6 @documentencoding UTF-8
7 @settitle GNU Guix Reference Manual
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16 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018 Ludovic Courtès@*
17 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
18 Copyright @copyright{} 2013 Nikita Karetnikov@*
19 Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
20 Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
21 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
22 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
23 Copyright @copyright{} 2015, 2016, 2017 Leo Famulari@*
24 Copyright @copyright{} 2015, 2016, 2017, 2018 Ricardo Wurmus@*
25 Copyright @copyright{} 2016 Ben Woodcroft@*
26 Copyright @copyright{} 2016, 2017, 2018 Chris Marusich@*
27 Copyright @copyright{} 2016, 2017, 2018 Efraim Flashner@*
28 Copyright @copyright{} 2016 John Darrington@*
29 Copyright @copyright{} 2016, 2017 Nils Gillmann@*
30 Copyright @copyright{} 2016, 2017 Jan Nieuwenhuizen@*
31 Copyright @copyright{} 2016 Julien Lepiller@*
32 Copyright @copyright{} 2016 Alex ter Weele@*
33 Copyright @copyright{} 2017, 2018 Clément Lassieur@*
34 Copyright @copyright{} 2017 Mathieu Othacehe@*
35 Copyright @copyright{} 2017 Federico Beffa@*
36 Copyright @copyright{} 2017 Carlo Zancanaro@*
37 Copyright @copyright{} 2017 Thomas Danckaert@*
38 Copyright @copyright{} 2017 humanitiesNerd@*
39 Copyright @copyright{} 2017 Christopher Allan Webber@*
40 Copyright @copyright{} 2017, 2018 Marius Bakke@*
41 Copyright @copyright{} 2017 Hartmut Goebel@*
42 Copyright @copyright{} 2017 Maxim Cournoyer@*
43 Copyright @copyright{} 2017, 2018 Tobias Geerinckx-Rice@*
44 Copyright @copyright{} 2017 George Clemmer@*
45 Copyright @copyright{} 2017 Andy Wingo@*
46 Copyright @copyright{} 2017, 2018 Arun Isaac@*
47 Copyright @copyright{} 2017 nee@*
48 Copyright @copyright{} 2018 Rutger Helling@*
49 Copyright @copyright{} 2018 Oleg Pykhalov@*
50 Copyright @copyright{} 2018 Mike Gerwitz@*
51 Copyright @copyright{} 2018 Pierre-Antoine Rouby
53 Permission is granted to copy, distribute and/or modify this document
54 under the terms of the GNU Free Documentation License, Version 1.3 or
55 any later version published by the Free Software Foundation; with no
56 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
57 copy of the license is included in the section entitled ``GNU Free
58 Documentation License''.
61 @dircategory System administration
63 * Guix: (guix). Manage installed software and system configuration.
64 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
65 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
66 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
67 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
70 @dircategory Software development
72 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
73 * guix build: (guix)Invoking guix build. Building packages.
74 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
78 @title GNU Guix Reference Manual
79 @subtitle Using the GNU Guix Functional Package Manager
80 @author The GNU Guix Developers
83 @vskip 0pt plus 1filll
84 Edition @value{EDITION} @*
92 @c *********************************************************************
96 This document describes GNU Guix version @value{VERSION}, a functional
97 package management tool written for the GNU system.
100 * Introduction:: What is Guix about?
101 * Installation:: Installing Guix.
102 * Package Management:: Package installation, upgrade, etc.
103 * Programming Interface:: Using Guix in Scheme.
104 * Utilities:: Package management commands.
105 * GNU Distribution:: Software for your friendly GNU system.
106 * Contributing:: Your help needed!
108 * Acknowledgments:: Thanks!
109 * GNU Free Documentation License:: The license of this manual.
110 * Concept Index:: Concepts.
111 * Programming Index:: Data types, functions, and variables.
114 --- The Detailed Node Listing ---
118 * Binary Installation:: Getting Guix running in no time!
119 * Requirements:: Software needed to build and run Guix.
120 * Running the Test Suite:: Testing Guix.
121 * Setting Up the Daemon:: Preparing the build daemon's environment.
122 * Invoking guix-daemon:: Running the build daemon.
123 * Application Setup:: Application-specific setup.
125 Setting Up the Daemon
127 * Build Environment Setup:: Preparing the isolated build environment.
128 * Daemon Offload Setup:: Offloading builds to remote machines.
129 * SELinux Support:: Using an SELinux policy for the daemon.
133 * Features:: How Guix will make your life brighter.
134 * Invoking guix package:: Package installation, removal, etc.
135 * Substitutes:: Downloading pre-built binaries.
136 * Packages with Multiple Outputs:: Single source package, multiple outputs.
137 * Invoking guix gc:: Running the garbage collector.
138 * Invoking guix pull:: Fetching the latest Guix and distribution.
139 * Invoking guix pack:: Creating software bundles.
140 * Invoking guix archive:: Exporting and importing store files.
144 * Official Substitute Server:: One particular source of substitutes.
145 * Substitute Server Authorization:: How to enable or disable substitutes.
146 * Substitute Authentication:: How Guix verifies substitutes.
147 * Proxy Settings:: How to get substitutes via proxy.
148 * Substitution Failure:: What happens when substitution fails.
149 * On Trusting Binaries:: How can you trust that binary blob?
151 Programming Interface
153 * Defining Packages:: Defining new packages.
154 * Build Systems:: Specifying how packages are built.
155 * The Store:: Manipulating the package store.
156 * Derivations:: Low-level interface to package derivations.
157 * The Store Monad:: Purely functional interface to the store.
158 * G-Expressions:: Manipulating build expressions.
162 * package Reference :: The package data type.
163 * origin Reference:: The origin data type.
167 * Invoking guix build:: Building packages from the command line.
168 * Invoking guix edit:: Editing package definitions.
169 * Invoking guix download:: Downloading a file and printing its hash.
170 * Invoking guix hash:: Computing the cryptographic hash of a file.
171 * Invoking guix import:: Importing package definitions.
172 * Invoking guix refresh:: Updating package definitions.
173 * Invoking guix lint:: Finding errors in package definitions.
174 * Invoking guix size:: Profiling disk usage.
175 * Invoking guix graph:: Visualizing the graph of packages.
176 * Invoking guix environment:: Setting up development environments.
177 * Invoking guix publish:: Sharing substitutes.
178 * Invoking guix challenge:: Challenging substitute servers.
179 * Invoking guix copy:: Copying to and from a remote store.
180 * Invoking guix container:: Process isolation.
181 * Invoking guix weather:: Assessing substitute availability.
183 Invoking @command{guix build}
185 * Common Build Options:: Build options for most commands.
186 * Package Transformation Options:: Creating variants of packages.
187 * Additional Build Options:: Options specific to 'guix build'.
188 * Debugging Build Failures:: Real life packaging experience.
192 * System Installation:: Installing the whole operating system.
193 * System Configuration:: Configuring the operating system.
194 * Documentation:: Browsing software user manuals.
195 * Installing Debugging Files:: Feeding the debugger.
196 * Security Updates:: Deploying security fixes quickly.
197 * Package Modules:: Packages from the programmer's viewpoint.
198 * Packaging Guidelines:: Growing the distribution.
199 * Bootstrapping:: GNU/Linux built from scratch.
200 * Porting:: Targeting another platform or kernel.
204 * Limitations:: What you can expect.
205 * Hardware Considerations:: Supported hardware.
206 * USB Stick and DVD Installation:: Preparing the installation medium.
207 * Preparing for Installation:: Networking, partitioning, etc.
208 * Proceeding with the Installation:: The real thing.
209 * Installing GuixSD in a VM:: GuixSD playground.
210 * Building the Installation Image:: How this comes to be.
214 * Using the Configuration System:: Customizing your GNU system.
215 * operating-system Reference:: Detail of operating-system declarations.
216 * File Systems:: Configuring file system mounts.
217 * Mapped Devices:: Block device extra processing.
218 * User Accounts:: Specifying user accounts.
219 * Locales:: Language and cultural convention settings.
220 * Services:: Specifying system services.
221 * Setuid Programs:: Programs running with root privileges.
222 * X.509 Certificates:: Authenticating HTTPS servers.
223 * Name Service Switch:: Configuring libc's name service switch.
224 * Initial RAM Disk:: Linux-Libre bootstrapping.
225 * Bootloader Configuration:: Configuring the boot loader.
226 * Invoking guix system:: Instantiating a system configuration.
227 * Running GuixSD in a VM:: How to run GuixSD in a virtual machine.
228 * Defining Services:: Adding new service definitions.
232 * Base Services:: Essential system services.
233 * Scheduled Job Execution:: The mcron service.
234 * Log Rotation:: The rottlog service.
235 * Networking Services:: Network setup, SSH daemon, etc.
236 * X Window:: Graphical display.
237 * Printing Services:: Local and remote printer support.
238 * Desktop Services:: D-Bus and desktop services.
239 * Sound Services:: ALSA and Pulseaudio services.
240 * Database Services:: SQL databases, key-value stores, etc.
241 * Mail Services:: IMAP, POP3, SMTP, and all that.
242 * Messaging Services:: Messaging services.
243 * Telephony Services:: Telephony services.
244 * Monitoring Services:: Monitoring services.
245 * Kerberos Services:: Kerberos services.
246 * Web Services:: Web servers.
247 * Certificate Services:: TLS certificates via Let's Encrypt.
248 * DNS Services:: DNS daemons.
249 * VPN Services:: VPN daemons.
250 * Network File System:: NFS related services.
251 * Continuous Integration:: The Cuirass service.
252 * Power Management Services:: Extending battery life.
253 * Audio Services:: The MPD.
254 * Virtualization Services:: Virtualization services.
255 * Version Control Services:: Providing remote access to Git repositories.
256 * Game Services:: Game servers.
257 * Miscellaneous Services:: Other services.
261 * Service Composition:: The model for composing services.
262 * Service Types and Services:: Types and services.
263 * Service Reference:: API reference.
264 * Shepherd Services:: A particular type of service.
268 * Software Freedom:: What may go into the distribution.
269 * Package Naming:: What's in a name?
270 * Version Numbers:: When the name is not enough.
271 * Synopses and Descriptions:: Helping users find the right package.
272 * Python Modules:: A touch of British comedy.
273 * Perl Modules:: Little pearls.
274 * Java Packages:: Coffee break.
275 * Fonts:: Fond of fonts.
279 * Building from Git:: The latest and greatest.
280 * Running Guix Before It Is Installed:: Hacker tricks.
281 * The Perfect Setup:: The right tools.
282 * Coding Style:: Hygiene of the contributor.
283 * Submitting Patches:: Share your work.
287 * Programming Paradigm:: How to compose your elements.
288 * Modules:: Where to store your code?
289 * Data Types and Pattern Matching:: Implementing data structures.
290 * Formatting Code:: Writing conventions.
295 @c *********************************************************************
297 @chapter Introduction
300 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
301 using the international phonetic alphabet (IPA).} is a package
302 management tool for the GNU system. Guix makes it easy for unprivileged
303 users to install, upgrade, or remove packages, to roll back to a
304 previous package set, to build packages from source, and generally
305 assists with the creation and maintenance of software environments.
307 @cindex user interfaces
308 Guix provides a command-line package management interface
309 (@pxref{Invoking guix package}), a set of command-line utilities
310 (@pxref{Utilities}), as well as Scheme programming interfaces
311 (@pxref{Programming Interface}).
313 Its @dfn{build daemon} is responsible for building packages on behalf of
314 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
315 binaries from authorized sources (@pxref{Substitutes}).
317 @cindex extensibility of the distribution
318 @cindex customization, of packages
319 Guix includes package definitions for many GNU and non-GNU packages, all
320 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
321 user's computing freedom}. It is @emph{extensible}: users can write
322 their own package definitions (@pxref{Defining Packages}) and make them
323 available as independent package modules (@pxref{Package Modules}). It
324 is also @emph{customizable}: users can @emph{derive} specialized package
325 definitions from existing ones, including from the command line
326 (@pxref{Package Transformation Options}).
328 @cindex Guix System Distribution
330 You can install GNU@tie{}Guix on top of an existing GNU/Linux system
331 where it complements the available tools without interference
332 (@pxref{Installation}), or you can use it as part of the standalone
333 @dfn{Guix System Distribution} or GuixSD (@pxref{GNU Distribution}).
334 With GNU@tie{}GuixSD, you @emph{declare} all aspects of the operating
335 system configuration and Guix takes care of instantiating the
336 configuration in a transactional, reproducible, and stateless fashion
337 (@pxref{System Configuration}).
339 @cindex functional package management
340 Under the hood, Guix implements the @dfn{functional package management}
341 discipline pioneered by Nix (@pxref{Acknowledgments}).
342 In Guix, the package build and installation process is seen
343 as a @emph{function}, in the mathematical sense. That function takes inputs,
344 such as build scripts, a compiler, and libraries, and
345 returns an installed package. As a pure function, its result depends
346 solely on its inputs---for instance, it cannot refer to software or
347 scripts that were not explicitly passed as inputs. A build function
348 always produces the same result when passed a given set of inputs. It
349 cannot alter the environment of the running system in
350 any way; for instance, it cannot create, modify, or delete files outside
351 of its build and installation directories. This is achieved by running
352 build processes in isolated environments (or @dfn{containers}), where only their
353 explicit inputs are visible.
356 The result of package build functions is @dfn{cached} in the file
357 system, in a special directory called @dfn{the store} (@pxref{The
358 Store}). Each package is installed in a directory of its own in the
359 store---by default under @file{/gnu/store}. The directory name contains
360 a hash of all the inputs used to build that package; thus, changing an
361 input yields a different directory name.
363 This approach is the foundation for the salient features of Guix: support
364 for transactional package upgrade and rollback, per-user installation, and
365 garbage collection of packages (@pxref{Features}).
368 @c *********************************************************************
370 @chapter Installation
372 @cindex installing Guix
373 GNU Guix is available for download from its website at
374 @url{http://www.gnu.org/software/guix/}. This section describes the
375 software requirements of Guix, as well as how to install it and get
378 Note that this section is concerned with the installation of the package
379 manager, which can be done on top of a running GNU/Linux system. If,
380 instead, you want to install the complete GNU operating system,
381 @pxref{System Installation}.
383 @cindex foreign distro
384 When installed on a running GNU/Linux system---thereafter called a
385 @dfn{foreign distro}---GNU@tie{}Guix complements the available tools
386 without interference. Its data lives exclusively in two directories,
387 usually @file{/gnu/store} and @file{/var/guix}; other files on your
388 system, such as @file{/etc}, are left untouched.
390 Once installed, Guix can be updated by running @command{guix pull}
391 (@pxref{Invoking guix pull}).
394 * Binary Installation:: Getting Guix running in no time!
395 * Requirements:: Software needed to build and run Guix.
396 * Running the Test Suite:: Testing Guix.
397 * Setting Up the Daemon:: Preparing the build daemon's environment.
398 * Invoking guix-daemon:: Running the build daemon.
399 * Application Setup:: Application-specific setup.
402 @node Binary Installation
403 @section Binary Installation
405 @cindex installing Guix from binaries
406 This section describes how to install Guix on an arbitrary system from a
407 self-contained tarball providing binaries for Guix and for all its
408 dependencies. This is often quicker than installing from source, which
409 is described in the next sections. The only requirement is to have
413 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
414 shell installer script}, which automates the download, installation, and
415 initial configuration of Guix. It should be run as the root user.
417 Installing goes along these lines:
421 @cindex downloading Guix binary
422 Download the binary tarball from
423 @indicateurl{ftp://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz},
424 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
425 already running the kernel Linux, and so on.
427 @c The following is somewhat duplicated in ``System Installation''.
428 Make sure to download the associated @file{.sig} file and to verify the
429 authenticity of the tarball against it, along these lines:
432 $ wget ftp://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
433 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
436 If that command fails because you do not have the required public key,
437 then run this command to import it:
440 $ gpg --keyserver pgp.mit.edu --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
444 and rerun the @code{gpg --verify} command.
445 @c end authentication part
448 Now, you need to become the @code{root} user. Depending on your distribution,
449 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
453 # tar --warning=no-timestamp -xf \
454 guix-binary-@value{VERSION}.@var{system}.tar.xz
455 # mv var/guix /var/ && mv gnu /
458 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
459 The latter contains a ready-to-use profile for @code{root} (see next
462 Do @emph{not} unpack the tarball on a working Guix system since that
463 would overwrite its own essential files.
465 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
466 not emit warnings about ``implausibly old time stamps'' (such
467 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
469 They stem from the fact that all the
470 files in the archive have their modification time set to zero (which
471 means January 1st, 1970.) This is done on purpose to make sure the
472 archive content is independent of its creation time, thus making it
476 Make @code{root}'s profile available under @file{~root/.guix-profile}:
479 # ln -sf /var/guix/profiles/per-user/root/guix-profile \
483 Source @file{etc/profile} to augment @code{PATH} and other relevant
484 environment variables:
487 # GUIX_PROFILE="`echo ~root`/.guix-profile" ; \
488 source $GUIX_PROFILE/etc/profile
492 Create the group and user accounts for build users as explained below
493 (@pxref{Build Environment Setup}).
496 Run the daemon, and set it to automatically start on boot.
498 If your host distro uses the systemd init system, this can be achieved
501 @c Versions of systemd that supported symlinked service files are not
502 @c yet widely deployed, so we should suggest that users copy the service
505 @c See this thread for more information:
506 @c http://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
509 # cp ~root/.guix-profile/lib/systemd/system/guix-daemon.service \
511 # systemctl start guix-daemon && systemctl enable guix-daemon
514 If your host distro uses the Upstart init system:
517 # initctl reload-configuration
518 # cp ~root/.guix-profile/lib/upstart/system/guix-daemon.conf /etc/init/
522 Otherwise, you can still start the daemon manually with:
525 # ~root/.guix-profile/bin/guix-daemon --build-users-group=guixbuild
529 Make the @command{guix} command available to other users on the machine,
533 # mkdir -p /usr/local/bin
535 # ln -s /var/guix/profiles/per-user/root/guix-profile/bin/guix
538 It is also a good idea to make the Info version of this manual available
542 # mkdir -p /usr/local/share/info
543 # cd /usr/local/share/info
544 # for i in /var/guix/profiles/per-user/root/guix-profile/share/info/* ;
548 That way, assuming @file{/usr/local/share/info} is in the search path,
549 running @command{info guix} will open this manual (@pxref{Other Info
550 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
554 @cindex substitutes, authorization thereof
555 To use substitutes from @code{hydra.gnu.org} or one of its mirrors
556 (@pxref{Substitutes}), authorize them:
559 # guix archive --authorize < ~root/.guix-profile/share/guix/hydra.gnu.org.pub
563 Each user may need to perform a few additional steps to make their Guix
564 environment ready for use, @pxref{Application Setup}.
567 Voilà, the installation is complete!
569 You can confirm that Guix is working by installing a sample package into
573 # guix package -i hello
576 The @code{guix} package must remain available in @code{root}'s profile,
577 or it would become subject to garbage collection---in which case you
578 would find yourself badly handicapped by the lack of the @command{guix}
579 command. In other words, do not remove @code{guix} by running
580 @code{guix package -r guix}.
582 The binary installation tarball can be (re)produced and verified simply
583 by running the following command in the Guix source tree:
586 make guix-binary.@var{system}.tar.xz
590 ... which, in turn, runs:
593 guix pack -s @var{system} --localstatedir guix
596 @xref{Invoking guix pack}, for more info on this handy tool.
599 @section Requirements
601 This section lists requirements when building Guix from source. The
602 build procedure for Guix is the same as for other GNU software, and is
603 not covered here. Please see the files @file{README} and @file{INSTALL}
604 in the Guix source tree for additional details.
606 GNU Guix depends on the following packages:
609 @item @url{http://gnu.org/software/guile/, GNU Guile}, version 2.0.13 or
610 later, including 2.2.x;
611 @item @url{http://gnupg.org/, GNU libgcrypt};
613 @uref{http://gnutls.org/, GnuTLS}, specifically its Guile bindings
614 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
615 Guile,, gnutls-guile, GnuTLS-Guile});
617 @uref{https://notabug.org/civodul/guile-sqlite3, Guile-SQLite3}, version 0.1.0
620 @c FIXME: Specify a version number once a release has been made.
621 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
623 @item @url{http://zlib.net, zlib};
624 @item @url{http://www.gnu.org/software/make/, GNU Make}.
627 The following dependencies are optional:
632 @url{http://savannah.nongnu.org/projects/guile-json/, Guile-JSON} will
633 allow you to use the @command{guix import pypi} command (@pxref{Invoking
634 guix import}). It is of
635 interest primarily for developers and not for casual users.
638 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
639 Support for build offloading (@pxref{Daemon Offload Setup}) and
640 @command{guix copy} (@pxref{Invoking guix copy}) depends on
641 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
642 version 0.10.2 or later.
645 When @url{http://www.bzip.org, libbz2} is available,
646 @command{guix-daemon} can use it to compress build logs.
649 Unless @code{--disable-daemon} was passed to @command{configure}, the
650 following packages are also needed:
653 @item @url{http://sqlite.org, SQLite 3};
654 @item @url{http://gcc.gnu.org, GCC's g++}, with support for the
658 @cindex state directory
659 When configuring Guix on a system that already has a Guix installation,
660 be sure to specify the same state directory as the existing installation
661 using the @code{--localstatedir} option of the @command{configure}
662 script (@pxref{Directory Variables, @code{localstatedir},, standards,
663 GNU Coding Standards}). The @command{configure} script protects against
664 unintended misconfiguration of @var{localstatedir} so you do not
665 inadvertently corrupt your store (@pxref{The Store}).
667 @cindex Nix, compatibility
668 When a working installation of @url{http://nixos.org/nix/, the Nix package
669 manager} is available, you
670 can instead configure Guix with @code{--disable-daemon}. In that case,
671 Nix replaces the three dependencies above.
673 Guix is compatible with Nix, so it is possible to share the same store
674 between both. To do so, you must pass @command{configure} not only the
675 same @code{--with-store-dir} value, but also the same
676 @code{--localstatedir} value. The latter is essential because it
677 specifies where the database that stores metadata about the store is
678 located, among other things. The default values for Nix are
679 @code{--with-store-dir=/nix/store} and @code{--localstatedir=/nix/var}.
680 Note that @code{--disable-daemon} is not required if
681 your goal is to share the store with Nix.
683 @node Running the Test Suite
684 @section Running the Test Suite
687 After a successful @command{configure} and @code{make} run, it is a good
688 idea to run the test suite. It can help catch issues with the setup or
689 environment, or bugs in Guix itself---and really, reporting test
690 failures is a good way to help improve the software. To run the test
697 Test cases can run in parallel: you can use the @code{-j} option of
698 GNU@tie{}make to speed things up. The first run may take a few minutes
699 on a recent machine; subsequent runs will be faster because the store
700 that is created for test purposes will already have various things in
703 It is also possible to run a subset of the tests by defining the
704 @code{TESTS} makefile variable as in this example:
707 make check TESTS="tests/store.scm tests/cpio.scm"
710 By default, tests results are displayed at a file level. In order to
711 see the details of every individual test cases, it is possible to define
712 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
715 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
718 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
719 @file{test-suite.log} file. Please specify the Guix version being used
720 as well as version numbers of the dependencies (@pxref{Requirements}) in
723 Guix also comes with a whole-system test suite that tests complete
724 GuixSD operating system instances. It can only run on systems where
725 Guix is already installed, using:
732 or, again, by defining @code{TESTS} to select a subset of tests to run:
735 make check-system TESTS="basic mcron"
738 These system tests are defined in the @code{(gnu tests @dots{})}
739 modules. They work by running the operating systems under test with
740 lightweight instrumentation in a virtual machine (VM). They can be
741 computationally intensive or rather cheap, depending on whether
742 substitutes are available for their dependencies (@pxref{Substitutes}).
743 Some of them require a lot of storage space to hold VM images.
745 Again in case of test failures, please send @email{bug-guix@@gnu.org}
748 @node Setting Up the Daemon
749 @section Setting Up the Daemon
752 Operations such as building a package or running the garbage collector
753 are all performed by a specialized process, the @dfn{build daemon}, on
754 behalf of clients. Only the daemon may access the store and its
755 associated database. Thus, any operation that manipulates the store
756 goes through the daemon. For instance, command-line tools such as
757 @command{guix package} and @command{guix build} communicate with the
758 daemon (@i{via} remote procedure calls) to instruct it what to do.
760 The following sections explain how to prepare the build daemon's
761 environment. See also @ref{Substitutes}, for information on how to allow
762 the daemon to download pre-built binaries.
765 * Build Environment Setup:: Preparing the isolated build environment.
766 * Daemon Offload Setup:: Offloading builds to remote machines.
767 * SELinux Support:: Using an SELinux policy for the daemon.
770 @node Build Environment Setup
771 @subsection Build Environment Setup
773 @cindex build environment
774 In a standard multi-user setup, Guix and its daemon---the
775 @command{guix-daemon} program---are installed by the system
776 administrator; @file{/gnu/store} is owned by @code{root} and
777 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
778 Guix tools to build packages or otherwise access the store, and the
779 daemon will do it on their behalf, ensuring that the store is kept in a
780 consistent state, and allowing built packages to be shared among users.
783 When @command{guix-daemon} runs as @code{root}, you may not want package
784 build processes themselves to run as @code{root} too, for obvious
785 security reasons. To avoid that, a special pool of @dfn{build users}
786 should be created for use by build processes started by the daemon.
787 These build users need not have a shell and a home directory: they will
788 just be used when the daemon drops @code{root} privileges in build
789 processes. Having several such users allows the daemon to launch
790 distinct build processes under separate UIDs, which guarantees that they
791 do not interfere with each other---an essential feature since builds are
792 regarded as pure functions (@pxref{Introduction}).
794 On a GNU/Linux system, a build user pool may be created like this (using
795 Bash syntax and the @code{shadow} commands):
797 @c See http://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
798 @c for why `-G' is needed.
800 # groupadd --system guixbuild
801 # for i in `seq -w 1 10`;
803 useradd -g guixbuild -G guixbuild \
804 -d /var/empty -s `which nologin` \
805 -c "Guix build user $i" --system \
811 The number of build users determines how many build jobs may run in
812 parallel, as specified by the @option{--max-jobs} option
813 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
814 @command{guix system vm} and related commands, you may need to add the
815 build users to the @code{kvm} group so they can access @file{/dev/kvm},
816 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
817 (@pxref{Invoking guix system}).
819 The @code{guix-daemon} program may then be run as @code{root} with the
820 following command@footnote{If your machine uses the systemd init system,
821 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
822 file in @file{/etc/systemd/system} will ensure that
823 @command{guix-daemon} is automatically started. Similarly, if your
824 machine uses the Upstart init system, drop the
825 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
826 file in @file{/etc/init}.}:
829 # guix-daemon --build-users-group=guixbuild
834 This way, the daemon starts build processes in a chroot, under one of
835 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
836 environment contains nothing but:
838 @c Keep this list in sync with libstore/build.cc! -----------------------
841 a minimal @code{/dev} directory, created mostly independently from the
842 host @code{/dev}@footnote{``Mostly'', because while the set of files
843 that appear in the chroot's @code{/dev} is fixed, most of these files
844 can only be created if the host has them.};
847 the @code{/proc} directory; it only shows the processes of the container
848 since a separate PID name space is used;
851 @file{/etc/passwd} with an entry for the current user and an entry for
855 @file{/etc/group} with an entry for the user's group;
858 @file{/etc/hosts} with an entry that maps @code{localhost} to
862 a writable @file{/tmp} directory.
865 You can influence the directory where the daemon stores build trees
866 @i{via} the @code{TMPDIR} environment variable. However, the build tree
867 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
868 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
869 This way, the value of @code{TMPDIR} does not leak inside build
870 environments, which avoids discrepancies in cases where build processes
871 capture the name of their build tree.
874 The daemon also honors the @code{http_proxy} environment variable for
875 HTTP downloads it performs, be it for fixed-output derivations
876 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
878 If you are installing Guix as an unprivileged user, it is still possible
879 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
880 However, build processes will not be isolated from one another, and not
881 from the rest of the system. Thus, build processes may interfere with
882 each other, and may access programs, libraries, and other files
883 available on the system---making it much harder to view them as
884 @emph{pure} functions.
887 @node Daemon Offload Setup
888 @subsection Using the Offload Facility
892 When desired, the build daemon can @dfn{offload} derivation builds to
893 other machines running Guix, using the @code{offload} @dfn{build
894 hook}@footnote{This feature is available only when
895 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
897 feature is enabled, a list of user-specified build machines is read from
898 @file{/etc/guix/machines.scm}; every time a build is requested, for
899 instance via @code{guix build}, the daemon attempts to offload it to one
900 of the machines that satisfy the constraints of the derivation, in
901 particular its system type---e.g., @file{x86_64-linux}. Missing
902 prerequisites for the build are copied over SSH to the target machine,
903 which then proceeds with the build; upon success the output(s) of the
904 build are copied back to the initial machine.
906 The @file{/etc/guix/machines.scm} file typically looks like this:
910 (name "eightysix.example.org")
911 (system "x86_64-linux")
912 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
914 (speed 2.)) ;incredibly fast!
917 (name "meeps.example.org")
918 (system "mips64el-linux")
919 (host-key "ssh-rsa AAAAB3Nza@dots{}")
922 (string-append (getenv "HOME")
923 "/.ssh/identity-for-guix"))))
927 In the example above we specify a list of two build machines, one for
928 the @code{x86_64} architecture and one for the @code{mips64el}
931 In fact, this file is---not surprisingly!---a Scheme file that is
932 evaluated when the @code{offload} hook is started. Its return value
933 must be a list of @code{build-machine} objects. While this example
934 shows a fixed list of build machines, one could imagine, say, using
935 DNS-SD to return a list of potential build machines discovered in the
936 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
937 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
940 @deftp {Data Type} build-machine
941 This data type represents build machines to which the daemon may offload
942 builds. The important fields are:
947 The host name of the remote machine.
950 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
953 The user account to use when connecting to the remote machine over SSH.
954 Note that the SSH key pair must @emph{not} be passphrase-protected, to
955 allow non-interactive logins.
958 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
959 This is used to authenticate the machine when we connect to it. It is a
960 long string that looks like this:
963 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
966 If the machine is running the OpenSSH daemon, @command{sshd}, the host
967 key can be found in a file such as
968 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
970 If the machine is running the SSH daemon of GNU@tie{}lsh,
971 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
972 similar file. It can be converted to the OpenSSH format using
973 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
976 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
977 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
982 A number of optional fields may be specified:
986 @item @code{port} (default: @code{22})
987 Port number of SSH server on the machine.
989 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
990 The SSH private key file to use when connecting to the machine, in
991 OpenSSH format. This key must not be protected with a passphrase.
993 Note that the default value is the private key @emph{of the root
994 account}. Make sure it exists if you use the default.
996 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
997 @itemx @code{compression-level} (default: @code{3})
998 The SSH-level compression methods and compression level requested.
1000 Note that offloading relies on SSH compression to reduce bandwidth usage
1001 when transferring files to and from build machines.
1003 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1004 File name of the Unix-domain socket @command{guix-daemon} is listening
1007 @item @code{parallel-builds} (default: @code{1})
1008 The number of builds that may run in parallel on the machine.
1010 @item @code{speed} (default: @code{1.0})
1011 A ``relative speed factor''. The offload scheduler will tend to prefer
1012 machines with a higher speed factor.
1014 @item @code{features} (default: @code{'()})
1015 A list of strings denoting specific features supported by the machine.
1016 An example is @code{"kvm"} for machines that have the KVM Linux modules
1017 and corresponding hardware support. Derivations can request features by
1018 name, and they will be scheduled on matching build machines.
1023 The @code{guile} command must be in the search path on the build
1024 machines. In addition, the Guix modules must be in
1025 @code{$GUILE_LOAD_PATH} on the build machine---you can check whether
1026 this is the case by running:
1029 ssh build-machine guile -c "'(use-modules (guix config))'"
1032 There is one last thing to do once @file{machines.scm} is in place. As
1033 explained above, when offloading, files are transferred back and forth
1034 between the machine stores. For this to work, you first need to
1035 generate a key pair on each machine to allow the daemon to export signed
1036 archives of files from the store (@pxref{Invoking guix archive}):
1039 # guix archive --generate-key
1043 Each build machine must authorize the key of the master machine so that
1044 it accepts store items it receives from the master:
1047 # guix archive --authorize < master-public-key.txt
1051 Likewise, the master machine must authorize the key of each build machine.
1053 All the fuss with keys is here to express pairwise mutual trust
1054 relations between the master and the build machines. Concretely, when
1055 the master receives files from a build machine (and @i{vice versa}), its
1056 build daemon can make sure they are genuine, have not been tampered
1057 with, and that they are signed by an authorized key.
1059 @cindex offload test
1060 To test whether your setup is operational, run this command on the
1067 This will attempt to connect to each of the build machines specified in
1068 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1069 available on each machine, attempt to export to the machine and import
1070 from it, and report any error in the process.
1072 If you want to test a different machine file, just specify it on the
1076 # guix offload test machines-qualif.scm
1079 Last, you can test the subset of the machines whose name matches a
1080 regular expression like this:
1083 # guix offload test machines.scm '\.gnu\.org$'
1086 @cindex offload status
1087 To display the current load of all build hosts, run this command on the
1091 # guix offload status
1095 @node SELinux Support
1096 @subsection SELinux Support
1098 @cindex SELinux, daemon policy
1099 @cindex mandatory access control, SELinux
1100 @cindex security, guix-daemon
1101 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1102 can be installed on a system where SELinux is enabled, in order to label
1103 Guix files and to specify the expected behavior of the daemon. Since
1104 GuixSD does not provide an SELinux base policy, the daemon policy cannot
1107 @subsubsection Installing the SELinux policy
1108 @cindex SELinux, policy installation
1109 To install the policy run this command as root:
1112 semodule -i etc/guix-daemon.cil
1115 Then relabel the file system with @code{restorecon} or by a different
1116 mechanism provided by your system.
1118 Once the policy is installed, the file system has been relabeled, and
1119 the daemon has been restarted, it should be running in the
1120 @code{guix_daemon_t} context. You can confirm this with the following
1124 ps -Zax | grep guix-daemon
1127 Monitor the SELinux log files as you run a command like @code{guix build
1128 hello} to convince yourself that SELinux permits all necessary
1131 @subsubsection Limitations
1132 @cindex SELinux, limitations
1134 This policy is not perfect. Here is a list of limitations or quirks
1135 that should be considered when deploying the provided SELinux policy for
1140 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1141 operations involve contexts that have anything to do with
1142 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1143 but it would be preferrable to define socket rules for only this label.
1146 @code{guix gc} cannot access arbitrary links to profiles. By design,
1147 the file label of the destination of a symlink is independent of the
1148 file label of the link itself. Although all profiles under
1149 $localstatedir are labelled, the links to these profiles inherit the
1150 label of the directory they are in. For links in the user’s home
1151 directory this will be @code{user_home_t}. But for links from the root
1152 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1153 directory, etc, this won’t work. @code{guix gc} would be prevented from
1154 reading and following these links.
1157 The daemon’s feature to listen for TCP connections might no longer work.
1158 This might require extra rules, because SELinux treats network sockets
1159 differently from files.
1162 Currently all files with a name matching the regular expression
1163 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1164 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1165 that name in any profile would be permitted to run in the
1166 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1167 build a package that provides this executable and convince a user to
1168 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1169 At that point SELinux could not prevent it from accessing files that are
1170 allowed for processes in that domain.
1172 We could generate a much more restrictive policy at installation time,
1173 so that only the @emph{exact} file name of the currently installed
1174 @code{guix-daemon} executable would be labelled with
1175 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1176 The downside is that root would have to install or upgrade the policy at
1177 installation time whenever the Guix package that provides the
1178 effectively running @code{guix-daemon} executable is upgraded.
1181 @node Invoking guix-daemon
1182 @section Invoking @command{guix-daemon}
1184 The @command{guix-daemon} program implements all the functionality to
1185 access the store. This includes launching build processes, running the
1186 garbage collector, querying the availability of a build result, etc. It
1187 is normally run as @code{root} like this:
1190 # guix-daemon --build-users-group=guixbuild
1194 For details on how to set it up, @pxref{Setting Up the Daemon}.
1197 @cindex container, build environment
1198 @cindex build environment
1199 @cindex reproducible builds
1200 By default, @command{guix-daemon} launches build processes under
1201 different UIDs, taken from the build group specified with
1202 @code{--build-users-group}. In addition, each build process is run in a
1203 chroot environment that only contains the subset of the store that the
1204 build process depends on, as specified by its derivation
1205 (@pxref{Programming Interface, derivation}), plus a set of specific
1206 system directories. By default, the latter contains @file{/dev} and
1207 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1208 @dfn{container}: in addition to having its own file system tree, it has
1209 a separate mount name space, its own PID name space, network name space,
1210 etc. This helps achieve reproducible builds (@pxref{Features}).
1212 When the daemon performs a build on behalf of the user, it creates a
1213 build directory under @file{/tmp} or under the directory specified by
1214 its @code{TMPDIR} environment variable; this directory is shared with
1215 the container for the duration of the build. Be aware that using a
1216 directory other than @file{/tmp} can affect build results---for example,
1217 with a longer directory name, a build process that uses Unix-domain
1218 sockets might hit the name length limitation for @code{sun_path}, which
1219 it would otherwise not hit.
1221 The build directory is automatically deleted upon completion, unless the
1222 build failed and the client specified @option{--keep-failed}
1223 (@pxref{Invoking guix build, @option{--keep-failed}}).
1225 The following command-line options are supported:
1228 @item --build-users-group=@var{group}
1229 Take users from @var{group} to run build processes (@pxref{Setting Up
1230 the Daemon, build users}).
1232 @item --no-substitutes
1234 Do not use substitutes for build products. That is, always build things
1235 locally instead of allowing downloads of pre-built binaries
1236 (@pxref{Substitutes}).
1238 When the daemon runs with @code{--no-substitutes}, clients can still
1239 explicitly enable substitution @i{via} the @code{set-build-options}
1240 remote procedure call (@pxref{The Store}).
1242 @item --substitute-urls=@var{urls}
1243 @anchor{daemon-substitute-urls}
1244 Consider @var{urls} the default whitespace-separated list of substitute
1245 source URLs. When this option is omitted,
1246 @indicateurl{https://mirror.hydra.gnu.org https://hydra.gnu.org} is used
1247 (@code{mirror.hydra.gnu.org} is a mirror of @code{hydra.gnu.org}).
1249 This means that substitutes may be downloaded from @var{urls}, as long
1250 as they are signed by a trusted signature (@pxref{Substitutes}).
1253 @item --no-build-hook
1254 Do not use the @dfn{build hook}.
1256 The build hook is a helper program that the daemon can start and to
1257 which it submits build requests. This mechanism is used to offload
1258 builds to other machines (@pxref{Daemon Offload Setup}).
1260 @item --cache-failures
1261 Cache build failures. By default, only successful builds are cached.
1263 When this option is used, @command{guix gc --list-failures} can be used
1264 to query the set of store items marked as failed; @command{guix gc
1265 --clear-failures} removes store items from the set of cached failures.
1266 @xref{Invoking guix gc}.
1268 @item --cores=@var{n}
1270 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1273 The default value is @code{0}, but it may be overridden by clients, such
1274 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1277 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1278 in the build process, which can then use it to exploit internal
1279 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1281 @item --max-jobs=@var{n}
1283 Allow at most @var{n} build jobs in parallel. The default value is
1284 @code{1}. Setting it to @code{0} means that no builds will be performed
1285 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1286 Setup}), or simply fail.
1288 @item --max-silent-time=@var{seconds}
1289 When the build or substitution process remains silent for more than
1290 @var{seconds}, terminate it and report a build failure.
1292 The default value is @code{0}, which disables the timeout.
1294 The value specified here can be overridden by clients (@pxref{Common
1295 Build Options, @code{--max-silent-time}}).
1297 @item --timeout=@var{seconds}
1298 Likewise, when the build or substitution process lasts for more than
1299 @var{seconds}, terminate it and report a build failure.
1301 The default value is @code{0}, which disables the timeout.
1303 The value specified here can be overridden by clients (@pxref{Common
1304 Build Options, @code{--timeout}}).
1306 @item --rounds=@var{N}
1307 Build each derivation @var{n} times in a row, and raise an error if
1308 consecutive build results are not bit-for-bit identical. Note that this
1309 setting can be overridden by clients such as @command{guix build}
1310 (@pxref{Invoking guix build}).
1312 When used in conjunction with @option{--keep-failed}, the differing
1313 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1314 This makes it easy to look for differences between the two results.
1317 Produce debugging output.
1319 This is useful to debug daemon start-up issues, but then it may be
1320 overridden by clients, for example the @code{--verbosity} option of
1321 @command{guix build} (@pxref{Invoking guix build}).
1323 @item --chroot-directory=@var{dir}
1324 Add @var{dir} to the build chroot.
1326 Doing this may change the result of build processes---for instance if
1327 they use optional dependencies found in @var{dir} when it is available,
1328 and not otherwise. For that reason, it is not recommended to do so.
1329 Instead, make sure that each derivation declares all the inputs that it
1332 @item --disable-chroot
1333 Disable chroot builds.
1335 Using this option is not recommended since, again, it would allow build
1336 processes to gain access to undeclared dependencies. It is necessary,
1337 though, when @command{guix-daemon} is running under an unprivileged user
1340 @item --log-compression=@var{type}
1341 Compress build logs according to @var{type}, one of @code{gzip},
1342 @code{bzip2}, or @code{none}.
1344 Unless @code{--lose-logs} is used, all the build logs are kept in the
1345 @var{localstatedir}. To save space, the daemon automatically compresses
1346 them with bzip2 by default.
1348 @item --disable-deduplication
1349 @cindex deduplication
1350 Disable automatic file ``deduplication'' in the store.
1352 By default, files added to the store are automatically ``deduplicated'':
1353 if a newly added file is identical to another one found in the store,
1354 the daemon makes the new file a hard link to the other file. This can
1355 noticeably reduce disk usage, at the expense of slightly increased
1356 input/output load at the end of a build process. This option disables
1359 @item --gc-keep-outputs[=yes|no]
1360 Tell whether the garbage collector (GC) must keep outputs of live
1364 @cindex garbage collector roots
1365 When set to ``yes'', the GC will keep the outputs of any live derivation
1366 available in the store---the @code{.drv} files. The default is ``no'',
1367 meaning that derivation outputs are kept only if they are GC roots.
1368 @xref{Invoking guix gc}, for more on GC roots.
1370 @item --gc-keep-derivations[=yes|no]
1371 Tell whether the garbage collector (GC) must keep derivations
1372 corresponding to live outputs.
1374 When set to ``yes'', as is the case by default, the GC keeps
1375 derivations---i.e., @code{.drv} files---as long as at least one of their
1376 outputs is live. This allows users to keep track of the origins of
1377 items in their store. Setting it to ``no'' saves a bit of disk space.
1379 Note that when both @code{--gc-keep-derivations} and
1380 @code{--gc-keep-outputs} are used, the effect is to keep all the build
1381 prerequisites (the sources, compiler, libraries, and other build-time
1382 tools) of live objects in the store, regardless of whether these
1383 prerequisites are live. This is convenient for developers since it
1384 saves rebuilds or downloads.
1386 @item --impersonate-linux-2.6
1387 On Linux-based systems, impersonate Linux 2.6. This means that the
1388 kernel's @code{uname} system call will report 2.6 as the release number.
1390 This might be helpful to build programs that (usually wrongfully) depend
1391 on the kernel version number.
1394 Do not keep build logs. By default they are kept under
1395 @code{@var{localstatedir}/guix/log}.
1397 @item --system=@var{system}
1398 Assume @var{system} as the current system type. By default it is the
1399 architecture/kernel pair found at configure time, such as
1400 @code{x86_64-linux}.
1402 @item --listen=@var{endpoint}
1403 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1404 as the file name of a Unix-domain socket if it starts with
1405 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1406 host name or host name and port to listen to. Here are a few examples:
1409 @item --listen=/gnu/var/daemon
1410 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1411 creating it if needed.
1413 @item --listen=localhost
1414 @cindex daemon, remote access
1415 @cindex remote access to the daemon
1416 @cindex daemon, cluster setup
1417 @cindex clusters, daemon setup
1418 Listen for TCP connections on the network interface corresponding to
1419 @code{localhost}, on port 44146.
1421 @item --listen=128.0.0.42:1234
1422 Listen for TCP connections on the network interface corresponding to
1423 @code{128.0.0.42}, on port 1234.
1426 This option can be repeated multiple times, in which case
1427 @command{guix-daemon} accepts connections on all the specified
1428 endpoints. Users can tell client commands what endpoint to connect to
1429 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1430 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1433 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1434 @code{--listen=@var{host}} is suitable on local networks, such as
1435 clusters, where only trusted nodes may connect to the build daemon. In
1436 other cases where remote access to the daemon is needed, we recommend
1437 using Unix-domain sockets along with SSH.
1440 When @code{--listen} is omitted, @command{guix-daemon} listens for
1441 connections on the Unix-domain socket located at
1442 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1446 @node Application Setup
1447 @section Application Setup
1449 @cindex foreign distro
1450 When using Guix on top of GNU/Linux distribution other than GuixSD---a
1451 so-called @dfn{foreign distro}---a few additional steps are needed to
1452 get everything in place. Here are some of them.
1456 @anchor{locales-and-locpath}
1457 @cindex locales, when not on GuixSD
1459 @vindex GUIX_LOCPATH
1460 Packages installed @i{via} Guix will not use the locale data of the
1461 host system. Instead, you must first install one of the locale packages
1462 available with Guix and then define the @code{GUIX_LOCPATH} environment
1466 $ guix package -i glibc-locales
1467 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1470 Note that the @code{glibc-locales} package contains data for all the
1471 locales supported by the GNU@tie{}libc and weighs in at around
1472 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1473 limited to a few UTF-8 locales.
1475 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1476 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1477 Manual}). There are two important differences though:
1481 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1482 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1483 to make sure the programs of the foreign distro will not end up loading
1484 incompatible locale data.
1487 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1488 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1489 should your Guix profile contain a mixture of programs linked against
1490 different libc version, each libc version will only try to load locale
1491 data in the right format.
1494 This is important because the locale data format used by different libc
1495 versions may be incompatible.
1497 @subsection Name Service Switch
1499 @cindex name service switch, glibc
1500 @cindex NSS (name service switch), glibc
1501 @cindex nscd (name service caching daemon)
1502 @cindex name service caching daemon (nscd)
1503 When using Guix on a foreign distro, we @emph{strongly recommend} that
1504 the system run the GNU C library's @dfn{name service cache daemon},
1505 @command{nscd}, which should be listening on the
1506 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1507 installed with Guix may fail to look up host names or user accounts, or
1508 may even crash. The next paragraphs explain why.
1510 @cindex @file{nsswitch.conf}
1511 The GNU C library implements a @dfn{name service switch} (NSS), which is
1512 an extensible mechanism for ``name lookups'' in general: host name
1513 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1514 The GNU C Library Reference Manual}).
1516 @cindex Network information service (NIS)
1517 @cindex NIS (Network information service)
1518 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1519 lookup implementations: for example, the @code{nss-mdns} plugin allow
1520 resolution of @code{.local} host names, the @code{nis} plugin allows
1521 user account lookup using the Network information service (NIS), and so
1522 on. These extra ``lookup services'' are configured system-wide in
1523 @file{/etc/nsswitch.conf}, and all the programs running on the system
1524 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1527 When they perform a name lookup---for instance by calling the
1528 @code{getaddrinfo} function in C---applications first try to connect to
1529 the nscd; on success, nscd performs name lookups on their behalf. If
1530 the nscd is not running, then they perform the name lookup by
1531 themselves, by loading the name lookup services into their own address
1532 space and running it. These name lookup services---the
1533 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1534 the host system's C library, rather than from the C library the
1535 application is linked against (the C library coming from Guix).
1537 And this is where the problem is: if your application is linked against
1538 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1539 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1540 likely crash or have its name lookups fail unexpectedly.
1542 Running @command{nscd} on the system, among other advantages, eliminates
1543 this binary incompatibility problem because those @code{libnss_*.so}
1544 files are loaded in the @command{nscd} process, not in applications
1547 @subsection X11 Fonts
1550 The majority of graphical applications use Fontconfig to locate and
1551 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1552 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1553 by default. Thus, to allow graphical applications installed with Guix
1554 to display fonts, you have to install fonts with Guix as well.
1555 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1556 @code{font-gnu-freefont-ttf}.
1558 To display text written in Chinese languages, Japanese, or Korean in
1559 graphical applications, consider installing
1560 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1561 has multiple outputs, one per language family (@pxref{Packages with
1562 Multiple Outputs}). For instance, the following command installs fonts
1563 for Chinese languages:
1566 guix package -i font-adobe-source-han-sans:cn
1569 @cindex @code{xterm}
1570 Older programs such as @command{xterm} do not use Fontconfig and instead
1571 rely on server-side font rendering. Such programs require to specify a
1572 full name of a font using XLFD (X Logical Font Description), like this:
1575 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1578 To be able to use such full names for the TrueType fonts installed in
1579 your Guix profile, you need to extend the font path of the X server:
1581 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1582 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1584 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1587 @cindex @code{xlsfonts}
1588 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1589 to make sure your TrueType fonts are listed there.
1591 @cindex @code{fc-cache}
1593 After installing fonts you may have to refresh the font cache to use
1594 them in applications. The same applies when applications installed via
1595 Guix do not seem to find fonts. To force rebuilding of the font cache
1596 run @code{fc-cache -f}. The @code{fc-cache} command is provided by the
1597 @code{fontconfig} package.
1599 @subsection X.509 Certificates
1601 @cindex @code{nss-certs}
1602 The @code{nss-certs} package provides X.509 certificates, which allow
1603 programs to authenticate Web servers accessed over HTTPS.
1605 When using Guix on a foreign distro, you can install this package and
1606 define the relevant environment variables so that packages know where to
1607 look for certificates. @xref{X.509 Certificates}, for detailed
1610 @subsection Emacs Packages
1612 @cindex @code{emacs}
1613 When you install Emacs packages with Guix, the elisp files may be placed
1614 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1616 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1617 directory exists because potentially there may exist thousands of Emacs
1618 packages and storing all their files in a single directory may not be
1619 reliable (because of name conflicts). So we think using a separate
1620 directory for each package is a good idea. It is very similar to how
1621 the Emacs package system organizes the file structure (@pxref{Package
1622 Files,,, emacs, The GNU Emacs Manual}).
1624 By default, Emacs (installed with Guix) ``knows'' where these packages
1625 are placed, so you do not need to perform any configuration. If, for
1626 some reason, you want to avoid auto-loading Emacs packages installed
1627 with Guix, you can do so by running Emacs with @code{--no-site-file}
1628 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1630 @subsection The GCC toolchain
1635 Guix offers individual compiler packages such as @code{gcc} but if you
1636 are in need of a complete toolchain for compiling and linking source
1637 code what you really want is the @code{gcc-toolchain} package. This
1638 package provides a complete GCC toolchain for C/C++ development,
1639 including GCC itself, the GNU C Library (headers and binaries, plus
1640 debugging symbols in the @code{debug} output), Binutils, and a linker
1643 @cindex attempt to use impure library, error message
1645 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1646 passed to the linker, add corresponding @code{-rpath} arguments, and
1647 invoke the actual linker with this new set of arguments. By default,
1648 the linker wrapper refuses to link to libraries outside the store to
1649 ensure ``purity''. This can be annoying when using the toolchain to
1650 link with local libraries. To allow references to libraries outside the
1651 store you need to define the environment variable
1652 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES}.
1656 @c *********************************************************************
1657 @node Package Management
1658 @chapter Package Management
1661 The purpose of GNU Guix is to allow users to easily install, upgrade, and
1662 remove software packages, without having to know about their build
1663 procedures or dependencies. Guix also goes beyond this obvious set of
1666 This chapter describes the main features of Guix, as well as the
1667 package management tools it provides. Along with the command-line
1668 interface described below (@pxref{Invoking guix package, @code{guix
1669 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
1670 emacs-guix, The Emacs-Guix Reference Manual}), after installing
1671 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
1675 guix package -i emacs-guix
1679 * Features:: How Guix will make your life brighter.
1680 * Invoking guix package:: Package installation, removal, etc.
1681 * Substitutes:: Downloading pre-built binaries.
1682 * Packages with Multiple Outputs:: Single source package, multiple outputs.
1683 * Invoking guix gc:: Running the garbage collector.
1684 * Invoking guix pull:: Fetching the latest Guix and distribution.
1685 * Invoking guix pack:: Creating software bundles.
1686 * Invoking guix archive:: Exporting and importing store files.
1692 When using Guix, each package ends up in the @dfn{package store}, in its
1693 own directory---something that resembles
1694 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
1696 Instead of referring to these directories, users have their own
1697 @dfn{profile}, which points to the packages that they actually want to
1698 use. These profiles are stored within each user's home directory, at
1699 @code{$HOME/.guix-profile}.
1701 For example, @code{alice} installs GCC 4.7.2. As a result,
1702 @file{/home/alice/.guix-profile/bin/gcc} points to
1703 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
1704 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
1705 simply continues to point to
1706 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
1707 coexist on the same system without any interference.
1709 The @command{guix package} command is the central tool to manage
1710 packages (@pxref{Invoking guix package}). It operates on the per-user
1711 profiles, and can be used @emph{with normal user privileges}.
1713 @cindex transactions
1714 The command provides the obvious install, remove, and upgrade
1715 operations. Each invocation is actually a @emph{transaction}: either
1716 the specified operation succeeds, or nothing happens. Thus, if the
1717 @command{guix package} process is terminated during the transaction,
1718 or if a power outage occurs during the transaction, then the user's
1719 profile remains in its previous state, and remains usable.
1721 In addition, any package transaction may be @emph{rolled back}. So, if,
1722 for example, an upgrade installs a new version of a package that turns
1723 out to have a serious bug, users may roll back to the previous instance
1724 of their profile, which was known to work well. Similarly, the global
1725 system configuration on GuixSD is subject to
1726 transactional upgrades and roll-back
1727 (@pxref{Using the Configuration System}).
1729 All packages in the package store may be @emph{garbage-collected}.
1730 Guix can determine which packages are still referenced by user
1731 profiles, and remove those that are provably no longer referenced
1732 (@pxref{Invoking guix gc}). Users may also explicitly remove old
1733 generations of their profile so that the packages they refer to can be
1736 @cindex reproducibility
1737 @cindex reproducible builds
1738 Finally, Guix takes a @dfn{purely functional} approach to package
1739 management, as described in the introduction (@pxref{Introduction}).
1740 Each @file{/gnu/store} package directory name contains a hash of all the
1741 inputs that were used to build that package---compiler, libraries, build
1742 scripts, etc. This direct correspondence allows users to make sure a
1743 given package installation matches the current state of their
1744 distribution. It also helps maximize @dfn{build reproducibility}:
1745 thanks to the isolated build environments that are used, a given build
1746 is likely to yield bit-identical files when performed on different
1747 machines (@pxref{Invoking guix-daemon, container}).
1750 This foundation allows Guix to support @dfn{transparent binary/source
1751 deployment}. When a pre-built binary for a @file{/gnu/store} item is
1752 available from an external source---a @dfn{substitute}, Guix just
1753 downloads it and unpacks it;
1754 otherwise, it builds the package from source, locally
1755 (@pxref{Substitutes}). Because build results are usually bit-for-bit
1756 reproducible, users do not have to trust servers that provide
1757 substitutes: they can force a local build and @emph{challenge} providers
1758 (@pxref{Invoking guix challenge}).
1760 Control over the build environment is a feature that is also useful for
1761 developers. The @command{guix environment} command allows developers of
1762 a package to quickly set up the right development environment for their
1763 package, without having to manually install the dependencies of the
1764 package into their profile (@pxref{Invoking guix environment}).
1766 @node Invoking guix package
1767 @section Invoking @command{guix package}
1769 @cindex installing packages
1770 @cindex removing packages
1771 @cindex package installation
1772 @cindex package removal
1773 The @command{guix package} command is the tool that allows users to
1774 install, upgrade, and remove packages, as well as rolling back to
1775 previous configurations. It operates only on the user's own profile,
1776 and works with normal user privileges (@pxref{Features}). Its syntax
1780 guix package @var{options}
1782 @cindex transactions
1783 Primarily, @var{options} specifies the operations to be performed during
1784 the transaction. Upon completion, a new profile is created, but
1785 previous @dfn{generations} of the profile remain available, should the user
1788 For example, to remove @code{lua} and install @code{guile} and
1789 @code{guile-cairo} in a single transaction:
1792 guix package -r lua -i guile guile-cairo
1795 @command{guix package} also supports a @dfn{declarative approach}
1796 whereby the user specifies the exact set of packages to be available and
1797 passes it @i{via} the @option{--manifest} option
1798 (@pxref{profile-manifest, @option{--manifest}}).
1801 For each user, a symlink to the user's default profile is automatically
1802 created in @file{$HOME/.guix-profile}. This symlink always points to the
1803 current generation of the user's default profile. Thus, users can add
1804 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
1805 variable, and so on.
1806 @cindex search paths
1807 If you are not using the Guix System Distribution, consider adding the
1808 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
1809 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
1810 shells get all the right environment variable definitions:
1813 GUIX_PROFILE="$HOME/.guix-profile" ; \
1814 source "$HOME/.guix-profile/etc/profile"
1817 In a multi-user setup, user profiles are stored in a place registered as
1818 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
1819 to (@pxref{Invoking guix gc}). That directory is normally
1820 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
1821 @var{localstatedir} is the value passed to @code{configure} as
1822 @code{--localstatedir}, and @var{user} is the user name. The
1823 @file{per-user} directory is created when @command{guix-daemon} is
1824 started, and the @var{user} sub-directory is created by @command{guix
1827 The @var{options} can be among the following:
1831 @item --install=@var{package} @dots{}
1832 @itemx -i @var{package} @dots{}
1833 Install the specified @var{package}s.
1835 Each @var{package} may specify either a simple package name, such as
1836 @code{guile}, or a package name followed by an at-sign and version number,
1837 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
1838 case, the newest version prefixed by @code{1.8} is selected.)
1840 If no version number is specified, the
1841 newest available version will be selected. In addition, @var{package}
1842 may contain a colon, followed by the name of one of the outputs of the
1843 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
1844 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
1845 name (and optionally version) are searched for among the GNU
1846 distribution modules (@pxref{Package Modules}).
1848 @cindex propagated inputs
1849 Sometimes packages have @dfn{propagated inputs}: these are dependencies
1850 that automatically get installed along with the required package
1851 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
1852 @code{package} objects}, for information about propagated inputs in
1853 package definitions).
1855 @anchor{package-cmd-propagated-inputs}
1856 An example is the GNU MPC library: its C header files refer to those of
1857 the GNU MPFR library, which in turn refer to those of the GMP library.
1858 Thus, when installing MPC, the MPFR and GMP libraries also get installed
1859 in the profile; removing MPC also removes MPFR and GMP---unless they had
1860 also been explicitly installed by the user.
1862 Besides, packages sometimes rely on the definition of environment
1863 variables for their search paths (see explanation of
1864 @code{--search-paths} below). Any missing or possibly incorrect
1865 environment variable definitions are reported here.
1867 @item --install-from-expression=@var{exp}
1869 Install the package @var{exp} evaluates to.
1871 @var{exp} must be a Scheme expression that evaluates to a
1872 @code{<package>} object. This option is notably useful to disambiguate
1873 between same-named variants of a package, with expressions such as
1874 @code{(@@ (gnu packages base) guile-final)}.
1876 Note that this option installs the first output of the specified
1877 package, which may be insufficient when needing a specific output of a
1878 multiple-output package.
1880 @item --install-from-file=@var{file}
1881 @itemx -f @var{file}
1882 Install the package that the code within @var{file} evaluates to.
1884 As an example, @var{file} might contain a definition like this
1885 (@pxref{Defining Packages}):
1888 @verbatiminclude package-hello.scm
1891 Developers may find it useful to include such a @file{guix.scm} file
1892 in the root of their project source tree that can be used to test
1893 development snapshots and create reproducible development environments
1894 (@pxref{Invoking guix environment}).
1896 @item --remove=@var{package} @dots{}
1897 @itemx -r @var{package} @dots{}
1898 Remove the specified @var{package}s.
1900 As for @code{--install}, each @var{package} may specify a version number
1901 and/or output name in addition to the package name. For instance,
1902 @code{-r glibc:debug} would remove the @code{debug} output of
1905 @item --upgrade[=@var{regexp} @dots{}]
1906 @itemx -u [@var{regexp} @dots{}]
1907 @cindex upgrading packages
1908 Upgrade all the installed packages. If one or more @var{regexp}s are
1909 specified, upgrade only installed packages whose name matches a
1910 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
1912 Note that this upgrades package to the latest version of packages found
1913 in the distribution currently installed. To update your distribution,
1914 you should regularly run @command{guix pull} (@pxref{Invoking guix
1917 @item --do-not-upgrade[=@var{regexp} @dots{}]
1918 When used together with the @code{--upgrade} option, do @emph{not}
1919 upgrade any packages whose name matches a @var{regexp}. For example, to
1920 upgrade all packages in the current profile except those containing the
1921 substring ``emacs'':
1924 $ guix package --upgrade . --do-not-upgrade emacs
1927 @item @anchor{profile-manifest}--manifest=@var{file}
1928 @itemx -m @var{file}
1929 @cindex profile declaration
1930 @cindex profile manifest
1931 Create a new generation of the profile from the manifest object
1932 returned by the Scheme code in @var{file}.
1934 This allows you to @emph{declare} the profile's contents rather than
1935 constructing it through a sequence of @code{--install} and similar
1936 commands. The advantage is that @var{file} can be put under version
1937 control, copied to different machines to reproduce the same profile, and
1940 @c FIXME: Add reference to (guix profile) documentation when available.
1941 @var{file} must return a @dfn{manifest} object, which is roughly a list
1944 @findex packages->manifest
1946 (use-package-modules guile emacs)
1951 ;; Use a specific package output.
1952 (list guile-2.0 "debug")))
1955 @findex specifications->manifest
1956 In this example we have to know which modules define the @code{emacs}
1957 and @code{guile-2.0} variables to provide the right
1958 @code{use-package-modules} line, which can be cumbersome. We can
1959 instead provide regular package specifications and let
1960 @code{specifications->manifest} look up the corresponding package
1964 (specifications->manifest
1965 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
1969 @cindex rolling back
1970 @cindex undoing transactions
1971 @cindex transactions, undoing
1972 Roll back to the previous @dfn{generation} of the profile---i.e., undo
1973 the last transaction.
1975 When combined with options such as @code{--install}, roll back occurs
1976 before any other actions.
1978 When rolling back from the first generation that actually contains
1979 installed packages, the profile is made to point to the @dfn{zeroth
1980 generation}, which contains no files apart from its own metadata.
1982 After having rolled back, installing, removing, or upgrading packages
1983 overwrites previous future generations. Thus, the history of the
1984 generations in a profile is always linear.
1986 @item --switch-generation=@var{pattern}
1987 @itemx -S @var{pattern}
1989 Switch to a particular generation defined by @var{pattern}.
1991 @var{pattern} may be either a generation number or a number prefixed
1992 with ``+'' or ``-''. The latter means: move forward/backward by a
1993 specified number of generations. For example, if you want to return to
1994 the latest generation after @code{--roll-back}, use
1995 @code{--switch-generation=+1}.
1997 The difference between @code{--roll-back} and
1998 @code{--switch-generation=-1} is that @code{--switch-generation} will
1999 not make a zeroth generation, so if a specified generation does not
2000 exist, the current generation will not be changed.
2002 @item --search-paths[=@var{kind}]
2003 @cindex search paths
2004 Report environment variable definitions, in Bash syntax, that may be
2005 needed in order to use the set of installed packages. These environment
2006 variables are used to specify @dfn{search paths} for files used by some
2007 of the installed packages.
2009 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2010 environment variables to be defined so it can look for headers and
2011 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2012 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2013 library are installed in the profile, then @code{--search-paths} will
2014 suggest setting these variables to @code{@var{profile}/include} and
2015 @code{@var{profile}/lib}, respectively.
2017 The typical use case is to define these environment variables in the
2021 $ eval `guix package --search-paths`
2024 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2025 meaning that the returned environment variable definitions will either
2026 be exact settings, or prefixes or suffixes of the current value of these
2027 variables. When omitted, @var{kind} defaults to @code{exact}.
2029 This option can also be used to compute the @emph{combined} search paths
2030 of several profiles. Consider this example:
2033 $ guix package -p foo -i guile
2034 $ guix package -p bar -i guile-json
2035 $ guix package -p foo -p bar --search-paths
2038 The last command above reports about the @code{GUILE_LOAD_PATH}
2039 variable, even though, taken individually, neither @file{foo} nor
2040 @file{bar} would lead to that recommendation.
2043 @item --profile=@var{profile}
2044 @itemx -p @var{profile}
2045 Use @var{profile} instead of the user's default profile.
2047 @cindex collisions, in a profile
2048 @cindex colliding packages in profiles
2049 @cindex profile collisions
2050 @item --allow-collisions
2051 Allow colliding packages in the new profile. Use at your own risk!
2053 By default, @command{guix package} reports as an error @dfn{collisions}
2054 in the profile. Collisions happen when two or more different versions
2055 or variants of a given package end up in the profile.
2058 Produce verbose output. In particular, emit the build log of the
2059 environment on the standard error port.
2062 Use the bootstrap Guile to build the profile. This option is only
2063 useful to distribution developers.
2067 In addition to these actions, @command{guix package} supports the
2068 following options to query the current state of a profile, or the
2069 availability of packages:
2073 @item --search=@var{regexp}
2074 @itemx -s @var{regexp}
2075 @cindex searching for packages
2076 List the available packages whose name, synopsis, or description matches
2077 @var{regexp}, sorted by relevance. Print all the metadata of matching packages in
2078 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
2079 GNU recutils manual}).
2081 This allows specific fields to be extracted using the @command{recsel}
2082 command, for instance:
2085 $ guix package -s malloc | recsel -p name,version,relevance
2099 Similarly, to show the name of all the packages available under the
2100 terms of the GNU@tie{}LGPL version 3:
2103 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
2110 It is also possible to refine search results using several @code{-s}
2111 flags. For example, the following command returns a list of board
2115 $ guix package -s '\<board\>' -s game | recsel -p name
2120 If we were to omit @code{-s game}, we would also get software packages
2121 that deal with printed circuit boards; removing the angle brackets
2122 around @code{board} would further add packages that have to do with
2125 And now for a more elaborate example. The following command searches
2126 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
2127 libraries, and prints the name and synopsis of the matching packages:
2130 $ guix package -s crypto -s library | \
2131 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
2135 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
2136 information on @dfn{selection expressions} for @code{recsel -e}.
2138 @item --show=@var{package}
2139 Show details about @var{package}, taken from the list of available packages, in
2140 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
2144 $ guix package --show=python | recsel -p name,version
2152 You may also specify the full name of a package to only get details about a
2153 specific version of it:
2155 $ guix package --show=python@@3.4 | recsel -p name,version
2162 @item --list-installed[=@var{regexp}]
2163 @itemx -I [@var{regexp}]
2164 List the currently installed packages in the specified profile, with the
2165 most recently installed packages shown last. When @var{regexp} is
2166 specified, list only installed packages whose name matches @var{regexp}.
2168 For each installed package, print the following items, separated by
2169 tabs: the package name, its version string, the part of the package that
2170 is installed (for instance, @code{out} for the default output,
2171 @code{include} for its headers, etc.), and the path of this package in
2174 @item --list-available[=@var{regexp}]
2175 @itemx -A [@var{regexp}]
2176 List packages currently available in the distribution for this system
2177 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
2178 installed packages whose name matches @var{regexp}.
2180 For each package, print the following items separated by tabs: its name,
2181 its version string, the parts of the package (@pxref{Packages with
2182 Multiple Outputs}), and the source location of its definition.
2184 @item --list-generations[=@var{pattern}]
2185 @itemx -l [@var{pattern}]
2187 Return a list of generations along with their creation dates; for each
2188 generation, show the installed packages, with the most recently
2189 installed packages shown last. Note that the zeroth generation is never
2192 For each installed package, print the following items, separated by
2193 tabs: the name of a package, its version string, the part of the package
2194 that is installed (@pxref{Packages with Multiple Outputs}), and the
2195 location of this package in the store.
2197 When @var{pattern} is used, the command returns only matching
2198 generations. Valid patterns include:
2201 @item @emph{Integers and comma-separated integers}. Both patterns denote
2202 generation numbers. For instance, @code{--list-generations=1} returns
2205 And @code{--list-generations=1,8,2} outputs three generations in the
2206 specified order. Neither spaces nor trailing commas are allowed.
2208 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
2209 specified generations and everything in between. Note that the start of
2210 a range must be smaller than its end.
2212 It is also possible to omit the endpoint. For example,
2213 @code{--list-generations=2..}, returns all generations starting from the
2216 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
2217 or months by passing an integer along with the first letter of the
2218 duration. For example, @code{--list-generations=20d} lists generations
2219 that are up to 20 days old.
2222 @item --delete-generations[=@var{pattern}]
2223 @itemx -d [@var{pattern}]
2224 When @var{pattern} is omitted, delete all generations except the current
2227 This command accepts the same patterns as @option{--list-generations}.
2228 When @var{pattern} is specified, delete the matching generations. When
2229 @var{pattern} specifies a duration, generations @emph{older} than the
2230 specified duration match. For instance, @code{--delete-generations=1m}
2231 deletes generations that are more than one month old.
2233 If the current generation matches, it is @emph{not} deleted. Also, the
2234 zeroth generation is never deleted.
2236 Note that deleting generations prevents rolling back to them.
2237 Consequently, this command must be used with care.
2241 Finally, since @command{guix package} may actually start build
2242 processes, it supports all the common build options (@pxref{Common Build
2243 Options}). It also supports package transformation options, such as
2244 @option{--with-source} (@pxref{Package Transformation Options}).
2245 However, note that package transformations are lost when upgrading; to
2246 preserve transformations across upgrades, you should define your own
2247 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
2248 (@pxref{Defining Packages}).
2251 @section Substitutes
2254 @cindex pre-built binaries
2255 Guix supports transparent source/binary deployment, which means that it
2256 can either build things locally, or download pre-built items from a
2257 server, or both. We call these pre-built items @dfn{substitutes}---they
2258 are substitutes for local build results. In many cases, downloading a
2259 substitute is much faster than building things locally.
2261 Substitutes can be anything resulting from a derivation build
2262 (@pxref{Derivations}). Of course, in the common case, they are
2263 pre-built package binaries, but source tarballs, for instance, which
2264 also result from derivation builds, can be available as substitutes.
2267 * Official Substitute Server:: One particular source of substitutes.
2268 * Substitute Server Authorization:: How to enable or disable substitutes.
2269 * Substitute Authentication:: How Guix verifies substitutes.
2270 * Proxy Settings:: How to get substitutes via proxy.
2271 * Substitution Failure:: What happens when substitution fails.
2272 * On Trusting Binaries:: How can you trust that binary blob?
2275 @node Official Substitute Server
2276 @subsection Official Substitute Server
2280 The @code{mirror.hydra.gnu.org} server is a front-end to an official build farm
2281 that builds packages from Guix continuously for some
2282 architectures, and makes them available as substitutes. This is the
2283 default source of substitutes; it can be overridden by passing the
2284 @option{--substitute-urls} option either to @command{guix-daemon}
2285 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
2286 or to client tools such as @command{guix package}
2287 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
2290 Substitute URLs can be either HTTP or HTTPS.
2291 HTTPS is recommended because communications are encrypted; conversely,
2292 using HTTP makes all communications visible to an eavesdropper, who
2293 could use the information gathered to determine, for instance, whether
2294 your system has unpatched security vulnerabilities.
2296 Substitutes from the official build farm are enabled by default when
2297 using the Guix System Distribution (@pxref{GNU Distribution}). However,
2298 they are disabled by default when using Guix on a foreign distribution,
2299 unless you have explicitly enabled them via one of the recommended
2300 installation steps (@pxref{Installation}). The following paragraphs
2301 describe how to enable or disable substitutes for the official build
2302 farm; the same procedure can also be used to enable substitutes for any
2303 other substitute server.
2305 @node Substitute Server Authorization
2306 @subsection Substitute Server Authorization
2309 @cindex substitutes, authorization thereof
2310 @cindex access control list (ACL), for substitutes
2311 @cindex ACL (access control list), for substitutes
2312 To allow Guix to download substitutes from @code{hydra.gnu.org} or a
2314 must add its public key to the access control list (ACL) of archive
2315 imports, using the @command{guix archive} command (@pxref{Invoking guix
2316 archive}). Doing so implies that you trust @code{hydra.gnu.org} to not
2317 be compromised and to serve genuine substitutes.
2319 The public key for @code{hydra.gnu.org} is installed along with Guix, in
2320 @code{@var{prefix}/share/guix/hydra.gnu.org.pub}, where @var{prefix} is
2321 the installation prefix of Guix. If you installed Guix from source,
2322 make sure you checked the GPG signature of
2323 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
2324 Then, you can run something like this:
2327 # guix archive --authorize < @var{prefix}/share/guix/hydra.gnu.org.pub
2331 Similarly, the @file{berlin.guixsd.org.pub} file contains the public key
2332 for the project's new build farm, reachable at
2333 @indicateurl{https://berlin.guixsd.org}.
2335 As of this writing @code{berlin.guixsd.org} is being upgraded so it can
2336 better scale up, but you might want to give it a try. It is backed by
2337 20 x86_64/i686 build nodes and may be able to provide substitutes more
2338 quickly than @code{mirror.hydra.gnu.org}.
2341 Once this is in place, the output of a command like @code{guix build}
2342 should change from something like:
2345 $ guix build emacs --dry-run
2346 The following derivations would be built:
2347 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
2348 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
2349 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
2350 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
2358 $ guix build emacs --dry-run
2359 112.3 MB would be downloaded:
2360 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
2361 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
2362 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
2363 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
2368 This indicates that substitutes from @code{hydra.gnu.org} are usable and
2369 will be downloaded, when possible, for future builds.
2371 @cindex substitutes, how to disable
2372 The substitute mechanism can be disabled globally by running
2373 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
2374 guix-daemon}). It can also be disabled temporarily by passing the
2375 @code{--no-substitutes} option to @command{guix package}, @command{guix
2376 build}, and other command-line tools.
2378 @node Substitute Authentication
2379 @subsection Substitute Authentication
2381 @cindex digital signatures
2382 Guix detects and raises an error when attempting to use a substitute
2383 that has been tampered with. Likewise, it ignores substitutes that are
2384 not signed, or that are not signed by one of the keys listed in the ACL.
2386 There is one exception though: if an unauthorized server provides
2387 substitutes that are @emph{bit-for-bit identical} to those provided by
2388 an authorized server, then the unauthorized server becomes eligible for
2389 downloads. For example, assume we have chosen two substitute servers
2393 --substitute-urls="https://a.example.org https://b.example.org"
2397 @cindex reproducible builds
2398 If the ACL contains only the key for @code{b.example.org}, and if
2399 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
2400 then Guix will download substitutes from @code{a.example.org} because it
2401 comes first in the list and can be considered a mirror of
2402 @code{b.example.org}. In practice, independent build machines usually
2403 produce the same binaries, thanks to bit-reproducible builds (see
2406 When using HTTPS, the server's X.509 certificate is @emph{not} validated
2407 (in other words, the server is not authenticated), contrary to what
2408 HTTPS clients such as Web browsers usually do. This is because Guix
2409 authenticates substitute information itself, as explained above, which
2410 is what we care about (whereas X.509 certificates are about
2411 authenticating bindings between domain names and public keys.)
2413 @node Proxy Settings
2414 @subsection Proxy Settings
2417 Substitutes are downloaded over HTTP or HTTPS.
2418 The @code{http_proxy} environment
2419 variable can be set in the environment of @command{guix-daemon} and is
2420 honored for downloads of substitutes. Note that the value of
2421 @code{http_proxy} in the environment where @command{guix build},
2422 @command{guix package}, and other client commands are run has
2423 @emph{absolutely no effect}.
2425 @node Substitution Failure
2426 @subsection Substitution Failure
2428 Even when a substitute for a derivation is available, sometimes the
2429 substitution attempt will fail. This can happen for a variety of
2430 reasons: the substitute server might be offline, the substitute may
2431 recently have been deleted, the connection might have been interrupted,
2434 When substitutes are enabled and a substitute for a derivation is
2435 available, but the substitution attempt fails, Guix will attempt to
2436 build the derivation locally depending on whether or not
2437 @code{--fallback} was given (@pxref{fallback-option,, common build
2438 option @code{--fallback}}). Specifically, if @code{--fallback} was
2439 omitted, then no local build will be performed, and the derivation is
2440 considered to have failed. However, if @code{--fallback} was given,
2441 then Guix will attempt to build the derivation locally, and the success
2442 or failure of the derivation depends on the success or failure of the
2443 local build. Note that when substitutes are disabled or no substitute
2444 is available for the derivation in question, a local build will
2445 @emph{always} be performed, regardless of whether or not
2446 @code{--fallback} was given.
2448 To get an idea of how many substitutes are available right now, you can
2449 try running the @command{guix weather} command (@pxref{Invoking guix
2450 weather}). This command provides statistics on the substitutes provided
2453 @node On Trusting Binaries
2454 @subsection On Trusting Binaries
2456 @cindex trust, of pre-built binaries
2457 Today, each individual's control over their own computing is at the
2458 mercy of institutions, corporations, and groups with enough power and
2459 determination to subvert the computing infrastructure and exploit its
2460 weaknesses. While using @code{hydra.gnu.org} substitutes can be
2461 convenient, we encourage users to also build on their own, or even run
2462 their own build farm, such that @code{hydra.gnu.org} is less of an
2463 interesting target. One way to help is by publishing the software you
2464 build using @command{guix publish} so that others have one more choice
2465 of server to download substitutes from (@pxref{Invoking guix publish}).
2467 Guix has the foundations to maximize build reproducibility
2468 (@pxref{Features}). In most cases, independent builds of a given
2469 package or derivation should yield bit-identical results. Thus, through
2470 a diverse set of independent package builds, we can strengthen the
2471 integrity of our systems. The @command{guix challenge} command aims to
2472 help users assess substitute servers, and to assist developers in
2473 finding out about non-deterministic package builds (@pxref{Invoking guix
2474 challenge}). Similarly, the @option{--check} option of @command{guix
2475 build} allows users to check whether previously-installed substitutes
2476 are genuine by rebuilding them locally (@pxref{build-check,
2477 @command{guix build --check}}).
2479 In the future, we want Guix to have support to publish and retrieve
2480 binaries to/from other users, in a peer-to-peer fashion. If you would
2481 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
2483 @node Packages with Multiple Outputs
2484 @section Packages with Multiple Outputs
2486 @cindex multiple-output packages
2487 @cindex package outputs
2490 Often, packages defined in Guix have a single @dfn{output}---i.e., the
2491 source package leads to exactly one directory in the store. When running
2492 @command{guix package -i glibc}, one installs the default output of the
2493 GNU libc package; the default output is called @code{out}, but its name
2494 can be omitted as shown in this command. In this particular case, the
2495 default output of @code{glibc} contains all the C header files, shared
2496 libraries, static libraries, Info documentation, and other supporting
2499 Sometimes it is more appropriate to separate the various types of files
2500 produced from a single source package into separate outputs. For
2501 instance, the GLib C library (used by GTK+ and related packages)
2502 installs more than 20 MiB of reference documentation as HTML pages.
2503 To save space for users who do not need it, the documentation goes to a
2504 separate output, called @code{doc}. To install the main GLib output,
2505 which contains everything but the documentation, one would run:
2508 guix package -i glib
2511 @cindex documentation
2512 The command to install its documentation is:
2515 guix package -i glib:doc
2518 Some packages install programs with different ``dependency footprints''.
2519 For instance, the WordNet package installs both command-line tools and
2520 graphical user interfaces (GUIs). The former depend solely on the C
2521 library, whereas the latter depend on Tcl/Tk and the underlying X
2522 libraries. In this case, we leave the command-line tools in the default
2523 output, whereas the GUIs are in a separate output. This allows users
2524 who do not need the GUIs to save space. The @command{guix size} command
2525 can help find out about such situations (@pxref{Invoking guix size}).
2526 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
2528 There are several such multiple-output packages in the GNU distribution.
2529 Other conventional output names include @code{lib} for libraries and
2530 possibly header files, @code{bin} for stand-alone programs, and
2531 @code{debug} for debugging information (@pxref{Installing Debugging
2532 Files}). The outputs of a packages are listed in the third column of
2533 the output of @command{guix package --list-available} (@pxref{Invoking
2537 @node Invoking guix gc
2538 @section Invoking @command{guix gc}
2540 @cindex garbage collector
2542 Packages that are installed, but not used, may be @dfn{garbage-collected}.
2543 The @command{guix gc} command allows users to explicitly run the garbage
2544 collector to reclaim space from the @file{/gnu/store} directory. It is
2545 the @emph{only} way to remove files from @file{/gnu/store}---removing
2546 files or directories manually may break it beyond repair!
2549 @cindex garbage collector roots
2550 The garbage collector has a set of known @dfn{roots}: any file under
2551 @file{/gnu/store} reachable from a root is considered @dfn{live} and
2552 cannot be deleted; any other file is considered @dfn{dead} and may be
2553 deleted. The set of garbage collector roots (``GC roots'' for short)
2554 includes default user profiles; by default, the symlinks under
2555 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
2556 added with @command{guix build --root}, for example (@pxref{Invoking
2559 Prior to running @code{guix gc --collect-garbage} to make space, it is
2560 often useful to remove old generations from user profiles; that way, old
2561 package builds referenced by those generations can be reclaimed. This
2562 is achieved by running @code{guix package --delete-generations}
2563 (@pxref{Invoking guix package}).
2565 Our recommendation is to run a garbage collection periodically, or when
2566 you are short on disk space. For instance, to guarantee that at least
2567 5@tie{}GB are available on your disk, simply run:
2573 It is perfectly safe to run as a non-interactive periodic job
2574 (@pxref{Scheduled Job Execution}, for how to set up such a job on
2575 GuixSD). Running @command{guix gc} with no arguments will collect as
2576 much garbage as it can, but that is often inconvenient: you may find
2577 yourself having to rebuild or re-download software that is ``dead'' from
2578 the GC viewpoint but that is necessary to build other pieces of
2579 software---e.g., the compiler tool chain.
2581 The @command{guix gc} command has three modes of operation: it can be
2582 used to garbage-collect any dead files (the default), to delete specific
2583 files (the @code{--delete} option), to print garbage-collector
2584 information, or for more advanced queries. The garbage collection
2585 options are as follows:
2588 @item --collect-garbage[=@var{min}]
2589 @itemx -C [@var{min}]
2590 Collect garbage---i.e., unreachable @file{/gnu/store} files and
2591 sub-directories. This is the default operation when no option is
2594 When @var{min} is given, stop once @var{min} bytes have been collected.
2595 @var{min} may be a number of bytes, or it may include a unit as a
2596 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
2597 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
2599 When @var{min} is omitted, collect all the garbage.
2601 @item --free-space=@var{free}
2602 @itemx -F @var{free}
2603 Collect garbage until @var{free} space is available under
2604 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
2605 as @code{500MiB}, as described above.
2607 When @var{free} or more is already available in @file{/gnu/store}, do
2608 nothing and exit immediately.
2612 Attempt to delete all the store files and directories specified as
2613 arguments. This fails if some of the files are not in the store, or if
2614 they are still live.
2616 @item --list-failures
2617 List store items corresponding to cached build failures.
2619 This prints nothing unless the daemon was started with
2620 @option{--cache-failures} (@pxref{Invoking guix-daemon,
2621 @option{--cache-failures}}).
2623 @item --clear-failures
2624 Remove the specified store items from the failed-build cache.
2626 Again, this option only makes sense when the daemon is started with
2627 @option{--cache-failures}. Otherwise, it does nothing.
2630 Show the list of dead files and directories still present in the
2631 store---i.e., files and directories no longer reachable from any root.
2634 Show the list of live store files and directories.
2638 In addition, the references among existing store files can be queried:
2644 @cindex package dependencies
2645 List the references (respectively, the referrers) of store files given
2651 List the requisites of the store files passed as arguments. Requisites
2652 include the store files themselves, their references, and the references
2653 of these, recursively. In other words, the returned list is the
2654 @dfn{transitive closure} of the store files.
2656 @xref{Invoking guix size}, for a tool to profile the size of the closure
2657 of an element. @xref{Invoking guix graph}, for a tool to visualize
2658 the graph of references.
2662 Return the derivation(s) leading to the given store items
2663 (@pxref{Derivations}).
2665 For example, this command:
2668 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
2672 returns the @file{.drv} file(s) leading to the @code{emacs} package
2673 installed in your profile.
2675 Note that there may be zero matching @file{.drv} files, for instance
2676 because these files have been garbage-collected. There can also be more
2677 than one matching @file{.drv} due to fixed-output derivations.
2680 Lastly, the following options allow you to check the integrity of the
2681 store and to control disk usage.
2685 @item --verify[=@var{options}]
2686 @cindex integrity, of the store
2687 @cindex integrity checking
2688 Verify the integrity of the store.
2690 By default, make sure that all the store items marked as valid in the
2691 database of the daemon actually exist in @file{/gnu/store}.
2693 When provided, @var{options} must be a comma-separated list containing one
2694 or more of @code{contents} and @code{repair}.
2696 When passing @option{--verify=contents}, the daemon computes the
2697 content hash of each store item and compares it against its hash in the
2698 database. Hash mismatches are reported as data corruptions. Because it
2699 traverses @emph{all the files in the store}, this command can take a
2700 long time, especially on systems with a slow disk drive.
2702 @cindex repairing the store
2703 @cindex corruption, recovering from
2704 Using @option{--verify=repair} or @option{--verify=contents,repair}
2705 causes the daemon to try to repair corrupt store items by fetching
2706 substitutes for them (@pxref{Substitutes}). Because repairing is not
2707 atomic, and thus potentially dangerous, it is available only to the
2708 system administrator. A lightweight alternative, when you know exactly
2709 which items in the store are corrupt, is @command{guix build --repair}
2710 (@pxref{Invoking guix build}).
2713 @cindex deduplication
2714 Optimize the store by hard-linking identical files---this is
2715 @dfn{deduplication}.
2717 The daemon performs deduplication after each successful build or archive
2718 import, unless it was started with @code{--disable-deduplication}
2719 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
2720 this option is primarily useful when the daemon was running with
2721 @code{--disable-deduplication}.
2725 @node Invoking guix pull
2726 @section Invoking @command{guix pull}
2728 @cindex upgrading Guix
2729 @cindex updating Guix
2730 @cindex @command{guix pull}
2732 Packages are installed or upgraded to the latest version available in
2733 the distribution currently available on your local machine. To update
2734 that distribution, along with the Guix tools, you must run @command{guix
2735 pull}: the command downloads the latest Guix source code and package
2736 descriptions, and deploys it. Source code is downloaded from a
2737 @uref{https://git-scm.com, Git} repository.
2739 On completion, @command{guix package} will use packages and package
2740 versions from this just-retrieved copy of Guix. Not only that, but all
2741 the Guix commands and Scheme modules will also be taken from that latest
2742 version. New @command{guix} sub-commands added by the update also
2745 Any user can update their Guix copy using @command{guix pull}, and the
2746 effect is limited to the user who run @command{guix pull}. For
2747 instance, when user @code{root} runs @command{guix pull}, this has no
2748 effect on the version of Guix that user @code{alice} sees, and vice
2751 The result of running @command{guix pull} is a @dfn{profile} available
2752 under @file{~/.config/guix/current} containing the latest Guix. Thus,
2753 make sure to add it to the beginning of your search path so that you use
2754 the latest version, and similarly for the Info manual
2755 (@pxref{Documentation}):
2758 export PATH="$HOME/.config/guix/current/bin:$PATH"
2759 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
2762 The @code{--list-generations} or @code{-l} option lists past generations
2763 produced by @command{guix pull}, along with details about their provenance:
2767 Generation 1 Jun 10 2018 00:18:18
2769 repository URL: https://git.savannah.gnu.org/git/guix.git
2770 branch: origin/master
2771 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
2773 Generation 2 Jun 11 2018 11:02:49
2775 repository URL: https://git.savannah.gnu.org/git/guix.git
2776 branch: origin/master
2777 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
2779 Generation 3 Jun 13 2018 23:31:07 (current)
2781 repository URL: https://git.savannah.gnu.org/git/guix.git
2782 branch: origin/master
2783 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
2786 This @code{~/.config/guix/current} profile works like any other profile
2787 created by @command{guix package} (@pxref{Invoking guix package}). That
2788 is, you can list generations, roll back to the previous
2789 generation---i.e., the previous Guix---and so on:
2792 $ guix package -p ~/.config/guix/current --roll-back
2793 switched from generation 3 to 2
2794 $ guix package -p ~/.config/guix/current --delete-generations=1
2795 deleting /home/charlie/.config/guix/current-1-link
2798 The @command{guix pull} command is usually invoked with no arguments,
2799 but it supports the following options:
2803 Produce verbose output, writing build logs to the standard error output.
2805 @item --url=@var{url}
2806 Download Guix from the Git repository at @var{url}.
2808 @vindex GUIX_PULL_URL
2809 By default, the source is taken from its canonical Git repository at
2810 @code{gnu.org}, for the stable branch of Guix. To use a different source,
2811 set the @code{GUIX_PULL_URL} environment variable.
2813 @item --commit=@var{commit}
2814 Deploy @var{commit}, a valid Git commit ID represented as a hexadecimal
2817 @item --branch=@var{branch}
2818 Deploy the tip of @var{branch}, the name of a Git branch available on
2819 the repository at @var{url}.
2821 @item --list-generations[=@var{pattern}]
2822 @itemx -l [@var{pattern}]
2823 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
2824 is provided, the subset of generations that match @var{pattern}.
2825 The syntax of @var{pattern} is the same as with @code{guix package
2826 --list-generations} (@pxref{Invoking guix package}).
2829 Use the bootstrap Guile to build the latest Guix. This option is only
2830 useful to Guix developers.
2833 In addition, @command{guix pull} supports all the common build options
2834 (@pxref{Common Build Options}).
2836 @node Invoking guix pack
2837 @section Invoking @command{guix pack}
2839 Occasionally you want to pass software to people who are not (yet!)
2840 lucky enough to be using Guix. You'd tell them to run @command{guix
2841 package -i @var{something}}, but that's not possible in this case. This
2842 is where @command{guix pack} comes in.
2845 If you are looking for ways to exchange binaries among machines that
2846 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
2847 publish}, and @ref{Invoking guix archive}.
2852 @cindex application bundle
2853 @cindex software bundle
2854 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
2855 @dfn{software bundle}: it creates a tarball or some other archive
2856 containing the binaries of the software you're interested in, and all
2857 its dependencies. The resulting archive can be used on any machine that
2858 does not have Guix, and people can run the exact same binaries as those
2859 you have with Guix. The pack itself is created in a bit-reproducible
2860 fashion, so anyone can verify that it really contains the build results
2861 that you pretend to be shipping.
2863 For example, to create a bundle containing Guile, Emacs, Geiser, and all
2864 their dependencies, you can run:
2867 $ guix pack guile emacs geiser
2869 /gnu/store/@dots{}-pack.tar.gz
2872 The result here is a tarball containing a @file{/gnu/store} directory
2873 with all the relevant packages. The resulting tarball contains a
2874 @dfn{profile} with the three packages of interest; the profile is the
2875 same as would be created by @command{guix package -i}. It is this
2876 mechanism that is used to create Guix's own standalone binary tarball
2877 (@pxref{Binary Installation}).
2879 Users of this pack would have to run
2880 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
2881 find inconvenient. To work around it, you can create, say, a
2882 @file{/opt/gnu/bin} symlink to the profile:
2885 guix pack -S /opt/gnu/bin=bin guile emacs geiser
2889 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
2891 @cindex relocatable binaries, with @command{guix pack}
2892 What if the recipient of your pack does not have root privileges on
2893 their machine, and thus cannot unpack it in the root file system? In
2894 that case, you will want to use the @code{--relocatable} option (see
2895 below). This option produces @dfn{relocatable binaries}, meaning they
2896 they can be placed anywhere in the file system hierarchy: in the example
2897 above, users can unpack your tarball in their home directory and
2898 directly run @file{./opt/gnu/bin/guile}.
2900 @cindex Docker, build an image with guix pack
2901 Alternatively, you can produce a pack in the Docker image format using
2902 the following command:
2905 guix pack -f docker guile emacs geiser
2909 The result is a tarball that can be passed to the @command{docker load}
2911 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
2912 documentation} for more information.
2914 @cindex Singularity, build an image with guix pack
2915 @cindex SquashFS, build an image with guix pack
2916 Yet another option is to produce a SquashFS image with the following
2920 guix pack -f squashfs guile emacs geiser
2924 The result is a SquashFS file system image that can either be mounted or
2925 directly be used as a file system container image with the
2926 @uref{http://singularity.lbl.gov, Singularity container execution
2927 environment}, using commands like @command{singularity shell} or
2928 @command{singularity exec}.
2930 Several command-line options allow you to customize your pack:
2933 @item --format=@var{format}
2934 @itemx -f @var{format}
2935 Produce a pack in the given @var{format}.
2937 The available formats are:
2941 This is the default format. It produces a tarball containing all the
2942 specified binaries and symlinks.
2945 This produces a tarball that follows the
2946 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
2947 Docker Image Specification}.
2950 This produces a SquashFS image containing all the specified binaries and
2951 symlinks, as well as empty mount points for virtual file systems like
2957 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
2958 anywhere in the file system hierarchy and run from there. For example,
2959 if you create a pack containing Bash with:
2962 guix pack -R -S /mybin=bin bash
2966 ... you can copy that pack to a machine that lacks Guix, and from your
2967 home directory as a normal user, run:
2975 In that shell, if you type @code{ls /gnu/store}, you'll notice that
2976 @file{/gnu/store} shows up and contains all the dependencies of
2977 @code{bash}, even though the machine actually lacks @file{/gnu/store}
2978 altogether! That is probably the simplest way to deploy Guix-built
2979 software on a non-Guix machine.
2981 There's a gotcha though: this technique relies on the @dfn{user
2982 namespace} feature of the kernel Linux, which allows unprivileged users
2983 to mount or change root. Old versions of Linux did not support it, and
2984 some GNU/Linux distributions turn it off; on these systems, programs
2985 from the pack @emph{will fail to run}, unless they are unpacked in the
2988 @item --expression=@var{expr}
2989 @itemx -e @var{expr}
2990 Consider the package @var{expr} evaluates to.
2992 This has the same purpose as the same-named option in @command{guix
2993 build} (@pxref{Additional Build Options, @code{--expression} in
2994 @command{guix build}}).
2996 @item --manifest=@var{file}
2997 @itemx -m @var{file}
2998 Use the packages contained in the manifest object returned by the Scheme
3001 This has a similar purpose as the same-named option in @command{guix
3002 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
3003 same manifest files. It allows you to define a collection of packages
3004 once and use it both for creating profiles and for creating archives
3005 for use on machines that do not have Guix installed. Note that you can
3006 specify @emph{either} a manifest file @emph{or} a list of packages,
3009 @item --system=@var{system}
3010 @itemx -s @var{system}
3011 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3012 the system type of the build host.
3014 @item --target=@var{triplet}
3015 @cindex cross-compilation
3016 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
3017 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
3018 configuration triplets,, autoconf, Autoconf}).
3020 @item --compression=@var{tool}
3021 @itemx -C @var{tool}
3022 Compress the resulting tarball using @var{tool}---one of @code{gzip},
3023 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
3025 @item --symlink=@var{spec}
3026 @itemx -S @var{spec}
3027 Add the symlinks specified by @var{spec} to the pack. This option can
3028 appear several times.
3030 @var{spec} has the form @code{@var{source}=@var{target}}, where
3031 @var{source} is the symlink that will be created and @var{target} is the
3034 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
3035 symlink pointing to the @file{bin} sub-directory of the profile.
3037 @item --localstatedir
3038 Include the ``local state directory'', @file{/var/guix}, in the
3041 @file{/var/guix} contains the store database (@pxref{The Store}) as well
3042 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
3043 the pack means that the store is ``complete'' and manageable by Guix;
3044 not providing it pack means that the store is ``dead'': items cannot be
3045 added to it or removed from it after extraction of the pack.
3047 One use case for this is the Guix self-contained binary tarball
3048 (@pxref{Binary Installation}).
3051 Use the bootstrap binaries to build the pack. This option is only
3052 useful to Guix developers.
3055 In addition, @command{guix pack} supports all the common build options
3056 (@pxref{Common Build Options}) and all the package transformation
3057 options (@pxref{Package Transformation Options}).
3060 @node Invoking guix archive
3061 @section Invoking @command{guix archive}
3063 @cindex @command{guix archive}
3065 The @command{guix archive} command allows users to @dfn{export} files
3066 from the store into a single archive, and to later @dfn{import} them on
3067 a machine that runs Guix.
3068 In particular, it allows store files to be transferred from one machine
3069 to the store on another machine.
3072 If you're looking for a way to produce archives in a format suitable for
3073 tools other than Guix, @pxref{Invoking guix pack}.
3076 @cindex exporting store items
3077 To export store files as an archive to standard output, run:
3080 guix archive --export @var{options} @var{specifications}...
3083 @var{specifications} may be either store file names or package
3084 specifications, as for @command{guix package} (@pxref{Invoking guix
3085 package}). For instance, the following command creates an archive
3086 containing the @code{gui} output of the @code{git} package and the main
3087 output of @code{emacs}:
3090 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
3093 If the specified packages are not built yet, @command{guix archive}
3094 automatically builds them. The build process may be controlled with the
3095 common build options (@pxref{Common Build Options}).
3097 To transfer the @code{emacs} package to a machine connected over SSH,
3101 guix archive --export -r emacs | ssh the-machine guix archive --import
3105 Similarly, a complete user profile may be transferred from one machine
3106 to another like this:
3109 guix archive --export -r $(readlink -f ~/.guix-profile) | \
3110 ssh the-machine guix-archive --import
3114 However, note that, in both examples, all of @code{emacs} and the
3115 profile as well as all of their dependencies are transferred (due to
3116 @code{-r}), regardless of what is already available in the store on the
3117 target machine. The @code{--missing} option can help figure out which
3118 items are missing from the target store. The @command{guix copy}
3119 command simplifies and optimizes this whole process, so this is probably
3120 what you should use in this case (@pxref{Invoking guix copy}).
3122 @cindex nar, archive format
3123 @cindex normalized archive (nar)
3124 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
3125 comparable in spirit to `tar', but with differences
3126 that make it more appropriate for our purposes. First, rather than
3127 recording all Unix metadata for each file, the nar format only mentions
3128 the file type (regular, directory, or symbolic link); Unix permissions
3129 and owner/group are dismissed. Second, the order in which directory
3130 entries are stored always follows the order of file names according to
3131 the C locale collation order. This makes archive production fully
3134 When exporting, the daemon digitally signs the contents of the archive,
3135 and that digital signature is appended. When importing, the daemon
3136 verifies the signature and rejects the import in case of an invalid
3137 signature or if the signing key is not authorized.
3138 @c FIXME: Add xref to daemon doc about signatures.
3140 The main options are:
3144 Export the specified store files or packages (see below.) Write the
3145 resulting archive to the standard output.
3147 Dependencies are @emph{not} included in the output, unless
3148 @code{--recursive} is passed.
3152 When combined with @code{--export}, this instructs @command{guix
3153 archive} to include dependencies of the given items in the archive.
3154 Thus, the resulting archive is self-contained: it contains the closure
3155 of the exported store items.
3158 Read an archive from the standard input, and import the files listed
3159 therein into the store. Abort if the archive has an invalid digital
3160 signature, or if it is signed by a public key not among the authorized
3161 keys (see @code{--authorize} below.)
3164 Read a list of store file names from the standard input, one per line,
3165 and write on the standard output the subset of these files missing from
3168 @item --generate-key[=@var{parameters}]
3169 @cindex signing, archives
3170 Generate a new key pair for the daemon. This is a prerequisite before
3171 archives can be exported with @code{--export}. Note that this operation
3172 usually takes time, because it needs to gather enough entropy to
3173 generate the key pair.
3175 The generated key pair is typically stored under @file{/etc/guix}, in
3176 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
3177 key, which must be kept secret.) When @var{parameters} is omitted,
3178 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
3179 versions before 1.6.0, it is a 4096-bit RSA key.
3180 Alternatively, @var{parameters} can specify
3181 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
3182 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
3183 Libgcrypt Reference Manual}).
3186 @cindex authorizing, archives
3187 Authorize imports signed by the public key passed on standard input.
3188 The public key must be in ``s-expression advanced format''---i.e., the
3189 same format as the @file{signing-key.pub} file.
3191 The list of authorized keys is kept in the human-editable file
3192 @file{/etc/guix/acl}. The file contains
3193 @url{http://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
3194 s-expressions''} and is structured as an access-control list in the
3195 @url{http://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
3198 @item --extract=@var{directory}
3199 @itemx -x @var{directory}
3200 Read a single-item archive as served by substitute servers
3201 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
3202 low-level operation needed in only very narrow use cases; see below.
3204 For example, the following command extracts the substitute for Emacs
3205 served by @code{hydra.gnu.org} to @file{/tmp/emacs}:
3209 https://hydra.gnu.org/nar/@dots{}-emacs-24.5 \
3210 | bunzip2 | guix archive -x /tmp/emacs
3213 Single-item archives are different from multiple-item archives produced
3214 by @command{guix archive --export}; they contain a single store item,
3215 and they do @emph{not} embed a signature. Thus this operation does
3216 @emph{no} signature verification and its output should be considered
3219 The primary purpose of this operation is to facilitate inspection of
3220 archive contents coming from possibly untrusted substitute servers.
3224 @c *********************************************************************
3225 @node Programming Interface
3226 @chapter Programming Interface
3228 GNU Guix provides several Scheme programming interfaces (APIs) to
3229 define, build, and query packages. The first interface allows users to
3230 write high-level package definitions. These definitions refer to
3231 familiar packaging concepts, such as the name and version of a package,
3232 its build system, and its dependencies. These definitions can then be
3233 turned into concrete build actions.
3235 Build actions are performed by the Guix daemon, on behalf of users. In a
3236 standard setup, the daemon has write access to the store---the
3237 @file{/gnu/store} directory---whereas users do not. The recommended
3238 setup also has the daemon perform builds in chroots, under a specific
3239 build users, to minimize interference with the rest of the system.
3242 Lower-level APIs are available to interact with the daemon and the
3243 store. To instruct the daemon to perform a build action, users actually
3244 provide it with a @dfn{derivation}. A derivation is a low-level
3245 representation of the build actions to be taken, and the environment in
3246 which they should occur---derivations are to package definitions what
3247 assembly is to C programs. The term ``derivation'' comes from the fact
3248 that build results @emph{derive} from them.
3250 This chapter describes all these APIs in turn, starting from high-level
3251 package definitions.
3254 * Defining Packages:: Defining new packages.
3255 * Build Systems:: Specifying how packages are built.
3256 * The Store:: Manipulating the package store.
3257 * Derivations:: Low-level interface to package derivations.
3258 * The Store Monad:: Purely functional interface to the store.
3259 * G-Expressions:: Manipulating build expressions.
3262 @node Defining Packages
3263 @section Defining Packages
3265 The high-level interface to package definitions is implemented in the
3266 @code{(guix packages)} and @code{(guix build-system)} modules. As an
3267 example, the package definition, or @dfn{recipe}, for the GNU Hello
3268 package looks like this:
3271 (define-module (gnu packages hello)
3272 #:use-module (guix packages)
3273 #:use-module (guix download)
3274 #:use-module (guix build-system gnu)
3275 #:use-module (guix licenses)
3276 #:use-module (gnu packages gawk))
3278 (define-public hello
3284 (uri (string-append "mirror://gnu/hello/hello-" version
3288 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
3289 (build-system gnu-build-system)
3290 (arguments '(#:configure-flags '("--enable-silent-rules")))
3291 (inputs `(("gawk" ,gawk)))
3292 (synopsis "Hello, GNU world: An example GNU package")
3293 (description "Guess what GNU Hello prints!")
3294 (home-page "http://www.gnu.org/software/hello/")
3299 Without being a Scheme expert, the reader may have guessed the meaning
3300 of the various fields here. This expression binds the variable
3301 @code{hello} to a @code{<package>} object, which is essentially a record
3302 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
3303 This package object can be inspected using procedures found in the
3304 @code{(guix packages)} module; for instance, @code{(package-name hello)}
3305 returns---surprise!---@code{"hello"}.
3307 With luck, you may be able to import part or all of the definition of
3308 the package you are interested in from another repository, using the
3309 @code{guix import} command (@pxref{Invoking guix import}).
3311 In the example above, @var{hello} is defined in a module of its own,
3312 @code{(gnu packages hello)}. Technically, this is not strictly
3313 necessary, but it is convenient to do so: all the packages defined in
3314 modules under @code{(gnu packages @dots{})} are automatically known to
3315 the command-line tools (@pxref{Package Modules}).
3317 There are a few points worth noting in the above package definition:
3321 The @code{source} field of the package is an @code{<origin>} object
3322 (@pxref{origin Reference}, for the complete reference).
3323 Here, the @code{url-fetch} method from @code{(guix download)} is used,
3324 meaning that the source is a file to be downloaded over FTP or HTTP.
3326 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
3327 the GNU mirrors defined in @code{(guix download)}.
3329 The @code{sha256} field specifies the expected SHA256 hash of the file
3330 being downloaded. It is mandatory, and allows Guix to check the
3331 integrity of the file. The @code{(base32 @dots{})} form introduces the
3332 base32 representation of the hash. You can obtain this information with
3333 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
3334 hash} (@pxref{Invoking guix hash}).
3337 When needed, the @code{origin} form can also have a @code{patches} field
3338 listing patches to be applied, and a @code{snippet} field giving a
3339 Scheme expression to modify the source code.
3342 @cindex GNU Build System
3343 The @code{build-system} field specifies the procedure to build the
3344 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
3345 represents the familiar GNU Build System, where packages may be
3346 configured, built, and installed with the usual @code{./configure &&
3347 make && make check && make install} command sequence.
3350 The @code{arguments} field specifies options for the build system
3351 (@pxref{Build Systems}). Here it is interpreted by
3352 @var{gnu-build-system} as a request run @file{configure} with the
3353 @code{--enable-silent-rules} flag.
3359 What about these quote (@code{'}) characters? They are Scheme syntax to
3360 introduce a literal list; @code{'} is synonymous with @code{quote}.
3361 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
3362 for details. Here the value of the @code{arguments} field is a list of
3363 arguments passed to the build system down the road, as with @code{apply}
3364 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
3367 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
3368 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
3369 @code{#:configure-flags} is a keyword used to pass a keyword argument
3370 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
3374 The @code{inputs} field specifies inputs to the build process---i.e.,
3375 build-time or run-time dependencies of the package. Here, we define an
3376 input called @code{"gawk"} whose value is that of the @var{gawk}
3377 variable; @var{gawk} is itself bound to a @code{<package>} object.
3379 @cindex backquote (quasiquote)
3382 @cindex comma (unquote)
3386 @findex unquote-splicing
3387 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
3388 us to introduce a literal list in the @code{inputs} field, while
3389 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
3390 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
3393 Note that GCC, Coreutils, Bash, and other essential tools do not need to
3394 be specified as inputs here. Instead, @var{gnu-build-system} takes care
3395 of ensuring that they are present (@pxref{Build Systems}).
3397 However, any other dependencies need to be specified in the
3398 @code{inputs} field. Any dependency not specified here will simply be
3399 unavailable to the build process, possibly leading to a build failure.
3402 @xref{package Reference}, for a full description of possible fields.
3404 Once a package definition is in place, the
3405 package may actually be built using the @code{guix build} command-line
3406 tool (@pxref{Invoking guix build}), troubleshooting any build failures
3407 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
3408 package definition using the @command{guix edit} command
3409 (@pxref{Invoking guix edit}).
3410 @xref{Packaging Guidelines}, for
3411 more information on how to test package definitions, and
3412 @ref{Invoking guix lint}, for information on how to check a definition
3413 for style conformance.
3414 @vindex GUIX_PACKAGE_PATH
3415 Lastly, @pxref{Package Modules}, for information
3416 on how to extend the distribution by adding your own package definitions
3417 to @code{GUIX_PACKAGE_PATH}.
3419 Finally, updating the package definition to a new upstream version
3420 can be partly automated by the @command{guix refresh} command
3421 (@pxref{Invoking guix refresh}).
3423 Behind the scenes, a derivation corresponding to the @code{<package>}
3424 object is first computed by the @code{package-derivation} procedure.
3425 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
3426 The build actions it prescribes may then be realized by using the
3427 @code{build-derivations} procedure (@pxref{The Store}).
3429 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
3430 Return the @code{<derivation>} object of @var{package} for @var{system}
3431 (@pxref{Derivations}).
3433 @var{package} must be a valid @code{<package>} object, and @var{system}
3434 must be a string denoting the target system type---e.g.,
3435 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
3436 must be a connection to the daemon, which operates on the store
3437 (@pxref{The Store}).
3441 @cindex cross-compilation
3442 Similarly, it is possible to compute a derivation that cross-builds a
3443 package for some other system:
3445 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
3446 @var{package} @var{target} [@var{system}]
3447 Return the @code{<derivation>} object of @var{package} cross-built from
3448 @var{system} to @var{target}.
3450 @var{target} must be a valid GNU triplet denoting the target hardware
3451 and operating system, such as @code{"mips64el-linux-gnu"}
3452 (@pxref{Configuration Names, GNU configuration triplets,, configure, GNU
3453 Configure and Build System}).
3456 @cindex package transformations
3457 @cindex input rewriting
3458 @cindex dependency tree rewriting
3459 Packages can be manipulated in arbitrary ways. An example of a useful
3460 transformation is @dfn{input rewriting}, whereby the dependency tree of
3461 a package is rewritten by replacing specific inputs by others:
3463 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
3464 [@var{rewrite-name}]
3465 Return a procedure that, when passed a package, replaces its direct and
3466 indirect dependencies (but not its implicit inputs) according to
3467 @var{replacements}. @var{replacements} is a list of package pairs; the
3468 first element of each pair is the package to replace, and the second one
3471 Optionally, @var{rewrite-name} is a one-argument procedure that takes
3472 the name of a package and returns its new name after rewrite.
3476 Consider this example:
3479 (define libressl-instead-of-openssl
3480 ;; This is a procedure to replace OPENSSL by LIBRESSL,
3482 (package-input-rewriting `((,openssl . ,libressl))))
3484 (define git-with-libressl
3485 (libressl-instead-of-openssl git))
3489 Here we first define a rewriting procedure that replaces @var{openssl}
3490 with @var{libressl}. Then we use it to define a @dfn{variant} of the
3491 @var{git} package that uses @var{libressl} instead of @var{openssl}.
3492 This is exactly what the @option{--with-input} command-line option does
3493 (@pxref{Package Transformation Options, @option{--with-input}}).
3495 A more generic procedure to rewrite a package dependency graph is
3496 @code{package-mapping}: it supports arbitrary changes to nodes in the
3499 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
3500 Return a procedure that, given a package, applies @var{proc} to all the packages
3501 depended on and returns the resulting package. The procedure stops recursion
3502 when @var{cut?} returns true for a given package.
3506 * package Reference :: The package data type.
3507 * origin Reference:: The origin data type.
3511 @node package Reference
3512 @subsection @code{package} Reference
3514 This section summarizes all the options available in @code{package}
3515 declarations (@pxref{Defining Packages}).
3517 @deftp {Data Type} package
3518 This is the data type representing a package recipe.
3522 The name of the package, as a string.
3524 @item @code{version}
3525 The version of the package, as a string.
3528 An object telling how the source code for the package should be
3529 acquired. Most of the time, this is an @code{origin} object, which
3530 denotes a file fetched from the Internet (@pxref{origin Reference}). It
3531 can also be any other ``file-like'' object such as a @code{local-file},
3532 which denotes a file from the local file system (@pxref{G-Expressions,
3533 @code{local-file}}).
3535 @item @code{build-system}
3536 The build system that should be used to build the package (@pxref{Build
3539 @item @code{arguments} (default: @code{'()})
3540 The arguments that should be passed to the build system. This is a
3541 list, typically containing sequential keyword-value pairs.
3543 @item @code{inputs} (default: @code{'()})
3544 @itemx @code{native-inputs} (default: @code{'()})
3545 @itemx @code{propagated-inputs} (default: @code{'()})
3546 @cindex inputs, of packages
3547 These fields list dependencies of the package. Each one is a list of
3548 tuples, where each tuple has a label for the input (a string) as its
3549 first element, a package, origin, or derivation as its second element,
3550 and optionally the name of the output thereof that should be used, which
3551 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
3552 more on package outputs). For example, the list below specifies three
3556 `(("libffi" ,libffi)
3557 ("libunistring" ,libunistring)
3558 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
3561 @cindex cross compilation, package dependencies
3562 The distinction between @code{native-inputs} and @code{inputs} is
3563 necessary when considering cross-compilation. When cross-compiling,
3564 dependencies listed in @code{inputs} are built for the @emph{target}
3565 architecture; conversely, dependencies listed in @code{native-inputs}
3566 are built for the architecture of the @emph{build} machine.
3568 @code{native-inputs} is typically used to list tools needed at
3569 build time, but not at run time, such as Autoconf, Automake, pkg-config,
3570 Gettext, or Bison. @command{guix lint} can report likely mistakes in
3571 this area (@pxref{Invoking guix lint}).
3573 @anchor{package-propagated-inputs}
3574 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
3575 specified packages will be automatically installed alongside the package
3576 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
3577 package}}, for information on how @command{guix package} deals with
3580 For example this is necessary when a C/C++ library needs headers of
3581 another library to compile, or when a pkg-config file refers to another
3582 one @i{via} its @code{Requires} field.
3584 Another example where @code{propagated-inputs} is useful is for languages
3585 that lack a facility to record the run-time search path akin to the
3586 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
3587 more. To ensure that libraries written in those languages can find
3588 library code they depend on at run time, run-time dependencies must be
3589 listed in @code{propagated-inputs} rather than @code{inputs}.
3591 @item @code{self-native-input?} (default: @code{#f})
3592 This is a Boolean field telling whether the package should use itself as
3593 a native input when cross-compiling.
3595 @item @code{outputs} (default: @code{'("out")})
3596 The list of output names of the package. @xref{Packages with Multiple
3597 Outputs}, for typical uses of additional outputs.
3599 @item @code{native-search-paths} (default: @code{'()})
3600 @itemx @code{search-paths} (default: @code{'()})
3601 A list of @code{search-path-specification} objects describing
3602 search-path environment variables honored by the package.
3604 @item @code{replacement} (default: @code{#f})
3605 This must be either @code{#f} or a package object that will be used as a
3606 @dfn{replacement} for this package. @xref{Security Updates, grafts},
3609 @item @code{synopsis}
3610 A one-line description of the package.
3612 @item @code{description}
3613 A more elaborate description of the package.
3615 @item @code{license}
3616 @cindex license, of packages
3617 The license of the package; a value from @code{(guix licenses)},
3618 or a list of such values.
3620 @item @code{home-page}
3621 The URL to the home-page of the package, as a string.
3623 @item @code{supported-systems} (default: @var{%supported-systems})
3624 The list of systems supported by the package, as strings of the form
3625 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
3627 @item @code{maintainers} (default: @code{'()})
3628 The list of maintainers of the package, as @code{maintainer} objects.
3630 @item @code{location} (default: source location of the @code{package} form)
3631 The source location of the package. It is useful to override this when
3632 inheriting from another package, in which case this field is not
3633 automatically corrected.
3638 @node origin Reference
3639 @subsection @code{origin} Reference
3641 This section summarizes all the options available in @code{origin}
3642 declarations (@pxref{Defining Packages}).
3644 @deftp {Data Type} origin
3645 This is the data type representing a source code origin.
3649 An object containing the URI of the source. The object type depends on
3650 the @code{method} (see below). For example, when using the
3651 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
3652 values are: a URL represented as a string, or a list thereof.
3655 A procedure that handles the URI.
3660 @item @var{url-fetch} from @code{(guix download)}
3661 download a file from the HTTP, HTTPS, or FTP URL specified in the
3665 @item @var{git-fetch} from @code{(guix git-download)}
3666 clone the Git version control repository, and check out the revision
3667 specified in the @code{uri} field as a @code{git-reference} object; a
3668 @code{git-reference} looks like this:
3672 (url "git://git.debian.org/git/pkg-shadow/shadow")
3673 (commit "v4.1.5.1"))
3678 A bytevector containing the SHA-256 hash of the source. Typically the
3679 @code{base32} form is used here to generate the bytevector from a
3682 You can obtain this information using @code{guix download}
3683 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
3686 @item @code{file-name} (default: @code{#f})
3687 The file name under which the source code should be saved. When this is
3688 @code{#f}, a sensible default value will be used in most cases. In case
3689 the source is fetched from a URL, the file name from the URL will be
3690 used. For version control checkouts, it is recommended to provide the
3691 file name explicitly because the default is not very descriptive.
3693 @item @code{patches} (default: @code{'()})
3694 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
3695 file-like objects}) pointing to patches to be applied to the source.
3697 This list of patches must be unconditional. In particular, it cannot
3698 depend on the value of @code{%current-system} or
3699 @code{%current-target-system}.
3701 @item @code{snippet} (default: @code{#f})
3702 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
3703 in the source directory. This is a convenient way to modify the source,
3704 sometimes more convenient than a patch.
3706 @item @code{patch-flags} (default: @code{'("-p1")})
3707 A list of command-line flags that should be passed to the @code{patch}
3710 @item @code{patch-inputs} (default: @code{#f})
3711 Input packages or derivations to the patching process. When this is
3712 @code{#f}, the usual set of inputs necessary for patching are provided,
3713 such as GNU@tie{}Patch.
3715 @item @code{modules} (default: @code{'()})
3716 A list of Guile modules that should be loaded during the patching
3717 process and while running the code in the @code{snippet} field.
3719 @item @code{patch-guile} (default: @code{#f})
3720 The Guile package that should be used in the patching process. When
3721 this is @code{#f}, a sensible default is used.
3727 @section Build Systems
3729 @cindex build system
3730 Each package definition specifies a @dfn{build system} and arguments for
3731 that build system (@pxref{Defining Packages}). This @code{build-system}
3732 field represents the build procedure of the package, as well as implicit
3733 dependencies of that build procedure.
3735 Build systems are @code{<build-system>} objects. The interface to
3736 create and manipulate them is provided by the @code{(guix build-system)}
3737 module, and actual build systems are exported by specific modules.
3739 @cindex bag (low-level package representation)
3740 Under the hood, build systems first compile package objects to
3741 @dfn{bags}. A @dfn{bag} is like a package, but with less
3742 ornamentation---in other words, a bag is a lower-level representation of
3743 a package, which includes all the inputs of that package, including some
3744 that were implicitly added by the build system. This intermediate
3745 representation is then compiled to a derivation (@pxref{Derivations}).
3747 Build systems accept an optional list of @dfn{arguments}. In package
3748 definitions, these are passed @i{via} the @code{arguments} field
3749 (@pxref{Defining Packages}). They are typically keyword arguments
3750 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
3751 Guile Reference Manual}). The value of these arguments is usually
3752 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
3753 by the daemon (@pxref{Derivations}).
3755 The main build system is @var{gnu-build-system}, which implements the
3756 standard build procedure for GNU and many other packages. It
3757 is provided by the @code{(guix build-system gnu)} module.
3759 @defvr {Scheme Variable} gnu-build-system
3760 @var{gnu-build-system} represents the GNU Build System, and variants
3761 thereof (@pxref{Configuration, configuration and makefile conventions,,
3762 standards, GNU Coding Standards}).
3764 @cindex build phases
3765 In a nutshell, packages using it are configured, built, and installed with
3766 the usual @code{./configure && make && make check && make install}
3767 command sequence. In practice, a few additional steps are often needed.
3768 All these steps are split up in separate @dfn{phases},
3769 notably@footnote{Please see the @code{(guix build gnu-build-system)}
3770 modules for more details about the build phases.}:
3774 Unpack the source tarball, and change the current directory to the
3775 extracted source tree. If the source is actually a directory, copy it
3776 to the build tree, and enter that directory.
3778 @item patch-source-shebangs
3779 Patch shebangs encountered in source files so they refer to the right
3780 store file names. For instance, this changes @code{#!/bin/sh} to
3781 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
3784 Run the @file{configure} script with a number of default options, such
3785 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
3786 by the @code{#:configure-flags} argument.
3789 Run @code{make} with the list of flags specified with
3790 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
3791 (the default), build with @code{make -j}.
3794 Run @code{make check}, or some other target specified with
3795 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
3796 @code{#:parallel-tests?} argument is true (the default), run @code{make
3800 Run @code{make install} with the flags listed in @code{#:make-flags}.
3802 @item patch-shebangs
3803 Patch shebangs on the installed executable files.
3806 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
3807 is false), copying them to the @code{debug} output when available
3808 (@pxref{Installing Debugging Files}).
3811 @vindex %standard-phases
3812 The build-side module @code{(guix build gnu-build-system)} defines
3813 @var{%standard-phases} as the default list of build phases.
3814 @var{%standard-phases} is a list of symbol/procedure pairs, where the
3815 procedure implements the actual phase.
3817 The list of phases used for a particular package can be changed with the
3818 @code{#:phases} parameter. For instance, passing:
3821 #:phases (modify-phases %standard-phases (delete 'configure))
3824 means that all the phases described above will be used, except the
3825 @code{configure} phase.
3827 In addition, this build system ensures that the ``standard'' environment
3828 for GNU packages is available. This includes tools such as GCC, libc,
3829 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
3830 build-system gnu)} module for a complete list). We call these the
3831 @dfn{implicit inputs} of a package, because package definitions do not
3832 have to mention them.
3835 Other @code{<build-system>} objects are defined to support other
3836 conventions and tools used by free software packages. They inherit most
3837 of @var{gnu-build-system}, and differ mainly in the set of inputs
3838 implicitly added to the build process, and in the list of phases
3839 executed. Some of these build systems are listed below.
3841 @defvr {Scheme Variable} ant-build-system
3842 This variable is exported by @code{(guix build-system ant)}. It
3843 implements the build procedure for Java packages that can be built with
3844 @url{http://ant.apache.org/, Ant build tool}.
3846 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
3847 provided by the @code{icedtea} package to the set of inputs. Different
3848 packages can be specified with the @code{#:ant} and @code{#:jdk}
3849 parameters, respectively.
3851 When the original package does not provide a suitable Ant build file,
3852 the parameter @code{#:jar-name} can be used to generate a minimal Ant
3853 build file @file{build.xml} with tasks to build the specified jar
3854 archive. In this case the parameter @code{#:source-dir} can be used to
3855 specify the source sub-directory, defaulting to ``src''.
3857 The @code{#:main-class} parameter can be used with the minimal ant
3858 buildfile to specify the main class of the resulting jar. This makes the
3859 jar file executable. The @code{#:test-include} parameter can be used to
3860 specify the list of junit tests to run. It defaults to
3861 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
3862 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
3863 because abstract classes cannot be run as tests.
3865 The parameter @code{#:build-target} can be used to specify the Ant task
3866 that should be run during the @code{build} phase. By default the
3867 ``jar'' task will be run.
3871 @defvr {Scheme Variable} android-ndk-build-system
3872 @cindex Android distribution
3873 @cindex Android NDK build system
3874 This variable is exported by @code{(guix build-system android-ndk)}. It
3875 implements a build procedure for Android NDK (native development kit)
3876 packages using a Guix-specific build process.
3878 The build system assumes that packages install their public interface
3879 (header) files to the subdirectory "include" of the "out" output and
3880 their libraries to the subdirectory "lib" of the "out" output.
3882 It's also assumed that the union of all the dependencies of a package
3883 has no conflicting files.
3885 For the time being, cross-compilation is not supported - so right now
3886 the libraries and header files are assumed to be host tools.
3890 @defvr {Scheme Variable} asdf-build-system/source
3891 @defvrx {Scheme Variable} asdf-build-system/sbcl
3892 @defvrx {Scheme Variable} asdf-build-system/ecl
3894 These variables, exported by @code{(guix build-system asdf)}, implement
3895 build procedures for Common Lisp packages using
3896 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
3897 definition facility for Common Lisp programs and libraries.
3899 The @code{asdf-build-system/source} system installs the packages in
3900 source form, and can be loaded using any common lisp implementation, via
3901 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
3902 systems in the format which a particular implementation understands.
3903 These build systems can also be used to produce executable programs, or
3904 lisp images which contain a set of packages pre-loaded.
3906 The build system uses naming conventions. For binary packages, the
3907 package name should be prefixed with the lisp implementation, such as
3908 @code{sbcl-} for @code{asdf-build-system/sbcl}.
3910 Additionally, the corresponding source package should be labeled using
3911 the same convention as python packages (see @ref{Python Modules}), using
3912 the @code{cl-} prefix.
3914 For binary packages, each system should be defined as a Guix package.
3915 If one package @code{origin} contains several systems, package variants
3916 can be created in order to build all the systems. Source packages,
3917 which use @code{asdf-build-system/source}, may contain several systems.
3919 In order to create executable programs and images, the build-side
3920 procedures @code{build-program} and @code{build-image} can be used.
3921 They should be called in a build phase after the @code{create-symlinks}
3922 phase, so that the system which was just built can be used within the
3923 resulting image. @code{build-program} requires a list of Common Lisp
3924 expressions to be passed as the @code{#:entry-program} argument.
3926 If the system is not defined within its own @code{.asd} file of the same
3927 name, then the @code{#:asd-file} parameter should be used to specify
3928 which file the system is defined in. Furthermore, if the package
3929 defines a system for its tests in a separate file, it will be loaded
3930 before the tests are run if it is specified by the
3931 @code{#:test-asd-file} parameter. If it is not set, the files
3932 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
3933 and @code{test.asd} will be tried if they exist.
3935 If for some reason the package must be named in a different way than the
3936 naming conventions suggest, the @code{#:asd-system-name} parameter can
3937 be used to specify the name of the system.
3941 @defvr {Scheme Variable} cargo-build-system
3942 @cindex Rust programming language
3943 @cindex Cargo (Rust build system)
3944 This variable is exported by @code{(guix build-system cargo)}. It
3945 supports builds of packages using Cargo, the build tool of the
3946 @uref{https://www.rust-lang.org, Rust programming language}.
3948 In its @code{configure} phase, this build system replaces dependencies
3949 specified in the @file{Carto.toml} file with inputs to the Guix package.
3950 The @code{install} phase installs the binaries, and it also installs the
3951 source code and @file{Cargo.toml} file.
3954 @defvr {Scheme Variable} cmake-build-system
3955 This variable is exported by @code{(guix build-system cmake)}. It
3956 implements the build procedure for packages using the
3957 @url{http://www.cmake.org, CMake build tool}.
3959 It automatically adds the @code{cmake} package to the set of inputs.
3960 Which package is used can be specified with the @code{#:cmake}
3963 The @code{#:configure-flags} parameter is taken as a list of flags
3964 passed to the @command{cmake} command. The @code{#:build-type}
3965 parameter specifies in abstract terms the flags passed to the compiler;
3966 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
3967 debugging information''), which roughly means that code is compiled with
3968 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
3971 @defvr {Scheme Variable} go-build-system
3972 This variable is exported by @code{(guix build-system go)}. It
3973 implements a build procedure for Go packages using the standard
3974 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
3975 Go build mechanisms}.
3977 The user is expected to provide a value for the key @code{#:import-path}
3978 and, in some cases, @code{#:unpack-path}. The
3979 @url{https://golang.org/doc/code.html#ImportPaths, import path}
3980 corresponds to the file system path expected by the package's build
3981 scripts and any referring packages, and provides a unique way to
3982 refer to a Go package. It is typically based on a combination of the
3983 package source code's remote URI and file system hierarchy structure. In
3984 some cases, you will need to unpack the package's source code to a
3985 different directory structure than the one indicated by the import path,
3986 and @code{#:unpack-path} should be used in such cases.
3988 Packages that provide Go libraries should be installed along with their
3989 source code. The key @code{#:install-source?}, which defaults to
3990 @code{#t}, controls whether or not the source code is installed. It can
3991 be set to @code{#f} for packages that only provide executable files.
3994 @defvr {Scheme Variable} glib-or-gtk-build-system
3995 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
3996 is intended for use with packages making use of GLib or GTK+.
3998 This build system adds the following two phases to the ones defined by
3999 @var{gnu-build-system}:
4002 @item glib-or-gtk-wrap
4003 The phase @code{glib-or-gtk-wrap} ensures that programs in
4004 @file{bin/} are able to find GLib ``schemas'' and
4005 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
4006 modules}. This is achieved by wrapping the programs in launch scripts
4007 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
4008 environment variables.
4010 It is possible to exclude specific package outputs from that wrapping
4011 process by listing their names in the
4012 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
4013 when an output is known not to contain any GLib or GTK+ binaries, and
4014 where wrapping would gratuitously add a dependency of that output on
4017 @item glib-or-gtk-compile-schemas
4018 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
4019 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
4020 GSettings schemas} of GLib are compiled. Compilation is performed by the
4021 @command{glib-compile-schemas} program. It is provided by the package
4022 @code{glib:bin} which is automatically imported by the build system.
4023 The @code{glib} package providing @command{glib-compile-schemas} can be
4024 specified with the @code{#:glib} parameter.
4027 Both phases are executed after the @code{install} phase.
4030 @defvr {Scheme Variable} minify-build-system
4031 This variable is exported by @code{(guix build-system minify)}. It
4032 implements a minification procedure for simple JavaScript packages.
4034 It adds @code{uglify-js} to the set of inputs and uses it to compress
4035 all JavaScript files in the @file{src} directory. A different minifier
4036 package can be specified with the @code{#:uglify-js} parameter, but it
4037 is expected that the package writes the minified code to the standard
4040 When the input JavaScript files are not all located in the @file{src}
4041 directory, the parameter @code{#:javascript-files} can be used to
4042 specify a list of file names to feed to the minifier.
4045 @defvr {Scheme Variable} ocaml-build-system
4046 This variable is exported by @code{(guix build-system ocaml)}. It implements
4047 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
4048 of choosing the correct set of commands to run for each package. OCaml
4049 packages can expect many different commands to be run. This build system will
4052 When the package has a @file{setup.ml} file present at the top-level, it will
4053 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
4054 @code{ocaml setup.ml -install}. The build system will assume that this file
4055 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
4056 care of setting the prefix and enabling tests if they are not disabled. You
4057 can pass configure and build flags with the @code{#:configure-flags} and
4058 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
4059 set of flags used to enable tests. The @code{#:use-make?} key can be used to
4060 bypass this system in the build and install phases.
4062 When the package has a @file{configure} file, it is assumed that it is a
4063 hand-made configure script that requires a different argument format than
4064 in the @code{gnu-build-system}. You can add more flags with the
4065 @code{#:configure-flags} key.
4067 When the package has a @file{Makefile} file (or @code{#:use-make?} is
4068 @code{#t}), it will be used and more flags can be passed to the build and
4069 install phases with the @code{#:make-flags} key.
4071 Finally, some packages do not have these files and use a somewhat standard
4072 location for its build system. In that case, the build system will run
4073 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
4074 providing the path to the required findlib module. Additional flags can
4075 be passed via the @code{#:build-flags} key. Install is taken care of by
4076 @command{opam-installer}. In this case, the @code{opam} package must
4077 be added to the @code{native-inputs} field of the package definition.
4079 Note that most OCaml packages assume they will be installed in the same
4080 directory as OCaml, which is not what we want in guix. In particular, they
4081 will install @file{.so} files in their module's directory, which is usually
4082 fine because it is in the OCaml compiler directory. In guix though, these
4083 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
4084 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
4085 @file{.so} libraries should be installed.
4088 @defvr {Scheme Variable} python-build-system
4089 This variable is exported by @code{(guix build-system python)}. It
4090 implements the more or less standard build procedure used by Python
4091 packages, which consists in running @code{python setup.py build} and
4092 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
4094 For packages that install stand-alone Python programs under @code{bin/},
4095 it takes care of wrapping these programs so that their @code{PYTHONPATH}
4096 environment variable points to all the Python libraries they depend on.
4098 Which Python package is used to perform the build can be specified with
4099 the @code{#:python} parameter. This is a useful way to force a package
4100 to be built for a specific version of the Python interpreter, which
4101 might be necessary if the package is only compatible with a single
4102 interpreter version.
4104 By default guix calls @code{setup.py} under control of
4105 @code{setuptools}, much like @command{pip} does. Some packages are not
4106 compatible with setuptools (and pip), thus you can disable this by
4107 setting the @code{#:use-setuptools} parameter to @code{#f}.
4110 @defvr {Scheme Variable} perl-build-system
4111 This variable is exported by @code{(guix build-system perl)}. It
4112 implements the standard build procedure for Perl packages, which either
4113 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
4114 followed by @code{Build} and @code{Build install}; or in running
4115 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
4116 @code{make} and @code{make install}, depending on which of
4117 @code{Build.PL} or @code{Makefile.PL} is present in the package
4118 distribution. Preference is given to the former if both @code{Build.PL}
4119 and @code{Makefile.PL} exist in the package distribution. This
4120 preference can be reversed by specifying @code{#t} for the
4121 @code{#:make-maker?} parameter.
4123 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
4124 passes flags specified by the @code{#:make-maker-flags} or
4125 @code{#:module-build-flags} parameter, respectively.
4127 Which Perl package is used can be specified with @code{#:perl}.
4130 @defvr {Scheme Variable} r-build-system
4131 This variable is exported by @code{(guix build-system r)}. It
4132 implements the build procedure used by @uref{http://r-project.org, R}
4133 packages, which essentially is little more than running @code{R CMD
4134 INSTALL --library=/gnu/store/@dots{}} in an environment where
4135 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
4136 are run after installation using the R function
4137 @code{tools::testInstalledPackage}.
4140 @defvr {Scheme Variable} texlive-build-system
4141 This variable is exported by @code{(guix build-system texlive)}. It is
4142 used to build TeX packages in batch mode with a specified engine. The
4143 build system sets the @code{TEXINPUTS} variable to find all TeX source
4144 files in the inputs.
4146 By default it runs @code{luatex} on all files ending on @code{ins}. A
4147 different engine and format can be specified with the
4148 @code{#:tex-format} argument. Different build targets can be specified
4149 with the @code{#:build-targets} argument, which expects a list of file
4150 names. The build system adds only @code{texlive-bin} and
4151 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
4152 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
4153 and @code{#:texlive-latex-base}, respectively.
4155 The @code{#:tex-directory} parameter tells the build system where to
4156 install the built files under the texmf tree.
4159 @defvr {Scheme Variable} ruby-build-system
4160 This variable is exported by @code{(guix build-system ruby)}. It
4161 implements the RubyGems build procedure used by Ruby packages, which
4162 involves running @code{gem build} followed by @code{gem install}.
4164 The @code{source} field of a package that uses this build system
4165 typically references a gem archive, since this is the format that Ruby
4166 developers use when releasing their software. The build system unpacks
4167 the gem archive, potentially patches the source, runs the test suite,
4168 repackages the gem, and installs it. Additionally, directories and
4169 tarballs may be referenced to allow building unreleased gems from Git or
4170 a traditional source release tarball.
4172 Which Ruby package is used can be specified with the @code{#:ruby}
4173 parameter. A list of additional flags to be passed to the @command{gem}
4174 command can be specified with the @code{#:gem-flags} parameter.
4177 @defvr {Scheme Variable} waf-build-system
4178 This variable is exported by @code{(guix build-system waf)}. It
4179 implements a build procedure around the @code{waf} script. The common
4180 phases---@code{configure}, @code{build}, and @code{install}---are
4181 implemented by passing their names as arguments to the @code{waf}
4184 The @code{waf} script is executed by the Python interpreter. Which
4185 Python package is used to run the script can be specified with the
4186 @code{#:python} parameter.
4189 @defvr {Scheme Variable} scons-build-system
4190 This variable is exported by @code{(guix build-system scons)}. It
4191 implements the build procedure used by the SCons software construction
4192 tool. This build system runs @code{scons} to build the package,
4193 @code{scons test} to run tests, and then @code{scons install} to install
4196 Additional flags to be passed to @code{scons} can be specified with the
4197 @code{#:scons-flags} parameter. The version of Python used to run SCons
4198 can be specified by selecting the appropriate SCons package with the
4199 @code{#:scons} parameter.
4202 @defvr {Scheme Variable} haskell-build-system
4203 This variable is exported by @code{(guix build-system haskell)}. It
4204 implements the Cabal build procedure used by Haskell packages, which
4205 involves running @code{runhaskell Setup.hs configure
4206 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
4207 Instead of installing the package by running @code{runhaskell Setup.hs
4208 install}, to avoid trying to register libraries in the read-only
4209 compiler store directory, the build system uses @code{runhaskell
4210 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
4211 addition, the build system generates the package documentation by
4212 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
4213 is passed. Optional Haddock parameters can be passed with the help of
4214 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
4215 not found, the build system looks for @code{Setup.lhs} instead.
4217 Which Haskell compiler is used can be specified with the @code{#:haskell}
4218 parameter which defaults to @code{ghc}.
4221 @defvr {Scheme Variable} dub-build-system
4222 This variable is exported by @code{(guix build-system dub)}. It
4223 implements the Dub build procedure used by D packages, which
4224 involves running @code{dub build} and @code{dub run}.
4225 Installation is done by copying the files manually.
4227 Which D compiler is used can be specified with the @code{#:ldc}
4228 parameter which defaults to @code{ldc}.
4231 @defvr {Scheme Variable} emacs-build-system
4232 This variable is exported by @code{(guix build-system emacs)}. It
4233 implements an installation procedure similar to the packaging system
4234 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
4236 It first creates the @code{@var{package}-autoloads.el} file, then it
4237 byte compiles all Emacs Lisp files. Differently from the Emacs
4238 packaging system, the Info documentation files are moved to the standard
4239 documentation directory and the @file{dir} file is deleted. Each
4240 package is installed in its own directory under
4241 @file{share/emacs/site-lisp/guix.d}.
4244 @defvr {Scheme Variable} font-build-system
4245 This variable is exported by @code{(guix build-system font)}. It
4246 implements an installation procedure for font packages where upstream
4247 provides pre-compiled TrueType, OpenType, etc. font files that merely
4248 need to be copied into place. It copies font files to standard
4249 locations in the output directory.
4252 @defvr {Scheme Variable} meson-build-system
4253 This variable is exported by @code{(guix build-system meson)}. It
4254 implements the build procedure for packages that use
4255 @url{http://mesonbuild.com, Meson} as their build system.
4257 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
4258 of inputs, and they can be changed with the parameters @code{#:meson}
4259 and @code{#:ninja} if needed. The default Meson is
4260 @code{meson-for-build}, which is special because it doesn't clear the
4261 @code{RUNPATH} of binaries and libraries when they are installed.
4263 This build system is an extension of @var{gnu-build-system}, but with the
4264 following phases changed to some specific for Meson:
4269 The phase runs @code{meson} with the flags specified in
4270 @code{#:configure-flags}. The flag @code{--build-type} is always set to
4271 @code{plain} unless something else is specified in @code{#:build-type}.
4274 The phase runs @code{ninja} to build the package in parallel by default, but
4275 this can be changed with @code{#:parallel-build?}.
4278 The phase runs @code{ninja} with the target specified in @code{#:test-target},
4279 which is @code{"test"} by default.
4282 The phase runs @code{ninja install} and can not be changed.
4285 Apart from that, the build system also adds the following phases:
4290 This phase ensures that all binaries can find the libraries they need.
4291 It searches for required libraries in subdirectories of the package being
4292 built, and adds those to @code{RUNPATH} where needed. It also removes
4293 references to libraries left over from the build phase by
4294 @code{meson-for-build}, such as test dependencies, that aren't actually
4295 required for the program to run.
4297 @item glib-or-gtk-wrap
4298 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
4299 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
4301 @item glib-or-gtk-compile-schemas
4302 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
4303 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
4307 Lastly, for packages that do not need anything as sophisticated, a
4308 ``trivial'' build system is provided. It is trivial in the sense that
4309 it provides basically no support: it does not pull any implicit inputs,
4310 and does not have a notion of build phases.
4312 @defvr {Scheme Variable} trivial-build-system
4313 This variable is exported by @code{(guix build-system trivial)}.
4315 This build system requires a @code{#:builder} argument. This argument
4316 must be a Scheme expression that builds the package output(s)---as
4317 with @code{build-expression->derivation} (@pxref{Derivations,
4318 @code{build-expression->derivation}}).
4328 Conceptually, the @dfn{store} is the place where derivations that have
4329 been built successfully are stored---by default, @file{/gnu/store}.
4330 Sub-directories in the store are referred to as @dfn{store items} or
4331 sometimes @dfn{store paths}. The store has an associated database that
4332 contains information such as the store paths referred to by each store
4333 path, and the list of @emph{valid} store items---results of successful
4334 builds. This database resides in @file{@var{localstatedir}/guix/db},
4335 where @var{localstatedir} is the state directory specified @i{via}
4336 @option{--localstatedir} at configure time, usually @file{/var}.
4338 The store is @emph{always} accessed by the daemon on behalf of its clients
4339 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
4340 connect to the daemon over a Unix-domain socket, send requests to it,
4341 and read the result---these are remote procedure calls, or RPCs.
4344 Users must @emph{never} modify files under @file{/gnu/store} directly.
4345 This would lead to inconsistencies and break the immutability
4346 assumptions of Guix's functional model (@pxref{Introduction}).
4348 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
4349 how to check the integrity of the store and attempt recovery from
4350 accidental modifications.
4353 The @code{(guix store)} module provides procedures to connect to the
4354 daemon, and to perform RPCs. These are described below. By default,
4355 @code{open-connection}, and thus all the @command{guix} commands,
4356 connect to the local daemon or to the URI specified by the
4357 @code{GUIX_DAEMON_SOCKET} environment variable.
4359 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
4360 When set, the value of this variable should be a file name or a URI
4361 designating the daemon endpoint. When it is a file name, it denotes a
4362 Unix-domain socket to connect to. In addition to file names, the
4363 supported URI schemes are:
4368 These are for Unix-domain sockets.
4369 @code{file:///var/guix/daemon-socket/socket} is equivalent to
4370 @file{/var/guix/daemon-socket/socket}.
4373 @cindex daemon, remote access
4374 @cindex remote access to the daemon
4375 @cindex daemon, cluster setup
4376 @cindex clusters, daemon setup
4377 These URIs denote connections over TCP/IP, without encryption nor
4378 authentication of the remote host. The URI must specify the host name
4379 and optionally a port number (by default port 44146 is used):
4382 guix://master.guix.example.org:1234
4385 This setup is suitable on local networks, such as clusters, where only
4386 trusted nodes may connect to the build daemon at
4387 @code{master.guix.example.org}.
4389 The @code{--listen} option of @command{guix-daemon} can be used to
4390 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
4394 @cindex SSH access to build daemons
4395 These URIs allow you to connect to a remote daemon over
4396 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
4397 A typical URL might look like this:
4400 ssh://charlie@@guix.example.org:22
4403 As for @command{guix copy}, the usual OpenSSH client configuration files
4404 are honored (@pxref{Invoking guix copy}).
4407 Additional URI schemes may be supported in the future.
4409 @c XXX: Remove this note when the protocol incurs fewer round trips
4410 @c and when (guix derivations) no longer relies on file system access.
4412 The ability to connect to remote build daemons is considered
4413 experimental as of @value{VERSION}. Please get in touch with us to
4414 share any problems or suggestions you may have (@pxref{Contributing}).
4418 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
4419 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
4420 @var{reserve-space?} is true, instruct it to reserve a little bit of
4421 extra space on the file system so that the garbage collector can still
4422 operate should the disk become full. Return a server object.
4424 @var{file} defaults to @var{%default-socket-path}, which is the normal
4425 location given the options that were passed to @command{configure}.
4428 @deffn {Scheme Procedure} close-connection @var{server}
4429 Close the connection to @var{server}.
4432 @defvr {Scheme Variable} current-build-output-port
4433 This variable is bound to a SRFI-39 parameter, which refers to the port
4434 where build and error logs sent by the daemon should be written.
4437 Procedures that make RPCs all take a server object as their first
4440 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
4441 @cindex invalid store items
4442 Return @code{#t} when @var{path} designates a valid store item and
4443 @code{#f} otherwise (an invalid item may exist on disk but still be
4444 invalid, for instance because it is the result of an aborted or failed
4447 A @code{&nix-protocol-error} condition is raised if @var{path} is not
4448 prefixed by the store directory (@file{/gnu/store}).
4451 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
4452 Add @var{text} under file @var{name} in the store, and return its store
4453 path. @var{references} is the list of store paths referred to by the
4454 resulting store path.
4457 @deffn {Scheme Procedure} build-derivations @var{server} @var{derivations}
4458 Build @var{derivations} (a list of @code{<derivation>} objects or
4459 derivation paths), and return when the worker is done building them.
4460 Return @code{#t} on success.
4463 Note that the @code{(guix monads)} module provides a monad as well as
4464 monadic versions of the above procedures, with the goal of making it
4465 more convenient to work with code that accesses the store (@pxref{The
4469 @i{This section is currently incomplete.}
4472 @section Derivations
4475 Low-level build actions and the environment in which they are performed
4476 are represented by @dfn{derivations}. A derivation contains the
4477 following pieces of information:
4481 The outputs of the derivation---derivations produce at least one file or
4482 directory in the store, but may produce more.
4485 The inputs of the derivations, which may be other derivations or plain
4486 files in the store (patches, build scripts, etc.)
4489 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
4492 The file name of a build script in the store, along with the arguments
4496 A list of environment variables to be defined.
4500 @cindex derivation path
4501 Derivations allow clients of the daemon to communicate build actions to
4502 the store. They exist in two forms: as an in-memory representation,
4503 both on the client- and daemon-side, and as files in the store whose
4504 name end in @code{.drv}---these files are referred to as @dfn{derivation
4505 paths}. Derivations paths can be passed to the @code{build-derivations}
4506 procedure to perform the build actions they prescribe (@pxref{The
4509 @cindex fixed-output derivations
4510 Operations such as file downloads and version-control checkouts for
4511 which the expected content hash is known in advance are modeled as
4512 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
4513 of a fixed-output derivation are independent of its inputs---e.g., a
4514 source code download produces the same result regardless of the download
4515 method and tools being used.
4517 The @code{(guix derivations)} module provides a representation of
4518 derivations as Scheme objects, along with procedures to create and
4519 otherwise manipulate derivations. The lowest-level primitive to create
4520 a derivation is the @code{derivation} procedure:
4522 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
4523 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
4524 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
4525 [#:system (%current-system)] [#:references-graphs #f] @
4526 [#:allowed-references #f] [#:disallowed-references #f] @
4527 [#:leaked-env-vars #f] [#:local-build? #f] @
4528 [#:substitutable? #t]
4529 Build a derivation with the given arguments, and return the resulting
4530 @code{<derivation>} object.
4532 When @var{hash} and @var{hash-algo} are given, a
4533 @dfn{fixed-output derivation} is created---i.e., one whose result is
4534 known in advance, such as a file download. If, in addition,
4535 @var{recursive?} is true, then that fixed output may be an executable
4536 file or a directory and @var{hash} must be the hash of an archive
4537 containing this output.
4539 When @var{references-graphs} is true, it must be a list of file
4540 name/store path pairs. In that case, the reference graph of each store
4541 path is exported in the build environment in the corresponding file, in
4542 a simple text format.
4544 When @var{allowed-references} is true, it must be a list of store items
4545 or outputs that the derivation's output may refer to. Likewise,
4546 @var{disallowed-references}, if true, must be a list of things the
4547 outputs may @emph{not} refer to.
4549 When @var{leaked-env-vars} is true, it must be a list of strings
4550 denoting environment variables that are allowed to ``leak'' from the
4551 daemon's environment to the build environment. This is only applicable
4552 to fixed-output derivations---i.e., when @var{hash} is true. The main
4553 use is to allow variables such as @code{http_proxy} to be passed to
4554 derivations that download files.
4556 When @var{local-build?} is true, declare that the derivation is not a
4557 good candidate for offloading and should rather be built locally
4558 (@pxref{Daemon Offload Setup}). This is the case for small derivations
4559 where the costs of data transfers would outweigh the benefits.
4561 When @var{substitutable?} is false, declare that substitutes of the
4562 derivation's output should not be used (@pxref{Substitutes}). This is
4563 useful, for instance, when building packages that capture details of the
4564 host CPU instruction set.
4568 Here's an example with a shell script as its builder, assuming
4569 @var{store} is an open connection to the daemon, and @var{bash} points
4570 to a Bash executable in the store:
4573 (use-modules (guix utils)
4577 (let ((builder ; add the Bash script to the store
4578 (add-text-to-store store "my-builder.sh"
4579 "echo hello world > $out\n" '())))
4580 (derivation store "foo"
4581 bash `("-e" ,builder)
4582 #:inputs `((,bash) (,builder))
4583 #:env-vars '(("HOME" . "/homeless"))))
4584 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
4587 As can be guessed, this primitive is cumbersome to use directly. A
4588 better approach is to write build scripts in Scheme, of course! The
4589 best course of action for that is to write the build code as a
4590 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
4591 information, @pxref{G-Expressions}.
4593 Once upon a time, @code{gexp->derivation} did not exist and constructing
4594 derivations with build code written in Scheme was achieved with
4595 @code{build-expression->derivation}, documented below. This procedure
4596 is now deprecated in favor of the much nicer @code{gexp->derivation}.
4598 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
4599 @var{name} @var{exp} @
4600 [#:system (%current-system)] [#:inputs '()] @
4601 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
4602 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
4603 [#:references-graphs #f] [#:allowed-references #f] @
4604 [#:disallowed-references #f] @
4605 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
4606 Return a derivation that executes Scheme expression @var{exp} as a
4607 builder for derivation @var{name}. @var{inputs} must be a list of
4608 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
4609 @code{"out"} is assumed. @var{modules} is a list of names of Guile
4610 modules from the current search path to be copied in the store,
4611 compiled, and made available in the load path during the execution of
4612 @var{exp}---e.g., @code{((guix build utils) (guix build
4613 gnu-build-system))}.
4615 @var{exp} is evaluated in an environment where @code{%outputs} is bound
4616 to a list of output/path pairs, and where @code{%build-inputs} is bound
4617 to a list of string/output-path pairs made from @var{inputs}.
4618 Optionally, @var{env-vars} is a list of string pairs specifying the name
4619 and value of environment variables visible to the builder. The builder
4620 terminates by passing the result of @var{exp} to @code{exit}; thus, when
4621 @var{exp} returns @code{#f}, the build is considered to have failed.
4623 @var{exp} is built using @var{guile-for-build} (a derivation). When
4624 @var{guile-for-build} is omitted or is @code{#f}, the value of the
4625 @code{%guile-for-build} fluid is used instead.
4627 See the @code{derivation} procedure for the meaning of
4628 @var{references-graphs}, @var{allowed-references},
4629 @var{disallowed-references}, @var{local-build?}, and
4630 @var{substitutable?}.
4634 Here's an example of a single-output derivation that creates a directory
4635 containing one file:
4638 (let ((builder '(let ((out (assoc-ref %outputs "out")))
4639 (mkdir out) ; create /gnu/store/@dots{}-goo
4640 (call-with-output-file (string-append out "/test")
4642 (display '(hello guix) p))))))
4643 (build-expression->derivation store "goo" builder))
4645 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
4649 @node The Store Monad
4650 @section The Store Monad
4654 The procedures that operate on the store described in the previous
4655 sections all take an open connection to the build daemon as their first
4656 argument. Although the underlying model is functional, they either have
4657 side effects or depend on the current state of the store.
4659 The former is inconvenient: the connection to the build daemon has to be
4660 carried around in all those functions, making it impossible to compose
4661 functions that do not take that parameter with functions that do. The
4662 latter can be problematic: since store operations have side effects
4663 and/or depend on external state, they have to be properly sequenced.
4665 @cindex monadic values
4666 @cindex monadic functions
4667 This is where the @code{(guix monads)} module comes in. This module
4668 provides a framework for working with @dfn{monads}, and a particularly
4669 useful monad for our uses, the @dfn{store monad}. Monads are a
4670 construct that allows two things: associating ``context'' with values
4671 (in our case, the context is the store), and building sequences of
4672 computations (here computations include accesses to the store). Values
4673 in a monad---values that carry this additional context---are called
4674 @dfn{monadic values}; procedures that return such values are called
4675 @dfn{monadic procedures}.
4677 Consider this ``normal'' procedure:
4680 (define (sh-symlink store)
4681 ;; Return a derivation that symlinks the 'bash' executable.
4682 (let* ((drv (package-derivation store bash))
4683 (out (derivation->output-path drv))
4684 (sh (string-append out "/bin/bash")))
4685 (build-expression->derivation store "sh"
4686 `(symlink ,sh %output))))
4689 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
4690 as a monadic function:
4693 (define (sh-symlink)
4694 ;; Same, but return a monadic value.
4695 (mlet %store-monad ((drv (package->derivation bash)))
4696 (gexp->derivation "sh"
4697 #~(symlink (string-append #$drv "/bin/bash")
4701 There are several things to note in the second version: the @code{store}
4702 parameter is now implicit and is ``threaded'' in the calls to the
4703 @code{package->derivation} and @code{gexp->derivation} monadic
4704 procedures, and the monadic value returned by @code{package->derivation}
4705 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
4707 As it turns out, the call to @code{package->derivation} can even be
4708 omitted since it will take place implicitly, as we will see later
4709 (@pxref{G-Expressions}):
4712 (define (sh-symlink)
4713 (gexp->derivation "sh"
4714 #~(symlink (string-append #$bash "/bin/bash")
4719 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
4720 @c for the funny quote.
4721 Calling the monadic @code{sh-symlink} has no effect. As someone once
4722 said, ``you exit a monad like you exit a building on fire: by running''.
4723 So, to exit the monad and get the desired effect, one must use
4724 @code{run-with-store}:
4727 (run-with-store (open-connection) (sh-symlink))
4728 @result{} /gnu/store/...-sh-symlink
4731 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
4732 new ``meta-commands'' to make it easier to deal with monadic procedures:
4733 @code{run-in-store}, and @code{enter-store-monad}. The former is used
4734 to ``run'' a single monadic value through the store:
4737 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
4738 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
4741 The latter enters a recursive REPL, where all the return values are
4742 automatically run through the store:
4745 scheme@@(guile-user)> ,enter-store-monad
4746 store-monad@@(guile-user) [1]> (package->derivation hello)
4747 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
4748 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
4749 $3 = "/gnu/store/@dots{}-foo"
4750 store-monad@@(guile-user) [1]> ,q
4751 scheme@@(guile-user)>
4755 Note that non-monadic values cannot be returned in the
4756 @code{store-monad} REPL.
4758 The main syntactic forms to deal with monads in general are provided by
4759 the @code{(guix monads)} module and are described below.
4761 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
4762 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
4766 @deffn {Scheme Syntax} return @var{val}
4767 Return a monadic value that encapsulates @var{val}.
4770 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
4771 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
4772 procedures @var{mproc}@dots{}@footnote{This operation is commonly
4773 referred to as ``bind'', but that name denotes an unrelated procedure in
4774 Guile. Thus we use this somewhat cryptic symbol inherited from the
4775 Haskell language.}. There can be one @var{mproc} or several of them, as
4780 (with-monad %state-monad
4782 (lambda (x) (return (+ 1 x)))
4783 (lambda (x) (return (* 2 x)))))
4787 @result{} some-state
4791 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
4793 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
4795 Bind the variables @var{var} to the monadic values @var{mval} in
4796 @var{body}, which is a sequence of expressions. As with the bind
4797 operator, this can be thought of as ``unpacking'' the raw, non-monadic
4798 value ``contained'' in @var{mval} and making @var{var} refer to that
4799 raw, non-monadic value within the scope of the @var{body}. The form
4800 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
4801 @var{val}, as per @code{let}. The binding operations occur in sequence
4802 from left to right. The last expression of @var{body} must be a monadic
4803 expression, and its result will become the result of the @code{mlet} or
4804 @code{mlet*} when run in the @var{monad}.
4806 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
4807 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
4810 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
4811 Bind @var{mexp} and the following monadic expressions in sequence,
4812 returning the result of the last expression. Every expression in the
4813 sequence must be a monadic expression.
4815 This is akin to @code{mlet}, except that the return values of the
4816 monadic expressions are ignored. In that sense, it is analogous to
4817 @code{begin}, but applied to monadic expressions.
4820 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
4821 When @var{condition} is true, evaluate the sequence of monadic
4822 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
4823 @var{condition} is false, return @code{*unspecified*} in the current
4824 monad. Every expression in the sequence must be a monadic expression.
4827 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
4828 When @var{condition} is false, evaluate the sequence of monadic
4829 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
4830 @var{condition} is true, return @code{*unspecified*} in the current
4831 monad. Every expression in the sequence must be a monadic expression.
4835 The @code{(guix monads)} module provides the @dfn{state monad}, which
4836 allows an additional value---the state---to be @emph{threaded} through
4837 monadic procedure calls.
4839 @defvr {Scheme Variable} %state-monad
4840 The state monad. Procedures in the state monad can access and change
4841 the state that is threaded.
4843 Consider the example below. The @code{square} procedure returns a value
4844 in the state monad. It returns the square of its argument, but also
4845 increments the current state value:
4849 (mlet %state-monad ((count (current-state)))
4850 (mbegin %state-monad
4851 (set-current-state (+ 1 count))
4854 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
4859 When ``run'' through @var{%state-monad}, we obtain that additional state
4860 value, which is the number of @code{square} calls.
4863 @deffn {Monadic Procedure} current-state
4864 Return the current state as a monadic value.
4867 @deffn {Monadic Procedure} set-current-state @var{value}
4868 Set the current state to @var{value} and return the previous state as a
4872 @deffn {Monadic Procedure} state-push @var{value}
4873 Push @var{value} to the current state, which is assumed to be a list,
4874 and return the previous state as a monadic value.
4877 @deffn {Monadic Procedure} state-pop
4878 Pop a value from the current state and return it as a monadic value.
4879 The state is assumed to be a list.
4882 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
4883 Run monadic value @var{mval} starting with @var{state} as the initial
4884 state. Return two values: the resulting value, and the resulting state.
4887 The main interface to the store monad, provided by the @code{(guix
4888 store)} module, is as follows.
4890 @defvr {Scheme Variable} %store-monad
4891 The store monad---an alias for @var{%state-monad}.
4893 Values in the store monad encapsulate accesses to the store. When its
4894 effect is needed, a value of the store monad must be ``evaluated'' by
4895 passing it to the @code{run-with-store} procedure (see below.)
4898 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
4899 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
4900 open store connection.
4903 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
4904 Return as a monadic value the absolute file name in the store of the file
4905 containing @var{text}, a string. @var{references} is a list of store items that the
4906 resulting text file refers to; it defaults to the empty list.
4909 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
4910 [#:recursive? #t] [#:select? (const #t)]
4911 Return the name of @var{file} once interned in the store. Use
4912 @var{name} as its store name, or the basename of @var{file} if
4913 @var{name} is omitted.
4915 When @var{recursive?} is true, the contents of @var{file} are added
4916 recursively; if @var{file} designates a flat file and @var{recursive?}
4917 is true, its contents are added, and its permission bits are kept.
4919 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
4920 @var{stat})} for each directory entry, where @var{file} is the entry's
4921 absolute file name and @var{stat} is the result of @code{lstat}; exclude
4922 entries for which @var{select?} does not return true.
4924 The example below adds a file to the store, under two different names:
4927 (run-with-store (open-connection)
4928 (mlet %store-monad ((a (interned-file "README"))
4929 (b (interned-file "README" "LEGU-MIN")))
4930 (return (list a b))))
4932 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
4937 The @code{(guix packages)} module exports the following package-related
4940 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
4941 [#:system (%current-system)] [#:target #f] @
4944 value in the absolute file name of @var{file} within the @var{output}
4945 directory of @var{package}. When @var{file} is omitted, return the name
4946 of the @var{output} directory of @var{package}. When @var{target} is
4947 true, use it as a cross-compilation target triplet.
4950 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
4951 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
4952 @var{target} [@var{system}]
4953 Monadic version of @code{package-derivation} and
4954 @code{package-cross-derivation} (@pxref{Defining Packages}).
4959 @section G-Expressions
4961 @cindex G-expression
4962 @cindex build code quoting
4963 So we have ``derivations'', which represent a sequence of build actions
4964 to be performed to produce an item in the store (@pxref{Derivations}).
4965 These build actions are performed when asking the daemon to actually
4966 build the derivations; they are run by the daemon in a container
4967 (@pxref{Invoking guix-daemon}).
4969 @cindex strata of code
4970 It should come as no surprise that we like to write these build actions
4971 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
4972 code@footnote{The term @dfn{stratum} in this context was coined by
4973 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
4974 Kiselyov, who has written insightful
4975 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
4976 on this topic}, refers to this kind of code generation as
4977 @dfn{staging}.}: the ``host code''---code that defines packages, talks
4978 to the daemon, etc.---and the ``build code''---code that actually
4979 performs build actions, such as making directories, invoking
4980 @command{make}, etc.
4982 To describe a derivation and its build actions, one typically needs to
4983 embed build code inside host code. It boils down to manipulating build
4984 code as data, and the homoiconicity of Scheme---code has a direct
4985 representation as data---comes in handy for that. But we need more than
4986 the normal @code{quasiquote} mechanism in Scheme to construct build
4989 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
4990 S-expressions adapted to build expressions. G-expressions, or
4991 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
4992 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
4993 @code{#$}, and @code{#$@@}), which are comparable to
4994 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
4995 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
4996 GNU Guile Reference Manual}). However, there are major differences:
5000 Gexps are meant to be written to a file and run or manipulated by other
5004 When a high-level object such as a package or derivation is unquoted
5005 inside a gexp, the result is as if its output file name had been
5009 Gexps carry information about the packages or derivations they refer to,
5010 and these dependencies are automatically added as inputs to the build
5011 processes that use them.
5014 @cindex lowering, of high-level objects in gexps
5015 This mechanism is not limited to package and derivation
5016 objects: @dfn{compilers} able to ``lower'' other high-level objects to
5017 derivations or files in the store can be defined,
5018 such that these objects can also be inserted
5019 into gexps. For example, a useful type of high-level objects that can be
5020 inserted in a gexp is ``file-like objects'', which make it easy to
5021 add files to the store and to refer to them in
5022 derivations and such (see @code{local-file} and @code{plain-file}
5025 To illustrate the idea, here is an example of a gexp:
5032 (symlink (string-append #$coreutils "/bin/ls")
5036 This gexp can be passed to @code{gexp->derivation}; we obtain a
5037 derivation that builds a directory containing exactly one symlink to
5038 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
5041 (gexp->derivation "the-thing" build-exp)
5044 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
5045 substituted to the reference to the @var{coreutils} package in the
5046 actual build code, and @var{coreutils} is automatically made an input to
5047 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
5048 output)}) is replaced by a string containing the directory name of the
5049 output of the derivation.
5051 @cindex cross compilation
5052 In a cross-compilation context, it is useful to distinguish between
5053 references to the @emph{native} build of a package---that can run on the
5054 host---versus references to cross builds of a package. To that end, the
5055 @code{#+} plays the same role as @code{#$}, but is a reference to a
5056 native package build:
5059 (gexp->derivation "vi"
5062 (system* (string-append #+coreutils "/bin/ln")
5064 (string-append #$emacs "/bin/emacs")
5065 (string-append #$output "/bin/vi")))
5066 #:target "mips64el-linux-gnu")
5070 In the example above, the native build of @var{coreutils} is used, so
5071 that @command{ln} can actually run on the host; but then the
5072 cross-compiled build of @var{emacs} is referenced.
5074 @cindex imported modules, for gexps
5075 @findex with-imported-modules
5076 Another gexp feature is @dfn{imported modules}: sometimes you want to be
5077 able to use certain Guile modules from the ``host environment'' in the
5078 gexp, so those modules should be imported in the ``build environment''.
5079 The @code{with-imported-modules} form allows you to express that:
5082 (let ((build (with-imported-modules '((guix build utils))
5084 (use-modules (guix build utils))
5085 (mkdir-p (string-append #$output "/bin"))))))
5086 (gexp->derivation "empty-dir"
5089 (display "success!\n")
5094 In this example, the @code{(guix build utils)} module is automatically
5095 pulled into the isolated build environment of our gexp, such that
5096 @code{(use-modules (guix build utils))} works as expected.
5098 @cindex module closure
5099 @findex source-module-closure
5100 Usually you want the @emph{closure} of the module to be imported---i.e.,
5101 the module itself and all the modules it depends on---rather than just
5102 the module; failing to do that, attempts to use the module will fail
5103 because of missing dependent modules. The @code{source-module-closure}
5104 procedure computes the closure of a module by looking at its source file
5105 headers, which comes in handy in this case:
5108 (use-modules (guix modules)) ;for 'source-module-closure'
5110 (with-imported-modules (source-module-closure
5111 '((guix build utils)
5113 (gexp->derivation "something-with-vms"
5115 (use-modules (guix build utils)
5120 @cindex extensions, for gexps
5121 @findex with-extensions
5122 In the same vein, sometimes you want to import not just pure-Scheme
5123 modules, but also ``extensions'' such as Guile bindings to C libraries
5124 or other ``full-blown'' packages. Say you need the @code{guile-json}
5125 package available on the build side, here's how you would do it:
5128 (use-modules (gnu packages guile)) ;for 'guile-json'
5130 (with-extensions (list guile-json)
5131 (gexp->derivation "something-with-json"
5133 (use-modules (json))
5137 The syntactic form to construct gexps is summarized below.
5139 @deffn {Scheme Syntax} #~@var{exp}
5140 @deffnx {Scheme Syntax} (gexp @var{exp})
5141 Return a G-expression containing @var{exp}. @var{exp} may contain one
5142 or more of the following forms:
5146 @itemx (ungexp @var{obj})
5147 Introduce a reference to @var{obj}. @var{obj} may have one of the
5148 supported types, for example a package or a
5149 derivation, in which case the @code{ungexp} form is replaced by its
5150 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
5152 If @var{obj} is a list, it is traversed and references to supported
5153 objects are substituted similarly.
5155 If @var{obj} is another gexp, its contents are inserted and its
5156 dependencies are added to those of the containing gexp.
5158 If @var{obj} is another kind of object, it is inserted as is.
5160 @item #$@var{obj}:@var{output}
5161 @itemx (ungexp @var{obj} @var{output})
5162 This is like the form above, but referring explicitly to the
5163 @var{output} of @var{obj}---this is useful when @var{obj} produces
5164 multiple outputs (@pxref{Packages with Multiple Outputs}).
5167 @itemx #+@var{obj}:output
5168 @itemx (ungexp-native @var{obj})
5169 @itemx (ungexp-native @var{obj} @var{output})
5170 Same as @code{ungexp}, but produces a reference to the @emph{native}
5171 build of @var{obj} when used in a cross compilation context.
5173 @item #$output[:@var{output}]
5174 @itemx (ungexp output [@var{output}])
5175 Insert a reference to derivation output @var{output}, or to the main
5176 output when @var{output} is omitted.
5178 This only makes sense for gexps passed to @code{gexp->derivation}.
5181 @itemx (ungexp-splicing @var{lst})
5182 Like the above, but splices the contents of @var{lst} inside the
5186 @itemx (ungexp-native-splicing @var{lst})
5187 Like the above, but refers to native builds of the objects listed in
5192 G-expressions created by @code{gexp} or @code{#~} are run-time objects
5193 of the @code{gexp?} type (see below.)
5196 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
5197 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
5198 in their execution environment.
5200 Each item in @var{modules} can be the name of a module, such as
5201 @code{(guix build utils)}, or it can be a module name, followed by an
5202 arrow, followed by a file-like object:
5205 `((guix build utils)
5207 ((guix config) => ,(scheme-file "config.scm"
5208 #~(define-module @dots{}))))
5212 In the example above, the first two modules are taken from the search
5213 path, and the last one is created from the given file-like object.
5215 This form has @emph{lexical} scope: it has an effect on the gexps
5216 directly defined in @var{body}@dots{}, but not on those defined, say, in
5217 procedures called from @var{body}@dots{}.
5220 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
5221 Mark the gexps defined in @var{body}@dots{} as requiring
5222 @var{extensions} in their build and execution environment.
5223 @var{extensions} is typically a list of package objects such as those
5224 defined in the @code{(gnu packages guile)} module.
5226 Concretely, the packages listed in @var{extensions} are added to the
5227 load path while compiling imported modules in @var{body}@dots{}; they
5228 are also added to the load path of the gexp returned by
5232 @deffn {Scheme Procedure} gexp? @var{obj}
5233 Return @code{#t} if @var{obj} is a G-expression.
5236 G-expressions are meant to be written to disk, either as code building
5237 some derivation, or as plain files in the store. The monadic procedures
5238 below allow you to do that (@pxref{The Store Monad}, for more
5239 information about monads.)
5241 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
5242 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
5243 [#:hash #f] [#:hash-algo #f] @
5244 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
5245 [#:module-path @var{%load-path}] @
5246 [#:effective-version "2.2"] @
5247 [#:references-graphs #f] [#:allowed-references #f] @
5248 [#:disallowed-references #f] @
5249 [#:leaked-env-vars #f] @
5250 [#:script-name (string-append @var{name} "-builder")] @
5251 [#:deprecation-warnings #f] @
5252 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
5253 Return a derivation @var{name} that runs @var{exp} (a gexp) with
5254 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
5255 stored in a file called @var{script-name}. When @var{target} is true,
5256 it is used as the cross-compilation target triplet for packages referred
5259 @var{modules} is deprecated in favor of @code{with-imported-modules}.
5261 make @var{modules} available in the evaluation context of @var{exp};
5262 @var{modules} is a list of names of Guile modules searched in
5263 @var{module-path} to be copied in the store, compiled, and made available in
5264 the load path during the execution of @var{exp}---e.g., @code{((guix
5265 build utils) (guix build gnu-build-system))}.
5267 @var{effective-version} determines the string to use when adding extensions of
5268 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
5270 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
5273 When @var{references-graphs} is true, it must be a list of tuples of one of the
5277 (@var{file-name} @var{package})
5278 (@var{file-name} @var{package} @var{output})
5279 (@var{file-name} @var{derivation})
5280 (@var{file-name} @var{derivation} @var{output})
5281 (@var{file-name} @var{store-item})
5284 The right-hand-side of each element of @var{references-graphs} is automatically made
5285 an input of the build process of @var{exp}. In the build environment, each
5286 @var{file-name} contains the reference graph of the corresponding item, in a simple
5289 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
5290 In the latter case, the list denotes store items that the result is allowed to
5291 refer to. Any reference to another store item will lead to a build error.
5292 Similarly for @var{disallowed-references}, which can list items that must not be
5293 referenced by the outputs.
5295 @var{deprecation-warnings} determines whether to show deprecation warnings while
5296 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
5298 The other arguments are as for @code{derivation} (@pxref{Derivations}).
5301 @cindex file-like objects
5302 The @code{local-file}, @code{plain-file}, @code{computed-file},
5303 @code{program-file}, and @code{scheme-file} procedures below return
5304 @dfn{file-like objects}. That is, when unquoted in a G-expression,
5305 these objects lead to a file in the store. Consider this G-expression:
5308 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
5309 #$(local-file "/tmp/my-nscd.conf"))
5312 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
5313 to the store. Once expanded, for instance @i{via}
5314 @code{gexp->derivation}, the G-expression refers to that copy under
5315 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
5316 does not have any effect on what the G-expression does.
5317 @code{plain-file} can be used similarly; it differs in that the file
5318 content is directly passed as a string.
5320 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
5321 [#:recursive? #f] [#:select? (const #t)]
5322 Return an object representing local file @var{file} to add to the store; this
5323 object can be used in a gexp. If @var{file} is a relative file name, it is looked
5324 up relative to the source file where this form appears. @var{file} will be added to
5325 the store under @var{name}--by default the base name of @var{file}.
5327 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
5328 designates a flat file and @var{recursive?} is true, its contents are added, and its
5329 permission bits are kept.
5331 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
5332 @var{stat})} for each directory entry, where @var{file} is the entry's
5333 absolute file name and @var{stat} is the result of @code{lstat}; exclude
5334 entries for which @var{select?} does not return true.
5336 This is the declarative counterpart of the @code{interned-file} monadic
5337 procedure (@pxref{The Store Monad, @code{interned-file}}).
5340 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
5341 Return an object representing a text file called @var{name} with the given
5342 @var{content} (a string) to be added to the store.
5344 This is the declarative counterpart of @code{text-file}.
5347 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
5348 [#:options '(#:local-build? #t)]
5349 Return an object representing the store item @var{name}, a file or
5350 directory computed by @var{gexp}. @var{options}
5351 is a list of additional arguments to pass to @code{gexp->derivation}.
5353 This is the declarative counterpart of @code{gexp->derivation}.
5356 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
5357 [#:guile (default-guile)] [#:module-path %load-path]
5358 Return an executable script @var{name} that runs @var{exp} using
5359 @var{guile}, with @var{exp}'s imported modules in its search path.
5360 Look up @var{exp}'s modules in @var{module-path}.
5362 The example below builds a script that simply invokes the @command{ls}
5366 (use-modules (guix gexp) (gnu packages base))
5368 (gexp->script "list-files"
5369 #~(execl #$(file-append coreutils "/bin/ls")
5373 When ``running'' it through the store (@pxref{The Store Monad,
5374 @code{run-with-store}}), we obtain a derivation that produces an
5375 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
5378 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
5380 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
5384 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
5385 [#:guile #f] [#:module-path %load-path]
5386 Return an object representing the executable store item @var{name} that
5387 runs @var{gexp}. @var{guile} is the Guile package used to execute that
5388 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
5390 This is the declarative counterpart of @code{gexp->script}.
5393 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
5394 [#:set-load-path? #t] [#:module-path %load-path] @
5396 [#:guile (default-guile)]
5397 Return a derivation that builds a file @var{name} containing @var{exp}.
5398 When @var{splice?} is true, @var{exp} is considered to be a list of
5399 expressions that will be spliced in the resulting file.
5401 When @var{set-load-path?} is true, emit code in the resulting file to
5402 set @code{%load-path} and @code{%load-compiled-path} to honor
5403 @var{exp}'s imported modules. Look up @var{exp}'s modules in
5406 The resulting file holds references to all the dependencies of @var{exp}
5407 or a subset thereof.
5410 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
5411 Return an object representing the Scheme file @var{name} that contains
5414 This is the declarative counterpart of @code{gexp->file}.
5417 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
5418 Return as a monadic value a derivation that builds a text file
5419 containing all of @var{text}. @var{text} may list, in addition to
5420 strings, objects of any type that can be used in a gexp: packages,
5421 derivations, local file objects, etc. The resulting store file holds
5422 references to all these.
5424 This variant should be preferred over @code{text-file} anytime the file
5425 to create will reference items from the store. This is typically the
5426 case when building a configuration file that embeds store file names,
5430 (define (profile.sh)
5431 ;; Return the name of a shell script in the store that
5432 ;; initializes the 'PATH' environment variable.
5433 (text-file* "profile.sh"
5434 "export PATH=" coreutils "/bin:"
5435 grep "/bin:" sed "/bin\n"))
5438 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
5439 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
5440 preventing them from being garbage-collected during its lifetime.
5443 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
5444 Return an object representing store file @var{name} containing
5445 @var{text}. @var{text} is a sequence of strings and file-like objects,
5449 (mixed-text-file "profile"
5450 "export PATH=" coreutils "/bin:" grep "/bin")
5453 This is the declarative counterpart of @code{text-file*}.
5456 @deffn {Scheme Procedure} file-union @var{name} @var{files}
5457 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
5458 Each item in @var{files} must be a two-element list where the first element is the
5459 file name to use in the new directory, and the second element is a gexp
5460 denoting the target file. Here's an example:
5464 `(("hosts" ,(plain-file "hosts"
5465 "127.0.0.1 localhost"))
5466 ("bashrc" ,(plain-file "bashrc"
5467 "alias ls='ls --color'"))))
5470 This yields an @code{etc} directory containing these two files.
5473 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
5474 Return a directory that is the union of @var{things}, where @var{things} is a list of
5475 file-like objects denoting directories. For example:
5478 (directory-union "guile+emacs" (list guile emacs))
5481 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
5484 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
5485 Return a file-like object that expands to the concatenation of @var{obj}
5486 and @var{suffix}, where @var{obj} is a lowerable object and each
5487 @var{suffix} is a string.
5489 As an example, consider this gexp:
5492 (gexp->script "run-uname"
5493 #~(system* #$(file-append coreutils
5497 The same effect could be achieved with:
5500 (gexp->script "run-uname"
5501 #~(system* (string-append #$coreutils
5505 There is one difference though: in the @code{file-append} case, the
5506 resulting script contains the absolute file name as a string, whereas in
5507 the second case, the resulting script contains a @code{(string-append
5508 @dots{})} expression to construct the file name @emph{at run time}.
5512 Of course, in addition to gexps embedded in ``host'' code, there are
5513 also modules containing build tools. To make it clear that they are
5514 meant to be used in the build stratum, these modules are kept in the
5515 @code{(guix build @dots{})} name space.
5517 @cindex lowering, of high-level objects in gexps
5518 Internally, high-level objects are @dfn{lowered}, using their compiler,
5519 to either derivations or store items. For instance, lowering a package
5520 yields a derivation, and lowering a @code{plain-file} yields a store
5521 item. This is achieved using the @code{lower-object} monadic procedure.
5523 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
5525 Return as a value in @var{%store-monad} the derivation or store item
5526 corresponding to @var{obj} for @var{system}, cross-compiling for
5527 @var{target} if @var{target} is true. @var{obj} must be an object that
5528 has an associated gexp compiler, such as a @code{<package>}.
5532 @c *********************************************************************
5536 This section describes Guix command-line utilities. Some of them are
5537 primarily targeted at developers and users who write new package
5538 definitions, while others are more generally useful. They complement
5539 the Scheme programming interface of Guix in a convenient way.
5542 * Invoking guix build:: Building packages from the command line.
5543 * Invoking guix edit:: Editing package definitions.
5544 * Invoking guix download:: Downloading a file and printing its hash.
5545 * Invoking guix hash:: Computing the cryptographic hash of a file.
5546 * Invoking guix import:: Importing package definitions.
5547 * Invoking guix refresh:: Updating package definitions.
5548 * Invoking guix lint:: Finding errors in package definitions.
5549 * Invoking guix size:: Profiling disk usage.
5550 * Invoking guix graph:: Visualizing the graph of packages.
5551 * Invoking guix environment:: Setting up development environments.
5552 * Invoking guix publish:: Sharing substitutes.
5553 * Invoking guix challenge:: Challenging substitute servers.
5554 * Invoking guix copy:: Copying to and from a remote store.
5555 * Invoking guix container:: Process isolation.
5556 * Invoking guix weather:: Assessing substitute availability.
5559 @node Invoking guix build
5560 @section Invoking @command{guix build}
5562 @cindex package building
5563 @cindex @command{guix build}
5564 The @command{guix build} command builds packages or derivations and
5565 their dependencies, and prints the resulting store paths. Note that it
5566 does not modify the user's profile---this is the job of the
5567 @command{guix package} command (@pxref{Invoking guix package}). Thus,
5568 it is mainly useful for distribution developers.
5570 The general syntax is:
5573 guix build @var{options} @var{package-or-derivation}@dots{}
5576 As an example, the following command builds the latest versions of Emacs
5577 and of Guile, displays their build logs, and finally displays the
5578 resulting directories:
5581 guix build emacs guile
5584 Similarly, the following command builds all the available packages:
5587 guix build --quiet --keep-going \
5588 `guix package -A | cut -f1,2 --output-delimiter=@@`
5591 @var{package-or-derivation} may be either the name of a package found in
5592 the software distribution such as @code{coreutils} or
5593 @code{coreutils@@8.20}, or a derivation such as
5594 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
5595 package with the corresponding name (and optionally version) is searched
5596 for among the GNU distribution modules (@pxref{Package Modules}).
5598 Alternatively, the @code{--expression} option may be used to specify a
5599 Scheme expression that evaluates to a package; this is useful when
5600 disambiguating among several same-named packages or package variants is
5603 There may be zero or more @var{options}. The available options are
5604 described in the subsections below.
5607 * Common Build Options:: Build options for most commands.
5608 * Package Transformation Options:: Creating variants of packages.
5609 * Additional Build Options:: Options specific to 'guix build'.
5610 * Debugging Build Failures:: Real life packaging experience.
5613 @node Common Build Options
5614 @subsection Common Build Options
5616 A number of options that control the build process are common to
5617 @command{guix build} and other commands that can spawn builds, such as
5618 @command{guix package} or @command{guix archive}. These are the
5623 @item --load-path=@var{directory}
5624 @itemx -L @var{directory}
5625 Add @var{directory} to the front of the package module search path
5626 (@pxref{Package Modules}).
5628 This allows users to define their own packages and make them visible to
5629 the command-line tools.
5633 Keep the build tree of failed builds. Thus, if a build fails, its build
5634 tree is kept under @file{/tmp}, in a directory whose name is shown at
5635 the end of the build log. This is useful when debugging build issues.
5636 @xref{Debugging Build Failures}, for tips and tricks on how to debug
5641 Keep going when some of the derivations fail to build; return only once
5642 all the builds have either completed or failed.
5644 The default behavior is to stop as soon as one of the specified
5645 derivations has failed.
5649 Do not build the derivations.
5651 @anchor{fallback-option}
5653 When substituting a pre-built binary fails, fall back to building
5654 packages locally (@pxref{Substitution Failure}).
5656 @item --substitute-urls=@var{urls}
5657 @anchor{client-substitute-urls}
5658 Consider @var{urls} the whitespace-separated list of substitute source
5659 URLs, overriding the default list of URLs of @command{guix-daemon}
5660 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
5662 This means that substitutes may be downloaded from @var{urls}, provided
5663 they are signed by a key authorized by the system administrator
5664 (@pxref{Substitutes}).
5666 When @var{urls} is the empty string, substitutes are effectively
5669 @item --no-substitutes
5670 Do not use substitutes for build products. That is, always build things
5671 locally instead of allowing downloads of pre-built binaries
5672 (@pxref{Substitutes}).
5675 Do not ``graft'' packages. In practice, this means that package updates
5676 available as grafts are not applied. @xref{Security Updates}, for more
5677 information on grafts.
5679 @item --rounds=@var{n}
5680 Build each derivation @var{n} times in a row, and raise an error if
5681 consecutive build results are not bit-for-bit identical.
5683 This is a useful way to detect non-deterministic builds processes.
5684 Non-deterministic build processes are a problem because they make it
5685 practically impossible for users to @emph{verify} whether third-party
5686 binaries are genuine. @xref{Invoking guix challenge}, for more.
5688 Note that, currently, the differing build results are not kept around,
5689 so you will have to manually investigate in case of an error---e.g., by
5690 stashing one of the build results with @code{guix archive --export}
5691 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
5694 @item --no-build-hook
5695 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
5696 (@pxref{Daemon Offload Setup}). That is, always build things locally
5697 instead of offloading builds to remote machines.
5699 @item --max-silent-time=@var{seconds}
5700 When the build or substitution process remains silent for more than
5701 @var{seconds}, terminate it and report a build failure.
5703 By default, the daemon's setting is honored (@pxref{Invoking
5704 guix-daemon, @code{--max-silent-time}}).
5706 @item --timeout=@var{seconds}
5707 Likewise, when the build or substitution process lasts for more than
5708 @var{seconds}, terminate it and report a build failure.
5710 By default, the daemon's setting is honored (@pxref{Invoking
5711 guix-daemon, @code{--timeout}}).
5713 @item --verbosity=@var{level}
5714 Use the given verbosity level. @var{level} must be an integer between 0
5715 and 5; higher means more verbose output. Setting a level of 4 or more
5716 may be helpful when debugging setup issues with the build daemon.
5718 @item --cores=@var{n}
5720 Allow the use of up to @var{n} CPU cores for the build. The special
5721 value @code{0} means to use as many CPU cores as available.
5723 @item --max-jobs=@var{n}
5725 Allow at most @var{n} build jobs in parallel. @xref{Invoking
5726 guix-daemon, @code{--max-jobs}}, for details about this option and the
5727 equivalent @command{guix-daemon} option.
5731 Behind the scenes, @command{guix build} is essentially an interface to
5732 the @code{package-derivation} procedure of the @code{(guix packages)}
5733 module, and to the @code{build-derivations} procedure of the @code{(guix
5734 derivations)} module.
5736 In addition to options explicitly passed on the command line,
5737 @command{guix build} and other @command{guix} commands that support
5738 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
5740 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
5741 Users can define this variable to a list of command line options that
5742 will automatically be used by @command{guix build} and other
5743 @command{guix} commands that can perform builds, as in the example
5747 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
5750 These options are parsed independently, and the result is appended to
5751 the parsed command-line options.
5755 @node Package Transformation Options
5756 @subsection Package Transformation Options
5758 @cindex package variants
5759 Another set of command-line options supported by @command{guix build}
5760 and also @command{guix package} are @dfn{package transformation
5761 options}. These are options that make it possible to define @dfn{package
5762 variants}---for instance, packages built from different source code.
5763 This is a convenient way to create customized packages on the fly
5764 without having to type in the definitions of package variants
5765 (@pxref{Defining Packages}).
5769 @item --with-source=@var{source}
5770 @itemx --with-source=@var{package}=@var{source}
5771 @itemx --with-source=@var{package}@@@var{version}=@var{source}
5772 Use @var{source} as the source of @var{package}, and @var{version} as
5774 @var{source} must be a file name or a URL, as for @command{guix
5775 download} (@pxref{Invoking guix download}).
5777 When @var{package} is omitted,
5778 it is taken to be the package name specified on the
5779 command line that matches the base of @var{source}---e.g.,
5780 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
5781 package is @code{guile}.
5783 Likewise, when @var{version} is omitted, the version string is inferred from
5784 @var{source}; in the previous example, it is @code{2.0.10}.
5786 This option allows users to try out versions of packages other than the
5787 one provided by the distribution. The example below downloads
5788 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
5789 the @code{ed} package:
5792 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
5795 As a developer, @code{--with-source} makes it easy to test release
5799 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
5802 @dots{} or to build from a checkout in a pristine environment:
5805 $ git clone git://git.sv.gnu.org/guix.git
5806 $ guix build guix --with-source=guix@@1.0=./guix
5809 @item --with-input=@var{package}=@var{replacement}
5810 Replace dependency on @var{package} by a dependency on
5811 @var{replacement}. @var{package} must be a package name, and
5812 @var{replacement} must be a package specification such as @code{guile}
5813 or @code{guile@@1.8}.
5815 For instance, the following command builds Guix, but replaces its
5816 dependency on the current stable version of Guile with a dependency on
5817 the legacy version of Guile, @code{guile@@2.0}:
5820 guix build --with-input=guile=guile@@2.0 guix
5823 This is a recursive, deep replacement. So in this example, both
5824 @code{guix} and its dependency @code{guile-json} (which also depends on
5825 @code{guile}) get rebuilt against @code{guile@@2.0}.
5827 This is implemented using the @code{package-input-rewriting} Scheme
5828 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
5830 @item --with-graft=@var{package}=@var{replacement}
5831 This is similar to @code{--with-input} but with an important difference:
5832 instead of rebuilding the whole dependency chain, @var{replacement} is
5833 built and then @dfn{grafted} onto the binaries that were initially
5834 referring to @var{package}. @xref{Security Updates}, for more
5835 information on grafts.
5837 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
5838 and all its dependencies, replacing references to the version of GnuTLS
5839 they currently refer to:
5842 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
5845 This has the advantage of being much faster than rebuilding everything.
5846 But there is a caveat: it works if and only if @var{package} and
5847 @var{replacement} are strictly compatible---for example, if they provide
5848 a library, the application binary interface (ABI) of those libraries
5849 must be compatible. If @var{replacement} is somehow incompatible with
5850 @var{package}, then the resulting package may be unusable. Use with
5855 @node Additional Build Options
5856 @subsection Additional Build Options
5858 The command-line options presented below are specific to @command{guix
5865 Build quietly, without displaying the build log. Upon completion, the
5866 build log is kept in @file{/var} (or similar) and can always be
5867 retrieved using the @option{--log-file} option.
5869 @item --file=@var{file}
5870 @itemx -f @var{file}
5872 Build the package or derivation that the code within @var{file}
5875 As an example, @var{file} might contain a package definition like this
5876 (@pxref{Defining Packages}):
5879 @verbatiminclude package-hello.scm
5882 @item --expression=@var{expr}
5883 @itemx -e @var{expr}
5884 Build the package or derivation @var{expr} evaluates to.
5886 For example, @var{expr} may be @code{(@@ (gnu packages guile)
5887 guile-1.8)}, which unambiguously designates this specific variant of
5888 version 1.8 of Guile.
5890 Alternatively, @var{expr} may be a G-expression, in which case it is used
5891 as a build program passed to @code{gexp->derivation}
5892 (@pxref{G-Expressions}).
5894 Lastly, @var{expr} may refer to a zero-argument monadic procedure
5895 (@pxref{The Store Monad}). The procedure must return a derivation as a
5896 monadic value, which is then passed through @code{run-with-store}.
5900 Build the source derivations of the packages, rather than the packages
5903 For instance, @code{guix build -S gcc} returns something like
5904 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
5907 The returned source tarball is the result of applying any patches and
5908 code snippets specified in the package @code{origin} (@pxref{Defining
5912 Fetch and return the source of @var{package-or-derivation} and all their
5913 dependencies, recursively. This is a handy way to obtain a local copy
5914 of all the source code needed to build @var{packages}, allowing you to
5915 eventually build them even without network access. It is an extension
5916 of the @code{--source} option and can accept one of the following
5917 optional argument values:
5921 This value causes the @code{--sources} option to behave in the same way
5922 as the @code{--source} option.
5925 Build the source derivations of all packages, including any source that
5926 might be listed as @code{inputs}. This is the default value.
5929 $ guix build --sources tzdata
5930 The following derivations will be built:
5931 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
5932 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
5936 Build the source derivations of all packages, as well of all transitive
5937 inputs to the packages. This can be used e.g. to
5938 prefetch package source for later offline building.
5941 $ guix build --sources=transitive tzdata
5942 The following derivations will be built:
5943 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
5944 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
5945 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
5946 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
5947 /gnu/store/@dots{}-make-4.1.tar.xz.drv
5948 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
5954 @item --system=@var{system}
5955 @itemx -s @var{system}
5956 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5957 the system type of the build host.
5960 The @code{--system} flag is for @emph{native} compilation and must not
5961 be confused with cross-compilation. See @code{--target} below for
5962 information on cross-compilation.
5965 An example use of this is on Linux-based systems, which can emulate
5966 different personalities. For instance, passing
5967 @code{--system=i686-linux} on an @code{x86_64-linux} system or
5968 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
5969 to build packages in a complete 32-bit environment.
5972 Building for an @code{armhf-linux} system is unconditionally enabled on
5973 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
5974 allow for this functionality, notably the ThunderX.
5977 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
5978 is enabled (@pxref{Virtualization Services,
5979 @code{qemu-binfmt-service-type}}), you can build for any system for
5980 which a QEMU @code{binfmt_misc} handler is installed.
5982 Builds for a system other than that of the machine you are using can
5983 also be offloaded to a remote machine of the right architecture.
5984 @xref{Daemon Offload Setup}, for more information on offloading.
5986 @item --target=@var{triplet}
5987 @cindex cross-compilation
5988 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5989 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
5990 configuration triplets,, autoconf, Autoconf}).
5992 @anchor{build-check}
5994 @cindex determinism, checking
5995 @cindex reproducibility, checking
5996 Rebuild @var{package-or-derivation}, which are already available in the
5997 store, and raise an error if the build results are not bit-for-bit
6000 This mechanism allows you to check whether previously installed
6001 substitutes are genuine (@pxref{Substitutes}), or whether the build result
6002 of a package is deterministic. @xref{Invoking guix challenge}, for more
6003 background information and tools.
6005 When used in conjunction with @option{--keep-failed}, the differing
6006 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
6007 This makes it easy to look for differences between the two results.
6010 @cindex repairing store items
6011 @cindex corruption, recovering from
6012 Attempt to repair the specified store items, if they are corrupt, by
6013 re-downloading or rebuilding them.
6015 This operation is not atomic and thus restricted to @code{root}.
6019 Return the derivation paths, not the output paths, of the given
6022 @item --root=@var{file}
6023 @itemx -r @var{file}
6024 @cindex GC roots, adding
6025 @cindex garbage collector roots, adding
6026 Make @var{file} a symlink to the result, and register it as a garbage
6029 Consequently, the results of this @command{guix build} invocation are
6030 protected from garbage collection until @var{file} is removed. When
6031 that option is omitted, build results are eligible for garbage
6032 collection as soon as the build completes. @xref{Invoking guix gc}, for
6036 @cindex build logs, access
6037 Return the build log file names or URLs for the given
6038 @var{package-or-derivation}, or raise an error if build logs are
6041 This works regardless of how packages or derivations are specified. For
6042 instance, the following invocations are equivalent:
6045 guix build --log-file `guix build -d guile`
6046 guix build --log-file `guix build guile`
6047 guix build --log-file guile
6048 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
6051 If a log is unavailable locally, and unless @code{--no-substitutes} is
6052 passed, the command looks for a corresponding log on one of the
6053 substitute servers (as specified with @code{--substitute-urls}.)
6055 So for instance, imagine you want to see the build log of GDB on MIPS,
6056 but you are actually on an @code{x86_64} machine:
6059 $ guix build --log-file gdb -s mips64el-linux
6060 https://hydra.gnu.org/log/@dots{}-gdb-7.10
6063 You can freely access a huge library of build logs!
6066 @node Debugging Build Failures
6067 @subsection Debugging Build Failures
6069 @cindex build failures, debugging
6070 When defining a new package (@pxref{Defining Packages}), you will
6071 probably find yourself spending some time debugging and tweaking the
6072 build until it succeeds. To do that, you need to operate the build
6073 commands yourself in an environment as close as possible to the one the
6076 To that end, the first thing to do is to use the @option{--keep-failed}
6077 or @option{-K} option of @command{guix build}, which will keep the
6078 failed build tree in @file{/tmp} or whatever directory you specified as
6079 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
6081 From there on, you can @command{cd} to the failed build tree and source
6082 the @file{environment-variables} file, which contains all the
6083 environment variable definitions that were in place when the build
6084 failed. So let's say you're debugging a build failure in package
6085 @code{foo}; a typical session would look like this:
6089 @dots{} @i{build fails}
6090 $ cd /tmp/guix-build-foo.drv-0
6091 $ source ./environment-variables
6095 Now, you can invoke commands as if you were the daemon (almost) and
6096 troubleshoot your build process.
6098 Sometimes it happens that, for example, a package's tests pass when you
6099 run them manually but they fail when the daemon runs them. This can
6100 happen because the daemon runs builds in containers where, unlike in our
6101 environment above, network access is missing, @file{/bin/sh} does not
6102 exist, etc. (@pxref{Build Environment Setup}).
6104 In such cases, you may need to run inspect the build process from within
6105 a container similar to the one the build daemon creates:
6110 $ cd /tmp/guix-build-foo.drv-0
6111 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
6112 [env]# source ./environment-variables
6116 Here, @command{guix environment -C} creates a container and spawns a new
6117 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
6118 strace gdb} part adds the @command{strace} and @command{gdb} commands to
6119 the container, which would may find handy while debugging. The
6120 @option{--no-grafts} option makes sure we get the exact same
6121 environment, with ungrafted packages (@pxref{Security Updates}, for more
6124 To get closer to a container like that used by the build daemon, we can
6125 remove @file{/bin/sh}:
6131 (Don't worry, this is harmless: this is all happening in the throw-away
6132 container created by @command{guix environment}.)
6134 The @command{strace} command is probably not in the search path, but we
6138 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
6141 In this way, not only you will have reproduced the environment variables
6142 the daemon uses, you will also be running the build process in a container
6143 similar to the one the daemon uses.
6146 @node Invoking guix edit
6147 @section Invoking @command{guix edit}
6149 @cindex @command{guix edit}
6150 @cindex package definition, editing
6151 So many packages, so many source files! The @command{guix edit} command
6152 facilitates the life of users and packagers by pointing their editor at
6153 the source file containing the definition of the specified packages.
6157 guix edit gcc@@4.9 vim
6161 launches the program specified in the @code{VISUAL} or in the
6162 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
6165 If you are using a Guix Git checkout (@pxref{Building from Git}), or
6166 have created your own packages on @code{GUIX_PACKAGE_PATH}
6167 (@pxref{Defining Packages}), you will be able to edit the package
6168 recipes. Otherwise, you will be able to examine the read-only recipes
6169 for packages currently in the store.
6172 @node Invoking guix download
6173 @section Invoking @command{guix download}
6175 @cindex @command{guix download}
6176 @cindex downloading package sources
6177 When writing a package definition, developers typically need to download
6178 a source tarball, compute its SHA256 hash, and write that
6179 hash in the package definition (@pxref{Defining Packages}). The
6180 @command{guix download} tool helps with this task: it downloads a file
6181 from the given URI, adds it to the store, and prints both its file name
6182 in the store and its SHA256 hash.
6184 The fact that the downloaded file is added to the store saves bandwidth:
6185 when the developer eventually tries to build the newly defined package
6186 with @command{guix build}, the source tarball will not have to be
6187 downloaded again because it is already in the store. It is also a
6188 convenient way to temporarily stash files, which may be deleted
6189 eventually (@pxref{Invoking guix gc}).
6191 The @command{guix download} command supports the same URIs as used in
6192 package definitions. In particular, it supports @code{mirror://} URIs.
6193 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
6194 Guile bindings for GnuTLS are available in the user's environment; when
6195 they are not available, an error is raised. @xref{Guile Preparations,
6196 how to install the GnuTLS bindings for Guile,, gnutls-guile,
6197 GnuTLS-Guile}, for more information.
6199 @command{guix download} verifies HTTPS server certificates by loading
6200 the certificates of X.509 authorities from the directory pointed to by
6201 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
6202 Certificates}), unless @option{--no-check-certificate} is used.
6204 The following options are available:
6207 @item --format=@var{fmt}
6209 Write the hash in the format specified by @var{fmt}. For more
6210 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
6212 @item --no-check-certificate
6213 Do not validate the X.509 certificates of HTTPS servers.
6215 When using this option, you have @emph{absolutely no guarantee} that you
6216 are communicating with the authentic server responsible for the given
6217 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
6219 @item --output=@var{file}
6220 @itemx -o @var{file}
6221 Save the downloaded file to @var{file} instead of adding it to the
6225 @node Invoking guix hash
6226 @section Invoking @command{guix hash}
6228 @cindex @command{guix hash}
6229 The @command{guix hash} command computes the SHA256 hash of a file.
6230 It is primarily a convenience tool for anyone contributing to the
6231 distribution: it computes the cryptographic hash of a file, which can be
6232 used in the definition of a package (@pxref{Defining Packages}).
6234 The general syntax is:
6237 guix hash @var{option} @var{file}
6240 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
6241 hash of data read from standard input. @command{guix hash} has the
6246 @item --format=@var{fmt}
6248 Write the hash in the format specified by @var{fmt}.
6250 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
6251 (@code{hex} and @code{hexadecimal} can be used as well).
6253 If the @option{--format} option is not specified, @command{guix hash}
6254 will output the hash in @code{nix-base32}. This representation is used
6255 in the definitions of packages.
6259 Compute the hash on @var{file} recursively.
6261 In this case, the hash is computed on an archive containing @var{file},
6262 including its children if it is a directory. Some of the metadata of
6263 @var{file} is part of the archive; for instance, when @var{file} is a
6264 regular file, the hash is different depending on whether @var{file} is
6265 executable or not. Metadata such as time stamps has no impact on the
6266 hash (@pxref{Invoking guix archive}).
6267 @c FIXME: Replace xref above with xref to an ``Archive'' section when
6272 When combined with @option{--recursive}, exclude version control system
6273 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
6276 As an example, here is how you would compute the hash of a Git checkout,
6277 which is useful when using the @code{git-fetch} method (@pxref{origin
6281 $ git clone http://example.org/foo.git
6287 @node Invoking guix import
6288 @section Invoking @command{guix import}
6290 @cindex importing packages
6291 @cindex package import
6292 @cindex package conversion
6293 @cindex Invoking @command{guix import}
6294 The @command{guix import} command is useful for people who would like to
6295 add a package to the distribution with as little work as
6296 possible---a legitimate demand. The command knows of a few
6297 repositories from which it can ``import'' package metadata. The result
6298 is a package definition, or a template thereof, in the format we know
6299 (@pxref{Defining Packages}).
6301 The general syntax is:
6304 guix import @var{importer} @var{options}@dots{}
6307 @var{importer} specifies the source from which to import package
6308 metadata, and @var{options} specifies a package identifier and other
6309 options specific to @var{importer}. Currently, the available
6314 Import metadata for the given GNU package. This provides a template
6315 for the latest version of that GNU package, including the hash of its
6316 source tarball, and its canonical synopsis and description.
6318 Additional information such as the package dependencies and its
6319 license needs to be figured out manually.
6321 For example, the following command returns a package definition for
6325 guix import gnu hello
6328 Specific command-line options are:
6331 @item --key-download=@var{policy}
6332 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
6333 keys when verifying the package signature. @xref{Invoking guix
6334 refresh, @code{--key-download}}.
6339 Import metadata from the @uref{https://pypi.python.org/, Python Package
6340 Index}@footnote{This functionality requires Guile-JSON to be installed.
6341 @xref{Requirements}.}. Information is taken from the JSON-formatted
6342 description available at @code{pypi.python.org} and usually includes all
6343 the relevant information, including package dependencies. For maximum
6344 efficiency, it is recommended to install the @command{unzip} utility, so
6345 that the importer can unzip Python wheels and gather data from them.
6347 The command below imports metadata for the @code{itsdangerous} Python
6351 guix import pypi itsdangerous
6356 Import metadata from @uref{https://rubygems.org/,
6357 RubyGems}@footnote{This functionality requires Guile-JSON to be
6358 installed. @xref{Requirements}.}. Information is taken from the
6359 JSON-formatted description available at @code{rubygems.org} and includes
6360 most relevant information, including runtime dependencies. There are
6361 some caveats, however. The metadata doesn't distinguish between
6362 synopses and descriptions, so the same string is used for both fields.
6363 Additionally, the details of non-Ruby dependencies required to build
6364 native extensions is unavailable and left as an exercise to the
6367 The command below imports metadata for the @code{rails} Ruby package:
6370 guix import gem rails
6375 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}@footnote{This
6376 functionality requires Guile-JSON to be installed.
6377 @xref{Requirements}.}.
6378 Information is taken from the JSON-formatted metadata provided through
6379 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
6380 relevant information, such as module dependencies. License information
6381 should be checked closely. If Perl is available in the store, then the
6382 @code{corelist} utility will be used to filter core modules out of the
6383 list of dependencies.
6385 The command command below imports metadata for the @code{Acme::Boolean}
6389 guix import cpan Acme::Boolean
6394 @cindex Bioconductor
6395 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
6396 central repository for the @uref{http://r-project.org, GNU@tie{}R
6397 statistical and graphical environment}.
6399 Information is extracted from the @code{DESCRIPTION} file of the package.
6401 The command command below imports metadata for the @code{Cairo}
6405 guix import cran Cairo
6408 When @code{--recursive} is added, the importer will traverse the
6409 dependency graph of the given upstream package recursively and generate
6410 package expressions for all those packages that are not yet in Guix.
6412 When @code{--archive=bioconductor} is added, metadata is imported from
6413 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
6414 packages for for the analysis and comprehension of high-throughput
6415 genomic data in bioinformatics.
6417 Information is extracted from the @code{DESCRIPTION} file of a package
6418 published on the web interface of the Bioconductor SVN repository.
6420 The command below imports metadata for the @code{GenomicRanges}
6424 guix import cran --archive=bioconductor GenomicRanges
6430 Import metadata from @uref{http://www.ctan.org/, CTAN}, the
6431 comprehensive TeX archive network for TeX packages that are part of the
6432 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
6434 Information about the package is obtained through the XML API provided
6435 by CTAN, while the source code is downloaded from the SVN repository of
6436 the Tex Live project. This is done because the CTAN does not keep
6439 The command command below imports metadata for the @code{fontspec}
6443 guix import texlive fontspec
6446 When @code{--archive=DIRECTORY} is added, the source code is downloaded
6447 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
6448 tree in the TeX Live SVN repository, but from the specified sibling
6449 directory under the same root.
6451 The command below imports metadata for the @code{ifxetex} package from
6452 CTAN while fetching the sources from the directory
6453 @file{texmf/source/generic}:
6456 guix import texlive --archive=generic ifxetex
6460 @cindex JSON, import
6461 Import package metadata from a local JSON file@footnote{This
6462 functionality requires Guile-JSON to be installed.
6463 @xref{Requirements}.}. Consider the following example package
6464 definition in JSON format:
6470 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
6471 "build-system": "gnu",
6472 "home-page": "https://www.gnu.org/software/hello/",
6473 "synopsis": "Hello, GNU world: An example GNU package",
6474 "description": "GNU Hello prints a greeting.",
6475 "license": "GPL-3.0+",
6476 "native-inputs": ["gcc@@6"]
6480 The field names are the same as for the @code{<package>} record
6481 (@xref{Defining Packages}). References to other packages are provided
6482 as JSON lists of quoted package specification strings such as
6483 @code{guile} or @code{guile@@2.0}.
6485 The importer also supports a more explicit source definition using the
6486 common fields for @code{<origin>} records:
6492 "method": "url-fetch",
6493 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
6495 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
6502 The command below reads metadata from the JSON file @code{hello.json}
6503 and outputs a package expression:
6506 guix import json hello.json
6510 Import metadata from a local copy of the source of the
6511 @uref{http://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
6512 relies on the @command{nix-instantiate} command of
6513 @uref{http://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
6514 typically written in a mixture of Nix-language and Bash code. This
6515 command only imports the high-level package structure that is written in
6516 the Nix language. It normally includes all the basic fields of a
6519 When importing a GNU package, the synopsis and descriptions are replaced
6520 by their canonical upstream variant.
6522 Usually, you will first need to do:
6525 export NIX_REMOTE=daemon
6529 so that @command{nix-instantiate} does not try to open the Nix database.
6531 As an example, the command below imports the package definition of
6532 LibreOffice (more precisely, it imports the definition of the package
6533 bound to the @code{libreoffice} top-level attribute):
6536 guix import nix ~/path/to/nixpkgs libreoffice
6541 Import metadata from the Haskell community's central package archive
6542 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
6543 Cabal files and includes all the relevant information, including package
6546 Specific command-line options are:
6551 Read a Cabal file from standard input.
6552 @item --no-test-dependencies
6554 Do not include dependencies required only by the test suites.
6555 @item --cabal-environment=@var{alist}
6556 @itemx -e @var{alist}
6557 @var{alist} is a Scheme alist defining the environment in which the
6558 Cabal conditionals are evaluated. The accepted keys are: @code{os},
6559 @code{arch}, @code{impl} and a string representing the name of a flag.
6560 The value associated with a flag has to be either the symbol
6561 @code{true} or @code{false}. The value associated with other keys
6562 has to conform to the Cabal file format definition. The default value
6563 associated with the keys @code{os}, @code{arch} and @code{impl} is
6564 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
6567 The command below imports metadata for the latest version of the
6568 @code{HTTP} Haskell package without including test dependencies and
6569 specifying the value of the flag @samp{network-uri} as @code{false}:
6572 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
6575 A specific package version may optionally be specified by following the
6576 package name by an at-sign and a version number as in the following example:
6579 guix import hackage mtl@@2.1.3.1
6584 The @code{stackage} importer is a wrapper around the @code{hackage} one.
6585 It takes a package name, looks up the package version included in a
6586 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
6587 release and uses the @code{hackage} importer to retrieve its metadata.
6588 Note that it is up to you to select an LTS release compatible with the
6589 GHC compiler used by Guix.
6591 Specific command-line options are:
6594 @item --no-test-dependencies
6596 Do not include dependencies required only by the test suites.
6597 @item --lts-version=@var{version}
6598 @itemx -r @var{version}
6599 @var{version} is the desired LTS release version. If omitted the latest
6603 The command below imports metadata for the @code{HTTP} Haskell package
6604 included in the LTS Stackage release version 7.18:
6607 guix import stackage --lts-version=7.18 HTTP
6612 Import metadata from an Emacs Lisp Package Archive (ELPA) package
6613 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6615 Specific command-line options are:
6618 @item --archive=@var{repo}
6619 @itemx -a @var{repo}
6620 @var{repo} identifies the archive repository from which to retrieve the
6621 information. Currently the supported repositories and their identifiers
6625 @uref{http://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
6626 identifier. This is the default.
6628 Packages from @code{elpa.gnu.org} are signed with one of the keys
6629 contained in the GnuPG keyring at
6630 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
6631 @code{emacs} package (@pxref{Package Installation, ELPA package
6632 signatures,, emacs, The GNU Emacs Manual}).
6635 @uref{http://stable.melpa.org/packages, MELPA-Stable}, selected by the
6636 @code{melpa-stable} identifier.
6639 @uref{http://melpa.org/packages, MELPA}, selected by the @code{melpa}
6645 Traverse the dependency graph of the given upstream package recursively
6646 and generate package expressions for all those packages that are not yet
6652 Import metadata from the crates.io Rust package repository
6653 @uref{https://crates.io, crates.io}.
6656 The structure of the @command{guix import} code is modular. It would be
6657 useful to have more importers for other package formats, and your help
6658 is welcome here (@pxref{Contributing}).
6660 @node Invoking guix refresh
6661 @section Invoking @command{guix refresh}
6663 @cindex @command {guix refresh}
6664 The primary audience of the @command{guix refresh} command is developers
6665 of the GNU software distribution. By default, it reports any packages
6666 provided by the distribution that are outdated compared to the latest
6667 upstream version, like this:
6671 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
6672 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
6675 Alternately, one can specify packages to consider, in which case a
6676 warning is emitted for packages that lack an updater:
6679 $ guix refresh coreutils guile guile-ssh
6680 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
6681 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
6684 @command{guix refresh} browses the upstream repository of each package and determines
6685 the highest version number of the releases therein. The command
6686 knows how to update specific types of packages: GNU packages, ELPA
6687 packages, etc.---see the documentation for @option{--type} below. There
6688 are many packages, though, for which it lacks a method to determine
6689 whether a new upstream release is available. However, the mechanism is
6690 extensible, so feel free to get in touch with us to add a new method!
6692 Sometimes the upstream name differs from the package name used in Guix,
6693 and @command{guix refresh} needs a little help. Most updaters honor the
6694 @code{upstream-name} property in package definitions, which can be used
6698 (define-public network-manager
6700 (name "network-manager")
6702 (properties '((upstream-name . "NetworkManager")))))
6705 When passed @code{--update}, it modifies distribution source files to
6706 update the version numbers and source tarball hashes of those package
6707 recipes (@pxref{Defining Packages}). This is achieved by downloading
6708 each package's latest source tarball and its associated OpenPGP
6709 signature, authenticating the downloaded tarball against its signature
6710 using @command{gpg}, and finally computing its hash. When the public
6711 key used to sign the tarball is missing from the user's keyring, an
6712 attempt is made to automatically retrieve it from a public key server;
6713 when this is successful, the key is added to the user's keyring; otherwise,
6714 @command{guix refresh} reports an error.
6716 The following options are supported:
6720 @item --expression=@var{expr}
6721 @itemx -e @var{expr}
6722 Consider the package @var{expr} evaluates to.
6724 This is useful to precisely refer to a package, as in this example:
6727 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
6730 This command lists the dependents of the ``final'' libc (essentially all
6735 Update distribution source files (package recipes) in place. This is
6736 usually run from a checkout of the Guix source tree (@pxref{Running
6737 Guix Before It Is Installed}):
6740 $ ./pre-inst-env guix refresh -s non-core -u
6743 @xref{Defining Packages}, for more information on package definitions.
6745 @item --select=[@var{subset}]
6746 @itemx -s @var{subset}
6747 Select all the packages in @var{subset}, one of @code{core} or
6750 The @code{core} subset refers to all the packages at the core of the
6751 distribution---i.e., packages that are used to build ``everything
6752 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
6753 changing one of these packages in the distribution entails a rebuild of
6754 all the others. Thus, such updates are an inconvenience to users in
6755 terms of build time or bandwidth used to achieve the upgrade.
6757 The @code{non-core} subset refers to the remaining packages. It is
6758 typically useful in cases where an update of the core packages would be
6761 @item --manifest=@var{file}
6762 @itemx -m @var{file}
6763 Select all the packages from the manifest in @var{file}. This is useful to
6764 check if any packages of the user manifest can be updated.
6766 @item --type=@var{updater}
6767 @itemx -t @var{updater}
6768 Select only packages handled by @var{updater} (may be a comma-separated
6769 list of updaters). Currently, @var{updater} may be one of:
6773 the updater for GNU packages;
6775 the updater for GNOME packages;
6777 the updater for KDE packages;
6779 the updater for X.org packages;
6781 the updater for packages hosted on kernel.org;
6783 the updater for @uref{http://elpa.gnu.org/, ELPA} packages;
6785 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
6787 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
6789 the updater for @uref{http://www.cpan.org/, CPAN} packages;
6791 the updater for @uref{https://pypi.python.org, PyPI} packages.
6793 the updater for @uref{https://rubygems.org, RubyGems} packages.
6795 the updater for @uref{https://github.com, GitHub} packages.
6797 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
6799 the updater for @uref{https://www.stackage.org, Stackage} packages.
6801 the updater for @uref{https://crates.io, Crates} packages.
6804 For instance, the following command only checks for updates of Emacs
6805 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
6808 $ guix refresh --type=elpa,cran
6809 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
6810 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
6815 In addition, @command{guix refresh} can be passed one or more package
6816 names, as in this example:
6819 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
6823 The command above specifically updates the @code{emacs} and
6824 @code{idutils} packages. The @code{--select} option would have no
6825 effect in this case.
6827 When considering whether to upgrade a package, it is sometimes
6828 convenient to know which packages would be affected by the upgrade and
6829 should be checked for compatibility. For this the following option may
6830 be used when passing @command{guix refresh} one or more package names:
6834 @item --list-updaters
6836 List available updaters and exit (see @option{--type} above.)
6838 For each updater, display the fraction of packages it covers; at the
6839 end, display the fraction of packages covered by all these updaters.
6841 @item --list-dependent
6843 List top-level dependent packages that would need to be rebuilt as a
6844 result of upgrading one or more packages.
6846 @xref{Invoking guix graph, the @code{reverse-package} type of
6847 @command{guix graph}}, for information on how to visualize the list of
6848 dependents of a package.
6852 Be aware that the @code{--list-dependent} option only
6853 @emph{approximates} the rebuilds that would be required as a result of
6854 an upgrade. More rebuilds might be required under some circumstances.
6857 $ guix refresh --list-dependent flex
6858 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
6859 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
6862 The command above lists a set of packages that could be built to check
6863 for compatibility with an upgraded @code{flex} package.
6865 The following options can be used to customize GnuPG operation:
6869 @item --gpg=@var{command}
6870 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
6871 for in @code{$PATH}.
6873 @item --key-download=@var{policy}
6874 Handle missing OpenPGP keys according to @var{policy}, which may be one
6879 Always download missing OpenPGP keys from the key server, and add them
6880 to the user's GnuPG keyring.
6883 Never try to download missing OpenPGP keys. Instead just bail out.
6886 When a package signed with an unknown OpenPGP key is encountered, ask
6887 the user whether to download it or not. This is the default behavior.
6890 @item --key-server=@var{host}
6891 Use @var{host} as the OpenPGP key server when importing a public key.
6895 The @code{github} updater uses the
6896 @uref{https://developer.github.com/v3/, GitHub API} to query for new
6897 releases. When used repeatedly e.g. when refreshing all packages,
6898 GitHub will eventually refuse to answer any further API requests. By
6899 default 60 API requests per hour are allowed, and a full refresh on all
6900 GitHub packages in Guix requires more than this. Authentication with
6901 GitHub through the use of an API token alleviates these limits. To use
6902 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
6903 token procured from @uref{https://github.com/settings/tokens} or
6907 @node Invoking guix lint
6908 @section Invoking @command{guix lint}
6910 @cindex @command{guix lint}
6911 @cindex package, checking for errors
6912 The @command{guix lint} command is meant to help package developers avoid
6913 common errors and use a consistent style. It runs a number of checks on
6914 a given set of packages in order to find common mistakes in their
6915 definitions. Available @dfn{checkers} include (see
6916 @code{--list-checkers} for a complete list):
6921 Validate certain typographical and stylistic rules about package
6922 descriptions and synopses.
6924 @item inputs-should-be-native
6925 Identify inputs that should most likely be native inputs.
6930 @itemx source-file-name
6931 Probe @code{home-page} and @code{source} URLs and report those that are
6932 invalid. Suggest a @code{mirror://} URL when applicable. Check that
6933 the source file name is meaningful, e.g. is not
6934 just a version number or ``git-checkout'', without a declared
6935 @code{file-name} (@pxref{origin Reference}).
6938 @cindex security vulnerabilities
6939 @cindex CVE, Common Vulnerabilities and Exposures
6940 Report known vulnerabilities found in the Common Vulnerabilities and
6941 Exposures (CVE) databases of the current and past year
6942 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
6945 To view information about a particular vulnerability, visit pages such as:
6949 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
6951 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
6955 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
6956 @code{CVE-2015-7554}.
6958 Package developers can specify in package recipes the
6959 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
6960 name and version of the package when they differ from the name or version
6961 that Guix uses, as in this example:
6967 ;; CPE calls this package "grub2".
6968 (properties '((cpe-name . "grub2")
6969 (cpe-version . "2.3")))
6972 @c See <http://www.openwall.com/lists/oss-security/2017/03/15/3>.
6973 Some entries in the CVE database do not specify which version of a
6974 package they apply to, and would thus ``stick around'' forever. Package
6975 developers who found CVE alerts and verified they can be ignored can
6976 declare them as in this example:
6982 ;; These CVEs no longer apply and can be safely ignored.
6983 (properties `((lint-hidden-cve . ("CVE-2011-0433"
6986 "CVE-2011-5244")))))
6990 Warn about obvious source code formatting issues: trailing white space,
6991 use of tabulations, etc.
6994 The general syntax is:
6997 guix lint @var{options} @var{package}@dots{}
7000 If no package is given on the command line, then all packages are checked.
7001 The @var{options} may be zero or more of the following:
7004 @item --list-checkers
7006 List and describe all the available checkers that will be run on packages
7011 Only enable the checkers specified in a comma-separated list using the
7012 names returned by @code{--list-checkers}.
7016 @node Invoking guix size
7017 @section Invoking @command{guix size}
7020 @cindex package size
7022 @cindex @command{guix size}
7023 The @command{guix size} command helps package developers profile the
7024 disk usage of packages. It is easy to overlook the impact of an
7025 additional dependency added to a package, or the impact of using a
7026 single output for a package that could easily be split (@pxref{Packages
7027 with Multiple Outputs}). Such are the typical issues that
7028 @command{guix size} can highlight.
7030 The command can be passed one or more package specifications
7031 such as @code{gcc@@4.8}
7032 or @code{guile:debug}, or a file name in the store. Consider this
7036 $ guix size coreutils
7037 store item total self
7038 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
7039 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
7040 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
7041 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
7042 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
7043 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
7044 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
7045 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
7050 The store items listed here constitute the @dfn{transitive closure} of
7051 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
7052 would be returned by:
7055 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
7058 Here the output shows three columns next to store items. The first column,
7059 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
7060 the store item---that is, its own size plus the size of all its
7061 dependencies. The next column, labeled ``self'', shows the size of the
7062 item itself. The last column shows the ratio of the size of the item
7063 itself to the space occupied by all the items listed here.
7065 In this example, we see that the closure of Coreutils weighs in at
7066 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
7067 libraries. (That libc and GCC's libraries represent a large fraction of
7068 the closure is not a problem @i{per se} because they are always available
7069 on the system anyway.)
7071 When the package(s) passed to @command{guix size} are available in the
7072 store@footnote{More precisely, @command{guix size} looks for the
7073 @emph{ungrafted} variant of the given package(s), as returned by
7074 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
7075 for information on grafts.}, @command{guix size} queries the daemon to determine its
7076 dependencies, and measures its size in the store, similar to @command{du
7077 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
7080 When the given packages are @emph{not} in the store, @command{guix size}
7081 reports information based on the available substitutes
7082 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
7083 store items that are not even on disk, only available remotely.
7085 You can also specify several package names:
7088 $ guix size coreutils grep sed bash
7089 store item total self
7090 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
7091 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
7092 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
7093 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
7099 In this example we see that the combination of the four packages takes
7100 102.3@tie{}MiB in total, which is much less than the sum of each closure
7101 since they have a lot of dependencies in common.
7103 The available options are:
7107 @item --substitute-urls=@var{urls}
7108 Use substitute information from @var{urls}.
7109 @xref{client-substitute-urls, the same option for @code{guix build}}.
7111 @item --sort=@var{key}
7112 Sort lines according to @var{key}, one of the following options:
7116 the size of each item (the default);
7118 the total size of the item's closure.
7121 @item --map-file=@var{file}
7122 Write a graphical map of disk usage in PNG format to @var{file}.
7124 For the example above, the map looks like this:
7126 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
7127 produced by @command{guix size}}
7129 This option requires that
7130 @uref{http://wingolog.org/software/guile-charting/, Guile-Charting} be
7131 installed and visible in Guile's module search path. When that is not
7132 the case, @command{guix size} fails as it tries to load it.
7134 @item --system=@var{system}
7135 @itemx -s @var{system}
7136 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
7140 @node Invoking guix graph
7141 @section Invoking @command{guix graph}
7144 @cindex @command{guix graph}
7145 @cindex package dependencies
7146 Packages and their dependencies form a @dfn{graph}, specifically a
7147 directed acyclic graph (DAG). It can quickly become difficult to have a
7148 mental model of the package DAG, so the @command{guix graph} command
7149 provides a visual representation of the DAG. By default,
7150 @command{guix graph} emits a DAG representation in the input format of
7151 @uref{http://www.graphviz.org/, Graphviz}, so its output can be passed
7152 directly to the @command{dot} command of Graphviz. It can also emit an
7153 HTML page with embedded JavaScript code to display a ``chord diagram''
7154 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
7155 emit Cypher queries to construct a graph in a graph database supporting
7156 the @uref{http://www.opencypher.org/, openCypher} query language.
7157 The general syntax is:
7160 guix graph @var{options} @var{package}@dots{}
7163 For example, the following command generates a PDF file representing the
7164 package DAG for the GNU@tie{}Core Utilities, showing its build-time
7168 guix graph coreutils | dot -Tpdf > dag.pdf
7171 The output looks like this:
7173 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
7175 Nice little graph, no?
7177 But there is more than one graph! The one above is concise: it is the
7178 graph of package objects, omitting implicit inputs such as GCC, libc,
7179 grep, etc. It is often useful to have such a concise graph, but
7180 sometimes one may want to see more details. @command{guix graph} supports
7181 several types of graphs, allowing you to choose the level of detail:
7185 This is the default type used in the example above. It shows the DAG of
7186 package objects, excluding implicit dependencies. It is concise, but
7187 filters out many details.
7189 @item reverse-package
7190 This shows the @emph{reverse} DAG of packages. For example:
7193 guix graph --type=reverse-package ocaml
7196 ... yields the graph of packages that depend on OCaml.
7198 Note that for core packages this can yield huge graphs. If all you want
7199 is to know the number of packages that depend on a given package, use
7200 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
7201 @option{--list-dependent}}).
7204 This is the package DAG, @emph{including} implicit inputs.
7206 For instance, the following command:
7209 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
7212 ... yields this bigger graph:
7214 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
7216 At the bottom of the graph, we see all the implicit inputs of
7217 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
7219 Now, note that the dependencies of these implicit inputs---that is, the
7220 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
7221 here, for conciseness.
7224 Similar to @code{bag-emerged}, but this time including all the bootstrap
7227 @item bag-with-origins
7228 Similar to @code{bag}, but also showing origins and their dependencies.
7231 This is the most detailed representation: It shows the DAG of
7232 derivations (@pxref{Derivations}) and plain store items. Compared to
7233 the above representation, many additional nodes are visible, including
7234 build scripts, patches, Guile modules, etc.
7236 For this type of graph, it is also possible to pass a @file{.drv} file
7237 name instead of a package name, as in:
7240 guix graph -t derivation `guix system build -d my-config.scm`
7244 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
7245 For example, the following command shows the graph for the package
7246 module that defines the @code{guile} package:
7249 guix graph -t module guile | dot -Tpdf > module-graph.pdf
7253 All the types above correspond to @emph{build-time dependencies}. The
7254 following graph type represents the @emph{run-time dependencies}:
7258 This is the graph of @dfn{references} of a package output, as returned
7259 by @command{guix gc --references} (@pxref{Invoking guix gc}).
7261 If the given package output is not available in the store, @command{guix
7262 graph} attempts to obtain dependency information from substitutes.
7264 Here you can also pass a store file name instead of a package name. For
7265 example, the command below produces the reference graph of your profile
7266 (which can be big!):
7269 guix graph -t references `readlink -f ~/.guix-profile`
7273 This is the graph of the @dfn{referrers} of a store item, as returned by
7274 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
7276 This relies exclusively on local information from your store. For
7277 instance, let us suppose that the current Inkscape is available in 10
7278 profiles on your machine; @command{guix graph -t referrers inkscape}
7279 will show a graph rooted at Inkscape and with those 10 profiles linked
7282 It can help determine what is preventing a store item from being garbage
7287 The available options are the following:
7290 @item --type=@var{type}
7291 @itemx -t @var{type}
7292 Produce a graph output of @var{type}, where @var{type} must be one of
7293 the values listed above.
7296 List the supported graph types.
7298 @item --backend=@var{backend}
7299 @itemx -b @var{backend}
7300 Produce a graph using the selected @var{backend}.
7302 @item --list-backends
7303 List the supported graph backends.
7305 Currently, the available backends are Graphviz and d3.js.
7307 @item --expression=@var{expr}
7308 @itemx -e @var{expr}
7309 Consider the package @var{expr} evaluates to.
7311 This is useful to precisely refer to a package, as in this example:
7314 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
7319 @node Invoking guix environment
7320 @section Invoking @command{guix environment}
7322 @cindex reproducible build environments
7323 @cindex development environments
7324 @cindex @command{guix environment}
7325 @cindex environment, package build environment
7326 The purpose of @command{guix environment} is to assist hackers in
7327 creating reproducible development environments without polluting their
7328 package profile. The @command{guix environment} tool takes one or more
7329 packages, builds all of their inputs, and creates a shell
7330 environment to use them.
7332 The general syntax is:
7335 guix environment @var{options} @var{package}@dots{}
7338 The following example spawns a new shell set up for the development of
7342 guix environment guile
7345 If the needed dependencies are not built yet, @command{guix environment}
7346 automatically builds them. The environment of the new shell is an augmented
7347 version of the environment that @command{guix environment} was run in.
7348 It contains the necessary search paths for building the given package
7349 added to the existing environment variables. To create a ``pure''
7350 environment, in which the original environment variables have been unset,
7351 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
7352 environment variables such as @code{PATH} in their @file{~/.bashrc}
7353 file. As a consequence, when @code{guix environment} launches it, Bash
7354 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
7355 environment variables. It is an error to define such environment
7356 variables in @file{.bashrc}; instead, they should be defined in
7357 @file{.bash_profile}, which is sourced only by log-in shells.
7358 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
7359 details on Bash start-up files.}.
7361 @vindex GUIX_ENVIRONMENT
7362 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
7363 variable in the shell it spawns; its value is the file name of the
7364 profile of this environment. This allows users to, say, define a
7365 specific prompt for development environments in their @file{.bashrc}
7366 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
7369 if [ -n "$GUIX_ENVIRONMENT" ]
7371 export PS1="\u@@\h \w [dev]\$ "
7376 ... or to browse the profile:
7379 $ ls "$GUIX_ENVIRONMENT/bin"
7382 Additionally, more than one package may be specified, in which case the
7383 union of the inputs for the given packages are used. For example, the
7384 command below spawns a shell where all of the dependencies of both Guile
7385 and Emacs are available:
7388 guix environment guile emacs
7391 Sometimes an interactive shell session is not desired. An arbitrary
7392 command may be invoked by placing the @code{--} token to separate the
7393 command from the rest of the arguments:
7396 guix environment guile -- make -j4
7399 In other situations, it is more convenient to specify the list of
7400 packages needed in the environment. For example, the following command
7401 runs @command{python} from an environment containing Python@tie{}2.7 and
7405 guix environment --ad-hoc python2-numpy python-2.7 -- python
7408 Furthermore, one might want the dependencies of a package and also some
7409 additional packages that are not build-time or runtime dependencies, but
7410 are useful when developing nonetheless. Because of this, the
7411 @code{--ad-hoc} flag is positional. Packages appearing before
7412 @code{--ad-hoc} are interpreted as packages whose dependencies will be
7413 added to the environment. Packages appearing after are interpreted as
7414 packages that will be added to the environment directly. For example,
7415 the following command creates a Guix development environment that
7416 additionally includes Git and strace:
7419 guix environment guix --ad-hoc git strace
7422 Sometimes it is desirable to isolate the environment as much as
7423 possible, for maximal purity and reproducibility. In particular, when
7424 using Guix on a host distro that is not GuixSD, it is desirable to
7425 prevent access to @file{/usr/bin} and other system-wide resources from
7426 the development environment. For example, the following command spawns
7427 a Guile REPL in a ``container'' where only the store and the current
7428 working directory are mounted:
7431 guix environment --ad-hoc --container guile -- guile
7435 The @code{--container} option requires Linux-libre 3.19 or newer.
7438 The available options are summarized below.
7441 @item --root=@var{file}
7442 @itemx -r @var{file}
7443 @cindex persistent environment
7444 @cindex garbage collector root, for environments
7445 Make @var{file} a symlink to the profile for this environment, and
7446 register it as a garbage collector root.
7448 This is useful if you want to protect your environment from garbage
7449 collection, to make it ``persistent''.
7451 When this option is omitted, the environment is protected from garbage
7452 collection only for the duration of the @command{guix environment}
7453 session. This means that next time you recreate the same environment,
7454 you could have to rebuild or re-download packages. @xref{Invoking guix
7455 gc}, for more on GC roots.
7457 @item --expression=@var{expr}
7458 @itemx -e @var{expr}
7459 Create an environment for the package or list of packages that
7460 @var{expr} evaluates to.
7462 For example, running:
7465 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
7468 starts a shell with the environment for this specific variant of the
7474 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
7477 starts a shell with all the GuixSD base packages available.
7479 The above commands only use the default output of the given packages.
7480 To select other outputs, two element tuples can be specified:
7483 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
7486 @item --load=@var{file}
7487 @itemx -l @var{file}
7488 Create an environment for the package or list of packages that the code
7489 within @var{file} evaluates to.
7491 As an example, @var{file} might contain a definition like this
7492 (@pxref{Defining Packages}):
7495 @verbatiminclude environment-gdb.scm
7498 @item --manifest=@var{file}
7499 @itemx -m @var{file}
7500 Create an environment for the packages contained in the manifest object
7501 returned by the Scheme code in @var{file}.
7503 This is similar to the same-named option in @command{guix package}
7504 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
7508 Include all specified packages in the resulting environment, as if an
7509 @i{ad hoc} package were defined with them as inputs. This option is
7510 useful for quickly creating an environment without having to write a
7511 package expression to contain the desired inputs.
7513 For instance, the command:
7516 guix environment --ad-hoc guile guile-sdl -- guile
7519 runs @command{guile} in an environment where Guile and Guile-SDL are
7522 Note that this example implicitly asks for the default output of
7523 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
7524 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
7525 of @code{glib} (@pxref{Packages with Multiple Outputs}).
7527 This option may be composed with the default behavior of @command{guix
7528 environment}. Packages appearing before @code{--ad-hoc} are interpreted
7529 as packages whose dependencies will be added to the environment, the
7530 default behavior. Packages appearing after are interpreted as packages
7531 that will be added to the environment directly.
7534 Unset existing environment variables when building the new environment.
7535 This has the effect of creating an environment in which search paths
7536 only contain package inputs.
7538 @item --search-paths
7539 Display the environment variable definitions that make up the
7542 @item --system=@var{system}
7543 @itemx -s @var{system}
7544 Attempt to build for @var{system}---e.g., @code{i686-linux}.
7549 Run @var{command} within an isolated container. The current working
7550 directory outside the container is mapped inside the container.
7551 Additionally, unless overridden with @code{--user}, a dummy home
7552 directory is created that matches the current user's home directory, and
7553 @file{/etc/passwd} is configured accordingly. The spawned process runs
7554 as the current user outside the container, but has root privileges in
7555 the context of the container.
7559 For containers, share the network namespace with the host system.
7560 Containers created without this flag only have access to the loopback
7563 @item --link-profile
7565 For containers, link the environment profile to
7566 @file{~/.guix-profile} within the container. This is equivalent to
7567 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
7568 within the container. Linking will fail and abort the environment if
7569 the directory already exists, which will certainly be the case if
7570 @command{guix environment} was invoked in the user's home directory.
7572 Certain packages are configured to look in
7573 @code{~/.guix-profile} for configuration files and data;@footnote{For
7574 example, the @code{fontconfig} package inspects
7575 @file{~/.guix-profile/share/fonts} for additional fonts.}
7576 @code{--link-profile} allows these programs to behave as expected within
7579 @item --user=@var{user}
7580 @itemx -u @var{user}
7581 For containers, use the username @var{user} in place of the current
7582 user. The generated @file{/etc/passwd} entry within the container will
7583 contain the name @var{user}; the home directory will be
7584 @file{/home/USER}; and no user GECOS data will be copied. @var{user}
7585 need not exist on the system.
7587 Additionally, any shared or exposed path (see @code{--share} and
7588 @code{--expose} respectively) whose target is within the current user's
7589 home directory will be remapped relative to @file{/home/USER}; this
7590 includes the automatic mapping of the current working directory.
7593 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
7595 guix environment --container --user=foo \
7596 --expose=$HOME/test \
7597 --expose=/tmp/target=$HOME/target
7600 While this will limit the leaking of user identity through home paths
7601 and each of the user fields, this is only one useful component of a
7602 broader privacy/anonymity solution---not one in and of itself.
7604 @item --expose=@var{source}[=@var{target}]
7605 For containers, expose the file system @var{source} from the host system
7606 as the read-only file system @var{target} within the container. If
7607 @var{target} is not specified, @var{source} is used as the target mount
7608 point in the container.
7610 The example below spawns a Guile REPL in a container in which the user's
7611 home directory is accessible read-only via the @file{/exchange}
7615 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
7618 @item --share=@var{source}[=@var{target}]
7619 For containers, share the file system @var{source} from the host system
7620 as the writable file system @var{target} within the container. If
7621 @var{target} is not specified, @var{source} is used as the target mount
7622 point in the container.
7624 The example below spawns a Guile REPL in a container in which the user's
7625 home directory is accessible for both reading and writing via the
7626 @file{/exchange} directory:
7629 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
7633 @command{guix environment}
7634 also supports all of the common build options that @command{guix
7635 build} supports (@pxref{Common Build Options}).
7638 @node Invoking guix publish
7639 @section Invoking @command{guix publish}
7641 @cindex @command{guix publish}
7642 The purpose of @command{guix publish} is to enable users to easily share
7643 their store with others, who can then use it as a substitute server
7644 (@pxref{Substitutes}).
7646 When @command{guix publish} runs, it spawns an HTTP server which allows
7647 anyone with network access to obtain substitutes from it. This means
7648 that any machine running Guix can also act as if it were a build farm,
7649 since the HTTP interface is compatible with Hydra, the software behind
7650 the @code{hydra.gnu.org} build farm.
7652 For security, each substitute is signed, allowing recipients to check
7653 their authenticity and integrity (@pxref{Substitutes}). Because
7654 @command{guix publish} uses the signing key of the system, which is only
7655 readable by the system administrator, it must be started as root; the
7656 @code{--user} option makes it drop root privileges early on.
7658 The signing key pair must be generated before @command{guix publish} is
7659 launched, using @command{guix archive --generate-key} (@pxref{Invoking
7662 The general syntax is:
7665 guix publish @var{options}@dots{}
7668 Running @command{guix publish} without any additional arguments will
7669 spawn an HTTP server on port 8080:
7675 Once a publishing server has been authorized (@pxref{Invoking guix
7676 archive}), the daemon may download substitutes from it:
7679 guix-daemon --substitute-urls=http://example.org:8080
7682 By default, @command{guix publish} compresses archives on the fly as it
7683 serves them. This ``on-the-fly'' mode is convenient in that it requires
7684 no setup and is immediately available. However, when serving lots of
7685 clients, we recommend using the @option{--cache} option, which enables
7686 caching of the archives before they are sent to clients---see below for
7687 details. The @command{guix weather} command provides a handy way to
7688 check what a server provides (@pxref{Invoking guix weather}).
7690 As a bonus, @command{guix publish} also serves as a content-addressed
7691 mirror for source files referenced in @code{origin} records
7692 (@pxref{origin Reference}). For instance, assuming @command{guix
7693 publish} is running on @code{example.org}, the following URL returns the
7694 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
7695 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
7698 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
7701 Obviously, these URLs only work for files that are in the store; in
7702 other cases, they return 404 (``Not Found'').
7704 @cindex build logs, publication
7705 Build logs are available from @code{/log} URLs like:
7708 http://example.org/log/gwspk@dots{}-guile-2.2.3
7712 When @command{guix-daemon} is configured to save compressed build logs,
7713 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
7714 URLs return the compressed log as-is, with an appropriate
7715 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
7716 running @command{guix-daemon} with @code{--log-compression=gzip} since
7717 Web browsers can automatically decompress it, which is not the case with
7720 The following options are available:
7723 @item --port=@var{port}
7724 @itemx -p @var{port}
7725 Listen for HTTP requests on @var{port}.
7727 @item --listen=@var{host}
7728 Listen on the network interface for @var{host}. The default is to
7729 accept connections from any interface.
7731 @item --user=@var{user}
7732 @itemx -u @var{user}
7733 Change privileges to @var{user} as soon as possible---i.e., once the
7734 server socket is open and the signing key has been read.
7736 @item --compression[=@var{level}]
7737 @itemx -C [@var{level}]
7738 Compress data using the given @var{level}. When @var{level} is zero,
7739 disable compression. The range 1 to 9 corresponds to different gzip
7740 compression levels: 1 is the fastest, and 9 is the best (CPU-intensive).
7743 Unless @option{--cache} is used, compression occurs on the fly and
7744 the compressed streams are not
7745 cached. Thus, to reduce load on the machine that runs @command{guix
7746 publish}, it may be a good idea to choose a low compression level, to
7747 run @command{guix publish} behind a caching proxy, or to use
7748 @option{--cache}. Using @option{--cache} has the advantage that it
7749 allows @command{guix publish} to add @code{Content-Length} HTTP header
7752 @item --cache=@var{directory}
7753 @itemx -c @var{directory}
7754 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
7755 and only serve archives that are in cache.
7757 When this option is omitted, archives and meta-data are created
7758 on-the-fly. This can reduce the available bandwidth, especially when
7759 compression is enabled, since this may become CPU-bound. Another
7760 drawback of the default mode is that the length of archives is not known
7761 in advance, so @command{guix publish} does not add a
7762 @code{Content-Length} HTTP header to its responses, which in turn
7763 prevents clients from knowing the amount of data being downloaded.
7765 Conversely, when @option{--cache} is used, the first request for a store
7766 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
7767 background process to @dfn{bake} the archive---computing its
7768 @code{.narinfo} and compressing the archive, if needed. Once the
7769 archive is cached in @var{directory}, subsequent requests succeed and
7770 are served directly from the cache, which guarantees that clients get
7771 the best possible bandwidth.
7773 The ``baking'' process is performed by worker threads. By default, one
7774 thread per CPU core is created, but this can be customized. See
7775 @option{--workers} below.
7777 When @option{--ttl} is used, cached entries are automatically deleted
7778 when they have expired.
7780 @item --workers=@var{N}
7781 When @option{--cache} is used, request the allocation of @var{N} worker
7782 threads to ``bake'' archives.
7784 @item --ttl=@var{ttl}
7785 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
7786 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
7787 days, @code{1m} means 1 month, and so on.
7789 This allows the user's Guix to keep substitute information in cache for
7790 @var{ttl}. However, note that @code{guix publish} does not itself
7791 guarantee that the store items it provides will indeed remain available
7792 for as long as @var{ttl}.
7794 Additionally, when @option{--cache} is used, cached entries that have
7795 not been accessed for @var{ttl} and that no longer have a corresponding
7796 item in the store, may be deleted.
7798 @item --nar-path=@var{path}
7799 Use @var{path} as the prefix for the URLs of ``nar'' files
7800 (@pxref{Invoking guix archive, normalized archives}).
7802 By default, nars are served at a URL such as
7803 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
7804 change the @code{/nar} part to @var{path}.
7806 @item --public-key=@var{file}
7807 @itemx --private-key=@var{file}
7808 Use the specific @var{file}s as the public/private key pair used to sign
7809 the store items being published.
7811 The files must correspond to the same key pair (the private key is used
7812 for signing and the public key is merely advertised in the signature
7813 metadata). They must contain keys in the canonical s-expression format
7814 as produced by @command{guix archive --generate-key} (@pxref{Invoking
7815 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
7816 @file{/etc/guix/signing-key.sec} are used.
7818 @item --repl[=@var{port}]
7819 @itemx -r [@var{port}]
7820 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
7821 Reference Manual}) on @var{port} (37146 by default). This is used
7822 primarily for debugging a running @command{guix publish} server.
7825 Enabling @command{guix publish} on a GuixSD system is a one-liner: just
7826 instantiate a @code{guix-publish-service-type} service in the @code{services} field
7827 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
7828 @code{guix-publish-service-type}}).
7830 If you are instead running Guix on a ``foreign distro'', follow these
7835 If your host distro uses the systemd init system:
7838 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
7839 /etc/systemd/system/
7840 # systemctl start guix-publish && systemctl enable guix-publish
7844 If your host distro uses the Upstart init system:
7847 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
7848 # start guix-publish
7852 Otherwise, proceed similarly with your distro's init system.
7855 @node Invoking guix challenge
7856 @section Invoking @command{guix challenge}
7858 @cindex reproducible builds
7859 @cindex verifiable builds
7860 @cindex @command{guix challenge}
7862 Do the binaries provided by this server really correspond to the source
7863 code it claims to build? Is a package build process deterministic?
7864 These are the questions the @command{guix challenge} command attempts to
7867 The former is obviously an important question: Before using a substitute
7868 server (@pxref{Substitutes}), one had better @emph{verify} that it
7869 provides the right binaries, and thus @emph{challenge} it. The latter
7870 is what enables the former: If package builds are deterministic, then
7871 independent builds of the package should yield the exact same result,
7872 bit for bit; if a server provides a binary different from the one
7873 obtained locally, it may be either corrupt or malicious.
7875 We know that the hash that shows up in @file{/gnu/store} file names is
7876 the hash of all the inputs of the process that built the file or
7877 directory---compilers, libraries, build scripts,
7878 etc. (@pxref{Introduction}). Assuming deterministic build processes,
7879 one store file name should map to exactly one build output.
7880 @command{guix challenge} checks whether there is, indeed, a single
7881 mapping by comparing the build outputs of several independent builds of
7882 any given store item.
7884 The command output looks like this:
7887 $ guix challenge --substitute-urls="https://hydra.gnu.org https://guix.example.org"
7888 updating list of substitutes from 'https://hydra.gnu.org'... 100.0%
7889 updating list of substitutes from 'https://guix.example.org'... 100.0%
7890 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
7891 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
7892 https://hydra.gnu.org/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
7893 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
7894 /gnu/store/@dots{}-git-2.5.0 contents differ:
7895 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
7896 https://hydra.gnu.org/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
7897 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
7898 /gnu/store/@dots{}-pius-2.1.1 contents differ:
7899 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
7900 https://hydra.gnu.org/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
7901 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
7905 6,406 store items were analyzed:
7906 - 4,749 (74.1%) were identical
7907 - 525 (8.2%) differed
7908 - 1,132 (17.7%) were inconclusive
7912 In this example, @command{guix challenge} first scans the store to
7913 determine the set of locally-built derivations---as opposed to store
7914 items that were downloaded from a substitute server---and then queries
7915 all the substitute servers. It then reports those store items for which
7916 the servers obtained a result different from the local build.
7918 @cindex non-determinism, in package builds
7919 As an example, @code{guix.example.org} always gets a different answer.
7920 Conversely, @code{hydra.gnu.org} agrees with local builds, except in the
7921 case of Git. This might indicate that the build process of Git is
7922 non-deterministic, meaning that its output varies as a function of
7923 various things that Guix does not fully control, in spite of building
7924 packages in isolated environments (@pxref{Features}). Most common
7925 sources of non-determinism include the addition of timestamps in build
7926 results, the inclusion of random numbers, and directory listings sorted
7927 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
7930 To find out what is wrong with this Git binary, we can do something along
7931 these lines (@pxref{Invoking guix archive}):
7934 $ wget -q -O - https://hydra.gnu.org/nar/@dots{}-git-2.5.0 \
7935 | guix archive -x /tmp/git
7936 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
7939 This command shows the difference between the files resulting from the
7940 local build, and the files resulting from the build on
7941 @code{hydra.gnu.org} (@pxref{Overview, Comparing and Merging Files,,
7942 diffutils, Comparing and Merging Files}). The @command{diff} command
7943 works great for text files. When binary files differ, a better option
7944 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
7945 visualize differences for all kinds of files.
7947 Once you have done that work, you can tell whether the differences are due
7948 to a non-deterministic build process or to a malicious server. We try
7949 hard to remove sources of non-determinism in packages to make it easier
7950 to verify substitutes, but of course, this is a process that
7951 involves not just Guix, but a large part of the free software community.
7952 In the meantime, @command{guix challenge} is one tool to help address
7955 If you are writing packages for Guix, you are encouraged to check
7956 whether @code{hydra.gnu.org} and other substitute servers obtain the
7957 same build result as you did with:
7960 $ guix challenge @var{package}
7964 where @var{package} is a package specification such as
7965 @code{guile@@2.0} or @code{glibc:debug}.
7967 The general syntax is:
7970 guix challenge @var{options} [@var{packages}@dots{}]
7973 When a difference is found between the hash of a locally-built item and
7974 that of a server-provided substitute, or among substitutes provided by
7975 different servers, the command displays it as in the example above and
7976 its exit code is 2 (other non-zero exit codes denote other kinds of
7979 The one option that matters is:
7983 @item --substitute-urls=@var{urls}
7984 Consider @var{urls} the whitespace-separated list of substitute source
7989 Show details about matches (identical contents) in addition to
7990 information about mismatches.
7994 @node Invoking guix copy
7995 @section Invoking @command{guix copy}
7997 @cindex copy, of store items, over SSH
7998 @cindex SSH, copy of store items
7999 @cindex sharing store items across machines
8000 @cindex transferring store items across machines
8001 The @command{guix copy} command copies items from the store of one
8002 machine to that of another machine over a secure shell (SSH)
8003 connection@footnote{This command is available only when Guile-SSH was
8004 found. @xref{Requirements}, for details.}. For example, the following
8005 command copies the @code{coreutils} package, the user's profile, and all
8006 their dependencies over to @var{host}, logged in as @var{user}:
8009 guix copy --to=@var{user}@@@var{host} \
8010 coreutils `readlink -f ~/.guix-profile`
8013 If some of the items to be copied are already present on @var{host},
8014 they are not actually sent.
8016 The command below retrieves @code{libreoffice} and @code{gimp} from
8017 @var{host}, assuming they are available there:
8020 guix copy --from=@var{host} libreoffice gimp
8023 The SSH connection is established using the Guile-SSH client, which is
8024 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
8025 @file{~/.ssh/config}, and uses the SSH agent for authentication.
8027 The key used to sign items that are sent must be accepted by the remote
8028 machine. Likewise, the key used by the remote machine to sign items you
8029 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
8030 own daemon. @xref{Invoking guix archive}, for more information about
8031 store item authentication.
8033 The general syntax is:
8036 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
8039 You must always specify one of the following options:
8042 @item --to=@var{spec}
8043 @itemx --from=@var{spec}
8044 Specify the host to send to or receive from. @var{spec} must be an SSH
8045 spec such as @code{example.org}, @code{charlie@@example.org}, or
8046 @code{charlie@@example.org:2222}.
8049 The @var{items} can be either package names, such as @code{gimp}, or
8050 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
8052 When specifying the name of a package to send, it is first built if
8053 needed, unless @option{--dry-run} was specified. Common build options
8054 are supported (@pxref{Common Build Options}).
8057 @node Invoking guix container
8058 @section Invoking @command{guix container}
8060 @cindex @command{guix container}
8062 As of version @value{VERSION}, this tool is experimental. The interface
8063 is subject to radical change in the future.
8066 The purpose of @command{guix container} is to manipulate processes
8067 running within an isolated environment, commonly known as a
8068 ``container'', typically created by the @command{guix environment}
8069 (@pxref{Invoking guix environment}) and @command{guix system container}
8070 (@pxref{Invoking guix system}) commands.
8072 The general syntax is:
8075 guix container @var{action} @var{options}@dots{}
8078 @var{action} specifies the operation to perform with a container, and
8079 @var{options} specifies the context-specific arguments for the action.
8081 The following actions are available:
8085 Execute a command within the context of a running container.
8090 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
8093 @var{pid} specifies the process ID of the running container.
8094 @var{program} specifies an executable file name within the root file
8095 system of the container. @var{arguments} are the additional options that
8096 will be passed to @var{program}.
8098 The following command launches an interactive login shell inside a
8099 GuixSD container, started by @command{guix system container}, and whose
8103 guix container exec 9001 /run/current-system/profile/bin/bash --login
8106 Note that the @var{pid} cannot be the parent process of a container. It
8107 must be PID 1 of the container or one of its child processes.
8111 @node Invoking guix weather
8112 @section Invoking @command{guix weather}
8114 Occasionally you're grumpy because substitutes are lacking and you end
8115 up building packages by yourself (@pxref{Substitutes}). The
8116 @command{guix weather} command reports on substitute availability on the
8117 specified servers so you can have an idea of whether you'll be grumpy
8118 today. It can sometimes be useful info as a user, but it is primarily
8119 useful to people running @command{guix publish} (@pxref{Invoking guix
8122 @cindex statistics, for substitutes
8123 @cindex availability of substitutes
8124 @cindex substitute availability
8125 @cindex weather, substitute availability
8126 Here's a sample run:
8129 $ guix weather --substitute-urls=https://guix.example.org
8130 computing 5,872 package derivations for x86_64-linux...
8131 looking for 6,128 store items on https://guix.example.org..
8132 updating list of substitutes from 'https://guix.example.org'... 100.0%
8133 https://guix.example.org
8134 43.4% substitutes available (2,658 out of 6,128)
8135 7,032.5 MiB of nars (compressed)
8136 19,824.2 MiB on disk (uncompressed)
8137 0.030 seconds per request (182.9 seconds in total)
8138 33.5 requests per second
8140 9.8% (342 out of 3,470) of the missing items are queued
8142 x86_64-linux: 518 (59.7%)
8143 i686-linux: 221 (25.5%)
8144 aarch64-linux: 128 (14.8%)
8145 build rate: 23.41 builds per hour
8146 x86_64-linux: 11.16 builds per hour
8147 i686-linux: 6.03 builds per hour
8148 aarch64-linux: 6.41 builds per hour
8151 @cindex continuous integration, statistics
8152 As you can see, it reports the fraction of all the packages for which
8153 substitutes are available on the server---regardless of whether
8154 substitutes are enabled, and regardless of whether this server's signing
8155 key is authorized. It also reports the size of the compressed archives
8156 (``nars'') provided by the server, the size the corresponding store
8157 items occupy in the store (assuming deduplication is turned off), and
8158 the server's throughput. The second part gives continuous integration
8159 (CI) statistics, if the server supports it.
8161 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
8162 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
8163 challenge}, it ignores signatures on those substitutes, which is
8164 innocuous since the command only gathers statistics and cannot install
8167 Among other things, it is possible to query specific system types and
8168 specific package sets. The available options are listed below.
8171 @item --substitute-urls=@var{urls}
8172 @var{urls} is the space-separated list of substitute server URLs to
8173 query. When this option is omitted, the default set of substitute
8176 @item --system=@var{system}
8177 @itemx -s @var{system}
8178 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
8179 option can be repeated, in which case @command{guix weather} will query
8180 substitutes for several system types.
8182 @item --manifest=@var{file}
8183 Instead of querying substitutes for all the packages, only ask for those
8184 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
8185 with the @code{-m} option of @command{guix package} (@pxref{Invoking
8190 @c *********************************************************************
8191 @node GNU Distribution
8192 @chapter GNU Distribution
8194 @cindex Guix System Distribution
8196 Guix comes with a distribution of the GNU system consisting entirely of
8197 free software@footnote{The term ``free'' here refers to the
8198 @url{http://www.gnu.org/philosophy/free-sw.html,freedom provided to
8199 users of that software}.}. The
8200 distribution can be installed on its own (@pxref{System Installation}),
8201 but it is also possible to install Guix as a package manager on top of
8202 an installed GNU/Linux system (@pxref{Installation}). To distinguish
8203 between the two, we refer to the standalone distribution as the Guix
8204 System Distribution, or GuixSD.
8206 The distribution provides core GNU packages such as GNU libc, GCC, and
8207 Binutils, as well as many GNU and non-GNU applications. The complete
8208 list of available packages can be browsed
8209 @url{http://www.gnu.org/software/guix/packages,on-line} or by
8210 running @command{guix package} (@pxref{Invoking guix package}):
8213 guix package --list-available
8216 Our goal is to provide a practical 100% free software distribution of
8217 Linux-based and other variants of GNU, with a focus on the promotion and
8218 tight integration of GNU components, and an emphasis on programs and
8219 tools that help users exert that freedom.
8221 Packages are currently available on the following platforms:
8226 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
8229 Intel 32-bit architecture (IA32), Linux-Libre kernel;
8232 ARMv7-A architecture with hard float, Thumb-2 and NEON,
8233 using the EABI hard-float application binary interface (ABI),
8234 and Linux-Libre kernel.
8237 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel. This is
8238 currently in an experimental stage, with limited support.
8239 @xref{Contributing}, for how to help!
8241 @item mips64el-linux
8242 little-endian 64-bit MIPS processors, specifically the Loongson series,
8243 n32 ABI, and Linux-Libre kernel.
8247 GuixSD itself is currently only available on @code{i686} and @code{x86_64}.
8250 For information on porting to other architectures or kernels,
8254 * System Installation:: Installing the whole operating system.
8255 * System Configuration:: Configuring the operating system.
8256 * Documentation:: Browsing software user manuals.
8257 * Installing Debugging Files:: Feeding the debugger.
8258 * Security Updates:: Deploying security fixes quickly.
8259 * Package Modules:: Packages from the programmer's viewpoint.
8260 * Packaging Guidelines:: Growing the distribution.
8261 * Bootstrapping:: GNU/Linux built from scratch.
8262 * Porting:: Targeting another platform or kernel.
8265 Building this distribution is a cooperative effort, and you are invited
8266 to join! @xref{Contributing}, for information about how you can help.
8268 @node System Installation
8269 @section System Installation
8271 @cindex installing GuixSD
8272 @cindex Guix System Distribution
8273 This section explains how to install the Guix System Distribution (GuixSD)
8274 on a machine. The Guix package manager can
8275 also be installed on top of a running GNU/Linux system,
8276 @pxref{Installation}.
8280 @c This paragraph is for people reading this from tty2 of the
8281 @c installation image.
8282 You are reading this documentation with an Info reader. For details on
8283 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
8284 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
8285 Info}. Hit @kbd{l} afterwards to come back here.
8287 Alternately, run @command{info info} in another tty to keep the manual
8293 * Limitations:: What you can expect.
8294 * Hardware Considerations:: Supported hardware.
8295 * USB Stick and DVD Installation:: Preparing the installation medium.
8296 * Preparing for Installation:: Networking, partitioning, etc.
8297 * Proceeding with the Installation:: The real thing.
8298 * Installing GuixSD in a VM:: GuixSD playground.
8299 * Building the Installation Image:: How this comes to be.
8303 @subsection Limitations
8305 As of version @value{VERSION}, the Guix System Distribution (GuixSD) is
8306 not production-ready. It may contain bugs and lack important
8307 features. Thus, if you are looking for a stable production system that
8308 respects your freedom as a computer user, a good solution at this point
8309 is to consider @url{http://www.gnu.org/distros/free-distros.html, one of
8310 the more established GNU/Linux distributions}. We hope you can soon switch
8311 to the GuixSD without fear, of course. In the meantime, you can
8312 also keep using your distribution and try out the package manager on top
8313 of it (@pxref{Installation}).
8315 Before you proceed with the installation, be aware of the following
8316 noteworthy limitations applicable to version @value{VERSION}:
8320 The installation process does not include a graphical user interface and
8321 requires familiarity with GNU/Linux (see the following subsections to
8322 get a feel of what that means.)
8325 Support for the Logical Volume Manager (LVM) is missing.
8328 More and more system services are provided (@pxref{Services}), but some
8332 More than 6,500 packages are available, but you might
8333 occasionally find that a useful package is missing.
8336 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
8337 as well as a number of X11 window managers. However, some graphical
8338 applications may be missing, as well as KDE.
8341 You have been warned! But more than a disclaimer, this is an invitation
8342 to report issues (and success stories!), and to join us in improving it.
8343 @xref{Contributing}, for more info.
8346 @node Hardware Considerations
8347 @subsection Hardware Considerations
8349 @cindex hardware support on GuixSD
8350 GNU@tie{}GuixSD focuses on respecting the user's computing freedom. It
8351 builds around the kernel Linux-libre, which means that only hardware for
8352 which free software drivers and firmware exist is supported. Nowadays,
8353 a wide range of off-the-shelf hardware is supported on
8354 GNU/Linux-libre---from keyboards to graphics cards to scanners and
8355 Ethernet controllers. Unfortunately, there are still areas where
8356 hardware vendors deny users control over their own computing, and such
8357 hardware is not supported on GuixSD.
8359 @cindex WiFi, hardware support
8360 One of the main areas where free drivers or firmware are lacking is WiFi
8361 devices. WiFi devices known to work include those using Atheros chips
8362 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
8363 driver, and those using Broadcom/AirForce chips (BCM43xx with
8364 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
8365 Linux-libre driver. Free firmware exists for both and is available
8366 out-of-the-box on GuixSD, as part of @var{%base-firmware}
8367 (@pxref{operating-system Reference, @code{firmware}}).
8369 @cindex RYF, Respects Your Freedom
8370 The @uref{https://www.fsf.org/, Free Software Foundation} runs
8371 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
8372 certification program for hardware products that respect your freedom
8373 and your privacy and ensure that you have control over your device. We
8374 encourage you to check the list of RYF-certified devices.
8376 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
8377 web site. It contains a catalog of hardware devices with information
8378 about their support in GNU/Linux.
8381 @node USB Stick and DVD Installation
8382 @subsection USB Stick and DVD Installation
8384 An ISO-9660 installation image that can be written to a USB stick or
8385 burnt to a DVD can be downloaded from
8386 @indicateurl{ftp://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.iso.xz},
8387 where @var{system} is one of:
8391 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
8394 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
8397 @c start duplication of authentication part from ``Binary Installation''
8398 Make sure to download the associated @file{.sig} file and to verify the
8399 authenticity of the image against it, along these lines:
8402 $ wget ftp://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.iso.xz.sig
8403 $ gpg --verify guixsd-install-@value{VERSION}.@var{system}.iso.xz.sig
8406 If that command fails because you do not have the required public key,
8407 then run this command to import it:
8410 $ gpg --keyserver pgp.mit.edu --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
8414 and rerun the @code{gpg --verify} command.
8417 This image contains the tools necessary for an installation.
8418 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
8420 @unnumberedsubsubsec Copying to a USB Stick
8422 To copy the image to a USB stick, follow these steps:
8426 Decompress the image using the @command{xz} command:
8429 xz -d guixsd-install-@value{VERSION}.@var{system}.iso.xz
8433 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
8434 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
8435 copy the image with:
8438 dd if=guixsd-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX
8442 Access to @file{/dev/sdX} usually requires root privileges.
8445 @unnumberedsubsubsec Burning on a DVD
8447 To copy the image to a DVD, follow these steps:
8451 Decompress the image using the @command{xz} command:
8454 xz -d guixsd-install-@value{VERSION}.@var{system}.iso.xz
8458 Insert a blank DVD into your machine, and determine
8459 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
8460 copy the image with:
8463 growisofs -dvd-compat -Z /dev/srX=guixsd-install-@value{VERSION}.x86_64.iso
8466 Access to @file{/dev/srX} usually requires root privileges.
8469 @unnumberedsubsubsec Booting
8471 Once this is done, you should be able to reboot the system and boot from
8472 the USB stick or DVD. The latter usually requires you to get in the
8473 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
8475 @xref{Installing GuixSD in a VM}, if, instead, you would like to install
8476 GuixSD in a virtual machine (VM).
8479 @node Preparing for Installation
8480 @subsection Preparing for Installation
8482 Once you have successfully booted your computer using the installation medium,
8483 you should end up with a root prompt. Several console TTYs are configured
8484 and can be used to run commands as root. TTY2 shows this documentation,
8485 browsable using the Info reader commands (@pxref{Top,,, info-stnd,
8486 Stand-alone GNU Info}). The installation system runs the GPM mouse
8487 daemon, which allows you to select text with the left mouse button and
8488 to paste it with the middle button.
8491 Installation requires access to the Internet so that any missing
8492 dependencies of your system configuration can be downloaded. See the
8493 ``Networking'' section below.
8496 The installation system includes many common tools needed for this task.
8497 But it is also a full-blown GuixSD system, which means that you can
8498 install additional packages, should you need it, using @command{guix
8499 package} (@pxref{Invoking guix package}).
8501 @subsubsection Keyboard Layout
8503 @cindex keyboard layout
8504 The installation image uses the US qwerty keyboard layout. If you want
8505 to change it, you can use the @command{loadkeys} command. For example,
8506 the following command selects the Dvorak keyboard layout:
8512 See the files under @file{/run/current-system/profile/share/keymaps} for
8513 a list of available keyboard layouts. Run @command{man loadkeys} for
8516 @subsubsection Networking
8518 Run the following command see what your network interfaces are called:
8525 @dots{} or, using the GNU/Linux-specific @command{ip} command:
8531 @c http://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
8532 Wired interfaces have a name starting with @samp{e}; for example, the
8533 interface corresponding to the first on-board Ethernet controller is
8534 called @samp{eno1}. Wireless interfaces have a name starting with
8535 @samp{w}, like @samp{w1p2s0}.
8538 @item Wired connection
8539 To configure a wired network run the following command, substituting
8540 @var{interface} with the name of the wired interface you want to use.
8543 ifconfig @var{interface} up
8546 @item Wireless connection
8549 To configure wireless networking, you can create a configuration file
8550 for the @command{wpa_supplicant} configuration tool (its location is not
8551 important) using one of the available text editors such as
8555 nano wpa_supplicant.conf
8558 As an example, the following stanza can go to this file and will work
8559 for many wireless networks, provided you give the actual SSID and
8560 passphrase for the network you are connecting to:
8564 ssid="@var{my-ssid}"
8566 psk="the network's secret passphrase"
8570 Start the wireless service and run it in the background with the
8571 following command (substitute @var{interface} with the name of the
8572 network interface you want to use):
8575 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
8578 Run @command{man wpa_supplicant} for more information.
8582 At this point, you need to acquire an IP address. On a network where IP
8583 addresses are automatically assigned @i{via} DHCP, you can run:
8586 dhclient -v @var{interface}
8589 Try to ping a server to see if networking is up and running:
8595 Setting up network access is almost always a requirement because the
8596 image does not contain all the software and tools that may be needed.
8598 @cindex installing over SSH
8599 If you want to, you can continue the installation remotely by starting
8603 herd start ssh-daemon
8606 Make sure to either set a password with @command{passwd}, or configure
8607 OpenSSH public key authentication before logging in.
8609 @subsubsection Disk Partitioning
8611 Unless this has already been done, the next step is to partition, and
8612 then format the target partition(s).
8614 The installation image includes several partitioning tools, including
8615 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
8616 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
8617 the partition layout you want:
8623 If your disk uses the GUID Partition Table (GPT) format and you plan to
8624 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
8625 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
8628 @cindex EFI, installation
8629 @cindex UEFI, installation
8630 @cindex ESP, EFI system partition
8631 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
8632 (ESP) is required. This partition should be mounted at @file{/boot/efi} and
8633 must have the @code{esp} flag set. E.g., for @command{parted}:
8636 parted /dev/sda set 1 esp on
8639 Once you are done partitioning the target hard disk drive, you have to
8640 create a file system on the relevant partition(s)@footnote{Currently
8641 GuixSD only supports ext4 and btrfs file systems. In particular, code
8642 that reads file system UUIDs and labels only works for these file system
8643 types.}. For the ESP, if you have one and assuming it is
8644 @file{/dev/sda1}, run:
8647 mkfs.fat -F32 /dev/sda1
8650 Preferably, assign file systems a label so that you can easily and
8651 reliably refer to them in @code{file-system} declarations (@pxref{File
8652 Systems}). This is typically done using the @code{-L} option of
8653 @command{mkfs.ext4} and related commands. So, assuming the target root
8654 partition lives at @file{/dev/sda2}, a file system with the label
8655 @code{my-root} can be created with:
8658 mkfs.ext4 -L my-root /dev/sda2
8661 @cindex encrypted disk
8662 If you are instead planning to encrypt the root partition, you can use
8663 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
8664 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
8665 @code{man cryptsetup}} for more information.) Assuming you want to
8666 store the root partition on @file{/dev/sda2}, the command sequence would
8667 be along these lines:
8670 cryptsetup luksFormat /dev/sda2
8671 cryptsetup open --type luks /dev/sda2 my-partition
8672 mkfs.ext4 -L my-root /dev/mapper/my-partition
8675 Once that is done, mount the target file system under @file{/mnt}
8676 with a command like (again, assuming @code{my-root} is the label of the
8680 mount LABEL=my-root /mnt
8683 Also mount any other file systems you would like to use on the target
8684 system relative to this path. If you have @file{/boot} on a separate
8685 partition for example, mount it at @file{/mnt/boot} now so it is found
8686 by @code{guix system init} afterwards.
8688 Finally, if you plan to use one or more swap partitions (@pxref{Memory
8689 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
8690 sure to initialize them with @command{mkswap}. Assuming you have one
8691 swap partition on @file{/dev/sda3}, you would run:
8698 Alternatively, you may use a swap file. For example, assuming that in
8699 the new system you want to use the file @file{/swapfile} as a swap file,
8700 you would run@footnote{This example will work for many types of file
8701 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
8702 btrfs), the required steps may be different. For details, see the
8703 manual pages for @command{mkswap} and @command{swapon}.}:
8706 # This is 10 GiB of swap space. Adjust "count" to change the size.
8707 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
8708 # For security, make the file readable and writable only by root.
8709 chmod 600 /mnt/swapfile
8710 mkswap /mnt/swapfile
8711 swapon /mnt/swapfile
8714 Note that if you have encrypted the root partition and created a swap
8715 file in its file system as described above, then the encryption also
8716 protects the swap file, just like any other file in that file system.
8718 @node Proceeding with the Installation
8719 @subsection Proceeding with the Installation
8721 With the target partitions ready and the target root mounted on
8722 @file{/mnt}, we're ready to go. First, run:
8725 herd start cow-store /mnt
8728 This makes @file{/gnu/store} copy-on-write, such that packages added to it
8729 during the installation phase are written to the target disk on @file{/mnt}
8730 rather than kept in memory. This is necessary because the first phase of
8731 the @command{guix system init} command (see below) entails downloads or
8732 builds to @file{/gnu/store} which, initially, is an in-memory file system.
8734 Next, you have to edit a file and
8735 provide the declaration of the operating system to be installed. To
8736 that end, the installation system comes with three text editors. We
8737 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
8738 supports syntax highlighting and parentheses matching; other editors
8739 include GNU Zile (an Emacs clone), and
8740 nvi (a clone of the original BSD @command{vi} editor).
8741 We strongly recommend storing that file on the target root file system, say,
8742 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
8743 configuration file once you have rebooted into the newly-installed system.
8745 @xref{Using the Configuration System}, for an overview of the
8746 configuration file. The example configurations discussed in that
8747 section are available under @file{/etc/configuration} in the
8748 installation image. Thus, to get started with a system configuration
8749 providing a graphical display server (a ``desktop'' system), you can run
8750 something along these lines:
8754 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
8755 # nano /mnt/etc/config.scm
8758 You should pay attention to what your configuration file contains, and
8763 Make sure the @code{bootloader-configuration} form refers to the target
8764 you want to install GRUB on. It should mention @code{grub-bootloader} if
8765 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
8766 for newer UEFI systems. For legacy systems, the @code{target} field
8767 names a device, like @code{/dev/sda}; for UEFI systems it names a path
8768 to a mounted EFI partition, like @code{/boot/efi}, and do make sure the
8769 path is actually mounted.
8772 Be sure that your file system labels match the value of their respective
8773 @code{device} fields in your @code{file-system} configuration, assuming
8774 your @code{file-system} configuration sets the value of @code{title} to
8778 If there are encrypted or RAID partitions, make sure to add a
8779 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
8782 Once you are done preparing the configuration file, the new system must
8783 be initialized (remember that the target root file system is mounted
8787 guix system init /mnt/etc/config.scm /mnt
8791 This copies all the necessary files and installs GRUB on
8792 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
8793 more information, @pxref{Invoking guix system}. This command may trigger
8794 downloads or builds of missing packages, which can take some time.
8796 Once that command has completed---and hopefully succeeded!---you can run
8797 @command{reboot} and boot into the new system. The @code{root} password
8798 in the new system is initially empty; other users' passwords need to be
8799 initialized by running the @command{passwd} command as @code{root},
8800 unless your configuration specifies otherwise
8801 (@pxref{user-account-password, user account passwords}).
8803 @cindex upgrading GuixSD
8804 From then on, you can update GuixSD whenever you want by running
8805 @command{guix pull} as @code{root} (@pxref{Invoking guix pull}), and
8806 then running @command{guix system reconfigure} to build a new system
8807 generation with the latest packages and services (@pxref{Invoking guix
8808 system}). We recommend doing that regularly so that your system
8809 includes the latest security updates (@pxref{Security Updates}).
8811 Join us on @code{#guix} on the Freenode IRC network or on
8812 @file{guix-devel@@gnu.org} to share your experience---good or not so
8815 @node Installing GuixSD in a VM
8816 @subsection Installing GuixSD in a Virtual Machine
8818 @cindex virtual machine, GuixSD installation
8819 @cindex virtual private server (VPS)
8820 @cindex VPS (virtual private server)
8821 If you'd like to install GuixSD in a virtual machine (VM) or on a
8822 virtual private server (VPS) rather than on your beloved machine, this
8825 To boot a @uref{http://qemu.org/,QEMU} VM for installing GuixSD in a
8826 disk image, follow these steps:
8830 First, retrieve and decompress the GuixSD installation image as
8831 described previously (@pxref{USB Stick and DVD Installation}).
8834 Create a disk image that will hold the installed system. To make a
8835 qcow2-formatted disk image, use the @command{qemu-img} command:
8838 qemu-img create -f qcow2 guixsd.img 50G
8841 The resulting file will be much smaller than 50 GB (typically less than
8842 1 MB), but it will grow as the virtualized storage device is filled up.
8845 Boot the USB installation image in an VM:
8848 qemu-system-x86_64 -m 1024 -smp 1 \
8849 -net user -net nic,model=virtio -boot menu=on \
8850 -drive file=guixsd-install-@value{VERSION}.@var{system}.iso \
8851 -drive file=guixsd.img
8854 The ordering of the drives matters.
8856 In the VM console, quickly press the @kbd{F12} key to enter the boot
8857 menu. Then press the @kbd{2} key and the @kbd{RET} key to validate your
8861 You're now root in the VM, proceed with the installation process.
8862 @xref{Preparing for Installation}, and follow the instructions.
8865 Once installation is complete, you can boot the system that's on your
8866 @file{guixsd.img} image. @xref{Running GuixSD in a VM}, for how to do
8869 @node Building the Installation Image
8870 @subsection Building the Installation Image
8872 @cindex installation image
8873 The installation image described above was built using the @command{guix
8874 system} command, specifically:
8877 guix system disk-image gnu/system/install.scm
8880 Have a look at @file{gnu/system/install.scm} in the source tree,
8881 and see also @ref{Invoking guix system} for more information
8882 about the installation image.
8884 @subsection Building the Installation Image for ARM Boards
8886 Many ARM boards require a specific variant of the
8887 @uref{http://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
8889 If you build a disk image and the bootloader is not available otherwise
8890 (on another boot drive etc), it's advisable to build an image that
8891 includes the bootloader, specifically:
8894 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
8897 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
8898 board, a list of possible boards will be printed.
8900 @node System Configuration
8901 @section System Configuration
8903 @cindex system configuration
8904 The Guix System Distribution supports a consistent whole-system configuration
8905 mechanism. By that we mean that all aspects of the global system
8906 configuration---such as the available system services, timezone and
8907 locale settings, user accounts---are declared in a single place. Such
8908 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
8910 One of the advantages of putting all the system configuration under the
8911 control of Guix is that it supports transactional system upgrades, and
8912 makes it possible to roll back to a previous system instantiation,
8913 should something go wrong with the new one (@pxref{Features}). Another
8914 advantage is that it makes it easy to replicate the exact same configuration
8915 across different machines, or at different points in time, without
8916 having to resort to additional administration tools layered on top of
8917 the own tools of the system.
8918 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
8920 This section describes this mechanism. First we focus on the system
8921 administrator's viewpoint---explaining how the system is configured and
8922 instantiated. Then we show how this mechanism can be extended, for
8923 instance to support new system services.
8926 * Using the Configuration System:: Customizing your GNU system.
8927 * operating-system Reference:: Detail of operating-system declarations.
8928 * File Systems:: Configuring file system mounts.
8929 * Mapped Devices:: Block device extra processing.
8930 * User Accounts:: Specifying user accounts.
8931 * Locales:: Language and cultural convention settings.
8932 * Services:: Specifying system services.
8933 * Setuid Programs:: Programs running with root privileges.
8934 * X.509 Certificates:: Authenticating HTTPS servers.
8935 * Name Service Switch:: Configuring libc's name service switch.
8936 * Initial RAM Disk:: Linux-Libre bootstrapping.
8937 * Bootloader Configuration:: Configuring the boot loader.
8938 * Invoking guix system:: Instantiating a system configuration.
8939 * Running GuixSD in a VM:: How to run GuixSD in a virtual machine.
8940 * Defining Services:: Adding new service definitions.
8943 @node Using the Configuration System
8944 @subsection Using the Configuration System
8946 The operating system is configured by providing an
8947 @code{operating-system} declaration in a file that can then be passed to
8948 the @command{guix system} command (@pxref{Invoking guix system}). A
8949 simple setup, with the default system services, the default Linux-Libre
8950 kernel, initial RAM disk, and boot loader looks like this:
8952 @findex operating-system
8954 @include os-config-bare-bones.texi
8957 This example should be self-describing. Some of the fields defined
8958 above, such as @code{host-name} and @code{bootloader}, are mandatory.
8959 Others, such as @code{packages} and @code{services}, can be omitted, in
8960 which case they get a default value.
8962 Below we discuss the effect of some of the most important fields
8963 (@pxref{operating-system Reference}, for details about all the available
8964 fields), and how to @dfn{instantiate} the operating system using
8965 @command{guix system}.
8967 @unnumberedsubsubsec Globally-Visible Packages
8969 @vindex %base-packages
8970 The @code{packages} field lists packages that will be globally visible
8971 on the system, for all user accounts---i.e., in every user's @code{PATH}
8972 environment variable---in addition to the per-user profiles
8973 (@pxref{Invoking guix package}). The @var{%base-packages} variable
8974 provides all the tools one would expect for basic user and administrator
8975 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
8976 the GNU Zile lightweight text editor, @command{find}, @command{grep},
8977 etc. The example above adds GNU@tie{}Screen and OpenSSH to those,
8978 taken from the @code{(gnu packages screen)} and @code{(gnu packages ssh)}
8979 modules (@pxref{Package Modules}). The
8980 @code{(list package output)} syntax can be used to add a specific output
8984 (use-modules (gnu packages))
8985 (use-modules (gnu packages dns))
8989 (packages (cons (list bind "utils")
8993 @findex specification->package
8994 Referring to packages by variable name, like @code{bind} above, has
8995 the advantage of being unambiguous; it also allows typos and such to be
8996 diagnosed right away as ``unbound variables''. The downside is that one
8997 needs to know which module defines which package, and to augment the
8998 @code{use-package-modules} line accordingly. To avoid that, one can use
8999 the @code{specification->package} procedure of the @code{(gnu packages)}
9000 module, which returns the best package for a given name or name and
9004 (use-modules (gnu packages))
9008 (packages (append (map specification->package
9009 '("tcpdump" "htop" "gnupg@@2.0"))
9013 @unnumberedsubsubsec System Services
9016 @vindex %base-services
9017 The @code{services} field lists @dfn{system services} to be made
9018 available when the system starts (@pxref{Services}).
9019 The @code{operating-system} declaration above specifies that, in
9020 addition to the basic services, we want the @command{lshd} secure shell
9021 daemon listening on port 2222 (@pxref{Networking Services,
9022 @code{lsh-service}}). Under the hood,
9023 @code{lsh-service} arranges so that @code{lshd} is started with the
9024 right command-line options, possibly with supporting configuration files
9025 generated as needed (@pxref{Defining Services}).
9027 @cindex customization, of services
9028 @findex modify-services
9029 Occasionally, instead of using the base services as is, you will want to
9030 customize them. To do this, use @code{modify-services} (@pxref{Service
9031 Reference, @code{modify-services}}) to modify the list.
9033 For example, suppose you want to modify @code{guix-daemon} and Mingetty
9034 (the console log-in) in the @var{%base-services} list (@pxref{Base
9035 Services, @code{%base-services}}). To do that, you can write the
9036 following in your operating system declaration:
9039 (define %my-services
9040 ;; My very own list of services.
9041 (modify-services %base-services
9042 (guix-service-type config =>
9045 (use-substitutes? #f)
9046 (extra-options '("--gc-keep-derivations"))))
9047 (mingetty-service-type config =>
9048 (mingetty-configuration
9049 (inherit config)))))
9053 (services %my-services))
9056 This changes the configuration---i.e., the service parameters---of the
9057 @code{guix-service-type} instance, and that of all the
9058 @code{mingetty-service-type} instances in the @var{%base-services} list.
9059 Observe how this is accomplished: first, we arrange for the original
9060 configuration to be bound to the identifier @code{config} in the
9061 @var{body}, and then we write the @var{body} so that it evaluates to the
9062 desired configuration. In particular, notice how we use @code{inherit}
9063 to create a new configuration which has the same values as the old
9064 configuration, but with a few modifications.
9066 @cindex encrypted disk
9067 The configuration for a typical ``desktop'' usage, with an encrypted
9068 root partition, the X11 display
9069 server, GNOME and Xfce (users can choose which of these desktop
9070 environments to use at the log-in screen by pressing @kbd{F1}), network
9071 management, power management, and more, would look like this:
9074 @include os-config-desktop.texi
9078 A graphical UEFI system with a choice of lightweight window managers
9079 instead of full-blown desktop environments would look like this:
9082 @include os-config-lightweight-desktop.texi
9085 This example refers to the @file{/boot/efi} file system by its UUID,
9086 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
9087 as returned by the @command{blkid} command.
9089 @xref{Desktop Services}, for the exact list of services provided by
9090 @var{%desktop-services}. @xref{X.509 Certificates}, for background
9091 information about the @code{nss-certs} package that is used here.
9093 Again, @var{%desktop-services} is just a list of service objects. If
9094 you want to remove services from there, you can do so using the
9095 procedures for list filtering (@pxref{SRFI-1 Filtering and
9096 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
9097 following expression returns a list that contains all the services in
9098 @var{%desktop-services} minus the Avahi service:
9101 (remove (lambda (service)
9102 (eq? (service-kind service) avahi-service-type))
9106 @unnumberedsubsubsec Instantiating the System
9108 Assuming the @code{operating-system} declaration
9109 is stored in the @file{my-system-config.scm}
9110 file, the @command{guix system reconfigure my-system-config.scm} command
9111 instantiates that configuration, and makes it the default GRUB boot
9112 entry (@pxref{Invoking guix system}).
9114 The normal way to change the system configuration is by updating this
9115 file and re-running @command{guix system reconfigure}. One should never
9116 have to touch files in @file{/etc} or to run commands that modify the
9117 system state such as @command{useradd} or @command{grub-install}. In
9118 fact, you must avoid that since that would not only void your warranty
9119 but also prevent you from rolling back to previous versions of your
9120 system, should you ever need to.
9122 @cindex roll-back, of the operating system
9123 Speaking of roll-back, each time you run @command{guix system
9124 reconfigure}, a new @dfn{generation} of the system is created---without
9125 modifying or deleting previous generations. Old system generations get
9126 an entry in the bootloader boot menu, allowing you to boot them in case
9127 something went wrong with the latest generation. Reassuring, no? The
9128 @command{guix system list-generations} command lists the system
9129 generations available on disk. It is also possible to roll back the
9130 system via the commands @command{guix system roll-back} and
9131 @command{guix system switch-generation}.
9133 Although the command @command{guix system reconfigure} will not modify
9134 previous generations, must take care when the current generation is not
9135 the latest (e.g., after invoking @command{guix system roll-back}), since
9136 the operation might overwrite a later generation (@pxref{Invoking guix
9139 @unnumberedsubsubsec The Programming Interface
9141 At the Scheme level, the bulk of an @code{operating-system} declaration
9142 is instantiated with the following monadic procedure (@pxref{The Store
9145 @deffn {Monadic Procedure} operating-system-derivation os
9146 Return a derivation that builds @var{os}, an @code{operating-system}
9147 object (@pxref{Derivations}).
9149 The output of the derivation is a single directory that refers to all
9150 the packages, configuration files, and other supporting files needed to
9151 instantiate @var{os}.
9154 This procedure is provided by the @code{(gnu system)} module. Along
9155 with @code{(gnu services)} (@pxref{Services}), this module contains the
9156 guts of GuixSD. Make sure to visit it!
9159 @node operating-system Reference
9160 @subsection @code{operating-system} Reference
9162 This section summarizes all the options available in
9163 @code{operating-system} declarations (@pxref{Using the Configuration
9166 @deftp {Data Type} operating-system
9167 This is the data type representing an operating system configuration.
9168 By that, we mean all the global system configuration, not per-user
9169 configuration (@pxref{Using the Configuration System}).
9172 @item @code{kernel} (default: @var{linux-libre})
9173 The package object of the operating system kernel to use@footnote{Currently
9174 only the Linux-libre kernel is supported. In the future, it will be
9175 possible to use the GNU@tie{}Hurd.}.
9177 @item @code{kernel-arguments} (default: @code{'()})
9178 List of strings or gexps representing additional arguments to pass on
9179 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
9181 @item @code{bootloader}
9182 The system bootloader configuration object. @xref{Bootloader Configuration}.
9184 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
9186 @cindex initial RAM disk
9187 The list of Linux kernel modules that need to be available in the
9188 initial RAM disk. @xref{Initial RAM Disk}.
9190 @item @code{initrd} (default: @code{base-initrd})
9191 A monadic procedure that returns an initial RAM disk for the Linux
9192 kernel. This field is provided to support low-level customization and
9193 should rarely be needed for casual use. @xref{Initial RAM Disk}.
9195 @item @code{firmware} (default: @var{%base-firmware})
9197 List of firmware packages loadable by the operating system kernel.
9199 The default includes firmware needed for Atheros- and Broadcom-based
9200 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
9201 respectively). @xref{Hardware Considerations}, for more info on
9204 @item @code{host-name}
9207 @item @code{hosts-file}
9209 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
9210 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
9211 Reference Manual}). The default is a file with entries for
9212 @code{localhost} and @var{host-name}.
9214 @item @code{mapped-devices} (default: @code{'()})
9215 A list of mapped devices. @xref{Mapped Devices}.
9217 @item @code{file-systems}
9218 A list of file systems. @xref{File Systems}.
9220 @item @code{swap-devices} (default: @code{'()})
9221 @cindex swap devices
9222 A list of strings identifying devices or files to be used for ``swap
9223 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
9224 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
9225 It is possible to specify a swap file in a file system on a mapped
9226 device, provided that the necessary device mapping and file system are
9227 also specified. @xref{Mapped Devices} and @ref{File Systems}.
9229 @item @code{users} (default: @code{%base-user-accounts})
9230 @itemx @code{groups} (default: @var{%base-groups})
9231 List of user accounts and groups. @xref{User Accounts}.
9233 If the @code{users} list lacks a user account with UID@tie{}0, a
9234 ``root'' account with UID@tie{}0 is automatically added.
9236 @item @code{skeletons} (default: @code{(default-skeletons)})
9237 A list target file name/file-like object tuples (@pxref{G-Expressions,
9238 file-like objects}). These are the skeleton files that will be added to
9239 the home directory of newly-created user accounts.
9241 For instance, a valid value may look like this:
9244 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
9245 (".guile" ,(plain-file "guile"
9246 "(use-modules (ice-9 readline))
9247 (activate-readline)")))
9250 @item @code{issue} (default: @var{%default-issue})
9251 A string denoting the contents of the @file{/etc/issue} file, which is
9252 displayed when users log in on a text console.
9254 @item @code{packages} (default: @var{%base-packages})
9255 The set of packages installed in the global profile, which is accessible
9256 at @file{/run/current-system/profile}.
9258 The default set includes core utilities and it is good practice to
9259 install non-core utilities in user profiles (@pxref{Invoking guix
9262 @item @code{timezone}
9263 A timezone identifying string---e.g., @code{"Europe/Paris"}.
9265 You can run the @command{tzselect} command to find out which timezone
9266 string corresponds to your region. Choosing an invalid timezone name
9267 causes @command{guix system} to fail.
9269 @item @code{locale} (default: @code{"en_US.utf8"})
9270 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
9271 Library Reference Manual}). @xref{Locales}, for more information.
9273 @item @code{locale-definitions} (default: @var{%default-locale-definitions})
9274 The list of locale definitions to be compiled and that may be used at
9275 run time. @xref{Locales}.
9277 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
9278 The list of GNU@tie{}libc packages whose locale data and tools are used
9279 to build the locale definitions. @xref{Locales}, for compatibility
9280 considerations that justify this option.
9282 @item @code{name-service-switch} (default: @var{%default-nss})
9283 Configuration of the libc name service switch (NSS)---a
9284 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
9287 @item @code{services} (default: @var{%base-services})
9288 A list of service objects denoting system services. @xref{Services}.
9290 @item @code{pam-services} (default: @code{(base-pam-services)})
9292 @cindex pluggable authentication modules
9293 Linux @dfn{pluggable authentication module} (PAM) services.
9294 @c FIXME: Add xref to PAM services section.
9296 @item @code{setuid-programs} (default: @var{%setuid-programs})
9297 List of string-valued G-expressions denoting setuid programs.
9298 @xref{Setuid Programs}.
9300 @item @code{sudoers-file} (default: @var{%sudoers-specification})
9301 @cindex sudoers file
9302 The contents of the @file{/etc/sudoers} file as a file-like object
9303 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
9305 This file specifies which users can use the @command{sudo} command, what
9306 they are allowed to do, and what privileges they may gain. The default
9307 is that only @code{root} and members of the @code{wheel} group may use
9314 @subsection File Systems
9316 The list of file systems to be mounted is specified in the
9317 @code{file-systems} field of the operating system declaration
9318 (@pxref{Using the Configuration System}). Each file system is declared
9319 using the @code{file-system} form, like this:
9323 (mount-point "/home")
9324 (device "/dev/sda3")
9328 As usual, some of the fields are mandatory---those shown in the example
9329 above---while others can be omitted. These are described below.
9331 @deftp {Data Type} file-system
9332 Objects of this type represent file systems to be mounted. They
9333 contain the following members:
9337 This is a string specifying the type of the file system---e.g.,
9340 @item @code{mount-point}
9341 This designates the place where the file system is to be mounted.
9344 This names the ``source'' of the file system. It can be one of three
9345 things: a file system label, a file system UUID, or the name of a
9346 @file{/dev} node. Labels and UUIDs offer a way to refer to file
9347 systems without having to hard-code their actual device
9348 name@footnote{Note that, while it is tempting to use
9349 @file{/dev/disk/by-uuid} and similar device names to achieve the same
9350 result, this is not recommended: These special device nodes are created
9351 by the udev daemon and may be unavailable at the time the device is
9354 @findex file-system-label
9355 File system labels are created using the @code{file-system-label}
9356 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
9357 plain strings. Here's an example of a file system referred to by its
9358 label, as shown by the @command{e2label} command:
9362 (mount-point "/home")
9364 (device (file-system-label "my-home")))
9368 UUIDs are converted from their string representation (as shown by the
9369 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
9370 @code{uuid} form expects 16-byte UUIDs as defined in
9371 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
9372 form of UUID used by the ext2 family of file systems and others, but it
9373 is different from ``UUIDs'' found in FAT file systems, for instance.},
9378 (mount-point "/home")
9380 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
9383 When the source of a file system is a mapped device (@pxref{Mapped
9384 Devices}), its @code{device} field @emph{must} refer to the mapped
9385 device name---e.g., @file{"/dev/mapper/root-partition"}.
9386 This is required so that
9387 the system knows that mounting the file system depends on having the
9388 corresponding device mapping established.
9390 @item @code{flags} (default: @code{'()})
9391 This is a list of symbols denoting mount flags. Recognized flags
9392 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
9393 access to special files), @code{no-suid} (ignore setuid and setgid
9394 bits), and @code{no-exec} (disallow program execution.)
9396 @item @code{options} (default: @code{#f})
9397 This is either @code{#f}, or a string denoting mount options.
9399 @item @code{mount?} (default: @code{#t})
9400 This value indicates whether to automatically mount the file system when
9401 the system is brought up. When set to @code{#f}, the file system gets
9402 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
9403 is not automatically mounted.
9405 @item @code{needed-for-boot?} (default: @code{#f})
9406 This Boolean value indicates whether the file system is needed when
9407 booting. If that is true, then the file system is mounted when the
9408 initial RAM disk (initrd) is loaded. This is always the case, for
9409 instance, for the root file system.
9411 @item @code{check?} (default: @code{#t})
9412 This Boolean indicates whether the file system needs to be checked for
9413 errors before being mounted.
9415 @item @code{create-mount-point?} (default: @code{#f})
9416 When true, the mount point is created if it does not exist yet.
9418 @item @code{dependencies} (default: @code{'()})
9419 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
9420 representing file systems that must be mounted or mapped devices that
9421 must be opened before (and unmounted or closed after) this one.
9423 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
9424 a dependency of @file{/sys/fs/cgroup/cpu} and
9425 @file{/sys/fs/cgroup/memory}.
9427 Another example is a file system that depends on a mapped device, for
9428 example for an encrypted partition (@pxref{Mapped Devices}).
9432 The @code{(gnu system file-systems)} exports the following useful
9435 @defvr {Scheme Variable} %base-file-systems
9436 These are essential file systems that are required on normal systems,
9437 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
9438 below.) Operating system declarations should always contain at least
9442 @defvr {Scheme Variable} %pseudo-terminal-file-system
9443 This is the file system to be mounted as @file{/dev/pts}. It supports
9444 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
9445 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
9446 Manual}). Pseudo-terminals are used by terminal emulators such as
9450 @defvr {Scheme Variable} %shared-memory-file-system
9451 This file system is mounted as @file{/dev/shm} and is used to support
9452 memory sharing across processes (@pxref{Memory-mapped I/O,
9453 @code{shm_open},, libc, The GNU C Library Reference Manual}).
9456 @defvr {Scheme Variable} %immutable-store
9457 This file system performs a read-only ``bind mount'' of
9458 @file{/gnu/store}, making it read-only for all the users including
9459 @code{root}. This prevents against accidental modification by software
9460 running as @code{root} or by system administrators.
9462 The daemon itself is still able to write to the store: it remounts it
9463 read-write in its own ``name space.''
9466 @defvr {Scheme Variable} %binary-format-file-system
9467 The @code{binfmt_misc} file system, which allows handling of arbitrary
9468 executable file types to be delegated to user space. This requires the
9469 @code{binfmt.ko} kernel module to be loaded.
9472 @defvr {Scheme Variable} %fuse-control-file-system
9473 The @code{fusectl} file system, which allows unprivileged users to mount
9474 and unmount user-space FUSE file systems. This requires the
9475 @code{fuse.ko} kernel module to be loaded.
9478 @node Mapped Devices
9479 @subsection Mapped Devices
9481 @cindex device mapping
9482 @cindex mapped devices
9483 The Linux kernel has a notion of @dfn{device mapping}: a block device,
9484 such as a hard disk partition, can be @dfn{mapped} into another device,
9485 usually in @code{/dev/mapper/},
9486 with additional processing over the data that flows through
9487 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
9488 concept of a ``mapped device'' and that of a file system: both boil down
9489 to @emph{translating} input/output operations made on a file to
9490 operations on its backing store. Thus, the Hurd implements mapped
9491 devices, like file systems, using the generic @dfn{translator} mechanism
9492 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
9493 typical example is encryption device mapping: all writes to the mapped
9494 device are encrypted, and all reads are deciphered, transparently.
9495 Guix extends this notion by considering any device or set of devices that
9496 are @dfn{transformed} in some way to create a new device; for instance,
9497 RAID devices are obtained by @dfn{assembling} several other devices, such
9498 as hard disks or partitions, into a new one that behaves as one partition.
9499 Other examples, not yet implemented, are LVM logical volumes.
9501 Mapped devices are declared using the @code{mapped-device} form,
9502 defined as follows; for examples, see below.
9504 @deftp {Data Type} mapped-device
9505 Objects of this type represent device mappings that will be made when
9506 the system boots up.
9510 This is either a string specifying the name of the block device to be mapped,
9511 such as @code{"/dev/sda3"}, or a list of such strings when several devices
9512 need to be assembled for creating a new one.
9515 This string specifies the name of the resulting mapped device. For
9516 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
9517 specifying @code{"my-partition"} leads to the creation of
9518 the @code{"/dev/mapper/my-partition"} device.
9519 For RAID devices of type @code{raid-device-mapping}, the full device name
9520 such as @code{"/dev/md0"} needs to be given.
9523 This must be a @code{mapped-device-kind} object, which specifies how
9524 @var{source} is mapped to @var{target}.
9528 @defvr {Scheme Variable} luks-device-mapping
9529 This defines LUKS block device encryption using the @command{cryptsetup}
9530 command from the package with the same name. It relies on the
9531 @code{dm-crypt} Linux kernel module.
9534 @defvr {Scheme Variable} raid-device-mapping
9535 This defines a RAID device, which is assembled using the @code{mdadm}
9536 command from the package with the same name. It requires a Linux kernel
9537 module for the appropriate RAID level to be loaded, such as @code{raid456}
9538 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
9541 @cindex disk encryption
9543 The following example specifies a mapping from @file{/dev/sda3} to
9544 @file{/dev/mapper/home} using LUKS---the
9545 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
9546 standard mechanism for disk encryption.
9547 The @file{/dev/mapper/home}
9548 device can then be used as the @code{device} of a @code{file-system}
9549 declaration (@pxref{File Systems}).
9553 (source "/dev/sda3")
9555 (type luks-device-mapping))
9558 Alternatively, to become independent of device numbering, one may obtain
9559 the LUKS UUID (@dfn{unique identifier}) of the source device by a
9563 cryptsetup luksUUID /dev/sda3
9566 and use it as follows:
9570 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
9572 (type luks-device-mapping))
9575 @cindex swap encryption
9576 It is also desirable to encrypt swap space, since swap space may contain
9577 sensitive data. One way to accomplish that is to use a swap file in a
9578 file system on a device mapped via LUKS encryption. In this way, the
9579 swap file is encrypted because the entire device is encrypted.
9580 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
9582 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
9583 may be declared as follows:
9587 (source (list "/dev/sda1" "/dev/sdb1"))
9589 (type raid-device-mapping))
9592 The @file{/dev/md0} device can then be used as the @code{device} of a
9593 @code{file-system} declaration (@pxref{File Systems}).
9594 Note that the RAID level need not be given; it is chosen during the
9595 initial creation and formatting of the RAID device and is determined
9596 automatically later.
9600 @subsection User Accounts
9604 @cindex user accounts
9605 User accounts and groups are entirely managed through the
9606 @code{operating-system} declaration. They are specified with the
9607 @code{user-account} and @code{user-group} forms:
9613 (supplementary-groups '("wheel" ;allow use of sudo, etc.
9615 "video" ;video devices such as webcams
9616 "cdrom")) ;the good ol' CD-ROM
9617 (comment "Bob's sister")
9618 (home-directory "/home/alice"))
9621 When booting or upon completion of @command{guix system reconfigure},
9622 the system ensures that only the user accounts and groups specified in
9623 the @code{operating-system} declaration exist, and with the specified
9624 properties. Thus, account or group creations or modifications made by
9625 directly invoking commands such as @command{useradd} are lost upon
9626 reconfiguration or reboot. This ensures that the system remains exactly
9629 @deftp {Data Type} user-account
9630 Objects of this type represent user accounts. The following members may
9635 The name of the user account.
9639 This is the name (a string) or identifier (a number) of the user group
9640 this account belongs to.
9642 @item @code{supplementary-groups} (default: @code{'()})
9643 Optionally, this can be defined as a list of group names that this
9646 @item @code{uid} (default: @code{#f})
9647 This is the user ID for this account (a number), or @code{#f}. In the
9648 latter case, a number is automatically chosen by the system when the
9651 @item @code{comment} (default: @code{""})
9652 A comment about the account, such as the account owner's full name.
9654 @item @code{home-directory}
9655 This is the name of the home directory for the account.
9657 @item @code{create-home-directory?} (default: @code{#t})
9658 Indicates whether the home directory of this account should be created
9659 if it does not exist yet.
9661 @item @code{shell} (default: Bash)
9662 This is a G-expression denoting the file name of a program to be used as
9663 the shell (@pxref{G-Expressions}).
9665 @item @code{system?} (default: @code{#f})
9666 This Boolean value indicates whether the account is a ``system''
9667 account. System accounts are sometimes treated specially; for instance,
9668 graphical login managers do not list them.
9670 @anchor{user-account-password}
9671 @item @code{password} (default: @code{#f})
9672 You would normally leave this field to @code{#f}, initialize user
9673 passwords as @code{root} with the @command{passwd} command, and then let
9674 users change it with @command{passwd}. Passwords set with
9675 @command{passwd} are of course preserved across reboot and
9678 If you @emph{do} want to have a preset password for an account, then
9679 this field must contain the encrypted password, as a string.
9680 @xref{crypt,,, libc, The GNU C Library Reference Manual}, for more information
9681 on password encryption, and @ref{Encryption,,, guile, GNU Guile Reference
9682 Manual}, for information on Guile's @code{crypt} procedure.
9688 User group declarations are even simpler:
9691 (user-group (name "students"))
9694 @deftp {Data Type} user-group
9695 This type is for, well, user groups. There are just a few fields:
9699 The name of the group.
9701 @item @code{id} (default: @code{#f})
9702 The group identifier (a number). If @code{#f}, a new number is
9703 automatically allocated when the group is created.
9705 @item @code{system?} (default: @code{#f})
9706 This Boolean value indicates whether the group is a ``system'' group.
9707 System groups have low numerical IDs.
9709 @item @code{password} (default: @code{#f})
9710 What, user groups can have a password? Well, apparently yes. Unless
9711 @code{#f}, this field specifies the password of the group.
9716 For convenience, a variable lists all the basic user groups one may
9719 @defvr {Scheme Variable} %base-groups
9720 This is the list of basic user groups that users and/or packages expect
9721 to be present on the system. This includes groups such as ``root'',
9722 ``wheel'', and ``users'', as well as groups used to control access to
9723 specific devices such as ``audio'', ``disk'', and ``cdrom''.
9726 @defvr {Scheme Variable} %base-user-accounts
9727 This is the list of basic system accounts that programs may expect to
9728 find on a GNU/Linux system, such as the ``nobody'' account.
9730 Note that the ``root'' account is not included here. It is a
9731 special-case and is automatically added whether or not it is specified.
9738 A @dfn{locale} defines cultural conventions for a particular language
9739 and region of the world (@pxref{Locales,,, libc, The GNU C Library
9740 Reference Manual}). Each locale has a name that typically has the form
9741 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
9742 @code{fr_LU.utf8} designates the locale for the French language, with
9743 cultural conventions from Luxembourg, and using the UTF-8 encoding.
9745 @cindex locale definition
9746 Usually, you will want to specify the default locale for the machine
9747 using the @code{locale} field of the @code{operating-system} declaration
9748 (@pxref{operating-system Reference, @code{locale}}).
9750 The selected locale is automatically added to the @dfn{locale
9751 definitions} known to the system if needed, with its codeset inferred
9752 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
9753 @code{UTF-8} codeset. Additional locale definitions can be specified in
9754 the @code{locale-definitions} slot of @code{operating-system}---this is
9755 useful, for instance, if the codeset could not be inferred from the
9756 locale name. The default set of locale definitions includes some widely
9757 used locales, but not all the available locales, in order to save space.
9759 For instance, to add the North Frisian locale for Germany, the value of
9763 (cons (locale-definition
9764 (name "fy_DE.utf8") (source "fy_DE"))
9765 %default-locale-definitions)
9768 Likewise, to save space, one might want @code{locale-definitions} to
9769 list only the locales that are actually used, as in:
9772 (list (locale-definition
9773 (name "ja_JP.eucjp") (source "ja_JP")
9774 (charset "EUC-JP")))
9778 The compiled locale definitions are available at
9779 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
9780 version, which is the default location where the GNU@tie{}libc provided
9781 by Guix looks for locale data. This can be overridden using the
9782 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
9783 @code{LOCPATH} and locale packages}).
9785 The @code{locale-definition} form is provided by the @code{(gnu system
9786 locale)} module. Details are given below.
9788 @deftp {Data Type} locale-definition
9789 This is the data type of a locale definition.
9794 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
9795 Reference Manual}, for more information on locale names.
9798 The name of the source for that locale. This is typically the
9799 @code{@var{language}_@var{territory}} part of the locale name.
9801 @item @code{charset} (default: @code{"UTF-8"})
9802 The ``character set'' or ``code set'' for that locale,
9803 @uref{http://www.iana.org/assignments/character-sets, as defined by
9809 @defvr {Scheme Variable} %default-locale-definitions
9810 A list of commonly used UTF-8 locales, used as the default
9811 value of the @code{locale-definitions} field of @code{operating-system}
9815 @cindex normalized codeset in locale names
9816 These locale definitions use the @dfn{normalized codeset} for the part
9817 that follows the dot in the name (@pxref{Using gettextized software,
9818 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
9819 instance it has @code{uk_UA.utf8} but @emph{not}, say,
9823 @subsubsection Locale Data Compatibility Considerations
9825 @cindex incompatibility, of locale data
9826 @code{operating-system} declarations provide a @code{locale-libcs} field
9827 to specify the GNU@tie{}libc packages that are used to compile locale
9828 declarations (@pxref{operating-system Reference}). ``Why would I
9829 care?'', you may ask. Well, it turns out that the binary format of
9830 locale data is occasionally incompatible from one libc version to
9833 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
9834 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
9835 For instance, a program linked against libc version 2.21 is unable to
9836 read locale data produced with libc 2.22; worse, that program
9837 @emph{aborts} instead of simply ignoring the incompatible locale
9838 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
9839 the incompatible locale data, which is already an improvement.}.
9840 Similarly, a program linked against libc 2.22 can read most, but not
9841 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
9842 data is incompatible); thus calls to @code{setlocale} may fail, but
9843 programs will not abort.
9845 The ``problem'' in GuixSD is that users have a lot of freedom: They can
9846 choose whether and when to upgrade software in their profiles, and might
9847 be using a libc version different from the one the system administrator
9848 used to build the system-wide locale data.
9850 Fortunately, unprivileged users can also install their own locale data
9851 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
9852 @code{GUIX_LOCPATH} and locale packages}).
9854 Still, it is best if the system-wide locale data at
9855 @file{/run/current-system/locale} is built for all the libc versions
9856 actually in use on the system, so that all the programs can access
9857 it---this is especially crucial on a multi-user system. To do that, the
9858 administrator can specify several libc packages in the
9859 @code{locale-libcs} field of @code{operating-system}:
9862 (use-package-modules base)
9866 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
9869 This example would lead to a system containing locale definitions for
9870 both libc 2.21 and the current version of libc in
9871 @file{/run/current-system/locale}.
9875 @subsection Services
9877 @cindex system services
9878 An important part of preparing an @code{operating-system} declaration is
9879 listing @dfn{system services} and their configuration (@pxref{Using the
9880 Configuration System}). System services are typically daemons launched
9881 when the system boots, or other actions needed at that time---e.g.,
9882 configuring network access.
9884 GuixSD has a broad definition of ``service'' (@pxref{Service
9885 Composition}), but many services are managed by the GNU@tie{}Shepherd
9886 (@pxref{Shepherd Services}). On a running system, the @command{herd}
9887 command allows you to list the available services, show their status,
9888 start and stop them, or do other specific operations (@pxref{Jump
9889 Start,,, shepherd, The GNU Shepherd Manual}). For example:
9895 The above command, run as @code{root}, lists the currently defined
9896 services. The @command{herd doc} command shows a synopsis of the given
9901 Run libc's name service cache daemon (nscd).
9904 The @command{start}, @command{stop}, and @command{restart} sub-commands
9905 have the effect you would expect. For instance, the commands below stop
9906 the nscd service and restart the Xorg display server:
9910 Service nscd has been stopped.
9911 # herd restart xorg-server
9912 Service xorg-server has been stopped.
9913 Service xorg-server has been started.
9916 The following sections document the available services, starting with
9917 the core services, that may be used in an @code{operating-system}
9921 * Base Services:: Essential system services.
9922 * Scheduled Job Execution:: The mcron service.
9923 * Log Rotation:: The rottlog service.
9924 * Networking Services:: Network setup, SSH daemon, etc.
9925 * X Window:: Graphical display.
9926 * Printing Services:: Local and remote printer support.
9927 * Desktop Services:: D-Bus and desktop services.
9928 * Sound Services:: ALSA and Pulseaudio services.
9929 * Database Services:: SQL databases, key-value stores, etc.
9930 * Mail Services:: IMAP, POP3, SMTP, and all that.
9931 * Messaging Services:: Messaging services.
9932 * Telephony Services:: Telephony services.
9933 * Monitoring Services:: Monitoring services.
9934 * Kerberos Services:: Kerberos services.
9935 * Web Services:: Web servers.
9936 * Certificate Services:: TLS certificates via Let's Encrypt.
9937 * DNS Services:: DNS daemons.
9938 * VPN Services:: VPN daemons.
9939 * Network File System:: NFS related services.
9940 * Continuous Integration:: The Cuirass service.
9941 * Power Management Services:: Extending battery life.
9942 * Audio Services:: The MPD.
9943 * Virtualization Services:: Virtualization services.
9944 * Version Control Services:: Providing remote access to Git repositories.
9945 * Game Services:: Game servers.
9946 * Miscellaneous Services:: Other services.
9950 @subsubsection Base Services
9952 The @code{(gnu services base)} module provides definitions for the basic
9953 services that one expects from the system. The services exported by
9954 this module are listed below.
9956 @defvr {Scheme Variable} %base-services
9957 This variable contains a list of basic services (@pxref{Service Types
9958 and Services}, for more information on service objects) one would
9959 expect from the system: a login service (mingetty) on each tty, syslogd,
9960 the libc name service cache daemon (nscd), the udev device manager, and
9963 This is the default value of the @code{services} field of
9964 @code{operating-system} declarations. Usually, when customizing a
9965 system, you will want to append services to @var{%base-services}, like
9969 (cons* (avahi-service) (lsh-service) %base-services)
9973 @defvr {Scheme Variable} special-files-service-type
9974 This is the service that sets up ``special files'' such as
9975 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
9977 The value associated with @code{special-files-service-type} services
9978 must be a list of tuples where the first element is the ``special file''
9979 and the second element is its target. By default it is:
9981 @cindex @file{/bin/sh}
9982 @cindex @file{sh}, in @file{/bin}
9984 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
9987 @cindex @file{/usr/bin/env}
9988 @cindex @file{env}, in @file{/usr/bin}
9989 If you want to add, say, @code{/usr/bin/env} to your system, you can
9993 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
9994 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
9997 Since this is part of @code{%base-services}, you can use
9998 @code{modify-services} to customize the set of special files
9999 (@pxref{Service Reference, @code{modify-services}}). But the simple way
10000 to add a special file is @i{via} the @code{extra-special-file} procedure
10004 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
10005 Use @var{target} as the ``special file'' @var{file}.
10007 For example, adding the following lines to the @code{services} field of
10008 your operating system declaration leads to a @file{/usr/bin/env}
10012 (extra-special-file "/usr/bin/env"
10013 (file-append coreutils "/bin/env"))
10017 @deffn {Scheme Procedure} host-name-service @var{name}
10018 Return a service that sets the host name to @var{name}.
10021 @deffn {Scheme Procedure} login-service @var{config}
10022 Return a service to run login according to @var{config}, a
10023 @code{<login-configuration>} object, which specifies the message of the day,
10024 among other things.
10027 @deftp {Data Type} login-configuration
10028 This is the data type representing the configuration of login.
10033 @cindex message of the day
10034 A file-like object containing the ``message of the day''.
10036 @item @code{allow-empty-passwords?} (default: @code{#t})
10037 Allow empty passwords by default so that first-time users can log in when
10038 the 'root' account has just been created.
10043 @deffn {Scheme Procedure} mingetty-service @var{config}
10044 Return a service to run mingetty according to @var{config}, a
10045 @code{<mingetty-configuration>} object, which specifies the tty to run, among
10049 @deftp {Data Type} mingetty-configuration
10050 This is the data type representing the configuration of Mingetty, which
10051 provides the default implementation of virtual console log-in.
10056 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
10058 @item @code{auto-login} (default: @code{#f})
10059 When true, this field must be a string denoting the user name under
10060 which the system automatically logs in. When it is @code{#f}, a
10061 user name and password must be entered to log in.
10063 @item @code{login-program} (default: @code{#f})
10064 This must be either @code{#f}, in which case the default log-in program
10065 is used (@command{login} from the Shadow tool suite), or a gexp denoting
10066 the name of the log-in program.
10068 @item @code{login-pause?} (default: @code{#f})
10069 When set to @code{#t} in conjunction with @var{auto-login}, the user
10070 will have to press a key before the log-in shell is launched.
10072 @item @code{mingetty} (default: @var{mingetty})
10073 The Mingetty package to use.
10078 @deffn {Scheme Procedure} agetty-service @var{config}
10079 Return a service to run agetty according to @var{config}, an
10080 @code{<agetty-configuration>} object, which specifies the tty to run,
10081 among other things.
10084 @deftp {Data Type} agetty-configuration
10085 This is the data type representing the configuration of agetty, which
10086 implements virtual and serial console log-in. See the @code{agetty(8)}
10087 man page for more information.
10092 The name of the console this agetty runs on, as a string---e.g.,
10093 @code{"ttyS0"}. This argument is optional, it will default to
10094 a reasonable default serial port used by the kernel Linux.
10096 For this, if there is a value for an option @code{agetty.tty} in the kernel
10097 command line, agetty will extract the device name of the serial port
10098 from it and use that.
10100 If not and if there is a value for an option @code{console} with a tty in
10101 the Linux command line, agetty will extract the device name of the
10102 serial port from it and use that.
10104 In both cases, agetty will leave the other serial device settings
10105 (baud rate etc.) alone---in the hope that Linux pinned them to the
10108 @item @code{baud-rate} (default: @code{#f})
10109 A string containing a comma-separated list of one or more baud rates, in
10112 @item @code{term} (default: @code{#f})
10113 A string containing the value used for the @code{TERM} environment
10116 @item @code{eight-bits?} (default: @code{#f})
10117 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
10120 @item @code{auto-login} (default: @code{#f})
10121 When passed a login name, as a string, the specified user will be logged
10122 in automatically without prompting for their login name or password.
10124 @item @code{no-reset?} (default: @code{#f})
10125 When @code{#t}, don't reset terminal cflags (control modes).
10127 @item @code{host} (default: @code{#f})
10128 This accepts a string containing the "login_host", which will be written
10129 into the @file{/var/run/utmpx} file.
10131 @item @code{remote?} (default: @code{#f})
10132 When set to @code{#t} in conjunction with @var{host}, this will add an
10133 @code{-r} fakehost option to the command line of the login program
10134 specified in @var{login-program}.
10136 @item @code{flow-control?} (default: @code{#f})
10137 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
10139 @item @code{no-issue?} (default: @code{#f})
10140 When set to @code{#t}, the contents of the @file{/etc/issue} file will
10141 not be displayed before presenting the login prompt.
10143 @item @code{init-string} (default: @code{#f})
10144 This accepts a string that will be sent to the tty or modem before
10145 sending anything else. It can be used to initialize a modem.
10147 @item @code{no-clear?} (default: @code{#f})
10148 When set to @code{#t}, agetty will not clear the screen before showing
10151 @item @code{login-program} (default: (file-append shadow "/bin/login"))
10152 This must be either a gexp denoting the name of a log-in program, or
10153 unset, in which case the default value is the @command{login} from the
10156 @item @code{local-line} (default: @code{#f})
10157 Control the CLOCAL line flag. This accepts one of three symbols as
10158 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
10159 the default value chosen by agetty is @code{'auto}.
10161 @item @code{extract-baud?} (default: @code{#f})
10162 When set to @code{#t}, instruct agetty to try to extract the baud rate
10163 from the status messages produced by certain types of modems.
10165 @item @code{skip-login?} (default: @code{#f})
10166 When set to @code{#t}, do not prompt the user for a login name. This
10167 can be used with @var{login-program} field to use non-standard login
10170 @item @code{no-newline?} (default: @code{#f})
10171 When set to @code{#t}, do not print a newline before printing the
10172 @file{/etc/issue} file.
10174 @c Is this dangerous only when used with login-program, or always?
10175 @item @code{login-options} (default: @code{#f})
10176 This option accepts a string containing options that are passed to the
10177 login program. When used with the @var{login-program}, be aware that a
10178 malicious user could try to enter a login name containing embedded
10179 options that could be parsed by the login program.
10181 @item @code{login-pause} (default: @code{#f})
10182 When set to @code{#t}, wait for any key before showing the login prompt.
10183 This can be used in conjunction with @var{auto-login} to save memory by
10184 lazily spawning shells.
10186 @item @code{chroot} (default: @code{#f})
10187 Change root to the specified directory. This option accepts a directory
10190 @item @code{hangup?} (default: @code{#f})
10191 Use the Linux system call @code{vhangup} to do a virtual hangup of the
10192 specified terminal.
10194 @item @code{keep-baud?} (default: @code{#f})
10195 When set to @code{#t}, try to keep the existing baud rate. The baud
10196 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
10199 @item @code{timeout} (default: @code{#f})
10200 When set to an integer value, terminate if no user name could be read
10201 within @var{timeout} seconds.
10203 @item @code{detect-case?} (default: @code{#f})
10204 When set to @code{#t}, turn on support for detecting an uppercase-only
10205 terminal. This setting will detect a login name containing only
10206 uppercase letters as indicating an uppercase-only terminal and turn on
10207 some upper-to-lower case conversions. Note that this will not support
10208 Unicode characters.
10210 @item @code{wait-cr?} (default: @code{#f})
10211 When set to @code{#t}, wait for the user or modem to send a
10212 carriage-return or linefeed character before displaying
10213 @file{/etc/issue} or login prompt. This is typically used with the
10214 @var{init-string} option.
10216 @item @code{no-hints?} (default: @code{#f})
10217 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
10220 @item @code{no-hostname?} (default: @code{#f})
10221 By default, the hostname is printed. When this option is set to
10222 @code{#t}, no hostname will be shown at all.
10224 @item @code{long-hostname?} (default: @code{#f})
10225 By default, the hostname is only printed until the first dot. When this
10226 option is set to @code{#t}, the fully qualified hostname by
10227 @code{gethostname} or @code{getaddrinfo} is shown.
10229 @item @code{erase-characters} (default: @code{#f})
10230 This option accepts a string of additional characters that should be
10231 interpreted as backspace when the user types their login name.
10233 @item @code{kill-characters} (default: @code{#f})
10234 This option accepts a string that should be interpreted to mean "ignore
10235 all previous characters" (also called a "kill" character) when the types
10238 @item @code{chdir} (default: @code{#f})
10239 This option accepts, as a string, a directory path that will be changed
10242 @item @code{delay} (default: @code{#f})
10243 This options accepts, as an integer, the number of seconds to sleep
10244 before opening the tty and displaying the login prompt.
10246 @item @code{nice} (default: @code{#f})
10247 This option accepts, as an integer, the nice value with which to run the
10248 @command{login} program.
10250 @item @code{extra-options} (default: @code{'()})
10251 This option provides an "escape hatch" for the user to provide arbitrary
10252 command-line arguments to @command{agetty} as a list of strings.
10257 @deffn {Scheme Procedure} kmscon-service-type @var{config}
10258 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
10259 according to @var{config}, a @code{<kmscon-configuration>} object, which
10260 specifies the tty to run, among other things.
10263 @deftp {Data Type} kmscon-configuration
10264 This is the data type representing the configuration of Kmscon, which
10265 implements virtual console log-in.
10269 @item @code{virtual-terminal}
10270 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
10272 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
10273 A gexp denoting the name of the log-in program. The default log-in program is
10274 @command{login} from the Shadow tool suite.
10276 @item @code{login-arguments} (default: @code{'("-p")})
10277 A list of arguments to pass to @command{login}.
10279 @item @code{hardware-acceleration?} (default: #f)
10280 Whether to use hardware acceleration.
10282 @item @code{kmscon} (default: @var{kmscon})
10283 The Kmscon package to use.
10288 @cindex name service cache daemon
10290 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
10291 [#:name-services '()]
10292 Return a service that runs the libc name service cache daemon (nscd) with the
10293 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
10294 Service Switch}, for an example.
10297 @defvr {Scheme Variable} %nscd-default-configuration
10298 This is the default @code{<nscd-configuration>} value (see below) used
10299 by @code{nscd-service}. It uses the caches defined by
10300 @var{%nscd-default-caches}; see below.
10303 @deftp {Data Type} nscd-configuration
10304 This is the data type representing the name service cache daemon (nscd)
10309 @item @code{name-services} (default: @code{'()})
10310 List of packages denoting @dfn{name services} that must be visible to
10311 the nscd---e.g., @code{(list @var{nss-mdns})}.
10313 @item @code{glibc} (default: @var{glibc})
10314 Package object denoting the GNU C Library providing the @command{nscd}
10317 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
10318 Name of the nscd log file. This is where debugging output goes when
10319 @code{debug-level} is strictly positive.
10321 @item @code{debug-level} (default: @code{0})
10322 Integer denoting the debugging levels. Higher numbers mean that more
10323 debugging output is logged.
10325 @item @code{caches} (default: @var{%nscd-default-caches})
10326 List of @code{<nscd-cache>} objects denoting things to be cached; see
10332 @deftp {Data Type} nscd-cache
10333 Data type representing a cache database of nscd and its parameters.
10337 @item @code{database}
10338 This is a symbol representing the name of the database to be cached.
10339 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
10340 @code{services}, which designate the corresponding NSS database
10341 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
10343 @item @code{positive-time-to-live}
10344 @itemx @code{negative-time-to-live} (default: @code{20})
10345 A number representing the number of seconds during which a positive or
10346 negative lookup result remains in cache.
10348 @item @code{check-files?} (default: @code{#t})
10349 Whether to check for updates of the files corresponding to
10352 For instance, when @var{database} is @code{hosts}, setting this flag
10353 instructs nscd to check for updates in @file{/etc/hosts} and to take
10356 @item @code{persistent?} (default: @code{#t})
10357 Whether the cache should be stored persistently on disk.
10359 @item @code{shared?} (default: @code{#t})
10360 Whether the cache should be shared among users.
10362 @item @code{max-database-size} (default: 32@tie{}MiB)
10363 Maximum size in bytes of the database cache.
10365 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
10366 @c settings, so leave them out.
10371 @defvr {Scheme Variable} %nscd-default-caches
10372 List of @code{<nscd-cache>} objects used by default by
10373 @code{nscd-configuration} (see above).
10375 It enables persistent and aggressive caching of service and host name
10376 lookups. The latter provides better host name lookup performance,
10377 resilience in the face of unreliable name servers, and also better
10378 privacy---often the result of host name lookups is in local cache, so
10379 external name servers do not even need to be queried.
10382 @anchor{syslog-configuration-type}
10385 @deftp {Data Type} syslog-configuration
10386 This data type represents the configuration of the syslog daemon.
10389 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
10390 The syslog daemon to use.
10392 @item @code{config-file} (default: @code{%default-syslog.conf})
10393 The syslog configuration file to use.
10398 @anchor{syslog-service}
10400 @deffn {Scheme Procedure} syslog-service @var{config}
10401 Return a service that runs a syslog daemon according to @var{config}.
10403 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
10404 information on the configuration file syntax.
10407 @anchor{guix-configuration-type}
10408 @deftp {Data Type} guix-configuration
10409 This data type represents the configuration of the Guix build daemon.
10410 @xref{Invoking guix-daemon}, for more information.
10413 @item @code{guix} (default: @var{guix})
10414 The Guix package to use.
10416 @item @code{build-group} (default: @code{"guixbuild"})
10417 Name of the group for build user accounts.
10419 @item @code{build-accounts} (default: @code{10})
10420 Number of build user accounts to create.
10422 @item @code{authorize-key?} (default: @code{#t})
10423 @cindex substitutes, authorization thereof
10424 Whether to authorize the substitute keys listed in
10425 @code{authorized-keys}---by default that of @code{hydra.gnu.org}
10426 (@pxref{Substitutes}).
10428 @vindex %default-authorized-guix-keys
10429 @item @code{authorized-keys} (default: @var{%default-authorized-guix-keys})
10430 The list of authorized key files for archive imports, as a list of
10431 string-valued gexps (@pxref{Invoking guix archive}). By default, it
10432 contains that of @code{hydra.gnu.org} (@pxref{Substitutes}).
10434 @item @code{use-substitutes?} (default: @code{#t})
10435 Whether to use substitutes.
10437 @item @code{substitute-urls} (default: @var{%default-substitute-urls})
10438 The list of URLs where to look for substitutes by default.
10440 @item @code{max-silent-time} (default: @code{0})
10441 @itemx @code{timeout} (default: @code{0})
10442 The number of seconds of silence and the number of seconds of activity,
10443 respectively, after which a build process times out. A value of zero
10444 disables the timeout.
10446 @item @code{log-compression} (default: @code{'bzip2})
10447 The type of compression used for build logs---one of @code{gzip},
10448 @code{bzip2}, or @code{none}.
10450 @item @code{extra-options} (default: @code{'()})
10451 List of extra command-line options for @command{guix-daemon}.
10453 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
10454 File where @command{guix-daemon}'s standard output and standard error
10457 @item @code{http-proxy} (default: @code{#f})
10458 The HTTP proxy used for downloading fixed-output derivations and
10461 @item @code{tmpdir} (default: @code{#f})
10462 A directory path where the @command{guix-daemon} will perform builds.
10467 @deffn {Scheme Procedure} guix-service @var{config}
10468 Return a service that runs the Guix build daemon according to
10472 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
10473 Run @var{udev}, which populates the @file{/dev} directory dynamically.
10474 udev rules can be provided as a list of files through the @var{rules}
10475 variable. The procedures @var{udev-rule} and @var{file->udev-rule} from
10476 @code{(gnu services base)} simplify the creation of such rule files.
10478 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
10479 Return a udev-rule file named @var{file-name} containing the rules
10480 defined by the @var{contents} literal.
10482 In the following example, a rule for a USB device is defined to be
10483 stored in the file @file{90-usb-thing.rules}. The rule runs a script
10484 upon detecting a USB device with a given product identifier.
10487 (define %example-udev-rule
10489 "90-usb-thing.rules"
10490 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
10491 "ATTR@{product@}==\"Example\", "
10492 "RUN+=\"/path/to/script\"")))
10496 Here we show how the default @var{udev-service} can be extended with it.
10502 (modify-services %desktop-services
10503 (udev-service-type config =>
10504 (udev-configuration (inherit config)
10505 (rules (append (udev-configuration-rules config)
10506 (list %example-udev-rule))))))))
10509 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
10510 Return a udev file named @var{file-name} containing the rules defined
10511 within @var{file}, a file-like object.
10513 The following example showcases how we can use an existing rule file.
10516 (use-modules (guix download) ;for url-fetch
10517 (guix packages) ;for origin
10520 (define %android-udev-rules
10522 "51-android-udev.rules"
10523 (let ((version "20170910"))
10526 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
10527 "android-udev-rules/" version "/51-android.rules"))
10529 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
10533 Additionally, Guix package definitions can be included in @var{rules} in
10534 order to extend the udev rules with the definitions found under their
10535 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
10536 @var{file->udev-rule} example, we could have used the
10537 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
10538 packages android)} module.
10540 The following example shows how to use the @var{android-udev-rules}
10541 package so that the Android tool @command{adb} can detect devices
10542 without root privileges. It also details how to create the
10543 @code{adbusers} group, which is required for the proper functioning of
10544 the rules defined within the @var{android-udev-rules} package. To
10545 create such a group, we must define it both as part of the
10546 @var{supplementary-groups} of our @var{user-account} declaration, as
10547 well as in the @var{groups} field of the @var{operating-system} record.
10550 (use-modules (gnu packages android) ;for android-udev-rules
10551 (gnu system shadow) ;for user-group
10556 (users (cons (user-acount
10558 (supplementary-groups
10559 '("adbusers" ;for adb
10560 "wheel" "netdev" "audio" "video"))
10563 (groups (cons (user-group (system? #t) (name "adbusers"))
10569 (modify-services %desktop-services
10570 (udev-service-type config =>
10571 (udev-configuration (inherit config)
10572 (rules (cons* android-udev-rules
10573 (udev-configuration-rules config))))))))
10577 @defvr {Scheme Variable} urandom-seed-service-type
10578 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
10579 when rebooting. It also tries to seed @file{/dev/urandom} from
10580 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
10584 @defvr {Scheme Variable} %random-seed-file
10585 This is the name of the file where some random bytes are saved by
10586 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
10587 It defaults to @file{/var/lib/random-seed}.
10592 @deffn {Scheme Procedure} console-keymap-service @var{files} ...
10593 @cindex keyboard layout
10594 Return a service to load console keymaps from @var{files} using
10595 @command{loadkeys} command. Most likely, you want to load some default
10596 keymap, which can be done like this:
10599 (console-keymap-service "dvorak")
10602 Or, for example, for a Swedish keyboard, you may need to combine
10603 the following keymaps:
10605 (console-keymap-service "se-lat6" "se-fi-lat6")
10608 Also you can specify a full file name (or file names) of your keymap(s).
10609 See @code{man loadkeys} for details.
10615 @defvr {Scheme Variable} gpm-service-type
10616 This is the type of the service that runs GPM, the @dfn{general-purpose
10617 mouse daemon}, which provides mouse support to the Linux console. GPM
10618 allows users to use the mouse in the console, notably to select, copy,
10621 The value for services of this type must be a @code{gpm-configuration}
10622 (see below). This service is not part of @var{%base-services}.
10625 @deftp {Data Type} gpm-configuration
10626 Data type representing the configuration of GPM.
10629 @item @code{options} (default: @code{%default-gpm-options})
10630 Command-line options passed to @command{gpm}. The default set of
10631 options instruct @command{gpm} to listen to mouse events on
10632 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
10635 @item @code{gpm} (default: @code{gpm})
10636 The GPM package to use.
10641 @anchor{guix-publish-service-type}
10642 @deffn {Scheme Variable} guix-publish-service-type
10643 This is the service type for @command{guix publish} (@pxref{Invoking
10644 guix publish}). Its value must be a @code{guix-configuration}
10645 object, as described below.
10647 This assumes that @file{/etc/guix} already contains a signing key pair as
10648 created by @command{guix archive --generate-key} (@pxref{Invoking guix
10649 archive}). If that is not the case, the service will fail to start.
10652 @deftp {Data Type} guix-publish-configuration
10653 Data type representing the configuration of the @code{guix publish}
10657 @item @code{guix} (default: @code{guix})
10658 The Guix package to use.
10660 @item @code{port} (default: @code{80})
10661 The TCP port to listen for connections.
10663 @item @code{host} (default: @code{"localhost"})
10664 The host (and thus, network interface) to listen to. Use
10665 @code{"0.0.0.0"} to listen on all the network interfaces.
10667 @item @code{compression-level} (default: @code{3})
10668 The gzip compression level at which substitutes are compressed. Use
10669 @code{0} to disable compression altogether, and @code{9} to get the best
10670 compression ratio at the expense of increased CPU usage.
10672 @item @code{nar-path} (default: @code{"nar"})
10673 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
10674 publish, @code{--nar-path}}, for details.
10676 @item @code{cache} (default: @code{#f})
10677 When it is @code{#f}, disable caching and instead generate archives on
10678 demand. Otherwise, this should be the name of a directory---e.g.,
10679 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
10680 archives and meta-data ready to be sent. @xref{Invoking guix publish,
10681 @option{--cache}}, for more information on the tradeoffs involved.
10683 @item @code{workers} (default: @code{#f})
10684 When it is an integer, this is the number of worker threads used for
10685 caching; when @code{#f}, the number of processors is used.
10686 @xref{Invoking guix publish, @option{--workers}}, for more information.
10688 @item @code{ttl} (default: @code{#f})
10689 When it is an integer, this denotes the @dfn{time-to-live} in seconds
10690 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
10691 for more information.
10695 @anchor{rngd-service}
10696 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
10697 [#:device "/dev/hwrng"]
10698 Return a service that runs the @command{rngd} program from @var{rng-tools}
10699 to add @var{device} to the kernel's entropy pool. The service will fail if
10700 @var{device} does not exist.
10703 @anchor{pam-limits-service}
10704 @cindex session limits
10709 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
10711 Return a service that installs a configuration file for the
10712 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
10713 @code{pam_limits} module}. The procedure optionally takes a list of
10714 @code{pam-limits-entry} values, which can be used to specify
10715 @code{ulimit} limits and nice priority limits to user sessions.
10717 The following limits definition sets two hard and soft limits for all
10718 login sessions of users in the @code{realtime} group:
10721 (pam-limits-service
10723 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
10724 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
10727 The first entry increases the maximum realtime priority for
10728 non-privileged processes; the second entry lifts any restriction of the
10729 maximum address space that can be locked in memory. These settings are
10730 commonly used for real-time audio systems.
10733 @node Scheduled Job Execution
10734 @subsubsection Scheduled Job Execution
10738 @cindex scheduling jobs
10739 The @code{(gnu services mcron)} module provides an interface to
10740 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
10741 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
10742 Unix @command{cron} daemon; the main difference is that it is
10743 implemented in Guile Scheme, which provides a lot of flexibility when
10744 specifying the scheduling of jobs and their actions.
10746 The example below defines an operating system that runs the
10747 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
10748 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
10749 well as the @command{mkid} command on behalf of an unprivileged user
10750 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
10751 gexps to introduce job definitions that are passed to mcron
10752 (@pxref{G-Expressions}).
10755 (use-modules (guix) (gnu) (gnu services mcron))
10756 (use-package-modules base idutils)
10758 (define updatedb-job
10759 ;; Run 'updatedb' at 3AM every day. Here we write the
10760 ;; job's action as a Scheme procedure.
10761 #~(job '(next-hour '(3))
10763 (execl (string-append #$findutils "/bin/updatedb")
10765 "--prunepaths=/tmp /var/tmp /gnu/store"))))
10767 (define garbage-collector-job
10768 ;; Collect garbage 5 minutes after midnight every day.
10769 ;; The job's action is a shell command.
10770 #~(job "5 0 * * *" ;Vixie cron syntax
10773 (define idutils-job
10774 ;; Update the index database as user "charlie" at 12:15PM
10775 ;; and 19:15PM. This runs from the user's home directory.
10776 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
10777 (string-append #$idutils "/bin/mkid src")
10782 (services (cons (mcron-service (list garbage-collector-job
10788 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
10789 for more information on mcron job specifications. Below is the
10790 reference of the mcron service.
10792 @deffn {Scheme Procedure} mcron-service @var{jobs} [#:mcron @var{mcron}]
10793 Return an mcron service running @var{mcron} that schedules @var{jobs}, a
10794 list of gexps denoting mcron job specifications.
10796 This is a shorthand for:
10798 (service mcron-service-type
10799 (mcron-configuration (mcron mcron) (jobs jobs)))
10803 @defvr {Scheme Variable} mcron-service-type
10804 This is the type of the @code{mcron} service, whose value is an
10805 @code{mcron-configuration} object.
10807 This service type can be the target of a service extension that provides
10808 it additional job specifications (@pxref{Service Composition}). In
10809 other words, it is possible to define services that provide additional
10813 @deftp {Data Type} mcron-configuration
10814 Data type representing the configuration of mcron.
10817 @item @code{mcron} (default: @var{mcron})
10818 The mcron package to use.
10821 This is a list of gexps (@pxref{G-Expressions}), where each gexp
10822 corresponds to an mcron job specification (@pxref{Syntax, mcron job
10823 specifications,, mcron, GNU@tie{}mcron}).
10829 @subsubsection Log Rotation
10832 @cindex log rotation
10834 Log files such as those found in @file{/var/log} tend to grow endlessly,
10835 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
10836 their contents in separate files, possibly compressed. The @code{(gnu
10837 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
10838 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
10840 The example below defines an operating system that provides log rotation
10841 with the default settings, for commonly encountered log files.
10844 (use-modules (guix) (gnu))
10845 (use-service-modules admin mcron)
10846 (use-package-modules base idutils)
10850 (services (cons (service rottlog-service-type)
10854 @defvr {Scheme Variable} rottlog-service-type
10855 This is the type of the Rottlog service, whose value is a
10856 @code{rottlog-configuration} object.
10858 Other services can extend this one with new @code{log-rotation} objects
10859 (see below), thereby augmenting the set of files to be rotated.
10861 This service type can define mcron jobs (@pxref{Scheduled Job
10862 Execution}) to run the rottlog service.
10865 @deftp {Data Type} rottlog-configuration
10866 Data type representing the configuration of rottlog.
10869 @item @code{rottlog} (default: @code{rottlog})
10870 The Rottlog package to use.
10872 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
10873 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
10874 rottlog, GNU Rot[t]log Manual}).
10876 @item @code{rotations} (default: @code{%default-rotations})
10877 A list of @code{log-rotation} objects as defined below.
10880 This is a list of gexps where each gexp corresponds to an mcron job
10881 specification (@pxref{Scheduled Job Execution}).
10885 @deftp {Data Type} log-rotation
10886 Data type representing the rotation of a group of log files.
10888 Taking an example from the Rottlog manual (@pxref{Period Related File
10889 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
10895 (files '("/var/log/apache/*"))
10896 (options '("storedir apache-archives"
10902 The list of fields is as follows:
10905 @item @code{frequency} (default: @code{'weekly})
10906 The log rotation frequency, a symbol.
10909 The list of files or file glob patterns to rotate.
10911 @item @code{options} (default: @code{'()})
10912 The list of rottlog options for this rotation (@pxref{Configuration
10913 parameters,,, rottlog, GNU Rot[t]lg Manual}).
10915 @item @code{post-rotate} (default: @code{#f})
10916 Either @code{#f} or a gexp to execute once the rotation has completed.
10920 @defvr {Scheme Variable} %default-rotations
10921 Specifies weekly rotation of @var{%rotated-files} and
10922 a couple of other files.
10925 @defvr {Scheme Variable} %rotated-files
10926 The list of syslog-controlled files to be rotated. By default it is:
10927 @code{'("/var/log/messages" "/var/log/secure")}.
10930 @node Networking Services
10931 @subsubsection Networking Services
10933 The @code{(gnu services networking)} module provides services to configure
10934 the network interface.
10936 @cindex DHCP, networking service
10937 @deffn {Scheme Procedure} dhcp-client-service [#:dhcp @var{isc-dhcp}]
10938 Return a service that runs @var{dhcp}, a Dynamic Host Configuration
10939 Protocol (DHCP) client, on all the non-loopback network interfaces.
10942 @deffn {Scheme Procedure} dhcpd-service-type
10943 This type defines a service that runs a DHCP daemon. To create a
10944 service of this type, you must supply a @code{<dhcpd-configuration>}.
10948 (service dhcpd-service-type
10949 (dhcpd-configuration
10950 (config-file (local-file "my-dhcpd.conf"))
10951 (interfaces '("enp0s25"))))
10955 @deftp {Data Type} dhcpd-configuration
10957 @item @code{package} (default: @code{isc-dhcp})
10958 The package that provides the DHCP daemon. This package is expected to
10959 provide the daemon at @file{sbin/dhcpd} relative to its output
10960 directory. The default package is the
10961 @uref{http://www.isc.org/products/DHCP, ISC's DHCP server}.
10962 @item @code{config-file} (default: @code{#f})
10963 The configuration file to use. This is required. It will be passed to
10964 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
10965 object (@pxref{G-Expressions, file-like objects}). See @code{man
10966 dhcpd.conf} for details on the configuration file syntax.
10967 @item @code{version} (default: @code{"4"})
10968 The DHCP version to use. The ISC DHCP server supports the values ``4'',
10969 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
10970 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
10972 @item @code{run-directory} (default: @code{"/run/dhcpd"})
10973 The run directory to use. At service activation time, this directory
10974 will be created if it does not exist.
10975 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
10976 The PID file to use. This corresponds to the @code{-pf} option of
10977 @code{dhcpd}. See @code{man dhcpd} for details.
10978 @item @code{interfaces} (default: @code{'()})
10979 The names of the network interfaces on which dhcpd should listen for
10980 broadcasts. If this list is not empty, then its elements (which must be
10981 strings) will be appended to the @code{dhcpd} invocation when starting
10982 the daemon. It may not be necessary to explicitly specify any
10983 interfaces here; see @code{man dhcpd} for details.
10987 @defvr {Scheme Variable} static-networking-service-type
10988 This is the type for statically-configured network interfaces.
10989 @c TODO Document <static-networking> data structures.
10992 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
10993 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}]
10994 [#:requirement @code{'(udev)}]
10995 Return a service that starts @var{interface} with address @var{ip}. If
10996 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
10997 it must be a string specifying the default network gateway. @var{requirement}
10998 can be used to declare a dependency on another service before configuring the
11001 This procedure can be called several times, one for each network
11002 interface of interest. Behind the scenes what it does is extend
11003 @code{static-networking-service-type} with additional network interfaces
11010 @cindex network management
11011 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
11012 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
11013 management daemon that aims to simplify wired and wireless networking.
11015 This service adds the @var{wicd} package to the global profile, providing
11016 several commands to interact with the daemon and configure networking:
11017 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
11018 and @command{wicd-curses} user interfaces.
11021 @cindex ModemManager
11023 @defvr {Scheme Variable} modem-manager-service-type
11024 This is the service type for the
11025 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
11026 service. The value for this service type is a
11027 @code{modem-manager-configuration} record.
11029 This service is part of @code{%desktop-services} (@pxref{Desktop
11033 @deftp {Data Type} modem-manager-configuration
11034 Data type representing the configuration of ModemManager.
11037 @item @code{modem-manager} (default: @code{modem-manager})
11038 The ModemManager package to use.
11043 @cindex NetworkManager
11045 @defvr {Scheme Variable} network-manager-service-type
11046 This is the service type for the
11047 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
11048 service. The value for this service type is a
11049 @code{network-manager-configuration} record.
11051 This service is part of @code{%desktop-services} (@pxref{Desktop
11055 @deftp {Data Type} network-manager-configuration
11056 Data type representing the configuration of NetworkManager.
11059 @item @code{network-manager} (default: @code{network-manager})
11060 The NetworkManager package to use.
11062 @item @code{dns} (default: @code{"default"})
11063 Processing mode for DNS, which affects how NetworkManager uses the
11064 @code{resolv.conf} configuration file.
11068 NetworkManager will update @code{resolv.conf} to reflect the nameservers
11069 provided by currently active connections.
11072 NetworkManager will run @code{dnsmasq} as a local caching nameserver,
11073 using a "split DNS" configuration if you are connected to a VPN, and
11074 then update @code{resolv.conf} to point to the local nameserver.
11077 NetworkManager will not modify @code{resolv.conf}.
11080 @item @code{vpn-plugins} (default: @code{'()})
11081 This is the list of available plugins for virtual private networks
11082 (VPNs). An example of this is the @code{network-manager-openvpn}
11083 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
11089 @deffn {Scheme Variable} connman-service-type
11090 This is the service type to run @url{https://01.org/connman,Connman},
11091 a network connection manager.
11093 Its value must be an
11094 @code{connman-configuration} record as in this example:
11097 (service connman-service-type
11098 (connman-configuration
11099 (disable-vpn? #t)))
11102 See below for details about @code{connman-configuration}.
11105 @deftp {Data Type} connman-configuration
11106 Data Type representing the configuration of connman.
11109 @item @code{connman} (default: @var{connman})
11110 The connman package to use.
11112 @item @code{disable-vpn?} (default: @code{#f})
11113 When true, enable connman's vpn plugin.
11117 @cindex WPA Supplicant
11118 @defvr {Scheme Variable} wpa-supplicant-service-type
11119 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
11120 supplicant}, an authentication daemon required to authenticate against
11121 encrypted WiFi or ethernet networks. It is configured to listen for
11124 The value of this service is the @code{wpa-supplicant} package to use.
11125 Thus, it can be instantiated like this:
11128 (use-modules (gnu services networking))
11130 (service wpa-supplicant-service-type)
11135 @cindex real time clock
11136 @deffn {Scheme Procedure} ntp-service [#:ntp @var{ntp}] @
11137 [#:servers @var{%ntp-servers}] @
11138 [#:allow-large-adjustment? #f]
11139 Return a service that runs the daemon from @var{ntp}, the
11140 @uref{http://www.ntp.org, Network Time Protocol package}. The daemon will
11141 keep the system clock synchronized with that of @var{servers}.
11142 @var{allow-large-adjustment?} determines whether @command{ntpd} is allowed to
11143 make an initial adjustment of more than 1,000 seconds.
11146 @defvr {Scheme Variable} %ntp-servers
11147 List of host names used as the default NTP servers.
11151 @deffn {Scheme Procedure} openntpd-service-type
11152 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
11153 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
11154 clock synchronized with that of the given servers.
11158 openntpd-service-type
11159 (openntpd-configuration
11160 (listen-on '("127.0.0.1" "::1"))
11161 (sensor '("udcf0 correction 70000"))
11162 (constraint-from '("www.gnu.org"))
11163 (constraints-from '("https://www.google.com/"))
11164 (allow-large-adjustment? #t)))
11169 @deftp {Data Type} openntpd-configuration
11171 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
11172 The openntpd executable to use.
11173 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
11174 A list of local IP addresses or hostnames the ntpd daemon should listen on.
11175 @item @code{query-from} (default: @code{'()})
11176 A list of local IP address the ntpd daemon should use for outgoing queries.
11177 @item @code{sensor} (default: @code{'()})
11178 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
11179 will listen to each sensor that acutally exists and ignore non-existant ones.
11180 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
11182 @item @code{server} (default: @var{%ntp-servers})
11183 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
11184 @item @code{servers} (default: @code{'()})
11185 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
11186 @item @code{constraint-from} (default: @code{'()})
11187 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
11188 This time information is not used for precision but acts as an authenticated
11189 constraint, thereby reducing the impact of unauthenticated NTP
11190 man-in-the-middle attacks.
11191 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
11193 @item @code{constraints-from} (default: @code{'()})
11194 As with constraint from, specify a list of URLs, IP addresses or hostnames of
11195 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
11196 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
11197 @item @code{allow-large-adjustment?} (default: @code{#f})
11198 Determines if @code{ntpd} is allowed to make an initial adjustment of more
11204 @deffn {Scheme variable} inetd-service-type
11205 This service runs the @command{inetd} (@pxref{inetd invocation,,,
11206 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
11207 connections on internet sockets, and lazily starts the specified server
11208 program when a connection is made on one of these sockets.
11210 The value of this service is an @code{inetd-configuration} object. The
11211 following example configures the @command{inetd} daemon to provide the
11212 built-in @command{echo} service, as well as an smtp service which
11213 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
11214 gateway @code{hostname}:
11219 (inetd-configuration
11223 (socket-type 'stream)
11230 (socket-type 'stream)
11234 (program (file-append openssh "/bin/ssh"))
11236 '("ssh" "-qT" "-i" "/path/to/ssh_key"
11237 "-W" "smtp-server:25" "user@@hostname")))))
11240 See below for more details about @code{inetd-configuration}.
11243 @deftp {Data Type} inetd-configuration
11244 Data type representing the configuration of @command{inetd}.
11247 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
11248 The @command{inetd} executable to use.
11250 @item @code{entries} (default: @code{'()})
11251 A list of @command{inetd} service entries. Each entry should be created
11252 by the @code{inetd-entry} constructor.
11256 @deftp {Data Type} inetd-entry
11257 Data type representing an entry in the @command{inetd} configuration.
11258 Each entry corresponds to a socket where @command{inetd} will listen for
11262 @item @code{node} (default: @code{#f})
11263 Optional string, a comma-separated list of local addresses
11264 @command{inetd} should use when listening for this service.
11265 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
11266 description of all options.
11268 A string, the name must correspond to an entry in @code{/etc/services}.
11269 @item @code{socket-type}
11270 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
11272 @item @code{protocol}
11273 A string, must correspond to an entry in @code{/etc/protocols}.
11274 @item @code{wait?} (default: @code{#t})
11275 Whether @command{inetd} should wait for the server to exit before
11276 listening to new service requests.
11278 A string containing the user (and, optionally, group) name of the user
11279 as whom the server should run. The group name can be specified in a
11280 suffix, separated by a colon or period, i.e. @code{"user"},
11281 @code{"user:group"} or @code{"user.group"}.
11282 @item @code{program} (default: @code{"internal"})
11283 The server program which will serve the requests, or @code{"internal"}
11284 if @command{inetd} should use a built-in service.
11285 @item @code{arguments} (default: @code{'()})
11286 A list strings or file-like objects, which are the server program's
11287 arguments, starting with the zeroth argument, i.e. the name of the
11288 program itself. For @command{inetd}'s internal services, this entry
11289 must be @code{'()} or @code{'("internal")}.
11292 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
11293 detailed discussion of each configuration field.
11297 @deffn {Scheme Procedure} tor-service [@var{config-file}] [#:tor @var{tor}]
11298 Return a service to run the @uref{https://torproject.org, Tor} anonymous
11301 The daemon runs as the @code{tor} unprivileged user. It is passed
11302 @var{config-file}, a file-like object, with an additional @code{User tor} line
11303 and lines for hidden services added via @code{tor-hidden-service}. Run
11304 @command{man tor} for information about the configuration file.
11307 @cindex hidden service
11308 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
11309 Define a new Tor @dfn{hidden service} called @var{name} and implementing
11310 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
11313 '((22 "127.0.0.1:22")
11314 (80 "127.0.0.1:8080"))
11317 In this example, port 22 of the hidden service is mapped to local port 22, and
11318 port 80 is mapped to local port 8080.
11320 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
11321 the @file{hostname} file contains the @code{.onion} host name for the hidden
11324 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
11325 project's documentation} for more information.
11328 The @code{(gnu services rsync)} module provides the following services:
11330 You might want an rsync daemon if you have files that you want available
11331 so anyone (or just yourself) can download existing files or upload new
11334 @deffn {Scheme Variable} rsync-service-type
11335 This is the type for the @uref{https://rsync.samba.org, rsync} rsync daemon,
11336 @command{rsync-configuration} record as in this example:
11339 (service rsync-service-type)
11342 See below for details about @code{rsync-configuration}.
11345 @deftp {Data Type} rsync-configuration
11346 Data type representing the configuration for @code{rsync-service}.
11349 @item @code{package} (default: @var{rsync})
11350 @code{rsync} package to use.
11352 @item @code{port-number} (default: @code{873})
11353 TCP port on which @command{rsync} listens for incoming connections. If port
11354 is less than @code{1024} @command{rsync} needs to be started as the
11355 @code{root} user and group.
11357 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
11358 Name of the file where @command{rsync} writes its PID.
11360 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
11361 Name of the file where @command{rsync} writes its lock file.
11363 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
11364 Name of the file where @command{rsync} writes its log file.
11366 @item @code{use-chroot?} (default: @var{#t})
11367 Whether to use chroot for @command{rsync} shared directory.
11369 @item @code{share-path} (default: @file{/srv/rsync})
11370 Location of the @command{rsync} shared directory.
11372 @item @code{share-comment} (default: @code{"Rsync share"})
11373 Comment of the @command{rsync} shared directory.
11375 @item @code{read-only?} (default: @var{#f})
11376 Read-write permissions to shared directory.
11378 @item @code{timeout} (default: @code{300})
11379 I/O timeout in seconds.
11381 @item @code{user} (default: @var{"root"})
11382 Owner of the @code{rsync} process.
11384 @item @code{group} (default: @var{"root"})
11385 Group of the @code{rsync} process.
11387 @item @code{uid} (default: @var{"rsyncd"})
11388 User name or user ID that file transfers to and from that module should take
11389 place as when the daemon was run as @code{root}.
11391 @item @code{gid} (default: @var{"rsyncd"})
11392 Group name or group ID that will be used when accessing the module.
11397 Furthermore, @code{(gnu services ssh)} provides the following services.
11401 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
11402 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
11403 [#:allow-empty-passwords? #f] [#:root-login? #f] @
11404 [#:syslog-output? #t] [#:x11-forwarding? #t] @
11405 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
11406 [#:public-key-authentication? #t] [#:initialize? #t]
11407 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
11408 @var{host-key} must designate a file containing the host key, and readable
11411 When @var{daemonic?} is true, @command{lshd} will detach from the
11412 controlling terminal and log its output to syslogd, unless one sets
11413 @var{syslog-output?} to false. Obviously, it also makes lsh-service
11414 depend on existence of syslogd service. When @var{pid-file?} is true,
11415 @command{lshd} writes its PID to the file called @var{pid-file}.
11417 When @var{initialize?} is true, automatically create the seed and host key
11418 upon service activation if they do not exist yet. This may take long and
11419 require interaction.
11421 When @var{initialize?} is false, it is up to the user to initialize the
11422 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
11423 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
11424 basics,,, lsh, LSH Manual}).
11426 When @var{interfaces} is empty, lshd listens for connections on all the
11427 network interfaces; otherwise, @var{interfaces} must be a list of host names
11430 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
11431 passwords, and @var{root-login?} specifies whether to accept log-ins as
11434 The other options should be self-descriptive.
11439 @deffn {Scheme Variable} openssh-service-type
11440 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
11441 shell daemon, @command{sshd}. Its value must be an
11442 @code{openssh-configuration} record as in this example:
11445 (service openssh-service-type
11446 (openssh-configuration
11447 (x11-forwarding? #t)
11448 (permit-root-login 'without-password)
11450 `(("alice" ,(local-file "alice.pub"))
11451 ("bob" ,(local-file "bob.pub"))))))
11454 See below for details about @code{openssh-configuration}.
11456 This service can be extended with extra authorized keys, as in this
11460 (service-extension openssh-service-type
11461 (const `(("charlie"
11462 ,(local-file "charlie.pub")))))
11466 @deftp {Data Type} openssh-configuration
11467 This is the configuration record for OpenSSH's @command{sshd}.
11470 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
11471 Name of the file where @command{sshd} writes its PID.
11473 @item @code{port-number} (default: @code{22})
11474 TCP port on which @command{sshd} listens for incoming connections.
11476 @item @code{permit-root-login} (default: @code{#f})
11477 This field determines whether and when to allow logins as root. If
11478 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
11479 If it's the symbol @code{'without-password}, then root logins are
11480 permitted but not with password-based authentication.
11482 @item @code{allow-empty-passwords?} (default: @code{#f})
11483 When true, users with empty passwords may log in. When false, they may
11486 @item @code{password-authentication?} (default: @code{#t})
11487 When true, users may log in with their password. When false, they have
11488 other authentication methods.
11490 @item @code{public-key-authentication?} (default: @code{#t})
11491 When true, users may log in using public key authentication. When
11492 false, users have to use other authentication method.
11494 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
11495 This is used only by protocol version 2.
11497 @item @code{x11-forwarding?} (default: @code{#f})
11498 When true, forwarding of X11 graphical client connections is
11499 enabled---in other words, @command{ssh} options @option{-X} and
11500 @option{-Y} will work.
11502 @item @code{challenge-response-authentication?} (default: @code{#f})
11503 Specifies whether challenge response authentication is allowed (e.g. via
11506 @item @code{use-pam?} (default: @code{#t})
11507 Enables the Pluggable Authentication Module interface. If set to
11508 @code{#t}, this will enable PAM authentication using
11509 @code{challenge-response-authentication?} and
11510 @code{password-authentication?}, in addition to PAM account and session
11511 module processing for all authentication types.
11513 Because PAM challenge response authentication usually serves an
11514 equivalent role to password authentication, you should disable either
11515 @code{challenge-response-authentication?} or
11516 @code{password-authentication?}.
11518 @item @code{print-last-log?} (default: @code{#t})
11519 Specifies whether @command{sshd} should print the date and time of the
11520 last user login when a user logs in interactively.
11522 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
11523 Configures external subsystems (e.g. file transfer daemon).
11525 This is a list of two-element lists, each of which containing the
11526 subsystem name and a command (with optional arguments) to execute upon
11529 The command @command{internal-sftp} implements an in-process SFTP
11530 server. Alternately, one can specify the @command{sftp-server} command:
11532 (service openssh-service-type
11533 (openssh-configuration
11535 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
11538 @item @code{accepted-environment} (default: @code{'()})
11539 List of strings describing which environment variables may be exported.
11541 Each string gets on its own line. See the @code{AcceptEnv} option in
11542 @code{man sshd_config}.
11544 This example allows ssh-clients to export the @code{COLORTERM} variable.
11545 It is set by terminal emulators, which support colors. You can use it in
11546 your shell's ressource file to enable colors for the prompt and commands
11547 if this variable is set.
11550 (service openssh-service-type
11551 (openssh-configuration
11552 (accepted-environment '("COLORTERM"))))
11555 @item @code{authorized-keys} (default: @code{'()})
11556 @cindex authorized keys, SSH
11557 @cindex SSH authorized keys
11558 This is the list of authorized keys. Each element of the list is a user
11559 name followed by one or more file-like objects that represent SSH public
11563 (openssh-configuration
11565 `(("rekado" ,(local-file "rekado.pub"))
11566 ("chris" ,(local-file "chris.pub"))
11567 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
11571 registers the specified public keys for user accounts @code{rekado},
11572 @code{chris}, and @code{root}.
11574 Additional authorized keys can be specified @i{via}
11575 @code{service-extension}.
11577 Note that this does @emph{not} interfere with the use of
11578 @file{~/.ssh/authorized_keys}.
11582 @deffn {Scheme Procedure} dropbear-service [@var{config}]
11583 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
11584 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
11587 For example, to specify a Dropbear service listening on port 1234, add
11588 this call to the operating system's @code{services} field:
11591 (dropbear-service (dropbear-configuration
11592 (port-number 1234)))
11596 @deftp {Data Type} dropbear-configuration
11597 This data type represents the configuration of a Dropbear SSH daemon.
11600 @item @code{dropbear} (default: @var{dropbear})
11601 The Dropbear package to use.
11603 @item @code{port-number} (default: 22)
11604 The TCP port where the daemon waits for incoming connections.
11606 @item @code{syslog-output?} (default: @code{#t})
11607 Whether to enable syslog output.
11609 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
11610 File name of the daemon's PID file.
11612 @item @code{root-login?} (default: @code{#f})
11613 Whether to allow @code{root} logins.
11615 @item @code{allow-empty-passwords?} (default: @code{#f})
11616 Whether to allow empty passwords.
11618 @item @code{password-authentication?} (default: @code{#t})
11619 Whether to enable password-based authentication.
11623 @defvr {Scheme Variable} %facebook-host-aliases
11624 This variable contains a string for use in @file{/etc/hosts}
11625 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
11626 line contains a entry that maps a known server name of the Facebook
11627 on-line service---e.g., @code{www.facebook.com}---to the local
11628 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
11630 This variable is typically used in the @code{hosts-file} field of an
11631 @code{operating-system} declaration (@pxref{operating-system Reference,
11632 @file{/etc/hosts}}):
11635 (use-modules (gnu) (guix))
11638 (host-name "mymachine")
11641 ;; Create a /etc/hosts file with aliases for "localhost"
11642 ;; and "mymachine", as well as for Facebook servers.
11643 (plain-file "hosts"
11644 (string-append (local-host-aliases host-name)
11645 %facebook-host-aliases))))
11648 This mechanism can prevent programs running locally, such as Web
11649 browsers, from accessing Facebook.
11652 The @code{(gnu services avahi)} provides the following definition.
11654 @deffn {Scheme Procedure} avahi-service [#:avahi @var{avahi}] @
11655 [#:host-name #f] [#:publish? #t] [#:ipv4? #t] @
11656 [#:ipv6? #t] [#:wide-area? #f] @
11657 [#:domains-to-browse '()] [#:debug? #f]
11658 Return a service that runs @command{avahi-daemon}, a system-wide
11659 mDNS/DNS-SD responder that allows for service discovery and
11660 "zero-configuration" host name lookups (see @uref{http://avahi.org/}), and
11661 extends the name service cache daemon (nscd) so that it can resolve
11662 @code{.local} host names using
11663 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. Additionally,
11664 add the @var{avahi} package to the system profile so that commands such as
11665 @command{avahi-browse} are directly usable.
11667 If @var{host-name} is different from @code{#f}, use that as the host name to
11668 publish for this machine; otherwise, use the machine's actual host name.
11670 When @var{publish?} is true, publishing of host names and services is allowed;
11671 in particular, avahi-daemon will publish the machine's host name and IP
11672 address via mDNS on the local network.
11674 When @var{wide-area?} is true, DNS-SD over unicast DNS is enabled.
11676 Boolean values @var{ipv4?} and @var{ipv6?} determine whether to use IPv4/IPv6
11680 @deffn {Scheme Variable} openvswitch-service-type
11681 This is the type of the @uref{http://www.openvswitch.org, Open vSwitch}
11682 service, whose value should be an @code{openvswitch-configuration}
11686 @deftp {Data Type} openvswitch-configuration
11687 Data type representing the configuration of Open vSwitch, a multilayer
11688 virtual switch which is designed to enable massive network automation
11689 through programmatic extension.
11692 @item @code{package} (default: @var{openvswitch})
11693 Package object of the Open vSwitch.
11699 @subsubsection X Window
11702 @cindex X Window System
11703 @cindex login manager
11704 Support for the X Window graphical display system---specifically
11705 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
11706 there is no @code{xorg-service} procedure. Instead, the X server is
11707 started by the @dfn{login manager}, by default SLiM.
11709 @cindex window manager
11710 To use X11, you must install at least one @dfn{window manager}---for
11711 example the @code{windowmaker} or @code{openbox} packages---preferably
11712 by adding it to the @code{packages} field of your operating system
11713 definition (@pxref{operating-system Reference, system-wide packages}).
11715 @defvr {Scheme Variable} slim-service-type
11716 This is the type for the SLiM graphical login manager for X11.
11718 @cindex session types (X11)
11719 @cindex X11 session types
11720 SLiM looks for @dfn{session types} described by the @file{.desktop} files in
11721 @file{/run/current-system/profile/share/xsessions} and allows users to
11722 choose a session from the log-in screen using @kbd{F1}. Packages such
11723 as @code{xfce}, @code{sawfish}, and @code{ratpoison} provide
11724 @file{.desktop} files; adding them to the system-wide set of packages
11725 automatically makes them available at the log-in screen.
11727 In addition, @file{~/.xsession} files are honored. When available,
11728 @file{~/.xsession} must be an executable that starts a window manager
11729 and/or other X clients.
11732 @deftp {Data Type} slim-configuration
11733 Data type representing the configuration of @code{slim-service-type}.
11736 @item @code{allow-empty-passwords?} (default: @code{#t})
11737 Whether to allow logins with empty passwords.
11739 @item @code{auto-login?} (default: @code{#f})
11740 @itemx @code{default-user} (default: @code{""})
11741 When @code{auto-login?} is false, SLiM presents a log-in screen.
11743 When @code{auto-login?} is true, SLiM logs in directly as
11744 @code{default-user}.
11746 @item @code{theme} (default: @code{%default-slim-theme})
11747 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
11748 The graphical theme to use and its name.
11750 @item @code{auto-login-session} (default: @code{#f})
11751 If true, this must be the name of the executable to start as the default
11752 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
11754 If false, a session described by one of the available @file{.desktop}
11755 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
11759 You must install at least one window manager in the system profile or in
11760 your user profile. Failing to do that, if @code{auto-login-session} is
11761 false, you will be unable to log in.
11764 @item @code{startx} (default: @code{(xorg-start-command)})
11765 The command used to start the X11 graphical server.
11767 @item @code{xauth} (default: @code{xauth})
11768 The XAuth package to use.
11770 @item @code{shepherd} (default: @code{shepherd})
11771 The Shepherd package used when invoking @command{halt} and
11774 @item @code{sessreg} (default: @code{sessreg})
11775 The sessreg package used in order to register the session.
11777 @item @code{slim} (default: @code{slim})
11778 The SLiM package to use.
11782 @defvr {Scheme Variable} %default-theme
11783 @defvrx {Scheme Variable} %default-theme-name
11784 The default SLiM theme and its name.
11788 @deftp {Data Type} sddm-configuration
11789 This is the data type representing the sddm service configuration.
11792 @item @code{display-server} (default: "x11")
11793 Select display server to use for the greeter. Valid values are "x11"
11796 @item @code{numlock} (default: "on")
11797 Valid values are "on", "off" or "none".
11799 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
11800 Command to run when halting.
11802 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
11803 Command to run when rebooting.
11805 @item @code{theme} (default "maldives")
11806 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
11808 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
11809 Directory to look for themes.
11811 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
11812 Directory to look for faces.
11814 @item @code{default-path} (default "/run/current-system/profile/bin")
11815 Default PATH to use.
11817 @item @code{minimum-uid} (default 1000)
11818 Minimum UID to display in SDDM.
11820 @item @code{maximum-uid} (default 2000)
11821 Maximum UID to display in SDDM
11823 @item @code{remember-last-user?} (default #t)
11824 Remember last user.
11826 @item @code{remember-last-session?} (default #t)
11827 Remember last session.
11829 @item @code{hide-users} (default "")
11830 Usernames to hide from SDDM greeter.
11832 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
11833 Users with shells listed will be hidden from the SDDM greeter.
11835 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
11836 Script to run before starting a wayland session.
11838 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
11839 Directory to look for desktop files starting wayland sessions.
11841 @item @code{xorg-server-path} (default @code{xorg-start-command})
11842 Path to xorg-server.
11844 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
11847 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
11850 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
11851 Script to run after starting xorg-server.
11853 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
11854 Script to run before stopping xorg-server.
11856 @item @code{xsession-command} (default: @code{xinitrc})
11857 Script to run before starting a X session.
11859 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
11860 Directory to look for desktop files starting X sessions.
11862 @item @code{minimum-vt} (default: 7)
11865 @item @code{xserver-arguments} (default "-nolisten tcp")
11866 Arguments to pass to xorg-server.
11868 @item @code{auto-login-user} (default "")
11869 User to use for auto-login.
11871 @item @code{auto-login-session} (default "")
11872 Desktop file to use for auto-login.
11874 @item @code{relogin?} (default #f)
11875 Relogin after logout.
11880 @cindex login manager
11882 @deffn {Scheme Procedure} sddm-service config
11883 Return a service that spawns the SDDM graphical login manager for config of
11884 type @code{<sddm-configuration>}.
11887 (sddm-service (sddm-configuration
11888 (auto-login-user "Alice")
11889 (auto-login-session "xfce.desktop")))
11893 @deffn {Scheme Procedure} xorg-start-command [#:guile] @
11894 [#:modules %default-xorg-modules] @
11895 [#:fonts %default-xorg-fonts] @
11896 [#:configuration-file (xorg-configuration-file @dots{})] @
11897 [#:xorg-server @var{xorg-server}]
11898 Return a @code{startx} script in which @var{modules}, a list of X module
11899 packages, and @var{fonts}, a list of X font directories, are available. See
11900 @code{xorg-wrapper} for more details on the arguments. The result should be
11901 used in place of @code{startx}.
11903 Usually the X server is started by a login manager.
11906 @deffn {Scheme Procedure} xorg-configuration-file @
11907 [#:modules %default-xorg-modules] @
11908 [#:fonts %default-xorg-fonts] @
11909 [#:drivers '()] [#:resolutions '()] [#:extra-config '()]
11910 Return a configuration file for the Xorg server containing search paths for
11911 all the common drivers.
11913 @var{modules} must be a list of @dfn{module packages} loaded by the Xorg
11914 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
11915 @var{fonts} must be a list of font directories to add to the server's
11918 @var{drivers} must be either the empty list, in which case Xorg chooses a
11919 graphics driver automatically, or a list of driver names that will be tried in
11920 this order---e.g., @code{("modesetting" "vesa")}.
11922 Likewise, when @var{resolutions} is the empty list, Xorg chooses an
11923 appropriate screen resolution; otherwise, it must be a list of
11924 resolutions---e.g., @code{((1024 768) (640 480))}.
11926 Last, @var{extra-config} is a list of strings or objects appended to the
11927 configuration file. It is used to pass extra text to be
11928 added verbatim to the configuration file.
11931 @cindex keyboard layout
11932 This procedure is especially useful to configure a different keyboard layout
11933 than the default US keymap. For instance, to use the ``bépo'' keymap by
11934 default on the display manager:
11938 "Section \"InputClass\"
11939 Identifier \"evdev keyboard catchall\"
11941 MatchIsKeyboard \"on\"
11942 Option \"xkb_layout\" \"fr\"
11943 Option \"xkb_variant\" \"bepo\"
11949 (modify-services %desktop-services
11950 (slim-service-type config =>
11951 (slim-configuration
11953 (startx (xorg-start-command
11954 #:configuration-file
11955 (xorg-configuration-file
11957 (list bepo-evdev)))))))))
11960 The @code{MatchIsKeyboard} line specifies that we only apply the configuration
11961 to keyboards. Without this line, other devices such as touchpad may not work
11962 correctly because they will be attached to the wrong driver. In this example,
11963 the user typically used @code{setxkbmap fr bepo} to set their favorite keymap
11964 once logged in. The first argument corresponds to the layout, while the second
11965 argument corresponds to the variant. The @code{xkb_variant} line can be omitted
11966 to select the default variant.
11969 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
11970 Add @var{package}, a package for a screen locker or screen saver whose
11971 command is @var{program}, to the set of setuid programs and add a PAM entry
11972 for it. For example:
11975 (screen-locker-service xlockmore "xlock")
11978 makes the good ol' XlockMore usable.
11982 @node Printing Services
11983 @subsubsection Printing Services
11985 @cindex printer support with CUPS
11986 The @code{(gnu services cups)} module provides a Guix service definition
11987 for the CUPS printing service. To add printer support to a GuixSD
11988 system, add a @code{cups-service} to the operating system definition:
11990 @deffn {Scheme Variable} cups-service-type
11991 The service type for the CUPS print server. Its value should be a valid
11992 CUPS configuration (see below). To use the default settings, simply
11995 (service cups-service-type)
11999 The CUPS configuration controls the basic things about your CUPS
12000 installation: what interfaces it listens on, what to do if a print job
12001 fails, how much logging to do, and so on. To actually add a printer,
12002 you have to visit the @url{http://localhost:631} URL, or use a tool such
12003 as GNOME's printer configuration services. By default, configuring a
12004 CUPS service will generate a self-signed certificate if needed, for
12005 secure connections to the print server.
12007 Suppose you want to enable the Web interface of CUPS and also add
12008 support for Epson printers @i{via} the @code{escpr} package and for HP
12009 printers @i{via} the @code{hplip} package. You can do that directly,
12010 like this (you need to use the @code{(gnu packages cups)} module):
12013 (service cups-service-type
12014 (cups-configuration
12015 (web-interface? #t)
12017 (list cups-filters escpr hplip))))
12020 The available configuration parameters follow. Each parameter
12021 definition is preceded by its type; for example, @samp{string-list foo}
12022 indicates that the @code{foo} parameter should be specified as a list of
12023 strings. There is also a way to specify the configuration as a string,
12024 if you have an old @code{cupsd.conf} file that you want to port over
12025 from some other system; see the end for more details.
12027 @c The following documentation was initially generated by
12028 @c (generate-documentation) in (gnu services cups). Manually maintained
12029 @c documentation is better, so we shouldn't hesitate to edit below as
12030 @c needed. However if the change you want to make to this documentation
12031 @c can be done in an automated way, it's probably easier to change
12032 @c (generate-documentation) than to make it below and have to deal with
12033 @c the churn as CUPS updates.
12036 Available @code{cups-configuration} fields are:
12038 @deftypevr {@code{cups-configuration} parameter} package cups
12042 @deftypevr {@code{cups-configuration} parameter} package-list extensions
12043 Drivers and other extensions to the CUPS package.
12046 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
12047 Configuration of where to write logs, what directories to use for print
12048 spools, and related privileged configuration parameters.
12050 Available @code{files-configuration} fields are:
12052 @deftypevr {@code{files-configuration} parameter} log-location access-log
12053 Defines the access log filename. Specifying a blank filename disables
12054 access log generation. The value @code{stderr} causes log entries to be
12055 sent to the standard error file when the scheduler is running in the
12056 foreground, or to the system log daemon when run in the background. The
12057 value @code{syslog} causes log entries to be sent to the system log
12058 daemon. The server name may be included in filenames using the string
12059 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
12061 Defaults to @samp{"/var/log/cups/access_log"}.
12064 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
12065 Where CUPS should cache data.
12067 Defaults to @samp{"/var/cache/cups"}.
12070 @deftypevr {@code{files-configuration} parameter} string config-file-perm
12071 Specifies the permissions for all configuration files that the scheduler
12074 Note that the permissions for the printers.conf file are currently
12075 masked to only allow access from the scheduler user (typically root).
12076 This is done because printer device URIs sometimes contain sensitive
12077 authentication information that should not be generally known on the
12078 system. There is no way to disable this security feature.
12080 Defaults to @samp{"0640"}.
12083 @deftypevr {@code{files-configuration} parameter} log-location error-log
12084 Defines the error log filename. Specifying a blank filename disables
12085 access log generation. The value @code{stderr} causes log entries to be
12086 sent to the standard error file when the scheduler is running in the
12087 foreground, or to the system log daemon when run in the background. The
12088 value @code{syslog} causes log entries to be sent to the system log
12089 daemon. The server name may be included in filenames using the string
12090 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
12092 Defaults to @samp{"/var/log/cups/error_log"}.
12095 @deftypevr {@code{files-configuration} parameter} string fatal-errors
12096 Specifies which errors are fatal, causing the scheduler to exit. The
12101 No errors are fatal.
12104 All of the errors below are fatal.
12107 Browsing initialization errors are fatal, for example failed connections
12108 to the DNS-SD daemon.
12111 Configuration file syntax errors are fatal.
12114 Listen or Port errors are fatal, except for IPv6 failures on the
12115 loopback or @code{any} addresses.
12118 Log file creation or write errors are fatal.
12121 Bad startup file permissions are fatal, for example shared TLS
12122 certificate and key files with world-read permissions.
12125 Defaults to @samp{"all -browse"}.
12128 @deftypevr {@code{files-configuration} parameter} boolean file-device?
12129 Specifies whether the file pseudo-device can be used for new printer
12130 queues. The URI @uref{file:///dev/null} is always allowed.
12132 Defaults to @samp{#f}.
12135 @deftypevr {@code{files-configuration} parameter} string group
12136 Specifies the group name or ID that will be used when executing external
12139 Defaults to @samp{"lp"}.
12142 @deftypevr {@code{files-configuration} parameter} string log-file-perm
12143 Specifies the permissions for all log files that the scheduler writes.
12145 Defaults to @samp{"0644"}.
12148 @deftypevr {@code{files-configuration} parameter} log-location page-log
12149 Defines the page log filename. Specifying a blank filename disables
12150 access log generation. The value @code{stderr} causes log entries to be
12151 sent to the standard error file when the scheduler is running in the
12152 foreground, or to the system log daemon when run in the background. The
12153 value @code{syslog} causes log entries to be sent to the system log
12154 daemon. The server name may be included in filenames using the string
12155 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
12157 Defaults to @samp{"/var/log/cups/page_log"}.
12160 @deftypevr {@code{files-configuration} parameter} string remote-root
12161 Specifies the username that is associated with unauthenticated accesses
12162 by clients claiming to be the root user. The default is @code{remroot}.
12164 Defaults to @samp{"remroot"}.
12167 @deftypevr {@code{files-configuration} parameter} file-name request-root
12168 Specifies the directory that contains print jobs and other HTTP request
12171 Defaults to @samp{"/var/spool/cups"}.
12174 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
12175 Specifies the level of security sandboxing that is applied to print
12176 filters, backends, and other child processes of the scheduler; either
12177 @code{relaxed} or @code{strict}. This directive is currently only
12178 used/supported on macOS.
12180 Defaults to @samp{strict}.
12183 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
12184 Specifies the location of TLS certificates and private keys. CUPS will
12185 look for public and private keys in this directory: a @code{.crt} files
12186 for PEM-encoded certificates and corresponding @code{.key} files for
12187 PEM-encoded private keys.
12189 Defaults to @samp{"/etc/cups/ssl"}.
12192 @deftypevr {@code{files-configuration} parameter} file-name server-root
12193 Specifies the directory containing the server configuration files.
12195 Defaults to @samp{"/etc/cups"}.
12198 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
12199 Specifies whether the scheduler calls fsync(2) after writing
12200 configuration or state files.
12202 Defaults to @samp{#f}.
12205 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
12206 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
12209 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
12210 Specifies the directory where temporary files are stored.
12212 Defaults to @samp{"/var/spool/cups/tmp"}.
12215 @deftypevr {@code{files-configuration} parameter} string user
12216 Specifies the user name or ID that is used when running external
12219 Defaults to @samp{"lp"}.
12223 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
12224 Specifies the logging level for the AccessLog file. The @code{config}
12225 level logs when printers and classes are added, deleted, or modified and
12226 when configuration files are accessed or updated. The @code{actions}
12227 level logs when print jobs are submitted, held, released, modified, or
12228 canceled, and any of the conditions for @code{config}. The @code{all}
12229 level logs all requests.
12231 Defaults to @samp{actions}.
12234 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
12235 Specifies whether to purge job history data automatically when it is no
12236 longer required for quotas.
12238 Defaults to @samp{#f}.
12241 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
12242 Specifies which protocols to use for local printer sharing.
12244 Defaults to @samp{dnssd}.
12247 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
12248 Specifies whether the CUPS web interface is advertised.
12250 Defaults to @samp{#f}.
12253 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
12254 Specifies whether shared printers are advertised.
12256 Defaults to @samp{#f}.
12259 @deftypevr {@code{cups-configuration} parameter} string classification
12260 Specifies the security classification of the server. Any valid banner
12261 name can be used, including "classified", "confidential", "secret",
12262 "topsecret", and "unclassified", or the banner can be omitted to disable
12263 secure printing functions.
12265 Defaults to @samp{""}.
12268 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
12269 Specifies whether users may override the classification (cover page) of
12270 individual print jobs using the @code{job-sheets} option.
12272 Defaults to @samp{#f}.
12275 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
12276 Specifies the default type of authentication to use.
12278 Defaults to @samp{Basic}.
12281 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
12282 Specifies whether encryption will be used for authenticated requests.
12284 Defaults to @samp{Required}.
12287 @deftypevr {@code{cups-configuration} parameter} string default-language
12288 Specifies the default language to use for text and web content.
12290 Defaults to @samp{"en"}.
12293 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
12294 Specifies the default paper size for new print queues. @samp{"Auto"}
12295 uses a locale-specific default, while @samp{"None"} specifies there is
12296 no default paper size. Specific size names are typically
12297 @samp{"Letter"} or @samp{"A4"}.
12299 Defaults to @samp{"Auto"}.
12302 @deftypevr {@code{cups-configuration} parameter} string default-policy
12303 Specifies the default access policy to use.
12305 Defaults to @samp{"default"}.
12308 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
12309 Specifies whether local printers are shared by default.
12311 Defaults to @samp{#t}.
12314 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
12315 Specifies the delay for updating of configuration and state files, in
12316 seconds. A value of 0 causes the update to happen as soon as possible,
12317 typically within a few milliseconds.
12319 Defaults to @samp{30}.
12322 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
12323 Specifies what to do when an error occurs. Possible values are
12324 @code{abort-job}, which will discard the failed print job;
12325 @code{retry-job}, which will retry the job at a later time;
12326 @code{retry-this-job}, which retries the failed job immediately; and
12327 @code{stop-printer}, which stops the printer.
12329 Defaults to @samp{stop-printer}.
12332 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
12333 Specifies the maximum cost of filters that are run concurrently, which
12334 can be used to minimize disk, memory, and CPU resource problems. A
12335 limit of 0 disables filter limiting. An average print to a
12336 non-PostScript printer needs a filter limit of about 200. A PostScript
12337 printer needs about half that (100). Setting the limit below these
12338 thresholds will effectively limit the scheduler to printing a single job
12341 Defaults to @samp{0}.
12344 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
12345 Specifies the scheduling priority of filters that are run to print a
12346 job. The nice value ranges from 0, the highest priority, to 19, the
12349 Defaults to @samp{0}.
12352 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
12353 Specifies whether to do reverse lookups on connecting clients. The
12354 @code{double} setting causes @code{cupsd} to verify that the hostname
12355 resolved from the address matches one of the addresses returned for that
12356 hostname. Double lookups also prevent clients with unregistered
12357 addresses from connecting to your server. Only set this option to
12358 @code{#t} or @code{double} if absolutely required.
12360 Defaults to @samp{#f}.
12363 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
12364 Specifies the number of seconds to wait before killing the filters and
12365 backend associated with a canceled or held job.
12367 Defaults to @samp{30}.
12370 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
12371 Specifies the interval between retries of jobs in seconds. This is
12372 typically used for fax queues but can also be used with normal print
12373 queues whose error policy is @code{retry-job} or
12374 @code{retry-current-job}.
12376 Defaults to @samp{30}.
12379 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
12380 Specifies the number of retries that are done for jobs. This is
12381 typically used for fax queues but can also be used with normal print
12382 queues whose error policy is @code{retry-job} or
12383 @code{retry-current-job}.
12385 Defaults to @samp{5}.
12388 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
12389 Specifies whether to support HTTP keep-alive connections.
12391 Defaults to @samp{#t}.
12394 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
12395 Specifies how long an idle client connection remains open, in seconds.
12397 Defaults to @samp{30}.
12400 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
12401 Specifies the maximum size of print files, IPP requests, and HTML form
12402 data. A limit of 0 disables the limit check.
12404 Defaults to @samp{0}.
12407 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
12408 Listens on the specified interfaces for connections. Valid values are
12409 of the form @var{address}:@var{port}, where @var{address} is either an
12410 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
12411 indicate all addresses. Values can also be file names of local UNIX
12412 domain sockets. The Listen directive is similar to the Port directive
12413 but allows you to restrict access to specific interfaces or networks.
12416 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
12417 Specifies the number of pending connections that will be allowed. This
12418 normally only affects very busy servers that have reached the MaxClients
12419 limit, but can also be triggered by large numbers of simultaneous
12420 connections. When the limit is reached, the operating system will
12421 refuse additional connections until the scheduler can accept the pending
12424 Defaults to @samp{128}.
12427 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
12428 Specifies a set of additional access controls.
12430 Available @code{location-access-controls} fields are:
12432 @deftypevr {@code{location-access-controls} parameter} file-name path
12433 Specifies the URI path to which the access control applies.
12436 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
12437 Access controls for all access to this path, in the same format as the
12438 @code{access-controls} of @code{operation-access-control}.
12440 Defaults to @samp{()}.
12443 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
12444 Access controls for method-specific access to this path.
12446 Defaults to @samp{()}.
12448 Available @code{method-access-controls} fields are:
12450 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
12451 If @code{#t}, apply access controls to all methods except the listed
12452 methods. Otherwise apply to only the listed methods.
12454 Defaults to @samp{#f}.
12457 @deftypevr {@code{method-access-controls} parameter} method-list methods
12458 Methods to which this access control applies.
12460 Defaults to @samp{()}.
12463 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
12464 Access control directives, as a list of strings. Each string should be
12465 one directive, such as "Order allow,deny".
12467 Defaults to @samp{()}.
12472 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
12473 Specifies the number of debugging messages that are retained for logging
12474 if an error occurs in a print job. Debug messages are logged regardless
12475 of the LogLevel setting.
12477 Defaults to @samp{100}.
12480 @deftypevr {@code{cups-configuration} parameter} log-level log-level
12481 Specifies the level of logging for the ErrorLog file. The value
12482 @code{none} stops all logging while @code{debug2} logs everything.
12484 Defaults to @samp{info}.
12487 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
12488 Specifies the format of the date and time in the log files. The value
12489 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
12491 Defaults to @samp{standard}.
12494 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
12495 Specifies the maximum number of simultaneous clients that are allowed by
12498 Defaults to @samp{100}.
12501 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
12502 Specifies the maximum number of simultaneous clients that are allowed
12503 from a single address.
12505 Defaults to @samp{100}.
12508 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
12509 Specifies the maximum number of copies that a user can print of each
12512 Defaults to @samp{9999}.
12515 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
12516 Specifies the maximum time a job may remain in the @code{indefinite}
12517 hold state before it is canceled. A value of 0 disables cancellation of
12520 Defaults to @samp{0}.
12523 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
12524 Specifies the maximum number of simultaneous jobs that are allowed. Set
12525 to 0 to allow an unlimited number of jobs.
12527 Defaults to @samp{500}.
12530 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
12531 Specifies the maximum number of simultaneous jobs that are allowed per
12532 printer. A value of 0 allows up to MaxJobs jobs per printer.
12534 Defaults to @samp{0}.
12537 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
12538 Specifies the maximum number of simultaneous jobs that are allowed per
12539 user. A value of 0 allows up to MaxJobs jobs per user.
12541 Defaults to @samp{0}.
12544 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
12545 Specifies the maximum time a job may take to print before it is
12546 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
12548 Defaults to @samp{10800}.
12551 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
12552 Specifies the maximum size of the log files before they are rotated, in
12553 bytes. The value 0 disables log rotation.
12555 Defaults to @samp{1048576}.
12558 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
12559 Specifies the maximum amount of time to allow between files in a
12560 multiple file print job, in seconds.
12562 Defaults to @samp{300}.
12565 @deftypevr {@code{cups-configuration} parameter} string page-log-format
12566 Specifies the format of PageLog lines. Sequences beginning with percent
12567 (@samp{%}) characters are replaced with the corresponding information,
12568 while all other characters are copied literally. The following percent
12569 sequences are recognized:
12573 insert a single percent character
12576 insert the value of the specified IPP attribute
12579 insert the number of copies for the current page
12582 insert the current page number
12585 insert the current date and time in common log format
12591 insert the printer name
12594 insert the username
12597 A value of the empty string disables page logging. The string @code{%p
12598 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
12599 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
12602 Defaults to @samp{""}.
12605 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
12606 Passes the specified environment variable(s) to child processes; a list
12609 Defaults to @samp{()}.
12612 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
12613 Specifies named access control policies.
12615 Available @code{policy-configuration} fields are:
12617 @deftypevr {@code{policy-configuration} parameter} string name
12618 Name of the policy.
12621 @deftypevr {@code{policy-configuration} parameter} string job-private-access
12622 Specifies an access list for a job's private values. @code{@@ACL} maps
12623 to the printer's requesting-user-name-allowed or
12624 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
12625 owner. @code{@@SYSTEM} maps to the groups listed for the
12626 @code{system-group} field of the @code{files-config} configuration,
12627 which is reified into the @code{cups-files.conf(5)} file. Other
12628 possible elements of the access list include specific user names, and
12629 @code{@@@var{group}} to indicate members of a specific group. The
12630 access list may also be simply @code{all} or @code{default}.
12632 Defaults to @samp{"@@OWNER @@SYSTEM"}.
12635 @deftypevr {@code{policy-configuration} parameter} string job-private-values
12636 Specifies the list of job values to make private, or @code{all},
12637 @code{default}, or @code{none}.
12639 Defaults to @samp{"job-name job-originating-host-name
12640 job-originating-user-name phone"}.
12643 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
12644 Specifies an access list for a subscription's private values.
12645 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
12646 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
12647 owner. @code{@@SYSTEM} maps to the groups listed for the
12648 @code{system-group} field of the @code{files-config} configuration,
12649 which is reified into the @code{cups-files.conf(5)} file. Other
12650 possible elements of the access list include specific user names, and
12651 @code{@@@var{group}} to indicate members of a specific group. The
12652 access list may also be simply @code{all} or @code{default}.
12654 Defaults to @samp{"@@OWNER @@SYSTEM"}.
12657 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
12658 Specifies the list of job values to make private, or @code{all},
12659 @code{default}, or @code{none}.
12661 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
12662 notify-subscriber-user-name notify-user-data"}.
12665 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
12666 Access control by IPP operation.
12668 Defaults to @samp{()}.
12672 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
12673 Specifies whether job files (documents) are preserved after a job is
12674 printed. If a numeric value is specified, job files are preserved for
12675 the indicated number of seconds after printing. Otherwise a boolean
12676 value applies indefinitely.
12678 Defaults to @samp{86400}.
12681 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
12682 Specifies whether the job history is preserved after a job is printed.
12683 If a numeric value is specified, the job history is preserved for the
12684 indicated number of seconds after printing. If @code{#t}, the job
12685 history is preserved until the MaxJobs limit is reached.
12687 Defaults to @samp{#t}.
12690 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
12691 Specifies the amount of time to wait for job completion before
12692 restarting the scheduler.
12694 Defaults to @samp{30}.
12697 @deftypevr {@code{cups-configuration} parameter} string rip-cache
12698 Specifies the maximum amount of memory to use when converting documents
12699 into bitmaps for a printer.
12701 Defaults to @samp{"128m"}.
12704 @deftypevr {@code{cups-configuration} parameter} string server-admin
12705 Specifies the email address of the server administrator.
12707 Defaults to @samp{"root@@localhost.localdomain"}.
12710 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
12711 The ServerAlias directive is used for HTTP Host header validation when
12712 clients connect to the scheduler from external interfaces. Using the
12713 special name @code{*} can expose your system to known browser-based DNS
12714 rebinding attacks, even when accessing sites through a firewall. If the
12715 auto-discovery of alternate names does not work, we recommend listing
12716 each alternate name with a ServerAlias directive instead of using
12719 Defaults to @samp{*}.
12722 @deftypevr {@code{cups-configuration} parameter} string server-name
12723 Specifies the fully-qualified host name of the server.
12725 Defaults to @samp{"localhost"}.
12728 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
12729 Specifies what information is included in the Server header of HTTP
12730 responses. @code{None} disables the Server header. @code{ProductOnly}
12731 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
12732 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
12733 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
12734 the output of the @code{uname} command. @code{Full} reports @code{CUPS
12735 2.0.0 (@var{uname}) IPP/2.0}.
12737 Defaults to @samp{Minimal}.
12740 @deftypevr {@code{cups-configuration} parameter} string set-env
12741 Set the specified environment variable to be passed to child processes.
12743 Defaults to @samp{"variable value"}.
12746 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
12747 Listens on the specified interfaces for encrypted connections. Valid
12748 values are of the form @var{address}:@var{port}, where @var{address} is
12749 either an IPv6 address enclosed in brackets, an IPv4 address, or
12750 @code{*} to indicate all addresses.
12752 Defaults to @samp{()}.
12755 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
12756 Sets encryption options. By default, CUPS only supports encryption
12757 using TLS v1.0 or higher using known secure cipher suites. The
12758 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
12759 required for some older clients that do not implement newer ones. The
12760 @code{AllowSSL3} option enables SSL v3.0, which is required for some
12761 older clients that do not support TLS v1.0.
12763 Defaults to @samp{()}.
12766 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
12767 Specifies whether the scheduler requires clients to strictly adhere to
12768 the IPP specifications.
12770 Defaults to @samp{#f}.
12773 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
12774 Specifies the HTTP request timeout, in seconds.
12776 Defaults to @samp{300}.
12780 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
12781 Specifies whether the web interface is enabled.
12783 Defaults to @samp{#f}.
12786 At this point you're probably thinking ``oh dear, Guix manual, I like
12787 you but you can stop already with the configuration options''. Indeed.
12788 However, one more point: it could be that you have an existing
12789 @code{cupsd.conf} that you want to use. In that case, you can pass an
12790 @code{opaque-cups-configuration} as the configuration of a
12791 @code{cups-service-type}.
12793 Available @code{opaque-cups-configuration} fields are:
12795 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
12799 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
12800 The contents of the @code{cupsd.conf}, as a string.
12803 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
12804 The contents of the @code{cups-files.conf} file, as a string.
12807 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
12808 strings of the same name, you could instantiate a CUPS service like
12812 (service cups-service-type
12813 (opaque-cups-configuration
12814 (cupsd.conf cupsd.conf)
12815 (cups-files.conf cups-files.conf)))
12819 @node Desktop Services
12820 @subsubsection Desktop Services
12822 The @code{(gnu services desktop)} module provides services that are
12823 usually useful in the context of a ``desktop'' setup---that is, on a
12824 machine running a graphical display server, possibly with graphical user
12825 interfaces, etc. It also defines services that provide specific desktop
12826 environments like GNOME, XFCE or MATE.
12828 To simplify things, the module defines a variable containing the set of
12829 services that users typically expect on a machine with a graphical
12830 environment and networking:
12832 @defvr {Scheme Variable} %desktop-services
12833 This is a list of services that builds upon @var{%base-services} and
12834 adds or adjusts services for a typical ``desktop'' setup.
12836 In particular, it adds a graphical login manager (@pxref{X Window,
12837 @code{slim-service}}), screen lockers, a network management tool
12838 (@pxref{Networking Services, @code{network-manager-service-type}}), energy and color
12839 management services, the @code{elogind} login and seat manager, the
12840 Polkit privilege service, the GeoClue location service, the
12841 AccountsService daemon that allows authorized users change system
12842 passwords, an NTP client (@pxref{Networking Services}), the Avahi
12843 daemon, and has the name service switch service configured to be able to
12844 use @code{nss-mdns} (@pxref{Name Service Switch, mDNS}).
12847 The @var{%desktop-services} variable can be used as the @code{services}
12848 field of an @code{operating-system} declaration (@pxref{operating-system
12849 Reference, @code{services}}).
12851 Additionally, the @code{gnome-desktop-service},
12852 @code{xfce-desktop-service}, @code{mate-desktop-service} and
12853 @code{enlightenment-desktop-service-type} procedures can add GNOME, XFCE, MATE
12854 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
12855 services like the backlight adjustment helpers and the power management
12856 utilities are added to the system, extending @code{polkit} and @code{dbus}
12857 appropriately, allowing GNOME to operate with elevated privileges on a
12858 limited number of special-purpose system interfaces. Additionally,
12859 adding a service made by @code{gnome-desktop-service} adds the GNOME
12860 metapackage to the system profile. Likewise, adding the XFCE service
12861 not only adds the @code{xfce} metapackage to the system profile, but it
12862 also gives the Thunar file manager the ability to open a ``root-mode''
12863 file management window, if the user authenticates using the
12864 administrator's password via the standard polkit graphical interface.
12865 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
12866 appropriately, allowing MATE to operate with elevated privileges on a
12867 limited number of special-purpose system interfaces. Additionally,
12868 adding a service made by @code{mate-desktop-service} adds the MATE
12869 metapackage to the system profile. ``Adding ENLIGHTENMENT'' means that
12870 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
12871 are set as setuid, allowing Enlightenment's screen locker and other
12872 functionality to work as expetected.
12874 The desktop environments in Guix use the Xorg display server by
12875 default. If you'd like to use the newer display server protocol
12876 called Wayland, you need to use the @code{sddm-service} instead of the
12877 @code{slim-service} for the graphical login manager. You should then
12878 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
12879 also try starting GNOME on Wayland manually from a TTY with the
12880 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
12881 gnome-session``. Currently only GNOME has support for Wayland.
12883 @deffn {Scheme Procedure} gnome-desktop-service
12884 Return a service that adds the @code{gnome} package to the system
12885 profile, and extends polkit with the actions from
12886 @code{gnome-settings-daemon}.
12889 @deffn {Scheme Procedure} xfce-desktop-service
12890 Return a service that adds the @code{xfce} package to the system profile,
12891 and extends polkit with the ability for @code{thunar} to manipulate the
12892 file system as root from within a user session, after the user has
12893 authenticated with the administrator's password.
12896 @deffn {Scheme Procedure} mate-desktop-service
12897 Return a service that adds the @code{mate} package to the system
12898 profile, and extends polkit with the actions from
12899 @code{mate-settings-daemon}.
12902 @deffn {Scheme Procedure} enlightenment-desktop-service-type
12903 Return a service that adds the @code{enlightenment} package to the system
12904 profile, and extends dbus with actions from @code{efl}.
12907 @deftp {Data Type} enlightenment-desktop-service-configuration
12909 @item @code{enlightenment} (default @code{enlightenment})
12910 The enlightenment package to use.
12914 Because the GNOME, XFCE and MATE desktop services pull in so many packages,
12915 the default @code{%desktop-services} variable doesn't include any of
12916 them by default. To add GNOME, XFCE or MATE, just @code{cons} them onto
12917 @code{%desktop-services} in the @code{services} field of your
12918 @code{operating-system}:
12921 (use-modules (gnu))
12922 (use-service-modules desktop)
12925 ;; cons* adds items to the list given as its last argument.
12926 (services (cons* (gnome-desktop-service)
12927 (xfce-desktop-service)
12928 %desktop-services))
12932 These desktop environments will then be available as options in the
12933 graphical login window.
12935 The actual service definitions included in @code{%desktop-services} and
12936 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
12937 are described below.
12939 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
12940 Return a service that runs the ``system bus'', using @var{dbus}, with
12941 support for @var{services}.
12943 @uref{http://dbus.freedesktop.org/, D-Bus} is an inter-process communication
12944 facility. Its system bus is used to allow system services to communicate
12945 and to be notified of system-wide events.
12947 @var{services} must be a list of packages that provide an
12948 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
12949 and policy files. For example, to allow avahi-daemon to use the system bus,
12950 @var{services} must be equal to @code{(list avahi)}.
12953 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
12954 Return a service that runs the @code{elogind} login and
12955 seat management daemon. @uref{https://github.com/elogind/elogind,
12956 Elogind} exposes a D-Bus interface that can be used to know which users
12957 are logged in, know what kind of sessions they have open, suspend the
12958 system, inhibit system suspend, reboot the system, and other tasks.
12960 Elogind handles most system-level power events for a computer, for
12961 example suspending the system when a lid is closed, or shutting it down
12962 when the power button is pressed.
12964 The @var{config} keyword argument specifies the configuration for
12965 elogind, and should be the result of an @code{(elogind-configuration
12966 (@var{parameter} @var{value})...)} invocation. Available parameters and
12967 their default values are:
12970 @item kill-user-processes?
12972 @item kill-only-users
12974 @item kill-exclude-users
12976 @item inhibit-delay-max-seconds
12978 @item handle-power-key
12980 @item handle-suspend-key
12982 @item handle-hibernate-key
12984 @item handle-lid-switch
12986 @item handle-lid-switch-docked
12988 @item power-key-ignore-inhibited?
12990 @item suspend-key-ignore-inhibited?
12992 @item hibernate-key-ignore-inhibited?
12994 @item lid-switch-ignore-inhibited?
12996 @item holdoff-timeout-seconds
13000 @item idle-action-seconds
13002 @item runtime-directory-size-percent
13004 @item runtime-directory-size
13008 @item suspend-state
13009 @code{("mem" "standby" "freeze")}
13012 @item hibernate-state
13014 @item hibernate-mode
13015 @code{("platform" "shutdown")}
13016 @item hybrid-sleep-state
13018 @item hybrid-sleep-mode
13019 @code{("suspend" "platform" "shutdown")}
13023 @deffn {Scheme Procedure} accountsservice-service @
13024 [#:accountsservice @var{accountsservice}]
13025 Return a service that runs AccountsService, a system service that can
13026 list available accounts, change their passwords, and so on.
13027 AccountsService integrates with PolicyKit to enable unprivileged users
13028 to acquire the capability to modify their system configuration.
13029 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
13030 accountsservice web site} for more information.
13032 The @var{accountsservice} keyword argument is the @code{accountsservice}
13033 package to expose as a service.
13036 @deffn {Scheme Procedure} polkit-service @
13037 [#:polkit @var{polkit}]
13038 Return a service that runs the
13039 @uref{http://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
13040 management service}, which allows system administrators to grant access to
13041 privileged operations in a structured way. By querying the Polkit service, a
13042 privileged system component can know when it should grant additional
13043 capabilities to ordinary users. For example, an ordinary user can be granted
13044 the capability to suspend the system if the user is logged in locally.
13047 @deffn {Scheme Procedure} upower-service [#:upower @var{upower}] @
13048 [#:watts-up-pro? #f] @
13049 [#:poll-batteries? #t] @
13050 [#:ignore-lid? #f] @
13051 [#:use-percentage-for-policy? #f] @
13052 [#:percentage-low 10] @
13053 [#:percentage-critical 3] @
13054 [#:percentage-action 2] @
13055 [#:time-low 1200] @
13056 [#:time-critical 300] @
13057 [#:time-action 120] @
13058 [#:critical-power-action 'hybrid-sleep]
13059 Return a service that runs @uref{http://upower.freedesktop.org/,
13060 @command{upowerd}}, a system-wide monitor for power consumption and battery
13061 levels, with the given configuration settings. It implements the
13062 @code{org.freedesktop.UPower} D-Bus interface, and is notably used by
13066 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
13067 Return a service for @uref{http://udisks.freedesktop.org/docs/latest/,
13068 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
13069 notifications and ways to mount/unmount disks. Programs that talk to UDisks
13070 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
13073 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
13074 Return a service that runs @command{colord}, a system service with a D-Bus
13075 interface to manage the color profiles of input and output devices such as
13076 screens and scanners. It is notably used by the GNOME Color Manager graphical
13077 tool. See @uref{http://www.freedesktop.org/software/colord/, the colord web
13078 site} for more information.
13081 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
13082 Return a configuration allowing an application to access GeoClue
13083 location data. @var{name} is the Desktop ID of the application, without
13084 the @code{.desktop} part. If @var{allowed?} is true, the application
13085 will have access to location information by default. The boolean
13086 @var{system?} value indicates whether an application is a system component
13087 or not. Finally @var{users} is a list of UIDs of all users for which
13088 this application is allowed location info access. An empty users list
13089 means that all users are allowed.
13092 @defvr {Scheme Variable} %standard-geoclue-applications
13093 The standard list of well-known GeoClue application configurations,
13094 granting authority to the GNOME date-and-time utility to ask for the
13095 current location in order to set the time zone, and allowing the
13096 IceCat and Epiphany web browsers to request location information.
13097 IceCat and Epiphany both query the user before allowing a web page to
13098 know the user's location.
13101 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
13102 [#:whitelist '()] @
13103 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
13104 [#:submit-data? #f]
13105 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
13106 [#:submission-nick "geoclue"] @
13107 [#:applications %standard-geoclue-applications]
13108 Return a service that runs the GeoClue location service. This service
13109 provides a D-Bus interface to allow applications to request access to a
13110 user's physical location, and optionally to add information to online
13111 location databases. See
13112 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
13113 web site} for more information.
13116 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
13117 [@w{#:auto-enable? #f}]
13118 Return a service that runs the @command{bluetoothd} daemon, which
13119 manages all the Bluetooth devices and provides a number of D-Bus
13120 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
13121 powered automatically at boot, which can be useful when using a
13122 bluetooth keyboard or mouse.
13124 Users need to be in the @code{lp} group to access the D-Bus service.
13127 @node Sound Services
13128 @subsubsection Sound Services
13130 @cindex sound support
13132 @cindex PulseAudio, sound support
13134 The @code{(gnu services sound)} module provides a service to configure the
13135 Advanced Linux Sound Architecture (ALSA) system, which making PulseAudio the
13136 prefered ALSA output driver.
13138 @deffn {Scheme Variable} alsa-service-type
13139 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
13140 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
13141 configuration file. The value for this type is a @command{alsa-configuration}
13142 record as in this example:
13145 (service alsa-service-type)
13148 See below for details about @code{alsa-configuration}.
13151 @deftp {Data Type} alsa-configuration
13152 Data type representing the configuration for @code{alsa-service}.
13155 @item @code{alsa-plugins} (default: @var{alsa-plugins})
13156 @code{alsa-plugins} package to use.
13158 @item @code{pulseaudio?} (default: @var{#t})
13159 Whether ALSA applications should transparently be made to use the
13160 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
13162 Using PulseAudio allows you to run several sound-producing applications
13163 at the same time and to individual control them @i{via}
13164 @command{pavucontrol}, among other things.
13166 @item @code{extra-options} (default: @var{""})
13167 String to append to the @file{/etc/asound.conf} file.
13172 Individual users who want to override the system configuration of ALSA can do
13173 it with the @file{~/.asoundrc} file:
13176 # In guix, we have to specify the absolute path for plugins.
13178 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
13181 # Routing ALSA to jack:
13182 # <http://jackaudio.org/faq/routing_alsa.html>.
13186 0 system:playback_1
13187 1 system:playback_2
13204 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
13208 @node Database Services
13209 @subsubsection Database Services
13213 The @code{(gnu services databases)} module provides the following services.
13215 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
13216 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
13217 [#:port 5432] [#:locale ``en_US.utf8'']
13218 Return a service that runs @var{postgresql}, the PostgreSQL database
13221 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
13222 creates a database cluster with @var{locale} as the default
13223 locale, stored in @var{data-directory}. It then listens on @var{port}.
13226 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
13227 Return a service that runs @command{mysqld}, the MySQL or MariaDB
13230 The optional @var{config} argument specifies the configuration for
13231 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
13234 @deftp {Data Type} mysql-configuration
13235 Data type representing the configuration of @var{mysql-service}.
13238 @item @code{mysql} (default: @var{mariadb})
13239 Package object of the MySQL database server, can be either @var{mariadb}
13242 For MySQL, a temporary root password will be displayed at activation time.
13243 For MariaDB, the root password is empty.
13245 @item @code{port} (default: @code{3306})
13246 TCP port on which the database server listens for incoming connections.
13250 @defvr {Scheme Variable} memcached-service-type
13251 This is the service type for the @uref{https://memcached.org/,
13252 Memcached} service, which provides a distributed in memory cache. The
13253 value for the service type is a @code{memcached-configuration} object.
13257 (service memcached-service-type)
13260 @deftp {Data Type} memcached-configuration
13261 Data type representing the configuration of memcached.
13264 @item @code{memcached} (default: @code{memcached})
13265 The Memcached package to use.
13267 @item @code{interfaces} (default: @code{'("0.0.0.0")})
13268 Network interfaces on which to listen.
13270 @item @code{tcp-port} (default: @code{11211})
13271 Port on which to accept connections on,
13273 @item @code{udp-port} (default: @code{11211})
13274 Port on which to accept UDP connections on, a value of 0 will disable
13275 listening on a UDP socket.
13277 @item @code{additional-options} (default: @code{'()})
13278 Additional command line options to pass to @code{memcached}.
13282 @defvr {Scheme Variable} mongodb-service-type
13283 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
13284 The value for the service type is a @code{mongodb-configuration} object.
13288 (service mongodb-service-type)
13291 @deftp {Data Type} mongodb-configuration
13292 Data type representing the configuration of mongodb.
13295 @item @code{mongodb} (default: @code{mongodb})
13296 The MongoDB package to use.
13298 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
13299 The configuration file for MongoDB.
13301 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
13302 This value is used to create the directory, so that it exists and is
13303 owned by the mongodb user. It should match the data-directory which
13304 MongoDB is configured to use through the configuration file.
13308 @defvr {Scheme Variable} redis-service-type
13309 This is the service type for the @uref{https://redis.io/, Redis}
13310 key/value store, whose value is a @code{redis-configuration} object.
13313 @deftp {Data Type} redis-configuration
13314 Data type representing the configuration of redis.
13317 @item @code{redis} (default: @code{redis})
13318 The Redis package to use.
13320 @item @code{bind} (default: @code{"127.0.0.1"})
13321 Network interface on which to listen.
13323 @item @code{port} (default: @code{6379})
13324 Port on which to accept connections on, a value of 0 will disable
13325 listening on a TCP socket.
13327 @item @code{working-directory} (default: @code{"/var/lib/redis"})
13328 Directory in which to store the database and related files.
13332 @node Mail Services
13333 @subsubsection Mail Services
13337 The @code{(gnu services mail)} module provides Guix service definitions
13338 for email services: IMAP, POP3, and LMTP servers, as well as mail
13339 transport agents (MTAs). Lots of acronyms! These services are detailed
13340 in the subsections below.
13342 @subsubheading Dovecot Service
13344 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
13345 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
13348 By default, Dovecot does not need much configuration; the default
13349 configuration object created by @code{(dovecot-configuration)} will
13350 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
13351 certificate will be generated for TLS-protected connections, though
13352 Dovecot will also listen on cleartext ports by default. There are a
13353 number of options, though, which mail administrators might need to change,
13354 and as is the case with other services, Guix allows the system
13355 administrator to specify these parameters via a uniform Scheme interface.
13357 For example, to specify that mail is located at @code{maildir~/.mail},
13358 one would instantiate the Dovecot service like this:
13361 (dovecot-service #:config
13362 (dovecot-configuration
13363 (mail-location "maildir:~/.mail")))
13366 The available configuration parameters follow. Each parameter
13367 definition is preceded by its type; for example, @samp{string-list foo}
13368 indicates that the @code{foo} parameter should be specified as a list of
13369 strings. There is also a way to specify the configuration as a string,
13370 if you have an old @code{dovecot.conf} file that you want to port over
13371 from some other system; see the end for more details.
13373 @c The following documentation was initially generated by
13374 @c (generate-documentation) in (gnu services mail). Manually maintained
13375 @c documentation is better, so we shouldn't hesitate to edit below as
13376 @c needed. However if the change you want to make to this documentation
13377 @c can be done in an automated way, it's probably easier to change
13378 @c (generate-documentation) than to make it below and have to deal with
13379 @c the churn as dovecot updates.
13381 Available @code{dovecot-configuration} fields are:
13383 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
13384 The dovecot package.
13387 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
13388 A list of IPs or hosts where to listen for connections. @samp{*}
13389 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
13390 interfaces. If you want to specify non-default ports or anything more
13391 complex, customize the address and port fields of the
13392 @samp{inet-listener} of the specific services you are interested in.
13395 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
13396 List of protocols we want to serve. Available protocols include
13397 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
13399 Available @code{protocol-configuration} fields are:
13401 @deftypevr {@code{protocol-configuration} parameter} string name
13402 The name of the protocol.
13405 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
13406 UNIX socket path to the master authentication server to find users.
13407 This is used by imap (for shared users) and lda.
13408 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
13411 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
13412 Space separated list of plugins to load.
13415 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
13416 Maximum number of IMAP connections allowed for a user from each IP
13417 address. NOTE: The username is compared case-sensitively.
13418 Defaults to @samp{10}.
13423 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
13424 List of services to enable. Available services include @samp{imap},
13425 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
13428 Available @code{service-configuration} fields are:
13430 @deftypevr {@code{service-configuration} parameter} string kind
13431 The service kind. Valid values include @code{director},
13432 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
13433 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
13434 @code{tcpwrap}, @code{quota-warning}, or anything else.
13437 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
13438 Listeners for the service. A listener is either a
13439 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
13440 an @code{inet-listener-configuration}.
13441 Defaults to @samp{()}.
13443 Available @code{unix-listener-configuration} fields are:
13445 @deftypevr {@code{unix-listener-configuration} parameter} string path
13446 Path to the file, relative to @code{base-dir} field. This is also used as
13450 @deftypevr {@code{unix-listener-configuration} parameter} string mode
13451 The access mode for the socket.
13452 Defaults to @samp{"0600"}.
13455 @deftypevr {@code{unix-listener-configuration} parameter} string user
13456 The user to own the socket.
13457 Defaults to @samp{""}.
13460 @deftypevr {@code{unix-listener-configuration} parameter} string group
13461 The group to own the socket.
13462 Defaults to @samp{""}.
13466 Available @code{fifo-listener-configuration} fields are:
13468 @deftypevr {@code{fifo-listener-configuration} parameter} string path
13469 Path to the file, relative to @code{base-dir} field. This is also used as
13473 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
13474 The access mode for the socket.
13475 Defaults to @samp{"0600"}.
13478 @deftypevr {@code{fifo-listener-configuration} parameter} string user
13479 The user to own the socket.
13480 Defaults to @samp{""}.
13483 @deftypevr {@code{fifo-listener-configuration} parameter} string group
13484 The group to own the socket.
13485 Defaults to @samp{""}.
13489 Available @code{inet-listener-configuration} fields are:
13491 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
13492 The protocol to listen for.
13495 @deftypevr {@code{inet-listener-configuration} parameter} string address
13496 The address on which to listen, or empty for all addresses.
13497 Defaults to @samp{""}.
13500 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
13501 The port on which to listen.
13504 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
13505 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
13507 Defaults to @samp{#t}.
13512 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
13513 Number of connections to handle before starting a new process.
13514 Typically the only useful values are 0 (unlimited) or 1. 1 is more
13515 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
13516 Defaults to @samp{1}.
13519 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
13520 Number of processes to always keep waiting for more connections.
13521 Defaults to @samp{0}.
13524 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
13525 If you set @samp{service-count 0}, you probably need to grow
13527 Defaults to @samp{256000000}.
13532 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
13533 Dict configuration, as created by the @code{dict-configuration}
13536 Available @code{dict-configuration} fields are:
13538 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
13539 A list of key-value pairs that this dict should hold.
13540 Defaults to @samp{()}.
13545 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
13546 A list of passdb configurations, each one created by the
13547 @code{passdb-configuration} constructor.
13549 Available @code{passdb-configuration} fields are:
13551 @deftypevr {@code{passdb-configuration} parameter} string driver
13552 The driver that the passdb should use. Valid values include
13553 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
13555 Defaults to @samp{"pam"}.
13558 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
13559 Space separated list of arguments to the passdb driver.
13560 Defaults to @samp{""}.
13565 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
13566 List of userdb configurations, each one created by the
13567 @code{userdb-configuration} constructor.
13569 Available @code{userdb-configuration} fields are:
13571 @deftypevr {@code{userdb-configuration} parameter} string driver
13572 The driver that the userdb should use. Valid values include
13573 @samp{passwd} and @samp{static}.
13574 Defaults to @samp{"passwd"}.
13577 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
13578 Space separated list of arguments to the userdb driver.
13579 Defaults to @samp{""}.
13582 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
13583 Override fields from passwd.
13584 Defaults to @samp{()}.
13589 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
13590 Plug-in configuration, created by the @code{plugin-configuration}
13594 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
13595 List of namespaces. Each item in the list is created by the
13596 @code{namespace-configuration} constructor.
13598 Available @code{namespace-configuration} fields are:
13600 @deftypevr {@code{namespace-configuration} parameter} string name
13601 Name for this namespace.
13604 @deftypevr {@code{namespace-configuration} parameter} string type
13605 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
13606 Defaults to @samp{"private"}.
13609 @deftypevr {@code{namespace-configuration} parameter} string separator
13610 Hierarchy separator to use. You should use the same separator for
13611 all namespaces or some clients get confused. @samp{/} is usually a good
13612 one. The default however depends on the underlying mail storage
13614 Defaults to @samp{""}.
13617 @deftypevr {@code{namespace-configuration} parameter} string prefix
13618 Prefix required to access this namespace. This needs to be
13619 different for all namespaces. For example @samp{Public/}.
13620 Defaults to @samp{""}.
13623 @deftypevr {@code{namespace-configuration} parameter} string location
13624 Physical location of the mailbox. This is in the same format as
13625 mail_location, which is also the default for it.
13626 Defaults to @samp{""}.
13629 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
13630 There can be only one INBOX, and this setting defines which
13632 Defaults to @samp{#f}.
13635 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
13636 If namespace is hidden, it's not advertised to clients via NAMESPACE
13637 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
13638 useful when converting from another server with different namespaces
13639 which you want to deprecate but still keep working. For example you can
13640 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
13642 Defaults to @samp{#f}.
13645 @deftypevr {@code{namespace-configuration} parameter} boolean list?
13646 Show the mailboxes under this namespace with the LIST command. This
13647 makes the namespace visible for clients that do not support the NAMESPACE
13648 extension. The special @code{children} value lists child mailboxes, but
13649 hides the namespace prefix.
13650 Defaults to @samp{#t}.
13653 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
13654 Namespace handles its own subscriptions. If set to @code{#f}, the
13655 parent namespace handles them. The empty prefix should always have this
13657 Defaults to @samp{#t}.
13660 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
13661 List of predefined mailboxes in this namespace.
13662 Defaults to @samp{()}.
13664 Available @code{mailbox-configuration} fields are:
13666 @deftypevr {@code{mailbox-configuration} parameter} string name
13667 Name for this mailbox.
13670 @deftypevr {@code{mailbox-configuration} parameter} string auto
13671 @samp{create} will automatically create this mailbox.
13672 @samp{subscribe} will both create and subscribe to the mailbox.
13673 Defaults to @samp{"no"}.
13676 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
13677 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
13678 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
13679 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
13680 Defaults to @samp{()}.
13687 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
13688 Base directory where to store runtime data.
13689 Defaults to @samp{"/var/run/dovecot/"}.
13692 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
13693 Greeting message for clients.
13694 Defaults to @samp{"Dovecot ready."}.
13697 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
13698 List of trusted network ranges. Connections from these IPs are
13699 allowed to override their IP addresses and ports (for logging and for
13700 authentication checks). @samp{disable-plaintext-auth} is also ignored
13701 for these networks. Typically you would specify your IMAP proxy servers
13703 Defaults to @samp{()}.
13706 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
13707 List of login access check sockets (e.g. tcpwrap).
13708 Defaults to @samp{()}.
13711 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
13712 Show more verbose process titles (in ps). Currently shows user name
13713 and IP address. Useful for seeing who is actually using the IMAP
13714 processes (e.g. shared mailboxes or if the same uid is used for multiple
13716 Defaults to @samp{#f}.
13719 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
13720 Should all processes be killed when Dovecot master process shuts down.
13721 Setting this to @code{#f} means that Dovecot can be upgraded without
13722 forcing existing client connections to close (although that could also
13723 be a problem if the upgrade is e.g. due to a security fix).
13724 Defaults to @samp{#t}.
13727 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
13728 If non-zero, run mail commands via this many connections to doveadm
13729 server, instead of running them directly in the same process.
13730 Defaults to @samp{0}.
13733 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
13734 UNIX socket or host:port used for connecting to doveadm server.
13735 Defaults to @samp{"doveadm-server"}.
13738 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
13739 List of environment variables that are preserved on Dovecot startup
13740 and passed down to all of its child processes. You can also give
13741 key=value pairs to always set specific settings.
13744 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
13745 Disable LOGIN command and all other plaintext authentications unless
13746 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
13747 matches the local IP (i.e. you're connecting from the same computer),
13748 the connection is considered secure and plaintext authentication is
13749 allowed. See also ssl=required setting.
13750 Defaults to @samp{#t}.
13753 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
13754 Authentication cache size (e.g. @samp{#e10e6}). 0 means it's disabled.
13755 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
13756 for caching to be used.
13757 Defaults to @samp{0}.
13760 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
13761 Time to live for cached data. After TTL expires the cached record
13762 is no longer used, *except* if the main database lookup returns internal
13763 failure. We also try to handle password changes automatically: If
13764 user's previous authentication was successful, but this one wasn't, the
13765 cache isn't used. For now this works only with plaintext
13767 Defaults to @samp{"1 hour"}.
13770 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
13771 TTL for negative hits (user not found, password mismatch).
13772 0 disables caching them completely.
13773 Defaults to @samp{"1 hour"}.
13776 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
13777 List of realms for SASL authentication mechanisms that need them.
13778 You can leave it empty if you don't want to support multiple realms.
13779 Many clients simply use the first one listed here, so keep the default
13781 Defaults to @samp{()}.
13784 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
13785 Default realm/domain to use if none was specified. This is used for
13786 both SASL realms and appending @@domain to username in plaintext
13788 Defaults to @samp{""}.
13791 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
13792 List of allowed characters in username. If the user-given username
13793 contains a character not listed in here, the login automatically fails.
13794 This is just an extra check to make sure user can't exploit any
13795 potential quote escaping vulnerabilities with SQL/LDAP databases. If
13796 you want to allow all characters, set this value to empty.
13797 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
13800 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
13801 Username character translations before it's looked up from
13802 databases. The value contains series of from -> to characters. For
13803 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
13804 translated to @samp{@@}.
13805 Defaults to @samp{""}.
13808 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
13809 Username formatting before it's looked up from databases. You can
13810 use the standard variables here, e.g. %Lu would lowercase the username,
13811 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
13812 change the @samp{@@} into @samp{-AT-}. This translation is done after
13813 @samp{auth-username-translation} changes.
13814 Defaults to @samp{"%Lu"}.
13817 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
13818 If you want to allow master users to log in by specifying the master
13819 username within the normal username string (i.e. not using SASL
13820 mechanism's support for it), you can specify the separator character
13821 here. The format is then <username><separator><master username>.
13822 UW-IMAP uses @samp{*} as the separator, so that could be a good
13824 Defaults to @samp{""}.
13827 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
13828 Username to use for users logging in with ANONYMOUS SASL
13830 Defaults to @samp{"anonymous"}.
13833 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
13834 Maximum number of dovecot-auth worker processes. They're used to
13835 execute blocking passdb and userdb queries (e.g. MySQL and PAM).
13836 They're automatically created and destroyed as needed.
13837 Defaults to @samp{30}.
13840 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
13841 Host name to use in GSSAPI principal names. The default is to use
13842 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
13843 allow all keytab entries.
13844 Defaults to @samp{""}.
13847 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
13848 Kerberos keytab to use for the GSSAPI mechanism. Will use the
13849 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
13850 need to change the auth service to run as root to be able to read this
13852 Defaults to @samp{""}.
13855 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
13856 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
13857 and @samp{ntlm-auth} helper.
13858 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
13859 Defaults to @samp{#f}.
13862 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
13863 Path for Samba's @samp{ntlm-auth} helper binary.
13864 Defaults to @samp{"/usr/bin/ntlm_auth"}.
13867 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
13868 Time to delay before replying to failed authentications.
13869 Defaults to @samp{"2 secs"}.
13872 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
13873 Require a valid SSL client certificate or the authentication
13875 Defaults to @samp{#f}.
13878 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
13879 Take the username from client's SSL certificate, using
13880 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
13882 Defaults to @samp{#f}.
13885 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
13886 List of wanted authentication mechanisms. Supported mechanisms are:
13887 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
13888 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
13889 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
13890 @samp{disable-plaintext-auth} setting.
13893 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
13894 List of IPs or hostnames to all director servers, including ourself.
13895 Ports can be specified as ip:port. The default port is the same as what
13896 director service's @samp{inet-listener} is using.
13897 Defaults to @samp{()}.
13900 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
13901 List of IPs or hostnames to all backend mail servers. Ranges are
13902 allowed too, like 10.0.0.10-10.0.0.30.
13903 Defaults to @samp{()}.
13906 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
13907 How long to redirect users to a specific server after it no longer
13908 has any connections.
13909 Defaults to @samp{"15 min"}.
13912 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
13913 How the username is translated before being hashed. Useful values
13914 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
13915 are shared within domain.
13916 Defaults to @samp{"%Lu"}.
13919 @deftypevr {@code{dovecot-configuration} parameter} string log-path
13920 Log file to use for error messages. @samp{syslog} logs to syslog,
13921 @samp{/dev/stderr} logs to stderr.
13922 Defaults to @samp{"syslog"}.
13925 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
13926 Log file to use for informational messages. Defaults to
13928 Defaults to @samp{""}.
13931 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
13932 Log file to use for debug messages. Defaults to
13933 @samp{info-log-path}.
13934 Defaults to @samp{""}.
13937 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
13938 Syslog facility to use if you're logging to syslog. Usually if you
13939 don't want to use @samp{mail}, you'll use local0..local7. Also other
13940 standard facilities are supported.
13941 Defaults to @samp{"mail"}.
13944 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
13945 Log unsuccessful authentication attempts and the reasons why they
13947 Defaults to @samp{#f}.
13950 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose-passwords?
13951 In case of password mismatches, log the attempted password. Valid
13952 values are no, plain and sha1. sha1 can be useful for detecting brute
13953 force password attempts vs. user simply trying the same password over
13954 and over again. You can also truncate the value to n chars by appending
13955 ":n" (e.g. sha1:6).
13956 Defaults to @samp{#f}.
13959 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
13960 Even more verbose logging for debugging purposes. Shows for example
13962 Defaults to @samp{#f}.
13965 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
13966 In case of password mismatches, log the passwords and used scheme so
13967 the problem can be debugged. Enabling this also enables
13969 Defaults to @samp{#f}.
13972 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
13973 Enable mail process debugging. This can help you figure out why
13974 Dovecot isn't finding your mails.
13975 Defaults to @samp{#f}.
13978 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
13979 Show protocol level SSL errors.
13980 Defaults to @samp{#f}.
13983 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
13984 Prefix for each line written to log file. % codes are in
13985 strftime(3) format.
13986 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
13989 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
13990 List of elements we want to log. The elements which have a
13991 non-empty variable value are joined together to form a comma-separated
13995 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
13996 Login log format. %s contains @samp{login-log-format-elements}
13997 string, %$ contains the data we want to log.
13998 Defaults to @samp{"%$: %s"}.
14001 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
14002 Log prefix for mail processes. See doc/wiki/Variables.txt for list
14003 of possible variables you can use.
14004 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
14007 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
14008 Format to use for logging mail deliveries. You can use variables:
14011 Delivery status message (e.g. @samp{saved to INBOX})
14023 Defaults to @samp{"msgid=%m: %$"}.
14026 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
14027 Location for users' mailboxes. The default is empty, which means
14028 that Dovecot tries to find the mailboxes automatically. This won't work
14029 if the user doesn't yet have any mail, so you should explicitly tell
14030 Dovecot the full location.
14032 If you're using mbox, giving a path to the INBOX
14033 file (e.g. /var/mail/%u) isn't enough. You'll also need to tell Dovecot
14034 where the other mailboxes are kept. This is called the "root mail
14035 directory", and it must be the first path given in the
14036 @samp{mail-location} setting.
14038 There are a few special variables you can use, eg.:
14044 user part in user@@domain, same as %u if there's no domain
14046 domain part in user@@domain, empty if there's no domain
14051 See doc/wiki/Variables.txt for full list. Some examples:
14053 @item maildir:~/Maildir
14054 @item mbox:~/mail:INBOX=/var/mail/%u
14055 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
14057 Defaults to @samp{""}.
14060 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
14061 System user and group used to access mails. If you use multiple,
14062 userdb can override these by returning uid or gid fields. You can use
14063 either numbers or names. <doc/wiki/UserIds.txt>.
14064 Defaults to @samp{""}.
14067 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
14069 Defaults to @samp{""}.
14072 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
14073 Group to enable temporarily for privileged operations. Currently
14074 this is used only with INBOX when either its initial creation or
14075 dotlocking fails. Typically this is set to "mail" to give access to
14077 Defaults to @samp{""}.
14080 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
14081 Grant access to these supplementary groups for mail processes.
14082 Typically these are used to set up access to shared mailboxes. Note
14083 that it may be dangerous to set these if users can create
14084 symlinks (e.g. if "mail" group is set here, ln -s /var/mail ~/mail/var
14085 could allow a user to delete others' mailboxes, or ln -s
14086 /secret/shared/box ~/mail/mybox would allow reading it).
14087 Defaults to @samp{""}.
14090 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
14091 Allow full file system access to clients. There's no access checks
14092 other than what the operating system does for the active UID/GID. It
14093 works with both maildir and mboxes, allowing you to prefix mailboxes
14094 names with e.g. /path/ or ~user/.
14095 Defaults to @samp{#f}.
14098 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
14099 Don't use mmap() at all. This is required if you store indexes to
14100 shared file systems (NFS or clustered file system).
14101 Defaults to @samp{#f}.
14104 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
14105 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
14106 supports @samp{O_EXCL} since version 3, so this should be safe to use
14107 nowadays by default.
14108 Defaults to @samp{#t}.
14111 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
14112 When to use fsync() or fdatasync() calls:
14115 Whenever necessary to avoid losing important data
14117 Useful with e.g. NFS when write()s are delayed
14119 Never use it (best performance, but crashes can lose data).
14121 Defaults to @samp{"optimized"}.
14124 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
14125 Mail storage exists in NFS. Set this to yes to make Dovecot flush
14126 NFS caches whenever needed. If you're using only a single mail server
14128 Defaults to @samp{#f}.
14131 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
14132 Mail index files also exist in NFS. Setting this to yes requires
14133 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
14134 Defaults to @samp{#f}.
14137 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
14138 Locking method for index files. Alternatives are fcntl, flock and
14139 dotlock. Dotlocking uses some tricks which may create more disk I/O
14140 than other locking methods. NFS users: flock doesn't work, remember to
14141 change @samp{mmap-disable}.
14142 Defaults to @samp{"fcntl"}.
14145 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
14146 Directory in which LDA/LMTP temporarily stores incoming mails >128
14148 Defaults to @samp{"/tmp"}.
14151 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
14152 Valid UID range for users. This is mostly to make sure that users can't
14153 log in as daemons or other system users. Note that denying root logins is
14154 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
14156 Defaults to @samp{500}.
14159 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
14161 Defaults to @samp{0}.
14164 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
14165 Valid GID range for users. Users having non-valid GID as primary group ID
14166 aren't allowed to log in. If user belongs to supplementary groups with
14167 non-valid GIDs, those groups are not set.
14168 Defaults to @samp{1}.
14171 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
14173 Defaults to @samp{0}.
14176 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
14177 Maximum allowed length for mail keyword name. It's only forced when
14178 trying to create new keywords.
14179 Defaults to @samp{50}.
14182 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
14183 List of directories under which chrooting is allowed for mail
14184 processes (i.e. /var/mail will allow chrooting to /var/mail/foo/bar
14185 too). This setting doesn't affect @samp{login-chroot}
14186 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
14187 "/./" in home dirs are ignored. WARNING: Never add directories here
14188 which local users can modify, that may lead to root exploit. Usually
14189 this should be done only if you don't allow shell access for users.
14190 <doc/wiki/Chrooting.txt>.
14191 Defaults to @samp{()}.
14194 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
14195 Default chroot directory for mail processes. This can be overridden
14196 for specific users in user database by giving /./ in user's home
14197 directory (e.g. /home/./user chroots into /home). Note that usually
14198 there is no real need to do chrooting, Dovecot doesn't allow users to
14199 access files outside their mail directory anyway. If your home
14200 directories are prefixed with the chroot directory, append "/." to
14201 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
14202 Defaults to @samp{""}.
14205 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
14206 UNIX socket path to master authentication server to find users.
14207 This is used by imap (for shared users) and lda.
14208 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
14211 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
14212 Directory where to look up mail plugins.
14213 Defaults to @samp{"/usr/lib/dovecot"}.
14216 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
14217 List of plugins to load for all services. Plugins specific to IMAP,
14218 LDA, etc. are added to this list in their own .conf files.
14219 Defaults to @samp{()}.
14222 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
14223 The minimum number of mails in a mailbox before updates are done to
14224 cache file. This allows optimizing Dovecot's behavior to do less disk
14225 writes at the cost of more disk reads.
14226 Defaults to @samp{0}.
14229 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
14230 When IDLE command is running, mailbox is checked once in a while to
14231 see if there are any new mails or other changes. This setting defines
14232 the minimum time to wait between those checks. Dovecot can also use
14233 dnotify, inotify and kqueue to find out immediately when changes
14235 Defaults to @samp{"30 secs"}.
14238 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
14239 Save mails with CR+LF instead of plain LF. This makes sending those
14240 mails take less CPU, especially with sendfile() syscall with Linux and
14241 FreeBSD. But it also creates a bit more disk I/O which may just make it
14242 slower. Also note that if other software reads the mboxes/maildirs,
14243 they may handle the extra CRs wrong and cause problems.
14244 Defaults to @samp{#f}.
14247 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
14248 By default LIST command returns all entries in maildir beginning
14249 with a dot. Enabling this option makes Dovecot return only entries
14250 which are directories. This is done by stat()ing each entry, so it
14251 causes more disk I/O.
14252 (For systems setting struct @samp{dirent->d_type} this check is free
14253 and it's done always regardless of this setting).
14254 Defaults to @samp{#f}.
14257 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
14258 When copying a message, do it with hard links whenever possible.
14259 This makes the performance much better, and it's unlikely to have any
14261 Defaults to @samp{#t}.
14264 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
14265 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
14266 directory only when its mtime changes unexpectedly or when we can't find
14267 the mail otherwise.
14268 Defaults to @samp{#f}.
14271 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
14272 Which locking methods to use for locking mbox. There are four
14277 Create <mailbox>.lock file. This is the oldest and most NFS-safe
14278 solution. If you want to use /var/mail/ like directory, the users will
14279 need write access to that directory.
14281 Same as dotlock, but if it fails because of permissions or because there
14282 isn't enough disk space, just skip it.
14284 Use this if possible. Works with NFS too if lockd is used.
14286 May not exist in all systems. Doesn't work with NFS.
14288 May not exist in all systems. Doesn't work with NFS.
14291 You can use multiple locking methods; if you do the order they're declared
14292 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
14293 locking methods as well. Some operating systems don't allow using some of
14294 them simultaneously.
14297 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
14301 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
14302 Maximum time to wait for lock (all of them) before aborting.
14303 Defaults to @samp{"5 mins"}.
14306 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
14307 If dotlock exists but the mailbox isn't modified in any way,
14308 override the lock file after this much time.
14309 Defaults to @samp{"2 mins"}.
14312 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
14313 When mbox changes unexpectedly we have to fully read it to find out
14314 what changed. If the mbox is large this can take a long time. Since
14315 the change is usually just a newly appended mail, it'd be faster to
14316 simply read the new mails. If this setting is enabled, Dovecot does
14317 this but still safely fallbacks to re-reading the whole mbox file
14318 whenever something in mbox isn't how it's expected to be. The only real
14319 downside to this setting is that if some other MUA changes message
14320 flags, Dovecot doesn't notice it immediately. Note that a full sync is
14321 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
14322 Defaults to @samp{#t}.
14325 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
14326 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
14327 EXAMINE, EXPUNGE or CHECK commands. If this is set,
14328 @samp{mbox-dirty-syncs} is ignored.
14329 Defaults to @samp{#f}.
14332 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
14333 Delay writing mbox headers until doing a full write sync (EXPUNGE
14334 and CHECK commands and when closing the mailbox). This is especially
14335 useful for POP3 where clients often delete all mails. The downside is
14336 that our changes aren't immediately visible to other MUAs.
14337 Defaults to @samp{#t}.
14340 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
14341 If mbox size is smaller than this (e.g. 100k), don't write index
14342 files. If an index file already exists it's still read, just not
14344 Defaults to @samp{0}.
14347 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
14348 Maximum dbox file size until it's rotated.
14349 Defaults to @samp{10000000}.
14352 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
14353 Maximum dbox file age until it's rotated. Typically in days. Day
14354 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
14356 Defaults to @samp{"1d"}.
14359 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
14360 When creating new mdbox files, immediately preallocate their size to
14361 @samp{mdbox-rotate-size}. This setting currently works only in Linux
14362 with some file systems (ext4, xfs).
14363 Defaults to @samp{#f}.
14366 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
14367 sdbox and mdbox support saving mail attachments to external files,
14368 which also allows single instance storage for them. Other backends
14369 don't support this for now.
14371 WARNING: This feature hasn't been tested much yet. Use at your own risk.
14373 Directory root where to store mail attachments. Disabled, if empty.
14374 Defaults to @samp{""}.
14377 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
14378 Attachments smaller than this aren't saved externally. It's also
14379 possible to write a plugin to disable saving specific attachments
14381 Defaults to @samp{128000}.
14384 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
14385 File system backend to use for saving attachments:
14388 No SiS done by Dovecot (but this might help FS's own deduplication)
14390 SiS with immediate byte-by-byte comparison during saving
14391 @item sis-queue posix
14392 SiS with delayed comparison and deduplication.
14394 Defaults to @samp{"sis posix"}.
14397 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
14398 Hash format to use in attachment filenames. You can add any text and
14399 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
14400 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
14401 truncated, e.g. @code{%@{sha256:80@}} returns only first 80 bits.
14402 Defaults to @samp{"%@{sha1@}"}.
14405 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
14407 Defaults to @samp{100}.
14410 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
14412 Defaults to @samp{1000}.
14415 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
14416 Default VSZ (virtual memory size) limit for service processes.
14417 This is mainly intended to catch and kill processes that leak memory
14418 before they eat up everything.
14419 Defaults to @samp{256000000}.
14422 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
14423 Login user is internally used by login processes. This is the most
14424 untrusted user in Dovecot system. It shouldn't have access to anything
14426 Defaults to @samp{"dovenull"}.
14429 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
14430 Internal user is used by unprivileged processes. It should be
14431 separate from login user, so that login processes can't disturb other
14433 Defaults to @samp{"dovecot"}.
14436 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
14437 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
14438 Defaults to @samp{"required"}.
14441 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
14442 PEM encoded X.509 SSL/TLS certificate (public key).
14443 Defaults to @samp{"</etc/dovecot/default.pem"}.
14446 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
14447 PEM encoded SSL/TLS private key. The key is opened before
14448 dropping root privileges, so keep the key file unreadable by anyone but
14450 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
14453 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
14454 If key file is password protected, give the password here.
14455 Alternatively give it when starting dovecot with -p parameter. Since
14456 this file is often world-readable, you may want to place this setting
14457 instead to a different.
14458 Defaults to @samp{""}.
14461 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
14462 PEM encoded trusted certificate authority. Set this only if you
14463 intend to use @samp{ssl-verify-client-cert? #t}. The file should
14464 contain the CA certificate(s) followed by the matching
14465 CRL(s). (e.g. @samp{ssl-ca </etc/ssl/certs/ca.pem}).
14466 Defaults to @samp{""}.
14469 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
14470 Require that CRL check succeeds for client certificates.
14471 Defaults to @samp{#t}.
14474 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
14475 Request client to send a certificate. If you also want to require
14476 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
14477 Defaults to @samp{#f}.
14480 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
14481 Which field from certificate to use for username. commonName and
14482 x500UniqueIdentifier are the usual choices. You'll also need to set
14483 @samp{auth-ssl-username-from-cert? #t}.
14484 Defaults to @samp{"commonName"}.
14487 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
14488 Minimum SSL protocol version to accept.
14489 Defaults to @samp{"TLSv1"}.
14492 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
14493 SSL ciphers to use.
14494 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
14497 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
14498 SSL crypto device to use, for valid values run "openssl engine".
14499 Defaults to @samp{""}.
14502 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
14503 Address to use when sending rejection mails.
14504 %d expands to recipient domain.
14505 Defaults to @samp{"postmaster@@%d"}.
14508 @deftypevr {@code{dovecot-configuration} parameter} string hostname
14509 Hostname to use in various parts of sent mails (e.g. in Message-Id)
14510 and in LMTP replies. Default is the system's real hostname@@domain.
14511 Defaults to @samp{""}.
14514 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
14515 If user is over quota, return with temporary failure instead of
14517 Defaults to @samp{#f}.
14520 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
14521 Binary to use for sending mails.
14522 Defaults to @samp{"/usr/sbin/sendmail"}.
14525 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
14526 If non-empty, send mails via this SMTP host[:port] instead of
14528 Defaults to @samp{""}.
14531 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
14532 Subject: header to use for rejection mails. You can use the same
14533 variables as for @samp{rejection-reason} below.
14534 Defaults to @samp{"Rejected: %s"}.
14537 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
14538 Human readable error message for rejection mails. You can use
14551 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
14554 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
14555 Delimiter character between local-part and detail in email
14557 Defaults to @samp{"+"}.
14560 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
14561 Header where the original recipient address (SMTP's RCPT TO:
14562 address) is taken from if not available elsewhere. With dovecot-lda -a
14563 parameter overrides this. A commonly used header for this is
14565 Defaults to @samp{""}.
14568 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
14569 Should saving a mail to a nonexistent mailbox automatically create
14571 Defaults to @samp{#f}.
14574 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
14575 Should automatically created mailboxes be also automatically
14577 Defaults to @samp{#f}.
14580 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
14581 Maximum IMAP command line length. Some clients generate very long
14582 command lines with huge mailboxes, so you may need to raise this if you
14583 get "Too long argument" or "IMAP command line too large" errors
14585 Defaults to @samp{64000}.
14588 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
14589 IMAP logout format string:
14592 total number of bytes read from client
14594 total number of bytes sent to client.
14596 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
14597 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@}"}.
14600 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
14601 Override the IMAP CAPABILITY response. If the value begins with '+',
14602 add the given capabilities on top of the defaults (e.g. +XFOO XBAR).
14603 Defaults to @samp{""}.
14606 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
14607 How long to wait between "OK Still here" notifications when client
14609 Defaults to @samp{"2 mins"}.
14612 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
14613 ID field names and values to send to clients. Using * as the value
14614 makes Dovecot use the default value. The following fields have default
14615 values currently: name, version, os, os-version, support-url,
14617 Defaults to @samp{""}.
14620 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
14621 ID fields sent by client to log. * means everything.
14622 Defaults to @samp{""}.
14625 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
14626 Workarounds for various client bugs:
14629 @item delay-newmail
14630 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
14631 CHECK commands. Some clients ignore them otherwise, for example OSX
14632 Mail (<v2.1). Outlook Express breaks more badly though, without this it
14633 may show user "Message no longer in server" errors. Note that OE6
14634 still breaks even with this workaround if synchronization is set to
14637 @item tb-extra-mailbox-sep
14638 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
14639 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
14640 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
14642 @item tb-lsub-flags
14643 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g. mbox).
14644 This makes Thunderbird realize they aren't selectable and show them
14645 greyed out, instead of only later giving "not selectable" popup error.
14647 Defaults to @samp{()}.
14650 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
14651 Host allowed in URLAUTH URLs sent by client. "*" allows all.
14652 Defaults to @samp{""}.
14656 Whew! Lots of configuration options. The nice thing about it though is
14657 that GuixSD has a complete interface to Dovecot's configuration
14658 language. This allows not only a nice way to declare configurations,
14659 but also offers reflective capabilities as well: users can write code to
14660 inspect and transform configurations from within Scheme.
14662 However, it could be that you just want to get a @code{dovecot.conf} up
14663 and running. In that case, you can pass an
14664 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
14665 @code{dovecot-service}. As its name indicates, an opaque configuration
14666 does not have easy reflective capabilities.
14668 Available @code{opaque-dovecot-configuration} fields are:
14670 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
14671 The dovecot package.
14674 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
14675 The contents of the @code{dovecot.conf}, as a string.
14678 For example, if your @code{dovecot.conf} is just the empty string, you
14679 could instantiate a dovecot service like this:
14682 (dovecot-service #:config
14683 (opaque-dovecot-configuration
14687 @subsubheading OpenSMTPD Service
14689 @deffn {Scheme Variable} opensmtpd-service-type
14690 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
14691 service, whose value should be an @code{opensmtpd-configuration} object
14692 as in this example:
14695 (service opensmtpd-service-type
14696 (opensmtpd-configuration
14697 (config-file (local-file "./my-smtpd.conf"))))
14701 @deftp {Data Type} opensmtpd-configuration
14702 Data type representing the configuration of opensmtpd.
14705 @item @code{package} (default: @var{opensmtpd})
14706 Package object of the OpenSMTPD SMTP server.
14708 @item @code{config-file} (default: @var{%default-opensmtpd-file})
14709 File-like object of the OpenSMTPD configuration file to use. By default
14710 it listens on the loopback network interface, and allows for mail from
14711 users and daemons on the local machine, as well as permitting email to
14712 remote servers. Run @command{man smtpd.conf} for more information.
14717 @subsubheading Exim Service
14719 @cindex mail transfer agent (MTA)
14720 @cindex MTA (mail transfer agent)
14723 @deffn {Scheme Variable} exim-service-type
14724 This is the type of the @uref{https://exim.org, Exim} mail transfer
14725 agent (MTA), whose value should be an @code{exim-configuration} object
14726 as in this example:
14729 (service exim-service-type
14730 (exim-configuration
14731 (config-file (local-file "./my-exim.conf"))))
14735 In order to use an @code{exim-service-type} service you must also have a
14736 @code{mail-aliases-service-type} service present in your
14737 @code{operating-system} (even if it has no aliases).
14739 @deftp {Data Type} exim-configuration
14740 Data type representing the configuration of exim.
14743 @item @code{package} (default: @var{exim})
14744 Package object of the Exim server.
14746 @item @code{config-file} (default: @code{#f})
14747 File-like object of the Exim configuration file to use. If its value is
14748 @code{#f} then use the default configuration file from the package
14749 provided in @code{package}. The resulting configuration file is loaded
14750 after setting the @code{exim_user} and @code{exim_group} configuration
14756 @subsubheading Mail Aliases Service
14758 @cindex email aliases
14759 @cindex aliases, for email addresses
14761 @deffn {Scheme Variable} mail-aliases-service-type
14762 This is the type of the service which provides @code{/etc/aliases},
14763 specifying how to deliver mail to users on this system.
14766 (service mail-aliases-service-type
14767 '(("postmaster" "bob")
14768 ("bob" "bob@@example.com" "bob@@example2.com")))
14772 The configuration for a @code{mail-aliases-service-type} service is an
14773 association list denoting how to deliver mail that comes to this
14774 system. Each entry is of the form @code{(alias addresses ...)}, with
14775 @code{alias} specifying the local alias and @code{addresses} specifying
14776 where to deliver this user's mail.
14778 The aliases aren't required to exist as users on the local system. In
14779 the above example, there doesn't need to be a @code{postmaster} entry in
14780 the @code{operating-system}'s @code{user-accounts} in order to deliver
14781 the @code{postmaster} mail to @code{bob} (which subsequently would
14782 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
14784 @node Messaging Services
14785 @subsubsection Messaging Services
14790 The @code{(gnu services messaging)} module provides Guix service
14791 definitions for messaging services: currently only Prosody is supported.
14793 @subsubheading Prosody Service
14795 @deffn {Scheme Variable} prosody-service-type
14796 This is the type for the @uref{https://prosody.im, Prosody XMPP
14797 communication server}. Its value must be a @code{prosody-configuration}
14798 record as in this example:
14801 (service prosody-service-type
14802 (prosody-configuration
14803 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
14806 (int-component-configuration
14807 (hostname "conference.example.net")
14809 (mod-muc (mod-muc-configuration)))))
14812 (virtualhost-configuration
14813 (domain "example.net"))))))
14816 See below for details about @code{prosody-configuration}.
14820 By default, Prosody does not need much configuration. Only one
14821 @code{virtualhosts} field is needed: it specifies the domain you wish
14824 You can perform various sanity checks on the generated configuration
14825 with the @code{prosodyctl check} command.
14827 Prosodyctl will also help you to import certificates from the
14828 @code{letsencrypt} directory so that the @code{prosody} user can access
14829 them. See @url{https://prosody.im/doc/letsencrypt}.
14832 prosodyctl --root cert import /etc/letsencrypt/live
14835 The available configuration parameters follow. Each parameter
14836 definition is preceded by its type; for example, @samp{string-list foo}
14837 indicates that the @code{foo} parameter should be specified as a list of
14838 strings. Types starting with @code{maybe-} denote parameters that won't
14839 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
14841 There is also a way to specify the configuration as a string, if you
14842 have an old @code{prosody.cfg.lua} file that you want to port over from
14843 some other system; see the end for more details.
14845 The @code{file-object} type designates either a file-like object
14846 (@pxref{G-Expressions, file-like objects}) or a file name.
14848 @c The following documentation was initially generated by
14849 @c (generate-documentation) in (gnu services messaging). Manually maintained
14850 @c documentation is better, so we shouldn't hesitate to edit below as
14851 @c needed. However if the change you want to make to this documentation
14852 @c can be done in an automated way, it's probably easier to change
14853 @c (generate-documentation) than to make it below and have to deal with
14854 @c the churn as Prosody updates.
14856 Available @code{prosody-configuration} fields are:
14858 @deftypevr {@code{prosody-configuration} parameter} package prosody
14859 The Prosody package.
14862 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
14863 Location of the Prosody data storage directory. See
14864 @url{https://prosody.im/doc/configure}.
14865 Defaults to @samp{"/var/lib/prosody"}.
14868 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
14869 Additional plugin directories. They are searched in all the specified
14870 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
14871 Defaults to @samp{()}.
14874 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
14875 Every virtual host and component needs a certificate so that clients and
14876 servers can securely verify its identity. Prosody will automatically load
14877 certificates/keys from the directory specified here.
14878 Defaults to @samp{"/etc/prosody/certs"}.
14881 @deftypevr {@code{prosody-configuration} parameter} string-list admins
14882 This is a list of accounts that are admins for the server. Note that you
14883 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
14884 @url{https://prosody.im/doc/creating_accounts}.
14885 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
14886 Defaults to @samp{()}.
14889 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
14890 Enable use of libevent for better performance under high load. See
14891 @url{https://prosody.im/doc/libevent}.
14892 Defaults to @samp{#f}.
14895 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
14896 This is the list of modules Prosody will load on startup. It looks for
14897 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
14898 Documentation on modules can be found at:
14899 @url{https://prosody.im/doc/modules}.
14900 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
14903 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
14904 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
14905 should you want to disable them then add them to this list.
14906 Defaults to @samp{()}.
14909 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
14910 Path to a text file where the shared groups are defined. If this path is
14911 empty then @samp{mod_groups} does nothing. See
14912 @url{https://prosody.im/doc/modules/mod_groups}.
14913 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
14916 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
14917 Disable account creation by default, for security. See
14918 @url{https://prosody.im/doc/creating_accounts}.
14919 Defaults to @samp{#f}.
14922 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
14923 These are the SSL/TLS-related settings. Most of them are disabled so to
14924 use Prosody's defaults. If you do not completely understand these options, do
14925 not add them to your config, it is easy to lower the security of your server
14926 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
14928 Available @code{ssl-configuration} fields are:
14930 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
14931 This determines what handshake to use.
14934 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
14935 Path to your private key file.
14938 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
14939 Path to your certificate file.
14942 @deftypevr {@code{ssl-configuration} parameter} file-object capath
14943 Path to directory containing root certificates that you wish Prosody to
14944 trust when verifying the certificates of remote servers.
14945 Defaults to @samp{"/etc/ssl/certs"}.
14948 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
14949 Path to a file containing root certificates that you wish Prosody to trust.
14950 Similar to @code{capath} but with all certificates concatenated together.
14953 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
14954 A list of verification options (these mostly map to OpenSSL's
14955 @code{set_verify()} flags).
14958 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
14959 A list of general options relating to SSL/TLS. These map to OpenSSL's
14960 @code{set_options()}. For a full list of options available in LuaSec, see the
14964 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
14965 How long a chain of certificate authorities to check when looking for a
14966 trusted root certificate.
14969 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
14970 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
14971 clients, and in what order.
14974 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
14975 A path to a file containing parameters for Diffie-Hellman key exchange. You
14976 can create such a file with:
14977 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
14980 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
14981 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
14982 @samp{"secp384r1"}.
14985 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
14986 A list of "extra" verification options.
14989 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
14990 Password for encrypted private keys.
14995 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
14996 Whether to force all client-to-server connections to be encrypted or not.
14997 See @url{https://prosody.im/doc/modules/mod_tls}.
14998 Defaults to @samp{#f}.
15001 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
15002 Set of mechanisms that will never be offered. See
15003 @url{https://prosody.im/doc/modules/mod_saslauth}.
15004 Defaults to @samp{("DIGEST-MD5")}.
15007 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
15008 Whether to force all server-to-server connections to be encrypted or not.
15009 See @url{https://prosody.im/doc/modules/mod_tls}.
15010 Defaults to @samp{#f}.
15013 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
15014 Whether to require encryption and certificate authentication. This
15015 provides ideal security, but requires servers you communicate with to support
15016 encryption AND present valid, trusted certificates. See
15017 @url{https://prosody.im/doc/s2s#security}.
15018 Defaults to @samp{#f}.
15021 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
15022 Many servers don't support encryption or have invalid or self-signed
15023 certificates. You can list domains here that will not be required to
15024 authenticate using certificates. They will be authenticated using DNS. See
15025 @url{https://prosody.im/doc/s2s#security}.
15026 Defaults to @samp{()}.
15029 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
15030 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
15031 valid certificates for some domains by specifying a list here. See
15032 @url{https://prosody.im/doc/s2s#security}.
15033 Defaults to @samp{()}.
15036 @deftypevr {@code{prosody-configuration} parameter} string authentication
15037 Select the authentication backend to use. The default provider stores
15038 passwords in plaintext and uses Prosody's configured data storage to store the
15039 authentication data. If you do not trust your server please see
15040 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
15041 about using the hashed backend. See also
15042 @url{https://prosody.im/doc/authentication}
15043 Defaults to @samp{"internal_plain"}.
15046 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
15047 Set logging options. Advanced logging configuration is not yet supported
15048 by the GuixSD Prosody Service. See @url{https://prosody.im/doc/logging}.
15049 Defaults to @samp{"*syslog"}.
15052 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
15053 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
15054 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
15057 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
15058 Maximum allowed size of the HTTP body (in bytes).
15061 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
15062 Some modules expose their own URL in various ways. This URL is built
15063 from the protocol, host and port used. If Prosody sits behind a proxy, the
15064 public URL will be @code{http-external-url} instead. See
15065 @url{https://prosody.im/doc/http#external_url}.
15068 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
15069 A host in Prosody is a domain on which user accounts can be created. For
15070 example if you want your users to have addresses like
15071 @samp{"john.smith@@example.com"} then you need to add a host
15072 @samp{"example.com"}. All options in this list will apply only to this host.
15074 Note: the name "virtual" host is used in configuration to avoid confusion with
15075 the actual physical host that Prosody is installed on. A single Prosody
15076 instance can serve many domains, each one defined as a VirtualHost entry in
15077 Prosody's configuration. Conversely a server that hosts a single domain would
15078 have just one VirtualHost entry.
15080 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
15082 Available @code{virtualhost-configuration} fields are:
15084 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:
15085 @deftypevr {@code{virtualhost-configuration} parameter} string domain
15086 Domain you wish Prosody to serve.
15091 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
15092 Components are extra services on a server which are available to clients,
15093 usually on a subdomain of the main server (such as
15094 @samp{"mycomponent.example.com"}). Example components might be chatroom
15095 servers, user directories, or gateways to other protocols.
15097 Internal components are implemented with Prosody-specific plugins. To add an
15098 internal component, you simply fill the hostname field, and the plugin you wish
15099 to use for the component.
15101 See @url{https://prosody.im/doc/components}.
15102 Defaults to @samp{()}.
15104 Available @code{int-component-configuration} fields are:
15106 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:
15107 @deftypevr {@code{int-component-configuration} parameter} string hostname
15108 Hostname of the component.
15111 @deftypevr {@code{int-component-configuration} parameter} string plugin
15112 Plugin you wish to use for the component.
15115 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
15116 Multi-user chat (MUC) is Prosody's module for allowing you to create
15117 hosted chatrooms/conferences for XMPP users.
15119 General information on setting up and using multi-user chatrooms can be found
15120 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
15121 which you should read if you are new to XMPP chatrooms.
15123 See also @url{https://prosody.im/doc/modules/mod_muc}.
15125 Available @code{mod-muc-configuration} fields are:
15127 @deftypevr {@code{mod-muc-configuration} parameter} string name
15128 The name to return in service discovery responses.
15129 Defaults to @samp{"Prosody Chatrooms"}.
15132 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
15133 If @samp{#t}, this will only allow admins to create new chatrooms.
15134 Otherwise anyone can create a room. The value @samp{"local"} restricts room
15135 creation to users on the service's parent domain. E.g. @samp{user@@example.com}
15136 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
15137 restricts to service administrators only.
15138 Defaults to @samp{#f}.
15141 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
15142 Maximum number of history messages that will be sent to the member that has
15143 just joined the room.
15144 Defaults to @samp{20}.
15151 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
15152 External components use XEP-0114, which most standalone components
15153 support. To add an external component, you simply fill the hostname field. See
15154 @url{https://prosody.im/doc/components}.
15155 Defaults to @samp{()}.
15157 Available @code{ext-component-configuration} fields are:
15159 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:
15160 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
15161 Password which the component will use to log in.
15164 @deftypevr {@code{ext-component-configuration} parameter} string hostname
15165 Hostname of the component.
15170 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
15171 Port(s) Prosody listens on for component connections.
15172 Defaults to @samp{(5347)}.
15175 @deftypevr {@code{prosody-configuration} parameter} string component-interface
15176 Interface Prosody listens on for component connections.
15177 Defaults to @samp{"127.0.0.1"}.
15180 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
15181 Raw content that will be added to the configuration file.
15184 It could be that you just want to get a @code{prosody.cfg.lua}
15185 up and running. In that case, you can pass an
15186 @code{opaque-prosody-configuration} record as the value of
15187 @code{prosody-service-type}. As its name indicates, an opaque configuration
15188 does not have easy reflective capabilities.
15189 Available @code{opaque-prosody-configuration} fields are:
15191 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
15192 The prosody package.
15195 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
15196 The contents of the @code{prosody.cfg.lua} to use.
15199 For example, if your @code{prosody.cfg.lua} is just the empty
15200 string, you could instantiate a prosody service like this:
15203 (service prosody-service-type
15204 (opaque-prosody-configuration
15205 (prosody.cfg.lua "")))
15208 @c end of Prosody auto-generated documentation
15210 @subsubheading BitlBee Service
15212 @cindex IRC (Internet Relay Chat)
15213 @cindex IRC gateway
15214 @url{http://bitlbee.org,BitlBee} is a gateway that provides an IRC
15215 interface to a variety of messaging protocols such as XMPP.
15217 @defvr {Scheme Variable} bitlbee-service-type
15218 This is the service type for the @url{http://bitlbee.org,BitlBee} IRC
15219 gateway daemon. Its value is a @code{bitlbee-configuration} (see
15222 To have BitlBee listen on port 6667 on localhost, add this line to your
15226 (service bitlbee-service-type)
15230 @deftp {Data Type} bitlbee-configuration
15231 This is the configuration for BitlBee, with the following fields:
15234 @item @code{interface} (default: @code{"127.0.0.1"})
15235 @itemx @code{port} (default: @code{6667})
15236 Listen on the network interface corresponding to the IP address
15237 specified in @var{interface}, on @var{port}.
15239 When @var{interface} is @code{127.0.0.1}, only local clients can
15240 connect; when it is @code{0.0.0.0}, connections can come from any
15241 networking interface.
15243 @item @code{package} (default: @code{bitlbee})
15244 The BitlBee package to use.
15246 @item @code{plugins} (default: @code{'()})
15247 List of plugin packages to use---e.g., @code{bitlbee-discord}.
15249 @item @code{extra-settings} (default: @code{""})
15250 Configuration snippet added as-is to the BitlBee configuration file.
15255 @node Telephony Services
15256 @subsubsection Telephony Services
15258 @cindex Murmur (VoIP server)
15259 @cindex VoIP server
15260 This section describes how to set up and run a Murmur server. Murmur is
15261 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
15264 @deftp {Data Type} murmur-configuration
15265 The service type for the Murmur server. An example configuration can
15269 (service murmur-service-type
15270 (murmur-configuration
15272 "Welcome to this Mumble server running on GuixSD!")
15273 (cert-required? #t) ;disallow text password logins
15274 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
15275 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
15278 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
15279 password with the command that is printed during the activation phase.
15281 It is recommended to register a normal Mumble user account
15282 and grant it admin or moderator rights.
15283 You can use the @code{mumble} client to
15284 login as new normal user, register yourself, and log out.
15285 For the next step login with the name @code{SuperUser} use
15286 the @code{SuperUser} password that you set previously,
15287 and grant your newly registered mumble user administrator or moderator
15288 rights and create some channels.
15290 Available @code{murmur-configuration} fields are:
15293 @item @code{package} (default: @code{mumble})
15294 Package that contains @code{bin/murmurd}.
15296 @item @code{user} (default: @code{"murmur"})
15297 User who will run the Murmur server.
15299 @item @code{group} (default: @code{"murmur"})
15300 Group of the user who will run the murmur server.
15302 @item @code{port} (default: @code{64738})
15303 Port on which the server will listen.
15305 @item @code{welcome-text} (default: @code{""})
15306 Welcome text sent to clients when they connect.
15308 @item @code{server-password} (default: @code{""})
15309 Password the clients have to enter in order to connect.
15311 @item @code{max-users} (default: @code{100})
15312 Maximum of users that can be connected to the server at once.
15314 @item @code{max-user-bandwidth} (default: @code{#f})
15315 Maximum voice traffic a user can send per second.
15317 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
15318 File name of the sqlite database.
15319 The service's user will become the owner of the directory.
15321 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
15322 File name of the log file.
15323 The service's user will become the owner of the directory.
15325 @item @code{autoban-attempts} (default: @code{10})
15326 Maximum number of logins a user can make in @code{autoban-timeframe}
15327 without getting auto banned for @code{autoban-time}.
15329 @item @code{autoban-timeframe} (default: @code{120})
15330 Timeframe for autoban in seconds.
15332 @item @code{autoban-time} (default: @code{300})
15333 Amount of time in seconds for which a client gets banned
15334 when violating the autoban limits.
15336 @item @code{opus-threshold} (default: @code{100})
15337 Percentage of clients that need to support opus
15338 before switching over to opus audio codec.
15340 @item @code{channel-nesting-limit} (default: @code{10})
15341 How deep channels can be nested at maximum.
15343 @item @code{channelname-regex} (default: @code{#f})
15344 A string in from of a Qt regular expression that channel names must conform to.
15346 @item @code{username-regex} (default: @code{#f})
15347 A string in from of a Qt regular expression that user names must conform to.
15349 @item @code{text-message-length} (default: @code{5000})
15350 Maximum size in bytes that a user can send in one text chat message.
15352 @item @code{image-message-length} (default: @code{(* 128 1024)})
15353 Maximum size in bytes that a user can send in one image message.
15355 @item @code{cert-required?} (default: @code{#f})
15356 If it is set to @code{#t} clients that use weak password authentification
15357 will not be accepted. Users must have completed the certificate wizard to join.
15359 @item @code{remember-channel?} (defualt @code{#f})
15360 Should murmur remember the last channel each user was in when they disconnected
15361 and put them into the remembered channel when they rejoin.
15363 @item @code{allow-html?} (default: @code{#f})
15364 Should html be allowed in text messages, user comments, and channel descriptions.
15366 @item @code{allow-ping?} (default: @code{#f})
15367 Setting to true exposes the current user count, the maximum user count, and
15368 the server's maximum bandwidth per client to unauthenticated users. In the
15369 Mumble client, this information is shown in the Connect dialog.
15371 Disabling this setting will prevent public listing of the server.
15373 @item @code{bonjour?} (default: @code{#f})
15374 Should the server advertise itself in the local network through the bonjour protocol.
15376 @item @code{send-version?} (default: @code{#f})
15377 Should the murmur server version be exposed in ping requests.
15379 @item @code{log-days} (default: @code{31})
15380 Murmur also stores logs in the database, which are accessible via RPC.
15381 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
15382 or -1 to disable logging to the database.
15384 @item @code{obfuscate-ips?} (default @code{#t})
15385 Should logged ips be obfuscated to protect the privacy of users.
15387 @item @code{ssl-cert} (default: @code{#f})
15388 File name of the SSL/TLS certificate used for encrypted connections.
15391 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
15393 @item @code{ssl-key} (default: @code{#f})
15394 Filepath to the ssl private key used for encrypted connections.
15396 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
15399 @item @code{ssl-dh-params} (default: @code{#f})
15400 File name of a PEM-encoded file with Diffie-Hellman parameters
15401 for the SSL/TLS encryption. Alternatively you set it to
15402 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
15403 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
15405 @item @code{ssl-ciphers} (default: @code{#f})
15406 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
15409 This option is specified using
15410 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
15411 OpenSSL cipher list notation}.
15413 It is recommended that you try your cipher string using 'openssl ciphers <string>'
15414 before setting it here, to get a feel for which cipher suites you will get.
15415 After setting this option, it is recommend that you inspect your Murmur log
15416 to ensure that Murmur is using the cipher suites that you expected it to.
15418 Note: Changing this option may impact the backwards compatibility of your
15419 Murmur server, and can remove the ability for older Mumble clients to be able
15422 @item @code{public-registration} (default: @code{#f})
15423 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
15425 You can optionally register your server in the public server list that the
15426 @code{mumble} client shows on startup.
15427 You cannot register your server if you have set a @code{server-password},
15428 or set @code{allow-ping} to @code{#f}.
15430 It might take a few hours until it shows up in the public list.
15432 @item @code{file} (default: @code{#f})
15433 Optional alternative override for this configuration.
15437 @deftp {Data Type} murmur-public-registration-configuration
15438 Configuration for public registration of a murmur service.
15442 This is a display name for your server. Not to be confused with the hostname.
15444 @item @code{password}
15445 A password to identify your registration.
15446 Subsequent updates will need the same password. Don't lose your password.
15449 This should be a @code{http://} or @code{https://} link to your web
15452 @item @code{hostname} (default: @code{#f})
15453 By default your server will be listed by its IP address.
15454 If it is set your server will be linked by this host name instead.
15460 @node Monitoring Services
15461 @subsubsection Monitoring Services
15463 @subsubheading Tailon Service
15465 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
15466 viewing and searching log files.
15468 The following example will configure the service with default values.
15469 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
15472 (service tailon-service-type)
15475 The following example customises more of the Tailon configuration,
15476 adding @command{sed} to the list of allowed commands.
15479 (service tailon-service-type
15480 (tailon-configuration
15482 (tailon-configuration-file
15483 (allowed-commands '("tail" "grep" "awk" "sed"))))))
15487 @deftp {Data Type} tailon-configuration
15488 Data type representing the configuration of Tailon.
15489 This type has the following parameters:
15492 @item @code{config-file} (default: @code{(tailon-configuration-file)})
15493 The configuration file to use for Tailon. This can be set to a
15494 @dfn{tailon-configuration-file} record value, or any gexp
15495 (@pxref{G-Expressions}).
15497 For example, to instead use a local file, the @code{local-file} function
15501 (service tailon-service-type
15502 (tailon-configuration
15503 (config-file (local-file "./my-tailon.conf"))))
15506 @item @code{package} (default: @code{tailon})
15507 The tailon package to use.
15512 @deftp {Data Type} tailon-configuration-file
15513 Data type representing the configuration options for Tailon.
15514 This type has the following parameters:
15517 @item @code{files} (default: @code{(list "/var/log")})
15518 List of files to display. The list can include strings for a single file
15519 or directory, or a list, where the first item is the name of a
15520 subsection, and the remaining items are the files or directories in that
15523 @item @code{bind} (default: @code{"localhost:8080"})
15524 Address and port to which Tailon should bind on.
15526 @item @code{relative-root} (default: @code{#f})
15527 URL path to use for Tailon, set to @code{#f} to not use a path.
15529 @item @code{allow-transfers?} (default: @code{#t})
15530 Allow downloading the log files in the web interface.
15532 @item @code{follow-names?} (default: @code{#t})
15533 Allow tailing of not-yet existent files.
15535 @item @code{tail-lines} (default: @code{200})
15536 Number of lines to read initially from each file.
15538 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
15539 Commands to allow running. By default, @code{sed} is disabled.
15541 @item @code{debug?} (default: @code{#f})
15542 Set @code{debug?} to @code{#t} to show debug messages.
15544 @item @code{wrap-lines} (default: @code{#t})
15545 Initial line wrapping state in the web interface. Set to @code{#t} to
15546 initially wrap lines (the default), or to @code{#f} to initially not
15549 @item @code{http-auth} (default: @code{#f})
15550 HTTP authentication type to use. Set to @code{#f} to disable
15551 authentication (the default). Supported values are @code{"digest"} or
15554 @item @code{users} (default: @code{#f})
15555 If HTTP authentication is enabled (see @code{http-auth}), access will be
15556 restricted to the credentials provided here. To configure users, use a
15557 list of pairs, where the first element of the pair is the username, and
15558 the 2nd element of the pair is the password.
15561 (tailon-configuration-file
15562 (http-auth "basic")
15563 (users '(("user1" . "password1")
15564 ("user2" . "password2"))))
15571 @subsubheading Darkstat Service
15573 Darkstat is a packet sniffer that captures network traffic, calculates
15574 statistics about usage, and serves reports over HTTP.
15576 @defvar {Scheme Variable} darkstat-service-type
15577 This is the service type for the
15578 @uref{https://unix4lyfe.org/darkstat/, darkstat}
15579 service, its value must be a @code{darkstat-configuration} record as in
15583 (service darkstat-service-type
15584 (darkstat-configuration
15585 (interface "eno1")))
15589 @deftp {Data Type} darkstat-configuration
15590 Data type representing the configuration of @command{darkstat}.
15593 @item @code{package} (default: @code{darkstat})
15594 The darkstat package to use.
15596 @item @code{interface}
15597 Capture traffic on the specified network interface.
15599 @item @code{port} (default: @code{"667"})
15600 Bind the web interface to the specified port.
15602 @item @code{bind-address} (default: @code{"127.0.0.1"})
15603 Bind the web interface to the specified address.
15605 @item @code{base} (default: @code{"/"})
15606 Specify the path of the base URL. This can be useful if
15607 @command{darkstat} is accessed via a reverse proxy.
15613 @node Kerberos Services
15614 @subsubsection Kerberos Services
15617 The @code{(gnu services kerberos)} module provides services relating to
15618 the authentication protocol @dfn{Kerberos}.
15620 @subsubheading Krb5 Service
15622 Programs using a Kerberos client library normally
15623 expect a configuration file in @file{/etc/krb5.conf}.
15624 This service generates such a file from a definition provided in the
15625 operating system declaration.
15626 It does not cause any daemon to be started.
15628 No ``keytab'' files are provided by this service---you must explicitly create them.
15629 This service is known to work with the MIT client library, @code{mit-krb5}.
15630 Other implementations have not been tested.
15632 @defvr {Scheme Variable} krb5-service-type
15633 A service type for Kerberos 5 clients.
15637 Here is an example of its use:
15639 (service krb5-service-type
15640 (krb5-configuration
15641 (default-realm "EXAMPLE.COM")
15642 (allow-weak-crypto? #t)
15645 (name "EXAMPLE.COM")
15646 (admin-server "groucho.example.com")
15647 (kdc "karl.example.com"))
15650 (admin-server "kerb-admin.argrx.edu")
15651 (kdc "keys.argrx.edu"))))))
15655 This example provides a Kerberos@tie{}5 client configuration which:
15657 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
15658 of which have distinct administration servers and key distribution centers;
15659 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
15660 specified by clients;
15661 @item Accepts services which only support encryption types known to be weak.
15664 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
15665 Only the most commonly used ones are described here.
15666 For a full list, and more detailed explanation of each, see the MIT
15667 @uref{http://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
15671 @deftp {Data Type} krb5-realm
15672 @cindex realm, kerberos
15675 This field is a string identifying the name of the realm.
15676 A common convention is to use the fully qualified DNS name of your organization,
15677 converted to upper case.
15679 @item @code{admin-server}
15680 This field is a string identifying the host where the administration server is
15684 This field is a string identifying the key distribution center
15689 @deftp {Data Type} krb5-configuration
15692 @item @code{allow-weak-crypto?} (default: @code{#f})
15693 If this flag is @code{#t} then services which only offer encryption algorithms
15694 known to be weak will be accepted.
15696 @item @code{default-realm} (default: @code{#f})
15697 This field should be a string identifying the default Kerberos
15698 realm for the client.
15699 You should set this field to the name of your Kerberos realm.
15700 If this value is @code{#f}
15701 then a realm must be specified with every Kerberos principal when invoking programs
15702 such as @command{kinit}.
15704 @item @code{realms}
15705 This should be a non-empty list of @code{krb5-realm} objects, which clients may
15707 Normally, one of them will have a @code{name} field matching the @code{default-realm}
15713 @subsubheading PAM krb5 Service
15716 The @code{pam-krb5} service allows for login authentication and password
15717 management via Kerberos.
15718 You will need this service if you want PAM enabled applications to authenticate
15719 users using Kerberos.
15721 @defvr {Scheme Variable} pam-krb5-service-type
15722 A service type for the Kerberos 5 PAM module.
15725 @deftp {Data Type} pam-krb5-configuration
15726 Data type representing the configuration of the Kerberos 5 PAM module
15727 This type has the following parameters:
15729 @item @code{pam-krb5} (default: @code{pam-krb5})
15730 The pam-krb5 package to use.
15732 @item @code{minimum-uid} (default: @code{1000})
15733 The smallest user ID for which Kerberos authentications should be attempted.
15734 Local accounts with lower values will silently fail to authenticate.
15740 @subsubsection Web Services
15745 The @code{(gnu services web)} module provides the Apache HTTP Server,
15746 the nginx web server, and also a fastcgi wrapper daemon.
15748 @subsubheading Apache HTTP Server
15750 @deffn {Scheme Variable} httpd-service-type
15751 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
15752 (@dfn{httpd}). The value for this service type is a
15753 @code{https-configuration} record.
15755 A simple example configuration is given below.
15758 (service httpd-service-type
15759 (httpd-configuration
15762 (server-name "www.example.com")
15763 (document-root "/srv/http/www.example.com")))))
15766 Other services can also extend the @code{httpd-service-type} to add to
15770 (simple-service 'my-extra-server httpd-service-type
15774 (list (string-append
15775 "ServerName "www.example.com
15776 DocumentRoot \"/srv/http/www.example.com\"")))))
15780 The details for the @code{httpd-configuration}, @code{httpd-module},
15781 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
15784 @deffn {Data Type} httpd-configuration
15785 This data type represents the configuration for the httpd service.
15788 @item @code{package} (default: @code{httpd})
15789 The httpd package to use.
15791 @item @code{pid-file} (default: @code{"/var/run/httpd"})
15792 The pid file used by the shepherd-service.
15794 @item @code{config} (default: @code{(httpd-config-file)})
15795 The configuration file to use with the httpd service. The default value
15796 is a @code{httpd-config-file} record, but this can also be a different
15797 G-expression that generates a file, for example a @code{plain-file}. A
15798 file outside of the store can also be specified through a string.
15803 @deffn {Data Type} httpd-module
15804 This data type represents a module for the httpd service.
15808 The name of the module.
15811 The file for the module. This can be relative to the httpd package being
15812 used, the absolute location of a file, or a G-expression for a file
15813 within the store, for example @code{(file-append mod-wsgi
15814 "/modules/mod_wsgi.so")}.
15819 @deffn {Data Type} httpd-config-file
15820 This data type represents a configuration file for the httpd service.
15823 @item @code{modules} (default: @code{%default-httpd-modules})
15824 The modules to load. Additional modules can be added here, or loaded by
15825 additional configuration.
15827 @item @code{server-root} (default: @code{httpd})
15828 The @code{ServerRoot} in the configuration file, defaults to the httpd
15829 package. Directives including @code{Include} and @code{LoadModule} are
15830 taken as relative to the server root.
15832 @item @code{server-name} (default: @code{#f})
15833 The @code{ServerName} in the configuration file, used to specify the
15834 request scheme, hostname and port that the server uses to identify
15837 This doesn't need to be set in the server config, and can be specifyed
15838 in virtual hosts. The default is @code{#f} to not specify a
15841 @item @code{document-root} (default: @code{"/srv/http"})
15842 The @code{DocumentRoot} from which files will be served.
15844 @item @code{listen} (default: @code{'("80")})
15845 The list of values for the @code{Listen} directives in the config
15846 file. The value should be a list of strings, when each string can
15847 specify the port number to listen on, and optionally the IP address and
15850 @item @code{pid-file} (default: @code{"/var/run/httpd"})
15851 The @code{PidFile} to use. This should match the @code{pid-file} set in
15852 the @code{httpd-configuration} so that the Shepherd service is
15853 configured correctly.
15855 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
15856 The @code{ErrorLog} to which the server will log errors.
15858 @item @code{user} (default: @code{"httpd"})
15859 The @code{User} which the server will answer requests as.
15861 @item @code{group} (default: @code{"httpd"})
15862 The @code{Group} which the server will answer requests as.
15864 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
15865 A flat list of strings and G-expressions which will be added to the end
15866 of the configuration file.
15868 Any values which the service is extended with will be appended to this
15874 @deffn {Data Type} httpd-virtualhost
15875 This data type represents a virtualhost configuration block for the httpd service.
15877 These should be added to the extra-config for the httpd-service.
15880 (simple-service 'my-extra-server httpd-service-type
15884 (list (string-append
15885 "ServerName "www.example.com
15886 DocumentRoot \"/srv/http/www.example.com\"")))))
15890 @item @code{addresses-and-ports}
15891 The addresses and ports for the @code{VirtualHost} directive.
15893 @item @code{contents}
15894 The contents of the @code{VirtualHost} directive, this should be a list
15895 of strings and G-expressions.
15900 @subsubheading NGINX
15902 @deffn {Scheme Variable} nginx-service-type
15903 Service type for the @uref{https://nginx.org/,NGinx} web server. The
15904 value for this service type is a @code{<nginx-configuration>} record.
15906 A simple example configuration is given below.
15909 (service nginx-service-type
15910 (nginx-configuration
15912 (list (nginx-server-configuration
15913 (server-name '("www.example.com"))
15914 (root "/srv/http/www.example.com"))))))
15917 In addition to adding server blocks to the service configuration
15918 directly, this service can be extended by other services to add server
15919 blocks, as in this example:
15922 (simple-service 'my-extra-server nginx-service-type
15923 (list (nginx-server-configuration
15924 (root "/srv/http/extra-website")
15925 (try-files (list "$uri" "$uri/index.html")))))
15929 At startup, @command{nginx} has not yet read its configuration file, so
15930 it uses a default file to log error messages. If it fails to load its
15931 configuration file, that is where error messages are logged. After the
15932 configuration file is loaded, the default error log file changes as per
15933 configuration. In our case, startup error messages can be found in
15934 @file{/var/run/nginx/logs/error.log}, and after configuration in
15935 @file{/var/log/nginx/error.log}. The second location can be changed
15936 with the @var{log-directory} configuration option.
15938 @deffn {Data Type} nginx-configuration
15939 This data type represents the configuration for NGinx. Some
15940 configuration can be done through this and the other provided record
15941 types, or alternatively, a config file can be provided.
15944 @item @code{nginx} (default: @code{nginx})
15945 The nginx package to use.
15947 @item @code{log-directory} (default: @code{"/var/log/nginx"})
15948 The directory to which NGinx will write log files.
15950 @item @code{run-directory} (default: @code{"/var/run/nginx"})
15951 The directory in which NGinx will create a pid file, and write temporary
15954 @item @code{server-blocks} (default: @code{'()})
15955 A list of @dfn{server blocks} to create in the generated configuration
15956 file, the elements should be of type
15957 @code{<nginx-server-configuration>}.
15959 The following example would setup NGinx to serve @code{www.example.com}
15960 from the @code{/srv/http/www.example.com} directory, without using
15963 (service nginx-service-type
15964 (nginx-configuration
15966 (list (nginx-server-configuration
15967 (server-name '("www.example.com"))
15968 (root "/srv/http/www.example.com"))))))
15971 @item @code{upstream-blocks} (default: @code{'()})
15972 A list of @dfn{upstream blocks} to create in the generated configuration
15973 file, the elements should be of type
15974 @code{<nginx-upstream-configuration>}.
15976 Configuring upstreams through the @code{upstream-blocks} can be useful
15977 when combined with @code{locations} in the
15978 @code{<nginx-server-configuration>} records. The following example
15979 creates a server configuration with one location configuration, that
15980 will proxy requests to a upstream configuration, which will handle
15981 requests with two servers.
15986 (nginx-configuration
15988 (list (nginx-server-configuration
15989 (server-name '("www.example.com"))
15990 (root "/srv/http/www.example.com")
15993 (nginx-location-configuration
15995 (body '("proxy_pass http://server-proxy;"))))))))
15997 (list (nginx-upstream-configuration
15998 (name "server-proxy")
15999 (servers (list "server1.example.com"
16000 "server2.example.com")))))))
16003 @item @code{file} (default: @code{#f})
16004 If a configuration @var{file} is provided, this will be used, rather than
16005 generating a configuration file from the provided @code{log-directory},
16006 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
16007 proper operation, these arguments should match what is in @var{file} to ensure
16008 that the directories are created when the service is activated.
16010 This can be useful if you have an existing configuration file, or it's
16011 not possible to do what is required through the other parts of the
16012 nginx-configuration record.
16014 @item @code{server-names-hash-bucket-size} (default: @code{#f})
16015 Bucket size for the server names hash tables, defaults to @code{#f} to
16016 use the size of the processors cache line.
16018 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
16019 Maximum bucket size for the server names hash tables.
16021 @item @code{extra-content} (default: @code{""})
16022 Extra content for the @code{http} block. Should be string or a string
16023 valued G-expression.
16028 @deftp {Data Type} nginx-server-configuration
16029 Data type representing the configuration of an nginx server block.
16030 This type has the following parameters:
16033 @item @code{listen} (default: @code{'("80" "443 ssl")})
16034 Each @code{listen} directive sets the address and port for IP, or the
16035 path for a UNIX-domain socket on which the server will accept requests.
16036 Both address and port, or only address or only port can be specified.
16037 An address may also be a hostname, for example:
16040 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
16043 @item @code{server-name} (default: @code{(list 'default)})
16044 A list of server names this server represents. @code{'default} represents the
16045 default server for connections matching no other server.
16047 @item @code{root} (default: @code{"/srv/http"})
16048 Root of the website nginx will serve.
16050 @item @code{locations} (default: @code{'()})
16051 A list of @dfn{nginx-location-configuration} or
16052 @dfn{nginx-named-location-configuration} records to use within this
16055 @item @code{index} (default: @code{(list "index.html")})
16056 Index files to look for when clients ask for a directory. If it cannot be found,
16057 Nginx will send the list of files in the directory.
16059 @item @code{try-files} (default: @code{'()})
16060 A list of files whose existence is checked in the specified order.
16061 @code{nginx} will use the first file it finds to process the request.
16063 @item @code{ssl-certificate} (default: @code{#f})
16064 Where to find the certificate for secure connections. Set it to @code{#f} if
16065 you don't have a certificate or you don't want to use HTTPS.
16067 @item @code{ssl-certificate-key} (default: @code{#f})
16068 Where to find the private key for secure connections. Set it to @code{#f} if
16069 you don't have a key or you don't want to use HTTPS.
16071 @item @code{server-tokens?} (default: @code{#f})
16072 Whether the server should add its configuration to response.
16074 @item @code{raw-content} (default: @code{'()})
16075 A list of raw lines added to the server block.
16080 @deftp {Data Type} nginx-upstream-configuration
16081 Data type representing the configuration of an nginx @code{upstream}
16082 block. This type has the following parameters:
16086 Name for this group of servers.
16088 @item @code{servers}
16089 Specify the addresses of the servers in the group. The address can be
16090 specified as a IP address (e.g. @samp{127.0.0.1}), domain name
16091 (e.g. @samp{backend1.example.com}) or a path to a UNIX socket using the
16092 prefix @samp{unix:}. For addresses using an IP address or domain name,
16093 the default port is 80, and a different port can be specified
16099 @deftp {Data Type} nginx-location-configuration
16100 Data type representing the configuration of an nginx @code{location}
16101 block. This type has the following parameters:
16105 URI which this location block matches.
16107 @anchor{nginx-location-configuration body}
16109 Body of the location block, specified as a list of strings. This can contain
16111 configuration directives. For example, to pass requests to a upstream
16112 server group defined using an @code{nginx-upstream-configuration} block,
16113 the following directive would be specified in the body @samp{(list "proxy_pass
16114 http://upstream-name;")}.
16119 @deftp {Data Type} nginx-named-location-configuration
16120 Data type representing the configuration of an nginx named location
16121 block. Named location blocks are used for request redirection, and not
16122 used for regular request processing. This type has the following
16127 Name to identify this location block.
16130 @xref{nginx-location-configuration body}, as the body for named location
16131 blocks can be used in a similar way to the
16132 @code{nginx-location-configuration body}. One restriction is that the
16133 body of a named location block cannot contain location blocks.
16140 FastCGI is an interface between the front-end and the back-end of a web
16141 service. It is a somewhat legacy facility; new web services should
16142 generally just talk HTTP between the front-end and the back-end.
16143 However there are a number of back-end services such as PHP or the
16144 optimized HTTP Git repository access that use FastCGI, so we have
16145 support for it in Guix.
16147 To use FastCGI, you configure the front-end web server (e.g., nginx) to
16148 dispatch some subset of its requests to the fastcgi backend, which
16149 listens on a local TCP or UNIX socket. There is an intermediary
16150 @code{fcgiwrap} program that sits between the actual backend process and
16151 the web server. The front-end indicates which backend program to run,
16152 passing that information to the @code{fcgiwrap} process.
16154 @defvr {Scheme Variable} fcgiwrap-service-type
16155 A service type for the @code{fcgiwrap} FastCGI proxy.
16158 @deftp {Data Type} fcgiwrap-configuration
16159 Data type representing the configuration of the @code{fcgiwrap} serice.
16160 This type has the following parameters:
16162 @item @code{package} (default: @code{fcgiwrap})
16163 The fcgiwrap package to use.
16165 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
16166 The socket on which the @code{fcgiwrap} process should listen, as a
16167 string. Valid @var{socket} values include
16168 @code{unix:@var{/path/to/unix/socket}},
16169 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
16170 @code{tcp6:[@var{ipv6_addr}]:port}.
16172 @item @code{user} (default: @code{fcgiwrap})
16173 @itemx @code{group} (default: @code{fcgiwrap})
16174 The user and group names, as strings, under which to run the
16175 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
16176 the user asks for the specific user or group names @code{fcgiwrap} that
16177 the corresponding user and/or group is present on the system.
16179 It is possible to configure a FastCGI-backed web service to pass HTTP
16180 authentication information from the front-end to the back-end, and to
16181 allow @code{fcgiwrap} to run the back-end process as a corresponding
16182 local user. To enable this capability on the back-end., run
16183 @code{fcgiwrap} as the @code{root} user and group. Note that this
16184 capability also has to be configured on the front-end as well.
16189 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
16190 with some additional features useful for sites of any size.
16192 These features include:
16194 @item Adaptive process spawning
16195 @item Basic statistics (similar to Apache's mod_status)
16196 @item Advanced process management with graceful stop/start
16197 @item Ability to start workers with different uid/gid/chroot/environment
16198 and different php.ini (replaces safe_mode)
16199 @item Stdout & stderr logging
16200 @item Emergency restart in case of accidental opcode cache destruction
16201 @item Accelerated upload support
16202 @item Support for a "slowlog"
16203 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
16204 a special function to finish request & flush all data while continuing to do
16205 something time-consuming (video converting, stats processing, etc.)
16209 @defvr {Scheme Variable} php-fpm-service-type
16210 A Service type for @code{php-fpm}.
16213 @deftp {Data Type} php-fpm-configuration
16214 Data Type for php-fpm service configuration.
16216 @item @code{php} (default: @code{php})
16217 The php package to use.
16218 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
16219 The address on which to accept FastCGI requests. Valid syntaxes are:
16221 @item @code{"ip.add.re.ss:port"}
16222 Listen on a TCP socket to a specific address on a specific port.
16223 @item @code{"port"}
16224 Listen on a TCP socket to all addresses on a specific port.
16225 @item @code{"/path/to/unix/socket"}
16226 Listen on a unix socket.
16229 @item @code{user} (default: @code{php-fpm})
16230 User who will own the php worker processes.
16231 @item @code{group} (default: @code{php-fpm})
16232 Group of the worker processes.
16233 @item @code{socket-user} (default: @code{php-fpm})
16234 User who can speak to the php-fpm socket.
16235 @item @code{socket-group} (default: @code{php-fpm})
16236 Group that can speak to the php-fpm socket.
16237 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
16238 The process id of the php-fpm process is written to this file
16239 once the service has started.
16240 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
16241 Log for the php-fpm master process.
16242 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
16243 Detailed settings for the php-fpm process manager.
16246 @item @code{<php-fpm-dynamic-process-manager-configuration>}
16247 @item @code{<php-fpm-static-process-manager-configuration>}
16248 @item @code{<php-fpm-on-demand-process-manager-configuration>}
16250 @item @code{display-errors} (default @code{#f})
16251 Determines whether php errors and warning should be sent to clients
16252 and displayed in their browsers.
16253 This is useful for local php development, but a security risk for public sites,
16254 as error messages can reveal passwords and personal data.
16255 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
16256 This file will log the @code{stderr} outputs of php worker processes.
16257 Can be set to @code{#f} to disable logging.
16258 @item @code{file} (default @code{#f})
16259 An optional override of the whole configuration.
16260 You can use the @code{mixed-text-file} function or an absolute filepath for it.
16264 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
16265 Data Type for the @code{dynamic} php-fpm process manager. With the
16266 @code{dynamic} process manager, spare worker processes are kept around
16267 based on it's configured limits.
16269 @item @code{max-children} (default: @code{5})
16270 Maximum of worker processes.
16271 @item @code{start-servers} (default: @code{2})
16272 How many worker processes should be started on start-up.
16273 @item @code{min-spare-servers} (default: @code{1})
16274 How many spare worker processes should be kept around at minimum.
16275 @item @code{max-spare-servers} (default: @code{3})
16276 How many spare worker processes should be kept around at maximum.
16280 @deftp {Data type} php-fpm-static-process-manager-configuration
16281 Data Type for the @code{static} php-fpm process manager. With the
16282 @code{static} process manager, an unchanging number of worker processes
16285 @item @code{max-children} (default: @code{5})
16286 Maximum of worker processes.
16290 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
16291 Data Type for the @code{on-demand} php-fpm process manager. With the
16292 @code{on-demand} process manager, worker processes are only created as
16295 @item @code{max-children} (default: @code{5})
16296 Maximum of worker processes.
16297 @item @code{process-idle-timeout} (default: @code{10})
16298 The time in seconds after which a process with no requests is killed.
16303 @deffn {Scheme Procedure} nginx-php-fpm-location @
16304 [#:nginx-package nginx] @
16305 [socket (string-append "/var/run/php" @
16306 (version-major (package-version php)) @
16308 A helper function to quickly add php to an @code{nginx-server-configuration}.
16311 A simple services setup for nginx with php can look like this:
16313 (services (cons* (dhcp-client-service)
16314 (service php-fpm-service-type)
16315 (service nginx-service-type
16316 (nginx-server-configuration
16317 (server-name '("example.com"))
16318 (root "/srv/http/")
16320 (list (nginx-php-location)))
16322 (ssl-certificate #f)
16323 (ssl-certificate-key #f)))
16327 @cindex cat-avatar-generator
16328 The cat avatar generator is a simple service to demonstrate the use of php-fpm
16329 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
16330 the hash of a user's email address.
16332 @deffn {Scheme Procedure} cat-avatar-generator-serice @
16333 [#:cache-dir "/var/cache/cat-avatar-generator"] @
16334 [#:package cat-avatar-generator] @
16335 [#:configuration (nginx-server-configuration)]
16336 Returns an nginx-server-configuration that inherits @code{configuration}. It
16337 extends the nginx configuration to add a server block that serves @code{package},
16338 a version of cat-avatar-generator. During execution, cat-avatar-generator will
16339 be able to use @code{cache-dir} as its cache directory.
16342 A simple setup for cat-avatar-generator can look like this:
16344 (services (cons* (cat-avatar-generator-service
16346 (nginx-server-configuration
16347 (server-name '("example.com"))))
16352 @subsubheading Hpcguix-web
16354 @cindex hpcguix-web
16355 The @uref{hpcguix-web, https://github.com/UMCUGenetics/hpcguix-web/}
16356 program is a customizable web interface to browse Guix packages,
16357 initially designed for users of high-performance computing (HPC)
16360 @defvr {Scheme Variable} hpcguix-web-service-type
16361 The service type for @code{hpcguix-web}.
16364 @deftp {Data Type} hpcguix-web-configuration
16365 Data type for the hpcguix-web service configuration.
16369 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
16370 configuration. The main items available in this spec are:
16373 @item @code{title-prefix} (default: @code{"hpcguix | "})
16374 The page title prefix.
16376 @item @code{guix-command} (default: @code{"guix"})
16377 The @command{guix} command.
16379 @item @code{package-filter-proc} (default: @code{(const #t)})
16380 A procedure specifying how to filter packages that are displayed.
16382 @item @code{package-page-extension-proc} (default: @code{(const '())})
16383 Extension package for @code{hpcguix-web}.
16385 @item @code{menu} (default: @code{'()})
16386 Additional entry in page @code{menu}.
16389 See the hpcguix-web repository for a
16390 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
16393 @item @code{package} (default: @code{hpcguix-web})
16394 The hpcguix-web package to use.
16398 A typical hpcguix-web service declaration looks like this:
16401 (service hpcguix-web-service-type
16402 (hpcguix-web-configuration
16404 #~(define site-config
16405 (hpcweb-configuration
16406 (title-prefix "Guix-HPC - ")
16407 (menu '(("/about" "ABOUT"))))))))
16410 @node Certificate Services
16411 @subsubsection Certificate Services
16414 @cindex HTTP, HTTPS
16415 @cindex Let's Encrypt
16416 @cindex TLS certificates
16417 The @code{(gnu services certbot)} module provides a service to
16418 automatically obtain a valid TLS certificate from the Let's Encrypt
16419 certificate authority. These certificates can then be used to serve
16420 content securely over HTTPS or other TLS-based protocols, with the
16421 knowledge that the client will be able to verify the server's
16424 @url{https://letsencrypt.org/, Let's Encrypt} provides the
16425 @code{certbot} tool to automate the certification process. This tool
16426 first securely generates a key on the server. It then makes a request
16427 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
16428 checks that the request originates from the host in question by using a
16429 challenge-response protocol, requiring the server to provide its
16430 response over HTTP. If that protocol completes successfully, the CA
16431 signs the key, resulting in a certificate. That certificate is valid
16432 for a limited period of time, and therefore to continue to provide TLS
16433 services, the server needs to periodically ask the CA to renew its
16436 The certbot service automates this process: the initial key
16437 generation, the initial certification request to the Let's Encrypt
16438 service, the web server challenge/response integration, writing the
16439 certificate to disk, the automated periodic renewals, and the deployment
16440 tasks associated with the renewal (e.g. reloading services, copying keys
16441 with different permissions).
16443 Certbot is run twice a day, at a random minute within the hour. It
16444 won't do anything until your certificates are due for renewal or
16445 revoked, but running it regularly would give your service a chance of
16446 staying online in case a Let's Encrypt-initiated revocation happened for
16449 By using this service, you agree to the ACME Subscriber Agreement, which
16450 can be found there:
16451 @url{https://acme-v01.api.letsencrypt.org/directory}.
16453 @defvr {Scheme Variable} certbot-service-type
16454 A service type for the @code{certbot} Let's Encrypt client. Its value
16455 must be a @code{certbot-configuration} record as in this example:
16458 (define %nginx-deploy-hook
16460 "nginx-deploy-hook"
16461 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
16462 (kill pid SIGHUP))))
16464 (service certbot-service-type
16465 (certbot-configuration
16466 (email "foo@@example.net")
16469 (certificate-configuration
16470 (domains '("example.net" "www.example.net"))
16471 (deploy-hook %nginx-deploy-hook))
16472 (certificate-configuration
16473 (domains '("bar.example.net")))))))
16476 See below for details about @code{certbot-configuration}.
16479 @deftp {Data Type} certbot-configuration
16480 Data type representing the configuration of the @code{certbot} service.
16481 This type has the following parameters:
16484 @item @code{package} (default: @code{certbot})
16485 The certbot package to use.
16487 @item @code{webroot} (default: @code{/var/www})
16488 The directory from which to serve the Let's Encrypt challenge/response
16491 @item @code{certificates} (default: @code{()})
16492 A list of @code{certificates-configuration}s for which to generate
16493 certificates and request signatures. Each certificate has a @code{name}
16494 and several @code{domains}.
16497 Mandatory email used for registration, recovery contact, and important
16498 account notifications.
16500 @item @code{rsa-key-size} (default: @code{2048})
16501 Size of the RSA key.
16503 @item @code{default-location} (default: @i{see below})
16504 The default @code{nginx-location-configuration}. Because @code{certbot}
16505 needs to be able to serve challenges and responses, it needs to be able
16506 to run a web server. It does so by extending the @code{nginx} web
16507 service with an @code{nginx-server-configuration} listening on the
16508 @var{domains} on port 80, and which has a
16509 @code{nginx-location-configuration} for the @code{/.well-known/} URI
16510 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
16511 these nginx configuration data types.
16513 Requests to other URL paths will be matched by the
16514 @code{default-location}, which if present is added to all
16515 @code{nginx-server-configuration}s.
16517 By default, the @code{default-location} will issue a redirect from
16518 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
16519 you to define what to serve on your site via @code{https}.
16521 Pass @code{#f} to not issue a default location.
16525 @deftp {Data Type} certificate-configuration
16526 Data type representing the configuration of a certificate.
16527 This type has the following parameters:
16530 @item @code{name} (default: @i{see below})
16531 This name is used by Certbot for housekeeping and in file paths; it
16532 doesn't affect the content of the certificate itself. To see
16533 certificate names, run @code{certbot certificates}.
16535 Its default is the first provided domain.
16537 @item @code{domains} (default: @code{()})
16538 The first domain provided will be the subject CN of the certificate, and
16539 all domains will be Subject Alternative Names on the certificate.
16541 @item @code{deploy-hook} (default: @code{#f})
16542 Command to be run in a shell once for each successfully issued
16543 certificate. For this command, the shell variable
16544 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
16545 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
16546 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
16547 contain a space-delimited list of renewed certificate domains (for
16548 example, @samp{"example.com www.example.com"}.
16553 For each @code{certificate-configuration}, the certificate is saved to
16554 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
16555 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
16557 @subsubsection DNS Services
16558 @cindex DNS (domain name system)
16559 @cindex domain name system (DNS)
16561 The @code{(gnu services dns)} module provides services related to the
16562 @dfn{domain name system} (DNS). It provides a server service for hosting
16563 an @emph{authoritative} DNS server for multiple zones, slave or master.
16564 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
16565 caching and forwarding DNS server for the LAN, which uses
16566 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
16568 @subsubheading Knot Service
16570 An example configuration of an authoritative server for two zones, one master
16574 (define-zone-entries example.org.zone
16575 ;; Name TTL Class Type Data
16576 ("@@" "" "IN" "A" "127.0.0.1")
16577 ("@@" "" "IN" "NS" "ns")
16578 ("ns" "" "IN" "A" "127.0.0.1"))
16580 (define master-zone
16581 (knot-zone-configuration
16582 (domain "example.org")
16584 (origin "example.org")
16585 (entries example.org.zone)))))
16588 (knot-zone-configuration
16589 (domain "plop.org")
16590 (dnssec-policy "default")
16591 (master (list "plop-master"))))
16593 (define plop-master
16594 (knot-remote-configuration
16596 (address (list "208.76.58.171"))))
16600 (services (cons* (service knot-service-type
16601 (knot-configuration
16602 (remotes (list plop-master))
16603 (zones (list master-zone slave-zone))))
16608 @deffn {Scheme Variable} knot-service-type
16609 This is the type for the Knot DNS server.
16611 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
16612 zones, that is to say domain names you would buy from a registrar. This server
16613 is not a resolver, meaning that it can only resolve names for which it is
16614 authoritative. This server can be configured to serve zones as a master server
16615 or a slave server as a per-zone basis. Slave zones will get their data from
16616 masters, and will serve it as an authoritative server. From the point of view
16617 of a resolver, there is no difference between master and slave.
16619 The following data types are used to configure the Knot DNS server:
16622 @deftp {Data Type} knot-key-configuration
16623 Data type representing a key.
16624 This type has the following parameters:
16627 @item @code{id} (default: @code{""})
16628 An identifier for other configuration fields to refer to this key. IDs must
16629 be unique and must not be empty.
16631 @item @code{algorithm} (default: @code{#f})
16632 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
16633 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
16634 and @code{'hmac-sha512}.
16636 @item @code{secret} (default: @code{""})
16637 The secret key itself.
16642 @deftp {Data Type} knot-acl-configuration
16643 Data type representing an Access Control List (ACL) configuration.
16644 This type has the following parameters:
16647 @item @code{id} (default: @code{""})
16648 An identifier for ether configuration fields to refer to this key. IDs must be
16649 unique and must not be empty.
16651 @item @code{address} (default: @code{'()})
16652 An ordered list of IP addresses, network subnets, or network ranges represented
16653 with strings. The query must match one of them. Empty value means that
16654 address match is not required.
16656 @item @code{key} (default: @code{'()})
16657 An ordered list of references to keys represented with strings. The string
16658 must match a key ID defined in a @code{knot-key-configuration}. No key means
16659 that a key is not require to match that ACL.
16661 @item @code{action} (default: @code{'()})
16662 An ordered list of actions that are permitted or forbidden by this ACL. Possible
16663 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
16664 and @code{'update}.
16666 @item @code{deny?} (default: @code{#f})
16667 When true, the ACL defines restrictions. Listed actions are forbidden. When
16668 false, listed actions are allowed.
16673 @deftp {Data Type} zone-entry
16674 Data type represnting a record entry in a zone file.
16675 This type has the following parameters:
16678 @item @code{name} (default: @code{"@@"})
16679 The name of the record. @code{"@@"} refers to the origin of the zone. Names
16680 are relative to the origin of the zone. For example, in the @code{example.org}
16681 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
16682 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
16683 refers to @code{ns.example.org}.
16685 @item @code{ttl} (default: @code{""})
16686 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
16688 @item @code{class} (default: @code{"IN"})
16689 The class of the record. Knot currently supports only @code{"IN"} and
16690 partially @code{"CH"}.
16692 @item @code{type} (default: @code{"A"})
16693 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
16694 address), NS (Name Server) and MX (Mail eXchange). Many other types are
16697 @item @code{data} (default: @code{""})
16698 The data contained in the record. For instance an IP address associated with
16699 an A record, or a domain name associated with an NS record. Remember that
16700 domain names are relative to the origin unless they end with a dot.
16705 @deftp {Data Type} zone-file
16706 Data type representing the content of a zone file.
16707 This type has the following parameters:
16710 @item @code{entries} (default: @code{'()})
16711 The list of entries. The SOA record is taken care of, so you don't need to
16712 put it in the list of entries. This list should probably contain an entry
16713 for your primary authoritative DNS server. Other than using a list of entries
16714 directly, you can use @code{define-zone-entries} to define a object containing
16715 the list of entries more easily, that you can later pass to the @code{entries}
16716 field of the @code{zone-file}.
16718 @item @code{origin} (default: @code{""})
16719 The name of your zone. This parameter cannot be empty.
16721 @item @code{ns} (default: @code{"ns"})
16722 The domain of your primary authoritative DNS server. The name is relative to
16723 the origin, unless it ends with a dot. It is mandatory that this primary
16724 DNS server corresponds to an NS record in the zone and that it is associated
16725 to an IP address in the list of entries.
16727 @item @code{mail} (default: @code{"hostmaster"})
16728 An email address people can contact you at, as the owner of the zone. This
16729 is translated as @code{<mail>@@<origin>}.
16731 @item @code{serial} (default: @code{1})
16732 The serial number of the zone. As this is used to keep track of changes by
16733 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
16734 Always increment it when you make a change in your zone.
16736 @item @code{refresh} (default: @code{(* 2 24 3600)})
16737 The frequency at which slaves will do a zone transfer. This value is a number
16738 of seconds. It can be computed by multiplications or with
16739 @code{(string->duration)}.
16741 @item @code{retry} (default: @code{(* 15 60)})
16742 The period after which a slave will retry to contact its master when it fails
16743 to do so a first time.
16745 @item @code{expiry} (default: @code{(* 14 24 3600)})
16746 Default TTL of records. Existing records are considered correct for at most
16747 this amount of time. After this period, resolvers will invalidate their cache
16748 and check again that it still exists.
16750 @item @code{nx} (default: @code{3600})
16751 Default TTL of inexistant records. This delay is usually short because you want
16752 your new domains to reach everyone quickly.
16757 @deftp {Data Type} knot-remote-configuration
16758 Data type representing a remote configuration.
16759 This type has the following parameters:
16762 @item @code{id} (default: @code{""})
16763 An identifier for other configuration fields to refer to this remote. IDs must
16764 be unique and must not be empty.
16766 @item @code{address} (default: @code{'()})
16767 An ordered list of destination IP addresses. Addresses are tried in sequence.
16768 An optional port can be given with the @@ separator. For instance:
16769 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
16771 @item @code{via} (default: @code{'()})
16772 An ordered list of source IP addresses. An empty list will have Knot choose
16773 an appropriate source IP. An optional port can be given with the @@ separator.
16774 The default is to choose at random.
16776 @item @code{key} (default: @code{#f})
16777 A reference to a key, that is a string containing the identifier of a key
16778 defined in a @code{knot-key-configuration} field.
16783 @deftp {Data Type} knot-keystore-configuration
16784 Data type representing a keystore to hold dnssec keys.
16785 This type has the following parameters:
16788 @item @code{id} (default: @code{""})
16789 The id of the keystore. It must not be empty.
16791 @item @code{backend} (default: @code{'pem})
16792 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
16794 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
16795 The configuration string of the backend. An example for the PKCS#11 is:
16796 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
16797 For the pem backend, the string reprensents a path in the file system.
16802 @deftp {Data Type} knot-policy-configuration
16803 Data type representing a dnssec policy. Knot DNS is able to automatically
16804 sign your zones. It can either generate and manage your keys automatically or
16805 use keys that you generate.
16807 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
16808 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
16809 zone. In order to be trusted, the KSK needs to be present in the parent zone
16810 (usually a top-level domain). If your registrar supports dnssec, you will
16811 have to send them your KSK's hash so they can add a DS record in their zone.
16812 This is not automated and need to be done each time you change your KSK.
16814 The policy also defines the lifetime of keys. Usually, ZSK can be changed
16815 easily and use weaker cryptographic functions (they use lower parameters) in
16816 order to sign records quickly, so they are changed often. The KSK however
16817 requires manual interaction with the registrar, so they are changed less often
16818 and use stronger parameters because they sign only one record.
16820 This type has the following parameters:
16823 @item @code{id} (default: @code{""})
16824 The id of the policy. It must not be empty.
16826 @item @code{keystore} (default: @code{"default"})
16827 A reference to a keystore, that is a string containing the identifier of a
16828 keystore defined in a @code{knot-keystore-configuration} field. The
16829 @code{"default"} identifier means the default keystore (a kasp database that
16830 was setup by this service).
16832 @item @code{manual?} (default: @code{#f})
16833 Whether the key management is manual or automatic.
16835 @item @code{single-type-signing?} (default: @code{#f})
16836 When @code{#t}, use the Single-Type Signing Scheme.
16838 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
16839 An algorithm of signing keys and issued signatures.
16841 @item @code{ksk-size} (default: @code{256})
16842 The length of the KSK. Note that this value is correct for the default
16843 algorithm, but would be unsecure for other algorithms.
16845 @item @code{zsk-size} (default: @code{256})
16846 The length of the ZSK. Note that this value is correct for the default
16847 algorithm, but would be unsecure for other algorithms.
16849 @item @code{dnskey-ttl} (default: @code{'default})
16850 The TTL value for DNSKEY records added into zone apex. The special
16851 @code{'default} value means same as the zone SOA TTL.
16853 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
16854 The period between ZSK publication and the next rollover initiation.
16856 @item @code{propagation-delay} (default: @code{(* 24 3600)})
16857 An extra delay added for each key rollover step. This value should be high
16858 enough to cover propagation of data from the master server to all slaves.
16860 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
16861 A validity period of newly issued signatures.
16863 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
16864 A period how long before a signature expiration the signature will be refreshed.
16866 @item @code{nsec3?} (default: @code{#f})
16867 When @code{#t}, NSEC3 will be used instead of NSEC.
16869 @item @code{nsec3-iterations} (default: @code{5})
16870 The number of additional times the hashing is performed.
16872 @item @code{nsec3-salt-length} (default: @code{8})
16873 The length of a salt field in octets, which is appended to the original owner
16874 name before hashing.
16876 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
16877 The validity period of newly issued salt field.
16882 @deftp {Data Type} knot-zone-configuration
16883 Data type representing a zone served by Knot.
16884 This type has the following parameters:
16887 @item @code{domain} (default: @code{""})
16888 The domain served by this configuration. It must not be empty.
16890 @item @code{file} (default: @code{""})
16891 The file where this zone is saved. This parameter is ignored by master zones.
16892 Empty means default location that depends on the domain name.
16894 @item @code{zone} (default: @code{(zone-file)})
16895 The content of the zone file. This parameter is ignored by slave zones. It
16896 must contain a zone-file record.
16898 @item @code{master} (default: @code{'()})
16899 A list of master remotes. When empty, this zone is a master. When set, this
16900 zone is a slave. This is a list of remotes identifiers.
16902 @item @code{ddns-master} (default: @code{#f})
16903 The main master. When empty, it defaults to the first master in the list of
16906 @item @code{notify} (default: @code{'()})
16907 A list of slave remote identifiers.
16909 @item @code{acl} (default: @code{'()})
16910 A list of acl identifiers.
16912 @item @code{semantic-checks?} (default: @code{#f})
16913 When set, this adds more semantic checks to the zone.
16915 @item @code{disable-any?} (default: @code{#f})
16916 When set, this forbids queries of the ANY type.
16918 @item @code{zonefile-sync} (default: @code{0})
16919 The delay between a modification in memory and on disk. 0 means immediate
16922 @item @code{serial-policy} (default: @code{'increment})
16923 A policy between @code{'increment} and @code{'unixtime}.
16928 @deftp {Data Type} knot-configuration
16929 Data type representing the Knot configuration.
16930 This type has the following parameters:
16933 @item @code{knot} (default: @code{knot})
16936 @item @code{run-directory} (default: @code{"/var/run/knot"})
16937 The run directory. This directory will be used for pid file and sockets.
16939 @item @code{listen-v4} (default: @code{"0.0.0.0"})
16940 An ip address on which to listen.
16942 @item @code{listen-v6} (default: @code{"::"})
16943 An ip address on which to listen.
16945 @item @code{listen-port} (default: @code{53})
16946 A port on which to listen.
16948 @item @code{keys} (default: @code{'()})
16949 The list of knot-key-configuration used by this configuration.
16951 @item @code{acls} (default: @code{'()})
16952 The list of knot-acl-configuration used by this configuration.
16954 @item @code{remotes} (default: @code{'()})
16955 The list of knot-remote-configuration used by this configuration.
16957 @item @code{zones} (default: @code{'()})
16958 The list of knot-zone-configuration used by this configuration.
16963 @subsubheading Dnsmasq Service
16965 @deffn {Scheme Variable} dnsmasq-service-type
16966 This is the type of the dnsmasq service, whose value should be an
16967 @code{dnsmasq-configuration} object as in this example:
16970 (service dnsmasq-service-type
16971 (dnsmasq-configuration
16973 (servers '("192.168.1.1"))))
16977 @deftp {Data Type} dnsmasq-configuration
16978 Data type representing the configuration of dnsmasq.
16981 @item @code{package} (default: @var{dnsmasq})
16982 Package object of the dnsmasq server.
16984 @item @code{no-hosts?} (default: @code{#f})
16985 When true, don't read the hostnames in /etc/hosts.
16987 @item @code{port} (default: @code{53})
16988 The port to listen on. Setting this to zero completely disables DNS
16989 funtion, leaving only DHCP and/or TFTP.
16991 @item @code{local-service?} (default: @code{#t})
16992 Accept DNS queries only from hosts whose address is on a local subnet,
16993 ie a subnet for which an interface exists on the server.
16995 @item @code{listen-addresses} (default: @code{'()})
16996 Listen on the given IP addresses.
16998 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
16999 The file to read the IP address of the upstream nameservers from.
17001 @item @code{no-resolv?} (default: @code{#f})
17002 When true, don't read @var{resolv-file}.
17004 @item @code{servers} (default: @code{'()})
17005 Specify IP address of upstream servers directly.
17007 @item @code{cache-size} (default: @code{150})
17008 Set the size of dnsmasq's cache. Setting the cache size to zero
17011 @item @code{negative-cache?} (default: @code{#t})
17012 When false, disable negative caching.
17018 @subsubsection VPN Services
17019 @cindex VPN (virtual private network)
17020 @cindex virtual private network (VPN)
17022 The @code{(gnu services vpn)} module provides services related to
17023 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
17024 your machine to connect to a VPN, and a @emph{servire} service for your machine
17025 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
17027 @deffn {Scheme Procedure} openvpn-client-service @
17028 [#:config (openvpn-client-configuration)]
17030 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
17033 @deffn {Scheme Procedure} openvpn-server-service @
17034 [#:config (openvpn-server-configuration)]
17036 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
17038 Both can be run simultaneously.
17041 @c %automatically generated documentation
17043 Available @code{openvpn-client-configuration} fields are:
17045 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
17046 The OpenVPN package.
17050 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
17051 The OpenVPN pid file.
17053 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
17057 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
17058 The protocol (UDP or TCP) used to open a channel between clients and
17061 Defaults to @samp{udp}.
17065 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
17066 The device type used to represent the VPN connection.
17068 Defaults to @samp{tun}.
17072 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
17073 The certificate authority to check connections against.
17075 Defaults to @samp{"/etc/openvpn/ca.crt"}.
17079 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
17080 The certificate of the machine the daemon is running on. It should be
17081 signed by the authority given in @code{ca}.
17083 Defaults to @samp{"/etc/openvpn/client.crt"}.
17087 @deftypevr {@code{openvpn-client-configuration} parameter} string key
17088 The key of the machine the daemon is running on. It must be the key whose
17089 certificate is @code{cert}.
17091 Defaults to @samp{"/etc/openvpn/client.key"}.
17095 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
17096 Whether to use the lzo compression algorithm.
17098 Defaults to @samp{#t}.
17102 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
17103 Don't re-read key files across SIGUSR1 or --ping-restart.
17105 Defaults to @samp{#t}.
17109 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
17110 Don't close and reopen TUN/TAP device or run up/down scripts across
17111 SIGUSR1 or --ping-restart restarts.
17113 Defaults to @samp{#t}.
17117 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
17120 Defaults to @samp{3}.
17124 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
17125 Add an additional layer of HMAC authentication on top of the TLS control
17126 channel to protect against DoS attacks.
17128 Defaults to @samp{#f}.
17132 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
17133 Whether to check the server certificate has server usage extension.
17135 Defaults to @samp{#t}.
17139 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
17140 Bind to a specific local port number.
17142 Defaults to @samp{#f}.
17146 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
17147 Retry resolving server address.
17149 Defaults to @samp{#t}.
17153 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
17154 A list of remote servers to connect to.
17156 Defaults to @samp{()}.
17158 Available @code{openvpn-remote-configuration} fields are:
17160 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
17163 Defaults to @samp{"my-server"}.
17167 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
17168 Port number the server listens to.
17170 Defaults to @samp{1194}.
17175 @c %end of automatic openvpn-client documentation
17177 @c %automatically generated documentation
17179 Available @code{openvpn-server-configuration} fields are:
17181 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
17182 The OpenVPN package.
17186 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
17187 The OpenVPN pid file.
17189 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
17193 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
17194 The protocol (UDP or TCP) used to open a channel between clients and
17197 Defaults to @samp{udp}.
17201 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
17202 The device type used to represent the VPN connection.
17204 Defaults to @samp{tun}.
17208 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
17209 The certificate authority to check connections against.
17211 Defaults to @samp{"/etc/openvpn/ca.crt"}.
17215 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
17216 The certificate of the machine the daemon is running on. It should be
17217 signed by the authority given in @code{ca}.
17219 Defaults to @samp{"/etc/openvpn/client.crt"}.
17223 @deftypevr {@code{openvpn-server-configuration} parameter} string key
17224 The key of the machine the daemon is running on. It must be the key whose
17225 certificate is @code{cert}.
17227 Defaults to @samp{"/etc/openvpn/client.key"}.
17231 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
17232 Whether to use the lzo compression algorithm.
17234 Defaults to @samp{#t}.
17238 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
17239 Don't re-read key files across SIGUSR1 or --ping-restart.
17241 Defaults to @samp{#t}.
17245 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
17246 Don't close and reopen TUN/TAP device or run up/down scripts across
17247 SIGUSR1 or --ping-restart restarts.
17249 Defaults to @samp{#t}.
17253 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
17256 Defaults to @samp{3}.
17260 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
17261 Add an additional layer of HMAC authentication on top of the TLS control
17262 channel to protect against DoS attacks.
17264 Defaults to @samp{#f}.
17268 @deftypevr {@code{openvpn-server-configuration} parameter} number port
17269 Specifies the port number on which the server listens.
17271 Defaults to @samp{1194}.
17275 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
17276 An ip and mask specifying the subnet inside the virtual network.
17278 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
17282 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
17283 A CIDR notation specifying the IPv6 subnet inside the virtual network.
17285 Defaults to @samp{#f}.
17289 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
17290 The Diffie-Hellman parameters file.
17292 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
17296 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
17297 The file that records client IPs.
17299 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
17303 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
17304 When true, the server will act as a gateway for its clients.
17306 Defaults to @samp{#f}.
17310 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
17311 When true, clients are allowed to talk to each other inside the VPN.
17313 Defaults to @samp{#f}.
17317 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
17318 Causes ping-like messages to be sent back and forth over the link so
17319 that each side knows when the other side has gone down. @code{keepalive}
17320 requires a pair. The first element is the period of the ping sending,
17321 and the second element is the timeout before considering the other side
17326 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
17327 The maximum number of clients.
17329 Defaults to @samp{100}.
17333 @deftypevr {@code{openvpn-server-configuration} parameter} string status
17334 The status file. This file shows a small report on current connection.
17335 It is truncated and rewritten every minute.
17337 Defaults to @samp{"/var/run/openvpn/status"}.
17341 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
17342 The list of configuration for some clients.
17344 Defaults to @samp{()}.
17346 Available @code{openvpn-ccd-configuration} fields are:
17348 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
17351 Defaults to @samp{"client"}.
17355 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
17358 Defaults to @samp{#f}.
17362 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
17365 Defaults to @samp{#f}.
17372 @c %end of automatic openvpn-server documentation
17375 @node Network File System
17376 @subsubsection Network File System
17379 The @code{(gnu services nfs)} module provides the following services,
17380 which are most commonly used in relation to mounting or exporting
17381 directory trees as @dfn{network file systems} (NFS).
17383 @subsubheading RPC Bind Service
17386 The RPC Bind service provides a facility to map program numbers into
17387 universal addresses.
17388 Many NFS related services use this facility. Hence it is automatically
17389 started when a dependent service starts.
17391 @defvr {Scheme Variable} rpcbind-service-type
17392 A service type for the RPC portmapper daemon.
17396 @deftp {Data Type} rpcbind-configuration
17397 Data type representing the configuration of the RPC Bind Service.
17398 This type has the following parameters:
17400 @item @code{rpcbind} (default: @code{rpcbind})
17401 The rpcbind package to use.
17403 @item @code{warm-start?} (default: @code{#t})
17404 If this parameter is @code{#t}, then the daemon will read a
17405 state file on startup thus reloading state information saved by a previous
17411 @subsubheading Pipefs Pseudo File System
17415 The pipefs file system is used to transfer NFS related data
17416 between the kernel and user space programs.
17418 @defvr {Scheme Variable} pipefs-service-type
17419 A service type for the pipefs pseudo file system.
17422 @deftp {Data Type} pipefs-configuration
17423 Data type representing the configuration of the pipefs pseudo file system service.
17424 This type has the following parameters:
17426 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
17427 The directory to which the file system is to be attached.
17432 @subsubheading GSS Daemon Service
17435 @cindex global security system
17437 The @dfn{global security system} (GSS) daemon provides strong security for RPC
17439 Before exchanging RPC requests an RPC client must establish a security
17440 context. Typically this is done using the Kerberos command @command{kinit}
17441 or automatically at login time using PAM services (@pxref{Kerberos Services}).
17443 @defvr {Scheme Variable} gss-service-type
17444 A service type for the Global Security System (GSS) daemon.
17447 @deftp {Data Type} gss-configuration
17448 Data type representing the configuration of the GSS daemon service.
17449 This type has the following parameters:
17451 @item @code{nfs-utils} (default: @code{nfs-utils})
17452 The package in which the @command{rpc.gssd} command is to be found.
17454 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
17455 The directory where the pipefs file system is mounted.
17461 @subsubheading IDMAP Daemon Service
17463 @cindex name mapper
17465 The idmap daemon service provides mapping between user IDs and user names.
17466 Typically it is required in order to access file systems mounted via NFSv4.
17468 @defvr {Scheme Variable} idmap-service-type
17469 A service type for the Identity Mapper (IDMAP) daemon.
17472 @deftp {Data Type} idmap-configuration
17473 Data type representing the configuration of the IDMAP daemon service.
17474 This type has the following parameters:
17476 @item @code{nfs-utils} (default: @code{nfs-utils})
17477 The package in which the @command{rpc.idmapd} command is to be found.
17479 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
17480 The directory where the pipefs file system is mounted.
17482 @item @code{domain} (default: @code{#f})
17483 The local NFSv4 domain name.
17484 This must be a string or @code{#f}.
17485 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
17490 @node Continuous Integration
17491 @subsubsection Continuous Integration
17493 @cindex continuous integration
17494 @uref{https://notabug.org/mthl/cuirass, Cuirass} is a continuous
17495 integration tool for Guix. It can be used both for development and for
17496 providing substitutes to others (@pxref{Substitutes}).
17498 The @code{(gnu services cuirass)} module provides the following service.
17500 @defvr {Scheme Procedure} cuirass-service-type
17501 The type of the Cuirass service. Its value must be a
17502 @code{cuirass-configuration} object, as described below.
17505 To add build jobs, you have to set the @code{specifications} field of
17506 the configuration. Here is an example of a service defining a build job
17507 based on a specification that can be found in Cuirass source tree. This
17508 service polls the Guix repository and builds a subset of the Guix
17509 packages, as prescribed in the @file{gnu-system.scm} example spec:
17512 (let ((spec #~((#:name . "guix")
17513 (#:url . "git://git.savannah.gnu.org/guix.git")
17514 (#:load-path . ".")
17515 (#:file . "build-aux/cuirass/gnu-system.scm")
17516 (#:proc . cuirass-jobs)
17517 (#:arguments (subset . "hello"))
17518 (#:branch . "master"))))
17519 (service cuirass-service-type
17520 (cuirass-configuration
17521 (specifications #~(list '#$spec)))))
17524 While information related to build jobs is located directly in the
17525 specifications, global settings for the @command{cuirass} process are
17526 accessible in other @code{cuirass-configuration} fields.
17528 @deftp {Data Type} cuirass-configuration
17529 Data type representing the configuration of Cuirass.
17532 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
17533 Location of the log file.
17535 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
17536 Location of the repository cache.
17538 @item @code{user} (default: @code{"cuirass"})
17539 Owner of the @code{cuirass} process.
17541 @item @code{group} (default: @code{"cuirass"})
17542 Owner's group of the @code{cuirass} process.
17544 @item @code{interval} (default: @code{60})
17545 Number of seconds between the poll of the repositories followed by the
17548 @item @code{database} (default: @code{"/var/run/cuirass/cuirass.db"})
17549 Location of sqlite database which contains the build results and previously
17550 added specifications.
17552 @item @code{port} (default: @code{8081})
17553 Port number used by the HTTP server.
17555 @item --listen=@var{host}
17556 Listen on the network interface for @var{host}. The default is to
17557 accept connections from localhost.
17559 @item @code{specifications} (default: @code{#~'()})
17560 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
17561 where a specification is an association list
17562 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
17563 keys are keywords (@code{#:keyword-example}) as shown in the example
17566 @item @code{use-substitutes?} (default: @code{#f})
17567 This allows using substitutes to avoid building every dependencies of a job
17570 @item @code{one-shot?} (default: @code{#f})
17571 Only evaluate specifications and build derivations once.
17573 @item @code{fallback?} (default: @code{#f})
17574 When substituting a pre-built binary fails, fall back to building
17577 @item @code{load-path} (default: @code{'()})
17578 This allows users to define their own packages and make them visible to
17579 cuirass as in @command{guix build} command.
17581 @item @code{cuirass} (default: @code{cuirass})
17582 The Cuirass package to use.
17586 @node Power Management Services
17587 @subsubsection Power Management Services
17590 @cindex power management with TLP
17591 @subsubheading TLP daemon
17593 The @code{(gnu services pm)} module provides a Guix service definition
17594 for the Linux power management tool TLP.
17596 TLP enables various powersaving modes in userspace and kernel.
17597 Contrary to @code{upower-service}, it is not a passive,
17598 monitoring tool, as it will apply custom settings each time a new power
17599 source is detected. More information can be found at
17600 @uref{http://linrunner.de/en/tlp/tlp.html, TLP home page}.
17602 @deffn {Scheme Variable} tlp-service-type
17603 The service type for the TLP tool. Its value should be a valid
17604 TLP configuration (see below). To use the default settings, simply
17607 (service tlp-service-type)
17611 By default TLP does not need much configuration but most TLP parameters
17612 can be tweaked using @code{tlp-configuration}.
17614 Each parameter definition is preceded by its type; for example,
17615 @samp{boolean foo} indicates that the @code{foo} parameter
17616 should be specified as a boolean. Types starting with
17617 @code{maybe-} denote parameters that won't show up in TLP config file
17618 when their value is @code{'disabled}.
17620 @c The following documentation was initially generated by
17621 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
17622 @c documentation is better, so we shouldn't hesitate to edit below as
17623 @c needed. However if the change you want to make to this documentation
17624 @c can be done in an automated way, it's probably easier to change
17625 @c (generate-documentation) than to make it below and have to deal with
17626 @c the churn as TLP updates.
17628 Available @code{tlp-configuration} fields are:
17630 @deftypevr {@code{tlp-configuration} parameter} package tlp
17635 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
17636 Set to true if you wish to enable TLP.
17638 Defaults to @samp{#t}.
17642 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
17643 Default mode when no power supply can be detected. Alternatives are AC
17646 Defaults to @samp{"AC"}.
17650 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
17651 Number of seconds Linux kernel has to wait after the disk goes idle,
17652 before syncing on AC.
17654 Defaults to @samp{0}.
17658 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
17659 Same as @code{disk-idle-ac} but on BAT mode.
17661 Defaults to @samp{2}.
17665 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
17666 Dirty pages flushing periodicity, expressed in seconds.
17668 Defaults to @samp{15}.
17672 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
17673 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
17675 Defaults to @samp{60}.
17679 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
17680 CPU frequency scaling governor on AC mode. With intel_pstate driver,
17681 alternatives are powersave and performance. With acpi-cpufreq driver,
17682 alternatives are ondemand, powersave, performance and conservative.
17684 Defaults to @samp{disabled}.
17688 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
17689 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
17691 Defaults to @samp{disabled}.
17695 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
17696 Set the min available frequency for the scaling governor on AC.
17698 Defaults to @samp{disabled}.
17702 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
17703 Set the max available frequency for the scaling governor on AC.
17705 Defaults to @samp{disabled}.
17709 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
17710 Set the min available frequency for the scaling governor on BAT.
17712 Defaults to @samp{disabled}.
17716 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
17717 Set the max available frequency for the scaling governor on BAT.
17719 Defaults to @samp{disabled}.
17723 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
17724 Limit the min P-state to control the power dissipation of the CPU, in AC
17725 mode. Values are stated as a percentage of the available performance.
17727 Defaults to @samp{disabled}.
17731 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
17732 Limit the max P-state to control the power dissipation of the CPU, in AC
17733 mode. Values are stated as a percentage of the available performance.
17735 Defaults to @samp{disabled}.
17739 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
17740 Same as @code{cpu-min-perf-on-ac} on BAT mode.
17742 Defaults to @samp{disabled}.
17746 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
17747 Same as @code{cpu-max-perf-on-ac} on BAT mode.
17749 Defaults to @samp{disabled}.
17753 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
17754 Enable CPU turbo boost feature on AC mode.
17756 Defaults to @samp{disabled}.
17760 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
17761 Same as @code{cpu-boost-on-ac?} on BAT mode.
17763 Defaults to @samp{disabled}.
17767 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
17768 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
17769 used under light load conditions.
17771 Defaults to @samp{#f}.
17775 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
17776 Same as @code{sched-powersave-on-ac?} but on BAT mode.
17778 Defaults to @samp{#t}.
17782 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
17783 Enable Linux kernel NMI watchdog.
17785 Defaults to @samp{#f}.
17789 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
17790 For Linux kernels with PHC patch applied, change CPU voltages. An
17791 example value would be @samp{"F:V F:V F:V F:V"}.
17793 Defaults to @samp{disabled}.
17797 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
17798 Set CPU performance versus energy saving policy on AC. Alternatives are
17799 performance, normal, powersave.
17801 Defaults to @samp{"performance"}.
17805 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
17806 Same as @code{energy-perf-policy-ac} but on BAT mode.
17808 Defaults to @samp{"powersave"}.
17812 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
17817 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
17818 Hard disk advanced power management level.
17822 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
17823 Same as @code{disk-apm-bat} but on BAT mode.
17827 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
17828 Hard disk spin down timeout. One value has to be specified for each
17829 declared hard disk.
17831 Defaults to @samp{disabled}.
17835 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
17836 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
17838 Defaults to @samp{disabled}.
17842 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
17843 Select IO scheduler for disk devices. One value has to be specified for
17844 each declared hard disk. Example alternatives are cfq, deadline and
17847 Defaults to @samp{disabled}.
17851 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
17852 SATA aggressive link power management (ALPM) level. Alternatives are
17853 min_power, medium_power, max_performance.
17855 Defaults to @samp{"max_performance"}.
17859 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
17860 Same as @code{sata-linkpwr-ac} but on BAT mode.
17862 Defaults to @samp{"min_power"}.
17866 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
17867 Exclude specified SATA host devices for link power management.
17869 Defaults to @samp{disabled}.
17873 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
17874 Enable Runtime Power Management for AHCI controller and disks on AC
17877 Defaults to @samp{disabled}.
17881 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
17882 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
17884 Defaults to @samp{disabled}.
17888 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
17889 Seconds of inactivity before disk is suspended.
17891 Defaults to @samp{15}.
17895 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
17896 PCI Express Active State Power Management level. Alternatives are
17897 default, performance, powersave.
17899 Defaults to @samp{"performance"}.
17903 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
17904 Same as @code{pcie-aspm-ac} but on BAT mode.
17906 Defaults to @samp{"powersave"}.
17910 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
17911 Radeon graphics clock speed level. Alternatives are low, mid, high,
17914 Defaults to @samp{"high"}.
17918 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
17919 Same as @code{radeon-power-ac} but on BAT mode.
17921 Defaults to @samp{"low"}.
17925 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
17926 Radeon dynamic power management method (DPM). Alternatives are battery,
17929 Defaults to @samp{"performance"}.
17933 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
17934 Same as @code{radeon-dpm-state-ac} but on BAT mode.
17936 Defaults to @samp{"battery"}.
17940 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
17941 Radeon DPM performance level. Alternatives are auto, low, high.
17943 Defaults to @samp{"auto"}.
17947 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
17948 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
17950 Defaults to @samp{"auto"}.
17954 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
17955 Wifi power saving mode.
17957 Defaults to @samp{#f}.
17961 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
17962 Same as @code{wifi-power-ac?} but on BAT mode.
17964 Defaults to @samp{#t}.
17968 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
17969 Disable wake on LAN.
17971 Defaults to @samp{#t}.
17975 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
17976 Timeout duration in seconds before activating audio power saving on
17977 Intel HDA and AC97 devices. A value of 0 disables power saving.
17979 Defaults to @samp{0}.
17983 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
17984 Same as @code{sound-powersave-ac} but on BAT mode.
17986 Defaults to @samp{1}.
17990 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
17991 Disable controller in powersaving mode on Intel HDA devices.
17993 Defaults to @samp{#t}.
17997 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
17998 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
17999 powered on again by releasing (and reinserting) the eject lever or by
18000 pressing the disc eject button on newer models.
18002 Defaults to @samp{#f}.
18006 @deftypevr {@code{tlp-configuration} parameter} string bay-device
18007 Name of the optical drive device to power off.
18009 Defaults to @samp{"sr0"}.
18013 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
18014 Runtime Power Management for PCI(e) bus devices. Alternatives are on
18017 Defaults to @samp{"on"}.
18021 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
18022 Same as @code{runtime-pm-ac} but on BAT mode.
18024 Defaults to @samp{"auto"}.
18028 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
18029 Runtime Power Management for all PCI(e) bus devices, except blacklisted
18032 Defaults to @samp{#t}.
18036 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
18037 Exclude specified PCI(e) device addresses from Runtime Power Management.
18039 Defaults to @samp{disabled}.
18043 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
18044 Exclude PCI(e) devices assigned to the specified drivers from Runtime
18049 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
18050 Enable USB autosuspend feature.
18052 Defaults to @samp{#t}.
18056 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
18057 Exclude specified devices from USB autosuspend.
18059 Defaults to @samp{disabled}.
18063 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
18064 Exclude WWAN devices from USB autosuspend.
18066 Defaults to @samp{#t}.
18070 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
18071 Include specified devices into USB autosuspend, even if they are already
18072 excluded by the driver or via @code{usb-blacklist-wwan?}.
18074 Defaults to @samp{disabled}.
18078 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
18079 Enable USB autosuspend before shutdown.
18081 Defaults to @samp{disabled}.
18085 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
18086 Restore radio device state (bluetooth, wifi, wwan) from previous
18087 shutdown on system startup.
18089 Defaults to @samp{#f}.
18094 @cindex CPU frequency scaling with thermald
18095 @subsubheading Thermald daemon
18097 The @code{(gnu services pm)} module provides an interface to
18098 thermald, a CPU frequency scaling service which helps prevent overheating.
18100 @defvr {Scheme Variable} thermald-service-type
18101 This is the service type for
18102 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
18103 Thermal Daemon, which is responsible for controlling the thermal state
18104 of processors and preventing overheating.
18107 @deftp {Data Type} thermald-configuration
18108 Data type representing the configuration of @code{thermald-service-type}.
18111 @item @code{ignore-cpuid-check?} (default: @code{#f})
18112 Ignore cpuid check for supported CPU models.
18114 @item @code{thermald} (default: @var{thermald})
18115 Package object of thermald.
18120 @node Audio Services
18121 @subsubsection Audio Services
18123 The @code{(gnu services audio)} module provides a service to start MPD
18124 (the Music Player Daemon).
18127 @subsubheading Music Player Daemon
18129 The Music Player Daemon (MPD) is a service that can play music while
18130 being controlled from the local machine or over the network by a variety
18133 The following example shows how one might run @code{mpd} as user
18134 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
18137 (service mpd-service-type
18143 @defvr {Scheme Variable} mpd-service-type
18144 The service type for @command{mpd}
18147 @deftp {Data Type} mpd-configuration
18148 Data type representing the configuration of @command{mpd}.
18151 @item @code{user} (default: @code{"mpd"})
18152 The user to run mpd as.
18154 @item @code{music-dir} (default: @code{"~/Music"})
18155 The directory to scan for music files.
18157 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
18158 The directory to store playlists.
18160 @item @code{port} (default: @code{"6600"})
18161 The port to run mpd on.
18163 @item @code{address} (default: @code{"any"})
18164 The address that mpd will bind to. To use a Unix domain socket,
18165 an absolute path can be specified here.
18170 @node Virtualization Services
18171 @subsubsection Virtualization services
18173 The @code{(gnu services virtualization)} module provides services for
18174 the libvirt and virtlog daemons, as well as other virtualization-related
18177 @subsubheading Libvirt daemon
18178 @code{libvirtd} is the server side daemon component of the libvirt
18179 virtualization management system. This daemon runs on host servers
18180 and performs required management tasks for virtualized guests.
18182 @deffn {Scheme Variable} libvirt-service-type
18183 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
18184 Its value must be a @code{libvirt-configuration}.
18187 (service libvirt-service-type
18188 (libvirt-configuration
18189 (unix-sock-group "libvirt")
18190 (tls-port "16555")))
18194 @c Auto-generated with (generate-libvirt-documentation)
18195 Available @code{libvirt-configuration} fields are:
18197 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
18202 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
18203 Flag listening for secure TLS connections on the public TCP/IP port.
18204 must set @code{listen} for this to have any effect.
18206 It is necessary to setup a CA and issue server certificates before using
18209 Defaults to @samp{#t}.
18213 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
18214 Listen for unencrypted TCP connections on the public TCP/IP port. must
18215 set @code{listen} for this to have any effect.
18217 Using the TCP socket requires SASL authentication by default. Only SASL
18218 mechanisms which support data encryption are allowed. This is
18219 DIGEST_MD5 and GSSAPI (Kerberos5)
18221 Defaults to @samp{#f}.
18225 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
18226 Port for accepting secure TLS connections This can be a port number, or
18229 Defaults to @samp{"16514"}.
18233 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
18234 Port for accepting insecure TCP connections This can be a port number,
18237 Defaults to @samp{"16509"}.
18241 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
18242 IP address or hostname used for client connections.
18244 Defaults to @samp{"0.0.0.0"}.
18248 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
18249 Flag toggling mDNS advertisement of the libvirt service.
18251 Alternatively can disable for all services on a host by stopping the
18254 Defaults to @samp{#f}.
18258 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
18259 Default mDNS advertisement name. This must be unique on the immediate
18262 Defaults to @samp{"Virtualization Host <hostname>"}.
18266 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
18267 UNIX domain socket group ownership. This can be used to allow a
18268 'trusted' set of users access to management capabilities without
18271 Defaults to @samp{"root"}.
18275 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
18276 UNIX socket permissions for the R/O socket. This is used for monitoring
18279 Defaults to @samp{"0777"}.
18283 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
18284 UNIX socket permissions for the R/W socket. Default allows only root.
18285 If PolicyKit is enabled on the socket, the default will change to allow
18286 everyone (eg, 0777)
18288 Defaults to @samp{"0770"}.
18292 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
18293 UNIX socket permissions for the admin socket. Default allows only owner
18294 (root), do not change it unless you are sure to whom you are exposing
18297 Defaults to @samp{"0777"}.
18301 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
18302 The directory in which sockets will be found/created.
18304 Defaults to @samp{"/var/run/libvirt"}.
18308 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
18309 Authentication scheme for UNIX read-only sockets. By default socket
18310 permissions allow anyone to connect
18312 Defaults to @samp{"polkit"}.
18316 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
18317 Authentication scheme for UNIX read-write sockets. By default socket
18318 permissions only allow root. If PolicyKit support was compiled into
18319 libvirt, the default will be to use 'polkit' auth.
18321 Defaults to @samp{"polkit"}.
18325 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
18326 Authentication scheme for TCP sockets. If you don't enable SASL, then
18327 all TCP traffic is cleartext. Don't do this outside of a dev/test
18330 Defaults to @samp{"sasl"}.
18334 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
18335 Authentication scheme for TLS sockets. TLS sockets already have
18336 encryption provided by the TLS layer, and limited authentication is done
18339 It is possible to make use of any SASL authentication mechanism as well,
18340 by using 'sasl' for this option
18342 Defaults to @samp{"none"}.
18346 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
18347 API access control scheme.
18349 By default an authenticated user is allowed access to all APIs. Access
18350 drivers can place restrictions on this.
18352 Defaults to @samp{()}.
18356 @deftypevr {@code{libvirt-configuration} parameter} string key-file
18357 Server key file path. If set to an empty string, then no private key is
18360 Defaults to @samp{""}.
18364 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
18365 Server key file path. If set to an empty string, then no certificate is
18368 Defaults to @samp{""}.
18372 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
18373 Server key file path. If set to an empty string, then no CA certificate
18376 Defaults to @samp{""}.
18380 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
18381 Certificate revocation list path. If set to an empty string, then no
18384 Defaults to @samp{""}.
18388 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
18389 Disable verification of our own server certificates.
18391 When libvirtd starts it performs some sanity checks against its own
18394 Defaults to @samp{#f}.
18398 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
18399 Disable verification of client certificates.
18401 Client certificate verification is the primary authentication mechanism.
18402 Any client which does not present a certificate signed by the CA will be
18405 Defaults to @samp{#f}.
18409 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
18410 Whitelist of allowed x509 Distinguished Name.
18412 Defaults to @samp{()}.
18416 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
18417 Whitelist of allowed SASL usernames. The format for username depends on
18418 the SASL authentication mechanism.
18420 Defaults to @samp{()}.
18424 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
18425 Override the compile time default TLS priority string. The default is
18426 usually "NORMAL" unless overridden at build time. Only set this is it
18427 is desired for libvirt to deviate from the global default settings.
18429 Defaults to @samp{"NORMAL"}.
18433 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
18434 Maximum number of concurrent client connections to allow over all
18437 Defaults to @samp{5000}.
18441 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
18442 Maximum length of queue of connections waiting to be accepted by the
18443 daemon. Note, that some protocols supporting retransmission may obey
18444 this so that a later reattempt at connection succeeds.
18446 Defaults to @samp{1000}.
18450 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
18451 Maximum length of queue of accepted but not yet authenticated clients.
18452 Set this to zero to turn this feature off
18454 Defaults to @samp{20}.
18458 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
18459 Number of workers to start up initially.
18461 Defaults to @samp{5}.
18465 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
18466 Maximum number of worker threads.
18468 If the number of active clients exceeds @code{min-workers}, then more
18469 threads are spawned, up to max_workers limit. Typically you'd want
18470 max_workers to equal maximum number of clients allowed.
18472 Defaults to @samp{20}.
18476 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
18477 Number of priority workers. If all workers from above pool are stuck,
18478 some calls marked as high priority (notably domainDestroy) can be
18479 executed in this pool.
18481 Defaults to @samp{5}.
18485 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
18486 Total global limit on concurrent RPC calls.
18488 Defaults to @samp{20}.
18492 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
18493 Limit on concurrent requests from a single client connection. To avoid
18494 one client monopolizing the server this should be a small fraction of
18495 the global max_requests and max_workers parameter.
18497 Defaults to @samp{5}.
18501 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
18502 Same as @code{min-workers} but for the admin interface.
18504 Defaults to @samp{1}.
18508 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
18509 Same as @code{max-workers} but for the admin interface.
18511 Defaults to @samp{5}.
18515 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
18516 Same as @code{max-clients} but for the admin interface.
18518 Defaults to @samp{5}.
18522 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
18523 Same as @code{max-queued-clients} but for the admin interface.
18525 Defaults to @samp{5}.
18529 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
18530 Same as @code{max-client-requests} but for the admin interface.
18532 Defaults to @samp{5}.
18536 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
18537 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
18539 Defaults to @samp{3}.
18543 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
18546 A filter allows to select a different logging level for a given category
18547 of logs The format for a filter is one of:
18558 where @code{name} is a string which is matched against the category
18559 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
18560 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
18561 be a substring of the full category name, in order to match multiple
18562 similar categories), the optional "+" prefix tells libvirt to log stack
18563 trace for each message matching name, and @code{x} is the minimal level
18564 where matching messages should be logged:
18581 Multiple filters can be defined in a single filters statement, they just
18582 need to be separated by spaces.
18584 Defaults to @samp{"3:remote 4:event"}.
18588 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
18591 An output is one of the places to save logging information The format
18592 for an output can be:
18596 output goes to stderr
18598 @item x:syslog:name
18599 use syslog for the output and use the given name as the ident
18601 @item x:file:file_path
18602 output to a file, with the given filepath
18605 output to journald logging system
18609 In all case the x prefix is the minimal level, acting as a filter
18626 Multiple outputs can be defined, they just need to be separated by
18629 Defaults to @samp{"3:stderr"}.
18633 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
18634 Allows usage of the auditing subsystem to be altered
18638 0: disable all auditing
18641 1: enable auditing, only if enabled on host
18644 2: enable auditing, and exit if disabled on host.
18648 Defaults to @samp{1}.
18652 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
18653 Send audit messages via libvirt logging infrastructure.
18655 Defaults to @samp{#f}.
18659 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
18660 Host UUID. UUID must not have all digits be the same.
18662 Defaults to @samp{""}.
18666 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
18667 Source to read host UUID.
18671 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
18674 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
18678 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
18681 Defaults to @samp{"smbios"}.
18685 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
18686 A keepalive message is sent to a client after @code{keepalive_interval}
18687 seconds of inactivity to check if the client is still responding. If
18688 set to -1, libvirtd will never send keepalive requests; however clients
18689 can still send them and the daemon will send responses.
18691 Defaults to @samp{5}.
18695 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
18696 Maximum number of keepalive messages that are allowed to be sent to the
18697 client without getting any response before the connection is considered
18700 In other words, the connection is automatically closed approximately
18701 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
18702 the last message received from the client. When @code{keepalive-count}
18703 is set to 0, connections will be automatically closed after
18704 @code{keepalive-interval} seconds of inactivity without sending any
18705 keepalive messages.
18707 Defaults to @samp{5}.
18711 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
18712 Same as above but for admin interface.
18714 Defaults to @samp{5}.
18718 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
18719 Same as above but for admin interface.
18721 Defaults to @samp{5}.
18725 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
18726 Timeout for Open vSwitch calls.
18728 The @code{ovs-vsctl} utility is used for the configuration and its
18729 timeout option is set by default to 5 seconds to avoid potential
18730 infinite waits blocking libvirt.
18732 Defaults to @samp{5}.
18736 @c %end of autogenerated docs
18738 @subsubheading Virtlog daemon
18739 The virtlogd service is a server side daemon component of libvirt that is
18740 used to manage logs from virtual machine consoles.
18742 This daemon is not used directly by libvirt client applications, rather it
18743 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
18744 standalone daemon, the main @code{libvirtd} daemon can be restarted without
18745 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
18746 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
18748 @deffn {Scheme Variable} virtlog-service-type
18749 This is the type of the virtlog daemon.
18750 Its value must be a @code{virtlog-configuration}.
18753 (service virtlog-service-type
18754 (virtlog-configuration
18755 (max-clients 1000)))
18759 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
18760 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
18762 Defaults to @samp{3}.
18766 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
18769 A filter allows to select a different logging level for a given category
18770 of logs The format for a filter is one of:
18781 where @code{name} is a string which is matched against the category
18782 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
18783 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
18784 be a substring of the full category name, in order to match multiple
18785 similar categories), the optional "+" prefix tells libvirt to log stack
18786 trace for each message matching name, and @code{x} is the minimal level
18787 where matching messages should be logged:
18804 Multiple filters can be defined in a single filters statement, they just
18805 need to be separated by spaces.
18807 Defaults to @samp{"3:remote 4:event"}.
18811 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
18814 An output is one of the places to save logging information The format
18815 for an output can be:
18819 output goes to stderr
18821 @item x:syslog:name
18822 use syslog for the output and use the given name as the ident
18824 @item x:file:file_path
18825 output to a file, with the given filepath
18828 output to journald logging system
18832 In all case the x prefix is the minimal level, acting as a filter
18849 Multiple outputs can be defined, they just need to be separated by
18852 Defaults to @samp{"3:stderr"}.
18856 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
18857 Maximum number of concurrent client connections to allow over all
18860 Defaults to @samp{1024}.
18864 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
18865 Maximum file size before rolling over.
18867 Defaults to @samp{2MB}
18871 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
18872 Maximum number of backup files to keep.
18874 Defaults to @samp{3}
18878 @subsubheading Transparent Emulation with QEMU
18881 @cindex @code{binfmt_misc}
18882 @code{qemu-binfmt-service-type} provides support for transparent
18883 emulation of program binaries built for different architectures---e.g.,
18884 it allows you to transparently execute an ARMv7 program on an x86_64
18885 machine. It achieves this by combining the @uref{https://www.qemu.org,
18886 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
18888 @defvr {Scheme Variable} qemu-binfmt-service-type
18889 This is the type of the QEMU/binfmt service for transparent emulation.
18890 Its value must be a @code{qemu-binfmt-configuration} object, which
18891 specifies the QEMU package to use as well as the architecture we want to
18895 (service qemu-binfmt-service-type
18896 (qemu-binfmt-configuration
18897 (platforms (lookup-qemu-platforms "arm" "aarch64" "ppc"))))
18900 In this example, we enable transparent emulation for the ARM and aarch64
18901 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
18902 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
18903 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
18906 @deftp {Data Type} qemu-binfmt-configuration
18907 This is the configuration for the @code{qemu-binfmt} service.
18910 @item @code{platforms} (default: @code{'()})
18911 The list of emulated QEMU platforms. Each item must be a @dfn{platform
18912 object} as returned by @code{lookup-qemu-platforms} (see below).
18914 @item @code{guix-support?} (default: @code{#f})
18915 When it is true, QEMU and all its dependencies are added to the build
18916 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
18917 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
18918 handlers to be used within the build environment, which in turn means
18919 that you can transparently build programs for another architecture.
18921 For example, let's suppose you're on an x86_64 machine and you have this
18925 (service qemu-binfmt-service-type
18926 (qemu-binfmt-configuration
18927 (platforms (lookup-qemu-platforms "arm"))
18928 (guix-support? #t)))
18934 guix build -s armhf-linux inkscape
18938 and it will build Inkscape for ARMv7 @emph{as if it were a native
18939 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
18940 if you'd like to test a package build for an architecture you don't have
18943 @item @code{qemu} (default: @code{qemu})
18944 The QEMU package to use.
18948 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
18949 Return the list of QEMU platform objects corresponding to
18950 @var{platforms}@dots{}. @var{platforms} must be a list of strings
18951 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
18952 @code{"mips64el"}, and so on.
18955 @deffn {Scheme Procedure} qemu-platform? @var{obj}
18956 Return true if @var{obj} is a platform object.
18959 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
18960 Return the name of @var{platform}---a string such as @code{"arm"}.
18963 @node Version Control Services
18964 @subsubsection Version Control Services
18966 The @code{(gnu services version-control)} module provides a service to
18967 allow remote access to local Git repositories. There are three options:
18968 the @code{git-daemon-service}, which provides access to repositories via
18969 the @code{git://} unsecured TCP-based protocol, extending the
18970 @code{nginx} web server to proxy some requests to
18971 @code{git-http-backend}, or providing a web interface with
18972 @code{cgit-service-type}.
18974 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
18976 Return a service that runs @command{git daemon}, a simple TCP server to
18977 expose repositories over the Git protocol for anonymous access.
18979 The optional @var{config} argument should be a
18980 @code{<git-daemon-configuration>} object, by default it allows read-only
18981 access to exported@footnote{By creating the magic file
18982 "git-daemon-export-ok" in the repository directory.} repositories under
18987 @deftp {Data Type} git-daemon-configuration
18988 Data type representing the configuration for @code{git-daemon-service}.
18991 @item @code{package} (default: @var{git})
18992 Package object of the Git distributed version control system.
18994 @item @code{export-all?} (default: @var{#f})
18995 Whether to allow access for all Git repositories, even if they do not
18996 have the @file{git-daemon-export-ok} file.
18998 @item @code{base-path} (default: @file{/srv/git})
18999 Whether to remap all the path requests as relative to the given path.
19000 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
19001 then if you later try to pull @code{git://example.com/hello.git}, git
19002 daemon will interpret the path as @code{/srv/git/hello.git}.
19004 @item @code{user-path} (default: @var{#f})
19005 Whether to allow @code{~user} notation to be used in requests. When
19006 specified with empty string, requests to @code{git://host/~alice/foo} is
19007 taken as a request to access @code{foo} repository in the home directory
19008 of user @code{alice}. If @var{(user-path "path")} is specified, the
19009 same request is taken as a request to access @code{path/foo} repository
19010 in the home directory of user @code{alice}.
19012 @item @code{listen} (default: @var{'()})
19013 Whether to listen on specific IP addresses or hostnames, defaults to
19016 @item @code{port} (default: @var{#f})
19017 Whether to listen on an alternative port, which defaults to 9418.
19019 @item @code{whitelist} (default: @var{'()})
19020 If not empty, only allow access to this list of directories.
19022 @item @code{extra-options} (default: @var{'()})
19023 Extra options will be passed to @code{git daemon}, please run
19024 @command{man git-daemon} for more information.
19029 The @code{git://} protocol lacks authentication. When you pull from a
19030 repository fetched via @code{git://}, you don't know that the data you
19031 receive was modified is really coming from the specified host, and you
19032 have your connection is subject to eavesdropping. It's better to use an
19033 authenticated and encrypted transport, such as @code{https}. Although Git allows you
19034 to serve repositories using unsophisticated file-based web servers,
19035 there is a faster protocol implemented by the @code{git-http-backend}
19036 program. This program is the back-end of a proper Git web service. It
19037 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
19038 on running the necessary @code{fcgiwrap} daemon.
19040 Guix has a separate configuration data type for serving Git repositories
19043 @deftp {Data Type} git-http-configuration
19044 Data type representing the configuration for @code{git-http-service}.
19047 @item @code{package} (default: @var{git})
19048 Package object of the Git distributed version control system.
19050 @item @code{git-root} (default: @file{/srv/git})
19051 Directory containing the Git repositories to expose to the world.
19053 @item @code{export-all?} (default: @var{#f})
19054 Whether to expose access for all Git repositories in @var{git-root},
19055 even if they do not have the @file{git-daemon-export-ok} file.
19057 @item @code{uri-path} (default: @file{/git/})
19058 Path prefix for Git access. With the default @code{/git/} prefix, this
19059 will map @code{http://@var{server}/git/@var{repo}.git} to
19060 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
19061 with this prefix are not passed on to this Git instance.
19063 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
19064 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
19069 There is no @code{git-http-service-type}, currently; instead you can
19070 create an @code{nginx-location-configuration} from a
19071 @code{git-http-configuration} and then add that location to a web
19074 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
19075 [config=(git-http-configuration)]
19076 Compute an @code{nginx-location-configuration} that corresponds to the
19077 given Git http configuration. An example nginx service definition to
19078 serve the default @file{/srv/git} over HTTPS might be:
19081 (service nginx-service-type
19082 (nginx-configuration
19085 (nginx-server-configuration
19086 (listen '("443 ssl"))
19087 (server-name "git.my-host.org")
19089 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
19090 (ssl-certificate-key
19091 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
19094 (git-http-nginx-location-configuration
19095 (git-http-configuration (uri-path "/"))))))))))
19098 This example assumes that you are using Let's Encrypt to get your TLS
19099 certificate. @xref{Certificate Services}. The default @code{certbot}
19100 service will redirect all HTTP traffic on @code{git.my-host.org} to
19101 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
19102 system services. @xref{Web Services}.
19105 @subsubheading Cgit Service
19107 @cindex Cgit service
19108 @cindex Git, web interface
19109 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
19110 repositories written in C.
19112 The following example will configure the service with default values.
19113 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
19116 (service cgit-service-type)
19119 The @code{file-object} type designates either a file-like object
19120 (@pxref{G-Expressions, file-like objects}) or a string.
19122 @c %start of fragment
19124 Available @code{cgit-configuration} fields are:
19126 @deftypevr {@code{cgit-configuration} parameter} package package
19131 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
19132 NGINX configuration.
19136 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
19137 Specifies a command which will be invoked to format the content of about
19138 pages (both top-level and for each repository).
19140 Defaults to @samp{""}.
19144 @deftypevr {@code{cgit-configuration} parameter} string agefile
19145 Specifies a path, relative to each repository path, which can be used to
19146 specify the date and time of the youngest commit in the repository.
19148 Defaults to @samp{""}.
19152 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
19153 Specifies a command that will be invoked for authenticating repository
19156 Defaults to @samp{""}.
19160 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
19161 Flag which, when set to @samp{age}, enables date ordering in the branch
19162 ref list, and when set @samp{name} enables ordering by branch name.
19164 Defaults to @samp{"name"}.
19168 @deftypevr {@code{cgit-configuration} parameter} string cache-root
19169 Path used to store the cgit cache entries.
19171 Defaults to @samp{"/var/cache/cgit"}.
19175 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
19176 Number which specifies the time-to-live, in minutes, for the cached
19177 version of repository pages accessed with a fixed SHA1.
19179 Defaults to @samp{-1}.
19183 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
19184 Number which specifies the time-to-live, in minutes, for the cached
19185 version of repository pages accessed without a fixed SHA1.
19187 Defaults to @samp{5}.
19191 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
19192 Number which specifies the time-to-live, in minutes, for the cached
19193 version of the repository summary page.
19195 Defaults to @samp{5}.
19199 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
19200 Number which specifies the time-to-live, in minutes, for the cached
19201 version of the repository index page.
19203 Defaults to @samp{5}.
19207 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
19208 Number which specifies the time-to-live, in minutes, for the result of
19209 scanning a path for Git repositories.
19211 Defaults to @samp{15}.
19215 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
19216 Number which specifies the time-to-live, in minutes, for the cached
19217 version of the repository about page.
19219 Defaults to @samp{15}.
19223 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
19224 Number which specifies the time-to-live, in minutes, for the cached
19225 version of snapshots.
19227 Defaults to @samp{5}.
19231 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
19232 The maximum number of entries in the cgit cache. When set to @samp{0},
19233 caching is disabled.
19235 Defaults to @samp{0}.
19239 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
19240 Sort items in the repo list case sensitively.
19242 Defaults to @samp{#t}.
19246 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
19247 List of common prefixes which, when combined with a repository URL,
19248 generates valid clone URLs for the repository.
19250 Defaults to @samp{()}.
19254 @deftypevr {@code{cgit-configuration} parameter} list clone-url
19255 List of @code{clone-url} templates.
19257 Defaults to @samp{()}.
19261 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
19262 Command which will be invoked to format commit messages.
19264 Defaults to @samp{""}.
19268 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
19269 Flag which, when set to @samp{date}, enables strict date ordering in the
19270 commit log, and when set to @samp{topo} enables strict topological
19273 Defaults to @samp{"git log"}.
19277 @deftypevr {@code{cgit-configuration} parameter} file-object css
19278 URL which specifies the css document to include in all cgit pages.
19280 Defaults to @samp{"/share/cgit/cgit.css"}.
19284 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
19285 Specifies a command which will be invoked to format names and email
19286 address of committers, authors, and taggers, as represented in various
19287 places throughout the cgit interface.
19289 Defaults to @samp{""}.
19293 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
19294 Flag which, when set to @samp{#t}, will make cgit generate a HTML
19295 fragment suitable for embedding in other HTML pages.
19297 Defaults to @samp{#f}.
19301 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
19302 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
19303 commit history graph to the left of the commit messages in the
19304 repository log page.
19306 Defaults to @samp{#f}.
19310 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
19311 Flag which, when set to @samp{#t}, allows all filter settings to be
19312 overridden in repository-specific cgitrc files.
19314 Defaults to @samp{#f}.
19318 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
19319 Flag which, when set to @samp{#t}, allows users to follow a file in the
19322 Defaults to @samp{#f}.
19326 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
19327 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
19330 Defaults to @samp{#t}.
19334 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
19335 Flag which, when set to @samp{#t}, will make cgit generate extra links
19336 "summary", "commit", "tree" for each repo in the repository index.
19338 Defaults to @samp{#f}.
19342 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
19343 Flag which, when set to @samp{#t}, will make cgit display the owner of
19344 each repo in the repository index.
19346 Defaults to @samp{#t}.
19350 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
19351 Flag which, when set to @samp{#t}, will make cgit print the number of
19352 modified files for each commit on the repository log page.
19354 Defaults to @samp{#f}.
19358 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
19359 Flag which, when set to @samp{#t}, will make cgit print the number of
19360 added and removed lines for each commit on the repository log page.
19362 Defaults to @samp{#f}.
19366 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
19367 Flag which, when set to @code{#t}, will make cgit display remote
19368 branches in the summary and refs views.
19370 Defaults to @samp{#f}.
19374 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
19375 Flag which, when set to @code{1}, will make cgit use the subject of the
19376 parent commit as link text when generating links to parent commits in
19379 Defaults to @samp{#f}.
19383 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
19384 Flag which, when set to @samp{#t}, will make cgit use the subject of the
19385 parent commit as link text when generating links to parent commits in
19388 Defaults to @samp{#f}.
19392 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
19393 Flag which, when set to @samp{#t}, will make cgit generate linenumber
19394 links for plaintext blobs printed in the tree view.
19396 Defaults to @samp{#t}.
19400 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
19401 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
19402 set any repo specific settings.
19404 Defaults to @samp{#f}.
19408 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
19409 URL used as link to a shortcut icon for cgit.
19411 Defaults to @samp{"/favicon.ico"}.
19415 @deftypevr {@code{cgit-configuration} parameter} string footer
19416 The content of the file specified with this option will be included
19417 verbatim at the bottom of all pages (i.e. it replaces the standard
19418 "generated by..." message).
19420 Defaults to @samp{""}.
19424 @deftypevr {@code{cgit-configuration} parameter} string head-include
19425 The content of the file specified with this option will be included
19426 verbatim in the HTML HEAD section on all pages.
19428 Defaults to @samp{""}.
19432 @deftypevr {@code{cgit-configuration} parameter} string header
19433 The content of the file specified with this option will be included
19434 verbatim at the top of all pages.
19436 Defaults to @samp{""}.
19440 @deftypevr {@code{cgit-configuration} parameter} file-object include
19441 Name of a configfile to include before the rest of the current config-
19444 Defaults to @samp{""}.
19448 @deftypevr {@code{cgit-configuration} parameter} string index-header
19449 The content of the file specified with this option will be included
19450 verbatim above the repository index.
19452 Defaults to @samp{""}.
19456 @deftypevr {@code{cgit-configuration} parameter} string index-info
19457 The content of the file specified with this option will be included
19458 verbatim below the heading on the repository index page.
19460 Defaults to @samp{""}.
19464 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
19465 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
19466 in the servers timezone.
19468 Defaults to @samp{#f}.
19472 @deftypevr {@code{cgit-configuration} parameter} file-object logo
19473 URL which specifies the source of an image which will be used as a logo
19476 Defaults to @samp{"/share/cgit/cgit.png"}.
19480 @deftypevr {@code{cgit-configuration} parameter} string logo-link
19481 URL loaded when clicking on the cgit logo image.
19483 Defaults to @samp{""}.
19487 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
19488 Command which will be invoked to format the Owner column of the main
19491 Defaults to @samp{""}.
19495 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
19496 Number of items to display in atom feeds view.
19498 Defaults to @samp{10}.
19502 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
19503 Number of entries to list per page in "log" view.
19505 Defaults to @samp{50}.
19509 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
19510 Number of commit message characters to display in "log" view.
19512 Defaults to @samp{80}.
19516 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
19517 Specifies the number of entries to list per page on the repository index
19520 Defaults to @samp{50}.
19524 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
19525 Specifies the maximum number of repo description characters to display
19526 on the repository index page.
19528 Defaults to @samp{80}.
19532 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
19533 Specifies the maximum size of a blob to display HTML for in KBytes.
19535 Defaults to @samp{0}.
19539 @deftypevr {@code{cgit-configuration} parameter} string max-stats
19540 Maximum statistics period. Valid values are @samp{week},@samp{month},
19541 @samp{quarter} and @samp{year}.
19543 Defaults to @samp{""}.
19547 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
19548 Mimetype for the specified filename extension.
19550 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
19551 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
19552 "image/png") (svg "image/svg+xml"))}.
19556 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
19557 Specifies the file to use for automatic mimetype lookup.
19559 Defaults to @samp{""}.
19563 @deftypevr {@code{cgit-configuration} parameter} string module-link
19564 Text which will be used as the formatstring for a hyperlink when a
19565 submodule is printed in a directory listing.
19567 Defaults to @samp{""}.
19571 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
19572 If set to the value @samp{#t} caching will be disabled.
19574 Defaults to @samp{#f}.
19578 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
19579 If set to @samp{#t} showing full author email addresses will be
19582 Defaults to @samp{#f}.
19586 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
19587 Flag which, when set to @samp{#t}, will make cgit omit the standard
19588 header on all pages.
19590 Defaults to @samp{#f}.
19594 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
19595 A list of subdirectories inside of @code{repository-directory}, relative
19596 to it, that should loaded as Git repositories. An empty list means that
19597 all subdirectories will be loaded.
19599 Defaults to @samp{()}.
19603 @deftypevr {@code{cgit-configuration} parameter} file-object readme
19604 Text which will be used as default value for @code{cgit-repo-readme}.
19606 Defaults to @samp{""}.
19610 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
19611 If set to @code{#t} and @code{repository-directory} is enabled, if any
19612 repositories are found with a suffix of @code{.git}, this suffix will be
19613 removed for the URL and name.
19615 Defaults to @samp{#f}.
19619 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
19620 Maximum number of files to consider when detecting renames.
19622 Defaults to @samp{-1}.
19626 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
19627 The way in which repositories in each section are sorted.
19629 Defaults to @samp{""}.
19633 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
19634 Text used as content for the @code{robots} meta-tag.
19636 Defaults to @samp{("noindex" "nofollow")}.
19640 @deftypevr {@code{cgit-configuration} parameter} string root-desc
19641 Text printed below the heading on the repository index page.
19643 Defaults to @samp{"a fast webinterface for the git dscm"}.
19647 @deftypevr {@code{cgit-configuration} parameter} string root-readme
19648 The content of the file specified with this option will be included
19649 verbatim below thef "about" link on the repository index page.
19651 Defaults to @samp{""}.
19655 @deftypevr {@code{cgit-configuration} parameter} string root-title
19656 Text printed as heading on the repository index page.
19658 Defaults to @samp{""}.
19662 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
19663 If set to @samp{#t} and repository-directory is enabled,
19664 repository-directory will recurse into directories whose name starts
19665 with a period. Otherwise, repository-directory will stay away from such
19666 directories, considered as "hidden". Note that this does not apply to
19667 the ".git" directory in non-bare repos.
19669 Defaults to @samp{#f}.
19673 @deftypevr {@code{cgit-configuration} parameter} list snapshots
19674 Text which specifies the default set of snapshot formats that cgit
19675 generates links for.
19677 Defaults to @samp{()}.
19681 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
19682 Name of the directory to scan for repositories (represents
19685 Defaults to @samp{"/srv/git"}.
19689 @deftypevr {@code{cgit-configuration} parameter} string section
19690 The name of the current repository section - all repositories defined
19691 after this option will inherit the current section name.
19693 Defaults to @samp{""}.
19697 @deftypevr {@code{cgit-configuration} parameter} string section-sort
19698 Flag which, when set to @samp{1}, will sort the sections on the
19699 repository listing by name.
19701 Defaults to @samp{""}.
19705 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
19706 A number which, if defined prior to repository-directory, specifies how
19707 many path elements from each repo path to use as a default section name.
19709 Defaults to @samp{0}.
19713 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
19714 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
19717 Defaults to @samp{#f}.
19721 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
19722 Specifies a command which will be invoked to format plaintext blobs in
19725 Defaults to @samp{""}.
19729 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
19730 Specifies the number of branches to display in the repository "summary"
19733 Defaults to @samp{10}.
19737 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
19738 Specifies the number of log entries to display in the repository
19741 Defaults to @samp{10}.
19745 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
19746 Specifies the number of tags to display in the repository "summary"
19749 Defaults to @samp{10}.
19753 @deftypevr {@code{cgit-configuration} parameter} string strict-export
19754 Filename which, if specified, needs to be present within the repository
19755 for cgit to allow access to that repository.
19757 Defaults to @samp{""}.
19761 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
19762 URL which, if specified, will be used as root for all cgit links.
19764 Defaults to @samp{"/"}.
19768 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
19769 A list of @dfn{cgit-repo} records to use with config.
19771 Defaults to @samp{()}.
19773 Available @code{repository-cgit-configuration} fields are:
19775 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
19776 A mask of snapshot formats for this repo that cgit generates links for,
19777 restricted by the global @code{snapshots} setting.
19779 Defaults to @samp{()}.
19783 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
19784 Override the default @code{source-filter}.
19786 Defaults to @samp{""}.
19790 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
19791 The relative URL used to access the repository.
19793 Defaults to @samp{""}.
19797 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
19798 Override the default @code{about-filter}.
19800 Defaults to @samp{""}.
19804 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
19805 Flag which, when set to @samp{age}, enables date ordering in the branch
19806 ref list, and when set to @samp{name} enables ordering by branch name.
19808 Defaults to @samp{""}.
19812 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
19813 A list of URLs which can be used to clone repo.
19815 Defaults to @samp{()}.
19819 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
19820 Override the default @code{commit-filter}.
19822 Defaults to @samp{""}.
19826 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
19827 Flag which, when set to @samp{date}, enables strict date ordering in the
19828 commit log, and when set to @samp{topo} enables strict topological
19831 Defaults to @samp{""}.
19835 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
19836 The name of the default branch for this repository. If no such branch
19837 exists in the repository, the first branch name (when sorted) is used as
19838 default instead. By default branch pointed to by HEAD, or "master" if
19839 there is no suitable HEAD.
19841 Defaults to @samp{""}.
19845 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
19846 The value to show as repository description.
19848 Defaults to @samp{""}.
19852 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
19853 The value to show as repository homepage.
19855 Defaults to @samp{""}.
19859 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
19860 Override the default @code{email-filter}.
19862 Defaults to @samp{""}.
19866 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-commit-graph?
19867 A flag which can be used to disable the global setting
19868 @code{enable-commit-graph?}.
19870 Defaults to @samp{#f}.
19874 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-log-filecount?
19875 A flag which can be used to disable the global setting
19876 @code{enable-log-filecount?}.
19878 Defaults to @samp{#f}.
19882 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-log-linecount?
19883 A flag which can be used to disable the global setting
19884 @code{enable-log-linecount?}.
19886 Defaults to @samp{#f}.
19890 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-remote-branches?
19891 Flag which, when set to @code{#t}, will make cgit display remote
19892 branches in the summary and refs views.
19894 Defaults to @samp{#f}.
19898 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-subject-links?
19899 A flag which can be used to override the global setting
19900 @code{enable-subject-links?}.
19902 Defaults to @samp{#f}.
19906 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-html-serving?
19907 A flag which can be used to override the global setting
19908 @code{enable-html-serving?}.
19910 Defaults to @samp{#f}.
19914 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
19915 Flag which, when set to @code{#t}, hides the repository from the
19918 Defaults to @samp{#f}.
19922 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
19923 Flag which, when set to @samp{#t}, ignores the repository.
19925 Defaults to @samp{#f}.
19929 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
19930 URL which specifies the source of an image which will be used as a logo
19931 on this repo’s pages.
19933 Defaults to @samp{""}.
19937 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
19938 URL loaded when clicking on the cgit logo image.
19940 Defaults to @samp{""}.
19944 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
19945 Override the default @code{owner-filter}.
19947 Defaults to @samp{""}.
19951 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
19952 Text which will be used as the formatstring for a hyperlink when a
19953 submodule is printed in a directory listing. The arguments for the
19954 formatstring are the path and SHA1 of the submodule commit.
19956 Defaults to @samp{""}.
19960 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
19961 Text which will be used as the formatstring for a hyperlink when a
19962 submodule with the specified subdirectory path is printed in a directory
19965 Defaults to @samp{()}.
19969 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
19970 Override the default maximum statistics period.
19972 Defaults to @samp{""}.
19976 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
19977 The value to show as repository name.
19979 Defaults to @samp{""}.
19983 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
19984 A value used to identify the owner of the repository.
19986 Defaults to @samp{""}.
19990 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
19991 An absolute path to the repository directory.
19993 Defaults to @samp{""}.
19997 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
19998 A path (relative to repo) which specifies a file to include verbatim as
19999 the "About" page for this repo.
20001 Defaults to @samp{""}.
20005 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
20006 The name of the current repository section - all repositories defined
20007 after this option will inherit the current section name.
20009 Defaults to @samp{""}.
20013 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
20014 Extra options will be appended to cgitrc file.
20016 Defaults to @samp{()}.
20022 @deftypevr {@code{cgit-configuration} parameter} list extra-options
20023 Extra options will be appended to cgitrc file.
20025 Defaults to @samp{()}.
20030 @c %end of fragment
20032 However, it could be that you just want to get a @code{cgitrc} up and
20033 running. In that case, you can pass an @code{opaque-cgit-configuration}
20034 as a record to @code{cgit-service-type}. As its name indicates, an
20035 opaque configuration does not have easy reflective capabilities.
20037 Available @code{opaque-cgit-configuration} fields are:
20039 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
20043 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
20044 The contents of the @code{cgitrc}, as a string.
20047 For example, if your @code{cgitrc} is just the empty string, you
20048 could instantiate a cgit service like this:
20051 (service cgit-service-type
20052 (opaque-cgit-configuration
20057 @node Game Services
20058 @subsubsection Game Services
20060 @subsubheading The Battle for Wesnoth Service
20062 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
20063 based tactical strategy game, with several single player campaigns, and
20064 multiplayer games (both networked and local).
20066 @defvar {Scheme Variable} wesnothd-service-type
20067 Service type for the wesnothd service. Its value must be a
20068 @code{wesnothd-configuration} object. To run wesnothd in the default
20069 configuration, instantiate it as:
20072 (service wesnothd-service-type)
20076 @deftp {Data Type} wesnothd-configuration
20077 Data type representing the configuration of @command{wesnothd}.
20080 @item @code{package} (default: @code{wesnoth-server})
20081 The wesnoth server package to use.
20083 @item @code{port} (default: @code{15000})
20084 The port to bind the server to.
20088 @node Miscellaneous Services
20089 @subsubsection Miscellaneous Services
20091 @cindex fingerprint
20092 @subsubheading Fingerprint Service
20094 The @code{(gnu services fingerprint)} module provides a DBus service to
20095 read and identify fingerprints via a fingerprint sensor.
20097 @defvr {Scheme Variable} fprintd-service-type
20098 The service type for @command{fprintd}, which provides the fingerprint
20099 reading capability.
20102 (service fprintd-service-type)
20107 @subsubheading System Control Service
20109 The @code{(gnu services sysctl)} provides a service to configure kernel
20110 parameters at boot.
20112 @defvr {Scheme Variable} sysctl-service-type
20113 The service type for @command{sysctl}, which modifies kernel parameters
20114 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
20118 (service sysctl-service-type
20119 (sysctl-configuration
20120 (settings '(("net.ipv4.ip_forward" . "1")))))
20124 @deftp {Data Type} sysctl-configuration
20125 The data type representing the configuration of @command{sysctl}.
20128 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
20129 The @command{sysctl} executable to use.
20131 @item @code{settings} (default: @code{'()})
20132 An association list specifies kernel parameters and their values.
20137 @subsubheading Lirc Service
20139 The @code{(gnu services lirc)} module provides the following service.
20141 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
20142 [#:device #f] [#:driver #f] [#:config-file #f] @
20143 [#:extra-options '()]
20144 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
20145 decodes infrared signals from remote controls.
20147 Optionally, @var{device}, @var{driver} and @var{config-file}
20148 (configuration file name) may be specified. See @command{lircd} manual
20151 Finally, @var{extra-options} is a list of additional command-line options
20152 passed to @command{lircd}.
20156 @subsubheading Spice Service
20158 The @code{(gnu services spice)} module provides the following service.
20160 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
20161 Returns a service that runs @url{http://www.spice-space.org,VDAGENT}, a daemon
20162 that enables sharing the clipboard with a vm and setting the guest display
20163 resolution when the graphical console window resizes.
20166 @subsubsection Dictionary Services
20168 The @code{(gnu services dict)} module provides the following service:
20170 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
20171 Return a service that runs the @command{dicod} daemon, an implementation
20172 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
20174 The optional @var{config} argument specifies the configuration for
20175 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
20176 default it serves the GNU Collaborative International Dictonary of English.
20178 You can add @command{open localhost} to your @file{~/.dico} file to make
20179 @code{localhost} the default server for @command{dico} client
20180 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
20183 @deftp {Data Type} dicod-configuration
20184 Data type representing the configuration of dicod.
20187 @item @code{dico} (default: @var{dico})
20188 Package object of the GNU Dico dictionary server.
20190 @item @code{interfaces} (default: @var{'("localhost")})
20191 This is the list of IP addresses and ports and possibly socket file
20192 names to listen to (@pxref{Server Settings, @code{listen} directive,,
20193 dico, GNU Dico Manual}).
20195 @item @code{handlers} (default: @var{'()})
20196 List of @code{<dicod-handler>} objects denoting handlers (module instances).
20198 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
20199 List of @code{<dicod-database>} objects denoting dictionaries to be served.
20203 @deftp {Data Type} dicod-handler
20204 Data type representing a dictionary handler (module instance).
20208 Name of the handler (module instance).
20210 @item @code{module} (default: @var{#f})
20211 Name of the dicod module of the handler (instance). If it is @code{#f},
20212 the module has the same name as the handler.
20213 (@pxref{Modules,,, dico, GNU Dico Manual}).
20215 @item @code{options}
20216 List of strings or gexps representing the arguments for the module handler
20220 @deftp {Data Type} dicod-database
20221 Data type representing a dictionary database.
20225 Name of the database, will be used in DICT commands.
20227 @item @code{handler}
20228 Name of the dicod handler (module instance) used by this database
20229 (@pxref{Handlers,,, dico, GNU Dico Manual}).
20231 @item @code{complex?} (default: @var{#f})
20232 Whether the database configuration complex. The complex configuration
20233 will need a corresponding @code{<dicod-handler>} object, otherwise not.
20235 @item @code{options}
20236 List of strings or gexps representing the arguments for the database
20237 (@pxref{Databases,,, dico, GNU Dico Manual}).
20241 @defvr {Scheme Variable} %dicod-database:gcide
20242 A @code{<dicod-database>} object serving the GNU Collaborative International
20243 Dictionary of English using the @code{gcide} package.
20246 The following is an example @code{dicod-service} configuration.
20249 (dicod-service #:config
20250 (dicod-configuration
20251 (handlers (list (dicod-handler
20255 (list #~(string-append "dbdir=" #$wordnet))))))
20256 (databases (list (dicod-database
20259 (handler "wordnet")
20260 (options '("database=wn")))
20261 %dicod-database:gcide))))
20264 @node Setuid Programs
20265 @subsection Setuid Programs
20267 @cindex setuid programs
20268 Some programs need to run with ``root'' privileges, even when they are
20269 launched by unprivileged users. A notorious example is the
20270 @command{passwd} program, which users can run to change their
20271 password, and which needs to access the @file{/etc/passwd} and
20272 @file{/etc/shadow} files---something normally restricted to root, for
20273 obvious security reasons. To address that, these executables are
20274 @dfn{setuid-root}, meaning that they always run with root privileges
20275 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
20276 for more info about the setuid mechanism.)
20278 The store itself @emph{cannot} contain setuid programs: that would be a
20279 security issue since any user on the system can write derivations that
20280 populate the store (@pxref{The Store}). Thus, a different mechanism is
20281 used: instead of changing the setuid bit directly on files that are in
20282 the store, we let the system administrator @emph{declare} which programs
20283 should be setuid root.
20285 The @code{setuid-programs} field of an @code{operating-system}
20286 declaration contains a list of G-expressions denoting the names of
20287 programs to be setuid-root (@pxref{Using the Configuration System}).
20288 For instance, the @command{passwd} program, which is part of the Shadow
20289 package, can be designated by this G-expression (@pxref{G-Expressions}):
20292 #~(string-append #$shadow "/bin/passwd")
20295 A default set of setuid programs is defined by the
20296 @code{%setuid-programs} variable of the @code{(gnu system)} module.
20298 @defvr {Scheme Variable} %setuid-programs
20299 A list of G-expressions denoting common programs that are setuid-root.
20301 The list includes commands such as @command{passwd}, @command{ping},
20302 @command{su}, and @command{sudo}.
20305 Under the hood, the actual setuid programs are created in the
20306 @file{/run/setuid-programs} directory at system activation time. The
20307 files in this directory refer to the ``real'' binaries, which are in the
20310 @node X.509 Certificates
20311 @subsection X.509 Certificates
20313 @cindex HTTPS, certificates
20314 @cindex X.509 certificates
20316 Web servers available over HTTPS (that is, HTTP over the transport-layer
20317 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
20318 that the client can then use to @emph{authenticate} the server. To do
20319 that, clients verify that the server's certificate is signed by a
20320 so-called @dfn{certificate authority} (CA). But to verify the CA's
20321 signature, clients must have first acquired the CA's certificate.
20323 Web browsers such as GNU@tie{}IceCat include their own set of CA
20324 certificates, such that they are able to verify CA signatures
20327 However, most other programs that can talk HTTPS---@command{wget},
20328 @command{git}, @command{w3m}, etc.---need to be told where CA
20329 certificates can be found.
20331 @cindex @code{nss-certs}
20332 In GuixSD, this is done by adding a package that provides certificates
20333 to the @code{packages} field of the @code{operating-system} declaration
20334 (@pxref{operating-system Reference}). GuixSD includes one such package,
20335 @code{nss-certs}, which is a set of CA certificates provided as part of
20336 Mozilla's Network Security Services.
20338 Note that it is @emph{not} part of @var{%base-packages}, so you need to
20339 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
20340 most applications and libraries look for certificates by default, points
20341 to the certificates installed globally.
20343 Unprivileged users, including users of Guix on a foreign distro,
20344 can also install their own certificate package in
20345 their profile. A number of environment variables need to be defined so
20346 that applications and libraries know where to find them. Namely, the
20347 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
20348 variables. Some applications add their own environment variables; for
20349 instance, the Git version control system honors the certificate bundle
20350 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
20351 would typically run something like:
20354 $ guix package -i nss-certs
20355 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
20356 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
20357 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
20360 As another example, R requires the @code{CURL_CA_BUNDLE} environment
20361 variable to point to a certificate bundle, so you would have to run
20362 something like this:
20365 $ guix package -i nss-certs
20366 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
20369 For other applications you may want to look up the required environment
20370 variable in the relevant documentation.
20373 @node Name Service Switch
20374 @subsection Name Service Switch
20376 @cindex name service switch
20378 The @code{(gnu system nss)} module provides bindings to the
20379 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
20380 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
20381 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
20382 extended with new ``name'' lookup methods for system databases, which
20383 includes host names, service names, user accounts, and more (@pxref{Name
20384 Service Switch, System Databases and Name Service Switch,, libc, The GNU
20385 C Library Reference Manual}).
20387 The NSS configuration specifies, for each system database, which lookup
20388 method is to be used, and how the various methods are chained
20389 together---for instance, under which circumstances NSS should try the
20390 next method in the list. The NSS configuration is given in the
20391 @code{name-service-switch} field of @code{operating-system} declarations
20392 (@pxref{operating-system Reference, @code{name-service-switch}}).
20395 @cindex .local, host name lookup
20396 As an example, the declaration below configures the NSS to use the
20397 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
20398 back-end}, which supports host name lookups over multicast DNS (mDNS)
20399 for host names ending in @code{.local}:
20402 (name-service-switch
20403 (hosts (list %files ;first, check /etc/hosts
20405 ;; If the above did not succeed, try
20406 ;; with 'mdns_minimal'.
20408 (name "mdns_minimal")
20410 ;; 'mdns_minimal' is authoritative for
20411 ;; '.local'. When it returns "not found",
20412 ;; no need to try the next methods.
20413 (reaction (lookup-specification
20414 (not-found => return))))
20416 ;; Then fall back to DNS.
20420 ;; Finally, try with the "full" 'mdns'.
20425 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
20426 contains this configuration, so you will not have to type it if all you
20427 want is to have @code{.local} host lookup working.
20429 Note that, in this case, in addition to setting the
20430 @code{name-service-switch} of the @code{operating-system} declaration,
20431 you also need to use @code{avahi-service} (@pxref{Networking Services,
20432 @code{avahi-service}}), or @var{%desktop-services}, which includes it
20433 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
20434 to the name service cache daemon (@pxref{Base Services,
20435 @code{nscd-service}}).
20437 For convenience, the following variables provide typical NSS
20440 @defvr {Scheme Variable} %default-nss
20441 This is the default name service switch configuration, a
20442 @code{name-service-switch} object.
20445 @defvr {Scheme Variable} %mdns-host-lookup-nss
20446 This is the name service switch configuration with support for host name
20447 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
20450 The reference for name service switch configuration is given below. It
20451 is a direct mapping of the configuration file format of the C library , so
20452 please refer to the C library manual for more information (@pxref{NSS
20453 Configuration File,,, libc, The GNU C Library Reference Manual}).
20454 Compared to the configuration file format of libc NSS, it has the advantage
20455 not only of adding this warm parenthetic feel that we like, but also
20456 static checks: you will know about syntax errors and typos as soon as you
20457 run @command{guix system}.
20459 @deftp {Data Type} name-service-switch
20461 This is the data type representation the configuration of libc's name
20462 service switch (NSS). Each field below represents one of the supported
20479 The system databases handled by the NSS. Each of these fields must be a
20480 list of @code{<name-service>} objects (see below).
20484 @deftp {Data Type} name-service
20486 This is the data type representing an actual name service and the
20487 associated lookup action.
20491 A string denoting the name service (@pxref{Services in the NSS
20492 configuration,,, libc, The GNU C Library Reference Manual}).
20494 Note that name services listed here must be visible to nscd. This is
20495 achieved by passing the @code{#:name-services} argument to
20496 @code{nscd-service} the list of packages providing the needed name
20497 services (@pxref{Base Services, @code{nscd-service}}).
20500 An action specified using the @code{lookup-specification} macro
20501 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
20502 Reference Manual}). For example:
20505 (lookup-specification (unavailable => continue)
20506 (success => return))
20511 @node Initial RAM Disk
20512 @subsection Initial RAM Disk
20515 @cindex initial RAM disk
20516 For bootstrapping purposes, the Linux-Libre kernel is passed an
20517 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
20518 root file system as well as an initialization script. The latter is
20519 responsible for mounting the real root file system, and for loading any
20520 kernel modules that may be needed to achieve that.
20522 The @code{initrd-modules} field of an @code{operating-system}
20523 declaration allows you to specify Linux-libre kernel modules that must
20524 be available in the initrd. In particular, this is where you would list
20525 modules needed to actually drive the hard disk where your root partition
20526 is---although the default value of @code{initrd-modules} should cover
20527 most use cases. For example, assuming you need the @code{megaraid_sas}
20528 module in addition to the default modules to be able to access your root
20529 file system, you would write:
20534 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
20537 @defvr {Scheme Variable} %base-initrd-modules
20538 This is the list of kernel modules included in the initrd by default.
20541 Furthermore, if you need lower-level customization, the @code{initrd}
20542 field of an @code{operating-system} declaration allows
20543 you to specify which initrd you would like to use. The @code{(gnu
20544 system linux-initrd)} module provides three ways to build an initrd: the
20545 high-level @code{base-initrd} procedure and the low-level
20546 @code{raw-initrd} and @code{expression->initrd} procedures.
20548 The @code{base-initrd} procedure is intended to cover most common uses.
20549 For example, if you want to add a bunch of kernel modules to be loaded
20550 at boot time, you can define the @code{initrd} field of the operating
20551 system declaration like this:
20554 (initrd (lambda (file-systems . rest)
20555 ;; Create a standard initrd but set up networking
20556 ;; with the parameters QEMU expects by default.
20557 (apply base-initrd file-systems
20558 #:qemu-networking? #t
20562 The @code{base-initrd} procedure also handles common use cases that
20563 involves using the system as a QEMU guest, or as a ``live'' system with
20564 volatile root file system.
20566 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
20567 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
20568 such as trying to guess which kernel modules and packages should be included
20569 to the initrd. An example use of @code{raw-initrd} is when a user has
20570 a custom Linux kernel configuration and default kernel modules included by
20571 @code{base-initrd} are not available.
20573 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
20574 honors several options passed on the Linux kernel command line
20575 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
20576 @code{-append} option of QEMU), notably:
20579 @item --load=@var{boot}
20580 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
20581 program, once it has mounted the root file system.
20583 GuixSD uses this option to yield control to a boot program that runs the
20584 service activation programs and then spawns the GNU@tie{}Shepherd, the
20585 initialization system.
20587 @item --root=@var{root}
20588 Mount @var{root} as the root file system. @var{root} can be a
20589 device name like @code{/dev/sda1}, a file system label, or a file system
20592 @item --system=@var{system}
20593 Have @file{/run/booted-system} and @file{/run/current-system} point to
20596 @item modprobe.blacklist=@var{modules}@dots{}
20597 @cindex module, black-listing
20598 @cindex black list, of kernel modules
20599 Instruct the initial RAM disk as well as the @command{modprobe} command
20600 (from the kmod package) to refuse to load @var{modules}. @var{modules}
20601 must be a comma-separated list of module names---e.g.,
20602 @code{usbkbd,9pnet}.
20605 Start a read-eval-print loop (REPL) from the initial RAM disk before it
20606 tries to load kernel modules and to mount the root file system. Our
20607 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
20608 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
20609 Manual}, for more information on Guile's REPL.
20613 Now that you know all the features that initial RAM disks produced by
20614 @code{base-initrd} and @code{raw-initrd} provide,
20615 here is how to use it and customize it further.
20618 @cindex initial RAM disk
20619 @deffn {Monadic Procedure} raw-initrd @var{file-systems} @
20620 [#:linux-modules '()] [#:mapped-devices '()] @
20621 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
20622 Return a monadic derivation that builds a raw initrd. @var{file-systems} is
20623 a list of file systems to be mounted by the initrd, possibly in addition to
20624 the root file system specified on the kernel command line via @code{--root}.
20625 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
20626 @var{mapped-devices} is a list of device mappings to realize before
20627 @var{file-systems} are mounted (@pxref{Mapped Devices}).
20628 @var{helper-packages} is a list of packages to be copied in the initrd. It may
20629 include @code{e2fsck/static} or other packages needed by the initrd to check
20630 the root file system.
20632 When @var{qemu-networking?} is true, set up networking with the standard QEMU
20633 parameters. When @var{virtio?} is true, load additional modules so that the
20634 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
20636 When @var{volatile-root?} is true, the root file system is writable but any changes
20640 @deffn {Monadic Procedure} base-initrd @var{file-systems} @
20641 [#:mapped-devices '()] [#:qemu-networking? #f] [#:volatile-root? #f]@
20642 [#:linux-modules '()]
20643 Return a monadic derivation that builds a generic initrd, with kernel
20644 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
20645 mounted by the initrd, possibly in addition to the root file system specified
20646 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
20647 mappings to realize before @var{file-systems} are mounted.
20649 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
20651 The initrd is automatically populated with all the kernel modules necessary
20652 for @var{file-systems} and for the given options. Additional kernel
20653 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
20654 loaded at boot time in the order in which they appear.
20657 Needless to say, the initrds we produce and use embed a
20658 statically-linked Guile, and the initialization program is a Guile
20659 program. That gives a lot of flexibility. The
20660 @code{expression->initrd} procedure builds such an initrd, given the
20661 program to run in that initrd.
20663 @deffn {Monadic Procedure} expression->initrd @var{exp} @
20664 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
20665 Return a derivation that builds a Linux initrd (a gzipped cpio archive)
20666 containing @var{guile} and that evaluates @var{exp}, a G-expression,
20667 upon booting. All the derivations referenced by @var{exp} are
20668 automatically copied to the initrd.
20671 @node Bootloader Configuration
20672 @subsection Bootloader Configuration
20675 @cindex boot loader
20677 The operating system supports multiple bootloaders. The bootloader is
20678 configured using @code{bootloader-configuration} declaration. All the
20679 fields of this structure are bootloader agnostic except for one field,
20680 @code{bootloader} that indicates the bootloader to be configured and
20683 Some of the bootloaders do not honor every field of
20684 @code{bootloader-configuration}. For instance, the extlinux
20685 bootloader does not support themes and thus ignores the @code{theme}
20688 @deftp {Data Type} bootloader-configuration
20689 The type of a bootloader configuration declaration.
20693 @item @code{bootloader}
20694 @cindex EFI, bootloader
20695 @cindex UEFI, bootloader
20696 @cindex BIOS, bootloader
20697 The bootloader to use, as a @code{bootloader} object. For now
20698 @code{grub-bootloader}, @code{grub-efi-bootloader},
20699 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
20700 @code{grub-efi-bootloader} allows to boot on modern systems using the
20701 @dfn{Unified Extensible Firmware Interface} (UEFI).
20703 Available bootloaders are described in @code{(gnu bootloader @dots{})}
20706 @item @code{target}
20707 This is a string denoting the target onto which to install the
20708 bootloader. The exact interpretation depends on the bootloader in
20709 question; for @code{grub-bootloader}, for example, it should be a device
20710 name understood by the bootloader @command{installer} command, such as
20711 @code{/dev/sda} or @code{(hd0)} (for GRUB, @pxref{Invoking
20712 grub-install,,, grub, GNU GRUB Manual}). For
20713 @code{grub-efi-bootloader}, it should be the path to a mounted EFI file
20716 @item @code{menu-entries} (default: @code{()})
20717 A possibly empty list of @code{menu-entry} objects (see below), denoting
20718 entries to appear in the bootloader menu, in addition to the current
20719 system entry and the entry pointing to previous system generations.
20721 @item @code{default-entry} (default: @code{0})
20722 The index of the default boot menu entry. Index 0 is for the entry of the
20725 @item @code{timeout} (default: @code{5})
20726 The number of seconds to wait for keyboard input before booting. Set to
20727 0 to boot immediately, and to -1 to wait indefinitely.
20729 @item @code{theme} (default: @var{#f})
20730 The bootloader theme object describing the theme to use. If no theme
20731 is provided, some bootloaders might use a default theme, that's true
20734 @item @code{terminal-outputs} (default: @code{'gfxterm})
20735 The output terminals used for the bootloader boot menu, as a list of
20736 symbols. GRUB accepts the values: @code{console}, @code{serial},
20737 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
20738 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
20739 corresponds to the GRUB variable GRUB_TERMINAL_OUTPUT (@pxref{Simple
20740 configuration,,, grub,GNU GRUB manual}).
20742 @item @code{terminal-inputs} (default: @code{'()})
20743 The input terminals used for the bootloader boot menu, as a list of
20744 symbols. For GRUB, the default is the native platform terminal as
20745 determined at run-time. GRUB accepts the values: @code{console},
20746 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
20747 @code{usb_keyboard}. This field corresponds to the GRUB variable
20748 GRUB_TERMINAL_INPUT (@pxref{Simple configuration,,, grub,GNU GRUB
20751 @item @code{serial-unit} (default: @code{#f})
20752 The serial unit used by the bootloader, as an integer from 0 to 3.
20753 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
20754 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
20756 @item @code{serial-speed} (default: @code{#f})
20757 The speed of the serial interface, as an integer. For GRUB, the
20758 default value is chosen at run-time; currently GRUB chooses
20759 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
20766 Should you want to list additional boot menu entries @i{via} the
20767 @code{menu-entries} field above, you will need to create them with the
20768 @code{menu-entry} form. For example, imagine you want to be able to
20769 boot another distro (hard to imagine!), you can define a menu entry
20774 (label "The Other Distro")
20775 (linux "/boot/old/vmlinux-2.6.32")
20776 (linux-arguments '("root=/dev/sda2"))
20777 (initrd "/boot/old/initrd"))
20782 @deftp {Data Type} menu-entry
20783 The type of an entry in the bootloader menu.
20788 The label to show in the menu---e.g., @code{"GNU"}.
20791 The Linux kernel image to boot, for example:
20794 (file-append linux-libre "/bzImage")
20797 For GRUB, it is also possible to specify a device explicitly in the
20798 file path using GRUB's device naming convention (@pxref{Naming
20799 convention,,, grub, GNU GRUB manual}), for example:
20802 "(hd0,msdos1)/boot/vmlinuz"
20805 If the device is specified explicitly as above, then the @code{device}
20806 field is ignored entirely.
20808 @item @code{linux-arguments} (default: @code{()})
20809 The list of extra Linux kernel command-line arguments---e.g.,
20810 @code{("console=ttyS0")}.
20812 @item @code{initrd}
20813 A G-Expression or string denoting the file name of the initial RAM disk
20814 to use (@pxref{G-Expressions}).
20815 @item @code{device} (default: @code{#f})
20816 The device where the kernel and initrd are to be found---i.e., for GRUB,
20817 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
20819 This may be a file system label (a string), a file system UUID (a
20820 bytevector, @pxref{File Systems}), or @code{#f}, in which case
20821 the bootloader will search the device containing the file specified by
20822 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
20823 must @emph{not} be an OS device name such as @file{/dev/sda1}.
20828 @c FIXME: Write documentation once it's stable.
20829 Fow now only GRUB has theme support. GRUB themes are created using
20830 the @code{grub-theme} form, which is not documented yet.
20832 @defvr {Scheme Variable} %default-theme
20833 This is the default GRUB theme used by the operating system if no
20834 @code{theme} field is specified in @code{bootloader-configuration}
20837 It comes with a fancy background image displaying the GNU and Guix
20842 @node Invoking guix system
20843 @subsection Invoking @code{guix system}
20845 Once you have written an operating system declaration as seen in the
20846 previous section, it can be @dfn{instantiated} using the @command{guix
20847 system} command. The synopsis is:
20850 guix system @var{options}@dots{} @var{action} @var{file}
20853 @var{file} must be the name of a file containing an
20854 @code{operating-system} declaration. @var{action} specifies how the
20855 operating system is instantiated. Currently the following values are
20860 Display available service type definitions that match the given regular
20861 expressions, sorted by relevance:
20864 $ guix system search console font
20865 name: console-fonts
20866 location: gnu/services/base.scm:729:2
20867 extends: shepherd-root
20868 description: Install the given fonts on the specified ttys (fonts are
20869 + per virtual console on GNU/Linux). The value of this service is a list
20870 + of tty/font pairs like:
20872 + '(("tty1" . "LatGrkCyr-8x16"))
20876 location: gnu/services/base.scm:1048:2
20877 extends: shepherd-root
20878 description: Provide console login using the `mingetty' program.
20882 location: gnu/services/base.scm:775:2
20884 description: Provide a console log-in service as specified by its
20885 + configuration value, a `login-configuration' object.
20891 As for @command{guix package --search}, the result is written in
20892 @code{recutils} format, which makes it easy to filter the output
20893 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
20896 Build the operating system described in @var{file}, activate it, and
20897 switch to it@footnote{This action (and the related actions
20898 @code{switch-generation} and @code{roll-back}) are usable only on
20899 systems already running GuixSD.}.
20901 This effects all the configuration specified in @var{file}: user
20902 accounts, system services, global package list, setuid programs, etc.
20903 The command starts system services specified in @var{file} that are not
20904 currently running; if a service is currently running, it does not
20905 attempt to upgrade it since this would not be possible without stopping it
20908 This command creates a new generation whose number is one greater than
20909 the current generation (as reported by @command{guix system
20910 list-generations}). If that generation already exists, it will be
20911 overwritten. This behavior mirrors that of @command{guix package}
20912 (@pxref{Invoking guix package}).
20914 It also adds a bootloader menu entry for the new OS configuration,
20915 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
20916 entries for older configurations to a submenu, allowing you to choose
20917 an older system generation at boot time should you need it.
20920 @c The paragraph below refers to the problem discussed at
20921 @c <http://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
20922 It is highly recommended to run @command{guix pull} once before you run
20923 @command{guix system reconfigure} for the first time (@pxref{Invoking
20924 guix pull}). Failing to do that you would see an older version of Guix
20925 once @command{reconfigure} has completed.
20928 @item switch-generation
20929 @cindex generations
20930 Switch to an existing system generation. This action atomically
20931 switches the system profile to the specified system generation. It
20932 also rearranges the system's existing bootloader menu entries. It
20933 makes the menu entry for the specified system generation the default,
20934 and it moves the entries for the other generatiors to a submenu, if
20935 supported by the bootloader being used. The next time the system
20936 boots, it will use the specified system generation.
20938 The bootloader itself is not being reinstalled when using this
20939 command. Thus, the installed bootloader is used with an updated
20940 configuration file.
20942 The target generation can be specified explicitly by its generation
20943 number. For example, the following invocation would switch to system
20947 guix system switch-generation 7
20950 The target generation can also be specified relative to the current
20951 generation with the form @code{+N} or @code{-N}, where @code{+3} means
20952 ``3 generations ahead of the current generation,'' and @code{-1} means
20953 ``1 generation prior to the current generation.'' When specifying a
20954 negative value such as @code{-1}, you must precede it with @code{--} to
20955 prevent it from being parsed as an option. For example:
20958 guix system switch-generation -- -1
20961 Currently, the effect of invoking this action is @emph{only} to switch
20962 the system profile to an existing generation and rearrange the
20963 bootloader menu entries. To actually start using the target system
20964 generation, you must reboot after running this action. In the future,
20965 it will be updated to do the same things as @command{reconfigure},
20966 like activating and deactivating services.
20968 This action will fail if the specified generation does not exist.
20971 @cindex rolling back
20972 Switch to the preceding system generation. The next time the system
20973 boots, it will use the preceding system generation. This is the inverse
20974 of @command{reconfigure}, and it is exactly the same as invoking
20975 @command{switch-generation} with an argument of @code{-1}.
20977 Currently, as with @command{switch-generation}, you must reboot after
20978 running this action to actually start using the preceding system
20982 Build the derivation of the operating system, which includes all the
20983 configuration files and programs needed to boot and run the system.
20984 This action does not actually install anything.
20987 Populate the given directory with all the files necessary to run the
20988 operating system specified in @var{file}. This is useful for first-time
20989 installations of GuixSD. For instance:
20992 guix system init my-os-config.scm /mnt
20995 copies to @file{/mnt} all the store items required by the configuration
20996 specified in @file{my-os-config.scm}. This includes configuration
20997 files, packages, and so on. It also creates other essential files
20998 needed for the system to operate correctly---e.g., the @file{/etc},
20999 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
21001 This command also installs bootloader on the target specified in
21002 @file{my-os-config}, unless the @option{--no-bootloader} option was
21006 @cindex virtual machine
21008 @anchor{guix system vm}
21009 Build a virtual machine that contains the operating system declared in
21010 @var{file}, and return a script to run that virtual machine (VM).
21011 Arguments given to the script are passed to QEMU as in the example
21012 below, which enables networking and requests 1@tie{}GiB of RAM for the
21016 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
21019 The VM shares its store with the host system.
21021 Additional file systems can be shared between the host and the VM using
21022 the @code{--share} and @code{--expose} command-line options: the former
21023 specifies a directory to be shared with write access, while the latter
21024 provides read-only access to the shared directory.
21026 The example below creates a VM in which the user's home directory is
21027 accessible read-only, and where the @file{/exchange} directory is a
21028 read-write mapping of @file{$HOME/tmp} on the host:
21031 guix system vm my-config.scm \
21032 --expose=$HOME --share=$HOME/tmp=/exchange
21035 On GNU/Linux, the default is to boot directly to the kernel; this has
21036 the advantage of requiring only a very tiny root disk image since the
21037 store of the host can then be mounted.
21039 The @code{--full-boot} option forces a complete boot sequence, starting
21040 with the bootloader. This requires more disk space since a root image
21041 containing at least the kernel, initrd, and bootloader data files must
21042 be created. The @code{--image-size} option can be used to specify the
21045 @cindex System images, creation in various formats
21046 @cindex Creating system images in various formats
21049 @itemx docker-image
21050 Return a virtual machine, disk image, or Docker image of the operating
21051 system declared in @var{file} that stands alone. By default,
21052 @command{guix system} estimates the size of the image needed to store
21053 the system, but you can use the @option{--image-size} option to specify
21054 a value. Docker images are built to contain exactly what they need, so
21055 the @option{--image-size} option is ignored in the case of
21056 @code{docker-image}.
21058 You can specify the root file system type by using the
21059 @option{--file-system-type} option. It defaults to @code{ext4}.
21061 When using @code{vm-image}, the returned image is in qcow2 format, which
21062 the QEMU emulator can efficiently use. @xref{Running GuixSD in a VM},
21063 for more information on how to run the image in a virtual machine.
21065 When using @code{disk-image}, a raw disk image is produced; it can be
21066 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
21067 the device corresponding to a USB stick, one can copy the image to it
21068 using the following command:
21071 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
21074 When using @code{docker-image}, a Docker image is produced. Guix builds
21075 the image from scratch, not from a pre-existing Docker base image. As a
21076 result, it contains @emph{exactly} what you define in the operating
21077 system configuration file. You can then load the image and launch a
21078 Docker container using commands like the following:
21081 image_id="$(docker load < guixsd-docker-image.tar.gz)"
21082 docker run -e GUIX_NEW_SYSTEM=/var/guix/profiles/system \\
21083 --entrypoint /var/guix/profiles/system/profile/bin/guile \\
21084 $image_id /var/guix/profiles/system/boot
21087 This command starts a new Docker container from the specified image. It
21088 will boot the GuixSD system in the usual manner, which means it will
21089 start any services you have defined in the operating system
21090 configuration. Depending on what you run in the Docker container, it
21091 may be necessary to give the container additional permissions. For
21092 example, if you intend to build software using Guix inside of the Docker
21093 container, you may need to pass the @option{--privileged} option to
21097 Return a script to run the operating system declared in @var{file}
21098 within a container. Containers are a set of lightweight isolation
21099 mechanisms provided by the kernel Linux-libre. Containers are
21100 substantially less resource-demanding than full virtual machines since
21101 the kernel, shared objects, and other resources can be shared with the
21102 host system; this also means they provide thinner isolation.
21104 Currently, the script must be run as root in order to support more than
21105 a single user and group. The container shares its store with the host
21108 As with the @code{vm} action (@pxref{guix system vm}), additional file
21109 systems to be shared between the host and container can be specified
21110 using the @option{--share} and @option{--expose} options:
21113 guix system container my-config.scm \
21114 --expose=$HOME --share=$HOME/tmp=/exchange
21118 This option requires Linux-libre 3.19 or newer.
21123 @var{options} can contain any of the common build options (@pxref{Common
21124 Build Options}). In addition, @var{options} can contain one of the
21128 @item --expression=@var{expr}
21129 @itemx -e @var{expr}
21130 Consider the operating-system @var{expr} evaluates to.
21131 This is an alternative to specifying a file which evaluates to an
21133 This is used to generate the GuixSD installer @pxref{Building the
21134 Installation Image}).
21136 @item --system=@var{system}
21137 @itemx -s @var{system}
21138 Attempt to build for @var{system} instead of the host system type.
21139 This works as per @command{guix build} (@pxref{Invoking guix build}).
21143 Return the derivation file name of the given operating system without
21146 @item --file-system-type=@var{type}
21147 @itemx -t @var{type}
21148 For the @code{disk-image} action, create a file system of the given
21149 @var{type} on the image.
21151 When this option is omitted, @command{guix system} uses @code{ext4}.
21153 @cindex ISO-9660 format
21154 @cindex CD image format
21155 @cindex DVD image format
21156 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
21157 for burning on CDs and DVDs.
21159 @item --image-size=@var{size}
21160 For the @code{vm-image} and @code{disk-image} actions, create an image
21161 of the given @var{size}. @var{size} may be a number of bytes, or it may
21162 include a unit as a suffix (@pxref{Block size, size specifications,,
21163 coreutils, GNU Coreutils}).
21165 When this option is omitted, @command{guix system} computes an estimate
21166 of the image size as a function of the size of the system declared in
21169 @item --root=@var{file}
21170 @itemx -r @var{file}
21171 Make @var{file} a symlink to the result, and register it as a garbage
21174 @item --skip-checks
21175 Skip pre-installation safety checks.
21177 By default, @command{guix system init} and @command{guix system
21178 reconfigure} perform safety checks: they make sure the file systems that
21179 appear in the @code{operating-system} declaration actually exist
21180 (@pxref{File Systems}), and that any Linux kernel modules that may be
21181 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
21182 RAM Disk}). Passing this option skips these tests altogether.
21184 @item --on-error=@var{strategy}
21185 Apply @var{strategy} when an error occurs when reading @var{file}.
21186 @var{strategy} may be one of the following:
21189 @item nothing-special
21190 Report the error concisely and exit. This is the default strategy.
21193 Likewise, but also display a backtrace.
21196 Report the error and enter Guile's debugger. From there, you can run
21197 commands such as @code{,bt} to get a backtrace, @code{,locals} to
21198 display local variable values, and more generally inspect the state of the
21199 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
21200 a list of available debugging commands.
21205 All the actions above, except @code{build} and @code{init},
21206 can use KVM support in the Linux-libre kernel. Specifically, if the
21207 machine has hardware virtualization support, the corresponding
21208 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
21209 must exist and be readable and writable by the user and by the
21210 build users of the daemon (@pxref{Build Environment Setup}).
21213 Once you have built, configured, re-configured, and re-re-configured
21214 your GuixSD installation, you may find it useful to list the operating
21215 system generations available on disk---and that you can choose from the
21216 bootloader boot menu:
21220 @item list-generations
21221 List a summary of each generation of the operating system available on
21222 disk, in a human-readable way. This is similar to the
21223 @option{--list-generations} option of @command{guix package}
21224 (@pxref{Invoking guix package}).
21226 Optionally, one can specify a pattern, with the same syntax that is used
21227 in @command{guix package --list-generations}, to restrict the list of
21228 generations displayed. For instance, the following command displays
21229 generations that are up to 10 days old:
21232 $ guix system list-generations 10d
21237 The @command{guix system} command has even more to offer! The following
21238 sub-commands allow you to visualize how your system services relate to
21241 @anchor{system-extension-graph}
21244 @item extension-graph
21245 Emit in Dot/Graphviz format to standard output the @dfn{service
21246 extension graph} of the operating system defined in @var{file}
21247 (@pxref{Service Composition}, for more information on service
21253 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
21256 produces a PDF file showing the extension relations among services.
21258 @anchor{system-shepherd-graph}
21259 @item shepherd-graph
21260 Emit in Dot/Graphviz format to standard output the @dfn{dependency
21261 graph} of shepherd services of the operating system defined in
21262 @var{file}. @xref{Shepherd Services}, for more information and for an
21267 @node Running GuixSD in a VM
21268 @subsection Running GuixSD in a Virtual Machine
21270 @cindex virtual machine
21271 To run GuixSD in a virtual machine (VM), one can either use the
21272 pre-built GuixSD VM image distributed at
21273 @indicateurl{ftp://alpha.gnu.org/guix/guixsd-vm-image-@value{VERSION}.@var{system}.tar.xz}
21274 , or build their own virtual machine image using @command{guix system
21275 vm-image} (@pxref{Invoking guix system}). The returned image is in
21276 qcow2 format, which the @uref{http://qemu.org/, QEMU emulator} can
21280 If you built your own image, you must copy it out of the store
21281 (@pxref{The Store}) and give yourself permission to write to the copy
21282 before you can use it. When invoking QEMU, you must choose a system
21283 emulator that is suitable for your hardware platform. Here is a minimal
21284 QEMU invocation that will boot the result of @command{guix system
21285 vm-image} on x86_64 hardware:
21288 $ qemu-system-x86_64 \
21289 -net user -net nic,model=virtio \
21290 -enable-kvm -m 256 /tmp/qemu-image
21293 Here is what each of these options means:
21296 @item qemu-system-x86_64
21297 This specifies the hardware platform to emulate. This should match the
21301 Enable the unprivileged user-mode network stack. The guest OS can
21302 access the host but not vice versa. This is the simplest way to get the
21305 @item -net nic,model=virtio
21306 You must create a network interface of a given model. If you do not
21307 create a NIC, the boot will fail. Assuming your hardware platform is
21308 x86_64, you can get a list of available NIC models by running
21309 @command{qemu-system-x86_64 -net nic,model=help}.
21312 If your system has hardware virtualization extensions, enabling the
21313 virtual machine support (KVM) of the Linux kernel will make things run
21317 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
21318 which may be insufficient for some operations.
21320 @item /tmp/qemu-image
21321 The file name of the qcow2 image.
21324 The default @command{run-vm.sh} script that is returned by an invocation of
21325 @command{guix system vm} does not add a @command{-net user} flag by default.
21326 To get network access from within the vm add the @code{(dhcp-client-service)}
21327 to your system definition and start the VM using
21328 @command{`guix system vm config.scm` -net user}. An important caveat of using
21329 @command{-net user} for networking is that @command{ping} will not work, because
21330 it uses the ICMP protocol. You'll have to use a different command to check for
21331 network connectivity, for example @command{guix download}.
21333 @subsubsection Connecting Through SSH
21337 To enable SSH inside a VM you need to add a SSH server like @code{(dropbear-service)}
21338 or @code{(lsh-service)} to your VM. The @code{(lsh-service}) doesn't currently
21339 boot unsupervised. It requires you to type some characters to initialize the
21340 randomness generator. In addition you need to forward the SSH port, 22 by
21341 default, to the host. You can do this with
21344 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
21347 To connect to the VM you can run
21350 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
21353 The @command{-p} tells @command{ssh} the port you want to connect to.
21354 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
21355 every time you modify your @command{config.scm} file and the
21356 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
21357 connection to an unknown host every time you connect.
21359 @subsubsection Using @command{virt-viewer} with Spice
21361 As an alternative to the default @command{qemu} graphical client you can
21362 use the @command{remote-viewer} from the @command{virt-viewer} package. To
21363 connect pass the @command{-spice port=5930,disable-ticketing} flag to
21364 @command{qemu}. See previous section for further information on how to do this.
21366 Spice also allows you to do some nice stuff like share your clipboard with your
21367 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
21370 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
21371 -chardev spicevmc,name=vdagent,id=vdagent
21372 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
21373 name=com.redhat.spice.0
21376 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
21378 @node Defining Services
21379 @subsection Defining Services
21381 The previous sections show the available services and how one can combine
21382 them in an @code{operating-system} declaration. But how do we define
21383 them in the first place? And what is a service anyway?
21386 * Service Composition:: The model for composing services.
21387 * Service Types and Services:: Types and services.
21388 * Service Reference:: API reference.
21389 * Shepherd Services:: A particular type of service.
21392 @node Service Composition
21393 @subsubsection Service Composition
21397 Here we define a @dfn{service} as, broadly, something that extends the
21398 functionality of the operating system. Often a service is a process---a
21399 @dfn{daemon}---started when the system boots: a secure shell server, a
21400 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
21401 whose execution can be triggered by another daemon---e.g., an FTP server
21402 started by @command{inetd} or a D-Bus service activated by
21403 @command{dbus-daemon}. Occasionally, a service does not map to a
21404 daemon. For instance, the ``account'' service collects user accounts
21405 and makes sure they exist when the system runs; the ``udev'' service
21406 collects device management rules and makes them available to the eudev
21407 daemon; the @file{/etc} service populates the @file{/etc} directory
21410 @cindex service extensions
21411 GuixSD services are connected by @dfn{extensions}. For instance, the
21412 secure shell service @emph{extends} the Shepherd---the GuixSD
21413 initialization system, running as PID@tie{}1---by giving it the command
21414 lines to start and stop the secure shell daemon (@pxref{Networking
21415 Services, @code{lsh-service}}); the UPower service extends the D-Bus
21416 service by passing it its @file{.service} specification, and extends the
21417 udev service by passing it device management rules (@pxref{Desktop
21418 Services, @code{upower-service}}); the Guix daemon service extends the
21419 Shepherd by passing it the command lines to start and stop the daemon,
21420 and extends the account service by passing it a list of required build
21421 user accounts (@pxref{Base Services}).
21423 All in all, services and their ``extends'' relations form a directed
21424 acyclic graph (DAG). If we represent services as boxes and extensions
21425 as arrows, a typical system might provide something like this:
21427 @image{images/service-graph,,5in,Typical service extension graph.}
21429 @cindex system service
21430 At the bottom, we see the @dfn{system service}, which produces the
21431 directory containing everything to run and boot the system, as returned
21432 by the @command{guix system build} command. @xref{Service Reference},
21433 to learn about the other service types shown here.
21434 @xref{system-extension-graph, the @command{guix system extension-graph}
21435 command}, for information on how to generate this representation for a
21436 particular operating system definition.
21438 @cindex service types
21439 Technically, developers can define @dfn{service types} to express these
21440 relations. There can be any number of services of a given type on the
21441 system---for instance, a system running two instances of the GNU secure
21442 shell server (lsh) has two instances of @var{lsh-service-type}, with
21443 different parameters.
21445 The following section describes the programming interface for service
21446 types and services.
21448 @node Service Types and Services
21449 @subsubsection Service Types and Services
21451 A @dfn{service type} is a node in the DAG described above. Let us start
21452 with a simple example, the service type for the Guix build daemon
21453 (@pxref{Invoking guix-daemon}):
21456 (define guix-service-type
21460 (list (service-extension shepherd-root-service-type guix-shepherd-service)
21461 (service-extension account-service-type guix-accounts)
21462 (service-extension activation-service-type guix-activation)))
21463 (default-value (guix-configuration))))
21467 It defines three things:
21471 A name, whose sole purpose is to make inspection and debugging easier.
21474 A list of @dfn{service extensions}, where each extension designates the
21475 target service type and a procedure that, given the parameters of the
21476 service, returns a list of objects to extend the service of that type.
21478 Every service type has at least one service extension. The only
21479 exception is the @dfn{boot service type}, which is the ultimate service.
21482 Optionally, a default value for instances of this type.
21485 In this example, @var{guix-service-type} extends three services:
21488 @item shepherd-root-service-type
21489 The @var{guix-shepherd-service} procedure defines how the Shepherd
21490 service is extended. Namely, it returns a @code{<shepherd-service>}
21491 object that defines how @command{guix-daemon} is started and stopped
21492 (@pxref{Shepherd Services}).
21494 @item account-service-type
21495 This extension for this service is computed by @var{guix-accounts},
21496 which returns a list of @code{user-group} and @code{user-account}
21497 objects representing the build user accounts (@pxref{Invoking
21500 @item activation-service-type
21501 Here @var{guix-activation} is a procedure that returns a gexp, which is
21502 a code snippet to run at ``activation time''---e.g., when the service is
21506 A service of this type is instantiated like this:
21509 (service guix-service-type
21510 (guix-configuration
21512 (use-substitutes? #f)))
21515 The second argument to the @code{service} form is a value representing
21516 the parameters of this specific service instance.
21517 @xref{guix-configuration-type, @code{guix-configuration}}, for
21518 information about the @code{guix-configuration} data type. When the
21519 value is omitted, the default value specified by
21520 @code{guix-service-type} is used:
21523 (service guix-service-type)
21526 @var{guix-service-type} is quite simple because it extends other
21527 services but is not extensible itself.
21529 @c @subsubsubsection Extensible Service Types
21531 The service type for an @emph{extensible} service looks like this:
21534 (define udev-service-type
21535 (service-type (name 'udev)
21537 (list (service-extension shepherd-root-service-type
21538 udev-shepherd-service)))
21540 (compose concatenate) ;concatenate the list of rules
21541 (extend (lambda (config rules)
21543 (($ <udev-configuration> udev initial-rules)
21544 (udev-configuration
21545 (udev udev) ;the udev package to use
21546 (rules (append initial-rules rules)))))))))
21549 This is the service type for the
21550 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
21551 management daemon}. Compared to the previous example, in addition to an
21552 extension of @var{shepherd-root-service-type}, we see two new fields:
21556 This is the procedure to @dfn{compose} the list of extensions to
21557 services of this type.
21559 Services can extend the udev service by passing it lists of rules; we
21560 compose those extensions simply by concatenating them.
21563 This procedure defines how the value of the service is @dfn{extended} with
21564 the composition of the extensions.
21566 Udev extensions are composed into a list of rules, but the udev service
21567 value is itself a @code{<udev-configuration>} record. So here, we
21568 extend that record by appending the list of rules it contains to the
21569 list of contributed rules.
21572 This is a string giving an overview of the service type. The string can
21573 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
21574 @command{guix system search} command searches these strings and displays
21575 them (@pxref{Invoking guix system}).
21578 There can be only one instance of an extensible service type such as
21579 @var{udev-service-type}. If there were more, the
21580 @code{service-extension} specifications would be ambiguous.
21582 Still here? The next section provides a reference of the programming
21583 interface for services.
21585 @node Service Reference
21586 @subsubsection Service Reference
21588 We have seen an overview of service types (@pxref{Service Types and
21589 Services}). This section provides a reference on how to manipulate
21590 services and service types. This interface is provided by the
21591 @code{(gnu services)} module.
21593 @deffn {Scheme Procedure} service @var{type} [@var{value}]
21594 Return a new service of @var{type}, a @code{<service-type>} object (see
21595 below.) @var{value} can be any object; it represents the parameters of
21596 this particular service instance.
21598 When @var{value} is omitted, the default value specified by @var{type}
21599 is used; if @var{type} does not specify a default value, an error is
21602 For instance, this:
21605 (service openssh-service-type)
21609 is equivalent to this:
21612 (service openssh-service-type
21613 (openssh-configuration))
21616 In both cases the result is an instance of @code{openssh-service-type}
21617 with the default configuration.
21620 @deffn {Scheme Procedure} service? @var{obj}
21621 Return true if @var{obj} is a service.
21624 @deffn {Scheme Procedure} service-kind @var{service}
21625 Return the type of @var{service}---i.e., a @code{<service-type>} object.
21628 @deffn {Scheme Procedure} service-value @var{service}
21629 Return the value associated with @var{service}. It represents its
21633 Here is an example of how a service is created and manipulated:
21637 (service nginx-service-type
21638 (nginx-configuration
21640 (log-directory log-directory)
21641 (run-directory run-directory)
21642 (file config-file))))
21647 (eq? (service-kind s) nginx-service-type)
21651 The @code{modify-services} form provides a handy way to change the
21652 parameters of some of the services of a list such as
21653 @var{%base-services} (@pxref{Base Services, @code{%base-services}}). It
21654 evaluates to a list of services. Of course, you could always use
21655 standard list combinators such as @code{map} and @code{fold} to do that
21656 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
21657 @code{modify-services} simply provides a more concise form for this
21660 @deffn {Scheme Syntax} modify-services @var{services} @
21661 (@var{type} @var{variable} => @var{body}) @dots{}
21663 Modify the services listed in @var{services} according to the given
21664 clauses. Each clause has the form:
21667 (@var{type} @var{variable} => @var{body})
21670 where @var{type} is a service type---e.g.,
21671 @code{guix-service-type}---and @var{variable} is an identifier that is
21672 bound within the @var{body} to the service parameters---e.g., a
21673 @code{guix-configuration} instance---of the original service of that
21676 The @var{body} should evaluate to the new service parameters, which will
21677 be used to configure the new service. This new service will replace the
21678 original in the resulting list. Because a service's service parameters
21679 are created using @code{define-record-type*}, you can write a succinct
21680 @var{body} that evaluates to the new service parameters by using the
21681 @code{inherit} feature that @code{define-record-type*} provides.
21683 @xref{Using the Configuration System}, for example usage.
21687 Next comes the programming interface for service types. This is
21688 something you want to know when writing new service definitions, but not
21689 necessarily when simply looking for ways to customize your
21690 @code{operating-system} declaration.
21692 @deftp {Data Type} service-type
21693 @cindex service type
21694 This is the representation of a @dfn{service type} (@pxref{Service Types
21699 This is a symbol, used only to simplify inspection and debugging.
21701 @item @code{extensions}
21702 A non-empty list of @code{<service-extension>} objects (see below).
21704 @item @code{compose} (default: @code{#f})
21705 If this is @code{#f}, then the service type denotes services that cannot
21706 be extended---i.e., services that do not receive ``values'' from other
21709 Otherwise, it must be a one-argument procedure. The procedure is called
21710 by @code{fold-services} and is passed a list of values collected from
21711 extensions. It may return any single value.
21713 @item @code{extend} (default: @code{#f})
21714 If this is @code{#f}, services of this type cannot be extended.
21716 Otherwise, it must be a two-argument procedure: @code{fold-services}
21717 calls it, passing it the initial value of the service as the first
21718 argument and the result of applying @code{compose} to the extension
21719 values as the second argument. It must return a value that is a valid
21720 parameter value for the service instance.
21723 @xref{Service Types and Services}, for examples.
21726 @deffn {Scheme Procedure} service-extension @var{target-type} @
21728 Return a new extension for services of type @var{target-type}.
21729 @var{compute} must be a one-argument procedure: @code{fold-services}
21730 calls it, passing it the value associated with the service that provides
21731 the extension; it must return a valid value for the target service.
21734 @deffn {Scheme Procedure} service-extension? @var{obj}
21735 Return true if @var{obj} is a service extension.
21738 Occasionally, you might want to simply extend an existing service. This
21739 involves creating a new service type and specifying the extension of
21740 interest, which can be verbose; the @code{simple-service} procedure
21741 provides a shorthand for this.
21743 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
21744 Return a service that extends @var{target} with @var{value}. This works
21745 by creating a singleton service type @var{name}, of which the returned
21746 service is an instance.
21748 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
21752 (simple-service 'my-mcron-job mcron-service-type
21753 #~(job '(next-hour (3)) "guix gc -F 2G"))
21757 At the core of the service abstraction lies the @code{fold-services}
21758 procedure, which is responsible for ``compiling'' a list of services
21759 down to a single directory that contains everything needed to boot and
21760 run the system---the directory shown by the @command{guix system build}
21761 command (@pxref{Invoking guix system}). In essence, it propagates
21762 service extensions down the service graph, updating each node parameters
21763 on the way, until it reaches the root node.
21765 @deffn {Scheme Procedure} fold-services @var{services} @
21766 [#:target-type @var{system-service-type}]
21767 Fold @var{services} by propagating their extensions down to the root of
21768 type @var{target-type}; return the root service adjusted accordingly.
21771 Lastly, the @code{(gnu services)} module also defines several essential
21772 service types, some of which are listed below.
21774 @defvr {Scheme Variable} system-service-type
21775 This is the root of the service graph. It produces the system directory
21776 as returned by the @command{guix system build} command.
21779 @defvr {Scheme Variable} boot-service-type
21780 The type of the ``boot service'', which produces the @dfn{boot script}.
21781 The boot script is what the initial RAM disk runs when booting.
21784 @defvr {Scheme Variable} etc-service-type
21785 The type of the @file{/etc} service. This service is used to create
21786 files under @file{/etc} and can be extended by
21787 passing it name/file tuples such as:
21790 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
21793 In this example, the effect would be to add an @file{/etc/issue} file
21794 pointing to the given file.
21797 @defvr {Scheme Variable} setuid-program-service-type
21798 Type for the ``setuid-program service''. This service collects lists of
21799 executable file names, passed as gexps, and adds them to the set of
21800 setuid-root programs on the system (@pxref{Setuid Programs}).
21803 @defvr {Scheme Variable} profile-service-type
21804 Type of the service that populates the @dfn{system profile}---i.e., the
21805 programs under @file{/run/current-system/profile}. Other services can
21806 extend it by passing it lists of packages to add to the system profile.
21810 @node Shepherd Services
21811 @subsubsection Shepherd Services
21813 @cindex shepherd services
21815 @cindex init system
21816 The @code{(gnu services shepherd)} module provides a way to define
21817 services managed by the GNU@tie{}Shepherd, which is the GuixSD
21818 initialization system---the first process that is started when the
21819 system boots, also known as PID@tie{}1
21820 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
21822 Services in the Shepherd can depend on each other. For instance, the
21823 SSH daemon may need to be started after the syslog daemon has been
21824 started, which in turn can only happen once all the file systems have
21825 been mounted. The simple operating system defined earlier (@pxref{Using
21826 the Configuration System}) results in a service graph like this:
21828 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
21830 You can actually generate such a graph for any operating system
21831 definition using the @command{guix system shepherd-graph} command
21832 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
21834 The @var{%shepherd-root-service} is a service object representing
21835 PID@tie{}1, of type @var{shepherd-root-service-type}; it can be extended
21836 by passing it lists of @code{<shepherd-service>} objects.
21838 @deftp {Data Type} shepherd-service
21839 The data type representing a service managed by the Shepherd.
21842 @item @code{provision}
21843 This is a list of symbols denoting what the service provides.
21845 These are the names that may be passed to @command{herd start},
21846 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
21847 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
21848 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
21850 @item @code{requirements} (default: @code{'()})
21851 List of symbols denoting the Shepherd services this one depends on.
21853 @item @code{respawn?} (default: @code{#t})
21854 Whether to restart the service when it stops, for instance when the
21855 underlying process dies.
21858 @itemx @code{stop} (default: @code{#~(const #f)})
21859 The @code{start} and @code{stop} fields refer to the Shepherd's
21860 facilities to start and stop processes (@pxref{Service De- and
21861 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
21862 G-expressions that get expanded in the Shepherd configuration file
21863 (@pxref{G-Expressions}).
21865 @item @code{documentation}
21866 A documentation string, as shown when running:
21869 herd doc @var{service-name}
21872 where @var{service-name} is one of the symbols in @var{provision}
21873 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
21875 @item @code{modules} (default: @var{%default-modules})
21876 This is the list of modules that must be in scope when @code{start} and
21877 @code{stop} are evaluated.
21882 @defvr {Scheme Variable} shepherd-root-service-type
21883 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
21885 This is the service type that extensions target when they want to create
21886 shepherd services (@pxref{Service Types and Services}, for an example).
21887 Each extension must pass a list of @code{<shepherd-service>}.
21890 @defvr {Scheme Variable} %shepherd-root-service
21891 This service represents PID@tie{}1.
21895 @node Documentation
21896 @section Documentation
21898 @cindex documentation, searching for
21899 @cindex searching for documentation
21900 @cindex Info, documentation format
21902 @cindex manual pages
21903 In most cases packages installed with Guix come with documentation.
21904 There are two main documentation formats: ``Info'', a browseable
21905 hypertext format used for GNU software, and ``manual pages'' (or ``man
21906 pages''), the linear documentation format traditionally found on Unix.
21907 Info manuals are accessed with the @command{info} command or with Emacs,
21908 and man pages are accessed using @command{man}.
21910 You can look for documentation of software installed on your system by
21911 keyword. For example, the following command searches for information
21912 about ``TLS'' in Info manuals:
21916 "(emacs)Network Security" -- STARTTLS
21917 "(emacs)Network Security" -- TLS
21918 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
21919 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
21924 The command below searches for the same keyword in man pages:
21928 SSL (7) - OpenSSL SSL/TLS library
21929 certtool (1) - GnuTLS certificate tool
21933 These searches are purely local to your computer so you have the
21934 guarantee that documentation you find corresponds to what you have
21935 actually installed, you can access it off-line, and your privacy is
21938 Once you have these results, you can view the relevant documentation by
21942 $ info "(gnutls)Core TLS API"
21952 Info manuals contain sections and indices as well as hyperlinks like
21953 those found in Web pages. The @command{info} reader (@pxref{Top, Info
21954 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
21955 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
21956 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
21957 Introduction}, for an introduction to Info navigation.
21959 @node Installing Debugging Files
21960 @section Installing Debugging Files
21962 @cindex debugging files
21963 Program binaries, as produced by the GCC compilers for instance, are
21964 typically written in the ELF format, with a section containing
21965 @dfn{debugging information}. Debugging information is what allows the
21966 debugger, GDB, to map binary code to source code; it is required to
21967 debug a compiled program in good conditions.
21969 The problem with debugging information is that is takes up a fair amount
21970 of disk space. For example, debugging information for the GNU C Library
21971 weighs in at more than 60 MiB. Thus, as a user, keeping all the
21972 debugging info of all the installed programs is usually not an option.
21973 Yet, space savings should not come at the cost of an impediment to
21974 debugging---especially in the GNU system, which should make it easier
21975 for users to exert their computing freedom (@pxref{GNU Distribution}).
21977 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
21978 mechanism that allows users to get the best of both worlds: debugging
21979 information can be stripped from the binaries and stored in separate
21980 files. GDB is then able to load debugging information from those files,
21981 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
21984 The GNU distribution takes advantage of this by storing debugging
21985 information in the @code{lib/debug} sub-directory of a separate package
21986 output unimaginatively called @code{debug} (@pxref{Packages with
21987 Multiple Outputs}). Users can choose to install the @code{debug} output
21988 of a package when they need it. For instance, the following command
21989 installs the debugging information for the GNU C Library and for GNU
21993 guix package -i glibc:debug guile:debug
21996 GDB must then be told to look for debug files in the user's profile, by
21997 setting the @code{debug-file-directory} variable (consider setting it
21998 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
22002 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
22005 From there on, GDB will pick up debugging information from the
22006 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
22008 In addition, you will most likely want GDB to be able to show the source
22009 code being debugged. To do that, you will have to unpack the source
22010 code of the package of interest (obtained with @code{guix build
22011 --source}, @pxref{Invoking guix build}), and to point GDB to that source
22012 directory using the @code{directory} command (@pxref{Source Path,
22013 @code{directory},, gdb, Debugging with GDB}).
22015 @c XXX: keep me up-to-date
22016 The @code{debug} output mechanism in Guix is implemented by the
22017 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
22018 opt-in---debugging information is available only for the packages
22019 with definitions explicitly declaring a @code{debug} output. This may be
22020 changed to opt-out in the future if our build farm servers can handle
22021 the load. To check whether a package has a @code{debug} output, use
22022 @command{guix package --list-available} (@pxref{Invoking guix package}).
22025 @node Security Updates
22026 @section Security Updates
22028 @cindex security updates
22029 @cindex security vulnerabilities
22030 Occasionally, important security vulnerabilities are discovered in software
22031 packages and must be patched. Guix developers try hard to keep track of
22032 known vulnerabilities and to apply fixes as soon as possible in the
22033 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
22034 containing only security updates.) The @command{guix lint} tool helps
22035 developers find out about vulnerable versions of software packages in the
22040 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
22041 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
22042 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
22046 @xref{Invoking guix lint}, for more information.
22049 As of version @value{VERSION}, the feature described below is considered
22053 Guix follows a functional
22054 package management discipline (@pxref{Introduction}), which implies
22055 that, when a package is changed, @emph{every package that depends on it}
22056 must be rebuilt. This can significantly slow down the deployment of
22057 fixes in core packages such as libc or Bash, since basically the whole
22058 distribution would need to be rebuilt. Using pre-built binaries helps
22059 (@pxref{Substitutes}), but deployment may still take more time than
22063 To address this, Guix implements @dfn{grafts}, a mechanism that allows
22064 for fast deployment of critical updates without the costs associated
22065 with a whole-distribution rebuild. The idea is to rebuild only the
22066 package that needs to be patched, and then to ``graft'' it onto packages
22067 explicitly installed by the user and that were previously referring to
22068 the original package. The cost of grafting is typically very low, and
22069 order of magnitudes lower than a full rebuild of the dependency chain.
22071 @cindex replacements of packages, for grafts
22072 For instance, suppose a security update needs to be applied to Bash.
22073 Guix developers will provide a package definition for the ``fixed''
22074 Bash, say @var{bash-fixed}, in the usual way (@pxref{Defining
22075 Packages}). Then, the original package definition is augmented with a
22076 @code{replacement} field pointing to the package containing the bug fix:
22083 (replacement bash-fixed)))
22086 From there on, any package depending directly or indirectly on Bash---as
22087 reported by @command{guix gc --requisites} (@pxref{Invoking guix
22088 gc})---that is installed is automatically ``rewritten'' to refer to
22089 @var{bash-fixed} instead of @var{bash}. This grafting process takes
22090 time proportional to the size of the package, usually less than a
22091 minute for an ``average'' package on a recent machine. Grafting is
22092 recursive: when an indirect dependency requires grafting, then grafting
22093 ``propagates'' up to the package that the user is installing.
22095 Currently, the length of the name and version of the graft and that of
22096 the package it replaces (@var{bash-fixed} and @var{bash} in the example
22097 above) must be equal. This restriction mostly comes from the fact that
22098 grafting works by patching files, including binary files, directly.
22099 Other restrictions may apply: for instance, when adding a graft to a
22100 package providing a shared library, the original shared library and its
22101 replacement must have the same @code{SONAME} and be binary-compatible.
22103 The @option{--no-grafts} command-line option allows you to forcefully
22104 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
22108 guix build bash --no-grafts
22112 returns the store file name of the original Bash, whereas:
22119 returns the store file name of the ``fixed'', replacement Bash. This
22120 allows you to distinguish between the two variants of Bash.
22122 To verify which Bash your whole profile refers to, you can run
22123 (@pxref{Invoking guix gc}):
22126 guix gc -R `readlink -f ~/.guix-profile` | grep bash
22130 @dots{} and compare the store file names that you get with those above.
22131 Likewise for a complete GuixSD system generation:
22134 guix gc -R `guix system build my-config.scm` | grep bash
22137 Lastly, to check which Bash running processes are using, you can use the
22138 @command{lsof} command:
22141 lsof | grep /gnu/store/.*bash
22145 @node Package Modules
22146 @section Package Modules
22148 From a programming viewpoint, the package definitions of the
22149 GNU distribution are provided by Guile modules in the @code{(gnu packages
22150 @dots{})} name space@footnote{Note that packages under the @code{(gnu
22151 packages @dots{})} module name space are not necessarily ``GNU
22152 packages''. This module naming scheme follows the usual Guile module
22153 naming convention: @code{gnu} means that these modules are distributed
22154 as part of the GNU system, and @code{packages} identifies modules that
22155 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
22156 Reference Manual}). For instance, the @code{(gnu packages emacs)}
22157 module exports a variable named @code{emacs}, which is bound to a
22158 @code{<package>} object (@pxref{Defining Packages}).
22160 The @code{(gnu packages @dots{})} module name space is
22161 automatically scanned for packages by the command-line tools. For
22162 instance, when running @code{guix package -i emacs}, all the @code{(gnu
22163 packages @dots{})} modules are scanned until one that exports a package
22164 object whose name is @code{emacs} is found. This package search
22165 facility is implemented in the @code{(gnu packages)} module.
22167 @cindex customization, of packages
22168 @cindex package module search path
22169 Users can store package definitions in modules with different
22170 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
22171 name and module name must match. For instance, the @code{(my-packages
22172 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
22173 relative to the load path specified with @option{--load-path} or
22174 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
22175 guile, GNU Guile Reference Manual}, for details.}. These package definitions
22176 will not be visible by default. Users can invoke commands such as
22177 @command{guix package} and @command{guix build} with the
22178 @code{-e} option so that they know where to find the package. Better
22179 yet, they can use the
22180 @code{-L} option of these commands to make those modules visible
22181 (@pxref{Invoking guix build, @code{--load-path}}), or define the
22182 @code{GUIX_PACKAGE_PATH} environment variable. This environment
22183 variable makes it easy to extend or customize the distribution and is
22184 honored by all the user interfaces.
22186 @defvr {Environment Variable} GUIX_PACKAGE_PATH
22187 This is a colon-separated list of directories to search for additional
22188 package modules. Directories listed in this variable take precedence
22189 over the own modules of the distribution.
22192 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
22193 each package is built based solely on other packages in the
22194 distribution. The root of this dependency graph is a small set of
22195 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
22196 bootstrap)} module. For more information on bootstrapping,
22197 @pxref{Bootstrapping}.
22199 @node Packaging Guidelines
22200 @section Packaging Guidelines
22202 @cindex packages, creating
22203 The GNU distribution is nascent and may well lack some of your favorite
22204 packages. This section describes how you can help make the distribution
22205 grow. @xref{Contributing}, for additional information on how you can
22208 Free software packages are usually distributed in the form of
22209 @dfn{source code tarballs}---typically @file{tar.gz} files that contain
22210 all the source files. Adding a package to the distribution means
22211 essentially two things: adding a @dfn{recipe} that describes how to
22212 build the package, including a list of other packages required to build
22213 it, and adding @dfn{package metadata} along with that recipe, such as a
22214 description and licensing information.
22216 In Guix all this information is embodied in @dfn{package definitions}.
22217 Package definitions provide a high-level view of the package. They are
22218 written using the syntax of the Scheme programming language; in fact,
22219 for each package we define a variable bound to the package definition,
22220 and export that variable from a module (@pxref{Package Modules}).
22221 However, in-depth Scheme knowledge is @emph{not} a prerequisite for
22222 creating packages. For more information on package definitions,
22223 @pxref{Defining Packages}.
22225 Once a package definition is in place, stored in a file in the Guix
22226 source tree, it can be tested using the @command{guix build} command
22227 (@pxref{Invoking guix build}). For example, assuming the new package is
22228 called @code{gnew}, you may run this command from the Guix build tree
22229 (@pxref{Running Guix Before It Is Installed}):
22232 ./pre-inst-env guix build gnew --keep-failed
22235 Using @code{--keep-failed} makes it easier to debug build failures since
22236 it provides access to the failed build tree. Another useful
22237 command-line option when debugging is @code{--log-file}, to access the
22240 If the package is unknown to the @command{guix} command, it may be that
22241 the source file contains a syntax error, or lacks a @code{define-public}
22242 clause to export the package variable. To figure it out, you may load
22243 the module from Guile to get more information about the actual error:
22246 ./pre-inst-env guile -c '(use-modules (gnu packages gnew))'
22249 Once your package builds correctly, please send us a patch
22250 (@pxref{Contributing}). Well, if you need help, we will be happy to
22251 help you too. Once the patch is committed in the Guix repository, the
22252 new package automatically gets built on the supported platforms by
22253 @url{http://hydra.gnu.org/jobset/gnu/master, our continuous integration
22256 @cindex substituter
22257 Users can obtain the new package definition simply by running
22258 @command{guix pull} (@pxref{Invoking guix pull}). When
22259 @code{hydra.gnu.org} is done building the package, installing the
22260 package automatically downloads binaries from there
22261 (@pxref{Substitutes}). The only place where human intervention is
22262 needed is to review and apply the patch.
22266 * Software Freedom:: What may go into the distribution.
22267 * Package Naming:: What's in a name?
22268 * Version Numbers:: When the name is not enough.
22269 * Synopses and Descriptions:: Helping users find the right package.
22270 * Python Modules:: A touch of British comedy.
22271 * Perl Modules:: Little pearls.
22272 * Java Packages:: Coffee break.
22273 * Fonts:: Fond of fonts.
22276 @node Software Freedom
22277 @subsection Software Freedom
22279 @c Adapted from http://www.gnu.org/philosophy/philosophy.html.
22280 @cindex free software
22281 The GNU operating system has been developed so that users can have
22282 freedom in their computing. GNU is @dfn{free software}, meaning that
22283 users have the @url{http://www.gnu.org/philosophy/free-sw.html,four
22284 essential freedoms}: to run the program, to study and change the program
22285 in source code form, to redistribute exact copies, and to distribute
22286 modified versions. Packages found in the GNU distribution provide only
22287 software that conveys these four freedoms.
22289 In addition, the GNU distribution follow the
22290 @url{http://www.gnu.org/distros/free-system-distribution-guidelines.html,free
22291 software distribution guidelines}. Among other things, these guidelines
22292 reject non-free firmware, recommendations of non-free software, and
22293 discuss ways to deal with trademarks and patents.
22295 Some otherwise free upstream package sources contain a small and optional
22296 subset that violates the above guidelines, for instance because this subset
22297 is itself non-free code. When that happens, the offending items are removed
22298 with appropriate patches or code snippets in the @code{origin} form of the
22299 package (@pxref{Defining Packages}). This way, @code{guix
22300 build --source} returns the ``freed'' source rather than the unmodified
22304 @node Package Naming
22305 @subsection Package Naming
22307 @cindex package name
22308 A package has actually two names associated with it:
22309 First, there is the name of the @emph{Scheme variable}, the one following
22310 @code{define-public}. By this name, the package can be made known in the
22311 Scheme code, for instance as input to another package. Second, there is
22312 the string in the @code{name} field of a package definition. This name
22313 is used by package management commands such as
22314 @command{guix package} and @command{guix build}.
22316 Both are usually the same and correspond to the lowercase conversion of
22317 the project name chosen upstream, with underscores replaced with
22318 hyphens. For instance, GNUnet is available as @code{gnunet}, and
22319 SDL_net as @code{sdl-net}.
22321 We do not add @code{lib} prefixes for library packages, unless these are
22322 already part of the official project name. But @pxref{Python
22323 Modules} and @ref{Perl Modules} for special rules concerning modules for
22324 the Python and Perl languages.
22326 Font package names are handled differently, @pxref{Fonts}.
22329 @node Version Numbers
22330 @subsection Version Numbers
22332 @cindex package version
22333 We usually package only the latest version of a given free software
22334 project. But sometimes, for instance for incompatible library versions,
22335 two (or more) versions of the same package are needed. These require
22336 different Scheme variable names. We use the name as defined
22337 in @ref{Package Naming}
22338 for the most recent version; previous versions use the same name, suffixed
22339 by @code{-} and the smallest prefix of the version number that may
22340 distinguish the two versions.
22342 The name inside the package definition is the same for all versions of a
22343 package and does not contain any version number.
22345 For instance, the versions 2.24.20 and 3.9.12 of GTK+ may be packaged as follows:
22348 (define-public gtk+
22353 (define-public gtk+-2
22356 (version "2.24.20")
22359 If we also wanted GTK+ 3.8.2, this would be packaged as
22361 (define-public gtk+-3.8
22368 @c See <https://lists.gnu.org/archive/html/guix-devel/2016-01/msg00425.html>,
22369 @c for a discussion of what follows.
22370 @cindex version number, for VCS snapshots
22371 Occasionally, we package snapshots of upstream's version control system
22372 (VCS) instead of formal releases. This should remain exceptional,
22373 because it is up to upstream developers to clarify what the stable
22374 release is. Yet, it is sometimes necessary. So, what should we put in
22375 the @code{version} field?
22377 Clearly, we need to make the commit identifier of the VCS snapshot
22378 visible in the version string, but we also need to make sure that the
22379 version string is monotonically increasing so that @command{guix package
22380 --upgrade} can determine which version is newer. Since commit
22381 identifiers, notably with Git, are not monotonically increasing, we add
22382 a revision number that we increase each time we upgrade to a newer
22383 snapshot. The resulting version string looks like this:
22388 | | `-- upstream commit ID
22390 | `--- Guix package revision
22392 latest upstream version
22395 It is a good idea to strip commit identifiers in the @code{version}
22396 field to, say, 7 digits. It avoids an aesthetic annoyance (assuming
22397 aesthetics have a role to play here) as well as problems related to OS
22398 limits such as the maximum shebang length (127 bytes for the Linux
22399 kernel.) It is best to use the full commit identifiers in
22400 @code{origin}s, though, to avoid ambiguities. A typical package
22401 definition may look like this:
22405 (let ((commit "c3f29bc928d5900971f65965feaae59e1272a3f7")
22406 (revision "1")) ;Guix package revision
22408 (version (git-version "0.9" revision commit))
22411 (uri (git-reference
22412 (url "git://example.org/my-package.git")
22414 (sha256 (base32 "1mbikn@dots{}"))
22415 (file-name (git-file-name name version))))
22420 @node Synopses and Descriptions
22421 @subsection Synopses and Descriptions
22423 @cindex package description
22424 @cindex package synopsis
22425 As we have seen before, each package in GNU@tie{}Guix includes a
22426 synopsis and a description (@pxref{Defining Packages}). Synopses and
22427 descriptions are important: They are what @command{guix package
22428 --search} searches, and a crucial piece of information to help users
22429 determine whether a given package suits their needs. Consequently,
22430 packagers should pay attention to what goes into them.
22432 Synopses must start with a capital letter and must not end with a
22433 period. They must not start with ``a'' or ``the'', which usually does
22434 not bring anything; for instance, prefer ``File-frobbing tool'' over ``A
22435 tool that frobs files''. The synopsis should say what the package
22436 is---e.g., ``Core GNU utilities (file, text, shell)''---or what it is
22437 used for---e.g., the synopsis for GNU@tie{}grep is ``Print lines
22438 matching a pattern''.
22440 Keep in mind that the synopsis must be meaningful for a very wide
22441 audience. For example, ``Manipulate alignments in the SAM format''
22442 might make sense for a seasoned bioinformatics researcher, but might be
22443 fairly unhelpful or even misleading to a non-specialized audience. It
22444 is a good idea to come up with a synopsis that gives an idea of the
22445 application domain of the package. In this example, this might give
22446 something like ``Manipulate nucleotide sequence alignments'', which
22447 hopefully gives the user a better idea of whether this is what they are
22450 Descriptions should take between five and ten lines. Use full
22451 sentences, and avoid using acronyms without first introducing them.
22452 Please avoid marketing phrases such as ``world-leading'',
22453 ``industrial-strength'', and ``next-generation'', and avoid superlatives
22454 like ``the most advanced''---they are not helpful to users looking for a
22455 package and may even sound suspicious. Instead, try to be factual,
22456 mentioning use cases and features.
22458 @cindex Texinfo markup, in package descriptions
22459 Descriptions can include Texinfo markup, which is useful to introduce
22460 ornaments such as @code{@@code} or @code{@@dfn}, bullet lists, or
22461 hyperlinks (@pxref{Overview,,, texinfo, GNU Texinfo}). However you
22462 should be careful when using some characters for example @samp{@@} and
22463 curly braces which are the basic special characters in Texinfo
22464 (@pxref{Special Characters,,, texinfo, GNU Texinfo}). User interfaces
22465 such as @command{guix package --show} take care of rendering it
22468 Synopses and descriptions are translated by volunteers
22469 @uref{http://translationproject.org/domain/guix-packages.html, at the
22470 Translation Project} so that as many users as possible can read them in
22471 their native language. User interfaces search them and display them in
22472 the language specified by the current locale.
22474 To allow @command{xgettext} to extract them as translatable strings,
22475 synopses and descriptions @emph{must be literal strings}. This means
22476 that you cannot use @code{string-append} or @code{format} to construct
22482 (synopsis "This is translatable")
22483 (description (string-append "This is " "*not*" " translatable.")))
22486 Translation is a lot of work so, as a packager, please pay even more
22487 attention to your synopses and descriptions as every change may entail
22488 additional work for translators. In order to help them, it is possible
22489 to make recommendations or instructions visible to them by inserting
22490 special comments like this (@pxref{xgettext Invocation,,, gettext, GNU
22494 ;; TRANSLATORS: "X11 resize-and-rotate" should not be translated.
22495 (description "ARandR is designed to provide a simple visual front end
22496 for the X11 resize-and-rotate (RandR) extension. @dots{}")
22500 @node Python Modules
22501 @subsection Python Modules
22504 We currently package Python 2 and Python 3, under the Scheme variable names
22505 @code{python-2} and @code{python} as explained in @ref{Version Numbers}.
22506 To avoid confusion and naming clashes with other programming languages, it
22507 seems desirable that the name of a package for a Python module contains
22508 the word @code{python}.
22510 Some modules are compatible with only one version of Python, others with both.
22511 If the package Foo compiles only with Python 3, we name it
22512 @code{python-foo}; if it compiles only with Python 2, we name it
22513 @code{python2-foo}. If it is compatible with both versions, we create two
22514 packages with the corresponding names.
22516 If a project already contains the word @code{python}, we drop this;
22517 for instance, the module python-dateutil is packaged under the names
22518 @code{python-dateutil} and @code{python2-dateutil}. If the project name
22519 starts with @code{py} (e.g. @code{pytz}), we keep it and prefix it as
22522 @subsubsection Specifying Dependencies
22523 @cindex inputs, for Python packages
22525 Dependency information for Python packages is usually available in the
22526 package source tree, with varying degrees of accuracy: in the
22527 @file{setup.py} file, in @file{requirements.txt}, or in @file{tox.ini}.
22529 Your mission, when writing a recipe for a Python package, is to map
22530 these dependencies to the appropriate type of ``input'' (@pxref{package
22531 Reference, inputs}). Although the @code{pypi} importer normally does a
22532 good job (@pxref{Invoking guix import}), you may want to check the
22533 following check list to determine which dependency goes where.
22538 We currently package Python 2 with @code{setuptools} and @code{pip}
22539 installed like Python 3.4 has per default. Thus you don't need to
22540 specify either of these as an input. @command{guix lint} will warn you
22544 Python dependencies required at run time go into
22545 @code{propagated-inputs}. They are typically defined with the
22546 @code{install_requires} keyword in @file{setup.py}, or in the
22547 @file{requirements.txt} file.
22550 Python packages required only at build time---e.g., those listed with
22551 the @code{setup_requires} keyword in @file{setup.py}---or only for
22552 testing---e.g., those in @code{tests_require}---go into
22553 @code{native-inputs}. The rationale is that (1) they do not need to be
22554 propagated because they are not needed at run time, and (2) in a
22555 cross-compilation context, it's the ``native'' input that we'd want.
22557 Examples are the @code{pytest}, @code{mock}, and @code{nose} test
22558 frameworks. Of course if any of these packages is also required at
22559 run-time, it needs to go to @code{propagated-inputs}.
22562 Anything that does not fall in the previous categories goes to
22563 @code{inputs}, for example programs or C libraries required for building
22564 Python packages containing C extensions.
22567 If a Python package has optional dependencies (@code{extras_require}),
22568 it is up to you to decide whether to add them or not, based on their
22569 usefulness/overhead ratio (@pxref{Submitting Patches, @command{guix
22576 @subsection Perl Modules
22579 Perl programs standing for themselves are named as any other package,
22580 using the lowercase upstream name.
22581 For Perl packages containing a single class, we use the lowercase class name,
22582 replace all occurrences of @code{::} by dashes and prepend the prefix
22584 So the class @code{XML::Parser} becomes @code{perl-xml-parser}.
22585 Modules containing several classes keep their lowercase upstream name and
22586 are also prepended by @code{perl-}. Such modules tend to have the word
22587 @code{perl} somewhere in their name, which gets dropped in favor of the
22588 prefix. For instance, @code{libwww-perl} becomes @code{perl-libwww}.
22591 @node Java Packages
22592 @subsection Java Packages
22595 Java programs standing for themselves are named as any other package,
22596 using the lowercase upstream name.
22598 To avoid confusion and naming clashes with other programming languages,
22599 it is desirable that the name of a package for a Java package is
22600 prefixed with @code{java-}. If a project already contains the word
22601 @code{java}, we drop this; for instance, the package @code{ngsjava} is
22602 packaged under the name @code{java-ngs}.
22604 For Java packages containing a single class or a small class hierarchy,
22605 we use the lowercase class name, replace all occurrences of @code{.} by
22606 dashes and prepend the prefix @code{java-}. So the class
22607 @code{apache.commons.cli} becomes package
22608 @code{java-apache-commons-cli}.
22615 For fonts that are in general not installed by a user for typesetting
22616 purposes, or that are distributed as part of a larger software package,
22617 we rely on the general packaging rules for software; for instance, this
22618 applies to the fonts delivered as part of the X.Org system or fonts that
22619 are part of TeX Live.
22621 To make it easier for a user to search for fonts, names for other packages
22622 containing only fonts are constructed as follows, independently of the
22623 upstream package name.
22625 The name of a package containing only one font family starts with
22626 @code{font-}; it is followed by the foundry name and a dash @code{-}
22627 if the foundry is known, and the font family name, in which spaces are
22628 replaced by dashes (and as usual, all upper case letters are transformed
22630 For example, the Gentium font family by SIL is packaged under the name
22631 @code{font-sil-gentium}.
22633 For a package containing several font families, the name of the collection
22634 is used in the place of the font family name.
22635 For instance, the Liberation fonts consist of three families,
22636 Liberation Sans, Liberation Serif and Liberation Mono.
22637 These could be packaged separately under the names
22638 @code{font-liberation-sans} and so on; but as they are distributed together
22639 under a common name, we prefer to package them together as
22640 @code{font-liberation}.
22642 In the case where several formats of the same font family or font collection
22643 are packaged separately, a short form of the format, prepended by a dash,
22644 is added to the package name. We use @code{-ttf} for TrueType fonts,
22645 @code{-otf} for OpenType fonts and @code{-type1} for PostScript Type 1
22650 @node Bootstrapping
22651 @section Bootstrapping
22653 @c Adapted from the ELS 2013 paper.
22655 @cindex bootstrapping
22657 Bootstrapping in our context refers to how the distribution gets built
22658 ``from nothing''. Remember that the build environment of a derivation
22659 contains nothing but its declared inputs (@pxref{Introduction}). So
22660 there's an obvious chicken-and-egg problem: how does the first package
22661 get built? How does the first compiler get compiled? Note that this is
22662 a question of interest only to the curious hacker, not to the regular
22663 user, so you can shamelessly skip this section if you consider yourself
22664 a ``regular user''.
22666 @cindex bootstrap binaries
22667 The GNU system is primarily made of C code, with libc at its core. The
22668 GNU build system itself assumes the availability of a Bourne shell and
22669 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
22670 `grep'. Furthermore, build programs---programs that run
22671 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
22672 (@pxref{Derivations}). Consequently, to be able to build anything at
22673 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
22674 Binutils, libc, and the other packages mentioned above---the
22675 @dfn{bootstrap binaries}.
22677 These bootstrap binaries are ``taken for granted'', though we can also
22678 re-create them if needed (more on that later).
22680 @unnumberedsubsec Preparing to Use the Bootstrap Binaries
22682 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
22683 @c large image, it's hard to scroll. Oh well.
22684 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
22686 The figure above shows the very beginning of the dependency graph of the
22687 distribution, corresponding to the package definitions of the @code{(gnu
22688 packages bootstrap)} module. A similar figure can be generated with
22689 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
22692 guix graph -t derivation \
22693 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
22697 At this level of detail, things are
22698 slightly complex. First, Guile itself consists of an ELF executable,
22699 along with many source and compiled Scheme files that are dynamically
22700 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
22701 tarball shown in this graph. This tarball is part of Guix's ``source''
22702 distribution, and gets inserted into the store with @code{add-to-store}
22703 (@pxref{The Store}).
22705 But how do we write a derivation that unpacks this tarball and adds it
22706 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
22707 derivation---the first one that gets built---uses @code{bash} as its
22708 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
22709 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
22710 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
22711 the Guix source distribution, whose sole purpose is to allow the Guile
22712 tarball to be unpacked.
22714 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
22715 Guile that can be used to run subsequent build programs. Its first task
22716 is to download tarballs containing the other pre-built binaries---this
22717 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
22718 @code{ftp-client.scm} are used for this purpose. The
22719 @code{module-import.drv} derivations import those modules in a directory
22720 in the store, using the original layout. The
22721 @code{module-import-compiled.drv} derivations compile those modules, and
22722 write them in an output directory with the right layout. This
22723 corresponds to the @code{#:modules} argument of
22724 @code{build-expression->derivation} (@pxref{Derivations}).
22726 Finally, the various tarballs are unpacked by the
22727 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
22728 etc., at which point we have a working C tool chain.
22731 @unnumberedsubsec Building the Build Tools
22733 Bootstrapping is complete when we have a full tool chain that does not
22734 depend on the pre-built bootstrap tools discussed above. This
22735 no-dependency requirement is verified by checking whether the files of
22736 the final tool chain contain references to the @file{/gnu/store}
22737 directories of the bootstrap inputs. The process that leads to this
22738 ``final'' tool chain is described by the package definitions found in
22739 the @code{(gnu packages commencement)} module.
22741 The @command{guix graph} command allows us to ``zoom out'' compared to
22742 the graph above, by looking at the level of package objects instead of
22743 individual derivations---remember that a package may translate to
22744 several derivations, typically one derivation to download its source,
22745 one to build the Guile modules it needs, and one to actually build the
22746 package from source. The command:
22749 guix graph -t bag \
22750 -e '(@@@@ (gnu packages commencement)
22751 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
22755 produces the dependency graph leading to the ``final'' C
22756 library@footnote{You may notice the @code{glibc-intermediate} label,
22757 suggesting that it is not @emph{quite} final, but as a good
22758 approximation, we will consider it final.}, depicted below.
22760 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
22762 @c See <http://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
22763 The first tool that gets built with the bootstrap binaries is
22764 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
22765 for all the following packages. From there Findutils and Diffutils get
22768 Then come the first-stage Binutils and GCC, built as pseudo cross
22769 tools---i.e., with @code{--target} equal to @code{--host}. They are
22770 used to build libc. Thanks to this cross-build trick, this libc is
22771 guaranteed not to hold any reference to the initial tool chain.
22773 From there the final Binutils and GCC (not shown above) are built.
22775 from the final Binutils, and links programs against the just-built libc.
22776 This tool chain is used to build the other packages used by Guix and by
22777 the GNU Build System: Guile, Bash, Coreutils, etc.
22779 And voilà! At this point we have the complete set of build tools that
22780 the GNU Build System expects. These are in the @code{%final-inputs}
22781 variable of the @code{(gnu packages commencement)} module, and are
22782 implicitly used by any package that uses @code{gnu-build-system}
22783 (@pxref{Build Systems, @code{gnu-build-system}}).
22786 @unnumberedsubsec Building the Bootstrap Binaries
22788 @cindex bootstrap binaries
22789 Because the final tool chain does not depend on the bootstrap binaries,
22790 those rarely need to be updated. Nevertheless, it is useful to have an
22791 automated way to produce them, should an update occur, and this is what
22792 the @code{(gnu packages make-bootstrap)} module provides.
22794 The following command builds the tarballs containing the bootstrap
22795 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
22796 of Coreutils and other basic command-line tools):
22799 guix build bootstrap-tarballs
22802 The generated tarballs are those that should be referred to in the
22803 @code{(gnu packages bootstrap)} module mentioned at the beginning of
22806 Still here? Then perhaps by now you've started to wonder: when do we
22807 reach a fixed point? That is an interesting question! The answer is
22808 unknown, but if you would like to investigate further (and have
22809 significant computational and storage resources to do so), then let us
22812 @unnumberedsubsec Reducing the Set of Bootstrap Binaries
22814 Our bootstrap binaries currently include GCC, Guile, etc. That's a lot
22815 of binary code! Why is that a problem? It's a problem because these
22816 big chunks of binary code are practically non-auditable, which makes it
22817 hard to establish what source code produced them. Every unauditable
22818 binary also leaves us vulnerable to compiler backdoors as described by
22819 Ken Thompson in the 1984 paper @emph{Reflections on Trusting Trust}.
22821 This is mitigated by the fact that our bootstrap binaries were generated
22822 from an earlier Guix revision. Nevertheless it lacks the level of
22823 transparency that we get in the rest of the package dependency graph,
22824 where Guix always gives us a source-to-binary mapping. Thus, our goal
22825 is to reduce the set of bootstrap binaries to the bare minimum.
22827 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
22828 on-going projects to do that. One of these is about replacing the
22829 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
22830 of increasing complexity, which could be built from source starting from
22831 a simple and auditable assembler. Your help is welcome!
22835 @section Porting to a New Platform
22837 As discussed above, the GNU distribution is self-contained, and
22838 self-containment is achieved by relying on pre-built ``bootstrap
22839 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
22840 operating system kernel, CPU architecture, and application binary
22841 interface (ABI). Thus, to port the distribution to a platform that is
22842 not yet supported, one must build those bootstrap binaries, and update
22843 the @code{(gnu packages bootstrap)} module to use them on that platform.
22845 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
22846 When everything goes well, and assuming the GNU tool chain supports the
22847 target platform, this can be as simple as running a command like this
22851 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
22854 For this to work, the @code{glibc-dynamic-linker} procedure in
22855 @code{(gnu packages bootstrap)} must be augmented to return the right
22856 file name for libc's dynamic linker on that platform; likewise,
22857 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
22858 taught about the new platform.
22860 Once these are built, the @code{(gnu packages bootstrap)} module needs
22861 to be updated to refer to these binaries on the target platform. That
22862 is, the hashes and URLs of the bootstrap tarballs for the new platform
22863 must be added alongside those of the currently supported platforms. The
22864 bootstrap Guile tarball is treated specially: it is expected to be
22865 available locally, and @file{gnu/local.mk} has rules do download it for
22866 the supported architectures; a rule for the new platform must be added
22869 In practice, there may be some complications. First, it may be that the
22870 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
22871 above) is not recognized by all the GNU tools. Typically, glibc
22872 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
22873 configure flag (see @code{gcc.scm} for examples of how to handle this).
22874 Second, some of the required packages could fail to build for that
22875 platform. Lastly, the generated binaries could be broken for some
22878 @c *********************************************************************
22879 @include contributing.texi
22881 @c *********************************************************************
22882 @node Acknowledgments
22883 @chapter Acknowledgments
22885 Guix is based on the @uref{http://nixos.org/nix/, Nix package manager},
22886 which was designed and
22887 implemented by Eelco Dolstra, with contributions from other people (see
22888 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
22889 management, and promoted unprecedented features, such as transactional
22890 package upgrades and rollbacks, per-user profiles, and referentially
22891 transparent build processes. Without this work, Guix would not exist.
22893 The Nix-based software distributions, Nixpkgs and NixOS, have also been
22894 an inspiration for Guix.
22896 GNU@tie{}Guix itself is a collective work with contributions from a
22897 number of people. See the @file{AUTHORS} file in Guix for more
22898 information on these fine people. The @file{THANKS} file lists people
22899 who have helped by reporting bugs, taking care of the infrastructure,
22900 providing artwork and themes, making suggestions, and more---thank you!
22903 @c *********************************************************************
22904 @node GNU Free Documentation License
22905 @appendix GNU Free Documentation License
22906 @cindex license, GNU Free Documentation License
22907 @include fdl-1.3.texi
22909 @c *********************************************************************
22910 @node Concept Index
22911 @unnumbered Concept Index
22914 @node Programming Index
22915 @unnumbered Programming Index
22916 @syncodeindex tp fn
22917 @syncodeindex vr fn
22922 @c Local Variables:
22923 @c ispell-local-dictionary: "american";