this path. If you have opted for @file{/boot/efi} as an
2245 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2246 found by @code{guix system init} afterwards.
2248 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2249 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2250 sure to initialize them with @command{mkswap}. Assuming you have one
2251 swap partition on @file{/dev/sda3}, you would run:
2258 Alternatively, you may use a swap file. For example, assuming that in
2259 the new system you want to use the file @file{/swapfile} as a swap file,
2260 you would run@footnote{This example will work for many types of file
2261 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2262 btrfs), the required steps may be different. For details, see the
2263 manual pages for @command{mkswap} and @command{swapon}.}:
2266 # This is 10 GiB of swap space. Adjust "count" to change the size.
2267 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2268 # For security, make the file readable and writable only by root.
2269 chmod 600 /mnt/swapfile
2270 mkswap /mnt/swapfile
2271 swapon /mnt/swapfile
2274 Note that if you have encrypted the root partition and created a swap
2275 file in its file system as described above, then the encryption also
2276 protects the swap file, just like any other file in that file system.
2278 @node Proceeding with the Installation
2279 @subsection Proceeding with the Installation
2281 With the target partitions ready and the target root mounted on
2282 @file{/mnt}, we're ready to go. First, run:
2285 herd start cow-store /mnt
2288 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2289 during the installation phase are written to the target disk on @file{/mnt}
2290 rather than kept in memory. This is necessary because the first phase of
2291 the @command{guix system init} command (see below) entails downloads or
2292 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2294 Next, you have to edit a file and
2295 provide the declaration of the operating system to be installed. To
2296 that end, the installation system comes with three text editors. We
2297 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2298 supports syntax highlighting and parentheses matching; other editors
2299 include GNU Zile (an Emacs clone), and
2300 nvi (a clone of the original BSD @command{vi} editor).
2301 We strongly recommend storing that file on the target root file system, say,
2302 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2303 configuration file once you have rebooted into the newly-installed system.
2305 @xref{Using the Configuration System}, for an overview of the
2306 configuration file. The example configurations discussed in that
2307 section are available under @file{/etc/configuration} in the
2308 installation image. Thus, to get started with a system configuration
2309 providing a graphical display server (a ``desktop'' system), you can run
2310 something along these lines:
2314 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2315 # nano /mnt/etc/config.scm
2318 You should pay attention to what your configuration file contains, and
2323 Make sure the @code{bootloader-configuration} form refers to the target
2324 you want to install GRUB on. It should mention @code{grub-bootloader} if
2325 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2326 for newer UEFI systems. For legacy systems, the @code{target} field
2327 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2328 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2329 currently mounted and a @code{file-system} entry is specified in your
2333 Be sure that your file system labels match the value of their respective
2334 @code{device} fields in your @code{file-system} configuration, assuming
2335 your @code{file-system} configuration uses the @code{file-system-label}
2336 procedure in its @code{device} field.
2339 If there are encrypted or RAID partitions, make sure to add a
2340 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2343 Once you are done preparing the configuration file, the new system must
2344 be initialized (remember that the target root file system is mounted
2348 guix system init /mnt/etc/config.scm /mnt
2352 This copies all the necessary files and installs GRUB on
2353 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2354 more information, @pxref{Invoking guix system}. This command may trigger
2355 downloads or builds of missing packages, which can take some time.
2357 Once that command has completed---and hopefully succeeded!---you can run
2358 @command{reboot} and boot into the new system. The @code{root} password
2359 in the new system is initially empty; other users' passwords need to be
2360 initialized by running the @command{passwd} command as @code{root},
2361 unless your configuration specifies otherwise
2362 (@pxref{user-account-password, user account passwords}).
2363 @xref{After System Installation}, for what's next!
2366 @node After System Installation
2367 @section After System Installation
2369 Success, you've now booted into Guix System! From then on, you can update the
2370 system whenever you want by running, say:
2374 sudo guix system reconfigure /etc/config.scm
2378 This builds a new system generation with the latest packages and services
2379 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2380 your system includes the latest security updates (@pxref{Security Updates}).
2382 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2384 @cindex sudo vs. @command{guix pull}
2385 Note that @command{sudo guix} runs your user's @command{guix} command and
2386 @emph{not} root's, because @command{sudo} leaves @code{PATH} unchanged. To
2387 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2390 Join us on @code{#guix} on the Freenode IRC network or on
2391 @email{guix-devel@@gnu.org} to share your experience!
2394 @node Installing Guix in a VM
2395 @section Installing Guix in a Virtual Machine
2397 @cindex virtual machine, Guix System installation
2398 @cindex virtual private server (VPS)
2399 @cindex VPS (virtual private server)
2400 If you'd like to install Guix System in a virtual machine (VM) or on a
2401 virtual private server (VPS) rather than on your beloved machine, this
2404 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2405 disk image, follow these steps:
2409 First, retrieve and decompress the Guix system installation image as
2410 described previously (@pxref{USB Stick and DVD Installation}).
2413 Create a disk image that will hold the installed system. To make a
2414 qcow2-formatted disk image, use the @command{qemu-img} command:
2417 qemu-img create -f qcow2 guixsd.img 50G
2420 The resulting file will be much smaller than 50 GB (typically less than
2421 1 MB), but it will grow as the virtualized storage device is filled up.
2424 Boot the USB installation image in an VM:
2427 qemu-system-x86_64 -m 1024 -smp 1 \
2428 -net user -net nic,model=virtio -boot menu=on \
2429 -drive file=guix-system-install-@value{VERSION}.@var{system}.iso \
2430 -drive file=guixsd.img
2433 The ordering of the drives matters.
2435 In the VM console, quickly press the @kbd{F12} key to enter the boot
2436 menu. Then press the @kbd{2} key and the @kbd{RET} key to validate your
2440 You're now root in the VM, proceed with the installation process.
2441 @xref{Preparing for Installation}, and follow the instructions.
2444 Once installation is complete, you can boot the system that's on your
2445 @file{guixsd.img} image. @xref{Running Guix in a VM}, for how to do
2448 @node Building the Installation Image
2449 @section Building the Installation Image
2451 @cindex installation image
2452 The installation image described above was built using the @command{guix
2453 system} command, specifically:
2456 guix system disk-image --file-system-type=iso9660 \
2457 gnu/system/install.scm
2460 Have a look at @file{gnu/system/install.scm} in the source tree,
2461 and see also @ref{Invoking guix system} for more information
2462 about the installation image.
2464 @section Building the Installation Image for ARM Boards
2466 Many ARM boards require a specific variant of the
2467 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2469 If you build a disk image and the bootloader is not available otherwise
2470 (on another boot drive etc), it's advisable to build an image that
2471 includes the bootloader, specifically:
2474 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2477 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2478 board, a list of possible boards will be printed.
2480 @c *********************************************************************
2481 @node Package Management
2482 @chapter Package Management
2485 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2486 remove software packages, without having to know about their build
2487 procedures or dependencies. Guix also goes beyond this obvious set of
2490 This chapter describes the main features of Guix, as well as the
2491 package management tools it provides. Along with the command-line
2492 interface described below (@pxref{Invoking guix package, @code{guix
2493 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2494 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2495 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2499 guix install emacs-guix
2503 * Features:: How Guix will make your life brighter.
2504 * Invoking guix package:: Package installation, removal, etc.
2505 * Substitutes:: Downloading pre-built binaries.
2506 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2507 * Invoking guix gc:: Running the garbage collector.
2508 * Invoking guix pull:: Fetching the latest Guix and distribution.
2509 * Channels:: Customizing the package collection.
2510 * Inferiors:: Interacting with another revision of Guix.
2511 * Invoking guix describe:: Display information about your Guix revision.
2512 * Invoking guix archive:: Exporting and importing store files.
2518 When using Guix, each package ends up in the @dfn{package store}, in its
2519 own directory---something that resembles
2520 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2522 Instead of referring to these directories, users have their own
2523 @dfn{profile}, which points to the packages that they actually want to
2524 use. These profiles are stored within each user's home directory, at
2525 @code{$HOME/.guix-profile}.
2527 For example, @code{alice} installs GCC 4.7.2. As a result,
2528 @file{/home/alice/.guix-profile/bin/gcc} points to
2529 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2530 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2531 simply continues to point to
2532 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2533 coexist on the same system without any interference.
2535 The @command{guix package} command is the central tool to manage
2536 packages (@pxref{Invoking guix package}). It operates on the per-user
2537 profiles, and can be used @emph{with normal user privileges}.
2539 @cindex transactions
2540 The command provides the obvious install, remove, and upgrade
2541 operations. Each invocation is actually a @emph{transaction}: either
2542 the specified operation succeeds, or nothing happens. Thus, if the
2543 @command{guix package} process is terminated during the transaction,
2544 or if a power outage occurs during the transaction, then the user's
2545 profile remains in its previous state, and remains usable.
2547 In addition, any package transaction may be @emph{rolled back}. So, if,
2548 for example, an upgrade installs a new version of a package that turns
2549 out to have a serious bug, users may roll back to the previous instance
2550 of their profile, which was known to work well. Similarly, the global
2551 system configuration on Guix is subject to
2552 transactional upgrades and roll-back
2553 (@pxref{Using the Configuration System}).
2555 All packages in the package store may be @emph{garbage-collected}.
2556 Guix can determine which packages are still referenced by user
2557 profiles, and remove those that are provably no longer referenced
2558 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2559 generations of their profile so that the packages they refer to can be
2562 @cindex reproducibility
2563 @cindex reproducible builds
2564 Guix takes a @dfn{purely functional} approach to package
2565 management, as described in the introduction (@pxref{Introduction}).
2566 Each @file{/gnu/store} package directory name contains a hash of all the
2567 inputs that were used to build that package---compiler, libraries, build
2568 scripts, etc. This direct correspondence allows users to make sure a
2569 given package installation matches the current state of their
2570 distribution. It also helps maximize @dfn{build reproducibility}:
2571 thanks to the isolated build environments that are used, a given build
2572 is likely to yield bit-identical files when performed on different
2573 machines (@pxref{Invoking guix-daemon, container}).
2576 This foundation allows Guix to support @dfn{transparent binary/source
2577 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2578 available from an external source---a @dfn{substitute}, Guix just
2579 downloads it and unpacks it;
2580 otherwise, it builds the package from source, locally
2581 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2582 reproducible, users do not have to trust servers that provide
2583 substitutes: they can force a local build and @emph{challenge} providers
2584 (@pxref{Invoking guix challenge}).
2586 Control over the build environment is a feature that is also useful for
2587 developers. The @command{guix environment} command allows developers of
2588 a package to quickly set up the right development environment for their
2589 package, without having to manually install the dependencies of the
2590 package into their profile (@pxref{Invoking guix environment}).
2592 @cindex replication, of software environments
2593 @cindex provenance tracking, of software artifacts
2594 All of Guix and its package definitions is version-controlled, and
2595 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2596 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2597 Guix instance on a different machine or at a later point in time, which in
2598 turn allows you to @emph{replicate complete software environments}, while
2599 retaining precise @dfn{provenance tracking} of the software.
2601 @node Invoking guix package
2602 @section Invoking @command{guix package}
2604 @cindex installing packages
2605 @cindex removing packages
2606 @cindex package installation
2607 @cindex package removal
2608 The @command{guix package} command is the tool that allows users to
2609 install, upgrade, and remove packages, as well as rolling back to
2610 previous configurations. It operates only on the user's own profile,
2611 and works with normal user privileges (@pxref{Features}). Its syntax
2615 guix package @var{options}
2618 @cindex transactions
2619 Primarily, @var{options} specifies the operations to be performed during
2620 the transaction. Upon completion, a new profile is created, but
2621 previous @dfn{generations} of the profile remain available, should the user
2624 For example, to remove @code{lua} and install @code{guile} and
2625 @code{guile-cairo} in a single transaction:
2628 guix package -r lua -i guile guile-cairo
2631 @cindex aliases, for @command{guix package}
2632 For your convenience, we also provide the following aliases:
2636 @command{guix search} is an alias for @command{guix package -s},
2638 @command{guix install} is an alias for @command{guix package -i},
2640 @command{guix remove} is an alias for @command{guix package -r},
2642 and @command{guix upgrade} is an alias for @command{guix package -u}.
2645 These aliases are less expressive than @command{guix package} and provide
2646 fewer options, so in some cases you'll probably want to use @command{guix
2649 @command{guix package} also supports a @dfn{declarative approach}
2650 whereby the user specifies the exact set of packages to be available and
2651 passes it @i{via} the @option{--manifest} option
2652 (@pxref{profile-manifest, @option{--manifest}}).
2655 For each user, a symlink to the user's default profile is automatically
2656 created in @file{$HOME/.guix-profile}. This symlink always points to the
2657 current generation of the user's default profile. Thus, users can add
2658 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
2659 variable, and so on.
2660 @cindex search paths
2661 If you are not using Guix System, consider adding the
2662 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2663 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2664 shells get all the right environment variable definitions:
2667 GUIX_PROFILE="$HOME/.guix-profile" ; \
2668 source "$HOME/.guix-profile/etc/profile"
2671 In a multi-user setup, user profiles are stored in a place registered as
2672 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2673 to (@pxref{Invoking guix gc}). That directory is normally
2674 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2675 @var{localstatedir} is the value passed to @code{configure} as
2676 @code{--localstatedir}, and @var{user} is the user name. The
2677 @file{per-user} directory is created when @command{guix-daemon} is
2678 started, and the @var{user} sub-directory is created by @command{guix
2681 The @var{options} can be among the following:
2685 @item --install=@var{package} @dots{}
2686 @itemx -i @var{package} @dots{}
2687 Install the specified @var{package}s.
2689 Each @var{package} may specify either a simple package name, such as
2690 @code{guile}, or a package name followed by an at-sign and version number,
2691 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2692 case, the newest version prefixed by @code{1.8} is selected.)
2694 If no version number is specified, the
2695 newest available version will be selected. In addition, @var{package}
2696 may contain a colon, followed by the name of one of the outputs of the
2697 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2698 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2699 name (and optionally version) are searched for among the GNU
2700 distribution modules (@pxref{Package Modules}).
2702 @cindex propagated inputs
2703 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2704 that automatically get installed along with the required package
2705 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2706 @code{package} objects}, for information about propagated inputs in
2707 package definitions).
2709 @anchor{package-cmd-propagated-inputs}
2710 An example is the GNU MPC library: its C header files refer to those of
2711 the GNU MPFR library, which in turn refer to those of the GMP library.
2712 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2713 in the profile; removing MPC also removes MPFR and GMP---unless they had
2714 also been explicitly installed by the user.
2716 Besides, packages sometimes rely on the definition of environment
2717 variables for their search paths (see explanation of
2718 @code{--search-paths} below). Any missing or possibly incorrect
2719 environment variable definitions are reported here.
2721 @item --install-from-expression=@var{exp}
2723 Install the package @var{exp} evaluates to.
2725 @var{exp} must be a Scheme expression that evaluates to a
2726 @code{<package>} object. This option is notably useful to disambiguate
2727 between same-named variants of a package, with expressions such as
2728 @code{(@@ (gnu packages base) guile-final)}.
2730 Note that this option installs the first output of the specified
2731 package, which may be insufficient when needing a specific output of a
2732 multiple-output package.
2734 @item --install-from-file=@var{file}
2735 @itemx -f @var{file}
2736 Install the package that the code within @var{file} evaluates to.
2738 As an example, @var{file} might contain a definition like this
2739 (@pxref{Defining Packages}):
2742 @verbatiminclude package-hello.scm
2745 Developers may find it useful to include such a @file{guix.scm} file
2746 in the root of their project source tree that can be used to test
2747 development snapshots and create reproducible development environments
2748 (@pxref{Invoking guix environment}).
2750 @item --remove=@var{package} @dots{}
2751 @itemx -r @var{package} @dots{}
2752 Remove the specified @var{package}s.
2754 As for @code{--install}, each @var{package} may specify a version number
2755 and/or output name in addition to the package name. For instance,
2756 @code{-r glibc:debug} would remove the @code{debug} output of
2759 @item --upgrade[=@var{regexp} @dots{}]
2760 @itemx -u [@var{regexp} @dots{}]
2761 @cindex upgrading packages
2762 Upgrade all the installed packages. If one or more @var{regexp}s are
2763 specified, upgrade only installed packages whose name matches a
2764 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2766 Note that this upgrades package to the latest version of packages found
2767 in the distribution currently installed. To update your distribution,
2768 you should regularly run @command{guix pull} (@pxref{Invoking guix
2771 @item --do-not-upgrade[=@var{regexp} @dots{}]
2772 When used together with the @code{--upgrade} option, do @emph{not}
2773 upgrade any packages whose name matches a @var{regexp}. For example, to
2774 upgrade all packages in the current profile except those containing the
2775 substring ``emacs'':
2778 $ guix package --upgrade . --do-not-upgrade emacs
2781 @item @anchor{profile-manifest}--manifest=@var{file}
2782 @itemx -m @var{file}
2783 @cindex profile declaration
2784 @cindex profile manifest
2785 Create a new generation of the profile from the manifest object
2786 returned by the Scheme code in @var{file}.
2788 This allows you to @emph{declare} the profile's contents rather than
2789 constructing it through a sequence of @code{--install} and similar
2790 commands. The advantage is that @var{file} can be put under version
2791 control, copied to different machines to reproduce the same profile, and
2794 @c FIXME: Add reference to (guix profile) documentation when available.
2795 @var{file} must return a @dfn{manifest} object, which is roughly a list
2798 @findex packages->manifest
2800 (use-package-modules guile emacs)
2805 ;; Use a specific package output.
2806 (list guile-2.0 "debug")))
2809 @findex specifications->manifest
2810 In this example we have to know which modules define the @code{emacs}
2811 and @code{guile-2.0} variables to provide the right
2812 @code{use-package-modules} line, which can be cumbersome. We can
2813 instead provide regular package specifications and let
2814 @code{specifications->manifest} look up the corresponding package
2818 (specifications->manifest
2819 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2823 @cindex rolling back
2824 @cindex undoing transactions
2825 @cindex transactions, undoing
2826 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2827 the last transaction.
2829 When combined with options such as @code{--install}, roll back occurs
2830 before any other actions.
2832 When rolling back from the first generation that actually contains
2833 installed packages, the profile is made to point to the @dfn{zeroth
2834 generation}, which contains no files apart from its own metadata.
2836 After having rolled back, installing, removing, or upgrading packages
2837 overwrites previous future generations. Thus, the history of the
2838 generations in a profile is always linear.
2840 @item --switch-generation=@var{pattern}
2841 @itemx -S @var{pattern}
2843 Switch to a particular generation defined by @var{pattern}.
2845 @var{pattern} may be either a generation number or a number prefixed
2846 with ``+'' or ``-''. The latter means: move forward/backward by a
2847 specified number of generations. For example, if you want to return to
2848 the latest generation after @code{--roll-back}, use
2849 @code{--switch-generation=+1}.
2851 The difference between @code{--roll-back} and
2852 @code{--switch-generation=-1} is that @code{--switch-generation} will
2853 not make a zeroth generation, so if a specified generation does not
2854 exist, the current generation will not be changed.
2856 @item --search-paths[=@var{kind}]
2857 @cindex search paths
2858 Report environment variable definitions, in Bash syntax, that may be
2859 needed in order to use the set of installed packages. These environment
2860 variables are used to specify @dfn{search paths} for files used by some
2861 of the installed packages.
2863 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2864 environment variables to be defined so it can look for headers and
2865 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2866 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2867 library are installed in the profile, then @code{--search-paths} will
2868 suggest setting these variables to @code{@var{profile}/include} and
2869 @code{@var{profile}/lib}, respectively.
2871 The typical use case is to define these environment variables in the
2875 $ eval `guix package --search-paths`
2878 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2879 meaning that the returned environment variable definitions will either
2880 be exact settings, or prefixes or suffixes of the current value of these
2881 variables. When omitted, @var{kind} defaults to @code{exact}.
2883 This option can also be used to compute the @emph{combined} search paths
2884 of several profiles. Consider this example:
2887 $ guix package -p foo -i guile
2888 $ guix package -p bar -i guile-json
2889 $ guix package -p foo -p bar --search-paths
2892 The last command above reports about the @code{GUILE_LOAD_PATH}
2893 variable, even though, taken individually, neither @file{foo} nor
2894 @file{bar} would lead to that recommendation.
2897 @item --profile=@var{profile}
2898 @itemx -p @var{profile}
2899 Use @var{profile} instead of the user's default profile.
2901 @cindex collisions, in a profile
2902 @cindex colliding packages in profiles
2903 @cindex profile collisions
2904 @item --allow-collisions
2905 Allow colliding packages in the new profile. Use at your own risk!
2907 By default, @command{guix package} reports as an error @dfn{collisions}
2908 in the profile. Collisions happen when two or more different versions
2909 or variants of a given package end up in the profile.
2912 Use the bootstrap Guile to build the profile. This option is only
2913 useful to distribution developers.
2917 In addition to these actions, @command{guix package} supports the
2918 following options to query the current state of a profile, or the
2919 availability of packages:
2923 @item --search=@var{regexp}
2924 @itemx -s @var{regexp}
2925 @cindex searching for packages
2926 List the available packages whose name, synopsis, or description matches
2927 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
2928 Print all the metadata of matching packages in
2929 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
2930 GNU recutils manual}).
2932 This allows specific fields to be extracted using the @command{recsel}
2933 command, for instance:
2936 $ guix package -s malloc | recsel -p name,version,relevance
2950 Similarly, to show the name of all the packages available under the
2951 terms of the GNU@tie{}LGPL version 3:
2954 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
2961 It is also possible to refine search results using several @code{-s} flags to
2962 @command{guix package}, or several arguments to @command{guix search}. For
2963 example, the following command returns a list of board games (this time using
2964 the @command{guix search} alias):
2967 $ guix search '\<board\>' game | recsel -p name
2972 If we were to omit @code{-s game}, we would also get software packages
2973 that deal with printed circuit boards; removing the angle brackets
2974 around @code{board} would further add packages that have to do with
2977 And now for a more elaborate example. The following command searches
2978 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
2979 libraries, and prints the name and synopsis of the matching packages:
2982 $ guix search crypto library | \
2983 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
2987 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
2988 information on @dfn{selection expressions} for @code{recsel -e}.
2990 @item --show=@var{package}
2991 Show details about @var{package}, taken from the list of available packages, in
2992 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
2996 $ guix package --show=python | recsel -p name,version
3004 You may also specify the full name of a package to only get details about a
3005 specific version of it:
3007 $ guix package --show=python@@3.4 | recsel -p name,version
3014 @item --list-installed[=@var{regexp}]
3015 @itemx -I [@var{regexp}]
3016 List the currently installed packages in the specified profile, with the
3017 most recently installed packages shown last. When @var{regexp} is
3018 specified, list only installed packages whose name matches @var{regexp}.
3020 For each installed package, print the following items, separated by
3021 tabs: the package name, its version string, the part of the package that
3022 is installed (for instance, @code{out} for the default output,
3023 @code{include} for its headers, etc.), and the path of this package in
3026 @item --list-available[=@var{regexp}]
3027 @itemx -A [@var{regexp}]
3028 List packages currently available in the distribution for this system
3029 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3030 installed packages whose name matches @var{regexp}.
3032 For each package, print the following items separated by tabs: its name,
3033 its version string, the parts of the package (@pxref{Packages with
3034 Multiple Outputs}), and the source location of its definition.
3036 @item --list-generations[=@var{pattern}]
3037 @itemx -l [@var{pattern}]
3039 Return a list of generations along with their creation dates; for each
3040 generation, show the installed packages, with the most recently
3041 installed packages shown last. Note that the zeroth generation is never
3044 For each installed package, print the following items, separated by
3045 tabs: the name of a package, its version string, the part of the package
3046 that is installed (@pxref{Packages with Multiple Outputs}), and the
3047 location of this package in the store.
3049 When @var{pattern} is used, the command returns only matching
3050 generations. Valid patterns include:
3053 @item @emph{Integers and comma-separated integers}. Both patterns denote
3054 generation numbers. For instance, @code{--list-generations=1} returns
3057 And @code{--list-generations=1,8,2} outputs three generations in the
3058 specified order. Neither spaces nor trailing commas are allowed.
3060 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
3061 specified generations and everything in between. Note that the start of
3062 a range must be smaller than its end.
3064 It is also possible to omit the endpoint. For example,
3065 @code{--list-generations=2..}, returns all generations starting from the
3068 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3069 or months by passing an integer along with the first letter of the
3070 duration. For example, @code{--list-generations=20d} lists generations
3071 that are up to 20 days old.
3074 @item --delete-generations[=@var{pattern}]
3075 @itemx -d [@var{pattern}]
3076 When @var{pattern} is omitted, delete all generations except the current
3079 This command accepts the same patterns as @option{--list-generations}.
3080 When @var{pattern} is specified, delete the matching generations. When
3081 @var{pattern} specifies a duration, generations @emph{older} than the
3082 specified duration match. For instance, @code{--delete-generations=1m}
3083 deletes generations that are more than one month old.
3085 If the current generation matches, it is @emph{not} deleted. Also, the
3086 zeroth generation is never deleted.
3088 Note that deleting generations prevents rolling back to them.
3089 Consequently, this command must be used with care.
3093 Finally, since @command{guix package} may actually start build
3094 processes, it supports all the common build options (@pxref{Common Build
3095 Options}). It also supports package transformation options, such as
3096 @option{--with-source} (@pxref{Package Transformation Options}).
3097 However, note that package transformations are lost when upgrading; to
3098 preserve transformations across upgrades, you should define your own
3099 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
3100 (@pxref{Defining Packages}).
3103 @section Substitutes
3106 @cindex pre-built binaries
3107 Guix supports transparent source/binary deployment, which means that it
3108 can either build things locally, or download pre-built items from a
3109 server, or both. We call these pre-built items @dfn{substitutes}---they
3110 are substitutes for local build results. In many cases, downloading a
3111 substitute is much faster than building things locally.
3113 Substitutes can be anything resulting from a derivation build
3114 (@pxref{Derivations}). Of course, in the common case, they are
3115 pre-built package binaries, but source tarballs, for instance, which
3116 also result from derivation builds, can be available as substitutes.
3119 * Official Substitute Server:: One particular source of substitutes.
3120 * Substitute Server Authorization:: How to enable or disable substitutes.
3121 * Substitute Authentication:: How Guix verifies substitutes.
3122 * Proxy Settings:: How to get substitutes via proxy.
3123 * Substitution Failure:: What happens when substitution fails.
3124 * On Trusting Binaries:: How can you trust that binary blob?
3127 @node Official Substitute Server
3128 @subsection Official Substitute Server
3132 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3133 that builds packages from Guix continuously for some
3134 architectures, and makes them available as substitutes. This is the
3135 default source of substitutes; it can be overridden by passing the
3136 @option{--substitute-urls} option either to @command{guix-daemon}
3137 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3138 or to client tools such as @command{guix package}
3139 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3142 Substitute URLs can be either HTTP or HTTPS.
3143 HTTPS is recommended because communications are encrypted; conversely,
3144 using HTTP makes all communications visible to an eavesdropper, who
3145 could use the information gathered to determine, for instance, whether
3146 your system has unpatched security vulnerabilities.
3148 Substitutes from the official build farm are enabled by default when
3149 using Guix System (@pxref{GNU Distribution}). However,
3150 they are disabled by default when using Guix on a foreign distribution,
3151 unless you have explicitly enabled them via one of the recommended
3152 installation steps (@pxref{Installation}). The following paragraphs
3153 describe how to enable or disable substitutes for the official build
3154 farm; the same procedure can also be used to enable substitutes for any
3155 other substitute server.
3157 @node Substitute Server Authorization
3158 @subsection Substitute Server Authorization
3161 @cindex substitutes, authorization thereof
3162 @cindex access control list (ACL), for substitutes
3163 @cindex ACL (access control list), for substitutes
3164 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3166 must add its public key to the access control list (ACL) of archive
3167 imports, using the @command{guix archive} command (@pxref{Invoking guix
3168 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3169 be compromised and to serve genuine substitutes.
3171 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3172 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3173 the installation prefix of Guix. If you installed Guix from source,
3174 make sure you checked the GPG signature of
3175 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3176 Then, you can run something like this:
3179 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3183 Similarly, the @file{hydra.gnu.org.pub} file contains the public key
3184 of an independent build farm also run by the project, reachable at
3185 @indicateurl{https://mirror.hydra.gnu.org}.
3188 Once this is in place, the output of a command like @code{guix build}
3189 should change from something like:
3192 $ guix build emacs --dry-run
3193 The following derivations would be built:
3194 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3195 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3196 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3197 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3205 $ guix build emacs --dry-run
3206 112.3 MB would be downloaded:
3207 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3208 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3209 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3210 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3215 This indicates that substitutes from @code{@value{SUBSTITUTE-SERVER}} are usable and
3216 will be downloaded, when possible, for future builds.
3218 @cindex substitutes, how to disable
3219 The substitute mechanism can be disabled globally by running
3220 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
3221 guix-daemon}). It can also be disabled temporarily by passing the
3222 @code{--no-substitutes} option to @command{guix package}, @command{guix
3223 build}, and other command-line tools.
3225 @node Substitute Authentication
3226 @subsection Substitute Authentication
3228 @cindex digital signatures
3229 Guix detects and raises an error when attempting to use a substitute
3230 that has been tampered with. Likewise, it ignores substitutes that are
3231 not signed, or that are not signed by one of the keys listed in the ACL.
3233 There is one exception though: if an unauthorized server provides
3234 substitutes that are @emph{bit-for-bit identical} to those provided by
3235 an authorized server, then the unauthorized server becomes eligible for
3236 downloads. For example, assume we have chosen two substitute servers
3240 --substitute-urls="https://a.example.org https://b.example.org"
3244 @cindex reproducible builds
3245 If the ACL contains only the key for @code{b.example.org}, and if
3246 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
3247 then Guix will download substitutes from @code{a.example.org} because it
3248 comes first in the list and can be considered a mirror of
3249 @code{b.example.org}. In practice, independent build machines usually
3250 produce the same binaries, thanks to bit-reproducible builds (see
3253 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3254 (in other words, the server is not authenticated), contrary to what
3255 HTTPS clients such as Web browsers usually do. This is because Guix
3256 authenticates substitute information itself, as explained above, which
3257 is what we care about (whereas X.509 certificates are about
3258 authenticating bindings between domain names and public keys.)
3260 @node Proxy Settings
3261 @subsection Proxy Settings
3264 Substitutes are downloaded over HTTP or HTTPS.
3265 The @code{http_proxy} environment
3266 variable can be set in the environment of @command{guix-daemon} and is
3267 honored for downloads of substitutes. Note that the value of
3268 @code{http_proxy} in the environment where @command{guix build},
3269 @command{guix package}, and other client commands are run has
3270 @emph{absolutely no effect}.
3272 @node Substitution Failure
3273 @subsection Substitution Failure
3275 Even when a substitute for a derivation is available, sometimes the
3276 substitution attempt will fail. This can happen for a variety of
3277 reasons: the substitute server might be offline, the substitute may
3278 recently have been deleted, the connection might have been interrupted,
3281 When substitutes are enabled and a substitute for a derivation is
3282 available, but the substitution attempt fails, Guix will attempt to
3283 build the derivation locally depending on whether or not
3284 @code{--fallback} was given (@pxref{fallback-option,, common build
3285 option @code{--fallback}}). Specifically, if @code{--fallback} was
3286 omitted, then no local build will be performed, and the derivation is
3287 considered to have failed. However, if @code{--fallback} was given,
3288 then Guix will attempt to build the derivation locally, and the success
3289 or failure of the derivation depends on the success or failure of the
3290 local build. Note that when substitutes are disabled or no substitute
3291 is available for the derivation in question, a local build will
3292 @emph{always} be performed, regardless of whether or not
3293 @code{--fallback} was given.
3295 To get an idea of how many substitutes are available right now, you can
3296 try running the @command{guix weather} command (@pxref{Invoking guix
3297 weather}). This command provides statistics on the substitutes provided
3300 @node On Trusting Binaries
3301 @subsection On Trusting Binaries
3303 @cindex trust, of pre-built binaries
3304 Today, each individual's control over their own computing is at the
3305 mercy of institutions, corporations, and groups with enough power and
3306 determination to subvert the computing infrastructure and exploit its
3307 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3308 convenient, we encourage users to also build on their own, or even run
3309 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3310 interesting target. One way to help is by publishing the software you
3311 build using @command{guix publish} so that others have one more choice
3312 of server to download substitutes from (@pxref{Invoking guix publish}).
3314 Guix has the foundations to maximize build reproducibility
3315 (@pxref{Features}). In most cases, independent builds of a given
3316 package or derivation should yield bit-identical results. Thus, through
3317 a diverse set of independent package builds, we can strengthen the
3318 integrity of our systems. The @command{guix challenge} command aims to
3319 help users assess substitute servers, and to assist developers in
3320 finding out about non-deterministic package builds (@pxref{Invoking guix
3321 challenge}). Similarly, the @option{--check} option of @command{guix
3322 build} allows users to check whether previously-installed substitutes
3323 are genuine by rebuilding them locally (@pxref{build-check,
3324 @command{guix build --check}}).
3326 In the future, we want Guix to have support to publish and retrieve
3327 binaries to/from other users, in a peer-to-peer fashion. If you would
3328 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3330 @node Packages with Multiple Outputs
3331 @section Packages with Multiple Outputs
3333 @cindex multiple-output packages
3334 @cindex package outputs
3337 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3338 source package leads to exactly one directory in the store. When running
3339 @command{guix install glibc}, one installs the default output of the
3340 GNU libc package; the default output is called @code{out}, but its name
3341 can be omitted as shown in this command. In this particular case, the
3342 default output of @code{glibc} contains all the C header files, shared
3343 libraries, static libraries, Info documentation, and other supporting
3346 Sometimes it is more appropriate to separate the various types of files
3347 produced from a single source package into separate outputs. For
3348 instance, the GLib C library (used by GTK+ and related packages)
3349 installs more than 20 MiB of reference documentation as HTML pages.
3350 To save space for users who do not need it, the documentation goes to a
3351 separate output, called @code{doc}. To install the main GLib output,
3352 which contains everything but the documentation, one would run:
3358 @cindex documentation
3359 The command to install its documentation is:
3362 guix install glib:doc
3365 Some packages install programs with different ``dependency footprints''.
3366 For instance, the WordNet package installs both command-line tools and
3367 graphical user interfaces (GUIs). The former depend solely on the C
3368 library, whereas the latter depend on Tcl/Tk and the underlying X
3369 libraries. In this case, we leave the command-line tools in the default
3370 output, whereas the GUIs are in a separate output. This allows users
3371 who do not need the GUIs to save space. The @command{guix size} command
3372 can help find out about such situations (@pxref{Invoking guix size}).
3373 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3375 There are several such multiple-output packages in the GNU distribution.
3376 Other conventional output names include @code{lib} for libraries and
3377 possibly header files, @code{bin} for stand-alone programs, and
3378 @code{debug} for debugging information (@pxref{Installing Debugging
3379 Files}). The outputs of a packages are listed in the third column of
3380 the output of @command{guix package --list-available} (@pxref{Invoking
3384 @node Invoking guix gc
3385 @section Invoking @command{guix gc}
3387 @cindex garbage collector
3389 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3390 The @command{guix gc} command allows users to explicitly run the garbage
3391 collector to reclaim space from the @file{/gnu/store} directory. It is
3392 the @emph{only} way to remove files from @file{/gnu/store}---removing
3393 files or directories manually may break it beyond repair!
3396 @cindex garbage collector roots
3397 The garbage collector has a set of known @dfn{roots}: any file under
3398 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3399 cannot be deleted; any other file is considered @dfn{dead} and may be
3400 deleted. The set of garbage collector roots (``GC roots'' for short)
3401 includes default user profiles; by default, the symlinks under
3402 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3403 added with @command{guix build --root}, for example (@pxref{Invoking
3404 guix build}). The @command{guix gc --list-roots} command lists them.
3406 Prior to running @code{guix gc --collect-garbage} to make space, it is
3407 often useful to remove old generations from user profiles; that way, old
3408 package builds referenced by those generations can be reclaimed. This
3409 is achieved by running @code{guix package --delete-generations}
3410 (@pxref{Invoking guix package}).
3412 Our recommendation is to run a garbage collection periodically, or when
3413 you are short on disk space. For instance, to guarantee that at least
3414 5@tie{}GB are available on your disk, simply run:
3420 It is perfectly safe to run as a non-interactive periodic job
3421 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3422 Running @command{guix gc} with no arguments will collect as
3423 much garbage as it can, but that is often inconvenient: you may find
3424 yourself having to rebuild or re-download software that is ``dead'' from
3425 the GC viewpoint but that is necessary to build other pieces of
3426 software---e.g., the compiler tool chain.
3428 The @command{guix gc} command has three modes of operation: it can be
3429 used to garbage-collect any dead files (the default), to delete specific
3430 files (the @code{--delete} option), to print garbage-collector
3431 information, or for more advanced queries. The garbage collection
3432 options are as follows:
3435 @item --collect-garbage[=@var{min}]
3436 @itemx -C [@var{min}]
3437 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3438 sub-directories. This is the default operation when no option is
3441 When @var{min} is given, stop once @var{min} bytes have been collected.
3442 @var{min} may be a number of bytes, or it may include a unit as a
3443 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3444 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3446 When @var{min} is omitted, collect all the garbage.
3448 @item --free-space=@var{free}
3449 @itemx -F @var{free}
3450 Collect garbage until @var{free} space is available under
3451 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3452 as @code{500MiB}, as described above.
3454 When @var{free} or more is already available in @file{/gnu/store}, do
3455 nothing and exit immediately.
3457 @item --delete-generations[=@var{duration}]
3458 @itemx -d [@var{duration}]
3459 Before starting the garbage collection process, delete all the generations
3460 older than @var{duration}, for all the user profiles; when run as root, this
3461 applies to all the profiles @emph{of all the users}.
3463 For example, this command deletes all the generations of all your profiles
3464 that are older than 2 months (except generations that are current), and then
3465 proceeds to free space until at least 10 GiB are available:
3468 guix gc -d 2m -F 10G
3473 Attempt to delete all the store files and directories specified as
3474 arguments. This fails if some of the files are not in the store, or if
3475 they are still live.
3477 @item --list-failures
3478 List store items corresponding to cached build failures.
3480 This prints nothing unless the daemon was started with
3481 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3482 @option{--cache-failures}}).
3485 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3488 @item --clear-failures
3489 Remove the specified store items from the failed-build cache.
3491 Again, this option only makes sense when the daemon is started with
3492 @option{--cache-failures}. Otherwise, it does nothing.
3495 Show the list of dead files and directories still present in the
3496 store---i.e., files and directories no longer reachable from any root.
3499 Show the list of live store files and directories.
3503 In addition, the references among existing store files can be queried:
3509 @cindex package dependencies
3510 List the references (respectively, the referrers) of store files given
3516 List the requisites of the store files passed as arguments. Requisites
3517 include the store files themselves, their references, and the references
3518 of these, recursively. In other words, the returned list is the
3519 @dfn{transitive closure} of the store files.
3521 @xref{Invoking guix size}, for a tool to profile the size of the closure
3522 of an element. @xref{Invoking guix graph}, for a tool to visualize
3523 the graph of references.
3527 Return the derivation(s) leading to the given store items
3528 (@pxref{Derivations}).
3530 For example, this command:
3533 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3537 returns the @file{.drv} file(s) leading to the @code{emacs} package
3538 installed in your profile.
3540 Note that there may be zero matching @file{.drv} files, for instance
3541 because these files have been garbage-collected. There can also be more
3542 than one matching @file{.drv} due to fixed-output derivations.
3545 Lastly, the following options allow you to check the integrity of the
3546 store and to control disk usage.
3550 @item --verify[=@var{options}]
3551 @cindex integrity, of the store
3552 @cindex integrity checking
3553 Verify the integrity of the store.
3555 By default, make sure that all the store items marked as valid in the
3556 database of the daemon actually exist in @file{/gnu/store}.
3558 When provided, @var{options} must be a comma-separated list containing one
3559 or more of @code{contents} and @code{repair}.
3561 When passing @option{--verify=contents}, the daemon computes the
3562 content hash of each store item and compares it against its hash in the
3563 database. Hash mismatches are reported as data corruptions. Because it
3564 traverses @emph{all the files in the store}, this command can take a
3565 long time, especially on systems with a slow disk drive.
3567 @cindex repairing the store
3568 @cindex corruption, recovering from
3569 Using @option{--verify=repair} or @option{--verify=contents,repair}
3570 causes the daemon to try to repair corrupt store items by fetching
3571 substitutes for them (@pxref{Substitutes}). Because repairing is not
3572 atomic, and thus potentially dangerous, it is available only to the
3573 system administrator. A lightweight alternative, when you know exactly
3574 which items in the store are corrupt, is @command{guix build --repair}
3575 (@pxref{Invoking guix build}).
3578 @cindex deduplication
3579 Optimize the store by hard-linking identical files---this is
3580 @dfn{deduplication}.
3582 The daemon performs deduplication after each successful build or archive
3583 import, unless it was started with @code{--disable-deduplication}
3584 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
3585 this option is primarily useful when the daemon was running with
3586 @code{--disable-deduplication}.
3590 @node Invoking guix pull
3591 @section Invoking @command{guix pull}
3593 @cindex upgrading Guix
3594 @cindex updating Guix
3595 @cindex @command{guix pull}
3597 Packages are installed or upgraded to the latest version available in
3598 the distribution currently available on your local machine. To update
3599 that distribution, along with the Guix tools, you must run @command{guix
3600 pull}: the command downloads the latest Guix source code and package
3601 descriptions, and deploys it. Source code is downloaded from a
3602 @uref{https://git-scm.com, Git} repository, by default the official
3603 GNU@tie{}Guix repository, though this can be customized.
3605 On completion, @command{guix package} will use packages and package
3606 versions from this just-retrieved copy of Guix. Not only that, but all
3607 the Guix commands and Scheme modules will also be taken from that latest
3608 version. New @command{guix} sub-commands added by the update also
3611 Any user can update their Guix copy using @command{guix pull}, and the
3612 effect is limited to the user who run @command{guix pull}. For
3613 instance, when user @code{root} runs @command{guix pull}, this has no
3614 effect on the version of Guix that user @code{alice} sees, and vice
3617 The result of running @command{guix pull} is a @dfn{profile} available
3618 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3619 make sure to add it to the beginning of your search path so that you use
3620 the latest version, and similarly for the Info manual
3621 (@pxref{Documentation}):
3624 export PATH="$HOME/.config/guix/current/bin:$PATH"
3625 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3628 The @code{--list-generations} or @code{-l} option lists past generations
3629 produced by @command{guix pull}, along with details about their provenance:
3633 Generation 1 Jun 10 2018 00:18:18
3635 repository URL: https://git.savannah.gnu.org/git/guix.git
3636 branch: origin/master
3637 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3639 Generation 2 Jun 11 2018 11:02:49
3641 repository URL: https://git.savannah.gnu.org/git/guix.git
3642 branch: origin/master
3643 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3644 2 new packages: keepalived, libnfnetlink
3645 6 packages upgraded: emacs-nix-mode@@2.0.4,
3646 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3647 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3649 Generation 3 Jun 13 2018 23:31:07 (current)
3651 repository URL: https://git.savannah.gnu.org/git/guix.git
3652 branch: origin/master
3653 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3654 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3655 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3658 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3659 describe the current status of Guix.
3661 This @code{~/.config/guix/current} profile works like any other profile
3662 created by @command{guix package} (@pxref{Invoking guix package}). That
3663 is, you can list generations, roll back to the previous
3664 generation---i.e., the previous Guix---and so on:
3667 $ guix package -p ~/.config/guix/current --roll-back
3668 switched from generation 3 to 2
3669 $ guix package -p ~/.config/guix/current --delete-generations=1
3670 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3673 The @command{guix pull} command is usually invoked with no arguments,
3674 but it supports the following options:
3677 @item --url=@var{url}
3678 @itemx --commit=@var{commit}
3679 @itemx --branch=@var{branch}
3680 Download code for the @code{guix} channel from the specified @var{url}, at the
3681 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3682 string), or @var{branch}.
3684 @cindex @file{channels.scm}, configuration file
3685 @cindex configuration file for channels
3686 These options are provided for convenience, but you can also specify your
3687 configuration in the @file{~/.config/guix/channels.scm} file or using the
3688 @option{--channels} option (see below).
3690 @item --channels=@var{file}
3691 @itemx -C @var{file}
3692 Read the list of channels from @var{file} instead of
3693 @file{~/.config/guix/channels.scm}. @var{file} must contain Scheme code that
3694 evaluates to a list of channel objects. @xref{Channels}, for more
3699 Display the list of packages added or upgraded since the previous generation.
3701 This is the same information as displayed upon @command{guix pull} completion,
3702 but without ellipses; it is also similar to the output of @command{guix pull
3703 -l} for the last generation (see below).
3705 @item --list-generations[=@var{pattern}]
3706 @itemx -l [@var{pattern}]
3707 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3708 is provided, the subset of generations that match @var{pattern}.
3709 The syntax of @var{pattern} is the same as with @code{guix package
3710 --list-generations} (@pxref{Invoking guix package}).
3712 @xref{Invoking guix describe}, for a way to display information about the
3713 current generation only.
3715 @item --profile=@var{profile}
3716 @itemx -p @var{profile}
3717 Use @var{profile} instead of @file{~/.config/guix/current}.
3721 Show which channel commit(s) would be used and what would be built or
3722 substituted but do not actually do it.
3724 @item --system=@var{system}
3725 @itemx -s @var{system}
3726 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3727 the system type of the build host.
3730 Produce verbose output, writing build logs to the standard error output.
3733 Use the bootstrap Guile to build the latest Guix. This option is only
3734 useful to Guix developers.
3737 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3738 repository and branch to pull from, as well as @emph{additional} repositories
3739 containing package modules that should be deployed. @xref{Channels}, for more
3742 In addition, @command{guix pull} supports all the common build options
3743 (@pxref{Common Build Options}).
3749 @cindex @file{channels.scm}, configuration file
3750 @cindex configuration file for channels
3751 @cindex @command{guix pull}, configuration file
3752 @cindex configuration of @command{guix pull}
3753 Guix and its package collection are updated by running @command{guix pull}
3754 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3755 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3756 customized by defining @dfn{channels} in the
3757 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3758 of a Git repository to be deployed, and @command{guix pull} can be instructed
3759 to pull from one or more channels. In other words, channels can be used to
3760 @emph{customize} and to @emph{extend} Guix, as we will see below.
3762 @subsection Using a Custom Guix Channel
3764 The channel called @code{guix} specifies where Guix itself---its command-line
3765 tools as well as its package collection---should be downloaded. For instance,
3766 suppose you want to update from your own copy of the Guix repository at
3767 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3768 write in @code{~/.config/guix/channels.scm} this specification:
3771 ;; Tell 'guix pull' to use my own repo.
3774 (url "https://example.org/my-guix.git")
3775 (branch "super-hacks")))
3779 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3780 branch of the repository at @code{example.org}.
3782 @subsection Specifying Additional Channels
3784 @cindex extending the package collection (channels)
3785 @cindex personal packages (channels)
3786 @cindex channels, for personal packages
3787 You can also specify @emph{additional channels} to pull from. Let's say you
3788 have a bunch of custom package variants or personal packages that you think
3789 would make little sense to contribute to the Guix project, but would like to
3790 have these packages transparently available to you at the command line. You
3791 would first write modules containing those package definitions (@pxref{Package
3792 Modules}), maintain them in a Git repository, and then you and anyone else can
3793 use it as an additional channel to get packages from. Neat, no?
3795 @c What follows stems from discussions at
3796 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3797 @c earlier discussions on guix-devel@gnu.org.
3799 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3800 publish your personal channel to the world, we would like to share a few words
3805 Before publishing a channel, please consider contributing your package
3806 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3807 to free software of all sorts, and packages in Guix proper are readily
3808 available to all Guix users and benefit from the project's quality assurance
3812 When you maintain package definitions outside Guix, we, Guix developers,
3813 consider that @emph{the compatibility burden is on you}. Remember that
3814 package modules and package definitions are just Scheme code that uses various
3815 programming interfaces (APIs). We want to remain free to change these APIs to
3816 keep improving Guix, possibly in ways that break your channel. We never
3817 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3821 Corollary: if you're using an external channel and that channel breaks, please
3822 @emph{report the issue to the channel authors}, not to the Guix project.
3825 You've been warned! Having said this, we believe external channels are a
3826 practical way to exert your freedom to augment Guix' package collection and to
3827 share your improvements, which are basic tenets of
3828 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3829 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3832 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
3833 @command{guix pull} to pull from it @emph{in addition} to the default Guix
3836 @vindex %default-channels
3838 ;; Add my personal packages to those Guix provides.
3840 (name 'my-personal-packages)
3841 (url "https://example.org/personal-packages.git"))
3846 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3847 add a channel the list of channels that the variable @code{%default-channels}
3848 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3849 Manual}). With this file in place, @command{guix pull} builds not only Guix
3850 but also the package modules from your own repository. The result in
3851 @file{~/.config/guix/current} is the union of Guix with your own package
3855 $ guix pull --list-generations
3857 Generation 19 Aug 27 2018 16:20:48
3859 repository URL: https://git.savannah.gnu.org/git/guix.git
3861 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
3862 my-personal-packages dd3df5e
3863 repository URL: https://example.org/personal-packages.git
3865 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
3866 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
3867 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
3871 The output of @command{guix pull} above shows that Generation@tie{}19 includes
3872 both Guix and packages from the @code{my-personal-packages} channel. Among
3873 the new and upgraded packages that are listed, some like @code{my-gimp} and
3874 @code{my-emacs-with-cool-features} might come from
3875 @code{my-personal-packages}, while others come from the Guix default channel.
3877 To create a channel, create a Git repository containing your own package
3878 modules and make it available. The repository can contain anything, but a
3879 useful channel will contain Guile modules that export packages. Once you
3880 start using a channel, Guix will behave as if the root directory of that
3881 channel's Git repository has been added to the Guile load path (@pxref{Load
3882 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
3883 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
3884 module, then the module will be available under the name @code{(my-packages
3885 my-tools)}, and you will be able to use it like any other module
3886 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
3888 @cindex dependencies, channels
3889 @cindex meta-data, channels
3890 @subsection Declaring Channel Dependencies
3892 Channel authors may decide to augment a package collection provided by other
3893 channels. They can declare their channel to be dependent on other channels in
3894 a meta-data file @file{.guix-channel}, which is to be placed in the root of
3895 the channel repository.
3897 The meta-data file should contain a simple S-expression like this:
3904 (name some-collection)
3905 (url "https://example.org/first-collection.git"))
3907 (name some-other-collection)
3908 (url "https://example.org/second-collection.git")
3909 (branch "testing"))))
3912 In the above example this channel is declared to depend on two other channels,
3913 which will both be fetched automatically. The modules provided by the channel
3914 will be compiled in an environment where the modules of all these declared
3915 channels are available.
3917 For the sake of reliability and maintainability, you should avoid dependencies
3918 on channels that you don't control, and you should aim to keep the number of
3919 dependencies to a minimum.
3921 @subsection Replicating Guix
3923 @cindex pinning, channels
3924 @cindex replicating Guix
3925 @cindex reproducibility, of Guix
3926 The @command{guix pull --list-generations} output above shows precisely which
3927 commits were used to build this instance of Guix. We can thus replicate it,
3928 say, on another machine, by providing a channel specification in
3929 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
3932 ;; Deploy specific commits of my channels of interest.
3935 (url "https://git.savannah.gnu.org/git/guix.git")
3936 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
3938 (name 'my-personal-packages)
3939 (url "https://example.org/personal-packages.git")
3940 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
3943 The @command{guix describe --format=channels} command can even generate this
3944 list of channels directly (@pxref{Invoking guix describe}).
3946 At this point the two machines run the @emph{exact same Guix}, with access to
3947 the @emph{exact same packages}. The output of @command{guix build gimp} on
3948 one machine will be exactly the same, bit for bit, as the output of the same
3949 command on the other machine. It also means both machines have access to all
3950 the source code of Guix and, transitively, to all the source code of every
3953 This gives you super powers, allowing you to track the provenance of binary
3954 artifacts with very fine grain, and to reproduce software environments at
3955 will---some sort of ``meta reproducibility'' capabilities, if you will.
3956 @xref{Inferiors}, for another way to take advantage of these super powers.
3961 @c TODO: Remove this once we're more confident about API stability.
3963 The functionality described here is a ``technology preview'' as of version
3964 @value{VERSION}. As such, the interface is subject to change.
3968 @cindex composition of Guix revisions
3969 Sometimes you might need to mix packages from the revision of Guix you're
3970 currently running with packages available in a different revision of Guix.
3971 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
3972 revisions in arbitrary ways.
3974 @cindex inferior packages
3975 Technically, an ``inferior'' is essentially a separate Guix process connected
3976 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
3977 @code{(guix inferior)} module allows you to create inferiors and to
3978 communicate with them. It also provides a high-level interface to browse and
3979 manipulate the packages that an inferior provides---@dfn{inferior packages}.
3981 When combined with channels (@pxref{Channels}), inferiors provide a simple way
3982 to interact with a separate revision of Guix. For example, let's assume you
3983 want to install in your profile the current @code{guile} package, along with
3984 the @code{guile-json} as it existed in an older revision of Guix---perhaps
3985 because the newer @code{guile-json} has an incompatible API and you want to
3986 run your code against the old API@. To do that, you could write a manifest for
3987 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
3988 manifest, you would create an inferior for that old Guix revision you care
3989 about, and you would look up the @code{guile-json} package in the inferior:
3992 (use-modules (guix inferior) (guix channels)
3993 (srfi srfi-1)) ;for 'first'
3996 ;; This is the old revision from which we want to
3997 ;; extract guile-json.
4000 (url "https://git.savannah.gnu.org/git/guix.git")
4002 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4005 ;; An inferior representing the above revision.
4006 (inferior-for-channels channels))
4008 ;; Now create a manifest with the current "guile" package
4009 ;; and the old "guile-json" package.
4011 (list (first (lookup-inferior-packages inferior "guile-json"))
4012 (specification->package "guile")))
4015 On its first run, @command{guix package --manifest} might have to build the
4016 channel you specified before it can create the inferior; subsequent runs will
4017 be much faster because the Guix revision will be cached.
4019 The @code{(guix inferior)} module provides the following procedures to open an
4022 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4023 [#:cache-directory] [#:ttl]
4024 Return an inferior for @var{channels}, a list of channels. Use the cache at
4025 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4026 This procedure opens a new connection to the build daemon.
4028 As a side effect, this procedure may build or substitute binaries for
4029 @var{channels}, which can take time.
4032 @deffn {Scheme Procedure} open-inferior @var{directory} @
4033 [#:command "bin/guix"]
4034 Open the inferior Guix in @var{directory}, running
4035 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4036 the inferior could not be launched.
4039 @cindex inferior packages
4040 The procedures listed below allow you to obtain and manipulate inferior
4043 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4044 Return the list of packages known to @var{inferior}.
4047 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4049 Return the sorted list of inferior packages matching @var{name} in
4050 @var{inferior}, with highest version numbers first. If @var{version} is true,
4051 return only packages with a version number prefixed by @var{version}.
4054 @deffn {Scheme Procedure} inferior-package? @var{obj}
4055 Return true if @var{obj} is an inferior package.
4058 @deffn {Scheme Procedure} inferior-package-name @var{package}
4059 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4060 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4061 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4062 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4063 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4064 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4065 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4066 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4067 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4068 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4069 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4070 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4071 These procedures are the counterpart of package record accessors
4072 (@pxref{package Reference}). Most of them work by querying the inferior
4073 @var{package} comes from, so the inferior must still be live when you call
4077 Inferior packages can be used transparently like any other package or
4078 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4079 transparently handled by the @code{packages->manifest} procedure, which is
4080 commonly use in manifests (@pxref{Invoking guix package, the
4081 @option{--manifest} option of @command{guix package}}). Thus you can insert
4082 an inferior package pretty much anywhere you would insert a regular package:
4083 in manifests, in the @code{packages} field of your @code{operating-system}
4084 declaration, and so on.
4086 @node Invoking guix describe
4087 @section Invoking @command{guix describe}
4089 @cindex reproducibility
4090 @cindex replicating Guix
4091 Often you may want to answer questions like: ``Which revision of Guix am I
4092 using?'' or ``Which channels am I using?'' This is useful information in many
4093 situations: if you want to @emph{replicate} an environment on a different
4094 machine or user account, if you want to report a bug or to determine what
4095 change in the channels you are using caused it, or if you want to record your
4096 system state for reproducibility purposes. The @command{guix describe}
4097 command answers these questions.
4099 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4100 displays the channel(s) that it was built from, including their repository URL
4101 and commit IDs (@pxref{Channels}):
4105 Generation 10 Sep 03 2018 17:32:44 (current)
4107 repository URL: https://git.savannah.gnu.org/git/guix.git
4109 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4112 If you're familiar with the Git version control system, this is similar in
4113 spirit to @command{git describe}; the output is also similar to that of
4114 @command{guix pull --list-generations}, but limited to the current generation
4115 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4116 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4117 information is all it takes to describe the revision of Guix you're using, and
4118 also to replicate it.
4120 To make it easier to replicate Guix, @command{guix describe} can also be asked
4121 to return a list of channels instead of the human-readable description above:
4124 $ guix describe -f channels
4127 (url "https://git.savannah.gnu.org/git/guix.git")
4129 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4133 You can save this to a file and feed it to @command{guix pull -C} on some
4134 other machine or at a later point in time, which will instantiate @emph{this
4135 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4136 From there on, since you're able to deploy the same revision of Guix, you can
4137 just as well @emph{replicate a complete software environment}. We humbly
4138 think that this is @emph{awesome}, and we hope you'll like it too!
4140 The details of the options supported by @command{guix describe} are as
4144 @item --format=@var{format}
4145 @itemx -f @var{format}
4146 Produce output in the specified @var{format}, one of:
4150 produce human-readable output;
4152 produce a list of channel specifications that can be passed to @command{guix
4153 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4157 produce a list of channel specifications in JSON format;
4159 produce a list of channel specifications in Recutils format.
4162 @item --profile=@var{profile}
4163 @itemx -p @var{profile}
4164 Display information about @var{profile}.
4167 @node Invoking guix archive
4168 @section Invoking @command{guix archive}
4170 @cindex @command{guix archive}
4172 The @command{guix archive} command allows users to @dfn{export} files
4173 from the store into a single archive, and to later @dfn{import} them on
4174 a machine that runs Guix.
4175 In particular, it allows store files to be transferred from one machine
4176 to the store on another machine.
4179 If you're looking for a way to produce archives in a format suitable for
4180 tools other than Guix, @pxref{Invoking guix pack}.
4183 @cindex exporting store items
4184 To export store files as an archive to standard output, run:
4187 guix archive --export @var{options} @var{specifications}...
4190 @var{specifications} may be either store file names or package
4191 specifications, as for @command{guix package} (@pxref{Invoking guix
4192 package}). For instance, the following command creates an archive
4193 containing the @code{gui} output of the @code{git} package and the main
4194 output of @code{emacs}:
4197 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4200 If the specified packages are not built yet, @command{guix archive}
4201 automatically builds them. The build process may be controlled with the
4202 common build options (@pxref{Common Build Options}).
4204 To transfer the @code{emacs} package to a machine connected over SSH,
4208 guix archive --export -r emacs | ssh the-machine guix archive --import
4212 Similarly, a complete user profile may be transferred from one machine
4213 to another like this:
4216 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4217 ssh the-machine guix-archive --import
4221 However, note that, in both examples, all of @code{emacs} and the
4222 profile as well as all of their dependencies are transferred (due to
4223 @code{-r}), regardless of what is already available in the store on the
4224 target machine. The @code{--missing} option can help figure out which
4225 items are missing from the target store. The @command{guix copy}
4226 command simplifies and optimizes this whole process, so this is probably
4227 what you should use in this case (@pxref{Invoking guix copy}).
4229 @cindex nar, archive format
4230 @cindex normalized archive (nar)
4231 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4232 comparable in spirit to `tar', but with differences
4233 that make it more appropriate for our purposes. First, rather than
4234 recording all Unix metadata for each file, the nar format only mentions
4235 the file type (regular, directory, or symbolic link); Unix permissions
4236 and owner/group are dismissed. Second, the order in which directory
4237 entries are stored always follows the order of file names according to
4238 the C locale collation order. This makes archive production fully
4241 When exporting, the daemon digitally signs the contents of the archive,
4242 and that digital signature is appended. When importing, the daemon
4243 verifies the signature and rejects the import in case of an invalid
4244 signature or if the signing key is not authorized.
4245 @c FIXME: Add xref to daemon doc about signatures.
4247 The main options are:
4251 Export the specified store files or packages (see below.) Write the
4252 resulting archive to the standard output.
4254 Dependencies are @emph{not} included in the output, unless
4255 @code{--recursive} is passed.
4259 When combined with @code{--export}, this instructs @command{guix
4260 archive} to include dependencies of the given items in the archive.
4261 Thus, the resulting archive is self-contained: it contains the closure
4262 of the exported store items.
4265 Read an archive from the standard input, and import the files listed
4266 therein into the store. Abort if the archive has an invalid digital
4267 signature, or if it is signed by a public key not among the authorized
4268 keys (see @code{--authorize} below.)
4271 Read a list of store file names from the standard input, one per line,
4272 and write on the standard output the subset of these files missing from
4275 @item --generate-key[=@var{parameters}]
4276 @cindex signing, archives
4277 Generate a new key pair for the daemon. This is a prerequisite before
4278 archives can be exported with @code{--export}. Note that this operation
4279 usually takes time, because it needs to gather enough entropy to
4280 generate the key pair.
4282 The generated key pair is typically stored under @file{/etc/guix}, in
4283 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4284 key, which must be kept secret.) When @var{parameters} is omitted,
4285 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4286 versions before 1.6.0, it is a 4096-bit RSA key.
4287 Alternatively, @var{parameters} can specify
4288 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4289 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4290 Libgcrypt Reference Manual}).
4293 @cindex authorizing, archives
4294 Authorize imports signed by the public key passed on standard input.
4295 The public key must be in ``s-expression advanced format''---i.e., the
4296 same format as the @file{signing-key.pub} file.
4298 The list of authorized keys is kept in the human-editable file
4299 @file{/etc/guix/acl}. The file contains
4300 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4301 s-expressions''} and is structured as an access-control list in the
4302 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4305 @item --extract=@var{directory}
4306 @itemx -x @var{directory}
4307 Read a single-item archive as served by substitute servers
4308 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4309 low-level operation needed in only very narrow use cases; see below.
4311 For example, the following command extracts the substitute for Emacs
4312 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4316 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
4317 | bunzip2 | guix archive -x /tmp/emacs
4320 Single-item archives are different from multiple-item archives produced
4321 by @command{guix archive --export}; they contain a single store item,
4322 and they do @emph{not} embed a signature. Thus this operation does
4323 @emph{no} signature verification and its output should be considered
4326 The primary purpose of this operation is to facilitate inspection of
4327 archive contents coming from possibly untrusted substitute servers.
4332 @c *********************************************************************
4334 @chapter Development
4336 @cindex software development
4337 If you are a software developer, Guix provides tools that you should find
4338 helpful---independently of the language you're developing in. This is what
4339 this chapter is about.
4341 The @command{guix environment} command provides a convenient way to set up
4342 @dfn{development environments} containing all the dependencies and tools
4343 necessary to work on the software package of your choice. The @command{guix
4344 pack} command allows you to create @dfn{application bundles} that can be
4345 easily distributed to users who do not run Guix.
4348 * Invoking guix environment:: Setting up development environments.
4349 * Invoking guix pack:: Creating software bundles.
4352 @node Invoking guix environment
4353 @section Invoking @command{guix environment}
4355 @cindex reproducible build environments
4356 @cindex development environments
4357 @cindex @command{guix environment}
4358 @cindex environment, package build environment
4359 The purpose of @command{guix environment} is to assist hackers in
4360 creating reproducible development environments without polluting their
4361 package profile. The @command{guix environment} tool takes one or more
4362 packages, builds all of their inputs, and creates a shell
4363 environment to use them.
4365 The general syntax is:
4368 guix environment @var{options} @var{package}@dots{}
4371 The following example spawns a new shell set up for the development of
4375 guix environment guile
4378 If the needed dependencies are not built yet, @command{guix environment}
4379 automatically builds them. The environment of the new shell is an augmented
4380 version of the environment that @command{guix environment} was run in.
4381 It contains the necessary search paths for building the given package
4382 added to the existing environment variables. To create a ``pure''
4383 environment, in which the original environment variables have been unset,
4384 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
4385 environment variables such as @code{PATH} in their @file{~/.bashrc}
4386 file. As a consequence, when @code{guix environment} launches it, Bash
4387 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
4388 environment variables. It is an error to define such environment
4389 variables in @file{.bashrc}; instead, they should be defined in
4390 @file{.bash_profile}, which is sourced only by log-in shells.
4391 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
4392 details on Bash start-up files.}.
4394 @vindex GUIX_ENVIRONMENT
4395 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
4396 variable in the shell it spawns; its value is the file name of the
4397 profile of this environment. This allows users to, say, define a
4398 specific prompt for development environments in their @file{.bashrc}
4399 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4402 if [ -n "$GUIX_ENVIRONMENT" ]
4404 export PS1="\u@@\h \w [dev]\$ "
4409 ...@: or to browse the profile:
4412 $ ls "$GUIX_ENVIRONMENT/bin"
4415 Additionally, more than one package may be specified, in which case the
4416 union of the inputs for the given packages are used. For example, the
4417 command below spawns a shell where all of the dependencies of both Guile
4418 and Emacs are available:
4421 guix environment guile emacs
4424 Sometimes an interactive shell session is not desired. An arbitrary
4425 command may be invoked by placing the @code{--} token to separate the
4426 command from the rest of the arguments:
4429 guix environment guile -- make -j4
4432 In other situations, it is more convenient to specify the list of
4433 packages needed in the environment. For example, the following command
4434 runs @command{python} from an environment containing Python@tie{}2.7 and
4438 guix environment --ad-hoc python2-numpy python-2.7 -- python
4441 Furthermore, one might want the dependencies of a package and also some
4442 additional packages that are not build-time or runtime dependencies, but
4443 are useful when developing nonetheless. Because of this, the
4444 @code{--ad-hoc} flag is positional. Packages appearing before
4445 @code{--ad-hoc} are interpreted as packages whose dependencies will be
4446 added to the environment. Packages appearing after are interpreted as
4447 packages that will be added to the environment directly. For example,
4448 the following command creates a Guix development environment that
4449 additionally includes Git and strace:
4452 guix environment guix --ad-hoc git strace
4455 Sometimes it is desirable to isolate the environment as much as
4456 possible, for maximal purity and reproducibility. In particular, when
4457 using Guix on a host distro that is not Guix System, it is desirable to
4458 prevent access to @file{/usr/bin} and other system-wide resources from
4459 the development environment. For example, the following command spawns
4460 a Guile REPL in a ``container'' where only the store and the current
4461 working directory are mounted:
4464 guix environment --ad-hoc --container guile -- guile
4468 The @code{--container} option requires Linux-libre 3.19 or newer.
4471 The available options are summarized below.
4474 @item --root=@var{file}
4475 @itemx -r @var{file}
4476 @cindex persistent environment
4477 @cindex garbage collector root, for environments
4478 Make @var{file} a symlink to the profile for this environment, and
4479 register it as a garbage collector root.
4481 This is useful if you want to protect your environment from garbage
4482 collection, to make it ``persistent''.
4484 When this option is omitted, the environment is protected from garbage
4485 collection only for the duration of the @command{guix environment}
4486 session. This means that next time you recreate the same environment,
4487 you could have to rebuild or re-download packages. @xref{Invoking guix
4488 gc}, for more on GC roots.
4490 @item --expression=@var{expr}
4491 @itemx -e @var{expr}
4492 Create an environment for the package or list of packages that
4493 @var{expr} evaluates to.
4495 For example, running:
4498 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4501 starts a shell with the environment for this specific variant of the
4507 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4510 starts a shell with all the base system packages available.
4512 The above commands only use the default output of the given packages.
4513 To select other outputs, two element tuples can be specified:
4516 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4519 @item --load=@var{file}
4520 @itemx -l @var{file}
4521 Create an environment for the package or list of packages that the code
4522 within @var{file} evaluates to.
4524 As an example, @var{file} might contain a definition like this
4525 (@pxref{Defining Packages}):
4528 @verbatiminclude environment-gdb.scm
4531 @item --manifest=@var{file}
4532 @itemx -m @var{file}
4533 Create an environment for the packages contained in the manifest object
4534 returned by the Scheme code in @var{file}.
4536 This is similar to the same-named option in @command{guix package}
4537 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4541 Include all specified packages in the resulting environment, as if an
4542 @i{ad hoc} package were defined with them as inputs. This option is
4543 useful for quickly creating an environment without having to write a
4544 package expression to contain the desired inputs.
4546 For instance, the command:
4549 guix environment --ad-hoc guile guile-sdl -- guile
4552 runs @command{guile} in an environment where Guile and Guile-SDL are
4555 Note that this example implicitly asks for the default output of
4556 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4557 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4558 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4560 This option may be composed with the default behavior of @command{guix
4561 environment}. Packages appearing before @code{--ad-hoc} are interpreted
4562 as packages whose dependencies will be added to the environment, the
4563 default behavior. Packages appearing after are interpreted as packages
4564 that will be added to the environment directly.
4567 Unset existing environment variables when building the new environment, except
4568 those specified with @option{--preserve} (see below.) This has the effect of
4569 creating an environment in which search paths only contain package inputs.
4571 @item --preserve=@var{regexp}
4572 @itemx -E @var{regexp}
4573 When used alongside @option{--pure}, preserve the environment variables
4574 matching @var{regexp}---in other words, put them on a ``white list'' of
4575 environment variables that must be preserved. This option can be repeated
4579 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4583 This example runs @command{mpirun} in a context where the only environment
4584 variables defined are @code{PATH}, environment variables whose name starts
4585 with @code{SLURM}, as well as the usual ``precious'' variables (@code{HOME},
4588 @item --search-paths
4589 Display the environment variable definitions that make up the
4592 @item --system=@var{system}
4593 @itemx -s @var{system}
4594 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4599 Run @var{command} within an isolated container. The current working
4600 directory outside the container is mapped inside the container.
4601 Additionally, unless overridden with @code{--user}, a dummy home
4602 directory is created that matches the current user's home directory, and
4603 @file{/etc/passwd} is configured accordingly.
4605 The spawned process runs as the current user outside the container. Inside
4606 the container, it has the same UID and GID as the current user, unless
4607 @option{--user} is passed (see below.)
4611 For containers, share the network namespace with the host system.
4612 Containers created without this flag only have access to the loopback
4615 @item --link-profile
4617 For containers, link the environment profile to
4618 @file{~/.guix-profile} within the container. This is equivalent to
4619 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
4620 within the container. Linking will fail and abort the environment if
4621 the directory already exists, which will certainly be the case if
4622 @command{guix environment} was invoked in the user's home directory.
4624 Certain packages are configured to look in
4625 @code{~/.guix-profile} for configuration files and data;@footnote{For
4626 example, the @code{fontconfig} package inspects
4627 @file{~/.guix-profile/share/fonts} for additional fonts.}
4628 @code{--link-profile} allows these programs to behave as expected within
4631 @item --user=@var{user}
4632 @itemx -u @var{user}
4633 For containers, use the username @var{user} in place of the current
4634 user. The generated @file{/etc/passwd} entry within the container will
4635 contain the name @var{user}, the home directory will be
4636 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4637 the UID and GID inside the container are 1000. @var{user}
4638 need not exist on the system.
4640 Additionally, any shared or exposed path (see @code{--share} and
4641 @code{--expose} respectively) whose target is within the current user's
4642 home directory will be remapped relative to @file{/home/USER}; this
4643 includes the automatic mapping of the current working directory.
4646 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4648 guix environment --container --user=foo \
4649 --expose=$HOME/test \
4650 --expose=/tmp/target=$HOME/target
4653 While this will limit the leaking of user identity through home paths
4654 and each of the user fields, this is only one useful component of a
4655 broader privacy/anonymity solution---not one in and of itself.
4657 @item --expose=@var{source}[=@var{target}]
4658 For containers, expose the file system @var{source} from the host system
4659 as the read-only file system @var{target} within the container. If
4660 @var{target} is not specified, @var{source} is used as the target mount
4661 point in the container.
4663 The example below spawns a Guile REPL in a container in which the user's
4664 home directory is accessible read-only via the @file{/exchange}
4668 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
4671 @item --share=@var{source}[=@var{target}]
4672 For containers, share the file system @var{source} from the host system
4673 as the writable file system @var{target} within the container. If
4674 @var{target} is not specified, @var{source} is used as the target mount
4675 point in the container.
4677 The example below spawns a Guile REPL in a container in which the user's
4678 home directory is accessible for both reading and writing via the
4679 @file{/exchange} directory:
4682 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
4686 @command{guix environment}
4687 also supports all of the common build options that @command{guix
4688 build} supports (@pxref{Common Build Options}) as well as package
4689 transformation options (@pxref{Package Transformation Options}).
4691 @node Invoking guix pack
4692 @section Invoking @command{guix pack}
4694 Occasionally you want to pass software to people who are not (yet!)
4695 lucky enough to be using Guix. You'd tell them to run @command{guix
4696 package -i @var{something}}, but that's not possible in this case. This
4697 is where @command{guix pack} comes in.
4700 If you are looking for ways to exchange binaries among machines that
4701 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
4702 publish}, and @ref{Invoking guix archive}.
4707 @cindex application bundle
4708 @cindex software bundle
4709 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
4710 @dfn{software bundle}: it creates a tarball or some other archive
4711 containing the binaries of the software you're interested in, and all
4712 its dependencies. The resulting archive can be used on any machine that
4713 does not have Guix, and people can run the exact same binaries as those
4714 you have with Guix. The pack itself is created in a bit-reproducible
4715 fashion, so anyone can verify that it really contains the build results
4716 that you pretend to be shipping.
4718 For example, to create a bundle containing Guile, Emacs, Geiser, and all
4719 their dependencies, you can run:
4722 $ guix pack guile emacs geiser
4724 /gnu/store/@dots{}-pack.tar.gz
4727 The result here is a tarball containing a @file{/gnu/store} directory
4728 with all the relevant packages. The resulting tarball contains a
4729 @dfn{profile} with the three packages of interest; the profile is the
4730 same as would be created by @command{guix package -i}. It is this
4731 mechanism that is used to create Guix's own standalone binary tarball
4732 (@pxref{Binary Installation}).
4734 Users of this pack would have to run
4735 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
4736 find inconvenient. To work around it, you can create, say, a
4737 @file{/opt/gnu/bin} symlink to the profile:
4740 guix pack -S /opt/gnu/bin=bin guile emacs geiser
4744 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
4746 @cindex relocatable binaries, with @command{guix pack}
4747 What if the recipient of your pack does not have root privileges on
4748 their machine, and thus cannot unpack it in the root file system? In
4749 that case, you will want to use the @code{--relocatable} option (see
4750 below). This option produces @dfn{relocatable binaries}, meaning they
4751 they can be placed anywhere in the file system hierarchy: in the example
4752 above, users can unpack your tarball in their home directory and
4753 directly run @file{./opt/gnu/bin/guile}.
4755 @cindex Docker, build an image with guix pack
4756 Alternatively, you can produce a pack in the Docker image format using
4757 the following command:
4760 guix pack -f docker guile emacs geiser
4764 The result is a tarball that can be passed to the @command{docker load}
4766 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
4767 documentation} for more information.
4769 @cindex Singularity, build an image with guix pack
4770 @cindex SquashFS, build an image with guix pack
4771 Yet another option is to produce a SquashFS image with the following
4775 guix pack -f squashfs guile emacs geiser
4779 The result is a SquashFS file system image that can either be mounted or
4780 directly be used as a file system container image with the
4781 @uref{https://singularity.lbl.gov, Singularity container execution
4782 environment}, using commands like @command{singularity shell} or
4783 @command{singularity exec}.
4785 Several command-line options allow you to customize your pack:
4788 @item --format=@var{format}
4789 @itemx -f @var{format}
4790 Produce a pack in the given @var{format}.
4792 The available formats are:
4796 This is the default format. It produces a tarball containing all the
4797 specified binaries and symlinks.
4800 This produces a tarball that follows the
4801 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
4802 Docker Image Specification}.
4805 This produces a SquashFS image containing all the specified binaries and
4806 symlinks, as well as empty mount points for virtual file systems like
4810 @cindex relocatable binaries
4813 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
4814 anywhere in the file system hierarchy and run from there.
4816 When this option is passed once, the resulting binaries require support for
4817 @dfn{user namespaces} in the kernel Linux; when passed
4818 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
4819 PRoot support, can be thought of as the abbreviation of ``Really
4820 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
4821 if user namespaces are unavailable, and essentially work anywhere---see below
4822 for the implications.
4824 For example, if you create a pack containing Bash with:
4827 guix pack -RR -S /mybin=bin bash
4831 ...@: you can copy that pack to a machine that lacks Guix, and from your
4832 home directory as a normal user, run:
4840 In that shell, if you type @code{ls /gnu/store}, you'll notice that
4841 @file{/gnu/store} shows up and contains all the dependencies of
4842 @code{bash}, even though the machine actually lacks @file{/gnu/store}
4843 altogether! That is probably the simplest way to deploy Guix-built
4844 software on a non-Guix machine.
4847 By default, relocatable binaries rely on the @dfn{user namespace} feature of
4848 the kernel Linux, which allows unprivileged users to mount or change root.
4849 Old versions of Linux did not support it, and some GNU/Linux distributions
4852 To produce relocatable binaries that work even in the absence of user
4853 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
4854 case, binaries will try user namespace support and fall back to PRoot if user
4855 namespaces are not supported.
4857 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
4858 support for file system virtualization. It achieves that by using the
4859 @code{ptrace} system call on the running program. This approach has the
4860 advantage to work without requiring special kernel support, but it incurs
4861 run-time overhead every time a system call is made.
4864 @item --expression=@var{expr}
4865 @itemx -e @var{expr}
4866 Consider the package @var{expr} evaluates to.
4868 This has the same purpose as the same-named option in @command{guix
4869 build} (@pxref{Additional Build Options, @code{--expression} in
4870 @command{guix build}}).
4872 @item --manifest=@var{file}
4873 @itemx -m @var{file}
4874 Use the packages contained in the manifest object returned by the Scheme
4877 This has a similar purpose as the same-named option in @command{guix
4878 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
4879 same manifest files. It allows you to define a collection of packages
4880 once and use it both for creating profiles and for creating archives
4881 for use on machines that do not have Guix installed. Note that you can
4882 specify @emph{either} a manifest file @emph{or} a list of packages,
4885 @item --system=@var{system}
4886 @itemx -s @var{system}
4887 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4888 the system type of the build host.
4890 @item --target=@var{triplet}
4891 @cindex cross-compilation
4892 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
4893 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
4894 configuration triplets,, autoconf, Autoconf}).
4896 @item --compression=@var{tool}
4897 @itemx -C @var{tool}
4898 Compress the resulting tarball using @var{tool}---one of @code{gzip},
4899 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
4901 @item --symlink=@var{spec}
4902 @itemx -S @var{spec}
4903 Add the symlinks specified by @var{spec} to the pack. This option can
4904 appear several times.
4906 @var{spec} has the form @code{@var{source}=@var{target}}, where
4907 @var{source} is the symlink that will be created and @var{target} is the
4910 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
4911 symlink pointing to the @file{bin} sub-directory of the profile.
4913 @item --save-provenance
4914 Save provenance information for the packages passed on the command line.
4915 Provenance information includes the URL and commit of the channels in use
4918 Provenance information is saved in the
4919 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
4920 usual package metadata---the name and version of each package, their
4921 propagated inputs, and so on. It is useful information to the recipient of
4922 the pack, who then knows how the pack was (supposedly) obtained.
4924 This option is not enabled by default because, like timestamps, provenance
4925 information contributes nothing to the build process. In other words, there
4926 is an infinity of channel URLs and commit IDs that can lead to the same pack.
4927 Recording such ``silent'' metadata in the output thus potentially breaks the
4928 source-to-binary bitwise reproducibility property.
4930 @item --localstatedir
4931 @itemx --profile-name=@var{name}
4932 Include the ``local state directory'', @file{/var/guix}, in the resulting
4933 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
4934 profile---by default @var{name} is @code{guix-profile}, which corresponds to
4935 @file{~root/.guix-profile}.
4937 @file{/var/guix} contains the store database (@pxref{The Store}) as well
4938 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
4939 the pack means that the store is ``complete'' and manageable by Guix;
4940 not providing it pack means that the store is ``dead'': items cannot be
4941 added to it or removed from it after extraction of the pack.
4943 One use case for this is the Guix self-contained binary tarball
4944 (@pxref{Binary Installation}).
4947 Use the bootstrap binaries to build the pack. This option is only
4948 useful to Guix developers.
4951 In addition, @command{guix pack} supports all the common build options
4952 (@pxref{Common Build Options}) and all the package transformation
4953 options (@pxref{Package Transformation Options}).
4956 @c *********************************************************************
4957 @node Programming Interface
4958 @chapter Programming Interface
4960 GNU Guix provides several Scheme programming interfaces (APIs) to
4961 define, build, and query packages. The first interface allows users to
4962 write high-level package definitions. These definitions refer to
4963 familiar packaging concepts, such as the name and version of a package,
4964 its build system, and its dependencies. These definitions can then be
4965 turned into concrete build actions.
4967 Build actions are performed by the Guix daemon, on behalf of users. In a
4968 standard setup, the daemon has write access to the store---the
4969 @file{/gnu/store} directory---whereas users do not. The recommended
4970 setup also has the daemon perform builds in chroots, under a specific
4971 build users, to minimize interference with the rest of the system.
4974 Lower-level APIs are available to interact with the daemon and the
4975 store. To instruct the daemon to perform a build action, users actually
4976 provide it with a @dfn{derivation}. A derivation is a low-level
4977 representation of the build actions to be taken, and the environment in
4978 which they should occur---derivations are to package definitions what
4979 assembly is to C programs. The term ``derivation'' comes from the fact
4980 that build results @emph{derive} from them.
4982 This chapter describes all these APIs in turn, starting from high-level
4983 package definitions.
4986 * Package Modules:: Packages from the programmer's viewpoint.
4987 * Defining Packages:: Defining new packages.
4988 * Build Systems:: Specifying how packages are built.
4989 * The Store:: Manipulating the package store.
4990 * Derivations:: Low-level interface to package derivations.
4991 * The Store Monad:: Purely functional interface to the store.
4992 * G-Expressions:: Manipulating build expressions.
4993 * Invoking guix repl:: Fiddling with Guix interactively.
4996 @node Package Modules
4997 @section Package Modules
4999 From a programming viewpoint, the package definitions of the
5000 GNU distribution are provided by Guile modules in the @code{(gnu packages
5001 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5002 packages @dots{})} module name space are not necessarily ``GNU
5003 packages''. This module naming scheme follows the usual Guile module
5004 naming convention: @code{gnu} means that these modules are distributed
5005 as part of the GNU system, and @code{packages} identifies modules that
5006 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5007 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5008 module exports a variable named @code{emacs}, which is bound to a
5009 @code{<package>} object (@pxref{Defining Packages}).
5011 The @code{(gnu packages @dots{})} module name space is
5012 automatically scanned for packages by the command-line tools. For
5013 instance, when running @code{guix install emacs}, all the @code{(gnu
5014 packages @dots{})} modules are scanned until one that exports a package
5015 object whose name is @code{emacs} is found. This package search
5016 facility is implemented in the @code{(gnu packages)} module.
5018 @cindex customization, of packages
5019 @cindex package module search path
5020 Users can store package definitions in modules with different
5021 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5022 name and module name must match. For instance, the @code{(my-packages
5023 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5024 relative to the load path specified with @option{--load-path} or
5025 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5026 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5027 these package definitions visible to the user interfaces:
5031 By adding the directory containing your package modules to the search path
5032 with the @code{-L} flag of @command{guix package} and other commands
5033 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
5034 environment variable described below.
5037 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5038 pulls from it. A channel is essentially a Git repository containing package
5039 modules. @xref{Channels}, for more information on how to define and use
5043 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5045 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5046 This is a colon-separated list of directories to search for additional
5047 package modules. Directories listed in this variable take precedence
5048 over the own modules of the distribution.
5051 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5052 each package is built based solely on other packages in the
5053 distribution. The root of this dependency graph is a small set of
5054 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5055 bootstrap)} module. For more information on bootstrapping,
5056 @pxref{Bootstrapping}.
5058 @node Defining Packages
5059 @section Defining Packages
5061 The high-level interface to package definitions is implemented in the
5062 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5063 example, the package definition, or @dfn{recipe}, for the GNU Hello
5064 package looks like this:
5067 (define-module (gnu packages hello)
5068 #:use-module (guix packages)
5069 #:use-module (guix download)
5070 #:use-module (guix build-system gnu)
5071 #:use-module (guix licenses)
5072 #:use-module (gnu packages gawk))
5074 (define-public hello
5080 (uri (string-append "mirror://gnu/hello/hello-" version
5084 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5085 (build-system gnu-build-system)
5086 (arguments '(#:configure-flags '("--enable-silent-rules")))
5087 (inputs `(("gawk" ,gawk)))
5088 (synopsis "Hello, GNU world: An example GNU package")
5089 (description "Guess what GNU Hello prints!")
5090 (home-page "https://www.gnu.org/software/hello/")
5095 Without being a Scheme expert, the reader may have guessed the meaning
5096 of the various fields here. This expression binds the variable
5097 @code{hello} to a @code{<package>} object, which is essentially a record
5098 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5099 This package object can be inspected using procedures found in the
5100 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5101 returns---surprise!---@code{"hello"}.
5103 With luck, you may be able to import part or all of the definition of
5104 the package you are interested in from another repository, using the
5105 @code{guix import} command (@pxref{Invoking guix import}).
5107 In the example above, @var{hello} is defined in a module of its own,
5108 @code{(gnu packages hello)}. Technically, this is not strictly
5109 necessary, but it is convenient to do so: all the packages defined in
5110 modules under @code{(gnu packages @dots{})} are automatically known to
5111 the command-line tools (@pxref{Package Modules}).
5113 There are a few points worth noting in the above package definition:
5117 The @code{source} field of the package is an @code{<origin>} object
5118 (@pxref{origin Reference}, for the complete reference).
5119 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5120 meaning that the source is a file to be downloaded over FTP or HTTP.
5122 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5123 the GNU mirrors defined in @code{(guix download)}.
5125 The @code{sha256} field specifies the expected SHA256 hash of the file
5126 being downloaded. It is mandatory, and allows Guix to check the
5127 integrity of the file. The @code{(base32 @dots{})} form introduces the
5128 base32 representation of the hash. You can obtain this information with
5129 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5130 hash} (@pxref{Invoking guix hash}).
5133 When needed, the @code{origin} form can also have a @code{patches} field
5134 listing patches to be applied, and a @code{snippet} field giving a
5135 Scheme expression to modify the source code.
5138 @cindex GNU Build System
5139 The @code{build-system} field specifies the procedure to build the
5140 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5141 represents the familiar GNU Build System, where packages may be
5142 configured, built, and installed with the usual @code{./configure &&
5143 make && make check && make install} command sequence.
5146 The @code{arguments} field specifies options for the build system
5147 (@pxref{Build Systems}). Here it is interpreted by
5148 @var{gnu-build-system} as a request run @file{configure} with the
5149 @code{--enable-silent-rules} flag.
5155 What about these quote (@code{'}) characters? They are Scheme syntax to
5156 introduce a literal list; @code{'} is synonymous with @code{quote}.
5157 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5158 for details. Here the value of the @code{arguments} field is a list of
5159 arguments passed to the build system down the road, as with @code{apply}
5160 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5163 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5164 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5165 @code{#:configure-flags} is a keyword used to pass a keyword argument
5166 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5170 The @code{inputs} field specifies inputs to the build process---i.e.,
5171 build-time or run-time dependencies of the package. Here, we define an
5172 input called @code{"gawk"} whose value is that of the @var{gawk}
5173 variable; @var{gawk} is itself bound to a @code{<package>} object.
5175 @cindex backquote (quasiquote)
5178 @cindex comma (unquote)
5182 @findex unquote-splicing
5183 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5184 us to introduce a literal list in the @code{inputs} field, while
5185 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5186 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5189 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5190 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5191 of ensuring that they are present (@pxref{Build Systems}).
5193 However, any other dependencies need to be specified in the
5194 @code{inputs} field. Any dependency not specified here will simply be
5195 unavailable to the build process, possibly leading to a build failure.
5198 @xref{package Reference}, for a full description of possible fields.
5200 Once a package definition is in place, the
5201 package may actually be built using the @code{guix build} command-line
5202 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5203 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5204 package definition using the @command{guix edit} command
5205 (@pxref{Invoking guix edit}).
5206 @xref{Packaging Guidelines}, for
5207 more information on how to test package definitions, and
5208 @ref{Invoking guix lint}, for information on how to check a definition
5209 for style conformance.
5210 @vindex GUIX_PACKAGE_PATH
5211 Lastly, @pxref{Channels}, for information
5212 on how to extend the distribution by adding your own package definitions
5215 Finally, updating the package definition to a new upstream version
5216 can be partly automated by the @command{guix refresh} command
5217 (@pxref{Invoking guix refresh}).
5219 Behind the scenes, a derivation corresponding to the @code{<package>}
5220 object is first computed by the @code{package-derivation} procedure.
5221 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
5222 The build actions it prescribes may then be realized by using the
5223 @code{build-derivations} procedure (@pxref{The Store}).
5225 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5226 Return the @code{<derivation>} object of @var{package} for @var{system}
5227 (@pxref{Derivations}).
5229 @var{package} must be a valid @code{<package>} object, and @var{system}
5230 must be a string denoting the target system type---e.g.,
5231 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5232 must be a connection to the daemon, which operates on the store
5233 (@pxref{The Store}).
5237 @cindex cross-compilation
5238 Similarly, it is possible to compute a derivation that cross-builds a
5239 package for some other system:
5241 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5242 @var{package} @var{target} [@var{system}]
5243 Return the @code{<derivation>} object of @var{package} cross-built from
5244 @var{system} to @var{target}.
5246 @var{target} must be a valid GNU triplet denoting the target hardware
5247 and operating system, such as @code{"mips64el-linux-gnu"}
5248 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
5251 @cindex package transformations
5252 @cindex input rewriting
5253 @cindex dependency tree rewriting
5254 Packages can be manipulated in arbitrary ways. An example of a useful
5255 transformation is @dfn{input rewriting}, whereby the dependency tree of
5256 a package is rewritten by replacing specific inputs by others:
5258 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5259 [@var{rewrite-name}]
5260 Return a procedure that, when passed a package, replaces its direct and
5261 indirect dependencies (but not its implicit inputs) according to
5262 @var{replacements}. @var{replacements} is a list of package pairs; the
5263 first element of each pair is the package to replace, and the second one
5266 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5267 the name of a package and returns its new name after rewrite.
5271 Consider this example:
5274 (define libressl-instead-of-openssl
5275 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5277 (package-input-rewriting `((,openssl . ,libressl))))
5279 (define git-with-libressl
5280 (libressl-instead-of-openssl git))
5284 Here we first define a rewriting procedure that replaces @var{openssl}
5285 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5286 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5287 This is exactly what the @option{--with-input} command-line option does
5288 (@pxref{Package Transformation Options, @option{--with-input}}).
5290 The following variant of @code{package-input-rewriting} can match packages to
5291 be replaced by name rather than by identity.
5293 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5294 Return a procedure that, given a package, applies the given @var{replacements} to
5295 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5296 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5297 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5298 replacement for that package.
5301 The example above could be rewritten this way:
5304 (define libressl-instead-of-openssl
5305 ;; Replace all the packages called "openssl" with LibreSSL.
5306 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5309 The key difference here is that, this time, packages are matched by spec and
5310 not by identity. In other words, any package in the graph that is called
5311 @code{openssl} will be replaced.
5313 A more generic procedure to rewrite a package dependency graph is
5314 @code{package-mapping}: it supports arbitrary changes to nodes in the
5317 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5318 Return a procedure that, given a package, applies @var{proc} to all the packages
5319 depended on and returns the resulting package. The procedure stops recursion
5320 when @var{cut?} returns true for a given package.
5324 * package Reference:: The package data type.
5325 * origin Reference:: The origin data type.
5329 @node package Reference
5330 @subsection @code{package} Reference
5332 This section summarizes all the options available in @code{package}
5333 declarations (@pxref{Defining Packages}).
5335 @deftp {Data Type} package
5336 This is the data type representing a package recipe.
5340 The name of the package, as a string.
5342 @item @code{version}
5343 The version of the package, as a string.
5346 An object telling how the source code for the package should be
5347 acquired. Most of the time, this is an @code{origin} object, which
5348 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5349 can also be any other ``file-like'' object such as a @code{local-file},
5350 which denotes a file from the local file system (@pxref{G-Expressions,
5351 @code{local-file}}).
5353 @item @code{build-system}
5354 The build system that should be used to build the package (@pxref{Build
5357 @item @code{arguments} (default: @code{'()})
5358 The arguments that should be passed to the build system. This is a
5359 list, typically containing sequential keyword-value pairs.
5361 @item @code{inputs} (default: @code{'()})
5362 @itemx @code{native-inputs} (default: @code{'()})
5363 @itemx @code{propagated-inputs} (default: @code{'()})
5364 @cindex inputs, of packages
5365 These fields list dependencies of the package. Each one is a list of
5366 tuples, where each tuple has a label for the input (a string) as its
5367 first element, a package, origin, or derivation as its second element,
5368 and optionally the name of the output thereof that should be used, which
5369 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5370 more on package outputs). For example, the list below specifies three
5374 `(("libffi" ,libffi)
5375 ("libunistring" ,libunistring)
5376 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5379 @cindex cross compilation, package dependencies
5380 The distinction between @code{native-inputs} and @code{inputs} is
5381 necessary when considering cross-compilation. When cross-compiling,
5382 dependencies listed in @code{inputs} are built for the @emph{target}
5383 architecture; conversely, dependencies listed in @code{native-inputs}
5384 are built for the architecture of the @emph{build} machine.
5386 @code{native-inputs} is typically used to list tools needed at
5387 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5388 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5389 this area (@pxref{Invoking guix lint}).
5391 @anchor{package-propagated-inputs}
5392 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5393 specified packages will be automatically installed alongside the package
5394 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5395 package}}, for information on how @command{guix package} deals with
5398 For example this is necessary when a C/C++ library needs headers of
5399 another library to compile, or when a pkg-config file refers to another
5400 one @i{via} its @code{Requires} field.
5402 Another example where @code{propagated-inputs} is useful is for languages
5403 that lack a facility to record the run-time search path akin to the
5404 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5405 more. To ensure that libraries written in those languages can find
5406 library code they depend on at run time, run-time dependencies must be
5407 listed in @code{propagated-inputs} rather than @code{inputs}.
5409 @item @code{outputs} (default: @code{'("out")})
5410 The list of output names of the package. @xref{Packages with Multiple
5411 Outputs}, for typical uses of additional outputs.
5413 @item @code{native-search-paths} (default: @code{'()})
5414 @itemx @code{search-paths} (default: @code{'()})
5415 A list of @code{search-path-specification} objects describing
5416 search-path environment variables honored by the package.
5418 @item @code{replacement} (default: @code{#f})
5419 This must be either @code{#f} or a package object that will be used as a
5420 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5423 @item @code{synopsis}
5424 A one-line description of the package.
5426 @item @code{description}
5427 A more elaborate description of the package.
5429 @item @code{license}
5430 @cindex license, of packages
5431 The license of the package; a value from @code{(guix licenses)},
5432 or a list of such values.
5434 @item @code{home-page}
5435 The URL to the home-page of the package, as a string.
5437 @item @code{supported-systems} (default: @var{%supported-systems})
5438 The list of systems supported by the package, as strings of the form
5439 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5441 @item @code{maintainers} (default: @code{'()})
5442 The list of maintainers of the package, as @code{maintainer} objects.
5444 @item @code{location} (default: source location of the @code{package} form)
5445 The source location of the package. It is useful to override this when
5446 inheriting from another package, in which case this field is not
5447 automatically corrected.
5451 @deffn {Scheme Syntax} this-package
5452 When used in the @emph{lexical scope} of a package field definition, this
5453 identifier resolves to the package being defined.
5455 The example below shows how to add a package as a native input of itself when
5463 ;; When cross-compiled, Guile, for example, depends on
5464 ;; a native version of itself. Add it here.
5465 (native-inputs (if (%current-target-system)
5466 `(("self" ,this-package))
5470 It is an error to refer to @code{this-package} outside a package definition.
5473 @node origin Reference
5474 @subsection @code{origin} Reference
5476 This section summarizes all the options available in @code{origin}
5477 declarations (@pxref{Defining Packages}).
5479 @deftp {Data Type} origin
5480 This is the data type representing a source code origin.
5484 An object containing the URI of the source. The object type depends on
5485 the @code{method} (see below). For example, when using the
5486 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5487 values are: a URL represented as a string, or a list thereof.
5490 A procedure that handles the URI.
5495 @item @var{url-fetch} from @code{(guix download)}
5496 download a file from the HTTP, HTTPS, or FTP URL specified in the
5500 @item @var{git-fetch} from @code{(guix git-download)}
5501 clone the Git version control repository, and check out the revision
5502 specified in the @code{uri} field as a @code{git-reference} object; a
5503 @code{git-reference} looks like this:
5507 (url "git://git.debian.org/git/pkg-shadow/shadow")
5508 (commit "v4.1.5.1"))
5513 A bytevector containing the SHA-256 hash of the source. Typically the
5514 @code{base32} form is used here to generate the bytevector from a
5517 You can obtain this information using @code{guix download}
5518 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5521 @item @code{file-name} (default: @code{#f})
5522 The file name under which the source code should be saved. When this is
5523 @code{#f}, a sensible default value will be used in most cases. In case
5524 the source is fetched from a URL, the file name from the URL will be
5525 used. For version control checkouts, it is recommended to provide the
5526 file name explicitly because the default is not very descriptive.
5528 @item @code{patches} (default: @code{'()})
5529 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5530 file-like objects}) pointing to patches to be applied to the source.
5532 This list of patches must be unconditional. In particular, it cannot
5533 depend on the value of @code{%current-system} or
5534 @code{%current-target-system}.
5536 @item @code{snippet} (default: @code{#f})
5537 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5538 in the source directory. This is a convenient way to modify the source,
5539 sometimes more convenient than a patch.
5541 @item @code{patch-flags} (default: @code{'("-p1")})
5542 A list of command-line flags that should be passed to the @code{patch}
5545 @item @code{patch-inputs} (default: @code{#f})
5546 Input packages or derivations to the patching process. When this is
5547 @code{#f}, the usual set of inputs necessary for patching are provided,
5548 such as GNU@tie{}Patch.
5550 @item @code{modules} (default: @code{'()})
5551 A list of Guile modules that should be loaded during the patching
5552 process and while running the code in the @code{snippet} field.
5554 @item @code{patch-guile} (default: @code{#f})
5555 The Guile package that should be used in the patching process. When
5556 this is @code{#f}, a sensible default is used.
5562 @section Build Systems
5564 @cindex build system
5565 Each package definition specifies a @dfn{build system} and arguments for
5566 that build system (@pxref{Defining Packages}). This @code{build-system}
5567 field represents the build procedure of the package, as well as implicit
5568 dependencies of that build procedure.
5570 Build systems are @code{<build-system>} objects. The interface to
5571 create and manipulate them is provided by the @code{(guix build-system)}
5572 module, and actual build systems are exported by specific modules.
5574 @cindex bag (low-level package representation)
5575 Under the hood, build systems first compile package objects to
5576 @dfn{bags}. A @dfn{bag} is like a package, but with less
5577 ornamentation---in other words, a bag is a lower-level representation of
5578 a package, which includes all the inputs of that package, including some
5579 that were implicitly added by the build system. This intermediate
5580 representation is then compiled to a derivation (@pxref{Derivations}).
5582 Build systems accept an optional list of @dfn{arguments}. In package
5583 definitions, these are passed @i{via} the @code{arguments} field
5584 (@pxref{Defining Packages}). They are typically keyword arguments
5585 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
5586 Guile Reference Manual}). The value of these arguments is usually
5587 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
5588 by the daemon (@pxref{Derivations}).
5590 The main build system is @var{gnu-build-system}, which implements the
5591 standard build procedure for GNU and many other packages. It
5592 is provided by the @code{(guix build-system gnu)} module.
5594 @defvr {Scheme Variable} gnu-build-system
5595 @var{gnu-build-system} represents the GNU Build System, and variants
5596 thereof (@pxref{Configuration, configuration and makefile conventions,,
5597 standards, GNU Coding Standards}).
5599 @cindex build phases
5600 In a nutshell, packages using it are configured, built, and installed with
5601 the usual @code{./configure && make && make check && make install}
5602 command sequence. In practice, a few additional steps are often needed.
5603 All these steps are split up in separate @dfn{phases},
5604 notably@footnote{Please see the @code{(guix build gnu-build-system)}
5605 modules for more details about the build phases.}:
5609 Unpack the source tarball, and change the current directory to the
5610 extracted source tree. If the source is actually a directory, copy it
5611 to the build tree, and enter that directory.
5613 @item patch-source-shebangs
5614 Patch shebangs encountered in source files so they refer to the right
5615 store file names. For instance, this changes @code{#!/bin/sh} to
5616 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
5619 Run the @file{configure} script with a number of default options, such
5620 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
5621 by the @code{#:configure-flags} argument.
5624 Run @code{make} with the list of flags specified with
5625 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
5626 (the default), build with @code{make -j}.
5629 Run @code{make check}, or some other target specified with
5630 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
5631 @code{#:parallel-tests?} argument is true (the default), run @code{make
5635 Run @code{make install} with the flags listed in @code{#:make-flags}.
5637 @item patch-shebangs
5638 Patch shebangs on the installed executable files.
5641 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
5642 is false), copying them to the @code{debug} output when available
5643 (@pxref{Installing Debugging Files}).
5646 @vindex %standard-phases
5647 The build-side module @code{(guix build gnu-build-system)} defines
5648 @var{%standard-phases} as the default list of build phases.
5649 @var{%standard-phases} is a list of symbol/procedure pairs, where the
5650 procedure implements the actual phase.
5652 The list of phases used for a particular package can be changed with the
5653 @code{#:phases} parameter. For instance, passing:
5656 #:phases (modify-phases %standard-phases (delete 'configure))
5659 means that all the phases described above will be used, except the
5660 @code{configure} phase.
5662 In addition, this build system ensures that the ``standard'' environment
5663 for GNU packages is available. This includes tools such as GCC, libc,
5664 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
5665 build-system gnu)} module for a complete list). We call these the
5666 @dfn{implicit inputs} of a package, because package definitions do not
5667 have to mention them.
5670 Other @code{<build-system>} objects are defined to support other
5671 conventions and tools used by free software packages. They inherit most
5672 of @var{gnu-build-system}, and differ mainly in the set of inputs
5673 implicitly added to the build process, and in the list of phases
5674 executed. Some of these build systems are listed below.
5676 @defvr {Scheme Variable} ant-build-system
5677 This variable is exported by @code{(guix build-system ant)}. It
5678 implements the build procedure for Java packages that can be built with
5679 @url{https://ant.apache.org/, Ant build tool}.
5681 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
5682 provided by the @code{icedtea} package to the set of inputs. Different
5683 packages can be specified with the @code{#:ant} and @code{#:jdk}
5684 parameters, respectively.
5686 When the original package does not provide a suitable Ant build file,
5687 the parameter @code{#:jar-name} can be used to generate a minimal Ant
5688 build file @file{build.xml} with tasks to build the specified jar
5689 archive. In this case the parameter @code{#:source-dir} can be used to
5690 specify the source sub-directory, defaulting to ``src''.
5692 The @code{#:main-class} parameter can be used with the minimal ant
5693 buildfile to specify the main class of the resulting jar. This makes the
5694 jar file executable. The @code{#:test-include} parameter can be used to
5695 specify the list of junit tests to run. It defaults to
5696 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
5697 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
5698 because abstract classes cannot be run as tests.
5700 The parameter @code{#:build-target} can be used to specify the Ant task
5701 that should be run during the @code{build} phase. By default the
5702 ``jar'' task will be run.
5706 @defvr {Scheme Variable} android-ndk-build-system
5707 @cindex Android distribution
5708 @cindex Android NDK build system
5709 This variable is exported by @code{(guix build-system android-ndk)}. It
5710 implements a build procedure for Android NDK (native development kit)
5711 packages using a Guix-specific build process.
5713 The build system assumes that packages install their public interface
5714 (header) files to the subdirectory "include" of the "out" output and
5715 their libraries to the subdirectory "lib" of the "out" output.
5717 It's also assumed that the union of all the dependencies of a package
5718 has no conflicting files.
5720 For the time being, cross-compilation is not supported - so right now
5721 the libraries and header files are assumed to be host tools.
5725 @defvr {Scheme Variable} asdf-build-system/source
5726 @defvrx {Scheme Variable} asdf-build-system/sbcl
5727 @defvrx {Scheme Variable} asdf-build-system/ecl
5729 These variables, exported by @code{(guix build-system asdf)}, implement
5730 build procedures for Common Lisp packages using
5731 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
5732 definition facility for Common Lisp programs and libraries.
5734 The @code{asdf-build-system/source} system installs the packages in
5735 source form, and can be loaded using any common lisp implementation, via
5736 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
5737 systems in the format which a particular implementation understands.
5738 These build systems can also be used to produce executable programs, or
5739 lisp images which contain a set of packages pre-loaded.
5741 The build system uses naming conventions. For binary packages, the
5742 package name should be prefixed with the lisp implementation, such as
5743 @code{sbcl-} for @code{asdf-build-system/sbcl}.
5745 Additionally, the corresponding source package should be labeled using
5746 the same convention as python packages (see @ref{Python Modules}), using
5747 the @code{cl-} prefix.
5749 For binary packages, each system should be defined as a Guix package.
5750 If one package @code{origin} contains several systems, package variants
5751 can be created in order to build all the systems. Source packages,
5752 which use @code{asdf-build-system/source}, may contain several systems.
5754 In order to create executable programs and images, the build-side
5755 procedures @code{build-program} and @code{build-image} can be used.
5756 They should be called in a build phase after the @code{create-symlinks}
5757 phase, so that the system which was just built can be used within the
5758 resulting image. @code{build-program} requires a list of Common Lisp
5759 expressions to be passed as the @code{#:entry-program} argument.
5761 If the system is not defined within its own @code{.asd} file of the same
5762 name, then the @code{#:asd-file} parameter should be used to specify
5763 which file the system is defined in. Furthermore, if the package
5764 defines a system for its tests in a separate file, it will be loaded
5765 before the tests are run if it is specified by the
5766 @code{#:test-asd-file} parameter. If it is not set, the files
5767 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
5768 and @code{test.asd} will be tried if they exist.
5770 If for some reason the package must be named in a different way than the
5771 naming conventions suggest, the @code{#:asd-system-name} parameter can
5772 be used to specify the name of the system.
5776 @defvr {Scheme Variable} cargo-build-system
5777 @cindex Rust programming language
5778 @cindex Cargo (Rust build system)
5779 This variable is exported by @code{(guix build-system cargo)}. It
5780 supports builds of packages using Cargo, the build tool of the
5781 @uref{https://www.rust-lang.org, Rust programming language}.
5783 In its @code{configure} phase, this build system replaces dependencies
5784 specified in the @file{Cargo.toml} file with inputs to the Guix package.
5785 The @code{install} phase installs the binaries, and it also installs the
5786 source code and @file{Cargo.toml} file.
5789 @cindex Clojure (programming language)
5790 @cindex simple Clojure build system
5791 @defvr {Scheme Variable} clojure-build-system
5792 This variable is exported by @code{(guix build-system clojure)}. It implements
5793 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
5794 using plain old @code{compile} in Clojure. Cross-compilation is not supported
5797 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
5798 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
5799 @code{#:zip} parameters, respectively.
5801 A list of source directories, test directories and jar names can be specified
5802 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
5803 parameters, respectively. Compile directory and main class can be specified
5804 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
5805 Other parameters are documented below.
5807 This build system is an extension of @var{ant-build-system}, but with the
5808 following phases changed:
5813 This phase calls @code{compile} in Clojure to compile source files and runs
5814 @command{jar} to create jars from both source files and compiled files
5815 according to the include list and exclude list specified in
5816 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
5817 has priority over the include list. These lists consist of symbols
5818 representing Clojure libraries or the special keyword @code{#:all} representing
5819 all Clojure libraries found under the source directories. The parameter
5820 @code{#:omit-source?} decides if source should be included into the jars.
5823 This phase runs tests according to the include list and exclude list specified
5824 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
5825 meanings are analogous to that of @code{#:aot-include} and
5826 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
5827 stands for all Clojure libraries found under the test directories. The
5828 parameter @code{#:tests?} decides if tests should be run.
5831 This phase installs all jars built previously.
5834 Apart from the above, this build system also contains an additional phase:
5839 This phase installs all top-level files with base name matching
5840 @var{%doc-regex}. A different regex can be specified with the
5841 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
5842 directories specified in @code{#:doc-dirs} are installed as well.
5846 @defvr {Scheme Variable} cmake-build-system
5847 This variable is exported by @code{(guix build-system cmake)}. It
5848 implements the build procedure for packages using the
5849 @url{https://www.cmake.org, CMake build tool}.
5851 It automatically adds the @code{cmake} package to the set of inputs.
5852 Which package is used can be specified with the @code{#:cmake}
5855 The @code{#:configure-flags} parameter is taken as a list of flags
5856 passed to the @command{cmake} command. The @code{#:build-type}
5857 parameter specifies in abstract terms the flags passed to the compiler;
5858 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
5859 debugging information''), which roughly means that code is compiled with
5860 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
5863 @defvr {Scheme Variable} dune-build-system
5864 This variable is exported by @code{(guix build-system dune)}. It
5865 supports builds of packages using @uref{https://dune.build/, Dune}, a build
5866 tool for the OCaml programming language. It is implemented as an extension
5867 of the @code{ocaml-build-system} which is described below. As such, the
5868 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
5871 It automatically adds the @code{dune} package to the set of inputs.
5872 Which package is used can be specified with the @code{#:dune}
5875 There is no @code{configure} phase because dune packages typically don't
5876 need to be configured. The @code{#:build-flags} parameter is taken as a
5877 list of flags passed to the @code{dune} command during the build.
5879 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
5880 command instead of the more recent @code{dune} command while building
5881 a package. Its default value is @code{#f}.
5883 The @code{#:package} parameter can be passed to specify a package name, which
5884 is useful when a package contains multiple packages and you want to build
5885 only one of them. This is equivalent to passing the @code{-p} argument to
5889 @defvr {Scheme Variable} go-build-system
5890 This variable is exported by @code{(guix build-system go)}. It
5891 implements a build procedure for Go packages using the standard
5892 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
5893 Go build mechanisms}.
5895 The user is expected to provide a value for the key @code{#:import-path}
5896 and, in some cases, @code{#:unpack-path}. The
5897 @url{https://golang.org/doc/code.html#ImportPaths, import path}
5898 corresponds to the file system path expected by the package's build
5899 scripts and any referring packages, and provides a unique way to
5900 refer to a Go package. It is typically based on a combination of the
5901 package source code's remote URI and file system hierarchy structure. In
5902 some cases, you will need to unpack the package's source code to a
5903 different directory structure than the one indicated by the import path,
5904 and @code{#:unpack-path} should be used in such cases.
5906 Packages that provide Go libraries should install their source code into
5907 the built output. The key @code{#:install-source?}, which defaults to
5908 @code{#t}, controls whether or not the source code is installed. It can
5909 be set to @code{#f} for packages that only provide executable files.
5912 @defvr {Scheme Variable} glib-or-gtk-build-system
5913 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
5914 is intended for use with packages making use of GLib or GTK+.
5916 This build system adds the following two phases to the ones defined by
5917 @var{gnu-build-system}:
5920 @item glib-or-gtk-wrap
5921 The phase @code{glib-or-gtk-wrap} ensures that programs in
5922 @file{bin/} are able to find GLib ``schemas'' and
5923 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
5924 modules}. This is achieved by wrapping the programs in launch scripts
5925 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
5926 environment variables.
5928 It is possible to exclude specific package outputs from that wrapping
5929 process by listing their names in the
5930 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
5931 when an output is known not to contain any GLib or GTK+ binaries, and
5932 where wrapping would gratuitously add a dependency of that output on
5935 @item glib-or-gtk-compile-schemas
5936 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
5937 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
5938 GSettings schemas} of GLib are compiled. Compilation is performed by the
5939 @command{glib-compile-schemas} program. It is provided by the package
5940 @code{glib:bin} which is automatically imported by the build system.
5941 The @code{glib} package providing @command{glib-compile-schemas} can be
5942 specified with the @code{#:glib} parameter.
5945 Both phases are executed after the @code{install} phase.
5948 @defvr {Scheme Variable} guile-build-system
5949 This build system is for Guile packages that consist exclusively of Scheme
5950 code and that are so lean that they don't even have a makefile, let alone a
5951 @file{configure} script. It compiles Scheme code using @command{guild
5952 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
5953 installs the @file{.scm} and @file{.go} files in the right place. It also
5954 installs documentation.
5956 This build system supports cross-compilation by using the @code{--target}
5957 option of @command{guild compile}.
5959 Packages built with @code{guile-build-system} must provide a Guile package in
5960 their @code{native-inputs} field.
5963 @defvr {Scheme Variable} minify-build-system
5964 This variable is exported by @code{(guix build-system minify)}. It
5965 implements a minification procedure for simple JavaScript packages.
5967 It adds @code{uglify-js} to the set of inputs and uses it to compress
5968 all JavaScript files in the @file{src} directory. A different minifier
5969 package can be specified with the @code{#:uglify-js} parameter, but it
5970 is expected that the package writes the minified code to the standard
5973 When the input JavaScript files are not all located in the @file{src}
5974 directory, the parameter @code{#:javascript-files} can be used to
5975 specify a list of file names to feed to the minifier.
5978 @defvr {Scheme Variable} ocaml-build-system
5979 This variable is exported by @code{(guix build-system ocaml)}. It implements
5980 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
5981 of choosing the correct set of commands to run for each package. OCaml
5982 packages can expect many different commands to be run. This build system will
5985 When the package has a @file{setup.ml} file present at the top-level, it will
5986 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
5987 @code{ocaml setup.ml -install}. The build system will assume that this file
5988 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
5989 care of setting the prefix and enabling tests if they are not disabled. You
5990 can pass configure and build flags with the @code{#:configure-flags} and
5991 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
5992 set of flags used to enable tests. The @code{#:use-make?} key can be used to
5993 bypass this system in the build and install phases.
5995 When the package has a @file{configure} file, it is assumed that it is a
5996 hand-made configure script that requires a different argument format than
5997 in the @code{gnu-build-system}. You can add more flags with the
5998 @code{#:configure-flags} key.
6000 When the package has a @file{Makefile} file (or @code{#:use-make?} is
6001 @code{#t}), it will be used and more flags can be passed to the build and
6002 install phases with the @code{#:make-flags} key.
6004 Finally, some packages do not have these files and use a somewhat standard
6005 location for its build system. In that case, the build system will run
6006 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6007 providing the path to the required findlib module. Additional flags can
6008 be passed via the @code{#:build-flags} key. Install is taken care of by
6009 @command{opam-installer}. In this case, the @code{opam} package must
6010 be added to the @code{native-inputs} field of the package definition.
6012 Note that most OCaml packages assume they will be installed in the same
6013 directory as OCaml, which is not what we want in guix. In particular, they
6014 will install @file{.so} files in their module's directory, which is usually
6015 fine because it is in the OCaml compiler directory. In guix though, these
6016 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
6017 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6018 @file{.so} libraries should be installed.
6021 @defvr {Scheme Variable} python-build-system
6022 This variable is exported by @code{(guix build-system python)}. It
6023 implements the more or less standard build procedure used by Python
6024 packages, which consists in running @code{python setup.py build} and
6025 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6027 For packages that install stand-alone Python programs under @code{bin/},
6028 it takes care of wrapping these programs so that their @code{PYTHONPATH}
6029 environment variable points to all the Python libraries they depend on.
6031 Which Python package is used to perform the build can be specified with
6032 the @code{#:python} parameter. This is a useful way to force a package
6033 to be built for a specific version of the Python interpreter, which
6034 might be necessary if the package is only compatible with a single
6035 interpreter version.
6037 By default guix calls @code{setup.py} under control of
6038 @code{setuptools}, much like @command{pip} does. Some packages are not
6039 compatible with setuptools (and pip), thus you can disable this by
6040 setting the @code{#:use-setuptools} parameter to @code{#f}.
6043 @defvr {Scheme Variable} perl-build-system
6044 This variable is exported by @code{(guix build-system perl)}. It
6045 implements the standard build procedure for Perl packages, which either
6046 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6047 followed by @code{Build} and @code{Build install}; or in running
6048 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6049 @code{make} and @code{make install}, depending on which of
6050 @code{Build.PL} or @code{Makefile.PL} is present in the package
6051 distribution. Preference is given to the former if both @code{Build.PL}
6052 and @code{Makefile.PL} exist in the package distribution. This
6053 preference can be reversed by specifying @code{#t} for the
6054 @code{#:make-maker?} parameter.
6056 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6057 passes flags specified by the @code{#:make-maker-flags} or
6058 @code{#:module-build-flags} parameter, respectively.
6060 Which Perl package is used can be specified with @code{#:perl}.
6063 @defvr {Scheme Variable} r-build-system
6064 This variable is exported by @code{(guix build-system r)}. It
6065 implements the build procedure used by @uref{https://r-project.org, R}
6066 packages, which essentially is little more than running @code{R CMD
6067 INSTALL --library=/gnu/store/@dots{}} in an environment where
6068 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6069 are run after installation using the R function
6070 @code{tools::testInstalledPackage}.
6073 @defvr {Scheme Variable} rakudo-build-system
6074 This variable is exported by @code{(guix build-system rakudo)}. It
6075 implements the build procedure used by @uref{https://rakudo.org/,
6076 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6077 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6078 installs the binaries, library files and the resources, as well as wrap
6079 the files under the @code{bin/} directory. Tests can be skipped by
6080 passing @code{#f} to the @code{tests?} parameter.
6082 Which rakudo package is used can be specified with @code{rakudo}.
6083 Which perl6-tap-harness package used for the tests can be specified with
6084 @code{#:prove6} or removed by passing @code{#f} to the
6085 @code{with-prove6?} parameter.
6086 Which perl6-zef package used for tests and installing can be specified
6087 with @code{#:zef} or removed by passing @code{#f} to the
6088 @code{with-zef?} parameter.
6091 @defvr {Scheme Variable} texlive-build-system
6092 This variable is exported by @code{(guix build-system texlive)}. It is
6093 used to build TeX packages in batch mode with a specified engine. The
6094 build system sets the @code{TEXINPUTS} variable to find all TeX source
6095 files in the inputs.
6097 By default it runs @code{luatex} on all files ending on @code{ins}. A
6098 different engine and format can be specified with the
6099 @code{#:tex-format} argument. Different build targets can be specified
6100 with the @code{#:build-targets} argument, which expects a list of file
6101 names. The build system adds only @code{texlive-bin} and
6102 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6103 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6104 and @code{#:texlive-latex-base}, respectively.
6106 The @code{#:tex-directory} parameter tells the build system where to
6107 install the built files under the texmf tree.
6110 @defvr {Scheme Variable} ruby-build-system
6111 This variable is exported by @code{(guix build-system ruby)}. It
6112 implements the RubyGems build procedure used by Ruby packages, which
6113 involves running @code{gem build} followed by @code{gem install}.
6115 The @code{source} field of a package that uses this build system
6116 typically references a gem archive, since this is the format that Ruby
6117 developers use when releasing their software. The build system unpacks
6118 the gem archive, potentially patches the source, runs the test suite,
6119 repackages the gem, and installs it. Additionally, directories and
6120 tarballs may be referenced to allow building unreleased gems from Git or
6121 a traditional source release tarball.
6123 Which Ruby package is used can be specified with the @code{#:ruby}
6124 parameter. A list of additional flags to be passed to the @command{gem}
6125 command can be specified with the @code{#:gem-flags} parameter.
6128 @defvr {Scheme Variable} waf-build-system
6129 This variable is exported by @code{(guix build-system waf)}. It
6130 implements a build procedure around the @code{waf} script. The common
6131 phases---@code{configure}, @code{build}, and @code{install}---are
6132 implemented by passing their names as arguments to the @code{waf}
6135 The @code{waf} script is executed by the Python interpreter. Which
6136 Python package is used to run the script can be specified with the
6137 @code{#:python} parameter.
6140 @defvr {Scheme Variable} scons-build-system
6141 This variable is exported by @code{(guix build-system scons)}. It
6142 implements the build procedure used by the SCons software construction
6143 tool. This build system runs @code{scons} to build the package,
6144 @code{scons test} to run tests, and then @code{scons install} to install
6147 Additional flags to be passed to @code{scons} can be specified with the
6148 @code{#:scons-flags} parameter. The version of Python used to run SCons
6149 can be specified by selecting the appropriate SCons package with the
6150 @code{#:scons} parameter.
6153 @defvr {Scheme Variable} haskell-build-system
6154 This variable is exported by @code{(guix build-system haskell)}. It
6155 implements the Cabal build procedure used by Haskell packages, which
6156 involves running @code{runhaskell Setup.hs configure
6157 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6158 Instead of installing the package by running @code{runhaskell Setup.hs
6159 install}, to avoid trying to register libraries in the read-only
6160 compiler store directory, the build system uses @code{runhaskell
6161 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6162 addition, the build system generates the package documentation by
6163 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6164 is passed. Optional Haddock parameters can be passed with the help of
6165 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6166 not found, the build system looks for @code{Setup.lhs} instead.
6168 Which Haskell compiler is used can be specified with the @code{#:haskell}
6169 parameter which defaults to @code{ghc}.
6172 @defvr {Scheme Variable} dub-build-system
6173 This variable is exported by @code{(guix build-system dub)}. It
6174 implements the Dub build procedure used by D packages, which
6175 involves running @code{dub build} and @code{dub run}.
6176 Installation is done by copying the files manually.
6178 Which D compiler is used can be specified with the @code{#:ldc}
6179 parameter which defaults to @code{ldc}.
6182 @defvr {Scheme Variable} emacs-build-system
6183 This variable is exported by @code{(guix build-system emacs)}. It
6184 implements an installation procedure similar to the packaging system
6185 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6187 It first creates the @code{@var{package}-autoloads.el} file, then it
6188 byte compiles all Emacs Lisp files. Differently from the Emacs
6189 packaging system, the Info documentation files are moved to the standard
6190 documentation directory and the @file{dir} file is deleted. Each
6191 package is installed in its own directory under
6192 @file{share/emacs/site-lisp/guix.d}.
6195 @defvr {Scheme Variable} font-build-system
6196 This variable is exported by @code{(guix build-system font)}. It
6197 implements an installation procedure for font packages where upstream
6198 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6199 need to be copied into place. It copies font files to standard
6200 locations in the output directory.
6203 @defvr {Scheme Variable} meson-build-system
6204 This variable is exported by @code{(guix build-system meson)}. It
6205 implements the build procedure for packages that use
6206 @url{https://mesonbuild.com, Meson} as their build system.
6208 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6209 of inputs, and they can be changed with the parameters @code{#:meson}
6210 and @code{#:ninja} if needed. The default Meson is
6211 @code{meson-for-build}, which is special because it doesn't clear the
6212 @code{RUNPATH} of binaries and libraries when they are installed.
6214 This build system is an extension of @var{gnu-build-system}, but with the
6215 following phases changed to some specific for Meson:
6220 The phase runs @code{meson} with the flags specified in
6221 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6222 @code{plain} unless something else is specified in @code{#:build-type}.
6225 The phase runs @code{ninja} to build the package in parallel by default, but
6226 this can be changed with @code{#:parallel-build?}.
6229 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6230 which is @code{"test"} by default.
6233 The phase runs @code{ninja install} and can not be changed.
6236 Apart from that, the build system also adds the following phases:
6241 This phase ensures that all binaries can find the libraries they need.
6242 It searches for required libraries in subdirectories of the package being
6243 built, and adds those to @code{RUNPATH} where needed. It also removes
6244 references to libraries left over from the build phase by
6245 @code{meson-for-build}, such as test dependencies, that aren't actually
6246 required for the program to run.
6248 @item glib-or-gtk-wrap
6249 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6250 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6252 @item glib-or-gtk-compile-schemas
6253 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6254 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6258 @defvr {Scheme Variable} linux-module-build-system
6259 @var{linux-module-build-system} allows building Linux kernel modules.
6261 @cindex build phases
6262 This build system is an extension of @var{gnu-build-system}, but with the
6263 following phases changed:
6268 This phase configures the environment so that the Linux kernel's Makefile
6269 can be used to build the external kernel module.
6272 This phase uses the Linux kernel's Makefile in order to build the external
6276 This phase uses the Linux kernel's Makefile in order to install the external
6280 It is possible and useful to specify the Linux kernel to use for building
6281 the module (in the "arguments" form of a package using the
6282 linux-module-build-system, use the key #:linux to specify it).
6285 Lastly, for packages that do not need anything as sophisticated, a
6286 ``trivial'' build system is provided. It is trivial in the sense that
6287 it provides basically no support: it does not pull any implicit inputs,
6288 and does not have a notion of build phases.
6290 @defvr {Scheme Variable} trivial-build-system
6291 This variable is exported by @code{(guix build-system trivial)}.
6293 This build system requires a @code{#:builder} argument. This argument
6294 must be a Scheme expression that builds the package output(s)---as
6295 with @code{build-expression->derivation} (@pxref{Derivations,
6296 @code{build-expression->derivation}}).
6306 Conceptually, the @dfn{store} is the place where derivations that have
6307 been built successfully are stored---by default, @file{/gnu/store}.
6308 Sub-directories in the store are referred to as @dfn{store items} or
6309 sometimes @dfn{store paths}. The store has an associated database that
6310 contains information such as the store paths referred to by each store
6311 path, and the list of @emph{valid} store items---results of successful
6312 builds. This database resides in @file{@var{localstatedir}/guix/db},
6313 where @var{localstatedir} is the state directory specified @i{via}
6314 @option{--localstatedir} at configure time, usually @file{/var}.
6316 The store is @emph{always} accessed by the daemon on behalf of its clients
6317 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6318 connect to the daemon over a Unix-domain socket, send requests to it,
6319 and read the result---these are remote procedure calls, or RPCs.
6322 Users must @emph{never} modify files under @file{/gnu/store} directly.
6323 This would lead to inconsistencies and break the immutability
6324 assumptions of Guix's functional model (@pxref{Introduction}).
6326 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6327 how to check the integrity of the store and attempt recovery from
6328 accidental modifications.
6331 The @code{(guix store)} module provides procedures to connect to the
6332 daemon, and to perform RPCs. These are described below. By default,
6333 @code{open-connection}, and thus all the @command{guix} commands,
6334 connect to the local daemon or to the URI specified by the
6335 @code{GUIX_DAEMON_SOCKET} environment variable.
6337 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6338 When set, the value of this variable should be a file name or a URI
6339 designating the daemon endpoint. When it is a file name, it denotes a
6340 Unix-domain socket to connect to. In addition to file names, the
6341 supported URI schemes are:
6346 These are for Unix-domain sockets.
6347 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6348 @file{/var/guix/daemon-socket/socket}.
6351 @cindex daemon, remote access
6352 @cindex remote access to the daemon
6353 @cindex daemon, cluster setup
6354 @cindex clusters, daemon setup
6355 These URIs denote connections over TCP/IP, without encryption nor
6356 authentication of the remote host. The URI must specify the host name
6357 and optionally a port number (by default port 44146 is used):
6360 guix://master.guix.example.org:1234
6363 This setup is suitable on local networks, such as clusters, where only
6364 trusted nodes may connect to the build daemon at
6365 @code{master.guix.example.org}.
6367 The @code{--listen} option of @command{guix-daemon} can be used to
6368 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6372 @cindex SSH access to build daemons
6373 These URIs allow you to connect to a remote daemon over
6374 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
6375 A typical URL might look like this:
6378 ssh://charlie@@guix.example.org:22
6381 As for @command{guix copy}, the usual OpenSSH client configuration files
6382 are honored (@pxref{Invoking guix copy}).
6385 Additional URI schemes may be supported in the future.
6387 @c XXX: Remove this note when the protocol incurs fewer round trips
6388 @c and when (guix derivations) no longer relies on file system access.
6390 The ability to connect to remote build daemons is considered
6391 experimental as of @value{VERSION}. Please get in touch with us to
6392 share any problems or suggestions you may have (@pxref{Contributing}).
6396 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6397 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6398 @var{reserve-space?} is true, instruct it to reserve a little bit of
6399 extra space on the file system so that the garbage collector can still
6400 operate should the disk become full. Return a server object.
6402 @var{file} defaults to @var{%default-socket-path}, which is the normal
6403 location given the options that were passed to @command{configure}.
6406 @deffn {Scheme Procedure} close-connection @var{server}
6407 Close the connection to @var{server}.
6410 @defvr {Scheme Variable} current-build-output-port
6411 This variable is bound to a SRFI-39 parameter, which refers to the port
6412 where build and error logs sent by the daemon should be written.
6415 Procedures that make RPCs all take a server object as their first
6418 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6419 @cindex invalid store items
6420 Return @code{#t} when @var{path} designates a valid store item and
6421 @code{#f} otherwise (an invalid item may exist on disk but still be
6422 invalid, for instance because it is the result of an aborted or failed
6425 A @code{&store-protocol-error} condition is raised if @var{path} is not
6426 prefixed by the store directory (@file{/gnu/store}).
6429 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6430 Add @var{text} under file @var{name} in the store, and return its store
6431 path. @var{references} is the list of store paths referred to by the
6432 resulting store path.
6435 @deffn {Scheme Procedure} build-derivations @var{server} @var{derivations}
6436 Build @var{derivations} (a list of @code{<derivation>} objects or
6437 derivation paths), and return when the worker is done building them.
6438 Return @code{#t} on success.
6441 Note that the @code{(guix monads)} module provides a monad as well as
6442 monadic versions of the above procedures, with the goal of making it
6443 more convenient to work with code that accesses the store (@pxref{The
6447 @i{This section is currently incomplete.}
6450 @section Derivations
6453 Low-level build actions and the environment in which they are performed
6454 are represented by @dfn{derivations}. A derivation contains the
6455 following pieces of information:
6459 The outputs of the derivation---derivations produce at least one file or
6460 directory in the store, but may produce more.
6463 @cindex build-time dependencies
6464 @cindex dependencies, build-time
6465 The inputs of the derivations---i.e., its build-time dependencies---which may
6466 be other derivations or plain files in the store (patches, build scripts,
6470 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
6473 The file name of a build script in the store, along with the arguments
6477 A list of environment variables to be defined.
6481 @cindex derivation path
6482 Derivations allow clients of the daemon to communicate build actions to
6483 the store. They exist in two forms: as an in-memory representation,
6484 both on the client- and daemon-side, and as files in the store whose
6485 name end in @code{.drv}---these files are referred to as @dfn{derivation
6486 paths}. Derivations paths can be passed to the @code{build-derivations}
6487 procedure to perform the build actions they prescribe (@pxref{The
6490 @cindex fixed-output derivations
6491 Operations such as file downloads and version-control checkouts for
6492 which the expected content hash is known in advance are modeled as
6493 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
6494 of a fixed-output derivation are independent of its inputs---e.g., a
6495 source code download produces the same result regardless of the download
6496 method and tools being used.
6499 @cindex run-time dependencies
6500 @cindex dependencies, run-time
6501 The outputs of derivations---i.e., the build results---have a set of
6502 @dfn{references}, as reported by the @code{references} RPC or the
6503 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
6504 are the set of run-time dependencies of the build results. References are a
6505 subset of the inputs of the derivation; this subset is automatically computed
6506 by the build daemon by scanning all the files in the outputs.
6508 The @code{(guix derivations)} module provides a representation of
6509 derivations as Scheme objects, along with procedures to create and
6510 otherwise manipulate derivations. The lowest-level primitive to create
6511 a derivation is the @code{derivation} procedure:
6513 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
6514 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6515 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
6516 [#:system (%current-system)] [#:references-graphs #f] @
6517 [#:allowed-references #f] [#:disallowed-references #f] @
6518 [#:leaked-env-vars #f] [#:local-build? #f] @
6519 [#:substitutable? #t] [#:properties '()]
6520 Build a derivation with the given arguments, and return the resulting
6521 @code{<derivation>} object.
6523 When @var{hash} and @var{hash-algo} are given, a
6524 @dfn{fixed-output derivation} is created---i.e., one whose result is
6525 known in advance, such as a file download. If, in addition,
6526 @var{recursive?} is true, then that fixed output may be an executable
6527 file or a directory and @var{hash} must be the hash of an archive
6528 containing this output.
6530 When @var{references-graphs} is true, it must be a list of file
6531 name/store path pairs. In that case, the reference graph of each store
6532 path is exported in the build environment in the corresponding file, in
6533 a simple text format.
6535 When @var{allowed-references} is true, it must be a list of store items
6536 or outputs that the derivation's output may refer to. Likewise,
6537 @var{disallowed-references}, if true, must be a list of things the
6538 outputs may @emph{not} refer to.
6540 When @var{leaked-env-vars} is true, it must be a list of strings
6541 denoting environment variables that are allowed to ``leak'' from the
6542 daemon's environment to the build environment. This is only applicable
6543 to fixed-output derivations---i.e., when @var{hash} is true. The main
6544 use is to allow variables such as @code{http_proxy} to be passed to
6545 derivations that download files.
6547 When @var{local-build?} is true, declare that the derivation is not a
6548 good candidate for offloading and should rather be built locally
6549 (@pxref{Daemon Offload Setup}). This is the case for small derivations
6550 where the costs of data transfers would outweigh the benefits.
6552 When @var{substitutable?} is false, declare that substitutes of the
6553 derivation's output should not be used (@pxref{Substitutes}). This is
6554 useful, for instance, when building packages that capture details of the
6555 host CPU instruction set.
6557 @var{properties} must be an association list describing ``properties'' of the
6558 derivation. It is kept as-is, uninterpreted, in the derivation.
6562 Here's an example with a shell script as its builder, assuming
6563 @var{store} is an open connection to the daemon, and @var{bash} points
6564 to a Bash executable in the store:
6567 (use-modules (guix utils)
6571 (let ((builder ; add the Bash script to the store
6572 (add-text-to-store store "my-builder.sh"
6573 "echo hello world > $out\n" '())))
6574 (derivation store "foo"
6575 bash `("-e" ,builder)
6576 #:inputs `((,bash) (,builder))
6577 #:env-vars '(("HOME" . "/homeless"))))
6578 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
6581 As can be guessed, this primitive is cumbersome to use directly. A
6582 better approach is to write build scripts in Scheme, of course! The
6583 best course of action for that is to write the build code as a
6584 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
6585 information, @pxref{G-Expressions}.
6587 Once upon a time, @code{gexp->derivation} did not exist and constructing
6588 derivations with build code written in Scheme was achieved with
6589 @code{build-expression->derivation}, documented below. This procedure
6590 is now deprecated in favor of the much nicer @code{gexp->derivation}.
6592 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
6593 @var{name} @var{exp} @
6594 [#:system (%current-system)] [#:inputs '()] @
6595 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6596 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
6597 [#:references-graphs #f] [#:allowed-references #f] @
6598 [#:disallowed-references #f] @
6599 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
6600 Return a derivation that executes Scheme expression @var{exp} as a
6601 builder for derivation @var{name}. @var{inputs} must be a list of
6602 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
6603 @code{"out"} is assumed. @var{modules} is a list of names of Guile
6604 modules from the current search path to be copied in the store,
6605 compiled, and made available in the load path during the execution of
6606 @var{exp}---e.g., @code{((guix build utils) (guix build
6607 gnu-build-system))}.
6609 @var{exp} is evaluated in an environment where @code{%outputs} is bound
6610 to a list of output/path pairs, and where @code{%build-inputs} is bound
6611 to a list of string/output-path pairs made from @var{inputs}.
6612 Optionally, @var{env-vars} is a list of string pairs specifying the name
6613 and value of environment variables visible to the builder. The builder
6614 terminates by passing the result of @var{exp} to @code{exit}; thus, when
6615 @var{exp} returns @code{#f}, the build is considered to have failed.
6617 @var{exp} is built using @var{guile-for-build} (a derivation). When
6618 @var{guile-for-build} is omitted or is @code{#f}, the value of the
6619 @code{%guile-for-build} fluid is used instead.
6621 See the @code{derivation} procedure for the meaning of
6622 @var{references-graphs}, @var{allowed-references},
6623 @var{disallowed-references}, @var{local-build?}, and
6624 @var{substitutable?}.
6628 Here's an example of a single-output derivation that creates a directory
6629 containing one file:
6632 (let ((builder '(let ((out (assoc-ref %outputs "out")))
6633 (mkdir out) ; create /gnu/store/@dots{}-goo
6634 (call-with-output-file (string-append out "/test")
6636 (display '(hello guix) p))))))
6637 (build-expression->derivation store "goo" builder))
6639 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
6643 @node The Store Monad
6644 @section The Store Monad
6648 The procedures that operate on the store described in the previous
6649 sections all take an open connection to the build daemon as their first
6650 argument. Although the underlying model is functional, they either have
6651 side effects or depend on the current state of the store.
6653 The former is inconvenient: the connection to the build daemon has to be
6654 carried around in all those functions, making it impossible to compose
6655 functions that do not take that parameter with functions that do. The
6656 latter can be problematic: since store operations have side effects
6657 and/or depend on external state, they have to be properly sequenced.
6659 @cindex monadic values
6660 @cindex monadic functions
6661 This is where the @code{(guix monads)} module comes in. This module
6662 provides a framework for working with @dfn{monads}, and a particularly
6663 useful monad for our uses, the @dfn{store monad}. Monads are a
6664 construct that allows two things: associating ``context'' with values
6665 (in our case, the context is the store), and building sequences of
6666 computations (here computations include accesses to the store). Values
6667 in a monad---values that carry this additional context---are called
6668 @dfn{monadic values}; procedures that return such values are called
6669 @dfn{monadic procedures}.
6671 Consider this ``normal'' procedure:
6674 (define (sh-symlink store)
6675 ;; Return a derivation that symlinks the 'bash' executable.
6676 (let* ((drv (package-derivation store bash))
6677 (out (derivation->output-path drv))
6678 (sh (string-append out "/bin/bash")))
6679 (build-expression->derivation store "sh"
6680 `(symlink ,sh %output))))
6683 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
6684 as a monadic function:
6687 (define (sh-symlink)
6688 ;; Same, but return a monadic value.
6689 (mlet %store-monad ((drv (package->derivation bash)))
6690 (gexp->derivation "sh"
6691 #~(symlink (string-append #$drv "/bin/bash")
6695 There are several things to note in the second version: the @code{store}
6696 parameter is now implicit and is ``threaded'' in the calls to the
6697 @code{package->derivation} and @code{gexp->derivation} monadic
6698 procedures, and the monadic value returned by @code{package->derivation}
6699 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
6701 As it turns out, the call to @code{package->derivation} can even be
6702 omitted since it will take place implicitly, as we will see later
6703 (@pxref{G-Expressions}):
6706 (define (sh-symlink)
6707 (gexp->derivation "sh"
6708 #~(symlink (string-append #$bash "/bin/bash")
6713 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
6714 @c for the funny quote.
6715 Calling the monadic @code{sh-symlink} has no effect. As someone once
6716 said, ``you exit a monad like you exit a building on fire: by running''.
6717 So, to exit the monad and get the desired effect, one must use
6718 @code{run-with-store}:
6721 (run-with-store (open-connection) (sh-symlink))
6722 @result{} /gnu/store/...-sh-symlink
6725 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
6726 new ``meta-commands'' to make it easier to deal with monadic procedures:
6727 @code{run-in-store}, and @code{enter-store-monad}. The former is used
6728 to ``run'' a single monadic value through the store:
6731 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
6732 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6735 The latter enters a recursive REPL, where all the return values are
6736 automatically run through the store:
6739 scheme@@(guile-user)> ,enter-store-monad
6740 store-monad@@(guile-user) [1]> (package->derivation hello)
6741 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6742 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
6743 $3 = "/gnu/store/@dots{}-foo"
6744 store-monad@@(guile-user) [1]> ,q
6745 scheme@@(guile-user)>
6749 Note that non-monadic values cannot be returned in the
6750 @code{store-monad} REPL.
6752 The main syntactic forms to deal with monads in general are provided by
6753 the @code{(guix monads)} module and are described below.
6755 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
6756 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
6760 @deffn {Scheme Syntax} return @var{val}
6761 Return a monadic value that encapsulates @var{val}.
6764 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
6765 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
6766 procedures @var{mproc}@dots{}@footnote{This operation is commonly
6767 referred to as ``bind'', but that name denotes an unrelated procedure in
6768 Guile. Thus we use this somewhat cryptic symbol inherited from the
6769 Haskell language.}. There can be one @var{mproc} or several of them, as
6774 (with-monad %state-monad
6776 (lambda (x) (return (+ 1 x)))
6777 (lambda (x) (return (* 2 x)))))
6781 @result{} some-state
6785 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
6787 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
6789 Bind the variables @var{var} to the monadic values @var{mval} in
6790 @var{body}, which is a sequence of expressions. As with the bind
6791 operator, this can be thought of as ``unpacking'' the raw, non-monadic
6792 value ``contained'' in @var{mval} and making @var{var} refer to that
6793 raw, non-monadic value within the scope of the @var{body}. The form
6794 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
6795 @var{val}, as per @code{let}. The binding operations occur in sequence
6796 from left to right. The last expression of @var{body} must be a monadic
6797 expression, and its result will become the result of the @code{mlet} or
6798 @code{mlet*} when run in the @var{monad}.
6800 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
6801 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
6804 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
6805 Bind @var{mexp} and the following monadic expressions in sequence,
6806 returning the result of the last expression. Every expression in the
6807 sequence must be a monadic expression.
6809 This is akin to @code{mlet}, except that the return values of the
6810 monadic expressions are ignored. In that sense, it is analogous to
6811 @code{begin}, but applied to monadic expressions.
6814 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
6815 When @var{condition} is true, evaluate the sequence of monadic
6816 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6817 @var{condition} is false, return @code{*unspecified*} in the current
6818 monad. Every expression in the sequence must be a monadic expression.
6821 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
6822 When @var{condition} is false, evaluate the sequence of monadic
6823 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6824 @var{condition} is true, return @code{*unspecified*} in the current
6825 monad. Every expression in the sequence must be a monadic expression.
6829 The @code{(guix monads)} module provides the @dfn{state monad}, which
6830 allows an additional value---the state---to be @emph{threaded} through
6831 monadic procedure calls.
6833 @defvr {Scheme Variable} %state-monad
6834 The state monad. Procedures in the state monad can access and change
6835 the state that is threaded.
6837 Consider the example below. The @code{square} procedure returns a value
6838 in the state monad. It returns the square of its argument, but also
6839 increments the current state value:
6843 (mlet %state-monad ((count (current-state)))
6844 (mbegin %state-monad
6845 (set-current-state (+ 1 count))
6848 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
6853 When ``run'' through @var{%state-monad}, we obtain that additional state
6854 value, which is the number of @code{square} calls.
6857 @deffn {Monadic Procedure} current-state
6858 Return the current state as a monadic value.
6861 @deffn {Monadic Procedure} set-current-state @var{value}
6862 Set the current state to @var{value} and return the previous state as a
6866 @deffn {Monadic Procedure} state-push @var{value}
6867 Push @var{value} to the current state, which is assumed to be a list,
6868 and return the previous state as a monadic value.
6871 @deffn {Monadic Procedure} state-pop
6872 Pop a value from the current state and return it as a monadic value.
6873 The state is assumed to be a list.
6876 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
6877 Run monadic value @var{mval} starting with @var{state} as the initial
6878 state. Return two values: the resulting value, and the resulting state.
6881 The main interface to the store monad, provided by the @code{(guix
6882 store)} module, is as follows.
6884 @defvr {Scheme Variable} %store-monad
6885 The store monad---an alias for @var{%state-monad}.
6887 Values in the store monad encapsulate accesses to the store. When its
6888 effect is needed, a value of the store monad must be ``evaluated'' by
6889 passing it to the @code{run-with-store} procedure (see below.)
6892 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
6893 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
6894 open store connection.
6897 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
6898 Return as a monadic value the absolute file name in the store of the file
6899 containing @var{text}, a string. @var{references} is a list of store items that the
6900 resulting text file refers to; it defaults to the empty list.
6903 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
6904 Return as a monadic value the absolute file name in the store of the file
6905 containing @var{data}, a bytevector. @var{references} is a list of store
6906 items that the resulting binary file refers to; it defaults to the empty list.
6909 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
6910 [#:recursive? #t] [#:select? (const #t)]
6911 Return the name of @var{file} once interned in the store. Use
6912 @var{name} as its store name, or the basename of @var{file} if
6913 @var{name} is omitted.
6915 When @var{recursive?} is true, the contents of @var{file} are added
6916 recursively; if @var{file} designates a flat file and @var{recursive?}
6917 is true, its contents are added, and its permission bits are kept.
6919 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
6920 @var{stat})} for each directory entry, where @var{file} is the entry's
6921 absolute file name and @var{stat} is the result of @code{lstat}; exclude
6922 entries for which @var{select?} does not return true.
6924 The example below adds a file to the store, under two different names:
6927 (run-with-store (open-connection)
6928 (mlet %store-monad ((a (interned-file "README"))
6929 (b (interned-file "README" "LEGU-MIN")))
6930 (return (list a b))))
6932 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
6937 The @code{(guix packages)} module exports the following package-related
6940 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
6941 [#:system (%current-system)] [#:target #f] @
6944 value in the absolute file name of @var{file} within the @var{output}
6945 directory of @var{package}. When @var{file} is omitted, return the name
6946 of the @var{output} directory of @var{package}. When @var{target} is
6947 true, use it as a cross-compilation target triplet.
6950 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
6951 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
6952 @var{target} [@var{system}]
6953 Monadic version of @code{package-derivation} and
6954 @code{package-cross-derivation} (@pxref{Defining Packages}).
6959 @section G-Expressions
6961 @cindex G-expression
6962 @cindex build code quoting
6963 So we have ``derivations'', which represent a sequence of build actions
6964 to be performed to produce an item in the store (@pxref{Derivations}).
6965 These build actions are performed when asking the daemon to actually
6966 build the derivations; they are run by the daemon in a container
6967 (@pxref{Invoking guix-daemon}).
6969 @cindex strata of code
6970 It should come as no surprise that we like to write these build actions
6971 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
6972 code@footnote{The term @dfn{stratum} in this context was coined by
6973 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
6974 Kiselyov, who has written insightful
6975 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
6976 on this topic}, refers to this kind of code generation as
6977 @dfn{staging}.}: the ``host code''---code that defines packages, talks
6978 to the daemon, etc.---and the ``build code''---code that actually
6979 performs build actions, such as making directories, invoking
6980 @command{make}, etc.
6982 To describe a derivation and its build actions, one typically needs to
6983 embed build code inside host code. It boils down to manipulating build
6984 code as data, and the homoiconicity of Scheme---code has a direct
6985 representation as data---comes in handy for that. But we need more than
6986 the normal @code{quasiquote} mechanism in Scheme to construct build
6989 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
6990 S-expressions adapted to build expressions. G-expressions, or
6991 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
6992 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
6993 @code{#$}, and @code{#$@@}), which are comparable to
6994 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
6995 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
6996 GNU Guile Reference Manual}). However, there are major differences:
7000 Gexps are meant to be written to a file and run or manipulated by other
7004 When a high-level object such as a package or derivation is unquoted
7005 inside a gexp, the result is as if its output file name had been
7009 Gexps carry information about the packages or derivations they refer to,
7010 and these dependencies are automatically added as inputs to the build
7011 processes that use them.
7014 @cindex lowering, of high-level objects in gexps
7015 This mechanism is not limited to package and derivation
7016 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7017 derivations or files in the store can be defined,
7018 such that these objects can also be inserted
7019 into gexps. For example, a useful type of high-level objects that can be
7020 inserted in a gexp is ``file-like objects'', which make it easy to
7021 add files to the store and to refer to them in
7022 derivations and such (see @code{local-file} and @code{plain-file}
7025 To illustrate the idea, here is an example of a gexp:
7032 (symlink (string-append #$coreutils "/bin/ls")
7036 This gexp can be passed to @code{gexp->derivation}; we obtain a
7037 derivation that builds a directory containing exactly one symlink to
7038 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7041 (gexp->derivation "the-thing" build-exp)
7044 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7045 substituted to the reference to the @var{coreutils} package in the
7046 actual build code, and @var{coreutils} is automatically made an input to
7047 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7048 output)}) is replaced by a string containing the directory name of the
7049 output of the derivation.
7051 @cindex cross compilation
7052 In a cross-compilation context, it is useful to distinguish between
7053 references to the @emph{native} build of a package---that can run on the
7054 host---versus references to cross builds of a package. To that end, the
7055 @code{#+} plays the same role as @code{#$}, but is a reference to a
7056 native package build:
7059 (gexp->derivation "vi"
7062 (system* (string-append #+coreutils "/bin/ln")
7064 (string-append #$emacs "/bin/emacs")
7065 (string-append #$output "/bin/vi")))
7066 #:target "mips64el-linux-gnu")
7070 In the example above, the native build of @var{coreutils} is used, so
7071 that @command{ln} can actually run on the host; but then the
7072 cross-compiled build of @var{emacs} is referenced.
7074 @cindex imported modules, for gexps
7075 @findex with-imported-modules
7076 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7077 able to use certain Guile modules from the ``host environment'' in the
7078 gexp, so those modules should be imported in the ``build environment''.
7079 The @code{with-imported-modules} form allows you to express that:
7082 (let ((build (with-imported-modules '((guix build utils))
7084 (use-modules (guix build utils))
7085 (mkdir-p (string-append #$output "/bin"))))))
7086 (gexp->derivation "empty-dir"
7089 (display "success!\n")
7094 In this example, the @code{(guix build utils)} module is automatically
7095 pulled into the isolated build environment of our gexp, such that
7096 @code{(use-modules (guix build utils))} works as expected.
7098 @cindex module closure
7099 @findex source-module-closure
7100 Usually you want the @emph{closure} of the module to be imported---i.e.,
7101 the module itself and all the modules it depends on---rather than just
7102 the module; failing to do that, attempts to use the module will fail
7103 because of missing dependent modules. The @code{source-module-closure}
7104 procedure computes the closure of a module by looking at its source file
7105 headers, which comes in handy in this case:
7108 (use-modules (guix modules)) ;for 'source-module-closure'
7110 (with-imported-modules (source-module-closure
7111 '((guix build utils)
7113 (gexp->derivation "something-with-vms"
7115 (use-modules (guix build utils)
7120 @cindex extensions, for gexps
7121 @findex with-extensions
7122 In the same vein, sometimes you want to import not just pure-Scheme
7123 modules, but also ``extensions'' such as Guile bindings to C libraries
7124 or other ``full-blown'' packages. Say you need the @code{guile-json}
7125 package available on the build side, here's how you would do it:
7128 (use-modules (gnu packages guile)) ;for 'guile-json'
7130 (with-extensions (list guile-json)
7131 (gexp->derivation "something-with-json"
7133 (use-modules (json))
7137 The syntactic form to construct gexps is summarized below.
7139 @deffn {Scheme Syntax} #~@var{exp}
7140 @deffnx {Scheme Syntax} (gexp @var{exp})
7141 Return a G-expression containing @var{exp}. @var{exp} may contain one
7142 or more of the following forms:
7146 @itemx (ungexp @var{obj})
7147 Introduce a reference to @var{obj}. @var{obj} may have one of the
7148 supported types, for example a package or a
7149 derivation, in which case the @code{ungexp} form is replaced by its
7150 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7152 If @var{obj} is a list, it is traversed and references to supported
7153 objects are substituted similarly.
7155 If @var{obj} is another gexp, its contents are inserted and its
7156 dependencies are added to those of the containing gexp.
7158 If @var{obj} is another kind of object, it is inserted as is.
7160 @item #$@var{obj}:@var{output}
7161 @itemx (ungexp @var{obj} @var{output})
7162 This is like the form above, but referring explicitly to the
7163 @var{output} of @var{obj}---this is useful when @var{obj} produces
7164 multiple outputs (@pxref{Packages with Multiple Outputs}).
7167 @itemx #+@var{obj}:output
7168 @itemx (ungexp-native @var{obj})
7169 @itemx (ungexp-native @var{obj} @var{output})
7170 Same as @code{ungexp}, but produces a reference to the @emph{native}
7171 build of @var{obj} when used in a cross compilation context.
7173 @item #$output[:@var{output}]
7174 @itemx (ungexp output [@var{output}])
7175 Insert a reference to derivation output @var{output}, or to the main
7176 output when @var{output} is omitted.
7178 This only makes sense for gexps passed to @code{gexp->derivation}.
7181 @itemx (ungexp-splicing @var{lst})
7182 Like the above, but splices the contents of @var{lst} inside the
7186 @itemx (ungexp-native-splicing @var{lst})
7187 Like the above, but refers to native builds of the objects listed in
7192 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7193 of the @code{gexp?} type (see below.)
7196 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7197 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7198 in their execution environment.
7200 Each item in @var{modules} can be the name of a module, such as
7201 @code{(guix build utils)}, or it can be a module name, followed by an
7202 arrow, followed by a file-like object:
7205 `((guix build utils)
7207 ((guix config) => ,(scheme-file "config.scm"
7208 #~(define-module @dots{}))))
7212 In the example above, the first two modules are taken from the search
7213 path, and the last one is created from the given file-like object.
7215 This form has @emph{lexical} scope: it has an effect on the gexps
7216 directly defined in @var{body}@dots{}, but not on those defined, say, in
7217 procedures called from @var{body}@dots{}.
7220 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7221 Mark the gexps defined in @var{body}@dots{} as requiring
7222 @var{extensions} in their build and execution environment.
7223 @var{extensions} is typically a list of package objects such as those
7224 defined in the @code{(gnu packages guile)} module.
7226 Concretely, the packages listed in @var{extensions} are added to the
7227 load path while compiling imported modules in @var{body}@dots{}; they
7228 are also added to the load path of the gexp returned by
7232 @deffn {Scheme Procedure} gexp? @var{obj}
7233 Return @code{#t} if @var{obj} is a G-expression.
7236 G-expressions are meant to be written to disk, either as code building
7237 some derivation, or as plain files in the store. The monadic procedures
7238 below allow you to do that (@pxref{The Store Monad}, for more
7239 information about monads.)
7241 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7242 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7243 [#:hash #f] [#:hash-algo #f] @
7244 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7245 [#:module-path @var{%load-path}] @
7246 [#:effective-version "2.2"] @
7247 [#:references-graphs #f] [#:allowed-references #f] @
7248 [#:disallowed-references #f] @
7249 [#:leaked-env-vars #f] @
7250 [#:script-name (string-append @var{name} "-builder")] @
7251 [#:deprecation-warnings #f] @
7252 [#:local-build? #f] [#:substitutable? #t] @
7253 [#:properties '()] [#:guile-for-build #f]
7254 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7255 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7256 stored in a file called @var{script-name}. When @var{target} is true,
7257 it is used as the cross-compilation target triplet for packages referred
7260 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7262 make @var{modules} available in the evaluation context of @var{exp};
7263 @var{modules} is a list of names of Guile modules searched in
7264 @var{module-path} to be copied in the store, compiled, and made available in
7265 the load path during the execution of @var{exp}---e.g., @code{((guix
7266 build utils) (guix build gnu-build-system))}.
7268 @var{effective-version} determines the string to use when adding extensions of
7269 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7271 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7274 When @var{references-graphs} is true, it must be a list of tuples of one of the
7278 (@var{file-name} @var{package})
7279 (@var{file-name} @var{package} @var{output})
7280 (@var{file-name} @var{derivation})
7281 (@var{file-name} @var{derivation} @var{output})
7282 (@var{file-name} @var{store-item})
7285 The right-hand-side of each element of @var{references-graphs} is automatically made
7286 an input of the build process of @var{exp}. In the build environment, each
7287 @var{file-name} contains the reference graph of the corresponding item, in a simple
7290 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7291 In the latter case, the list denotes store items that the result is allowed to
7292 refer to. Any reference to another store item will lead to a build error.
7293 Similarly for @var{disallowed-references}, which can list items that must not be
7294 referenced by the outputs.
7296 @var{deprecation-warnings} determines whether to show deprecation warnings while
7297 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7299 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7302 @cindex file-like objects
7303 The @code{local-file}, @code{plain-file}, @code{computed-file},
7304 @code{program-file}, and @code{scheme-file} procedures below return
7305 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7306 these objects lead to a file in the store. Consider this G-expression:
7309 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7310 #$(local-file "/tmp/my-nscd.conf"))
7313 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7314 to the store. Once expanded, for instance @i{via}
7315 @code{gexp->derivation}, the G-expression refers to that copy under
7316 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7317 does not have any effect on what the G-expression does.
7318 @code{plain-file} can be used similarly; it differs in that the file
7319 content is directly passed as a string.
7321 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7322 [#:recursive? #f] [#:select? (const #t)]
7323 Return an object representing local file @var{file} to add to the store; this
7324 object can be used in a gexp. If @var{file} is a relative file name, it is looked
7325 up relative to the source file where this form appears. @var{file} will be added to
7326 the store under @var{name}--by default the base name of @var{file}.
7328 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7329 designates a flat file and @var{recursive?} is true, its contents are added, and its
7330 permission bits are kept.
7332 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7333 @var{stat})} for each directory entry, where @var{file} is the entry's
7334 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7335 entries for which @var{select?} does not return true.
7337 This is the declarative counterpart of the @code{interned-file} monadic
7338 procedure (@pxref{The Store Monad, @code{interned-file}}).
7341 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7342 Return an object representing a text file called @var{name} with the given
7343 @var{content} (a string or a bytevector) to be added to the store.
7345 This is the declarative counterpart of @code{text-file}.
7348 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7349 [#:options '(#:local-build? #t)]
7350 Return an object representing the store item @var{name}, a file or
7351 directory computed by @var{gexp}. @var{options}
7352 is a list of additional arguments to pass to @code{gexp->derivation}.
7354 This is the declarative counterpart of @code{gexp->derivation}.
7357 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7358 [#:guile (default-guile)] [#:module-path %load-path]
7359 Return an executable script @var{name} that runs @var{exp} using
7360 @var{guile}, with @var{exp}'s imported modules in its search path.
7361 Look up @var{exp}'s modules in @var{module-path}.
7363 The example below builds a script that simply invokes the @command{ls}
7367 (use-modules (guix gexp) (gnu packages base))
7369 (gexp->script "list-files"
7370 #~(execl #$(file-append coreutils "/bin/ls")
7374 When ``running'' it through the store (@pxref{The Store Monad,
7375 @code{run-with-store}}), we obtain a derivation that produces an
7376 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7379 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7381 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7385 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7386 [#:guile #f] [#:module-path %load-path]
7387 Return an object representing the executable store item @var{name} that
7388 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7389 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7391 This is the declarative counterpart of @code{gexp->script}.
7394 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7395 [#:set-load-path? #t] [#:module-path %load-path] @
7397 [#:guile (default-guile)]
7398 Return a derivation that builds a file @var{name} containing @var{exp}.
7399 When @var{splice?} is true, @var{exp} is considered to be a list of
7400 expressions that will be spliced in the resulting file.
7402 When @var{set-load-path?} is true, emit code in the resulting file to
7403 set @code{%load-path} and @code{%load-compiled-path} to honor
7404 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7407 The resulting file holds references to all the dependencies of @var{exp}
7408 or a subset thereof.
7411 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
7412 Return an object representing the Scheme file @var{name} that contains
7415 This is the declarative counterpart of @code{gexp->file}.
7418 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7419 Return as a monadic value a derivation that builds a text file
7420 containing all of @var{text}. @var{text} may list, in addition to
7421 strings, objects of any type that can be used in a gexp: packages,
7422 derivations, local file objects, etc. The resulting store file holds
7423 references to all these.
7425 This variant should be preferred over @code{text-file} anytime the file
7426 to create will reference items from the store. This is typically the
7427 case when building a configuration file that embeds store file names,
7431 (define (profile.sh)
7432 ;; Return the name of a shell script in the store that
7433 ;; initializes the 'PATH' environment variable.
7434 (text-file* "profile.sh"
7435 "export PATH=" coreutils "/bin:"
7436 grep "/bin:" sed "/bin\n"))
7439 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
7440 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
7441 preventing them from being garbage-collected during its lifetime.
7444 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
7445 Return an object representing store file @var{name} containing
7446 @var{text}. @var{text} is a sequence of strings and file-like objects,
7450 (mixed-text-file "profile"
7451 "export PATH=" coreutils "/bin:" grep "/bin")
7454 This is the declarative counterpart of @code{text-file*}.
7457 @deffn {Scheme Procedure} file-union @var{name} @var{files}
7458 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
7459 Each item in @var{files} must be a two-element list where the first element is the
7460 file name to use in the new directory, and the second element is a gexp
7461 denoting the target file. Here's an example:
7465 `(("hosts" ,(plain-file "hosts"
7466 "127.0.0.1 localhost"))
7467 ("bashrc" ,(plain-file "bashrc"
7468 "alias ls='ls --color=auto'"))))
7471 This yields an @code{etc} directory containing these two files.
7474 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
7475 Return a directory that is the union of @var{things}, where @var{things} is a list of
7476 file-like objects denoting directories. For example:
7479 (directory-union "guile+emacs" (list guile emacs))
7482 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
7485 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
7486 Return a file-like object that expands to the concatenation of @var{obj}
7487 and @var{suffix}, where @var{obj} is a lowerable object and each
7488 @var{suffix} is a string.
7490 As an example, consider this gexp:
7493 (gexp->script "run-uname"
7494 #~(system* #$(file-append coreutils
7498 The same effect could be achieved with:
7501 (gexp->script "run-uname"
7502 #~(system* (string-append #$coreutils
7506 There is one difference though: in the @code{file-append} case, the
7507 resulting script contains the absolute file name as a string, whereas in
7508 the second case, the resulting script contains a @code{(string-append
7509 @dots{})} expression to construct the file name @emph{at run time}.
7513 Of course, in addition to gexps embedded in ``host'' code, there are
7514 also modules containing build tools. To make it clear that they are
7515 meant to be used in the build stratum, these modules are kept in the
7516 @code{(guix build @dots{})} name space.
7518 @cindex lowering, of high-level objects in gexps
7519 Internally, high-level objects are @dfn{lowered}, using their compiler,
7520 to either derivations or store items. For instance, lowering a package
7521 yields a derivation, and lowering a @code{plain-file} yields a store
7522 item. This is achieved using the @code{lower-object} monadic procedure.
7524 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
7526 Return as a value in @var{%store-monad} the derivation or store item
7527 corresponding to @var{obj} for @var{system}, cross-compiling for
7528 @var{target} if @var{target} is true. @var{obj} must be an object that
7529 has an associated gexp compiler, such as a @code{<package>}.
7532 @node Invoking guix repl
7533 @section Invoking @command{guix repl}
7535 @cindex REPL, read-eval-print loop
7536 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
7537 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
7538 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
7539 command, @command{guix repl} guarantees that all the Guix modules and all its
7540 dependencies are available in the search path. You can use it this way:
7544 scheme@@(guile-user)> ,use (gnu packages base)
7545 scheme@@(guile-user)> coreutils
7546 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
7550 In addition, @command{guix repl} implements a simple machine-readable REPL
7551 protocol for use by @code{(guix inferior)}, a facility to interact with
7552 @dfn{inferiors}, separate processes running a potentially different revision
7555 The available options are as follows:
7558 @item --type=@var{type}
7559 @itemx -t @var{type}
7560 Start a REPL of the given @var{TYPE}, which can be one of the following:
7564 This is default, and it spawns a standard full-featured Guile REPL.
7566 Spawn a REPL that uses the machine-readable protocol. This is the protocol
7567 that the @code{(guix inferior)} module speaks.
7570 @item --listen=@var{endpoint}
7571 By default, @command{guix repl} reads from standard input and writes to
7572 standard output. When this option is passed, it will instead listen for
7573 connections on @var{endpoint}. Here are examples of valid options:
7576 @item --listen=tcp:37146
7577 Accept connections on localhost on port 37146.
7579 @item --listen=unix:/tmp/socket
7580 Accept connections on the Unix-domain socket @file{/tmp/socket}.
7584 @c *********************************************************************
7588 This section describes Guix command-line utilities. Some of them are
7589 primarily targeted at developers and users who write new package
7590 definitions, while others are more generally useful. They complement
7591 the Scheme programming interface of Guix in a convenient way.
7594 * Invoking guix build:: Building packages from the command line.
7595 * Invoking guix edit:: Editing package definitions.
7596 * Invoking guix download:: Downloading a file and printing its hash.
7597 * Invoking guix hash:: Computing the cryptographic hash of a file.
7598 * Invoking guix import:: Importing package definitions.
7599 * Invoking guix refresh:: Updating package definitions.
7600 * Invoking guix lint:: Finding errors in package definitions.
7601 * Invoking guix size:: Profiling disk usage.
7602 * Invoking guix graph:: Visualizing the graph of packages.
7603 * Invoking guix publish:: Sharing substitutes.
7604 * Invoking guix challenge:: Challenging substitute servers.
7605 * Invoking guix copy:: Copying to and from a remote store.
7606 * Invoking guix container:: Process isolation.
7607 * Invoking guix weather:: Assessing substitute availability.
7608 * Invoking guix processes:: Listing client processes.
7611 @node Invoking guix build
7612 @section Invoking @command{guix build}
7614 @cindex package building
7615 @cindex @command{guix build}
7616 The @command{guix build} command builds packages or derivations and
7617 their dependencies, and prints the resulting store paths. Note that it
7618 does not modify the user's profile---this is the job of the
7619 @command{guix package} command (@pxref{Invoking guix package}). Thus,
7620 it is mainly useful for distribution developers.
7622 The general syntax is:
7625 guix build @var{options} @var{package-or-derivation}@dots{}
7628 As an example, the following command builds the latest versions of Emacs
7629 and of Guile, displays their build logs, and finally displays the
7630 resulting directories:
7633 guix build emacs guile
7636 Similarly, the following command builds all the available packages:
7639 guix build --quiet --keep-going \
7640 `guix package -A | cut -f1,2 --output-delimiter=@@`
7643 @var{package-or-derivation} may be either the name of a package found in
7644 the software distribution such as @code{coreutils} or
7645 @code{coreutils@@8.20}, or a derivation such as
7646 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
7647 package with the corresponding name (and optionally version) is searched
7648 for among the GNU distribution modules (@pxref{Package Modules}).
7650 Alternatively, the @code{--expression} option may be used to specify a
7651 Scheme expression that evaluates to a package; this is useful when
7652 disambiguating among several same-named packages or package variants is
7655 There may be zero or more @var{options}. The available options are
7656 described in the subsections below.
7659 * Common Build Options:: Build options for most commands.
7660 * Package Transformation Options:: Creating variants of packages.
7661 * Additional Build Options:: Options specific to 'guix build'.
7662 * Debugging Build Failures:: Real life packaging experience.
7665 @node Common Build Options
7666 @subsection Common Build Options
7668 A number of options that control the build process are common to
7669 @command{guix build} and other commands that can spawn builds, such as
7670 @command{guix package} or @command{guix archive}. These are the
7675 @item --load-path=@var{directory}
7676 @itemx -L @var{directory}
7677 Add @var{directory} to the front of the package module search path
7678 (@pxref{Package Modules}).
7680 This allows users to define their own packages and make them visible to
7681 the command-line tools.
7685 Keep the build tree of failed builds. Thus, if a build fails, its build
7686 tree is kept under @file{/tmp}, in a directory whose name is shown at
7687 the end of the build log. This is useful when debugging build issues.
7688 @xref{Debugging Build Failures}, for tips and tricks on how to debug
7691 This option has no effect when connecting to a remote daemon with a
7692 @code{guix://} URI (@pxref{The Store, the @code{GUIX_DAEMON_SOCKET}
7697 Keep going when some of the derivations fail to build; return only once
7698 all the builds have either completed or failed.
7700 The default behavior is to stop as soon as one of the specified
7701 derivations has failed.
7705 Do not build the derivations.
7707 @anchor{fallback-option}
7709 When substituting a pre-built binary fails, fall back to building
7710 packages locally (@pxref{Substitution Failure}).
7712 @item --substitute-urls=@var{urls}
7713 @anchor{client-substitute-urls}
7714 Consider @var{urls} the whitespace-separated list of substitute source
7715 URLs, overriding the default list of URLs of @command{guix-daemon}
7716 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
7718 This means that substitutes may be downloaded from @var{urls}, provided
7719 they are signed by a key authorized by the system administrator
7720 (@pxref{Substitutes}).
7722 When @var{urls} is the empty string, substitutes are effectively
7725 @item --no-substitutes
7726 Do not use substitutes for build products. That is, always build things
7727 locally instead of allowing downloads of pre-built binaries
7728 (@pxref{Substitutes}).
7731 Do not ``graft'' packages. In practice, this means that package updates
7732 available as grafts are not applied. @xref{Security Updates}, for more
7733 information on grafts.
7735 @item --rounds=@var{n}
7736 Build each derivation @var{n} times in a row, and raise an error if
7737 consecutive build results are not bit-for-bit identical.
7739 This is a useful way to detect non-deterministic builds processes.
7740 Non-deterministic build processes are a problem because they make it
7741 practically impossible for users to @emph{verify} whether third-party
7742 binaries are genuine. @xref{Invoking guix challenge}, for more.
7744 Note that, currently, the differing build results are not kept around,
7745 so you will have to manually investigate in case of an error---e.g., by
7746 stashing one of the build results with @code{guix archive --export}
7747 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
7750 @item --no-build-hook
7751 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
7752 (@pxref{Daemon Offload Setup}). That is, always build things locally
7753 instead of offloading builds to remote machines.
7755 @item --max-silent-time=@var{seconds}
7756 When the build or substitution process remains silent for more than
7757 @var{seconds}, terminate it and report a build failure.
7759 By default, the daemon's setting is honored (@pxref{Invoking
7760 guix-daemon, @code{--max-silent-time}}).
7762 @item --timeout=@var{seconds}
7763 Likewise, when the build or substitution process lasts for more than
7764 @var{seconds}, terminate it and report a build failure.
7766 By default, the daemon's setting is honored (@pxref{Invoking
7767 guix-daemon, @code{--timeout}}).
7769 @c Note: This option is actually not part of %standard-build-options but
7770 @c most programs honor it.
7771 @cindex verbosity, of the command-line tools
7772 @cindex build logs, verbosity
7773 @item -v @var{level}
7774 @itemx --verbosity=@var{level}
7775 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
7776 output is produced, 1 is for quiet output, and 2 shows all the build log
7777 output on standard error.
7779 @item --cores=@var{n}
7781 Allow the use of up to @var{n} CPU cores for the build. The special
7782 value @code{0} means to use as many CPU cores as available.
7784 @item --max-jobs=@var{n}
7786 Allow at most @var{n} build jobs in parallel. @xref{Invoking
7787 guix-daemon, @code{--max-jobs}}, for details about this option and the
7788 equivalent @command{guix-daemon} option.
7790 @item --debug=@var{level}
7791 Produce debugging output coming from the build daemon. @var{level} must be an
7792 integer between 0 and 5; higher means more verbose output. Setting a level of
7793 4 or more may be helpful when debugging setup issues with the build daemon.
7797 Behind the scenes, @command{guix build} is essentially an interface to
7798 the @code{package-derivation} procedure of the @code{(guix packages)}
7799 module, and to the @code{build-derivations} procedure of the @code{(guix
7800 derivations)} module.
7802 In addition to options explicitly passed on the command line,
7803 @command{guix build} and other @command{guix} commands that support
7804 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
7806 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
7807 Users can define this variable to a list of command line options that
7808 will automatically be used by @command{guix build} and other
7809 @command{guix} commands that can perform builds, as in the example
7813 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
7816 These options are parsed independently, and the result is appended to
7817 the parsed command-line options.
7821 @node Package Transformation Options
7822 @subsection Package Transformation Options
7824 @cindex package variants
7825 Another set of command-line options supported by @command{guix build}
7826 and also @command{guix package} are @dfn{package transformation
7827 options}. These are options that make it possible to define @dfn{package
7828 variants}---for instance, packages built from different source code.
7829 This is a convenient way to create customized packages on the fly
7830 without having to type in the definitions of package variants
7831 (@pxref{Defining Packages}).
7835 @item --with-source=@var{source}
7836 @itemx --with-source=@var{package}=@var{source}
7837 @itemx --with-source=@var{package}@@@var{version}=@var{source}
7838 Use @var{source} as the source of @var{package}, and @var{version} as
7840 @var{source} must be a file name or a URL, as for @command{guix
7841 download} (@pxref{Invoking guix download}).
7843 When @var{package} is omitted,
7844 it is taken to be the package name specified on the
7845 command line that matches the base of @var{source}---e.g.,
7846 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
7847 package is @code{guile}.
7849 Likewise, when @var{version} is omitted, the version string is inferred from
7850 @var{source}; in the previous example, it is @code{2.0.10}.
7852 This option allows users to try out versions of packages other than the
7853 one provided by the distribution. The example below downloads
7854 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
7855 the @code{ed} package:
7858 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
7861 As a developer, @code{--with-source} makes it easy to test release
7865 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
7868 @dots{} or to build from a checkout in a pristine environment:
7871 $ git clone git://git.sv.gnu.org/guix.git
7872 $ guix build guix --with-source=guix@@1.0=./guix
7875 @item --with-input=@var{package}=@var{replacement}
7876 Replace dependency on @var{package} by a dependency on
7877 @var{replacement}. @var{package} must be a package name, and
7878 @var{replacement} must be a package specification such as @code{guile}
7879 or @code{guile@@1.8}.
7881 For instance, the following command builds Guix, but replaces its
7882 dependency on the current stable version of Guile with a dependency on
7883 the legacy version of Guile, @code{guile@@2.0}:
7886 guix build --with-input=guile=guile@@2.0 guix
7889 This is a recursive, deep replacement. So in this example, both
7890 @code{guix} and its dependency @code{guile-json} (which also depends on
7891 @code{guile}) get rebuilt against @code{guile@@2.0}.
7893 This is implemented using the @code{package-input-rewriting} Scheme
7894 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
7896 @item --with-graft=@var{package}=@var{replacement}
7897 This is similar to @code{--with-input} but with an important difference:
7898 instead of rebuilding the whole dependency chain, @var{replacement} is
7899 built and then @dfn{grafted} onto the binaries that were initially
7900 referring to @var{package}. @xref{Security Updates}, for more
7901 information on grafts.
7903 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
7904 and all its dependencies, replacing references to the version of GnuTLS
7905 they currently refer to:
7908 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
7911 This has the advantage of being much faster than rebuilding everything.
7912 But there is a caveat: it works if and only if @var{package} and
7913 @var{replacement} are strictly compatible---for example, if they provide
7914 a library, the application binary interface (ABI) of those libraries
7915 must be compatible. If @var{replacement} is somehow incompatible with
7916 @var{package}, then the resulting package may be unusable. Use with
7919 @item --with-git-url=@var{package}=@var{url}
7920 @cindex Git, using the latest commit
7921 @cindex latest commit, building
7922 Build @var{package} from the latest commit of the @code{master} branch of the
7923 Git repository at @var{url}. Git sub-modules of the repository are fetched,
7926 For example, the following command builds the NumPy Python library against the
7927 latest commit of the master branch of Python itself:
7930 guix build python-numpy \
7931 --with-git-url=python=https://github.com/python/cpython
7934 This option can also be combined with @code{--with-branch} or
7935 @code{--with-commit} (see below).
7937 @cindex continuous integration
7938 Obviously, since it uses the latest commit of the given branch, the result of
7939 such a command varies over time. Nevertheless it is a convenient way to
7940 rebuild entire software stacks against the latest commit of one or more
7941 packages. This is particularly useful in the context of continuous
7944 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
7945 consecutive accesses to the same repository. You may want to clean it up once
7946 in a while to save disk space.
7948 @item --with-branch=@var{package}=@var{branch}
7949 Build @var{package} from the latest commit of @var{branch}. If the
7950 @code{source} field of @var{package} is an origin with the @code{git-fetch}
7951 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
7952 repository URL is taken from that @code{source}. Otherwise you have to use
7953 @code{--with-git-url} to specify the URL of the Git repository.
7955 For instance, the following command builds @code{guile-sqlite3} from the
7956 latest commit of its @code{master} branch, and then builds @code{guix} (which
7957 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
7958 specific @code{guile-sqlite3} build:
7961 guix build --with-branch=guile-sqlite3=master cuirass
7964 @item --with-commit=@var{package}=@var{commit}
7965 This is similar to @code{--with-branch}, except that it builds from
7966 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
7967 Git commit SHA1 identifier.
7970 @node Additional Build Options
7971 @subsection Additional Build Options
7973 The command-line options presented below are specific to @command{guix
7980 Build quietly, without displaying the build log; this is equivalent to
7981 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
7982 (or similar) and can always be retrieved using the @option{--log-file} option.
7984 @item --file=@var{file}
7985 @itemx -f @var{file}
7986 Build the package, derivation, or other file-like object that the code within
7987 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
7989 As an example, @var{file} might contain a package definition like this
7990 (@pxref{Defining Packages}):
7993 @verbatiminclude package-hello.scm
7996 @item --expression=@var{expr}
7997 @itemx -e @var{expr}
7998 Build the package or derivation @var{expr} evaluates to.
8000 For example, @var{expr} may be @code{(@@ (gnu packages guile)
8001 guile-1.8)}, which unambiguously designates this specific variant of
8002 version 1.8 of Guile.
8004 Alternatively, @var{expr} may be a G-expression, in which case it is used
8005 as a build program passed to @code{gexp->derivation}
8006 (@pxref{G-Expressions}).
8008 Lastly, @var{expr} may refer to a zero-argument monadic procedure
8009 (@pxref{The Store Monad}). The procedure must return a derivation as a
8010 monadic value, which is then passed through @code{run-with-store}.
8014 Build the source derivations of the packages, rather than the packages
8017 For instance, @code{guix build -S gcc} returns something like
8018 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
8021 The returned source tarball is the result of applying any patches and
8022 code snippets specified in the package @code{origin} (@pxref{Defining
8026 Fetch and return the source of @var{package-or-derivation} and all their
8027 dependencies, recursively. This is a handy way to obtain a local copy
8028 of all the source code needed to build @var{packages}, allowing you to
8029 eventually build them even without network access. It is an extension
8030 of the @code{--source} option and can accept one of the following
8031 optional argument values:
8035 This value causes the @code{--sources} option to behave in the same way
8036 as the @code{--source} option.
8039 Build the source derivations of all packages, including any source that
8040 might be listed as @code{inputs}. This is the default value.
8043 $ guix build --sources tzdata
8044 The following derivations will be built:
8045 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
8046 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8050 Build the source derivations of all packages, as well of all transitive
8051 inputs to the packages. This can be used e.g.@: to
8052 prefetch package source for later offline building.
8055 $ guix build --sources=transitive tzdata
8056 The following derivations will be built:
8057 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8058 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
8059 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
8060 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
8061 /gnu/store/@dots{}-make-4.1.tar.xz.drv
8062 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
8068 @item --system=@var{system}
8069 @itemx -s @var{system}
8070 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
8071 the system type of the build host. The @command{guix build} command allows
8072 you to repeat this option several times, in which case it builds for all the
8073 specified systems; other commands ignore extraneous @option{-s} options.
8076 The @code{--system} flag is for @emph{native} compilation and must not
8077 be confused with cross-compilation. See @code{--target} below for
8078 information on cross-compilation.
8081 An example use of this is on Linux-based systems, which can emulate
8082 different personalities. For instance, passing
8083 @code{--system=i686-linux} on an @code{x86_64-linux} system or
8084 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
8085 to build packages in a complete 32-bit environment.
8088 Building for an @code{armhf-linux} system is unconditionally enabled on
8089 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8090 allow for this functionality, notably the ThunderX.
8093 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8094 is enabled (@pxref{Virtualization Services,
8095 @code{qemu-binfmt-service-type}}), you can build for any system for
8096 which a QEMU @code{binfmt_misc} handler is installed.
8098 Builds for a system other than that of the machine you are using can
8099 also be offloaded to a remote machine of the right architecture.
8100 @xref{Daemon Offload Setup}, for more information on offloading.
8102 @item --target=@var{triplet}
8103 @cindex cross-compilation
8104 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8105 as @code{"mips64el-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
8106 configuration triplets,, autoconf, Autoconf}).
8108 @anchor{build-check}
8110 @cindex determinism, checking
8111 @cindex reproducibility, checking
8112 Rebuild @var{package-or-derivation}, which are already available in the
8113 store, and raise an error if the build results are not bit-for-bit
8116 This mechanism allows you to check whether previously installed
8117 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8118 of a package is deterministic. @xref{Invoking guix challenge}, for more
8119 background information and tools.
8121 When used in conjunction with @option{--keep-failed}, the differing
8122 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8123 This makes it easy to look for differences between the two results.
8126 @cindex repairing store items
8127 @cindex corruption, recovering from
8128 Attempt to repair the specified store items, if they are corrupt, by
8129 re-downloading or rebuilding them.
8131 This operation is not atomic and thus restricted to @code{root}.
8135 Return the derivation paths, not the output paths, of the given
8138 @item --root=@var{file}
8139 @itemx -r @var{file}
8140 @cindex GC roots, adding
8141 @cindex garbage collector roots, adding
8142 Make @var{file} a symlink to the result, and register it as a garbage
8145 Consequently, the results of this @command{guix build} invocation are
8146 protected from garbage collection until @var{file} is removed. When
8147 that option is omitted, build results are eligible for garbage
8148 collection as soon as the build completes. @xref{Invoking guix gc}, for
8152 @cindex build logs, access
8153 Return the build log file names or URLs for the given
8154 @var{package-or-derivation}, or raise an error if build logs are
8157 This works regardless of how packages or derivations are specified. For
8158 instance, the following invocations are equivalent:
8161 guix build --log-file `guix build -d guile`
8162 guix build --log-file `guix build guile`
8163 guix build --log-file guile
8164 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8167 If a log is unavailable locally, and unless @code{--no-substitutes} is
8168 passed, the command looks for a corresponding log on one of the
8169 substitute servers (as specified with @code{--substitute-urls}.)
8171 So for instance, imagine you want to see the build log of GDB on MIPS,
8172 but you are actually on an @code{x86_64} machine:
8175 $ guix build --log-file gdb -s mips64el-linux
8176 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8179 You can freely access a huge library of build logs!
8182 @node Debugging Build Failures
8183 @subsection Debugging Build Failures
8185 @cindex build failures, debugging
8186 When defining a new package (@pxref{Defining Packages}), you will
8187 probably find yourself spending some time debugging and tweaking the
8188 build until it succeeds. To do that, you need to operate the build
8189 commands yourself in an environment as close as possible to the one the
8192 To that end, the first thing to do is to use the @option{--keep-failed}
8193 or @option{-K} option of @command{guix build}, which will keep the
8194 failed build tree in @file{/tmp} or whatever directory you specified as
8195 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8197 From there on, you can @command{cd} to the failed build tree and source
8198 the @file{environment-variables} file, which contains all the
8199 environment variable definitions that were in place when the build
8200 failed. So let's say you're debugging a build failure in package
8201 @code{foo}; a typical session would look like this:
8205 @dots{} @i{build fails}
8206 $ cd /tmp/guix-build-foo.drv-0
8207 $ source ./environment-variables
8211 Now, you can invoke commands as if you were the daemon (almost) and
8212 troubleshoot your build process.
8214 Sometimes it happens that, for example, a package's tests pass when you
8215 run them manually but they fail when the daemon runs them. This can
8216 happen because the daemon runs builds in containers where, unlike in our
8217 environment above, network access is missing, @file{/bin/sh} does not
8218 exist, etc. (@pxref{Build Environment Setup}).
8220 In such cases, you may need to run inspect the build process from within
8221 a container similar to the one the build daemon creates:
8226 $ cd /tmp/guix-build-foo.drv-0
8227 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8228 [env]# source ./environment-variables
8232 Here, @command{guix environment -C} creates a container and spawns a new
8233 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8234 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8235 the container, which would may find handy while debugging. The
8236 @option{--no-grafts} option makes sure we get the exact same
8237 environment, with ungrafted packages (@pxref{Security Updates}, for more
8240 To get closer to a container like that used by the build daemon, we can
8241 remove @file{/bin/sh}:
8247 (Don't worry, this is harmless: this is all happening in the throw-away
8248 container created by @command{guix environment}.)
8250 The @command{strace} command is probably not in the search path, but we
8254 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8257 In this way, not only you will have reproduced the environment variables
8258 the daemon uses, you will also be running the build process in a container
8259 similar to the one the daemon uses.
8262 @node Invoking guix edit
8263 @section Invoking @command{guix edit}
8265 @cindex @command{guix edit}
8266 @cindex package definition, editing
8267 So many packages, so many source files! The @command{guix edit} command
8268 facilitates the life of users and packagers by pointing their editor at
8269 the source file containing the definition of the specified packages.
8273 guix edit gcc@@4.9 vim
8277 launches the program specified in the @code{VISUAL} or in the
8278 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8281 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8282 have created your own packages on @code{GUIX_PACKAGE_PATH}
8283 (@pxref{Package Modules}), you will be able to edit the package
8284 recipes. In other cases, you will be able to examine the read-only recipes
8285 for packages currently in the store.
8288 @node Invoking guix download
8289 @section Invoking @command{guix download}
8291 @cindex @command{guix download}
8292 @cindex downloading package sources
8293 When writing a package definition, developers typically need to download
8294 a source tarball, compute its SHA256 hash, and write that
8295 hash in the package definition (@pxref{Defining Packages}). The
8296 @command{guix download} tool helps with this task: it downloads a file
8297 from the given URI, adds it to the store, and prints both its file name
8298 in the store and its SHA256 hash.
8300 The fact that the downloaded file is added to the store saves bandwidth:
8301 when the developer eventually tries to build the newly defined package
8302 with @command{guix build}, the source tarball will not have to be
8303 downloaded again because it is already in the store. It is also a
8304 convenient way to temporarily stash files, which may be deleted
8305 eventually (@pxref{Invoking guix gc}).
8307 The @command{guix download} command supports the same URIs as used in
8308 package definitions. In particular, it supports @code{mirror://} URIs.
8309 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8310 Guile bindings for GnuTLS are available in the user's environment; when
8311 they are not available, an error is raised. @xref{Guile Preparations,
8312 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8313 GnuTLS-Guile}, for more information.
8315 @command{guix download} verifies HTTPS server certificates by loading
8316 the certificates of X.509 authorities from the directory pointed to by
8317 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8318 Certificates}), unless @option{--no-check-certificate} is used.
8320 The following options are available:
8323 @item --format=@var{fmt}
8325 Write the hash in the format specified by @var{fmt}. For more
8326 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8328 @item --no-check-certificate
8329 Do not validate the X.509 certificates of HTTPS servers.
8331 When using this option, you have @emph{absolutely no guarantee} that you
8332 are communicating with the authentic server responsible for the given
8333 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8335 @item --output=@var{file}
8336 @itemx -o @var{file}
8337 Save the downloaded file to @var{file} instead of adding it to the
8341 @node Invoking guix hash
8342 @section Invoking @command{guix hash}
8344 @cindex @command{guix hash}
8345 The @command{guix hash} command computes the SHA256 hash of a file.
8346 It is primarily a convenience tool for anyone contributing to the
8347 distribution: it computes the cryptographic hash of a file, which can be
8348 used in the definition of a package (@pxref{Defining Packages}).
8350 The general syntax is:
8353 guix hash @var{option} @var{file}
8356 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8357 hash of data read from standard input. @command{guix hash} has the
8362 @item --format=@var{fmt}
8364 Write the hash in the format specified by @var{fmt}.
8366 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8367 (@code{hex} and @code{hexadecimal} can be used as well).
8369 If the @option{--format} option is not specified, @command{guix hash}
8370 will output the hash in @code{nix-base32}. This representation is used
8371 in the definitions of packages.
8375 Compute the hash on @var{file} recursively.
8377 In this case, the hash is computed on an archive containing @var{file},
8378 including its children if it is a directory. Some of the metadata of
8379 @var{file} is part of the archive; for instance, when @var{file} is a
8380 regular file, the hash is different depending on whether @var{file} is
8381 executable or not. Metadata such as time stamps has no impact on the
8382 hash (@pxref{Invoking guix archive}).
8383 @c FIXME: Replace xref above with xref to an ``Archive'' section when
8388 When combined with @option{--recursive}, exclude version control system
8389 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
8392 As an example, here is how you would compute the hash of a Git checkout,
8393 which is useful when using the @code{git-fetch} method (@pxref{origin
8397 $ git clone http://example.org/foo.git
8403 @node Invoking guix import
8404 @section Invoking @command{guix import}
8406 @cindex importing packages
8407 @cindex package import
8408 @cindex package conversion
8409 @cindex Invoking @command{guix import}
8410 The @command{guix import} command is useful for people who would like to
8411 add a package to the distribution with as little work as
8412 possible---a legitimate demand. The command knows of a few
8413 repositories from which it can ``import'' package metadata. The result
8414 is a package definition, or a template thereof, in the format we know
8415 (@pxref{Defining Packages}).
8417 The general syntax is:
8420 guix import @var{importer} @var{options}@dots{}
8423 @var{importer} specifies the source from which to import package
8424 metadata, and @var{options} specifies a package identifier and other
8425 options specific to @var{importer}. Currently, the available
8430 Import metadata for the given GNU package. This provides a template
8431 for the latest version of that GNU package, including the hash of its
8432 source tarball, and its canonical synopsis and description.
8434 Additional information such as the package dependencies and its
8435 license needs to be figured out manually.
8437 For example, the following command returns a package definition for
8441 guix import gnu hello
8444 Specific command-line options are:
8447 @item --key-download=@var{policy}
8448 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
8449 keys when verifying the package signature. @xref{Invoking guix
8450 refresh, @code{--key-download}}.
8455 Import metadata from the @uref{https://pypi.python.org/, Python Package
8456 Index}. Information is taken from the JSON-formatted description
8457 available at @code{pypi.python.org} and usually includes all the relevant
8458 information, including package dependencies. For maximum efficiency, it
8459 is recommended to install the @command{unzip} utility, so that the
8460 importer can unzip Python wheels and gather data from them.
8462 The command below imports metadata for the @code{itsdangerous} Python
8466 guix import pypi itsdangerous
8472 Traverse the dependency graph of the given upstream package recursively
8473 and generate package expressions for all those packages that are not yet
8479 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
8480 is taken from the JSON-formatted description available at
8481 @code{rubygems.org} and includes most relevant information, including
8482 runtime dependencies. There are some caveats, however. The metadata
8483 doesn't distinguish between synopses and descriptions, so the same string
8484 is used for both fields. Additionally, the details of non-Ruby
8485 dependencies required to build native extensions is unavailable and left
8486 as an exercise to the packager.
8488 The command below imports metadata for the @code{rails} Ruby package:
8491 guix import gem rails
8497 Traverse the dependency graph of the given upstream package recursively
8498 and generate package expressions for all those packages that are not yet
8504 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
8505 Information is taken from the JSON-formatted metadata provided through
8506 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
8507 relevant information, such as module dependencies. License information
8508 should be checked closely. If Perl is available in the store, then the
8509 @code{corelist} utility will be used to filter core modules out of the
8510 list of dependencies.
8512 The command command below imports metadata for the @code{Acme::Boolean}
8516 guix import cpan Acme::Boolean
8521 @cindex Bioconductor
8522 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
8523 central repository for the @uref{https://r-project.org, GNU@tie{}R
8524 statistical and graphical environment}.
8526 Information is extracted from the @code{DESCRIPTION} file of the package.
8528 The command command below imports metadata for the @code{Cairo}
8532 guix import cran Cairo
8535 When @code{--recursive} is added, the importer will traverse the
8536 dependency graph of the given upstream package recursively and generate
8537 package expressions for all those packages that are not yet in Guix.
8539 When @code{--archive=bioconductor} is added, metadata is imported from
8540 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
8541 packages for for the analysis and comprehension of high-throughput
8542 genomic data in bioinformatics.
8544 Information is extracted from the @code{DESCRIPTION} file of a package
8545 published on the web interface of the Bioconductor SVN repository.
8547 The command below imports metadata for the @code{GenomicRanges}
8551 guix import cran --archive=bioconductor GenomicRanges
8557 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
8558 comprehensive TeX archive network for TeX packages that are part of the
8559 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
8561 Information about the package is obtained through the XML API provided
8562 by CTAN, while the source code is downloaded from the SVN repository of
8563 the Tex Live project. This is done because the CTAN does not keep
8566 The command command below imports metadata for the @code{fontspec}
8570 guix import texlive fontspec
8573 When @code{--archive=DIRECTORY} is added, the source code is downloaded
8574 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
8575 tree in the TeX Live SVN repository, but from the specified sibling
8576 directory under the same root.
8578 The command below imports metadata for the @code{ifxetex} package from
8579 CTAN while fetching the sources from the directory
8580 @file{texmf/source/generic}:
8583 guix import texlive --archive=generic ifxetex
8587 @cindex JSON, import
8588 Import package metadata from a local JSON file. Consider the following
8589 example package definition in JSON format:
8595 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
8596 "build-system": "gnu",
8597 "home-page": "https://www.gnu.org/software/hello/",
8598 "synopsis": "Hello, GNU world: An example GNU package",
8599 "description": "GNU Hello prints a greeting.",
8600 "license": "GPL-3.0+",
8601 "native-inputs": ["gcc@@6"]
8605 The field names are the same as for the @code{<package>} record
8606 (@xref{Defining Packages}). References to other packages are provided
8607 as JSON lists of quoted package specification strings such as
8608 @code{guile} or @code{guile@@2.0}.
8610 The importer also supports a more explicit source definition using the
8611 common fields for @code{<origin>} records:
8617 "method": "url-fetch",
8618 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
8620 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
8627 The command below reads metadata from the JSON file @code{hello.json}
8628 and outputs a package expression:
8631 guix import json hello.json
8635 Import metadata from a local copy of the source of the
8636 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
8637 relies on the @command{nix-instantiate} command of
8638 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
8639 typically written in a mixture of Nix-language and Bash code. This
8640 command only imports the high-level package structure that is written in
8641 the Nix language. It normally includes all the basic fields of a
8644 When importing a GNU package, the synopsis and descriptions are replaced
8645 by their canonical upstream variant.
8647 Usually, you will first need to do:
8650 export NIX_REMOTE=daemon
8654 so that @command{nix-instantiate} does not try to open the Nix database.
8656 As an example, the command below imports the package definition of
8657 LibreOffice (more precisely, it imports the definition of the package
8658 bound to the @code{libreoffice} top-level attribute):
8661 guix import nix ~/path/to/nixpkgs libreoffice
8666 Import metadata from the Haskell community's central package archive
8667 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
8668 Cabal files and includes all the relevant information, including package
8671 Specific command-line options are:
8676 Read a Cabal file from standard input.
8677 @item --no-test-dependencies
8679 Do not include dependencies required only by the test suites.
8680 @item --cabal-environment=@var{alist}
8681 @itemx -e @var{alist}
8682 @var{alist} is a Scheme alist defining the environment in which the
8683 Cabal conditionals are evaluated. The accepted keys are: @code{os},
8684 @code{arch}, @code{impl} and a string representing the name of a flag.
8685 The value associated with a flag has to be either the symbol
8686 @code{true} or @code{false}. The value associated with other keys
8687 has to conform to the Cabal file format definition. The default value
8688 associated with the keys @code{os}, @code{arch} and @code{impl} is
8689 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
8692 Traverse the dependency graph of the given upstream package recursively
8693 and generate package expressions for all those packages that are not yet
8697 The command below imports metadata for the latest version of the
8698 @code{HTTP} Haskell package without including test dependencies and
8699 specifying the value of the flag @samp{network-uri} as @code{false}:
8702 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
8705 A specific package version may optionally be specified by following the
8706 package name by an at-sign and a version number as in the following example:
8709 guix import hackage mtl@@2.1.3.1
8714 The @code{stackage} importer is a wrapper around the @code{hackage} one.
8715 It takes a package name, looks up the package version included in a
8716 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
8717 release and uses the @code{hackage} importer to retrieve its metadata.
8718 Note that it is up to you to select an LTS release compatible with the
8719 GHC compiler used by Guix.
8721 Specific command-line options are:
8724 @item --no-test-dependencies
8726 Do not include dependencies required only by the test suites.
8727 @item --lts-version=@var{version}
8728 @itemx -l @var{version}
8729 @var{version} is the desired LTS release version. If omitted the latest
8733 Traverse the dependency graph of the given upstream package recursively
8734 and generate package expressions for all those packages that are not yet
8738 The command below imports metadata for the @code{HTTP} Haskell package
8739 included in the LTS Stackage release version 7.18:
8742 guix import stackage --lts-version=7.18 HTTP
8747 Import metadata from an Emacs Lisp Package Archive (ELPA) package
8748 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
8750 Specific command-line options are:
8753 @item --archive=@var{repo}
8754 @itemx -a @var{repo}
8755 @var{repo} identifies the archive repository from which to retrieve the
8756 information. Currently the supported repositories and their identifiers
8760 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
8761 identifier. This is the default.
8763 Packages from @code{elpa.gnu.org} are signed with one of the keys
8764 contained in the GnuPG keyring at
8765 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
8766 @code{emacs} package (@pxref{Package Installation, ELPA package
8767 signatures,, emacs, The GNU Emacs Manual}).
8770 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
8771 @code{melpa-stable} identifier.
8774 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
8780 Traverse the dependency graph of the given upstream package recursively
8781 and generate package expressions for all those packages that are not yet
8787 Import metadata from the crates.io Rust package repository
8788 @uref{https://crates.io, crates.io}.
8793 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
8794 repository used by the OCaml community.
8797 The structure of the @command{guix import} code is modular. It would be
8798 useful to have more importers for other package formats, and your help
8799 is welcome here (@pxref{Contributing}).
8801 @node Invoking guix refresh
8802 @section Invoking @command{guix refresh}
8804 @cindex @command {guix refresh}
8805 The primary audience of the @command{guix refresh} command is developers
8806 of the GNU software distribution. By default, it reports any packages
8807 provided by the distribution that are outdated compared to the latest
8808 upstream version, like this:
8812 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
8813 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
8816 Alternately, one can specify packages to consider, in which case a
8817 warning is emitted for packages that lack an updater:
8820 $ guix refresh coreutils guile guile-ssh
8821 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
8822 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
8825 @command{guix refresh} browses the upstream repository of each package and determines
8826 the highest version number of the releases therein. The command
8827 knows how to update specific types of packages: GNU packages, ELPA
8828 packages, etc.---see the documentation for @option{--type} below. There
8829 are many packages, though, for which it lacks a method to determine
8830 whether a new upstream release is available. However, the mechanism is
8831 extensible, so feel free to get in touch with us to add a new method!
8836 Consider the packages specified, and all the packages upon which they depend.
8839 $ guix refresh --recursive coreutils
8840 gnu/packages/acl.scm:35:2: warning: no updater for acl
8841 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
8842 gnu/packages/xml.scm:68:2: warning: no updater for expat
8843 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
8849 Sometimes the upstream name differs from the package name used in Guix,
8850 and @command{guix refresh} needs a little help. Most updaters honor the
8851 @code{upstream-name} property in package definitions, which can be used
8855 (define-public network-manager
8857 (name "network-manager")
8859 (properties '((upstream-name . "NetworkManager")))))
8862 When passed @code{--update}, it modifies distribution source files to
8863 update the version numbers and source tarball hashes of those package
8864 recipes (@pxref{Defining Packages}). This is achieved by downloading
8865 each package's latest source tarball and its associated OpenPGP
8866 signature, authenticating the downloaded tarball against its signature
8867 using @command{gpg}, and finally computing its hash. When the public
8868 key used to sign the tarball is missing from the user's keyring, an
8869 attempt is made to automatically retrieve it from a public key server;
8870 when this is successful, the key is added to the user's keyring; otherwise,
8871 @command{guix refresh} reports an error.
8873 The following options are supported:
8877 @item --expression=@var{expr}
8878 @itemx -e @var{expr}
8879 Consider the package @var{expr} evaluates to.
8881 This is useful to precisely refer to a package, as in this example:
8884 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
8887 This command lists the dependents of the ``final'' libc (essentially all
8892 Update distribution source files (package recipes) in place. This is
8893 usually run from a checkout of the Guix source tree (@pxref{Running
8894 Guix Before It Is Installed}):
8897 $ ./pre-inst-env guix refresh -s non-core -u
8900 @xref{Defining Packages}, for more information on package definitions.
8902 @item --select=[@var{subset}]
8903 @itemx -s @var{subset}
8904 Select all the packages in @var{subset}, one of @code{core} or
8907 The @code{core} subset refers to all the packages at the core of the
8908 distribution---i.e., packages that are used to build ``everything
8909 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
8910 changing one of these packages in the distribution entails a rebuild of
8911 all the others. Thus, such updates are an inconvenience to users in
8912 terms of build time or bandwidth used to achieve the upgrade.
8914 The @code{non-core} subset refers to the remaining packages. It is
8915 typically useful in cases where an update of the core packages would be
8918 @item --manifest=@var{file}
8919 @itemx -m @var{file}
8920 Select all the packages from the manifest in @var{file}. This is useful to
8921 check if any packages of the user manifest can be updated.
8923 @item --type=@var{updater}
8924 @itemx -t @var{updater}
8925 Select only packages handled by @var{updater} (may be a comma-separated
8926 list of updaters). Currently, @var{updater} may be one of:
8930 the updater for GNU packages;
8932 the updater for GNOME packages;
8934 the updater for KDE packages;
8936 the updater for X.org packages;
8938 the updater for packages hosted on kernel.org;
8940 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
8942 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
8944 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
8946 the updater for @uref{https://www.cpan.org/, CPAN} packages;
8948 the updater for @uref{https://pypi.python.org, PyPI} packages.
8950 the updater for @uref{https://rubygems.org, RubyGems} packages.
8952 the updater for @uref{https://github.com, GitHub} packages.
8954 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
8956 the updater for @uref{https://www.stackage.org, Stackage} packages.
8958 the updater for @uref{https://crates.io, Crates} packages.
8960 the updater for @uref{https://launchpad.net, Launchpad} packages.
8963 For instance, the following command only checks for updates of Emacs
8964 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
8967 $ guix refresh --type=elpa,cran
8968 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
8969 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
8974 In addition, @command{guix refresh} can be passed one or more package
8975 names, as in this example:
8978 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
8982 The command above specifically updates the @code{emacs} and
8983 @code{idutils} packages. The @code{--select} option would have no
8984 effect in this case.
8986 When considering whether to upgrade a package, it is sometimes
8987 convenient to know which packages would be affected by the upgrade and
8988 should be checked for compatibility. For this the following option may
8989 be used when passing @command{guix refresh} one or more package names:
8993 @item --list-updaters
8995 List available updaters and exit (see @option{--type} above.)
8997 For each updater, display the fraction of packages it covers; at the
8998 end, display the fraction of packages covered by all these updaters.
9000 @item --list-dependent
9002 List top-level dependent packages that would need to be rebuilt as a
9003 result of upgrading one or more packages.
9005 @xref{Invoking guix graph, the @code{reverse-package} type of
9006 @command{guix graph}}, for information on how to visualize the list of
9007 dependents of a package.
9011 Be aware that the @code{--list-dependent} option only
9012 @emph{approximates} the rebuilds that would be required as a result of
9013 an upgrade. More rebuilds might be required under some circumstances.
9016 $ guix refresh --list-dependent flex
9017 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
9018 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
9021 The command above lists a set of packages that could be built to check
9022 for compatibility with an upgraded @code{flex} package.
9026 @item --list-transitive
9027 List all the packages which one or more packages depend upon.
9030 $ guix refresh --list-transitive flex
9031 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
9032 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{}
9037 The command above lists a set of packages which, when changed, would cause
9038 @code{flex} to be rebuilt.
9040 The following options can be used to customize GnuPG operation:
9044 @item --gpg=@var{command}
9045 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
9046 for in @code{$PATH}.
9048 @item --keyring=@var{file}
9049 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
9050 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
9051 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
9052 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
9053 information on a tool to manipulate keybox files).
9055 When this option is omitted, @command{guix refresh} uses
9056 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
9057 signing keys. OpenPGP signatures are checked against keys from this keyring;
9058 missing keys are downloaded to this keyring as well (see
9059 @option{--key-download} below.)
9061 You can export keys from your default GPG keyring into a keybox file using
9062 commands like this one:
9065 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
9068 Likewise, you can fetch keys to a specific keybox file like this:
9071 gpg --no-default-keyring --keyring mykeyring.kbx \
9072 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9075 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9076 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9078 @item --key-download=@var{policy}
9079 Handle missing OpenPGP keys according to @var{policy}, which may be one
9084 Always download missing OpenPGP keys from the key server, and add them
9085 to the user's GnuPG keyring.
9088 Never try to download missing OpenPGP keys. Instead just bail out.
9091 When a package signed with an unknown OpenPGP key is encountered, ask
9092 the user whether to download it or not. This is the default behavior.
9095 @item --key-server=@var{host}
9096 Use @var{host} as the OpenPGP key server when importing a public key.
9100 The @code{github} updater uses the
9101 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9102 releases. When used repeatedly e.g.@: when refreshing all packages,
9103 GitHub will eventually refuse to answer any further API requests. By
9104 default 60 API requests per hour are allowed, and a full refresh on all
9105 GitHub packages in Guix requires more than this. Authentication with
9106 GitHub through the use of an API token alleviates these limits. To use
9107 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9108 token procured from @uref{https://github.com/settings/tokens} or
9112 @node Invoking guix lint
9113 @section Invoking @command{guix lint}
9115 @cindex @command{guix lint}
9116 @cindex package, checking for errors
9117 The @command{guix lint} command is meant to help package developers avoid
9118 common errors and use a consistent style. It runs a number of checks on
9119 a given set of packages in order to find common mistakes in their
9120 definitions. Available @dfn{checkers} include (see
9121 @code{--list-checkers} for a complete list):
9126 Validate certain typographical and stylistic rules about package
9127 descriptions and synopses.
9129 @item inputs-should-be-native
9130 Identify inputs that should most likely be native inputs.
9136 @itemx source-file-name
9137 Probe @code{home-page} and @code{source} URLs and report those that are
9138 invalid. Suggest a @code{mirror://} URL when applicable. If the
9139 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9140 URL. Check that the source file name is meaningful, e.g.@: is not just a
9141 version number or ``git-checkout'', without a declared @code{file-name}
9142 (@pxref{origin Reference}).
9144 @item source-unstable-tarball
9145 Parse the @code{source} URL to determine if a tarball from GitHub is
9146 autogenerated or if it is a release tarball. Unfortunately GitHub's
9147 autogenerated tarballs are sometimes regenerated.
9150 @cindex security vulnerabilities
9151 @cindex CVE, Common Vulnerabilities and Exposures
9152 Report known vulnerabilities found in the Common Vulnerabilities and
9153 Exposures (CVE) databases of the current and past year
9154 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
9157 To view information about a particular vulnerability, visit pages such as:
9161 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9163 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9167 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9168 @code{CVE-2015-7554}.
9170 Package developers can specify in package recipes the
9171 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
9172 name and version of the package when they differ from the name or version
9173 that Guix uses, as in this example:
9179 ;; CPE calls this package "grub2".
9180 (properties '((cpe-name . "grub2")
9181 (cpe-version . "2.3")))
9184 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
9185 Some entries in the CVE database do not specify which version of a
9186 package they apply to, and would thus ``stick around'' forever. Package
9187 developers who found CVE alerts and verified they can be ignored can
9188 declare them as in this example:
9194 ;; These CVEs no longer apply and can be safely ignored.
9195 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9198 "CVE-2011-5244")))))
9202 Warn about obvious source code formatting issues: trailing white space,
9203 use of tabulations, etc.
9206 The general syntax is:
9209 guix lint @var{options} @var{package}@dots{}
9212 If no package is given on the command line, then all packages are checked.
9213 The @var{options} may be zero or more of the following:
9216 @item --list-checkers
9218 List and describe all the available checkers that will be run on packages
9223 Only enable the checkers specified in a comma-separated list using the
9224 names returned by @code{--list-checkers}.
9228 @node Invoking guix size
9229 @section Invoking @command{guix size}
9232 @cindex package size
9234 @cindex @command{guix size}
9235 The @command{guix size} command helps package developers profile the
9236 disk usage of packages. It is easy to overlook the impact of an
9237 additional dependency added to a package, or the impact of using a
9238 single output for a package that could easily be split (@pxref{Packages
9239 with Multiple Outputs}). Such are the typical issues that
9240 @command{guix size} can highlight.
9242 The command can be passed one or more package specifications
9243 such as @code{gcc@@4.8}
9244 or @code{guile:debug}, or a file name in the store. Consider this
9248 $ guix size coreutils
9249 store item total self
9250 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9251 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9252 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9253 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9254 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9255 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9256 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9257 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9262 The store items listed here constitute the @dfn{transitive closure} of
9263 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9264 would be returned by:
9267 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9270 Here the output shows three columns next to store items. The first column,
9271 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9272 the store item---that is, its own size plus the size of all its
9273 dependencies. The next column, labeled ``self'', shows the size of the
9274 item itself. The last column shows the ratio of the size of the item
9275 itself to the space occupied by all the items listed here.
9277 In this example, we see that the closure of Coreutils weighs in at
9278 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9279 libraries. (That libc and GCC's libraries represent a large fraction of
9280 the closure is not a problem @i{per se} because they are always available
9281 on the system anyway.)
9283 When the package(s) passed to @command{guix size} are available in the
9284 store@footnote{More precisely, @command{guix size} looks for the
9285 @emph{ungrafted} variant of the given package(s), as returned by
9286 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9287 for information on grafts.}, @command{guix size} queries the daemon to determine its
9288 dependencies, and measures its size in the store, similar to @command{du
9289 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9292 When the given packages are @emph{not} in the store, @command{guix size}
9293 reports information based on the available substitutes
9294 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9295 store items that are not even on disk, only available remotely.
9297 You can also specify several package names:
9300 $ guix size coreutils grep sed bash
9301 store item total self
9302 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9303 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9304 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9305 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
9311 In this example we see that the combination of the four packages takes
9312 102.3@tie{}MiB in total, which is much less than the sum of each closure
9313 since they have a lot of dependencies in common.
9315 The available options are:
9319 @item --substitute-urls=@var{urls}
9320 Use substitute information from @var{urls}.
9321 @xref{client-substitute-urls, the same option for @code{guix build}}.
9323 @item --sort=@var{key}
9324 Sort lines according to @var{key}, one of the following options:
9328 the size of each item (the default);
9330 the total size of the item's closure.
9333 @item --map-file=@var{file}
9334 Write a graphical map of disk usage in PNG format to @var{file}.
9336 For the example above, the map looks like this:
9338 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
9339 produced by @command{guix size}}
9341 This option requires that
9342 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
9343 installed and visible in Guile's module search path. When that is not
9344 the case, @command{guix size} fails as it tries to load it.
9346 @item --system=@var{system}
9347 @itemx -s @var{system}
9348 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
9352 @node Invoking guix graph
9353 @section Invoking @command{guix graph}
9356 @cindex @command{guix graph}
9357 @cindex package dependencies
9358 Packages and their dependencies form a @dfn{graph}, specifically a
9359 directed acyclic graph (DAG). It can quickly become difficult to have a
9360 mental model of the package DAG, so the @command{guix graph} command
9361 provides a visual representation of the DAG. By default,
9362 @command{guix graph} emits a DAG representation in the input format of
9363 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
9364 directly to the @command{dot} command of Graphviz. It can also emit an
9365 HTML page with embedded JavaScript code to display a ``chord diagram''
9366 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
9367 emit Cypher queries to construct a graph in a graph database supporting
9368 the @uref{https://www.opencypher.org/, openCypher} query language.
9369 The general syntax is:
9372 guix graph @var{options} @var{package}@dots{}
9375 For example, the following command generates a PDF file representing the
9376 package DAG for the GNU@tie{}Core Utilities, showing its build-time
9380 guix graph coreutils | dot -Tpdf > dag.pdf
9383 The output looks like this:
9385 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
9387 Nice little graph, no?
9389 But there is more than one graph! The one above is concise: it is the
9390 graph of package objects, omitting implicit inputs such as GCC, libc,
9391 grep, etc. It is often useful to have such a concise graph, but
9392 sometimes one may want to see more details. @command{guix graph} supports
9393 several types of graphs, allowing you to choose the level of detail:
9397 This is the default type used in the example above. It shows the DAG of
9398 package objects, excluding implicit dependencies. It is concise, but
9399 filters out many details.
9401 @item reverse-package
9402 This shows the @emph{reverse} DAG of packages. For example:
9405 guix graph --type=reverse-package ocaml
9408 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
9409 you are also interested in cases where OCaml is an implicit dependency, see
9410 @code{reverse-bag} below.)
9412 Note that for core packages this can yield huge graphs. If all you want
9413 is to know the number of packages that depend on a given package, use
9414 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
9415 @option{--list-dependent}}).
9418 This is the package DAG, @emph{including} implicit inputs.
9420 For instance, the following command:
9423 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
9426 ...@: yields this bigger graph:
9428 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
9430 At the bottom of the graph, we see all the implicit inputs of
9431 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
9433 Now, note that the dependencies of these implicit inputs---that is, the
9434 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
9435 here, for conciseness.
9438 Similar to @code{bag-emerged}, but this time including all the bootstrap
9441 @item bag-with-origins
9442 Similar to @code{bag}, but also showing origins and their dependencies.
9445 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
9446 it also takes implicit dependencies into account. For example:
9449 guix graph -t reverse-bag dune
9453 ...@: yields the graph of all packages that depend on Dune, directly or
9454 indirectly. Since Dune is an @emph{implicit} dependency of many packages
9455 @i{via} @code{dune-build-system}, this shows a large number of packages,
9456 whereas @code{reverse-package} would show very few if any.
9459 This is the most detailed representation: It shows the DAG of
9460 derivations (@pxref{Derivations}) and plain store items. Compared to
9461 the above representation, many additional nodes are visible, including
9462 build scripts, patches, Guile modules, etc.
9464 For this type of graph, it is also possible to pass a @file{.drv} file
9465 name instead of a package name, as in:
9468 guix graph -t derivation `guix system build -d my-config.scm`
9472 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
9473 For example, the following command shows the graph for the package
9474 module that defines the @code{guile} package:
9477 guix graph -t module guile | dot -Tpdf > module-graph.pdf
9481 All the types above correspond to @emph{build-time dependencies}. The
9482 following graph type represents the @emph{run-time dependencies}:
9486 This is the graph of @dfn{references} of a package output, as returned
9487 by @command{guix gc --references} (@pxref{Invoking guix gc}).
9489 If the given package output is not available in the store, @command{guix
9490 graph} attempts to obtain dependency information from substitutes.
9492 Here you can also pass a store file name instead of a package name. For
9493 example, the command below produces the reference graph of your profile
9494 (which can be big!):
9497 guix graph -t references `readlink -f ~/.guix-profile`
9501 This is the graph of the @dfn{referrers} of a store item, as returned by
9502 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
9504 This relies exclusively on local information from your store. For
9505 instance, let us suppose that the current Inkscape is available in 10
9506 profiles on your machine; @command{guix graph -t referrers inkscape}
9507 will show a graph rooted at Inkscape and with those 10 profiles linked
9510 It can help determine what is preventing a store item from being garbage
9515 The available options are the following:
9518 @item --type=@var{type}
9519 @itemx -t @var{type}
9520 Produce a graph output of @var{type}, where @var{type} must be one of
9521 the values listed above.
9524 List the supported graph types.
9526 @item --backend=@var{backend}
9527 @itemx -b @var{backend}
9528 Produce a graph using the selected @var{backend}.
9530 @item --list-backends
9531 List the supported graph backends.
9533 Currently, the available backends are Graphviz and d3.js.
9535 @item --expression=@var{expr}
9536 @itemx -e @var{expr}
9537 Consider the package @var{expr} evaluates to.
9539 This is useful to precisely refer to a package, as in this example:
9542 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
9545 @item --system=@var{system}
9546 @itemx -s @var{system}
9547 Display the graph for @var{system}---e.g., @code{i686-linux}.
9549 The package dependency graph is largely architecture-independent, but there
9550 are some architecture-dependent bits that this option allows you to visualize.
9555 @node Invoking guix publish
9556 @section Invoking @command{guix publish}
9558 @cindex @command{guix publish}
9559 The purpose of @command{guix publish} is to enable users to easily share
9560 their store with others, who can then use it as a substitute server
9561 (@pxref{Substitutes}).
9563 When @command{guix publish} runs, it spawns an HTTP server which allows
9564 anyone with network access to obtain substitutes from it. This means
9565 that any machine running Guix can also act as if it were a build farm,
9566 since the HTTP interface is compatible with Hydra, the software behind
9567 the @code{@value{SUBSTITUTE-SERVER}} build farm.
9569 For security, each substitute is signed, allowing recipients to check
9570 their authenticity and integrity (@pxref{Substitutes}). Because
9571 @command{guix publish} uses the signing key of the system, which is only
9572 readable by the system administrator, it must be started as root; the
9573 @code{--user} option makes it drop root privileges early on.
9575 The signing key pair must be generated before @command{guix publish} is
9576 launched, using @command{guix archive --generate-key} (@pxref{Invoking
9579 The general syntax is:
9582 guix publish @var{options}@dots{}
9585 Running @command{guix publish} without any additional arguments will
9586 spawn an HTTP server on port 8080:
9592 Once a publishing server has been authorized (@pxref{Invoking guix
9593 archive}), the daemon may download substitutes from it:
9596 guix-daemon --substitute-urls=http://example.org:8080
9599 By default, @command{guix publish} compresses archives on the fly as it
9600 serves them. This ``on-the-fly'' mode is convenient in that it requires
9601 no setup and is immediately available. However, when serving lots of
9602 clients, we recommend using the @option{--cache} option, which enables
9603 caching of the archives before they are sent to clients---see below for
9604 details. The @command{guix weather} command provides a handy way to
9605 check what a server provides (@pxref{Invoking guix weather}).
9607 As a bonus, @command{guix publish} also serves as a content-addressed
9608 mirror for source files referenced in @code{origin} records
9609 (@pxref{origin Reference}). For instance, assuming @command{guix
9610 publish} is running on @code{example.org}, the following URL returns the
9611 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
9612 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
9615 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
9618 Obviously, these URLs only work for files that are in the store; in
9619 other cases, they return 404 (``Not Found'').
9621 @cindex build logs, publication
9622 Build logs are available from @code{/log} URLs like:
9625 http://example.org/log/gwspk@dots{}-guile-2.2.3
9629 When @command{guix-daemon} is configured to save compressed build logs,
9630 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
9631 URLs return the compressed log as-is, with an appropriate
9632 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
9633 running @command{guix-daemon} with @code{--log-compression=gzip} since
9634 Web browsers can automatically decompress it, which is not the case with
9637 The following options are available:
9640 @item --port=@var{port}
9641 @itemx -p @var{port}
9642 Listen for HTTP requests on @var{port}.
9644 @item --listen=@var{host}
9645 Listen on the network interface for @var{host}. The default is to
9646 accept connections from any interface.
9648 @item --user=@var{user}
9649 @itemx -u @var{user}
9650 Change privileges to @var{user} as soon as possible---i.e., once the
9651 server socket is open and the signing key has been read.
9653 @item --compression[=@var{level}]
9654 @itemx -C [@var{level}]
9655 Compress data using the given @var{level}. When @var{level} is zero,
9656 disable compression. The range 1 to 9 corresponds to different gzip
9657 compression levels: 1 is the fastest, and 9 is the best (CPU-intensive).
9660 Unless @option{--cache} is used, compression occurs on the fly and
9661 the compressed streams are not
9662 cached. Thus, to reduce load on the machine that runs @command{guix
9663 publish}, it may be a good idea to choose a low compression level, to
9664 run @command{guix publish} behind a caching proxy, or to use
9665 @option{--cache}. Using @option{--cache} has the advantage that it
9666 allows @command{guix publish} to add @code{Content-Length} HTTP header
9669 @item --cache=@var{directory}
9670 @itemx -c @var{directory}
9671 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
9672 and only serve archives that are in cache.
9674 When this option is omitted, archives and meta-data are created
9675 on-the-fly. This can reduce the available bandwidth, especially when
9676 compression is enabled, since this may become CPU-bound. Another
9677 drawback of the default mode is that the length of archives is not known
9678 in advance, so @command{guix publish} does not add a
9679 @code{Content-Length} HTTP header to its responses, which in turn
9680 prevents clients from knowing the amount of data being downloaded.
9682 Conversely, when @option{--cache} is used, the first request for a store
9683 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
9684 background process to @dfn{bake} the archive---computing its
9685 @code{.narinfo} and compressing the archive, if needed. Once the
9686 archive is cached in @var{directory}, subsequent requests succeed and
9687 are served directly from the cache, which guarantees that clients get
9688 the best possible bandwidth.
9690 The ``baking'' process is performed by worker threads. By default, one
9691 thread per CPU core is created, but this can be customized. See
9692 @option{--workers} below.
9694 When @option{--ttl} is used, cached entries are automatically deleted
9695 when they have expired.
9697 @item --workers=@var{N}
9698 When @option{--cache} is used, request the allocation of @var{N} worker
9699 threads to ``bake'' archives.
9701 @item --ttl=@var{ttl}
9702 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
9703 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
9704 days, @code{1m} means 1 month, and so on.
9706 This allows the user's Guix to keep substitute information in cache for
9707 @var{ttl}. However, note that @code{guix publish} does not itself
9708 guarantee that the store items it provides will indeed remain available
9709 for as long as @var{ttl}.
9711 Additionally, when @option{--cache} is used, cached entries that have
9712 not been accessed for @var{ttl} and that no longer have a corresponding
9713 item in the store, may be deleted.
9715 @item --nar-path=@var{path}
9716 Use @var{path} as the prefix for the URLs of ``nar'' files
9717 (@pxref{Invoking guix archive, normalized archives}).
9719 By default, nars are served at a URL such as
9720 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
9721 change the @code{/nar} part to @var{path}.
9723 @item --public-key=@var{file}
9724 @itemx --private-key=@var{file}
9725 Use the specific @var{file}s as the public/private key pair used to sign
9726 the store items being published.
9728 The files must correspond to the same key pair (the private key is used
9729 for signing and the public key is merely advertised in the signature
9730 metadata). They must contain keys in the canonical s-expression format
9731 as produced by @command{guix archive --generate-key} (@pxref{Invoking
9732 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
9733 @file{/etc/guix/signing-key.sec} are used.
9735 @item --repl[=@var{port}]
9736 @itemx -r [@var{port}]
9737 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
9738 Reference Manual}) on @var{port} (37146 by default). This is used
9739 primarily for debugging a running @command{guix publish} server.
9742 Enabling @command{guix publish} on Guix System is a one-liner: just
9743 instantiate a @code{guix-publish-service-type} service in the @code{services} field
9744 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
9745 @code{guix-publish-service-type}}).
9747 If you are instead running Guix on a ``foreign distro'', follow these
9752 If your host distro uses the systemd init system:
9755 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
9756 /etc/systemd/system/
9757 # systemctl start guix-publish && systemctl enable guix-publish
9761 If your host distro uses the Upstart init system:
9764 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
9765 # start guix-publish
9769 Otherwise, proceed similarly with your distro's init system.
9772 @node Invoking guix challenge
9773 @section Invoking @command{guix challenge}
9775 @cindex reproducible builds
9776 @cindex verifiable builds
9777 @cindex @command{guix challenge}
9779 Do the binaries provided by this server really correspond to the source
9780 code it claims to build? Is a package build process deterministic?
9781 These are the questions the @command{guix challenge} command attempts to
9784 The former is obviously an important question: Before using a substitute
9785 server (@pxref{Substitutes}), one had better @emph{verify} that it
9786 provides the right binaries, and thus @emph{challenge} it. The latter
9787 is what enables the former: If package builds are deterministic, then
9788 independent builds of the package should yield the exact same result,
9789 bit for bit; if a server provides a binary different from the one
9790 obtained locally, it may be either corrupt or malicious.
9792 We know that the hash that shows up in @file{/gnu/store} file names is
9793 the hash of all the inputs of the process that built the file or
9794 directory---compilers, libraries, build scripts,
9795 etc. (@pxref{Introduction}). Assuming deterministic build processes,
9796 one store file name should map to exactly one build output.
9797 @command{guix challenge} checks whether there is, indeed, a single
9798 mapping by comparing the build outputs of several independent builds of
9799 any given store item.
9801 The command output looks like this:
9804 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
9805 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
9806 updating list of substitutes from 'https://guix.example.org'... 100.0%
9807 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
9808 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9809 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9810 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
9811 /gnu/store/@dots{}-git-2.5.0 contents differ:
9812 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
9813 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
9814 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
9815 /gnu/store/@dots{}-pius-2.1.1 contents differ:
9816 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9817 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9818 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
9822 6,406 store items were analyzed:
9823 - 4,749 (74.1%) were identical
9824 - 525 (8.2%) differed
9825 - 1,132 (17.7%) were inconclusive
9829 In this example, @command{guix challenge} first scans the store to
9830 determine the set of locally-built derivations---as opposed to store
9831 items that were downloaded from a substitute server---and then queries
9832 all the substitute servers. It then reports those store items for which
9833 the servers obtained a result different from the local build.
9835 @cindex non-determinism, in package builds
9836 As an example, @code{guix.example.org} always gets a different answer.
9837 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
9838 case of Git. This might indicate that the build process of Git is
9839 non-deterministic, meaning that its output varies as a function of
9840 various things that Guix does not fully control, in spite of building
9841 packages in isolated environments (@pxref{Features}). Most common
9842 sources of non-determinism include the addition of timestamps in build
9843 results, the inclusion of random numbers, and directory listings sorted
9844 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
9847 To find out what is wrong with this Git binary, we can do something along
9848 these lines (@pxref{Invoking guix archive}):
9851 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
9852 | guix archive -x /tmp/git
9853 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
9856 This command shows the difference between the files resulting from the
9857 local build, and the files resulting from the build on
9858 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
9859 diffutils, Comparing and Merging Files}). The @command{diff} command
9860 works great for text files. When binary files differ, a better option
9861 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
9862 visualize differences for all kinds of files.
9864 Once you have done that work, you can tell whether the differences are due
9865 to a non-deterministic build process or to a malicious server. We try
9866 hard to remove sources of non-determinism in packages to make it easier
9867 to verify substitutes, but of course, this is a process that
9868 involves not just Guix, but a large part of the free software community.
9869 In the meantime, @command{guix challenge} is one tool to help address
9872 If you are writing packages for Guix, you are encouraged to check
9873 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
9874 same build result as you did with:
9877 $ guix challenge @var{package}
9881 where @var{package} is a package specification such as
9882 @code{guile@@2.0} or @code{glibc:debug}.
9884 The general syntax is:
9887 guix challenge @var{options} [@var{packages}@dots{}]
9890 When a difference is found between the hash of a locally-built item and
9891 that of a server-provided substitute, or among substitutes provided by
9892 different servers, the command displays it as in the example above and
9893 its exit code is 2 (other non-zero exit codes denote other kinds of
9896 The one option that matters is:
9900 @item --substitute-urls=@var{urls}
9901 Consider @var{urls} the whitespace-separated list of substitute source
9906 Show details about matches (identical contents) in addition to
9907 information about mismatches.
9911 @node Invoking guix copy
9912 @section Invoking @command{guix copy}
9914 @cindex copy, of store items, over SSH
9915 @cindex SSH, copy of store items
9916 @cindex sharing store items across machines
9917 @cindex transferring store items across machines
9918 The @command{guix copy} command copies items from the store of one
9919 machine to that of another machine over a secure shell (SSH)
9920 connection@footnote{This command is available only when Guile-SSH was
9921 found. @xref{Requirements}, for details.}. For example, the following
9922 command copies the @code{coreutils} package, the user's profile, and all
9923 their dependencies over to @var{host}, logged in as @var{user}:
9926 guix copy --to=@var{user}@@@var{host} \
9927 coreutils `readlink -f ~/.guix-profile`
9930 If some of the items to be copied are already present on @var{host},
9931 they are not actually sent.
9933 The command below retrieves @code{libreoffice} and @code{gimp} from
9934 @var{host}, assuming they are available there:
9937 guix copy --from=@var{host} libreoffice gimp
9940 The SSH connection is established using the Guile-SSH client, which is
9941 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
9942 @file{~/.ssh/config}, and uses the SSH agent for authentication.
9944 The key used to sign items that are sent must be accepted by the remote
9945 machine. Likewise, the key used by the remote machine to sign items you
9946 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
9947 own daemon. @xref{Invoking guix archive}, for more information about
9948 store item authentication.
9950 The general syntax is:
9953 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
9956 You must always specify one of the following options:
9959 @item --to=@var{spec}
9960 @itemx --from=@var{spec}
9961 Specify the host to send to or receive from. @var{spec} must be an SSH
9962 spec such as @code{example.org}, @code{charlie@@example.org}, or
9963 @code{charlie@@example.org:2222}.
9966 The @var{items} can be either package names, such as @code{gimp}, or
9967 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
9969 When specifying the name of a package to send, it is first built if
9970 needed, unless @option{--dry-run} was specified. Common build options
9971 are supported (@pxref{Common Build Options}).
9974 @node Invoking guix container
9975 @section Invoking @command{guix container}
9977 @cindex @command{guix container}
9979 As of version @value{VERSION}, this tool is experimental. The interface
9980 is subject to radical change in the future.
9983 The purpose of @command{guix container} is to manipulate processes
9984 running within an isolated environment, commonly known as a
9985 ``container'', typically created by the @command{guix environment}
9986 (@pxref{Invoking guix environment}) and @command{guix system container}
9987 (@pxref{Invoking guix system}) commands.
9989 The general syntax is:
9992 guix container @var{action} @var{options}@dots{}
9995 @var{action} specifies the operation to perform with a container, and
9996 @var{options} specifies the context-specific arguments for the action.
9998 The following actions are available:
10002 Execute a command within the context of a running container.
10007 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
10010 @var{pid} specifies the process ID of the running container.
10011 @var{program} specifies an executable file name within the root file
10012 system of the container. @var{arguments} are the additional options that
10013 will be passed to @var{program}.
10015 The following command launches an interactive login shell inside a
10016 Guix system container, started by @command{guix system container}, and whose
10017 process ID is 9001:
10020 guix container exec 9001 /run/current-system/profile/bin/bash --login
10023 Note that the @var{pid} cannot be the parent process of a container. It
10024 must be PID 1 of the container or one of its child processes.
10028 @node Invoking guix weather
10029 @section Invoking @command{guix weather}
10031 Occasionally you're grumpy because substitutes are lacking and you end
10032 up building packages by yourself (@pxref{Substitutes}). The
10033 @command{guix weather} command reports on substitute availability on the
10034 specified servers so you can have an idea of whether you'll be grumpy
10035 today. It can sometimes be useful info as a user, but it is primarily
10036 useful to people running @command{guix publish} (@pxref{Invoking guix
10039 @cindex statistics, for substitutes
10040 @cindex availability of substitutes
10041 @cindex substitute availability
10042 @cindex weather, substitute availability
10043 Here's a sample run:
10046 $ guix weather --substitute-urls=https://guix.example.org
10047 computing 5,872 package derivations for x86_64-linux...
10048 looking for 6,128 store items on https://guix.example.org..
10049 updating list of substitutes from 'https://guix.example.org'... 100.0%
10050 https://guix.example.org
10051 43.4% substitutes available (2,658 out of 6,128)
10052 7,032.5 MiB of nars (compressed)
10053 19,824.2 MiB on disk (uncompressed)
10054 0.030 seconds per request (182.9 seconds in total)
10055 33.5 requests per second
10057 9.8% (342 out of 3,470) of the missing items are queued
10059 x86_64-linux: 518 (59.7%)
10060 i686-linux: 221 (25.5%)
10061 aarch64-linux: 128 (14.8%)
10062 build rate: 23.41 builds per hour
10063 x86_64-linux: 11.16 builds per hour
10064 i686-linux: 6.03 builds per hour
10065 aarch64-linux: 6.41 builds per hour
10068 @cindex continuous integration, statistics
10069 As you can see, it reports the fraction of all the packages for which
10070 substitutes are available on the server---regardless of whether
10071 substitutes are enabled, and regardless of whether this server's signing
10072 key is authorized. It also reports the size of the compressed archives
10073 (``nars'') provided by the server, the size the corresponding store
10074 items occupy in the store (assuming deduplication is turned off), and
10075 the server's throughput. The second part gives continuous integration
10076 (CI) statistics, if the server supports it. In addition, using the
10077 @option{--coverage} option, @command{guix weather} can list ``important''
10078 package substitutes missing on the server (see below).
10080 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10081 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10082 challenge}, it ignores signatures on those substitutes, which is
10083 innocuous since the command only gathers statistics and cannot install
10086 Among other things, it is possible to query specific system types and
10087 specific package sets. The available options are listed below.
10090 @item --substitute-urls=@var{urls}
10091 @var{urls} is the space-separated list of substitute server URLs to
10092 query. When this option is omitted, the default set of substitute
10093 servers is queried.
10095 @item --system=@var{system}
10096 @itemx -s @var{system}
10097 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10098 option can be repeated, in which case @command{guix weather} will query
10099 substitutes for several system types.
10101 @item --manifest=@var{file}
10102 Instead of querying substitutes for all the packages, only ask for those
10103 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10104 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10107 @item --coverage[=@var{count}]
10108 @itemx -c [@var{count}]
10109 Report on substitute coverage for packages: list packages with at least
10110 @var{count} dependents (zero by default) for which substitutes are
10111 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10112 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10113 @var{b} usually lacks substitutes as well. The result looks like this:
10116 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
10117 computing 8,983 package derivations for x86_64-linux...
10118 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
10119 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
10120 @value{SUBSTITUTE-URL}
10121 64.7% substitutes available (6,047 out of 9,343)
10123 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
10124 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10125 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10126 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10130 What this example shows is that @code{kcoreaddons} and presumably the 58
10131 packages that depend on it have no substitutes at @code{ci.guix.info};
10132 likewise for @code{qgpgme} and the 46 packages that depend on it.
10134 If you are a Guix developer, or if you are taking care of this build farm,
10135 you'll probably want to have a closer look at these packages: they may simply
10139 @node Invoking guix processes
10140 @section Invoking @command{guix processes}
10142 The @command{guix processes} command can be useful to developers and system
10143 administrators, especially on multi-user machines and on build farms: it lists
10144 the current sessions (connections to the daemon), as well as information about
10145 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10146 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10147 listed.}. Here's an example of the information it returns:
10150 $ sudo guix processes
10153 ClientCommand: guix environment --ad-hoc python
10157 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10161 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10162 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10163 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10164 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10165 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10166 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10167 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10170 In this example we see that @command{guix-daemon} has three clients:
10171 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10172 integration tool; their process identifier (PID) is given by the
10173 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10174 @command{guix-daemon} sub-process of this particular session.
10176 The @code{LockHeld} fields show which store items are currently locked by this
10177 session, which corresponds to store items being built or substituted (the
10178 @code{LockHeld} field is not displayed when @command{guix processes} is not
10179 running as root.) Last, by looking at the @code{ChildProcess} field, we
10180 understand that these three builds are being offloaded (@pxref{Daemon Offload
10183 The output is in Recutils format so we can use the handy @command{recsel}
10184 command to select sessions of interest (@pxref{Selection Expressions,,,
10185 recutils, GNU recutils manual}). As an example, the command shows the command
10186 line and PID of the client that triggered the build of a Perl package:
10189 $ sudo guix processes | \
10190 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10192 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10196 @node System Configuration
10197 @chapter System Configuration
10199 @cindex system configuration
10200 Guix System supports a consistent whole-system configuration
10201 mechanism. By that we mean that all aspects of the global system
10202 configuration---such as the available system services, timezone and
10203 locale settings, user accounts---are declared in a single place. Such
10204 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10206 One of the advantages of putting all the system configuration under the
10207 control of Guix is that it supports transactional system upgrades, and
10208 makes it possible to roll back to a previous system instantiation,
10209 should something go wrong with the new one (@pxref{Features}). Another
10210 advantage is that it makes it easy to replicate the exact same configuration
10211 across different machines, or at different points in time, without
10212 having to resort to additional administration tools layered on top of
10213 the own tools of the system.
10214 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
10216 This section describes this mechanism. First we focus on the system
10217 administrator's viewpoint---explaining how the system is configured and
10218 instantiated. Then we show how this mechanism can be extended, for
10219 instance to support new system services.
10222 * Using the Configuration System:: Customizing your GNU system.
10223 * operating-system Reference:: Detail of operating-system declarations.
10224 * File Systems:: Configuring file system mounts.
10225 * Mapped Devices:: Block device extra processing.
10226 * User Accounts:: Specifying user accounts.
10227 * Keyboard Layout:: How the system interprets key strokes.
10228 * Locales:: Language and cultural convention settings.
10229 * Services:: Specifying system services.
10230 * Setuid Programs:: Programs running with root privileges.
10231 * X.509 Certificates:: Authenticating HTTPS servers.
10232 * Name Service Switch:: Configuring libc's name service switch.
10233 * Initial RAM Disk:: Linux-Libre bootstrapping.
10234 * Bootloader Configuration:: Configuring the boot loader.
10235 * Invoking guix system:: Instantiating a system configuration.
10236 * Running Guix in a VM:: How to run Guix System in a virtual machine.
10237 * Defining Services:: Adding new service definitions.
10240 @node Using the Configuration System
10241 @section Using the Configuration System
10243 The operating system is configured by providing an
10244 @code{operating-system} declaration in a file that can then be passed to
10245 the @command{guix system} command (@pxref{Invoking guix system}). A
10246 simple setup, with the default system services, the default Linux-Libre
10247 kernel, initial RAM disk, and boot loader looks like this:
10249 @findex operating-system
10251 @include os-config-bare-bones.texi
10254 This example should be self-describing. Some of the fields defined
10255 above, such as @code{host-name} and @code{bootloader}, are mandatory.
10256 Others, such as @code{packages} and @code{services}, can be omitted, in
10257 which case they get a default value.
10259 Below we discuss the effect of some of the most important fields
10260 (@pxref{operating-system Reference}, for details about all the available
10261 fields), and how to @dfn{instantiate} the operating system using
10262 @command{guix system}.
10264 @unnumberedsubsec Bootloader
10266 @cindex legacy boot, on Intel machines
10267 @cindex BIOS boot, on Intel machines
10270 The @code{bootloader} field describes the method that will be used to boot
10271 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
10272 mode, as in the example above. However, more recent machines rely instead on
10273 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
10274 the @code{bootloader} field should contain something along these lines:
10277 (bootloader-configuration
10278 (bootloader grub-efi-bootloader)
10279 (target "/boot/efi"))
10282 @xref{Bootloader Configuration}, for more information on the available
10283 configuration options.
10285 @unnumberedsubsec Globally-Visible Packages
10287 @vindex %base-packages
10288 The @code{packages} field lists packages that will be globally visible
10289 on the system, for all user accounts---i.e., in every user's @code{PATH}
10290 environment variable---in addition to the per-user profiles
10291 (@pxref{Invoking guix package}). The @var{%base-packages} variable
10292 provides all the tools one would expect for basic user and administrator
10293 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
10294 the GNU Zile lightweight text editor, @command{find}, @command{grep},
10295 etc. The example above adds GNU@tie{}Screen to those,
10296 taken from the @code{(gnu packages screen)}
10297 module (@pxref{Package Modules}). The
10298 @code{(list package output)} syntax can be used to add a specific output
10302 (use-modules (gnu packages))
10303 (use-modules (gnu packages dns))
10307 (packages (cons (list bind "utils")
10311 @findex specification->package
10312 Referring to packages by variable name, like @code{bind} above, has
10313 the advantage of being unambiguous; it also allows typos and such to be
10314 diagnosed right away as ``unbound variables''. The downside is that one
10315 needs to know which module defines which package, and to augment the
10316 @code{use-package-modules} line accordingly. To avoid that, one can use
10317 the @code{specification->package} procedure of the @code{(gnu packages)}
10318 module, which returns the best package for a given name or name and
10322 (use-modules (gnu packages))
10326 (packages (append (map specification->package
10327 '("tcpdump" "htop" "gnupg@@2.0"))
10331 @unnumberedsubsec System Services
10334 @vindex %base-services
10335 The @code{services} field lists @dfn{system services} to be made
10336 available when the system starts (@pxref{Services}).
10337 The @code{operating-system} declaration above specifies that, in
10338 addition to the basic services, we want the OpenSSH secure shell
10339 daemon listening on port 2222 (@pxref{Networking Services,
10340 @code{openssh-service-type}}). Under the hood,
10341 @code{openssh-service-type} arranges so that @command{sshd} is started with the
10342 right command-line options, possibly with supporting configuration files
10343 generated as needed (@pxref{Defining Services}).
10345 @cindex customization, of services
10346 @findex modify-services
10347 Occasionally, instead of using the base services as is, you will want to
10348 customize them. To do this, use @code{modify-services} (@pxref{Service
10349 Reference, @code{modify-services}}) to modify the list.
10351 For example, suppose you want to modify @code{guix-daemon} and Mingetty
10352 (the console log-in) in the @var{%base-services} list (@pxref{Base
10353 Services, @code{%base-services}}). To do that, you can write the
10354 following in your operating system declaration:
10357 (define %my-services
10358 ;; My very own list of services.
10359 (modify-services %base-services
10360 (guix-service-type config =>
10361 (guix-configuration
10363 (use-substitutes? #f)
10364 (extra-options '("--gc-keep-derivations"))))
10365 (mingetty-service-type config =>
10366 (mingetty-configuration
10367 (inherit config)))))
10371 (services %my-services))
10374 This changes the configuration---i.e., the service parameters---of the
10375 @code{guix-service-type} instance, and that of all the
10376 @code{mingetty-service-type} instances in the @var{%base-services} list.
10377 Observe how this is accomplished: first, we arrange for the original
10378 configuration to be bound to the identifier @code{config} in the
10379 @var{body}, and then we write the @var{body} so that it evaluates to the
10380 desired configuration. In particular, notice how we use @code{inherit}
10381 to create a new configuration which has the same values as the old
10382 configuration, but with a few modifications.
10384 @cindex encrypted disk
10385 The configuration for a typical ``desktop'' usage, with an encrypted
10386 root partition, the X11 display
10387 server, GNOME and Xfce (users can choose which of these desktop
10388 environments to use at the log-in screen by pressing @kbd{F1}), network
10389 management, power management, and more, would look like this:
10392 @include os-config-desktop.texi
10395 A graphical system with a choice of lightweight window managers
10396 instead of full-blown desktop environments would look like this:
10399 @include os-config-lightweight-desktop.texi
10402 This example refers to the @file{/boot/efi} file system by its UUID,
10403 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
10404 as returned by the @command{blkid} command.
10406 @xref{Desktop Services}, for the exact list of services provided by
10407 @var{%desktop-services}. @xref{X.509 Certificates}, for background
10408 information about the @code{nss-certs} package that is used here.
10410 Again, @var{%desktop-services} is just a list of service objects. If
10411 you want to remove services from there, you can do so using the
10412 procedures for list filtering (@pxref{SRFI-1 Filtering and
10413 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
10414 following expression returns a list that contains all the services in
10415 @var{%desktop-services} minus the Avahi service:
10418 (remove (lambda (service)
10419 (eq? (service-kind service) avahi-service-type))
10423 @unnumberedsubsec Instantiating the System
10425 Assuming the @code{operating-system} declaration
10426 is stored in the @file{my-system-config.scm}
10427 file, the @command{guix system reconfigure my-system-config.scm} command
10428 instantiates that configuration, and makes it the default GRUB boot
10429 entry (@pxref{Invoking guix system}).
10431 The normal way to change the system configuration is by updating this
10432 file and re-running @command{guix system reconfigure}. One should never
10433 have to touch files in @file{/etc} or to run commands that modify the
10434 system state such as @command{useradd} or @command{grub-install}. In
10435 fact, you must avoid that since that would not only void your warranty
10436 but also prevent you from rolling back to previous versions of your
10437 system, should you ever need to.
10439 @cindex roll-back, of the operating system
10440 Speaking of roll-back, each time you run @command{guix system
10441 reconfigure}, a new @dfn{generation} of the system is created---without
10442 modifying or deleting previous generations. Old system generations get
10443 an entry in the bootloader boot menu, allowing you to boot them in case
10444 something went wrong with the latest generation. Reassuring, no? The
10445 @command{guix system list-generations} command lists the system
10446 generations available on disk. It is also possible to roll back the
10447 system via the commands @command{guix system roll-back} and
10448 @command{guix system switch-generation}.
10450 Although the @command{guix system reconfigure} command will not modify
10451 previous generations, you must take care when the current generation is not
10452 the latest (e.g., after invoking @command{guix system roll-back}), since
10453 the operation might overwrite a later generation (@pxref{Invoking guix
10456 @unnumberedsubsec The Programming Interface
10458 At the Scheme level, the bulk of an @code{operating-system} declaration
10459 is instantiated with the following monadic procedure (@pxref{The Store
10462 @deffn {Monadic Procedure} operating-system-derivation os
10463 Return a derivation that builds @var{os}, an @code{operating-system}
10464 object (@pxref{Derivations}).
10466 The output of the derivation is a single directory that refers to all
10467 the packages, configuration files, and other supporting files needed to
10468 instantiate @var{os}.
10471 This procedure is provided by the @code{(gnu system)} module. Along
10472 with @code{(gnu services)} (@pxref{Services}), this module contains the
10473 guts of Guix System. Make sure to visit it!
10476 @node operating-system Reference
10477 @section @code{operating-system} Reference
10479 This section summarizes all the options available in
10480 @code{operating-system} declarations (@pxref{Using the Configuration
10483 @deftp {Data Type} operating-system
10484 This is the data type representing an operating system configuration.
10485 By that, we mean all the global system configuration, not per-user
10486 configuration (@pxref{Using the Configuration System}).
10489 @item @code{kernel} (default: @var{linux-libre})
10490 The package object of the operating system kernel to use@footnote{Currently
10491 only the Linux-libre kernel is supported. In the future, it will be
10492 possible to use the GNU@tie{}Hurd.}.
10494 @item @code{kernel-arguments} (default: @code{'("quiet")})
10495 List of strings or gexps representing additional arguments to pass on
10496 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
10498 @item @code{bootloader}
10499 The system bootloader configuration object. @xref{Bootloader Configuration}.
10502 This is the label (a string) as it appears in the bootloader's menu entry.
10503 The default label includes the kernel name and version.
10505 @item @code{keyboard-layout} (default: @code{#f})
10506 This field specifies the keyboard layout to use in the console. It can be
10507 either @code{#f}, in which case the default keyboard layout is used (usually
10508 US English), or a @code{<keyboard-layout>} record.
10510 This keyboard layout is in effect as soon as the kernel has booted. For
10511 instance, it is the keyboard layout in effect when you type a passphrase if
10512 your root file system is on a @code{luks-device-mapping} mapped device
10513 (@pxref{Mapped Devices}).
10516 This does @emph{not} specify the keyboard layout used by the bootloader, nor
10517 that used by the graphical display server. @xref{Bootloader Configuration},
10518 for information on how to specify the bootloader's keyboard layout. @xref{X
10519 Window}, for information on how to specify the keyboard layout used by the X
10523 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
10525 @cindex initial RAM disk
10526 The list of Linux kernel modules that need to be available in the
10527 initial RAM disk. @xref{Initial RAM Disk}.
10529 @item @code{initrd} (default: @code{base-initrd})
10530 A procedure that returns an initial RAM disk for the Linux
10531 kernel. This field is provided to support low-level customization and
10532 should rarely be needed for casual use. @xref{Initial RAM Disk}.
10534 @item @code{firmware} (default: @var{%base-firmware})
10536 List of firmware packages loadable by the operating system kernel.
10538 The default includes firmware needed for Atheros- and Broadcom-based
10539 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
10540 respectively). @xref{Hardware Considerations}, for more info on
10541 supported hardware.
10543 @item @code{host-name}
10546 @item @code{hosts-file}
10548 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
10549 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
10550 Reference Manual}). The default is a file with entries for
10551 @code{localhost} and @var{host-name}.
10553 @item @code{mapped-devices} (default: @code{'()})
10554 A list of mapped devices. @xref{Mapped Devices}.
10556 @item @code{file-systems}
10557 A list of file systems. @xref{File Systems}.
10559 @item @code{swap-devices} (default: @code{'()})
10560 @cindex swap devices
10561 A list of strings identifying devices or files to be used for ``swap
10562 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
10563 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
10564 It is possible to specify a swap file in a file system on a mapped
10565 device, provided that the necessary device mapping and file system are
10566 also specified. @xref{Mapped Devices} and @ref{File Systems}.
10568 @item @code{users} (default: @code{%base-user-accounts})
10569 @itemx @code{groups} (default: @var{%base-groups})
10570 List of user accounts and groups. @xref{User Accounts}.
10572 If the @code{users} list lacks a user account with UID@tie{}0, a
10573 ``root'' account with UID@tie{}0 is automatically added.
10575 @item @code{skeletons} (default: @code{(default-skeletons)})
10576 A list target file name/file-like object tuples (@pxref{G-Expressions,
10577 file-like objects}). These are the skeleton files that will be added to
10578 the home directory of newly-created user accounts.
10580 For instance, a valid value may look like this:
10583 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
10584 (".guile" ,(plain-file "guile"
10585 "(use-modules (ice-9 readline))
10586 (activate-readline)")))
10589 @item @code{issue} (default: @var{%default-issue})
10590 A string denoting the contents of the @file{/etc/issue} file, which is
10591 displayed when users log in on a text console.
10593 @item @code{packages} (default: @var{%base-packages})
10594 The set of packages installed in the global profile, which is accessible
10595 at @file{/run/current-system/profile}.
10597 The default set includes core utilities and it is good practice to
10598 install non-core utilities in user profiles (@pxref{Invoking guix
10601 @item @code{timezone}
10602 A timezone identifying string---e.g., @code{"Europe/Paris"}.
10604 You can run the @command{tzselect} command to find out which timezone
10605 string corresponds to your region. Choosing an invalid timezone name
10606 causes @command{guix system} to fail.
10608 @item @code{locale} (default: @code{"en_US.utf8"})
10609 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
10610 Library Reference Manual}). @xref{Locales}, for more information.
10612 @item @code{locale-definitions} (default: @var{%default-locale-definitions})
10613 The list of locale definitions to be compiled and that may be used at
10614 run time. @xref{Locales}.
10616 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
10617 The list of GNU@tie{}libc packages whose locale data and tools are used
10618 to build the locale definitions. @xref{Locales}, for compatibility
10619 considerations that justify this option.
10621 @item @code{name-service-switch} (default: @var{%default-nss})
10622 Configuration of the libc name service switch (NSS)---a
10623 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
10626 @item @code{services} (default: @var{%base-services})
10627 A list of service objects denoting system services. @xref{Services}.
10629 @cindex essential services
10630 @item @code{essential-services} (default: ...)
10631 The list of ``essential services''---i.e., things like instances of
10632 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
10633 Reference}), which are derived from the operating system definition itself.
10634 As a user you should @emph{never} need to touch this field.
10636 @item @code{pam-services} (default: @code{(base-pam-services)})
10638 @cindex pluggable authentication modules
10639 Linux @dfn{pluggable authentication module} (PAM) services.
10640 @c FIXME: Add xref to PAM services section.
10642 @item @code{setuid-programs} (default: @var{%setuid-programs})
10643 List of string-valued G-expressions denoting setuid programs.
10644 @xref{Setuid Programs}.
10646 @item @code{sudoers-file} (default: @var{%sudoers-specification})
10647 @cindex sudoers file
10648 The contents of the @file{/etc/sudoers} file as a file-like object
10649 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
10651 This file specifies which users can use the @command{sudo} command, what
10652 they are allowed to do, and what privileges they may gain. The default
10653 is that only @code{root} and members of the @code{wheel} group may use
10658 @deffn {Scheme Syntax} this-operating-system
10659 When used in the @emph{lexical scope} of an operating system field definition,
10660 this identifier resolves to the operating system being defined.
10662 The example below shows how to refer to the operating system being defined in
10663 the definition of the @code{label} field:
10666 (use-modules (gnu) (guix))
10670 (label (package-full-name
10671 (operating-system-kernel this-operating-system))))
10674 It is an error to refer to @code{this-operating-system} outside an operating
10681 @section File Systems
10683 The list of file systems to be mounted is specified in the
10684 @code{file-systems} field of the operating system declaration
10685 (@pxref{Using the Configuration System}). Each file system is declared
10686 using the @code{file-system} form, like this:
10690 (mount-point "/home")
10691 (device "/dev/sda3")
10695 As usual, some of the fields are mandatory---those shown in the example
10696 above---while others can be omitted. These are described below.
10698 @deftp {Data Type} file-system
10699 Objects of this type represent file systems to be mounted. They
10700 contain the following members:
10704 This is a string specifying the type of the file system---e.g.,
10707 @item @code{mount-point}
10708 This designates the place where the file system is to be mounted.
10710 @item @code{device}
10711 This names the ``source'' of the file system. It can be one of three
10712 things: a file system label, a file system UUID, or the name of a
10713 @file{/dev} node. Labels and UUIDs offer a way to refer to file
10714 systems without having to hard-code their actual device
10715 name@footnote{Note that, while it is tempting to use
10716 @file{/dev/disk/by-uuid} and similar device names to achieve the same
10717 result, this is not recommended: These special device nodes are created
10718 by the udev daemon and may be unavailable at the time the device is
10721 @findex file-system-label
10722 File system labels are created using the @code{file-system-label}
10723 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
10724 plain strings. Here's an example of a file system referred to by its
10725 label, as shown by the @command{e2label} command:
10729 (mount-point "/home")
10731 (device (file-system-label "my-home")))
10735 UUIDs are converted from their string representation (as shown by the
10736 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
10737 @code{uuid} form expects 16-byte UUIDs as defined in
10738 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
10739 form of UUID used by the ext2 family of file systems and others, but it
10740 is different from ``UUIDs'' found in FAT file systems, for instance.},
10745 (mount-point "/home")
10747 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
10750 When the source of a file system is a mapped device (@pxref{Mapped
10751 Devices}), its @code{device} field @emph{must} refer to the mapped
10752 device name---e.g., @file{"/dev/mapper/root-partition"}.
10753 This is required so that
10754 the system knows that mounting the file system depends on having the
10755 corresponding device mapping established.
10757 @item @code{flags} (default: @code{'()})
10758 This is a list of symbols denoting mount flags. Recognized flags
10759 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
10760 access to special files), @code{no-suid} (ignore setuid and setgid
10761 bits), @code{no-atime} (do not update file access times), and @code{no-exec}
10762 (disallow program execution). @xref{Mount-Unmount-Remount,,, libc, The GNU C
10763 Library Reference Manual}, for more information on these flags.
10765 @item @code{options} (default: @code{#f})
10766 This is either @code{#f}, or a string denoting mount options passed to the
10767 file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
10768 Reference Manual}, for details and run @command{man 8 mount} for options for
10769 various file systems.
10771 @item @code{mount?} (default: @code{#t})
10772 This value indicates whether to automatically mount the file system when
10773 the system is brought up. When set to @code{#f}, the file system gets
10774 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
10775 is not automatically mounted.
10777 @item @code{needed-for-boot?} (default: @code{#f})
10778 This Boolean value indicates whether the file system is needed when
10779 booting. If that is true, then the file system is mounted when the
10780 initial RAM disk (initrd) is loaded. This is always the case, for
10781 instance, for the root file system.
10783 @item @code{check?} (default: @code{#t})
10784 This Boolean indicates whether the file system needs to be checked for
10785 errors before being mounted.
10787 @item @code{create-mount-point?} (default: @code{#f})
10788 When true, the mount point is created if it does not exist yet.
10790 @item @code{dependencies} (default: @code{'()})
10791 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
10792 representing file systems that must be mounted or mapped devices that
10793 must be opened before (and unmounted or closed after) this one.
10795 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
10796 a dependency of @file{/sys/fs/cgroup/cpu} and
10797 @file{/sys/fs/cgroup/memory}.
10799 Another example is a file system that depends on a mapped device, for
10800 example for an encrypted partition (@pxref{Mapped Devices}).
10804 The @code{(gnu system file-systems)} exports the following useful
10807 @defvr {Scheme Variable} %base-file-systems
10808 These are essential file systems that are required on normal systems,
10809 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
10810 below.) Operating system declarations should always contain at least
10814 @defvr {Scheme Variable} %pseudo-terminal-file-system
10815 This is the file system to be mounted as @file{/dev/pts}. It supports
10816 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
10817 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
10818 Manual}). Pseudo-terminals are used by terminal emulators such as
10822 @defvr {Scheme Variable} %shared-memory-file-system
10823 This file system is mounted as @file{/dev/shm} and is used to support
10824 memory sharing across processes (@pxref{Memory-mapped I/O,
10825 @code{shm_open},, libc, The GNU C Library Reference Manual}).
10828 @defvr {Scheme Variable} %immutable-store
10829 This file system performs a read-only ``bind mount'' of
10830 @file{/gnu/store}, making it read-only for all the users including
10831 @code{root}. This prevents against accidental modification by software
10832 running as @code{root} or by system administrators.
10834 The daemon itself is still able to write to the store: it remounts it
10835 read-write in its own ``name space.''
10838 @defvr {Scheme Variable} %binary-format-file-system
10839 The @code{binfmt_misc} file system, which allows handling of arbitrary
10840 executable file types to be delegated to user space. This requires the
10841 @code{binfmt.ko} kernel module to be loaded.
10844 @defvr {Scheme Variable} %fuse-control-file-system
10845 The @code{fusectl} file system, which allows unprivileged users to mount
10846 and unmount user-space FUSE file systems. This requires the
10847 @code{fuse.ko} kernel module to be loaded.
10850 @node Mapped Devices
10851 @section Mapped Devices
10853 @cindex device mapping
10854 @cindex mapped devices
10855 The Linux kernel has a notion of @dfn{device mapping}: a block device,
10856 such as a hard disk partition, can be @dfn{mapped} into another device,
10857 usually in @code{/dev/mapper/},
10858 with additional processing over the data that flows through
10859 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
10860 concept of a ``mapped device'' and that of a file system: both boil down
10861 to @emph{translating} input/output operations made on a file to
10862 operations on its backing store. Thus, the Hurd implements mapped
10863 devices, like file systems, using the generic @dfn{translator} mechanism
10864 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
10865 typical example is encryption device mapping: all writes to the mapped
10866 device are encrypted, and all reads are deciphered, transparently.
10867 Guix extends this notion by considering any device or set of devices that
10868 are @dfn{transformed} in some way to create a new device; for instance,
10869 RAID devices are obtained by @dfn{assembling} several other devices, such
10870 as hard disks or partitions, into a new one that behaves as one partition.
10871 Other examples, not yet implemented, are LVM logical volumes.
10873 Mapped devices are declared using the @code{mapped-device} form,
10874 defined as follows; for examples, see below.
10876 @deftp {Data Type} mapped-device
10877 Objects of this type represent device mappings that will be made when
10878 the system boots up.
10882 This is either a string specifying the name of the block device to be mapped,
10883 such as @code{"/dev/sda3"}, or a list of such strings when several devices
10884 need to be assembled for creating a new one.
10887 This string specifies the name of the resulting mapped device. For
10888 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
10889 specifying @code{"my-partition"} leads to the creation of
10890 the @code{"/dev/mapper/my-partition"} device.
10891 For RAID devices of type @code{raid-device-mapping}, the full device name
10892 such as @code{"/dev/md0"} needs to be given.
10895 This must be a @code{mapped-device-kind} object, which specifies how
10896 @var{source} is mapped to @var{target}.
10900 @defvr {Scheme Variable} luks-device-mapping
10901 This defines LUKS block device encryption using the @command{cryptsetup}
10902 command from the package with the same name. It relies on the
10903 @code{dm-crypt} Linux kernel module.
10906 @defvr {Scheme Variable} raid-device-mapping
10907 This defines a RAID device, which is assembled using the @code{mdadm}
10908 command from the package with the same name. It requires a Linux kernel
10909 module for the appropriate RAID level to be loaded, such as @code{raid456}
10910 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
10913 @cindex disk encryption
10915 The following example specifies a mapping from @file{/dev/sda3} to
10916 @file{/dev/mapper/home} using LUKS---the
10917 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
10918 standard mechanism for disk encryption.
10919 The @file{/dev/mapper/home}
10920 device can then be used as the @code{device} of a @code{file-system}
10921 declaration (@pxref{File Systems}).
10925 (source "/dev/sda3")
10927 (type luks-device-mapping))
10930 Alternatively, to become independent of device numbering, one may obtain
10931 the LUKS UUID (@dfn{unique identifier}) of the source device by a
10935 cryptsetup luksUUID /dev/sda3
10938 and use it as follows:
10942 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
10944 (type luks-device-mapping))
10947 @cindex swap encryption
10948 It is also desirable to encrypt swap space, since swap space may contain
10949 sensitive data. One way to accomplish that is to use a swap file in a
10950 file system on a device mapped via LUKS encryption. In this way, the
10951 swap file is encrypted because the entire device is encrypted.
10952 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
10954 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
10955 may be declared as follows:
10959 (source (list "/dev/sda1" "/dev/sdb1"))
10960 (target "/dev/md0")
10961 (type raid-device-mapping))
10964 The @file{/dev/md0} device can then be used as the @code{device} of a
10965 @code{file-system} declaration (@pxref{File Systems}).
10966 Note that the RAID level need not be given; it is chosen during the
10967 initial creation and formatting of the RAID device and is determined
10968 automatically later.
10971 @node User Accounts
10972 @section User Accounts
10976 @cindex user accounts
10977 User accounts and groups are entirely managed through the
10978 @code{operating-system} declaration. They are specified with the
10979 @code{user-account} and @code{user-group} forms:
10985 (supplementary-groups '("wheel" ;allow use of sudo, etc.
10986 "audio" ;sound card
10987 "video" ;video devices such as webcams
10988 "cdrom")) ;the good ol' CD-ROM
10989 (comment "Bob's sister")
10990 (home-directory "/home/alice"))
10993 When booting or upon completion of @command{guix system reconfigure},
10994 the system ensures that only the user accounts and groups specified in
10995 the @code{operating-system} declaration exist, and with the specified
10996 properties. Thus, account or group creations or modifications made by
10997 directly invoking commands such as @command{useradd} are lost upon
10998 reconfiguration or reboot. This ensures that the system remains exactly
11001 @deftp {Data Type} user-account
11002 Objects of this type represent user accounts. The following members may
11007 The name of the user account.
11011 This is the name (a string) or identifier (a number) of the user group
11012 this account belongs to.
11014 @item @code{supplementary-groups} (default: @code{'()})
11015 Optionally, this can be defined as a list of group names that this
11016 account belongs to.
11018 @item @code{uid} (default: @code{#f})
11019 This is the user ID for this account (a number), or @code{#f}. In the
11020 latter case, a number is automatically chosen by the system when the
11021 account is created.
11023 @item @code{comment} (default: @code{""})
11024 A comment about the account, such as the account owner's full name.
11026 @item @code{home-directory}
11027 This is the name of the home directory for the account.
11029 @item @code{create-home-directory?} (default: @code{#t})
11030 Indicates whether the home directory of this account should be created
11031 if it does not exist yet.
11033 @item @code{shell} (default: Bash)
11034 This is a G-expression denoting the file name of a program to be used as
11035 the shell (@pxref{G-Expressions}).
11037 @item @code{system?} (default: @code{#f})
11038 This Boolean value indicates whether the account is a ``system''
11039 account. System accounts are sometimes treated specially; for instance,
11040 graphical login managers do not list them.
11042 @anchor{user-account-password}
11043 @cindex password, for user accounts
11044 @item @code{password} (default: @code{#f})
11045 You would normally leave this field to @code{#f}, initialize user
11046 passwords as @code{root} with the @command{passwd} command, and then let
11047 users change it with @command{passwd}. Passwords set with
11048 @command{passwd} are of course preserved across reboot and
11051 If you @emph{do} want to set an initial password for an account, then
11052 this field must contain the encrypted password, as a string. You can use the
11053 @code{crypt} procedure for this purpose:
11060 ;; Specify a SHA-512-hashed initial password.
11061 (password (crypt "InitialPassword!" "$6$abc")))
11065 The hash of this initial password will be available in a file in
11066 @file{/gnu/store}, readable by all the users, so this method must be used with
11070 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
11071 more information on password encryption, and @ref{Encryption,,, guile, GNU
11072 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
11078 User group declarations are even simpler:
11081 (user-group (name "students"))
11084 @deftp {Data Type} user-group
11085 This type is for, well, user groups. There are just a few fields:
11089 The name of the group.
11091 @item @code{id} (default: @code{#f})
11092 The group identifier (a number). If @code{#f}, a new number is
11093 automatically allocated when the group is created.
11095 @item @code{system?} (default: @code{#f})
11096 This Boolean value indicates whether the group is a ``system'' group.
11097 System groups have low numerical IDs.
11099 @item @code{password} (default: @code{#f})
11100 What, user groups can have a password? Well, apparently yes. Unless
11101 @code{#f}, this field specifies the password of the group.
11106 For convenience, a variable lists all the basic user groups one may
11109 @defvr {Scheme Variable} %base-groups
11110 This is the list of basic user groups that users and/or packages expect
11111 to be present on the system. This includes groups such as ``root'',
11112 ``wheel'', and ``users'', as well as groups used to control access to
11113 specific devices such as ``audio'', ``disk'', and ``cdrom''.
11116 @defvr {Scheme Variable} %base-user-accounts
11117 This is the list of basic system accounts that programs may expect to
11118 find on a GNU/Linux system, such as the ``nobody'' account.
11120 Note that the ``root'' account is not included here. It is a
11121 special-case and is automatically added whether or not it is specified.
11124 @node Keyboard Layout
11125 @section Keyboard Layout
11127 @cindex keyboard layout
11129 To specify what each key of your keyboard does, you need to tell the operating
11130 system what @dfn{keyboard layout} you want to use. The default, when nothing
11131 is specified, is the US English QWERTY layout for 105-key PC keyboards.
11132 However, German speakers will usually prefer the German QWERTZ layout, French
11133 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
11134 or bépo, and they might even want to further customize the effect of some of
11135 the keys. This section explains how to get that done.
11137 @cindex keyboard layout, definition
11138 There are three components that will want to know about your keyboard layout:
11142 The @emph{bootloader} may want to know what keyboard layout you want to use
11143 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
11144 you want, for instance, to make sure that you can type the passphrase of your
11145 encrypted root partition using the right layout.
11148 The @emph{operating system kernel}, Linux, will need that so that the console
11149 is properly configured (@pxref{operating-system Reference,
11150 @code{keyboard-layout}}).
11153 The @emph{graphical display server}, usually Xorg, also has its own idea of
11154 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
11157 Guix allows you to configure all three separately but, fortunately, it allows
11158 you to share the same keyboard layout for all three components.
11160 @cindex XKB, keyboard layouts
11161 Keyboard layouts are represented by records created by the
11162 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
11163 the X Keyboard extension (XKB), each layout has four attributes: a name (often
11164 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
11165 optional variant name, an optional keyboard model name, and a possibly empty
11166 list of additional options. In most cases the layout name is all you care
11167 about. Here are a few example:
11170 ;; The German QWERTZ layout. Here we assume a standard
11171 ;; "pc105" keyboard model.
11172 (keyboard-layout "de")
11174 ;; The bépo variant of the French layout.
11175 (keyboard-layout "fr" "bepo")
11177 ;; The Catalan layout.
11178 (keyboard-layout "es" "cat")
11180 ;; The Latin American Spanish layout. In addition, the
11181 ;; "Caps Lock" key is used as an additional "Ctrl" key,
11182 ;; and the "Menu" key is used as a "Compose" key to enter
11183 ;; accented letters.
11184 (keyboard-layout "latam"
11185 #:options '("ctrl:nocaps" "compose:menu"))
11187 ;; The Russian layout for a ThinkPad keyboard.
11188 (keyboard-layout "ru" #:model "thinkpad")
11190 ;; The "US international" layout, which is the US layout plus
11191 ;; dead keys to enter accented characters. This is for an
11192 ;; Apple MacBook keyboard.
11193 (keyboard-layout "us" "intl" #:model "macbook78")
11196 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
11197 for a complete list of supported layouts, variants, and models.
11199 @cindex keyboard layout, configuration
11200 Let's say you want your system to use the Turkish keyboard layout throughout
11201 your system---bootloader, console, and Xorg. Here's what your system
11202 configuration would look like:
11204 @findex set-xorg-configuration
11206 ;; Using the Turkish layout for the bootloader, the console,
11211 (keyboard-layout (keyboard-layout "tr")) ;for the console
11212 (bootloader (bootloader-configuration
11213 (bootloader grub-efi-bootloader)
11214 (target "/boot/efi")
11215 (keyboard-layout keyboard-layout))) ;for GRUB
11216 (services (cons (set-xorg-configuration
11217 (xorg-configuration ;for Xorg
11218 (keyboard-layout keyboard-layout)))
11219 %desktop-services)))
11222 In the example above, for GRUB and for Xorg, we just refer to the
11223 @code{keyboard-layout} field defined above, but we could just as well refer to
11224 a different layout. The @code{set-xorg-configuration} procedure communicates
11225 the desired Xorg configuration to the graphical log-in manager, by default
11228 We've discussed how to specify the @emph{default} keyboard layout of your
11229 system when it starts, but you can also adjust it at run time:
11233 If you're using GNOME, its settings panel has a ``Region & Language'' entry
11234 where you can select one or more keyboard layouts.
11237 Under Xorg, the @command{setxkbmap} command (from the same-named package)
11238 allows you to change the current layout. For example, this is how you would
11239 change the layout to US Dvorak:
11242 setxkbmap us dvorak
11246 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
11247 console. However, note that @code{loadkeys} does @emph{not} use the XKB
11248 keyboard layout categorization described above. The command below loads the
11249 French bépo layout:
11260 A @dfn{locale} defines cultural conventions for a particular language
11261 and region of the world (@pxref{Locales,,, libc, The GNU C Library
11262 Reference Manual}). Each locale has a name that typically has the form
11263 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
11264 @code{fr_LU.utf8} designates the locale for the French language, with
11265 cultural conventions from Luxembourg, and using the UTF-8 encoding.
11267 @cindex locale definition
11268 Usually, you will want to specify the default locale for the machine
11269 using the @code{locale} field of the @code{operating-system} declaration
11270 (@pxref{operating-system Reference, @code{locale}}).
11272 The selected locale is automatically added to the @dfn{locale
11273 definitions} known to the system if needed, with its codeset inferred
11274 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
11275 @code{UTF-8} codeset. Additional locale definitions can be specified in
11276 the @code{locale-definitions} slot of @code{operating-system}---this is
11277 useful, for instance, if the codeset could not be inferred from the
11278 locale name. The default set of locale definitions includes some widely
11279 used locales, but not all the available locales, in order to save space.
11281 For instance, to add the North Frisian locale for Germany, the value of
11285 (cons (locale-definition
11286 (name "fy_DE.utf8") (source "fy_DE"))
11287 %default-locale-definitions)
11290 Likewise, to save space, one might want @code{locale-definitions} to
11291 list only the locales that are actually used, as in:
11294 (list (locale-definition
11295 (name "ja_JP.eucjp") (source "ja_JP")
11296 (charset "EUC-JP")))
11300 The compiled locale definitions are available at
11301 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
11302 version, which is the default location where the GNU@tie{}libc provided
11303 by Guix looks for locale data. This can be overridden using the
11304 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
11305 @code{LOCPATH} and locale packages}).
11307 The @code{locale-definition} form is provided by the @code{(gnu system
11308 locale)} module. Details are given below.
11310 @deftp {Data Type} locale-definition
11311 This is the data type of a locale definition.
11316 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
11317 Reference Manual}, for more information on locale names.
11319 @item @code{source}
11320 The name of the source for that locale. This is typically the
11321 @code{@var{language}_@var{territory}} part of the locale name.
11323 @item @code{charset} (default: @code{"UTF-8"})
11324 The ``character set'' or ``code set'' for that locale,
11325 @uref{https://www.iana.org/assignments/character-sets, as defined by
11331 @defvr {Scheme Variable} %default-locale-definitions
11332 A list of commonly used UTF-8 locales, used as the default
11333 value of the @code{locale-definitions} field of @code{operating-system}
11336 @cindex locale name
11337 @cindex normalized codeset in locale names
11338 These locale definitions use the @dfn{normalized codeset} for the part
11339 that follows the dot in the name (@pxref{Using gettextized software,
11340 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
11341 instance it has @code{uk_UA.utf8} but @emph{not}, say,
11342 @code{uk_UA.UTF-8}.
11345 @subsection Locale Data Compatibility Considerations
11347 @cindex incompatibility, of locale data
11348 @code{operating-system} declarations provide a @code{locale-libcs} field
11349 to specify the GNU@tie{}libc packages that are used to compile locale
11350 declarations (@pxref{operating-system Reference}). ``Why would I
11351 care?'', you may ask. Well, it turns out that the binary format of
11352 locale data is occasionally incompatible from one libc version to
11355 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
11356 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
11357 For instance, a program linked against libc version 2.21 is unable to
11358 read locale data produced with libc 2.22; worse, that program
11359 @emph{aborts} instead of simply ignoring the incompatible locale
11360 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
11361 the incompatible locale data, which is already an improvement.}.
11362 Similarly, a program linked against libc 2.22 can read most, but not
11363 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
11364 data is incompatible); thus calls to @code{setlocale} may fail, but
11365 programs will not abort.
11367 The ``problem'' with Guix is that users have a lot of freedom: They can
11368 choose whether and when to upgrade software in their profiles, and might
11369 be using a libc version different from the one the system administrator
11370 used to build the system-wide locale data.
11372 Fortunately, unprivileged users can also install their own locale data
11373 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
11374 @code{GUIX_LOCPATH} and locale packages}).
11376 Still, it is best if the system-wide locale data at
11377 @file{/run/current-system/locale} is built for all the libc versions
11378 actually in use on the system, so that all the programs can access
11379 it---this is especially crucial on a multi-user system. To do that, the
11380 administrator can specify several libc packages in the
11381 @code{locale-libcs} field of @code{operating-system}:
11384 (use-package-modules base)
11388 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
11391 This example would lead to a system containing locale definitions for
11392 both libc 2.21 and the current version of libc in
11393 @file{/run/current-system/locale}.
11399 @cindex system services
11400 An important part of preparing an @code{operating-system} declaration is
11401 listing @dfn{system services} and their configuration (@pxref{Using the
11402 Configuration System}). System services are typically daemons launched
11403 when the system boots, or other actions needed at that time---e.g.,
11404 configuring network access.
11406 Guix has a broad definition of ``service'' (@pxref{Service
11407 Composition}), but many services are managed by the GNU@tie{}Shepherd
11408 (@pxref{Shepherd Services}). On a running system, the @command{herd}
11409 command allows you to list the available services, show their status,
11410 start and stop them, or do other specific operations (@pxref{Jump
11411 Start,,, shepherd, The GNU Shepherd Manual}). For example:
11417 The above command, run as @code{root}, lists the currently defined
11418 services. The @command{herd doc} command shows a synopsis of the given
11419 service and its associated actions:
11423 Run libc's name service cache daemon (nscd).
11425 # herd doc nscd action invalidate
11426 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
11429 The @command{start}, @command{stop}, and @command{restart} sub-commands
11430 have the effect you would expect. For instance, the commands below stop
11431 the nscd service and restart the Xorg display server:
11435 Service nscd has been stopped.
11436 # herd restart xorg-server
11437 Service xorg-server has been stopped.
11438 Service xorg-server has been started.
11441 The following sections document the available services, starting with
11442 the core services, that may be used in an @code{operating-system}
11446 * Base Services:: Essential system services.
11447 * Scheduled Job Execution:: The mcron service.
11448 * Log Rotation:: The rottlog service.
11449 * Networking Services:: Network setup, SSH daemon, etc.
11450 * X Window:: Graphical display.
11451 * Printing Services:: Local and remote printer support.
11452 * Desktop Services:: D-Bus and desktop services.
11453 * Sound Services:: ALSA and Pulseaudio services.
11454 * Database Services:: SQL databases, key-value stores, etc.
11455 * Mail Services:: IMAP, POP3, SMTP, and all that.
11456 * Messaging Services:: Messaging services.
11457 * Telephony Services:: Telephony services.
11458 * Monitoring Services:: Monitoring services.
11459 * Kerberos Services:: Kerberos services.
11460 * LDAP Services:: LDAP services.
11461 * Web Services:: Web servers.
11462 * Certificate Services:: TLS certificates via Let's Encrypt.
11463 * DNS Services:: DNS daemons.
11464 * VPN Services:: VPN daemons.
11465 * Network File System:: NFS related services.
11466 * Continuous Integration:: The Cuirass service.
11467 * Power Management Services:: Extending battery life.
11468 * Audio Services:: The MPD.
11469 * Virtualization Services:: Virtualization services.
11470 * Version Control Services:: Providing remote access to Git repositories.
11471 * Game Services:: Game servers.
11472 * Miscellaneous Services:: Other services.
11475 @node Base Services
11476 @subsection Base Services
11478 The @code{(gnu services base)} module provides definitions for the basic
11479 services that one expects from the system. The services exported by
11480 this module are listed below.
11482 @defvr {Scheme Variable} %base-services
11483 This variable contains a list of basic services (@pxref{Service Types
11484 and Services}, for more information on service objects) one would
11485 expect from the system: a login service (mingetty) on each tty, syslogd,
11486 the libc name service cache daemon (nscd), the udev device manager, and
11489 This is the default value of the @code{services} field of
11490 @code{operating-system} declarations. Usually, when customizing a
11491 system, you will want to append services to @var{%base-services}, like
11495 (append (list (service avahi-service-type)
11496 (service openssh-service-type))
11501 @defvr {Scheme Variable} special-files-service-type
11502 This is the service that sets up ``special files'' such as
11503 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
11505 The value associated with @code{special-files-service-type} services
11506 must be a list of tuples where the first element is the ``special file''
11507 and the second element is its target. By default it is:
11509 @cindex @file{/bin/sh}
11510 @cindex @file{sh}, in @file{/bin}
11512 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
11515 @cindex @file{/usr/bin/env}
11516 @cindex @file{env}, in @file{/usr/bin}
11517 If you want to add, say, @code{/usr/bin/env} to your system, you can
11521 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
11522 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
11525 Since this is part of @code{%base-services}, you can use
11526 @code{modify-services} to customize the set of special files
11527 (@pxref{Service Reference, @code{modify-services}}). But the simple way
11528 to add a special file is @i{via} the @code{extra-special-file} procedure
11532 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
11533 Use @var{target} as the ``special file'' @var{file}.
11535 For example, adding the following lines to the @code{services} field of
11536 your operating system declaration leads to a @file{/usr/bin/env}
11540 (extra-special-file "/usr/bin/env"
11541 (file-append coreutils "/bin/env"))
11545 @deffn {Scheme Procedure} host-name-service @var{name}
11546 Return a service that sets the host name to @var{name}.
11549 @deffn {Scheme Procedure} login-service @var{config}
11550 Return a service to run login according to @var{config}, a
11551 @code{<login-configuration>} object, which specifies the message of the day,
11552 among other things.
11555 @deftp {Data Type} login-configuration
11556 This is the data type representing the configuration of login.
11561 @cindex message of the day
11562 A file-like object containing the ``message of the day''.
11564 @item @code{allow-empty-passwords?} (default: @code{#t})
11565 Allow empty passwords by default so that first-time users can log in when
11566 the 'root' account has just been created.
11571 @deffn {Scheme Procedure} mingetty-service @var{config}
11572 Return a service to run mingetty according to @var{config}, a
11573 @code{<mingetty-configuration>} object, which specifies the tty to run, among
11577 @deftp {Data Type} mingetty-configuration
11578 This is the data type representing the configuration of Mingetty, which
11579 provides the default implementation of virtual console log-in.
11584 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
11586 @item @code{auto-login} (default: @code{#f})
11587 When true, this field must be a string denoting the user name under
11588 which the system automatically logs in. When it is @code{#f}, a
11589 user name and password must be entered to log in.
11591 @item @code{login-program} (default: @code{#f})
11592 This must be either @code{#f}, in which case the default log-in program
11593 is used (@command{login} from the Shadow tool suite), or a gexp denoting
11594 the name of the log-in program.
11596 @item @code{login-pause?} (default: @code{#f})
11597 When set to @code{#t} in conjunction with @var{auto-login}, the user
11598 will have to press a key before the log-in shell is launched.
11600 @item @code{mingetty} (default: @var{mingetty})
11601 The Mingetty package to use.
11606 @deffn {Scheme Procedure} agetty-service @var{config}
11607 Return a service to run agetty according to @var{config}, an
11608 @code{<agetty-configuration>} object, which specifies the tty to run,
11609 among other things.
11612 @deftp {Data Type} agetty-configuration
11613 This is the data type representing the configuration of agetty, which
11614 implements virtual and serial console log-in. See the @code{agetty(8)}
11615 man page for more information.
11620 The name of the console this agetty runs on, as a string---e.g.,
11621 @code{"ttyS0"}. This argument is optional, it will default to
11622 a reasonable default serial port used by the kernel Linux.
11624 For this, if there is a value for an option @code{agetty.tty} in the kernel
11625 command line, agetty will extract the device name of the serial port
11626 from it and use that.
11628 If not and if there is a value for an option @code{console} with a tty in
11629 the Linux command line, agetty will extract the device name of the
11630 serial port from it and use that.
11632 In both cases, agetty will leave the other serial device settings
11633 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
11636 @item @code{baud-rate} (default: @code{#f})
11637 A string containing a comma-separated list of one or more baud rates, in
11640 @item @code{term} (default: @code{#f})
11641 A string containing the value used for the @code{TERM} environment
11644 @item @code{eight-bits?} (default: @code{#f})
11645 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
11648 @item @code{auto-login} (default: @code{#f})
11649 When passed a login name, as a string, the specified user will be logged
11650 in automatically without prompting for their login name or password.
11652 @item @code{no-reset?} (default: @code{#f})
11653 When @code{#t}, don't reset terminal cflags (control modes).
11655 @item @code{host} (default: @code{#f})
11656 This accepts a string containing the "login_host", which will be written
11657 into the @file{/var/run/utmpx} file.
11659 @item @code{remote?} (default: @code{#f})
11660 When set to @code{#t} in conjunction with @var{host}, this will add an
11661 @code{-r} fakehost option to the command line of the login program
11662 specified in @var{login-program}.
11664 @item @code{flow-control?} (default: @code{#f})
11665 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
11667 @item @code{no-issue?} (default: @code{#f})
11668 When set to @code{#t}, the contents of the @file{/etc/issue} file will
11669 not be displayed before presenting the login prompt.
11671 @item @code{init-string} (default: @code{#f})
11672 This accepts a string that will be sent to the tty or modem before
11673 sending anything else. It can be used to initialize a modem.
11675 @item @code{no-clear?} (default: @code{#f})
11676 When set to @code{#t}, agetty will not clear the screen before showing
11679 @item @code{login-program} (default: (file-append shadow "/bin/login"))
11680 This must be either a gexp denoting the name of a log-in program, or
11681 unset, in which case the default value is the @command{login} from the
11684 @item @code{local-line} (default: @code{#f})
11685 Control the CLOCAL line flag. This accepts one of three symbols as
11686 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
11687 the default value chosen by agetty is @code{'auto}.
11689 @item @code{extract-baud?} (default: @code{#f})
11690 When set to @code{#t}, instruct agetty to try to extract the baud rate
11691 from the status messages produced by certain types of modems.
11693 @item @code{skip-login?} (default: @code{#f})
11694 When set to @code{#t}, do not prompt the user for a login name. This
11695 can be used with @var{login-program} field to use non-standard login
11698 @item @code{no-newline?} (default: @code{#f})
11699 When set to @code{#t}, do not print a newline before printing the
11700 @file{/etc/issue} file.
11702 @c Is this dangerous only when used with login-program, or always?
11703 @item @code{login-options} (default: @code{#f})
11704 This option accepts a string containing options that are passed to the
11705 login program. When used with the @var{login-program}, be aware that a
11706 malicious user could try to enter a login name containing embedded
11707 options that could be parsed by the login program.
11709 @item @code{login-pause} (default: @code{#f})
11710 When set to @code{#t}, wait for any key before showing the login prompt.
11711 This can be used in conjunction with @var{auto-login} to save memory by
11712 lazily spawning shells.
11714 @item @code{chroot} (default: @code{#f})
11715 Change root to the specified directory. This option accepts a directory
11718 @item @code{hangup?} (default: @code{#f})
11719 Use the Linux system call @code{vhangup} to do a virtual hangup of the
11720 specified terminal.
11722 @item @code{keep-baud?} (default: @code{#f})
11723 When set to @code{#t}, try to keep the existing baud rate. The baud
11724 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
11727 @item @code{timeout} (default: @code{#f})
11728 When set to an integer value, terminate if no user name could be read
11729 within @var{timeout} seconds.
11731 @item @code{detect-case?} (default: @code{#f})
11732 When set to @code{#t}, turn on support for detecting an uppercase-only
11733 terminal. This setting will detect a login name containing only
11734 uppercase letters as indicating an uppercase-only terminal and turn on
11735 some upper-to-lower case conversions. Note that this will not support
11736 Unicode characters.
11738 @item @code{wait-cr?} (default: @code{#f})
11739 When set to @code{#t}, wait for the user or modem to send a
11740 carriage-return or linefeed character before displaying
11741 @file{/etc/issue} or login prompt. This is typically used with the
11742 @var{init-string} option.
11744 @item @code{no-hints?} (default: @code{#f})
11745 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
11748 @item @code{no-hostname?} (default: @code{#f})
11749 By default, the hostname is printed. When this option is set to
11750 @code{#t}, no hostname will be shown at all.
11752 @item @code{long-hostname?} (default: @code{#f})
11753 By default, the hostname is only printed until the first dot. When this
11754 option is set to @code{#t}, the fully qualified hostname by
11755 @code{gethostname} or @code{getaddrinfo} is shown.
11757 @item @code{erase-characters} (default: @code{#f})
11758 This option accepts a string of additional characters that should be
11759 interpreted as backspace when the user types their login name.
11761 @item @code{kill-characters} (default: @code{#f})
11762 This option accepts a string that should be interpreted to mean "ignore
11763 all previous characters" (also called a "kill" character) when the user
11764 types their login name.
11766 @item @code{chdir} (default: @code{#f})
11767 This option accepts, as a string, a directory path that will be changed
11770 @item @code{delay} (default: @code{#f})
11771 This options accepts, as an integer, the number of seconds to sleep
11772 before opening the tty and displaying the login prompt.
11774 @item @code{nice} (default: @code{#f})
11775 This option accepts, as an integer, the nice value with which to run the
11776 @command{login} program.
11778 @item @code{extra-options} (default: @code{'()})
11779 This option provides an "escape hatch" for the user to provide arbitrary
11780 command-line arguments to @command{agetty} as a list of strings.
11785 @deffn {Scheme Procedure} kmscon-service-type @var{config}
11786 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
11787 according to @var{config}, a @code{<kmscon-configuration>} object, which
11788 specifies the tty to run, among other things.
11791 @deftp {Data Type} kmscon-configuration
11792 This is the data type representing the configuration of Kmscon, which
11793 implements virtual console log-in.
11797 @item @code{virtual-terminal}
11798 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
11800 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
11801 A gexp denoting the name of the log-in program. The default log-in program is
11802 @command{login} from the Shadow tool suite.
11804 @item @code{login-arguments} (default: @code{'("-p")})
11805 A list of arguments to pass to @command{login}.
11807 @item @code{auto-login} (default: @code{#f})
11808 When passed a login name, as a string, the specified user will be logged
11809 in automatically without prompting for their login name or password.
11811 @item @code{hardware-acceleration?} (default: #f)
11812 Whether to use hardware acceleration.
11814 @item @code{kmscon} (default: @var{kmscon})
11815 The Kmscon package to use.
11820 @cindex name service cache daemon
11822 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
11823 [#:name-services '()]
11824 Return a service that runs the libc name service cache daemon (nscd) with the
11825 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
11826 Service Switch}, for an example.
11828 For convenience, the Shepherd service for nscd provides the following actions:
11832 @cindex cache invalidation, nscd
11833 @cindex nscd, cache invalidation
11834 This invalidate the given cache. For instance, running:
11837 herd invalidate nscd hosts
11841 invalidates the host name lookup cache of nscd.
11844 Running @command{herd statistics nscd} displays information about nscd usage
11850 @defvr {Scheme Variable} %nscd-default-configuration
11851 This is the default @code{<nscd-configuration>} value (see below) used
11852 by @code{nscd-service}. It uses the caches defined by
11853 @var{%nscd-default-caches}; see below.
11856 @deftp {Data Type} nscd-configuration
11857 This is the data type representing the name service cache daemon (nscd)
11862 @item @code{name-services} (default: @code{'()})
11863 List of packages denoting @dfn{name services} that must be visible to
11864 the nscd---e.g., @code{(list @var{nss-mdns})}.
11866 @item @code{glibc} (default: @var{glibc})
11867 Package object denoting the GNU C Library providing the @command{nscd}
11870 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
11871 Name of the nscd log file. This is where debugging output goes when
11872 @code{debug-level} is strictly positive.
11874 @item @code{debug-level} (default: @code{0})
11875 Integer denoting the debugging levels. Higher numbers mean that more
11876 debugging output is logged.
11878 @item @code{caches} (default: @var{%nscd-default-caches})
11879 List of @code{<nscd-cache>} objects denoting things to be cached; see
11885 @deftp {Data Type} nscd-cache
11886 Data type representing a cache database of nscd and its parameters.
11890 @item @code{database}
11891 This is a symbol representing the name of the database to be cached.
11892 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
11893 @code{services}, which designate the corresponding NSS database
11894 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
11896 @item @code{positive-time-to-live}
11897 @itemx @code{negative-time-to-live} (default: @code{20})
11898 A number representing the number of seconds during which a positive or
11899 negative lookup result remains in cache.
11901 @item @code{check-files?} (default: @code{#t})
11902 Whether to check for updates of the files corresponding to
11905 For instance, when @var{database} is @code{hosts}, setting this flag
11906 instructs nscd to check for updates in @file{/etc/hosts} and to take
11909 @item @code{persistent?} (default: @code{#t})
11910 Whether the cache should be stored persistently on disk.
11912 @item @code{shared?} (default: @code{#t})
11913 Whether the cache should be shared among users.
11915 @item @code{max-database-size} (default: 32@tie{}MiB)
11916 Maximum size in bytes of the database cache.
11918 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
11919 @c settings, so leave them out.
11924 @defvr {Scheme Variable} %nscd-default-caches
11925 List of @code{<nscd-cache>} objects used by default by
11926 @code{nscd-configuration} (see above).
11928 It enables persistent and aggressive caching of service and host name
11929 lookups. The latter provides better host name lookup performance,
11930 resilience in the face of unreliable name servers, and also better
11931 privacy---often the result of host name lookups is in local cache, so
11932 external name servers do not even need to be queried.
11935 @anchor{syslog-configuration-type}
11938 @deftp {Data Type} syslog-configuration
11939 This data type represents the configuration of the syslog daemon.
11942 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
11943 The syslog daemon to use.
11945 @item @code{config-file} (default: @code{%default-syslog.conf})
11946 The syslog configuration file to use.
11951 @anchor{syslog-service}
11953 @deffn {Scheme Procedure} syslog-service @var{config}
11954 Return a service that runs a syslog daemon according to @var{config}.
11956 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
11957 information on the configuration file syntax.
11960 @defvr {Scheme Variable} guix-service-type
11961 This is the type of the service that runs the build daemon,
11962 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
11963 @code{guix-configuration} record as described below.
11966 @anchor{guix-configuration-type}
11967 @deftp {Data Type} guix-configuration
11968 This data type represents the configuration of the Guix build daemon.
11969 @xref{Invoking guix-daemon}, for more information.
11972 @item @code{guix} (default: @var{guix})
11973 The Guix package to use.
11975 @item @code{build-group} (default: @code{"guixbuild"})
11976 Name of the group for build user accounts.
11978 @item @code{build-accounts} (default: @code{10})
11979 Number of build user accounts to create.
11981 @item @code{authorize-key?} (default: @code{#t})
11982 @cindex substitutes, authorization thereof
11983 Whether to authorize the substitute keys listed in
11984 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
11985 (@pxref{Substitutes}).
11987 @vindex %default-authorized-guix-keys
11988 @item @code{authorized-keys} (default: @var{%default-authorized-guix-keys})
11989 The list of authorized key files for archive imports, as a list of
11990 string-valued gexps (@pxref{Invoking guix archive}). By default, it
11991 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
11993 @item @code{use-substitutes?} (default: @code{#t})
11994 Whether to use substitutes.
11996 @item @code{substitute-urls} (default: @var{%default-substitute-urls})
11997 The list of URLs where to look for substitutes by default.
11999 @item @code{max-silent-time} (default: @code{0})
12000 @itemx @code{timeout} (default: @code{0})
12001 The number of seconds of silence and the number of seconds of activity,
12002 respectively, after which a build process times out. A value of zero
12003 disables the timeout.
12005 @item @code{log-compression} (default: @code{'bzip2})
12006 The type of compression used for build logs---one of @code{gzip},
12007 @code{bzip2}, or @code{none}.
12009 @item @code{extra-options} (default: @code{'()})
12010 List of extra command-line options for @command{guix-daemon}.
12012 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
12013 File where @command{guix-daemon}'s standard output and standard error
12016 @item @code{http-proxy} (default: @code{#f})
12017 The HTTP proxy used for downloading fixed-output derivations and
12020 @item @code{tmpdir} (default: @code{#f})
12021 A directory path where the @command{guix-daemon} will perform builds.
12026 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
12027 Run @var{udev}, which populates the @file{/dev} directory dynamically.
12028 udev rules can be provided as a list of files through the @var{rules}
12029 variable. The procedures @code{udev-rule} and @code{file->udev-rule} from
12030 @code{(gnu services base)} simplify the creation of such rule files.
12033 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
12034 Return a udev-rule file named @var{file-name} containing the rules
12035 defined by the @var{contents} literal.
12037 In the following example, a rule for a USB device is defined to be
12038 stored in the file @file{90-usb-thing.rules}. The rule runs a script
12039 upon detecting a USB device with a given product identifier.
12042 (define %example-udev-rule
12044 "90-usb-thing.rules"
12045 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
12046 "ATTR@{product@}==\"Example\", "
12047 "RUN+=\"/path/to/script\"")))
12050 The @command{herd rules udev} command, as root, returns the name of the
12051 directory containing all the active udev rules.
12054 Here we show how the default @var{udev-service} can be extended with it.
12060 (modify-services %desktop-services
12061 (udev-service-type config =>
12062 (udev-configuration (inherit config)
12063 (rules (append (udev-configuration-rules config)
12064 (list %example-udev-rule))))))))
12067 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
12068 Return a udev file named @var{file-name} containing the rules defined
12069 within @var{file}, a file-like object.
12071 The following example showcases how we can use an existing rule file.
12074 (use-modules (guix download) ;for url-fetch
12075 (guix packages) ;for origin
12078 (define %android-udev-rules
12080 "51-android-udev.rules"
12081 (let ((version "20170910"))
12084 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
12085 "android-udev-rules/" version "/51-android.rules"))
12087 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
12091 Additionally, Guix package definitions can be included in @var{rules} in
12092 order to extend the udev rules with the definitions found under their
12093 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
12094 @var{file->udev-rule} example, we could have used the
12095 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
12096 packages android)} module.
12098 The following example shows how to use the @var{android-udev-rules}
12099 package so that the Android tool @command{adb} can detect devices
12100 without root privileges. It also details how to create the
12101 @code{adbusers} group, which is required for the proper functioning of
12102 the rules defined within the @var{android-udev-rules} package. To
12103 create such a group, we must define it both as part of the
12104 @var{supplementary-groups} of our @var{user-account} declaration, as
12105 well as in the @var{groups} field of the @var{operating-system} record.
12108 (use-modules (gnu packages android) ;for android-udev-rules
12109 (gnu system shadow) ;for user-group
12114 (users (cons (user-acount
12116 (supplementary-groups
12117 '("adbusers" ;for adb
12118 "wheel" "netdev" "audio" "video"))
12121 (groups (cons (user-group (system? #t) (name "adbusers"))
12127 (modify-services %desktop-services
12130 (udev-configuration (inherit config)
12131 (rules (cons android-udev-rules
12132 (udev-configuration-rules config))))))))
12135 @defvr {Scheme Variable} urandom-seed-service-type
12136 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
12137 when rebooting. It also tries to seed @file{/dev/urandom} from
12138 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
12142 @defvr {Scheme Variable} %random-seed-file
12143 This is the name of the file where some random bytes are saved by
12144 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
12145 It defaults to @file{/var/lib/random-seed}.
12150 @defvr {Scheme Variable} gpm-service-type
12151 This is the type of the service that runs GPM, the @dfn{general-purpose
12152 mouse daemon}, which provides mouse support to the Linux console. GPM
12153 allows users to use the mouse in the console, notably to select, copy,
12156 The value for services of this type must be a @code{gpm-configuration}
12157 (see below). This service is not part of @var{%base-services}.
12160 @deftp {Data Type} gpm-configuration
12161 Data type representing the configuration of GPM.
12164 @item @code{options} (default: @code{%default-gpm-options})
12165 Command-line options passed to @command{gpm}. The default set of
12166 options instruct @command{gpm} to listen to mouse events on
12167 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
12170 @item @code{gpm} (default: @code{gpm})
12171 The GPM package to use.
12176 @anchor{guix-publish-service-type}
12177 @deffn {Scheme Variable} guix-publish-service-type
12178 This is the service type for @command{guix publish} (@pxref{Invoking
12179 guix publish}). Its value must be a @code{guix-configuration}
12180 object, as described below.
12182 This assumes that @file{/etc/guix} already contains a signing key pair as
12183 created by @command{guix archive --generate-key} (@pxref{Invoking guix
12184 archive}). If that is not the case, the service will fail to start.
12187 @deftp {Data Type} guix-publish-configuration
12188 Data type representing the configuration of the @code{guix publish}
12192 @item @code{guix} (default: @code{guix})
12193 The Guix package to use.
12195 @item @code{port} (default: @code{80})
12196 The TCP port to listen for connections.
12198 @item @code{host} (default: @code{"localhost"})
12199 The host (and thus, network interface) to listen to. Use
12200 @code{"0.0.0.0"} to listen on all the network interfaces.
12202 @item @code{compression-level} (default: @code{3})
12203 The gzip compression level at which substitutes are compressed. Use
12204 @code{0} to disable compression altogether, and @code{9} to get the best
12205 compression ratio at the expense of increased CPU usage.
12207 @item @code{nar-path} (default: @code{"nar"})
12208 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
12209 publish, @code{--nar-path}}, for details.
12211 @item @code{cache} (default: @code{#f})
12212 When it is @code{#f}, disable caching and instead generate archives on
12213 demand. Otherwise, this should be the name of a directory---e.g.,
12214 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
12215 archives and meta-data ready to be sent. @xref{Invoking guix publish,
12216 @option{--cache}}, for more information on the tradeoffs involved.
12218 @item @code{workers} (default: @code{#f})
12219 When it is an integer, this is the number of worker threads used for
12220 caching; when @code{#f}, the number of processors is used.
12221 @xref{Invoking guix publish, @option{--workers}}, for more information.
12223 @item @code{ttl} (default: @code{#f})
12224 When it is an integer, this denotes the @dfn{time-to-live} in seconds
12225 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
12226 for more information.
12230 @anchor{rngd-service}
12231 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
12232 [#:device "/dev/hwrng"]
12233 Return a service that runs the @command{rngd} program from @var{rng-tools}
12234 to add @var{device} to the kernel's entropy pool. The service will fail if
12235 @var{device} does not exist.
12238 @anchor{pam-limits-service}
12239 @cindex session limits
12244 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
12246 Return a service that installs a configuration file for the
12247 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
12248 @code{pam_limits} module}. The procedure optionally takes a list of
12249 @code{pam-limits-entry} values, which can be used to specify
12250 @code{ulimit} limits and nice priority limits to user sessions.
12252 The following limits definition sets two hard and soft limits for all
12253 login sessions of users in the @code{realtime} group:
12256 (pam-limits-service
12258 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
12259 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
12262 The first entry increases the maximum realtime priority for
12263 non-privileged processes; the second entry lifts any restriction of the
12264 maximum address space that can be locked in memory. These settings are
12265 commonly used for real-time audio systems.
12268 @node Scheduled Job Execution
12269 @subsection Scheduled Job Execution
12273 @cindex scheduling jobs
12274 The @code{(gnu services mcron)} module provides an interface to
12275 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
12276 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
12277 Unix @command{cron} daemon; the main difference is that it is
12278 implemented in Guile Scheme, which provides a lot of flexibility when
12279 specifying the scheduling of jobs and their actions.
12281 The example below defines an operating system that runs the
12282 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
12283 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
12284 well as the @command{mkid} command on behalf of an unprivileged user
12285 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
12286 gexps to introduce job definitions that are passed to mcron
12287 (@pxref{G-Expressions}).
12290 (use-modules (guix) (gnu) (gnu services mcron))
12291 (use-package-modules base idutils)
12293 (define updatedb-job
12294 ;; Run 'updatedb' at 3AM every day. Here we write the
12295 ;; job's action as a Scheme procedure.
12296 #~(job '(next-hour '(3))
12298 (execl (string-append #$findutils "/bin/updatedb")
12300 "--prunepaths=/tmp /var/tmp /gnu/store"))))
12302 (define garbage-collector-job
12303 ;; Collect garbage 5 minutes after midnight every day.
12304 ;; The job's action is a shell command.
12305 #~(job "5 0 * * *" ;Vixie cron syntax
12308 (define idutils-job
12309 ;; Update the index database as user "charlie" at 12:15PM
12310 ;; and 19:15PM. This runs from the user's home directory.
12311 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
12312 (string-append #$idutils "/bin/mkid src")
12317 (services (cons (service mcron-service-type
12318 (mcron-configuration
12319 (jobs (list garbage-collector-job
12325 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
12326 for more information on mcron job specifications. Below is the
12327 reference of the mcron service.
12329 On a running system, you can use the @code{schedule} action of the service to
12330 visualize the mcron jobs that will be executed next:
12333 # herd schedule mcron
12337 The example above lists the next five tasks that will be executed, but you can
12338 also specify the number of tasks to display:
12341 # herd schedule mcron 10
12344 @defvr {Scheme Variable} mcron-service-type
12345 This is the type of the @code{mcron} service, whose value is an
12346 @code{mcron-configuration} object.
12348 This service type can be the target of a service extension that provides
12349 it additional job specifications (@pxref{Service Composition}). In
12350 other words, it is possible to define services that provide additional
12354 @deftp {Data Type} mcron-configuration
12355 Data type representing the configuration of mcron.
12358 @item @code{mcron} (default: @var{mcron})
12359 The mcron package to use.
12362 This is a list of gexps (@pxref{G-Expressions}), where each gexp
12363 corresponds to an mcron job specification (@pxref{Syntax, mcron job
12364 specifications,, mcron, GNU@tie{}mcron}).
12370 @subsection Log Rotation
12373 @cindex log rotation
12375 Log files such as those found in @file{/var/log} tend to grow endlessly,
12376 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
12377 their contents in separate files, possibly compressed. The @code{(gnu
12378 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
12379 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
12381 The example below defines an operating system that provides log rotation
12382 with the default settings, for commonly encountered log files.
12385 (use-modules (guix) (gnu))
12386 (use-service-modules admin mcron)
12387 (use-package-modules base idutils)
12391 (services (cons (service rottlog-service-type)
12395 @defvr {Scheme Variable} rottlog-service-type
12396 This is the type of the Rottlog service, whose value is a
12397 @code{rottlog-configuration} object.
12399 Other services can extend this one with new @code{log-rotation} objects
12400 (see below), thereby augmenting the set of files to be rotated.
12402 This service type can define mcron jobs (@pxref{Scheduled Job
12403 Execution}) to run the rottlog service.
12406 @deftp {Data Type} rottlog-configuration
12407 Data type representing the configuration of rottlog.
12410 @item @code{rottlog} (default: @code{rottlog})
12411 The Rottlog package to use.
12413 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
12414 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
12415 rottlog, GNU Rot[t]log Manual}).
12417 @item @code{rotations} (default: @code{%default-rotations})
12418 A list of @code{log-rotation} objects as defined below.
12421 This is a list of gexps where each gexp corresponds to an mcron job
12422 specification (@pxref{Scheduled Job Execution}).
12426 @deftp {Data Type} log-rotation
12427 Data type representing the rotation of a group of log files.
12429 Taking an example from the Rottlog manual (@pxref{Period Related File
12430 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
12436 (files '("/var/log/apache/*"))
12437 (options '("storedir apache-archives"
12443 The list of fields is as follows:
12446 @item @code{frequency} (default: @code{'weekly})
12447 The log rotation frequency, a symbol.
12450 The list of files or file glob patterns to rotate.
12452 @item @code{options} (default: @code{'()})
12453 The list of rottlog options for this rotation (@pxref{Configuration
12454 parameters,,, rottlog, GNU Rot[t]lg Manual}).
12456 @item @code{post-rotate} (default: @code{#f})
12457 Either @code{#f} or a gexp to execute once the rotation has completed.
12461 @defvr {Scheme Variable} %default-rotations
12462 Specifies weekly rotation of @var{%rotated-files} and
12463 a couple of other files.
12466 @defvr {Scheme Variable} %rotated-files
12467 The list of syslog-controlled files to be rotated. By default it is:
12468 @code{'("/var/log/messages" "/var/log/secure")}.
12471 @node Networking Services
12472 @subsection Networking Services
12474 The @code{(gnu services networking)} module provides services to configure
12475 the network interface.
12477 @cindex DHCP, networking service
12478 @defvr {Scheme Variable} dhcp-client-service-type
12479 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
12480 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
12481 is the DHCP client package to use, @code{isc-dhcp} by default.
12484 @deffn {Scheme Procedure} dhcpd-service-type
12485 This type defines a service that runs a DHCP daemon. To create a
12486 service of this type, you must supply a @code{<dhcpd-configuration>}.
12490 (service dhcpd-service-type
12491 (dhcpd-configuration
12492 (config-file (local-file "my-dhcpd.conf"))
12493 (interfaces '("enp0s25"))))
12497 @deftp {Data Type} dhcpd-configuration
12499 @item @code{package} (default: @code{isc-dhcp})
12500 The package that provides the DHCP daemon. This package is expected to
12501 provide the daemon at @file{sbin/dhcpd} relative to its output
12502 directory. The default package is the
12503 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
12504 @item @code{config-file} (default: @code{#f})
12505 The configuration file to use. This is required. It will be passed to
12506 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
12507 object (@pxref{G-Expressions, file-like objects}). See @code{man
12508 dhcpd.conf} for details on the configuration file syntax.
12509 @item @code{version} (default: @code{"4"})
12510 The DHCP version to use. The ISC DHCP server supports the values ``4'',
12511 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
12512 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
12514 @item @code{run-directory} (default: @code{"/run/dhcpd"})
12515 The run directory to use. At service activation time, this directory
12516 will be created if it does not exist.
12517 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
12518 The PID file to use. This corresponds to the @code{-pf} option of
12519 @code{dhcpd}. See @code{man dhcpd} for details.
12520 @item @code{interfaces} (default: @code{'()})
12521 The names of the network interfaces on which dhcpd should listen for
12522 broadcasts. If this list is not empty, then its elements (which must be
12523 strings) will be appended to the @code{dhcpd} invocation when starting
12524 the daemon. It may not be necessary to explicitly specify any
12525 interfaces here; see @code{man dhcpd} for details.
12529 @defvr {Scheme Variable} static-networking-service-type
12530 This is the type for statically-configured network interfaces.
12531 @c TODO Document <static-networking> data structures.
12534 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
12535 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
12536 [#:requirement @code{'(udev)}]
12537 Return a service that starts @var{interface} with address @var{ip}. If
12538 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
12539 it must be a string specifying the default network gateway. @var{requirement}
12540 can be used to declare a dependency on another service before configuring the
12543 This procedure can be called several times, one for each network
12544 interface of interest. Behind the scenes what it does is extend
12545 @code{static-networking-service-type} with additional network interfaces
12551 (static-networking-service "eno1" "192.168.1.82"
12552 #:gateway "192.168.1.2"
12553 #:name-servers '("192.168.1.2"))
12560 @cindex network management
12561 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
12562 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
12563 management daemon that aims to simplify wired and wireless networking.
12565 This service adds the @var{wicd} package to the global profile, providing
12566 several commands to interact with the daemon and configure networking:
12567 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
12568 and @command{wicd-curses} user interfaces.
12571 @cindex ModemManager
12573 @defvr {Scheme Variable} modem-manager-service-type
12574 This is the service type for the
12575 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
12576 service. The value for this service type is a
12577 @code{modem-manager-configuration} record.
12579 This service is part of @code{%desktop-services} (@pxref{Desktop
12583 @deftp {Data Type} modem-manager-configuration
12584 Data type representing the configuration of ModemManager.
12587 @item @code{modem-manager} (default: @code{modem-manager})
12588 The ModemManager package to use.
12593 @cindex NetworkManager
12595 @defvr {Scheme Variable} network-manager-service-type
12596 This is the service type for the
12597 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
12598 service. The value for this service type is a
12599 @code{network-manager-configuration} record.
12601 This service is part of @code{%desktop-services} (@pxref{Desktop
12605 @deftp {Data Type} network-manager-configuration
12606 Data type representing the configuration of NetworkManager.
12609 @item @code{network-manager} (default: @code{network-manager})
12610 The NetworkManager package to use.
12612 @item @code{dns} (default: @code{"default"})
12613 Processing mode for DNS, which affects how NetworkManager uses the
12614 @code{resolv.conf} configuration file.
12618 NetworkManager will update @code{resolv.conf} to reflect the nameservers
12619 provided by currently active connections.
12622 NetworkManager will run @code{dnsmasq} as a local caching nameserver,
12623 using a "split DNS" configuration if you are connected to a VPN, and
12624 then update @code{resolv.conf} to point to the local nameserver.
12627 NetworkManager will not modify @code{resolv.conf}.
12630 @item @code{vpn-plugins} (default: @code{'()})
12631 This is the list of available plugins for virtual private networks
12632 (VPNs). An example of this is the @code{network-manager-openvpn}
12633 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
12639 @deffn {Scheme Variable} connman-service-type
12640 This is the service type to run @url{https://01.org/connman,Connman},
12641 a network connection manager.
12643 Its value must be an
12644 @code{connman-configuration} record as in this example:
12647 (service connman-service-type
12648 (connman-configuration
12649 (disable-vpn? #t)))
12652 See below for details about @code{connman-configuration}.
12655 @deftp {Data Type} connman-configuration
12656 Data Type representing the configuration of connman.
12659 @item @code{connman} (default: @var{connman})
12660 The connman package to use.
12662 @item @code{disable-vpn?} (default: @code{#f})
12663 When true, disable connman's vpn plugin.
12667 @cindex WPA Supplicant
12668 @defvr {Scheme Variable} wpa-supplicant-service-type
12669 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
12670 supplicant}, an authentication daemon required to authenticate against
12671 encrypted WiFi or ethernet networks.
12674 @deftp {Data Type} wpa-supplicant-configuration
12675 Data type representing the configuration of WPA Supplicant.
12677 It takes the following parameters:
12680 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
12681 The WPA Supplicant package to use.
12683 @item @code{dbus?} (default: @code{#t})
12684 Whether to listen for requests on D-Bus.
12686 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
12687 Where to store the PID file.
12689 @item @code{interface} (default: @code{#f})
12690 If this is set, it must specify the name of a network interface that
12691 WPA supplicant will control.
12693 @item @code{config-file} (default: @code{#f})
12694 Optional configuration file to use.
12696 @item @code{extra-options} (default: @code{'()})
12697 List of additional command-line arguments to pass to the daemon.
12702 @defvr {Scheme Variable} iptables-service-type
12703 This is the service type to set up an iptables configuration. iptables is a
12704 packet filtering framework supported by the Linux kernel. This service
12705 supports configuring iptables for both IPv4 and IPv6. A simple example
12706 configuration rejecting all incoming connections except those to the ssh port
12710 (service iptables-service-type
12711 (iptables-configuration
12712 (ipv4-rules (plain-file "iptables.rules" "*filter
12716 -A INPUT -p tcp --dport 22 -j ACCEPT
12717 -A INPUT -j REJECT --reject-with icmp-port-unreachable
12720 (ipv6-rules (plain-file "ip6tables.rules" "*filter
12724 -A INPUT -p tcp --dport 22 -j ACCEPT
12725 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
12731 @deftp {Data Type} iptables-configuration
12732 The data type representing the configuration of iptables.
12735 @item @code{iptables} (default: @code{iptables})
12736 The iptables package that provides @code{iptables-restore} and
12737 @code{ip6tables-restore}.
12738 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
12739 The iptables rules to use. It will be passed to @code{iptables-restore}.
12740 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12742 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
12743 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
12744 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12749 @cindex NTP (Network Time Protocol), service
12750 @cindex real time clock
12751 @defvr {Scheme Variable} ntp-service-type
12752 This is the type of the service running the @uref{http://www.ntp.org,
12753 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
12754 system clock synchronized with that of the specified NTP servers.
12756 The value of this service is an @code{ntpd-configuration} object, as described
12760 @deftp {Data Type} ntp-configuration
12761 This is the data type for the NTP service configuration.
12764 @item @code{servers} (default: @code{%ntp-servers})
12765 This is the list of servers (host names) with which @command{ntpd} will be
12768 @item @code{allow-large-adjustment?} (default: @code{#f})
12769 This determines whether @command{ntpd} is allowed to make an initial
12770 adjustment of more than 1,000 seconds.
12772 @item @code{ntp} (default: @code{ntp})
12773 The NTP package to use.
12777 @defvr {Scheme Variable} %ntp-servers
12778 List of host names used as the default NTP servers. These are servers of the
12779 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
12783 @deffn {Scheme Procedure} openntpd-service-type
12784 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
12785 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
12786 clock synchronized with that of the given servers.
12790 openntpd-service-type
12791 (openntpd-configuration
12792 (listen-on '("127.0.0.1" "::1"))
12793 (sensor '("udcf0 correction 70000"))
12794 (constraint-from '("www.gnu.org"))
12795 (constraints-from '("https://www.google.com/"))
12796 (allow-large-adjustment? #t)))
12801 @deftp {Data Type} openntpd-configuration
12803 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
12804 The openntpd executable to use.
12805 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
12806 A list of local IP addresses or hostnames the ntpd daemon should listen on.
12807 @item @code{query-from} (default: @code{'()})
12808 A list of local IP address the ntpd daemon should use for outgoing queries.
12809 @item @code{sensor} (default: @code{'()})
12810 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
12811 will listen to each sensor that actually exists and ignore non-existent ones.
12812 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
12814 @item @code{server} (default: @var{%ntp-servers})
12815 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
12816 @item @code{servers} (default: @code{'()})
12817 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
12818 @item @code{constraint-from} (default: @code{'()})
12819 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
12820 This time information is not used for precision but acts as an authenticated
12821 constraint, thereby reducing the impact of unauthenticated NTP
12822 man-in-the-middle attacks.
12823 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
12825 @item @code{constraints-from} (default: @code{'()})
12826 As with constraint from, specify a list of URLs, IP addresses or hostnames of
12827 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
12828 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
12829 @item @code{allow-large-adjustment?} (default: @code{#f})
12830 Determines if @code{ntpd} is allowed to make an initial adjustment of more
12836 @deffn {Scheme variable} inetd-service-type
12837 This service runs the @command{inetd} (@pxref{inetd invocation,,,
12838 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
12839 connections on internet sockets, and lazily starts the specified server
12840 program when a connection is made on one of these sockets.
12842 The value of this service is an @code{inetd-configuration} object. The
12843 following example configures the @command{inetd} daemon to provide the
12844 built-in @command{echo} service, as well as an smtp service which
12845 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
12846 gateway @code{hostname}:
12851 (inetd-configuration
12855 (socket-type 'stream)
12862 (socket-type 'stream)
12866 (program (file-append openssh "/bin/ssh"))
12868 '("ssh" "-qT" "-i" "/path/to/ssh_key"
12869 "-W" "smtp-server:25" "user@@hostname")))))
12872 See below for more details about @code{inetd-configuration}.
12875 @deftp {Data Type} inetd-configuration
12876 Data type representing the configuration of @command{inetd}.
12879 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
12880 The @command{inetd} executable to use.
12882 @item @code{entries} (default: @code{'()})
12883 A list of @command{inetd} service entries. Each entry should be created
12884 by the @code{inetd-entry} constructor.
12888 @deftp {Data Type} inetd-entry
12889 Data type representing an entry in the @command{inetd} configuration.
12890 Each entry corresponds to a socket where @command{inetd} will listen for
12894 @item @code{node} (default: @code{#f})
12895 Optional string, a comma-separated list of local addresses
12896 @command{inetd} should use when listening for this service.
12897 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
12898 description of all options.
12900 A string, the name must correspond to an entry in @code{/etc/services}.
12901 @item @code{socket-type}
12902 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
12904 @item @code{protocol}
12905 A string, must correspond to an entry in @code{/etc/protocols}.
12906 @item @code{wait?} (default: @code{#t})
12907 Whether @command{inetd} should wait for the server to exit before
12908 listening to new service requests.
12910 A string containing the user (and, optionally, group) name of the user
12911 as whom the server should run. The group name can be specified in a
12912 suffix, separated by a colon or period, i.e.@: @code{"user"},
12913 @code{"user:group"} or @code{"user.group"}.
12914 @item @code{program} (default: @code{"internal"})
12915 The server program which will serve the requests, or @code{"internal"}
12916 if @command{inetd} should use a built-in service.
12917 @item @code{arguments} (default: @code{'()})
12918 A list strings or file-like objects, which are the server program's
12919 arguments, starting with the zeroth argument, i.e.@: the name of the
12920 program itself. For @command{inetd}'s internal services, this entry
12921 must be @code{'()} or @code{'("internal")}.
12924 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
12925 detailed discussion of each configuration field.
12929 @defvr {Scheme Variable} tor-service-type
12930 This is the type for a service that runs the @uref{https://torproject.org,
12931 Tor} anonymous networking daemon. The service is configured using a
12932 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
12933 @code{tor} unprivileged user, which is a member of the @code{tor} group.
12937 @deftp {Data Type} tor-configuration
12939 @item @code{tor} (default: @code{tor})
12940 The package that provides the Tor daemon. This package is expected to provide
12941 the daemon at @file{bin/tor} relative to its output directory. The default
12942 package is the @uref{https://www.torproject.org, Tor Project's}
12945 @item @code{config-file} (default: @code{(plain-file "empty" "")})
12946 The configuration file to use. It will be appended to a default configuration
12947 file, and the final configuration file will be passed to @code{tor} via its
12948 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
12949 file-like objects}). See @code{man tor} for details on the configuration file
12952 @item @code{hidden-services} (default: @code{'()})
12953 The list of @code{<hidden-service>} records to use. For any hidden service
12954 you include in this list, appropriate configuration to enable the hidden
12955 service will be automatically added to the default configuration file. You
12956 may conveniently create @code{<hidden-service>} records using the
12957 @code{tor-hidden-service} procedure described below.
12959 @item @code{socks-socket-type} (default: @code{'tcp})
12960 The default socket type that Tor should use for its SOCKS socket. This must
12961 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
12962 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
12963 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
12964 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
12967 If you want to customize the SOCKS socket in more detail, leave
12968 @code{socks-socket-type} at its default value of @code{'tcp} and use
12969 @code{config-file} to override the default by providing your own
12970 @code{SocksPort} option.
12974 @cindex hidden service
12975 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
12976 Define a new Tor @dfn{hidden service} called @var{name} and implementing
12977 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
12980 '((22 "127.0.0.1:22")
12981 (80 "127.0.0.1:8080"))
12984 In this example, port 22 of the hidden service is mapped to local port 22, and
12985 port 80 is mapped to local port 8080.
12987 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
12988 the @file{hostname} file contains the @code{.onion} host name for the hidden
12991 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
12992 project's documentation} for more information.
12995 The @code{(gnu services rsync)} module provides the following services:
12997 You might want an rsync daemon if you have files that you want available
12998 so anyone (or just yourself) can download existing files or upload new
13001 @deffn {Scheme Variable} rsync-service-type
13002 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
13003 The value for this service type is a
13004 @command{rsync-configuration} record as in this example:
13007 (service rsync-service-type)
13010 See below for details about @code{rsync-configuration}.
13013 @deftp {Data Type} rsync-configuration
13014 Data type representing the configuration for @code{rsync-service}.
13017 @item @code{package} (default: @var{rsync})
13018 @code{rsync} package to use.
13020 @item @code{port-number} (default: @code{873})
13021 TCP port on which @command{rsync} listens for incoming connections. If port
13022 is less than @code{1024} @command{rsync} needs to be started as the
13023 @code{root} user and group.
13025 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
13026 Name of the file where @command{rsync} writes its PID.
13028 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
13029 Name of the file where @command{rsync} writes its lock file.
13031 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
13032 Name of the file where @command{rsync} writes its log file.
13034 @item @code{use-chroot?} (default: @var{#t})
13035 Whether to use chroot for @command{rsync} shared directory.
13037 @item @code{share-path} (default: @file{/srv/rsync})
13038 Location of the @command{rsync} shared directory.
13040 @item @code{share-comment} (default: @code{"Rsync share"})
13041 Comment of the @command{rsync} shared directory.
13043 @item @code{read-only?} (default: @var{#f})
13044 Read-write permissions to shared directory.
13046 @item @code{timeout} (default: @code{300})
13047 I/O timeout in seconds.
13049 @item @code{user} (default: @var{"root"})
13050 Owner of the @code{rsync} process.
13052 @item @code{group} (default: @var{"root"})
13053 Group of the @code{rsync} process.
13055 @item @code{uid} (default: @var{"rsyncd"})
13056 User name or user ID that file transfers to and from that module should take
13057 place as when the daemon was run as @code{root}.
13059 @item @code{gid} (default: @var{"rsyncd"})
13060 Group name or group ID that will be used when accessing the module.
13065 Furthermore, @code{(gnu services ssh)} provides the following services.
13069 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
13070 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
13071 [#:allow-empty-passwords? #f] [#:root-login? #f] @
13072 [#:syslog-output? #t] [#:x11-forwarding? #t] @
13073 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
13074 [#:public-key-authentication? #t] [#:initialize? #t]
13075 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
13076 @var{host-key} must designate a file containing the host key, and readable
13079 When @var{daemonic?} is true, @command{lshd} will detach from the
13080 controlling terminal and log its output to syslogd, unless one sets
13081 @var{syslog-output?} to false. Obviously, it also makes lsh-service
13082 depend on existence of syslogd service. When @var{pid-file?} is true,
13083 @command{lshd} writes its PID to the file called @var{pid-file}.
13085 When @var{initialize?} is true, automatically create the seed and host key
13086 upon service activation if they do not exist yet. This may take long and
13087 require interaction.
13089 When @var{initialize?} is false, it is up to the user to initialize the
13090 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
13091 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
13092 basics,,, lsh, LSH Manual}).
13094 When @var{interfaces} is empty, lshd listens for connections on all the
13095 network interfaces; otherwise, @var{interfaces} must be a list of host names
13098 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
13099 passwords, and @var{root-login?} specifies whether to accept log-ins as
13102 The other options should be self-descriptive.
13107 @deffn {Scheme Variable} openssh-service-type
13108 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
13109 shell daemon, @command{sshd}. Its value must be an
13110 @code{openssh-configuration} record as in this example:
13113 (service openssh-service-type
13114 (openssh-configuration
13115 (x11-forwarding? #t)
13116 (permit-root-login 'without-password)
13118 `(("alice" ,(local-file "alice.pub"))
13119 ("bob" ,(local-file "bob.pub"))))))
13122 See below for details about @code{openssh-configuration}.
13124 This service can be extended with extra authorized keys, as in this
13128 (service-extension openssh-service-type
13129 (const `(("charlie"
13130 ,(local-file "charlie.pub")))))
13134 @deftp {Data Type} openssh-configuration
13135 This is the configuration record for OpenSSH's @command{sshd}.
13138 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
13139 Name of the file where @command{sshd} writes its PID.
13141 @item @code{port-number} (default: @code{22})
13142 TCP port on which @command{sshd} listens for incoming connections.
13144 @item @code{permit-root-login} (default: @code{#f})
13145 This field determines whether and when to allow logins as root. If
13146 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
13147 If it's the symbol @code{'without-password}, then root logins are
13148 permitted but not with password-based authentication.
13150 @item @code{allow-empty-passwords?} (default: @code{#f})
13151 When true, users with empty passwords may log in. When false, they may
13154 @item @code{password-authentication?} (default: @code{#t})
13155 When true, users may log in with their password. When false, they have
13156 other authentication methods.
13158 @item @code{public-key-authentication?} (default: @code{#t})
13159 When true, users may log in using public key authentication. When
13160 false, users have to use other authentication method.
13162 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
13163 This is used only by protocol version 2.
13165 @item @code{x11-forwarding?} (default: @code{#f})
13166 When true, forwarding of X11 graphical client connections is
13167 enabled---in other words, @command{ssh} options @option{-X} and
13168 @option{-Y} will work.
13170 @item @code{allow-agent-forwarding?} (default: @code{#t})
13171 Whether to allow agent forwarding.
13173 @item @code{allow-tcp-forwarding?} (default: @code{#t})
13174 Whether to allow TCP forwarding.
13176 @item @code{gateway-ports?} (default: @code{#f})
13177 Whether to allow gateway ports.
13179 @item @code{challenge-response-authentication?} (default: @code{#f})
13180 Specifies whether challenge response authentication is allowed (e.g.@: via
13183 @item @code{use-pam?} (default: @code{#t})
13184 Enables the Pluggable Authentication Module interface. If set to
13185 @code{#t}, this will enable PAM authentication using
13186 @code{challenge-response-authentication?} and
13187 @code{password-authentication?}, in addition to PAM account and session
13188 module processing for all authentication types.
13190 Because PAM challenge response authentication usually serves an
13191 equivalent role to password authentication, you should disable either
13192 @code{challenge-response-authentication?} or
13193 @code{password-authentication?}.
13195 @item @code{print-last-log?} (default: @code{#t})
13196 Specifies whether @command{sshd} should print the date and time of the
13197 last user login when a user logs in interactively.
13199 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
13200 Configures external subsystems (e.g.@: file transfer daemon).
13202 This is a list of two-element lists, each of which containing the
13203 subsystem name and a command (with optional arguments) to execute upon
13206 The command @command{internal-sftp} implements an in-process SFTP
13207 server. Alternately, one can specify the @command{sftp-server} command:
13209 (service openssh-service-type
13210 (openssh-configuration
13212 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
13215 @item @code{accepted-environment} (default: @code{'()})
13216 List of strings describing which environment variables may be exported.
13218 Each string gets on its own line. See the @code{AcceptEnv} option in
13219 @code{man sshd_config}.
13221 This example allows ssh-clients to export the @code{COLORTERM} variable.
13222 It is set by terminal emulators, which support colors. You can use it in
13223 your shell's ressource file to enable colors for the prompt and commands
13224 if this variable is set.
13227 (service openssh-service-type
13228 (openssh-configuration
13229 (accepted-environment '("COLORTERM"))))
13232 @item @code{authorized-keys} (default: @code{'()})
13233 @cindex authorized keys, SSH
13234 @cindex SSH authorized keys
13235 This is the list of authorized keys. Each element of the list is a user
13236 name followed by one or more file-like objects that represent SSH public
13240 (openssh-configuration
13242 `(("rekado" ,(local-file "rekado.pub"))
13243 ("chris" ,(local-file "chris.pub"))
13244 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
13248 registers the specified public keys for user accounts @code{rekado},
13249 @code{chris}, and @code{root}.
13251 Additional authorized keys can be specified @i{via}
13252 @code{service-extension}.
13254 Note that this does @emph{not} interfere with the use of
13255 @file{~/.ssh/authorized_keys}.
13257 @item @code{log-level} (default: @code{'info})
13258 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
13259 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
13260 page for @file{sshd_config} for the full list of level names.
13262 @item @code{extra-content} (default: @code{""})
13263 This field can be used to append arbitrary text to the configuration file. It
13264 is especially useful for elaborate configurations that cannot be expressed
13265 otherwise. This configuration, for example, would generally disable root
13266 logins, but permit them from one specific IP address:
13269 (openssh-configuration
13271 Match Address 192.168.0.1
13272 PermitRootLogin yes"))
13278 @deffn {Scheme Procedure} dropbear-service [@var{config}]
13279 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
13280 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
13283 For example, to specify a Dropbear service listening on port 1234, add
13284 this call to the operating system's @code{services} field:
13287 (dropbear-service (dropbear-configuration
13288 (port-number 1234)))
13292 @deftp {Data Type} dropbear-configuration
13293 This data type represents the configuration of a Dropbear SSH daemon.
13296 @item @code{dropbear} (default: @var{dropbear})
13297 The Dropbear package to use.
13299 @item @code{port-number} (default: 22)
13300 The TCP port where the daemon waits for incoming connections.
13302 @item @code{syslog-output?} (default: @code{#t})
13303 Whether to enable syslog output.
13305 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
13306 File name of the daemon's PID file.
13308 @item @code{root-login?} (default: @code{#f})
13309 Whether to allow @code{root} logins.
13311 @item @code{allow-empty-passwords?} (default: @code{#f})
13312 Whether to allow empty passwords.
13314 @item @code{password-authentication?} (default: @code{#t})
13315 Whether to enable password-based authentication.
13319 @defvr {Scheme Variable} %facebook-host-aliases
13320 This variable contains a string for use in @file{/etc/hosts}
13321 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
13322 line contains a entry that maps a known server name of the Facebook
13323 on-line service---e.g., @code{www.facebook.com}---to the local
13324 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
13326 This variable is typically used in the @code{hosts-file} field of an
13327 @code{operating-system} declaration (@pxref{operating-system Reference,
13328 @file{/etc/hosts}}):
13331 (use-modules (gnu) (guix))
13334 (host-name "mymachine")
13337 ;; Create a /etc/hosts file with aliases for "localhost"
13338 ;; and "mymachine", as well as for Facebook servers.
13339 (plain-file "hosts"
13340 (string-append (local-host-aliases host-name)
13341 %facebook-host-aliases))))
13344 This mechanism can prevent programs running locally, such as Web
13345 browsers, from accessing Facebook.
13348 The @code{(gnu services avahi)} provides the following definition.
13350 @defvr {Scheme Variable} avahi-service-type
13351 This is the service that runs @command{avahi-daemon}, a system-wide
13352 mDNS/DNS-SD responder that allows for service discovery and
13353 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
13354 Its value must be a @code{zero-configuration} record---see below.
13356 This service extends the name service cache daemon (nscd) so that it can
13357 resolve @code{.local} host names using
13358 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
13359 Service Switch}, for information on host name resolution.
13361 Additionally, add the @var{avahi} package to the system profile so that
13362 commands such as @command{avahi-browse} are directly usable.
13365 @deftp {Data Type} avahi-configuration
13366 Data type representation the configuration for Avahi.
13370 @item @code{host-name} (default: @code{#f})
13371 If different from @code{#f}, use that as the host name to
13372 publish for this machine; otherwise, use the machine's actual host name.
13374 @item @code{publish?} (default: @code{#t})
13375 When true, allow host names and services to be published (broadcast) over the
13378 @item @code{publish-workstation?} (default: @code{#t})
13379 When true, @command{avahi-daemon} publishes the machine's host name and IP
13380 address via mDNS on the local network. To view the host names published on
13381 your local network, you can run:
13384 avahi-browse _workstation._tcp
13387 @item @code{wide-area?} (default: @code{#f})
13388 When true, DNS-SD over unicast DNS is enabled.
13390 @item @code{ipv4?} (default: @code{#t})
13391 @itemx @code{ipv6?} (default: @code{#t})
13392 These fields determine whether to use IPv4/IPv6 sockets.
13394 @item @code{domains-to-browse} (default: @code{'()})
13395 This is a list of domains to browse.
13399 @deffn {Scheme Variable} openvswitch-service-type
13400 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
13401 service, whose value should be an @code{openvswitch-configuration}
13405 @deftp {Data Type} openvswitch-configuration
13406 Data type representing the configuration of Open vSwitch, a multilayer
13407 virtual switch which is designed to enable massive network automation
13408 through programmatic extension.
13411 @item @code{package} (default: @var{openvswitch})
13412 Package object of the Open vSwitch.
13418 @subsection X Window
13421 @cindex X Window System
13422 @cindex login manager
13423 Support for the X Window graphical display system---specifically
13424 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
13425 there is no @code{xorg-service} procedure. Instead, the X server is
13426 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
13429 @cindex GNOME, login manager
13430 GDM of course allows users to log in into window managers and desktop
13431 environments other than GNOME; for those using GNOME, GDM is required for
13432 features such as automatic screen locking.
13434 @cindex window manager
13435 To use X11, you must install at least one @dfn{window manager}---for
13436 example the @code{windowmaker} or @code{openbox} packages---preferably
13437 by adding it to the @code{packages} field of your operating system
13438 definition (@pxref{operating-system Reference, system-wide packages}).
13440 @defvr {Scheme Variable} gdm-service-type
13441 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
13442 Desktop Manager} (GDM), a program that manages graphical display servers and
13443 handles graphical user logins. Its value must be a @code{gdm-configuration}
13446 @cindex session types (X11)
13447 @cindex X11 session types
13448 GDM looks for @dfn{session types} described by the @file{.desktop} files in
13449 @file{/run/current-system/profile/share/xsessions} and allows users to choose
13450 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
13451 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
13452 set of packages automatically makes them available at the log-in screen.
13454 In addition, @file{~/.xsession} files are honored. When available,
13455 @file{~/.xsession} must be an executable that starts a window manager
13456 and/or other X clients.
13459 @deftp {Data Type} gdm-configuration
13461 @item @code{auto-login?} (default: @code{#f})
13462 @itemx @code{default-user} (default: @code{#f})
13463 When @code{auto-login?} is false, GDM presents a log-in screen.
13465 When @code{auto-login?} is true, GDM logs in directly as
13466 @code{default-user}.
13468 @item @code{gnome-shell-assets} (default: ...)
13469 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
13471 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
13472 Configuration of the Xorg graphical server.
13474 @item @code{xsession} (default: @code{(xinitrc)})
13475 Script to run before starting a X session.
13477 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
13478 File name of the @code{dbus-daemon} executable.
13480 @item @code{gdm} (default: @code{gdm})
13481 The GDM package to use.
13485 @defvr {Scheme Variable} slim-service-type
13486 This is the type for the SLiM graphical login manager for X11.
13488 Like GDM, SLiM looks for session types described by @file{.desktop} files and
13489 allows users to choose a session from the log-in screen using @kbd{F1}. It
13490 also honors @file{~/.xsession} files.
13492 Unlike GDM, SLiM does not spawn the user session on a different VT after
13493 logging in, which means that you can only start one graphical session. If you
13494 want to be able to run multiple graphical sessions at the same time you have
13495 to add multiple SLiM services to your system services. The following example
13496 shows how to replace the default GDM service with two SLiM services on tty7
13500 (use-modules (gnu services)
13501 (gnu services desktop)
13502 (gnu services xorg)
13503 (srfi srfi-1)) ;for 'remove'
13507 (services (cons* (service slim-service-type (slim-configuration
13510 (service slim-service-type (slim-configuration
13513 (remove (lambda (service)
13514 (eq? (service-kind service) gdm-service-type))
13515 %desktop-services))))
13520 @deftp {Data Type} slim-configuration
13521 Data type representing the configuration of @code{slim-service-type}.
13524 @item @code{allow-empty-passwords?} (default: @code{#t})
13525 Whether to allow logins with empty passwords.
13527 @item @code{auto-login?} (default: @code{#f})
13528 @itemx @code{default-user} (default: @code{""})
13529 When @code{auto-login?} is false, SLiM presents a log-in screen.
13531 When @code{auto-login?} is true, SLiM logs in directly as
13532 @code{default-user}.
13534 @item @code{theme} (default: @code{%default-slim-theme})
13535 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
13536 The graphical theme to use and its name.
13538 @item @code{auto-login-session} (default: @code{#f})
13539 If true, this must be the name of the executable to start as the default
13540 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
13542 If false, a session described by one of the available @file{.desktop}
13543 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
13547 You must install at least one window manager in the system profile or in
13548 your user profile. Failing to do that, if @code{auto-login-session} is
13549 false, you will be unable to log in.
13552 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13553 Configuration of the Xorg graphical server.
13555 @item @code{display} (default @code{":0"})
13556 The display on which to start the Xorg graphical server.
13558 @item @code{vt} (default @code{"vt7"})
13559 The VT on which to start the Xorg graphical server.
13561 @item @code{xauth} (default: @code{xauth})
13562 The XAuth package to use.
13564 @item @code{shepherd} (default: @code{shepherd})
13565 The Shepherd package used when invoking @command{halt} and
13568 @item @code{sessreg} (default: @code{sessreg})
13569 The sessreg package used in order to register the session.
13571 @item @code{slim} (default: @code{slim})
13572 The SLiM package to use.
13576 @defvr {Scheme Variable} %default-theme
13577 @defvrx {Scheme Variable} %default-theme-name
13578 The default SLiM theme and its name.
13582 @deftp {Data Type} sddm-configuration
13583 This is the data type representing the sddm service configuration.
13586 @item @code{display-server} (default: "x11")
13587 Select display server to use for the greeter. Valid values are "x11"
13590 @item @code{numlock} (default: "on")
13591 Valid values are "on", "off" or "none".
13593 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
13594 Command to run when halting.
13596 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
13597 Command to run when rebooting.
13599 @item @code{theme} (default "maldives")
13600 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
13602 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
13603 Directory to look for themes.
13605 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
13606 Directory to look for faces.
13608 @item @code{default-path} (default "/run/current-system/profile/bin")
13609 Default PATH to use.
13611 @item @code{minimum-uid} (default 1000)
13612 Minimum UID to display in SDDM.
13614 @item @code{maximum-uid} (default 2000)
13615 Maximum UID to display in SDDM
13617 @item @code{remember-last-user?} (default #t)
13618 Remember last user.
13620 @item @code{remember-last-session?} (default #t)
13621 Remember last session.
13623 @item @code{hide-users} (default "")
13624 Usernames to hide from SDDM greeter.
13626 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
13627 Users with shells listed will be hidden from the SDDM greeter.
13629 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
13630 Script to run before starting a wayland session.
13632 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
13633 Directory to look for desktop files starting wayland sessions.
13635 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13636 Configuration of the Xorg graphical server.
13638 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
13641 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
13644 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
13645 Script to run after starting xorg-server.
13647 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
13648 Script to run before stopping xorg-server.
13650 @item @code{xsession-command} (default: @code{xinitrc})
13651 Script to run before starting a X session.
13653 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
13654 Directory to look for desktop files starting X sessions.
13656 @item @code{minimum-vt} (default: 7)
13659 @item @code{auto-login-user} (default "")
13660 User to use for auto-login.
13662 @item @code{auto-login-session} (default "")
13663 Desktop file to use for auto-login.
13665 @item @code{relogin?} (default #f)
13666 Relogin after logout.
13671 @cindex login manager
13673 @deffn {Scheme Procedure} sddm-service config
13674 Return a service that spawns the SDDM graphical login manager for config of
13675 type @code{<sddm-configuration>}.
13678 (sddm-service (sddm-configuration
13679 (auto-login-user "Alice")
13680 (auto-login-session "xfce.desktop")))
13684 @cindex Xorg, configuration
13685 @deftp {Data Type} xorg-configuration
13686 This data type represents the configuration of the Xorg graphical display
13687 server. Note that there is not Xorg service; instead, the X server is started
13688 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
13689 of these display managers aggregates an @code{xorg-configuration} record.
13692 @item @code{modules} (default: @code{%default-xorg-modules})
13693 This is a list of @dfn{module packages} loaded by the Xorg
13694 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
13696 @item @code{fonts} (default: @code{%default-xorg-fonts})
13697 This is a list of font directories to add to the server's @dfn{font path}.
13699 @item @code{drivers} (default: @code{'()})
13700 This must be either the empty list, in which case Xorg chooses a graphics
13701 driver automatically, or a list of driver names that will be tried in this
13702 order---e.g., @code{("modesetting" "vesa")}.
13704 @item @code{resolutions} (default: @code{'()})
13705 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
13706 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
13709 @cindex keyboard layout, for Xorg
13710 @cindex keymap, for Xorg
13711 @item @code{keyboard-layout} (default: @code{#f})
13712 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
13713 English (``qwerty'') for a 105-key PC keyboard.
13715 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
13716 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
13717 information on how to specify the keyboard layout.
13719 @item @code{extra-config} (default: @code{'()})
13720 This is a list of strings or objects appended to the configuration file. It
13721 is used to pass extra text to be added verbatim to the configuration file.
13723 @item @code{server} (default: @code{xorg-server})
13724 This is the package providing the Xorg server.
13726 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
13727 This is the list of command-line arguments to pass to the X server. The
13728 default is @code{-nolisten tcp}.
13732 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
13733 [@var{login-manager-service-type}]
13734 Tell the log-in manager (of type @var{login-manager-service-type}) to use
13735 @var{config}, an @code{<xorg-configuration>} record.
13737 Since the Xorg configuration is embedded in the log-in manager's
13738 configuration---e.g., @code{gdm-configuration}---this procedure provides a
13739 shorthand to set the Xorg configuration.
13742 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
13743 Return a @code{startx} script in which the modules, fonts, etc. specified
13744 in @var{config}, are available. The result should be used in place of
13747 Usually the X server is started by a login manager.
13751 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
13752 Add @var{package}, a package for a screen locker or screen saver whose
13753 command is @var{program}, to the set of setuid programs and add a PAM entry
13754 for it. For example:
13757 (screen-locker-service xlockmore "xlock")
13760 makes the good ol' XlockMore usable.
13764 @node Printing Services
13765 @subsection Printing Services
13767 @cindex printer support with CUPS
13768 The @code{(gnu services cups)} module provides a Guix service definition
13769 for the CUPS printing service. To add printer support to a Guix
13770 system, add a @code{cups-service} to the operating system definition:
13772 @deffn {Scheme Variable} cups-service-type
13773 The service type for the CUPS print server. Its value should be a valid
13774 CUPS configuration (see below). To use the default settings, simply
13777 (service cups-service-type)
13781 The CUPS configuration controls the basic things about your CUPS
13782 installation: what interfaces it listens on, what to do if a print job
13783 fails, how much logging to do, and so on. To actually add a printer,
13784 you have to visit the @url{http://localhost:631} URL, or use a tool such
13785 as GNOME's printer configuration services. By default, configuring a
13786 CUPS service will generate a self-signed certificate if needed, for
13787 secure connections to the print server.
13789 Suppose you want to enable the Web interface of CUPS and also add
13790 support for Epson printers @i{via} the @code{escpr} package and for HP
13791 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
13792 like this (you need to use the @code{(gnu packages cups)} module):
13795 (service cups-service-type
13796 (cups-configuration
13797 (web-interface? #t)
13799 (list cups-filters escpr hplip-minimal))))
13802 Note: If you wish to use the Qt5 based GUI which comes with the hplip
13803 package then it is suggested that you install the @code{hplip} package,
13804 either in your OS configuration file or as your user.
13806 The available configuration parameters follow. Each parameter
13807 definition is preceded by its type; for example, @samp{string-list foo}
13808 indicates that the @code{foo} parameter should be specified as a list of
13809 strings. There is also a way to specify the configuration as a string,
13810 if you have an old @code{cupsd.conf} file that you want to port over
13811 from some other system; see the end for more details.
13813 @c The following documentation was initially generated by
13814 @c (generate-documentation) in (gnu services cups). Manually maintained
13815 @c documentation is better, so we shouldn't hesitate to edit below as
13816 @c needed. However if the change you want to make to this documentation
13817 @c can be done in an automated way, it's probably easier to change
13818 @c (generate-documentation) than to make it below and have to deal with
13819 @c the churn as CUPS updates.
13822 Available @code{cups-configuration} fields are:
13824 @deftypevr {@code{cups-configuration} parameter} package cups
13828 @deftypevr {@code{cups-configuration} parameter} package-list extensions
13829 Drivers and other extensions to the CUPS package.
13832 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
13833 Configuration of where to write logs, what directories to use for print
13834 spools, and related privileged configuration parameters.
13836 Available @code{files-configuration} fields are:
13838 @deftypevr {@code{files-configuration} parameter} log-location access-log
13839 Defines the access log filename. Specifying a blank filename disables
13840 access log generation. The value @code{stderr} causes log entries to be
13841 sent to the standard error file when the scheduler is running in the
13842 foreground, or to the system log daemon when run in the background. The
13843 value @code{syslog} causes log entries to be sent to the system log
13844 daemon. The server name may be included in filenames using the string
13845 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
13847 Defaults to @samp{"/var/log/cups/access_log"}.
13850 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
13851 Where CUPS should cache data.
13853 Defaults to @samp{"/var/cache/cups"}.
13856 @deftypevr {@code{files-configuration} parameter} string config-file-perm
13857 Specifies the permissions for all configuration files that the scheduler
13860 Note that the permissions for the printers.conf file are currently
13861 masked to only allow access from the scheduler user (typically root).
13862 This is done because printer device URIs sometimes contain sensitive
13863 authentication information that should not be generally known on the
13864 system. There is no way to disable this security feature.
13866 Defaults to @samp{"0640"}.
13869 @deftypevr {@code{files-configuration} parameter} log-location error-log
13870 Defines the error log filename. Specifying a blank filename disables
13871 error log generation. The value @code{stderr} causes log entries to be
13872 sent to the standard error file when the scheduler is running in the
13873 foreground, or to the system log daemon when run in the background. The
13874 value @code{syslog} causes log entries to be sent to the system log
13875 daemon. The server name may be included in filenames using the string
13876 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
13878 Defaults to @samp{"/var/log/cups/error_log"}.
13881 @deftypevr {@code{files-configuration} parameter} string fatal-errors
13882 Specifies which errors are fatal, causing the scheduler to exit. The
13887 No errors are fatal.
13890 All of the errors below are fatal.
13893 Browsing initialization errors are fatal, for example failed connections
13894 to the DNS-SD daemon.
13897 Configuration file syntax errors are fatal.
13900 Listen or Port errors are fatal, except for IPv6 failures on the
13901 loopback or @code{any} addresses.
13904 Log file creation or write errors are fatal.
13907 Bad startup file permissions are fatal, for example shared TLS
13908 certificate and key files with world-read permissions.
13911 Defaults to @samp{"all -browse"}.
13914 @deftypevr {@code{files-configuration} parameter} boolean file-device?
13915 Specifies whether the file pseudo-device can be used for new printer
13916 queues. The URI @uref{file:///dev/null} is always allowed.
13918 Defaults to @samp{#f}.
13921 @deftypevr {@code{files-configuration} parameter} string group
13922 Specifies the group name or ID that will be used when executing external
13925 Defaults to @samp{"lp"}.
13928 @deftypevr {@code{files-configuration} parameter} string log-file-perm
13929 Specifies the permissions for all log files that the scheduler writes.
13931 Defaults to @samp{"0644"}.
13934 @deftypevr {@code{files-configuration} parameter} log-location page-log
13935 Defines the page log filename. Specifying a blank filename disables
13936 page log generation. The value @code{stderr} causes log entries to be
13937 sent to the standard error file when the scheduler is running in the
13938 foreground, or to the system log daemon when run in the background. The
13939 value @code{syslog} causes log entries to be sent to the system log
13940 daemon. The server name may be included in filenames using the string
13941 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
13943 Defaults to @samp{"/var/log/cups/page_log"}.
13946 @deftypevr {@code{files-configuration} parameter} string remote-root
13947 Specifies the username that is associated with unauthenticated accesses
13948 by clients claiming to be the root user. The default is @code{remroot}.
13950 Defaults to @samp{"remroot"}.
13953 @deftypevr {@code{files-configuration} parameter} file-name request-root
13954 Specifies the directory that contains print jobs and other HTTP request
13957 Defaults to @samp{"/var/spool/cups"}.
13960 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
13961 Specifies the level of security sandboxing that is applied to print
13962 filters, backends, and other child processes of the scheduler; either
13963 @code{relaxed} or @code{strict}. This directive is currently only
13964 used/supported on macOS.
13966 Defaults to @samp{strict}.
13969 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
13970 Specifies the location of TLS certificates and private keys. CUPS will
13971 look for public and private keys in this directory: a @code{.crt} files
13972 for PEM-encoded certificates and corresponding @code{.key} files for
13973 PEM-encoded private keys.
13975 Defaults to @samp{"/etc/cups/ssl"}.
13978 @deftypevr {@code{files-configuration} parameter} file-name server-root
13979 Specifies the directory containing the server configuration files.
13981 Defaults to @samp{"/etc/cups"}.
13984 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
13985 Specifies whether the scheduler calls fsync(2) after writing
13986 configuration or state files.
13988 Defaults to @samp{#f}.
13991 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
13992 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
13995 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
13996 Specifies the directory where temporary files are stored.
13998 Defaults to @samp{"/var/spool/cups/tmp"}.
14001 @deftypevr {@code{files-configuration} parameter} string user
14002 Specifies the user name or ID that is used when running external
14005 Defaults to @samp{"lp"}.
14009 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
14010 Specifies the logging level for the AccessLog file. The @code{config}
14011 level logs when printers and classes are added, deleted, or modified and
14012 when configuration files are accessed or updated. The @code{actions}
14013 level logs when print jobs are submitted, held, released, modified, or
14014 canceled, and any of the conditions for @code{config}. The @code{all}
14015 level logs all requests.
14017 Defaults to @samp{actions}.
14020 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
14021 Specifies whether to purge job history data automatically when it is no
14022 longer required for quotas.
14024 Defaults to @samp{#f}.
14027 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
14028 Specifies which protocols to use for local printer sharing.
14030 Defaults to @samp{dnssd}.
14033 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
14034 Specifies whether the CUPS web interface is advertised.
14036 Defaults to @samp{#f}.
14039 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
14040 Specifies whether shared printers are advertised.
14042 Defaults to @samp{#f}.
14045 @deftypevr {@code{cups-configuration} parameter} string classification
14046 Specifies the security classification of the server. Any valid banner
14047 name can be used, including "classified", "confidential", "secret",
14048 "topsecret", and "unclassified", or the banner can be omitted to disable
14049 secure printing functions.
14051 Defaults to @samp{""}.
14054 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
14055 Specifies whether users may override the classification (cover page) of
14056 individual print jobs using the @code{job-sheets} option.
14058 Defaults to @samp{#f}.
14061 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
14062 Specifies the default type of authentication to use.
14064 Defaults to @samp{Basic}.
14067 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
14068 Specifies whether encryption will be used for authenticated requests.
14070 Defaults to @samp{Required}.
14073 @deftypevr {@code{cups-configuration} parameter} string default-language
14074 Specifies the default language to use for text and web content.
14076 Defaults to @samp{"en"}.
14079 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
14080 Specifies the default paper size for new print queues. @samp{"Auto"}
14081 uses a locale-specific default, while @samp{"None"} specifies there is
14082 no default paper size. Specific size names are typically
14083 @samp{"Letter"} or @samp{"A4"}.
14085 Defaults to @samp{"Auto"}.
14088 @deftypevr {@code{cups-configuration} parameter} string default-policy
14089 Specifies the default access policy to use.
14091 Defaults to @samp{"default"}.
14094 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
14095 Specifies whether local printers are shared by default.
14097 Defaults to @samp{#t}.
14100 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
14101 Specifies the delay for updating of configuration and state files, in
14102 seconds. A value of 0 causes the update to happen as soon as possible,
14103 typically within a few milliseconds.
14105 Defaults to @samp{30}.
14108 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
14109 Specifies what to do when an error occurs. Possible values are
14110 @code{abort-job}, which will discard the failed print job;
14111 @code{retry-job}, which will retry the job at a later time;
14112 @code{retry-this-job}, which retries the failed job immediately; and
14113 @code{stop-printer}, which stops the printer.
14115 Defaults to @samp{stop-printer}.
14118 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
14119 Specifies the maximum cost of filters that are run concurrently, which
14120 can be used to minimize disk, memory, and CPU resource problems. A
14121 limit of 0 disables filter limiting. An average print to a
14122 non-PostScript printer needs a filter limit of about 200. A PostScript
14123 printer needs about half that (100). Setting the limit below these
14124 thresholds will effectively limit the scheduler to printing a single job
14127 Defaults to @samp{0}.
14130 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
14131 Specifies the scheduling priority of filters that are run to print a
14132 job. The nice value ranges from 0, the highest priority, to 19, the
14135 Defaults to @samp{0}.
14138 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
14139 Specifies whether to do reverse lookups on connecting clients. The
14140 @code{double} setting causes @code{cupsd} to verify that the hostname
14141 resolved from the address matches one of the addresses returned for that
14142 hostname. Double lookups also prevent clients with unregistered
14143 addresses from connecting to your server. Only set this option to
14144 @code{#t} or @code{double} if absolutely required.
14146 Defaults to @samp{#f}.
14149 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
14150 Specifies the number of seconds to wait before killing the filters and
14151 backend associated with a canceled or held job.
14153 Defaults to @samp{30}.
14156 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
14157 Specifies the interval between retries of jobs in seconds. This is
14158 typically used for fax queues but can also be used with normal print
14159 queues whose error policy is @code{retry-job} or
14160 @code{retry-current-job}.
14162 Defaults to @samp{30}.
14165 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
14166 Specifies the number of retries that are done for jobs. This is
14167 typically used for fax queues but can also be used with normal print
14168 queues whose error policy is @code{retry-job} or
14169 @code{retry-current-job}.
14171 Defaults to @samp{5}.
14174 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
14175 Specifies whether to support HTTP keep-alive connections.
14177 Defaults to @samp{#t}.
14180 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
14181 Specifies how long an idle client connection remains open, in seconds.
14183 Defaults to @samp{30}.
14186 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
14187 Specifies the maximum size of print files, IPP requests, and HTML form
14188 data. A limit of 0 disables the limit check.
14190 Defaults to @samp{0}.
14193 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
14194 Listens on the specified interfaces for connections. Valid values are
14195 of the form @var{address}:@var{port}, where @var{address} is either an
14196 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
14197 indicate all addresses. Values can also be file names of local UNIX
14198 domain sockets. The Listen directive is similar to the Port directive
14199 but allows you to restrict access to specific interfaces or networks.
14202 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
14203 Specifies the number of pending connections that will be allowed. This
14204 normally only affects very busy servers that have reached the MaxClients
14205 limit, but can also be triggered by large numbers of simultaneous
14206 connections. When the limit is reached, the operating system will
14207 refuse additional connections until the scheduler can accept the pending
14210 Defaults to @samp{128}.
14213 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
14214 Specifies a set of additional access controls.
14216 Available @code{location-access-controls} fields are:
14218 @deftypevr {@code{location-access-controls} parameter} file-name path
14219 Specifies the URI path to which the access control applies.
14222 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
14223 Access controls for all access to this path, in the same format as the
14224 @code{access-controls} of @code{operation-access-control}.
14226 Defaults to @samp{()}.
14229 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
14230 Access controls for method-specific access to this path.
14232 Defaults to @samp{()}.
14234 Available @code{method-access-controls} fields are:
14236 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
14237 If @code{#t}, apply access controls to all methods except the listed
14238 methods. Otherwise apply to only the listed methods.
14240 Defaults to @samp{#f}.
14243 @deftypevr {@code{method-access-controls} parameter} method-list methods
14244 Methods to which this access control applies.
14246 Defaults to @samp{()}.
14249 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
14250 Access control directives, as a list of strings. Each string should be
14251 one directive, such as "Order allow,deny".
14253 Defaults to @samp{()}.
14258 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
14259 Specifies the number of debugging messages that are retained for logging
14260 if an error occurs in a print job. Debug messages are logged regardless
14261 of the LogLevel setting.
14263 Defaults to @samp{100}.
14266 @deftypevr {@code{cups-configuration} parameter} log-level log-level
14267 Specifies the level of logging for the ErrorLog file. The value
14268 @code{none} stops all logging while @code{debug2} logs everything.
14270 Defaults to @samp{info}.
14273 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
14274 Specifies the format of the date and time in the log files. The value
14275 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
14277 Defaults to @samp{standard}.
14280 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
14281 Specifies the maximum number of simultaneous clients that are allowed by
14284 Defaults to @samp{100}.
14287 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
14288 Specifies the maximum number of simultaneous clients that are allowed
14289 from a single address.
14291 Defaults to @samp{100}.
14294 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
14295 Specifies the maximum number of copies that a user can print of each
14298 Defaults to @samp{9999}.
14301 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
14302 Specifies the maximum time a job may remain in the @code{indefinite}
14303 hold state before it is canceled. A value of 0 disables cancellation of
14306 Defaults to @samp{0}.
14309 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
14310 Specifies the maximum number of simultaneous jobs that are allowed. Set
14311 to 0 to allow an unlimited number of jobs.
14313 Defaults to @samp{500}.
14316 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
14317 Specifies the maximum number of simultaneous jobs that are allowed per
14318 printer. A value of 0 allows up to MaxJobs jobs per printer.
14320 Defaults to @samp{0}.
14323 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
14324 Specifies the maximum number of simultaneous jobs that are allowed per
14325 user. A value of 0 allows up to MaxJobs jobs per user.
14327 Defaults to @samp{0}.
14330 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
14331 Specifies the maximum time a job may take to print before it is
14332 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
14334 Defaults to @samp{10800}.
14337 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
14338 Specifies the maximum size of the log files before they are rotated, in
14339 bytes. The value 0 disables log rotation.
14341 Defaults to @samp{1048576}.
14344 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
14345 Specifies the maximum amount of time to allow between files in a
14346 multiple file print job, in seconds.
14348 Defaults to @samp{300}.
14351 @deftypevr {@code{cups-configuration} parameter} string page-log-format
14352 Specifies the format of PageLog lines. Sequences beginning with percent
14353 (@samp{%}) characters are replaced with the corresponding information,
14354 while all other characters are copied literally. The following percent
14355 sequences are recognized:
14359 insert a single percent character
14362 insert the value of the specified IPP attribute
14365 insert the number of copies for the current page
14368 insert the current page number
14371 insert the current date and time in common log format
14377 insert the printer name
14380 insert the username
14383 A value of the empty string disables page logging. The string @code{%p
14384 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
14385 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
14388 Defaults to @samp{""}.
14391 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
14392 Passes the specified environment variable(s) to child processes; a list
14395 Defaults to @samp{()}.
14398 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
14399 Specifies named access control policies.
14401 Available @code{policy-configuration} fields are:
14403 @deftypevr {@code{policy-configuration} parameter} string name
14404 Name of the policy.
14407 @deftypevr {@code{policy-configuration} parameter} string job-private-access
14408 Specifies an access list for a job's private values. @code{@@ACL} maps
14409 to the printer's requesting-user-name-allowed or
14410 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14411 owner. @code{@@SYSTEM} maps to the groups listed for the
14412 @code{system-group} field of the @code{files-config} configuration,
14413 which is reified into the @code{cups-files.conf(5)} file. Other
14414 possible elements of the access list include specific user names, and
14415 @code{@@@var{group}} to indicate members of a specific group. The
14416 access list may also be simply @code{all} or @code{default}.
14418 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14421 @deftypevr {@code{policy-configuration} parameter} string job-private-values
14422 Specifies the list of job values to make private, or @code{all},
14423 @code{default}, or @code{none}.
14425 Defaults to @samp{"job-name job-originating-host-name
14426 job-originating-user-name phone"}.
14429 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
14430 Specifies an access list for a subscription's private values.
14431 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
14432 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14433 owner. @code{@@SYSTEM} maps to the groups listed for the
14434 @code{system-group} field of the @code{files-config} configuration,
14435 which is reified into the @code{cups-files.conf(5)} file. Other
14436 possible elements of the access list include specific user names, and
14437 @code{@@@var{group}} to indicate members of a specific group. The
14438 access list may also be simply @code{all} or @code{default}.
14440 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14443 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
14444 Specifies the list of job values to make private, or @code{all},
14445 @code{default}, or @code{none}.
14447 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
14448 notify-subscriber-user-name notify-user-data"}.
14451 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
14452 Access control by IPP operation.
14454 Defaults to @samp{()}.
14458 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
14459 Specifies whether job files (documents) are preserved after a job is
14460 printed. If a numeric value is specified, job files are preserved for
14461 the indicated number of seconds after printing. Otherwise a boolean
14462 value applies indefinitely.
14464 Defaults to @samp{86400}.
14467 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
14468 Specifies whether the job history is preserved after a job is printed.
14469 If a numeric value is specified, the job history is preserved for the
14470 indicated number of seconds after printing. If @code{#t}, the job
14471 history is preserved until the MaxJobs limit is reached.
14473 Defaults to @samp{#t}.
14476 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
14477 Specifies the amount of time to wait for job completion before
14478 restarting the scheduler.
14480 Defaults to @samp{30}.
14483 @deftypevr {@code{cups-configuration} parameter} string rip-cache
14484 Specifies the maximum amount of memory to use when converting documents
14485 into bitmaps for a printer.
14487 Defaults to @samp{"128m"}.
14490 @deftypevr {@code{cups-configuration} parameter} string server-admin
14491 Specifies the email address of the server administrator.
14493 Defaults to @samp{"root@@localhost.localdomain"}.
14496 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
14497 The ServerAlias directive is used for HTTP Host header validation when
14498 clients connect to the scheduler from external interfaces. Using the
14499 special name @code{*} can expose your system to known browser-based DNS
14500 rebinding attacks, even when accessing sites through a firewall. If the
14501 auto-discovery of alternate names does not work, we recommend listing
14502 each alternate name with a ServerAlias directive instead of using
14505 Defaults to @samp{*}.
14508 @deftypevr {@code{cups-configuration} parameter} string server-name
14509 Specifies the fully-qualified host name of the server.
14511 Defaults to @samp{"localhost"}.
14514 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
14515 Specifies what information is included in the Server header of HTTP
14516 responses. @code{None} disables the Server header. @code{ProductOnly}
14517 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
14518 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
14519 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
14520 the output of the @code{uname} command. @code{Full} reports @code{CUPS
14521 2.0.0 (@var{uname}) IPP/2.0}.
14523 Defaults to @samp{Minimal}.
14526 @deftypevr {@code{cups-configuration} parameter} string set-env
14527 Set the specified environment variable to be passed to child processes.
14529 Defaults to @samp{"variable value"}.
14532 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
14533 Listens on the specified interfaces for encrypted connections. Valid
14534 values are of the form @var{address}:@var{port}, where @var{address} is
14535 either an IPv6 address enclosed in brackets, an IPv4 address, or
14536 @code{*} to indicate all addresses.
14538 Defaults to @samp{()}.
14541 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
14542 Sets encryption options. By default, CUPS only supports encryption
14543 using TLS v1.0 or higher using known secure cipher suites. The
14544 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
14545 required for some older clients that do not implement newer ones. The
14546 @code{AllowSSL3} option enables SSL v3.0, which is required for some
14547 older clients that do not support TLS v1.0.
14549 Defaults to @samp{()}.
14552 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
14553 Specifies whether the scheduler requires clients to strictly adhere to
14554 the IPP specifications.
14556 Defaults to @samp{#f}.
14559 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
14560 Specifies the HTTP request timeout, in seconds.
14562 Defaults to @samp{300}.
14566 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
14567 Specifies whether the web interface is enabled.
14569 Defaults to @samp{#f}.
14572 At this point you're probably thinking ``oh dear, Guix manual, I like
14573 you but you can stop already with the configuration options''. Indeed.
14574 However, one more point: it could be that you have an existing
14575 @code{cupsd.conf} that you want to use. In that case, you can pass an
14576 @code{opaque-cups-configuration} as the configuration of a
14577 @code{cups-service-type}.
14579 Available @code{opaque-cups-configuration} fields are:
14581 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
14585 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
14586 The contents of the @code{cupsd.conf}, as a string.
14589 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
14590 The contents of the @code{cups-files.conf} file, as a string.
14593 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
14594 strings of the same name, you could instantiate a CUPS service like
14598 (service cups-service-type
14599 (opaque-cups-configuration
14600 (cupsd.conf cupsd.conf)
14601 (cups-files.conf cups-files.conf)))
14605 @node Desktop Services
14606 @subsection Desktop Services
14608 The @code{(gnu services desktop)} module provides services that are
14609 usually useful in the context of a ``desktop'' setup---that is, on a
14610 machine running a graphical display server, possibly with graphical user
14611 interfaces, etc. It also defines services that provide specific desktop
14612 environments like GNOME, Xfce or MATE.
14614 To simplify things, the module defines a variable containing the set of
14615 services that users typically expect on a machine with a graphical
14616 environment and networking:
14618 @defvr {Scheme Variable} %desktop-services
14619 This is a list of services that builds upon @var{%base-services} and
14620 adds or adjusts services for a typical ``desktop'' setup.
14622 In particular, it adds a graphical login manager (@pxref{X Window,
14623 @code{gdm-service-type}}), screen lockers, a network management tool
14624 (@pxref{Networking Services, @code{network-manager-service-type}}), energy and color
14625 management services, the @code{elogind} login and seat manager, the
14626 Polkit privilege service, the GeoClue location service, the
14627 AccountsService daemon that allows authorized users change system
14628 passwords, an NTP client (@pxref{Networking Services}), the Avahi
14629 daemon, and has the name service switch service configured to be able to
14630 use @code{nss-mdns} (@pxref{Name Service Switch, mDNS}).
14633 The @var{%desktop-services} variable can be used as the @code{services}
14634 field of an @code{operating-system} declaration (@pxref{operating-system
14635 Reference, @code{services}}).
14637 Additionally, the @code{gnome-desktop-service-type},
14638 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
14639 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
14640 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
14641 services like the backlight adjustment helpers and the power management
14642 utilities are added to the system, extending @code{polkit} and @code{dbus}
14643 appropriately, allowing GNOME to operate with elevated privileges on a
14644 limited number of special-purpose system interfaces. Additionally,
14645 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
14646 metapackage to the system profile. Likewise, adding the Xfce service
14647 not only adds the @code{xfce} metapackage to the system profile, but it
14648 also gives the Thunar file manager the ability to open a ``root-mode''
14649 file management window, if the user authenticates using the
14650 administrator's password via the standard polkit graphical interface.
14651 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
14652 appropriately, allowing MATE to operate with elevated privileges on a
14653 limited number of special-purpose system interfaces. Additionally,
14654 adding a service of type @code{mate-desktop-service-type} adds the MATE
14655 metapackage to the system profile. ``Adding Enlightenment'' means that
14656 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
14657 are set as setuid, allowing Enlightenment's screen locker and other
14658 functionality to work as expetected.
14660 The desktop environments in Guix use the Xorg display server by
14661 default. If you'd like to use the newer display server protocol
14662 called Wayland, you need to use the @code{sddm-service} instead of
14663 GDM as the graphical login manager. You should then
14664 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
14665 also try starting GNOME on Wayland manually from a TTY with the
14666 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
14667 gnome-session``. Currently only GNOME has support for Wayland.
14669 @defvr {Scheme Variable} gnome-desktop-service-type
14670 This is the type of the service that adds the @uref{https://www.gnome.org,
14671 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
14672 object (see below.)
14674 This service adds the @code{gnome} package to the system profile, and extends
14675 polkit with the actions from @code{gnome-settings-daemon}.
14678 @deftp {Data Type} gnome-desktop-configuration
14679 Configuration record for the GNOME desktop environment.
14682 @item @code{gnome} (default: @code{gnome})
14683 The GNOME package to use.
14687 @defvr {Scheme Variable} xfce-desktop-service-type
14688 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
14689 desktop environment. Its value is an @code{xfce-desktop-configuration} object
14692 This service adds the @code{xfce} package to the system profile, and
14693 extends polkit with the ability for @code{thunar} to manipulate the file
14694 system as root from within a user session, after the user has authenticated
14695 with the administrator's password.
14698 @deftp {Data Type} xfce-desktop-configuration
14699 Configuration record for the Xfce desktop environment.
14702 @item @code{xfce} (default: @code{xfce})
14703 The Xfce package to use.
14707 @deffn {Scheme Variable} mate-desktop-service-type
14708 This is the type of the service that runs the @uref{https://mate-desktop.org/,
14709 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
14710 object (see below.)
14712 This service adds the @code{mate} package to the system
14713 profile, and extends polkit with the actions from
14714 @code{mate-settings-daemon}.
14717 @deftp {Data Type} mate-desktop-configuration
14718 Configuration record for the MATE desktop environment.
14721 @item @code{mate} (default: @code{mate})
14722 The MATE package to use.
14726 @deffn {Scheme Variable} enlightenment-desktop-service-type
14727 Return a service that adds the @code{enlightenment} package to the system
14728 profile, and extends dbus with actions from @code{efl}.
14731 @deftp {Data Type} enlightenment-desktop-service-configuration
14733 @item @code{enlightenment} (default: @code{enlightenment})
14734 The enlightenment package to use.
14738 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
14739 the default @code{%desktop-services} variable doesn't include any of
14740 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
14741 @code{%desktop-services} in the @code{services} field of your
14742 @code{operating-system}:
14745 (use-modules (gnu))
14746 (use-service-modules desktop)
14749 ;; cons* adds items to the list given as its last argument.
14750 (services (cons* (service gnome-desktop-service-type)
14751 (service xfce-desktop-service)
14752 %desktop-services))
14756 These desktop environments will then be available as options in the
14757 graphical login window.
14759 The actual service definitions included in @code{%desktop-services} and
14760 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
14761 are described below.
14763 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
14764 Return a service that runs the ``system bus'', using @var{dbus}, with
14765 support for @var{services}.
14767 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
14768 facility. Its system bus is used to allow system services to communicate
14769 and to be notified of system-wide events.
14771 @var{services} must be a list of packages that provide an
14772 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
14773 and policy files. For example, to allow avahi-daemon to use the system bus,
14774 @var{services} must be equal to @code{(list avahi)}.
14777 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
14778 Return a service that runs the @code{elogind} login and
14779 seat management daemon. @uref{https://github.com/elogind/elogind,
14780 Elogind} exposes a D-Bus interface that can be used to know which users
14781 are logged in, know what kind of sessions they have open, suspend the
14782 system, inhibit system suspend, reboot the system, and other tasks.
14784 Elogind handles most system-level power events for a computer, for
14785 example suspending the system when a lid is closed, or shutting it down
14786 when the power button is pressed.
14788 The @var{config} keyword argument specifies the configuration for
14789 elogind, and should be the result of an @code{(elogind-configuration
14790 (@var{parameter} @var{value})...)} invocation. Available parameters and
14791 their default values are:
14794 @item kill-user-processes?
14796 @item kill-only-users
14798 @item kill-exclude-users
14800 @item inhibit-delay-max-seconds
14802 @item handle-power-key
14804 @item handle-suspend-key
14806 @item handle-hibernate-key
14808 @item handle-lid-switch
14810 @item handle-lid-switch-docked
14812 @item power-key-ignore-inhibited?
14814 @item suspend-key-ignore-inhibited?
14816 @item hibernate-key-ignore-inhibited?
14818 @item lid-switch-ignore-inhibited?
14820 @item holdoff-timeout-seconds
14824 @item idle-action-seconds
14826 @item runtime-directory-size-percent
14828 @item runtime-directory-size
14832 @item suspend-state
14833 @code{("mem" "standby" "freeze")}
14836 @item hibernate-state
14838 @item hibernate-mode
14839 @code{("platform" "shutdown")}
14840 @item hybrid-sleep-state
14842 @item hybrid-sleep-mode
14843 @code{("suspend" "platform" "shutdown")}
14847 @deffn {Scheme Procedure} accountsservice-service @
14848 [#:accountsservice @var{accountsservice}]
14849 Return a service that runs AccountsService, a system service that can
14850 list available accounts, change their passwords, and so on.
14851 AccountsService integrates with PolicyKit to enable unprivileged users
14852 to acquire the capability to modify their system configuration.
14853 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
14854 accountsservice web site} for more information.
14856 The @var{accountsservice} keyword argument is the @code{accountsservice}
14857 package to expose as a service.
14860 @deffn {Scheme Procedure} polkit-service @
14861 [#:polkit @var{polkit}]
14862 Return a service that runs the
14863 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
14864 management service}, which allows system administrators to grant access to
14865 privileged operations in a structured way. By querying the Polkit service, a
14866 privileged system component can know when it should grant additional
14867 capabilities to ordinary users. For example, an ordinary user can be granted
14868 the capability to suspend the system if the user is logged in locally.
14871 @defvr {Scheme Variable} upower-service-type
14872 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
14873 system-wide monitor for power consumption and battery levels, with the given
14874 configuration settings.
14876 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
14877 notably used by GNOME.
14880 @deftp {Data Type} upower-configuration
14881 Data type representation the configuration for UPower.
14885 @item @code{upower} (default: @var{upower})
14886 Package to use for @code{upower}.
14888 @item @code{watts-up-pro?} (default: @code{#f})
14889 Enable the Watts Up Pro device.
14891 @item @code{poll-batteries?} (default: @code{#t})
14892 Enable polling the kernel for battery level changes.
14894 @item @code{ignore-lid?} (default: @code{#f})
14895 Ignore the lid state, this can be useful if it's incorrect on a device.
14897 @item @code{use-percentage-for-policy?} (default: @code{#f})
14898 Whether battery percentage based policy should be used. The default is to use
14899 the time left, change to @code{#t} to use the percentage.
14901 @item @code{percentage-low} (default: @code{10})
14902 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14903 at which the battery is considered low.
14905 @item @code{percentage-critical} (default: @code{3})
14906 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14907 at which the battery is considered critical.
14909 @item @code{percentage-action} (default: @code{2})
14910 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14911 at which action will be taken.
14913 @item @code{time-low} (default: @code{1200})
14914 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14915 seconds at which the battery is considered low.
14917 @item @code{time-critical} (default: @code{300})
14918 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14919 seconds at which the battery is considered critical.
14921 @item @code{time-action} (default: @code{120})
14922 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14923 seconds at which action will be taken.
14925 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
14926 The action taken when @code{percentage-action} or @code{time-action} is
14927 reached (depending on the configuration of @code{use-percentage-for-policy?}).
14929 Possible values are:
14939 @code{'hybrid-sleep}.
14945 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
14946 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
14947 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
14948 notifications and ways to mount/unmount disks. Programs that talk to UDisks
14949 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
14952 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
14953 Return a service that runs @command{colord}, a system service with a D-Bus
14954 interface to manage the color profiles of input and output devices such as
14955 screens and scanners. It is notably used by the GNOME Color Manager graphical
14956 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
14957 site} for more information.
14960 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
14961 Return a configuration allowing an application to access GeoClue
14962 location data. @var{name} is the Desktop ID of the application, without
14963 the @code{.desktop} part. If @var{allowed?} is true, the application
14964 will have access to location information by default. The boolean
14965 @var{system?} value indicates whether an application is a system component
14966 or not. Finally @var{users} is a list of UIDs of all users for which
14967 this application is allowed location info access. An empty users list
14968 means that all users are allowed.
14971 @defvr {Scheme Variable} %standard-geoclue-applications
14972 The standard list of well-known GeoClue application configurations,
14973 granting authority to the GNOME date-and-time utility to ask for the
14974 current location in order to set the time zone, and allowing the
14975 IceCat and Epiphany web browsers to request location information.
14976 IceCat and Epiphany both query the user before allowing a web page to
14977 know the user's location.
14980 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
14981 [#:whitelist '()] @
14982 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
14983 [#:submit-data? #f]
14984 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
14985 [#:submission-nick "geoclue"] @
14986 [#:applications %standard-geoclue-applications]
14987 Return a service that runs the GeoClue location service. This service
14988 provides a D-Bus interface to allow applications to request access to a
14989 user's physical location, and optionally to add information to online
14990 location databases. See
14991 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
14992 web site} for more information.
14995 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
14996 [@w{#:auto-enable? #f}]
14997 Return a service that runs the @command{bluetoothd} daemon, which
14998 manages all the Bluetooth devices and provides a number of D-Bus
14999 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
15000 powered automatically at boot, which can be useful when using a
15001 bluetooth keyboard or mouse.
15003 Users need to be in the @code{lp} group to access the D-Bus service.
15006 @node Sound Services
15007 @subsection Sound Services
15009 @cindex sound support
15011 @cindex PulseAudio, sound support
15013 The @code{(gnu services sound)} module provides a service to configure the
15014 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
15015 preferred ALSA output driver.
15017 @deffn {Scheme Variable} alsa-service-type
15018 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
15019 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
15020 configuration file. The value for this type is a @command{alsa-configuration}
15021 record as in this example:
15024 (service alsa-service-type)
15027 See below for details about @code{alsa-configuration}.
15030 @deftp {Data Type} alsa-configuration
15031 Data type representing the configuration for @code{alsa-service}.
15034 @item @code{alsa-plugins} (default: @var{alsa-plugins})
15035 @code{alsa-plugins} package to use.
15037 @item @code{pulseaudio?} (default: @var{#t})
15038 Whether ALSA applications should transparently be made to use the
15039 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
15041 Using PulseAudio allows you to run several sound-producing applications
15042 at the same time and to individual control them @i{via}
15043 @command{pavucontrol}, among other things.
15045 @item @code{extra-options} (default: @var{""})
15046 String to append to the @file{/etc/asound.conf} file.
15051 Individual users who want to override the system configuration of ALSA can do
15052 it with the @file{~/.asoundrc} file:
15055 # In guix, we have to specify the absolute path for plugins.
15057 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
15060 # Routing ALSA to jack:
15061 # <http://jackaudio.org/faq/routing_alsa.html>.
15065 0 system:playback_1
15066 1 system:playback_2
15083 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
15087 @node Database Services
15088 @subsection Database Services
15092 The @code{(gnu services databases)} module provides the following services.
15094 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
15095 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
15096 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
15097 Return a service that runs @var{postgresql}, the PostgreSQL database
15100 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
15101 creates a database cluster with @var{locale} as the default
15102 locale, stored in @var{data-directory}. It then listens on @var{port}.
15104 @cindex postgresql extension-packages
15105 Additional extensions are loaded from packages listed in
15106 @var{extension-packages}. Extensions are available at runtime. For instance,
15107 to create a geographic database using the @code{postgis} extension, a user can
15108 configure the postgresql-service as in this example:
15112 (use-package-modules databases geo)
15116 ;; postgresql is required to run `psql' but postgis is not required for
15117 ;; proper operation.
15118 (packages (cons* postgresql %base-packages))
15121 (postgresql-service #:extension-packages (list postgis))
15125 Then the extension becomes visible and you can initialise an empty geographic
15126 database in this way:
15130 > create database postgistest;
15131 > \connect postgistest;
15132 > create extension postgis;
15133 > create extension postgis_topology;
15136 There is no need to add this field for contrib extensions such as hstore or
15137 dblink as they are already loadable by postgresql. This field is only
15138 required to add extensions provided by other packages.
15141 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
15142 Return a service that runs @command{mysqld}, the MySQL or MariaDB
15145 The optional @var{config} argument specifies the configuration for
15146 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
15149 @deftp {Data Type} mysql-configuration
15150 Data type representing the configuration of @var{mysql-service}.
15153 @item @code{mysql} (default: @var{mariadb})
15154 Package object of the MySQL database server, can be either @var{mariadb}
15157 For MySQL, a temporary root password will be displayed at activation time.
15158 For MariaDB, the root password is empty.
15160 @item @code{port} (default: @code{3306})
15161 TCP port on which the database server listens for incoming connections.
15165 @defvr {Scheme Variable} memcached-service-type
15166 This is the service type for the @uref{https://memcached.org/,
15167 Memcached} service, which provides a distributed in memory cache. The
15168 value for the service type is a @code{memcached-configuration} object.
15172 (service memcached-service-type)
15175 @deftp {Data Type} memcached-configuration
15176 Data type representing the configuration of memcached.
15179 @item @code{memcached} (default: @code{memcached})
15180 The Memcached package to use.
15182 @item @code{interfaces} (default: @code{'("0.0.0.0")})
15183 Network interfaces on which to listen.
15185 @item @code{tcp-port} (default: @code{11211})
15186 Port on which to accept connections on,
15188 @item @code{udp-port} (default: @code{11211})
15189 Port on which to accept UDP connections on, a value of 0 will disable
15190 listening on a UDP socket.
15192 @item @code{additional-options} (default: @code{'()})
15193 Additional command line options to pass to @code{memcached}.
15197 @defvr {Scheme Variable} mongodb-service-type
15198 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
15199 The value for the service type is a @code{mongodb-configuration} object.
15203 (service mongodb-service-type)
15206 @deftp {Data Type} mongodb-configuration
15207 Data type representing the configuration of mongodb.
15210 @item @code{mongodb} (default: @code{mongodb})
15211 The MongoDB package to use.
15213 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
15214 The configuration file for MongoDB.
15216 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
15217 This value is used to create the directory, so that it exists and is
15218 owned by the mongodb user. It should match the data-directory which
15219 MongoDB is configured to use through the configuration file.
15223 @defvr {Scheme Variable} redis-service-type
15224 This is the service type for the @uref{https://redis.io/, Redis}
15225 key/value store, whose value is a @code{redis-configuration} object.
15228 @deftp {Data Type} redis-configuration
15229 Data type representing the configuration of redis.
15232 @item @code{redis} (default: @code{redis})
15233 The Redis package to use.
15235 @item @code{bind} (default: @code{"127.0.0.1"})
15236 Network interface on which to listen.
15238 @item @code{port} (default: @code{6379})
15239 Port on which to accept connections on, a value of 0 will disable
15240 listening on a TCP socket.
15242 @item @code{working-directory} (default: @code{"/var/lib/redis"})
15243 Directory in which to store the database and related files.
15247 @node Mail Services
15248 @subsection Mail Services
15252 The @code{(gnu services mail)} module provides Guix service definitions
15253 for email services: IMAP, POP3, and LMTP servers, as well as mail
15254 transport agents (MTAs). Lots of acronyms! These services are detailed
15255 in the subsections below.
15257 @subsubheading Dovecot Service
15259 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
15260 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
15263 By default, Dovecot does not need much configuration; the default
15264 configuration object created by @code{(dovecot-configuration)} will
15265 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
15266 certificate will be generated for TLS-protected connections, though
15267 Dovecot will also listen on cleartext ports by default. There are a
15268 number of options, though, which mail administrators might need to change,
15269 and as is the case with other services, Guix allows the system
15270 administrator to specify these parameters via a uniform Scheme interface.
15272 For example, to specify that mail is located at @code{maildir~/.mail},
15273 one would instantiate the Dovecot service like this:
15276 (dovecot-service #:config
15277 (dovecot-configuration
15278 (mail-location "maildir:~/.mail")))
15281 The available configuration parameters follow. Each parameter
15282 definition is preceded by its type; for example, @samp{string-list foo}
15283 indicates that the @code{foo} parameter should be specified as a list of
15284 strings. There is also a way to specify the configuration as a string,
15285 if you have an old @code{dovecot.conf} file that you want to port over
15286 from some other system; see the end for more details.
15288 @c The following documentation was initially generated by
15289 @c (generate-documentation) in (gnu services mail). Manually maintained
15290 @c documentation is better, so we shouldn't hesitate to edit below as
15291 @c needed. However if the change you want to make to this documentation
15292 @c can be done in an automated way, it's probably easier to change
15293 @c (generate-documentation) than to make it below and have to deal with
15294 @c the churn as dovecot updates.
15296 Available @code{dovecot-configuration} fields are:
15298 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
15299 The dovecot package.
15302 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
15303 A list of IPs or hosts where to listen for connections. @samp{*}
15304 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
15305 interfaces. If you want to specify non-default ports or anything more
15306 complex, customize the address and port fields of the
15307 @samp{inet-listener} of the specific services you are interested in.
15310 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
15311 List of protocols we want to serve. Available protocols include
15312 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
15314 Available @code{protocol-configuration} fields are:
15316 @deftypevr {@code{protocol-configuration} parameter} string name
15317 The name of the protocol.
15320 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
15321 UNIX socket path to the master authentication server to find users.
15322 This is used by imap (for shared users) and lda.
15323 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
15326 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
15327 Space separated list of plugins to load.
15330 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
15331 Maximum number of IMAP connections allowed for a user from each IP
15332 address. NOTE: The username is compared case-sensitively.
15333 Defaults to @samp{10}.
15338 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
15339 List of services to enable. Available services include @samp{imap},
15340 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
15343 Available @code{service-configuration} fields are:
15345 @deftypevr {@code{service-configuration} parameter} string kind
15346 The service kind. Valid values include @code{director},
15347 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
15348 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
15349 @code{tcpwrap}, @code{quota-warning}, or anything else.
15352 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
15353 Listeners for the service. A listener is either a
15354 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
15355 an @code{inet-listener-configuration}.
15356 Defaults to @samp{()}.
15358 Available @code{unix-listener-configuration} fields are:
15360 @deftypevr {@code{unix-listener-configuration} parameter} string path
15361 Path to the file, relative to @code{base-dir} field. This is also used as
15365 @deftypevr {@code{unix-listener-configuration} parameter} string mode
15366 The access mode for the socket.
15367 Defaults to @samp{"0600"}.
15370 @deftypevr {@code{unix-listener-configuration} parameter} string user
15371 The user to own the socket.
15372 Defaults to @samp{""}.
15375 @deftypevr {@code{unix-listener-configuration} parameter} string group
15376 The group to own the socket.
15377 Defaults to @samp{""}.
15381 Available @code{fifo-listener-configuration} fields are:
15383 @deftypevr {@code{fifo-listener-configuration} parameter} string path
15384 Path to the file, relative to @code{base-dir} field. This is also used as
15388 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
15389 The access mode for the socket.
15390 Defaults to @samp{"0600"}.
15393 @deftypevr {@code{fifo-listener-configuration} parameter} string user
15394 The user to own the socket.
15395 Defaults to @samp{""}.
15398 @deftypevr {@code{fifo-listener-configuration} parameter} string group
15399 The group to own the socket.
15400 Defaults to @samp{""}.
15404 Available @code{inet-listener-configuration} fields are:
15406 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
15407 The protocol to listen for.
15410 @deftypevr {@code{inet-listener-configuration} parameter} string address
15411 The address on which to listen, or empty for all addresses.
15412 Defaults to @samp{""}.
15415 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
15416 The port on which to listen.
15419 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
15420 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
15422 Defaults to @samp{#t}.
15427 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
15428 Maximum number of simultaneous client connections per process. Once
15429 this number of connections is received, the next incoming connection
15430 will prompt Dovecot to spawn another process. If set to 0,
15431 @code{default-client-limit} is used instead.
15433 Defaults to @samp{0}.
15437 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
15438 Number of connections to handle before starting a new process.
15439 Typically the only useful values are 0 (unlimited) or 1. 1 is more
15440 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
15441 Defaults to @samp{1}.
15445 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
15446 Maximum number of processes that can exist for this service. If set to
15447 0, @code{default-process-limit} is used instead.
15449 Defaults to @samp{0}.
15453 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
15454 Number of processes to always keep waiting for more connections.
15455 Defaults to @samp{0}.
15458 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
15459 If you set @samp{service-count 0}, you probably need to grow
15461 Defaults to @samp{256000000}.
15466 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
15467 Dict configuration, as created by the @code{dict-configuration}
15470 Available @code{dict-configuration} fields are:
15472 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
15473 A list of key-value pairs that this dict should hold.
15474 Defaults to @samp{()}.
15479 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
15480 A list of passdb configurations, each one created by the
15481 @code{passdb-configuration} constructor.
15483 Available @code{passdb-configuration} fields are:
15485 @deftypevr {@code{passdb-configuration} parameter} string driver
15486 The driver that the passdb should use. Valid values include
15487 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
15489 Defaults to @samp{"pam"}.
15492 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
15493 Space separated list of arguments to the passdb driver.
15494 Defaults to @samp{""}.
15499 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
15500 List of userdb configurations, each one created by the
15501 @code{userdb-configuration} constructor.
15503 Available @code{userdb-configuration} fields are:
15505 @deftypevr {@code{userdb-configuration} parameter} string driver
15506 The driver that the userdb should use. Valid values include
15507 @samp{passwd} and @samp{static}.
15508 Defaults to @samp{"passwd"}.
15511 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
15512 Space separated list of arguments to the userdb driver.
15513 Defaults to @samp{""}.
15516 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
15517 Override fields from passwd.
15518 Defaults to @samp{()}.
15523 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
15524 Plug-in configuration, created by the @code{plugin-configuration}
15528 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
15529 List of namespaces. Each item in the list is created by the
15530 @code{namespace-configuration} constructor.
15532 Available @code{namespace-configuration} fields are:
15534 @deftypevr {@code{namespace-configuration} parameter} string name
15535 Name for this namespace.
15538 @deftypevr {@code{namespace-configuration} parameter} string type
15539 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
15540 Defaults to @samp{"private"}.
15543 @deftypevr {@code{namespace-configuration} parameter} string separator
15544 Hierarchy separator to use. You should use the same separator for
15545 all namespaces or some clients get confused. @samp{/} is usually a good
15546 one. The default however depends on the underlying mail storage
15548 Defaults to @samp{""}.
15551 @deftypevr {@code{namespace-configuration} parameter} string prefix
15552 Prefix required to access this namespace. This needs to be
15553 different for all namespaces. For example @samp{Public/}.
15554 Defaults to @samp{""}.
15557 @deftypevr {@code{namespace-configuration} parameter} string location
15558 Physical location of the mailbox. This is in the same format as
15559 mail_location, which is also the default for it.
15560 Defaults to @samp{""}.
15563 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
15564 There can be only one INBOX, and this setting defines which
15566 Defaults to @samp{#f}.
15569 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
15570 If namespace is hidden, it's not advertised to clients via NAMESPACE
15571 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
15572 useful when converting from another server with different namespaces
15573 which you want to deprecate but still keep working. For example you can
15574 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
15576 Defaults to @samp{#f}.
15579 @deftypevr {@code{namespace-configuration} parameter} boolean list?
15580 Show the mailboxes under this namespace with the LIST command. This
15581 makes the namespace visible for clients that do not support the NAMESPACE
15582 extension. The special @code{children} value lists child mailboxes, but
15583 hides the namespace prefix.
15584 Defaults to @samp{#t}.
15587 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
15588 Namespace handles its own subscriptions. If set to @code{#f}, the
15589 parent namespace handles them. The empty prefix should always have this
15591 Defaults to @samp{#t}.
15594 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
15595 List of predefined mailboxes in this namespace.
15596 Defaults to @samp{()}.
15598 Available @code{mailbox-configuration} fields are:
15600 @deftypevr {@code{mailbox-configuration} parameter} string name
15601 Name for this mailbox.
15604 @deftypevr {@code{mailbox-configuration} parameter} string auto
15605 @samp{create} will automatically create this mailbox.
15606 @samp{subscribe} will both create and subscribe to the mailbox.
15607 Defaults to @samp{"no"}.
15610 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
15611 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
15612 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
15613 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
15614 Defaults to @samp{()}.
15621 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
15622 Base directory where to store runtime data.
15623 Defaults to @samp{"/var/run/dovecot/"}.
15626 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
15627 Greeting message for clients.
15628 Defaults to @samp{"Dovecot ready."}.
15631 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
15632 List of trusted network ranges. Connections from these IPs are
15633 allowed to override their IP addresses and ports (for logging and for
15634 authentication checks). @samp{disable-plaintext-auth} is also ignored
15635 for these networks. Typically you would specify your IMAP proxy servers
15637 Defaults to @samp{()}.
15640 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
15641 List of login access check sockets (e.g.@: tcpwrap).
15642 Defaults to @samp{()}.
15645 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
15646 Show more verbose process titles (in ps). Currently shows user name
15647 and IP address. Useful for seeing who is actually using the IMAP
15648 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
15650 Defaults to @samp{#f}.
15653 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
15654 Should all processes be killed when Dovecot master process shuts down.
15655 Setting this to @code{#f} means that Dovecot can be upgraded without
15656 forcing existing client connections to close (although that could also
15657 be a problem if the upgrade is e.g.@: due to a security fix).
15658 Defaults to @samp{#t}.
15661 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
15662 If non-zero, run mail commands via this many connections to doveadm
15663 server, instead of running them directly in the same process.
15664 Defaults to @samp{0}.
15667 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
15668 UNIX socket or host:port used for connecting to doveadm server.
15669 Defaults to @samp{"doveadm-server"}.
15672 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
15673 List of environment variables that are preserved on Dovecot startup
15674 and passed down to all of its child processes. You can also give
15675 key=value pairs to always set specific settings.
15678 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
15679 Disable LOGIN command and all other plaintext authentications unless
15680 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
15681 matches the local IP (i.e.@: you're connecting from the same computer),
15682 the connection is considered secure and plaintext authentication is
15683 allowed. See also ssl=required setting.
15684 Defaults to @samp{#t}.
15687 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
15688 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
15689 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
15690 for caching to be used.
15691 Defaults to @samp{0}.
15694 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
15695 Time to live for cached data. After TTL expires the cached record
15696 is no longer used, *except* if the main database lookup returns internal
15697 failure. We also try to handle password changes automatically: If
15698 user's previous authentication was successful, but this one wasn't, the
15699 cache isn't used. For now this works only with plaintext
15701 Defaults to @samp{"1 hour"}.
15704 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
15705 TTL for negative hits (user not found, password mismatch).
15706 0 disables caching them completely.
15707 Defaults to @samp{"1 hour"}.
15710 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
15711 List of realms for SASL authentication mechanisms that need them.
15712 You can leave it empty if you don't want to support multiple realms.
15713 Many clients simply use the first one listed here, so keep the default
15715 Defaults to @samp{()}.
15718 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
15719 Default realm/domain to use if none was specified. This is used for
15720 both SASL realms and appending @@domain to username in plaintext
15722 Defaults to @samp{""}.
15725 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
15726 List of allowed characters in username. If the user-given username
15727 contains a character not listed in here, the login automatically fails.
15728 This is just an extra check to make sure user can't exploit any
15729 potential quote escaping vulnerabilities with SQL/LDAP databases. If
15730 you want to allow all characters, set this value to empty.
15731 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
15734 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
15735 Username character translations before it's looked up from
15736 databases. The value contains series of from -> to characters. For
15737 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
15738 translated to @samp{@@}.
15739 Defaults to @samp{""}.
15742 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
15743 Username formatting before it's looked up from databases. You can
15744 use the standard variables here, e.g.@: %Lu would lowercase the username,
15745 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
15746 change the @samp{@@} into @samp{-AT-}. This translation is done after
15747 @samp{auth-username-translation} changes.
15748 Defaults to @samp{"%Lu"}.
15751 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
15752 If you want to allow master users to log in by specifying the master
15753 username within the normal username string (i.e.@: not using SASL
15754 mechanism's support for it), you can specify the separator character
15755 here. The format is then <username><separator><master username>.
15756 UW-IMAP uses @samp{*} as the separator, so that could be a good
15758 Defaults to @samp{""}.
15761 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
15762 Username to use for users logging in with ANONYMOUS SASL
15764 Defaults to @samp{"anonymous"}.
15767 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
15768 Maximum number of dovecot-auth worker processes. They're used to
15769 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
15770 They're automatically created and destroyed as needed.
15771 Defaults to @samp{30}.
15774 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
15775 Host name to use in GSSAPI principal names. The default is to use
15776 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
15777 allow all keytab entries.
15778 Defaults to @samp{""}.
15781 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
15782 Kerberos keytab to use for the GSSAPI mechanism. Will use the
15783 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
15784 need to change the auth service to run as root to be able to read this
15786 Defaults to @samp{""}.
15789 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
15790 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
15791 and @samp{ntlm-auth} helper.
15792 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
15793 Defaults to @samp{#f}.
15796 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
15797 Path for Samba's @samp{ntlm-auth} helper binary.
15798 Defaults to @samp{"/usr/bin/ntlm_auth"}.
15801 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
15802 Time to delay before replying to failed authentications.
15803 Defaults to @samp{"2 secs"}.
15806 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
15807 Require a valid SSL client certificate or the authentication
15809 Defaults to @samp{#f}.
15812 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
15813 Take the username from client's SSL certificate, using
15814 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
15816 Defaults to @samp{#f}.
15819 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
15820 List of wanted authentication mechanisms. Supported mechanisms are:
15821 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
15822 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
15823 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
15824 @samp{disable-plaintext-auth} setting.
15827 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
15828 List of IPs or hostnames to all director servers, including ourself.
15829 Ports can be specified as ip:port. The default port is the same as what
15830 director service's @samp{inet-listener} is using.
15831 Defaults to @samp{()}.
15834 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
15835 List of IPs or hostnames to all backend mail servers. Ranges are
15836 allowed too, like 10.0.0.10-10.0.0.30.
15837 Defaults to @samp{()}.
15840 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
15841 How long to redirect users to a specific server after it no longer
15842 has any connections.
15843 Defaults to @samp{"15 min"}.
15846 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
15847 How the username is translated before being hashed. Useful values
15848 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
15849 are shared within domain.
15850 Defaults to @samp{"%Lu"}.
15853 @deftypevr {@code{dovecot-configuration} parameter} string log-path
15854 Log file to use for error messages. @samp{syslog} logs to syslog,
15855 @samp{/dev/stderr} logs to stderr.
15856 Defaults to @samp{"syslog"}.
15859 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
15860 Log file to use for informational messages. Defaults to
15862 Defaults to @samp{""}.
15865 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
15866 Log file to use for debug messages. Defaults to
15867 @samp{info-log-path}.
15868 Defaults to @samp{""}.
15871 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
15872 Syslog facility to use if you're logging to syslog. Usually if you
15873 don't want to use @samp{mail}, you'll use local0..local7. Also other
15874 standard facilities are supported.
15875 Defaults to @samp{"mail"}.
15878 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
15879 Log unsuccessful authentication attempts and the reasons why they
15881 Defaults to @samp{#f}.
15884 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
15885 In case of password mismatches, log the attempted password. Valid
15886 values are no, plain and sha1. sha1 can be useful for detecting brute
15887 force password attempts vs. user simply trying the same password over
15888 and over again. You can also truncate the value to n chars by appending
15889 ":n" (e.g.@: sha1:6).
15890 Defaults to @samp{"no"}.
15893 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
15894 Even more verbose logging for debugging purposes. Shows for example
15896 Defaults to @samp{#f}.
15899 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
15900 In case of password mismatches, log the passwords and used scheme so
15901 the problem can be debugged. Enabling this also enables
15903 Defaults to @samp{#f}.
15906 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
15907 Enable mail process debugging. This can help you figure out why
15908 Dovecot isn't finding your mails.
15909 Defaults to @samp{#f}.
15912 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
15913 Show protocol level SSL errors.
15914 Defaults to @samp{#f}.
15917 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
15918 Prefix for each line written to log file. % codes are in
15919 strftime(3) format.
15920 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
15923 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
15924 List of elements we want to log. The elements which have a
15925 non-empty variable value are joined together to form a comma-separated
15929 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
15930 Login log format. %s contains @samp{login-log-format-elements}
15931 string, %$ contains the data we want to log.
15932 Defaults to @samp{"%$: %s"}.
15935 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
15936 Log prefix for mail processes. See doc/wiki/Variables.txt for list
15937 of possible variables you can use.
15938 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
15941 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
15942 Format to use for logging mail deliveries. You can use variables:
15945 Delivery status message (e.g.@: @samp{saved to INBOX})
15957 Defaults to @samp{"msgid=%m: %$"}.
15960 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
15961 Location for users' mailboxes. The default is empty, which means
15962 that Dovecot tries to find the mailboxes automatically. This won't work
15963 if the user doesn't yet have any mail, so you should explicitly tell
15964 Dovecot the full location.
15966 If you're using mbox, giving a path to the INBOX
15967 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
15968 where the other mailboxes are kept. This is called the "root mail
15969 directory", and it must be the first path given in the
15970 @samp{mail-location} setting.
15972 There are a few special variables you can use, eg.:
15978 user part in user@@domain, same as %u if there's no domain
15980 domain part in user@@domain, empty if there's no domain
15985 See doc/wiki/Variables.txt for full list. Some examples:
15987 @item maildir:~/Maildir
15988 @item mbox:~/mail:INBOX=/var/mail/%u
15989 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
15991 Defaults to @samp{""}.
15994 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
15995 System user and group used to access mails. If you use multiple,
15996 userdb can override these by returning uid or gid fields. You can use
15997 either numbers or names. <doc/wiki/UserIds.txt>.
15998 Defaults to @samp{""}.
16001 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
16003 Defaults to @samp{""}.
16006 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
16007 Group to enable temporarily for privileged operations. Currently
16008 this is used only with INBOX when either its initial creation or
16009 dotlocking fails. Typically this is set to "mail" to give access to
16011 Defaults to @samp{""}.
16014 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
16015 Grant access to these supplementary groups for mail processes.
16016 Typically these are used to set up access to shared mailboxes. Note
16017 that it may be dangerous to set these if users can create
16018 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
16019 could allow a user to delete others' mailboxes, or ln -s
16020 /secret/shared/box ~/mail/mybox would allow reading it).
16021 Defaults to @samp{""}.
16024 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
16025 Allow full file system access to clients. There's no access checks
16026 other than what the operating system does for the active UID/GID. It
16027 works with both maildir and mboxes, allowing you to prefix mailboxes
16028 names with e.g.@: /path/ or ~user/.
16029 Defaults to @samp{#f}.
16032 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
16033 Don't use mmap() at all. This is required if you store indexes to
16034 shared file systems (NFS or clustered file system).
16035 Defaults to @samp{#f}.
16038 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
16039 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
16040 supports @samp{O_EXCL} since version 3, so this should be safe to use
16041 nowadays by default.
16042 Defaults to @samp{#t}.
16045 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
16046 When to use fsync() or fdatasync() calls:
16049 Whenever necessary to avoid losing important data
16051 Useful with e.g.@: NFS when write()s are delayed
16053 Never use it (best performance, but crashes can lose data).
16055 Defaults to @samp{"optimized"}.
16058 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
16059 Mail storage exists in NFS. Set this to yes to make Dovecot flush
16060 NFS caches whenever needed. If you're using only a single mail server
16062 Defaults to @samp{#f}.
16065 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
16066 Mail index files also exist in NFS. Setting this to yes requires
16067 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
16068 Defaults to @samp{#f}.
16071 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
16072 Locking method for index files. Alternatives are fcntl, flock and
16073 dotlock. Dotlocking uses some tricks which may create more disk I/O
16074 than other locking methods. NFS users: flock doesn't work, remember to
16075 change @samp{mmap-disable}.
16076 Defaults to @samp{"fcntl"}.
16079 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
16080 Directory in which LDA/LMTP temporarily stores incoming mails >128
16082 Defaults to @samp{"/tmp"}.
16085 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
16086 Valid UID range for users. This is mostly to make sure that users can't
16087 log in as daemons or other system users. Note that denying root logins is
16088 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
16090 Defaults to @samp{500}.
16093 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
16095 Defaults to @samp{0}.
16098 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
16099 Valid GID range for users. Users having non-valid GID as primary group ID
16100 aren't allowed to log in. If user belongs to supplementary groups with
16101 non-valid GIDs, those groups are not set.
16102 Defaults to @samp{1}.
16105 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
16107 Defaults to @samp{0}.
16110 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
16111 Maximum allowed length for mail keyword name. It's only forced when
16112 trying to create new keywords.
16113 Defaults to @samp{50}.
16116 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
16117 List of directories under which chrooting is allowed for mail
16118 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
16119 too). This setting doesn't affect @samp{login-chroot}
16120 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
16121 "/./" in home dirs are ignored. WARNING: Never add directories here
16122 which local users can modify, that may lead to root exploit. Usually
16123 this should be done only if you don't allow shell access for users.
16124 <doc/wiki/Chrooting.txt>.
16125 Defaults to @samp{()}.
16128 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
16129 Default chroot directory for mail processes. This can be overridden
16130 for specific users in user database by giving /./ in user's home
16131 directory (e.g.@: /home/./user chroots into /home). Note that usually
16132 there is no real need to do chrooting, Dovecot doesn't allow users to
16133 access files outside their mail directory anyway. If your home
16134 directories are prefixed with the chroot directory, append "/."@: to
16135 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
16136 Defaults to @samp{""}.
16139 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
16140 UNIX socket path to master authentication server to find users.
16141 This is used by imap (for shared users) and lda.
16142 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16145 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
16146 Directory where to look up mail plugins.
16147 Defaults to @samp{"/usr/lib/dovecot"}.
16150 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
16151 List of plugins to load for all services. Plugins specific to IMAP,
16152 LDA, etc.@: are added to this list in their own .conf files.
16153 Defaults to @samp{()}.
16156 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
16157 The minimum number of mails in a mailbox before updates are done to
16158 cache file. This allows optimizing Dovecot's behavior to do less disk
16159 writes at the cost of more disk reads.
16160 Defaults to @samp{0}.
16163 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
16164 When IDLE command is running, mailbox is checked once in a while to
16165 see if there are any new mails or other changes. This setting defines
16166 the minimum time to wait between those checks. Dovecot can also use
16167 dnotify, inotify and kqueue to find out immediately when changes
16169 Defaults to @samp{"30 secs"}.
16172 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
16173 Save mails with CR+LF instead of plain LF. This makes sending those
16174 mails take less CPU, especially with sendfile() syscall with Linux and
16175 FreeBSD. But it also creates a bit more disk I/O which may just make it
16176 slower. Also note that if other software reads the mboxes/maildirs,
16177 they may handle the extra CRs wrong and cause problems.
16178 Defaults to @samp{#f}.
16181 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
16182 By default LIST command returns all entries in maildir beginning
16183 with a dot. Enabling this option makes Dovecot return only entries
16184 which are directories. This is done by stat()ing each entry, so it
16185 causes more disk I/O.
16186 (For systems setting struct @samp{dirent->d_type} this check is free
16187 and it's done always regardless of this setting).
16188 Defaults to @samp{#f}.
16191 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
16192 When copying a message, do it with hard links whenever possible.
16193 This makes the performance much better, and it's unlikely to have any
16195 Defaults to @samp{#t}.
16198 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
16199 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
16200 directory only when its mtime changes unexpectedly or when we can't find
16201 the mail otherwise.
16202 Defaults to @samp{#f}.
16205 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
16206 Which locking methods to use for locking mbox. There are four
16211 Create <mailbox>.lock file. This is the oldest and most NFS-safe
16212 solution. If you want to use /var/mail/ like directory, the users will
16213 need write access to that directory.
16215 Same as dotlock, but if it fails because of permissions or because there
16216 isn't enough disk space, just skip it.
16218 Use this if possible. Works with NFS too if lockd is used.
16220 May not exist in all systems. Doesn't work with NFS.
16222 May not exist in all systems. Doesn't work with NFS.
16225 You can use multiple locking methods; if you do the order they're declared
16226 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
16227 locking methods as well. Some operating systems don't allow using some of
16228 them simultaneously.
16231 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
16235 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
16236 Maximum time to wait for lock (all of them) before aborting.
16237 Defaults to @samp{"5 mins"}.
16240 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
16241 If dotlock exists but the mailbox isn't modified in any way,
16242 override the lock file after this much time.
16243 Defaults to @samp{"2 mins"}.
16246 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
16247 When mbox changes unexpectedly we have to fully read it to find out
16248 what changed. If the mbox is large this can take a long time. Since
16249 the change is usually just a newly appended mail, it'd be faster to
16250 simply read the new mails. If this setting is enabled, Dovecot does
16251 this but still safely fallbacks to re-reading the whole mbox file
16252 whenever something in mbox isn't how it's expected to be. The only real
16253 downside to this setting is that if some other MUA changes message
16254 flags, Dovecot doesn't notice it immediately. Note that a full sync is
16255 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
16256 Defaults to @samp{#t}.
16259 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
16260 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
16261 EXAMINE, EXPUNGE or CHECK commands. If this is set,
16262 @samp{mbox-dirty-syncs} is ignored.
16263 Defaults to @samp{#f}.
16266 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
16267 Delay writing mbox headers until doing a full write sync (EXPUNGE
16268 and CHECK commands and when closing the mailbox). This is especially
16269 useful for POP3 where clients often delete all mails. The downside is
16270 that our changes aren't immediately visible to other MUAs.
16271 Defaults to @samp{#t}.
16274 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
16275 If mbox size is smaller than this (e.g.@: 100k), don't write index
16276 files. If an index file already exists it's still read, just not
16278 Defaults to @samp{0}.
16281 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
16282 Maximum dbox file size until it's rotated.
16283 Defaults to @samp{10000000}.
16286 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
16287 Maximum dbox file age until it's rotated. Typically in days. Day
16288 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
16290 Defaults to @samp{"1d"}.
16293 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
16294 When creating new mdbox files, immediately preallocate their size to
16295 @samp{mdbox-rotate-size}. This setting currently works only in Linux
16296 with some file systems (ext4, xfs).
16297 Defaults to @samp{#f}.
16300 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
16301 sdbox and mdbox support saving mail attachments to external files,
16302 which also allows single instance storage for them. Other backends
16303 don't support this for now.
16305 WARNING: This feature hasn't been tested much yet. Use at your own risk.
16307 Directory root where to store mail attachments. Disabled, if empty.
16308 Defaults to @samp{""}.
16311 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
16312 Attachments smaller than this aren't saved externally. It's also
16313 possible to write a plugin to disable saving specific attachments
16315 Defaults to @samp{128000}.
16318 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
16319 File system backend to use for saving attachments:
16322 No SiS done by Dovecot (but this might help FS's own deduplication)
16324 SiS with immediate byte-by-byte comparison during saving
16325 @item sis-queue posix
16326 SiS with delayed comparison and deduplication.
16328 Defaults to @samp{"sis posix"}.
16331 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
16332 Hash format to use in attachment filenames. You can add any text and
16333 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
16334 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
16335 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
16336 Defaults to @samp{"%@{sha1@}"}.
16339 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
16341 Defaults to @samp{100}.
16344 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
16346 Defaults to @samp{1000}.
16349 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
16350 Default VSZ (virtual memory size) limit for service processes.
16351 This is mainly intended to catch and kill processes that leak memory
16352 before they eat up everything.
16353 Defaults to @samp{256000000}.
16356 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
16357 Login user is internally used by login processes. This is the most
16358 untrusted user in Dovecot system. It shouldn't have access to anything
16360 Defaults to @samp{"dovenull"}.
16363 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
16364 Internal user is used by unprivileged processes. It should be
16365 separate from login user, so that login processes can't disturb other
16367 Defaults to @samp{"dovecot"}.
16370 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
16371 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
16372 Defaults to @samp{"required"}.
16375 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
16376 PEM encoded X.509 SSL/TLS certificate (public key).
16377 Defaults to @samp{"</etc/dovecot/default.pem"}.
16380 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
16381 PEM encoded SSL/TLS private key. The key is opened before
16382 dropping root privileges, so keep the key file unreadable by anyone but
16384 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
16387 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
16388 If key file is password protected, give the password here.
16389 Alternatively give it when starting dovecot with -p parameter. Since
16390 this file is often world-readable, you may want to place this setting
16391 instead to a different.
16392 Defaults to @samp{""}.
16395 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
16396 PEM encoded trusted certificate authority. Set this only if you
16397 intend to use @samp{ssl-verify-client-cert? #t}. The file should
16398 contain the CA certificate(s) followed by the matching
16399 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
16400 Defaults to @samp{""}.
16403 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
16404 Require that CRL check succeeds for client certificates.
16405 Defaults to @samp{#t}.
16408 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
16409 Request client to send a certificate. If you also want to require
16410 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
16411 Defaults to @samp{#f}.
16414 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
16415 Which field from certificate to use for username. commonName and
16416 x500UniqueIdentifier are the usual choices. You'll also need to set
16417 @samp{auth-ssl-username-from-cert? #t}.
16418 Defaults to @samp{"commonName"}.
16421 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
16422 Minimum SSL protocol version to accept.
16423 Defaults to @samp{"TLSv1"}.
16426 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
16427 SSL ciphers to use.
16428 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
16431 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
16432 SSL crypto device to use, for valid values run "openssl engine".
16433 Defaults to @samp{""}.
16436 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
16437 Address to use when sending rejection mails.
16438 %d expands to recipient domain.
16439 Defaults to @samp{"postmaster@@%d"}.
16442 @deftypevr {@code{dovecot-configuration} parameter} string hostname
16443 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
16444 and in LMTP replies. Default is the system's real hostname@@domain.
16445 Defaults to @samp{""}.
16448 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
16449 If user is over quota, return with temporary failure instead of
16451 Defaults to @samp{#f}.
16454 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
16455 Binary to use for sending mails.
16456 Defaults to @samp{"/usr/sbin/sendmail"}.
16459 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
16460 If non-empty, send mails via this SMTP host[:port] instead of
16462 Defaults to @samp{""}.
16465 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
16466 Subject: header to use for rejection mails. You can use the same
16467 variables as for @samp{rejection-reason} below.
16468 Defaults to @samp{"Rejected: %s"}.
16471 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
16472 Human readable error message for rejection mails. You can use
16485 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
16488 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
16489 Delimiter character between local-part and detail in email
16491 Defaults to @samp{"+"}.
16494 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
16495 Header where the original recipient address (SMTP's RCPT TO:
16496 address) is taken from if not available elsewhere. With dovecot-lda -a
16497 parameter overrides this. A commonly used header for this is
16499 Defaults to @samp{""}.
16502 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
16503 Should saving a mail to a nonexistent mailbox automatically create
16505 Defaults to @samp{#f}.
16508 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
16509 Should automatically created mailboxes be also automatically
16511 Defaults to @samp{#f}.
16514 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
16515 Maximum IMAP command line length. Some clients generate very long
16516 command lines with huge mailboxes, so you may need to raise this if you
16517 get "Too long argument" or "IMAP command line too large" errors
16519 Defaults to @samp{64000}.
16522 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
16523 IMAP logout format string:
16526 total number of bytes read from client
16528 total number of bytes sent to client.
16530 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
16531 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@}"}.
16534 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
16535 Override the IMAP CAPABILITY response. If the value begins with '+',
16536 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
16537 Defaults to @samp{""}.
16540 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
16541 How long to wait between "OK Still here" notifications when client
16543 Defaults to @samp{"2 mins"}.
16546 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
16547 ID field names and values to send to clients. Using * as the value
16548 makes Dovecot use the default value. The following fields have default
16549 values currently: name, version, os, os-version, support-url,
16551 Defaults to @samp{""}.
16554 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
16555 ID fields sent by client to log. * means everything.
16556 Defaults to @samp{""}.
16559 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
16560 Workarounds for various client bugs:
16563 @item delay-newmail
16564 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
16565 CHECK commands. Some clients ignore them otherwise, for example OSX
16566 Mail (<v2.1). Outlook Express breaks more badly though, without this it
16567 may show user "Message no longer in server" errors. Note that OE6
16568 still breaks even with this workaround if synchronization is set to
16571 @item tb-extra-mailbox-sep
16572 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
16573 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
16574 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
16576 @item tb-lsub-flags
16577 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
16578 This makes Thunderbird realize they aren't selectable and show them
16579 greyed out, instead of only later giving "not selectable" popup error.
16581 Defaults to @samp{()}.
16584 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
16585 Host allowed in URLAUTH URLs sent by client. "*" allows all.
16586 Defaults to @samp{""}.
16590 Whew! Lots of configuration options. The nice thing about it though is
16591 that Guix has a complete interface to Dovecot's configuration
16592 language. This allows not only a nice way to declare configurations,
16593 but also offers reflective capabilities as well: users can write code to
16594 inspect and transform configurations from within Scheme.
16596 However, it could be that you just want to get a @code{dovecot.conf} up
16597 and running. In that case, you can pass an
16598 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
16599 @code{dovecot-service}. As its name indicates, an opaque configuration
16600 does not have easy reflective capabilities.
16602 Available @code{opaque-dovecot-configuration} fields are:
16604 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
16605 The dovecot package.
16608 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
16609 The contents of the @code{dovecot.conf}, as a string.
16612 For example, if your @code{dovecot.conf} is just the empty string, you
16613 could instantiate a dovecot service like this:
16616 (dovecot-service #:config
16617 (opaque-dovecot-configuration
16621 @subsubheading OpenSMTPD Service
16623 @deffn {Scheme Variable} opensmtpd-service-type
16624 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
16625 service, whose value should be an @code{opensmtpd-configuration} object
16626 as in this example:
16629 (service opensmtpd-service-type
16630 (opensmtpd-configuration
16631 (config-file (local-file "./my-smtpd.conf"))))
16635 @deftp {Data Type} opensmtpd-configuration
16636 Data type representing the configuration of opensmtpd.
16639 @item @code{package} (default: @var{opensmtpd})
16640 Package object of the OpenSMTPD SMTP server.
16642 @item @code{config-file} (default: @var{%default-opensmtpd-file})
16643 File-like object of the OpenSMTPD configuration file to use. By default
16644 it listens on the loopback network interface, and allows for mail from
16645 users and daemons on the local machine, as well as permitting email to
16646 remote servers. Run @command{man smtpd.conf} for more information.
16651 @subsubheading Exim Service
16653 @cindex mail transfer agent (MTA)
16654 @cindex MTA (mail transfer agent)
16657 @deffn {Scheme Variable} exim-service-type
16658 This is the type of the @uref{https://exim.org, Exim} mail transfer
16659 agent (MTA), whose value should be an @code{exim-configuration} object
16660 as in this example:
16663 (service exim-service-type
16664 (exim-configuration
16665 (config-file (local-file "./my-exim.conf"))))
16669 In order to use an @code{exim-service-type} service you must also have a
16670 @code{mail-aliases-service-type} service present in your
16671 @code{operating-system} (even if it has no aliases).
16673 @deftp {Data Type} exim-configuration
16674 Data type representing the configuration of exim.
16677 @item @code{package} (default: @var{exim})
16678 Package object of the Exim server.
16680 @item @code{config-file} (default: @code{#f})
16681 File-like object of the Exim configuration file to use. If its value is
16682 @code{#f} then use the default configuration file from the package
16683 provided in @code{package}. The resulting configuration file is loaded
16684 after setting the @code{exim_user} and @code{exim_group} configuration
16690 @subsubheading Mail Aliases Service
16692 @cindex email aliases
16693 @cindex aliases, for email addresses
16695 @deffn {Scheme Variable} mail-aliases-service-type
16696 This is the type of the service which provides @code{/etc/aliases},
16697 specifying how to deliver mail to users on this system.
16700 (service mail-aliases-service-type
16701 '(("postmaster" "bob")
16702 ("bob" "bob@@example.com" "bob@@example2.com")))
16706 The configuration for a @code{mail-aliases-service-type} service is an
16707 association list denoting how to deliver mail that comes to this
16708 system. Each entry is of the form @code{(alias addresses ...)}, with
16709 @code{alias} specifying the local alias and @code{addresses} specifying
16710 where to deliver this user's mail.
16712 The aliases aren't required to exist as users on the local system. In
16713 the above example, there doesn't need to be a @code{postmaster} entry in
16714 the @code{operating-system}'s @code{user-accounts} in order to deliver
16715 the @code{postmaster} mail to @code{bob} (which subsequently would
16716 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
16718 @subsubheading GNU Mailutils IMAP4 Daemon
16719 @cindex GNU Mailutils IMAP4 Daemon
16721 @deffn {Scheme Variable} imap4d-service-type
16722 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
16723 mailutils, GNU Mailutils Manual}), whose value should be an
16724 @code{imap4d-configuration} object as in this example:
16727 (service imap4d-service-type
16728 (imap4d-configuration
16729 (config-file (local-file "imap4d.conf"))))
16733 @deftp {Data Type} imap4d-configuration
16734 Data type representing the configuration of @command{imap4d}.
16737 @item @code{package} (default: @code{mailutils})
16738 The package that provides @command{imap4d}.
16740 @item @code{config-file} (default: @code{%default-imap4d-config-file})
16741 File-like object of the configuration file to use, by default it will listen
16742 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
16743 Mailutils Manual}, for details.
16748 @node Messaging Services
16749 @subsection Messaging Services
16754 The @code{(gnu services messaging)} module provides Guix service
16755 definitions for messaging services: currently only Prosody is supported.
16757 @subsubheading Prosody Service
16759 @deffn {Scheme Variable} prosody-service-type
16760 This is the type for the @uref{https://prosody.im, Prosody XMPP
16761 communication server}. Its value must be a @code{prosody-configuration}
16762 record as in this example:
16765 (service prosody-service-type
16766 (prosody-configuration
16767 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
16770 (int-component-configuration
16771 (hostname "conference.example.net")
16773 (mod-muc (mod-muc-configuration)))))
16776 (virtualhost-configuration
16777 (domain "example.net"))))))
16780 See below for details about @code{prosody-configuration}.
16784 By default, Prosody does not need much configuration. Only one
16785 @code{virtualhosts} field is needed: it specifies the domain you wish
16788 You can perform various sanity checks on the generated configuration
16789 with the @code{prosodyctl check} command.
16791 Prosodyctl will also help you to import certificates from the
16792 @code{letsencrypt} directory so that the @code{prosody} user can access
16793 them. See @url{https://prosody.im/doc/letsencrypt}.
16796 prosodyctl --root cert import /etc/letsencrypt/live
16799 The available configuration parameters follow. Each parameter
16800 definition is preceded by its type; for example, @samp{string-list foo}
16801 indicates that the @code{foo} parameter should be specified as a list of
16802 strings. Types starting with @code{maybe-} denote parameters that won't
16803 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
16805 There is also a way to specify the configuration as a string, if you
16806 have an old @code{prosody.cfg.lua} file that you want to port over from
16807 some other system; see the end for more details.
16809 The @code{file-object} type designates either a file-like object
16810 (@pxref{G-Expressions, file-like objects}) or a file name.
16812 @c The following documentation was initially generated by
16813 @c (generate-documentation) in (gnu services messaging). Manually maintained
16814 @c documentation is better, so we shouldn't hesitate to edit below as
16815 @c needed. However if the change you want to make to this documentation
16816 @c can be done in an automated way, it's probably easier to change
16817 @c (generate-documentation) than to make it below and have to deal with
16818 @c the churn as Prosody updates.
16820 Available @code{prosody-configuration} fields are:
16822 @deftypevr {@code{prosody-configuration} parameter} package prosody
16823 The Prosody package.
16826 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
16827 Location of the Prosody data storage directory. See
16828 @url{https://prosody.im/doc/configure}.
16829 Defaults to @samp{"/var/lib/prosody"}.
16832 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
16833 Additional plugin directories. They are searched in all the specified
16834 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
16835 Defaults to @samp{()}.
16838 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
16839 Every virtual host and component needs a certificate so that clients and
16840 servers can securely verify its identity. Prosody will automatically load
16841 certificates/keys from the directory specified here.
16842 Defaults to @samp{"/etc/prosody/certs"}.
16845 @deftypevr {@code{prosody-configuration} parameter} string-list admins
16846 This is a list of accounts that are admins for the server. Note that you
16847 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
16848 @url{https://prosody.im/doc/creating_accounts}.
16849 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
16850 Defaults to @samp{()}.
16853 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
16854 Enable use of libevent for better performance under high load. See
16855 @url{https://prosody.im/doc/libevent}.
16856 Defaults to @samp{#f}.
16859 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
16860 This is the list of modules Prosody will load on startup. It looks for
16861 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
16862 Documentation on modules can be found at:
16863 @url{https://prosody.im/doc/modules}.
16864 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
16867 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
16868 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
16869 should you want to disable them then add them to this list.
16870 Defaults to @samp{()}.
16873 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
16874 Path to a text file where the shared groups are defined. If this path is
16875 empty then @samp{mod_groups} does nothing. See
16876 @url{https://prosody.im/doc/modules/mod_groups}.
16877 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
16880 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
16881 Disable account creation by default, for security. See
16882 @url{https://prosody.im/doc/creating_accounts}.
16883 Defaults to @samp{#f}.
16886 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
16887 These are the SSL/TLS-related settings. Most of them are disabled so to
16888 use Prosody's defaults. If you do not completely understand these options, do
16889 not add them to your config, it is easy to lower the security of your server
16890 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
16892 Available @code{ssl-configuration} fields are:
16894 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
16895 This determines what handshake to use.
16898 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
16899 Path to your private key file.
16902 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
16903 Path to your certificate file.
16906 @deftypevr {@code{ssl-configuration} parameter} file-object capath
16907 Path to directory containing root certificates that you wish Prosody to
16908 trust when verifying the certificates of remote servers.
16909 Defaults to @samp{"/etc/ssl/certs"}.
16912 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
16913 Path to a file containing root certificates that you wish Prosody to trust.
16914 Similar to @code{capath} but with all certificates concatenated together.
16917 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
16918 A list of verification options (these mostly map to OpenSSL's
16919 @code{set_verify()} flags).
16922 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
16923 A list of general options relating to SSL/TLS. These map to OpenSSL's
16924 @code{set_options()}. For a full list of options available in LuaSec, see the
16928 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
16929 How long a chain of certificate authorities to check when looking for a
16930 trusted root certificate.
16933 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
16934 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
16935 clients, and in what order.
16938 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
16939 A path to a file containing parameters for Diffie-Hellman key exchange. You
16940 can create such a file with:
16941 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
16944 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
16945 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
16946 @samp{"secp384r1"}.
16949 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
16950 A list of "extra" verification options.
16953 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
16954 Password for encrypted private keys.
16959 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
16960 Whether to force all client-to-server connections to be encrypted or not.
16961 See @url{https://prosody.im/doc/modules/mod_tls}.
16962 Defaults to @samp{#f}.
16965 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
16966 Set of mechanisms that will never be offered. See
16967 @url{https://prosody.im/doc/modules/mod_saslauth}.
16968 Defaults to @samp{("DIGEST-MD5")}.
16971 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
16972 Whether to force all server-to-server connections to be encrypted or not.
16973 See @url{https://prosody.im/doc/modules/mod_tls}.
16974 Defaults to @samp{#f}.
16977 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
16978 Whether to require encryption and certificate authentication. This
16979 provides ideal security, but requires servers you communicate with to support
16980 encryption AND present valid, trusted certificates. See
16981 @url{https://prosody.im/doc/s2s#security}.
16982 Defaults to @samp{#f}.
16985 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
16986 Many servers don't support encryption or have invalid or self-signed
16987 certificates. You can list domains here that will not be required to
16988 authenticate using certificates. They will be authenticated using DNS. See
16989 @url{https://prosody.im/doc/s2s#security}.
16990 Defaults to @samp{()}.
16993 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
16994 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
16995 valid certificates for some domains by specifying a list here. See
16996 @url{https://prosody.im/doc/s2s#security}.
16997 Defaults to @samp{()}.
17000 @deftypevr {@code{prosody-configuration} parameter} string authentication
17001 Select the authentication backend to use. The default provider stores
17002 passwords in plaintext and uses Prosody's configured data storage to store the
17003 authentication data. If you do not trust your server please see
17004 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
17005 about using the hashed backend. See also
17006 @url{https://prosody.im/doc/authentication}
17007 Defaults to @samp{"internal_plain"}.
17010 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
17011 Set logging options. Advanced logging configuration is not yet supported
17012 by the Prosody service. See @url{https://prosody.im/doc/logging}.
17013 Defaults to @samp{"*syslog"}.
17016 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
17017 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
17018 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
17021 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
17022 Maximum allowed size of the HTTP body (in bytes).
17025 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
17026 Some modules expose their own URL in various ways. This URL is built
17027 from the protocol, host and port used. If Prosody sits behind a proxy, the
17028 public URL will be @code{http-external-url} instead. See
17029 @url{https://prosody.im/doc/http#external_url}.
17032 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
17033 A host in Prosody is a domain on which user accounts can be created. For
17034 example if you want your users to have addresses like
17035 @samp{"john.smith@@example.com"} then you need to add a host
17036 @samp{"example.com"}. All options in this list will apply only to this host.
17038 Note: the name "virtual" host is used in configuration to avoid confusion with
17039 the actual physical host that Prosody is installed on. A single Prosody
17040 instance can serve many domains, each one defined as a VirtualHost entry in
17041 Prosody's configuration. Conversely a server that hosts a single domain would
17042 have just one VirtualHost entry.
17044 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
17046 Available @code{virtualhost-configuration} fields are:
17048 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:
17049 @deftypevr {@code{virtualhost-configuration} parameter} string domain
17050 Domain you wish Prosody to serve.
17055 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
17056 Components are extra services on a server which are available to clients,
17057 usually on a subdomain of the main server (such as
17058 @samp{"mycomponent.example.com"}). Example components might be chatroom
17059 servers, user directories, or gateways to other protocols.
17061 Internal components are implemented with Prosody-specific plugins. To add an
17062 internal component, you simply fill the hostname field, and the plugin you wish
17063 to use for the component.
17065 See @url{https://prosody.im/doc/components}.
17066 Defaults to @samp{()}.
17068 Available @code{int-component-configuration} fields are:
17070 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:
17071 @deftypevr {@code{int-component-configuration} parameter} string hostname
17072 Hostname of the component.
17075 @deftypevr {@code{int-component-configuration} parameter} string plugin
17076 Plugin you wish to use for the component.
17079 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
17080 Multi-user chat (MUC) is Prosody's module for allowing you to create
17081 hosted chatrooms/conferences for XMPP users.
17083 General information on setting up and using multi-user chatrooms can be found
17084 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
17085 which you should read if you are new to XMPP chatrooms.
17087 See also @url{https://prosody.im/doc/modules/mod_muc}.
17089 Available @code{mod-muc-configuration} fields are:
17091 @deftypevr {@code{mod-muc-configuration} parameter} string name
17092 The name to return in service discovery responses.
17093 Defaults to @samp{"Prosody Chatrooms"}.
17096 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
17097 If @samp{#t}, this will only allow admins to create new chatrooms.
17098 Otherwise anyone can create a room. The value @samp{"local"} restricts room
17099 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
17100 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
17101 restricts to service administrators only.
17102 Defaults to @samp{#f}.
17105 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
17106 Maximum number of history messages that will be sent to the member that has
17107 just joined the room.
17108 Defaults to @samp{20}.
17115 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
17116 External components use XEP-0114, which most standalone components
17117 support. To add an external component, you simply fill the hostname field. See
17118 @url{https://prosody.im/doc/components}.
17119 Defaults to @samp{()}.
17121 Available @code{ext-component-configuration} fields are:
17123 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:
17124 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
17125 Password which the component will use to log in.
17128 @deftypevr {@code{ext-component-configuration} parameter} string hostname
17129 Hostname of the component.
17134 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
17135 Port(s) Prosody listens on for component connections.
17136 Defaults to @samp{(5347)}.
17139 @deftypevr {@code{prosody-configuration} parameter} string component-interface
17140 Interface Prosody listens on for component connections.
17141 Defaults to @samp{"127.0.0.1"}.
17144 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
17145 Raw content that will be added to the configuration file.
17148 It could be that you just want to get a @code{prosody.cfg.lua}
17149 up and running. In that case, you can pass an
17150 @code{opaque-prosody-configuration} record as the value of
17151 @code{prosody-service-type}. As its name indicates, an opaque configuration
17152 does not have easy reflective capabilities.
17153 Available @code{opaque-prosody-configuration} fields are:
17155 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
17156 The prosody package.
17159 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
17160 The contents of the @code{prosody.cfg.lua} to use.
17163 For example, if your @code{prosody.cfg.lua} is just the empty
17164 string, you could instantiate a prosody service like this:
17167 (service prosody-service-type
17168 (opaque-prosody-configuration
17169 (prosody.cfg.lua "")))
17172 @c end of Prosody auto-generated documentation
17174 @subsubheading BitlBee Service
17176 @cindex IRC (Internet Relay Chat)
17177 @cindex IRC gateway
17178 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
17179 interface to a variety of messaging protocols such as XMPP.
17181 @defvr {Scheme Variable} bitlbee-service-type
17182 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
17183 gateway daemon. Its value is a @code{bitlbee-configuration} (see
17186 To have BitlBee listen on port 6667 on localhost, add this line to your
17190 (service bitlbee-service-type)
17194 @deftp {Data Type} bitlbee-configuration
17195 This is the configuration for BitlBee, with the following fields:
17198 @item @code{interface} (default: @code{"127.0.0.1"})
17199 @itemx @code{port} (default: @code{6667})
17200 Listen on the network interface corresponding to the IP address
17201 specified in @var{interface}, on @var{port}.
17203 When @var{interface} is @code{127.0.0.1}, only local clients can
17204 connect; when it is @code{0.0.0.0}, connections can come from any
17205 networking interface.
17207 @item @code{package} (default: @code{bitlbee})
17208 The BitlBee package to use.
17210 @item @code{plugins} (default: @code{'()})
17211 List of plugin packages to use---e.g., @code{bitlbee-discord}.
17213 @item @code{extra-settings} (default: @code{""})
17214 Configuration snippet added as-is to the BitlBee configuration file.
17218 @subsubheading Quassel Service
17220 @cindex IRC (Internet Relay Chat)
17221 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
17222 meaning that one or more clients can attach to and detach from the
17225 @defvr {Scheme Variable} quassel-service-type
17226 This is the service type for the @url{https://quassel-irc.org/,Quassel}
17227 IRC backend daemon. Its value is a @code{quassel-configuration}
17231 @deftp {Data Type} quassel-configuration
17232 This is the configuration for Quassel, with the following fields:
17235 @item @code{quassel} (default: @code{quassel})
17236 The Quassel package to use.
17238 @item @code{interface} (default: @code{"::,0.0.0.0"})
17239 @item @code{port} (default: @code{4242})
17240 Listen on the network interface(s) corresponding to the IPv4 or IPv6
17241 interfaces specified in the comma delimited @var{interface}, on
17244 @item @code{loglevel} (default: @code{"Info"})
17245 The level of logging desired. Accepted values are Debug, Info, Warning
17250 @node Telephony Services
17251 @subsection Telephony Services
17253 @cindex Murmur (VoIP server)
17254 @cindex VoIP server
17255 This section describes how to set up and run a Murmur server. Murmur is
17256 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
17259 @deftp {Data Type} murmur-configuration
17260 The service type for the Murmur server. An example configuration can
17264 (service murmur-service-type
17265 (murmur-configuration
17267 "Welcome to this Mumble server running on Guix!")
17268 (cert-required? #t) ;disallow text password logins
17269 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
17270 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
17273 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
17274 password with the command that is printed during the activation phase.
17276 It is recommended to register a normal Mumble user account
17277 and grant it admin or moderator rights.
17278 You can use the @code{mumble} client to
17279 login as new normal user, register yourself, and log out.
17280 For the next step login with the name @code{SuperUser} use
17281 the @code{SuperUser} password that you set previously,
17282 and grant your newly registered mumble user administrator or moderator
17283 rights and create some channels.
17285 Available @code{murmur-configuration} fields are:
17288 @item @code{package} (default: @code{mumble})
17289 Package that contains @code{bin/murmurd}.
17291 @item @code{user} (default: @code{"murmur"})
17292 User who will run the Murmur server.
17294 @item @code{group} (default: @code{"murmur"})
17295 Group of the user who will run the murmur server.
17297 @item @code{port} (default: @code{64738})
17298 Port on which the server will listen.
17300 @item @code{welcome-text} (default: @code{""})
17301 Welcome text sent to clients when they connect.
17303 @item @code{server-password} (default: @code{""})
17304 Password the clients have to enter in order to connect.
17306 @item @code{max-users} (default: @code{100})
17307 Maximum of users that can be connected to the server at once.
17309 @item @code{max-user-bandwidth} (default: @code{#f})
17310 Maximum voice traffic a user can send per second.
17312 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
17313 File name of the sqlite database.
17314 The service's user will become the owner of the directory.
17316 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
17317 File name of the log file.
17318 The service's user will become the owner of the directory.
17320 @item @code{autoban-attempts} (default: @code{10})
17321 Maximum number of logins a user can make in @code{autoban-timeframe}
17322 without getting auto banned for @code{autoban-time}.
17324 @item @code{autoban-timeframe} (default: @code{120})
17325 Timeframe for autoban in seconds.
17327 @item @code{autoban-time} (default: @code{300})
17328 Amount of time in seconds for which a client gets banned
17329 when violating the autoban limits.
17331 @item @code{opus-threshold} (default: @code{100})
17332 Percentage of clients that need to support opus
17333 before switching over to opus audio codec.
17335 @item @code{channel-nesting-limit} (default: @code{10})
17336 How deep channels can be nested at maximum.
17338 @item @code{channelname-regex} (default: @code{#f})
17339 A string in form of a Qt regular expression that channel names must conform to.
17341 @item @code{username-regex} (default: @code{#f})
17342 A string in form of a Qt regular expression that user names must conform to.
17344 @item @code{text-message-length} (default: @code{5000})
17345 Maximum size in bytes that a user can send in one text chat message.
17347 @item @code{image-message-length} (default: @code{(* 128 1024)})
17348 Maximum size in bytes that a user can send in one image message.
17350 @item @code{cert-required?} (default: @code{#f})
17351 If it is set to @code{#t} clients that use weak password authentification
17352 will not be accepted. Users must have completed the certificate wizard to join.
17354 @item @code{remember-channel?} (default: @code{#f})
17355 Should murmur remember the last channel each user was in when they disconnected
17356 and put them into the remembered channel when they rejoin.
17358 @item @code{allow-html?} (default: @code{#f})
17359 Should html be allowed in text messages, user comments, and channel descriptions.
17361 @item @code{allow-ping?} (default: @code{#f})
17362 Setting to true exposes the current user count, the maximum user count, and
17363 the server's maximum bandwidth per client to unauthenticated users. In the
17364 Mumble client, this information is shown in the Connect dialog.
17366 Disabling this setting will prevent public listing of the server.
17368 @item @code{bonjour?} (default: @code{#f})
17369 Should the server advertise itself in the local network through the bonjour protocol.
17371 @item @code{send-version?} (default: @code{#f})
17372 Should the murmur server version be exposed in ping requests.
17374 @item @code{log-days} (default: @code{31})
17375 Murmur also stores logs in the database, which are accessible via RPC.
17376 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
17377 or -1 to disable logging to the database.
17379 @item @code{obfuscate-ips?} (default: @code{#t})
17380 Should logged ips be obfuscated to protect the privacy of users.
17382 @item @code{ssl-cert} (default: @code{#f})
17383 File name of the SSL/TLS certificate used for encrypted connections.
17386 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
17388 @item @code{ssl-key} (default: @code{#f})
17389 Filepath to the ssl private key used for encrypted connections.
17391 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
17394 @item @code{ssl-dh-params} (default: @code{#f})
17395 File name of a PEM-encoded file with Diffie-Hellman parameters
17396 for the SSL/TLS encryption. Alternatively you set it to
17397 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
17398 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
17400 @item @code{ssl-ciphers} (default: @code{#f})
17401 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
17404 This option is specified using
17405 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
17406 OpenSSL cipher list notation}.
17408 It is recommended that you try your cipher string using 'openssl ciphers <string>'
17409 before setting it here, to get a feel for which cipher suites you will get.
17410 After setting this option, it is recommend that you inspect your Murmur log
17411 to ensure that Murmur is using the cipher suites that you expected it to.
17413 Note: Changing this option may impact the backwards compatibility of your
17414 Murmur server, and can remove the ability for older Mumble clients to be able
17417 @item @code{public-registration} (default: @code{#f})
17418 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
17420 You can optionally register your server in the public server list that the
17421 @code{mumble} client shows on startup.
17422 You cannot register your server if you have set a @code{server-password},
17423 or set @code{allow-ping} to @code{#f}.
17425 It might take a few hours until it shows up in the public list.
17427 @item @code{file} (default: @code{#f})
17428 Optional alternative override for this configuration.
17432 @deftp {Data Type} murmur-public-registration-configuration
17433 Configuration for public registration of a murmur service.
17437 This is a display name for your server. Not to be confused with the hostname.
17439 @item @code{password}
17440 A password to identify your registration.
17441 Subsequent updates will need the same password. Don't lose your password.
17444 This should be a @code{http://} or @code{https://} link to your web
17447 @item @code{hostname} (default: @code{#f})
17448 By default your server will be listed by its IP address.
17449 If it is set your server will be linked by this host name instead.
17455 @node Monitoring Services
17456 @subsection Monitoring Services
17458 @subsubheading Tailon Service
17460 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
17461 viewing and searching log files.
17463 The following example will configure the service with default values.
17464 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
17467 (service tailon-service-type)
17470 The following example customises more of the Tailon configuration,
17471 adding @command{sed} to the list of allowed commands.
17474 (service tailon-service-type
17475 (tailon-configuration
17477 (tailon-configuration-file
17478 (allowed-commands '("tail" "grep" "awk" "sed"))))))
17482 @deftp {Data Type} tailon-configuration
17483 Data type representing the configuration of Tailon.
17484 This type has the following parameters:
17487 @item @code{config-file} (default: @code{(tailon-configuration-file)})
17488 The configuration file to use for Tailon. This can be set to a
17489 @dfn{tailon-configuration-file} record value, or any gexp
17490 (@pxref{G-Expressions}).
17492 For example, to instead use a local file, the @code{local-file} function
17496 (service tailon-service-type
17497 (tailon-configuration
17498 (config-file (local-file "./my-tailon.conf"))))
17501 @item @code{package} (default: @code{tailon})
17502 The tailon package to use.
17507 @deftp {Data Type} tailon-configuration-file
17508 Data type representing the configuration options for Tailon.
17509 This type has the following parameters:
17512 @item @code{files} (default: @code{(list "/var/log")})
17513 List of files to display. The list can include strings for a single file
17514 or directory, or a list, where the first item is the name of a
17515 subsection, and the remaining items are the files or directories in that
17518 @item @code{bind} (default: @code{"localhost:8080"})
17519 Address and port to which Tailon should bind on.
17521 @item @code{relative-root} (default: @code{#f})
17522 URL path to use for Tailon, set to @code{#f} to not use a path.
17524 @item @code{allow-transfers?} (default: @code{#t})
17525 Allow downloading the log files in the web interface.
17527 @item @code{follow-names?} (default: @code{#t})
17528 Allow tailing of not-yet existent files.
17530 @item @code{tail-lines} (default: @code{200})
17531 Number of lines to read initially from each file.
17533 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
17534 Commands to allow running. By default, @code{sed} is disabled.
17536 @item @code{debug?} (default: @code{#f})
17537 Set @code{debug?} to @code{#t} to show debug messages.
17539 @item @code{wrap-lines} (default: @code{#t})
17540 Initial line wrapping state in the web interface. Set to @code{#t} to
17541 initially wrap lines (the default), or to @code{#f} to initially not
17544 @item @code{http-auth} (default: @code{#f})
17545 HTTP authentication type to use. Set to @code{#f} to disable
17546 authentication (the default). Supported values are @code{"digest"} or
17549 @item @code{users} (default: @code{#f})
17550 If HTTP authentication is enabled (see @code{http-auth}), access will be
17551 restricted to the credentials provided here. To configure users, use a
17552 list of pairs, where the first element of the pair is the username, and
17553 the 2nd element of the pair is the password.
17556 (tailon-configuration-file
17557 (http-auth "basic")
17558 (users '(("user1" . "password1")
17559 ("user2" . "password2"))))
17566 @subsubheading Darkstat Service
17568 Darkstat is a packet sniffer that captures network traffic, calculates
17569 statistics about usage, and serves reports over HTTP.
17571 @defvar {Scheme Variable} darkstat-service-type
17572 This is the service type for the
17573 @uref{https://unix4lyfe.org/darkstat/, darkstat}
17574 service, its value must be a @code{darkstat-configuration} record as in
17578 (service darkstat-service-type
17579 (darkstat-configuration
17580 (interface "eno1")))
17584 @deftp {Data Type} darkstat-configuration
17585 Data type representing the configuration of @command{darkstat}.
17588 @item @code{package} (default: @code{darkstat})
17589 The darkstat package to use.
17591 @item @code{interface}
17592 Capture traffic on the specified network interface.
17594 @item @code{port} (default: @code{"667"})
17595 Bind the web interface to the specified port.
17597 @item @code{bind-address} (default: @code{"127.0.0.1"})
17598 Bind the web interface to the specified address.
17600 @item @code{base} (default: @code{"/"})
17601 Specify the path of the base URL. This can be useful if
17602 @command{darkstat} is accessed via a reverse proxy.
17607 @subsubheading Prometheus Node Exporter Service
17609 @cindex prometheus-node-exporter
17610 The Prometheus ``node exporter'' makes hardware and operating system statistics
17611 provided by the Linux kernel available for the Prometheus monitoring system.
17612 This service should be deployed on all physical nodes and virtual machines,
17613 where monitoring these statistics is desirable.
17615 @defvar {Scheme variable} prometheus-node-exporter-service-type
17616 This is the service type for the
17617 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
17618 service, its value must be a @code{prometheus-node-exporter-configuration}
17619 record as in this example:
17622 (service prometheus-node-exporter-service-type
17623 (prometheus-node-exporter-configuration
17624 (web-listen-address ":9100")))
17628 @deftp {Data Type} prometheus-node-exporter-configuration
17629 Data type representing the configuration of @command{node_exporter}.
17632 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
17633 The prometheus-node-exporter package to use.
17635 @item @code{web-listen-address} (default: @code{":9100"})
17636 Bind the web interface to the specified address.
17641 @subsubheading Zabbix server
17642 @cindex zabbix zabbix-server
17643 Zabbix provides monitoring metrics, among others network utilization, CPU load
17644 and disk space consumption:
17647 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
17648 @item Auto-discovery of servers and network devices and interfaces.
17649 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
17650 @item Distributed monitoring with centralized web administration.
17651 @item Native high performance agents.
17652 @item SLA, and ITIL KPI metrics on reporting.
17653 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
17654 @item Remote command execution through Zabbix proxies.
17657 @c %start of fragment
17659 Available @code{zabbix-server-configuration} fields are:
17661 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
17662 The zabbix-server package.
17666 @deftypevr {@code{zabbix-server-configuration} parameter} string user
17667 User who will run the Zabbix server.
17669 Defaults to @samp{"zabbix"}.
17673 @deftypevr {@code{zabbix-server-configuration} parameter} group group
17674 Group who will run the Zabbix server.
17676 Defaults to @samp{"zabbix"}.
17680 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
17681 Database host name.
17683 Defaults to @samp{"127.0.0.1"}.
17687 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
17690 Defaults to @samp{"zabbix"}.
17694 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
17697 Defaults to @samp{"zabbix"}.
17701 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
17702 Database password. Please, use @code{include-files} with
17703 @code{DBPassword=SECRET} inside a specified file instead.
17705 Defaults to @samp{""}.
17709 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
17712 Defaults to @samp{5432}.
17716 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
17717 Specifies where log messages are written to:
17721 @code{system} - syslog.
17724 @code{file} - file specified with @code{log-file} parameter.
17727 @code{console} - standard output.
17731 Defaults to @samp{""}.
17735 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
17736 Log file name for @code{log-type} @code{file} parameter.
17738 Defaults to @samp{"/var/log/zabbix/server.log"}.
17742 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
17745 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
17749 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
17750 The location of certificate authority (CA) files for SSL server
17751 certificate verification.
17753 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
17757 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
17758 Location of SSL client certificates.
17760 Defaults to @samp{"/etc/ssl/certs"}.
17764 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
17765 Extra options will be appended to Zabbix server configuration file.
17767 Defaults to @samp{""}.
17771 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
17772 You may include individual files or all files in a directory in the
17773 configuration file.
17775 Defaults to @samp{()}.
17779 @c %end of fragment
17781 @subsubheading Zabbix agent
17782 @cindex zabbix zabbix-agent
17784 Zabbix agent gathers information for Zabbix server.
17786 @c %start of fragment
17788 Available @code{zabbix-agent-configuration} fields are:
17790 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
17791 The zabbix-agent package.
17795 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
17796 User who will run the Zabbix agent.
17798 Defaults to @samp{"zabbix"}.
17802 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
17803 Group who will run the Zabbix agent.
17805 Defaults to @samp{"zabbix"}.
17809 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
17810 Unique, case sensitive hostname which is required for active checks and
17811 must match hostname as configured on the server.
17813 Defaults to @samp{"Zabbix server"}.
17817 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
17818 Specifies where log messages are written to:
17822 @code{system} - syslog.
17825 @code{file} - file specified with @code{log-file} parameter.
17828 @code{console} - standard output.
17832 Defaults to @samp{""}.
17836 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
17837 Log file name for @code{log-type} @code{file} parameter.
17839 Defaults to @samp{"/var/log/zabbix/agent.log"}.
17843 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
17846 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
17850 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
17851 List of IP addresses, optionally in CIDR notation, or hostnames of
17852 Zabbix servers and Zabbix proxies. Incoming connections will be
17853 accepted only from the hosts listed here.
17855 Defaults to @samp{("127.0.0.1")}.
17859 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
17860 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
17861 proxies for active checks. If port is not specified, default port is
17862 used. If this parameter is not specified, active checks are disabled.
17864 Defaults to @samp{("127.0.0.1")}.
17868 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
17869 Extra options will be appended to Zabbix server configuration file.
17871 Defaults to @samp{""}.
17875 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
17876 You may include individual files or all files in a directory in the
17877 configuration file.
17879 Defaults to @samp{()}.
17883 @c %end of fragment
17885 @subsubheading Zabbix front-end
17886 @cindex zabbix zabbix-front-end
17888 This service provides a WEB interface to Zabbix server.
17890 @c %start of fragment
17892 Available @code{zabbix-front-end-configuration} fields are:
17894 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
17895 NGINX configuration.
17899 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
17900 Database host name.
17902 Defaults to @samp{"localhost"}.
17906 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
17909 Defaults to @samp{5432}.
17913 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
17916 Defaults to @samp{"zabbix"}.
17920 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
17923 Defaults to @samp{"zabbix"}.
17927 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
17928 Database password. Please, use @code{db-secret-file} instead.
17930 Defaults to @samp{""}.
17934 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
17935 Secret file which will be appended to @file{zabbix.conf.php} file. This
17936 file contains credentials for use by Zabbix front-end. You are expected
17937 to create it manually.
17939 Defaults to @samp{""}.
17943 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
17944 Zabbix server hostname.
17946 Defaults to @samp{"localhost"}.
17950 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
17951 Zabbix server port.
17953 Defaults to @samp{10051}.
17958 @c %end of fragment
17960 @node Kerberos Services
17961 @subsection Kerberos Services
17964 The @code{(gnu services kerberos)} module provides services relating to
17965 the authentication protocol @dfn{Kerberos}.
17967 @subsubheading Krb5 Service
17969 Programs using a Kerberos client library normally
17970 expect a configuration file in @file{/etc/krb5.conf}.
17971 This service generates such a file from a definition provided in the
17972 operating system declaration.
17973 It does not cause any daemon to be started.
17975 No ``keytab'' files are provided by this service---you must explicitly create them.
17976 This service is known to work with the MIT client library, @code{mit-krb5}.
17977 Other implementations have not been tested.
17979 @defvr {Scheme Variable} krb5-service-type
17980 A service type for Kerberos 5 clients.
17984 Here is an example of its use:
17986 (service krb5-service-type
17987 (krb5-configuration
17988 (default-realm "EXAMPLE.COM")
17989 (allow-weak-crypto? #t)
17992 (name "EXAMPLE.COM")
17993 (admin-server "groucho.example.com")
17994 (kdc "karl.example.com"))
17997 (admin-server "kerb-admin.argrx.edu")
17998 (kdc "keys.argrx.edu"))))))
18002 This example provides a Kerberos@tie{}5 client configuration which:
18004 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
18005 of which have distinct administration servers and key distribution centers;
18006 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
18007 specified by clients;
18008 @item Accepts services which only support encryption types known to be weak.
18011 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
18012 Only the most commonly used ones are described here.
18013 For a full list, and more detailed explanation of each, see the MIT
18014 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
18018 @deftp {Data Type} krb5-realm
18019 @cindex realm, kerberos
18022 This field is a string identifying the name of the realm.
18023 A common convention is to use the fully qualified DNS name of your organization,
18024 converted to upper case.
18026 @item @code{admin-server}
18027 This field is a string identifying the host where the administration server is
18031 This field is a string identifying the key distribution center
18036 @deftp {Data Type} krb5-configuration
18039 @item @code{allow-weak-crypto?} (default: @code{#f})
18040 If this flag is @code{#t} then services which only offer encryption algorithms
18041 known to be weak will be accepted.
18043 @item @code{default-realm} (default: @code{#f})
18044 This field should be a string identifying the default Kerberos
18045 realm for the client.
18046 You should set this field to the name of your Kerberos realm.
18047 If this value is @code{#f}
18048 then a realm must be specified with every Kerberos principal when invoking programs
18049 such as @command{kinit}.
18051 @item @code{realms}
18052 This should be a non-empty list of @code{krb5-realm} objects, which clients may
18054 Normally, one of them will have a @code{name} field matching the @code{default-realm}
18060 @subsubheading PAM krb5 Service
18063 The @code{pam-krb5} service allows for login authentication and password
18064 management via Kerberos.
18065 You will need this service if you want PAM enabled applications to authenticate
18066 users using Kerberos.
18068 @defvr {Scheme Variable} pam-krb5-service-type
18069 A service type for the Kerberos 5 PAM module.
18072 @deftp {Data Type} pam-krb5-configuration
18073 Data type representing the configuration of the Kerberos 5 PAM module.
18074 This type has the following parameters:
18076 @item @code{pam-krb5} (default: @code{pam-krb5})
18077 The pam-krb5 package to use.
18079 @item @code{minimum-uid} (default: @code{1000})
18080 The smallest user ID for which Kerberos authentications should be attempted.
18081 Local accounts with lower values will silently fail to authenticate.
18086 @node LDAP Services
18087 @subsection LDAP Services
18089 @cindex nslcd, LDAP service
18091 The @code{(gnu services authentication)} module provides the
18092 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
18093 server. In addition to configuring the service itself, you may want to add
18094 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
18095 Switch} for detailed information.
18097 Here is a simple operating system declaration with a default configuration of
18098 the @code{nslcd-service-type} and a Name Service Switch configuration that
18099 consults the @code{ldap} name service last:
18102 (use-service-modules authentication)
18103 (use-modules (gnu system nss))
18109 (service nslcd-service-type)
18110 (service dhcp-client-service-type)
18112 (name-service-switch
18113 (let ((services (list (name-service (name "db"))
18114 (name-service (name "files"))
18115 (name-service (name "ldap")))))
18116 (name-service-switch
18117 (inherit %mdns-host-lookup-nss)
18118 (password services)
18121 (netgroup services)
18122 (gshadow services)))))
18125 @c %start of generated documentation for nslcd-configuration
18127 Available @code{nslcd-configuration} fields are:
18129 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
18130 The @code{nss-pam-ldapd} package to use.
18134 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
18135 The number of threads to start that can handle requests and perform LDAP
18136 queries. Each thread opens a separate connection to the LDAP server.
18137 The default is to start 5 threads.
18139 Defaults to @samp{disabled}.
18143 @deftypevr {@code{nslcd-configuration} parameter} string uid
18144 This specifies the user id with which the daemon should be run.
18146 Defaults to @samp{"nslcd"}.
18150 @deftypevr {@code{nslcd-configuration} parameter} string gid
18151 This specifies the group id with which the daemon should be run.
18153 Defaults to @samp{"nslcd"}.
18157 @deftypevr {@code{nslcd-configuration} parameter} log-option log
18158 This option controls the way logging is done via a list containing
18159 SCHEME and LEVEL. The SCHEME argument may either be the symbols "none"
18160 or "syslog", or an absolute file name. The LEVEL argument is optional
18161 and specifies the log level. The log level may be one of the following
18162 symbols: "crit", "error", "warning", "notice", "info" or "debug". All
18163 messages with the specified log level or higher are logged.
18165 Defaults to @samp{("/var/log/nslcd" info)}.
18169 @deftypevr {@code{nslcd-configuration} parameter} list uri
18170 The list of LDAP server URIs. Normally, only the first server will be
18171 used with the following servers as fall-back.
18173 Defaults to @samp{("ldap://localhost:389/")}.
18177 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
18178 The version of the LDAP protocol to use. The default is to use the
18179 maximum version supported by the LDAP library.
18181 Defaults to @samp{disabled}.
18185 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
18186 Specifies the distinguished name with which to bind to the directory
18187 server for lookups. The default is to bind anonymously.
18189 Defaults to @samp{disabled}.
18193 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
18194 Specifies the credentials with which to bind. This option is only
18195 applicable when used with binddn.
18197 Defaults to @samp{disabled}.
18201 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
18202 Specifies the distinguished name to use when the root user tries to
18203 modify a user's password using the PAM module.
18205 Defaults to @samp{disabled}.
18209 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
18210 Specifies the credentials with which to bind if the root user tries to
18211 change a user's password. This option is only applicable when used with
18214 Defaults to @samp{disabled}.
18218 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
18219 Specifies the SASL mechanism to be used when performing SASL
18222 Defaults to @samp{disabled}.
18226 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
18227 Specifies the SASL realm to be used when performing SASL authentication.
18229 Defaults to @samp{disabled}.
18233 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
18234 Specifies the authentication identity to be used when performing SASL
18237 Defaults to @samp{disabled}.
18241 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
18242 Specifies the authorization identity to be used when performing SASL
18245 Defaults to @samp{disabled}.
18249 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
18250 Determines whether the LDAP server host name should be canonicalised. If
18251 this is enabled the LDAP library will do a reverse host name lookup. By
18252 default, it is left up to the LDAP library whether this check is
18255 Defaults to @samp{disabled}.
18259 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
18260 Set the name for the GSS-API Kerberos credentials cache.
18262 Defaults to @samp{disabled}.
18266 @deftypevr {@code{nslcd-configuration} parameter} string base
18267 The directory search base.
18269 Defaults to @samp{"dc=example,dc=com"}.
18273 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
18274 Specifies the search scope (subtree, onelevel, base or children). The
18275 default scope is subtree; base scope is almost never useful for name
18276 service lookups; children scope is not supported on all servers.
18278 Defaults to @samp{(subtree)}.
18282 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
18283 Specifies the policy for dereferencing aliases. The default policy is
18284 to never dereference aliases.
18286 Defaults to @samp{disabled}.
18290 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
18291 Specifies whether automatic referral chasing should be enabled. The
18292 default behaviour is to chase referrals.
18294 Defaults to @samp{disabled}.
18298 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
18299 This option allows for custom attributes to be looked up instead of the
18300 default RFC 2307 attributes. It is a list of maps, each consisting of
18301 the name of a map, the RFC 2307 attribute to match and the query
18302 expression for the attribute as it is available in the directory.
18304 Defaults to @samp{()}.
18308 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
18309 A list of filters consisting of the name of a map to which the filter
18310 applies and an LDAP search filter expression.
18312 Defaults to @samp{()}.
18316 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
18317 Specifies the time limit in seconds to use when connecting to the
18318 directory server. The default value is 10 seconds.
18320 Defaults to @samp{disabled}.
18324 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
18325 Specifies the time limit (in seconds) to wait for a response from the
18326 LDAP server. A value of zero, which is the default, is to wait
18327 indefinitely for searches to be completed.
18329 Defaults to @samp{disabled}.
18333 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
18334 Specifies the period if inactivity (in seconds) after which the con‐
18335 nection to the LDAP server will be closed. The default is not to time
18338 Defaults to @samp{disabled}.
18342 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
18343 Specifies the number of seconds to sleep when connecting to all LDAP
18344 servers fails. By default one second is waited between the first
18345 failure and the first retry.
18347 Defaults to @samp{disabled}.
18351 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
18352 Specifies the time after which the LDAP server is considered to be
18353 permanently unavailable. Once this time is reached retries will be done
18354 only once per this time period. The default value is 10 seconds.
18356 Defaults to @samp{disabled}.
18360 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
18361 Specifies whether to use SSL/TLS or not (the default is not to). If
18362 'start-tls is specified then StartTLS is used rather than raw LDAP over
18365 Defaults to @samp{disabled}.
18369 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
18370 Specifies what checks to perform on a server-supplied certificate. The
18371 meaning of the values is described in the ldap.conf(5) manual page.
18373 Defaults to @samp{disabled}.
18377 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
18378 Specifies the directory containing X.509 certificates for peer authen‐
18379 tication. This parameter is ignored when using GnuTLS.
18381 Defaults to @samp{disabled}.
18385 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
18386 Specifies the path to the X.509 certificate for peer authentication.
18388 Defaults to @samp{disabled}.
18392 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
18393 Specifies the path to an entropy source. This parameter is ignored when
18396 Defaults to @samp{disabled}.
18400 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
18401 Specifies the ciphers to use for TLS as a string.
18403 Defaults to @samp{disabled}.
18407 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
18408 Specifies the path to the file containing the local certificate for
18409 client TLS authentication.
18411 Defaults to @samp{disabled}.
18415 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
18416 Specifies the path to the file containing the private key for client TLS
18419 Defaults to @samp{disabled}.
18423 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
18424 Set this to a number greater than 0 to request paged results from the
18425 LDAP server in accordance with RFC2696. The default (0) is to not
18426 request paged results.
18428 Defaults to @samp{disabled}.
18432 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
18433 This option prevents group membership lookups through LDAP for the
18434 specified users. Alternatively, the value 'all-local may be used. With
18435 that value nslcd builds a full list of non-LDAP users on startup.
18437 Defaults to @samp{disabled}.
18441 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
18442 This option ensures that LDAP users with a numeric user id lower than
18443 the specified value are ignored.
18445 Defaults to @samp{disabled}.
18449 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
18450 This option specifies an offset that is added to all LDAP numeric user
18451 ids. This can be used to avoid user id collisions with local users.
18453 Defaults to @samp{disabled}.
18457 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
18458 This option specifies an offset that is added to all LDAP numeric group
18459 ids. This can be used to avoid user id collisions with local groups.
18461 Defaults to @samp{disabled}.
18465 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
18466 If this option is set, the member attribute of a group may point to
18467 another group. Members of nested groups are also returned in the higher
18468 level group and parent groups are returned when finding groups for a
18469 specific user. The default is not to perform extra searches for nested
18472 Defaults to @samp{disabled}.
18476 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
18477 If this option is set, the group member list is not retrieved when
18478 looking up groups. Lookups for finding which groups a user belongs to
18479 will remain functional so the user will likely still get the correct
18480 groups assigned on login.
18482 Defaults to @samp{disabled}.
18486 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
18487 If this option is set, functions which cause all user/group entries to
18488 be loaded from the directory will not succeed in doing so. This can
18489 dramatically reduce LDAP server load in situations where there are a
18490 great number of users and/or groups. This option is not recommended for
18491 most configurations.
18493 Defaults to @samp{disabled}.
18497 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
18498 This option can be used to specify how user and group names are verified
18499 within the system. This pattern is used to check all user and group
18500 names that are requested and returned from LDAP.
18502 Defaults to @samp{disabled}.
18506 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
18507 This specifies whether or not to perform searches using case-insensitive
18508 matching. Enabling this could open up the system to authorization
18509 bypass vulnerabilities and introduce nscd cache poisoning
18510 vulnerabilities which allow denial of service.
18512 Defaults to @samp{disabled}.
18516 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
18517 This option specifies whether password policy controls are requested and
18518 handled from the LDAP server when performing user authentication.
18520 Defaults to @samp{disabled}.
18524 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
18525 By default nslcd performs an LDAP search with the user's credentials
18526 after BIND (authentication) to ensure that the BIND operation was
18527 successful. The default search is a simple check to see if the user's
18528 DN exists. A search filter can be specified that will be used instead.
18529 It should return at least one entry.
18531 Defaults to @samp{disabled}.
18535 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
18536 This option allows flexible fine tuning of the authorisation check that
18537 should be performed. The search filter specified is executed and if any
18538 entries match, access is granted, otherwise access is denied.
18540 Defaults to @samp{disabled}.
18544 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
18545 If this option is set password modification using pam_ldap will be
18546 denied and the specified message will be presented to the user instead.
18547 The message can be used to direct the user to an alternative means of
18548 changing their password.
18550 Defaults to @samp{disabled}.
18554 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
18555 List of pam service names for which LDAP authentication should suffice.
18557 Defaults to @samp{()}.
18561 @c %end of generated documentation for nslcd-configuration
18565 @subsection Web Services
18570 The @code{(gnu services web)} module provides the Apache HTTP Server,
18571 the nginx web server, and also a fastcgi wrapper daemon.
18573 @subsubheading Apache HTTP Server
18575 @deffn {Scheme Variable} httpd-service-type
18576 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
18577 (@dfn{httpd}). The value for this service type is a
18578 @code{httpd-configuration} record.
18580 A simple example configuration is given below.
18583 (service httpd-service-type
18584 (httpd-configuration
18587 (server-name "www.example.com")
18588 (document-root "/srv/http/www.example.com")))))
18591 Other services can also extend the @code{httpd-service-type} to add to
18595 (simple-service 'my-extra-server httpd-service-type
18599 (list (string-append
18600 "ServerName "www.example.com
18601 DocumentRoot \"/srv/http/www.example.com\"")))))
18605 The details for the @code{httpd-configuration}, @code{httpd-module},
18606 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
18609 @deffn {Data Type} httpd-configuration
18610 This data type represents the configuration for the httpd service.
18613 @item @code{package} (default: @code{httpd})
18614 The httpd package to use.
18616 @item @code{pid-file} (default: @code{"/var/run/httpd"})
18617 The pid file used by the shepherd-service.
18619 @item @code{config} (default: @code{(httpd-config-file)})
18620 The configuration file to use with the httpd service. The default value
18621 is a @code{httpd-config-file} record, but this can also be a different
18622 G-expression that generates a file, for example a @code{plain-file}. A
18623 file outside of the store can also be specified through a string.
18628 @deffn {Data Type} httpd-module
18629 This data type represents a module for the httpd service.
18633 The name of the module.
18636 The file for the module. This can be relative to the httpd package being
18637 used, the absolute location of a file, or a G-expression for a file
18638 within the store, for example @code{(file-append mod-wsgi
18639 "/modules/mod_wsgi.so")}.
18644 @defvr {Scheme Variable} %default-httpd-modules
18645 A default list of @code{httpd-module} objects.
18648 @deffn {Data Type} httpd-config-file
18649 This data type represents a configuration file for the httpd service.
18652 @item @code{modules} (default: @code{%default-httpd-modules})
18653 The modules to load. Additional modules can be added here, or loaded by
18654 additional configuration.
18656 For example, in order to handle requests for PHP files, you can use Apache’s
18657 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
18660 (service httpd-service-type
18661 (httpd-configuration
18666 (name "proxy_module")
18667 (file "modules/mod_proxy.so"))
18669 (name "proxy_fcgi_module")
18670 (file "modules/mod_proxy_fcgi.so"))
18671 %default-httpd-modules))
18672 (extra-config (list "\
18673 <FilesMatch \\.php$>
18674 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
18675 </FilesMatch>"))))))
18676 (service php-fpm-service-type
18677 (php-fpm-configuration
18678 (socket "/var/run/php-fpm.sock")
18679 (socket-group "httpd")))
18682 @item @code{server-root} (default: @code{httpd})
18683 The @code{ServerRoot} in the configuration file, defaults to the httpd
18684 package. Directives including @code{Include} and @code{LoadModule} are
18685 taken as relative to the server root.
18687 @item @code{server-name} (default: @code{#f})
18688 The @code{ServerName} in the configuration file, used to specify the
18689 request scheme, hostname and port that the server uses to identify
18692 This doesn't need to be set in the server config, and can be specifyed
18693 in virtual hosts. The default is @code{#f} to not specify a
18696 @item @code{document-root} (default: @code{"/srv/http"})
18697 The @code{DocumentRoot} from which files will be served.
18699 @item @code{listen} (default: @code{'("80")})
18700 The list of values for the @code{Listen} directives in the config
18701 file. The value should be a list of strings, when each string can
18702 specify the port number to listen on, and optionally the IP address and
18705 @item @code{pid-file} (default: @code{"/var/run/httpd"})
18706 The @code{PidFile} to use. This should match the @code{pid-file} set in
18707 the @code{httpd-configuration} so that the Shepherd service is
18708 configured correctly.
18710 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
18711 The @code{ErrorLog} to which the server will log errors.
18713 @item @code{user} (default: @code{"httpd"})
18714 The @code{User} which the server will answer requests as.
18716 @item @code{group} (default: @code{"httpd"})
18717 The @code{Group} which the server will answer requests as.
18719 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
18720 A flat list of strings and G-expressions which will be added to the end
18721 of the configuration file.
18723 Any values which the service is extended with will be appended to this
18729 @deffn {Data Type} httpd-virtualhost
18730 This data type represents a virtualhost configuration block for the httpd service.
18732 These should be added to the extra-config for the httpd-service.
18735 (simple-service 'my-extra-server httpd-service-type
18739 (list (string-append
18740 "ServerName "www.example.com
18741 DocumentRoot \"/srv/http/www.example.com\"")))))
18745 @item @code{addresses-and-ports}
18746 The addresses and ports for the @code{VirtualHost} directive.
18748 @item @code{contents}
18749 The contents of the @code{VirtualHost} directive, this should be a list
18750 of strings and G-expressions.
18755 @subsubheading NGINX
18757 @deffn {Scheme Variable} nginx-service-type
18758 Service type for the @uref{https://nginx.org/,NGinx} web server. The
18759 value for this service type is a @code{<nginx-configuration>} record.
18761 A simple example configuration is given below.
18764 (service nginx-service-type
18765 (nginx-configuration
18767 (list (nginx-server-configuration
18768 (server-name '("www.example.com"))
18769 (root "/srv/http/www.example.com"))))))
18772 In addition to adding server blocks to the service configuration
18773 directly, this service can be extended by other services to add server
18774 blocks, as in this example:
18777 (simple-service 'my-extra-server nginx-service-type
18778 (list (nginx-server-configuration
18779 (root "/srv/http/extra-website")
18780 (try-files (list "$uri" "$uri/index.html")))))
18784 At startup, @command{nginx} has not yet read its configuration file, so
18785 it uses a default file to log error messages. If it fails to load its
18786 configuration file, that is where error messages are logged. After the
18787 configuration file is loaded, the default error log file changes as per
18788 configuration. In our case, startup error messages can be found in
18789 @file{/var/run/nginx/logs/error.log}, and after configuration in
18790 @file{/var/log/nginx/error.log}. The second location can be changed
18791 with the @var{log-directory} configuration option.
18793 @deffn {Data Type} nginx-configuration
18794 This data type represents the configuration for NGinx. Some
18795 configuration can be done through this and the other provided record
18796 types, or alternatively, a config file can be provided.
18799 @item @code{nginx} (default: @code{nginx})
18800 The nginx package to use.
18802 @item @code{log-directory} (default: @code{"/var/log/nginx"})
18803 The directory to which NGinx will write log files.
18805 @item @code{run-directory} (default: @code{"/var/run/nginx"})
18806 The directory in which NGinx will create a pid file, and write temporary
18809 @item @code{server-blocks} (default: @code{'()})
18810 A list of @dfn{server blocks} to create in the generated configuration
18811 file, the elements should be of type
18812 @code{<nginx-server-configuration>}.
18814 The following example would setup NGinx to serve @code{www.example.com}
18815 from the @code{/srv/http/www.example.com} directory, without using
18818 (service nginx-service-type
18819 (nginx-configuration
18821 (list (nginx-server-configuration
18822 (server-name '("www.example.com"))
18823 (root "/srv/http/www.example.com"))))))
18826 @item @code{upstream-blocks} (default: @code{'()})
18827 A list of @dfn{upstream blocks} to create in the generated configuration
18828 file, the elements should be of type
18829 @code{<nginx-upstream-configuration>}.
18831 Configuring upstreams through the @code{upstream-blocks} can be useful
18832 when combined with @code{locations} in the
18833 @code{<nginx-server-configuration>} records. The following example
18834 creates a server configuration with one location configuration, that
18835 will proxy requests to a upstream configuration, which will handle
18836 requests with two servers.
18841 (nginx-configuration
18843 (list (nginx-server-configuration
18844 (server-name '("www.example.com"))
18845 (root "/srv/http/www.example.com")
18848 (nginx-location-configuration
18850 (body '("proxy_pass http://server-proxy;"))))))))
18852 (list (nginx-upstream-configuration
18853 (name "server-proxy")
18854 (servers (list "server1.example.com"
18855 "server2.example.com")))))))
18858 @item @code{file} (default: @code{#f})
18859 If a configuration @var{file} is provided, this will be used, rather than
18860 generating a configuration file from the provided @code{log-directory},
18861 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
18862 proper operation, these arguments should match what is in @var{file} to ensure
18863 that the directories are created when the service is activated.
18865 This can be useful if you have an existing configuration file, or it's
18866 not possible to do what is required through the other parts of the
18867 nginx-configuration record.
18869 @item @code{server-names-hash-bucket-size} (default: @code{#f})
18870 Bucket size for the server names hash tables, defaults to @code{#f} to
18871 use the size of the processors cache line.
18873 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
18874 Maximum bucket size for the server names hash tables.
18876 @item @code{extra-content} (default: @code{""})
18877 Extra content for the @code{http} block. Should be string or a string
18878 valued G-expression.
18883 @deftp {Data Type} nginx-server-configuration
18884 Data type representing the configuration of an nginx server block.
18885 This type has the following parameters:
18888 @item @code{listen} (default: @code{'("80" "443 ssl")})
18889 Each @code{listen} directive sets the address and port for IP, or the
18890 path for a UNIX-domain socket on which the server will accept requests.
18891 Both address and port, or only address or only port can be specified.
18892 An address may also be a hostname, for example:
18895 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
18898 @item @code{server-name} (default: @code{(list 'default)})
18899 A list of server names this server represents. @code{'default} represents the
18900 default server for connections matching no other server.
18902 @item @code{root} (default: @code{"/srv/http"})
18903 Root of the website nginx will serve.
18905 @item @code{locations} (default: @code{'()})
18906 A list of @dfn{nginx-location-configuration} or
18907 @dfn{nginx-named-location-configuration} records to use within this
18910 @item @code{index} (default: @code{(list "index.html")})
18911 Index files to look for when clients ask for a directory. If it cannot be found,
18912 Nginx will send the list of files in the directory.
18914 @item @code{try-files} (default: @code{'()})
18915 A list of files whose existence is checked in the specified order.
18916 @code{nginx} will use the first file it finds to process the request.
18918 @item @code{ssl-certificate} (default: @code{#f})
18919 Where to find the certificate for secure connections. Set it to @code{#f} if
18920 you don't have a certificate or you don't want to use HTTPS.
18922 @item @code{ssl-certificate-key} (default: @code{#f})
18923 Where to find the private key for secure connections. Set it to @code{#f} if
18924 you don't have a key or you don't want to use HTTPS.
18926 @item @code{server-tokens?} (default: @code{#f})
18927 Whether the server should add its configuration to response.
18929 @item @code{raw-content} (default: @code{'()})
18930 A list of raw lines added to the server block.
18935 @deftp {Data Type} nginx-upstream-configuration
18936 Data type representing the configuration of an nginx @code{upstream}
18937 block. This type has the following parameters:
18941 Name for this group of servers.
18943 @item @code{servers}
18944 Specify the addresses of the servers in the group. The address can be
18945 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
18946 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
18947 prefix @samp{unix:}. For addresses using an IP address or domain name,
18948 the default port is 80, and a different port can be specified
18954 @deftp {Data Type} nginx-location-configuration
18955 Data type representing the configuration of an nginx @code{location}
18956 block. This type has the following parameters:
18960 URI which this location block matches.
18962 @anchor{nginx-location-configuration body}
18964 Body of the location block, specified as a list of strings. This can contain
18966 configuration directives. For example, to pass requests to a upstream
18967 server group defined using an @code{nginx-upstream-configuration} block,
18968 the following directive would be specified in the body @samp{(list "proxy_pass
18969 http://upstream-name;")}.
18974 @deftp {Data Type} nginx-named-location-configuration
18975 Data type representing the configuration of an nginx named location
18976 block. Named location blocks are used for request redirection, and not
18977 used for regular request processing. This type has the following
18982 Name to identify this location block.
18985 @xref{nginx-location-configuration body}, as the body for named location
18986 blocks can be used in a similar way to the
18987 @code{nginx-location-configuration body}. One restriction is that the
18988 body of a named location block cannot contain location blocks.
18993 @subsubheading Varnish Cache
18995 Varnish is a fast cache server that sits in between web applications
18996 and end users. It proxies requests from clients and caches the
18997 accessed URLs such that multiple requests for the same resource only
18998 creates one request to the back-end.
19000 @defvr {Scheme Variable} varnish-service-type
19001 Service type for the Varnish daemon.
19004 @deftp {Data Type} varnish-configuration
19005 Data type representing the @code{varnish} service configuration.
19006 This type has the following parameters:
19009 @item @code{package} (default: @code{varnish})
19010 The Varnish package to use.
19012 @item @code{name} (default: @code{"default"})
19013 A name for this Varnish instance. Varnish will create a directory in
19014 @file{/var/varnish/} with this name and keep temporary files there. If
19015 the name starts with a forward slash, it is interpreted as an absolute
19018 Pass the @code{-n} argument to other Varnish programs to connect to the
19019 named instance, e.g.@: @command{varnishncsa -n default}.
19021 @item @code{backend} (default: @code{"localhost:8080"})
19022 The backend to use. This option has no effect if @code{vcl} is set.
19024 @item @code{vcl} (default: #f)
19025 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
19026 is @code{#f}, Varnish will proxy @code{backend} using the default
19027 configuration. Otherwise this must be a file-like object with valid
19030 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
19031 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
19032 can do something along these lines:
19035 (define %gnu-mirror
19039 backend gnu @{ .host = "www.gnu.org"; @}"))
19043 (services (cons (service varnish-service-type
19044 (varnish-configuration
19046 (vcl %gnu-mirror)))
19050 The configuration of an already running Varnish instance can be inspected
19051 and changed using the @command{varnishadm} program.
19053 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
19054 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
19055 comprehensive documentation on Varnish and its configuration language.
19057 @item @code{listen} (default: @code{'("localhost:80")})
19058 List of addresses Varnish will listen on.
19060 @item @code{storage} (default: @code{'("malloc,128m")})
19061 List of storage backends that will be available in VCL.
19063 @item @code{parameters} (default: @code{'()})
19064 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
19066 @item @code{extra-options} (default: @code{'()})
19067 Additional arguments to pass to the @command{varnishd} process.
19072 @subsubheading FastCGI
19075 FastCGI is an interface between the front-end and the back-end of a web
19076 service. It is a somewhat legacy facility; new web services should
19077 generally just talk HTTP between the front-end and the back-end.
19078 However there are a number of back-end services such as PHP or the
19079 optimized HTTP Git repository access that use FastCGI, so we have
19080 support for it in Guix.
19082 To use FastCGI, you configure the front-end web server (e.g., nginx) to
19083 dispatch some subset of its requests to the fastcgi backend, which
19084 listens on a local TCP or UNIX socket. There is an intermediary
19085 @code{fcgiwrap} program that sits between the actual backend process and
19086 the web server. The front-end indicates which backend program to run,
19087 passing that information to the @code{fcgiwrap} process.
19089 @defvr {Scheme Variable} fcgiwrap-service-type
19090 A service type for the @code{fcgiwrap} FastCGI proxy.
19093 @deftp {Data Type} fcgiwrap-configuration
19094 Data type representing the configuration of the @code{fcgiwrap} service.
19095 This type has the following parameters:
19097 @item @code{package} (default: @code{fcgiwrap})
19098 The fcgiwrap package to use.
19100 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
19101 The socket on which the @code{fcgiwrap} process should listen, as a
19102 string. Valid @var{socket} values include
19103 @code{unix:@var{/path/to/unix/socket}},
19104 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
19105 @code{tcp6:[@var{ipv6_addr}]:port}.
19107 @item @code{user} (default: @code{fcgiwrap})
19108 @itemx @code{group} (default: @code{fcgiwrap})
19109 The user and group names, as strings, under which to run the
19110 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
19111 the user asks for the specific user or group names @code{fcgiwrap} that
19112 the corresponding user and/or group is present on the system.
19114 It is possible to configure a FastCGI-backed web service to pass HTTP
19115 authentication information from the front-end to the back-end, and to
19116 allow @code{fcgiwrap} to run the back-end process as a corresponding
19117 local user. To enable this capability on the back-end., run
19118 @code{fcgiwrap} as the @code{root} user and group. Note that this
19119 capability also has to be configured on the front-end as well.
19124 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
19125 with some additional features useful for sites of any size.
19127 These features include:
19129 @item Adaptive process spawning
19130 @item Basic statistics (similar to Apache's mod_status)
19131 @item Advanced process management with graceful stop/start
19132 @item Ability to start workers with different uid/gid/chroot/environment
19133 and different php.ini (replaces safe_mode)
19134 @item Stdout & stderr logging
19135 @item Emergency restart in case of accidental opcode cache destruction
19136 @item Accelerated upload support
19137 @item Support for a "slowlog"
19138 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
19139 a special function to finish request & flush all data while continuing to do
19140 something time-consuming (video converting, stats processing, etc.)
19142 ...@: and much more.
19144 @defvr {Scheme Variable} php-fpm-service-type
19145 A Service type for @code{php-fpm}.
19148 @deftp {Data Type} php-fpm-configuration
19149 Data Type for php-fpm service configuration.
19151 @item @code{php} (default: @code{php})
19152 The php package to use.
19153 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
19154 The address on which to accept FastCGI requests. Valid syntaxes are:
19156 @item @code{"ip.add.re.ss:port"}
19157 Listen on a TCP socket to a specific address on a specific port.
19158 @item @code{"port"}
19159 Listen on a TCP socket to all addresses on a specific port.
19160 @item @code{"/path/to/unix/socket"}
19161 Listen on a unix socket.
19164 @item @code{user} (default: @code{php-fpm})
19165 User who will own the php worker processes.
19166 @item @code{group} (default: @code{php-fpm})
19167 Group of the worker processes.
19168 @item @code{socket-user} (default: @code{php-fpm})
19169 User who can speak to the php-fpm socket.
19170 @item @code{socket-group} (default: @code{php-fpm})
19171 Group that can speak to the php-fpm socket.
19172 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
19173 The process id of the php-fpm process is written to this file
19174 once the service has started.
19175 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
19176 Log for the php-fpm master process.
19177 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
19178 Detailed settings for the php-fpm process manager.
19181 @item @code{<php-fpm-dynamic-process-manager-configuration>}
19182 @item @code{<php-fpm-static-process-manager-configuration>}
19183 @item @code{<php-fpm-on-demand-process-manager-configuration>}
19185 @item @code{display-errors} (default @code{#f})
19186 Determines whether php errors and warning should be sent to clients
19187 and displayed in their browsers.
19188 This is useful for local php development, but a security risk for public sites,
19189 as error messages can reveal passwords and personal data.
19190 @item @code{timezone} (default @code{#f})
19191 Specifies @code{php_admin_value[date.timezone]} parameter.
19192 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
19193 This file will log the @code{stderr} outputs of php worker processes.
19194 Can be set to @code{#f} to disable logging.
19195 @item @code{file} (default @code{#f})
19196 An optional override of the whole configuration.
19197 You can use the @code{mixed-text-file} function or an absolute filepath for it.
19201 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
19202 Data Type for the @code{dynamic} php-fpm process manager. With the
19203 @code{dynamic} process manager, spare worker processes are kept around
19204 based on it's configured limits.
19206 @item @code{max-children} (default: @code{5})
19207 Maximum of worker processes.
19208 @item @code{start-servers} (default: @code{2})
19209 How many worker processes should be started on start-up.
19210 @item @code{min-spare-servers} (default: @code{1})
19211 How many spare worker processes should be kept around at minimum.
19212 @item @code{max-spare-servers} (default: @code{3})
19213 How many spare worker processes should be kept around at maximum.
19217 @deftp {Data type} php-fpm-static-process-manager-configuration
19218 Data Type for the @code{static} php-fpm process manager. With the
19219 @code{static} process manager, an unchanging number of worker processes
19222 @item @code{max-children} (default: @code{5})
19223 Maximum of worker processes.
19227 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
19228 Data Type for the @code{on-demand} php-fpm process manager. With the
19229 @code{on-demand} process manager, worker processes are only created as
19232 @item @code{max-children} (default: @code{5})
19233 Maximum of worker processes.
19234 @item @code{process-idle-timeout} (default: @code{10})
19235 The time in seconds after which a process with no requests is killed.
19240 @deffn {Scheme Procedure} nginx-php-fpm-location @
19241 [#:nginx-package nginx] @
19242 [socket (string-append "/var/run/php" @
19243 (version-major (package-version php)) @
19245 A helper function to quickly add php to an @code{nginx-server-configuration}.
19248 A simple services setup for nginx with php can look like this:
19250 (services (cons* (service dhcp-client-service-type)
19251 (service php-fpm-service-type)
19252 (service nginx-service-type
19253 (nginx-server-configuration
19254 (server-name '("example.com"))
19255 (root "/srv/http/")
19257 (list (nginx-php-location)))
19259 (ssl-certificate #f)
19260 (ssl-certificate-key #f)))
19264 @cindex cat-avatar-generator
19265 The cat avatar generator is a simple service to demonstrate the use of php-fpm
19266 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
19267 the hash of a user's email address.
19269 @deffn {Scheme Procedure} cat-avatar-generator-service @
19270 [#:cache-dir "/var/cache/cat-avatar-generator"] @
19271 [#:package cat-avatar-generator] @
19272 [#:configuration (nginx-server-configuration)]
19273 Returns an nginx-server-configuration that inherits @code{configuration}. It
19274 extends the nginx configuration to add a server block that serves @code{package},
19275 a version of cat-avatar-generator. During execution, cat-avatar-generator will
19276 be able to use @code{cache-dir} as its cache directory.
19279 A simple setup for cat-avatar-generator can look like this:
19281 (services (cons* (cat-avatar-generator-service
19283 (nginx-server-configuration
19284 (server-name '("example.com"))))
19289 @subsubheading Hpcguix-web
19291 @cindex hpcguix-web
19292 The @uref{hpcguix-web, https://github.com/UMCUGenetics/hpcguix-web/}
19293 program is a customizable web interface to browse Guix packages,
19294 initially designed for users of high-performance computing (HPC)
19297 @defvr {Scheme Variable} hpcguix-web-service-type
19298 The service type for @code{hpcguix-web}.
19301 @deftp {Data Type} hpcguix-web-configuration
19302 Data type for the hpcguix-web service configuration.
19306 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
19307 configuration. The main items available in this spec are:
19310 @item @code{title-prefix} (default: @code{"hpcguix | "})
19311 The page title prefix.
19313 @item @code{guix-command} (default: @code{"guix"})
19314 The @command{guix} command.
19316 @item @code{package-filter-proc} (default: @code{(const #t)})
19317 A procedure specifying how to filter packages that are displayed.
19319 @item @code{package-page-extension-proc} (default: @code{(const '())})
19320 Extension package for @code{hpcguix-web}.
19322 @item @code{menu} (default: @code{'()})
19323 Additional entry in page @code{menu}.
19325 @item @code{channels} (default: @code{%default-channels})
19326 List of channels from which the package list is built (@pxref{Channels}).
19328 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
19329 The expiration time, in seconds, after which the package list is rebuilt from
19330 the latest instances of the given channels.
19333 See the hpcguix-web repository for a
19334 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
19337 @item @code{package} (default: @code{hpcguix-web})
19338 The hpcguix-web package to use.
19342 A typical hpcguix-web service declaration looks like this:
19345 (service hpcguix-web-service-type
19346 (hpcguix-web-configuration
19348 #~(define site-config
19349 (hpcweb-configuration
19350 (title-prefix "Guix-HPC - ")
19351 (menu '(("/about" "ABOUT"))))))))
19355 The hpcguix-web service periodically updates the package list it publishes by
19356 pulling channels from Git. To that end, it needs to access X.509 certificates
19357 so that it can authenticate Git servers when communicating over HTTPS, and it
19358 assumes that @file{/etc/ssl/certs} contains those certificates.
19360 Thus, make sure to add @code{nss-certs} or another certificate package to the
19361 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
19362 more information on X.509 certificates.
19365 @node Certificate Services
19366 @subsection Certificate Services
19369 @cindex HTTP, HTTPS
19370 @cindex Let's Encrypt
19371 @cindex TLS certificates
19372 The @code{(gnu services certbot)} module provides a service to
19373 automatically obtain a valid TLS certificate from the Let's Encrypt
19374 certificate authority. These certificates can then be used to serve
19375 content securely over HTTPS or other TLS-based protocols, with the
19376 knowledge that the client will be able to verify the server's
19379 @url{https://letsencrypt.org/, Let's Encrypt} provides the
19380 @code{certbot} tool to automate the certification process. This tool
19381 first securely generates a key on the server. It then makes a request
19382 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
19383 checks that the request originates from the host in question by using a
19384 challenge-response protocol, requiring the server to provide its
19385 response over HTTP. If that protocol completes successfully, the CA
19386 signs the key, resulting in a certificate. That certificate is valid
19387 for a limited period of time, and therefore to continue to provide TLS
19388 services, the server needs to periodically ask the CA to renew its
19391 The certbot service automates this process: the initial key
19392 generation, the initial certification request to the Let's Encrypt
19393 service, the web server challenge/response integration, writing the
19394 certificate to disk, the automated periodic renewals, and the deployment
19395 tasks associated with the renewal (e.g.@: reloading services, copying keys
19396 with different permissions).
19398 Certbot is run twice a day, at a random minute within the hour. It
19399 won't do anything until your certificates are due for renewal or
19400 revoked, but running it regularly would give your service a chance of
19401 staying online in case a Let's Encrypt-initiated revocation happened for
19404 By using this service, you agree to the ACME Subscriber Agreement, which
19405 can be found there:
19406 @url{https://acme-v01.api.letsencrypt.org/directory}.
19408 @defvr {Scheme Variable} certbot-service-type
19409 A service type for the @code{certbot} Let's Encrypt client. Its value
19410 must be a @code{certbot-configuration} record as in this example:
19413 (define %nginx-deploy-hook
19415 "nginx-deploy-hook"
19416 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
19417 (kill pid SIGHUP))))
19419 (service certbot-service-type
19420 (certbot-configuration
19421 (email "foo@@example.net")
19424 (certificate-configuration
19425 (domains '("example.net" "www.example.net"))
19426 (deploy-hook %nginx-deploy-hook))
19427 (certificate-configuration
19428 (domains '("bar.example.net")))))))
19431 See below for details about @code{certbot-configuration}.
19434 @deftp {Data Type} certbot-configuration
19435 Data type representing the configuration of the @code{certbot} service.
19436 This type has the following parameters:
19439 @item @code{package} (default: @code{certbot})
19440 The certbot package to use.
19442 @item @code{webroot} (default: @code{/var/www})
19443 The directory from which to serve the Let's Encrypt challenge/response
19446 @item @code{certificates} (default: @code{()})
19447 A list of @code{certificates-configuration}s for which to generate
19448 certificates and request signatures. Each certificate has a @code{name}
19449 and several @code{domains}.
19452 Mandatory email used for registration, recovery contact, and important
19453 account notifications.
19455 @item @code{rsa-key-size} (default: @code{2048})
19456 Size of the RSA key.
19458 @item @code{default-location} (default: @i{see below})
19459 The default @code{nginx-location-configuration}. Because @code{certbot}
19460 needs to be able to serve challenges and responses, it needs to be able
19461 to run a web server. It does so by extending the @code{nginx} web
19462 service with an @code{nginx-server-configuration} listening on the
19463 @var{domains} on port 80, and which has a
19464 @code{nginx-location-configuration} for the @code{/.well-known/} URI
19465 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
19466 these nginx configuration data types.
19468 Requests to other URL paths will be matched by the
19469 @code{default-location}, which if present is added to all
19470 @code{nginx-server-configuration}s.
19472 By default, the @code{default-location} will issue a redirect from
19473 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
19474 you to define what to serve on your site via @code{https}.
19476 Pass @code{#f} to not issue a default location.
19480 @deftp {Data Type} certificate-configuration
19481 Data type representing the configuration of a certificate.
19482 This type has the following parameters:
19485 @item @code{name} (default: @i{see below})
19486 This name is used by Certbot for housekeeping and in file paths; it
19487 doesn't affect the content of the certificate itself. To see
19488 certificate names, run @code{certbot certificates}.
19490 Its default is the first provided domain.
19492 @item @code{domains} (default: @code{()})
19493 The first domain provided will be the subject CN of the certificate, and
19494 all domains will be Subject Alternative Names on the certificate.
19496 @item @code{challenge} (default: @code{#f})
19497 The challenge type that has to be run by certbot. If @code{#f} is specified,
19498 default to the HTTP challenge. If a value is specified, defaults to the
19499 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
19500 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}).
19502 @item @code{authentication-hook} (default: @code{#f})
19503 Command to be run in a shell once for each certificate challenge to be
19504 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
19505 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
19506 contains the validation string and @code{$CERTBOT_TOKEN} contains the
19507 file name of the resource requested when performing an HTTP-01 challenge.
19509 @item @code{cleanup-hook} (default: @code{#f})
19510 Command to be run in a shell once for each certificate challenge that
19511 have been answered by the @code{auth-hook}. For this command, the shell
19512 variables available in the @code{auth-hook} script are still available, and
19513 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
19514 of the @code{auth-hook} script.
19516 @item @code{deploy-hook} (default: @code{#f})
19517 Command to be run in a shell once for each successfully issued
19518 certificate. For this command, the shell variable
19519 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
19520 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
19521 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
19522 contain a space-delimited list of renewed certificate domains (for
19523 example, @samp{"example.com www.example.com"}.
19528 For each @code{certificate-configuration}, the certificate is saved to
19529 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
19530 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
19532 @subsection DNS Services
19533 @cindex DNS (domain name system)
19534 @cindex domain name system (DNS)
19536 The @code{(gnu services dns)} module provides services related to the
19537 @dfn{domain name system} (DNS). It provides a server service for hosting
19538 an @emph{authoritative} DNS server for multiple zones, slave or master.
19539 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
19540 caching and forwarding DNS server for the LAN, which uses
19541 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
19543 @subsubheading Knot Service
19545 An example configuration of an authoritative server for two zones, one master
19549 (define-zone-entries example.org.zone
19550 ;; Name TTL Class Type Data
19551 ("@@" "" "IN" "A" "127.0.0.1")
19552 ("@@" "" "IN" "NS" "ns")
19553 ("ns" "" "IN" "A" "127.0.0.1"))
19555 (define master-zone
19556 (knot-zone-configuration
19557 (domain "example.org")
19559 (origin "example.org")
19560 (entries example.org.zone)))))
19563 (knot-zone-configuration
19564 (domain "plop.org")
19565 (dnssec-policy "default")
19566 (master (list "plop-master"))))
19568 (define plop-master
19569 (knot-remote-configuration
19571 (address (list "208.76.58.171"))))
19575 (services (cons* (service knot-service-type
19576 (knot-configuration
19577 (remotes (list plop-master))
19578 (zones (list master-zone slave-zone))))
19583 @deffn {Scheme Variable} knot-service-type
19584 This is the type for the Knot DNS server.
19586 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
19587 zones, that is to say domain names you would buy from a registrar. This server
19588 is not a resolver, meaning that it can only resolve names for which it is
19589 authoritative. This server can be configured to serve zones as a master server
19590 or a slave server as a per-zone basis. Slave zones will get their data from
19591 masters, and will serve it as an authoritative server. From the point of view
19592 of a resolver, there is no difference between master and slave.
19594 The following data types are used to configure the Knot DNS server:
19597 @deftp {Data Type} knot-key-configuration
19598 Data type representing a key.
19599 This type has the following parameters:
19602 @item @code{id} (default: @code{""})
19603 An identifier for other configuration fields to refer to this key. IDs must
19604 be unique and must not be empty.
19606 @item @code{algorithm} (default: @code{#f})
19607 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
19608 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
19609 and @code{'hmac-sha512}.
19611 @item @code{secret} (default: @code{""})
19612 The secret key itself.
19617 @deftp {Data Type} knot-acl-configuration
19618 Data type representing an Access Control List (ACL) configuration.
19619 This type has the following parameters:
19622 @item @code{id} (default: @code{""})
19623 An identifier for ether configuration fields to refer to this key. IDs must be
19624 unique and must not be empty.
19626 @item @code{address} (default: @code{'()})
19627 An ordered list of IP addresses, network subnets, or network ranges represented
19628 with strings. The query must match one of them. Empty value means that
19629 address match is not required.
19631 @item @code{key} (default: @code{'()})
19632 An ordered list of references to keys represented with strings. The string
19633 must match a key ID defined in a @code{knot-key-configuration}. No key means
19634 that a key is not require to match that ACL.
19636 @item @code{action} (default: @code{'()})
19637 An ordered list of actions that are permitted or forbidden by this ACL. Possible
19638 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
19639 and @code{'update}.
19641 @item @code{deny?} (default: @code{#f})
19642 When true, the ACL defines restrictions. Listed actions are forbidden. When
19643 false, listed actions are allowed.
19648 @deftp {Data Type} zone-entry
19649 Data type represnting a record entry in a zone file.
19650 This type has the following parameters:
19653 @item @code{name} (default: @code{"@@"})
19654 The name of the record. @code{"@@"} refers to the origin of the zone. Names
19655 are relative to the origin of the zone. For example, in the @code{example.org}
19656 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
19657 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
19658 refers to @code{ns.example.org}.
19660 @item @code{ttl} (default: @code{""})
19661 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
19663 @item @code{class} (default: @code{"IN"})
19664 The class of the record. Knot currently supports only @code{"IN"} and
19665 partially @code{"CH"}.
19667 @item @code{type} (default: @code{"A"})
19668 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
19669 address), NS (Name Server) and MX (Mail eXchange). Many other types are
19672 @item @code{data} (default: @code{""})
19673 The data contained in the record. For instance an IP address associated with
19674 an A record, or a domain name associated with an NS record. Remember that
19675 domain names are relative to the origin unless they end with a dot.
19680 @deftp {Data Type} zone-file
19681 Data type representing the content of a zone file.
19682 This type has the following parameters:
19685 @item @code{entries} (default: @code{'()})
19686 The list of entries. The SOA record is taken care of, so you don't need to
19687 put it in the list of entries. This list should probably contain an entry
19688 for your primary authoritative DNS server. Other than using a list of entries
19689 directly, you can use @code{define-zone-entries} to define a object containing
19690 the list of entries more easily, that you can later pass to the @code{entries}
19691 field of the @code{zone-file}.
19693 @item @code{origin} (default: @code{""})
19694 The name of your zone. This parameter cannot be empty.
19696 @item @code{ns} (default: @code{"ns"})
19697 The domain of your primary authoritative DNS server. The name is relative to
19698 the origin, unless it ends with a dot. It is mandatory that this primary
19699 DNS server corresponds to an NS record in the zone and that it is associated
19700 to an IP address in the list of entries.
19702 @item @code{mail} (default: @code{"hostmaster"})
19703 An email address people can contact you at, as the owner of the zone. This
19704 is translated as @code{<mail>@@<origin>}.
19706 @item @code{serial} (default: @code{1})
19707 The serial number of the zone. As this is used to keep track of changes by
19708 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
19709 Always increment it when you make a change in your zone.
19711 @item @code{refresh} (default: @code{(* 2 24 3600)})
19712 The frequency at which slaves will do a zone transfer. This value is a number
19713 of seconds. It can be computed by multiplications or with
19714 @code{(string->duration)}.
19716 @item @code{retry} (default: @code{(* 15 60)})
19717 The period after which a slave will retry to contact its master when it fails
19718 to do so a first time.
19720 @item @code{expiry} (default: @code{(* 14 24 3600)})
19721 Default TTL of records. Existing records are considered correct for at most
19722 this amount of time. After this period, resolvers will invalidate their cache
19723 and check again that it still exists.
19725 @item @code{nx} (default: @code{3600})
19726 Default TTL of inexistant records. This delay is usually short because you want
19727 your new domains to reach everyone quickly.
19732 @deftp {Data Type} knot-remote-configuration
19733 Data type representing a remote configuration.
19734 This type has the following parameters:
19737 @item @code{id} (default: @code{""})
19738 An identifier for other configuration fields to refer to this remote. IDs must
19739 be unique and must not be empty.
19741 @item @code{address} (default: @code{'()})
19742 An ordered list of destination IP addresses. Addresses are tried in sequence.
19743 An optional port can be given with the @@ separator. For instance:
19744 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
19746 @item @code{via} (default: @code{'()})
19747 An ordered list of source IP addresses. An empty list will have Knot choose
19748 an appropriate source IP. An optional port can be given with the @@ separator.
19749 The default is to choose at random.
19751 @item @code{key} (default: @code{#f})
19752 A reference to a key, that is a string containing the identifier of a key
19753 defined in a @code{knot-key-configuration} field.
19758 @deftp {Data Type} knot-keystore-configuration
19759 Data type representing a keystore to hold dnssec keys.
19760 This type has the following parameters:
19763 @item @code{id} (default: @code{""})
19764 The id of the keystore. It must not be empty.
19766 @item @code{backend} (default: @code{'pem})
19767 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
19769 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
19770 The configuration string of the backend. An example for the PKCS#11 is:
19771 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
19772 For the pem backend, the string reprensents a path in the file system.
19777 @deftp {Data Type} knot-policy-configuration
19778 Data type representing a dnssec policy. Knot DNS is able to automatically
19779 sign your zones. It can either generate and manage your keys automatically or
19780 use keys that you generate.
19782 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
19783 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
19784 zone. In order to be trusted, the KSK needs to be present in the parent zone
19785 (usually a top-level domain). If your registrar supports dnssec, you will
19786 have to send them your KSK's hash so they can add a DS record in their zone.
19787 This is not automated and need to be done each time you change your KSK.
19789 The policy also defines the lifetime of keys. Usually, ZSK can be changed
19790 easily and use weaker cryptographic functions (they use lower parameters) in
19791 order to sign records quickly, so they are changed often. The KSK however
19792 requires manual interaction with the registrar, so they are changed less often
19793 and use stronger parameters because they sign only one record.
19795 This type has the following parameters:
19798 @item @code{id} (default: @code{""})
19799 The id of the policy. It must not be empty.
19801 @item @code{keystore} (default: @code{"default"})
19802 A reference to a keystore, that is a string containing the identifier of a
19803 keystore defined in a @code{knot-keystore-configuration} field. The
19804 @code{"default"} identifier means the default keystore (a kasp database that
19805 was setup by this service).
19807 @item @code{manual?} (default: @code{#f})
19808 Whether the key management is manual or automatic.
19810 @item @code{single-type-signing?} (default: @code{#f})
19811 When @code{#t}, use the Single-Type Signing Scheme.
19813 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
19814 An algorithm of signing keys and issued signatures.
19816 @item @code{ksk-size} (default: @code{256})
19817 The length of the KSK. Note that this value is correct for the default
19818 algorithm, but would be unsecure for other algorithms.
19820 @item @code{zsk-size} (default: @code{256})
19821 The length of the ZSK. Note that this value is correct for the default
19822 algorithm, but would be unsecure for other algorithms.
19824 @item @code{dnskey-ttl} (default: @code{'default})
19825 The TTL value for DNSKEY records added into zone apex. The special
19826 @code{'default} value means same as the zone SOA TTL.
19828 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
19829 The period between ZSK publication and the next rollover initiation.
19831 @item @code{propagation-delay} (default: @code{(* 24 3600)})
19832 An extra delay added for each key rollover step. This value should be high
19833 enough to cover propagation of data from the master server to all slaves.
19835 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
19836 A validity period of newly issued signatures.
19838 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
19839 A period how long before a signature expiration the signature will be refreshed.
19841 @item @code{nsec3?} (default: @code{#f})
19842 When @code{#t}, NSEC3 will be used instead of NSEC.
19844 @item @code{nsec3-iterations} (default: @code{5})
19845 The number of additional times the hashing is performed.
19847 @item @code{nsec3-salt-length} (default: @code{8})
19848 The length of a salt field in octets, which is appended to the original owner
19849 name before hashing.
19851 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
19852 The validity period of newly issued salt field.
19857 @deftp {Data Type} knot-zone-configuration
19858 Data type representing a zone served by Knot.
19859 This type has the following parameters:
19862 @item @code{domain} (default: @code{""})
19863 The domain served by this configuration. It must not be empty.
19865 @item @code{file} (default: @code{""})
19866 The file where this zone is saved. This parameter is ignored by master zones.
19867 Empty means default location that depends on the domain name.
19869 @item @code{zone} (default: @code{(zone-file)})
19870 The content of the zone file. This parameter is ignored by slave zones. It
19871 must contain a zone-file record.
19873 @item @code{master} (default: @code{'()})
19874 A list of master remotes. When empty, this zone is a master. When set, this
19875 zone is a slave. This is a list of remotes identifiers.
19877 @item @code{ddns-master} (default: @code{#f})
19878 The main master. When empty, it defaults to the first master in the list of
19881 @item @code{notify} (default: @code{'()})
19882 A list of slave remote identifiers.
19884 @item @code{acl} (default: @code{'()})
19885 A list of acl identifiers.
19887 @item @code{semantic-checks?} (default: @code{#f})
19888 When set, this adds more semantic checks to the zone.
19890 @item @code{disable-any?} (default: @code{#f})
19891 When set, this forbids queries of the ANY type.
19893 @item @code{zonefile-sync} (default: @code{0})
19894 The delay between a modification in memory and on disk. 0 means immediate
19897 @item @code{zonefile-load} (default: @code{#f})
19898 The way the zone file contents are applied during zone load. Possible values
19902 @item @code{#f} for using the default value from Knot,
19903 @item @code{'none} for not using the zone file at all,
19904 @item @code{'difference} for computing the difference between already available
19905 contents and zone contents and applying it to the current zone contents,
19906 @item @code{'difference-no-serial} for the same as @code{'difference}, but
19907 ignoring the SOA serial in the zone file, while the server takes care of it
19909 @item @code{'whole} for loading zone contents from the zone file.
19912 @item @code{journal-content} (default: @code{#f})
19913 The way the journal is used to store zone and its changes. Possible values
19914 are @code{'none} to not use it at all, @code{'changes} to store changes and
19915 @code{'all} to store contents. @code{#f} does not set this option, so the
19916 default value from Knot is used.
19918 @item @code{max-journal-usage} (default: @code{#f})
19919 The maximum size for the journal on disk. @code{#f} does not set this option,
19920 so the default value from Knot is used.
19922 @item @code{max-journal-depth} (default: @code{#f})
19923 The maximum size of the history. @code{#f} does not set this option, so the
19924 default value from Knot is used.
19926 @item @code{max-zone-size} (default: @code{#f})
19927 The maximum size of the zone file. This limit is enforced for incoming
19928 transfer and updates. @code{#f} does not set this option, so the default
19929 value from Knot is used.
19931 @item @code{dnssec-policy} (default: @code{#f})
19932 A reference to a @code{knot-policy-configuration} record, or the special
19933 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
19936 @item @code{serial-policy} (default: @code{'increment})
19937 A policy between @code{'increment} and @code{'unixtime}.
19942 @deftp {Data Type} knot-configuration
19943 Data type representing the Knot configuration.
19944 This type has the following parameters:
19947 @item @code{knot} (default: @code{knot})
19950 @item @code{run-directory} (default: @code{"/var/run/knot"})
19951 The run directory. This directory will be used for pid file and sockets.
19953 @item @code{includes} (default: @code{'()})
19954 A list of strings or file-like objects denoting other files that must be
19955 included at the top of the configuration file.
19957 @cindex secrets, Knot service
19958 This can be used to manage secrets out-of-band. For example, secret
19959 keys may be stored in an out-of-band file not managed by Guix, and
19960 thus not visible in @file{/gnu/store}---e.g., you could store secret
19961 key configuration in @file{/etc/knot/secrets.conf} and add this file
19962 to the @code{includes} list.
19964 It can also be used to add configuration not supported by this interface.
19966 @item @code{listen-v4} (default: @code{"0.0.0.0"})
19967 An ip address on which to listen.
19969 @item @code{listen-v6} (default: @code{"::"})
19970 An ip address on which to listen.
19972 @item @code{listen-port} (default: @code{53})
19973 A port on which to listen.
19975 @item @code{keys} (default: @code{'()})
19976 The list of knot-key-configuration used by this configuration.
19978 @item @code{acls} (default: @code{'()})
19979 The list of knot-acl-configuration used by this configuration.
19981 @item @code{remotes} (default: @code{'()})
19982 The list of knot-remote-configuration used by this configuration.
19984 @item @code{zones} (default: @code{'()})
19985 The list of knot-zone-configuration used by this configuration.
19990 @subsubheading Dnsmasq Service
19992 @deffn {Scheme Variable} dnsmasq-service-type
19993 This is the type of the dnsmasq service, whose value should be an
19994 @code{dnsmasq-configuration} object as in this example:
19997 (service dnsmasq-service-type
19998 (dnsmasq-configuration
20000 (servers '("192.168.1.1"))))
20004 @deftp {Data Type} dnsmasq-configuration
20005 Data type representing the configuration of dnsmasq.
20008 @item @code{package} (default: @var{dnsmasq})
20009 Package object of the dnsmasq server.
20011 @item @code{no-hosts?} (default: @code{#f})
20012 When true, don't read the hostnames in /etc/hosts.
20014 @item @code{port} (default: @code{53})
20015 The port to listen on. Setting this to zero completely disables DNS
20016 responses, leaving only DHCP and/or TFTP functions.
20018 @item @code{local-service?} (default: @code{#t})
20019 Accept DNS queries only from hosts whose address is on a local subnet,
20020 ie a subnet for which an interface exists on the server.
20022 @item @code{listen-addresses} (default: @code{'()})
20023 Listen on the given IP addresses.
20025 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
20026 The file to read the IP address of the upstream nameservers from.
20028 @item @code{no-resolv?} (default: @code{#f})
20029 When true, don't read @var{resolv-file}.
20031 @item @code{servers} (default: @code{'()})
20032 Specify IP address of upstream servers directly.
20034 @item @code{cache-size} (default: @code{150})
20035 Set the size of dnsmasq's cache. Setting the cache size to zero
20038 @item @code{negative-cache?} (default: @code{#t})
20039 When false, disable negative caching.
20044 @subsubheading ddclient Service
20047 The ddclient service described below runs the ddclient daemon, which takes
20048 care of automatically updating DNS entries for service providers such as
20049 @uref{https://dyn.com/dns/, Dyn}.
20051 The following example show instantiates the service with its default
20055 (service ddclient-service-type)
20058 Note that ddclient needs to access credentials that are stored in a
20059 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
20060 @code{secret-file} below.) You are expected to create this file manually, in
20061 an ``out-of-band'' fashion (you @emph{could} make this file part of the
20062 service configuration, for instance by using @code{plain-file}, but it will be
20063 world-readable @i{via} @file{/gnu/store}.) See the examples in the
20064 @file{share/ddclient} directory of the @code{ddclient} package.
20066 @c %start of fragment
20068 Available @code{ddclient-configuration} fields are:
20070 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
20071 The ddclient package.
20075 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
20076 The period after which ddclient will retry to check IP and domain name.
20078 Defaults to @samp{300}.
20082 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
20083 Use syslog for the output.
20085 Defaults to @samp{#t}.
20089 @deftypevr {@code{ddclient-configuration} parameter} string mail
20092 Defaults to @samp{"root"}.
20096 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
20097 Mail failed update to user.
20099 Defaults to @samp{"root"}.
20103 @deftypevr {@code{ddclient-configuration} parameter} string pid
20104 The ddclient PID file.
20106 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
20110 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
20111 Enable SSL support.
20113 Defaults to @samp{#t}.
20117 @deftypevr {@code{ddclient-configuration} parameter} string user
20118 Specifies the user name or ID that is used when running ddclient
20121 Defaults to @samp{"ddclient"}.
20125 @deftypevr {@code{ddclient-configuration} parameter} string group
20126 Group of the user who will run the ddclient program.
20128 Defaults to @samp{"ddclient"}.
20132 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
20133 Secret file which will be appended to @file{ddclient.conf} file. This
20134 file contains credentials for use by ddclient. You are expected to
20135 create it manually.
20137 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
20141 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
20142 Extra options will be appended to @file{ddclient.conf} file.
20144 Defaults to @samp{()}.
20149 @c %end of fragment
20153 @subsection VPN Services
20154 @cindex VPN (virtual private network)
20155 @cindex virtual private network (VPN)
20157 The @code{(gnu services vpn)} module provides services related to
20158 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
20159 your machine to connect to a VPN, and a @emph{server} service for your machine
20160 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
20162 @deffn {Scheme Procedure} openvpn-client-service @
20163 [#:config (openvpn-client-configuration)]
20165 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
20168 @deffn {Scheme Procedure} openvpn-server-service @
20169 [#:config (openvpn-server-configuration)]
20171 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
20173 Both can be run simultaneously.
20176 @c %automatically generated documentation
20178 Available @code{openvpn-client-configuration} fields are:
20180 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
20181 The OpenVPN package.
20185 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
20186 The OpenVPN pid file.
20188 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
20192 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
20193 The protocol (UDP or TCP) used to open a channel between clients and
20196 Defaults to @samp{udp}.
20200 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
20201 The device type used to represent the VPN connection.
20203 Defaults to @samp{tun}.
20207 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
20208 The certificate authority to check connections against.
20210 Defaults to @samp{"/etc/openvpn/ca.crt"}.
20214 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
20215 The certificate of the machine the daemon is running on. It should be
20216 signed by the authority given in @code{ca}.
20218 Defaults to @samp{"/etc/openvpn/client.crt"}.
20222 @deftypevr {@code{openvpn-client-configuration} parameter} string key
20223 The key of the machine the daemon is running on. It must be the key whose
20224 certificate is @code{cert}.
20226 Defaults to @samp{"/etc/openvpn/client.key"}.
20230 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
20231 Whether to use the lzo compression algorithm.
20233 Defaults to @samp{#t}.
20237 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
20238 Don't re-read key files across SIGUSR1 or --ping-restart.
20240 Defaults to @samp{#t}.
20244 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
20245 Don't close and reopen TUN/TAP device or run up/down scripts across
20246 SIGUSR1 or --ping-restart restarts.
20248 Defaults to @samp{#t}.
20252 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
20255 Defaults to @samp{3}.
20259 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
20260 Add an additional layer of HMAC authentication on top of the TLS control
20261 channel to protect against DoS attacks.
20263 Defaults to @samp{#f}.
20267 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
20268 Whether to check the server certificate has server usage extension.
20270 Defaults to @samp{#t}.
20274 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
20275 Bind to a specific local port number.
20277 Defaults to @samp{#f}.
20281 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
20282 Retry resolving server address.
20284 Defaults to @samp{#t}.
20288 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
20289 A list of remote servers to connect to.
20291 Defaults to @samp{()}.
20293 Available @code{openvpn-remote-configuration} fields are:
20295 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
20298 Defaults to @samp{"my-server"}.
20302 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
20303 Port number the server listens to.
20305 Defaults to @samp{1194}.
20310 @c %end of automatic openvpn-client documentation
20312 @c %automatically generated documentation
20314 Available @code{openvpn-server-configuration} fields are:
20316 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
20317 The OpenVPN package.
20321 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
20322 The OpenVPN pid file.
20324 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
20328 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
20329 The protocol (UDP or TCP) used to open a channel between clients and
20332 Defaults to @samp{udp}.
20336 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
20337 The device type used to represent the VPN connection.
20339 Defaults to @samp{tun}.
20343 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
20344 The certificate authority to check connections against.
20346 Defaults to @samp{"/etc/openvpn/ca.crt"}.
20350 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
20351 The certificate of the machine the daemon is running on. It should be
20352 signed by the authority given in @code{ca}.
20354 Defaults to @samp{"/etc/openvpn/client.crt"}.
20358 @deftypevr {@code{openvpn-server-configuration} parameter} string key
20359 The key of the machine the daemon is running on. It must be the key whose
20360 certificate is @code{cert}.
20362 Defaults to @samp{"/etc/openvpn/client.key"}.
20366 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
20367 Whether to use the lzo compression algorithm.
20369 Defaults to @samp{#t}.
20373 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
20374 Don't re-read key files across SIGUSR1 or --ping-restart.
20376 Defaults to @samp{#t}.
20380 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
20381 Don't close and reopen TUN/TAP device or run up/down scripts across
20382 SIGUSR1 or --ping-restart restarts.
20384 Defaults to @samp{#t}.
20388 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
20391 Defaults to @samp{3}.
20395 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
20396 Add an additional layer of HMAC authentication on top of the TLS control
20397 channel to protect against DoS attacks.
20399 Defaults to @samp{#f}.
20403 @deftypevr {@code{openvpn-server-configuration} parameter} number port
20404 Specifies the port number on which the server listens.
20406 Defaults to @samp{1194}.
20410 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
20411 An ip and mask specifying the subnet inside the virtual network.
20413 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
20417 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
20418 A CIDR notation specifying the IPv6 subnet inside the virtual network.
20420 Defaults to @samp{#f}.
20424 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
20425 The Diffie-Hellman parameters file.
20427 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
20431 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
20432 The file that records client IPs.
20434 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
20438 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
20439 When true, the server will act as a gateway for its clients.
20441 Defaults to @samp{#f}.
20445 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
20446 When true, clients are allowed to talk to each other inside the VPN.
20448 Defaults to @samp{#f}.
20452 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
20453 Causes ping-like messages to be sent back and forth over the link so
20454 that each side knows when the other side has gone down. @code{keepalive}
20455 requires a pair. The first element is the period of the ping sending,
20456 and the second element is the timeout before considering the other side
20461 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
20462 The maximum number of clients.
20464 Defaults to @samp{100}.
20468 @deftypevr {@code{openvpn-server-configuration} parameter} string status
20469 The status file. This file shows a small report on current connection.
20470 It is truncated and rewritten every minute.
20472 Defaults to @samp{"/var/run/openvpn/status"}.
20476 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
20477 The list of configuration for some clients.
20479 Defaults to @samp{()}.
20481 Available @code{openvpn-ccd-configuration} fields are:
20483 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
20486 Defaults to @samp{"client"}.
20490 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
20493 Defaults to @samp{#f}.
20497 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
20500 Defaults to @samp{#f}.
20507 @c %end of automatic openvpn-server documentation
20510 @node Network File System
20511 @subsection Network File System
20514 The @code{(gnu services nfs)} module provides the following services,
20515 which are most commonly used in relation to mounting or exporting
20516 directory trees as @dfn{network file systems} (NFS).
20518 @subsubheading RPC Bind Service
20521 The RPC Bind service provides a facility to map program numbers into
20522 universal addresses.
20523 Many NFS related services use this facility. Hence it is automatically
20524 started when a dependent service starts.
20526 @defvr {Scheme Variable} rpcbind-service-type
20527 A service type for the RPC portmapper daemon.
20531 @deftp {Data Type} rpcbind-configuration
20532 Data type representing the configuration of the RPC Bind Service.
20533 This type has the following parameters:
20535 @item @code{rpcbind} (default: @code{rpcbind})
20536 The rpcbind package to use.
20538 @item @code{warm-start?} (default: @code{#t})
20539 If this parameter is @code{#t}, then the daemon will read a
20540 state file on startup thus reloading state information saved by a previous
20546 @subsubheading Pipefs Pseudo File System
20550 The pipefs file system is used to transfer NFS related data
20551 between the kernel and user space programs.
20553 @defvr {Scheme Variable} pipefs-service-type
20554 A service type for the pipefs pseudo file system.
20557 @deftp {Data Type} pipefs-configuration
20558 Data type representing the configuration of the pipefs pseudo file system service.
20559 This type has the following parameters:
20561 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20562 The directory to which the file system is to be attached.
20567 @subsubheading GSS Daemon Service
20570 @cindex global security system
20572 The @dfn{global security system} (GSS) daemon provides strong security for RPC
20574 Before exchanging RPC requests an RPC client must establish a security
20575 context. Typically this is done using the Kerberos command @command{kinit}
20576 or automatically at login time using PAM services (@pxref{Kerberos Services}).
20578 @defvr {Scheme Variable} gss-service-type
20579 A service type for the Global Security System (GSS) daemon.
20582 @deftp {Data Type} gss-configuration
20583 Data type representing the configuration of the GSS daemon service.
20584 This type has the following parameters:
20586 @item @code{nfs-utils} (default: @code{nfs-utils})
20587 The package in which the @command{rpc.gssd} command is to be found.
20589 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20590 The directory where the pipefs file system is mounted.
20596 @subsubheading IDMAP Daemon Service
20598 @cindex name mapper
20600 The idmap daemon service provides mapping between user IDs and user names.
20601 Typically it is required in order to access file systems mounted via NFSv4.
20603 @defvr {Scheme Variable} idmap-service-type
20604 A service type for the Identity Mapper (IDMAP) daemon.
20607 @deftp {Data Type} idmap-configuration
20608 Data type representing the configuration of the IDMAP daemon service.
20609 This type has the following parameters:
20611 @item @code{nfs-utils} (default: @code{nfs-utils})
20612 The package in which the @command{rpc.idmapd} command is to be found.
20614 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20615 The directory where the pipefs file system is mounted.
20617 @item @code{domain} (default: @code{#f})
20618 The local NFSv4 domain name.
20619 This must be a string or @code{#f}.
20620 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
20625 @node Continuous Integration
20626 @subsection Continuous Integration
20628 @cindex continuous integration
20629 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
20630 continuous integration tool for Guix. It can be used both for development and
20631 for providing substitutes to others (@pxref{Substitutes}).
20633 The @code{(gnu services cuirass)} module provides the following service.
20635 @defvr {Scheme Procedure} cuirass-service-type
20636 The type of the Cuirass service. Its value must be a
20637 @code{cuirass-configuration} object, as described below.
20640 To add build jobs, you have to set the @code{specifications} field of the
20641 configuration. Here is an example of a service that polls the Guix repository
20642 and builds the packages from a manifest. Some of the packages are defined in
20643 the @code{"custom-packages"} input, which is the equivalent of
20644 @code{GUIX_PACKAGE_PATH}.
20647 (define %cuirass-specs
20649 '((#:name . "my-manifest")
20650 (#:load-path-inputs . ("guix"))
20651 (#:package-path-inputs . ("custom-packages"))
20652 (#:proc-input . "guix")
20653 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
20654 (#:proc . cuirass-jobs)
20655 (#:proc-args . ((subset . "manifests")
20656 (systems . ("x86_64-linux"))
20657 (manifests . (("config" . "guix/manifest.scm")))))
20658 (#:inputs . (((#:name . "guix")
20659 (#:url . "git://git.savannah.gnu.org/guix.git")
20660 (#:load-path . ".")
20661 (#:branch . "master")
20662 (#:no-compile? . #t))
20663 ((#:name . "config")
20664 (#:url . "git://git.example.org/config.git")
20665 (#:load-path . ".")
20666 (#:branch . "master")
20667 (#:no-compile? . #t))
20668 ((#:name . "custom-packages")
20669 (#:url . "git://git.example.org/custom-packages.git")
20670 (#:load-path . ".")
20671 (#:branch . "master")
20672 (#:no-compile? . #t)))))))
20674 (service cuirass-service-type
20675 (cuirass-configuration
20676 (specifications %cuirass-specs)))
20679 While information related to build jobs is located directly in the
20680 specifications, global settings for the @command{cuirass} process are
20681 accessible in other @code{cuirass-configuration} fields.
20683 @deftp {Data Type} cuirass-configuration
20684 Data type representing the configuration of Cuirass.
20687 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
20688 Location of the log file.
20690 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
20691 Location of the repository cache.
20693 @item @code{user} (default: @code{"cuirass"})
20694 Owner of the @code{cuirass} process.
20696 @item @code{group} (default: @code{"cuirass"})
20697 Owner's group of the @code{cuirass} process.
20699 @item @code{interval} (default: @code{60})
20700 Number of seconds between the poll of the repositories followed by the
20703 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
20704 Location of sqlite database which contains the build results and previously
20705 added specifications.
20707 @item @code{ttl} (default: @code{(* 30 24 3600)})
20708 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
20709 are registered for build results. This means that build results are protected
20710 from garbage collection for at least @var{ttl} seconds.
20712 @item @code{port} (default: @code{8081})
20713 Port number used by the HTTP server.
20715 @item --listen=@var{host}
20716 Listen on the network interface for @var{host}. The default is to
20717 accept connections from localhost.
20719 @item @code{specifications} (default: @code{#~'()})
20720 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
20721 where a specification is an association list
20722 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
20723 keys are keywords (@code{#:keyword-example}) as shown in the example
20726 @item @code{use-substitutes?} (default: @code{#f})
20727 This allows using substitutes to avoid building every dependencies of a job
20730 @item @code{one-shot?} (default: @code{#f})
20731 Only evaluate specifications and build derivations once.
20733 @item @code{fallback?} (default: @code{#f})
20734 When substituting a pre-built binary fails, fall back to building
20737 @item @code{cuirass} (default: @code{cuirass})
20738 The Cuirass package to use.
20742 @node Power Management Services
20743 @subsection Power Management Services
20746 @cindex power management with TLP
20747 @subsubheading TLP daemon
20749 The @code{(gnu services pm)} module provides a Guix service definition
20750 for the Linux power management tool TLP.
20752 TLP enables various powersaving modes in userspace and kernel.
20753 Contrary to @code{upower-service}, it is not a passive,
20754 monitoring tool, as it will apply custom settings each time a new power
20755 source is detected. More information can be found at
20756 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
20758 @deffn {Scheme Variable} tlp-service-type
20759 The service type for the TLP tool. Its value should be a valid
20760 TLP configuration (see below). To use the default settings, simply
20763 (service tlp-service-type)
20767 By default TLP does not need much configuration but most TLP parameters
20768 can be tweaked using @code{tlp-configuration}.
20770 Each parameter definition is preceded by its type; for example,
20771 @samp{boolean foo} indicates that the @code{foo} parameter
20772 should be specified as a boolean. Types starting with
20773 @code{maybe-} denote parameters that won't show up in TLP config file
20774 when their value is @code{'disabled}.
20776 @c The following documentation was initially generated by
20777 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
20778 @c documentation is better, so we shouldn't hesitate to edit below as
20779 @c needed. However if the change you want to make to this documentation
20780 @c can be done in an automated way, it's probably easier to change
20781 @c (generate-documentation) than to make it below and have to deal with
20782 @c the churn as TLP updates.
20784 Available @code{tlp-configuration} fields are:
20786 @deftypevr {@code{tlp-configuration} parameter} package tlp
20791 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
20792 Set to true if you wish to enable TLP.
20794 Defaults to @samp{#t}.
20798 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
20799 Default mode when no power supply can be detected. Alternatives are AC
20802 Defaults to @samp{"AC"}.
20806 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
20807 Number of seconds Linux kernel has to wait after the disk goes idle,
20808 before syncing on AC.
20810 Defaults to @samp{0}.
20814 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
20815 Same as @code{disk-idle-ac} but on BAT mode.
20817 Defaults to @samp{2}.
20821 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
20822 Dirty pages flushing periodicity, expressed in seconds.
20824 Defaults to @samp{15}.
20828 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
20829 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
20831 Defaults to @samp{60}.
20835 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
20836 CPU frequency scaling governor on AC mode. With intel_pstate driver,
20837 alternatives are powersave and performance. With acpi-cpufreq driver,
20838 alternatives are ondemand, powersave, performance and conservative.
20840 Defaults to @samp{disabled}.
20844 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
20845 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
20847 Defaults to @samp{disabled}.
20851 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
20852 Set the min available frequency for the scaling governor on AC.
20854 Defaults to @samp{disabled}.
20858 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
20859 Set the max available frequency for the scaling governor on AC.
20861 Defaults to @samp{disabled}.
20865 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
20866 Set the min available frequency for the scaling governor on BAT.
20868 Defaults to @samp{disabled}.
20872 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
20873 Set the max available frequency for the scaling governor on BAT.
20875 Defaults to @samp{disabled}.
20879 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
20880 Limit the min P-state to control the power dissipation of the CPU, in AC
20881 mode. Values are stated as a percentage of the available performance.
20883 Defaults to @samp{disabled}.
20887 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
20888 Limit the max P-state to control the power dissipation of the CPU, in AC
20889 mode. Values are stated as a percentage of the available performance.
20891 Defaults to @samp{disabled}.
20895 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
20896 Same as @code{cpu-min-perf-on-ac} on BAT mode.
20898 Defaults to @samp{disabled}.
20902 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
20903 Same as @code{cpu-max-perf-on-ac} on BAT mode.
20905 Defaults to @samp{disabled}.
20909 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
20910 Enable CPU turbo boost feature on AC mode.
20912 Defaults to @samp{disabled}.
20916 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
20917 Same as @code{cpu-boost-on-ac?} on BAT mode.
20919 Defaults to @samp{disabled}.
20923 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
20924 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
20925 used under light load conditions.
20927 Defaults to @samp{#f}.
20931 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
20932 Same as @code{sched-powersave-on-ac?} but on BAT mode.
20934 Defaults to @samp{#t}.
20938 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
20939 Enable Linux kernel NMI watchdog.
20941 Defaults to @samp{#f}.
20945 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
20946 For Linux kernels with PHC patch applied, change CPU voltages. An
20947 example value would be @samp{"F:V F:V F:V F:V"}.
20949 Defaults to @samp{disabled}.
20953 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
20954 Set CPU performance versus energy saving policy on AC. Alternatives are
20955 performance, normal, powersave.
20957 Defaults to @samp{"performance"}.
20961 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
20962 Same as @code{energy-perf-policy-ac} but on BAT mode.
20964 Defaults to @samp{"powersave"}.
20968 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
20973 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
20974 Hard disk advanced power management level.
20978 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
20979 Same as @code{disk-apm-bat} but on BAT mode.
20983 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
20984 Hard disk spin down timeout. One value has to be specified for each
20985 declared hard disk.
20987 Defaults to @samp{disabled}.
20991 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
20992 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
20994 Defaults to @samp{disabled}.
20998 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
20999 Select IO scheduler for disk devices. One value has to be specified for
21000 each declared hard disk. Example alternatives are cfq, deadline and
21003 Defaults to @samp{disabled}.
21007 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
21008 SATA aggressive link power management (ALPM) level. Alternatives are
21009 min_power, medium_power, max_performance.
21011 Defaults to @samp{"max_performance"}.
21015 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
21016 Same as @code{sata-linkpwr-ac} but on BAT mode.
21018 Defaults to @samp{"min_power"}.
21022 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
21023 Exclude specified SATA host devices for link power management.
21025 Defaults to @samp{disabled}.
21029 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
21030 Enable Runtime Power Management for AHCI controller and disks on AC
21033 Defaults to @samp{disabled}.
21037 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
21038 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
21040 Defaults to @samp{disabled}.
21044 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
21045 Seconds of inactivity before disk is suspended.
21047 Defaults to @samp{15}.
21051 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
21052 PCI Express Active State Power Management level. Alternatives are
21053 default, performance, powersave.
21055 Defaults to @samp{"performance"}.
21059 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
21060 Same as @code{pcie-aspm-ac} but on BAT mode.
21062 Defaults to @samp{"powersave"}.
21066 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
21067 Radeon graphics clock speed level. Alternatives are low, mid, high,
21070 Defaults to @samp{"high"}.
21074 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
21075 Same as @code{radeon-power-ac} but on BAT mode.
21077 Defaults to @samp{"low"}.
21081 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
21082 Radeon dynamic power management method (DPM). Alternatives are battery,
21085 Defaults to @samp{"performance"}.
21089 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
21090 Same as @code{radeon-dpm-state-ac} but on BAT mode.
21092 Defaults to @samp{"battery"}.
21096 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
21097 Radeon DPM performance level. Alternatives are auto, low, high.
21099 Defaults to @samp{"auto"}.
21103 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
21104 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
21106 Defaults to @samp{"auto"}.
21110 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
21111 Wifi power saving mode.
21113 Defaults to @samp{#f}.
21117 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
21118 Same as @code{wifi-power-ac?} but on BAT mode.
21120 Defaults to @samp{#t}.
21124 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
21125 Disable wake on LAN.
21127 Defaults to @samp{#t}.
21131 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
21132 Timeout duration in seconds before activating audio power saving on
21133 Intel HDA and AC97 devices. A value of 0 disables power saving.
21135 Defaults to @samp{0}.
21139 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
21140 Same as @code{sound-powersave-ac} but on BAT mode.
21142 Defaults to @samp{1}.
21146 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
21147 Disable controller in powersaving mode on Intel HDA devices.
21149 Defaults to @samp{#t}.
21153 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
21154 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
21155 powered on again by releasing (and reinserting) the eject lever or by
21156 pressing the disc eject button on newer models.
21158 Defaults to @samp{#f}.
21162 @deftypevr {@code{tlp-configuration} parameter} string bay-device
21163 Name of the optical drive device to power off.
21165 Defaults to @samp{"sr0"}.
21169 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
21170 Runtime Power Management for PCI(e) bus devices. Alternatives are on
21173 Defaults to @samp{"on"}.
21177 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
21178 Same as @code{runtime-pm-ac} but on BAT mode.
21180 Defaults to @samp{"auto"}.
21184 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
21185 Runtime Power Management for all PCI(e) bus devices, except blacklisted
21188 Defaults to @samp{#t}.
21192 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
21193 Exclude specified PCI(e) device addresses from Runtime Power Management.
21195 Defaults to @samp{disabled}.
21199 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
21200 Exclude PCI(e) devices assigned to the specified drivers from Runtime
21205 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
21206 Enable USB autosuspend feature.
21208 Defaults to @samp{#t}.
21212 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
21213 Exclude specified devices from USB autosuspend.
21215 Defaults to @samp{disabled}.
21219 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
21220 Exclude WWAN devices from USB autosuspend.
21222 Defaults to @samp{#t}.
21226 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
21227 Include specified devices into USB autosuspend, even if they are already
21228 excluded by the driver or via @code{usb-blacklist-wwan?}.
21230 Defaults to @samp{disabled}.
21234 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
21235 Enable USB autosuspend before shutdown.
21237 Defaults to @samp{disabled}.
21241 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
21242 Restore radio device state (bluetooth, wifi, wwan) from previous
21243 shutdown on system startup.
21245 Defaults to @samp{#f}.
21250 @cindex CPU frequency scaling with thermald
21251 @subsubheading Thermald daemon
21253 The @code{(gnu services pm)} module provides an interface to
21254 thermald, a CPU frequency scaling service which helps prevent overheating.
21256 @defvr {Scheme Variable} thermald-service-type
21257 This is the service type for
21258 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
21259 Thermal Daemon, which is responsible for controlling the thermal state
21260 of processors and preventing overheating.
21263 @deftp {Data Type} thermald-configuration
21264 Data type representing the configuration of @code{thermald-service-type}.
21267 @item @code{ignore-cpuid-check?} (default: @code{#f})
21268 Ignore cpuid check for supported CPU models.
21270 @item @code{thermald} (default: @var{thermald})
21271 Package object of thermald.
21276 @node Audio Services
21277 @subsection Audio Services
21279 The @code{(gnu services audio)} module provides a service to start MPD
21280 (the Music Player Daemon).
21283 @subsubheading Music Player Daemon
21285 The Music Player Daemon (MPD) is a service that can play music while
21286 being controlled from the local machine or over the network by a variety
21289 The following example shows how one might run @code{mpd} as user
21290 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
21293 (service mpd-service-type
21299 @defvr {Scheme Variable} mpd-service-type
21300 The service type for @command{mpd}
21303 @deftp {Data Type} mpd-configuration
21304 Data type representing the configuration of @command{mpd}.
21307 @item @code{user} (default: @code{"mpd"})
21308 The user to run mpd as.
21310 @item @code{music-dir} (default: @code{"~/Music"})
21311 The directory to scan for music files.
21313 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
21314 The directory to store playlists.
21316 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
21317 The location of the music database.
21319 @item @code{state-file} (default: @code{"~/.mpd/state"})
21320 The location of the file that stores current MPD's state.
21322 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
21323 The location of the sticker database.
21325 @item @code{port} (default: @code{"6600"})
21326 The port to run mpd on.
21328 @item @code{address} (default: @code{"any"})
21329 The address that mpd will bind to. To use a Unix domain socket,
21330 an absolute path can be specified here.
21335 @node Virtualization Services
21336 @subsection Virtualization services
21338 The @code{(gnu services virtualization)} module provides services for
21339 the libvirt and virtlog daemons, as well as other virtualization-related
21342 @subsubheading Libvirt daemon
21343 @code{libvirtd} is the server side daemon component of the libvirt
21344 virtualization management system. This daemon runs on host servers
21345 and performs required management tasks for virtualized guests.
21347 @deffn {Scheme Variable} libvirt-service-type
21348 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
21349 Its value must be a @code{libvirt-configuration}.
21352 (service libvirt-service-type
21353 (libvirt-configuration
21354 (unix-sock-group "libvirt")
21355 (tls-port "16555")))
21359 @c Auto-generated with (generate-libvirt-documentation)
21360 Available @code{libvirt-configuration} fields are:
21362 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
21367 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
21368 Flag listening for secure TLS connections on the public TCP/IP port.
21369 must set @code{listen} for this to have any effect.
21371 It is necessary to setup a CA and issue server certificates before using
21374 Defaults to @samp{#t}.
21378 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
21379 Listen for unencrypted TCP connections on the public TCP/IP port. must
21380 set @code{listen} for this to have any effect.
21382 Using the TCP socket requires SASL authentication by default. Only SASL
21383 mechanisms which support data encryption are allowed. This is
21384 DIGEST_MD5 and GSSAPI (Kerberos5)
21386 Defaults to @samp{#f}.
21390 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
21391 Port for accepting secure TLS connections This can be a port number, or
21394 Defaults to @samp{"16514"}.
21398 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
21399 Port for accepting insecure TCP connections This can be a port number,
21402 Defaults to @samp{"16509"}.
21406 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
21407 IP address or hostname used for client connections.
21409 Defaults to @samp{"0.0.0.0"}.
21413 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
21414 Flag toggling mDNS advertisement of the libvirt service.
21416 Alternatively can disable for all services on a host by stopping the
21419 Defaults to @samp{#f}.
21423 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
21424 Default mDNS advertisement name. This must be unique on the immediate
21427 Defaults to @samp{"Virtualization Host <hostname>"}.
21431 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
21432 UNIX domain socket group ownership. This can be used to allow a
21433 'trusted' set of users access to management capabilities without
21436 Defaults to @samp{"root"}.
21440 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
21441 UNIX socket permissions for the R/O socket. This is used for monitoring
21444 Defaults to @samp{"0777"}.
21448 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
21449 UNIX socket permissions for the R/W socket. Default allows only root.
21450 If PolicyKit is enabled on the socket, the default will change to allow
21451 everyone (eg, 0777)
21453 Defaults to @samp{"0770"}.
21457 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
21458 UNIX socket permissions for the admin socket. Default allows only owner
21459 (root), do not change it unless you are sure to whom you are exposing
21462 Defaults to @samp{"0777"}.
21466 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
21467 The directory in which sockets will be found/created.
21469 Defaults to @samp{"/var/run/libvirt"}.
21473 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
21474 Authentication scheme for UNIX read-only sockets. By default socket
21475 permissions allow anyone to connect
21477 Defaults to @samp{"polkit"}.
21481 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
21482 Authentication scheme for UNIX read-write sockets. By default socket
21483 permissions only allow root. If PolicyKit support was compiled into
21484 libvirt, the default will be to use 'polkit' auth.
21486 Defaults to @samp{"polkit"}.
21490 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
21491 Authentication scheme for TCP sockets. If you don't enable SASL, then
21492 all TCP traffic is cleartext. Don't do this outside of a dev/test
21495 Defaults to @samp{"sasl"}.
21499 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
21500 Authentication scheme for TLS sockets. TLS sockets already have
21501 encryption provided by the TLS layer, and limited authentication is done
21504 It is possible to make use of any SASL authentication mechanism as well,
21505 by using 'sasl' for this option
21507 Defaults to @samp{"none"}.
21511 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
21512 API access control scheme.
21514 By default an authenticated user is allowed access to all APIs. Access
21515 drivers can place restrictions on this.
21517 Defaults to @samp{()}.
21521 @deftypevr {@code{libvirt-configuration} parameter} string key-file
21522 Server key file path. If set to an empty string, then no private key is
21525 Defaults to @samp{""}.
21529 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
21530 Server key file path. If set to an empty string, then no certificate is
21533 Defaults to @samp{""}.
21537 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
21538 Server key file path. If set to an empty string, then no CA certificate
21541 Defaults to @samp{""}.
21545 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
21546 Certificate revocation list path. If set to an empty string, then no
21549 Defaults to @samp{""}.
21553 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
21554 Disable verification of our own server certificates.
21556 When libvirtd starts it performs some sanity checks against its own
21559 Defaults to @samp{#f}.
21563 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
21564 Disable verification of client certificates.
21566 Client certificate verification is the primary authentication mechanism.
21567 Any client which does not present a certificate signed by the CA will be
21570 Defaults to @samp{#f}.
21574 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
21575 Whitelist of allowed x509 Distinguished Name.
21577 Defaults to @samp{()}.
21581 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
21582 Whitelist of allowed SASL usernames. The format for username depends on
21583 the SASL authentication mechanism.
21585 Defaults to @samp{()}.
21589 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
21590 Override the compile time default TLS priority string. The default is
21591 usually "NORMAL" unless overridden at build time. Only set this is it
21592 is desired for libvirt to deviate from the global default settings.
21594 Defaults to @samp{"NORMAL"}.
21598 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
21599 Maximum number of concurrent client connections to allow over all
21602 Defaults to @samp{5000}.
21606 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
21607 Maximum length of queue of connections waiting to be accepted by the
21608 daemon. Note, that some protocols supporting retransmission may obey
21609 this so that a later reattempt at connection succeeds.
21611 Defaults to @samp{1000}.
21615 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
21616 Maximum length of queue of accepted but not yet authenticated clients.
21617 Set this to zero to turn this feature off
21619 Defaults to @samp{20}.
21623 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
21624 Number of workers to start up initially.
21626 Defaults to @samp{5}.
21630 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
21631 Maximum number of worker threads.
21633 If the number of active clients exceeds @code{min-workers}, then more
21634 threads are spawned, up to max_workers limit. Typically you'd want
21635 max_workers to equal maximum number of clients allowed.
21637 Defaults to @samp{20}.
21641 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
21642 Number of priority workers. If all workers from above pool are stuck,
21643 some calls marked as high priority (notably domainDestroy) can be
21644 executed in this pool.
21646 Defaults to @samp{5}.
21650 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
21651 Total global limit on concurrent RPC calls.
21653 Defaults to @samp{20}.
21657 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
21658 Limit on concurrent requests from a single client connection. To avoid
21659 one client monopolizing the server this should be a small fraction of
21660 the global max_requests and max_workers parameter.
21662 Defaults to @samp{5}.
21666 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
21667 Same as @code{min-workers} but for the admin interface.
21669 Defaults to @samp{1}.
21673 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
21674 Same as @code{max-workers} but for the admin interface.
21676 Defaults to @samp{5}.
21680 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
21681 Same as @code{max-clients} but for the admin interface.
21683 Defaults to @samp{5}.
21687 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
21688 Same as @code{max-queued-clients} but for the admin interface.
21690 Defaults to @samp{5}.
21694 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
21695 Same as @code{max-client-requests} but for the admin interface.
21697 Defaults to @samp{5}.
21701 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
21702 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
21704 Defaults to @samp{3}.
21708 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
21711 A filter allows to select a different logging level for a given category
21712 of logs The format for a filter is one of:
21723 where @code{name} is a string which is matched against the category
21724 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
21725 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
21726 be a substring of the full category name, in order to match multiple
21727 similar categories), the optional "+" prefix tells libvirt to log stack
21728 trace for each message matching name, and @code{x} is the minimal level
21729 where matching messages should be logged:
21746 Multiple filters can be defined in a single filters statement, they just
21747 need to be separated by spaces.
21749 Defaults to @samp{"3:remote 4:event"}.
21753 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
21756 An output is one of the places to save logging information. The format
21757 for an output can be:
21761 output goes to stderr
21763 @item x:syslog:name
21764 use syslog for the output and use the given name as the ident
21766 @item x:file:file_path
21767 output to a file, with the given filepath
21770 output to journald logging system
21774 In all case the x prefix is the minimal level, acting as a filter
21791 Multiple outputs can be defined, they just need to be separated by
21794 Defaults to @samp{"3:stderr"}.
21798 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
21799 Allows usage of the auditing subsystem to be altered
21803 0: disable all auditing
21806 1: enable auditing, only if enabled on host
21809 2: enable auditing, and exit if disabled on host.
21813 Defaults to @samp{1}.
21817 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
21818 Send audit messages via libvirt logging infrastructure.
21820 Defaults to @samp{#f}.
21824 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
21825 Host UUID. UUID must not have all digits be the same.
21827 Defaults to @samp{""}.
21831 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
21832 Source to read host UUID.
21836 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
21839 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
21843 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
21846 Defaults to @samp{"smbios"}.
21850 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
21851 A keepalive message is sent to a client after @code{keepalive_interval}
21852 seconds of inactivity to check if the client is still responding. If
21853 set to -1, libvirtd will never send keepalive requests; however clients
21854 can still send them and the daemon will send responses.
21856 Defaults to @samp{5}.
21860 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
21861 Maximum number of keepalive messages that are allowed to be sent to the
21862 client without getting any response before the connection is considered
21865 In other words, the connection is automatically closed approximately
21866 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
21867 the last message received from the client. When @code{keepalive-count}
21868 is set to 0, connections will be automatically closed after
21869 @code{keepalive-interval} seconds of inactivity without sending any
21870 keepalive messages.
21872 Defaults to @samp{5}.
21876 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
21877 Same as above but for admin interface.
21879 Defaults to @samp{5}.
21883 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
21884 Same as above but for admin interface.
21886 Defaults to @samp{5}.
21890 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
21891 Timeout for Open vSwitch calls.
21893 The @code{ovs-vsctl} utility is used for the configuration and its
21894 timeout option is set by default to 5 seconds to avoid potential
21895 infinite waits blocking libvirt.
21897 Defaults to @samp{5}.
21901 @c %end of autogenerated docs
21903 @subsubheading Virtlog daemon
21904 The virtlogd service is a server side daemon component of libvirt that is
21905 used to manage logs from virtual machine consoles.
21907 This daemon is not used directly by libvirt client applications, rather it
21908 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
21909 standalone daemon, the main @code{libvirtd} daemon can be restarted without
21910 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
21911 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
21913 @deffn {Scheme Variable} virtlog-service-type
21914 This is the type of the virtlog daemon.
21915 Its value must be a @code{virtlog-configuration}.
21918 (service virtlog-service-type
21919 (virtlog-configuration
21920 (max-clients 1000)))
21924 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
21925 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
21927 Defaults to @samp{3}.
21931 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
21934 A filter allows to select a different logging level for a given category
21935 of logs The format for a filter is one of:
21946 where @code{name} is a string which is matched against the category
21947 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
21948 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
21949 be a substring of the full category name, in order to match multiple
21950 similar categories), the optional "+" prefix tells libvirt to log stack
21951 trace for each message matching name, and @code{x} is the minimal level
21952 where matching messages should be logged:
21969 Multiple filters can be defined in a single filters statement, they just
21970 need to be separated by spaces.
21972 Defaults to @samp{"3:remote 4:event"}.
21976 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
21979 An output is one of the places to save logging information The format
21980 for an output can be:
21984 output goes to stderr
21986 @item x:syslog:name
21987 use syslog for the output and use the given name as the ident
21989 @item x:file:file_path
21990 output to a file, with the given filepath
21993 output to journald logging system
21997 In all case the x prefix is the minimal level, acting as a filter
22014 Multiple outputs can be defined, they just need to be separated by
22017 Defaults to @samp{"3:stderr"}.
22021 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
22022 Maximum number of concurrent client connections to allow over all
22025 Defaults to @samp{1024}.
22029 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
22030 Maximum file size before rolling over.
22032 Defaults to @samp{2MB}
22036 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
22037 Maximum number of backup files to keep.
22039 Defaults to @samp{3}
22043 @subsubheading Transparent Emulation with QEMU
22046 @cindex @code{binfmt_misc}
22047 @code{qemu-binfmt-service-type} provides support for transparent
22048 emulation of program binaries built for different architectures---e.g.,
22049 it allows you to transparently execute an ARMv7 program on an x86_64
22050 machine. It achieves this by combining the @uref{https://www.qemu.org,
22051 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
22053 @defvr {Scheme Variable} qemu-binfmt-service-type
22054 This is the type of the QEMU/binfmt service for transparent emulation.
22055 Its value must be a @code{qemu-binfmt-configuration} object, which
22056 specifies the QEMU package to use as well as the architecture we want to
22060 (service qemu-binfmt-service-type
22061 (qemu-binfmt-configuration
22062 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
22065 In this example, we enable transparent emulation for the ARM and aarch64
22066 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
22067 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
22068 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
22071 @deftp {Data Type} qemu-binfmt-configuration
22072 This is the configuration for the @code{qemu-binfmt} service.
22075 @item @code{platforms} (default: @code{'()})
22076 The list of emulated QEMU platforms. Each item must be a @dfn{platform
22077 object} as returned by @code{lookup-qemu-platforms} (see below).
22079 @item @code{guix-support?} (default: @code{#f})
22080 When it is true, QEMU and all its dependencies are added to the build
22081 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
22082 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
22083 handlers to be used within the build environment, which in turn means
22084 that you can transparently build programs for another architecture.
22086 For example, let's suppose you're on an x86_64 machine and you have this
22090 (service qemu-binfmt-service-type
22091 (qemu-binfmt-configuration
22092 (platforms (lookup-qemu-platforms "arm"))
22093 (guix-support? #t)))
22099 guix build -s armhf-linux inkscape
22103 and it will build Inkscape for ARMv7 @emph{as if it were a native
22104 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
22105 if you'd like to test a package build for an architecture you don't have
22108 @item @code{qemu} (default: @code{qemu})
22109 The QEMU package to use.
22113 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
22114 Return the list of QEMU platform objects corresponding to
22115 @var{platforms}@dots{}. @var{platforms} must be a list of strings
22116 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
22117 @code{"mips64el"}, and so on.
22120 @deffn {Scheme Procedure} qemu-platform? @var{obj}
22121 Return true if @var{obj} is a platform object.
22124 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
22125 Return the name of @var{platform}---a string such as @code{"arm"}.
22128 @node Version Control Services
22129 @subsection Version Control Services
22131 The @code{(gnu services version-control)} module provides a service to
22132 allow remote access to local Git repositories. There are three options:
22133 the @code{git-daemon-service}, which provides access to repositories via
22134 the @code{git://} unsecured TCP-based protocol, extending the
22135 @code{nginx} web server to proxy some requests to
22136 @code{git-http-backend}, or providing a web interface with
22137 @code{cgit-service-type}.
22139 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
22141 Return a service that runs @command{git daemon}, a simple TCP server to
22142 expose repositories over the Git protocol for anonymous access.
22144 The optional @var{config} argument should be a
22145 @code{<git-daemon-configuration>} object, by default it allows read-only
22146 access to exported@footnote{By creating the magic file
22147 "git-daemon-export-ok" in the repository directory.} repositories under
22152 @deftp {Data Type} git-daemon-configuration
22153 Data type representing the configuration for @code{git-daemon-service}.
22156 @item @code{package} (default: @var{git})
22157 Package object of the Git distributed version control system.
22159 @item @code{export-all?} (default: @var{#f})
22160 Whether to allow access for all Git repositories, even if they do not
22161 have the @file{git-daemon-export-ok} file.
22163 @item @code{base-path} (default: @file{/srv/git})
22164 Whether to remap all the path requests as relative to the given path.
22165 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
22166 then if you later try to pull @code{git://example.com/hello.git}, git
22167 daemon will interpret the path as @code{/srv/git/hello.git}.
22169 @item @code{user-path} (default: @var{#f})
22170 Whether to allow @code{~user} notation to be used in requests. When
22171 specified with empty string, requests to @code{git://host/~alice/foo} is
22172 taken as a request to access @code{foo} repository in the home directory
22173 of user @code{alice}. If @var{(user-path "path")} is specified, the
22174 same request is taken as a request to access @code{path/foo} repository
22175 in the home directory of user @code{alice}.
22177 @item @code{listen} (default: @var{'()})
22178 Whether to listen on specific IP addresses or hostnames, defaults to
22181 @item @code{port} (default: @var{#f})
22182 Whether to listen on an alternative port, which defaults to 9418.
22184 @item @code{whitelist} (default: @var{'()})
22185 If not empty, only allow access to this list of directories.
22187 @item @code{extra-options} (default: @var{'()})
22188 Extra options will be passed to @code{git daemon}, please run
22189 @command{man git-daemon} for more information.
22194 The @code{git://} protocol lacks authentication. When you pull from a
22195 repository fetched via @code{git://}, you don't know that the data you
22196 receive was modified is really coming from the specified host, and you
22197 have your connection is subject to eavesdropping. It's better to use an
22198 authenticated and encrypted transport, such as @code{https}. Although Git allows you
22199 to serve repositories using unsophisticated file-based web servers,
22200 there is a faster protocol implemented by the @code{git-http-backend}
22201 program. This program is the back-end of a proper Git web service. It
22202 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
22203 on running the necessary @code{fcgiwrap} daemon.
22205 Guix has a separate configuration data type for serving Git repositories
22208 @deftp {Data Type} git-http-configuration
22209 Data type representing the configuration for @code{git-http-service}.
22212 @item @code{package} (default: @var{git})
22213 Package object of the Git distributed version control system.
22215 @item @code{git-root} (default: @file{/srv/git})
22216 Directory containing the Git repositories to expose to the world.
22218 @item @code{export-all?} (default: @var{#f})
22219 Whether to expose access for all Git repositories in @var{git-root},
22220 even if they do not have the @file{git-daemon-export-ok} file.
22222 @item @code{uri-path} (default: @file{/git/})
22223 Path prefix for Git access. With the default @code{/git/} prefix, this
22224 will map @code{http://@var{server}/git/@var{repo}.git} to
22225 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
22226 with this prefix are not passed on to this Git instance.
22228 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
22229 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
22234 There is no @code{git-http-service-type}, currently; instead you can
22235 create an @code{nginx-location-configuration} from a
22236 @code{git-http-configuration} and then add that location to a web
22239 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
22240 [config=(git-http-configuration)]
22241 Compute an @code{nginx-location-configuration} that corresponds to the
22242 given Git http configuration. An example nginx service definition to
22243 serve the default @file{/srv/git} over HTTPS might be:
22246 (service nginx-service-type
22247 (nginx-configuration
22250 (nginx-server-configuration
22251 (listen '("443 ssl"))
22252 (server-name "git.my-host.org")
22254 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
22255 (ssl-certificate-key
22256 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
22259 (git-http-nginx-location-configuration
22260 (git-http-configuration (uri-path "/"))))))))))
22263 This example assumes that you are using Let's Encrypt to get your TLS
22264 certificate. @xref{Certificate Services}. The default @code{certbot}
22265 service will redirect all HTTP traffic on @code{git.my-host.org} to
22266 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
22267 system services. @xref{Web Services}.
22270 @subsubheading Cgit Service
22272 @cindex Cgit service
22273 @cindex Git, web interface
22274 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
22275 repositories written in C.
22277 The following example will configure the service with default values.
22278 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
22281 (service cgit-service-type)
22284 The @code{file-object} type designates either a file-like object
22285 (@pxref{G-Expressions, file-like objects}) or a string.
22287 @c %start of fragment
22289 Available @code{cgit-configuration} fields are:
22291 @deftypevr {@code{cgit-configuration} parameter} package package
22296 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
22297 NGINX configuration.
22301 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
22302 Specifies a command which will be invoked to format the content of about
22303 pages (both top-level and for each repository).
22305 Defaults to @samp{""}.
22309 @deftypevr {@code{cgit-configuration} parameter} string agefile
22310 Specifies a path, relative to each repository path, which can be used to
22311 specify the date and time of the youngest commit in the repository.
22313 Defaults to @samp{""}.
22317 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
22318 Specifies a command that will be invoked for authenticating repository
22321 Defaults to @samp{""}.
22325 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
22326 Flag which, when set to @samp{age}, enables date ordering in the branch
22327 ref list, and when set @samp{name} enables ordering by branch name.
22329 Defaults to @samp{"name"}.
22333 @deftypevr {@code{cgit-configuration} parameter} string cache-root
22334 Path used to store the cgit cache entries.
22336 Defaults to @samp{"/var/cache/cgit"}.
22340 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
22341 Number which specifies the time-to-live, in minutes, for the cached
22342 version of repository pages accessed with a fixed SHA1.
22344 Defaults to @samp{-1}.
22348 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
22349 Number which specifies the time-to-live, in minutes, for the cached
22350 version of repository pages accessed without a fixed SHA1.
22352 Defaults to @samp{5}.
22356 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
22357 Number which specifies the time-to-live, in minutes, for the cached
22358 version of the repository summary page.
22360 Defaults to @samp{5}.
22364 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
22365 Number which specifies the time-to-live, in minutes, for the cached
22366 version of the repository index page.
22368 Defaults to @samp{5}.
22372 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
22373 Number which specifies the time-to-live, in minutes, for the result of
22374 scanning a path for Git repositories.
22376 Defaults to @samp{15}.
22380 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
22381 Number which specifies the time-to-live, in minutes, for the cached
22382 version of the repository about page.
22384 Defaults to @samp{15}.
22388 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
22389 Number which specifies the time-to-live, in minutes, for the cached
22390 version of snapshots.
22392 Defaults to @samp{5}.
22396 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
22397 The maximum number of entries in the cgit cache. When set to @samp{0},
22398 caching is disabled.
22400 Defaults to @samp{0}.
22404 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
22405 Sort items in the repo list case sensitively.
22407 Defaults to @samp{#t}.
22411 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
22412 List of common prefixes which, when combined with a repository URL,
22413 generates valid clone URLs for the repository.
22415 Defaults to @samp{()}.
22419 @deftypevr {@code{cgit-configuration} parameter} list clone-url
22420 List of @code{clone-url} templates.
22422 Defaults to @samp{()}.
22426 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
22427 Command which will be invoked to format commit messages.
22429 Defaults to @samp{""}.
22433 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
22434 Flag which, when set to @samp{date}, enables strict date ordering in the
22435 commit log, and when set to @samp{topo} enables strict topological
22438 Defaults to @samp{"git log"}.
22442 @deftypevr {@code{cgit-configuration} parameter} file-object css
22443 URL which specifies the css document to include in all cgit pages.
22445 Defaults to @samp{"/share/cgit/cgit.css"}.
22449 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
22450 Specifies a command which will be invoked to format names and email
22451 address of committers, authors, and taggers, as represented in various
22452 places throughout the cgit interface.
22454 Defaults to @samp{""}.
22458 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
22459 Flag which, when set to @samp{#t}, will make cgit generate a HTML
22460 fragment suitable for embedding in other HTML pages.
22462 Defaults to @samp{#f}.
22466 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
22467 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
22468 commit history graph to the left of the commit messages in the
22469 repository log page.
22471 Defaults to @samp{#f}.
22475 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
22476 Flag which, when set to @samp{#t}, allows all filter settings to be
22477 overridden in repository-specific cgitrc files.
22479 Defaults to @samp{#f}.
22483 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
22484 Flag which, when set to @samp{#t}, allows users to follow a file in the
22487 Defaults to @samp{#f}.
22491 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
22492 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
22495 Defaults to @samp{#t}.
22499 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
22500 Flag which, when set to @samp{#t}, will make cgit generate extra links
22501 "summary", "commit", "tree" for each repo in the repository index.
22503 Defaults to @samp{#f}.
22507 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
22508 Flag which, when set to @samp{#t}, will make cgit display the owner of
22509 each repo in the repository index.
22511 Defaults to @samp{#t}.
22515 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
22516 Flag which, when set to @samp{#t}, will make cgit print the number of
22517 modified files for each commit on the repository log page.
22519 Defaults to @samp{#f}.
22523 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
22524 Flag which, when set to @samp{#t}, will make cgit print the number of
22525 added and removed lines for each commit on the repository log page.
22527 Defaults to @samp{#f}.
22531 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
22532 Flag which, when set to @code{#t}, will make cgit display remote
22533 branches in the summary and refs views.
22535 Defaults to @samp{#f}.
22539 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
22540 Flag which, when set to @code{1}, will make cgit use the subject of the
22541 parent commit as link text when generating links to parent commits in
22544 Defaults to @samp{#f}.
22548 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
22549 Flag which, when set to @samp{#t}, will make cgit use the subject of the
22550 parent commit as link text when generating links to parent commits in
22553 Defaults to @samp{#f}.
22557 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
22558 Flag which, when set to @samp{#t}, will make cgit generate linenumber
22559 links for plaintext blobs printed in the tree view.
22561 Defaults to @samp{#t}.
22565 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
22566 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
22567 set any repo specific settings.
22569 Defaults to @samp{#f}.
22573 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
22574 URL used as link to a shortcut icon for cgit.
22576 Defaults to @samp{"/favicon.ico"}.
22580 @deftypevr {@code{cgit-configuration} parameter} string footer
22581 The content of the file specified with this option will be included
22582 verbatim at the bottom of all pages (i.e.@: it replaces the standard
22583 "generated by..."@: message).
22585 Defaults to @samp{""}.
22589 @deftypevr {@code{cgit-configuration} parameter} string head-include
22590 The content of the file specified with this option will be included
22591 verbatim in the HTML HEAD section on all pages.
22593 Defaults to @samp{""}.
22597 @deftypevr {@code{cgit-configuration} parameter} string header
22598 The content of the file specified with this option will be included
22599 verbatim at the top of all pages.
22601 Defaults to @samp{""}.
22605 @deftypevr {@code{cgit-configuration} parameter} file-object include
22606 Name of a configfile to include before the rest of the current config-
22609 Defaults to @samp{""}.
22613 @deftypevr {@code{cgit-configuration} parameter} string index-header
22614 The content of the file specified with this option will be included
22615 verbatim above the repository index.
22617 Defaults to @samp{""}.
22621 @deftypevr {@code{cgit-configuration} parameter} string index-info
22622 The content of the file specified with this option will be included
22623 verbatim below the heading on the repository index page.
22625 Defaults to @samp{""}.
22629 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
22630 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
22631 in the servers timezone.
22633 Defaults to @samp{#f}.
22637 @deftypevr {@code{cgit-configuration} parameter} file-object logo
22638 URL which specifies the source of an image which will be used as a logo
22641 Defaults to @samp{"/share/cgit/cgit.png"}.
22645 @deftypevr {@code{cgit-configuration} parameter} string logo-link
22646 URL loaded when clicking on the cgit logo image.
22648 Defaults to @samp{""}.
22652 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
22653 Command which will be invoked to format the Owner column of the main
22656 Defaults to @samp{""}.
22660 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
22661 Number of items to display in atom feeds view.
22663 Defaults to @samp{10}.
22667 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
22668 Number of entries to list per page in "log" view.
22670 Defaults to @samp{50}.
22674 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
22675 Number of commit message characters to display in "log" view.
22677 Defaults to @samp{80}.
22681 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
22682 Specifies the number of entries to list per page on the repository index
22685 Defaults to @samp{50}.
22689 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
22690 Specifies the maximum number of repo description characters to display
22691 on the repository index page.
22693 Defaults to @samp{80}.
22697 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
22698 Specifies the maximum size of a blob to display HTML for in KBytes.
22700 Defaults to @samp{0}.
22704 @deftypevr {@code{cgit-configuration} parameter} string max-stats
22705 Maximum statistics period. Valid values are @samp{week},@samp{month},
22706 @samp{quarter} and @samp{year}.
22708 Defaults to @samp{""}.
22712 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
22713 Mimetype for the specified filename extension.
22715 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
22716 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
22717 "image/png") (svg "image/svg+xml"))}.
22721 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
22722 Specifies the file to use for automatic mimetype lookup.
22724 Defaults to @samp{""}.
22728 @deftypevr {@code{cgit-configuration} parameter} string module-link
22729 Text which will be used as the formatstring for a hyperlink when a
22730 submodule is printed in a directory listing.
22732 Defaults to @samp{""}.
22736 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
22737 If set to the value @samp{#t} caching will be disabled.
22739 Defaults to @samp{#f}.
22743 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
22744 If set to @samp{#t} showing full author email addresses will be
22747 Defaults to @samp{#f}.
22751 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
22752 Flag which, when set to @samp{#t}, will make cgit omit the standard
22753 header on all pages.
22755 Defaults to @samp{#f}.
22759 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
22760 A list of subdirectories inside of @code{repository-directory}, relative
22761 to it, that should loaded as Git repositories. An empty list means that
22762 all subdirectories will be loaded.
22764 Defaults to @samp{()}.
22768 @deftypevr {@code{cgit-configuration} parameter} file-object readme
22769 Text which will be used as default value for @code{cgit-repo-readme}.
22771 Defaults to @samp{""}.
22775 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
22776 If set to @code{#t} and @code{repository-directory} is enabled, if any
22777 repositories are found with a suffix of @code{.git}, this suffix will be
22778 removed for the URL and name.
22780 Defaults to @samp{#f}.
22784 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
22785 Maximum number of files to consider when detecting renames.
22787 Defaults to @samp{-1}.
22791 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
22792 The way in which repositories in each section are sorted.
22794 Defaults to @samp{""}.
22798 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
22799 Text used as content for the @code{robots} meta-tag.
22801 Defaults to @samp{("noindex" "nofollow")}.
22805 @deftypevr {@code{cgit-configuration} parameter} string root-desc
22806 Text printed below the heading on the repository index page.
22808 Defaults to @samp{"a fast webinterface for the git dscm"}.
22812 @deftypevr {@code{cgit-configuration} parameter} string root-readme
22813 The content of the file specified with this option will be included
22814 verbatim below thef "about" link on the repository index page.
22816 Defaults to @samp{""}.
22820 @deftypevr {@code{cgit-configuration} parameter} string root-title
22821 Text printed as heading on the repository index page.
22823 Defaults to @samp{""}.
22827 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
22828 If set to @samp{#t} and repository-directory is enabled,
22829 repository-directory will recurse into directories whose name starts
22830 with a period. Otherwise, repository-directory will stay away from such
22831 directories, considered as "hidden". Note that this does not apply to
22832 the ".git" directory in non-bare repos.
22834 Defaults to @samp{#f}.
22838 @deftypevr {@code{cgit-configuration} parameter} list snapshots
22839 Text which specifies the default set of snapshot formats that cgit
22840 generates links for.
22842 Defaults to @samp{()}.
22846 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
22847 Name of the directory to scan for repositories (represents
22850 Defaults to @samp{"/srv/git"}.
22854 @deftypevr {@code{cgit-configuration} parameter} string section
22855 The name of the current repository section - all repositories defined
22856 after this option will inherit the current section name.
22858 Defaults to @samp{""}.
22862 @deftypevr {@code{cgit-configuration} parameter} string section-sort
22863 Flag which, when set to @samp{1}, will sort the sections on the
22864 repository listing by name.
22866 Defaults to @samp{""}.
22870 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
22871 A number which, if defined prior to repository-directory, specifies how
22872 many path elements from each repo path to use as a default section name.
22874 Defaults to @samp{0}.
22878 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
22879 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
22882 Defaults to @samp{#f}.
22886 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
22887 Specifies a command which will be invoked to format plaintext blobs in
22890 Defaults to @samp{""}.
22894 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
22895 Specifies the number of branches to display in the repository "summary"
22898 Defaults to @samp{10}.
22902 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
22903 Specifies the number of log entries to display in the repository
22906 Defaults to @samp{10}.
22910 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
22911 Specifies the number of tags to display in the repository "summary"
22914 Defaults to @samp{10}.
22918 @deftypevr {@code{cgit-configuration} parameter} string strict-export
22919 Filename which, if specified, needs to be present within the repository
22920 for cgit to allow access to that repository.
22922 Defaults to @samp{""}.
22926 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
22927 URL which, if specified, will be used as root for all cgit links.
22929 Defaults to @samp{"/"}.
22933 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
22934 A list of @dfn{cgit-repo} records to use with config.
22936 Defaults to @samp{()}.
22938 Available @code{repository-cgit-configuration} fields are:
22940 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
22941 A mask of snapshot formats for this repo that cgit generates links for,
22942 restricted by the global @code{snapshots} setting.
22944 Defaults to @samp{()}.
22948 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
22949 Override the default @code{source-filter}.
22951 Defaults to @samp{""}.
22955 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
22956 The relative URL used to access the repository.
22958 Defaults to @samp{""}.
22962 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
22963 Override the default @code{about-filter}.
22965 Defaults to @samp{""}.
22969 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
22970 Flag which, when set to @samp{age}, enables date ordering in the branch
22971 ref list, and when set to @samp{name} enables ordering by branch name.
22973 Defaults to @samp{""}.
22977 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
22978 A list of URLs which can be used to clone repo.
22980 Defaults to @samp{()}.
22984 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
22985 Override the default @code{commit-filter}.
22987 Defaults to @samp{""}.
22991 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
22992 Flag which, when set to @samp{date}, enables strict date ordering in the
22993 commit log, and when set to @samp{topo} enables strict topological
22996 Defaults to @samp{""}.
23000 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
23001 The name of the default branch for this repository. If no such branch
23002 exists in the repository, the first branch name (when sorted) is used as
23003 default instead. By default branch pointed to by HEAD, or "master" if
23004 there is no suitable HEAD.
23006 Defaults to @samp{""}.
23010 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
23011 The value to show as repository description.
23013 Defaults to @samp{""}.
23017 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
23018 The value to show as repository homepage.
23020 Defaults to @samp{""}.
23024 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
23025 Override the default @code{email-filter}.
23027 Defaults to @samp{""}.
23031 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
23032 A flag which can be used to disable the global setting
23033 @code{enable-commit-graph?}.
23035 Defaults to @samp{disabled}.
23039 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
23040 A flag which can be used to disable the global setting
23041 @code{enable-log-filecount?}.
23043 Defaults to @samp{disabled}.
23047 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
23048 A flag which can be used to disable the global setting
23049 @code{enable-log-linecount?}.
23051 Defaults to @samp{disabled}.
23055 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
23056 Flag which, when set to @code{#t}, will make cgit display remote
23057 branches in the summary and refs views.
23059 Defaults to @samp{disabled}.
23063 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
23064 A flag which can be used to override the global setting
23065 @code{enable-subject-links?}.
23067 Defaults to @samp{disabled}.
23071 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
23072 A flag which can be used to override the global setting
23073 @code{enable-html-serving?}.
23075 Defaults to @samp{disabled}.
23079 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
23080 Flag which, when set to @code{#t}, hides the repository from the
23083 Defaults to @samp{#f}.
23087 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
23088 Flag which, when set to @samp{#t}, ignores the repository.
23090 Defaults to @samp{#f}.
23094 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
23095 URL which specifies the source of an image which will be used as a logo
23096 on this repo’s pages.
23098 Defaults to @samp{""}.
23102 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
23103 URL loaded when clicking on the cgit logo image.
23105 Defaults to @samp{""}.
23109 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
23110 Override the default @code{owner-filter}.
23112 Defaults to @samp{""}.
23116 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
23117 Text which will be used as the formatstring for a hyperlink when a
23118 submodule is printed in a directory listing. The arguments for the
23119 formatstring are the path and SHA1 of the submodule commit.
23121 Defaults to @samp{""}.
23125 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
23126 Text which will be used as the formatstring for a hyperlink when a
23127 submodule with the specified subdirectory path is printed in a directory
23130 Defaults to @samp{()}.
23134 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
23135 Override the default maximum statistics period.
23137 Defaults to @samp{""}.
23141 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
23142 The value to show as repository name.
23144 Defaults to @samp{""}.
23148 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
23149 A value used to identify the owner of the repository.
23151 Defaults to @samp{""}.
23155 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
23156 An absolute path to the repository directory.
23158 Defaults to @samp{""}.
23162 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
23163 A path (relative to repo) which specifies a file to include verbatim as
23164 the "About" page for this repo.
23166 Defaults to @samp{""}.
23170 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
23171 The name of the current repository section - all repositories defined
23172 after this option will inherit the current section name.
23174 Defaults to @samp{""}.
23178 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
23179 Extra options will be appended to cgitrc file.
23181 Defaults to @samp{()}.
23187 @deftypevr {@code{cgit-configuration} parameter} list extra-options
23188 Extra options will be appended to cgitrc file.
23190 Defaults to @samp{()}.
23195 @c %end of fragment
23197 However, it could be that you just want to get a @code{cgitrc} up and
23198 running. In that case, you can pass an @code{opaque-cgit-configuration}
23199 as a record to @code{cgit-service-type}. As its name indicates, an
23200 opaque configuration does not have easy reflective capabilities.
23202 Available @code{opaque-cgit-configuration} fields are:
23204 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
23208 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
23209 The contents of the @code{cgitrc}, as a string.
23212 For example, if your @code{cgitrc} is just the empty string, you
23213 could instantiate a cgit service like this:
23216 (service cgit-service-type
23217 (opaque-cgit-configuration
23221 @subsubheading Gitolite Service
23223 @cindex Gitolite service
23224 @cindex Git, hosting
23225 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
23226 repositories on a central server.
23228 Gitolite can handle multiple repositories and users, and supports flexible
23229 configuration of the permissions for the users on the repositories.
23231 The following example will configure Gitolite using the default @code{git}
23232 user, and the provided SSH public key.
23235 (service gitolite-service-type
23236 (gitolite-configuration
23237 (admin-pubkey (plain-file
23239 "ssh-rsa AAAA... guix@@example.com"))))
23242 Gitolite is configured through a special admin repository which you can clone,
23243 for example, if you setup Gitolite on @code{example.com}, you would run the
23244 following command to clone the admin repository.
23247 git clone git@@example.com:gitolite-admin
23250 When the Gitolite service is activated, the provided @code{admin-pubkey} will
23251 be inserted in to the @file{keydir} directory in the gitolite-admin
23252 repository. If this results in a change in the repository, it will be
23253 committed using the message ``gitolite setup by GNU Guix''.
23255 @deftp {Data Type} gitolite-configuration
23256 Data type representing the configuration for @code{gitolite-service-type}.
23259 @item @code{package} (default: @var{gitolite})
23260 Gitolite package to use.
23262 @item @code{user} (default: @var{git})
23263 User to use for Gitolite. This will be user that you use when accessing
23266 @item @code{group} (default: @var{git})
23267 Group to use for Gitolite.
23269 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
23270 Directory in which to store the Gitolite configuration and repositories.
23272 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
23273 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
23274 representing the configuration for Gitolite.
23276 @item @code{admin-pubkey} (default: @var{#f})
23277 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
23278 setup Gitolite. This will be inserted in to the @file{keydir} directory
23279 within the gitolite-admin repository.
23281 To specify the SSH key as a string, use the @code{plain-file} function.
23284 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
23290 @deftp {Data Type} gitolite-rc-file
23291 Data type representing the Gitolite RC file.
23294 @item @code{umask} (default: @code{#o0077})
23295 This controls the permissions Gitolite sets on the repositories and their
23298 A value like @code{#o0027} will give read access to the group used by Gitolite
23299 (by default: @code{git}). This is necessary when using Gitolite with software
23300 like cgit or gitweb.
23302 @item @code{git-config-keys} (default: @code{""})
23303 Gitolite allows you to set git config values using the "config" keyword. This
23304 setting allows control over the config keys to accept.
23306 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
23307 Set the role names allowed to be used by users running the perms command.
23309 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
23310 This setting controls the commands and features to enable within Gitolite.
23316 @node Game Services
23317 @subsection Game Services
23319 @subsubheading The Battle for Wesnoth Service
23321 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
23322 based tactical strategy game, with several single player campaigns, and
23323 multiplayer games (both networked and local).
23325 @defvar {Scheme Variable} wesnothd-service-type
23326 Service type for the wesnothd service. Its value must be a
23327 @code{wesnothd-configuration} object. To run wesnothd in the default
23328 configuration, instantiate it as:
23331 (service wesnothd-service-type)
23335 @deftp {Data Type} wesnothd-configuration
23336 Data type representing the configuration of @command{wesnothd}.
23339 @item @code{package} (default: @code{wesnoth-server})
23340 The wesnoth server package to use.
23342 @item @code{port} (default: @code{15000})
23343 The port to bind the server to.
23347 @node Miscellaneous Services
23348 @subsection Miscellaneous Services
23350 @cindex fingerprint
23351 @subsubheading Fingerprint Service
23353 The @code{(gnu services authentication)} module provides a DBus service to
23354 read and identify fingerprints via a fingerprint sensor.
23356 @defvr {Scheme Variable} fprintd-service-type
23357 The service type for @command{fprintd}, which provides the fingerprint
23358 reading capability.
23361 (service fprintd-service-type)
23366 @subsubheading System Control Service
23368 The @code{(gnu services sysctl)} provides a service to configure kernel
23369 parameters at boot.
23371 @defvr {Scheme Variable} sysctl-service-type
23372 The service type for @command{sysctl}, which modifies kernel parameters
23373 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
23377 (service sysctl-service-type
23378 (sysctl-configuration
23379 (settings '(("net.ipv4.ip_forward" . "1")))))
23383 @deftp {Data Type} sysctl-configuration
23384 The data type representing the configuration of @command{sysctl}.
23387 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
23388 The @command{sysctl} executable to use.
23390 @item @code{settings} (default: @code{'()})
23391 An association list specifies kernel parameters and their values.
23396 @subsubheading PC/SC Smart Card Daemon Service
23398 The @code{(gnu services security-token)} module provides the following service
23399 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
23400 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
23401 manager that coordinates communications with smart card readers, smart cards
23402 and cryptographic tokens that are connected to the system.
23404 @defvr {Scheme Variable} pcscd-service-type
23405 Service type for the @command{pcscd} service. Its value must be a
23406 @code{pcscd-configuration} object. To run pcscd in the default
23407 configuration, instantiate it as:
23410 (service pcscd-service-type)
23414 @deftp {Data Type} pcscd-configuration
23415 The data type representing the configuration of @command{pcscd}.
23418 @item @code{pcsc-lite} (default: @code{pcsc-lite})
23419 The pcsc-lite package that provides pcscd.
23420 @item @code{usb-drivers} (default: @code{(list ccid)})
23421 List of packages that provide USB drivers to pcscd. Drivers are expected to be
23422 under @file{pcsc/drivers} in the store directory of the package.
23427 @subsubheading Lirc Service
23429 The @code{(gnu services lirc)} module provides the following service.
23431 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
23432 [#:device #f] [#:driver #f] [#:config-file #f] @
23433 [#:extra-options '()]
23434 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
23435 decodes infrared signals from remote controls.
23437 Optionally, @var{device}, @var{driver} and @var{config-file}
23438 (configuration file name) may be specified. See @command{lircd} manual
23441 Finally, @var{extra-options} is a list of additional command-line options
23442 passed to @command{lircd}.
23446 @subsubheading Spice Service
23448 The @code{(gnu services spice)} module provides the following service.
23450 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
23451 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
23452 that enables sharing the clipboard with a vm and setting the guest display
23453 resolution when the graphical console window resizes.
23456 @cindex inputattach
23457 @subsubheading inputattach Service
23459 @cindex tablet input, for Xorg
23460 @cindex touchscreen input, for Xorg
23461 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
23462 use input devices such as Wacom tablets, touchscreens, or joysticks with the
23463 Xorg display server.
23465 @deffn {Scheme Variable} inputattach-service-type
23466 Type of a service that runs @command{inputattach} on a device and
23467 dispatches events from it.
23470 @deftp {Data Type} inputattach-configuration
23472 @item @code{device-type} (default: @code{"wacom"})
23473 The type of device to connect to. Run @command{inputattach --help}, from the
23474 @code{inputattach} package, to see the list of supported device types.
23476 @item @code{device} (default: @code{"/dev/ttyS0"})
23477 The device file to connect to the device.
23479 @item @code{log-file} (default: @code{#f})
23480 If true, this must be the name of a file to log messages to.
23484 @subsection Dictionary Services
23486 The @code{(gnu services dict)} module provides the following service:
23488 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
23489 Return a service that runs the @command{dicod} daemon, an implementation
23490 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
23492 The optional @var{config} argument specifies the configuration for
23493 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
23494 default it serves the GNU Collaborative International Dictonary of English.
23496 You can add @command{open localhost} to your @file{~/.dico} file to make
23497 @code{localhost} the default server for @command{dico} client
23498 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
23501 @deftp {Data Type} dicod-configuration
23502 Data type representing the configuration of dicod.
23505 @item @code{dico} (default: @var{dico})
23506 Package object of the GNU Dico dictionary server.
23508 @item @code{interfaces} (default: @var{'("localhost")})
23509 This is the list of IP addresses and ports and possibly socket file
23510 names to listen to (@pxref{Server Settings, @code{listen} directive,,
23511 dico, GNU Dico Manual}).
23513 @item @code{handlers} (default: @var{'()})
23514 List of @code{<dicod-handler>} objects denoting handlers (module instances).
23516 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
23517 List of @code{<dicod-database>} objects denoting dictionaries to be served.
23521 @deftp {Data Type} dicod-handler
23522 Data type representing a dictionary handler (module instance).
23526 Name of the handler (module instance).
23528 @item @code{module} (default: @var{#f})
23529 Name of the dicod module of the handler (instance). If it is @code{#f},
23530 the module has the same name as the handler.
23531 (@pxref{Modules,,, dico, GNU Dico Manual}).
23533 @item @code{options}
23534 List of strings or gexps representing the arguments for the module handler
23538 @deftp {Data Type} dicod-database
23539 Data type representing a dictionary database.
23543 Name of the database, will be used in DICT commands.
23545 @item @code{handler}
23546 Name of the dicod handler (module instance) used by this database
23547 (@pxref{Handlers,,, dico, GNU Dico Manual}).
23549 @item @code{complex?} (default: @var{#f})
23550 Whether the database configuration complex. The complex configuration
23551 will need a corresponding @code{<dicod-handler>} object, otherwise not.
23553 @item @code{options}
23554 List of strings or gexps representing the arguments for the database
23555 (@pxref{Databases,,, dico, GNU Dico Manual}).
23559 @defvr {Scheme Variable} %dicod-database:gcide
23560 A @code{<dicod-database>} object serving the GNU Collaborative International
23561 Dictionary of English using the @code{gcide} package.
23564 The following is an example @code{dicod-service} configuration.
23567 (dicod-service #:config
23568 (dicod-configuration
23569 (handlers (list (dicod-handler
23573 (list #~(string-append "dbdir=" #$wordnet))))))
23574 (databases (list (dicod-database
23577 (handler "wordnet")
23578 (options '("database=wn")))
23579 %dicod-database:gcide))))
23583 @subsubheading Docker Service
23585 The @code{(gnu services docker)} module provides the following service.
23587 @defvr {Scheme Variable} docker-service-type
23589 This is the type of the service that runs @url{https://www.docker.com,Docker},
23590 a daemon that can execute application bundles (sometimes referred to as
23591 ``containers'') in isolated environments.
23595 @deftp {Data Type} docker-configuration
23596 This is the data type representing the configuration of Docker and Containerd.
23600 @item @code{package} (default: @code{docker})
23601 The Docker package to use.
23603 @item @code{containerd} (default: @var{containerd})
23604 The Containerd package to use.
23609 @node Setuid Programs
23610 @section Setuid Programs
23612 @cindex setuid programs
23613 Some programs need to run with ``root'' privileges, even when they are
23614 launched by unprivileged users. A notorious example is the
23615 @command{passwd} program, which users can run to change their
23616 password, and which needs to access the @file{/etc/passwd} and
23617 @file{/etc/shadow} files---something normally restricted to root, for
23618 obvious security reasons. To address that, these executables are
23619 @dfn{setuid-root}, meaning that they always run with root privileges
23620 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
23621 for more info about the setuid mechanism.)
23623 The store itself @emph{cannot} contain setuid programs: that would be a
23624 security issue since any user on the system can write derivations that
23625 populate the store (@pxref{The Store}). Thus, a different mechanism is
23626 used: instead of changing the setuid bit directly on files that are in
23627 the store, we let the system administrator @emph{declare} which programs
23628 should be setuid root.
23630 The @code{setuid-programs} field of an @code{operating-system}
23631 declaration contains a list of G-expressions denoting the names of
23632 programs to be setuid-root (@pxref{Using the Configuration System}).
23633 For instance, the @command{passwd} program, which is part of the Shadow
23634 package, can be designated by this G-expression (@pxref{G-Expressions}):
23637 #~(string-append #$shadow "/bin/passwd")
23640 A default set of setuid programs is defined by the
23641 @code{%setuid-programs} variable of the @code{(gnu system)} module.
23643 @defvr {Scheme Variable} %setuid-programs
23644 A list of G-expressions denoting common programs that are setuid-root.
23646 The list includes commands such as @command{passwd}, @command{ping},
23647 @command{su}, and @command{sudo}.
23650 Under the hood, the actual setuid programs are created in the
23651 @file{/run/setuid-programs} directory at system activation time. The
23652 files in this directory refer to the ``real'' binaries, which are in the
23655 @node X.509 Certificates
23656 @section X.509 Certificates
23658 @cindex HTTPS, certificates
23659 @cindex X.509 certificates
23661 Web servers available over HTTPS (that is, HTTP over the transport-layer
23662 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
23663 that the client can then use to @emph{authenticate} the server. To do
23664 that, clients verify that the server's certificate is signed by a
23665 so-called @dfn{certificate authority} (CA). But to verify the CA's
23666 signature, clients must have first acquired the CA's certificate.
23668 Web browsers such as GNU@tie{}IceCat include their own set of CA
23669 certificates, such that they are able to verify CA signatures
23672 However, most other programs that can talk HTTPS---@command{wget},
23673 @command{git}, @command{w3m}, etc.---need to be told where CA
23674 certificates can be found.
23676 @cindex @code{nss-certs}
23677 In Guix, this is done by adding a package that provides certificates
23678 to the @code{packages} field of the @code{operating-system} declaration
23679 (@pxref{operating-system Reference}). Guix includes one such package,
23680 @code{nss-certs}, which is a set of CA certificates provided as part of
23681 Mozilla's Network Security Services.
23683 Note that it is @emph{not} part of @var{%base-packages}, so you need to
23684 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
23685 most applications and libraries look for certificates by default, points
23686 to the certificates installed globally.
23688 Unprivileged users, including users of Guix on a foreign distro,
23689 can also install their own certificate package in
23690 their profile. A number of environment variables need to be defined so
23691 that applications and libraries know where to find them. Namely, the
23692 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
23693 variables. Some applications add their own environment variables; for
23694 instance, the Git version control system honors the certificate bundle
23695 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
23696 would typically run something like:
23699 $ guix install nss-certs
23700 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
23701 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
23702 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
23705 As another example, R requires the @code{CURL_CA_BUNDLE} environment
23706 variable to point to a certificate bundle, so you would have to run
23707 something like this:
23710 $ guix install nss-certs
23711 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
23714 For other applications you may want to look up the required environment
23715 variable in the relevant documentation.
23718 @node Name Service Switch
23719 @section Name Service Switch
23721 @cindex name service switch
23723 The @code{(gnu system nss)} module provides bindings to the
23724 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
23725 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
23726 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
23727 extended with new ``name'' lookup methods for system databases, which
23728 includes host names, service names, user accounts, and more (@pxref{Name
23729 Service Switch, System Databases and Name Service Switch,, libc, The GNU
23730 C Library Reference Manual}).
23732 The NSS configuration specifies, for each system database, which lookup
23733 method is to be used, and how the various methods are chained
23734 together---for instance, under which circumstances NSS should try the
23735 next method in the list. The NSS configuration is given in the
23736 @code{name-service-switch} field of @code{operating-system} declarations
23737 (@pxref{operating-system Reference, @code{name-service-switch}}).
23740 @cindex .local, host name lookup
23741 As an example, the declaration below configures the NSS to use the
23742 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
23743 back-end}, which supports host name lookups over multicast DNS (mDNS)
23744 for host names ending in @code{.local}:
23747 (name-service-switch
23748 (hosts (list %files ;first, check /etc/hosts
23750 ;; If the above did not succeed, try
23751 ;; with 'mdns_minimal'.
23753 (name "mdns_minimal")
23755 ;; 'mdns_minimal' is authoritative for
23756 ;; '.local'. When it returns "not found",
23757 ;; no need to try the next methods.
23758 (reaction (lookup-specification
23759 (not-found => return))))
23761 ;; Then fall back to DNS.
23765 ;; Finally, try with the "full" 'mdns'.
23770 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
23771 contains this configuration, so you will not have to type it if all you
23772 want is to have @code{.local} host lookup working.
23774 Note that, in this case, in addition to setting the
23775 @code{name-service-switch} of the @code{operating-system} declaration,
23776 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
23777 @code{avahi-service-type}}), or @var{%desktop-services}, which includes it
23778 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
23779 to the name service cache daemon (@pxref{Base Services,
23780 @code{nscd-service}}).
23782 For convenience, the following variables provide typical NSS
23785 @defvr {Scheme Variable} %default-nss
23786 This is the default name service switch configuration, a
23787 @code{name-service-switch} object.
23790 @defvr {Scheme Variable} %mdns-host-lookup-nss
23791 This is the name service switch configuration with support for host name
23792 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
23795 The reference for name service switch configuration is given below. It
23796 is a direct mapping of the configuration file format of the C library , so
23797 please refer to the C library manual for more information (@pxref{NSS
23798 Configuration File,,, libc, The GNU C Library Reference Manual}).
23799 Compared to the configuration file format of libc NSS, it has the advantage
23800 not only of adding this warm parenthetic feel that we like, but also
23801 static checks: you will know about syntax errors and typos as soon as you
23802 run @command{guix system}.
23804 @deftp {Data Type} name-service-switch
23806 This is the data type representation the configuration of libc's name
23807 service switch (NSS). Each field below represents one of the supported
23824 The system databases handled by the NSS. Each of these fields must be a
23825 list of @code{<name-service>} objects (see below).
23829 @deftp {Data Type} name-service
23831 This is the data type representing an actual name service and the
23832 associated lookup action.
23836 A string denoting the name service (@pxref{Services in the NSS
23837 configuration,,, libc, The GNU C Library Reference Manual}).
23839 Note that name services listed here must be visible to nscd. This is
23840 achieved by passing the @code{#:name-services} argument to
23841 @code{nscd-service} the list of packages providing the needed name
23842 services (@pxref{Base Services, @code{nscd-service}}).
23845 An action specified using the @code{lookup-specification} macro
23846 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
23847 Reference Manual}). For example:
23850 (lookup-specification (unavailable => continue)
23851 (success => return))
23856 @node Initial RAM Disk
23857 @section Initial RAM Disk
23860 @cindex initial RAM disk
23861 For bootstrapping purposes, the Linux-Libre kernel is passed an
23862 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
23863 root file system as well as an initialization script. The latter is
23864 responsible for mounting the real root file system, and for loading any
23865 kernel modules that may be needed to achieve that.
23867 The @code{initrd-modules} field of an @code{operating-system}
23868 declaration allows you to specify Linux-libre kernel modules that must
23869 be available in the initrd. In particular, this is where you would list
23870 modules needed to actually drive the hard disk where your root partition
23871 is---although the default value of @code{initrd-modules} should cover
23872 most use cases. For example, assuming you need the @code{megaraid_sas}
23873 module in addition to the default modules to be able to access your root
23874 file system, you would write:
23879 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
23882 @defvr {Scheme Variable} %base-initrd-modules
23883 This is the list of kernel modules included in the initrd by default.
23886 Furthermore, if you need lower-level customization, the @code{initrd}
23887 field of an @code{operating-system} declaration allows
23888 you to specify which initrd you would like to use. The @code{(gnu
23889 system linux-initrd)} module provides three ways to build an initrd: the
23890 high-level @code{base-initrd} procedure and the low-level
23891 @code{raw-initrd} and @code{expression->initrd} procedures.
23893 The @code{base-initrd} procedure is intended to cover most common uses.
23894 For example, if you want to add a bunch of kernel modules to be loaded
23895 at boot time, you can define the @code{initrd} field of the operating
23896 system declaration like this:
23899 (initrd (lambda (file-systems . rest)
23900 ;; Create a standard initrd but set up networking
23901 ;; with the parameters QEMU expects by default.
23902 (apply base-initrd file-systems
23903 #:qemu-networking? #t
23907 The @code{base-initrd} procedure also handles common use cases that
23908 involves using the system as a QEMU guest, or as a ``live'' system with
23909 volatile root file system.
23911 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
23912 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
23913 such as trying to guess which kernel modules and packages should be included
23914 to the initrd. An example use of @code{raw-initrd} is when a user has
23915 a custom Linux kernel configuration and default kernel modules included by
23916 @code{base-initrd} are not available.
23918 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
23919 honors several options passed on the Linux kernel command line
23920 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
23921 @code{-append} option of QEMU), notably:
23924 @item --load=@var{boot}
23925 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
23926 program, once it has mounted the root file system.
23928 Guix uses this option to yield control to a boot program that runs the
23929 service activation programs and then spawns the GNU@tie{}Shepherd, the
23930 initialization system.
23932 @item --root=@var{root}
23933 Mount @var{root} as the root file system. @var{root} can be a
23934 device name like @code{/dev/sda1}, a file system label, or a file system
23937 @item --system=@var{system}
23938 Have @file{/run/booted-system} and @file{/run/current-system} point to
23941 @item modprobe.blacklist=@var{modules}@dots{}
23942 @cindex module, black-listing
23943 @cindex black list, of kernel modules
23944 Instruct the initial RAM disk as well as the @command{modprobe} command
23945 (from the kmod package) to refuse to load @var{modules}. @var{modules}
23946 must be a comma-separated list of module names---e.g.,
23947 @code{usbkbd,9pnet}.
23950 Start a read-eval-print loop (REPL) from the initial RAM disk before it
23951 tries to load kernel modules and to mount the root file system. Our
23952 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
23953 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
23954 Manual}, for more information on Guile's REPL.
23958 Now that you know all the features that initial RAM disks produced by
23959 @code{base-initrd} and @code{raw-initrd} provide,
23960 here is how to use it and customize it further.
23963 @cindex initial RAM disk
23964 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
23965 [#:linux-modules '()] [#:mapped-devices '()] @
23966 [#:keyboard-layout #f] @
23967 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
23968 Return a derivation that builds a raw initrd. @var{file-systems} is
23969 a list of file systems to be mounted by the initrd, possibly in addition to
23970 the root file system specified on the kernel command line via @code{--root}.
23971 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
23972 @var{mapped-devices} is a list of device mappings to realize before
23973 @var{file-systems} are mounted (@pxref{Mapped Devices}).
23974 @var{helper-packages} is a list of packages to be copied in the initrd. It may
23975 include @code{e2fsck/static} or other packages needed by the initrd to check
23976 the root file system.
23978 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
23979 the desired console keyboard layout. This is done before @var{mapped-devices}
23980 are set up and before @var{file-systems} are mounted such that, should the
23981 user need to enter a passphrase or use the REPL, this happens using the
23982 intended keyboard layout.
23984 When @var{qemu-networking?} is true, set up networking with the standard QEMU
23985 parameters. When @var{virtio?} is true, load additional modules so that the
23986 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
23988 When @var{volatile-root?} is true, the root file system is writable but any changes
23992 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
23993 [#:mapped-devices '()] [#:keyboard-layout #f] @
23994 [#:qemu-networking? #f] [#:volatile-root? #f] @
23995 [#:linux-modules '()]
23996 Return as a file-like object a generic initrd, with kernel
23997 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
23998 mounted by the initrd, possibly in addition to the root file system specified
23999 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
24000 mappings to realize before @var{file-systems} are mounted.
24002 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
24003 the desired console keyboard layout. This is done before @var{mapped-devices}
24004 are set up and before @var{file-systems} are mounted such that, should the
24005 user need to enter a passphrase or use the REPL, this happens using the
24006 intended keyboard layout.
24008 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
24010 The initrd is automatically populated with all the kernel modules necessary
24011 for @var{file-systems} and for the given options. Additional kernel
24012 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
24013 loaded at boot time in the order in which they appear.
24016 Needless to say, the initrds we produce and use embed a
24017 statically-linked Guile, and the initialization program is a Guile
24018 program. That gives a lot of flexibility. The
24019 @code{expression->initrd} procedure builds such an initrd, given the
24020 program to run in that initrd.
24022 @deffn {Scheme Procedure} expression->initrd @var{exp} @
24023 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
24024 Return as a file-like object a Linux initrd (a gzipped cpio archive)
24025 containing @var{guile} and that evaluates @var{exp}, a G-expression,
24026 upon booting. All the derivations referenced by @var{exp} are
24027 automatically copied to the initrd.
24030 @node Bootloader Configuration
24031 @section Bootloader Configuration
24034 @cindex boot loader
24036 The operating system supports multiple bootloaders. The bootloader is
24037 configured using @code{bootloader-configuration} declaration. All the
24038 fields of this structure are bootloader agnostic except for one field,
24039 @code{bootloader} that indicates the bootloader to be configured and
24042 Some of the bootloaders do not honor every field of
24043 @code{bootloader-configuration}. For instance, the extlinux
24044 bootloader does not support themes and thus ignores the @code{theme}
24047 @deftp {Data Type} bootloader-configuration
24048 The type of a bootloader configuration declaration.
24052 @item @code{bootloader}
24053 @cindex EFI, bootloader
24054 @cindex UEFI, bootloader
24055 @cindex BIOS, bootloader
24056 The bootloader to use, as a @code{bootloader} object. For now
24057 @code{grub-bootloader}, @code{grub-efi-bootloader},
24058 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
24060 @vindex grub-efi-bootloader
24061 @code{grub-efi-bootloader} allows to boot on modern systems using the
24062 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
24063 use if the installation image contains a @file{/sys/firmware/efi} directory
24064 when you boot it on your system.
24066 @vindex grub-bootloader
24067 @code{grub-bootloader} allows you to boot in particular Intel-based machines
24068 in ``legacy'' BIOS mode.
24070 @cindex ARM, bootloaders
24071 @cindex AArch64, bootloaders
24072 Available bootloaders are described in @code{(gnu bootloader @dots{})}
24073 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
24074 of bootloaders for a wide range of ARM and AArch64 systems, using the
24075 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
24077 @item @code{target}
24078 This is a string denoting the target onto which to install the
24081 The interpretation depends on the bootloader in question. For
24082 @code{grub-bootloader}, for example, it should be a device name understood by
24083 the bootloader @command{installer} command, such as @code{/dev/sda} or
24084 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
24085 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
24086 system, usually @file{/boot/efi}.
24088 @item @code{menu-entries} (default: @code{()})
24089 A possibly empty list of @code{menu-entry} objects (see below), denoting
24090 entries to appear in the bootloader menu, in addition to the current
24091 system entry and the entry pointing to previous system generations.
24093 @item @code{default-entry} (default: @code{0})
24094 The index of the default boot menu entry. Index 0 is for the entry of the
24097 @item @code{timeout} (default: @code{5})
24098 The number of seconds to wait for keyboard input before booting. Set to
24099 0 to boot immediately, and to -1 to wait indefinitely.
24101 @cindex keyboard layout, for the bootloader
24102 @item @code{keyboard-layout} (default: @code{#f})
24103 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
24104 layout, usually US@tie{}English (``qwerty'').
24106 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
24110 This option is currently ignored by bootloaders other than @code{grub} and
24114 @item @code{theme} (default: @var{#f})
24115 The bootloader theme object describing the theme to use. If no theme
24116 is provided, some bootloaders might use a default theme, that's true
24119 @item @code{terminal-outputs} (default: @code{'gfxterm})
24120 The output terminals used for the bootloader boot menu, as a list of
24121 symbols. GRUB accepts the values: @code{console}, @code{serial},
24122 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
24123 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
24124 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
24125 configuration,,, grub,GNU GRUB manual}).
24127 @item @code{terminal-inputs} (default: @code{'()})
24128 The input terminals used for the bootloader boot menu, as a list of
24129 symbols. For GRUB, the default is the native platform terminal as
24130 determined at run-time. GRUB accepts the values: @code{console},
24131 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
24132 @code{usb_keyboard}. This field corresponds to the GRUB variable
24133 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
24136 @item @code{serial-unit} (default: @code{#f})
24137 The serial unit used by the bootloader, as an integer from 0 to 3.
24138 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
24139 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
24141 @item @code{serial-speed} (default: @code{#f})
24142 The speed of the serial interface, as an integer. For GRUB, the
24143 default value is chosen at run-time; currently GRUB chooses
24144 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
24151 Should you want to list additional boot menu entries @i{via} the
24152 @code{menu-entries} field above, you will need to create them with the
24153 @code{menu-entry} form. For example, imagine you want to be able to
24154 boot another distro (hard to imagine!), you can define a menu entry
24159 (label "The Other Distro")
24160 (linux "/boot/old/vmlinux-2.6.32")
24161 (linux-arguments '("root=/dev/sda2"))
24162 (initrd "/boot/old/initrd"))
24167 @deftp {Data Type} menu-entry
24168 The type of an entry in the bootloader menu.
24173 The label to show in the menu---e.g., @code{"GNU"}.
24176 The Linux kernel image to boot, for example:
24179 (file-append linux-libre "/bzImage")
24182 For GRUB, it is also possible to specify a device explicitly in the
24183 file path using GRUB's device naming convention (@pxref{Naming
24184 convention,,, grub, GNU GRUB manual}), for example:
24187 "(hd0,msdos1)/boot/vmlinuz"
24190 If the device is specified explicitly as above, then the @code{device}
24191 field is ignored entirely.
24193 @item @code{linux-arguments} (default: @code{()})
24194 The list of extra Linux kernel command-line arguments---e.g.,
24195 @code{("console=ttyS0")}.
24197 @item @code{initrd}
24198 A G-Expression or string denoting the file name of the initial RAM disk
24199 to use (@pxref{G-Expressions}).
24200 @item @code{device} (default: @code{#f})
24201 The device where the kernel and initrd are to be found---i.e., for GRUB,
24202 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
24204 This may be a file system label (a string), a file system UUID (a
24205 bytevector, @pxref{File Systems}), or @code{#f}, in which case
24206 the bootloader will search the device containing the file specified by
24207 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
24208 must @emph{not} be an OS device name such as @file{/dev/sda1}.
24213 @c FIXME: Write documentation once it's stable.
24214 For now only GRUB has theme support. GRUB themes are created using
24215 the @code{grub-theme} form, which is not documented yet.
24217 @defvr {Scheme Variable} %default-theme
24218 This is the default GRUB theme used by the operating system if no
24219 @code{theme} field is specified in @code{bootloader-configuration}
24222 It comes with a fancy background image displaying the GNU and Guix
24227 @node Invoking guix system
24228 @section Invoking @code{guix system}
24230 Once you have written an operating system declaration as seen in the
24231 previous section, it can be @dfn{instantiated} using the @command{guix
24232 system} command. The synopsis is:
24235 guix system @var{options}@dots{} @var{action} @var{file}
24238 @var{file} must be the name of a file containing an
24239 @code{operating-system} declaration. @var{action} specifies how the
24240 operating system is instantiated. Currently the following values are
24245 Display available service type definitions that match the given regular
24246 expressions, sorted by relevance:
24249 $ guix system search console font
24250 name: console-fonts
24251 location: gnu/services/base.scm:729:2
24252 extends: shepherd-root
24253 description: Install the given fonts on the specified ttys (fonts are
24254 + per virtual console on GNU/Linux). The value of this service is a list
24255 + of tty/font pairs like:
24257 + '(("tty1" . "LatGrkCyr-8x16"))
24261 location: gnu/services/base.scm:1048:2
24262 extends: shepherd-root
24263 description: Provide console login using the `mingetty' program.
24267 location: gnu/services/base.scm:775:2
24269 description: Provide a console log-in service as specified by its
24270 + configuration value, a `login-configuration' object.
24276 As for @command{guix package --search}, the result is written in
24277 @code{recutils} format, which makes it easy to filter the output
24278 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
24281 Build the operating system described in @var{file}, activate it, and
24282 switch to it@footnote{This action (and the related actions
24283 @code{switch-generation} and @code{roll-back}) are usable only on
24284 systems already running Guix System.}.
24286 This effects all the configuration specified in @var{file}: user
24287 accounts, system services, global package list, setuid programs, etc.
24288 The command starts system services specified in @var{file} that are not
24289 currently running; if a service is currently running this command will
24290 arrange for it to be upgraded the next time it is stopped (e.g.@: by
24291 @code{herd stop X} or @code{herd restart X}).
24293 This command creates a new generation whose number is one greater than
24294 the current generation (as reported by @command{guix system
24295 list-generations}). If that generation already exists, it will be
24296 overwritten. This behavior mirrors that of @command{guix package}
24297 (@pxref{Invoking guix package}).
24299 It also adds a bootloader menu entry for the new OS configuration,
24300 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
24301 entries for older configurations to a submenu, allowing you to choose
24302 an older system generation at boot time should you need it.
24305 @c The paragraph below refers to the problem discussed at
24306 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
24307 It is highly recommended to run @command{guix pull} once before you run
24308 @command{guix system reconfigure} for the first time (@pxref{Invoking
24309 guix pull}). Failing to do that you would see an older version of Guix
24310 once @command{reconfigure} has completed.
24313 @item switch-generation
24314 @cindex generations
24315 Switch to an existing system generation. This action atomically
24316 switches the system profile to the specified system generation. It
24317 also rearranges the system's existing bootloader menu entries. It
24318 makes the menu entry for the specified system generation the default,
24319 and it moves the entries for the other generatiors to a submenu, if
24320 supported by the bootloader being used. The next time the system
24321 boots, it will use the specified system generation.
24323 The bootloader itself is not being reinstalled when using this
24324 command. Thus, the installed bootloader is used with an updated
24325 configuration file.
24327 The target generation can be specified explicitly by its generation
24328 number. For example, the following invocation would switch to system
24332 guix system switch-generation 7
24335 The target generation can also be specified relative to the current
24336 generation with the form @code{+N} or @code{-N}, where @code{+3} means
24337 ``3 generations ahead of the current generation,'' and @code{-1} means
24338 ``1 generation prior to the current generation.'' When specifying a
24339 negative value such as @code{-1}, you must precede it with @code{--} to
24340 prevent it from being parsed as an option. For example:
24343 guix system switch-generation -- -1
24346 Currently, the effect of invoking this action is @emph{only} to switch
24347 the system profile to an existing generation and rearrange the
24348 bootloader menu entries. To actually start using the target system
24349 generation, you must reboot after running this action. In the future,
24350 it will be updated to do the same things as @command{reconfigure},
24351 like activating and deactivating services.
24353 This action will fail if the specified generation does not exist.
24356 @cindex rolling back
24357 Switch to the preceding system generation. The next time the system
24358 boots, it will use the preceding system generation. This is the inverse
24359 of @command{reconfigure}, and it is exactly the same as invoking
24360 @command{switch-generation} with an argument of @code{-1}.
24362 Currently, as with @command{switch-generation}, you must reboot after
24363 running this action to actually start using the preceding system
24366 @item delete-generations
24367 @cindex deleting system generations
24368 @cindex saving space
24369 Delete system generations, making them candidates for garbage collection
24370 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
24373 This works in the same way as @command{guix package --delete-generations}
24374 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
24375 arguments, all system generations but the current one are deleted:
24378 guix system delete-generations
24381 You can also select the generations you want to delete. The example below
24382 deletes all the system generations that are more than two month old:
24385 guix system delete-generations 2m
24388 Running this command automatically reinstalls the bootloader with an updated
24389 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
24390 longer lists the generations that have been deleted.
24393 Build the derivation of the operating system, which includes all the
24394 configuration files and programs needed to boot and run the system.
24395 This action does not actually install anything.
24398 Populate the given directory with all the files necessary to run the
24399 operating system specified in @var{file}. This is useful for first-time
24400 installations of Guix System. For instance:
24403 guix system init my-os-config.scm /mnt
24406 copies to @file{/mnt} all the store items required by the configuration
24407 specified in @file{my-os-config.scm}. This includes configuration
24408 files, packages, and so on. It also creates other essential files
24409 needed for the system to operate correctly---e.g., the @file{/etc},
24410 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
24412 This command also installs bootloader on the target specified in
24413 @file{my-os-config}, unless the @option{--no-bootloader} option was
24417 @cindex virtual machine
24419 @anchor{guix system vm}
24420 Build a virtual machine that contains the operating system declared in
24421 @var{file}, and return a script to run that virtual machine (VM).
24424 The @code{vm} action and others below
24425 can use KVM support in the Linux-libre kernel. Specifically, if the
24426 machine has hardware virtualization support, the corresponding
24427 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
24428 must exist and be readable and writable by the user and by the
24429 build users of the daemon (@pxref{Build Environment Setup}).
24432 Arguments given to the script are passed to QEMU as in the example
24433 below, which enables networking and requests 1@tie{}GiB of RAM for the
24437 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
24440 The VM shares its store with the host system.
24442 Additional file systems can be shared between the host and the VM using
24443 the @code{--share} and @code{--expose} command-line options: the former
24444 specifies a directory to be shared with write access, while the latter
24445 provides read-only access to the shared directory.
24447 The example below creates a VM in which the user's home directory is
24448 accessible read-only, and where the @file{/exchange} directory is a
24449 read-write mapping of @file{$HOME/tmp} on the host:
24452 guix system vm my-config.scm \
24453 --expose=$HOME --share=$HOME/tmp=/exchange
24456 On GNU/Linux, the default is to boot directly to the kernel; this has
24457 the advantage of requiring only a very tiny root disk image since the
24458 store of the host can then be mounted.
24460 The @code{--full-boot} option forces a complete boot sequence, starting
24461 with the bootloader. This requires more disk space since a root image
24462 containing at least the kernel, initrd, and bootloader data files must
24463 be created. The @code{--image-size} option can be used to specify the
24466 @cindex System images, creation in various formats
24467 @cindex Creating system images in various formats
24470 @itemx docker-image
24471 Return a virtual machine, disk image, or Docker image of the operating
24472 system declared in @var{file} that stands alone. By default,
24473 @command{guix system} estimates the size of the image needed to store
24474 the system, but you can use the @option{--image-size} option to specify
24475 a value. Docker images are built to contain exactly what they need, so
24476 the @option{--image-size} option is ignored in the case of
24477 @code{docker-image}.
24479 You can specify the root file system type by using the
24480 @option{--file-system-type} option. It defaults to @code{ext4}.
24482 When using @code{vm-image}, the returned image is in qcow2 format, which
24483 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
24484 for more information on how to run the image in a virtual machine.
24486 When using @code{disk-image}, a raw disk image is produced; it can be
24487 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
24488 the device corresponding to a USB stick, one can copy the image to it
24489 using the following command:
24492 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
24495 When using @code{docker-image}, a Docker image is produced. Guix builds
24496 the image from scratch, not from a pre-existing Docker base image. As a
24497 result, it contains @emph{exactly} what you define in the operating
24498 system configuration file. You can then load the image and launch a
24499 Docker container using commands like the following:
24502 image_id="$(docker load < guix-system-docker-image.tar.gz)"
24503 docker run -e GUIX_NEW_SYSTEM=/var/guix/profiles/system \\
24504 --entrypoint /var/guix/profiles/system/profile/bin/guile \\
24505 $image_id /var/guix/profiles/system/boot
24508 This command starts a new Docker container from the specified image. It
24509 will boot the Guix system in the usual manner, which means it will
24510 start any services you have defined in the operating system
24511 configuration. Depending on what you run in the Docker container, it
24512 may be necessary to give the container additional permissions. For
24513 example, if you intend to build software using Guix inside of the Docker
24514 container, you may need to pass the @option{--privileged} option to
24518 Return a script to run the operating system declared in @var{file}
24519 within a container. Containers are a set of lightweight isolation
24520 mechanisms provided by the kernel Linux-libre. Containers are
24521 substantially less resource-demanding than full virtual machines since
24522 the kernel, shared objects, and other resources can be shared with the
24523 host system; this also means they provide thinner isolation.
24525 Currently, the script must be run as root in order to support more than
24526 a single user and group. The container shares its store with the host
24529 As with the @code{vm} action (@pxref{guix system vm}), additional file
24530 systems to be shared between the host and container can be specified
24531 using the @option{--share} and @option{--expose} options:
24534 guix system container my-config.scm \
24535 --expose=$HOME --share=$HOME/tmp=/exchange
24539 This option requires Linux-libre 3.19 or newer.
24544 @var{options} can contain any of the common build options (@pxref{Common
24545 Build Options}). In addition, @var{options} can contain one of the
24549 @item --expression=@var{expr}
24550 @itemx -e @var{expr}
24551 Consider the operating-system @var{expr} evaluates to.
24552 This is an alternative to specifying a file which evaluates to an
24554 This is used to generate the Guix system installer @pxref{Building the
24555 Installation Image}).
24557 @item --system=@var{system}
24558 @itemx -s @var{system}
24559 Attempt to build for @var{system} instead of the host system type.
24560 This works as per @command{guix build} (@pxref{Invoking guix build}).
24564 Return the derivation file name of the given operating system without
24567 @item --file-system-type=@var{type}
24568 @itemx -t @var{type}
24569 For the @code{disk-image} action, create a file system of the given
24570 @var{type} on the image.
24572 When this option is omitted, @command{guix system} uses @code{ext4}.
24574 @cindex ISO-9660 format
24575 @cindex CD image format
24576 @cindex DVD image format
24577 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
24578 for burning on CDs and DVDs.
24580 @item --image-size=@var{size}
24581 For the @code{vm-image} and @code{disk-image} actions, create an image
24582 of the given @var{size}. @var{size} may be a number of bytes, or it may
24583 include a unit as a suffix (@pxref{Block size, size specifications,,
24584 coreutils, GNU Coreutils}).
24586 When this option is omitted, @command{guix system} computes an estimate
24587 of the image size as a function of the size of the system declared in
24592 For the @code{container} action, allow containers to access the host network,
24593 that is, do not create a network namespace.
24595 @item --root=@var{file}
24596 @itemx -r @var{file}
24597 Make @var{file} a symlink to the result, and register it as a garbage
24600 @item --skip-checks
24601 Skip pre-installation safety checks.
24603 By default, @command{guix system init} and @command{guix system
24604 reconfigure} perform safety checks: they make sure the file systems that
24605 appear in the @code{operating-system} declaration actually exist
24606 (@pxref{File Systems}), and that any Linux kernel modules that may be
24607 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
24608 RAM Disk}). Passing this option skips these tests altogether.
24611 @cindex on-error strategy
24612 @cindex error strategy
24613 @item --on-error=@var{strategy}
24614 Apply @var{strategy} when an error occurs when reading @var{file}.
24615 @var{strategy} may be one of the following:
24618 @item nothing-special
24619 Report the error concisely and exit. This is the default strategy.
24622 Likewise, but also display a backtrace.
24625 Report the error and enter Guile's debugger. From there, you can run
24626 commands such as @code{,bt} to get a backtrace, @code{,locals} to
24627 display local variable values, and more generally inspect the state of the
24628 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
24629 a list of available debugging commands.
24633 Once you have built, configured, re-configured, and re-re-configured
24634 your Guix installation, you may find it useful to list the operating
24635 system generations available on disk---and that you can choose from the
24636 bootloader boot menu:
24640 @item list-generations
24641 List a summary of each generation of the operating system available on
24642 disk, in a human-readable way. This is similar to the
24643 @option{--list-generations} option of @command{guix package}
24644 (@pxref{Invoking guix package}).
24646 Optionally, one can specify a pattern, with the same syntax that is used
24647 in @command{guix package --list-generations}, to restrict the list of
24648 generations displayed. For instance, the following command displays
24649 generations that are up to 10 days old:
24652 $ guix system list-generations 10d
24657 The @command{guix system} command has even more to offer! The following
24658 sub-commands allow you to visualize how your system services relate to
24661 @anchor{system-extension-graph}
24664 @item extension-graph
24665 Emit in Dot/Graphviz format to standard output the @dfn{service
24666 extension graph} of the operating system defined in @var{file}
24667 (@pxref{Service Composition}, for more information on service
24673 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
24676 produces a PDF file showing the extension relations among services.
24678 @anchor{system-shepherd-graph}
24679 @item shepherd-graph
24680 Emit in Dot/Graphviz format to standard output the @dfn{dependency
24681 graph} of shepherd services of the operating system defined in
24682 @var{file}. @xref{Shepherd Services}, for more information and for an
24687 @node Running Guix in a VM
24688 @section Running Guix in a Virtual Machine
24690 @cindex virtual machine
24691 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
24693 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
24694 This image is a compressed image in QCOW format. You will first need to
24695 decompress with @command{xz -d}, and then you can pass it to an emulator such
24696 as QEMU (see below for details).
24698 This image boots the Xfce graphical environment and it contains some
24699 commonly-used tools. You can install more software in the image by running
24700 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
24701 also reconfigure the system based on its initial configuration file available
24702 as @file{/etc/config.scm} (@pxref{Using the Configuration System}).
24704 Instead of using this pre-built image, one can also build their own virtual
24705 machine image using @command{guix system vm-image} (@pxref{Invoking guix
24706 system}). The returned image is in qcow2 format, which the
24707 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
24710 If you built your own image, you must copy it out of the store
24711 (@pxref{The Store}) and give yourself permission to write to the copy
24712 before you can use it. When invoking QEMU, you must choose a system
24713 emulator that is suitable for your hardware platform. Here is a minimal
24714 QEMU invocation that will boot the result of @command{guix system
24715 vm-image} on x86_64 hardware:
24718 $ qemu-system-x86_64 \
24719 -net user -net nic,model=virtio \
24720 -enable-kvm -m 512 \
24721 -device virtio-blk,drive=myhd \
24722 -drive if=none,file=/tmp/qemu-image,id=myhd
24725 Here is what each of these options means:
24728 @item qemu-system-x86_64
24729 This specifies the hardware platform to emulate. This should match the
24733 Enable the unprivileged user-mode network stack. The guest OS can
24734 access the host but not vice versa. This is the simplest way to get the
24737 @item -net nic,model=virtio
24738 You must create a network interface of a given model. If you do not
24739 create a NIC, the boot will fail. Assuming your hardware platform is
24740 x86_64, you can get a list of available NIC models by running
24741 @command{qemu-system-x86_64 -net nic,model=help}.
24744 If your system has hardware virtualization extensions, enabling the
24745 virtual machine support (KVM) of the Linux kernel will make things run
24748 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
24750 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
24751 which may be insufficient for some operations.
24753 @item -device virtio-blk,drive=myhd
24754 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
24755 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
24756 better performance than if it were emulating a complete disk drive. See the
24757 QEMU and KVM documentation for more info.
24759 @item -drive if=none,file=/tmp/qemu-image,id=myhd
24760 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
24761 the ``myhd'' drive.
24764 The default @command{run-vm.sh} script that is returned by an invocation of
24765 @command{guix system vm} does not add a @command{-net user} flag by default.
24766 To get network access from within the vm add the @code{(dhcp-client-service)}
24767 to your system definition and start the VM using
24768 @command{`guix system vm config.scm` -net user}. An important caveat of using
24769 @command{-net user} for networking is that @command{ping} will not work, because
24770 it uses the ICMP protocol. You'll have to use a different command to check for
24771 network connectivity, for example @command{guix download}.
24773 @subsection Connecting Through SSH
24777 To enable SSH inside a VM you need to add an SSH server like
24778 @code{openssh-service-type} to your VM (@pxref{Networking Services,
24779 @code{openssh-service-type}}). In addition you need to forward the SSH port,
24780 22 by default, to the host. You can do this with
24783 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
24786 To connect to the VM you can run
24789 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
24792 The @command{-p} tells @command{ssh} the port you want to connect to.
24793 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
24794 every time you modify your @command{config.scm} file and the
24795 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
24796 connection to an unknown host every time you connect.
24798 @subsection Using @command{virt-viewer} with Spice
24800 As an alternative to the default @command{qemu} graphical client you can
24801 use the @command{remote-viewer} from the @command{virt-viewer} package. To
24802 connect pass the @command{-spice port=5930,disable-ticketing} flag to
24803 @command{qemu}. See previous section for further information on how to do this.
24805 Spice also allows you to do some nice stuff like share your clipboard with your
24806 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
24809 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
24810 -chardev spicevmc,name=vdagent,id=vdagent
24811 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
24812 name=com.redhat.spice.0
24815 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
24817 @node Defining Services
24818 @section Defining Services
24820 The previous sections show the available services and how one can combine
24821 them in an @code{operating-system} declaration. But how do we define
24822 them in the first place? And what is a service anyway?
24825 * Service Composition:: The model for composing services.
24826 * Service Types and Services:: Types and services.
24827 * Service Reference:: API reference.
24828 * Shepherd Services:: A particular type of service.
24831 @node Service Composition
24832 @subsection Service Composition
24836 Here we define a @dfn{service} as, broadly, something that extends the
24837 functionality of the operating system. Often a service is a process---a
24838 @dfn{daemon}---started when the system boots: a secure shell server, a
24839 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
24840 whose execution can be triggered by another daemon---e.g., an FTP server
24841 started by @command{inetd} or a D-Bus service activated by
24842 @command{dbus-daemon}. Occasionally, a service does not map to a
24843 daemon. For instance, the ``account'' service collects user accounts
24844 and makes sure they exist when the system runs; the ``udev'' service
24845 collects device management rules and makes them available to the eudev
24846 daemon; the @file{/etc} service populates the @file{/etc} directory
24849 @cindex service extensions
24850 Guix system services are connected by @dfn{extensions}. For instance, the
24851 secure shell service @emph{extends} the Shepherd---the
24852 initialization system, running as PID@tie{}1---by giving it the command
24853 lines to start and stop the secure shell daemon (@pxref{Networking
24854 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
24855 service by passing it its @file{.service} specification, and extends the
24856 udev service by passing it device management rules (@pxref{Desktop
24857 Services, @code{upower-service}}); the Guix daemon service extends the
24858 Shepherd by passing it the command lines to start and stop the daemon,
24859 and extends the account service by passing it a list of required build
24860 user accounts (@pxref{Base Services}).
24862 All in all, services and their ``extends'' relations form a directed
24863 acyclic graph (DAG). If we represent services as boxes and extensions
24864 as arrows, a typical system might provide something like this:
24866 @image{images/service-graph,,5in,Typical service extension graph.}
24868 @cindex system service
24869 At the bottom, we see the @dfn{system service}, which produces the
24870 directory containing everything to run and boot the system, as returned
24871 by the @command{guix system build} command. @xref{Service Reference},
24872 to learn about the other service types shown here.
24873 @xref{system-extension-graph, the @command{guix system extension-graph}
24874 command}, for information on how to generate this representation for a
24875 particular operating system definition.
24877 @cindex service types
24878 Technically, developers can define @dfn{service types} to express these
24879 relations. There can be any number of services of a given type on the
24880 system---for instance, a system running two instances of the GNU secure
24881 shell server (lsh) has two instances of @code{lsh-service-type}, with
24882 different parameters.
24884 The following section describes the programming interface for service
24885 types and services.
24887 @node Service Types and Services
24888 @subsection Service Types and Services
24890 A @dfn{service type} is a node in the DAG described above. Let us start
24891 with a simple example, the service type for the Guix build daemon
24892 (@pxref{Invoking guix-daemon}):
24895 (define guix-service-type
24899 (list (service-extension shepherd-root-service-type guix-shepherd-service)
24900 (service-extension account-service-type guix-accounts)
24901 (service-extension activation-service-type guix-activation)))
24902 (default-value (guix-configuration))))
24906 It defines three things:
24910 A name, whose sole purpose is to make inspection and debugging easier.
24913 A list of @dfn{service extensions}, where each extension designates the
24914 target service type and a procedure that, given the parameters of the
24915 service, returns a list of objects to extend the service of that type.
24917 Every service type has at least one service extension. The only
24918 exception is the @dfn{boot service type}, which is the ultimate service.
24921 Optionally, a default value for instances of this type.
24924 In this example, @code{guix-service-type} extends three services:
24927 @item shepherd-root-service-type
24928 The @code{guix-shepherd-service} procedure defines how the Shepherd
24929 service is extended. Namely, it returns a @code{<shepherd-service>}
24930 object that defines how @command{guix-daemon} is started and stopped
24931 (@pxref{Shepherd Services}).
24933 @item account-service-type
24934 This extension for this service is computed by @code{guix-accounts},
24935 which returns a list of @code{user-group} and @code{user-account}
24936 objects representing the build user accounts (@pxref{Invoking
24939 @item activation-service-type
24940 Here @code{guix-activation} is a procedure that returns a gexp, which is
24941 a code snippet to run at ``activation time''---e.g., when the service is
24945 A service of this type is instantiated like this:
24948 (service guix-service-type
24949 (guix-configuration
24951 (use-substitutes? #f)))
24954 The second argument to the @code{service} form is a value representing
24955 the parameters of this specific service instance.
24956 @xref{guix-configuration-type, @code{guix-configuration}}, for
24957 information about the @code{guix-configuration} data type. When the
24958 value is omitted, the default value specified by
24959 @code{guix-service-type} is used:
24962 (service guix-service-type)
24965 @code{guix-service-type} is quite simple because it extends other
24966 services but is not extensible itself.
24968 @c @subsubsubsection Extensible Service Types
24970 The service type for an @emph{extensible} service looks like this:
24973 (define udev-service-type
24974 (service-type (name 'udev)
24976 (list (service-extension shepherd-root-service-type
24977 udev-shepherd-service)))
24979 (compose concatenate) ;concatenate the list of rules
24980 (extend (lambda (config rules)
24982 (($ <udev-configuration> udev initial-rules)
24983 (udev-configuration
24984 (udev udev) ;the udev package to use
24985 (rules (append initial-rules rules)))))))))
24988 This is the service type for the
24989 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
24990 management daemon}. Compared to the previous example, in addition to an
24991 extension of @code{shepherd-root-service-type}, we see two new fields:
24995 This is the procedure to @dfn{compose} the list of extensions to
24996 services of this type.
24998 Services can extend the udev service by passing it lists of rules; we
24999 compose those extensions simply by concatenating them.
25002 This procedure defines how the value of the service is @dfn{extended} with
25003 the composition of the extensions.
25005 Udev extensions are composed into a list of rules, but the udev service
25006 value is itself a @code{<udev-configuration>} record. So here, we
25007 extend that record by appending the list of rules it contains to the
25008 list of contributed rules.
25011 This is a string giving an overview of the service type. The string can
25012 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
25013 @command{guix system search} command searches these strings and displays
25014 them (@pxref{Invoking guix system}).
25017 There can be only one instance of an extensible service type such as
25018 @code{udev-service-type}. If there were more, the
25019 @code{service-extension} specifications would be ambiguous.
25021 Still here? The next section provides a reference of the programming
25022 interface for services.
25024 @node Service Reference
25025 @subsection Service Reference
25027 We have seen an overview of service types (@pxref{Service Types and
25028 Services}). This section provides a reference on how to manipulate
25029 services and service types. This interface is provided by the
25030 @code{(gnu services)} module.
25032 @deffn {Scheme Procedure} service @var{type} [@var{value}]
25033 Return a new service of @var{type}, a @code{<service-type>} object (see
25034 below.) @var{value} can be any object; it represents the parameters of
25035 this particular service instance.
25037 When @var{value} is omitted, the default value specified by @var{type}
25038 is used; if @var{type} does not specify a default value, an error is
25041 For instance, this:
25044 (service openssh-service-type)
25048 is equivalent to this:
25051 (service openssh-service-type
25052 (openssh-configuration))
25055 In both cases the result is an instance of @code{openssh-service-type}
25056 with the default configuration.
25059 @deffn {Scheme Procedure} service? @var{obj}
25060 Return true if @var{obj} is a service.
25063 @deffn {Scheme Procedure} service-kind @var{service}
25064 Return the type of @var{service}---i.e., a @code{<service-type>} object.
25067 @deffn {Scheme Procedure} service-value @var{service}
25068 Return the value associated with @var{service}. It represents its
25072 Here is an example of how a service is created and manipulated:
25076 (service nginx-service-type
25077 (nginx-configuration
25079 (log-directory log-directory)
25080 (run-directory run-directory)
25081 (file config-file))))
25086 (eq? (service-kind s) nginx-service-type)
25090 The @code{modify-services} form provides a handy way to change the
25091 parameters of some of the services of a list such as
25092 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
25093 evaluates to a list of services. Of course, you could always use
25094 standard list combinators such as @code{map} and @code{fold} to do that
25095 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
25096 @code{modify-services} simply provides a more concise form for this
25099 @deffn {Scheme Syntax} modify-services @var{services} @
25100 (@var{type} @var{variable} => @var{body}) @dots{}
25102 Modify the services listed in @var{services} according to the given
25103 clauses. Each clause has the form:
25106 (@var{type} @var{variable} => @var{body})
25109 where @var{type} is a service type---e.g.,
25110 @code{guix-service-type}---and @var{variable} is an identifier that is
25111 bound within the @var{body} to the service parameters---e.g., a
25112 @code{guix-configuration} instance---of the original service of that
25115 The @var{body} should evaluate to the new service parameters, which will
25116 be used to configure the new service. This new service will replace the
25117 original in the resulting list. Because a service's service parameters
25118 are created using @code{define-record-type*}, you can write a succinct
25119 @var{body} that evaluates to the new service parameters by using the
25120 @code{inherit} feature that @code{define-record-type*} provides.
25122 @xref{Using the Configuration System}, for example usage.
25126 Next comes the programming interface for service types. This is
25127 something you want to know when writing new service definitions, but not
25128 necessarily when simply looking for ways to customize your
25129 @code{operating-system} declaration.
25131 @deftp {Data Type} service-type
25132 @cindex service type
25133 This is the representation of a @dfn{service type} (@pxref{Service Types
25138 This is a symbol, used only to simplify inspection and debugging.
25140 @item @code{extensions}
25141 A non-empty list of @code{<service-extension>} objects (see below).
25143 @item @code{compose} (default: @code{#f})
25144 If this is @code{#f}, then the service type denotes services that cannot
25145 be extended---i.e., services that do not receive ``values'' from other
25148 Otherwise, it must be a one-argument procedure. The procedure is called
25149 by @code{fold-services} and is passed a list of values collected from
25150 extensions. It may return any single value.
25152 @item @code{extend} (default: @code{#f})
25153 If this is @code{#f}, services of this type cannot be extended.
25155 Otherwise, it must be a two-argument procedure: @code{fold-services}
25156 calls it, passing it the initial value of the service as the first
25157 argument and the result of applying @code{compose} to the extension
25158 values as the second argument. It must return a value that is a valid
25159 parameter value for the service instance.
25162 @xref{Service Types and Services}, for examples.
25165 @deffn {Scheme Procedure} service-extension @var{target-type} @
25167 Return a new extension for services of type @var{target-type}.
25168 @var{compute} must be a one-argument procedure: @code{fold-services}
25169 calls it, passing it the value associated with the service that provides
25170 the extension; it must return a valid value for the target service.
25173 @deffn {Scheme Procedure} service-extension? @var{obj}
25174 Return true if @var{obj} is a service extension.
25177 Occasionally, you might want to simply extend an existing service. This
25178 involves creating a new service type and specifying the extension of
25179 interest, which can be verbose; the @code{simple-service} procedure
25180 provides a shorthand for this.
25182 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
25183 Return a service that extends @var{target} with @var{value}. This works
25184 by creating a singleton service type @var{name}, of which the returned
25185 service is an instance.
25187 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
25191 (simple-service 'my-mcron-job mcron-service-type
25192 #~(job '(next-hour (3)) "guix gc -F 2G"))
25196 At the core of the service abstraction lies the @code{fold-services}
25197 procedure, which is responsible for ``compiling'' a list of services
25198 down to a single directory that contains everything needed to boot and
25199 run the system---the directory shown by the @command{guix system build}
25200 command (@pxref{Invoking guix system}). In essence, it propagates
25201 service extensions down the service graph, updating each node parameters
25202 on the way, until it reaches the root node.
25204 @deffn {Scheme Procedure} fold-services @var{services} @
25205 [#:target-type @var{system-service-type}]
25206 Fold @var{services} by propagating their extensions down to the root of
25207 type @var{target-type}; return the root service adjusted accordingly.
25210 Lastly, the @code{(gnu services)} module also defines several essential
25211 service types, some of which are listed below.
25213 @defvr {Scheme Variable} system-service-type
25214 This is the root of the service graph. It produces the system directory
25215 as returned by the @command{guix system build} command.
25218 @defvr {Scheme Variable} boot-service-type
25219 The type of the ``boot service'', which produces the @dfn{boot script}.
25220 The boot script is what the initial RAM disk runs when booting.
25223 @defvr {Scheme Variable} etc-service-type
25224 The type of the @file{/etc} service. This service is used to create
25225 files under @file{/etc} and can be extended by
25226 passing it name/file tuples such as:
25229 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
25232 In this example, the effect would be to add an @file{/etc/issue} file
25233 pointing to the given file.
25236 @defvr {Scheme Variable} setuid-program-service-type
25237 Type for the ``setuid-program service''. This service collects lists of
25238 executable file names, passed as gexps, and adds them to the set of
25239 setuid-root programs on the system (@pxref{Setuid Programs}).
25242 @defvr {Scheme Variable} profile-service-type
25243 Type of the service that populates the @dfn{system profile}---i.e., the
25244 programs under @file{/run/current-system/profile}. Other services can
25245 extend it by passing it lists of packages to add to the system profile.
25249 @node Shepherd Services
25250 @subsection Shepherd Services
25252 @cindex shepherd services
25254 @cindex init system
25255 The @code{(gnu services shepherd)} module provides a way to define
25256 services managed by the GNU@tie{}Shepherd, which is the
25257 initialization system---the first process that is started when the
25258 system boots, also known as PID@tie{}1
25259 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
25261 Services in the Shepherd can depend on each other. For instance, the
25262 SSH daemon may need to be started after the syslog daemon has been
25263 started, which in turn can only happen once all the file systems have
25264 been mounted. The simple operating system defined earlier (@pxref{Using
25265 the Configuration System}) results in a service graph like this:
25267 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
25269 You can actually generate such a graph for any operating system
25270 definition using the @command{guix system shepherd-graph} command
25271 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
25273 The @code{%shepherd-root-service} is a service object representing
25274 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
25275 by passing it lists of @code{<shepherd-service>} objects.
25277 @deftp {Data Type} shepherd-service
25278 The data type representing a service managed by the Shepherd.
25281 @item @code{provision}
25282 This is a list of symbols denoting what the service provides.
25284 These are the names that may be passed to @command{herd start},
25285 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
25286 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
25287 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
25289 @item @code{requirement} (default: @code{'()})
25290 List of symbols denoting the Shepherd services this one depends on.
25292 @cindex one-shot services, for the Shepherd
25293 @item @code{one-shot?} (default: @code{#f})
25294 Whether this service is @dfn{one-shot}. One-shot services stop immediately
25295 after their @code{start} action has completed. @xref{Slots of services,,,
25296 shepherd, The GNU Shepherd Manual}, for more info.
25298 @item @code{respawn?} (default: @code{#t})
25299 Whether to restart the service when it stops, for instance when the
25300 underlying process dies.
25303 @itemx @code{stop} (default: @code{#~(const #f)})
25304 The @code{start} and @code{stop} fields refer to the Shepherd's
25305 facilities to start and stop processes (@pxref{Service De- and
25306 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
25307 G-expressions that get expanded in the Shepherd configuration file
25308 (@pxref{G-Expressions}).
25310 @item @code{actions} (default: @code{'()})
25311 @cindex actions, of Shepherd services
25312 This is a list of @code{shepherd-action} objects (see below) defining
25313 @dfn{actions} supported by the service, in addition to the standard
25314 @code{start} and @code{stop} actions. Actions listed here become available as
25315 @command{herd} sub-commands:
25318 herd @var{action} @var{service} [@var{arguments}@dots{}]
25321 @item @code{auto-start?} (default: @code{#t})
25322 Whether this service should be started automatically by the Shepherd. If it
25323 is @code{#f} the service has to be started manually with @code{herd start}.
25325 @item @code{documentation}
25326 A documentation string, as shown when running:
25329 herd doc @var{service-name}
25332 where @var{service-name} is one of the symbols in @code{provision}
25333 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
25335 @item @code{modules} (default: @code{%default-modules})
25336 This is the list of modules that must be in scope when @code{start} and
25337 @code{stop} are evaluated.
25342 @deftp {Data Type} shepherd-action
25343 This is the data type that defines additional actions implemented by a
25344 Shepherd service (see above).
25348 Symbol naming the action.
25350 @item documentation
25351 This is a documentation string for the action. It can be viewed by running:
25354 herd doc @var{service} action @var{action}
25358 This should be a gexp that evaluates to a procedure of at least one argument,
25359 which is the ``running value'' of the service (@pxref{Slots of services,,,
25360 shepherd, The GNU Shepherd Manual}).
25363 The following example defines an action called @code{say-hello} that kindly
25369 (documentation "Say hi!")
25370 (procedure #~(lambda (running . args)
25371 (format #t "Hello, friend! arguments: ~s\n"
25376 Assuming this action is added to the @code{example} service, then you can do:
25379 # herd say-hello example
25380 Hello, friend! arguments: ()
25381 # herd say-hello example a b c
25382 Hello, friend! arguments: ("a" "b" "c")
25385 This, as you can see, is a fairly sophisticated way to say hello.
25386 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
25390 @defvr {Scheme Variable} shepherd-root-service-type
25391 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
25393 This is the service type that extensions target when they want to create
25394 shepherd services (@pxref{Service Types and Services}, for an example).
25395 Each extension must pass a list of @code{<shepherd-service>}.
25398 @defvr {Scheme Variable} %shepherd-root-service
25399 This service represents PID@tie{}1.
25403 @node Documentation
25404 @chapter Documentation
25406 @cindex documentation, searching for
25407 @cindex searching for documentation
25408 @cindex Info, documentation format
25410 @cindex manual pages
25411 In most cases packages installed with Guix come with documentation.
25412 There are two main documentation formats: ``Info'', a browseable
25413 hypertext format used for GNU software, and ``manual pages'' (or ``man
25414 pages''), the linear documentation format traditionally found on Unix.
25415 Info manuals are accessed with the @command{info} command or with Emacs,
25416 and man pages are accessed using @command{man}.
25418 You can look for documentation of software installed on your system by
25419 keyword. For example, the following command searches for information
25420 about ``TLS'' in Info manuals:
25424 "(emacs)Network Security" -- STARTTLS
25425 "(emacs)Network Security" -- TLS
25426 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
25427 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
25432 The command below searches for the same keyword in man pages:
25436 SSL (7) - OpenSSL SSL/TLS library
25437 certtool (1) - GnuTLS certificate tool
25441 These searches are purely local to your computer so you have the
25442 guarantee that documentation you find corresponds to what you have
25443 actually installed, you can access it off-line, and your privacy is
25446 Once you have these results, you can view the relevant documentation by
25450 $ info "(gnutls)Core TLS API"
25460 Info manuals contain sections and indices as well as hyperlinks like
25461 those found in Web pages. The @command{info} reader (@pxref{Top, Info
25462 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
25463 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
25464 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
25465 Introduction}, for an introduction to Info navigation.
25467 @node Installing Debugging Files
25468 @chapter Installing Debugging Files
25470 @cindex debugging files
25471 Program binaries, as produced by the GCC compilers for instance, are
25472 typically written in the ELF format, with a section containing
25473 @dfn{debugging information}. Debugging information is what allows the
25474 debugger, GDB, to map binary code to source code; it is required to
25475 debug a compiled program in good conditions.
25477 The problem with debugging information is that is takes up a fair amount
25478 of disk space. For example, debugging information for the GNU C Library
25479 weighs in at more than 60 MiB. Thus, as a user, keeping all the
25480 debugging info of all the installed programs is usually not an option.
25481 Yet, space savings should not come at the cost of an impediment to
25482 debugging---especially in the GNU system, which should make it easier
25483 for users to exert their computing freedom (@pxref{GNU Distribution}).
25485 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
25486 mechanism that allows users to get the best of both worlds: debugging
25487 information can be stripped from the binaries and stored in separate
25488 files. GDB is then able to load debugging information from those files,
25489 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
25492 The GNU distribution takes advantage of this by storing debugging
25493 information in the @code{lib/debug} sub-directory of a separate package
25494 output unimaginatively called @code{debug} (@pxref{Packages with
25495 Multiple Outputs}). Users can choose to install the @code{debug} output
25496 of a package when they need it. For instance, the following command
25497 installs the debugging information for the GNU C Library and for GNU
25501 guix install glibc:debug guile:debug
25504 GDB must then be told to look for debug files in the user's profile, by
25505 setting the @code{debug-file-directory} variable (consider setting it
25506 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
25510 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
25513 From there on, GDB will pick up debugging information from the
25514 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
25516 In addition, you will most likely want GDB to be able to show the source
25517 code being debugged. To do that, you will have to unpack the source
25518 code of the package of interest (obtained with @code{guix build
25519 --source}, @pxref{Invoking guix build}), and to point GDB to that source
25520 directory using the @code{directory} command (@pxref{Source Path,
25521 @code{directory},, gdb, Debugging with GDB}).
25523 @c XXX: keep me up-to-date
25524 The @code{debug} output mechanism in Guix is implemented by the
25525 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
25526 opt-in---debugging information is available only for the packages
25527 with definitions explicitly declaring a @code{debug} output. This may be
25528 changed to opt-out in the future if our build farm servers can handle
25529 the load. To check whether a package has a @code{debug} output, use
25530 @command{guix package --list-available} (@pxref{Invoking guix package}).
25533 @node Security Updates
25534 @chapter Security Updates
25536 @cindex security updates
25537 @cindex security vulnerabilities
25538 Occasionally, important security vulnerabilities are discovered in software
25539 packages and must be patched. Guix developers try hard to keep track of
25540 known vulnerabilities and to apply fixes as soon as possible in the
25541 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
25542 containing only security updates.) The @command{guix lint} tool helps
25543 developers find out about vulnerable versions of software packages in the
25548 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
25549 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
25550 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
25554 @xref{Invoking guix lint}, for more information.
25557 As of version @value{VERSION}, the feature described below is considered
25561 Guix follows a functional
25562 package management discipline (@pxref{Introduction}), which implies
25563 that, when a package is changed, @emph{every package that depends on it}
25564 must be rebuilt. This can significantly slow down the deployment of
25565 fixes in core packages such as libc or Bash, since basically the whole
25566 distribution would need to be rebuilt. Using pre-built binaries helps
25567 (@pxref{Substitutes}), but deployment may still take more time than
25571 To address this, Guix implements @dfn{grafts}, a mechanism that allows
25572 for fast deployment of critical updates without the costs associated
25573 with a whole-distribution rebuild. The idea is to rebuild only the
25574 package that needs to be patched, and then to ``graft'' it onto packages
25575 explicitly installed by the user and that were previously referring to
25576 the original package. The cost of grafting is typically very low, and
25577 order of magnitudes lower than a full rebuild of the dependency chain.
25579 @cindex replacements of packages, for grafts
25580 For instance, suppose a security update needs to be applied to Bash.
25581 Guix developers will provide a package definition for the ``fixed''
25582 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
25583 Packages}). Then, the original package definition is augmented with a
25584 @code{replacement} field pointing to the package containing the bug fix:
25591 (replacement bash-fixed)))
25594 From there on, any package depending directly or indirectly on Bash---as
25595 reported by @command{guix gc --requisites} (@pxref{Invoking guix
25596 gc})---that is installed is automatically ``rewritten'' to refer to
25597 @code{bash-fixed} instead of @code{bash}. This grafting process takes
25598 time proportional to the size of the package, usually less than a
25599 minute for an ``average'' package on a recent machine. Grafting is
25600 recursive: when an indirect dependency requires grafting, then grafting
25601 ``propagates'' up to the package that the user is installing.
25603 Currently, the length of the name and version of the graft and that of
25604 the package it replaces (@code{bash-fixed} and @code{bash} in the example
25605 above) must be equal. This restriction mostly comes from the fact that
25606 grafting works by patching files, including binary files, directly.
25607 Other restrictions may apply: for instance, when adding a graft to a
25608 package providing a shared library, the original shared library and its
25609 replacement must have the same @code{SONAME} and be binary-compatible.
25611 The @option{--no-grafts} command-line option allows you to forcefully
25612 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
25616 guix build bash --no-grafts
25620 returns the store file name of the original Bash, whereas:
25627 returns the store file name of the ``fixed'', replacement Bash. This
25628 allows you to distinguish between the two variants of Bash.
25630 To verify which Bash your whole profile refers to, you can run
25631 (@pxref{Invoking guix gc}):
25634 guix gc -R `readlink -f ~/.guix-profile` | grep bash
25638 @dots{} and compare the store file names that you get with those above.
25639 Likewise for a complete Guix system generation:
25642 guix gc -R `guix system build my-config.scm` | grep bash
25645 Lastly, to check which Bash running processes are using, you can use the
25646 @command{lsof} command:
25649 lsof | grep /gnu/store/.*bash
25653 @node Bootstrapping
25654 @chapter Bootstrapping
25656 @c Adapted from the ELS 2013 paper.
25658 @cindex bootstrapping
25660 Bootstrapping in our context refers to how the distribution gets built
25661 ``from nothing''. Remember that the build environment of a derivation
25662 contains nothing but its declared inputs (@pxref{Introduction}). So
25663 there's an obvious chicken-and-egg problem: how does the first package
25664 get built? How does the first compiler get compiled? Note that this is
25665 a question of interest only to the curious hacker, not to the regular
25666 user, so you can shamelessly skip this section if you consider yourself
25667 a ``regular user''.
25669 @cindex bootstrap binaries
25670 The GNU system is primarily made of C code, with libc at its core. The
25671 GNU build system itself assumes the availability of a Bourne shell and
25672 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
25673 `grep'. Furthermore, build programs---programs that run
25674 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
25675 (@pxref{Derivations}). Consequently, to be able to build anything at
25676 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
25677 Binutils, libc, and the other packages mentioned above---the
25678 @dfn{bootstrap binaries}.
25680 These bootstrap binaries are ``taken for granted'', though we can also
25681 re-create them if needed (more on that later).
25683 @unnumberedsec Preparing to Use the Bootstrap Binaries
25685 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
25686 @c large image, it's hard to scroll. Oh well.
25687 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
25689 The figure above shows the very beginning of the dependency graph of the
25690 distribution, corresponding to the package definitions of the @code{(gnu
25691 packages bootstrap)} module. A similar figure can be generated with
25692 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
25695 guix graph -t derivation \
25696 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
25700 At this level of detail, things are
25701 slightly complex. First, Guile itself consists of an ELF executable,
25702 along with many source and compiled Scheme files that are dynamically
25703 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
25704 tarball shown in this graph. This tarball is part of Guix's ``source''
25705 distribution, and gets inserted into the store with @code{add-to-store}
25706 (@pxref{The Store}).
25708 But how do we write a derivation that unpacks this tarball and adds it
25709 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
25710 derivation---the first one that gets built---uses @code{bash} as its
25711 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
25712 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
25713 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
25714 the Guix source distribution, whose sole purpose is to allow the Guile
25715 tarball to be unpacked.
25717 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
25718 Guile that can be used to run subsequent build programs. Its first task
25719 is to download tarballs containing the other pre-built binaries---this
25720 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
25721 @code{ftp-client.scm} are used for this purpose. The
25722 @code{module-import.drv} derivations import those modules in a directory
25723 in the store, using the original layout. The
25724 @code{module-import-compiled.drv} derivations compile those modules, and
25725 write them in an output directory with the right layout. This
25726 corresponds to the @code{#:modules} argument of
25727 @code{build-expression->derivation} (@pxref{Derivations}).
25729 Finally, the various tarballs are unpacked by the
25730 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
25731 etc., at which point we have a working C tool chain.
25734 @unnumberedsec Building the Build Tools
25736 Bootstrapping is complete when we have a full tool chain that does not
25737 depend on the pre-built bootstrap tools discussed above. This
25738 no-dependency requirement is verified by checking whether the files of
25739 the final tool chain contain references to the @file{/gnu/store}
25740 directories of the bootstrap inputs. The process that leads to this
25741 ``final'' tool chain is described by the package definitions found in
25742 the @code{(gnu packages commencement)} module.
25744 The @command{guix graph} command allows us to ``zoom out'' compared to
25745 the graph above, by looking at the level of package objects instead of
25746 individual derivations---remember that a package may translate to
25747 several derivations, typically one derivation to download its source,
25748 one to build the Guile modules it needs, and one to actually build the
25749 package from source. The command:
25752 guix graph -t bag \
25753 -e '(@@@@ (gnu packages commencement)
25754 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
25758 produces the dependency graph leading to the ``final'' C
25759 library@footnote{You may notice the @code{glibc-intermediate} label,
25760 suggesting that it is not @emph{quite} final, but as a good
25761 approximation, we will consider it final.}, depicted below.
25763 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
25765 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
25766 The first tool that gets built with the bootstrap binaries is
25767 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
25768 for all the following packages. From there Findutils and Diffutils get
25771 Then come the first-stage Binutils and GCC, built as pseudo cross
25772 tools---i.e., with @code{--target} equal to @code{--host}. They are
25773 used to build libc. Thanks to this cross-build trick, this libc is
25774 guaranteed not to hold any reference to the initial tool chain.
25776 From there the final Binutils and GCC (not shown above) are built.
25778 from the final Binutils, and links programs against the just-built libc.
25779 This tool chain is used to build the other packages used by Guix and by
25780 the GNU Build System: Guile, Bash, Coreutils, etc.
25782 And voilà! At this point we have the complete set of build tools that
25783 the GNU Build System expects. These are in the @code{%final-inputs}
25784 variable of the @code{(gnu packages commencement)} module, and are
25785 implicitly used by any package that uses @code{gnu-build-system}
25786 (@pxref{Build Systems, @code{gnu-build-system}}).
25789 @unnumberedsec Building the Bootstrap Binaries
25791 @cindex bootstrap binaries
25792 Because the final tool chain does not depend on the bootstrap binaries,
25793 those rarely need to be updated. Nevertheless, it is useful to have an
25794 automated way to produce them, should an update occur, and this is what
25795 the @code{(gnu packages make-bootstrap)} module provides.
25797 The following command builds the tarballs containing the bootstrap
25798 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
25799 of Coreutils and other basic command-line tools):
25802 guix build bootstrap-tarballs
25805 The generated tarballs are those that should be referred to in the
25806 @code{(gnu packages bootstrap)} module mentioned at the beginning of
25809 Still here? Then perhaps by now you've started to wonder: when do we
25810 reach a fixed point? That is an interesting question! The answer is
25811 unknown, but if you would like to investigate further (and have
25812 significant computational and storage resources to do so), then let us
25815 @unnumberedsec Reducing the Set of Bootstrap Binaries
25817 Our bootstrap binaries currently include GCC, Guile, etc. That's a lot
25818 of binary code! Why is that a problem? It's a problem because these
25819 big chunks of binary code are practically non-auditable, which makes it
25820 hard to establish what source code produced them. Every unauditable
25821 binary also leaves us vulnerable to compiler backdoors as described by
25822 Ken Thompson in the 1984 paper @emph{Reflections on Trusting Trust}.
25824 This is mitigated by the fact that our bootstrap binaries were generated
25825 from an earlier Guix revision. Nevertheless it lacks the level of
25826 transparency that we get in the rest of the package dependency graph,
25827 where Guix always gives us a source-to-binary mapping. Thus, our goal
25828 is to reduce the set of bootstrap binaries to the bare minimum.
25830 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
25831 on-going projects to do that. One of these is about replacing the
25832 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
25833 of increasing complexity, which could be built from source starting from
25834 a simple and auditable assembler. Your help is welcome!
25838 @chapter Porting to a New Platform
25840 As discussed above, the GNU distribution is self-contained, and
25841 self-containment is achieved by relying on pre-built ``bootstrap
25842 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
25843 operating system kernel, CPU architecture, and application binary
25844 interface (ABI). Thus, to port the distribution to a platform that is
25845 not yet supported, one must build those bootstrap binaries, and update
25846 the @code{(gnu packages bootstrap)} module to use them on that platform.
25848 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
25849 When everything goes well, and assuming the GNU tool chain supports the
25850 target platform, this can be as simple as running a command like this
25854 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
25857 For this to work, the @code{glibc-dynamic-linker} procedure in
25858 @code{(gnu packages bootstrap)} must be augmented to return the right
25859 file name for libc's dynamic linker on that platform; likewise,
25860 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
25861 taught about the new platform.
25863 Once these are built, the @code{(gnu packages bootstrap)} module needs
25864 to be updated to refer to these binaries on the target platform. That
25865 is, the hashes and URLs of the bootstrap tarballs for the new platform
25866 must be added alongside those of the currently supported platforms. The
25867 bootstrap Guile tarball is treated specially: it is expected to be
25868 available locally, and @file{gnu/local.mk} has rules to download it for
25869 the supported architectures; a rule for the new platform must be added
25872 In practice, there may be some complications. First, it may be that the
25873 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
25874 above) is not recognized by all the GNU tools. Typically, glibc
25875 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
25876 configure flag (see @code{gcc.scm} for examples of how to handle this).
25877 Second, some of the required packages could fail to build for that
25878 platform. Lastly, the generated binaries could be broken for some
25881 @c *********************************************************************
25882 @include contributing.texi
25884 @c *********************************************************************
25885 @node Acknowledgments
25886 @chapter Acknowledgments
25888 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
25889 which was designed and
25890 implemented by Eelco Dolstra, with contributions from other people (see
25891 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
25892 management, and promoted unprecedented features, such as transactional
25893 package upgrades and rollbacks, per-user profiles, and referentially
25894 transparent build processes. Without this work, Guix would not exist.
25896 The Nix-based software distributions, Nixpkgs and NixOS, have also been
25897 an inspiration for Guix.
25899 GNU@tie{}Guix itself is a collective work with contributions from a
25900 number of people. See the @file{AUTHORS} file in Guix for more
25901 information on these fine people. The @file{THANKS} file lists people
25902 who have helped by reporting bugs, taking care of the infrastructure,
25903 providing artwork and themes, making suggestions, and more---thank you!
25906 @c *********************************************************************
25907 @node GNU Free Documentation License
25908 @appendix GNU Free Documentation License
25909 @cindex license, GNU Free Documentation License
25910 @include fdl-1.3.texi
25912 @c *********************************************************************
25913 @node Concept Index
25914 @unnumbered Concept Index
25917 @node Programming Index
25918 @unnumbered Programming Index
25919 @syncodeindex tp fn
25920 @syncodeindex vr fn
25925 @c Local Variables:
25926 @c ispell-local-dictionary: "american";