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.info
21 @set SUBSTITUTE-URL https://@value{SUBSTITUTE-SERVER}
24 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 Ludovic Courtès@*
25 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
26 Copyright @copyright{} 2013 Nikita Karetnikov@*
27 Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
28 Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
29 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
30 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
31 Copyright @copyright{} 2015, 2016, 2017 Leo Famulari@*
32 Copyright @copyright{} 2015, 2016, 2017, 2018, 2019 Ricardo Wurmus@*
33 Copyright @copyright{} 2016 Ben Woodcroft@*
34 Copyright @copyright{} 2016, 2017, 2018 Chris Marusich@*
35 Copyright @copyright{} 2016, 2017, 2018, 2019 Efraim Flashner@*
36 Copyright @copyright{} 2016 John Darrington@*
37 Copyright @copyright{} 2016, 2017 ng0@*
38 Copyright @copyright{} 2016, 2017, 2018, 2019 Jan Nieuwenhuizen@*
39 Copyright @copyright{} 2016 Julien Lepiller@*
40 Copyright @copyright{} 2016 Alex ter Weele@*
41 Copyright @copyright{} 2016, 2017, 2018, 2019 Christopher Baines@*
42 Copyright @copyright{} 2017, 2018 Clément Lassieur@*
43 Copyright @copyright{} 2017, 2018 Mathieu Othacehe@*
44 Copyright @copyright{} 2017 Federico Beffa@*
45 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
46 Copyright @copyright{} 2017 Thomas Danckaert@*
47 Copyright @copyright{} 2017 humanitiesNerd@*
48 Copyright @copyright{} 2017 Christopher Allan Webber@*
49 Copyright @copyright{} 2017, 2018 Marius Bakke@*
50 Copyright @copyright{} 2017 Hartmut Goebel@*
51 Copyright @copyright{} 2017 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018 Tobias Geerinckx-Rice@*
53 Copyright @copyright{} 2017 George Clemmer@*
54 Copyright @copyright{} 2017 Andy Wingo@*
55 Copyright @copyright{} 2017, 2018, 2019 Arun Isaac@*
56 Copyright @copyright{} 2017 nee@*
57 Copyright @copyright{} 2018 Rutger Helling@*
58 Copyright @copyright{} 2018 Oleg Pykhalov@*
59 Copyright @copyright{} 2018 Mike Gerwitz@*
60 Copyright @copyright{} 2018 Pierre-Antoine Rouby@*
61 Copyright @copyright{} 2018 Gábor Boskovits@*
62 Copyright @copyright{} 2018 Florian Pelz@*
63 Copyright @copyright{} 2018 Laura Lazzati@*
64 Copyright @copyright{} 2018 Alex Vong@*
66 Permission is granted to copy, distribute and/or modify this document
67 under the terms of the GNU Free Documentation License, Version 1.3 or
68 any later version published by the Free Software Foundation; with no
69 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
70 copy of the license is included in the section entitled ``GNU Free
71 Documentation License''.
74 @dircategory System administration
76 * Guix: (guix). Manage installed software and system configuration.
77 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
78 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
79 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
80 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
83 @dircategory Software development
85 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
86 * guix build: (guix)Invoking guix build. Building packages.
87 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
91 @title GNU Guix Reference Manual
92 @subtitle Using the GNU Guix Functional Package Manager
93 @author The GNU Guix Developers
96 @vskip 0pt plus 1filll
97 Edition @value{EDITION} @*
105 @c *********************************************************************
109 This document describes GNU Guix version @value{VERSION}, a functional
110 package management tool written for the GNU system.
112 @c TRANSLATORS: You can replace the following paragraph with information on
113 @c how to join your own translation team and how to report issues with the
115 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
116 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
117 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}), and
118 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}). If you
119 would like to translate it in your native language, consider joining the
120 @uref{https://translationproject.org/domain/guix-manual.html, Translation
124 * Introduction:: What is Guix about?
125 * Installation:: Installing Guix.
126 * System Installation:: Installing the whole operating system.
127 * Package Management:: Package installation, upgrade, etc.
128 * Development:: Guix-aided software development.
129 * Programming Interface:: Using Guix in Scheme.
130 * Utilities:: Package management commands.
131 * System Configuration:: Configuring the operating system.
132 * Documentation:: Browsing software user manuals.
133 * Installing Debugging Files:: Feeding the debugger.
134 * Security Updates:: Deploying security fixes quickly.
135 * Bootstrapping:: GNU/Linux built from scratch.
136 * Porting:: Targeting another platform or kernel.
137 * Contributing:: Your help needed!
139 * Acknowledgments:: Thanks!
140 * GNU Free Documentation License:: The license of this manual.
141 * Concept Index:: Concepts.
142 * Programming Index:: Data types, functions, and variables.
145 --- The Detailed Node Listing ---
149 * Managing Software the Guix Way:: What's special.
150 * GNU Distribution:: The packages and tools.
154 * Binary Installation:: Getting Guix running in no time!
155 * Requirements:: Software needed to build and run Guix.
156 * Running the Test Suite:: Testing Guix.
157 * Setting Up the Daemon:: Preparing the build daemon's environment.
158 * Invoking guix-daemon:: Running the build daemon.
159 * Application Setup:: Application-specific setup.
161 Setting Up the Daemon
163 * Build Environment Setup:: Preparing the isolated build environment.
164 * Daemon Offload Setup:: Offloading builds to remote machines.
165 * SELinux Support:: Using an SELinux policy for the daemon.
169 * Limitations:: What you can expect.
170 * Hardware Considerations:: Supported hardware.
171 * USB Stick and DVD Installation:: Preparing the installation medium.
172 * Preparing for Installation:: Networking, partitioning, etc.
173 * Guided Graphical Installation:: Easy graphical installation.
174 * Manual Installation:: Manual installation for wizards.
175 * After System Installation:: When installation succeeded.
176 * Installing Guix in a VM:: Guix System playground.
177 * Building the Installation Image:: How this comes to be.
181 * Keyboard Layout and Networking and Partitioning:: Initial setup.
182 * Proceeding with the Installation:: Installing.
186 * Features:: How Guix will make your life brighter.
187 * Invoking guix package:: Package installation, removal, etc.
188 * Substitutes:: Downloading pre-built binaries.
189 * Packages with Multiple Outputs:: Single source package, multiple outputs.
190 * Invoking guix gc:: Running the garbage collector.
191 * Invoking guix pull:: Fetching the latest Guix and distribution.
192 * Channels:: Customizing the package collection.
193 * Inferiors:: Interacting with another revision of Guix.
194 * Invoking guix describe:: Display information about your Guix revision.
195 * Invoking guix archive:: Exporting and importing store files.
199 * Official Substitute Server:: One particular source of substitutes.
200 * Substitute Server Authorization:: How to enable or disable substitutes.
201 * Substitute Authentication:: How Guix verifies substitutes.
202 * Proxy Settings:: How to get substitutes via proxy.
203 * Substitution Failure:: What happens when substitution fails.
204 * On Trusting Binaries:: How can you trust that binary blob?
208 * Invoking guix environment:: Setting up development environments.
209 * Invoking guix pack:: Creating software bundles.
211 Programming Interface
213 * Package Modules:: Packages from the programmer's viewpoint.
214 * Defining Packages:: Defining new packages.
215 * Build Systems:: Specifying how packages are built.
216 * The Store:: Manipulating the package store.
217 * Derivations:: Low-level interface to package derivations.
218 * The Store Monad:: Purely functional interface to the store.
219 * G-Expressions:: Manipulating build expressions.
220 * Invoking guix repl:: Fiddling with Guix interactively.
224 * package Reference:: The package data type.
225 * origin Reference:: The origin data type.
229 * Invoking guix build:: Building packages from the command line.
230 * Invoking guix edit:: Editing package definitions.
231 * Invoking guix download:: Downloading a file and printing its hash.
232 * Invoking guix hash:: Computing the cryptographic hash of a file.
233 * Invoking guix import:: Importing package definitions.
234 * Invoking guix refresh:: Updating package definitions.
235 * Invoking guix lint:: Finding errors in package definitions.
236 * Invoking guix size:: Profiling disk usage.
237 * Invoking guix graph:: Visualizing the graph of packages.
238 * Invoking guix publish:: Sharing substitutes.
239 * Invoking guix challenge:: Challenging substitute servers.
240 * Invoking guix copy:: Copying to and from a remote store.
241 * Invoking guix container:: Process isolation.
242 * Invoking guix weather:: Assessing substitute availability.
243 * Invoking guix processes:: Listing client processes.
245 Invoking @command{guix build}
247 * Common Build Options:: Build options for most commands.
248 * Package Transformation Options:: Creating variants of packages.
249 * Additional Build Options:: Options specific to 'guix build'.
250 * Debugging Build Failures:: Real life packaging experience.
254 * Using the Configuration System:: Customizing your GNU system.
255 * operating-system Reference:: Detail of operating-system declarations.
256 * File Systems:: Configuring file system mounts.
257 * Mapped Devices:: Block device extra processing.
258 * User Accounts:: Specifying user accounts.
259 * Keyboard Layout:: How the system interprets key strokes.
260 * Locales:: Language and cultural convention settings.
261 * Services:: Specifying system services.
262 * Setuid Programs:: Programs running with root privileges.
263 * X.509 Certificates:: Authenticating HTTPS servers.
264 * Name Service Switch:: Configuring libc's name service switch.
265 * Initial RAM Disk:: Linux-Libre bootstrapping.
266 * Bootloader Configuration:: Configuring the boot loader.
267 * Invoking guix system:: Instantiating a system configuration.
268 * Running Guix in a VM:: How to run Guix System in a virtual machine.
269 * Defining Services:: Adding new service definitions.
273 * Base Services:: Essential system services.
274 * Scheduled Job Execution:: The mcron service.
275 * Log Rotation:: The rottlog service.
276 * Networking Services:: Network setup, SSH daemon, etc.
277 * X Window:: Graphical display.
278 * Printing Services:: Local and remote printer support.
279 * Desktop Services:: D-Bus and desktop services.
280 * Sound Services:: ALSA and Pulseaudio services.
281 * Database Services:: SQL databases, key-value stores, etc.
282 * Mail Services:: IMAP, POP3, SMTP, and all that.
283 * Messaging Services:: Messaging services.
284 * Telephony Services:: Telephony services.
285 * Monitoring Services:: Monitoring services.
286 * Kerberos Services:: Kerberos services.
287 * Web Services:: Web servers.
288 * Certificate Services:: TLS certificates via Let's Encrypt.
289 * DNS Services:: DNS daemons.
290 * VPN Services:: VPN daemons.
291 * Network File System:: NFS related services.
292 * Continuous Integration:: The Cuirass service.
293 * Power Management Services:: Extending battery life.
294 * Audio Services:: The MPD.
295 * Virtualization Services:: Virtualization services.
296 * Version Control Services:: Providing remote access to Git repositories.
297 * Game Services:: Game servers.
298 * Miscellaneous Services:: Other services.
302 * Service Composition:: The model for composing services.
303 * Service Types and Services:: Types and services.
304 * Service Reference:: API reference.
305 * Shepherd Services:: A particular type of service.
310 @c *********************************************************************
312 @chapter Introduction
315 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
316 using the international phonetic alphabet (IPA).} is a package
317 management tool for and distribution of the GNU system.
318 Guix makes it easy for unprivileged
319 users to install, upgrade, or remove software packages, to roll back to a
320 previous package set, to build packages from source, and generally
321 assists with the creation and maintenance of software environments.
324 @cindex GuixSD, now Guix System
325 @cindex Guix System Distribution, now Guix System
326 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
327 complements the available tools without interference (@pxref{Installation}),
328 or you can use it as a standalone operating system distribution,
329 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
330 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
331 group everything under the ``Guix'' banner since, after all, Guix System is
332 readily available through the @command{guix system} command, even if you're
333 using a different distro underneath!}. @xref{GNU Distribution}.
336 * Managing Software the Guix Way:: What's special.
337 * GNU Distribution:: The packages and tools.
340 @node Managing Software the Guix Way
341 @section Managing Software the Guix Way
343 @cindex user interfaces
344 Guix provides a command-line package management interface
345 (@pxref{Package Management}), tools to help with software development
346 (@pxref{Development}), command-line utilities for more advanced usage,
347 (@pxref{Utilities}), as well as Scheme programming interfaces
348 (@pxref{Programming Interface}).
350 Its @dfn{build daemon} is responsible for building packages on behalf of
351 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
352 binaries from authorized sources (@pxref{Substitutes}).
354 @cindex extensibility of the distribution
355 @cindex customization, of packages
356 Guix includes package definitions for many GNU and non-GNU packages, all
357 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
358 user's computing freedom}. It is @emph{extensible}: users can write
359 their own package definitions (@pxref{Defining Packages}) and make them
360 available as independent package modules (@pxref{Package Modules}). It
361 is also @emph{customizable}: users can @emph{derive} specialized package
362 definitions from existing ones, including from the command line
363 (@pxref{Package Transformation Options}).
365 @cindex functional package management
367 Under the hood, Guix implements the @dfn{functional package management}
368 discipline pioneered by Nix (@pxref{Acknowledgments}).
369 In Guix, the package build and installation process is seen
370 as a @emph{function}, in the mathematical sense. That function takes inputs,
371 such as build scripts, a compiler, and libraries, and
372 returns an installed package. As a pure function, its result depends
373 solely on its inputs---for instance, it cannot refer to software or
374 scripts that were not explicitly passed as inputs. A build function
375 always produces the same result when passed a given set of inputs. It
376 cannot alter the environment of the running system in
377 any way; for instance, it cannot create, modify, or delete files outside
378 of its build and installation directories. This is achieved by running
379 build processes in isolated environments (or @dfn{containers}), where only their
380 explicit inputs are visible.
383 The result of package build functions is @dfn{cached} in the file
384 system, in a special directory called @dfn{the store} (@pxref{The
385 Store}). Each package is installed in a directory of its own in the
386 store---by default under @file{/gnu/store}. The directory name contains
387 a hash of all the inputs used to build that package; thus, changing an
388 input yields a different directory name.
390 This approach is the foundation for the salient features of Guix: support
391 for transactional package upgrade and rollback, per-user installation, and
392 garbage collection of packages (@pxref{Features}).
395 @node GNU Distribution
396 @section GNU Distribution
399 Guix comes with a distribution of the GNU system consisting entirely of
400 free software@footnote{The term ``free'' here refers to the
401 @url{http://www.gnu.org/philosophy/free-sw.html,freedom provided to
402 users of that software}.}. The
403 distribution can be installed on its own (@pxref{System Installation}),
404 but it is also possible to install Guix as a package manager on top of
405 an installed GNU/Linux system (@pxref{Installation}). When we need to
406 distinguish between the two, we refer to the standalone distribution as
409 The distribution provides core GNU packages such as GNU libc, GCC, and
410 Binutils, as well as many GNU and non-GNU applications. The complete
411 list of available packages can be browsed
412 @url{http://www.gnu.org/software/guix/packages,on-line} or by
413 running @command{guix package} (@pxref{Invoking guix package}):
416 guix package --list-available
419 Our goal is to provide a practical 100% free software distribution of
420 Linux-based and other variants of GNU, with a focus on the promotion and
421 tight integration of GNU components, and an emphasis on programs and
422 tools that help users exert that freedom.
424 Packages are currently available on the following platforms:
429 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
432 Intel 32-bit architecture (IA32), Linux-Libre kernel;
435 ARMv7-A architecture with hard float, Thumb-2 and NEON,
436 using the EABI hard-float application binary interface (ABI),
437 and Linux-Libre kernel.
440 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel. This is
441 currently in an experimental stage, with limited support.
442 @xref{Contributing}, for how to help!
445 little-endian 64-bit MIPS processors, specifically the Loongson series,
446 n32 ABI, and Linux-Libre kernel.
450 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
451 configuration and Guix takes care of instantiating the configuration in a
452 transactional, reproducible, and stateless fashion (@pxref{System
453 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
454 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
455 Manual}), the well-known GNU utilities and tool chain, as well as the
456 graphical environment or system services of your choice.
458 Guix System is available on all the above platforms except
459 @code{mips64el-linux}.
462 For information on porting to other architectures or kernels,
465 Building this distribution is a cooperative effort, and you are invited
466 to join! @xref{Contributing}, for information about how you can help.
469 @c *********************************************************************
471 @chapter Installation
473 @cindex installing Guix
476 We recommend the use of this
477 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
478 shell installer script} to install Guix on top of a running GNU/Linux system,
479 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
480 with the installation of the package manager, which can be done on top of a
481 running GNU/Linux system. If, instead, you want to install the complete GNU
482 operating system, @pxref{System Installation}.} The script automates the
483 download, installation, and initial configuration of Guix. It should be run
487 @cindex foreign distro
488 @cindex directories related to foreign distro
489 When installed on a foreign distro, GNU@tie{}Guix complements the available
490 tools without interference. Its data lives exclusively in two directories,
491 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
492 such as @file{/etc}, are left untouched.
494 Once installed, Guix can be updated by running @command{guix pull}
495 (@pxref{Invoking guix pull}).
497 If you prefer to perform the installation steps manually or want to tweak
498 them, you may find the following subsections useful. They describe the
499 software requirements of Guix, as well as how to install it manually and get
503 * Binary Installation:: Getting Guix running in no time!
504 * Requirements:: Software needed to build and run Guix.
505 * Running the Test Suite:: Testing Guix.
506 * Setting Up the Daemon:: Preparing the build daemon's environment.
507 * Invoking guix-daemon:: Running the build daemon.
508 * Application Setup:: Application-specific setup.
511 @node Binary Installation
512 @section Binary Installation
514 @cindex installing Guix from binaries
515 @cindex installer script
516 This section describes how to install Guix on an arbitrary system from a
517 self-contained tarball providing binaries for Guix and for all its
518 dependencies. This is often quicker than installing from source, which
519 is described in the next sections. The only requirement is to have
522 @c Note duplicated from the ``Installation'' node.
524 We recommend the use of this
525 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
526 shell installer script}. The script automates the download, installation, and
527 initial configuration steps described below. It should be run as the root
531 Installing goes along these lines:
535 @cindex downloading Guix binary
536 Download the binary tarball from
537 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz},
538 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
539 already running the kernel Linux, and so on.
541 @c The following is somewhat duplicated in ``System Installation''.
542 Make sure to download the associated @file{.sig} file and to verify the
543 authenticity of the tarball against it, along these lines:
546 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
547 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
550 If that command fails because you do not have the required public key,
551 then run this command to import it:
554 $ gpg --keyserver @value{KEY-SERVER} \
555 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
559 and rerun the @code{gpg --verify} command.
560 @c end authentication part
563 Now, you need to become the @code{root} user. Depending on your distribution,
564 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
568 # tar --warning=no-timestamp -xf \
569 guix-binary-@value{VERSION}.@var{system}.tar.xz
570 # mv var/guix /var/ && mv gnu /
573 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
574 The latter contains a ready-to-use profile for @code{root} (see next
577 Do @emph{not} unpack the tarball on a working Guix system since that
578 would overwrite its own essential files.
580 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
581 not emit warnings about ``implausibly old time stamps'' (such
582 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
584 They stem from the fact that all the
585 files in the archive have their modification time set to zero (which
586 means January 1st, 1970.) This is done on purpose to make sure the
587 archive content is independent of its creation time, thus making it
591 Make the profile available under @file{~root/.config/guix/current}, which is
592 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
595 # mkdir -p ~root/.config/guix
596 # ln -sf /var/guix/profiles/per-user/root/current-guix \
597 ~root/.config/guix/current
600 Source @file{etc/profile} to augment @code{PATH} and other relevant
601 environment variables:
604 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
605 source $GUIX_PROFILE/etc/profile
609 Create the group and user accounts for build users as explained below
610 (@pxref{Build Environment Setup}).
613 Run the daemon, and set it to automatically start on boot.
615 If your host distro uses the systemd init system, this can be achieved
618 @c Versions of systemd that supported symlinked service files are not
619 @c yet widely deployed, so we should suggest that users copy the service
622 @c See this thread for more information:
623 @c http://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
626 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
628 # systemctl start guix-daemon && systemctl enable guix-daemon
631 If your host distro uses the Upstart init system:
634 # initctl reload-configuration
635 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
640 Otherwise, you can still start the daemon manually with:
643 # ~root/.config/guix/current/bin/guix-daemon \
644 --build-users-group=guixbuild
648 Make the @command{guix} command available to other users on the machine,
652 # mkdir -p /usr/local/bin
654 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
657 It is also a good idea to make the Info version of this manual available
661 # mkdir -p /usr/local/share/info
662 # cd /usr/local/share/info
663 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
667 That way, assuming @file{/usr/local/share/info} is in the search path,
668 running @command{info guix} will open this manual (@pxref{Other Info
669 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
673 @cindex substitutes, authorization thereof
674 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
675 (@pxref{Substitutes}), authorize them:
678 # guix archive --authorize < \
679 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
683 Each user may need to perform a few additional steps to make their Guix
684 environment ready for use, @pxref{Application Setup}.
687 Voilà, the installation is complete!
689 You can confirm that Guix is working by installing a sample package into
696 The binary installation tarball can be (re)produced and verified simply
697 by running the following command in the Guix source tree:
700 make guix-binary.@var{system}.tar.xz
704 ...@: which, in turn, runs:
707 guix pack -s @var{system} --localstatedir \
708 --profile-name=current-guix guix
711 @xref{Invoking guix pack}, for more info on this handy tool.
714 @section Requirements
716 This section lists requirements when building Guix from source. The
717 build procedure for Guix is the same as for other GNU software, and is
718 not covered here. Please see the files @file{README} and @file{INSTALL}
719 in the Guix source tree for additional details.
721 @cindex official website
722 GNU Guix is available for download from its website at
723 @url{https://www.gnu.org/software/guix/}.
725 GNU Guix depends on the following packages:
728 @item @url{http://gnu.org/software/guile/, GNU Guile}, version 2.2.x;
729 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
732 @uref{http://gnutls.org/, GnuTLS}, specifically its Guile bindings
733 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
734 Guile,, gnutls-guile, GnuTLS-Guile});
736 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
739 @c FIXME: Specify a version number once a release has been made.
740 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
742 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON};
743 @item @url{http://zlib.net, zlib};
744 @item @url{http://www.gnu.org/software/make/, GNU Make}.
747 The following dependencies are optional:
751 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
752 Support for build offloading (@pxref{Daemon Offload Setup}) and
753 @command{guix copy} (@pxref{Invoking guix copy}) depends on
754 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
755 version 0.10.2 or later.
758 When @url{http://www.bzip.org, libbz2} is available,
759 @command{guix-daemon} can use it to compress build logs.
762 Unless @code{--disable-daemon} was passed to @command{configure}, the
763 following packages are also needed:
766 @item @url{http://gnupg.org/, GNU libgcrypt};
767 @item @url{http://sqlite.org, SQLite 3};
768 @item @url{http://gcc.gnu.org, GCC's g++}, with support for the
772 @cindex state directory
773 When configuring Guix on a system that already has a Guix installation,
774 be sure to specify the same state directory as the existing installation
775 using the @code{--localstatedir} option of the @command{configure}
776 script (@pxref{Directory Variables, @code{localstatedir},, standards,
777 GNU Coding Standards}). The @command{configure} script protects against
778 unintended misconfiguration of @var{localstatedir} so you do not
779 inadvertently corrupt your store (@pxref{The Store}).
781 @cindex Nix, compatibility
782 When a working installation of @url{http://nixos.org/nix/, the Nix package
783 manager} is available, you
784 can instead configure Guix with @code{--disable-daemon}. In that case,
785 Nix replaces the three dependencies above.
787 Guix is compatible with Nix, so it is possible to share the same store
788 between both. To do so, you must pass @command{configure} not only the
789 same @code{--with-store-dir} value, but also the same
790 @code{--localstatedir} value. The latter is essential because it
791 specifies where the database that stores metadata about the store is
792 located, among other things. The default values for Nix are
793 @code{--with-store-dir=/nix/store} and @code{--localstatedir=/nix/var}.
794 Note that @code{--disable-daemon} is not required if
795 your goal is to share the store with Nix.
797 @node Running the Test Suite
798 @section Running the Test Suite
801 After a successful @command{configure} and @code{make} run, it is a good
802 idea to run the test suite. It can help catch issues with the setup or
803 environment, or bugs in Guix itself---and really, reporting test
804 failures is a good way to help improve the software. To run the test
811 Test cases can run in parallel: you can use the @code{-j} option of
812 GNU@tie{}make to speed things up. The first run may take a few minutes
813 on a recent machine; subsequent runs will be faster because the store
814 that is created for test purposes will already have various things in
817 It is also possible to run a subset of the tests by defining the
818 @code{TESTS} makefile variable as in this example:
821 make check TESTS="tests/store.scm tests/cpio.scm"
824 By default, tests results are displayed at a file level. In order to
825 see the details of every individual test cases, it is possible to define
826 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
829 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
832 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
833 @file{test-suite.log} file. Please specify the Guix version being used
834 as well as version numbers of the dependencies (@pxref{Requirements}) in
837 Guix also comes with a whole-system test suite that tests complete
838 Guix System instances. It can only run on systems where
839 Guix is already installed, using:
846 or, again, by defining @code{TESTS} to select a subset of tests to run:
849 make check-system TESTS="basic mcron"
852 These system tests are defined in the @code{(gnu tests @dots{})}
853 modules. They work by running the operating systems under test with
854 lightweight instrumentation in a virtual machine (VM). They can be
855 computationally intensive or rather cheap, depending on whether
856 substitutes are available for their dependencies (@pxref{Substitutes}).
857 Some of them require a lot of storage space to hold VM images.
859 Again in case of test failures, please send @email{bug-guix@@gnu.org}
862 @node Setting Up the Daemon
863 @section Setting Up the Daemon
866 Operations such as building a package or running the garbage collector
867 are all performed by a specialized process, the @dfn{build daemon}, on
868 behalf of clients. Only the daemon may access the store and its
869 associated database. Thus, any operation that manipulates the store
870 goes through the daemon. For instance, command-line tools such as
871 @command{guix package} and @command{guix build} communicate with the
872 daemon (@i{via} remote procedure calls) to instruct it what to do.
874 The following sections explain how to prepare the build daemon's
875 environment. See also @ref{Substitutes}, for information on how to allow
876 the daemon to download pre-built binaries.
879 * Build Environment Setup:: Preparing the isolated build environment.
880 * Daemon Offload Setup:: Offloading builds to remote machines.
881 * SELinux Support:: Using an SELinux policy for the daemon.
884 @node Build Environment Setup
885 @subsection Build Environment Setup
887 @cindex build environment
888 In a standard multi-user setup, Guix and its daemon---the
889 @command{guix-daemon} program---are installed by the system
890 administrator; @file{/gnu/store} is owned by @code{root} and
891 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
892 Guix tools to build packages or otherwise access the store, and the
893 daemon will do it on their behalf, ensuring that the store is kept in a
894 consistent state, and allowing built packages to be shared among users.
897 When @command{guix-daemon} runs as @code{root}, you may not want package
898 build processes themselves to run as @code{root} too, for obvious
899 security reasons. To avoid that, a special pool of @dfn{build users}
900 should be created for use by build processes started by the daemon.
901 These build users need not have a shell and a home directory: they will
902 just be used when the daemon drops @code{root} privileges in build
903 processes. Having several such users allows the daemon to launch
904 distinct build processes under separate UIDs, which guarantees that they
905 do not interfere with each other---an essential feature since builds are
906 regarded as pure functions (@pxref{Introduction}).
908 On a GNU/Linux system, a build user pool may be created like this (using
909 Bash syntax and the @code{shadow} commands):
911 @c See http://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
912 @c for why `-G' is needed.
914 # groupadd --system guixbuild
915 # for i in `seq -w 1 10`;
917 useradd -g guixbuild -G guixbuild \
918 -d /var/empty -s `which nologin` \
919 -c "Guix build user $i" --system \
925 The number of build users determines how many build jobs may run in
926 parallel, as specified by the @option{--max-jobs} option
927 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
928 @command{guix system vm} and related commands, you may need to add the
929 build users to the @code{kvm} group so they can access @file{/dev/kvm},
930 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
931 (@pxref{Invoking guix system}).
933 The @code{guix-daemon} program may then be run as @code{root} with the
934 following command@footnote{If your machine uses the systemd init system,
935 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
936 file in @file{/etc/systemd/system} will ensure that
937 @command{guix-daemon} is automatically started. Similarly, if your
938 machine uses the Upstart init system, drop the
939 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
940 file in @file{/etc/init}.}:
943 # guix-daemon --build-users-group=guixbuild
948 This way, the daemon starts build processes in a chroot, under one of
949 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
950 environment contains nothing but:
952 @c Keep this list in sync with libstore/build.cc! -----------------------
955 a minimal @code{/dev} directory, created mostly independently from the
956 host @code{/dev}@footnote{``Mostly'', because while the set of files
957 that appear in the chroot's @code{/dev} is fixed, most of these files
958 can only be created if the host has them.};
961 the @code{/proc} directory; it only shows the processes of the container
962 since a separate PID name space is used;
965 @file{/etc/passwd} with an entry for the current user and an entry for
969 @file{/etc/group} with an entry for the user's group;
972 @file{/etc/hosts} with an entry that maps @code{localhost} to
976 a writable @file{/tmp} directory.
979 You can influence the directory where the daemon stores build trees
980 @i{via} the @code{TMPDIR} environment variable. However, the build tree
981 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
982 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
983 This way, the value of @code{TMPDIR} does not leak inside build
984 environments, which avoids discrepancies in cases where build processes
985 capture the name of their build tree.
988 The daemon also honors the @code{http_proxy} environment variable for
989 HTTP downloads it performs, be it for fixed-output derivations
990 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
992 If you are installing Guix as an unprivileged user, it is still possible
993 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
994 However, build processes will not be isolated from one another, and not
995 from the rest of the system. Thus, build processes may interfere with
996 each other, and may access programs, libraries, and other files
997 available on the system---making it much harder to view them as
998 @emph{pure} functions.
1001 @node Daemon Offload Setup
1002 @subsection Using the Offload Facility
1006 When desired, the build daemon can @dfn{offload} derivation builds to
1007 other machines running Guix, using the @code{offload} @dfn{build
1008 hook}@footnote{This feature is available only when
1009 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1010 present.}. When that
1011 feature is enabled, a list of user-specified build machines is read from
1012 @file{/etc/guix/machines.scm}; every time a build is requested, for
1013 instance via @code{guix build}, the daemon attempts to offload it to one
1014 of the machines that satisfy the constraints of the derivation, in
1015 particular its system type---e.g., @file{x86_64-linux}. Missing
1016 prerequisites for the build are copied over SSH to the target machine,
1017 which then proceeds with the build; upon success the output(s) of the
1018 build are copied back to the initial machine.
1020 The @file{/etc/guix/machines.scm} file typically looks like this:
1023 (list (build-machine
1024 (name "eightysix.example.org")
1025 (system "x86_64-linux")
1026 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1028 (speed 2.)) ;incredibly fast!
1031 (name "meeps.example.org")
1032 (system "mips64el-linux")
1033 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1036 (string-append (getenv "HOME")
1037 "/.ssh/identity-for-guix"))))
1041 In the example above we specify a list of two build machines, one for
1042 the @code{x86_64} architecture and one for the @code{mips64el}
1045 In fact, this file is---not surprisingly!---a Scheme file that is
1046 evaluated when the @code{offload} hook is started. Its return value
1047 must be a list of @code{build-machine} objects. While this example
1048 shows a fixed list of build machines, one could imagine, say, using
1049 DNS-SD to return a list of potential build machines discovered in the
1050 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1051 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1054 @deftp {Data Type} build-machine
1055 This data type represents build machines to which the daemon may offload
1056 builds. The important fields are:
1061 The host name of the remote machine.
1064 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1067 The user account to use when connecting to the remote machine over SSH.
1068 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1069 allow non-interactive logins.
1072 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1073 This is used to authenticate the machine when we connect to it. It is a
1074 long string that looks like this:
1077 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1080 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1081 key can be found in a file such as
1082 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1084 If the machine is running the SSH daemon of GNU@tie{}lsh,
1085 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1086 similar file. It can be converted to the OpenSSH format using
1087 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1090 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1091 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1096 A number of optional fields may be specified:
1100 @item @code{port} (default: @code{22})
1101 Port number of SSH server on the machine.
1103 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1104 The SSH private key file to use when connecting to the machine, in
1105 OpenSSH format. This key must not be protected with a passphrase.
1107 Note that the default value is the private key @emph{of the root
1108 account}. Make sure it exists if you use the default.
1110 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1111 @itemx @code{compression-level} (default: @code{3})
1112 The SSH-level compression methods and compression level requested.
1114 Note that offloading relies on SSH compression to reduce bandwidth usage
1115 when transferring files to and from build machines.
1117 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1118 File name of the Unix-domain socket @command{guix-daemon} is listening
1121 @item @code{parallel-builds} (default: @code{1})
1122 The number of builds that may run in parallel on the machine.
1124 @item @code{speed} (default: @code{1.0})
1125 A ``relative speed factor''. The offload scheduler will tend to prefer
1126 machines with a higher speed factor.
1128 @item @code{features} (default: @code{'()})
1129 A list of strings denoting specific features supported by the machine.
1130 An example is @code{"kvm"} for machines that have the KVM Linux modules
1131 and corresponding hardware support. Derivations can request features by
1132 name, and they will be scheduled on matching build machines.
1137 The @command{guix} command must be in the search path on the build
1138 machines. You can check whether this is the case by running:
1141 ssh build-machine guix repl --version
1144 There is one last thing to do once @file{machines.scm} is in place. As
1145 explained above, when offloading, files are transferred back and forth
1146 between the machine stores. For this to work, you first need to
1147 generate a key pair on each machine to allow the daemon to export signed
1148 archives of files from the store (@pxref{Invoking guix archive}):
1151 # guix archive --generate-key
1155 Each build machine must authorize the key of the master machine so that
1156 it accepts store items it receives from the master:
1159 # guix archive --authorize < master-public-key.txt
1163 Likewise, the master machine must authorize the key of each build machine.
1165 All the fuss with keys is here to express pairwise mutual trust
1166 relations between the master and the build machines. Concretely, when
1167 the master receives files from a build machine (and @i{vice versa}), its
1168 build daemon can make sure they are genuine, have not been tampered
1169 with, and that they are signed by an authorized key.
1171 @cindex offload test
1172 To test whether your setup is operational, run this command on the
1179 This will attempt to connect to each of the build machines specified in
1180 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1181 available on each machine, attempt to export to the machine and import
1182 from it, and report any error in the process.
1184 If you want to test a different machine file, just specify it on the
1188 # guix offload test machines-qualif.scm
1191 Last, you can test the subset of the machines whose name matches a
1192 regular expression like this:
1195 # guix offload test machines.scm '\.gnu\.org$'
1198 @cindex offload status
1199 To display the current load of all build hosts, run this command on the
1203 # guix offload status
1207 @node SELinux Support
1208 @subsection SELinux Support
1210 @cindex SELinux, daemon policy
1211 @cindex mandatory access control, SELinux
1212 @cindex security, guix-daemon
1213 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1214 can be installed on a system where SELinux is enabled, in order to label
1215 Guix files and to specify the expected behavior of the daemon. Since
1216 Guix System does not provide an SELinux base policy, the daemon policy cannot
1217 be used on Guix System.
1219 @subsubsection Installing the SELinux policy
1220 @cindex SELinux, policy installation
1221 To install the policy run this command as root:
1224 semodule -i etc/guix-daemon.cil
1227 Then relabel the file system with @code{restorecon} or by a different
1228 mechanism provided by your system.
1230 Once the policy is installed, the file system has been relabeled, and
1231 the daemon has been restarted, it should be running in the
1232 @code{guix_daemon_t} context. You can confirm this with the following
1236 ps -Zax | grep guix-daemon
1239 Monitor the SELinux log files as you run a command like @code{guix build
1240 hello} to convince yourself that SELinux permits all necessary
1243 @subsubsection Limitations
1244 @cindex SELinux, limitations
1246 This policy is not perfect. Here is a list of limitations or quirks
1247 that should be considered when deploying the provided SELinux policy for
1252 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1253 operations involve contexts that have anything to do with
1254 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1255 but it would be preferrable to define socket rules for only this label.
1258 @code{guix gc} cannot access arbitrary links to profiles. By design,
1259 the file label of the destination of a symlink is independent of the
1260 file label of the link itself. Although all profiles under
1261 $localstatedir are labelled, the links to these profiles inherit the
1262 label of the directory they are in. For links in the user’s home
1263 directory this will be @code{user_home_t}. But for links from the root
1264 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1265 directory, etc, this won’t work. @code{guix gc} would be prevented from
1266 reading and following these links.
1269 The daemon’s feature to listen for TCP connections might no longer work.
1270 This might require extra rules, because SELinux treats network sockets
1271 differently from files.
1274 Currently all files with a name matching the regular expression
1275 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1276 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1277 that name in any profile would be permitted to run in the
1278 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1279 build a package that provides this executable and convince a user to
1280 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1281 At that point SELinux could not prevent it from accessing files that are
1282 allowed for processes in that domain.
1284 We could generate a much more restrictive policy at installation time,
1285 so that only the @emph{exact} file name of the currently installed
1286 @code{guix-daemon} executable would be labelled with
1287 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1288 The downside is that root would have to install or upgrade the policy at
1289 installation time whenever the Guix package that provides the
1290 effectively running @code{guix-daemon} executable is upgraded.
1293 @node Invoking guix-daemon
1294 @section Invoking @command{guix-daemon}
1296 The @command{guix-daemon} program implements all the functionality to
1297 access the store. This includes launching build processes, running the
1298 garbage collector, querying the availability of a build result, etc. It
1299 is normally run as @code{root} like this:
1302 # guix-daemon --build-users-group=guixbuild
1306 For details on how to set it up, @pxref{Setting Up the Daemon}.
1309 @cindex container, build environment
1310 @cindex build environment
1311 @cindex reproducible builds
1312 By default, @command{guix-daemon} launches build processes under
1313 different UIDs, taken from the build group specified with
1314 @code{--build-users-group}. In addition, each build process is run in a
1315 chroot environment that only contains the subset of the store that the
1316 build process depends on, as specified by its derivation
1317 (@pxref{Programming Interface, derivation}), plus a set of specific
1318 system directories. By default, the latter contains @file{/dev} and
1319 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1320 @dfn{container}: in addition to having its own file system tree, it has
1321 a separate mount name space, its own PID name space, network name space,
1322 etc. This helps achieve reproducible builds (@pxref{Features}).
1324 When the daemon performs a build on behalf of the user, it creates a
1325 build directory under @file{/tmp} or under the directory specified by
1326 its @code{TMPDIR} environment variable. This directory is shared with
1327 the container for the duration of the build, though within the container,
1328 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1330 The build directory is automatically deleted upon completion, unless the
1331 build failed and the client specified @option{--keep-failed}
1332 (@pxref{Invoking guix build, @option{--keep-failed}}).
1334 The daemon listens for connections and spawns one sub-process for each session
1335 started by a client (one of the @command{guix} sub-commands.) The
1336 @command{guix processes} command allows you to get an overview of the activity
1337 on your system by viewing each of the active sessions and clients.
1338 @xref{Invoking guix processes}, for more information.
1340 The following command-line options are supported:
1343 @item --build-users-group=@var{group}
1344 Take users from @var{group} to run build processes (@pxref{Setting Up
1345 the Daemon, build users}).
1347 @item --no-substitutes
1349 Do not use substitutes for build products. That is, always build things
1350 locally instead of allowing downloads of pre-built binaries
1351 (@pxref{Substitutes}).
1353 When the daemon runs with @code{--no-substitutes}, clients can still
1354 explicitly enable substitution @i{via} the @code{set-build-options}
1355 remote procedure call (@pxref{The Store}).
1357 @item --substitute-urls=@var{urls}
1358 @anchor{daemon-substitute-urls}
1359 Consider @var{urls} the default whitespace-separated list of substitute
1360 source URLs. When this option is omitted,
1361 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1363 This means that substitutes may be downloaded from @var{urls}, as long
1364 as they are signed by a trusted signature (@pxref{Substitutes}).
1367 @item --no-build-hook
1368 Do not use the @dfn{build hook}.
1370 The build hook is a helper program that the daemon can start and to
1371 which it submits build requests. This mechanism is used to offload
1372 builds to other machines (@pxref{Daemon Offload Setup}).
1374 @item --cache-failures
1375 Cache build failures. By default, only successful builds are cached.
1377 When this option is used, @command{guix gc --list-failures} can be used
1378 to query the set of store items marked as failed; @command{guix gc
1379 --clear-failures} removes store items from the set of cached failures.
1380 @xref{Invoking guix gc}.
1382 @item --cores=@var{n}
1384 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1387 The default value is @code{0}, but it may be overridden by clients, such
1388 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1391 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1392 in the build process, which can then use it to exploit internal
1393 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1395 @item --max-jobs=@var{n}
1397 Allow at most @var{n} build jobs in parallel. The default value is
1398 @code{1}. Setting it to @code{0} means that no builds will be performed
1399 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1400 Setup}), or simply fail.
1402 @item --max-silent-time=@var{seconds}
1403 When the build or substitution process remains silent for more than
1404 @var{seconds}, terminate it and report a build failure.
1406 The default value is @code{0}, which disables the timeout.
1408 The value specified here can be overridden by clients (@pxref{Common
1409 Build Options, @code{--max-silent-time}}).
1411 @item --timeout=@var{seconds}
1412 Likewise, when the build or substitution process lasts for more than
1413 @var{seconds}, terminate it and report a build failure.
1415 The default value is @code{0}, which disables the timeout.
1417 The value specified here can be overridden by clients (@pxref{Common
1418 Build Options, @code{--timeout}}).
1420 @item --rounds=@var{N}
1421 Build each derivation @var{n} times in a row, and raise an error if
1422 consecutive build results are not bit-for-bit identical. Note that this
1423 setting can be overridden by clients such as @command{guix build}
1424 (@pxref{Invoking guix build}).
1426 When used in conjunction with @option{--keep-failed}, the differing
1427 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1428 This makes it easy to look for differences between the two results.
1431 Produce debugging output.
1433 This is useful to debug daemon start-up issues, but then it may be
1434 overridden by clients, for example the @code{--verbosity} option of
1435 @command{guix build} (@pxref{Invoking guix build}).
1437 @item --chroot-directory=@var{dir}
1438 Add @var{dir} to the build chroot.
1440 Doing this may change the result of build processes---for instance if
1441 they use optional dependencies found in @var{dir} when it is available,
1442 and not otherwise. For that reason, it is not recommended to do so.
1443 Instead, make sure that each derivation declares all the inputs that it
1446 @item --disable-chroot
1447 Disable chroot builds.
1449 Using this option is not recommended since, again, it would allow build
1450 processes to gain access to undeclared dependencies. It is necessary,
1451 though, when @command{guix-daemon} is running under an unprivileged user
1454 @item --log-compression=@var{type}
1455 Compress build logs according to @var{type}, one of @code{gzip},
1456 @code{bzip2}, or @code{none}.
1458 Unless @code{--lose-logs} is used, all the build logs are kept in the
1459 @var{localstatedir}. To save space, the daemon automatically compresses
1460 them with bzip2 by default.
1462 @item --disable-deduplication
1463 @cindex deduplication
1464 Disable automatic file ``deduplication'' in the store.
1466 By default, files added to the store are automatically ``deduplicated'':
1467 if a newly added file is identical to another one found in the store,
1468 the daemon makes the new file a hard link to the other file. This can
1469 noticeably reduce disk usage, at the expense of slightly increased
1470 input/output load at the end of a build process. This option disables
1473 @item --gc-keep-outputs[=yes|no]
1474 Tell whether the garbage collector (GC) must keep outputs of live
1478 @cindex garbage collector roots
1479 When set to ``yes'', the GC will keep the outputs of any live derivation
1480 available in the store---the @code{.drv} files. The default is ``no'',
1481 meaning that derivation outputs are kept only if they are reachable from a GC
1482 root. @xref{Invoking guix gc}, for more on GC roots.
1484 @item --gc-keep-derivations[=yes|no]
1485 Tell whether the garbage collector (GC) must keep derivations
1486 corresponding to live outputs.
1488 When set to ``yes'', as is the case by default, the GC keeps
1489 derivations---i.e., @code{.drv} files---as long as at least one of their
1490 outputs is live. This allows users to keep track of the origins of
1491 items in their store. Setting it to ``no'' saves a bit of disk space.
1493 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1494 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1495 ``yes'' causes liveness to flow from derivations to outputs. When both are
1496 set to ``yes'', the effect is to keep all the build prerequisites (the
1497 sources, compiler, libraries, and other build-time tools) of live objects in
1498 the store, regardless of whether these prerequisites are reachable from a GC
1499 root. This is convenient for developers since it saves rebuilds or downloads.
1501 @item --impersonate-linux-2.6
1502 On Linux-based systems, impersonate Linux 2.6. This means that the
1503 kernel's @code{uname} system call will report 2.6 as the release number.
1505 This might be helpful to build programs that (usually wrongfully) depend
1506 on the kernel version number.
1509 Do not keep build logs. By default they are kept under
1510 @code{@var{localstatedir}/guix/log}.
1512 @item --system=@var{system}
1513 Assume @var{system} as the current system type. By default it is the
1514 architecture/kernel pair found at configure time, such as
1515 @code{x86_64-linux}.
1517 @item --listen=@var{endpoint}
1518 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1519 as the file name of a Unix-domain socket if it starts with
1520 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1521 host name or host name and port to listen to. Here are a few examples:
1524 @item --listen=/gnu/var/daemon
1525 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1526 creating it if needed.
1528 @item --listen=localhost
1529 @cindex daemon, remote access
1530 @cindex remote access to the daemon
1531 @cindex daemon, cluster setup
1532 @cindex clusters, daemon setup
1533 Listen for TCP connections on the network interface corresponding to
1534 @code{localhost}, on port 44146.
1536 @item --listen=128.0.0.42:1234
1537 Listen for TCP connections on the network interface corresponding to
1538 @code{128.0.0.42}, on port 1234.
1541 This option can be repeated multiple times, in which case
1542 @command{guix-daemon} accepts connections on all the specified
1543 endpoints. Users can tell client commands what endpoint to connect to
1544 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1545 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1548 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1549 @code{--listen=@var{host}} is suitable on local networks, such as
1550 clusters, where only trusted nodes may connect to the build daemon. In
1551 other cases where remote access to the daemon is needed, we recommend
1552 using Unix-domain sockets along with SSH.
1555 When @code{--listen} is omitted, @command{guix-daemon} listens for
1556 connections on the Unix-domain socket located at
1557 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1561 @node Application Setup
1562 @section Application Setup
1564 @cindex foreign distro
1565 When using Guix on top of GNU/Linux distribution other than Guix System---a
1566 so-called @dfn{foreign distro}---a few additional steps are needed to
1567 get everything in place. Here are some of them.
1571 @anchor{locales-and-locpath}
1572 @cindex locales, when not on Guix System
1574 @vindex GUIX_LOCPATH
1575 Packages installed @i{via} Guix will not use the locale data of the
1576 host system. Instead, you must first install one of the locale packages
1577 available with Guix and then define the @code{GUIX_LOCPATH} environment
1581 $ guix install glibc-locales
1582 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1585 Note that the @code{glibc-locales} package contains data for all the
1586 locales supported by the GNU@tie{}libc and weighs in at around
1587 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1588 limited to a few UTF-8 locales.
1590 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1591 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1592 Manual}). There are two important differences though:
1596 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1597 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1598 to make sure the programs of the foreign distro will not end up loading
1599 incompatible locale data.
1602 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1603 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1604 should your Guix profile contain a mixture of programs linked against
1605 different libc version, each libc version will only try to load locale
1606 data in the right format.
1609 This is important because the locale data format used by different libc
1610 versions may be incompatible.
1612 @subsection Name Service Switch
1614 @cindex name service switch, glibc
1615 @cindex NSS (name service switch), glibc
1616 @cindex nscd (name service caching daemon)
1617 @cindex name service caching daemon (nscd)
1618 When using Guix on a foreign distro, we @emph{strongly recommend} that
1619 the system run the GNU C library's @dfn{name service cache daemon},
1620 @command{nscd}, which should be listening on the
1621 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1622 installed with Guix may fail to look up host names or user accounts, or
1623 may even crash. The next paragraphs explain why.
1625 @cindex @file{nsswitch.conf}
1626 The GNU C library implements a @dfn{name service switch} (NSS), which is
1627 an extensible mechanism for ``name lookups'' in general: host name
1628 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1629 The GNU C Library Reference Manual}).
1631 @cindex Network information service (NIS)
1632 @cindex NIS (Network information service)
1633 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1634 lookup implementations: for example, the @code{nss-mdns} plugin allow
1635 resolution of @code{.local} host names, the @code{nis} plugin allows
1636 user account lookup using the Network information service (NIS), and so
1637 on. These extra ``lookup services'' are configured system-wide in
1638 @file{/etc/nsswitch.conf}, and all the programs running on the system
1639 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1642 When they perform a name lookup---for instance by calling the
1643 @code{getaddrinfo} function in C---applications first try to connect to
1644 the nscd; on success, nscd performs name lookups on their behalf. If
1645 the nscd is not running, then they perform the name lookup by
1646 themselves, by loading the name lookup services into their own address
1647 space and running it. These name lookup services---the
1648 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1649 the host system's C library, rather than from the C library the
1650 application is linked against (the C library coming from Guix).
1652 And this is where the problem is: if your application is linked against
1653 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1654 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1655 likely crash or have its name lookups fail unexpectedly.
1657 Running @command{nscd} on the system, among other advantages, eliminates
1658 this binary incompatibility problem because those @code{libnss_*.so}
1659 files are loaded in the @command{nscd} process, not in applications
1662 @subsection X11 Fonts
1665 The majority of graphical applications use Fontconfig to locate and
1666 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1667 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1668 by default. Thus, to allow graphical applications installed with Guix
1669 to display fonts, you have to install fonts with Guix as well.
1670 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1671 @code{font-gnu-freefont-ttf}.
1673 To display text written in Chinese languages, Japanese, or Korean in
1674 graphical applications, consider installing
1675 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1676 has multiple outputs, one per language family (@pxref{Packages with
1677 Multiple Outputs}). For instance, the following command installs fonts
1678 for Chinese languages:
1681 guix install font-adobe-source-han-sans:cn
1684 @cindex @code{xterm}
1685 Older programs such as @command{xterm} do not use Fontconfig and instead
1686 rely on server-side font rendering. Such programs require to specify a
1687 full name of a font using XLFD (X Logical Font Description), like this:
1690 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1693 To be able to use such full names for the TrueType fonts installed in
1694 your Guix profile, you need to extend the font path of the X server:
1696 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1697 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1699 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1702 @cindex @code{xlsfonts}
1703 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1704 to make sure your TrueType fonts are listed there.
1706 @cindex @code{fc-cache}
1708 After installing fonts you may have to refresh the font cache to use
1709 them in applications. The same applies when applications installed via
1710 Guix do not seem to find fonts. To force rebuilding of the font cache
1711 run @code{fc-cache -f}. The @code{fc-cache} command is provided by the
1712 @code{fontconfig} package.
1714 @subsection X.509 Certificates
1716 @cindex @code{nss-certs}
1717 The @code{nss-certs} package provides X.509 certificates, which allow
1718 programs to authenticate Web servers accessed over HTTPS.
1720 When using Guix on a foreign distro, you can install this package and
1721 define the relevant environment variables so that packages know where to
1722 look for certificates. @xref{X.509 Certificates}, for detailed
1725 @subsection Emacs Packages
1727 @cindex @code{emacs}
1728 When you install Emacs packages with Guix, the elisp files may be placed
1729 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1731 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1732 directory exists because potentially there may exist thousands of Emacs
1733 packages and storing all their files in a single directory may not be
1734 reliable (because of name conflicts). So we think using a separate
1735 directory for each package is a good idea. It is very similar to how
1736 the Emacs package system organizes the file structure (@pxref{Package
1737 Files,,, emacs, The GNU Emacs Manual}).
1739 By default, Emacs (installed with Guix) ``knows'' where these packages
1740 are placed, so you do not need to perform any configuration. If, for
1741 some reason, you want to avoid auto-loading Emacs packages installed
1742 with Guix, you can do so by running Emacs with @code{--no-site-file}
1743 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1745 @subsection The GCC toolchain
1750 Guix offers individual compiler packages such as @code{gcc} but if you
1751 are in need of a complete toolchain for compiling and linking source
1752 code what you really want is the @code{gcc-toolchain} package. This
1753 package provides a complete GCC toolchain for C/C++ development,
1754 including GCC itself, the GNU C Library (headers and binaries, plus
1755 debugging symbols in the @code{debug} output), Binutils, and a linker
1758 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1759 passed to the linker, add corresponding @code{-rpath} arguments, and
1760 invoke the actual linker with this new set of arguments. You can instruct the
1761 wrapper to refuse to link against libraries not in the store by setting the
1762 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
1766 @c *********************************************************************
1767 @node System Installation
1768 @chapter System Installation
1770 @cindex installing Guix System
1771 @cindex Guix System, installation
1772 This section explains how to install Guix System
1773 on a machine. Guix, as a package manager, can
1774 also be installed on top of a running GNU/Linux system,
1775 @pxref{Installation}.
1779 @c This paragraph is for people reading this from tty2 of the
1780 @c installation image.
1781 You are reading this documentation with an Info reader. For details on
1782 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1783 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1784 Info}. Hit @kbd{l} afterwards to come back here.
1786 Alternately, run @command{info info} in another tty to keep the manual
1792 * Limitations:: What you can expect.
1793 * Hardware Considerations:: Supported hardware.
1794 * USB Stick and DVD Installation:: Preparing the installation medium.
1795 * Preparing for Installation:: Networking, partitioning, etc.
1796 * Guided Graphical Installation:: Easy graphical installation.
1797 * Manual Installation:: Manual installation for wizards.
1798 * After System Installation:: When installation succeeded.
1799 * Installing Guix in a VM:: Guix System playground.
1800 * Building the Installation Image:: How this comes to be.
1804 @section Limitations
1806 We consider Guix System to be ready for a wide range of ``desktop'' and server
1807 use cases. The reliability guarantees it provides---transactional upgrades
1808 and rollbacks, reproducibility---make it a solid foundation.
1810 Nevertheless, before you proceed with the installation, be aware of the
1811 following noteworthy limitations applicable to version @value{VERSION}:
1815 Support for the Logical Volume Manager (LVM) is missing.
1818 More and more system services are provided (@pxref{Services}), but some
1822 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1823 as well as a number of X11 window managers. However, KDE is currently
1827 More than a disclaimer, this is an invitation to report issues (and success
1828 stories!), and to join us in improving it. @xref{Contributing}, for more
1832 @node Hardware Considerations
1833 @section Hardware Considerations
1835 @cindex hardware support on Guix System
1836 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1837 builds around the kernel Linux-libre, which means that only hardware for
1838 which free software drivers and firmware exist is supported. Nowadays,
1839 a wide range of off-the-shelf hardware is supported on
1840 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1841 Ethernet controllers. Unfortunately, there are still areas where
1842 hardware vendors deny users control over their own computing, and such
1843 hardware is not supported on Guix System.
1845 @cindex WiFi, hardware support
1846 One of the main areas where free drivers or firmware are lacking is WiFi
1847 devices. WiFi devices known to work include those using Atheros chips
1848 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1849 driver, and those using Broadcom/AirForce chips (BCM43xx with
1850 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1851 Linux-libre driver. Free firmware exists for both and is available
1852 out-of-the-box on Guix System, as part of @code{%base-firmware}
1853 (@pxref{operating-system Reference, @code{firmware}}).
1855 @cindex RYF, Respects Your Freedom
1856 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1857 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1858 certification program for hardware products that respect your freedom
1859 and your privacy and ensure that you have control over your device. We
1860 encourage you to check the list of RYF-certified devices.
1862 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1863 web site. It contains a catalog of hardware devices with information
1864 about their support in GNU/Linux.
1867 @node USB Stick and DVD Installation
1868 @section USB Stick and DVD Installation
1870 An ISO-9660 installation image that can be written to a USB stick or
1871 burnt to a DVD can be downloaded from
1872 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1873 where @var{system} is one of:
1877 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1880 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1883 @c start duplication of authentication part from ``Binary Installation''
1884 Make sure to download the associated @file{.sig} file and to verify the
1885 authenticity of the image against it, along these lines:
1888 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1889 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1892 If that command fails because you do not have the required public key,
1893 then run this command to import it:
1896 $ gpg --keyserver @value{KEY-SERVER} \
1897 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
1901 and rerun the @code{gpg --verify} command.
1904 This image contains the tools necessary for an installation.
1905 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1907 @unnumberedsubsec Copying to a USB Stick
1909 To copy the image to a USB stick, follow these steps:
1913 Decompress the image using the @command{xz} command:
1916 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1920 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1921 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1922 copy the image with:
1925 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1929 Access to @file{/dev/sdX} usually requires root privileges.
1932 @unnumberedsubsec Burning on a DVD
1934 To copy the image to a DVD, follow these steps:
1938 Decompress the image using the @command{xz} command:
1941 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1945 Insert a blank DVD into your machine, and determine
1946 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
1947 copy the image with:
1950 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
1953 Access to @file{/dev/srX} usually requires root privileges.
1956 @unnumberedsubsec Booting
1958 Once this is done, you should be able to reboot the system and boot from
1959 the USB stick or DVD. The latter usually requires you to get in the
1960 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
1962 @xref{Installing Guix in a VM}, if, instead, you would like to install
1963 Guix System in a virtual machine (VM).
1966 @node Preparing for Installation
1967 @section Preparing for Installation
1969 Once you have booted, you can use the guided graphical installer, which makes
1970 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
1971 if you are already familiar with GNU/Linux and if you want more control than
1972 what the graphical installer provides, you can choose the ``manual''
1973 installation process (@pxref{Manual Installation}).
1975 The graphical installer is available on TTY1. You can obtain root shells on
1976 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
1977 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
1978 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
1979 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
1980 which allows you to select text with the left mouse button and to paste it
1981 with the middle button.
1984 Installation requires access to the Internet so that any missing
1985 dependencies of your system configuration can be downloaded. See the
1986 ``Networking'' section below.
1989 @node Guided Graphical Installation
1990 @section Guided Graphical Installation
1992 The graphical installer is a text-based user interface. It will guide you,
1993 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
1995 The first dialog boxes allow you to set up the system as you use it during the
1996 installation: you can choose the language, keyboard layout, and set up
1997 networking, which will be used during the installation. The image below shows
1998 the networking dialog.
2000 @image{images/installer-network,5in,, networking setup with the graphical installer}
2002 Later steps allow you to partition your hard disk, as shown in the image
2003 below, to choose whether or not to use encrypted file systems, to enter the
2004 host name and root password, and to create an additional account, among other
2007 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2009 Note that, at any time, the installer allows you to exit the current
2010 installation step and resume at a previous step, as show in the image below.
2012 @image{images/installer-resume,5in,, resuming the installation process}
2014 Once you're done, the installer produces an operating system configuration and
2015 displays it (@pxref{Using the Configuration System}). At that point you can
2016 hit ``OK'' and installation will proceed. On success, you can reboot into the
2017 new system and enjoy. @xref{After System Installation}, for what's next!
2020 @node Manual Installation
2021 @section Manual Installation
2023 This section describes how you would ``manually'' install GNU@tie{}Guix System
2024 on your machine. This option requires familiarity with GNU/Linux, with the
2025 shell, and with common administration tools. If you think this is not for
2026 you, consider using the guided graphical installer (@pxref{Guided Graphical
2029 The installation system provides root shells on TTYs 3 to 6; press
2030 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2031 many common tools needed to install the system. But it is also a full-blown
2032 Guix System, which means that you can install additional packages, should you
2033 need it, using @command{guix package} (@pxref{Invoking guix package}).
2036 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2037 * Proceeding with the Installation:: Installing.
2040 @node Keyboard Layout and Networking and Partitioning
2041 @subsection Keyboard Layout, Networking, and Partitioning
2043 Before you can install the system, you may want to adjust the keyboard layout,
2044 set up networking, and partition your target hard disk. This section will
2045 guide you through this.
2047 @subsubsection Keyboard Layout
2049 @cindex keyboard layout
2050 The installation image uses the US qwerty keyboard layout. If you want
2051 to change it, you can use the @command{loadkeys} command. For example,
2052 the following command selects the Dvorak keyboard layout:
2058 See the files under @file{/run/current-system/profile/share/keymaps} for
2059 a list of available keyboard layouts. Run @command{man loadkeys} for
2062 @subsubsection Networking
2064 Run the following command to see what your network interfaces are called:
2071 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2077 @c http://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2078 Wired interfaces have a name starting with @samp{e}; for example, the
2079 interface corresponding to the first on-board Ethernet controller is
2080 called @samp{eno1}. Wireless interfaces have a name starting with
2081 @samp{w}, like @samp{w1p2s0}.
2084 @item Wired connection
2085 To configure a wired network run the following command, substituting
2086 @var{interface} with the name of the wired interface you want to use.
2089 ifconfig @var{interface} up
2092 @item Wireless connection
2095 To configure wireless networking, you can create a configuration file
2096 for the @command{wpa_supplicant} configuration tool (its location is not
2097 important) using one of the available text editors such as
2101 nano wpa_supplicant.conf
2104 As an example, the following stanza can go to this file and will work
2105 for many wireless networks, provided you give the actual SSID and
2106 passphrase for the network you are connecting to:
2110 ssid="@var{my-ssid}"
2112 psk="the network's secret passphrase"
2116 Start the wireless service and run it in the background with the
2117 following command (substitute @var{interface} with the name of the
2118 network interface you want to use):
2121 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2124 Run @command{man wpa_supplicant} for more information.
2128 At this point, you need to acquire an IP address. On a network where IP
2129 addresses are automatically assigned @i{via} DHCP, you can run:
2132 dhclient -v @var{interface}
2135 Try to ping a server to see if networking is up and running:
2141 Setting up network access is almost always a requirement because the
2142 image does not contain all the software and tools that may be needed.
2144 @cindex installing over SSH
2145 If you want to, you can continue the installation remotely by starting
2149 herd start ssh-daemon
2152 Make sure to either set a password with @command{passwd}, or configure
2153 OpenSSH public key authentication before logging in.
2155 @subsubsection Disk Partitioning
2157 Unless this has already been done, the next step is to partition, and
2158 then format the target partition(s).
2160 The installation image includes several partitioning tools, including
2161 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2162 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2163 the partition layout you want:
2169 If your disk uses the GUID Partition Table (GPT) format and you plan to
2170 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2171 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2174 @cindex EFI, installation
2175 @cindex UEFI, installation
2176 @cindex ESP, EFI system partition
2177 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2178 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2179 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2182 parted /dev/sda set 1 esp on
2186 @vindex grub-bootloader
2187 @vindex grub-efi-bootloader
2188 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2189 @file{/sys/firmware/efi} exists in the installation image, then you should
2190 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2191 Otherwise you should use the BIOS-based GRUB, known as
2192 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2196 Once you are done partitioning the target hard disk drive, you have to
2197 create a file system on the relevant partition(s)@footnote{Currently
2198 Guix System only supports ext4 and btrfs file systems. In particular, code
2199 that reads file system UUIDs and labels only works for these file system
2200 types.}. For the ESP, if you have one and assuming it is
2201 @file{/dev/sda1}, run:
2204 mkfs.fat -F32 /dev/sda1
2207 Preferably, assign file systems a label so that you can easily and
2208 reliably refer to them in @code{file-system} declarations (@pxref{File
2209 Systems}). This is typically done using the @code{-L} option of
2210 @command{mkfs.ext4} and related commands. So, assuming the target root
2211 partition lives at @file{/dev/sda2}, a file system with the label
2212 @code{my-root} can be created with:
2215 mkfs.ext4 -L my-root /dev/sda2
2218 @cindex encrypted disk
2219 If you are instead planning to encrypt the root partition, you can use
2220 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2221 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2222 @code{man cryptsetup}} for more information.) Assuming you want to
2223 store the root partition on @file{/dev/sda2}, the command sequence would
2224 be along these lines:
2227 cryptsetup luksFormat /dev/sda2
2228 cryptsetup open --type luks /dev/sda2 my-partition
2229 mkfs.ext4 -L my-root /dev/mapper/my-partition
2232 Once that is done, mount the target file system under @file{/mnt}
2233 with a command like (again, assuming @code{my-root} is the label of the
2237 mount LABEL=my-root /mnt
2240 Also mount any other file systems you would like to use on the target
2241 system relative to this path. If you have opted for @file{/boot/efi} as an
2242 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2243 found by @code{guix system init} afterwards.
2245 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2246 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2247 sure to initialize them with @command{mkswap}. Assuming you have one
2248 swap partition on @file{/dev/sda3}, you would run:
2255 Alternatively, you may use a swap file. For example, assuming that in
2256 the new system you want to use the file @file{/swapfile} as a swap file,
2257 you would run@footnote{This example will work for many types of file
2258 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2259 btrfs), the required steps may be different. For details, see the
2260 manual pages for @command{mkswap} and @command{swapon}.}:
2263 # This is 10 GiB of swap space. Adjust "count" to change the size.
2264 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2265 # For security, make the file readable and writable only by root.
2266 chmod 600 /mnt/swapfile
2267 mkswap /mnt/swapfile
2268 swapon /mnt/swapfile
2271 Note that if you have encrypted the root partition and created a swap
2272 file in its file system as described above, then the encryption also
2273 protects the swap file, just like any other file in that file system.
2275 @node Proceeding with the Installation
2276 @subsection Proceeding with the Installation
2278 With the target partitions ready and the target root mounted on
2279 @file{/mnt}, we're ready to go. First, run:
2282 herd start cow-store /mnt
2285 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2286 during the installation phase are written to the target disk on @file{/mnt}
2287 rather than kept in memory. This is necessary because the first phase of
2288 the @command{guix system init} command (see below) entails downloads or
2289 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2291 Next, you have to edit a file and
2292 provide the declaration of the operating system to be installed. To
2293 that end, the installation system comes with three text editors. We
2294 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2295 supports syntax highlighting and parentheses matching; other editors
2296 include GNU Zile (an Emacs clone), and
2297 nvi (a clone of the original BSD @command{vi} editor).
2298 We strongly recommend storing that file on the target root file system, say,
2299 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2300 configuration file once you have rebooted into the newly-installed system.
2302 @xref{Using the Configuration System}, for an overview of the
2303 configuration file. The example configurations discussed in that
2304 section are available under @file{/etc/configuration} in the
2305 installation image. Thus, to get started with a system configuration
2306 providing a graphical display server (a ``desktop'' system), you can run
2307 something along these lines:
2311 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2312 # nano /mnt/etc/config.scm
2315 You should pay attention to what your configuration file contains, and
2320 Make sure the @code{bootloader-configuration} form refers to the target
2321 you want to install GRUB on. It should mention @code{grub-bootloader} if
2322 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2323 for newer UEFI systems. For legacy systems, the @code{target} field
2324 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2325 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2326 currently mounted and a @code{file-system} entry is specified in your
2330 Be sure that your file system labels match the value of their respective
2331 @code{device} fields in your @code{file-system} configuration, assuming
2332 your @code{file-system} configuration uses the @code{file-system-label}
2333 procedure in its @code{device} field.
2336 If there are encrypted or RAID partitions, make sure to add a
2337 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2340 Once you are done preparing the configuration file, the new system must
2341 be initialized (remember that the target root file system is mounted
2345 guix system init /mnt/etc/config.scm /mnt
2349 This copies all the necessary files and installs GRUB on
2350 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2351 more information, @pxref{Invoking guix system}. This command may trigger
2352 downloads or builds of missing packages, which can take some time.
2354 Once that command has completed---and hopefully succeeded!---you can run
2355 @command{reboot} and boot into the new system. The @code{root} password
2356 in the new system is initially empty; other users' passwords need to be
2357 initialized by running the @command{passwd} command as @code{root},
2358 unless your configuration specifies otherwise
2359 (@pxref{user-account-password, user account passwords}).
2360 @xref{After System Installation}, for what's next!
2363 @node After System Installation
2364 @section After System Installation
2366 Success, you've now booted into Guix System! From then on, you can update the
2367 system whenever you want by running, say:
2371 sudo guix system reconfigure /etc/config.scm
2375 This builds a new system generation with the latest packages and services
2376 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2377 your system includes the latest security updates (@pxref{Security Updates}).
2379 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2381 @cindex sudo vs. @command{guix pull}
2382 Note that @command{sudo guix} runs your user's @command{guix} command and
2383 @emph{not} root's, because @command{sudo} leaves @code{PATH} unchanged. To
2384 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2387 Join us on @code{#guix} on the Freenode IRC network or on
2388 @email{guix-devel@@gnu.org} to share your experience!
2391 @node Installing Guix in a VM
2392 @section Installing Guix in a Virtual Machine
2394 @cindex virtual machine, Guix System installation
2395 @cindex virtual private server (VPS)
2396 @cindex VPS (virtual private server)
2397 If you'd like to install Guix System in a virtual machine (VM) or on a
2398 virtual private server (VPS) rather than on your beloved machine, this
2401 To boot a @uref{http://qemu.org/,QEMU} VM for installing Guix System in a
2402 disk image, follow these steps:
2406 First, retrieve and decompress the Guix system installation image as
2407 described previously (@pxref{USB Stick and DVD Installation}).
2410 Create a disk image that will hold the installed system. To make a
2411 qcow2-formatted disk image, use the @command{qemu-img} command:
2414 qemu-img create -f qcow2 guixsd.img 50G
2417 The resulting file will be much smaller than 50 GB (typically less than
2418 1 MB), but it will grow as the virtualized storage device is filled up.
2421 Boot the USB installation image in an VM:
2424 qemu-system-x86_64 -m 1024 -smp 1 \
2425 -net user -net nic,model=virtio -boot menu=on \
2426 -drive file=guix-system-install-@value{VERSION}.@var{system}.iso \
2427 -drive file=guixsd.img
2430 The ordering of the drives matters.
2432 In the VM console, quickly press the @kbd{F12} key to enter the boot
2433 menu. Then press the @kbd{2} key and the @kbd{RET} key to validate your
2437 You're now root in the VM, proceed with the installation process.
2438 @xref{Preparing for Installation}, and follow the instructions.
2441 Once installation is complete, you can boot the system that's on your
2442 @file{guixsd.img} image. @xref{Running Guix in a VM}, for how to do
2445 @node Building the Installation Image
2446 @section Building the Installation Image
2448 @cindex installation image
2449 The installation image described above was built using the @command{guix
2450 system} command, specifically:
2453 guix system disk-image --file-system-type=iso9660 \
2454 gnu/system/install.scm
2457 Have a look at @file{gnu/system/install.scm} in the source tree,
2458 and see also @ref{Invoking guix system} for more information
2459 about the installation image.
2461 @section Building the Installation Image for ARM Boards
2463 Many ARM boards require a specific variant of the
2464 @uref{http://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2466 If you build a disk image and the bootloader is not available otherwise
2467 (on another boot drive etc), it's advisable to build an image that
2468 includes the bootloader, specifically:
2471 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2474 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2475 board, a list of possible boards will be printed.
2477 @c *********************************************************************
2478 @node Package Management
2479 @chapter Package Management
2482 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2483 remove software packages, without having to know about their build
2484 procedures or dependencies. Guix also goes beyond this obvious set of
2487 This chapter describes the main features of Guix, as well as the
2488 package management tools it provides. Along with the command-line
2489 interface described below (@pxref{Invoking guix package, @code{guix
2490 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2491 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2492 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2496 guix install emacs-guix
2500 * Features:: How Guix will make your life brighter.
2501 * Invoking guix package:: Package installation, removal, etc.
2502 * Substitutes:: Downloading pre-built binaries.
2503 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2504 * Invoking guix gc:: Running the garbage collector.
2505 * Invoking guix pull:: Fetching the latest Guix and distribution.
2506 * Channels:: Customizing the package collection.
2507 * Inferiors:: Interacting with another revision of Guix.
2508 * Invoking guix describe:: Display information about your Guix revision.
2509 * Invoking guix archive:: Exporting and importing store files.
2515 When using Guix, each package ends up in the @dfn{package store}, in its
2516 own directory---something that resembles
2517 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2519 Instead of referring to these directories, users have their own
2520 @dfn{profile}, which points to the packages that they actually want to
2521 use. These profiles are stored within each user's home directory, at
2522 @code{$HOME/.guix-profile}.
2524 For example, @code{alice} installs GCC 4.7.2. As a result,
2525 @file{/home/alice/.guix-profile/bin/gcc} points to
2526 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2527 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2528 simply continues to point to
2529 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2530 coexist on the same system without any interference.
2532 The @command{guix package} command is the central tool to manage
2533 packages (@pxref{Invoking guix package}). It operates on the per-user
2534 profiles, and can be used @emph{with normal user privileges}.
2536 @cindex transactions
2537 The command provides the obvious install, remove, and upgrade
2538 operations. Each invocation is actually a @emph{transaction}: either
2539 the specified operation succeeds, or nothing happens. Thus, if the
2540 @command{guix package} process is terminated during the transaction,
2541 or if a power outage occurs during the transaction, then the user's
2542 profile remains in its previous state, and remains usable.
2544 In addition, any package transaction may be @emph{rolled back}. So, if,
2545 for example, an upgrade installs a new version of a package that turns
2546 out to have a serious bug, users may roll back to the previous instance
2547 of their profile, which was known to work well. Similarly, the global
2548 system configuration on Guix is subject to
2549 transactional upgrades and roll-back
2550 (@pxref{Using the Configuration System}).
2552 All packages in the package store may be @emph{garbage-collected}.
2553 Guix can determine which packages are still referenced by user
2554 profiles, and remove those that are provably no longer referenced
2555 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2556 generations of their profile so that the packages they refer to can be
2559 @cindex reproducibility
2560 @cindex reproducible builds
2561 Guix takes a @dfn{purely functional} approach to package
2562 management, as described in the introduction (@pxref{Introduction}).
2563 Each @file{/gnu/store} package directory name contains a hash of all the
2564 inputs that were used to build that package---compiler, libraries, build
2565 scripts, etc. This direct correspondence allows users to make sure a
2566 given package installation matches the current state of their
2567 distribution. It also helps maximize @dfn{build reproducibility}:
2568 thanks to the isolated build environments that are used, a given build
2569 is likely to yield bit-identical files when performed on different
2570 machines (@pxref{Invoking guix-daemon, container}).
2573 This foundation allows Guix to support @dfn{transparent binary/source
2574 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2575 available from an external source---a @dfn{substitute}, Guix just
2576 downloads it and unpacks it;
2577 otherwise, it builds the package from source, locally
2578 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2579 reproducible, users do not have to trust servers that provide
2580 substitutes: they can force a local build and @emph{challenge} providers
2581 (@pxref{Invoking guix challenge}).
2583 Control over the build environment is a feature that is also useful for
2584 developers. The @command{guix environment} command allows developers of
2585 a package to quickly set up the right development environment for their
2586 package, without having to manually install the dependencies of the
2587 package into their profile (@pxref{Invoking guix environment}).
2589 @cindex replication, of software environments
2590 @cindex provenance tracking, of software artifacts
2591 All of Guix and its package definitions is version-controlled, and
2592 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2593 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2594 Guix instance on a different machine or at a later point in time, which in
2595 turn allows you to @emph{replicate complete software environments}, while
2596 retaining precise @dfn{provenance tracking} of the software.
2598 @node Invoking guix package
2599 @section Invoking @command{guix package}
2601 @cindex installing packages
2602 @cindex removing packages
2603 @cindex package installation
2604 @cindex package removal
2605 The @command{guix package} command is the tool that allows users to
2606 install, upgrade, and remove packages, as well as rolling back to
2607 previous configurations. It operates only on the user's own profile,
2608 and works with normal user privileges (@pxref{Features}). Its syntax
2612 guix package @var{options}
2615 @cindex transactions
2616 Primarily, @var{options} specifies the operations to be performed during
2617 the transaction. Upon completion, a new profile is created, but
2618 previous @dfn{generations} of the profile remain available, should the user
2621 For example, to remove @code{lua} and install @code{guile} and
2622 @code{guile-cairo} in a single transaction:
2625 guix package -r lua -i guile guile-cairo
2628 @cindex aliases, for @command{guix package}
2629 For your convenience, we also provide the following aliases:
2633 @command{guix install} is an alias for @command{guix package -i},
2635 @command{guix remove} is an alias for @command{guix package -r},
2637 and @command{guix upgrade} is an alias for @command{guix package -u}.
2640 These aliases are less expressive than @command{guix package} and provide
2641 fewer options, so in some cases you'll probably want to use @command{guix
2644 @command{guix package} also supports a @dfn{declarative approach}
2645 whereby the user specifies the exact set of packages to be available and
2646 passes it @i{via} the @option{--manifest} option
2647 (@pxref{profile-manifest, @option{--manifest}}).
2650 For each user, a symlink to the user's default profile is automatically
2651 created in @file{$HOME/.guix-profile}. This symlink always points to the
2652 current generation of the user's default profile. Thus, users can add
2653 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
2654 variable, and so on.
2655 @cindex search paths
2656 If you are not using Guix System, consider adding the
2657 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2658 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2659 shells get all the right environment variable definitions:
2662 GUIX_PROFILE="$HOME/.guix-profile" ; \
2663 source "$HOME/.guix-profile/etc/profile"
2666 In a multi-user setup, user profiles are stored in a place registered as
2667 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2668 to (@pxref{Invoking guix gc}). That directory is normally
2669 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2670 @var{localstatedir} is the value passed to @code{configure} as
2671 @code{--localstatedir}, and @var{user} is the user name. The
2672 @file{per-user} directory is created when @command{guix-daemon} is
2673 started, and the @var{user} sub-directory is created by @command{guix
2676 The @var{options} can be among the following:
2680 @item --install=@var{package} @dots{}
2681 @itemx -i @var{package} @dots{}
2682 Install the specified @var{package}s.
2684 Each @var{package} may specify either a simple package name, such as
2685 @code{guile}, or a package name followed by an at-sign and version number,
2686 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2687 case, the newest version prefixed by @code{1.8} is selected.)
2689 If no version number is specified, the
2690 newest available version will be selected. In addition, @var{package}
2691 may contain a colon, followed by the name of one of the outputs of the
2692 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2693 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2694 name (and optionally version) are searched for among the GNU
2695 distribution modules (@pxref{Package Modules}).
2697 @cindex propagated inputs
2698 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2699 that automatically get installed along with the required package
2700 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2701 @code{package} objects}, for information about propagated inputs in
2702 package definitions).
2704 @anchor{package-cmd-propagated-inputs}
2705 An example is the GNU MPC library: its C header files refer to those of
2706 the GNU MPFR library, which in turn refer to those of the GMP library.
2707 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2708 in the profile; removing MPC also removes MPFR and GMP---unless they had
2709 also been explicitly installed by the user.
2711 Besides, packages sometimes rely on the definition of environment
2712 variables for their search paths (see explanation of
2713 @code{--search-paths} below). Any missing or possibly incorrect
2714 environment variable definitions are reported here.
2716 @item --install-from-expression=@var{exp}
2718 Install the package @var{exp} evaluates to.
2720 @var{exp} must be a Scheme expression that evaluates to a
2721 @code{<package>} object. This option is notably useful to disambiguate
2722 between same-named variants of a package, with expressions such as
2723 @code{(@@ (gnu packages base) guile-final)}.
2725 Note that this option installs the first output of the specified
2726 package, which may be insufficient when needing a specific output of a
2727 multiple-output package.
2729 @item --install-from-file=@var{file}
2730 @itemx -f @var{file}
2731 Install the package that the code within @var{file} evaluates to.
2733 As an example, @var{file} might contain a definition like this
2734 (@pxref{Defining Packages}):
2737 @verbatiminclude package-hello.scm
2740 Developers may find it useful to include such a @file{guix.scm} file
2741 in the root of their project source tree that can be used to test
2742 development snapshots and create reproducible development environments
2743 (@pxref{Invoking guix environment}).
2745 @item --remove=@var{package} @dots{}
2746 @itemx -r @var{package} @dots{}
2747 Remove the specified @var{package}s.
2749 As for @code{--install}, each @var{package} may specify a version number
2750 and/or output name in addition to the package name. For instance,
2751 @code{-r glibc:debug} would remove the @code{debug} output of
2754 @item --upgrade[=@var{regexp} @dots{}]
2755 @itemx -u [@var{regexp} @dots{}]
2756 @cindex upgrading packages
2757 Upgrade all the installed packages. If one or more @var{regexp}s are
2758 specified, upgrade only installed packages whose name matches a
2759 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2761 Note that this upgrades package to the latest version of packages found
2762 in the distribution currently installed. To update your distribution,
2763 you should regularly run @command{guix pull} (@pxref{Invoking guix
2766 @item --do-not-upgrade[=@var{regexp} @dots{}]
2767 When used together with the @code{--upgrade} option, do @emph{not}
2768 upgrade any packages whose name matches a @var{regexp}. For example, to
2769 upgrade all packages in the current profile except those containing the
2770 substring ``emacs'':
2773 $ guix package --upgrade . --do-not-upgrade emacs
2776 @item @anchor{profile-manifest}--manifest=@var{file}
2777 @itemx -m @var{file}
2778 @cindex profile declaration
2779 @cindex profile manifest
2780 Create a new generation of the profile from the manifest object
2781 returned by the Scheme code in @var{file}.
2783 This allows you to @emph{declare} the profile's contents rather than
2784 constructing it through a sequence of @code{--install} and similar
2785 commands. The advantage is that @var{file} can be put under version
2786 control, copied to different machines to reproduce the same profile, and
2789 @c FIXME: Add reference to (guix profile) documentation when available.
2790 @var{file} must return a @dfn{manifest} object, which is roughly a list
2793 @findex packages->manifest
2795 (use-package-modules guile emacs)
2800 ;; Use a specific package output.
2801 (list guile-2.0 "debug")))
2804 @findex specifications->manifest
2805 In this example we have to know which modules define the @code{emacs}
2806 and @code{guile-2.0} variables to provide the right
2807 @code{use-package-modules} line, which can be cumbersome. We can
2808 instead provide regular package specifications and let
2809 @code{specifications->manifest} look up the corresponding package
2813 (specifications->manifest
2814 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2818 @cindex rolling back
2819 @cindex undoing transactions
2820 @cindex transactions, undoing
2821 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2822 the last transaction.
2824 When combined with options such as @code{--install}, roll back occurs
2825 before any other actions.
2827 When rolling back from the first generation that actually contains
2828 installed packages, the profile is made to point to the @dfn{zeroth
2829 generation}, which contains no files apart from its own metadata.
2831 After having rolled back, installing, removing, or upgrading packages
2832 overwrites previous future generations. Thus, the history of the
2833 generations in a profile is always linear.
2835 @item --switch-generation=@var{pattern}
2836 @itemx -S @var{pattern}
2838 Switch to a particular generation defined by @var{pattern}.
2840 @var{pattern} may be either a generation number or a number prefixed
2841 with ``+'' or ``-''. The latter means: move forward/backward by a
2842 specified number of generations. For example, if you want to return to
2843 the latest generation after @code{--roll-back}, use
2844 @code{--switch-generation=+1}.
2846 The difference between @code{--roll-back} and
2847 @code{--switch-generation=-1} is that @code{--switch-generation} will
2848 not make a zeroth generation, so if a specified generation does not
2849 exist, the current generation will not be changed.
2851 @item --search-paths[=@var{kind}]
2852 @cindex search paths
2853 Report environment variable definitions, in Bash syntax, that may be
2854 needed in order to use the set of installed packages. These environment
2855 variables are used to specify @dfn{search paths} for files used by some
2856 of the installed packages.
2858 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2859 environment variables to be defined so it can look for headers and
2860 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2861 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2862 library are installed in the profile, then @code{--search-paths} will
2863 suggest setting these variables to @code{@var{profile}/include} and
2864 @code{@var{profile}/lib}, respectively.
2866 The typical use case is to define these environment variables in the
2870 $ eval `guix package --search-paths`
2873 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2874 meaning that the returned environment variable definitions will either
2875 be exact settings, or prefixes or suffixes of the current value of these
2876 variables. When omitted, @var{kind} defaults to @code{exact}.
2878 This option can also be used to compute the @emph{combined} search paths
2879 of several profiles. Consider this example:
2882 $ guix package -p foo -i guile
2883 $ guix package -p bar -i guile-json
2884 $ guix package -p foo -p bar --search-paths
2887 The last command above reports about the @code{GUILE_LOAD_PATH}
2888 variable, even though, taken individually, neither @file{foo} nor
2889 @file{bar} would lead to that recommendation.
2892 @item --profile=@var{profile}
2893 @itemx -p @var{profile}
2894 Use @var{profile} instead of the user's default profile.
2896 @cindex collisions, in a profile
2897 @cindex colliding packages in profiles
2898 @cindex profile collisions
2899 @item --allow-collisions
2900 Allow colliding packages in the new profile. Use at your own risk!
2902 By default, @command{guix package} reports as an error @dfn{collisions}
2903 in the profile. Collisions happen when two or more different versions
2904 or variants of a given package end up in the profile.
2907 Use the bootstrap Guile to build the profile. This option is only
2908 useful to distribution developers.
2912 In addition to these actions, @command{guix package} supports the
2913 following options to query the current state of a profile, or the
2914 availability of packages:
2918 @item --search=@var{regexp}
2919 @itemx -s @var{regexp}
2920 @cindex searching for packages
2921 List the available packages whose name, synopsis, or description matches
2922 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
2923 Print all the metadata of matching packages in
2924 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
2925 GNU recutils manual}).
2927 This allows specific fields to be extracted using the @command{recsel}
2928 command, for instance:
2931 $ guix package -s malloc | recsel -p name,version,relevance
2945 Similarly, to show the name of all the packages available under the
2946 terms of the GNU@tie{}LGPL version 3:
2949 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
2956 It is also possible to refine search results using several @code{-s}
2957 flags. For example, the following command returns a list of board
2961 $ guix package -s '\<board\>' -s game | recsel -p name
2966 If we were to omit @code{-s game}, we would also get software packages
2967 that deal with printed circuit boards; removing the angle brackets
2968 around @code{board} would further add packages that have to do with
2971 And now for a more elaborate example. The following command searches
2972 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
2973 libraries, and prints the name and synopsis of the matching packages:
2976 $ guix package -s crypto -s library | \
2977 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
2981 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
2982 information on @dfn{selection expressions} for @code{recsel -e}.
2984 @item --show=@var{package}
2985 Show details about @var{package}, taken from the list of available packages, in
2986 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
2990 $ guix package --show=python | recsel -p name,version
2998 You may also specify the full name of a package to only get details about a
2999 specific version of it:
3001 $ guix package --show=python@@3.4 | recsel -p name,version
3008 @item --list-installed[=@var{regexp}]
3009 @itemx -I [@var{regexp}]
3010 List the currently installed packages in the specified profile, with the
3011 most recently installed packages shown last. When @var{regexp} is
3012 specified, list only installed packages whose name matches @var{regexp}.
3014 For each installed package, print the following items, separated by
3015 tabs: the package name, its version string, the part of the package that
3016 is installed (for instance, @code{out} for the default output,
3017 @code{include} for its headers, etc.), and the path of this package in
3020 @item --list-available[=@var{regexp}]
3021 @itemx -A [@var{regexp}]
3022 List packages currently available in the distribution for this system
3023 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3024 installed packages whose name matches @var{regexp}.
3026 For each package, print the following items separated by tabs: its name,
3027 its version string, the parts of the package (@pxref{Packages with
3028 Multiple Outputs}), and the source location of its definition.
3030 @item --list-generations[=@var{pattern}]
3031 @itemx -l [@var{pattern}]
3033 Return a list of generations along with their creation dates; for each
3034 generation, show the installed packages, with the most recently
3035 installed packages shown last. Note that the zeroth generation is never
3038 For each installed package, print the following items, separated by
3039 tabs: the name of a package, its version string, the part of the package
3040 that is installed (@pxref{Packages with Multiple Outputs}), and the
3041 location of this package in the store.
3043 When @var{pattern} is used, the command returns only matching
3044 generations. Valid patterns include:
3047 @item @emph{Integers and comma-separated integers}. Both patterns denote
3048 generation numbers. For instance, @code{--list-generations=1} returns
3051 And @code{--list-generations=1,8,2} outputs three generations in the
3052 specified order. Neither spaces nor trailing commas are allowed.
3054 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
3055 specified generations and everything in between. Note that the start of
3056 a range must be smaller than its end.
3058 It is also possible to omit the endpoint. For example,
3059 @code{--list-generations=2..}, returns all generations starting from the
3062 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3063 or months by passing an integer along with the first letter of the
3064 duration. For example, @code{--list-generations=20d} lists generations
3065 that are up to 20 days old.
3068 @item --delete-generations[=@var{pattern}]
3069 @itemx -d [@var{pattern}]
3070 When @var{pattern} is omitted, delete all generations except the current
3073 This command accepts the same patterns as @option{--list-generations}.
3074 When @var{pattern} is specified, delete the matching generations. When
3075 @var{pattern} specifies a duration, generations @emph{older} than the
3076 specified duration match. For instance, @code{--delete-generations=1m}
3077 deletes generations that are more than one month old.
3079 If the current generation matches, it is @emph{not} deleted. Also, the
3080 zeroth generation is never deleted.
3082 Note that deleting generations prevents rolling back to them.
3083 Consequently, this command must be used with care.
3087 Finally, since @command{guix package} may actually start build
3088 processes, it supports all the common build options (@pxref{Common Build
3089 Options}). It also supports package transformation options, such as
3090 @option{--with-source} (@pxref{Package Transformation Options}).
3091 However, note that package transformations are lost when upgrading; to
3092 preserve transformations across upgrades, you should define your own
3093 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
3094 (@pxref{Defining Packages}).
3097 @section Substitutes
3100 @cindex pre-built binaries
3101 Guix supports transparent source/binary deployment, which means that it
3102 can either build things locally, or download pre-built items from a
3103 server, or both. We call these pre-built items @dfn{substitutes}---they
3104 are substitutes for local build results. In many cases, downloading a
3105 substitute is much faster than building things locally.
3107 Substitutes can be anything resulting from a derivation build
3108 (@pxref{Derivations}). Of course, in the common case, they are
3109 pre-built package binaries, but source tarballs, for instance, which
3110 also result from derivation builds, can be available as substitutes.
3113 * Official Substitute Server:: One particular source of substitutes.
3114 * Substitute Server Authorization:: How to enable or disable substitutes.
3115 * Substitute Authentication:: How Guix verifies substitutes.
3116 * Proxy Settings:: How to get substitutes via proxy.
3117 * Substitution Failure:: What happens when substitution fails.
3118 * On Trusting Binaries:: How can you trust that binary blob?
3121 @node Official Substitute Server
3122 @subsection Official Substitute Server
3126 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3127 that builds packages from Guix continuously for some
3128 architectures, and makes them available as substitutes. This is the
3129 default source of substitutes; it can be overridden by passing the
3130 @option{--substitute-urls} option either to @command{guix-daemon}
3131 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3132 or to client tools such as @command{guix package}
3133 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3136 Substitute URLs can be either HTTP or HTTPS.
3137 HTTPS is recommended because communications are encrypted; conversely,
3138 using HTTP makes all communications visible to an eavesdropper, who
3139 could use the information gathered to determine, for instance, whether
3140 your system has unpatched security vulnerabilities.
3142 Substitutes from the official build farm are enabled by default when
3143 using Guix System (@pxref{GNU Distribution}). However,
3144 they are disabled by default when using Guix on a foreign distribution,
3145 unless you have explicitly enabled them via one of the recommended
3146 installation steps (@pxref{Installation}). The following paragraphs
3147 describe how to enable or disable substitutes for the official build
3148 farm; the same procedure can also be used to enable substitutes for any
3149 other substitute server.
3151 @node Substitute Server Authorization
3152 @subsection Substitute Server Authorization
3155 @cindex substitutes, authorization thereof
3156 @cindex access control list (ACL), for substitutes
3157 @cindex ACL (access control list), for substitutes
3158 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3160 must add its public key to the access control list (ACL) of archive
3161 imports, using the @command{guix archive} command (@pxref{Invoking guix
3162 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3163 be compromised and to serve genuine substitutes.
3165 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3166 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3167 the installation prefix of Guix. If you installed Guix from source,
3168 make sure you checked the GPG signature of
3169 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3170 Then, you can run something like this:
3173 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3177 Similarly, the @file{hydra.gnu.org.pub} file contains the public key
3178 of an independent build farm also run by the project, reachable at
3179 @indicateurl{https://mirror.hydra.gnu.org}.
3182 Once this is in place, the output of a command like @code{guix build}
3183 should change from something like:
3186 $ guix build emacs --dry-run
3187 The following derivations would be built:
3188 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3189 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3190 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3191 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3199 $ guix build emacs --dry-run
3200 112.3 MB would be downloaded:
3201 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3202 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3203 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3204 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3209 This indicates that substitutes from @code{@value{SUBSTITUTE-SERVER}} are usable and
3210 will be downloaded, when possible, for future builds.
3212 @cindex substitutes, how to disable
3213 The substitute mechanism can be disabled globally by running
3214 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
3215 guix-daemon}). It can also be disabled temporarily by passing the
3216 @code{--no-substitutes} option to @command{guix package}, @command{guix
3217 build}, and other command-line tools.
3219 @node Substitute Authentication
3220 @subsection Substitute Authentication
3222 @cindex digital signatures
3223 Guix detects and raises an error when attempting to use a substitute
3224 that has been tampered with. Likewise, it ignores substitutes that are
3225 not signed, or that are not signed by one of the keys listed in the ACL.
3227 There is one exception though: if an unauthorized server provides
3228 substitutes that are @emph{bit-for-bit identical} to those provided by
3229 an authorized server, then the unauthorized server becomes eligible for
3230 downloads. For example, assume we have chosen two substitute servers
3234 --substitute-urls="https://a.example.org https://b.example.org"
3238 @cindex reproducible builds
3239 If the ACL contains only the key for @code{b.example.org}, and if
3240 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
3241 then Guix will download substitutes from @code{a.example.org} because it
3242 comes first in the list and can be considered a mirror of
3243 @code{b.example.org}. In practice, independent build machines usually
3244 produce the same binaries, thanks to bit-reproducible builds (see
3247 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3248 (in other words, the server is not authenticated), contrary to what
3249 HTTPS clients such as Web browsers usually do. This is because Guix
3250 authenticates substitute information itself, as explained above, which
3251 is what we care about (whereas X.509 certificates are about
3252 authenticating bindings between domain names and public keys.)
3254 @node Proxy Settings
3255 @subsection Proxy Settings
3258 Substitutes are downloaded over HTTP or HTTPS.
3259 The @code{http_proxy} environment
3260 variable can be set in the environment of @command{guix-daemon} and is
3261 honored for downloads of substitutes. Note that the value of
3262 @code{http_proxy} in the environment where @command{guix build},
3263 @command{guix package}, and other client commands are run has
3264 @emph{absolutely no effect}.
3266 @node Substitution Failure
3267 @subsection Substitution Failure
3269 Even when a substitute for a derivation is available, sometimes the
3270 substitution attempt will fail. This can happen for a variety of
3271 reasons: the substitute server might be offline, the substitute may
3272 recently have been deleted, the connection might have been interrupted,
3275 When substitutes are enabled and a substitute for a derivation is
3276 available, but the substitution attempt fails, Guix will attempt to
3277 build the derivation locally depending on whether or not
3278 @code{--fallback} was given (@pxref{fallback-option,, common build
3279 option @code{--fallback}}). Specifically, if @code{--fallback} was
3280 omitted, then no local build will be performed, and the derivation is
3281 considered to have failed. However, if @code{--fallback} was given,
3282 then Guix will attempt to build the derivation locally, and the success
3283 or failure of the derivation depends on the success or failure of the
3284 local build. Note that when substitutes are disabled or no substitute
3285 is available for the derivation in question, a local build will
3286 @emph{always} be performed, regardless of whether or not
3287 @code{--fallback} was given.
3289 To get an idea of how many substitutes are available right now, you can
3290 try running the @command{guix weather} command (@pxref{Invoking guix
3291 weather}). This command provides statistics on the substitutes provided
3294 @node On Trusting Binaries
3295 @subsection On Trusting Binaries
3297 @cindex trust, of pre-built binaries
3298 Today, each individual's control over their own computing is at the
3299 mercy of institutions, corporations, and groups with enough power and
3300 determination to subvert the computing infrastructure and exploit its
3301 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3302 convenient, we encourage users to also build on their own, or even run
3303 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3304 interesting target. One way to help is by publishing the software you
3305 build using @command{guix publish} so that others have one more choice
3306 of server to download substitutes from (@pxref{Invoking guix publish}).
3308 Guix has the foundations to maximize build reproducibility
3309 (@pxref{Features}). In most cases, independent builds of a given
3310 package or derivation should yield bit-identical results. Thus, through
3311 a diverse set of independent package builds, we can strengthen the
3312 integrity of our systems. The @command{guix challenge} command aims to
3313 help users assess substitute servers, and to assist developers in
3314 finding out about non-deterministic package builds (@pxref{Invoking guix
3315 challenge}). Similarly, the @option{--check} option of @command{guix
3316 build} allows users to check whether previously-installed substitutes
3317 are genuine by rebuilding them locally (@pxref{build-check,
3318 @command{guix build --check}}).
3320 In the future, we want Guix to have support to publish and retrieve
3321 binaries to/from other users, in a peer-to-peer fashion. If you would
3322 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3324 @node Packages with Multiple Outputs
3325 @section Packages with Multiple Outputs
3327 @cindex multiple-output packages
3328 @cindex package outputs
3331 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3332 source package leads to exactly one directory in the store. When running
3333 @command{guix install glibc}, one installs the default output of the
3334 GNU libc package; the default output is called @code{out}, but its name
3335 can be omitted as shown in this command. In this particular case, the
3336 default output of @code{glibc} contains all the C header files, shared
3337 libraries, static libraries, Info documentation, and other supporting
3340 Sometimes it is more appropriate to separate the various types of files
3341 produced from a single source package into separate outputs. For
3342 instance, the GLib C library (used by GTK+ and related packages)
3343 installs more than 20 MiB of reference documentation as HTML pages.
3344 To save space for users who do not need it, the documentation goes to a
3345 separate output, called @code{doc}. To install the main GLib output,
3346 which contains everything but the documentation, one would run:
3352 @cindex documentation
3353 The command to install its documentation is:
3356 guix install glib:doc
3359 Some packages install programs with different ``dependency footprints''.
3360 For instance, the WordNet package installs both command-line tools and
3361 graphical user interfaces (GUIs). The former depend solely on the C
3362 library, whereas the latter depend on Tcl/Tk and the underlying X
3363 libraries. In this case, we leave the command-line tools in the default
3364 output, whereas the GUIs are in a separate output. This allows users
3365 who do not need the GUIs to save space. The @command{guix size} command
3366 can help find out about such situations (@pxref{Invoking guix size}).
3367 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3369 There are several such multiple-output packages in the GNU distribution.
3370 Other conventional output names include @code{lib} for libraries and
3371 possibly header files, @code{bin} for stand-alone programs, and
3372 @code{debug} for debugging information (@pxref{Installing Debugging
3373 Files}). The outputs of a packages are listed in the third column of
3374 the output of @command{guix package --list-available} (@pxref{Invoking
3378 @node Invoking guix gc
3379 @section Invoking @command{guix gc}
3381 @cindex garbage collector
3383 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3384 The @command{guix gc} command allows users to explicitly run the garbage
3385 collector to reclaim space from the @file{/gnu/store} directory. It is
3386 the @emph{only} way to remove files from @file{/gnu/store}---removing
3387 files or directories manually may break it beyond repair!
3390 @cindex garbage collector roots
3391 The garbage collector has a set of known @dfn{roots}: any file under
3392 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3393 cannot be deleted; any other file is considered @dfn{dead} and may be
3394 deleted. The set of garbage collector roots (``GC roots'' for short)
3395 includes default user profiles; by default, the symlinks under
3396 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3397 added with @command{guix build --root}, for example (@pxref{Invoking
3398 guix build}). The @command{guix gc --list-roots} command lists them.
3400 Prior to running @code{guix gc --collect-garbage} to make space, it is
3401 often useful to remove old generations from user profiles; that way, old
3402 package builds referenced by those generations can be reclaimed. This
3403 is achieved by running @code{guix package --delete-generations}
3404 (@pxref{Invoking guix package}).
3406 Our recommendation is to run a garbage collection periodically, or when
3407 you are short on disk space. For instance, to guarantee that at least
3408 5@tie{}GB are available on your disk, simply run:
3414 It is perfectly safe to run as a non-interactive periodic job
3415 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3416 Running @command{guix gc} with no arguments will collect as
3417 much garbage as it can, but that is often inconvenient: you may find
3418 yourself having to rebuild or re-download software that is ``dead'' from
3419 the GC viewpoint but that is necessary to build other pieces of
3420 software---e.g., the compiler tool chain.
3422 The @command{guix gc} command has three modes of operation: it can be
3423 used to garbage-collect any dead files (the default), to delete specific
3424 files (the @code{--delete} option), to print garbage-collector
3425 information, or for more advanced queries. The garbage collection
3426 options are as follows:
3429 @item --collect-garbage[=@var{min}]
3430 @itemx -C [@var{min}]
3431 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3432 sub-directories. This is the default operation when no option is
3435 When @var{min} is given, stop once @var{min} bytes have been collected.
3436 @var{min} may be a number of bytes, or it may include a unit as a
3437 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3438 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3440 When @var{min} is omitted, collect all the garbage.
3442 @item --free-space=@var{free}
3443 @itemx -F @var{free}
3444 Collect garbage until @var{free} space is available under
3445 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3446 as @code{500MiB}, as described above.
3448 When @var{free} or more is already available in @file{/gnu/store}, do
3449 nothing and exit immediately.
3451 @item --delete-generations[=@var{duration}]
3452 @itemx -d [@var{duration}]
3453 Before starting the garbage collection process, delete all the generations
3454 older than @var{duration}, for all the user profiles; when run as root, this
3455 applies to all the profiles @emph{of all the users}.
3457 For example, this command deletes all the generations of all your profiles
3458 that are older than 2 months (except generations that are current), and then
3459 proceeds to free space until at least 10 GiB are available:
3462 guix gc -d 2m -F 10G
3467 Attempt to delete all the store files and directories specified as
3468 arguments. This fails if some of the files are not in the store, or if
3469 they are still live.
3471 @item --list-failures
3472 List store items corresponding to cached build failures.
3474 This prints nothing unless the daemon was started with
3475 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3476 @option{--cache-failures}}).
3479 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3482 @item --clear-failures
3483 Remove the specified store items from the failed-build cache.
3485 Again, this option only makes sense when the daemon is started with
3486 @option{--cache-failures}. Otherwise, it does nothing.
3489 Show the list of dead files and directories still present in the
3490 store---i.e., files and directories no longer reachable from any root.
3493 Show the list of live store files and directories.
3497 In addition, the references among existing store files can be queried:
3503 @cindex package dependencies
3504 List the references (respectively, the referrers) of store files given
3510 List the requisites of the store files passed as arguments. Requisites
3511 include the store files themselves, their references, and the references
3512 of these, recursively. In other words, the returned list is the
3513 @dfn{transitive closure} of the store files.
3515 @xref{Invoking guix size}, for a tool to profile the size of the closure
3516 of an element. @xref{Invoking guix graph}, for a tool to visualize
3517 the graph of references.
3521 Return the derivation(s) leading to the given store items
3522 (@pxref{Derivations}).
3524 For example, this command:
3527 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3531 returns the @file{.drv} file(s) leading to the @code{emacs} package
3532 installed in your profile.
3534 Note that there may be zero matching @file{.drv} files, for instance
3535 because these files have been garbage-collected. There can also be more
3536 than one matching @file{.drv} due to fixed-output derivations.
3539 Lastly, the following options allow you to check the integrity of the
3540 store and to control disk usage.
3544 @item --verify[=@var{options}]
3545 @cindex integrity, of the store
3546 @cindex integrity checking
3547 Verify the integrity of the store.
3549 By default, make sure that all the store items marked as valid in the
3550 database of the daemon actually exist in @file{/gnu/store}.
3552 When provided, @var{options} must be a comma-separated list containing one
3553 or more of @code{contents} and @code{repair}.
3555 When passing @option{--verify=contents}, the daemon computes the
3556 content hash of each store item and compares it against its hash in the
3557 database. Hash mismatches are reported as data corruptions. Because it
3558 traverses @emph{all the files in the store}, this command can take a
3559 long time, especially on systems with a slow disk drive.
3561 @cindex repairing the store
3562 @cindex corruption, recovering from
3563 Using @option{--verify=repair} or @option{--verify=contents,repair}
3564 causes the daemon to try to repair corrupt store items by fetching
3565 substitutes for them (@pxref{Substitutes}). Because repairing is not
3566 atomic, and thus potentially dangerous, it is available only to the
3567 system administrator. A lightweight alternative, when you know exactly
3568 which items in the store are corrupt, is @command{guix build --repair}
3569 (@pxref{Invoking guix build}).
3572 @cindex deduplication
3573 Optimize the store by hard-linking identical files---this is
3574 @dfn{deduplication}.
3576 The daemon performs deduplication after each successful build or archive
3577 import, unless it was started with @code{--disable-deduplication}
3578 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
3579 this option is primarily useful when the daemon was running with
3580 @code{--disable-deduplication}.
3584 @node Invoking guix pull
3585 @section Invoking @command{guix pull}
3587 @cindex upgrading Guix
3588 @cindex updating Guix
3589 @cindex @command{guix pull}
3591 Packages are installed or upgraded to the latest version available in
3592 the distribution currently available on your local machine. To update
3593 that distribution, along with the Guix tools, you must run @command{guix
3594 pull}: the command downloads the latest Guix source code and package
3595 descriptions, and deploys it. Source code is downloaded from a
3596 @uref{https://git-scm.com, Git} repository, by default the official
3597 GNU@tie{}Guix repository, though this can be customized.
3599 On completion, @command{guix package} will use packages and package
3600 versions from this just-retrieved copy of Guix. Not only that, but all
3601 the Guix commands and Scheme modules will also be taken from that latest
3602 version. New @command{guix} sub-commands added by the update also
3605 Any user can update their Guix copy using @command{guix pull}, and the
3606 effect is limited to the user who run @command{guix pull}. For
3607 instance, when user @code{root} runs @command{guix pull}, this has no
3608 effect on the version of Guix that user @code{alice} sees, and vice
3611 The result of running @command{guix pull} is a @dfn{profile} available
3612 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3613 make sure to add it to the beginning of your search path so that you use
3614 the latest version, and similarly for the Info manual
3615 (@pxref{Documentation}):
3618 export PATH="$HOME/.config/guix/current/bin:$PATH"
3619 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3622 The @code{--list-generations} or @code{-l} option lists past generations
3623 produced by @command{guix pull}, along with details about their provenance:
3627 Generation 1 Jun 10 2018 00:18:18
3629 repository URL: https://git.savannah.gnu.org/git/guix.git
3630 branch: origin/master
3631 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3633 Generation 2 Jun 11 2018 11:02:49
3635 repository URL: https://git.savannah.gnu.org/git/guix.git
3636 branch: origin/master
3637 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3638 2 new packages: keepalived, libnfnetlink
3639 6 packages upgraded: emacs-nix-mode@@2.0.4,
3640 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3641 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3643 Generation 3 Jun 13 2018 23:31:07 (current)
3645 repository URL: https://git.savannah.gnu.org/git/guix.git
3646 branch: origin/master
3647 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3648 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3649 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3652 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3653 describe the current status of Guix.
3655 This @code{~/.config/guix/current} profile works like any other profile
3656 created by @command{guix package} (@pxref{Invoking guix package}). That
3657 is, you can list generations, roll back to the previous
3658 generation---i.e., the previous Guix---and so on:
3661 $ guix package -p ~/.config/guix/current --roll-back
3662 switched from generation 3 to 2
3663 $ guix package -p ~/.config/guix/current --delete-generations=1
3664 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3667 The @command{guix pull} command is usually invoked with no arguments,
3668 but it supports the following options:
3671 @item --url=@var{url}
3672 @itemx --commit=@var{commit}
3673 @itemx --branch=@var{branch}
3674 Download code for the @code{guix} channel from the specified @var{url}, at the
3675 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3676 string), or @var{branch}.
3678 @cindex @file{channels.scm}, configuration file
3679 @cindex configuration file for channels
3680 These options are provided for convenience, but you can also specify your
3681 configuration in the @file{~/.config/guix/channels.scm} file or using the
3682 @option{--channels} option (see below).
3684 @item --channels=@var{file}
3685 @itemx -C @var{file}
3686 Read the list of channels from @var{file} instead of
3687 @file{~/.config/guix/channels.scm}. @var{file} must contain Scheme code that
3688 evaluates to a list of channel objects. @xref{Channels}, for more
3693 Display the list of packages added or upgraded since the previous generation.
3695 This is the same information as displayed upon @command{guix pull} completion,
3696 but without ellipses; it is also similar to the output of @command{guix pull
3697 -l} for the last generation (see below).
3699 @item --list-generations[=@var{pattern}]
3700 @itemx -l [@var{pattern}]
3701 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3702 is provided, the subset of generations that match @var{pattern}.
3703 The syntax of @var{pattern} is the same as with @code{guix package
3704 --list-generations} (@pxref{Invoking guix package}).
3706 @xref{Invoking guix describe}, for a way to display information about the
3707 current generation only.
3709 @item --profile=@var{profile}
3710 @itemx -p @var{profile}
3711 Use @var{profile} instead of @file{~/.config/guix/current}.
3715 Show which channel commit(s) would be used and what would be built or
3716 substituted but do not actually do it.
3718 @item --system=@var{system}
3719 @itemx -s @var{system}
3720 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3721 the system type of the build host.
3724 Produce verbose output, writing build logs to the standard error output.
3727 Use the bootstrap Guile to build the latest Guix. This option is only
3728 useful to Guix developers.
3731 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3732 repository and branch to pull from, as well as @emph{additional} repositories
3733 containing package modules that should be deployed. @xref{Channels}, for more
3736 In addition, @command{guix pull} supports all the common build options
3737 (@pxref{Common Build Options}).
3743 @cindex @file{channels.scm}, configuration file
3744 @cindex configuration file for channels
3745 @cindex @command{guix pull}, configuration file
3746 @cindex configuration of @command{guix pull}
3747 Guix and its package collection are updated by running @command{guix pull}
3748 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3749 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3750 customized by defining @dfn{channels} in the
3751 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3752 of a Git repository to be deployed, and @command{guix pull} can be instructed
3753 to pull from one or more channels. In other words, channels can be used to
3754 @emph{customize} and to @emph{extend} Guix, as we will see below.
3756 @subsection Using a Custom Guix Channel
3758 The channel called @code{guix} specifies where Guix itself---its command-line
3759 tools as well as its package collection---should be downloaded. For instance,
3760 suppose you want to update from your own copy of the Guix repository at
3761 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3762 write in @code{~/.config/guix/channels.scm} this specification:
3765 ;; Tell 'guix pull' to use my own repo.
3768 (url "https://example.org/my-guix.git")
3769 (branch "super-hacks")))
3773 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3774 branch of the repository at @code{example.org}.
3776 @subsection Specifying Additional Channels
3778 @cindex extending the package collection (channels)
3779 @cindex personal packages (channels)
3780 @cindex channels, for personal packages
3781 You can also specify @emph{additional channels} to pull from. Let's say you
3782 have a bunch of custom package variants or personal packages that you think
3783 would make little sense to contribute to the Guix project, but would like to
3784 have these packages transparently available to you at the command line. You
3785 would first write modules containing those package definitions (@pxref{Package
3786 Modules}), maintain them in a Git repository, and then you and anyone else can
3787 use it as an additional channel to get packages from. Neat, no?
3789 @c What follows stems from discussions at
3790 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3791 @c earlier discussions on guix-devel@gnu.org.
3793 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3794 publish your personal channel to the world, we would like to share a few words
3799 Before publishing a channel, please consider contributing your package
3800 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3801 to free software of all sorts, and packages in Guix proper are readily
3802 available to all Guix users and benefit from the project's quality assurance
3806 When you maintain package definitions outside Guix, we, Guix developers,
3807 consider that @emph{the compatibility burden is on you}. Remember that
3808 package modules and package definitions are just Scheme code that uses various
3809 programming interfaces (APIs). We want to remain free to change these APIs to
3810 keep improving Guix, possibly in ways that break your channel. We never
3811 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3815 Corollary: if you're using an external channel and that channel breaks, please
3816 @emph{report the issue to the channel authors}, not to the Guix project.
3819 You've been warned! Having said this, we believe external channels are a
3820 practical way to exert your freedom to augment Guix' package collection and to
3821 share your improvements, which are basic tenets of
3822 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3823 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3826 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
3827 @command{guix pull} to pull from it @emph{in addition} to the default Guix
3830 @vindex %default-channels
3832 ;; Add my personal packages to those Guix provides.
3834 (name 'my-personal-packages)
3835 (url "https://example.org/personal-packages.git"))
3840 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3841 add a channel the list of channels that the variable @code{%default-channels}
3842 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3843 Manual}). With this file in place, @command{guix pull} builds not only Guix
3844 but also the package modules from your own repository. The result in
3845 @file{~/.config/guix/current} is the union of Guix with your own package
3849 $ guix pull --list-generations
3851 Generation 19 Aug 27 2018 16:20:48
3853 repository URL: https://git.savannah.gnu.org/git/guix.git
3855 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
3856 my-personal-packages dd3df5e
3857 repository URL: https://example.org/personal-packages.git
3859 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
3860 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
3861 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
3865 The output of @command{guix pull} above shows that Generation@tie{}19 includes
3866 both Guix and packages from the @code{my-personal-packages} channel. Among
3867 the new and upgraded packages that are listed, some like @code{my-gimp} and
3868 @code{my-emacs-with-cool-features} might come from
3869 @code{my-personal-packages}, while others come from the Guix default channel.
3871 To create a channel, create a Git repository containing your own package
3872 modules and make it available. The repository can contain anything, but a
3873 useful channel will contain Guile modules that export packages. Once you
3874 start using a channel, Guix will behave as if the root directory of that
3875 channel's Git repository has been added to the Guile load path (@pxref{Load
3876 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
3877 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
3878 module, then the module will be available under the name @code{(my-packages
3879 my-tools)}, and you will be able to use it like any other module
3880 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
3882 @cindex dependencies, channels
3883 @cindex meta-data, channels
3884 @subsection Declaring Channel Dependencies
3886 Channel authors may decide to augment a package collection provided by other
3887 channels. They can declare their channel to be dependent on other channels in
3888 a meta-data file @file{.guix-channel}, which is to be placed in the root of
3889 the channel repository.
3891 The meta-data file should contain a simple S-expression like this:
3898 (name some-collection)
3899 (url "https://example.org/first-collection.git"))
3901 (name some-other-collection)
3902 (url "https://example.org/second-collection.git")
3903 (branch "testing"))))
3906 In the above example this channel is declared to depend on two other channels,
3907 which will both be fetched automatically. The modules provided by the channel
3908 will be compiled in an environment where the modules of all these declared
3909 channels are available.
3911 For the sake of reliability and maintainability, you should avoid dependencies
3912 on channels that you don't control, and you should aim to keep the number of
3913 dependencies to a minimum.
3915 @subsection Replicating Guix
3917 @cindex pinning, channels
3918 @cindex replicating Guix
3919 @cindex reproducibility, of Guix
3920 The @command{guix pull --list-generations} output above shows precisely which
3921 commits were used to build this instance of Guix. We can thus replicate it,
3922 say, on another machine, by providing a channel specification in
3923 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
3926 ;; Deploy specific commits of my channels of interest.
3929 (url "https://git.savannah.gnu.org/git/guix.git")
3930 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
3932 (name 'my-personal-packages)
3933 (url "https://example.org/personal-packages.git")
3934 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
3937 The @command{guix describe --format=channels} command can even generate this
3938 list of channels directly (@pxref{Invoking guix describe}).
3940 At this point the two machines run the @emph{exact same Guix}, with access to
3941 the @emph{exact same packages}. The output of @command{guix build gimp} on
3942 one machine will be exactly the same, bit for bit, as the output of the same
3943 command on the other machine. It also means both machines have access to all
3944 the source code of Guix and, transitively, to all the source code of every
3947 This gives you super powers, allowing you to track the provenance of binary
3948 artifacts with very fine grain, and to reproduce software environments at
3949 will---some sort of ``meta reproducibility'' capabilities, if you will.
3950 @xref{Inferiors}, for another way to take advantage of these super powers.
3955 @c TODO: Remove this once we're more confident about API stability.
3957 The functionality described here is a ``technology preview'' as of version
3958 @value{VERSION}. As such, the interface is subject to change.
3962 @cindex composition of Guix revisions
3963 Sometimes you might need to mix packages from the revision of Guix you're
3964 currently running with packages available in a different revision of Guix.
3965 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
3966 revisions in arbitrary ways.
3968 @cindex inferior packages
3969 Technically, an ``inferior'' is essentially a separate Guix process connected
3970 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
3971 @code{(guix inferior)} module allows you to create inferiors and to
3972 communicate with them. It also provides a high-level interface to browse and
3973 manipulate the packages that an inferior provides---@dfn{inferior packages}.
3975 When combined with channels (@pxref{Channels}), inferiors provide a simple way
3976 to interact with a separate revision of Guix. For example, let's assume you
3977 want to install in your profile the current @code{guile} package, along with
3978 the @code{guile-json} as it existed in an older revision of Guix---perhaps
3979 because the newer @code{guile-json} has an incompatible API and you want to
3980 run your code against the old API@. To do that, you could write a manifest for
3981 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
3982 manifest, you would create an inferior for that old Guix revision you care
3983 about, and you would look up the @code{guile-json} package in the inferior:
3986 (use-modules (guix inferior) (guix channels)
3987 (srfi srfi-1)) ;for 'first'
3990 ;; This is the old revision from which we want to
3991 ;; extract guile-json.
3994 (url "https://git.savannah.gnu.org/git/guix.git")
3996 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
3999 ;; An inferior representing the above revision.
4000 (inferior-for-channels channels))
4002 ;; Now create a manifest with the current "guile" package
4003 ;; and the old "guile-json" package.
4005 (list (first (lookup-inferior-packages inferior "guile-json"))
4006 (specification->package "guile")))
4009 On its first run, @command{guix package --manifest} might have to build the
4010 channel you specified before it can create the inferior; subsequent runs will
4011 be much faster because the Guix revision will be cached.
4013 The @code{(guix inferior)} module provides the following procedures to open an
4016 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4017 [#:cache-directory] [#:ttl]
4018 Return an inferior for @var{channels}, a list of channels. Use the cache at
4019 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4020 This procedure opens a new connection to the build daemon.
4022 As a side effect, this procedure may build or substitute binaries for
4023 @var{channels}, which can take time.
4026 @deffn {Scheme Procedure} open-inferior @var{directory} @
4027 [#:command "bin/guix"]
4028 Open the inferior Guix in @var{directory}, running
4029 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4030 the inferior could not be launched.
4033 @cindex inferior packages
4034 The procedures listed below allow you to obtain and manipulate inferior
4037 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4038 Return the list of packages known to @var{inferior}.
4041 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4043 Return the sorted list of inferior packages matching @var{name} in
4044 @var{inferior}, with highest version numbers first. If @var{version} is true,
4045 return only packages with a version number prefixed by @var{version}.
4048 @deffn {Scheme Procedure} inferior-package? @var{obj}
4049 Return true if @var{obj} is an inferior package.
4052 @deffn {Scheme Procedure} inferior-package-name @var{package}
4053 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4054 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4055 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4056 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4057 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4058 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4059 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4060 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4061 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4062 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4063 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4064 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4065 These procedures are the counterpart of package record accessors
4066 (@pxref{package Reference}). Most of them work by querying the inferior
4067 @var{package} comes from, so the inferior must still be live when you call
4071 Inferior packages can be used transparently like any other package or
4072 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4073 transparently handled by the @code{packages->manifest} procedure, which is
4074 commonly use in manifests (@pxref{Invoking guix package, the
4075 @option{--manifest} option of @command{guix package}}). Thus you can insert
4076 an inferior package pretty much anywhere you would insert a regular package:
4077 in manifests, in the @code{packages} field of your @code{operating-system}
4078 declaration, and so on.
4080 @node Invoking guix describe
4081 @section Invoking @command{guix describe}
4083 @cindex reproducibility
4084 @cindex replicating Guix
4085 Often you may want to answer questions like: ``Which revision of Guix am I
4086 using?'' or ``Which channels am I using?'' This is useful information in many
4087 situations: if you want to @emph{replicate} an environment on a different
4088 machine or user account, if you want to report a bug or to determine what
4089 change in the channels you are using caused it, or if you want to record your
4090 system state for reproducibility purposes. The @command{guix describe}
4091 command answers these questions.
4093 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4094 displays the channel(s) that it was built from, including their repository URL
4095 and commit IDs (@pxref{Channels}):
4099 Generation 10 Sep 03 2018 17:32:44 (current)
4101 repository URL: https://git.savannah.gnu.org/git/guix.git
4103 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4106 If you're familiar with the Git version control system, this is similar in
4107 spirit to @command{git describe}; the output is also similar to that of
4108 @command{guix pull --list-generations}, but limited to the current generation
4109 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4110 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4111 information is all it takes to describe the revision of Guix you're using, and
4112 also to replicate it.
4114 To make it easier to replicate Guix, @command{guix describe} can also be asked
4115 to return a list of channels instead of the human-readable description above:
4118 $ guix describe -f channels
4121 (url "https://git.savannah.gnu.org/git/guix.git")
4123 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4127 You can save this to a file and feed it to @command{guix pull -C} on some
4128 other machine or at a later point in time, which will instantiate @emph{this
4129 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4130 From there on, since you're able to deploy the same revision of Guix, you can
4131 just as well @emph{replicate a complete software environment}. We humbly
4132 think that this is @emph{awesome}, and we hope you'll like it too!
4134 The details of the options supported by @command{guix describe} are as
4138 @item --format=@var{format}
4139 @itemx -f @var{format}
4140 Produce output in the specified @var{format}, one of:
4144 produce human-readable output;
4146 produce a list of channel specifications that can be passed to @command{guix
4147 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4151 produce a list of channel specifications in JSON format;
4153 produce a list of channel specifications in Recutils format.
4156 @item --profile=@var{profile}
4157 @itemx -p @var{profile}
4158 Display information about @var{profile}.
4161 @node Invoking guix archive
4162 @section Invoking @command{guix archive}
4164 @cindex @command{guix archive}
4166 The @command{guix archive} command allows users to @dfn{export} files
4167 from the store into a single archive, and to later @dfn{import} them on
4168 a machine that runs Guix.
4169 In particular, it allows store files to be transferred from one machine
4170 to the store on another machine.
4173 If you're looking for a way to produce archives in a format suitable for
4174 tools other than Guix, @pxref{Invoking guix pack}.
4177 @cindex exporting store items
4178 To export store files as an archive to standard output, run:
4181 guix archive --export @var{options} @var{specifications}...
4184 @var{specifications} may be either store file names or package
4185 specifications, as for @command{guix package} (@pxref{Invoking guix
4186 package}). For instance, the following command creates an archive
4187 containing the @code{gui} output of the @code{git} package and the main
4188 output of @code{emacs}:
4191 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4194 If the specified packages are not built yet, @command{guix archive}
4195 automatically builds them. The build process may be controlled with the
4196 common build options (@pxref{Common Build Options}).
4198 To transfer the @code{emacs} package to a machine connected over SSH,
4202 guix archive --export -r emacs | ssh the-machine guix archive --import
4206 Similarly, a complete user profile may be transferred from one machine
4207 to another like this:
4210 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4211 ssh the-machine guix-archive --import
4215 However, note that, in both examples, all of @code{emacs} and the
4216 profile as well as all of their dependencies are transferred (due to
4217 @code{-r}), regardless of what is already available in the store on the
4218 target machine. The @code{--missing} option can help figure out which
4219 items are missing from the target store. The @command{guix copy}
4220 command simplifies and optimizes this whole process, so this is probably
4221 what you should use in this case (@pxref{Invoking guix copy}).
4223 @cindex nar, archive format
4224 @cindex normalized archive (nar)
4225 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4226 comparable in spirit to `tar', but with differences
4227 that make it more appropriate for our purposes. First, rather than
4228 recording all Unix metadata for each file, the nar format only mentions
4229 the file type (regular, directory, or symbolic link); Unix permissions
4230 and owner/group are dismissed. Second, the order in which directory
4231 entries are stored always follows the order of file names according to
4232 the C locale collation order. This makes archive production fully
4235 When exporting, the daemon digitally signs the contents of the archive,
4236 and that digital signature is appended. When importing, the daemon
4237 verifies the signature and rejects the import in case of an invalid
4238 signature or if the signing key is not authorized.
4239 @c FIXME: Add xref to daemon doc about signatures.
4241 The main options are:
4245 Export the specified store files or packages (see below.) Write the
4246 resulting archive to the standard output.
4248 Dependencies are @emph{not} included in the output, unless
4249 @code{--recursive} is passed.
4253 When combined with @code{--export}, this instructs @command{guix
4254 archive} to include dependencies of the given items in the archive.
4255 Thus, the resulting archive is self-contained: it contains the closure
4256 of the exported store items.
4259 Read an archive from the standard input, and import the files listed
4260 therein into the store. Abort if the archive has an invalid digital
4261 signature, or if it is signed by a public key not among the authorized
4262 keys (see @code{--authorize} below.)
4265 Read a list of store file names from the standard input, one per line,
4266 and write on the standard output the subset of these files missing from
4269 @item --generate-key[=@var{parameters}]
4270 @cindex signing, archives
4271 Generate a new key pair for the daemon. This is a prerequisite before
4272 archives can be exported with @code{--export}. Note that this operation
4273 usually takes time, because it needs to gather enough entropy to
4274 generate the key pair.
4276 The generated key pair is typically stored under @file{/etc/guix}, in
4277 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4278 key, which must be kept secret.) When @var{parameters} is omitted,
4279 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4280 versions before 1.6.0, it is a 4096-bit RSA key.
4281 Alternatively, @var{parameters} can specify
4282 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4283 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4284 Libgcrypt Reference Manual}).
4287 @cindex authorizing, archives
4288 Authorize imports signed by the public key passed on standard input.
4289 The public key must be in ``s-expression advanced format''---i.e., the
4290 same format as the @file{signing-key.pub} file.
4292 The list of authorized keys is kept in the human-editable file
4293 @file{/etc/guix/acl}. The file contains
4294 @url{http://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4295 s-expressions''} and is structured as an access-control list in the
4296 @url{http://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4299 @item --extract=@var{directory}
4300 @itemx -x @var{directory}
4301 Read a single-item archive as served by substitute servers
4302 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4303 low-level operation needed in only very narrow use cases; see below.
4305 For example, the following command extracts the substitute for Emacs
4306 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4310 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
4311 | bunzip2 | guix archive -x /tmp/emacs
4314 Single-item archives are different from multiple-item archives produced
4315 by @command{guix archive --export}; they contain a single store item,
4316 and they do @emph{not} embed a signature. Thus this operation does
4317 @emph{no} signature verification and its output should be considered
4320 The primary purpose of this operation is to facilitate inspection of
4321 archive contents coming from possibly untrusted substitute servers.
4326 @c *********************************************************************
4328 @chapter Development
4330 @cindex software development
4331 If you are a software developer, Guix provides tools that you should find
4332 helpful---independently of the language you're developing in. This is what
4333 this chapter is about.
4335 The @command{guix environment} command provides a convenient way to set up
4336 @dfn{development environments} containing all the dependencies and tools
4337 necessary to work on the software package of your choice. The @command{guix
4338 pack} command allows you to create @dfn{application bundles} that can be
4339 easily distributed to users who do not run Guix.
4342 * Invoking guix environment:: Setting up development environments.
4343 * Invoking guix pack:: Creating software bundles.
4346 @node Invoking guix environment
4347 @section Invoking @command{guix environment}
4349 @cindex reproducible build environments
4350 @cindex development environments
4351 @cindex @command{guix environment}
4352 @cindex environment, package build environment
4353 The purpose of @command{guix environment} is to assist hackers in
4354 creating reproducible development environments without polluting their
4355 package profile. The @command{guix environment} tool takes one or more
4356 packages, builds all of their inputs, and creates a shell
4357 environment to use them.
4359 The general syntax is:
4362 guix environment @var{options} @var{package}@dots{}
4365 The following example spawns a new shell set up for the development of
4369 guix environment guile
4372 If the needed dependencies are not built yet, @command{guix environment}
4373 automatically builds them. The environment of the new shell is an augmented
4374 version of the environment that @command{guix environment} was run in.
4375 It contains the necessary search paths for building the given package
4376 added to the existing environment variables. To create a ``pure''
4377 environment, in which the original environment variables have been unset,
4378 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
4379 environment variables such as @code{PATH} in their @file{~/.bashrc}
4380 file. As a consequence, when @code{guix environment} launches it, Bash
4381 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
4382 environment variables. It is an error to define such environment
4383 variables in @file{.bashrc}; instead, they should be defined in
4384 @file{.bash_profile}, which is sourced only by log-in shells.
4385 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
4386 details on Bash start-up files.}.
4388 @vindex GUIX_ENVIRONMENT
4389 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
4390 variable in the shell it spawns; its value is the file name of the
4391 profile of this environment. This allows users to, say, define a
4392 specific prompt for development environments in their @file{.bashrc}
4393 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4396 if [ -n "$GUIX_ENVIRONMENT" ]
4398 export PS1="\u@@\h \w [dev]\$ "
4403 ...@: or to browse the profile:
4406 $ ls "$GUIX_ENVIRONMENT/bin"
4409 Additionally, more than one package may be specified, in which case the
4410 union of the inputs for the given packages are used. For example, the
4411 command below spawns a shell where all of the dependencies of both Guile
4412 and Emacs are available:
4415 guix environment guile emacs
4418 Sometimes an interactive shell session is not desired. An arbitrary
4419 command may be invoked by placing the @code{--} token to separate the
4420 command from the rest of the arguments:
4423 guix environment guile -- make -j4
4426 In other situations, it is more convenient to specify the list of
4427 packages needed in the environment. For example, the following command
4428 runs @command{python} from an environment containing Python@tie{}2.7 and
4432 guix environment --ad-hoc python2-numpy python-2.7 -- python
4435 Furthermore, one might want the dependencies of a package and also some
4436 additional packages that are not build-time or runtime dependencies, but
4437 are useful when developing nonetheless. Because of this, the
4438 @code{--ad-hoc} flag is positional. Packages appearing before
4439 @code{--ad-hoc} are interpreted as packages whose dependencies will be
4440 added to the environment. Packages appearing after are interpreted as
4441 packages that will be added to the environment directly. For example,
4442 the following command creates a Guix development environment that
4443 additionally includes Git and strace:
4446 guix environment guix --ad-hoc git strace
4449 Sometimes it is desirable to isolate the environment as much as
4450 possible, for maximal purity and reproducibility. In particular, when
4451 using Guix on a host distro that is not Guix System, it is desirable to
4452 prevent access to @file{/usr/bin} and other system-wide resources from
4453 the development environment. For example, the following command spawns
4454 a Guile REPL in a ``container'' where only the store and the current
4455 working directory are mounted:
4458 guix environment --ad-hoc --container guile -- guile
4462 The @code{--container} option requires Linux-libre 3.19 or newer.
4465 The available options are summarized below.
4468 @item --root=@var{file}
4469 @itemx -r @var{file}
4470 @cindex persistent environment
4471 @cindex garbage collector root, for environments
4472 Make @var{file} a symlink to the profile for this environment, and
4473 register it as a garbage collector root.
4475 This is useful if you want to protect your environment from garbage
4476 collection, to make it ``persistent''.
4478 When this option is omitted, the environment is protected from garbage
4479 collection only for the duration of the @command{guix environment}
4480 session. This means that next time you recreate the same environment,
4481 you could have to rebuild or re-download packages. @xref{Invoking guix
4482 gc}, for more on GC roots.
4484 @item --expression=@var{expr}
4485 @itemx -e @var{expr}
4486 Create an environment for the package or list of packages that
4487 @var{expr} evaluates to.
4489 For example, running:
4492 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4495 starts a shell with the environment for this specific variant of the
4501 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4504 starts a shell with all the base system packages available.
4506 The above commands only use the default output of the given packages.
4507 To select other outputs, two element tuples can be specified:
4510 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4513 @item --load=@var{file}
4514 @itemx -l @var{file}
4515 Create an environment for the package or list of packages that the code
4516 within @var{file} evaluates to.
4518 As an example, @var{file} might contain a definition like this
4519 (@pxref{Defining Packages}):
4522 @verbatiminclude environment-gdb.scm
4525 @item --manifest=@var{file}
4526 @itemx -m @var{file}
4527 Create an environment for the packages contained in the manifest object
4528 returned by the Scheme code in @var{file}.
4530 This is similar to the same-named option in @command{guix package}
4531 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4535 Include all specified packages in the resulting environment, as if an
4536 @i{ad hoc} package were defined with them as inputs. This option is
4537 useful for quickly creating an environment without having to write a
4538 package expression to contain the desired inputs.
4540 For instance, the command:
4543 guix environment --ad-hoc guile guile-sdl -- guile
4546 runs @command{guile} in an environment where Guile and Guile-SDL are
4549 Note that this example implicitly asks for the default output of
4550 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4551 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4552 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4554 This option may be composed with the default behavior of @command{guix
4555 environment}. Packages appearing before @code{--ad-hoc} are interpreted
4556 as packages whose dependencies will be added to the environment, the
4557 default behavior. Packages appearing after are interpreted as packages
4558 that will be added to the environment directly.
4561 Unset existing environment variables when building the new environment, except
4562 those specified with @option{--preserve} (see below.) This has the effect of
4563 creating an environment in which search paths only contain package inputs.
4565 @item --preserve=@var{regexp}
4566 @itemx -E @var{regexp}
4567 When used alongside @option{--pure}, preserve the environment variables
4568 matching @var{regexp}---in other words, put them on a ``white list'' of
4569 environment variables that must be preserved. This option can be repeated
4573 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4577 This example runs @command{mpirun} in a context where the only environment
4578 variables defined are @code{PATH}, environment variables whose name starts
4579 with @code{SLURM}, as well as the usual ``precious'' variables (@code{HOME},
4582 @item --search-paths
4583 Display the environment variable definitions that make up the
4586 @item --system=@var{system}
4587 @itemx -s @var{system}
4588 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4593 Run @var{command} within an isolated container. The current working
4594 directory outside the container is mapped inside the container.
4595 Additionally, unless overridden with @code{--user}, a dummy home
4596 directory is created that matches the current user's home directory, and
4597 @file{/etc/passwd} is configured accordingly.
4599 The spawned process runs as the current user outside the container. Inside
4600 the container, it has the same UID and GID as the current user, unless
4601 @option{--user} is passed (see below.)
4605 For containers, share the network namespace with the host system.
4606 Containers created without this flag only have access to the loopback
4609 @item --link-profile
4611 For containers, link the environment profile to
4612 @file{~/.guix-profile} within the container. This is equivalent to
4613 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
4614 within the container. Linking will fail and abort the environment if
4615 the directory already exists, which will certainly be the case if
4616 @command{guix environment} was invoked in the user's home directory.
4618 Certain packages are configured to look in
4619 @code{~/.guix-profile} for configuration files and data;@footnote{For
4620 example, the @code{fontconfig} package inspects
4621 @file{~/.guix-profile/share/fonts} for additional fonts.}
4622 @code{--link-profile} allows these programs to behave as expected within
4625 @item --user=@var{user}
4626 @itemx -u @var{user}
4627 For containers, use the username @var{user} in place of the current
4628 user. The generated @file{/etc/passwd} entry within the container will
4629 contain the name @var{user}, the home directory will be
4630 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4631 the UID and GID inside the container are 1000. @var{user}
4632 need not exist on the system.
4634 Additionally, any shared or exposed path (see @code{--share} and
4635 @code{--expose} respectively) whose target is within the current user's
4636 home directory will be remapped relative to @file{/home/USER}; this
4637 includes the automatic mapping of the current working directory.
4640 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4642 guix environment --container --user=foo \
4643 --expose=$HOME/test \
4644 --expose=/tmp/target=$HOME/target
4647 While this will limit the leaking of user identity through home paths
4648 and each of the user fields, this is only one useful component of a
4649 broader privacy/anonymity solution---not one in and of itself.
4651 @item --expose=@var{source}[=@var{target}]
4652 For containers, expose the file system @var{source} from the host system
4653 as the read-only file system @var{target} within the container. If
4654 @var{target} is not specified, @var{source} is used as the target mount
4655 point in the container.
4657 The example below spawns a Guile REPL in a container in which the user's
4658 home directory is accessible read-only via the @file{/exchange}
4662 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
4665 @item --share=@var{source}[=@var{target}]
4666 For containers, share the file system @var{source} from the host system
4667 as the writable file system @var{target} within the container. If
4668 @var{target} is not specified, @var{source} is used as the target mount
4669 point in the container.
4671 The example below spawns a Guile REPL in a container in which the user's
4672 home directory is accessible for both reading and writing via the
4673 @file{/exchange} directory:
4676 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
4680 @command{guix environment}
4681 also supports all of the common build options that @command{guix
4682 build} supports (@pxref{Common Build Options}) as well as package
4683 transformation options (@pxref{Package Transformation Options}).
4685 @node Invoking guix pack
4686 @section Invoking @command{guix pack}
4688 Occasionally you want to pass software to people who are not (yet!)
4689 lucky enough to be using Guix. You'd tell them to run @command{guix
4690 package -i @var{something}}, but that's not possible in this case. This
4691 is where @command{guix pack} comes in.
4694 If you are looking for ways to exchange binaries among machines that
4695 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
4696 publish}, and @ref{Invoking guix archive}.
4701 @cindex application bundle
4702 @cindex software bundle
4703 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
4704 @dfn{software bundle}: it creates a tarball or some other archive
4705 containing the binaries of the software you're interested in, and all
4706 its dependencies. The resulting archive can be used on any machine that
4707 does not have Guix, and people can run the exact same binaries as those
4708 you have with Guix. The pack itself is created in a bit-reproducible
4709 fashion, so anyone can verify that it really contains the build results
4710 that you pretend to be shipping.
4712 For example, to create a bundle containing Guile, Emacs, Geiser, and all
4713 their dependencies, you can run:
4716 $ guix pack guile emacs geiser
4718 /gnu/store/@dots{}-pack.tar.gz
4721 The result here is a tarball containing a @file{/gnu/store} directory
4722 with all the relevant packages. The resulting tarball contains a
4723 @dfn{profile} with the three packages of interest; the profile is the
4724 same as would be created by @command{guix package -i}. It is this
4725 mechanism that is used to create Guix's own standalone binary tarball
4726 (@pxref{Binary Installation}).
4728 Users of this pack would have to run
4729 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
4730 find inconvenient. To work around it, you can create, say, a
4731 @file{/opt/gnu/bin} symlink to the profile:
4734 guix pack -S /opt/gnu/bin=bin guile emacs geiser
4738 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
4740 @cindex relocatable binaries, with @command{guix pack}
4741 What if the recipient of your pack does not have root privileges on
4742 their machine, and thus cannot unpack it in the root file system? In
4743 that case, you will want to use the @code{--relocatable} option (see
4744 below). This option produces @dfn{relocatable binaries}, meaning they
4745 they can be placed anywhere in the file system hierarchy: in the example
4746 above, users can unpack your tarball in their home directory and
4747 directly run @file{./opt/gnu/bin/guile}.
4749 @cindex Docker, build an image with guix pack
4750 Alternatively, you can produce a pack in the Docker image format using
4751 the following command:
4754 guix pack -f docker guile emacs geiser
4758 The result is a tarball that can be passed to the @command{docker load}
4760 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
4761 documentation} for more information.
4763 @cindex Singularity, build an image with guix pack
4764 @cindex SquashFS, build an image with guix pack
4765 Yet another option is to produce a SquashFS image with the following
4769 guix pack -f squashfs guile emacs geiser
4773 The result is a SquashFS file system image that can either be mounted or
4774 directly be used as a file system container image with the
4775 @uref{http://singularity.lbl.gov, Singularity container execution
4776 environment}, using commands like @command{singularity shell} or
4777 @command{singularity exec}.
4779 Several command-line options allow you to customize your pack:
4782 @item --format=@var{format}
4783 @itemx -f @var{format}
4784 Produce a pack in the given @var{format}.
4786 The available formats are:
4790 This is the default format. It produces a tarball containing all the
4791 specified binaries and symlinks.
4794 This produces a tarball that follows the
4795 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
4796 Docker Image Specification}.
4799 This produces a SquashFS image containing all the specified binaries and
4800 symlinks, as well as empty mount points for virtual file systems like
4804 @cindex relocatable binaries
4807 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
4808 anywhere in the file system hierarchy and run from there.
4810 When this option is passed once, the resulting binaries require support for
4811 @dfn{user namespaces} in the kernel Linux; when passed
4812 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
4813 PRoot support, can be thought of as the abbreviation of ``Really
4814 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
4815 if user namespaces are unavailable, and essentially work anywhere---see below
4816 for the implications.
4818 For example, if you create a pack containing Bash with:
4821 guix pack -RR -S /mybin=bin bash
4825 ...@: you can copy that pack to a machine that lacks Guix, and from your
4826 home directory as a normal user, run:
4834 In that shell, if you type @code{ls /gnu/store}, you'll notice that
4835 @file{/gnu/store} shows up and contains all the dependencies of
4836 @code{bash}, even though the machine actually lacks @file{/gnu/store}
4837 altogether! That is probably the simplest way to deploy Guix-built
4838 software on a non-Guix machine.
4841 By default, relocatable binaries rely on the @dfn{user namespace} feature of
4842 the kernel Linux, which allows unprivileged users to mount or change root.
4843 Old versions of Linux did not support it, and some GNU/Linux distributions
4846 To produce relocatable binaries that work even in the absence of user
4847 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
4848 case, binaries will try user namespace support and fall back to PRoot if user
4849 namespaces are not supported.
4851 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
4852 support for file system virtualization. It achieves that by using the
4853 @code{ptrace} system call on the running program. This approach has the
4854 advantage to work without requiring special kernel support, but it incurs
4855 run-time overhead every time a system call is made.
4858 @item --expression=@var{expr}
4859 @itemx -e @var{expr}
4860 Consider the package @var{expr} evaluates to.
4862 This has the same purpose as the same-named option in @command{guix
4863 build} (@pxref{Additional Build Options, @code{--expression} in
4864 @command{guix build}}).
4866 @item --manifest=@var{file}
4867 @itemx -m @var{file}
4868 Use the packages contained in the manifest object returned by the Scheme
4871 This has a similar purpose as the same-named option in @command{guix
4872 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
4873 same manifest files. It allows you to define a collection of packages
4874 once and use it both for creating profiles and for creating archives
4875 for use on machines that do not have Guix installed. Note that you can
4876 specify @emph{either} a manifest file @emph{or} a list of packages,
4879 @item --system=@var{system}
4880 @itemx -s @var{system}
4881 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4882 the system type of the build host.
4884 @item --target=@var{triplet}
4885 @cindex cross-compilation
4886 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
4887 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
4888 configuration triplets,, autoconf, Autoconf}).
4890 @item --compression=@var{tool}
4891 @itemx -C @var{tool}
4892 Compress the resulting tarball using @var{tool}---one of @code{gzip},
4893 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
4895 @item --symlink=@var{spec}
4896 @itemx -S @var{spec}
4897 Add the symlinks specified by @var{spec} to the pack. This option can
4898 appear several times.
4900 @var{spec} has the form @code{@var{source}=@var{target}}, where
4901 @var{source} is the symlink that will be created and @var{target} is the
4904 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
4905 symlink pointing to the @file{bin} sub-directory of the profile.
4907 @item --save-provenance
4908 Save provenance information for the packages passed on the command line.
4909 Provenance information includes the URL and commit of the channels in use
4912 Provenance information is saved in the
4913 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
4914 usual package metadata---the name and version of each package, their
4915 propagated inputs, and so on. It is useful information to the recipient of
4916 the pack, who then knows how the pack was (supposedly) obtained.
4918 This option is not enabled by default because, like timestamps, provenance
4919 information contributes nothing to the build process. In other words, there
4920 is an infinity of channel URLs and commit IDs that can lead to the same pack.
4921 Recording such ``silent'' metadata in the output thus potentially breaks the
4922 source-to-binary bitwise reproducibility property.
4924 @item --localstatedir
4925 @itemx --profile-name=@var{name}
4926 Include the ``local state directory'', @file{/var/guix}, in the resulting
4927 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
4928 profile---by default @var{name} is @code{guix-profile}, which corresponds to
4929 @file{~root/.guix-profile}.
4931 @file{/var/guix} contains the store database (@pxref{The Store}) as well
4932 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
4933 the pack means that the store is ``complete'' and manageable by Guix;
4934 not providing it pack means that the store is ``dead'': items cannot be
4935 added to it or removed from it after extraction of the pack.
4937 One use case for this is the Guix self-contained binary tarball
4938 (@pxref{Binary Installation}).
4941 Use the bootstrap binaries to build the pack. This option is only
4942 useful to Guix developers.
4945 In addition, @command{guix pack} supports all the common build options
4946 (@pxref{Common Build Options}) and all the package transformation
4947 options (@pxref{Package Transformation Options}).
4950 @c *********************************************************************
4951 @node Programming Interface
4952 @chapter Programming Interface
4954 GNU Guix provides several Scheme programming interfaces (APIs) to
4955 define, build, and query packages. The first interface allows users to
4956 write high-level package definitions. These definitions refer to
4957 familiar packaging concepts, such as the name and version of a package,
4958 its build system, and its dependencies. These definitions can then be
4959 turned into concrete build actions.
4961 Build actions are performed by the Guix daemon, on behalf of users. In a
4962 standard setup, the daemon has write access to the store---the
4963 @file{/gnu/store} directory---whereas users do not. The recommended
4964 setup also has the daemon perform builds in chroots, under a specific
4965 build users, to minimize interference with the rest of the system.
4968 Lower-level APIs are available to interact with the daemon and the
4969 store. To instruct the daemon to perform a build action, users actually
4970 provide it with a @dfn{derivation}. A derivation is a low-level
4971 representation of the build actions to be taken, and the environment in
4972 which they should occur---derivations are to package definitions what
4973 assembly is to C programs. The term ``derivation'' comes from the fact
4974 that build results @emph{derive} from them.
4976 This chapter describes all these APIs in turn, starting from high-level
4977 package definitions.
4980 * Package Modules:: Packages from the programmer's viewpoint.
4981 * Defining Packages:: Defining new packages.
4982 * Build Systems:: Specifying how packages are built.
4983 * The Store:: Manipulating the package store.
4984 * Derivations:: Low-level interface to package derivations.
4985 * The Store Monad:: Purely functional interface to the store.
4986 * G-Expressions:: Manipulating build expressions.
4987 * Invoking guix repl:: Fiddling with Guix interactively.
4990 @node Package Modules
4991 @section Package Modules
4993 From a programming viewpoint, the package definitions of the
4994 GNU distribution are provided by Guile modules in the @code{(gnu packages
4995 @dots{})} name space@footnote{Note that packages under the @code{(gnu
4996 packages @dots{})} module name space are not necessarily ``GNU
4997 packages''. This module naming scheme follows the usual Guile module
4998 naming convention: @code{gnu} means that these modules are distributed
4999 as part of the GNU system, and @code{packages} identifies modules that
5000 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5001 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5002 module exports a variable named @code{emacs}, which is bound to a
5003 @code{<package>} object (@pxref{Defining Packages}).
5005 The @code{(gnu packages @dots{})} module name space is
5006 automatically scanned for packages by the command-line tools. For
5007 instance, when running @code{guix install emacs}, all the @code{(gnu
5008 packages @dots{})} modules are scanned until one that exports a package
5009 object whose name is @code{emacs} is found. This package search
5010 facility is implemented in the @code{(gnu packages)} module.
5012 @cindex customization, of packages
5013 @cindex package module search path
5014 Users can store package definitions in modules with different
5015 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5016 name and module name must match. For instance, the @code{(my-packages
5017 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5018 relative to the load path specified with @option{--load-path} or
5019 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5020 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5021 these package definitions visible to the user interfaces:
5025 By adding the directory containing your package modules to the search path
5026 with the @code{-L} flag of @command{guix package} and other commands
5027 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
5028 environment variable described below.
5031 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5032 pulls from it. A channel is essentially a Git repository containing package
5033 modules. @xref{Channels}, for more information on how to define and use
5037 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5039 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5040 This is a colon-separated list of directories to search for additional
5041 package modules. Directories listed in this variable take precedence
5042 over the own modules of the distribution.
5045 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5046 each package is built based solely on other packages in the
5047 distribution. The root of this dependency graph is a small set of
5048 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5049 bootstrap)} module. For more information on bootstrapping,
5050 @pxref{Bootstrapping}.
5052 @node Defining Packages
5053 @section Defining Packages
5055 The high-level interface to package definitions is implemented in the
5056 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5057 example, the package definition, or @dfn{recipe}, for the GNU Hello
5058 package looks like this:
5061 (define-module (gnu packages hello)
5062 #:use-module (guix packages)
5063 #:use-module (guix download)
5064 #:use-module (guix build-system gnu)
5065 #:use-module (guix licenses)
5066 #:use-module (gnu packages gawk))
5068 (define-public hello
5074 (uri (string-append "mirror://gnu/hello/hello-" version
5078 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5079 (build-system gnu-build-system)
5080 (arguments '(#:configure-flags '("--enable-silent-rules")))
5081 (inputs `(("gawk" ,gawk)))
5082 (synopsis "Hello, GNU world: An example GNU package")
5083 (description "Guess what GNU Hello prints!")
5084 (home-page "http://www.gnu.org/software/hello/")
5089 Without being a Scheme expert, the reader may have guessed the meaning
5090 of the various fields here. This expression binds the variable
5091 @code{hello} to a @code{<package>} object, which is essentially a record
5092 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5093 This package object can be inspected using procedures found in the
5094 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5095 returns---surprise!---@code{"hello"}.
5097 With luck, you may be able to import part or all of the definition of
5098 the package you are interested in from another repository, using the
5099 @code{guix import} command (@pxref{Invoking guix import}).
5101 In the example above, @var{hello} is defined in a module of its own,
5102 @code{(gnu packages hello)}. Technically, this is not strictly
5103 necessary, but it is convenient to do so: all the packages defined in
5104 modules under @code{(gnu packages @dots{})} are automatically known to
5105 the command-line tools (@pxref{Package Modules}).
5107 There are a few points worth noting in the above package definition:
5111 The @code{source} field of the package is an @code{<origin>} object
5112 (@pxref{origin Reference}, for the complete reference).
5113 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5114 meaning that the source is a file to be downloaded over FTP or HTTP.
5116 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5117 the GNU mirrors defined in @code{(guix download)}.
5119 The @code{sha256} field specifies the expected SHA256 hash of the file
5120 being downloaded. It is mandatory, and allows Guix to check the
5121 integrity of the file. The @code{(base32 @dots{})} form introduces the
5122 base32 representation of the hash. You can obtain this information with
5123 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5124 hash} (@pxref{Invoking guix hash}).
5127 When needed, the @code{origin} form can also have a @code{patches} field
5128 listing patches to be applied, and a @code{snippet} field giving a
5129 Scheme expression to modify the source code.
5132 @cindex GNU Build System
5133 The @code{build-system} field specifies the procedure to build the
5134 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5135 represents the familiar GNU Build System, where packages may be
5136 configured, built, and installed with the usual @code{./configure &&
5137 make && make check && make install} command sequence.
5140 The @code{arguments} field specifies options for the build system
5141 (@pxref{Build Systems}). Here it is interpreted by
5142 @var{gnu-build-system} as a request run @file{configure} with the
5143 @code{--enable-silent-rules} flag.
5149 What about these quote (@code{'}) characters? They are Scheme syntax to
5150 introduce a literal list; @code{'} is synonymous with @code{quote}.
5151 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5152 for details. Here the value of the @code{arguments} field is a list of
5153 arguments passed to the build system down the road, as with @code{apply}
5154 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5157 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5158 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5159 @code{#:configure-flags} is a keyword used to pass a keyword argument
5160 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5164 The @code{inputs} field specifies inputs to the build process---i.e.,
5165 build-time or run-time dependencies of the package. Here, we define an
5166 input called @code{"gawk"} whose value is that of the @var{gawk}
5167 variable; @var{gawk} is itself bound to a @code{<package>} object.
5169 @cindex backquote (quasiquote)
5172 @cindex comma (unquote)
5176 @findex unquote-splicing
5177 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5178 us to introduce a literal list in the @code{inputs} field, while
5179 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5180 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5183 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5184 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5185 of ensuring that they are present (@pxref{Build Systems}).
5187 However, any other dependencies need to be specified in the
5188 @code{inputs} field. Any dependency not specified here will simply be
5189 unavailable to the build process, possibly leading to a build failure.
5192 @xref{package Reference}, for a full description of possible fields.
5194 Once a package definition is in place, the
5195 package may actually be built using the @code{guix build} command-line
5196 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5197 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5198 package definition using the @command{guix edit} command
5199 (@pxref{Invoking guix edit}).
5200 @xref{Packaging Guidelines}, for
5201 more information on how to test package definitions, and
5202 @ref{Invoking guix lint}, for information on how to check a definition
5203 for style conformance.
5204 @vindex GUIX_PACKAGE_PATH
5205 Lastly, @pxref{Channels}, for information
5206 on how to extend the distribution by adding your own package definitions
5209 Finally, updating the package definition to a new upstream version
5210 can be partly automated by the @command{guix refresh} command
5211 (@pxref{Invoking guix refresh}).
5213 Behind the scenes, a derivation corresponding to the @code{<package>}
5214 object is first computed by the @code{package-derivation} procedure.
5215 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
5216 The build actions it prescribes may then be realized by using the
5217 @code{build-derivations} procedure (@pxref{The Store}).
5219 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5220 Return the @code{<derivation>} object of @var{package} for @var{system}
5221 (@pxref{Derivations}).
5223 @var{package} must be a valid @code{<package>} object, and @var{system}
5224 must be a string denoting the target system type---e.g.,
5225 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5226 must be a connection to the daemon, which operates on the store
5227 (@pxref{The Store}).
5231 @cindex cross-compilation
5232 Similarly, it is possible to compute a derivation that cross-builds a
5233 package for some other system:
5235 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5236 @var{package} @var{target} [@var{system}]
5237 Return the @code{<derivation>} object of @var{package} cross-built from
5238 @var{system} to @var{target}.
5240 @var{target} must be a valid GNU triplet denoting the target hardware
5241 and operating system, such as @code{"mips64el-linux-gnu"}
5242 (@pxref{Configuration Names, GNU configuration triplets,, configure, GNU
5243 Configure and Build System}).
5246 @cindex package transformations
5247 @cindex input rewriting
5248 @cindex dependency tree rewriting
5249 Packages can be manipulated in arbitrary ways. An example of a useful
5250 transformation is @dfn{input rewriting}, whereby the dependency tree of
5251 a package is rewritten by replacing specific inputs by others:
5253 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5254 [@var{rewrite-name}]
5255 Return a procedure that, when passed a package, replaces its direct and
5256 indirect dependencies (but not its implicit inputs) according to
5257 @var{replacements}. @var{replacements} is a list of package pairs; the
5258 first element of each pair is the package to replace, and the second one
5261 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5262 the name of a package and returns its new name after rewrite.
5266 Consider this example:
5269 (define libressl-instead-of-openssl
5270 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5272 (package-input-rewriting `((,openssl . ,libressl))))
5274 (define git-with-libressl
5275 (libressl-instead-of-openssl git))
5279 Here we first define a rewriting procedure that replaces @var{openssl}
5280 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5281 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5282 This is exactly what the @option{--with-input} command-line option does
5283 (@pxref{Package Transformation Options, @option{--with-input}}).
5285 The following variant of @code{package-input-rewriting} can match packages to
5286 be replaced by name rather than by identity.
5288 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5289 Return a procedure that, given a package, applies the given @var{replacements} to
5290 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5291 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5292 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5293 replacement for that package.
5296 The example above could be rewritten this way:
5299 (define libressl-instead-of-openssl
5300 ;; Replace all the packages called "openssl" with LibreSSL.
5301 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5304 The key difference here is that, this time, packages are matched by spec and
5305 not by identity. In other words, any package in the graph that is called
5306 @code{openssl} will be replaced.
5308 A more generic procedure to rewrite a package dependency graph is
5309 @code{package-mapping}: it supports arbitrary changes to nodes in the
5312 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5313 Return a procedure that, given a package, applies @var{proc} to all the packages
5314 depended on and returns the resulting package. The procedure stops recursion
5315 when @var{cut?} returns true for a given package.
5319 * package Reference:: The package data type.
5320 * origin Reference:: The origin data type.
5324 @node package Reference
5325 @subsection @code{package} Reference
5327 This section summarizes all the options available in @code{package}
5328 declarations (@pxref{Defining Packages}).
5330 @deftp {Data Type} package
5331 This is the data type representing a package recipe.
5335 The name of the package, as a string.
5337 @item @code{version}
5338 The version of the package, as a string.
5341 An object telling how the source code for the package should be
5342 acquired. Most of the time, this is an @code{origin} object, which
5343 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5344 can also be any other ``file-like'' object such as a @code{local-file},
5345 which denotes a file from the local file system (@pxref{G-Expressions,
5346 @code{local-file}}).
5348 @item @code{build-system}
5349 The build system that should be used to build the package (@pxref{Build
5352 @item @code{arguments} (default: @code{'()})
5353 The arguments that should be passed to the build system. This is a
5354 list, typically containing sequential keyword-value pairs.
5356 @item @code{inputs} (default: @code{'()})
5357 @itemx @code{native-inputs} (default: @code{'()})
5358 @itemx @code{propagated-inputs} (default: @code{'()})
5359 @cindex inputs, of packages
5360 These fields list dependencies of the package. Each one is a list of
5361 tuples, where each tuple has a label for the input (a string) as its
5362 first element, a package, origin, or derivation as its second element,
5363 and optionally the name of the output thereof that should be used, which
5364 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5365 more on package outputs). For example, the list below specifies three
5369 `(("libffi" ,libffi)
5370 ("libunistring" ,libunistring)
5371 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5374 @cindex cross compilation, package dependencies
5375 The distinction between @code{native-inputs} and @code{inputs} is
5376 necessary when considering cross-compilation. When cross-compiling,
5377 dependencies listed in @code{inputs} are built for the @emph{target}
5378 architecture; conversely, dependencies listed in @code{native-inputs}
5379 are built for the architecture of the @emph{build} machine.
5381 @code{native-inputs} is typically used to list tools needed at
5382 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5383 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5384 this area (@pxref{Invoking guix lint}).
5386 @anchor{package-propagated-inputs}
5387 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5388 specified packages will be automatically installed alongside the package
5389 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5390 package}}, for information on how @command{guix package} deals with
5393 For example this is necessary when a C/C++ library needs headers of
5394 another library to compile, or when a pkg-config file refers to another
5395 one @i{via} its @code{Requires} field.
5397 Another example where @code{propagated-inputs} is useful is for languages
5398 that lack a facility to record the run-time search path akin to the
5399 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5400 more. To ensure that libraries written in those languages can find
5401 library code they depend on at run time, run-time dependencies must be
5402 listed in @code{propagated-inputs} rather than @code{inputs}.
5404 @item @code{outputs} (default: @code{'("out")})
5405 The list of output names of the package. @xref{Packages with Multiple
5406 Outputs}, for typical uses of additional outputs.
5408 @item @code{native-search-paths} (default: @code{'()})
5409 @itemx @code{search-paths} (default: @code{'()})
5410 A list of @code{search-path-specification} objects describing
5411 search-path environment variables honored by the package.
5413 @item @code{replacement} (default: @code{#f})
5414 This must be either @code{#f} or a package object that will be used as a
5415 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5418 @item @code{synopsis}
5419 A one-line description of the package.
5421 @item @code{description}
5422 A more elaborate description of the package.
5424 @item @code{license}
5425 @cindex license, of packages
5426 The license of the package; a value from @code{(guix licenses)},
5427 or a list of such values.
5429 @item @code{home-page}
5430 The URL to the home-page of the package, as a string.
5432 @item @code{supported-systems} (default: @var{%supported-systems})
5433 The list of systems supported by the package, as strings of the form
5434 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5436 @item @code{maintainers} (default: @code{'()})
5437 The list of maintainers of the package, as @code{maintainer} objects.
5439 @item @code{location} (default: source location of the @code{package} form)
5440 The source location of the package. It is useful to override this when
5441 inheriting from another package, in which case this field is not
5442 automatically corrected.
5446 @deffn {Scheme Syntax} this-package
5447 When used in the @emph{lexical scope} of a package field definition, this
5448 identifier resolves to the package being defined.
5450 The example below shows how to add a package as a native input of itself when
5458 ;; When cross-compiled, Guile, for example, depends on
5459 ;; a native version of itself. Add it here.
5460 (native-inputs (if (%current-target-system)
5461 `(("self" ,this-package))
5465 It is an error to refer to @code{this-package} outside a package definition.
5468 @node origin Reference
5469 @subsection @code{origin} Reference
5471 This section summarizes all the options available in @code{origin}
5472 declarations (@pxref{Defining Packages}).
5474 @deftp {Data Type} origin
5475 This is the data type representing a source code origin.
5479 An object containing the URI of the source. The object type depends on
5480 the @code{method} (see below). For example, when using the
5481 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5482 values are: a URL represented as a string, or a list thereof.
5485 A procedure that handles the URI.
5490 @item @var{url-fetch} from @code{(guix download)}
5491 download a file from the HTTP, HTTPS, or FTP URL specified in the
5495 @item @var{git-fetch} from @code{(guix git-download)}
5496 clone the Git version control repository, and check out the revision
5497 specified in the @code{uri} field as a @code{git-reference} object; a
5498 @code{git-reference} looks like this:
5502 (url "git://git.debian.org/git/pkg-shadow/shadow")
5503 (commit "v4.1.5.1"))
5508 A bytevector containing the SHA-256 hash of the source. Typically the
5509 @code{base32} form is used here to generate the bytevector from a
5512 You can obtain this information using @code{guix download}
5513 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5516 @item @code{file-name} (default: @code{#f})
5517 The file name under which the source code should be saved. When this is
5518 @code{#f}, a sensible default value will be used in most cases. In case
5519 the source is fetched from a URL, the file name from the URL will be
5520 used. For version control checkouts, it is recommended to provide the
5521 file name explicitly because the default is not very descriptive.
5523 @item @code{patches} (default: @code{'()})
5524 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5525 file-like objects}) pointing to patches to be applied to the source.
5527 This list of patches must be unconditional. In particular, it cannot
5528 depend on the value of @code{%current-system} or
5529 @code{%current-target-system}.
5531 @item @code{snippet} (default: @code{#f})
5532 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5533 in the source directory. This is a convenient way to modify the source,
5534 sometimes more convenient than a patch.
5536 @item @code{patch-flags} (default: @code{'("-p1")})
5537 A list of command-line flags that should be passed to the @code{patch}
5540 @item @code{patch-inputs} (default: @code{#f})
5541 Input packages or derivations to the patching process. When this is
5542 @code{#f}, the usual set of inputs necessary for patching are provided,
5543 such as GNU@tie{}Patch.
5545 @item @code{modules} (default: @code{'()})
5546 A list of Guile modules that should be loaded during the patching
5547 process and while running the code in the @code{snippet} field.
5549 @item @code{patch-guile} (default: @code{#f})
5550 The Guile package that should be used in the patching process. When
5551 this is @code{#f}, a sensible default is used.
5557 @section Build Systems
5559 @cindex build system
5560 Each package definition specifies a @dfn{build system} and arguments for
5561 that build system (@pxref{Defining Packages}). This @code{build-system}
5562 field represents the build procedure of the package, as well as implicit
5563 dependencies of that build procedure.
5565 Build systems are @code{<build-system>} objects. The interface to
5566 create and manipulate them is provided by the @code{(guix build-system)}
5567 module, and actual build systems are exported by specific modules.
5569 @cindex bag (low-level package representation)
5570 Under the hood, build systems first compile package objects to
5571 @dfn{bags}. A @dfn{bag} is like a package, but with less
5572 ornamentation---in other words, a bag is a lower-level representation of
5573 a package, which includes all the inputs of that package, including some
5574 that were implicitly added by the build system. This intermediate
5575 representation is then compiled to a derivation (@pxref{Derivations}).
5577 Build systems accept an optional list of @dfn{arguments}. In package
5578 definitions, these are passed @i{via} the @code{arguments} field
5579 (@pxref{Defining Packages}). They are typically keyword arguments
5580 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
5581 Guile Reference Manual}). The value of these arguments is usually
5582 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
5583 by the daemon (@pxref{Derivations}).
5585 The main build system is @var{gnu-build-system}, which implements the
5586 standard build procedure for GNU and many other packages. It
5587 is provided by the @code{(guix build-system gnu)} module.
5589 @defvr {Scheme Variable} gnu-build-system
5590 @var{gnu-build-system} represents the GNU Build System, and variants
5591 thereof (@pxref{Configuration, configuration and makefile conventions,,
5592 standards, GNU Coding Standards}).
5594 @cindex build phases
5595 In a nutshell, packages using it are configured, built, and installed with
5596 the usual @code{./configure && make && make check && make install}
5597 command sequence. In practice, a few additional steps are often needed.
5598 All these steps are split up in separate @dfn{phases},
5599 notably@footnote{Please see the @code{(guix build gnu-build-system)}
5600 modules for more details about the build phases.}:
5604 Unpack the source tarball, and change the current directory to the
5605 extracted source tree. If the source is actually a directory, copy it
5606 to the build tree, and enter that directory.
5608 @item patch-source-shebangs
5609 Patch shebangs encountered in source files so they refer to the right
5610 store file names. For instance, this changes @code{#!/bin/sh} to
5611 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
5614 Run the @file{configure} script with a number of default options, such
5615 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
5616 by the @code{#:configure-flags} argument.
5619 Run @code{make} with the list of flags specified with
5620 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
5621 (the default), build with @code{make -j}.
5624 Run @code{make check}, or some other target specified with
5625 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
5626 @code{#:parallel-tests?} argument is true (the default), run @code{make
5630 Run @code{make install} with the flags listed in @code{#:make-flags}.
5632 @item patch-shebangs
5633 Patch shebangs on the installed executable files.
5636 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
5637 is false), copying them to the @code{debug} output when available
5638 (@pxref{Installing Debugging Files}).
5641 @vindex %standard-phases
5642 The build-side module @code{(guix build gnu-build-system)} defines
5643 @var{%standard-phases} as the default list of build phases.
5644 @var{%standard-phases} is a list of symbol/procedure pairs, where the
5645 procedure implements the actual phase.
5647 The list of phases used for a particular package can be changed with the
5648 @code{#:phases} parameter. For instance, passing:
5651 #:phases (modify-phases %standard-phases (delete 'configure))
5654 means that all the phases described above will be used, except the
5655 @code{configure} phase.
5657 In addition, this build system ensures that the ``standard'' environment
5658 for GNU packages is available. This includes tools such as GCC, libc,
5659 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
5660 build-system gnu)} module for a complete list). We call these the
5661 @dfn{implicit inputs} of a package, because package definitions do not
5662 have to mention them.
5665 Other @code{<build-system>} objects are defined to support other
5666 conventions and tools used by free software packages. They inherit most
5667 of @var{gnu-build-system}, and differ mainly in the set of inputs
5668 implicitly added to the build process, and in the list of phases
5669 executed. Some of these build systems are listed below.
5671 @defvr {Scheme Variable} ant-build-system
5672 This variable is exported by @code{(guix build-system ant)}. It
5673 implements the build procedure for Java packages that can be built with
5674 @url{http://ant.apache.org/, Ant build tool}.
5676 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
5677 provided by the @code{icedtea} package to the set of inputs. Different
5678 packages can be specified with the @code{#:ant} and @code{#:jdk}
5679 parameters, respectively.
5681 When the original package does not provide a suitable Ant build file,
5682 the parameter @code{#:jar-name} can be used to generate a minimal Ant
5683 build file @file{build.xml} with tasks to build the specified jar
5684 archive. In this case the parameter @code{#:source-dir} can be used to
5685 specify the source sub-directory, defaulting to ``src''.
5687 The @code{#:main-class} parameter can be used with the minimal ant
5688 buildfile to specify the main class of the resulting jar. This makes the
5689 jar file executable. The @code{#:test-include} parameter can be used to
5690 specify the list of junit tests to run. It defaults to
5691 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
5692 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
5693 because abstract classes cannot be run as tests.
5695 The parameter @code{#:build-target} can be used to specify the Ant task
5696 that should be run during the @code{build} phase. By default the
5697 ``jar'' task will be run.
5701 @defvr {Scheme Variable} android-ndk-build-system
5702 @cindex Android distribution
5703 @cindex Android NDK build system
5704 This variable is exported by @code{(guix build-system android-ndk)}. It
5705 implements a build procedure for Android NDK (native development kit)
5706 packages using a Guix-specific build process.
5708 The build system assumes that packages install their public interface
5709 (header) files to the subdirectory "include" of the "out" output and
5710 their libraries to the subdirectory "lib" of the "out" output.
5712 It's also assumed that the union of all the dependencies of a package
5713 has no conflicting files.
5715 For the time being, cross-compilation is not supported - so right now
5716 the libraries and header files are assumed to be host tools.
5720 @defvr {Scheme Variable} asdf-build-system/source
5721 @defvrx {Scheme Variable} asdf-build-system/sbcl
5722 @defvrx {Scheme Variable} asdf-build-system/ecl
5724 These variables, exported by @code{(guix build-system asdf)}, implement
5725 build procedures for Common Lisp packages using
5726 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
5727 definition facility for Common Lisp programs and libraries.
5729 The @code{asdf-build-system/source} system installs the packages in
5730 source form, and can be loaded using any common lisp implementation, via
5731 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
5732 systems in the format which a particular implementation understands.
5733 These build systems can also be used to produce executable programs, or
5734 lisp images which contain a set of packages pre-loaded.
5736 The build system uses naming conventions. For binary packages, the
5737 package name should be prefixed with the lisp implementation, such as
5738 @code{sbcl-} for @code{asdf-build-system/sbcl}.
5740 Additionally, the corresponding source package should be labeled using
5741 the same convention as python packages (see @ref{Python Modules}), using
5742 the @code{cl-} prefix.
5744 For binary packages, each system should be defined as a Guix package.
5745 If one package @code{origin} contains several systems, package variants
5746 can be created in order to build all the systems. Source packages,
5747 which use @code{asdf-build-system/source}, may contain several systems.
5749 In order to create executable programs and images, the build-side
5750 procedures @code{build-program} and @code{build-image} can be used.
5751 They should be called in a build phase after the @code{create-symlinks}
5752 phase, so that the system which was just built can be used within the
5753 resulting image. @code{build-program} requires a list of Common Lisp
5754 expressions to be passed as the @code{#:entry-program} argument.
5756 If the system is not defined within its own @code{.asd} file of the same
5757 name, then the @code{#:asd-file} parameter should be used to specify
5758 which file the system is defined in. Furthermore, if the package
5759 defines a system for its tests in a separate file, it will be loaded
5760 before the tests are run if it is specified by the
5761 @code{#:test-asd-file} parameter. If it is not set, the files
5762 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
5763 and @code{test.asd} will be tried if they exist.
5765 If for some reason the package must be named in a different way than the
5766 naming conventions suggest, the @code{#:asd-system-name} parameter can
5767 be used to specify the name of the system.
5771 @defvr {Scheme Variable} cargo-build-system
5772 @cindex Rust programming language
5773 @cindex Cargo (Rust build system)
5774 This variable is exported by @code{(guix build-system cargo)}. It
5775 supports builds of packages using Cargo, the build tool of the
5776 @uref{https://www.rust-lang.org, Rust programming language}.
5778 In its @code{configure} phase, this build system replaces dependencies
5779 specified in the @file{Carto.toml} file with inputs to the Guix package.
5780 The @code{install} phase installs the binaries, and it also installs the
5781 source code and @file{Cargo.toml} file.
5784 @cindex Clojure (programming language)
5785 @cindex simple Clojure build system
5786 @defvr {Scheme Variable} clojure-build-system
5787 This variable is exported by @code{(guix build-system clojure)}. It implements
5788 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
5789 using plain old @code{compile} in Clojure. Cross-compilation is not supported
5792 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
5793 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
5794 @code{#:zip} parameters, respectively.
5796 A list of source directories, test directories and jar names can be specified
5797 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
5798 parameters, respectively. Compile directory and main class can be specified
5799 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
5800 Other parameters are documented below.
5802 This build system is an extension of @var{ant-build-system}, but with the
5803 following phases changed:
5808 This phase calls @code{compile} in Clojure to compile source files and runs
5809 @command{jar} to create jars from both source files and compiled files
5810 according to the include list and exclude list specified in
5811 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
5812 has priority over the include list. These lists consist of symbols
5813 representing Clojure libraries or the special keyword @code{#:all} representing
5814 all Clojure libraries found under the source directories. The parameter
5815 @code{#:omit-source?} decides if source should be included into the jars.
5818 This phase runs tests according to the include list and exclude list specified
5819 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
5820 meanings are analogous to that of @code{#:aot-include} and
5821 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
5822 stands for all Clojure libraries found under the test directories. The
5823 parameter @code{#:tests?} decides if tests should be run.
5826 This phase installs all jars built previously.
5829 Apart from the above, this build system also contains an additional phase:
5834 This phase installs all top-level files with base name matching
5835 @var{%doc-regex}. A different regex can be specified with the
5836 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
5837 directories specified in @code{#:doc-dirs} are installed as well.
5841 @defvr {Scheme Variable} cmake-build-system
5842 This variable is exported by @code{(guix build-system cmake)}. It
5843 implements the build procedure for packages using the
5844 @url{http://www.cmake.org, CMake build tool}.
5846 It automatically adds the @code{cmake} package to the set of inputs.
5847 Which package is used can be specified with the @code{#:cmake}
5850 The @code{#:configure-flags} parameter is taken as a list of flags
5851 passed to the @command{cmake} command. The @code{#:build-type}
5852 parameter specifies in abstract terms the flags passed to the compiler;
5853 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
5854 debugging information''), which roughly means that code is compiled with
5855 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
5858 @defvr {Scheme Variable} dune-build-system
5859 This variable is exported by @code{(guix build-system dune)}. It
5860 supports builds of packages using @uref{https://dune.build/, Dune}, a build
5861 tool for the OCaml programming language. It is implemented as an extension
5862 of the @code{ocaml-build-system} which is described below. As such, the
5863 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
5866 It automatically adds the @code{dune} package to the set of inputs.
5867 Which package is used can be specified with the @code{#:dune}
5870 There is no @code{configure} phase because dune packages typically don't
5871 need to be configured. The @code{#:build-flags} parameter is taken as a
5872 list of flags passed to the @code{dune} command during the build.
5874 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
5875 command instead of the more recent @code{dune} command while building
5876 a package. Its default value is @code{#f}.
5878 The @code{#:package} parameter can be passed to specify a package name, which
5879 is useful when a package contains multiple packages and you want to build
5880 only one of them. This is equivalent to passing the @code{-p} argument to
5884 @defvr {Scheme Variable} go-build-system
5885 This variable is exported by @code{(guix build-system go)}. It
5886 implements a build procedure for Go packages using the standard
5887 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
5888 Go build mechanisms}.
5890 The user is expected to provide a value for the key @code{#:import-path}
5891 and, in some cases, @code{#:unpack-path}. The
5892 @url{https://golang.org/doc/code.html#ImportPaths, import path}
5893 corresponds to the file system path expected by the package's build
5894 scripts and any referring packages, and provides a unique way to
5895 refer to a Go package. It is typically based on a combination of the
5896 package source code's remote URI and file system hierarchy structure. In
5897 some cases, you will need to unpack the package's source code to a
5898 different directory structure than the one indicated by the import path,
5899 and @code{#:unpack-path} should be used in such cases.
5901 Packages that provide Go libraries should install their source code into
5902 the built output. The key @code{#:install-source?}, which defaults to
5903 @code{#t}, controls whether or not the source code is installed. It can
5904 be set to @code{#f} for packages that only provide executable files.
5907 @defvr {Scheme Variable} glib-or-gtk-build-system
5908 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
5909 is intended for use with packages making use of GLib or GTK+.
5911 This build system adds the following two phases to the ones defined by
5912 @var{gnu-build-system}:
5915 @item glib-or-gtk-wrap
5916 The phase @code{glib-or-gtk-wrap} ensures that programs in
5917 @file{bin/} are able to find GLib ``schemas'' and
5918 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
5919 modules}. This is achieved by wrapping the programs in launch scripts
5920 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
5921 environment variables.
5923 It is possible to exclude specific package outputs from that wrapping
5924 process by listing their names in the
5925 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
5926 when an output is known not to contain any GLib or GTK+ binaries, and
5927 where wrapping would gratuitously add a dependency of that output on
5930 @item glib-or-gtk-compile-schemas
5931 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
5932 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
5933 GSettings schemas} of GLib are compiled. Compilation is performed by the
5934 @command{glib-compile-schemas} program. It is provided by the package
5935 @code{glib:bin} which is automatically imported by the build system.
5936 The @code{glib} package providing @command{glib-compile-schemas} can be
5937 specified with the @code{#:glib} parameter.
5940 Both phases are executed after the @code{install} phase.
5943 @defvr {Scheme Variable} guile-build-system
5944 This build system is for Guile packages that consist exclusively of Scheme
5945 code and that are so lean that they don't even have a makefile, let alone a
5946 @file{configure} script. It compiles Scheme code using @command{guild
5947 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
5948 installs the @file{.scm} and @file{.go} files in the right place. It also
5949 installs documentation.
5951 This build system supports cross-compilation by using the @code{--target}
5952 option of @command{guild compile}.
5954 Packages built with @code{guile-build-system} must provide a Guile package in
5955 their @code{native-inputs} field.
5958 @defvr {Scheme Variable} minify-build-system
5959 This variable is exported by @code{(guix build-system minify)}. It
5960 implements a minification procedure for simple JavaScript packages.
5962 It adds @code{uglify-js} to the set of inputs and uses it to compress
5963 all JavaScript files in the @file{src} directory. A different minifier
5964 package can be specified with the @code{#:uglify-js} parameter, but it
5965 is expected that the package writes the minified code to the standard
5968 When the input JavaScript files are not all located in the @file{src}
5969 directory, the parameter @code{#:javascript-files} can be used to
5970 specify a list of file names to feed to the minifier.
5973 @defvr {Scheme Variable} ocaml-build-system
5974 This variable is exported by @code{(guix build-system ocaml)}. It implements
5975 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
5976 of choosing the correct set of commands to run for each package. OCaml
5977 packages can expect many different commands to be run. This build system will
5980 When the package has a @file{setup.ml} file present at the top-level, it will
5981 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
5982 @code{ocaml setup.ml -install}. The build system will assume that this file
5983 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
5984 care of setting the prefix and enabling tests if they are not disabled. You
5985 can pass configure and build flags with the @code{#:configure-flags} and
5986 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
5987 set of flags used to enable tests. The @code{#:use-make?} key can be used to
5988 bypass this system in the build and install phases.
5990 When the package has a @file{configure} file, it is assumed that it is a
5991 hand-made configure script that requires a different argument format than
5992 in the @code{gnu-build-system}. You can add more flags with the
5993 @code{#:configure-flags} key.
5995 When the package has a @file{Makefile} file (or @code{#:use-make?} is
5996 @code{#t}), it will be used and more flags can be passed to the build and
5997 install phases with the @code{#:make-flags} key.
5999 Finally, some packages do not have these files and use a somewhat standard
6000 location for its build system. In that case, the build system will run
6001 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6002 providing the path to the required findlib module. Additional flags can
6003 be passed via the @code{#:build-flags} key. Install is taken care of by
6004 @command{opam-installer}. In this case, the @code{opam} package must
6005 be added to the @code{native-inputs} field of the package definition.
6007 Note that most OCaml packages assume they will be installed in the same
6008 directory as OCaml, which is not what we want in guix. In particular, they
6009 will install @file{.so} files in their module's directory, which is usually
6010 fine because it is in the OCaml compiler directory. In guix though, these
6011 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
6012 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6013 @file{.so} libraries should be installed.
6016 @defvr {Scheme Variable} python-build-system
6017 This variable is exported by @code{(guix build-system python)}. It
6018 implements the more or less standard build procedure used by Python
6019 packages, which consists in running @code{python setup.py build} and
6020 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6022 For packages that install stand-alone Python programs under @code{bin/},
6023 it takes care of wrapping these programs so that their @code{PYTHONPATH}
6024 environment variable points to all the Python libraries they depend on.
6026 Which Python package is used to perform the build can be specified with
6027 the @code{#:python} parameter. This is a useful way to force a package
6028 to be built for a specific version of the Python interpreter, which
6029 might be necessary if the package is only compatible with a single
6030 interpreter version.
6032 By default guix calls @code{setup.py} under control of
6033 @code{setuptools}, much like @command{pip} does. Some packages are not
6034 compatible with setuptools (and pip), thus you can disable this by
6035 setting the @code{#:use-setuptools} parameter to @code{#f}.
6038 @defvr {Scheme Variable} perl-build-system
6039 This variable is exported by @code{(guix build-system perl)}. It
6040 implements the standard build procedure for Perl packages, which either
6041 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6042 followed by @code{Build} and @code{Build install}; or in running
6043 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6044 @code{make} and @code{make install}, depending on which of
6045 @code{Build.PL} or @code{Makefile.PL} is present in the package
6046 distribution. Preference is given to the former if both @code{Build.PL}
6047 and @code{Makefile.PL} exist in the package distribution. This
6048 preference can be reversed by specifying @code{#t} for the
6049 @code{#:make-maker?} parameter.
6051 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6052 passes flags specified by the @code{#:make-maker-flags} or
6053 @code{#:module-build-flags} parameter, respectively.
6055 Which Perl package is used can be specified with @code{#:perl}.
6058 @defvr {Scheme Variable} r-build-system
6059 This variable is exported by @code{(guix build-system r)}. It
6060 implements the build procedure used by @uref{http://r-project.org, R}
6061 packages, which essentially is little more than running @code{R CMD
6062 INSTALL --library=/gnu/store/@dots{}} in an environment where
6063 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6064 are run after installation using the R function
6065 @code{tools::testInstalledPackage}.
6068 @defvr {Scheme Variable} rakudo-build-system
6069 This variable is exported by @code{(guix build-system rakudo)} It
6070 implements the build procedure used by @uref{https://rakudo.org/,
6071 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6072 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6073 installs the binaries, library files and the resources, as well as wrap
6074 the files under the @code{bin/} directory. Tests can be skipped by
6075 passing @code{#f} to the @code{tests?} parameter.
6077 Which rakudo package is used can be specified with @code{rakudo}.
6078 Which perl6-tap-harness package used for the tests can be specified with
6079 @code{#:prove6} or removed by passing @code{#f} to the
6080 @code{with-prove6?} parameter.
6081 Which perl6-zef package used for tests and installing can be specified
6082 with @code{#:zef} or removed by passing @code{#f} to the
6083 @code{with-zef?} parameter.
6086 @defvr {Scheme Variable} texlive-build-system
6087 This variable is exported by @code{(guix build-system texlive)}. It is
6088 used to build TeX packages in batch mode with a specified engine. The
6089 build system sets the @code{TEXINPUTS} variable to find all TeX source
6090 files in the inputs.
6092 By default it runs @code{luatex} on all files ending on @code{ins}. A
6093 different engine and format can be specified with the
6094 @code{#:tex-format} argument. Different build targets can be specified
6095 with the @code{#:build-targets} argument, which expects a list of file
6096 names. The build system adds only @code{texlive-bin} and
6097 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6098 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6099 and @code{#:texlive-latex-base}, respectively.
6101 The @code{#:tex-directory} parameter tells the build system where to
6102 install the built files under the texmf tree.
6105 @defvr {Scheme Variable} ruby-build-system
6106 This variable is exported by @code{(guix build-system ruby)}. It
6107 implements the RubyGems build procedure used by Ruby packages, which
6108 involves running @code{gem build} followed by @code{gem install}.
6110 The @code{source} field of a package that uses this build system
6111 typically references a gem archive, since this is the format that Ruby
6112 developers use when releasing their software. The build system unpacks
6113 the gem archive, potentially patches the source, runs the test suite,
6114 repackages the gem, and installs it. Additionally, directories and
6115 tarballs may be referenced to allow building unreleased gems from Git or
6116 a traditional source release tarball.
6118 Which Ruby package is used can be specified with the @code{#:ruby}
6119 parameter. A list of additional flags to be passed to the @command{gem}
6120 command can be specified with the @code{#:gem-flags} parameter.
6123 @defvr {Scheme Variable} waf-build-system
6124 This variable is exported by @code{(guix build-system waf)}. It
6125 implements a build procedure around the @code{waf} script. The common
6126 phases---@code{configure}, @code{build}, and @code{install}---are
6127 implemented by passing their names as arguments to the @code{waf}
6130 The @code{waf} script is executed by the Python interpreter. Which
6131 Python package is used to run the script can be specified with the
6132 @code{#:python} parameter.
6135 @defvr {Scheme Variable} scons-build-system
6136 This variable is exported by @code{(guix build-system scons)}. It
6137 implements the build procedure used by the SCons software construction
6138 tool. This build system runs @code{scons} to build the package,
6139 @code{scons test} to run tests, and then @code{scons install} to install
6142 Additional flags to be passed to @code{scons} can be specified with the
6143 @code{#:scons-flags} parameter. The version of Python used to run SCons
6144 can be specified by selecting the appropriate SCons package with the
6145 @code{#:scons} parameter.
6148 @defvr {Scheme Variable} haskell-build-system
6149 This variable is exported by @code{(guix build-system haskell)}. It
6150 implements the Cabal build procedure used by Haskell packages, which
6151 involves running @code{runhaskell Setup.hs configure
6152 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6153 Instead of installing the package by running @code{runhaskell Setup.hs
6154 install}, to avoid trying to register libraries in the read-only
6155 compiler store directory, the build system uses @code{runhaskell
6156 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6157 addition, the build system generates the package documentation by
6158 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6159 is passed. Optional Haddock parameters can be passed with the help of
6160 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6161 not found, the build system looks for @code{Setup.lhs} instead.
6163 Which Haskell compiler is used can be specified with the @code{#:haskell}
6164 parameter which defaults to @code{ghc}.
6167 @defvr {Scheme Variable} dub-build-system
6168 This variable is exported by @code{(guix build-system dub)}. It
6169 implements the Dub build procedure used by D packages, which
6170 involves running @code{dub build} and @code{dub run}.
6171 Installation is done by copying the files manually.
6173 Which D compiler is used can be specified with the @code{#:ldc}
6174 parameter which defaults to @code{ldc}.
6177 @defvr {Scheme Variable} emacs-build-system
6178 This variable is exported by @code{(guix build-system emacs)}. It
6179 implements an installation procedure similar to the packaging system
6180 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6182 It first creates the @code{@var{package}-autoloads.el} file, then it
6183 byte compiles all Emacs Lisp files. Differently from the Emacs
6184 packaging system, the Info documentation files are moved to the standard
6185 documentation directory and the @file{dir} file is deleted. Each
6186 package is installed in its own directory under
6187 @file{share/emacs/site-lisp/guix.d}.
6190 @defvr {Scheme Variable} font-build-system
6191 This variable is exported by @code{(guix build-system font)}. It
6192 implements an installation procedure for font packages where upstream
6193 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6194 need to be copied into place. It copies font files to standard
6195 locations in the output directory.
6198 @defvr {Scheme Variable} meson-build-system
6199 This variable is exported by @code{(guix build-system meson)}. It
6200 implements the build procedure for packages that use
6201 @url{http://mesonbuild.com, Meson} as their build system.
6203 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6204 of inputs, and they can be changed with the parameters @code{#:meson}
6205 and @code{#:ninja} if needed. The default Meson is
6206 @code{meson-for-build}, which is special because it doesn't clear the
6207 @code{RUNPATH} of binaries and libraries when they are installed.
6209 This build system is an extension of @var{gnu-build-system}, but with the
6210 following phases changed to some specific for Meson:
6215 The phase runs @code{meson} with the flags specified in
6216 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6217 @code{plain} unless something else is specified in @code{#:build-type}.
6220 The phase runs @code{ninja} to build the package in parallel by default, but
6221 this can be changed with @code{#:parallel-build?}.
6224 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6225 which is @code{"test"} by default.
6228 The phase runs @code{ninja install} and can not be changed.
6231 Apart from that, the build system also adds the following phases:
6236 This phase ensures that all binaries can find the libraries they need.
6237 It searches for required libraries in subdirectories of the package being
6238 built, and adds those to @code{RUNPATH} where needed. It also removes
6239 references to libraries left over from the build phase by
6240 @code{meson-for-build}, such as test dependencies, that aren't actually
6241 required for the program to run.
6243 @item glib-or-gtk-wrap
6244 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6245 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6247 @item glib-or-gtk-compile-schemas
6248 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6249 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6253 @defvr {Scheme Variable} linux-module-build-system
6254 @var{linux-module-build-system} allows building Linux kernel modules.
6256 @cindex build phases
6257 This build system is an extension of @var{gnu-build-system}, but with the
6258 following phases changed:
6263 This phase configures the environment so that the Linux kernel's Makefile
6264 can be used to build the external kernel module.
6267 This phase uses the Linux kernel's Makefile in order to build the external
6271 This phase uses the Linux kernel's Makefile in order to install the external
6275 It is possible and useful to specify the Linux kernel to use for building
6276 the module (in the "arguments" form of a package using the
6277 linux-module-build-system, use the key #:linux to specify it).
6280 Lastly, for packages that do not need anything as sophisticated, a
6281 ``trivial'' build system is provided. It is trivial in the sense that
6282 it provides basically no support: it does not pull any implicit inputs,
6283 and does not have a notion of build phases.
6285 @defvr {Scheme Variable} trivial-build-system
6286 This variable is exported by @code{(guix build-system trivial)}.
6288 This build system requires a @code{#:builder} argument. This argument
6289 must be a Scheme expression that builds the package output(s)---as
6290 with @code{build-expression->derivation} (@pxref{Derivations,
6291 @code{build-expression->derivation}}).
6301 Conceptually, the @dfn{store} is the place where derivations that have
6302 been built successfully are stored---by default, @file{/gnu/store}.
6303 Sub-directories in the store are referred to as @dfn{store items} or
6304 sometimes @dfn{store paths}. The store has an associated database that
6305 contains information such as the store paths referred to by each store
6306 path, and the list of @emph{valid} store items---results of successful
6307 builds. This database resides in @file{@var{localstatedir}/guix/db},
6308 where @var{localstatedir} is the state directory specified @i{via}
6309 @option{--localstatedir} at configure time, usually @file{/var}.
6311 The store is @emph{always} accessed by the daemon on behalf of its clients
6312 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6313 connect to the daemon over a Unix-domain socket, send requests to it,
6314 and read the result---these are remote procedure calls, or RPCs.
6317 Users must @emph{never} modify files under @file{/gnu/store} directly.
6318 This would lead to inconsistencies and break the immutability
6319 assumptions of Guix's functional model (@pxref{Introduction}).
6321 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6322 how to check the integrity of the store and attempt recovery from
6323 accidental modifications.
6326 The @code{(guix store)} module provides procedures to connect to the
6327 daemon, and to perform RPCs. These are described below. By default,
6328 @code{open-connection}, and thus all the @command{guix} commands,
6329 connect to the local daemon or to the URI specified by the
6330 @code{GUIX_DAEMON_SOCKET} environment variable.
6332 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6333 When set, the value of this variable should be a file name or a URI
6334 designating the daemon endpoint. When it is a file name, it denotes a
6335 Unix-domain socket to connect to. In addition to file names, the
6336 supported URI schemes are:
6341 These are for Unix-domain sockets.
6342 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6343 @file{/var/guix/daemon-socket/socket}.
6346 @cindex daemon, remote access
6347 @cindex remote access to the daemon
6348 @cindex daemon, cluster setup
6349 @cindex clusters, daemon setup
6350 These URIs denote connections over TCP/IP, without encryption nor
6351 authentication of the remote host. The URI must specify the host name
6352 and optionally a port number (by default port 44146 is used):
6355 guix://master.guix.example.org:1234
6358 This setup is suitable on local networks, such as clusters, where only
6359 trusted nodes may connect to the build daemon at
6360 @code{master.guix.example.org}.
6362 The @code{--listen} option of @command{guix-daemon} can be used to
6363 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6367 @cindex SSH access to build daemons
6368 These URIs allow you to connect to a remote daemon over
6369 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
6370 A typical URL might look like this:
6373 ssh://charlie@@guix.example.org:22
6376 As for @command{guix copy}, the usual OpenSSH client configuration files
6377 are honored (@pxref{Invoking guix copy}).
6380 Additional URI schemes may be supported in the future.
6382 @c XXX: Remove this note when the protocol incurs fewer round trips
6383 @c and when (guix derivations) no longer relies on file system access.
6385 The ability to connect to remote build daemons is considered
6386 experimental as of @value{VERSION}. Please get in touch with us to
6387 share any problems or suggestions you may have (@pxref{Contributing}).
6391 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6392 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6393 @var{reserve-space?} is true, instruct it to reserve a little bit of
6394 extra space on the file system so that the garbage collector can still
6395 operate should the disk become full. Return a server object.
6397 @var{file} defaults to @var{%default-socket-path}, which is the normal
6398 location given the options that were passed to @command{configure}.
6401 @deffn {Scheme Procedure} close-connection @var{server}
6402 Close the connection to @var{server}.
6405 @defvr {Scheme Variable} current-build-output-port
6406 This variable is bound to a SRFI-39 parameter, which refers to the port
6407 where build and error logs sent by the daemon should be written.
6410 Procedures that make RPCs all take a server object as their first
6413 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6414 @cindex invalid store items
6415 Return @code{#t} when @var{path} designates a valid store item and
6416 @code{#f} otherwise (an invalid item may exist on disk but still be
6417 invalid, for instance because it is the result of an aborted or failed
6420 A @code{&store-protocol-error} condition is raised if @var{path} is not
6421 prefixed by the store directory (@file{/gnu/store}).
6424 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6425 Add @var{text} under file @var{name} in the store, and return its store
6426 path. @var{references} is the list of store paths referred to by the
6427 resulting store path.
6430 @deffn {Scheme Procedure} build-derivations @var{server} @var{derivations}
6431 Build @var{derivations} (a list of @code{<derivation>} objects or
6432 derivation paths), and return when the worker is done building them.
6433 Return @code{#t} on success.
6436 Note that the @code{(guix monads)} module provides a monad as well as
6437 monadic versions of the above procedures, with the goal of making it
6438 more convenient to work with code that accesses the store (@pxref{The
6442 @i{This section is currently incomplete.}
6445 @section Derivations
6448 Low-level build actions and the environment in which they are performed
6449 are represented by @dfn{derivations}. A derivation contains the
6450 following pieces of information:
6454 The outputs of the derivation---derivations produce at least one file or
6455 directory in the store, but may produce more.
6458 @cindex build-time dependencies
6459 @cindex dependencies, build-time
6460 The inputs of the derivations---i.e., its build-time dependencies---which may
6461 be other derivations or plain files in the store (patches, build scripts,
6465 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
6468 The file name of a build script in the store, along with the arguments
6472 A list of environment variables to be defined.
6476 @cindex derivation path
6477 Derivations allow clients of the daemon to communicate build actions to
6478 the store. They exist in two forms: as an in-memory representation,
6479 both on the client- and daemon-side, and as files in the store whose
6480 name end in @code{.drv}---these files are referred to as @dfn{derivation
6481 paths}. Derivations paths can be passed to the @code{build-derivations}
6482 procedure to perform the build actions they prescribe (@pxref{The
6485 @cindex fixed-output derivations
6486 Operations such as file downloads and version-control checkouts for
6487 which the expected content hash is known in advance are modeled as
6488 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
6489 of a fixed-output derivation are independent of its inputs---e.g., a
6490 source code download produces the same result regardless of the download
6491 method and tools being used.
6494 @cindex run-time dependencies
6495 @cindex dependencies, run-time
6496 The outputs of derivations---i.e., the build results---have a set of
6497 @dfn{references}, as reported by the @code{references} RPC or the
6498 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
6499 are the set of run-time dependencies of the build results. References are a
6500 subset of the inputs of the derivation; this subset is automatically computed
6501 by the build daemon by scanning all the files in the outputs.
6503 The @code{(guix derivations)} module provides a representation of
6504 derivations as Scheme objects, along with procedures to create and
6505 otherwise manipulate derivations. The lowest-level primitive to create
6506 a derivation is the @code{derivation} procedure:
6508 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
6509 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6510 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
6511 [#:system (%current-system)] [#:references-graphs #f] @
6512 [#:allowed-references #f] [#:disallowed-references #f] @
6513 [#:leaked-env-vars #f] [#:local-build? #f] @
6514 [#:substitutable? #t] [#:properties '()]
6515 Build a derivation with the given arguments, and return the resulting
6516 @code{<derivation>} object.
6518 When @var{hash} and @var{hash-algo} are given, a
6519 @dfn{fixed-output derivation} is created---i.e., one whose result is
6520 known in advance, such as a file download. If, in addition,
6521 @var{recursive?} is true, then that fixed output may be an executable
6522 file or a directory and @var{hash} must be the hash of an archive
6523 containing this output.
6525 When @var{references-graphs} is true, it must be a list of file
6526 name/store path pairs. In that case, the reference graph of each store
6527 path is exported in the build environment in the corresponding file, in
6528 a simple text format.
6530 When @var{allowed-references} is true, it must be a list of store items
6531 or outputs that the derivation's output may refer to. Likewise,
6532 @var{disallowed-references}, if true, must be a list of things the
6533 outputs may @emph{not} refer to.
6535 When @var{leaked-env-vars} is true, it must be a list of strings
6536 denoting environment variables that are allowed to ``leak'' from the
6537 daemon's environment to the build environment. This is only applicable
6538 to fixed-output derivations---i.e., when @var{hash} is true. The main
6539 use is to allow variables such as @code{http_proxy} to be passed to
6540 derivations that download files.
6542 When @var{local-build?} is true, declare that the derivation is not a
6543 good candidate for offloading and should rather be built locally
6544 (@pxref{Daemon Offload Setup}). This is the case for small derivations
6545 where the costs of data transfers would outweigh the benefits.
6547 When @var{substitutable?} is false, declare that substitutes of the
6548 derivation's output should not be used (@pxref{Substitutes}). This is
6549 useful, for instance, when building packages that capture details of the
6550 host CPU instruction set.
6552 @var{properties} must be an association list describing ``properties'' of the
6553 derivation. It is kept as-is, uninterpreted, in the derivation.
6557 Here's an example with a shell script as its builder, assuming
6558 @var{store} is an open connection to the daemon, and @var{bash} points
6559 to a Bash executable in the store:
6562 (use-modules (guix utils)
6566 (let ((builder ; add the Bash script to the store
6567 (add-text-to-store store "my-builder.sh"
6568 "echo hello world > $out\n" '())))
6569 (derivation store "foo"
6570 bash `("-e" ,builder)
6571 #:inputs `((,bash) (,builder))
6572 #:env-vars '(("HOME" . "/homeless"))))
6573 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
6576 As can be guessed, this primitive is cumbersome to use directly. A
6577 better approach is to write build scripts in Scheme, of course! The
6578 best course of action for that is to write the build code as a
6579 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
6580 information, @pxref{G-Expressions}.
6582 Once upon a time, @code{gexp->derivation} did not exist and constructing
6583 derivations with build code written in Scheme was achieved with
6584 @code{build-expression->derivation}, documented below. This procedure
6585 is now deprecated in favor of the much nicer @code{gexp->derivation}.
6587 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
6588 @var{name} @var{exp} @
6589 [#:system (%current-system)] [#:inputs '()] @
6590 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6591 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
6592 [#:references-graphs #f] [#:allowed-references #f] @
6593 [#:disallowed-references #f] @
6594 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
6595 Return a derivation that executes Scheme expression @var{exp} as a
6596 builder for derivation @var{name}. @var{inputs} must be a list of
6597 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
6598 @code{"out"} is assumed. @var{modules} is a list of names of Guile
6599 modules from the current search path to be copied in the store,
6600 compiled, and made available in the load path during the execution of
6601 @var{exp}---e.g., @code{((guix build utils) (guix build
6602 gnu-build-system))}.
6604 @var{exp} is evaluated in an environment where @code{%outputs} is bound
6605 to a list of output/path pairs, and where @code{%build-inputs} is bound
6606 to a list of string/output-path pairs made from @var{inputs}.
6607 Optionally, @var{env-vars} is a list of string pairs specifying the name
6608 and value of environment variables visible to the builder. The builder
6609 terminates by passing the result of @var{exp} to @code{exit}; thus, when
6610 @var{exp} returns @code{#f}, the build is considered to have failed.
6612 @var{exp} is built using @var{guile-for-build} (a derivation). When
6613 @var{guile-for-build} is omitted or is @code{#f}, the value of the
6614 @code{%guile-for-build} fluid is used instead.
6616 See the @code{derivation} procedure for the meaning of
6617 @var{references-graphs}, @var{allowed-references},
6618 @var{disallowed-references}, @var{local-build?}, and
6619 @var{substitutable?}.
6623 Here's an example of a single-output derivation that creates a directory
6624 containing one file:
6627 (let ((builder '(let ((out (assoc-ref %outputs "out")))
6628 (mkdir out) ; create /gnu/store/@dots{}-goo
6629 (call-with-output-file (string-append out "/test")
6631 (display '(hello guix) p))))))
6632 (build-expression->derivation store "goo" builder))
6634 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
6638 @node The Store Monad
6639 @section The Store Monad
6643 The procedures that operate on the store described in the previous
6644 sections all take an open connection to the build daemon as their first
6645 argument. Although the underlying model is functional, they either have
6646 side effects or depend on the current state of the store.
6648 The former is inconvenient: the connection to the build daemon has to be
6649 carried around in all those functions, making it impossible to compose
6650 functions that do not take that parameter with functions that do. The
6651 latter can be problematic: since store operations have side effects
6652 and/or depend on external state, they have to be properly sequenced.
6654 @cindex monadic values
6655 @cindex monadic functions
6656 This is where the @code{(guix monads)} module comes in. This module
6657 provides a framework for working with @dfn{monads}, and a particularly
6658 useful monad for our uses, the @dfn{store monad}. Monads are a
6659 construct that allows two things: associating ``context'' with values
6660 (in our case, the context is the store), and building sequences of
6661 computations (here computations include accesses to the store). Values
6662 in a monad---values that carry this additional context---are called
6663 @dfn{monadic values}; procedures that return such values are called
6664 @dfn{monadic procedures}.
6666 Consider this ``normal'' procedure:
6669 (define (sh-symlink store)
6670 ;; Return a derivation that symlinks the 'bash' executable.
6671 (let* ((drv (package-derivation store bash))
6672 (out (derivation->output-path drv))
6673 (sh (string-append out "/bin/bash")))
6674 (build-expression->derivation store "sh"
6675 `(symlink ,sh %output))))
6678 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
6679 as a monadic function:
6682 (define (sh-symlink)
6683 ;; Same, but return a monadic value.
6684 (mlet %store-monad ((drv (package->derivation bash)))
6685 (gexp->derivation "sh"
6686 #~(symlink (string-append #$drv "/bin/bash")
6690 There are several things to note in the second version: the @code{store}
6691 parameter is now implicit and is ``threaded'' in the calls to the
6692 @code{package->derivation} and @code{gexp->derivation} monadic
6693 procedures, and the monadic value returned by @code{package->derivation}
6694 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
6696 As it turns out, the call to @code{package->derivation} can even be
6697 omitted since it will take place implicitly, as we will see later
6698 (@pxref{G-Expressions}):
6701 (define (sh-symlink)
6702 (gexp->derivation "sh"
6703 #~(symlink (string-append #$bash "/bin/bash")
6708 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
6709 @c for the funny quote.
6710 Calling the monadic @code{sh-symlink} has no effect. As someone once
6711 said, ``you exit a monad like you exit a building on fire: by running''.
6712 So, to exit the monad and get the desired effect, one must use
6713 @code{run-with-store}:
6716 (run-with-store (open-connection) (sh-symlink))
6717 @result{} /gnu/store/...-sh-symlink
6720 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
6721 new ``meta-commands'' to make it easier to deal with monadic procedures:
6722 @code{run-in-store}, and @code{enter-store-monad}. The former is used
6723 to ``run'' a single monadic value through the store:
6726 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
6727 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6730 The latter enters a recursive REPL, where all the return values are
6731 automatically run through the store:
6734 scheme@@(guile-user)> ,enter-store-monad
6735 store-monad@@(guile-user) [1]> (package->derivation hello)
6736 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6737 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
6738 $3 = "/gnu/store/@dots{}-foo"
6739 store-monad@@(guile-user) [1]> ,q
6740 scheme@@(guile-user)>
6744 Note that non-monadic values cannot be returned in the
6745 @code{store-monad} REPL.
6747 The main syntactic forms to deal with monads in general are provided by
6748 the @code{(guix monads)} module and are described below.
6750 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
6751 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
6755 @deffn {Scheme Syntax} return @var{val}
6756 Return a monadic value that encapsulates @var{val}.
6759 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
6760 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
6761 procedures @var{mproc}@dots{}@footnote{This operation is commonly
6762 referred to as ``bind'', but that name denotes an unrelated procedure in
6763 Guile. Thus we use this somewhat cryptic symbol inherited from the
6764 Haskell language.}. There can be one @var{mproc} or several of them, as
6769 (with-monad %state-monad
6771 (lambda (x) (return (+ 1 x)))
6772 (lambda (x) (return (* 2 x)))))
6776 @result{} some-state
6780 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
6782 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
6784 Bind the variables @var{var} to the monadic values @var{mval} in
6785 @var{body}, which is a sequence of expressions. As with the bind
6786 operator, this can be thought of as ``unpacking'' the raw, non-monadic
6787 value ``contained'' in @var{mval} and making @var{var} refer to that
6788 raw, non-monadic value within the scope of the @var{body}. The form
6789 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
6790 @var{val}, as per @code{let}. The binding operations occur in sequence
6791 from left to right. The last expression of @var{body} must be a monadic
6792 expression, and its result will become the result of the @code{mlet} or
6793 @code{mlet*} when run in the @var{monad}.
6795 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
6796 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
6799 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
6800 Bind @var{mexp} and the following monadic expressions in sequence,
6801 returning the result of the last expression. Every expression in the
6802 sequence must be a monadic expression.
6804 This is akin to @code{mlet}, except that the return values of the
6805 monadic expressions are ignored. In that sense, it is analogous to
6806 @code{begin}, but applied to monadic expressions.
6809 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
6810 When @var{condition} is true, evaluate the sequence of monadic
6811 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6812 @var{condition} is false, return @code{*unspecified*} in the current
6813 monad. Every expression in the sequence must be a monadic expression.
6816 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
6817 When @var{condition} is false, evaluate the sequence of monadic
6818 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6819 @var{condition} is true, return @code{*unspecified*} in the current
6820 monad. Every expression in the sequence must be a monadic expression.
6824 The @code{(guix monads)} module provides the @dfn{state monad}, which
6825 allows an additional value---the state---to be @emph{threaded} through
6826 monadic procedure calls.
6828 @defvr {Scheme Variable} %state-monad
6829 The state monad. Procedures in the state monad can access and change
6830 the state that is threaded.
6832 Consider the example below. The @code{square} procedure returns a value
6833 in the state monad. It returns the square of its argument, but also
6834 increments the current state value:
6838 (mlet %state-monad ((count (current-state)))
6839 (mbegin %state-monad
6840 (set-current-state (+ 1 count))
6843 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
6848 When ``run'' through @var{%state-monad}, we obtain that additional state
6849 value, which is the number of @code{square} calls.
6852 @deffn {Monadic Procedure} current-state
6853 Return the current state as a monadic value.
6856 @deffn {Monadic Procedure} set-current-state @var{value}
6857 Set the current state to @var{value} and return the previous state as a
6861 @deffn {Monadic Procedure} state-push @var{value}
6862 Push @var{value} to the current state, which is assumed to be a list,
6863 and return the previous state as a monadic value.
6866 @deffn {Monadic Procedure} state-pop
6867 Pop a value from the current state and return it as a monadic value.
6868 The state is assumed to be a list.
6871 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
6872 Run monadic value @var{mval} starting with @var{state} as the initial
6873 state. Return two values: the resulting value, and the resulting state.
6876 The main interface to the store monad, provided by the @code{(guix
6877 store)} module, is as follows.
6879 @defvr {Scheme Variable} %store-monad
6880 The store monad---an alias for @var{%state-monad}.
6882 Values in the store monad encapsulate accesses to the store. When its
6883 effect is needed, a value of the store monad must be ``evaluated'' by
6884 passing it to the @code{run-with-store} procedure (see below.)
6887 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
6888 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
6889 open store connection.
6892 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
6893 Return as a monadic value the absolute file name in the store of the file
6894 containing @var{text}, a string. @var{references} is a list of store items that the
6895 resulting text file refers to; it defaults to the empty list.
6898 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
6899 Return as a monadic value the absolute file name in the store of the file
6900 containing @var{data}, a bytevector. @var{references} is a list of store
6901 items that the resulting binary file refers to; it defaults to the empty list.
6904 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
6905 [#:recursive? #t] [#:select? (const #t)]
6906 Return the name of @var{file} once interned in the store. Use
6907 @var{name} as its store name, or the basename of @var{file} if
6908 @var{name} is omitted.
6910 When @var{recursive?} is true, the contents of @var{file} are added
6911 recursively; if @var{file} designates a flat file and @var{recursive?}
6912 is true, its contents are added, and its permission bits are kept.
6914 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
6915 @var{stat})} for each directory entry, where @var{file} is the entry's
6916 absolute file name and @var{stat} is the result of @code{lstat}; exclude
6917 entries for which @var{select?} does not return true.
6919 The example below adds a file to the store, under two different names:
6922 (run-with-store (open-connection)
6923 (mlet %store-monad ((a (interned-file "README"))
6924 (b (interned-file "README" "LEGU-MIN")))
6925 (return (list a b))))
6927 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
6932 The @code{(guix packages)} module exports the following package-related
6935 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
6936 [#:system (%current-system)] [#:target #f] @
6939 value in the absolute file name of @var{file} within the @var{output}
6940 directory of @var{package}. When @var{file} is omitted, return the name
6941 of the @var{output} directory of @var{package}. When @var{target} is
6942 true, use it as a cross-compilation target triplet.
6945 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
6946 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
6947 @var{target} [@var{system}]
6948 Monadic version of @code{package-derivation} and
6949 @code{package-cross-derivation} (@pxref{Defining Packages}).
6954 @section G-Expressions
6956 @cindex G-expression
6957 @cindex build code quoting
6958 So we have ``derivations'', which represent a sequence of build actions
6959 to be performed to produce an item in the store (@pxref{Derivations}).
6960 These build actions are performed when asking the daemon to actually
6961 build the derivations; they are run by the daemon in a container
6962 (@pxref{Invoking guix-daemon}).
6964 @cindex strata of code
6965 It should come as no surprise that we like to write these build actions
6966 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
6967 code@footnote{The term @dfn{stratum} in this context was coined by
6968 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
6969 Kiselyov, who has written insightful
6970 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
6971 on this topic}, refers to this kind of code generation as
6972 @dfn{staging}.}: the ``host code''---code that defines packages, talks
6973 to the daemon, etc.---and the ``build code''---code that actually
6974 performs build actions, such as making directories, invoking
6975 @command{make}, etc.
6977 To describe a derivation and its build actions, one typically needs to
6978 embed build code inside host code. It boils down to manipulating build
6979 code as data, and the homoiconicity of Scheme---code has a direct
6980 representation as data---comes in handy for that. But we need more than
6981 the normal @code{quasiquote} mechanism in Scheme to construct build
6984 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
6985 S-expressions adapted to build expressions. G-expressions, or
6986 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
6987 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
6988 @code{#$}, and @code{#$@@}), which are comparable to
6989 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
6990 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
6991 GNU Guile Reference Manual}). However, there are major differences:
6995 Gexps are meant to be written to a file and run or manipulated by other
6999 When a high-level object such as a package or derivation is unquoted
7000 inside a gexp, the result is as if its output file name had been
7004 Gexps carry information about the packages or derivations they refer to,
7005 and these dependencies are automatically added as inputs to the build
7006 processes that use them.
7009 @cindex lowering, of high-level objects in gexps
7010 This mechanism is not limited to package and derivation
7011 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7012 derivations or files in the store can be defined,
7013 such that these objects can also be inserted
7014 into gexps. For example, a useful type of high-level objects that can be
7015 inserted in a gexp is ``file-like objects'', which make it easy to
7016 add files to the store and to refer to them in
7017 derivations and such (see @code{local-file} and @code{plain-file}
7020 To illustrate the idea, here is an example of a gexp:
7027 (symlink (string-append #$coreutils "/bin/ls")
7031 This gexp can be passed to @code{gexp->derivation}; we obtain a
7032 derivation that builds a directory containing exactly one symlink to
7033 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7036 (gexp->derivation "the-thing" build-exp)
7039 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7040 substituted to the reference to the @var{coreutils} package in the
7041 actual build code, and @var{coreutils} is automatically made an input to
7042 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7043 output)}) is replaced by a string containing the directory name of the
7044 output of the derivation.
7046 @cindex cross compilation
7047 In a cross-compilation context, it is useful to distinguish between
7048 references to the @emph{native} build of a package---that can run on the
7049 host---versus references to cross builds of a package. To that end, the
7050 @code{#+} plays the same role as @code{#$}, but is a reference to a
7051 native package build:
7054 (gexp->derivation "vi"
7057 (system* (string-append #+coreutils "/bin/ln")
7059 (string-append #$emacs "/bin/emacs")
7060 (string-append #$output "/bin/vi")))
7061 #:target "mips64el-linux-gnu")
7065 In the example above, the native build of @var{coreutils} is used, so
7066 that @command{ln} can actually run on the host; but then the
7067 cross-compiled build of @var{emacs} is referenced.
7069 @cindex imported modules, for gexps
7070 @findex with-imported-modules
7071 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7072 able to use certain Guile modules from the ``host environment'' in the
7073 gexp, so those modules should be imported in the ``build environment''.
7074 The @code{with-imported-modules} form allows you to express that:
7077 (let ((build (with-imported-modules '((guix build utils))
7079 (use-modules (guix build utils))
7080 (mkdir-p (string-append #$output "/bin"))))))
7081 (gexp->derivation "empty-dir"
7084 (display "success!\n")
7089 In this example, the @code{(guix build utils)} module is automatically
7090 pulled into the isolated build environment of our gexp, such that
7091 @code{(use-modules (guix build utils))} works as expected.
7093 @cindex module closure
7094 @findex source-module-closure
7095 Usually you want the @emph{closure} of the module to be imported---i.e.,
7096 the module itself and all the modules it depends on---rather than just
7097 the module; failing to do that, attempts to use the module will fail
7098 because of missing dependent modules. The @code{source-module-closure}
7099 procedure computes the closure of a module by looking at its source file
7100 headers, which comes in handy in this case:
7103 (use-modules (guix modules)) ;for 'source-module-closure'
7105 (with-imported-modules (source-module-closure
7106 '((guix build utils)
7108 (gexp->derivation "something-with-vms"
7110 (use-modules (guix build utils)
7115 @cindex extensions, for gexps
7116 @findex with-extensions
7117 In the same vein, sometimes you want to import not just pure-Scheme
7118 modules, but also ``extensions'' such as Guile bindings to C libraries
7119 or other ``full-blown'' packages. Say you need the @code{guile-json}
7120 package available on the build side, here's how you would do it:
7123 (use-modules (gnu packages guile)) ;for 'guile-json'
7125 (with-extensions (list guile-json)
7126 (gexp->derivation "something-with-json"
7128 (use-modules (json))
7132 The syntactic form to construct gexps is summarized below.
7134 @deffn {Scheme Syntax} #~@var{exp}
7135 @deffnx {Scheme Syntax} (gexp @var{exp})
7136 Return a G-expression containing @var{exp}. @var{exp} may contain one
7137 or more of the following forms:
7141 @itemx (ungexp @var{obj})
7142 Introduce a reference to @var{obj}. @var{obj} may have one of the
7143 supported types, for example a package or a
7144 derivation, in which case the @code{ungexp} form is replaced by its
7145 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7147 If @var{obj} is a list, it is traversed and references to supported
7148 objects are substituted similarly.
7150 If @var{obj} is another gexp, its contents are inserted and its
7151 dependencies are added to those of the containing gexp.
7153 If @var{obj} is another kind of object, it is inserted as is.
7155 @item #$@var{obj}:@var{output}
7156 @itemx (ungexp @var{obj} @var{output})
7157 This is like the form above, but referring explicitly to the
7158 @var{output} of @var{obj}---this is useful when @var{obj} produces
7159 multiple outputs (@pxref{Packages with Multiple Outputs}).
7162 @itemx #+@var{obj}:output
7163 @itemx (ungexp-native @var{obj})
7164 @itemx (ungexp-native @var{obj} @var{output})
7165 Same as @code{ungexp}, but produces a reference to the @emph{native}
7166 build of @var{obj} when used in a cross compilation context.
7168 @item #$output[:@var{output}]
7169 @itemx (ungexp output [@var{output}])
7170 Insert a reference to derivation output @var{output}, or to the main
7171 output when @var{output} is omitted.
7173 This only makes sense for gexps passed to @code{gexp->derivation}.
7176 @itemx (ungexp-splicing @var{lst})
7177 Like the above, but splices the contents of @var{lst} inside the
7181 @itemx (ungexp-native-splicing @var{lst})
7182 Like the above, but refers to native builds of the objects listed in
7187 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7188 of the @code{gexp?} type (see below.)
7191 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7192 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7193 in their execution environment.
7195 Each item in @var{modules} can be the name of a module, such as
7196 @code{(guix build utils)}, or it can be a module name, followed by an
7197 arrow, followed by a file-like object:
7200 `((guix build utils)
7202 ((guix config) => ,(scheme-file "config.scm"
7203 #~(define-module @dots{}))))
7207 In the example above, the first two modules are taken from the search
7208 path, and the last one is created from the given file-like object.
7210 This form has @emph{lexical} scope: it has an effect on the gexps
7211 directly defined in @var{body}@dots{}, but not on those defined, say, in
7212 procedures called from @var{body}@dots{}.
7215 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7216 Mark the gexps defined in @var{body}@dots{} as requiring
7217 @var{extensions} in their build and execution environment.
7218 @var{extensions} is typically a list of package objects such as those
7219 defined in the @code{(gnu packages guile)} module.
7221 Concretely, the packages listed in @var{extensions} are added to the
7222 load path while compiling imported modules in @var{body}@dots{}; they
7223 are also added to the load path of the gexp returned by
7227 @deffn {Scheme Procedure} gexp? @var{obj}
7228 Return @code{#t} if @var{obj} is a G-expression.
7231 G-expressions are meant to be written to disk, either as code building
7232 some derivation, or as plain files in the store. The monadic procedures
7233 below allow you to do that (@pxref{The Store Monad}, for more
7234 information about monads.)
7236 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7237 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7238 [#:hash #f] [#:hash-algo #f] @
7239 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7240 [#:module-path @var{%load-path}] @
7241 [#:effective-version "2.2"] @
7242 [#:references-graphs #f] [#:allowed-references #f] @
7243 [#:disallowed-references #f] @
7244 [#:leaked-env-vars #f] @
7245 [#:script-name (string-append @var{name} "-builder")] @
7246 [#:deprecation-warnings #f] @
7247 [#:local-build? #f] [#:substitutable? #t] @
7248 [#:properties '()] [#:guile-for-build #f]
7249 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7250 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7251 stored in a file called @var{script-name}. When @var{target} is true,
7252 it is used as the cross-compilation target triplet for packages referred
7255 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7257 make @var{modules} available in the evaluation context of @var{exp};
7258 @var{modules} is a list of names of Guile modules searched in
7259 @var{module-path} to be copied in the store, compiled, and made available in
7260 the load path during the execution of @var{exp}---e.g., @code{((guix
7261 build utils) (guix build gnu-build-system))}.
7263 @var{effective-version} determines the string to use when adding extensions of
7264 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7266 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7269 When @var{references-graphs} is true, it must be a list of tuples of one of the
7273 (@var{file-name} @var{package})
7274 (@var{file-name} @var{package} @var{output})
7275 (@var{file-name} @var{derivation})
7276 (@var{file-name} @var{derivation} @var{output})
7277 (@var{file-name} @var{store-item})
7280 The right-hand-side of each element of @var{references-graphs} is automatically made
7281 an input of the build process of @var{exp}. In the build environment, each
7282 @var{file-name} contains the reference graph of the corresponding item, in a simple
7285 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7286 In the latter case, the list denotes store items that the result is allowed to
7287 refer to. Any reference to another store item will lead to a build error.
7288 Similarly for @var{disallowed-references}, which can list items that must not be
7289 referenced by the outputs.
7291 @var{deprecation-warnings} determines whether to show deprecation warnings while
7292 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7294 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7297 @cindex file-like objects
7298 The @code{local-file}, @code{plain-file}, @code{computed-file},
7299 @code{program-file}, and @code{scheme-file} procedures below return
7300 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7301 these objects lead to a file in the store. Consider this G-expression:
7304 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7305 #$(local-file "/tmp/my-nscd.conf"))
7308 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7309 to the store. Once expanded, for instance @i{via}
7310 @code{gexp->derivation}, the G-expression refers to that copy under
7311 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7312 does not have any effect on what the G-expression does.
7313 @code{plain-file} can be used similarly; it differs in that the file
7314 content is directly passed as a string.
7316 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7317 [#:recursive? #f] [#:select? (const #t)]
7318 Return an object representing local file @var{file} to add to the store; this
7319 object can be used in a gexp. If @var{file} is a relative file name, it is looked
7320 up relative to the source file where this form appears. @var{file} will be added to
7321 the store under @var{name}--by default the base name of @var{file}.
7323 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7324 designates a flat file and @var{recursive?} is true, its contents are added, and its
7325 permission bits are kept.
7327 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7328 @var{stat})} for each directory entry, where @var{file} is the entry's
7329 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7330 entries for which @var{select?} does not return true.
7332 This is the declarative counterpart of the @code{interned-file} monadic
7333 procedure (@pxref{The Store Monad, @code{interned-file}}).
7336 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7337 Return an object representing a text file called @var{name} with the given
7338 @var{content} (a string or a bytevector) to be added to the store.
7340 This is the declarative counterpart of @code{text-file}.
7343 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7344 [#:options '(#:local-build? #t)]
7345 Return an object representing the store item @var{name}, a file or
7346 directory computed by @var{gexp}. @var{options}
7347 is a list of additional arguments to pass to @code{gexp->derivation}.
7349 This is the declarative counterpart of @code{gexp->derivation}.
7352 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7353 [#:guile (default-guile)] [#:module-path %load-path]
7354 Return an executable script @var{name} that runs @var{exp} using
7355 @var{guile}, with @var{exp}'s imported modules in its search path.
7356 Look up @var{exp}'s modules in @var{module-path}.
7358 The example below builds a script that simply invokes the @command{ls}
7362 (use-modules (guix gexp) (gnu packages base))
7364 (gexp->script "list-files"
7365 #~(execl #$(file-append coreutils "/bin/ls")
7369 When ``running'' it through the store (@pxref{The Store Monad,
7370 @code{run-with-store}}), we obtain a derivation that produces an
7371 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7374 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7376 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7380 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7381 [#:guile #f] [#:module-path %load-path]
7382 Return an object representing the executable store item @var{name} that
7383 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7384 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7386 This is the declarative counterpart of @code{gexp->script}.
7389 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7390 [#:set-load-path? #t] [#:module-path %load-path] @
7392 [#:guile (default-guile)]
7393 Return a derivation that builds a file @var{name} containing @var{exp}.
7394 When @var{splice?} is true, @var{exp} is considered to be a list of
7395 expressions that will be spliced in the resulting file.
7397 When @var{set-load-path?} is true, emit code in the resulting file to
7398 set @code{%load-path} and @code{%load-compiled-path} to honor
7399 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7402 The resulting file holds references to all the dependencies of @var{exp}
7403 or a subset thereof.
7406 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
7407 Return an object representing the Scheme file @var{name} that contains
7410 This is the declarative counterpart of @code{gexp->file}.
7413 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7414 Return as a monadic value a derivation that builds a text file
7415 containing all of @var{text}. @var{text} may list, in addition to
7416 strings, objects of any type that can be used in a gexp: packages,
7417 derivations, local file objects, etc. The resulting store file holds
7418 references to all these.
7420 This variant should be preferred over @code{text-file} anytime the file
7421 to create will reference items from the store. This is typically the
7422 case when building a configuration file that embeds store file names,
7426 (define (profile.sh)
7427 ;; Return the name of a shell script in the store that
7428 ;; initializes the 'PATH' environment variable.
7429 (text-file* "profile.sh"
7430 "export PATH=" coreutils "/bin:"
7431 grep "/bin:" sed "/bin\n"))
7434 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
7435 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
7436 preventing them from being garbage-collected during its lifetime.
7439 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
7440 Return an object representing store file @var{name} containing
7441 @var{text}. @var{text} is a sequence of strings and file-like objects,
7445 (mixed-text-file "profile"
7446 "export PATH=" coreutils "/bin:" grep "/bin")
7449 This is the declarative counterpart of @code{text-file*}.
7452 @deffn {Scheme Procedure} file-union @var{name} @var{files}
7453 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
7454 Each item in @var{files} must be a two-element list where the first element is the
7455 file name to use in the new directory, and the second element is a gexp
7456 denoting the target file. Here's an example:
7460 `(("hosts" ,(plain-file "hosts"
7461 "127.0.0.1 localhost"))
7462 ("bashrc" ,(plain-file "bashrc"
7463 "alias ls='ls --color=auto'"))))
7466 This yields an @code{etc} directory containing these two files.
7469 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
7470 Return a directory that is the union of @var{things}, where @var{things} is a list of
7471 file-like objects denoting directories. For example:
7474 (directory-union "guile+emacs" (list guile emacs))
7477 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
7480 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
7481 Return a file-like object that expands to the concatenation of @var{obj}
7482 and @var{suffix}, where @var{obj} is a lowerable object and each
7483 @var{suffix} is a string.
7485 As an example, consider this gexp:
7488 (gexp->script "run-uname"
7489 #~(system* #$(file-append coreutils
7493 The same effect could be achieved with:
7496 (gexp->script "run-uname"
7497 #~(system* (string-append #$coreutils
7501 There is one difference though: in the @code{file-append} case, the
7502 resulting script contains the absolute file name as a string, whereas in
7503 the second case, the resulting script contains a @code{(string-append
7504 @dots{})} expression to construct the file name @emph{at run time}.
7508 Of course, in addition to gexps embedded in ``host'' code, there are
7509 also modules containing build tools. To make it clear that they are
7510 meant to be used in the build stratum, these modules are kept in the
7511 @code{(guix build @dots{})} name space.
7513 @cindex lowering, of high-level objects in gexps
7514 Internally, high-level objects are @dfn{lowered}, using their compiler,
7515 to either derivations or store items. For instance, lowering a package
7516 yields a derivation, and lowering a @code{plain-file} yields a store
7517 item. This is achieved using the @code{lower-object} monadic procedure.
7519 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
7521 Return as a value in @var{%store-monad} the derivation or store item
7522 corresponding to @var{obj} for @var{system}, cross-compiling for
7523 @var{target} if @var{target} is true. @var{obj} must be an object that
7524 has an associated gexp compiler, such as a @code{<package>}.
7527 @node Invoking guix repl
7528 @section Invoking @command{guix repl}
7530 @cindex REPL, read-eval-print loop
7531 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
7532 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
7533 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
7534 command, @command{guix repl} guarantees that all the Guix modules and all its
7535 dependencies are available in the search path. You can use it this way:
7539 scheme@@(guile-user)> ,use (gnu packages base)
7540 scheme@@(guile-user)> coreutils
7541 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
7545 In addition, @command{guix repl} implements a simple machine-readable REPL
7546 protocol for use by @code{(guix inferior)}, a facility to interact with
7547 @dfn{inferiors}, separate processes running a potentially different revision
7550 The available options are as follows:
7553 @item --type=@var{type}
7554 @itemx -t @var{type}
7555 Start a REPL of the given @var{TYPE}, which can be one of the following:
7559 This is default, and it spawns a standard full-featured Guile REPL.
7561 Spawn a REPL that uses the machine-readable protocol. This is the protocol
7562 that the @code{(guix inferior)} module speaks.
7565 @item --listen=@var{endpoint}
7566 By default, @command{guix repl} reads from standard input and writes to
7567 standard output. When this option is passed, it will instead listen for
7568 connections on @var{endpoint}. Here are examples of valid options:
7571 @item --listen=tcp:37146
7572 Accept connections on localhost on port 37146.
7574 @item --listen=unix:/tmp/socket
7575 Accept connections on the Unix-domain socket @file{/tmp/socket}.
7579 @c *********************************************************************
7583 This section describes Guix command-line utilities. Some of them are
7584 primarily targeted at developers and users who write new package
7585 definitions, while others are more generally useful. They complement
7586 the Scheme programming interface of Guix in a convenient way.
7589 * Invoking guix build:: Building packages from the command line.
7590 * Invoking guix edit:: Editing package definitions.
7591 * Invoking guix download:: Downloading a file and printing its hash.
7592 * Invoking guix hash:: Computing the cryptographic hash of a file.
7593 * Invoking guix import:: Importing package definitions.
7594 * Invoking guix refresh:: Updating package definitions.
7595 * Invoking guix lint:: Finding errors in package definitions.
7596 * Invoking guix size:: Profiling disk usage.
7597 * Invoking guix graph:: Visualizing the graph of packages.
7598 * Invoking guix publish:: Sharing substitutes.
7599 * Invoking guix challenge:: Challenging substitute servers.
7600 * Invoking guix copy:: Copying to and from a remote store.
7601 * Invoking guix container:: Process isolation.
7602 * Invoking guix weather:: Assessing substitute availability.
7603 * Invoking guix processes:: Listing client processes.
7606 @node Invoking guix build
7607 @section Invoking @command{guix build}
7609 @cindex package building
7610 @cindex @command{guix build}
7611 The @command{guix build} command builds packages or derivations and
7612 their dependencies, and prints the resulting store paths. Note that it
7613 does not modify the user's profile---this is the job of the
7614 @command{guix package} command (@pxref{Invoking guix package}). Thus,
7615 it is mainly useful for distribution developers.
7617 The general syntax is:
7620 guix build @var{options} @var{package-or-derivation}@dots{}
7623 As an example, the following command builds the latest versions of Emacs
7624 and of Guile, displays their build logs, and finally displays the
7625 resulting directories:
7628 guix build emacs guile
7631 Similarly, the following command builds all the available packages:
7634 guix build --quiet --keep-going \
7635 `guix package -A | cut -f1,2 --output-delimiter=@@`
7638 @var{package-or-derivation} may be either the name of a package found in
7639 the software distribution such as @code{coreutils} or
7640 @code{coreutils@@8.20}, or a derivation such as
7641 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
7642 package with the corresponding name (and optionally version) is searched
7643 for among the GNU distribution modules (@pxref{Package Modules}).
7645 Alternatively, the @code{--expression} option may be used to specify a
7646 Scheme expression that evaluates to a package; this is useful when
7647 disambiguating among several same-named packages or package variants is
7650 There may be zero or more @var{options}. The available options are
7651 described in the subsections below.
7654 * Common Build Options:: Build options for most commands.
7655 * Package Transformation Options:: Creating variants of packages.
7656 * Additional Build Options:: Options specific to 'guix build'.
7657 * Debugging Build Failures:: Real life packaging experience.
7660 @node Common Build Options
7661 @subsection Common Build Options
7663 A number of options that control the build process are common to
7664 @command{guix build} and other commands that can spawn builds, such as
7665 @command{guix package} or @command{guix archive}. These are the
7670 @item --load-path=@var{directory}
7671 @itemx -L @var{directory}
7672 Add @var{directory} to the front of the package module search path
7673 (@pxref{Package Modules}).
7675 This allows users to define their own packages and make them visible to
7676 the command-line tools.
7680 Keep the build tree of failed builds. Thus, if a build fails, its build
7681 tree is kept under @file{/tmp}, in a directory whose name is shown at
7682 the end of the build log. This is useful when debugging build issues.
7683 @xref{Debugging Build Failures}, for tips and tricks on how to debug
7686 This option has no effect when connecting to a remote daemon with a
7687 @code{guix://} URI (@pxref{The Store, the @code{GUIX_DAEMON_SOCKET}
7692 Keep going when some of the derivations fail to build; return only once
7693 all the builds have either completed or failed.
7695 The default behavior is to stop as soon as one of the specified
7696 derivations has failed.
7700 Do not build the derivations.
7702 @anchor{fallback-option}
7704 When substituting a pre-built binary fails, fall back to building
7705 packages locally (@pxref{Substitution Failure}).
7707 @item --substitute-urls=@var{urls}
7708 @anchor{client-substitute-urls}
7709 Consider @var{urls} the whitespace-separated list of substitute source
7710 URLs, overriding the default list of URLs of @command{guix-daemon}
7711 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
7713 This means that substitutes may be downloaded from @var{urls}, provided
7714 they are signed by a key authorized by the system administrator
7715 (@pxref{Substitutes}).
7717 When @var{urls} is the empty string, substitutes are effectively
7720 @item --no-substitutes
7721 Do not use substitutes for build products. That is, always build things
7722 locally instead of allowing downloads of pre-built binaries
7723 (@pxref{Substitutes}).
7726 Do not ``graft'' packages. In practice, this means that package updates
7727 available as grafts are not applied. @xref{Security Updates}, for more
7728 information on grafts.
7730 @item --rounds=@var{n}
7731 Build each derivation @var{n} times in a row, and raise an error if
7732 consecutive build results are not bit-for-bit identical.
7734 This is a useful way to detect non-deterministic builds processes.
7735 Non-deterministic build processes are a problem because they make it
7736 practically impossible for users to @emph{verify} whether third-party
7737 binaries are genuine. @xref{Invoking guix challenge}, for more.
7739 Note that, currently, the differing build results are not kept around,
7740 so you will have to manually investigate in case of an error---e.g., by
7741 stashing one of the build results with @code{guix archive --export}
7742 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
7745 @item --no-build-hook
7746 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
7747 (@pxref{Daemon Offload Setup}). That is, always build things locally
7748 instead of offloading builds to remote machines.
7750 @item --max-silent-time=@var{seconds}
7751 When the build or substitution process remains silent for more than
7752 @var{seconds}, terminate it and report a build failure.
7754 By default, the daemon's setting is honored (@pxref{Invoking
7755 guix-daemon, @code{--max-silent-time}}).
7757 @item --timeout=@var{seconds}
7758 Likewise, when the build or substitution process lasts for more than
7759 @var{seconds}, terminate it and report a build failure.
7761 By default, the daemon's setting is honored (@pxref{Invoking
7762 guix-daemon, @code{--timeout}}).
7764 @c Note: This option is actually not part of %standard-build-options but
7765 @c most programs honor it.
7766 @cindex verbosity, of the command-line tools
7767 @cindex build logs, verbosity
7768 @item -v @var{level}
7769 @itemx --verbosity=@var{level}
7770 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
7771 output is produced, 1 is for quiet output, and 2 shows all the build log
7772 output on standard error.
7774 @item --cores=@var{n}
7776 Allow the use of up to @var{n} CPU cores for the build. The special
7777 value @code{0} means to use as many CPU cores as available.
7779 @item --max-jobs=@var{n}
7781 Allow at most @var{n} build jobs in parallel. @xref{Invoking
7782 guix-daemon, @code{--max-jobs}}, for details about this option and the
7783 equivalent @command{guix-daemon} option.
7785 @item --debug=@var{level}
7786 Produce debugging output coming from the build daemon. @var{level} must be an
7787 integer between 0 and 5; higher means more verbose output. Setting a level of
7788 4 or more may be helpful when debugging setup issues with the build daemon.
7792 Behind the scenes, @command{guix build} is essentially an interface to
7793 the @code{package-derivation} procedure of the @code{(guix packages)}
7794 module, and to the @code{build-derivations} procedure of the @code{(guix
7795 derivations)} module.
7797 In addition to options explicitly passed on the command line,
7798 @command{guix build} and other @command{guix} commands that support
7799 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
7801 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
7802 Users can define this variable to a list of command line options that
7803 will automatically be used by @command{guix build} and other
7804 @command{guix} commands that can perform builds, as in the example
7808 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
7811 These options are parsed independently, and the result is appended to
7812 the parsed command-line options.
7816 @node Package Transformation Options
7817 @subsection Package Transformation Options
7819 @cindex package variants
7820 Another set of command-line options supported by @command{guix build}
7821 and also @command{guix package} are @dfn{package transformation
7822 options}. These are options that make it possible to define @dfn{package
7823 variants}---for instance, packages built from different source code.
7824 This is a convenient way to create customized packages on the fly
7825 without having to type in the definitions of package variants
7826 (@pxref{Defining Packages}).
7830 @item --with-source=@var{source}
7831 @itemx --with-source=@var{package}=@var{source}
7832 @itemx --with-source=@var{package}@@@var{version}=@var{source}
7833 Use @var{source} as the source of @var{package}, and @var{version} as
7835 @var{source} must be a file name or a URL, as for @command{guix
7836 download} (@pxref{Invoking guix download}).
7838 When @var{package} is omitted,
7839 it is taken to be the package name specified on the
7840 command line that matches the base of @var{source}---e.g.,
7841 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
7842 package is @code{guile}.
7844 Likewise, when @var{version} is omitted, the version string is inferred from
7845 @var{source}; in the previous example, it is @code{2.0.10}.
7847 This option allows users to try out versions of packages other than the
7848 one provided by the distribution. The example below downloads
7849 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
7850 the @code{ed} package:
7853 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
7856 As a developer, @code{--with-source} makes it easy to test release
7860 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
7863 @dots{} or to build from a checkout in a pristine environment:
7866 $ git clone git://git.sv.gnu.org/guix.git
7867 $ guix build guix --with-source=guix@@1.0=./guix
7870 @item --with-input=@var{package}=@var{replacement}
7871 Replace dependency on @var{package} by a dependency on
7872 @var{replacement}. @var{package} must be a package name, and
7873 @var{replacement} must be a package specification such as @code{guile}
7874 or @code{guile@@1.8}.
7876 For instance, the following command builds Guix, but replaces its
7877 dependency on the current stable version of Guile with a dependency on
7878 the legacy version of Guile, @code{guile@@2.0}:
7881 guix build --with-input=guile=guile@@2.0 guix
7884 This is a recursive, deep replacement. So in this example, both
7885 @code{guix} and its dependency @code{guile-json} (which also depends on
7886 @code{guile}) get rebuilt against @code{guile@@2.0}.
7888 This is implemented using the @code{package-input-rewriting} Scheme
7889 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
7891 @item --with-graft=@var{package}=@var{replacement}
7892 This is similar to @code{--with-input} but with an important difference:
7893 instead of rebuilding the whole dependency chain, @var{replacement} is
7894 built and then @dfn{grafted} onto the binaries that were initially
7895 referring to @var{package}. @xref{Security Updates}, for more
7896 information on grafts.
7898 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
7899 and all its dependencies, replacing references to the version of GnuTLS
7900 they currently refer to:
7903 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
7906 This has the advantage of being much faster than rebuilding everything.
7907 But there is a caveat: it works if and only if @var{package} and
7908 @var{replacement} are strictly compatible---for example, if they provide
7909 a library, the application binary interface (ABI) of those libraries
7910 must be compatible. If @var{replacement} is somehow incompatible with
7911 @var{package}, then the resulting package may be unusable. Use with
7914 @item --with-git-url=@var{package}=@var{url}
7915 @cindex Git, using the latest commit
7916 @cindex latest commit, building
7917 Build @var{package} from the latest commit of the @code{master} branch of the
7918 Git repository at @var{url}. Git sub-modules of the repository are fetched,
7921 For example, the following command builds the NumPy Python library against the
7922 latest commit of the master branch of Python itself:
7925 guix build python-numpy \
7926 --with-git-url=python=https://github.com/python/cpython
7929 This option can also be combined with @code{--with-branch} or
7930 @code{--with-commit} (see below).
7932 @cindex continuous integration
7933 Obviously, since it uses the latest commit of the given branch, the result of
7934 such a command varies over time. Nevertheless it is a convenient way to
7935 rebuild entire software stacks against the latest commit of one or more
7936 packages. This is particularly useful in the context of continuous
7939 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
7940 consecutive accesses to the same repository. You may want to clean it up once
7941 in a while to save disk space.
7943 @item --with-branch=@var{package}=@var{branch}
7944 Build @var{package} from the latest commit of @var{branch}. If the
7945 @code{source} field of @var{package} is an origin with the @code{git-fetch}
7946 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
7947 repository URL is taken from that @code{source}. Otherwise you have to use
7948 @code{--with-git-url} to specify the URL of the Git repository.
7950 For instance, the following command builds @code{guile-sqlite3} from the
7951 latest commit of its @code{master} branch, and then builds @code{guix} (which
7952 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
7953 specific @code{guile-sqlite3} build:
7956 guix build --with-branch=guile-sqlite3=master cuirass
7959 @item --with-commit=@var{package}=@var{commit}
7960 This is similar to @code{--with-branch}, except that it builds from
7961 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
7962 Git commit SHA1 identifier.
7965 @node Additional Build Options
7966 @subsection Additional Build Options
7968 The command-line options presented below are specific to @command{guix
7975 Build quietly, without displaying the build log; this is equivalent to
7976 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
7977 (or similar) and can always be retrieved using the @option{--log-file} option.
7979 @item --file=@var{file}
7980 @itemx -f @var{file}
7981 Build the package, derivation, or other file-like object that the code within
7982 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
7984 As an example, @var{file} might contain a package definition like this
7985 (@pxref{Defining Packages}):
7988 @verbatiminclude package-hello.scm
7991 @item --expression=@var{expr}
7992 @itemx -e @var{expr}
7993 Build the package or derivation @var{expr} evaluates to.
7995 For example, @var{expr} may be @code{(@@ (gnu packages guile)
7996 guile-1.8)}, which unambiguously designates this specific variant of
7997 version 1.8 of Guile.
7999 Alternatively, @var{expr} may be a G-expression, in which case it is used
8000 as a build program passed to @code{gexp->derivation}
8001 (@pxref{G-Expressions}).
8003 Lastly, @var{expr} may refer to a zero-argument monadic procedure
8004 (@pxref{The Store Monad}). The procedure must return a derivation as a
8005 monadic value, which is then passed through @code{run-with-store}.
8009 Build the source derivations of the packages, rather than the packages
8012 For instance, @code{guix build -S gcc} returns something like
8013 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
8016 The returned source tarball is the result of applying any patches and
8017 code snippets specified in the package @code{origin} (@pxref{Defining
8021 Fetch and return the source of @var{package-or-derivation} and all their
8022 dependencies, recursively. This is a handy way to obtain a local copy
8023 of all the source code needed to build @var{packages}, allowing you to
8024 eventually build them even without network access. It is an extension
8025 of the @code{--source} option and can accept one of the following
8026 optional argument values:
8030 This value causes the @code{--sources} option to behave in the same way
8031 as the @code{--source} option.
8034 Build the source derivations of all packages, including any source that
8035 might be listed as @code{inputs}. This is the default value.
8038 $ guix build --sources tzdata
8039 The following derivations will be built:
8040 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
8041 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8045 Build the source derivations of all packages, as well of all transitive
8046 inputs to the packages. This can be used e.g.@: to
8047 prefetch package source for later offline building.
8050 $ guix build --sources=transitive tzdata
8051 The following derivations will be built:
8052 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8053 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
8054 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
8055 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
8056 /gnu/store/@dots{}-make-4.1.tar.xz.drv
8057 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
8063 @item --system=@var{system}
8064 @itemx -s @var{system}
8065 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
8066 the system type of the build host. The @command{guix build} command allows
8067 you to repeat this option several times, in which case it builds for all the
8068 specified systems; other commands ignore extraneous @option{-s} options.
8071 The @code{--system} flag is for @emph{native} compilation and must not
8072 be confused with cross-compilation. See @code{--target} below for
8073 information on cross-compilation.
8076 An example use of this is on Linux-based systems, which can emulate
8077 different personalities. For instance, passing
8078 @code{--system=i686-linux} on an @code{x86_64-linux} system or
8079 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
8080 to build packages in a complete 32-bit environment.
8083 Building for an @code{armhf-linux} system is unconditionally enabled on
8084 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8085 allow for this functionality, notably the ThunderX.
8088 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8089 is enabled (@pxref{Virtualization Services,
8090 @code{qemu-binfmt-service-type}}), you can build for any system for
8091 which a QEMU @code{binfmt_misc} handler is installed.
8093 Builds for a system other than that of the machine you are using can
8094 also be offloaded to a remote machine of the right architecture.
8095 @xref{Daemon Offload Setup}, for more information on offloading.
8097 @item --target=@var{triplet}
8098 @cindex cross-compilation
8099 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8100 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
8101 configuration triplets,, autoconf, Autoconf}).
8103 @anchor{build-check}
8105 @cindex determinism, checking
8106 @cindex reproducibility, checking
8107 Rebuild @var{package-or-derivation}, which are already available in the
8108 store, and raise an error if the build results are not bit-for-bit
8111 This mechanism allows you to check whether previously installed
8112 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8113 of a package is deterministic. @xref{Invoking guix challenge}, for more
8114 background information and tools.
8116 When used in conjunction with @option{--keep-failed}, the differing
8117 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8118 This makes it easy to look for differences between the two results.
8121 @cindex repairing store items
8122 @cindex corruption, recovering from
8123 Attempt to repair the specified store items, if they are corrupt, by
8124 re-downloading or rebuilding them.
8126 This operation is not atomic and thus restricted to @code{root}.
8130 Return the derivation paths, not the output paths, of the given
8133 @item --root=@var{file}
8134 @itemx -r @var{file}
8135 @cindex GC roots, adding
8136 @cindex garbage collector roots, adding
8137 Make @var{file} a symlink to the result, and register it as a garbage
8140 Consequently, the results of this @command{guix build} invocation are
8141 protected from garbage collection until @var{file} is removed. When
8142 that option is omitted, build results are eligible for garbage
8143 collection as soon as the build completes. @xref{Invoking guix gc}, for
8147 @cindex build logs, access
8148 Return the build log file names or URLs for the given
8149 @var{package-or-derivation}, or raise an error if build logs are
8152 This works regardless of how packages or derivations are specified. For
8153 instance, the following invocations are equivalent:
8156 guix build --log-file `guix build -d guile`
8157 guix build --log-file `guix build guile`
8158 guix build --log-file guile
8159 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8162 If a log is unavailable locally, and unless @code{--no-substitutes} is
8163 passed, the command looks for a corresponding log on one of the
8164 substitute servers (as specified with @code{--substitute-urls}.)
8166 So for instance, imagine you want to see the build log of GDB on MIPS,
8167 but you are actually on an @code{x86_64} machine:
8170 $ guix build --log-file gdb -s mips64el-linux
8171 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8174 You can freely access a huge library of build logs!
8177 @node Debugging Build Failures
8178 @subsection Debugging Build Failures
8180 @cindex build failures, debugging
8181 When defining a new package (@pxref{Defining Packages}), you will
8182 probably find yourself spending some time debugging and tweaking the
8183 build until it succeeds. To do that, you need to operate the build
8184 commands yourself in an environment as close as possible to the one the
8187 To that end, the first thing to do is to use the @option{--keep-failed}
8188 or @option{-K} option of @command{guix build}, which will keep the
8189 failed build tree in @file{/tmp} or whatever directory you specified as
8190 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8192 From there on, you can @command{cd} to the failed build tree and source
8193 the @file{environment-variables} file, which contains all the
8194 environment variable definitions that were in place when the build
8195 failed. So let's say you're debugging a build failure in package
8196 @code{foo}; a typical session would look like this:
8200 @dots{} @i{build fails}
8201 $ cd /tmp/guix-build-foo.drv-0
8202 $ source ./environment-variables
8206 Now, you can invoke commands as if you were the daemon (almost) and
8207 troubleshoot your build process.
8209 Sometimes it happens that, for example, a package's tests pass when you
8210 run them manually but they fail when the daemon runs them. This can
8211 happen because the daemon runs builds in containers where, unlike in our
8212 environment above, network access is missing, @file{/bin/sh} does not
8213 exist, etc. (@pxref{Build Environment Setup}).
8215 In such cases, you may need to run inspect the build process from within
8216 a container similar to the one the build daemon creates:
8221 $ cd /tmp/guix-build-foo.drv-0
8222 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8223 [env]# source ./environment-variables
8227 Here, @command{guix environment -C} creates a container and spawns a new
8228 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8229 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8230 the container, which would may find handy while debugging. The
8231 @option{--no-grafts} option makes sure we get the exact same
8232 environment, with ungrafted packages (@pxref{Security Updates}, for more
8235 To get closer to a container like that used by the build daemon, we can
8236 remove @file{/bin/sh}:
8242 (Don't worry, this is harmless: this is all happening in the throw-away
8243 container created by @command{guix environment}.)
8245 The @command{strace} command is probably not in the search path, but we
8249 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8252 In this way, not only you will have reproduced the environment variables
8253 the daemon uses, you will also be running the build process in a container
8254 similar to the one the daemon uses.
8257 @node Invoking guix edit
8258 @section Invoking @command{guix edit}
8260 @cindex @command{guix edit}
8261 @cindex package definition, editing
8262 So many packages, so many source files! The @command{guix edit} command
8263 facilitates the life of users and packagers by pointing their editor at
8264 the source file containing the definition of the specified packages.
8268 guix edit gcc@@4.9 vim
8272 launches the program specified in the @code{VISUAL} or in the
8273 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8276 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8277 have created your own packages on @code{GUIX_PACKAGE_PATH}
8278 (@pxref{Package Modules}), you will be able to edit the package
8279 recipes. In other cases, you will be able to examine the read-only recipes
8280 for packages currently in the store.
8283 @node Invoking guix download
8284 @section Invoking @command{guix download}
8286 @cindex @command{guix download}
8287 @cindex downloading package sources
8288 When writing a package definition, developers typically need to download
8289 a source tarball, compute its SHA256 hash, and write that
8290 hash in the package definition (@pxref{Defining Packages}). The
8291 @command{guix download} tool helps with this task: it downloads a file
8292 from the given URI, adds it to the store, and prints both its file name
8293 in the store and its SHA256 hash.
8295 The fact that the downloaded file is added to the store saves bandwidth:
8296 when the developer eventually tries to build the newly defined package
8297 with @command{guix build}, the source tarball will not have to be
8298 downloaded again because it is already in the store. It is also a
8299 convenient way to temporarily stash files, which may be deleted
8300 eventually (@pxref{Invoking guix gc}).
8302 The @command{guix download} command supports the same URIs as used in
8303 package definitions. In particular, it supports @code{mirror://} URIs.
8304 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8305 Guile bindings for GnuTLS are available in the user's environment; when
8306 they are not available, an error is raised. @xref{Guile Preparations,
8307 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8308 GnuTLS-Guile}, for more information.
8310 @command{guix download} verifies HTTPS server certificates by loading
8311 the certificates of X.509 authorities from the directory pointed to by
8312 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8313 Certificates}), unless @option{--no-check-certificate} is used.
8315 The following options are available:
8318 @item --format=@var{fmt}
8320 Write the hash in the format specified by @var{fmt}. For more
8321 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8323 @item --no-check-certificate
8324 Do not validate the X.509 certificates of HTTPS servers.
8326 When using this option, you have @emph{absolutely no guarantee} that you
8327 are communicating with the authentic server responsible for the given
8328 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8330 @item --output=@var{file}
8331 @itemx -o @var{file}
8332 Save the downloaded file to @var{file} instead of adding it to the
8336 @node Invoking guix hash
8337 @section Invoking @command{guix hash}
8339 @cindex @command{guix hash}
8340 The @command{guix hash} command computes the SHA256 hash of a file.
8341 It is primarily a convenience tool for anyone contributing to the
8342 distribution: it computes the cryptographic hash of a file, which can be
8343 used in the definition of a package (@pxref{Defining Packages}).
8345 The general syntax is:
8348 guix hash @var{option} @var{file}
8351 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8352 hash of data read from standard input. @command{guix hash} has the
8357 @item --format=@var{fmt}
8359 Write the hash in the format specified by @var{fmt}.
8361 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8362 (@code{hex} and @code{hexadecimal} can be used as well).
8364 If the @option{--format} option is not specified, @command{guix hash}
8365 will output the hash in @code{nix-base32}. This representation is used
8366 in the definitions of packages.
8370 Compute the hash on @var{file} recursively.
8372 In this case, the hash is computed on an archive containing @var{file},
8373 including its children if it is a directory. Some of the metadata of
8374 @var{file} is part of the archive; for instance, when @var{file} is a
8375 regular file, the hash is different depending on whether @var{file} is
8376 executable or not. Metadata such as time stamps has no impact on the
8377 hash (@pxref{Invoking guix archive}).
8378 @c FIXME: Replace xref above with xref to an ``Archive'' section when
8383 When combined with @option{--recursive}, exclude version control system
8384 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
8387 As an example, here is how you would compute the hash of a Git checkout,
8388 which is useful when using the @code{git-fetch} method (@pxref{origin
8392 $ git clone http://example.org/foo.git
8398 @node Invoking guix import
8399 @section Invoking @command{guix import}
8401 @cindex importing packages
8402 @cindex package import
8403 @cindex package conversion
8404 @cindex Invoking @command{guix import}
8405 The @command{guix import} command is useful for people who would like to
8406 add a package to the distribution with as little work as
8407 possible---a legitimate demand. The command knows of a few
8408 repositories from which it can ``import'' package metadata. The result
8409 is a package definition, or a template thereof, in the format we know
8410 (@pxref{Defining Packages}).
8412 The general syntax is:
8415 guix import @var{importer} @var{options}@dots{}
8418 @var{importer} specifies the source from which to import package
8419 metadata, and @var{options} specifies a package identifier and other
8420 options specific to @var{importer}. Currently, the available
8425 Import metadata for the given GNU package. This provides a template
8426 for the latest version of that GNU package, including the hash of its
8427 source tarball, and its canonical synopsis and description.
8429 Additional information such as the package dependencies and its
8430 license needs to be figured out manually.
8432 For example, the following command returns a package definition for
8436 guix import gnu hello
8439 Specific command-line options are:
8442 @item --key-download=@var{policy}
8443 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
8444 keys when verifying the package signature. @xref{Invoking guix
8445 refresh, @code{--key-download}}.
8450 Import metadata from the @uref{https://pypi.python.org/, Python Package
8451 Index}. Information is taken from the JSON-formatted description
8452 available at @code{pypi.python.org} and usually includes all the relevant
8453 information, including package dependencies. For maximum efficiency, it
8454 is recommended to install the @command{unzip} utility, so that the
8455 importer can unzip Python wheels and gather data from them.
8457 The command below imports metadata for the @code{itsdangerous} Python
8461 guix import pypi itsdangerous
8467 Traverse the dependency graph of the given upstream package recursively
8468 and generate package expressions for all those packages that are not yet
8474 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
8475 is taken from the JSON-formatted description available at
8476 @code{rubygems.org} and includes most relevant information, including
8477 runtime dependencies. There are some caveats, however. The metadata
8478 doesn't distinguish between synopses and descriptions, so the same string
8479 is used for both fields. Additionally, the details of non-Ruby
8480 dependencies required to build native extensions is unavailable and left
8481 as an exercise to the packager.
8483 The command below imports metadata for the @code{rails} Ruby package:
8486 guix import gem rails
8492 Traverse the dependency graph of the given upstream package recursively
8493 and generate package expressions for all those packages that are not yet
8499 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
8500 Information is taken from the JSON-formatted metadata provided through
8501 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
8502 relevant information, such as module dependencies. License information
8503 should be checked closely. If Perl is available in the store, then the
8504 @code{corelist} utility will be used to filter core modules out of the
8505 list of dependencies.
8507 The command command below imports metadata for the @code{Acme::Boolean}
8511 guix import cpan Acme::Boolean
8516 @cindex Bioconductor
8517 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
8518 central repository for the @uref{http://r-project.org, GNU@tie{}R
8519 statistical and graphical environment}.
8521 Information is extracted from the @code{DESCRIPTION} file of the package.
8523 The command command below imports metadata for the @code{Cairo}
8527 guix import cran Cairo
8530 When @code{--recursive} is added, the importer will traverse the
8531 dependency graph of the given upstream package recursively and generate
8532 package expressions for all those packages that are not yet in Guix.
8534 When @code{--archive=bioconductor} is added, metadata is imported from
8535 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
8536 packages for for the analysis and comprehension of high-throughput
8537 genomic data in bioinformatics.
8539 Information is extracted from the @code{DESCRIPTION} file of a package
8540 published on the web interface of the Bioconductor SVN repository.
8542 The command below imports metadata for the @code{GenomicRanges}
8546 guix import cran --archive=bioconductor GenomicRanges
8552 Import metadata from @uref{http://www.ctan.org/, CTAN}, the
8553 comprehensive TeX archive network for TeX packages that are part of the
8554 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
8556 Information about the package is obtained through the XML API provided
8557 by CTAN, while the source code is downloaded from the SVN repository of
8558 the Tex Live project. This is done because the CTAN does not keep
8561 The command command below imports metadata for the @code{fontspec}
8565 guix import texlive fontspec
8568 When @code{--archive=DIRECTORY} is added, the source code is downloaded
8569 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
8570 tree in the TeX Live SVN repository, but from the specified sibling
8571 directory under the same root.
8573 The command below imports metadata for the @code{ifxetex} package from
8574 CTAN while fetching the sources from the directory
8575 @file{texmf/source/generic}:
8578 guix import texlive --archive=generic ifxetex
8582 @cindex JSON, import
8583 Import package metadata from a local JSON file. Consider the following
8584 example package definition in JSON format:
8590 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
8591 "build-system": "gnu",
8592 "home-page": "https://www.gnu.org/software/hello/",
8593 "synopsis": "Hello, GNU world: An example GNU package",
8594 "description": "GNU Hello prints a greeting.",
8595 "license": "GPL-3.0+",
8596 "native-inputs": ["gcc@@6"]
8600 The field names are the same as for the @code{<package>} record
8601 (@xref{Defining Packages}). References to other packages are provided
8602 as JSON lists of quoted package specification strings such as
8603 @code{guile} or @code{guile@@2.0}.
8605 The importer also supports a more explicit source definition using the
8606 common fields for @code{<origin>} records:
8612 "method": "url-fetch",
8613 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
8615 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
8622 The command below reads metadata from the JSON file @code{hello.json}
8623 and outputs a package expression:
8626 guix import json hello.json
8630 Import metadata from a local copy of the source of the
8631 @uref{http://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
8632 relies on the @command{nix-instantiate} command of
8633 @uref{http://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
8634 typically written in a mixture of Nix-language and Bash code. This
8635 command only imports the high-level package structure that is written in
8636 the Nix language. It normally includes all the basic fields of a
8639 When importing a GNU package, the synopsis and descriptions are replaced
8640 by their canonical upstream variant.
8642 Usually, you will first need to do:
8645 export NIX_REMOTE=daemon
8649 so that @command{nix-instantiate} does not try to open the Nix database.
8651 As an example, the command below imports the package definition of
8652 LibreOffice (more precisely, it imports the definition of the package
8653 bound to the @code{libreoffice} top-level attribute):
8656 guix import nix ~/path/to/nixpkgs libreoffice
8661 Import metadata from the Haskell community's central package archive
8662 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
8663 Cabal files and includes all the relevant information, including package
8666 Specific command-line options are:
8671 Read a Cabal file from standard input.
8672 @item --no-test-dependencies
8674 Do not include dependencies required only by the test suites.
8675 @item --cabal-environment=@var{alist}
8676 @itemx -e @var{alist}
8677 @var{alist} is a Scheme alist defining the environment in which the
8678 Cabal conditionals are evaluated. The accepted keys are: @code{os},
8679 @code{arch}, @code{impl} and a string representing the name of a flag.
8680 The value associated with a flag has to be either the symbol
8681 @code{true} or @code{false}. The value associated with other keys
8682 has to conform to the Cabal file format definition. The default value
8683 associated with the keys @code{os}, @code{arch} and @code{impl} is
8684 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
8687 Traverse the dependency graph of the given upstream package recursively
8688 and generate package expressions for all those packages that are not yet
8692 The command below imports metadata for the latest version of the
8693 @code{HTTP} Haskell package without including test dependencies and
8694 specifying the value of the flag @samp{network-uri} as @code{false}:
8697 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
8700 A specific package version may optionally be specified by following the
8701 package name by an at-sign and a version number as in the following example:
8704 guix import hackage mtl@@2.1.3.1
8709 The @code{stackage} importer is a wrapper around the @code{hackage} one.
8710 It takes a package name, looks up the package version included in a
8711 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
8712 release and uses the @code{hackage} importer to retrieve its metadata.
8713 Note that it is up to you to select an LTS release compatible with the
8714 GHC compiler used by Guix.
8716 Specific command-line options are:
8719 @item --no-test-dependencies
8721 Do not include dependencies required only by the test suites.
8722 @item --lts-version=@var{version}
8723 @itemx -l @var{version}
8724 @var{version} is the desired LTS release version. If omitted the latest
8728 Traverse the dependency graph of the given upstream package recursively
8729 and generate package expressions for all those packages that are not yet
8733 The command below imports metadata for the @code{HTTP} Haskell package
8734 included in the LTS Stackage release version 7.18:
8737 guix import stackage --lts-version=7.18 HTTP
8742 Import metadata from an Emacs Lisp Package Archive (ELPA) package
8743 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
8745 Specific command-line options are:
8748 @item --archive=@var{repo}
8749 @itemx -a @var{repo}
8750 @var{repo} identifies the archive repository from which to retrieve the
8751 information. Currently the supported repositories and their identifiers
8755 @uref{http://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
8756 identifier. This is the default.
8758 Packages from @code{elpa.gnu.org} are signed with one of the keys
8759 contained in the GnuPG keyring at
8760 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
8761 @code{emacs} package (@pxref{Package Installation, ELPA package
8762 signatures,, emacs, The GNU Emacs Manual}).
8765 @uref{http://stable.melpa.org/packages, MELPA-Stable}, selected by the
8766 @code{melpa-stable} identifier.
8769 @uref{http://melpa.org/packages, MELPA}, selected by the @code{melpa}
8775 Traverse the dependency graph of the given upstream package recursively
8776 and generate package expressions for all those packages that are not yet
8782 Import metadata from the crates.io Rust package repository
8783 @uref{https://crates.io, crates.io}.
8788 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
8789 repository used by the OCaml community.
8792 The structure of the @command{guix import} code is modular. It would be
8793 useful to have more importers for other package formats, and your help
8794 is welcome here (@pxref{Contributing}).
8796 @node Invoking guix refresh
8797 @section Invoking @command{guix refresh}
8799 @cindex @command {guix refresh}
8800 The primary audience of the @command{guix refresh} command is developers
8801 of the GNU software distribution. By default, it reports any packages
8802 provided by the distribution that are outdated compared to the latest
8803 upstream version, like this:
8807 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
8808 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
8811 Alternately, one can specify packages to consider, in which case a
8812 warning is emitted for packages that lack an updater:
8815 $ guix refresh coreutils guile guile-ssh
8816 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
8817 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
8820 @command{guix refresh} browses the upstream repository of each package and determines
8821 the highest version number of the releases therein. The command
8822 knows how to update specific types of packages: GNU packages, ELPA
8823 packages, etc.---see the documentation for @option{--type} below. There
8824 are many packages, though, for which it lacks a method to determine
8825 whether a new upstream release is available. However, the mechanism is
8826 extensible, so feel free to get in touch with us to add a new method!
8831 Consider the packages specified, and all the packages upon which they depend.
8834 $ guix refresh --recursive coreutils
8835 gnu/packages/acl.scm:35:2: warning: no updater for acl
8836 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
8837 gnu/packages/xml.scm:68:2: warning: no updater for expat
8838 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
8844 Sometimes the upstream name differs from the package name used in Guix,
8845 and @command{guix refresh} needs a little help. Most updaters honor the
8846 @code{upstream-name} property in package definitions, which can be used
8850 (define-public network-manager
8852 (name "network-manager")
8854 (properties '((upstream-name . "NetworkManager")))))
8857 When passed @code{--update}, it modifies distribution source files to
8858 update the version numbers and source tarball hashes of those package
8859 recipes (@pxref{Defining Packages}). This is achieved by downloading
8860 each package's latest source tarball and its associated OpenPGP
8861 signature, authenticating the downloaded tarball against its signature
8862 using @command{gpg}, and finally computing its hash. When the public
8863 key used to sign the tarball is missing from the user's keyring, an
8864 attempt is made to automatically retrieve it from a public key server;
8865 when this is successful, the key is added to the user's keyring; otherwise,
8866 @command{guix refresh} reports an error.
8868 The following options are supported:
8872 @item --expression=@var{expr}
8873 @itemx -e @var{expr}
8874 Consider the package @var{expr} evaluates to.
8876 This is useful to precisely refer to a package, as in this example:
8879 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
8882 This command lists the dependents of the ``final'' libc (essentially all
8887 Update distribution source files (package recipes) in place. This is
8888 usually run from a checkout of the Guix source tree (@pxref{Running
8889 Guix Before It Is Installed}):
8892 $ ./pre-inst-env guix refresh -s non-core -u
8895 @xref{Defining Packages}, for more information on package definitions.
8897 @item --select=[@var{subset}]
8898 @itemx -s @var{subset}
8899 Select all the packages in @var{subset}, one of @code{core} or
8902 The @code{core} subset refers to all the packages at the core of the
8903 distribution---i.e., packages that are used to build ``everything
8904 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
8905 changing one of these packages in the distribution entails a rebuild of
8906 all the others. Thus, such updates are an inconvenience to users in
8907 terms of build time or bandwidth used to achieve the upgrade.
8909 The @code{non-core} subset refers to the remaining packages. It is
8910 typically useful in cases where an update of the core packages would be
8913 @item --manifest=@var{file}
8914 @itemx -m @var{file}
8915 Select all the packages from the manifest in @var{file}. This is useful to
8916 check if any packages of the user manifest can be updated.
8918 @item --type=@var{updater}
8919 @itemx -t @var{updater}
8920 Select only packages handled by @var{updater} (may be a comma-separated
8921 list of updaters). Currently, @var{updater} may be one of:
8925 the updater for GNU packages;
8927 the updater for GNOME packages;
8929 the updater for KDE packages;
8931 the updater for X.org packages;
8933 the updater for packages hosted on kernel.org;
8935 the updater for @uref{http://elpa.gnu.org/, ELPA} packages;
8937 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
8939 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
8941 the updater for @uref{http://www.cpan.org/, CPAN} packages;
8943 the updater for @uref{https://pypi.python.org, PyPI} packages.
8945 the updater for @uref{https://rubygems.org, RubyGems} packages.
8947 the updater for @uref{https://github.com, GitHub} packages.
8949 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
8951 the updater for @uref{https://www.stackage.org, Stackage} packages.
8953 the updater for @uref{https://crates.io, Crates} packages.
8955 the updater for @uref{https://launchpad.net, Launchpad} packages.
8958 For instance, the following command only checks for updates of Emacs
8959 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
8962 $ guix refresh --type=elpa,cran
8963 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
8964 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
8969 In addition, @command{guix refresh} can be passed one or more package
8970 names, as in this example:
8973 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
8977 The command above specifically updates the @code{emacs} and
8978 @code{idutils} packages. The @code{--select} option would have no
8979 effect in this case.
8981 When considering whether to upgrade a package, it is sometimes
8982 convenient to know which packages would be affected by the upgrade and
8983 should be checked for compatibility. For this the following option may
8984 be used when passing @command{guix refresh} one or more package names:
8988 @item --list-updaters
8990 List available updaters and exit (see @option{--type} above.)
8992 For each updater, display the fraction of packages it covers; at the
8993 end, display the fraction of packages covered by all these updaters.
8995 @item --list-dependent
8997 List top-level dependent packages that would need to be rebuilt as a
8998 result of upgrading one or more packages.
9000 @xref{Invoking guix graph, the @code{reverse-package} type of
9001 @command{guix graph}}, for information on how to visualize the list of
9002 dependents of a package.
9006 Be aware that the @code{--list-dependent} option only
9007 @emph{approximates} the rebuilds that would be required as a result of
9008 an upgrade. More rebuilds might be required under some circumstances.
9011 $ guix refresh --list-dependent flex
9012 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
9013 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
9016 The command above lists a set of packages that could be built to check
9017 for compatibility with an upgraded @code{flex} package.
9021 @item --list-transitive
9022 List all the packages which one or more packages depend upon.
9025 $ guix refresh --list-transitive flex
9026 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
9027 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{}
9032 The command above lists a set of packages which, when changed, would cause
9033 @code{flex} to be rebuilt.
9035 The following options can be used to customize GnuPG operation:
9039 @item --gpg=@var{command}
9040 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
9041 for in @code{$PATH}.
9043 @item --keyring=@var{file}
9044 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
9045 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
9046 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
9047 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
9048 information on a tool to manipulate keybox files).
9050 When this option is omitted, @command{guix refresh} uses
9051 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
9052 signing keys. OpenPGP signatures are checked against keys from this keyring;
9053 missing keys are downloaded to this keyring as well (see
9054 @option{--key-download} below.)
9056 You can export keys from your default GPG keyring into a keybox file using
9057 commands like this one:
9060 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
9063 Likewise, you can fetch keys to a specific keybox file like this:
9066 gpg --no-default-keyring --keyring mykeyring.kbx \
9067 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9070 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9071 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9073 @item --key-download=@var{policy}
9074 Handle missing OpenPGP keys according to @var{policy}, which may be one
9079 Always download missing OpenPGP keys from the key server, and add them
9080 to the user's GnuPG keyring.
9083 Never try to download missing OpenPGP keys. Instead just bail out.
9086 When a package signed with an unknown OpenPGP key is encountered, ask
9087 the user whether to download it or not. This is the default behavior.
9090 @item --key-server=@var{host}
9091 Use @var{host} as the OpenPGP key server when importing a public key.
9095 The @code{github} updater uses the
9096 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9097 releases. When used repeatedly e.g.@: when refreshing all packages,
9098 GitHub will eventually refuse to answer any further API requests. By
9099 default 60 API requests per hour are allowed, and a full refresh on all
9100 GitHub packages in Guix requires more than this. Authentication with
9101 GitHub through the use of an API token alleviates these limits. To use
9102 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9103 token procured from @uref{https://github.com/settings/tokens} or
9107 @node Invoking guix lint
9108 @section Invoking @command{guix lint}
9110 @cindex @command{guix lint}
9111 @cindex package, checking for errors
9112 The @command{guix lint} command is meant to help package developers avoid
9113 common errors and use a consistent style. It runs a number of checks on
9114 a given set of packages in order to find common mistakes in their
9115 definitions. Available @dfn{checkers} include (see
9116 @code{--list-checkers} for a complete list):
9121 Validate certain typographical and stylistic rules about package
9122 descriptions and synopses.
9124 @item inputs-should-be-native
9125 Identify inputs that should most likely be native inputs.
9131 @itemx source-file-name
9132 Probe @code{home-page} and @code{source} URLs and report those that are
9133 invalid. Suggest a @code{mirror://} URL when applicable. If the
9134 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9135 URL. Check that the source file name is meaningful, e.g.@: is not just a
9136 version number or ``git-checkout'', without a declared @code{file-name}
9137 (@pxref{origin Reference}).
9139 @item source-unstable-tarball
9140 Parse the @code{source} URL to determine if a tarball from GitHub is
9141 autogenerated or if it is a release tarball. Unfortunately GitHub's
9142 autogenerated tarballs are sometimes regenerated.
9145 @cindex security vulnerabilities
9146 @cindex CVE, Common Vulnerabilities and Exposures
9147 Report known vulnerabilities found in the Common Vulnerabilities and
9148 Exposures (CVE) databases of the current and past year
9149 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
9152 To view information about a particular vulnerability, visit pages such as:
9156 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9158 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9162 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9163 @code{CVE-2015-7554}.
9165 Package developers can specify in package recipes the
9166 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
9167 name and version of the package when they differ from the name or version
9168 that Guix uses, as in this example:
9174 ;; CPE calls this package "grub2".
9175 (properties '((cpe-name . "grub2")
9176 (cpe-version . "2.3")))
9179 @c See <http://www.openwall.com/lists/oss-security/2017/03/15/3>.
9180 Some entries in the CVE database do not specify which version of a
9181 package they apply to, and would thus ``stick around'' forever. Package
9182 developers who found CVE alerts and verified they can be ignored can
9183 declare them as in this example:
9189 ;; These CVEs no longer apply and can be safely ignored.
9190 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9193 "CVE-2011-5244")))))
9197 Warn about obvious source code formatting issues: trailing white space,
9198 use of tabulations, etc.
9201 The general syntax is:
9204 guix lint @var{options} @var{package}@dots{}
9207 If no package is given on the command line, then all packages are checked.
9208 The @var{options} may be zero or more of the following:
9211 @item --list-checkers
9213 List and describe all the available checkers that will be run on packages
9218 Only enable the checkers specified in a comma-separated list using the
9219 names returned by @code{--list-checkers}.
9223 @node Invoking guix size
9224 @section Invoking @command{guix size}
9227 @cindex package size
9229 @cindex @command{guix size}
9230 The @command{guix size} command helps package developers profile the
9231 disk usage of packages. It is easy to overlook the impact of an
9232 additional dependency added to a package, or the impact of using a
9233 single output for a package that could easily be split (@pxref{Packages
9234 with Multiple Outputs}). Such are the typical issues that
9235 @command{guix size} can highlight.
9237 The command can be passed one or more package specifications
9238 such as @code{gcc@@4.8}
9239 or @code{guile:debug}, or a file name in the store. Consider this
9243 $ guix size coreutils
9244 store item total self
9245 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9246 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9247 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9248 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9249 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9250 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9251 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9252 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9257 The store items listed here constitute the @dfn{transitive closure} of
9258 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9259 would be returned by:
9262 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9265 Here the output shows three columns next to store items. The first column,
9266 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9267 the store item---that is, its own size plus the size of all its
9268 dependencies. The next column, labeled ``self'', shows the size of the
9269 item itself. The last column shows the ratio of the size of the item
9270 itself to the space occupied by all the items listed here.
9272 In this example, we see that the closure of Coreutils weighs in at
9273 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9274 libraries. (That libc and GCC's libraries represent a large fraction of
9275 the closure is not a problem @i{per se} because they are always available
9276 on the system anyway.)
9278 When the package(s) passed to @command{guix size} are available in the
9279 store@footnote{More precisely, @command{guix size} looks for the
9280 @emph{ungrafted} variant of the given package(s), as returned by
9281 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9282 for information on grafts.}, @command{guix size} queries the daemon to determine its
9283 dependencies, and measures its size in the store, similar to @command{du
9284 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9287 When the given packages are @emph{not} in the store, @command{guix size}
9288 reports information based on the available substitutes
9289 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9290 store items that are not even on disk, only available remotely.
9292 You can also specify several package names:
9295 $ guix size coreutils grep sed bash
9296 store item total self
9297 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9298 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9299 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9300 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
9306 In this example we see that the combination of the four packages takes
9307 102.3@tie{}MiB in total, which is much less than the sum of each closure
9308 since they have a lot of dependencies in common.
9310 The available options are:
9314 @item --substitute-urls=@var{urls}
9315 Use substitute information from @var{urls}.
9316 @xref{client-substitute-urls, the same option for @code{guix build}}.
9318 @item --sort=@var{key}
9319 Sort lines according to @var{key}, one of the following options:
9323 the size of each item (the default);
9325 the total size of the item's closure.
9328 @item --map-file=@var{file}
9329 Write a graphical map of disk usage in PNG format to @var{file}.
9331 For the example above, the map looks like this:
9333 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
9334 produced by @command{guix size}}
9336 This option requires that
9337 @uref{http://wingolog.org/software/guile-charting/, Guile-Charting} be
9338 installed and visible in Guile's module search path. When that is not
9339 the case, @command{guix size} fails as it tries to load it.
9341 @item --system=@var{system}
9342 @itemx -s @var{system}
9343 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
9347 @node Invoking guix graph
9348 @section Invoking @command{guix graph}
9351 @cindex @command{guix graph}
9352 @cindex package dependencies
9353 Packages and their dependencies form a @dfn{graph}, specifically a
9354 directed acyclic graph (DAG). It can quickly become difficult to have a
9355 mental model of the package DAG, so the @command{guix graph} command
9356 provides a visual representation of the DAG. By default,
9357 @command{guix graph} emits a DAG representation in the input format of
9358 @uref{http://www.graphviz.org/, Graphviz}, so its output can be passed
9359 directly to the @command{dot} command of Graphviz. It can also emit an
9360 HTML page with embedded JavaScript code to display a ``chord diagram''
9361 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
9362 emit Cypher queries to construct a graph in a graph database supporting
9363 the @uref{http://www.opencypher.org/, openCypher} query language.
9364 The general syntax is:
9367 guix graph @var{options} @var{package}@dots{}
9370 For example, the following command generates a PDF file representing the
9371 package DAG for the GNU@tie{}Core Utilities, showing its build-time
9375 guix graph coreutils | dot -Tpdf > dag.pdf
9378 The output looks like this:
9380 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
9382 Nice little graph, no?
9384 But there is more than one graph! The one above is concise: it is the
9385 graph of package objects, omitting implicit inputs such as GCC, libc,
9386 grep, etc. It is often useful to have such a concise graph, but
9387 sometimes one may want to see more details. @command{guix graph} supports
9388 several types of graphs, allowing you to choose the level of detail:
9392 This is the default type used in the example above. It shows the DAG of
9393 package objects, excluding implicit dependencies. It is concise, but
9394 filters out many details.
9396 @item reverse-package
9397 This shows the @emph{reverse} DAG of packages. For example:
9400 guix graph --type=reverse-package ocaml
9403 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
9404 you are also interested in cases where OCaml is an implicit dependency, see
9405 @code{reverse-bag} below.)
9407 Note that for core packages this can yield huge graphs. If all you want
9408 is to know the number of packages that depend on a given package, use
9409 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
9410 @option{--list-dependent}}).
9413 This is the package DAG, @emph{including} implicit inputs.
9415 For instance, the following command:
9418 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
9421 ...@: yields this bigger graph:
9423 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
9425 At the bottom of the graph, we see all the implicit inputs of
9426 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
9428 Now, note that the dependencies of these implicit inputs---that is, the
9429 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
9430 here, for conciseness.
9433 Similar to @code{bag-emerged}, but this time including all the bootstrap
9436 @item bag-with-origins
9437 Similar to @code{bag}, but also showing origins and their dependencies.
9440 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
9441 it also takes implicit dependencies into account. For example:
9444 guix graph -t reverse-bag dune
9448 ...@: yields the graph of all packages that depend on Dune, directly or
9449 indirectly. Since Dune is an @emph{implicit} dependency of many packages
9450 @i{via} @code{dune-build-system}, this shows a large number of packages,
9451 whereas @code{reverse-package} would show very few if any.
9454 This is the most detailed representation: It shows the DAG of
9455 derivations (@pxref{Derivations}) and plain store items. Compared to
9456 the above representation, many additional nodes are visible, including
9457 build scripts, patches, Guile modules, etc.
9459 For this type of graph, it is also possible to pass a @file{.drv} file
9460 name instead of a package name, as in:
9463 guix graph -t derivation `guix system build -d my-config.scm`
9467 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
9468 For example, the following command shows the graph for the package
9469 module that defines the @code{guile} package:
9472 guix graph -t module guile | dot -Tpdf > module-graph.pdf
9476 All the types above correspond to @emph{build-time dependencies}. The
9477 following graph type represents the @emph{run-time dependencies}:
9481 This is the graph of @dfn{references} of a package output, as returned
9482 by @command{guix gc --references} (@pxref{Invoking guix gc}).
9484 If the given package output is not available in the store, @command{guix
9485 graph} attempts to obtain dependency information from substitutes.
9487 Here you can also pass a store file name instead of a package name. For
9488 example, the command below produces the reference graph of your profile
9489 (which can be big!):
9492 guix graph -t references `readlink -f ~/.guix-profile`
9496 This is the graph of the @dfn{referrers} of a store item, as returned by
9497 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
9499 This relies exclusively on local information from your store. For
9500 instance, let us suppose that the current Inkscape is available in 10
9501 profiles on your machine; @command{guix graph -t referrers inkscape}
9502 will show a graph rooted at Inkscape and with those 10 profiles linked
9505 It can help determine what is preventing a store item from being garbage
9510 The available options are the following:
9513 @item --type=@var{type}
9514 @itemx -t @var{type}
9515 Produce a graph output of @var{type}, where @var{type} must be one of
9516 the values listed above.
9519 List the supported graph types.
9521 @item --backend=@var{backend}
9522 @itemx -b @var{backend}
9523 Produce a graph using the selected @var{backend}.
9525 @item --list-backends
9526 List the supported graph backends.
9528 Currently, the available backends are Graphviz and d3.js.
9530 @item --expression=@var{expr}
9531 @itemx -e @var{expr}
9532 Consider the package @var{expr} evaluates to.
9534 This is useful to precisely refer to a package, as in this example:
9537 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
9540 @item --system=@var{system}
9541 @itemx -s @var{system}
9542 Display the graph for @var{system}---e.g., @code{i686-linux}.
9544 The package dependency graph is largely architecture-independent, but there
9545 are some architecture-dependent bits that this option allows you to visualize.
9550 @node Invoking guix publish
9551 @section Invoking @command{guix publish}
9553 @cindex @command{guix publish}
9554 The purpose of @command{guix publish} is to enable users to easily share
9555 their store with others, who can then use it as a substitute server
9556 (@pxref{Substitutes}).
9558 When @command{guix publish} runs, it spawns an HTTP server which allows
9559 anyone with network access to obtain substitutes from it. This means
9560 that any machine running Guix can also act as if it were a build farm,
9561 since the HTTP interface is compatible with Hydra, the software behind
9562 the @code{@value{SUBSTITUTE-SERVER}} build farm.
9564 For security, each substitute is signed, allowing recipients to check
9565 their authenticity and integrity (@pxref{Substitutes}). Because
9566 @command{guix publish} uses the signing key of the system, which is only
9567 readable by the system administrator, it must be started as root; the
9568 @code{--user} option makes it drop root privileges early on.
9570 The signing key pair must be generated before @command{guix publish} is
9571 launched, using @command{guix archive --generate-key} (@pxref{Invoking
9574 The general syntax is:
9577 guix publish @var{options}@dots{}
9580 Running @command{guix publish} without any additional arguments will
9581 spawn an HTTP server on port 8080:
9587 Once a publishing server has been authorized (@pxref{Invoking guix
9588 archive}), the daemon may download substitutes from it:
9591 guix-daemon --substitute-urls=http://example.org:8080
9594 By default, @command{guix publish} compresses archives on the fly as it
9595 serves them. This ``on-the-fly'' mode is convenient in that it requires
9596 no setup and is immediately available. However, when serving lots of
9597 clients, we recommend using the @option{--cache} option, which enables
9598 caching of the archives before they are sent to clients---see below for
9599 details. The @command{guix weather} command provides a handy way to
9600 check what a server provides (@pxref{Invoking guix weather}).
9602 As a bonus, @command{guix publish} also serves as a content-addressed
9603 mirror for source files referenced in @code{origin} records
9604 (@pxref{origin Reference}). For instance, assuming @command{guix
9605 publish} is running on @code{example.org}, the following URL returns the
9606 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
9607 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
9610 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
9613 Obviously, these URLs only work for files that are in the store; in
9614 other cases, they return 404 (``Not Found'').
9616 @cindex build logs, publication
9617 Build logs are available from @code{/log} URLs like:
9620 http://example.org/log/gwspk@dots{}-guile-2.2.3
9624 When @command{guix-daemon} is configured to save compressed build logs,
9625 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
9626 URLs return the compressed log as-is, with an appropriate
9627 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
9628 running @command{guix-daemon} with @code{--log-compression=gzip} since
9629 Web browsers can automatically decompress it, which is not the case with
9632 The following options are available:
9635 @item --port=@var{port}
9636 @itemx -p @var{port}
9637 Listen for HTTP requests on @var{port}.
9639 @item --listen=@var{host}
9640 Listen on the network interface for @var{host}. The default is to
9641 accept connections from any interface.
9643 @item --user=@var{user}
9644 @itemx -u @var{user}
9645 Change privileges to @var{user} as soon as possible---i.e., once the
9646 server socket is open and the signing key has been read.
9648 @item --compression[=@var{level}]
9649 @itemx -C [@var{level}]
9650 Compress data using the given @var{level}. When @var{level} is zero,
9651 disable compression. The range 1 to 9 corresponds to different gzip
9652 compression levels: 1 is the fastest, and 9 is the best (CPU-intensive).
9655 Unless @option{--cache} is used, compression occurs on the fly and
9656 the compressed streams are not
9657 cached. Thus, to reduce load on the machine that runs @command{guix
9658 publish}, it may be a good idea to choose a low compression level, to
9659 run @command{guix publish} behind a caching proxy, or to use
9660 @option{--cache}. Using @option{--cache} has the advantage that it
9661 allows @command{guix publish} to add @code{Content-Length} HTTP header
9664 @item --cache=@var{directory}
9665 @itemx -c @var{directory}
9666 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
9667 and only serve archives that are in cache.
9669 When this option is omitted, archives and meta-data are created
9670 on-the-fly. This can reduce the available bandwidth, especially when
9671 compression is enabled, since this may become CPU-bound. Another
9672 drawback of the default mode is that the length of archives is not known
9673 in advance, so @command{guix publish} does not add a
9674 @code{Content-Length} HTTP header to its responses, which in turn
9675 prevents clients from knowing the amount of data being downloaded.
9677 Conversely, when @option{--cache} is used, the first request for a store
9678 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
9679 background process to @dfn{bake} the archive---computing its
9680 @code{.narinfo} and compressing the archive, if needed. Once the
9681 archive is cached in @var{directory}, subsequent requests succeed and
9682 are served directly from the cache, which guarantees that clients get
9683 the best possible bandwidth.
9685 The ``baking'' process is performed by worker threads. By default, one
9686 thread per CPU core is created, but this can be customized. See
9687 @option{--workers} below.
9689 When @option{--ttl} is used, cached entries are automatically deleted
9690 when they have expired.
9692 @item --workers=@var{N}
9693 When @option{--cache} is used, request the allocation of @var{N} worker
9694 threads to ``bake'' archives.
9696 @item --ttl=@var{ttl}
9697 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
9698 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
9699 days, @code{1m} means 1 month, and so on.
9701 This allows the user's Guix to keep substitute information in cache for
9702 @var{ttl}. However, note that @code{guix publish} does not itself
9703 guarantee that the store items it provides will indeed remain available
9704 for as long as @var{ttl}.
9706 Additionally, when @option{--cache} is used, cached entries that have
9707 not been accessed for @var{ttl} and that no longer have a corresponding
9708 item in the store, may be deleted.
9710 @item --nar-path=@var{path}
9711 Use @var{path} as the prefix for the URLs of ``nar'' files
9712 (@pxref{Invoking guix archive, normalized archives}).
9714 By default, nars are served at a URL such as
9715 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
9716 change the @code{/nar} part to @var{path}.
9718 @item --public-key=@var{file}
9719 @itemx --private-key=@var{file}
9720 Use the specific @var{file}s as the public/private key pair used to sign
9721 the store items being published.
9723 The files must correspond to the same key pair (the private key is used
9724 for signing and the public key is merely advertised in the signature
9725 metadata). They must contain keys in the canonical s-expression format
9726 as produced by @command{guix archive --generate-key} (@pxref{Invoking
9727 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
9728 @file{/etc/guix/signing-key.sec} are used.
9730 @item --repl[=@var{port}]
9731 @itemx -r [@var{port}]
9732 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
9733 Reference Manual}) on @var{port} (37146 by default). This is used
9734 primarily for debugging a running @command{guix publish} server.
9737 Enabling @command{guix publish} on Guix System is a one-liner: just
9738 instantiate a @code{guix-publish-service-type} service in the @code{services} field
9739 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
9740 @code{guix-publish-service-type}}).
9742 If you are instead running Guix on a ``foreign distro'', follow these
9747 If your host distro uses the systemd init system:
9750 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
9751 /etc/systemd/system/
9752 # systemctl start guix-publish && systemctl enable guix-publish
9756 If your host distro uses the Upstart init system:
9759 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
9760 # start guix-publish
9764 Otherwise, proceed similarly with your distro's init system.
9767 @node Invoking guix challenge
9768 @section Invoking @command{guix challenge}
9770 @cindex reproducible builds
9771 @cindex verifiable builds
9772 @cindex @command{guix challenge}
9774 Do the binaries provided by this server really correspond to the source
9775 code it claims to build? Is a package build process deterministic?
9776 These are the questions the @command{guix challenge} command attempts to
9779 The former is obviously an important question: Before using a substitute
9780 server (@pxref{Substitutes}), one had better @emph{verify} that it
9781 provides the right binaries, and thus @emph{challenge} it. The latter
9782 is what enables the former: If package builds are deterministic, then
9783 independent builds of the package should yield the exact same result,
9784 bit for bit; if a server provides a binary different from the one
9785 obtained locally, it may be either corrupt or malicious.
9787 We know that the hash that shows up in @file{/gnu/store} file names is
9788 the hash of all the inputs of the process that built the file or
9789 directory---compilers, libraries, build scripts,
9790 etc. (@pxref{Introduction}). Assuming deterministic build processes,
9791 one store file name should map to exactly one build output.
9792 @command{guix challenge} checks whether there is, indeed, a single
9793 mapping by comparing the build outputs of several independent builds of
9794 any given store item.
9796 The command output looks like this:
9799 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
9800 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
9801 updating list of substitutes from 'https://guix.example.org'... 100.0%
9802 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
9803 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9804 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9805 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
9806 /gnu/store/@dots{}-git-2.5.0 contents differ:
9807 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
9808 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
9809 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
9810 /gnu/store/@dots{}-pius-2.1.1 contents differ:
9811 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9812 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9813 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
9817 6,406 store items were analyzed:
9818 - 4,749 (74.1%) were identical
9819 - 525 (8.2%) differed
9820 - 1,132 (17.7%) were inconclusive
9824 In this example, @command{guix challenge} first scans the store to
9825 determine the set of locally-built derivations---as opposed to store
9826 items that were downloaded from a substitute server---and then queries
9827 all the substitute servers. It then reports those store items for which
9828 the servers obtained a result different from the local build.
9830 @cindex non-determinism, in package builds
9831 As an example, @code{guix.example.org} always gets a different answer.
9832 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
9833 case of Git. This might indicate that the build process of Git is
9834 non-deterministic, meaning that its output varies as a function of
9835 various things that Guix does not fully control, in spite of building
9836 packages in isolated environments (@pxref{Features}). Most common
9837 sources of non-determinism include the addition of timestamps in build
9838 results, the inclusion of random numbers, and directory listings sorted
9839 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
9842 To find out what is wrong with this Git binary, we can do something along
9843 these lines (@pxref{Invoking guix archive}):
9846 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
9847 | guix archive -x /tmp/git
9848 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
9851 This command shows the difference between the files resulting from the
9852 local build, and the files resulting from the build on
9853 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
9854 diffutils, Comparing and Merging Files}). The @command{diff} command
9855 works great for text files. When binary files differ, a better option
9856 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
9857 visualize differences for all kinds of files.
9859 Once you have done that work, you can tell whether the differences are due
9860 to a non-deterministic build process or to a malicious server. We try
9861 hard to remove sources of non-determinism in packages to make it easier
9862 to verify substitutes, but of course, this is a process that
9863 involves not just Guix, but a large part of the free software community.
9864 In the meantime, @command{guix challenge} is one tool to help address
9867 If you are writing packages for Guix, you are encouraged to check
9868 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
9869 same build result as you did with:
9872 $ guix challenge @var{package}
9876 where @var{package} is a package specification such as
9877 @code{guile@@2.0} or @code{glibc:debug}.
9879 The general syntax is:
9882 guix challenge @var{options} [@var{packages}@dots{}]
9885 When a difference is found between the hash of a locally-built item and
9886 that of a server-provided substitute, or among substitutes provided by
9887 different servers, the command displays it as in the example above and
9888 its exit code is 2 (other non-zero exit codes denote other kinds of
9891 The one option that matters is:
9895 @item --substitute-urls=@var{urls}
9896 Consider @var{urls} the whitespace-separated list of substitute source
9901 Show details about matches (identical contents) in addition to
9902 information about mismatches.
9906 @node Invoking guix copy
9907 @section Invoking @command{guix copy}
9909 @cindex copy, of store items, over SSH
9910 @cindex SSH, copy of store items
9911 @cindex sharing store items across machines
9912 @cindex transferring store items across machines
9913 The @command{guix copy} command copies items from the store of one
9914 machine to that of another machine over a secure shell (SSH)
9915 connection@footnote{This command is available only when Guile-SSH was
9916 found. @xref{Requirements}, for details.}. For example, the following
9917 command copies the @code{coreutils} package, the user's profile, and all
9918 their dependencies over to @var{host}, logged in as @var{user}:
9921 guix copy --to=@var{user}@@@var{host} \
9922 coreutils `readlink -f ~/.guix-profile`
9925 If some of the items to be copied are already present on @var{host},
9926 they are not actually sent.
9928 The command below retrieves @code{libreoffice} and @code{gimp} from
9929 @var{host}, assuming they are available there:
9932 guix copy --from=@var{host} libreoffice gimp
9935 The SSH connection is established using the Guile-SSH client, which is
9936 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
9937 @file{~/.ssh/config}, and uses the SSH agent for authentication.
9939 The key used to sign items that are sent must be accepted by the remote
9940 machine. Likewise, the key used by the remote machine to sign items you
9941 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
9942 own daemon. @xref{Invoking guix archive}, for more information about
9943 store item authentication.
9945 The general syntax is:
9948 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
9951 You must always specify one of the following options:
9954 @item --to=@var{spec}
9955 @itemx --from=@var{spec}
9956 Specify the host to send to or receive from. @var{spec} must be an SSH
9957 spec such as @code{example.org}, @code{charlie@@example.org}, or
9958 @code{charlie@@example.org:2222}.
9961 The @var{items} can be either package names, such as @code{gimp}, or
9962 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
9964 When specifying the name of a package to send, it is first built if
9965 needed, unless @option{--dry-run} was specified. Common build options
9966 are supported (@pxref{Common Build Options}).
9969 @node Invoking guix container
9970 @section Invoking @command{guix container}
9972 @cindex @command{guix container}
9974 As of version @value{VERSION}, this tool is experimental. The interface
9975 is subject to radical change in the future.
9978 The purpose of @command{guix container} is to manipulate processes
9979 running within an isolated environment, commonly known as a
9980 ``container'', typically created by the @command{guix environment}
9981 (@pxref{Invoking guix environment}) and @command{guix system container}
9982 (@pxref{Invoking guix system}) commands.
9984 The general syntax is:
9987 guix container @var{action} @var{options}@dots{}
9990 @var{action} specifies the operation to perform with a container, and
9991 @var{options} specifies the context-specific arguments for the action.
9993 The following actions are available:
9997 Execute a command within the context of a running container.
10002 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
10005 @var{pid} specifies the process ID of the running container.
10006 @var{program} specifies an executable file name within the root file
10007 system of the container. @var{arguments} are the additional options that
10008 will be passed to @var{program}.
10010 The following command launches an interactive login shell inside a
10011 Guix system container, started by @command{guix system container}, and whose
10012 process ID is 9001:
10015 guix container exec 9001 /run/current-system/profile/bin/bash --login
10018 Note that the @var{pid} cannot be the parent process of a container. It
10019 must be PID 1 of the container or one of its child processes.
10023 @node Invoking guix weather
10024 @section Invoking @command{guix weather}
10026 Occasionally you're grumpy because substitutes are lacking and you end
10027 up building packages by yourself (@pxref{Substitutes}). The
10028 @command{guix weather} command reports on substitute availability on the
10029 specified servers so you can have an idea of whether you'll be grumpy
10030 today. It can sometimes be useful info as a user, but it is primarily
10031 useful to people running @command{guix publish} (@pxref{Invoking guix
10034 @cindex statistics, for substitutes
10035 @cindex availability of substitutes
10036 @cindex substitute availability
10037 @cindex weather, substitute availability
10038 Here's a sample run:
10041 $ guix weather --substitute-urls=https://guix.example.org
10042 computing 5,872 package derivations for x86_64-linux...
10043 looking for 6,128 store items on https://guix.example.org..
10044 updating list of substitutes from 'https://guix.example.org'... 100.0%
10045 https://guix.example.org
10046 43.4% substitutes available (2,658 out of 6,128)
10047 7,032.5 MiB of nars (compressed)
10048 19,824.2 MiB on disk (uncompressed)
10049 0.030 seconds per request (182.9 seconds in total)
10050 33.5 requests per second
10052 9.8% (342 out of 3,470) of the missing items are queued
10054 x86_64-linux: 518 (59.7%)
10055 i686-linux: 221 (25.5%)
10056 aarch64-linux: 128 (14.8%)
10057 build rate: 23.41 builds per hour
10058 x86_64-linux: 11.16 builds per hour
10059 i686-linux: 6.03 builds per hour
10060 aarch64-linux: 6.41 builds per hour
10063 @cindex continuous integration, statistics
10064 As you can see, it reports the fraction of all the packages for which
10065 substitutes are available on the server---regardless of whether
10066 substitutes are enabled, and regardless of whether this server's signing
10067 key is authorized. It also reports the size of the compressed archives
10068 (``nars'') provided by the server, the size the corresponding store
10069 items occupy in the store (assuming deduplication is turned off), and
10070 the server's throughput. The second part gives continuous integration
10071 (CI) statistics, if the server supports it. In addition, using the
10072 @option{--coverage} option, @command{guix weather} can list ``important''
10073 package substitutes missing on the server (see below).
10075 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10076 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10077 challenge}, it ignores signatures on those substitutes, which is
10078 innocuous since the command only gathers statistics and cannot install
10081 Among other things, it is possible to query specific system types and
10082 specific package sets. The available options are listed below.
10085 @item --substitute-urls=@var{urls}
10086 @var{urls} is the space-separated list of substitute server URLs to
10087 query. When this option is omitted, the default set of substitute
10088 servers is queried.
10090 @item --system=@var{system}
10091 @itemx -s @var{system}
10092 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10093 option can be repeated, in which case @command{guix weather} will query
10094 substitutes for several system types.
10096 @item --manifest=@var{file}
10097 Instead of querying substitutes for all the packages, only ask for those
10098 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10099 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10102 @item --coverage[=@var{count}]
10103 @itemx -c [@var{count}]
10104 Report on substitute coverage for packages: list packages with at least
10105 @var{count} dependents (zero by default) for which substitutes are
10106 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10107 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10108 @var{b} usually lacks substitutes as well. The result looks like this:
10111 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
10112 computing 8,983 package derivations for x86_64-linux...
10113 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
10114 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
10115 @value{SUBSTITUTE-URL}
10116 64.7% substitutes available (6,047 out of 9,343)
10118 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
10119 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10120 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10121 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10125 What this example shows is that @code{kcoreaddons} and presumably the 58
10126 packages that depend on it have no substitutes at @code{ci.guix.info};
10127 likewise for @code{qgpgme} and the 46 packages that depend on it.
10129 If you are a Guix developer, or if you are taking care of this build farm,
10130 you'll probably want to have a closer look at these packages: they may simply
10134 @node Invoking guix processes
10135 @section Invoking @command{guix processes}
10137 The @command{guix processes} command can be useful to developers and system
10138 administrators, especially on multi-user machines and on build farms: it lists
10139 the current sessions (connections to the daemon), as well as information about
10140 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10141 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10142 listed.}. Here's an example of the information it returns:
10145 $ sudo guix processes
10148 ClientCommand: guix environment --ad-hoc python
10152 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10156 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10157 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10158 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10159 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10160 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10161 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10162 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10165 In this example we see that @command{guix-daemon} has three clients:
10166 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10167 integration tool; their process identifier (PID) is given by the
10168 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10169 @command{guix-daemon} sub-process of this particular session.
10171 The @code{LockHeld} fields show which store items are currently locked by this
10172 session, which corresponds to store items being built or substituted (the
10173 @code{LockHeld} field is not displayed when @command{guix processes} is not
10174 running as root.) Last, by looking at the @code{ChildProcess} field, we
10175 understand that these three builds are being offloaded (@pxref{Daemon Offload
10178 The output is in Recutils format so we can use the handy @command{recsel}
10179 command to select sessions of interest (@pxref{Selection Expressions,,,
10180 recutils, GNU recutils manual}). As an example, the command shows the command
10181 line and PID of the client that triggered the build of a Perl package:
10184 $ sudo guix processes | \
10185 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10187 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10191 @node System Configuration
10192 @chapter System Configuration
10194 @cindex system configuration
10195 Guix System supports a consistent whole-system configuration
10196 mechanism. By that we mean that all aspects of the global system
10197 configuration---such as the available system services, timezone and
10198 locale settings, user accounts---are declared in a single place. Such
10199 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10201 One of the advantages of putting all the system configuration under the
10202 control of Guix is that it supports transactional system upgrades, and
10203 makes it possible to roll back to a previous system instantiation,
10204 should something go wrong with the new one (@pxref{Features}). Another
10205 advantage is that it makes it easy to replicate the exact same configuration
10206 across different machines, or at different points in time, without
10207 having to resort to additional administration tools layered on top of
10208 the own tools of the system.
10209 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
10211 This section describes this mechanism. First we focus on the system
10212 administrator's viewpoint---explaining how the system is configured and
10213 instantiated. Then we show how this mechanism can be extended, for
10214 instance to support new system services.
10217 * Using the Configuration System:: Customizing your GNU system.
10218 * operating-system Reference:: Detail of operating-system declarations.
10219 * File Systems:: Configuring file system mounts.
10220 * Mapped Devices:: Block device extra processing.
10221 * User Accounts:: Specifying user accounts.
10222 * Keyboard Layout:: How the system interprets key strokes.
10223 * Locales:: Language and cultural convention settings.
10224 * Services:: Specifying system services.
10225 * Setuid Programs:: Programs running with root privileges.
10226 * X.509 Certificates:: Authenticating HTTPS servers.
10227 * Name Service Switch:: Configuring libc's name service switch.
10228 * Initial RAM Disk:: Linux-Libre bootstrapping.
10229 * Bootloader Configuration:: Configuring the boot loader.
10230 * Invoking guix system:: Instantiating a system configuration.
10231 * Running Guix in a VM:: How to run Guix System in a virtual machine.
10232 * Defining Services:: Adding new service definitions.
10235 @node Using the Configuration System
10236 @section Using the Configuration System
10238 The operating system is configured by providing an
10239 @code{operating-system} declaration in a file that can then be passed to
10240 the @command{guix system} command (@pxref{Invoking guix system}). A
10241 simple setup, with the default system services, the default Linux-Libre
10242 kernel, initial RAM disk, and boot loader looks like this:
10244 @findex operating-system
10246 @include os-config-bare-bones.texi
10249 This example should be self-describing. Some of the fields defined
10250 above, such as @code{host-name} and @code{bootloader}, are mandatory.
10251 Others, such as @code{packages} and @code{services}, can be omitted, in
10252 which case they get a default value.
10254 Below we discuss the effect of some of the most important fields
10255 (@pxref{operating-system Reference}, for details about all the available
10256 fields), and how to @dfn{instantiate} the operating system using
10257 @command{guix system}.
10259 @unnumberedsubsec Bootloader
10261 @cindex legacy boot, on Intel machines
10262 @cindex BIOS boot, on Intel machines
10265 The @code{bootloader} field describes the method that will be used to boot
10266 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
10267 mode, as in the example above. However, more recent machines rely instead on
10268 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
10269 the @code{bootloader} field should contain something along these lines:
10272 (bootloader-configuration
10273 (bootloader grub-efi-bootloader)
10274 (target "/boot/efi"))
10277 @xref{Bootloader Configuration}, for more information on the available
10278 configuration options.
10280 @unnumberedsubsec Globally-Visible Packages
10282 @vindex %base-packages
10283 The @code{packages} field lists packages that will be globally visible
10284 on the system, for all user accounts---i.e., in every user's @code{PATH}
10285 environment variable---in addition to the per-user profiles
10286 (@pxref{Invoking guix package}). The @var{%base-packages} variable
10287 provides all the tools one would expect for basic user and administrator
10288 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
10289 the GNU Zile lightweight text editor, @command{find}, @command{grep},
10290 etc. The example above adds GNU@tie{}Screen to those,
10291 taken from the @code{(gnu packages screen)}
10292 module (@pxref{Package Modules}). The
10293 @code{(list package output)} syntax can be used to add a specific output
10297 (use-modules (gnu packages))
10298 (use-modules (gnu packages dns))
10302 (packages (cons (list bind "utils")
10306 @findex specification->package
10307 Referring to packages by variable name, like @code{bind} above, has
10308 the advantage of being unambiguous; it also allows typos and such to be
10309 diagnosed right away as ``unbound variables''. The downside is that one
10310 needs to know which module defines which package, and to augment the
10311 @code{use-package-modules} line accordingly. To avoid that, one can use
10312 the @code{specification->package} procedure of the @code{(gnu packages)}
10313 module, which returns the best package for a given name or name and
10317 (use-modules (gnu packages))
10321 (packages (append (map specification->package
10322 '("tcpdump" "htop" "gnupg@@2.0"))
10326 @unnumberedsubsec System Services
10329 @vindex %base-services
10330 The @code{services} field lists @dfn{system services} to be made
10331 available when the system starts (@pxref{Services}).
10332 The @code{operating-system} declaration above specifies that, in
10333 addition to the basic services, we want the OpenSSH secure shell
10334 daemon listening on port 2222 (@pxref{Networking Services,
10335 @code{openssh-service-type}}). Under the hood,
10336 @code{openssh-service-type} arranges so that @command{sshd} is started with the
10337 right command-line options, possibly with supporting configuration files
10338 generated as needed (@pxref{Defining Services}).
10340 @cindex customization, of services
10341 @findex modify-services
10342 Occasionally, instead of using the base services as is, you will want to
10343 customize them. To do this, use @code{modify-services} (@pxref{Service
10344 Reference, @code{modify-services}}) to modify the list.
10346 For example, suppose you want to modify @code{guix-daemon} and Mingetty
10347 (the console log-in) in the @var{%base-services} list (@pxref{Base
10348 Services, @code{%base-services}}). To do that, you can write the
10349 following in your operating system declaration:
10352 (define %my-services
10353 ;; My very own list of services.
10354 (modify-services %base-services
10355 (guix-service-type config =>
10356 (guix-configuration
10358 (use-substitutes? #f)
10359 (extra-options '("--gc-keep-derivations"))))
10360 (mingetty-service-type config =>
10361 (mingetty-configuration
10362 (inherit config)))))
10366 (services %my-services))
10369 This changes the configuration---i.e., the service parameters---of the
10370 @code{guix-service-type} instance, and that of all the
10371 @code{mingetty-service-type} instances in the @var{%base-services} list.
10372 Observe how this is accomplished: first, we arrange for the original
10373 configuration to be bound to the identifier @code{config} in the
10374 @var{body}, and then we write the @var{body} so that it evaluates to the
10375 desired configuration. In particular, notice how we use @code{inherit}
10376 to create a new configuration which has the same values as the old
10377 configuration, but with a few modifications.
10379 @cindex encrypted disk
10380 The configuration for a typical ``desktop'' usage, with an encrypted
10381 root partition, the X11 display
10382 server, GNOME and Xfce (users can choose which of these desktop
10383 environments to use at the log-in screen by pressing @kbd{F1}), network
10384 management, power management, and more, would look like this:
10387 @include os-config-desktop.texi
10390 A graphical system with a choice of lightweight window managers
10391 instead of full-blown desktop environments would look like this:
10394 @include os-config-lightweight-desktop.texi
10397 This example refers to the @file{/boot/efi} file system by its UUID,
10398 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
10399 as returned by the @command{blkid} command.
10401 @xref{Desktop Services}, for the exact list of services provided by
10402 @var{%desktop-services}. @xref{X.509 Certificates}, for background
10403 information about the @code{nss-certs} package that is used here.
10405 Again, @var{%desktop-services} is just a list of service objects. If
10406 you want to remove services from there, you can do so using the
10407 procedures for list filtering (@pxref{SRFI-1 Filtering and
10408 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
10409 following expression returns a list that contains all the services in
10410 @var{%desktop-services} minus the Avahi service:
10413 (remove (lambda (service)
10414 (eq? (service-kind service) avahi-service-type))
10418 @unnumberedsubsec Instantiating the System
10420 Assuming the @code{operating-system} declaration
10421 is stored in the @file{my-system-config.scm}
10422 file, the @command{guix system reconfigure my-system-config.scm} command
10423 instantiates that configuration, and makes it the default GRUB boot
10424 entry (@pxref{Invoking guix system}).
10426 The normal way to change the system configuration is by updating this
10427 file and re-running @command{guix system reconfigure}. One should never
10428 have to touch files in @file{/etc} or to run commands that modify the
10429 system state such as @command{useradd} or @command{grub-install}. In
10430 fact, you must avoid that since that would not only void your warranty
10431 but also prevent you from rolling back to previous versions of your
10432 system, should you ever need to.
10434 @cindex roll-back, of the operating system
10435 Speaking of roll-back, each time you run @command{guix system
10436 reconfigure}, a new @dfn{generation} of the system is created---without
10437 modifying or deleting previous generations. Old system generations get
10438 an entry in the bootloader boot menu, allowing you to boot them in case
10439 something went wrong with the latest generation. Reassuring, no? The
10440 @command{guix system list-generations} command lists the system
10441 generations available on disk. It is also possible to roll back the
10442 system via the commands @command{guix system roll-back} and
10443 @command{guix system switch-generation}.
10445 Although the @command{guix system reconfigure} command will not modify
10446 previous generations, you must take care when the current generation is not
10447 the latest (e.g., after invoking @command{guix system roll-back}), since
10448 the operation might overwrite a later generation (@pxref{Invoking guix
10451 @unnumberedsubsec The Programming Interface
10453 At the Scheme level, the bulk of an @code{operating-system} declaration
10454 is instantiated with the following monadic procedure (@pxref{The Store
10457 @deffn {Monadic Procedure} operating-system-derivation os
10458 Return a derivation that builds @var{os}, an @code{operating-system}
10459 object (@pxref{Derivations}).
10461 The output of the derivation is a single directory that refers to all
10462 the packages, configuration files, and other supporting files needed to
10463 instantiate @var{os}.
10466 This procedure is provided by the @code{(gnu system)} module. Along
10467 with @code{(gnu services)} (@pxref{Services}), this module contains the
10468 guts of Guix System. Make sure to visit it!
10471 @node operating-system Reference
10472 @section @code{operating-system} Reference
10474 This section summarizes all the options available in
10475 @code{operating-system} declarations (@pxref{Using the Configuration
10478 @deftp {Data Type} operating-system
10479 This is the data type representing an operating system configuration.
10480 By that, we mean all the global system configuration, not per-user
10481 configuration (@pxref{Using the Configuration System}).
10484 @item @code{kernel} (default: @var{linux-libre})
10485 The package object of the operating system kernel to use@footnote{Currently
10486 only the Linux-libre kernel is supported. In the future, it will be
10487 possible to use the GNU@tie{}Hurd.}.
10489 @item @code{kernel-arguments} (default: @code{'("quiet")})
10490 List of strings or gexps representing additional arguments to pass on
10491 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
10493 @item @code{bootloader}
10494 The system bootloader configuration object. @xref{Bootloader Configuration}.
10497 This is the label (a string) as it appears in the bootloader's menu entry.
10498 The default label includes the kernel name and version.
10500 @item @code{keyboard-layout} (default: @code{#f})
10501 This field specifies the keyboard layout to use in the console. It can be
10502 either @code{#f}, in which case the default keyboard layout is used (usually
10503 US English), or a @code{<keyboard-layout>} record.
10505 This keyboard layout is in effect as soon as the kernel has booted. For
10506 instance, it is the keyboard layout in effect when you type a passphrase if
10507 your root file system is on a @code{luks-device-mapping} mapped device
10508 (@pxref{Mapped Devices}).
10511 This does @emph{not} specify the keyboard layout used by the bootloader, nor
10512 that used by the graphical display server. @xref{Bootloader Configuration},
10513 for information on how to specify the bootloader's keyboard layout. @xref{X
10514 Window}, for information on how to specify the keyboard layout used by the X
10518 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
10520 @cindex initial RAM disk
10521 The list of Linux kernel modules that need to be available in the
10522 initial RAM disk. @xref{Initial RAM Disk}.
10524 @item @code{initrd} (default: @code{base-initrd})
10525 A procedure that returns an initial RAM disk for the Linux
10526 kernel. This field is provided to support low-level customization and
10527 should rarely be needed for casual use. @xref{Initial RAM Disk}.
10529 @item @code{firmware} (default: @var{%base-firmware})
10531 List of firmware packages loadable by the operating system kernel.
10533 The default includes firmware needed for Atheros- and Broadcom-based
10534 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
10535 respectively). @xref{Hardware Considerations}, for more info on
10536 supported hardware.
10538 @item @code{host-name}
10541 @item @code{hosts-file}
10543 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
10544 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
10545 Reference Manual}). The default is a file with entries for
10546 @code{localhost} and @var{host-name}.
10548 @item @code{mapped-devices} (default: @code{'()})
10549 A list of mapped devices. @xref{Mapped Devices}.
10551 @item @code{file-systems}
10552 A list of file systems. @xref{File Systems}.
10554 @item @code{swap-devices} (default: @code{'()})
10555 @cindex swap devices
10556 A list of strings identifying devices or files to be used for ``swap
10557 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
10558 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
10559 It is possible to specify a swap file in a file system on a mapped
10560 device, provided that the necessary device mapping and file system are
10561 also specified. @xref{Mapped Devices} and @ref{File Systems}.
10563 @item @code{users} (default: @code{%base-user-accounts})
10564 @itemx @code{groups} (default: @var{%base-groups})
10565 List of user accounts and groups. @xref{User Accounts}.
10567 If the @code{users} list lacks a user account with UID@tie{}0, a
10568 ``root'' account with UID@tie{}0 is automatically added.
10570 @item @code{skeletons} (default: @code{(default-skeletons)})
10571 A list target file name/file-like object tuples (@pxref{G-Expressions,
10572 file-like objects}). These are the skeleton files that will be added to
10573 the home directory of newly-created user accounts.
10575 For instance, a valid value may look like this:
10578 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
10579 (".guile" ,(plain-file "guile"
10580 "(use-modules (ice-9 readline))
10581 (activate-readline)")))
10584 @item @code{issue} (default: @var{%default-issue})
10585 A string denoting the contents of the @file{/etc/issue} file, which is
10586 displayed when users log in on a text console.
10588 @item @code{packages} (default: @var{%base-packages})
10589 The set of packages installed in the global profile, which is accessible
10590 at @file{/run/current-system/profile}.
10592 The default set includes core utilities and it is good practice to
10593 install non-core utilities in user profiles (@pxref{Invoking guix
10596 @item @code{timezone}
10597 A timezone identifying string---e.g., @code{"Europe/Paris"}.
10599 You can run the @command{tzselect} command to find out which timezone
10600 string corresponds to your region. Choosing an invalid timezone name
10601 causes @command{guix system} to fail.
10603 @item @code{locale} (default: @code{"en_US.utf8"})
10604 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
10605 Library Reference Manual}). @xref{Locales}, for more information.
10607 @item @code{locale-definitions} (default: @var{%default-locale-definitions})
10608 The list of locale definitions to be compiled and that may be used at
10609 run time. @xref{Locales}.
10611 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
10612 The list of GNU@tie{}libc packages whose locale data and tools are used
10613 to build the locale definitions. @xref{Locales}, for compatibility
10614 considerations that justify this option.
10616 @item @code{name-service-switch} (default: @var{%default-nss})
10617 Configuration of the libc name service switch (NSS)---a
10618 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
10621 @item @code{services} (default: @var{%base-services})
10622 A list of service objects denoting system services. @xref{Services}.
10624 @cindex essential services
10625 @item @code{essential-services} (default: ...)
10626 The list of ``essential services''---i.e., things like instances of
10627 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
10628 Reference}), which are derived from the operating system definition itself.
10629 As a user you should @emph{never} need to touch this field.
10631 @item @code{pam-services} (default: @code{(base-pam-services)})
10633 @cindex pluggable authentication modules
10634 Linux @dfn{pluggable authentication module} (PAM) services.
10635 @c FIXME: Add xref to PAM services section.
10637 @item @code{setuid-programs} (default: @var{%setuid-programs})
10638 List of string-valued G-expressions denoting setuid programs.
10639 @xref{Setuid Programs}.
10641 @item @code{sudoers-file} (default: @var{%sudoers-specification})
10642 @cindex sudoers file
10643 The contents of the @file{/etc/sudoers} file as a file-like object
10644 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
10646 This file specifies which users can use the @command{sudo} command, what
10647 they are allowed to do, and what privileges they may gain. The default
10648 is that only @code{root} and members of the @code{wheel} group may use
10653 @deffn {Scheme Syntax} this-operating-system
10654 When used in the @emph{lexical scope} of an operating system field definition,
10655 this identifier resolves to the operating system being defined.
10657 The example below shows how to refer to the operating system being defined in
10658 the definition of the @code{label} field:
10661 (use-modules (gnu) (guix))
10665 (label (package-full-name
10666 (operating-system-kernel this-operating-system))))
10669 It is an error to refer to @code{this-operating-system} outside an operating
10676 @section File Systems
10678 The list of file systems to be mounted is specified in the
10679 @code{file-systems} field of the operating system declaration
10680 (@pxref{Using the Configuration System}). Each file system is declared
10681 using the @code{file-system} form, like this:
10685 (mount-point "/home")
10686 (device "/dev/sda3")
10690 As usual, some of the fields are mandatory---those shown in the example
10691 above---while others can be omitted. These are described below.
10693 @deftp {Data Type} file-system
10694 Objects of this type represent file systems to be mounted. They
10695 contain the following members:
10699 This is a string specifying the type of the file system---e.g.,
10702 @item @code{mount-point}
10703 This designates the place where the file system is to be mounted.
10705 @item @code{device}
10706 This names the ``source'' of the file system. It can be one of three
10707 things: a file system label, a file system UUID, or the name of a
10708 @file{/dev} node. Labels and UUIDs offer a way to refer to file
10709 systems without having to hard-code their actual device
10710 name@footnote{Note that, while it is tempting to use
10711 @file{/dev/disk/by-uuid} and similar device names to achieve the same
10712 result, this is not recommended: These special device nodes are created
10713 by the udev daemon and may be unavailable at the time the device is
10716 @findex file-system-label
10717 File system labels are created using the @code{file-system-label}
10718 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
10719 plain strings. Here's an example of a file system referred to by its
10720 label, as shown by the @command{e2label} command:
10724 (mount-point "/home")
10726 (device (file-system-label "my-home")))
10730 UUIDs are converted from their string representation (as shown by the
10731 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
10732 @code{uuid} form expects 16-byte UUIDs as defined in
10733 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
10734 form of UUID used by the ext2 family of file systems and others, but it
10735 is different from ``UUIDs'' found in FAT file systems, for instance.},
10740 (mount-point "/home")
10742 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
10745 When the source of a file system is a mapped device (@pxref{Mapped
10746 Devices}), its @code{device} field @emph{must} refer to the mapped
10747 device name---e.g., @file{"/dev/mapper/root-partition"}.
10748 This is required so that
10749 the system knows that mounting the file system depends on having the
10750 corresponding device mapping established.
10752 @item @code{flags} (default: @code{'()})
10753 This is a list of symbols denoting mount flags. Recognized flags
10754 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
10755 access to special files), @code{no-suid} (ignore setuid and setgid
10756 bits), @code{no-atime} (do not update file access times), and @code{no-exec}
10757 (disallow program execution). @xref{Mount-Unmount-Remount,,, libc, The GNU C
10758 Library Reference Manual}, for more information on these flags.
10760 @item @code{options} (default: @code{#f})
10761 This is either @code{#f}, or a string denoting mount options passed to the
10762 file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
10763 Reference Manual}, for details and run @command{man 8 mount} for options for
10764 various file systems.
10766 @item @code{mount?} (default: @code{#t})
10767 This value indicates whether to automatically mount the file system when
10768 the system is brought up. When set to @code{#f}, the file system gets
10769 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
10770 is not automatically mounted.
10772 @item @code{needed-for-boot?} (default: @code{#f})
10773 This Boolean value indicates whether the file system is needed when
10774 booting. If that is true, then the file system is mounted when the
10775 initial RAM disk (initrd) is loaded. This is always the case, for
10776 instance, for the root file system.
10778 @item @code{check?} (default: @code{#t})
10779 This Boolean indicates whether the file system needs to be checked for
10780 errors before being mounted.
10782 @item @code{create-mount-point?} (default: @code{#f})
10783 When true, the mount point is created if it does not exist yet.
10785 @item @code{dependencies} (default: @code{'()})
10786 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
10787 representing file systems that must be mounted or mapped devices that
10788 must be opened before (and unmounted or closed after) this one.
10790 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
10791 a dependency of @file{/sys/fs/cgroup/cpu} and
10792 @file{/sys/fs/cgroup/memory}.
10794 Another example is a file system that depends on a mapped device, for
10795 example for an encrypted partition (@pxref{Mapped Devices}).
10799 The @code{(gnu system file-systems)} exports the following useful
10802 @defvr {Scheme Variable} %base-file-systems
10803 These are essential file systems that are required on normal systems,
10804 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
10805 below.) Operating system declarations should always contain at least
10809 @defvr {Scheme Variable} %pseudo-terminal-file-system
10810 This is the file system to be mounted as @file{/dev/pts}. It supports
10811 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
10812 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
10813 Manual}). Pseudo-terminals are used by terminal emulators such as
10817 @defvr {Scheme Variable} %shared-memory-file-system
10818 This file system is mounted as @file{/dev/shm} and is used to support
10819 memory sharing across processes (@pxref{Memory-mapped I/O,
10820 @code{shm_open},, libc, The GNU C Library Reference Manual}).
10823 @defvr {Scheme Variable} %immutable-store
10824 This file system performs a read-only ``bind mount'' of
10825 @file{/gnu/store}, making it read-only for all the users including
10826 @code{root}. This prevents against accidental modification by software
10827 running as @code{root} or by system administrators.
10829 The daemon itself is still able to write to the store: it remounts it
10830 read-write in its own ``name space.''
10833 @defvr {Scheme Variable} %binary-format-file-system
10834 The @code{binfmt_misc} file system, which allows handling of arbitrary
10835 executable file types to be delegated to user space. This requires the
10836 @code{binfmt.ko} kernel module to be loaded.
10839 @defvr {Scheme Variable} %fuse-control-file-system
10840 The @code{fusectl} file system, which allows unprivileged users to mount
10841 and unmount user-space FUSE file systems. This requires the
10842 @code{fuse.ko} kernel module to be loaded.
10845 @node Mapped Devices
10846 @section Mapped Devices
10848 @cindex device mapping
10849 @cindex mapped devices
10850 The Linux kernel has a notion of @dfn{device mapping}: a block device,
10851 such as a hard disk partition, can be @dfn{mapped} into another device,
10852 usually in @code{/dev/mapper/},
10853 with additional processing over the data that flows through
10854 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
10855 concept of a ``mapped device'' and that of a file system: both boil down
10856 to @emph{translating} input/output operations made on a file to
10857 operations on its backing store. Thus, the Hurd implements mapped
10858 devices, like file systems, using the generic @dfn{translator} mechanism
10859 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
10860 typical example is encryption device mapping: all writes to the mapped
10861 device are encrypted, and all reads are deciphered, transparently.
10862 Guix extends this notion by considering any device or set of devices that
10863 are @dfn{transformed} in some way to create a new device; for instance,
10864 RAID devices are obtained by @dfn{assembling} several other devices, such
10865 as hard disks or partitions, into a new one that behaves as one partition.
10866 Other examples, not yet implemented, are LVM logical volumes.
10868 Mapped devices are declared using the @code{mapped-device} form,
10869 defined as follows; for examples, see below.
10871 @deftp {Data Type} mapped-device
10872 Objects of this type represent device mappings that will be made when
10873 the system boots up.
10877 This is either a string specifying the name of the block device to be mapped,
10878 such as @code{"/dev/sda3"}, or a list of such strings when several devices
10879 need to be assembled for creating a new one.
10882 This string specifies the name of the resulting mapped device. For
10883 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
10884 specifying @code{"my-partition"} leads to the creation of
10885 the @code{"/dev/mapper/my-partition"} device.
10886 For RAID devices of type @code{raid-device-mapping}, the full device name
10887 such as @code{"/dev/md0"} needs to be given.
10890 This must be a @code{mapped-device-kind} object, which specifies how
10891 @var{source} is mapped to @var{target}.
10895 @defvr {Scheme Variable} luks-device-mapping
10896 This defines LUKS block device encryption using the @command{cryptsetup}
10897 command from the package with the same name. It relies on the
10898 @code{dm-crypt} Linux kernel module.
10901 @defvr {Scheme Variable} raid-device-mapping
10902 This defines a RAID device, which is assembled using the @code{mdadm}
10903 command from the package with the same name. It requires a Linux kernel
10904 module for the appropriate RAID level to be loaded, such as @code{raid456}
10905 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
10908 @cindex disk encryption
10910 The following example specifies a mapping from @file{/dev/sda3} to
10911 @file{/dev/mapper/home} using LUKS---the
10912 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
10913 standard mechanism for disk encryption.
10914 The @file{/dev/mapper/home}
10915 device can then be used as the @code{device} of a @code{file-system}
10916 declaration (@pxref{File Systems}).
10920 (source "/dev/sda3")
10922 (type luks-device-mapping))
10925 Alternatively, to become independent of device numbering, one may obtain
10926 the LUKS UUID (@dfn{unique identifier}) of the source device by a
10930 cryptsetup luksUUID /dev/sda3
10933 and use it as follows:
10937 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
10939 (type luks-device-mapping))
10942 @cindex swap encryption
10943 It is also desirable to encrypt swap space, since swap space may contain
10944 sensitive data. One way to accomplish that is to use a swap file in a
10945 file system on a device mapped via LUKS encryption. In this way, the
10946 swap file is encrypted because the entire device is encrypted.
10947 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
10949 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
10950 may be declared as follows:
10954 (source (list "/dev/sda1" "/dev/sdb1"))
10955 (target "/dev/md0")
10956 (type raid-device-mapping))
10959 The @file{/dev/md0} device can then be used as the @code{device} of a
10960 @code{file-system} declaration (@pxref{File Systems}).
10961 Note that the RAID level need not be given; it is chosen during the
10962 initial creation and formatting of the RAID device and is determined
10963 automatically later.
10966 @node User Accounts
10967 @section User Accounts
10971 @cindex user accounts
10972 User accounts and groups are entirely managed through the
10973 @code{operating-system} declaration. They are specified with the
10974 @code{user-account} and @code{user-group} forms:
10980 (supplementary-groups '("wheel" ;allow use of sudo, etc.
10981 "audio" ;sound card
10982 "video" ;video devices such as webcams
10983 "cdrom")) ;the good ol' CD-ROM
10984 (comment "Bob's sister")
10985 (home-directory "/home/alice"))
10988 When booting or upon completion of @command{guix system reconfigure},
10989 the system ensures that only the user accounts and groups specified in
10990 the @code{operating-system} declaration exist, and with the specified
10991 properties. Thus, account or group creations or modifications made by
10992 directly invoking commands such as @command{useradd} are lost upon
10993 reconfiguration or reboot. This ensures that the system remains exactly
10996 @deftp {Data Type} user-account
10997 Objects of this type represent user accounts. The following members may
11002 The name of the user account.
11006 This is the name (a string) or identifier (a number) of the user group
11007 this account belongs to.
11009 @item @code{supplementary-groups} (default: @code{'()})
11010 Optionally, this can be defined as a list of group names that this
11011 account belongs to.
11013 @item @code{uid} (default: @code{#f})
11014 This is the user ID for this account (a number), or @code{#f}. In the
11015 latter case, a number is automatically chosen by the system when the
11016 account is created.
11018 @item @code{comment} (default: @code{""})
11019 A comment about the account, such as the account owner's full name.
11021 @item @code{home-directory}
11022 This is the name of the home directory for the account.
11024 @item @code{create-home-directory?} (default: @code{#t})
11025 Indicates whether the home directory of this account should be created
11026 if it does not exist yet.
11028 @item @code{shell} (default: Bash)
11029 This is a G-expression denoting the file name of a program to be used as
11030 the shell (@pxref{G-Expressions}).
11032 @item @code{system?} (default: @code{#f})
11033 This Boolean value indicates whether the account is a ``system''
11034 account. System accounts are sometimes treated specially; for instance,
11035 graphical login managers do not list them.
11037 @anchor{user-account-password}
11038 @cindex password, for user accounts
11039 @item @code{password} (default: @code{#f})
11040 You would normally leave this field to @code{#f}, initialize user
11041 passwords as @code{root} with the @command{passwd} command, and then let
11042 users change it with @command{passwd}. Passwords set with
11043 @command{passwd} are of course preserved across reboot and
11046 If you @emph{do} want to set an initial password for an account, then
11047 this field must contain the encrypted password, as a string. You can use the
11048 @code{crypt} procedure for this purpose:
11055 ;; Specify a SHA-512-hashed initial password.
11056 (password (crypt "InitialPassword!" "$6$abc")))
11060 The hash of this initial password will be available in a file in
11061 @file{/gnu/store}, readable by all the users, so this method must be used with
11065 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
11066 more information on password encryption, and @ref{Encryption,,, guile, GNU
11067 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
11073 User group declarations are even simpler:
11076 (user-group (name "students"))
11079 @deftp {Data Type} user-group
11080 This type is for, well, user groups. There are just a few fields:
11084 The name of the group.
11086 @item @code{id} (default: @code{#f})
11087 The group identifier (a number). If @code{#f}, a new number is
11088 automatically allocated when the group is created.
11090 @item @code{system?} (default: @code{#f})
11091 This Boolean value indicates whether the group is a ``system'' group.
11092 System groups have low numerical IDs.
11094 @item @code{password} (default: @code{#f})
11095 What, user groups can have a password? Well, apparently yes. Unless
11096 @code{#f}, this field specifies the password of the group.
11101 For convenience, a variable lists all the basic user groups one may
11104 @defvr {Scheme Variable} %base-groups
11105 This is the list of basic user groups that users and/or packages expect
11106 to be present on the system. This includes groups such as ``root'',
11107 ``wheel'', and ``users'', as well as groups used to control access to
11108 specific devices such as ``audio'', ``disk'', and ``cdrom''.
11111 @defvr {Scheme Variable} %base-user-accounts
11112 This is the list of basic system accounts that programs may expect to
11113 find on a GNU/Linux system, such as the ``nobody'' account.
11115 Note that the ``root'' account is not included here. It is a
11116 special-case and is automatically added whether or not it is specified.
11119 @node Keyboard Layout
11120 @section Keyboard Layout
11122 @cindex keyboard layout
11124 To specify what each key of your keyboard does, you need to tell the operating
11125 system what @dfn{keyboard layout} you want to use. The default, when nothing
11126 is specified, is the US English QWERTY layout for 105-key PC keyboards.
11127 However, German speakers will usually prefer the German QWERTZ layout, French
11128 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
11129 or bépo, and they might even want to further customize the effect of some of
11130 the keys. This section explains how to get that done.
11132 @cindex keyboard layout, definition
11133 There are three components that will want to know about your keyboard layout:
11137 The @emph{bootloader} may want to know what keyboard layout you want to use
11138 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
11139 you want, for instance, to make sure that you can type the passphrase of your
11140 encrypted root partition using the right layout.
11143 The @emph{operating system kernel}, Linux, will need that so that the console
11144 is properly configured (@pxref{operating-system Reference,
11145 @code{keyboard-layout}}).
11148 The @emph{graphical display server}, usually Xorg, also has its own idea of
11149 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
11152 Guix allows you to configure all three separately but, fortunately, it allows
11153 you to share the same keyboard layout for all three components.
11155 @cindex XKB, keyboard layouts
11156 Keyboard layouts are represented by records created by the
11157 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
11158 the X Keyboard extension (XKB), each layout has four attributes: a name (often
11159 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
11160 optional variant name, an optional keyboard model name, and a possibly empty
11161 list of additional options. In most cases the layout name is all you care
11162 about. Here are a few example:
11165 ;; The German QWERTZ layout. Here we assume a standard
11166 ;; "pc105" keyboard model.
11167 (keyboard-layout "de")
11169 ;; The bépo variant of the French layout.
11170 (keyboard-layout "fr" "bepo")
11172 ;; The Catalan layout.
11173 (keyboard-layout "es" "cat")
11175 ;; The Latin American Spanish layout. In addition, the
11176 ;; "Caps Lock" key is used as an additional "Ctrl" key,
11177 ;; and the "Menu" key is used as a "Compose" key to enter
11178 ;; accented letters.
11179 (keyboard-layout "latam"
11180 #:options '("ctrl:nocaps" "compose:menu"))
11182 ;; The Russian layout for a ThinkPad keyboard.
11183 (keyboard-layout "ru" #:model "thinkpad")
11185 ;; The "US international" layout, which is the US layout plus
11186 ;; dead keys to enter accented characters. This is for an
11187 ;; Apple MacBook keyboard.
11188 (keyboard-layout "us" "intl" #:model "macbook78")
11191 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
11192 for a complete list of supported layouts, variants, and models.
11194 @cindex keyboard layout, configuration
11195 Let's say you want your system to use the Turkish keyboard layout throughout
11196 your system---bootloader, console, and Xorg. Here's what your system
11197 configuration would look like:
11199 @findex set-xorg-configuration
11201 ;; Using the Turkish layout for the bootloader, the console,
11206 (keyboard-layout (keyboard-layout "tr")) ;for the console
11207 (bootloader (bootloader-configuration
11208 (bootloader grub-efi-bootloader)
11209 (target "/boot/efi")
11210 (keyboard-layout keyboard-layout))) ;for GRUB
11211 (services (cons (set-xorg-configuration
11212 (xorg-configuration ;for Xorg
11213 (keyboard-layout keyboard-layout)))
11214 %desktop-services)))
11217 In the example above, for GRUB and for Xorg, we just refer to the
11218 @code{keyboard-layout} field defined above, but we could just as well refer to
11219 a different layout. The @code{set-xorg-configuration} procedure communicates
11220 the desired Xorg configuration to the graphical log-in manager, by default
11223 We've discussed how to specify the @emph{default} keyboard layout of your
11224 system when it starts, but you can also adjust it at run time:
11228 If you're using GNOME, its settings panel has a ``Region & Language'' entry
11229 where you can select one or more keyboard layouts.
11232 Under Xorg, the @command{setxkbmap} command (from the same-named package)
11233 allows you to change the current layout. For example, this is how you would
11234 change the layout to US Dvorak:
11237 setxkbmap us dvorak
11241 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
11242 console. However, note that @code{loadkeys} does @emph{not} use the XKB
11243 keyboard layout categorization described above. The command below loads the
11244 French bépo layout:
11255 A @dfn{locale} defines cultural conventions for a particular language
11256 and region of the world (@pxref{Locales,,, libc, The GNU C Library
11257 Reference Manual}). Each locale has a name that typically has the form
11258 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
11259 @code{fr_LU.utf8} designates the locale for the French language, with
11260 cultural conventions from Luxembourg, and using the UTF-8 encoding.
11262 @cindex locale definition
11263 Usually, you will want to specify the default locale for the machine
11264 using the @code{locale} field of the @code{operating-system} declaration
11265 (@pxref{operating-system Reference, @code{locale}}).
11267 The selected locale is automatically added to the @dfn{locale
11268 definitions} known to the system if needed, with its codeset inferred
11269 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
11270 @code{UTF-8} codeset. Additional locale definitions can be specified in
11271 the @code{locale-definitions} slot of @code{operating-system}---this is
11272 useful, for instance, if the codeset could not be inferred from the
11273 locale name. The default set of locale definitions includes some widely
11274 used locales, but not all the available locales, in order to save space.
11276 For instance, to add the North Frisian locale for Germany, the value of
11280 (cons (locale-definition
11281 (name "fy_DE.utf8") (source "fy_DE"))
11282 %default-locale-definitions)
11285 Likewise, to save space, one might want @code{locale-definitions} to
11286 list only the locales that are actually used, as in:
11289 (list (locale-definition
11290 (name "ja_JP.eucjp") (source "ja_JP")
11291 (charset "EUC-JP")))
11295 The compiled locale definitions are available at
11296 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
11297 version, which is the default location where the GNU@tie{}libc provided
11298 by Guix looks for locale data. This can be overridden using the
11299 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
11300 @code{LOCPATH} and locale packages}).
11302 The @code{locale-definition} form is provided by the @code{(gnu system
11303 locale)} module. Details are given below.
11305 @deftp {Data Type} locale-definition
11306 This is the data type of a locale definition.
11311 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
11312 Reference Manual}, for more information on locale names.
11314 @item @code{source}
11315 The name of the source for that locale. This is typically the
11316 @code{@var{language}_@var{territory}} part of the locale name.
11318 @item @code{charset} (default: @code{"UTF-8"})
11319 The ``character set'' or ``code set'' for that locale,
11320 @uref{http://www.iana.org/assignments/character-sets, as defined by
11326 @defvr {Scheme Variable} %default-locale-definitions
11327 A list of commonly used UTF-8 locales, used as the default
11328 value of the @code{locale-definitions} field of @code{operating-system}
11331 @cindex locale name
11332 @cindex normalized codeset in locale names
11333 These locale definitions use the @dfn{normalized codeset} for the part
11334 that follows the dot in the name (@pxref{Using gettextized software,
11335 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
11336 instance it has @code{uk_UA.utf8} but @emph{not}, say,
11337 @code{uk_UA.UTF-8}.
11340 @subsection Locale Data Compatibility Considerations
11342 @cindex incompatibility, of locale data
11343 @code{operating-system} declarations provide a @code{locale-libcs} field
11344 to specify the GNU@tie{}libc packages that are used to compile locale
11345 declarations (@pxref{operating-system Reference}). ``Why would I
11346 care?'', you may ask. Well, it turns out that the binary format of
11347 locale data is occasionally incompatible from one libc version to
11350 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
11351 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
11352 For instance, a program linked against libc version 2.21 is unable to
11353 read locale data produced with libc 2.22; worse, that program
11354 @emph{aborts} instead of simply ignoring the incompatible locale
11355 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
11356 the incompatible locale data, which is already an improvement.}.
11357 Similarly, a program linked against libc 2.22 can read most, but not
11358 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
11359 data is incompatible); thus calls to @code{setlocale} may fail, but
11360 programs will not abort.
11362 The ``problem'' with Guix is that users have a lot of freedom: They can
11363 choose whether and when to upgrade software in their profiles, and might
11364 be using a libc version different from the one the system administrator
11365 used to build the system-wide locale data.
11367 Fortunately, unprivileged users can also install their own locale data
11368 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
11369 @code{GUIX_LOCPATH} and locale packages}).
11371 Still, it is best if the system-wide locale data at
11372 @file{/run/current-system/locale} is built for all the libc versions
11373 actually in use on the system, so that all the programs can access
11374 it---this is especially crucial on a multi-user system. To do that, the
11375 administrator can specify several libc packages in the
11376 @code{locale-libcs} field of @code{operating-system}:
11379 (use-package-modules base)
11383 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
11386 This example would lead to a system containing locale definitions for
11387 both libc 2.21 and the current version of libc in
11388 @file{/run/current-system/locale}.
11394 @cindex system services
11395 An important part of preparing an @code{operating-system} declaration is
11396 listing @dfn{system services} and their configuration (@pxref{Using the
11397 Configuration System}). System services are typically daemons launched
11398 when the system boots, or other actions needed at that time---e.g.,
11399 configuring network access.
11401 Guix has a broad definition of ``service'' (@pxref{Service
11402 Composition}), but many services are managed by the GNU@tie{}Shepherd
11403 (@pxref{Shepherd Services}). On a running system, the @command{herd}
11404 command allows you to list the available services, show their status,
11405 start and stop them, or do other specific operations (@pxref{Jump
11406 Start,,, shepherd, The GNU Shepherd Manual}). For example:
11412 The above command, run as @code{root}, lists the currently defined
11413 services. The @command{herd doc} command shows a synopsis of the given
11414 service and its associated actions:
11418 Run libc's name service cache daemon (nscd).
11420 # herd doc nscd action invalidate
11421 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
11424 The @command{start}, @command{stop}, and @command{restart} sub-commands
11425 have the effect you would expect. For instance, the commands below stop
11426 the nscd service and restart the Xorg display server:
11430 Service nscd has been stopped.
11431 # herd restart xorg-server
11432 Service xorg-server has been stopped.
11433 Service xorg-server has been started.
11436 The following sections document the available services, starting with
11437 the core services, that may be used in an @code{operating-system}
11441 * Base Services:: Essential system services.
11442 * Scheduled Job Execution:: The mcron service.
11443 * Log Rotation:: The rottlog service.
11444 * Networking Services:: Network setup, SSH daemon, etc.
11445 * X Window:: Graphical display.
11446 * Printing Services:: Local and remote printer support.
11447 * Desktop Services:: D-Bus and desktop services.
11448 * Sound Services:: ALSA and Pulseaudio services.
11449 * Database Services:: SQL databases, key-value stores, etc.
11450 * Mail Services:: IMAP, POP3, SMTP, and all that.
11451 * Messaging Services:: Messaging services.
11452 * Telephony Services:: Telephony services.
11453 * Monitoring Services:: Monitoring services.
11454 * Kerberos Services:: Kerberos services.
11455 * LDAP Services:: LDAP services.
11456 * Web Services:: Web servers.
11457 * Certificate Services:: TLS certificates via Let's Encrypt.
11458 * DNS Services:: DNS daemons.
11459 * VPN Services:: VPN daemons.
11460 * Network File System:: NFS related services.
11461 * Continuous Integration:: The Cuirass service.
11462 * Power Management Services:: Extending battery life.
11463 * Audio Services:: The MPD.
11464 * Virtualization Services:: Virtualization services.
11465 * Version Control Services:: Providing remote access to Git repositories.
11466 * Game Services:: Game servers.
11467 * Miscellaneous Services:: Other services.
11470 @node Base Services
11471 @subsection Base Services
11473 The @code{(gnu services base)} module provides definitions for the basic
11474 services that one expects from the system. The services exported by
11475 this module are listed below.
11477 @defvr {Scheme Variable} %base-services
11478 This variable contains a list of basic services (@pxref{Service Types
11479 and Services}, for more information on service objects) one would
11480 expect from the system: a login service (mingetty) on each tty, syslogd,
11481 the libc name service cache daemon (nscd), the udev device manager, and
11484 This is the default value of the @code{services} field of
11485 @code{operating-system} declarations. Usually, when customizing a
11486 system, you will want to append services to @var{%base-services}, like
11490 (append (list (service avahi-service-type)
11491 (service openssh-service-type))
11496 @defvr {Scheme Variable} special-files-service-type
11497 This is the service that sets up ``special files'' such as
11498 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
11500 The value associated with @code{special-files-service-type} services
11501 must be a list of tuples where the first element is the ``special file''
11502 and the second element is its target. By default it is:
11504 @cindex @file{/bin/sh}
11505 @cindex @file{sh}, in @file{/bin}
11507 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
11510 @cindex @file{/usr/bin/env}
11511 @cindex @file{env}, in @file{/usr/bin}
11512 If you want to add, say, @code{/usr/bin/env} to your system, you can
11516 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
11517 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
11520 Since this is part of @code{%base-services}, you can use
11521 @code{modify-services} to customize the set of special files
11522 (@pxref{Service Reference, @code{modify-services}}). But the simple way
11523 to add a special file is @i{via} the @code{extra-special-file} procedure
11527 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
11528 Use @var{target} as the ``special file'' @var{file}.
11530 For example, adding the following lines to the @code{services} field of
11531 your operating system declaration leads to a @file{/usr/bin/env}
11535 (extra-special-file "/usr/bin/env"
11536 (file-append coreutils "/bin/env"))
11540 @deffn {Scheme Procedure} host-name-service @var{name}
11541 Return a service that sets the host name to @var{name}.
11544 @deffn {Scheme Procedure} login-service @var{config}
11545 Return a service to run login according to @var{config}, a
11546 @code{<login-configuration>} object, which specifies the message of the day,
11547 among other things.
11550 @deftp {Data Type} login-configuration
11551 This is the data type representing the configuration of login.
11556 @cindex message of the day
11557 A file-like object containing the ``message of the day''.
11559 @item @code{allow-empty-passwords?} (default: @code{#t})
11560 Allow empty passwords by default so that first-time users can log in when
11561 the 'root' account has just been created.
11566 @deffn {Scheme Procedure} mingetty-service @var{config}
11567 Return a service to run mingetty according to @var{config}, a
11568 @code{<mingetty-configuration>} object, which specifies the tty to run, among
11572 @deftp {Data Type} mingetty-configuration
11573 This is the data type representing the configuration of Mingetty, which
11574 provides the default implementation of virtual console log-in.
11579 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
11581 @item @code{auto-login} (default: @code{#f})
11582 When true, this field must be a string denoting the user name under
11583 which the system automatically logs in. When it is @code{#f}, a
11584 user name and password must be entered to log in.
11586 @item @code{login-program} (default: @code{#f})
11587 This must be either @code{#f}, in which case the default log-in program
11588 is used (@command{login} from the Shadow tool suite), or a gexp denoting
11589 the name of the log-in program.
11591 @item @code{login-pause?} (default: @code{#f})
11592 When set to @code{#t} in conjunction with @var{auto-login}, the user
11593 will have to press a key before the log-in shell is launched.
11595 @item @code{mingetty} (default: @var{mingetty})
11596 The Mingetty package to use.
11601 @deffn {Scheme Procedure} agetty-service @var{config}
11602 Return a service to run agetty according to @var{config}, an
11603 @code{<agetty-configuration>} object, which specifies the tty to run,
11604 among other things.
11607 @deftp {Data Type} agetty-configuration
11608 This is the data type representing the configuration of agetty, which
11609 implements virtual and serial console log-in. See the @code{agetty(8)}
11610 man page for more information.
11615 The name of the console this agetty runs on, as a string---e.g.,
11616 @code{"ttyS0"}. This argument is optional, it will default to
11617 a reasonable default serial port used by the kernel Linux.
11619 For this, if there is a value for an option @code{agetty.tty} in the kernel
11620 command line, agetty will extract the device name of the serial port
11621 from it and use that.
11623 If not and if there is a value for an option @code{console} with a tty in
11624 the Linux command line, agetty will extract the device name of the
11625 serial port from it and use that.
11627 In both cases, agetty will leave the other serial device settings
11628 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
11631 @item @code{baud-rate} (default: @code{#f})
11632 A string containing a comma-separated list of one or more baud rates, in
11635 @item @code{term} (default: @code{#f})
11636 A string containing the value used for the @code{TERM} environment
11639 @item @code{eight-bits?} (default: @code{#f})
11640 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
11643 @item @code{auto-login} (default: @code{#f})
11644 When passed a login name, as a string, the specified user will be logged
11645 in automatically without prompting for their login name or password.
11647 @item @code{no-reset?} (default: @code{#f})
11648 When @code{#t}, don't reset terminal cflags (control modes).
11650 @item @code{host} (default: @code{#f})
11651 This accepts a string containing the "login_host", which will be written
11652 into the @file{/var/run/utmpx} file.
11654 @item @code{remote?} (default: @code{#f})
11655 When set to @code{#t} in conjunction with @var{host}, this will add an
11656 @code{-r} fakehost option to the command line of the login program
11657 specified in @var{login-program}.
11659 @item @code{flow-control?} (default: @code{#f})
11660 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
11662 @item @code{no-issue?} (default: @code{#f})
11663 When set to @code{#t}, the contents of the @file{/etc/issue} file will
11664 not be displayed before presenting the login prompt.
11666 @item @code{init-string} (default: @code{#f})
11667 This accepts a string that will be sent to the tty or modem before
11668 sending anything else. It can be used to initialize a modem.
11670 @item @code{no-clear?} (default: @code{#f})
11671 When set to @code{#t}, agetty will not clear the screen before showing
11674 @item @code{login-program} (default: (file-append shadow "/bin/login"))
11675 This must be either a gexp denoting the name of a log-in program, or
11676 unset, in which case the default value is the @command{login} from the
11679 @item @code{local-line} (default: @code{#f})
11680 Control the CLOCAL line flag. This accepts one of three symbols as
11681 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
11682 the default value chosen by agetty is @code{'auto}.
11684 @item @code{extract-baud?} (default: @code{#f})
11685 When set to @code{#t}, instruct agetty to try to extract the baud rate
11686 from the status messages produced by certain types of modems.
11688 @item @code{skip-login?} (default: @code{#f})
11689 When set to @code{#t}, do not prompt the user for a login name. This
11690 can be used with @var{login-program} field to use non-standard login
11693 @item @code{no-newline?} (default: @code{#f})
11694 When set to @code{#t}, do not print a newline before printing the
11695 @file{/etc/issue} file.
11697 @c Is this dangerous only when used with login-program, or always?
11698 @item @code{login-options} (default: @code{#f})
11699 This option accepts a string containing options that are passed to the
11700 login program. When used with the @var{login-program}, be aware that a
11701 malicious user could try to enter a login name containing embedded
11702 options that could be parsed by the login program.
11704 @item @code{login-pause} (default: @code{#f})
11705 When set to @code{#t}, wait for any key before showing the login prompt.
11706 This can be used in conjunction with @var{auto-login} to save memory by
11707 lazily spawning shells.
11709 @item @code{chroot} (default: @code{#f})
11710 Change root to the specified directory. This option accepts a directory
11713 @item @code{hangup?} (default: @code{#f})
11714 Use the Linux system call @code{vhangup} to do a virtual hangup of the
11715 specified terminal.
11717 @item @code{keep-baud?} (default: @code{#f})
11718 When set to @code{#t}, try to keep the existing baud rate. The baud
11719 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
11722 @item @code{timeout} (default: @code{#f})
11723 When set to an integer value, terminate if no user name could be read
11724 within @var{timeout} seconds.
11726 @item @code{detect-case?} (default: @code{#f})
11727 When set to @code{#t}, turn on support for detecting an uppercase-only
11728 terminal. This setting will detect a login name containing only
11729 uppercase letters as indicating an uppercase-only terminal and turn on
11730 some upper-to-lower case conversions. Note that this will not support
11731 Unicode characters.
11733 @item @code{wait-cr?} (default: @code{#f})
11734 When set to @code{#t}, wait for the user or modem to send a
11735 carriage-return or linefeed character before displaying
11736 @file{/etc/issue} or login prompt. This is typically used with the
11737 @var{init-string} option.
11739 @item @code{no-hints?} (default: @code{#f})
11740 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
11743 @item @code{no-hostname?} (default: @code{#f})
11744 By default, the hostname is printed. When this option is set to
11745 @code{#t}, no hostname will be shown at all.
11747 @item @code{long-hostname?} (default: @code{#f})
11748 By default, the hostname is only printed until the first dot. When this
11749 option is set to @code{#t}, the fully qualified hostname by
11750 @code{gethostname} or @code{getaddrinfo} is shown.
11752 @item @code{erase-characters} (default: @code{#f})
11753 This option accepts a string of additional characters that should be
11754 interpreted as backspace when the user types their login name.
11756 @item @code{kill-characters} (default: @code{#f})
11757 This option accepts a string that should be interpreted to mean "ignore
11758 all previous characters" (also called a "kill" character) when the types
11761 @item @code{chdir} (default: @code{#f})
11762 This option accepts, as a string, a directory path that will be changed
11765 @item @code{delay} (default: @code{#f})
11766 This options accepts, as an integer, the number of seconds to sleep
11767 before opening the tty and displaying the login prompt.
11769 @item @code{nice} (default: @code{#f})
11770 This option accepts, as an integer, the nice value with which to run the
11771 @command{login} program.
11773 @item @code{extra-options} (default: @code{'()})
11774 This option provides an "escape hatch" for the user to provide arbitrary
11775 command-line arguments to @command{agetty} as a list of strings.
11780 @deffn {Scheme Procedure} kmscon-service-type @var{config}
11781 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
11782 according to @var{config}, a @code{<kmscon-configuration>} object, which
11783 specifies the tty to run, among other things.
11786 @deftp {Data Type} kmscon-configuration
11787 This is the data type representing the configuration of Kmscon, which
11788 implements virtual console log-in.
11792 @item @code{virtual-terminal}
11793 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
11795 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
11796 A gexp denoting the name of the log-in program. The default log-in program is
11797 @command{login} from the Shadow tool suite.
11799 @item @code{login-arguments} (default: @code{'("-p")})
11800 A list of arguments to pass to @command{login}.
11802 @item @code{auto-login} (default: @code{#f})
11803 When passed a login name, as a string, the specified user will be logged
11804 in automatically without prompting for their login name or password.
11806 @item @code{hardware-acceleration?} (default: #f)
11807 Whether to use hardware acceleration.
11809 @item @code{kmscon} (default: @var{kmscon})
11810 The Kmscon package to use.
11815 @cindex name service cache daemon
11817 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
11818 [#:name-services '()]
11819 Return a service that runs the libc name service cache daemon (nscd) with the
11820 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
11821 Service Switch}, for an example.
11823 For convenience, the Shepherd service for nscd provides the following actions:
11827 @cindex cache invalidation, nscd
11828 @cindex nscd, cache invalidation
11829 This invalidate the given cache. For instance, running:
11832 herd invalidate nscd hosts
11836 invalidates the host name lookup cache of nscd.
11839 Running @command{herd statistics nscd} displays information about nscd usage
11845 @defvr {Scheme Variable} %nscd-default-configuration
11846 This is the default @code{<nscd-configuration>} value (see below) used
11847 by @code{nscd-service}. It uses the caches defined by
11848 @var{%nscd-default-caches}; see below.
11851 @deftp {Data Type} nscd-configuration
11852 This is the data type representing the name service cache daemon (nscd)
11857 @item @code{name-services} (default: @code{'()})
11858 List of packages denoting @dfn{name services} that must be visible to
11859 the nscd---e.g., @code{(list @var{nss-mdns})}.
11861 @item @code{glibc} (default: @var{glibc})
11862 Package object denoting the GNU C Library providing the @command{nscd}
11865 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
11866 Name of the nscd log file. This is where debugging output goes when
11867 @code{debug-level} is strictly positive.
11869 @item @code{debug-level} (default: @code{0})
11870 Integer denoting the debugging levels. Higher numbers mean that more
11871 debugging output is logged.
11873 @item @code{caches} (default: @var{%nscd-default-caches})
11874 List of @code{<nscd-cache>} objects denoting things to be cached; see
11880 @deftp {Data Type} nscd-cache
11881 Data type representing a cache database of nscd and its parameters.
11885 @item @code{database}
11886 This is a symbol representing the name of the database to be cached.
11887 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
11888 @code{services}, which designate the corresponding NSS database
11889 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
11891 @item @code{positive-time-to-live}
11892 @itemx @code{negative-time-to-live} (default: @code{20})
11893 A number representing the number of seconds during which a positive or
11894 negative lookup result remains in cache.
11896 @item @code{check-files?} (default: @code{#t})
11897 Whether to check for updates of the files corresponding to
11900 For instance, when @var{database} is @code{hosts}, setting this flag
11901 instructs nscd to check for updates in @file{/etc/hosts} and to take
11904 @item @code{persistent?} (default: @code{#t})
11905 Whether the cache should be stored persistently on disk.
11907 @item @code{shared?} (default: @code{#t})
11908 Whether the cache should be shared among users.
11910 @item @code{max-database-size} (default: 32@tie{}MiB)
11911 Maximum size in bytes of the database cache.
11913 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
11914 @c settings, so leave them out.
11919 @defvr {Scheme Variable} %nscd-default-caches
11920 List of @code{<nscd-cache>} objects used by default by
11921 @code{nscd-configuration} (see above).
11923 It enables persistent and aggressive caching of service and host name
11924 lookups. The latter provides better host name lookup performance,
11925 resilience in the face of unreliable name servers, and also better
11926 privacy---often the result of host name lookups is in local cache, so
11927 external name servers do not even need to be queried.
11930 @anchor{syslog-configuration-type}
11933 @deftp {Data Type} syslog-configuration
11934 This data type represents the configuration of the syslog daemon.
11937 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
11938 The syslog daemon to use.
11940 @item @code{config-file} (default: @code{%default-syslog.conf})
11941 The syslog configuration file to use.
11946 @anchor{syslog-service}
11948 @deffn {Scheme Procedure} syslog-service @var{config}
11949 Return a service that runs a syslog daemon according to @var{config}.
11951 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
11952 information on the configuration file syntax.
11955 @defvr {Scheme Variable} guix-service-type
11956 This is the type of the service that runs the build daemon,
11957 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
11958 @code{guix-configuration} record as described below.
11961 @anchor{guix-configuration-type}
11962 @deftp {Data Type} guix-configuration
11963 This data type represents the configuration of the Guix build daemon.
11964 @xref{Invoking guix-daemon}, for more information.
11967 @item @code{guix} (default: @var{guix})
11968 The Guix package to use.
11970 @item @code{build-group} (default: @code{"guixbuild"})
11971 Name of the group for build user accounts.
11973 @item @code{build-accounts} (default: @code{10})
11974 Number of build user accounts to create.
11976 @item @code{authorize-key?} (default: @code{#t})
11977 @cindex substitutes, authorization thereof
11978 Whether to authorize the substitute keys listed in
11979 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
11980 (@pxref{Substitutes}).
11982 @vindex %default-authorized-guix-keys
11983 @item @code{authorized-keys} (default: @var{%default-authorized-guix-keys})
11984 The list of authorized key files for archive imports, as a list of
11985 string-valued gexps (@pxref{Invoking guix archive}). By default, it
11986 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
11988 @item @code{use-substitutes?} (default: @code{#t})
11989 Whether to use substitutes.
11991 @item @code{substitute-urls} (default: @var{%default-substitute-urls})
11992 The list of URLs where to look for substitutes by default.
11994 @item @code{max-silent-time} (default: @code{0})
11995 @itemx @code{timeout} (default: @code{0})
11996 The number of seconds of silence and the number of seconds of activity,
11997 respectively, after which a build process times out. A value of zero
11998 disables the timeout.
12000 @item @code{log-compression} (default: @code{'bzip2})
12001 The type of compression used for build logs---one of @code{gzip},
12002 @code{bzip2}, or @code{none}.
12004 @item @code{extra-options} (default: @code{'()})
12005 List of extra command-line options for @command{guix-daemon}.
12007 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
12008 File where @command{guix-daemon}'s standard output and standard error
12011 @item @code{http-proxy} (default: @code{#f})
12012 The HTTP proxy used for downloading fixed-output derivations and
12015 @item @code{tmpdir} (default: @code{#f})
12016 A directory path where the @command{guix-daemon} will perform builds.
12021 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
12022 Run @var{udev}, which populates the @file{/dev} directory dynamically.
12023 udev rules can be provided as a list of files through the @var{rules}
12024 variable. The procedures @var{udev-rule} and @var{file->udev-rule} from
12025 @code{(gnu services base)} simplify the creation of such rule files.
12028 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
12029 Return a udev-rule file named @var{file-name} containing the rules
12030 defined by the @var{contents} literal.
12032 In the following example, a rule for a USB device is defined to be
12033 stored in the file @file{90-usb-thing.rules}. The rule runs a script
12034 upon detecting a USB device with a given product identifier.
12037 (define %example-udev-rule
12039 "90-usb-thing.rules"
12040 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
12041 "ATTR@{product@}==\"Example\", "
12042 "RUN+=\"/path/to/script\"")))
12045 The @command{herd rules udev} command, as root, returns the name of the
12046 directory containing all the active udev rules.
12049 Here we show how the default @var{udev-service} can be extended with it.
12055 (modify-services %desktop-services
12056 (udev-service-type config =>
12057 (udev-configuration (inherit config)
12058 (rules (append (udev-configuration-rules config)
12059 (list %example-udev-rule))))))))
12062 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
12063 Return a udev file named @var{file-name} containing the rules defined
12064 within @var{file}, a file-like object.
12066 The following example showcases how we can use an existing rule file.
12069 (use-modules (guix download) ;for url-fetch
12070 (guix packages) ;for origin
12073 (define %android-udev-rules
12075 "51-android-udev.rules"
12076 (let ((version "20170910"))
12079 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
12080 "android-udev-rules/" version "/51-android.rules"))
12082 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
12086 Additionally, Guix package definitions can be included in @var{rules} in
12087 order to extend the udev rules with the definitions found under their
12088 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
12089 @var{file->udev-rule} example, we could have used the
12090 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
12091 packages android)} module.
12093 The following example shows how to use the @var{android-udev-rules}
12094 package so that the Android tool @command{adb} can detect devices
12095 without root privileges. It also details how to create the
12096 @code{adbusers} group, which is required for the proper functioning of
12097 the rules defined within the @var{android-udev-rules} package. To
12098 create such a group, we must define it both as part of the
12099 @var{supplementary-groups} of our @var{user-account} declaration, as
12100 well as in the @var{groups} field of the @var{operating-system} record.
12103 (use-modules (gnu packages android) ;for android-udev-rules
12104 (gnu system shadow) ;for user-group
12109 (users (cons (user-acount
12111 (supplementary-groups
12112 '("adbusers" ;for adb
12113 "wheel" "netdev" "audio" "video"))
12116 (groups (cons (user-group (system? #t) (name "adbusers"))
12122 (modify-services %desktop-services
12125 (udev-configuration (inherit config)
12126 (rules (cons android-udev-rules
12127 (udev-configuration-rules config))))))))
12130 @defvr {Scheme Variable} urandom-seed-service-type
12131 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
12132 when rebooting. It also tries to seed @file{/dev/urandom} from
12133 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
12137 @defvr {Scheme Variable} %random-seed-file
12138 This is the name of the file where some random bytes are saved by
12139 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
12140 It defaults to @file{/var/lib/random-seed}.
12145 @defvr {Scheme Variable} gpm-service-type
12146 This is the type of the service that runs GPM, the @dfn{general-purpose
12147 mouse daemon}, which provides mouse support to the Linux console. GPM
12148 allows users to use the mouse in the console, notably to select, copy,
12151 The value for services of this type must be a @code{gpm-configuration}
12152 (see below). This service is not part of @var{%base-services}.
12155 @deftp {Data Type} gpm-configuration
12156 Data type representing the configuration of GPM.
12159 @item @code{options} (default: @code{%default-gpm-options})
12160 Command-line options passed to @command{gpm}. The default set of
12161 options instruct @command{gpm} to listen to mouse events on
12162 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
12165 @item @code{gpm} (default: @code{gpm})
12166 The GPM package to use.
12171 @anchor{guix-publish-service-type}
12172 @deffn {Scheme Variable} guix-publish-service-type
12173 This is the service type for @command{guix publish} (@pxref{Invoking
12174 guix publish}). Its value must be a @code{guix-configuration}
12175 object, as described below.
12177 This assumes that @file{/etc/guix} already contains a signing key pair as
12178 created by @command{guix archive --generate-key} (@pxref{Invoking guix
12179 archive}). If that is not the case, the service will fail to start.
12182 @deftp {Data Type} guix-publish-configuration
12183 Data type representing the configuration of the @code{guix publish}
12187 @item @code{guix} (default: @code{guix})
12188 The Guix package to use.
12190 @item @code{port} (default: @code{80})
12191 The TCP port to listen for connections.
12193 @item @code{host} (default: @code{"localhost"})
12194 The host (and thus, network interface) to listen to. Use
12195 @code{"0.0.0.0"} to listen on all the network interfaces.
12197 @item @code{compression-level} (default: @code{3})
12198 The gzip compression level at which substitutes are compressed. Use
12199 @code{0} to disable compression altogether, and @code{9} to get the best
12200 compression ratio at the expense of increased CPU usage.
12202 @item @code{nar-path} (default: @code{"nar"})
12203 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
12204 publish, @code{--nar-path}}, for details.
12206 @item @code{cache} (default: @code{#f})
12207 When it is @code{#f}, disable caching and instead generate archives on
12208 demand. Otherwise, this should be the name of a directory---e.g.,
12209 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
12210 archives and meta-data ready to be sent. @xref{Invoking guix publish,
12211 @option{--cache}}, for more information on the tradeoffs involved.
12213 @item @code{workers} (default: @code{#f})
12214 When it is an integer, this is the number of worker threads used for
12215 caching; when @code{#f}, the number of processors is used.
12216 @xref{Invoking guix publish, @option{--workers}}, for more information.
12218 @item @code{ttl} (default: @code{#f})
12219 When it is an integer, this denotes the @dfn{time-to-live} in seconds
12220 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
12221 for more information.
12225 @anchor{rngd-service}
12226 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
12227 [#:device "/dev/hwrng"]
12228 Return a service that runs the @command{rngd} program from @var{rng-tools}
12229 to add @var{device} to the kernel's entropy pool. The service will fail if
12230 @var{device} does not exist.
12233 @anchor{pam-limits-service}
12234 @cindex session limits
12239 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
12241 Return a service that installs a configuration file for the
12242 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
12243 @code{pam_limits} module}. The procedure optionally takes a list of
12244 @code{pam-limits-entry} values, which can be used to specify
12245 @code{ulimit} limits and nice priority limits to user sessions.
12247 The following limits definition sets two hard and soft limits for all
12248 login sessions of users in the @code{realtime} group:
12251 (pam-limits-service
12253 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
12254 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
12257 The first entry increases the maximum realtime priority for
12258 non-privileged processes; the second entry lifts any restriction of the
12259 maximum address space that can be locked in memory. These settings are
12260 commonly used for real-time audio systems.
12263 @node Scheduled Job Execution
12264 @subsection Scheduled Job Execution
12268 @cindex scheduling jobs
12269 The @code{(gnu services mcron)} module provides an interface to
12270 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
12271 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
12272 Unix @command{cron} daemon; the main difference is that it is
12273 implemented in Guile Scheme, which provides a lot of flexibility when
12274 specifying the scheduling of jobs and their actions.
12276 The example below defines an operating system that runs the
12277 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
12278 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
12279 well as the @command{mkid} command on behalf of an unprivileged user
12280 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
12281 gexps to introduce job definitions that are passed to mcron
12282 (@pxref{G-Expressions}).
12285 (use-modules (guix) (gnu) (gnu services mcron))
12286 (use-package-modules base idutils)
12288 (define updatedb-job
12289 ;; Run 'updatedb' at 3AM every day. Here we write the
12290 ;; job's action as a Scheme procedure.
12291 #~(job '(next-hour '(3))
12293 (execl (string-append #$findutils "/bin/updatedb")
12295 "--prunepaths=/tmp /var/tmp /gnu/store"))))
12297 (define garbage-collector-job
12298 ;; Collect garbage 5 minutes after midnight every day.
12299 ;; The job's action is a shell command.
12300 #~(job "5 0 * * *" ;Vixie cron syntax
12303 (define idutils-job
12304 ;; Update the index database as user "charlie" at 12:15PM
12305 ;; and 19:15PM. This runs from the user's home directory.
12306 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
12307 (string-append #$idutils "/bin/mkid src")
12312 (services (cons (service mcron-service-type
12313 (mcron-configuration
12314 (jobs (list garbage-collector-job
12320 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
12321 for more information on mcron job specifications. Below is the
12322 reference of the mcron service.
12324 On a running system, you can use the @code{schedule} action of the service to
12325 visualize the mcron jobs that will be executed next:
12328 # herd schedule mcron
12332 The example above lists the next five tasks that will be executed, but you can
12333 also specify the number of tasks to display:
12336 # herd schedule mcron 10
12339 @defvr {Scheme Variable} mcron-service-type
12340 This is the type of the @code{mcron} service, whose value is an
12341 @code{mcron-configuration} object.
12343 This service type can be the target of a service extension that provides
12344 it additional job specifications (@pxref{Service Composition}). In
12345 other words, it is possible to define services that provide additional
12349 @deftp {Data Type} mcron-configuration
12350 Data type representing the configuration of mcron.
12353 @item @code{mcron} (default: @var{mcron})
12354 The mcron package to use.
12357 This is a list of gexps (@pxref{G-Expressions}), where each gexp
12358 corresponds to an mcron job specification (@pxref{Syntax, mcron job
12359 specifications,, mcron, GNU@tie{}mcron}).
12365 @subsection Log Rotation
12368 @cindex log rotation
12370 Log files such as those found in @file{/var/log} tend to grow endlessly,
12371 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
12372 their contents in separate files, possibly compressed. The @code{(gnu
12373 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
12374 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
12376 The example below defines an operating system that provides log rotation
12377 with the default settings, for commonly encountered log files.
12380 (use-modules (guix) (gnu))
12381 (use-service-modules admin mcron)
12382 (use-package-modules base idutils)
12386 (services (cons (service rottlog-service-type)
12390 @defvr {Scheme Variable} rottlog-service-type
12391 This is the type of the Rottlog service, whose value is a
12392 @code{rottlog-configuration} object.
12394 Other services can extend this one with new @code{log-rotation} objects
12395 (see below), thereby augmenting the set of files to be rotated.
12397 This service type can define mcron jobs (@pxref{Scheduled Job
12398 Execution}) to run the rottlog service.
12401 @deftp {Data Type} rottlog-configuration
12402 Data type representing the configuration of rottlog.
12405 @item @code{rottlog} (default: @code{rottlog})
12406 The Rottlog package to use.
12408 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
12409 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
12410 rottlog, GNU Rot[t]log Manual}).
12412 @item @code{rotations} (default: @code{%default-rotations})
12413 A list of @code{log-rotation} objects as defined below.
12416 This is a list of gexps where each gexp corresponds to an mcron job
12417 specification (@pxref{Scheduled Job Execution}).
12421 @deftp {Data Type} log-rotation
12422 Data type representing the rotation of a group of log files.
12424 Taking an example from the Rottlog manual (@pxref{Period Related File
12425 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
12431 (files '("/var/log/apache/*"))
12432 (options '("storedir apache-archives"
12438 The list of fields is as follows:
12441 @item @code{frequency} (default: @code{'weekly})
12442 The log rotation frequency, a symbol.
12445 The list of files or file glob patterns to rotate.
12447 @item @code{options} (default: @code{'()})
12448 The list of rottlog options for this rotation (@pxref{Configuration
12449 parameters,,, rottlog, GNU Rot[t]lg Manual}).
12451 @item @code{post-rotate} (default: @code{#f})
12452 Either @code{#f} or a gexp to execute once the rotation has completed.
12456 @defvr {Scheme Variable} %default-rotations
12457 Specifies weekly rotation of @var{%rotated-files} and
12458 a couple of other files.
12461 @defvr {Scheme Variable} %rotated-files
12462 The list of syslog-controlled files to be rotated. By default it is:
12463 @code{'("/var/log/messages" "/var/log/secure")}.
12466 @node Networking Services
12467 @subsection Networking Services
12469 The @code{(gnu services networking)} module provides services to configure
12470 the network interface.
12472 @cindex DHCP, networking service
12473 @defvr {Scheme Variable} dhcp-client-service-type
12474 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
12475 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
12476 is the DHCP client package to use, @code{isc-dhcp} by default.
12479 @deffn {Scheme Procedure} dhcpd-service-type
12480 This type defines a service that runs a DHCP daemon. To create a
12481 service of this type, you must supply a @code{<dhcpd-configuration>}.
12485 (service dhcpd-service-type
12486 (dhcpd-configuration
12487 (config-file (local-file "my-dhcpd.conf"))
12488 (interfaces '("enp0s25"))))
12492 @deftp {Data Type} dhcpd-configuration
12494 @item @code{package} (default: @code{isc-dhcp})
12495 The package that provides the DHCP daemon. This package is expected to
12496 provide the daemon at @file{sbin/dhcpd} relative to its output
12497 directory. The default package is the
12498 @uref{http://www.isc.org/products/DHCP, ISC's DHCP server}.
12499 @item @code{config-file} (default: @code{#f})
12500 The configuration file to use. This is required. It will be passed to
12501 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
12502 object (@pxref{G-Expressions, file-like objects}). See @code{man
12503 dhcpd.conf} for details on the configuration file syntax.
12504 @item @code{version} (default: @code{"4"})
12505 The DHCP version to use. The ISC DHCP server supports the values ``4'',
12506 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
12507 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
12509 @item @code{run-directory} (default: @code{"/run/dhcpd"})
12510 The run directory to use. At service activation time, this directory
12511 will be created if it does not exist.
12512 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
12513 The PID file to use. This corresponds to the @code{-pf} option of
12514 @code{dhcpd}. See @code{man dhcpd} for details.
12515 @item @code{interfaces} (default: @code{'()})
12516 The names of the network interfaces on which dhcpd should listen for
12517 broadcasts. If this list is not empty, then its elements (which must be
12518 strings) will be appended to the @code{dhcpd} invocation when starting
12519 the daemon. It may not be necessary to explicitly specify any
12520 interfaces here; see @code{man dhcpd} for details.
12524 @defvr {Scheme Variable} static-networking-service-type
12525 This is the type for statically-configured network interfaces.
12526 @c TODO Document <static-networking> data structures.
12529 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
12530 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
12531 [#:requirement @code{'(udev)}]
12532 Return a service that starts @var{interface} with address @var{ip}. If
12533 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
12534 it must be a string specifying the default network gateway. @var{requirement}
12535 can be used to declare a dependency on another service before configuring the
12538 This procedure can be called several times, one for each network
12539 interface of interest. Behind the scenes what it does is extend
12540 @code{static-networking-service-type} with additional network interfaces
12546 (static-networking-service "eno1" "192.168.1.82"
12547 #:gateway "192.168.1.2"
12548 #:name-servers '("192.168.1.2"))
12555 @cindex network management
12556 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
12557 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
12558 management daemon that aims to simplify wired and wireless networking.
12560 This service adds the @var{wicd} package to the global profile, providing
12561 several commands to interact with the daemon and configure networking:
12562 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
12563 and @command{wicd-curses} user interfaces.
12566 @cindex ModemManager
12568 @defvr {Scheme Variable} modem-manager-service-type
12569 This is the service type for the
12570 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
12571 service. The value for this service type is a
12572 @code{modem-manager-configuration} record.
12574 This service is part of @code{%desktop-services} (@pxref{Desktop
12578 @deftp {Data Type} modem-manager-configuration
12579 Data type representing the configuration of ModemManager.
12582 @item @code{modem-manager} (default: @code{modem-manager})
12583 The ModemManager package to use.
12588 @cindex NetworkManager
12590 @defvr {Scheme Variable} network-manager-service-type
12591 This is the service type for the
12592 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
12593 service. The value for this service type is a
12594 @code{network-manager-configuration} record.
12596 This service is part of @code{%desktop-services} (@pxref{Desktop
12600 @deftp {Data Type} network-manager-configuration
12601 Data type representing the configuration of NetworkManager.
12604 @item @code{network-manager} (default: @code{network-manager})
12605 The NetworkManager package to use.
12607 @item @code{dns} (default: @code{"default"})
12608 Processing mode for DNS, which affects how NetworkManager uses the
12609 @code{resolv.conf} configuration file.
12613 NetworkManager will update @code{resolv.conf} to reflect the nameservers
12614 provided by currently active connections.
12617 NetworkManager will run @code{dnsmasq} as a local caching nameserver,
12618 using a "split DNS" configuration if you are connected to a VPN, and
12619 then update @code{resolv.conf} to point to the local nameserver.
12622 NetworkManager will not modify @code{resolv.conf}.
12625 @item @code{vpn-plugins} (default: @code{'()})
12626 This is the list of available plugins for virtual private networks
12627 (VPNs). An example of this is the @code{network-manager-openvpn}
12628 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
12634 @deffn {Scheme Variable} connman-service-type
12635 This is the service type to run @url{https://01.org/connman,Connman},
12636 a network connection manager.
12638 Its value must be an
12639 @code{connman-configuration} record as in this example:
12642 (service connman-service-type
12643 (connman-configuration
12644 (disable-vpn? #t)))
12647 See below for details about @code{connman-configuration}.
12650 @deftp {Data Type} connman-configuration
12651 Data Type representing the configuration of connman.
12654 @item @code{connman} (default: @var{connman})
12655 The connman package to use.
12657 @item @code{disable-vpn?} (default: @code{#f})
12658 When true, disable connman's vpn plugin.
12662 @cindex WPA Supplicant
12663 @defvr {Scheme Variable} wpa-supplicant-service-type
12664 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
12665 supplicant}, an authentication daemon required to authenticate against
12666 encrypted WiFi or ethernet networks.
12669 @deftp {Data Type} wpa-supplicant-configuration
12670 Data type representing the configuration of WPA Supplicant.
12672 It takes the following parameters:
12675 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
12676 The WPA Supplicant package to use.
12678 @item @code{dbus?} (default: @code{#t})
12679 Whether to listen for requests on D-Bus.
12681 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
12682 Where to store the PID file.
12684 @item @code{interface} (default: @code{#f})
12685 If this is set, it must specify the name of a network interface that
12686 WPA supplicant will control.
12688 @item @code{config-file} (default: @code{#f})
12689 Optional configuration file to use.
12691 @item @code{extra-options} (default: @code{'()})
12692 List of additional command-line arguments to pass to the daemon.
12697 @defvr {Scheme Variable} iptables-service-type
12698 This is the service type to set up an iptables configuration. iptables is a
12699 packet filtering framework supported by the Linux kernel. This service
12700 supports configuring iptables for both IPv4 and IPv6. A simple example
12701 configuration rejecting all incoming connections except those to the ssh port
12705 (service iptables-service-type
12706 (iptables-configuration
12707 (ipv4-rules (plain-file "iptables.rules" "*filter
12711 -A INPUT -p tcp --dport 22 -j ACCEPT
12712 -A INPUT -j REJECT --reject-with icmp-port-unreachable
12715 (ipv6-rules (plain-file "ip6tables.rules" "*filter
12719 -A INPUT -p tcp --dport 22 -j ACCEPT
12720 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
12726 @deftp {Data Type} iptables-configuration
12727 The data type representing the configuration of iptables.
12730 @item @code{iptables} (default: @code{iptables})
12731 The iptables package that provides @code{iptables-restore} and
12732 @code{ip6tables-restore}.
12733 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
12734 The iptables rules to use. It will be passed to @code{iptables-restore}.
12735 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12737 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
12738 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
12739 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12744 @cindex NTP (Network Time Protocol), service
12745 @cindex real time clock
12746 @defvr {Scheme Variable} ntp-service-type
12747 This is the type of the service running the @uref{http://www.ntp.org,
12748 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
12749 system clock synchronized with that of the specified NTP servers.
12751 The value of this service is an @code{ntpd-configuration} object, as described
12755 @deftp {Data Type} ntp-configuration
12756 This is the data type for the NTP service configuration.
12759 @item @code{servers} (default: @code{%ntp-servers})
12760 This is the list of servers (host names) with which @command{ntpd} will be
12763 @item @code{allow-large-adjustment?} (default: @code{#f})
12764 This determines whether @command{ntpd} is allowed to make an initial
12765 adjustment of more than 1,000 seconds.
12767 @item @code{ntp} (default: @code{ntp})
12768 The NTP package to use.
12772 @defvr {Scheme Variable} %ntp-servers
12773 List of host names used as the default NTP servers. These are servers of the
12774 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
12778 @deffn {Scheme Procedure} openntpd-service-type
12779 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
12780 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
12781 clock synchronized with that of the given servers.
12785 openntpd-service-type
12786 (openntpd-configuration
12787 (listen-on '("127.0.0.1" "::1"))
12788 (sensor '("udcf0 correction 70000"))
12789 (constraint-from '("www.gnu.org"))
12790 (constraints-from '("https://www.google.com/"))
12791 (allow-large-adjustment? #t)))
12796 @deftp {Data Type} openntpd-configuration
12798 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
12799 The openntpd executable to use.
12800 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
12801 A list of local IP addresses or hostnames the ntpd daemon should listen on.
12802 @item @code{query-from} (default: @code{'()})
12803 A list of local IP address the ntpd daemon should use for outgoing queries.
12804 @item @code{sensor} (default: @code{'()})
12805 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
12806 will listen to each sensor that acutally exists and ignore non-existant ones.
12807 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
12809 @item @code{server} (default: @var{%ntp-servers})
12810 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
12811 @item @code{servers} (default: @code{'()})
12812 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
12813 @item @code{constraint-from} (default: @code{'()})
12814 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
12815 This time information is not used for precision but acts as an authenticated
12816 constraint, thereby reducing the impact of unauthenticated NTP
12817 man-in-the-middle attacks.
12818 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
12820 @item @code{constraints-from} (default: @code{'()})
12821 As with constraint from, specify a list of URLs, IP addresses or hostnames of
12822 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
12823 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
12824 @item @code{allow-large-adjustment?} (default: @code{#f})
12825 Determines if @code{ntpd} is allowed to make an initial adjustment of more
12831 @deffn {Scheme variable} inetd-service-type
12832 This service runs the @command{inetd} (@pxref{inetd invocation,,,
12833 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
12834 connections on internet sockets, and lazily starts the specified server
12835 program when a connection is made on one of these sockets.
12837 The value of this service is an @code{inetd-configuration} object. The
12838 following example configures the @command{inetd} daemon to provide the
12839 built-in @command{echo} service, as well as an smtp service which
12840 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
12841 gateway @code{hostname}:
12846 (inetd-configuration
12850 (socket-type 'stream)
12857 (socket-type 'stream)
12861 (program (file-append openssh "/bin/ssh"))
12863 '("ssh" "-qT" "-i" "/path/to/ssh_key"
12864 "-W" "smtp-server:25" "user@@hostname")))))
12867 See below for more details about @code{inetd-configuration}.
12870 @deftp {Data Type} inetd-configuration
12871 Data type representing the configuration of @command{inetd}.
12874 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
12875 The @command{inetd} executable to use.
12877 @item @code{entries} (default: @code{'()})
12878 A list of @command{inetd} service entries. Each entry should be created
12879 by the @code{inetd-entry} constructor.
12883 @deftp {Data Type} inetd-entry
12884 Data type representing an entry in the @command{inetd} configuration.
12885 Each entry corresponds to a socket where @command{inetd} will listen for
12889 @item @code{node} (default: @code{#f})
12890 Optional string, a comma-separated list of local addresses
12891 @command{inetd} should use when listening for this service.
12892 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
12893 description of all options.
12895 A string, the name must correspond to an entry in @code{/etc/services}.
12896 @item @code{socket-type}
12897 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
12899 @item @code{protocol}
12900 A string, must correspond to an entry in @code{/etc/protocols}.
12901 @item @code{wait?} (default: @code{#t})
12902 Whether @command{inetd} should wait for the server to exit before
12903 listening to new service requests.
12905 A string containing the user (and, optionally, group) name of the user
12906 as whom the server should run. The group name can be specified in a
12907 suffix, separated by a colon or period, i.e.@: @code{"user"},
12908 @code{"user:group"} or @code{"user.group"}.
12909 @item @code{program} (default: @code{"internal"})
12910 The server program which will serve the requests, or @code{"internal"}
12911 if @command{inetd} should use a built-in service.
12912 @item @code{arguments} (default: @code{'()})
12913 A list strings or file-like objects, which are the server program's
12914 arguments, starting with the zeroth argument, i.e.@: the name of the
12915 program itself. For @command{inetd}'s internal services, this entry
12916 must be @code{'()} or @code{'("internal")}.
12919 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
12920 detailed discussion of each configuration field.
12924 @defvr {Scheme Variable} tor-service-type
12925 This is the type for a service that runs the @uref{https://torproject.org,
12926 Tor} anonymous networking daemon. The service is configured using a
12927 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
12928 @code{tor} unprivileged user, which is a member of the @code{tor} group.
12932 @deftp {Data Type} tor-configuration
12934 @item @code{tor} (default: @code{tor})
12935 The package that provides the Tor daemon. This package is expected to provide
12936 the daemon at @file{bin/tor} relative to its output directory. The default
12937 package is the @uref{https://www.torproject.org, Tor Project's}
12940 @item @code{config-file} (default: @code{(plain-file "empty" "")})
12941 The configuration file to use. It will be appended to a default configuration
12942 file, and the final configuration file will be passed to @code{tor} via its
12943 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
12944 file-like objects}). See @code{man tor} for details on the configuration file
12947 @item @code{hidden-services} (default: @code{'()})
12948 The list of @code{<hidden-service>} records to use. For any hidden service
12949 you include in this list, appropriate configuration to enable the hidden
12950 service will be automatically added to the default configuration file. You
12951 may conveniently create @code{<hidden-service>} records using the
12952 @code{tor-hidden-service} procedure described below.
12954 @item @code{socks-socket-type} (default: @code{'tcp})
12955 The default socket type that Tor should use for its SOCKS socket. This must
12956 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
12957 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
12958 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
12959 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
12962 If you want to customize the SOCKS socket in more detail, leave
12963 @code{socks-socket-type} at its default value of @code{'tcp} and use
12964 @code{config-file} to override the default by providing your own
12965 @code{SocksPort} option.
12969 @cindex hidden service
12970 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
12971 Define a new Tor @dfn{hidden service} called @var{name} and implementing
12972 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
12975 '((22 "127.0.0.1:22")
12976 (80 "127.0.0.1:8080"))
12979 In this example, port 22 of the hidden service is mapped to local port 22, and
12980 port 80 is mapped to local port 8080.
12982 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
12983 the @file{hostname} file contains the @code{.onion} host name for the hidden
12986 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
12987 project's documentation} for more information.
12990 The @code{(gnu services rsync)} module provides the following services:
12992 You might want an rsync daemon if you have files that you want available
12993 so anyone (or just yourself) can download existing files or upload new
12996 @deffn {Scheme Variable} rsync-service-type
12997 This is the type for the @uref{https://rsync.samba.org, rsync} rsync daemon,
12998 @command{rsync-configuration} record as in this example:
13001 (service rsync-service-type)
13004 See below for details about @code{rsync-configuration}.
13007 @deftp {Data Type} rsync-configuration
13008 Data type representing the configuration for @code{rsync-service}.
13011 @item @code{package} (default: @var{rsync})
13012 @code{rsync} package to use.
13014 @item @code{port-number} (default: @code{873})
13015 TCP port on which @command{rsync} listens for incoming connections. If port
13016 is less than @code{1024} @command{rsync} needs to be started as the
13017 @code{root} user and group.
13019 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
13020 Name of the file where @command{rsync} writes its PID.
13022 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
13023 Name of the file where @command{rsync} writes its lock file.
13025 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
13026 Name of the file where @command{rsync} writes its log file.
13028 @item @code{use-chroot?} (default: @var{#t})
13029 Whether to use chroot for @command{rsync} shared directory.
13031 @item @code{share-path} (default: @file{/srv/rsync})
13032 Location of the @command{rsync} shared directory.
13034 @item @code{share-comment} (default: @code{"Rsync share"})
13035 Comment of the @command{rsync} shared directory.
13037 @item @code{read-only?} (default: @var{#f})
13038 Read-write permissions to shared directory.
13040 @item @code{timeout} (default: @code{300})
13041 I/O timeout in seconds.
13043 @item @code{user} (default: @var{"root"})
13044 Owner of the @code{rsync} process.
13046 @item @code{group} (default: @var{"root"})
13047 Group of the @code{rsync} process.
13049 @item @code{uid} (default: @var{"rsyncd"})
13050 User name or user ID that file transfers to and from that module should take
13051 place as when the daemon was run as @code{root}.
13053 @item @code{gid} (default: @var{"rsyncd"})
13054 Group name or group ID that will be used when accessing the module.
13059 Furthermore, @code{(gnu services ssh)} provides the following services.
13063 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
13064 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
13065 [#:allow-empty-passwords? #f] [#:root-login? #f] @
13066 [#:syslog-output? #t] [#:x11-forwarding? #t] @
13067 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
13068 [#:public-key-authentication? #t] [#:initialize? #t]
13069 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
13070 @var{host-key} must designate a file containing the host key, and readable
13073 When @var{daemonic?} is true, @command{lshd} will detach from the
13074 controlling terminal and log its output to syslogd, unless one sets
13075 @var{syslog-output?} to false. Obviously, it also makes lsh-service
13076 depend on existence of syslogd service. When @var{pid-file?} is true,
13077 @command{lshd} writes its PID to the file called @var{pid-file}.
13079 When @var{initialize?} is true, automatically create the seed and host key
13080 upon service activation if they do not exist yet. This may take long and
13081 require interaction.
13083 When @var{initialize?} is false, it is up to the user to initialize the
13084 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
13085 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
13086 basics,,, lsh, LSH Manual}).
13088 When @var{interfaces} is empty, lshd listens for connections on all the
13089 network interfaces; otherwise, @var{interfaces} must be a list of host names
13092 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
13093 passwords, and @var{root-login?} specifies whether to accept log-ins as
13096 The other options should be self-descriptive.
13101 @deffn {Scheme Variable} openssh-service-type
13102 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
13103 shell daemon, @command{sshd}. Its value must be an
13104 @code{openssh-configuration} record as in this example:
13107 (service openssh-service-type
13108 (openssh-configuration
13109 (x11-forwarding? #t)
13110 (permit-root-login 'without-password)
13112 `(("alice" ,(local-file "alice.pub"))
13113 ("bob" ,(local-file "bob.pub"))))))
13116 See below for details about @code{openssh-configuration}.
13118 This service can be extended with extra authorized keys, as in this
13122 (service-extension openssh-service-type
13123 (const `(("charlie"
13124 ,(local-file "charlie.pub")))))
13128 @deftp {Data Type} openssh-configuration
13129 This is the configuration record for OpenSSH's @command{sshd}.
13132 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
13133 Name of the file where @command{sshd} writes its PID.
13135 @item @code{port-number} (default: @code{22})
13136 TCP port on which @command{sshd} listens for incoming connections.
13138 @item @code{permit-root-login} (default: @code{#f})
13139 This field determines whether and when to allow logins as root. If
13140 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
13141 If it's the symbol @code{'without-password}, then root logins are
13142 permitted but not with password-based authentication.
13144 @item @code{allow-empty-passwords?} (default: @code{#f})
13145 When true, users with empty passwords may log in. When false, they may
13148 @item @code{password-authentication?} (default: @code{#t})
13149 When true, users may log in with their password. When false, they have
13150 other authentication methods.
13152 @item @code{public-key-authentication?} (default: @code{#t})
13153 When true, users may log in using public key authentication. When
13154 false, users have to use other authentication method.
13156 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
13157 This is used only by protocol version 2.
13159 @item @code{x11-forwarding?} (default: @code{#f})
13160 When true, forwarding of X11 graphical client connections is
13161 enabled---in other words, @command{ssh} options @option{-X} and
13162 @option{-Y} will work.
13164 @item @code{allow-agent-forwarding?} (default: @code{#t})
13165 Whether to allow agent forwarding.
13167 @item @code{allow-tcp-forwarding?} (default: @code{#t})
13168 Whether to allow TCP forwarding.
13170 @item @code{gateway-ports?} (default: @code{#f})
13171 Whether to allow gateway ports.
13173 @item @code{challenge-response-authentication?} (default: @code{#f})
13174 Specifies whether challenge response authentication is allowed (e.g.@: via
13177 @item @code{use-pam?} (default: @code{#t})
13178 Enables the Pluggable Authentication Module interface. If set to
13179 @code{#t}, this will enable PAM authentication using
13180 @code{challenge-response-authentication?} and
13181 @code{password-authentication?}, in addition to PAM account and session
13182 module processing for all authentication types.
13184 Because PAM challenge response authentication usually serves an
13185 equivalent role to password authentication, you should disable either
13186 @code{challenge-response-authentication?} or
13187 @code{password-authentication?}.
13189 @item @code{print-last-log?} (default: @code{#t})
13190 Specifies whether @command{sshd} should print the date and time of the
13191 last user login when a user logs in interactively.
13193 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
13194 Configures external subsystems (e.g.@: file transfer daemon).
13196 This is a list of two-element lists, each of which containing the
13197 subsystem name and a command (with optional arguments) to execute upon
13200 The command @command{internal-sftp} implements an in-process SFTP
13201 server. Alternately, one can specify the @command{sftp-server} command:
13203 (service openssh-service-type
13204 (openssh-configuration
13206 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
13209 @item @code{accepted-environment} (default: @code{'()})
13210 List of strings describing which environment variables may be exported.
13212 Each string gets on its own line. See the @code{AcceptEnv} option in
13213 @code{man sshd_config}.
13215 This example allows ssh-clients to export the @code{COLORTERM} variable.
13216 It is set by terminal emulators, which support colors. You can use it in
13217 your shell's ressource file to enable colors for the prompt and commands
13218 if this variable is set.
13221 (service openssh-service-type
13222 (openssh-configuration
13223 (accepted-environment '("COLORTERM"))))
13226 @item @code{authorized-keys} (default: @code{'()})
13227 @cindex authorized keys, SSH
13228 @cindex SSH authorized keys
13229 This is the list of authorized keys. Each element of the list is a user
13230 name followed by one or more file-like objects that represent SSH public
13234 (openssh-configuration
13236 `(("rekado" ,(local-file "rekado.pub"))
13237 ("chris" ,(local-file "chris.pub"))
13238 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
13242 registers the specified public keys for user accounts @code{rekado},
13243 @code{chris}, and @code{root}.
13245 Additional authorized keys can be specified @i{via}
13246 @code{service-extension}.
13248 Note that this does @emph{not} interfere with the use of
13249 @file{~/.ssh/authorized_keys}.
13251 @item @code{log-level} (default: @code{'info})
13252 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
13253 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
13254 page for @file{sshd_config} for the full list of level names.
13256 @item @code{extra-content} (default: @code{""})
13257 This field can be used to append arbitrary text to the configuration file. It
13258 is especially useful for elaborate configurations that cannot be expressed
13259 otherwise. This configuration, for example, would generally disable root
13260 logins, but permit them from one specific IP address:
13263 (openssh-configuration
13265 Match Address 192.168.0.1
13266 PermitRootLogin yes"))
13272 @deffn {Scheme Procedure} dropbear-service [@var{config}]
13273 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
13274 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
13277 For example, to specify a Dropbear service listening on port 1234, add
13278 this call to the operating system's @code{services} field:
13281 (dropbear-service (dropbear-configuration
13282 (port-number 1234)))
13286 @deftp {Data Type} dropbear-configuration
13287 This data type represents the configuration of a Dropbear SSH daemon.
13290 @item @code{dropbear} (default: @var{dropbear})
13291 The Dropbear package to use.
13293 @item @code{port-number} (default: 22)
13294 The TCP port where the daemon waits for incoming connections.
13296 @item @code{syslog-output?} (default: @code{#t})
13297 Whether to enable syslog output.
13299 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
13300 File name of the daemon's PID file.
13302 @item @code{root-login?} (default: @code{#f})
13303 Whether to allow @code{root} logins.
13305 @item @code{allow-empty-passwords?} (default: @code{#f})
13306 Whether to allow empty passwords.
13308 @item @code{password-authentication?} (default: @code{#t})
13309 Whether to enable password-based authentication.
13313 @defvr {Scheme Variable} %facebook-host-aliases
13314 This variable contains a string for use in @file{/etc/hosts}
13315 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
13316 line contains a entry that maps a known server name of the Facebook
13317 on-line service---e.g., @code{www.facebook.com}---to the local
13318 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
13320 This variable is typically used in the @code{hosts-file} field of an
13321 @code{operating-system} declaration (@pxref{operating-system Reference,
13322 @file{/etc/hosts}}):
13325 (use-modules (gnu) (guix))
13328 (host-name "mymachine")
13331 ;; Create a /etc/hosts file with aliases for "localhost"
13332 ;; and "mymachine", as well as for Facebook servers.
13333 (plain-file "hosts"
13334 (string-append (local-host-aliases host-name)
13335 %facebook-host-aliases))))
13338 This mechanism can prevent programs running locally, such as Web
13339 browsers, from accessing Facebook.
13342 The @code{(gnu services avahi)} provides the following definition.
13344 @defvr {Scheme Variable} avahi-service-type
13345 This is the service that runs @command{avahi-daemon}, a system-wide
13346 mDNS/DNS-SD responder that allows for service discovery and
13347 ``zero-configuration'' host name lookups (see @uref{http://avahi.org/}).
13348 Its value must be a @code{zero-configuration} record---see below.
13350 This service extends the name service cache daemon (nscd) so that it can
13351 resolve @code{.local} host names using
13352 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
13353 Service Switch}, for information on host name resolution.
13355 Additionally, add the @var{avahi} package to the system profile so that
13356 commands such as @command{avahi-browse} are directly usable.
13359 @deftp {Data Type} avahi-configuration
13360 Data type representation the configuration for Avahi.
13364 @item @code{host-name} (default: @code{#f})
13365 If different from @code{#f}, use that as the host name to
13366 publish for this machine; otherwise, use the machine's actual host name.
13368 @item @code{publish?} (default: @code{#t})
13369 When true, allow host names and services to be published (broadcast) over the
13372 @item @code{publish-workstation?} (default: @code{#t})
13373 When true, @command{avahi-daemon} publishes the machine's host name and IP
13374 address via mDNS on the local network. To view the host names published on
13375 your local network, you can run:
13378 avahi-browse _workstation._tcp
13381 @item @code{wide-area?} (default: @code{#f})
13382 When true, DNS-SD over unicast DNS is enabled.
13384 @item @code{ipv4?} (default: @code{#t})
13385 @itemx @code{ipv6?} (default: @code{#t})
13386 These fields determine whether to use IPv4/IPv6 sockets.
13388 @item @code{domains-to-browse} (default: @code{'()})
13389 This is a list of domains to browse.
13393 @deffn {Scheme Variable} openvswitch-service-type
13394 This is the type of the @uref{http://www.openvswitch.org, Open vSwitch}
13395 service, whose value should be an @code{openvswitch-configuration}
13399 @deftp {Data Type} openvswitch-configuration
13400 Data type representing the configuration of Open vSwitch, a multilayer
13401 virtual switch which is designed to enable massive network automation
13402 through programmatic extension.
13405 @item @code{package} (default: @var{openvswitch})
13406 Package object of the Open vSwitch.
13412 @subsection X Window
13415 @cindex X Window System
13416 @cindex login manager
13417 Support for the X Window graphical display system---specifically
13418 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
13419 there is no @code{xorg-service} procedure. Instead, the X server is
13420 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
13423 @cindex GNOME, login manager
13424 GDM of course allows users to log in into window managers and desktop
13425 environments other than GNOME; for those using GNOME, GDM is required for
13426 features such as automatic screen locking.
13428 @cindex window manager
13429 To use X11, you must install at least one @dfn{window manager}---for
13430 example the @code{windowmaker} or @code{openbox} packages---preferably
13431 by adding it to the @code{packages} field of your operating system
13432 definition (@pxref{operating-system Reference, system-wide packages}).
13434 @defvr {Scheme Variable} gdm-service-type
13435 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
13436 Desktop Manager} (GDM), a program that manages graphical display servers and
13437 handles graphical user logins. Its value must be a @code{gdm-configuration}
13440 @cindex session types (X11)
13441 @cindex X11 session types
13442 GDM looks for @dfn{session types} described by the @file{.desktop} files in
13443 @file{/run/current-system/profile/share/xsessions} and allows users to choose
13444 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
13445 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
13446 set of packages automatically makes them available at the log-in screen.
13448 In addition, @file{~/.xsession} files are honored. When available,
13449 @file{~/.xsession} must be an executable that starts a window manager
13450 and/or other X clients.
13453 @deftp {Data Type} gdm-configuration
13455 @item @code{auto-login?} (default: @code{#f})
13456 @itemx @code{default-user} (default: @code{#f})
13457 When @code{auto-login?} is false, GDM presents a log-in screen.
13459 When @code{auto-login?} is true, GDM logs in directly as
13460 @code{default-user}.
13462 @item @code{gnome-shell-assets} (default: ...)
13463 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
13465 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
13466 Configuration of the Xorg graphical server.
13468 @item @code{xsession} (default: @code{(xinitrc)})
13469 Script to run before starting a X session.
13471 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
13472 File name of the @code{dbus-daemon} executable.
13474 @item @code{gdm} (default: @code{gdm})
13475 The GDM package to use.
13479 @defvr {Scheme Variable} slim-service-type
13480 This is the type for the SLiM graphical login manager for X11.
13482 Like GDM, SLiM looks for session types described by @file{.desktop} files and
13483 allows users to choose a session from the log-in screen using @kbd{F1}. It
13484 also honors @file{~/.xsession} files.
13487 @deftp {Data Type} slim-configuration
13488 Data type representing the configuration of @code{slim-service-type}.
13491 @item @code{allow-empty-passwords?} (default: @code{#t})
13492 Whether to allow logins with empty passwords.
13494 @item @code{auto-login?} (default: @code{#f})
13495 @itemx @code{default-user} (default: @code{""})
13496 When @code{auto-login?} is false, SLiM presents a log-in screen.
13498 When @code{auto-login?} is true, SLiM logs in directly as
13499 @code{default-user}.
13501 @item @code{theme} (default: @code{%default-slim-theme})
13502 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
13503 The graphical theme to use and its name.
13505 @item @code{auto-login-session} (default: @code{#f})
13506 If true, this must be the name of the executable to start as the default
13507 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
13509 If false, a session described by one of the available @file{.desktop}
13510 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
13514 You must install at least one window manager in the system profile or in
13515 your user profile. Failing to do that, if @code{auto-login-session} is
13516 false, you will be unable to log in.
13519 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13520 Configuration of the Xorg graphical server.
13522 @item @code{xauth} (default: @code{xauth})
13523 The XAuth package to use.
13525 @item @code{shepherd} (default: @code{shepherd})
13526 The Shepherd package used when invoking @command{halt} and
13529 @item @code{sessreg} (default: @code{sessreg})
13530 The sessreg package used in order to register the session.
13532 @item @code{slim} (default: @code{slim})
13533 The SLiM package to use.
13537 @defvr {Scheme Variable} %default-theme
13538 @defvrx {Scheme Variable} %default-theme-name
13539 The default SLiM theme and its name.
13543 @deftp {Data Type} sddm-configuration
13544 This is the data type representing the sddm service configuration.
13547 @item @code{display-server} (default: "x11")
13548 Select display server to use for the greeter. Valid values are "x11"
13551 @item @code{numlock} (default: "on")
13552 Valid values are "on", "off" or "none".
13554 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
13555 Command to run when halting.
13557 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
13558 Command to run when rebooting.
13560 @item @code{theme} (default "maldives")
13561 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
13563 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
13564 Directory to look for themes.
13566 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
13567 Directory to look for faces.
13569 @item @code{default-path} (default "/run/current-system/profile/bin")
13570 Default PATH to use.
13572 @item @code{minimum-uid} (default 1000)
13573 Minimum UID to display in SDDM.
13575 @item @code{maximum-uid} (default 2000)
13576 Maximum UID to display in SDDM
13578 @item @code{remember-last-user?} (default #t)
13579 Remember last user.
13581 @item @code{remember-last-session?} (default #t)
13582 Remember last session.
13584 @item @code{hide-users} (default "")
13585 Usernames to hide from SDDM greeter.
13587 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
13588 Users with shells listed will be hidden from the SDDM greeter.
13590 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
13591 Script to run before starting a wayland session.
13593 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
13594 Directory to look for desktop files starting wayland sessions.
13596 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13597 Configuration of the Xorg graphical server.
13599 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
13602 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
13605 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
13606 Script to run after starting xorg-server.
13608 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
13609 Script to run before stopping xorg-server.
13611 @item @code{xsession-command} (default: @code{xinitrc})
13612 Script to run before starting a X session.
13614 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
13615 Directory to look for desktop files starting X sessions.
13617 @item @code{minimum-vt} (default: 7)
13620 @item @code{auto-login-user} (default "")
13621 User to use for auto-login.
13623 @item @code{auto-login-session} (default "")
13624 Desktop file to use for auto-login.
13626 @item @code{relogin?} (default #f)
13627 Relogin after logout.
13632 @cindex login manager
13634 @deffn {Scheme Procedure} sddm-service config
13635 Return a service that spawns the SDDM graphical login manager for config of
13636 type @code{<sddm-configuration>}.
13639 (sddm-service (sddm-configuration
13640 (auto-login-user "Alice")
13641 (auto-login-session "xfce.desktop")))
13645 @cindex Xorg, configuration
13646 @deftp {Data Type} xorg-configuration
13647 This data type represents the configuration of the Xorg graphical display
13648 server. Note that there is not Xorg service; instead, the X server is started
13649 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
13650 of these display managers aggregates an @code{xorg-configuration} record.
13653 @item @code{modules} (default: @code{%default-xorg-modules})
13654 This is a list of @dfn{module packages} loaded by the Xorg
13655 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
13657 @item @code{fonts} (default: @code{%default-xorg-fonts})
13658 This is a list of font directories to add to the server's @dfn{font path}.
13660 @item @code{drivers} (default: @code{'()})
13661 This must be either the empty list, in which case Xorg chooses a graphics
13662 driver automatically, or a list of driver names that will be tried in this
13663 order---e.g., @code{("modesetting" "vesa")}.
13665 @item @code{resolutions} (default: @code{'()})
13666 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
13667 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
13670 @cindex keyboard layout, for Xorg
13671 @cindex keymap, for Xorg
13672 @item @code{keyboard-layout} (default: @code{#f})
13673 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
13674 English (``qwerty'') for a 105-key PC keyboard.
13676 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
13677 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
13678 information on how to specify the keyboard layout.
13680 @item @code{extra-config} (default: @code{'()})
13681 This is a list of strings or objects appended to the configuration file. It
13682 is used to pass extra text to be added verbatim to the configuration file.
13684 @item @code{server} (default: @code{xorg-server})
13685 This is the package providing the Xorg server.
13687 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
13688 This is the list of command-line arguments to pass to the X server. The
13689 default is @code{-nolisten tcp}.
13693 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
13694 [@var{login-manager-service-type}]
13695 Tell the log-in manager (of type @var{login-manager-service-type}) to use
13696 @var{config}, an <xorg-configuration> record.
13698 Since the Xorg configuration is embedded in the log-in manager's
13699 configuration---e.g., @code{gdm-configuration}---this procedure provides a
13700 shorthand to set the Xorg configuration.
13703 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
13704 Return a @code{startx} script in which the modules, fonts, etc. specified
13705 in @var{config}, are available. The result should be used in place of
13708 Usually the X server is started by a login manager.
13712 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
13713 Add @var{package}, a package for a screen locker or screen saver whose
13714 command is @var{program}, to the set of setuid programs and add a PAM entry
13715 for it. For example:
13718 (screen-locker-service xlockmore "xlock")
13721 makes the good ol' XlockMore usable.
13725 @node Printing Services
13726 @subsection Printing Services
13728 @cindex printer support with CUPS
13729 The @code{(gnu services cups)} module provides a Guix service definition
13730 for the CUPS printing service. To add printer support to a Guix
13731 system, add a @code{cups-service} to the operating system definition:
13733 @deffn {Scheme Variable} cups-service-type
13734 The service type for the CUPS print server. Its value should be a valid
13735 CUPS configuration (see below). To use the default settings, simply
13738 (service cups-service-type)
13742 The CUPS configuration controls the basic things about your CUPS
13743 installation: what interfaces it listens on, what to do if a print job
13744 fails, how much logging to do, and so on. To actually add a printer,
13745 you have to visit the @url{http://localhost:631} URL, or use a tool such
13746 as GNOME's printer configuration services. By default, configuring a
13747 CUPS service will generate a self-signed certificate if needed, for
13748 secure connections to the print server.
13750 Suppose you want to enable the Web interface of CUPS and also add
13751 support for Epson printers @i{via} the @code{escpr} package and for HP
13752 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
13753 like this (you need to use the @code{(gnu packages cups)} module):
13756 (service cups-service-type
13757 (cups-configuration
13758 (web-interface? #t)
13760 (list cups-filters escpr hplip-minimal))))
13763 Note: If you wish to use the Qt5 based GUI which comes with the hplip
13764 package then it is suggested that you install the @code{hplip} package,
13765 either in your OS configuration file or as your user.
13767 The available configuration parameters follow. Each parameter
13768 definition is preceded by its type; for example, @samp{string-list foo}
13769 indicates that the @code{foo} parameter should be specified as a list of
13770 strings. There is also a way to specify the configuration as a string,
13771 if you have an old @code{cupsd.conf} file that you want to port over
13772 from some other system; see the end for more details.
13774 @c The following documentation was initially generated by
13775 @c (generate-documentation) in (gnu services cups). Manually maintained
13776 @c documentation is better, so we shouldn't hesitate to edit below as
13777 @c needed. However if the change you want to make to this documentation
13778 @c can be done in an automated way, it's probably easier to change
13779 @c (generate-documentation) than to make it below and have to deal with
13780 @c the churn as CUPS updates.
13783 Available @code{cups-configuration} fields are:
13785 @deftypevr {@code{cups-configuration} parameter} package cups
13789 @deftypevr {@code{cups-configuration} parameter} package-list extensions
13790 Drivers and other extensions to the CUPS package.
13793 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
13794 Configuration of where to write logs, what directories to use for print
13795 spools, and related privileged configuration parameters.
13797 Available @code{files-configuration} fields are:
13799 @deftypevr {@code{files-configuration} parameter} log-location access-log
13800 Defines the access log filename. Specifying a blank filename disables
13801 access log generation. The value @code{stderr} causes log entries to be
13802 sent to the standard error file when the scheduler is running in the
13803 foreground, or to the system log daemon when run in the background. The
13804 value @code{syslog} causes log entries to be sent to the system log
13805 daemon. The server name may be included in filenames using the string
13806 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
13808 Defaults to @samp{"/var/log/cups/access_log"}.
13811 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
13812 Where CUPS should cache data.
13814 Defaults to @samp{"/var/cache/cups"}.
13817 @deftypevr {@code{files-configuration} parameter} string config-file-perm
13818 Specifies the permissions for all configuration files that the scheduler
13821 Note that the permissions for the printers.conf file are currently
13822 masked to only allow access from the scheduler user (typically root).
13823 This is done because printer device URIs sometimes contain sensitive
13824 authentication information that should not be generally known on the
13825 system. There is no way to disable this security feature.
13827 Defaults to @samp{"0640"}.
13830 @deftypevr {@code{files-configuration} parameter} log-location error-log
13831 Defines the error log filename. Specifying a blank filename disables
13832 access log generation. The value @code{stderr} causes log entries to be
13833 sent to the standard error file when the scheduler is running in the
13834 foreground, or to the system log daemon when run in the background. The
13835 value @code{syslog} causes log entries to be sent to the system log
13836 daemon. The server name may be included in filenames using the string
13837 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
13839 Defaults to @samp{"/var/log/cups/error_log"}.
13842 @deftypevr {@code{files-configuration} parameter} string fatal-errors
13843 Specifies which errors are fatal, causing the scheduler to exit. The
13848 No errors are fatal.
13851 All of the errors below are fatal.
13854 Browsing initialization errors are fatal, for example failed connections
13855 to the DNS-SD daemon.
13858 Configuration file syntax errors are fatal.
13861 Listen or Port errors are fatal, except for IPv6 failures on the
13862 loopback or @code{any} addresses.
13865 Log file creation or write errors are fatal.
13868 Bad startup file permissions are fatal, for example shared TLS
13869 certificate and key files with world-read permissions.
13872 Defaults to @samp{"all -browse"}.
13875 @deftypevr {@code{files-configuration} parameter} boolean file-device?
13876 Specifies whether the file pseudo-device can be used for new printer
13877 queues. The URI @uref{file:///dev/null} is always allowed.
13879 Defaults to @samp{#f}.
13882 @deftypevr {@code{files-configuration} parameter} string group
13883 Specifies the group name or ID that will be used when executing external
13886 Defaults to @samp{"lp"}.
13889 @deftypevr {@code{files-configuration} parameter} string log-file-perm
13890 Specifies the permissions for all log files that the scheduler writes.
13892 Defaults to @samp{"0644"}.
13895 @deftypevr {@code{files-configuration} parameter} log-location page-log
13896 Defines the page log filename. Specifying a blank filename disables
13897 access log generation. The value @code{stderr} causes log entries to be
13898 sent to the standard error file when the scheduler is running in the
13899 foreground, or to the system log daemon when run in the background. The
13900 value @code{syslog} causes log entries to be sent to the system log
13901 daemon. The server name may be included in filenames using the string
13902 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
13904 Defaults to @samp{"/var/log/cups/page_log"}.
13907 @deftypevr {@code{files-configuration} parameter} string remote-root
13908 Specifies the username that is associated with unauthenticated accesses
13909 by clients claiming to be the root user. The default is @code{remroot}.
13911 Defaults to @samp{"remroot"}.
13914 @deftypevr {@code{files-configuration} parameter} file-name request-root
13915 Specifies the directory that contains print jobs and other HTTP request
13918 Defaults to @samp{"/var/spool/cups"}.
13921 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
13922 Specifies the level of security sandboxing that is applied to print
13923 filters, backends, and other child processes of the scheduler; either
13924 @code{relaxed} or @code{strict}. This directive is currently only
13925 used/supported on macOS.
13927 Defaults to @samp{strict}.
13930 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
13931 Specifies the location of TLS certificates and private keys. CUPS will
13932 look for public and private keys in this directory: a @code{.crt} files
13933 for PEM-encoded certificates and corresponding @code{.key} files for
13934 PEM-encoded private keys.
13936 Defaults to @samp{"/etc/cups/ssl"}.
13939 @deftypevr {@code{files-configuration} parameter} file-name server-root
13940 Specifies the directory containing the server configuration files.
13942 Defaults to @samp{"/etc/cups"}.
13945 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
13946 Specifies whether the scheduler calls fsync(2) after writing
13947 configuration or state files.
13949 Defaults to @samp{#f}.
13952 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
13953 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
13956 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
13957 Specifies the directory where temporary files are stored.
13959 Defaults to @samp{"/var/spool/cups/tmp"}.
13962 @deftypevr {@code{files-configuration} parameter} string user
13963 Specifies the user name or ID that is used when running external
13966 Defaults to @samp{"lp"}.
13970 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
13971 Specifies the logging level for the AccessLog file. The @code{config}
13972 level logs when printers and classes are added, deleted, or modified and
13973 when configuration files are accessed or updated. The @code{actions}
13974 level logs when print jobs are submitted, held, released, modified, or
13975 canceled, and any of the conditions for @code{config}. The @code{all}
13976 level logs all requests.
13978 Defaults to @samp{actions}.
13981 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
13982 Specifies whether to purge job history data automatically when it is no
13983 longer required for quotas.
13985 Defaults to @samp{#f}.
13988 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
13989 Specifies which protocols to use for local printer sharing.
13991 Defaults to @samp{dnssd}.
13994 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
13995 Specifies whether the CUPS web interface is advertised.
13997 Defaults to @samp{#f}.
14000 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
14001 Specifies whether shared printers are advertised.
14003 Defaults to @samp{#f}.
14006 @deftypevr {@code{cups-configuration} parameter} string classification
14007 Specifies the security classification of the server. Any valid banner
14008 name can be used, including "classified", "confidential", "secret",
14009 "topsecret", and "unclassified", or the banner can be omitted to disable
14010 secure printing functions.
14012 Defaults to @samp{""}.
14015 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
14016 Specifies whether users may override the classification (cover page) of
14017 individual print jobs using the @code{job-sheets} option.
14019 Defaults to @samp{#f}.
14022 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
14023 Specifies the default type of authentication to use.
14025 Defaults to @samp{Basic}.
14028 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
14029 Specifies whether encryption will be used for authenticated requests.
14031 Defaults to @samp{Required}.
14034 @deftypevr {@code{cups-configuration} parameter} string default-language
14035 Specifies the default language to use for text and web content.
14037 Defaults to @samp{"en"}.
14040 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
14041 Specifies the default paper size for new print queues. @samp{"Auto"}
14042 uses a locale-specific default, while @samp{"None"} specifies there is
14043 no default paper size. Specific size names are typically
14044 @samp{"Letter"} or @samp{"A4"}.
14046 Defaults to @samp{"Auto"}.
14049 @deftypevr {@code{cups-configuration} parameter} string default-policy
14050 Specifies the default access policy to use.
14052 Defaults to @samp{"default"}.
14055 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
14056 Specifies whether local printers are shared by default.
14058 Defaults to @samp{#t}.
14061 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
14062 Specifies the delay for updating of configuration and state files, in
14063 seconds. A value of 0 causes the update to happen as soon as possible,
14064 typically within a few milliseconds.
14066 Defaults to @samp{30}.
14069 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
14070 Specifies what to do when an error occurs. Possible values are
14071 @code{abort-job}, which will discard the failed print job;
14072 @code{retry-job}, which will retry the job at a later time;
14073 @code{retry-this-job}, which retries the failed job immediately; and
14074 @code{stop-printer}, which stops the printer.
14076 Defaults to @samp{stop-printer}.
14079 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
14080 Specifies the maximum cost of filters that are run concurrently, which
14081 can be used to minimize disk, memory, and CPU resource problems. A
14082 limit of 0 disables filter limiting. An average print to a
14083 non-PostScript printer needs a filter limit of about 200. A PostScript
14084 printer needs about half that (100). Setting the limit below these
14085 thresholds will effectively limit the scheduler to printing a single job
14088 Defaults to @samp{0}.
14091 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
14092 Specifies the scheduling priority of filters that are run to print a
14093 job. The nice value ranges from 0, the highest priority, to 19, the
14096 Defaults to @samp{0}.
14099 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
14100 Specifies whether to do reverse lookups on connecting clients. The
14101 @code{double} setting causes @code{cupsd} to verify that the hostname
14102 resolved from the address matches one of the addresses returned for that
14103 hostname. Double lookups also prevent clients with unregistered
14104 addresses from connecting to your server. Only set this option to
14105 @code{#t} or @code{double} if absolutely required.
14107 Defaults to @samp{#f}.
14110 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
14111 Specifies the number of seconds to wait before killing the filters and
14112 backend associated with a canceled or held job.
14114 Defaults to @samp{30}.
14117 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
14118 Specifies the interval between retries of jobs in seconds. This is
14119 typically used for fax queues but can also be used with normal print
14120 queues whose error policy is @code{retry-job} or
14121 @code{retry-current-job}.
14123 Defaults to @samp{30}.
14126 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
14127 Specifies the number of retries that are done for jobs. This is
14128 typically used for fax queues but can also be used with normal print
14129 queues whose error policy is @code{retry-job} or
14130 @code{retry-current-job}.
14132 Defaults to @samp{5}.
14135 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
14136 Specifies whether to support HTTP keep-alive connections.
14138 Defaults to @samp{#t}.
14141 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
14142 Specifies how long an idle client connection remains open, in seconds.
14144 Defaults to @samp{30}.
14147 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
14148 Specifies the maximum size of print files, IPP requests, and HTML form
14149 data. A limit of 0 disables the limit check.
14151 Defaults to @samp{0}.
14154 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
14155 Listens on the specified interfaces for connections. Valid values are
14156 of the form @var{address}:@var{port}, where @var{address} is either an
14157 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
14158 indicate all addresses. Values can also be file names of local UNIX
14159 domain sockets. The Listen directive is similar to the Port directive
14160 but allows you to restrict access to specific interfaces or networks.
14163 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
14164 Specifies the number of pending connections that will be allowed. This
14165 normally only affects very busy servers that have reached the MaxClients
14166 limit, but can also be triggered by large numbers of simultaneous
14167 connections. When the limit is reached, the operating system will
14168 refuse additional connections until the scheduler can accept the pending
14171 Defaults to @samp{128}.
14174 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
14175 Specifies a set of additional access controls.
14177 Available @code{location-access-controls} fields are:
14179 @deftypevr {@code{location-access-controls} parameter} file-name path
14180 Specifies the URI path to which the access control applies.
14183 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
14184 Access controls for all access to this path, in the same format as the
14185 @code{access-controls} of @code{operation-access-control}.
14187 Defaults to @samp{()}.
14190 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
14191 Access controls for method-specific access to this path.
14193 Defaults to @samp{()}.
14195 Available @code{method-access-controls} fields are:
14197 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
14198 If @code{#t}, apply access controls to all methods except the listed
14199 methods. Otherwise apply to only the listed methods.
14201 Defaults to @samp{#f}.
14204 @deftypevr {@code{method-access-controls} parameter} method-list methods
14205 Methods to which this access control applies.
14207 Defaults to @samp{()}.
14210 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
14211 Access control directives, as a list of strings. Each string should be
14212 one directive, such as "Order allow,deny".
14214 Defaults to @samp{()}.
14219 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
14220 Specifies the number of debugging messages that are retained for logging
14221 if an error occurs in a print job. Debug messages are logged regardless
14222 of the LogLevel setting.
14224 Defaults to @samp{100}.
14227 @deftypevr {@code{cups-configuration} parameter} log-level log-level
14228 Specifies the level of logging for the ErrorLog file. The value
14229 @code{none} stops all logging while @code{debug2} logs everything.
14231 Defaults to @samp{info}.
14234 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
14235 Specifies the format of the date and time in the log files. The value
14236 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
14238 Defaults to @samp{standard}.
14241 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
14242 Specifies the maximum number of simultaneous clients that are allowed by
14245 Defaults to @samp{100}.
14248 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
14249 Specifies the maximum number of simultaneous clients that are allowed
14250 from a single address.
14252 Defaults to @samp{100}.
14255 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
14256 Specifies the maximum number of copies that a user can print of each
14259 Defaults to @samp{9999}.
14262 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
14263 Specifies the maximum time a job may remain in the @code{indefinite}
14264 hold state before it is canceled. A value of 0 disables cancellation of
14267 Defaults to @samp{0}.
14270 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
14271 Specifies the maximum number of simultaneous jobs that are allowed. Set
14272 to 0 to allow an unlimited number of jobs.
14274 Defaults to @samp{500}.
14277 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
14278 Specifies the maximum number of simultaneous jobs that are allowed per
14279 printer. A value of 0 allows up to MaxJobs jobs per printer.
14281 Defaults to @samp{0}.
14284 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
14285 Specifies the maximum number of simultaneous jobs that are allowed per
14286 user. A value of 0 allows up to MaxJobs jobs per user.
14288 Defaults to @samp{0}.
14291 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
14292 Specifies the maximum time a job may take to print before it is
14293 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
14295 Defaults to @samp{10800}.
14298 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
14299 Specifies the maximum size of the log files before they are rotated, in
14300 bytes. The value 0 disables log rotation.
14302 Defaults to @samp{1048576}.
14305 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
14306 Specifies the maximum amount of time to allow between files in a
14307 multiple file print job, in seconds.
14309 Defaults to @samp{300}.
14312 @deftypevr {@code{cups-configuration} parameter} string page-log-format
14313 Specifies the format of PageLog lines. Sequences beginning with percent
14314 (@samp{%}) characters are replaced with the corresponding information,
14315 while all other characters are copied literally. The following percent
14316 sequences are recognized:
14320 insert a single percent character
14323 insert the value of the specified IPP attribute
14326 insert the number of copies for the current page
14329 insert the current page number
14332 insert the current date and time in common log format
14338 insert the printer name
14341 insert the username
14344 A value of the empty string disables page logging. The string @code{%p
14345 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
14346 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
14349 Defaults to @samp{""}.
14352 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
14353 Passes the specified environment variable(s) to child processes; a list
14356 Defaults to @samp{()}.
14359 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
14360 Specifies named access control policies.
14362 Available @code{policy-configuration} fields are:
14364 @deftypevr {@code{policy-configuration} parameter} string name
14365 Name of the policy.
14368 @deftypevr {@code{policy-configuration} parameter} string job-private-access
14369 Specifies an access list for a job's private values. @code{@@ACL} maps
14370 to the printer's requesting-user-name-allowed or
14371 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14372 owner. @code{@@SYSTEM} maps to the groups listed for the
14373 @code{system-group} field of the @code{files-config} configuration,
14374 which is reified into the @code{cups-files.conf(5)} file. Other
14375 possible elements of the access list include specific user names, and
14376 @code{@@@var{group}} to indicate members of a specific group. The
14377 access list may also be simply @code{all} or @code{default}.
14379 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14382 @deftypevr {@code{policy-configuration} parameter} string job-private-values
14383 Specifies the list of job values to make private, or @code{all},
14384 @code{default}, or @code{none}.
14386 Defaults to @samp{"job-name job-originating-host-name
14387 job-originating-user-name phone"}.
14390 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
14391 Specifies an access list for a subscription's private values.
14392 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
14393 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14394 owner. @code{@@SYSTEM} maps to the groups listed for the
14395 @code{system-group} field of the @code{files-config} configuration,
14396 which is reified into the @code{cups-files.conf(5)} file. Other
14397 possible elements of the access list include specific user names, and
14398 @code{@@@var{group}} to indicate members of a specific group. The
14399 access list may also be simply @code{all} or @code{default}.
14401 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14404 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
14405 Specifies the list of job values to make private, or @code{all},
14406 @code{default}, or @code{none}.
14408 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
14409 notify-subscriber-user-name notify-user-data"}.
14412 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
14413 Access control by IPP operation.
14415 Defaults to @samp{()}.
14419 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
14420 Specifies whether job files (documents) are preserved after a job is
14421 printed. If a numeric value is specified, job files are preserved for
14422 the indicated number of seconds after printing. Otherwise a boolean
14423 value applies indefinitely.
14425 Defaults to @samp{86400}.
14428 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
14429 Specifies whether the job history is preserved after a job is printed.
14430 If a numeric value is specified, the job history is preserved for the
14431 indicated number of seconds after printing. If @code{#t}, the job
14432 history is preserved until the MaxJobs limit is reached.
14434 Defaults to @samp{#t}.
14437 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
14438 Specifies the amount of time to wait for job completion before
14439 restarting the scheduler.
14441 Defaults to @samp{30}.
14444 @deftypevr {@code{cups-configuration} parameter} string rip-cache
14445 Specifies the maximum amount of memory to use when converting documents
14446 into bitmaps for a printer.
14448 Defaults to @samp{"128m"}.
14451 @deftypevr {@code{cups-configuration} parameter} string server-admin
14452 Specifies the email address of the server administrator.
14454 Defaults to @samp{"root@@localhost.localdomain"}.
14457 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
14458 The ServerAlias directive is used for HTTP Host header validation when
14459 clients connect to the scheduler from external interfaces. Using the
14460 special name @code{*} can expose your system to known browser-based DNS
14461 rebinding attacks, even when accessing sites through a firewall. If the
14462 auto-discovery of alternate names does not work, we recommend listing
14463 each alternate name with a ServerAlias directive instead of using
14466 Defaults to @samp{*}.
14469 @deftypevr {@code{cups-configuration} parameter} string server-name
14470 Specifies the fully-qualified host name of the server.
14472 Defaults to @samp{"localhost"}.
14475 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
14476 Specifies what information is included in the Server header of HTTP
14477 responses. @code{None} disables the Server header. @code{ProductOnly}
14478 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
14479 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
14480 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
14481 the output of the @code{uname} command. @code{Full} reports @code{CUPS
14482 2.0.0 (@var{uname}) IPP/2.0}.
14484 Defaults to @samp{Minimal}.
14487 @deftypevr {@code{cups-configuration} parameter} string set-env
14488 Set the specified environment variable to be passed to child processes.
14490 Defaults to @samp{"variable value"}.
14493 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
14494 Listens on the specified interfaces for encrypted connections. Valid
14495 values are of the form @var{address}:@var{port}, where @var{address} is
14496 either an IPv6 address enclosed in brackets, an IPv4 address, or
14497 @code{*} to indicate all addresses.
14499 Defaults to @samp{()}.
14502 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
14503 Sets encryption options. By default, CUPS only supports encryption
14504 using TLS v1.0 or higher using known secure cipher suites. The
14505 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
14506 required for some older clients that do not implement newer ones. The
14507 @code{AllowSSL3} option enables SSL v3.0, which is required for some
14508 older clients that do not support TLS v1.0.
14510 Defaults to @samp{()}.
14513 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
14514 Specifies whether the scheduler requires clients to strictly adhere to
14515 the IPP specifications.
14517 Defaults to @samp{#f}.
14520 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
14521 Specifies the HTTP request timeout, in seconds.
14523 Defaults to @samp{300}.
14527 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
14528 Specifies whether the web interface is enabled.
14530 Defaults to @samp{#f}.
14533 At this point you're probably thinking ``oh dear, Guix manual, I like
14534 you but you can stop already with the configuration options''. Indeed.
14535 However, one more point: it could be that you have an existing
14536 @code{cupsd.conf} that you want to use. In that case, you can pass an
14537 @code{opaque-cups-configuration} as the configuration of a
14538 @code{cups-service-type}.
14540 Available @code{opaque-cups-configuration} fields are:
14542 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
14546 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
14547 The contents of the @code{cupsd.conf}, as a string.
14550 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
14551 The contents of the @code{cups-files.conf} file, as a string.
14554 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
14555 strings of the same name, you could instantiate a CUPS service like
14559 (service cups-service-type
14560 (opaque-cups-configuration
14561 (cupsd.conf cupsd.conf)
14562 (cups-files.conf cups-files.conf)))
14566 @node Desktop Services
14567 @subsection Desktop Services
14569 The @code{(gnu services desktop)} module provides services that are
14570 usually useful in the context of a ``desktop'' setup---that is, on a
14571 machine running a graphical display server, possibly with graphical user
14572 interfaces, etc. It also defines services that provide specific desktop
14573 environments like GNOME, Xfce or MATE.
14575 To simplify things, the module defines a variable containing the set of
14576 services that users typically expect on a machine with a graphical
14577 environment and networking:
14579 @defvr {Scheme Variable} %desktop-services
14580 This is a list of services that builds upon @var{%base-services} and
14581 adds or adjusts services for a typical ``desktop'' setup.
14583 In particular, it adds a graphical login manager (@pxref{X Window,
14584 @code{gdm-service-type}}), screen lockers, a network management tool
14585 (@pxref{Networking Services, @code{network-manager-service-type}}), energy and color
14586 management services, the @code{elogind} login and seat manager, the
14587 Polkit privilege service, the GeoClue location service, the
14588 AccountsService daemon that allows authorized users change system
14589 passwords, an NTP client (@pxref{Networking Services}), the Avahi
14590 daemon, and has the name service switch service configured to be able to
14591 use @code{nss-mdns} (@pxref{Name Service Switch, mDNS}).
14594 The @var{%desktop-services} variable can be used as the @code{services}
14595 field of an @code{operating-system} declaration (@pxref{operating-system
14596 Reference, @code{services}}).
14598 Additionally, the @code{gnome-desktop-service-type},
14599 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
14600 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
14601 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
14602 services like the backlight adjustment helpers and the power management
14603 utilities are added to the system, extending @code{polkit} and @code{dbus}
14604 appropriately, allowing GNOME to operate with elevated privileges on a
14605 limited number of special-purpose system interfaces. Additionally,
14606 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
14607 metapackage to the system profile. Likewise, adding the Xfce service
14608 not only adds the @code{xfce} metapackage to the system profile, but it
14609 also gives the Thunar file manager the ability to open a ``root-mode''
14610 file management window, if the user authenticates using the
14611 administrator's password via the standard polkit graphical interface.
14612 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
14613 appropriately, allowing MATE to operate with elevated privileges on a
14614 limited number of special-purpose system interfaces. Additionally,
14615 adding a service of type @code{mate-desktop-service-type} adds the MATE
14616 metapackage to the system profile. ``Adding Enlightenment'' means that
14617 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
14618 are set as setuid, allowing Enlightenment's screen locker and other
14619 functionality to work as expetected.
14621 The desktop environments in Guix use the Xorg display server by
14622 default. If you'd like to use the newer display server protocol
14623 called Wayland, you need to use the @code{sddm-service} instead of
14624 GDM as the graphical login manager. You should then
14625 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
14626 also try starting GNOME on Wayland manually from a TTY with the
14627 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
14628 gnome-session``. Currently only GNOME has support for Wayland.
14630 @defvr {Scheme Variable} gnome-desktop-service-type
14631 This is the type of the service that adds the @uref{https://www.gnome.org,
14632 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
14633 object (see below.)
14635 This service adds the @code{gnome} package to the system profile, and extends
14636 polkit with the actions from @code{gnome-settings-daemon}.
14639 @deftp {Data Type} gnome-desktop-configuration
14640 Configuration record for the GNOME desktop environment.
14643 @item @code{gnome} (default @code{gnome})
14644 The GNOME package to use.
14648 @defvr {Scheme Variable} xfce-desktop-service-type
14649 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
14650 desktop environment. Its value is an @code{xfce-desktop-configuration} object
14653 This service that adds the @code{xfce} package to the system profile, and
14654 extends polkit with the ability for @code{thunar} to manipulate the file
14655 system as root from within a user session, after the user has authenticated
14656 with the administrator's password.
14659 @deftp {Data Type} xfce-desktop-configuration
14660 Configuration record for the Xfce desktop environment.
14663 @item @code{xfce} (default @code{xfce})
14664 The Xfce package to use.
14668 @deffn {Scheme Variable} mate-desktop-service-type
14669 This is the type of the service that runs the @uref{https://mate-desktop.org/,
14670 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
14671 object (see below.)
14673 This service adds the @code{mate} package to the system
14674 profile, and extends polkit with the actions from
14675 @code{mate-settings-daemon}.
14678 @deftp {Data Type} mate-desktop-configuration
14679 Configuration record for the MATE desktop environment.
14682 @item @code{mate} (default @code{mate})
14683 The MATE package to use.
14687 @deffn {Scheme Variable} enlightenment-desktop-service-type
14688 Return a service that adds the @code{enlightenment} package to the system
14689 profile, and extends dbus with actions from @code{efl}.
14692 @deftp {Data Type} enlightenment-desktop-service-configuration
14694 @item @code{enlightenment} (default @code{enlightenment})
14695 The enlightenment package to use.
14699 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
14700 the default @code{%desktop-services} variable doesn't include any of
14701 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
14702 @code{%desktop-services} in the @code{services} field of your
14703 @code{operating-system}:
14706 (use-modules (gnu))
14707 (use-service-modules desktop)
14710 ;; cons* adds items to the list given as its last argument.
14711 (services (cons* (service gnome-desktop-service-type)
14712 (service xfce-desktop-service)
14713 %desktop-services))
14717 These desktop environments will then be available as options in the
14718 graphical login window.
14720 The actual service definitions included in @code{%desktop-services} and
14721 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
14722 are described below.
14724 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
14725 Return a service that runs the ``system bus'', using @var{dbus}, with
14726 support for @var{services}.
14728 @uref{http://dbus.freedesktop.org/, D-Bus} is an inter-process communication
14729 facility. Its system bus is used to allow system services to communicate
14730 and to be notified of system-wide events.
14732 @var{services} must be a list of packages that provide an
14733 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
14734 and policy files. For example, to allow avahi-daemon to use the system bus,
14735 @var{services} must be equal to @code{(list avahi)}.
14738 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
14739 Return a service that runs the @code{elogind} login and
14740 seat management daemon. @uref{https://github.com/elogind/elogind,
14741 Elogind} exposes a D-Bus interface that can be used to know which users
14742 are logged in, know what kind of sessions they have open, suspend the
14743 system, inhibit system suspend, reboot the system, and other tasks.
14745 Elogind handles most system-level power events for a computer, for
14746 example suspending the system when a lid is closed, or shutting it down
14747 when the power button is pressed.
14749 The @var{config} keyword argument specifies the configuration for
14750 elogind, and should be the result of an @code{(elogind-configuration
14751 (@var{parameter} @var{value})...)} invocation. Available parameters and
14752 their default values are:
14755 @item kill-user-processes?
14757 @item kill-only-users
14759 @item kill-exclude-users
14761 @item inhibit-delay-max-seconds
14763 @item handle-power-key
14765 @item handle-suspend-key
14767 @item handle-hibernate-key
14769 @item handle-lid-switch
14771 @item handle-lid-switch-docked
14773 @item power-key-ignore-inhibited?
14775 @item suspend-key-ignore-inhibited?
14777 @item hibernate-key-ignore-inhibited?
14779 @item lid-switch-ignore-inhibited?
14781 @item holdoff-timeout-seconds
14785 @item idle-action-seconds
14787 @item runtime-directory-size-percent
14789 @item runtime-directory-size
14793 @item suspend-state
14794 @code{("mem" "standby" "freeze")}
14797 @item hibernate-state
14799 @item hibernate-mode
14800 @code{("platform" "shutdown")}
14801 @item hybrid-sleep-state
14803 @item hybrid-sleep-mode
14804 @code{("suspend" "platform" "shutdown")}
14808 @deffn {Scheme Procedure} accountsservice-service @
14809 [#:accountsservice @var{accountsservice}]
14810 Return a service that runs AccountsService, a system service that can
14811 list available accounts, change their passwords, and so on.
14812 AccountsService integrates with PolicyKit to enable unprivileged users
14813 to acquire the capability to modify their system configuration.
14814 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
14815 accountsservice web site} for more information.
14817 The @var{accountsservice} keyword argument is the @code{accountsservice}
14818 package to expose as a service.
14821 @deffn {Scheme Procedure} polkit-service @
14822 [#:polkit @var{polkit}]
14823 Return a service that runs the
14824 @uref{http://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
14825 management service}, which allows system administrators to grant access to
14826 privileged operations in a structured way. By querying the Polkit service, a
14827 privileged system component can know when it should grant additional
14828 capabilities to ordinary users. For example, an ordinary user can be granted
14829 the capability to suspend the system if the user is logged in locally.
14832 @defvr {Scheme Variable} upower-service-type
14833 Service that runs @uref{http://upower.freedesktop.org/, @command{upowerd}}, a
14834 system-wide monitor for power consumption and battery levels, with the given
14835 configuration settings.
14837 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
14838 notably used by GNOME.
14841 @deftp {Data Type} upower-configuration
14842 Data type representation the configuration for UPower.
14846 @item @code{upower} (default: @var{upower})
14847 Package to use for @code{upower}.
14849 @item @code{watts-up-pro?} (default: @code{#f})
14850 Enable the Watts Up Pro device.
14852 @item @code{poll-batteries?} (default: @code{#t})
14853 Enable polling the kernel for battery level changes.
14855 @item @code{ignore-lid?} (default: @code{#f})
14856 Ignore the lid state, this can be useful if it's incorrect on a device.
14858 @item @code{use-percentage-for-policy?} (default: @code{#f})
14859 Whether battery percentage based policy should be used. The default is to use
14860 the time left, change to @code{#t} to use the percentage.
14862 @item @code{percentage-low} (default: @code{10})
14863 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14864 at which the battery is considered low.
14866 @item @code{percentage-critical} (default: @code{3})
14867 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14868 at which the battery is considered critical.
14870 @item @code{percentage-action} (default: @code{2})
14871 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14872 at which action will be taken.
14874 @item @code{time-low} (default: @code{1200})
14875 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14876 seconds at which the battery is considered low.
14878 @item @code{time-critical} (default: @code{300})
14879 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14880 seconds at which the battery is considered critical.
14882 @item @code{time-action} (default: @code{120})
14883 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14884 seconds at which action will be taken.
14886 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
14887 The action taken when @code{percentage-action} or @code{time-action} is
14888 reached (depending on the configuration of @code{use-percentage-for-policy?}).
14890 Possible values are:
14900 @code{'hybrid-sleep}.
14906 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
14907 Return a service for @uref{http://udisks.freedesktop.org/docs/latest/,
14908 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
14909 notifications and ways to mount/unmount disks. Programs that talk to UDisks
14910 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
14913 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
14914 Return a service that runs @command{colord}, a system service with a D-Bus
14915 interface to manage the color profiles of input and output devices such as
14916 screens and scanners. It is notably used by the GNOME Color Manager graphical
14917 tool. See @uref{http://www.freedesktop.org/software/colord/, the colord web
14918 site} for more information.
14921 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
14922 Return a configuration allowing an application to access GeoClue
14923 location data. @var{name} is the Desktop ID of the application, without
14924 the @code{.desktop} part. If @var{allowed?} is true, the application
14925 will have access to location information by default. The boolean
14926 @var{system?} value indicates whether an application is a system component
14927 or not. Finally @var{users} is a list of UIDs of all users for which
14928 this application is allowed location info access. An empty users list
14929 means that all users are allowed.
14932 @defvr {Scheme Variable} %standard-geoclue-applications
14933 The standard list of well-known GeoClue application configurations,
14934 granting authority to the GNOME date-and-time utility to ask for the
14935 current location in order to set the time zone, and allowing the
14936 IceCat and Epiphany web browsers to request location information.
14937 IceCat and Epiphany both query the user before allowing a web page to
14938 know the user's location.
14941 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
14942 [#:whitelist '()] @
14943 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
14944 [#:submit-data? #f]
14945 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
14946 [#:submission-nick "geoclue"] @
14947 [#:applications %standard-geoclue-applications]
14948 Return a service that runs the GeoClue location service. This service
14949 provides a D-Bus interface to allow applications to request access to a
14950 user's physical location, and optionally to add information to online
14951 location databases. See
14952 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
14953 web site} for more information.
14956 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
14957 [@w{#:auto-enable? #f}]
14958 Return a service that runs the @command{bluetoothd} daemon, which
14959 manages all the Bluetooth devices and provides a number of D-Bus
14960 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
14961 powered automatically at boot, which can be useful when using a
14962 bluetooth keyboard or mouse.
14964 Users need to be in the @code{lp} group to access the D-Bus service.
14967 @node Sound Services
14968 @subsection Sound Services
14970 @cindex sound support
14972 @cindex PulseAudio, sound support
14974 The @code{(gnu services sound)} module provides a service to configure the
14975 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
14976 preferred ALSA output driver.
14978 @deffn {Scheme Variable} alsa-service-type
14979 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
14980 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
14981 configuration file. The value for this type is a @command{alsa-configuration}
14982 record as in this example:
14985 (service alsa-service-type)
14988 See below for details about @code{alsa-configuration}.
14991 @deftp {Data Type} alsa-configuration
14992 Data type representing the configuration for @code{alsa-service}.
14995 @item @code{alsa-plugins} (default: @var{alsa-plugins})
14996 @code{alsa-plugins} package to use.
14998 @item @code{pulseaudio?} (default: @var{#t})
14999 Whether ALSA applications should transparently be made to use the
15000 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
15002 Using PulseAudio allows you to run several sound-producing applications
15003 at the same time and to individual control them @i{via}
15004 @command{pavucontrol}, among other things.
15006 @item @code{extra-options} (default: @var{""})
15007 String to append to the @file{/etc/asound.conf} file.
15012 Individual users who want to override the system configuration of ALSA can do
15013 it with the @file{~/.asoundrc} file:
15016 # In guix, we have to specify the absolute path for plugins.
15018 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
15021 # Routing ALSA to jack:
15022 # <http://jackaudio.org/faq/routing_alsa.html>.
15026 0 system:playback_1
15027 1 system:playback_2
15044 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
15048 @node Database Services
15049 @subsection Database Services
15053 The @code{(gnu services databases)} module provides the following services.
15055 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
15056 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
15057 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
15058 Return a service that runs @var{postgresql}, the PostgreSQL database
15061 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
15062 creates a database cluster with @var{locale} as the default
15063 locale, stored in @var{data-directory}. It then listens on @var{port}.
15065 @cindex postgresql extension-packages
15066 Additional extensions are loaded from packages listed in
15067 @var{extension-packages}. Extensions are available at runtime. For instance,
15068 to create a geographic database using the @code{postgis} extension, a user can
15069 configure the postgresql-service as in this example:
15073 (use-package-modules databases geo)
15077 ;; postgresql is required to run `psql' but postgis is not required for
15078 ;; proper operation.
15079 (packages (cons* postgresql %base-packages))
15082 (postgresql-service #:extension-packages (list postgis))
15086 Then the extension becomes visible and you can initialise an empty geographic
15087 database in this way:
15091 > create database postgistest;
15092 > \connect postgistest;
15093 > create extension postgis;
15094 > create extension postgis_topology;
15097 There is no need to add this field for contrib extensions such as hstore or
15098 dblink as they are already loadable by postgresql. This field is only
15099 required to add extensions provided by other packages.
15102 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
15103 Return a service that runs @command{mysqld}, the MySQL or MariaDB
15106 The optional @var{config} argument specifies the configuration for
15107 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
15110 @deftp {Data Type} mysql-configuration
15111 Data type representing the configuration of @var{mysql-service}.
15114 @item @code{mysql} (default: @var{mariadb})
15115 Package object of the MySQL database server, can be either @var{mariadb}
15118 For MySQL, a temporary root password will be displayed at activation time.
15119 For MariaDB, the root password is empty.
15121 @item @code{port} (default: @code{3306})
15122 TCP port on which the database server listens for incoming connections.
15126 @defvr {Scheme Variable} memcached-service-type
15127 This is the service type for the @uref{https://memcached.org/,
15128 Memcached} service, which provides a distributed in memory cache. The
15129 value for the service type is a @code{memcached-configuration} object.
15133 (service memcached-service-type)
15136 @deftp {Data Type} memcached-configuration
15137 Data type representing the configuration of memcached.
15140 @item @code{memcached} (default: @code{memcached})
15141 The Memcached package to use.
15143 @item @code{interfaces} (default: @code{'("0.0.0.0")})
15144 Network interfaces on which to listen.
15146 @item @code{tcp-port} (default: @code{11211})
15147 Port on which to accept connections on,
15149 @item @code{udp-port} (default: @code{11211})
15150 Port on which to accept UDP connections on, a value of 0 will disable
15151 listening on a UDP socket.
15153 @item @code{additional-options} (default: @code{'()})
15154 Additional command line options to pass to @code{memcached}.
15158 @defvr {Scheme Variable} mongodb-service-type
15159 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
15160 The value for the service type is a @code{mongodb-configuration} object.
15164 (service mongodb-service-type)
15167 @deftp {Data Type} mongodb-configuration
15168 Data type representing the configuration of mongodb.
15171 @item @code{mongodb} (default: @code{mongodb})
15172 The MongoDB package to use.
15174 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
15175 The configuration file for MongoDB.
15177 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
15178 This value is used to create the directory, so that it exists and is
15179 owned by the mongodb user. It should match the data-directory which
15180 MongoDB is configured to use through the configuration file.
15184 @defvr {Scheme Variable} redis-service-type
15185 This is the service type for the @uref{https://redis.io/, Redis}
15186 key/value store, whose value is a @code{redis-configuration} object.
15189 @deftp {Data Type} redis-configuration
15190 Data type representing the configuration of redis.
15193 @item @code{redis} (default: @code{redis})
15194 The Redis package to use.
15196 @item @code{bind} (default: @code{"127.0.0.1"})
15197 Network interface on which to listen.
15199 @item @code{port} (default: @code{6379})
15200 Port on which to accept connections on, a value of 0 will disable
15201 listening on a TCP socket.
15203 @item @code{working-directory} (default: @code{"/var/lib/redis"})
15204 Directory in which to store the database and related files.
15208 @node Mail Services
15209 @subsection Mail Services
15213 The @code{(gnu services mail)} module provides Guix service definitions
15214 for email services: IMAP, POP3, and LMTP servers, as well as mail
15215 transport agents (MTAs). Lots of acronyms! These services are detailed
15216 in the subsections below.
15218 @subsubheading Dovecot Service
15220 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
15221 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
15224 By default, Dovecot does not need much configuration; the default
15225 configuration object created by @code{(dovecot-configuration)} will
15226 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
15227 certificate will be generated for TLS-protected connections, though
15228 Dovecot will also listen on cleartext ports by default. There are a
15229 number of options, though, which mail administrators might need to change,
15230 and as is the case with other services, Guix allows the system
15231 administrator to specify these parameters via a uniform Scheme interface.
15233 For example, to specify that mail is located at @code{maildir~/.mail},
15234 one would instantiate the Dovecot service like this:
15237 (dovecot-service #:config
15238 (dovecot-configuration
15239 (mail-location "maildir:~/.mail")))
15242 The available configuration parameters follow. Each parameter
15243 definition is preceded by its type; for example, @samp{string-list foo}
15244 indicates that the @code{foo} parameter should be specified as a list of
15245 strings. There is also a way to specify the configuration as a string,
15246 if you have an old @code{dovecot.conf} file that you want to port over
15247 from some other system; see the end for more details.
15249 @c The following documentation was initially generated by
15250 @c (generate-documentation) in (gnu services mail). Manually maintained
15251 @c documentation is better, so we shouldn't hesitate to edit below as
15252 @c needed. However if the change you want to make to this documentation
15253 @c can be done in an automated way, it's probably easier to change
15254 @c (generate-documentation) than to make it below and have to deal with
15255 @c the churn as dovecot updates.
15257 Available @code{dovecot-configuration} fields are:
15259 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
15260 The dovecot package.
15263 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
15264 A list of IPs or hosts where to listen for connections. @samp{*}
15265 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
15266 interfaces. If you want to specify non-default ports or anything more
15267 complex, customize the address and port fields of the
15268 @samp{inet-listener} of the specific services you are interested in.
15271 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
15272 List of protocols we want to serve. Available protocols include
15273 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
15275 Available @code{protocol-configuration} fields are:
15277 @deftypevr {@code{protocol-configuration} parameter} string name
15278 The name of the protocol.
15281 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
15282 UNIX socket path to the master authentication server to find users.
15283 This is used by imap (for shared users) and lda.
15284 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
15287 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
15288 Space separated list of plugins to load.
15291 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
15292 Maximum number of IMAP connections allowed for a user from each IP
15293 address. NOTE: The username is compared case-sensitively.
15294 Defaults to @samp{10}.
15299 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
15300 List of services to enable. Available services include @samp{imap},
15301 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
15304 Available @code{service-configuration} fields are:
15306 @deftypevr {@code{service-configuration} parameter} string kind
15307 The service kind. Valid values include @code{director},
15308 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
15309 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
15310 @code{tcpwrap}, @code{quota-warning}, or anything else.
15313 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
15314 Listeners for the service. A listener is either a
15315 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
15316 an @code{inet-listener-configuration}.
15317 Defaults to @samp{()}.
15319 Available @code{unix-listener-configuration} fields are:
15321 @deftypevr {@code{unix-listener-configuration} parameter} string path
15322 Path to the file, relative to @code{base-dir} field. This is also used as
15326 @deftypevr {@code{unix-listener-configuration} parameter} string mode
15327 The access mode for the socket.
15328 Defaults to @samp{"0600"}.
15331 @deftypevr {@code{unix-listener-configuration} parameter} string user
15332 The user to own the socket.
15333 Defaults to @samp{""}.
15336 @deftypevr {@code{unix-listener-configuration} parameter} string group
15337 The group to own the socket.
15338 Defaults to @samp{""}.
15342 Available @code{fifo-listener-configuration} fields are:
15344 @deftypevr {@code{fifo-listener-configuration} parameter} string path
15345 Path to the file, relative to @code{base-dir} field. This is also used as
15349 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
15350 The access mode for the socket.
15351 Defaults to @samp{"0600"}.
15354 @deftypevr {@code{fifo-listener-configuration} parameter} string user
15355 The user to own the socket.
15356 Defaults to @samp{""}.
15359 @deftypevr {@code{fifo-listener-configuration} parameter} string group
15360 The group to own the socket.
15361 Defaults to @samp{""}.
15365 Available @code{inet-listener-configuration} fields are:
15367 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
15368 The protocol to listen for.
15371 @deftypevr {@code{inet-listener-configuration} parameter} string address
15372 The address on which to listen, or empty for all addresses.
15373 Defaults to @samp{""}.
15376 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
15377 The port on which to listen.
15380 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
15381 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
15383 Defaults to @samp{#t}.
15388 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
15389 Maximum number of simultaneous client connections per process. Once
15390 this number of connections is received, the next incoming connection
15391 will prompt Dovecot to spawn another process. If set to 0,
15392 @code{default-client-limit} is used instead.
15394 Defaults to @samp{0}.
15398 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
15399 Number of connections to handle before starting a new process.
15400 Typically the only useful values are 0 (unlimited) or 1. 1 is more
15401 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
15402 Defaults to @samp{1}.
15406 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
15407 Maximum number of processes that can exist for this service. If set to
15408 0, @code{default-process-limit} is used instead.
15410 Defaults to @samp{0}.
15414 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
15415 Number of processes to always keep waiting for more connections.
15416 Defaults to @samp{0}.
15419 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
15420 If you set @samp{service-count 0}, you probably need to grow
15422 Defaults to @samp{256000000}.
15427 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
15428 Dict configuration, as created by the @code{dict-configuration}
15431 Available @code{dict-configuration} fields are:
15433 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
15434 A list of key-value pairs that this dict should hold.
15435 Defaults to @samp{()}.
15440 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
15441 A list of passdb configurations, each one created by the
15442 @code{passdb-configuration} constructor.
15444 Available @code{passdb-configuration} fields are:
15446 @deftypevr {@code{passdb-configuration} parameter} string driver
15447 The driver that the passdb should use. Valid values include
15448 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
15450 Defaults to @samp{"pam"}.
15453 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
15454 Space separated list of arguments to the passdb driver.
15455 Defaults to @samp{""}.
15460 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
15461 List of userdb configurations, each one created by the
15462 @code{userdb-configuration} constructor.
15464 Available @code{userdb-configuration} fields are:
15466 @deftypevr {@code{userdb-configuration} parameter} string driver
15467 The driver that the userdb should use. Valid values include
15468 @samp{passwd} and @samp{static}.
15469 Defaults to @samp{"passwd"}.
15472 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
15473 Space separated list of arguments to the userdb driver.
15474 Defaults to @samp{""}.
15477 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
15478 Override fields from passwd.
15479 Defaults to @samp{()}.
15484 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
15485 Plug-in configuration, created by the @code{plugin-configuration}
15489 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
15490 List of namespaces. Each item in the list is created by the
15491 @code{namespace-configuration} constructor.
15493 Available @code{namespace-configuration} fields are:
15495 @deftypevr {@code{namespace-configuration} parameter} string name
15496 Name for this namespace.
15499 @deftypevr {@code{namespace-configuration} parameter} string type
15500 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
15501 Defaults to @samp{"private"}.
15504 @deftypevr {@code{namespace-configuration} parameter} string separator
15505 Hierarchy separator to use. You should use the same separator for
15506 all namespaces or some clients get confused. @samp{/} is usually a good
15507 one. The default however depends on the underlying mail storage
15509 Defaults to @samp{""}.
15512 @deftypevr {@code{namespace-configuration} parameter} string prefix
15513 Prefix required to access this namespace. This needs to be
15514 different for all namespaces. For example @samp{Public/}.
15515 Defaults to @samp{""}.
15518 @deftypevr {@code{namespace-configuration} parameter} string location
15519 Physical location of the mailbox. This is in the same format as
15520 mail_location, which is also the default for it.
15521 Defaults to @samp{""}.
15524 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
15525 There can be only one INBOX, and this setting defines which
15527 Defaults to @samp{#f}.
15530 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
15531 If namespace is hidden, it's not advertised to clients via NAMESPACE
15532 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
15533 useful when converting from another server with different namespaces
15534 which you want to deprecate but still keep working. For example you can
15535 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
15537 Defaults to @samp{#f}.
15540 @deftypevr {@code{namespace-configuration} parameter} boolean list?
15541 Show the mailboxes under this namespace with the LIST command. This
15542 makes the namespace visible for clients that do not support the NAMESPACE
15543 extension. The special @code{children} value lists child mailboxes, but
15544 hides the namespace prefix.
15545 Defaults to @samp{#t}.
15548 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
15549 Namespace handles its own subscriptions. If set to @code{#f}, the
15550 parent namespace handles them. The empty prefix should always have this
15552 Defaults to @samp{#t}.
15555 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
15556 List of predefined mailboxes in this namespace.
15557 Defaults to @samp{()}.
15559 Available @code{mailbox-configuration} fields are:
15561 @deftypevr {@code{mailbox-configuration} parameter} string name
15562 Name for this mailbox.
15565 @deftypevr {@code{mailbox-configuration} parameter} string auto
15566 @samp{create} will automatically create this mailbox.
15567 @samp{subscribe} will both create and subscribe to the mailbox.
15568 Defaults to @samp{"no"}.
15571 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
15572 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
15573 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
15574 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
15575 Defaults to @samp{()}.
15582 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
15583 Base directory where to store runtime data.
15584 Defaults to @samp{"/var/run/dovecot/"}.
15587 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
15588 Greeting message for clients.
15589 Defaults to @samp{"Dovecot ready."}.
15592 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
15593 List of trusted network ranges. Connections from these IPs are
15594 allowed to override their IP addresses and ports (for logging and for
15595 authentication checks). @samp{disable-plaintext-auth} is also ignored
15596 for these networks. Typically you would specify your IMAP proxy servers
15598 Defaults to @samp{()}.
15601 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
15602 List of login access check sockets (e.g.@: tcpwrap).
15603 Defaults to @samp{()}.
15606 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
15607 Show more verbose process titles (in ps). Currently shows user name
15608 and IP address. Useful for seeing who is actually using the IMAP
15609 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
15611 Defaults to @samp{#f}.
15614 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
15615 Should all processes be killed when Dovecot master process shuts down.
15616 Setting this to @code{#f} means that Dovecot can be upgraded without
15617 forcing existing client connections to close (although that could also
15618 be a problem if the upgrade is e.g.@: due to a security fix).
15619 Defaults to @samp{#t}.
15622 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
15623 If non-zero, run mail commands via this many connections to doveadm
15624 server, instead of running them directly in the same process.
15625 Defaults to @samp{0}.
15628 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
15629 UNIX socket or host:port used for connecting to doveadm server.
15630 Defaults to @samp{"doveadm-server"}.
15633 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
15634 List of environment variables that are preserved on Dovecot startup
15635 and passed down to all of its child processes. You can also give
15636 key=value pairs to always set specific settings.
15639 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
15640 Disable LOGIN command and all other plaintext authentications unless
15641 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
15642 matches the local IP (i.e.@: you're connecting from the same computer),
15643 the connection is considered secure and plaintext authentication is
15644 allowed. See also ssl=required setting.
15645 Defaults to @samp{#t}.
15648 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
15649 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
15650 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
15651 for caching to be used.
15652 Defaults to @samp{0}.
15655 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
15656 Time to live for cached data. After TTL expires the cached record
15657 is no longer used, *except* if the main database lookup returns internal
15658 failure. We also try to handle password changes automatically: If
15659 user's previous authentication was successful, but this one wasn't, the
15660 cache isn't used. For now this works only with plaintext
15662 Defaults to @samp{"1 hour"}.
15665 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
15666 TTL for negative hits (user not found, password mismatch).
15667 0 disables caching them completely.
15668 Defaults to @samp{"1 hour"}.
15671 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
15672 List of realms for SASL authentication mechanisms that need them.
15673 You can leave it empty if you don't want to support multiple realms.
15674 Many clients simply use the first one listed here, so keep the default
15676 Defaults to @samp{()}.
15679 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
15680 Default realm/domain to use if none was specified. This is used for
15681 both SASL realms and appending @@domain to username in plaintext
15683 Defaults to @samp{""}.
15686 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
15687 List of allowed characters in username. If the user-given username
15688 contains a character not listed in here, the login automatically fails.
15689 This is just an extra check to make sure user can't exploit any
15690 potential quote escaping vulnerabilities with SQL/LDAP databases. If
15691 you want to allow all characters, set this value to empty.
15692 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
15695 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
15696 Username character translations before it's looked up from
15697 databases. The value contains series of from -> to characters. For
15698 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
15699 translated to @samp{@@}.
15700 Defaults to @samp{""}.
15703 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
15704 Username formatting before it's looked up from databases. You can
15705 use the standard variables here, e.g.@: %Lu would lowercase the username,
15706 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
15707 change the @samp{@@} into @samp{-AT-}. This translation is done after
15708 @samp{auth-username-translation} changes.
15709 Defaults to @samp{"%Lu"}.
15712 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
15713 If you want to allow master users to log in by specifying the master
15714 username within the normal username string (i.e.@: not using SASL
15715 mechanism's support for it), you can specify the separator character
15716 here. The format is then <username><separator><master username>.
15717 UW-IMAP uses @samp{*} as the separator, so that could be a good
15719 Defaults to @samp{""}.
15722 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
15723 Username to use for users logging in with ANONYMOUS SASL
15725 Defaults to @samp{"anonymous"}.
15728 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
15729 Maximum number of dovecot-auth worker processes. They're used to
15730 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
15731 They're automatically created and destroyed as needed.
15732 Defaults to @samp{30}.
15735 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
15736 Host name to use in GSSAPI principal names. The default is to use
15737 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
15738 allow all keytab entries.
15739 Defaults to @samp{""}.
15742 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
15743 Kerberos keytab to use for the GSSAPI mechanism. Will use the
15744 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
15745 need to change the auth service to run as root to be able to read this
15747 Defaults to @samp{""}.
15750 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
15751 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
15752 and @samp{ntlm-auth} helper.
15753 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
15754 Defaults to @samp{#f}.
15757 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
15758 Path for Samba's @samp{ntlm-auth} helper binary.
15759 Defaults to @samp{"/usr/bin/ntlm_auth"}.
15762 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
15763 Time to delay before replying to failed authentications.
15764 Defaults to @samp{"2 secs"}.
15767 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
15768 Require a valid SSL client certificate or the authentication
15770 Defaults to @samp{#f}.
15773 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
15774 Take the username from client's SSL certificate, using
15775 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
15777 Defaults to @samp{#f}.
15780 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
15781 List of wanted authentication mechanisms. Supported mechanisms are:
15782 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
15783 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
15784 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
15785 @samp{disable-plaintext-auth} setting.
15788 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
15789 List of IPs or hostnames to all director servers, including ourself.
15790 Ports can be specified as ip:port. The default port is the same as what
15791 director service's @samp{inet-listener} is using.
15792 Defaults to @samp{()}.
15795 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
15796 List of IPs or hostnames to all backend mail servers. Ranges are
15797 allowed too, like 10.0.0.10-10.0.0.30.
15798 Defaults to @samp{()}.
15801 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
15802 How long to redirect users to a specific server after it no longer
15803 has any connections.
15804 Defaults to @samp{"15 min"}.
15807 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
15808 How the username is translated before being hashed. Useful values
15809 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
15810 are shared within domain.
15811 Defaults to @samp{"%Lu"}.
15814 @deftypevr {@code{dovecot-configuration} parameter} string log-path
15815 Log file to use for error messages. @samp{syslog} logs to syslog,
15816 @samp{/dev/stderr} logs to stderr.
15817 Defaults to @samp{"syslog"}.
15820 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
15821 Log file to use for informational messages. Defaults to
15823 Defaults to @samp{""}.
15826 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
15827 Log file to use for debug messages. Defaults to
15828 @samp{info-log-path}.
15829 Defaults to @samp{""}.
15832 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
15833 Syslog facility to use if you're logging to syslog. Usually if you
15834 don't want to use @samp{mail}, you'll use local0..local7. Also other
15835 standard facilities are supported.
15836 Defaults to @samp{"mail"}.
15839 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
15840 Log unsuccessful authentication attempts and the reasons why they
15842 Defaults to @samp{#f}.
15845 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose-passwords?
15846 In case of password mismatches, log the attempted password. Valid
15847 values are no, plain and sha1. sha1 can be useful for detecting brute
15848 force password attempts vs. user simply trying the same password over
15849 and over again. You can also truncate the value to n chars by appending
15850 ":n" (e.g.@: sha1:6).
15851 Defaults to @samp{#f}.
15854 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
15855 Even more verbose logging for debugging purposes. Shows for example
15857 Defaults to @samp{#f}.
15860 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
15861 In case of password mismatches, log the passwords and used scheme so
15862 the problem can be debugged. Enabling this also enables
15864 Defaults to @samp{#f}.
15867 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
15868 Enable mail process debugging. This can help you figure out why
15869 Dovecot isn't finding your mails.
15870 Defaults to @samp{#f}.
15873 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
15874 Show protocol level SSL errors.
15875 Defaults to @samp{#f}.
15878 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
15879 Prefix for each line written to log file. % codes are in
15880 strftime(3) format.
15881 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
15884 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
15885 List of elements we want to log. The elements which have a
15886 non-empty variable value are joined together to form a comma-separated
15890 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
15891 Login log format. %s contains @samp{login-log-format-elements}
15892 string, %$ contains the data we want to log.
15893 Defaults to @samp{"%$: %s"}.
15896 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
15897 Log prefix for mail processes. See doc/wiki/Variables.txt for list
15898 of possible variables you can use.
15899 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
15902 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
15903 Format to use for logging mail deliveries. You can use variables:
15906 Delivery status message (e.g.@: @samp{saved to INBOX})
15918 Defaults to @samp{"msgid=%m: %$"}.
15921 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
15922 Location for users' mailboxes. The default is empty, which means
15923 that Dovecot tries to find the mailboxes automatically. This won't work
15924 if the user doesn't yet have any mail, so you should explicitly tell
15925 Dovecot the full location.
15927 If you're using mbox, giving a path to the INBOX
15928 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
15929 where the other mailboxes are kept. This is called the "root mail
15930 directory", and it must be the first path given in the
15931 @samp{mail-location} setting.
15933 There are a few special variables you can use, eg.:
15939 user part in user@@domain, same as %u if there's no domain
15941 domain part in user@@domain, empty if there's no domain
15946 See doc/wiki/Variables.txt for full list. Some examples:
15948 @item maildir:~/Maildir
15949 @item mbox:~/mail:INBOX=/var/mail/%u
15950 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
15952 Defaults to @samp{""}.
15955 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
15956 System user and group used to access mails. If you use multiple,
15957 userdb can override these by returning uid or gid fields. You can use
15958 either numbers or names. <doc/wiki/UserIds.txt>.
15959 Defaults to @samp{""}.
15962 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
15964 Defaults to @samp{""}.
15967 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
15968 Group to enable temporarily for privileged operations. Currently
15969 this is used only with INBOX when either its initial creation or
15970 dotlocking fails. Typically this is set to "mail" to give access to
15972 Defaults to @samp{""}.
15975 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
15976 Grant access to these supplementary groups for mail processes.
15977 Typically these are used to set up access to shared mailboxes. Note
15978 that it may be dangerous to set these if users can create
15979 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
15980 could allow a user to delete others' mailboxes, or ln -s
15981 /secret/shared/box ~/mail/mybox would allow reading it).
15982 Defaults to @samp{""}.
15985 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
15986 Allow full file system access to clients. There's no access checks
15987 other than what the operating system does for the active UID/GID. It
15988 works with both maildir and mboxes, allowing you to prefix mailboxes
15989 names with e.g.@: /path/ or ~user/.
15990 Defaults to @samp{#f}.
15993 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
15994 Don't use mmap() at all. This is required if you store indexes to
15995 shared file systems (NFS or clustered file system).
15996 Defaults to @samp{#f}.
15999 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
16000 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
16001 supports @samp{O_EXCL} since version 3, so this should be safe to use
16002 nowadays by default.
16003 Defaults to @samp{#t}.
16006 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
16007 When to use fsync() or fdatasync() calls:
16010 Whenever necessary to avoid losing important data
16012 Useful with e.g.@: NFS when write()s are delayed
16014 Never use it (best performance, but crashes can lose data).
16016 Defaults to @samp{"optimized"}.
16019 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
16020 Mail storage exists in NFS. Set this to yes to make Dovecot flush
16021 NFS caches whenever needed. If you're using only a single mail server
16023 Defaults to @samp{#f}.
16026 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
16027 Mail index files also exist in NFS. Setting this to yes requires
16028 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
16029 Defaults to @samp{#f}.
16032 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
16033 Locking method for index files. Alternatives are fcntl, flock and
16034 dotlock. Dotlocking uses some tricks which may create more disk I/O
16035 than other locking methods. NFS users: flock doesn't work, remember to
16036 change @samp{mmap-disable}.
16037 Defaults to @samp{"fcntl"}.
16040 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
16041 Directory in which LDA/LMTP temporarily stores incoming mails >128
16043 Defaults to @samp{"/tmp"}.
16046 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
16047 Valid UID range for users. This is mostly to make sure that users can't
16048 log in as daemons or other system users. Note that denying root logins is
16049 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
16051 Defaults to @samp{500}.
16054 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
16056 Defaults to @samp{0}.
16059 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
16060 Valid GID range for users. Users having non-valid GID as primary group ID
16061 aren't allowed to log in. If user belongs to supplementary groups with
16062 non-valid GIDs, those groups are not set.
16063 Defaults to @samp{1}.
16066 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
16068 Defaults to @samp{0}.
16071 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
16072 Maximum allowed length for mail keyword name. It's only forced when
16073 trying to create new keywords.
16074 Defaults to @samp{50}.
16077 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
16078 List of directories under which chrooting is allowed for mail
16079 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
16080 too). This setting doesn't affect @samp{login-chroot}
16081 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
16082 "/./" in home dirs are ignored. WARNING: Never add directories here
16083 which local users can modify, that may lead to root exploit. Usually
16084 this should be done only if you don't allow shell access for users.
16085 <doc/wiki/Chrooting.txt>.
16086 Defaults to @samp{()}.
16089 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
16090 Default chroot directory for mail processes. This can be overridden
16091 for specific users in user database by giving /./ in user's home
16092 directory (e.g.@: /home/./user chroots into /home). Note that usually
16093 there is no real need to do chrooting, Dovecot doesn't allow users to
16094 access files outside their mail directory anyway. If your home
16095 directories are prefixed with the chroot directory, append "/."@: to
16096 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
16097 Defaults to @samp{""}.
16100 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
16101 UNIX socket path to master authentication server to find users.
16102 This is used by imap (for shared users) and lda.
16103 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16106 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
16107 Directory where to look up mail plugins.
16108 Defaults to @samp{"/usr/lib/dovecot"}.
16111 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
16112 List of plugins to load for all services. Plugins specific to IMAP,
16113 LDA, etc.@: are added to this list in their own .conf files.
16114 Defaults to @samp{()}.
16117 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
16118 The minimum number of mails in a mailbox before updates are done to
16119 cache file. This allows optimizing Dovecot's behavior to do less disk
16120 writes at the cost of more disk reads.
16121 Defaults to @samp{0}.
16124 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
16125 When IDLE command is running, mailbox is checked once in a while to
16126 see if there are any new mails or other changes. This setting defines
16127 the minimum time to wait between those checks. Dovecot can also use
16128 dnotify, inotify and kqueue to find out immediately when changes
16130 Defaults to @samp{"30 secs"}.
16133 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
16134 Save mails with CR+LF instead of plain LF. This makes sending those
16135 mails take less CPU, especially with sendfile() syscall with Linux and
16136 FreeBSD. But it also creates a bit more disk I/O which may just make it
16137 slower. Also note that if other software reads the mboxes/maildirs,
16138 they may handle the extra CRs wrong and cause problems.
16139 Defaults to @samp{#f}.
16142 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
16143 By default LIST command returns all entries in maildir beginning
16144 with a dot. Enabling this option makes Dovecot return only entries
16145 which are directories. This is done by stat()ing each entry, so it
16146 causes more disk I/O.
16147 (For systems setting struct @samp{dirent->d_type} this check is free
16148 and it's done always regardless of this setting).
16149 Defaults to @samp{#f}.
16152 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
16153 When copying a message, do it with hard links whenever possible.
16154 This makes the performance much better, and it's unlikely to have any
16156 Defaults to @samp{#t}.
16159 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
16160 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
16161 directory only when its mtime changes unexpectedly or when we can't find
16162 the mail otherwise.
16163 Defaults to @samp{#f}.
16166 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
16167 Which locking methods to use for locking mbox. There are four
16172 Create <mailbox>.lock file. This is the oldest and most NFS-safe
16173 solution. If you want to use /var/mail/ like directory, the users will
16174 need write access to that directory.
16176 Same as dotlock, but if it fails because of permissions or because there
16177 isn't enough disk space, just skip it.
16179 Use this if possible. Works with NFS too if lockd is used.
16181 May not exist in all systems. Doesn't work with NFS.
16183 May not exist in all systems. Doesn't work with NFS.
16186 You can use multiple locking methods; if you do the order they're declared
16187 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
16188 locking methods as well. Some operating systems don't allow using some of
16189 them simultaneously.
16192 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
16196 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
16197 Maximum time to wait for lock (all of them) before aborting.
16198 Defaults to @samp{"5 mins"}.
16201 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
16202 If dotlock exists but the mailbox isn't modified in any way,
16203 override the lock file after this much time.
16204 Defaults to @samp{"2 mins"}.
16207 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
16208 When mbox changes unexpectedly we have to fully read it to find out
16209 what changed. If the mbox is large this can take a long time. Since
16210 the change is usually just a newly appended mail, it'd be faster to
16211 simply read the new mails. If this setting is enabled, Dovecot does
16212 this but still safely fallbacks to re-reading the whole mbox file
16213 whenever something in mbox isn't how it's expected to be. The only real
16214 downside to this setting is that if some other MUA changes message
16215 flags, Dovecot doesn't notice it immediately. Note that a full sync is
16216 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
16217 Defaults to @samp{#t}.
16220 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
16221 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
16222 EXAMINE, EXPUNGE or CHECK commands. If this is set,
16223 @samp{mbox-dirty-syncs} is ignored.
16224 Defaults to @samp{#f}.
16227 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
16228 Delay writing mbox headers until doing a full write sync (EXPUNGE
16229 and CHECK commands and when closing the mailbox). This is especially
16230 useful for POP3 where clients often delete all mails. The downside is
16231 that our changes aren't immediately visible to other MUAs.
16232 Defaults to @samp{#t}.
16235 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
16236 If mbox size is smaller than this (e.g.@: 100k), don't write index
16237 files. If an index file already exists it's still read, just not
16239 Defaults to @samp{0}.
16242 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
16243 Maximum dbox file size until it's rotated.
16244 Defaults to @samp{10000000}.
16247 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
16248 Maximum dbox file age until it's rotated. Typically in days. Day
16249 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
16251 Defaults to @samp{"1d"}.
16254 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
16255 When creating new mdbox files, immediately preallocate their size to
16256 @samp{mdbox-rotate-size}. This setting currently works only in Linux
16257 with some file systems (ext4, xfs).
16258 Defaults to @samp{#f}.
16261 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
16262 sdbox and mdbox support saving mail attachments to external files,
16263 which also allows single instance storage for them. Other backends
16264 don't support this for now.
16266 WARNING: This feature hasn't been tested much yet. Use at your own risk.
16268 Directory root where to store mail attachments. Disabled, if empty.
16269 Defaults to @samp{""}.
16272 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
16273 Attachments smaller than this aren't saved externally. It's also
16274 possible to write a plugin to disable saving specific attachments
16276 Defaults to @samp{128000}.
16279 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
16280 File system backend to use for saving attachments:
16283 No SiS done by Dovecot (but this might help FS's own deduplication)
16285 SiS with immediate byte-by-byte comparison during saving
16286 @item sis-queue posix
16287 SiS with delayed comparison and deduplication.
16289 Defaults to @samp{"sis posix"}.
16292 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
16293 Hash format to use in attachment filenames. You can add any text and
16294 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
16295 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
16296 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
16297 Defaults to @samp{"%@{sha1@}"}.
16300 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
16302 Defaults to @samp{100}.
16305 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
16307 Defaults to @samp{1000}.
16310 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
16311 Default VSZ (virtual memory size) limit for service processes.
16312 This is mainly intended to catch and kill processes that leak memory
16313 before they eat up everything.
16314 Defaults to @samp{256000000}.
16317 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
16318 Login user is internally used by login processes. This is the most
16319 untrusted user in Dovecot system. It shouldn't have access to anything
16321 Defaults to @samp{"dovenull"}.
16324 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
16325 Internal user is used by unprivileged processes. It should be
16326 separate from login user, so that login processes can't disturb other
16328 Defaults to @samp{"dovecot"}.
16331 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
16332 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
16333 Defaults to @samp{"required"}.
16336 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
16337 PEM encoded X.509 SSL/TLS certificate (public key).
16338 Defaults to @samp{"</etc/dovecot/default.pem"}.
16341 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
16342 PEM encoded SSL/TLS private key. The key is opened before
16343 dropping root privileges, so keep the key file unreadable by anyone but
16345 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
16348 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
16349 If key file is password protected, give the password here.
16350 Alternatively give it when starting dovecot with -p parameter. Since
16351 this file is often world-readable, you may want to place this setting
16352 instead to a different.
16353 Defaults to @samp{""}.
16356 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
16357 PEM encoded trusted certificate authority. Set this only if you
16358 intend to use @samp{ssl-verify-client-cert? #t}. The file should
16359 contain the CA certificate(s) followed by the matching
16360 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
16361 Defaults to @samp{""}.
16364 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
16365 Require that CRL check succeeds for client certificates.
16366 Defaults to @samp{#t}.
16369 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
16370 Request client to send a certificate. If you also want to require
16371 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
16372 Defaults to @samp{#f}.
16375 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
16376 Which field from certificate to use for username. commonName and
16377 x500UniqueIdentifier are the usual choices. You'll also need to set
16378 @samp{auth-ssl-username-from-cert? #t}.
16379 Defaults to @samp{"commonName"}.
16382 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
16383 Minimum SSL protocol version to accept.
16384 Defaults to @samp{"TLSv1"}.
16387 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
16388 SSL ciphers to use.
16389 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
16392 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
16393 SSL crypto device to use, for valid values run "openssl engine".
16394 Defaults to @samp{""}.
16397 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
16398 Address to use when sending rejection mails.
16399 %d expands to recipient domain.
16400 Defaults to @samp{"postmaster@@%d"}.
16403 @deftypevr {@code{dovecot-configuration} parameter} string hostname
16404 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
16405 and in LMTP replies. Default is the system's real hostname@@domain.
16406 Defaults to @samp{""}.
16409 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
16410 If user is over quota, return with temporary failure instead of
16412 Defaults to @samp{#f}.
16415 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
16416 Binary to use for sending mails.
16417 Defaults to @samp{"/usr/sbin/sendmail"}.
16420 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
16421 If non-empty, send mails via this SMTP host[:port] instead of
16423 Defaults to @samp{""}.
16426 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
16427 Subject: header to use for rejection mails. You can use the same
16428 variables as for @samp{rejection-reason} below.
16429 Defaults to @samp{"Rejected: %s"}.
16432 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
16433 Human readable error message for rejection mails. You can use
16446 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
16449 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
16450 Delimiter character between local-part and detail in email
16452 Defaults to @samp{"+"}.
16455 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
16456 Header where the original recipient address (SMTP's RCPT TO:
16457 address) is taken from if not available elsewhere. With dovecot-lda -a
16458 parameter overrides this. A commonly used header for this is
16460 Defaults to @samp{""}.
16463 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
16464 Should saving a mail to a nonexistent mailbox automatically create
16466 Defaults to @samp{#f}.
16469 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
16470 Should automatically created mailboxes be also automatically
16472 Defaults to @samp{#f}.
16475 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
16476 Maximum IMAP command line length. Some clients generate very long
16477 command lines with huge mailboxes, so you may need to raise this if you
16478 get "Too long argument" or "IMAP command line too large" errors
16480 Defaults to @samp{64000}.
16483 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
16484 IMAP logout format string:
16487 total number of bytes read from client
16489 total number of bytes sent to client.
16491 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
16492 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@}"}.
16495 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
16496 Override the IMAP CAPABILITY response. If the value begins with '+',
16497 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
16498 Defaults to @samp{""}.
16501 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
16502 How long to wait between "OK Still here" notifications when client
16504 Defaults to @samp{"2 mins"}.
16507 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
16508 ID field names and values to send to clients. Using * as the value
16509 makes Dovecot use the default value. The following fields have default
16510 values currently: name, version, os, os-version, support-url,
16512 Defaults to @samp{""}.
16515 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
16516 ID fields sent by client to log. * means everything.
16517 Defaults to @samp{""}.
16520 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
16521 Workarounds for various client bugs:
16524 @item delay-newmail
16525 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
16526 CHECK commands. Some clients ignore them otherwise, for example OSX
16527 Mail (<v2.1). Outlook Express breaks more badly though, without this it
16528 may show user "Message no longer in server" errors. Note that OE6
16529 still breaks even with this workaround if synchronization is set to
16532 @item tb-extra-mailbox-sep
16533 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
16534 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
16535 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
16537 @item tb-lsub-flags
16538 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
16539 This makes Thunderbird realize they aren't selectable and show them
16540 greyed out, instead of only later giving "not selectable" popup error.
16542 Defaults to @samp{()}.
16545 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
16546 Host allowed in URLAUTH URLs sent by client. "*" allows all.
16547 Defaults to @samp{""}.
16551 Whew! Lots of configuration options. The nice thing about it though is
16552 that Guix has a complete interface to Dovecot's configuration
16553 language. This allows not only a nice way to declare configurations,
16554 but also offers reflective capabilities as well: users can write code to
16555 inspect and transform configurations from within Scheme.
16557 However, it could be that you just want to get a @code{dovecot.conf} up
16558 and running. In that case, you can pass an
16559 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
16560 @code{dovecot-service}. As its name indicates, an opaque configuration
16561 does not have easy reflective capabilities.
16563 Available @code{opaque-dovecot-configuration} fields are:
16565 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
16566 The dovecot package.
16569 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
16570 The contents of the @code{dovecot.conf}, as a string.
16573 For example, if your @code{dovecot.conf} is just the empty string, you
16574 could instantiate a dovecot service like this:
16577 (dovecot-service #:config
16578 (opaque-dovecot-configuration
16582 @subsubheading OpenSMTPD Service
16584 @deffn {Scheme Variable} opensmtpd-service-type
16585 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
16586 service, whose value should be an @code{opensmtpd-configuration} object
16587 as in this example:
16590 (service opensmtpd-service-type
16591 (opensmtpd-configuration
16592 (config-file (local-file "./my-smtpd.conf"))))
16596 @deftp {Data Type} opensmtpd-configuration
16597 Data type representing the configuration of opensmtpd.
16600 @item @code{package} (default: @var{opensmtpd})
16601 Package object of the OpenSMTPD SMTP server.
16603 @item @code{config-file} (default: @var{%default-opensmtpd-file})
16604 File-like object of the OpenSMTPD configuration file to use. By default
16605 it listens on the loopback network interface, and allows for mail from
16606 users and daemons on the local machine, as well as permitting email to
16607 remote servers. Run @command{man smtpd.conf} for more information.
16612 @subsubheading Exim Service
16614 @cindex mail transfer agent (MTA)
16615 @cindex MTA (mail transfer agent)
16618 @deffn {Scheme Variable} exim-service-type
16619 This is the type of the @uref{https://exim.org, Exim} mail transfer
16620 agent (MTA), whose value should be an @code{exim-configuration} object
16621 as in this example:
16624 (service exim-service-type
16625 (exim-configuration
16626 (config-file (local-file "./my-exim.conf"))))
16630 In order to use an @code{exim-service-type} service you must also have a
16631 @code{mail-aliases-service-type} service present in your
16632 @code{operating-system} (even if it has no aliases).
16634 @deftp {Data Type} exim-configuration
16635 Data type representing the configuration of exim.
16638 @item @code{package} (default: @var{exim})
16639 Package object of the Exim server.
16641 @item @code{config-file} (default: @code{#f})
16642 File-like object of the Exim configuration file to use. If its value is
16643 @code{#f} then use the default configuration file from the package
16644 provided in @code{package}. The resulting configuration file is loaded
16645 after setting the @code{exim_user} and @code{exim_group} configuration
16651 @subsubheading Mail Aliases Service
16653 @cindex email aliases
16654 @cindex aliases, for email addresses
16656 @deffn {Scheme Variable} mail-aliases-service-type
16657 This is the type of the service which provides @code{/etc/aliases},
16658 specifying how to deliver mail to users on this system.
16661 (service mail-aliases-service-type
16662 '(("postmaster" "bob")
16663 ("bob" "bob@@example.com" "bob@@example2.com")))
16667 The configuration for a @code{mail-aliases-service-type} service is an
16668 association list denoting how to deliver mail that comes to this
16669 system. Each entry is of the form @code{(alias addresses ...)}, with
16670 @code{alias} specifying the local alias and @code{addresses} specifying
16671 where to deliver this user's mail.
16673 The aliases aren't required to exist as users on the local system. In
16674 the above example, there doesn't need to be a @code{postmaster} entry in
16675 the @code{operating-system}'s @code{user-accounts} in order to deliver
16676 the @code{postmaster} mail to @code{bob} (which subsequently would
16677 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
16679 @subsubheading GNU Mailutils IMAP4 Daemon
16680 @cindex GNU Mailutils IMAP4 Daemon
16682 @deffn {Scheme Variable} imap4d-service-type
16683 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
16684 mailutils, GNU Mailutils Manual}), whose value should be an
16685 @code{imap4d-configuration} object as in this example:
16688 (service imap4d-service-type
16689 (imap4d-configuration
16690 (config-file (local-file "imap4d.conf"))))
16694 @deftp {Data Type} imap4d-configuration
16695 Data type representing the configuration of @command{imap4d}.
16698 @item @code{package} (default: @code{mailutils})
16699 The package that provides @command{imap4d}.
16701 @item @code{config-file} (default: @code{%default-imap4d-config-file})
16702 File-like object of the configuration file to use, by default it will listen
16703 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
16704 Mailutils Manual}, for details.
16709 @node Messaging Services
16710 @subsection Messaging Services
16715 The @code{(gnu services messaging)} module provides Guix service
16716 definitions for messaging services: currently only Prosody is supported.
16718 @subsubheading Prosody Service
16720 @deffn {Scheme Variable} prosody-service-type
16721 This is the type for the @uref{https://prosody.im, Prosody XMPP
16722 communication server}. Its value must be a @code{prosody-configuration}
16723 record as in this example:
16726 (service prosody-service-type
16727 (prosody-configuration
16728 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
16731 (int-component-configuration
16732 (hostname "conference.example.net")
16734 (mod-muc (mod-muc-configuration)))))
16737 (virtualhost-configuration
16738 (domain "example.net"))))))
16741 See below for details about @code{prosody-configuration}.
16745 By default, Prosody does not need much configuration. Only one
16746 @code{virtualhosts} field is needed: it specifies the domain you wish
16749 You can perform various sanity checks on the generated configuration
16750 with the @code{prosodyctl check} command.
16752 Prosodyctl will also help you to import certificates from the
16753 @code{letsencrypt} directory so that the @code{prosody} user can access
16754 them. See @url{https://prosody.im/doc/letsencrypt}.
16757 prosodyctl --root cert import /etc/letsencrypt/live
16760 The available configuration parameters follow. Each parameter
16761 definition is preceded by its type; for example, @samp{string-list foo}
16762 indicates that the @code{foo} parameter should be specified as a list of
16763 strings. Types starting with @code{maybe-} denote parameters that won't
16764 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
16766 There is also a way to specify the configuration as a string, if you
16767 have an old @code{prosody.cfg.lua} file that you want to port over from
16768 some other system; see the end for more details.
16770 The @code{file-object} type designates either a file-like object
16771 (@pxref{G-Expressions, file-like objects}) or a file name.
16773 @c The following documentation was initially generated by
16774 @c (generate-documentation) in (gnu services messaging). Manually maintained
16775 @c documentation is better, so we shouldn't hesitate to edit below as
16776 @c needed. However if the change you want to make to this documentation
16777 @c can be done in an automated way, it's probably easier to change
16778 @c (generate-documentation) than to make it below and have to deal with
16779 @c the churn as Prosody updates.
16781 Available @code{prosody-configuration} fields are:
16783 @deftypevr {@code{prosody-configuration} parameter} package prosody
16784 The Prosody package.
16787 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
16788 Location of the Prosody data storage directory. See
16789 @url{https://prosody.im/doc/configure}.
16790 Defaults to @samp{"/var/lib/prosody"}.
16793 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
16794 Additional plugin directories. They are searched in all the specified
16795 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
16796 Defaults to @samp{()}.
16799 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
16800 Every virtual host and component needs a certificate so that clients and
16801 servers can securely verify its identity. Prosody will automatically load
16802 certificates/keys from the directory specified here.
16803 Defaults to @samp{"/etc/prosody/certs"}.
16806 @deftypevr {@code{prosody-configuration} parameter} string-list admins
16807 This is a list of accounts that are admins for the server. Note that you
16808 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
16809 @url{https://prosody.im/doc/creating_accounts}.
16810 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
16811 Defaults to @samp{()}.
16814 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
16815 Enable use of libevent for better performance under high load. See
16816 @url{https://prosody.im/doc/libevent}.
16817 Defaults to @samp{#f}.
16820 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
16821 This is the list of modules Prosody will load on startup. It looks for
16822 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
16823 Documentation on modules can be found at:
16824 @url{https://prosody.im/doc/modules}.
16825 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
16828 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
16829 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
16830 should you want to disable them then add them to this list.
16831 Defaults to @samp{()}.
16834 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
16835 Path to a text file where the shared groups are defined. If this path is
16836 empty then @samp{mod_groups} does nothing. See
16837 @url{https://prosody.im/doc/modules/mod_groups}.
16838 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
16841 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
16842 Disable account creation by default, for security. See
16843 @url{https://prosody.im/doc/creating_accounts}.
16844 Defaults to @samp{#f}.
16847 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
16848 These are the SSL/TLS-related settings. Most of them are disabled so to
16849 use Prosody's defaults. If you do not completely understand these options, do
16850 not add them to your config, it is easy to lower the security of your server
16851 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
16853 Available @code{ssl-configuration} fields are:
16855 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
16856 This determines what handshake to use.
16859 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
16860 Path to your private key file.
16863 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
16864 Path to your certificate file.
16867 @deftypevr {@code{ssl-configuration} parameter} file-object capath
16868 Path to directory containing root certificates that you wish Prosody to
16869 trust when verifying the certificates of remote servers.
16870 Defaults to @samp{"/etc/ssl/certs"}.
16873 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
16874 Path to a file containing root certificates that you wish Prosody to trust.
16875 Similar to @code{capath} but with all certificates concatenated together.
16878 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
16879 A list of verification options (these mostly map to OpenSSL's
16880 @code{set_verify()} flags).
16883 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
16884 A list of general options relating to SSL/TLS. These map to OpenSSL's
16885 @code{set_options()}. For a full list of options available in LuaSec, see the
16889 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
16890 How long a chain of certificate authorities to check when looking for a
16891 trusted root certificate.
16894 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
16895 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
16896 clients, and in what order.
16899 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
16900 A path to a file containing parameters for Diffie-Hellman key exchange. You
16901 can create such a file with:
16902 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
16905 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
16906 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
16907 @samp{"secp384r1"}.
16910 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
16911 A list of "extra" verification options.
16914 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
16915 Password for encrypted private keys.
16920 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
16921 Whether to force all client-to-server connections to be encrypted or not.
16922 See @url{https://prosody.im/doc/modules/mod_tls}.
16923 Defaults to @samp{#f}.
16926 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
16927 Set of mechanisms that will never be offered. See
16928 @url{https://prosody.im/doc/modules/mod_saslauth}.
16929 Defaults to @samp{("DIGEST-MD5")}.
16932 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
16933 Whether to force all server-to-server connections to be encrypted or not.
16934 See @url{https://prosody.im/doc/modules/mod_tls}.
16935 Defaults to @samp{#f}.
16938 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
16939 Whether to require encryption and certificate authentication. This
16940 provides ideal security, but requires servers you communicate with to support
16941 encryption AND present valid, trusted certificates. See
16942 @url{https://prosody.im/doc/s2s#security}.
16943 Defaults to @samp{#f}.
16946 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
16947 Many servers don't support encryption or have invalid or self-signed
16948 certificates. You can list domains here that will not be required to
16949 authenticate using certificates. They will be authenticated using DNS. See
16950 @url{https://prosody.im/doc/s2s#security}.
16951 Defaults to @samp{()}.
16954 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
16955 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
16956 valid certificates for some domains by specifying a list here. See
16957 @url{https://prosody.im/doc/s2s#security}.
16958 Defaults to @samp{()}.
16961 @deftypevr {@code{prosody-configuration} parameter} string authentication
16962 Select the authentication backend to use. The default provider stores
16963 passwords in plaintext and uses Prosody's configured data storage to store the
16964 authentication data. If you do not trust your server please see
16965 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
16966 about using the hashed backend. See also
16967 @url{https://prosody.im/doc/authentication}
16968 Defaults to @samp{"internal_plain"}.
16971 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
16972 Set logging options. Advanced logging configuration is not yet supported
16973 by the Prosody service. See @url{https://prosody.im/doc/logging}.
16974 Defaults to @samp{"*syslog"}.
16977 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
16978 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
16979 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
16982 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
16983 Maximum allowed size of the HTTP body (in bytes).
16986 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
16987 Some modules expose their own URL in various ways. This URL is built
16988 from the protocol, host and port used. If Prosody sits behind a proxy, the
16989 public URL will be @code{http-external-url} instead. See
16990 @url{https://prosody.im/doc/http#external_url}.
16993 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
16994 A host in Prosody is a domain on which user accounts can be created. For
16995 example if you want your users to have addresses like
16996 @samp{"john.smith@@example.com"} then you need to add a host
16997 @samp{"example.com"}. All options in this list will apply only to this host.
16999 Note: the name "virtual" host is used in configuration to avoid confusion with
17000 the actual physical host that Prosody is installed on. A single Prosody
17001 instance can serve many domains, each one defined as a VirtualHost entry in
17002 Prosody's configuration. Conversely a server that hosts a single domain would
17003 have just one VirtualHost entry.
17005 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
17007 Available @code{virtualhost-configuration} fields are:
17009 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:
17010 @deftypevr {@code{virtualhost-configuration} parameter} string domain
17011 Domain you wish Prosody to serve.
17016 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
17017 Components are extra services on a server which are available to clients,
17018 usually on a subdomain of the main server (such as
17019 @samp{"mycomponent.example.com"}). Example components might be chatroom
17020 servers, user directories, or gateways to other protocols.
17022 Internal components are implemented with Prosody-specific plugins. To add an
17023 internal component, you simply fill the hostname field, and the plugin you wish
17024 to use for the component.
17026 See @url{https://prosody.im/doc/components}.
17027 Defaults to @samp{()}.
17029 Available @code{int-component-configuration} fields are:
17031 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:
17032 @deftypevr {@code{int-component-configuration} parameter} string hostname
17033 Hostname of the component.
17036 @deftypevr {@code{int-component-configuration} parameter} string plugin
17037 Plugin you wish to use for the component.
17040 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
17041 Multi-user chat (MUC) is Prosody's module for allowing you to create
17042 hosted chatrooms/conferences for XMPP users.
17044 General information on setting up and using multi-user chatrooms can be found
17045 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
17046 which you should read if you are new to XMPP chatrooms.
17048 See also @url{https://prosody.im/doc/modules/mod_muc}.
17050 Available @code{mod-muc-configuration} fields are:
17052 @deftypevr {@code{mod-muc-configuration} parameter} string name
17053 The name to return in service discovery responses.
17054 Defaults to @samp{"Prosody Chatrooms"}.
17057 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
17058 If @samp{#t}, this will only allow admins to create new chatrooms.
17059 Otherwise anyone can create a room. The value @samp{"local"} restricts room
17060 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
17061 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
17062 restricts to service administrators only.
17063 Defaults to @samp{#f}.
17066 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
17067 Maximum number of history messages that will be sent to the member that has
17068 just joined the room.
17069 Defaults to @samp{20}.
17076 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
17077 External components use XEP-0114, which most standalone components
17078 support. To add an external component, you simply fill the hostname field. See
17079 @url{https://prosody.im/doc/components}.
17080 Defaults to @samp{()}.
17082 Available @code{ext-component-configuration} fields are:
17084 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:
17085 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
17086 Password which the component will use to log in.
17089 @deftypevr {@code{ext-component-configuration} parameter} string hostname
17090 Hostname of the component.
17095 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
17096 Port(s) Prosody listens on for component connections.
17097 Defaults to @samp{(5347)}.
17100 @deftypevr {@code{prosody-configuration} parameter} string component-interface
17101 Interface Prosody listens on for component connections.
17102 Defaults to @samp{"127.0.0.1"}.
17105 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
17106 Raw content that will be added to the configuration file.
17109 It could be that you just want to get a @code{prosody.cfg.lua}
17110 up and running. In that case, you can pass an
17111 @code{opaque-prosody-configuration} record as the value of
17112 @code{prosody-service-type}. As its name indicates, an opaque configuration
17113 does not have easy reflective capabilities.
17114 Available @code{opaque-prosody-configuration} fields are:
17116 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
17117 The prosody package.
17120 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
17121 The contents of the @code{prosody.cfg.lua} to use.
17124 For example, if your @code{prosody.cfg.lua} is just the empty
17125 string, you could instantiate a prosody service like this:
17128 (service prosody-service-type
17129 (opaque-prosody-configuration
17130 (prosody.cfg.lua "")))
17133 @c end of Prosody auto-generated documentation
17135 @subsubheading BitlBee Service
17137 @cindex IRC (Internet Relay Chat)
17138 @cindex IRC gateway
17139 @url{http://bitlbee.org,BitlBee} is a gateway that provides an IRC
17140 interface to a variety of messaging protocols such as XMPP.
17142 @defvr {Scheme Variable} bitlbee-service-type
17143 This is the service type for the @url{http://bitlbee.org,BitlBee} IRC
17144 gateway daemon. Its value is a @code{bitlbee-configuration} (see
17147 To have BitlBee listen on port 6667 on localhost, add this line to your
17151 (service bitlbee-service-type)
17155 @deftp {Data Type} bitlbee-configuration
17156 This is the configuration for BitlBee, with the following fields:
17159 @item @code{interface} (default: @code{"127.0.0.1"})
17160 @itemx @code{port} (default: @code{6667})
17161 Listen on the network interface corresponding to the IP address
17162 specified in @var{interface}, on @var{port}.
17164 When @var{interface} is @code{127.0.0.1}, only local clients can
17165 connect; when it is @code{0.0.0.0}, connections can come from any
17166 networking interface.
17168 @item @code{package} (default: @code{bitlbee})
17169 The BitlBee package to use.
17171 @item @code{plugins} (default: @code{'()})
17172 List of plugin packages to use---e.g., @code{bitlbee-discord}.
17174 @item @code{extra-settings} (default: @code{""})
17175 Configuration snippet added as-is to the BitlBee configuration file.
17179 @subsubheading Quassel Service
17181 @cindex IRC (Internet Relay Chat)
17182 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
17183 meaning that one or more clients can attach to and detach from the
17186 @defvr {Scheme Variable} quassel-service-type
17187 This is the service type for the @url{https://quassel-irc.org/,Quassel}
17188 IRC backend daemon. Its value is a @code{quassel-configuration}
17192 @deftp {Data Type} quassel-configuration
17193 This is the configuration for Quassel, with the following fields:
17196 @item @code{quassel} (default: @code{quassel})
17197 The Quassel package to use.
17199 @item @code{interface} (default: @code{"::,0.0.0.0"})
17200 @item @code{port} (default: @code{4242})
17201 Listen on the network interface(s) corresponding to the IPv4 or IPv6
17202 interfaces specified in the comma delimited @var{interface}, on
17205 @item @code{loglevel} (default: @code{"Info"})
17206 The level of logging desired. Accepted values are Debug, Info, Warning
17211 @node Telephony Services
17212 @subsection Telephony Services
17214 @cindex Murmur (VoIP server)
17215 @cindex VoIP server
17216 This section describes how to set up and run a Murmur server. Murmur is
17217 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
17220 @deftp {Data Type} murmur-configuration
17221 The service type for the Murmur server. An example configuration can
17225 (service murmur-service-type
17226 (murmur-configuration
17228 "Welcome to this Mumble server running on Guix!")
17229 (cert-required? #t) ;disallow text password logins
17230 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
17231 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
17234 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
17235 password with the command that is printed during the activation phase.
17237 It is recommended to register a normal Mumble user account
17238 and grant it admin or moderator rights.
17239 You can use the @code{mumble} client to
17240 login as new normal user, register yourself, and log out.
17241 For the next step login with the name @code{SuperUser} use
17242 the @code{SuperUser} password that you set previously,
17243 and grant your newly registered mumble user administrator or moderator
17244 rights and create some channels.
17246 Available @code{murmur-configuration} fields are:
17249 @item @code{package} (default: @code{mumble})
17250 Package that contains @code{bin/murmurd}.
17252 @item @code{user} (default: @code{"murmur"})
17253 User who will run the Murmur server.
17255 @item @code{group} (default: @code{"murmur"})
17256 Group of the user who will run the murmur server.
17258 @item @code{port} (default: @code{64738})
17259 Port on which the server will listen.
17261 @item @code{welcome-text} (default: @code{""})
17262 Welcome text sent to clients when they connect.
17264 @item @code{server-password} (default: @code{""})
17265 Password the clients have to enter in order to connect.
17267 @item @code{max-users} (default: @code{100})
17268 Maximum of users that can be connected to the server at once.
17270 @item @code{max-user-bandwidth} (default: @code{#f})
17271 Maximum voice traffic a user can send per second.
17273 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
17274 File name of the sqlite database.
17275 The service's user will become the owner of the directory.
17277 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
17278 File name of the log file.
17279 The service's user will become the owner of the directory.
17281 @item @code{autoban-attempts} (default: @code{10})
17282 Maximum number of logins a user can make in @code{autoban-timeframe}
17283 without getting auto banned for @code{autoban-time}.
17285 @item @code{autoban-timeframe} (default: @code{120})
17286 Timeframe for autoban in seconds.
17288 @item @code{autoban-time} (default: @code{300})
17289 Amount of time in seconds for which a client gets banned
17290 when violating the autoban limits.
17292 @item @code{opus-threshold} (default: @code{100})
17293 Percentage of clients that need to support opus
17294 before switching over to opus audio codec.
17296 @item @code{channel-nesting-limit} (default: @code{10})
17297 How deep channels can be nested at maximum.
17299 @item @code{channelname-regex} (default: @code{#f})
17300 A string in form of a Qt regular expression that channel names must conform to.
17302 @item @code{username-regex} (default: @code{#f})
17303 A string in form of a Qt regular expression that user names must conform to.
17305 @item @code{text-message-length} (default: @code{5000})
17306 Maximum size in bytes that a user can send in one text chat message.
17308 @item @code{image-message-length} (default: @code{(* 128 1024)})
17309 Maximum size in bytes that a user can send in one image message.
17311 @item @code{cert-required?} (default: @code{#f})
17312 If it is set to @code{#t} clients that use weak password authentification
17313 will not be accepted. Users must have completed the certificate wizard to join.
17315 @item @code{remember-channel?} (default: @code{#f})
17316 Should murmur remember the last channel each user was in when they disconnected
17317 and put them into the remembered channel when they rejoin.
17319 @item @code{allow-html?} (default: @code{#f})
17320 Should html be allowed in text messages, user comments, and channel descriptions.
17322 @item @code{allow-ping?} (default: @code{#f})
17323 Setting to true exposes the current user count, the maximum user count, and
17324 the server's maximum bandwidth per client to unauthenticated users. In the
17325 Mumble client, this information is shown in the Connect dialog.
17327 Disabling this setting will prevent public listing of the server.
17329 @item @code{bonjour?} (default: @code{#f})
17330 Should the server advertise itself in the local network through the bonjour protocol.
17332 @item @code{send-version?} (default: @code{#f})
17333 Should the murmur server version be exposed in ping requests.
17335 @item @code{log-days} (default: @code{31})
17336 Murmur also stores logs in the database, which are accessible via RPC.
17337 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
17338 or -1 to disable logging to the database.
17340 @item @code{obfuscate-ips?} (default: @code{#t})
17341 Should logged ips be obfuscated to protect the privacy of users.
17343 @item @code{ssl-cert} (default: @code{#f})
17344 File name of the SSL/TLS certificate used for encrypted connections.
17347 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
17349 @item @code{ssl-key} (default: @code{#f})
17350 Filepath to the ssl private key used for encrypted connections.
17352 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
17355 @item @code{ssl-dh-params} (default: @code{#f})
17356 File name of a PEM-encoded file with Diffie-Hellman parameters
17357 for the SSL/TLS encryption. Alternatively you set it to
17358 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
17359 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
17361 @item @code{ssl-ciphers} (default: @code{#f})
17362 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
17365 This option is specified using
17366 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
17367 OpenSSL cipher list notation}.
17369 It is recommended that you try your cipher string using 'openssl ciphers <string>'
17370 before setting it here, to get a feel for which cipher suites you will get.
17371 After setting this option, it is recommend that you inspect your Murmur log
17372 to ensure that Murmur is using the cipher suites that you expected it to.
17374 Note: Changing this option may impact the backwards compatibility of your
17375 Murmur server, and can remove the ability for older Mumble clients to be able
17378 @item @code{public-registration} (default: @code{#f})
17379 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
17381 You can optionally register your server in the public server list that the
17382 @code{mumble} client shows on startup.
17383 You cannot register your server if you have set a @code{server-password},
17384 or set @code{allow-ping} to @code{#f}.
17386 It might take a few hours until it shows up in the public list.
17388 @item @code{file} (default: @code{#f})
17389 Optional alternative override for this configuration.
17393 @deftp {Data Type} murmur-public-registration-configuration
17394 Configuration for public registration of a murmur service.
17398 This is a display name for your server. Not to be confused with the hostname.
17400 @item @code{password}
17401 A password to identify your registration.
17402 Subsequent updates will need the same password. Don't lose your password.
17405 This should be a @code{http://} or @code{https://} link to your web
17408 @item @code{hostname} (default: @code{#f})
17409 By default your server will be listed by its IP address.
17410 If it is set your server will be linked by this host name instead.
17416 @node Monitoring Services
17417 @subsection Monitoring Services
17419 @subsubheading Tailon Service
17421 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
17422 viewing and searching log files.
17424 The following example will configure the service with default values.
17425 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
17428 (service tailon-service-type)
17431 The following example customises more of the Tailon configuration,
17432 adding @command{sed} to the list of allowed commands.
17435 (service tailon-service-type
17436 (tailon-configuration
17438 (tailon-configuration-file
17439 (allowed-commands '("tail" "grep" "awk" "sed"))))))
17443 @deftp {Data Type} tailon-configuration
17444 Data type representing the configuration of Tailon.
17445 This type has the following parameters:
17448 @item @code{config-file} (default: @code{(tailon-configuration-file)})
17449 The configuration file to use for Tailon. This can be set to a
17450 @dfn{tailon-configuration-file} record value, or any gexp
17451 (@pxref{G-Expressions}).
17453 For example, to instead use a local file, the @code{local-file} function
17457 (service tailon-service-type
17458 (tailon-configuration
17459 (config-file (local-file "./my-tailon.conf"))))
17462 @item @code{package} (default: @code{tailon})
17463 The tailon package to use.
17468 @deftp {Data Type} tailon-configuration-file
17469 Data type representing the configuration options for Tailon.
17470 This type has the following parameters:
17473 @item @code{files} (default: @code{(list "/var/log")})
17474 List of files to display. The list can include strings for a single file
17475 or directory, or a list, where the first item is the name of a
17476 subsection, and the remaining items are the files or directories in that
17479 @item @code{bind} (default: @code{"localhost:8080"})
17480 Address and port to which Tailon should bind on.
17482 @item @code{relative-root} (default: @code{#f})
17483 URL path to use for Tailon, set to @code{#f} to not use a path.
17485 @item @code{allow-transfers?} (default: @code{#t})
17486 Allow downloading the log files in the web interface.
17488 @item @code{follow-names?} (default: @code{#t})
17489 Allow tailing of not-yet existent files.
17491 @item @code{tail-lines} (default: @code{200})
17492 Number of lines to read initially from each file.
17494 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
17495 Commands to allow running. By default, @code{sed} is disabled.
17497 @item @code{debug?} (default: @code{#f})
17498 Set @code{debug?} to @code{#t} to show debug messages.
17500 @item @code{wrap-lines} (default: @code{#t})
17501 Initial line wrapping state in the web interface. Set to @code{#t} to
17502 initially wrap lines (the default), or to @code{#f} to initially not
17505 @item @code{http-auth} (default: @code{#f})
17506 HTTP authentication type to use. Set to @code{#f} to disable
17507 authentication (the default). Supported values are @code{"digest"} or
17510 @item @code{users} (default: @code{#f})
17511 If HTTP authentication is enabled (see @code{http-auth}), access will be
17512 restricted to the credentials provided here. To configure users, use a
17513 list of pairs, where the first element of the pair is the username, and
17514 the 2nd element of the pair is the password.
17517 (tailon-configuration-file
17518 (http-auth "basic")
17519 (users '(("user1" . "password1")
17520 ("user2" . "password2"))))
17527 @subsubheading Darkstat Service
17529 Darkstat is a packet sniffer that captures network traffic, calculates
17530 statistics about usage, and serves reports over HTTP.
17532 @defvar {Scheme Variable} darkstat-service-type
17533 This is the service type for the
17534 @uref{https://unix4lyfe.org/darkstat/, darkstat}
17535 service, its value must be a @code{darkstat-configuration} record as in
17539 (service darkstat-service-type
17540 (darkstat-configuration
17541 (interface "eno1")))
17545 @deftp {Data Type} darkstat-configuration
17546 Data type representing the configuration of @command{darkstat}.
17549 @item @code{package} (default: @code{darkstat})
17550 The darkstat package to use.
17552 @item @code{interface}
17553 Capture traffic on the specified network interface.
17555 @item @code{port} (default: @code{"667"})
17556 Bind the web interface to the specified port.
17558 @item @code{bind-address} (default: @code{"127.0.0.1"})
17559 Bind the web interface to the specified address.
17561 @item @code{base} (default: @code{"/"})
17562 Specify the path of the base URL. This can be useful if
17563 @command{darkstat} is accessed via a reverse proxy.
17568 @subsubheading Prometheus Node Exporter Service
17570 @cindex prometheus-node-exporter
17571 The Prometheus ``node exporter'' makes hardware and operating system statistics
17572 provided by the Linux kernel available for the Prometheus monitoring system.
17573 This service should be deployed on all physical nodes and virtual machines,
17574 where monitoring these statistics is desirable.
17576 @defvar {Scheme variable} prometheus-node-exporter-service-type
17577 This is the service type for the
17578 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
17579 service, its value must be a @code{prometheus-node-exporter-configuration}
17580 record as in this example:
17583 (service prometheus-node-exporter-service-type
17584 (prometheus-node-exporter-configuration
17585 (web-listen-address ":9100")))
17589 @deftp {Data Type} prometheus-node-exporter-configuration
17590 Data type representing the configuration of @command{node_exporter}.
17593 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
17594 The prometheus-node-exporter package to use.
17596 @item @code{web-listen-address} (default: @code{":9100"})
17597 Bind the web interface to the specified address.
17602 @subsubheading Zabbix server
17603 @cindex zabbix zabbix-server
17604 Zabbix provides monitoring metrics, among others network utilization, CPU load
17605 and disk space consumption:
17608 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
17609 @item Auto-discovery of servers and network devices and interfaces.
17610 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
17611 @item Distributed monitoring with centralized web administration.
17612 @item Native high performance agents.
17613 @item SLA, and ITIL KPI metrics on reporting.
17614 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
17615 @item Remote command execution through Zabbix proxies.
17618 @c %start of fragment
17620 Available @code{zabbix-server-configuration} fields are:
17622 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
17623 The zabbix-server package.
17627 @deftypevr {@code{zabbix-server-configuration} parameter} string user
17628 User who will run the Zabbix server.
17630 Defaults to @samp{"zabbix"}.
17634 @deftypevr {@code{zabbix-server-configuration} parameter} group group
17635 Group who will run the Zabbix server.
17637 Defaults to @samp{"zabbix"}.
17641 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
17642 Database host name.
17644 Defaults to @samp{"127.0.0.1"}.
17648 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
17651 Defaults to @samp{"zabbix"}.
17655 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
17658 Defaults to @samp{"zabbix"}.
17662 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
17663 Database password. Please, use @code{include-files} with
17664 @code{DBPassword=SECRET} inside a specified file instead.
17666 Defaults to @samp{""}.
17670 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
17673 Defaults to @samp{5432}.
17677 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
17678 Specifies where log messages are written to:
17682 @code{system} - syslog.
17685 @code{file} - file specified with @code{log-file} parameter.
17688 @code{console} - standard output.
17692 Defaults to @samp{""}.
17696 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
17697 Log file name for @code{log-type} @code{file} parameter.
17699 Defaults to @samp{"/var/log/zabbix/server.log"}.
17703 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
17706 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
17710 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
17711 The location of certificate authority (CA) files for SSL server
17712 certificate verification.
17714 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
17718 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
17719 Location of SSL client certificates.
17721 Defaults to @samp{"/etc/ssl/certs"}.
17725 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
17726 Extra options will be appended to Zabbix server configuration file.
17728 Defaults to @samp{""}.
17732 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
17733 You may include individual files or all files in a directory in the
17734 configuration file.
17736 Defaults to @samp{()}.
17740 @c %end of fragment
17742 @subsubheading Zabbix agent
17743 @cindex zabbix zabbix-agent
17745 Zabbix agent gathers information for Zabbix server.
17747 @c %start of fragment
17749 Available @code{zabbix-agent-configuration} fields are:
17751 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
17752 The zabbix-agent package.
17756 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
17757 User who will run the Zabbix agent.
17759 Defaults to @samp{"zabbix"}.
17763 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
17764 Group who will run the Zabbix agent.
17766 Defaults to @samp{"zabbix"}.
17770 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
17771 Unique, case sensitive hostname which is required for active checks and
17772 must match hostname as configured on the server.
17774 Defaults to @samp{"Zabbix server"}.
17778 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
17779 Specifies where log messages are written to:
17783 @code{system} - syslog.
17786 @code{file} - file specified with @code{log-file} parameter.
17789 @code{console} - standard output.
17793 Defaults to @samp{""}.
17797 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
17798 Log file name for @code{log-type} @code{file} parameter.
17800 Defaults to @samp{"/var/log/zabbix/agent.log"}.
17804 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
17807 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
17811 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
17812 List of IP addresses, optionally in CIDR notation, or hostnames of
17813 Zabbix servers and Zabbix proxies. Incoming connections will be
17814 accepted only from the hosts listed here.
17816 Defaults to @samp{("127.0.0.1")}.
17820 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
17821 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
17822 proxies for active checks. If port is not specified, default port is
17823 used. If this parameter is not specified, active checks are disabled.
17825 Defaults to @samp{("127.0.0.1")}.
17829 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
17830 Extra options will be appended to Zabbix server configuration file.
17832 Defaults to @samp{""}.
17836 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
17837 You may include individual files or all files in a directory in the
17838 configuration file.
17840 Defaults to @samp{()}.
17844 @c %end of fragment
17846 @subsubheading Zabbix front-end
17847 @cindex zabbix zabbix-front-end
17849 This service provides a WEB interface to Zabbix server.
17851 @c %start of fragment
17853 Available @code{zabbix-front-end-configuration} fields are:
17855 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
17856 NGINX configuration.
17860 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
17861 Database host name.
17863 Defaults to @samp{"localhost"}.
17867 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
17870 Defaults to @samp{5432}.
17874 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
17877 Defaults to @samp{"zabbix"}.
17881 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
17884 Defaults to @samp{"zabbix"}.
17888 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
17889 Database password. Please, use @code{db-secret-file} instead.
17891 Defaults to @samp{""}.
17895 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
17896 Secret file which will be appended to @file{zabbix.conf.php} file. This
17897 file contains credentials for use by Zabbix front-end. You are expected
17898 to create it manually.
17900 Defaults to @samp{""}.
17904 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
17905 Zabbix server hostname.
17907 Defaults to @samp{"localhost"}.
17911 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
17912 Zabbix server port.
17914 Defaults to @samp{10051}.
17919 @c %end of fragment
17921 @node Kerberos Services
17922 @subsection Kerberos Services
17925 The @code{(gnu services kerberos)} module provides services relating to
17926 the authentication protocol @dfn{Kerberos}.
17928 @subsubheading Krb5 Service
17930 Programs using a Kerberos client library normally
17931 expect a configuration file in @file{/etc/krb5.conf}.
17932 This service generates such a file from a definition provided in the
17933 operating system declaration.
17934 It does not cause any daemon to be started.
17936 No ``keytab'' files are provided by this service---you must explicitly create them.
17937 This service is known to work with the MIT client library, @code{mit-krb5}.
17938 Other implementations have not been tested.
17940 @defvr {Scheme Variable} krb5-service-type
17941 A service type for Kerberos 5 clients.
17945 Here is an example of its use:
17947 (service krb5-service-type
17948 (krb5-configuration
17949 (default-realm "EXAMPLE.COM")
17950 (allow-weak-crypto? #t)
17953 (name "EXAMPLE.COM")
17954 (admin-server "groucho.example.com")
17955 (kdc "karl.example.com"))
17958 (admin-server "kerb-admin.argrx.edu")
17959 (kdc "keys.argrx.edu"))))))
17963 This example provides a Kerberos@tie{}5 client configuration which:
17965 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
17966 of which have distinct administration servers and key distribution centers;
17967 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
17968 specified by clients;
17969 @item Accepts services which only support encryption types known to be weak.
17972 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
17973 Only the most commonly used ones are described here.
17974 For a full list, and more detailed explanation of each, see the MIT
17975 @uref{http://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
17979 @deftp {Data Type} krb5-realm
17980 @cindex realm, kerberos
17983 This field is a string identifying the name of the realm.
17984 A common convention is to use the fully qualified DNS name of your organization,
17985 converted to upper case.
17987 @item @code{admin-server}
17988 This field is a string identifying the host where the administration server is
17992 This field is a string identifying the key distribution center
17997 @deftp {Data Type} krb5-configuration
18000 @item @code{allow-weak-crypto?} (default: @code{#f})
18001 If this flag is @code{#t} then services which only offer encryption algorithms
18002 known to be weak will be accepted.
18004 @item @code{default-realm} (default: @code{#f})
18005 This field should be a string identifying the default Kerberos
18006 realm for the client.
18007 You should set this field to the name of your Kerberos realm.
18008 If this value is @code{#f}
18009 then a realm must be specified with every Kerberos principal when invoking programs
18010 such as @command{kinit}.
18012 @item @code{realms}
18013 This should be a non-empty list of @code{krb5-realm} objects, which clients may
18015 Normally, one of them will have a @code{name} field matching the @code{default-realm}
18021 @subsubheading PAM krb5 Service
18024 The @code{pam-krb5} service allows for login authentication and password
18025 management via Kerberos.
18026 You will need this service if you want PAM enabled applications to authenticate
18027 users using Kerberos.
18029 @defvr {Scheme Variable} pam-krb5-service-type
18030 A service type for the Kerberos 5 PAM module.
18033 @deftp {Data Type} pam-krb5-configuration
18034 Data type representing the configuration of the Kerberos 5 PAM module
18035 This type has the following parameters:
18037 @item @code{pam-krb5} (default: @code{pam-krb5})
18038 The pam-krb5 package to use.
18040 @item @code{minimum-uid} (default: @code{1000})
18041 The smallest user ID for which Kerberos authentications should be attempted.
18042 Local accounts with lower values will silently fail to authenticate.
18047 @node LDAP Services
18048 @subsection LDAP Services
18050 @cindex nslcd, LDAP service
18052 The @code{(gnu services authentication)} module provides the
18053 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
18054 server. In addition to configuring the service itself, you may want to add
18055 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
18056 Switch} for detailed information.
18058 Here is a simple operating system declaration with a default configuration of
18059 the @code{nslcd-service-type} and a Name Service Switch configuration that
18060 consults the @code{ldap} name service last:
18063 (use-service-modules authentication)
18064 (use-modules (gnu system nss))
18070 (service nslcd-service-type)
18071 (service dhcp-client-service-type)
18073 (name-service-switch
18074 (let ((services (list (name-service (name "db"))
18075 (name-service (name "files"))
18076 (name-service (name "ldap")))))
18077 (name-service-switch
18078 (inherit %mdns-host-lookup-nss)
18079 (password services)
18082 (netgroup services)
18083 (gshadow services)))))
18086 @c %start of generated documentation for nslcd-configuration
18088 Available @code{nslcd-configuration} fields are:
18090 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
18091 The @code{nss-pam-ldapd} package to use.
18095 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
18096 The number of threads to start that can handle requests and perform LDAP
18097 queries. Each thread opens a separate connection to the LDAP server.
18098 The default is to start 5 threads.
18100 Defaults to @samp{disabled}.
18104 @deftypevr {@code{nslcd-configuration} parameter} string uid
18105 This specifies the user id with which the daemon should be run.
18107 Defaults to @samp{"nslcd"}.
18111 @deftypevr {@code{nslcd-configuration} parameter} string gid
18112 This specifies the group id with which the daemon should be run.
18114 Defaults to @samp{"nslcd"}.
18118 @deftypevr {@code{nslcd-configuration} parameter} log-option log
18119 This option controls the way logging is done via a list containing
18120 SCHEME and LEVEL. The SCHEME argument may either be the symbols "none"
18121 or "syslog", or an absolute file name. The LEVEL argument is optional
18122 and specifies the log level. The log level may be one of the following
18123 symbols: "crit", "error", "warning", "notice", "info" or "debug". All
18124 messages with the specified log level or higher are logged.
18126 Defaults to @samp{("/var/log/nslcd" info)}.
18130 @deftypevr {@code{nslcd-configuration} parameter} list uri
18131 The list of LDAP server URIs. Normally, only the first server will be
18132 used with the following servers as fall-back.
18134 Defaults to @samp{("ldap://localhost:389/")}.
18138 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
18139 The version of the LDAP protocol to use. The default is to use the
18140 maximum version supported by the LDAP library.
18142 Defaults to @samp{disabled}.
18146 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
18147 Specifies the distinguished name with which to bind to the directory
18148 server for lookups. The default is to bind anonymously.
18150 Defaults to @samp{disabled}.
18154 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
18155 Specifies the credentials with which to bind. This option is only
18156 applicable when used with binddn.
18158 Defaults to @samp{disabled}.
18162 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
18163 Specifies the distinguished name to use when the root user tries to
18164 modify a user's password using the PAM module.
18166 Defaults to @samp{disabled}.
18170 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
18171 Specifies the credentials with which to bind if the root user tries to
18172 change a user's password. This option is only applicable when used with
18175 Defaults to @samp{disabled}.
18179 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
18180 Specifies the SASL mechanism to be used when performing SASL
18183 Defaults to @samp{disabled}.
18187 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
18188 Specifies the SASL realm to be used when performing SASL authentication.
18190 Defaults to @samp{disabled}.
18194 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
18195 Specifies the authentication identity to be used when performing SASL
18198 Defaults to @samp{disabled}.
18202 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
18203 Specifies the authorization identity to be used when performing SASL
18206 Defaults to @samp{disabled}.
18210 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
18211 Determines whether the LDAP server host name should be canonicalised. If
18212 this is enabled the LDAP library will do a reverse host name lookup. By
18213 default, it is left up to the LDAP library whether this check is
18216 Defaults to @samp{disabled}.
18220 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
18221 Set the name for the GSS-API Kerberos credentials cache.
18223 Defaults to @samp{disabled}.
18227 @deftypevr {@code{nslcd-configuration} parameter} string base
18228 The directory search base.
18230 Defaults to @samp{"dc=example,dc=com"}.
18234 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
18235 Specifies the search scope (subtree, onelevel, base or children). The
18236 default scope is subtree; base scope is almost never useful for name
18237 service lookups; children scope is not supported on all servers.
18239 Defaults to @samp{(subtree)}.
18243 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
18244 Specifies the policy for dereferencing aliases. The default policy is
18245 to never dereference aliases.
18247 Defaults to @samp{disabled}.
18251 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
18252 Specifies whether automatic referral chasing should be enabled. The
18253 default behaviour is to chase referrals.
18255 Defaults to @samp{disabled}.
18259 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
18260 This option allows for custom attributes to be looked up instead of the
18261 default RFC 2307 attributes. It is a list of maps, each consisting of
18262 the name of a map, the RFC 2307 attribute to match and the query
18263 expression for the attribute as it is available in the directory.
18265 Defaults to @samp{()}.
18269 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
18270 A list of filters consisting of the name of a map to which the filter
18271 applies and an LDAP search filter expression.
18273 Defaults to @samp{()}.
18277 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
18278 Specifies the time limit in seconds to use when connecting to the
18279 directory server. The default value is 10 seconds.
18281 Defaults to @samp{disabled}.
18285 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
18286 Specifies the time limit (in seconds) to wait for a response from the
18287 LDAP server. A value of zero, which is the default, is to wait
18288 indefinitely for searches to be completed.
18290 Defaults to @samp{disabled}.
18294 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
18295 Specifies the period if inactivity (in seconds) after which the con‐
18296 nection to the LDAP server will be closed. The default is not to time
18299 Defaults to @samp{disabled}.
18303 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
18304 Specifies the number of seconds to sleep when connecting to all LDAP
18305 servers fails. By default one second is waited between the first
18306 failure and the first retry.
18308 Defaults to @samp{disabled}.
18312 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
18313 Specifies the time after which the LDAP server is considered to be
18314 permanently unavailable. Once this time is reached retries will be done
18315 only once per this time period. The default value is 10 seconds.
18317 Defaults to @samp{disabled}.
18321 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
18322 Specifies whether to use SSL/TLS or not (the default is not to). If
18323 'start-tls is specified then StartTLS is used rather than raw LDAP over
18326 Defaults to @samp{disabled}.
18330 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
18331 Specifies what checks to perform on a server-supplied certificate. The
18332 meaning of the values is described in the ldap.conf(5) manual page.
18334 Defaults to @samp{disabled}.
18338 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
18339 Specifies the directory containing X.509 certificates for peer authen‐
18340 tication. This parameter is ignored when using GnuTLS.
18342 Defaults to @samp{disabled}.
18346 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
18347 Specifies the path to the X.509 certificate for peer authentication.
18349 Defaults to @samp{disabled}.
18353 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
18354 Specifies the path to an entropy source. This parameter is ignored when
18357 Defaults to @samp{disabled}.
18361 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
18362 Specifies the ciphers to use for TLS as a string.
18364 Defaults to @samp{disabled}.
18368 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
18369 Specifies the path to the file containing the local certificate for
18370 client TLS authentication.
18372 Defaults to @samp{disabled}.
18376 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
18377 Specifies the path to the file containing the private key for client TLS
18380 Defaults to @samp{disabled}.
18384 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
18385 Set this to a number greater than 0 to request paged results from the
18386 LDAP server in accordance with RFC2696. The default (0) is to not
18387 request paged results.
18389 Defaults to @samp{disabled}.
18393 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
18394 This option prevents group membership lookups through LDAP for the
18395 specified users. Alternatively, the value 'all-local may be used. With
18396 that value nslcd builds a full list of non-LDAP users on startup.
18398 Defaults to @samp{disabled}.
18402 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
18403 This option ensures that LDAP users with a numeric user id lower than
18404 the specified value are ignored.
18406 Defaults to @samp{disabled}.
18410 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
18411 This option specifies an offset that is added to all LDAP numeric user
18412 ids. This can be used to avoid user id collisions with local users.
18414 Defaults to @samp{disabled}.
18418 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
18419 This option specifies an offset that is added to all LDAP numeric group
18420 ids. This can be used to avoid user id collisions with local groups.
18422 Defaults to @samp{disabled}.
18426 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
18427 If this option is set, the member attribute of a group may point to
18428 another group. Members of nested groups are also returned in the higher
18429 level group and parent groups are returned when finding groups for a
18430 specific user. The default is not to perform extra searches for nested
18433 Defaults to @samp{disabled}.
18437 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
18438 If this option is set, the group member list is not retrieved when
18439 looking up groups. Lookups for finding which groups a user belongs to
18440 will remain functional so the user will likely still get the correct
18441 groups assigned on login.
18443 Defaults to @samp{disabled}.
18447 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
18448 If this option is set, functions which cause all user/group entries to
18449 be loaded from the directory will not succeed in doing so. This can
18450 dramatically reduce LDAP server load in situations where there are a
18451 great number of users and/or groups. This option is not recommended for
18452 most configurations.
18454 Defaults to @samp{disabled}.
18458 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
18459 This option can be used to specify how user and group names are verified
18460 within the system. This pattern is used to check all user and group
18461 names that are requested and returned from LDAP.
18463 Defaults to @samp{disabled}.
18467 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
18468 This specifies whether or not to perform searches using case-insensitive
18469 matching. Enabling this could open up the system to authorization
18470 bypass vulnerabilities and introduce nscd cache poisoning
18471 vulnerabilities which allow denial of service.
18473 Defaults to @samp{disabled}.
18477 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
18478 This option specifies whether password policy controls are requested and
18479 handled from the LDAP server when performing user authentication.
18481 Defaults to @samp{disabled}.
18485 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
18486 By default nslcd performs an LDAP search with the user's credentials
18487 after BIND (authentication) to ensure that the BIND operation was
18488 successful. The default search is a simple check to see if the user's
18489 DN exists. A search filter can be specified that will be used instead.
18490 It should return at least one entry.
18492 Defaults to @samp{disabled}.
18496 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
18497 This option allows flexible fine tuning of the authorisation check that
18498 should be performed. The search filter specified is executed and if any
18499 entries match, access is granted, otherwise access is denied.
18501 Defaults to @samp{disabled}.
18505 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
18506 If this option is set password modification using pam_ldap will be
18507 denied and the specified message will be presented to the user instead.
18508 The message can be used to direct the user to an alternative means of
18509 changing their password.
18511 Defaults to @samp{disabled}.
18515 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
18516 List of pam service names for which LDAP authentication should suffice.
18518 Defaults to @samp{()}.
18522 @c %end of generated documentation for nslcd-configuration
18526 @subsection Web Services
18531 The @code{(gnu services web)} module provides the Apache HTTP Server,
18532 the nginx web server, and also a fastcgi wrapper daemon.
18534 @subsubheading Apache HTTP Server
18536 @deffn {Scheme Variable} httpd-service-type
18537 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
18538 (@dfn{httpd}). The value for this service type is a
18539 @code{httpd-configuration} record.
18541 A simple example configuration is given below.
18544 (service httpd-service-type
18545 (httpd-configuration
18548 (server-name "www.example.com")
18549 (document-root "/srv/http/www.example.com")))))
18552 Other services can also extend the @code{httpd-service-type} to add to
18556 (simple-service 'my-extra-server httpd-service-type
18560 (list (string-append
18561 "ServerName "www.example.com
18562 DocumentRoot \"/srv/http/www.example.com\"")))))
18566 The details for the @code{httpd-configuration}, @code{httpd-module},
18567 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
18570 @deffn {Data Type} httpd-configuration
18571 This data type represents the configuration for the httpd service.
18574 @item @code{package} (default: @code{httpd})
18575 The httpd package to use.
18577 @item @code{pid-file} (default: @code{"/var/run/httpd"})
18578 The pid file used by the shepherd-service.
18580 @item @code{config} (default: @code{(httpd-config-file)})
18581 The configuration file to use with the httpd service. The default value
18582 is a @code{httpd-config-file} record, but this can also be a different
18583 G-expression that generates a file, for example a @code{plain-file}. A
18584 file outside of the store can also be specified through a string.
18589 @deffn {Data Type} httpd-module
18590 This data type represents a module for the httpd service.
18594 The name of the module.
18597 The file for the module. This can be relative to the httpd package being
18598 used, the absolute location of a file, or a G-expression for a file
18599 within the store, for example @code{(file-append mod-wsgi
18600 "/modules/mod_wsgi.so")}.
18605 @defvr {Scheme Variable} %default-httpd-modules
18606 A default list of @code{httpd-module} objects.
18609 @deffn {Data Type} httpd-config-file
18610 This data type represents a configuration file for the httpd service.
18613 @item @code{modules} (default: @code{%default-httpd-modules})
18614 The modules to load. Additional modules can be added here, or loaded by
18615 additional configuration.
18617 For example, in order to handle requests for PHP files, you can use Apache’s
18618 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
18621 (service httpd-service-type
18622 (httpd-configuration
18627 (name "proxy_module")
18628 (file "modules/mod_proxy.so"))
18630 (name "proxy_fcgi_module")
18631 (file "modules/mod_proxy_fcgi.so"))
18632 %default-httpd-modules))
18633 (extra-config (list "\
18634 <FilesMatch \\.php$>
18635 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
18636 </FilesMatch>"))))))
18637 (service php-fpm-service-type
18638 (php-fpm-configuration
18639 (socket "/var/run/php-fpm.sock")
18640 (socket-group "httpd")))
18643 @item @code{server-root} (default: @code{httpd})
18644 The @code{ServerRoot} in the configuration file, defaults to the httpd
18645 package. Directives including @code{Include} and @code{LoadModule} are
18646 taken as relative to the server root.
18648 @item @code{server-name} (default: @code{#f})
18649 The @code{ServerName} in the configuration file, used to specify the
18650 request scheme, hostname and port that the server uses to identify
18653 This doesn't need to be set in the server config, and can be specifyed
18654 in virtual hosts. The default is @code{#f} to not specify a
18657 @item @code{document-root} (default: @code{"/srv/http"})
18658 The @code{DocumentRoot} from which files will be served.
18660 @item @code{listen} (default: @code{'("80")})
18661 The list of values for the @code{Listen} directives in the config
18662 file. The value should be a list of strings, when each string can
18663 specify the port number to listen on, and optionally the IP address and
18666 @item @code{pid-file} (default: @code{"/var/run/httpd"})
18667 The @code{PidFile} to use. This should match the @code{pid-file} set in
18668 the @code{httpd-configuration} so that the Shepherd service is
18669 configured correctly.
18671 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
18672 The @code{ErrorLog} to which the server will log errors.
18674 @item @code{user} (default: @code{"httpd"})
18675 The @code{User} which the server will answer requests as.
18677 @item @code{group} (default: @code{"httpd"})
18678 The @code{Group} which the server will answer requests as.
18680 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
18681 A flat list of strings and G-expressions which will be added to the end
18682 of the configuration file.
18684 Any values which the service is extended with will be appended to this
18690 @deffn {Data Type} httpd-virtualhost
18691 This data type represents a virtualhost configuration block for the httpd service.
18693 These should be added to the extra-config for the httpd-service.
18696 (simple-service 'my-extra-server httpd-service-type
18700 (list (string-append
18701 "ServerName "www.example.com
18702 DocumentRoot \"/srv/http/www.example.com\"")))))
18706 @item @code{addresses-and-ports}
18707 The addresses and ports for the @code{VirtualHost} directive.
18709 @item @code{contents}
18710 The contents of the @code{VirtualHost} directive, this should be a list
18711 of strings and G-expressions.
18716 @subsubheading NGINX
18718 @deffn {Scheme Variable} nginx-service-type
18719 Service type for the @uref{https://nginx.org/,NGinx} web server. The
18720 value for this service type is a @code{<nginx-configuration>} record.
18722 A simple example configuration is given below.
18725 (service nginx-service-type
18726 (nginx-configuration
18728 (list (nginx-server-configuration
18729 (server-name '("www.example.com"))
18730 (root "/srv/http/www.example.com"))))))
18733 In addition to adding server blocks to the service configuration
18734 directly, this service can be extended by other services to add server
18735 blocks, as in this example:
18738 (simple-service 'my-extra-server nginx-service-type
18739 (list (nginx-server-configuration
18740 (root "/srv/http/extra-website")
18741 (try-files (list "$uri" "$uri/index.html")))))
18745 At startup, @command{nginx} has not yet read its configuration file, so
18746 it uses a default file to log error messages. If it fails to load its
18747 configuration file, that is where error messages are logged. After the
18748 configuration file is loaded, the default error log file changes as per
18749 configuration. In our case, startup error messages can be found in
18750 @file{/var/run/nginx/logs/error.log}, and after configuration in
18751 @file{/var/log/nginx/error.log}. The second location can be changed
18752 with the @var{log-directory} configuration option.
18754 @deffn {Data Type} nginx-configuration
18755 This data type represents the configuration for NGinx. Some
18756 configuration can be done through this and the other provided record
18757 types, or alternatively, a config file can be provided.
18760 @item @code{nginx} (default: @code{nginx})
18761 The nginx package to use.
18763 @item @code{log-directory} (default: @code{"/var/log/nginx"})
18764 The directory to which NGinx will write log files.
18766 @item @code{run-directory} (default: @code{"/var/run/nginx"})
18767 The directory in which NGinx will create a pid file, and write temporary
18770 @item @code{server-blocks} (default: @code{'()})
18771 A list of @dfn{server blocks} to create in the generated configuration
18772 file, the elements should be of type
18773 @code{<nginx-server-configuration>}.
18775 The following example would setup NGinx to serve @code{www.example.com}
18776 from the @code{/srv/http/www.example.com} directory, without using
18779 (service nginx-service-type
18780 (nginx-configuration
18782 (list (nginx-server-configuration
18783 (server-name '("www.example.com"))
18784 (root "/srv/http/www.example.com"))))))
18787 @item @code{upstream-blocks} (default: @code{'()})
18788 A list of @dfn{upstream blocks} to create in the generated configuration
18789 file, the elements should be of type
18790 @code{<nginx-upstream-configuration>}.
18792 Configuring upstreams through the @code{upstream-blocks} can be useful
18793 when combined with @code{locations} in the
18794 @code{<nginx-server-configuration>} records. The following example
18795 creates a server configuration with one location configuration, that
18796 will proxy requests to a upstream configuration, which will handle
18797 requests with two servers.
18802 (nginx-configuration
18804 (list (nginx-server-configuration
18805 (server-name '("www.example.com"))
18806 (root "/srv/http/www.example.com")
18809 (nginx-location-configuration
18811 (body '("proxy_pass http://server-proxy;"))))))))
18813 (list (nginx-upstream-configuration
18814 (name "server-proxy")
18815 (servers (list "server1.example.com"
18816 "server2.example.com")))))))
18819 @item @code{file} (default: @code{#f})
18820 If a configuration @var{file} is provided, this will be used, rather than
18821 generating a configuration file from the provided @code{log-directory},
18822 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
18823 proper operation, these arguments should match what is in @var{file} to ensure
18824 that the directories are created when the service is activated.
18826 This can be useful if you have an existing configuration file, or it's
18827 not possible to do what is required through the other parts of the
18828 nginx-configuration record.
18830 @item @code{server-names-hash-bucket-size} (default: @code{#f})
18831 Bucket size for the server names hash tables, defaults to @code{#f} to
18832 use the size of the processors cache line.
18834 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
18835 Maximum bucket size for the server names hash tables.
18837 @item @code{extra-content} (default: @code{""})
18838 Extra content for the @code{http} block. Should be string or a string
18839 valued G-expression.
18844 @deftp {Data Type} nginx-server-configuration
18845 Data type representing the configuration of an nginx server block.
18846 This type has the following parameters:
18849 @item @code{listen} (default: @code{'("80" "443 ssl")})
18850 Each @code{listen} directive sets the address and port for IP, or the
18851 path for a UNIX-domain socket on which the server will accept requests.
18852 Both address and port, or only address or only port can be specified.
18853 An address may also be a hostname, for example:
18856 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
18859 @item @code{server-name} (default: @code{(list 'default)})
18860 A list of server names this server represents. @code{'default} represents the
18861 default server for connections matching no other server.
18863 @item @code{root} (default: @code{"/srv/http"})
18864 Root of the website nginx will serve.
18866 @item @code{locations} (default: @code{'()})
18867 A list of @dfn{nginx-location-configuration} or
18868 @dfn{nginx-named-location-configuration} records to use within this
18871 @item @code{index} (default: @code{(list "index.html")})
18872 Index files to look for when clients ask for a directory. If it cannot be found,
18873 Nginx will send the list of files in the directory.
18875 @item @code{try-files} (default: @code{'()})
18876 A list of files whose existence is checked in the specified order.
18877 @code{nginx} will use the first file it finds to process the request.
18879 @item @code{ssl-certificate} (default: @code{#f})
18880 Where to find the certificate for secure connections. Set it to @code{#f} if
18881 you don't have a certificate or you don't want to use HTTPS.
18883 @item @code{ssl-certificate-key} (default: @code{#f})
18884 Where to find the private key for secure connections. Set it to @code{#f} if
18885 you don't have a key or you don't want to use HTTPS.
18887 @item @code{server-tokens?} (default: @code{#f})
18888 Whether the server should add its configuration to response.
18890 @item @code{raw-content} (default: @code{'()})
18891 A list of raw lines added to the server block.
18896 @deftp {Data Type} nginx-upstream-configuration
18897 Data type representing the configuration of an nginx @code{upstream}
18898 block. This type has the following parameters:
18902 Name for this group of servers.
18904 @item @code{servers}
18905 Specify the addresses of the servers in the group. The address can be
18906 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
18907 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
18908 prefix @samp{unix:}. For addresses using an IP address or domain name,
18909 the default port is 80, and a different port can be specified
18915 @deftp {Data Type} nginx-location-configuration
18916 Data type representing the configuration of an nginx @code{location}
18917 block. This type has the following parameters:
18921 URI which this location block matches.
18923 @anchor{nginx-location-configuration body}
18925 Body of the location block, specified as a list of strings. This can contain
18927 configuration directives. For example, to pass requests to a upstream
18928 server group defined using an @code{nginx-upstream-configuration} block,
18929 the following directive would be specified in the body @samp{(list "proxy_pass
18930 http://upstream-name;")}.
18935 @deftp {Data Type} nginx-named-location-configuration
18936 Data type representing the configuration of an nginx named location
18937 block. Named location blocks are used for request redirection, and not
18938 used for regular request processing. This type has the following
18943 Name to identify this location block.
18946 @xref{nginx-location-configuration body}, as the body for named location
18947 blocks can be used in a similar way to the
18948 @code{nginx-location-configuration body}. One restriction is that the
18949 body of a named location block cannot contain location blocks.
18954 @subsubheading Varnish Cache
18956 Varnish is a fast cache server that sits in between web applications
18957 and end users. It proxies requests from clients and caches the
18958 accessed URLs such that multiple requests for the same resource only
18959 creates one request to the back-end.
18961 @defvr {Scheme Variable} varnish-service-type
18962 Service type for the Varnish daemon.
18965 @deftp {Data Type} varnish-configuration
18966 Data type representing the @code{varnish} service configuration.
18967 This type has the following parameters:
18970 @item @code{package} (default: @code{varnish})
18971 The Varnish package to use.
18973 @item @code{name} (default: @code{"default"})
18974 A name for this Varnish instance. Varnish will create a directory in
18975 @file{/var/varnish/} with this name and keep temporary files there. If
18976 the name starts with a forward slash, it is interpreted as an absolute
18979 Pass the @code{-n} argument to other Varnish programs to connect to the
18980 named instance, e.g.@: @command{varnishncsa -n default}.
18982 @item @code{backend} (default: @code{"localhost:8080"})
18983 The backend to use. This option has no effect if @code{vcl} is set.
18985 @item @code{vcl} (default: #f)
18986 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
18987 is @code{#f}, Varnish will proxy @code{backend} using the default
18988 configuration. Otherwise this must be a file-like object with valid
18991 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
18992 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
18993 can do something along these lines:
18996 (define %gnu-mirror
19000 backend gnu @{ .host = "www.gnu.org"; @}"))
19004 (services (cons (service varnish-service-type
19005 (varnish-configuration
19007 (vcl %gnu-mirror)))
19011 The configuration of an already running Varnish instance can be inspected
19012 and changed using the @command{varnishadm} program.
19014 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
19015 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
19016 comprehensive documentation on Varnish and its configuration language.
19018 @item @code{listen} (default: @code{'("localhost:80")})
19019 List of addresses Varnish will listen on.
19021 @item @code{storage} (default: @code{'("malloc,128m")})
19022 List of storage backends that will be available in VCL.
19024 @item @code{parameters} (default: @code{'()})
19025 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
19027 @item @code{extra-options} (default: @code{'()})
19028 Additional arguments to pass to the @command{varnishd} process.
19033 @subsubheading FastCGI
19036 FastCGI is an interface between the front-end and the back-end of a web
19037 service. It is a somewhat legacy facility; new web services should
19038 generally just talk HTTP between the front-end and the back-end.
19039 However there are a number of back-end services such as PHP or the
19040 optimized HTTP Git repository access that use FastCGI, so we have
19041 support for it in Guix.
19043 To use FastCGI, you configure the front-end web server (e.g., nginx) to
19044 dispatch some subset of its requests to the fastcgi backend, which
19045 listens on a local TCP or UNIX socket. There is an intermediary
19046 @code{fcgiwrap} program that sits between the actual backend process and
19047 the web server. The front-end indicates which backend program to run,
19048 passing that information to the @code{fcgiwrap} process.
19050 @defvr {Scheme Variable} fcgiwrap-service-type
19051 A service type for the @code{fcgiwrap} FastCGI proxy.
19054 @deftp {Data Type} fcgiwrap-configuration
19055 Data type representing the configuration of the @code{fcgiwrap} service.
19056 This type has the following parameters:
19058 @item @code{package} (default: @code{fcgiwrap})
19059 The fcgiwrap package to use.
19061 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
19062 The socket on which the @code{fcgiwrap} process should listen, as a
19063 string. Valid @var{socket} values include
19064 @code{unix:@var{/path/to/unix/socket}},
19065 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
19066 @code{tcp6:[@var{ipv6_addr}]:port}.
19068 @item @code{user} (default: @code{fcgiwrap})
19069 @itemx @code{group} (default: @code{fcgiwrap})
19070 The user and group names, as strings, under which to run the
19071 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
19072 the user asks for the specific user or group names @code{fcgiwrap} that
19073 the corresponding user and/or group is present on the system.
19075 It is possible to configure a FastCGI-backed web service to pass HTTP
19076 authentication information from the front-end to the back-end, and to
19077 allow @code{fcgiwrap} to run the back-end process as a corresponding
19078 local user. To enable this capability on the back-end., run
19079 @code{fcgiwrap} as the @code{root} user and group. Note that this
19080 capability also has to be configured on the front-end as well.
19085 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
19086 with some additional features useful for sites of any size.
19088 These features include:
19090 @item Adaptive process spawning
19091 @item Basic statistics (similar to Apache's mod_status)
19092 @item Advanced process management with graceful stop/start
19093 @item Ability to start workers with different uid/gid/chroot/environment
19094 and different php.ini (replaces safe_mode)
19095 @item Stdout & stderr logging
19096 @item Emergency restart in case of accidental opcode cache destruction
19097 @item Accelerated upload support
19098 @item Support for a "slowlog"
19099 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
19100 a special function to finish request & flush all data while continuing to do
19101 something time-consuming (video converting, stats processing, etc.)
19103 ...@: and much more.
19105 @defvr {Scheme Variable} php-fpm-service-type
19106 A Service type for @code{php-fpm}.
19109 @deftp {Data Type} php-fpm-configuration
19110 Data Type for php-fpm service configuration.
19112 @item @code{php} (default: @code{php})
19113 The php package to use.
19114 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
19115 The address on which to accept FastCGI requests. Valid syntaxes are:
19117 @item @code{"ip.add.re.ss:port"}
19118 Listen on a TCP socket to a specific address on a specific port.
19119 @item @code{"port"}
19120 Listen on a TCP socket to all addresses on a specific port.
19121 @item @code{"/path/to/unix/socket"}
19122 Listen on a unix socket.
19125 @item @code{user} (default: @code{php-fpm})
19126 User who will own the php worker processes.
19127 @item @code{group} (default: @code{php-fpm})
19128 Group of the worker processes.
19129 @item @code{socket-user} (default: @code{php-fpm})
19130 User who can speak to the php-fpm socket.
19131 @item @code{socket-group} (default: @code{php-fpm})
19132 Group that can speak to the php-fpm socket.
19133 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
19134 The process id of the php-fpm process is written to this file
19135 once the service has started.
19136 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
19137 Log for the php-fpm master process.
19138 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
19139 Detailed settings for the php-fpm process manager.
19142 @item @code{<php-fpm-dynamic-process-manager-configuration>}
19143 @item @code{<php-fpm-static-process-manager-configuration>}
19144 @item @code{<php-fpm-on-demand-process-manager-configuration>}
19146 @item @code{display-errors} (default @code{#f})
19147 Determines whether php errors and warning should be sent to clients
19148 and displayed in their browsers.
19149 This is useful for local php development, but a security risk for public sites,
19150 as error messages can reveal passwords and personal data.
19151 @item @code{timezone} (default @code{#f})
19152 Specifies @code{php_admin_value[date.timezone]} parameter.
19153 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
19154 This file will log the @code{stderr} outputs of php worker processes.
19155 Can be set to @code{#f} to disable logging.
19156 @item @code{file} (default @code{#f})
19157 An optional override of the whole configuration.
19158 You can use the @code{mixed-text-file} function or an absolute filepath for it.
19162 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
19163 Data Type for the @code{dynamic} php-fpm process manager. With the
19164 @code{dynamic} process manager, spare worker processes are kept around
19165 based on it's configured limits.
19167 @item @code{max-children} (default: @code{5})
19168 Maximum of worker processes.
19169 @item @code{start-servers} (default: @code{2})
19170 How many worker processes should be started on start-up.
19171 @item @code{min-spare-servers} (default: @code{1})
19172 How many spare worker processes should be kept around at minimum.
19173 @item @code{max-spare-servers} (default: @code{3})
19174 How many spare worker processes should be kept around at maximum.
19178 @deftp {Data type} php-fpm-static-process-manager-configuration
19179 Data Type for the @code{static} php-fpm process manager. With the
19180 @code{static} process manager, an unchanging number of worker processes
19183 @item @code{max-children} (default: @code{5})
19184 Maximum of worker processes.
19188 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
19189 Data Type for the @code{on-demand} php-fpm process manager. With the
19190 @code{on-demand} process manager, worker processes are only created as
19193 @item @code{max-children} (default: @code{5})
19194 Maximum of worker processes.
19195 @item @code{process-idle-timeout} (default: @code{10})
19196 The time in seconds after which a process with no requests is killed.
19201 @deffn {Scheme Procedure} nginx-php-fpm-location @
19202 [#:nginx-package nginx] @
19203 [socket (string-append "/var/run/php" @
19204 (version-major (package-version php)) @
19206 A helper function to quickly add php to an @code{nginx-server-configuration}.
19209 A simple services setup for nginx with php can look like this:
19211 (services (cons* (service dhcp-client-service-type)
19212 (service php-fpm-service-type)
19213 (service nginx-service-type
19214 (nginx-server-configuration
19215 (server-name '("example.com"))
19216 (root "/srv/http/")
19218 (list (nginx-php-location)))
19220 (ssl-certificate #f)
19221 (ssl-certificate-key #f)))
19225 @cindex cat-avatar-generator
19226 The cat avatar generator is a simple service to demonstrate the use of php-fpm
19227 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
19228 the hash of a user's email address.
19230 @deffn {Scheme Procedure} cat-avatar-generator-service @
19231 [#:cache-dir "/var/cache/cat-avatar-generator"] @
19232 [#:package cat-avatar-generator] @
19233 [#:configuration (nginx-server-configuration)]
19234 Returns an nginx-server-configuration that inherits @code{configuration}. It
19235 extends the nginx configuration to add a server block that serves @code{package},
19236 a version of cat-avatar-generator. During execution, cat-avatar-generator will
19237 be able to use @code{cache-dir} as its cache directory.
19240 A simple setup for cat-avatar-generator can look like this:
19242 (services (cons* (cat-avatar-generator-service
19244 (nginx-server-configuration
19245 (server-name '("example.com"))))
19250 @subsubheading Hpcguix-web
19252 @cindex hpcguix-web
19253 The @uref{hpcguix-web, https://github.com/UMCUGenetics/hpcguix-web/}
19254 program is a customizable web interface to browse Guix packages,
19255 initially designed for users of high-performance computing (HPC)
19258 @defvr {Scheme Variable} hpcguix-web-service-type
19259 The service type for @code{hpcguix-web}.
19262 @deftp {Data Type} hpcguix-web-configuration
19263 Data type for the hpcguix-web service configuration.
19267 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
19268 configuration. The main items available in this spec are:
19271 @item @code{title-prefix} (default: @code{"hpcguix | "})
19272 The page title prefix.
19274 @item @code{guix-command} (default: @code{"guix"})
19275 The @command{guix} command.
19277 @item @code{package-filter-proc} (default: @code{(const #t)})
19278 A procedure specifying how to filter packages that are displayed.
19280 @item @code{package-page-extension-proc} (default: @code{(const '())})
19281 Extension package for @code{hpcguix-web}.
19283 @item @code{menu} (default: @code{'()})
19284 Additional entry in page @code{menu}.
19286 @item @code{channels} (default: @code{%default-channels})
19287 List of channels from which the package list is built (@pxref{Channels}).
19289 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
19290 The expiration time, in seconds, after which the package list is rebuilt from
19291 the latest instances of the given channels.
19294 See the hpcguix-web repository for a
19295 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
19298 @item @code{package} (default: @code{hpcguix-web})
19299 The hpcguix-web package to use.
19303 A typical hpcguix-web service declaration looks like this:
19306 (service hpcguix-web-service-type
19307 (hpcguix-web-configuration
19309 #~(define site-config
19310 (hpcweb-configuration
19311 (title-prefix "Guix-HPC - ")
19312 (menu '(("/about" "ABOUT"))))))))
19316 The hpcguix-web service periodically updates the package list it publishes by
19317 pulling channels from Git. To that end, it needs to access X.509 certificates
19318 so that it can authenticate Git servers when communicating over HTTPS, and it
19319 assumes that @file{/etc/ssl/certs} contains those certificates.
19321 Thus, make sure to add @code{nss-certs} or another certificate package to the
19322 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
19323 more information on X.509 certificates.
19326 @node Certificate Services
19327 @subsection Certificate Services
19330 @cindex HTTP, HTTPS
19331 @cindex Let's Encrypt
19332 @cindex TLS certificates
19333 The @code{(gnu services certbot)} module provides a service to
19334 automatically obtain a valid TLS certificate from the Let's Encrypt
19335 certificate authority. These certificates can then be used to serve
19336 content securely over HTTPS or other TLS-based protocols, with the
19337 knowledge that the client will be able to verify the server's
19340 @url{https://letsencrypt.org/, Let's Encrypt} provides the
19341 @code{certbot} tool to automate the certification process. This tool
19342 first securely generates a key on the server. It then makes a request
19343 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
19344 checks that the request originates from the host in question by using a
19345 challenge-response protocol, requiring the server to provide its
19346 response over HTTP. If that protocol completes successfully, the CA
19347 signs the key, resulting in a certificate. That certificate is valid
19348 for a limited period of time, and therefore to continue to provide TLS
19349 services, the server needs to periodically ask the CA to renew its
19352 The certbot service automates this process: the initial key
19353 generation, the initial certification request to the Let's Encrypt
19354 service, the web server challenge/response integration, writing the
19355 certificate to disk, the automated periodic renewals, and the deployment
19356 tasks associated with the renewal (e.g.@: reloading services, copying keys
19357 with different permissions).
19359 Certbot is run twice a day, at a random minute within the hour. It
19360 won't do anything until your certificates are due for renewal or
19361 revoked, but running it regularly would give your service a chance of
19362 staying online in case a Let's Encrypt-initiated revocation happened for
19365 By using this service, you agree to the ACME Subscriber Agreement, which
19366 can be found there:
19367 @url{https://acme-v01.api.letsencrypt.org/directory}.
19369 @defvr {Scheme Variable} certbot-service-type
19370 A service type for the @code{certbot} Let's Encrypt client. Its value
19371 must be a @code{certbot-configuration} record as in this example:
19374 (define %nginx-deploy-hook
19376 "nginx-deploy-hook"
19377 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
19378 (kill pid SIGHUP))))
19380 (service certbot-service-type
19381 (certbot-configuration
19382 (email "foo@@example.net")
19385 (certificate-configuration
19386 (domains '("example.net" "www.example.net"))
19387 (deploy-hook %nginx-deploy-hook))
19388 (certificate-configuration
19389 (domains '("bar.example.net")))))))
19392 See below for details about @code{certbot-configuration}.
19395 @deftp {Data Type} certbot-configuration
19396 Data type representing the configuration of the @code{certbot} service.
19397 This type has the following parameters:
19400 @item @code{package} (default: @code{certbot})
19401 The certbot package to use.
19403 @item @code{webroot} (default: @code{/var/www})
19404 The directory from which to serve the Let's Encrypt challenge/response
19407 @item @code{certificates} (default: @code{()})
19408 A list of @code{certificates-configuration}s for which to generate
19409 certificates and request signatures. Each certificate has a @code{name}
19410 and several @code{domains}.
19413 Mandatory email used for registration, recovery contact, and important
19414 account notifications.
19416 @item @code{rsa-key-size} (default: @code{2048})
19417 Size of the RSA key.
19419 @item @code{default-location} (default: @i{see below})
19420 The default @code{nginx-location-configuration}. Because @code{certbot}
19421 needs to be able to serve challenges and responses, it needs to be able
19422 to run a web server. It does so by extending the @code{nginx} web
19423 service with an @code{nginx-server-configuration} listening on the
19424 @var{domains} on port 80, and which has a
19425 @code{nginx-location-configuration} for the @code{/.well-known/} URI
19426 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
19427 these nginx configuration data types.
19429 Requests to other URL paths will be matched by the
19430 @code{default-location}, which if present is added to all
19431 @code{nginx-server-configuration}s.
19433 By default, the @code{default-location} will issue a redirect from
19434 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
19435 you to define what to serve on your site via @code{https}.
19437 Pass @code{#f} to not issue a default location.
19441 @deftp {Data Type} certificate-configuration
19442 Data type representing the configuration of a certificate.
19443 This type has the following parameters:
19446 @item @code{name} (default: @i{see below})
19447 This name is used by Certbot for housekeeping and in file paths; it
19448 doesn't affect the content of the certificate itself. To see
19449 certificate names, run @code{certbot certificates}.
19451 Its default is the first provided domain.
19453 @item @code{domains} (default: @code{()})
19454 The first domain provided will be the subject CN of the certificate, and
19455 all domains will be Subject Alternative Names on the certificate.
19457 @item @code{challenge} (default: @code{#f})
19458 The challenge type that has to be run by certbot. If @code{#f} is specified,
19459 default to the HTTP challenge. If a value is specified, defaults to the
19460 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
19461 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}).
19463 @item @code{authentication-hook} (default: @code{#f})
19464 Command to be run in a shell once for each certificate challenge to be
19465 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
19466 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
19467 contains the validation string and @code{$CERTBOT_TOKEN} contains the
19468 file name of the resource requested when performing an HTTP-01 challenge.
19470 @item @code{cleanup-hook} (default: @code{#f})
19471 Command to be run in a shell once for each certificate challenge that
19472 have been answered by the @code{auth-hook}. For this command, the shell
19473 variables available in the @code{auth-hook} script are still available, and
19474 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
19475 of the @code{auth-hook} script.
19477 @item @code{deploy-hook} (default: @code{#f})
19478 Command to be run in a shell once for each successfully issued
19479 certificate. For this command, the shell variable
19480 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
19481 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
19482 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
19483 contain a space-delimited list of renewed certificate domains (for
19484 example, @samp{"example.com www.example.com"}.
19489 For each @code{certificate-configuration}, the certificate is saved to
19490 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
19491 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
19493 @subsection DNS Services
19494 @cindex DNS (domain name system)
19495 @cindex domain name system (DNS)
19497 The @code{(gnu services dns)} module provides services related to the
19498 @dfn{domain name system} (DNS). It provides a server service for hosting
19499 an @emph{authoritative} DNS server for multiple zones, slave or master.
19500 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
19501 caching and forwarding DNS server for the LAN, which uses
19502 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
19504 @subsubheading Knot Service
19506 An example configuration of an authoritative server for two zones, one master
19510 (define-zone-entries example.org.zone
19511 ;; Name TTL Class Type Data
19512 ("@@" "" "IN" "A" "127.0.0.1")
19513 ("@@" "" "IN" "NS" "ns")
19514 ("ns" "" "IN" "A" "127.0.0.1"))
19516 (define master-zone
19517 (knot-zone-configuration
19518 (domain "example.org")
19520 (origin "example.org")
19521 (entries example.org.zone)))))
19524 (knot-zone-configuration
19525 (domain "plop.org")
19526 (dnssec-policy "default")
19527 (master (list "plop-master"))))
19529 (define plop-master
19530 (knot-remote-configuration
19532 (address (list "208.76.58.171"))))
19536 (services (cons* (service knot-service-type
19537 (knot-configuration
19538 (remotes (list plop-master))
19539 (zones (list master-zone slave-zone))))
19544 @deffn {Scheme Variable} knot-service-type
19545 This is the type for the Knot DNS server.
19547 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
19548 zones, that is to say domain names you would buy from a registrar. This server
19549 is not a resolver, meaning that it can only resolve names for which it is
19550 authoritative. This server can be configured to serve zones as a master server
19551 or a slave server as a per-zone basis. Slave zones will get their data from
19552 masters, and will serve it as an authoritative server. From the point of view
19553 of a resolver, there is no difference between master and slave.
19555 The following data types are used to configure the Knot DNS server:
19558 @deftp {Data Type} knot-key-configuration
19559 Data type representing a key.
19560 This type has the following parameters:
19563 @item @code{id} (default: @code{""})
19564 An identifier for other configuration fields to refer to this key. IDs must
19565 be unique and must not be empty.
19567 @item @code{algorithm} (default: @code{#f})
19568 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
19569 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
19570 and @code{'hmac-sha512}.
19572 @item @code{secret} (default: @code{""})
19573 The secret key itself.
19578 @deftp {Data Type} knot-acl-configuration
19579 Data type representing an Access Control List (ACL) configuration.
19580 This type has the following parameters:
19583 @item @code{id} (default: @code{""})
19584 An identifier for ether configuration fields to refer to this key. IDs must be
19585 unique and must not be empty.
19587 @item @code{address} (default: @code{'()})
19588 An ordered list of IP addresses, network subnets, or network ranges represented
19589 with strings. The query must match one of them. Empty value means that
19590 address match is not required.
19592 @item @code{key} (default: @code{'()})
19593 An ordered list of references to keys represented with strings. The string
19594 must match a key ID defined in a @code{knot-key-configuration}. No key means
19595 that a key is not require to match that ACL.
19597 @item @code{action} (default: @code{'()})
19598 An ordered list of actions that are permitted or forbidden by this ACL. Possible
19599 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
19600 and @code{'update}.
19602 @item @code{deny?} (default: @code{#f})
19603 When true, the ACL defines restrictions. Listed actions are forbidden. When
19604 false, listed actions are allowed.
19609 @deftp {Data Type} zone-entry
19610 Data type represnting a record entry in a zone file.
19611 This type has the following parameters:
19614 @item @code{name} (default: @code{"@@"})
19615 The name of the record. @code{"@@"} refers to the origin of the zone. Names
19616 are relative to the origin of the zone. For example, in the @code{example.org}
19617 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
19618 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
19619 refers to @code{ns.example.org}.
19621 @item @code{ttl} (default: @code{""})
19622 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
19624 @item @code{class} (default: @code{"IN"})
19625 The class of the record. Knot currently supports only @code{"IN"} and
19626 partially @code{"CH"}.
19628 @item @code{type} (default: @code{"A"})
19629 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
19630 address), NS (Name Server) and MX (Mail eXchange). Many other types are
19633 @item @code{data} (default: @code{""})
19634 The data contained in the record. For instance an IP address associated with
19635 an A record, or a domain name associated with an NS record. Remember that
19636 domain names are relative to the origin unless they end with a dot.
19641 @deftp {Data Type} zone-file
19642 Data type representing the content of a zone file.
19643 This type has the following parameters:
19646 @item @code{entries} (default: @code{'()})
19647 The list of entries. The SOA record is taken care of, so you don't need to
19648 put it in the list of entries. This list should probably contain an entry
19649 for your primary authoritative DNS server. Other than using a list of entries
19650 directly, you can use @code{define-zone-entries} to define a object containing
19651 the list of entries more easily, that you can later pass to the @code{entries}
19652 field of the @code{zone-file}.
19654 @item @code{origin} (default: @code{""})
19655 The name of your zone. This parameter cannot be empty.
19657 @item @code{ns} (default: @code{"ns"})
19658 The domain of your primary authoritative DNS server. The name is relative to
19659 the origin, unless it ends with a dot. It is mandatory that this primary
19660 DNS server corresponds to an NS record in the zone and that it is associated
19661 to an IP address in the list of entries.
19663 @item @code{mail} (default: @code{"hostmaster"})
19664 An email address people can contact you at, as the owner of the zone. This
19665 is translated as @code{<mail>@@<origin>}.
19667 @item @code{serial} (default: @code{1})
19668 The serial number of the zone. As this is used to keep track of changes by
19669 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
19670 Always increment it when you make a change in your zone.
19672 @item @code{refresh} (default: @code{(* 2 24 3600)})
19673 The frequency at which slaves will do a zone transfer. This value is a number
19674 of seconds. It can be computed by multiplications or with
19675 @code{(string->duration)}.
19677 @item @code{retry} (default: @code{(* 15 60)})
19678 The period after which a slave will retry to contact its master when it fails
19679 to do so a first time.
19681 @item @code{expiry} (default: @code{(* 14 24 3600)})
19682 Default TTL of records. Existing records are considered correct for at most
19683 this amount of time. After this period, resolvers will invalidate their cache
19684 and check again that it still exists.
19686 @item @code{nx} (default: @code{3600})
19687 Default TTL of inexistant records. This delay is usually short because you want
19688 your new domains to reach everyone quickly.
19693 @deftp {Data Type} knot-remote-configuration
19694 Data type representing a remote configuration.
19695 This type has the following parameters:
19698 @item @code{id} (default: @code{""})
19699 An identifier for other configuration fields to refer to this remote. IDs must
19700 be unique and must not be empty.
19702 @item @code{address} (default: @code{'()})
19703 An ordered list of destination IP addresses. Addresses are tried in sequence.
19704 An optional port can be given with the @@ separator. For instance:
19705 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
19707 @item @code{via} (default: @code{'()})
19708 An ordered list of source IP addresses. An empty list will have Knot choose
19709 an appropriate source IP. An optional port can be given with the @@ separator.
19710 The default is to choose at random.
19712 @item @code{key} (default: @code{#f})
19713 A reference to a key, that is a string containing the identifier of a key
19714 defined in a @code{knot-key-configuration} field.
19719 @deftp {Data Type} knot-keystore-configuration
19720 Data type representing a keystore to hold dnssec keys.
19721 This type has the following parameters:
19724 @item @code{id} (default: @code{""})
19725 The id of the keystore. It must not be empty.
19727 @item @code{backend} (default: @code{'pem})
19728 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
19730 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
19731 The configuration string of the backend. An example for the PKCS#11 is:
19732 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
19733 For the pem backend, the string reprensents a path in the file system.
19738 @deftp {Data Type} knot-policy-configuration
19739 Data type representing a dnssec policy. Knot DNS is able to automatically
19740 sign your zones. It can either generate and manage your keys automatically or
19741 use keys that you generate.
19743 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
19744 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
19745 zone. In order to be trusted, the KSK needs to be present in the parent zone
19746 (usually a top-level domain). If your registrar supports dnssec, you will
19747 have to send them your KSK's hash so they can add a DS record in their zone.
19748 This is not automated and need to be done each time you change your KSK.
19750 The policy also defines the lifetime of keys. Usually, ZSK can be changed
19751 easily and use weaker cryptographic functions (they use lower parameters) in
19752 order to sign records quickly, so they are changed often. The KSK however
19753 requires manual interaction with the registrar, so they are changed less often
19754 and use stronger parameters because they sign only one record.
19756 This type has the following parameters:
19759 @item @code{id} (default: @code{""})
19760 The id of the policy. It must not be empty.
19762 @item @code{keystore} (default: @code{"default"})
19763 A reference to a keystore, that is a string containing the identifier of a
19764 keystore defined in a @code{knot-keystore-configuration} field. The
19765 @code{"default"} identifier means the default keystore (a kasp database that
19766 was setup by this service).
19768 @item @code{manual?} (default: @code{#f})
19769 Whether the key management is manual or automatic.
19771 @item @code{single-type-signing?} (default: @code{#f})
19772 When @code{#t}, use the Single-Type Signing Scheme.
19774 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
19775 An algorithm of signing keys and issued signatures.
19777 @item @code{ksk-size} (default: @code{256})
19778 The length of the KSK. Note that this value is correct for the default
19779 algorithm, but would be unsecure for other algorithms.
19781 @item @code{zsk-size} (default: @code{256})
19782 The length of the ZSK. Note that this value is correct for the default
19783 algorithm, but would be unsecure for other algorithms.
19785 @item @code{dnskey-ttl} (default: @code{'default})
19786 The TTL value for DNSKEY records added into zone apex. The special
19787 @code{'default} value means same as the zone SOA TTL.
19789 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
19790 The period between ZSK publication and the next rollover initiation.
19792 @item @code{propagation-delay} (default: @code{(* 24 3600)})
19793 An extra delay added for each key rollover step. This value should be high
19794 enough to cover propagation of data from the master server to all slaves.
19796 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
19797 A validity period of newly issued signatures.
19799 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
19800 A period how long before a signature expiration the signature will be refreshed.
19802 @item @code{nsec3?} (default: @code{#f})
19803 When @code{#t}, NSEC3 will be used instead of NSEC.
19805 @item @code{nsec3-iterations} (default: @code{5})
19806 The number of additional times the hashing is performed.
19808 @item @code{nsec3-salt-length} (default: @code{8})
19809 The length of a salt field in octets, which is appended to the original owner
19810 name before hashing.
19812 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
19813 The validity period of newly issued salt field.
19818 @deftp {Data Type} knot-zone-configuration
19819 Data type representing a zone served by Knot.
19820 This type has the following parameters:
19823 @item @code{domain} (default: @code{""})
19824 The domain served by this configuration. It must not be empty.
19826 @item @code{file} (default: @code{""})
19827 The file where this zone is saved. This parameter is ignored by master zones.
19828 Empty means default location that depends on the domain name.
19830 @item @code{zone} (default: @code{(zone-file)})
19831 The content of the zone file. This parameter is ignored by slave zones. It
19832 must contain a zone-file record.
19834 @item @code{master} (default: @code{'()})
19835 A list of master remotes. When empty, this zone is a master. When set, this
19836 zone is a slave. This is a list of remotes identifiers.
19838 @item @code{ddns-master} (default: @code{#f})
19839 The main master. When empty, it defaults to the first master in the list of
19842 @item @code{notify} (default: @code{'()})
19843 A list of slave remote identifiers.
19845 @item @code{acl} (default: @code{'()})
19846 A list of acl identifiers.
19848 @item @code{semantic-checks?} (default: @code{#f})
19849 When set, this adds more semantic checks to the zone.
19851 @item @code{disable-any?} (default: @code{#f})
19852 When set, this forbids queries of the ANY type.
19854 @item @code{zonefile-sync} (default: @code{0})
19855 The delay between a modification in memory and on disk. 0 means immediate
19858 @item @code{zonefile-load} (default: @code{#f})
19859 The way the zone file contents are applied during zone load. Possible values
19863 @item @code{#f} for using the default value from Knot,
19864 @item @code{'none} for not using the zone file at all,
19865 @item @code{'difference} for computing the difference between already available
19866 contents and zone contents and applying it to the current zone contents,
19867 @item @code{'difference-no-serial} for the same as @code{'difference}, but
19868 ignoring the SOA serial in the zone file, while the server takes care of it
19870 @item @code{'whole} for loading zone contents from the zone file.
19873 @item @code{journal-content} (default: @code{#f})
19874 The way the journal is used to store zone and its changes. Possible values
19875 are @code{'none} to not use it at all, @code{'changes} to store changes and
19876 @code{'all} to store contents. @code{#f} does not set this option, so the
19877 default value from Knot is used.
19879 @item @code{max-journal-usage} (default: @code{#f})
19880 The maximum size for the journal on disk. @code{#f} does not set this option,
19881 so the default value from Knot is used.
19883 @item @code{max-journal-depth} (default: @code{#f})
19884 The maximum size of the history. @code{#f} does not set this option, so the
19885 default value from Knot is used.
19887 @item @code{max-zone-size} (default: @code{#f})
19888 The maximum size of the zone file. This limit is enforced for incoming
19889 transfer and updates. @code{#f} does not set this option, so the default
19890 value from Knot is used.
19892 @item @code{dnssec-policy} (default: @code{#f})
19893 A reference to a @code{knot-policy-configuration} record, or the special
19894 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
19897 @item @code{serial-policy} (default: @code{'increment})
19898 A policy between @code{'increment} and @code{'unixtime}.
19903 @deftp {Data Type} knot-configuration
19904 Data type representing the Knot configuration.
19905 This type has the following parameters:
19908 @item @code{knot} (default: @code{knot})
19911 @item @code{run-directory} (default: @code{"/var/run/knot"})
19912 The run directory. This directory will be used for pid file and sockets.
19914 @item @code{includes} (default: @code{'()})
19915 A list of strings or file-like objects denoting other files that must be
19916 included at the top of the configuration file.
19918 @cindex secrets, Knot service
19919 This can be used to manage secrets out-of-band. For example, secret
19920 keys may be stored in an out-of-band file not managed by Guix, and
19921 thus not visible in @file{/gnu/store}---e.g., you could store secret
19922 key configuration in @file{/etc/knot/secrets.conf} and add this file
19923 to the @code{includes} list.
19925 It can also be used to add configuration not supported by this interface.
19927 @item @code{listen-v4} (default: @code{"0.0.0.0"})
19928 An ip address on which to listen.
19930 @item @code{listen-v6} (default: @code{"::"})
19931 An ip address on which to listen.
19933 @item @code{listen-port} (default: @code{53})
19934 A port on which to listen.
19936 @item @code{keys} (default: @code{'()})
19937 The list of knot-key-configuration used by this configuration.
19939 @item @code{acls} (default: @code{'()})
19940 The list of knot-acl-configuration used by this configuration.
19942 @item @code{remotes} (default: @code{'()})
19943 The list of knot-remote-configuration used by this configuration.
19945 @item @code{zones} (default: @code{'()})
19946 The list of knot-zone-configuration used by this configuration.
19951 @subsubheading Dnsmasq Service
19953 @deffn {Scheme Variable} dnsmasq-service-type
19954 This is the type of the dnsmasq service, whose value should be an
19955 @code{dnsmasq-configuration} object as in this example:
19958 (service dnsmasq-service-type
19959 (dnsmasq-configuration
19961 (servers '("192.168.1.1"))))
19965 @deftp {Data Type} dnsmasq-configuration
19966 Data type representing the configuration of dnsmasq.
19969 @item @code{package} (default: @var{dnsmasq})
19970 Package object of the dnsmasq server.
19972 @item @code{no-hosts?} (default: @code{#f})
19973 When true, don't read the hostnames in /etc/hosts.
19975 @item @code{port} (default: @code{53})
19976 The port to listen on. Setting this to zero completely disables DNS
19977 responses, leaving only DHCP and/or TFTP functions.
19979 @item @code{local-service?} (default: @code{#t})
19980 Accept DNS queries only from hosts whose address is on a local subnet,
19981 ie a subnet for which an interface exists on the server.
19983 @item @code{listen-addresses} (default: @code{'()})
19984 Listen on the given IP addresses.
19986 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
19987 The file to read the IP address of the upstream nameservers from.
19989 @item @code{no-resolv?} (default: @code{#f})
19990 When true, don't read @var{resolv-file}.
19992 @item @code{servers} (default: @code{'()})
19993 Specify IP address of upstream servers directly.
19995 @item @code{cache-size} (default: @code{150})
19996 Set the size of dnsmasq's cache. Setting the cache size to zero
19999 @item @code{negative-cache?} (default: @code{#t})
20000 When false, disable negative caching.
20005 @subsubheading ddclient Service
20008 The ddclient service described below runs the ddclient daemon, which takes
20009 care of automatically updating DNS entries for service providers such as
20010 @uref{https://dyn.com/dns/, Dyn}.
20012 The following example show instantiates the service with its default
20016 (service ddclient-service-type)
20019 Note that ddclient needs to access credentials that are stored in a
20020 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
20021 @code{secret-file} below.) You are expected to create this file manually, in
20022 an ``out-of-band'' fashion (you @emph{could} make this file part of the
20023 service configuration, for instance by using @code{plain-file}, but it will be
20024 world-readable @i{via} @file{/gnu/store}.) See the examples in the
20025 @file{share/ddclient} directory of the @code{ddclient} package.
20027 @c %start of fragment
20029 Available @code{ddclient-configuration} fields are:
20031 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
20032 The ddclient package.
20036 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
20037 The period after which ddclient will retry to check IP and domain name.
20039 Defaults to @samp{300}.
20043 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
20044 Use syslog for the output.
20046 Defaults to @samp{#t}.
20050 @deftypevr {@code{ddclient-configuration} parameter} string mail
20053 Defaults to @samp{"root"}.
20057 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
20058 Mail failed update to user.
20060 Defaults to @samp{"root"}.
20064 @deftypevr {@code{ddclient-configuration} parameter} string pid
20065 The ddclient PID file.
20067 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
20071 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
20072 Enable SSL support.
20074 Defaults to @samp{#t}.
20078 @deftypevr {@code{ddclient-configuration} parameter} string user
20079 Specifies the user name or ID that is used when running ddclient
20082 Defaults to @samp{"ddclient"}.
20086 @deftypevr {@code{ddclient-configuration} parameter} string group
20087 Group of the user who will run the ddclient program.
20089 Defaults to @samp{"ddclient"}.
20093 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
20094 Secret file which will be appended to @file{ddclient.conf} file. This
20095 file contains credentials for use by ddclient. You are expected to
20096 create it manually.
20098 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
20102 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
20103 Extra options will be appended to @file{ddclient.conf} file.
20105 Defaults to @samp{()}.
20110 @c %end of fragment
20114 @subsection VPN Services
20115 @cindex VPN (virtual private network)
20116 @cindex virtual private network (VPN)
20118 The @code{(gnu services vpn)} module provides services related to
20119 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
20120 your machine to connect to a VPN, and a @emph{servire} service for your machine
20121 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
20123 @deffn {Scheme Procedure} openvpn-client-service @
20124 [#:config (openvpn-client-configuration)]
20126 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
20129 @deffn {Scheme Procedure} openvpn-server-service @
20130 [#:config (openvpn-server-configuration)]
20132 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
20134 Both can be run simultaneously.
20137 @c %automatically generated documentation
20139 Available @code{openvpn-client-configuration} fields are:
20141 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
20142 The OpenVPN package.
20146 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
20147 The OpenVPN pid file.
20149 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
20153 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
20154 The protocol (UDP or TCP) used to open a channel between clients and
20157 Defaults to @samp{udp}.
20161 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
20162 The device type used to represent the VPN connection.
20164 Defaults to @samp{tun}.
20168 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
20169 The certificate authority to check connections against.
20171 Defaults to @samp{"/etc/openvpn/ca.crt"}.
20175 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
20176 The certificate of the machine the daemon is running on. It should be
20177 signed by the authority given in @code{ca}.
20179 Defaults to @samp{"/etc/openvpn/client.crt"}.
20183 @deftypevr {@code{openvpn-client-configuration} parameter} string key
20184 The key of the machine the daemon is running on. It must be the key whose
20185 certificate is @code{cert}.
20187 Defaults to @samp{"/etc/openvpn/client.key"}.
20191 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
20192 Whether to use the lzo compression algorithm.
20194 Defaults to @samp{#t}.
20198 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
20199 Don't re-read key files across SIGUSR1 or --ping-restart.
20201 Defaults to @samp{#t}.
20205 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
20206 Don't close and reopen TUN/TAP device or run up/down scripts across
20207 SIGUSR1 or --ping-restart restarts.
20209 Defaults to @samp{#t}.
20213 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
20216 Defaults to @samp{3}.
20220 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
20221 Add an additional layer of HMAC authentication on top of the TLS control
20222 channel to protect against DoS attacks.
20224 Defaults to @samp{#f}.
20228 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
20229 Whether to check the server certificate has server usage extension.
20231 Defaults to @samp{#t}.
20235 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
20236 Bind to a specific local port number.
20238 Defaults to @samp{#f}.
20242 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
20243 Retry resolving server address.
20245 Defaults to @samp{#t}.
20249 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
20250 A list of remote servers to connect to.
20252 Defaults to @samp{()}.
20254 Available @code{openvpn-remote-configuration} fields are:
20256 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
20259 Defaults to @samp{"my-server"}.
20263 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
20264 Port number the server listens to.
20266 Defaults to @samp{1194}.
20271 @c %end of automatic openvpn-client documentation
20273 @c %automatically generated documentation
20275 Available @code{openvpn-server-configuration} fields are:
20277 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
20278 The OpenVPN package.
20282 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
20283 The OpenVPN pid file.
20285 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
20289 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
20290 The protocol (UDP or TCP) used to open a channel between clients and
20293 Defaults to @samp{udp}.
20297 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
20298 The device type used to represent the VPN connection.
20300 Defaults to @samp{tun}.
20304 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
20305 The certificate authority to check connections against.
20307 Defaults to @samp{"/etc/openvpn/ca.crt"}.
20311 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
20312 The certificate of the machine the daemon is running on. It should be
20313 signed by the authority given in @code{ca}.
20315 Defaults to @samp{"/etc/openvpn/client.crt"}.
20319 @deftypevr {@code{openvpn-server-configuration} parameter} string key
20320 The key of the machine the daemon is running on. It must be the key whose
20321 certificate is @code{cert}.
20323 Defaults to @samp{"/etc/openvpn/client.key"}.
20327 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
20328 Whether to use the lzo compression algorithm.
20330 Defaults to @samp{#t}.
20334 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
20335 Don't re-read key files across SIGUSR1 or --ping-restart.
20337 Defaults to @samp{#t}.
20341 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
20342 Don't close and reopen TUN/TAP device or run up/down scripts across
20343 SIGUSR1 or --ping-restart restarts.
20345 Defaults to @samp{#t}.
20349 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
20352 Defaults to @samp{3}.
20356 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
20357 Add an additional layer of HMAC authentication on top of the TLS control
20358 channel to protect against DoS attacks.
20360 Defaults to @samp{#f}.
20364 @deftypevr {@code{openvpn-server-configuration} parameter} number port
20365 Specifies the port number on which the server listens.
20367 Defaults to @samp{1194}.
20371 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
20372 An ip and mask specifying the subnet inside the virtual network.
20374 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
20378 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
20379 A CIDR notation specifying the IPv6 subnet inside the virtual network.
20381 Defaults to @samp{#f}.
20385 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
20386 The Diffie-Hellman parameters file.
20388 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
20392 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
20393 The file that records client IPs.
20395 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
20399 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
20400 When true, the server will act as a gateway for its clients.
20402 Defaults to @samp{#f}.
20406 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
20407 When true, clients are allowed to talk to each other inside the VPN.
20409 Defaults to @samp{#f}.
20413 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
20414 Causes ping-like messages to be sent back and forth over the link so
20415 that each side knows when the other side has gone down. @code{keepalive}
20416 requires a pair. The first element is the period of the ping sending,
20417 and the second element is the timeout before considering the other side
20422 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
20423 The maximum number of clients.
20425 Defaults to @samp{100}.
20429 @deftypevr {@code{openvpn-server-configuration} parameter} string status
20430 The status file. This file shows a small report on current connection.
20431 It is truncated and rewritten every minute.
20433 Defaults to @samp{"/var/run/openvpn/status"}.
20437 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
20438 The list of configuration for some clients.
20440 Defaults to @samp{()}.
20442 Available @code{openvpn-ccd-configuration} fields are:
20444 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
20447 Defaults to @samp{"client"}.
20451 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
20454 Defaults to @samp{#f}.
20458 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
20461 Defaults to @samp{#f}.
20468 @c %end of automatic openvpn-server documentation
20471 @node Network File System
20472 @subsection Network File System
20475 The @code{(gnu services nfs)} module provides the following services,
20476 which are most commonly used in relation to mounting or exporting
20477 directory trees as @dfn{network file systems} (NFS).
20479 @subsubheading RPC Bind Service
20482 The RPC Bind service provides a facility to map program numbers into
20483 universal addresses.
20484 Many NFS related services use this facility. Hence it is automatically
20485 started when a dependent service starts.
20487 @defvr {Scheme Variable} rpcbind-service-type
20488 A service type for the RPC portmapper daemon.
20492 @deftp {Data Type} rpcbind-configuration
20493 Data type representing the configuration of the RPC Bind Service.
20494 This type has the following parameters:
20496 @item @code{rpcbind} (default: @code{rpcbind})
20497 The rpcbind package to use.
20499 @item @code{warm-start?} (default: @code{#t})
20500 If this parameter is @code{#t}, then the daemon will read a
20501 state file on startup thus reloading state information saved by a previous
20507 @subsubheading Pipefs Pseudo File System
20511 The pipefs file system is used to transfer NFS related data
20512 between the kernel and user space programs.
20514 @defvr {Scheme Variable} pipefs-service-type
20515 A service type for the pipefs pseudo file system.
20518 @deftp {Data Type} pipefs-configuration
20519 Data type representing the configuration of the pipefs pseudo file system service.
20520 This type has the following parameters:
20522 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20523 The directory to which the file system is to be attached.
20528 @subsubheading GSS Daemon Service
20531 @cindex global security system
20533 The @dfn{global security system} (GSS) daemon provides strong security for RPC
20535 Before exchanging RPC requests an RPC client must establish a security
20536 context. Typically this is done using the Kerberos command @command{kinit}
20537 or automatically at login time using PAM services (@pxref{Kerberos Services}).
20539 @defvr {Scheme Variable} gss-service-type
20540 A service type for the Global Security System (GSS) daemon.
20543 @deftp {Data Type} gss-configuration
20544 Data type representing the configuration of the GSS daemon service.
20545 This type has the following parameters:
20547 @item @code{nfs-utils} (default: @code{nfs-utils})
20548 The package in which the @command{rpc.gssd} command is to be found.
20550 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20551 The directory where the pipefs file system is mounted.
20557 @subsubheading IDMAP Daemon Service
20559 @cindex name mapper
20561 The idmap daemon service provides mapping between user IDs and user names.
20562 Typically it is required in order to access file systems mounted via NFSv4.
20564 @defvr {Scheme Variable} idmap-service-type
20565 A service type for the Identity Mapper (IDMAP) daemon.
20568 @deftp {Data Type} idmap-configuration
20569 Data type representing the configuration of the IDMAP daemon service.
20570 This type has the following parameters:
20572 @item @code{nfs-utils} (default: @code{nfs-utils})
20573 The package in which the @command{rpc.idmapd} command is to be found.
20575 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20576 The directory where the pipefs file system is mounted.
20578 @item @code{domain} (default: @code{#f})
20579 The local NFSv4 domain name.
20580 This must be a string or @code{#f}.
20581 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
20586 @node Continuous Integration
20587 @subsection Continuous Integration
20589 @cindex continuous integration
20590 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
20591 continuous integration tool for Guix. It can be used both for development and
20592 for providing substitutes to others (@pxref{Substitutes}).
20594 The @code{(gnu services cuirass)} module provides the following service.
20596 @defvr {Scheme Procedure} cuirass-service-type
20597 The type of the Cuirass service. Its value must be a
20598 @code{cuirass-configuration} object, as described below.
20601 To add build jobs, you have to set the @code{specifications} field of the
20602 configuration. Here is an example of a service that polls the Guix repository
20603 and builds the packages from a manifest. Some of the packages are defined in
20604 the @code{"custom-packages"} input, which is the equivalent of
20605 @code{GUIX_PACKAGE_PATH}.
20608 (define %cuirass-specs
20610 '((#:name . "my-manifest")
20611 (#:load-path-inputs . ("guix"))
20612 (#:package-path-inputs . ("custom-packages"))
20613 (#:proc-input . "guix")
20614 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
20615 (#:proc . cuirass-jobs)
20616 (#:proc-args . ((subset . "manifests")
20617 (systems . ("x86_64-linux"))
20618 (manifests . (("config" . "guix/manifest.scm")))))
20619 (#:inputs . (((#:name . "guix")
20620 (#:url . "git://git.savannah.gnu.org/guix.git")
20621 (#:load-path . ".")
20622 (#:branch . "master")
20623 (#:no-compile? . #t))
20624 ((#:name . "config")
20625 (#:url . "git://git.example.org/config.git")
20626 (#:load-path . ".")
20627 (#:branch . "master")
20628 (#:no-compile? . #t))
20629 ((#:name . "custom-packages")
20630 (#:url . "git://git.example.org/custom-packages.git")
20631 (#:load-path . ".")
20632 (#:branch . "master")
20633 (#:no-compile? . #t)))))))
20635 (service cuirass-service-type
20636 (cuirass-configuration
20637 (specifications %cuirass-specs)))
20640 While information related to build jobs is located directly in the
20641 specifications, global settings for the @command{cuirass} process are
20642 accessible in other @code{cuirass-configuration} fields.
20644 @deftp {Data Type} cuirass-configuration
20645 Data type representing the configuration of Cuirass.
20648 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
20649 Location of the log file.
20651 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
20652 Location of the repository cache.
20654 @item @code{user} (default: @code{"cuirass"})
20655 Owner of the @code{cuirass} process.
20657 @item @code{group} (default: @code{"cuirass"})
20658 Owner's group of the @code{cuirass} process.
20660 @item @code{interval} (default: @code{60})
20661 Number of seconds between the poll of the repositories followed by the
20664 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
20665 Location of sqlite database which contains the build results and previously
20666 added specifications.
20668 @item @code{ttl} (default: @code{(* 30 24 3600)})
20669 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
20670 are registered for build results. This means that build results are protected
20671 from garbage collection for at least @var{ttl} seconds.
20673 @item @code{port} (default: @code{8081})
20674 Port number used by the HTTP server.
20676 @item --listen=@var{host}
20677 Listen on the network interface for @var{host}. The default is to
20678 accept connections from localhost.
20680 @item @code{specifications} (default: @code{#~'()})
20681 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
20682 where a specification is an association list
20683 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
20684 keys are keywords (@code{#:keyword-example}) as shown in the example
20687 @item @code{use-substitutes?} (default: @code{#f})
20688 This allows using substitutes to avoid building every dependencies of a job
20691 @item @code{one-shot?} (default: @code{#f})
20692 Only evaluate specifications and build derivations once.
20694 @item @code{fallback?} (default: @code{#f})
20695 When substituting a pre-built binary fails, fall back to building
20698 @item @code{cuirass} (default: @code{cuirass})
20699 The Cuirass package to use.
20703 @node Power Management Services
20704 @subsection Power Management Services
20707 @cindex power management with TLP
20708 @subsubheading TLP daemon
20710 The @code{(gnu services pm)} module provides a Guix service definition
20711 for the Linux power management tool TLP.
20713 TLP enables various powersaving modes in userspace and kernel.
20714 Contrary to @code{upower-service}, it is not a passive,
20715 monitoring tool, as it will apply custom settings each time a new power
20716 source is detected. More information can be found at
20717 @uref{http://linrunner.de/en/tlp/tlp.html, TLP home page}.
20719 @deffn {Scheme Variable} tlp-service-type
20720 The service type for the TLP tool. Its value should be a valid
20721 TLP configuration (see below). To use the default settings, simply
20724 (service tlp-service-type)
20728 By default TLP does not need much configuration but most TLP parameters
20729 can be tweaked using @code{tlp-configuration}.
20731 Each parameter definition is preceded by its type; for example,
20732 @samp{boolean foo} indicates that the @code{foo} parameter
20733 should be specified as a boolean. Types starting with
20734 @code{maybe-} denote parameters that won't show up in TLP config file
20735 when their value is @code{'disabled}.
20737 @c The following documentation was initially generated by
20738 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
20739 @c documentation is better, so we shouldn't hesitate to edit below as
20740 @c needed. However if the change you want to make to this documentation
20741 @c can be done in an automated way, it's probably easier to change
20742 @c (generate-documentation) than to make it below and have to deal with
20743 @c the churn as TLP updates.
20745 Available @code{tlp-configuration} fields are:
20747 @deftypevr {@code{tlp-configuration} parameter} package tlp
20752 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
20753 Set to true if you wish to enable TLP.
20755 Defaults to @samp{#t}.
20759 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
20760 Default mode when no power supply can be detected. Alternatives are AC
20763 Defaults to @samp{"AC"}.
20767 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
20768 Number of seconds Linux kernel has to wait after the disk goes idle,
20769 before syncing on AC.
20771 Defaults to @samp{0}.
20775 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
20776 Same as @code{disk-idle-ac} but on BAT mode.
20778 Defaults to @samp{2}.
20782 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
20783 Dirty pages flushing periodicity, expressed in seconds.
20785 Defaults to @samp{15}.
20789 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
20790 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
20792 Defaults to @samp{60}.
20796 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
20797 CPU frequency scaling governor on AC mode. With intel_pstate driver,
20798 alternatives are powersave and performance. With acpi-cpufreq driver,
20799 alternatives are ondemand, powersave, performance and conservative.
20801 Defaults to @samp{disabled}.
20805 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
20806 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
20808 Defaults to @samp{disabled}.
20812 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
20813 Set the min available frequency for the scaling governor on AC.
20815 Defaults to @samp{disabled}.
20819 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
20820 Set the max available frequency for the scaling governor on AC.
20822 Defaults to @samp{disabled}.
20826 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
20827 Set the min available frequency for the scaling governor on BAT.
20829 Defaults to @samp{disabled}.
20833 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
20834 Set the max available frequency for the scaling governor on BAT.
20836 Defaults to @samp{disabled}.
20840 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
20841 Limit the min P-state to control the power dissipation of the CPU, in AC
20842 mode. Values are stated as a percentage of the available performance.
20844 Defaults to @samp{disabled}.
20848 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
20849 Limit the max P-state to control the power dissipation of the CPU, in AC
20850 mode. Values are stated as a percentage of the available performance.
20852 Defaults to @samp{disabled}.
20856 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
20857 Same as @code{cpu-min-perf-on-ac} on BAT mode.
20859 Defaults to @samp{disabled}.
20863 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
20864 Same as @code{cpu-max-perf-on-ac} on BAT mode.
20866 Defaults to @samp{disabled}.
20870 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
20871 Enable CPU turbo boost feature on AC mode.
20873 Defaults to @samp{disabled}.
20877 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
20878 Same as @code{cpu-boost-on-ac?} on BAT mode.
20880 Defaults to @samp{disabled}.
20884 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
20885 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
20886 used under light load conditions.
20888 Defaults to @samp{#f}.
20892 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
20893 Same as @code{sched-powersave-on-ac?} but on BAT mode.
20895 Defaults to @samp{#t}.
20899 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
20900 Enable Linux kernel NMI watchdog.
20902 Defaults to @samp{#f}.
20906 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
20907 For Linux kernels with PHC patch applied, change CPU voltages. An
20908 example value would be @samp{"F:V F:V F:V F:V"}.
20910 Defaults to @samp{disabled}.
20914 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
20915 Set CPU performance versus energy saving policy on AC. Alternatives are
20916 performance, normal, powersave.
20918 Defaults to @samp{"performance"}.
20922 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
20923 Same as @code{energy-perf-policy-ac} but on BAT mode.
20925 Defaults to @samp{"powersave"}.
20929 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
20934 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
20935 Hard disk advanced power management level.
20939 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
20940 Same as @code{disk-apm-bat} but on BAT mode.
20944 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
20945 Hard disk spin down timeout. One value has to be specified for each
20946 declared hard disk.
20948 Defaults to @samp{disabled}.
20952 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
20953 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
20955 Defaults to @samp{disabled}.
20959 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
20960 Select IO scheduler for disk devices. One value has to be specified for
20961 each declared hard disk. Example alternatives are cfq, deadline and
20964 Defaults to @samp{disabled}.
20968 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
20969 SATA aggressive link power management (ALPM) level. Alternatives are
20970 min_power, medium_power, max_performance.
20972 Defaults to @samp{"max_performance"}.
20976 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
20977 Same as @code{sata-linkpwr-ac} but on BAT mode.
20979 Defaults to @samp{"min_power"}.
20983 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
20984 Exclude specified SATA host devices for link power management.
20986 Defaults to @samp{disabled}.
20990 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
20991 Enable Runtime Power Management for AHCI controller and disks on AC
20994 Defaults to @samp{disabled}.
20998 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
20999 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
21001 Defaults to @samp{disabled}.
21005 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
21006 Seconds of inactivity before disk is suspended.
21008 Defaults to @samp{15}.
21012 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
21013 PCI Express Active State Power Management level. Alternatives are
21014 default, performance, powersave.
21016 Defaults to @samp{"performance"}.
21020 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
21021 Same as @code{pcie-aspm-ac} but on BAT mode.
21023 Defaults to @samp{"powersave"}.
21027 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
21028 Radeon graphics clock speed level. Alternatives are low, mid, high,
21031 Defaults to @samp{"high"}.
21035 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
21036 Same as @code{radeon-power-ac} but on BAT mode.
21038 Defaults to @samp{"low"}.
21042 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
21043 Radeon dynamic power management method (DPM). Alternatives are battery,
21046 Defaults to @samp{"performance"}.
21050 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
21051 Same as @code{radeon-dpm-state-ac} but on BAT mode.
21053 Defaults to @samp{"battery"}.
21057 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
21058 Radeon DPM performance level. Alternatives are auto, low, high.
21060 Defaults to @samp{"auto"}.
21064 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
21065 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
21067 Defaults to @samp{"auto"}.
21071 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
21072 Wifi power saving mode.
21074 Defaults to @samp{#f}.
21078 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
21079 Same as @code{wifi-power-ac?} but on BAT mode.
21081 Defaults to @samp{#t}.
21085 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
21086 Disable wake on LAN.
21088 Defaults to @samp{#t}.
21092 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
21093 Timeout duration in seconds before activating audio power saving on
21094 Intel HDA and AC97 devices. A value of 0 disables power saving.
21096 Defaults to @samp{0}.
21100 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
21101 Same as @code{sound-powersave-ac} but on BAT mode.
21103 Defaults to @samp{1}.
21107 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
21108 Disable controller in powersaving mode on Intel HDA devices.
21110 Defaults to @samp{#t}.
21114 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
21115 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
21116 powered on again by releasing (and reinserting) the eject lever or by
21117 pressing the disc eject button on newer models.
21119 Defaults to @samp{#f}.
21123 @deftypevr {@code{tlp-configuration} parameter} string bay-device
21124 Name of the optical drive device to power off.
21126 Defaults to @samp{"sr0"}.
21130 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
21131 Runtime Power Management for PCI(e) bus devices. Alternatives are on
21134 Defaults to @samp{"on"}.
21138 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
21139 Same as @code{runtime-pm-ac} but on BAT mode.
21141 Defaults to @samp{"auto"}.
21145 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
21146 Runtime Power Management for all PCI(e) bus devices, except blacklisted
21149 Defaults to @samp{#t}.
21153 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
21154 Exclude specified PCI(e) device addresses from Runtime Power Management.
21156 Defaults to @samp{disabled}.
21160 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
21161 Exclude PCI(e) devices assigned to the specified drivers from Runtime
21166 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
21167 Enable USB autosuspend feature.
21169 Defaults to @samp{#t}.
21173 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
21174 Exclude specified devices from USB autosuspend.
21176 Defaults to @samp{disabled}.
21180 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
21181 Exclude WWAN devices from USB autosuspend.
21183 Defaults to @samp{#t}.
21187 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
21188 Include specified devices into USB autosuspend, even if they are already
21189 excluded by the driver or via @code{usb-blacklist-wwan?}.
21191 Defaults to @samp{disabled}.
21195 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
21196 Enable USB autosuspend before shutdown.
21198 Defaults to @samp{disabled}.
21202 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
21203 Restore radio device state (bluetooth, wifi, wwan) from previous
21204 shutdown on system startup.
21206 Defaults to @samp{#f}.
21211 @cindex CPU frequency scaling with thermald
21212 @subsubheading Thermald daemon
21214 The @code{(gnu services pm)} module provides an interface to
21215 thermald, a CPU frequency scaling service which helps prevent overheating.
21217 @defvr {Scheme Variable} thermald-service-type
21218 This is the service type for
21219 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
21220 Thermal Daemon, which is responsible for controlling the thermal state
21221 of processors and preventing overheating.
21224 @deftp {Data Type} thermald-configuration
21225 Data type representing the configuration of @code{thermald-service-type}.
21228 @item @code{ignore-cpuid-check?} (default: @code{#f})
21229 Ignore cpuid check for supported CPU models.
21231 @item @code{thermald} (default: @var{thermald})
21232 Package object of thermald.
21237 @node Audio Services
21238 @subsection Audio Services
21240 The @code{(gnu services audio)} module provides a service to start MPD
21241 (the Music Player Daemon).
21244 @subsubheading Music Player Daemon
21246 The Music Player Daemon (MPD) is a service that can play music while
21247 being controlled from the local machine or over the network by a variety
21250 The following example shows how one might run @code{mpd} as user
21251 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
21254 (service mpd-service-type
21260 @defvr {Scheme Variable} mpd-service-type
21261 The service type for @command{mpd}
21264 @deftp {Data Type} mpd-configuration
21265 Data type representing the configuration of @command{mpd}.
21268 @item @code{user} (default: @code{"mpd"})
21269 The user to run mpd as.
21271 @item @code{music-dir} (default: @code{"~/Music"})
21272 The directory to scan for music files.
21274 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
21275 The directory to store playlists.
21277 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
21278 The location of the music database.
21280 @item @code{state-file} (default: @code{"~/.mpd/state"})
21281 The location of the file that stores current MPD's state.
21283 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
21284 The location of the sticker database.
21286 @item @code{port} (default: @code{"6600"})
21287 The port to run mpd on.
21289 @item @code{address} (default: @code{"any"})
21290 The address that mpd will bind to. To use a Unix domain socket,
21291 an absolute path can be specified here.
21296 @node Virtualization Services
21297 @subsection Virtualization services
21299 The @code{(gnu services virtualization)} module provides services for
21300 the libvirt and virtlog daemons, as well as other virtualization-related
21303 @subsubheading Libvirt daemon
21304 @code{libvirtd} is the server side daemon component of the libvirt
21305 virtualization management system. This daemon runs on host servers
21306 and performs required management tasks for virtualized guests.
21308 @deffn {Scheme Variable} libvirt-service-type
21309 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
21310 Its value must be a @code{libvirt-configuration}.
21313 (service libvirt-service-type
21314 (libvirt-configuration
21315 (unix-sock-group "libvirt")
21316 (tls-port "16555")))
21320 @c Auto-generated with (generate-libvirt-documentation)
21321 Available @code{libvirt-configuration} fields are:
21323 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
21328 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
21329 Flag listening for secure TLS connections on the public TCP/IP port.
21330 must set @code{listen} for this to have any effect.
21332 It is necessary to setup a CA and issue server certificates before using
21335 Defaults to @samp{#t}.
21339 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
21340 Listen for unencrypted TCP connections on the public TCP/IP port. must
21341 set @code{listen} for this to have any effect.
21343 Using the TCP socket requires SASL authentication by default. Only SASL
21344 mechanisms which support data encryption are allowed. This is
21345 DIGEST_MD5 and GSSAPI (Kerberos5)
21347 Defaults to @samp{#f}.
21351 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
21352 Port for accepting secure TLS connections This can be a port number, or
21355 Defaults to @samp{"16514"}.
21359 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
21360 Port for accepting insecure TCP connections This can be a port number,
21363 Defaults to @samp{"16509"}.
21367 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
21368 IP address or hostname used for client connections.
21370 Defaults to @samp{"0.0.0.0"}.
21374 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
21375 Flag toggling mDNS advertisement of the libvirt service.
21377 Alternatively can disable for all services on a host by stopping the
21380 Defaults to @samp{#f}.
21384 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
21385 Default mDNS advertisement name. This must be unique on the immediate
21388 Defaults to @samp{"Virtualization Host <hostname>"}.
21392 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
21393 UNIX domain socket group ownership. This can be used to allow a
21394 'trusted' set of users access to management capabilities without
21397 Defaults to @samp{"root"}.
21401 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
21402 UNIX socket permissions for the R/O socket. This is used for monitoring
21405 Defaults to @samp{"0777"}.
21409 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
21410 UNIX socket permissions for the R/W socket. Default allows only root.
21411 If PolicyKit is enabled on the socket, the default will change to allow
21412 everyone (eg, 0777)
21414 Defaults to @samp{"0770"}.
21418 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
21419 UNIX socket permissions for the admin socket. Default allows only owner
21420 (root), do not change it unless you are sure to whom you are exposing
21423 Defaults to @samp{"0777"}.
21427 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
21428 The directory in which sockets will be found/created.
21430 Defaults to @samp{"/var/run/libvirt"}.
21434 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
21435 Authentication scheme for UNIX read-only sockets. By default socket
21436 permissions allow anyone to connect
21438 Defaults to @samp{"polkit"}.
21442 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
21443 Authentication scheme for UNIX read-write sockets. By default socket
21444 permissions only allow root. If PolicyKit support was compiled into
21445 libvirt, the default will be to use 'polkit' auth.
21447 Defaults to @samp{"polkit"}.
21451 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
21452 Authentication scheme for TCP sockets. If you don't enable SASL, then
21453 all TCP traffic is cleartext. Don't do this outside of a dev/test
21456 Defaults to @samp{"sasl"}.
21460 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
21461 Authentication scheme for TLS sockets. TLS sockets already have
21462 encryption provided by the TLS layer, and limited authentication is done
21465 It is possible to make use of any SASL authentication mechanism as well,
21466 by using 'sasl' for this option
21468 Defaults to @samp{"none"}.
21472 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
21473 API access control scheme.
21475 By default an authenticated user is allowed access to all APIs. Access
21476 drivers can place restrictions on this.
21478 Defaults to @samp{()}.
21482 @deftypevr {@code{libvirt-configuration} parameter} string key-file
21483 Server key file path. If set to an empty string, then no private key is
21486 Defaults to @samp{""}.
21490 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
21491 Server key file path. If set to an empty string, then no certificate is
21494 Defaults to @samp{""}.
21498 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
21499 Server key file path. If set to an empty string, then no CA certificate
21502 Defaults to @samp{""}.
21506 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
21507 Certificate revocation list path. If set to an empty string, then no
21510 Defaults to @samp{""}.
21514 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
21515 Disable verification of our own server certificates.
21517 When libvirtd starts it performs some sanity checks against its own
21520 Defaults to @samp{#f}.
21524 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
21525 Disable verification of client certificates.
21527 Client certificate verification is the primary authentication mechanism.
21528 Any client which does not present a certificate signed by the CA will be
21531 Defaults to @samp{#f}.
21535 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
21536 Whitelist of allowed x509 Distinguished Name.
21538 Defaults to @samp{()}.
21542 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
21543 Whitelist of allowed SASL usernames. The format for username depends on
21544 the SASL authentication mechanism.
21546 Defaults to @samp{()}.
21550 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
21551 Override the compile time default TLS priority string. The default is
21552 usually "NORMAL" unless overridden at build time. Only set this is it
21553 is desired for libvirt to deviate from the global default settings.
21555 Defaults to @samp{"NORMAL"}.
21559 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
21560 Maximum number of concurrent client connections to allow over all
21563 Defaults to @samp{5000}.
21567 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
21568 Maximum length of queue of connections waiting to be accepted by the
21569 daemon. Note, that some protocols supporting retransmission may obey
21570 this so that a later reattempt at connection succeeds.
21572 Defaults to @samp{1000}.
21576 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
21577 Maximum length of queue of accepted but not yet authenticated clients.
21578 Set this to zero to turn this feature off
21580 Defaults to @samp{20}.
21584 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
21585 Number of workers to start up initially.
21587 Defaults to @samp{5}.
21591 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
21592 Maximum number of worker threads.
21594 If the number of active clients exceeds @code{min-workers}, then more
21595 threads are spawned, up to max_workers limit. Typically you'd want
21596 max_workers to equal maximum number of clients allowed.
21598 Defaults to @samp{20}.
21602 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
21603 Number of priority workers. If all workers from above pool are stuck,
21604 some calls marked as high priority (notably domainDestroy) can be
21605 executed in this pool.
21607 Defaults to @samp{5}.
21611 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
21612 Total global limit on concurrent RPC calls.
21614 Defaults to @samp{20}.
21618 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
21619 Limit on concurrent requests from a single client connection. To avoid
21620 one client monopolizing the server this should be a small fraction of
21621 the global max_requests and max_workers parameter.
21623 Defaults to @samp{5}.
21627 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
21628 Same as @code{min-workers} but for the admin interface.
21630 Defaults to @samp{1}.
21634 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
21635 Same as @code{max-workers} but for the admin interface.
21637 Defaults to @samp{5}.
21641 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
21642 Same as @code{max-clients} but for the admin interface.
21644 Defaults to @samp{5}.
21648 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
21649 Same as @code{max-queued-clients} but for the admin interface.
21651 Defaults to @samp{5}.
21655 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
21656 Same as @code{max-client-requests} but for the admin interface.
21658 Defaults to @samp{5}.
21662 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
21663 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
21665 Defaults to @samp{3}.
21669 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
21672 A filter allows to select a different logging level for a given category
21673 of logs The format for a filter is one of:
21684 where @code{name} is a string which is matched against the category
21685 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
21686 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
21687 be a substring of the full category name, in order to match multiple
21688 similar categories), the optional "+" prefix tells libvirt to log stack
21689 trace for each message matching name, and @code{x} is the minimal level
21690 where matching messages should be logged:
21707 Multiple filters can be defined in a single filters statement, they just
21708 need to be separated by spaces.
21710 Defaults to @samp{"3:remote 4:event"}.
21714 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
21717 An output is one of the places to save logging information The format
21718 for an output can be:
21722 output goes to stderr
21724 @item x:syslog:name
21725 use syslog for the output and use the given name as the ident
21727 @item x:file:file_path
21728 output to a file, with the given filepath
21731 output to journald logging system
21735 In all case the x prefix is the minimal level, acting as a filter
21752 Multiple outputs can be defined, they just need to be separated by
21755 Defaults to @samp{"3:stderr"}.
21759 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
21760 Allows usage of the auditing subsystem to be altered
21764 0: disable all auditing
21767 1: enable auditing, only if enabled on host
21770 2: enable auditing, and exit if disabled on host.
21774 Defaults to @samp{1}.
21778 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
21779 Send audit messages via libvirt logging infrastructure.
21781 Defaults to @samp{#f}.
21785 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
21786 Host UUID. UUID must not have all digits be the same.
21788 Defaults to @samp{""}.
21792 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
21793 Source to read host UUID.
21797 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
21800 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
21804 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
21807 Defaults to @samp{"smbios"}.
21811 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
21812 A keepalive message is sent to a client after @code{keepalive_interval}
21813 seconds of inactivity to check if the client is still responding. If
21814 set to -1, libvirtd will never send keepalive requests; however clients
21815 can still send them and the daemon will send responses.
21817 Defaults to @samp{5}.
21821 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
21822 Maximum number of keepalive messages that are allowed to be sent to the
21823 client without getting any response before the connection is considered
21826 In other words, the connection is automatically closed approximately
21827 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
21828 the last message received from the client. When @code{keepalive-count}
21829 is set to 0, connections will be automatically closed after
21830 @code{keepalive-interval} seconds of inactivity without sending any
21831 keepalive messages.
21833 Defaults to @samp{5}.
21837 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
21838 Same as above but for admin interface.
21840 Defaults to @samp{5}.
21844 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
21845 Same as above but for admin interface.
21847 Defaults to @samp{5}.
21851 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
21852 Timeout for Open vSwitch calls.
21854 The @code{ovs-vsctl} utility is used for the configuration and its
21855 timeout option is set by default to 5 seconds to avoid potential
21856 infinite waits blocking libvirt.
21858 Defaults to @samp{5}.
21862 @c %end of autogenerated docs
21864 @subsubheading Virtlog daemon
21865 The virtlogd service is a server side daemon component of libvirt that is
21866 used to manage logs from virtual machine consoles.
21868 This daemon is not used directly by libvirt client applications, rather it
21869 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
21870 standalone daemon, the main @code{libvirtd} daemon can be restarted without
21871 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
21872 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
21874 @deffn {Scheme Variable} virtlog-service-type
21875 This is the type of the virtlog daemon.
21876 Its value must be a @code{virtlog-configuration}.
21879 (service virtlog-service-type
21880 (virtlog-configuration
21881 (max-clients 1000)))
21885 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
21886 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
21888 Defaults to @samp{3}.
21892 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
21895 A filter allows to select a different logging level for a given category
21896 of logs The format for a filter is one of:
21907 where @code{name} is a string which is matched against the category
21908 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
21909 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
21910 be a substring of the full category name, in order to match multiple
21911 similar categories), the optional "+" prefix tells libvirt to log stack
21912 trace for each message matching name, and @code{x} is the minimal level
21913 where matching messages should be logged:
21930 Multiple filters can be defined in a single filters statement, they just
21931 need to be separated by spaces.
21933 Defaults to @samp{"3:remote 4:event"}.
21937 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
21940 An output is one of the places to save logging information The format
21941 for an output can be:
21945 output goes to stderr
21947 @item x:syslog:name
21948 use syslog for the output and use the given name as the ident
21950 @item x:file:file_path
21951 output to a file, with the given filepath
21954 output to journald logging system
21958 In all case the x prefix is the minimal level, acting as a filter
21975 Multiple outputs can be defined, they just need to be separated by
21978 Defaults to @samp{"3:stderr"}.
21982 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
21983 Maximum number of concurrent client connections to allow over all
21986 Defaults to @samp{1024}.
21990 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
21991 Maximum file size before rolling over.
21993 Defaults to @samp{2MB}
21997 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
21998 Maximum number of backup files to keep.
22000 Defaults to @samp{3}
22004 @subsubheading Transparent Emulation with QEMU
22007 @cindex @code{binfmt_misc}
22008 @code{qemu-binfmt-service-type} provides support for transparent
22009 emulation of program binaries built for different architectures---e.g.,
22010 it allows you to transparently execute an ARMv7 program on an x86_64
22011 machine. It achieves this by combining the @uref{https://www.qemu.org,
22012 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
22014 @defvr {Scheme Variable} qemu-binfmt-service-type
22015 This is the type of the QEMU/binfmt service for transparent emulation.
22016 Its value must be a @code{qemu-binfmt-configuration} object, which
22017 specifies the QEMU package to use as well as the architecture we want to
22021 (service qemu-binfmt-service-type
22022 (qemu-binfmt-configuration
22023 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
22026 In this example, we enable transparent emulation for the ARM and aarch64
22027 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
22028 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
22029 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
22032 @deftp {Data Type} qemu-binfmt-configuration
22033 This is the configuration for the @code{qemu-binfmt} service.
22036 @item @code{platforms} (default: @code{'()})
22037 The list of emulated QEMU platforms. Each item must be a @dfn{platform
22038 object} as returned by @code{lookup-qemu-platforms} (see below).
22040 @item @code{guix-support?} (default: @code{#f})
22041 When it is true, QEMU and all its dependencies are added to the build
22042 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
22043 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
22044 handlers to be used within the build environment, which in turn means
22045 that you can transparently build programs for another architecture.
22047 For example, let's suppose you're on an x86_64 machine and you have this
22051 (service qemu-binfmt-service-type
22052 (qemu-binfmt-configuration
22053 (platforms (lookup-qemu-platforms "arm"))
22054 (guix-support? #t)))
22060 guix build -s armhf-linux inkscape
22064 and it will build Inkscape for ARMv7 @emph{as if it were a native
22065 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
22066 if you'd like to test a package build for an architecture you don't have
22069 @item @code{qemu} (default: @code{qemu})
22070 The QEMU package to use.
22074 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
22075 Return the list of QEMU platform objects corresponding to
22076 @var{platforms}@dots{}. @var{platforms} must be a list of strings
22077 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
22078 @code{"mips64el"}, and so on.
22081 @deffn {Scheme Procedure} qemu-platform? @var{obj}
22082 Return true if @var{obj} is a platform object.
22085 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
22086 Return the name of @var{platform}---a string such as @code{"arm"}.
22089 @node Version Control Services
22090 @subsection Version Control Services
22092 The @code{(gnu services version-control)} module provides a service to
22093 allow remote access to local Git repositories. There are three options:
22094 the @code{git-daemon-service}, which provides access to repositories via
22095 the @code{git://} unsecured TCP-based protocol, extending the
22096 @code{nginx} web server to proxy some requests to
22097 @code{git-http-backend}, or providing a web interface with
22098 @code{cgit-service-type}.
22100 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
22102 Return a service that runs @command{git daemon}, a simple TCP server to
22103 expose repositories over the Git protocol for anonymous access.
22105 The optional @var{config} argument should be a
22106 @code{<git-daemon-configuration>} object, by default it allows read-only
22107 access to exported@footnote{By creating the magic file
22108 "git-daemon-export-ok" in the repository directory.} repositories under
22113 @deftp {Data Type} git-daemon-configuration
22114 Data type representing the configuration for @code{git-daemon-service}.
22117 @item @code{package} (default: @var{git})
22118 Package object of the Git distributed version control system.
22120 @item @code{export-all?} (default: @var{#f})
22121 Whether to allow access for all Git repositories, even if they do not
22122 have the @file{git-daemon-export-ok} file.
22124 @item @code{base-path} (default: @file{/srv/git})
22125 Whether to remap all the path requests as relative to the given path.
22126 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
22127 then if you later try to pull @code{git://example.com/hello.git}, git
22128 daemon will interpret the path as @code{/srv/git/hello.git}.
22130 @item @code{user-path} (default: @var{#f})
22131 Whether to allow @code{~user} notation to be used in requests. When
22132 specified with empty string, requests to @code{git://host/~alice/foo} is
22133 taken as a request to access @code{foo} repository in the home directory
22134 of user @code{alice}. If @var{(user-path "path")} is specified, the
22135 same request is taken as a request to access @code{path/foo} repository
22136 in the home directory of user @code{alice}.
22138 @item @code{listen} (default: @var{'()})
22139 Whether to listen on specific IP addresses or hostnames, defaults to
22142 @item @code{port} (default: @var{#f})
22143 Whether to listen on an alternative port, which defaults to 9418.
22145 @item @code{whitelist} (default: @var{'()})
22146 If not empty, only allow access to this list of directories.
22148 @item @code{extra-options} (default: @var{'()})
22149 Extra options will be passed to @code{git daemon}, please run
22150 @command{man git-daemon} for more information.
22155 The @code{git://} protocol lacks authentication. When you pull from a
22156 repository fetched via @code{git://}, you don't know that the data you
22157 receive was modified is really coming from the specified host, and you
22158 have your connection is subject to eavesdropping. It's better to use an
22159 authenticated and encrypted transport, such as @code{https}. Although Git allows you
22160 to serve repositories using unsophisticated file-based web servers,
22161 there is a faster protocol implemented by the @code{git-http-backend}
22162 program. This program is the back-end of a proper Git web service. It
22163 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
22164 on running the necessary @code{fcgiwrap} daemon.
22166 Guix has a separate configuration data type for serving Git repositories
22169 @deftp {Data Type} git-http-configuration
22170 Data type representing the configuration for @code{git-http-service}.
22173 @item @code{package} (default: @var{git})
22174 Package object of the Git distributed version control system.
22176 @item @code{git-root} (default: @file{/srv/git})
22177 Directory containing the Git repositories to expose to the world.
22179 @item @code{export-all?} (default: @var{#f})
22180 Whether to expose access for all Git repositories in @var{git-root},
22181 even if they do not have the @file{git-daemon-export-ok} file.
22183 @item @code{uri-path} (default: @file{/git/})
22184 Path prefix for Git access. With the default @code{/git/} prefix, this
22185 will map @code{http://@var{server}/git/@var{repo}.git} to
22186 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
22187 with this prefix are not passed on to this Git instance.
22189 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
22190 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
22195 There is no @code{git-http-service-type}, currently; instead you can
22196 create an @code{nginx-location-configuration} from a
22197 @code{git-http-configuration} and then add that location to a web
22200 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
22201 [config=(git-http-configuration)]
22202 Compute an @code{nginx-location-configuration} that corresponds to the
22203 given Git http configuration. An example nginx service definition to
22204 serve the default @file{/srv/git} over HTTPS might be:
22207 (service nginx-service-type
22208 (nginx-configuration
22211 (nginx-server-configuration
22212 (listen '("443 ssl"))
22213 (server-name "git.my-host.org")
22215 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
22216 (ssl-certificate-key
22217 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
22220 (git-http-nginx-location-configuration
22221 (git-http-configuration (uri-path "/"))))))))))
22224 This example assumes that you are using Let's Encrypt to get your TLS
22225 certificate. @xref{Certificate Services}. The default @code{certbot}
22226 service will redirect all HTTP traffic on @code{git.my-host.org} to
22227 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
22228 system services. @xref{Web Services}.
22231 @subsubheading Cgit Service
22233 @cindex Cgit service
22234 @cindex Git, web interface
22235 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
22236 repositories written in C.
22238 The following example will configure the service with default values.
22239 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
22242 (service cgit-service-type)
22245 The @code{file-object} type designates either a file-like object
22246 (@pxref{G-Expressions, file-like objects}) or a string.
22248 @c %start of fragment
22250 Available @code{cgit-configuration} fields are:
22252 @deftypevr {@code{cgit-configuration} parameter} package package
22257 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
22258 NGINX configuration.
22262 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
22263 Specifies a command which will be invoked to format the content of about
22264 pages (both top-level and for each repository).
22266 Defaults to @samp{""}.
22270 @deftypevr {@code{cgit-configuration} parameter} string agefile
22271 Specifies a path, relative to each repository path, which can be used to
22272 specify the date and time of the youngest commit in the repository.
22274 Defaults to @samp{""}.
22278 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
22279 Specifies a command that will be invoked for authenticating repository
22282 Defaults to @samp{""}.
22286 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
22287 Flag which, when set to @samp{age}, enables date ordering in the branch
22288 ref list, and when set @samp{name} enables ordering by branch name.
22290 Defaults to @samp{"name"}.
22294 @deftypevr {@code{cgit-configuration} parameter} string cache-root
22295 Path used to store the cgit cache entries.
22297 Defaults to @samp{"/var/cache/cgit"}.
22301 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
22302 Number which specifies the time-to-live, in minutes, for the cached
22303 version of repository pages accessed with a fixed SHA1.
22305 Defaults to @samp{-1}.
22309 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
22310 Number which specifies the time-to-live, in minutes, for the cached
22311 version of repository pages accessed without a fixed SHA1.
22313 Defaults to @samp{5}.
22317 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
22318 Number which specifies the time-to-live, in minutes, for the cached
22319 version of the repository summary page.
22321 Defaults to @samp{5}.
22325 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
22326 Number which specifies the time-to-live, in minutes, for the cached
22327 version of the repository index page.
22329 Defaults to @samp{5}.
22333 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
22334 Number which specifies the time-to-live, in minutes, for the result of
22335 scanning a path for Git repositories.
22337 Defaults to @samp{15}.
22341 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
22342 Number which specifies the time-to-live, in minutes, for the cached
22343 version of the repository about page.
22345 Defaults to @samp{15}.
22349 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
22350 Number which specifies the time-to-live, in minutes, for the cached
22351 version of snapshots.
22353 Defaults to @samp{5}.
22357 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
22358 The maximum number of entries in the cgit cache. When set to @samp{0},
22359 caching is disabled.
22361 Defaults to @samp{0}.
22365 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
22366 Sort items in the repo list case sensitively.
22368 Defaults to @samp{#t}.
22372 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
22373 List of common prefixes which, when combined with a repository URL,
22374 generates valid clone URLs for the repository.
22376 Defaults to @samp{()}.
22380 @deftypevr {@code{cgit-configuration} parameter} list clone-url
22381 List of @code{clone-url} templates.
22383 Defaults to @samp{()}.
22387 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
22388 Command which will be invoked to format commit messages.
22390 Defaults to @samp{""}.
22394 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
22395 Flag which, when set to @samp{date}, enables strict date ordering in the
22396 commit log, and when set to @samp{topo} enables strict topological
22399 Defaults to @samp{"git log"}.
22403 @deftypevr {@code{cgit-configuration} parameter} file-object css
22404 URL which specifies the css document to include in all cgit pages.
22406 Defaults to @samp{"/share/cgit/cgit.css"}.
22410 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
22411 Specifies a command which will be invoked to format names and email
22412 address of committers, authors, and taggers, as represented in various
22413 places throughout the cgit interface.
22415 Defaults to @samp{""}.
22419 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
22420 Flag which, when set to @samp{#t}, will make cgit generate a HTML
22421 fragment suitable for embedding in other HTML pages.
22423 Defaults to @samp{#f}.
22427 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
22428 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
22429 commit history graph to the left of the commit messages in the
22430 repository log page.
22432 Defaults to @samp{#f}.
22436 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
22437 Flag which, when set to @samp{#t}, allows all filter settings to be
22438 overridden in repository-specific cgitrc files.
22440 Defaults to @samp{#f}.
22444 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
22445 Flag which, when set to @samp{#t}, allows users to follow a file in the
22448 Defaults to @samp{#f}.
22452 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
22453 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
22456 Defaults to @samp{#t}.
22460 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
22461 Flag which, when set to @samp{#t}, will make cgit generate extra links
22462 "summary", "commit", "tree" for each repo in the repository index.
22464 Defaults to @samp{#f}.
22468 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
22469 Flag which, when set to @samp{#t}, will make cgit display the owner of
22470 each repo in the repository index.
22472 Defaults to @samp{#t}.
22476 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
22477 Flag which, when set to @samp{#t}, will make cgit print the number of
22478 modified files for each commit on the repository log page.
22480 Defaults to @samp{#f}.
22484 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
22485 Flag which, when set to @samp{#t}, will make cgit print the number of
22486 added and removed lines for each commit on the repository log page.
22488 Defaults to @samp{#f}.
22492 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
22493 Flag which, when set to @code{#t}, will make cgit display remote
22494 branches in the summary and refs views.
22496 Defaults to @samp{#f}.
22500 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
22501 Flag which, when set to @code{1}, will make cgit use the subject of the
22502 parent commit as link text when generating links to parent commits in
22505 Defaults to @samp{#f}.
22509 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
22510 Flag which, when set to @samp{#t}, will make cgit use the subject of the
22511 parent commit as link text when generating links to parent commits in
22514 Defaults to @samp{#f}.
22518 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
22519 Flag which, when set to @samp{#t}, will make cgit generate linenumber
22520 links for plaintext blobs printed in the tree view.
22522 Defaults to @samp{#t}.
22526 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
22527 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
22528 set any repo specific settings.
22530 Defaults to @samp{#f}.
22534 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
22535 URL used as link to a shortcut icon for cgit.
22537 Defaults to @samp{"/favicon.ico"}.
22541 @deftypevr {@code{cgit-configuration} parameter} string footer
22542 The content of the file specified with this option will be included
22543 verbatim at the bottom of all pages (i.e.@: it replaces the standard
22544 "generated by..."@: message).
22546 Defaults to @samp{""}.
22550 @deftypevr {@code{cgit-configuration} parameter} string head-include
22551 The content of the file specified with this option will be included
22552 verbatim in the HTML HEAD section on all pages.
22554 Defaults to @samp{""}.
22558 @deftypevr {@code{cgit-configuration} parameter} string header
22559 The content of the file specified with this option will be included
22560 verbatim at the top of all pages.
22562 Defaults to @samp{""}.
22566 @deftypevr {@code{cgit-configuration} parameter} file-object include
22567 Name of a configfile to include before the rest of the current config-
22570 Defaults to @samp{""}.
22574 @deftypevr {@code{cgit-configuration} parameter} string index-header
22575 The content of the file specified with this option will be included
22576 verbatim above the repository index.
22578 Defaults to @samp{""}.
22582 @deftypevr {@code{cgit-configuration} parameter} string index-info
22583 The content of the file specified with this option will be included
22584 verbatim below the heading on the repository index page.
22586 Defaults to @samp{""}.
22590 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
22591 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
22592 in the servers timezone.
22594 Defaults to @samp{#f}.
22598 @deftypevr {@code{cgit-configuration} parameter} file-object logo
22599 URL which specifies the source of an image which will be used as a logo
22602 Defaults to @samp{"/share/cgit/cgit.png"}.
22606 @deftypevr {@code{cgit-configuration} parameter} string logo-link
22607 URL loaded when clicking on the cgit logo image.
22609 Defaults to @samp{""}.
22613 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
22614 Command which will be invoked to format the Owner column of the main
22617 Defaults to @samp{""}.
22621 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
22622 Number of items to display in atom feeds view.
22624 Defaults to @samp{10}.
22628 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
22629 Number of entries to list per page in "log" view.
22631 Defaults to @samp{50}.
22635 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
22636 Number of commit message characters to display in "log" view.
22638 Defaults to @samp{80}.
22642 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
22643 Specifies the number of entries to list per page on the repository index
22646 Defaults to @samp{50}.
22650 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
22651 Specifies the maximum number of repo description characters to display
22652 on the repository index page.
22654 Defaults to @samp{80}.
22658 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
22659 Specifies the maximum size of a blob to display HTML for in KBytes.
22661 Defaults to @samp{0}.
22665 @deftypevr {@code{cgit-configuration} parameter} string max-stats
22666 Maximum statistics period. Valid values are @samp{week},@samp{month},
22667 @samp{quarter} and @samp{year}.
22669 Defaults to @samp{""}.
22673 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
22674 Mimetype for the specified filename extension.
22676 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
22677 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
22678 "image/png") (svg "image/svg+xml"))}.
22682 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
22683 Specifies the file to use for automatic mimetype lookup.
22685 Defaults to @samp{""}.
22689 @deftypevr {@code{cgit-configuration} parameter} string module-link
22690 Text which will be used as the formatstring for a hyperlink when a
22691 submodule is printed in a directory listing.
22693 Defaults to @samp{""}.
22697 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
22698 If set to the value @samp{#t} caching will be disabled.
22700 Defaults to @samp{#f}.
22704 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
22705 If set to @samp{#t} showing full author email addresses will be
22708 Defaults to @samp{#f}.
22712 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
22713 Flag which, when set to @samp{#t}, will make cgit omit the standard
22714 header on all pages.
22716 Defaults to @samp{#f}.
22720 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
22721 A list of subdirectories inside of @code{repository-directory}, relative
22722 to it, that should loaded as Git repositories. An empty list means that
22723 all subdirectories will be loaded.
22725 Defaults to @samp{()}.
22729 @deftypevr {@code{cgit-configuration} parameter} file-object readme
22730 Text which will be used as default value for @code{cgit-repo-readme}.
22732 Defaults to @samp{""}.
22736 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
22737 If set to @code{#t} and @code{repository-directory} is enabled, if any
22738 repositories are found with a suffix of @code{.git}, this suffix will be
22739 removed for the URL and name.
22741 Defaults to @samp{#f}.
22745 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
22746 Maximum number of files to consider when detecting renames.
22748 Defaults to @samp{-1}.
22752 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
22753 The way in which repositories in each section are sorted.
22755 Defaults to @samp{""}.
22759 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
22760 Text used as content for the @code{robots} meta-tag.
22762 Defaults to @samp{("noindex" "nofollow")}.
22766 @deftypevr {@code{cgit-configuration} parameter} string root-desc
22767 Text printed below the heading on the repository index page.
22769 Defaults to @samp{"a fast webinterface for the git dscm"}.
22773 @deftypevr {@code{cgit-configuration} parameter} string root-readme
22774 The content of the file specified with this option will be included
22775 verbatim below thef "about" link on the repository index page.
22777 Defaults to @samp{""}.
22781 @deftypevr {@code{cgit-configuration} parameter} string root-title
22782 Text printed as heading on the repository index page.
22784 Defaults to @samp{""}.
22788 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
22789 If set to @samp{#t} and repository-directory is enabled,
22790 repository-directory will recurse into directories whose name starts
22791 with a period. Otherwise, repository-directory will stay away from such
22792 directories, considered as "hidden". Note that this does not apply to
22793 the ".git" directory in non-bare repos.
22795 Defaults to @samp{#f}.
22799 @deftypevr {@code{cgit-configuration} parameter} list snapshots
22800 Text which specifies the default set of snapshot formats that cgit
22801 generates links for.
22803 Defaults to @samp{()}.
22807 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
22808 Name of the directory to scan for repositories (represents
22811 Defaults to @samp{"/srv/git"}.
22815 @deftypevr {@code{cgit-configuration} parameter} string section
22816 The name of the current repository section - all repositories defined
22817 after this option will inherit the current section name.
22819 Defaults to @samp{""}.
22823 @deftypevr {@code{cgit-configuration} parameter} string section-sort
22824 Flag which, when set to @samp{1}, will sort the sections on the
22825 repository listing by name.
22827 Defaults to @samp{""}.
22831 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
22832 A number which, if defined prior to repository-directory, specifies how
22833 many path elements from each repo path to use as a default section name.
22835 Defaults to @samp{0}.
22839 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
22840 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
22843 Defaults to @samp{#f}.
22847 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
22848 Specifies a command which will be invoked to format plaintext blobs in
22851 Defaults to @samp{""}.
22855 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
22856 Specifies the number of branches to display in the repository "summary"
22859 Defaults to @samp{10}.
22863 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
22864 Specifies the number of log entries to display in the repository
22867 Defaults to @samp{10}.
22871 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
22872 Specifies the number of tags to display in the repository "summary"
22875 Defaults to @samp{10}.
22879 @deftypevr {@code{cgit-configuration} parameter} string strict-export
22880 Filename which, if specified, needs to be present within the repository
22881 for cgit to allow access to that repository.
22883 Defaults to @samp{""}.
22887 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
22888 URL which, if specified, will be used as root for all cgit links.
22890 Defaults to @samp{"/"}.
22894 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
22895 A list of @dfn{cgit-repo} records to use with config.
22897 Defaults to @samp{()}.
22899 Available @code{repository-cgit-configuration} fields are:
22901 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
22902 A mask of snapshot formats for this repo that cgit generates links for,
22903 restricted by the global @code{snapshots} setting.
22905 Defaults to @samp{()}.
22909 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
22910 Override the default @code{source-filter}.
22912 Defaults to @samp{""}.
22916 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
22917 The relative URL used to access the repository.
22919 Defaults to @samp{""}.
22923 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
22924 Override the default @code{about-filter}.
22926 Defaults to @samp{""}.
22930 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
22931 Flag which, when set to @samp{age}, enables date ordering in the branch
22932 ref list, and when set to @samp{name} enables ordering by branch name.
22934 Defaults to @samp{""}.
22938 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
22939 A list of URLs which can be used to clone repo.
22941 Defaults to @samp{()}.
22945 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
22946 Override the default @code{commit-filter}.
22948 Defaults to @samp{""}.
22952 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
22953 Flag which, when set to @samp{date}, enables strict date ordering in the
22954 commit log, and when set to @samp{topo} enables strict topological
22957 Defaults to @samp{""}.
22961 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
22962 The name of the default branch for this repository. If no such branch
22963 exists in the repository, the first branch name (when sorted) is used as
22964 default instead. By default branch pointed to by HEAD, or "master" if
22965 there is no suitable HEAD.
22967 Defaults to @samp{""}.
22971 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
22972 The value to show as repository description.
22974 Defaults to @samp{""}.
22978 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
22979 The value to show as repository homepage.
22981 Defaults to @samp{""}.
22985 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
22986 Override the default @code{email-filter}.
22988 Defaults to @samp{""}.
22992 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
22993 A flag which can be used to disable the global setting
22994 @code{enable-commit-graph?}.
22996 Defaults to @samp{disabled}.
23000 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
23001 A flag which can be used to disable the global setting
23002 @code{enable-log-filecount?}.
23004 Defaults to @samp{disabled}.
23008 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
23009 A flag which can be used to disable the global setting
23010 @code{enable-log-linecount?}.
23012 Defaults to @samp{disabled}.
23016 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
23017 Flag which, when set to @code{#t}, will make cgit display remote
23018 branches in the summary and refs views.
23020 Defaults to @samp{disabled}.
23024 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
23025 A flag which can be used to override the global setting
23026 @code{enable-subject-links?}.
23028 Defaults to @samp{disabled}.
23032 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
23033 A flag which can be used to override the global setting
23034 @code{enable-html-serving?}.
23036 Defaults to @samp{disabled}.
23040 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
23041 Flag which, when set to @code{#t}, hides the repository from the
23044 Defaults to @samp{#f}.
23048 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
23049 Flag which, when set to @samp{#t}, ignores the repository.
23051 Defaults to @samp{#f}.
23055 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
23056 URL which specifies the source of an image which will be used as a logo
23057 on this repo’s pages.
23059 Defaults to @samp{""}.
23063 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
23064 URL loaded when clicking on the cgit logo image.
23066 Defaults to @samp{""}.
23070 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
23071 Override the default @code{owner-filter}.
23073 Defaults to @samp{""}.
23077 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
23078 Text which will be used as the formatstring for a hyperlink when a
23079 submodule is printed in a directory listing. The arguments for the
23080 formatstring are the path and SHA1 of the submodule commit.
23082 Defaults to @samp{""}.
23086 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
23087 Text which will be used as the formatstring for a hyperlink when a
23088 submodule with the specified subdirectory path is printed in a directory
23091 Defaults to @samp{()}.
23095 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
23096 Override the default maximum statistics period.
23098 Defaults to @samp{""}.
23102 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
23103 The value to show as repository name.
23105 Defaults to @samp{""}.
23109 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
23110 A value used to identify the owner of the repository.
23112 Defaults to @samp{""}.
23116 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
23117 An absolute path to the repository directory.
23119 Defaults to @samp{""}.
23123 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
23124 A path (relative to repo) which specifies a file to include verbatim as
23125 the "About" page for this repo.
23127 Defaults to @samp{""}.
23131 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
23132 The name of the current repository section - all repositories defined
23133 after this option will inherit the current section name.
23135 Defaults to @samp{""}.
23139 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
23140 Extra options will be appended to cgitrc file.
23142 Defaults to @samp{()}.
23148 @deftypevr {@code{cgit-configuration} parameter} list extra-options
23149 Extra options will be appended to cgitrc file.
23151 Defaults to @samp{()}.
23156 @c %end of fragment
23158 However, it could be that you just want to get a @code{cgitrc} up and
23159 running. In that case, you can pass an @code{opaque-cgit-configuration}
23160 as a record to @code{cgit-service-type}. As its name indicates, an
23161 opaque configuration does not have easy reflective capabilities.
23163 Available @code{opaque-cgit-configuration} fields are:
23165 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
23169 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
23170 The contents of the @code{cgitrc}, as a string.
23173 For example, if your @code{cgitrc} is just the empty string, you
23174 could instantiate a cgit service like this:
23177 (service cgit-service-type
23178 (opaque-cgit-configuration
23182 @subsubheading Gitolite Service
23184 @cindex Gitolite service
23185 @cindex Git, hosting
23186 @uref{http://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
23187 repositories on a central server.
23189 Gitolite can handle multiple repositories and users, and supports flexible
23190 configuration of the permissions for the users on the repositories.
23192 The following example will configure Gitolite using the default @code{git}
23193 user, and the provided SSH public key.
23196 (service gitolite-service-type
23197 (gitolite-configuration
23198 (admin-pubkey (plain-file
23200 "ssh-rsa AAAA... guix@@example.com"))))
23203 Gitolite is configured through a special admin repository which you can clone,
23204 for example, if you setup Gitolite on @code{example.com}, you would run the
23205 following command to clone the admin repository.
23208 git clone git@@example.com:gitolite-admin
23211 When the Gitolite service is activated, the provided @code{admin-pubkey} will
23212 be inserted in to the @file{keydir} directory in the gitolite-admin
23213 repository. If this results in a change in the repository, it will be
23214 committed using the message ``gitolite setup by GNU Guix''.
23216 @deftp {Data Type} gitolite-configuration
23217 Data type representing the configuration for @code{gitolite-service-type}.
23220 @item @code{package} (default: @var{gitolite})
23221 Gitolite package to use.
23223 @item @code{user} (default: @var{git})
23224 User to use for Gitolite. This will be user that you use when accessing
23227 @item @code{group} (default: @var{git})
23228 Group to use for Gitolite.
23230 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
23231 Directory in which to store the Gitolite configuration and repositories.
23233 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
23234 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
23235 representing the configuration for Gitolite.
23237 @item @code{admin-pubkey} (default: @var{#f})
23238 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
23239 setup Gitolite. This will be inserted in to the @file{keydir} directory
23240 within the gitolite-admin repository.
23242 To specify the SSH key as a string, use the @code{plain-file} function.
23245 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
23251 @deftp {Data Type} gitolite-rc-file
23252 Data type representing the Gitolite RC file.
23255 @item @code{umask} (default: @code{#o0077})
23256 This controls the permissions Gitolite sets on the repositories and their
23259 A value like @code{#o0027} will give read access to the group used by Gitolite
23260 (by default: @code{git}). This is necessary when using Gitolite with software
23261 like cgit or gitweb.
23263 @item @code{git-config-keys} (default: @code{""})
23264 Gitolite allows you to set git config values using the "config" keyword. This
23265 setting allows control over the config keys to accept.
23267 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
23268 Set the role names allowed to be used by users running the perms command.
23270 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
23271 This setting controls the commands and features to enable within Gitolite.
23277 @node Game Services
23278 @subsection Game Services
23280 @subsubheading The Battle for Wesnoth Service
23282 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
23283 based tactical strategy game, with several single player campaigns, and
23284 multiplayer games (both networked and local).
23286 @defvar {Scheme Variable} wesnothd-service-type
23287 Service type for the wesnothd service. Its value must be a
23288 @code{wesnothd-configuration} object. To run wesnothd in the default
23289 configuration, instantiate it as:
23292 (service wesnothd-service-type)
23296 @deftp {Data Type} wesnothd-configuration
23297 Data type representing the configuration of @command{wesnothd}.
23300 @item @code{package} (default: @code{wesnoth-server})
23301 The wesnoth server package to use.
23303 @item @code{port} (default: @code{15000})
23304 The port to bind the server to.
23308 @node Miscellaneous Services
23309 @subsection Miscellaneous Services
23311 @cindex fingerprint
23312 @subsubheading Fingerprint Service
23314 The @code{(gnu services authentication)} module provides a DBus service to
23315 read and identify fingerprints via a fingerprint sensor.
23317 @defvr {Scheme Variable} fprintd-service-type
23318 The service type for @command{fprintd}, which provides the fingerprint
23319 reading capability.
23322 (service fprintd-service-type)
23327 @subsubheading System Control Service
23329 The @code{(gnu services sysctl)} provides a service to configure kernel
23330 parameters at boot.
23332 @defvr {Scheme Variable} sysctl-service-type
23333 The service type for @command{sysctl}, which modifies kernel parameters
23334 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
23338 (service sysctl-service-type
23339 (sysctl-configuration
23340 (settings '(("net.ipv4.ip_forward" . "1")))))
23344 @deftp {Data Type} sysctl-configuration
23345 The data type representing the configuration of @command{sysctl}.
23348 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
23349 The @command{sysctl} executable to use.
23351 @item @code{settings} (default: @code{'()})
23352 An association list specifies kernel parameters and their values.
23357 @subsubheading PC/SC Smart Card Daemon Service
23359 The @code{(gnu services security-token)} module provides the following service
23360 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
23361 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
23362 manager that coordinates communications with smart card readers, smart cards
23363 and cryptographic tokens that are connected to the system.
23365 @defvr {Scheme Variable} pcscd-service-type
23366 Service type for the @command{pcscd} service. Its value must be a
23367 @code{pcscd-configuration} object. To run pcscd in the default
23368 configuration, instantiate it as:
23371 (service pcscd-service-type)
23375 @deftp {Data Type} pcscd-configuration
23376 The data type representing the configuration of @command{pcscd}.
23379 @item @code{pcsc-lite} (default: @code{pcsc-lite})
23380 The pcsc-lite package that provides pcscd.
23381 @item @code{usb-drivers} (default: @code{(list ccid)})
23382 List of packages that provide USB drivers to pcscd. Drivers are expected to be
23383 under @file{pcsc/drivers} in the store directory of the package.
23388 @subsubheading Lirc Service
23390 The @code{(gnu services lirc)} module provides the following service.
23392 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
23393 [#:device #f] [#:driver #f] [#:config-file #f] @
23394 [#:extra-options '()]
23395 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
23396 decodes infrared signals from remote controls.
23398 Optionally, @var{device}, @var{driver} and @var{config-file}
23399 (configuration file name) may be specified. See @command{lircd} manual
23402 Finally, @var{extra-options} is a list of additional command-line options
23403 passed to @command{lircd}.
23407 @subsubheading Spice Service
23409 The @code{(gnu services spice)} module provides the following service.
23411 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
23412 Returns a service that runs @url{http://www.spice-space.org,VDAGENT}, a daemon
23413 that enables sharing the clipboard with a vm and setting the guest display
23414 resolution when the graphical console window resizes.
23417 @cindex inputattach
23418 @subsubheading inputattach Service
23420 @cindex tablet input, for Xorg
23421 @cindex touchscreen input, for Xorg
23422 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
23423 use input devices such as Wacom tablets, touchscreens, or joysticks with the
23424 Xorg display server.
23426 @deffn {Scheme Variable} inputattach-service-type
23427 Type of a service that runs @command{inputattach} on a device and
23428 dispatches events from it.
23431 @deftp {Data Type} inputattach-configuration
23433 @item @code{device-type} (default: @code{"wacom"})
23434 The type of device to connect to. Run @command{inputattach --help}, from the
23435 @code{inputattach} package, to see the list of supported device types.
23437 @item @code{device} (default: @code{"/dev/ttyS0"})
23438 The device file to connect to the device.
23440 @item @code{log-file} (default: @code{#f})
23441 If true, this must be the name of a file to log messages to.
23445 @subsection Dictionary Services
23447 The @code{(gnu services dict)} module provides the following service:
23449 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
23450 Return a service that runs the @command{dicod} daemon, an implementation
23451 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
23453 The optional @var{config} argument specifies the configuration for
23454 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
23455 default it serves the GNU Collaborative International Dictonary of English.
23457 You can add @command{open localhost} to your @file{~/.dico} file to make
23458 @code{localhost} the default server for @command{dico} client
23459 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
23462 @deftp {Data Type} dicod-configuration
23463 Data type representing the configuration of dicod.
23466 @item @code{dico} (default: @var{dico})
23467 Package object of the GNU Dico dictionary server.
23469 @item @code{interfaces} (default: @var{'("localhost")})
23470 This is the list of IP addresses and ports and possibly socket file
23471 names to listen to (@pxref{Server Settings, @code{listen} directive,,
23472 dico, GNU Dico Manual}).
23474 @item @code{handlers} (default: @var{'()})
23475 List of @code{<dicod-handler>} objects denoting handlers (module instances).
23477 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
23478 List of @code{<dicod-database>} objects denoting dictionaries to be served.
23482 @deftp {Data Type} dicod-handler
23483 Data type representing a dictionary handler (module instance).
23487 Name of the handler (module instance).
23489 @item @code{module} (default: @var{#f})
23490 Name of the dicod module of the handler (instance). If it is @code{#f},
23491 the module has the same name as the handler.
23492 (@pxref{Modules,,, dico, GNU Dico Manual}).
23494 @item @code{options}
23495 List of strings or gexps representing the arguments for the module handler
23499 @deftp {Data Type} dicod-database
23500 Data type representing a dictionary database.
23504 Name of the database, will be used in DICT commands.
23506 @item @code{handler}
23507 Name of the dicod handler (module instance) used by this database
23508 (@pxref{Handlers,,, dico, GNU Dico Manual}).
23510 @item @code{complex?} (default: @var{#f})
23511 Whether the database configuration complex. The complex configuration
23512 will need a corresponding @code{<dicod-handler>} object, otherwise not.
23514 @item @code{options}
23515 List of strings or gexps representing the arguments for the database
23516 (@pxref{Databases,,, dico, GNU Dico Manual}).
23520 @defvr {Scheme Variable} %dicod-database:gcide
23521 A @code{<dicod-database>} object serving the GNU Collaborative International
23522 Dictionary of English using the @code{gcide} package.
23525 The following is an example @code{dicod-service} configuration.
23528 (dicod-service #:config
23529 (dicod-configuration
23530 (handlers (list (dicod-handler
23534 (list #~(string-append "dbdir=" #$wordnet))))))
23535 (databases (list (dicod-database
23538 (handler "wordnet")
23539 (options '("database=wn")))
23540 %dicod-database:gcide))))
23544 @subsubheading Docker Service
23546 The @code{(gnu services docker)} module provides the following service.
23548 @defvr {Scheme Variable} docker-service-type
23550 This is the type of the service that runs @url{http://www.docker.com,Docker},
23551 a daemon that can execute application bundles (sometimes referred to as
23552 ``containers'') in isolated environments.
23556 @deftp {Data Type} docker-configuration
23557 This is the data type representing the configuration of Docker and Containerd.
23561 @item @code{package} (default: @code{docker})
23562 The Docker package to use.
23564 @item @code{containerd} (default: @var{containerd})
23565 The Containerd package to use.
23570 @node Setuid Programs
23571 @section Setuid Programs
23573 @cindex setuid programs
23574 Some programs need to run with ``root'' privileges, even when they are
23575 launched by unprivileged users. A notorious example is the
23576 @command{passwd} program, which users can run to change their
23577 password, and which needs to access the @file{/etc/passwd} and
23578 @file{/etc/shadow} files---something normally restricted to root, for
23579 obvious security reasons. To address that, these executables are
23580 @dfn{setuid-root}, meaning that they always run with root privileges
23581 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
23582 for more info about the setuid mechanism.)
23584 The store itself @emph{cannot} contain setuid programs: that would be a
23585 security issue since any user on the system can write derivations that
23586 populate the store (@pxref{The Store}). Thus, a different mechanism is
23587 used: instead of changing the setuid bit directly on files that are in
23588 the store, we let the system administrator @emph{declare} which programs
23589 should be setuid root.
23591 The @code{setuid-programs} field of an @code{operating-system}
23592 declaration contains a list of G-expressions denoting the names of
23593 programs to be setuid-root (@pxref{Using the Configuration System}).
23594 For instance, the @command{passwd} program, which is part of the Shadow
23595 package, can be designated by this G-expression (@pxref{G-Expressions}):
23598 #~(string-append #$shadow "/bin/passwd")
23601 A default set of setuid programs is defined by the
23602 @code{%setuid-programs} variable of the @code{(gnu system)} module.
23604 @defvr {Scheme Variable} %setuid-programs
23605 A list of G-expressions denoting common programs that are setuid-root.
23607 The list includes commands such as @command{passwd}, @command{ping},
23608 @command{su}, and @command{sudo}.
23611 Under the hood, the actual setuid programs are created in the
23612 @file{/run/setuid-programs} directory at system activation time. The
23613 files in this directory refer to the ``real'' binaries, which are in the
23616 @node X.509 Certificates
23617 @section X.509 Certificates
23619 @cindex HTTPS, certificates
23620 @cindex X.509 certificates
23622 Web servers available over HTTPS (that is, HTTP over the transport-layer
23623 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
23624 that the client can then use to @emph{authenticate} the server. To do
23625 that, clients verify that the server's certificate is signed by a
23626 so-called @dfn{certificate authority} (CA). But to verify the CA's
23627 signature, clients must have first acquired the CA's certificate.
23629 Web browsers such as GNU@tie{}IceCat include their own set of CA
23630 certificates, such that they are able to verify CA signatures
23633 However, most other programs that can talk HTTPS---@command{wget},
23634 @command{git}, @command{w3m}, etc.---need to be told where CA
23635 certificates can be found.
23637 @cindex @code{nss-certs}
23638 In Guix, this is done by adding a package that provides certificates
23639 to the @code{packages} field of the @code{operating-system} declaration
23640 (@pxref{operating-system Reference}). Guix includes one such package,
23641 @code{nss-certs}, which is a set of CA certificates provided as part of
23642 Mozilla's Network Security Services.
23644 Note that it is @emph{not} part of @var{%base-packages}, so you need to
23645 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
23646 most applications and libraries look for certificates by default, points
23647 to the certificates installed globally.
23649 Unprivileged users, including users of Guix on a foreign distro,
23650 can also install their own certificate package in
23651 their profile. A number of environment variables need to be defined so
23652 that applications and libraries know where to find them. Namely, the
23653 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
23654 variables. Some applications add their own environment variables; for
23655 instance, the Git version control system honors the certificate bundle
23656 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
23657 would typically run something like:
23660 $ guix install nss-certs
23661 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
23662 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
23663 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
23666 As another example, R requires the @code{CURL_CA_BUNDLE} environment
23667 variable to point to a certificate bundle, so you would have to run
23668 something like this:
23671 $ guix install nss-certs
23672 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
23675 For other applications you may want to look up the required environment
23676 variable in the relevant documentation.
23679 @node Name Service Switch
23680 @section Name Service Switch
23682 @cindex name service switch
23684 The @code{(gnu system nss)} module provides bindings to the
23685 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
23686 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
23687 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
23688 extended with new ``name'' lookup methods for system databases, which
23689 includes host names, service names, user accounts, and more (@pxref{Name
23690 Service Switch, System Databases and Name Service Switch,, libc, The GNU
23691 C Library Reference Manual}).
23693 The NSS configuration specifies, for each system database, which lookup
23694 method is to be used, and how the various methods are chained
23695 together---for instance, under which circumstances NSS should try the
23696 next method in the list. The NSS configuration is given in the
23697 @code{name-service-switch} field of @code{operating-system} declarations
23698 (@pxref{operating-system Reference, @code{name-service-switch}}).
23701 @cindex .local, host name lookup
23702 As an example, the declaration below configures the NSS to use the
23703 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
23704 back-end}, which supports host name lookups over multicast DNS (mDNS)
23705 for host names ending in @code{.local}:
23708 (name-service-switch
23709 (hosts (list %files ;first, check /etc/hosts
23711 ;; If the above did not succeed, try
23712 ;; with 'mdns_minimal'.
23714 (name "mdns_minimal")
23716 ;; 'mdns_minimal' is authoritative for
23717 ;; '.local'. When it returns "not found",
23718 ;; no need to try the next methods.
23719 (reaction (lookup-specification
23720 (not-found => return))))
23722 ;; Then fall back to DNS.
23726 ;; Finally, try with the "full" 'mdns'.
23731 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
23732 contains this configuration, so you will not have to type it if all you
23733 want is to have @code{.local} host lookup working.
23735 Note that, in this case, in addition to setting the
23736 @code{name-service-switch} of the @code{operating-system} declaration,
23737 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
23738 @code{avahi-service-type}}), or @var{%desktop-services}, which includes it
23739 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
23740 to the name service cache daemon (@pxref{Base Services,
23741 @code{nscd-service}}).
23743 For convenience, the following variables provide typical NSS
23746 @defvr {Scheme Variable} %default-nss
23747 This is the default name service switch configuration, a
23748 @code{name-service-switch} object.
23751 @defvr {Scheme Variable} %mdns-host-lookup-nss
23752 This is the name service switch configuration with support for host name
23753 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
23756 The reference for name service switch configuration is given below. It
23757 is a direct mapping of the configuration file format of the C library , so
23758 please refer to the C library manual for more information (@pxref{NSS
23759 Configuration File,,, libc, The GNU C Library Reference Manual}).
23760 Compared to the configuration file format of libc NSS, it has the advantage
23761 not only of adding this warm parenthetic feel that we like, but also
23762 static checks: you will know about syntax errors and typos as soon as you
23763 run @command{guix system}.
23765 @deftp {Data Type} name-service-switch
23767 This is the data type representation the configuration of libc's name
23768 service switch (NSS). Each field below represents one of the supported
23785 The system databases handled by the NSS. Each of these fields must be a
23786 list of @code{<name-service>} objects (see below).
23790 @deftp {Data Type} name-service
23792 This is the data type representing an actual name service and the
23793 associated lookup action.
23797 A string denoting the name service (@pxref{Services in the NSS
23798 configuration,,, libc, The GNU C Library Reference Manual}).
23800 Note that name services listed here must be visible to nscd. This is
23801 achieved by passing the @code{#:name-services} argument to
23802 @code{nscd-service} the list of packages providing the needed name
23803 services (@pxref{Base Services, @code{nscd-service}}).
23806 An action specified using the @code{lookup-specification} macro
23807 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
23808 Reference Manual}). For example:
23811 (lookup-specification (unavailable => continue)
23812 (success => return))
23817 @node Initial RAM Disk
23818 @section Initial RAM Disk
23821 @cindex initial RAM disk
23822 For bootstrapping purposes, the Linux-Libre kernel is passed an
23823 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
23824 root file system as well as an initialization script. The latter is
23825 responsible for mounting the real root file system, and for loading any
23826 kernel modules that may be needed to achieve that.
23828 The @code{initrd-modules} field of an @code{operating-system}
23829 declaration allows you to specify Linux-libre kernel modules that must
23830 be available in the initrd. In particular, this is where you would list
23831 modules needed to actually drive the hard disk where your root partition
23832 is---although the default value of @code{initrd-modules} should cover
23833 most use cases. For example, assuming you need the @code{megaraid_sas}
23834 module in addition to the default modules to be able to access your root
23835 file system, you would write:
23840 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
23843 @defvr {Scheme Variable} %base-initrd-modules
23844 This is the list of kernel modules included in the initrd by default.
23847 Furthermore, if you need lower-level customization, the @code{initrd}
23848 field of an @code{operating-system} declaration allows
23849 you to specify which initrd you would like to use. The @code{(gnu
23850 system linux-initrd)} module provides three ways to build an initrd: the
23851 high-level @code{base-initrd} procedure and the low-level
23852 @code{raw-initrd} and @code{expression->initrd} procedures.
23854 The @code{base-initrd} procedure is intended to cover most common uses.
23855 For example, if you want to add a bunch of kernel modules to be loaded
23856 at boot time, you can define the @code{initrd} field of the operating
23857 system declaration like this:
23860 (initrd (lambda (file-systems . rest)
23861 ;; Create a standard initrd but set up networking
23862 ;; with the parameters QEMU expects by default.
23863 (apply base-initrd file-systems
23864 #:qemu-networking? #t
23868 The @code{base-initrd} procedure also handles common use cases that
23869 involves using the system as a QEMU guest, or as a ``live'' system with
23870 volatile root file system.
23872 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
23873 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
23874 such as trying to guess which kernel modules and packages should be included
23875 to the initrd. An example use of @code{raw-initrd} is when a user has
23876 a custom Linux kernel configuration and default kernel modules included by
23877 @code{base-initrd} are not available.
23879 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
23880 honors several options passed on the Linux kernel command line
23881 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
23882 @code{-append} option of QEMU), notably:
23885 @item --load=@var{boot}
23886 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
23887 program, once it has mounted the root file system.
23889 Guix uses this option to yield control to a boot program that runs the
23890 service activation programs and then spawns the GNU@tie{}Shepherd, the
23891 initialization system.
23893 @item --root=@var{root}
23894 Mount @var{root} as the root file system. @var{root} can be a
23895 device name like @code{/dev/sda1}, a file system label, or a file system
23898 @item --system=@var{system}
23899 Have @file{/run/booted-system} and @file{/run/current-system} point to
23902 @item modprobe.blacklist=@var{modules}@dots{}
23903 @cindex module, black-listing
23904 @cindex black list, of kernel modules
23905 Instruct the initial RAM disk as well as the @command{modprobe} command
23906 (from the kmod package) to refuse to load @var{modules}. @var{modules}
23907 must be a comma-separated list of module names---e.g.,
23908 @code{usbkbd,9pnet}.
23911 Start a read-eval-print loop (REPL) from the initial RAM disk before it
23912 tries to load kernel modules and to mount the root file system. Our
23913 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
23914 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
23915 Manual}, for more information on Guile's REPL.
23919 Now that you know all the features that initial RAM disks produced by
23920 @code{base-initrd} and @code{raw-initrd} provide,
23921 here is how to use it and customize it further.
23924 @cindex initial RAM disk
23925 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
23926 [#:linux-modules '()] [#:mapped-devices '()] @
23927 [#:keyboard-layout #f] @
23928 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
23929 Return a derivation that builds a raw initrd. @var{file-systems} is
23930 a list of file systems to be mounted by the initrd, possibly in addition to
23931 the root file system specified on the kernel command line via @code{--root}.
23932 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
23933 @var{mapped-devices} is a list of device mappings to realize before
23934 @var{file-systems} are mounted (@pxref{Mapped Devices}).
23935 @var{helper-packages} is a list of packages to be copied in the initrd. It may
23936 include @code{e2fsck/static} or other packages needed by the initrd to check
23937 the root file system.
23939 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
23940 the desired console keyboard layout. This is done before @var{mapped-devices}
23941 are set up and before @var{file-systems} are mounted such that, should the
23942 user need to enter a passphrase or use the REPL, this happens using the
23943 intended keyboard layout.
23945 When @var{qemu-networking?} is true, set up networking with the standard QEMU
23946 parameters. When @var{virtio?} is true, load additional modules so that the
23947 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
23949 When @var{volatile-root?} is true, the root file system is writable but any changes
23953 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
23954 [#:mapped-devices '()] [#:keyboard-layout #f] @
23955 [#:qemu-networking? #f] [#:volatile-root? #f] @
23956 [#:linux-modules '()]
23957 Return as a file-like object a generic initrd, with kernel
23958 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
23959 mounted by the initrd, possibly in addition to the root file system specified
23960 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
23961 mappings to realize before @var{file-systems} are mounted.
23963 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
23964 the desired console keyboard layout. This is done before @var{mapped-devices}
23965 are set up and before @var{file-systems} are mounted such that, should the
23966 user need to enter a passphrase or use the REPL, this happens using the
23967 intended keyboard layout.
23969 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
23971 The initrd is automatically populated with all the kernel modules necessary
23972 for @var{file-systems} and for the given options. Additional kernel
23973 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
23974 loaded at boot time in the order in which they appear.
23977 Needless to say, the initrds we produce and use embed a
23978 statically-linked Guile, and the initialization program is a Guile
23979 program. That gives a lot of flexibility. The
23980 @code{expression->initrd} procedure builds such an initrd, given the
23981 program to run in that initrd.
23983 @deffn {Scheme Procedure} expression->initrd @var{exp} @
23984 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
23985 Return as a file-like object a Linux initrd (a gzipped cpio archive)
23986 containing @var{guile} and that evaluates @var{exp}, a G-expression,
23987 upon booting. All the derivations referenced by @var{exp} are
23988 automatically copied to the initrd.
23991 @node Bootloader Configuration
23992 @section Bootloader Configuration
23995 @cindex boot loader
23997 The operating system supports multiple bootloaders. The bootloader is
23998 configured using @code{bootloader-configuration} declaration. All the
23999 fields of this structure are bootloader agnostic except for one field,
24000 @code{bootloader} that indicates the bootloader to be configured and
24003 Some of the bootloaders do not honor every field of
24004 @code{bootloader-configuration}. For instance, the extlinux
24005 bootloader does not support themes and thus ignores the @code{theme}
24008 @deftp {Data Type} bootloader-configuration
24009 The type of a bootloader configuration declaration.
24013 @item @code{bootloader}
24014 @cindex EFI, bootloader
24015 @cindex UEFI, bootloader
24016 @cindex BIOS, bootloader
24017 The bootloader to use, as a @code{bootloader} object. For now
24018 @code{grub-bootloader}, @code{grub-efi-bootloader},
24019 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
24021 @vindex grub-efi-bootloader
24022 @code{grub-efi-bootloader} allows to boot on modern systems using the
24023 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
24024 use if the installation image contains a @file{/sys/firmware/efi} directory
24025 when you boot it on your system.
24027 @vindex grub-bootloader
24028 @code{grub-bootloader} allows you to boot in particular Intel-based machines
24029 in ``legacy'' BIOS mode.
24031 @cindex ARM, bootloaders
24032 @cindex AArch64, bootloaders
24033 Available bootloaders are described in @code{(gnu bootloader @dots{})}
24034 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
24035 of bootloaders for a wide range of ARM and AArch64 systems, using the
24036 @uref{http://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
24038 @item @code{target}
24039 This is a string denoting the target onto which to install the
24042 The interpretation depends on the bootloader in question. For
24043 @code{grub-bootloader}, for example, it should be a device name understood by
24044 the bootloader @command{installer} command, such as @code{/dev/sda} or
24045 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
24046 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
24047 system, usually @file{/boot/efi}.
24049 @item @code{menu-entries} (default: @code{()})
24050 A possibly empty list of @code{menu-entry} objects (see below), denoting
24051 entries to appear in the bootloader menu, in addition to the current
24052 system entry and the entry pointing to previous system generations.
24054 @item @code{default-entry} (default: @code{0})
24055 The index of the default boot menu entry. Index 0 is for the entry of the
24058 @item @code{timeout} (default: @code{5})
24059 The number of seconds to wait for keyboard input before booting. Set to
24060 0 to boot immediately, and to -1 to wait indefinitely.
24062 @cindex keyboard layout, for the bootloader
24063 @item @code{keyboard-layout} (default: @code{#f})
24064 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
24065 layout, usually US@tie{}English (``qwerty'').
24067 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
24071 This option is currently ignored by bootloaders other than @code{grub} and
24075 @item @code{theme} (default: @var{#f})
24076 The bootloader theme object describing the theme to use. If no theme
24077 is provided, some bootloaders might use a default theme, that's true
24080 @item @code{terminal-outputs} (default: @code{'gfxterm})
24081 The output terminals used for the bootloader boot menu, as a list of
24082 symbols. GRUB accepts the values: @code{console}, @code{serial},
24083 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
24084 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
24085 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
24086 configuration,,, grub,GNU GRUB manual}).
24088 @item @code{terminal-inputs} (default: @code{'()})
24089 The input terminals used for the bootloader boot menu, as a list of
24090 symbols. For GRUB, the default is the native platform terminal as
24091 determined at run-time. GRUB accepts the values: @code{console},
24092 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
24093 @code{usb_keyboard}. This field corresponds to the GRUB variable
24094 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
24097 @item @code{serial-unit} (default: @code{#f})
24098 The serial unit used by the bootloader, as an integer from 0 to 3.
24099 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
24100 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
24102 @item @code{serial-speed} (default: @code{#f})
24103 The speed of the serial interface, as an integer. For GRUB, the
24104 default value is chosen at run-time; currently GRUB chooses
24105 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
24112 Should you want to list additional boot menu entries @i{via} the
24113 @code{menu-entries} field above, you will need to create them with the
24114 @code{menu-entry} form. For example, imagine you want to be able to
24115 boot another distro (hard to imagine!), you can define a menu entry
24120 (label "The Other Distro")
24121 (linux "/boot/old/vmlinux-2.6.32")
24122 (linux-arguments '("root=/dev/sda2"))
24123 (initrd "/boot/old/initrd"))
24128 @deftp {Data Type} menu-entry
24129 The type of an entry in the bootloader menu.
24134 The label to show in the menu---e.g., @code{"GNU"}.
24137 The Linux kernel image to boot, for example:
24140 (file-append linux-libre "/bzImage")
24143 For GRUB, it is also possible to specify a device explicitly in the
24144 file path using GRUB's device naming convention (@pxref{Naming
24145 convention,,, grub, GNU GRUB manual}), for example:
24148 "(hd0,msdos1)/boot/vmlinuz"
24151 If the device is specified explicitly as above, then the @code{device}
24152 field is ignored entirely.
24154 @item @code{linux-arguments} (default: @code{()})
24155 The list of extra Linux kernel command-line arguments---e.g.,
24156 @code{("console=ttyS0")}.
24158 @item @code{initrd}
24159 A G-Expression or string denoting the file name of the initial RAM disk
24160 to use (@pxref{G-Expressions}).
24161 @item @code{device} (default: @code{#f})
24162 The device where the kernel and initrd are to be found---i.e., for GRUB,
24163 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
24165 This may be a file system label (a string), a file system UUID (a
24166 bytevector, @pxref{File Systems}), or @code{#f}, in which case
24167 the bootloader will search the device containing the file specified by
24168 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
24169 must @emph{not} be an OS device name such as @file{/dev/sda1}.
24174 @c FIXME: Write documentation once it's stable.
24175 For now only GRUB has theme support. GRUB themes are created using
24176 the @code{grub-theme} form, which is not documented yet.
24178 @defvr {Scheme Variable} %default-theme
24179 This is the default GRUB theme used by the operating system if no
24180 @code{theme} field is specified in @code{bootloader-configuration}
24183 It comes with a fancy background image displaying the GNU and Guix
24188 @node Invoking guix system
24189 @section Invoking @code{guix system}
24191 Once you have written an operating system declaration as seen in the
24192 previous section, it can be @dfn{instantiated} using the @command{guix
24193 system} command. The synopsis is:
24196 guix system @var{options}@dots{} @var{action} @var{file}
24199 @var{file} must be the name of a file containing an
24200 @code{operating-system} declaration. @var{action} specifies how the
24201 operating system is instantiated. Currently the following values are
24206 Display available service type definitions that match the given regular
24207 expressions, sorted by relevance:
24210 $ guix system search console font
24211 name: console-fonts
24212 location: gnu/services/base.scm:729:2
24213 extends: shepherd-root
24214 description: Install the given fonts on the specified ttys (fonts are
24215 + per virtual console on GNU/Linux). The value of this service is a list
24216 + of tty/font pairs like:
24218 + '(("tty1" . "LatGrkCyr-8x16"))
24222 location: gnu/services/base.scm:1048:2
24223 extends: shepherd-root
24224 description: Provide console login using the `mingetty' program.
24228 location: gnu/services/base.scm:775:2
24230 description: Provide a console log-in service as specified by its
24231 + configuration value, a `login-configuration' object.
24237 As for @command{guix package --search}, the result is written in
24238 @code{recutils} format, which makes it easy to filter the output
24239 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
24242 Build the operating system described in @var{file}, activate it, and
24243 switch to it@footnote{This action (and the related actions
24244 @code{switch-generation} and @code{roll-back}) are usable only on
24245 systems already running Guix System.}.
24247 This effects all the configuration specified in @var{file}: user
24248 accounts, system services, global package list, setuid programs, etc.
24249 The command starts system services specified in @var{file} that are not
24250 currently running; if a service is currently running this command will
24251 arrange for it to be upgraded the next time it is stopped (e.g.@: by
24252 @code{herd stop X} or @code{herd restart X}).
24254 This command creates a new generation whose number is one greater than
24255 the current generation (as reported by @command{guix system
24256 list-generations}). If that generation already exists, it will be
24257 overwritten. This behavior mirrors that of @command{guix package}
24258 (@pxref{Invoking guix package}).
24260 It also adds a bootloader menu entry for the new OS configuration,
24261 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
24262 entries for older configurations to a submenu, allowing you to choose
24263 an older system generation at boot time should you need it.
24266 @c The paragraph below refers to the problem discussed at
24267 @c <http://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
24268 It is highly recommended to run @command{guix pull} once before you run
24269 @command{guix system reconfigure} for the first time (@pxref{Invoking
24270 guix pull}). Failing to do that you would see an older version of Guix
24271 once @command{reconfigure} has completed.
24274 @item switch-generation
24275 @cindex generations
24276 Switch to an existing system generation. This action atomically
24277 switches the system profile to the specified system generation. It
24278 also rearranges the system's existing bootloader menu entries. It
24279 makes the menu entry for the specified system generation the default,
24280 and it moves the entries for the other generatiors to a submenu, if
24281 supported by the bootloader being used. The next time the system
24282 boots, it will use the specified system generation.
24284 The bootloader itself is not being reinstalled when using this
24285 command. Thus, the installed bootloader is used with an updated
24286 configuration file.
24288 The target generation can be specified explicitly by its generation
24289 number. For example, the following invocation would switch to system
24293 guix system switch-generation 7
24296 The target generation can also be specified relative to the current
24297 generation with the form @code{+N} or @code{-N}, where @code{+3} means
24298 ``3 generations ahead of the current generation,'' and @code{-1} means
24299 ``1 generation prior to the current generation.'' When specifying a
24300 negative value such as @code{-1}, you must precede it with @code{--} to
24301 prevent it from being parsed as an option. For example:
24304 guix system switch-generation -- -1
24307 Currently, the effect of invoking this action is @emph{only} to switch
24308 the system profile to an existing generation and rearrange the
24309 bootloader menu entries. To actually start using the target system
24310 generation, you must reboot after running this action. In the future,
24311 it will be updated to do the same things as @command{reconfigure},
24312 like activating and deactivating services.
24314 This action will fail if the specified generation does not exist.
24317 @cindex rolling back
24318 Switch to the preceding system generation. The next time the system
24319 boots, it will use the preceding system generation. This is the inverse
24320 of @command{reconfigure}, and it is exactly the same as invoking
24321 @command{switch-generation} with an argument of @code{-1}.
24323 Currently, as with @command{switch-generation}, you must reboot after
24324 running this action to actually start using the preceding system
24327 @item delete-generations
24328 @cindex deleting system generations
24329 @cindex saving space
24330 Delete system generations, making them candidates for garbage collection
24331 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
24334 This works in the same way as @command{guix package --delete-generations}
24335 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
24336 arguments, all system generations but the current one are deleted:
24339 guix system delete-generations
24342 You can also select the generations you want to delete. The example below
24343 deletes all the system generations that are more than two month old:
24346 guix system delete-generations 2m
24349 Running this command automatically reinstalls the bootloader with an updated
24350 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
24351 longer lists the generations that have been deleted.
24354 Build the derivation of the operating system, which includes all the
24355 configuration files and programs needed to boot and run the system.
24356 This action does not actually install anything.
24359 Populate the given directory with all the files necessary to run the
24360 operating system specified in @var{file}. This is useful for first-time
24361 installations of Guix System. For instance:
24364 guix system init my-os-config.scm /mnt
24367 copies to @file{/mnt} all the store items required by the configuration
24368 specified in @file{my-os-config.scm}. This includes configuration
24369 files, packages, and so on. It also creates other essential files
24370 needed for the system to operate correctly---e.g., the @file{/etc},
24371 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
24373 This command also installs bootloader on the target specified in
24374 @file{my-os-config}, unless the @option{--no-bootloader} option was
24378 @cindex virtual machine
24380 @anchor{guix system vm}
24381 Build a virtual machine that contains the operating system declared in
24382 @var{file}, and return a script to run that virtual machine (VM).
24385 The @code{vm} action and others below
24386 can use KVM support in the Linux-libre kernel. Specifically, if the
24387 machine has hardware virtualization support, the corresponding
24388 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
24389 must exist and be readable and writable by the user and by the
24390 build users of the daemon (@pxref{Build Environment Setup}).
24393 Arguments given to the script are passed to QEMU as in the example
24394 below, which enables networking and requests 1@tie{}GiB of RAM for the
24398 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
24401 The VM shares its store with the host system.
24403 Additional file systems can be shared between the host and the VM using
24404 the @code{--share} and @code{--expose} command-line options: the former
24405 specifies a directory to be shared with write access, while the latter
24406 provides read-only access to the shared directory.
24408 The example below creates a VM in which the user's home directory is
24409 accessible read-only, and where the @file{/exchange} directory is a
24410 read-write mapping of @file{$HOME/tmp} on the host:
24413 guix system vm my-config.scm \
24414 --expose=$HOME --share=$HOME/tmp=/exchange
24417 On GNU/Linux, the default is to boot directly to the kernel; this has
24418 the advantage of requiring only a very tiny root disk image since the
24419 store of the host can then be mounted.
24421 The @code{--full-boot} option forces a complete boot sequence, starting
24422 with the bootloader. This requires more disk space since a root image
24423 containing at least the kernel, initrd, and bootloader data files must
24424 be created. The @code{--image-size} option can be used to specify the
24427 @cindex System images, creation in various formats
24428 @cindex Creating system images in various formats
24431 @itemx docker-image
24432 Return a virtual machine, disk image, or Docker image of the operating
24433 system declared in @var{file} that stands alone. By default,
24434 @command{guix system} estimates the size of the image needed to store
24435 the system, but you can use the @option{--image-size} option to specify
24436 a value. Docker images are built to contain exactly what they need, so
24437 the @option{--image-size} option is ignored in the case of
24438 @code{docker-image}.
24440 You can specify the root file system type by using the
24441 @option{--file-system-type} option. It defaults to @code{ext4}.
24443 When using @code{vm-image}, the returned image is in qcow2 format, which
24444 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
24445 for more information on how to run the image in a virtual machine.
24447 When using @code{disk-image}, a raw disk image is produced; it can be
24448 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
24449 the device corresponding to a USB stick, one can copy the image to it
24450 using the following command:
24453 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
24456 When using @code{docker-image}, a Docker image is produced. Guix builds
24457 the image from scratch, not from a pre-existing Docker base image. As a
24458 result, it contains @emph{exactly} what you define in the operating
24459 system configuration file. You can then load the image and launch a
24460 Docker container using commands like the following:
24463 image_id="$(docker load < guix-system-docker-image.tar.gz)"
24464 docker run -e GUIX_NEW_SYSTEM=/var/guix/profiles/system \\
24465 --entrypoint /var/guix/profiles/system/profile/bin/guile \\
24466 $image_id /var/guix/profiles/system/boot
24469 This command starts a new Docker container from the specified image. It
24470 will boot the Guix system in the usual manner, which means it will
24471 start any services you have defined in the operating system
24472 configuration. Depending on what you run in the Docker container, it
24473 may be necessary to give the container additional permissions. For
24474 example, if you intend to build software using Guix inside of the Docker
24475 container, you may need to pass the @option{--privileged} option to
24479 Return a script to run the operating system declared in @var{file}
24480 within a container. Containers are a set of lightweight isolation
24481 mechanisms provided by the kernel Linux-libre. Containers are
24482 substantially less resource-demanding than full virtual machines since
24483 the kernel, shared objects, and other resources can be shared with the
24484 host system; this also means they provide thinner isolation.
24486 Currently, the script must be run as root in order to support more than
24487 a single user and group. The container shares its store with the host
24490 As with the @code{vm} action (@pxref{guix system vm}), additional file
24491 systems to be shared between the host and container can be specified
24492 using the @option{--share} and @option{--expose} options:
24495 guix system container my-config.scm \
24496 --expose=$HOME --share=$HOME/tmp=/exchange
24500 This option requires Linux-libre 3.19 or newer.
24505 @var{options} can contain any of the common build options (@pxref{Common
24506 Build Options}). In addition, @var{options} can contain one of the
24510 @item --expression=@var{expr}
24511 @itemx -e @var{expr}
24512 Consider the operating-system @var{expr} evaluates to.
24513 This is an alternative to specifying a file which evaluates to an
24515 This is used to generate the Guix system installer @pxref{Building the
24516 Installation Image}).
24518 @item --system=@var{system}
24519 @itemx -s @var{system}
24520 Attempt to build for @var{system} instead of the host system type.
24521 This works as per @command{guix build} (@pxref{Invoking guix build}).
24525 Return the derivation file name of the given operating system without
24528 @item --file-system-type=@var{type}
24529 @itemx -t @var{type}
24530 For the @code{disk-image} action, create a file system of the given
24531 @var{type} on the image.
24533 When this option is omitted, @command{guix system} uses @code{ext4}.
24535 @cindex ISO-9660 format
24536 @cindex CD image format
24537 @cindex DVD image format
24538 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
24539 for burning on CDs and DVDs.
24541 @item --image-size=@var{size}
24542 For the @code{vm-image} and @code{disk-image} actions, create an image
24543 of the given @var{size}. @var{size} may be a number of bytes, or it may
24544 include a unit as a suffix (@pxref{Block size, size specifications,,
24545 coreutils, GNU Coreutils}).
24547 When this option is omitted, @command{guix system} computes an estimate
24548 of the image size as a function of the size of the system declared in
24551 @item --root=@var{file}
24552 @itemx -r @var{file}
24553 Make @var{file} a symlink to the result, and register it as a garbage
24556 @item --skip-checks
24557 Skip pre-installation safety checks.
24559 By default, @command{guix system init} and @command{guix system
24560 reconfigure} perform safety checks: they make sure the file systems that
24561 appear in the @code{operating-system} declaration actually exist
24562 (@pxref{File Systems}), and that any Linux kernel modules that may be
24563 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
24564 RAM Disk}). Passing this option skips these tests altogether.
24567 @cindex on-error strategy
24568 @cindex error strategy
24569 @item --on-error=@var{strategy}
24570 Apply @var{strategy} when an error occurs when reading @var{file}.
24571 @var{strategy} may be one of the following:
24574 @item nothing-special
24575 Report the error concisely and exit. This is the default strategy.
24578 Likewise, but also display a backtrace.
24581 Report the error and enter Guile's debugger. From there, you can run
24582 commands such as @code{,bt} to get a backtrace, @code{,locals} to
24583 display local variable values, and more generally inspect the state of the
24584 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
24585 a list of available debugging commands.
24589 Once you have built, configured, re-configured, and re-re-configured
24590 your Guix installation, you may find it useful to list the operating
24591 system generations available on disk---and that you can choose from the
24592 bootloader boot menu:
24596 @item list-generations
24597 List a summary of each generation of the operating system available on
24598 disk, in a human-readable way. This is similar to the
24599 @option{--list-generations} option of @command{guix package}
24600 (@pxref{Invoking guix package}).
24602 Optionally, one can specify a pattern, with the same syntax that is used
24603 in @command{guix package --list-generations}, to restrict the list of
24604 generations displayed. For instance, the following command displays
24605 generations that are up to 10 days old:
24608 $ guix system list-generations 10d
24613 The @command{guix system} command has even more to offer! The following
24614 sub-commands allow you to visualize how your system services relate to
24617 @anchor{system-extension-graph}
24620 @item extension-graph
24621 Emit in Dot/Graphviz format to standard output the @dfn{service
24622 extension graph} of the operating system defined in @var{file}
24623 (@pxref{Service Composition}, for more information on service
24629 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
24632 produces a PDF file showing the extension relations among services.
24634 @anchor{system-shepherd-graph}
24635 @item shepherd-graph
24636 Emit in Dot/Graphviz format to standard output the @dfn{dependency
24637 graph} of shepherd services of the operating system defined in
24638 @var{file}. @xref{Shepherd Services}, for more information and for an
24643 @node Running Guix in a VM
24644 @section Running Guix in a Virtual Machine
24646 @cindex virtual machine
24647 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
24649 @indicateurl{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.@var{system}.xz}
24650 This image is a compressed image in QCOW format. You will first need to
24651 decompress with @command{xz -d}, and then you can pass it to an emulator such
24652 as QEMU (see below for details).
24654 This image boots the Xfce graphical environment and it contains some
24655 commonly-used tools. You can install more software in the image by running
24656 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
24657 also reconfigure the system based on its initial configuration file available
24658 as @file{/etc/config.scm} (@pxref{Using the Configuration System}).
24660 Instead of using this pre-built image, one can also build their own virtual
24661 machine image using @command{guix system vm-image} (@pxref{Invoking guix
24662 system}). The returned image is in qcow2 format, which the
24663 @uref{http://qemu.org/, QEMU emulator} can efficiently use.
24666 If you built your own image, you must copy it out of the store
24667 (@pxref{The Store}) and give yourself permission to write to the copy
24668 before you can use it. When invoking QEMU, you must choose a system
24669 emulator that is suitable for your hardware platform. Here is a minimal
24670 QEMU invocation that will boot the result of @command{guix system
24671 vm-image} on x86_64 hardware:
24674 $ qemu-system-x86_64 \
24675 -net user -net nic,model=virtio \
24676 -enable-kvm -m 512 \
24677 -device virtio-blk,drive=myhd \
24678 -drive if=none,file=/tmp/qemu-image,id=myhd
24681 Here is what each of these options means:
24684 @item qemu-system-x86_64
24685 This specifies the hardware platform to emulate. This should match the
24689 Enable the unprivileged user-mode network stack. The guest OS can
24690 access the host but not vice versa. This is the simplest way to get the
24693 @item -net nic,model=virtio
24694 You must create a network interface of a given model. If you do not
24695 create a NIC, the boot will fail. Assuming your hardware platform is
24696 x86_64, you can get a list of available NIC models by running
24697 @command{qemu-system-x86_64 -net nic,model=help}.
24700 If your system has hardware virtualization extensions, enabling the
24701 virtual machine support (KVM) of the Linux kernel will make things run
24704 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
24706 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
24707 which may be insufficient for some operations.
24709 @item -device virtio-blk,drive=myhd
24710 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
24711 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
24712 better performance than if it were emulating a complete disk drive. See the
24713 QEMU and KVM documentation for more info.
24715 @item -drive if=none,file=/tmp/qemu-image,id=myhd
24716 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
24717 the ``myhd'' drive.
24720 The default @command{run-vm.sh} script that is returned by an invocation of
24721 @command{guix system vm} does not add a @command{-net user} flag by default.
24722 To get network access from within the vm add the @code{(dhcp-client-service)}
24723 to your system definition and start the VM using
24724 @command{`guix system vm config.scm` -net user}. An important caveat of using
24725 @command{-net user} for networking is that @command{ping} will not work, because
24726 it uses the ICMP protocol. You'll have to use a different command to check for
24727 network connectivity, for example @command{guix download}.
24729 @subsection Connecting Through SSH
24733 To enable SSH inside a VM you need to add an SSH server like
24734 @code{openssh-service-type} to your VM (@pxref{Networking Services,
24735 @code{openssh-service-type}}). In addition you need to forward the SSH port,
24736 22 by default, to the host. You can do this with
24739 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
24742 To connect to the VM you can run
24745 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
24748 The @command{-p} tells @command{ssh} the port you want to connect to.
24749 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
24750 every time you modify your @command{config.scm} file and the
24751 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
24752 connection to an unknown host every time you connect.
24754 @subsection Using @command{virt-viewer} with Spice
24756 As an alternative to the default @command{qemu} graphical client you can
24757 use the @command{remote-viewer} from the @command{virt-viewer} package. To
24758 connect pass the @command{-spice port=5930,disable-ticketing} flag to
24759 @command{qemu}. See previous section for further information on how to do this.
24761 Spice also allows you to do some nice stuff like share your clipboard with your
24762 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
24765 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
24766 -chardev spicevmc,name=vdagent,id=vdagent
24767 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
24768 name=com.redhat.spice.0
24771 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
24773 @node Defining Services
24774 @section Defining Services
24776 The previous sections show the available services and how one can combine
24777 them in an @code{operating-system} declaration. But how do we define
24778 them in the first place? And what is a service anyway?
24781 * Service Composition:: The model for composing services.
24782 * Service Types and Services:: Types and services.
24783 * Service Reference:: API reference.
24784 * Shepherd Services:: A particular type of service.
24787 @node Service Composition
24788 @subsection Service Composition
24792 Here we define a @dfn{service} as, broadly, something that extends the
24793 functionality of the operating system. Often a service is a process---a
24794 @dfn{daemon}---started when the system boots: a secure shell server, a
24795 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
24796 whose execution can be triggered by another daemon---e.g., an FTP server
24797 started by @command{inetd} or a D-Bus service activated by
24798 @command{dbus-daemon}. Occasionally, a service does not map to a
24799 daemon. For instance, the ``account'' service collects user accounts
24800 and makes sure they exist when the system runs; the ``udev'' service
24801 collects device management rules and makes them available to the eudev
24802 daemon; the @file{/etc} service populates the @file{/etc} directory
24805 @cindex service extensions
24806 Guix system services are connected by @dfn{extensions}. For instance, the
24807 secure shell service @emph{extends} the Shepherd---the
24808 initialization system, running as PID@tie{}1---by giving it the command
24809 lines to start and stop the secure shell daemon (@pxref{Networking
24810 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
24811 service by passing it its @file{.service} specification, and extends the
24812 udev service by passing it device management rules (@pxref{Desktop
24813 Services, @code{upower-service}}); the Guix daemon service extends the
24814 Shepherd by passing it the command lines to start and stop the daemon,
24815 and extends the account service by passing it a list of required build
24816 user accounts (@pxref{Base Services}).
24818 All in all, services and their ``extends'' relations form a directed
24819 acyclic graph (DAG). If we represent services as boxes and extensions
24820 as arrows, a typical system might provide something like this:
24822 @image{images/service-graph,,5in,Typical service extension graph.}
24824 @cindex system service
24825 At the bottom, we see the @dfn{system service}, which produces the
24826 directory containing everything to run and boot the system, as returned
24827 by the @command{guix system build} command. @xref{Service Reference},
24828 to learn about the other service types shown here.
24829 @xref{system-extension-graph, the @command{guix system extension-graph}
24830 command}, for information on how to generate this representation for a
24831 particular operating system definition.
24833 @cindex service types
24834 Technically, developers can define @dfn{service types} to express these
24835 relations. There can be any number of services of a given type on the
24836 system---for instance, a system running two instances of the GNU secure
24837 shell server (lsh) has two instances of @code{lsh-service-type}, with
24838 different parameters.
24840 The following section describes the programming interface for service
24841 types and services.
24843 @node Service Types and Services
24844 @subsection Service Types and Services
24846 A @dfn{service type} is a node in the DAG described above. Let us start
24847 with a simple example, the service type for the Guix build daemon
24848 (@pxref{Invoking guix-daemon}):
24851 (define guix-service-type
24855 (list (service-extension shepherd-root-service-type guix-shepherd-service)
24856 (service-extension account-service-type guix-accounts)
24857 (service-extension activation-service-type guix-activation)))
24858 (default-value (guix-configuration))))
24862 It defines three things:
24866 A name, whose sole purpose is to make inspection and debugging easier.
24869 A list of @dfn{service extensions}, where each extension designates the
24870 target service type and a procedure that, given the parameters of the
24871 service, returns a list of objects to extend the service of that type.
24873 Every service type has at least one service extension. The only
24874 exception is the @dfn{boot service type}, which is the ultimate service.
24877 Optionally, a default value for instances of this type.
24880 In this example, @code{guix-service-type} extends three services:
24883 @item shepherd-root-service-type
24884 The @code{guix-shepherd-service} procedure defines how the Shepherd
24885 service is extended. Namely, it returns a @code{<shepherd-service>}
24886 object that defines how @command{guix-daemon} is started and stopped
24887 (@pxref{Shepherd Services}).
24889 @item account-service-type
24890 This extension for this service is computed by @code{guix-accounts},
24891 which returns a list of @code{user-group} and @code{user-account}
24892 objects representing the build user accounts (@pxref{Invoking
24895 @item activation-service-type
24896 Here @code{guix-activation} is a procedure that returns a gexp, which is
24897 a code snippet to run at ``activation time''---e.g., when the service is
24901 A service of this type is instantiated like this:
24904 (service guix-service-type
24905 (guix-configuration
24907 (use-substitutes? #f)))
24910 The second argument to the @code{service} form is a value representing
24911 the parameters of this specific service instance.
24912 @xref{guix-configuration-type, @code{guix-configuration}}, for
24913 information about the @code{guix-configuration} data type. When the
24914 value is omitted, the default value specified by
24915 @code{guix-service-type} is used:
24918 (service guix-service-type)
24921 @code{guix-service-type} is quite simple because it extends other
24922 services but is not extensible itself.
24924 @c @subsubsubsection Extensible Service Types
24926 The service type for an @emph{extensible} service looks like this:
24929 (define udev-service-type
24930 (service-type (name 'udev)
24932 (list (service-extension shepherd-root-service-type
24933 udev-shepherd-service)))
24935 (compose concatenate) ;concatenate the list of rules
24936 (extend (lambda (config rules)
24938 (($ <udev-configuration> udev initial-rules)
24939 (udev-configuration
24940 (udev udev) ;the udev package to use
24941 (rules (append initial-rules rules)))))))))
24944 This is the service type for the
24945 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
24946 management daemon}. Compared to the previous example, in addition to an
24947 extension of @code{shepherd-root-service-type}, we see two new fields:
24951 This is the procedure to @dfn{compose} the list of extensions to
24952 services of this type.
24954 Services can extend the udev service by passing it lists of rules; we
24955 compose those extensions simply by concatenating them.
24958 This procedure defines how the value of the service is @dfn{extended} with
24959 the composition of the extensions.
24961 Udev extensions are composed into a list of rules, but the udev service
24962 value is itself a @code{<udev-configuration>} record. So here, we
24963 extend that record by appending the list of rules it contains to the
24964 list of contributed rules.
24967 This is a string giving an overview of the service type. The string can
24968 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
24969 @command{guix system search} command searches these strings and displays
24970 them (@pxref{Invoking guix system}).
24973 There can be only one instance of an extensible service type such as
24974 @code{udev-service-type}. If there were more, the
24975 @code{service-extension} specifications would be ambiguous.
24977 Still here? The next section provides a reference of the programming
24978 interface for services.
24980 @node Service Reference
24981 @subsection Service Reference
24983 We have seen an overview of service types (@pxref{Service Types and
24984 Services}). This section provides a reference on how to manipulate
24985 services and service types. This interface is provided by the
24986 @code{(gnu services)} module.
24988 @deffn {Scheme Procedure} service @var{type} [@var{value}]
24989 Return a new service of @var{type}, a @code{<service-type>} object (see
24990 below.) @var{value} can be any object; it represents the parameters of
24991 this particular service instance.
24993 When @var{value} is omitted, the default value specified by @var{type}
24994 is used; if @var{type} does not specify a default value, an error is
24997 For instance, this:
25000 (service openssh-service-type)
25004 is equivalent to this:
25007 (service openssh-service-type
25008 (openssh-configuration))
25011 In both cases the result is an instance of @code{openssh-service-type}
25012 with the default configuration.
25015 @deffn {Scheme Procedure} service? @var{obj}
25016 Return true if @var{obj} is a service.
25019 @deffn {Scheme Procedure} service-kind @var{service}
25020 Return the type of @var{service}---i.e., a @code{<service-type>} object.
25023 @deffn {Scheme Procedure} service-value @var{service}
25024 Return the value associated with @var{service}. It represents its
25028 Here is an example of how a service is created and manipulated:
25032 (service nginx-service-type
25033 (nginx-configuration
25035 (log-directory log-directory)
25036 (run-directory run-directory)
25037 (file config-file))))
25042 (eq? (service-kind s) nginx-service-type)
25046 The @code{modify-services} form provides a handy way to change the
25047 parameters of some of the services of a list such as
25048 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
25049 evaluates to a list of services. Of course, you could always use
25050 standard list combinators such as @code{map} and @code{fold} to do that
25051 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
25052 @code{modify-services} simply provides a more concise form for this
25055 @deffn {Scheme Syntax} modify-services @var{services} @
25056 (@var{type} @var{variable} => @var{body}) @dots{}
25058 Modify the services listed in @var{services} according to the given
25059 clauses. Each clause has the form:
25062 (@var{type} @var{variable} => @var{body})
25065 where @var{type} is a service type---e.g.,
25066 @code{guix-service-type}---and @var{variable} is an identifier that is
25067 bound within the @var{body} to the service parameters---e.g., a
25068 @code{guix-configuration} instance---of the original service of that
25071 The @var{body} should evaluate to the new service parameters, which will
25072 be used to configure the new service. This new service will replace the
25073 original in the resulting list. Because a service's service parameters
25074 are created using @code{define-record-type*}, you can write a succinct
25075 @var{body} that evaluates to the new service parameters by using the
25076 @code{inherit} feature that @code{define-record-type*} provides.
25078 @xref{Using the Configuration System}, for example usage.
25082 Next comes the programming interface for service types. This is
25083 something you want to know when writing new service definitions, but not
25084 necessarily when simply looking for ways to customize your
25085 @code{operating-system} declaration.
25087 @deftp {Data Type} service-type
25088 @cindex service type
25089 This is the representation of a @dfn{service type} (@pxref{Service Types
25094 This is a symbol, used only to simplify inspection and debugging.
25096 @item @code{extensions}
25097 A non-empty list of @code{<service-extension>} objects (see below).
25099 @item @code{compose} (default: @code{#f})
25100 If this is @code{#f}, then the service type denotes services that cannot
25101 be extended---i.e., services that do not receive ``values'' from other
25104 Otherwise, it must be a one-argument procedure. The procedure is called
25105 by @code{fold-services} and is passed a list of values collected from
25106 extensions. It may return any single value.
25108 @item @code{extend} (default: @code{#f})
25109 If this is @code{#f}, services of this type cannot be extended.
25111 Otherwise, it must be a two-argument procedure: @code{fold-services}
25112 calls it, passing it the initial value of the service as the first
25113 argument and the result of applying @code{compose} to the extension
25114 values as the second argument. It must return a value that is a valid
25115 parameter value for the service instance.
25118 @xref{Service Types and Services}, for examples.
25121 @deffn {Scheme Procedure} service-extension @var{target-type} @
25123 Return a new extension for services of type @var{target-type}.
25124 @var{compute} must be a one-argument procedure: @code{fold-services}
25125 calls it, passing it the value associated with the service that provides
25126 the extension; it must return a valid value for the target service.
25129 @deffn {Scheme Procedure} service-extension? @var{obj}
25130 Return true if @var{obj} is a service extension.
25133 Occasionally, you might want to simply extend an existing service. This
25134 involves creating a new service type and specifying the extension of
25135 interest, which can be verbose; the @code{simple-service} procedure
25136 provides a shorthand for this.
25138 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
25139 Return a service that extends @var{target} with @var{value}. This works
25140 by creating a singleton service type @var{name}, of which the returned
25141 service is an instance.
25143 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
25147 (simple-service 'my-mcron-job mcron-service-type
25148 #~(job '(next-hour (3)) "guix gc -F 2G"))
25152 At the core of the service abstraction lies the @code{fold-services}
25153 procedure, which is responsible for ``compiling'' a list of services
25154 down to a single directory that contains everything needed to boot and
25155 run the system---the directory shown by the @command{guix system build}
25156 command (@pxref{Invoking guix system}). In essence, it propagates
25157 service extensions down the service graph, updating each node parameters
25158 on the way, until it reaches the root node.
25160 @deffn {Scheme Procedure} fold-services @var{services} @
25161 [#:target-type @var{system-service-type}]
25162 Fold @var{services} by propagating their extensions down to the root of
25163 type @var{target-type}; return the root service adjusted accordingly.
25166 Lastly, the @code{(gnu services)} module also defines several essential
25167 service types, some of which are listed below.
25169 @defvr {Scheme Variable} system-service-type
25170 This is the root of the service graph. It produces the system directory
25171 as returned by the @command{guix system build} command.
25174 @defvr {Scheme Variable} boot-service-type
25175 The type of the ``boot service'', which produces the @dfn{boot script}.
25176 The boot script is what the initial RAM disk runs when booting.
25179 @defvr {Scheme Variable} etc-service-type
25180 The type of the @file{/etc} service. This service is used to create
25181 files under @file{/etc} and can be extended by
25182 passing it name/file tuples such as:
25185 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
25188 In this example, the effect would be to add an @file{/etc/issue} file
25189 pointing to the given file.
25192 @defvr {Scheme Variable} setuid-program-service-type
25193 Type for the ``setuid-program service''. This service collects lists of
25194 executable file names, passed as gexps, and adds them to the set of
25195 setuid-root programs on the system (@pxref{Setuid Programs}).
25198 @defvr {Scheme Variable} profile-service-type
25199 Type of the service that populates the @dfn{system profile}---i.e., the
25200 programs under @file{/run/current-system/profile}. Other services can
25201 extend it by passing it lists of packages to add to the system profile.
25205 @node Shepherd Services
25206 @subsection Shepherd Services
25208 @cindex shepherd services
25210 @cindex init system
25211 The @code{(gnu services shepherd)} module provides a way to define
25212 services managed by the GNU@tie{}Shepherd, which is the
25213 initialization system---the first process that is started when the
25214 system boots, also known as PID@tie{}1
25215 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
25217 Services in the Shepherd can depend on each other. For instance, the
25218 SSH daemon may need to be started after the syslog daemon has been
25219 started, which in turn can only happen once all the file systems have
25220 been mounted. The simple operating system defined earlier (@pxref{Using
25221 the Configuration System}) results in a service graph like this:
25223 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
25225 You can actually generate such a graph for any operating system
25226 definition using the @command{guix system shepherd-graph} command
25227 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
25229 The @code{%shepherd-root-service} is a service object representing
25230 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
25231 by passing it lists of @code{<shepherd-service>} objects.
25233 @deftp {Data Type} shepherd-service
25234 The data type representing a service managed by the Shepherd.
25237 @item @code{provision}
25238 This is a list of symbols denoting what the service provides.
25240 These are the names that may be passed to @command{herd start},
25241 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
25242 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
25243 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
25245 @item @code{requirements} (default: @code{'()})
25246 List of symbols denoting the Shepherd services this one depends on.
25248 @cindex one-shot services, for the Shepherd
25249 @item @code{one-shot?} (default: @code{#f})
25250 Whether this service is @dfn{one-shot}. One-shot services stop immediately
25251 after their @code{start} action has completed. @xref{Slots of services,,,
25252 shepherd, The GNU Shepherd Manual}, for more info.
25254 @item @code{respawn?} (default: @code{#t})
25255 Whether to restart the service when it stops, for instance when the
25256 underlying process dies.
25259 @itemx @code{stop} (default: @code{#~(const #f)})
25260 The @code{start} and @code{stop} fields refer to the Shepherd's
25261 facilities to start and stop processes (@pxref{Service De- and
25262 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
25263 G-expressions that get expanded in the Shepherd configuration file
25264 (@pxref{G-Expressions}).
25266 @item @code{actions} (default: @code{'()})
25267 @cindex actions, of Shepherd services
25268 This is a list of @code{shepherd-action} objects (see below) defining
25269 @dfn{actions} supported by the service, in addition to the standard
25270 @code{start} and @code{stop} actions. Actions listed here become available as
25271 @command{herd} sub-commands:
25274 herd @var{action} @var{service} [@var{arguments}@dots{}]
25277 @item @code{documentation}
25278 A documentation string, as shown when running:
25281 herd doc @var{service-name}
25284 where @var{service-name} is one of the symbols in @code{provision}
25285 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
25287 @item @code{modules} (default: @code{%default-modules})
25288 This is the list of modules that must be in scope when @code{start} and
25289 @code{stop} are evaluated.
25294 @deftp {Data Type} shepherd-action
25295 This is the data type that defines additional actions implemented by a
25296 Shepherd service (see above).
25300 Symbol naming the action.
25302 @item documentation
25303 This is a documentation string for the action. It can be viewed by running:
25306 herd doc @var{service} action @var{action}
25310 This should be a gexp that evaluates to a procedure of at least one argument,
25311 which is the ``running value'' of the service (@pxref{Slots of services,,,
25312 shepherd, The GNU Shepherd Manual}).
25315 The following example defines an action called @code{say-hello} that kindly
25321 (documentation "Say hi!")
25322 (procedure #~(lambda (running . args)
25323 (format #t "Hello, friend! arguments: ~s\n"
25328 Assuming this action is added to the @code{example} service, then you can do:
25331 # herd say-hello example
25332 Hello, friend! arguments: ()
25333 # herd say-hello example a b c
25334 Hello, friend! arguments: ("a" "b" "c")
25337 This, as you can see, is a fairly sophisticated way to say hello.
25338 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
25342 @defvr {Scheme Variable} shepherd-root-service-type
25343 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
25345 This is the service type that extensions target when they want to create
25346 shepherd services (@pxref{Service Types and Services}, for an example).
25347 Each extension must pass a list of @code{<shepherd-service>}.
25350 @defvr {Scheme Variable} %shepherd-root-service
25351 This service represents PID@tie{}1.
25355 @node Documentation
25356 @chapter Documentation
25358 @cindex documentation, searching for
25359 @cindex searching for documentation
25360 @cindex Info, documentation format
25362 @cindex manual pages
25363 In most cases packages installed with Guix come with documentation.
25364 There are two main documentation formats: ``Info'', a browseable
25365 hypertext format used for GNU software, and ``manual pages'' (or ``man
25366 pages''), the linear documentation format traditionally found on Unix.
25367 Info manuals are accessed with the @command{info} command or with Emacs,
25368 and man pages are accessed using @command{man}.
25370 You can look for documentation of software installed on your system by
25371 keyword. For example, the following command searches for information
25372 about ``TLS'' in Info manuals:
25376 "(emacs)Network Security" -- STARTTLS
25377 "(emacs)Network Security" -- TLS
25378 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
25379 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
25384 The command below searches for the same keyword in man pages:
25388 SSL (7) - OpenSSL SSL/TLS library
25389 certtool (1) - GnuTLS certificate tool
25393 These searches are purely local to your computer so you have the
25394 guarantee that documentation you find corresponds to what you have
25395 actually installed, you can access it off-line, and your privacy is
25398 Once you have these results, you can view the relevant documentation by
25402 $ info "(gnutls)Core TLS API"
25412 Info manuals contain sections and indices as well as hyperlinks like
25413 those found in Web pages. The @command{info} reader (@pxref{Top, Info
25414 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
25415 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
25416 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
25417 Introduction}, for an introduction to Info navigation.
25419 @node Installing Debugging Files
25420 @chapter Installing Debugging Files
25422 @cindex debugging files
25423 Program binaries, as produced by the GCC compilers for instance, are
25424 typically written in the ELF format, with a section containing
25425 @dfn{debugging information}. Debugging information is what allows the
25426 debugger, GDB, to map binary code to source code; it is required to
25427 debug a compiled program in good conditions.
25429 The problem with debugging information is that is takes up a fair amount
25430 of disk space. For example, debugging information for the GNU C Library
25431 weighs in at more than 60 MiB. Thus, as a user, keeping all the
25432 debugging info of all the installed programs is usually not an option.
25433 Yet, space savings should not come at the cost of an impediment to
25434 debugging---especially in the GNU system, which should make it easier
25435 for users to exert their computing freedom (@pxref{GNU Distribution}).
25437 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
25438 mechanism that allows users to get the best of both worlds: debugging
25439 information can be stripped from the binaries and stored in separate
25440 files. GDB is then able to load debugging information from those files,
25441 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
25444 The GNU distribution takes advantage of this by storing debugging
25445 information in the @code{lib/debug} sub-directory of a separate package
25446 output unimaginatively called @code{debug} (@pxref{Packages with
25447 Multiple Outputs}). Users can choose to install the @code{debug} output
25448 of a package when they need it. For instance, the following command
25449 installs the debugging information for the GNU C Library and for GNU
25453 guix install glibc:debug guile:debug
25456 GDB must then be told to look for debug files in the user's profile, by
25457 setting the @code{debug-file-directory} variable (consider setting it
25458 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
25462 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
25465 From there on, GDB will pick up debugging information from the
25466 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
25468 In addition, you will most likely want GDB to be able to show the source
25469 code being debugged. To do that, you will have to unpack the source
25470 code of the package of interest (obtained with @code{guix build
25471 --source}, @pxref{Invoking guix build}), and to point GDB to that source
25472 directory using the @code{directory} command (@pxref{Source Path,
25473 @code{directory},, gdb, Debugging with GDB}).
25475 @c XXX: keep me up-to-date
25476 The @code{debug} output mechanism in Guix is implemented by the
25477 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
25478 opt-in---debugging information is available only for the packages
25479 with definitions explicitly declaring a @code{debug} output. This may be
25480 changed to opt-out in the future if our build farm servers can handle
25481 the load. To check whether a package has a @code{debug} output, use
25482 @command{guix package --list-available} (@pxref{Invoking guix package}).
25485 @node Security Updates
25486 @chapter Security Updates
25488 @cindex security updates
25489 @cindex security vulnerabilities
25490 Occasionally, important security vulnerabilities are discovered in software
25491 packages and must be patched. Guix developers try hard to keep track of
25492 known vulnerabilities and to apply fixes as soon as possible in the
25493 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
25494 containing only security updates.) The @command{guix lint} tool helps
25495 developers find out about vulnerable versions of software packages in the
25500 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
25501 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
25502 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
25506 @xref{Invoking guix lint}, for more information.
25509 As of version @value{VERSION}, the feature described below is considered
25513 Guix follows a functional
25514 package management discipline (@pxref{Introduction}), which implies
25515 that, when a package is changed, @emph{every package that depends on it}
25516 must be rebuilt. This can significantly slow down the deployment of
25517 fixes in core packages such as libc or Bash, since basically the whole
25518 distribution would need to be rebuilt. Using pre-built binaries helps
25519 (@pxref{Substitutes}), but deployment may still take more time than
25523 To address this, Guix implements @dfn{grafts}, a mechanism that allows
25524 for fast deployment of critical updates without the costs associated
25525 with a whole-distribution rebuild. The idea is to rebuild only the
25526 package that needs to be patched, and then to ``graft'' it onto packages
25527 explicitly installed by the user and that were previously referring to
25528 the original package. The cost of grafting is typically very low, and
25529 order of magnitudes lower than a full rebuild of the dependency chain.
25531 @cindex replacements of packages, for grafts
25532 For instance, suppose a security update needs to be applied to Bash.
25533 Guix developers will provide a package definition for the ``fixed''
25534 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
25535 Packages}). Then, the original package definition is augmented with a
25536 @code{replacement} field pointing to the package containing the bug fix:
25543 (replacement bash-fixed)))
25546 From there on, any package depending directly or indirectly on Bash---as
25547 reported by @command{guix gc --requisites} (@pxref{Invoking guix
25548 gc})---that is installed is automatically ``rewritten'' to refer to
25549 @code{bash-fixed} instead of @code{bash}. This grafting process takes
25550 time proportional to the size of the package, usually less than a
25551 minute for an ``average'' package on a recent machine. Grafting is
25552 recursive: when an indirect dependency requires grafting, then grafting
25553 ``propagates'' up to the package that the user is installing.
25555 Currently, the length of the name and version of the graft and that of
25556 the package it replaces (@code{bash-fixed} and @code{bash} in the example
25557 above) must be equal. This restriction mostly comes from the fact that
25558 grafting works by patching files, including binary files, directly.
25559 Other restrictions may apply: for instance, when adding a graft to a
25560 package providing a shared library, the original shared library and its
25561 replacement must have the same @code{SONAME} and be binary-compatible.
25563 The @option{--no-grafts} command-line option allows you to forcefully
25564 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
25568 guix build bash --no-grafts
25572 returns the store file name of the original Bash, whereas:
25579 returns the store file name of the ``fixed'', replacement Bash. This
25580 allows you to distinguish between the two variants of Bash.
25582 To verify which Bash your whole profile refers to, you can run
25583 (@pxref{Invoking guix gc}):
25586 guix gc -R `readlink -f ~/.guix-profile` | grep bash
25590 @dots{} and compare the store file names that you get with those above.
25591 Likewise for a complete Guix system generation:
25594 guix gc -R `guix system build my-config.scm` | grep bash
25597 Lastly, to check which Bash running processes are using, you can use the
25598 @command{lsof} command:
25601 lsof | grep /gnu/store/.*bash
25605 @node Bootstrapping
25606 @chapter Bootstrapping
25608 @c Adapted from the ELS 2013 paper.
25610 @cindex bootstrapping
25612 Bootstrapping in our context refers to how the distribution gets built
25613 ``from nothing''. Remember that the build environment of a derivation
25614 contains nothing but its declared inputs (@pxref{Introduction}). So
25615 there's an obvious chicken-and-egg problem: how does the first package
25616 get built? How does the first compiler get compiled? Note that this is
25617 a question of interest only to the curious hacker, not to the regular
25618 user, so you can shamelessly skip this section if you consider yourself
25619 a ``regular user''.
25621 @cindex bootstrap binaries
25622 The GNU system is primarily made of C code, with libc at its core. The
25623 GNU build system itself assumes the availability of a Bourne shell and
25624 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
25625 `grep'. Furthermore, build programs---programs that run
25626 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
25627 (@pxref{Derivations}). Consequently, to be able to build anything at
25628 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
25629 Binutils, libc, and the other packages mentioned above---the
25630 @dfn{bootstrap binaries}.
25632 These bootstrap binaries are ``taken for granted'', though we can also
25633 re-create them if needed (more on that later).
25635 @unnumberedsec Preparing to Use the Bootstrap Binaries
25637 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
25638 @c large image, it's hard to scroll. Oh well.
25639 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
25641 The figure above shows the very beginning of the dependency graph of the
25642 distribution, corresponding to the package definitions of the @code{(gnu
25643 packages bootstrap)} module. A similar figure can be generated with
25644 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
25647 guix graph -t derivation \
25648 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
25652 At this level of detail, things are
25653 slightly complex. First, Guile itself consists of an ELF executable,
25654 along with many source and compiled Scheme files that are dynamically
25655 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
25656 tarball shown in this graph. This tarball is part of Guix's ``source''
25657 distribution, and gets inserted into the store with @code{add-to-store}
25658 (@pxref{The Store}).
25660 But how do we write a derivation that unpacks this tarball and adds it
25661 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
25662 derivation---the first one that gets built---uses @code{bash} as its
25663 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
25664 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
25665 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
25666 the Guix source distribution, whose sole purpose is to allow the Guile
25667 tarball to be unpacked.
25669 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
25670 Guile that can be used to run subsequent build programs. Its first task
25671 is to download tarballs containing the other pre-built binaries---this
25672 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
25673 @code{ftp-client.scm} are used for this purpose. The
25674 @code{module-import.drv} derivations import those modules in a directory
25675 in the store, using the original layout. The
25676 @code{module-import-compiled.drv} derivations compile those modules, and
25677 write them in an output directory with the right layout. This
25678 corresponds to the @code{#:modules} argument of
25679 @code{build-expression->derivation} (@pxref{Derivations}).
25681 Finally, the various tarballs are unpacked by the
25682 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
25683 etc., at which point we have a working C tool chain.
25686 @unnumberedsec Building the Build Tools
25688 Bootstrapping is complete when we have a full tool chain that does not
25689 depend on the pre-built bootstrap tools discussed above. This
25690 no-dependency requirement is verified by checking whether the files of
25691 the final tool chain contain references to the @file{/gnu/store}
25692 directories of the bootstrap inputs. The process that leads to this
25693 ``final'' tool chain is described by the package definitions found in
25694 the @code{(gnu packages commencement)} module.
25696 The @command{guix graph} command allows us to ``zoom out'' compared to
25697 the graph above, by looking at the level of package objects instead of
25698 individual derivations---remember that a package may translate to
25699 several derivations, typically one derivation to download its source,
25700 one to build the Guile modules it needs, and one to actually build the
25701 package from source. The command:
25704 guix graph -t bag \
25705 -e '(@@@@ (gnu packages commencement)
25706 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
25710 produces the dependency graph leading to the ``final'' C
25711 library@footnote{You may notice the @code{glibc-intermediate} label,
25712 suggesting that it is not @emph{quite} final, but as a good
25713 approximation, we will consider it final.}, depicted below.
25715 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
25717 @c See <http://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
25718 The first tool that gets built with the bootstrap binaries is
25719 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
25720 for all the following packages. From there Findutils and Diffutils get
25723 Then come the first-stage Binutils and GCC, built as pseudo cross
25724 tools---i.e., with @code{--target} equal to @code{--host}. They are
25725 used to build libc. Thanks to this cross-build trick, this libc is
25726 guaranteed not to hold any reference to the initial tool chain.
25728 From there the final Binutils and GCC (not shown above) are built.
25730 from the final Binutils, and links programs against the just-built libc.
25731 This tool chain is used to build the other packages used by Guix and by
25732 the GNU Build System: Guile, Bash, Coreutils, etc.
25734 And voilà! At this point we have the complete set of build tools that
25735 the GNU Build System expects. These are in the @code{%final-inputs}
25736 variable of the @code{(gnu packages commencement)} module, and are
25737 implicitly used by any package that uses @code{gnu-build-system}
25738 (@pxref{Build Systems, @code{gnu-build-system}}).
25741 @unnumberedsec Building the Bootstrap Binaries
25743 @cindex bootstrap binaries
25744 Because the final tool chain does not depend on the bootstrap binaries,
25745 those rarely need to be updated. Nevertheless, it is useful to have an
25746 automated way to produce them, should an update occur, and this is what
25747 the @code{(gnu packages make-bootstrap)} module provides.
25749 The following command builds the tarballs containing the bootstrap
25750 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
25751 of Coreutils and other basic command-line tools):
25754 guix build bootstrap-tarballs
25757 The generated tarballs are those that should be referred to in the
25758 @code{(gnu packages bootstrap)} module mentioned at the beginning of
25761 Still here? Then perhaps by now you've started to wonder: when do we
25762 reach a fixed point? That is an interesting question! The answer is
25763 unknown, but if you would like to investigate further (and have
25764 significant computational and storage resources to do so), then let us
25767 @unnumberedsec Reducing the Set of Bootstrap Binaries
25769 Our bootstrap binaries currently include GCC, Guile, etc. That's a lot
25770 of binary code! Why is that a problem? It's a problem because these
25771 big chunks of binary code are practically non-auditable, which makes it
25772 hard to establish what source code produced them. Every unauditable
25773 binary also leaves us vulnerable to compiler backdoors as described by
25774 Ken Thompson in the 1984 paper @emph{Reflections on Trusting Trust}.
25776 This is mitigated by the fact that our bootstrap binaries were generated
25777 from an earlier Guix revision. Nevertheless it lacks the level of
25778 transparency that we get in the rest of the package dependency graph,
25779 where Guix always gives us a source-to-binary mapping. Thus, our goal
25780 is to reduce the set of bootstrap binaries to the bare minimum.
25782 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
25783 on-going projects to do that. One of these is about replacing the
25784 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
25785 of increasing complexity, which could be built from source starting from
25786 a simple and auditable assembler. Your help is welcome!
25790 @chapter Porting to a New Platform
25792 As discussed above, the GNU distribution is self-contained, and
25793 self-containment is achieved by relying on pre-built ``bootstrap
25794 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
25795 operating system kernel, CPU architecture, and application binary
25796 interface (ABI). Thus, to port the distribution to a platform that is
25797 not yet supported, one must build those bootstrap binaries, and update
25798 the @code{(gnu packages bootstrap)} module to use them on that platform.
25800 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
25801 When everything goes well, and assuming the GNU tool chain supports the
25802 target platform, this can be as simple as running a command like this
25806 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
25809 For this to work, the @code{glibc-dynamic-linker} procedure in
25810 @code{(gnu packages bootstrap)} must be augmented to return the right
25811 file name for libc's dynamic linker on that platform; likewise,
25812 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
25813 taught about the new platform.
25815 Once these are built, the @code{(gnu packages bootstrap)} module needs
25816 to be updated to refer to these binaries on the target platform. That
25817 is, the hashes and URLs of the bootstrap tarballs for the new platform
25818 must be added alongside those of the currently supported platforms. The
25819 bootstrap Guile tarball is treated specially: it is expected to be
25820 available locally, and @file{gnu/local.mk} has rules to download it for
25821 the supported architectures; a rule for the new platform must be added
25824 In practice, there may be some complications. First, it may be that the
25825 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
25826 above) is not recognized by all the GNU tools. Typically, glibc
25827 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
25828 configure flag (see @code{gcc.scm} for examples of how to handle this).
25829 Second, some of the required packages could fail to build for that
25830 platform. Lastly, the generated binaries could be broken for some
25833 @c *********************************************************************
25834 @include contributing.texi
25836 @c *********************************************************************
25837 @node Acknowledgments
25838 @chapter Acknowledgments
25840 Guix is based on the @uref{http://nixos.org/nix/, Nix package manager},
25841 which was designed and
25842 implemented by Eelco Dolstra, with contributions from other people (see
25843 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
25844 management, and promoted unprecedented features, such as transactional
25845 package upgrades and rollbacks, per-user profiles, and referentially
25846 transparent build processes. Without this work, Guix would not exist.
25848 The Nix-based software distributions, Nixpkgs and NixOS, have also been
25849 an inspiration for Guix.
25851 GNU@tie{}Guix itself is a collective work with contributions from a
25852 number of people. See the @file{AUTHORS} file in Guix for more
25853 information on these fine people. The @file{THANKS} file lists people
25854 who have helped by reporting bugs, taking care of the infrastructure,
25855 providing artwork and themes, making suggestions, and more---thank you!
25858 @c *********************************************************************
25859 @node GNU Free Documentation License
25860 @appendix GNU Free Documentation License
25861 @cindex license, GNU Free Documentation License
25862 @include fdl-1.3.texi
25864 @c *********************************************************************
25865 @node Concept Index
25866 @unnumbered Concept Index
25869 @node Programming Index
25870 @unnumbered Programming Index
25871 @syncodeindex tp fn
25872 @syncodeindex vr fn
25877 @c Local Variables:
25878 @c ispell-local-dictionary: "american";