6 @documentencoding UTF-8
7 @settitle GNU Guix Reference Manual
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16 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017 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 Ricardo Wurmus@*
25 Copyright @copyright{} 2016 Ben Woodcroft@*
26 Copyright @copyright{} 2016, 2017 Chris Marusich@*
27 Copyright @copyright{} 2016, 2017 Efraim Flashner@*
28 Copyright @copyright{} 2016 John Darrington@*
29 Copyright @copyright{} 2016 ng0@*
30 Copyright @copyright{} 2016, 2017 Jan Nieuwenhuizen@*
31 Copyright @copyright{} 2016 Julien Lepiller@*
32 Copyright @copyright{} 2016 Alex ter Weele@*
33 Copyright @copyright{} 2017 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 Marius Bakke@*
41 Copyright @copyright{} 2017 Hartmut Goebel@*
42 Copyright @copyright{} 2017 Maxim Cournoyer@*
43 Copyright @copyright{} 2017 Tobias Geerinckx-Rice@*
44 Copyright @copyright{} 2017 George Clemmer@*
45 Copyright @copyright{} 2017 Andy Wingo
47 Permission is granted to copy, distribute and/or modify this document
48 under the terms of the GNU Free Documentation License, Version 1.3 or
49 any later version published by the Free Software Foundation; with no
50 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
51 copy of the license is included in the section entitled ``GNU Free
52 Documentation License''.
55 @dircategory System administration
57 * Guix: (guix). Manage installed software and system configuration.
58 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
59 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
60 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
61 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
64 @dircategory Software development
66 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
67 * guix build: (guix)Invoking guix build. Building packages.
68 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
72 @title GNU Guix Reference Manual
73 @subtitle Using the GNU Guix Functional Package Manager
74 @author The GNU Guix Developers
77 @vskip 0pt plus 1filll
78 Edition @value{EDITION} @*
86 @c *********************************************************************
90 This document describes GNU Guix version @value{VERSION}, a functional
91 package management tool written for the GNU system.
94 * Introduction:: What is Guix about?
95 * Installation:: Installing Guix.
96 * Package Management:: Package installation, upgrade, etc.
97 * Programming Interface:: Using Guix in Scheme.
98 * Utilities:: Package management commands.
99 * GNU Distribution:: Software for your friendly GNU system.
100 * Contributing:: Your help needed!
102 * Acknowledgments:: Thanks!
103 * GNU Free Documentation License:: The license of this manual.
104 * Concept Index:: Concepts.
105 * Programming Index:: Data types, functions, and variables.
108 --- The Detailed Node Listing ---
112 * Binary Installation:: Getting Guix running in no time!
113 * Requirements:: Software needed to build and run Guix.
114 * Running the Test Suite:: Testing Guix.
115 * Setting Up the Daemon:: Preparing the build daemon's environment.
116 * Invoking guix-daemon:: Running the build daemon.
117 * Application Setup:: Application-specific setup.
119 Setting Up the Daemon
121 * Build Environment Setup:: Preparing the isolated build environment.
122 * Daemon Offload Setup:: Offloading builds to remote machines.
126 * Features:: How Guix will make your life brighter.
127 * Invoking guix package:: Package installation, removal, etc.
128 * Substitutes:: Downloading pre-built binaries.
129 * Packages with Multiple Outputs:: Single source package, multiple outputs.
130 * Invoking guix gc:: Running the garbage collector.
131 * Invoking guix pull:: Fetching the latest Guix and distribution.
132 * Invoking guix pack:: Creating software bundles.
133 * Invoking guix archive:: Exporting and importing store files.
137 * Official Substitute Server:: One particular source of substitutes.
138 * Substitute Server Authorization:: How to enable or disable substitutes.
139 * Substitute Authentication:: How Guix verifies substitutes.
140 * Proxy Settings:: How to get substitutes via proxy.
141 * Substitution Failure:: What happens when substitution fails.
142 * On Trusting Binaries:: How can you trust that binary blob?
144 Programming Interface
146 * Defining Packages:: Defining new packages.
147 * Build Systems:: Specifying how packages are built.
148 * The Store:: Manipulating the package store.
149 * Derivations:: Low-level interface to package derivations.
150 * The Store Monad:: Purely functional interface to the store.
151 * G-Expressions:: Manipulating build expressions.
155 * package Reference :: The package data type.
156 * origin Reference:: The origin data type.
160 * Invoking guix build:: Building packages from the command line.
161 * Invoking guix edit:: Editing package definitions.
162 * Invoking guix download:: Downloading a file and printing its hash.
163 * Invoking guix hash:: Computing the cryptographic hash of a file.
164 * Invoking guix import:: Importing package definitions.
165 * Invoking guix refresh:: Updating package definitions.
166 * Invoking guix lint:: Finding errors in package definitions.
167 * Invoking guix size:: Profiling disk usage.
168 * Invoking guix graph:: Visualizing the graph of packages.
169 * Invoking guix environment:: Setting up development environments.
170 * Invoking guix publish:: Sharing substitutes.
171 * Invoking guix challenge:: Challenging substitute servers.
172 * Invoking guix copy:: Copying to and from a remote store.
173 * Invoking guix container:: Process isolation.
174 * Invoking guix weather:: Assessing substitute availability.
176 Invoking @command{guix build}
178 * Common Build Options:: Build options for most commands.
179 * Package Transformation Options:: Creating variants of packages.
180 * Additional Build Options:: Options specific to 'guix build'.
181 * Debugging Build Failures:: Real life packaging experience.
185 * System Installation:: Installing the whole operating system.
186 * System Configuration:: Configuring the operating system.
187 * Documentation:: Browsing software user manuals.
188 * Installing Debugging Files:: Feeding the debugger.
189 * Security Updates:: Deploying security fixes quickly.
190 * Package Modules:: Packages from the programmer's viewpoint.
191 * Packaging Guidelines:: Growing the distribution.
192 * Bootstrapping:: GNU/Linux built from scratch.
193 * Porting:: Targeting another platform or kernel.
197 * Limitations:: What you can expect.
198 * Hardware Considerations:: Supported hardware.
199 * USB Stick Installation:: Preparing the installation medium.
200 * Preparing for Installation:: Networking, partitioning, etc.
201 * Proceeding with the Installation:: The real thing.
202 * Installing GuixSD in a VM:: GuixSD playground.
203 * Building the Installation Image:: How this comes to be.
207 * Using the Configuration System:: Customizing your GNU system.
208 * operating-system Reference:: Detail of operating-system declarations.
209 * File Systems:: Configuring file system mounts.
210 * Mapped Devices:: Block device extra processing.
211 * User Accounts:: Specifying user accounts.
212 * Locales:: Language and cultural convention settings.
213 * Services:: Specifying system services.
214 * Setuid Programs:: Programs running with root privileges.
215 * X.509 Certificates:: Authenticating HTTPS servers.
216 * Name Service Switch:: Configuring libc's name service switch.
217 * Initial RAM Disk:: Linux-Libre bootstrapping.
218 * Bootloader Configuration:: Configuring the boot loader.
219 * Invoking guix system:: Instantiating a system configuration.
220 * Running GuixSD in a VM:: How to run GuixSD in a virtual machine.
221 * Defining Services:: Adding new service definitions.
225 * Base Services:: Essential system services.
226 * Scheduled Job Execution:: The mcron service.
227 * Log Rotation:: The rottlog service.
228 * Networking Services:: Network setup, SSH daemon, etc.
229 * X Window:: Graphical display.
230 * Printing Services:: Local and remote printer support.
231 * Desktop Services:: D-Bus and desktop services.
232 * Database Services:: SQL databases, key-value stores, etc.
233 * Mail Services:: IMAP, POP3, SMTP, and all that.
234 * Messaging Services:: Messaging services.
235 * Telephony Services:: Telephony services.
236 * Monitoring Services:: Monitoring services.
237 * Kerberos Services:: Kerberos services.
238 * Web Services:: Web servers.
239 * Certificate Services:: TLS certificates via Let's Encrypt.
240 * DNS Services:: DNS daemons.
241 * VPN Services:: VPN daemons.
242 * Network File System:: NFS related services.
243 * Continuous Integration:: The Cuirass service.
244 * Power management Services:: The TLP tool.
245 * Audio Services:: The MPD.
246 * Virtualization Services:: Virtualization services.
247 * Version Control Services:: Providing remote access to Git repositories.
248 * Miscellaneous Services:: Other services.
252 * Service Composition:: The model for composing services.
253 * Service Types and Services:: Types and services.
254 * Service Reference:: API reference.
255 * Shepherd Services:: A particular type of service.
259 * Software Freedom:: What may go into the distribution.
260 * Package Naming:: What's in a name?
261 * Version Numbers:: When the name is not enough.
262 * Synopses and Descriptions:: Helping users find the right package.
263 * Python Modules:: A touch of British comedy.
264 * Perl Modules:: Little pearls.
265 * Java Packages:: Coffee break.
266 * Fonts:: Fond of fonts.
270 * Building from Git:: The latest and greatest.
271 * Running Guix Before It Is Installed:: Hacker tricks.
272 * The Perfect Setup:: The right tools.
273 * Coding Style:: Hygiene of the contributor.
274 * Submitting Patches:: Share your work.
278 * Programming Paradigm:: How to compose your elements.
279 * Modules:: Where to store your code?
280 * Data Types and Pattern Matching:: Implementing data structures.
281 * Formatting Code:: Writing conventions.
286 @c *********************************************************************
288 @chapter Introduction
291 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
292 using the international phonetic alphabet (IPA).} is a package
293 management tool for the GNU system. Guix makes it easy for unprivileged
294 users to install, upgrade, or remove packages, to roll back to a
295 previous package set, to build packages from source, and generally
296 assists with the creation and maintenance of software environments.
298 @cindex user interfaces
299 Guix provides a command-line package management interface
300 (@pxref{Invoking guix package}), a set of command-line utilities
301 (@pxref{Utilities}), as well as Scheme programming interfaces
302 (@pxref{Programming Interface}).
304 Its @dfn{build daemon} is responsible for building packages on behalf of
305 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
306 binaries from authorized sources (@pxref{Substitutes}).
308 @cindex extensibility of the distribution
309 @cindex customization, of packages
310 Guix includes package definitions for many GNU and non-GNU packages, all
311 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
312 user's computing freedom}. It is @emph{extensible}: users can write
313 their own package definitions (@pxref{Defining Packages}) and make them
314 available as independent package modules (@pxref{Package Modules}). It
315 is also @emph{customizable}: users can @emph{derive} specialized package
316 definitions from existing ones, including from the command line
317 (@pxref{Package Transformation Options}).
319 @cindex Guix System Distribution
321 You can install GNU@tie{}Guix on top of an existing GNU/Linux system
322 where it complements the available tools without interference
323 (@pxref{Installation}), or you can use it as part of the standalone
324 @dfn{Guix System Distribution} or GuixSD (@pxref{GNU Distribution}).
325 With GNU@tie{}GuixSD, you @emph{declare} all aspects of the operating
326 system configuration and Guix takes care of instantiating the
327 configuration in a transactional, reproducible, and stateless fashion
328 (@pxref{System Configuration}).
330 @cindex functional package management
331 Under the hood, Guix implements the @dfn{functional package management}
332 discipline pioneered by Nix (@pxref{Acknowledgments}).
333 In Guix, the package build and installation process is seen
334 as a @emph{function}, in the mathematical sense. That function takes inputs,
335 such as build scripts, a compiler, and libraries, and
336 returns an installed package. As a pure function, its result depends
337 solely on its inputs---for instance, it cannot refer to software or
338 scripts that were not explicitly passed as inputs. A build function
339 always produces the same result when passed a given set of inputs. It
340 cannot alter the environment of the running system in
341 any way; for instance, it cannot create, modify, or delete files outside
342 of its build and installation directories. This is achieved by running
343 build processes in isolated environments (or @dfn{containers}), where only their
344 explicit inputs are visible.
347 The result of package build functions is @dfn{cached} in the file
348 system, in a special directory called @dfn{the store} (@pxref{The
349 Store}). Each package is installed in a directory of its own in the
350 store---by default under @file{/gnu/store}. The directory name contains
351 a hash of all the inputs used to build that package; thus, changing an
352 input yields a different directory name.
354 This approach is the foundation for the salient features of Guix: support
355 for transactional package upgrade and rollback, per-user installation, and
356 garbage collection of packages (@pxref{Features}).
359 @c *********************************************************************
361 @chapter Installation
363 @cindex installing Guix
364 GNU Guix is available for download from its website at
365 @url{http://www.gnu.org/software/guix/}. This section describes the
366 software requirements of Guix, as well as how to install it and get
369 Note that this section is concerned with the installation of the package
370 manager, which can be done on top of a running GNU/Linux system. If,
371 instead, you want to install the complete GNU operating system,
372 @pxref{System Installation}.
374 @cindex foreign distro
375 When installed on a running GNU/Linux system---thereafter called a
376 @dfn{foreign distro}---GNU@tie{}Guix complements the available tools
377 without interference. Its data lives exclusively in two directories,
378 usually @file{/gnu/store} and @file{/var/guix}; other files on your
379 system, such as @file{/etc}, are left untouched.
381 Once installed, Guix can be updated by running @command{guix pull}
382 (@pxref{Invoking guix pull}).
385 * Binary Installation:: Getting Guix running in no time!
386 * Requirements:: Software needed to build and run Guix.
387 * Running the Test Suite:: Testing Guix.
388 * Setting Up the Daemon:: Preparing the build daemon's environment.
389 * Invoking guix-daemon:: Running the build daemon.
390 * Application Setup:: Application-specific setup.
393 @node Binary Installation
394 @section Binary Installation
396 @cindex installing Guix from binaries
397 This section describes how to install Guix on an arbitrary system from a
398 self-contained tarball providing binaries for Guix and for all its
399 dependencies. This is often quicker than installing from source, which
400 is described in the next sections. The only requirement is to have
403 Installing goes along these lines:
407 @cindex downloading Guix binary
408 Download the binary tarball from
409 @indicateurl{ftp://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz},
410 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
411 already running the kernel Linux, and so on.
413 @c The following is somewhat duplicated in ``System Installation''.
414 Make sure to download the associated @file{.sig} file and to verify the
415 authenticity of the tarball against it, along these lines:
418 $ wget ftp://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
419 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
422 If that command fails because you do not have the required public key,
423 then run this command to import it:
426 $ gpg --keyserver pgp.mit.edu --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
430 and rerun the @code{gpg --verify} command.
431 @c end authentication part
438 # tar --warning=no-timestamp -xf \
439 guix-binary-@value{VERSION}.@var{system}.tar.xz
440 # mv var/guix /var/ && mv gnu /
443 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
444 The latter contains a ready-to-use profile for @code{root} (see next
447 Do @emph{not} unpack the tarball on a working Guix system since that
448 would overwrite its own essential files.
450 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
451 not emit warnings about ``implausibly old time stamps'' (such
452 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
454 They stem from the fact that all the
455 files in the archive have their modification time set to zero (which
456 means January 1st, 1970.) This is done on purpose to make sure the
457 archive content is independent of its creation time, thus making it
461 Make @code{root}'s profile available under @file{~/.guix-profile}:
464 # ln -sf /var/guix/profiles/per-user/root/guix-profile \
468 Source @file{etc/profile} to augment @code{PATH} and other relevant
469 environment variables:
472 # GUIX_PROFILE=$HOME/.guix-profile ; \
473 source $GUIX_PROFILE/etc/profile
477 Create the group and user accounts for build users as explained below
478 (@pxref{Build Environment Setup}).
481 Run the daemon, and set it to automatically start on boot.
483 If your host distro uses the systemd init system, this can be achieved
486 @c Versions of systemd that supported symlinked service files are not
487 @c yet widely deployed, so we should suggest that users copy the service
490 @c See this thread for more information:
491 @c http://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
494 # cp ~root/.guix-profile/lib/systemd/system/guix-daemon.service \
496 # systemctl start guix-daemon && systemctl enable guix-daemon
499 If your host distro uses the Upstart init system:
502 # initctl reload-configuration
503 # cp ~root/.guix-profile/lib/upstart/system/guix-daemon.conf /etc/init/
507 Otherwise, you can still start the daemon manually with:
510 # ~root/.guix-profile/bin/guix-daemon --build-users-group=guixbuild
514 Make the @command{guix} command available to other users on the machine,
518 # mkdir -p /usr/local/bin
520 # ln -s /var/guix/profiles/per-user/root/guix-profile/bin/guix
523 It is also a good idea to make the Info version of this manual available
527 # mkdir -p /usr/local/share/info
528 # cd /usr/local/share/info
529 # for i in /var/guix/profiles/per-user/root/guix-profile/share/info/* ;
533 That way, assuming @file{/usr/local/share/info} is in the search path,
534 running @command{info guix} will open this manual (@pxref{Other Info
535 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
539 @cindex substitutes, authorization thereof
540 To use substitutes from @code{hydra.gnu.org} or one of its mirrors
541 (@pxref{Substitutes}), authorize them:
544 # guix archive --authorize < ~root/.guix-profile/share/guix/hydra.gnu.org.pub
548 Each user may need to perform a few additional steps to make their Guix
549 environment ready for use, @pxref{Application Setup}.
552 Voilà, the installation is complete!
554 You can confirm that Guix is working by installing a sample package into
558 # guix package -i hello
561 The @code{guix} package must remain available in @code{root}'s profile,
562 or it would become subject to garbage collection---in which case you
563 would find yourself badly handicapped by the lack of the @command{guix}
564 command. In other words, do not remove @code{guix} by running
565 @code{guix package -r guix}.
567 The binary installation tarball can be (re)produced and verified simply
568 by running the following command in the Guix source tree:
571 make guix-binary.@var{system}.tar.xz
575 ... which, in turn, runs:
578 guix pack -s @var{system} --localstatedir guix
581 @xref{Invoking guix pack}, for more info on this handy tool.
584 @section Requirements
586 This section lists requirements when building Guix from source. The
587 build procedure for Guix is the same as for other GNU software, and is
588 not covered here. Please see the files @file{README} and @file{INSTALL}
589 in the Guix source tree for additional details.
591 GNU Guix depends on the following packages:
594 @item @url{http://gnu.org/software/guile/, GNU Guile}, version 2.0.9 or
595 later, including 2.2.x;
596 @item @url{http://gnupg.org/, GNU libgcrypt};
598 @uref{http://gnutls.org/, GnuTLS}, specifically its Guile bindings
599 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
600 Guile,, gnutls-guile, GnuTLS-Guile});
602 @c FIXME: Specify a version number once a release has been made.
603 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
605 @item @url{http://www.gnu.org/software/make/, GNU Make}.
608 The following dependencies are optional:
613 @url{http://savannah.nongnu.org/projects/guile-json/, Guile-JSON} will
614 allow you to use the @command{guix import pypi} command (@pxref{Invoking
615 guix import}). It is of
616 interest primarily for developers and not for casual users.
619 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
620 Support for build offloading (@pxref{Daemon Offload Setup}) and
621 @command{guix copy} (@pxref{Invoking guix copy}) depends on
622 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
623 version 0.10.2 or later.
626 When @url{http://zlib.net, zlib} is available, @command{guix publish}
627 can compress build byproducts (@pxref{Invoking guix publish}).
630 Unless @code{--disable-daemon} was passed to @command{configure}, the
631 following packages are also needed:
634 @item @url{http://sqlite.org, SQLite 3};
635 @item @url{http://www.bzip.org, libbz2};
636 @item @url{http://gcc.gnu.org, GCC's g++}, with support for the
640 @cindex state directory
641 When configuring Guix on a system that already has a Guix installation,
642 be sure to specify the same state directory as the existing installation
643 using the @code{--localstatedir} option of the @command{configure}
644 script (@pxref{Directory Variables, @code{localstatedir},, standards,
645 GNU Coding Standards}). The @command{configure} script protects against
646 unintended misconfiguration of @var{localstatedir} so you do not
647 inadvertently corrupt your store (@pxref{The Store}).
649 @cindex Nix, compatibility
650 When a working installation of @url{http://nixos.org/nix/, the Nix package
651 manager} is available, you
652 can instead configure Guix with @code{--disable-daemon}. In that case,
653 Nix replaces the three dependencies above.
655 Guix is compatible with Nix, so it is possible to share the same store
656 between both. To do so, you must pass @command{configure} not only the
657 same @code{--with-store-dir} value, but also the same
658 @code{--localstatedir} value. The latter is essential because it
659 specifies where the database that stores metadata about the store is
660 located, among other things. The default values for Nix are
661 @code{--with-store-dir=/nix/store} and @code{--localstatedir=/nix/var}.
662 Note that @code{--disable-daemon} is not required if
663 your goal is to share the store with Nix.
665 @node Running the Test Suite
666 @section Running the Test Suite
669 After a successful @command{configure} and @code{make} run, it is a good
670 idea to run the test suite. It can help catch issues with the setup or
671 environment, or bugs in Guix itself---and really, reporting test
672 failures is a good way to help improve the software. To run the test
679 Test cases can run in parallel: you can use the @code{-j} option of
680 GNU@tie{}make to speed things up. The first run may take a few minutes
681 on a recent machine; subsequent runs will be faster because the store
682 that is created for test purposes will already have various things in
685 It is also possible to run a subset of the tests by defining the
686 @code{TESTS} makefile variable as in this example:
689 make check TESTS="tests/store.scm tests/cpio.scm"
692 By default, tests results are displayed at a file level. In order to
693 see the details of every individual test cases, it is possible to define
694 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
697 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
700 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
701 @file{test-suite.log} file. Please specify the Guix version being used
702 as well as version numbers of the dependencies (@pxref{Requirements}) in
705 Guix also comes with a whole-system test suite that tests complete
706 GuixSD operating system instances. It can only run on systems where
707 Guix is already installed, using:
714 or, again, by defining @code{TESTS} to select a subset of tests to run:
717 make check-system TESTS="basic mcron"
720 These system tests are defined in the @code{(gnu tests @dots{})}
721 modules. They work by running the operating systems under test with
722 lightweight instrumentation in a virtual machine (VM). They can be
723 computationally intensive or rather cheap, depending on whether
724 substitutes are available for their dependencies (@pxref{Substitutes}).
725 Some of them require a lot of storage space to hold VM images.
727 Again in case of test failures, please send @email{bug-guix@@gnu.org}
730 @node Setting Up the Daemon
731 @section Setting Up the Daemon
734 Operations such as building a package or running the garbage collector
735 are all performed by a specialized process, the @dfn{build daemon}, on
736 behalf of clients. Only the daemon may access the store and its
737 associated database. Thus, any operation that manipulates the store
738 goes through the daemon. For instance, command-line tools such as
739 @command{guix package} and @command{guix build} communicate with the
740 daemon (@i{via} remote procedure calls) to instruct it what to do.
742 The following sections explain how to prepare the build daemon's
743 environment. See also @ref{Substitutes}, for information on how to allow
744 the daemon to download pre-built binaries.
747 * Build Environment Setup:: Preparing the isolated build environment.
748 * Daemon Offload Setup:: Offloading builds to remote machines.
751 @node Build Environment Setup
752 @subsection Build Environment Setup
754 @cindex build environment
755 In a standard multi-user setup, Guix and its daemon---the
756 @command{guix-daemon} program---are installed by the system
757 administrator; @file{/gnu/store} is owned by @code{root} and
758 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
759 Guix tools to build packages or otherwise access the store, and the
760 daemon will do it on their behalf, ensuring that the store is kept in a
761 consistent state, and allowing built packages to be shared among users.
764 When @command{guix-daemon} runs as @code{root}, you may not want package
765 build processes themselves to run as @code{root} too, for obvious
766 security reasons. To avoid that, a special pool of @dfn{build users}
767 should be created for use by build processes started by the daemon.
768 These build users need not have a shell and a home directory: they will
769 just be used when the daemon drops @code{root} privileges in build
770 processes. Having several such users allows the daemon to launch
771 distinct build processes under separate UIDs, which guarantees that they
772 do not interfere with each other---an essential feature since builds are
773 regarded as pure functions (@pxref{Introduction}).
775 On a GNU/Linux system, a build user pool may be created like this (using
776 Bash syntax and the @code{shadow} commands):
778 @c See http://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
779 @c for why `-G' is needed.
781 # groupadd --system guixbuild
782 # for i in `seq -w 1 10`;
784 useradd -g guixbuild -G guixbuild \
785 -d /var/empty -s `which nologin` \
786 -c "Guix build user $i" --system \
792 The number of build users determines how many build jobs may run in
793 parallel, as specified by the @option{--max-jobs} option
794 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
795 @command{guix system vm} and related commands, you may need to add the
796 build users to the @code{kvm} group so they can access @file{/dev/kvm},
797 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
798 (@pxref{Invoking guix system}).
800 The @code{guix-daemon} program may then be run as @code{root} with the
801 following command@footnote{If your machine uses the systemd init system,
802 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
803 file in @file{/etc/systemd/system} will ensure that
804 @command{guix-daemon} is automatically started. Similarly, if your
805 machine uses the Upstart init system, drop the
806 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
807 file in @file{/etc/init}.}:
810 # guix-daemon --build-users-group=guixbuild
815 This way, the daemon starts build processes in a chroot, under one of
816 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
817 environment contains nothing but:
819 @c Keep this list in sync with libstore/build.cc! -----------------------
822 a minimal @code{/dev} directory, created mostly independently from the
823 host @code{/dev}@footnote{``Mostly'', because while the set of files
824 that appear in the chroot's @code{/dev} is fixed, most of these files
825 can only be created if the host has them.};
828 the @code{/proc} directory; it only shows the processes of the container
829 since a separate PID name space is used;
832 @file{/etc/passwd} with an entry for the current user and an entry for
836 @file{/etc/group} with an entry for the user's group;
839 @file{/etc/hosts} with an entry that maps @code{localhost} to
843 a writable @file{/tmp} directory.
846 You can influence the directory where the daemon stores build trees
847 @i{via} the @code{TMPDIR} environment variable. However, the build tree
848 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
849 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
850 This way, the value of @code{TMPDIR} does not leak inside build
851 environments, which avoids discrepancies in cases where build processes
852 capture the name of their build tree.
855 The daemon also honors the @code{http_proxy} environment variable for
856 HTTP downloads it performs, be it for fixed-output derivations
857 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
859 If you are installing Guix as an unprivileged user, it is still possible
860 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
861 However, build processes will not be isolated from one another, and not
862 from the rest of the system. Thus, build processes may interfere with
863 each other, and may access programs, libraries, and other files
864 available on the system---making it much harder to view them as
865 @emph{pure} functions.
868 @node Daemon Offload Setup
869 @subsection Using the Offload Facility
873 When desired, the build daemon can @dfn{offload} derivation builds to
874 other machines running Guix, using the @code{offload} @dfn{build
875 hook}@footnote{This feature is available only when
876 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
878 feature is enabled, a list of user-specified build machines is read from
879 @file{/etc/guix/machines.scm}; every time a build is requested, for
880 instance via @code{guix build}, the daemon attempts to offload it to one
881 of the machines that satisfy the constraints of the derivation, in
882 particular its system type---e.g., @file{x86_64-linux}. Missing
883 prerequisites for the build are copied over SSH to the target machine,
884 which then proceeds with the build; upon success the output(s) of the
885 build are copied back to the initial machine.
887 The @file{/etc/guix/machines.scm} file typically looks like this:
891 (name "eightysix.example.org")
892 (system "x86_64-linux")
893 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
895 (speed 2.)) ;incredibly fast!
898 (name "meeps.example.org")
899 (system "mips64el-linux")
900 (host-key "ssh-rsa AAAAB3Nza@dots{}")
903 (string-append (getenv "HOME")
904 "/.ssh/identity-for-guix"))))
908 In the example above we specify a list of two build machines, one for
909 the @code{x86_64} architecture and one for the @code{mips64el}
912 In fact, this file is---not surprisingly!---a Scheme file that is
913 evaluated when the @code{offload} hook is started. Its return value
914 must be a list of @code{build-machine} objects. While this example
915 shows a fixed list of build machines, one could imagine, say, using
916 DNS-SD to return a list of potential build machines discovered in the
917 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
918 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
921 @deftp {Data Type} build-machine
922 This data type represents build machines to which the daemon may offload
923 builds. The important fields are:
928 The host name of the remote machine.
931 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
934 The user account to use when connecting to the remote machine over SSH.
935 Note that the SSH key pair must @emph{not} be passphrase-protected, to
936 allow non-interactive logins.
939 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
940 This is used to authenticate the machine when we connect to it. It is a
941 long string that looks like this:
944 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
947 If the machine is running the OpenSSH daemon, @command{sshd}, the host
948 key can be found in a file such as
949 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
951 If the machine is running the SSH daemon of GNU@tie{}lsh,
952 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
953 similar file. It can be converted to the OpenSSH format using
954 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
957 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
958 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
963 A number of optional fields may be specified:
967 @item @code{port} (default: @code{22})
968 Port number of SSH server on the machine.
970 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
971 The SSH private key file to use when connecting to the machine, in
974 Note that the default value is the private key @emph{of the root
975 account}. Make sure it exists if you use the default.
977 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
978 @itemx @code{compression-level} (default: @code{3})
979 The SSH-level compression methods and compression level requested.
981 Note that offloading relies on SSH compression to reduce bandwidth usage
982 when transferring files to and from build machines.
984 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
985 File name of the Unix-domain socket @command{guix-daemon} is listening
988 @item @code{parallel-builds} (default: @code{1})
989 The number of builds that may run in parallel on the machine.
991 @item @code{speed} (default: @code{1.0})
992 A ``relative speed factor''. The offload scheduler will tend to prefer
993 machines with a higher speed factor.
995 @item @code{features} (default: @code{'()})
996 A list of strings denoting specific features supported by the machine.
997 An example is @code{"kvm"} for machines that have the KVM Linux modules
998 and corresponding hardware support. Derivations can request features by
999 name, and they will be scheduled on matching build machines.
1004 The @code{guile} command must be in the search path on the build
1005 machines. In addition, the Guix modules must be in
1006 @code{$GUILE_LOAD_PATH} on the build machine---you can check whether
1007 this is the case by running:
1010 ssh build-machine guile -c "'(use-modules (guix config))'"
1013 There is one last thing to do once @file{machines.scm} is in place. As
1014 explained above, when offloading, files are transferred back and forth
1015 between the machine stores. For this to work, you first need to
1016 generate a key pair on each machine to allow the daemon to export signed
1017 archives of files from the store (@pxref{Invoking guix archive}):
1020 # guix archive --generate-key
1024 Each build machine must authorize the key of the master machine so that
1025 it accepts store items it receives from the master:
1028 # guix archive --authorize < master-public-key.txt
1032 Likewise, the master machine must authorize the key of each build machine.
1034 All the fuss with keys is here to express pairwise mutual trust
1035 relations between the master and the build machines. Concretely, when
1036 the master receives files from a build machine (and @i{vice versa}), its
1037 build daemon can make sure they are genuine, have not been tampered
1038 with, and that they are signed by an authorized key.
1040 @cindex offload test
1041 To test whether your setup is operational, run this command on the
1048 This will attempt to connect to each of the build machines specified in
1049 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1050 available on each machine, attempt to export to the machine and import
1051 from it, and report any error in the process.
1053 If you want to test a different machine file, just specify it on the
1057 # guix offload test machines-qualif.scm
1060 Last, you can test the subset of the machines whose name matches a
1061 regular expression like this:
1064 # guix offload test machines.scm '\.gnu\.org$'
1067 @node Invoking guix-daemon
1068 @section Invoking @command{guix-daemon}
1070 The @command{guix-daemon} program implements all the functionality to
1071 access the store. This includes launching build processes, running the
1072 garbage collector, querying the availability of a build result, etc. It
1073 is normally run as @code{root} like this:
1076 # guix-daemon --build-users-group=guixbuild
1080 For details on how to set it up, @pxref{Setting Up the Daemon}.
1083 @cindex container, build environment
1084 @cindex build environment
1085 @cindex reproducible builds
1086 By default, @command{guix-daemon} launches build processes under
1087 different UIDs, taken from the build group specified with
1088 @code{--build-users-group}. In addition, each build process is run in a
1089 chroot environment that only contains the subset of the store that the
1090 build process depends on, as specified by its derivation
1091 (@pxref{Programming Interface, derivation}), plus a set of specific
1092 system directories. By default, the latter contains @file{/dev} and
1093 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1094 @dfn{container}: in addition to having its own file system tree, it has
1095 a separate mount name space, its own PID name space, network name space,
1096 etc. This helps achieve reproducible builds (@pxref{Features}).
1098 When the daemon performs a build on behalf of the user, it creates a
1099 build directory under @file{/tmp} or under the directory specified by
1100 its @code{TMPDIR} environment variable; this directory is shared with
1101 the container for the duration of the build. Be aware that using a
1102 directory other than @file{/tmp} can affect build results---for example,
1103 with a longer directory name, a build process that uses Unix-domain
1104 sockets might hit the name length limitation for @code{sun_path}, which
1105 it would otherwise not hit.
1107 The build directory is automatically deleted upon completion, unless the
1108 build failed and the client specified @option{--keep-failed}
1109 (@pxref{Invoking guix build, @option{--keep-failed}}).
1111 The following command-line options are supported:
1114 @item --build-users-group=@var{group}
1115 Take users from @var{group} to run build processes (@pxref{Setting Up
1116 the Daemon, build users}).
1118 @item --no-substitutes
1120 Do not use substitutes for build products. That is, always build things
1121 locally instead of allowing downloads of pre-built binaries
1122 (@pxref{Substitutes}).
1124 When the daemon runs with @code{--no-substitutes}, clients can still
1125 explicitly enable substitution @i{via} the @code{set-build-options}
1126 remote procedure call (@pxref{The Store}).
1128 @item --substitute-urls=@var{urls}
1129 @anchor{daemon-substitute-urls}
1130 Consider @var{urls} the default whitespace-separated list of substitute
1131 source URLs. When this option is omitted,
1132 @indicateurl{https://mirror.hydra.gnu.org https://hydra.gnu.org} is used
1133 (@code{mirror.hydra.gnu.org} is a mirror of @code{hydra.gnu.org}).
1135 This means that substitutes may be downloaded from @var{urls}, as long
1136 as they are signed by a trusted signature (@pxref{Substitutes}).
1139 @item --no-build-hook
1140 Do not use the @dfn{build hook}.
1142 The build hook is a helper program that the daemon can start and to
1143 which it submits build requests. This mechanism is used to offload
1144 builds to other machines (@pxref{Daemon Offload Setup}).
1146 @item --cache-failures
1147 Cache build failures. By default, only successful builds are cached.
1149 When this option is used, @command{guix gc --list-failures} can be used
1150 to query the set of store items marked as failed; @command{guix gc
1151 --clear-failures} removes store items from the set of cached failures.
1152 @xref{Invoking guix gc}.
1154 @item --cores=@var{n}
1156 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1159 The default value is @code{0}, but it may be overridden by clients, such
1160 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1163 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1164 in the build process, which can then use it to exploit internal
1165 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1167 @item --max-jobs=@var{n}
1169 Allow at most @var{n} build jobs in parallel. The default value is
1170 @code{1}. Setting it to @code{0} means that no builds will be performed
1171 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1172 Setup}), or simply fail.
1174 @item --max-silent-time=@var{seconds}
1175 When the build or substitution process remains silent for more than
1176 @var{seconds}, terminate it and report a build failure.
1178 The default value is @code{0}, which disables the timeout.
1180 The value specified here can be overridden by clients (@pxref{Common
1181 Build Options, @code{--max-silent-time}}).
1183 @item --timeout=@var{seconds}
1184 Likewise, when the build or substitution process lasts for more than
1185 @var{seconds}, terminate it and report a build failure.
1187 The default value is @code{0}, which disables the timeout.
1189 The value specified here can be overridden by clients (@pxref{Common
1190 Build Options, @code{--timeout}}).
1192 @item --rounds=@var{N}
1193 Build each derivation @var{n} times in a row, and raise an error if
1194 consecutive build results are not bit-for-bit identical. Note that this
1195 setting can be overridden by clients such as @command{guix build}
1196 (@pxref{Invoking guix build}).
1198 When used in conjunction with @option{--keep-failed}, the differing
1199 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1200 This makes it easy to look for differences between the two results.
1203 Produce debugging output.
1205 This is useful to debug daemon start-up issues, but then it may be
1206 overridden by clients, for example the @code{--verbosity} option of
1207 @command{guix build} (@pxref{Invoking guix build}).
1209 @item --chroot-directory=@var{dir}
1210 Add @var{dir} to the build chroot.
1212 Doing this may change the result of build processes---for instance if
1213 they use optional dependencies found in @var{dir} when it is available,
1214 and not otherwise. For that reason, it is not recommended to do so.
1215 Instead, make sure that each derivation declares all the inputs that it
1218 @item --disable-chroot
1219 Disable chroot builds.
1221 Using this option is not recommended since, again, it would allow build
1222 processes to gain access to undeclared dependencies. It is necessary,
1223 though, when @command{guix-daemon} is running under an unprivileged user
1226 @item --disable-log-compression
1227 Disable compression of the build logs.
1229 Unless @code{--lose-logs} is used, all the build logs are kept in the
1230 @var{localstatedir}. To save space, the daemon automatically compresses
1231 them with bzip2 by default. This option disables that.
1233 @item --disable-deduplication
1234 @cindex deduplication
1235 Disable automatic file ``deduplication'' in the store.
1237 By default, files added to the store are automatically ``deduplicated'':
1238 if a newly added file is identical to another one found in the store,
1239 the daemon makes the new file a hard link to the other file. This can
1240 noticeably reduce disk usage, at the expense of slightly increased
1241 input/output load at the end of a build process. This option disables
1244 @item --gc-keep-outputs[=yes|no]
1245 Tell whether the garbage collector (GC) must keep outputs of live
1249 @cindex garbage collector roots
1250 When set to ``yes'', the GC will keep the outputs of any live derivation
1251 available in the store---the @code{.drv} files. The default is ``no'',
1252 meaning that derivation outputs are kept only if they are GC roots.
1253 @xref{Invoking guix gc}, for more on GC roots.
1255 @item --gc-keep-derivations[=yes|no]
1256 Tell whether the garbage collector (GC) must keep derivations
1257 corresponding to live outputs.
1259 When set to ``yes'', as is the case by default, the GC keeps
1260 derivations---i.e., @code{.drv} files---as long as at least one of their
1261 outputs is live. This allows users to keep track of the origins of
1262 items in their store. Setting it to ``no'' saves a bit of disk space.
1264 Note that when both @code{--gc-keep-derivations} and
1265 @code{--gc-keep-outputs} are used, the effect is to keep all the build
1266 prerequisites (the sources, compiler, libraries, and other build-time
1267 tools) of live objects in the store, regardless of whether these
1268 prerequisites are live. This is convenient for developers since it
1269 saves rebuilds or downloads.
1271 @item --impersonate-linux-2.6
1272 On Linux-based systems, impersonate Linux 2.6. This means that the
1273 kernel's @code{uname} system call will report 2.6 as the release number.
1275 This might be helpful to build programs that (usually wrongfully) depend
1276 on the kernel version number.
1279 Do not keep build logs. By default they are kept under
1280 @code{@var{localstatedir}/guix/log}.
1282 @item --system=@var{system}
1283 Assume @var{system} as the current system type. By default it is the
1284 architecture/kernel pair found at configure time, such as
1285 @code{x86_64-linux}.
1287 @item --listen=@var{endpoint}
1288 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1289 as the file name of a Unix-domain socket if it starts with
1290 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1291 host name or host name and port to listen to. Here are a few examples:
1294 @item --listen=/gnu/var/daemon
1295 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1296 creating it if needed.
1298 @item --listen=localhost
1299 @cindex daemon, remote access
1300 @cindex remote access to the daemon
1301 @cindex daemon, cluster setup
1302 @cindex clusters, daemon setup
1303 Listen for TCP connections on the network interface corresponding to
1304 @code{localhost}, on port 44146.
1306 @item --listen=128.0.0.42:1234
1307 Listen for TCP connections on the network interface corresponding to
1308 @code{128.0.0.42}, on port 1234.
1311 This option can be repeated multiple times, in which case
1312 @command{guix-daemon} accepts connections on all the specified
1313 endpoints. Users can tell client commands what endpoint to connect to
1314 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1315 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1318 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1319 @code{--listen=@var{host}} is suitable on local networks, such as
1320 clusters, where only trusted nodes may connect to the build daemon. In
1321 other cases where remote access to the daemon is needed, we recommend
1322 using Unix-domain sockets along with SSH.
1325 When @code{--listen} is omitted, @command{guix-daemon} listens for
1326 connections on the Unix-domain socket located at
1327 @file{@var{localstatedir}/daemon-socket/socket}.
1331 @node Application Setup
1332 @section Application Setup
1334 @cindex foreign distro
1335 When using Guix on top of GNU/Linux distribution other than GuixSD---a
1336 so-called @dfn{foreign distro}---a few additional steps are needed to
1337 get everything in place. Here are some of them.
1341 @anchor{locales-and-locpath}
1342 @cindex locales, when not on GuixSD
1344 @vindex GUIX_LOCPATH
1345 Packages installed @i{via} Guix will not use the locale data of the
1346 host system. Instead, you must first install one of the locale packages
1347 available with Guix and then define the @code{GUIX_LOCPATH} environment
1351 $ guix package -i glibc-locales
1352 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1355 Note that the @code{glibc-locales} package contains data for all the
1356 locales supported by the GNU@tie{}libc and weighs in at around
1357 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1358 limited to a few UTF-8 locales.
1360 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1361 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1362 Manual}). There are two important differences though:
1366 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1367 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1368 to make sure the programs of the foreign distro will not end up loading
1369 incompatible locale data.
1372 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1373 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1374 should your Guix profile contain a mixture of programs linked against
1375 different libc version, each libc version will only try to load locale
1376 data in the right format.
1379 This is important because the locale data format used by different libc
1380 versions may be incompatible.
1382 @subsection Name Service Switch
1384 @cindex name service switch, glibc
1385 @cindex NSS (name service switch), glibc
1386 @cindex nscd (name service caching daemon)
1387 @cindex name service caching daemon (nscd)
1388 When using Guix on a foreign distro, we @emph{strongly recommend} that
1389 the system run the GNU C library's @dfn{name service cache daemon},
1390 @command{nscd}, which should be listening on the
1391 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1392 installed with Guix may fail to look up host names or user accounts, or
1393 may even crash. The next paragraphs explain why.
1395 @cindex @file{nsswitch.conf}
1396 The GNU C library implements a @dfn{name service switch} (NSS), which is
1397 an extensible mechanism for ``name lookups'' in general: host name
1398 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1399 The GNU C Library Reference Manual}).
1401 @cindex Network information service (NIS)
1402 @cindex NIS (Network information service)
1403 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1404 lookup implementations: for example, the @code{nss-mdns} plugin allow
1405 resolution of @code{.local} host names, the @code{nis} plugin allows
1406 user account lookup using the Network information service (NIS), and so
1407 on. These extra ``lookup services'' are configured system-wide in
1408 @file{/etc/nsswitch.conf}, and all the programs running on the system
1409 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1412 When they perform a name lookup---for instance by calling the
1413 @code{getaddrinfo} function in C---applications first try to connect to
1414 the nscd; on success, nscd performs name lookups on their behalf. If
1415 the nscd is not running, then they perform the name lookup by
1416 themselves, by loading the name lookup services into their own address
1417 space and running it. These name lookup services---the
1418 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1419 the host system's C library, rather than from the C library the
1420 application is linked against (the C library coming from Guix).
1422 And this is where the problem is: if your application is linked against
1423 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1424 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1425 likely crash or have its name lookups fail unexpectedly.
1427 Running @command{nscd} on the system, among other advantages, eliminates
1428 this binary incompatibility problem because those @code{libnss_*.so}
1429 files are loaded in the @command{nscd} process, not in applications
1432 @subsection X11 Fonts
1435 The majority of graphical applications use Fontconfig to locate and
1436 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1437 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1438 by default. Thus, to allow graphical applications installed with Guix
1439 to display fonts, you have to install fonts with Guix as well.
1440 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1441 @code{font-gnu-freefont-ttf}.
1443 To display text written in Chinese languages, Japanese, or Korean in
1444 graphical applications, consider installing
1445 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1446 has multiple outputs, one per language family (@pxref{Packages with
1447 Multiple Outputs}). For instance, the following command installs fonts
1448 for Chinese languages:
1451 guix package -i font-adobe-source-han-sans:cn
1454 @cindex @code{xterm}
1455 Older programs such as @command{xterm} do not use Fontconfig and instead
1456 rely on server-side font rendering. Such programs require to specify a
1457 full name of a font using XLFD (X Logical Font Description), like this:
1460 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1463 To be able to use such full names for the TrueType fonts installed in
1464 your Guix profile, you need to extend the font path of the X server:
1467 xset +fp ~/.guix-profile/share/fonts/truetype
1470 @cindex @code{xlsfonts}
1471 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1472 to make sure your TrueType fonts are listed there.
1474 @cindex @code{fc-cache}
1476 After installing fonts you may have to refresh the font cache to use
1477 them in applications. The same applies when applications installed via
1478 Guix do not seem to find fonts. To force rebuilding of the font cache
1479 run @code{fc-cache -f}. The @code{fc-cache} command is provided by the
1480 @code{fontconfig} package.
1482 @subsection X.509 Certificates
1484 @cindex @code{nss-certs}
1485 The @code{nss-certs} package provides X.509 certificates, which allow
1486 programs to authenticate Web servers accessed over HTTPS.
1488 When using Guix on a foreign distro, you can install this package and
1489 define the relevant environment variables so that packages know where to
1490 look for certificates. @xref{X.509 Certificates}, for detailed
1493 @subsection Emacs Packages
1495 @cindex @code{emacs}
1496 When you install Emacs packages with Guix, the elisp files may be placed
1497 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1499 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1500 directory exists because potentially there may exist thousands of Emacs
1501 packages and storing all their files in a single directory may be not
1502 reliable (because of name conflicts). So we think using a separate
1503 directory for each package is a good idea. It is very similar to how
1504 the Emacs package system organizes the file structure (@pxref{Package
1505 Files,,, emacs, The GNU Emacs Manual}).
1507 By default, Emacs (installed with Guix) ``knows'' where these packages
1508 are placed, so you do not need to perform any configuration. If, for
1509 some reason, you want to avoid auto-loading Emacs packages installed
1510 with Guix, you can do so by running Emacs with @code{--no-site-file}
1511 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1513 @subsection The GCC toolchain
1518 Guix offers individual compiler packages such as @code{gcc} but if you
1519 are in need of a complete toolchain for compiling and linking source
1520 code what you really want is the @code{gcc-toolchain} package. This
1521 package provides a complete GCC toolchain for C/C++ development,
1522 including GCC itself, the GNU C Library (headers and binaries, plus
1523 debugging symbols in the @code{debug} output), Binutils, and a linker
1526 @cindex attempt to use impure library, error message
1528 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1529 passed to the linker, add corresponding @code{-rpath} arguments, and
1530 invoke the actual linker with this new set of arguments. By default,
1531 the linker wrapper refuses to link to libraries outside the store to
1532 ensure ``purity''. This can be annoying when using the toolchain to
1533 link with local libraries. To allow references to libraries outside the
1534 store you need to define the environment variable
1535 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES}.
1539 @c *********************************************************************
1540 @node Package Management
1541 @chapter Package Management
1544 The purpose of GNU Guix is to allow users to easily install, upgrade, and
1545 remove software packages, without having to know about their build
1546 procedures or dependencies. Guix also goes beyond this obvious set of
1549 This chapter describes the main features of Guix, as well as the
1550 package management tools it provides. Along with the command-line
1551 interface described below (@pxref{Invoking guix package, @code{guix
1552 package}}), you may also use Emacs Interface (@pxref{Top,,,
1553 emacs-guix, The Emacs-Guix Reference Manual}), after installing
1554 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
1558 guix package -i emacs-guix
1562 * Features:: How Guix will make your life brighter.
1563 * Invoking guix package:: Package installation, removal, etc.
1564 * Substitutes:: Downloading pre-built binaries.
1565 * Packages with Multiple Outputs:: Single source package, multiple outputs.
1566 * Invoking guix gc:: Running the garbage collector.
1567 * Invoking guix pull:: Fetching the latest Guix and distribution.
1568 * Invoking guix pack:: Creating software bundles.
1569 * Invoking guix archive:: Exporting and importing store files.
1575 When using Guix, each package ends up in the @dfn{package store}, in its
1576 own directory---something that resembles
1577 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
1579 Instead of referring to these directories, users have their own
1580 @dfn{profile}, which points to the packages that they actually want to
1581 use. These profiles are stored within each user's home directory, at
1582 @code{$HOME/.guix-profile}.
1584 For example, @code{alice} installs GCC 4.7.2. As a result,
1585 @file{/home/alice/.guix-profile/bin/gcc} points to
1586 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
1587 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
1588 simply continues to point to
1589 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
1590 coexist on the same system without any interference.
1592 The @command{guix package} command is the central tool to manage
1593 packages (@pxref{Invoking guix package}). It operates on the per-user
1594 profiles, and can be used @emph{with normal user privileges}.
1596 @cindex transactions
1597 The command provides the obvious install, remove, and upgrade
1598 operations. Each invocation is actually a @emph{transaction}: either
1599 the specified operation succeeds, or nothing happens. Thus, if the
1600 @command{guix package} process is terminated during the transaction,
1601 or if a power outage occurs during the transaction, then the user's
1602 profile remains in its previous state, and remains usable.
1604 In addition, any package transaction may be @emph{rolled back}. So, if,
1605 for example, an upgrade installs a new version of a package that turns
1606 out to have a serious bug, users may roll back to the previous instance
1607 of their profile, which was known to work well. Similarly, the global
1608 system configuration on GuixSD is subject to
1609 transactional upgrades and roll-back
1610 (@pxref{Using the Configuration System}).
1612 All packages in the package store may be @emph{garbage-collected}.
1613 Guix can determine which packages are still referenced by user
1614 profiles, and remove those that are provably no longer referenced
1615 (@pxref{Invoking guix gc}). Users may also explicitly remove old
1616 generations of their profile so that the packages they refer to can be
1619 @cindex reproducibility
1620 @cindex reproducible builds
1621 Finally, Guix takes a @dfn{purely functional} approach to package
1622 management, as described in the introduction (@pxref{Introduction}).
1623 Each @file{/gnu/store} package directory name contains a hash of all the
1624 inputs that were used to build that package---compiler, libraries, build
1625 scripts, etc. This direct correspondence allows users to make sure a
1626 given package installation matches the current state of their
1627 distribution. It also helps maximize @dfn{build reproducibility}:
1628 thanks to the isolated build environments that are used, a given build
1629 is likely to yield bit-identical files when performed on different
1630 machines (@pxref{Invoking guix-daemon, container}).
1633 This foundation allows Guix to support @dfn{transparent binary/source
1634 deployment}. When a pre-built binary for a @file{/gnu/store} item is
1635 available from an external source---a @dfn{substitute}, Guix just
1636 downloads it and unpacks it;
1637 otherwise, it builds the package from source, locally
1638 (@pxref{Substitutes}). Because build results are usually bit-for-bit
1639 reproducible, users do not have to trust servers that provide
1640 substitutes: they can force a local build and @emph{challenge} providers
1641 (@pxref{Invoking guix challenge}).
1643 Control over the build environment is a feature that is also useful for
1644 developers. The @command{guix environment} command allows developers of
1645 a package to quickly set up the right development environment for their
1646 package, without having to manually install the dependencies of the
1647 package into their profile (@pxref{Invoking guix environment}).
1649 @node Invoking guix package
1650 @section Invoking @command{guix package}
1652 @cindex installing packages
1653 @cindex removing packages
1654 @cindex package installation
1655 @cindex package removal
1656 The @command{guix package} command is the tool that allows users to
1657 install, upgrade, and remove packages, as well as rolling back to
1658 previous configurations. It operates only on the user's own profile,
1659 and works with normal user privileges (@pxref{Features}). Its syntax
1663 guix package @var{options}
1665 @cindex transactions
1666 Primarily, @var{options} specifies the operations to be performed during
1667 the transaction. Upon completion, a new profile is created, but
1668 previous @dfn{generations} of the profile remain available, should the user
1671 For example, to remove @code{lua} and install @code{guile} and
1672 @code{guile-cairo} in a single transaction:
1675 guix package -r lua -i guile guile-cairo
1678 @command{guix package} also supports a @dfn{declarative approach}
1679 whereby the user specifies the exact set of packages to be available and
1680 passes it @i{via} the @option{--manifest} option
1681 (@pxref{profile-manifest, @option{--manifest}}).
1684 For each user, a symlink to the user's default profile is automatically
1685 created in @file{$HOME/.guix-profile}. This symlink always points to the
1686 current generation of the user's default profile. Thus, users can add
1687 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
1688 variable, and so on.
1689 @cindex search paths
1690 If you are not using the Guix System Distribution, consider adding the
1691 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
1692 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
1693 shells get all the right environment variable definitions:
1696 GUIX_PROFILE="$HOME/.guix-profile" ; \
1697 source "$HOME/.guix-profile/etc/profile"
1700 In a multi-user setup, user profiles are stored in a place registered as
1701 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
1702 to (@pxref{Invoking guix gc}). That directory is normally
1703 @code{@var{localstatedir}/profiles/per-user/@var{user}}, where
1704 @var{localstatedir} is the value passed to @code{configure} as
1705 @code{--localstatedir}, and @var{user} is the user name. The
1706 @file{per-user} directory is created when @command{guix-daemon} is
1707 started, and the @var{user} sub-directory is created by @command{guix
1710 The @var{options} can be among the following:
1714 @item --install=@var{package} @dots{}
1715 @itemx -i @var{package} @dots{}
1716 Install the specified @var{package}s.
1718 Each @var{package} may specify either a simple package name, such as
1719 @code{guile}, or a package name followed by an at-sign and version number,
1720 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
1721 case, the newest version prefixed by @code{1.8} is selected.)
1723 If no version number is specified, the
1724 newest available version will be selected. In addition, @var{package}
1725 may contain a colon, followed by the name of one of the outputs of the
1726 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
1727 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
1728 name (and optionally version) are searched for among the GNU
1729 distribution modules (@pxref{Package Modules}).
1731 @cindex propagated inputs
1732 Sometimes packages have @dfn{propagated inputs}: these are dependencies
1733 that automatically get installed along with the required package
1734 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
1735 @code{package} objects}, for information about propagated inputs in
1736 package definitions).
1738 @anchor{package-cmd-propagated-inputs}
1739 An example is the GNU MPC library: its C header files refer to those of
1740 the GNU MPFR library, which in turn refer to those of the GMP library.
1741 Thus, when installing MPC, the MPFR and GMP libraries also get installed
1742 in the profile; removing MPC also removes MPFR and GMP---unless they had
1743 also been explicitly installed by the user.
1745 Besides, packages sometimes rely on the definition of environment
1746 variables for their search paths (see explanation of
1747 @code{--search-paths} below). Any missing or possibly incorrect
1748 environment variable definitions are reported here.
1750 @item --install-from-expression=@var{exp}
1752 Install the package @var{exp} evaluates to.
1754 @var{exp} must be a Scheme expression that evaluates to a
1755 @code{<package>} object. This option is notably useful to disambiguate
1756 between same-named variants of a package, with expressions such as
1757 @code{(@@ (gnu packages base) guile-final)}.
1759 Note that this option installs the first output of the specified
1760 package, which may be insufficient when needing a specific output of a
1761 multiple-output package.
1763 @item --install-from-file=@var{file}
1764 @itemx -f @var{file}
1765 Install the package that the code within @var{file} evaluates to.
1767 As an example, @var{file} might contain a definition like this
1768 (@pxref{Defining Packages}):
1771 @verbatiminclude package-hello.scm
1774 Developers may find it useful to include such a @file{guix.scm} file
1775 in the root of their project source tree that can be used to test
1776 development snapshots and create reproducible development environments
1777 (@pxref{Invoking guix environment}).
1779 @item --remove=@var{package} @dots{}
1780 @itemx -r @var{package} @dots{}
1781 Remove the specified @var{package}s.
1783 As for @code{--install}, each @var{package} may specify a version number
1784 and/or output name in addition to the package name. For instance,
1785 @code{-r glibc:debug} would remove the @code{debug} output of
1788 @item --upgrade[=@var{regexp} @dots{}]
1789 @itemx -u [@var{regexp} @dots{}]
1790 @cindex upgrading packages
1791 Upgrade all the installed packages. If one or more @var{regexp}s are
1792 specified, upgrade only installed packages whose name matches a
1793 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
1795 Note that this upgrades package to the latest version of packages found
1796 in the distribution currently installed. To update your distribution,
1797 you should regularly run @command{guix pull} (@pxref{Invoking guix
1800 @item --do-not-upgrade[=@var{regexp} @dots{}]
1801 When used together with the @code{--upgrade} option, do @emph{not}
1802 upgrade any packages whose name matches a @var{regexp}. For example, to
1803 upgrade all packages in the current profile except those containing the
1804 substring ``emacs'':
1807 $ guix package --upgrade . --do-not-upgrade emacs
1810 @item @anchor{profile-manifest}--manifest=@var{file}
1811 @itemx -m @var{file}
1812 @cindex profile declaration
1813 @cindex profile manifest
1814 Create a new generation of the profile from the manifest object
1815 returned by the Scheme code in @var{file}.
1817 This allows you to @emph{declare} the profile's contents rather than
1818 constructing it through a sequence of @code{--install} and similar
1819 commands. The advantage is that @var{file} can be put under version
1820 control, copied to different machines to reproduce the same profile, and
1823 @c FIXME: Add reference to (guix profile) documentation when available.
1824 @var{file} must return a @dfn{manifest} object, which is roughly a list
1827 @findex packages->manifest
1829 (use-package-modules guile emacs)
1834 ;; Use a specific package output.
1835 (list guile-2.0 "debug")))
1838 @findex specifications->manifest
1839 In this example we have to know which modules define the @code{emacs}
1840 and @code{guile-2.0} variables to provide the right
1841 @code{use-package-modules} line, which can be cumbersome. We can
1842 instead provide regular package specifications and let
1843 @code{specifications->manifest} look up the corresponding package
1847 (specifications->manifest
1848 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
1852 @cindex rolling back
1853 @cindex undoing transactions
1854 @cindex transactions, undoing
1855 Roll back to the previous @dfn{generation} of the profile---i.e., undo
1856 the last transaction.
1858 When combined with options such as @code{--install}, roll back occurs
1859 before any other actions.
1861 When rolling back from the first generation that actually contains
1862 installed packages, the profile is made to point to the @dfn{zeroth
1863 generation}, which contains no files apart from its own metadata.
1865 After having rolled back, installing, removing, or upgrading packages
1866 overwrites previous future generations. Thus, the history of the
1867 generations in a profile is always linear.
1869 @item --switch-generation=@var{pattern}
1870 @itemx -S @var{pattern}
1872 Switch to a particular generation defined by @var{pattern}.
1874 @var{pattern} may be either a generation number or a number prefixed
1875 with ``+'' or ``-''. The latter means: move forward/backward by a
1876 specified number of generations. For example, if you want to return to
1877 the latest generation after @code{--roll-back}, use
1878 @code{--switch-generation=+1}.
1880 The difference between @code{--roll-back} and
1881 @code{--switch-generation=-1} is that @code{--switch-generation} will
1882 not make a zeroth generation, so if a specified generation does not
1883 exist, the current generation will not be changed.
1885 @item --search-paths[=@var{kind}]
1886 @cindex search paths
1887 Report environment variable definitions, in Bash syntax, that may be
1888 needed in order to use the set of installed packages. These environment
1889 variables are used to specify @dfn{search paths} for files used by some
1890 of the installed packages.
1892 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
1893 environment variables to be defined so it can look for headers and
1894 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
1895 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
1896 library are installed in the profile, then @code{--search-paths} will
1897 suggest setting these variables to @code{@var{profile}/include} and
1898 @code{@var{profile}/lib}, respectively.
1900 The typical use case is to define these environment variables in the
1904 $ eval `guix package --search-paths`
1907 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
1908 meaning that the returned environment variable definitions will either
1909 be exact settings, or prefixes or suffixes of the current value of these
1910 variables. When omitted, @var{kind} defaults to @code{exact}.
1912 This option can also be used to compute the @emph{combined} search paths
1913 of several profiles. Consider this example:
1916 $ guix package -p foo -i guile
1917 $ guix package -p bar -i guile-json
1918 $ guix package -p foo -p bar --search-paths
1921 The last command above reports about the @code{GUILE_LOAD_PATH}
1922 variable, even though, taken individually, neither @file{foo} nor
1923 @file{bar} would lead to that recommendation.
1926 @item --profile=@var{profile}
1927 @itemx -p @var{profile}
1928 Use @var{profile} instead of the user's default profile.
1931 Produce verbose output. In particular, emit the build log of the
1932 environment on the standard error port.
1935 Use the bootstrap Guile to build the profile. This option is only
1936 useful to distribution developers.
1940 In addition to these actions, @command{guix package} supports the
1941 following options to query the current state of a profile, or the
1942 availability of packages:
1946 @item --search=@var{regexp}
1947 @itemx -s @var{regexp}
1948 @cindex searching for packages
1949 List the available packages whose name, synopsis, or description matches
1950 @var{regexp}, sorted by relevance. Print all the metadata of matching packages in
1951 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
1952 GNU recutils manual}).
1954 This allows specific fields to be extracted using the @command{recsel}
1955 command, for instance:
1958 $ guix package -s malloc | recsel -p name,version,relevance
1972 Similarly, to show the name of all the packages available under the
1973 terms of the GNU@tie{}LGPL version 3:
1976 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
1983 It is also possible to refine search results using several @code{-s}
1984 flags. For example, the following command returns a list of board
1988 $ guix package -s '\<board\>' -s game | recsel -p name
1993 If we were to omit @code{-s game}, we would also get software packages
1994 that deal with printed circuit boards; removing the angle brackets
1995 around @code{board} would further add packages that have to do with
1998 And now for a more elaborate example. The following command searches
1999 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
2000 libraries, and prints the name and synopsis of the matching packages:
2003 $ guix package -s crypto -s library | \
2004 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
2008 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
2009 information on @dfn{selection expressions} for @code{recsel -e}.
2011 @item --show=@var{package}
2012 Show details about @var{package}, taken from the list of available packages, in
2013 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
2017 $ guix package --show=python | recsel -p name,version
2025 You may also specify the full name of a package to only get details about a
2026 specific version of it:
2028 $ guix package --show=python@@3.4 | recsel -p name,version
2035 @item --list-installed[=@var{regexp}]
2036 @itemx -I [@var{regexp}]
2037 List the currently installed packages in the specified profile, with the
2038 most recently installed packages shown last. When @var{regexp} is
2039 specified, list only installed packages whose name matches @var{regexp}.
2041 For each installed package, print the following items, separated by
2042 tabs: the package name, its version string, the part of the package that
2043 is installed (for instance, @code{out} for the default output,
2044 @code{include} for its headers, etc.), and the path of this package in
2047 @item --list-available[=@var{regexp}]
2048 @itemx -A [@var{regexp}]
2049 List packages currently available in the distribution for this system
2050 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
2051 installed packages whose name matches @var{regexp}.
2053 For each package, print the following items separated by tabs: its name,
2054 its version string, the parts of the package (@pxref{Packages with
2055 Multiple Outputs}), and the source location of its definition.
2057 @item --list-generations[=@var{pattern}]
2058 @itemx -l [@var{pattern}]
2060 Return a list of generations along with their creation dates; for each
2061 generation, show the installed packages, with the most recently
2062 installed packages shown last. Note that the zeroth generation is never
2065 For each installed package, print the following items, separated by
2066 tabs: the name of a package, its version string, the part of the package
2067 that is installed (@pxref{Packages with Multiple Outputs}), and the
2068 location of this package in the store.
2070 When @var{pattern} is used, the command returns only matching
2071 generations. Valid patterns include:
2074 @item @emph{Integers and comma-separated integers}. Both patterns denote
2075 generation numbers. For instance, @code{--list-generations=1} returns
2078 And @code{--list-generations=1,8,2} outputs three generations in the
2079 specified order. Neither spaces nor trailing commas are allowed.
2081 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
2082 specified generations and everything in between. Note that the start of
2083 a range must be smaller than its end.
2085 It is also possible to omit the endpoint. For example,
2086 @code{--list-generations=2..}, returns all generations starting from the
2089 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
2090 or months by passing an integer along with the first letter of the
2091 duration. For example, @code{--list-generations=20d} lists generations
2092 that are up to 20 days old.
2095 @item --delete-generations[=@var{pattern}]
2096 @itemx -d [@var{pattern}]
2097 When @var{pattern} is omitted, delete all generations except the current
2100 This command accepts the same patterns as @option{--list-generations}.
2101 When @var{pattern} is specified, delete the matching generations. When
2102 @var{pattern} specifies a duration, generations @emph{older} than the
2103 specified duration match. For instance, @code{--delete-generations=1m}
2104 deletes generations that are more than one month old.
2106 If the current generation matches, it is @emph{not} deleted. Also, the
2107 zeroth generation is never deleted.
2109 Note that deleting generations prevents rolling back to them.
2110 Consequently, this command must be used with care.
2114 Finally, since @command{guix package} may actually start build
2115 processes, it supports all the common build options (@pxref{Common Build
2116 Options}). It also supports package transformation options, such as
2117 @option{--with-source} (@pxref{Package Transformation Options}).
2118 However, note that package transformations are lost when upgrading; to
2119 preserve transformations across upgrades, you should define your own
2120 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
2121 (@pxref{Defining Packages}).
2124 @section Substitutes
2127 @cindex pre-built binaries
2128 Guix supports transparent source/binary deployment, which means that it
2129 can either build things locally, or download pre-built items from a
2130 server, or both. We call these pre-built items @dfn{substitutes}---they
2131 are substitutes for local build results. In many cases, downloading a
2132 substitute is much faster than building things locally.
2134 Substitutes can be anything resulting from a derivation build
2135 (@pxref{Derivations}). Of course, in the common case, they are
2136 pre-built package binaries, but source tarballs, for instance, which
2137 also result from derivation builds, can be available as substitutes.
2140 * Official Substitute Server:: One particular source of substitutes.
2141 * Substitute Server Authorization:: How to enable or disable substitutes.
2142 * Substitute Authentication:: How Guix verifies substitutes.
2143 * Proxy Settings:: How to get substitutes via proxy.
2144 * Substitution Failure:: What happens when substitution fails.
2145 * On Trusting Binaries:: How can you trust that binary blob?
2148 @node Official Substitute Server
2149 @subsection Official Substitute Server
2153 The @code{hydra.gnu.org} server is a front-end to an official build farm
2154 that builds packages from the GNU distribution continuously for some
2155 architectures, and makes them available as substitutes. This is the
2156 default source of substitutes; it can be overridden by passing the
2157 @option{--substitute-urls} option either to @command{guix-daemon}
2158 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
2159 or to client tools such as @command{guix package}
2160 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
2163 Substitute URLs can be either HTTP or HTTPS.
2164 HTTPS is recommended because communications are encrypted; conversely,
2165 using HTTP makes all communications visible to an eavesdropper, who
2166 could use the information gathered to determine, for instance, whether
2167 your system has unpatched security vulnerabilities.
2169 Substitutes from the official build farm are enabled by default when
2170 using the Guix System Distribution (@pxref{GNU Distribution}). However,
2171 they are disabled by default when using Guix on a foreign distribution,
2172 unless you have explicitly enabled them via one of the recommended
2173 installation steps (@pxref{Installation}). The following paragraphs
2174 describe how to enable or disable substitutes for the official build
2175 farm; the same procedure can also be used to enable substitutes for any
2176 other substitute server.
2178 @node Substitute Server Authorization
2179 @subsection Substitute Server Authorization
2182 @cindex substitutes, authorization thereof
2183 @cindex access control list (ACL), for substitutes
2184 @cindex ACL (access control list), for substitutes
2185 To allow Guix to download substitutes from @code{hydra.gnu.org} or a
2187 must add its public key to the access control list (ACL) of archive
2188 imports, using the @command{guix archive} command (@pxref{Invoking guix
2189 archive}). Doing so implies that you trust @code{hydra.gnu.org} to not
2190 be compromised and to serve genuine substitutes.
2192 The public key for @code{hydra.gnu.org} is installed along with Guix, in
2193 @code{@var{prefix}/share/guix/hydra.gnu.org.pub}, where @var{prefix} is
2194 the installation prefix of Guix. If you installed Guix from source,
2195 make sure you checked the GPG signature of
2196 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
2197 Then, you can run something like this:
2200 # guix archive --authorize < hydra.gnu.org.pub
2203 Once this is in place, the output of a command like @code{guix build}
2204 should change from something like:
2207 $ guix build emacs --dry-run
2208 The following derivations would be built:
2209 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
2210 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
2211 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
2212 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
2220 $ guix build emacs --dry-run
2221 The following files would be downloaded:
2222 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
2223 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
2224 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
2225 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
2230 This indicates that substitutes from @code{hydra.gnu.org} are usable and
2231 will be downloaded, when possible, for future builds.
2233 @cindex substitutes, how to disable
2234 The substitute mechanism can be disabled globally by running
2235 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
2236 guix-daemon}). It can also be disabled temporarily by passing the
2237 @code{--no-substitutes} option to @command{guix package}, @command{guix
2238 build}, and other command-line tools.
2240 @node Substitute Authentication
2241 @subsection Substitute Authentication
2243 @cindex digital signatures
2244 Guix detects and raises an error when attempting to use a substitute
2245 that has been tampered with. Likewise, it ignores substitutes that are
2246 not signed, or that are not signed by one of the keys listed in the ACL.
2248 There is one exception though: if an unauthorized server provides
2249 substitutes that are @emph{bit-for-bit identical} to those provided by
2250 an authorized server, then the unauthorized server becomes eligible for
2251 downloads. For example, assume we have chosen two substitute servers
2255 --substitute-urls="https://a.example.org https://b.example.org"
2259 @cindex reproducible builds
2260 If the ACL contains only the key for @code{b.example.org}, and if
2261 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
2262 then Guix will download substitutes from @code{a.example.org} because it
2263 comes first in the list and can be considered a mirror of
2264 @code{b.example.org}. In practice, independent build machines usually
2265 produce the same binaries, thanks to bit-reproducible builds (see
2268 When using HTTPS, the server's X.509 certificate is @emph{not} validated
2269 (in other words, the server is not authenticated), contrary to what
2270 HTTPS clients such as Web browsers usually do. This is because Guix
2271 authenticates substitute information itself, as explained above, which
2272 is what we care about (whereas X.509 certificates are about
2273 authenticating bindings between domain names and public keys.)
2275 @node Proxy Settings
2276 @subsection Proxy Settings
2279 Substitutes are downloaded over HTTP or HTTPS.
2280 The @code{http_proxy} environment
2281 variable can be set in the environment of @command{guix-daemon} and is
2282 honored for downloads of substitutes. Note that the value of
2283 @code{http_proxy} in the environment where @command{guix build},
2284 @command{guix package}, and other client commands are run has
2285 @emph{absolutely no effect}.
2287 @node Substitution Failure
2288 @subsection Substitution Failure
2290 Even when a substitute for a derivation is available, sometimes the
2291 substitution attempt will fail. This can happen for a variety of
2292 reasons: the substitute server might be offline, the substitute may
2293 recently have been deleted, the connection might have been interrupted,
2296 When substitutes are enabled and a substitute for a derivation is
2297 available, but the substitution attempt fails, Guix will attempt to
2298 build the derivation locally depending on whether or not
2299 @code{--fallback} was given (@pxref{fallback-option,, common build
2300 option @code{--fallback}}). Specifically, if @code{--fallback} was
2301 omitted, then no local build will be performed, and the derivation is
2302 considered to have failed. However, if @code{--fallback} was given,
2303 then Guix will attempt to build the derivation locally, and the success
2304 or failure of the derivation depends on the success or failure of the
2305 local build. Note that when substitutes are disabled or no substitute
2306 is available for the derivation in question, a local build will
2307 @emph{always} be performed, regardless of whether or not
2308 @code{--fallback} was given.
2310 To get an idea of how many substitutes are available right now, you can
2311 try running the @command{guix weather} command (@pxref{Invoking guix
2312 weather}). This command provides statistics on the substitutes provided
2315 @node On Trusting Binaries
2316 @subsection On Trusting Binaries
2318 @cindex trust, of pre-built binaries
2319 Today, each individual's control over their own computing is at the
2320 mercy of institutions, corporations, and groups with enough power and
2321 determination to subvert the computing infrastructure and exploit its
2322 weaknesses. While using @code{hydra.gnu.org} substitutes can be
2323 convenient, we encourage users to also build on their own, or even run
2324 their own build farm, such that @code{hydra.gnu.org} is less of an
2325 interesting target. One way to help is by publishing the software you
2326 build using @command{guix publish} so that others have one more choice
2327 of server to download substitutes from (@pxref{Invoking guix publish}).
2329 Guix has the foundations to maximize build reproducibility
2330 (@pxref{Features}). In most cases, independent builds of a given
2331 package or derivation should yield bit-identical results. Thus, through
2332 a diverse set of independent package builds, we can strengthen the
2333 integrity of our systems. The @command{guix challenge} command aims to
2334 help users assess substitute servers, and to assist developers in
2335 finding out about non-deterministic package builds (@pxref{Invoking guix
2336 challenge}). Similarly, the @option{--check} option of @command{guix
2337 build} allows users to check whether previously-installed substitutes
2338 are genuine by rebuilding them locally (@pxref{build-check,
2339 @command{guix build --check}}).
2341 In the future, we want Guix to have support to publish and retrieve
2342 binaries to/from other users, in a peer-to-peer fashion. If you would
2343 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
2345 @node Packages with Multiple Outputs
2346 @section Packages with Multiple Outputs
2348 @cindex multiple-output packages
2349 @cindex package outputs
2352 Often, packages defined in Guix have a single @dfn{output}---i.e., the
2353 source package leads to exactly one directory in the store. When running
2354 @command{guix package -i glibc}, one installs the default output of the
2355 GNU libc package; the default output is called @code{out}, but its name
2356 can be omitted as shown in this command. In this particular case, the
2357 default output of @code{glibc} contains all the C header files, shared
2358 libraries, static libraries, Info documentation, and other supporting
2361 Sometimes it is more appropriate to separate the various types of files
2362 produced from a single source package into separate outputs. For
2363 instance, the GLib C library (used by GTK+ and related packages)
2364 installs more than 20 MiB of reference documentation as HTML pages.
2365 To save space for users who do not need it, the documentation goes to a
2366 separate output, called @code{doc}. To install the main GLib output,
2367 which contains everything but the documentation, one would run:
2370 guix package -i glib
2373 @cindex documentation
2374 The command to install its documentation is:
2377 guix package -i glib:doc
2380 Some packages install programs with different ``dependency footprints''.
2381 For instance, the WordNet package installs both command-line tools and
2382 graphical user interfaces (GUIs). The former depend solely on the C
2383 library, whereas the latter depend on Tcl/Tk and the underlying X
2384 libraries. In this case, we leave the command-line tools in the default
2385 output, whereas the GUIs are in a separate output. This allows users
2386 who do not need the GUIs to save space. The @command{guix size} command
2387 can help find out about such situations (@pxref{Invoking guix size}).
2388 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
2390 There are several such multiple-output packages in the GNU distribution.
2391 Other conventional output names include @code{lib} for libraries and
2392 possibly header files, @code{bin} for stand-alone programs, and
2393 @code{debug} for debugging information (@pxref{Installing Debugging
2394 Files}). The outputs of a packages are listed in the third column of
2395 the output of @command{guix package --list-available} (@pxref{Invoking
2399 @node Invoking guix gc
2400 @section Invoking @command{guix gc}
2402 @cindex garbage collector
2404 Packages that are installed, but not used, may be @dfn{garbage-collected}.
2405 The @command{guix gc} command allows users to explicitly run the garbage
2406 collector to reclaim space from the @file{/gnu/store} directory. It is
2407 the @emph{only} way to remove files from @file{/gnu/store}---removing
2408 files or directories manually may break it beyond repair!
2411 @cindex garbage collector roots
2412 The garbage collector has a set of known @dfn{roots}: any file under
2413 @file{/gnu/store} reachable from a root is considered @dfn{live} and
2414 cannot be deleted; any other file is considered @dfn{dead} and may be
2415 deleted. The set of garbage collector roots (``GC roots'' for short)
2416 includes default user profiles; by default, the symlinks under
2417 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
2418 added with @command{guix build --root}, for example (@pxref{Invoking
2421 Prior to running @code{guix gc --collect-garbage} to make space, it is
2422 often useful to remove old generations from user profiles; that way, old
2423 package builds referenced by those generations can be reclaimed. This
2424 is achieved by running @code{guix package --delete-generations}
2425 (@pxref{Invoking guix package}).
2427 Our recommendation is to run a garbage collection periodically, or when
2428 you are short on disk space. For instance, to guarantee that at least
2429 5@tie{}GB are available on your disk, simply run:
2435 It is perfectly safe to run as a non-interactive periodic job
2436 (@pxref{Scheduled Job Execution}, for how to set up such a job on
2437 GuixSD). Running @command{guix gc} with no arguments will collect as
2438 much garbage as it can, but that is often inconvenient: you may find
2439 yourself having to rebuild or re-download software that is ``dead'' from
2440 the GC viewpoint but that is necessary to build other pieces of
2441 software---e.g., the compiler tool chain.
2443 The @command{guix gc} command has three modes of operation: it can be
2444 used to garbage-collect any dead files (the default), to delete specific
2445 files (the @code{--delete} option), to print garbage-collector
2446 information, or for more advanced queries. The garbage collection
2447 options are as follows:
2450 @item --collect-garbage[=@var{min}]
2451 @itemx -C [@var{min}]
2452 Collect garbage---i.e., unreachable @file{/gnu/store} files and
2453 sub-directories. This is the default operation when no option is
2456 When @var{min} is given, stop once @var{min} bytes have been collected.
2457 @var{min} may be a number of bytes, or it may include a unit as a
2458 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
2459 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
2461 When @var{min} is omitted, collect all the garbage.
2463 @item --free-space=@var{free}
2464 @itemx -F @var{free}
2465 Collect garbage until @var{free} space is available under
2466 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
2467 as @code{500MiB}, as described above.
2469 When @var{free} or more is already available in @file{/gnu/store}, do
2470 nothing and exit immediately.
2474 Attempt to delete all the store files and directories specified as
2475 arguments. This fails if some of the files are not in the store, or if
2476 they are still live.
2478 @item --list-failures
2479 List store items corresponding to cached build failures.
2481 This prints nothing unless the daemon was started with
2482 @option{--cache-failures} (@pxref{Invoking guix-daemon,
2483 @option{--cache-failures}}).
2485 @item --clear-failures
2486 Remove the specified store items from the failed-build cache.
2488 Again, this option only makes sense when the daemon is started with
2489 @option{--cache-failures}. Otherwise, it does nothing.
2492 Show the list of dead files and directories still present in the
2493 store---i.e., files and directories no longer reachable from any root.
2496 Show the list of live store files and directories.
2500 In addition, the references among existing store files can be queried:
2506 @cindex package dependencies
2507 List the references (respectively, the referrers) of store files given
2513 List the requisites of the store files passed as arguments. Requisites
2514 include the store files themselves, their references, and the references
2515 of these, recursively. In other words, the returned list is the
2516 @dfn{transitive closure} of the store files.
2518 @xref{Invoking guix size}, for a tool to profile the size of the closure
2519 of an element. @xref{Invoking guix graph}, for a tool to visualize
2520 the graph of references.
2524 Lastly, the following options allow you to check the integrity of the
2525 store and to control disk usage.
2529 @item --verify[=@var{options}]
2530 @cindex integrity, of the store
2531 @cindex integrity checking
2532 Verify the integrity of the store.
2534 By default, make sure that all the store items marked as valid in the
2535 database of the daemon actually exist in @file{/gnu/store}.
2537 When provided, @var{options} must be a comma-separated list containing one
2538 or more of @code{contents} and @code{repair}.
2540 When passing @option{--verify=contents}, the daemon computes the
2541 content hash of each store item and compares it against its hash in the
2542 database. Hash mismatches are reported as data corruptions. Because it
2543 traverses @emph{all the files in the store}, this command can take a
2544 long time, especially on systems with a slow disk drive.
2546 @cindex repairing the store
2547 @cindex corruption, recovering from
2548 Using @option{--verify=repair} or @option{--verify=contents,repair}
2549 causes the daemon to try to repair corrupt store items by fetching
2550 substitutes for them (@pxref{Substitutes}). Because repairing is not
2551 atomic, and thus potentially dangerous, it is available only to the
2552 system administrator. A lightweight alternative, when you know exactly
2553 which items in the store are corrupt, is @command{guix build --repair}
2554 (@pxref{Invoking guix build}).
2557 @cindex deduplication
2558 Optimize the store by hard-linking identical files---this is
2559 @dfn{deduplication}.
2561 The daemon performs deduplication after each successful build or archive
2562 import, unless it was started with @code{--disable-deduplication}
2563 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
2564 this option is primarily useful when the daemon was running with
2565 @code{--disable-deduplication}.
2569 @node Invoking guix pull
2570 @section Invoking @command{guix pull}
2572 @cindex upgrading Guix
2573 @cindex updating Guix
2574 @cindex @command{guix pull}
2576 Packages are installed or upgraded to the latest version available in
2577 the distribution currently available on your local machine. To update
2578 that distribution, along with the Guix tools, you must run @command{guix
2579 pull}: the command downloads the latest Guix source code and package
2580 descriptions, and deploys it. Source code is downloaded from a
2581 @uref{https://git-scm.com, Git} repository.
2583 On completion, @command{guix package} will use packages and package
2584 versions from this just-retrieved copy of Guix. Not only that, but all
2585 the Guix commands and Scheme modules will also be taken from that latest
2586 version. New @command{guix} sub-commands added by the update also
2589 Any user can update their Guix copy using @command{guix pull}, and the
2590 effect is limited to the user who run @command{guix pull}. For
2591 instance, when user @code{root} runs @command{guix pull}, this has no
2592 effect on the version of Guix that user @code{alice} sees, and vice
2593 versa@footnote{Under the hood, @command{guix pull} updates the
2594 @file{~/.config/guix/latest} symbolic link to point to the latest Guix,
2595 and the @command{guix} command loads code from there. Currently, the
2596 only way to roll back an invocation of @command{guix pull} is to
2597 manually update this symlink to point to the previous Guix.}.
2599 The @command{guix pull} command is usually invoked with no arguments,
2600 but it supports the following options:
2604 Produce verbose output, writing build logs to the standard error output.
2606 @item --url=@var{url}
2607 Download Guix from the Git repository at @var{url}.
2609 @vindex GUIX_PULL_URL
2610 By default, the source is taken from its canonical Git repository at
2611 @code{gnu.org}, for the stable branch of Guix. To use a different source,
2612 set the @code{GUIX_PULL_URL} environment variable.
2614 @item --commit=@var{commit}
2615 Deploy @var{commit}, a valid Git commit ID represented as a hexadecimal
2618 @item --branch=@var{branch}
2619 Deploy the tip of @var{branch}, the name of a Git branch available on
2620 the repository at @var{url}.
2623 Use the bootstrap Guile to build the latest Guix. This option is only
2624 useful to Guix developers.
2627 In addition, @command{guix pull} supports all the common build options
2628 (@pxref{Common Build Options}).
2630 @node Invoking guix pack
2631 @section Invoking @command{guix pack}
2633 Occasionally you want to pass software to people who are not (yet!)
2634 lucky enough to be using Guix. You'd tell them to run @command{guix
2635 package -i @var{something}}, but that's not possible in this case. This
2636 is where @command{guix pack} comes in.
2640 @cindex application bundle
2641 @cindex software bundle
2642 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
2643 @dfn{software bundle}: it creates a tarball or some other archive
2644 containing the binaries of the software you're interested in, and all
2645 its dependencies. The resulting archive can be used on any machine that
2646 does not have Guix, and people can run the exact same binaries as those
2647 you have with Guix. The pack itself is created in a bit-reproducible
2648 fashion, so anyone can verify that it really contains the build results
2649 that you pretend to be shipping.
2651 For example, to create a bundle containing Guile, Emacs, Geiser, and all
2652 their dependencies, you can run:
2655 $ guix pack guile emacs geiser
2657 /gnu/store/@dots{}-pack.tar.gz
2660 The result here is a tarball containing a @file{/gnu/store} directory
2661 with all the relevant packages. The resulting tarball contains a
2662 @dfn{profile} with the three packages of interest; the profile is the
2663 same as would be created by @command{guix package -i}. It is this
2664 mechanism that is used to create Guix's own standalone binary tarball
2665 (@pxref{Binary Installation}).
2667 Users of this pack would have to run
2668 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
2669 find inconvenient. To work around it, you can create, say, a
2670 @file{/opt/gnu/bin} symlink to the profile:
2673 guix pack -S /opt/gnu/bin=bin guile emacs geiser
2677 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
2679 Alternatively, you can produce a pack in the Docker image format using
2680 the following command:
2683 guix pack -f docker guile emacs geiser
2687 The result is a tarball that can be passed to the @command{docker load}
2689 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
2690 documentation} for more information.
2692 Several command-line options allow you to customize your pack:
2695 @item --format=@var{format}
2696 @itemx -f @var{format}
2697 Produce a pack in the given @var{format}.
2699 The available formats are:
2703 This is the default format. It produces a tarball containing all the
2704 specified binaries and symlinks.
2707 This produces a tarball that follows the
2708 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
2709 Docker Image Specification}.
2712 @item --expression=@var{expr}
2713 @itemx -e @var{expr}
2714 Consider the package @var{expr} evaluates to.
2716 This has the same purpose as the same-named option in @command{guix
2717 build} (@pxref{Additional Build Options, @code{--expression} in
2718 @command{guix build}}).
2720 @item --system=@var{system}
2721 @itemx -s @var{system}
2722 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
2723 the system type of the build host.
2725 @item --target=@var{triplet}
2726 @cindex cross-compilation
2727 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
2728 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
2729 configuration triplets,, autoconf, Autoconf}).
2731 @item --compression=@var{tool}
2732 @itemx -C @var{tool}
2733 Compress the resulting tarball using @var{tool}---one of @code{gzip},
2734 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
2736 @item --symlink=@var{spec}
2737 @itemx -S @var{spec}
2738 Add the symlinks specified by @var{spec} to the pack. This option can
2739 appear several times.
2741 @var{spec} has the form @code{@var{source}=@var{target}}, where
2742 @var{source} is the symlink that will be created and @var{target} is the
2745 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
2746 symlink pointing to the @file{bin} sub-directory of the profile.
2748 @item --localstatedir
2749 Include the ``local state directory'', @file{/var/guix}, in the
2752 @file{/var/guix} contains the store database (@pxref{The Store}) as well
2753 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
2754 the pack means that the store is ``complete'' and manageable by Guix;
2755 not providing it pack means that the store is ``dead'': items cannot be
2756 added to it or removed from it after extraction of the pack.
2758 One use case for this is the Guix self-contained binary tarball
2759 (@pxref{Binary Installation}).
2762 In addition, @command{guix pack} supports all the common build options
2763 (@pxref{Common Build Options}) and all the package transformation
2764 options (@pxref{Package Transformation Options}).
2767 @node Invoking guix archive
2768 @section Invoking @command{guix archive}
2770 @cindex @command{guix archive}
2772 The @command{guix archive} command allows users to @dfn{export} files
2773 from the store into a single archive, and to later @dfn{import} them.
2774 In particular, it allows store files to be transferred from one machine
2775 to the store on another machine.
2777 @cindex exporting store items
2778 To export store files as an archive to standard output, run:
2781 guix archive --export @var{options} @var{specifications}...
2784 @var{specifications} may be either store file names or package
2785 specifications, as for @command{guix package} (@pxref{Invoking guix
2786 package}). For instance, the following command creates an archive
2787 containing the @code{gui} output of the @code{git} package and the main
2788 output of @code{emacs}:
2791 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
2794 If the specified packages are not built yet, @command{guix archive}
2795 automatically builds them. The build process may be controlled with the
2796 common build options (@pxref{Common Build Options}).
2798 To transfer the @code{emacs} package to a machine connected over SSH,
2802 guix archive --export -r emacs | ssh the-machine guix archive --import
2806 Similarly, a complete user profile may be transferred from one machine
2807 to another like this:
2810 guix archive --export -r $(readlink -f ~/.guix-profile) | \
2811 ssh the-machine guix-archive --import
2815 However, note that, in both examples, all of @code{emacs} and the
2816 profile as well as all of their dependencies are transferred (due to
2817 @code{-r}), regardless of what is already available in the store on the
2818 target machine. The @code{--missing} option can help figure out which
2819 items are missing from the target store. The @command{guix copy}
2820 command simplifies and optimizes this whole process, so this is probably
2821 what you should use in this case (@pxref{Invoking guix copy}).
2823 @cindex nar, archive format
2824 @cindex normalized archive (nar)
2825 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
2826 comparable in spirit to `tar', but with differences
2827 that make it more appropriate for our purposes. First, rather than
2828 recording all Unix metadata for each file, the nar format only mentions
2829 the file type (regular, directory, or symbolic link); Unix permissions
2830 and owner/group are dismissed. Second, the order in which directory
2831 entries are stored always follows the order of file names according to
2832 the C locale collation order. This makes archive production fully
2835 When exporting, the daemon digitally signs the contents of the archive,
2836 and that digital signature is appended. When importing, the daemon
2837 verifies the signature and rejects the import in case of an invalid
2838 signature or if the signing key is not authorized.
2839 @c FIXME: Add xref to daemon doc about signatures.
2841 The main options are:
2845 Export the specified store files or packages (see below.) Write the
2846 resulting archive to the standard output.
2848 Dependencies are @emph{not} included in the output, unless
2849 @code{--recursive} is passed.
2853 When combined with @code{--export}, this instructs @command{guix
2854 archive} to include dependencies of the given items in the archive.
2855 Thus, the resulting archive is self-contained: it contains the closure
2856 of the exported store items.
2859 Read an archive from the standard input, and import the files listed
2860 therein into the store. Abort if the archive has an invalid digital
2861 signature, or if it is signed by a public key not among the authorized
2862 keys (see @code{--authorize} below.)
2865 Read a list of store file names from the standard input, one per line,
2866 and write on the standard output the subset of these files missing from
2869 @item --generate-key[=@var{parameters}]
2870 @cindex signing, archives
2871 Generate a new key pair for the daemon. This is a prerequisite before
2872 archives can be exported with @code{--export}. Note that this operation
2873 usually takes time, because it needs to gather enough entropy to
2874 generate the key pair.
2876 The generated key pair is typically stored under @file{/etc/guix}, in
2877 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
2878 key, which must be kept secret.) When @var{parameters} is omitted,
2879 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
2880 versions before 1.6.0, it is a 4096-bit RSA key.
2881 Alternatively, @var{parameters} can specify
2882 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
2883 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
2884 Libgcrypt Reference Manual}).
2887 @cindex authorizing, archives
2888 Authorize imports signed by the public key passed on standard input.
2889 The public key must be in ``s-expression advanced format''---i.e., the
2890 same format as the @file{signing-key.pub} file.
2892 The list of authorized keys is kept in the human-editable file
2893 @file{/etc/guix/acl}. The file contains
2894 @url{http://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
2895 s-expressions''} and is structured as an access-control list in the
2896 @url{http://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
2899 @item --extract=@var{directory}
2900 @itemx -x @var{directory}
2901 Read a single-item archive as served by substitute servers
2902 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
2903 low-level operation needed in only very narrow use cases; see below.
2905 For example, the following command extracts the substitute for Emacs
2906 served by @code{hydra.gnu.org} to @file{/tmp/emacs}:
2910 https://hydra.gnu.org/nar/@dots{}-emacs-24.5 \
2911 | bunzip2 | guix archive -x /tmp/emacs
2914 Single-item archives are different from multiple-item archives produced
2915 by @command{guix archive --export}; they contain a single store item,
2916 and they do @emph{not} embed a signature. Thus this operation does
2917 @emph{no} signature verification and its output should be considered
2920 The primary purpose of this operation is to facilitate inspection of
2921 archive contents coming from possibly untrusted substitute servers.
2925 @c *********************************************************************
2926 @node Programming Interface
2927 @chapter Programming Interface
2929 GNU Guix provides several Scheme programming interfaces (APIs) to
2930 define, build, and query packages. The first interface allows users to
2931 write high-level package definitions. These definitions refer to
2932 familiar packaging concepts, such as the name and version of a package,
2933 its build system, and its dependencies. These definitions can then be
2934 turned into concrete build actions.
2936 Build actions are performed by the Guix daemon, on behalf of users. In a
2937 standard setup, the daemon has write access to the store---the
2938 @file{/gnu/store} directory---whereas users do not. The recommended
2939 setup also has the daemon perform builds in chroots, under a specific
2940 build users, to minimize interference with the rest of the system.
2943 Lower-level APIs are available to interact with the daemon and the
2944 store. To instruct the daemon to perform a build action, users actually
2945 provide it with a @dfn{derivation}. A derivation is a low-level
2946 representation of the build actions to be taken, and the environment in
2947 which they should occur---derivations are to package definitions what
2948 assembly is to C programs. The term ``derivation'' comes from the fact
2949 that build results @emph{derive} from them.
2951 This chapter describes all these APIs in turn, starting from high-level
2952 package definitions.
2955 * Defining Packages:: Defining new packages.
2956 * Build Systems:: Specifying how packages are built.
2957 * The Store:: Manipulating the package store.
2958 * Derivations:: Low-level interface to package derivations.
2959 * The Store Monad:: Purely functional interface to the store.
2960 * G-Expressions:: Manipulating build expressions.
2963 @node Defining Packages
2964 @section Defining Packages
2966 The high-level interface to package definitions is implemented in the
2967 @code{(guix packages)} and @code{(guix build-system)} modules. As an
2968 example, the package definition, or @dfn{recipe}, for the GNU Hello
2969 package looks like this:
2972 (define-module (gnu packages hello)
2973 #:use-module (guix packages)
2974 #:use-module (guix download)
2975 #:use-module (guix build-system gnu)
2976 #:use-module (guix licenses)
2977 #:use-module (gnu packages gawk))
2979 (define-public hello
2985 (uri (string-append "mirror://gnu/hello/hello-" version
2989 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
2990 (build-system gnu-build-system)
2991 (arguments '(#:configure-flags '("--enable-silent-rules")))
2992 (inputs `(("gawk" ,gawk)))
2993 (synopsis "Hello, GNU world: An example GNU package")
2994 (description "Guess what GNU Hello prints!")
2995 (home-page "http://www.gnu.org/software/hello/")
3000 Without being a Scheme expert, the reader may have guessed the meaning
3001 of the various fields here. This expression binds the variable
3002 @code{hello} to a @code{<package>} object, which is essentially a record
3003 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
3004 This package object can be inspected using procedures found in the
3005 @code{(guix packages)} module; for instance, @code{(package-name hello)}
3006 returns---surprise!---@code{"hello"}.
3008 With luck, you may be able to import part or all of the definition of
3009 the package you are interested in from another repository, using the
3010 @code{guix import} command (@pxref{Invoking guix import}).
3012 In the example above, @var{hello} is defined in a module of its own,
3013 @code{(gnu packages hello)}. Technically, this is not strictly
3014 necessary, but it is convenient to do so: all the packages defined in
3015 modules under @code{(gnu packages @dots{})} are automatically known to
3016 the command-line tools (@pxref{Package Modules}).
3018 There are a few points worth noting in the above package definition:
3022 The @code{source} field of the package is an @code{<origin>} object
3023 (@pxref{origin Reference}, for the complete reference).
3024 Here, the @code{url-fetch} method from @code{(guix download)} is used,
3025 meaning that the source is a file to be downloaded over FTP or HTTP.
3027 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
3028 the GNU mirrors defined in @code{(guix download)}.
3030 The @code{sha256} field specifies the expected SHA256 hash of the file
3031 being downloaded. It is mandatory, and allows Guix to check the
3032 integrity of the file. The @code{(base32 @dots{})} form introduces the
3033 base32 representation of the hash. You can obtain this information with
3034 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
3035 hash} (@pxref{Invoking guix hash}).
3038 When needed, the @code{origin} form can also have a @code{patches} field
3039 listing patches to be applied, and a @code{snippet} field giving a
3040 Scheme expression to modify the source code.
3043 @cindex GNU Build System
3044 The @code{build-system} field specifies the procedure to build the
3045 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
3046 represents the familiar GNU Build System, where packages may be
3047 configured, built, and installed with the usual @code{./configure &&
3048 make && make check && make install} command sequence.
3051 The @code{arguments} field specifies options for the build system
3052 (@pxref{Build Systems}). Here it is interpreted by
3053 @var{gnu-build-system} as a request run @file{configure} with the
3054 @code{--enable-silent-rules} flag.
3060 What about these quote (@code{'}) characters? They are Scheme syntax to
3061 introduce a literal list; @code{'} is synonymous with @code{quote}.
3062 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
3063 for details. Here the value of the @code{arguments} field is a list of
3064 arguments passed to the build system down the road, as with @code{apply}
3065 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
3068 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
3069 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
3070 @code{#:configure-flags} is a keyword used to pass a keyword argument
3071 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
3075 The @code{inputs} field specifies inputs to the build process---i.e.,
3076 build-time or run-time dependencies of the package. Here, we define an
3077 input called @code{"gawk"} whose value is that of the @var{gawk}
3078 variable; @var{gawk} is itself bound to a @code{<package>} object.
3080 @cindex backquote (quasiquote)
3083 @cindex comma (unquote)
3087 @findex unquote-splicing
3088 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
3089 us to introduce a literal list in the @code{inputs} field, while
3090 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
3091 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
3094 Note that GCC, Coreutils, Bash, and other essential tools do not need to
3095 be specified as inputs here. Instead, @var{gnu-build-system} takes care
3096 of ensuring that they are present (@pxref{Build Systems}).
3098 However, any other dependencies need to be specified in the
3099 @code{inputs} field. Any dependency not specified here will simply be
3100 unavailable to the build process, possibly leading to a build failure.
3103 @xref{package Reference}, for a full description of possible fields.
3105 Once a package definition is in place, the
3106 package may actually be built using the @code{guix build} command-line
3107 tool (@pxref{Invoking guix build}), troubleshooting any build failures
3108 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
3109 package definition using the @command{guix edit} command
3110 (@pxref{Invoking guix edit}).
3111 @xref{Packaging Guidelines}, for
3112 more information on how to test package definitions, and
3113 @ref{Invoking guix lint}, for information on how to check a definition
3114 for style conformance.
3115 @vindex GUIX_PACKAGE_PATH
3116 Lastly, @pxref{Package Modules}, for information
3117 on how to extend the distribution by adding your own package definitions
3118 to @code{GUIX_PACKAGE_PATH}.
3120 Finally, updating the package definition to a new upstream version
3121 can be partly automated by the @command{guix refresh} command
3122 (@pxref{Invoking guix refresh}).
3124 Behind the scenes, a derivation corresponding to the @code{<package>}
3125 object is first computed by the @code{package-derivation} procedure.
3126 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
3127 The build actions it prescribes may then be realized by using the
3128 @code{build-derivations} procedure (@pxref{The Store}).
3130 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
3131 Return the @code{<derivation>} object of @var{package} for @var{system}
3132 (@pxref{Derivations}).
3134 @var{package} must be a valid @code{<package>} object, and @var{system}
3135 must be a string denoting the target system type---e.g.,
3136 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
3137 must be a connection to the daemon, which operates on the store
3138 (@pxref{The Store}).
3142 @cindex cross-compilation
3143 Similarly, it is possible to compute a derivation that cross-builds a
3144 package for some other system:
3146 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
3147 @var{package} @var{target} [@var{system}]
3148 Return the @code{<derivation>} object of @var{package} cross-built from
3149 @var{system} to @var{target}.
3151 @var{target} must be a valid GNU triplet denoting the target hardware
3152 and operating system, such as @code{"mips64el-linux-gnu"}
3153 (@pxref{Configuration Names, GNU configuration triplets,, configure, GNU
3154 Configure and Build System}).
3157 @cindex package transformations
3158 @cindex input rewriting
3159 @cindex dependency tree rewriting
3160 Packages can be manipulated in arbitrary ways. An example of a useful
3161 transformation is @dfn{input rewriting}, whereby the dependency tree of
3162 a package is rewritten by replacing specific inputs by others:
3164 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
3165 [@var{rewrite-name}]
3166 Return a procedure that, when passed a package, replaces its direct and
3167 indirect dependencies (but not its implicit inputs) according to
3168 @var{replacements}. @var{replacements} is a list of package pairs; the
3169 first element of each pair is the package to replace, and the second one
3172 Optionally, @var{rewrite-name} is a one-argument procedure that takes
3173 the name of a package and returns its new name after rewrite.
3177 Consider this example:
3180 (define libressl-instead-of-openssl
3181 ;; This is a procedure to replace OPENSSL by LIBRESSL,
3183 (package-input-rewriting `((,openssl . ,libressl))))
3185 (define git-with-libressl
3186 (libressl-instead-of-openssl git))
3190 Here we first define a rewriting procedure that replaces @var{openssl}
3191 with @var{libressl}. Then we use it to define a @dfn{variant} of the
3192 @var{git} package that uses @var{libressl} instead of @var{openssl}.
3193 This is exactly what the @option{--with-input} command-line option does
3194 (@pxref{Package Transformation Options, @option{--with-input}}).
3196 A more generic procedure to rewrite a package dependency graph is
3197 @code{package-mapping}: it supports arbitrary changes to nodes in the
3200 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
3201 Return a procedure that, given a package, applies @var{proc} to all the packages
3202 depended on and returns the resulting package. The procedure stops recursion
3203 when @var{cut?} returns true for a given package.
3207 * package Reference :: The package data type.
3208 * origin Reference:: The origin data type.
3212 @node package Reference
3213 @subsection @code{package} Reference
3215 This section summarizes all the options available in @code{package}
3216 declarations (@pxref{Defining Packages}).
3218 @deftp {Data Type} package
3219 This is the data type representing a package recipe.
3223 The name of the package, as a string.
3225 @item @code{version}
3226 The version of the package, as a string.
3229 An object telling how the source code for the package should be
3230 acquired. Most of the time, this is an @code{origin} object, which
3231 denotes a file fetched from the Internet (@pxref{origin Reference}). It
3232 can also be any other ``file-like'' object such as a @code{local-file},
3233 which denotes a file from the local file system (@pxref{G-Expressions,
3234 @code{local-file}}).
3236 @item @code{build-system}
3237 The build system that should be used to build the package (@pxref{Build
3240 @item @code{arguments} (default: @code{'()})
3241 The arguments that should be passed to the build system. This is a
3242 list, typically containing sequential keyword-value pairs.
3244 @item @code{inputs} (default: @code{'()})
3245 @itemx @code{native-inputs} (default: @code{'()})
3246 @itemx @code{propagated-inputs} (default: @code{'()})
3247 @cindex inputs, of packages
3248 These fields list dependencies of the package. Each one is a list of
3249 tuples, where each tuple has a label for the input (a string) as its
3250 first element, a package, origin, or derivation as its second element,
3251 and optionally the name of the output thereof that should be used, which
3252 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
3253 more on package outputs). For example, the list below specifies three
3257 `(("libffi" ,libffi)
3258 ("libunistring" ,libunistring)
3259 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
3262 @cindex cross compilation, package dependencies
3263 The distinction between @code{native-inputs} and @code{inputs} is
3264 necessary when considering cross-compilation. When cross-compiling,
3265 dependencies listed in @code{inputs} are built for the @emph{target}
3266 architecture; conversely, dependencies listed in @code{native-inputs}
3267 are built for the architecture of the @emph{build} machine.
3269 @code{native-inputs} is typically used to list tools needed at
3270 build time, but not at run time, such as Autoconf, Automake, pkg-config,
3271 Gettext, or Bison. @command{guix lint} can report likely mistakes in
3272 this area (@pxref{Invoking guix lint}).
3274 @anchor{package-propagated-inputs}
3275 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
3276 specified packages will be automatically installed alongside the package
3277 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
3278 package}}, for information on how @command{guix package} deals with
3281 For example this is necessary when a C/C++ library needs headers of
3282 another library to compile, or when a pkg-config file refers to another
3283 one @i{via} its @code{Requires} field.
3285 Another example where @code{propagated-inputs} is useful is for languages
3286 that lack a facility to record the run-time search path akin to the
3287 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
3288 more. To ensure that libraries written in those languages can find
3289 library code they depend on at run time, run-time dependencies must be
3290 listed in @code{propagated-inputs} rather than @code{inputs}.
3292 @item @code{self-native-input?} (default: @code{#f})
3293 This is a Boolean field telling whether the package should use itself as
3294 a native input when cross-compiling.
3296 @item @code{outputs} (default: @code{'("out")})
3297 The list of output names of the package. @xref{Packages with Multiple
3298 Outputs}, for typical uses of additional outputs.
3300 @item @code{native-search-paths} (default: @code{'()})
3301 @itemx @code{search-paths} (default: @code{'()})
3302 A list of @code{search-path-specification} objects describing
3303 search-path environment variables honored by the package.
3305 @item @code{replacement} (default: @code{#f})
3306 This must be either @code{#f} or a package object that will be used as a
3307 @dfn{replacement} for this package. @xref{Security Updates, grafts},
3310 @item @code{synopsis}
3311 A one-line description of the package.
3313 @item @code{description}
3314 A more elaborate description of the package.
3316 @item @code{license}
3317 @cindex license, of packages
3318 The license of the package; a value from @code{(guix licenses)},
3319 or a list of such values.
3321 @item @code{home-page}
3322 The URL to the home-page of the package, as a string.
3324 @item @code{supported-systems} (default: @var{%supported-systems})
3325 The list of systems supported by the package, as strings of the form
3326 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
3328 @item @code{maintainers} (default: @code{'()})
3329 The list of maintainers of the package, as @code{maintainer} objects.
3331 @item @code{location} (default: source location of the @code{package} form)
3332 The source location of the package. It is useful to override this when
3333 inheriting from another package, in which case this field is not
3334 automatically corrected.
3339 @node origin Reference
3340 @subsection @code{origin} Reference
3342 This section summarizes all the options available in @code{origin}
3343 declarations (@pxref{Defining Packages}).
3345 @deftp {Data Type} origin
3346 This is the data type representing a source code origin.
3350 An object containing the URI of the source. The object type depends on
3351 the @code{method} (see below). For example, when using the
3352 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
3353 values are: a URL represented as a string, or a list thereof.
3356 A procedure that handles the URI.
3361 @item @var{url-fetch} from @code{(guix download)}
3362 download a file from the HTTP, HTTPS, or FTP URL specified in the
3366 @item @var{git-fetch} from @code{(guix git-download)}
3367 clone the Git version control repository, and check out the revision
3368 specified in the @code{uri} field as a @code{git-reference} object; a
3369 @code{git-reference} looks like this:
3373 (url "git://git.debian.org/git/pkg-shadow/shadow")
3374 (commit "v4.1.5.1"))
3379 A bytevector containing the SHA-256 hash of the source. Typically the
3380 @code{base32} form is used here to generate the bytevector from a
3383 You can obtain this information using @code{guix download}
3384 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
3387 @item @code{file-name} (default: @code{#f})
3388 The file name under which the source code should be saved. When this is
3389 @code{#f}, a sensible default value will be used in most cases. In case
3390 the source is fetched from a URL, the file name from the URL will be
3391 used. For version control checkouts, it is recommended to provide the
3392 file name explicitly because the default is not very descriptive.
3394 @item @code{patches} (default: @code{'()})
3395 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
3396 file-like objects}) pointing to patches to be applied to the source.
3398 This list of patches must be unconditional. In particular, it cannot
3399 depend on the value of @code{%current-system} or
3400 @code{%current-target-system}.
3402 @item @code{snippet} (default: @code{#f})
3403 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
3404 in the source directory. This is a convenient way to modify the source,
3405 sometimes more convenient than a patch.
3407 @item @code{patch-flags} (default: @code{'("-p1")})
3408 A list of command-line flags that should be passed to the @code{patch}
3411 @item @code{patch-inputs} (default: @code{#f})
3412 Input packages or derivations to the patching process. When this is
3413 @code{#f}, the usual set of inputs necessary for patching are provided,
3414 such as GNU@tie{}Patch.
3416 @item @code{modules} (default: @code{'()})
3417 A list of Guile modules that should be loaded during the patching
3418 process and while running the code in the @code{snippet} field.
3420 @item @code{patch-guile} (default: @code{#f})
3421 The Guile package that should be used in the patching process. When
3422 this is @code{#f}, a sensible default is used.
3428 @section Build Systems
3430 @cindex build system
3431 Each package definition specifies a @dfn{build system} and arguments for
3432 that build system (@pxref{Defining Packages}). This @code{build-system}
3433 field represents the build procedure of the package, as well as implicit
3434 dependencies of that build procedure.
3436 Build systems are @code{<build-system>} objects. The interface to
3437 create and manipulate them is provided by the @code{(guix build-system)}
3438 module, and actual build systems are exported by specific modules.
3440 @cindex bag (low-level package representation)
3441 Under the hood, build systems first compile package objects to
3442 @dfn{bags}. A @dfn{bag} is like a package, but with less
3443 ornamentation---in other words, a bag is a lower-level representation of
3444 a package, which includes all the inputs of that package, including some
3445 that were implicitly added by the build system. This intermediate
3446 representation is then compiled to a derivation (@pxref{Derivations}).
3448 Build systems accept an optional list of @dfn{arguments}. In package
3449 definitions, these are passed @i{via} the @code{arguments} field
3450 (@pxref{Defining Packages}). They are typically keyword arguments
3451 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
3452 Guile Reference Manual}). The value of these arguments is usually
3453 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
3454 by the daemon (@pxref{Derivations}).
3456 The main build system is @var{gnu-build-system}, which implements the
3457 standard build procedure for GNU and many other packages. It
3458 is provided by the @code{(guix build-system gnu)} module.
3460 @defvr {Scheme Variable} gnu-build-system
3461 @var{gnu-build-system} represents the GNU Build System, and variants
3462 thereof (@pxref{Configuration, configuration and makefile conventions,,
3463 standards, GNU Coding Standards}).
3465 @cindex build phases
3466 In a nutshell, packages using it are configured, built, and installed with
3467 the usual @code{./configure && make && make check && make install}
3468 command sequence. In practice, a few additional steps are often needed.
3469 All these steps are split up in separate @dfn{phases},
3470 notably@footnote{Please see the @code{(guix build gnu-build-system)}
3471 modules for more details about the build phases.}:
3475 Unpack the source tarball, and change the current directory to the
3476 extracted source tree. If the source is actually a directory, copy it
3477 to the build tree, and enter that directory.
3479 @item patch-source-shebangs
3480 Patch shebangs encountered in source files so they refer to the right
3481 store file names. For instance, this changes @code{#!/bin/sh} to
3482 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
3485 Run the @file{configure} script with a number of default options, such
3486 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
3487 by the @code{#:configure-flags} argument.
3490 Run @code{make} with the list of flags specified with
3491 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
3492 (the default), build with @code{make -j}.
3495 Run @code{make check}, or some other target specified with
3496 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
3497 @code{#:parallel-tests?} argument is true (the default), run @code{make
3501 Run @code{make install} with the flags listed in @code{#:make-flags}.
3503 @item patch-shebangs
3504 Patch shebangs on the installed executable files.
3507 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
3508 is false), copying them to the @code{debug} output when available
3509 (@pxref{Installing Debugging Files}).
3512 @vindex %standard-phases
3513 The build-side module @code{(guix build gnu-build-system)} defines
3514 @var{%standard-phases} as the default list of build phases.
3515 @var{%standard-phases} is a list of symbol/procedure pairs, where the
3516 procedure implements the actual phase.
3518 The list of phases used for a particular package can be changed with the
3519 @code{#:phases} parameter. For instance, passing:
3522 #:phases (modify-phases %standard-phases (delete 'configure))
3525 means that all the phases described above will be used, except the
3526 @code{configure} phase.
3528 In addition, this build system ensures that the ``standard'' environment
3529 for GNU packages is available. This includes tools such as GCC, libc,
3530 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
3531 build-system gnu)} module for a complete list). We call these the
3532 @dfn{implicit inputs} of a package, because package definitions do not
3533 have to mention them.
3536 Other @code{<build-system>} objects are defined to support other
3537 conventions and tools used by free software packages. They inherit most
3538 of @var{gnu-build-system}, and differ mainly in the set of inputs
3539 implicitly added to the build process, and in the list of phases
3540 executed. Some of these build systems are listed below.
3542 @defvr {Scheme Variable} ant-build-system
3543 This variable is exported by @code{(guix build-system ant)}. It
3544 implements the build procedure for Java packages that can be built with
3545 @url{http://ant.apache.org/, Ant build tool}.
3547 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
3548 provided by the @code{icedtea} package to the set of inputs. Different
3549 packages can be specified with the @code{#:ant} and @code{#:jdk}
3550 parameters, respectively.
3552 When the original package does not provide a suitable Ant build file,
3553 the parameter @code{#:jar-name} can be used to generate a minimal Ant
3554 build file @file{build.xml} with tasks to build the specified jar
3555 archive. In this case the parameter @code{#:source-dir} can be used to
3556 specify the source sub-directory, defaulting to ``src''.
3558 The @code{#:main-class} parameter can be used with the minimal ant
3559 buildfile to specify the main class of the resulting jar. This makes the
3560 jar file executable. The @code{#:test-include} parameter can be used to
3561 specify the list of junit tests to run. It defaults to
3562 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
3563 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
3564 because abstract classes cannot be run as tests.
3566 The parameter @code{#:build-target} can be used to specify the Ant task
3567 that should be run during the @code{build} phase. By default the
3568 ``jar'' task will be run.
3572 @defvr {Scheme Variable} asdf-build-system/source
3573 @defvrx {Scheme Variable} asdf-build-system/sbcl
3574 @defvrx {Scheme Variable} asdf-build-system/ecl
3576 These variables, exported by @code{(guix build-system asdf)}, implement
3577 build procedures for Common Lisp packages using
3578 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
3579 definition facility for Common Lisp programs and libraries.
3581 The @code{asdf-build-system/source} system installs the packages in
3582 source form, and can be loaded using any common lisp implementation, via
3583 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
3584 systems in the format which a particular implementation understands.
3585 These build systems can also be used to produce executable programs, or
3586 lisp images which contain a set of packages pre-loaded.
3588 The build system uses naming conventions. For binary packages, the
3589 package name should be prefixed with the lisp implementation, such as
3590 @code{sbcl-} for @code{asdf-build-system/sbcl}.
3592 Additionally, the corresponding source package should be labeled using
3593 the same convention as python packages (see @ref{Python Modules}), using
3594 the @code{cl-} prefix.
3596 For binary packages, each system should be defined as a Guix package.
3597 If one package @code{origin} contains several systems, package variants
3598 can be created in order to build all the systems. Source packages,
3599 which use @code{asdf-build-system/source}, may contain several systems.
3601 In order to create executable programs and images, the build-side
3602 procedures @code{build-program} and @code{build-image} can be used.
3603 They should be called in a build phase after the @code{create-symlinks}
3604 phase, so that the system which was just built can be used within the
3605 resulting image. @code{build-program} requires a list of Common Lisp
3606 expressions to be passed as the @code{#:entry-program} argument.
3608 If the system is not defined within its own @code{.asd} file of the same
3609 name, then the @code{#:asd-file} parameter should be used to specify
3610 which file the system is defined in. Furthermore, if the package
3611 defines a system for its tests in a separate file, it will be loaded
3612 before the tests are run if it is specified by the
3613 @code{#:test-asd-file} parameter. If it is not set, the files
3614 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
3615 and @code{test.asd} will be tried if they exist.
3617 If for some reason the package must be named in a different way than the
3618 naming conventions suggest, the @code{#:asd-system-name} parameter can
3619 be used to specify the name of the system.
3623 @defvr {Scheme Variable} cargo-build-system
3624 @cindex Rust programming language
3625 @cindex Cargo (Rust build system)
3626 This variable is exported by @code{(guix build-system cargo)}. It
3627 supports builds of packages using Cargo, the build tool of the
3628 @uref{https://www.rust-lang.org, Rust programming language}.
3630 In its @code{configure} phase, this build system replaces dependencies
3631 specified in the @file{Carto.toml} file with inputs to the Guix package.
3632 The @code{install} phase installs the binaries, and it also installs the
3633 source code and @file{Cargo.toml} file.
3636 @defvr {Scheme Variable} cmake-build-system
3637 This variable is exported by @code{(guix build-system cmake)}. It
3638 implements the build procedure for packages using the
3639 @url{http://www.cmake.org, CMake build tool}.
3641 It automatically adds the @code{cmake} package to the set of inputs.
3642 Which package is used can be specified with the @code{#:cmake}
3645 The @code{#:configure-flags} parameter is taken as a list of flags
3646 passed to the @command{cmake} command. The @code{#:build-type}
3647 parameter specifies in abstract terms the flags passed to the compiler;
3648 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
3649 debugging information''), which roughly means that code is compiled with
3650 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
3653 @defvr {Scheme Variable} go-build-system
3654 This variable is exported by @code{(guix build-system go)}. It
3655 implements a build procedure for Go packages using the standard
3656 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
3657 Go build mechanisms}.
3659 The user is expected to provide a value for the key @code{#:import-path}
3660 and, in some cases, @code{#:unpack-path}. The
3661 @url{https://golang.org/doc/code.html#ImportPaths, import path}
3662 corresponds to the filesystem path expected by the package's build
3663 scripts and any referring packages, and provides a unique way to
3664 refer to a Go package. It is typically based on a combination of the
3665 package source code's remote URI and filesystem hierarchy structure. In
3666 some cases, you will need to unpack the package's source code to a
3667 different directory structure than the one indicated by the import path,
3668 and @code{#:unpack-path} should be used in such cases.
3670 Packages that provide Go libraries should be installed along with their
3671 source code. The key @code{#:install-source?}, which defaults to
3672 @code{#t}, controls whether or not the source code is installed. It can
3673 be set to @code{#f} for packages that only provide executable files.
3676 @defvr {Scheme Variable} glib-or-gtk-build-system
3677 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
3678 is intended for use with packages making use of GLib or GTK+.
3680 This build system adds the following two phases to the ones defined by
3681 @var{gnu-build-system}:
3684 @item glib-or-gtk-wrap
3685 The phase @code{glib-or-gtk-wrap} ensures that programs in
3686 @file{bin/} are able to find GLib ``schemas'' and
3687 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
3688 modules}. This is achieved by wrapping the programs in launch scripts
3689 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
3690 environment variables.
3692 It is possible to exclude specific package outputs from that wrapping
3693 process by listing their names in the
3694 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
3695 when an output is known not to contain any GLib or GTK+ binaries, and
3696 where wrapping would gratuitously add a dependency of that output on
3699 @item glib-or-gtk-compile-schemas
3700 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
3701 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
3702 GSettings schemas} of GLib are compiled. Compilation is performed by the
3703 @command{glib-compile-schemas} program. It is provided by the package
3704 @code{glib:bin} which is automatically imported by the build system.
3705 The @code{glib} package providing @command{glib-compile-schemas} can be
3706 specified with the @code{#:glib} parameter.
3709 Both phases are executed after the @code{install} phase.
3712 @defvr {Scheme Variable} minify-build-system
3713 This variable is exported by @code{(guix build-system minify)}. It
3714 implements a minification procedure for simple JavaScript packages.
3716 It adds @code{uglify-js} to the set of inputs and uses it to compress
3717 all JavaScript files in the @file{src} directory. A different minifier
3718 package can be specified with the @code{#:uglify-js} parameter, but it
3719 is expected that the package writes the minified code to the standard
3722 When the input JavaScript files are not all located in the @file{src}
3723 directory, the parameter @code{#:javascript-files} can be used to
3724 specify a list of file names to feed to the minifier.
3727 @defvr {Scheme Variable} ocaml-build-system
3728 This variable is exported by @code{(guix build-system ocaml)}. It implements
3729 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
3730 of choosing the correct set of commands to run for each package. OCaml
3731 packages can expect many different commands to be run. This build system will
3734 When the package has a @file{setup.ml} file present at the top-level, it will
3735 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
3736 @code{ocaml setup.ml -install}. The build system will assume that this file
3737 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
3738 care of setting the prefix and enabling tests if they are not disabled. You
3739 can pass configure and build flags with the @code{#:configure-flags} and
3740 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
3741 set of flags used to enable tests. The @code{#:use-make?} key can be used to
3742 bypass this system in the build and install phases.
3744 When the package has a @file{configure} file, it is assumed that it is a
3745 hand-made configure script that requires a different argument format than
3746 in the @code{gnu-build-system}. You can add more flags with the
3747 @code{#:configure-flags} key.
3749 When the package has a @file{Makefile} file (or @code{#:use-make?} is
3750 @code{#t}), it will be used and more flags can be passed to the build and
3751 install phases with the @code{#:make-flags} key.
3753 Finally, some packages do not have these files and use a somewhat standard
3754 location for its build system. In that case, the build system will run
3755 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
3756 providing the path to the required findlib module. Additional flags can
3757 be passed via the @code{#:build-flags} key. Install is taken care of by
3758 @command{opam-installer}. In this case, the @code{opam} package must
3759 be added to the @code{native-inputs} field of the package definition.
3761 Note that most OCaml packages assume they will be installed in the same
3762 directory as OCaml, which is not what we want in guix. In particular, they
3763 will install @file{.so} files in their module's directory, which is usually
3764 fine because it is in the OCaml compiler directory. In guix though, these
3765 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
3766 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
3767 @file{.so} libraries should be installed.
3770 @defvr {Scheme Variable} python-build-system
3771 This variable is exported by @code{(guix build-system python)}. It
3772 implements the more or less standard build procedure used by Python
3773 packages, which consists in running @code{python setup.py build} and
3774 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
3776 For packages that install stand-alone Python programs under @code{bin/},
3777 it takes care of wrapping these programs so that their @code{PYTHONPATH}
3778 environment variable points to all the Python libraries they depend on.
3780 Which Python package is used to perform the build can be specified with
3781 the @code{#:python} parameter. This is a useful way to force a package
3782 to be built for a specific version of the Python interpreter, which
3783 might be necessary if the package is only compatible with a single
3784 interpreter version.
3786 By default guix calls @code{setup.py} under control of
3787 @code{setuptools}, much like @command{pip} does. Some packages are not
3788 compatible with setuptools (and pip), thus you can disable this by
3789 setting the @code{#:use-setuptools} parameter to @code{#f}.
3792 @defvr {Scheme Variable} perl-build-system
3793 This variable is exported by @code{(guix build-system perl)}. It
3794 implements the standard build procedure for Perl packages, which either
3795 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
3796 followed by @code{Build} and @code{Build install}; or in running
3797 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
3798 @code{make} and @code{make install}, depending on which of
3799 @code{Build.PL} or @code{Makefile.PL} is present in the package
3800 distribution. Preference is given to the former if both @code{Build.PL}
3801 and @code{Makefile.PL} exist in the package distribution. This
3802 preference can be reversed by specifying @code{#t} for the
3803 @code{#:make-maker?} parameter.
3805 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
3806 passes flags specified by the @code{#:make-maker-flags} or
3807 @code{#:module-build-flags} parameter, respectively.
3809 Which Perl package is used can be specified with @code{#:perl}.
3812 @defvr {Scheme Variable} r-build-system
3813 This variable is exported by @code{(guix build-system r)}. It
3814 implements the build procedure used by @uref{http://r-project.org, R}
3815 packages, which essentially is little more than running @code{R CMD
3816 INSTALL --library=/gnu/store/@dots{}} in an environment where
3817 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
3818 are run after installation using the R function
3819 @code{tools::testInstalledPackage}.
3822 @defvr {Scheme Variable} texlive-build-system
3823 This variable is exported by @code{(guix build-system texlive)}. It is
3824 used to build TeX packages in batch mode with a specified engine. The
3825 build system sets the @code{TEXINPUTS} variable to find all TeX source
3826 files in the inputs.
3828 By default it runs @code{luatex} on all files ending on @code{ins}. A
3829 different engine and format can be specified with the
3830 @code{#:tex-format} argument. Different build targets can be specified
3831 with the @code{#:build-targets} argument, which expects a list of file
3832 names. The build system adds only @code{texlive-bin} and
3833 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
3834 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
3835 and @code{#:texlive-latex-base}, respectively.
3837 The @code{#:tex-directory} parameter tells the build system where to
3838 install the built files under the texmf tree.
3841 @defvr {Scheme Variable} ruby-build-system
3842 This variable is exported by @code{(guix build-system ruby)}. It
3843 implements the RubyGems build procedure used by Ruby packages, which
3844 involves running @code{gem build} followed by @code{gem install}.
3846 The @code{source} field of a package that uses this build system
3847 typically references a gem archive, since this is the format that Ruby
3848 developers use when releasing their software. The build system unpacks
3849 the gem archive, potentially patches the source, runs the test suite,
3850 repackages the gem, and installs it. Additionally, directories and
3851 tarballs may be referenced to allow building unreleased gems from Git or
3852 a traditional source release tarball.
3854 Which Ruby package is used can be specified with the @code{#:ruby}
3855 parameter. A list of additional flags to be passed to the @command{gem}
3856 command can be specified with the @code{#:gem-flags} parameter.
3859 @defvr {Scheme Variable} waf-build-system
3860 This variable is exported by @code{(guix build-system waf)}. It
3861 implements a build procedure around the @code{waf} script. The common
3862 phases---@code{configure}, @code{build}, and @code{install}---are
3863 implemented by passing their names as arguments to the @code{waf}
3866 The @code{waf} script is executed by the Python interpreter. Which
3867 Python package is used to run the script can be specified with the
3868 @code{#:python} parameter.
3871 @defvr {Scheme Variable} haskell-build-system
3872 This variable is exported by @code{(guix build-system haskell)}. It
3873 implements the Cabal build procedure used by Haskell packages, which
3874 involves running @code{runhaskell Setup.hs configure
3875 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
3876 Instead of installing the package by running @code{runhaskell Setup.hs
3877 install}, to avoid trying to register libraries in the read-only
3878 compiler store directory, the build system uses @code{runhaskell
3879 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
3880 addition, the build system generates the package documentation by
3881 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
3882 is passed. Optional Haddock parameters can be passed with the help of
3883 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
3884 not found, the build system looks for @code{Setup.lhs} instead.
3886 Which Haskell compiler is used can be specified with the @code{#:haskell}
3887 parameter which defaults to @code{ghc}.
3890 @defvr {Scheme Variable} dub-build-system
3891 This variable is exported by @code{(guix build-system dub)}. It
3892 implements the Dub build procedure used by D packages, which
3893 involves running @code{dub build} and @code{dub run}.
3894 Installation is done by copying the files manually.
3896 Which D compiler is used can be specified with the @code{#:ldc}
3897 parameter which defaults to @code{ldc}.
3900 @defvr {Scheme Variable} emacs-build-system
3901 This variable is exported by @code{(guix build-system emacs)}. It
3902 implements an installation procedure similar to the packaging system
3903 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
3905 It first creates the @code{@var{package}-autoloads.el} file, then it
3906 byte compiles all Emacs Lisp files. Differently from the Emacs
3907 packaging system, the Info documentation files are moved to the standard
3908 documentation directory and the @file{dir} file is deleted. Each
3909 package is installed in its own directory under
3910 @file{share/emacs/site-lisp/guix.d}.
3913 @defvr {Scheme Variable} font-build-system
3914 This variable is exported by @code{(guix build-system font)}. It
3915 implements an installation procedure for font packages where upstream
3916 provides pre-compiled TrueType, OpenType, etc. font files that merely
3917 need to be copied into place. It copies font files to standard
3918 locations in the output directory.
3921 @defvr {Scheme Variable} meson-build-system
3922 This variable is exported by @code{(guix build-system meson)}. It
3923 implements the build procedure for packages that use
3924 @url{http://mesonbuild.com, Meson} as their build system.
3926 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
3927 of inputs, and they can be changed with the parameters @code{#:meson}
3928 and @code{#:ninja} if needed. The default Meson is
3929 @code{meson-for-build}, which is special because it doesn't clear the
3930 @code{RUNPATH} of binaries and libraries when they are installed.
3932 This build system is an extension of @var{gnu-build-system}, but with the
3933 following phases changed to some specific for Meson:
3938 The phase runs @code{meson} with the flags specified in
3939 @code{#:configure-flags}. The flag @code{--build-type} is always set to
3940 @code{plain} unless something else is specified in @code{#:build-type}.
3943 The phase runs @code{ninja} to build the package in parallel by default, but
3944 this can be changed with @code{#:parallel-build?}.
3947 The phase runs @code{ninja} with the target specified in @code{#:test-target},
3948 which is @code{"test"} by default.
3951 The phase runs @code{ninja install} and can not be changed.
3954 Apart from that, the build system also adds the following phases:
3959 This phase tries to locate the local directories in the package being build,
3960 which has libraries that some of the binaries need. If any are found, they will
3961 be added to the programs @code{RUNPATH}. It is needed because
3962 @code{meson-for-build} keeps the @code{RUNPATH} of binaries and libraries from
3963 when they are build, but often that is not the @code{RUNPATH} we want.
3964 Therefor it is also shrinked to the minimum needed by the program.
3966 @item glib-or-gtk-wrap
3967 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
3968 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
3970 @item glib-or-gtk-compile-schemas
3971 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
3972 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
3976 Lastly, for packages that do not need anything as sophisticated, a
3977 ``trivial'' build system is provided. It is trivial in the sense that
3978 it provides basically no support: it does not pull any implicit inputs,
3979 and does not have a notion of build phases.
3981 @defvr {Scheme Variable} trivial-build-system
3982 This variable is exported by @code{(guix build-system trivial)}.
3984 This build system requires a @code{#:builder} argument. This argument
3985 must be a Scheme expression that builds the package output(s)---as
3986 with @code{build-expression->derivation} (@pxref{Derivations,
3987 @code{build-expression->derivation}}).
3997 Conceptually, the @dfn{store} is the place where derivations that have
3998 been built successfully are stored---by default, @file{/gnu/store}.
3999 Sub-directories in the store are referred to as @dfn{store items} or
4000 sometimes @dfn{store paths}. The store has an associated database that
4001 contains information such as the store paths referred to by each store
4002 path, and the list of @emph{valid} store items---results of successful
4003 builds. This database resides in @file{@var{localstatedir}/guix/db},
4004 where @var{localstatedir} is the state directory specified @i{via}
4005 @option{--localstatedir} at configure time, usually @file{/var}.
4007 The store is @emph{always} accessed by the daemon on behalf of its clients
4008 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
4009 connect to the daemon over a Unix-domain socket, send requests to it,
4010 and read the result---these are remote procedure calls, or RPCs.
4013 Users must @emph{never} modify files under @file{/gnu/store} directly.
4014 This would lead to inconsistencies and break the immutability
4015 assumptions of Guix's functional model (@pxref{Introduction}).
4017 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
4018 how to check the integrity of the store and attempt recovery from
4019 accidental modifications.
4022 The @code{(guix store)} module provides procedures to connect to the
4023 daemon, and to perform RPCs. These are described below. By default,
4024 @code{open-connection}, and thus all the @command{guix} commands,
4025 connect to the local daemon or to the URI specified by the
4026 @code{GUIX_DAEMON_SOCKET} environment variable.
4028 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
4029 When set, the value of this variable should be a file name or a URI
4030 designating the daemon endpoint. When it is a file name, it denotes a
4031 Unix-domain socket to connect to. In addition to file names, the
4032 supported URI schemes are:
4037 These are for Unix-domain sockets.
4038 @code{file:///var/guix/daemon-socket/socket} is equivalent to
4039 @file{/var/guix/daemon-socket/socket}.
4042 @cindex daemon, remote access
4043 @cindex remote access to the daemon
4044 @cindex daemon, cluster setup
4045 @cindex clusters, daemon setup
4046 These URIs denote connections over TCP/IP, without encryption nor
4047 authentication of the remote host. The URI must specify the host name
4048 and optionally a port number (by default port 44146 is used):
4051 guix://master.guix.example.org:1234
4054 This setup is suitable on local networks, such as clusters, where only
4055 trusted nodes may connect to the build daemon at
4056 @code{master.guix.example.org}.
4058 The @code{--listen} option of @command{guix-daemon} can be used to
4059 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
4063 @cindex SSH access to build daemons
4064 These URIs allow you to connect to a remote daemon over
4065 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
4066 A typical URL might look like this:
4069 ssh://charlie@@guix.example.org:22
4072 As for @command{guix copy}, the usual OpenSSH client configuration files
4073 are honored (@pxref{Invoking guix copy}).
4076 Additional URI schemes may be supported in the future.
4078 @c XXX: Remove this note when the protocol incurs fewer round trips
4079 @c and when (guix derivations) no longer relies on file system access.
4081 The ability to connect to remote build daemons is considered
4082 experimental as of @value{VERSION}. Please get in touch with us to
4083 share any problems or suggestions you may have (@pxref{Contributing}).
4087 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
4088 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
4089 @var{reserve-space?} is true, instruct it to reserve a little bit of
4090 extra space on the file system so that the garbage collector can still
4091 operate should the disk become full. Return a server object.
4093 @var{file} defaults to @var{%default-socket-path}, which is the normal
4094 location given the options that were passed to @command{configure}.
4097 @deffn {Scheme Procedure} close-connection @var{server}
4098 Close the connection to @var{server}.
4101 @defvr {Scheme Variable} current-build-output-port
4102 This variable is bound to a SRFI-39 parameter, which refers to the port
4103 where build and error logs sent by the daemon should be written.
4106 Procedures that make RPCs all take a server object as their first
4109 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
4110 @cindex invalid store items
4111 Return @code{#t} when @var{path} designates a valid store item and
4112 @code{#f} otherwise (an invalid item may exist on disk but still be
4113 invalid, for instance because it is the result of an aborted or failed
4116 A @code{&nix-protocol-error} condition is raised if @var{path} is not
4117 prefixed by the store directory (@file{/gnu/store}).
4120 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
4121 Add @var{text} under file @var{name} in the store, and return its store
4122 path. @var{references} is the list of store paths referred to by the
4123 resulting store path.
4126 @deffn {Scheme Procedure} build-derivations @var{server} @var{derivations}
4127 Build @var{derivations} (a list of @code{<derivation>} objects or
4128 derivation paths), and return when the worker is done building them.
4129 Return @code{#t} on success.
4132 Note that the @code{(guix monads)} module provides a monad as well as
4133 monadic versions of the above procedures, with the goal of making it
4134 more convenient to work with code that accesses the store (@pxref{The
4138 @i{This section is currently incomplete.}
4141 @section Derivations
4144 Low-level build actions and the environment in which they are performed
4145 are represented by @dfn{derivations}. A derivation contains the
4146 following pieces of information:
4150 The outputs of the derivation---derivations produce at least one file or
4151 directory in the store, but may produce more.
4154 The inputs of the derivations, which may be other derivations or plain
4155 files in the store (patches, build scripts, etc.)
4158 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
4161 The file name of a build script in the store, along with the arguments
4165 A list of environment variables to be defined.
4169 @cindex derivation path
4170 Derivations allow clients of the daemon to communicate build actions to
4171 the store. They exist in two forms: as an in-memory representation,
4172 both on the client- and daemon-side, and as files in the store whose
4173 name end in @code{.drv}---these files are referred to as @dfn{derivation
4174 paths}. Derivations paths can be passed to the @code{build-derivations}
4175 procedure to perform the build actions they prescribe (@pxref{The
4178 The @code{(guix derivations)} module provides a representation of
4179 derivations as Scheme objects, along with procedures to create and
4180 otherwise manipulate derivations. The lowest-level primitive to create
4181 a derivation is the @code{derivation} procedure:
4183 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
4184 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
4185 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
4186 [#:system (%current-system)] [#:references-graphs #f] @
4187 [#:allowed-references #f] [#:disallowed-references #f] @
4188 [#:leaked-env-vars #f] [#:local-build? #f] @
4189 [#:substitutable? #t]
4190 Build a derivation with the given arguments, and return the resulting
4191 @code{<derivation>} object.
4193 When @var{hash} and @var{hash-algo} are given, a
4194 @dfn{fixed-output derivation} is created---i.e., one whose result is
4195 known in advance, such as a file download. If, in addition,
4196 @var{recursive?} is true, then that fixed output may be an executable
4197 file or a directory and @var{hash} must be the hash of an archive
4198 containing this output.
4200 When @var{references-graphs} is true, it must be a list of file
4201 name/store path pairs. In that case, the reference graph of each store
4202 path is exported in the build environment in the corresponding file, in
4203 a simple text format.
4205 When @var{allowed-references} is true, it must be a list of store items
4206 or outputs that the derivation's output may refer to. Likewise,
4207 @var{disallowed-references}, if true, must be a list of things the
4208 outputs may @emph{not} refer to.
4210 When @var{leaked-env-vars} is true, it must be a list of strings
4211 denoting environment variables that are allowed to ``leak'' from the
4212 daemon's environment to the build environment. This is only applicable
4213 to fixed-output derivations---i.e., when @var{hash} is true. The main
4214 use is to allow variables such as @code{http_proxy} to be passed to
4215 derivations that download files.
4217 When @var{local-build?} is true, declare that the derivation is not a
4218 good candidate for offloading and should rather be built locally
4219 (@pxref{Daemon Offload Setup}). This is the case for small derivations
4220 where the costs of data transfers would outweigh the benefits.
4222 When @var{substitutable?} is false, declare that substitutes of the
4223 derivation's output should not be used (@pxref{Substitutes}). This is
4224 useful, for instance, when building packages that capture details of the
4225 host CPU instruction set.
4229 Here's an example with a shell script as its builder, assuming
4230 @var{store} is an open connection to the daemon, and @var{bash} points
4231 to a Bash executable in the store:
4234 (use-modules (guix utils)
4238 (let ((builder ; add the Bash script to the store
4239 (add-text-to-store store "my-builder.sh"
4240 "echo hello world > $out\n" '())))
4241 (derivation store "foo"
4242 bash `("-e" ,builder)
4243 #:inputs `((,bash) (,builder))
4244 #:env-vars '(("HOME" . "/homeless"))))
4245 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
4248 As can be guessed, this primitive is cumbersome to use directly. A
4249 better approach is to write build scripts in Scheme, of course! The
4250 best course of action for that is to write the build code as a
4251 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
4252 information, @pxref{G-Expressions}.
4254 Once upon a time, @code{gexp->derivation} did not exist and constructing
4255 derivations with build code written in Scheme was achieved with
4256 @code{build-expression->derivation}, documented below. This procedure
4257 is now deprecated in favor of the much nicer @code{gexp->derivation}.
4259 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
4260 @var{name} @var{exp} @
4261 [#:system (%current-system)] [#:inputs '()] @
4262 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
4263 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
4264 [#:references-graphs #f] [#:allowed-references #f] @
4265 [#:disallowed-references #f] @
4266 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
4267 Return a derivation that executes Scheme expression @var{exp} as a
4268 builder for derivation @var{name}. @var{inputs} must be a list of
4269 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
4270 @code{"out"} is assumed. @var{modules} is a list of names of Guile
4271 modules from the current search path to be copied in the store,
4272 compiled, and made available in the load path during the execution of
4273 @var{exp}---e.g., @code{((guix build utils) (guix build
4274 gnu-build-system))}.
4276 @var{exp} is evaluated in an environment where @code{%outputs} is bound
4277 to a list of output/path pairs, and where @code{%build-inputs} is bound
4278 to a list of string/output-path pairs made from @var{inputs}.
4279 Optionally, @var{env-vars} is a list of string pairs specifying the name
4280 and value of environment variables visible to the builder. The builder
4281 terminates by passing the result of @var{exp} to @code{exit}; thus, when
4282 @var{exp} returns @code{#f}, the build is considered to have failed.
4284 @var{exp} is built using @var{guile-for-build} (a derivation). When
4285 @var{guile-for-build} is omitted or is @code{#f}, the value of the
4286 @code{%guile-for-build} fluid is used instead.
4288 See the @code{derivation} procedure for the meaning of
4289 @var{references-graphs}, @var{allowed-references},
4290 @var{disallowed-references}, @var{local-build?}, and
4291 @var{substitutable?}.
4295 Here's an example of a single-output derivation that creates a directory
4296 containing one file:
4299 (let ((builder '(let ((out (assoc-ref %outputs "out")))
4300 (mkdir out) ; create /gnu/store/@dots{}-goo
4301 (call-with-output-file (string-append out "/test")
4303 (display '(hello guix) p))))))
4304 (build-expression->derivation store "goo" builder))
4306 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
4310 @node The Store Monad
4311 @section The Store Monad
4315 The procedures that operate on the store described in the previous
4316 sections all take an open connection to the build daemon as their first
4317 argument. Although the underlying model is functional, they either have
4318 side effects or depend on the current state of the store.
4320 The former is inconvenient: the connection to the build daemon has to be
4321 carried around in all those functions, making it impossible to compose
4322 functions that do not take that parameter with functions that do. The
4323 latter can be problematic: since store operations have side effects
4324 and/or depend on external state, they have to be properly sequenced.
4326 @cindex monadic values
4327 @cindex monadic functions
4328 This is where the @code{(guix monads)} module comes in. This module
4329 provides a framework for working with @dfn{monads}, and a particularly
4330 useful monad for our uses, the @dfn{store monad}. Monads are a
4331 construct that allows two things: associating ``context'' with values
4332 (in our case, the context is the store), and building sequences of
4333 computations (here computations include accesses to the store). Values
4334 in a monad---values that carry this additional context---are called
4335 @dfn{monadic values}; procedures that return such values are called
4336 @dfn{monadic procedures}.
4338 Consider this ``normal'' procedure:
4341 (define (sh-symlink store)
4342 ;; Return a derivation that symlinks the 'bash' executable.
4343 (let* ((drv (package-derivation store bash))
4344 (out (derivation->output-path drv))
4345 (sh (string-append out "/bin/bash")))
4346 (build-expression->derivation store "sh"
4347 `(symlink ,sh %output))))
4350 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
4351 as a monadic function:
4354 (define (sh-symlink)
4355 ;; Same, but return a monadic value.
4356 (mlet %store-monad ((drv (package->derivation bash)))
4357 (gexp->derivation "sh"
4358 #~(symlink (string-append #$drv "/bin/bash")
4362 There are several things to note in the second version: the @code{store}
4363 parameter is now implicit and is ``threaded'' in the calls to the
4364 @code{package->derivation} and @code{gexp->derivation} monadic
4365 procedures, and the monadic value returned by @code{package->derivation}
4366 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
4368 As it turns out, the call to @code{package->derivation} can even be
4369 omitted since it will take place implicitly, as we will see later
4370 (@pxref{G-Expressions}):
4373 (define (sh-symlink)
4374 (gexp->derivation "sh"
4375 #~(symlink (string-append #$bash "/bin/bash")
4380 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
4381 @c for the funny quote.
4382 Calling the monadic @code{sh-symlink} has no effect. As someone once
4383 said, ``you exit a monad like you exit a building on fire: by running''.
4384 So, to exit the monad and get the desired effect, one must use
4385 @code{run-with-store}:
4388 (run-with-store (open-connection) (sh-symlink))
4389 @result{} /gnu/store/...-sh-symlink
4392 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
4393 new ``meta-commands'' to make it easier to deal with monadic procedures:
4394 @code{run-in-store}, and @code{enter-store-monad}. The former is used
4395 to ``run'' a single monadic value through the store:
4398 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
4399 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
4402 The latter enters a recursive REPL, where all the return values are
4403 automatically run through the store:
4406 scheme@@(guile-user)> ,enter-store-monad
4407 store-monad@@(guile-user) [1]> (package->derivation hello)
4408 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
4409 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
4410 $3 = "/gnu/store/@dots{}-foo"
4411 store-monad@@(guile-user) [1]> ,q
4412 scheme@@(guile-user)>
4416 Note that non-monadic values cannot be returned in the
4417 @code{store-monad} REPL.
4419 The main syntactic forms to deal with monads in general are provided by
4420 the @code{(guix monads)} module and are described below.
4422 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
4423 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
4427 @deffn {Scheme Syntax} return @var{val}
4428 Return a monadic value that encapsulates @var{val}.
4431 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
4432 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
4433 procedures @var{mproc}@dots{}@footnote{This operation is commonly
4434 referred to as ``bind'', but that name denotes an unrelated procedure in
4435 Guile. Thus we use this somewhat cryptic symbol inherited from the
4436 Haskell language.}. There can be one @var{mproc} or several of them, as
4441 (with-monad %state-monad
4443 (lambda (x) (return (+ 1 x)))
4444 (lambda (x) (return (* 2 x)))))
4448 @result{} some-state
4452 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
4454 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
4456 Bind the variables @var{var} to the monadic values @var{mval} in
4457 @var{body}, which is a sequence of expressions. As with the bind
4458 operator, this can be thought of as ``unpacking'' the raw, non-monadic
4459 value ``contained'' in @var{mval} and making @var{var} refer to that
4460 raw, non-monadic value within the scope of the @var{body}. The form
4461 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
4462 @var{val}, as per @code{let}. The binding operations occur in sequence
4463 from left to right. The last expression of @var{body} must be a monadic
4464 expression, and its result will become the result of the @code{mlet} or
4465 @code{mlet*} when run in the @var{monad}.
4467 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
4468 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
4471 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
4472 Bind @var{mexp} and the following monadic expressions in sequence,
4473 returning the result of the last expression. Every expression in the
4474 sequence must be a monadic expression.
4476 This is akin to @code{mlet}, except that the return values of the
4477 monadic expressions are ignored. In that sense, it is analogous to
4478 @code{begin}, but applied to monadic expressions.
4481 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
4482 When @var{condition} is true, evaluate the sequence of monadic
4483 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
4484 @var{condition} is false, return @code{*unspecified*} in the current
4485 monad. Every expression in the sequence must be a monadic expression.
4488 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
4489 When @var{condition} is false, evaluate the sequence of monadic
4490 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
4491 @var{condition} is true, return @code{*unspecified*} in the current
4492 monad. Every expression in the sequence must be a monadic expression.
4496 The @code{(guix monads)} module provides the @dfn{state monad}, which
4497 allows an additional value---the state---to be @emph{threaded} through
4498 monadic procedure calls.
4500 @defvr {Scheme Variable} %state-monad
4501 The state monad. Procedures in the state monad can access and change
4502 the state that is threaded.
4504 Consider the example below. The @code{square} procedure returns a value
4505 in the state monad. It returns the square of its argument, but also
4506 increments the current state value:
4510 (mlet %state-monad ((count (current-state)))
4511 (mbegin %state-monad
4512 (set-current-state (+ 1 count))
4515 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
4520 When ``run'' through @var{%state-monad}, we obtain that additional state
4521 value, which is the number of @code{square} calls.
4524 @deffn {Monadic Procedure} current-state
4525 Return the current state as a monadic value.
4528 @deffn {Monadic Procedure} set-current-state @var{value}
4529 Set the current state to @var{value} and return the previous state as a
4533 @deffn {Monadic Procedure} state-push @var{value}
4534 Push @var{value} to the current state, which is assumed to be a list,
4535 and return the previous state as a monadic value.
4538 @deffn {Monadic Procedure} state-pop
4539 Pop a value from the current state and return it as a monadic value.
4540 The state is assumed to be a list.
4543 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
4544 Run monadic value @var{mval} starting with @var{state} as the initial
4545 state. Return two values: the resulting value, and the resulting state.
4548 The main interface to the store monad, provided by the @code{(guix
4549 store)} module, is as follows.
4551 @defvr {Scheme Variable} %store-monad
4552 The store monad---an alias for @var{%state-monad}.
4554 Values in the store monad encapsulate accesses to the store. When its
4555 effect is needed, a value of the store monad must be ``evaluated'' by
4556 passing it to the @code{run-with-store} procedure (see below.)
4559 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
4560 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
4561 open store connection.
4564 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
4565 Return as a monadic value the absolute file name in the store of the file
4566 containing @var{text}, a string. @var{references} is a list of store items that the
4567 resulting text file refers to; it defaults to the empty list.
4570 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
4571 [#:recursive? #t] [#:select? (const #t)]
4572 Return the name of @var{file} once interned in the store. Use
4573 @var{name} as its store name, or the basename of @var{file} if
4574 @var{name} is omitted.
4576 When @var{recursive?} is true, the contents of @var{file} are added
4577 recursively; if @var{file} designates a flat file and @var{recursive?}
4578 is true, its contents are added, and its permission bits are kept.
4580 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
4581 @var{stat})} for each directory entry, where @var{file} is the entry's
4582 absolute file name and @var{stat} is the result of @code{lstat}; exclude
4583 entries for which @var{select?} does not return true.
4585 The example below adds a file to the store, under two different names:
4588 (run-with-store (open-connection)
4589 (mlet %store-monad ((a (interned-file "README"))
4590 (b (interned-file "README" "LEGU-MIN")))
4591 (return (list a b))))
4593 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
4598 The @code{(guix packages)} module exports the following package-related
4601 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
4602 [#:system (%current-system)] [#:target #f] @
4605 value in the absolute file name of @var{file} within the @var{output}
4606 directory of @var{package}. When @var{file} is omitted, return the name
4607 of the @var{output} directory of @var{package}. When @var{target} is
4608 true, use it as a cross-compilation target triplet.
4611 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
4612 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
4613 @var{target} [@var{system}]
4614 Monadic version of @code{package-derivation} and
4615 @code{package-cross-derivation} (@pxref{Defining Packages}).
4620 @section G-Expressions
4622 @cindex G-expression
4623 @cindex build code quoting
4624 So we have ``derivations'', which represent a sequence of build actions
4625 to be performed to produce an item in the store (@pxref{Derivations}).
4626 These build actions are performed when asking the daemon to actually
4627 build the derivations; they are run by the daemon in a container
4628 (@pxref{Invoking guix-daemon}).
4630 @cindex strata of code
4631 It should come as no surprise that we like to write these build actions
4632 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
4633 code@footnote{The term @dfn{stratum} in this context was coined by
4634 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
4635 Kiselyov, who has written insightful
4636 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
4637 on this topic}, refers to this kind of code generation as
4638 @dfn{staging}.}: the ``host code''---code that defines packages, talks
4639 to the daemon, etc.---and the ``build code''---code that actually
4640 performs build actions, such as making directories, invoking
4641 @command{make}, etc.
4643 To describe a derivation and its build actions, one typically needs to
4644 embed build code inside host code. It boils down to manipulating build
4645 code as data, and the homoiconicity of Scheme---code has a direct
4646 representation as data---comes in handy for that. But we need more than
4647 the normal @code{quasiquote} mechanism in Scheme to construct build
4650 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
4651 S-expressions adapted to build expressions. G-expressions, or
4652 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
4653 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
4654 @code{#$}, and @code{#$@@}), which are comparable to
4655 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
4656 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
4657 GNU Guile Reference Manual}). However, there are major differences:
4661 Gexps are meant to be written to a file and run or manipulated by other
4665 When a high-level object such as a package or derivation is unquoted
4666 inside a gexp, the result is as if its output file name had been
4670 Gexps carry information about the packages or derivations they refer to,
4671 and these dependencies are automatically added as inputs to the build
4672 processes that use them.
4675 @cindex lowering, of high-level objects in gexps
4676 This mechanism is not limited to package and derivation
4677 objects: @dfn{compilers} able to ``lower'' other high-level objects to
4678 derivations or files in the store can be defined,
4679 such that these objects can also be inserted
4680 into gexps. For example, a useful type of high-level objects that can be
4681 inserted in a gexp is ``file-like objects'', which make it easy to
4682 add files to the store and to refer to them in
4683 derivations and such (see @code{local-file} and @code{plain-file}
4686 To illustrate the idea, here is an example of a gexp:
4693 (symlink (string-append #$coreutils "/bin/ls")
4697 This gexp can be passed to @code{gexp->derivation}; we obtain a
4698 derivation that builds a directory containing exactly one symlink to
4699 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
4702 (gexp->derivation "the-thing" build-exp)
4705 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
4706 substituted to the reference to the @var{coreutils} package in the
4707 actual build code, and @var{coreutils} is automatically made an input to
4708 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
4709 output)}) is replaced by a string containing the directory name of the
4710 output of the derivation.
4712 @cindex cross compilation
4713 In a cross-compilation context, it is useful to distinguish between
4714 references to the @emph{native} build of a package---that can run on the
4715 host---versus references to cross builds of a package. To that end, the
4716 @code{#+} plays the same role as @code{#$}, but is a reference to a
4717 native package build:
4720 (gexp->derivation "vi"
4723 (system* (string-append #+coreutils "/bin/ln")
4725 (string-append #$emacs "/bin/emacs")
4726 (string-append #$output "/bin/vi")))
4727 #:target "mips64el-linux-gnu")
4731 In the example above, the native build of @var{coreutils} is used, so
4732 that @command{ln} can actually run on the host; but then the
4733 cross-compiled build of @var{emacs} is referenced.
4735 @cindex imported modules, for gexps
4736 @findex with-imported-modules
4737 Another gexp feature is @dfn{imported modules}: sometimes you want to be
4738 able to use certain Guile modules from the ``host environment'' in the
4739 gexp, so those modules should be imported in the ``build environment''.
4740 The @code{with-imported-modules} form allows you to express that:
4743 (let ((build (with-imported-modules '((guix build utils))
4745 (use-modules (guix build utils))
4746 (mkdir-p (string-append #$output "/bin"))))))
4747 (gexp->derivation "empty-dir"
4750 (display "success!\n")
4755 In this example, the @code{(guix build utils)} module is automatically
4756 pulled into the isolated build environment of our gexp, such that
4757 @code{(use-modules (guix build utils))} works as expected.
4759 @cindex module closure
4760 @findex source-module-closure
4761 Usually you want the @emph{closure} of the module to be imported---i.e.,
4762 the module itself and all the modules it depends on---rather than just
4763 the module; failing to do that, attempts to use the module will fail
4764 because of missing dependent modules. The @code{source-module-closure}
4765 procedure computes the closure of a module by looking at its source file
4766 headers, which comes in handy in this case:
4769 (use-modules (guix modules)) ;for 'source-module-closure'
4771 (with-imported-modules (source-module-closure
4772 '((guix build utils)
4774 (gexp->derivation "something-with-vms"
4776 (use-modules (guix build utils)
4781 The syntactic form to construct gexps is summarized below.
4783 @deffn {Scheme Syntax} #~@var{exp}
4784 @deffnx {Scheme Syntax} (gexp @var{exp})
4785 Return a G-expression containing @var{exp}. @var{exp} may contain one
4786 or more of the following forms:
4790 @itemx (ungexp @var{obj})
4791 Introduce a reference to @var{obj}. @var{obj} may have one of the
4792 supported types, for example a package or a
4793 derivation, in which case the @code{ungexp} form is replaced by its
4794 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
4796 If @var{obj} is a list, it is traversed and references to supported
4797 objects are substituted similarly.
4799 If @var{obj} is another gexp, its contents are inserted and its
4800 dependencies are added to those of the containing gexp.
4802 If @var{obj} is another kind of object, it is inserted as is.
4804 @item #$@var{obj}:@var{output}
4805 @itemx (ungexp @var{obj} @var{output})
4806 This is like the form above, but referring explicitly to the
4807 @var{output} of @var{obj}---this is useful when @var{obj} produces
4808 multiple outputs (@pxref{Packages with Multiple Outputs}).
4811 @itemx #+@var{obj}:output
4812 @itemx (ungexp-native @var{obj})
4813 @itemx (ungexp-native @var{obj} @var{output})
4814 Same as @code{ungexp}, but produces a reference to the @emph{native}
4815 build of @var{obj} when used in a cross compilation context.
4817 @item #$output[:@var{output}]
4818 @itemx (ungexp output [@var{output}])
4819 Insert a reference to derivation output @var{output}, or to the main
4820 output when @var{output} is omitted.
4822 This only makes sense for gexps passed to @code{gexp->derivation}.
4825 @itemx (ungexp-splicing @var{lst})
4826 Like the above, but splices the contents of @var{lst} inside the
4830 @itemx (ungexp-native-splicing @var{lst})
4831 Like the above, but refers to native builds of the objects listed in
4836 G-expressions created by @code{gexp} or @code{#~} are run-time objects
4837 of the @code{gexp?} type (see below.)
4840 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
4841 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
4842 in their execution environment.
4844 Each item in @var{modules} can be the name of a module, such as
4845 @code{(guix build utils)}, or it can be a module name, followed by an
4846 arrow, followed by a file-like object:
4849 `((guix build utils)
4851 ((guix config) => ,(scheme-file "config.scm"
4852 #~(define-module @dots{}))))
4856 In the example above, the first two modules are taken from the search
4857 path, and the last one is created from the given file-like object.
4859 This form has @emph{lexical} scope: it has an effect on the gexps
4860 directly defined in @var{body}@dots{}, but not on those defined, say, in
4861 procedures called from @var{body}@dots{}.
4864 @deffn {Scheme Procedure} gexp? @var{obj}
4865 Return @code{#t} if @var{obj} is a G-expression.
4868 G-expressions are meant to be written to disk, either as code building
4869 some derivation, or as plain files in the store. The monadic procedures
4870 below allow you to do that (@pxref{The Store Monad}, for more
4871 information about monads.)
4873 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
4874 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
4875 [#:hash #f] [#:hash-algo #f] @
4876 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
4877 [#:module-path @var{%load-path}] @
4878 [#:references-graphs #f] [#:allowed-references #f] @
4879 [#:disallowed-references #f] @
4880 [#:leaked-env-vars #f] @
4881 [#:script-name (string-append @var{name} "-builder")] @
4882 [#:deprecation-warnings #f] @
4883 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
4884 Return a derivation @var{name} that runs @var{exp} (a gexp) with
4885 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
4886 stored in a file called @var{script-name}. When @var{target} is true,
4887 it is used as the cross-compilation target triplet for packages referred
4890 @var{modules} is deprecated in favor of @code{with-imported-modules}.
4892 make @var{modules} available in the evaluation context of @var{exp};
4893 @var{modules} is a list of names of Guile modules searched in
4894 @var{module-path} to be copied in the store, compiled, and made available in
4895 the load path during the execution of @var{exp}---e.g., @code{((guix
4896 build utils) (guix build gnu-build-system))}.
4898 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
4901 When @var{references-graphs} is true, it must be a list of tuples of one of the
4905 (@var{file-name} @var{package})
4906 (@var{file-name} @var{package} @var{output})
4907 (@var{file-name} @var{derivation})
4908 (@var{file-name} @var{derivation} @var{output})
4909 (@var{file-name} @var{store-item})
4912 The right-hand-side of each element of @var{references-graphs} is automatically made
4913 an input of the build process of @var{exp}. In the build environment, each
4914 @var{file-name} contains the reference graph of the corresponding item, in a simple
4917 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
4918 In the latter case, the list denotes store items that the result is allowed to
4919 refer to. Any reference to another store item will lead to a build error.
4920 Similarly for @var{disallowed-references}, which can list items that must not be
4921 referenced by the outputs.
4923 @var{deprecation-warnings} determines whether to show deprecation warnings while
4924 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
4926 The other arguments are as for @code{derivation} (@pxref{Derivations}).
4929 @cindex file-like objects
4930 The @code{local-file}, @code{plain-file}, @code{computed-file},
4931 @code{program-file}, and @code{scheme-file} procedures below return
4932 @dfn{file-like objects}. That is, when unquoted in a G-expression,
4933 these objects lead to a file in the store. Consider this G-expression:
4936 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
4937 #$(local-file "/tmp/my-nscd.conf"))
4940 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
4941 to the store. Once expanded, for instance @i{via}
4942 @code{gexp->derivation}, the G-expression refers to that copy under
4943 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
4944 does not have any effect on what the G-expression does.
4945 @code{plain-file} can be used similarly; it differs in that the file
4946 content is directly passed as a string.
4948 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
4949 [#:recursive? #f] [#:select? (const #t)]
4950 Return an object representing local file @var{file} to add to the store; this
4951 object can be used in a gexp. If @var{file} is a relative file name, it is looked
4952 up relative to the source file where this form appears. @var{file} will be added to
4953 the store under @var{name}--by default the base name of @var{file}.
4955 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
4956 designates a flat file and @var{recursive?} is true, its contents are added, and its
4957 permission bits are kept.
4959 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
4960 @var{stat})} for each directory entry, where @var{file} is the entry's
4961 absolute file name and @var{stat} is the result of @code{lstat}; exclude
4962 entries for which @var{select?} does not return true.
4964 This is the declarative counterpart of the @code{interned-file} monadic
4965 procedure (@pxref{The Store Monad, @code{interned-file}}).
4968 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
4969 Return an object representing a text file called @var{name} with the given
4970 @var{content} (a string) to be added to the store.
4972 This is the declarative counterpart of @code{text-file}.
4975 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
4976 [#:options '(#:local-build? #t)]
4977 Return an object representing the store item @var{name}, a file or
4978 directory computed by @var{gexp}. @var{options}
4979 is a list of additional arguments to pass to @code{gexp->derivation}.
4981 This is the declarative counterpart of @code{gexp->derivation}.
4984 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp}
4985 Return an executable script @var{name} that runs @var{exp} using
4986 @var{guile}, with @var{exp}'s imported modules in its search path.
4988 The example below builds a script that simply invokes the @command{ls}
4992 (use-modules (guix gexp) (gnu packages base))
4994 (gexp->script "list-files"
4995 #~(execl #$(file-append coreutils "/bin/ls")
4999 When ``running'' it through the store (@pxref{The Store Monad,
5000 @code{run-with-store}}), we obtain a derivation that produces an
5001 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
5004 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
5006 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
5010 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
5012 Return an object representing the executable store item @var{name} that
5013 runs @var{gexp}. @var{guile} is the Guile package used to execute that
5016 This is the declarative counterpart of @code{gexp->script}.
5019 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
5020 [#:set-load-path? #t]
5021 Return a derivation that builds a file @var{name} containing @var{exp}.
5022 When @var{set-load-path?} is true, emit code in the resulting file to
5023 set @code{%load-path} and @code{%load-compiled-path} to honor
5024 @var{exp}'s imported modules.
5026 The resulting file holds references to all the dependencies of @var{exp}
5027 or a subset thereof.
5030 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp}
5031 Return an object representing the Scheme file @var{name} that contains
5034 This is the declarative counterpart of @code{gexp->file}.
5037 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
5038 Return as a monadic value a derivation that builds a text file
5039 containing all of @var{text}. @var{text} may list, in addition to
5040 strings, objects of any type that can be used in a gexp: packages,
5041 derivations, local file objects, etc. The resulting store file holds
5042 references to all these.
5044 This variant should be preferred over @code{text-file} anytime the file
5045 to create will reference items from the store. This is typically the
5046 case when building a configuration file that embeds store file names,
5050 (define (profile.sh)
5051 ;; Return the name of a shell script in the store that
5052 ;; initializes the 'PATH' environment variable.
5053 (text-file* "profile.sh"
5054 "export PATH=" coreutils "/bin:"
5055 grep "/bin:" sed "/bin\n"))
5058 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
5059 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
5060 preventing them from being garbage-collected during its lifetime.
5063 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
5064 Return an object representing store file @var{name} containing
5065 @var{text}. @var{text} is a sequence of strings and file-like objects,
5069 (mixed-text-file "profile"
5070 "export PATH=" coreutils "/bin:" grep "/bin")
5073 This is the declarative counterpart of @code{text-file*}.
5076 @deffn {Scheme Procedure} file-union @var{name} @var{files}
5077 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
5078 Each item in @var{files} must be a two-element list where the first element is the
5079 file name to use in the new directory, and the second element is a gexp
5080 denoting the target file. Here's an example:
5084 `(("hosts" ,(plain-file "hosts"
5085 "127.0.0.1 localhost"))
5086 ("bashrc" ,(plain-file "bashrc"
5087 "alias ls='ls --color'"))))
5090 This yields an @code{etc} directory containing these two files.
5093 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
5094 Return a directory that is the union of @var{things}, where @var{things} is a list of
5095 file-like objects denoting directories. For example:
5098 (directory-union "guile+emacs" (list guile emacs))
5101 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
5104 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
5105 Return a file-like object that expands to the concatenation of @var{obj}
5106 and @var{suffix}, where @var{obj} is a lowerable object and each
5107 @var{suffix} is a string.
5109 As an example, consider this gexp:
5112 (gexp->script "run-uname"
5113 #~(system* #$(file-append coreutils
5117 The same effect could be achieved with:
5120 (gexp->script "run-uname"
5121 #~(system* (string-append #$coreutils
5125 There is one difference though: in the @code{file-append} case, the
5126 resulting script contains the absolute file name as a string, whereas in
5127 the second case, the resulting script contains a @code{(string-append
5128 @dots{})} expression to construct the file name @emph{at run time}.
5132 Of course, in addition to gexps embedded in ``host'' code, there are
5133 also modules containing build tools. To make it clear that they are
5134 meant to be used in the build stratum, these modules are kept in the
5135 @code{(guix build @dots{})} name space.
5137 @cindex lowering, of high-level objects in gexps
5138 Internally, high-level objects are @dfn{lowered}, using their compiler,
5139 to either derivations or store items. For instance, lowering a package
5140 yields a derivation, and lowering a @code{plain-file} yields a store
5141 item. This is achieved using the @code{lower-object} monadic procedure.
5143 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
5145 Return as a value in @var{%store-monad} the derivation or store item
5146 corresponding to @var{obj} for @var{system}, cross-compiling for
5147 @var{target} if @var{target} is true. @var{obj} must be an object that
5148 has an associated gexp compiler, such as a @code{<package>}.
5152 @c *********************************************************************
5156 This section describes Guix command-line utilities. Some of them are
5157 primarily targeted at developers and users who write new package
5158 definitions, while others are more generally useful. They complement
5159 the Scheme programming interface of Guix in a convenient way.
5162 * Invoking guix build:: Building packages from the command line.
5163 * Invoking guix edit:: Editing package definitions.
5164 * Invoking guix download:: Downloading a file and printing its hash.
5165 * Invoking guix hash:: Computing the cryptographic hash of a file.
5166 * Invoking guix import:: Importing package definitions.
5167 * Invoking guix refresh:: Updating package definitions.
5168 * Invoking guix lint:: Finding errors in package definitions.
5169 * Invoking guix size:: Profiling disk usage.
5170 * Invoking guix graph:: Visualizing the graph of packages.
5171 * Invoking guix environment:: Setting up development environments.
5172 * Invoking guix publish:: Sharing substitutes.
5173 * Invoking guix challenge:: Challenging substitute servers.
5174 * Invoking guix copy:: Copying to and from a remote store.
5175 * Invoking guix container:: Process isolation.
5176 * Invoking guix weather:: Assessing substitute availability.
5179 @node Invoking guix build
5180 @section Invoking @command{guix build}
5182 @cindex package building
5183 @cindex @command{guix build}
5184 The @command{guix build} command builds packages or derivations and
5185 their dependencies, and prints the resulting store paths. Note that it
5186 does not modify the user's profile---this is the job of the
5187 @command{guix package} command (@pxref{Invoking guix package}). Thus,
5188 it is mainly useful for distribution developers.
5190 The general syntax is:
5193 guix build @var{options} @var{package-or-derivation}@dots{}
5196 As an example, the following command builds the latest versions of Emacs
5197 and of Guile, displays their build logs, and finally displays the
5198 resulting directories:
5201 guix build emacs guile
5204 Similarly, the following command builds all the available packages:
5207 guix build --quiet --keep-going \
5208 `guix package -A | cut -f1,2 --output-delimiter=@@`
5211 @var{package-or-derivation} may be either the name of a package found in
5212 the software distribution such as @code{coreutils} or
5213 @code{coreutils@@8.20}, or a derivation such as
5214 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
5215 package with the corresponding name (and optionally version) is searched
5216 for among the GNU distribution modules (@pxref{Package Modules}).
5218 Alternatively, the @code{--expression} option may be used to specify a
5219 Scheme expression that evaluates to a package; this is useful when
5220 disambiguating among several same-named packages or package variants is
5223 There may be zero or more @var{options}. The available options are
5224 described in the subsections below.
5227 * Common Build Options:: Build options for most commands.
5228 * Package Transformation Options:: Creating variants of packages.
5229 * Additional Build Options:: Options specific to 'guix build'.
5230 * Debugging Build Failures:: Real life packaging experience.
5233 @node Common Build Options
5234 @subsection Common Build Options
5236 A number of options that control the build process are common to
5237 @command{guix build} and other commands that can spawn builds, such as
5238 @command{guix package} or @command{guix archive}. These are the
5243 @item --load-path=@var{directory}
5244 @itemx -L @var{directory}
5245 Add @var{directory} to the front of the package module search path
5246 (@pxref{Package Modules}).
5248 This allows users to define their own packages and make them visible to
5249 the command-line tools.
5253 Keep the build tree of failed builds. Thus, if a build fails, its build
5254 tree is kept under @file{/tmp}, in a directory whose name is shown at
5255 the end of the build log. This is useful when debugging build issues.
5256 @xref{Debugging Build Failures}, for tips and tricks on how to debug
5261 Keep going when some of the derivations fail to build; return only once
5262 all the builds have either completed or failed.
5264 The default behavior is to stop as soon as one of the specified
5265 derivations has failed.
5269 Do not build the derivations.
5271 @anchor{fallback-option}
5273 When substituting a pre-built binary fails, fall back to building
5274 packages locally (@pxref{Substitution Failure}).
5276 @item --substitute-urls=@var{urls}
5277 @anchor{client-substitute-urls}
5278 Consider @var{urls} the whitespace-separated list of substitute source
5279 URLs, overriding the default list of URLs of @command{guix-daemon}
5280 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
5282 This means that substitutes may be downloaded from @var{urls}, provided
5283 they are signed by a key authorized by the system administrator
5284 (@pxref{Substitutes}).
5286 When @var{urls} is the empty string, substitutes are effectively
5289 @item --no-substitutes
5290 Do not use substitutes for build products. That is, always build things
5291 locally instead of allowing downloads of pre-built binaries
5292 (@pxref{Substitutes}).
5295 Do not ``graft'' packages. In practice, this means that package updates
5296 available as grafts are not applied. @xref{Security Updates}, for more
5297 information on grafts.
5299 @item --rounds=@var{n}
5300 Build each derivation @var{n} times in a row, and raise an error if
5301 consecutive build results are not bit-for-bit identical.
5303 This is a useful way to detect non-deterministic builds processes.
5304 Non-deterministic build processes are a problem because they make it
5305 practically impossible for users to @emph{verify} whether third-party
5306 binaries are genuine. @xref{Invoking guix challenge}, for more.
5308 Note that, currently, the differing build results are not kept around,
5309 so you will have to manually investigate in case of an error---e.g., by
5310 stashing one of the build results with @code{guix archive --export}
5311 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
5314 @item --no-build-hook
5315 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
5316 (@pxref{Daemon Offload Setup}). That is, always build things locally
5317 instead of offloading builds to remote machines.
5319 @item --max-silent-time=@var{seconds}
5320 When the build or substitution process remains silent for more than
5321 @var{seconds}, terminate it and report a build failure.
5323 By default, the daemon's setting is honored (@pxref{Invoking
5324 guix-daemon, @code{--max-silent-time}}).
5326 @item --timeout=@var{seconds}
5327 Likewise, when the build or substitution process lasts for more than
5328 @var{seconds}, terminate it and report a build failure.
5330 By default, the daemon's setting is honored (@pxref{Invoking
5331 guix-daemon, @code{--timeout}}).
5333 @item --verbosity=@var{level}
5334 Use the given verbosity level. @var{level} must be an integer between 0
5335 and 5; higher means more verbose output. Setting a level of 4 or more
5336 may be helpful when debugging setup issues with the build daemon.
5338 @item --cores=@var{n}
5340 Allow the use of up to @var{n} CPU cores for the build. The special
5341 value @code{0} means to use as many CPU cores as available.
5343 @item --max-jobs=@var{n}
5345 Allow at most @var{n} build jobs in parallel. @xref{Invoking
5346 guix-daemon, @code{--max-jobs}}, for details about this option and the
5347 equivalent @command{guix-daemon} option.
5351 Behind the scenes, @command{guix build} is essentially an interface to
5352 the @code{package-derivation} procedure of the @code{(guix packages)}
5353 module, and to the @code{build-derivations} procedure of the @code{(guix
5354 derivations)} module.
5356 In addition to options explicitly passed on the command line,
5357 @command{guix build} and other @command{guix} commands that support
5358 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
5360 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
5361 Users can define this variable to a list of command line options that
5362 will automatically be used by @command{guix build} and other
5363 @command{guix} commands that can perform builds, as in the example
5367 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
5370 These options are parsed independently, and the result is appended to
5371 the parsed command-line options.
5375 @node Package Transformation Options
5376 @subsection Package Transformation Options
5378 @cindex package variants
5379 Another set of command-line options supported by @command{guix build}
5380 and also @command{guix package} are @dfn{package transformation
5381 options}. These are options that make it possible to define @dfn{package
5382 variants}---for instance, packages built from different source code.
5383 This is a convenient way to create customized packages on the fly
5384 without having to type in the definitions of package variants
5385 (@pxref{Defining Packages}).
5389 @item --with-source=@var{source}
5390 Use @var{source} as the source of the corresponding package.
5391 @var{source} must be a file name or a URL, as for @command{guix
5392 download} (@pxref{Invoking guix download}).
5394 The ``corresponding package'' is taken to be the one specified on the
5395 command line the name of which matches the base of @var{source}---e.g.,
5396 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
5397 package is @code{guile}. Likewise, the version string is inferred from
5398 @var{source}; in the previous example, it is @code{2.0.10}.
5400 This option allows users to try out versions of packages other than the
5401 one provided by the distribution. The example below downloads
5402 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
5403 the @code{ed} package:
5406 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
5409 As a developer, @code{--with-source} makes it easy to test release
5413 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
5416 @dots{} or to build from a checkout in a pristine environment:
5419 $ git clone git://git.sv.gnu.org/guix.git
5420 $ guix build guix --with-source=./guix
5423 @item --with-input=@var{package}=@var{replacement}
5424 Replace dependency on @var{package} by a dependency on
5425 @var{replacement}. @var{package} must be a package name, and
5426 @var{replacement} must be a package specification such as @code{guile}
5427 or @code{guile@@1.8}.
5429 For instance, the following command builds Guix, but replaces its
5430 dependency on the current stable version of Guile with a dependency on
5431 the legacy version of Guile, @code{guile@@2.0}:
5434 guix build --with-input=guile=guile@@2.0 guix
5437 This is a recursive, deep replacement. So in this example, both
5438 @code{guix} and its dependency @code{guile-json} (which also depends on
5439 @code{guile}) get rebuilt against @code{guile@@2.0}.
5441 This is implemented using the @code{package-input-rewriting} Scheme
5442 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
5444 @item --with-graft=@var{package}=@var{replacement}
5445 This is similar to @code{--with-input} but with an important difference:
5446 instead of rebuilding the whole dependency chain, @var{replacement} is
5447 built and then @dfn{grafted} onto the binaries that were initially
5448 referring to @var{package}. @xref{Security Updates}, for more
5449 information on grafts.
5451 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
5452 and all its dependencies, replacing references to the version of GnuTLS
5453 they currently refer to:
5456 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
5459 This has the advantage of being much faster than rebuilding everything.
5460 But there is a caveat: it works if and only if @var{package} and
5461 @var{replacement} are strictly compatible---for example, if they provide
5462 a library, the application binary interface (ABI) of those libraries
5463 must be compatible. If @var{replacement} is somehow incompatible with
5464 @var{package}, then the resulting package may be unusable. Use with
5469 @node Additional Build Options
5470 @subsection Additional Build Options
5472 The command-line options presented below are specific to @command{guix
5479 Build quietly, without displaying the build log. Upon completion, the
5480 build log is kept in @file{/var} (or similar) and can always be
5481 retrieved using the @option{--log-file} option.
5483 @item --file=@var{file}
5484 @itemx -f @var{file}
5486 Build the package or derivation that the code within @var{file}
5489 As an example, @var{file} might contain a package definition like this
5490 (@pxref{Defining Packages}):
5493 @verbatiminclude package-hello.scm
5496 @item --expression=@var{expr}
5497 @itemx -e @var{expr}
5498 Build the package or derivation @var{expr} evaluates to.
5500 For example, @var{expr} may be @code{(@@ (gnu packages guile)
5501 guile-1.8)}, which unambiguously designates this specific variant of
5502 version 1.8 of Guile.
5504 Alternatively, @var{expr} may be a G-expression, in which case it is used
5505 as a build program passed to @code{gexp->derivation}
5506 (@pxref{G-Expressions}).
5508 Lastly, @var{expr} may refer to a zero-argument monadic procedure
5509 (@pxref{The Store Monad}). The procedure must return a derivation as a
5510 monadic value, which is then passed through @code{run-with-store}.
5514 Build the source derivations of the packages, rather than the packages
5517 For instance, @code{guix build -S gcc} returns something like
5518 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
5521 The returned source tarball is the result of applying any patches and
5522 code snippets specified in the package @code{origin} (@pxref{Defining
5526 Fetch and return the source of @var{package-or-derivation} and all their
5527 dependencies, recursively. This is a handy way to obtain a local copy
5528 of all the source code needed to build @var{packages}, allowing you to
5529 eventually build them even without network access. It is an extension
5530 of the @code{--source} option and can accept one of the following
5531 optional argument values:
5535 This value causes the @code{--sources} option to behave in the same way
5536 as the @code{--source} option.
5539 Build the source derivations of all packages, including any source that
5540 might be listed as @code{inputs}. This is the default value.
5543 $ guix build --sources tzdata
5544 The following derivations will be built:
5545 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
5546 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
5550 Build the source derivations of all packages, as well of all transitive
5551 inputs to the packages. This can be used e.g. to
5552 prefetch package source for later offline building.
5555 $ guix build --sources=transitive tzdata
5556 The following derivations will be built:
5557 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
5558 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
5559 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
5560 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
5561 /gnu/store/@dots{}-make-4.1.tar.xz.drv
5562 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
5568 @item --system=@var{system}
5569 @itemx -s @var{system}
5570 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5571 the system type of the build host.
5573 An example use of this is on Linux-based systems, which can emulate
5574 different personalities. For instance, passing
5575 @code{--system=i686-linux} on an @code{x86_64-linux} system allows users
5576 to build packages in a complete 32-bit environment.
5578 @item --target=@var{triplet}
5579 @cindex cross-compilation
5580 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5581 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
5582 configuration triplets,, autoconf, Autoconf}).
5584 @anchor{build-check}
5586 @cindex determinism, checking
5587 @cindex reproducibility, checking
5588 Rebuild @var{package-or-derivation}, which are already available in the
5589 store, and raise an error if the build results are not bit-for-bit
5592 This mechanism allows you to check whether previously installed
5593 substitutes are genuine (@pxref{Substitutes}), or whether the build result
5594 of a package is deterministic. @xref{Invoking guix challenge}, for more
5595 background information and tools.
5597 When used in conjunction with @option{--keep-failed}, the differing
5598 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
5599 This makes it easy to look for differences between the two results.
5602 @cindex repairing store items
5603 @cindex corruption, recovering from
5604 Attempt to repair the specified store items, if they are corrupt, by
5605 re-downloading or rebuilding them.
5607 This operation is not atomic and thus restricted to @code{root}.
5611 Return the derivation paths, not the output paths, of the given
5614 @item --root=@var{file}
5615 @itemx -r @var{file}
5616 @cindex GC roots, adding
5617 @cindex garbage collector roots, adding
5618 Make @var{file} a symlink to the result, and register it as a garbage
5621 Consequently, the results of this @command{guix build} invocation are
5622 protected from garbage collection until @var{file} is removed. When
5623 that option is omitted, build results are eligible for garbage
5624 collection as soon as the build completes. @xref{Invoking guix gc}, for
5628 Return the build log file names or URLs for the given
5629 @var{package-or-derivation}, or raise an error if build logs are
5632 This works regardless of how packages or derivations are specified. For
5633 instance, the following invocations are equivalent:
5636 guix build --log-file `guix build -d guile`
5637 guix build --log-file `guix build guile`
5638 guix build --log-file guile
5639 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
5642 If a log is unavailable locally, and unless @code{--no-substitutes} is
5643 passed, the command looks for a corresponding log on one of the
5644 substitute servers (as specified with @code{--substitute-urls}.)
5646 So for instance, imagine you want to see the build log of GDB on MIPS,
5647 but you are actually on an @code{x86_64} machine:
5650 $ guix build --log-file gdb -s mips64el-linux
5651 https://hydra.gnu.org/log/@dots{}-gdb-7.10
5654 You can freely access a huge library of build logs!
5657 @node Debugging Build Failures
5658 @subsection Debugging Build Failures
5660 @cindex build failures, debugging
5661 When defining a new package (@pxref{Defining Packages}), you will
5662 probably find yourself spending some time debugging and tweaking the
5663 build until it succeeds. To do that, you need to operate the build
5664 commands yourself in an environment as close as possible to the one the
5667 To that end, the first thing to do is to use the @option{--keep-failed}
5668 or @option{-K} option of @command{guix build}, which will keep the
5669 failed build tree in @file{/tmp} or whatever directory you specified as
5670 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
5672 From there on, you can @command{cd} to the failed build tree and source
5673 the @file{environment-variables} file, which contains all the
5674 environment variable definitions that were in place when the build
5675 failed. So let's say you're debugging a build failure in package
5676 @code{foo}; a typical session would look like this:
5680 @dots{} @i{build fails}
5681 $ cd /tmp/guix-build-foo.drv-0
5682 $ source ./environment-variables
5686 Now, you can invoke commands as if you were the daemon (almost) and
5687 troubleshoot your build process.
5689 Sometimes it happens that, for example, a package's tests pass when you
5690 run them manually but they fail when the daemon runs them. This can
5691 happen because the daemon runs builds in containers where, unlike in our
5692 environment above, network access is missing, @file{/bin/sh} does not
5693 exist, etc. (@pxref{Build Environment Setup}).
5695 In such cases, you may need to run inspect the build process from within
5696 a container similar to the one the build daemon creates:
5701 $ cd /tmp/guix-build-foo.drv-0
5702 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
5703 [env]# source ./environment-variables
5707 Here, @command{guix environment -C} creates a container and spawns a new
5708 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
5709 strace gdb} part adds the @command{strace} and @command{gdb} commands to
5710 the container, which would may find handy while debugging. The
5711 @option{--no-grafts} option makes sure we get the exact same
5712 environment, with ungrafted packages (@pxref{Security Updates}, for more
5715 To get closer to a container like that used by the build daemon, we can
5716 remove @file{/bin/sh}:
5722 (Don't worry, this is harmless: this is all happening in the throw-away
5723 container created by @command{guix environment}.)
5725 The @command{strace} command is probably not in the search path, but we
5729 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
5732 In this way, not only you will have reproduced the environment variables
5733 the daemon uses, you will also be running the build process in a container
5734 similar to the one the daemon uses.
5737 @node Invoking guix edit
5738 @section Invoking @command{guix edit}
5740 @cindex @command{guix edit}
5741 @cindex package definition, editing
5742 So many packages, so many source files! The @command{guix edit} command
5743 facilitates the life of users and packagers by pointing their editor at
5744 the source file containing the definition of the specified packages.
5748 guix edit gcc@@4.9 vim
5752 launches the program specified in the @code{VISUAL} or in the
5753 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
5756 If you are using a Guix Git checkout (@pxref{Building from Git}), or
5757 have created your own packages on @code{GUIX_PACKAGE_PATH}
5758 (@pxref{Defining Packages}), you will be able to edit the package
5759 recipes. Otherwise, you will be able to examine the read-only recipes
5760 for packages currently in the store.
5763 @node Invoking guix download
5764 @section Invoking @command{guix download}
5766 @cindex @command{guix download}
5767 @cindex downloading package sources
5768 When writing a package definition, developers typically need to download
5769 a source tarball, compute its SHA256 hash, and write that
5770 hash in the package definition (@pxref{Defining Packages}). The
5771 @command{guix download} tool helps with this task: it downloads a file
5772 from the given URI, adds it to the store, and prints both its file name
5773 in the store and its SHA256 hash.
5775 The fact that the downloaded file is added to the store saves bandwidth:
5776 when the developer eventually tries to build the newly defined package
5777 with @command{guix build}, the source tarball will not have to be
5778 downloaded again because it is already in the store. It is also a
5779 convenient way to temporarily stash files, which may be deleted
5780 eventually (@pxref{Invoking guix gc}).
5782 The @command{guix download} command supports the same URIs as used in
5783 package definitions. In particular, it supports @code{mirror://} URIs.
5784 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
5785 Guile bindings for GnuTLS are available in the user's environment; when
5786 they are not available, an error is raised. @xref{Guile Preparations,
5787 how to install the GnuTLS bindings for Guile,, gnutls-guile,
5788 GnuTLS-Guile}, for more information.
5790 @command{guix download} verifies HTTPS server certificates by loading
5791 the certificates of X.509 authorities from the directory pointed to by
5792 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
5793 Certificates}), unless @option{--no-check-certificate} is used.
5795 The following options are available:
5798 @item --format=@var{fmt}
5800 Write the hash in the format specified by @var{fmt}. For more
5801 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
5803 @item --no-check-certificate
5804 Do not validate the X.509 certificates of HTTPS servers.
5806 When using this option, you have @emph{absolutely no guarantee} that you
5807 are communicating with the authentic server responsible for the given
5808 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
5810 @item --output=@var{file}
5811 @itemx -o @var{file}
5812 Save the downloaded file to @var{file} instead of adding it to the
5816 @node Invoking guix hash
5817 @section Invoking @command{guix hash}
5819 @cindex @command{guix hash}
5820 The @command{guix hash} command computes the SHA256 hash of a file.
5821 It is primarily a convenience tool for anyone contributing to the
5822 distribution: it computes the cryptographic hash of a file, which can be
5823 used in the definition of a package (@pxref{Defining Packages}).
5825 The general syntax is:
5828 guix hash @var{option} @var{file}
5831 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
5832 hash of data read from standard input. @command{guix hash} has the
5837 @item --format=@var{fmt}
5839 Write the hash in the format specified by @var{fmt}.
5841 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
5842 (@code{hex} and @code{hexadecimal} can be used as well).
5844 If the @option{--format} option is not specified, @command{guix hash}
5845 will output the hash in @code{nix-base32}. This representation is used
5846 in the definitions of packages.
5850 Compute the hash on @var{file} recursively.
5852 In this case, the hash is computed on an archive containing @var{file},
5853 including its children if it is a directory. Some of the metadata of
5854 @var{file} is part of the archive; for instance, when @var{file} is a
5855 regular file, the hash is different depending on whether @var{file} is
5856 executable or not. Metadata such as time stamps has no impact on the
5857 hash (@pxref{Invoking guix archive}).
5858 @c FIXME: Replace xref above with xref to an ``Archive'' section when
5863 When combined with @option{--recursive}, exclude version control system
5864 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
5867 As an example, here is how you would compute the hash of a Git checkout,
5868 which is useful when using the @code{git-fetch} method (@pxref{origin
5872 $ git clone http://example.org/foo.git
5878 @node Invoking guix import
5879 @section Invoking @command{guix import}
5881 @cindex importing packages
5882 @cindex package import
5883 @cindex package conversion
5884 @cindex Invoking @command{guix import}
5885 The @command{guix import} command is useful for people who would like to
5886 add a package to the distribution with as little work as
5887 possible---a legitimate demand. The command knows of a few
5888 repositories from which it can ``import'' package metadata. The result
5889 is a package definition, or a template thereof, in the format we know
5890 (@pxref{Defining Packages}).
5892 The general syntax is:
5895 guix import @var{importer} @var{options}@dots{}
5898 @var{importer} specifies the source from which to import package
5899 metadata, and @var{options} specifies a package identifier and other
5900 options specific to @var{importer}. Currently, the available
5905 Import metadata for the given GNU package. This provides a template
5906 for the latest version of that GNU package, including the hash of its
5907 source tarball, and its canonical synopsis and description.
5909 Additional information such as the package dependencies and its
5910 license needs to be figured out manually.
5912 For example, the following command returns a package definition for
5916 guix import gnu hello
5919 Specific command-line options are:
5922 @item --key-download=@var{policy}
5923 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
5924 keys when verifying the package signature. @xref{Invoking guix
5925 refresh, @code{--key-download}}.
5930 Import metadata from the @uref{https://pypi.python.org/, Python Package
5931 Index}@footnote{This functionality requires Guile-JSON to be installed.
5932 @xref{Requirements}.}. Information is taken from the JSON-formatted
5933 description available at @code{pypi.python.org} and usually includes all
5934 the relevant information, including package dependencies. For maximum
5935 efficiency, it is recommended to install the @command{unzip} utility, so
5936 that the importer can unzip Python wheels and gather data from them.
5938 The command below imports metadata for the @code{itsdangerous} Python
5942 guix import pypi itsdangerous
5947 Import metadata from @uref{https://rubygems.org/,
5948 RubyGems}@footnote{This functionality requires Guile-JSON to be
5949 installed. @xref{Requirements}.}. Information is taken from the
5950 JSON-formatted description available at @code{rubygems.org} and includes
5951 most relevant information, including runtime dependencies. There are
5952 some caveats, however. The metadata doesn't distinguish between
5953 synopses and descriptions, so the same string is used for both fields.
5954 Additionally, the details of non-Ruby dependencies required to build
5955 native extensions is unavailable and left as an exercise to the
5958 The command below imports metadata for the @code{rails} Ruby package:
5961 guix import gem rails
5966 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}@footnote{This
5967 functionality requires Guile-JSON to be installed.
5968 @xref{Requirements}.}.
5969 Information is taken from the JSON-formatted metadata provided through
5970 @uref{https://api.metacpan.org/, MetaCPAN's API} and includes most
5971 relevant information, such as module dependencies. License information
5972 should be checked closely. If Perl is available in the store, then the
5973 @code{corelist} utility will be used to filter core modules out of the
5974 list of dependencies.
5976 The command command below imports metadata for the @code{Acme::Boolean}
5980 guix import cpan Acme::Boolean
5985 @cindex Bioconductor
5986 Import metadata from @uref{http://cran.r-project.org/, CRAN}, the
5987 central repository for the @uref{http://r-project.org, GNU@tie{}R
5988 statistical and graphical environment}.
5990 Information is extracted from the @code{DESCRIPTION} file of the package.
5992 The command command below imports metadata for the @code{Cairo}
5996 guix import cran Cairo
5999 When @code{--recursive} is added, the importer will traverse the
6000 dependency graph of the given upstream package recursively and generate
6001 package expressions for all those packages that are not yet in Guix.
6003 When @code{--archive=bioconductor} is added, metadata is imported from
6004 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
6005 packages for for the analysis and comprehension of high-throughput
6006 genomic data in bioinformatics.
6008 Information is extracted from the @code{DESCRIPTION} file of a package
6009 published on the web interface of the Bioconductor SVN repository.
6011 The command below imports metadata for the @code{GenomicRanges}
6015 guix import cran --archive=bioconductor GenomicRanges
6021 Import metadata from @uref{http://www.ctan.org/, CTAN}, the
6022 comprehensive TeX archive network for TeX packages that are part of the
6023 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
6025 Information about the package is obtained through the XML API provided
6026 by CTAN, while the source code is downloaded from the SVN repository of
6027 the Tex Live project. This is done because the CTAN does not keep
6030 The command command below imports metadata for the @code{fontspec}
6034 guix import texlive fontspec
6037 When @code{--archive=DIRECTORY} is added, the source code is downloaded
6038 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
6039 tree in the TeX Live SVN repository, but from the specified sibling
6040 directory under the same root.
6042 The command below imports metadata for the @code{ifxetex} package from
6043 CTAN while fetching the sources from the directory
6044 @file{texmf/source/generic}:
6047 guix import texlive --archive=generic ifxetex
6051 @cindex JSON, import
6052 Import package metadata from a local JSON file@footnote{This
6053 functionality requires Guile-JSON to be installed.
6054 @xref{Requirements}.}. Consider the following example package
6055 definition in JSON format:
6061 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
6062 "build-system": "gnu",
6063 "home-page": "https://www.gnu.org/software/hello/",
6064 "synopsis": "Hello, GNU world: An example GNU package",
6065 "description": "GNU Hello prints a greeting.",
6066 "license": "GPL-3.0+",
6067 "native-inputs": ["gcc@@6"]
6071 The field names are the same as for the @code{<package>} record
6072 (@xref{Defining Packages}). References to other packages are provided
6073 as JSON lists of quoted package specification strings such as
6074 @code{guile} or @code{guile@@2.0}.
6076 The importer also supports a more explicit source definition using the
6077 common fields for @code{<origin>} records:
6083 "method": "url-fetch",
6084 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
6086 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
6093 The command below reads metadata from the JSON file @code{hello.json}
6094 and outputs a package expression:
6097 guix import json hello.json
6101 Import metadata from a local copy of the source of the
6102 @uref{http://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
6103 relies on the @command{nix-instantiate} command of
6104 @uref{http://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
6105 typically written in a mixture of Nix-language and Bash code. This
6106 command only imports the high-level package structure that is written in
6107 the Nix language. It normally includes all the basic fields of a
6110 When importing a GNU package, the synopsis and descriptions are replaced
6111 by their canonical upstream variant.
6113 Usually, you will first need to do:
6116 export NIX_REMOTE=daemon
6120 so that @command{nix-instantiate} does not try to open the Nix database.
6122 As an example, the command below imports the package definition of
6123 LibreOffice (more precisely, it imports the definition of the package
6124 bound to the @code{libreoffice} top-level attribute):
6127 guix import nix ~/path/to/nixpkgs libreoffice
6132 Import metadata from the Haskell community's central package archive
6133 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
6134 Cabal files and includes all the relevant information, including package
6137 Specific command-line options are:
6142 Read a Cabal file from standard input.
6143 @item --no-test-dependencies
6145 Do not include dependencies required only by the test suites.
6146 @item --cabal-environment=@var{alist}
6147 @itemx -e @var{alist}
6148 @var{alist} is a Scheme alist defining the environment in which the
6149 Cabal conditionals are evaluated. The accepted keys are: @code{os},
6150 @code{arch}, @code{impl} and a string representing the name of a flag.
6151 The value associated with a flag has to be either the symbol
6152 @code{true} or @code{false}. The value associated with other keys
6153 has to conform to the Cabal file format definition. The default value
6154 associated with the keys @code{os}, @code{arch} and @code{impl} is
6155 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
6158 The command below imports metadata for the latest version of the
6159 @code{HTTP} Haskell package without including test dependencies and
6160 specifying the value of the flag @samp{network-uri} as @code{false}:
6163 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
6166 A specific package version may optionally be specified by following the
6167 package name by an at-sign and a version number as in the following example:
6170 guix import hackage mtl@@2.1.3.1
6175 The @code{stackage} importer is a wrapper around the @code{hackage} one.
6176 It takes a package name, looks up the package version included in a
6177 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
6178 release and uses the @code{hackage} importer to retrieve its metadata.
6179 Note that it is up to you to select an LTS release compatible with the
6180 GHC compiler used by Guix.
6182 Specific command-line options are:
6185 @item --no-test-dependencies
6187 Do not include dependencies required only by the test suites.
6188 @item --lts-version=@var{version}
6189 @itemx -r @var{version}
6190 @var{version} is the desired LTS release version. If omitted the latest
6194 The command below imports metadata for the @code{HTTP} Haskell package
6195 included in the LTS Stackage release version 7.18:
6198 guix import stackage --lts-version=7.18 HTTP
6203 Import metadata from an Emacs Lisp Package Archive (ELPA) package
6204 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6206 Specific command-line options are:
6209 @item --archive=@var{repo}
6210 @itemx -a @var{repo}
6211 @var{repo} identifies the archive repository from which to retrieve the
6212 information. Currently the supported repositories and their identifiers
6216 @uref{http://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
6217 identifier. This is the default.
6219 Packages from @code{elpa.gnu.org} are signed with one of the keys
6220 contained in the GnuPG keyring at
6221 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
6222 @code{emacs} package (@pxref{Package Installation, ELPA package
6223 signatures,, emacs, The GNU Emacs Manual}).
6226 @uref{http://stable.melpa.org/packages, MELPA-Stable}, selected by the
6227 @code{melpa-stable} identifier.
6230 @uref{http://melpa.org/packages, MELPA}, selected by the @code{melpa}
6237 Import metadata from the crates.io Rust package repository
6238 @uref{https://crates.io, crates.io}.
6241 The structure of the @command{guix import} code is modular. It would be
6242 useful to have more importers for other package formats, and your help
6243 is welcome here (@pxref{Contributing}).
6245 @node Invoking guix refresh
6246 @section Invoking @command{guix refresh}
6248 @cindex @command {guix refresh}
6249 The primary audience of the @command{guix refresh} command is developers
6250 of the GNU software distribution. By default, it reports any packages
6251 provided by the distribution that are outdated compared to the latest
6252 upstream version, like this:
6256 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
6257 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
6260 Alternately, one can specify packages to consider, in which case a
6261 warning is emitted for packages that lack an updater:
6264 $ guix refresh coreutils guile guile-ssh
6265 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
6266 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
6269 @command{guix refresh} browses the upstream repository of each package and determines
6270 the highest version number of the releases therein. The command
6271 knows how to update specific types of packages: GNU packages, ELPA
6272 packages, etc.---see the documentation for @option{--type} below. There
6273 are many packages, though, for which it lacks a method to determine
6274 whether a new upstream release is available. However, the mechanism is
6275 extensible, so feel free to get in touch with us to add a new method!
6277 When passed @code{--update}, it modifies distribution source files to
6278 update the version numbers and source tarball hashes of those package
6279 recipes (@pxref{Defining Packages}). This is achieved by downloading
6280 each package's latest source tarball and its associated OpenPGP
6281 signature, authenticating the downloaded tarball against its signature
6282 using @command{gpg}, and finally computing its hash. When the public
6283 key used to sign the tarball is missing from the user's keyring, an
6284 attempt is made to automatically retrieve it from a public key server;
6285 when this is successful, the key is added to the user's keyring; otherwise,
6286 @command{guix refresh} reports an error.
6288 The following options are supported:
6292 @item --expression=@var{expr}
6293 @itemx -e @var{expr}
6294 Consider the package @var{expr} evaluates to.
6296 This is useful to precisely refer to a package, as in this example:
6299 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
6302 This command lists the dependents of the ``final'' libc (essentially all
6307 Update distribution source files (package recipes) in place. This is
6308 usually run from a checkout of the Guix source tree (@pxref{Running
6309 Guix Before It Is Installed}):
6312 $ ./pre-inst-env guix refresh -s non-core -u
6315 @xref{Defining Packages}, for more information on package definitions.
6317 @item --select=[@var{subset}]
6318 @itemx -s @var{subset}
6319 Select all the packages in @var{subset}, one of @code{core} or
6322 The @code{core} subset refers to all the packages at the core of the
6323 distribution---i.e., packages that are used to build ``everything
6324 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
6325 changing one of these packages in the distribution entails a rebuild of
6326 all the others. Thus, such updates are an inconvenience to users in
6327 terms of build time or bandwidth used to achieve the upgrade.
6329 The @code{non-core} subset refers to the remaining packages. It is
6330 typically useful in cases where an update of the core packages would be
6333 @item --manifest=@var{file}
6334 @itemx -m @var{file}
6335 Select all the packages from the manifest in @var{file}. This is useful to
6336 check if any packages of the user manifest can be updated.
6338 @item --type=@var{updater}
6339 @itemx -t @var{updater}
6340 Select only packages handled by @var{updater} (may be a comma-separated
6341 list of updaters). Currently, @var{updater} may be one of:
6345 the updater for GNU packages;
6347 the updater for GNOME packages;
6349 the updater for KDE packages;
6351 the updater for X.org packages;
6353 the updater for packages hosted on kernel.org;
6355 the updater for @uref{http://elpa.gnu.org/, ELPA} packages;
6357 the updater for @uref{http://cran.r-project.org/, CRAN} packages;
6359 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
6361 the updater for @uref{http://www.cpan.org/, CPAN} packages;
6363 the updater for @uref{https://pypi.python.org, PyPI} packages.
6365 the updater for @uref{https://rubygems.org, RubyGems} packages.
6367 the updater for @uref{https://github.com, GitHub} packages.
6369 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
6371 the updater for @uref{https://www.stackage.org, Stackage} packages.
6373 the updater for @uref{https://crates.io, Crates} packages.
6376 For instance, the following command only checks for updates of Emacs
6377 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
6380 $ guix refresh --type=elpa,cran
6381 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
6382 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
6387 In addition, @command{guix refresh} can be passed one or more package
6388 names, as in this example:
6391 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
6395 The command above specifically updates the @code{emacs} and
6396 @code{idutils} packages. The @code{--select} option would have no
6397 effect in this case.
6399 When considering whether to upgrade a package, it is sometimes
6400 convenient to know which packages would be affected by the upgrade and
6401 should be checked for compatibility. For this the following option may
6402 be used when passing @command{guix refresh} one or more package names:
6406 @item --list-updaters
6408 List available updaters and exit (see @option{--type} above.)
6410 For each updater, display the fraction of packages it covers; at the
6411 end, display the fraction of packages covered by all these updaters.
6413 @item --list-dependent
6415 List top-level dependent packages that would need to be rebuilt as a
6416 result of upgrading one or more packages.
6418 @xref{Invoking guix graph, the @code{reverse-package} type of
6419 @command{guix graph}}, for information on how to visualize the list of
6420 dependents of a package.
6424 Be aware that the @code{--list-dependent} option only
6425 @emph{approximates} the rebuilds that would be required as a result of
6426 an upgrade. More rebuilds might be required under some circumstances.
6429 $ guix refresh --list-dependent flex
6430 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
6431 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
6434 The command above lists a set of packages that could be built to check
6435 for compatibility with an upgraded @code{flex} package.
6437 The following options can be used to customize GnuPG operation:
6441 @item --gpg=@var{command}
6442 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
6443 for in @code{$PATH}.
6445 @item --key-download=@var{policy}
6446 Handle missing OpenPGP keys according to @var{policy}, which may be one
6451 Always download missing OpenPGP keys from the key server, and add them
6452 to the user's GnuPG keyring.
6455 Never try to download missing OpenPGP keys. Instead just bail out.
6458 When a package signed with an unknown OpenPGP key is encountered, ask
6459 the user whether to download it or not. This is the default behavior.
6462 @item --key-server=@var{host}
6463 Use @var{host} as the OpenPGP key server when importing a public key.
6467 The @code{github} updater uses the
6468 @uref{https://developer.github.com/v3/, GitHub API} to query for new
6469 releases. When used repeatedly e.g. when refreshing all packages,
6470 GitHub will eventually refuse to answer any further API requests. By
6471 default 60 API requests per hour are allowed, and a full refresh on all
6472 GitHub packages in Guix requires more than this. Authentication with
6473 GitHub through the use of an API token alleviates these limits. To use
6474 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
6475 token procured from @uref{https://github.com/settings/tokens} or
6479 @node Invoking guix lint
6480 @section Invoking @command{guix lint}
6482 @cindex @command{guix lint}
6483 @cindex package, checking for errors
6484 The @command{guix lint} command is meant to help package developers avoid
6485 common errors and use a consistent style. It runs a number of checks on
6486 a given set of packages in order to find common mistakes in their
6487 definitions. Available @dfn{checkers} include (see
6488 @code{--list-checkers} for a complete list):
6493 Validate certain typographical and stylistic rules about package
6494 descriptions and synopses.
6496 @item inputs-should-be-native
6497 Identify inputs that should most likely be native inputs.
6502 @itemx source-file-name
6503 Probe @code{home-page} and @code{source} URLs and report those that are
6504 invalid. Suggest a @code{mirror://} URL when applicable. Check that
6505 the source file name is meaningful, e.g. is not
6506 just a version number or ``git-checkout'', without a declared
6507 @code{file-name} (@pxref{origin Reference}).
6510 @cindex security vulnerabilities
6511 @cindex CVE, Common Vulnerabilities and Exposures
6512 Report known vulnerabilities found in the Common Vulnerabilities and
6513 Exposures (CVE) databases of the current and past year
6514 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
6517 To view information about a particular vulnerability, visit pages such as:
6521 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
6523 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
6527 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
6528 @code{CVE-2015-7554}.
6530 Package developers can specify in package recipes the
6531 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
6532 name and version of the package when they differ from the name that Guix
6533 uses, as in this example:
6539 ;; CPE calls this package "grub2".
6540 (properties '((cpe-name . "grub2"))))
6544 Warn about obvious source code formatting issues: trailing white space,
6545 use of tabulations, etc.
6548 The general syntax is:
6551 guix lint @var{options} @var{package}@dots{}
6554 If no package is given on the command line, then all packages are checked.
6555 The @var{options} may be zero or more of the following:
6558 @item --list-checkers
6560 List and describe all the available checkers that will be run on packages
6565 Only enable the checkers specified in a comma-separated list using the
6566 names returned by @code{--list-checkers}.
6570 @node Invoking guix size
6571 @section Invoking @command{guix size}
6574 @cindex package size
6576 @cindex @command{guix size}
6577 The @command{guix size} command helps package developers profile the
6578 disk usage of packages. It is easy to overlook the impact of an
6579 additional dependency added to a package, or the impact of using a
6580 single output for a package that could easily be split (@pxref{Packages
6581 with Multiple Outputs}). Such are the typical issues that
6582 @command{guix size} can highlight.
6584 The command can be passed a package specification such as @code{gcc@@4.8}
6585 or @code{guile:debug}, or a file name in the store. Consider this
6589 $ guix size coreutils
6590 store item total self
6591 /gnu/store/@dots{}-coreutils-8.23 70.0 13.9 19.8%
6592 /gnu/store/@dots{}-gmp-6.0.0a 55.3 2.5 3.6%
6593 /gnu/store/@dots{}-acl-2.2.52 53.7 0.5 0.7%
6594 /gnu/store/@dots{}-attr-2.4.46 53.2 0.3 0.5%
6595 /gnu/store/@dots{}-gcc-4.8.4-lib 52.9 15.7 22.4%
6596 /gnu/store/@dots{}-glibc-2.21 37.2 37.2 53.1%
6600 The store items listed here constitute the @dfn{transitive closure} of
6601 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
6602 would be returned by:
6605 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
6608 Here the output shows three columns next to store items. The first column,
6609 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
6610 the store item---that is, its own size plus the size of all its
6611 dependencies. The next column, labeled ``self'', shows the size of the
6612 item itself. The last column shows the ratio of the size of the item
6613 itself to the space occupied by all the items listed here.
6615 In this example, we see that the closure of Coreutils weighs in at
6616 70@tie{}MiB, half of which is taken by libc. (That libc represents a
6617 large fraction of the closure is not a problem @i{per se} because it is
6618 always available on the system anyway.)
6620 When the package passed to @command{guix size} is available in the
6621 store, @command{guix size} queries the daemon to determine its
6622 dependencies, and measures its size in the store, similar to @command{du
6623 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
6626 When the given package is @emph{not} in the store, @command{guix size}
6627 reports information based on the available substitutes
6628 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
6629 store items that are not even on disk, only available remotely.
6631 You can also specify several package names:
6634 $ guix size coreutils grep sed bash
6635 store item total self
6636 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
6637 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
6638 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
6639 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
6645 In this example we see that the combination of the four packages takes
6646 102.3@tie{}MiB in total, which is much less than the sum of each closure
6647 since they have a lot of dependencies in common.
6649 The available options are:
6653 @item --substitute-urls=@var{urls}
6654 Use substitute information from @var{urls}.
6655 @xref{client-substitute-urls, the same option for @code{guix build}}.
6657 @item --sort=@var{key}
6658 Sort lines according to @var{key}, one of the following options:
6662 the size of each item (the default);
6664 the total size of the item's closure.
6667 @item --map-file=@var{file}
6668 Write a graphical map of disk usage in PNG format to @var{file}.
6670 For the example above, the map looks like this:
6672 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
6673 produced by @command{guix size}}
6675 This option requires that
6676 @uref{http://wingolog.org/software/guile-charting/, Guile-Charting} be
6677 installed and visible in Guile's module search path. When that is not
6678 the case, @command{guix size} fails as it tries to load it.
6680 @item --system=@var{system}
6681 @itemx -s @var{system}
6682 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
6686 @node Invoking guix graph
6687 @section Invoking @command{guix graph}
6690 @cindex @command{guix graph}
6691 @cindex package dependencies
6692 Packages and their dependencies form a @dfn{graph}, specifically a
6693 directed acyclic graph (DAG). It can quickly become difficult to have a
6694 mental model of the package DAG, so the @command{guix graph} command
6695 provides a visual representation of the DAG. By default,
6696 @command{guix graph} emits a DAG representation in the input format of
6697 @uref{http://www.graphviz.org/, Graphviz}, so its output can be passed
6698 directly to the @command{dot} command of Graphviz. It can also emit an
6699 HTML page with embedded JavaScript code to display a ``chord diagram''
6700 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
6701 emit Cypher queries to construct a graph in a graph database supporting
6702 the @uref{http://www.opencypher.org/, openCypher} query language.
6703 The general syntax is:
6706 guix graph @var{options} @var{package}@dots{}
6709 For example, the following command generates a PDF file representing the
6710 package DAG for the GNU@tie{}Core Utilities, showing its build-time
6714 guix graph coreutils | dot -Tpdf > dag.pdf
6717 The output looks like this:
6719 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
6721 Nice little graph, no?
6723 But there is more than one graph! The one above is concise: it is the
6724 graph of package objects, omitting implicit inputs such as GCC, libc,
6725 grep, etc. It is often useful to have such a concise graph, but
6726 sometimes one may want to see more details. @command{guix graph} supports
6727 several types of graphs, allowing you to choose the level of detail:
6731 This is the default type used in the example above. It shows the DAG of
6732 package objects, excluding implicit dependencies. It is concise, but
6733 filters out many details.
6735 @item reverse-package
6736 This shows the @emph{reverse} DAG of packages. For example:
6739 guix graph --type=reverse-package ocaml
6742 ... yields the graph of packages that depend on OCaml.
6744 Note that for core packages this can yield huge graphs. If all you want
6745 is to know the number of packages that depend on a given package, use
6746 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
6747 @option{--list-dependent}}).
6750 This is the package DAG, @emph{including} implicit inputs.
6752 For instance, the following command:
6755 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
6758 ... yields this bigger graph:
6760 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
6762 At the bottom of the graph, we see all the implicit inputs of
6763 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
6765 Now, note that the dependencies of these implicit inputs---that is, the
6766 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
6767 here, for conciseness.
6770 Similar to @code{bag-emerged}, but this time including all the bootstrap
6773 @item bag-with-origins
6774 Similar to @code{bag}, but also showing origins and their dependencies.
6777 This is the most detailed representation: It shows the DAG of
6778 derivations (@pxref{Derivations}) and plain store items. Compared to
6779 the above representation, many additional nodes are visible, including
6780 build scripts, patches, Guile modules, etc.
6782 For this type of graph, it is also possible to pass a @file{.drv} file
6783 name instead of a package name, as in:
6786 guix graph -t derivation `guix system build -d my-config.scm`
6790 All the types above correspond to @emph{build-time dependencies}. The
6791 following graph type represents the @emph{run-time dependencies}:
6795 This is the graph of @dfn{references} of a package output, as returned
6796 by @command{guix gc --references} (@pxref{Invoking guix gc}).
6798 If the given package output is not available in the store, @command{guix
6799 graph} attempts to obtain dependency information from substitutes.
6801 Here you can also pass a store file name instead of a package name. For
6802 example, the command below produces the reference graph of your profile
6803 (which can be big!):
6806 guix graph -t references `readlink -f ~/.guix-profile`
6810 This is the graph of the @dfn{referrers} of a store item, as returned by
6811 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
6813 This relies exclusively on local information from your store. For
6814 instance, let us suppose that the current Inkscape is available in 10
6815 profiles on your machine; @command{guix graph -t referrers inkscape}
6816 will show a graph rooted at Inkscape and with those 10 profiles linked
6819 It can help determine what is preventing a store item from being garbage
6824 The available options are the following:
6827 @item --type=@var{type}
6828 @itemx -t @var{type}
6829 Produce a graph output of @var{type}, where @var{type} must be one of
6830 the values listed above.
6833 List the supported graph types.
6835 @item --backend=@var{backend}
6836 @itemx -b @var{backend}
6837 Produce a graph using the selected @var{backend}.
6839 @item --list-backends
6840 List the supported graph backends.
6842 Currently, the available backends are Graphviz and d3.js.
6844 @item --expression=@var{expr}
6845 @itemx -e @var{expr}
6846 Consider the package @var{expr} evaluates to.
6848 This is useful to precisely refer to a package, as in this example:
6851 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
6856 @node Invoking guix environment
6857 @section Invoking @command{guix environment}
6859 @cindex reproducible build environments
6860 @cindex development environments
6861 @cindex @command{guix environment}
6862 @cindex environment, package build environment
6863 The purpose of @command{guix environment} is to assist hackers in
6864 creating reproducible development environments without polluting their
6865 package profile. The @command{guix environment} tool takes one or more
6866 packages, builds all of their inputs, and creates a shell
6867 environment to use them.
6869 The general syntax is:
6872 guix environment @var{options} @var{package}@dots{}
6875 The following example spawns a new shell set up for the development of
6879 guix environment guile
6882 If the needed dependencies are not built yet, @command{guix environment}
6883 automatically builds them. The environment of the new shell is an augmented
6884 version of the environment that @command{guix environment} was run in.
6885 It contains the necessary search paths for building the given package
6886 added to the existing environment variables. To create a ``pure''
6887 environment, in which the original environment variables have been unset,
6888 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
6889 environment variables such as @code{PATH} in their @file{~/.bashrc}
6890 file. As a consequence, when @code{guix environment} launches it, Bash
6891 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
6892 environment variables. It is an error to define such environment
6893 variables in @file{.bashrc}; instead, they should be defined in
6894 @file{.bash_profile}, which is sourced only by log-in shells.
6895 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
6896 details on Bash start-up files.}.
6898 @vindex GUIX_ENVIRONMENT
6899 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
6900 variable in the shell it spawns; its value is the file name of the
6901 profile of this environment. This allows users to, say, define a
6902 specific prompt for development environments in their @file{.bashrc}
6903 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
6906 if [ -n "$GUIX_ENVIRONMENT" ]
6908 export PS1="\u@@\h \w [dev]\$ "
6913 ... or to browse the profile:
6916 $ ls "$GUIX_ENVIRONMENT/bin"
6919 Additionally, more than one package may be specified, in which case the
6920 union of the inputs for the given packages are used. For example, the
6921 command below spawns a shell where all of the dependencies of both Guile
6922 and Emacs are available:
6925 guix environment guile emacs
6928 Sometimes an interactive shell session is not desired. An arbitrary
6929 command may be invoked by placing the @code{--} token to separate the
6930 command from the rest of the arguments:
6933 guix environment guile -- make -j4
6936 In other situations, it is more convenient to specify the list of
6937 packages needed in the environment. For example, the following command
6938 runs @command{python} from an environment containing Python@tie{}2.7 and
6942 guix environment --ad-hoc python2-numpy python-2.7 -- python
6945 Furthermore, one might want the dependencies of a package and also some
6946 additional packages that are not build-time or runtime dependencies, but
6947 are useful when developing nonetheless. Because of this, the
6948 @code{--ad-hoc} flag is positional. Packages appearing before
6949 @code{--ad-hoc} are interpreted as packages whose dependencies will be
6950 added to the environment. Packages appearing after are interpreted as
6951 packages that will be added to the environment directly. For example,
6952 the following command creates a Guix development environment that
6953 additionally includes Git and strace:
6956 guix environment guix --ad-hoc git strace
6959 Sometimes it is desirable to isolate the environment as much as
6960 possible, for maximal purity and reproducibility. In particular, when
6961 using Guix on a host distro that is not GuixSD, it is desirable to
6962 prevent access to @file{/usr/bin} and other system-wide resources from
6963 the development environment. For example, the following command spawns
6964 a Guile REPL in a ``container'' where only the store and the current
6965 working directory are mounted:
6968 guix environment --ad-hoc --container guile -- guile
6972 The @code{--container} option requires Linux-libre 3.19 or newer.
6975 The available options are summarized below.
6978 @item --root=@var{file}
6979 @itemx -r @var{file}
6980 @cindex persistent environment
6981 @cindex garbage collector root, for environments
6982 Make @var{file} a symlink to the profile for this environment, and
6983 register it as a garbage collector root.
6985 This is useful if you want to protect your environment from garbage
6986 collection, to make it ``persistent''.
6988 When this option is omitted, the environment is protected from garbage
6989 collection only for the duration of the @command{guix environment}
6990 session. This means that next time you recreate the same environment,
6991 you could have to rebuild or re-download packages. @xref{Invoking guix
6992 gc}, for more on GC roots.
6994 @item --expression=@var{expr}
6995 @itemx -e @var{expr}
6996 Create an environment for the package or list of packages that
6997 @var{expr} evaluates to.
6999 For example, running:
7002 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
7005 starts a shell with the environment for this specific variant of the
7011 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
7014 starts a shell with all the GuixSD base packages available.
7016 The above commands only use the default output of the given packages.
7017 To select other outputs, two element tuples can be specified:
7020 guix environment --ad-hoc -e '(list (@ (gnu packages bash) bash) "include")'
7023 @item --load=@var{file}
7024 @itemx -l @var{file}
7025 Create an environment for the package or list of packages that the code
7026 within @var{file} evaluates to.
7028 As an example, @var{file} might contain a definition like this
7029 (@pxref{Defining Packages}):
7032 @verbatiminclude environment-gdb.scm
7036 Include all specified packages in the resulting environment, as if an
7037 @i{ad hoc} package were defined with them as inputs. This option is
7038 useful for quickly creating an environment without having to write a
7039 package expression to contain the desired inputs.
7041 For instance, the command:
7044 guix environment --ad-hoc guile guile-sdl -- guile
7047 runs @command{guile} in an environment where Guile and Guile-SDL are
7050 Note that this example implicitly asks for the default output of
7051 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
7052 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
7053 of @code{glib} (@pxref{Packages with Multiple Outputs}).
7055 This option may be composed with the default behavior of @command{guix
7056 environment}. Packages appearing before @code{--ad-hoc} are interpreted
7057 as packages whose dependencies will be added to the environment, the
7058 default behavior. Packages appearing after are interpreted as packages
7059 that will be added to the environment directly.
7062 Unset existing environment variables when building the new environment.
7063 This has the effect of creating an environment in which search paths
7064 only contain package inputs.
7066 @item --search-paths
7067 Display the environment variable definitions that make up the
7070 @item --system=@var{system}
7071 @itemx -s @var{system}
7072 Attempt to build for @var{system}---e.g., @code{i686-linux}.
7077 Run @var{command} within an isolated container. The current working
7078 directory outside the container is mapped inside the container.
7079 Additionally, a dummy home directory is created that matches the current
7080 user's home directory, and @file{/etc/passwd} is configured accordingly.
7081 The spawned process runs as the current user outside the container, but
7082 has root privileges in the context of the container.
7086 For containers, share the network namespace with the host system.
7087 Containers created without this flag only have access to the loopback
7090 @item --expose=@var{source}[=@var{target}]
7091 For containers, expose the file system @var{source} from the host system
7092 as the read-only file system @var{target} within the container. If
7093 @var{target} is not specified, @var{source} is used as the target mount
7094 point in the container.
7096 The example below spawns a Guile REPL in a container in which the user's
7097 home directory is accessible read-only via the @file{/exchange}
7101 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
7104 @item --share=@var{source}[=@var{target}]
7105 For containers, share the file system @var{source} from the host system
7106 as the writable file system @var{target} within the container. If
7107 @var{target} is not specified, @var{source} is used as the target mount
7108 point in the container.
7110 The example below spawns a Guile REPL in a container in which the user's
7111 home directory is accessible for both reading and writing via the
7112 @file{/exchange} directory:
7115 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
7119 @command{guix environment}
7120 also supports all of the common build options that @command{guix
7121 build} supports (@pxref{Common Build Options}).
7124 @node Invoking guix publish
7125 @section Invoking @command{guix publish}
7127 @cindex @command{guix publish}
7128 The purpose of @command{guix publish} is to enable users to easily share
7129 their store with others, who can then use it as a substitute server
7130 (@pxref{Substitutes}).
7132 When @command{guix publish} runs, it spawns an HTTP server which allows
7133 anyone with network access to obtain substitutes from it. This means
7134 that any machine running Guix can also act as if it were a build farm,
7135 since the HTTP interface is compatible with Hydra, the software behind
7136 the @code{hydra.gnu.org} build farm.
7138 For security, each substitute is signed, allowing recipients to check
7139 their authenticity and integrity (@pxref{Substitutes}). Because
7140 @command{guix publish} uses the signing key of the system, which is only
7141 readable by the system administrator, it must be started as root; the
7142 @code{--user} option makes it drop root privileges early on.
7144 The signing key pair must be generated before @command{guix publish} is
7145 launched, using @command{guix archive --generate-key} (@pxref{Invoking
7148 The general syntax is:
7151 guix publish @var{options}@dots{}
7154 Running @command{guix publish} without any additional arguments will
7155 spawn an HTTP server on port 8080:
7161 Once a publishing server has been authorized (@pxref{Invoking guix
7162 archive}), the daemon may download substitutes from it:
7165 guix-daemon --substitute-urls=http://example.org:8080
7168 By default, @command{guix publish} compresses archives on the fly as it
7169 serves them. This ``on-the-fly'' mode is convenient in that it requires
7170 no setup and is immediately available. However, when serving lots of
7171 clients, we recommend using the @option{--cache} option, which enables
7172 caching of the archives before they are sent to clients---see below for
7173 details. The @command{guix weather} command provides a handy way to
7174 check what a server provides (@pxref{Invoking guix weather}).
7176 As a bonus, @command{guix publish} also serves as a content-addressed
7177 mirror for source files referenced in @code{origin} records
7178 (@pxref{origin Reference}). For instance, assuming @command{guix
7179 publish} is running on @code{example.org}, the following URL returns the
7180 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
7181 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
7184 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
7187 Obviously, these URLs only work for files that are in the store; in
7188 other cases, they return 404 (``Not Found'').
7190 The following options are available:
7193 @item --port=@var{port}
7194 @itemx -p @var{port}
7195 Listen for HTTP requests on @var{port}.
7197 @item --listen=@var{host}
7198 Listen on the network interface for @var{host}. The default is to
7199 accept connections from any interface.
7201 @item --user=@var{user}
7202 @itemx -u @var{user}
7203 Change privileges to @var{user} as soon as possible---i.e., once the
7204 server socket is open and the signing key has been read.
7206 @item --compression[=@var{level}]
7207 @itemx -C [@var{level}]
7208 Compress data using the given @var{level}. When @var{level} is zero,
7209 disable compression. The range 1 to 9 corresponds to different gzip
7210 compression levels: 1 is the fastest, and 9 is the best (CPU-intensive).
7213 Unless @option{--cache} is used, compression occurs on the fly and
7214 the compressed streams are not
7215 cached. Thus, to reduce load on the machine that runs @command{guix
7216 publish}, it may be a good idea to choose a low compression level, to
7217 run @command{guix publish} behind a caching proxy, or to use
7218 @option{--cache}. Using @option{--cache} has the advantage that it
7219 allows @command{guix publish} to add @code{Content-Length} HTTP header
7222 @item --cache=@var{directory}
7223 @itemx -c @var{directory}
7224 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
7225 and only serve archives that are in cache.
7227 When this option is omitted, archives and meta-data are created
7228 on-the-fly. This can reduce the available bandwidth, especially when
7229 compression is enabled, since this may become CPU-bound. Another
7230 drawback of the default mode is that the length of archives is not known
7231 in advance, so @command{guix publish} does not add a
7232 @code{Content-Length} HTTP header to its responses, which in turn
7233 prevents clients from knowing the amount of data being downloaded.
7235 Conversely, when @option{--cache} is used, the first request for a store
7236 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
7237 background process to @dfn{bake} the archive---computing its
7238 @code{.narinfo} and compressing the archive, if needed. Once the
7239 archive is cached in @var{directory}, subsequent requests succeed and
7240 are served directly from the cache, which guarantees that clients get
7241 the best possible bandwidth.
7243 The ``baking'' process is performed by worker threads. By default, one
7244 thread per CPU core is created, but this can be customized. See
7245 @option{--workers} below.
7247 When @option{--ttl} is used, cached entries are automatically deleted
7248 when they have expired.
7250 @item --workers=@var{N}
7251 When @option{--cache} is used, request the allocation of @var{N} worker
7252 threads to ``bake'' archives.
7254 @item --ttl=@var{ttl}
7255 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
7256 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
7257 days, @code{1m} means 1 month, and so on.
7259 This allows the user's Guix to keep substitute information in cache for
7260 @var{ttl}. However, note that @code{guix publish} does not itself
7261 guarantee that the store items it provides will indeed remain available
7262 for as long as @var{ttl}.
7264 Additionally, when @option{--cache} is used, cached entries that have
7265 not been accessed for @var{ttl} and that no longer have a corresponding
7266 item in the store, may be deleted.
7268 @item --nar-path=@var{path}
7269 Use @var{path} as the prefix for the URLs of ``nar'' files
7270 (@pxref{Invoking guix archive, normalized archives}).
7272 By default, nars are served at a URL such as
7273 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
7274 change the @code{/nar} part to @var{path}.
7276 @item --public-key=@var{file}
7277 @itemx --private-key=@var{file}
7278 Use the specific @var{file}s as the public/private key pair used to sign
7279 the store items being published.
7281 The files must correspond to the same key pair (the private key is used
7282 for signing and the public key is merely advertised in the signature
7283 metadata). They must contain keys in the canonical s-expression format
7284 as produced by @command{guix archive --generate-key} (@pxref{Invoking
7285 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
7286 @file{/etc/guix/signing-key.sec} are used.
7288 @item --repl[=@var{port}]
7289 @itemx -r [@var{port}]
7290 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
7291 Reference Manual}) on @var{port} (37146 by default). This is used
7292 primarily for debugging a running @command{guix publish} server.
7295 Enabling @command{guix publish} on a GuixSD system is a one-liner: just
7296 instantiate a @code{guix-publish-service-type} service in the @code{services} field
7297 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
7298 @code{guix-publish-service-type}}).
7300 If you are instead running Guix on a ``foreign distro'', follow these
7305 If your host distro uses the systemd init system:
7308 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
7309 /etc/systemd/system/
7310 # systemctl start guix-publish && systemctl enable guix-publish
7314 If your host distro uses the Upstart init system:
7317 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
7318 # start guix-publish
7322 Otherwise, proceed similarly with your distro's init system.
7325 @node Invoking guix challenge
7326 @section Invoking @command{guix challenge}
7328 @cindex reproducible builds
7329 @cindex verifiable builds
7330 @cindex @command{guix challenge}
7332 Do the binaries provided by this server really correspond to the source
7333 code it claims to build? Is a package build process deterministic?
7334 These are the questions the @command{guix challenge} command attempts to
7337 The former is obviously an important question: Before using a substitute
7338 server (@pxref{Substitutes}), one had better @emph{verify} that it
7339 provides the right binaries, and thus @emph{challenge} it. The latter
7340 is what enables the former: If package builds are deterministic, then
7341 independent builds of the package should yield the exact same result,
7342 bit for bit; if a server provides a binary different from the one
7343 obtained locally, it may be either corrupt or malicious.
7345 We know that the hash that shows up in @file{/gnu/store} file names is
7346 the hash of all the inputs of the process that built the file or
7347 directory---compilers, libraries, build scripts,
7348 etc. (@pxref{Introduction}). Assuming deterministic build processes,
7349 one store file name should map to exactly one build output.
7350 @command{guix challenge} checks whether there is, indeed, a single
7351 mapping by comparing the build outputs of several independent builds of
7352 any given store item.
7354 The command output looks like this:
7357 $ guix challenge --substitute-urls="https://hydra.gnu.org https://guix.example.org"
7358 updating list of substitutes from 'https://hydra.gnu.org'... 100.0%
7359 updating list of substitutes from 'https://guix.example.org'... 100.0%
7360 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
7361 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
7362 https://hydra.gnu.org/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
7363 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
7364 /gnu/store/@dots{}-git-2.5.0 contents differ:
7365 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
7366 https://hydra.gnu.org/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
7367 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
7368 /gnu/store/@dots{}-pius-2.1.1 contents differ:
7369 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
7370 https://hydra.gnu.org/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
7371 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
7375 6,406 store items were analyzed:
7376 - 4,749 (74.1%) were identical
7377 - 525 (8.2%) differed
7378 - 1,132 (17.7%) were inconclusive
7382 In this example, @command{guix challenge} first scans the store to
7383 determine the set of locally-built derivations---as opposed to store
7384 items that were downloaded from a substitute server---and then queries
7385 all the substitute servers. It then reports those store items for which
7386 the servers obtained a result different from the local build.
7388 @cindex non-determinism, in package builds
7389 As an example, @code{guix.example.org} always gets a different answer.
7390 Conversely, @code{hydra.gnu.org} agrees with local builds, except in the
7391 case of Git. This might indicate that the build process of Git is
7392 non-deterministic, meaning that its output varies as a function of
7393 various things that Guix does not fully control, in spite of building
7394 packages in isolated environments (@pxref{Features}). Most common
7395 sources of non-determinism include the addition of timestamps in build
7396 results, the inclusion of random numbers, and directory listings sorted
7397 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
7400 To find out what is wrong with this Git binary, we can do something along
7401 these lines (@pxref{Invoking guix archive}):
7404 $ wget -q -O - https://hydra.gnu.org/nar/@dots{}-git-2.5.0 \
7405 | guix archive -x /tmp/git
7406 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
7409 This command shows the difference between the files resulting from the
7410 local build, and the files resulting from the build on
7411 @code{hydra.gnu.org} (@pxref{Overview, Comparing and Merging Files,,
7412 diffutils, Comparing and Merging Files}). The @command{diff} command
7413 works great for text files. When binary files differ, a better option
7414 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
7415 visualize differences for all kinds of files.
7417 Once you have done that work, you can tell whether the differences are due
7418 to a non-deterministic build process or to a malicious server. We try
7419 hard to remove sources of non-determinism in packages to make it easier
7420 to verify substitutes, but of course, this is a process that
7421 involves not just Guix, but a large part of the free software community.
7422 In the meantime, @command{guix challenge} is one tool to help address
7425 If you are writing packages for Guix, you are encouraged to check
7426 whether @code{hydra.gnu.org} and other substitute servers obtain the
7427 same build result as you did with:
7430 $ guix challenge @var{package}
7434 where @var{package} is a package specification such as
7435 @code{guile@@2.0} or @code{glibc:debug}.
7437 The general syntax is:
7440 guix challenge @var{options} [@var{packages}@dots{}]
7443 When a difference is found between the hash of a locally-built item and
7444 that of a server-provided substitute, or among substitutes provided by
7445 different servers, the command displays it as in the example above and
7446 its exit code is 2 (other non-zero exit codes denote other kinds of
7449 The one option that matters is:
7453 @item --substitute-urls=@var{urls}
7454 Consider @var{urls} the whitespace-separated list of substitute source
7459 Show details about matches (identical contents) in addition to
7460 information about mismatches.
7464 @node Invoking guix copy
7465 @section Invoking @command{guix copy}
7467 @cindex copy, of store items, over SSH
7468 @cindex SSH, copy of store items
7469 @cindex sharing store items across machines
7470 @cindex transferring store items across machines
7471 The @command{guix copy} command copies items from the store of one
7472 machine to that of another machine over a secure shell (SSH)
7473 connection@footnote{This command is available only when Guile-SSH was
7474 found. @xref{Requirements}, for details.}. For example, the following
7475 command copies the @code{coreutils} package, the user's profile, and all
7476 their dependencies over to @var{host}, logged in as @var{user}:
7479 guix copy --to=@var{user}@@@var{host} \
7480 coreutils `readlink -f ~/.guix-profile`
7483 If some of the items to be copied are already present on @var{host},
7484 they are not actually sent.
7486 The command below retrieves @code{libreoffice} and @code{gimp} from
7487 @var{host}, assuming they are available there:
7490 guix copy --from=@var{host} libreoffice gimp
7493 The SSH connection is established using the Guile-SSH client, which is
7494 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
7495 @file{~/.ssh/config}, and uses the SSH agent for authentication.
7497 The key used to sign items that are sent must be accepted by the remote
7498 machine. Likewise, the key used by the remote machine to sign items you
7499 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
7500 own daemon. @xref{Invoking guix archive}, for more information about
7501 store item authentication.
7503 The general syntax is:
7506 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
7509 You must always specify one of the following options:
7512 @item --to=@var{spec}
7513 @itemx --from=@var{spec}
7514 Specify the host to send to or receive from. @var{spec} must be an SSH
7515 spec such as @code{example.org}, @code{charlie@@example.org}, or
7516 @code{charlie@@example.org:2222}.
7519 The @var{items} can be either package names, such as @code{gimp}, or
7520 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
7522 When specifying the name of a package to send, it is first built if
7523 needed, unless @option{--dry-run} was specified. Common build options
7524 are supported (@pxref{Common Build Options}).
7527 @node Invoking guix container
7528 @section Invoking @command{guix container}
7530 @cindex @command{guix container}
7532 As of version @value{VERSION}, this tool is experimental. The interface
7533 is subject to radical change in the future.
7536 The purpose of @command{guix container} is to manipulate processes
7537 running within an isolated environment, commonly known as a
7538 ``container'', typically created by the @command{guix environment}
7539 (@pxref{Invoking guix environment}) and @command{guix system container}
7540 (@pxref{Invoking guix system}) commands.
7542 The general syntax is:
7545 guix container @var{action} @var{options}@dots{}
7548 @var{action} specifies the operation to perform with a container, and
7549 @var{options} specifies the context-specific arguments for the action.
7551 The following actions are available:
7555 Execute a command within the context of a running container.
7560 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
7563 @var{pid} specifies the process ID of the running container.
7564 @var{program} specifies an executable file name within the root file
7565 system of the container. @var{arguments} are the additional options that
7566 will be passed to @var{program}.
7568 The following command launches an interactive login shell inside a
7569 GuixSD container, started by @command{guix system container}, and whose
7573 guix container exec 9001 /run/current-system/profile/bin/bash --login
7576 Note that the @var{pid} cannot be the parent process of a container. It
7577 must be PID 1 of the container or one of its child processes.
7581 @node Invoking guix weather
7582 @section Invoking @command{guix weather}
7584 Occasionally you're grumpy because substitutes are lacking and you end
7585 up building packages by yourself (@pxref{Substitutes}). The
7586 @command{guix weather} command reports on substitute availability on the
7587 specified servers so you can have an idea of whether you'll be grumpy
7588 today. It can sometimes be useful info as a user, but it is primarily
7589 useful to people running @command{guix publish} (@pxref{Invoking guix
7592 @cindex statistics, for substitutes
7593 @cindex availability of substitutes
7594 @cindex substitute availability
7595 @cindex weather, substitute availability
7596 Here's a sample run:
7599 $ guix weather --substitute-urls=https://guix.example.org
7600 computing 5,872 package derivations for x86_64-linux...
7601 looking for 6,128 store items on https://guix.example.org..
7602 updating list of substitutes from 'https://guix.example.org'... 100.0%
7603 https://guix.example.org
7604 43.4% substitutes available (2,658 out of 6,128)
7605 7,032.5 MiB of nars (compressed)
7606 19,824.2 MiB on disk (uncompressed)
7607 0.030 seconds per request (182.9 seconds in total)
7608 33.5 requests per second
7611 As you can see, it reports the fraction of all the packages for which
7612 substitutes are available on the server---regardless of whether
7613 substitutes are enabled, and regardless of whether this server's signing
7614 key is authorized. It also reports the size of the compressed archives
7615 (``nars'') provided by the server, the size the corresponding store
7616 items occupy in the store (assuming deduplication is turned off), and
7617 the server's throughput.
7619 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
7620 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
7621 challenge}, it ignores signatures on those substitutes, which is
7622 innocuous since the command only gathers statistics and cannot install
7625 Among other things, it is possible to query specific system types and
7626 specific package sets. The available options are listed below.
7629 @item --substitute-urls=@var{urls}
7630 @var{urls} is the space-separated list of substitute server URLs to
7631 query. When this option is omitted, the default set of substitute
7634 @item --system=@var{system}
7635 @itemx -s @var{system}
7636 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
7637 option can be repeated, in which case @command{guix weather} will query
7638 substitutes for several system types.
7640 @item --manifest=@var{file}
7641 Instead of querying substitutes for all the packages, only ask for those
7642 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
7643 with the @code{-m} option of @command{guix package} (@pxref{Invoking
7648 @c *********************************************************************
7649 @node GNU Distribution
7650 @chapter GNU Distribution
7652 @cindex Guix System Distribution
7654 Guix comes with a distribution of the GNU system consisting entirely of
7655 free software@footnote{The term ``free'' here refers to the
7656 @url{http://www.gnu.org/philosophy/free-sw.html,freedom provided to
7657 users of that software}.}. The
7658 distribution can be installed on its own (@pxref{System Installation}),
7659 but it is also possible to install Guix as a package manager on top of
7660 an installed GNU/Linux system (@pxref{Installation}). To distinguish
7661 between the two, we refer to the standalone distribution as the Guix
7662 System Distribution, or GuixSD.
7664 The distribution provides core GNU packages such as GNU libc, GCC, and
7665 Binutils, as well as many GNU and non-GNU applications. The complete
7666 list of available packages can be browsed
7667 @url{http://www.gnu.org/software/guix/packages,on-line} or by
7668 running @command{guix package} (@pxref{Invoking guix package}):
7671 guix package --list-available
7674 Our goal is to provide a practical 100% free software distribution of
7675 Linux-based and other variants of GNU, with a focus on the promotion and
7676 tight integration of GNU components, and an emphasis on programs and
7677 tools that help users exert that freedom.
7679 Packages are currently available on the following platforms:
7684 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
7687 Intel 32-bit architecture (IA32), Linux-Libre kernel;
7690 ARMv7-A architecture with hard float, Thumb-2 and NEON,
7691 using the EABI hard-float application binary interface (ABI),
7692 and Linux-Libre kernel.
7695 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel. This is
7696 currently in an experimental stage, with limited support.
7697 @xref{Contributing}, for how to help!
7699 @item mips64el-linux
7700 little-endian 64-bit MIPS processors, specifically the Loongson series,
7701 n32 ABI, and Linux-Libre kernel.
7705 GuixSD itself is currently only available on @code{i686} and @code{x86_64}.
7708 For information on porting to other architectures or kernels,
7712 * System Installation:: Installing the whole operating system.
7713 * System Configuration:: Configuring the operating system.
7714 * Documentation:: Browsing software user manuals.
7715 * Installing Debugging Files:: Feeding the debugger.
7716 * Security Updates:: Deploying security fixes quickly.
7717 * Package Modules:: Packages from the programmer's viewpoint.
7718 * Packaging Guidelines:: Growing the distribution.
7719 * Bootstrapping:: GNU/Linux built from scratch.
7720 * Porting:: Targeting another platform or kernel.
7723 Building this distribution is a cooperative effort, and you are invited
7724 to join! @xref{Contributing}, for information about how you can help.
7726 @node System Installation
7727 @section System Installation
7729 @cindex installing GuixSD
7730 @cindex Guix System Distribution
7731 This section explains how to install the Guix System Distribution (GuixSD)
7732 on a machine. The Guix package manager can
7733 also be installed on top of a running GNU/Linux system,
7734 @pxref{Installation}.
7738 @c This paragraph is for people reading this from tty2 of the
7739 @c installation image.
7740 You are reading this documentation with an Info reader. For details on
7741 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
7742 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
7743 Info}. Hit @kbd{l} afterwards to come back here.
7745 Alternately, run @command{info info} in another tty to keep the manual
7751 * Limitations:: What you can expect.
7752 * Hardware Considerations:: Supported hardware.
7753 * USB Stick Installation:: Preparing the installation medium.
7754 * DVD Installation:: Preparing the installation medium.
7755 * Preparing for Installation:: Networking, partitioning, etc.
7756 * Proceeding with the Installation:: The real thing.
7757 * Installing GuixSD in a VM:: GuixSD playground.
7758 * Building the Installation Image:: How this comes to be.
7762 @subsection Limitations
7764 As of version @value{VERSION}, the Guix System Distribution (GuixSD) is
7765 not production-ready. It may contain bugs and lack important
7766 features. Thus, if you are looking for a stable production system that
7767 respects your freedom as a computer user, a good solution at this point
7768 is to consider @url{http://www.gnu.org/distros/free-distros.html, one of
7769 the more established GNU/Linux distributions}. We hope you can soon switch
7770 to the GuixSD without fear, of course. In the meantime, you can
7771 also keep using your distribution and try out the package manager on top
7772 of it (@pxref{Installation}).
7774 Before you proceed with the installation, be aware of the following
7775 noteworthy limitations applicable to version @value{VERSION}:
7779 The installation process does not include a graphical user interface and
7780 requires familiarity with GNU/Linux (see the following subsections to
7781 get a feel of what that means.)
7784 Support for the Logical Volume Manager (LVM) is missing.
7787 More and more system services are provided (@pxref{Services}), but some
7791 More than 6,500 packages are available, but you might
7792 occasionally find that a useful package is missing.
7795 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
7796 as well as a number of X11 window managers. However, some graphical
7797 applications may be missing, as well as KDE.
7800 You have been warned! But more than a disclaimer, this is an invitation
7801 to report issues (and success stories!), and to join us in improving it.
7802 @xref{Contributing}, for more info.
7805 @node Hardware Considerations
7806 @subsection Hardware Considerations
7808 @cindex hardware support on GuixSD
7809 GNU@tie{}GuixSD focuses on respecting the user's computing freedom. It
7810 builds around the kernel Linux-libre, which means that only hardware for
7811 which free software drivers and firmware exist is supported. Nowadays,
7812 a wide range of off-the-shelf hardware is supported on
7813 GNU/Linux-libre---from keyboards to graphics cards to scanners and
7814 Ethernet controllers. Unfortunately, there are still areas where
7815 hardware vendors deny users control over their own computing, and such
7816 hardware is not supported on GuixSD.
7818 @cindex WiFi, hardware support
7819 One of the main areas where free drivers or firmware are lacking is WiFi
7820 devices. WiFi devices known to work include those using Atheros chips
7821 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
7822 driver, and those using Broadcom/AirForce chips (BCM43xx with
7823 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
7824 Linux-libre driver. Free firmware exists for both and is available
7825 out-of-the-box on GuixSD, as part of @var{%base-firmware}
7826 (@pxref{operating-system Reference, @code{firmware}}).
7828 @cindex RYF, Respects Your Freedom
7829 The @uref{https://www.fsf.org/, Free Software Foundation} runs
7830 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
7831 certification program for hardware products that respect your freedom
7832 and your privacy and ensure that you have control over your device. We
7833 encourage you to check the list of RYF-certified devices.
7835 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
7836 web site. It contains a catalog of hardware devices with information
7837 about their support in GNU/Linux.
7840 @node USB Stick Installation
7841 @subsection USB Stick Installation
7843 An installation image for USB sticks can be downloaded from
7844 @indicateurl{ftp://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.xz},
7845 where @var{system} is one of:
7849 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
7852 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
7855 @c start duplication of authentication part from ``Binary Installation''
7856 Make sure to download the associated @file{.sig} file and to verify the
7857 authenticity of the image against it, along these lines:
7860 $ wget ftp://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.xz.sig
7861 $ gpg --verify guixsd-install-@value{VERSION}.@var{system}.xz.sig
7864 If that command fails because you do not have the required public key,
7865 then run this command to import it:
7868 $ gpg --keyserver pgp.mit.edu --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
7872 and rerun the @code{gpg --verify} command.
7875 This image contains the tools necessary for an installation.
7876 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
7878 To copy the image to a USB stick, follow these steps:
7882 Decompress the image using the @command{xz} command:
7885 xz -d guixsd-install-@value{VERSION}.@var{system}.xz
7889 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
7890 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
7891 copy the image with:
7894 dd if=guixsd-install-@value{VERSION}.x86_64 of=/dev/sdX
7898 Access to @file{/dev/sdX} usually requires root privileges.
7901 Once this is done, you should be able to reboot the system and boot from
7902 the USB stick. The latter usually requires you to get in the BIOS or
7903 UEFI boot menu, where you can choose to boot from the USB stick.
7905 @xref{Installing GuixSD in a VM}, if, instead, you would like to install
7906 GuixSD in a virtual machine (VM).
7908 @node DVD Installation
7909 @subsection DVD Installation
7911 An installation image for DVDs can be downloaded from
7912 @indicateurl{ftp://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.xz},
7913 where @var{system} is one of:
7917 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
7920 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
7923 @c start duplication of authentication part from ``Binary Installation''
7924 Make sure to download the associated @file{.sig} file and to verify the
7925 authenticity of the image against it, along these lines:
7928 $ wget ftp://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.xz.sig
7929 $ gpg --verify guixsd-install-@value{VERSION}.@var{system}.xz.sig
7932 If that command fails because you do not have the required public key,
7933 then run this command to import it:
7936 $ gpg --keyserver pgp.mit.edu --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
7940 and rerun the @code{gpg --verify} command.
7943 This image contains the tools necessary for an installation.
7944 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
7946 To copy the image to a DVD, follow these steps:
7950 Decompress the image using the @command{xz} command:
7953 xz -d guixsd-install-@value{VERSION}.@var{system}.xz
7957 Insert a blank DVD into your machine, and determine
7958 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
7959 copy the image with:
7962 growisofs -dvd-compat -Z /dev/srX=guixsd-install-@value{VERSION}.x86_64
7965 Access to @file{/dev/srX} usually requires root privileges.
7968 Once this is done, you should be able to reboot the system and boot from
7969 the DVD. The latter usually requires you to get in the BIOS or
7970 UEFI boot menu, where you can choose to boot from the DVD.
7972 @xref{Installing GuixSD in a VM}, if, instead, you would like to install
7973 GuixSD in a virtual machine (VM).
7975 @node Preparing for Installation
7976 @subsection Preparing for Installation
7978 Once you have successfully booted your computer using the installation medium,
7979 you should end up with a root prompt. Several console TTYs are configured
7980 and can be used to run commands as root. TTY2 shows this documentation,
7981 browsable using the Info reader commands (@pxref{Top,,, info-stnd,
7982 Stand-alone GNU Info}). The installation system runs the GPM mouse
7983 daemon, which allows you to select text with the left mouse button and
7984 to paste it with the middle button.
7987 Installation requires access to the Internet so that any missing
7988 dependencies of your system configuration can be downloaded. See the
7989 ``Networking'' section below.
7992 The installation system includes many common tools needed for this task.
7993 But it is also a full-blown GuixSD system, which means that you can
7994 install additional packages, should you need it, using @command{guix
7995 package} (@pxref{Invoking guix package}).
7997 @subsubsection Keyboard Layout
7999 @cindex keyboard layout
8000 The installation image uses the US qwerty keyboard layout. If you want
8001 to change it, you can use the @command{loadkeys} command. For example,
8002 the following command selects the Dvorak keyboard layout:
8008 See the files under @file{/run/current-system/profile/share/keymaps} for
8009 a list of available keyboard layouts. Run @command{man loadkeys} for
8012 @subsubsection Networking
8014 Run the following command see what your network interfaces are called:
8021 @dots{} or, using the GNU/Linux-specific @command{ip} command:
8027 @c http://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
8028 Wired interfaces have a name starting with @samp{e}; for example, the
8029 interface corresponding to the first on-board Ethernet controller is
8030 called @samp{eno1}. Wireless interfaces have a name starting with
8031 @samp{w}, like @samp{w1p2s0}.
8034 @item Wired connection
8035 To configure a wired network run the following command, substituting
8036 @var{interface} with the name of the wired interface you want to use.
8039 ifconfig @var{interface} up
8042 @item Wireless connection
8045 To configure wireless networking, you can create a configuration file
8046 for the @command{wpa_supplicant} configuration tool (its location is not
8047 important) using one of the available text editors such as
8051 zile wpa_supplicant.conf
8054 As an example, the following stanza can go to this file and will work
8055 for many wireless networks, provided you give the actual SSID and
8056 passphrase for the network you are connecting to:
8060 ssid="@var{my-ssid}"
8062 psk="the network's secret passphrase"
8066 Start the wireless service and run it in the background with the
8067 following command (substitute @var{interface} with the name of the
8068 network interface you want to use):
8071 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
8074 Run @command{man wpa_supplicant} for more information.
8078 At this point, you need to acquire an IP address. On a network where IP
8079 addresses are automatically assigned @i{via} DHCP, you can run:
8082 dhclient -v @var{interface}
8085 Try to ping a server to see if networking is up and running:
8091 Setting up network access is almost always a requirement because the
8092 image does not contain all the software and tools that may be needed.
8094 @cindex installing over SSH
8095 If you want to, you can continue the installation remotely by starting
8099 herd start ssh-daemon
8102 Make sure to either set a password with @command{passwd}, or configure
8103 OpenSSH public key authentication before logging in.
8105 @subsubsection Disk Partitioning
8107 Unless this has already been done, the next step is to partition, and
8108 then format the target partition(s).
8110 The installation image includes several partitioning tools, including
8111 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
8112 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
8113 the partition layout you want:
8119 If your disk uses the GUID Partition Table (GPT) format and you plan to
8120 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
8121 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
8124 @cindex EFI, installation
8125 @cindex UEFI, installation
8126 @cindex ESP, EFI system partition
8127 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
8128 (ESP) is required. This partition should be mounted at @file{/boot/efi} and
8129 must have the @code{esp} flag set. E.g., for @command{parted}:
8132 parted /dev/sda set 1 esp on
8135 Once you are done partitioning the target hard disk drive, you have to
8136 create a file system on the relevant partition(s)@footnote{Currently
8137 GuixSD only supports ext4 and btrfs file systems. In particular, code
8138 that reads partition UUIDs and labels only works for these file system
8139 types.}. For the ESP, if you have one and assuming it is
8140 @file{/dev/sda2}, run:
8143 mkfs.fat -F32 /dev/sda2
8146 Preferably, assign file systems a label so that you can easily and
8147 reliably refer to them in @code{file-system} declarations (@pxref{File
8148 Systems}). This is typically done using the @code{-L} option of
8149 @command{mkfs.ext4} and related commands. So, assuming the target root
8150 partition lives at @file{/dev/sda1}, a file system with the label
8151 @code{my-root} can be created with:
8154 mkfs.ext4 -L my-root /dev/sda1
8157 @cindex encrypted disk
8158 If you are instead planning to encrypt the root partition, you can use
8159 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
8160 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
8161 @code{man cryptsetup}} for more information.) Assuming you want to
8162 store the root partition on @file{/dev/sda1}, the command sequence would
8163 be along these lines:
8166 cryptsetup luksFormat /dev/sda1
8167 cryptsetup open --type luks /dev/sda1 my-partition
8168 mkfs.ext4 -L my-root /dev/mapper/my-partition
8171 Once that is done, mount the target file system under @file{/mnt}
8172 with a command like (again, assuming @code{my-root} is the label of the
8176 mount LABEL=my-root /mnt
8179 Also mount any other partitions you would like to use on the target
8180 system relative to this path. If you have @file{/boot} on a separate
8181 partition for example, mount it at @file{/mnt/boot} now so it is found
8182 by @code{guix system init} afterwards.
8184 Finally, if you plan to use one or more swap partitions (@pxref{Memory
8185 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
8186 sure to initialize them with @command{mkswap}. Assuming you have one
8187 swap partition on @file{/dev/sda2}, you would run:
8194 Alternatively, you may use a swap file. For example, assuming that in
8195 the new system you want to use the file @file{/swapfile} as a swap file,
8196 you would run@footnote{This example will work for many types of file
8197 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
8198 btrfs), the required steps may be different. For details, see the
8199 manual pages for @command{mkswap} and @command{swapon}.}:
8202 # This is 10 GiB of swap space. Adjust "count" to change the size.
8203 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
8204 # For security, make the file readable and writable only by root.
8205 chmod 600 /mnt/swapfile
8206 mkswap /mnt/swapfile
8207 swapon /mnt/swapfile
8210 Note that if you have encrypted the root partition and created a swap
8211 file in its file system as described above, then the encryption also
8212 protects the swap file, just like any other file in that file system.
8214 @node Proceeding with the Installation
8215 @subsection Proceeding with the Installation
8217 With the target partitions ready and the target root mounted on
8218 @file{/mnt}, we're ready to go. First, run:
8221 herd start cow-store /mnt
8224 This makes @file{/gnu/store} copy-on-write, such that packages added to it
8225 during the installation phase are written to the target disk on @file{/mnt}
8226 rather than kept in memory. This is necessary because the first phase of
8227 the @command{guix system init} command (see below) entails downloads or
8228 builds to @file{/gnu/store} which, initially, is an in-memory file system.
8230 Next, you have to edit a file and
8231 provide the declaration of the operating system to be installed. To
8232 that end, the installation system comes with three text editors: GNU nano
8233 (@pxref{Top,,, nano, GNU nano Manual}), GNU Zile (an Emacs clone), and
8234 nvi (a clone of the original BSD @command{vi} editor).
8235 We strongly recommend storing that file on the target root file system, say,
8236 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
8237 configuration file once you have rebooted into the newly-installed system.
8239 @xref{Using the Configuration System}, for an overview of the
8240 configuration file. The example configurations discussed in that
8241 section are available under @file{/etc/configuration} in the
8242 installation image. Thus, to get started with a system configuration
8243 providing a graphical display server (a ``desktop'' system), you can run
8244 something along these lines:
8248 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
8249 # zile /mnt/etc/config.scm
8252 You should pay attention to what your configuration file contains, and
8257 Make sure the @code{grub-configuration} form refers to the target you
8258 want to install GRUB on. It should mention @code{grub-bootloader} if
8259 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
8260 for newer UEFI systems. For legacy systems, the @code{target} field
8261 names a device, like @code{/dev/sda}; for UEFI systems it names a path
8262 to a mounted EFI partition, like @code{/boot/efi}, and do make sure the
8263 path is actually mounted.
8266 Be sure that your partition labels match the value of their respective
8267 @code{device} fields in your @code{file-system} configuration, assuming
8268 your @code{file-system} configuration sets the value of @code{title} to
8272 If there are encrypted or RAID partitions, make sure to add a
8273 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
8276 Once you are done preparing the configuration file, the new system must
8277 be initialized (remember that the target root file system is mounted
8281 guix system init /mnt/etc/config.scm /mnt
8285 This copies all the necessary files and installs GRUB on
8286 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
8287 more information, @pxref{Invoking guix system}. This command may trigger
8288 downloads or builds of missing packages, which can take some time.
8290 Once that command has completed---and hopefully succeeded!---you can run
8291 @command{reboot} and boot into the new system. The @code{root} password
8292 in the new system is initially empty; other users' passwords need to be
8293 initialized by running the @command{passwd} command as @code{root},
8294 unless your configuration specifies otherwise
8295 (@pxref{user-account-password, user account passwords}).
8297 @cindex upgrading GuixSD
8298 From then on, you can update GuixSD whenever you want by running
8299 @command{guix pull} as @code{root} (@pxref{Invoking guix pull}), and
8300 then running @command{guix system reconfigure} to build a new system
8301 generation with the latest packages and services (@pxref{Invoking guix
8302 system}). We recommend doing that regularly so that your system
8303 includes the latest security updates (@pxref{Security Updates}).
8305 Join us on @code{#guix} on the Freenode IRC network or on
8306 @file{guix-devel@@gnu.org} to share your experience---good or not so
8309 @node Installing GuixSD in a VM
8310 @subsection Installing GuixSD in a Virtual Machine
8312 @cindex virtual machine, GuixSD installation
8313 @cindex virtual private server (VPS)
8314 @cindex VPS (virtual private server)
8315 If you'd like to install GuixSD in a virtual machine (VM) or on a
8316 virtual private server (VPS) rather than on your beloved machine, this
8319 To boot a @uref{http://qemu.org/,QEMU} VM for installing GuixSD in a
8320 disk image, follow these steps:
8324 First, retrieve and decompress the GuixSD installation image as
8325 described previously (@pxref{USB Stick Installation}).
8328 Create a disk image that will hold the installed system. To make a
8329 qcow2-formatted disk image, use the @command{qemu-img} command:
8332 qemu-img create -f qcow2 guixsd.img 50G
8335 The resulting file will be much smaller than 50 GB (typically less than
8336 1 MB), but it will grow as the virtualized storage device is filled up.
8339 Boot the USB installation image in an VM:
8342 qemu-system-x86_64 -m 1024 -smp 1 \
8343 -net user -net nic,model=virtio -boot menu=on \
8344 -drive file=guixsd-install-@value{VERSION}.@var{system} \
8345 -drive file=guixsd.img
8348 The ordering of the drives matters.
8350 In the VM console, quickly press the @kbd{F12} key to enter the boot
8351 menu. Then press the @kbd{2} key and the @kbd{RET} key to validate your
8355 You're now root in the VM, proceed with the installation process.
8356 @xref{Preparing for Installation}, and follow the instructions.
8359 Once installation is complete, you can boot the system that's on your
8360 @file{guixsd.img} image. @xref{Running GuixSD in a VM}, for how to do
8363 @node Building the Installation Image
8364 @subsection Building the Installation Image
8366 @cindex installation image
8367 The installation image described above was built using the @command{guix
8368 system} command, specifically:
8371 guix system disk-image gnu/system/install.scm
8374 Have a look at @file{gnu/system/install.scm} in the source tree,
8375 and see also @ref{Invoking guix system} for more information
8376 about the installation image.
8378 @node System Configuration
8379 @section System Configuration
8381 @cindex system configuration
8382 The Guix System Distribution supports a consistent whole-system configuration
8383 mechanism. By that we mean that all aspects of the global system
8384 configuration---such as the available system services, timezone and
8385 locale settings, user accounts---are declared in a single place. Such
8386 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
8388 One of the advantages of putting all the system configuration under the
8389 control of Guix is that it supports transactional system upgrades, and
8390 makes it possible to roll back to a previous system instantiation,
8391 should something go wrong with the new one (@pxref{Features}). Another
8392 advantage is that it makes it easy to replicate the exact same configuration
8393 across different machines, or at different points in time, without
8394 having to resort to additional administration tools layered on top of
8395 the own tools of the system.
8396 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
8398 This section describes this mechanism. First we focus on the system
8399 administrator's viewpoint---explaining how the system is configured and
8400 instantiated. Then we show how this mechanism can be extended, for
8401 instance to support new system services.
8404 * Using the Configuration System:: Customizing your GNU system.
8405 * operating-system Reference:: Detail of operating-system declarations.
8406 * File Systems:: Configuring file system mounts.
8407 * Mapped Devices:: Block device extra processing.
8408 * User Accounts:: Specifying user accounts.
8409 * Locales:: Language and cultural convention settings.
8410 * Services:: Specifying system services.
8411 * Setuid Programs:: Programs running with root privileges.
8412 * X.509 Certificates:: Authenticating HTTPS servers.
8413 * Name Service Switch:: Configuring libc's name service switch.
8414 * Initial RAM Disk:: Linux-Libre bootstrapping.
8415 * Bootloader Configuration:: Configuring the boot loader.
8416 * Invoking guix system:: Instantiating a system configuration.
8417 * Running GuixSD in a VM:: How to run GuixSD in a virtual machine.
8418 * Defining Services:: Adding new service definitions.
8421 @node Using the Configuration System
8422 @subsection Using the Configuration System
8424 The operating system is configured by providing an
8425 @code{operating-system} declaration in a file that can then be passed to
8426 the @command{guix system} command (@pxref{Invoking guix system}). A
8427 simple setup, with the default system services, the default Linux-Libre
8428 kernel, initial RAM disk, and boot loader looks like this:
8430 @findex operating-system
8432 @include os-config-bare-bones.texi
8435 This example should be self-describing. Some of the fields defined
8436 above, such as @code{host-name} and @code{bootloader}, are mandatory.
8437 Others, such as @code{packages} and @code{services}, can be omitted, in
8438 which case they get a default value.
8440 Below we discuss the effect of some of the most important fields
8441 (@pxref{operating-system Reference}, for details about all the available
8442 fields), and how to @dfn{instantiate} the operating system using
8443 @command{guix system}.
8445 @unnumberedsubsubsec Globally-Visible Packages
8447 @vindex %base-packages
8448 The @code{packages} field lists packages that will be globally visible
8449 on the system, for all user accounts---i.e., in every user's @code{PATH}
8450 environment variable---in addition to the per-user profiles
8451 (@pxref{Invoking guix package}). The @var{%base-packages} variable
8452 provides all the tools one would expect for basic user and administrator
8453 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
8454 the GNU Zile lightweight text editor, @command{find}, @command{grep},
8455 etc. The example above adds GNU@tie{}Screen and OpenSSH to those,
8456 taken from the @code{(gnu packages screen)} and @code{(gnu packages ssh)}
8457 modules (@pxref{Package Modules}). The
8458 @code{(list package output)} syntax can be used to add a specific output
8462 (use-modules (gnu packages))
8463 (use-modules (gnu packages dns))
8467 (packages (cons (list bind "utils")
8471 @findex specification->package
8472 Referring to packages by variable name, like @var{tcpdump} above, has
8473 the advantage of being unambiguous; it also allows typos and such to be
8474 diagnosed right away as ``unbound variables''. The downside is that one
8475 needs to know which module defines which package, and to augment the
8476 @code{use-package-modules} line accordingly. To avoid that, one can use
8477 the @code{specification->package} procedure of the @code{(gnu packages)}
8478 module, which returns the best package for a given name or name and
8482 (use-modules (gnu packages))
8486 (packages (append (map specification->package
8487 '("tcpdump" "htop" "gnupg@@2.0"))
8491 @unnumberedsubsubsec System Services
8494 @vindex %base-services
8495 The @code{services} field lists @dfn{system services} to be made
8496 available when the system starts (@pxref{Services}).
8497 The @code{operating-system} declaration above specifies that, in
8498 addition to the basic services, we want the @command{lshd} secure shell
8499 daemon listening on port 2222 (@pxref{Networking Services,
8500 @code{lsh-service}}). Under the hood,
8501 @code{lsh-service} arranges so that @code{lshd} is started with the
8502 right command-line options, possibly with supporting configuration files
8503 generated as needed (@pxref{Defining Services}).
8505 @cindex customization, of services
8506 @findex modify-services
8507 Occasionally, instead of using the base services as is, you will want to
8508 customize them. To do this, use @code{modify-services} (@pxref{Service
8509 Reference, @code{modify-services}}) to modify the list.
8511 For example, suppose you want to modify @code{guix-daemon} and Mingetty
8512 (the console log-in) in the @var{%base-services} list (@pxref{Base
8513 Services, @code{%base-services}}). To do that, you can write the
8514 following in your operating system declaration:
8517 (define %my-services
8518 ;; My very own list of services.
8519 (modify-services %base-services
8520 (guix-service-type config =>
8523 (use-substitutes? #f)
8524 (extra-options '("--gc-keep-derivations"))))
8525 (mingetty-service-type config =>
8526 (mingetty-configuration
8527 (inherit config)))))
8531 (services %my-services))
8534 This changes the configuration---i.e., the service parameters---of the
8535 @code{guix-service-type} instance, and that of all the
8536 @code{mingetty-service-type} instances in the @var{%base-services} list.
8537 Observe how this is accomplished: first, we arrange for the original
8538 configuration to be bound to the identifier @code{config} in the
8539 @var{body}, and then we write the @var{body} so that it evaluates to the
8540 desired configuration. In particular, notice how we use @code{inherit}
8541 to create a new configuration which has the same values as the old
8542 configuration, but with a few modifications.
8544 @cindex encrypted disk
8545 The configuration for a typical ``desktop'' usage, with an encrypted
8546 root partition, the X11 display
8547 server, GNOME and Xfce (users can choose which of these desktop
8548 environments to use at the log-in screen by pressing @kbd{F1}), network
8549 management, power management, and more, would look like this:
8552 @include os-config-desktop.texi
8556 A graphical UEFI system with a choice of lightweight window managers
8557 instead of full-blown desktop environments would look like this:
8560 @include os-config-lightweight-desktop.texi
8563 This example refers to the @file{/boot/efi} partition by its UUID,
8564 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
8565 as returned by the @command{blkid} command.
8567 @xref{Desktop Services}, for the exact list of services provided by
8568 @var{%desktop-services}. @xref{X.509 Certificates}, for background
8569 information about the @code{nss-certs} package that is used here.
8571 Again, @var{%desktop-services} is just a list of service objects. If
8572 you want to remove services from there, you can do so using the
8573 procedures for list filtering (@pxref{SRFI-1 Filtering and
8574 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
8575 following expression returns a list that contains all the services in
8576 @var{%desktop-services} minus the Avahi service:
8579 (remove (lambda (service)
8580 (eq? (service-kind service) avahi-service-type))
8584 @unnumberedsubsubsec Instantiating the System
8586 Assuming the @code{operating-system} declaration
8587 is stored in the @file{my-system-config.scm}
8588 file, the @command{guix system reconfigure my-system-config.scm} command
8589 instantiates that configuration, and makes it the default GRUB boot
8590 entry (@pxref{Invoking guix system}).
8592 The normal way to change the system configuration is by updating this
8593 file and re-running @command{guix system reconfigure}. One should never
8594 have to touch files in @file{/etc} or to run commands that modify the
8595 system state such as @command{useradd} or @command{grub-install}. In
8596 fact, you must avoid that since that would not only void your warranty
8597 but also prevent you from rolling back to previous versions of your
8598 system, should you ever need to.
8600 @cindex roll-back, of the operating system
8601 Speaking of roll-back, each time you run @command{guix system
8602 reconfigure}, a new @dfn{generation} of the system is created---without
8603 modifying or deleting previous generations. Old system generations get
8604 an entry in the bootloader boot menu, allowing you to boot them in case
8605 something went wrong with the latest generation. Reassuring, no? The
8606 @command{guix system list-generations} command lists the system
8607 generations available on disk. It is also possible to roll back the
8608 system via the commands @command{guix system roll-back} and
8609 @command{guix system switch-generation}.
8611 Although the command @command{guix system reconfigure} will not modify
8612 previous generations, must take care when the current generation is not
8613 the latest (e.g., after invoking @command{guix system roll-back}), since
8614 the operation might overwrite a later generation (@pxref{Invoking guix
8617 @unnumberedsubsubsec The Programming Interface
8619 At the Scheme level, the bulk of an @code{operating-system} declaration
8620 is instantiated with the following monadic procedure (@pxref{The Store
8623 @deffn {Monadic Procedure} operating-system-derivation os
8624 Return a derivation that builds @var{os}, an @code{operating-system}
8625 object (@pxref{Derivations}).
8627 The output of the derivation is a single directory that refers to all
8628 the packages, configuration files, and other supporting files needed to
8629 instantiate @var{os}.
8632 This procedure is provided by the @code{(gnu system)} module. Along
8633 with @code{(gnu services)} (@pxref{Services}), this module contains the
8634 guts of GuixSD. Make sure to visit it!
8637 @node operating-system Reference
8638 @subsection @code{operating-system} Reference
8640 This section summarizes all the options available in
8641 @code{operating-system} declarations (@pxref{Using the Configuration
8644 @deftp {Data Type} operating-system
8645 This is the data type representing an operating system configuration.
8646 By that, we mean all the global system configuration, not per-user
8647 configuration (@pxref{Using the Configuration System}).
8650 @item @code{kernel} (default: @var{linux-libre})
8651 The package object of the operating system kernel to use@footnote{Currently
8652 only the Linux-libre kernel is supported. In the future, it will be
8653 possible to use the GNU@tie{}Hurd.}.
8655 @item @code{kernel-arguments} (default: @code{'()})
8656 List of strings or gexps representing additional arguments to pass on
8657 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
8659 @item @code{bootloader}
8660 The system bootloader configuration object. @xref{Bootloader Configuration}.
8662 @item @code{initrd} (default: @code{base-initrd})
8664 @cindex initial RAM disk
8665 A two-argument monadic procedure that returns an initial RAM disk for
8666 the Linux kernel. @xref{Initial RAM Disk}.
8668 @item @code{firmware} (default: @var{%base-firmware})
8670 List of firmware packages loadable by the operating system kernel.
8672 The default includes firmware needed for Atheros- and Broadcom-based
8673 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
8674 respectively). @xref{Hardware Considerations}, for more info on
8677 @item @code{host-name}
8680 @item @code{hosts-file}
8682 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
8683 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
8684 Reference Manual}). The default is a file with entries for
8685 @code{localhost} and @var{host-name}.
8687 @item @code{mapped-devices} (default: @code{'()})
8688 A list of mapped devices. @xref{Mapped Devices}.
8690 @item @code{file-systems}
8691 A list of file systems. @xref{File Systems}.
8693 @item @code{swap-devices} (default: @code{'()})
8694 @cindex swap devices
8695 A list of strings identifying devices or files to be used for ``swap
8696 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
8697 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
8698 It is possible to specify a swap file in a file system on a mapped
8699 device, provided that the necessary device mapping and file system are
8700 also specified. @xref{Mapped Devices} and @ref{File Systems}.
8702 @item @code{users} (default: @code{%base-user-accounts})
8703 @itemx @code{groups} (default: @var{%base-groups})
8704 List of user accounts and groups. @xref{User Accounts}.
8706 @item @code{skeletons} (default: @code{(default-skeletons)})
8707 A list target file name/file-like object tuples (@pxref{G-Expressions,
8708 file-like objects}). These are the skeleton files that will be added to
8709 the home directory of newly-created user accounts.
8711 For instance, a valid value may look like this:
8714 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
8715 (".guile" ,(plain-file "guile"
8716 "(use-modules (ice-9 readline))
8717 (activate-readline)")))
8720 @item @code{issue} (default: @var{%default-issue})
8721 A string denoting the contents of the @file{/etc/issue} file, which is
8722 displayed when users log in on a text console.
8724 @item @code{packages} (default: @var{%base-packages})
8725 The set of packages installed in the global profile, which is accessible
8726 at @file{/run/current-system/profile}.
8728 The default set includes core utilities and it is good practice to
8729 install non-core utilities in user profiles (@pxref{Invoking guix
8732 @item @code{timezone}
8733 A timezone identifying string---e.g., @code{"Europe/Paris"}.
8735 You can run the @command{tzselect} command to find out which timezone
8736 string corresponds to your region. Choosing an invalid timezone name
8737 causes @command{guix system} to fail.
8739 @item @code{locale} (default: @code{"en_US.utf8"})
8740 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
8741 Library Reference Manual}). @xref{Locales}, for more information.
8743 @item @code{locale-definitions} (default: @var{%default-locale-definitions})
8744 The list of locale definitions to be compiled and that may be used at
8745 run time. @xref{Locales}.
8747 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
8748 The list of GNU@tie{}libc packages whose locale data and tools are used
8749 to build the locale definitions. @xref{Locales}, for compatibility
8750 considerations that justify this option.
8752 @item @code{name-service-switch} (default: @var{%default-nss})
8753 Configuration of the libc name service switch (NSS)---a
8754 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
8757 @item @code{services} (default: @var{%base-services})
8758 A list of service objects denoting system services. @xref{Services}.
8760 @item @code{pam-services} (default: @code{(base-pam-services)})
8762 @cindex pluggable authentication modules
8763 Linux @dfn{pluggable authentication module} (PAM) services.
8764 @c FIXME: Add xref to PAM services section.
8766 @item @code{setuid-programs} (default: @var{%setuid-programs})
8767 List of string-valued G-expressions denoting setuid programs.
8768 @xref{Setuid Programs}.
8770 @item @code{sudoers-file} (default: @var{%sudoers-specification})
8771 @cindex sudoers file
8772 The contents of the @file{/etc/sudoers} file as a file-like object
8773 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
8775 This file specifies which users can use the @command{sudo} command, what
8776 they are allowed to do, and what privileges they may gain. The default
8777 is that only @code{root} and members of the @code{wheel} group may use
8784 @subsection File Systems
8786 The list of file systems to be mounted is specified in the
8787 @code{file-systems} field of the operating system declaration
8788 (@pxref{Using the Configuration System}). Each file system is declared
8789 using the @code{file-system} form, like this:
8793 (mount-point "/home")
8794 (device "/dev/sda3")
8798 As usual, some of the fields are mandatory---those shown in the example
8799 above---while others can be omitted. These are described below.
8801 @deftp {Data Type} file-system
8802 Objects of this type represent file systems to be mounted. They
8803 contain the following members:
8807 This is a string specifying the type of the file system---e.g.,
8810 @item @code{mount-point}
8811 This designates the place where the file system is to be mounted.
8814 This names the ``source'' of the file system. By default it is the name
8815 of a node under @file{/dev}, but its meaning depends on the @code{title}
8816 field described below.
8818 @item @code{title} (default: @code{'device})
8819 This is a symbol that specifies how the @code{device} field is to be
8822 When it is the symbol @code{device}, then the @code{device} field is
8823 interpreted as a file name; when it is @code{label}, then @code{device}
8824 is interpreted as a partition label name; when it is @code{uuid},
8825 @code{device} is interpreted as a partition unique identifier (UUID).
8827 UUIDs may be converted from their string representation (as shown by the
8828 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
8829 @code{uuid} form expects 16-byte UUIDs as defined in
8830 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
8831 form of UUID used by the ext2 family of file systems and others, but it
8832 is different from ``UUIDs'' found in FAT file systems, for instance.},
8837 (mount-point "/home")
8840 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
8843 The @code{label} and @code{uuid} options offer a way to refer to disk
8844 partitions without having to hard-code their actual device
8845 name@footnote{Note that, while it is tempting to use
8846 @file{/dev/disk/by-uuid} and similar device names to achieve the same
8847 result, this is not recommended: These special device nodes are created
8848 by the udev daemon and may be unavailable at the time the device is
8851 However, when the source of a file system is a mapped device (@pxref{Mapped
8852 Devices}), its @code{device} field @emph{must} refer to the mapped
8853 device name---e.g., @file{/dev/mapper/root-partition}---and consequently
8854 @code{title} must be set to @code{'device}. This is required so that
8855 the system knows that mounting the file system depends on having the
8856 corresponding device mapping established.
8858 @item @code{flags} (default: @code{'()})
8859 This is a list of symbols denoting mount flags. Recognized flags
8860 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
8861 access to special files), @code{no-suid} (ignore setuid and setgid
8862 bits), and @code{no-exec} (disallow program execution.)
8864 @item @code{options} (default: @code{#f})
8865 This is either @code{#f}, or a string denoting mount options.
8867 @item @code{mount?} (default: @code{#t})
8868 This value indicates whether to automatically mount the file system when
8869 the system is brought up. When set to @code{#f}, the file system gets
8870 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
8871 is not automatically mounted.
8873 @item @code{needed-for-boot?} (default: @code{#f})
8874 This Boolean value indicates whether the file system is needed when
8875 booting. If that is true, then the file system is mounted when the
8876 initial RAM disk (initrd) is loaded. This is always the case, for
8877 instance, for the root file system.
8879 @item @code{check?} (default: @code{#t})
8880 This Boolean indicates whether the file system needs to be checked for
8881 errors before being mounted.
8883 @item @code{create-mount-point?} (default: @code{#f})
8884 When true, the mount point is created if it does not exist yet.
8886 @item @code{dependencies} (default: @code{'()})
8887 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
8888 representing file systems that must be mounted or mapped devices that
8889 must be opened before (and unmounted or closed after) this one.
8891 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
8892 a dependency of @file{/sys/fs/cgroup/cpu} and
8893 @file{/sys/fs/cgroup/memory}.
8895 Another example is a file system that depends on a mapped device, for
8896 example for an encrypted partition (@pxref{Mapped Devices}).
8900 The @code{(gnu system file-systems)} exports the following useful
8903 @defvr {Scheme Variable} %base-file-systems
8904 These are essential file systems that are required on normal systems,
8905 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
8906 below.) Operating system declarations should always contain at least
8910 @defvr {Scheme Variable} %pseudo-terminal-file-system
8911 This is the file system to be mounted as @file{/dev/pts}. It supports
8912 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
8913 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
8914 Manual}). Pseudo-terminals are used by terminal emulators such as
8918 @defvr {Scheme Variable} %shared-memory-file-system
8919 This file system is mounted as @file{/dev/shm} and is used to support
8920 memory sharing across processes (@pxref{Memory-mapped I/O,
8921 @code{shm_open},, libc, The GNU C Library Reference Manual}).
8924 @defvr {Scheme Variable} %immutable-store
8925 This file system performs a read-only ``bind mount'' of
8926 @file{/gnu/store}, making it read-only for all the users including
8927 @code{root}. This prevents against accidental modification by software
8928 running as @code{root} or by system administrators.
8930 The daemon itself is still able to write to the store: it remounts it
8931 read-write in its own ``name space.''
8934 @defvr {Scheme Variable} %binary-format-file-system
8935 The @code{binfmt_misc} file system, which allows handling of arbitrary
8936 executable file types to be delegated to user space. This requires the
8937 @code{binfmt.ko} kernel module to be loaded.
8940 @defvr {Scheme Variable} %fuse-control-file-system
8941 The @code{fusectl} file system, which allows unprivileged users to mount
8942 and unmount user-space FUSE file systems. This requires the
8943 @code{fuse.ko} kernel module to be loaded.
8946 @node Mapped Devices
8947 @subsection Mapped Devices
8949 @cindex device mapping
8950 @cindex mapped devices
8951 The Linux kernel has a notion of @dfn{device mapping}: a block device,
8952 such as a hard disk partition, can be @dfn{mapped} into another device,
8953 usually in @code{/dev/mapper/},
8954 with additional processing over the data that flows through
8955 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
8956 concept of a ``mapped device'' and that of a file system: both boil down
8957 to @emph{translating} input/output operations made on a file to
8958 operations on its backing store. Thus, the Hurd implements mapped
8959 devices, like file systems, using the generic @dfn{translator} mechanism
8960 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
8961 typical example is encryption device mapping: all writes to the mapped
8962 device are encrypted, and all reads are deciphered, transparently.
8963 Guix extends this notion by considering any device or set of devices that
8964 are @dfn{transformed} in some way to create a new device; for instance,
8965 RAID devices are obtained by @dfn{assembling} several other devices, such
8966 as hard disks or partitions, into a new one that behaves as one partition.
8967 Other examples, not yet implemented, are LVM logical volumes.
8969 Mapped devices are declared using the @code{mapped-device} form,
8970 defined as follows; for examples, see below.
8972 @deftp {Data Type} mapped-device
8973 Objects of this type represent device mappings that will be made when
8974 the system boots up.
8978 This is either a string specifying the name of the block device to be mapped,
8979 such as @code{"/dev/sda3"}, or a list of such strings when several devices
8980 need to be assembled for creating a new one.
8983 This string specifies the name of the resulting mapped device. For
8984 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
8985 specifying @code{"my-partition"} leads to the creation of
8986 the @code{"/dev/mapper/my-partition"} device.
8987 For RAID devices of type @code{raid-device-mapping}, the full device name
8988 such as @code{"/dev/md0"} needs to be given.
8991 This must be a @code{mapped-device-kind} object, which specifies how
8992 @var{source} is mapped to @var{target}.
8996 @defvr {Scheme Variable} luks-device-mapping
8997 This defines LUKS block device encryption using the @command{cryptsetup}
8998 command from the package with the same name. It relies on the
8999 @code{dm-crypt} Linux kernel module.
9002 @defvr {Scheme Variable} raid-device-mapping
9003 This defines a RAID device, which is assembled using the @code{mdadm}
9004 command from the package with the same name. It requires a Linux kernel
9005 module for the appropriate RAID level to be loaded, such as @code{raid456}
9006 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
9009 @cindex disk encryption
9011 The following example specifies a mapping from @file{/dev/sda3} to
9012 @file{/dev/mapper/home} using LUKS---the
9013 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
9014 standard mechanism for disk encryption.
9015 The @file{/dev/mapper/home}
9016 device can then be used as the @code{device} of a @code{file-system}
9017 declaration (@pxref{File Systems}).
9021 (source "/dev/sda3")
9023 (type luks-device-mapping))
9026 Alternatively, to become independent of device numbering, one may obtain
9027 the LUKS UUID (@dfn{unique identifier}) of the source device by a
9031 cryptsetup luksUUID /dev/sda3
9034 and use it as follows:
9038 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
9040 (type luks-device-mapping))
9043 @cindex swap encryption
9044 It is also desirable to encrypt swap space, since swap space may contain
9045 sensitive data. One way to accomplish that is to use a swap file in a
9046 file system on a device mapped via LUKS encryption. In this way, the
9047 swap file is encrypted because the entire device is encrypted.
9048 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
9050 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
9051 may be declared as follows:
9055 (source (list "/dev/sda1" "/dev/sdb1"))
9057 (type raid-device-mapping))
9060 The @file{/dev/md0} device can then be used as the @code{device} of a
9061 @code{file-system} declaration (@pxref{File Systems}).
9062 Note that the RAID level need not be given; it is chosen during the
9063 initial creation and formatting of the RAID device and is determined
9064 automatically later.
9068 @subsection User Accounts
9072 @cindex user accounts
9073 User accounts and groups are entirely managed through the
9074 @code{operating-system} declaration. They are specified with the
9075 @code{user-account} and @code{user-group} forms:
9081 (supplementary-groups '("wheel" ;allow use of sudo, etc.
9083 "video" ;video devices such as webcams
9084 "cdrom")) ;the good ol' CD-ROM
9085 (comment "Bob's sister")
9086 (home-directory "/home/alice"))
9089 When booting or upon completion of @command{guix system reconfigure},
9090 the system ensures that only the user accounts and groups specified in
9091 the @code{operating-system} declaration exist, and with the specified
9092 properties. Thus, account or group creations or modifications made by
9093 directly invoking commands such as @command{useradd} are lost upon
9094 reconfiguration or reboot. This ensures that the system remains exactly
9097 @deftp {Data Type} user-account
9098 Objects of this type represent user accounts. The following members may
9103 The name of the user account.
9107 This is the name (a string) or identifier (a number) of the user group
9108 this account belongs to.
9110 @item @code{supplementary-groups} (default: @code{'()})
9111 Optionally, this can be defined as a list of group names that this
9114 @item @code{uid} (default: @code{#f})
9115 This is the user ID for this account (a number), or @code{#f}. In the
9116 latter case, a number is automatically chosen by the system when the
9119 @item @code{comment} (default: @code{""})
9120 A comment about the account, such as the account owner's full name.
9122 @item @code{home-directory}
9123 This is the name of the home directory for the account.
9125 @item @code{create-home-directory?} (default: @code{#t})
9126 Indicates whether the home directory of this account should be created
9127 if it does not exist yet.
9129 @item @code{shell} (default: Bash)
9130 This is a G-expression denoting the file name of a program to be used as
9131 the shell (@pxref{G-Expressions}).
9133 @item @code{system?} (default: @code{#f})
9134 This Boolean value indicates whether the account is a ``system''
9135 account. System accounts are sometimes treated specially; for instance,
9136 graphical login managers do not list them.
9138 @anchor{user-account-password}
9139 @item @code{password} (default: @code{#f})
9140 You would normally leave this field to @code{#f}, initialize user
9141 passwords as @code{root} with the @command{passwd} command, and then let
9142 users change it with @command{passwd}. Passwords set with
9143 @command{passwd} are of course preserved across reboot and
9146 If you @emph{do} want to have a preset password for an account, then
9147 this field must contain the encrypted password, as a string.
9148 @xref{crypt,,, libc, The GNU C Library Reference Manual}, for more information
9149 on password encryption, and @ref{Encryption,,, guile, GNU Guile Reference
9150 Manual}, for information on Guile's @code{crypt} procedure.
9156 User group declarations are even simpler:
9159 (user-group (name "students"))
9162 @deftp {Data Type} user-group
9163 This type is for, well, user groups. There are just a few fields:
9167 The name of the group.
9169 @item @code{id} (default: @code{#f})
9170 The group identifier (a number). If @code{#f}, a new number is
9171 automatically allocated when the group is created.
9173 @item @code{system?} (default: @code{#f})
9174 This Boolean value indicates whether the group is a ``system'' group.
9175 System groups have low numerical IDs.
9177 @item @code{password} (default: @code{#f})
9178 What, user groups can have a password? Well, apparently yes. Unless
9179 @code{#f}, this field specifies the password of the group.
9184 For convenience, a variable lists all the basic user groups one may
9187 @defvr {Scheme Variable} %base-groups
9188 This is the list of basic user groups that users and/or packages expect
9189 to be present on the system. This includes groups such as ``root'',
9190 ``wheel'', and ``users'', as well as groups used to control access to
9191 specific devices such as ``audio'', ``disk'', and ``cdrom''.
9194 @defvr {Scheme Variable} %base-user-accounts
9195 This is the list of basic system accounts that programs may expect to
9196 find on a GNU/Linux system, such as the ``nobody'' account.
9198 Note that the ``root'' account is not included here. It is a
9199 special-case and is automatically added whether or not it is specified.
9206 A @dfn{locale} defines cultural conventions for a particular language
9207 and region of the world (@pxref{Locales,,, libc, The GNU C Library
9208 Reference Manual}). Each locale has a name that typically has the form
9209 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
9210 @code{fr_LU.utf8} designates the locale for the French language, with
9211 cultural conventions from Luxembourg, and using the UTF-8 encoding.
9213 @cindex locale definition
9214 Usually, you will want to specify the default locale for the machine
9215 using the @code{locale} field of the @code{operating-system} declaration
9216 (@pxref{operating-system Reference, @code{locale}}).
9218 The selected locale is automatically added to the @dfn{locale
9219 definitions} known to the system if needed, with its codeset inferred
9220 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
9221 @code{UTF-8} codeset. Additional locale definitions can be specified in
9222 the @code{locale-definitions} slot of @code{operating-system}---this is
9223 useful, for instance, if the codeset could not be inferred from the
9224 locale name. The default set of locale definitions includes some widely
9225 used locales, but not all the available locales, in order to save space.
9227 For instance, to add the North Frisian locale for Germany, the value of
9231 (cons (locale-definition
9232 (name "fy_DE.utf8") (source "fy_DE"))
9233 %default-locale-definitions)
9236 Likewise, to save space, one might want @code{locale-definitions} to
9237 list only the locales that are actually used, as in:
9240 (list (locale-definition
9241 (name "ja_JP.eucjp") (source "ja_JP")
9242 (charset "EUC-JP")))
9246 The compiled locale definitions are available at
9247 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
9248 version, which is the default location where the GNU@tie{}libc provided
9249 by Guix looks for locale data. This can be overridden using the
9250 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
9251 @code{LOCPATH} and locale packages}).
9253 The @code{locale-definition} form is provided by the @code{(gnu system
9254 locale)} module. Details are given below.
9256 @deftp {Data Type} locale-definition
9257 This is the data type of a locale definition.
9262 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
9263 Reference Manual}, for more information on locale names.
9266 The name of the source for that locale. This is typically the
9267 @code{@var{language}_@var{territory}} part of the locale name.
9269 @item @code{charset} (default: @code{"UTF-8"})
9270 The ``character set'' or ``code set'' for that locale,
9271 @uref{http://www.iana.org/assignments/character-sets, as defined by
9277 @defvr {Scheme Variable} %default-locale-definitions
9278 A list of commonly used UTF-8 locales, used as the default
9279 value of the @code{locale-definitions} field of @code{operating-system}
9283 @cindex normalized codeset in locale names
9284 These locale definitions use the @dfn{normalized codeset} for the part
9285 that follows the dot in the name (@pxref{Using gettextized software,
9286 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
9287 instance it has @code{uk_UA.utf8} but @emph{not}, say,
9291 @subsubsection Locale Data Compatibility Considerations
9293 @cindex incompatibility, of locale data
9294 @code{operating-system} declarations provide a @code{locale-libcs} field
9295 to specify the GNU@tie{}libc packages that are used to compile locale
9296 declarations (@pxref{operating-system Reference}). ``Why would I
9297 care?'', you may ask. Well, it turns out that the binary format of
9298 locale data is occasionally incompatible from one libc version to
9301 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
9302 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
9303 For instance, a program linked against libc version 2.21 is unable to
9304 read locale data produced with libc 2.22; worse, that program
9305 @emph{aborts} instead of simply ignoring the incompatible locale
9306 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
9307 the incompatible locale data, which is already an improvement.}.
9308 Similarly, a program linked against libc 2.22 can read most, but not
9309 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
9310 data is incompatible); thus calls to @code{setlocale} may fail, but
9311 programs will not abort.
9313 The ``problem'' in GuixSD is that users have a lot of freedom: They can
9314 choose whether and when to upgrade software in their profiles, and might
9315 be using a libc version different from the one the system administrator
9316 used to build the system-wide locale data.
9318 Fortunately, unprivileged users can also install their own locale data
9319 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
9320 @code{GUIX_LOCPATH} and locale packages}).
9322 Still, it is best if the system-wide locale data at
9323 @file{/run/current-system/locale} is built for all the libc versions
9324 actually in use on the system, so that all the programs can access
9325 it---this is especially crucial on a multi-user system. To do that, the
9326 administrator can specify several libc packages in the
9327 @code{locale-libcs} field of @code{operating-system}:
9330 (use-package-modules base)
9334 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
9337 This example would lead to a system containing locale definitions for
9338 both libc 2.21 and the current version of libc in
9339 @file{/run/current-system/locale}.
9343 @subsection Services
9345 @cindex system services
9346 An important part of preparing an @code{operating-system} declaration is
9347 listing @dfn{system services} and their configuration (@pxref{Using the
9348 Configuration System}). System services are typically daemons launched
9349 when the system boots, or other actions needed at that time---e.g.,
9350 configuring network access.
9352 GuixSD has a broad definition of ``service'' (@pxref{Service
9353 Composition}), but many services are managed by the GNU@tie{}Shepherd
9354 (@pxref{Shepherd Services}). On a running system, the @command{herd}
9355 command allows you to list the available services, show their status,
9356 start and stop them, or do other specific operations (@pxref{Jump
9357 Start,,, shepherd, The GNU Shepherd Manual}). For example:
9363 The above command, run as @code{root}, lists the currently defined
9364 services. The @command{herd doc} command shows a synopsis of the given
9369 Run libc's name service cache daemon (nscd).
9372 The @command{start}, @command{stop}, and @command{restart} sub-commands
9373 have the effect you would expect. For instance, the commands below stop
9374 the nscd service and restart the Xorg display server:
9378 Service nscd has been stopped.
9379 # herd restart xorg-server
9380 Service xorg-server has been stopped.
9381 Service xorg-server has been started.
9384 The following sections document the available services, starting with
9385 the core services, that may be used in an @code{operating-system}
9389 * Base Services:: Essential system services.
9390 * Scheduled Job Execution:: The mcron service.
9391 * Log Rotation:: The rottlog service.
9392 * Networking Services:: Network setup, SSH daemon, etc.
9393 * X Window:: Graphical display.
9394 * Printing Services:: Local and remote printer support.
9395 * Desktop Services:: D-Bus and desktop services.
9396 * Database Services:: SQL databases, key-value stores, etc.
9397 * Mail Services:: IMAP, POP3, SMTP, and all that.
9398 * Messaging Services:: Messaging services.
9399 * Telephony Services:: Telephony services.
9400 * Monitoring Services:: Monitoring services.
9401 * Kerberos Services:: Kerberos services.
9402 * Web Services:: Web servers.
9403 * Certificate Services:: TLS certificates via Let's Encrypt.
9404 * DNS Services:: DNS daemons.
9405 * VPN Services:: VPN daemons.
9406 * Network File System:: NFS related services.
9407 * Continuous Integration:: The Cuirass service.
9408 * Power management Services:: The TLP tool.
9409 * Audio Services:: The MPD.
9410 * Virtualization Services:: Virtualization services.
9411 * Version Control Services:: Providing remote access to Git repositories.
9412 * Miscellaneous Services:: Other services.
9416 @subsubsection Base Services
9418 The @code{(gnu services base)} module provides definitions for the basic
9419 services that one expects from the system. The services exported by
9420 this module are listed below.
9422 @defvr {Scheme Variable} %base-services
9423 This variable contains a list of basic services (@pxref{Service Types
9424 and Services}, for more information on service objects) one would
9425 expect from the system: a login service (mingetty) on each tty, syslogd,
9426 the libc name service cache daemon (nscd), the udev device manager, and
9429 This is the default value of the @code{services} field of
9430 @code{operating-system} declarations. Usually, when customizing a
9431 system, you will want to append services to @var{%base-services}, like
9435 (cons* (avahi-service) (lsh-service) %base-services)
9439 @defvr {Scheme Variable} special-files-service-type
9440 This is the service that sets up ``special files'' such as
9441 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
9443 The value associated with @code{special-files-service-type} services
9444 must be a list of tuples where the first element is the ``special file''
9445 and the second element is its target. By default it is:
9447 @cindex @file{/bin/sh}
9448 @cindex @file{sh}, in @file{/bin}
9450 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
9453 @cindex @file{/usr/bin/env}
9454 @cindex @file{env}, in @file{/usr/bin}
9455 If you want to add, say, @code{/usr/bin/env} to your system, you can
9459 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
9460 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
9463 Since this is part of @code{%base-services}, you can use
9464 @code{modify-services} to customize the set of special files
9465 (@pxref{Service Reference, @code{modify-services}}). But the simple way
9466 to add a special file is @i{via} the @code{extra-special-file} procedure
9470 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
9471 Use @var{target} as the ``special file'' @var{file}.
9473 For example, adding the following lines to the @code{services} field of
9474 your operating system declaration leads to a @file{/usr/bin/env}
9478 (extra-special-file "/usr/bin/env"
9479 (file-append coreutils "/bin/env"))
9483 @deffn {Scheme Procedure} host-name-service @var{name}
9484 Return a service that sets the host name to @var{name}.
9487 @deffn {Scheme Procedure} login-service @var{config}
9488 Return a service to run login according to @var{config}, a
9489 @code{<login-configuration>} object, which specifies the message of the day,
9493 @deftp {Data Type} login-configuration
9494 This is the data type representing the configuration of login.
9499 @cindex message of the day
9500 A file-like object containing the ``message of the day''.
9502 @item @code{allow-empty-passwords?} (default: @code{#t})
9503 Allow empty passwords by default so that first-time users can log in when
9504 the 'root' account has just been created.
9509 @deffn {Scheme Procedure} mingetty-service @var{config}
9510 Return a service to run mingetty according to @var{config}, a
9511 @code{<mingetty-configuration>} object, which specifies the tty to run, among
9515 @deftp {Data Type} mingetty-configuration
9516 This is the data type representing the configuration of Mingetty, which
9517 provides the default implementation of virtual console log-in.
9522 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
9524 @item @code{auto-login} (default: @code{#f})
9525 When true, this field must be a string denoting the user name under
9526 which the system automatically logs in. When it is @code{#f}, a
9527 user name and password must be entered to log in.
9529 @item @code{login-program} (default: @code{#f})
9530 This must be either @code{#f}, in which case the default log-in program
9531 is used (@command{login} from the Shadow tool suite), or a gexp denoting
9532 the name of the log-in program.
9534 @item @code{login-pause?} (default: @code{#f})
9535 When set to @code{#t} in conjunction with @var{auto-login}, the user
9536 will have to press a key before the log-in shell is launched.
9538 @item @code{mingetty} (default: @var{mingetty})
9539 The Mingetty package to use.
9544 @deffn {Scheme Procedure} agetty-service @var{config}
9545 Return a service to run agetty according to @var{config}, an
9546 @code{<agetty-configuration>} object, which specifies the tty to run,
9550 @deftp {Data Type} agetty-configuration
9551 This is the data type representing the configuration of agetty, which
9552 implements virtual and serial console log-in. See the @code{agetty(8)}
9553 man page for more information.
9558 The name of the console this agetty runs on, as a string---e.g.,
9559 @code{"ttyS0"}. This argument is mandatory.
9561 @item @code{baud-rate} (default: @code{#f})
9562 A string containing a comma-separated list of one or more baud rates, in
9565 @item @code{term} (default: @code{#f})
9566 A string containing the value used for the @code{TERM} environment
9569 @item @code{eight-bits?} (default: @code{#f})
9570 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
9573 @item @code{auto-login} (default: @code{#f})
9574 When passed a login name, as a string, the specified user will be logged
9575 in automatically without prompting for their login name or password.
9577 @item @code{no-reset?} (default: @code{#f})
9578 When @code{#t}, don't reset terminal cflags (control modes).
9580 @item @code{host} (default: @code{#f})
9581 This accepts a string containing the "login_host", which will be written
9582 into the @file{/var/run/utmpx} file.
9584 @item @code{remote?} (default: @code{#f})
9585 When set to @code{#t} in conjunction with @var{host}, this will add an
9586 @code{-r} fakehost option to the command line of the login program
9587 specified in @var{login-program}.
9589 @item @code{flow-control?} (default: @code{#f})
9590 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
9592 @item @code{no-issue?} (default: @code{#f})
9593 When set to @code{#t}, the contents of the @file{/etc/issue} file will
9594 not be displayed before presenting the login prompt.
9596 @item @code{init-string} (default: @code{#f})
9597 This accepts a string that will be sent to the tty or modem before
9598 sending anything else. It can be used to initialize a modem.
9600 @item @code{no-clear?} (default: @code{#f})
9601 When set to @code{#t}, agetty will not clear the screen before showing
9604 @item @code{login-program} (default: (file-append shadow "/bin/login"))
9605 This must be either a gexp denoting the name of a log-in program, or
9606 unset, in which case the default value is the @command{login} from the
9609 @item @code{local-line} (default: @code{#f})
9610 Control the CLOCAL line flag. This accepts one of three symbols as
9611 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
9612 the default value chosen by agetty is @code{'auto}.
9614 @item @code{extract-baud?} (default: @code{#f})
9615 When set to @code{#t}, instruct agetty to try to extract the baud rate
9616 from the status messages produced by certain types of modems.
9618 @item @code{skip-login?} (default: @code{#f})
9619 When set to @code{#t}, do not prompt the user for a login name. This
9620 can be used with @var{login-program} field to use non-standard login
9623 @item @code{no-newline?} (default: @code{#f})
9624 When set to @code{#t}, do not print a newline before printing the
9625 @file{/etc/issue} file.
9627 @c Is this dangerous only when used with login-program, or always?
9628 @item @code{login-options} (default: @code{#f})
9629 This option accepts a string containing options that are passed to the
9630 login program. When used with the @var{login-program}, be aware that a
9631 malicious user could try to enter a login name containing embedded
9632 options that could be parsed by the login program.
9634 @item @code{login-pause} (default: @code{#f})
9635 When set to @code{#t}, wait for any key before showing the login prompt.
9636 This can be used in conjunction with @var{auto-login} to save memory by
9637 lazily spawning shells.
9639 @item @code{chroot} (default: @code{#f})
9640 Change root to the specified directory. This option accepts a directory
9643 @item @code{hangup?} (default: @code{#f})
9644 Use the Linux system call @code{vhangup} to do a virtual hangup of the
9647 @item @code{keep-baud?} (default: @code{#f})
9648 When set to @code{#t}, try to keep the existing baud rate. The baud
9649 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
9652 @item @code{timeout} (default: @code{#f})
9653 When set to an integer value, terminate if no user name could be read
9654 within @var{timeout} seconds.
9656 @item @code{detect-case?} (default: @code{#f})
9657 When set to @code{#t}, turn on support for detecting an uppercase-only
9658 terminal. This setting will detect a login name containing only
9659 uppercase letters as indicating an uppercase-only terminal and turn on
9660 some upper-to-lower case conversions. Note that this will not support
9663 @item @code{wait-cr?} (default: @code{#f})
9664 When set to @code{#t}, wait for the user or modem to send a
9665 carriage-return or linefeed character before displaying
9666 @file{/etc/issue} or login prompt. This is typically used with the
9667 @var{init-string} option.
9669 @item @code{no-hints?} (default: @code{#f})
9670 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
9673 @item @code{no-hostname?} (default: @code{#f})
9674 By default, the hostname is printed. When this option is set to
9675 @code{#t}, no hostname will be shown at all.
9677 @item @code{long-hostname?} (default: @code{#f})
9678 By default, the hostname is only printed until the first dot. When this
9679 option is set to @code{#t}, the fully qualified hostname by
9680 @code{gethostname} or @code{getaddrinfo} is shown.
9682 @item @code{erase-characters} (default: @code{#f})
9683 This option accepts a string of additional characters that should be
9684 interpreted as backspace when the user types their login name.
9686 @item @code{kill-characters} (default: @code{#f})
9687 This option accepts a string that should be interpreted to mean "ignore
9688 all previous characters" (also called a "kill" character) when the types
9691 @item @code{chdir} (default: @code{#f})
9692 This option accepts, as a string, a directory path that will be changed
9695 @item @code{delay} (default: @code{#f})
9696 This options accepts, as an integer, the number of seconds to sleep
9697 before opening the tty and displaying the login prompt.
9699 @item @code{nice} (default: @code{#f})
9700 This option accepts, as an integer, the nice value with which to run the
9701 @command{login} program.
9703 @item @code{extra-options} (default: @code{'()})
9704 This option provides an "escape hatch" for the user to provide arbitrary
9705 command-line arguments to @command{agetty} as a list of strings.
9710 @deffn {Scheme Procedure} kmscon-service-type @var{config}
9711 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
9712 according to @var{config}, a @code{<kmscon-configuration>} object, which
9713 specifies the tty to run, among other things.
9716 @deftp {Data Type} kmscon-configuration
9717 This is the data type representing the configuration of Kmscon, which
9718 implements virtual console log-in.
9722 @item @code{virtual-terminal}
9723 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
9725 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
9726 A gexp denoting the name of the log-in program. The default log-in program is
9727 @command{login} from the Shadow tool suite.
9729 @item @code{login-arguments} (default: @code{'("-p")})
9730 A list of arguments to pass to @command{login}.
9732 @item @code{hardware-acceleration?} (default: #f)
9733 Whether to use hardware acceleration.
9735 @item @code{kmscon} (default: @var{kmscon})
9736 The Kmscon package to use.
9741 @cindex name service cache daemon
9743 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
9744 [#:name-services '()]
9745 Return a service that runs the libc name service cache daemon (nscd) with the
9746 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
9747 Service Switch}, for an example.
9750 @defvr {Scheme Variable} %nscd-default-configuration
9751 This is the default @code{<nscd-configuration>} value (see below) used
9752 by @code{nscd-service}. It uses the caches defined by
9753 @var{%nscd-default-caches}; see below.
9756 @deftp {Data Type} nscd-configuration
9757 This is the data type representing the name service cache daemon (nscd)
9762 @item @code{name-services} (default: @code{'()})
9763 List of packages denoting @dfn{name services} that must be visible to
9764 the nscd---e.g., @code{(list @var{nss-mdns})}.
9766 @item @code{glibc} (default: @var{glibc})
9767 Package object denoting the GNU C Library providing the @command{nscd}
9770 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
9771 Name of the nscd log file. This is where debugging output goes when
9772 @code{debug-level} is strictly positive.
9774 @item @code{debug-level} (default: @code{0})
9775 Integer denoting the debugging levels. Higher numbers mean that more
9776 debugging output is logged.
9778 @item @code{caches} (default: @var{%nscd-default-caches})
9779 List of @code{<nscd-cache>} objects denoting things to be cached; see
9785 @deftp {Data Type} nscd-cache
9786 Data type representing a cache database of nscd and its parameters.
9790 @item @code{database}
9791 This is a symbol representing the name of the database to be cached.
9792 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
9793 @code{services}, which designate the corresponding NSS database
9794 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
9796 @item @code{positive-time-to-live}
9797 @itemx @code{negative-time-to-live} (default: @code{20})
9798 A number representing the number of seconds during which a positive or
9799 negative lookup result remains in cache.
9801 @item @code{check-files?} (default: @code{#t})
9802 Whether to check for updates of the files corresponding to
9805 For instance, when @var{database} is @code{hosts}, setting this flag
9806 instructs nscd to check for updates in @file{/etc/hosts} and to take
9809 @item @code{persistent?} (default: @code{#t})
9810 Whether the cache should be stored persistently on disk.
9812 @item @code{shared?} (default: @code{#t})
9813 Whether the cache should be shared among users.
9815 @item @code{max-database-size} (default: 32@tie{}MiB)
9816 Maximum size in bytes of the database cache.
9818 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
9819 @c settings, so leave them out.
9824 @defvr {Scheme Variable} %nscd-default-caches
9825 List of @code{<nscd-cache>} objects used by default by
9826 @code{nscd-configuration} (see above).
9828 It enables persistent and aggressive caching of service and host name
9829 lookups. The latter provides better host name lookup performance,
9830 resilience in the face of unreliable name servers, and also better
9831 privacy---often the result of host name lookups is in local cache, so
9832 external name servers do not even need to be queried.
9835 @anchor{syslog-configuration-type}
9838 @deftp {Data Type} syslog-configuration
9839 This data type represents the configuration of the syslog daemon.
9842 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
9843 The syslog daemon to use.
9845 @item @code{config-file} (default: @code{%default-syslog.conf})
9846 The syslog configuration file to use.
9851 @anchor{syslog-service}
9853 @deffn {Scheme Procedure} syslog-service @var{config}
9854 Return a service that runs a syslog daemon according to @var{config}.
9856 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
9857 information on the configuration file syntax.
9860 @anchor{guix-configuration-type}
9861 @deftp {Data Type} guix-configuration
9862 This data type represents the configuration of the Guix build daemon.
9863 @xref{Invoking guix-daemon}, for more information.
9866 @item @code{guix} (default: @var{guix})
9867 The Guix package to use.
9869 @item @code{build-group} (default: @code{"guixbuild"})
9870 Name of the group for build user accounts.
9872 @item @code{build-accounts} (default: @code{10})
9873 Number of build user accounts to create.
9875 @item @code{authorize-key?} (default: @code{#t})
9876 @cindex substitutes, authorization thereof
9877 Whether to authorize the substitute keys listed in
9878 @code{authorized-keys}---by default that of @code{hydra.gnu.org}
9879 (@pxref{Substitutes}).
9881 @vindex %default-authorized-guix-keys
9882 @item @code{authorized-keys} (default: @var{%default-authorized-guix-keys})
9883 The list of authorized key files for archive imports, as a list of
9884 string-valued gexps (@pxref{Invoking guix archive}). By default, it
9885 contains that of @code{hydra.gnu.org} (@pxref{Substitutes}).
9887 @item @code{use-substitutes?} (default: @code{#t})
9888 Whether to use substitutes.
9890 @item @code{substitute-urls} (default: @var{%default-substitute-urls})
9891 The list of URLs where to look for substitutes by default.
9893 @item @code{max-silent-time} (default: @code{0})
9894 @itemx @code{timeout} (default: @code{0})
9895 The number of seconds of silence and the number of seconds of activity,
9896 respectively, after which a build process times out. A value of zero
9897 disables the timeout.
9899 @item @code{extra-options} (default: @code{'()})
9900 List of extra command-line options for @command{guix-daemon}.
9902 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
9903 File where @command{guix-daemon}'s standard output and standard error
9906 @item @code{http-proxy} (default: @code{#f})
9907 The HTTP proxy used for downloading fixed-output derivations and
9910 @item @code{tmpdir} (default: @code{#f})
9911 A directory path where the @command{guix-daemon} will perform builds.
9916 @deffn {Scheme Procedure} guix-service @var{config}
9917 Return a service that runs the Guix build daemon according to
9921 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
9922 Run @var{udev}, which populates the @file{/dev} directory dynamically.
9923 udev rules can be provided as a list of files through the @var{rules}
9924 variable. The procedures @var{udev-rule} and @var{file->udev-rule} from
9925 @code{(gnu services base)} simplify the creation of such rule files.
9927 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
9928 Return a udev-rule file named @var{file-name} containing the rules
9929 defined by the @var{contents} literal.
9931 In the following example, a rule for a USB device is defined to be
9932 stored in the file @file{90-usb-thing.rules}. The rule runs a script
9933 upon detecting a USB device with a given product identifier.
9936 (define %example-udev-rule
9938 "90-usb-thing.rules"
9939 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
9940 "ATTR@{product@}==\"Example\", "
9941 "RUN+=\"/path/to/script\"")))
9945 Here we show how the default @var{udev-service} can be extended with it.
9951 (modify-services %desktop-services
9952 (udev-service-type config =>
9953 (udev-configuration (inherit config)
9954 (rules (append (udev-configuration-rules config)
9955 (list %example-udev-rule))))))))
9958 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
9959 Return a udev file named @var{file-name} containing the rules defined
9960 within @var{file}, a file-like object.
9962 The following example showcases how we can use an existing rule file.
9965 (use-modules (guix download) ;for url-fetch
9966 (guix packages) ;for origin
9969 (define %android-udev-rules
9971 "51-android-udev.rules"
9972 (let ((version "20170910"))
9975 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
9976 "android-udev-rules/" version "/51-android.rules"))
9978 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
9982 Additionally, Guix package definitions can be included in @var{rules} in
9983 order to extend the udev rules with the definitions found under their
9984 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
9985 @var{file->udev-rule} example, we could have used the
9986 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
9987 packages android)} module.
9989 The following example shows how to use the @var{android-udev-rules}
9990 package so that the Android tool @command{adb} can detect devices
9991 without root privileges. It also details how to create the
9992 @code{adbusers} group, which is required for the proper functioning of
9993 the rules defined within the @var{android-udev-rules} package. To
9994 create such a group, we must define it both as part of the
9995 @var{supplementary-groups} of our @var{user-account} declaration, as
9996 well as in the @var{groups} field of the @var{operating-system} record.
9999 (use-modules (gnu packages android) ;for android-udev-rules
10000 (gnu system shadow) ;for user-group
10005 (users (cons (user-acount
10007 (supplementary-groups
10008 '("adbusers" ;for adb
10009 "wheel" "netdev" "audio" "video"))
10012 (groups (cons (user-group (system? #t) (name "adbusers"))
10018 (modify-services %desktop-services
10019 (udev-service-type config =>
10020 (udev-configuration (inherit config)
10021 (rules (cons* android-udev-rules
10022 (udev-configuration-rules config))))))))
10026 @deffn {Scheme Procedure} urandom-seed-service
10027 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
10031 @defvr {Scheme Variable} %random-seed-file
10032 This is the name of the file where some random bytes are saved by
10033 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
10034 It defaults to @file{/var/lib/random-seed}.
10039 @deffn {Scheme Procedure} console-keymap-service @var{files} ...
10040 @cindex keyboard layout
10041 Return a service to load console keymaps from @var{files} using
10042 @command{loadkeys} command. Most likely, you want to load some default
10043 keymap, which can be done like this:
10046 (console-keymap-service "dvorak")
10049 Or, for example, for a Swedish keyboard, you may need to combine
10050 the following keymaps:
10052 (console-keymap-service "se-lat6" "se-fi-lat6")
10055 Also you can specify a full file name (or file names) of your keymap(s).
10056 See @code{man loadkeys} for details.
10062 @deffn {Scheme Procedure} gpm-service [#:gpm @var{gpm}] @
10064 Run @var{gpm}, the general-purpose mouse daemon, with the given
10065 command-line @var{options}. GPM allows users to use the mouse in the console,
10066 notably to select, copy, and paste text. The default value of @var{options}
10067 uses the @code{ps2} protocol, which works for both USB and PS/2 mice.
10069 This service is not part of @var{%base-services}.
10072 @anchor{guix-publish-service-type}
10073 @deffn {Scheme Variable} guix-publish-service-type
10074 This is the service type for @command{guix publish} (@pxref{Invoking
10075 guix publish}). Its value must be a @code{guix-configuration}
10076 object, as described below.
10078 This assumes that @file{/etc/guix} already contains a signing key pair as
10079 created by @command{guix archive --generate-key} (@pxref{Invoking guix
10080 archive}). If that is not the case, the service will fail to start.
10083 @deftp {Data Type} guix-publish-configuration
10084 Data type representing the configuration of the @code{guix publish}
10088 @item @code{guix} (default: @code{guix})
10089 The Guix package to use.
10091 @item @code{port} (default: @code{80})
10092 The TCP port to listen for connections.
10094 @item @code{host} (default: @code{"localhost"})
10095 The host (and thus, network interface) to listen to. Use
10096 @code{"0.0.0.0"} to listen on all the network interfaces.
10098 @item @code{compression-level} (default: @code{3})
10099 The gzip compression level at which substitutes are compressed. Use
10100 @code{0} to disable compression altogether, and @code{9} to get the best
10101 compression ratio at the expense of increased CPU usage.
10103 @item @code{nar-path} (default: @code{"nar"})
10104 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
10105 publish, @code{--nar-path}}, for details.
10107 @item @code{cache} (default: @code{#f})
10108 When it is @code{#f}, disable caching and instead generate archives on
10109 demand. Otherwise, this should be the name of a directory---e.g.,
10110 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
10111 archives and meta-data ready to be sent. @xref{Invoking guix publish,
10112 @option{--cache}}, for more information on the tradeoffs involved.
10114 @item @code{workers} (default: @code{#f})
10115 When it is an integer, this is the number of worker threads used for
10116 caching; when @code{#f}, the number of processors is used.
10117 @xref{Invoking guix publish, @option{--workers}}, for more information.
10119 @item @code{ttl} (default: @code{#f})
10120 When it is an integer, this denotes the @dfn{time-to-live} of the
10121 published archives. @xref{Invoking guix publish, @option{--ttl}}, for
10126 @anchor{rngd-service}
10127 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
10128 [#:device "/dev/hwrng"]
10129 Return a service that runs the @command{rngd} program from @var{rng-tools}
10130 to add @var{device} to the kernel's entropy pool. The service will fail if
10131 @var{device} does not exist.
10134 @anchor{pam-limits-service}
10135 @cindex session limits
10138 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
10140 Return a service that installs a configuration file for the
10141 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
10142 @code{pam_limits} module}. The procedure optionally takes a list of
10143 @code{pam-limits-entry} values, which can be used to specify
10144 @code{ulimit} limits and nice priority limits to user sessions.
10146 The following limits definition sets two hard and soft limits for all
10147 login sessions of users in the @code{realtime} group:
10150 (pam-limits-service
10152 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
10153 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
10156 The first entry increases the maximum realtime priority for
10157 non-privileged processes; the second entry lifts any restriction of the
10158 maximum address space that can be locked in memory. These settings are
10159 commonly used for real-time audio systems.
10162 @node Scheduled Job Execution
10163 @subsubsection Scheduled Job Execution
10167 @cindex scheduling jobs
10168 The @code{(gnu services mcron)} module provides an interface to
10169 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
10170 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
10171 Unix @command{cron} daemon; the main difference is that it is
10172 implemented in Guile Scheme, which provides a lot of flexibility when
10173 specifying the scheduling of jobs and their actions.
10175 The example below defines an operating system that runs the
10176 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
10177 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
10178 well as the @command{mkid} command on behalf of an unprivileged user
10179 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
10180 gexps to introduce job definitions that are passed to mcron
10181 (@pxref{G-Expressions}).
10184 (use-modules (guix) (gnu) (gnu services mcron))
10185 (use-package-modules base idutils)
10187 (define updatedb-job
10188 ;; Run 'updatedb' at 3AM every day. Here we write the
10189 ;; job's action as a Scheme procedure.
10190 #~(job '(next-hour '(3))
10192 (execl (string-append #$findutils "/bin/updatedb")
10194 "--prunepaths=/tmp /var/tmp /gnu/store"))))
10196 (define garbage-collector-job
10197 ;; Collect garbage 5 minutes after midnight every day.
10198 ;; The job's action is a shell command.
10199 #~(job "5 0 * * *" ;Vixie cron syntax
10202 (define idutils-job
10203 ;; Update the index database as user "charlie" at 12:15PM
10204 ;; and 19:15PM. This runs from the user's home directory.
10205 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
10206 (string-append #$idutils "/bin/mkid src")
10211 (services (cons (mcron-service (list garbage-collector-job
10217 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
10218 for more information on mcron job specifications. Below is the
10219 reference of the mcron service.
10221 @deffn {Scheme Procedure} mcron-service @var{jobs} [#:mcron @var{mcron2}]
10222 Return an mcron service running @var{mcron} that schedules @var{jobs}, a
10223 list of gexps denoting mcron job specifications.
10225 This is a shorthand for:
10227 (service mcron-service-type
10228 (mcron-configuration (mcron mcron) (jobs jobs)))
10232 @defvr {Scheme Variable} mcron-service-type
10233 This is the type of the @code{mcron} service, whose value is an
10234 @code{mcron-configuration} object.
10236 This service type can be the target of a service extension that provides
10237 it additional job specifications (@pxref{Service Composition}). In
10238 other words, it is possible to define services that provide additional
10242 @deftp {Data Type} mcron-configuration
10243 Data type representing the configuration of mcron.
10246 @item @code{mcron} (default: @var{mcron2})
10247 The mcron package to use.
10250 This is a list of gexps (@pxref{G-Expressions}), where each gexp
10251 corresponds to an mcron job specification (@pxref{Syntax, mcron job
10252 specifications,, mcron, GNU@tie{}mcron}).
10258 @subsubsection Log Rotation
10261 @cindex log rotation
10263 Log files such as those found in @file{/var/log} tend to grow endlessly,
10264 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
10265 their contents in separate files, possibly compressed. The @code{(gnu
10266 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
10267 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
10269 The example below defines an operating system that provides log rotation
10270 with the default settings, for commonly encountered log files.
10273 (use-modules (guix) (gnu))
10274 (use-service-modules admin mcron)
10275 (use-package-modules base idutils)
10279 (services (cons* (service mcron-service-type)
10280 (service rottlog-service-type)
10284 @defvr {Scheme Variable} rottlog-service-type
10285 This is the type of the Rottlog service, whose value is a
10286 @code{rottlog-configuration} object.
10288 Other services can extend this one with new @code{log-rotation} objects
10289 (see below), thereby augmenting the set of files to be rotated.
10291 This service type can define mcron jobs (@pxref{Scheduled Job
10292 Execution}) to run the rottlog service.
10295 @deftp {Data Type} rottlog-configuration
10296 Data type representing the configuration of rottlog.
10299 @item @code{rottlog} (default: @code{rottlog})
10300 The Rottlog package to use.
10302 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
10303 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
10304 rottlog, GNU Rot[t]log Manual}).
10306 @item @code{rotations} (default: @code{%default-rotations})
10307 A list of @code{log-rotation} objects as defined below.
10310 This is a list of gexps where each gexp corresponds to an mcron job
10311 specification (@pxref{Scheduled Job Execution}).
10315 @deftp {Data Type} log-rotation
10316 Data type representing the rotation of a group of log files.
10318 Taking an example from the Rottlog manual (@pxref{Period Related File
10319 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
10325 (files '("/var/log/apache/*"))
10326 (options '("storedir apache-archives"
10332 The list of fields is as follows:
10335 @item @code{frequency} (default: @code{'weekly})
10336 The log rotation frequency, a symbol.
10339 The list of files or file glob patterns to rotate.
10341 @item @code{options} (default: @code{'()})
10342 The list of rottlog options for this rotation (@pxref{Configuration
10343 parameters,,, rottlog, GNU Rot[t]lg Manual}).
10345 @item @code{post-rotate} (default: @code{#f})
10346 Either @code{#f} or a gexp to execute once the rotation has completed.
10350 @defvr {Scheme Variable} %default-rotations
10351 Specifies weekly rotation of @var{%rotated-files} and
10352 a couple of other files.
10355 @defvr {Scheme Variable} %rotated-files
10356 The list of syslog-controlled files to be rotated. By default it is:
10357 @code{'("/var/log/messages" "/var/log/secure")}.
10360 @node Networking Services
10361 @subsubsection Networking Services
10363 The @code{(gnu services networking)} module provides services to configure
10364 the network interface.
10366 @cindex DHCP, networking service
10367 @deffn {Scheme Procedure} dhcp-client-service [#:dhcp @var{isc-dhcp}]
10368 Return a service that runs @var{dhcp}, a Dynamic Host Configuration
10369 Protocol (DHCP) client, on all the non-loopback network interfaces.
10372 @defvr {Scheme Variable} static-networking-service-type
10373 This is the type for statically-configured network interfaces.
10374 @c TODO Document <static-networking> data structures.
10377 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
10378 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}]
10379 Return a service that starts @var{interface} with address @var{ip}. If
10380 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
10381 it must be a string specifying the default network gateway.
10383 This procedure can be called several times, one for each network
10384 interface of interest. Behind the scenes what it does is extend
10385 @code{static-networking-service-type} with additional network interfaces
10392 @cindex network management
10393 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
10394 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
10395 management daemon that aims to simplify wired and wireless networking.
10397 This service adds the @var{wicd} package to the global profile, providing
10398 several commands to interact with the daemon and configure networking:
10399 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
10400 and @command{wicd-curses} user interfaces.
10403 @cindex NetworkManager
10405 @defvr {Scheme Variable} network-manager-service-type
10406 This is the service type for the
10407 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
10408 service. The value for this service type is a
10409 @code{network-manager-configuration} record.
10411 This service is part of @code{%desktop-services} (@pxref{Desktop
10415 @deftp {Data Type} network-manager-configuration
10416 Data type representing the configuration of NetworkManager.
10419 @item @code{network-manager} (default: @code{network-manager})
10420 The NetworkManager package to use.
10422 @item @code{dns} (default: @code{"default"})
10423 Processing mode for DNS, which affects how NetworkManager uses the
10424 @code{resolv.conf} configuration file.
10428 NetworkManager will update @code{resolv.conf} to reflect the nameservers
10429 provided by currently active connections.
10432 NetworkManager will run @code{dnsmasq} as a local caching nameserver,
10433 using a "split DNS" configuration if you are connected to a VPN, and
10434 then update @code{resolv.conf} to point to the local nameserver.
10437 NetworkManager will not modify @code{resolv.conf}.
10440 @item @code{vpn-plugins} (default: @code{'()})
10441 This is the list of available plugins for virtual private networks
10442 (VPNs). An example of this is the @code{network-manager-openvpn}
10443 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
10449 @deffn {Scheme Variable} connman-service-type
10450 This is the service type to run @url{https://01.org/connman,Connman},
10451 a network connection manager.
10453 Its value must be an
10454 @code{connman-configuration} record as in this example:
10457 (service connman-service-type
10458 (connman-configuration
10459 (disable-vpn? #t)))
10462 See below for details about @code{connman-configuration}.
10465 @deftp {Data Type} connman-configuration
10466 Data Type representing the configuration of connman.
10469 @item @code{connman} (default: @var{connman})
10470 The connman package to use.
10472 @item @code{disable-vpn?} (default: @code{#f})
10473 When true, enable connman's vpn plugin.
10477 @cindex WPA Supplicant
10478 @defvr {Scheme Variable} wpa-supplicant-service-type
10479 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
10480 supplicant}, an authentication daemon required to authenticate against
10481 encrypted WiFi or ethernet networks. It is configured to listen for
10484 The value of this service is the @code{wpa-supplicant} package to use.
10485 Thus, it can be instantiated like this:
10488 (use-modules (gnu services networking))
10490 (service wpa-supplicant-service-type)
10495 @cindex real time clock
10496 @deffn {Scheme Procedure} ntp-service [#:ntp @var{ntp}] @
10497 [#:servers @var{%ntp-servers}] @
10498 [#:allow-large-adjustment? #f]
10499 Return a service that runs the daemon from @var{ntp}, the
10500 @uref{http://www.ntp.org, Network Time Protocol package}. The daemon will
10501 keep the system clock synchronized with that of @var{servers}.
10502 @var{allow-large-adjustment?} determines whether @command{ntpd} is allowed to
10503 make an initial adjustment of more than 1,000 seconds.
10506 @defvr {Scheme Variable} %ntp-servers
10507 List of host names used as the default NTP servers.
10511 @deffn {Scheme variable} inetd-service-type
10512 This service runs the @command{inetd} (@pxref{inetd invocation,,,
10513 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
10514 connections on internet sockets, and lazily starts the specified server
10515 program when a connection is made on one of these sockets.
10517 The value of this service is an @code{inetd-configuration} object. The
10518 following example configures the @command{inetd} daemon to provide the
10519 built-in @command{echo} service, as well as an smtp service which
10520 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
10521 gateway @code{hostname}:
10526 (inetd-configuration
10530 (socket-type 'stream)
10537 (socket-type 'stream)
10541 (program (file-append openssh "/bin/ssh"))
10543 '("ssh" "-qT" "-i" "/path/to/ssh_key"
10544 "-W" "smtp-server:25" "user@@hostname")))))
10547 See below for more details about @code{inetd-configuration}.
10550 @deftp {Data Type} inetd-configuration
10551 Data type representing the configuration of @command{inetd}.
10554 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
10555 The @command{inetd} executable to use.
10557 @item @code{entries} (default: @code{'()})
10558 A list of @command{inetd} service entries. Each entry should be created
10559 by the @code{inetd-entry} constructor.
10563 @deftp {Data Type} inetd-entry
10564 Data type representing an entry in the @command{inetd} configuration.
10565 Each entry corresponds to a socket where @command{inetd} will listen for
10569 @item @code{node} (default: @code{#f})
10570 Optional string, a comma-separated list of local addresses
10571 @command{inetd} should use when listening for this service.
10572 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
10573 description of all options.
10575 A string, the name must correspond to an entry in @code{/etc/services}.
10576 @item @code{socket-type}
10577 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
10579 @item @code{protocol}
10580 A string, must correspond to an entry in @code{/etc/protocols}.
10581 @item @code{wait?} (default: @code{#t})
10582 Whether @command{inetd} should wait for the server to exit before
10583 listening to new service requests.
10585 A string containing the user (and, optionally, group) name of the user
10586 as whom the server should run. The group name can be specified in a
10587 suffix, separated by a colon or period, i.e. @code{"user"},
10588 @code{"user:group"} or @code{"user.group"}.
10589 @item @code{program} (default: @code{"internal"})
10590 The server program which will serve the requests, or @code{"internal"}
10591 if @command{inetd} should use a built-in service.
10592 @item @code{arguments} (default: @code{'()})
10593 A list strings or file-like objects, which are the server program's
10594 arguments, starting with the zeroth argument, i.e. the name of the
10595 program itself. For @command{inetd}'s internal services, this entry
10596 must be @code{'()} or @code{'("internal")}.
10599 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
10600 detailed discussion of each configuration field.
10604 @deffn {Scheme Procedure} tor-service [@var{config-file}] [#:tor @var{tor}]
10605 Return a service to run the @uref{https://torproject.org, Tor} anonymous
10608 The daemon runs as the @code{tor} unprivileged user. It is passed
10609 @var{config-file}, a file-like object, with an additional @code{User tor} line
10610 and lines for hidden services added via @code{tor-hidden-service}. Run
10611 @command{man tor} for information about the configuration file.
10614 @cindex hidden service
10615 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
10616 Define a new Tor @dfn{hidden service} called @var{name} and implementing
10617 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
10620 '((22 "127.0.0.1:22")
10621 (80 "127.0.0.1:8080"))
10624 In this example, port 22 of the hidden service is mapped to local port 22, and
10625 port 80 is mapped to local port 8080.
10627 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
10628 the @file{hostname} file contains the @code{.onion} host name for the hidden
10631 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
10632 project's documentation} for more information.
10635 @deffn {Scheme Procedure} bitlbee-service [#:bitlbee bitlbee] @
10636 [#:interface "127.0.0.1"] [#:port 6667] @
10637 [#:extra-settings ""]
10638 Return a service that runs @url{http://bitlbee.org,BitlBee}, a daemon that
10639 acts as a gateway between IRC and chat networks.
10641 The daemon will listen to the interface corresponding to the IP address
10642 specified in @var{interface}, on @var{port}. @code{127.0.0.1} means that only
10643 local clients can connect, whereas @code{0.0.0.0} means that connections can
10644 come from any networking interface.
10646 In addition, @var{extra-settings} specifies a string to append to the
10647 configuration file.
10650 The @code{(gnu services rsync)} module provides the following services:
10652 You might want an rsync daemon if you have files that you want available
10653 so anyone (or just yourself) can download existing files or upload new
10656 @deffn {Scheme Variable} rsync-service-type
10657 This is the type for the @uref{https://rsync.samba.org, rsync} rsync daemon,
10658 @command{rsync-configuration} record as in this example:
10661 (service rsync-service-type)
10664 See below for details about @code{rsync-configuration}.
10667 @deftp {Data Type} rsync-configuration
10668 Data type representing the configuration for @code{rsync-service}.
10671 @item @code{package} (default: @var{rsync})
10672 @code{rsync} package to use.
10674 @item @code{port-number} (default: @code{873})
10675 TCP port on which @command{rsync} listens for incoming connections. If port
10676 is less than @code{1024} @command{rsync} needs to be started as the
10677 @code{root} user and group.
10679 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
10680 Name of the file where @command{rsync} writes its PID.
10682 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
10683 Name of the file where @command{rsync} writes its lock file.
10685 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
10686 Name of the file where @command{rsync} writes its log file.
10688 @item @code{use-chroot?} (default: @var{#t})
10689 Whether to use chroot for @command{rsync} shared directory.
10691 @item @code{share-path} (default: @file{/srv/rsync})
10692 Location of the @command{rsync} shared directory.
10694 @item @code{share-comment} (default: @code{"Rsync share"})
10695 Comment of the @command{rsync} shared directory.
10697 @item @code{read-only?} (default: @var{#f})
10698 Read-write permissions to shared directory.
10700 @item @code{timeout} (default: @code{300})
10701 I/O timeout in seconds.
10703 @item @code{user} (default: @var{"root"})
10704 Owner of the @code{rsync} process.
10706 @item @code{group} (default: @var{"root"})
10707 Group of the @code{rsync} process.
10709 @item @code{uid} (default: @var{"rsyncd"})
10710 User name or user ID that file transfers to and from that module should take
10711 place as when the daemon was run as @code{root}.
10713 @item @code{gid} (default: @var{"rsyncd"})
10714 Group name or group ID that will be used when accessing the module.
10719 Furthermore, @code{(gnu services ssh)} provides the following services.
10723 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
10724 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
10725 [#:allow-empty-passwords? #f] [#:root-login? #f] @
10726 [#:syslog-output? #t] [#:x11-forwarding? #t] @
10727 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
10728 [#:public-key-authentication? #t] [#:initialize? #t]
10729 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
10730 @var{host-key} must designate a file containing the host key, and readable
10733 When @var{daemonic?} is true, @command{lshd} will detach from the
10734 controlling terminal and log its output to syslogd, unless one sets
10735 @var{syslog-output?} to false. Obviously, it also makes lsh-service
10736 depend on existence of syslogd service. When @var{pid-file?} is true,
10737 @command{lshd} writes its PID to the file called @var{pid-file}.
10739 When @var{initialize?} is true, automatically create the seed and host key
10740 upon service activation if they do not exist yet. This may take long and
10741 require interaction.
10743 When @var{initialize?} is false, it is up to the user to initialize the
10744 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
10745 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
10746 basics,,, lsh, LSH Manual}).
10748 When @var{interfaces} is empty, lshd listens for connections on all the
10749 network interfaces; otherwise, @var{interfaces} must be a list of host names
10752 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
10753 passwords, and @var{root-login?} specifies whether to accept log-ins as
10756 The other options should be self-descriptive.
10761 @deffn {Scheme Variable} openssh-service-type
10762 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
10763 shell daemon, @command{sshd}. Its value must be an
10764 @code{openssh-configuration} record as in this example:
10767 (service openssh-service-type
10768 (openssh-configuration
10769 (x11-forwarding? #t)
10770 (permit-root-login 'without-password)
10772 `(("alice" ,(local-file "alice.pub"))
10773 ("bob" ,(local-file "bob.pub"))))))
10776 See below for details about @code{openssh-configuration}.
10778 This service can be extended with extra authorized keys, as in this
10782 (service-extension openssh-service-type
10783 (const `(("charlie"
10784 ,(local-file "charlie.pub")))))
10788 @deftp {Data Type} openssh-configuration
10789 This is the configuration record for OpenSSH's @command{sshd}.
10792 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
10793 Name of the file where @command{sshd} writes its PID.
10795 @item @code{port-number} (default: @code{22})
10796 TCP port on which @command{sshd} listens for incoming connections.
10798 @item @code{permit-root-login} (default: @code{#f})
10799 This field determines whether and when to allow logins as root. If
10800 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
10801 If it's the symbol @code{'without-password}, then root logins are
10802 permitted but not with password-based authentication.
10804 @item @code{allow-empty-passwords?} (default: @code{#f})
10805 When true, users with empty passwords may log in. When false, they may
10808 @item @code{password-authentication?} (default: @code{#t})
10809 When true, users may log in with their password. When false, they have
10810 other authentication methods.
10812 @item @code{public-key-authentication?} (default: @code{#t})
10813 When true, users may log in using public key authentication. When
10814 false, users have to use other authentication method.
10816 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
10817 This is used only by protocol version 2.
10819 @item @code{x11-forwarding?} (default: @code{#f})
10820 When true, forwarding of X11 graphical client connections is
10821 enabled---in other words, @command{ssh} options @option{-X} and
10822 @option{-Y} will work.
10824 @item @code{challenge-response-authentication?} (default: @code{#f})
10825 Specifies whether challenge response authentication is allowed (e.g. via
10828 @item @code{use-pam?} (default: @code{#t})
10829 Enables the Pluggable Authentication Module interface. If set to
10830 @code{#t}, this will enable PAM authentication using
10831 @code{challenge-response-authentication?} and
10832 @code{password-authentication?}, in addition to PAM account and session
10833 module processing for all authentication types.
10835 Because PAM challenge response authentication usually serves an
10836 equivalent role to password authentication, you should disable either
10837 @code{challenge-response-authentication?} or
10838 @code{password-authentication?}.
10840 @item @code{print-last-log?} (default: @code{#t})
10841 Specifies whether @command{sshd} should print the date and time of the
10842 last user login when a user logs in interactively.
10844 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
10845 Configures external subsystems (e.g. file transfer daemon).
10847 This is a list of two-element lists, each of which containing the
10848 subsystem name and a command (with optional arguments) to execute upon
10851 The command @command{internal-sftp} implements an in-process SFTP
10852 server. Alternately, one can specify the @command{sftp-server} command:
10854 (service openssh-service-type
10855 (openssh-configuration
10857 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
10860 @item @code{authorized-keys} (default: @code{'()})
10861 @cindex authorized keys, SSH
10862 @cindex SSH authorized keys
10863 This is the list of authorized keys. Each element of the list is a user
10864 name followed by one or more file-like objects that represent SSH public
10868 (openssh-configuration
10870 `(("rekado" ,(local-file "rekado.pub"))
10871 ("chris" ,(local-file "chris.pub"))
10872 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
10876 registers the specified public keys for user accounts @code{rekado},
10877 @code{chris}, and @code{root}.
10879 Additional authorized keys can be specified @i{via}
10880 @code{service-extension}.
10882 Note that this does @emph{not} interfere with the use of
10883 @file{~/.ssh/authorized_keys}.
10887 @deffn {Scheme Procedure} dropbear-service [@var{config}]
10888 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
10889 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
10892 For example, to specify a Dropbear service listening on port 1234, add
10893 this call to the operating system's @code{services} field:
10896 (dropbear-service (dropbear-configuration
10897 (port-number 1234)))
10901 @deftp {Data Type} dropbear-configuration
10902 This data type represents the configuration of a Dropbear SSH daemon.
10905 @item @code{dropbear} (default: @var{dropbear})
10906 The Dropbear package to use.
10908 @item @code{port-number} (default: 22)
10909 The TCP port where the daemon waits for incoming connections.
10911 @item @code{syslog-output?} (default: @code{#t})
10912 Whether to enable syslog output.
10914 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
10915 File name of the daemon's PID file.
10917 @item @code{root-login?} (default: @code{#f})
10918 Whether to allow @code{root} logins.
10920 @item @code{allow-empty-passwords?} (default: @code{#f})
10921 Whether to allow empty passwords.
10923 @item @code{password-authentication?} (default: @code{#t})
10924 Whether to enable password-based authentication.
10928 @defvr {Scheme Variable} %facebook-host-aliases
10929 This variable contains a string for use in @file{/etc/hosts}
10930 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
10931 line contains a entry that maps a known server name of the Facebook
10932 on-line service---e.g., @code{www.facebook.com}---to the local
10933 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
10935 This variable is typically used in the @code{hosts-file} field of an
10936 @code{operating-system} declaration (@pxref{operating-system Reference,
10937 @file{/etc/hosts}}):
10940 (use-modules (gnu) (guix))
10943 (host-name "mymachine")
10946 ;; Create a /etc/hosts file with aliases for "localhost"
10947 ;; and "mymachine", as well as for Facebook servers.
10948 (plain-file "hosts"
10949 (string-append (local-host-aliases host-name)
10950 %facebook-host-aliases))))
10953 This mechanism can prevent programs running locally, such as Web
10954 browsers, from accessing Facebook.
10957 The @code{(gnu services avahi)} provides the following definition.
10959 @deffn {Scheme Procedure} avahi-service [#:avahi @var{avahi}] @
10960 [#:host-name #f] [#:publish? #t] [#:ipv4? #t] @
10961 [#:ipv6? #t] [#:wide-area? #f] @
10962 [#:domains-to-browse '()] [#:debug? #f]
10963 Return a service that runs @command{avahi-daemon}, a system-wide
10964 mDNS/DNS-SD responder that allows for service discovery and
10965 "zero-configuration" host name lookups (see @uref{http://avahi.org/}), and
10966 extends the name service cache daemon (nscd) so that it can resolve
10967 @code{.local} host names using
10968 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. Additionally,
10969 add the @var{avahi} package to the system profile so that commands such as
10970 @command{avahi-browse} are directly usable.
10972 If @var{host-name} is different from @code{#f}, use that as the host name to
10973 publish for this machine; otherwise, use the machine's actual host name.
10975 When @var{publish?} is true, publishing of host names and services is allowed;
10976 in particular, avahi-daemon will publish the machine's host name and IP
10977 address via mDNS on the local network.
10979 When @var{wide-area?} is true, DNS-SD over unicast DNS is enabled.
10981 Boolean values @var{ipv4?} and @var{ipv6?} determine whether to use IPv4/IPv6
10985 @deffn {Scheme Variable} openvswitch-service-type
10986 This is the type of the @uref{http://www.openvswitch.org, Open vSwitch}
10987 service, whose value should be an @code{openvswitch-configuration}
10991 @deftp {Data Type} openvswitch-configuration
10992 Data type representing the configuration of Open vSwitch, a multilayer
10993 virtual switch which is designed to enable massive network automation
10994 through programmatic extension.
10997 @item @code{package} (default: @var{openvswitch})
10998 Package object of the Open vSwitch.
11004 @subsubsection X Window
11007 @cindex X Window System
11008 @cindex login manager
11009 Support for the X Window graphical display system---specifically
11010 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
11011 there is no @code{xorg-service} procedure. Instead, the X server is
11012 started by the @dfn{login manager}, by default SLiM.
11014 @cindex window manager
11015 To use X11, you must install at least one @dfn{window manager}---for
11016 example the @code{windowmaker} or @code{openbox} packages---preferably
11017 by adding it to the @code{packages} field of your operating system
11018 definition (@pxref{operating-system Reference, system-wide packages}).
11020 @defvr {Scheme Variable} slim-service-type
11021 This is the type for the SLiM graphical login manager for X11.
11023 @cindex session types (X11)
11024 @cindex X11 session types
11025 SLiM looks for @dfn{session types} described by the @file{.desktop} files in
11026 @file{/run/current-system/profile/share/xsessions} and allows users to
11027 choose a session from the log-in screen using @kbd{F1}. Packages such
11028 as @code{xfce}, @code{sawfish}, and @code{ratpoison} provide
11029 @file{.desktop} files; adding them to the system-wide set of packages
11030 automatically makes them available at the log-in screen.
11032 In addition, @file{~/.xsession} files are honored. When available,
11033 @file{~/.xsession} must be an executable that starts a window manager
11034 and/or other X clients.
11037 @deftp {Data Type} slim-configuration
11038 Data type representing the configuration of @code{slim-service-type}.
11041 @item @code{allow-empty-passwords?} (default: @code{#t})
11042 Whether to allow logins with empty passwords.
11044 @item @code{auto-login?} (default: @code{#f})
11045 @itemx @code{default-user} (default: @code{""})
11046 When @code{auto-login?} is false, SLiM presents a log-in screen.
11048 When @code{auto-login?} is true, SLiM logs in directly as
11049 @code{default-user}.
11051 @item @code{theme} (default: @code{%default-slim-theme})
11052 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
11053 The graphical theme to use and its name.
11055 @item @code{auto-login-session} (default: @code{#f})
11056 If true, this must be the name of the executable to start as the default
11057 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
11059 If false, a session described by one of the available @file{.desktop}
11060 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
11064 You must install at least one window manager in the system profile or in
11065 your user profile. Failing to do that, if @code{auto-login-session} is
11066 false, you will be unable to log in.
11069 @item @code{startx} (default: @code{(xorg-start-command)})
11070 The command used to start the X11 graphical server.
11072 @item @code{xauth} (default: @code{xauth})
11073 The XAuth package to use.
11075 @item @code{shepherd} (default: @code{shepherd})
11076 The Shepherd package used when invoking @command{halt} and
11079 @item @code{slim} (default: @code{slim})
11080 The SLiM package to use.
11084 @defvr {Scheme Variable} %default-theme
11085 @defvrx {Scheme Variable} %default-theme-name
11086 The default SLiM theme and its name.
11090 @deftp {Data Type} sddm-configuration
11091 This is the data type representing the sddm service configuration.
11094 @item @code{display-server} (default: "x11")
11095 Select display server to use for the greeter. Valid values are "x11"
11098 @item @code{numlock} (default: "on")
11099 Valid values are "on", "off" or "none".
11101 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
11102 Command to run when halting.
11104 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
11105 Command to run when rebooting.
11107 @item @code{theme} (default "maldives")
11108 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
11110 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
11111 Directory to look for themes.
11113 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
11114 Directory to look for faces.
11116 @item @code{default-path} (default "/run/current-system/profile/bin")
11117 Default PATH to use.
11119 @item @code{minimum-uid} (default 1000)
11120 Minimum UID to display in SDDM.
11122 @item @code{maximum-uid} (default 2000)
11123 Maximum UID to display in SDDM
11125 @item @code{remember-last-user?} (default #t)
11126 Remember last user.
11128 @item @code{remember-last-session?} (default #t)
11129 Remember last session.
11131 @item @code{hide-users} (default "")
11132 Usernames to hide from SDDM greeter.
11134 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
11135 Users with shells listed will be hidden from the SDDM greeter.
11137 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
11138 Script to run before starting a wayland session.
11140 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
11141 Directory to look for desktop files starting wayland sessions.
11143 @item @code{xorg-server-path} (default @code{xorg-start-command})
11144 Path to xorg-server.
11146 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
11149 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
11152 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
11153 Script to run after starting xorg-server.
11155 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
11156 Script to run before stopping xorg-server.
11158 @item @code{xsession-command} (default: @code{xinitr })
11159 Script to run before starting a X session.
11161 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
11162 Directory to look for desktop files starting X sessions.
11164 @item @code{minimum-vt} (default: 7)
11167 @item @code{xserver-arguments} (default "-nolisten tcp")
11168 Arguments to pass to xorg-server.
11170 @item @code{auto-login-user} (default "")
11171 User to use for auto-login.
11173 @item @code{auto-login-session} (default "")
11174 Desktop file to use for auto-login.
11176 @item @code{relogin?} (default #f)
11177 Relogin after logout.
11182 @cindex login manager
11184 @deffn {Scheme Procedure} sddm-service config
11185 Return a service that spawns the SDDM graphical login manager for config of
11186 type @code{<sddm-configuration>}.
11189 (sddm-service (sddm-configuration
11190 (auto-login-user "Alice")
11191 (auto-login-session "xfce.desktop")))
11195 @deffn {Scheme Procedure} xorg-start-command [#:guile] @
11196 [#:modules %default-xorg-modules] @
11197 [#:fonts %default-xorg-fonts] @
11198 [#:configuration-file (xorg-configuration-file @dots{})] @
11199 [#:xorg-server @var{xorg-server}]
11200 Return a @code{startx} script in which @var{modules}, a list of X module
11201 packages, and @var{fonts}, a list of X font directories, are available. See
11202 @code{xorg-wrapper} for more details on the arguments. The result should be
11203 used in place of @code{startx}.
11205 Usually the X server is started by a login manager.
11208 @deffn {Scheme Procedure} xorg-configuration-file @
11209 [#:modules %default-xorg-modules] @
11210 [#:fonts %default-xorg-fonts] @
11211 [#:drivers '()] [#:resolutions '()] [#:extra-config '()]
11212 Return a configuration file for the Xorg server containing search paths for
11213 all the common drivers.
11215 @var{modules} must be a list of @dfn{module packages} loaded by the Xorg
11216 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
11217 @var{fonts} must be a list of font directories to add to the server's
11220 @var{drivers} must be either the empty list, in which case Xorg chooses a
11221 graphics driver automatically, or a list of driver names that will be tried in
11222 this order---e.g., @code{("modesetting" "vesa")}.
11224 Likewise, when @var{resolutions} is the empty list, Xorg chooses an
11225 appropriate screen resolution; otherwise, it must be a list of
11226 resolutions---e.g., @code{((1024 768) (640 480))}.
11228 Last, @var{extra-config} is a list of strings or objects appended to the
11229 configuration file. It is used to pass extra text to be
11230 added verbatim to the configuration file.
11233 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{name}]
11234 Add @var{package}, a package for a screen-locker or screen-saver whose
11235 command is @var{program}, to the set of setuid programs and add a PAM entry
11236 for it. For example:
11239 (screen-locker-service xlockmore "xlock")
11242 makes the good ol' XlockMore usable.
11246 @node Printing Services
11247 @subsubsection Printing Services
11249 @cindex printer support with CUPS
11250 The @code{(gnu services cups)} module provides a Guix service definition
11251 for the CUPS printing service. To add printer support to a GuixSD
11252 system, add a @code{cups-service} to the operating system definition:
11254 @deffn {Scheme Variable} cups-service-type
11255 The service type for the CUPS print server. Its value should be a valid
11256 CUPS configuration (see below). To use the default settings, simply
11259 (service cups-service-type)
11263 The CUPS configuration controls the basic things about your CUPS
11264 installation: what interfaces it listens on, what to do if a print job
11265 fails, how much logging to do, and so on. To actually add a printer,
11266 you have to visit the @url{http://localhost:631} URL, or use a tool such
11267 as GNOME's printer configuration services. By default, configuring a
11268 CUPS service will generate a self-signed certificate if needed, for
11269 secure connections to the print server.
11271 Suppose you want to enable the Web interface of CUPS and also add
11272 support for HP printers @i{via} the @code{hplip} package. You can do
11273 that directly, like this (you need to use the @code{(gnu packages cups)}
11277 (service cups-service-type
11278 (cups-configuration
11279 (web-interface? #t)
11281 (list cups-filters hplip))))
11284 The available configuration parameters follow. Each parameter
11285 definition is preceded by its type; for example, @samp{string-list foo}
11286 indicates that the @code{foo} parameter should be specified as a list of
11287 strings. There is also a way to specify the configuration as a string,
11288 if you have an old @code{cupsd.conf} file that you want to port over
11289 from some other system; see the end for more details.
11291 @c The following documentation was initially generated by
11292 @c (generate-documentation) in (gnu services cups). Manually maintained
11293 @c documentation is better, so we shouldn't hesitate to edit below as
11294 @c needed. However if the change you want to make to this documentation
11295 @c can be done in an automated way, it's probably easier to change
11296 @c (generate-documentation) than to make it below and have to deal with
11297 @c the churn as CUPS updates.
11300 Available @code{cups-configuration} fields are:
11302 @deftypevr {@code{cups-configuration} parameter} package cups
11306 @deftypevr {@code{cups-configuration} parameter} package-list extensions
11307 Drivers and other extensions to the CUPS package.
11310 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
11311 Configuration of where to write logs, what directories to use for print
11312 spools, and related privileged configuration parameters.
11314 Available @code{files-configuration} fields are:
11316 @deftypevr {@code{files-configuration} parameter} log-location access-log
11317 Defines the access log filename. Specifying a blank filename disables
11318 access log generation. The value @code{stderr} causes log entries to be
11319 sent to the standard error file when the scheduler is running in the
11320 foreground, or to the system log daemon when run in the background. The
11321 value @code{syslog} causes log entries to be sent to the system log
11322 daemon. The server name may be included in filenames using the string
11323 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
11325 Defaults to @samp{"/var/log/cups/access_log"}.
11328 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
11329 Where CUPS should cache data.
11331 Defaults to @samp{"/var/cache/cups"}.
11334 @deftypevr {@code{files-configuration} parameter} string config-file-perm
11335 Specifies the permissions for all configuration files that the scheduler
11338 Note that the permissions for the printers.conf file are currently
11339 masked to only allow access from the scheduler user (typically root).
11340 This is done because printer device URIs sometimes contain sensitive
11341 authentication information that should not be generally known on the
11342 system. There is no way to disable this security feature.
11344 Defaults to @samp{"0640"}.
11347 @deftypevr {@code{files-configuration} parameter} log-location error-log
11348 Defines the error log filename. Specifying a blank filename disables
11349 access log generation. The value @code{stderr} causes log entries to be
11350 sent to the standard error file when the scheduler is running in the
11351 foreground, or to the system log daemon when run in the background. The
11352 value @code{syslog} causes log entries to be sent to the system log
11353 daemon. The server name may be included in filenames using the string
11354 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
11356 Defaults to @samp{"/var/log/cups/error_log"}.
11359 @deftypevr {@code{files-configuration} parameter} string fatal-errors
11360 Specifies which errors are fatal, causing the scheduler to exit. The
11365 No errors are fatal.
11368 All of the errors below are fatal.
11371 Browsing initialization errors are fatal, for example failed connections
11372 to the DNS-SD daemon.
11375 Configuration file syntax errors are fatal.
11378 Listen or Port errors are fatal, except for IPv6 failures on the
11379 loopback or @code{any} addresses.
11382 Log file creation or write errors are fatal.
11385 Bad startup file permissions are fatal, for example shared TLS
11386 certificate and key files with world-read permissions.
11389 Defaults to @samp{"all -browse"}.
11392 @deftypevr {@code{files-configuration} parameter} boolean file-device?
11393 Specifies whether the file pseudo-device can be used for new printer
11394 queues. The URI @uref{file:///dev/null} is always allowed.
11396 Defaults to @samp{#f}.
11399 @deftypevr {@code{files-configuration} parameter} string group
11400 Specifies the group name or ID that will be used when executing external
11403 Defaults to @samp{"lp"}.
11406 @deftypevr {@code{files-configuration} parameter} string log-file-perm
11407 Specifies the permissions for all log files that the scheduler writes.
11409 Defaults to @samp{"0644"}.
11412 @deftypevr {@code{files-configuration} parameter} log-location page-log
11413 Defines the page log filename. Specifying a blank filename disables
11414 access log generation. The value @code{stderr} causes log entries to be
11415 sent to the standard error file when the scheduler is running in the
11416 foreground, or to the system log daemon when run in the background. The
11417 value @code{syslog} causes log entries to be sent to the system log
11418 daemon. The server name may be included in filenames using the string
11419 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
11421 Defaults to @samp{"/var/log/cups/page_log"}.
11424 @deftypevr {@code{files-configuration} parameter} string remote-root
11425 Specifies the username that is associated with unauthenticated accesses
11426 by clients claiming to be the root user. The default is @code{remroot}.
11428 Defaults to @samp{"remroot"}.
11431 @deftypevr {@code{files-configuration} parameter} file-name request-root
11432 Specifies the directory that contains print jobs and other HTTP request
11435 Defaults to @samp{"/var/spool/cups"}.
11438 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
11439 Specifies the level of security sandboxing that is applied to print
11440 filters, backends, and other child processes of the scheduler; either
11441 @code{relaxed} or @code{strict}. This directive is currently only
11442 used/supported on macOS.
11444 Defaults to @samp{strict}.
11447 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
11448 Specifies the location of TLS certificates and private keys. CUPS will
11449 look for public and private keys in this directory: a @code{.crt} files
11450 for PEM-encoded certificates and corresponding @code{.key} files for
11451 PEM-encoded private keys.
11453 Defaults to @samp{"/etc/cups/ssl"}.
11456 @deftypevr {@code{files-configuration} parameter} file-name server-root
11457 Specifies the directory containing the server configuration files.
11459 Defaults to @samp{"/etc/cups"}.
11462 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
11463 Specifies whether the scheduler calls fsync(2) after writing
11464 configuration or state files.
11466 Defaults to @samp{#f}.
11469 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
11470 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
11473 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
11474 Specifies the directory where temporary files are stored.
11476 Defaults to @samp{"/var/spool/cups/tmp"}.
11479 @deftypevr {@code{files-configuration} parameter} string user
11480 Specifies the user name or ID that is used when running external
11483 Defaults to @samp{"lp"}.
11487 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
11488 Specifies the logging level for the AccessLog file. The @code{config}
11489 level logs when printers and classes are added, deleted, or modified and
11490 when configuration files are accessed or updated. The @code{actions}
11491 level logs when print jobs are submitted, held, released, modified, or
11492 canceled, and any of the conditions for @code{config}. The @code{all}
11493 level logs all requests.
11495 Defaults to @samp{actions}.
11498 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
11499 Specifies whether to purge job history data automatically when it is no
11500 longer required for quotas.
11502 Defaults to @samp{#f}.
11505 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
11506 Specifies which protocols to use for local printer sharing.
11508 Defaults to @samp{dnssd}.
11511 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
11512 Specifies whether the CUPS web interface is advertised.
11514 Defaults to @samp{#f}.
11517 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
11518 Specifies whether shared printers are advertised.
11520 Defaults to @samp{#f}.
11523 @deftypevr {@code{cups-configuration} parameter} string classification
11524 Specifies the security classification of the server. Any valid banner
11525 name can be used, including "classified", "confidential", "secret",
11526 "topsecret", and "unclassified", or the banner can be omitted to disable
11527 secure printing functions.
11529 Defaults to @samp{""}.
11532 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
11533 Specifies whether users may override the classification (cover page) of
11534 individual print jobs using the @code{job-sheets} option.
11536 Defaults to @samp{#f}.
11539 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
11540 Specifies the default type of authentication to use.
11542 Defaults to @samp{Basic}.
11545 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
11546 Specifies whether encryption will be used for authenticated requests.
11548 Defaults to @samp{Required}.
11551 @deftypevr {@code{cups-configuration} parameter} string default-language
11552 Specifies the default language to use for text and web content.
11554 Defaults to @samp{"en"}.
11557 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
11558 Specifies the default paper size for new print queues. @samp{"Auto"}
11559 uses a locale-specific default, while @samp{"None"} specifies there is
11560 no default paper size. Specific size names are typically
11561 @samp{"Letter"} or @samp{"A4"}.
11563 Defaults to @samp{"Auto"}.
11566 @deftypevr {@code{cups-configuration} parameter} string default-policy
11567 Specifies the default access policy to use.
11569 Defaults to @samp{"default"}.
11572 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
11573 Specifies whether local printers are shared by default.
11575 Defaults to @samp{#t}.
11578 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
11579 Specifies the delay for updating of configuration and state files, in
11580 seconds. A value of 0 causes the update to happen as soon as possible,
11581 typically within a few milliseconds.
11583 Defaults to @samp{30}.
11586 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
11587 Specifies what to do when an error occurs. Possible values are
11588 @code{abort-job}, which will discard the failed print job;
11589 @code{retry-job}, which will retry the job at a later time;
11590 @code{retry-this-job}, which retries the failed job immediately; and
11591 @code{stop-printer}, which stops the printer.
11593 Defaults to @samp{stop-printer}.
11596 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
11597 Specifies the maximum cost of filters that are run concurrently, which
11598 can be used to minimize disk, memory, and CPU resource problems. A
11599 limit of 0 disables filter limiting. An average print to a
11600 non-PostScript printer needs a filter limit of about 200. A PostScript
11601 printer needs about half that (100). Setting the limit below these
11602 thresholds will effectively limit the scheduler to printing a single job
11605 Defaults to @samp{0}.
11608 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
11609 Specifies the scheduling priority of filters that are run to print a
11610 job. The nice value ranges from 0, the highest priority, to 19, the
11613 Defaults to @samp{0}.
11616 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
11617 Specifies whether to do reverse lookups on connecting clients. The
11618 @code{double} setting causes @code{cupsd} to verify that the hostname
11619 resolved from the address matches one of the addresses returned for that
11620 hostname. Double lookups also prevent clients with unregistered
11621 addresses from connecting to your server. Only set this option to
11622 @code{#t} or @code{double} if absolutely required.
11624 Defaults to @samp{#f}.
11627 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
11628 Specifies the number of seconds to wait before killing the filters and
11629 backend associated with a canceled or held job.
11631 Defaults to @samp{30}.
11634 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
11635 Specifies the interval between retries of jobs in seconds. This is
11636 typically used for fax queues but can also be used with normal print
11637 queues whose error policy is @code{retry-job} or
11638 @code{retry-current-job}.
11640 Defaults to @samp{30}.
11643 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
11644 Specifies the number of retries that are done for jobs. This is
11645 typically used for fax queues but can also be used with normal print
11646 queues whose error policy is @code{retry-job} or
11647 @code{retry-current-job}.
11649 Defaults to @samp{5}.
11652 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
11653 Specifies whether to support HTTP keep-alive connections.
11655 Defaults to @samp{#t}.
11658 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
11659 Specifies how long an idle client connection remains open, in seconds.
11661 Defaults to @samp{30}.
11664 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
11665 Specifies the maximum size of print files, IPP requests, and HTML form
11666 data. A limit of 0 disables the limit check.
11668 Defaults to @samp{0}.
11671 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
11672 Listens on the specified interfaces for connections. Valid values are
11673 of the form @var{address}:@var{port}, where @var{address} is either an
11674 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
11675 indicate all addresses. Values can also be file names of local UNIX
11676 domain sockets. The Listen directive is similar to the Port directive
11677 but allows you to restrict access to specific interfaces or networks.
11680 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
11681 Specifies the number of pending connections that will be allowed. This
11682 normally only affects very busy servers that have reached the MaxClients
11683 limit, but can also be triggered by large numbers of simultaneous
11684 connections. When the limit is reached, the operating system will
11685 refuse additional connections until the scheduler can accept the pending
11688 Defaults to @samp{128}.
11691 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
11692 Specifies a set of additional access controls.
11694 Available @code{location-access-controls} fields are:
11696 @deftypevr {@code{location-access-controls} parameter} file-name path
11697 Specifies the URI path to which the access control applies.
11700 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
11701 Access controls for all access to this path, in the same format as the
11702 @code{access-controls} of @code{operation-access-control}.
11704 Defaults to @samp{()}.
11707 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
11708 Access controls for method-specific access to this path.
11710 Defaults to @samp{()}.
11712 Available @code{method-access-controls} fields are:
11714 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
11715 If @code{#t}, apply access controls to all methods except the listed
11716 methods. Otherwise apply to only the listed methods.
11718 Defaults to @samp{#f}.
11721 @deftypevr {@code{method-access-controls} parameter} method-list methods
11722 Methods to which this access control applies.
11724 Defaults to @samp{()}.
11727 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
11728 Access control directives, as a list of strings. Each string should be
11729 one directive, such as "Order allow,deny".
11731 Defaults to @samp{()}.
11736 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
11737 Specifies the number of debugging messages that are retained for logging
11738 if an error occurs in a print job. Debug messages are logged regardless
11739 of the LogLevel setting.
11741 Defaults to @samp{100}.
11744 @deftypevr {@code{cups-configuration} parameter} log-level log-level
11745 Specifies the level of logging for the ErrorLog file. The value
11746 @code{none} stops all logging while @code{debug2} logs everything.
11748 Defaults to @samp{info}.
11751 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
11752 Specifies the format of the date and time in the log files. The value
11753 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
11755 Defaults to @samp{standard}.
11758 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
11759 Specifies the maximum number of simultaneous clients that are allowed by
11762 Defaults to @samp{100}.
11765 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
11766 Specifies the maximum number of simultaneous clients that are allowed
11767 from a single address.
11769 Defaults to @samp{100}.
11772 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
11773 Specifies the maximum number of copies that a user can print of each
11776 Defaults to @samp{9999}.
11779 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
11780 Specifies the maximum time a job may remain in the @code{indefinite}
11781 hold state before it is canceled. A value of 0 disables cancellation of
11784 Defaults to @samp{0}.
11787 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
11788 Specifies the maximum number of simultaneous jobs that are allowed. Set
11789 to 0 to allow an unlimited number of jobs.
11791 Defaults to @samp{500}.
11794 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
11795 Specifies the maximum number of simultaneous jobs that are allowed per
11796 printer. A value of 0 allows up to MaxJobs jobs per printer.
11798 Defaults to @samp{0}.
11801 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
11802 Specifies the maximum number of simultaneous jobs that are allowed per
11803 user. A value of 0 allows up to MaxJobs jobs per user.
11805 Defaults to @samp{0}.
11808 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
11809 Specifies the maximum time a job may take to print before it is
11810 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
11812 Defaults to @samp{10800}.
11815 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
11816 Specifies the maximum size of the log files before they are rotated, in
11817 bytes. The value 0 disables log rotation.
11819 Defaults to @samp{1048576}.
11822 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
11823 Specifies the maximum amount of time to allow between files in a
11824 multiple file print job, in seconds.
11826 Defaults to @samp{300}.
11829 @deftypevr {@code{cups-configuration} parameter} string page-log-format
11830 Specifies the format of PageLog lines. Sequences beginning with percent
11831 (@samp{%}) characters are replaced with the corresponding information,
11832 while all other characters are copied literally. The following percent
11833 sequences are recognized:
11837 insert a single percent character
11840 insert the value of the specified IPP attribute
11843 insert the number of copies for the current page
11846 insert the current page number
11849 insert the current date and time in common log format
11855 insert the printer name
11858 insert the username
11861 A value of the empty string disables page logging. The string @code{%p
11862 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
11863 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
11866 Defaults to @samp{""}.
11869 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
11870 Passes the specified environment variable(s) to child processes; a list
11873 Defaults to @samp{()}.
11876 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
11877 Specifies named access control policies.
11879 Available @code{policy-configuration} fields are:
11881 @deftypevr {@code{policy-configuration} parameter} string name
11882 Name of the policy.
11885 @deftypevr {@code{policy-configuration} parameter} string job-private-access
11886 Specifies an access list for a job's private values. @code{@@ACL} maps
11887 to the printer's requesting-user-name-allowed or
11888 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
11889 owner. @code{@@SYSTEM} maps to the groups listed for the
11890 @code{system-group} field of the @code{files-config} configuration,
11891 which is reified into the @code{cups-files.conf(5)} file. Other
11892 possible elements of the access list include specific user names, and
11893 @code{@@@var{group}} to indicate members of a specific group. The
11894 access list may also be simply @code{all} or @code{default}.
11896 Defaults to @samp{"@@OWNER @@SYSTEM"}.
11899 @deftypevr {@code{policy-configuration} parameter} string job-private-values
11900 Specifies the list of job values to make private, or @code{all},
11901 @code{default}, or @code{none}.
11903 Defaults to @samp{"job-name job-originating-host-name
11904 job-originating-user-name phone"}.
11907 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
11908 Specifies an access list for a subscription's private values.
11909 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
11910 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
11911 owner. @code{@@SYSTEM} maps to the groups listed for the
11912 @code{system-group} field of the @code{files-config} configuration,
11913 which is reified into the @code{cups-files.conf(5)} file. Other
11914 possible elements of the access list include specific user names, and
11915 @code{@@@var{group}} to indicate members of a specific group. The
11916 access list may also be simply @code{all} or @code{default}.
11918 Defaults to @samp{"@@OWNER @@SYSTEM"}.
11921 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
11922 Specifies the list of job values to make private, or @code{all},
11923 @code{default}, or @code{none}.
11925 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
11926 notify-subscriber-user-name notify-user-data"}.
11929 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
11930 Access control by IPP operation.
11932 Defaults to @samp{()}.
11936 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
11937 Specifies whether job files (documents) are preserved after a job is
11938 printed. If a numeric value is specified, job files are preserved for
11939 the indicated number of seconds after printing. Otherwise a boolean
11940 value applies indefinitely.
11942 Defaults to @samp{86400}.
11945 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
11946 Specifies whether the job history is preserved after a job is printed.
11947 If a numeric value is specified, the job history is preserved for the
11948 indicated number of seconds after printing. If @code{#t}, the job
11949 history is preserved until the MaxJobs limit is reached.
11951 Defaults to @samp{#t}.
11954 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
11955 Specifies the amount of time to wait for job completion before
11956 restarting the scheduler.
11958 Defaults to @samp{30}.
11961 @deftypevr {@code{cups-configuration} parameter} string rip-cache
11962 Specifies the maximum amount of memory to use when converting documents
11963 into bitmaps for a printer.
11965 Defaults to @samp{"128m"}.
11968 @deftypevr {@code{cups-configuration} parameter} string server-admin
11969 Specifies the email address of the server administrator.
11971 Defaults to @samp{"root@@localhost.localdomain"}.
11974 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
11975 The ServerAlias directive is used for HTTP Host header validation when
11976 clients connect to the scheduler from external interfaces. Using the
11977 special name @code{*} can expose your system to known browser-based DNS
11978 rebinding attacks, even when accessing sites through a firewall. If the
11979 auto-discovery of alternate names does not work, we recommend listing
11980 each alternate name with a ServerAlias directive instead of using
11983 Defaults to @samp{*}.
11986 @deftypevr {@code{cups-configuration} parameter} string server-name
11987 Specifies the fully-qualified host name of the server.
11989 Defaults to @samp{"localhost"}.
11992 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
11993 Specifies what information is included in the Server header of HTTP
11994 responses. @code{None} disables the Server header. @code{ProductOnly}
11995 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
11996 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
11997 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
11998 the output of the @code{uname} command. @code{Full} reports @code{CUPS
11999 2.0.0 (@var{uname}) IPP/2.0}.
12001 Defaults to @samp{Minimal}.
12004 @deftypevr {@code{cups-configuration} parameter} string set-env
12005 Set the specified environment variable to be passed to child processes.
12007 Defaults to @samp{"variable value"}.
12010 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
12011 Listens on the specified interfaces for encrypted connections. Valid
12012 values are of the form @var{address}:@var{port}, where @var{address} is
12013 either an IPv6 address enclosed in brackets, an IPv4 address, or
12014 @code{*} to indicate all addresses.
12016 Defaults to @samp{()}.
12019 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
12020 Sets encryption options. By default, CUPS only supports encryption
12021 using TLS v1.0 or higher using known secure cipher suites. The
12022 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
12023 required for some older clients that do not implement newer ones. The
12024 @code{AllowSSL3} option enables SSL v3.0, which is required for some
12025 older clients that do not support TLS v1.0.
12027 Defaults to @samp{()}.
12030 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
12031 Specifies whether the scheduler requires clients to strictly adhere to
12032 the IPP specifications.
12034 Defaults to @samp{#f}.
12037 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
12038 Specifies the HTTP request timeout, in seconds.
12040 Defaults to @samp{300}.
12044 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
12045 Specifies whether the web interface is enabled.
12047 Defaults to @samp{#f}.
12050 At this point you're probably thinking ``oh dear, Guix manual, I like
12051 you but you can stop already with the configuration options''. Indeed.
12052 However, one more point: it could be that you have an existing
12053 @code{cupsd.conf} that you want to use. In that case, you can pass an
12054 @code{opaque-cups-configuration} as the configuration of a
12055 @code{cups-service-type}.
12057 Available @code{opaque-cups-configuration} fields are:
12059 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
12063 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
12064 The contents of the @code{cupsd.conf}, as a string.
12067 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
12068 The contents of the @code{cups-files.conf} file, as a string.
12071 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
12072 strings of the same name, you could instantiate a CUPS service like
12076 (service cups-service-type
12077 (opaque-cups-configuration
12078 (cupsd.conf cupsd.conf)
12079 (cups-files.conf cups-files.conf)))
12083 @node Desktop Services
12084 @subsubsection Desktop Services
12086 The @code{(gnu services desktop)} module provides services that are
12087 usually useful in the context of a ``desktop'' setup---that is, on a
12088 machine running a graphical display server, possibly with graphical user
12089 interfaces, etc. It also defines services that provide specific desktop
12090 environments like GNOME and XFCE.
12092 To simplify things, the module defines a variable containing the set of
12093 services that users typically expect on a machine with a graphical
12094 environment and networking:
12096 @defvr {Scheme Variable} %desktop-services
12097 This is a list of services that builds upon @var{%base-services} and
12098 adds or adjusts services for a typical ``desktop'' setup.
12100 In particular, it adds a graphical login manager (@pxref{X Window,
12101 @code{slim-service}}), screen lockers, a network management tool
12102 (@pxref{Networking Services, @code{network-manager-service-type}}), energy and color
12103 management services, the @code{elogind} login and seat manager, the
12104 Polkit privilege service, the GeoClue location service, the
12105 AccountsService daemon that allows authorized users change system
12106 passwords, an NTP client (@pxref{Networking Services}), the Avahi
12107 daemon, and has the name service switch service configured to be able to
12108 use @code{nss-mdns} (@pxref{Name Service Switch, mDNS}).
12111 The @var{%desktop-services} variable can be used as the @code{services}
12112 field of an @code{operating-system} declaration (@pxref{operating-system
12113 Reference, @code{services}}).
12115 Additionally, the @code{gnome-desktop-service} and
12116 @code{xfce-desktop-service} procedures can add GNOME and/or XFCE to a
12117 system. To ``add GNOME'' means that system-level services like the
12118 backlight adjustment helpers and the power management utilities are
12119 added to the system, extending @code{polkit} and @code{dbus}
12120 appropriately, allowing GNOME to operate with elevated privileges on a
12121 limited number of special-purpose system interfaces. Additionally,
12122 adding a service made by @code{gnome-desktop-service} adds the GNOME
12123 metapackage to the system profile. Likewise, adding the XFCE service
12124 not only adds the @code{xfce} metapackage to the system profile, but it
12125 also gives the Thunar file manager the ability to open a ``root-mode''
12126 file management window, if the user authenticates using the
12127 administrator's password via the standard polkit graphical interface.
12129 @deffn {Scheme Procedure} gnome-desktop-service
12130 Return a service that adds the @code{gnome} package to the system
12131 profile, and extends polkit with the actions from
12132 @code{gnome-settings-daemon}.
12135 @deffn {Scheme Procedure} xfce-desktop-service
12136 Return a service that adds the @code{xfce} package to the system profile,
12137 and extends polkit with the ability for @code{thunar} to manipulate the
12138 file system as root from within a user session, after the user has
12139 authenticated with the administrator's password.
12142 Because the GNOME and XFCE desktop services pull in so many packages,
12143 the default @code{%desktop-services} variable doesn't include either of
12144 them by default. To add GNOME or XFCE, just @code{cons} them onto
12145 @code{%desktop-services} in the @code{services} field of your
12146 @code{operating-system}:
12149 (use-modules (gnu))
12150 (use-service-modules desktop)
12153 ;; cons* adds items to the list given as its last argument.
12154 (services (cons* (gnome-desktop-service)
12155 (xfce-desktop-service)
12156 %desktop-services))
12160 These desktop environments will then be available as options in the
12161 graphical login window.
12163 The actual service definitions included in @code{%desktop-services} and
12164 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
12165 are described below.
12167 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
12168 Return a service that runs the ``system bus'', using @var{dbus}, with
12169 support for @var{services}.
12171 @uref{http://dbus.freedesktop.org/, D-Bus} is an inter-process communication
12172 facility. Its system bus is used to allow system services to communicate
12173 and to be notified of system-wide events.
12175 @var{services} must be a list of packages that provide an
12176 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
12177 and policy files. For example, to allow avahi-daemon to use the system bus,
12178 @var{services} must be equal to @code{(list avahi)}.
12181 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
12182 Return a service that runs the @code{elogind} login and
12183 seat management daemon. @uref{https://github.com/elogind/elogind,
12184 Elogind} exposes a D-Bus interface that can be used to know which users
12185 are logged in, know what kind of sessions they have open, suspend the
12186 system, inhibit system suspend, reboot the system, and other tasks.
12188 Elogind handles most system-level power events for a computer, for
12189 example suspending the system when a lid is closed, or shutting it down
12190 when the power button is pressed.
12192 The @var{config} keyword argument specifies the configuration for
12193 elogind, and should be the result of an @code{(elogind-configuration
12194 (@var{parameter} @var{value})...)} invocation. Available parameters and
12195 their default values are:
12198 @item kill-user-processes?
12200 @item kill-only-users
12202 @item kill-exclude-users
12204 @item inhibit-delay-max-seconds
12206 @item handle-power-key
12208 @item handle-suspend-key
12210 @item handle-hibernate-key
12212 @item handle-lid-switch
12214 @item handle-lid-switch-docked
12216 @item power-key-ignore-inhibited?
12218 @item suspend-key-ignore-inhibited?
12220 @item hibernate-key-ignore-inhibited?
12222 @item lid-switch-ignore-inhibited?
12224 @item holdoff-timeout-seconds
12228 @item idle-action-seconds
12230 @item runtime-directory-size-percent
12232 @item runtime-directory-size
12236 @item suspend-state
12237 @code{("mem" "standby" "freeze")}
12240 @item hibernate-state
12242 @item hibernate-mode
12243 @code{("platform" "shutdown")}
12244 @item hybrid-sleep-state
12246 @item hybrid-sleep-mode
12247 @code{("suspend" "platform" "shutdown")}
12251 @deffn {Scheme Procedure} accountsservice-service @
12252 [#:accountsservice @var{accountsservice}]
12253 Return a service that runs AccountsService, a system service that can
12254 list available accounts, change their passwords, and so on.
12255 AccountsService integrates with PolicyKit to enable unprivileged users
12256 to acquire the capability to modify their system configuration.
12257 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
12258 accountsservice web site} for more information.
12260 The @var{accountsservice} keyword argument is the @code{accountsservice}
12261 package to expose as a service.
12264 @deffn {Scheme Procedure} polkit-service @
12265 [#:polkit @var{polkit}]
12266 Return a service that runs the
12267 @uref{http://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
12268 management service}, which allows system administrators to grant access to
12269 privileged operations in a structured way. By querying the Polkit service, a
12270 privileged system component can know when it should grant additional
12271 capabilities to ordinary users. For example, an ordinary user can be granted
12272 the capability to suspend the system if the user is logged in locally.
12275 @deffn {Scheme Procedure} upower-service [#:upower @var{upower}] @
12276 [#:watts-up-pro? #f] @
12277 [#:poll-batteries? #t] @
12278 [#:ignore-lid? #f] @
12279 [#:use-percentage-for-policy? #f] @
12280 [#:percentage-low 10] @
12281 [#:percentage-critical 3] @
12282 [#:percentage-action 2] @
12283 [#:time-low 1200] @
12284 [#:time-critical 300] @
12285 [#:time-action 120] @
12286 [#:critical-power-action 'hybrid-sleep]
12287 Return a service that runs @uref{http://upower.freedesktop.org/,
12288 @command{upowerd}}, a system-wide monitor for power consumption and battery
12289 levels, with the given configuration settings. It implements the
12290 @code{org.freedesktop.UPower} D-Bus interface, and is notably used by
12294 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
12295 Return a service for @uref{http://udisks.freedesktop.org/docs/latest/,
12296 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
12297 notifications and ways to mount/unmount disks. Programs that talk to UDisks
12298 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
12301 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
12302 Return a service that runs @command{colord}, a system service with a D-Bus
12303 interface to manage the color profiles of input and output devices such as
12304 screens and scanners. It is notably used by the GNOME Color Manager graphical
12305 tool. See @uref{http://www.freedesktop.org/software/colord/, the colord web
12306 site} for more information.
12309 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
12310 Return a configuration allowing an application to access GeoClue
12311 location data. @var{name} is the Desktop ID of the application, without
12312 the @code{.desktop} part. If @var{allowed?} is true, the application
12313 will have access to location information by default. The boolean
12314 @var{system?} value indicates whether an application is a system component
12315 or not. Finally @var{users} is a list of UIDs of all users for which
12316 this application is allowed location info access. An empty users list
12317 means that all users are allowed.
12320 @defvr {Scheme Variable} %standard-geoclue-applications
12321 The standard list of well-known GeoClue application configurations,
12322 granting authority to the GNOME date-and-time utility to ask for the
12323 current location in order to set the time zone, and allowing the
12324 IceCat and Epiphany web browsers to request location information.
12325 IceCat and Epiphany both query the user before allowing a web page to
12326 know the user's location.
12329 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
12330 [#:whitelist '()] @
12331 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
12332 [#:submit-data? #f]
12333 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
12334 [#:submission-nick "geoclue"] @
12335 [#:applications %standard-geoclue-applications]
12336 Return a service that runs the GeoClue location service. This service
12337 provides a D-Bus interface to allow applications to request access to a
12338 user's physical location, and optionally to add information to online
12339 location databases. See
12340 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
12341 web site} for more information.
12344 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
12345 [@w{#:auto-enable? #f}]
12346 Return a service that runs the @command{bluetoothd} daemon, which
12347 manages all the Bluetooth devices and provides a number of D-Bus
12348 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
12349 powered automatically at boot, which can be useful when using a
12350 bluetooth keyboard or mouse.
12352 Users need to be in the @code{lp} group to access the D-Bus service.
12355 @node Database Services
12356 @subsubsection Database Services
12360 The @code{(gnu services databases)} module provides the following services.
12362 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
12363 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
12364 [#:port 5432] [#:locale ``en_US.utf8'']
12365 Return a service that runs @var{postgresql}, the PostgreSQL database
12368 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
12369 creates a database cluster with @var{locale} as the default
12370 locale, stored in @var{data-directory}. It then listens on @var{port}.
12373 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
12374 Return a service that runs @command{mysqld}, the MySQL or MariaDB
12377 The optional @var{config} argument specifies the configuration for
12378 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
12381 @deftp {Data Type} mysql-configuration
12382 Data type representing the configuration of @var{mysql-service}.
12385 @item @code{mysql} (default: @var{mariadb})
12386 Package object of the MySQL database server, can be either @var{mariadb}
12389 For MySQL, a temporary root password will be displayed at activation time.
12390 For MariaDB, the root password is empty.
12392 @item @code{port} (default: @code{3306})
12393 TCP port on which the database server listens for incoming connections.
12397 @defvr {Scheme Variable} memcached-service-type
12398 This is the service type for the @uref{https://memcached.org/,
12399 Memcached} service, which provides a distributed in memory cache. The
12400 value for the service type is a @code{memcached-configuration} object.
12404 (service memcached-service-type)
12407 @deftp {Data Type} memcached-configuration
12408 Data type representing the configuration of memcached.
12411 @item @code{memcached} (default: @code{memcached})
12412 The Memcached package to use.
12414 @item @code{interfaces} (default: @code{'("0.0.0.0")})
12415 Network interfaces on which to listen.
12417 @item @code{tcp-port} (default: @code{11211})
12418 Port on which to accept connections on,
12420 @item @code{udp-port} (default: @code{11211})
12421 Port on which to accept UDP connections on, a value of 0 will disable
12422 listening on a UDP socket.
12424 @item @code{additional-options} (default: @code{'()})
12425 Additional command line options to pass to @code{memcached}.
12429 @defvr {Scheme Variable} mongodb-service-type
12430 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
12431 The value for the service type is a @code{mongodb-configuration} object.
12435 (service mongodb-service-type)
12438 @deftp {Data Type} mongodb-configuration
12439 Data type representing the configuration of mongodb.
12442 @item @code{mongodb} (default: @code{mongodb})
12443 The MongoDB package to use.
12445 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
12446 The configuration file for MongoDB.
12448 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
12449 This value is used to create the directory, so that it exists and is
12450 owned by the mongodb user. It should match the data-directory which
12451 MongoDB is configured to use through the configuration file.
12455 @defvr {Scheme Variable} redis-service-type
12456 This is the service type for the @uref{https://redis.io/, Redis}
12457 key/value store, whose value is a @code{redis-configuration} object.
12460 @deftp {Data Type} redis-configuration
12461 Data type representing the configuration of redis.
12464 @item @code{redis} (default: @code{redis})
12465 The Redis package to use.
12467 @item @code{bind} (default: @code{"127.0.0.1"})
12468 Network interface on which to listen.
12470 @item @code{port} (default: @code{6379})
12471 Port on which to accept connections on, a value of 0 will disable
12472 listening on a TCP socket.
12474 @item @code{working-directory} (default: @code{"/var/lib/redis"})
12475 Directory in which to store the database and related files.
12479 @node Mail Services
12480 @subsubsection Mail Services
12484 The @code{(gnu services mail)} module provides Guix service definitions
12485 for email services: IMAP, POP3, and LMTP servers, as well as mail
12486 transport agents (MTAs). Lots of acronyms! These services are detailed
12487 in the subsections below.
12489 @subsubheading Dovecot Service
12491 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
12492 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
12495 By default, Dovecot does not need much configuration; the default
12496 configuration object created by @code{(dovecot-configuration)} will
12497 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
12498 certificate will be generated for TLS-protected connections, though
12499 Dovecot will also listen on cleartext ports by default. There are a
12500 number of options, though, which mail administrators might need to change,
12501 and as is the case with other services, Guix allows the system
12502 administrator to specify these parameters via a uniform Scheme interface.
12504 For example, to specify that mail is located at @code{maildir~/.mail},
12505 one would instantiate the Dovecot service like this:
12508 (dovecot-service #:config
12509 (dovecot-configuration
12510 (mail-location "maildir:~/.mail")))
12513 The available configuration parameters follow. Each parameter
12514 definition is preceded by its type; for example, @samp{string-list foo}
12515 indicates that the @code{foo} parameter should be specified as a list of
12516 strings. There is also a way to specify the configuration as a string,
12517 if you have an old @code{dovecot.conf} file that you want to port over
12518 from some other system; see the end for more details.
12520 @c The following documentation was initially generated by
12521 @c (generate-documentation) in (gnu services mail). Manually maintained
12522 @c documentation is better, so we shouldn't hesitate to edit below as
12523 @c needed. However if the change you want to make to this documentation
12524 @c can be done in an automated way, it's probably easier to change
12525 @c (generate-documentation) than to make it below and have to deal with
12526 @c the churn as dovecot updates.
12528 Available @code{dovecot-configuration} fields are:
12530 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
12531 The dovecot package.
12534 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
12535 A list of IPs or hosts where to listen for connections. @samp{*}
12536 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
12537 interfaces. If you want to specify non-default ports or anything more
12538 complex, customize the address and port fields of the
12539 @samp{inet-listener} of the specific services you are interested in.
12542 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
12543 List of protocols we want to serve. Available protocols include
12544 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
12546 Available @code{protocol-configuration} fields are:
12548 @deftypevr {@code{protocol-configuration} parameter} string name
12549 The name of the protocol.
12552 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
12553 UNIX socket path to the master authentication server to find users.
12554 This is used by imap (for shared users) and lda.
12555 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
12558 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
12559 Space separated list of plugins to load.
12562 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
12563 Maximum number of IMAP connections allowed for a user from each IP
12564 address. NOTE: The username is compared case-sensitively.
12565 Defaults to @samp{10}.
12570 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
12571 List of services to enable. Available services include @samp{imap},
12572 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
12575 Available @code{service-configuration} fields are:
12577 @deftypevr {@code{service-configuration} parameter} string kind
12578 The service kind. Valid values include @code{director},
12579 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
12580 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
12581 @code{tcpwrap}, @code{quota-warning}, or anything else.
12584 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
12585 Listeners for the service. A listener is either a
12586 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
12587 an @code{inet-listener-configuration}.
12588 Defaults to @samp{()}.
12590 Available @code{unix-listener-configuration} fields are:
12592 @deftypevr {@code{unix-listener-configuration} parameter} string path
12593 Path to the file, relative to @code{base-dir} field. This is also used as
12597 @deftypevr {@code{unix-listener-configuration} parameter} string mode
12598 The access mode for the socket.
12599 Defaults to @samp{"0600"}.
12602 @deftypevr {@code{unix-listener-configuration} parameter} string user
12603 The user to own the socket.
12604 Defaults to @samp{""}.
12607 @deftypevr {@code{unix-listener-configuration} parameter} string group
12608 The group to own the socket.
12609 Defaults to @samp{""}.
12613 Available @code{fifo-listener-configuration} fields are:
12615 @deftypevr {@code{fifo-listener-configuration} parameter} string path
12616 Path to the file, relative to @code{base-dir} field. This is also used as
12620 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
12621 The access mode for the socket.
12622 Defaults to @samp{"0600"}.
12625 @deftypevr {@code{fifo-listener-configuration} parameter} string user
12626 The user to own the socket.
12627 Defaults to @samp{""}.
12630 @deftypevr {@code{fifo-listener-configuration} parameter} string group
12631 The group to own the socket.
12632 Defaults to @samp{""}.
12636 Available @code{inet-listener-configuration} fields are:
12638 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
12639 The protocol to listen for.
12642 @deftypevr {@code{inet-listener-configuration} parameter} string address
12643 The address on which to listen, or empty for all addresses.
12644 Defaults to @samp{""}.
12647 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
12648 The port on which to listen.
12651 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
12652 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
12654 Defaults to @samp{#t}.
12659 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
12660 Number of connections to handle before starting a new process.
12661 Typically the only useful values are 0 (unlimited) or 1. 1 is more
12662 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
12663 Defaults to @samp{1}.
12666 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
12667 Number of processes to always keep waiting for more connections.
12668 Defaults to @samp{0}.
12671 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
12672 If you set @samp{service-count 0}, you probably need to grow
12674 Defaults to @samp{256000000}.
12679 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
12680 Dict configuration, as created by the @code{dict-configuration}
12683 Available @code{dict-configuration} fields are:
12685 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
12686 A list of key-value pairs that this dict should hold.
12687 Defaults to @samp{()}.
12692 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
12693 A list of passdb configurations, each one created by the
12694 @code{passdb-configuration} constructor.
12696 Available @code{passdb-configuration} fields are:
12698 @deftypevr {@code{passdb-configuration} parameter} string driver
12699 The driver that the passdb should use. Valid values include
12700 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
12702 Defaults to @samp{"pam"}.
12705 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
12706 Space separated list of arguments to the passdb driver.
12707 Defaults to @samp{""}.
12712 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
12713 List of userdb configurations, each one created by the
12714 @code{userdb-configuration} constructor.
12716 Available @code{userdb-configuration} fields are:
12718 @deftypevr {@code{userdb-configuration} parameter} string driver
12719 The driver that the userdb should use. Valid values include
12720 @samp{passwd} and @samp{static}.
12721 Defaults to @samp{"passwd"}.
12724 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
12725 Space separated list of arguments to the userdb driver.
12726 Defaults to @samp{""}.
12729 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
12730 Override fields from passwd.
12731 Defaults to @samp{()}.
12736 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
12737 Plug-in configuration, created by the @code{plugin-configuration}
12741 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
12742 List of namespaces. Each item in the list is created by the
12743 @code{namespace-configuration} constructor.
12745 Available @code{namespace-configuration} fields are:
12747 @deftypevr {@code{namespace-configuration} parameter} string name
12748 Name for this namespace.
12751 @deftypevr {@code{namespace-configuration} parameter} string type
12752 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
12753 Defaults to @samp{"private"}.
12756 @deftypevr {@code{namespace-configuration} parameter} string separator
12757 Hierarchy separator to use. You should use the same separator for
12758 all namespaces or some clients get confused. @samp{/} is usually a good
12759 one. The default however depends on the underlying mail storage
12761 Defaults to @samp{""}.
12764 @deftypevr {@code{namespace-configuration} parameter} string prefix
12765 Prefix required to access this namespace. This needs to be
12766 different for all namespaces. For example @samp{Public/}.
12767 Defaults to @samp{""}.
12770 @deftypevr {@code{namespace-configuration} parameter} string location
12771 Physical location of the mailbox. This is in the same format as
12772 mail_location, which is also the default for it.
12773 Defaults to @samp{""}.
12776 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
12777 There can be only one INBOX, and this setting defines which
12779 Defaults to @samp{#f}.
12782 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
12783 If namespace is hidden, it's not advertised to clients via NAMESPACE
12784 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
12785 useful when converting from another server with different namespaces
12786 which you want to deprecate but still keep working. For example you can
12787 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
12789 Defaults to @samp{#f}.
12792 @deftypevr {@code{namespace-configuration} parameter} boolean list?
12793 Show the mailboxes under this namespace with the LIST command. This
12794 makes the namespace visible for clients that do not support the NAMESPACE
12795 extension. The special @code{children} value lists child mailboxes, but
12796 hides the namespace prefix.
12797 Defaults to @samp{#t}.
12800 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
12801 Namespace handles its own subscriptions. If set to @code{#f}, the
12802 parent namespace handles them. The empty prefix should always have this
12804 Defaults to @samp{#t}.
12807 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
12808 List of predefined mailboxes in this namespace.
12809 Defaults to @samp{()}.
12811 Available @code{mailbox-configuration} fields are:
12813 @deftypevr {@code{mailbox-configuration} parameter} string name
12814 Name for this mailbox.
12817 @deftypevr {@code{mailbox-configuration} parameter} string auto
12818 @samp{create} will automatically create this mailbox.
12819 @samp{subscribe} will both create and subscribe to the mailbox.
12820 Defaults to @samp{"no"}.
12823 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
12824 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
12825 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
12826 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
12827 Defaults to @samp{()}.
12834 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
12835 Base directory where to store runtime data.
12836 Defaults to @samp{"/var/run/dovecot/"}.
12839 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
12840 Greeting message for clients.
12841 Defaults to @samp{"Dovecot ready."}.
12844 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
12845 List of trusted network ranges. Connections from these IPs are
12846 allowed to override their IP addresses and ports (for logging and for
12847 authentication checks). @samp{disable-plaintext-auth} is also ignored
12848 for these networks. Typically you would specify your IMAP proxy servers
12850 Defaults to @samp{()}.
12853 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
12854 List of login access check sockets (e.g. tcpwrap).
12855 Defaults to @samp{()}.
12858 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
12859 Show more verbose process titles (in ps). Currently shows user name
12860 and IP address. Useful for seeing who is actually using the IMAP
12861 processes (e.g. shared mailboxes or if the same uid is used for multiple
12863 Defaults to @samp{#f}.
12866 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
12867 Should all processes be killed when Dovecot master process shuts down.
12868 Setting this to @code{#f} means that Dovecot can be upgraded without
12869 forcing existing client connections to close (although that could also
12870 be a problem if the upgrade is e.g. due to a security fix).
12871 Defaults to @samp{#t}.
12874 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
12875 If non-zero, run mail commands via this many connections to doveadm
12876 server, instead of running them directly in the same process.
12877 Defaults to @samp{0}.
12880 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
12881 UNIX socket or host:port used for connecting to doveadm server.
12882 Defaults to @samp{"doveadm-server"}.
12885 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
12886 List of environment variables that are preserved on Dovecot startup
12887 and passed down to all of its child processes. You can also give
12888 key=value pairs to always set specific settings.
12891 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
12892 Disable LOGIN command and all other plaintext authentications unless
12893 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
12894 matches the local IP (i.e. you're connecting from the same computer),
12895 the connection is considered secure and plaintext authentication is
12896 allowed. See also ssl=required setting.
12897 Defaults to @samp{#t}.
12900 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
12901 Authentication cache size (e.g. @samp{#e10e6}). 0 means it's disabled.
12902 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
12903 for caching to be used.
12904 Defaults to @samp{0}.
12907 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
12908 Time to live for cached data. After TTL expires the cached record
12909 is no longer used, *except* if the main database lookup returns internal
12910 failure. We also try to handle password changes automatically: If
12911 user's previous authentication was successful, but this one wasn't, the
12912 cache isn't used. For now this works only with plaintext
12914 Defaults to @samp{"1 hour"}.
12917 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
12918 TTL for negative hits (user not found, password mismatch).
12919 0 disables caching them completely.
12920 Defaults to @samp{"1 hour"}.
12923 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
12924 List of realms for SASL authentication mechanisms that need them.
12925 You can leave it empty if you don't want to support multiple realms.
12926 Many clients simply use the first one listed here, so keep the default
12928 Defaults to @samp{()}.
12931 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
12932 Default realm/domain to use if none was specified. This is used for
12933 both SASL realms and appending @@domain to username in plaintext
12935 Defaults to @samp{""}.
12938 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
12939 List of allowed characters in username. If the user-given username
12940 contains a character not listed in here, the login automatically fails.
12941 This is just an extra check to make sure user can't exploit any
12942 potential quote escaping vulnerabilities with SQL/LDAP databases. If
12943 you want to allow all characters, set this value to empty.
12944 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
12947 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
12948 Username character translations before it's looked up from
12949 databases. The value contains series of from -> to characters. For
12950 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
12951 translated to @samp{@@}.
12952 Defaults to @samp{""}.
12955 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
12956 Username formatting before it's looked up from databases. You can
12957 use the standard variables here, e.g. %Lu would lowercase the username,
12958 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
12959 change the @samp{@@} into @samp{-AT-}. This translation is done after
12960 @samp{auth-username-translation} changes.
12961 Defaults to @samp{"%Lu"}.
12964 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
12965 If you want to allow master users to log in by specifying the master
12966 username within the normal username string (i.e. not using SASL
12967 mechanism's support for it), you can specify the separator character
12968 here. The format is then <username><separator><master username>.
12969 UW-IMAP uses @samp{*} as the separator, so that could be a good
12971 Defaults to @samp{""}.
12974 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
12975 Username to use for users logging in with ANONYMOUS SASL
12977 Defaults to @samp{"anonymous"}.
12980 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
12981 Maximum number of dovecot-auth worker processes. They're used to
12982 execute blocking passdb and userdb queries (e.g. MySQL and PAM).
12983 They're automatically created and destroyed as needed.
12984 Defaults to @samp{30}.
12987 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
12988 Host name to use in GSSAPI principal names. The default is to use
12989 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
12990 allow all keytab entries.
12991 Defaults to @samp{""}.
12994 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
12995 Kerberos keytab to use for the GSSAPI mechanism. Will use the
12996 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
12997 need to change the auth service to run as root to be able to read this
12999 Defaults to @samp{""}.
13002 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
13003 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
13004 and @samp{ntlm-auth} helper.
13005 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
13006 Defaults to @samp{#f}.
13009 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
13010 Path for Samba's @samp{ntlm-auth} helper binary.
13011 Defaults to @samp{"/usr/bin/ntlm_auth"}.
13014 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
13015 Time to delay before replying to failed authentications.
13016 Defaults to @samp{"2 secs"}.
13019 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
13020 Require a valid SSL client certificate or the authentication
13022 Defaults to @samp{#f}.
13025 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
13026 Take the username from client's SSL certificate, using
13027 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
13029 Defaults to @samp{#f}.
13032 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
13033 List of wanted authentication mechanisms. Supported mechanisms are:
13034 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
13035 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
13036 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
13037 @samp{disable-plaintext-auth} setting.
13040 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
13041 List of IPs or hostnames to all director servers, including ourself.
13042 Ports can be specified as ip:port. The default port is the same as what
13043 director service's @samp{inet-listener} is using.
13044 Defaults to @samp{()}.
13047 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
13048 List of IPs or hostnames to all backend mail servers. Ranges are
13049 allowed too, like 10.0.0.10-10.0.0.30.
13050 Defaults to @samp{()}.
13053 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
13054 How long to redirect users to a specific server after it no longer
13055 has any connections.
13056 Defaults to @samp{"15 min"}.
13059 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer director-doveadm-port
13060 TCP/IP port that accepts doveadm connections (instead of director
13061 connections) If you enable this, you'll also need to add
13062 @samp{inet-listener} for the port.
13063 Defaults to @samp{0}.
13066 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
13067 How the username is translated before being hashed. Useful values
13068 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
13069 are shared within domain.
13070 Defaults to @samp{"%Lu"}.
13073 @deftypevr {@code{dovecot-configuration} parameter} string log-path
13074 Log file to use for error messages. @samp{syslog} logs to syslog,
13075 @samp{/dev/stderr} logs to stderr.
13076 Defaults to @samp{"syslog"}.
13079 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
13080 Log file to use for informational messages. Defaults to
13082 Defaults to @samp{""}.
13085 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
13086 Log file to use for debug messages. Defaults to
13087 @samp{info-log-path}.
13088 Defaults to @samp{""}.
13091 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
13092 Syslog facility to use if you're logging to syslog. Usually if you
13093 don't want to use @samp{mail}, you'll use local0..local7. Also other
13094 standard facilities are supported.
13095 Defaults to @samp{"mail"}.
13098 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
13099 Log unsuccessful authentication attempts and the reasons why they
13101 Defaults to @samp{#f}.
13104 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose-passwords?
13105 In case of password mismatches, log the attempted password. Valid
13106 values are no, plain and sha1. sha1 can be useful for detecting brute
13107 force password attempts vs. user simply trying the same password over
13108 and over again. You can also truncate the value to n chars by appending
13109 ":n" (e.g. sha1:6).
13110 Defaults to @samp{#f}.
13113 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
13114 Even more verbose logging for debugging purposes. Shows for example
13116 Defaults to @samp{#f}.
13119 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
13120 In case of password mismatches, log the passwords and used scheme so
13121 the problem can be debugged. Enabling this also enables
13123 Defaults to @samp{#f}.
13126 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
13127 Enable mail process debugging. This can help you figure out why
13128 Dovecot isn't finding your mails.
13129 Defaults to @samp{#f}.
13132 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
13133 Show protocol level SSL errors.
13134 Defaults to @samp{#f}.
13137 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
13138 Prefix for each line written to log file. % codes are in
13139 strftime(3) format.
13140 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
13143 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
13144 List of elements we want to log. The elements which have a
13145 non-empty variable value are joined together to form a comma-separated
13149 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
13150 Login log format. %s contains @samp{login-log-format-elements}
13151 string, %$ contains the data we want to log.
13152 Defaults to @samp{"%$: %s"}.
13155 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
13156 Log prefix for mail processes. See doc/wiki/Variables.txt for list
13157 of possible variables you can use.
13158 Defaults to @samp{"\"%s(%u): \""}.
13161 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
13162 Format to use for logging mail deliveries. You can use variables:
13165 Delivery status message (e.g. @samp{saved to INBOX})
13177 Defaults to @samp{"msgid=%m: %$"}.
13180 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
13181 Location for users' mailboxes. The default is empty, which means
13182 that Dovecot tries to find the mailboxes automatically. This won't work
13183 if the user doesn't yet have any mail, so you should explicitly tell
13184 Dovecot the full location.
13186 If you're using mbox, giving a path to the INBOX
13187 file (e.g. /var/mail/%u) isn't enough. You'll also need to tell Dovecot
13188 where the other mailboxes are kept. This is called the "root mail
13189 directory", and it must be the first path given in the
13190 @samp{mail-location} setting.
13192 There are a few special variables you can use, eg.:
13198 user part in user@@domain, same as %u if there's no domain
13200 domain part in user@@domain, empty if there's no domain
13205 See doc/wiki/Variables.txt for full list. Some examples:
13207 @item maildir:~/Maildir
13208 @item mbox:~/mail:INBOX=/var/mail/%u
13209 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
13211 Defaults to @samp{""}.
13214 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
13215 System user and group used to access mails. If you use multiple,
13216 userdb can override these by returning uid or gid fields. You can use
13217 either numbers or names. <doc/wiki/UserIds.txt>.
13218 Defaults to @samp{""}.
13221 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
13223 Defaults to @samp{""}.
13226 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
13227 Group to enable temporarily for privileged operations. Currently
13228 this is used only with INBOX when either its initial creation or
13229 dotlocking fails. Typically this is set to "mail" to give access to
13231 Defaults to @samp{""}.
13234 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
13235 Grant access to these supplementary groups for mail processes.
13236 Typically these are used to set up access to shared mailboxes. Note
13237 that it may be dangerous to set these if users can create
13238 symlinks (e.g. if "mail" group is set here, ln -s /var/mail ~/mail/var
13239 could allow a user to delete others' mailboxes, or ln -s
13240 /secret/shared/box ~/mail/mybox would allow reading it).
13241 Defaults to @samp{""}.
13244 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
13245 Allow full file system access to clients. There's no access checks
13246 other than what the operating system does for the active UID/GID. It
13247 works with both maildir and mboxes, allowing you to prefix mailboxes
13248 names with e.g. /path/ or ~user/.
13249 Defaults to @samp{#f}.
13252 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
13253 Don't use mmap() at all. This is required if you store indexes to
13254 shared file systems (NFS or clustered file system).
13255 Defaults to @samp{#f}.
13258 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
13259 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
13260 supports @samp{O_EXCL} since version 3, so this should be safe to use
13261 nowadays by default.
13262 Defaults to @samp{#t}.
13265 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
13266 When to use fsync() or fdatasync() calls:
13269 Whenever necessary to avoid losing important data
13271 Useful with e.g. NFS when write()s are delayed
13273 Never use it (best performance, but crashes can lose data).
13275 Defaults to @samp{"optimized"}.
13278 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
13279 Mail storage exists in NFS. Set this to yes to make Dovecot flush
13280 NFS caches whenever needed. If you're using only a single mail server
13282 Defaults to @samp{#f}.
13285 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
13286 Mail index files also exist in NFS. Setting this to yes requires
13287 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
13288 Defaults to @samp{#f}.
13291 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
13292 Locking method for index files. Alternatives are fcntl, flock and
13293 dotlock. Dotlocking uses some tricks which may create more disk I/O
13294 than other locking methods. NFS users: flock doesn't work, remember to
13295 change @samp{mmap-disable}.
13296 Defaults to @samp{"fcntl"}.
13299 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
13300 Directory in which LDA/LMTP temporarily stores incoming mails >128
13302 Defaults to @samp{"/tmp"}.
13305 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
13306 Valid UID range for users. This is mostly to make sure that users can't
13307 log in as daemons or other system users. Note that denying root logins is
13308 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
13310 Defaults to @samp{500}.
13313 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
13315 Defaults to @samp{0}.
13318 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
13319 Valid GID range for users. Users having non-valid GID as primary group ID
13320 aren't allowed to log in. If user belongs to supplementary groups with
13321 non-valid GIDs, those groups are not set.
13322 Defaults to @samp{1}.
13325 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
13327 Defaults to @samp{0}.
13330 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
13331 Maximum allowed length for mail keyword name. It's only forced when
13332 trying to create new keywords.
13333 Defaults to @samp{50}.
13336 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
13337 List of directories under which chrooting is allowed for mail
13338 processes (i.e. /var/mail will allow chrooting to /var/mail/foo/bar
13339 too). This setting doesn't affect @samp{login-chroot}
13340 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
13341 "/./" in home dirs are ignored. WARNING: Never add directories here
13342 which local users can modify, that may lead to root exploit. Usually
13343 this should be done only if you don't allow shell access for users.
13344 <doc/wiki/Chrooting.txt>.
13345 Defaults to @samp{()}.
13348 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
13349 Default chroot directory for mail processes. This can be overridden
13350 for specific users in user database by giving /./ in user's home
13351 directory (e.g. /home/./user chroots into /home). Note that usually
13352 there is no real need to do chrooting, Dovecot doesn't allow users to
13353 access files outside their mail directory anyway. If your home
13354 directories are prefixed with the chroot directory, append "/." to
13355 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
13356 Defaults to @samp{""}.
13359 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
13360 UNIX socket path to master authentication server to find users.
13361 This is used by imap (for shared users) and lda.
13362 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
13365 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
13366 Directory where to look up mail plugins.
13367 Defaults to @samp{"/usr/lib/dovecot"}.
13370 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
13371 List of plugins to load for all services. Plugins specific to IMAP,
13372 LDA, etc. are added to this list in their own .conf files.
13373 Defaults to @samp{()}.
13376 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
13377 The minimum number of mails in a mailbox before updates are done to
13378 cache file. This allows optimizing Dovecot's behavior to do less disk
13379 writes at the cost of more disk reads.
13380 Defaults to @samp{0}.
13383 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
13384 When IDLE command is running, mailbox is checked once in a while to
13385 see if there are any new mails or other changes. This setting defines
13386 the minimum time to wait between those checks. Dovecot can also use
13387 dnotify, inotify and kqueue to find out immediately when changes
13389 Defaults to @samp{"30 secs"}.
13392 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
13393 Save mails with CR+LF instead of plain LF. This makes sending those
13394 mails take less CPU, especially with sendfile() syscall with Linux and
13395 FreeBSD. But it also creates a bit more disk I/O which may just make it
13396 slower. Also note that if other software reads the mboxes/maildirs,
13397 they may handle the extra CRs wrong and cause problems.
13398 Defaults to @samp{#f}.
13401 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
13402 By default LIST command returns all entries in maildir beginning
13403 with a dot. Enabling this option makes Dovecot return only entries
13404 which are directories. This is done by stat()ing each entry, so it
13405 causes more disk I/O.
13406 (For systems setting struct @samp{dirent->d_type} this check is free
13407 and it's done always regardless of this setting).
13408 Defaults to @samp{#f}.
13411 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
13412 When copying a message, do it with hard links whenever possible.
13413 This makes the performance much better, and it's unlikely to have any
13415 Defaults to @samp{#t}.
13418 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
13419 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
13420 directory only when its mtime changes unexpectedly or when we can't find
13421 the mail otherwise.
13422 Defaults to @samp{#f}.
13425 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
13426 Which locking methods to use for locking mbox. There are four
13431 Create <mailbox>.lock file. This is the oldest and most NFS-safe
13432 solution. If you want to use /var/mail/ like directory, the users will
13433 need write access to that directory.
13435 Same as dotlock, but if it fails because of permissions or because there
13436 isn't enough disk space, just skip it.
13438 Use this if possible. Works with NFS too if lockd is used.
13440 May not exist in all systems. Doesn't work with NFS.
13442 May not exist in all systems. Doesn't work with NFS.
13445 You can use multiple locking methods; if you do the order they're declared
13446 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
13447 locking methods as well. Some operating systems don't allow using some of
13448 them simultaneously.
13451 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
13455 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
13456 Maximum time to wait for lock (all of them) before aborting.
13457 Defaults to @samp{"5 mins"}.
13460 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
13461 If dotlock exists but the mailbox isn't modified in any way,
13462 override the lock file after this much time.
13463 Defaults to @samp{"2 mins"}.
13466 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
13467 When mbox changes unexpectedly we have to fully read it to find out
13468 what changed. If the mbox is large this can take a long time. Since
13469 the change is usually just a newly appended mail, it'd be faster to
13470 simply read the new mails. If this setting is enabled, Dovecot does
13471 this but still safely fallbacks to re-reading the whole mbox file
13472 whenever something in mbox isn't how it's expected to be. The only real
13473 downside to this setting is that if some other MUA changes message
13474 flags, Dovecot doesn't notice it immediately. Note that a full sync is
13475 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
13476 Defaults to @samp{#t}.
13479 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
13480 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
13481 EXAMINE, EXPUNGE or CHECK commands. If this is set,
13482 @samp{mbox-dirty-syncs} is ignored.
13483 Defaults to @samp{#f}.
13486 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
13487 Delay writing mbox headers until doing a full write sync (EXPUNGE
13488 and CHECK commands and when closing the mailbox). This is especially
13489 useful for POP3 where clients often delete all mails. The downside is
13490 that our changes aren't immediately visible to other MUAs.
13491 Defaults to @samp{#t}.
13494 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
13495 If mbox size is smaller than this (e.g. 100k), don't write index
13496 files. If an index file already exists it's still read, just not
13498 Defaults to @samp{0}.
13501 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
13502 Maximum dbox file size until it's rotated.
13503 Defaults to @samp{2000000}.
13506 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
13507 Maximum dbox file age until it's rotated. Typically in days. Day
13508 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
13510 Defaults to @samp{"1d"}.
13513 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
13514 When creating new mdbox files, immediately preallocate their size to
13515 @samp{mdbox-rotate-size}. This setting currently works only in Linux
13516 with some file systems (ext4, xfs).
13517 Defaults to @samp{#f}.
13520 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
13521 sdbox and mdbox support saving mail attachments to external files,
13522 which also allows single instance storage for them. Other backends
13523 don't support this for now.
13525 WARNING: This feature hasn't been tested much yet. Use at your own risk.
13527 Directory root where to store mail attachments. Disabled, if empty.
13528 Defaults to @samp{""}.
13531 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
13532 Attachments smaller than this aren't saved externally. It's also
13533 possible to write a plugin to disable saving specific attachments
13535 Defaults to @samp{128000}.
13538 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
13539 File system backend to use for saving attachments:
13542 No SiS done by Dovecot (but this might help FS's own deduplication)
13544 SiS with immediate byte-by-byte comparison during saving
13545 @item sis-queue posix
13546 SiS with delayed comparison and deduplication.
13548 Defaults to @samp{"sis posix"}.
13551 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
13552 Hash format to use in attachment filenames. You can add any text and
13553 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
13554 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
13555 truncated, e.g. @code{%@{sha256:80@}} returns only first 80 bits.
13556 Defaults to @samp{"%@{sha1@}"}.
13559 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
13561 Defaults to @samp{100}.
13564 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
13566 Defaults to @samp{1000}.
13569 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
13570 Default VSZ (virtual memory size) limit for service processes.
13571 This is mainly intended to catch and kill processes that leak memory
13572 before they eat up everything.
13573 Defaults to @samp{256000000}.
13576 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
13577 Login user is internally used by login processes. This is the most
13578 untrusted user in Dovecot system. It shouldn't have access to anything
13580 Defaults to @samp{"dovenull"}.
13583 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
13584 Internal user is used by unprivileged processes. It should be
13585 separate from login user, so that login processes can't disturb other
13587 Defaults to @samp{"dovecot"}.
13590 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
13591 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
13592 Defaults to @samp{"required"}.
13595 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
13596 PEM encoded X.509 SSL/TLS certificate (public key).
13597 Defaults to @samp{"</etc/dovecot/default.pem"}.
13600 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
13601 PEM encoded SSL/TLS private key. The key is opened before
13602 dropping root privileges, so keep the key file unreadable by anyone but
13604 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
13607 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
13608 If key file is password protected, give the password here.
13609 Alternatively give it when starting dovecot with -p parameter. Since
13610 this file is often world-readable, you may want to place this setting
13611 instead to a different.
13612 Defaults to @samp{""}.
13615 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
13616 PEM encoded trusted certificate authority. Set this only if you
13617 intend to use @samp{ssl-verify-client-cert? #t}. The file should
13618 contain the CA certificate(s) followed by the matching
13619 CRL(s). (e.g. @samp{ssl-ca </etc/ssl/certs/ca.pem}).
13620 Defaults to @samp{""}.
13623 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
13624 Require that CRL check succeeds for client certificates.
13625 Defaults to @samp{#t}.
13628 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
13629 Request client to send a certificate. If you also want to require
13630 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
13631 Defaults to @samp{#f}.
13634 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
13635 Which field from certificate to use for username. commonName and
13636 x500UniqueIdentifier are the usual choices. You'll also need to set
13637 @samp{auth-ssl-username-from-cert? #t}.
13638 Defaults to @samp{"commonName"}.
13641 @deftypevr {@code{dovecot-configuration} parameter} hours ssl-parameters-regenerate
13642 How often to regenerate the SSL parameters file. Generation is
13643 quite CPU intensive operation. The value is in hours, 0 disables
13644 regeneration entirely.
13645 Defaults to @samp{168}.
13648 @deftypevr {@code{dovecot-configuration} parameter} string ssl-protocols
13649 SSL protocols to use.
13650 Defaults to @samp{"!SSLv2"}.
13653 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
13654 SSL ciphers to use.
13655 Defaults to @samp{"ALL:!LOW:!SSLv2:!EXP:!aNULL"}.
13658 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
13659 SSL crypto device to use, for valid values run "openssl engine".
13660 Defaults to @samp{""}.
13663 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
13664 Address to use when sending rejection mails.
13665 %d expands to recipient domain.
13666 Defaults to @samp{"postmaster@@%d"}.
13669 @deftypevr {@code{dovecot-configuration} parameter} string hostname
13670 Hostname to use in various parts of sent mails (e.g. in Message-Id)
13671 and in LMTP replies. Default is the system's real hostname@@domain.
13672 Defaults to @samp{""}.
13675 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
13676 If user is over quota, return with temporary failure instead of
13678 Defaults to @samp{#f}.
13681 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
13682 Binary to use for sending mails.
13683 Defaults to @samp{"/usr/sbin/sendmail"}.
13686 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
13687 If non-empty, send mails via this SMTP host[:port] instead of
13689 Defaults to @samp{""}.
13692 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
13693 Subject: header to use for rejection mails. You can use the same
13694 variables as for @samp{rejection-reason} below.
13695 Defaults to @samp{"Rejected: %s"}.
13698 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
13699 Human readable error message for rejection mails. You can use
13712 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
13715 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
13716 Delimiter character between local-part and detail in email
13718 Defaults to @samp{"+"}.
13721 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
13722 Header where the original recipient address (SMTP's RCPT TO:
13723 address) is taken from if not available elsewhere. With dovecot-lda -a
13724 parameter overrides this. A commonly used header for this is
13726 Defaults to @samp{""}.
13729 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
13730 Should saving a mail to a nonexistent mailbox automatically create
13732 Defaults to @samp{#f}.
13735 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
13736 Should automatically created mailboxes be also automatically
13738 Defaults to @samp{#f}.
13741 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
13742 Maximum IMAP command line length. Some clients generate very long
13743 command lines with huge mailboxes, so you may need to raise this if you
13744 get "Too long argument" or "IMAP command line too large" errors
13746 Defaults to @samp{64000}.
13749 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
13750 IMAP logout format string:
13753 total number of bytes read from client
13755 total number of bytes sent to client.
13757 Defaults to @samp{"in=%i out=%o"}.
13760 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
13761 Override the IMAP CAPABILITY response. If the value begins with '+',
13762 add the given capabilities on top of the defaults (e.g. +XFOO XBAR).
13763 Defaults to @samp{""}.
13766 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
13767 How long to wait between "OK Still here" notifications when client
13769 Defaults to @samp{"2 mins"}.
13772 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
13773 ID field names and values to send to clients. Using * as the value
13774 makes Dovecot use the default value. The following fields have default
13775 values currently: name, version, os, os-version, support-url,
13777 Defaults to @samp{""}.
13780 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
13781 ID fields sent by client to log. * means everything.
13782 Defaults to @samp{""}.
13785 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
13786 Workarounds for various client bugs:
13789 @item delay-newmail
13790 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
13791 CHECK commands. Some clients ignore them otherwise, for example OSX
13792 Mail (<v2.1). Outlook Express breaks more badly though, without this it
13793 may show user "Message no longer in server" errors. Note that OE6
13794 still breaks even with this workaround if synchronization is set to
13797 @item tb-extra-mailbox-sep
13798 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
13799 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
13800 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
13802 @item tb-lsub-flags
13803 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g. mbox).
13804 This makes Thunderbird realize they aren't selectable and show them
13805 greyed out, instead of only later giving "not selectable" popup error.
13807 Defaults to @samp{()}.
13810 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
13811 Host allowed in URLAUTH URLs sent by client. "*" allows all.
13812 Defaults to @samp{""}.
13816 Whew! Lots of configuration options. The nice thing about it though is
13817 that GuixSD has a complete interface to Dovecot's configuration
13818 language. This allows not only a nice way to declare configurations,
13819 but also offers reflective capabilities as well: users can write code to
13820 inspect and transform configurations from within Scheme.
13822 However, it could be that you just want to get a @code{dovecot.conf} up
13823 and running. In that case, you can pass an
13824 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
13825 @code{dovecot-service}. As its name indicates, an opaque configuration
13826 does not have easy reflective capabilities.
13828 Available @code{opaque-dovecot-configuration} fields are:
13830 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
13831 The dovecot package.
13834 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
13835 The contents of the @code{dovecot.conf}, as a string.
13838 For example, if your @code{dovecot.conf} is just the empty string, you
13839 could instantiate a dovecot service like this:
13842 (dovecot-service #:config
13843 (opaque-dovecot-configuration
13847 @subsubheading OpenSMTPD Service
13849 @deffn {Scheme Variable} opensmtpd-service-type
13850 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
13851 service, whose value should be an @code{opensmtpd-configuration} object
13852 as in this example:
13855 (service opensmtpd-service-type
13856 (opensmtpd-configuration
13857 (config-file (local-file "./my-smtpd.conf"))))
13861 @deftp {Data Type} opensmtpd-configuration
13862 Data type representing the configuration of opensmtpd.
13865 @item @code{package} (default: @var{opensmtpd})
13866 Package object of the OpenSMTPD SMTP server.
13868 @item @code{config-file} (default: @var{%default-opensmtpd-file})
13869 File-like object of the OpenSMTPD configuration file to use. By default
13870 it listens on the loopback network interface, and allows for mail from
13871 users and daemons on the local machine, as well as permitting email to
13872 remote servers. Run @command{man smtpd.conf} for more information.
13877 @subsubheading Exim Service
13879 @cindex mail transfer agent (MTA)
13880 @cindex MTA (mail transfer agent)
13883 @deffn {Scheme Variable} exim-service-type
13884 This is the type of the @uref{https://exim.org, Exim} mail transfer
13885 agent (MTA), whose value should be an @code{exim-configuration} object
13886 as in this example:
13889 (service exim-service-type
13890 (exim-configuration
13891 (config-file (local-file "./my-exim.conf"))))
13895 In order to use an @code{exim-service-type} service you must also have a
13896 @code{mail-aliases-service-type} service present in your
13897 @code{operating-system} (even if it has no aliases).
13899 @deftp {Data Type} exim-configuration
13900 Data type representing the configuration of exim.
13903 @item @code{package} (default: @var{exim})
13904 Package object of the Exim server.
13906 @item @code{config-file} (default: @code{#f})
13907 File-like object of the Exim configuration file to use. If its value is
13908 @code{#f} then use the default configuration file from the package
13909 provided in @code{package}. The resulting configuration file is loaded
13910 after setting the @code{exim_user} and @code{exim_group} configuration
13916 @subsubheading Mail Aliases Service
13918 @cindex email aliases
13919 @cindex aliases, for email addresses
13921 @deffn {Scheme Variable} mail-aliases-service-type
13922 This is the type of the service which provides @code{/etc/aliases},
13923 specifying how to deliver mail to users on this system.
13926 (service mail-aliases-service-type
13927 '(("postmaster" "bob")
13928 ("bob" "bob@@example.com" "bob@@example2.com")))
13932 The configuration for a @code{mail-aliases-service-type} service is an
13933 association list denoting how to deliver mail that comes to this
13934 system. Each entry is of the form @code{(alias addresses ...)}, with
13935 @code{alias} specifying the local alias and @code{addresses} specifying
13936 where to deliver this user's mail.
13938 The aliases aren't required to exist as users on the local system. In
13939 the above example, there doesn't need to be a @code{postmaster} entry in
13940 the @code{operating-system}'s @code{user-accounts} in order to deliver
13941 the @code{postmaster} mail to @code{bob} (which subsequently would
13942 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
13944 @node Messaging Services
13945 @subsubsection Messaging Services
13950 The @code{(gnu services messaging)} module provides Guix service
13951 definitions for messaging services: currently only Prosody is supported.
13953 @subsubheading Prosody Service
13955 @deffn {Scheme Variable} prosody-service-type
13956 This is the type for the @uref{http://prosody.im, Prosody XMPP
13957 communication server}. Its value must be a @code{prosody-configuration}
13958 record as in this example:
13961 (service prosody-service-type
13962 (prosody-configuration
13963 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
13966 (int-component-configuration
13967 (hostname "conference.example.net")
13969 (mod-muc (mod-muc-configuration)))))
13972 (virtualhost-configuration
13973 (domain "example.net"))))))
13976 See below for details about @code{prosody-configuration}.
13980 By default, Prosody does not need much configuration. Only one
13981 @code{virtualhosts} field is needed: it specifies the domain you wish
13984 You can perform various sanity checks on the generated configuration
13985 with the @code{prosodyctl check} command.
13987 Prosodyctl will also help you to import certificates from the
13988 @code{letsencrypt} directory so that the @code{prosody} user can access
13989 them. See @url{https://prosody.im/doc/letsencrypt}.
13992 prosodyctl --root cert import /etc/letsencrypt/live
13995 The available configuration parameters follow. Each parameter
13996 definition is preceded by its type; for example, @samp{string-list foo}
13997 indicates that the @code{foo} parameter should be specified as a list of
13998 strings. Types starting with @code{maybe-} denote parameters that won't
13999 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
14001 There is also a way to specify the configuration as a string, if you
14002 have an old @code{prosody.cfg.lua} file that you want to port over from
14003 some other system; see the end for more details.
14005 @c The following documentation was initially generated by
14006 @c (generate-documentation) in (gnu services messaging). Manually maintained
14007 @c documentation is better, so we shouldn't hesitate to edit below as
14008 @c needed. However if the change you want to make to this documentation
14009 @c can be done in an automated way, it's probably easier to change
14010 @c (generate-documentation) than to make it below and have to deal with
14011 @c the churn as Prosody updates.
14013 Available @code{prosody-configuration} fields are:
14015 @deftypevr {@code{prosody-configuration} parameter} package prosody
14016 The Prosody package.
14019 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
14020 Location of the Prosody data storage directory. See
14021 @url{http://prosody.im/doc/configure}.
14022 Defaults to @samp{"/var/lib/prosody"}.
14025 @deftypevr {@code{prosody-configuration} parameter} file-name-list plugin-paths
14026 Additional plugin directories. They are searched in all the specified
14027 paths in order. See @url{http://prosody.im/doc/plugins_directory}.
14028 Defaults to @samp{()}.
14031 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
14032 Every virtual host and component needs a certificate so that clients and
14033 servers can securely verify its identity. Prosody will automatically load
14034 certificates/keys from the directory specified here.
14035 Defaults to @samp{"/etc/prosody/certs"}.
14038 @deftypevr {@code{prosody-configuration} parameter} string-list admins
14039 This is a list of accounts that are admins for the server. Note that you
14040 must create the accounts separately. See @url{http://prosody.im/doc/admins} and
14041 @url{http://prosody.im/doc/creating_accounts}.
14042 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
14043 Defaults to @samp{()}.
14046 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
14047 Enable use of libevent for better performance under high load. See
14048 @url{http://prosody.im/doc/libevent}.
14049 Defaults to @samp{#f}.
14052 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
14053 This is the list of modules Prosody will load on startup. It looks for
14054 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
14055 Documentation on modules can be found at:
14056 @url{http://prosody.im/doc/modules}.
14057 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
14060 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
14061 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
14062 should you want to disable them then add them to this list.
14063 Defaults to @samp{()}.
14066 @deftypevr {@code{prosody-configuration} parameter} file-name groups-file
14067 Path to a text file where the shared groups are defined. If this path is
14068 empty then @samp{mod_groups} does nothing. See
14069 @url{http://prosody.im/doc/modules/mod_groups}.
14070 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
14073 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
14074 Disable account creation by default, for security. See
14075 @url{http://prosody.im/doc/creating_accounts}.
14076 Defaults to @samp{#f}.
14079 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
14080 These are the SSL/TLS-related settings. Most of them are disabled so to
14081 use Prosody's defaults. If you do not completely understand these options, do
14082 not add them to your config, it is easy to lower the security of your server
14083 using them. See @url{http://prosody.im/doc/advanced_ssl_config}.
14085 Available @code{ssl-configuration} fields are:
14087 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
14088 This determines what handshake to use.
14091 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
14092 Path to your private key file.
14095 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
14096 Path to your certificate file.
14099 @deftypevr {@code{ssl-configuration} parameter} file-name capath
14100 Path to directory containing root certificates that you wish Prosody to
14101 trust when verifying the certificates of remote servers.
14102 Defaults to @samp{"/etc/ssl/certs"}.
14105 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name cafile
14106 Path to a file containing root certificates that you wish Prosody to trust.
14107 Similar to @code{capath} but with all certificates concatenated together.
14110 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
14111 A list of verification options (these mostly map to OpenSSL's
14112 @code{set_verify()} flags).
14115 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
14116 A list of general options relating to SSL/TLS. These map to OpenSSL's
14117 @code{set_options()}. For a full list of options available in LuaSec, see the
14121 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
14122 How long a chain of certificate authorities to check when looking for a
14123 trusted root certificate.
14126 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
14127 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
14128 clients, and in what order.
14131 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
14132 A path to a file containing parameters for Diffie-Hellman key exchange. You
14133 can create such a file with:
14134 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
14137 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
14138 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
14139 @samp{"secp384r1"}.
14142 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
14143 A list of "extra" verification options.
14146 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
14147 Password for encrypted private keys.
14152 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
14153 Whether to force all client-to-server connections to be encrypted or not.
14154 See @url{http://prosody.im/doc/modules/mod_tls}.
14155 Defaults to @samp{#f}.
14158 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
14159 Set of mechanisms that will never be offered. See
14160 @url{https://prosody.im/doc/modules/mod_saslauth}.
14161 Defaults to @samp{("DIGEST-MD5")}.
14164 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
14165 Whether to force all server-to-server connections to be encrypted or not.
14166 See @url{http://prosody.im/doc/modules/mod_tls}.
14167 Defaults to @samp{#f}.
14170 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
14171 Whether to require encryption and certificate authentication. This
14172 provides ideal security, but requires servers you communicate with to support
14173 encryption AND present valid, trusted certificates. See
14174 @url{http://prosody.im/doc/s2s#security}.
14175 Defaults to @samp{#f}.
14178 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
14179 Many servers don't support encryption or have invalid or self-signed
14180 certificates. You can list domains here that will not be required to
14181 authenticate using certificates. They will be authenticated using DNS. See
14182 @url{http://prosody.im/doc/s2s#security}.
14183 Defaults to @samp{()}.
14186 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
14187 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
14188 valid certificates for some domains by specifying a list here. See
14189 @url{http://prosody.im/doc/s2s#security}.
14190 Defaults to @samp{()}.
14193 @deftypevr {@code{prosody-configuration} parameter} string authentication
14194 Select the authentication backend to use. The default provider stores
14195 passwords in plaintext and uses Prosody's configured data storage to store the
14196 authentication data. If you do not trust your server please see
14197 @url{http://prosody.im/doc/modules/mod_auth_internal_hashed} for information
14198 about using the hashed backend. See also
14199 @url{http://prosody.im/doc/authentication}
14200 Defaults to @samp{"internal_plain"}.
14203 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
14204 Set logging options. Advanced logging configuration is not yet supported
14205 by the GuixSD Prosody Service. See @url{http://prosody.im/doc/logging}.
14206 Defaults to @samp{"*syslog"}.
14209 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
14210 File to write pid in. See @url{http://prosody.im/doc/modules/mod_posix}.
14211 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
14214 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
14215 Maximum allowed size of the HTTP body (in bytes).
14218 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
14219 Some modules expose their own URL in various ways. This URL is built
14220 from the protocol, host and port used. If Prosody sits behind a proxy, the
14221 public URL will be @code{http-external-url} instead. See
14222 @url{https://prosody.im/doc/http#external_url}.
14225 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
14226 A host in Prosody is a domain on which user accounts can be created. For
14227 example if you want your users to have addresses like
14228 @samp{"john.smith@@example.com"} then you need to add a host
14229 @samp{"example.com"}. All options in this list will apply only to this host.
14231 Note: the name "virtual" host is used in configuration to avoid confusion with
14232 the actual physical host that Prosody is installed on. A single Prosody
14233 instance can serve many domains, each one defined as a VirtualHost entry in
14234 Prosody's configuration. Conversely a server that hosts a single domain would
14235 have just one VirtualHost entry.
14237 See @url{http://prosody.im/doc/configure#virtual_host_settings}.
14239 Available @code{virtualhost-configuration} fields are:
14241 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:
14242 @deftypevr {@code{virtualhost-configuration} parameter} string domain
14243 Domain you wish Prosody to serve.
14248 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
14249 Components are extra services on a server which are available to clients,
14250 usually on a subdomain of the main server (such as
14251 @samp{"mycomponent.example.com"}). Example components might be chatroom
14252 servers, user directories, or gateways to other protocols.
14254 Internal components are implemented with Prosody-specific plugins. To add an
14255 internal component, you simply fill the hostname field, and the plugin you wish
14256 to use for the component.
14258 See @url{http://prosody.im/doc/components}.
14259 Defaults to @samp{()}.
14261 Available @code{int-component-configuration} fields are:
14263 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:
14264 @deftypevr {@code{int-component-configuration} parameter} string hostname
14265 Hostname of the component.
14268 @deftypevr {@code{int-component-configuration} parameter} string plugin
14269 Plugin you wish to use for the component.
14272 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
14273 Multi-user chat (MUC) is Prosody's module for allowing you to create
14274 hosted chatrooms/conferences for XMPP users.
14276 General information on setting up and using multi-user chatrooms can be found
14277 in the "Chatrooms" documentation (@url{http://prosody.im/doc/chatrooms}),
14278 which you should read if you are new to XMPP chatrooms.
14280 See also @url{http://prosody.im/doc/modules/mod_muc}.
14282 Available @code{mod-muc-configuration} fields are:
14284 @deftypevr {@code{mod-muc-configuration} parameter} string name
14285 The name to return in service discovery responses.
14286 Defaults to @samp{"Prosody Chatrooms"}.
14289 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
14290 If @samp{#t}, this will only allow admins to create new chatrooms.
14291 Otherwise anyone can create a room. The value @samp{"local"} restricts room
14292 creation to users on the service's parent domain. E.g. @samp{user@@example.com}
14293 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
14294 restricts to service administrators only.
14295 Defaults to @samp{#f}.
14298 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
14299 Maximum number of history messages that will be sent to the member that has
14300 just joined the room.
14301 Defaults to @samp{20}.
14308 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
14309 External components use XEP-0114, which most standalone components
14310 support. To add an external component, you simply fill the hostname field. See
14311 @url{http://prosody.im/doc/components}.
14312 Defaults to @samp{()}.
14314 Available @code{ext-component-configuration} fields are:
14316 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:
14317 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
14318 Password which the component will use to log in.
14321 @deftypevr {@code{ext-component-configuration} parameter} string hostname
14322 Hostname of the component.
14327 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
14328 Port(s) Prosody listens on for component connections.
14329 Defaults to @samp{(5347)}.
14332 @deftypevr {@code{prosody-configuration} parameter} string component-interface
14333 Interface Prosody listens on for component connections.
14334 Defaults to @samp{"127.0.0.1"}.
14337 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
14338 Raw content that will be added to the configuration file.
14341 It could be that you just want to get a @code{prosody.cfg.lua}
14342 up and running. In that case, you can pass an
14343 @code{opaque-prosody-configuration} record as the value of
14344 @code{prosody-service-type}. As its name indicates, an opaque configuration
14345 does not have easy reflective capabilities.
14346 Available @code{opaque-prosody-configuration} fields are:
14348 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
14349 The prosody package.
14352 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
14353 The contents of the @code{prosody.cfg.lua} to use.
14356 For example, if your @code{prosody.cfg.lua} is just the empty
14357 string, you could instantiate a prosody service like this:
14360 (service prosody-service-type
14361 (opaque-prosody-configuration
14362 (prosody.cfg.lua "")))
14366 @node Telephony Services
14367 @subsubsection Telephony Services
14369 @cindex Murmur (VoIP server)
14370 @cindex VoIP server
14371 This section describes how to set up and run a Murmur server. Murmur is
14372 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
14375 @deftp {Data Type} murmur-configuration
14376 The service type for the Murmur server. An example configuration can
14380 (service murmur-service-type
14381 (murmur-configuration
14383 "Welcome to this Mumble server running on GuixSD!")
14384 (cert-required? #t) ;disallow text password logins
14385 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
14386 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
14389 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
14390 password with the command that is printed during the activation phase.
14392 It is recommended to register a normal Mumble user account
14393 and grant it admin or moderator rights.
14394 You can use the @code{mumble} client to
14395 login as new normal user, register yourself, and log out.
14396 For the next step login with the name @code{SuperUser} use
14397 the @code{SuperUser} password that you set previously,
14398 and grant your newly registered mumble user administrator or moderator
14399 rights and create some channels.
14401 Available @code{murmur-configuration} fields are:
14404 @item @code{package} (default: @code{mumble})
14405 Package that contains @code{bin/murmurd}.
14407 @item @code{user} (default: @code{"murmur"})
14408 User who will run the Murmur server.
14410 @item @code{group} (default: @code{"murmur"})
14411 Group of the user who will run the murmur server.
14413 @item @code{port} (default: @code{64738})
14414 Port on which the server will listen.
14416 @item @code{welcome-text} (default: @code{""})
14417 Welcome text sent to clients when they connect.
14419 @item @code{server-password} (default: @code{""})
14420 Password the clients have to enter in order to connect.
14422 @item @code{max-users} (default: @code{100})
14423 Maximum of users that can be connected to the server at once.
14425 @item @code{max-user-bandwidth} (default: @code{#f})
14426 Maximum voice traffic a user can send per second.
14428 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
14429 File name of the sqlite database.
14430 The service's user will become the owner of the directory.
14432 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
14433 File name of the log file.
14434 The service's user will become the owner of the directory.
14436 @item @code{autoban-attempts} (default: @code{10})
14437 Maximum number of logins a user can make in @code{autoban-timeframe}
14438 without getting auto banned for @code{autoban-time}.
14440 @item @code{autoban-timeframe} (default: @code{120})
14441 Timeframe for autoban in seconds.
14443 @item @code{autoban-time} (default: @code{300})
14444 Amount of time in seconds for which a client gets banned
14445 when violating the autoban limits.
14447 @item @code{opus-threshold} (default: @code{100})
14448 Percentage of clients that need to support opus
14449 before switching over to opus audio codec.
14451 @item @code{channel-nesting-limit} (default: @code{10})
14452 How deep channels can be nested at maximum.
14454 @item @code{channelname-regex} (default: @code{#f})
14455 A string in from of a Qt regular expression that channel names must conform to.
14457 @item @code{username-regex} (default: @code{#f})
14458 A string in from of a Qt regular expression that user names must conform to.
14460 @item @code{text-message-length} (default: @code{5000})
14461 Maximum size in bytes that a user can send in one text chat message.
14463 @item @code{image-message-length} (default: @code{(* 128 1024)})
14464 Maximum size in bytes that a user can send in one image message.
14466 @item @code{cert-required?} (default: @code{#f})
14467 If it is set to @code{#t} clients that use weak password authentification
14468 will not be accepted. Users must have completed the certificate wizard to join.
14470 @item @code{remember-channel?} (defualt @code{#f})
14471 Should murmur remember the last channel each user was in when they disconnected
14472 and put them into the remembered channel when they rejoin.
14474 @item @code{allow-html?} (default: @code{#f})
14475 Should html be allowed in text messages, user comments, and channel descriptions.
14477 @item @code{allow-ping?} (default: @code{#f})
14478 Setting to true exposes the current user count, the maximum user count, and
14479 the server's maximum bandwidth per client to unauthenticated users. In the
14480 Mumble client, this information is shown in the Connect dialog.
14482 Disabling this setting will prevent public listing of the server.
14484 @item @code{bonjour?} (default: @code{#f})
14485 Should the server advertise itself in the local network through the bonjour protocol.
14487 @item @code{send-version?} (default: @code{#f})
14488 Should the murmur server version be exposed in ping requests.
14490 @item @code{log-days} (default: @code{31})
14491 Murmur also stores logs in the database, which are accessible via RPC.
14492 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
14493 or -1 to disable logging to the database.
14495 @item @code{obfuscate-ips?} (default @code{#t})
14496 Should logged ips be obfuscated to protect the privacy of users.
14498 @item @code{ssl-cert} (default: @code{#f})
14499 File name of the SSL/TLS certificate used for encrypted connections.
14502 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
14504 @item @code{ssl-key} (default: @code{#f})
14505 Filepath to the ssl private key used for encrypted connections.
14507 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
14510 @item @code{ssl-dh-params} (default: @code{#f})
14511 File name of a PEM-encoded file with Diffie-Hellman parameters
14512 for the SSL/TLS encryption. Alternatively you set it to
14513 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
14514 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
14516 @item @code{ssl-ciphers} (default: @code{#f})
14517 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
14520 This option is specified using
14521 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
14522 OpenSSL cipher list notation}.
14524 It is recommended that you try your cipher string using 'openssl ciphers <string>'
14525 before setting it here, to get a feel for which cipher suites you will get.
14526 After setting this option, it is recommend that you inspect your Murmur log
14527 to ensure that Murmur is using the cipher suites that you expected it to.
14529 Note: Changing this option may impact the backwards compatibility of your
14530 Murmur server, and can remove the ability for older Mumble clients to be able
14533 @item @code{public-registration} (default: @code{#f})
14534 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
14536 You can optionally register your server in the public server list that the
14537 @code{mumble} client shows on startup.
14538 You cannot register your server if you have set a @code{server-password},
14539 or set @code{allow-ping} to @code{#f}.
14541 It might take a few hours until it shows up in the public list.
14543 @item @code{file} (default: @code{#f})
14544 Optional alternative override for this configuration.
14548 @deftp {Data Type} murmur-public-registration-configuration
14549 Configuration for public registration of a murmur service.
14553 This is a display name for your server. Not to be confused with the hostname.
14555 @item @code{password}
14556 A password to identify your registration.
14557 Subsequent updates will need the same password. Don't lose your password.
14560 This should be a @code{http://} or @code{https://} link to your web
14563 @item @code{hostname} (default: @code{#f})
14564 By default your server will be listed by its IP address.
14565 If it is set your server will be linked by this host name instead.
14571 @node Monitoring Services
14572 @subsubsection Monitoring Services
14574 @subsubheading Tailon Service
14576 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
14577 viewing and searching log files.
14579 The following example will configure the service with default values.
14580 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
14583 (service tailon-service-type)
14586 The following example customises more of the Tailon configuration,
14587 adding @command{sed} to the list of allowed commands.
14590 (service tailon-service-type
14591 (tailon-configuration
14593 (tailon-configuration-file
14594 (allowed-commands '("tail" "grep" "awk" "sed"))))))
14598 @deftp {Data Type} tailon-configuration
14599 Data type representing the configuration of Tailon.
14600 This type has the following parameters:
14603 @item @code{config-file} (default: @code{(tailon-configuration-file)})
14604 The configuration file to use for Tailon. This can be set to a
14605 @dfn{tailon-configuration-file} record value, or any gexp
14606 (@pxref{G-Expressions}).
14608 For example, to instead use a local file, the @code{local-file} function
14612 (service tailon-service-type
14613 (tailon-configuration
14614 (config-file (local-file "./my-tailon.conf"))))
14617 @item @code{package} (default: @code{tailon})
14618 The tailon package to use.
14623 @deftp {Data Type} tailon-configuration-file
14624 Data type representing the configuration options for Tailon.
14625 This type has the following parameters:
14628 @item @code{files} (default: @code{(list "/var/log")})
14629 List of files to display. The list can include strings for a single file
14630 or directory, or a list, where the first item is the name of a
14631 subsection, and the remaining items are the files or directories in that
14634 @item @code{bind} (default: @code{"localhost:8080"})
14635 Address and port to which Tailon should bind on.
14637 @item @code{relative-root} (default: @code{#f})
14638 URL path to use for Tailon, set to @code{#f} to not use a path.
14640 @item @code{allow-transfers?} (default: @code{#t})
14641 Allow downloading the log files in the web interface.
14643 @item @code{follow-names?} (default: @code{#t})
14644 Allow tailing of not-yet existent files.
14646 @item @code{tail-lines} (default: @code{200})
14647 Number of lines to read initially from each file.
14649 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
14650 Commands to allow running. By default, @code{sed} is disabled.
14652 @item @code{debug?} (default: @code{#f})
14653 Set @code{debug?} to @code{#t} to show debug messages.
14655 @item @code{wrap-lines} (default: @code{#t})
14656 Initial line wrapping state in the web interface. Set to @code{#t} to
14657 initially wrap lines (the default), or to @code{#f} to initially not
14660 @item @code{http-auth} (default: @code{#f})
14661 HTTP authentication type to use. Set to @code{#f} to disable
14662 authentication (the default). Supported values are @code{"digest"} or
14665 @item @code{users} (default: @code{#f})
14666 If HTTP authentication is enabled (see @code{http-auth}), access will be
14667 restricted to the credentials provided here. To configure users, use a
14668 list of pairs, where the first element of the pair is the username, and
14669 the 2nd element of the pair is the password.
14672 (tailon-configuration-file
14673 (http-auth "basic")
14674 (users '(("user1" . "password1")
14675 ("user2" . "password2"))))
14682 @node Kerberos Services
14683 @subsubsection Kerberos Services
14686 The @code{(gnu services kerberos)} module provides services relating to
14687 the authentication protocol @dfn{Kerberos}.
14689 @subsubheading Krb5 Service
14691 Programs using a Kerberos client library normally
14692 expect a configuration file in @file{/etc/krb5.conf}.
14693 This service generates such a file from a definition provided in the
14694 operating system declaration.
14695 It does not cause any daemon to be started.
14697 No ``keytab'' files are provided by this service---you must explicitly create them.
14698 This service is known to work with the MIT client library, @code{mit-krb5}.
14699 Other implementations have not been tested.
14701 @defvr {Scheme Variable} krb5-service-type
14702 A service type for Kerberos 5 clients.
14706 Here is an example of its use:
14708 (service krb5-service-type
14709 (krb5-configuration
14710 (default-realm "EXAMPLE.COM")
14711 (allow-weak-crypto? #t)
14714 (name "EXAMPLE.COM")
14715 (admin-server "groucho.example.com")
14716 (kdc "karl.example.com"))
14719 (admin-server "kerb-admin.argrx.edu")
14720 (kdc "keys.argrx.edu"))))))
14724 This example provides a Kerberos@tie{}5 client configuration which:
14726 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
14727 of which have distinct administration servers and key distribution centers;
14728 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
14729 specified by clients;
14730 @item Accepts services which only support encryption types known to be weak.
14733 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
14734 Only the most commonly used ones are described here.
14735 For a full list, and more detailed explanation of each, see the MIT
14736 @uref{http://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
14740 @deftp {Data Type} krb5-realm
14741 @cindex realm, kerberos
14744 This field is a string identifying the name of the realm.
14745 A common convention is to use the fully qualified DNS name of your organization,
14746 converted to upper case.
14748 @item @code{admin-server}
14749 This field is a string identifying the host where the administration server is
14753 This field is a string identifying the key distribution center
14758 @deftp {Data Type} krb5-configuration
14761 @item @code{allow-weak-crypto?} (default: @code{#f})
14762 If this flag is @code{#t} then services which only offer encryption algorithms
14763 known to be weak will be accepted.
14765 @item @code{default-realm} (default: @code{#f})
14766 This field should be a string identifying the default Kerberos
14767 realm for the client.
14768 You should set this field to the name of your Kerberos realm.
14769 If this value is @code{#f}
14770 then a realm must be specified with every Kerberos principal when invoking programs
14771 such as @command{kinit}.
14773 @item @code{realms}
14774 This should be a non-empty list of @code{krb5-realm} objects, which clients may
14776 Normally, one of them will have a @code{name} field matching the @code{default-realm}
14782 @subsubheading PAM krb5 Service
14785 The @code{pam-krb5} service allows for login authentication and password
14786 management via Kerberos.
14787 You will need this service if you want PAM enabled applications to authenticate
14788 users using Kerberos.
14790 @defvr {Scheme Variable} pam-krb5-service-type
14791 A service type for the Kerberos 5 PAM module.
14794 @deftp {Data Type} pam-krb5-configuration
14795 Data type representing the configuration of the Kerberos 5 PAM module
14796 This type has the following parameters:
14798 @item @code{pam-krb5} (default: @code{pam-krb5})
14799 The pam-krb5 package to use.
14801 @item @code{minimum-uid} (default: @code{1000})
14802 The smallest user ID for which Kerberos authentications should be attempted.
14803 Local accounts with lower values will silently fail to authenticate.
14809 @subsubsection Web Services
14814 The @code{(gnu services web)} module provides the nginx web server and
14815 also a fastcgi wrapper daemon.
14817 @deffn {Scheme Variable} nginx-service-type
14818 Service type for the @uref{https://nginx.org/,NGinx} web server. The
14819 value for this service type is a @code{<nginx-configuration>} record.
14821 A simple example configuration is given below.
14824 (service nginx-service-type
14825 (nginx-configuration
14827 (list (nginx-server-configuration
14828 (server-name '("www.example.com"))
14829 (root "/srv/http/www.example.com")
14831 (ssl-certificate #f)
14832 (ssl-certificate-key #f))))))
14835 In addition to adding server blocks to the service configuration
14836 directly, this service can be extended by other services to add server
14837 blocks, as in this example:
14840 (simple-service 'my-extra-server nginx-service-type
14841 (list (nginx-server-configuration
14843 (ssl-certificate #f)
14844 (ssl-certificate-key #f)
14845 (root "/srv/http/extra-website")
14846 (try-files (list "$uri" "$uri/index.html")))))
14850 At startup, @command{nginx} has not yet read its configuration file, so
14851 it uses a default file to log error messages. If it fails to load its
14852 configuration file, that is where error messages are logged. After the
14853 configuration file is loaded, the default error log file changes as per
14854 configuration. In our case, startup error messages can be found in
14855 @file{/var/run/nginx/logs/error.log}, and after configuration in
14856 @file{/var/log/nginx/error.log}. The second location can be changed
14857 with the @var{log-directory} configuration option.
14859 @deffn {Data Type} nginx-configuration
14860 This data type represents the configuration for NGinx. Some
14861 configuration can be done through this and the other provided record
14862 types, or alternatively, a config file can be provided.
14865 @item @code{nginx} (default: @code{nginx})
14866 The nginx package to use.
14868 @item @code{log-directory} (default: @code{"/var/log/nginx"})
14869 The directory to which NGinx will write log files.
14871 @item @code{run-directory} (default: @code{"/var/run/nginx"})
14872 The directory in which NGinx will create a pid file, and write temporary
14875 @item @code{server-blocks} (default: @code{'()})
14876 A list of @dfn{server blocks} to create in the generated configuration
14877 file, the elements should be of type
14878 @code{<nginx-server-configuration>}.
14880 The following example would setup NGinx to serve @code{www.example.com}
14881 from the @code{/srv/http/www.example.com} directory, without using
14884 (service nginx-service-type
14885 (nginx-configuration
14887 (list (nginx-server-configuration
14888 (server-name '("www.example.com"))
14889 (root "/srv/http/www.example.com")
14891 (ssl-certificate #f)
14892 (ssl-certificate-key #f))))))
14895 @item @code{upstream-blocks} (default: @code{'()})
14896 A list of @dfn{upstream blocks} to create in the generated configuration
14897 file, the elements should be of type
14898 @code{<nginx-upstream-configuration>}.
14900 Configuring upstreams through the @code{upstream-blocks} can be useful
14901 when combined with @code{locations} in the
14902 @code{<nginx-server-configuration>} records. The following example
14903 creates a server configuration with one location configuration, that
14904 will proxy requests to a upstream configuration, which will handle
14905 requests with two servers.
14910 (nginx-configuration
14912 (list (nginx-server-configuration
14913 (server-name '("www.example.com"))
14914 (root "/srv/http/www.example.com")
14916 (ssl-certificate #f)
14917 (ssl-certificate-key #f)
14920 (nginx-location-configuration
14922 (body '("proxy_pass http://server-proxy;"))))))))
14924 (list (nginx-upstream-configuration
14925 (name "server-proxy")
14926 (servers (list "server1.example.com"
14927 "server2.example.com")))))))
14930 @item @code{file} (default: @code{#f})
14931 If a configuration @var{file} is provided, this will be used, rather than
14932 generating a configuration file from the provided @code{log-directory},
14933 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
14934 proper operation, these arguments should match what is in @var{file} to ensure
14935 that the directories are created when the service is activated.
14937 This can be useful if you have an existing configuration file, or it's
14938 not possible to do what is required through the other parts of the
14939 nginx-configuration record.
14944 @deftp {Data Type} nginx-server-configuration
14945 Data type representing the configuration of an nginx server block.
14946 This type has the following parameters:
14949 @item @code{http-port} (default: @code{80})
14950 Nginx will listen for HTTP connection on this port. Set it at @code{#f} if
14951 nginx should not listen for HTTP (non secure) connection for this
14952 @dfn{server block}.
14954 @item @code{https-port} (default: @code{443})
14955 Nginx will listen for HTTPS connection on this port. Set it at @code{#f} if
14956 nginx should not listen for HTTPS (secure) connection for this @dfn{server block}.
14958 Note that nginx can listen for HTTP and HTTPS connections in the same
14959 @dfn{server block}.
14961 @item @code{server-name} (default: @code{(list 'default)})
14962 A list of server names this server represents. @code{'default} represents the
14963 default server for connections matching no other server.
14965 @item @code{root} (default: @code{"/srv/http"})
14966 Root of the website nginx will serve.
14968 @item @code{locations} (default: @code{'()})
14969 A list of @dfn{nginx-location-configuration} or
14970 @dfn{nginx-named-location-configuration} records to use within this
14973 @item @code{index} (default: @code{(list "index.html")})
14974 Index files to look for when clients ask for a directory. If it cannot be found,
14975 Nginx will send the list of files in the directory.
14977 @item @code{try-files} (default: @code{'()})
14978 A list of files whose existence is checked in the specified order.
14979 @code{nginx} will use the first file it finds to process the request.
14981 @item @code{ssl-certificate} (default: @code{"/etc/nginx/cert.pem"})
14982 Where to find the certificate for secure connections. Set it to @code{#f} if
14983 you don't have a certificate or you don't want to use HTTPS.
14985 @item @code{ssl-certificate-key} (default: @code{"/etc/nginx/key.pem"})
14986 Where to find the private key for secure connections. Set it to @code{#f} if
14987 you don't have a key or you don't want to use HTTPS.
14989 @item @code{server-tokens?} (default: @code{#f})
14990 Whether the server should add its configuration to response.
14995 @deftp {Data Type} nginx-upstream-configuration
14996 Data type representing the configuration of an nginx @code{upstream}
14997 block. This type has the following parameters:
15001 Name for this group of servers.
15003 @item @code{servers}
15004 Specify the addresses of the servers in the group. The address can be
15005 specified as a IP address (e.g. @samp{127.0.0.1}), domain name
15006 (e.g. @samp{backend1.example.com}) or a path to a UNIX socket using the
15007 prefix @samp{unix:}. For addresses using an IP address or domain name,
15008 the default port is 80, and a different port can be specified
15014 @deftp {Data Type} nginx-location-configuration
15015 Data type representing the configuration of an nginx @code{location}
15016 block. This type has the following parameters:
15020 URI which this location block matches.
15022 @anchor{nginx-location-configuration body}
15024 Body of the location block, specified as a string. This can contain many
15025 configuration directives. For example, to pass requests to a upstream
15026 server group defined using an @code{nginx-upstream-configuration} block,
15027 the following directive would be specified in the body @samp{proxy_pass
15028 http://upstream-name;}.
15033 @deftp {Data Type} nginx-named-location-configuration
15034 Data type representing the configuration of an nginx named location
15035 block. Named location blocks are used for request redirection, and not
15036 used for regular request processing. This type has the following
15041 Name to identify this location block.
15044 @xref{nginx-location-configuration body}, as the body for named location
15045 blocks can be used in a similar way to the
15046 @code{nginx-location-configuration body}. One restriction is that the
15047 body of a named location block cannot contain location blocks.
15054 FastCGI is an interface between the front-end and the back-end of a web
15055 service. It is a somewhat legacy facility; new web services should
15056 generally just talk HTTP between the front-end and the back-end.
15057 However there are a number of back-end services such as PHP or the
15058 optimized HTTP Git repository access that use FastCGI, so we have
15059 support for it in Guix.
15061 To use FastCGI, you configure the front-end web server (e.g., nginx) to
15062 dispatch some subset of its requests to the fastcgi backend, which
15063 listens on a local TCP or UNIX socket. There is an intermediary
15064 @code{fcgiwrap} program that sits between the actual backend process and
15065 the web server. The front-end indicates which backend program to run,
15066 passing that information to the @code{fcgiwrap} process.
15068 @defvr {Scheme Variable} fcgiwrap-service-type
15069 A service type for the @code{fcgiwrap} FastCGI proxy.
15072 @deftp {Data Type} fcgiwrap-configuration
15073 Data type representing the configuration of the @code{fcgiwrap} serice.
15074 This type has the following parameters:
15076 @item @code{package} (default: @code{fcgiwrap})
15077 The fcgiwrap package to use.
15079 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
15080 The socket on which the @code{fcgiwrap} process should listen, as a
15081 string. Valid @var{socket} values include
15082 @code{unix:@var{/path/to/unix/socket}},
15083 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
15084 @code{tcp6:[@var{ipv6_addr}]:port}.
15086 @item @code{user} (default: @code{fcgiwrap})
15087 @itemx @code{group} (default: @code{fcgiwrap})
15088 The user and group names, as strings, under which to run the
15089 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
15090 the user asks for the specific user or group names @code{fcgiwrap} that
15091 the corresponding user and/or group is present on the system.
15093 It is possible to configure a FastCGI-backed web service to pass HTTP
15094 authentication information from the front-end to the back-end, and to
15095 allow @code{fcgiwrap} to run the back-end process as a corresponding
15096 local user. To enable this capability on the back-end., run
15097 @code{fcgiwrap} as the @code{root} user and group. Note that this
15098 capability also has to be configured on the front-end as well.
15102 @node Certificate Services
15103 @subsubsection Certificate Services
15106 @cindex HTTP, HTTPS
15107 @cindex Let's Encrypt
15108 @cindex TLS certificates
15109 The @code{(gnu services certbot)} module provides a service to
15110 automatically obtain a valid TLS certificate from the Let's Encrypt
15111 certificate authority. These certificates can then be used to serve
15112 content securely over HTTPS or other TLS-based protocols, with the
15113 knowledge that the client will be able to verify the server's
15116 @url{https://letsencrypt.org/, Let's Encrypt} provides the
15117 @code{certbot} tool to automate the certification process. This tool
15118 first securely generates a key on the server. It then makes a request
15119 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
15120 checks that the request originates from the host in question by using a
15121 challenge-response protocol, requiring the server to provide its
15122 response over HTTP. If that protocol completes successfully, the CA
15123 signs the key, resulting in a certificate. That certificate is valid
15124 for a limited period of time, and therefore to continue to provide TLS
15125 services, the server needs to periodically ask the CA to renew its
15128 The certbot service automates this process: the initial key
15129 generation, the initial certification request to the Let's Encrypt
15130 service, the web server challenge/response integration, writing the
15131 certificate to disk, and the automated periodic renewals.
15133 @defvr {Scheme Variable} certbot-service-type
15134 A service type for the @code{certbot} Let's Encrypt client.
15137 @deftp {Data Type} certbot-configuration
15138 Data type representing the configuration of the @code{certbot} serice.
15139 This type has the following parameters:
15142 @item @code{package} (default: @code{certbot})
15143 The certbot package to use.
15145 @item @code{webroot} (default: @code{/var/www})
15146 The directory from which to serve the Let's Encrypt challenge/response
15149 @item @code{hosts} (default: @code{()})
15150 A list of hosts for which to generate certificates and request
15153 @item @code{default-location} (default: @i{see below})
15154 The default @code{nginx-location-configuration}. Because @code{certbot}
15155 needs to be able to serve challenges and responses, it needs to be able
15156 to run a web server. It does so by extending the @code{nginx} web
15157 service with an @code{nginx-server-configuration} listening on the
15158 @var{hosts} on port 80, and which has a
15159 @code{nginx-location-configuration} for the @code{/.well-known/} URI
15160 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
15161 these nginx configuration data types.
15163 Requests to other URL paths will be matched by the
15164 @code{default-location}, which if present is added to all
15165 @code{nginx-server-configuration}s.
15167 By default, the @code{default-location} will issue a redirect from
15168 @code{http://@var{host}/...} to @code{https://@var{host}/...}, leaving
15169 you to define what to serve on your site via @code{https}.
15171 Pass @code{#f} to not issue a default location.
15175 The public key and its signatures will be written to
15176 @code{/etc/letsencrypt/live/@var{host}/fullchain.pem}, for each
15177 @var{host} in the configuration. The private key is written to
15178 @code{/etc/letsencrypt/live/@var{host}/privkey.pem}.
15182 @subsubsection DNS Services
15183 @cindex DNS (domain name system)
15184 @cindex domain name system (DNS)
15186 The @code{(gnu services dns)} module provides services related to the
15187 @dfn{domain name system} (DNS). It provides a server service for hosting
15188 an @emph{authoritative} DNS server for multiple zones, slave or master.
15189 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}.
15191 An example configuration of an authoritative server for two zones, one master
15195 (define-zone-entries example.org.zone
15196 ;; Name TTL Class Type Data
15197 ("@@" "" "IN" "A" "127.0.0.1")
15198 ("@@" "" "IN" "NS" "ns")
15199 ("ns" "" "IN" "A" "127.0.0.1"))
15201 (define master-zone
15202 (knot-zone-configuration
15203 (domain "example.org")
15205 (origin "example.org")
15206 (entries example.org.zone)))))
15209 (knot-zone-configuration
15210 (domain "plop.org")
15211 (dnssec-policy "default")
15212 (master (list "plop-master"))))
15214 (define plop-master
15215 (knot-remote-configuration
15217 (address (list "208.76.58.171"))))
15221 (services (cons* (service knot-service-type
15222 (knot-confifguration
15223 (remotes (list plop-master))
15224 (zones (list master-zone slave-zone))))
15229 @deffn {Scheme Variable} knot-service-type
15230 This is the type for the Knot DNS server.
15232 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
15233 zones, that is to say domain names you would buy from a registrar. This server
15234 is not a resolver, meaning that it can only resolve names for which it is
15235 authoritative. This server can be configured to serve zones as a master server
15236 or a slave server as a per-zone basis. Slave zones will get their data from
15237 masters, and will serve it as an authoritative server. From the point of view
15238 of a resolver, there is no difference between master and slave.
15240 The following data types are used to configure the Knot DNS server:
15243 @deftp {Data Type} knot-key-configuration
15244 Data type representing a key.
15245 This type has the following parameters:
15248 @item @code{id} (default: @code{""})
15249 An identifier for other configuration fields to refer to this key. IDs must
15250 be unique and must not be empty.
15252 @item @code{algorithm} (default: @code{#f})
15253 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
15254 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
15255 and @code{'hmac-sha512}.
15257 @item @code{secret} (default: @code{""})
15258 The secret key itself.
15263 @deftp {Data Type} knot-acl-configuration
15264 Data type representing an Access Control List (ACL) configuration.
15265 This type has the following parameters:
15268 @item @code{id} (default: @code{""})
15269 An identifier for ether configuration fields to refer to this key. IDs must be
15270 unique and must not be empty.
15272 @item @code{address} (default: @code{'()})
15273 An ordered list of IP addresses, network subnets, or network ranges represented
15274 with strings. The query must match one of them. Empty value means that
15275 address match is not required.
15277 @item @code{key} (default: @code{'()})
15278 An ordered list of references to keys represented with strings. The string
15279 must match a key ID defined in a @code{knot-key-configuration}. No key means
15280 that a key is not require to match that ACL.
15282 @item @code{action} (default: @code{'()})
15283 An ordered list of actions that are permitted or forbidden by this ACL. Possible
15284 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
15285 and @code{'update}.
15287 @item @code{deny?} (default: @code{#f})
15288 When true, the ACL defines restrictions. Listed actions are forbidden. When
15289 false, listed actions are allowed.
15294 @deftp {Data Type} zone-entry
15295 Data type represnting a record entry in a zone file.
15296 This type has the following parameters:
15299 @item @code{name} (default: @code{"@@"})
15300 The name of the record. @code{"@@"} refers to the origin of the zone. Names
15301 are relative to the origin of the zone. For example, in the @code{example.org}
15302 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
15303 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
15304 refers to @code{ns.example.org}.
15306 @item @code{ttl} (default: @code{""})
15307 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
15309 @item @code{class} (default: @code{"IN"})
15310 The class of the record. Knot currently supports only @code{"IN"} and
15311 partially @code{"CH"}.
15313 @item @code{type} (default: @code{"A"})
15314 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
15315 address), NS (Name Server) and MX (Mail eXchange). Many other types are
15318 @item @code{data} (default: @code{""})
15319 The data contained in the record. For instance an IP address associated with
15320 an A record, or a domain name associated with an NS record. Remember that
15321 domain names are relative to the origin unless they end with a dot.
15326 @deftp {Data Type} zone-file
15327 Data type representing the content of a zone file.
15328 This type has the following parameters:
15331 @item @code{entries} (default: @code{'()})
15332 The list of entries. The SOA record is taken care of, so you don't need to
15333 put it in the list of entries. This list should probably contain an entry
15334 for your primary authoritative DNS server. Other than using a list of entries
15335 directly, you can use @code{define-zone-entries} to define a object containing
15336 the list of entries more easily, that you can later pass to the @code{entries}
15337 field of the @code{zone-file}.
15339 @item @code{origin} (default: @code{""})
15340 The name of your zone. This parameter cannot be empty.
15342 @item @code{ns} (default: @code{"ns"})
15343 The domain of your primary authoritative DNS server. The name is relative to
15344 the origin, unless it ends with a dot. It is mandatory that this primary
15345 DNS server corresponds to an NS record in the zone and that it is associated
15346 to an IP address in the list of entries.
15348 @item @code{mail} (default: @code{"hostmaster"})
15349 An email address people can contact you at, as the owner of the zone. This
15350 is translated as @code{<mail>@@<origin>}.
15352 @item @code{serial} (default: @code{1})
15353 The serial number of the zone. As this is used to keep track of changes by
15354 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
15355 Always increment it when you make a change in your zone.
15357 @item @code{refresh} (default: @code{(* 2 24 3600)})
15358 The frequency at which slaves will do a zone transfer. This value is a number
15359 of seconds. It can be computed by multiplications or with
15360 @code{(string->duration)}.
15362 @item @code{retry} (default: @code{(* 15 60)})
15363 The period after which a slave will retry to contact its master when it fails
15364 to do so a first time.
15366 @item @code{expiry} (default: @code{(* 14 24 3600)})
15367 Default TTL of records. Existing records are considered correct for at most
15368 this amount of time. After this period, resolvers will invalidate their cache
15369 and check again that it still exists.
15371 @item @code{nx} (default: @code{3600})
15372 Default TTL of inexistant records. This delay is usually short because you want
15373 your new domains to reach everyone quickly.
15378 @deftp {Data Type} knot-remote-configuration
15379 Data type representing a remote configuration.
15380 This type has the following parameters:
15383 @item @code{id} (default: @code{""})
15384 An identifier for other configuration fields to refer to this remote. IDs must
15385 be unique and must not be empty.
15387 @item @code{address} (default: @code{'()})
15388 An ordered list of destination IP addresses. Addresses are tried in sequence.
15389 An optional port can be given with the @@ separator. For instance:
15390 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
15392 @item @code{via} (default: @code{'()})
15393 An ordered list of source IP addresses. An empty list will have Knot choose
15394 an appropriate source IP. An optional port can be given with the @@ separator.
15395 The default is to choose at random.
15397 @item @code{key} (default: @code{#f})
15398 A reference to a key, that is a string containing the identifier of a key
15399 defined in a @code{knot-key-configuration} field.
15404 @deftp {Data Type} knot-keystore-configuration
15405 Data type representing a keystore to hold dnssec keys.
15406 This type has the following parameters:
15409 @item @code{id} (default: @code{""})
15410 The id of the keystore. It must not be empty.
15412 @item @code{backend} (default: @code{'pem})
15413 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
15415 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
15416 The configuration string of the backend. An example for the PKCS#11 is:
15417 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
15418 For the pem backend, the string reprensents a path in the filesystem.
15423 @deftp {Data Type} knot-policy-configuration
15424 Data type representing a dnssec policy. Knot DNS is able to automatically
15425 sign your zones. It can either generate and manage your keys automatically or
15426 use keys that you generate.
15428 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
15429 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
15430 zone. In order to be trusted, the KSK needs to be present in the parent zone
15431 (usually a top-level domain). If your registrar supports dnssec, you will
15432 have to send them your KSK's hash so they can add a DS record in their zone.
15433 This is not automated and need to be done each time you change your KSK.
15435 The policy also defines the lifetime of keys. Usually, ZSK can be changed
15436 easily and use weaker cryptographic functions (they use lower parameters) in
15437 order to sign records quickly, so they are changed often. The KSK however
15438 requires manual interaction with the registrar, so they are changed less often
15439 and use stronger parameters because they sign only one record.
15441 This type has the following parameters:
15444 @item @code{id} (default: @code{""})
15445 The id of the policy. It must not be empty.
15447 @item @code{keystore} (default: @code{"default"})
15448 A reference to a keystore, that is a string containing the identifier of a
15449 keystore defined in a @code{knot-keystore-configuration} field. The
15450 @code{"default"} identifier means the default keystore (a kasp database that
15451 was setup by this service).
15453 @item @code{manual?} (default: @code{#f})
15454 Whether the key management is manual or automatic.
15456 @item @code{single-type-signing?} (default: @code{#f})
15457 When @code{#t}, use the Single-Type Signing Scheme.
15459 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
15460 An algorithm of signing keys and issued signatures.
15462 @item @code{ksk-size} (default: @code{256})
15463 The length of the KSK. Note that this value is correct for the default
15464 algorithm, but would be unsecure for other algorithms.
15466 @item @code{zsk-size} (default: @code{256})
15467 The length of the ZSK. Note that this value is correct for the default
15468 algorithm, but would be unsecure for other algorithms.
15470 @item @code{dnskey-ttl} (default: @code{'default})
15471 The TTL value for DNSKEY records added into zone apex. The special
15472 @code{'default} value means same as the zone SOA TTL.
15474 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
15475 The period between ZSK publication and the next rollover initiation.
15477 @item @code{propagation-delay} (default: @code{(* 24 3600)})
15478 An extra delay added for each key rollover step. This value should be high
15479 enough to cover propagation of data from the master server to all slaves.
15481 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
15482 A validity period of newly issued signatures.
15484 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
15485 A period how long before a signature expiration the signature will be refreshed.
15487 @item @code{nsec3?} (default: @code{#f})
15488 When @code{#t}, NSEC3 will be used instead of NSEC.
15490 @item @code{nsec3-iterations} (default: @code{5})
15491 The number of additional times the hashing is performed.
15493 @item @code{nsec3-salt-length} (default: @code{8})
15494 The length of a salt field in octets, which is appended to the original owner
15495 name before hashing.
15497 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
15498 The validity period of newly issued salt field.
15503 @deftp {Data Type} knot-zone-configuration
15504 Data type representing a zone served by Knot.
15505 This type has the following parameters:
15508 @item @code{domain} (default: @code{""})
15509 The domain served by this configuration. It must not be empty.
15511 @item @code{file} (default: @code{""})
15512 The file where this zone is saved. This parameter is ignored by master zones.
15513 Empty means default location that depends on the domain name.
15515 @item @code{zone} (default: @code{(zone-file)})
15516 The content of the zone file. This parameter is ignored by slave zones. It
15517 must contain a zone-file record.
15519 @item @code{master} (default: @code{'()})
15520 A list of master remotes. When empty, this zone is a master. When set, this
15521 zone is a slave. This is a list of remotes identifiers.
15523 @item @code{ddns-master} (default: @code{#f})
15524 The main master. When empty, it defaults to the first master in the list of
15527 @item @code{notify} (default: @code{'()})
15528 A list of slave remote identifiers.
15530 @item @code{acl} (default: @code{'()})
15531 A list of acl identifiers.
15533 @item @code{semantic-checks?} (default: @code{#f})
15534 When set, this adds more semantic checks to the zone.
15536 @item @code{disable-any?} (default: @code{#f})
15537 When set, this forbids queries of the ANY type.
15539 @item @code{zonefile-sync} (default: @code{0})
15540 The delay between a modification in memory and on disk. 0 means immediate
15543 @item @code{serial-policy} (default: @code{'increment})
15544 A policy between @code{'increment} and @code{'unixtime}.
15549 @deftp {Data Type} knot-configuration
15550 Data type representing the Knot configuration.
15551 This type has the following parameters:
15554 @item @code{knot} (default: @code{knot})
15557 @item @code{run-directory} (default: @code{"/var/run/knot"})
15558 The run directory. This directory will be used for pid file and sockets.
15560 @item @code{listen-v4} (default: @code{"0.0.0.0"})
15561 An ip address on which to listen.
15563 @item @code{listen-v6} (default: @code{"::"})
15564 An ip address on which to listen.
15566 @item @code{listen-port} (default: @code{53})
15567 A port on which to listen.
15569 @item @code{keys} (default: @code{'()})
15570 The list of knot-key-configuration used by this configuration.
15572 @item @code{acls} (default: @code{'()})
15573 The list of knot-acl-configuration used by this configuration.
15575 @item @code{remotes} (default: @code{'()})
15576 The list of knot-remote-configuration used by this configuration.
15578 @item @code{zones} (default: @code{'()})
15579 The list of knot-zone-configuration used by this configuration.
15586 @subsubsection VPN Services
15587 @cindex VPN (virtual private network)
15588 @cindex virtual private network (VPN)
15590 The @code{(gnu services vpn)} module provides services related to
15591 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
15592 your machine to connect to a VPN, and a @emph{servire} service for your machine
15593 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
15595 @deffn {Scheme Procedure} openvpn-client-service @
15596 [#:config (openvpn-client-configuration)]
15598 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
15601 @deffn {Scheme Procedure} openvpn-server-service @
15602 [#:config (openvpn-server-configuration)]
15604 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
15606 Both can be run simultaneously.
15609 @c %automatically generated documentation
15611 Available @code{openvpn-client-configuration} fields are:
15613 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
15614 The OpenVPN package.
15618 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
15619 The OpenVPN pid file.
15621 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
15625 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
15626 The protocol (UDP or TCP) used to open a channel between clients and
15629 Defaults to @samp{udp}.
15633 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
15634 The device type used to represent the VPN connection.
15636 Defaults to @samp{tun}.
15640 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
15641 The certificate authority to check connections against.
15643 Defaults to @samp{"/etc/openvpn/ca.crt"}.
15647 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
15648 The certificate of the machine the daemon is running on. It should be
15649 signed by the authority given in @code{ca}.
15651 Defaults to @samp{"/etc/openvpn/client.crt"}.
15655 @deftypevr {@code{openvpn-client-configuration} parameter} string key
15656 The key of the machine the daemon is running on. It must be the key whose
15657 certificate is @code{cert}.
15659 Defaults to @samp{"/etc/openvpn/client.key"}.
15663 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
15664 Whether to use the lzo compression algorithm.
15666 Defaults to @samp{#t}.
15670 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
15671 Don't re-read key files across SIGUSR1 or --ping-restart.
15673 Defaults to @samp{#t}.
15677 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
15678 Don't close and reopen TUN/TAP device or run up/down scripts across
15679 SIGUSR1 or --ping-restart restarts.
15681 Defaults to @samp{#t}.
15685 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
15688 Defaults to @samp{3}.
15692 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
15693 Add an additional layer of HMAC authentication on top of the TLS control
15694 channel to protect against DoS attacks.
15696 Defaults to @samp{#f}.
15700 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
15701 Whether to check the server certificate has server usage extension.
15703 Defaults to @samp{#t}.
15707 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
15708 Bind to a specific local port number.
15710 Defaults to @samp{#f}.
15714 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
15715 Retry resolving server address.
15717 Defaults to @samp{#t}.
15721 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
15722 A list of remote servers to connect to.
15724 Defaults to @samp{()}.
15726 Available @code{openvpn-remote-configuration} fields are:
15728 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
15731 Defaults to @samp{"my-server"}.
15735 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
15736 Port number the server listens to.
15738 Defaults to @samp{1194}.
15743 @c %end of automatic openvpn-client documentation
15745 @c %automatically generated documentation
15747 Available @code{openvpn-server-configuration} fields are:
15749 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
15750 The OpenVPN package.
15754 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
15755 The OpenVPN pid file.
15757 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
15761 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
15762 The protocol (UDP or TCP) used to open a channel between clients and
15765 Defaults to @samp{udp}.
15769 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
15770 The device type used to represent the VPN connection.
15772 Defaults to @samp{tun}.
15776 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
15777 The certificate authority to check connections against.
15779 Defaults to @samp{"/etc/openvpn/ca.crt"}.
15783 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
15784 The certificate of the machine the daemon is running on. It should be
15785 signed by the authority given in @code{ca}.
15787 Defaults to @samp{"/etc/openvpn/client.crt"}.
15791 @deftypevr {@code{openvpn-server-configuration} parameter} string key
15792 The key of the machine the daemon is running on. It must be the key whose
15793 certificate is @code{cert}.
15795 Defaults to @samp{"/etc/openvpn/client.key"}.
15799 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
15800 Whether to use the lzo compression algorithm.
15802 Defaults to @samp{#t}.
15806 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
15807 Don't re-read key files across SIGUSR1 or --ping-restart.
15809 Defaults to @samp{#t}.
15813 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
15814 Don't close and reopen TUN/TAP device or run up/down scripts across
15815 SIGUSR1 or --ping-restart restarts.
15817 Defaults to @samp{#t}.
15821 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
15824 Defaults to @samp{3}.
15828 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
15829 Add an additional layer of HMAC authentication on top of the TLS control
15830 channel to protect against DoS attacks.
15832 Defaults to @samp{#f}.
15836 @deftypevr {@code{openvpn-server-configuration} parameter} number port
15837 Specifies the port number on which the server listens.
15839 Defaults to @samp{1194}.
15843 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
15844 An ip and mask specifying the subnet inside the virtual network.
15846 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
15850 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
15851 A CIDR notation specifying the IPv6 subnet inside the virtual network.
15853 Defaults to @samp{#f}.
15857 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
15858 The Diffie-Hellman parameters file.
15860 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
15864 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
15865 The file that records client IPs.
15867 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
15871 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
15872 When true, the server will act as a gateway for its clients.
15874 Defaults to @samp{#f}.
15878 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
15879 When true, clients are allowed to talk to each other inside the VPN.
15881 Defaults to @samp{#f}.
15885 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
15886 Causes ping-like messages to be sent back and forth over the link so
15887 that each side knows when the other side has gone down. @code{keepalive}
15888 requires a pair. The first element is the period of the ping sending,
15889 and the second element is the timeout before considering the other side
15894 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
15895 The maximum number of clients.
15897 Defaults to @samp{100}.
15901 @deftypevr {@code{openvpn-server-configuration} parameter} string status
15902 The status file. This file shows a small report on current connection.
15903 It is truncated and rewritten every minute.
15905 Defaults to @samp{"/var/run/openvpn/status"}.
15909 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
15910 The list of configuration for some clients.
15912 Defaults to @samp{()}.
15914 Available @code{openvpn-ccd-configuration} fields are:
15916 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
15919 Defaults to @samp{"client"}.
15923 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
15926 Defaults to @samp{#f}.
15930 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
15933 Defaults to @samp{#f}.
15940 @c %end of automatic openvpn-server documentation
15943 @node Network File System
15944 @subsubsection Network File System
15947 The @code{(gnu services nfs)} module provides the following services,
15948 which are most commonly used in relation to mounting or exporting
15949 directory trees as @dfn{network file systems} (NFS).
15951 @subsubheading RPC Bind Service
15954 The RPC Bind service provides a facility to map program numbers into
15955 universal addresses.
15956 Many NFS related services use this facility. Hence it is automatically
15957 started when a dependent service starts.
15959 @defvr {Scheme Variable} rpcbind-service-type
15960 A service type for the RPC portmapper daemon.
15964 @deftp {Data Type} rpcbind-configuration
15965 Data type representing the configuration of the RPC Bind Service.
15966 This type has the following parameters:
15968 @item @code{rpcbind} (default: @code{rpcbind})
15969 The rpcbind package to use.
15971 @item @code{warm-start?} (default: @code{#t})
15972 If this parameter is @code{#t}, then the daemon will read a
15973 state file on startup thus reloading state information saved by a previous
15979 @subsubheading Pipefs Pseudo File System
15983 The pipefs file system is used to transfer NFS related data
15984 between the kernel and user space programs.
15986 @defvr {Scheme Variable} pipefs-service-type
15987 A service type for the pipefs pseudo file system.
15990 @deftp {Data Type} pipefs-configuration
15991 Data type representing the configuration of the pipefs pseudo file system service.
15992 This type has the following parameters:
15994 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
15995 The directory to which the file system is to be attached.
16000 @subsubheading GSS Daemon Service
16003 @cindex global security system
16005 The @dfn{global security system} (GSS) daemon provides strong security for RPC
16007 Before exchanging RPC requests an RPC client must establish a security
16008 context. Typically this is done using the Kerberos command @command{kinit}
16009 or automatically at login time using PAM services (@pxref{Kerberos Services}).
16011 @defvr {Scheme Variable} gss-service-type
16012 A service type for the Global Security System (GSS) daemon.
16015 @deftp {Data Type} gss-configuration
16016 Data type representing the configuration of the GSS daemon service.
16017 This type has the following parameters:
16019 @item @code{nfs-utils} (default: @code{nfs-utils})
16020 The package in which the @command{rpc.gssd} command is to be found.
16022 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
16023 The directory where the pipefs file system is mounted.
16029 @subsubheading IDMAP Daemon Service
16031 @cindex name mapper
16033 The idmap daemon service provides mapping between user IDs and user names.
16034 Typically it is required in order to access file systems mounted via NFSv4.
16036 @defvr {Scheme Variable} idmap-service-type
16037 A service type for the Identity Mapper (IDMAP) daemon.
16040 @deftp {Data Type} idmap-configuration
16041 Data type representing the configuration of the IDMAP daemon service.
16042 This type has the following parameters:
16044 @item @code{nfs-utils} (default: @code{nfs-utils})
16045 The package in which the @command{rpc.idmapd} command is to be found.
16047 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
16048 The directory where the pipefs file system is mounted.
16050 @item @code{domain} (default: @code{#f})
16051 The local NFSv4 domain name.
16052 This must be a string or @code{#f}.
16053 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
16058 @node Continuous Integration
16059 @subsubsection Continuous Integration
16061 @cindex continuous integration
16062 @uref{https://notabug.org/mthl/cuirass, Cuirass} is a continuous
16063 integration tool for Guix. It can be used both for development and for
16064 providing substitutes to others (@pxref{Substitutes}).
16066 The @code{(gnu services cuirass)} module provides the following service.
16068 @defvr {Scheme Procedure} cuirass-service-type
16069 The type of the Cuirass service. Its value must be a
16070 @code{cuirass-configuration} object, as described below.
16073 To add build jobs, you have to set the @code{specifications} field of
16074 the configuration. Here is an example of a service defining a build job
16075 based on a specification that can be found in Cuirass source tree. This
16076 service polls the Guix repository and builds a subset of the Guix
16077 packages, as prescribed in the @file{gnu-system.scm} example spec:
16080 (let ((spec #~((#:name . "guix")
16081 (#:url . "git://git.savannah.gnu.org/guix.git")
16082 (#:load-path . ".")
16083 (#:file . "build-aux/cuirass/gnu-system.scm")
16084 (#:proc . cuirass-jobs)
16085 (#:arguments (subset . "hello"))
16086 (#:branch . "master"))))
16087 (service cuirass-service-type
16088 (cuirass-configuration
16089 (specifications #~(list '#$spec)))))
16092 While information related to build jobs is located directly in the
16093 specifications, global settings for the @command{cuirass} process are
16094 accessible in other @code{cuirass-configuration} fields.
16096 @deftp {Data Type} cuirass-configuration
16097 Data type representing the configuration of Cuirass.
16100 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
16101 Location of the log file.
16103 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
16104 Location of the repository cache.
16106 @item @code{user} (default: @code{"cuirass"})
16107 Owner of the @code{cuirass} process.
16109 @item @code{group} (default: @code{"cuirass"})
16110 Owner's group of the @code{cuirass} process.
16112 @item @code{interval} (default: @code{60})
16113 Number of seconds between the poll of the repositories followed by the
16116 @item @code{database} (default: @code{"/var/run/cuirass/cuirass.db"})
16117 Location of sqlite database which contains the build results and previously
16118 added specifications.
16120 @item @code{port} (default: @code{8081})
16121 Port number used by the HTTP server.
16123 @item --listen=@var{host}
16124 Listen on the network interface for @var{host}. The default is to
16125 accept connections from localhost.
16127 @item @code{specifications} (default: @code{#~'()})
16128 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
16129 where a specification is an association list
16130 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
16131 keys are keywords (@code{#:keyword-example}) as shown in the example
16134 @item @code{use-substitutes?} (default: @code{#f})
16135 This allows using substitutes to avoid building every dependencies of a job
16138 @item @code{one-shot?} (default: @code{#f})
16139 Only evaluate specifications and build derivations once.
16141 @item @code{fallback?} (default: @code{#f})
16142 When substituting a pre-built binary fails, fall back to building
16145 @item @code{load-path} (default: @code{'()})
16146 This allows users to define their own packages and make them visible to
16147 cuirass as in @command{guix build} command.
16149 @item @code{cuirass} (default: @code{cuirass})
16150 The Cuirass package to use.
16154 @node Power management Services
16155 @subsubsection Power management Services
16157 @cindex power management with TLP
16158 The @code{(gnu services pm)} module provides a Guix service definition
16159 for the Linux power management tool TLP.
16161 TLP enables various powersaving modes in userspace and kernel.
16162 Contrary to @code{upower-service}, it is not a passive,
16163 monitoring tool, as it will apply custom settings each time a new power
16164 source is detected. More information can be found at
16165 @uref{http://linrunner.de/en/tlp/tlp.html, TLP home page}.
16167 @deffn {Scheme Variable} tlp-service-type
16168 The service type for the TLP tool. Its value should be a valid
16169 TLP configuration (see below). To use the default settings, simply
16172 (service tlp-service-type)
16176 By default TLP does not need much configuration but most TLP parameters
16177 can be tweaked using @code{tlp-configuration}.
16179 Each parameter definition is preceded by its type; for example,
16180 @samp{boolean foo} indicates that the @code{foo} parameter
16181 should be specified as a boolean. Types starting with
16182 @code{maybe-} denote parameters that won't show up in TLP config file
16183 when their value is @code{'disabled}.
16185 @c The following documentation was initially generated by
16186 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
16187 @c documentation is better, so we shouldn't hesitate to edit below as
16188 @c needed. However if the change you want to make to this documentation
16189 @c can be done in an automated way, it's probably easier to change
16190 @c (generate-documentation) than to make it below and have to deal with
16191 @c the churn as TLP updates.
16193 Available @code{tlp-configuration} fields are:
16195 @deftypevr {@code{tlp-configuration} parameter} package tlp
16200 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
16201 Set to true if you wish to enable TLP.
16203 Defaults to @samp{#t}.
16207 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
16208 Default mode when no power supply can be detected. Alternatives are AC
16211 Defaults to @samp{"AC"}.
16215 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
16216 Number of seconds Linux kernel has to wait after the disk goes idle,
16217 before syncing on AC.
16219 Defaults to @samp{0}.
16223 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
16224 Same as @code{disk-idle-ac} but on BAT mode.
16226 Defaults to @samp{2}.
16230 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
16231 Dirty pages flushing periodicity, expressed in seconds.
16233 Defaults to @samp{15}.
16237 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
16238 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
16240 Defaults to @samp{60}.
16244 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
16245 CPU frequency scaling governor on AC mode. With intel_pstate driver,
16246 alternatives are powersave and performance. With acpi-cpufreq driver,
16247 alternatives are ondemand, powersave, performance and conservative.
16249 Defaults to @samp{disabled}.
16253 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
16254 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
16256 Defaults to @samp{disabled}.
16260 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
16261 Set the min available frequency for the scaling governor on AC.
16263 Defaults to @samp{disabled}.
16267 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
16268 Set the max available frequency for the scaling governor on AC.
16270 Defaults to @samp{disabled}.
16274 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
16275 Set the min available frequency for the scaling governor on BAT.
16277 Defaults to @samp{disabled}.
16281 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
16282 Set the max available frequency for the scaling governor on BAT.
16284 Defaults to @samp{disabled}.
16288 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
16289 Limit the min P-state to control the power dissipation of the CPU, in AC
16290 mode. Values are stated as a percentage of the available performance.
16292 Defaults to @samp{disabled}.
16296 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
16297 Limit the max P-state to control the power dissipation of the CPU, in AC
16298 mode. Values are stated as a percentage of the available performance.
16300 Defaults to @samp{disabled}.
16304 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
16305 Same as @code{cpu-min-perf-on-ac} on BAT mode.
16307 Defaults to @samp{disabled}.
16311 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
16312 Same as @code{cpu-max-perf-on-ac} on BAT mode.
16314 Defaults to @samp{disabled}.
16318 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
16319 Enable CPU turbo boost feature on AC mode.
16321 Defaults to @samp{disabled}.
16325 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
16326 Same as @code{cpu-boost-on-ac?} on BAT mode.
16328 Defaults to @samp{disabled}.
16332 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
16333 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
16334 used under light load conditions.
16336 Defaults to @samp{#f}.
16340 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
16341 Same as @code{sched-powersave-on-ac?} but on BAT mode.
16343 Defaults to @samp{#t}.
16347 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
16348 Enable Linux kernel NMI watchdog.
16350 Defaults to @samp{#f}.
16354 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
16355 For Linux kernels with PHC patch applied, change CPU voltages. An
16356 example value would be @samp{"F:V F:V F:V F:V"}.
16358 Defaults to @samp{disabled}.
16362 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
16363 Set CPU performance versus energy saving policy on AC. Alternatives are
16364 performance, normal, powersave.
16366 Defaults to @samp{"performance"}.
16370 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
16371 Same as @code{energy-perf-policy-ac} but on BAT mode.
16373 Defaults to @samp{"powersave"}.
16377 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
16382 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
16383 Hard disk advanced power management level.
16387 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
16388 Same as @code{disk-apm-bat} but on BAT mode.
16392 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
16393 Hard disk spin down timeout. One value has to be specified for each
16394 declared hard disk.
16396 Defaults to @samp{disabled}.
16400 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
16401 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
16403 Defaults to @samp{disabled}.
16407 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
16408 Select IO scheduler for disk devices. One value has to be specified for
16409 each declared hard disk. Example alternatives are cfq, deadline and
16412 Defaults to @samp{disabled}.
16416 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
16417 SATA aggressive link power management (ALPM) level. Alternatives are
16418 min_power, medium_power, max_performance.
16420 Defaults to @samp{"max_performance"}.
16424 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
16425 Same as @code{sata-linkpwr-ac} but on BAT mode.
16427 Defaults to @samp{"min_power"}.
16431 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
16432 Exclude specified SATA host devices for link power management.
16434 Defaults to @samp{disabled}.
16438 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
16439 Enable Runtime Power Management for AHCI controller and disks on AC
16442 Defaults to @samp{disabled}.
16446 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
16447 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
16449 Defaults to @samp{disabled}.
16453 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
16454 Seconds of inactivity before disk is suspended.
16456 Defaults to @samp{15}.
16460 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
16461 PCI Express Active State Power Management level. Alternatives are
16462 default, performance, powersave.
16464 Defaults to @samp{"performance"}.
16468 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
16469 Same as @code{pcie-aspm-ac} but on BAT mode.
16471 Defaults to @samp{"powersave"}.
16475 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
16476 Radeon graphics clock speed level. Alternatives are low, mid, high,
16479 Defaults to @samp{"high"}.
16483 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
16484 Same as @code{radeon-power-ac} but on BAT mode.
16486 Defaults to @samp{"low"}.
16490 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
16491 Radeon dynamic power management method (DPM). Alternatives are battery,
16494 Defaults to @samp{"performance"}.
16498 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
16499 Same as @code{radeon-dpm-state-ac} but on BAT mode.
16501 Defaults to @samp{"battery"}.
16505 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
16506 Radeon DPM performance level. Alternatives are auto, low, high.
16508 Defaults to @samp{"auto"}.
16512 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
16513 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
16515 Defaults to @samp{"auto"}.
16519 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
16520 Wifi power saving mode.
16522 Defaults to @samp{#f}.
16526 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
16527 Same as @code{wifi-power-ac?} but on BAT mode.
16529 Defaults to @samp{#t}.
16533 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
16534 Disable wake on LAN.
16536 Defaults to @samp{#t}.
16540 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
16541 Timeout duration in seconds before activating audio power saving on
16542 Intel HDA and AC97 devices. A value of 0 disables power saving.
16544 Defaults to @samp{0}.
16548 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
16549 Same as @code{sound-powersave-ac} but on BAT mode.
16551 Defaults to @samp{1}.
16555 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
16556 Disable controller in powersaving mode on Intel HDA devices.
16558 Defaults to @samp{#t}.
16562 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
16563 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
16564 powered on again by releasing (and reinserting) the eject lever or by
16565 pressing the disc eject button on newer models.
16567 Defaults to @samp{#f}.
16571 @deftypevr {@code{tlp-configuration} parameter} string bay-device
16572 Name of the optical drive device to power off.
16574 Defaults to @samp{"sr0"}.
16578 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
16579 Runtime Power Management for PCI(e) bus devices. Alternatives are on
16582 Defaults to @samp{"on"}.
16586 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
16587 Same as @code{runtime-pm-ac} but on BAT mode.
16589 Defaults to @samp{"auto"}.
16593 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
16594 Runtime Power Management for all PCI(e) bus devices, except blacklisted
16597 Defaults to @samp{#t}.
16601 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
16602 Exclude specified PCI(e) device addresses from Runtime Power Management.
16604 Defaults to @samp{disabled}.
16608 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
16609 Exclude PCI(e) devices assigned to the specified drivers from Runtime
16614 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
16615 Enable USB autosuspend feature.
16617 Defaults to @samp{#t}.
16621 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
16622 Exclude specified devices from USB autosuspend.
16624 Defaults to @samp{disabled}.
16628 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
16629 Exclude WWAN devices from USB autosuspend.
16631 Defaults to @samp{#t}.
16635 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
16636 Include specified devices into USB autosuspend, even if they are already
16637 excluded by the driver or via @code{usb-blacklist-wwan?}.
16639 Defaults to @samp{disabled}.
16643 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
16644 Enable USB autosuspend before shutdown.
16646 Defaults to @samp{disabled}.
16650 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
16651 Restore radio device state (bluetooth, wifi, wwan) from previous
16652 shutdown on system startup.
16654 Defaults to @samp{#f}.
16659 The @code{(gnu services pm)} module provides an interface to
16660 thermald, a CPU frequency scaling service which helps prevent overheating.
16662 @defvr {Scheme Variable} thermald-service-type
16663 This is the service type for
16664 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
16665 Thermal Daemon, which is responsible for controlling the thermal state
16666 of processors and preventing overheating.
16669 @deftp {Data Type} thermald-configuration
16670 Data type representing the configuration of @code{thermald-service-type}.
16673 @item @code{ignore-cpuid-check?} (default: @code{#f})
16674 Ignore cpuid check for supported CPU models.
16676 @item @code{thermald} (default: @var{thermald})
16677 Package object of thermald.
16682 @node Audio Services
16683 @subsubsection Audio Services
16685 The @code{(gnu services audio)} module provides a service to start MPD
16686 (the Music Player Daemon).
16689 @subsubheading Music Player Daemon
16691 The Music Player Daemon (MPD) is a service that can play music while
16692 being controlled from the local machine or over the network by a variety
16695 The following example shows how one might run @code{mpd} as user
16696 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
16699 (service mpd-service-type
16705 @defvr {Scheme Variable} mpd-service-type
16706 The service type for @command{mpd}
16709 @deftp {Data Type} mpd-configuration
16710 Data type representing the configuration of @command{mpd}.
16713 @item @code{user} (default: @code{"mpd"})
16714 The user to run mpd as.
16716 @item @code{music-dir} (default: @code{"~/Music"})
16717 The directory to scan for music files.
16719 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
16720 The directory to store playlists.
16722 @item @code{port} (default: @code{"6600"})
16723 The port to run mpd on.
16725 @item @code{address} (default: @code{"any"})
16726 The address that mpd will bind to. To use a Unix domain socket,
16727 an absolute path can be specified here.
16732 @node Virtualization Services
16733 @subsubsection Virtualization services
16734 The @code{(gnu services virtualization)} module provides services for
16735 the libvirt and virtlog daemons.
16737 @subsubheading Libvirt daemon
16738 @code{libvirtd} is the server side daemon component of the libvirt
16739 virtualization management system. This daemon runs on host servers
16740 and performs required management tasks for virtualized guests.
16742 @deffn {Scheme Variable} libvirt-service-type
16743 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
16744 Its value must be a @code{libvirt-configuration}.
16747 (service libvirt-service-type
16748 (libvirt-configuration
16749 (unix-sock-group "libvirt")
16750 (tls-port "16555")))
16754 @c Auto-generated with (generate-libvirt-documentation)
16755 Available @code{libvirt-configuration} fields are:
16757 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
16762 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
16763 Flag listening for secure TLS connections on the public TCP/IP port.
16764 must set @code{listen} for this to have any effect.
16766 It is necessary to setup a CA and issue server certificates before using
16769 Defaults to @samp{#t}.
16773 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
16774 Listen for unencrypted TCP connections on the public TCP/IP port. must
16775 set @code{listen} for this to have any effect.
16777 Using the TCP socket requires SASL authentication by default. Only SASL
16778 mechanisms which support data encryption are allowed. This is
16779 DIGEST_MD5 and GSSAPI (Kerberos5)
16781 Defaults to @samp{#f}.
16785 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
16786 Port for accepting secure TLS connections This can be a port number, or
16789 Defaults to @samp{"16514"}.
16793 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
16794 Port for accepting insecure TCP connections This can be a port number,
16797 Defaults to @samp{"16509"}.
16801 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
16802 IP address or hostname used for client connections.
16804 Defaults to @samp{"0.0.0.0"}.
16808 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
16809 Flag toggling mDNS advertisement of the libvirt service.
16811 Alternatively can disable for all services on a host by stopping the
16814 Defaults to @samp{#f}.
16818 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
16819 Default mDNS advertisement name. This must be unique on the immediate
16822 Defaults to @samp{"Virtualization Host <hostname>"}.
16826 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
16827 UNIX domain socket group ownership. This can be used to allow a
16828 'trusted' set of users access to management capabilities without
16831 Defaults to @samp{"root"}.
16835 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
16836 UNIX socket permissions for the R/O socket. This is used for monitoring
16839 Defaults to @samp{"0777"}.
16843 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
16844 UNIX socket permissions for the R/W socket. Default allows only root.
16845 If PolicyKit is enabled on the socket, the default will change to allow
16846 everyone (eg, 0777)
16848 Defaults to @samp{"0770"}.
16852 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
16853 UNIX socket permissions for the admin socket. Default allows only owner
16854 (root), do not change it unless you are sure to whom you are exposing
16857 Defaults to @samp{"0777"}.
16861 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
16862 The directory in which sockets will be found/created.
16864 Defaults to @samp{"/var/run/libvirt"}.
16868 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
16869 Authentication scheme for UNIX read-only sockets. By default socket
16870 permissions allow anyone to connect
16872 Defaults to @samp{"polkit"}.
16876 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
16877 Authentication scheme for UNIX read-write sockets. By default socket
16878 permissions only allow root. If PolicyKit support was compiled into
16879 libvirt, the default will be to use 'polkit' auth.
16881 Defaults to @samp{"polkit"}.
16885 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
16886 Authentication scheme for TCP sockets. If you don't enable SASL, then
16887 all TCP traffic is cleartext. Don't do this outside of a dev/test
16890 Defaults to @samp{"sasl"}.
16894 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
16895 Authentication scheme for TLS sockets. TLS sockets already have
16896 encryption provided by the TLS layer, and limited authentication is done
16899 It is possible to make use of any SASL authentication mechanism as well,
16900 by using 'sasl' for this option
16902 Defaults to @samp{"none"}.
16906 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
16907 API access control scheme.
16909 By default an authenticated user is allowed access to all APIs. Access
16910 drivers can place restrictions on this.
16912 Defaults to @samp{()}.
16916 @deftypevr {@code{libvirt-configuration} parameter} string key-file
16917 Server key file path. If set to an empty string, then no private key is
16920 Defaults to @samp{""}.
16924 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
16925 Server key file path. If set to an empty string, then no certificate is
16928 Defaults to @samp{""}.
16932 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
16933 Server key file path. If set to an empty string, then no CA certificate
16936 Defaults to @samp{""}.
16940 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
16941 Certificate revocation list path. If set to an empty string, then no
16944 Defaults to @samp{""}.
16948 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
16949 Disable verification of our own server certificates.
16951 When libvirtd starts it performs some sanity checks against its own
16954 Defaults to @samp{#f}.
16958 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
16959 Disable verification of client certificates.
16961 Client certificate verification is the primary authentication mechanism.
16962 Any client which does not present a certificate signed by the CA will be
16965 Defaults to @samp{#f}.
16969 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
16970 Whitelist of allowed x509 Distinguished Name.
16972 Defaults to @samp{()}.
16976 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
16977 Whitelist of allowed SASL usernames. The format for username depends on
16978 the SASL authentication mechanism.
16980 Defaults to @samp{()}.
16984 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
16985 Override the compile time default TLS priority string. The default is
16986 usually "NORMAL" unless overridden at build time. Only set this is it
16987 is desired for libvirt to deviate from the global default settings.
16989 Defaults to @samp{"NORMAL"}.
16993 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
16994 Maximum number of concurrent client connections to allow over all
16997 Defaults to @samp{5000}.
17001 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
17002 Maximum length of queue of connections waiting to be accepted by the
17003 daemon. Note, that some protocols supporting retransmission may obey
17004 this so that a later reattempt at connection succeeds.
17006 Defaults to @samp{1000}.
17010 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
17011 Maximum length of queue of accepted but not yet authenticated clients.
17012 Set this to zero to turn this feature off
17014 Defaults to @samp{20}.
17018 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
17019 Number of workers to start up initially.
17021 Defaults to @samp{5}.
17025 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
17026 Maximum number of worker threads.
17028 If the number of active clients exceeds @code{min-workers}, then more
17029 threads are spawned, up to max_workers limit. Typically you'd want
17030 max_workers to equal maximum number of clients allowed.
17032 Defaults to @samp{20}.
17036 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
17037 Number of priority workers. If all workers from above pool are stuck,
17038 some calls marked as high priority (notably domainDestroy) can be
17039 executed in this pool.
17041 Defaults to @samp{5}.
17045 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
17046 Total global limit on concurrent RPC calls.
17048 Defaults to @samp{20}.
17052 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
17053 Limit on concurrent requests from a single client connection. To avoid
17054 one client monopolizing the server this should be a small fraction of
17055 the global max_requests and max_workers parameter.
17057 Defaults to @samp{5}.
17061 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
17062 Same as @code{min-workers} but for the admin interface.
17064 Defaults to @samp{1}.
17068 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
17069 Same as @code{max-workers} but for the admin interface.
17071 Defaults to @samp{5}.
17075 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
17076 Same as @code{max-clients} but for the admin interface.
17078 Defaults to @samp{5}.
17082 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
17083 Same as @code{max-queued-clients} but for the admin interface.
17085 Defaults to @samp{5}.
17089 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
17090 Same as @code{max-client-requests} but for the admin interface.
17092 Defaults to @samp{5}.
17096 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
17097 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
17099 Defaults to @samp{3}.
17103 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
17106 A filter allows to select a different logging level for a given category
17107 of logs The format for a filter is one of:
17118 where @code{name} is a string which is matched against the category
17119 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
17120 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
17121 be a substring of the full category name, in order to match multiple
17122 similar categories), the optional "+" prefix tells libvirt to log stack
17123 trace for each message matching name, and @code{x} is the minimal level
17124 where matching messages should be logged:
17141 Multiple filters can be defined in a single filters statement, they just
17142 need to be separated by spaces.
17144 Defaults to @samp{"3:remote 4:event"}.
17148 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
17151 An output is one of the places to save logging information The format
17152 for an output can be:
17156 output goes to stderr
17158 @item x:syslog:name
17159 use syslog for the output and use the given name as the ident
17161 @item x:file:file_path
17162 output to a file, with the given filepath
17165 output to journald logging system
17169 In all case the x prefix is the minimal level, acting as a filter
17186 Multiple outputs can be defined, they just need to be separated by
17189 Defaults to @samp{"3:stderr"}.
17193 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
17194 Allows usage of the auditing subsystem to be altered
17198 0: disable all auditing
17201 1: enable auditing, only if enabled on host
17204 2: enable auditing, and exit if disabled on host.
17208 Defaults to @samp{1}.
17212 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
17213 Send audit messages via libvirt logging infrastructure.
17215 Defaults to @samp{#f}.
17219 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
17220 Host UUID. UUID must not have all digits be the same.
17222 Defaults to @samp{""}.
17226 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
17227 Source to read host UUID.
17231 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
17234 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
17238 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
17241 Defaults to @samp{"smbios"}.
17245 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
17246 A keepalive message is sent to a client after @code{keepalive_interval}
17247 seconds of inactivity to check if the client is still responding. If
17248 set to -1, libvirtd will never send keepalive requests; however clients
17249 can still send them and the daemon will send responses.
17251 Defaults to @samp{5}.
17255 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
17256 Maximum number of keepalive messages that are allowed to be sent to the
17257 client without getting any response before the connection is considered
17260 In other words, the connection is automatically closed approximately
17261 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
17262 the last message received from the client. When @code{keepalive-count}
17263 is set to 0, connections will be automatically closed after
17264 @code{keepalive-interval} seconds of inactivity without sending any
17265 keepalive messages.
17267 Defaults to @samp{5}.
17271 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
17272 Same as above but for admin interface.
17274 Defaults to @samp{5}.
17278 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
17279 Same as above but for admin interface.
17281 Defaults to @samp{5}.
17285 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
17286 Timeout for Open vSwitch calls.
17288 The @code{ovs-vsctl} utility is used for the configuration and its
17289 timeout option is set by default to 5 seconds to avoid potential
17290 infinite waits blocking libvirt.
17292 Defaults to @samp{5}.
17296 @c %end of autogenerated docs
17298 @subsubheading Virtlog daemon
17299 The virtlogd service is a server side daemon component of libvirt that is
17300 used to manage logs from virtual machine consoles.
17302 This daemon is not used directly by libvirt client applications, rather it
17303 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
17304 standalone daemon, the main @code{libvirtd} daemon can be restarted without
17305 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
17306 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
17308 @deffn {Scheme Variable} virtlog-service-type
17309 This is the type of the virtlog daemon.
17310 Its value must be a @code{virtlog-configuration}.
17313 (service virtlog-service-type
17314 (virtlog-configuration
17315 (max-clients 1000)))
17319 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
17320 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
17322 Defaults to @samp{3}.
17326 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
17329 A filter allows to select a different logging level for a given category
17330 of logs The format for a filter is one of:
17341 where @code{name} is a string which is matched against the category
17342 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
17343 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
17344 be a substring of the full category name, in order to match multiple
17345 similar categories), the optional "+" prefix tells libvirt to log stack
17346 trace for each message matching name, and @code{x} is the minimal level
17347 where matching messages should be logged:
17364 Multiple filters can be defined in a single filters statement, they just
17365 need to be separated by spaces.
17367 Defaults to @samp{"3:remote 4:event"}.
17371 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
17374 An output is one of the places to save logging information The format
17375 for an output can be:
17379 output goes to stderr
17381 @item x:syslog:name
17382 use syslog for the output and use the given name as the ident
17384 @item x:file:file_path
17385 output to a file, with the given filepath
17388 output to journald logging system
17392 In all case the x prefix is the minimal level, acting as a filter
17409 Multiple outputs can be defined, they just need to be separated by
17412 Defaults to @samp{"3:stderr"}.
17416 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
17417 Maximum number of concurrent client connections to allow over all
17420 Defaults to @samp{1024}.
17424 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
17425 Maximum file size before rolling over.
17427 Defaults to @samp{2MB}
17431 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
17432 Maximum number of backup files to keep.
17434 Defaults to @samp{3}
17439 @node Version Control Services
17440 @subsubsection Version Control Services
17442 The @code{(gnu services version-control)} module provides a service to
17443 allow remote access to local Git repositories. There are two options:
17444 the @code{git-daemon-service}, which provides access to repositories via
17445 the @code{git://} unsecured TCP-based protocol, or extending the
17446 @code{nginx} web server to proxy some requests to
17447 @code{git-http-backend}.
17449 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
17451 Return a service that runs @command{git daemon}, a simple TCP server to
17452 expose repositories over the Git protocol for anonymous access.
17454 The optional @var{config} argument should be a
17455 @code{<git-daemon-configuration>} object, by default it allows read-only
17456 access to exported@footnote{By creating the magic file
17457 "git-daemon-export-ok" in the repository directory.} repositories under
17462 @deftp {Data Type} git-daemon-configuration
17463 Data type representing the configuration for @code{git-daemon-service}.
17466 @item @code{package} (default: @var{git})
17467 Package object of the Git distributed version control system.
17469 @item @code{export-all?} (default: @var{#f})
17470 Whether to allow access for all Git repositories, even if they do not
17471 have the @file{git-daemon-export-ok} file.
17473 @item @code{base-path} (default: @file{/srv/git})
17474 Whether to remap all the path requests as relative to the given path.
17475 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
17476 then if you later try to pull @code{git://example.com/hello.git}, git
17477 daemon will interpret the path as @code{/srv/git/hello.git}.
17479 @item @code{user-path} (default: @var{#f})
17480 Whether to allow @code{~user} notation to be used in requests. When
17481 specified with empty string, requests to @code{git://host/~alice/foo} is
17482 taken as a request to access @code{foo} repository in the home directory
17483 of user @code{alice}. If @var{(user-path "path")} is specified, the
17484 same request is taken as a request to access @code{path/foo} repository
17485 in the home directory of user @code{alice}.
17487 @item @code{listen} (default: @var{'()})
17488 Whether to listen on specific IP addresses or hostnames, defaults to
17491 @item @code{port} (default: @var{#f})
17492 Whether to listen on an alternative port, which defaults to 9418.
17494 @item @code{whitelist} (default: @var{'()})
17495 If not empty, only allow access to this list of directories.
17497 @item @code{extra-options} (default: @var{'()})
17498 Extra options will be passed to @code{git daemon}, please run
17499 @command{man git-daemon} for more information.
17504 The @code{git://} protocol lacks authentication. When you pull from a
17505 repository fetched via @code{git://}, you don't know that the data you
17506 receive was modified is really coming from the specified host, and you
17507 have your connection is subject to eavesdropping. It's better to use an
17508 authenticated and encrypted transport, such as @code{https}. Although Git allows you
17509 to serve repositories using unsophisticated file-based web servers,
17510 there is a faster protocol implemented by the @code{git-http-backend}
17511 program. This program is the back-end of a proper Git web service. It
17512 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
17513 on running the necessary @code{fcgiwrap} daemon.
17515 Guix has a separate configuration data type for serving Git repositories
17518 @deftp {Data Type} git-http-configuration
17519 Data type representing the configuration for @code{git-http-service}.
17522 @item @code{package} (default: @var{git})
17523 Package object of the Git distributed version control system.
17525 @item @code{git-root} (default: @file{/srv/git})
17526 Directory containing the Git repositories to expose to the world.
17528 @item @code{export-all?} (default: @var{#f})
17529 Whether to expose access for all Git repositories in @var{git-root},
17530 even if they do not have the @file{git-daemon-export-ok} file.
17532 @item @code{uri-path} (default: @file{/git/})
17533 Path prefix for Git access. With the default @code{/git/} prefix, this
17534 will map @code{http://@var{server}/git/@var{repo}.git} to
17535 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
17536 with this prefix are not passed on to this Git instance.
17538 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
17539 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
17544 There is no @code{git-http-service-type}, currently; instead you can
17545 create an @code{nginx-location-configuration} from a
17546 @code{git-http-configuration} and then add that location to a web
17549 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
17550 [config=(git-http-configuration)]
17551 Compute an @code{nginx-location-configuration} that corresponds to the
17552 given Git http configuration. An example nginx service definition to
17553 serve the default @file{/srv/git} over HTTPS might be:
17556 (service nginx-service-type
17557 (nginx-configuration
17560 (nginx-server-configuration
17562 (server-name "git.my-host.org")
17564 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
17565 (ssl-certificate-key
17566 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
17569 (git-http-nginx-location-configuration
17570 (git-http-configuration (uri-path "/"))))))))))
17573 This example assumes that you are using Let's Encrypt to get your TLS
17574 certificate. @xref{Certificate Services}. The default @code{certbot}
17575 service will redirect all HTTP traffic on @code{git.my-host.org} to
17576 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
17577 system services. @xref{Web Services}.
17580 @node Miscellaneous Services
17581 @subsubsection Miscellaneous Services
17584 @subsubheading System Control Service
17586 The @code{(gnu services sysctl)} provides a service to configure kernel
17587 parameters at boot.
17589 @defvr {Scheme Variable} sysctl-service-type
17590 The service type for @command{sysctl}, which modifies kernel parameters
17591 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
17595 (service sysctl-service-type
17596 (sysctl-configuration
17597 (settings '(("net.ipv4.ip_forward" . "1")))))
17601 @deftp {Data Type} sysctl-configuration
17602 The data type representing the configuration of @command{sysctl}.
17605 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
17606 The @command{sysctl} executable to use.
17608 @item @code{settings} (default: @code{'()})
17609 An association list specifies kernel parameters and their values.
17614 @subsubheading Lirc Service
17616 The @code{(gnu services lirc)} module provides the following service.
17618 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
17619 [#:device #f] [#:driver #f] [#:config-file #f] @
17620 [#:extra-options '()]
17621 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
17622 decodes infrared signals from remote controls.
17624 Optionally, @var{device}, @var{driver} and @var{config-file}
17625 (configuration file name) may be specified. See @command{lircd} manual
17628 Finally, @var{extra-options} is a list of additional command-line options
17629 passed to @command{lircd}.
17633 @subsubheading Spice Service
17635 The @code{(gnu services spice)} module provides the following service.
17637 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
17638 Returns a service that runs @url{http://www.spice-space.org,VDAGENT}, a daemon
17639 that enables sharing the clipboard with a vm and setting the guest display
17640 resolution when the graphical console window resizes.
17643 @subsubsection Dictionary Services
17645 The @code{(gnu services dict)} module provides the following service:
17647 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
17648 Return a service that runs the @command{dicod} daemon, an implementation
17649 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
17651 The optional @var{config} argument specifies the configuration for
17652 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
17653 default it serves the GNU Collaborative International Dictonary of English.
17655 You can add @command{open localhost} to your @file{~/.dico} file to make
17656 @code{localhost} the default server for @command{dico} client
17657 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
17660 @deftp {Data Type} dicod-configuration
17661 Data type representing the configuration of dicod.
17664 @item @code{dico} (default: @var{dico})
17665 Package object of the GNU Dico dictionary server.
17667 @item @code{interfaces} (default: @var{'("localhost")})
17668 This is the list of IP addresses and ports and possibly socket file
17669 names to listen to (@pxref{Server Settings, @code{listen} directive,,
17670 dico, GNU Dico Manual}).
17672 @item @code{handlers} (default: @var{'()})
17673 List of @code{<dicod-handler>} objects denoting handlers (module instances).
17675 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
17676 List of @code{<dicod-database>} objects denoting dictionaries to be served.
17680 @deftp {Data Type} dicod-handler
17681 Data type representing a dictionary handler (module instance).
17685 Name of the handler (module instance).
17687 @item @code{module} (default: @var{#f})
17688 Name of the dicod module of the handler (instance). If it is @code{#f},
17689 the module has the same name as the handler.
17690 (@pxref{Modules,,, dico, GNU Dico Manual}).
17692 @item @code{options}
17693 List of strings or gexps representing the arguments for the module handler
17697 @deftp {Data Type} dicod-database
17698 Data type representing a dictionary database.
17702 Name of the database, will be used in DICT commands.
17704 @item @code{handler}
17705 Name of the dicod handler (module instance) used by this database
17706 (@pxref{Handlers,,, dico, GNU Dico Manual}).
17708 @item @code{complex?} (default: @var{#f})
17709 Whether the database configuration complex. The complex configuration
17710 will need a corresponding @code{<dicod-handler>} object, otherwise not.
17712 @item @code{options}
17713 List of strings or gexps representing the arguments for the database
17714 (@pxref{Databases,,, dico, GNU Dico Manual}).
17718 @defvr {Scheme Variable} %dicod-database:gcide
17719 A @code{<dicod-database>} object serving the GNU Collaborative International
17720 Dictionary of English using the @code{gcide} package.
17723 The following is an example @code{dicod-service} configuration.
17726 (dicod-service #:config
17727 (dicod-configuration
17728 (handlers (list (dicod-handler
17732 (list #~(string-append "dbdir=" #$wordnet))))))
17733 (databases (list (dicod-database
17736 (handler "wordnet")
17737 (options '("database=wn")))
17738 %dicod-database:gcide))))
17742 @subsubheading Cgit Service
17744 @cindex Cgit service
17745 @cindex Git, web interface
17746 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
17747 repositories written in C.
17749 The following example will configure the service with default values.
17750 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
17753 (service nginx-service-type)
17754 (service fcgiwrap-service-type)
17755 (service cgit-service-type)
17758 @deftp {Data Type} cgit-configuration
17759 Data type representing the configuration of Cgit.
17760 This type has the following parameters:
17763 @item @code{config-file} (default: @code{(cgit-configuration-file)})
17764 The configuration file to use for Cgit. This can be set to a
17765 @dfn{cgit-configuration-file} record value, or any gexp
17766 (@pxref{G-Expressions}).
17768 For example, to instead use a local file, the @code{local-file} function
17772 (service cgit-service-type
17773 (cgit-configuration
17774 (config-file (local-file "./my-cgitrc.conf"))))
17777 @item @code{package} (default: @code{cgit})
17778 The Cgit package to use.
17783 @deftp {Data Type} cgit-configuration-file
17784 Data type representing the configuration options for Cgit.
17785 This type has the following parameters:
17788 @item @code{css} (default: @code{"/share/cgit/cgit.css"})
17789 URL which specifies the css document to include in all Cgit pages.
17791 @item @code{logo} (default: @code{"/share/cgit/cgit.png"})
17792 URL which specifies the source of an image which will be used as a logo
17795 @item @code{virtual-root} (default: @code{"/"})
17796 URL which, if specified, will be used as root for all Cgit links.
17798 @item @code{repository-directory} (default: @code{"/srv/git"})
17799 Name of the directory to scan for repositories.
17801 @item @code{robots} (default: @code{(list "noindex" "nofollow")})
17802 Text used as content for the ``robots'' meta-tag.
17807 @node Setuid Programs
17808 @subsection Setuid Programs
17810 @cindex setuid programs
17811 Some programs need to run with ``root'' privileges, even when they are
17812 launched by unprivileged users. A notorious example is the
17813 @command{passwd} program, which users can run to change their
17814 password, and which needs to access the @file{/etc/passwd} and
17815 @file{/etc/shadow} files---something normally restricted to root, for
17816 obvious security reasons. To address that, these executables are
17817 @dfn{setuid-root}, meaning that they always run with root privileges
17818 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
17819 for more info about the setuid mechanism.)
17821 The store itself @emph{cannot} contain setuid programs: that would be a
17822 security issue since any user on the system can write derivations that
17823 populate the store (@pxref{The Store}). Thus, a different mechanism is
17824 used: instead of changing the setuid bit directly on files that are in
17825 the store, we let the system administrator @emph{declare} which programs
17826 should be setuid root.
17828 The @code{setuid-programs} field of an @code{operating-system}
17829 declaration contains a list of G-expressions denoting the names of
17830 programs to be setuid-root (@pxref{Using the Configuration System}).
17831 For instance, the @command{passwd} program, which is part of the Shadow
17832 package, can be designated by this G-expression (@pxref{G-Expressions}):
17835 #~(string-append #$shadow "/bin/passwd")
17838 A default set of setuid programs is defined by the
17839 @code{%setuid-programs} variable of the @code{(gnu system)} module.
17841 @defvr {Scheme Variable} %setuid-programs
17842 A list of G-expressions denoting common programs that are setuid-root.
17844 The list includes commands such as @command{passwd}, @command{ping},
17845 @command{su}, and @command{sudo}.
17848 Under the hood, the actual setuid programs are created in the
17849 @file{/run/setuid-programs} directory at system activation time. The
17850 files in this directory refer to the ``real'' binaries, which are in the
17853 @node X.509 Certificates
17854 @subsection X.509 Certificates
17856 @cindex HTTPS, certificates
17857 @cindex X.509 certificates
17859 Web servers available over HTTPS (that is, HTTP over the transport-layer
17860 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
17861 that the client can then use to @emph{authenticate} the server. To do
17862 that, clients verify that the server's certificate is signed by a
17863 so-called @dfn{certificate authority} (CA). But to verify the CA's
17864 signature, clients must have first acquired the CA's certificate.
17866 Web browsers such as GNU@tie{}IceCat include their own set of CA
17867 certificates, such that they are able to verify CA signatures
17870 However, most other programs that can talk HTTPS---@command{wget},
17871 @command{git}, @command{w3m}, etc.---need to be told where CA
17872 certificates can be found.
17874 @cindex @code{nss-certs}
17875 In GuixSD, this is done by adding a package that provides certificates
17876 to the @code{packages} field of the @code{operating-system} declaration
17877 (@pxref{operating-system Reference}). GuixSD includes one such package,
17878 @code{nss-certs}, which is a set of CA certificates provided as part of
17879 Mozilla's Network Security Services.
17881 Note that it is @emph{not} part of @var{%base-packages}, so you need to
17882 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
17883 most applications and libraries look for certificates by default, points
17884 to the certificates installed globally.
17886 Unprivileged users, including users of Guix on a foreign distro,
17887 can also install their own certificate package in
17888 their profile. A number of environment variables need to be defined so
17889 that applications and libraries know where to find them. Namely, the
17890 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
17891 variables. Some applications add their own environment variables; for
17892 instance, the Git version control system honors the certificate bundle
17893 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
17894 would typically run something like:
17897 $ guix package -i nss-certs
17898 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
17899 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
17900 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
17903 As another example, R requires the @code{CURL_CA_BUNDLE} environment
17904 variable to point to a certificate bundle, so you would have to run
17905 something like this:
17908 $ guix package -i nss-certs
17909 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
17912 For other applications you may want to look up the required environment
17913 variable in the relevant documentation.
17916 @node Name Service Switch
17917 @subsection Name Service Switch
17919 @cindex name service switch
17921 The @code{(gnu system nss)} module provides bindings to the
17922 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
17923 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
17924 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
17925 extended with new ``name'' lookup methods for system databases, which
17926 includes host names, service names, user accounts, and more (@pxref{Name
17927 Service Switch, System Databases and Name Service Switch,, libc, The GNU
17928 C Library Reference Manual}).
17930 The NSS configuration specifies, for each system database, which lookup
17931 method is to be used, and how the various methods are chained
17932 together---for instance, under which circumstances NSS should try the
17933 next method in the list. The NSS configuration is given in the
17934 @code{name-service-switch} field of @code{operating-system} declarations
17935 (@pxref{operating-system Reference, @code{name-service-switch}}).
17938 @cindex .local, host name lookup
17939 As an example, the declaration below configures the NSS to use the
17940 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
17941 back-end}, which supports host name lookups over multicast DNS (mDNS)
17942 for host names ending in @code{.local}:
17945 (name-service-switch
17946 (hosts (list %files ;first, check /etc/hosts
17948 ;; If the above did not succeed, try
17949 ;; with 'mdns_minimal'.
17951 (name "mdns_minimal")
17953 ;; 'mdns_minimal' is authoritative for
17954 ;; '.local'. When it returns "not found",
17955 ;; no need to try the next methods.
17956 (reaction (lookup-specification
17957 (not-found => return))))
17959 ;; Then fall back to DNS.
17963 ;; Finally, try with the "full" 'mdns'.
17968 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
17969 contains this configuration, so you will not have to type it if all you
17970 want is to have @code{.local} host lookup working.
17972 Note that, in this case, in addition to setting the
17973 @code{name-service-switch} of the @code{operating-system} declaration,
17974 you also need to use @code{avahi-service} (@pxref{Networking Services,
17975 @code{avahi-service}}), or @var{%desktop-services}, which includes it
17976 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
17977 to the name service cache daemon (@pxref{Base Services,
17978 @code{nscd-service}}).
17980 For convenience, the following variables provide typical NSS
17983 @defvr {Scheme Variable} %default-nss
17984 This is the default name service switch configuration, a
17985 @code{name-service-switch} object.
17988 @defvr {Scheme Variable} %mdns-host-lookup-nss
17989 This is the name service switch configuration with support for host name
17990 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
17993 The reference for name service switch configuration is given below. It
17994 is a direct mapping of the configuration file format of the C library , so
17995 please refer to the C library manual for more information (@pxref{NSS
17996 Configuration File,,, libc, The GNU C Library Reference Manual}).
17997 Compared to the configuration file format of libc NSS, it has the advantage
17998 not only of adding this warm parenthetic feel that we like, but also
17999 static checks: you will know about syntax errors and typos as soon as you
18000 run @command{guix system}.
18002 @deftp {Data Type} name-service-switch
18004 This is the data type representation the configuration of libc's name
18005 service switch (NSS). Each field below represents one of the supported
18022 The system databases handled by the NSS. Each of these fields must be a
18023 list of @code{<name-service>} objects (see below).
18027 @deftp {Data Type} name-service
18029 This is the data type representing an actual name service and the
18030 associated lookup action.
18034 A string denoting the name service (@pxref{Services in the NSS
18035 configuration,,, libc, The GNU C Library Reference Manual}).
18037 Note that name services listed here must be visible to nscd. This is
18038 achieved by passing the @code{#:name-services} argument to
18039 @code{nscd-service} the list of packages providing the needed name
18040 services (@pxref{Base Services, @code{nscd-service}}).
18043 An action specified using the @code{lookup-specification} macro
18044 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
18045 Reference Manual}). For example:
18048 (lookup-specification (unavailable => continue)
18049 (success => return))
18054 @node Initial RAM Disk
18055 @subsection Initial RAM Disk
18058 @cindex initial RAM disk
18059 For bootstrapping purposes, the Linux-Libre kernel is passed an
18060 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
18061 root file system as well as an initialization script. The latter is
18062 responsible for mounting the real root file system, and for loading any
18063 kernel modules that may be needed to achieve that.
18065 The @code{initrd} field of an @code{operating-system} declaration allows
18066 you to specify which initrd you would like to use. The @code{(gnu
18067 system linux-initrd)} module provides three ways to build an initrd: the
18068 high-level @code{base-initrd} procedure and the low-level
18069 @code{raw-initrd} and @code{expression->initrd} procedures.
18071 The @code{base-initrd} procedure is intended to cover most common uses.
18072 For example, if you want to add a bunch of kernel modules to be loaded
18073 at boot time, you can define the @code{initrd} field of the operating
18074 system declaration like this:
18077 (initrd (lambda (file-systems . rest)
18078 ;; Create a standard initrd that has modules "foo.ko"
18079 ;; and "bar.ko", as well as their dependencies, in
18080 ;; addition to the modules available by default.
18081 (apply base-initrd file-systems
18082 #:extra-modules '("foo" "bar")
18086 The @code{base-initrd} procedure also handles common use cases that
18087 involves using the system as a QEMU guest, or as a ``live'' system with
18088 volatile root file system.
18090 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
18091 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
18092 such as trying to guess which kernel modules and packages should be included
18093 to the initrd. An example use of @code{raw-initrd} is when a user has
18094 a custom Linux kernel configuration and default kernel modules included by
18095 @code{base-initrd} are not available.
18097 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
18098 honors several options passed on the Linux kernel command line
18099 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
18100 @code{-append} option of QEMU), notably:
18103 @item --load=@var{boot}
18104 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
18105 program, once it has mounted the root file system.
18107 GuixSD uses this option to yield control to a boot program that runs the
18108 service activation programs and then spawns the GNU@tie{}Shepherd, the
18109 initialization system.
18111 @item --root=@var{root}
18112 Mount @var{root} as the root file system. @var{root} can be a
18113 device name like @code{/dev/sda1}, a partition label, or a partition
18116 @item --system=@var{system}
18117 Have @file{/run/booted-system} and @file{/run/current-system} point to
18120 @item modprobe.blacklist=@var{modules}@dots{}
18121 @cindex module, black-listing
18122 @cindex black list, of kernel modules
18123 Instruct the initial RAM disk as well as the @command{modprobe} command
18124 (from the kmod package) to refuse to load @var{modules}. @var{modules}
18125 must be a comma-separated list of module names---e.g.,
18126 @code{usbkbd,9pnet}.
18129 Start a read-eval-print loop (REPL) from the initial RAM disk before it
18130 tries to load kernel modules and to mount the root file system. Our
18131 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
18132 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
18133 Manual}, for more information on Guile's REPL.
18137 Now that you know all the features that initial RAM disks produced by
18138 @code{base-initrd} and @code{raw-initrd} provide,
18139 here is how to use it and customize it further.
18142 @cindex initial RAM disk
18143 @deffn {Monadic Procedure} raw-initrd @var{file-systems} @
18144 [#:linux-modules '()] [#:mapped-devices '()] @
18145 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
18146 Return a monadic derivation that builds a raw initrd. @var{file-systems} is
18147 a list of file systems to be mounted by the initrd, possibly in addition to
18148 the root file system specified on the kernel command line via @code{--root}.
18149 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
18150 @var{mapped-devices} is a list of device mappings to realize before
18151 @var{file-systems} are mounted (@pxref{Mapped Devices}).
18152 @var{helper-packages} is a list of packages to be copied in the initrd. It may
18153 include @code{e2fsck/static} or other packages needed by the initrd to check
18156 When @var{qemu-networking?} is true, set up networking with the standard QEMU
18157 parameters. When @var{virtio?} is true, load additional modules so that the
18158 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
18160 When @var{volatile-root?} is true, the root file system is writable but any changes
18164 @deffn {Monadic Procedure} base-initrd @var{file-systems} @
18165 [#:mapped-devices '()] [#:qemu-networking? #f] [#:volatile-root? #f]@
18166 [#:virtio? #t] [#:extra-modules '()]
18167 Return a monadic derivation that builds a generic initrd. @var{file-systems} is
18168 a list of file systems to be mounted by the initrd like for @code{raw-initrd}.
18169 @var{mapped-devices}, @var{qemu-networking?} and @var{volatile-root?}
18170 also behaves as in @code{raw-initrd}.
18172 When @var{virtio?} is true, load additional modules so that the
18173 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
18175 The initrd is automatically populated with all the kernel modules necessary
18176 for @var{file-systems} and for the given options. However, additional kernel
18177 modules can be listed in @var{extra-modules}. They will be added to the initrd, and
18178 loaded at boot time in the order in which they appear.
18181 Needless to say, the initrds we produce and use embed a
18182 statically-linked Guile, and the initialization program is a Guile
18183 program. That gives a lot of flexibility. The
18184 @code{expression->initrd} procedure builds such an initrd, given the
18185 program to run in that initrd.
18187 @deffn {Monadic Procedure} expression->initrd @var{exp} @
18188 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
18189 Return a derivation that builds a Linux initrd (a gzipped cpio archive)
18190 containing @var{guile} and that evaluates @var{exp}, a G-expression,
18191 upon booting. All the derivations referenced by @var{exp} are
18192 automatically copied to the initrd.
18195 @node Bootloader Configuration
18196 @subsection Bootloader Configuration
18199 @cindex boot loader
18201 The operating system supports multiple bootloaders. The bootloader is
18202 configured using @code{bootloader-configuration} declaration. All the
18203 fields of this structure are bootloader agnostic except for one field,
18204 @code{bootloader} that indicates the bootloader to be configured and
18207 Some of the bootloaders do not honor every field of
18208 @code{bootloader-configuration}. For instance, the extlinux
18209 bootloader does not support themes and thus ignores the @code{theme}
18212 @deftp {Data Type} bootloader-configuration
18213 The type of a bootloader configuration declaration.
18217 @item @code{bootloader}
18218 @cindex EFI, bootloader
18219 @cindex UEFI, bootloader
18220 @cindex BIOS, bootloader
18221 The bootloader to use, as a @code{bootloader} object. For now
18222 @code{grub-bootloader}, @code{grub-efi-bootloader},
18223 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
18224 @code{grub-efi-bootloader} allows to boot on modern systems using the
18225 @dfn{Unified Extensible Firmware Interface} (UEFI).
18227 Available bootloaders are described in @code{(gnu bootloader @dots{})}
18230 @item @code{target}
18231 This is a string denoting the target onto which to install the
18232 bootloader. The exact interpretation depends on the bootloader in
18233 question; for @code{grub-bootloader}, for example, it should be a device
18234 name understood by the bootloader @command{installer} command, such as
18235 @code{/dev/sda} or @code{(hd0)} (for GRUB, @pxref{Invoking
18236 grub-install,,, grub, GNU GRUB Manual}). For
18237 @code{grub-efi-bootloader}, it should be the path to a mounted EFI file
18240 @item @code{menu-entries} (default: @code{()})
18241 A possibly empty list of @code{menu-entry} objects (see below), denoting
18242 entries to appear in the bootloader menu, in addition to the current
18243 system entry and the entry pointing to previous system generations.
18246 @item @code{default-entry} (default: @code{0})
18247 The index of the default boot menu entry. Index 0 is for the entry of the
18250 @item @code{timeout} (default: @code{5})
18251 The number of seconds to wait for keyboard input before booting. Set to
18252 0 to boot immediately, and to -1 to wait indefinitely.
18254 @item @code{theme} (default: @var{#f})
18255 The bootloader theme object describing the theme to use. If no theme
18256 is provided, some bootloaders might use a default theme, that's true
18259 @item @code{terminal-outputs} (default: @code{'gfxterm})
18260 The output terminals used for the bootloader boot menu, as a list of
18261 symbols. GRUB accepts the values: @code{console}, @code{serial},
18262 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
18263 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
18264 corresponds to the GRUB variable GRUB_TERMINAL_OUTPUT (@pxref{Simple
18265 configuration,,, grub,GNU GRUB manual}).
18267 @item @code{terminal-inputs} (default: @code{'()})
18268 The input terminals used for the bootloader boot menu, as a list of
18269 symbols. For GRUB, the default is the native platform terminal as
18270 determined at run-time. GRUB accepts the values: @code{console},
18271 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
18272 @code{usb_keyboard}. This field corresponds to the GRUB variable
18273 GRUB_TERMINAL_INPUT (@pxref{Simple configuration,,, grub,GNU GRUB
18276 @item @code{serial-unit} (default: @code{#f})
18277 The serial unit used by the bootloader, as an integer from 0 to 3.
18278 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
18279 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
18281 @item @code{serial-speed} (default: @code{#f})
18282 The speed of the serial interface, as an integer. For GRUB, the
18283 default value is chosen at run-time; currently GRUB chooses
18284 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
18291 Should you want to list additional boot menu entries @i{via} the
18292 @code{menu-entries} field above, you will need to create them with the
18293 @code{menu-entry} form. For example, imagine you want to be able to
18294 boot another distro (hard to imagine!), you can define a menu entry
18299 (label "The Other Distro")
18300 (linux "/boot/old/vmlinux-2.6.32")
18301 (linux-arguments '("root=/dev/sda2"))
18302 (initrd "/boot/old/initrd"))
18307 @deftp {Data Type} menu-entry
18308 The type of an entry in the bootloader menu.
18313 The label to show in the menu---e.g., @code{"GNU"}.
18316 The Linux kernel image to boot, for example:
18319 (file-append linux-libre "/bzImage")
18322 For GRUB, it is also possible to specify a device explicitly in the
18323 file path using GRUB's device naming convention (@pxref{Naming
18324 convention,,, grub, GNU GRUB manual}), for example:
18327 "(hd0,msdos1)/boot/vmlinuz"
18330 If the device is specified explicitly as above, then the @code{device}
18331 field is ignored entirely.
18333 @item @code{linux-arguments} (default: @code{()})
18334 The list of extra Linux kernel command-line arguments---e.g.,
18335 @code{("console=ttyS0")}.
18337 @item @code{initrd}
18338 A G-Expression or string denoting the file name of the initial RAM disk
18339 to use (@pxref{G-Expressions}).
18340 @item @code{device} (default: @code{#f})
18341 The device where the kernel and initrd are to be found---i.e., for GRUB,
18342 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
18344 This may be a file system label (a string), a file system UUID (a
18345 bytevector, @pxref{File Systems}), or @code{#f}, in which case
18346 the bootloader will search the device containing the file specified by
18347 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
18348 must @emph{not} be an OS device name such as @file{/dev/sda1}.
18353 @c FIXME: Write documentation once it's stable.
18354 Fow now only GRUB has theme support. GRUB themes are created using
18355 the @code{grub-theme} form, which is not documented yet.
18357 @defvr {Scheme Variable} %default-theme
18358 This is the default GRUB theme used by the operating system if no
18359 @code{theme} field is specified in @code{bootloader-configuration}
18362 It comes with a fancy background image displaying the GNU and Guix
18367 @node Invoking guix system
18368 @subsection Invoking @code{guix system}
18370 Once you have written an operating system declaration as seen in the
18371 previous section, it can be @dfn{instantiated} using the @command{guix
18372 system} command. The synopsis is:
18375 guix system @var{options}@dots{} @var{action} @var{file}
18378 @var{file} must be the name of a file containing an
18379 @code{operating-system} declaration. @var{action} specifies how the
18380 operating system is instantiated. Currently the following values are
18385 Display available service type definitions that match the given regular
18386 expressions, sorted by relevance:
18389 $ guix system search console font
18390 name: console-fonts
18391 location: gnu/services/base.scm:729:2
18392 extends: shepherd-root
18393 description: Install the given fonts on the specified ttys (fonts are
18394 + per virtual console on GNU/Linux). The value of this service is a list
18395 + of tty/font pairs like:
18397 + '(("tty1" . "LatGrkCyr-8x16"))
18401 location: gnu/services/base.scm:1048:2
18402 extends: shepherd-root
18403 description: Provide console login using the `mingetty' program.
18407 location: gnu/services/base.scm:775:2
18409 description: Provide a console log-in service as specified by its
18410 + configuration value, a `login-configuration' object.
18416 As for @command{guix package --search}, the result is written in
18417 @code{recutils} format, which makes it easy to filter the output
18418 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
18421 Build the operating system described in @var{file}, activate it, and
18422 switch to it@footnote{This action (and the related actions
18423 @code{switch-generation} and @code{roll-back}) are usable only on
18424 systems already running GuixSD.}.
18426 This effects all the configuration specified in @var{file}: user
18427 accounts, system services, global package list, setuid programs, etc.
18428 The command starts system services specified in @var{file} that are not
18429 currently running; if a service is currently running, it does not
18430 attempt to upgrade it since this would not be possible without stopping it
18433 This command creates a new generation whose number is one greater than
18434 the current generation (as reported by @command{guix system
18435 list-generations}). If that generation already exists, it will be
18436 overwritten. This behavior mirrors that of @command{guix package}
18437 (@pxref{Invoking guix package}).
18439 It also adds a bootloader menu entry for the new OS configuration,
18440 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
18441 entries for older configurations to a submenu, allowing you to choose
18442 an older system generation at boot time should you need it.
18445 @c The paragraph below refers to the problem discussed at
18446 @c <http://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
18447 It is highly recommended to run @command{guix pull} once before you run
18448 @command{guix system reconfigure} for the first time (@pxref{Invoking
18449 guix pull}). Failing to do that you would see an older version of Guix
18450 once @command{reconfigure} has completed.
18453 @item switch-generation
18454 @cindex generations
18455 Switch to an existing system generation. This action atomically
18456 switches the system profile to the specified system generation. It
18457 also rearranges the system's existing bootloader menu entries. It
18458 makes the menu entry for the specified system generation the default,
18459 and it moves the entries for the other generatiors to a submenu, if
18460 supported by the bootloader being used. The next time the system
18461 boots, it will use the specified system generation.
18463 The bootloader itself is not being reinstalled when using this
18464 command. Thus, the installed bootloader is used with an updated
18465 configuration file.
18467 The target generation can be specified explicitly by its generation
18468 number. For example, the following invocation would switch to system
18472 guix system switch-generation 7
18475 The target generation can also be specified relative to the current
18476 generation with the form @code{+N} or @code{-N}, where @code{+3} means
18477 ``3 generations ahead of the current generation,'' and @code{-1} means
18478 ``1 generation prior to the current generation.'' When specifying a
18479 negative value such as @code{-1}, you must precede it with @code{--} to
18480 prevent it from being parsed as an option. For example:
18483 guix system switch-generation -- -1
18486 Currently, the effect of invoking this action is @emph{only} to switch
18487 the system profile to an existing generation and rearrange the
18488 bootloader menu entries. To actually start using the target system
18489 generation, you must reboot after running this action. In the future,
18490 it will be updated to do the same things as @command{reconfigure},
18491 like activating and deactivating services.
18493 This action will fail if the specified generation does not exist.
18496 @cindex rolling back
18497 Switch to the preceding system generation. The next time the system
18498 boots, it will use the preceding system generation. This is the inverse
18499 of @command{reconfigure}, and it is exactly the same as invoking
18500 @command{switch-generation} with an argument of @code{-1}.
18502 Currently, as with @command{switch-generation}, you must reboot after
18503 running this action to actually start using the preceding system
18507 Build the derivation of the operating system, which includes all the
18508 configuration files and programs needed to boot and run the system.
18509 This action does not actually install anything.
18512 Populate the given directory with all the files necessary to run the
18513 operating system specified in @var{file}. This is useful for first-time
18514 installations of GuixSD. For instance:
18517 guix system init my-os-config.scm /mnt
18520 copies to @file{/mnt} all the store items required by the configuration
18521 specified in @file{my-os-config.scm}. This includes configuration
18522 files, packages, and so on. It also creates other essential files
18523 needed for the system to operate correctly---e.g., the @file{/etc},
18524 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
18526 This command also installs bootloader on the target specified in
18527 @file{my-os-config}, unless the @option{--no-bootloader} option was
18531 @cindex virtual machine
18533 @anchor{guix system vm}
18534 Build a virtual machine that contains the operating system declared in
18535 @var{file}, and return a script to run that virtual machine (VM).
18536 Arguments given to the script are passed to QEMU as in the example
18537 below, which enables networking and requests 1@tie{}GiB of RAM for the
18541 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
18544 The VM shares its store with the host system.
18546 Additional file systems can be shared between the host and the VM using
18547 the @code{--share} and @code{--expose} command-line options: the former
18548 specifies a directory to be shared with write access, while the latter
18549 provides read-only access to the shared directory.
18551 The example below creates a VM in which the user's home directory is
18552 accessible read-only, and where the @file{/exchange} directory is a
18553 read-write mapping of @file{$HOME/tmp} on the host:
18556 guix system vm my-config.scm \
18557 --expose=$HOME --share=$HOME/tmp=/exchange
18560 On GNU/Linux, the default is to boot directly to the kernel; this has
18561 the advantage of requiring only a very tiny root disk image since the
18562 store of the host can then be mounted.
18564 The @code{--full-boot} option forces a complete boot sequence, starting
18565 with the bootloader. This requires more disk space since a root image
18566 containing at least the kernel, initrd, and bootloader data files must
18567 be created. The @code{--image-size} option can be used to specify the
18572 Return a virtual machine or disk image of the operating system declared
18573 in @var{file} that stands alone. By default, @command{guix system}
18574 estimates the size of the image needed to store the system, but you can
18575 use the @option{--image-size} option to specify a value.
18577 You can specify the root file system type by using the
18578 @option{--file-system-type} option. It defaults to @code{ext4}.
18580 When using @code{vm-image}, the returned image is in qcow2 format, which
18581 the QEMU emulator can efficiently use. @xref{Running GuixSD in a VM},
18582 for more information on how to run the image in a virtual machine.
18584 When using @code{disk-image}, a raw disk image is produced; it can be
18585 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
18586 the device corresponding to a USB stick, one can copy the image to it
18587 using the following command:
18590 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
18594 Return a script to run the operating system declared in @var{file}
18595 within a container. Containers are a set of lightweight isolation
18596 mechanisms provided by the kernel Linux-libre. Containers are
18597 substantially less resource-demanding than full virtual machines since
18598 the kernel, shared objects, and other resources can be shared with the
18599 host system; this also means they provide thinner isolation.
18601 Currently, the script must be run as root in order to support more than
18602 a single user and group. The container shares its store with the host
18605 As with the @code{vm} action (@pxref{guix system vm}), additional file
18606 systems to be shared between the host and container can be specified
18607 using the @option{--share} and @option{--expose} options:
18610 guix system container my-config.scm \
18611 --expose=$HOME --share=$HOME/tmp=/exchange
18615 This option requires Linux-libre 3.19 or newer.
18620 @var{options} can contain any of the common build options (@pxref{Common
18621 Build Options}). In addition, @var{options} can contain one of the
18625 @item --system=@var{system}
18626 @itemx -s @var{system}
18627 Attempt to build for @var{system} instead of the host system type.
18628 This works as per @command{guix build} (@pxref{Invoking guix build}).
18632 Return the derivation file name of the given operating system without
18635 @item --file-system-type=@var{type}
18636 @itemx -t @var{type}
18637 For the @code{disk-image} action, create a file system of the given
18638 @var{type} on the image.
18640 When this option is omitted, @command{guix system} uses @code{ext4}.
18642 @cindex ISO-9660 format
18643 @cindex CD image format
18644 @cindex DVD image format
18645 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
18646 for burning on CDs and DVDs.
18648 @item --image-size=@var{size}
18649 For the @code{vm-image} and @code{disk-image} actions, create an image
18650 of the given @var{size}. @var{size} may be a number of bytes, or it may
18651 include a unit as a suffix (@pxref{Block size, size specifications,,
18652 coreutils, GNU Coreutils}).
18654 When this option is omitted, @command{guix system} computes an estimate
18655 of the image size as a function of the size of the system declared in
18658 @item --root=@var{file}
18659 @itemx -r @var{file}
18660 Make @var{file} a symlink to the result, and register it as a garbage
18663 @item --on-error=@var{strategy}
18664 Apply @var{strategy} when an error occurs when reading @var{file}.
18665 @var{strategy} may be one of the following:
18668 @item nothing-special
18669 Report the error concisely and exit. This is the default strategy.
18672 Likewise, but also display a backtrace.
18675 Report the error and enter Guile's debugger. From there, you can run
18676 commands such as @code{,bt} to get a backtrace, @code{,locals} to
18677 display local variable values, and more generally inspect the state of the
18678 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
18679 a list of available debugging commands.
18684 All the actions above, except @code{build} and @code{init},
18685 can use KVM support in the Linux-libre kernel. Specifically, if the
18686 machine has hardware virtualization support, the corresponding
18687 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
18688 must exist and be readable and writable by the user and by the
18689 build users of the daemon (@pxref{Build Environment Setup}).
18692 Once you have built, configured, re-configured, and re-re-configured
18693 your GuixSD installation, you may find it useful to list the operating
18694 system generations available on disk---and that you can choose from the
18695 bootloader boot menu:
18699 @item list-generations
18700 List a summary of each generation of the operating system available on
18701 disk, in a human-readable way. This is similar to the
18702 @option{--list-generations} option of @command{guix package}
18703 (@pxref{Invoking guix package}).
18705 Optionally, one can specify a pattern, with the same syntax that is used
18706 in @command{guix package --list-generations}, to restrict the list of
18707 generations displayed. For instance, the following command displays
18708 generations that are up to 10 days old:
18711 $ guix system list-generations 10d
18716 The @command{guix system} command has even more to offer! The following
18717 sub-commands allow you to visualize how your system services relate to
18720 @anchor{system-extension-graph}
18723 @item extension-graph
18724 Emit in Dot/Graphviz format to standard output the @dfn{service
18725 extension graph} of the operating system defined in @var{file}
18726 (@pxref{Service Composition}, for more information on service
18732 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
18735 produces a PDF file showing the extension relations among services.
18737 @anchor{system-shepherd-graph}
18738 @item shepherd-graph
18739 Emit in Dot/Graphviz format to standard output the @dfn{dependency
18740 graph} of shepherd services of the operating system defined in
18741 @var{file}. @xref{Shepherd Services}, for more information and for an
18746 @node Running GuixSD in a VM
18747 @subsection Running GuixSD in a Virtual Machine
18749 @cindex virtual machine
18750 To run GuixSD in a virtual machine (VM), one can either use the
18751 pre-built GuixSD VM image distributed at
18752 @indicateurl{ftp://alpha.gnu.org/guix/guixsd-vm-image-@value{VERSION}.@var{system}.tar.xz}
18753 , or build their own virtual machine image using @command{guix system
18754 vm-image} (@pxref{Invoking guix system}). The returned image is in
18755 qcow2 format, which the @uref{http://qemu.org/, QEMU emulator} can
18759 If you built your own image, you must copy it out of the store
18760 (@pxref{The Store}) and give yourself permission to write to the copy
18761 before you can use it. When invoking QEMU, you must choose a system
18762 emulator that is suitable for your hardware platform. Here is a minimal
18763 QEMU invocation that will boot the result of @command{guix system
18764 vm-image} on x86_64 hardware:
18767 $ qemu-system-x86_64 \
18768 -net user -net nic,model=virtio \
18769 -enable-kvm -m 256 /tmp/qemu-image
18772 Here is what each of these options means:
18775 @item qemu-system-x86_64
18776 This specifies the hardware platform to emulate. This should match the
18780 Enable the unprivileged user-mode network stack. The guest OS can
18781 access the host but not vice versa. This is the simplest way to get the
18784 @item -net nic,model=virtio
18785 You must create a network interface of a given model. If you do not
18786 create a NIC, the boot will fail. Assuming your hardware platform is
18787 x86_64, you can get a list of available NIC models by running
18788 @command{qemu-system-x86_64 -net nic,model=help}.
18791 If your system has hardware virtualization extensions, enabling the
18792 virtual machine support (KVM) of the Linux kernel will make things run
18796 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
18797 which may be insufficient for some operations.
18799 @item /tmp/qemu-image
18800 The file name of the qcow2 image.
18803 The default @command{run-vm.sh} script that is returned by an invocation of
18804 @command{guix system vm} does not add a @command{-net user} flag by default.
18805 To get network access from within the vm add the @code{(dhcp-client-service)}
18806 to your system definition and start the VM using
18807 @command{`guix system vm config.scm` -net user}. An important caveat of using
18808 @command{-net user} for networking is that @command{ping} will not work, because
18809 it uses the ICMP protocol. You'll have to use a different command to check for
18810 network connectivity, for example @command{guix download}.
18812 @subsubsection Connecting Through SSH
18816 To enable SSH inside a VM you need to add a SSH server like @code{(dropbear-service)}
18817 or @code{(lsh-service)} to your VM. The @code{(lsh-service}) doesn't currently
18818 boot unsupervised. It requires you to type some characters to initialize the
18819 randomness generator. In addition you need to forward the SSH port, 22 by
18820 default, to the host. You can do this with
18823 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
18826 To connect to the VM you can run
18829 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
18832 The @command{-p} tells @command{ssh} the port you want to connect to.
18833 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
18834 every time you modify your @command{config.scm} file and the
18835 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
18836 connection to an unknown host every time you connect.
18838 @subsubsection Using @command{virt-viewer} with Spice
18840 As an alternative to the default @command{qemu} graphical client you can
18841 use the @command{remote-viewer} from the @command{virt-viewer} package. To
18842 connect pass the @command{-spice port=5930,disable-ticketing} flag to
18843 @command{qemu}. See previous section for further information on how to do this.
18845 Spice also allows you to do some nice stuff like share your clipboard with your
18846 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
18849 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
18850 -chardev spicevmc,name=vdagent,id=vdagent
18851 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
18852 name=com.redhat.spice.0
18855 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
18857 @node Defining Services
18858 @subsection Defining Services
18860 The previous sections show the available services and how one can combine
18861 them in an @code{operating-system} declaration. But how do we define
18862 them in the first place? And what is a service anyway?
18865 * Service Composition:: The model for composing services.
18866 * Service Types and Services:: Types and services.
18867 * Service Reference:: API reference.
18868 * Shepherd Services:: A particular type of service.
18871 @node Service Composition
18872 @subsubsection Service Composition
18876 Here we define a @dfn{service} as, broadly, something that extends the
18877 functionality of the operating system. Often a service is a process---a
18878 @dfn{daemon}---started when the system boots: a secure shell server, a
18879 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
18880 whose execution can be triggered by another daemon---e.g., an FTP server
18881 started by @command{inetd} or a D-Bus service activated by
18882 @command{dbus-daemon}. Occasionally, a service does not map to a
18883 daemon. For instance, the ``account'' service collects user accounts
18884 and makes sure they exist when the system runs; the ``udev'' service
18885 collects device management rules and makes them available to the eudev
18886 daemon; the @file{/etc} service populates the @file{/etc} directory
18889 @cindex service extensions
18890 GuixSD services are connected by @dfn{extensions}. For instance, the
18891 secure shell service @emph{extends} the Shepherd---the GuixSD
18892 initialization system, running as PID@tie{}1---by giving it the command
18893 lines to start and stop the secure shell daemon (@pxref{Networking
18894 Services, @code{lsh-service}}); the UPower service extends the D-Bus
18895 service by passing it its @file{.service} specification, and extends the
18896 udev service by passing it device management rules (@pxref{Desktop
18897 Services, @code{upower-service}}); the Guix daemon service extends the
18898 Shepherd by passing it the command lines to start and stop the daemon,
18899 and extends the account service by passing it a list of required build
18900 user accounts (@pxref{Base Services}).
18902 All in all, services and their ``extends'' relations form a directed
18903 acyclic graph (DAG). If we represent services as boxes and extensions
18904 as arrows, a typical system might provide something like this:
18906 @image{images/service-graph,,5in,Typical service extension graph.}
18908 @cindex system service
18909 At the bottom, we see the @dfn{system service}, which produces the
18910 directory containing everything to run and boot the system, as returned
18911 by the @command{guix system build} command. @xref{Service Reference},
18912 to learn about the other service types shown here.
18913 @xref{system-extension-graph, the @command{guix system extension-graph}
18914 command}, for information on how to generate this representation for a
18915 particular operating system definition.
18917 @cindex service types
18918 Technically, developers can define @dfn{service types} to express these
18919 relations. There can be any number of services of a given type on the
18920 system---for instance, a system running two instances of the GNU secure
18921 shell server (lsh) has two instances of @var{lsh-service-type}, with
18922 different parameters.
18924 The following section describes the programming interface for service
18925 types and services.
18927 @node Service Types and Services
18928 @subsubsection Service Types and Services
18930 A @dfn{service type} is a node in the DAG described above. Let us start
18931 with a simple example, the service type for the Guix build daemon
18932 (@pxref{Invoking guix-daemon}):
18935 (define guix-service-type
18939 (list (service-extension shepherd-root-service-type guix-shepherd-service)
18940 (service-extension account-service-type guix-accounts)
18941 (service-extension activation-service-type guix-activation)))
18942 (default-value (guix-configuration))))
18946 It defines three things:
18950 A name, whose sole purpose is to make inspection and debugging easier.
18953 A list of @dfn{service extensions}, where each extension designates the
18954 target service type and a procedure that, given the parameters of the
18955 service, returns a list of objects to extend the service of that type.
18957 Every service type has at least one service extension. The only
18958 exception is the @dfn{boot service type}, which is the ultimate service.
18961 Optionally, a default value for instances of this type.
18964 In this example, @var{guix-service-type} extends three services:
18967 @item shepherd-root-service-type
18968 The @var{guix-shepherd-service} procedure defines how the Shepherd
18969 service is extended. Namely, it returns a @code{<shepherd-service>}
18970 object that defines how @command{guix-daemon} is started and stopped
18971 (@pxref{Shepherd Services}).
18973 @item account-service-type
18974 This extension for this service is computed by @var{guix-accounts},
18975 which returns a list of @code{user-group} and @code{user-account}
18976 objects representing the build user accounts (@pxref{Invoking
18979 @item activation-service-type
18980 Here @var{guix-activation} is a procedure that returns a gexp, which is
18981 a code snippet to run at ``activation time''---e.g., when the service is
18985 A service of this type is instantiated like this:
18988 (service guix-service-type
18989 (guix-configuration
18991 (use-substitutes? #f)))
18994 The second argument to the @code{service} form is a value representing
18995 the parameters of this specific service instance.
18996 @xref{guix-configuration-type, @code{guix-configuration}}, for
18997 information about the @code{guix-configuration} data type. When the
18998 value is omitted, the default value specified by
18999 @code{guix-service-type} is used:
19002 (service guix-service-type)
19005 @var{guix-service-type} is quite simple because it extends other
19006 services but is not extensible itself.
19008 @c @subsubsubsection Extensible Service Types
19010 The service type for an @emph{extensible} service looks like this:
19013 (define udev-service-type
19014 (service-type (name 'udev)
19016 (list (service-extension shepherd-root-service-type
19017 udev-shepherd-service)))
19019 (compose concatenate) ;concatenate the list of rules
19020 (extend (lambda (config rules)
19022 (($ <udev-configuration> udev initial-rules)
19023 (udev-configuration
19024 (udev udev) ;the udev package to use
19025 (rules (append initial-rules rules)))))))))
19028 This is the service type for the
19029 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
19030 management daemon}. Compared to the previous example, in addition to an
19031 extension of @var{shepherd-root-service-type}, we see two new fields:
19035 This is the procedure to @dfn{compose} the list of extensions to
19036 services of this type.
19038 Services can extend the udev service by passing it lists of rules; we
19039 compose those extensions simply by concatenating them.
19042 This procedure defines how the value of the service is @dfn{extended} with
19043 the composition of the extensions.
19045 Udev extensions are composed into a list of rules, but the udev service
19046 value is itself a @code{<udev-configuration>} record. So here, we
19047 extend that record by appending the list of rules it contains to the
19048 list of contributed rules.
19051 This is a string giving an overview of the service type. The string can
19052 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
19053 @command{guix system search} command searches these strings and displays
19054 them (@pxref{Invoking guix system}).
19057 There can be only one instance of an extensible service type such as
19058 @var{udev-service-type}. If there were more, the
19059 @code{service-extension} specifications would be ambiguous.
19061 Still here? The next section provides a reference of the programming
19062 interface for services.
19064 @node Service Reference
19065 @subsubsection Service Reference
19067 We have seen an overview of service types (@pxref{Service Types and
19068 Services}). This section provides a reference on how to manipulate
19069 services and service types. This interface is provided by the
19070 @code{(gnu services)} module.
19072 @deffn {Scheme Procedure} service @var{type} [@var{value}]
19073 Return a new service of @var{type}, a @code{<service-type>} object (see
19074 below.) @var{value} can be any object; it represents the parameters of
19075 this particular service instance.
19077 When @var{value} is omitted, the default value specified by @var{type}
19078 is used; if @var{type} does not specify a default value, an error is
19081 For instance, this:
19084 (service openssh-service-type)
19088 is equivalent to this:
19091 (service openssh-service-type
19092 (openssh-configuration))
19095 In both cases the result is an instance of @code{openssh-service-type}
19096 with the default configuration.
19099 @deffn {Scheme Procedure} service? @var{obj}
19100 Return true if @var{obj} is a service.
19103 @deffn {Scheme Procedure} service-kind @var{service}
19104 Return the type of @var{service}---i.e., a @code{<service-type>} object.
19107 @deffn {Scheme Procedure} service-value @var{service}
19108 Return the value associated with @var{service}. It represents its
19112 Here is an example of how a service is created and manipulated:
19116 (service nginx-service-type
19117 (nginx-configuration
19119 (log-directory log-directory)
19120 (run-directory run-directory)
19121 (file config-file))))
19126 (eq? (service-kind s) nginx-service-type)
19130 The @code{modify-services} form provides a handy way to change the
19131 parameters of some of the services of a list such as
19132 @var{%base-services} (@pxref{Base Services, @code{%base-services}}). It
19133 evaluates to a list of services. Of course, you could always use
19134 standard list combinators such as @code{map} and @code{fold} to do that
19135 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
19136 @code{modify-services} simply provides a more concise form for this
19139 @deffn {Scheme Syntax} modify-services @var{services} @
19140 (@var{type} @var{variable} => @var{body}) @dots{}
19142 Modify the services listed in @var{services} according to the given
19143 clauses. Each clause has the form:
19146 (@var{type} @var{variable} => @var{body})
19149 where @var{type} is a service type---e.g.,
19150 @code{guix-service-type}---and @var{variable} is an identifier that is
19151 bound within the @var{body} to the service parameters---e.g., a
19152 @code{guix-configuration} instance---of the original service of that
19155 The @var{body} should evaluate to the new service parameters, which will
19156 be used to configure the new service. This new service will replace the
19157 original in the resulting list. Because a service's service parameters
19158 are created using @code{define-record-type*}, you can write a succinct
19159 @var{body} that evaluates to the new service parameters by using the
19160 @code{inherit} feature that @code{define-record-type*} provides.
19162 @xref{Using the Configuration System}, for example usage.
19166 Next comes the programming interface for service types. This is
19167 something you want to know when writing new service definitions, but not
19168 necessarily when simply looking for ways to customize your
19169 @code{operating-system} declaration.
19171 @deftp {Data Type} service-type
19172 @cindex service type
19173 This is the representation of a @dfn{service type} (@pxref{Service Types
19178 This is a symbol, used only to simplify inspection and debugging.
19180 @item @code{extensions}
19181 A non-empty list of @code{<service-extension>} objects (see below).
19183 @item @code{compose} (default: @code{#f})
19184 If this is @code{#f}, then the service type denotes services that cannot
19185 be extended---i.e., services that do not receive ``values'' from other
19188 Otherwise, it must be a one-argument procedure. The procedure is called
19189 by @code{fold-services} and is passed a list of values collected from
19190 extensions. It must return a value that is a valid parameter value for
19191 the service instance.
19193 @item @code{extend} (default: @code{#f})
19194 If this is @code{#f}, services of this type cannot be extended.
19196 Otherwise, it must be a two-argument procedure: @code{fold-services}
19197 calls it, passing it the initial value of the service as the first argument
19198 and the result of applying @code{compose} to the extension values as the
19202 @xref{Service Types and Services}, for examples.
19205 @deffn {Scheme Procedure} service-extension @var{target-type} @
19207 Return a new extension for services of type @var{target-type}.
19208 @var{compute} must be a one-argument procedure: @code{fold-services}
19209 calls it, passing it the value associated with the service that provides
19210 the extension; it must return a valid value for the target service.
19213 @deffn {Scheme Procedure} service-extension? @var{obj}
19214 Return true if @var{obj} is a service extension.
19217 Occasionally, you might want to simply extend an existing service. This
19218 involves creating a new service type and specifying the extension of
19219 interest, which can be verbose; the @code{simple-service} procedure
19220 provides a shorthand for this.
19222 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
19223 Return a service that extends @var{target} with @var{value}. This works
19224 by creating a singleton service type @var{name}, of which the returned
19225 service is an instance.
19227 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
19231 (simple-service 'my-mcron-job mcron-service-type
19232 #~(job '(next-hour (3)) "guix gc -F 2G"))
19236 At the core of the service abstraction lies the @code{fold-services}
19237 procedure, which is responsible for ``compiling'' a list of services
19238 down to a single directory that contains everything needed to boot and
19239 run the system---the directory shown by the @command{guix system build}
19240 command (@pxref{Invoking guix system}). In essence, it propagates
19241 service extensions down the service graph, updating each node parameters
19242 on the way, until it reaches the root node.
19244 @deffn {Scheme Procedure} fold-services @var{services} @
19245 [#:target-type @var{system-service-type}]
19246 Fold @var{services} by propagating their extensions down to the root of
19247 type @var{target-type}; return the root service adjusted accordingly.
19250 Lastly, the @code{(gnu services)} module also defines several essential
19251 service types, some of which are listed below.
19253 @defvr {Scheme Variable} system-service-type
19254 This is the root of the service graph. It produces the system directory
19255 as returned by the @command{guix system build} command.
19258 @defvr {Scheme Variable} boot-service-type
19259 The type of the ``boot service'', which produces the @dfn{boot script}.
19260 The boot script is what the initial RAM disk runs when booting.
19263 @defvr {Scheme Variable} etc-service-type
19264 The type of the @file{/etc} service. This service is used to create
19265 files under @file{/etc} and can be extended by
19266 passing it name/file tuples such as:
19269 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
19272 In this example, the effect would be to add an @file{/etc/issue} file
19273 pointing to the given file.
19276 @defvr {Scheme Variable} setuid-program-service-type
19277 Type for the ``setuid-program service''. This service collects lists of
19278 executable file names, passed as gexps, and adds them to the set of
19279 setuid-root programs on the system (@pxref{Setuid Programs}).
19282 @defvr {Scheme Variable} profile-service-type
19283 Type of the service that populates the @dfn{system profile}---i.e., the
19284 programs under @file{/run/current-system/profile}. Other services can
19285 extend it by passing it lists of packages to add to the system profile.
19289 @node Shepherd Services
19290 @subsubsection Shepherd Services
19292 @cindex shepherd services
19294 @cindex init system
19295 The @code{(gnu services shepherd)} module provides a way to define
19296 services managed by the GNU@tie{}Shepherd, which is the GuixSD
19297 initialization system---the first process that is started when the
19298 system boots, also known as PID@tie{}1
19299 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
19301 Services in the Shepherd can depend on each other. For instance, the
19302 SSH daemon may need to be started after the syslog daemon has been
19303 started, which in turn can only happen once all the file systems have
19304 been mounted. The simple operating system defined earlier (@pxref{Using
19305 the Configuration System}) results in a service graph like this:
19307 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
19309 You can actually generate such a graph for any operating system
19310 definition using the @command{guix system shepherd-graph} command
19311 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
19313 The @var{%shepherd-root-service} is a service object representing
19314 PID@tie{}1, of type @var{shepherd-root-service-type}; it can be extended
19315 by passing it lists of @code{<shepherd-service>} objects.
19317 @deftp {Data Type} shepherd-service
19318 The data type representing a service managed by the Shepherd.
19321 @item @code{provision}
19322 This is a list of symbols denoting what the service provides.
19324 These are the names that may be passed to @command{herd start},
19325 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
19326 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
19327 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
19329 @item @code{requirements} (default: @code{'()})
19330 List of symbols denoting the Shepherd services this one depends on.
19332 @item @code{respawn?} (default: @code{#t})
19333 Whether to restart the service when it stops, for instance when the
19334 underlying process dies.
19337 @itemx @code{stop} (default: @code{#~(const #f)})
19338 The @code{start} and @code{stop} fields refer to the Shepherd's
19339 facilities to start and stop processes (@pxref{Service De- and
19340 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
19341 G-expressions that get expanded in the Shepherd configuration file
19342 (@pxref{G-Expressions}).
19344 @item @code{documentation}
19345 A documentation string, as shown when running:
19348 herd doc @var{service-name}
19351 where @var{service-name} is one of the symbols in @var{provision}
19352 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
19354 @item @code{modules} (default: @var{%default-modules})
19355 This is the list of modules that must be in scope when @code{start} and
19356 @code{stop} are evaluated.
19361 @defvr {Scheme Variable} shepherd-root-service-type
19362 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
19364 This is the service type that extensions target when they want to create
19365 shepherd services (@pxref{Service Types and Services}, for an example).
19366 Each extension must pass a list of @code{<shepherd-service>}.
19369 @defvr {Scheme Variable} %shepherd-root-service
19370 This service represents PID@tie{}1.
19374 @node Documentation
19375 @section Documentation
19377 @cindex documentation, searching for
19378 @cindex searching for documentation
19379 @cindex Info, documentation format
19381 @cindex manual pages
19382 In most cases packages installed with Guix come with documentation.
19383 There are two main documentation formats: ``Info'', a browseable
19384 hypertext format used for GNU software, and ``manual pages'' (or ``man
19385 pages''), the linear documentation format traditionally found on Unix.
19386 Info manuals are accessed with the @command{info} command or with Emacs,
19387 and man pages are accessed using @command{man}.
19389 You can look for documentation of software installed on your system by
19390 keyword. For example, the following command searches for information
19391 about ``TLS'' in Info manuals:
19395 "(emacs)Network Security" -- STARTTLS
19396 "(emacs)Network Security" -- TLS
19397 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
19398 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
19403 The command below searches for the same keyword in man pages:
19407 SSL (7) - OpenSSL SSL/TLS library
19408 certtool (1) - GnuTLS certificate tool
19412 These searches are purely local to your computer so you have the
19413 guarantee that documentation you find corresponds to what you have
19414 actually installed, you can access it off-line, and your privacy is
19417 Once you have these results, you can view the relevant documentation by
19421 $ info "(gnutls)Core TLS API"
19431 Info manuals contain sections and indices as well as hyperlinks like
19432 those found in Web pages. The @command{info} reader (@pxref{Top, Info
19433 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
19434 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
19435 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
19436 Introduction}, for an introduction to Info navigation.
19438 @node Installing Debugging Files
19439 @section Installing Debugging Files
19441 @cindex debugging files
19442 Program binaries, as produced by the GCC compilers for instance, are
19443 typically written in the ELF format, with a section containing
19444 @dfn{debugging information}. Debugging information is what allows the
19445 debugger, GDB, to map binary code to source code; it is required to
19446 debug a compiled program in good conditions.
19448 The problem with debugging information is that is takes up a fair amount
19449 of disk space. For example, debugging information for the GNU C Library
19450 weighs in at more than 60 MiB. Thus, as a user, keeping all the
19451 debugging info of all the installed programs is usually not an option.
19452 Yet, space savings should not come at the cost of an impediment to
19453 debugging---especially in the GNU system, which should make it easier
19454 for users to exert their computing freedom (@pxref{GNU Distribution}).
19456 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
19457 mechanism that allows users to get the best of both worlds: debugging
19458 information can be stripped from the binaries and stored in separate
19459 files. GDB is then able to load debugging information from those files,
19460 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
19463 The GNU distribution takes advantage of this by storing debugging
19464 information in the @code{lib/debug} sub-directory of a separate package
19465 output unimaginatively called @code{debug} (@pxref{Packages with
19466 Multiple Outputs}). Users can choose to install the @code{debug} output
19467 of a package when they need it. For instance, the following command
19468 installs the debugging information for the GNU C Library and for GNU
19472 guix package -i glibc:debug guile:debug
19475 GDB must then be told to look for debug files in the user's profile, by
19476 setting the @code{debug-file-directory} variable (consider setting it
19477 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
19481 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
19484 From there on, GDB will pick up debugging information from the
19485 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
19487 In addition, you will most likely want GDB to be able to show the source
19488 code being debugged. To do that, you will have to unpack the source
19489 code of the package of interest (obtained with @code{guix build
19490 --source}, @pxref{Invoking guix build}), and to point GDB to that source
19491 directory using the @code{directory} command (@pxref{Source Path,
19492 @code{directory},, gdb, Debugging with GDB}).
19494 @c XXX: keep me up-to-date
19495 The @code{debug} output mechanism in Guix is implemented by the
19496 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
19497 opt-in---debugging information is available only for the packages
19498 with definitions explicitly declaring a @code{debug} output. This may be
19499 changed to opt-out in the future if our build farm servers can handle
19500 the load. To check whether a package has a @code{debug} output, use
19501 @command{guix package --list-available} (@pxref{Invoking guix package}).
19504 @node Security Updates
19505 @section Security Updates
19507 @cindex security updates
19508 @cindex security vulnerabilities
19509 Occasionally, important security vulnerabilities are discovered in software
19510 packages and must be patched. Guix developers try hard to keep track of
19511 known vulnerabilities and to apply fixes as soon as possible in the
19512 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
19513 containing only security updates.) The @command{guix lint} tool helps
19514 developers find out about vulnerable versions of software packages in the
19519 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
19520 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
19521 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
19525 @xref{Invoking guix lint}, for more information.
19528 As of version @value{VERSION}, the feature described below is considered
19532 Guix follows a functional
19533 package management discipline (@pxref{Introduction}), which implies
19534 that, when a package is changed, @emph{every package that depends on it}
19535 must be rebuilt. This can significantly slow down the deployment of
19536 fixes in core packages such as libc or Bash, since basically the whole
19537 distribution would need to be rebuilt. Using pre-built binaries helps
19538 (@pxref{Substitutes}), but deployment may still take more time than
19542 To address this, Guix implements @dfn{grafts}, a mechanism that allows
19543 for fast deployment of critical updates without the costs associated
19544 with a whole-distribution rebuild. The idea is to rebuild only the
19545 package that needs to be patched, and then to ``graft'' it onto packages
19546 explicitly installed by the user and that were previously referring to
19547 the original package. The cost of grafting is typically very low, and
19548 order of magnitudes lower than a full rebuild of the dependency chain.
19550 @cindex replacements of packages, for grafts
19551 For instance, suppose a security update needs to be applied to Bash.
19552 Guix developers will provide a package definition for the ``fixed''
19553 Bash, say @var{bash-fixed}, in the usual way (@pxref{Defining
19554 Packages}). Then, the original package definition is augmented with a
19555 @code{replacement} field pointing to the package containing the bug fix:
19562 (replacement bash-fixed)))
19565 From there on, any package depending directly or indirectly on Bash---as
19566 reported by @command{guix gc --requisites} (@pxref{Invoking guix
19567 gc})---that is installed is automatically ``rewritten'' to refer to
19568 @var{bash-fixed} instead of @var{bash}. This grafting process takes
19569 time proportional to the size of the package, usually less than a
19570 minute for an ``average'' package on a recent machine. Grafting is
19571 recursive: when an indirect dependency requires grafting, then grafting
19572 ``propagates'' up to the package that the user is installing.
19574 Currently, the length of the name and version of the graft and that of
19575 the package it replaces (@var{bash-fixed} and @var{bash} in the example
19576 above) must be equal. This restriction mostly comes from the fact that
19577 grafting works by patching files, including binary files, directly.
19578 Other restrictions may apply: for instance, when adding a graft to a
19579 package providing a shared library, the original shared library and its
19580 replacement must have the same @code{SONAME} and be binary-compatible.
19582 The @option{--no-grafts} command-line option allows you to forcefully
19583 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
19587 guix build bash --no-grafts
19591 returns the store file name of the original Bash, whereas:
19598 returns the store file name of the ``fixed'', replacement Bash. This
19599 allows you to distinguish between the two variants of Bash.
19601 To verify which Bash your whole profile refers to, you can run
19602 (@pxref{Invoking guix gc}):
19605 guix gc -R `readlink -f ~/.guix-profile` | grep bash
19609 @dots{} and compare the store file names that you get with those above.
19610 Likewise for a complete GuixSD system generation:
19613 guix gc -R `guix system build my-config.scm` | grep bash
19616 Lastly, to check which Bash running processes are using, you can use the
19617 @command{lsof} command:
19620 lsof | grep /gnu/store/.*bash
19624 @node Package Modules
19625 @section Package Modules
19627 From a programming viewpoint, the package definitions of the
19628 GNU distribution are provided by Guile modules in the @code{(gnu packages
19629 @dots{})} name space@footnote{Note that packages under the @code{(gnu
19630 packages @dots{})} module name space are not necessarily ``GNU
19631 packages''. This module naming scheme follows the usual Guile module
19632 naming convention: @code{gnu} means that these modules are distributed
19633 as part of the GNU system, and @code{packages} identifies modules that
19634 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
19635 Reference Manual}). For instance, the @code{(gnu packages emacs)}
19636 module exports a variable named @code{emacs}, which is bound to a
19637 @code{<package>} object (@pxref{Defining Packages}).
19639 The @code{(gnu packages @dots{})} module name space is
19640 automatically scanned for packages by the command-line tools. For
19641 instance, when running @code{guix package -i emacs}, all the @code{(gnu
19642 packages @dots{})} modules are scanned until one that exports a package
19643 object whose name is @code{emacs} is found. This package search
19644 facility is implemented in the @code{(gnu packages)} module.
19646 @cindex customization, of packages
19647 @cindex package module search path
19648 Users can store package definitions in modules with different
19649 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
19650 name and module name must match. For instance, the @code{(my-packages
19651 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
19652 relative to the load path specified with @option{--load-path} or
19653 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
19654 guile, GNU Guile Reference Manual}, for details.}. These package definitions
19655 will not be visible by default. Users can invoke commands such as
19656 @command{guix package} and @command{guix build} with the
19657 @code{-e} option so that they know where to find the package. Better
19658 yet, they can use the
19659 @code{-L} option of these commands to make those modules visible
19660 (@pxref{Invoking guix build, @code{--load-path}}), or define the
19661 @code{GUIX_PACKAGE_PATH} environment variable. This environment
19662 variable makes it easy to extend or customize the distribution and is
19663 honored by all the user interfaces.
19665 @defvr {Environment Variable} GUIX_PACKAGE_PATH
19666 This is a colon-separated list of directories to search for additional
19667 package modules. Directories listed in this variable take precedence
19668 over the own modules of the distribution.
19671 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
19672 each package is built based solely on other packages in the
19673 distribution. The root of this dependency graph is a small set of
19674 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
19675 bootstrap)} module. For more information on bootstrapping,
19676 @pxref{Bootstrapping}.
19678 @node Packaging Guidelines
19679 @section Packaging Guidelines
19681 @cindex packages, creating
19682 The GNU distribution is nascent and may well lack some of your favorite
19683 packages. This section describes how you can help make the distribution
19684 grow. @xref{Contributing}, for additional information on how you can
19687 Free software packages are usually distributed in the form of
19688 @dfn{source code tarballs}---typically @file{tar.gz} files that contain
19689 all the source files. Adding a package to the distribution means
19690 essentially two things: adding a @dfn{recipe} that describes how to
19691 build the package, including a list of other packages required to build
19692 it, and adding @dfn{package metadata} along with that recipe, such as a
19693 description and licensing information.
19695 In Guix all this information is embodied in @dfn{package definitions}.
19696 Package definitions provide a high-level view of the package. They are
19697 written using the syntax of the Scheme programming language; in fact,
19698 for each package we define a variable bound to the package definition,
19699 and export that variable from a module (@pxref{Package Modules}).
19700 However, in-depth Scheme knowledge is @emph{not} a prerequisite for
19701 creating packages. For more information on package definitions,
19702 @pxref{Defining Packages}.
19704 Once a package definition is in place, stored in a file in the Guix
19705 source tree, it can be tested using the @command{guix build} command
19706 (@pxref{Invoking guix build}). For example, assuming the new package is
19707 called @code{gnew}, you may run this command from the Guix build tree
19708 (@pxref{Running Guix Before It Is Installed}):
19711 ./pre-inst-env guix build gnew --keep-failed
19714 Using @code{--keep-failed} makes it easier to debug build failures since
19715 it provides access to the failed build tree. Another useful
19716 command-line option when debugging is @code{--log-file}, to access the
19719 If the package is unknown to the @command{guix} command, it may be that
19720 the source file contains a syntax error, or lacks a @code{define-public}
19721 clause to export the package variable. To figure it out, you may load
19722 the module from Guile to get more information about the actual error:
19725 ./pre-inst-env guile -c '(use-modules (gnu packages gnew))'
19728 Once your package builds correctly, please send us a patch
19729 (@pxref{Contributing}). Well, if you need help, we will be happy to
19730 help you too. Once the patch is committed in the Guix repository, the
19731 new package automatically gets built on the supported platforms by
19732 @url{http://hydra.gnu.org/jobset/gnu/master, our continuous integration
19735 @cindex substituter
19736 Users can obtain the new package definition simply by running
19737 @command{guix pull} (@pxref{Invoking guix pull}). When
19738 @code{hydra.gnu.org} is done building the package, installing the
19739 package automatically downloads binaries from there
19740 (@pxref{Substitutes}). The only place where human intervention is
19741 needed is to review and apply the patch.
19745 * Software Freedom:: What may go into the distribution.
19746 * Package Naming:: What's in a name?
19747 * Version Numbers:: When the name is not enough.
19748 * Synopses and Descriptions:: Helping users find the right package.
19749 * Python Modules:: A touch of British comedy.
19750 * Perl Modules:: Little pearls.
19751 * Java Packages:: Coffee break.
19752 * Fonts:: Fond of fonts.
19755 @node Software Freedom
19756 @subsection Software Freedom
19758 @c Adapted from http://www.gnu.org/philosophy/philosophy.html.
19759 @cindex free software
19760 The GNU operating system has been developed so that users can have
19761 freedom in their computing. GNU is @dfn{free software}, meaning that
19762 users have the @url{http://www.gnu.org/philosophy/free-sw.html,four
19763 essential freedoms}: to run the program, to study and change the program
19764 in source code form, to redistribute exact copies, and to distribute
19765 modified versions. Packages found in the GNU distribution provide only
19766 software that conveys these four freedoms.
19768 In addition, the GNU distribution follow the
19769 @url{http://www.gnu.org/distros/free-system-distribution-guidelines.html,free
19770 software distribution guidelines}. Among other things, these guidelines
19771 reject non-free firmware, recommendations of non-free software, and
19772 discuss ways to deal with trademarks and patents.
19774 Some otherwise free upstream package sources contain a small and optional
19775 subset that violates the above guidelines, for instance because this subset
19776 is itself non-free code. When that happens, the offending items are removed
19777 with appropriate patches or code snippets in the @code{origin} form of the
19778 package (@pxref{Defining Packages}). This way, @code{guix
19779 build --source} returns the ``freed'' source rather than the unmodified
19783 @node Package Naming
19784 @subsection Package Naming
19786 @cindex package name
19787 A package has actually two names associated with it:
19788 First, there is the name of the @emph{Scheme variable}, the one following
19789 @code{define-public}. By this name, the package can be made known in the
19790 Scheme code, for instance as input to another package. Second, there is
19791 the string in the @code{name} field of a package definition. This name
19792 is used by package management commands such as
19793 @command{guix package} and @command{guix build}.
19795 Both are usually the same and correspond to the lowercase conversion of
19796 the project name chosen upstream, with underscores replaced with
19797 hyphens. For instance, GNUnet is available as @code{gnunet}, and
19798 SDL_net as @code{sdl-net}.
19800 We do not add @code{lib} prefixes for library packages, unless these are
19801 already part of the official project name. But @pxref{Python
19802 Modules} and @ref{Perl Modules} for special rules concerning modules for
19803 the Python and Perl languages.
19805 Font package names are handled differently, @pxref{Fonts}.
19808 @node Version Numbers
19809 @subsection Version Numbers
19811 @cindex package version
19812 We usually package only the latest version of a given free software
19813 project. But sometimes, for instance for incompatible library versions,
19814 two (or more) versions of the same package are needed. These require
19815 different Scheme variable names. We use the name as defined
19816 in @ref{Package Naming}
19817 for the most recent version; previous versions use the same name, suffixed
19818 by @code{-} and the smallest prefix of the version number that may
19819 distinguish the two versions.
19821 The name inside the package definition is the same for all versions of a
19822 package and does not contain any version number.
19824 For instance, the versions 2.24.20 and 3.9.12 of GTK+ may be packaged as follows:
19827 (define-public gtk+
19832 (define-public gtk+-2
19835 (version "2.24.20")
19838 If we also wanted GTK+ 3.8.2, this would be packaged as
19840 (define-public gtk+-3.8
19847 @c See <https://lists.gnu.org/archive/html/guix-devel/2016-01/msg00425.html>,
19848 @c for a discussion of what follows.
19849 @cindex version number, for VCS snapshots
19850 Occasionally, we package snapshots of upstream's version control system
19851 (VCS) instead of formal releases. This should remain exceptional,
19852 because it is up to upstream developers to clarify what the stable
19853 release is. Yet, it is sometimes necessary. So, what should we put in
19854 the @code{version} field?
19856 Clearly, we need to make the commit identifier of the VCS snapshot
19857 visible in the version string, but we also need to make sure that the
19858 version string is monotonically increasing so that @command{guix package
19859 --upgrade} can determine which version is newer. Since commit
19860 identifiers, notably with Git, are not monotonically increasing, we add
19861 a revision number that we increase each time we upgrade to a newer
19862 snapshot. The resulting version string looks like this:
19867 | | `-- upstream commit ID
19869 | `--- Guix package revision
19871 latest upstream version
19874 It is a good idea to strip commit identifiers in the @code{version}
19875 field to, say, 7 digits. It avoids an aesthetic annoyance (assuming
19876 aesthetics have a role to play here) as well as problems related to OS
19877 limits such as the maximum shebang length (127 bytes for the Linux
19878 kernel.) It is best to use the full commit identifiers in
19879 @code{origin}s, though, to avoid ambiguities. A typical package
19880 definition may look like this:
19884 (let ((commit "c3f29bc928d5900971f65965feaae59e1272a3f7")
19885 (revision "1")) ;Guix package revision
19887 (version (string-append "0.9-" revision "."
19888 (string-take commit 7)))
19891 (uri (git-reference
19892 (url "git://example.org/my-package.git")
19894 (sha256 (base32 "1mbikn@dots{}"))
19895 (file-name (string-append "my-package-" version
19901 @node Synopses and Descriptions
19902 @subsection Synopses and Descriptions
19904 @cindex package description
19905 @cindex package synopsis
19906 As we have seen before, each package in GNU@tie{}Guix includes a
19907 synopsis and a description (@pxref{Defining Packages}). Synopses and
19908 descriptions are important: They are what @command{guix package
19909 --search} searches, and a crucial piece of information to help users
19910 determine whether a given package suits their needs. Consequently,
19911 packagers should pay attention to what goes into them.
19913 Synopses must start with a capital letter and must not end with a
19914 period. They must not start with ``a'' or ``the'', which usually does
19915 not bring anything; for instance, prefer ``File-frobbing tool'' over ``A
19916 tool that frobs files''. The synopsis should say what the package
19917 is---e.g., ``Core GNU utilities (file, text, shell)''---or what it is
19918 used for---e.g., the synopsis for GNU@tie{}grep is ``Print lines
19919 matching a pattern''.
19921 Keep in mind that the synopsis must be meaningful for a very wide
19922 audience. For example, ``Manipulate alignments in the SAM format''
19923 might make sense for a seasoned bioinformatics researcher, but might be
19924 fairly unhelpful or even misleading to a non-specialized audience. It
19925 is a good idea to come up with a synopsis that gives an idea of the
19926 application domain of the package. In this example, this might give
19927 something like ``Manipulate nucleotide sequence alignments'', which
19928 hopefully gives the user a better idea of whether this is what they are
19931 Descriptions should take between five and ten lines. Use full
19932 sentences, and avoid using acronyms without first introducing them.
19933 Please avoid marketing phrases such as ``world-leading'',
19934 ``industrial-strength'', and ``next-generation'', and avoid superlatives
19935 like ``the most advanced''---they are not helpful to users looking for a
19936 package and may even sound suspicious. Instead, try to be factual,
19937 mentioning use cases and features.
19939 @cindex Texinfo markup, in package descriptions
19940 Descriptions can include Texinfo markup, which is useful to introduce
19941 ornaments such as @code{@@code} or @code{@@dfn}, bullet lists, or
19942 hyperlinks (@pxref{Overview,,, texinfo, GNU Texinfo}). However you
19943 should be careful when using some characters for example @samp{@@} and
19944 curly braces which are the basic special characters in Texinfo
19945 (@pxref{Special Characters,,, texinfo, GNU Texinfo}). User interfaces
19946 such as @command{guix package --show} take care of rendering it
19949 Synopses and descriptions are translated by volunteers
19950 @uref{http://translationproject.org/domain/guix-packages.html, at the
19951 Translation Project} so that as many users as possible can read them in
19952 their native language. User interfaces search them and display them in
19953 the language specified by the current locale.
19955 To allow @command{xgettext} to extract them as translatable strings,
19956 synopses and descriptions @emph{must be literal strings}. This means
19957 that you cannot use @code{string-append} or @code{format} to construct
19963 (synopsis "This is translatable")
19964 (description (string-append "This is " "*not*" " translatable.")))
19967 Translation is a lot of work so, as a packager, please pay even more
19968 attention to your synopses and descriptions as every change may entail
19969 additional work for translators. In order to help them, it is possible
19970 to make recommendations or instructions visible to them by inserting
19971 special comments like this (@pxref{xgettext Invocation,,, gettext, GNU
19975 ;; TRANSLATORS: "X11 resize-and-rotate" should not be translated.
19976 (description "ARandR is designed to provide a simple visual front end
19977 for the X11 resize-and-rotate (RandR) extension. @dots{}")
19981 @node Python Modules
19982 @subsection Python Modules
19985 We currently package Python 2 and Python 3, under the Scheme variable names
19986 @code{python-2} and @code{python} as explained in @ref{Version Numbers}.
19987 To avoid confusion and naming clashes with other programming languages, it
19988 seems desirable that the name of a package for a Python module contains
19989 the word @code{python}.
19991 Some modules are compatible with only one version of Python, others with both.
19992 If the package Foo compiles only with Python 3, we name it
19993 @code{python-foo}; if it compiles only with Python 2, we name it
19994 @code{python2-foo}. If it is compatible with both versions, we create two
19995 packages with the corresponding names.
19997 If a project already contains the word @code{python}, we drop this;
19998 for instance, the module python-dateutil is packaged under the names
19999 @code{python-dateutil} and @code{python2-dateutil}. If the project name
20000 starts with @code{py} (e.g. @code{pytz}), we keep it and prefix it as
20003 @subsubsection Specifying Dependencies
20004 @cindex inputs, for Python packages
20006 Dependency information for Python packages is usually available in the
20007 package source tree, with varying degrees of accuracy: in the
20008 @file{setup.py} file, in @file{requirements.txt}, or in @file{tox.ini}.
20010 Your mission, when writing a recipe for a Python package, is to map
20011 these dependencies to the appropriate type of ``input'' (@pxref{package
20012 Reference, inputs}). Although the @code{pypi} importer normally does a
20013 good job (@pxref{Invoking guix import}), you may want to check the
20014 following check list to determine which dependency goes where.
20019 We currently package Python 2 with @code{setuptools} and @code{pip}
20020 installed like Python 3.4 has per default. Thus you don't need to
20021 specify either of these as an input. @command{guix lint} will warn you
20025 Python dependencies required at run time go into
20026 @code{propagated-inputs}. They are typically defined with the
20027 @code{install_requires} keyword in @file{setup.py}, or in the
20028 @file{requirements.txt} file.
20031 Python packages required only at build time---e.g., those listed with
20032 the @code{setup_requires} keyword in @file{setup.py}---or only for
20033 testing---e.g., those in @code{tests_require}---go into
20034 @code{native-inputs}. The rationale is that (1) they do not need to be
20035 propagated because they are not needed at run time, and (2) in a
20036 cross-compilation context, it's the ``native'' input that we'd want.
20038 Examples are the @code{pytest}, @code{mock}, and @code{nose} test
20039 frameworks. Of course if any of these packages is also required at
20040 run-time, it needs to go to @code{propagated-inputs}.
20043 Anything that does not fall in the previous categories goes to
20044 @code{inputs}, for example programs or C libraries required for building
20045 Python packages containing C extensions.
20048 If a Python package has optional dependencies (@code{extras_require}),
20049 it is up to you to decide whether to add them or not, based on their
20050 usefulness/overhead ratio (@pxref{Submitting Patches, @command{guix
20057 @subsection Perl Modules
20060 Perl programs standing for themselves are named as any other package,
20061 using the lowercase upstream name.
20062 For Perl packages containing a single class, we use the lowercase class name,
20063 replace all occurrences of @code{::} by dashes and prepend the prefix
20065 So the class @code{XML::Parser} becomes @code{perl-xml-parser}.
20066 Modules containing several classes keep their lowercase upstream name and
20067 are also prepended by @code{perl-}. Such modules tend to have the word
20068 @code{perl} somewhere in their name, which gets dropped in favor of the
20069 prefix. For instance, @code{libwww-perl} becomes @code{perl-libwww}.
20072 @node Java Packages
20073 @subsection Java Packages
20076 Java programs standing for themselves are named as any other package,
20077 using the lowercase upstream name.
20079 To avoid confusion and naming clashes with other programming languages,
20080 it is desirable that the name of a package for a Java package is
20081 prefixed with @code{java-}. If a project already contains the word
20082 @code{java}, we drop this; for instance, the package @code{ngsjava} is
20083 packaged under the name @code{java-ngs}.
20085 For Java packages containing a single class or a small class hierarchy,
20086 we use the lowercase class name, replace all occurrences of @code{.} by
20087 dashes and prepend the prefix @code{java-}. So the class
20088 @code{apache.commons.cli} becomes package
20089 @code{java-apache-commons-cli}.
20096 For fonts that are in general not installed by a user for typesetting
20097 purposes, or that are distributed as part of a larger software package,
20098 we rely on the general packaging rules for software; for instance, this
20099 applies to the fonts delivered as part of the X.Org system or fonts that
20100 are part of TeX Live.
20102 To make it easier for a user to search for fonts, names for other packages
20103 containing only fonts are constructed as follows, independently of the
20104 upstream package name.
20106 The name of a package containing only one font family starts with
20107 @code{font-}; it is followed by the foundry name and a dash @code{-}
20108 if the foundry is known, and the font family name, in which spaces are
20109 replaced by dashes (and as usual, all upper case letters are transformed
20111 For example, the Gentium font family by SIL is packaged under the name
20112 @code{font-sil-gentium}.
20114 For a package containing several font families, the name of the collection
20115 is used in the place of the font family name.
20116 For instance, the Liberation fonts consist of three families,
20117 Liberation Sans, Liberation Serif and Liberation Mono.
20118 These could be packaged separately under the names
20119 @code{font-liberation-sans} and so on; but as they are distributed together
20120 under a common name, we prefer to package them together as
20121 @code{font-liberation}.
20123 In the case where several formats of the same font family or font collection
20124 are packaged separately, a short form of the format, prepended by a dash,
20125 is added to the package name. We use @code{-ttf} for TrueType fonts,
20126 @code{-otf} for OpenType fonts and @code{-type1} for PostScript Type 1
20131 @node Bootstrapping
20132 @section Bootstrapping
20134 @c Adapted from the ELS 2013 paper.
20136 @cindex bootstrapping
20138 Bootstrapping in our context refers to how the distribution gets built
20139 ``from nothing''. Remember that the build environment of a derivation
20140 contains nothing but its declared inputs (@pxref{Introduction}). So
20141 there's an obvious chicken-and-egg problem: how does the first package
20142 get built? How does the first compiler get compiled? Note that this is
20143 a question of interest only to the curious hacker, not to the regular
20144 user, so you can shamelessly skip this section if you consider yourself
20145 a ``regular user''.
20147 @cindex bootstrap binaries
20148 The GNU system is primarily made of C code, with libc at its core. The
20149 GNU build system itself assumes the availability of a Bourne shell and
20150 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
20151 `grep'. Furthermore, build programs---programs that run
20152 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
20153 (@pxref{Derivations}). Consequently, to be able to build anything at
20154 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
20155 Binutils, libc, and the other packages mentioned above---the
20156 @dfn{bootstrap binaries}.
20158 These bootstrap binaries are ``taken for granted'', though we can also
20159 re-create them if needed (more on that later).
20161 @unnumberedsubsec Preparing to Use the Bootstrap Binaries
20163 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
20164 @c large image, it's hard to scroll. Oh well.
20165 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
20167 The figure above shows the very beginning of the dependency graph of the
20168 distribution, corresponding to the package definitions of the @code{(gnu
20169 packages bootstrap)} module. A similar figure can be generated with
20170 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
20173 guix graph -t derivation \
20174 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
20178 At this level of detail, things are
20179 slightly complex. First, Guile itself consists of an ELF executable,
20180 along with many source and compiled Scheme files that are dynamically
20181 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
20182 tarball shown in this graph. This tarball is part of Guix's ``source''
20183 distribution, and gets inserted into the store with @code{add-to-store}
20184 (@pxref{The Store}).
20186 But how do we write a derivation that unpacks this tarball and adds it
20187 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
20188 derivation---the first one that gets built---uses @code{bash} as its
20189 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
20190 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
20191 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
20192 the Guix source distribution, whose sole purpose is to allow the Guile
20193 tarball to be unpacked.
20195 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
20196 Guile that can be used to run subsequent build programs. Its first task
20197 is to download tarballs containing the other pre-built binaries---this
20198 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
20199 @code{ftp-client.scm} are used for this purpose. The
20200 @code{module-import.drv} derivations import those modules in a directory
20201 in the store, using the original layout. The
20202 @code{module-import-compiled.drv} derivations compile those modules, and
20203 write them in an output directory with the right layout. This
20204 corresponds to the @code{#:modules} argument of
20205 @code{build-expression->derivation} (@pxref{Derivations}).
20207 Finally, the various tarballs are unpacked by the
20208 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
20209 etc., at which point we have a working C tool chain.
20212 @unnumberedsubsec Building the Build Tools
20214 Bootstrapping is complete when we have a full tool chain that does not
20215 depend on the pre-built bootstrap tools discussed above. This
20216 no-dependency requirement is verified by checking whether the files of
20217 the final tool chain contain references to the @file{/gnu/store}
20218 directories of the bootstrap inputs. The process that leads to this
20219 ``final'' tool chain is described by the package definitions found in
20220 the @code{(gnu packages commencement)} module.
20222 The @command{guix graph} command allows us to ``zoom out'' compared to
20223 the graph above, by looking at the level of package objects instead of
20224 individual derivations---remember that a package may translate to
20225 several derivations, typically one derivation to download its source,
20226 one to build the Guile modules it needs, and one to actually build the
20227 package from source. The command:
20230 guix graph -t bag \
20231 -e '(@@@@ (gnu packages commencement)
20232 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
20236 produces the dependency graph leading to the ``final'' C
20237 library@footnote{You may notice the @code{glibc-intermediate} label,
20238 suggesting that it is not @emph{quite} final, but as a good
20239 approximation, we will consider it final.}, depicted below.
20241 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
20243 @c See <http://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
20244 The first tool that gets built with the bootstrap binaries is
20245 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
20246 for all the following packages. From there Findutils and Diffutils get
20249 Then come the first-stage Binutils and GCC, built as pseudo cross
20250 tools---i.e., with @code{--target} equal to @code{--host}. They are
20251 used to build libc. Thanks to this cross-build trick, this libc is
20252 guaranteed not to hold any reference to the initial tool chain.
20254 From there the final Binutils and GCC (not shown above) are built.
20256 from the final Binutils, and links programs against the just-built libc.
20257 This tool chain is used to build the other packages used by Guix and by
20258 the GNU Build System: Guile, Bash, Coreutils, etc.
20260 And voilà! At this point we have the complete set of build tools that
20261 the GNU Build System expects. These are in the @code{%final-inputs}
20262 variable of the @code{(gnu packages commencement)} module, and are
20263 implicitly used by any package that uses @code{gnu-build-system}
20264 (@pxref{Build Systems, @code{gnu-build-system}}).
20267 @unnumberedsubsec Building the Bootstrap Binaries
20269 @cindex bootstrap binaries
20270 Because the final tool chain does not depend on the bootstrap binaries,
20271 those rarely need to be updated. Nevertheless, it is useful to have an
20272 automated way to produce them, should an update occur, and this is what
20273 the @code{(gnu packages make-bootstrap)} module provides.
20275 The following command builds the tarballs containing the bootstrap
20276 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
20277 of Coreutils and other basic command-line tools):
20280 guix build bootstrap-tarballs
20283 The generated tarballs are those that should be referred to in the
20284 @code{(gnu packages bootstrap)} module mentioned at the beginning of
20287 Still here? Then perhaps by now you've started to wonder: when do we
20288 reach a fixed point? That is an interesting question! The answer is
20289 unknown, but if you would like to investigate further (and have
20290 significant computational and storage resources to do so), then let us
20294 @section Porting to a New Platform
20296 As discussed above, the GNU distribution is self-contained, and
20297 self-containment is achieved by relying on pre-built ``bootstrap
20298 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
20299 operating system kernel, CPU architecture, and application binary
20300 interface (ABI). Thus, to port the distribution to a platform that is
20301 not yet supported, one must build those bootstrap binaries, and update
20302 the @code{(gnu packages bootstrap)} module to use them on that platform.
20304 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
20305 When everything goes well, and assuming the GNU tool chain supports the
20306 target platform, this can be as simple as running a command like this
20310 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
20313 For this to work, the @code{glibc-dynamic-linker} procedure in
20314 @code{(gnu packages bootstrap)} must be augmented to return the right
20315 file name for libc's dynamic linker on that platform; likewise,
20316 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
20317 taught about the new platform.
20319 Once these are built, the @code{(gnu packages bootstrap)} module needs
20320 to be updated to refer to these binaries on the target platform. That
20321 is, the hashes and URLs of the bootstrap tarballs for the new platform
20322 must be added alongside those of the currently supported platforms. The
20323 bootstrap Guile tarball is treated specially: it is expected to be
20324 available locally, and @file{gnu/local.mk} has rules do download it for
20325 the supported architectures; a rule for the new platform must be added
20328 In practice, there may be some complications. First, it may be that the
20329 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
20330 above) is not recognized by all the GNU tools. Typically, glibc
20331 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
20332 configure flag (see @code{gcc.scm} for examples of how to handle this).
20333 Second, some of the required packages could fail to build for that
20334 platform. Lastly, the generated binaries could be broken for some
20337 @c *********************************************************************
20338 @include contributing.texi
20340 @c *********************************************************************
20341 @node Acknowledgments
20342 @chapter Acknowledgments
20344 Guix is based on the @uref{http://nixos.org/nix/, Nix package manager},
20345 which was designed and
20346 implemented by Eelco Dolstra, with contributions from other people (see
20347 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
20348 management, and promoted unprecedented features, such as transactional
20349 package upgrades and rollbacks, per-user profiles, and referentially
20350 transparent build processes. Without this work, Guix would not exist.
20352 The Nix-based software distributions, Nixpkgs and NixOS, have also been
20353 an inspiration for Guix.
20355 GNU@tie{}Guix itself is a collective work with contributions from a
20356 number of people. See the @file{AUTHORS} file in Guix for more
20357 information on these fine people. The @file{THANKS} file lists people
20358 who have helped by reporting bugs, taking care of the infrastructure,
20359 providing artwork and themes, making suggestions, and more---thank you!
20362 @c *********************************************************************
20363 @node GNU Free Documentation License
20364 @appendix GNU Free Documentation License
20365 @cindex license, GNU Free Documentation License
20366 @include fdl-1.3.texi
20368 @c *********************************************************************
20369 @node Concept Index
20370 @unnumbered Concept Index
20373 @node Programming Index
20374 @unnumbered Programming Index
20375 @syncodeindex tp fn
20376 @syncodeindex vr fn
20381 @c Local Variables:
20382 @c ispell-local-dictionary: "american";