6 @documentencoding UTF-8
7 @settitle GNU Guix Reference Manual
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16 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018 Ludovic Courtès@*
17 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
18 Copyright @copyright{} 2013 Nikita Karetnikov@*
19 Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
20 Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
21 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
22 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
23 Copyright @copyright{} 2015, 2016, 2017 Leo Famulari@*
24 Copyright @copyright{} 2015, 2016, 2017, 2018 Ricardo Wurmus@*
25 Copyright @copyright{} 2016 Ben Woodcroft@*
26 Copyright @copyright{} 2016, 2017 Chris Marusich@*
27 Copyright @copyright{} 2016, 2017, 2018 Efraim Flashner@*
28 Copyright @copyright{} 2016 John Darrington@*
29 Copyright @copyright{} 2016, 2017 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, 2018 Clément Lassieur@*
34 Copyright @copyright{} 2017 Mathieu Othacehe@*
35 Copyright @copyright{} 2017 Federico Beffa@*
36 Copyright @copyright{} 2017 Carlo Zancanaro@*
37 Copyright @copyright{} 2017 Thomas Danckaert@*
38 Copyright @copyright{} 2017 humanitiesNerd@*
39 Copyright @copyright{} 2017 Christopher Allan Webber@*
40 Copyright @copyright{} 2017 Marius Bakke@*
41 Copyright @copyright{} 2017 Hartmut Goebel@*
42 Copyright @copyright{} 2017 Maxim Cournoyer@*
43 Copyright @copyright{} 2017, 2018 Tobias Geerinckx-Rice@*
44 Copyright @copyright{} 2017 George Clemmer@*
45 Copyright @copyright{} 2017 Andy Wingo@*
46 Copyright @copyright{} 2017, 2018 Arun Isaac@*
47 Copyright @copyright{} 2017 nee@*
48 Copyright @copyright{} 2018 Rutger Helling@*
49 Copyright @copyright{} 2018 Oleg Pykhalov@*
50 Copyright @copyright{} 2018 Mike Gerwitz
52 Permission is granted to copy, distribute and/or modify this document
53 under the terms of the GNU Free Documentation License, Version 1.3 or
54 any later version published by the Free Software Foundation; with no
55 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
56 copy of the license is included in the section entitled ``GNU Free
57 Documentation License''.
60 @dircategory System administration
62 * Guix: (guix). Manage installed software and system configuration.
63 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
64 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
65 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
66 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
69 @dircategory Software development
71 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
72 * guix build: (guix)Invoking guix build. Building packages.
73 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
77 @title GNU Guix Reference Manual
78 @subtitle Using the GNU Guix Functional Package Manager
79 @author The GNU Guix Developers
82 @vskip 0pt plus 1filll
83 Edition @value{EDITION} @*
91 @c *********************************************************************
95 This document describes GNU Guix version @value{VERSION}, a functional
96 package management tool written for the GNU system.
99 * Introduction:: What is Guix about?
100 * Installation:: Installing Guix.
101 * Package Management:: Package installation, upgrade, etc.
102 * Programming Interface:: Using Guix in Scheme.
103 * Utilities:: Package management commands.
104 * GNU Distribution:: Software for your friendly GNU system.
105 * Contributing:: Your help needed!
107 * Acknowledgments:: Thanks!
108 * GNU Free Documentation License:: The license of this manual.
109 * Concept Index:: Concepts.
110 * Programming Index:: Data types, functions, and variables.
113 --- The Detailed Node Listing ---
117 * Binary Installation:: Getting Guix running in no time!
118 * Requirements:: Software needed to build and run Guix.
119 * Running the Test Suite:: Testing Guix.
120 * Setting Up the Daemon:: Preparing the build daemon's environment.
121 * Invoking guix-daemon:: Running the build daemon.
122 * Application Setup:: Application-specific setup.
124 Setting Up the Daemon
126 * Build Environment Setup:: Preparing the isolated build environment.
127 * Daemon Offload Setup:: Offloading builds to remote machines.
128 * SELinux Support:: Using an SELinux policy for the daemon.
132 * Features:: How Guix will make your life brighter.
133 * Invoking guix package:: Package installation, removal, etc.
134 * Substitutes:: Downloading pre-built binaries.
135 * Packages with Multiple Outputs:: Single source package, multiple outputs.
136 * Invoking guix gc:: Running the garbage collector.
137 * Invoking guix pull:: Fetching the latest Guix and distribution.
138 * Invoking guix pack:: Creating software bundles.
139 * Invoking guix archive:: Exporting and importing store files.
143 * Official Substitute Server:: One particular source of substitutes.
144 * Substitute Server Authorization:: How to enable or disable substitutes.
145 * Substitute Authentication:: How Guix verifies substitutes.
146 * Proxy Settings:: How to get substitutes via proxy.
147 * Substitution Failure:: What happens when substitution fails.
148 * On Trusting Binaries:: How can you trust that binary blob?
150 Programming Interface
152 * Defining Packages:: Defining new packages.
153 * Build Systems:: Specifying how packages are built.
154 * The Store:: Manipulating the package store.
155 * Derivations:: Low-level interface to package derivations.
156 * The Store Monad:: Purely functional interface to the store.
157 * G-Expressions:: Manipulating build expressions.
161 * package Reference :: The package data type.
162 * origin Reference:: The origin data type.
166 * Invoking guix build:: Building packages from the command line.
167 * Invoking guix edit:: Editing package definitions.
168 * Invoking guix download:: Downloading a file and printing its hash.
169 * Invoking guix hash:: Computing the cryptographic hash of a file.
170 * Invoking guix import:: Importing package definitions.
171 * Invoking guix refresh:: Updating package definitions.
172 * Invoking guix lint:: Finding errors in package definitions.
173 * Invoking guix size:: Profiling disk usage.
174 * Invoking guix graph:: Visualizing the graph of packages.
175 * Invoking guix environment:: Setting up development environments.
176 * Invoking guix publish:: Sharing substitutes.
177 * Invoking guix challenge:: Challenging substitute servers.
178 * Invoking guix copy:: Copying to and from a remote store.
179 * Invoking guix container:: Process isolation.
180 * Invoking guix weather:: Assessing substitute availability.
182 Invoking @command{guix build}
184 * Common Build Options:: Build options for most commands.
185 * Package Transformation Options:: Creating variants of packages.
186 * Additional Build Options:: Options specific to 'guix build'.
187 * Debugging Build Failures:: Real life packaging experience.
191 * System Installation:: Installing the whole operating system.
192 * System Configuration:: Configuring the operating system.
193 * Documentation:: Browsing software user manuals.
194 * Installing Debugging Files:: Feeding the debugger.
195 * Security Updates:: Deploying security fixes quickly.
196 * Package Modules:: Packages from the programmer's viewpoint.
197 * Packaging Guidelines:: Growing the distribution.
198 * Bootstrapping:: GNU/Linux built from scratch.
199 * Porting:: Targeting another platform or kernel.
203 * Limitations:: What you can expect.
204 * Hardware Considerations:: Supported hardware.
205 * USB Stick and DVD Installation:: Preparing the installation medium.
206 * Preparing for Installation:: Networking, partitioning, etc.
207 * Proceeding with the Installation:: The real thing.
208 * Installing GuixSD in a VM:: GuixSD playground.
209 * Building the Installation Image:: How this comes to be.
213 * Using the Configuration System:: Customizing your GNU system.
214 * operating-system Reference:: Detail of operating-system declarations.
215 * File Systems:: Configuring file system mounts.
216 * Mapped Devices:: Block device extra processing.
217 * User Accounts:: Specifying user accounts.
218 * Locales:: Language and cultural convention settings.
219 * Services:: Specifying system services.
220 * Setuid Programs:: Programs running with root privileges.
221 * X.509 Certificates:: Authenticating HTTPS servers.
222 * Name Service Switch:: Configuring libc's name service switch.
223 * Initial RAM Disk:: Linux-Libre bootstrapping.
224 * Bootloader Configuration:: Configuring the boot loader.
225 * Invoking guix system:: Instantiating a system configuration.
226 * Running GuixSD in a VM:: How to run GuixSD in a virtual machine.
227 * Defining Services:: Adding new service definitions.
231 * Base Services:: Essential system services.
232 * Scheduled Job Execution:: The mcron service.
233 * Log Rotation:: The rottlog service.
234 * Networking Services:: Network setup, SSH daemon, etc.
235 * X Window:: Graphical display.
236 * Printing Services:: Local and remote printer support.
237 * Desktop Services:: D-Bus and desktop services.
238 * Database Services:: SQL databases, key-value stores, etc.
239 * Mail Services:: IMAP, POP3, SMTP, and all that.
240 * Messaging Services:: Messaging services.
241 * Telephony Services:: Telephony services.
242 * Monitoring Services:: Monitoring services.
243 * Kerberos Services:: Kerberos services.
244 * Web Services:: Web servers.
245 * Certificate Services:: TLS certificates via Let's Encrypt.
246 * DNS Services:: DNS daemons.
247 * VPN Services:: VPN daemons.
248 * Network File System:: NFS related services.
249 * Continuous Integration:: The Cuirass service.
250 * Power management Services:: The TLP tool.
251 * Audio Services:: The MPD.
252 * Virtualization Services:: Virtualization services.
253 * Version Control Services:: Providing remote access to Git repositories.
254 * Game Services:: Game servers.
255 * Miscellaneous Services:: Other services.
259 * Service Composition:: The model for composing services.
260 * Service Types and Services:: Types and services.
261 * Service Reference:: API reference.
262 * Shepherd Services:: A particular type of service.
266 * Software Freedom:: What may go into the distribution.
267 * Package Naming:: What's in a name?
268 * Version Numbers:: When the name is not enough.
269 * Synopses and Descriptions:: Helping users find the right package.
270 * Python Modules:: A touch of British comedy.
271 * Perl Modules:: Little pearls.
272 * Java Packages:: Coffee break.
273 * Fonts:: Fond of fonts.
277 * Building from Git:: The latest and greatest.
278 * Running Guix Before It Is Installed:: Hacker tricks.
279 * The Perfect Setup:: The right tools.
280 * Coding Style:: Hygiene of the contributor.
281 * Submitting Patches:: Share your work.
285 * Programming Paradigm:: How to compose your elements.
286 * Modules:: Where to store your code?
287 * Data Types and Pattern Matching:: Implementing data structures.
288 * Formatting Code:: Writing conventions.
293 @c *********************************************************************
295 @chapter Introduction
298 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
299 using the international phonetic alphabet (IPA).} is a package
300 management tool for the GNU system. Guix makes it easy for unprivileged
301 users to install, upgrade, or remove packages, to roll back to a
302 previous package set, to build packages from source, and generally
303 assists with the creation and maintenance of software environments.
305 @cindex user interfaces
306 Guix provides a command-line package management interface
307 (@pxref{Invoking guix package}), a set of command-line utilities
308 (@pxref{Utilities}), as well as Scheme programming interfaces
309 (@pxref{Programming Interface}).
311 Its @dfn{build daemon} is responsible for building packages on behalf of
312 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
313 binaries from authorized sources (@pxref{Substitutes}).
315 @cindex extensibility of the distribution
316 @cindex customization, of packages
317 Guix includes package definitions for many GNU and non-GNU packages, all
318 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
319 user's computing freedom}. It is @emph{extensible}: users can write
320 their own package definitions (@pxref{Defining Packages}) and make them
321 available as independent package modules (@pxref{Package Modules}). It
322 is also @emph{customizable}: users can @emph{derive} specialized package
323 definitions from existing ones, including from the command line
324 (@pxref{Package Transformation Options}).
326 @cindex Guix System Distribution
328 You can install GNU@tie{}Guix on top of an existing GNU/Linux system
329 where it complements the available tools without interference
330 (@pxref{Installation}), or you can use it as part of the standalone
331 @dfn{Guix System Distribution} or GuixSD (@pxref{GNU Distribution}).
332 With GNU@tie{}GuixSD, you @emph{declare} all aspects of the operating
333 system configuration and Guix takes care of instantiating the
334 configuration in a transactional, reproducible, and stateless fashion
335 (@pxref{System Configuration}).
337 @cindex functional package management
338 Under the hood, Guix implements the @dfn{functional package management}
339 discipline pioneered by Nix (@pxref{Acknowledgments}).
340 In Guix, the package build and installation process is seen
341 as a @emph{function}, in the mathematical sense. That function takes inputs,
342 such as build scripts, a compiler, and libraries, and
343 returns an installed package. As a pure function, its result depends
344 solely on its inputs---for instance, it cannot refer to software or
345 scripts that were not explicitly passed as inputs. A build function
346 always produces the same result when passed a given set of inputs. It
347 cannot alter the environment of the running system in
348 any way; for instance, it cannot create, modify, or delete files outside
349 of its build and installation directories. This is achieved by running
350 build processes in isolated environments (or @dfn{containers}), where only their
351 explicit inputs are visible.
354 The result of package build functions is @dfn{cached} in the file
355 system, in a special directory called @dfn{the store} (@pxref{The
356 Store}). Each package is installed in a directory of its own in the
357 store---by default under @file{/gnu/store}. The directory name contains
358 a hash of all the inputs used to build that package; thus, changing an
359 input yields a different directory name.
361 This approach is the foundation for the salient features of Guix: support
362 for transactional package upgrade and rollback, per-user installation, and
363 garbage collection of packages (@pxref{Features}).
366 @c *********************************************************************
368 @chapter Installation
370 @cindex installing Guix
371 GNU Guix is available for download from its website at
372 @url{http://www.gnu.org/software/guix/}. This section describes the
373 software requirements of Guix, as well as how to install it and get
376 Note that this section is concerned with the installation of the package
377 manager, which can be done on top of a running GNU/Linux system. If,
378 instead, you want to install the complete GNU operating system,
379 @pxref{System Installation}.
381 @cindex foreign distro
382 When installed on a running GNU/Linux system---thereafter called a
383 @dfn{foreign distro}---GNU@tie{}Guix complements the available tools
384 without interference. Its data lives exclusively in two directories,
385 usually @file{/gnu/store} and @file{/var/guix}; other files on your
386 system, such as @file{/etc}, are left untouched.
388 Once installed, Guix can be updated by running @command{guix pull}
389 (@pxref{Invoking guix pull}).
392 * Binary Installation:: Getting Guix running in no time!
393 * Requirements:: Software needed to build and run Guix.
394 * Running the Test Suite:: Testing Guix.
395 * Setting Up the Daemon:: Preparing the build daemon's environment.
396 * Invoking guix-daemon:: Running the build daemon.
397 * Application Setup:: Application-specific setup.
400 @node Binary Installation
401 @section Binary Installation
403 @cindex installing Guix from binaries
404 This section describes how to install Guix on an arbitrary system from a
405 self-contained tarball providing binaries for Guix and for all its
406 dependencies. This is often quicker than installing from source, which
407 is described in the next sections. The only requirement is to have
411 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
412 shell installer script}, which automates the download, installation, and
413 initial configuration of Guix. It should be run as the root user.
415 Installing goes along these lines:
419 @cindex downloading Guix binary
420 Download the binary tarball from
421 @indicateurl{ftp://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz},
422 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
423 already running the kernel Linux, and so on.
425 @c The following is somewhat duplicated in ``System Installation''.
426 Make sure to download the associated @file{.sig} file and to verify the
427 authenticity of the tarball against it, along these lines:
430 $ wget ftp://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
431 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
434 If that command fails because you do not have the required public key,
435 then run this command to import it:
438 $ gpg --keyserver pgp.mit.edu --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
442 and rerun the @code{gpg --verify} command.
443 @c end authentication part
446 Now, you need to become the @code{root} user. Depending on your distribution,
447 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
451 # tar --warning=no-timestamp -xf \
452 guix-binary-@value{VERSION}.@var{system}.tar.xz
453 # mv var/guix /var/ && mv gnu /
456 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
457 The latter contains a ready-to-use profile for @code{root} (see next
460 Do @emph{not} unpack the tarball on a working Guix system since that
461 would overwrite its own essential files.
463 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
464 not emit warnings about ``implausibly old time stamps'' (such
465 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
467 They stem from the fact that all the
468 files in the archive have their modification time set to zero (which
469 means January 1st, 1970.) This is done on purpose to make sure the
470 archive content is independent of its creation time, thus making it
474 Make @code{root}'s profile available under @file{~/.guix-profile}:
477 # ln -sf /var/guix/profiles/per-user/root/guix-profile \
481 Source @file{etc/profile} to augment @code{PATH} and other relevant
482 environment variables:
485 # GUIX_PROFILE=$HOME/.guix-profile ; \
486 source $GUIX_PROFILE/etc/profile
490 Create the group and user accounts for build users as explained below
491 (@pxref{Build Environment Setup}).
494 Run the daemon, and set it to automatically start on boot.
496 If your host distro uses the systemd init system, this can be achieved
499 @c Versions of systemd that supported symlinked service files are not
500 @c yet widely deployed, so we should suggest that users copy the service
503 @c See this thread for more information:
504 @c http://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
507 # cp ~root/.guix-profile/lib/systemd/system/guix-daemon.service \
509 # systemctl start guix-daemon && systemctl enable guix-daemon
512 If your host distro uses the Upstart init system:
515 # initctl reload-configuration
516 # cp ~root/.guix-profile/lib/upstart/system/guix-daemon.conf /etc/init/
520 Otherwise, you can still start the daemon manually with:
523 # ~root/.guix-profile/bin/guix-daemon --build-users-group=guixbuild
527 Make the @command{guix} command available to other users on the machine,
531 # mkdir -p /usr/local/bin
533 # ln -s /var/guix/profiles/per-user/root/guix-profile/bin/guix
536 It is also a good idea to make the Info version of this manual available
540 # mkdir -p /usr/local/share/info
541 # cd /usr/local/share/info
542 # for i in /var/guix/profiles/per-user/root/guix-profile/share/info/* ;
546 That way, assuming @file{/usr/local/share/info} is in the search path,
547 running @command{info guix} will open this manual (@pxref{Other Info
548 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
552 @cindex substitutes, authorization thereof
553 To use substitutes from @code{hydra.gnu.org} or one of its mirrors
554 (@pxref{Substitutes}), authorize them:
557 # guix archive --authorize < ~root/.guix-profile/share/guix/hydra.gnu.org.pub
561 Each user may need to perform a few additional steps to make their Guix
562 environment ready for use, @pxref{Application Setup}.
565 Voilà, the installation is complete!
567 You can confirm that Guix is working by installing a sample package into
571 # guix package -i hello
574 The @code{guix} package must remain available in @code{root}'s profile,
575 or it would become subject to garbage collection---in which case you
576 would find yourself badly handicapped by the lack of the @command{guix}
577 command. In other words, do not remove @code{guix} by running
578 @code{guix package -r guix}.
580 The binary installation tarball can be (re)produced and verified simply
581 by running the following command in the Guix source tree:
584 make guix-binary.@var{system}.tar.xz
588 ... which, in turn, runs:
591 guix pack -s @var{system} --localstatedir guix
594 @xref{Invoking guix pack}, for more info on this handy tool.
597 @section Requirements
599 This section lists requirements when building Guix from source. The
600 build procedure for Guix is the same as for other GNU software, and is
601 not covered here. Please see the files @file{README} and @file{INSTALL}
602 in the Guix source tree for additional details.
604 GNU Guix depends on the following packages:
607 @item @url{http://gnu.org/software/guile/, GNU Guile}, version 2.0.13 or
608 later, including 2.2.x;
609 @item @url{http://gnupg.org/, GNU libgcrypt};
611 @uref{http://gnutls.org/, GnuTLS}, specifically its Guile bindings
612 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
613 Guile,, gnutls-guile, GnuTLS-Guile});
615 @c FIXME: Specify a version number once a release has been made.
616 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
618 @item @url{http://zlib.net, zlib};
619 @item @url{http://www.gnu.org/software/make/, GNU Make}.
622 The following dependencies are optional:
627 @url{http://savannah.nongnu.org/projects/guile-json/, Guile-JSON} will
628 allow you to use the @command{guix import pypi} command (@pxref{Invoking
629 guix import}). It is of
630 interest primarily for developers and not for casual users.
633 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
634 Support for build offloading (@pxref{Daemon Offload Setup}) and
635 @command{guix copy} (@pxref{Invoking guix copy}) depends on
636 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
637 version 0.10.2 or later.
640 When @url{http://www.bzip.org, libbz2} is available,
641 @command{guix-daemon} can use it to compress build logs.
644 Unless @code{--disable-daemon} was passed to @command{configure}, the
645 following packages are also needed:
648 @item @url{http://sqlite.org, SQLite 3};
649 @item @url{http://gcc.gnu.org, GCC's g++}, with support for the
653 @cindex state directory
654 When configuring Guix on a system that already has a Guix installation,
655 be sure to specify the same state directory as the existing installation
656 using the @code{--localstatedir} option of the @command{configure}
657 script (@pxref{Directory Variables, @code{localstatedir},, standards,
658 GNU Coding Standards}). The @command{configure} script protects against
659 unintended misconfiguration of @var{localstatedir} so you do not
660 inadvertently corrupt your store (@pxref{The Store}).
662 @cindex Nix, compatibility
663 When a working installation of @url{http://nixos.org/nix/, the Nix package
664 manager} is available, you
665 can instead configure Guix with @code{--disable-daemon}. In that case,
666 Nix replaces the three dependencies above.
668 Guix is compatible with Nix, so it is possible to share the same store
669 between both. To do so, you must pass @command{configure} not only the
670 same @code{--with-store-dir} value, but also the same
671 @code{--localstatedir} value. The latter is essential because it
672 specifies where the database that stores metadata about the store is
673 located, among other things. The default values for Nix are
674 @code{--with-store-dir=/nix/store} and @code{--localstatedir=/nix/var}.
675 Note that @code{--disable-daemon} is not required if
676 your goal is to share the store with Nix.
678 @node Running the Test Suite
679 @section Running the Test Suite
682 After a successful @command{configure} and @code{make} run, it is a good
683 idea to run the test suite. It can help catch issues with the setup or
684 environment, or bugs in Guix itself---and really, reporting test
685 failures is a good way to help improve the software. To run the test
692 Test cases can run in parallel: you can use the @code{-j} option of
693 GNU@tie{}make to speed things up. The first run may take a few minutes
694 on a recent machine; subsequent runs will be faster because the store
695 that is created for test purposes will already have various things in
698 It is also possible to run a subset of the tests by defining the
699 @code{TESTS} makefile variable as in this example:
702 make check TESTS="tests/store.scm tests/cpio.scm"
705 By default, tests results are displayed at a file level. In order to
706 see the details of every individual test cases, it is possible to define
707 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
710 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
713 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
714 @file{test-suite.log} file. Please specify the Guix version being used
715 as well as version numbers of the dependencies (@pxref{Requirements}) in
718 Guix also comes with a whole-system test suite that tests complete
719 GuixSD operating system instances. It can only run on systems where
720 Guix is already installed, using:
727 or, again, by defining @code{TESTS} to select a subset of tests to run:
730 make check-system TESTS="basic mcron"
733 These system tests are defined in the @code{(gnu tests @dots{})}
734 modules. They work by running the operating systems under test with
735 lightweight instrumentation in a virtual machine (VM). They can be
736 computationally intensive or rather cheap, depending on whether
737 substitutes are available for their dependencies (@pxref{Substitutes}).
738 Some of them require a lot of storage space to hold VM images.
740 Again in case of test failures, please send @email{bug-guix@@gnu.org}
743 @node Setting Up the Daemon
744 @section Setting Up the Daemon
747 Operations such as building a package or running the garbage collector
748 are all performed by a specialized process, the @dfn{build daemon}, on
749 behalf of clients. Only the daemon may access the store and its
750 associated database. Thus, any operation that manipulates the store
751 goes through the daemon. For instance, command-line tools such as
752 @command{guix package} and @command{guix build} communicate with the
753 daemon (@i{via} remote procedure calls) to instruct it what to do.
755 The following sections explain how to prepare the build daemon's
756 environment. See also @ref{Substitutes}, for information on how to allow
757 the daemon to download pre-built binaries.
760 * Build Environment Setup:: Preparing the isolated build environment.
761 * Daemon Offload Setup:: Offloading builds to remote machines.
762 * SELinux Support:: Using an SELinux policy for the daemon.
765 @node Build Environment Setup
766 @subsection Build Environment Setup
768 @cindex build environment
769 In a standard multi-user setup, Guix and its daemon---the
770 @command{guix-daemon} program---are installed by the system
771 administrator; @file{/gnu/store} is owned by @code{root} and
772 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
773 Guix tools to build packages or otherwise access the store, and the
774 daemon will do it on their behalf, ensuring that the store is kept in a
775 consistent state, and allowing built packages to be shared among users.
778 When @command{guix-daemon} runs as @code{root}, you may not want package
779 build processes themselves to run as @code{root} too, for obvious
780 security reasons. To avoid that, a special pool of @dfn{build users}
781 should be created for use by build processes started by the daemon.
782 These build users need not have a shell and a home directory: they will
783 just be used when the daemon drops @code{root} privileges in build
784 processes. Having several such users allows the daemon to launch
785 distinct build processes under separate UIDs, which guarantees that they
786 do not interfere with each other---an essential feature since builds are
787 regarded as pure functions (@pxref{Introduction}).
789 On a GNU/Linux system, a build user pool may be created like this (using
790 Bash syntax and the @code{shadow} commands):
792 @c See http://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
793 @c for why `-G' is needed.
795 # groupadd --system guixbuild
796 # for i in `seq -w 1 10`;
798 useradd -g guixbuild -G guixbuild \
799 -d /var/empty -s `which nologin` \
800 -c "Guix build user $i" --system \
806 The number of build users determines how many build jobs may run in
807 parallel, as specified by the @option{--max-jobs} option
808 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
809 @command{guix system vm} and related commands, you may need to add the
810 build users to the @code{kvm} group so they can access @file{/dev/kvm},
811 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
812 (@pxref{Invoking guix system}).
814 The @code{guix-daemon} program may then be run as @code{root} with the
815 following command@footnote{If your machine uses the systemd init system,
816 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
817 file in @file{/etc/systemd/system} will ensure that
818 @command{guix-daemon} is automatically started. Similarly, if your
819 machine uses the Upstart init system, drop the
820 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
821 file in @file{/etc/init}.}:
824 # guix-daemon --build-users-group=guixbuild
829 This way, the daemon starts build processes in a chroot, under one of
830 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
831 environment contains nothing but:
833 @c Keep this list in sync with libstore/build.cc! -----------------------
836 a minimal @code{/dev} directory, created mostly independently from the
837 host @code{/dev}@footnote{``Mostly'', because while the set of files
838 that appear in the chroot's @code{/dev} is fixed, most of these files
839 can only be created if the host has them.};
842 the @code{/proc} directory; it only shows the processes of the container
843 since a separate PID name space is used;
846 @file{/etc/passwd} with an entry for the current user and an entry for
850 @file{/etc/group} with an entry for the user's group;
853 @file{/etc/hosts} with an entry that maps @code{localhost} to
857 a writable @file{/tmp} directory.
860 You can influence the directory where the daemon stores build trees
861 @i{via} the @code{TMPDIR} environment variable. However, the build tree
862 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
863 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
864 This way, the value of @code{TMPDIR} does not leak inside build
865 environments, which avoids discrepancies in cases where build processes
866 capture the name of their build tree.
869 The daemon also honors the @code{http_proxy} environment variable for
870 HTTP downloads it performs, be it for fixed-output derivations
871 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
873 If you are installing Guix as an unprivileged user, it is still possible
874 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
875 However, build processes will not be isolated from one another, and not
876 from the rest of the system. Thus, build processes may interfere with
877 each other, and may access programs, libraries, and other files
878 available on the system---making it much harder to view them as
879 @emph{pure} functions.
882 @node Daemon Offload Setup
883 @subsection Using the Offload Facility
887 When desired, the build daemon can @dfn{offload} derivation builds to
888 other machines running Guix, using the @code{offload} @dfn{build
889 hook}@footnote{This feature is available only when
890 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
892 feature is enabled, a list of user-specified build machines is read from
893 @file{/etc/guix/machines.scm}; every time a build is requested, for
894 instance via @code{guix build}, the daemon attempts to offload it to one
895 of the machines that satisfy the constraints of the derivation, in
896 particular its system type---e.g., @file{x86_64-linux}. Missing
897 prerequisites for the build are copied over SSH to the target machine,
898 which then proceeds with the build; upon success the output(s) of the
899 build are copied back to the initial machine.
901 The @file{/etc/guix/machines.scm} file typically looks like this:
905 (name "eightysix.example.org")
906 (system "x86_64-linux")
907 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
909 (speed 2.)) ;incredibly fast!
912 (name "meeps.example.org")
913 (system "mips64el-linux")
914 (host-key "ssh-rsa AAAAB3Nza@dots{}")
917 (string-append (getenv "HOME")
918 "/.ssh/identity-for-guix"))))
922 In the example above we specify a list of two build machines, one for
923 the @code{x86_64} architecture and one for the @code{mips64el}
926 In fact, this file is---not surprisingly!---a Scheme file that is
927 evaluated when the @code{offload} hook is started. Its return value
928 must be a list of @code{build-machine} objects. While this example
929 shows a fixed list of build machines, one could imagine, say, using
930 DNS-SD to return a list of potential build machines discovered in the
931 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
932 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
935 @deftp {Data Type} build-machine
936 This data type represents build machines to which the daemon may offload
937 builds. The important fields are:
942 The host name of the remote machine.
945 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
948 The user account to use when connecting to the remote machine over SSH.
949 Note that the SSH key pair must @emph{not} be passphrase-protected, to
950 allow non-interactive logins.
953 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
954 This is used to authenticate the machine when we connect to it. It is a
955 long string that looks like this:
958 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
961 If the machine is running the OpenSSH daemon, @command{sshd}, the host
962 key can be found in a file such as
963 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
965 If the machine is running the SSH daemon of GNU@tie{}lsh,
966 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
967 similar file. It can be converted to the OpenSSH format using
968 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
971 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
972 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
977 A number of optional fields may be specified:
981 @item @code{port} (default: @code{22})
982 Port number of SSH server on the machine.
984 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
985 The SSH private key file to use when connecting to the machine, in
988 Note that the default value is the private key @emph{of the root
989 account}. Make sure it exists if you use the default.
991 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
992 @itemx @code{compression-level} (default: @code{3})
993 The SSH-level compression methods and compression level requested.
995 Note that offloading relies on SSH compression to reduce bandwidth usage
996 when transferring files to and from build machines.
998 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
999 File name of the Unix-domain socket @command{guix-daemon} is listening
1002 @item @code{parallel-builds} (default: @code{1})
1003 The number of builds that may run in parallel on the machine.
1005 @item @code{speed} (default: @code{1.0})
1006 A ``relative speed factor''. The offload scheduler will tend to prefer
1007 machines with a higher speed factor.
1009 @item @code{features} (default: @code{'()})
1010 A list of strings denoting specific features supported by the machine.
1011 An example is @code{"kvm"} for machines that have the KVM Linux modules
1012 and corresponding hardware support. Derivations can request features by
1013 name, and they will be scheduled on matching build machines.
1018 The @code{guile} command must be in the search path on the build
1019 machines. In addition, the Guix modules must be in
1020 @code{$GUILE_LOAD_PATH} on the build machine---you can check whether
1021 this is the case by running:
1024 ssh build-machine guile -c "'(use-modules (guix config))'"
1027 There is one last thing to do once @file{machines.scm} is in place. As
1028 explained above, when offloading, files are transferred back and forth
1029 between the machine stores. For this to work, you first need to
1030 generate a key pair on each machine to allow the daemon to export signed
1031 archives of files from the store (@pxref{Invoking guix archive}):
1034 # guix archive --generate-key
1038 Each build machine must authorize the key of the master machine so that
1039 it accepts store items it receives from the master:
1042 # guix archive --authorize < master-public-key.txt
1046 Likewise, the master machine must authorize the key of each build machine.
1048 All the fuss with keys is here to express pairwise mutual trust
1049 relations between the master and the build machines. Concretely, when
1050 the master receives files from a build machine (and @i{vice versa}), its
1051 build daemon can make sure they are genuine, have not been tampered
1052 with, and that they are signed by an authorized key.
1054 @cindex offload test
1055 To test whether your setup is operational, run this command on the
1062 This will attempt to connect to each of the build machines specified in
1063 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1064 available on each machine, attempt to export to the machine and import
1065 from it, and report any error in the process.
1067 If you want to test a different machine file, just specify it on the
1071 # guix offload test machines-qualif.scm
1074 Last, you can test the subset of the machines whose name matches a
1075 regular expression like this:
1078 # guix offload test machines.scm '\.gnu\.org$'
1081 @cindex offload status
1082 To display the current load of all build hosts, run this command on the
1086 # guix offload status
1090 @node SELinux Support
1091 @subsection SELinux Support
1093 @cindex SELinux, daemon policy
1094 @cindex mandatory access control, SELinux
1095 @cindex security, guix-daemon
1096 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1097 can be installed on a system where SELinux is enabled, in order to label
1098 Guix files and to specify the expected behavior of the daemon. Since
1099 GuixSD does not provide an SELinux base policy, the daemon policy cannot
1102 @subsubsection Installing the SELinux policy
1103 @cindex SELinux, policy installation
1104 To install the policy run this command as root:
1107 semodule -i etc/guix-daemon.cil
1110 Then relabel the file system with @code{restorecon} or by a different
1111 mechanism provided by your system.
1113 Once the policy is installed, the file system has been relabeled, and
1114 the daemon has been restarted, it should be running in the
1115 @code{guix_daemon_t} context. You can confirm this with the following
1119 ps -Zax | grep guix-daemon
1122 Monitor the SELinux log files as you run a command like @code{guix build
1123 hello} to convince yourself that SELinux permits all necessary
1126 @subsubsection Limitations
1127 @cindex SELinux, limitations
1129 This policy is not perfect. Here is a list of limitations or quirks
1130 that should be considered when deploying the provided SELinux policy for
1135 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1136 operations involve contexts that have anything to do with
1137 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1138 but it would be preferrable to define socket rules for only this label.
1141 @code{guix gc} cannot access arbitrary links to profiles. By design,
1142 the file label of the destination of a symlink is independent of the
1143 file label of the link itself. Although all profiles under
1144 $localstatedir are labelled, the links to these profiles inherit the
1145 label of the directory they are in. For links in the user’s home
1146 directory this will be @code{user_home_t}. But for links from the root
1147 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1148 directory, etc, this won’t work. @code{guix gc} would be prevented from
1149 reading and following these links.
1152 The daemon’s feature to listen for TCP connections might no longer work.
1153 This might require extra rules, because SELinux treats network sockets
1154 differently from files.
1157 Currently all files with a name matching the regular expression
1158 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1159 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1160 that name in any profile would be permitted to run in the
1161 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1162 build a package that provides this executable and convince a user to
1163 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1164 At that point SELinux could not prevent it from accessing files that are
1165 allowed for processes in that domain.
1167 We could generate a much more restrictive policy at installation time,
1168 so that only the @emph{exact} file name of the currently installed
1169 @code{guix-daemon} executable would be labelled with
1170 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1171 The downside is that root would have to install or upgrade the policy at
1172 installation time whenever the Guix package that provides the
1173 effectively running @code{guix-daemon} executable is upgraded.
1176 @node Invoking guix-daemon
1177 @section Invoking @command{guix-daemon}
1179 The @command{guix-daemon} program implements all the functionality to
1180 access the store. This includes launching build processes, running the
1181 garbage collector, querying the availability of a build result, etc. It
1182 is normally run as @code{root} like this:
1185 # guix-daemon --build-users-group=guixbuild
1189 For details on how to set it up, @pxref{Setting Up the Daemon}.
1192 @cindex container, build environment
1193 @cindex build environment
1194 @cindex reproducible builds
1195 By default, @command{guix-daemon} launches build processes under
1196 different UIDs, taken from the build group specified with
1197 @code{--build-users-group}. In addition, each build process is run in a
1198 chroot environment that only contains the subset of the store that the
1199 build process depends on, as specified by its derivation
1200 (@pxref{Programming Interface, derivation}), plus a set of specific
1201 system directories. By default, the latter contains @file{/dev} and
1202 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1203 @dfn{container}: in addition to having its own file system tree, it has
1204 a separate mount name space, its own PID name space, network name space,
1205 etc. This helps achieve reproducible builds (@pxref{Features}).
1207 When the daemon performs a build on behalf of the user, it creates a
1208 build directory under @file{/tmp} or under the directory specified by
1209 its @code{TMPDIR} environment variable; this directory is shared with
1210 the container for the duration of the build. Be aware that using a
1211 directory other than @file{/tmp} can affect build results---for example,
1212 with a longer directory name, a build process that uses Unix-domain
1213 sockets might hit the name length limitation for @code{sun_path}, which
1214 it would otherwise not hit.
1216 The build directory is automatically deleted upon completion, unless the
1217 build failed and the client specified @option{--keep-failed}
1218 (@pxref{Invoking guix build, @option{--keep-failed}}).
1220 The following command-line options are supported:
1223 @item --build-users-group=@var{group}
1224 Take users from @var{group} to run build processes (@pxref{Setting Up
1225 the Daemon, build users}).
1227 @item --no-substitutes
1229 Do not use substitutes for build products. That is, always build things
1230 locally instead of allowing downloads of pre-built binaries
1231 (@pxref{Substitutes}).
1233 When the daemon runs with @code{--no-substitutes}, clients can still
1234 explicitly enable substitution @i{via} the @code{set-build-options}
1235 remote procedure call (@pxref{The Store}).
1237 @item --substitute-urls=@var{urls}
1238 @anchor{daemon-substitute-urls}
1239 Consider @var{urls} the default whitespace-separated list of substitute
1240 source URLs. When this option is omitted,
1241 @indicateurl{https://mirror.hydra.gnu.org https://hydra.gnu.org} is used
1242 (@code{mirror.hydra.gnu.org} is a mirror of @code{hydra.gnu.org}).
1244 This means that substitutes may be downloaded from @var{urls}, as long
1245 as they are signed by a trusted signature (@pxref{Substitutes}).
1248 @item --no-build-hook
1249 Do not use the @dfn{build hook}.
1251 The build hook is a helper program that the daemon can start and to
1252 which it submits build requests. This mechanism is used to offload
1253 builds to other machines (@pxref{Daemon Offload Setup}).
1255 @item --cache-failures
1256 Cache build failures. By default, only successful builds are cached.
1258 When this option is used, @command{guix gc --list-failures} can be used
1259 to query the set of store items marked as failed; @command{guix gc
1260 --clear-failures} removes store items from the set of cached failures.
1261 @xref{Invoking guix gc}.
1263 @item --cores=@var{n}
1265 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1268 The default value is @code{0}, but it may be overridden by clients, such
1269 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1272 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1273 in the build process, which can then use it to exploit internal
1274 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1276 @item --max-jobs=@var{n}
1278 Allow at most @var{n} build jobs in parallel. The default value is
1279 @code{1}. Setting it to @code{0} means that no builds will be performed
1280 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1281 Setup}), or simply fail.
1283 @item --max-silent-time=@var{seconds}
1284 When the build or substitution process remains silent for more than
1285 @var{seconds}, terminate it and report a build failure.
1287 The default value is @code{0}, which disables the timeout.
1289 The value specified here can be overridden by clients (@pxref{Common
1290 Build Options, @code{--max-silent-time}}).
1292 @item --timeout=@var{seconds}
1293 Likewise, when the build or substitution process lasts for more than
1294 @var{seconds}, terminate it and report a build failure.
1296 The default value is @code{0}, which disables the timeout.
1298 The value specified here can be overridden by clients (@pxref{Common
1299 Build Options, @code{--timeout}}).
1301 @item --rounds=@var{N}
1302 Build each derivation @var{n} times in a row, and raise an error if
1303 consecutive build results are not bit-for-bit identical. Note that this
1304 setting can be overridden by clients such as @command{guix build}
1305 (@pxref{Invoking guix build}).
1307 When used in conjunction with @option{--keep-failed}, the differing
1308 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1309 This makes it easy to look for differences between the two results.
1312 Produce debugging output.
1314 This is useful to debug daemon start-up issues, but then it may be
1315 overridden by clients, for example the @code{--verbosity} option of
1316 @command{guix build} (@pxref{Invoking guix build}).
1318 @item --chroot-directory=@var{dir}
1319 Add @var{dir} to the build chroot.
1321 Doing this may change the result of build processes---for instance if
1322 they use optional dependencies found in @var{dir} when it is available,
1323 and not otherwise. For that reason, it is not recommended to do so.
1324 Instead, make sure that each derivation declares all the inputs that it
1327 @item --disable-chroot
1328 Disable chroot builds.
1330 Using this option is not recommended since, again, it would allow build
1331 processes to gain access to undeclared dependencies. It is necessary,
1332 though, when @command{guix-daemon} is running under an unprivileged user
1335 @item --log-compression=@var{type}
1336 Compress build logs according to @var{type}, one of @code{gzip},
1337 @code{bzip2}, or @code{none}.
1339 Unless @code{--lose-logs} is used, all the build logs are kept in the
1340 @var{localstatedir}. To save space, the daemon automatically compresses
1341 them with bzip2 by default.
1343 @item --disable-deduplication
1344 @cindex deduplication
1345 Disable automatic file ``deduplication'' in the store.
1347 By default, files added to the store are automatically ``deduplicated'':
1348 if a newly added file is identical to another one found in the store,
1349 the daemon makes the new file a hard link to the other file. This can
1350 noticeably reduce disk usage, at the expense of slightly increased
1351 input/output load at the end of a build process. This option disables
1354 @item --gc-keep-outputs[=yes|no]
1355 Tell whether the garbage collector (GC) must keep outputs of live
1359 @cindex garbage collector roots
1360 When set to ``yes'', the GC will keep the outputs of any live derivation
1361 available in the store---the @code{.drv} files. The default is ``no'',
1362 meaning that derivation outputs are kept only if they are GC roots.
1363 @xref{Invoking guix gc}, for more on GC roots.
1365 @item --gc-keep-derivations[=yes|no]
1366 Tell whether the garbage collector (GC) must keep derivations
1367 corresponding to live outputs.
1369 When set to ``yes'', as is the case by default, the GC keeps
1370 derivations---i.e., @code{.drv} files---as long as at least one of their
1371 outputs is live. This allows users to keep track of the origins of
1372 items in their store. Setting it to ``no'' saves a bit of disk space.
1374 Note that when both @code{--gc-keep-derivations} and
1375 @code{--gc-keep-outputs} are used, the effect is to keep all the build
1376 prerequisites (the sources, compiler, libraries, and other build-time
1377 tools) of live objects in the store, regardless of whether these
1378 prerequisites are live. This is convenient for developers since it
1379 saves rebuilds or downloads.
1381 @item --impersonate-linux-2.6
1382 On Linux-based systems, impersonate Linux 2.6. This means that the
1383 kernel's @code{uname} system call will report 2.6 as the release number.
1385 This might be helpful to build programs that (usually wrongfully) depend
1386 on the kernel version number.
1389 Do not keep build logs. By default they are kept under
1390 @code{@var{localstatedir}/guix/log}.
1392 @item --system=@var{system}
1393 Assume @var{system} as the current system type. By default it is the
1394 architecture/kernel pair found at configure time, such as
1395 @code{x86_64-linux}.
1397 @item --listen=@var{endpoint}
1398 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1399 as the file name of a Unix-domain socket if it starts with
1400 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1401 host name or host name and port to listen to. Here are a few examples:
1404 @item --listen=/gnu/var/daemon
1405 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1406 creating it if needed.
1408 @item --listen=localhost
1409 @cindex daemon, remote access
1410 @cindex remote access to the daemon
1411 @cindex daemon, cluster setup
1412 @cindex clusters, daemon setup
1413 Listen for TCP connections on the network interface corresponding to
1414 @code{localhost}, on port 44146.
1416 @item --listen=128.0.0.42:1234
1417 Listen for TCP connections on the network interface corresponding to
1418 @code{128.0.0.42}, on port 1234.
1421 This option can be repeated multiple times, in which case
1422 @command{guix-daemon} accepts connections on all the specified
1423 endpoints. Users can tell client commands what endpoint to connect to
1424 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1425 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1428 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1429 @code{--listen=@var{host}} is suitable on local networks, such as
1430 clusters, where only trusted nodes may connect to the build daemon. In
1431 other cases where remote access to the daemon is needed, we recommend
1432 using Unix-domain sockets along with SSH.
1435 When @code{--listen} is omitted, @command{guix-daemon} listens for
1436 connections on the Unix-domain socket located at
1437 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1441 @node Application Setup
1442 @section Application Setup
1444 @cindex foreign distro
1445 When using Guix on top of GNU/Linux distribution other than GuixSD---a
1446 so-called @dfn{foreign distro}---a few additional steps are needed to
1447 get everything in place. Here are some of them.
1451 @anchor{locales-and-locpath}
1452 @cindex locales, when not on GuixSD
1454 @vindex GUIX_LOCPATH
1455 Packages installed @i{via} Guix will not use the locale data of the
1456 host system. Instead, you must first install one of the locale packages
1457 available with Guix and then define the @code{GUIX_LOCPATH} environment
1461 $ guix package -i glibc-locales
1462 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1465 Note that the @code{glibc-locales} package contains data for all the
1466 locales supported by the GNU@tie{}libc and weighs in at around
1467 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1468 limited to a few UTF-8 locales.
1470 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1471 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1472 Manual}). There are two important differences though:
1476 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1477 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1478 to make sure the programs of the foreign distro will not end up loading
1479 incompatible locale data.
1482 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1483 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1484 should your Guix profile contain a mixture of programs linked against
1485 different libc version, each libc version will only try to load locale
1486 data in the right format.
1489 This is important because the locale data format used by different libc
1490 versions may be incompatible.
1492 @subsection Name Service Switch
1494 @cindex name service switch, glibc
1495 @cindex NSS (name service switch), glibc
1496 @cindex nscd (name service caching daemon)
1497 @cindex name service caching daemon (nscd)
1498 When using Guix on a foreign distro, we @emph{strongly recommend} that
1499 the system run the GNU C library's @dfn{name service cache daemon},
1500 @command{nscd}, which should be listening on the
1501 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1502 installed with Guix may fail to look up host names or user accounts, or
1503 may even crash. The next paragraphs explain why.
1505 @cindex @file{nsswitch.conf}
1506 The GNU C library implements a @dfn{name service switch} (NSS), which is
1507 an extensible mechanism for ``name lookups'' in general: host name
1508 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1509 The GNU C Library Reference Manual}).
1511 @cindex Network information service (NIS)
1512 @cindex NIS (Network information service)
1513 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1514 lookup implementations: for example, the @code{nss-mdns} plugin allow
1515 resolution of @code{.local} host names, the @code{nis} plugin allows
1516 user account lookup using the Network information service (NIS), and so
1517 on. These extra ``lookup services'' are configured system-wide in
1518 @file{/etc/nsswitch.conf}, and all the programs running on the system
1519 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1522 When they perform a name lookup---for instance by calling the
1523 @code{getaddrinfo} function in C---applications first try to connect to
1524 the nscd; on success, nscd performs name lookups on their behalf. If
1525 the nscd is not running, then they perform the name lookup by
1526 themselves, by loading the name lookup services into their own address
1527 space and running it. These name lookup services---the
1528 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1529 the host system's C library, rather than from the C library the
1530 application is linked against (the C library coming from Guix).
1532 And this is where the problem is: if your application is linked against
1533 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1534 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1535 likely crash or have its name lookups fail unexpectedly.
1537 Running @command{nscd} on the system, among other advantages, eliminates
1538 this binary incompatibility problem because those @code{libnss_*.so}
1539 files are loaded in the @command{nscd} process, not in applications
1542 @subsection X11 Fonts
1545 The majority of graphical applications use Fontconfig to locate and
1546 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1547 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1548 by default. Thus, to allow graphical applications installed with Guix
1549 to display fonts, you have to install fonts with Guix as well.
1550 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1551 @code{font-gnu-freefont-ttf}.
1553 To display text written in Chinese languages, Japanese, or Korean in
1554 graphical applications, consider installing
1555 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1556 has multiple outputs, one per language family (@pxref{Packages with
1557 Multiple Outputs}). For instance, the following command installs fonts
1558 for Chinese languages:
1561 guix package -i font-adobe-source-han-sans:cn
1564 @cindex @code{xterm}
1565 Older programs such as @command{xterm} do not use Fontconfig and instead
1566 rely on server-side font rendering. Such programs require to specify a
1567 full name of a font using XLFD (X Logical Font Description), like this:
1570 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1573 To be able to use such full names for the TrueType fonts installed in
1574 your Guix profile, you need to extend the font path of the X server:
1576 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1577 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1579 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1582 @cindex @code{xlsfonts}
1583 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1584 to make sure your TrueType fonts are listed there.
1586 @cindex @code{fc-cache}
1588 After installing fonts you may have to refresh the font cache to use
1589 them in applications. The same applies when applications installed via
1590 Guix do not seem to find fonts. To force rebuilding of the font cache
1591 run @code{fc-cache -f}. The @code{fc-cache} command is provided by the
1592 @code{fontconfig} package.
1594 @subsection X.509 Certificates
1596 @cindex @code{nss-certs}
1597 The @code{nss-certs} package provides X.509 certificates, which allow
1598 programs to authenticate Web servers accessed over HTTPS.
1600 When using Guix on a foreign distro, you can install this package and
1601 define the relevant environment variables so that packages know where to
1602 look for certificates. @xref{X.509 Certificates}, for detailed
1605 @subsection Emacs Packages
1607 @cindex @code{emacs}
1608 When you install Emacs packages with Guix, the elisp files may be placed
1609 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1611 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1612 directory exists because potentially there may exist thousands of Emacs
1613 packages and storing all their files in a single directory may not be
1614 reliable (because of name conflicts). So we think using a separate
1615 directory for each package is a good idea. It is very similar to how
1616 the Emacs package system organizes the file structure (@pxref{Package
1617 Files,,, emacs, The GNU Emacs Manual}).
1619 By default, Emacs (installed with Guix) ``knows'' where these packages
1620 are placed, so you do not need to perform any configuration. If, for
1621 some reason, you want to avoid auto-loading Emacs packages installed
1622 with Guix, you can do so by running Emacs with @code{--no-site-file}
1623 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1625 @subsection The GCC toolchain
1630 Guix offers individual compiler packages such as @code{gcc} but if you
1631 are in need of a complete toolchain for compiling and linking source
1632 code what you really want is the @code{gcc-toolchain} package. This
1633 package provides a complete GCC toolchain for C/C++ development,
1634 including GCC itself, the GNU C Library (headers and binaries, plus
1635 debugging symbols in the @code{debug} output), Binutils, and a linker
1638 @cindex attempt to use impure library, error message
1640 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1641 passed to the linker, add corresponding @code{-rpath} arguments, and
1642 invoke the actual linker with this new set of arguments. By default,
1643 the linker wrapper refuses to link to libraries outside the store to
1644 ensure ``purity''. This can be annoying when using the toolchain to
1645 link with local libraries. To allow references to libraries outside the
1646 store you need to define the environment variable
1647 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES}.
1651 @c *********************************************************************
1652 @node Package Management
1653 @chapter Package Management
1656 The purpose of GNU Guix is to allow users to easily install, upgrade, and
1657 remove software packages, without having to know about their build
1658 procedures or dependencies. Guix also goes beyond this obvious set of
1661 This chapter describes the main features of Guix, as well as the
1662 package management tools it provides. Along with the command-line
1663 interface described below (@pxref{Invoking guix package, @code{guix
1664 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
1665 emacs-guix, The Emacs-Guix Reference Manual}), after installing
1666 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
1670 guix package -i emacs-guix
1674 * Features:: How Guix will make your life brighter.
1675 * Invoking guix package:: Package installation, removal, etc.
1676 * Substitutes:: Downloading pre-built binaries.
1677 * Packages with Multiple Outputs:: Single source package, multiple outputs.
1678 * Invoking guix gc:: Running the garbage collector.
1679 * Invoking guix pull:: Fetching the latest Guix and distribution.
1680 * Invoking guix pack:: Creating software bundles.
1681 * Invoking guix archive:: Exporting and importing store files.
1687 When using Guix, each package ends up in the @dfn{package store}, in its
1688 own directory---something that resembles
1689 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
1691 Instead of referring to these directories, users have their own
1692 @dfn{profile}, which points to the packages that they actually want to
1693 use. These profiles are stored within each user's home directory, at
1694 @code{$HOME/.guix-profile}.
1696 For example, @code{alice} installs GCC 4.7.2. As a result,
1697 @file{/home/alice/.guix-profile/bin/gcc} points to
1698 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
1699 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
1700 simply continues to point to
1701 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
1702 coexist on the same system without any interference.
1704 The @command{guix package} command is the central tool to manage
1705 packages (@pxref{Invoking guix package}). It operates on the per-user
1706 profiles, and can be used @emph{with normal user privileges}.
1708 @cindex transactions
1709 The command provides the obvious install, remove, and upgrade
1710 operations. Each invocation is actually a @emph{transaction}: either
1711 the specified operation succeeds, or nothing happens. Thus, if the
1712 @command{guix package} process is terminated during the transaction,
1713 or if a power outage occurs during the transaction, then the user's
1714 profile remains in its previous state, and remains usable.
1716 In addition, any package transaction may be @emph{rolled back}. So, if,
1717 for example, an upgrade installs a new version of a package that turns
1718 out to have a serious bug, users may roll back to the previous instance
1719 of their profile, which was known to work well. Similarly, the global
1720 system configuration on GuixSD is subject to
1721 transactional upgrades and roll-back
1722 (@pxref{Using the Configuration System}).
1724 All packages in the package store may be @emph{garbage-collected}.
1725 Guix can determine which packages are still referenced by user
1726 profiles, and remove those that are provably no longer referenced
1727 (@pxref{Invoking guix gc}). Users may also explicitly remove old
1728 generations of their profile so that the packages they refer to can be
1731 @cindex reproducibility
1732 @cindex reproducible builds
1733 Finally, Guix takes a @dfn{purely functional} approach to package
1734 management, as described in the introduction (@pxref{Introduction}).
1735 Each @file{/gnu/store} package directory name contains a hash of all the
1736 inputs that were used to build that package---compiler, libraries, build
1737 scripts, etc. This direct correspondence allows users to make sure a
1738 given package installation matches the current state of their
1739 distribution. It also helps maximize @dfn{build reproducibility}:
1740 thanks to the isolated build environments that are used, a given build
1741 is likely to yield bit-identical files when performed on different
1742 machines (@pxref{Invoking guix-daemon, container}).
1745 This foundation allows Guix to support @dfn{transparent binary/source
1746 deployment}. When a pre-built binary for a @file{/gnu/store} item is
1747 available from an external source---a @dfn{substitute}, Guix just
1748 downloads it and unpacks it;
1749 otherwise, it builds the package from source, locally
1750 (@pxref{Substitutes}). Because build results are usually bit-for-bit
1751 reproducible, users do not have to trust servers that provide
1752 substitutes: they can force a local build and @emph{challenge} providers
1753 (@pxref{Invoking guix challenge}).
1755 Control over the build environment is a feature that is also useful for
1756 developers. The @command{guix environment} command allows developers of
1757 a package to quickly set up the right development environment for their
1758 package, without having to manually install the dependencies of the
1759 package into their profile (@pxref{Invoking guix environment}).
1761 @node Invoking guix package
1762 @section Invoking @command{guix package}
1764 @cindex installing packages
1765 @cindex removing packages
1766 @cindex package installation
1767 @cindex package removal
1768 The @command{guix package} command is the tool that allows users to
1769 install, upgrade, and remove packages, as well as rolling back to
1770 previous configurations. It operates only on the user's own profile,
1771 and works with normal user privileges (@pxref{Features}). Its syntax
1775 guix package @var{options}
1777 @cindex transactions
1778 Primarily, @var{options} specifies the operations to be performed during
1779 the transaction. Upon completion, a new profile is created, but
1780 previous @dfn{generations} of the profile remain available, should the user
1783 For example, to remove @code{lua} and install @code{guile} and
1784 @code{guile-cairo} in a single transaction:
1787 guix package -r lua -i guile guile-cairo
1790 @command{guix package} also supports a @dfn{declarative approach}
1791 whereby the user specifies the exact set of packages to be available and
1792 passes it @i{via} the @option{--manifest} option
1793 (@pxref{profile-manifest, @option{--manifest}}).
1796 For each user, a symlink to the user's default profile is automatically
1797 created in @file{$HOME/.guix-profile}. This symlink always points to the
1798 current generation of the user's default profile. Thus, users can add
1799 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
1800 variable, and so on.
1801 @cindex search paths
1802 If you are not using the Guix System Distribution, consider adding the
1803 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
1804 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
1805 shells get all the right environment variable definitions:
1808 GUIX_PROFILE="$HOME/.guix-profile" ; \
1809 source "$HOME/.guix-profile/etc/profile"
1812 In a multi-user setup, user profiles are stored in a place registered as
1813 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
1814 to (@pxref{Invoking guix gc}). That directory is normally
1815 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
1816 @var{localstatedir} is the value passed to @code{configure} as
1817 @code{--localstatedir}, and @var{user} is the user name. The
1818 @file{per-user} directory is created when @command{guix-daemon} is
1819 started, and the @var{user} sub-directory is created by @command{guix
1822 The @var{options} can be among the following:
1826 @item --install=@var{package} @dots{}
1827 @itemx -i @var{package} @dots{}
1828 Install the specified @var{package}s.
1830 Each @var{package} may specify either a simple package name, such as
1831 @code{guile}, or a package name followed by an at-sign and version number,
1832 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
1833 case, the newest version prefixed by @code{1.8} is selected.)
1835 If no version number is specified, the
1836 newest available version will be selected. In addition, @var{package}
1837 may contain a colon, followed by the name of one of the outputs of the
1838 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
1839 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
1840 name (and optionally version) are searched for among the GNU
1841 distribution modules (@pxref{Package Modules}).
1843 @cindex propagated inputs
1844 Sometimes packages have @dfn{propagated inputs}: these are dependencies
1845 that automatically get installed along with the required package
1846 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
1847 @code{package} objects}, for information about propagated inputs in
1848 package definitions).
1850 @anchor{package-cmd-propagated-inputs}
1851 An example is the GNU MPC library: its C header files refer to those of
1852 the GNU MPFR library, which in turn refer to those of the GMP library.
1853 Thus, when installing MPC, the MPFR and GMP libraries also get installed
1854 in the profile; removing MPC also removes MPFR and GMP---unless they had
1855 also been explicitly installed by the user.
1857 Besides, packages sometimes rely on the definition of environment
1858 variables for their search paths (see explanation of
1859 @code{--search-paths} below). Any missing or possibly incorrect
1860 environment variable definitions are reported here.
1862 @item --install-from-expression=@var{exp}
1864 Install the package @var{exp} evaluates to.
1866 @var{exp} must be a Scheme expression that evaluates to a
1867 @code{<package>} object. This option is notably useful to disambiguate
1868 between same-named variants of a package, with expressions such as
1869 @code{(@@ (gnu packages base) guile-final)}.
1871 Note that this option installs the first output of the specified
1872 package, which may be insufficient when needing a specific output of a
1873 multiple-output package.
1875 @item --install-from-file=@var{file}
1876 @itemx -f @var{file}
1877 Install the package that the code within @var{file} evaluates to.
1879 As an example, @var{file} might contain a definition like this
1880 (@pxref{Defining Packages}):
1883 @verbatiminclude package-hello.scm
1886 Developers may find it useful to include such a @file{guix.scm} file
1887 in the root of their project source tree that can be used to test
1888 development snapshots and create reproducible development environments
1889 (@pxref{Invoking guix environment}).
1891 @item --remove=@var{package} @dots{}
1892 @itemx -r @var{package} @dots{}
1893 Remove the specified @var{package}s.
1895 As for @code{--install}, each @var{package} may specify a version number
1896 and/or output name in addition to the package name. For instance,
1897 @code{-r glibc:debug} would remove the @code{debug} output of
1900 @item --upgrade[=@var{regexp} @dots{}]
1901 @itemx -u [@var{regexp} @dots{}]
1902 @cindex upgrading packages
1903 Upgrade all the installed packages. If one or more @var{regexp}s are
1904 specified, upgrade only installed packages whose name matches a
1905 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
1907 Note that this upgrades package to the latest version of packages found
1908 in the distribution currently installed. To update your distribution,
1909 you should regularly run @command{guix pull} (@pxref{Invoking guix
1912 @item --do-not-upgrade[=@var{regexp} @dots{}]
1913 When used together with the @code{--upgrade} option, do @emph{not}
1914 upgrade any packages whose name matches a @var{regexp}. For example, to
1915 upgrade all packages in the current profile except those containing the
1916 substring ``emacs'':
1919 $ guix package --upgrade . --do-not-upgrade emacs
1922 @item @anchor{profile-manifest}--manifest=@var{file}
1923 @itemx -m @var{file}
1924 @cindex profile declaration
1925 @cindex profile manifest
1926 Create a new generation of the profile from the manifest object
1927 returned by the Scheme code in @var{file}.
1929 This allows you to @emph{declare} the profile's contents rather than
1930 constructing it through a sequence of @code{--install} and similar
1931 commands. The advantage is that @var{file} can be put under version
1932 control, copied to different machines to reproduce the same profile, and
1935 @c FIXME: Add reference to (guix profile) documentation when available.
1936 @var{file} must return a @dfn{manifest} object, which is roughly a list
1939 @findex packages->manifest
1941 (use-package-modules guile emacs)
1946 ;; Use a specific package output.
1947 (list guile-2.0 "debug")))
1950 @findex specifications->manifest
1951 In this example we have to know which modules define the @code{emacs}
1952 and @code{guile-2.0} variables to provide the right
1953 @code{use-package-modules} line, which can be cumbersome. We can
1954 instead provide regular package specifications and let
1955 @code{specifications->manifest} look up the corresponding package
1959 (specifications->manifest
1960 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
1964 @cindex rolling back
1965 @cindex undoing transactions
1966 @cindex transactions, undoing
1967 Roll back to the previous @dfn{generation} of the profile---i.e., undo
1968 the last transaction.
1970 When combined with options such as @code{--install}, roll back occurs
1971 before any other actions.
1973 When rolling back from the first generation that actually contains
1974 installed packages, the profile is made to point to the @dfn{zeroth
1975 generation}, which contains no files apart from its own metadata.
1977 After having rolled back, installing, removing, or upgrading packages
1978 overwrites previous future generations. Thus, the history of the
1979 generations in a profile is always linear.
1981 @item --switch-generation=@var{pattern}
1982 @itemx -S @var{pattern}
1984 Switch to a particular generation defined by @var{pattern}.
1986 @var{pattern} may be either a generation number or a number prefixed
1987 with ``+'' or ``-''. The latter means: move forward/backward by a
1988 specified number of generations. For example, if you want to return to
1989 the latest generation after @code{--roll-back}, use
1990 @code{--switch-generation=+1}.
1992 The difference between @code{--roll-back} and
1993 @code{--switch-generation=-1} is that @code{--switch-generation} will
1994 not make a zeroth generation, so if a specified generation does not
1995 exist, the current generation will not be changed.
1997 @item --search-paths[=@var{kind}]
1998 @cindex search paths
1999 Report environment variable definitions, in Bash syntax, that may be
2000 needed in order to use the set of installed packages. These environment
2001 variables are used to specify @dfn{search paths} for files used by some
2002 of the installed packages.
2004 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2005 environment variables to be defined so it can look for headers and
2006 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2007 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2008 library are installed in the profile, then @code{--search-paths} will
2009 suggest setting these variables to @code{@var{profile}/include} and
2010 @code{@var{profile}/lib}, respectively.
2012 The typical use case is to define these environment variables in the
2016 $ eval `guix package --search-paths`
2019 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2020 meaning that the returned environment variable definitions will either
2021 be exact settings, or prefixes or suffixes of the current value of these
2022 variables. When omitted, @var{kind} defaults to @code{exact}.
2024 This option can also be used to compute the @emph{combined} search paths
2025 of several profiles. Consider this example:
2028 $ guix package -p foo -i guile
2029 $ guix package -p bar -i guile-json
2030 $ guix package -p foo -p bar --search-paths
2033 The last command above reports about the @code{GUILE_LOAD_PATH}
2034 variable, even though, taken individually, neither @file{foo} nor
2035 @file{bar} would lead to that recommendation.
2038 @item --profile=@var{profile}
2039 @itemx -p @var{profile}
2040 Use @var{profile} instead of the user's default profile.
2043 Produce verbose output. In particular, emit the build log of the
2044 environment on the standard error port.
2047 Use the bootstrap Guile to build the profile. This option is only
2048 useful to distribution developers.
2052 In addition to these actions, @command{guix package} supports the
2053 following options to query the current state of a profile, or the
2054 availability of packages:
2058 @item --search=@var{regexp}
2059 @itemx -s @var{regexp}
2060 @cindex searching for packages
2061 List the available packages whose name, synopsis, or description matches
2062 @var{regexp}, sorted by relevance. Print all the metadata of matching packages in
2063 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
2064 GNU recutils manual}).
2066 This allows specific fields to be extracted using the @command{recsel}
2067 command, for instance:
2070 $ guix package -s malloc | recsel -p name,version,relevance
2084 Similarly, to show the name of all the packages available under the
2085 terms of the GNU@tie{}LGPL version 3:
2088 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
2095 It is also possible to refine search results using several @code{-s}
2096 flags. For example, the following command returns a list of board
2100 $ guix package -s '\<board\>' -s game | recsel -p name
2105 If we were to omit @code{-s game}, we would also get software packages
2106 that deal with printed circuit boards; removing the angle brackets
2107 around @code{board} would further add packages that have to do with
2110 And now for a more elaborate example. The following command searches
2111 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
2112 libraries, and prints the name and synopsis of the matching packages:
2115 $ guix package -s crypto -s library | \
2116 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
2120 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
2121 information on @dfn{selection expressions} for @code{recsel -e}.
2123 @item --show=@var{package}
2124 Show details about @var{package}, taken from the list of available packages, in
2125 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
2129 $ guix package --show=python | recsel -p name,version
2137 You may also specify the full name of a package to only get details about a
2138 specific version of it:
2140 $ guix package --show=python@@3.4 | recsel -p name,version
2147 @item --list-installed[=@var{regexp}]
2148 @itemx -I [@var{regexp}]
2149 List the currently installed packages in the specified profile, with the
2150 most recently installed packages shown last. When @var{regexp} is
2151 specified, list only installed packages whose name matches @var{regexp}.
2153 For each installed package, print the following items, separated by
2154 tabs: the package name, its version string, the part of the package that
2155 is installed (for instance, @code{out} for the default output,
2156 @code{include} for its headers, etc.), and the path of this package in
2159 @item --list-available[=@var{regexp}]
2160 @itemx -A [@var{regexp}]
2161 List packages currently available in the distribution for this system
2162 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
2163 installed packages whose name matches @var{regexp}.
2165 For each package, print the following items separated by tabs: its name,
2166 its version string, the parts of the package (@pxref{Packages with
2167 Multiple Outputs}), and the source location of its definition.
2169 @item --list-generations[=@var{pattern}]
2170 @itemx -l [@var{pattern}]
2172 Return a list of generations along with their creation dates; for each
2173 generation, show the installed packages, with the most recently
2174 installed packages shown last. Note that the zeroth generation is never
2177 For each installed package, print the following items, separated by
2178 tabs: the name of a package, its version string, the part of the package
2179 that is installed (@pxref{Packages with Multiple Outputs}), and the
2180 location of this package in the store.
2182 When @var{pattern} is used, the command returns only matching
2183 generations. Valid patterns include:
2186 @item @emph{Integers and comma-separated integers}. Both patterns denote
2187 generation numbers. For instance, @code{--list-generations=1} returns
2190 And @code{--list-generations=1,8,2} outputs three generations in the
2191 specified order. Neither spaces nor trailing commas are allowed.
2193 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
2194 specified generations and everything in between. Note that the start of
2195 a range must be smaller than its end.
2197 It is also possible to omit the endpoint. For example,
2198 @code{--list-generations=2..}, returns all generations starting from the
2201 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
2202 or months by passing an integer along with the first letter of the
2203 duration. For example, @code{--list-generations=20d} lists generations
2204 that are up to 20 days old.
2207 @item --delete-generations[=@var{pattern}]
2208 @itemx -d [@var{pattern}]
2209 When @var{pattern} is omitted, delete all generations except the current
2212 This command accepts the same patterns as @option{--list-generations}.
2213 When @var{pattern} is specified, delete the matching generations. When
2214 @var{pattern} specifies a duration, generations @emph{older} than the
2215 specified duration match. For instance, @code{--delete-generations=1m}
2216 deletes generations that are more than one month old.
2218 If the current generation matches, it is @emph{not} deleted. Also, the
2219 zeroth generation is never deleted.
2221 Note that deleting generations prevents rolling back to them.
2222 Consequently, this command must be used with care.
2226 Finally, since @command{guix package} may actually start build
2227 processes, it supports all the common build options (@pxref{Common Build
2228 Options}). It also supports package transformation options, such as
2229 @option{--with-source} (@pxref{Package Transformation Options}).
2230 However, note that package transformations are lost when upgrading; to
2231 preserve transformations across upgrades, you should define your own
2232 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
2233 (@pxref{Defining Packages}).
2236 @section Substitutes
2239 @cindex pre-built binaries
2240 Guix supports transparent source/binary deployment, which means that it
2241 can either build things locally, or download pre-built items from a
2242 server, or both. We call these pre-built items @dfn{substitutes}---they
2243 are substitutes for local build results. In many cases, downloading a
2244 substitute is much faster than building things locally.
2246 Substitutes can be anything resulting from a derivation build
2247 (@pxref{Derivations}). Of course, in the common case, they are
2248 pre-built package binaries, but source tarballs, for instance, which
2249 also result from derivation builds, can be available as substitutes.
2252 * Official Substitute Server:: One particular source of substitutes.
2253 * Substitute Server Authorization:: How to enable or disable substitutes.
2254 * Substitute Authentication:: How Guix verifies substitutes.
2255 * Proxy Settings:: How to get substitutes via proxy.
2256 * Substitution Failure:: What happens when substitution fails.
2257 * On Trusting Binaries:: How can you trust that binary blob?
2260 @node Official Substitute Server
2261 @subsection Official Substitute Server
2265 The @code{mirror.hydra.gnu.org} server is a front-end to an official build farm
2266 that builds packages from Guix continuously for some
2267 architectures, and makes them available as substitutes. This is the
2268 default source of substitutes; it can be overridden by passing the
2269 @option{--substitute-urls} option either to @command{guix-daemon}
2270 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
2271 or to client tools such as @command{guix package}
2272 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
2275 Substitute URLs can be either HTTP or HTTPS.
2276 HTTPS is recommended because communications are encrypted; conversely,
2277 using HTTP makes all communications visible to an eavesdropper, who
2278 could use the information gathered to determine, for instance, whether
2279 your system has unpatched security vulnerabilities.
2281 Substitutes from the official build farm are enabled by default when
2282 using the Guix System Distribution (@pxref{GNU Distribution}). However,
2283 they are disabled by default when using Guix on a foreign distribution,
2284 unless you have explicitly enabled them via one of the recommended
2285 installation steps (@pxref{Installation}). The following paragraphs
2286 describe how to enable or disable substitutes for the official build
2287 farm; the same procedure can also be used to enable substitutes for any
2288 other substitute server.
2290 @node Substitute Server Authorization
2291 @subsection Substitute Server Authorization
2294 @cindex substitutes, authorization thereof
2295 @cindex access control list (ACL), for substitutes
2296 @cindex ACL (access control list), for substitutes
2297 To allow Guix to download substitutes from @code{hydra.gnu.org} or a
2299 must add its public key to the access control list (ACL) of archive
2300 imports, using the @command{guix archive} command (@pxref{Invoking guix
2301 archive}). Doing so implies that you trust @code{hydra.gnu.org} to not
2302 be compromised and to serve genuine substitutes.
2304 The public key for @code{hydra.gnu.org} is installed along with Guix, in
2305 @code{@var{prefix}/share/guix/hydra.gnu.org.pub}, where @var{prefix} is
2306 the installation prefix of Guix. If you installed Guix from source,
2307 make sure you checked the GPG signature of
2308 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
2309 Then, you can run something like this:
2312 # guix archive --authorize < @var{prefix}/share/guix/hydra.gnu.org.pub
2316 Similarly, the @file{berlin.guixsd.org.pub} file contains the public key
2317 for the project's new build farm, reachable at
2318 @indicateurl{https://berlin.guixsd.org}.
2320 As of this writing @code{berlin.guixsd.org} is being upgraded so it can
2321 better scale up, but you might want to give it a try. It is backed by
2322 20 x86_64/i686 build nodes and may be able to provide substitutes more
2323 quickly than @code{mirror.hydra.gnu.org}.
2326 Once this is in place, the output of a command like @code{guix build}
2327 should change from something like:
2330 $ guix build emacs --dry-run
2331 The following derivations would be built:
2332 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
2333 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
2334 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
2335 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
2343 $ guix build emacs --dry-run
2344 112.3 MB would be downloaded:
2345 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
2346 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
2347 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
2348 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
2353 This indicates that substitutes from @code{hydra.gnu.org} are usable and
2354 will be downloaded, when possible, for future builds.
2356 @cindex substitutes, how to disable
2357 The substitute mechanism can be disabled globally by running
2358 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
2359 guix-daemon}). It can also be disabled temporarily by passing the
2360 @code{--no-substitutes} option to @command{guix package}, @command{guix
2361 build}, and other command-line tools.
2363 @node Substitute Authentication
2364 @subsection Substitute Authentication
2366 @cindex digital signatures
2367 Guix detects and raises an error when attempting to use a substitute
2368 that has been tampered with. Likewise, it ignores substitutes that are
2369 not signed, or that are not signed by one of the keys listed in the ACL.
2371 There is one exception though: if an unauthorized server provides
2372 substitutes that are @emph{bit-for-bit identical} to those provided by
2373 an authorized server, then the unauthorized server becomes eligible for
2374 downloads. For example, assume we have chosen two substitute servers
2378 --substitute-urls="https://a.example.org https://b.example.org"
2382 @cindex reproducible builds
2383 If the ACL contains only the key for @code{b.example.org}, and if
2384 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
2385 then Guix will download substitutes from @code{a.example.org} because it
2386 comes first in the list and can be considered a mirror of
2387 @code{b.example.org}. In practice, independent build machines usually
2388 produce the same binaries, thanks to bit-reproducible builds (see
2391 When using HTTPS, the server's X.509 certificate is @emph{not} validated
2392 (in other words, the server is not authenticated), contrary to what
2393 HTTPS clients such as Web browsers usually do. This is because Guix
2394 authenticates substitute information itself, as explained above, which
2395 is what we care about (whereas X.509 certificates are about
2396 authenticating bindings between domain names and public keys.)
2398 @node Proxy Settings
2399 @subsection Proxy Settings
2402 Substitutes are downloaded over HTTP or HTTPS.
2403 The @code{http_proxy} environment
2404 variable can be set in the environment of @command{guix-daemon} and is
2405 honored for downloads of substitutes. Note that the value of
2406 @code{http_proxy} in the environment where @command{guix build},
2407 @command{guix package}, and other client commands are run has
2408 @emph{absolutely no effect}.
2410 @node Substitution Failure
2411 @subsection Substitution Failure
2413 Even when a substitute for a derivation is available, sometimes the
2414 substitution attempt will fail. This can happen for a variety of
2415 reasons: the substitute server might be offline, the substitute may
2416 recently have been deleted, the connection might have been interrupted,
2419 When substitutes are enabled and a substitute for a derivation is
2420 available, but the substitution attempt fails, Guix will attempt to
2421 build the derivation locally depending on whether or not
2422 @code{--fallback} was given (@pxref{fallback-option,, common build
2423 option @code{--fallback}}). Specifically, if @code{--fallback} was
2424 omitted, then no local build will be performed, and the derivation is
2425 considered to have failed. However, if @code{--fallback} was given,
2426 then Guix will attempt to build the derivation locally, and the success
2427 or failure of the derivation depends on the success or failure of the
2428 local build. Note that when substitutes are disabled or no substitute
2429 is available for the derivation in question, a local build will
2430 @emph{always} be performed, regardless of whether or not
2431 @code{--fallback} was given.
2433 To get an idea of how many substitutes are available right now, you can
2434 try running the @command{guix weather} command (@pxref{Invoking guix
2435 weather}). This command provides statistics on the substitutes provided
2438 @node On Trusting Binaries
2439 @subsection On Trusting Binaries
2441 @cindex trust, of pre-built binaries
2442 Today, each individual's control over their own computing is at the
2443 mercy of institutions, corporations, and groups with enough power and
2444 determination to subvert the computing infrastructure and exploit its
2445 weaknesses. While using @code{hydra.gnu.org} substitutes can be
2446 convenient, we encourage users to also build on their own, or even run
2447 their own build farm, such that @code{hydra.gnu.org} is less of an
2448 interesting target. One way to help is by publishing the software you
2449 build using @command{guix publish} so that others have one more choice
2450 of server to download substitutes from (@pxref{Invoking guix publish}).
2452 Guix has the foundations to maximize build reproducibility
2453 (@pxref{Features}). In most cases, independent builds of a given
2454 package or derivation should yield bit-identical results. Thus, through
2455 a diverse set of independent package builds, we can strengthen the
2456 integrity of our systems. The @command{guix challenge} command aims to
2457 help users assess substitute servers, and to assist developers in
2458 finding out about non-deterministic package builds (@pxref{Invoking guix
2459 challenge}). Similarly, the @option{--check} option of @command{guix
2460 build} allows users to check whether previously-installed substitutes
2461 are genuine by rebuilding them locally (@pxref{build-check,
2462 @command{guix build --check}}).
2464 In the future, we want Guix to have support to publish and retrieve
2465 binaries to/from other users, in a peer-to-peer fashion. If you would
2466 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
2468 @node Packages with Multiple Outputs
2469 @section Packages with Multiple Outputs
2471 @cindex multiple-output packages
2472 @cindex package outputs
2475 Often, packages defined in Guix have a single @dfn{output}---i.e., the
2476 source package leads to exactly one directory in the store. When running
2477 @command{guix package -i glibc}, one installs the default output of the
2478 GNU libc package; the default output is called @code{out}, but its name
2479 can be omitted as shown in this command. In this particular case, the
2480 default output of @code{glibc} contains all the C header files, shared
2481 libraries, static libraries, Info documentation, and other supporting
2484 Sometimes it is more appropriate to separate the various types of files
2485 produced from a single source package into separate outputs. For
2486 instance, the GLib C library (used by GTK+ and related packages)
2487 installs more than 20 MiB of reference documentation as HTML pages.
2488 To save space for users who do not need it, the documentation goes to a
2489 separate output, called @code{doc}. To install the main GLib output,
2490 which contains everything but the documentation, one would run:
2493 guix package -i glib
2496 @cindex documentation
2497 The command to install its documentation is:
2500 guix package -i glib:doc
2503 Some packages install programs with different ``dependency footprints''.
2504 For instance, the WordNet package installs both command-line tools and
2505 graphical user interfaces (GUIs). The former depend solely on the C
2506 library, whereas the latter depend on Tcl/Tk and the underlying X
2507 libraries. In this case, we leave the command-line tools in the default
2508 output, whereas the GUIs are in a separate output. This allows users
2509 who do not need the GUIs to save space. The @command{guix size} command
2510 can help find out about such situations (@pxref{Invoking guix size}).
2511 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
2513 There are several such multiple-output packages in the GNU distribution.
2514 Other conventional output names include @code{lib} for libraries and
2515 possibly header files, @code{bin} for stand-alone programs, and
2516 @code{debug} for debugging information (@pxref{Installing Debugging
2517 Files}). The outputs of a packages are listed in the third column of
2518 the output of @command{guix package --list-available} (@pxref{Invoking
2522 @node Invoking guix gc
2523 @section Invoking @command{guix gc}
2525 @cindex garbage collector
2527 Packages that are installed, but not used, may be @dfn{garbage-collected}.
2528 The @command{guix gc} command allows users to explicitly run the garbage
2529 collector to reclaim space from the @file{/gnu/store} directory. It is
2530 the @emph{only} way to remove files from @file{/gnu/store}---removing
2531 files or directories manually may break it beyond repair!
2534 @cindex garbage collector roots
2535 The garbage collector has a set of known @dfn{roots}: any file under
2536 @file{/gnu/store} reachable from a root is considered @dfn{live} and
2537 cannot be deleted; any other file is considered @dfn{dead} and may be
2538 deleted. The set of garbage collector roots (``GC roots'' for short)
2539 includes default user profiles; by default, the symlinks under
2540 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
2541 added with @command{guix build --root}, for example (@pxref{Invoking
2544 Prior to running @code{guix gc --collect-garbage} to make space, it is
2545 often useful to remove old generations from user profiles; that way, old
2546 package builds referenced by those generations can be reclaimed. This
2547 is achieved by running @code{guix package --delete-generations}
2548 (@pxref{Invoking guix package}).
2550 Our recommendation is to run a garbage collection periodically, or when
2551 you are short on disk space. For instance, to guarantee that at least
2552 5@tie{}GB are available on your disk, simply run:
2558 It is perfectly safe to run as a non-interactive periodic job
2559 (@pxref{Scheduled Job Execution}, for how to set up such a job on
2560 GuixSD). Running @command{guix gc} with no arguments will collect as
2561 much garbage as it can, but that is often inconvenient: you may find
2562 yourself having to rebuild or re-download software that is ``dead'' from
2563 the GC viewpoint but that is necessary to build other pieces of
2564 software---e.g., the compiler tool chain.
2566 The @command{guix gc} command has three modes of operation: it can be
2567 used to garbage-collect any dead files (the default), to delete specific
2568 files (the @code{--delete} option), to print garbage-collector
2569 information, or for more advanced queries. The garbage collection
2570 options are as follows:
2573 @item --collect-garbage[=@var{min}]
2574 @itemx -C [@var{min}]
2575 Collect garbage---i.e., unreachable @file{/gnu/store} files and
2576 sub-directories. This is the default operation when no option is
2579 When @var{min} is given, stop once @var{min} bytes have been collected.
2580 @var{min} may be a number of bytes, or it may include a unit as a
2581 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
2582 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
2584 When @var{min} is omitted, collect all the garbage.
2586 @item --free-space=@var{free}
2587 @itemx -F @var{free}
2588 Collect garbage until @var{free} space is available under
2589 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
2590 as @code{500MiB}, as described above.
2592 When @var{free} or more is already available in @file{/gnu/store}, do
2593 nothing and exit immediately.
2597 Attempt to delete all the store files and directories specified as
2598 arguments. This fails if some of the files are not in the store, or if
2599 they are still live.
2601 @item --list-failures
2602 List store items corresponding to cached build failures.
2604 This prints nothing unless the daemon was started with
2605 @option{--cache-failures} (@pxref{Invoking guix-daemon,
2606 @option{--cache-failures}}).
2608 @item --clear-failures
2609 Remove the specified store items from the failed-build cache.
2611 Again, this option only makes sense when the daemon is started with
2612 @option{--cache-failures}. Otherwise, it does nothing.
2615 Show the list of dead files and directories still present in the
2616 store---i.e., files and directories no longer reachable from any root.
2619 Show the list of live store files and directories.
2623 In addition, the references among existing store files can be queried:
2629 @cindex package dependencies
2630 List the references (respectively, the referrers) of store files given
2636 List the requisites of the store files passed as arguments. Requisites
2637 include the store files themselves, their references, and the references
2638 of these, recursively. In other words, the returned list is the
2639 @dfn{transitive closure} of the store files.
2641 @xref{Invoking guix size}, for a tool to profile the size of the closure
2642 of an element. @xref{Invoking guix graph}, for a tool to visualize
2643 the graph of references.
2647 Lastly, the following options allow you to check the integrity of the
2648 store and to control disk usage.
2652 @item --verify[=@var{options}]
2653 @cindex integrity, of the store
2654 @cindex integrity checking
2655 Verify the integrity of the store.
2657 By default, make sure that all the store items marked as valid in the
2658 database of the daemon actually exist in @file{/gnu/store}.
2660 When provided, @var{options} must be a comma-separated list containing one
2661 or more of @code{contents} and @code{repair}.
2663 When passing @option{--verify=contents}, the daemon computes the
2664 content hash of each store item and compares it against its hash in the
2665 database. Hash mismatches are reported as data corruptions. Because it
2666 traverses @emph{all the files in the store}, this command can take a
2667 long time, especially on systems with a slow disk drive.
2669 @cindex repairing the store
2670 @cindex corruption, recovering from
2671 Using @option{--verify=repair} or @option{--verify=contents,repair}
2672 causes the daemon to try to repair corrupt store items by fetching
2673 substitutes for them (@pxref{Substitutes}). Because repairing is not
2674 atomic, and thus potentially dangerous, it is available only to the
2675 system administrator. A lightweight alternative, when you know exactly
2676 which items in the store are corrupt, is @command{guix build --repair}
2677 (@pxref{Invoking guix build}).
2680 @cindex deduplication
2681 Optimize the store by hard-linking identical files---this is
2682 @dfn{deduplication}.
2684 The daemon performs deduplication after each successful build or archive
2685 import, unless it was started with @code{--disable-deduplication}
2686 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
2687 this option is primarily useful when the daemon was running with
2688 @code{--disable-deduplication}.
2692 @node Invoking guix pull
2693 @section Invoking @command{guix pull}
2695 @cindex upgrading Guix
2696 @cindex updating Guix
2697 @cindex @command{guix pull}
2699 Packages are installed or upgraded to the latest version available in
2700 the distribution currently available on your local machine. To update
2701 that distribution, along with the Guix tools, you must run @command{guix
2702 pull}: the command downloads the latest Guix source code and package
2703 descriptions, and deploys it. Source code is downloaded from a
2704 @uref{https://git-scm.com, Git} repository.
2706 On completion, @command{guix package} will use packages and package
2707 versions from this just-retrieved copy of Guix. Not only that, but all
2708 the Guix commands and Scheme modules will also be taken from that latest
2709 version. New @command{guix} sub-commands added by the update also
2712 Any user can update their Guix copy using @command{guix pull}, and the
2713 effect is limited to the user who run @command{guix pull}. For
2714 instance, when user @code{root} runs @command{guix pull}, this has no
2715 effect on the version of Guix that user @code{alice} sees, and vice
2716 versa@footnote{Under the hood, @command{guix pull} updates the
2717 @file{~/.config/guix/latest} symbolic link to point to the latest Guix,
2718 and the @command{guix} command loads code from there. Currently, the
2719 only way to roll back an invocation of @command{guix pull} is to
2720 manually update this symlink to point to the previous Guix.}.
2722 The @command{guix pull} command is usually invoked with no arguments,
2723 but it supports the following options:
2727 Produce verbose output, writing build logs to the standard error output.
2729 @item --url=@var{url}
2730 Download Guix from the Git repository at @var{url}.
2732 @vindex GUIX_PULL_URL
2733 By default, the source is taken from its canonical Git repository at
2734 @code{gnu.org}, for the stable branch of Guix. To use a different source,
2735 set the @code{GUIX_PULL_URL} environment variable.
2737 @item --commit=@var{commit}
2738 Deploy @var{commit}, a valid Git commit ID represented as a hexadecimal
2741 @item --branch=@var{branch}
2742 Deploy the tip of @var{branch}, the name of a Git branch available on
2743 the repository at @var{url}.
2746 Use the bootstrap Guile to build the latest Guix. This option is only
2747 useful to Guix developers.
2750 In addition, @command{guix pull} supports all the common build options
2751 (@pxref{Common Build Options}).
2753 @node Invoking guix pack
2754 @section Invoking @command{guix pack}
2756 Occasionally you want to pass software to people who are not (yet!)
2757 lucky enough to be using Guix. You'd tell them to run @command{guix
2758 package -i @var{something}}, but that's not possible in this case. This
2759 is where @command{guix pack} comes in.
2762 If you are looking for ways to exchange binaries among machines that
2763 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
2764 publish}, and @ref{Invoking guix archive}.
2769 @cindex application bundle
2770 @cindex software bundle
2771 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
2772 @dfn{software bundle}: it creates a tarball or some other archive
2773 containing the binaries of the software you're interested in, and all
2774 its dependencies. The resulting archive can be used on any machine that
2775 does not have Guix, and people can run the exact same binaries as those
2776 you have with Guix. The pack itself is created in a bit-reproducible
2777 fashion, so anyone can verify that it really contains the build results
2778 that you pretend to be shipping.
2780 For example, to create a bundle containing Guile, Emacs, Geiser, and all
2781 their dependencies, you can run:
2784 $ guix pack guile emacs geiser
2786 /gnu/store/@dots{}-pack.tar.gz
2789 The result here is a tarball containing a @file{/gnu/store} directory
2790 with all the relevant packages. The resulting tarball contains a
2791 @dfn{profile} with the three packages of interest; the profile is the
2792 same as would be created by @command{guix package -i}. It is this
2793 mechanism that is used to create Guix's own standalone binary tarball
2794 (@pxref{Binary Installation}).
2796 Users of this pack would have to run
2797 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
2798 find inconvenient. To work around it, you can create, say, a
2799 @file{/opt/gnu/bin} symlink to the profile:
2802 guix pack -S /opt/gnu/bin=bin guile emacs geiser
2806 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
2808 Alternatively, you can produce a pack in the Docker image format using
2809 the following command:
2812 guix pack -f docker guile emacs geiser
2816 The result is a tarball that can be passed to the @command{docker load}
2818 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
2819 documentation} for more information.
2821 Several command-line options allow you to customize your pack:
2824 @item --format=@var{format}
2825 @itemx -f @var{format}
2826 Produce a pack in the given @var{format}.
2828 The available formats are:
2832 This is the default format. It produces a tarball containing all the
2833 specified binaries and symlinks.
2836 This produces a tarball that follows the
2837 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
2838 Docker Image Specification}.
2841 @item --expression=@var{expr}
2842 @itemx -e @var{expr}
2843 Consider the package @var{expr} evaluates to.
2845 This has the same purpose as the same-named option in @command{guix
2846 build} (@pxref{Additional Build Options, @code{--expression} in
2847 @command{guix build}}).
2849 @item --manifest=@var{file}
2850 @itemx -m @var{file}
2851 Use the packages contained in the manifest object returned by the Scheme
2854 This has a similar purpose as the same-named option in @command{guix
2855 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
2856 same manifest files. It allows you to define a collection of packages
2857 once and use it both for creating profiles and for creating archives
2858 for use on machines that do not have Guix installed. Note that you can
2859 specify @emph{either} a manifest file @emph{or} a list of packages,
2862 @item --system=@var{system}
2863 @itemx -s @var{system}
2864 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
2865 the system type of the build host.
2867 @item --target=@var{triplet}
2868 @cindex cross-compilation
2869 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
2870 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
2871 configuration triplets,, autoconf, Autoconf}).
2873 @item --compression=@var{tool}
2874 @itemx -C @var{tool}
2875 Compress the resulting tarball using @var{tool}---one of @code{gzip},
2876 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
2878 @item --symlink=@var{spec}
2879 @itemx -S @var{spec}
2880 Add the symlinks specified by @var{spec} to the pack. This option can
2881 appear several times.
2883 @var{spec} has the form @code{@var{source}=@var{target}}, where
2884 @var{source} is the symlink that will be created and @var{target} is the
2887 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
2888 symlink pointing to the @file{bin} sub-directory of the profile.
2890 @item --localstatedir
2891 Include the ``local state directory'', @file{/var/guix}, in the
2894 @file{/var/guix} contains the store database (@pxref{The Store}) as well
2895 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
2896 the pack means that the store is ``complete'' and manageable by Guix;
2897 not providing it pack means that the store is ``dead'': items cannot be
2898 added to it or removed from it after extraction of the pack.
2900 One use case for this is the Guix self-contained binary tarball
2901 (@pxref{Binary Installation}).
2904 In addition, @command{guix pack} supports all the common build options
2905 (@pxref{Common Build Options}) and all the package transformation
2906 options (@pxref{Package Transformation Options}).
2909 @node Invoking guix archive
2910 @section Invoking @command{guix archive}
2912 @cindex @command{guix archive}
2914 The @command{guix archive} command allows users to @dfn{export} files
2915 from the store into a single archive, and to later @dfn{import} them on
2916 a machine that runs Guix.
2917 In particular, it allows store files to be transferred from one machine
2918 to the store on another machine.
2921 If you're looking for a way to produce archives in a format suitable for
2922 tools other than Guix, @pxref{Invoking guix pack}.
2925 @cindex exporting store items
2926 To export store files as an archive to standard output, run:
2929 guix archive --export @var{options} @var{specifications}...
2932 @var{specifications} may be either store file names or package
2933 specifications, as for @command{guix package} (@pxref{Invoking guix
2934 package}). For instance, the following command creates an archive
2935 containing the @code{gui} output of the @code{git} package and the main
2936 output of @code{emacs}:
2939 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
2942 If the specified packages are not built yet, @command{guix archive}
2943 automatically builds them. The build process may be controlled with the
2944 common build options (@pxref{Common Build Options}).
2946 To transfer the @code{emacs} package to a machine connected over SSH,
2950 guix archive --export -r emacs | ssh the-machine guix archive --import
2954 Similarly, a complete user profile may be transferred from one machine
2955 to another like this:
2958 guix archive --export -r $(readlink -f ~/.guix-profile) | \
2959 ssh the-machine guix-archive --import
2963 However, note that, in both examples, all of @code{emacs} and the
2964 profile as well as all of their dependencies are transferred (due to
2965 @code{-r}), regardless of what is already available in the store on the
2966 target machine. The @code{--missing} option can help figure out which
2967 items are missing from the target store. The @command{guix copy}
2968 command simplifies and optimizes this whole process, so this is probably
2969 what you should use in this case (@pxref{Invoking guix copy}).
2971 @cindex nar, archive format
2972 @cindex normalized archive (nar)
2973 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
2974 comparable in spirit to `tar', but with differences
2975 that make it more appropriate for our purposes. First, rather than
2976 recording all Unix metadata for each file, the nar format only mentions
2977 the file type (regular, directory, or symbolic link); Unix permissions
2978 and owner/group are dismissed. Second, the order in which directory
2979 entries are stored always follows the order of file names according to
2980 the C locale collation order. This makes archive production fully
2983 When exporting, the daemon digitally signs the contents of the archive,
2984 and that digital signature is appended. When importing, the daemon
2985 verifies the signature and rejects the import in case of an invalid
2986 signature or if the signing key is not authorized.
2987 @c FIXME: Add xref to daemon doc about signatures.
2989 The main options are:
2993 Export the specified store files or packages (see below.) Write the
2994 resulting archive to the standard output.
2996 Dependencies are @emph{not} included in the output, unless
2997 @code{--recursive} is passed.
3001 When combined with @code{--export}, this instructs @command{guix
3002 archive} to include dependencies of the given items in the archive.
3003 Thus, the resulting archive is self-contained: it contains the closure
3004 of the exported store items.
3007 Read an archive from the standard input, and import the files listed
3008 therein into the store. Abort if the archive has an invalid digital
3009 signature, or if it is signed by a public key not among the authorized
3010 keys (see @code{--authorize} below.)
3013 Read a list of store file names from the standard input, one per line,
3014 and write on the standard output the subset of these files missing from
3017 @item --generate-key[=@var{parameters}]
3018 @cindex signing, archives
3019 Generate a new key pair for the daemon. This is a prerequisite before
3020 archives can be exported with @code{--export}. Note that this operation
3021 usually takes time, because it needs to gather enough entropy to
3022 generate the key pair.
3024 The generated key pair is typically stored under @file{/etc/guix}, in
3025 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
3026 key, which must be kept secret.) When @var{parameters} is omitted,
3027 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
3028 versions before 1.6.0, it is a 4096-bit RSA key.
3029 Alternatively, @var{parameters} can specify
3030 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
3031 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
3032 Libgcrypt Reference Manual}).
3035 @cindex authorizing, archives
3036 Authorize imports signed by the public key passed on standard input.
3037 The public key must be in ``s-expression advanced format''---i.e., the
3038 same format as the @file{signing-key.pub} file.
3040 The list of authorized keys is kept in the human-editable file
3041 @file{/etc/guix/acl}. The file contains
3042 @url{http://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
3043 s-expressions''} and is structured as an access-control list in the
3044 @url{http://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
3047 @item --extract=@var{directory}
3048 @itemx -x @var{directory}
3049 Read a single-item archive as served by substitute servers
3050 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
3051 low-level operation needed in only very narrow use cases; see below.
3053 For example, the following command extracts the substitute for Emacs
3054 served by @code{hydra.gnu.org} to @file{/tmp/emacs}:
3058 https://hydra.gnu.org/nar/@dots{}-emacs-24.5 \
3059 | bunzip2 | guix archive -x /tmp/emacs
3062 Single-item archives are different from multiple-item archives produced
3063 by @command{guix archive --export}; they contain a single store item,
3064 and they do @emph{not} embed a signature. Thus this operation does
3065 @emph{no} signature verification and its output should be considered
3068 The primary purpose of this operation is to facilitate inspection of
3069 archive contents coming from possibly untrusted substitute servers.
3073 @c *********************************************************************
3074 @node Programming Interface
3075 @chapter Programming Interface
3077 GNU Guix provides several Scheme programming interfaces (APIs) to
3078 define, build, and query packages. The first interface allows users to
3079 write high-level package definitions. These definitions refer to
3080 familiar packaging concepts, such as the name and version of a package,
3081 its build system, and its dependencies. These definitions can then be
3082 turned into concrete build actions.
3084 Build actions are performed by the Guix daemon, on behalf of users. In a
3085 standard setup, the daemon has write access to the store---the
3086 @file{/gnu/store} directory---whereas users do not. The recommended
3087 setup also has the daemon perform builds in chroots, under a specific
3088 build users, to minimize interference with the rest of the system.
3091 Lower-level APIs are available to interact with the daemon and the
3092 store. To instruct the daemon to perform a build action, users actually
3093 provide it with a @dfn{derivation}. A derivation is a low-level
3094 representation of the build actions to be taken, and the environment in
3095 which they should occur---derivations are to package definitions what
3096 assembly is to C programs. The term ``derivation'' comes from the fact
3097 that build results @emph{derive} from them.
3099 This chapter describes all these APIs in turn, starting from high-level
3100 package definitions.
3103 * Defining Packages:: Defining new packages.
3104 * Build Systems:: Specifying how packages are built.
3105 * The Store:: Manipulating the package store.
3106 * Derivations:: Low-level interface to package derivations.
3107 * The Store Monad:: Purely functional interface to the store.
3108 * G-Expressions:: Manipulating build expressions.
3111 @node Defining Packages
3112 @section Defining Packages
3114 The high-level interface to package definitions is implemented in the
3115 @code{(guix packages)} and @code{(guix build-system)} modules. As an
3116 example, the package definition, or @dfn{recipe}, for the GNU Hello
3117 package looks like this:
3120 (define-module (gnu packages hello)
3121 #:use-module (guix packages)
3122 #:use-module (guix download)
3123 #:use-module (guix build-system gnu)
3124 #:use-module (guix licenses)
3125 #:use-module (gnu packages gawk))
3127 (define-public hello
3133 (uri (string-append "mirror://gnu/hello/hello-" version
3137 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
3138 (build-system gnu-build-system)
3139 (arguments '(#:configure-flags '("--enable-silent-rules")))
3140 (inputs `(("gawk" ,gawk)))
3141 (synopsis "Hello, GNU world: An example GNU package")
3142 (description "Guess what GNU Hello prints!")
3143 (home-page "http://www.gnu.org/software/hello/")
3148 Without being a Scheme expert, the reader may have guessed the meaning
3149 of the various fields here. This expression binds the variable
3150 @code{hello} to a @code{<package>} object, which is essentially a record
3151 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
3152 This package object can be inspected using procedures found in the
3153 @code{(guix packages)} module; for instance, @code{(package-name hello)}
3154 returns---surprise!---@code{"hello"}.
3156 With luck, you may be able to import part or all of the definition of
3157 the package you are interested in from another repository, using the
3158 @code{guix import} command (@pxref{Invoking guix import}).
3160 In the example above, @var{hello} is defined in a module of its own,
3161 @code{(gnu packages hello)}. Technically, this is not strictly
3162 necessary, but it is convenient to do so: all the packages defined in
3163 modules under @code{(gnu packages @dots{})} are automatically known to
3164 the command-line tools (@pxref{Package Modules}).
3166 There are a few points worth noting in the above package definition:
3170 The @code{source} field of the package is an @code{<origin>} object
3171 (@pxref{origin Reference}, for the complete reference).
3172 Here, the @code{url-fetch} method from @code{(guix download)} is used,
3173 meaning that the source is a file to be downloaded over FTP or HTTP.
3175 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
3176 the GNU mirrors defined in @code{(guix download)}.
3178 The @code{sha256} field specifies the expected SHA256 hash of the file
3179 being downloaded. It is mandatory, and allows Guix to check the
3180 integrity of the file. The @code{(base32 @dots{})} form introduces the
3181 base32 representation of the hash. You can obtain this information with
3182 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
3183 hash} (@pxref{Invoking guix hash}).
3186 When needed, the @code{origin} form can also have a @code{patches} field
3187 listing patches to be applied, and a @code{snippet} field giving a
3188 Scheme expression to modify the source code.
3191 @cindex GNU Build System
3192 The @code{build-system} field specifies the procedure to build the
3193 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
3194 represents the familiar GNU Build System, where packages may be
3195 configured, built, and installed with the usual @code{./configure &&
3196 make && make check && make install} command sequence.
3199 The @code{arguments} field specifies options for the build system
3200 (@pxref{Build Systems}). Here it is interpreted by
3201 @var{gnu-build-system} as a request run @file{configure} with the
3202 @code{--enable-silent-rules} flag.
3208 What about these quote (@code{'}) characters? They are Scheme syntax to
3209 introduce a literal list; @code{'} is synonymous with @code{quote}.
3210 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
3211 for details. Here the value of the @code{arguments} field is a list of
3212 arguments passed to the build system down the road, as with @code{apply}
3213 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
3216 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
3217 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
3218 @code{#:configure-flags} is a keyword used to pass a keyword argument
3219 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
3223 The @code{inputs} field specifies inputs to the build process---i.e.,
3224 build-time or run-time dependencies of the package. Here, we define an
3225 input called @code{"gawk"} whose value is that of the @var{gawk}
3226 variable; @var{gawk} is itself bound to a @code{<package>} object.
3228 @cindex backquote (quasiquote)
3231 @cindex comma (unquote)
3235 @findex unquote-splicing
3236 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
3237 us to introduce a literal list in the @code{inputs} field, while
3238 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
3239 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
3242 Note that GCC, Coreutils, Bash, and other essential tools do not need to
3243 be specified as inputs here. Instead, @var{gnu-build-system} takes care
3244 of ensuring that they are present (@pxref{Build Systems}).
3246 However, any other dependencies need to be specified in the
3247 @code{inputs} field. Any dependency not specified here will simply be
3248 unavailable to the build process, possibly leading to a build failure.
3251 @xref{package Reference}, for a full description of possible fields.
3253 Once a package definition is in place, the
3254 package may actually be built using the @code{guix build} command-line
3255 tool (@pxref{Invoking guix build}), troubleshooting any build failures
3256 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
3257 package definition using the @command{guix edit} command
3258 (@pxref{Invoking guix edit}).
3259 @xref{Packaging Guidelines}, for
3260 more information on how to test package definitions, and
3261 @ref{Invoking guix lint}, for information on how to check a definition
3262 for style conformance.
3263 @vindex GUIX_PACKAGE_PATH
3264 Lastly, @pxref{Package Modules}, for information
3265 on how to extend the distribution by adding your own package definitions
3266 to @code{GUIX_PACKAGE_PATH}.
3268 Finally, updating the package definition to a new upstream version
3269 can be partly automated by the @command{guix refresh} command
3270 (@pxref{Invoking guix refresh}).
3272 Behind the scenes, a derivation corresponding to the @code{<package>}
3273 object is first computed by the @code{package-derivation} procedure.
3274 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
3275 The build actions it prescribes may then be realized by using the
3276 @code{build-derivations} procedure (@pxref{The Store}).
3278 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
3279 Return the @code{<derivation>} object of @var{package} for @var{system}
3280 (@pxref{Derivations}).
3282 @var{package} must be a valid @code{<package>} object, and @var{system}
3283 must be a string denoting the target system type---e.g.,
3284 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
3285 must be a connection to the daemon, which operates on the store
3286 (@pxref{The Store}).
3290 @cindex cross-compilation
3291 Similarly, it is possible to compute a derivation that cross-builds a
3292 package for some other system:
3294 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
3295 @var{package} @var{target} [@var{system}]
3296 Return the @code{<derivation>} object of @var{package} cross-built from
3297 @var{system} to @var{target}.
3299 @var{target} must be a valid GNU triplet denoting the target hardware
3300 and operating system, such as @code{"mips64el-linux-gnu"}
3301 (@pxref{Configuration Names, GNU configuration triplets,, configure, GNU
3302 Configure and Build System}).
3305 @cindex package transformations
3306 @cindex input rewriting
3307 @cindex dependency tree rewriting
3308 Packages can be manipulated in arbitrary ways. An example of a useful
3309 transformation is @dfn{input rewriting}, whereby the dependency tree of
3310 a package is rewritten by replacing specific inputs by others:
3312 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
3313 [@var{rewrite-name}]
3314 Return a procedure that, when passed a package, replaces its direct and
3315 indirect dependencies (but not its implicit inputs) according to
3316 @var{replacements}. @var{replacements} is a list of package pairs; the
3317 first element of each pair is the package to replace, and the second one
3320 Optionally, @var{rewrite-name} is a one-argument procedure that takes
3321 the name of a package and returns its new name after rewrite.
3325 Consider this example:
3328 (define libressl-instead-of-openssl
3329 ;; This is a procedure to replace OPENSSL by LIBRESSL,
3331 (package-input-rewriting `((,openssl . ,libressl))))
3333 (define git-with-libressl
3334 (libressl-instead-of-openssl git))
3338 Here we first define a rewriting procedure that replaces @var{openssl}
3339 with @var{libressl}. Then we use it to define a @dfn{variant} of the
3340 @var{git} package that uses @var{libressl} instead of @var{openssl}.
3341 This is exactly what the @option{--with-input} command-line option does
3342 (@pxref{Package Transformation Options, @option{--with-input}}).
3344 A more generic procedure to rewrite a package dependency graph is
3345 @code{package-mapping}: it supports arbitrary changes to nodes in the
3348 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
3349 Return a procedure that, given a package, applies @var{proc} to all the packages
3350 depended on and returns the resulting package. The procedure stops recursion
3351 when @var{cut?} returns true for a given package.
3355 * package Reference :: The package data type.
3356 * origin Reference:: The origin data type.
3360 @node package Reference
3361 @subsection @code{package} Reference
3363 This section summarizes all the options available in @code{package}
3364 declarations (@pxref{Defining Packages}).
3366 @deftp {Data Type} package
3367 This is the data type representing a package recipe.
3371 The name of the package, as a string.
3373 @item @code{version}
3374 The version of the package, as a string.
3377 An object telling how the source code for the package should be
3378 acquired. Most of the time, this is an @code{origin} object, which
3379 denotes a file fetched from the Internet (@pxref{origin Reference}). It
3380 can also be any other ``file-like'' object such as a @code{local-file},
3381 which denotes a file from the local file system (@pxref{G-Expressions,
3382 @code{local-file}}).
3384 @item @code{build-system}
3385 The build system that should be used to build the package (@pxref{Build
3388 @item @code{arguments} (default: @code{'()})
3389 The arguments that should be passed to the build system. This is a
3390 list, typically containing sequential keyword-value pairs.
3392 @item @code{inputs} (default: @code{'()})
3393 @itemx @code{native-inputs} (default: @code{'()})
3394 @itemx @code{propagated-inputs} (default: @code{'()})
3395 @cindex inputs, of packages
3396 These fields list dependencies of the package. Each one is a list of
3397 tuples, where each tuple has a label for the input (a string) as its
3398 first element, a package, origin, or derivation as its second element,
3399 and optionally the name of the output thereof that should be used, which
3400 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
3401 more on package outputs). For example, the list below specifies three
3405 `(("libffi" ,libffi)
3406 ("libunistring" ,libunistring)
3407 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
3410 @cindex cross compilation, package dependencies
3411 The distinction between @code{native-inputs} and @code{inputs} is
3412 necessary when considering cross-compilation. When cross-compiling,
3413 dependencies listed in @code{inputs} are built for the @emph{target}
3414 architecture; conversely, dependencies listed in @code{native-inputs}
3415 are built for the architecture of the @emph{build} machine.
3417 @code{native-inputs} is typically used to list tools needed at
3418 build time, but not at run time, such as Autoconf, Automake, pkg-config,
3419 Gettext, or Bison. @command{guix lint} can report likely mistakes in
3420 this area (@pxref{Invoking guix lint}).
3422 @anchor{package-propagated-inputs}
3423 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
3424 specified packages will be automatically installed alongside the package
3425 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
3426 package}}, for information on how @command{guix package} deals with
3429 For example this is necessary when a C/C++ library needs headers of
3430 another library to compile, or when a pkg-config file refers to another
3431 one @i{via} its @code{Requires} field.
3433 Another example where @code{propagated-inputs} is useful is for languages
3434 that lack a facility to record the run-time search path akin to the
3435 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
3436 more. To ensure that libraries written in those languages can find
3437 library code they depend on at run time, run-time dependencies must be
3438 listed in @code{propagated-inputs} rather than @code{inputs}.
3440 @item @code{self-native-input?} (default: @code{#f})
3441 This is a Boolean field telling whether the package should use itself as
3442 a native input when cross-compiling.
3444 @item @code{outputs} (default: @code{'("out")})
3445 The list of output names of the package. @xref{Packages with Multiple
3446 Outputs}, for typical uses of additional outputs.
3448 @item @code{native-search-paths} (default: @code{'()})
3449 @itemx @code{search-paths} (default: @code{'()})
3450 A list of @code{search-path-specification} objects describing
3451 search-path environment variables honored by the package.
3453 @item @code{replacement} (default: @code{#f})
3454 This must be either @code{#f} or a package object that will be used as a
3455 @dfn{replacement} for this package. @xref{Security Updates, grafts},
3458 @item @code{synopsis}
3459 A one-line description of the package.
3461 @item @code{description}
3462 A more elaborate description of the package.
3464 @item @code{license}
3465 @cindex license, of packages
3466 The license of the package; a value from @code{(guix licenses)},
3467 or a list of such values.
3469 @item @code{home-page}
3470 The URL to the home-page of the package, as a string.
3472 @item @code{supported-systems} (default: @var{%supported-systems})
3473 The list of systems supported by the package, as strings of the form
3474 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
3476 @item @code{maintainers} (default: @code{'()})
3477 The list of maintainers of the package, as @code{maintainer} objects.
3479 @item @code{location} (default: source location of the @code{package} form)
3480 The source location of the package. It is useful to override this when
3481 inheriting from another package, in which case this field is not
3482 automatically corrected.
3487 @node origin Reference
3488 @subsection @code{origin} Reference
3490 This section summarizes all the options available in @code{origin}
3491 declarations (@pxref{Defining Packages}).
3493 @deftp {Data Type} origin
3494 This is the data type representing a source code origin.
3498 An object containing the URI of the source. The object type depends on
3499 the @code{method} (see below). For example, when using the
3500 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
3501 values are: a URL represented as a string, or a list thereof.
3504 A procedure that handles the URI.
3509 @item @var{url-fetch} from @code{(guix download)}
3510 download a file from the HTTP, HTTPS, or FTP URL specified in the
3514 @item @var{git-fetch} from @code{(guix git-download)}
3515 clone the Git version control repository, and check out the revision
3516 specified in the @code{uri} field as a @code{git-reference} object; a
3517 @code{git-reference} looks like this:
3521 (url "git://git.debian.org/git/pkg-shadow/shadow")
3522 (commit "v4.1.5.1"))
3527 A bytevector containing the SHA-256 hash of the source. Typically the
3528 @code{base32} form is used here to generate the bytevector from a
3531 You can obtain this information using @code{guix download}
3532 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
3535 @item @code{file-name} (default: @code{#f})
3536 The file name under which the source code should be saved. When this is
3537 @code{#f}, a sensible default value will be used in most cases. In case
3538 the source is fetched from a URL, the file name from the URL will be
3539 used. For version control checkouts, it is recommended to provide the
3540 file name explicitly because the default is not very descriptive.
3542 @item @code{patches} (default: @code{'()})
3543 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
3544 file-like objects}) pointing to patches to be applied to the source.
3546 This list of patches must be unconditional. In particular, it cannot
3547 depend on the value of @code{%current-system} or
3548 @code{%current-target-system}.
3550 @item @code{snippet} (default: @code{#f})
3551 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
3552 in the source directory. This is a convenient way to modify the source,
3553 sometimes more convenient than a patch.
3555 @item @code{patch-flags} (default: @code{'("-p1")})
3556 A list of command-line flags that should be passed to the @code{patch}
3559 @item @code{patch-inputs} (default: @code{#f})
3560 Input packages or derivations to the patching process. When this is
3561 @code{#f}, the usual set of inputs necessary for patching are provided,
3562 such as GNU@tie{}Patch.
3564 @item @code{modules} (default: @code{'()})
3565 A list of Guile modules that should be loaded during the patching
3566 process and while running the code in the @code{snippet} field.
3568 @item @code{patch-guile} (default: @code{#f})
3569 The Guile package that should be used in the patching process. When
3570 this is @code{#f}, a sensible default is used.
3576 @section Build Systems
3578 @cindex build system
3579 Each package definition specifies a @dfn{build system} and arguments for
3580 that build system (@pxref{Defining Packages}). This @code{build-system}
3581 field represents the build procedure of the package, as well as implicit
3582 dependencies of that build procedure.
3584 Build systems are @code{<build-system>} objects. The interface to
3585 create and manipulate them is provided by the @code{(guix build-system)}
3586 module, and actual build systems are exported by specific modules.
3588 @cindex bag (low-level package representation)
3589 Under the hood, build systems first compile package objects to
3590 @dfn{bags}. A @dfn{bag} is like a package, but with less
3591 ornamentation---in other words, a bag is a lower-level representation of
3592 a package, which includes all the inputs of that package, including some
3593 that were implicitly added by the build system. This intermediate
3594 representation is then compiled to a derivation (@pxref{Derivations}).
3596 Build systems accept an optional list of @dfn{arguments}. In package
3597 definitions, these are passed @i{via} the @code{arguments} field
3598 (@pxref{Defining Packages}). They are typically keyword arguments
3599 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
3600 Guile Reference Manual}). The value of these arguments is usually
3601 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
3602 by the daemon (@pxref{Derivations}).
3604 The main build system is @var{gnu-build-system}, which implements the
3605 standard build procedure for GNU and many other packages. It
3606 is provided by the @code{(guix build-system gnu)} module.
3608 @defvr {Scheme Variable} gnu-build-system
3609 @var{gnu-build-system} represents the GNU Build System, and variants
3610 thereof (@pxref{Configuration, configuration and makefile conventions,,
3611 standards, GNU Coding Standards}).
3613 @cindex build phases
3614 In a nutshell, packages using it are configured, built, and installed with
3615 the usual @code{./configure && make && make check && make install}
3616 command sequence. In practice, a few additional steps are often needed.
3617 All these steps are split up in separate @dfn{phases},
3618 notably@footnote{Please see the @code{(guix build gnu-build-system)}
3619 modules for more details about the build phases.}:
3623 Unpack the source tarball, and change the current directory to the
3624 extracted source tree. If the source is actually a directory, copy it
3625 to the build tree, and enter that directory.
3627 @item patch-source-shebangs
3628 Patch shebangs encountered in source files so they refer to the right
3629 store file names. For instance, this changes @code{#!/bin/sh} to
3630 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
3633 Run the @file{configure} script with a number of default options, such
3634 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
3635 by the @code{#:configure-flags} argument.
3638 Run @code{make} with the list of flags specified with
3639 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
3640 (the default), build with @code{make -j}.
3643 Run @code{make check}, or some other target specified with
3644 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
3645 @code{#:parallel-tests?} argument is true (the default), run @code{make
3649 Run @code{make install} with the flags listed in @code{#:make-flags}.
3651 @item patch-shebangs
3652 Patch shebangs on the installed executable files.
3655 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
3656 is false), copying them to the @code{debug} output when available
3657 (@pxref{Installing Debugging Files}).
3660 @vindex %standard-phases
3661 The build-side module @code{(guix build gnu-build-system)} defines
3662 @var{%standard-phases} as the default list of build phases.
3663 @var{%standard-phases} is a list of symbol/procedure pairs, where the
3664 procedure implements the actual phase.
3666 The list of phases used for a particular package can be changed with the
3667 @code{#:phases} parameter. For instance, passing:
3670 #:phases (modify-phases %standard-phases (delete 'configure))
3673 means that all the phases described above will be used, except the
3674 @code{configure} phase.
3676 In addition, this build system ensures that the ``standard'' environment
3677 for GNU packages is available. This includes tools such as GCC, libc,
3678 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
3679 build-system gnu)} module for a complete list). We call these the
3680 @dfn{implicit inputs} of a package, because package definitions do not
3681 have to mention them.
3684 Other @code{<build-system>} objects are defined to support other
3685 conventions and tools used by free software packages. They inherit most
3686 of @var{gnu-build-system}, and differ mainly in the set of inputs
3687 implicitly added to the build process, and in the list of phases
3688 executed. Some of these build systems are listed below.
3690 @defvr {Scheme Variable} ant-build-system
3691 This variable is exported by @code{(guix build-system ant)}. It
3692 implements the build procedure for Java packages that can be built with
3693 @url{http://ant.apache.org/, Ant build tool}.
3695 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
3696 provided by the @code{icedtea} package to the set of inputs. Different
3697 packages can be specified with the @code{#:ant} and @code{#:jdk}
3698 parameters, respectively.
3700 When the original package does not provide a suitable Ant build file,
3701 the parameter @code{#:jar-name} can be used to generate a minimal Ant
3702 build file @file{build.xml} with tasks to build the specified jar
3703 archive. In this case the parameter @code{#:source-dir} can be used to
3704 specify the source sub-directory, defaulting to ``src''.
3706 The @code{#:main-class} parameter can be used with the minimal ant
3707 buildfile to specify the main class of the resulting jar. This makes the
3708 jar file executable. The @code{#:test-include} parameter can be used to
3709 specify the list of junit tests to run. It defaults to
3710 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
3711 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
3712 because abstract classes cannot be run as tests.
3714 The parameter @code{#:build-target} can be used to specify the Ant task
3715 that should be run during the @code{build} phase. By default the
3716 ``jar'' task will be run.
3720 @defvr {Scheme Variable} asdf-build-system/source
3721 @defvrx {Scheme Variable} asdf-build-system/sbcl
3722 @defvrx {Scheme Variable} asdf-build-system/ecl
3724 These variables, exported by @code{(guix build-system asdf)}, implement
3725 build procedures for Common Lisp packages using
3726 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
3727 definition facility for Common Lisp programs and libraries.
3729 The @code{asdf-build-system/source} system installs the packages in
3730 source form, and can be loaded using any common lisp implementation, via
3731 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
3732 systems in the format which a particular implementation understands.
3733 These build systems can also be used to produce executable programs, or
3734 lisp images which contain a set of packages pre-loaded.
3736 The build system uses naming conventions. For binary packages, the
3737 package name should be prefixed with the lisp implementation, such as
3738 @code{sbcl-} for @code{asdf-build-system/sbcl}.
3740 Additionally, the corresponding source package should be labeled using
3741 the same convention as python packages (see @ref{Python Modules}), using
3742 the @code{cl-} prefix.
3744 For binary packages, each system should be defined as a Guix package.
3745 If one package @code{origin} contains several systems, package variants
3746 can be created in order to build all the systems. Source packages,
3747 which use @code{asdf-build-system/source}, may contain several systems.
3749 In order to create executable programs and images, the build-side
3750 procedures @code{build-program} and @code{build-image} can be used.
3751 They should be called in a build phase after the @code{create-symlinks}
3752 phase, so that the system which was just built can be used within the
3753 resulting image. @code{build-program} requires a list of Common Lisp
3754 expressions to be passed as the @code{#:entry-program} argument.
3756 If the system is not defined within its own @code{.asd} file of the same
3757 name, then the @code{#:asd-file} parameter should be used to specify
3758 which file the system is defined in. Furthermore, if the package
3759 defines a system for its tests in a separate file, it will be loaded
3760 before the tests are run if it is specified by the
3761 @code{#:test-asd-file} parameter. If it is not set, the files
3762 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
3763 and @code{test.asd} will be tried if they exist.
3765 If for some reason the package must be named in a different way than the
3766 naming conventions suggest, the @code{#:asd-system-name} parameter can
3767 be used to specify the name of the system.
3771 @defvr {Scheme Variable} cargo-build-system
3772 @cindex Rust programming language
3773 @cindex Cargo (Rust build system)
3774 This variable is exported by @code{(guix build-system cargo)}. It
3775 supports builds of packages using Cargo, the build tool of the
3776 @uref{https://www.rust-lang.org, Rust programming language}.
3778 In its @code{configure} phase, this build system replaces dependencies
3779 specified in the @file{Carto.toml} file with inputs to the Guix package.
3780 The @code{install} phase installs the binaries, and it also installs the
3781 source code and @file{Cargo.toml} file.
3784 @defvr {Scheme Variable} cmake-build-system
3785 This variable is exported by @code{(guix build-system cmake)}. It
3786 implements the build procedure for packages using the
3787 @url{http://www.cmake.org, CMake build tool}.
3789 It automatically adds the @code{cmake} package to the set of inputs.
3790 Which package is used can be specified with the @code{#:cmake}
3793 The @code{#:configure-flags} parameter is taken as a list of flags
3794 passed to the @command{cmake} command. The @code{#:build-type}
3795 parameter specifies in abstract terms the flags passed to the compiler;
3796 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
3797 debugging information''), which roughly means that code is compiled with
3798 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
3801 @defvr {Scheme Variable} go-build-system
3802 This variable is exported by @code{(guix build-system go)}. It
3803 implements a build procedure for Go packages using the standard
3804 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
3805 Go build mechanisms}.
3807 The user is expected to provide a value for the key @code{#:import-path}
3808 and, in some cases, @code{#:unpack-path}. The
3809 @url{https://golang.org/doc/code.html#ImportPaths, import path}
3810 corresponds to the file system path expected by the package's build
3811 scripts and any referring packages, and provides a unique way to
3812 refer to a Go package. It is typically based on a combination of the
3813 package source code's remote URI and file system hierarchy structure. In
3814 some cases, you will need to unpack the package's source code to a
3815 different directory structure than the one indicated by the import path,
3816 and @code{#:unpack-path} should be used in such cases.
3818 Packages that provide Go libraries should be installed along with their
3819 source code. The key @code{#:install-source?}, which defaults to
3820 @code{#t}, controls whether or not the source code is installed. It can
3821 be set to @code{#f} for packages that only provide executable files.
3824 @defvr {Scheme Variable} glib-or-gtk-build-system
3825 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
3826 is intended for use with packages making use of GLib or GTK+.
3828 This build system adds the following two phases to the ones defined by
3829 @var{gnu-build-system}:
3832 @item glib-or-gtk-wrap
3833 The phase @code{glib-or-gtk-wrap} ensures that programs in
3834 @file{bin/} are able to find GLib ``schemas'' and
3835 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
3836 modules}. This is achieved by wrapping the programs in launch scripts
3837 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
3838 environment variables.
3840 It is possible to exclude specific package outputs from that wrapping
3841 process by listing their names in the
3842 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
3843 when an output is known not to contain any GLib or GTK+ binaries, and
3844 where wrapping would gratuitously add a dependency of that output on
3847 @item glib-or-gtk-compile-schemas
3848 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
3849 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
3850 GSettings schemas} of GLib are compiled. Compilation is performed by the
3851 @command{glib-compile-schemas} program. It is provided by the package
3852 @code{glib:bin} which is automatically imported by the build system.
3853 The @code{glib} package providing @command{glib-compile-schemas} can be
3854 specified with the @code{#:glib} parameter.
3857 Both phases are executed after the @code{install} phase.
3860 @defvr {Scheme Variable} minify-build-system
3861 This variable is exported by @code{(guix build-system minify)}. It
3862 implements a minification procedure for simple JavaScript packages.
3864 It adds @code{uglify-js} to the set of inputs and uses it to compress
3865 all JavaScript files in the @file{src} directory. A different minifier
3866 package can be specified with the @code{#:uglify-js} parameter, but it
3867 is expected that the package writes the minified code to the standard
3870 When the input JavaScript files are not all located in the @file{src}
3871 directory, the parameter @code{#:javascript-files} can be used to
3872 specify a list of file names to feed to the minifier.
3875 @defvr {Scheme Variable} ocaml-build-system
3876 This variable is exported by @code{(guix build-system ocaml)}. It implements
3877 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
3878 of choosing the correct set of commands to run for each package. OCaml
3879 packages can expect many different commands to be run. This build system will
3882 When the package has a @file{setup.ml} file present at the top-level, it will
3883 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
3884 @code{ocaml setup.ml -install}. The build system will assume that this file
3885 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
3886 care of setting the prefix and enabling tests if they are not disabled. You
3887 can pass configure and build flags with the @code{#:configure-flags} and
3888 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
3889 set of flags used to enable tests. The @code{#:use-make?} key can be used to
3890 bypass this system in the build and install phases.
3892 When the package has a @file{configure} file, it is assumed that it is a
3893 hand-made configure script that requires a different argument format than
3894 in the @code{gnu-build-system}. You can add more flags with the
3895 @code{#:configure-flags} key.
3897 When the package has a @file{Makefile} file (or @code{#:use-make?} is
3898 @code{#t}), it will be used and more flags can be passed to the build and
3899 install phases with the @code{#:make-flags} key.
3901 Finally, some packages do not have these files and use a somewhat standard
3902 location for its build system. In that case, the build system will run
3903 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
3904 providing the path to the required findlib module. Additional flags can
3905 be passed via the @code{#:build-flags} key. Install is taken care of by
3906 @command{opam-installer}. In this case, the @code{opam} package must
3907 be added to the @code{native-inputs} field of the package definition.
3909 Note that most OCaml packages assume they will be installed in the same
3910 directory as OCaml, which is not what we want in guix. In particular, they
3911 will install @file{.so} files in their module's directory, which is usually
3912 fine because it is in the OCaml compiler directory. In guix though, these
3913 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
3914 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
3915 @file{.so} libraries should be installed.
3918 @defvr {Scheme Variable} python-build-system
3919 This variable is exported by @code{(guix build-system python)}. It
3920 implements the more or less standard build procedure used by Python
3921 packages, which consists in running @code{python setup.py build} and
3922 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
3924 For packages that install stand-alone Python programs under @code{bin/},
3925 it takes care of wrapping these programs so that their @code{PYTHONPATH}
3926 environment variable points to all the Python libraries they depend on.
3928 Which Python package is used to perform the build can be specified with
3929 the @code{#:python} parameter. This is a useful way to force a package
3930 to be built for a specific version of the Python interpreter, which
3931 might be necessary if the package is only compatible with a single
3932 interpreter version.
3934 By default guix calls @code{setup.py} under control of
3935 @code{setuptools}, much like @command{pip} does. Some packages are not
3936 compatible with setuptools (and pip), thus you can disable this by
3937 setting the @code{#:use-setuptools} parameter to @code{#f}.
3940 @defvr {Scheme Variable} perl-build-system
3941 This variable is exported by @code{(guix build-system perl)}. It
3942 implements the standard build procedure for Perl packages, which either
3943 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
3944 followed by @code{Build} and @code{Build install}; or in running
3945 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
3946 @code{make} and @code{make install}, depending on which of
3947 @code{Build.PL} or @code{Makefile.PL} is present in the package
3948 distribution. Preference is given to the former if both @code{Build.PL}
3949 and @code{Makefile.PL} exist in the package distribution. This
3950 preference can be reversed by specifying @code{#t} for the
3951 @code{#:make-maker?} parameter.
3953 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
3954 passes flags specified by the @code{#:make-maker-flags} or
3955 @code{#:module-build-flags} parameter, respectively.
3957 Which Perl package is used can be specified with @code{#:perl}.
3960 @defvr {Scheme Variable} r-build-system
3961 This variable is exported by @code{(guix build-system r)}. It
3962 implements the build procedure used by @uref{http://r-project.org, R}
3963 packages, which essentially is little more than running @code{R CMD
3964 INSTALL --library=/gnu/store/@dots{}} in an environment where
3965 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
3966 are run after installation using the R function
3967 @code{tools::testInstalledPackage}.
3970 @defvr {Scheme Variable} texlive-build-system
3971 This variable is exported by @code{(guix build-system texlive)}. It is
3972 used to build TeX packages in batch mode with a specified engine. The
3973 build system sets the @code{TEXINPUTS} variable to find all TeX source
3974 files in the inputs.
3976 By default it runs @code{luatex} on all files ending on @code{ins}. A
3977 different engine and format can be specified with the
3978 @code{#:tex-format} argument. Different build targets can be specified
3979 with the @code{#:build-targets} argument, which expects a list of file
3980 names. The build system adds only @code{texlive-bin} and
3981 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
3982 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
3983 and @code{#:texlive-latex-base}, respectively.
3985 The @code{#:tex-directory} parameter tells the build system where to
3986 install the built files under the texmf tree.
3989 @defvr {Scheme Variable} ruby-build-system
3990 This variable is exported by @code{(guix build-system ruby)}. It
3991 implements the RubyGems build procedure used by Ruby packages, which
3992 involves running @code{gem build} followed by @code{gem install}.
3994 The @code{source} field of a package that uses this build system
3995 typically references a gem archive, since this is the format that Ruby
3996 developers use when releasing their software. The build system unpacks
3997 the gem archive, potentially patches the source, runs the test suite,
3998 repackages the gem, and installs it. Additionally, directories and
3999 tarballs may be referenced to allow building unreleased gems from Git or
4000 a traditional source release tarball.
4002 Which Ruby package is used can be specified with the @code{#:ruby}
4003 parameter. A list of additional flags to be passed to the @command{gem}
4004 command can be specified with the @code{#:gem-flags} parameter.
4007 @defvr {Scheme Variable} waf-build-system
4008 This variable is exported by @code{(guix build-system waf)}. It
4009 implements a build procedure around the @code{waf} script. The common
4010 phases---@code{configure}, @code{build}, and @code{install}---are
4011 implemented by passing their names as arguments to the @code{waf}
4014 The @code{waf} script is executed by the Python interpreter. Which
4015 Python package is used to run the script can be specified with the
4016 @code{#:python} parameter.
4019 @defvr {Scheme Variable} scons-build-system
4020 This variable is exported by @code{(guix build-system scons)}. It
4021 implements the build procedure used by the SCons software construction
4022 tool. This build system runs @code{scons} to build the package,
4023 @code{scons test} to run tests, and then @code{scons install} to install
4026 Additional flags to be passed to @code{scons} can be specified with the
4027 @code{#:scons-flags} parameter. The version of Python used to run SCons
4028 can be specified by selecting the appropriate SCons package with the
4029 @code{#:scons} parameter.
4032 @defvr {Scheme Variable} haskell-build-system
4033 This variable is exported by @code{(guix build-system haskell)}. It
4034 implements the Cabal build procedure used by Haskell packages, which
4035 involves running @code{runhaskell Setup.hs configure
4036 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
4037 Instead of installing the package by running @code{runhaskell Setup.hs
4038 install}, to avoid trying to register libraries in the read-only
4039 compiler store directory, the build system uses @code{runhaskell
4040 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
4041 addition, the build system generates the package documentation by
4042 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
4043 is passed. Optional Haddock parameters can be passed with the help of
4044 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
4045 not found, the build system looks for @code{Setup.lhs} instead.
4047 Which Haskell compiler is used can be specified with the @code{#:haskell}
4048 parameter which defaults to @code{ghc}.
4051 @defvr {Scheme Variable} dub-build-system
4052 This variable is exported by @code{(guix build-system dub)}. It
4053 implements the Dub build procedure used by D packages, which
4054 involves running @code{dub build} and @code{dub run}.
4055 Installation is done by copying the files manually.
4057 Which D compiler is used can be specified with the @code{#:ldc}
4058 parameter which defaults to @code{ldc}.
4061 @defvr {Scheme Variable} emacs-build-system
4062 This variable is exported by @code{(guix build-system emacs)}. It
4063 implements an installation procedure similar to the packaging system
4064 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
4066 It first creates the @code{@var{package}-autoloads.el} file, then it
4067 byte compiles all Emacs Lisp files. Differently from the Emacs
4068 packaging system, the Info documentation files are moved to the standard
4069 documentation directory and the @file{dir} file is deleted. Each
4070 package is installed in its own directory under
4071 @file{share/emacs/site-lisp/guix.d}.
4074 @defvr {Scheme Variable} font-build-system
4075 This variable is exported by @code{(guix build-system font)}. It
4076 implements an installation procedure for font packages where upstream
4077 provides pre-compiled TrueType, OpenType, etc. font files that merely
4078 need to be copied into place. It copies font files to standard
4079 locations in the output directory.
4082 @defvr {Scheme Variable} meson-build-system
4083 This variable is exported by @code{(guix build-system meson)}. It
4084 implements the build procedure for packages that use
4085 @url{http://mesonbuild.com, Meson} as their build system.
4087 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
4088 of inputs, and they can be changed with the parameters @code{#:meson}
4089 and @code{#:ninja} if needed. The default Meson is
4090 @code{meson-for-build}, which is special because it doesn't clear the
4091 @code{RUNPATH} of binaries and libraries when they are installed.
4093 This build system is an extension of @var{gnu-build-system}, but with the
4094 following phases changed to some specific for Meson:
4099 The phase runs @code{meson} with the flags specified in
4100 @code{#:configure-flags}. The flag @code{--build-type} is always set to
4101 @code{plain} unless something else is specified in @code{#:build-type}.
4104 The phase runs @code{ninja} to build the package in parallel by default, but
4105 this can be changed with @code{#:parallel-build?}.
4108 The phase runs @code{ninja} with the target specified in @code{#:test-target},
4109 which is @code{"test"} by default.
4112 The phase runs @code{ninja install} and can not be changed.
4115 Apart from that, the build system also adds the following phases:
4120 This phase ensures that all binaries can find the libraries they need.
4121 It searches for required libraries in subdirectories of the package being
4122 built, and adds those to @code{RUNPATH} where needed. It also removes
4123 references to libraries left over from the build phase by
4124 @code{meson-for-build}, such as test dependencies, that aren't actually
4125 required for the program to run.
4127 @item glib-or-gtk-wrap
4128 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
4129 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
4131 @item glib-or-gtk-compile-schemas
4132 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
4133 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
4137 Lastly, for packages that do not need anything as sophisticated, a
4138 ``trivial'' build system is provided. It is trivial in the sense that
4139 it provides basically no support: it does not pull any implicit inputs,
4140 and does not have a notion of build phases.
4142 @defvr {Scheme Variable} trivial-build-system
4143 This variable is exported by @code{(guix build-system trivial)}.
4145 This build system requires a @code{#:builder} argument. This argument
4146 must be a Scheme expression that builds the package output(s)---as
4147 with @code{build-expression->derivation} (@pxref{Derivations,
4148 @code{build-expression->derivation}}).
4158 Conceptually, the @dfn{store} is the place where derivations that have
4159 been built successfully are stored---by default, @file{/gnu/store}.
4160 Sub-directories in the store are referred to as @dfn{store items} or
4161 sometimes @dfn{store paths}. The store has an associated database that
4162 contains information such as the store paths referred to by each store
4163 path, and the list of @emph{valid} store items---results of successful
4164 builds. This database resides in @file{@var{localstatedir}/guix/db},
4165 where @var{localstatedir} is the state directory specified @i{via}
4166 @option{--localstatedir} at configure time, usually @file{/var}.
4168 The store is @emph{always} accessed by the daemon on behalf of its clients
4169 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
4170 connect to the daemon over a Unix-domain socket, send requests to it,
4171 and read the result---these are remote procedure calls, or RPCs.
4174 Users must @emph{never} modify files under @file{/gnu/store} directly.
4175 This would lead to inconsistencies and break the immutability
4176 assumptions of Guix's functional model (@pxref{Introduction}).
4178 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
4179 how to check the integrity of the store and attempt recovery from
4180 accidental modifications.
4183 The @code{(guix store)} module provides procedures to connect to the
4184 daemon, and to perform RPCs. These are described below. By default,
4185 @code{open-connection}, and thus all the @command{guix} commands,
4186 connect to the local daemon or to the URI specified by the
4187 @code{GUIX_DAEMON_SOCKET} environment variable.
4189 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
4190 When set, the value of this variable should be a file name or a URI
4191 designating the daemon endpoint. When it is a file name, it denotes a
4192 Unix-domain socket to connect to. In addition to file names, the
4193 supported URI schemes are:
4198 These are for Unix-domain sockets.
4199 @code{file:///var/guix/daemon-socket/socket} is equivalent to
4200 @file{/var/guix/daemon-socket/socket}.
4203 @cindex daemon, remote access
4204 @cindex remote access to the daemon
4205 @cindex daemon, cluster setup
4206 @cindex clusters, daemon setup
4207 These URIs denote connections over TCP/IP, without encryption nor
4208 authentication of the remote host. The URI must specify the host name
4209 and optionally a port number (by default port 44146 is used):
4212 guix://master.guix.example.org:1234
4215 This setup is suitable on local networks, such as clusters, where only
4216 trusted nodes may connect to the build daemon at
4217 @code{master.guix.example.org}.
4219 The @code{--listen} option of @command{guix-daemon} can be used to
4220 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
4224 @cindex SSH access to build daemons
4225 These URIs allow you to connect to a remote daemon over
4226 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
4227 A typical URL might look like this:
4230 ssh://charlie@@guix.example.org:22
4233 As for @command{guix copy}, the usual OpenSSH client configuration files
4234 are honored (@pxref{Invoking guix copy}).
4237 Additional URI schemes may be supported in the future.
4239 @c XXX: Remove this note when the protocol incurs fewer round trips
4240 @c and when (guix derivations) no longer relies on file system access.
4242 The ability to connect to remote build daemons is considered
4243 experimental as of @value{VERSION}. Please get in touch with us to
4244 share any problems or suggestions you may have (@pxref{Contributing}).
4248 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
4249 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
4250 @var{reserve-space?} is true, instruct it to reserve a little bit of
4251 extra space on the file system so that the garbage collector can still
4252 operate should the disk become full. Return a server object.
4254 @var{file} defaults to @var{%default-socket-path}, which is the normal
4255 location given the options that were passed to @command{configure}.
4258 @deffn {Scheme Procedure} close-connection @var{server}
4259 Close the connection to @var{server}.
4262 @defvr {Scheme Variable} current-build-output-port
4263 This variable is bound to a SRFI-39 parameter, which refers to the port
4264 where build and error logs sent by the daemon should be written.
4267 Procedures that make RPCs all take a server object as their first
4270 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
4271 @cindex invalid store items
4272 Return @code{#t} when @var{path} designates a valid store item and
4273 @code{#f} otherwise (an invalid item may exist on disk but still be
4274 invalid, for instance because it is the result of an aborted or failed
4277 A @code{&nix-protocol-error} condition is raised if @var{path} is not
4278 prefixed by the store directory (@file{/gnu/store}).
4281 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
4282 Add @var{text} under file @var{name} in the store, and return its store
4283 path. @var{references} is the list of store paths referred to by the
4284 resulting store path.
4287 @deffn {Scheme Procedure} build-derivations @var{server} @var{derivations}
4288 Build @var{derivations} (a list of @code{<derivation>} objects or
4289 derivation paths), and return when the worker is done building them.
4290 Return @code{#t} on success.
4293 Note that the @code{(guix monads)} module provides a monad as well as
4294 monadic versions of the above procedures, with the goal of making it
4295 more convenient to work with code that accesses the store (@pxref{The
4299 @i{This section is currently incomplete.}
4302 @section Derivations
4305 Low-level build actions and the environment in which they are performed
4306 are represented by @dfn{derivations}. A derivation contains the
4307 following pieces of information:
4311 The outputs of the derivation---derivations produce at least one file or
4312 directory in the store, but may produce more.
4315 The inputs of the derivations, which may be other derivations or plain
4316 files in the store (patches, build scripts, etc.)
4319 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
4322 The file name of a build script in the store, along with the arguments
4326 A list of environment variables to be defined.
4330 @cindex derivation path
4331 Derivations allow clients of the daemon to communicate build actions to
4332 the store. They exist in two forms: as an in-memory representation,
4333 both on the client- and daemon-side, and as files in the store whose
4334 name end in @code{.drv}---these files are referred to as @dfn{derivation
4335 paths}. Derivations paths can be passed to the @code{build-derivations}
4336 procedure to perform the build actions they prescribe (@pxref{The
4339 @cindex fixed-output derivations
4340 Operations such as file downloads and version-control checkouts for
4341 which the expected content hash is known in advance are modeled as
4342 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
4343 of a fixed-output derivation are independent of its inputs---e.g., a
4344 source code download produces the same result regardless of the download
4345 method and tools being used.
4347 The @code{(guix derivations)} module provides a representation of
4348 derivations as Scheme objects, along with procedures to create and
4349 otherwise manipulate derivations. The lowest-level primitive to create
4350 a derivation is the @code{derivation} procedure:
4352 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
4353 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
4354 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
4355 [#:system (%current-system)] [#:references-graphs #f] @
4356 [#:allowed-references #f] [#:disallowed-references #f] @
4357 [#:leaked-env-vars #f] [#:local-build? #f] @
4358 [#:substitutable? #t]
4359 Build a derivation with the given arguments, and return the resulting
4360 @code{<derivation>} object.
4362 When @var{hash} and @var{hash-algo} are given, a
4363 @dfn{fixed-output derivation} is created---i.e., one whose result is
4364 known in advance, such as a file download. If, in addition,
4365 @var{recursive?} is true, then that fixed output may be an executable
4366 file or a directory and @var{hash} must be the hash of an archive
4367 containing this output.
4369 When @var{references-graphs} is true, it must be a list of file
4370 name/store path pairs. In that case, the reference graph of each store
4371 path is exported in the build environment in the corresponding file, in
4372 a simple text format.
4374 When @var{allowed-references} is true, it must be a list of store items
4375 or outputs that the derivation's output may refer to. Likewise,
4376 @var{disallowed-references}, if true, must be a list of things the
4377 outputs may @emph{not} refer to.
4379 When @var{leaked-env-vars} is true, it must be a list of strings
4380 denoting environment variables that are allowed to ``leak'' from the
4381 daemon's environment to the build environment. This is only applicable
4382 to fixed-output derivations---i.e., when @var{hash} is true. The main
4383 use is to allow variables such as @code{http_proxy} to be passed to
4384 derivations that download files.
4386 When @var{local-build?} is true, declare that the derivation is not a
4387 good candidate for offloading and should rather be built locally
4388 (@pxref{Daemon Offload Setup}). This is the case for small derivations
4389 where the costs of data transfers would outweigh the benefits.
4391 When @var{substitutable?} is false, declare that substitutes of the
4392 derivation's output should not be used (@pxref{Substitutes}). This is
4393 useful, for instance, when building packages that capture details of the
4394 host CPU instruction set.
4398 Here's an example with a shell script as its builder, assuming
4399 @var{store} is an open connection to the daemon, and @var{bash} points
4400 to a Bash executable in the store:
4403 (use-modules (guix utils)
4407 (let ((builder ; add the Bash script to the store
4408 (add-text-to-store store "my-builder.sh"
4409 "echo hello world > $out\n" '())))
4410 (derivation store "foo"
4411 bash `("-e" ,builder)
4412 #:inputs `((,bash) (,builder))
4413 #:env-vars '(("HOME" . "/homeless"))))
4414 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
4417 As can be guessed, this primitive is cumbersome to use directly. A
4418 better approach is to write build scripts in Scheme, of course! The
4419 best course of action for that is to write the build code as a
4420 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
4421 information, @pxref{G-Expressions}.
4423 Once upon a time, @code{gexp->derivation} did not exist and constructing
4424 derivations with build code written in Scheme was achieved with
4425 @code{build-expression->derivation}, documented below. This procedure
4426 is now deprecated in favor of the much nicer @code{gexp->derivation}.
4428 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
4429 @var{name} @var{exp} @
4430 [#:system (%current-system)] [#:inputs '()] @
4431 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
4432 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
4433 [#:references-graphs #f] [#:allowed-references #f] @
4434 [#:disallowed-references #f] @
4435 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
4436 Return a derivation that executes Scheme expression @var{exp} as a
4437 builder for derivation @var{name}. @var{inputs} must be a list of
4438 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
4439 @code{"out"} is assumed. @var{modules} is a list of names of Guile
4440 modules from the current search path to be copied in the store,
4441 compiled, and made available in the load path during the execution of
4442 @var{exp}---e.g., @code{((guix build utils) (guix build
4443 gnu-build-system))}.
4445 @var{exp} is evaluated in an environment where @code{%outputs} is bound
4446 to a list of output/path pairs, and where @code{%build-inputs} is bound
4447 to a list of string/output-path pairs made from @var{inputs}.
4448 Optionally, @var{env-vars} is a list of string pairs specifying the name
4449 and value of environment variables visible to the builder. The builder
4450 terminates by passing the result of @var{exp} to @code{exit}; thus, when
4451 @var{exp} returns @code{#f}, the build is considered to have failed.
4453 @var{exp} is built using @var{guile-for-build} (a derivation). When
4454 @var{guile-for-build} is omitted or is @code{#f}, the value of the
4455 @code{%guile-for-build} fluid is used instead.
4457 See the @code{derivation} procedure for the meaning of
4458 @var{references-graphs}, @var{allowed-references},
4459 @var{disallowed-references}, @var{local-build?}, and
4460 @var{substitutable?}.
4464 Here's an example of a single-output derivation that creates a directory
4465 containing one file:
4468 (let ((builder '(let ((out (assoc-ref %outputs "out")))
4469 (mkdir out) ; create /gnu/store/@dots{}-goo
4470 (call-with-output-file (string-append out "/test")
4472 (display '(hello guix) p))))))
4473 (build-expression->derivation store "goo" builder))
4475 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
4479 @node The Store Monad
4480 @section The Store Monad
4484 The procedures that operate on the store described in the previous
4485 sections all take an open connection to the build daemon as their first
4486 argument. Although the underlying model is functional, they either have
4487 side effects or depend on the current state of the store.
4489 The former is inconvenient: the connection to the build daemon has to be
4490 carried around in all those functions, making it impossible to compose
4491 functions that do not take that parameter with functions that do. The
4492 latter can be problematic: since store operations have side effects
4493 and/or depend on external state, they have to be properly sequenced.
4495 @cindex monadic values
4496 @cindex monadic functions
4497 This is where the @code{(guix monads)} module comes in. This module
4498 provides a framework for working with @dfn{monads}, and a particularly
4499 useful monad for our uses, the @dfn{store monad}. Monads are a
4500 construct that allows two things: associating ``context'' with values
4501 (in our case, the context is the store), and building sequences of
4502 computations (here computations include accesses to the store). Values
4503 in a monad---values that carry this additional context---are called
4504 @dfn{monadic values}; procedures that return such values are called
4505 @dfn{monadic procedures}.
4507 Consider this ``normal'' procedure:
4510 (define (sh-symlink store)
4511 ;; Return a derivation that symlinks the 'bash' executable.
4512 (let* ((drv (package-derivation store bash))
4513 (out (derivation->output-path drv))
4514 (sh (string-append out "/bin/bash")))
4515 (build-expression->derivation store "sh"
4516 `(symlink ,sh %output))))
4519 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
4520 as a monadic function:
4523 (define (sh-symlink)
4524 ;; Same, but return a monadic value.
4525 (mlet %store-monad ((drv (package->derivation bash)))
4526 (gexp->derivation "sh"
4527 #~(symlink (string-append #$drv "/bin/bash")
4531 There are several things to note in the second version: the @code{store}
4532 parameter is now implicit and is ``threaded'' in the calls to the
4533 @code{package->derivation} and @code{gexp->derivation} monadic
4534 procedures, and the monadic value returned by @code{package->derivation}
4535 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
4537 As it turns out, the call to @code{package->derivation} can even be
4538 omitted since it will take place implicitly, as we will see later
4539 (@pxref{G-Expressions}):
4542 (define (sh-symlink)
4543 (gexp->derivation "sh"
4544 #~(symlink (string-append #$bash "/bin/bash")
4549 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
4550 @c for the funny quote.
4551 Calling the monadic @code{sh-symlink} has no effect. As someone once
4552 said, ``you exit a monad like you exit a building on fire: by running''.
4553 So, to exit the monad and get the desired effect, one must use
4554 @code{run-with-store}:
4557 (run-with-store (open-connection) (sh-symlink))
4558 @result{} /gnu/store/...-sh-symlink
4561 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
4562 new ``meta-commands'' to make it easier to deal with monadic procedures:
4563 @code{run-in-store}, and @code{enter-store-monad}. The former is used
4564 to ``run'' a single monadic value through the store:
4567 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
4568 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
4571 The latter enters a recursive REPL, where all the return values are
4572 automatically run through the store:
4575 scheme@@(guile-user)> ,enter-store-monad
4576 store-monad@@(guile-user) [1]> (package->derivation hello)
4577 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
4578 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
4579 $3 = "/gnu/store/@dots{}-foo"
4580 store-monad@@(guile-user) [1]> ,q
4581 scheme@@(guile-user)>
4585 Note that non-monadic values cannot be returned in the
4586 @code{store-monad} REPL.
4588 The main syntactic forms to deal with monads in general are provided by
4589 the @code{(guix monads)} module and are described below.
4591 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
4592 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
4596 @deffn {Scheme Syntax} return @var{val}
4597 Return a monadic value that encapsulates @var{val}.
4600 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
4601 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
4602 procedures @var{mproc}@dots{}@footnote{This operation is commonly
4603 referred to as ``bind'', but that name denotes an unrelated procedure in
4604 Guile. Thus we use this somewhat cryptic symbol inherited from the
4605 Haskell language.}. There can be one @var{mproc} or several of them, as
4610 (with-monad %state-monad
4612 (lambda (x) (return (+ 1 x)))
4613 (lambda (x) (return (* 2 x)))))
4617 @result{} some-state
4621 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
4623 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
4625 Bind the variables @var{var} to the monadic values @var{mval} in
4626 @var{body}, which is a sequence of expressions. As with the bind
4627 operator, this can be thought of as ``unpacking'' the raw, non-monadic
4628 value ``contained'' in @var{mval} and making @var{var} refer to that
4629 raw, non-monadic value within the scope of the @var{body}. The form
4630 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
4631 @var{val}, as per @code{let}. The binding operations occur in sequence
4632 from left to right. The last expression of @var{body} must be a monadic
4633 expression, and its result will become the result of the @code{mlet} or
4634 @code{mlet*} when run in the @var{monad}.
4636 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
4637 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
4640 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
4641 Bind @var{mexp} and the following monadic expressions in sequence,
4642 returning the result of the last expression. Every expression in the
4643 sequence must be a monadic expression.
4645 This is akin to @code{mlet}, except that the return values of the
4646 monadic expressions are ignored. In that sense, it is analogous to
4647 @code{begin}, but applied to monadic expressions.
4650 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
4651 When @var{condition} is true, evaluate the sequence of monadic
4652 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
4653 @var{condition} is false, return @code{*unspecified*} in the current
4654 monad. Every expression in the sequence must be a monadic expression.
4657 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
4658 When @var{condition} is false, evaluate the sequence of monadic
4659 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
4660 @var{condition} is true, return @code{*unspecified*} in the current
4661 monad. Every expression in the sequence must be a monadic expression.
4665 The @code{(guix monads)} module provides the @dfn{state monad}, which
4666 allows an additional value---the state---to be @emph{threaded} through
4667 monadic procedure calls.
4669 @defvr {Scheme Variable} %state-monad
4670 The state monad. Procedures in the state monad can access and change
4671 the state that is threaded.
4673 Consider the example below. The @code{square} procedure returns a value
4674 in the state monad. It returns the square of its argument, but also
4675 increments the current state value:
4679 (mlet %state-monad ((count (current-state)))
4680 (mbegin %state-monad
4681 (set-current-state (+ 1 count))
4684 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
4689 When ``run'' through @var{%state-monad}, we obtain that additional state
4690 value, which is the number of @code{square} calls.
4693 @deffn {Monadic Procedure} current-state
4694 Return the current state as a monadic value.
4697 @deffn {Monadic Procedure} set-current-state @var{value}
4698 Set the current state to @var{value} and return the previous state as a
4702 @deffn {Monadic Procedure} state-push @var{value}
4703 Push @var{value} to the current state, which is assumed to be a list,
4704 and return the previous state as a monadic value.
4707 @deffn {Monadic Procedure} state-pop
4708 Pop a value from the current state and return it as a monadic value.
4709 The state is assumed to be a list.
4712 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
4713 Run monadic value @var{mval} starting with @var{state} as the initial
4714 state. Return two values: the resulting value, and the resulting state.
4717 The main interface to the store monad, provided by the @code{(guix
4718 store)} module, is as follows.
4720 @defvr {Scheme Variable} %store-monad
4721 The store monad---an alias for @var{%state-monad}.
4723 Values in the store monad encapsulate accesses to the store. When its
4724 effect is needed, a value of the store monad must be ``evaluated'' by
4725 passing it to the @code{run-with-store} procedure (see below.)
4728 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
4729 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
4730 open store connection.
4733 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
4734 Return as a monadic value the absolute file name in the store of the file
4735 containing @var{text}, a string. @var{references} is a list of store items that the
4736 resulting text file refers to; it defaults to the empty list.
4739 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
4740 [#:recursive? #t] [#:select? (const #t)]
4741 Return the name of @var{file} once interned in the store. Use
4742 @var{name} as its store name, or the basename of @var{file} if
4743 @var{name} is omitted.
4745 When @var{recursive?} is true, the contents of @var{file} are added
4746 recursively; if @var{file} designates a flat file and @var{recursive?}
4747 is true, its contents are added, and its permission bits are kept.
4749 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
4750 @var{stat})} for each directory entry, where @var{file} is the entry's
4751 absolute file name and @var{stat} is the result of @code{lstat}; exclude
4752 entries for which @var{select?} does not return true.
4754 The example below adds a file to the store, under two different names:
4757 (run-with-store (open-connection)
4758 (mlet %store-monad ((a (interned-file "README"))
4759 (b (interned-file "README" "LEGU-MIN")))
4760 (return (list a b))))
4762 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
4767 The @code{(guix packages)} module exports the following package-related
4770 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
4771 [#:system (%current-system)] [#:target #f] @
4774 value in the absolute file name of @var{file} within the @var{output}
4775 directory of @var{package}. When @var{file} is omitted, return the name
4776 of the @var{output} directory of @var{package}. When @var{target} is
4777 true, use it as a cross-compilation target triplet.
4780 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
4781 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
4782 @var{target} [@var{system}]
4783 Monadic version of @code{package-derivation} and
4784 @code{package-cross-derivation} (@pxref{Defining Packages}).
4789 @section G-Expressions
4791 @cindex G-expression
4792 @cindex build code quoting
4793 So we have ``derivations'', which represent a sequence of build actions
4794 to be performed to produce an item in the store (@pxref{Derivations}).
4795 These build actions are performed when asking the daemon to actually
4796 build the derivations; they are run by the daemon in a container
4797 (@pxref{Invoking guix-daemon}).
4799 @cindex strata of code
4800 It should come as no surprise that we like to write these build actions
4801 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
4802 code@footnote{The term @dfn{stratum} in this context was coined by
4803 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
4804 Kiselyov, who has written insightful
4805 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
4806 on this topic}, refers to this kind of code generation as
4807 @dfn{staging}.}: the ``host code''---code that defines packages, talks
4808 to the daemon, etc.---and the ``build code''---code that actually
4809 performs build actions, such as making directories, invoking
4810 @command{make}, etc.
4812 To describe a derivation and its build actions, one typically needs to
4813 embed build code inside host code. It boils down to manipulating build
4814 code as data, and the homoiconicity of Scheme---code has a direct
4815 representation as data---comes in handy for that. But we need more than
4816 the normal @code{quasiquote} mechanism in Scheme to construct build
4819 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
4820 S-expressions adapted to build expressions. G-expressions, or
4821 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
4822 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
4823 @code{#$}, and @code{#$@@}), which are comparable to
4824 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
4825 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
4826 GNU Guile Reference Manual}). However, there are major differences:
4830 Gexps are meant to be written to a file and run or manipulated by other
4834 When a high-level object such as a package or derivation is unquoted
4835 inside a gexp, the result is as if its output file name had been
4839 Gexps carry information about the packages or derivations they refer to,
4840 and these dependencies are automatically added as inputs to the build
4841 processes that use them.
4844 @cindex lowering, of high-level objects in gexps
4845 This mechanism is not limited to package and derivation
4846 objects: @dfn{compilers} able to ``lower'' other high-level objects to
4847 derivations or files in the store can be defined,
4848 such that these objects can also be inserted
4849 into gexps. For example, a useful type of high-level objects that can be
4850 inserted in a gexp is ``file-like objects'', which make it easy to
4851 add files to the store and to refer to them in
4852 derivations and such (see @code{local-file} and @code{plain-file}
4855 To illustrate the idea, here is an example of a gexp:
4862 (symlink (string-append #$coreutils "/bin/ls")
4866 This gexp can be passed to @code{gexp->derivation}; we obtain a
4867 derivation that builds a directory containing exactly one symlink to
4868 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
4871 (gexp->derivation "the-thing" build-exp)
4874 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
4875 substituted to the reference to the @var{coreutils} package in the
4876 actual build code, and @var{coreutils} is automatically made an input to
4877 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
4878 output)}) is replaced by a string containing the directory name of the
4879 output of the derivation.
4881 @cindex cross compilation
4882 In a cross-compilation context, it is useful to distinguish between
4883 references to the @emph{native} build of a package---that can run on the
4884 host---versus references to cross builds of a package. To that end, the
4885 @code{#+} plays the same role as @code{#$}, but is a reference to a
4886 native package build:
4889 (gexp->derivation "vi"
4892 (system* (string-append #+coreutils "/bin/ln")
4894 (string-append #$emacs "/bin/emacs")
4895 (string-append #$output "/bin/vi")))
4896 #:target "mips64el-linux-gnu")
4900 In the example above, the native build of @var{coreutils} is used, so
4901 that @command{ln} can actually run on the host; but then the
4902 cross-compiled build of @var{emacs} is referenced.
4904 @cindex imported modules, for gexps
4905 @findex with-imported-modules
4906 Another gexp feature is @dfn{imported modules}: sometimes you want to be
4907 able to use certain Guile modules from the ``host environment'' in the
4908 gexp, so those modules should be imported in the ``build environment''.
4909 The @code{with-imported-modules} form allows you to express that:
4912 (let ((build (with-imported-modules '((guix build utils))
4914 (use-modules (guix build utils))
4915 (mkdir-p (string-append #$output "/bin"))))))
4916 (gexp->derivation "empty-dir"
4919 (display "success!\n")
4924 In this example, the @code{(guix build utils)} module is automatically
4925 pulled into the isolated build environment of our gexp, such that
4926 @code{(use-modules (guix build utils))} works as expected.
4928 @cindex module closure
4929 @findex source-module-closure
4930 Usually you want the @emph{closure} of the module to be imported---i.e.,
4931 the module itself and all the modules it depends on---rather than just
4932 the module; failing to do that, attempts to use the module will fail
4933 because of missing dependent modules. The @code{source-module-closure}
4934 procedure computes the closure of a module by looking at its source file
4935 headers, which comes in handy in this case:
4938 (use-modules (guix modules)) ;for 'source-module-closure'
4940 (with-imported-modules (source-module-closure
4941 '((guix build utils)
4943 (gexp->derivation "something-with-vms"
4945 (use-modules (guix build utils)
4950 The syntactic form to construct gexps is summarized below.
4952 @deffn {Scheme Syntax} #~@var{exp}
4953 @deffnx {Scheme Syntax} (gexp @var{exp})
4954 Return a G-expression containing @var{exp}. @var{exp} may contain one
4955 or more of the following forms:
4959 @itemx (ungexp @var{obj})
4960 Introduce a reference to @var{obj}. @var{obj} may have one of the
4961 supported types, for example a package or a
4962 derivation, in which case the @code{ungexp} form is replaced by its
4963 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
4965 If @var{obj} is a list, it is traversed and references to supported
4966 objects are substituted similarly.
4968 If @var{obj} is another gexp, its contents are inserted and its
4969 dependencies are added to those of the containing gexp.
4971 If @var{obj} is another kind of object, it is inserted as is.
4973 @item #$@var{obj}:@var{output}
4974 @itemx (ungexp @var{obj} @var{output})
4975 This is like the form above, but referring explicitly to the
4976 @var{output} of @var{obj}---this is useful when @var{obj} produces
4977 multiple outputs (@pxref{Packages with Multiple Outputs}).
4980 @itemx #+@var{obj}:output
4981 @itemx (ungexp-native @var{obj})
4982 @itemx (ungexp-native @var{obj} @var{output})
4983 Same as @code{ungexp}, but produces a reference to the @emph{native}
4984 build of @var{obj} when used in a cross compilation context.
4986 @item #$output[:@var{output}]
4987 @itemx (ungexp output [@var{output}])
4988 Insert a reference to derivation output @var{output}, or to the main
4989 output when @var{output} is omitted.
4991 This only makes sense for gexps passed to @code{gexp->derivation}.
4994 @itemx (ungexp-splicing @var{lst})
4995 Like the above, but splices the contents of @var{lst} inside the
4999 @itemx (ungexp-native-splicing @var{lst})
5000 Like the above, but refers to native builds of the objects listed in
5005 G-expressions created by @code{gexp} or @code{#~} are run-time objects
5006 of the @code{gexp?} type (see below.)
5009 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
5010 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
5011 in their execution environment.
5013 Each item in @var{modules} can be the name of a module, such as
5014 @code{(guix build utils)}, or it can be a module name, followed by an
5015 arrow, followed by a file-like object:
5018 `((guix build utils)
5020 ((guix config) => ,(scheme-file "config.scm"
5021 #~(define-module @dots{}))))
5025 In the example above, the first two modules are taken from the search
5026 path, and the last one is created from the given file-like object.
5028 This form has @emph{lexical} scope: it has an effect on the gexps
5029 directly defined in @var{body}@dots{}, but not on those defined, say, in
5030 procedures called from @var{body}@dots{}.
5033 @deffn {Scheme Procedure} gexp? @var{obj}
5034 Return @code{#t} if @var{obj} is a G-expression.
5037 G-expressions are meant to be written to disk, either as code building
5038 some derivation, or as plain files in the store. The monadic procedures
5039 below allow you to do that (@pxref{The Store Monad}, for more
5040 information about monads.)
5042 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
5043 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
5044 [#:hash #f] [#:hash-algo #f] @
5045 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
5046 [#:module-path @var{%load-path}] @
5047 [#:references-graphs #f] [#:allowed-references #f] @
5048 [#:disallowed-references #f] @
5049 [#:leaked-env-vars #f] @
5050 [#:script-name (string-append @var{name} "-builder")] @
5051 [#:deprecation-warnings #f] @
5052 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
5053 Return a derivation @var{name} that runs @var{exp} (a gexp) with
5054 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
5055 stored in a file called @var{script-name}. When @var{target} is true,
5056 it is used as the cross-compilation target triplet for packages referred
5059 @var{modules} is deprecated in favor of @code{with-imported-modules}.
5061 make @var{modules} available in the evaluation context of @var{exp};
5062 @var{modules} is a list of names of Guile modules searched in
5063 @var{module-path} to be copied in the store, compiled, and made available in
5064 the load path during the execution of @var{exp}---e.g., @code{((guix
5065 build utils) (guix build gnu-build-system))}.
5067 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
5070 When @var{references-graphs} is true, it must be a list of tuples of one of the
5074 (@var{file-name} @var{package})
5075 (@var{file-name} @var{package} @var{output})
5076 (@var{file-name} @var{derivation})
5077 (@var{file-name} @var{derivation} @var{output})
5078 (@var{file-name} @var{store-item})
5081 The right-hand-side of each element of @var{references-graphs} is automatically made
5082 an input of the build process of @var{exp}. In the build environment, each
5083 @var{file-name} contains the reference graph of the corresponding item, in a simple
5086 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
5087 In the latter case, the list denotes store items that the result is allowed to
5088 refer to. Any reference to another store item will lead to a build error.
5089 Similarly for @var{disallowed-references}, which can list items that must not be
5090 referenced by the outputs.
5092 @var{deprecation-warnings} determines whether to show deprecation warnings while
5093 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
5095 The other arguments are as for @code{derivation} (@pxref{Derivations}).
5098 @cindex file-like objects
5099 The @code{local-file}, @code{plain-file}, @code{computed-file},
5100 @code{program-file}, and @code{scheme-file} procedures below return
5101 @dfn{file-like objects}. That is, when unquoted in a G-expression,
5102 these objects lead to a file in the store. Consider this G-expression:
5105 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
5106 #$(local-file "/tmp/my-nscd.conf"))
5109 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
5110 to the store. Once expanded, for instance @i{via}
5111 @code{gexp->derivation}, the G-expression refers to that copy under
5112 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
5113 does not have any effect on what the G-expression does.
5114 @code{plain-file} can be used similarly; it differs in that the file
5115 content is directly passed as a string.
5117 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
5118 [#:recursive? #f] [#:select? (const #t)]
5119 Return an object representing local file @var{file} to add to the store; this
5120 object can be used in a gexp. If @var{file} is a relative file name, it is looked
5121 up relative to the source file where this form appears. @var{file} will be added to
5122 the store under @var{name}--by default the base name of @var{file}.
5124 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
5125 designates a flat file and @var{recursive?} is true, its contents are added, and its
5126 permission bits are kept.
5128 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
5129 @var{stat})} for each directory entry, where @var{file} is the entry's
5130 absolute file name and @var{stat} is the result of @code{lstat}; exclude
5131 entries for which @var{select?} does not return true.
5133 This is the declarative counterpart of the @code{interned-file} monadic
5134 procedure (@pxref{The Store Monad, @code{interned-file}}).
5137 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
5138 Return an object representing a text file called @var{name} with the given
5139 @var{content} (a string) to be added to the store.
5141 This is the declarative counterpart of @code{text-file}.
5144 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
5145 [#:options '(#:local-build? #t)]
5146 Return an object representing the store item @var{name}, a file or
5147 directory computed by @var{gexp}. @var{options}
5148 is a list of additional arguments to pass to @code{gexp->derivation}.
5150 This is the declarative counterpart of @code{gexp->derivation}.
5153 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp}
5154 Return an executable script @var{name} that runs @var{exp} using
5155 @var{guile}, with @var{exp}'s imported modules in its search path.
5157 The example below builds a script that simply invokes the @command{ls}
5161 (use-modules (guix gexp) (gnu packages base))
5163 (gexp->script "list-files"
5164 #~(execl #$(file-append coreutils "/bin/ls")
5168 When ``running'' it through the store (@pxref{The Store Monad,
5169 @code{run-with-store}}), we obtain a derivation that produces an
5170 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
5173 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
5175 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
5179 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
5181 Return an object representing the executable store item @var{name} that
5182 runs @var{gexp}. @var{guile} is the Guile package used to execute that
5185 This is the declarative counterpart of @code{gexp->script}.
5188 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
5189 [#:set-load-path? #t]
5190 Return a derivation that builds a file @var{name} containing @var{exp}.
5191 When @var{set-load-path?} is true, emit code in the resulting file to
5192 set @code{%load-path} and @code{%load-compiled-path} to honor
5193 @var{exp}'s imported modules.
5195 The resulting file holds references to all the dependencies of @var{exp}
5196 or a subset thereof.
5199 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp}
5200 Return an object representing the Scheme file @var{name} that contains
5203 This is the declarative counterpart of @code{gexp->file}.
5206 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
5207 Return as a monadic value a derivation that builds a text file
5208 containing all of @var{text}. @var{text} may list, in addition to
5209 strings, objects of any type that can be used in a gexp: packages,
5210 derivations, local file objects, etc. The resulting store file holds
5211 references to all these.
5213 This variant should be preferred over @code{text-file} anytime the file
5214 to create will reference items from the store. This is typically the
5215 case when building a configuration file that embeds store file names,
5219 (define (profile.sh)
5220 ;; Return the name of a shell script in the store that
5221 ;; initializes the 'PATH' environment variable.
5222 (text-file* "profile.sh"
5223 "export PATH=" coreutils "/bin:"
5224 grep "/bin:" sed "/bin\n"))
5227 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
5228 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
5229 preventing them from being garbage-collected during its lifetime.
5232 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
5233 Return an object representing store file @var{name} containing
5234 @var{text}. @var{text} is a sequence of strings and file-like objects,
5238 (mixed-text-file "profile"
5239 "export PATH=" coreutils "/bin:" grep "/bin")
5242 This is the declarative counterpart of @code{text-file*}.
5245 @deffn {Scheme Procedure} file-union @var{name} @var{files}
5246 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
5247 Each item in @var{files} must be a two-element list where the first element is the
5248 file name to use in the new directory, and the second element is a gexp
5249 denoting the target file. Here's an example:
5253 `(("hosts" ,(plain-file "hosts"
5254 "127.0.0.1 localhost"))
5255 ("bashrc" ,(plain-file "bashrc"
5256 "alias ls='ls --color'"))))
5259 This yields an @code{etc} directory containing these two files.
5262 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
5263 Return a directory that is the union of @var{things}, where @var{things} is a list of
5264 file-like objects denoting directories. For example:
5267 (directory-union "guile+emacs" (list guile emacs))
5270 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
5273 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
5274 Return a file-like object that expands to the concatenation of @var{obj}
5275 and @var{suffix}, where @var{obj} is a lowerable object and each
5276 @var{suffix} is a string.
5278 As an example, consider this gexp:
5281 (gexp->script "run-uname"
5282 #~(system* #$(file-append coreutils
5286 The same effect could be achieved with:
5289 (gexp->script "run-uname"
5290 #~(system* (string-append #$coreutils
5294 There is one difference though: in the @code{file-append} case, the
5295 resulting script contains the absolute file name as a string, whereas in
5296 the second case, the resulting script contains a @code{(string-append
5297 @dots{})} expression to construct the file name @emph{at run time}.
5301 Of course, in addition to gexps embedded in ``host'' code, there are
5302 also modules containing build tools. To make it clear that they are
5303 meant to be used in the build stratum, these modules are kept in the
5304 @code{(guix build @dots{})} name space.
5306 @cindex lowering, of high-level objects in gexps
5307 Internally, high-level objects are @dfn{lowered}, using their compiler,
5308 to either derivations or store items. For instance, lowering a package
5309 yields a derivation, and lowering a @code{plain-file} yields a store
5310 item. This is achieved using the @code{lower-object} monadic procedure.
5312 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
5314 Return as a value in @var{%store-monad} the derivation or store item
5315 corresponding to @var{obj} for @var{system}, cross-compiling for
5316 @var{target} if @var{target} is true. @var{obj} must be an object that
5317 has an associated gexp compiler, such as a @code{<package>}.
5321 @c *********************************************************************
5325 This section describes Guix command-line utilities. Some of them are
5326 primarily targeted at developers and users who write new package
5327 definitions, while others are more generally useful. They complement
5328 the Scheme programming interface of Guix in a convenient way.
5331 * Invoking guix build:: Building packages from the command line.
5332 * Invoking guix edit:: Editing package definitions.
5333 * Invoking guix download:: Downloading a file and printing its hash.
5334 * Invoking guix hash:: Computing the cryptographic hash of a file.
5335 * Invoking guix import:: Importing package definitions.
5336 * Invoking guix refresh:: Updating package definitions.
5337 * Invoking guix lint:: Finding errors in package definitions.
5338 * Invoking guix size:: Profiling disk usage.
5339 * Invoking guix graph:: Visualizing the graph of packages.
5340 * Invoking guix environment:: Setting up development environments.
5341 * Invoking guix publish:: Sharing substitutes.
5342 * Invoking guix challenge:: Challenging substitute servers.
5343 * Invoking guix copy:: Copying to and from a remote store.
5344 * Invoking guix container:: Process isolation.
5345 * Invoking guix weather:: Assessing substitute availability.
5348 @node Invoking guix build
5349 @section Invoking @command{guix build}
5351 @cindex package building
5352 @cindex @command{guix build}
5353 The @command{guix build} command builds packages or derivations and
5354 their dependencies, and prints the resulting store paths. Note that it
5355 does not modify the user's profile---this is the job of the
5356 @command{guix package} command (@pxref{Invoking guix package}). Thus,
5357 it is mainly useful for distribution developers.
5359 The general syntax is:
5362 guix build @var{options} @var{package-or-derivation}@dots{}
5365 As an example, the following command builds the latest versions of Emacs
5366 and of Guile, displays their build logs, and finally displays the
5367 resulting directories:
5370 guix build emacs guile
5373 Similarly, the following command builds all the available packages:
5376 guix build --quiet --keep-going \
5377 `guix package -A | cut -f1,2 --output-delimiter=@@`
5380 @var{package-or-derivation} may be either the name of a package found in
5381 the software distribution such as @code{coreutils} or
5382 @code{coreutils@@8.20}, or a derivation such as
5383 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
5384 package with the corresponding name (and optionally version) is searched
5385 for among the GNU distribution modules (@pxref{Package Modules}).
5387 Alternatively, the @code{--expression} option may be used to specify a
5388 Scheme expression that evaluates to a package; this is useful when
5389 disambiguating among several same-named packages or package variants is
5392 There may be zero or more @var{options}. The available options are
5393 described in the subsections below.
5396 * Common Build Options:: Build options for most commands.
5397 * Package Transformation Options:: Creating variants of packages.
5398 * Additional Build Options:: Options specific to 'guix build'.
5399 * Debugging Build Failures:: Real life packaging experience.
5402 @node Common Build Options
5403 @subsection Common Build Options
5405 A number of options that control the build process are common to
5406 @command{guix build} and other commands that can spawn builds, such as
5407 @command{guix package} or @command{guix archive}. These are the
5412 @item --load-path=@var{directory}
5413 @itemx -L @var{directory}
5414 Add @var{directory} to the front of the package module search path
5415 (@pxref{Package Modules}).
5417 This allows users to define their own packages and make them visible to
5418 the command-line tools.
5422 Keep the build tree of failed builds. Thus, if a build fails, its build
5423 tree is kept under @file{/tmp}, in a directory whose name is shown at
5424 the end of the build log. This is useful when debugging build issues.
5425 @xref{Debugging Build Failures}, for tips and tricks on how to debug
5430 Keep going when some of the derivations fail to build; return only once
5431 all the builds have either completed or failed.
5433 The default behavior is to stop as soon as one of the specified
5434 derivations has failed.
5438 Do not build the derivations.
5440 @anchor{fallback-option}
5442 When substituting a pre-built binary fails, fall back to building
5443 packages locally (@pxref{Substitution Failure}).
5445 @item --substitute-urls=@var{urls}
5446 @anchor{client-substitute-urls}
5447 Consider @var{urls} the whitespace-separated list of substitute source
5448 URLs, overriding the default list of URLs of @command{guix-daemon}
5449 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
5451 This means that substitutes may be downloaded from @var{urls}, provided
5452 they are signed by a key authorized by the system administrator
5453 (@pxref{Substitutes}).
5455 When @var{urls} is the empty string, substitutes are effectively
5458 @item --no-substitutes
5459 Do not use substitutes for build products. That is, always build things
5460 locally instead of allowing downloads of pre-built binaries
5461 (@pxref{Substitutes}).
5464 Do not ``graft'' packages. In practice, this means that package updates
5465 available as grafts are not applied. @xref{Security Updates}, for more
5466 information on grafts.
5468 @item --rounds=@var{n}
5469 Build each derivation @var{n} times in a row, and raise an error if
5470 consecutive build results are not bit-for-bit identical.
5472 This is a useful way to detect non-deterministic builds processes.
5473 Non-deterministic build processes are a problem because they make it
5474 practically impossible for users to @emph{verify} whether third-party
5475 binaries are genuine. @xref{Invoking guix challenge}, for more.
5477 Note that, currently, the differing build results are not kept around,
5478 so you will have to manually investigate in case of an error---e.g., by
5479 stashing one of the build results with @code{guix archive --export}
5480 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
5483 @item --no-build-hook
5484 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
5485 (@pxref{Daemon Offload Setup}). That is, always build things locally
5486 instead of offloading builds to remote machines.
5488 @item --max-silent-time=@var{seconds}
5489 When the build or substitution process remains silent for more than
5490 @var{seconds}, terminate it and report a build failure.
5492 By default, the daemon's setting is honored (@pxref{Invoking
5493 guix-daemon, @code{--max-silent-time}}).
5495 @item --timeout=@var{seconds}
5496 Likewise, when the build or substitution process lasts for more than
5497 @var{seconds}, terminate it and report a build failure.
5499 By default, the daemon's setting is honored (@pxref{Invoking
5500 guix-daemon, @code{--timeout}}).
5502 @item --verbosity=@var{level}
5503 Use the given verbosity level. @var{level} must be an integer between 0
5504 and 5; higher means more verbose output. Setting a level of 4 or more
5505 may be helpful when debugging setup issues with the build daemon.
5507 @item --cores=@var{n}
5509 Allow the use of up to @var{n} CPU cores for the build. The special
5510 value @code{0} means to use as many CPU cores as available.
5512 @item --max-jobs=@var{n}
5514 Allow at most @var{n} build jobs in parallel. @xref{Invoking
5515 guix-daemon, @code{--max-jobs}}, for details about this option and the
5516 equivalent @command{guix-daemon} option.
5520 Behind the scenes, @command{guix build} is essentially an interface to
5521 the @code{package-derivation} procedure of the @code{(guix packages)}
5522 module, and to the @code{build-derivations} procedure of the @code{(guix
5523 derivations)} module.
5525 In addition to options explicitly passed on the command line,
5526 @command{guix build} and other @command{guix} commands that support
5527 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
5529 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
5530 Users can define this variable to a list of command line options that
5531 will automatically be used by @command{guix build} and other
5532 @command{guix} commands that can perform builds, as in the example
5536 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
5539 These options are parsed independently, and the result is appended to
5540 the parsed command-line options.
5544 @node Package Transformation Options
5545 @subsection Package Transformation Options
5547 @cindex package variants
5548 Another set of command-line options supported by @command{guix build}
5549 and also @command{guix package} are @dfn{package transformation
5550 options}. These are options that make it possible to define @dfn{package
5551 variants}---for instance, packages built from different source code.
5552 This is a convenient way to create customized packages on the fly
5553 without having to type in the definitions of package variants
5554 (@pxref{Defining Packages}).
5558 @item --with-source=@var{source}
5559 @itemx --with-source=@var{package}=@var{source}
5560 @itemx --with-source=@var{package}@@@var{version}=@var{source}
5561 Use @var{source} as the source of @var{package}, and @var{version} as
5563 @var{source} must be a file name or a URL, as for @command{guix
5564 download} (@pxref{Invoking guix download}).
5566 When @var{package} is omitted,
5567 it is taken to be the package name specified on the
5568 command line that matches the base of @var{source}---e.g.,
5569 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
5570 package is @code{guile}.
5572 Likewise, when @var{version} is omitted, the version string is inferred from
5573 @var{source}; in the previous example, it is @code{2.0.10}.
5575 This option allows users to try out versions of packages other than the
5576 one provided by the distribution. The example below downloads
5577 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
5578 the @code{ed} package:
5581 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
5584 As a developer, @code{--with-source} makes it easy to test release
5588 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
5591 @dots{} or to build from a checkout in a pristine environment:
5594 $ git clone git://git.sv.gnu.org/guix.git
5595 $ guix build guix --with-source=guix@@1.0=./guix
5598 @item --with-input=@var{package}=@var{replacement}
5599 Replace dependency on @var{package} by a dependency on
5600 @var{replacement}. @var{package} must be a package name, and
5601 @var{replacement} must be a package specification such as @code{guile}
5602 or @code{guile@@1.8}.
5604 For instance, the following command builds Guix, but replaces its
5605 dependency on the current stable version of Guile with a dependency on
5606 the legacy version of Guile, @code{guile@@2.0}:
5609 guix build --with-input=guile=guile@@2.0 guix
5612 This is a recursive, deep replacement. So in this example, both
5613 @code{guix} and its dependency @code{guile-json} (which also depends on
5614 @code{guile}) get rebuilt against @code{guile@@2.0}.
5616 This is implemented using the @code{package-input-rewriting} Scheme
5617 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
5619 @item --with-graft=@var{package}=@var{replacement}
5620 This is similar to @code{--with-input} but with an important difference:
5621 instead of rebuilding the whole dependency chain, @var{replacement} is
5622 built and then @dfn{grafted} onto the binaries that were initially
5623 referring to @var{package}. @xref{Security Updates}, for more
5624 information on grafts.
5626 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
5627 and all its dependencies, replacing references to the version of GnuTLS
5628 they currently refer to:
5631 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
5634 This has the advantage of being much faster than rebuilding everything.
5635 But there is a caveat: it works if and only if @var{package} and
5636 @var{replacement} are strictly compatible---for example, if they provide
5637 a library, the application binary interface (ABI) of those libraries
5638 must be compatible. If @var{replacement} is somehow incompatible with
5639 @var{package}, then the resulting package may be unusable. Use with
5644 @node Additional Build Options
5645 @subsection Additional Build Options
5647 The command-line options presented below are specific to @command{guix
5654 Build quietly, without displaying the build log. Upon completion, the
5655 build log is kept in @file{/var} (or similar) and can always be
5656 retrieved using the @option{--log-file} option.
5658 @item --file=@var{file}
5659 @itemx -f @var{file}
5661 Build the package or derivation that the code within @var{file}
5664 As an example, @var{file} might contain a package definition like this
5665 (@pxref{Defining Packages}):
5668 @verbatiminclude package-hello.scm
5671 @item --expression=@var{expr}
5672 @itemx -e @var{expr}
5673 Build the package or derivation @var{expr} evaluates to.
5675 For example, @var{expr} may be @code{(@@ (gnu packages guile)
5676 guile-1.8)}, which unambiguously designates this specific variant of
5677 version 1.8 of Guile.
5679 Alternatively, @var{expr} may be a G-expression, in which case it is used
5680 as a build program passed to @code{gexp->derivation}
5681 (@pxref{G-Expressions}).
5683 Lastly, @var{expr} may refer to a zero-argument monadic procedure
5684 (@pxref{The Store Monad}). The procedure must return a derivation as a
5685 monadic value, which is then passed through @code{run-with-store}.
5689 Build the source derivations of the packages, rather than the packages
5692 For instance, @code{guix build -S gcc} returns something like
5693 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
5696 The returned source tarball is the result of applying any patches and
5697 code snippets specified in the package @code{origin} (@pxref{Defining
5701 Fetch and return the source of @var{package-or-derivation} and all their
5702 dependencies, recursively. This is a handy way to obtain a local copy
5703 of all the source code needed to build @var{packages}, allowing you to
5704 eventually build them even without network access. It is an extension
5705 of the @code{--source} option and can accept one of the following
5706 optional argument values:
5710 This value causes the @code{--sources} option to behave in the same way
5711 as the @code{--source} option.
5714 Build the source derivations of all packages, including any source that
5715 might be listed as @code{inputs}. This is the default value.
5718 $ guix build --sources tzdata
5719 The following derivations will be built:
5720 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
5721 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
5725 Build the source derivations of all packages, as well of all transitive
5726 inputs to the packages. This can be used e.g. to
5727 prefetch package source for later offline building.
5730 $ guix build --sources=transitive tzdata
5731 The following derivations will be built:
5732 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
5733 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
5734 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
5735 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
5736 /gnu/store/@dots{}-make-4.1.tar.xz.drv
5737 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
5743 @item --system=@var{system}
5744 @itemx -s @var{system}
5745 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5746 the system type of the build host.
5749 The @code{--system} flag is for @emph{native} compilation and must not
5750 be confused with cross-compilation. See @code{--target} below for
5751 information on cross-compilation.
5754 An example use of this is on Linux-based systems, which can emulate
5755 different personalities. For instance, passing
5756 @code{--system=i686-linux} on an @code{x86_64-linux} system allows you
5757 to build packages in a complete 32-bit environment.
5759 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
5760 is enabled (@pxref{Virtualization Services,
5761 @code{qemu-binfmt-service-type}}), you can build for any system for
5762 which a QEMU @code{binfmt_misc} handler is installed.
5764 Builds for a system other than that of the machine you are using can
5765 also be offloaded to a remote machine of the right architecture.
5766 @xref{Daemon Offload Setup}, for more information on offloading.
5768 @item --target=@var{triplet}
5769 @cindex cross-compilation
5770 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5771 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
5772 configuration triplets,, autoconf, Autoconf}).
5774 @anchor{build-check}
5776 @cindex determinism, checking
5777 @cindex reproducibility, checking
5778 Rebuild @var{package-or-derivation}, which are already available in the
5779 store, and raise an error if the build results are not bit-for-bit
5782 This mechanism allows you to check whether previously installed
5783 substitutes are genuine (@pxref{Substitutes}), or whether the build result
5784 of a package is deterministic. @xref{Invoking guix challenge}, for more
5785 background information and tools.
5787 When used in conjunction with @option{--keep-failed}, the differing
5788 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
5789 This makes it easy to look for differences between the two results.
5792 @cindex repairing store items
5793 @cindex corruption, recovering from
5794 Attempt to repair the specified store items, if they are corrupt, by
5795 re-downloading or rebuilding them.
5797 This operation is not atomic and thus restricted to @code{root}.
5801 Return the derivation paths, not the output paths, of the given
5804 @item --root=@var{file}
5805 @itemx -r @var{file}
5806 @cindex GC roots, adding
5807 @cindex garbage collector roots, adding
5808 Make @var{file} a symlink to the result, and register it as a garbage
5811 Consequently, the results of this @command{guix build} invocation are
5812 protected from garbage collection until @var{file} is removed. When
5813 that option is omitted, build results are eligible for garbage
5814 collection as soon as the build completes. @xref{Invoking guix gc}, for
5818 @cindex build logs, access
5819 Return the build log file names or URLs for the given
5820 @var{package-or-derivation}, or raise an error if build logs are
5823 This works regardless of how packages or derivations are specified. For
5824 instance, the following invocations are equivalent:
5827 guix build --log-file `guix build -d guile`
5828 guix build --log-file `guix build guile`
5829 guix build --log-file guile
5830 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
5833 If a log is unavailable locally, and unless @code{--no-substitutes} is
5834 passed, the command looks for a corresponding log on one of the
5835 substitute servers (as specified with @code{--substitute-urls}.)
5837 So for instance, imagine you want to see the build log of GDB on MIPS,
5838 but you are actually on an @code{x86_64} machine:
5841 $ guix build --log-file gdb -s mips64el-linux
5842 https://hydra.gnu.org/log/@dots{}-gdb-7.10
5845 You can freely access a huge library of build logs!
5848 @node Debugging Build Failures
5849 @subsection Debugging Build Failures
5851 @cindex build failures, debugging
5852 When defining a new package (@pxref{Defining Packages}), you will
5853 probably find yourself spending some time debugging and tweaking the
5854 build until it succeeds. To do that, you need to operate the build
5855 commands yourself in an environment as close as possible to the one the
5858 To that end, the first thing to do is to use the @option{--keep-failed}
5859 or @option{-K} option of @command{guix build}, which will keep the
5860 failed build tree in @file{/tmp} or whatever directory you specified as
5861 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
5863 From there on, you can @command{cd} to the failed build tree and source
5864 the @file{environment-variables} file, which contains all the
5865 environment variable definitions that were in place when the build
5866 failed. So let's say you're debugging a build failure in package
5867 @code{foo}; a typical session would look like this:
5871 @dots{} @i{build fails}
5872 $ cd /tmp/guix-build-foo.drv-0
5873 $ source ./environment-variables
5877 Now, you can invoke commands as if you were the daemon (almost) and
5878 troubleshoot your build process.
5880 Sometimes it happens that, for example, a package's tests pass when you
5881 run them manually but they fail when the daemon runs them. This can
5882 happen because the daemon runs builds in containers where, unlike in our
5883 environment above, network access is missing, @file{/bin/sh} does not
5884 exist, etc. (@pxref{Build Environment Setup}).
5886 In such cases, you may need to run inspect the build process from within
5887 a container similar to the one the build daemon creates:
5892 $ cd /tmp/guix-build-foo.drv-0
5893 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
5894 [env]# source ./environment-variables
5898 Here, @command{guix environment -C} creates a container and spawns a new
5899 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
5900 strace gdb} part adds the @command{strace} and @command{gdb} commands to
5901 the container, which would may find handy while debugging. The
5902 @option{--no-grafts} option makes sure we get the exact same
5903 environment, with ungrafted packages (@pxref{Security Updates}, for more
5906 To get closer to a container like that used by the build daemon, we can
5907 remove @file{/bin/sh}:
5913 (Don't worry, this is harmless: this is all happening in the throw-away
5914 container created by @command{guix environment}.)
5916 The @command{strace} command is probably not in the search path, but we
5920 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
5923 In this way, not only you will have reproduced the environment variables
5924 the daemon uses, you will also be running the build process in a container
5925 similar to the one the daemon uses.
5928 @node Invoking guix edit
5929 @section Invoking @command{guix edit}
5931 @cindex @command{guix edit}
5932 @cindex package definition, editing
5933 So many packages, so many source files! The @command{guix edit} command
5934 facilitates the life of users and packagers by pointing their editor at
5935 the source file containing the definition of the specified packages.
5939 guix edit gcc@@4.9 vim
5943 launches the program specified in the @code{VISUAL} or in the
5944 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
5947 If you are using a Guix Git checkout (@pxref{Building from Git}), or
5948 have created your own packages on @code{GUIX_PACKAGE_PATH}
5949 (@pxref{Defining Packages}), you will be able to edit the package
5950 recipes. Otherwise, you will be able to examine the read-only recipes
5951 for packages currently in the store.
5954 @node Invoking guix download
5955 @section Invoking @command{guix download}
5957 @cindex @command{guix download}
5958 @cindex downloading package sources
5959 When writing a package definition, developers typically need to download
5960 a source tarball, compute its SHA256 hash, and write that
5961 hash in the package definition (@pxref{Defining Packages}). The
5962 @command{guix download} tool helps with this task: it downloads a file
5963 from the given URI, adds it to the store, and prints both its file name
5964 in the store and its SHA256 hash.
5966 The fact that the downloaded file is added to the store saves bandwidth:
5967 when the developer eventually tries to build the newly defined package
5968 with @command{guix build}, the source tarball will not have to be
5969 downloaded again because it is already in the store. It is also a
5970 convenient way to temporarily stash files, which may be deleted
5971 eventually (@pxref{Invoking guix gc}).
5973 The @command{guix download} command supports the same URIs as used in
5974 package definitions. In particular, it supports @code{mirror://} URIs.
5975 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
5976 Guile bindings for GnuTLS are available in the user's environment; when
5977 they are not available, an error is raised. @xref{Guile Preparations,
5978 how to install the GnuTLS bindings for Guile,, gnutls-guile,
5979 GnuTLS-Guile}, for more information.
5981 @command{guix download} verifies HTTPS server certificates by loading
5982 the certificates of X.509 authorities from the directory pointed to by
5983 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
5984 Certificates}), unless @option{--no-check-certificate} is used.
5986 The following options are available:
5989 @item --format=@var{fmt}
5991 Write the hash in the format specified by @var{fmt}. For more
5992 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
5994 @item --no-check-certificate
5995 Do not validate the X.509 certificates of HTTPS servers.
5997 When using this option, you have @emph{absolutely no guarantee} that you
5998 are communicating with the authentic server responsible for the given
5999 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
6001 @item --output=@var{file}
6002 @itemx -o @var{file}
6003 Save the downloaded file to @var{file} instead of adding it to the
6007 @node Invoking guix hash
6008 @section Invoking @command{guix hash}
6010 @cindex @command{guix hash}
6011 The @command{guix hash} command computes the SHA256 hash of a file.
6012 It is primarily a convenience tool for anyone contributing to the
6013 distribution: it computes the cryptographic hash of a file, which can be
6014 used in the definition of a package (@pxref{Defining Packages}).
6016 The general syntax is:
6019 guix hash @var{option} @var{file}
6022 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
6023 hash of data read from standard input. @command{guix hash} has the
6028 @item --format=@var{fmt}
6030 Write the hash in the format specified by @var{fmt}.
6032 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
6033 (@code{hex} and @code{hexadecimal} can be used as well).
6035 If the @option{--format} option is not specified, @command{guix hash}
6036 will output the hash in @code{nix-base32}. This representation is used
6037 in the definitions of packages.
6041 Compute the hash on @var{file} recursively.
6043 In this case, the hash is computed on an archive containing @var{file},
6044 including its children if it is a directory. Some of the metadata of
6045 @var{file} is part of the archive; for instance, when @var{file} is a
6046 regular file, the hash is different depending on whether @var{file} is
6047 executable or not. Metadata such as time stamps has no impact on the
6048 hash (@pxref{Invoking guix archive}).
6049 @c FIXME: Replace xref above with xref to an ``Archive'' section when
6054 When combined with @option{--recursive}, exclude version control system
6055 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
6058 As an example, here is how you would compute the hash of a Git checkout,
6059 which is useful when using the @code{git-fetch} method (@pxref{origin
6063 $ git clone http://example.org/foo.git
6069 @node Invoking guix import
6070 @section Invoking @command{guix import}
6072 @cindex importing packages
6073 @cindex package import
6074 @cindex package conversion
6075 @cindex Invoking @command{guix import}
6076 The @command{guix import} command is useful for people who would like to
6077 add a package to the distribution with as little work as
6078 possible---a legitimate demand. The command knows of a few
6079 repositories from which it can ``import'' package metadata. The result
6080 is a package definition, or a template thereof, in the format we know
6081 (@pxref{Defining Packages}).
6083 The general syntax is:
6086 guix import @var{importer} @var{options}@dots{}
6089 @var{importer} specifies the source from which to import package
6090 metadata, and @var{options} specifies a package identifier and other
6091 options specific to @var{importer}. Currently, the available
6096 Import metadata for the given GNU package. This provides a template
6097 for the latest version of that GNU package, including the hash of its
6098 source tarball, and its canonical synopsis and description.
6100 Additional information such as the package dependencies and its
6101 license needs to be figured out manually.
6103 For example, the following command returns a package definition for
6107 guix import gnu hello
6110 Specific command-line options are:
6113 @item --key-download=@var{policy}
6114 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
6115 keys when verifying the package signature. @xref{Invoking guix
6116 refresh, @code{--key-download}}.
6121 Import metadata from the @uref{https://pypi.python.org/, Python Package
6122 Index}@footnote{This functionality requires Guile-JSON to be installed.
6123 @xref{Requirements}.}. Information is taken from the JSON-formatted
6124 description available at @code{pypi.python.org} and usually includes all
6125 the relevant information, including package dependencies. For maximum
6126 efficiency, it is recommended to install the @command{unzip} utility, so
6127 that the importer can unzip Python wheels and gather data from them.
6129 The command below imports metadata for the @code{itsdangerous} Python
6133 guix import pypi itsdangerous
6138 Import metadata from @uref{https://rubygems.org/,
6139 RubyGems}@footnote{This functionality requires Guile-JSON to be
6140 installed. @xref{Requirements}.}. Information is taken from the
6141 JSON-formatted description available at @code{rubygems.org} and includes
6142 most relevant information, including runtime dependencies. There are
6143 some caveats, however. The metadata doesn't distinguish between
6144 synopses and descriptions, so the same string is used for both fields.
6145 Additionally, the details of non-Ruby dependencies required to build
6146 native extensions is unavailable and left as an exercise to the
6149 The command below imports metadata for the @code{rails} Ruby package:
6152 guix import gem rails
6157 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}@footnote{This
6158 functionality requires Guile-JSON to be installed.
6159 @xref{Requirements}.}.
6160 Information is taken from the JSON-formatted metadata provided through
6161 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
6162 relevant information, such as module dependencies. License information
6163 should be checked closely. If Perl is available in the store, then the
6164 @code{corelist} utility will be used to filter core modules out of the
6165 list of dependencies.
6167 The command command below imports metadata for the @code{Acme::Boolean}
6171 guix import cpan Acme::Boolean
6176 @cindex Bioconductor
6177 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
6178 central repository for the @uref{http://r-project.org, GNU@tie{}R
6179 statistical and graphical environment}.
6181 Information is extracted from the @code{DESCRIPTION} file of the package.
6183 The command command below imports metadata for the @code{Cairo}
6187 guix import cran Cairo
6190 When @code{--recursive} is added, the importer will traverse the
6191 dependency graph of the given upstream package recursively and generate
6192 package expressions for all those packages that are not yet in Guix.
6194 When @code{--archive=bioconductor} is added, metadata is imported from
6195 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
6196 packages for for the analysis and comprehension of high-throughput
6197 genomic data in bioinformatics.
6199 Information is extracted from the @code{DESCRIPTION} file of a package
6200 published on the web interface of the Bioconductor SVN repository.
6202 The command below imports metadata for the @code{GenomicRanges}
6206 guix import cran --archive=bioconductor GenomicRanges
6212 Import metadata from @uref{http://www.ctan.org/, CTAN}, the
6213 comprehensive TeX archive network for TeX packages that are part of the
6214 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
6216 Information about the package is obtained through the XML API provided
6217 by CTAN, while the source code is downloaded from the SVN repository of
6218 the Tex Live project. This is done because the CTAN does not keep
6221 The command command below imports metadata for the @code{fontspec}
6225 guix import texlive fontspec
6228 When @code{--archive=DIRECTORY} is added, the source code is downloaded
6229 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
6230 tree in the TeX Live SVN repository, but from the specified sibling
6231 directory under the same root.
6233 The command below imports metadata for the @code{ifxetex} package from
6234 CTAN while fetching the sources from the directory
6235 @file{texmf/source/generic}:
6238 guix import texlive --archive=generic ifxetex
6242 @cindex JSON, import
6243 Import package metadata from a local JSON file@footnote{This
6244 functionality requires Guile-JSON to be installed.
6245 @xref{Requirements}.}. Consider the following example package
6246 definition in JSON format:
6252 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
6253 "build-system": "gnu",
6254 "home-page": "https://www.gnu.org/software/hello/",
6255 "synopsis": "Hello, GNU world: An example GNU package",
6256 "description": "GNU Hello prints a greeting.",
6257 "license": "GPL-3.0+",
6258 "native-inputs": ["gcc@@6"]
6262 The field names are the same as for the @code{<package>} record
6263 (@xref{Defining Packages}). References to other packages are provided
6264 as JSON lists of quoted package specification strings such as
6265 @code{guile} or @code{guile@@2.0}.
6267 The importer also supports a more explicit source definition using the
6268 common fields for @code{<origin>} records:
6274 "method": "url-fetch",
6275 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
6277 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
6284 The command below reads metadata from the JSON file @code{hello.json}
6285 and outputs a package expression:
6288 guix import json hello.json
6292 Import metadata from a local copy of the source of the
6293 @uref{http://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
6294 relies on the @command{nix-instantiate} command of
6295 @uref{http://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
6296 typically written in a mixture of Nix-language and Bash code. This
6297 command only imports the high-level package structure that is written in
6298 the Nix language. It normally includes all the basic fields of a
6301 When importing a GNU package, the synopsis and descriptions are replaced
6302 by their canonical upstream variant.
6304 Usually, you will first need to do:
6307 export NIX_REMOTE=daemon
6311 so that @command{nix-instantiate} does not try to open the Nix database.
6313 As an example, the command below imports the package definition of
6314 LibreOffice (more precisely, it imports the definition of the package
6315 bound to the @code{libreoffice} top-level attribute):
6318 guix import nix ~/path/to/nixpkgs libreoffice
6323 Import metadata from the Haskell community's central package archive
6324 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
6325 Cabal files and includes all the relevant information, including package
6328 Specific command-line options are:
6333 Read a Cabal file from standard input.
6334 @item --no-test-dependencies
6336 Do not include dependencies required only by the test suites.
6337 @item --cabal-environment=@var{alist}
6338 @itemx -e @var{alist}
6339 @var{alist} is a Scheme alist defining the environment in which the
6340 Cabal conditionals are evaluated. The accepted keys are: @code{os},
6341 @code{arch}, @code{impl} and a string representing the name of a flag.
6342 The value associated with a flag has to be either the symbol
6343 @code{true} or @code{false}. The value associated with other keys
6344 has to conform to the Cabal file format definition. The default value
6345 associated with the keys @code{os}, @code{arch} and @code{impl} is
6346 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
6349 The command below imports metadata for the latest version of the
6350 @code{HTTP} Haskell package without including test dependencies and
6351 specifying the value of the flag @samp{network-uri} as @code{false}:
6354 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
6357 A specific package version may optionally be specified by following the
6358 package name by an at-sign and a version number as in the following example:
6361 guix import hackage mtl@@2.1.3.1
6366 The @code{stackage} importer is a wrapper around the @code{hackage} one.
6367 It takes a package name, looks up the package version included in a
6368 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
6369 release and uses the @code{hackage} importer to retrieve its metadata.
6370 Note that it is up to you to select an LTS release compatible with the
6371 GHC compiler used by Guix.
6373 Specific command-line options are:
6376 @item --no-test-dependencies
6378 Do not include dependencies required only by the test suites.
6379 @item --lts-version=@var{version}
6380 @itemx -r @var{version}
6381 @var{version} is the desired LTS release version. If omitted the latest
6385 The command below imports metadata for the @code{HTTP} Haskell package
6386 included in the LTS Stackage release version 7.18:
6389 guix import stackage --lts-version=7.18 HTTP
6394 Import metadata from an Emacs Lisp Package Archive (ELPA) package
6395 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6397 Specific command-line options are:
6400 @item --archive=@var{repo}
6401 @itemx -a @var{repo}
6402 @var{repo} identifies the archive repository from which to retrieve the
6403 information. Currently the supported repositories and their identifiers
6407 @uref{http://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
6408 identifier. This is the default.
6410 Packages from @code{elpa.gnu.org} are signed with one of the keys
6411 contained in the GnuPG keyring at
6412 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
6413 @code{emacs} package (@pxref{Package Installation, ELPA package
6414 signatures,, emacs, The GNU Emacs Manual}).
6417 @uref{http://stable.melpa.org/packages, MELPA-Stable}, selected by the
6418 @code{melpa-stable} identifier.
6421 @uref{http://melpa.org/packages, MELPA}, selected by the @code{melpa}
6428 Import metadata from the crates.io Rust package repository
6429 @uref{https://crates.io, crates.io}.
6432 The structure of the @command{guix import} code is modular. It would be
6433 useful to have more importers for other package formats, and your help
6434 is welcome here (@pxref{Contributing}).
6436 @node Invoking guix refresh
6437 @section Invoking @command{guix refresh}
6439 @cindex @command {guix refresh}
6440 The primary audience of the @command{guix refresh} command is developers
6441 of the GNU software distribution. By default, it reports any packages
6442 provided by the distribution that are outdated compared to the latest
6443 upstream version, like this:
6447 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
6448 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
6451 Alternately, one can specify packages to consider, in which case a
6452 warning is emitted for packages that lack an updater:
6455 $ guix refresh coreutils guile guile-ssh
6456 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
6457 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
6460 @command{guix refresh} browses the upstream repository of each package and determines
6461 the highest version number of the releases therein. The command
6462 knows how to update specific types of packages: GNU packages, ELPA
6463 packages, etc.---see the documentation for @option{--type} below. There
6464 are many packages, though, for which it lacks a method to determine
6465 whether a new upstream release is available. However, the mechanism is
6466 extensible, so feel free to get in touch with us to add a new method!
6468 Sometimes the upstream name differs from the package name used in Guix,
6469 and @command{guix refresh} needs a little help. Most updaters honor the
6470 @code{upstream-name} property in package definitions, which can be used
6474 (define-public network-manager
6476 (name "network-manager")
6478 (properties '((upstream-name . "NetworkManager")))))
6481 When passed @code{--update}, it modifies distribution source files to
6482 update the version numbers and source tarball hashes of those package
6483 recipes (@pxref{Defining Packages}). This is achieved by downloading
6484 each package's latest source tarball and its associated OpenPGP
6485 signature, authenticating the downloaded tarball against its signature
6486 using @command{gpg}, and finally computing its hash. When the public
6487 key used to sign the tarball is missing from the user's keyring, an
6488 attempt is made to automatically retrieve it from a public key server;
6489 when this is successful, the key is added to the user's keyring; otherwise,
6490 @command{guix refresh} reports an error.
6492 The following options are supported:
6496 @item --expression=@var{expr}
6497 @itemx -e @var{expr}
6498 Consider the package @var{expr} evaluates to.
6500 This is useful to precisely refer to a package, as in this example:
6503 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
6506 This command lists the dependents of the ``final'' libc (essentially all
6511 Update distribution source files (package recipes) in place. This is
6512 usually run from a checkout of the Guix source tree (@pxref{Running
6513 Guix Before It Is Installed}):
6516 $ ./pre-inst-env guix refresh -s non-core -u
6519 @xref{Defining Packages}, for more information on package definitions.
6521 @item --select=[@var{subset}]
6522 @itemx -s @var{subset}
6523 Select all the packages in @var{subset}, one of @code{core} or
6526 The @code{core} subset refers to all the packages at the core of the
6527 distribution---i.e., packages that are used to build ``everything
6528 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
6529 changing one of these packages in the distribution entails a rebuild of
6530 all the others. Thus, such updates are an inconvenience to users in
6531 terms of build time or bandwidth used to achieve the upgrade.
6533 The @code{non-core} subset refers to the remaining packages. It is
6534 typically useful in cases where an update of the core packages would be
6537 @item --manifest=@var{file}
6538 @itemx -m @var{file}
6539 Select all the packages from the manifest in @var{file}. This is useful to
6540 check if any packages of the user manifest can be updated.
6542 @item --type=@var{updater}
6543 @itemx -t @var{updater}
6544 Select only packages handled by @var{updater} (may be a comma-separated
6545 list of updaters). Currently, @var{updater} may be one of:
6549 the updater for GNU packages;
6551 the updater for GNOME packages;
6553 the updater for KDE packages;
6555 the updater for X.org packages;
6557 the updater for packages hosted on kernel.org;
6559 the updater for @uref{http://elpa.gnu.org/, ELPA} packages;
6561 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
6563 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
6565 the updater for @uref{http://www.cpan.org/, CPAN} packages;
6567 the updater for @uref{https://pypi.python.org, PyPI} packages.
6569 the updater for @uref{https://rubygems.org, RubyGems} packages.
6571 the updater for @uref{https://github.com, GitHub} packages.
6573 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
6575 the updater for @uref{https://www.stackage.org, Stackage} packages.
6577 the updater for @uref{https://crates.io, Crates} packages.
6580 For instance, the following command only checks for updates of Emacs
6581 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
6584 $ guix refresh --type=elpa,cran
6585 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
6586 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
6591 In addition, @command{guix refresh} can be passed one or more package
6592 names, as in this example:
6595 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
6599 The command above specifically updates the @code{emacs} and
6600 @code{idutils} packages. The @code{--select} option would have no
6601 effect in this case.
6603 When considering whether to upgrade a package, it is sometimes
6604 convenient to know which packages would be affected by the upgrade and
6605 should be checked for compatibility. For this the following option may
6606 be used when passing @command{guix refresh} one or more package names:
6610 @item --list-updaters
6612 List available updaters and exit (see @option{--type} above.)
6614 For each updater, display the fraction of packages it covers; at the
6615 end, display the fraction of packages covered by all these updaters.
6617 @item --list-dependent
6619 List top-level dependent packages that would need to be rebuilt as a
6620 result of upgrading one or more packages.
6622 @xref{Invoking guix graph, the @code{reverse-package} type of
6623 @command{guix graph}}, for information on how to visualize the list of
6624 dependents of a package.
6628 Be aware that the @code{--list-dependent} option only
6629 @emph{approximates} the rebuilds that would be required as a result of
6630 an upgrade. More rebuilds might be required under some circumstances.
6633 $ guix refresh --list-dependent flex
6634 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
6635 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
6638 The command above lists a set of packages that could be built to check
6639 for compatibility with an upgraded @code{flex} package.
6641 The following options can be used to customize GnuPG operation:
6645 @item --gpg=@var{command}
6646 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
6647 for in @code{$PATH}.
6649 @item --key-download=@var{policy}
6650 Handle missing OpenPGP keys according to @var{policy}, which may be one
6655 Always download missing OpenPGP keys from the key server, and add them
6656 to the user's GnuPG keyring.
6659 Never try to download missing OpenPGP keys. Instead just bail out.
6662 When a package signed with an unknown OpenPGP key is encountered, ask
6663 the user whether to download it or not. This is the default behavior.
6666 @item --key-server=@var{host}
6667 Use @var{host} as the OpenPGP key server when importing a public key.
6671 The @code{github} updater uses the
6672 @uref{https://developer.github.com/v3/, GitHub API} to query for new
6673 releases. When used repeatedly e.g. when refreshing all packages,
6674 GitHub will eventually refuse to answer any further API requests. By
6675 default 60 API requests per hour are allowed, and a full refresh on all
6676 GitHub packages in Guix requires more than this. Authentication with
6677 GitHub through the use of an API token alleviates these limits. To use
6678 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
6679 token procured from @uref{https://github.com/settings/tokens} or
6683 @node Invoking guix lint
6684 @section Invoking @command{guix lint}
6686 @cindex @command{guix lint}
6687 @cindex package, checking for errors
6688 The @command{guix lint} command is meant to help package developers avoid
6689 common errors and use a consistent style. It runs a number of checks on
6690 a given set of packages in order to find common mistakes in their
6691 definitions. Available @dfn{checkers} include (see
6692 @code{--list-checkers} for a complete list):
6697 Validate certain typographical and stylistic rules about package
6698 descriptions and synopses.
6700 @item inputs-should-be-native
6701 Identify inputs that should most likely be native inputs.
6706 @itemx source-file-name
6707 Probe @code{home-page} and @code{source} URLs and report those that are
6708 invalid. Suggest a @code{mirror://} URL when applicable. Check that
6709 the source file name is meaningful, e.g. is not
6710 just a version number or ``git-checkout'', without a declared
6711 @code{file-name} (@pxref{origin Reference}).
6714 @cindex security vulnerabilities
6715 @cindex CVE, Common Vulnerabilities and Exposures
6716 Report known vulnerabilities found in the Common Vulnerabilities and
6717 Exposures (CVE) databases of the current and past year
6718 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
6721 To view information about a particular vulnerability, visit pages such as:
6725 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
6727 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
6731 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
6732 @code{CVE-2015-7554}.
6734 Package developers can specify in package recipes the
6735 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
6736 name and version of the package when they differ from the name that Guix
6737 uses, as in this example:
6743 ;; CPE calls this package "grub2".
6744 (properties '((cpe-name . "grub2"))))
6748 Warn about obvious source code formatting issues: trailing white space,
6749 use of tabulations, etc.
6752 The general syntax is:
6755 guix lint @var{options} @var{package}@dots{}
6758 If no package is given on the command line, then all packages are checked.
6759 The @var{options} may be zero or more of the following:
6762 @item --list-checkers
6764 List and describe all the available checkers that will be run on packages
6769 Only enable the checkers specified in a comma-separated list using the
6770 names returned by @code{--list-checkers}.
6774 @node Invoking guix size
6775 @section Invoking @command{guix size}
6778 @cindex package size
6780 @cindex @command{guix size}
6781 The @command{guix size} command helps package developers profile the
6782 disk usage of packages. It is easy to overlook the impact of an
6783 additional dependency added to a package, or the impact of using a
6784 single output for a package that could easily be split (@pxref{Packages
6785 with Multiple Outputs}). Such are the typical issues that
6786 @command{guix size} can highlight.
6788 The command can be passed a package specification such as @code{gcc@@4.8}
6789 or @code{guile:debug}, or a file name in the store. Consider this
6793 $ guix size coreutils
6794 store item total self
6795 /gnu/store/@dots{}-coreutils-8.23 70.0 13.9 19.8%
6796 /gnu/store/@dots{}-gmp-6.0.0a 55.3 2.5 3.6%
6797 /gnu/store/@dots{}-acl-2.2.52 53.7 0.5 0.7%
6798 /gnu/store/@dots{}-attr-2.4.46 53.2 0.3 0.5%
6799 /gnu/store/@dots{}-gcc-4.8.4-lib 52.9 15.7 22.4%
6800 /gnu/store/@dots{}-glibc-2.21 37.2 37.2 53.1%
6804 The store items listed here constitute the @dfn{transitive closure} of
6805 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
6806 would be returned by:
6809 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
6812 Here the output shows three columns next to store items. The first column,
6813 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
6814 the store item---that is, its own size plus the size of all its
6815 dependencies. The next column, labeled ``self'', shows the size of the
6816 item itself. The last column shows the ratio of the size of the item
6817 itself to the space occupied by all the items listed here.
6819 In this example, we see that the closure of Coreutils weighs in at
6820 70@tie{}MiB, half of which is taken by libc. (That libc represents a
6821 large fraction of the closure is not a problem @i{per se} because it is
6822 always available on the system anyway.)
6824 When the package passed to @command{guix size} is available in the
6825 store, @command{guix size} queries the daemon to determine its
6826 dependencies, and measures its size in the store, similar to @command{du
6827 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
6830 When the given package is @emph{not} in the store, @command{guix size}
6831 reports information based on the available substitutes
6832 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
6833 store items that are not even on disk, only available remotely.
6835 You can also specify several package names:
6838 $ guix size coreutils grep sed bash
6839 store item total self
6840 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
6841 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
6842 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
6843 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
6849 In this example we see that the combination of the four packages takes
6850 102.3@tie{}MiB in total, which is much less than the sum of each closure
6851 since they have a lot of dependencies in common.
6853 The available options are:
6857 @item --substitute-urls=@var{urls}
6858 Use substitute information from @var{urls}.
6859 @xref{client-substitute-urls, the same option for @code{guix build}}.
6861 @item --sort=@var{key}
6862 Sort lines according to @var{key}, one of the following options:
6866 the size of each item (the default);
6868 the total size of the item's closure.
6871 @item --map-file=@var{file}
6872 Write a graphical map of disk usage in PNG format to @var{file}.
6874 For the example above, the map looks like this:
6876 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
6877 produced by @command{guix size}}
6879 This option requires that
6880 @uref{http://wingolog.org/software/guile-charting/, Guile-Charting} be
6881 installed and visible in Guile's module search path. When that is not
6882 the case, @command{guix size} fails as it tries to load it.
6884 @item --system=@var{system}
6885 @itemx -s @var{system}
6886 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
6890 @node Invoking guix graph
6891 @section Invoking @command{guix graph}
6894 @cindex @command{guix graph}
6895 @cindex package dependencies
6896 Packages and their dependencies form a @dfn{graph}, specifically a
6897 directed acyclic graph (DAG). It can quickly become difficult to have a
6898 mental model of the package DAG, so the @command{guix graph} command
6899 provides a visual representation of the DAG. By default,
6900 @command{guix graph} emits a DAG representation in the input format of
6901 @uref{http://www.graphviz.org/, Graphviz}, so its output can be passed
6902 directly to the @command{dot} command of Graphviz. It can also emit an
6903 HTML page with embedded JavaScript code to display a ``chord diagram''
6904 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
6905 emit Cypher queries to construct a graph in a graph database supporting
6906 the @uref{http://www.opencypher.org/, openCypher} query language.
6907 The general syntax is:
6910 guix graph @var{options} @var{package}@dots{}
6913 For example, the following command generates a PDF file representing the
6914 package DAG for the GNU@tie{}Core Utilities, showing its build-time
6918 guix graph coreutils | dot -Tpdf > dag.pdf
6921 The output looks like this:
6923 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
6925 Nice little graph, no?
6927 But there is more than one graph! The one above is concise: it is the
6928 graph of package objects, omitting implicit inputs such as GCC, libc,
6929 grep, etc. It is often useful to have such a concise graph, but
6930 sometimes one may want to see more details. @command{guix graph} supports
6931 several types of graphs, allowing you to choose the level of detail:
6935 This is the default type used in the example above. It shows the DAG of
6936 package objects, excluding implicit dependencies. It is concise, but
6937 filters out many details.
6939 @item reverse-package
6940 This shows the @emph{reverse} DAG of packages. For example:
6943 guix graph --type=reverse-package ocaml
6946 ... yields the graph of packages that depend on OCaml.
6948 Note that for core packages this can yield huge graphs. If all you want
6949 is to know the number of packages that depend on a given package, use
6950 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
6951 @option{--list-dependent}}).
6954 This is the package DAG, @emph{including} implicit inputs.
6956 For instance, the following command:
6959 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
6962 ... yields this bigger graph:
6964 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
6966 At the bottom of the graph, we see all the implicit inputs of
6967 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
6969 Now, note that the dependencies of these implicit inputs---that is, the
6970 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
6971 here, for conciseness.
6974 Similar to @code{bag-emerged}, but this time including all the bootstrap
6977 @item bag-with-origins
6978 Similar to @code{bag}, but also showing origins and their dependencies.
6981 This is the most detailed representation: It shows the DAG of
6982 derivations (@pxref{Derivations}) and plain store items. Compared to
6983 the above representation, many additional nodes are visible, including
6984 build scripts, patches, Guile modules, etc.
6986 For this type of graph, it is also possible to pass a @file{.drv} file
6987 name instead of a package name, as in:
6990 guix graph -t derivation `guix system build -d my-config.scm`
6994 All the types above correspond to @emph{build-time dependencies}. The
6995 following graph type represents the @emph{run-time dependencies}:
6999 This is the graph of @dfn{references} of a package output, as returned
7000 by @command{guix gc --references} (@pxref{Invoking guix gc}).
7002 If the given package output is not available in the store, @command{guix
7003 graph} attempts to obtain dependency information from substitutes.
7005 Here you can also pass a store file name instead of a package name. For
7006 example, the command below produces the reference graph of your profile
7007 (which can be big!):
7010 guix graph -t references `readlink -f ~/.guix-profile`
7014 This is the graph of the @dfn{referrers} of a store item, as returned by
7015 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
7017 This relies exclusively on local information from your store. For
7018 instance, let us suppose that the current Inkscape is available in 10
7019 profiles on your machine; @command{guix graph -t referrers inkscape}
7020 will show a graph rooted at Inkscape and with those 10 profiles linked
7023 It can help determine what is preventing a store item from being garbage
7028 The available options are the following:
7031 @item --type=@var{type}
7032 @itemx -t @var{type}
7033 Produce a graph output of @var{type}, where @var{type} must be one of
7034 the values listed above.
7037 List the supported graph types.
7039 @item --backend=@var{backend}
7040 @itemx -b @var{backend}
7041 Produce a graph using the selected @var{backend}.
7043 @item --list-backends
7044 List the supported graph backends.
7046 Currently, the available backends are Graphviz and d3.js.
7048 @item --expression=@var{expr}
7049 @itemx -e @var{expr}
7050 Consider the package @var{expr} evaluates to.
7052 This is useful to precisely refer to a package, as in this example:
7055 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
7060 @node Invoking guix environment
7061 @section Invoking @command{guix environment}
7063 @cindex reproducible build environments
7064 @cindex development environments
7065 @cindex @command{guix environment}
7066 @cindex environment, package build environment
7067 The purpose of @command{guix environment} is to assist hackers in
7068 creating reproducible development environments without polluting their
7069 package profile. The @command{guix environment} tool takes one or more
7070 packages, builds all of their inputs, and creates a shell
7071 environment to use them.
7073 The general syntax is:
7076 guix environment @var{options} @var{package}@dots{}
7079 The following example spawns a new shell set up for the development of
7083 guix environment guile
7086 If the needed dependencies are not built yet, @command{guix environment}
7087 automatically builds them. The environment of the new shell is an augmented
7088 version of the environment that @command{guix environment} was run in.
7089 It contains the necessary search paths for building the given package
7090 added to the existing environment variables. To create a ``pure''
7091 environment, in which the original environment variables have been unset,
7092 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
7093 environment variables such as @code{PATH} in their @file{~/.bashrc}
7094 file. As a consequence, when @code{guix environment} launches it, Bash
7095 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
7096 environment variables. It is an error to define such environment
7097 variables in @file{.bashrc}; instead, they should be defined in
7098 @file{.bash_profile}, which is sourced only by log-in shells.
7099 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
7100 details on Bash start-up files.}.
7102 @vindex GUIX_ENVIRONMENT
7103 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
7104 variable in the shell it spawns; its value is the file name of the
7105 profile of this environment. This allows users to, say, define a
7106 specific prompt for development environments in their @file{.bashrc}
7107 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
7110 if [ -n "$GUIX_ENVIRONMENT" ]
7112 export PS1="\u@@\h \w [dev]\$ "
7117 ... or to browse the profile:
7120 $ ls "$GUIX_ENVIRONMENT/bin"
7123 Additionally, more than one package may be specified, in which case the
7124 union of the inputs for the given packages are used. For example, the
7125 command below spawns a shell where all of the dependencies of both Guile
7126 and Emacs are available:
7129 guix environment guile emacs
7132 Sometimes an interactive shell session is not desired. An arbitrary
7133 command may be invoked by placing the @code{--} token to separate the
7134 command from the rest of the arguments:
7137 guix environment guile -- make -j4
7140 In other situations, it is more convenient to specify the list of
7141 packages needed in the environment. For example, the following command
7142 runs @command{python} from an environment containing Python@tie{}2.7 and
7146 guix environment --ad-hoc python2-numpy python-2.7 -- python
7149 Furthermore, one might want the dependencies of a package and also some
7150 additional packages that are not build-time or runtime dependencies, but
7151 are useful when developing nonetheless. Because of this, the
7152 @code{--ad-hoc} flag is positional. Packages appearing before
7153 @code{--ad-hoc} are interpreted as packages whose dependencies will be
7154 added to the environment. Packages appearing after are interpreted as
7155 packages that will be added to the environment directly. For example,
7156 the following command creates a Guix development environment that
7157 additionally includes Git and strace:
7160 guix environment guix --ad-hoc git strace
7163 Sometimes it is desirable to isolate the environment as much as
7164 possible, for maximal purity and reproducibility. In particular, when
7165 using Guix on a host distro that is not GuixSD, it is desirable to
7166 prevent access to @file{/usr/bin} and other system-wide resources from
7167 the development environment. For example, the following command spawns
7168 a Guile REPL in a ``container'' where only the store and the current
7169 working directory are mounted:
7172 guix environment --ad-hoc --container guile -- guile
7176 The @code{--container} option requires Linux-libre 3.19 or newer.
7179 The available options are summarized below.
7182 @item --root=@var{file}
7183 @itemx -r @var{file}
7184 @cindex persistent environment
7185 @cindex garbage collector root, for environments
7186 Make @var{file} a symlink to the profile for this environment, and
7187 register it as a garbage collector root.
7189 This is useful if you want to protect your environment from garbage
7190 collection, to make it ``persistent''.
7192 When this option is omitted, the environment is protected from garbage
7193 collection only for the duration of the @command{guix environment}
7194 session. This means that next time you recreate the same environment,
7195 you could have to rebuild or re-download packages. @xref{Invoking guix
7196 gc}, for more on GC roots.
7198 @item --expression=@var{expr}
7199 @itemx -e @var{expr}
7200 Create an environment for the package or list of packages that
7201 @var{expr} evaluates to.
7203 For example, running:
7206 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
7209 starts a shell with the environment for this specific variant of the
7215 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
7218 starts a shell with all the GuixSD base packages available.
7220 The above commands only use the default output of the given packages.
7221 To select other outputs, two element tuples can be specified:
7224 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
7227 @item --load=@var{file}
7228 @itemx -l @var{file}
7229 Create an environment for the package or list of packages that the code
7230 within @var{file} evaluates to.
7232 As an example, @var{file} might contain a definition like this
7233 (@pxref{Defining Packages}):
7236 @verbatiminclude environment-gdb.scm
7239 @item --manifest=@var{file}
7240 @itemx -m @var{file}
7241 Create an environment for the packages contained in the manifest object
7242 returned by the Scheme code in @var{file}.
7244 This is similar to the same-named option in @command{guix package}
7245 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
7249 Include all specified packages in the resulting environment, as if an
7250 @i{ad hoc} package were defined with them as inputs. This option is
7251 useful for quickly creating an environment without having to write a
7252 package expression to contain the desired inputs.
7254 For instance, the command:
7257 guix environment --ad-hoc guile guile-sdl -- guile
7260 runs @command{guile} in an environment where Guile and Guile-SDL are
7263 Note that this example implicitly asks for the default output of
7264 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
7265 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
7266 of @code{glib} (@pxref{Packages with Multiple Outputs}).
7268 This option may be composed with the default behavior of @command{guix
7269 environment}. Packages appearing before @code{--ad-hoc} are interpreted
7270 as packages whose dependencies will be added to the environment, the
7271 default behavior. Packages appearing after are interpreted as packages
7272 that will be added to the environment directly.
7275 Unset existing environment variables when building the new environment.
7276 This has the effect of creating an environment in which search paths
7277 only contain package inputs.
7279 @item --search-paths
7280 Display the environment variable definitions that make up the
7283 @item --system=@var{system}
7284 @itemx -s @var{system}
7285 Attempt to build for @var{system}---e.g., @code{i686-linux}.
7290 Run @var{command} within an isolated container. The current working
7291 directory outside the container is mapped inside the container.
7292 Additionally, unless overridden with @code{--user}, a dummy home
7293 directory is created that matches the current user's home directory, and
7294 @file{/etc/passwd} is configured accordingly. The spawned process runs
7295 as the current user outside the container, but has root privileges in
7296 the context of the container.
7300 For containers, share the network namespace with the host system.
7301 Containers created without this flag only have access to the loopback
7304 @item --link-profile
7306 For containers, link the environment profile to
7307 @file{~/.guix-profile} within the container. This is equivalent to
7308 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
7309 within the container. Linking will fail and abort the environment if
7310 the directory already exists, which will certainly be the case if
7311 @command{guix environment} was invoked in the user's home directory.
7313 Certain packages are configured to look in
7314 @code{~/.guix-profile} for configuration files and data;@footnote{For
7315 example, the @code{fontconfig} package inspects
7316 @file{~/.guix-profile/share/fonts} for additional fonts.}
7317 @code{--link-profile} allows these programs to behave as expected within
7320 @item --user=@var{user}
7321 @itemx -u @var{user}
7322 For containers, use the username @var{user} in place of the current
7323 user. The generated @file{/etc/passwd} entry within the container will
7324 contain the name @var{user}; the home directory will be
7325 @file{/home/USER}; and no user GECOS data will be copied. @var{user}
7326 need not exist on the system.
7328 Additionally, any shared or exposed path (see @code{--share} and
7329 @code{--expose} respectively) whose target is within the current user's
7330 home directory will be remapped relative to @file{/home/USER}; this
7331 includes the automatic mapping of the current working directory.
7334 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
7336 guix environment --container --user=foo \
7337 --expose=$HOME/test \
7338 --expose=/tmp/target=$HOME/target
7341 While this will limit the leaking of user identity through home paths
7342 and each of the user fields, this is only one useful component of a
7343 broader privacy/anonymity solution---not one in and of itself.
7345 @item --expose=@var{source}[=@var{target}]
7346 For containers, expose the file system @var{source} from the host system
7347 as the read-only file system @var{target} within the container. If
7348 @var{target} is not specified, @var{source} is used as the target mount
7349 point in the container.
7351 The example below spawns a Guile REPL in a container in which the user's
7352 home directory is accessible read-only via the @file{/exchange}
7356 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
7359 @item --share=@var{source}[=@var{target}]
7360 For containers, share the file system @var{source} from the host system
7361 as the writable file system @var{target} within the container. If
7362 @var{target} is not specified, @var{source} is used as the target mount
7363 point in the container.
7365 The example below spawns a Guile REPL in a container in which the user's
7366 home directory is accessible for both reading and writing via the
7367 @file{/exchange} directory:
7370 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
7374 @command{guix environment}
7375 also supports all of the common build options that @command{guix
7376 build} supports (@pxref{Common Build Options}).
7379 @node Invoking guix publish
7380 @section Invoking @command{guix publish}
7382 @cindex @command{guix publish}
7383 The purpose of @command{guix publish} is to enable users to easily share
7384 their store with others, who can then use it as a substitute server
7385 (@pxref{Substitutes}).
7387 When @command{guix publish} runs, it spawns an HTTP server which allows
7388 anyone with network access to obtain substitutes from it. This means
7389 that any machine running Guix can also act as if it were a build farm,
7390 since the HTTP interface is compatible with Hydra, the software behind
7391 the @code{hydra.gnu.org} build farm.
7393 For security, each substitute is signed, allowing recipients to check
7394 their authenticity and integrity (@pxref{Substitutes}). Because
7395 @command{guix publish} uses the signing key of the system, which is only
7396 readable by the system administrator, it must be started as root; the
7397 @code{--user} option makes it drop root privileges early on.
7399 The signing key pair must be generated before @command{guix publish} is
7400 launched, using @command{guix archive --generate-key} (@pxref{Invoking
7403 The general syntax is:
7406 guix publish @var{options}@dots{}
7409 Running @command{guix publish} without any additional arguments will
7410 spawn an HTTP server on port 8080:
7416 Once a publishing server has been authorized (@pxref{Invoking guix
7417 archive}), the daemon may download substitutes from it:
7420 guix-daemon --substitute-urls=http://example.org:8080
7423 By default, @command{guix publish} compresses archives on the fly as it
7424 serves them. This ``on-the-fly'' mode is convenient in that it requires
7425 no setup and is immediately available. However, when serving lots of
7426 clients, we recommend using the @option{--cache} option, which enables
7427 caching of the archives before they are sent to clients---see below for
7428 details. The @command{guix weather} command provides a handy way to
7429 check what a server provides (@pxref{Invoking guix weather}).
7431 As a bonus, @command{guix publish} also serves as a content-addressed
7432 mirror for source files referenced in @code{origin} records
7433 (@pxref{origin Reference}). For instance, assuming @command{guix
7434 publish} is running on @code{example.org}, the following URL returns the
7435 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
7436 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
7439 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
7442 Obviously, these URLs only work for files that are in the store; in
7443 other cases, they return 404 (``Not Found'').
7445 @cindex build logs, publication
7446 Build logs are available from @code{/log} URLs like:
7449 http://example.org/log/gwspk@dots{}-guile-2.2.3
7453 When @command{guix-daemon} is configured to save compressed build logs,
7454 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
7455 URLs return the compressed log as-is, with an appropriate
7456 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
7457 running @command{guix-daemon} with @code{--log-compression=gzip} since
7458 Web browsers can automatically decompress it, which is not the case with
7461 The following options are available:
7464 @item --port=@var{port}
7465 @itemx -p @var{port}
7466 Listen for HTTP requests on @var{port}.
7468 @item --listen=@var{host}
7469 Listen on the network interface for @var{host}. The default is to
7470 accept connections from any interface.
7472 @item --user=@var{user}
7473 @itemx -u @var{user}
7474 Change privileges to @var{user} as soon as possible---i.e., once the
7475 server socket is open and the signing key has been read.
7477 @item --compression[=@var{level}]
7478 @itemx -C [@var{level}]
7479 Compress data using the given @var{level}. When @var{level} is zero,
7480 disable compression. The range 1 to 9 corresponds to different gzip
7481 compression levels: 1 is the fastest, and 9 is the best (CPU-intensive).
7484 Unless @option{--cache} is used, compression occurs on the fly and
7485 the compressed streams are not
7486 cached. Thus, to reduce load on the machine that runs @command{guix
7487 publish}, it may be a good idea to choose a low compression level, to
7488 run @command{guix publish} behind a caching proxy, or to use
7489 @option{--cache}. Using @option{--cache} has the advantage that it
7490 allows @command{guix publish} to add @code{Content-Length} HTTP header
7493 @item --cache=@var{directory}
7494 @itemx -c @var{directory}
7495 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
7496 and only serve archives that are in cache.
7498 When this option is omitted, archives and meta-data are created
7499 on-the-fly. This can reduce the available bandwidth, especially when
7500 compression is enabled, since this may become CPU-bound. Another
7501 drawback of the default mode is that the length of archives is not known
7502 in advance, so @command{guix publish} does not add a
7503 @code{Content-Length} HTTP header to its responses, which in turn
7504 prevents clients from knowing the amount of data being downloaded.
7506 Conversely, when @option{--cache} is used, the first request for a store
7507 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
7508 background process to @dfn{bake} the archive---computing its
7509 @code{.narinfo} and compressing the archive, if needed. Once the
7510 archive is cached in @var{directory}, subsequent requests succeed and
7511 are served directly from the cache, which guarantees that clients get
7512 the best possible bandwidth.
7514 The ``baking'' process is performed by worker threads. By default, one
7515 thread per CPU core is created, but this can be customized. See
7516 @option{--workers} below.
7518 When @option{--ttl} is used, cached entries are automatically deleted
7519 when they have expired.
7521 @item --workers=@var{N}
7522 When @option{--cache} is used, request the allocation of @var{N} worker
7523 threads to ``bake'' archives.
7525 @item --ttl=@var{ttl}
7526 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
7527 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
7528 days, @code{1m} means 1 month, and so on.
7530 This allows the user's Guix to keep substitute information in cache for
7531 @var{ttl}. However, note that @code{guix publish} does not itself
7532 guarantee that the store items it provides will indeed remain available
7533 for as long as @var{ttl}.
7535 Additionally, when @option{--cache} is used, cached entries that have
7536 not been accessed for @var{ttl} and that no longer have a corresponding
7537 item in the store, may be deleted.
7539 @item --nar-path=@var{path}
7540 Use @var{path} as the prefix for the URLs of ``nar'' files
7541 (@pxref{Invoking guix archive, normalized archives}).
7543 By default, nars are served at a URL such as
7544 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
7545 change the @code{/nar} part to @var{path}.
7547 @item --public-key=@var{file}
7548 @itemx --private-key=@var{file}
7549 Use the specific @var{file}s as the public/private key pair used to sign
7550 the store items being published.
7552 The files must correspond to the same key pair (the private key is used
7553 for signing and the public key is merely advertised in the signature
7554 metadata). They must contain keys in the canonical s-expression format
7555 as produced by @command{guix archive --generate-key} (@pxref{Invoking
7556 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
7557 @file{/etc/guix/signing-key.sec} are used.
7559 @item --repl[=@var{port}]
7560 @itemx -r [@var{port}]
7561 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
7562 Reference Manual}) on @var{port} (37146 by default). This is used
7563 primarily for debugging a running @command{guix publish} server.
7566 Enabling @command{guix publish} on a GuixSD system is a one-liner: just
7567 instantiate a @code{guix-publish-service-type} service in the @code{services} field
7568 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
7569 @code{guix-publish-service-type}}).
7571 If you are instead running Guix on a ``foreign distro'', follow these
7576 If your host distro uses the systemd init system:
7579 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
7580 /etc/systemd/system/
7581 # systemctl start guix-publish && systemctl enable guix-publish
7585 If your host distro uses the Upstart init system:
7588 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
7589 # start guix-publish
7593 Otherwise, proceed similarly with your distro's init system.
7596 @node Invoking guix challenge
7597 @section Invoking @command{guix challenge}
7599 @cindex reproducible builds
7600 @cindex verifiable builds
7601 @cindex @command{guix challenge}
7603 Do the binaries provided by this server really correspond to the source
7604 code it claims to build? Is a package build process deterministic?
7605 These are the questions the @command{guix challenge} command attempts to
7608 The former is obviously an important question: Before using a substitute
7609 server (@pxref{Substitutes}), one had better @emph{verify} that it
7610 provides the right binaries, and thus @emph{challenge} it. The latter
7611 is what enables the former: If package builds are deterministic, then
7612 independent builds of the package should yield the exact same result,
7613 bit for bit; if a server provides a binary different from the one
7614 obtained locally, it may be either corrupt or malicious.
7616 We know that the hash that shows up in @file{/gnu/store} file names is
7617 the hash of all the inputs of the process that built the file or
7618 directory---compilers, libraries, build scripts,
7619 etc. (@pxref{Introduction}). Assuming deterministic build processes,
7620 one store file name should map to exactly one build output.
7621 @command{guix challenge} checks whether there is, indeed, a single
7622 mapping by comparing the build outputs of several independent builds of
7623 any given store item.
7625 The command output looks like this:
7628 $ guix challenge --substitute-urls="https://hydra.gnu.org https://guix.example.org"
7629 updating list of substitutes from 'https://hydra.gnu.org'... 100.0%
7630 updating list of substitutes from 'https://guix.example.org'... 100.0%
7631 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
7632 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
7633 https://hydra.gnu.org/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
7634 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
7635 /gnu/store/@dots{}-git-2.5.0 contents differ:
7636 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
7637 https://hydra.gnu.org/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
7638 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
7639 /gnu/store/@dots{}-pius-2.1.1 contents differ:
7640 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
7641 https://hydra.gnu.org/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
7642 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
7646 6,406 store items were analyzed:
7647 - 4,749 (74.1%) were identical
7648 - 525 (8.2%) differed
7649 - 1,132 (17.7%) were inconclusive
7653 In this example, @command{guix challenge} first scans the store to
7654 determine the set of locally-built derivations---as opposed to store
7655 items that were downloaded from a substitute server---and then queries
7656 all the substitute servers. It then reports those store items for which
7657 the servers obtained a result different from the local build.
7659 @cindex non-determinism, in package builds
7660 As an example, @code{guix.example.org} always gets a different answer.
7661 Conversely, @code{hydra.gnu.org} agrees with local builds, except in the
7662 case of Git. This might indicate that the build process of Git is
7663 non-deterministic, meaning that its output varies as a function of
7664 various things that Guix does not fully control, in spite of building
7665 packages in isolated environments (@pxref{Features}). Most common
7666 sources of non-determinism include the addition of timestamps in build
7667 results, the inclusion of random numbers, and directory listings sorted
7668 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
7671 To find out what is wrong with this Git binary, we can do something along
7672 these lines (@pxref{Invoking guix archive}):
7675 $ wget -q -O - https://hydra.gnu.org/nar/@dots{}-git-2.5.0 \
7676 | guix archive -x /tmp/git
7677 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
7680 This command shows the difference between the files resulting from the
7681 local build, and the files resulting from the build on
7682 @code{hydra.gnu.org} (@pxref{Overview, Comparing and Merging Files,,
7683 diffutils, Comparing and Merging Files}). The @command{diff} command
7684 works great for text files. When binary files differ, a better option
7685 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
7686 visualize differences for all kinds of files.
7688 Once you have done that work, you can tell whether the differences are due
7689 to a non-deterministic build process or to a malicious server. We try
7690 hard to remove sources of non-determinism in packages to make it easier
7691 to verify substitutes, but of course, this is a process that
7692 involves not just Guix, but a large part of the free software community.
7693 In the meantime, @command{guix challenge} is one tool to help address
7696 If you are writing packages for Guix, you are encouraged to check
7697 whether @code{hydra.gnu.org} and other substitute servers obtain the
7698 same build result as you did with:
7701 $ guix challenge @var{package}
7705 where @var{package} is a package specification such as
7706 @code{guile@@2.0} or @code{glibc:debug}.
7708 The general syntax is:
7711 guix challenge @var{options} [@var{packages}@dots{}]
7714 When a difference is found between the hash of a locally-built item and
7715 that of a server-provided substitute, or among substitutes provided by
7716 different servers, the command displays it as in the example above and
7717 its exit code is 2 (other non-zero exit codes denote other kinds of
7720 The one option that matters is:
7724 @item --substitute-urls=@var{urls}
7725 Consider @var{urls} the whitespace-separated list of substitute source
7730 Show details about matches (identical contents) in addition to
7731 information about mismatches.
7735 @node Invoking guix copy
7736 @section Invoking @command{guix copy}
7738 @cindex copy, of store items, over SSH
7739 @cindex SSH, copy of store items
7740 @cindex sharing store items across machines
7741 @cindex transferring store items across machines
7742 The @command{guix copy} command copies items from the store of one
7743 machine to that of another machine over a secure shell (SSH)
7744 connection@footnote{This command is available only when Guile-SSH was
7745 found. @xref{Requirements}, for details.}. For example, the following
7746 command copies the @code{coreutils} package, the user's profile, and all
7747 their dependencies over to @var{host}, logged in as @var{user}:
7750 guix copy --to=@var{user}@@@var{host} \
7751 coreutils `readlink -f ~/.guix-profile`
7754 If some of the items to be copied are already present on @var{host},
7755 they are not actually sent.
7757 The command below retrieves @code{libreoffice} and @code{gimp} from
7758 @var{host}, assuming they are available there:
7761 guix copy --from=@var{host} libreoffice gimp
7764 The SSH connection is established using the Guile-SSH client, which is
7765 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
7766 @file{~/.ssh/config}, and uses the SSH agent for authentication.
7768 The key used to sign items that are sent must be accepted by the remote
7769 machine. Likewise, the key used by the remote machine to sign items you
7770 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
7771 own daemon. @xref{Invoking guix archive}, for more information about
7772 store item authentication.
7774 The general syntax is:
7777 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
7780 You must always specify one of the following options:
7783 @item --to=@var{spec}
7784 @itemx --from=@var{spec}
7785 Specify the host to send to or receive from. @var{spec} must be an SSH
7786 spec such as @code{example.org}, @code{charlie@@example.org}, or
7787 @code{charlie@@example.org:2222}.
7790 The @var{items} can be either package names, such as @code{gimp}, or
7791 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
7793 When specifying the name of a package to send, it is first built if
7794 needed, unless @option{--dry-run} was specified. Common build options
7795 are supported (@pxref{Common Build Options}).
7798 @node Invoking guix container
7799 @section Invoking @command{guix container}
7801 @cindex @command{guix container}
7803 As of version @value{VERSION}, this tool is experimental. The interface
7804 is subject to radical change in the future.
7807 The purpose of @command{guix container} is to manipulate processes
7808 running within an isolated environment, commonly known as a
7809 ``container'', typically created by the @command{guix environment}
7810 (@pxref{Invoking guix environment}) and @command{guix system container}
7811 (@pxref{Invoking guix system}) commands.
7813 The general syntax is:
7816 guix container @var{action} @var{options}@dots{}
7819 @var{action} specifies the operation to perform with a container, and
7820 @var{options} specifies the context-specific arguments for the action.
7822 The following actions are available:
7826 Execute a command within the context of a running container.
7831 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
7834 @var{pid} specifies the process ID of the running container.
7835 @var{program} specifies an executable file name within the root file
7836 system of the container. @var{arguments} are the additional options that
7837 will be passed to @var{program}.
7839 The following command launches an interactive login shell inside a
7840 GuixSD container, started by @command{guix system container}, and whose
7844 guix container exec 9001 /run/current-system/profile/bin/bash --login
7847 Note that the @var{pid} cannot be the parent process of a container. It
7848 must be PID 1 of the container or one of its child processes.
7852 @node Invoking guix weather
7853 @section Invoking @command{guix weather}
7855 Occasionally you're grumpy because substitutes are lacking and you end
7856 up building packages by yourself (@pxref{Substitutes}). The
7857 @command{guix weather} command reports on substitute availability on the
7858 specified servers so you can have an idea of whether you'll be grumpy
7859 today. It can sometimes be useful info as a user, but it is primarily
7860 useful to people running @command{guix publish} (@pxref{Invoking guix
7863 @cindex statistics, for substitutes
7864 @cindex availability of substitutes
7865 @cindex substitute availability
7866 @cindex weather, substitute availability
7867 Here's a sample run:
7870 $ guix weather --substitute-urls=https://guix.example.org
7871 computing 5,872 package derivations for x86_64-linux...
7872 looking for 6,128 store items on https://guix.example.org..
7873 updating list of substitutes from 'https://guix.example.org'... 100.0%
7874 https://guix.example.org
7875 43.4% substitutes available (2,658 out of 6,128)
7876 7,032.5 MiB of nars (compressed)
7877 19,824.2 MiB on disk (uncompressed)
7878 0.030 seconds per request (182.9 seconds in total)
7879 33.5 requests per second
7882 As you can see, it reports the fraction of all the packages for which
7883 substitutes are available on the server---regardless of whether
7884 substitutes are enabled, and regardless of whether this server's signing
7885 key is authorized. It also reports the size of the compressed archives
7886 (``nars'') provided by the server, the size the corresponding store
7887 items occupy in the store (assuming deduplication is turned off), and
7888 the server's throughput.
7890 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
7891 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
7892 challenge}, it ignores signatures on those substitutes, which is
7893 innocuous since the command only gathers statistics and cannot install
7896 Among other things, it is possible to query specific system types and
7897 specific package sets. The available options are listed below.
7900 @item --substitute-urls=@var{urls}
7901 @var{urls} is the space-separated list of substitute server URLs to
7902 query. When this option is omitted, the default set of substitute
7905 @item --system=@var{system}
7906 @itemx -s @var{system}
7907 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
7908 option can be repeated, in which case @command{guix weather} will query
7909 substitutes for several system types.
7911 @item --manifest=@var{file}
7912 Instead of querying substitutes for all the packages, only ask for those
7913 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
7914 with the @code{-m} option of @command{guix package} (@pxref{Invoking
7919 @c *********************************************************************
7920 @node GNU Distribution
7921 @chapter GNU Distribution
7923 @cindex Guix System Distribution
7925 Guix comes with a distribution of the GNU system consisting entirely of
7926 free software@footnote{The term ``free'' here refers to the
7927 @url{http://www.gnu.org/philosophy/free-sw.html,freedom provided to
7928 users of that software}.}. The
7929 distribution can be installed on its own (@pxref{System Installation}),
7930 but it is also possible to install Guix as a package manager on top of
7931 an installed GNU/Linux system (@pxref{Installation}). To distinguish
7932 between the two, we refer to the standalone distribution as the Guix
7933 System Distribution, or GuixSD.
7935 The distribution provides core GNU packages such as GNU libc, GCC, and
7936 Binutils, as well as many GNU and non-GNU applications. The complete
7937 list of available packages can be browsed
7938 @url{http://www.gnu.org/software/guix/packages,on-line} or by
7939 running @command{guix package} (@pxref{Invoking guix package}):
7942 guix package --list-available
7945 Our goal is to provide a practical 100% free software distribution of
7946 Linux-based and other variants of GNU, with a focus on the promotion and
7947 tight integration of GNU components, and an emphasis on programs and
7948 tools that help users exert that freedom.
7950 Packages are currently available on the following platforms:
7955 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
7958 Intel 32-bit architecture (IA32), Linux-Libre kernel;
7961 ARMv7-A architecture with hard float, Thumb-2 and NEON,
7962 using the EABI hard-float application binary interface (ABI),
7963 and Linux-Libre kernel.
7966 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel. This is
7967 currently in an experimental stage, with limited support.
7968 @xref{Contributing}, for how to help!
7970 @item mips64el-linux
7971 little-endian 64-bit MIPS processors, specifically the Loongson series,
7972 n32 ABI, and Linux-Libre kernel.
7976 GuixSD itself is currently only available on @code{i686} and @code{x86_64}.
7979 For information on porting to other architectures or kernels,
7983 * System Installation:: Installing the whole operating system.
7984 * System Configuration:: Configuring the operating system.
7985 * Documentation:: Browsing software user manuals.
7986 * Installing Debugging Files:: Feeding the debugger.
7987 * Security Updates:: Deploying security fixes quickly.
7988 * Package Modules:: Packages from the programmer's viewpoint.
7989 * Packaging Guidelines:: Growing the distribution.
7990 * Bootstrapping:: GNU/Linux built from scratch.
7991 * Porting:: Targeting another platform or kernel.
7994 Building this distribution is a cooperative effort, and you are invited
7995 to join! @xref{Contributing}, for information about how you can help.
7997 @node System Installation
7998 @section System Installation
8000 @cindex installing GuixSD
8001 @cindex Guix System Distribution
8002 This section explains how to install the Guix System Distribution (GuixSD)
8003 on a machine. The Guix package manager can
8004 also be installed on top of a running GNU/Linux system,
8005 @pxref{Installation}.
8009 @c This paragraph is for people reading this from tty2 of the
8010 @c installation image.
8011 You are reading this documentation with an Info reader. For details on
8012 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
8013 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
8014 Info}. Hit @kbd{l} afterwards to come back here.
8016 Alternately, run @command{info info} in another tty to keep the manual
8022 * Limitations:: What you can expect.
8023 * Hardware Considerations:: Supported hardware.
8024 * USB Stick and DVD Installation:: Preparing the installation medium.
8025 * Preparing for Installation:: Networking, partitioning, etc.
8026 * Proceeding with the Installation:: The real thing.
8027 * Installing GuixSD in a VM:: GuixSD playground.
8028 * Building the Installation Image:: How this comes to be.
8032 @subsection Limitations
8034 As of version @value{VERSION}, the Guix System Distribution (GuixSD) is
8035 not production-ready. It may contain bugs and lack important
8036 features. Thus, if you are looking for a stable production system that
8037 respects your freedom as a computer user, a good solution at this point
8038 is to consider @url{http://www.gnu.org/distros/free-distros.html, one of
8039 the more established GNU/Linux distributions}. We hope you can soon switch
8040 to the GuixSD without fear, of course. In the meantime, you can
8041 also keep using your distribution and try out the package manager on top
8042 of it (@pxref{Installation}).
8044 Before you proceed with the installation, be aware of the following
8045 noteworthy limitations applicable to version @value{VERSION}:
8049 The installation process does not include a graphical user interface and
8050 requires familiarity with GNU/Linux (see the following subsections to
8051 get a feel of what that means.)
8054 Support for the Logical Volume Manager (LVM) is missing.
8057 More and more system services are provided (@pxref{Services}), but some
8061 More than 6,500 packages are available, but you might
8062 occasionally find that a useful package is missing.
8065 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
8066 as well as a number of X11 window managers. However, some graphical
8067 applications may be missing, as well as KDE.
8070 You have been warned! But more than a disclaimer, this is an invitation
8071 to report issues (and success stories!), and to join us in improving it.
8072 @xref{Contributing}, for more info.
8075 @node Hardware Considerations
8076 @subsection Hardware Considerations
8078 @cindex hardware support on GuixSD
8079 GNU@tie{}GuixSD focuses on respecting the user's computing freedom. It
8080 builds around the kernel Linux-libre, which means that only hardware for
8081 which free software drivers and firmware exist is supported. Nowadays,
8082 a wide range of off-the-shelf hardware is supported on
8083 GNU/Linux-libre---from keyboards to graphics cards to scanners and
8084 Ethernet controllers. Unfortunately, there are still areas where
8085 hardware vendors deny users control over their own computing, and such
8086 hardware is not supported on GuixSD.
8088 @cindex WiFi, hardware support
8089 One of the main areas where free drivers or firmware are lacking is WiFi
8090 devices. WiFi devices known to work include those using Atheros chips
8091 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
8092 driver, and those using Broadcom/AirForce chips (BCM43xx with
8093 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
8094 Linux-libre driver. Free firmware exists for both and is available
8095 out-of-the-box on GuixSD, as part of @var{%base-firmware}
8096 (@pxref{operating-system Reference, @code{firmware}}).
8098 @cindex RYF, Respects Your Freedom
8099 The @uref{https://www.fsf.org/, Free Software Foundation} runs
8100 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
8101 certification program for hardware products that respect your freedom
8102 and your privacy and ensure that you have control over your device. We
8103 encourage you to check the list of RYF-certified devices.
8105 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
8106 web site. It contains a catalog of hardware devices with information
8107 about their support in GNU/Linux.
8110 @node USB Stick and DVD Installation
8111 @subsection USB Stick and DVD Installation
8113 An ISO-9660 installation image that can be written to a USB stick or
8114 burnt to a DVD can be downloaded from
8115 @indicateurl{ftp://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.iso.xz},
8116 where @var{system} is one of:
8120 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
8123 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
8126 @c start duplication of authentication part from ``Binary Installation''
8127 Make sure to download the associated @file{.sig} file and to verify the
8128 authenticity of the image against it, along these lines:
8131 $ wget ftp://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.iso.xz.sig
8132 $ gpg --verify guixsd-install-@value{VERSION}.@var{system}.iso.xz.sig
8135 If that command fails because you do not have the required public key,
8136 then run this command to import it:
8139 $ gpg --keyserver pgp.mit.edu --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
8143 and rerun the @code{gpg --verify} command.
8146 This image contains the tools necessary for an installation.
8147 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
8149 @unnumberedsubsubsec Copying to a USB Stick
8151 To copy the image to a USB stick, follow these steps:
8155 Decompress the image using the @command{xz} command:
8158 xz -d guixsd-install-@value{VERSION}.@var{system}.iso.xz
8162 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
8163 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
8164 copy the image with:
8167 dd if=guixsd-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX
8171 Access to @file{/dev/sdX} usually requires root privileges.
8174 @unnumberedsubsubsec Burning on a DVD
8176 To copy the image to a DVD, follow these steps:
8180 Decompress the image using the @command{xz} command:
8183 xz -d guixsd-install-@value{VERSION}.@var{system}.iso.xz
8187 Insert a blank DVD into your machine, and determine
8188 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
8189 copy the image with:
8192 growisofs -dvd-compat -Z /dev/srX=guixsd-install-@value{VERSION}.x86_64.iso
8195 Access to @file{/dev/srX} usually requires root privileges.
8198 @unnumberedsubsubsec Booting
8200 Once this is done, you should be able to reboot the system and boot from
8201 the USB stick or DVD. The latter usually requires you to get in the
8202 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
8204 @xref{Installing GuixSD in a VM}, if, instead, you would like to install
8205 GuixSD in a virtual machine (VM).
8208 @node Preparing for Installation
8209 @subsection Preparing for Installation
8211 Once you have successfully booted your computer using the installation medium,
8212 you should end up with a root prompt. Several console TTYs are configured
8213 and can be used to run commands as root. TTY2 shows this documentation,
8214 browsable using the Info reader commands (@pxref{Top,,, info-stnd,
8215 Stand-alone GNU Info}). The installation system runs the GPM mouse
8216 daemon, which allows you to select text with the left mouse button and
8217 to paste it with the middle button.
8220 Installation requires access to the Internet so that any missing
8221 dependencies of your system configuration can be downloaded. See the
8222 ``Networking'' section below.
8225 The installation system includes many common tools needed for this task.
8226 But it is also a full-blown GuixSD system, which means that you can
8227 install additional packages, should you need it, using @command{guix
8228 package} (@pxref{Invoking guix package}).
8230 @subsubsection Keyboard Layout
8232 @cindex keyboard layout
8233 The installation image uses the US qwerty keyboard layout. If you want
8234 to change it, you can use the @command{loadkeys} command. For example,
8235 the following command selects the Dvorak keyboard layout:
8241 See the files under @file{/run/current-system/profile/share/keymaps} for
8242 a list of available keyboard layouts. Run @command{man loadkeys} for
8245 @subsubsection Networking
8247 Run the following command see what your network interfaces are called:
8254 @dots{} or, using the GNU/Linux-specific @command{ip} command:
8260 @c http://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
8261 Wired interfaces have a name starting with @samp{e}; for example, the
8262 interface corresponding to the first on-board Ethernet controller is
8263 called @samp{eno1}. Wireless interfaces have a name starting with
8264 @samp{w}, like @samp{w1p2s0}.
8267 @item Wired connection
8268 To configure a wired network run the following command, substituting
8269 @var{interface} with the name of the wired interface you want to use.
8272 ifconfig @var{interface} up
8275 @item Wireless connection
8278 To configure wireless networking, you can create a configuration file
8279 for the @command{wpa_supplicant} configuration tool (its location is not
8280 important) using one of the available text editors such as
8284 zile wpa_supplicant.conf
8287 As an example, the following stanza can go to this file and will work
8288 for many wireless networks, provided you give the actual SSID and
8289 passphrase for the network you are connecting to:
8293 ssid="@var{my-ssid}"
8295 psk="the network's secret passphrase"
8299 Start the wireless service and run it in the background with the
8300 following command (substitute @var{interface} with the name of the
8301 network interface you want to use):
8304 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
8307 Run @command{man wpa_supplicant} for more information.
8311 At this point, you need to acquire an IP address. On a network where IP
8312 addresses are automatically assigned @i{via} DHCP, you can run:
8315 dhclient -v @var{interface}
8318 Try to ping a server to see if networking is up and running:
8324 Setting up network access is almost always a requirement because the
8325 image does not contain all the software and tools that may be needed.
8327 @cindex installing over SSH
8328 If you want to, you can continue the installation remotely by starting
8332 herd start ssh-daemon
8335 Make sure to either set a password with @command{passwd}, or configure
8336 OpenSSH public key authentication before logging in.
8338 @subsubsection Disk Partitioning
8340 Unless this has already been done, the next step is to partition, and
8341 then format the target partition(s).
8343 The installation image includes several partitioning tools, including
8344 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
8345 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
8346 the partition layout you want:
8352 If your disk uses the GUID Partition Table (GPT) format and you plan to
8353 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
8354 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
8357 @cindex EFI, installation
8358 @cindex UEFI, installation
8359 @cindex ESP, EFI system partition
8360 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
8361 (ESP) is required. This partition should be mounted at @file{/boot/efi} and
8362 must have the @code{esp} flag set. E.g., for @command{parted}:
8365 parted /dev/sda set 1 esp on
8368 Once you are done partitioning the target hard disk drive, you have to
8369 create a file system on the relevant partition(s)@footnote{Currently
8370 GuixSD only supports ext4 and btrfs file systems. In particular, code
8371 that reads file system UUIDs and labels only works for these file system
8372 types.}. For the ESP, if you have one and assuming it is
8373 @file{/dev/sda2}, run:
8376 mkfs.fat -F32 /dev/sda2
8379 Preferably, assign file systems a label so that you can easily and
8380 reliably refer to them in @code{file-system} declarations (@pxref{File
8381 Systems}). This is typically done using the @code{-L} option of
8382 @command{mkfs.ext4} and related commands. So, assuming the target root
8383 partition lives at @file{/dev/sda1}, a file system with the label
8384 @code{my-root} can be created with:
8387 mkfs.ext4 -L my-root /dev/sda1
8390 @cindex encrypted disk
8391 If you are instead planning to encrypt the root partition, you can use
8392 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
8393 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
8394 @code{man cryptsetup}} for more information.) Assuming you want to
8395 store the root partition on @file{/dev/sda1}, the command sequence would
8396 be along these lines:
8399 cryptsetup luksFormat /dev/sda1
8400 cryptsetup open --type luks /dev/sda1 my-partition
8401 mkfs.ext4 -L my-root /dev/mapper/my-partition
8404 Once that is done, mount the target file system under @file{/mnt}
8405 with a command like (again, assuming @code{my-root} is the label of the
8409 mount LABEL=my-root /mnt
8412 Also mount any other file systems you would like to use on the target
8413 system relative to this path. If you have @file{/boot} on a separate
8414 partition for example, mount it at @file{/mnt/boot} now so it is found
8415 by @code{guix system init} afterwards.
8417 Finally, if you plan to use one or more swap partitions (@pxref{Memory
8418 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
8419 sure to initialize them with @command{mkswap}. Assuming you have one
8420 swap partition on @file{/dev/sda2}, you would run:
8427 Alternatively, you may use a swap file. For example, assuming that in
8428 the new system you want to use the file @file{/swapfile} as a swap file,
8429 you would run@footnote{This example will work for many types of file
8430 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
8431 btrfs), the required steps may be different. For details, see the
8432 manual pages for @command{mkswap} and @command{swapon}.}:
8435 # This is 10 GiB of swap space. Adjust "count" to change the size.
8436 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
8437 # For security, make the file readable and writable only by root.
8438 chmod 600 /mnt/swapfile
8439 mkswap /mnt/swapfile
8440 swapon /mnt/swapfile
8443 Note that if you have encrypted the root partition and created a swap
8444 file in its file system as described above, then the encryption also
8445 protects the swap file, just like any other file in that file system.
8447 @node Proceeding with the Installation
8448 @subsection Proceeding with the Installation
8450 With the target partitions ready and the target root mounted on
8451 @file{/mnt}, we're ready to go. First, run:
8454 herd start cow-store /mnt
8457 This makes @file{/gnu/store} copy-on-write, such that packages added to it
8458 during the installation phase are written to the target disk on @file{/mnt}
8459 rather than kept in memory. This is necessary because the first phase of
8460 the @command{guix system init} command (see below) entails downloads or
8461 builds to @file{/gnu/store} which, initially, is an in-memory file system.
8463 Next, you have to edit a file and
8464 provide the declaration of the operating system to be installed. To
8465 that end, the installation system comes with three text editors: GNU nano
8466 (@pxref{Top,,, nano, GNU nano Manual}), GNU Zile (an Emacs clone), and
8467 nvi (a clone of the original BSD @command{vi} editor).
8468 We strongly recommend storing that file on the target root file system, say,
8469 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
8470 configuration file once you have rebooted into the newly-installed system.
8472 @xref{Using the Configuration System}, for an overview of the
8473 configuration file. The example configurations discussed in that
8474 section are available under @file{/etc/configuration} in the
8475 installation image. Thus, to get started with a system configuration
8476 providing a graphical display server (a ``desktop'' system), you can run
8477 something along these lines:
8481 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
8482 # zile /mnt/etc/config.scm
8485 You should pay attention to what your configuration file contains, and
8490 Make sure the @code{bootloader-configuration} form refers to the target
8491 you want to install GRUB on. It should mention @code{grub-bootloader} if
8492 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
8493 for newer UEFI systems. For legacy systems, the @code{target} field
8494 names a device, like @code{/dev/sda}; for UEFI systems it names a path
8495 to a mounted EFI partition, like @code{/boot/efi}, and do make sure the
8496 path is actually mounted.
8499 Be sure that your file system labels match the value of their respective
8500 @code{device} fields in your @code{file-system} configuration, assuming
8501 your @code{file-system} configuration sets the value of @code{title} to
8505 If there are encrypted or RAID partitions, make sure to add a
8506 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
8509 Once you are done preparing the configuration file, the new system must
8510 be initialized (remember that the target root file system is mounted
8514 guix system init /mnt/etc/config.scm /mnt
8518 This copies all the necessary files and installs GRUB on
8519 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
8520 more information, @pxref{Invoking guix system}. This command may trigger
8521 downloads or builds of missing packages, which can take some time.
8523 Once that command has completed---and hopefully succeeded!---you can run
8524 @command{reboot} and boot into the new system. The @code{root} password
8525 in the new system is initially empty; other users' passwords need to be
8526 initialized by running the @command{passwd} command as @code{root},
8527 unless your configuration specifies otherwise
8528 (@pxref{user-account-password, user account passwords}).
8530 @cindex upgrading GuixSD
8531 From then on, you can update GuixSD whenever you want by running
8532 @command{guix pull} as @code{root} (@pxref{Invoking guix pull}), and
8533 then running @command{guix system reconfigure} to build a new system
8534 generation with the latest packages and services (@pxref{Invoking guix
8535 system}). We recommend doing that regularly so that your system
8536 includes the latest security updates (@pxref{Security Updates}).
8538 Join us on @code{#guix} on the Freenode IRC network or on
8539 @file{guix-devel@@gnu.org} to share your experience---good or not so
8542 @node Installing GuixSD in a VM
8543 @subsection Installing GuixSD in a Virtual Machine
8545 @cindex virtual machine, GuixSD installation
8546 @cindex virtual private server (VPS)
8547 @cindex VPS (virtual private server)
8548 If you'd like to install GuixSD in a virtual machine (VM) or on a
8549 virtual private server (VPS) rather than on your beloved machine, this
8552 To boot a @uref{http://qemu.org/,QEMU} VM for installing GuixSD in a
8553 disk image, follow these steps:
8557 First, retrieve and decompress the GuixSD installation image as
8558 described previously (@pxref{USB Stick and DVD Installation}).
8561 Create a disk image that will hold the installed system. To make a
8562 qcow2-formatted disk image, use the @command{qemu-img} command:
8565 qemu-img create -f qcow2 guixsd.img 50G
8568 The resulting file will be much smaller than 50 GB (typically less than
8569 1 MB), but it will grow as the virtualized storage device is filled up.
8572 Boot the USB installation image in an VM:
8575 qemu-system-x86_64 -m 1024 -smp 1 \
8576 -net user -net nic,model=virtio -boot menu=on \
8577 -drive file=guixsd-install-@value{VERSION}.@var{system}.iso \
8578 -drive file=guixsd.img
8581 The ordering of the drives matters.
8583 In the VM console, quickly press the @kbd{F12} key to enter the boot
8584 menu. Then press the @kbd{2} key and the @kbd{RET} key to validate your
8588 You're now root in the VM, proceed with the installation process.
8589 @xref{Preparing for Installation}, and follow the instructions.
8592 Once installation is complete, you can boot the system that's on your
8593 @file{guixsd.img} image. @xref{Running GuixSD in a VM}, for how to do
8596 @node Building the Installation Image
8597 @subsection Building the Installation Image
8599 @cindex installation image
8600 The installation image described above was built using the @command{guix
8601 system} command, specifically:
8604 guix system disk-image gnu/system/install.scm
8607 Have a look at @file{gnu/system/install.scm} in the source tree,
8608 and see also @ref{Invoking guix system} for more information
8609 about the installation image.
8611 @node System Configuration
8612 @section System Configuration
8614 @cindex system configuration
8615 The Guix System Distribution supports a consistent whole-system configuration
8616 mechanism. By that we mean that all aspects of the global system
8617 configuration---such as the available system services, timezone and
8618 locale settings, user accounts---are declared in a single place. Such
8619 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
8621 One of the advantages of putting all the system configuration under the
8622 control of Guix is that it supports transactional system upgrades, and
8623 makes it possible to roll back to a previous system instantiation,
8624 should something go wrong with the new one (@pxref{Features}). Another
8625 advantage is that it makes it easy to replicate the exact same configuration
8626 across different machines, or at different points in time, without
8627 having to resort to additional administration tools layered on top of
8628 the own tools of the system.
8629 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
8631 This section describes this mechanism. First we focus on the system
8632 administrator's viewpoint---explaining how the system is configured and
8633 instantiated. Then we show how this mechanism can be extended, for
8634 instance to support new system services.
8637 * Using the Configuration System:: Customizing your GNU system.
8638 * operating-system Reference:: Detail of operating-system declarations.
8639 * File Systems:: Configuring file system mounts.
8640 * Mapped Devices:: Block device extra processing.
8641 * User Accounts:: Specifying user accounts.
8642 * Locales:: Language and cultural convention settings.
8643 * Services:: Specifying system services.
8644 * Setuid Programs:: Programs running with root privileges.
8645 * X.509 Certificates:: Authenticating HTTPS servers.
8646 * Name Service Switch:: Configuring libc's name service switch.
8647 * Initial RAM Disk:: Linux-Libre bootstrapping.
8648 * Bootloader Configuration:: Configuring the boot loader.
8649 * Invoking guix system:: Instantiating a system configuration.
8650 * Running GuixSD in a VM:: How to run GuixSD in a virtual machine.
8651 * Defining Services:: Adding new service definitions.
8654 @node Using the Configuration System
8655 @subsection Using the Configuration System
8657 The operating system is configured by providing an
8658 @code{operating-system} declaration in a file that can then be passed to
8659 the @command{guix system} command (@pxref{Invoking guix system}). A
8660 simple setup, with the default system services, the default Linux-Libre
8661 kernel, initial RAM disk, and boot loader looks like this:
8663 @findex operating-system
8665 @include os-config-bare-bones.texi
8668 This example should be self-describing. Some of the fields defined
8669 above, such as @code{host-name} and @code{bootloader}, are mandatory.
8670 Others, such as @code{packages} and @code{services}, can be omitted, in
8671 which case they get a default value.
8673 Below we discuss the effect of some of the most important fields
8674 (@pxref{operating-system Reference}, for details about all the available
8675 fields), and how to @dfn{instantiate} the operating system using
8676 @command{guix system}.
8678 @unnumberedsubsubsec Globally-Visible Packages
8680 @vindex %base-packages
8681 The @code{packages} field lists packages that will be globally visible
8682 on the system, for all user accounts---i.e., in every user's @code{PATH}
8683 environment variable---in addition to the per-user profiles
8684 (@pxref{Invoking guix package}). The @var{%base-packages} variable
8685 provides all the tools one would expect for basic user and administrator
8686 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
8687 the GNU Zile lightweight text editor, @command{find}, @command{grep},
8688 etc. The example above adds GNU@tie{}Screen and OpenSSH to those,
8689 taken from the @code{(gnu packages screen)} and @code{(gnu packages ssh)}
8690 modules (@pxref{Package Modules}). The
8691 @code{(list package output)} syntax can be used to add a specific output
8695 (use-modules (gnu packages))
8696 (use-modules (gnu packages dns))
8700 (packages (cons (list bind "utils")
8704 @findex specification->package
8705 Referring to packages by variable name, like @code{bind} above, has
8706 the advantage of being unambiguous; it also allows typos and such to be
8707 diagnosed right away as ``unbound variables''. The downside is that one
8708 needs to know which module defines which package, and to augment the
8709 @code{use-package-modules} line accordingly. To avoid that, one can use
8710 the @code{specification->package} procedure of the @code{(gnu packages)}
8711 module, which returns the best package for a given name or name and
8715 (use-modules (gnu packages))
8719 (packages (append (map specification->package
8720 '("tcpdump" "htop" "gnupg@@2.0"))
8724 @unnumberedsubsubsec System Services
8727 @vindex %base-services
8728 The @code{services} field lists @dfn{system services} to be made
8729 available when the system starts (@pxref{Services}).
8730 The @code{operating-system} declaration above specifies that, in
8731 addition to the basic services, we want the @command{lshd} secure shell
8732 daemon listening on port 2222 (@pxref{Networking Services,
8733 @code{lsh-service}}). Under the hood,
8734 @code{lsh-service} arranges so that @code{lshd} is started with the
8735 right command-line options, possibly with supporting configuration files
8736 generated as needed (@pxref{Defining Services}).
8738 @cindex customization, of services
8739 @findex modify-services
8740 Occasionally, instead of using the base services as is, you will want to
8741 customize them. To do this, use @code{modify-services} (@pxref{Service
8742 Reference, @code{modify-services}}) to modify the list.
8744 For example, suppose you want to modify @code{guix-daemon} and Mingetty
8745 (the console log-in) in the @var{%base-services} list (@pxref{Base
8746 Services, @code{%base-services}}). To do that, you can write the
8747 following in your operating system declaration:
8750 (define %my-services
8751 ;; My very own list of services.
8752 (modify-services %base-services
8753 (guix-service-type config =>
8756 (use-substitutes? #f)
8757 (extra-options '("--gc-keep-derivations"))))
8758 (mingetty-service-type config =>
8759 (mingetty-configuration
8760 (inherit config)))))
8764 (services %my-services))
8767 This changes the configuration---i.e., the service parameters---of the
8768 @code{guix-service-type} instance, and that of all the
8769 @code{mingetty-service-type} instances in the @var{%base-services} list.
8770 Observe how this is accomplished: first, we arrange for the original
8771 configuration to be bound to the identifier @code{config} in the
8772 @var{body}, and then we write the @var{body} so that it evaluates to the
8773 desired configuration. In particular, notice how we use @code{inherit}
8774 to create a new configuration which has the same values as the old
8775 configuration, but with a few modifications.
8777 @cindex encrypted disk
8778 The configuration for a typical ``desktop'' usage, with an encrypted
8779 root partition, the X11 display
8780 server, GNOME and Xfce (users can choose which of these desktop
8781 environments to use at the log-in screen by pressing @kbd{F1}), network
8782 management, power management, and more, would look like this:
8785 @include os-config-desktop.texi
8789 A graphical UEFI system with a choice of lightweight window managers
8790 instead of full-blown desktop environments would look like this:
8793 @include os-config-lightweight-desktop.texi
8796 This example refers to the @file{/boot/efi} file system by its UUID,
8797 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
8798 as returned by the @command{blkid} command.
8800 @xref{Desktop Services}, for the exact list of services provided by
8801 @var{%desktop-services}. @xref{X.509 Certificates}, for background
8802 information about the @code{nss-certs} package that is used here.
8804 Again, @var{%desktop-services} is just a list of service objects. If
8805 you want to remove services from there, you can do so using the
8806 procedures for list filtering (@pxref{SRFI-1 Filtering and
8807 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
8808 following expression returns a list that contains all the services in
8809 @var{%desktop-services} minus the Avahi service:
8812 (remove (lambda (service)
8813 (eq? (service-kind service) avahi-service-type))
8817 @unnumberedsubsubsec Instantiating the System
8819 Assuming the @code{operating-system} declaration
8820 is stored in the @file{my-system-config.scm}
8821 file, the @command{guix system reconfigure my-system-config.scm} command
8822 instantiates that configuration, and makes it the default GRUB boot
8823 entry (@pxref{Invoking guix system}).
8825 The normal way to change the system configuration is by updating this
8826 file and re-running @command{guix system reconfigure}. One should never
8827 have to touch files in @file{/etc} or to run commands that modify the
8828 system state such as @command{useradd} or @command{grub-install}. In
8829 fact, you must avoid that since that would not only void your warranty
8830 but also prevent you from rolling back to previous versions of your
8831 system, should you ever need to.
8833 @cindex roll-back, of the operating system
8834 Speaking of roll-back, each time you run @command{guix system
8835 reconfigure}, a new @dfn{generation} of the system is created---without
8836 modifying or deleting previous generations. Old system generations get
8837 an entry in the bootloader boot menu, allowing you to boot them in case
8838 something went wrong with the latest generation. Reassuring, no? The
8839 @command{guix system list-generations} command lists the system
8840 generations available on disk. It is also possible to roll back the
8841 system via the commands @command{guix system roll-back} and
8842 @command{guix system switch-generation}.
8844 Although the command @command{guix system reconfigure} will not modify
8845 previous generations, must take care when the current generation is not
8846 the latest (e.g., after invoking @command{guix system roll-back}), since
8847 the operation might overwrite a later generation (@pxref{Invoking guix
8850 @unnumberedsubsubsec The Programming Interface
8852 At the Scheme level, the bulk of an @code{operating-system} declaration
8853 is instantiated with the following monadic procedure (@pxref{The Store
8856 @deffn {Monadic Procedure} operating-system-derivation os
8857 Return a derivation that builds @var{os}, an @code{operating-system}
8858 object (@pxref{Derivations}).
8860 The output of the derivation is a single directory that refers to all
8861 the packages, configuration files, and other supporting files needed to
8862 instantiate @var{os}.
8865 This procedure is provided by the @code{(gnu system)} module. Along
8866 with @code{(gnu services)} (@pxref{Services}), this module contains the
8867 guts of GuixSD. Make sure to visit it!
8870 @node operating-system Reference
8871 @subsection @code{operating-system} Reference
8873 This section summarizes all the options available in
8874 @code{operating-system} declarations (@pxref{Using the Configuration
8877 @deftp {Data Type} operating-system
8878 This is the data type representing an operating system configuration.
8879 By that, we mean all the global system configuration, not per-user
8880 configuration (@pxref{Using the Configuration System}).
8883 @item @code{kernel} (default: @var{linux-libre})
8884 The package object of the operating system kernel to use@footnote{Currently
8885 only the Linux-libre kernel is supported. In the future, it will be
8886 possible to use the GNU@tie{}Hurd.}.
8888 @item @code{kernel-arguments} (default: @code{'()})
8889 List of strings or gexps representing additional arguments to pass on
8890 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
8892 @item @code{bootloader}
8893 The system bootloader configuration object. @xref{Bootloader Configuration}.
8895 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
8897 @cindex initial RAM disk
8898 The list of Linux kernel modules that need to be available in the
8899 initial RAM disk. @xref{Initial RAM Disk}.
8901 @item @code{initrd} (default: @code{base-initrd})
8902 A monadic procedure that returns an initial RAM disk for the Linux
8903 kernel. This field is provided to support low-level customization and
8904 should rarely be needed for casual use. @xref{Initial RAM Disk}.
8906 @item @code{firmware} (default: @var{%base-firmware})
8908 List of firmware packages loadable by the operating system kernel.
8910 The default includes firmware needed for Atheros- and Broadcom-based
8911 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
8912 respectively). @xref{Hardware Considerations}, for more info on
8915 @item @code{host-name}
8918 @item @code{hosts-file}
8920 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
8921 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
8922 Reference Manual}). The default is a file with entries for
8923 @code{localhost} and @var{host-name}.
8925 @item @code{mapped-devices} (default: @code{'()})
8926 A list of mapped devices. @xref{Mapped Devices}.
8928 @item @code{file-systems}
8929 A list of file systems. @xref{File Systems}.
8931 @item @code{swap-devices} (default: @code{'()})
8932 @cindex swap devices
8933 A list of strings identifying devices or files to be used for ``swap
8934 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
8935 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
8936 It is possible to specify a swap file in a file system on a mapped
8937 device, provided that the necessary device mapping and file system are
8938 also specified. @xref{Mapped Devices} and @ref{File Systems}.
8940 @item @code{users} (default: @code{%base-user-accounts})
8941 @itemx @code{groups} (default: @var{%base-groups})
8942 List of user accounts and groups. @xref{User Accounts}.
8944 If the @code{users} list lacks a user account with UID@tie{}0, a
8945 ``root'' account with UID@tie{}0 is automatically added.
8947 @item @code{skeletons} (default: @code{(default-skeletons)})
8948 A list target file name/file-like object tuples (@pxref{G-Expressions,
8949 file-like objects}). These are the skeleton files that will be added to
8950 the home directory of newly-created user accounts.
8952 For instance, a valid value may look like this:
8955 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
8956 (".guile" ,(plain-file "guile"
8957 "(use-modules (ice-9 readline))
8958 (activate-readline)")))
8961 @item @code{issue} (default: @var{%default-issue})
8962 A string denoting the contents of the @file{/etc/issue} file, which is
8963 displayed when users log in on a text console.
8965 @item @code{packages} (default: @var{%base-packages})
8966 The set of packages installed in the global profile, which is accessible
8967 at @file{/run/current-system/profile}.
8969 The default set includes core utilities and it is good practice to
8970 install non-core utilities in user profiles (@pxref{Invoking guix
8973 @item @code{timezone}
8974 A timezone identifying string---e.g., @code{"Europe/Paris"}.
8976 You can run the @command{tzselect} command to find out which timezone
8977 string corresponds to your region. Choosing an invalid timezone name
8978 causes @command{guix system} to fail.
8980 @item @code{locale} (default: @code{"en_US.utf8"})
8981 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
8982 Library Reference Manual}). @xref{Locales}, for more information.
8984 @item @code{locale-definitions} (default: @var{%default-locale-definitions})
8985 The list of locale definitions to be compiled and that may be used at
8986 run time. @xref{Locales}.
8988 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
8989 The list of GNU@tie{}libc packages whose locale data and tools are used
8990 to build the locale definitions. @xref{Locales}, for compatibility
8991 considerations that justify this option.
8993 @item @code{name-service-switch} (default: @var{%default-nss})
8994 Configuration of the libc name service switch (NSS)---a
8995 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
8998 @item @code{services} (default: @var{%base-services})
8999 A list of service objects denoting system services. @xref{Services}.
9001 @item @code{pam-services} (default: @code{(base-pam-services)})
9003 @cindex pluggable authentication modules
9004 Linux @dfn{pluggable authentication module} (PAM) services.
9005 @c FIXME: Add xref to PAM services section.
9007 @item @code{setuid-programs} (default: @var{%setuid-programs})
9008 List of string-valued G-expressions denoting setuid programs.
9009 @xref{Setuid Programs}.
9011 @item @code{sudoers-file} (default: @var{%sudoers-specification})
9012 @cindex sudoers file
9013 The contents of the @file{/etc/sudoers} file as a file-like object
9014 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
9016 This file specifies which users can use the @command{sudo} command, what
9017 they are allowed to do, and what privileges they may gain. The default
9018 is that only @code{root} and members of the @code{wheel} group may use
9025 @subsection File Systems
9027 The list of file systems to be mounted is specified in the
9028 @code{file-systems} field of the operating system declaration
9029 (@pxref{Using the Configuration System}). Each file system is declared
9030 using the @code{file-system} form, like this:
9034 (mount-point "/home")
9035 (device "/dev/sda3")
9039 As usual, some of the fields are mandatory---those shown in the example
9040 above---while others can be omitted. These are described below.
9042 @deftp {Data Type} file-system
9043 Objects of this type represent file systems to be mounted. They
9044 contain the following members:
9048 This is a string specifying the type of the file system---e.g.,
9051 @item @code{mount-point}
9052 This designates the place where the file system is to be mounted.
9055 This names the ``source'' of the file system. By default it is the name
9056 of a node under @file{/dev}, but its meaning depends on the @code{title}
9057 field described below.
9059 @item @code{title} (default: @code{'device})
9060 This is a symbol that specifies how the @code{device} field is to be
9063 When it is the symbol @code{device}, then the @code{device} field is
9064 interpreted as a file name; when it is @code{label}, then @code{device}
9065 is interpreted as a file system label name; when it is @code{uuid},
9066 @code{device} is interpreted as a file system unique identifier (UUID).
9068 UUIDs may be converted from their string representation (as shown by the
9069 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
9070 @code{uuid} form expects 16-byte UUIDs as defined in
9071 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
9072 form of UUID used by the ext2 family of file systems and others, but it
9073 is different from ``UUIDs'' found in FAT file systems, for instance.},
9078 (mount-point "/home")
9081 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
9084 The @code{label} and @code{uuid} options offer a way to refer to file
9085 systems without having to hard-code their actual device
9086 name@footnote{Note that, while it is tempting to use
9087 @file{/dev/disk/by-uuid} and similar device names to achieve the same
9088 result, this is not recommended: These special device nodes are created
9089 by the udev daemon and may be unavailable at the time the device is
9092 However, when the source of a file system is a mapped device (@pxref{Mapped
9093 Devices}), its @code{device} field @emph{must} refer to the mapped
9094 device name---e.g., @file{/dev/mapper/root-partition}---and consequently
9095 @code{title} must be set to @code{'device}. This is required so that
9096 the system knows that mounting the file system depends on having the
9097 corresponding device mapping established.
9099 @item @code{flags} (default: @code{'()})
9100 This is a list of symbols denoting mount flags. Recognized flags
9101 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
9102 access to special files), @code{no-suid} (ignore setuid and setgid
9103 bits), and @code{no-exec} (disallow program execution.)
9105 @item @code{options} (default: @code{#f})
9106 This is either @code{#f}, or a string denoting mount options.
9108 @item @code{mount?} (default: @code{#t})
9109 This value indicates whether to automatically mount the file system when
9110 the system is brought up. When set to @code{#f}, the file system gets
9111 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
9112 is not automatically mounted.
9114 @item @code{needed-for-boot?} (default: @code{#f})
9115 This Boolean value indicates whether the file system is needed when
9116 booting. If that is true, then the file system is mounted when the
9117 initial RAM disk (initrd) is loaded. This is always the case, for
9118 instance, for the root file system.
9120 @item @code{check?} (default: @code{#t})
9121 This Boolean indicates whether the file system needs to be checked for
9122 errors before being mounted.
9124 @item @code{create-mount-point?} (default: @code{#f})
9125 When true, the mount point is created if it does not exist yet.
9127 @item @code{dependencies} (default: @code{'()})
9128 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
9129 representing file systems that must be mounted or mapped devices that
9130 must be opened before (and unmounted or closed after) this one.
9132 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
9133 a dependency of @file{/sys/fs/cgroup/cpu} and
9134 @file{/sys/fs/cgroup/memory}.
9136 Another example is a file system that depends on a mapped device, for
9137 example for an encrypted partition (@pxref{Mapped Devices}).
9141 The @code{(gnu system file-systems)} exports the following useful
9144 @defvr {Scheme Variable} %base-file-systems
9145 These are essential file systems that are required on normal systems,
9146 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
9147 below.) Operating system declarations should always contain at least
9151 @defvr {Scheme Variable} %pseudo-terminal-file-system
9152 This is the file system to be mounted as @file{/dev/pts}. It supports
9153 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
9154 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
9155 Manual}). Pseudo-terminals are used by terminal emulators such as
9159 @defvr {Scheme Variable} %shared-memory-file-system
9160 This file system is mounted as @file{/dev/shm} and is used to support
9161 memory sharing across processes (@pxref{Memory-mapped I/O,
9162 @code{shm_open},, libc, The GNU C Library Reference Manual}).
9165 @defvr {Scheme Variable} %immutable-store
9166 This file system performs a read-only ``bind mount'' of
9167 @file{/gnu/store}, making it read-only for all the users including
9168 @code{root}. This prevents against accidental modification by software
9169 running as @code{root} or by system administrators.
9171 The daemon itself is still able to write to the store: it remounts it
9172 read-write in its own ``name space.''
9175 @defvr {Scheme Variable} %binary-format-file-system
9176 The @code{binfmt_misc} file system, which allows handling of arbitrary
9177 executable file types to be delegated to user space. This requires the
9178 @code{binfmt.ko} kernel module to be loaded.
9181 @defvr {Scheme Variable} %fuse-control-file-system
9182 The @code{fusectl} file system, which allows unprivileged users to mount
9183 and unmount user-space FUSE file systems. This requires the
9184 @code{fuse.ko} kernel module to be loaded.
9187 @node Mapped Devices
9188 @subsection Mapped Devices
9190 @cindex device mapping
9191 @cindex mapped devices
9192 The Linux kernel has a notion of @dfn{device mapping}: a block device,
9193 such as a hard disk partition, can be @dfn{mapped} into another device,
9194 usually in @code{/dev/mapper/},
9195 with additional processing over the data that flows through
9196 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
9197 concept of a ``mapped device'' and that of a file system: both boil down
9198 to @emph{translating} input/output operations made on a file to
9199 operations on its backing store. Thus, the Hurd implements mapped
9200 devices, like file systems, using the generic @dfn{translator} mechanism
9201 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
9202 typical example is encryption device mapping: all writes to the mapped
9203 device are encrypted, and all reads are deciphered, transparently.
9204 Guix extends this notion by considering any device or set of devices that
9205 are @dfn{transformed} in some way to create a new device; for instance,
9206 RAID devices are obtained by @dfn{assembling} several other devices, such
9207 as hard disks or partitions, into a new one that behaves as one partition.
9208 Other examples, not yet implemented, are LVM logical volumes.
9210 Mapped devices are declared using the @code{mapped-device} form,
9211 defined as follows; for examples, see below.
9213 @deftp {Data Type} mapped-device
9214 Objects of this type represent device mappings that will be made when
9215 the system boots up.
9219 This is either a string specifying the name of the block device to be mapped,
9220 such as @code{"/dev/sda3"}, or a list of such strings when several devices
9221 need to be assembled for creating a new one.
9224 This string specifies the name of the resulting mapped device. For
9225 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
9226 specifying @code{"my-partition"} leads to the creation of
9227 the @code{"/dev/mapper/my-partition"} device.
9228 For RAID devices of type @code{raid-device-mapping}, the full device name
9229 such as @code{"/dev/md0"} needs to be given.
9232 This must be a @code{mapped-device-kind} object, which specifies how
9233 @var{source} is mapped to @var{target}.
9237 @defvr {Scheme Variable} luks-device-mapping
9238 This defines LUKS block device encryption using the @command{cryptsetup}
9239 command from the package with the same name. It relies on the
9240 @code{dm-crypt} Linux kernel module.
9243 @defvr {Scheme Variable} raid-device-mapping
9244 This defines a RAID device, which is assembled using the @code{mdadm}
9245 command from the package with the same name. It requires a Linux kernel
9246 module for the appropriate RAID level to be loaded, such as @code{raid456}
9247 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
9250 @cindex disk encryption
9252 The following example specifies a mapping from @file{/dev/sda3} to
9253 @file{/dev/mapper/home} using LUKS---the
9254 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
9255 standard mechanism for disk encryption.
9256 The @file{/dev/mapper/home}
9257 device can then be used as the @code{device} of a @code{file-system}
9258 declaration (@pxref{File Systems}).
9262 (source "/dev/sda3")
9264 (type luks-device-mapping))
9267 Alternatively, to become independent of device numbering, one may obtain
9268 the LUKS UUID (@dfn{unique identifier}) of the source device by a
9272 cryptsetup luksUUID /dev/sda3
9275 and use it as follows:
9279 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
9281 (type luks-device-mapping))
9284 @cindex swap encryption
9285 It is also desirable to encrypt swap space, since swap space may contain
9286 sensitive data. One way to accomplish that is to use a swap file in a
9287 file system on a device mapped via LUKS encryption. In this way, the
9288 swap file is encrypted because the entire device is encrypted.
9289 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
9291 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
9292 may be declared as follows:
9296 (source (list "/dev/sda1" "/dev/sdb1"))
9298 (type raid-device-mapping))
9301 The @file{/dev/md0} device can then be used as the @code{device} of a
9302 @code{file-system} declaration (@pxref{File Systems}).
9303 Note that the RAID level need not be given; it is chosen during the
9304 initial creation and formatting of the RAID device and is determined
9305 automatically later.
9309 @subsection User Accounts
9313 @cindex user accounts
9314 User accounts and groups are entirely managed through the
9315 @code{operating-system} declaration. They are specified with the
9316 @code{user-account} and @code{user-group} forms:
9322 (supplementary-groups '("wheel" ;allow use of sudo, etc.
9324 "video" ;video devices such as webcams
9325 "cdrom")) ;the good ol' CD-ROM
9326 (comment "Bob's sister")
9327 (home-directory "/home/alice"))
9330 When booting or upon completion of @command{guix system reconfigure},
9331 the system ensures that only the user accounts and groups specified in
9332 the @code{operating-system} declaration exist, and with the specified
9333 properties. Thus, account or group creations or modifications made by
9334 directly invoking commands such as @command{useradd} are lost upon
9335 reconfiguration or reboot. This ensures that the system remains exactly
9338 @deftp {Data Type} user-account
9339 Objects of this type represent user accounts. The following members may
9344 The name of the user account.
9348 This is the name (a string) or identifier (a number) of the user group
9349 this account belongs to.
9351 @item @code{supplementary-groups} (default: @code{'()})
9352 Optionally, this can be defined as a list of group names that this
9355 @item @code{uid} (default: @code{#f})
9356 This is the user ID for this account (a number), or @code{#f}. In the
9357 latter case, a number is automatically chosen by the system when the
9360 @item @code{comment} (default: @code{""})
9361 A comment about the account, such as the account owner's full name.
9363 @item @code{home-directory}
9364 This is the name of the home directory for the account.
9366 @item @code{create-home-directory?} (default: @code{#t})
9367 Indicates whether the home directory of this account should be created
9368 if it does not exist yet.
9370 @item @code{shell} (default: Bash)
9371 This is a G-expression denoting the file name of a program to be used as
9372 the shell (@pxref{G-Expressions}).
9374 @item @code{system?} (default: @code{#f})
9375 This Boolean value indicates whether the account is a ``system''
9376 account. System accounts are sometimes treated specially; for instance,
9377 graphical login managers do not list them.
9379 @anchor{user-account-password}
9380 @item @code{password} (default: @code{#f})
9381 You would normally leave this field to @code{#f}, initialize user
9382 passwords as @code{root} with the @command{passwd} command, and then let
9383 users change it with @command{passwd}. Passwords set with
9384 @command{passwd} are of course preserved across reboot and
9387 If you @emph{do} want to have a preset password for an account, then
9388 this field must contain the encrypted password, as a string.
9389 @xref{crypt,,, libc, The GNU C Library Reference Manual}, for more information
9390 on password encryption, and @ref{Encryption,,, guile, GNU Guile Reference
9391 Manual}, for information on Guile's @code{crypt} procedure.
9397 User group declarations are even simpler:
9400 (user-group (name "students"))
9403 @deftp {Data Type} user-group
9404 This type is for, well, user groups. There are just a few fields:
9408 The name of the group.
9410 @item @code{id} (default: @code{#f})
9411 The group identifier (a number). If @code{#f}, a new number is
9412 automatically allocated when the group is created.
9414 @item @code{system?} (default: @code{#f})
9415 This Boolean value indicates whether the group is a ``system'' group.
9416 System groups have low numerical IDs.
9418 @item @code{password} (default: @code{#f})
9419 What, user groups can have a password? Well, apparently yes. Unless
9420 @code{#f}, this field specifies the password of the group.
9425 For convenience, a variable lists all the basic user groups one may
9428 @defvr {Scheme Variable} %base-groups
9429 This is the list of basic user groups that users and/or packages expect
9430 to be present on the system. This includes groups such as ``root'',
9431 ``wheel'', and ``users'', as well as groups used to control access to
9432 specific devices such as ``audio'', ``disk'', and ``cdrom''.
9435 @defvr {Scheme Variable} %base-user-accounts
9436 This is the list of basic system accounts that programs may expect to
9437 find on a GNU/Linux system, such as the ``nobody'' account.
9439 Note that the ``root'' account is not included here. It is a
9440 special-case and is automatically added whether or not it is specified.
9447 A @dfn{locale} defines cultural conventions for a particular language
9448 and region of the world (@pxref{Locales,,, libc, The GNU C Library
9449 Reference Manual}). Each locale has a name that typically has the form
9450 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
9451 @code{fr_LU.utf8} designates the locale for the French language, with
9452 cultural conventions from Luxembourg, and using the UTF-8 encoding.
9454 @cindex locale definition
9455 Usually, you will want to specify the default locale for the machine
9456 using the @code{locale} field of the @code{operating-system} declaration
9457 (@pxref{operating-system Reference, @code{locale}}).
9459 The selected locale is automatically added to the @dfn{locale
9460 definitions} known to the system if needed, with its codeset inferred
9461 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
9462 @code{UTF-8} codeset. Additional locale definitions can be specified in
9463 the @code{locale-definitions} slot of @code{operating-system}---this is
9464 useful, for instance, if the codeset could not be inferred from the
9465 locale name. The default set of locale definitions includes some widely
9466 used locales, but not all the available locales, in order to save space.
9468 For instance, to add the North Frisian locale for Germany, the value of
9472 (cons (locale-definition
9473 (name "fy_DE.utf8") (source "fy_DE"))
9474 %default-locale-definitions)
9477 Likewise, to save space, one might want @code{locale-definitions} to
9478 list only the locales that are actually used, as in:
9481 (list (locale-definition
9482 (name "ja_JP.eucjp") (source "ja_JP")
9483 (charset "EUC-JP")))
9487 The compiled locale definitions are available at
9488 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
9489 version, which is the default location where the GNU@tie{}libc provided
9490 by Guix looks for locale data. This can be overridden using the
9491 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
9492 @code{LOCPATH} and locale packages}).
9494 The @code{locale-definition} form is provided by the @code{(gnu system
9495 locale)} module. Details are given below.
9497 @deftp {Data Type} locale-definition
9498 This is the data type of a locale definition.
9503 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
9504 Reference Manual}, for more information on locale names.
9507 The name of the source for that locale. This is typically the
9508 @code{@var{language}_@var{territory}} part of the locale name.
9510 @item @code{charset} (default: @code{"UTF-8"})
9511 The ``character set'' or ``code set'' for that locale,
9512 @uref{http://www.iana.org/assignments/character-sets, as defined by
9518 @defvr {Scheme Variable} %default-locale-definitions
9519 A list of commonly used UTF-8 locales, used as the default
9520 value of the @code{locale-definitions} field of @code{operating-system}
9524 @cindex normalized codeset in locale names
9525 These locale definitions use the @dfn{normalized codeset} for the part
9526 that follows the dot in the name (@pxref{Using gettextized software,
9527 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
9528 instance it has @code{uk_UA.utf8} but @emph{not}, say,
9532 @subsubsection Locale Data Compatibility Considerations
9534 @cindex incompatibility, of locale data
9535 @code{operating-system} declarations provide a @code{locale-libcs} field
9536 to specify the GNU@tie{}libc packages that are used to compile locale
9537 declarations (@pxref{operating-system Reference}). ``Why would I
9538 care?'', you may ask. Well, it turns out that the binary format of
9539 locale data is occasionally incompatible from one libc version to
9542 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
9543 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
9544 For instance, a program linked against libc version 2.21 is unable to
9545 read locale data produced with libc 2.22; worse, that program
9546 @emph{aborts} instead of simply ignoring the incompatible locale
9547 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
9548 the incompatible locale data, which is already an improvement.}.
9549 Similarly, a program linked against libc 2.22 can read most, but not
9550 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
9551 data is incompatible); thus calls to @code{setlocale} may fail, but
9552 programs will not abort.
9554 The ``problem'' in GuixSD is that users have a lot of freedom: They can
9555 choose whether and when to upgrade software in their profiles, and might
9556 be using a libc version different from the one the system administrator
9557 used to build the system-wide locale data.
9559 Fortunately, unprivileged users can also install their own locale data
9560 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
9561 @code{GUIX_LOCPATH} and locale packages}).
9563 Still, it is best if the system-wide locale data at
9564 @file{/run/current-system/locale} is built for all the libc versions
9565 actually in use on the system, so that all the programs can access
9566 it---this is especially crucial on a multi-user system. To do that, the
9567 administrator can specify several libc packages in the
9568 @code{locale-libcs} field of @code{operating-system}:
9571 (use-package-modules base)
9575 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
9578 This example would lead to a system containing locale definitions for
9579 both libc 2.21 and the current version of libc in
9580 @file{/run/current-system/locale}.
9584 @subsection Services
9586 @cindex system services
9587 An important part of preparing an @code{operating-system} declaration is
9588 listing @dfn{system services} and their configuration (@pxref{Using the
9589 Configuration System}). System services are typically daemons launched
9590 when the system boots, or other actions needed at that time---e.g.,
9591 configuring network access.
9593 GuixSD has a broad definition of ``service'' (@pxref{Service
9594 Composition}), but many services are managed by the GNU@tie{}Shepherd
9595 (@pxref{Shepherd Services}). On a running system, the @command{herd}
9596 command allows you to list the available services, show their status,
9597 start and stop them, or do other specific operations (@pxref{Jump
9598 Start,,, shepherd, The GNU Shepherd Manual}). For example:
9604 The above command, run as @code{root}, lists the currently defined
9605 services. The @command{herd doc} command shows a synopsis of the given
9610 Run libc's name service cache daemon (nscd).
9613 The @command{start}, @command{stop}, and @command{restart} sub-commands
9614 have the effect you would expect. For instance, the commands below stop
9615 the nscd service and restart the Xorg display server:
9619 Service nscd has been stopped.
9620 # herd restart xorg-server
9621 Service xorg-server has been stopped.
9622 Service xorg-server has been started.
9625 The following sections document the available services, starting with
9626 the core services, that may be used in an @code{operating-system}
9630 * Base Services:: Essential system services.
9631 * Scheduled Job Execution:: The mcron service.
9632 * Log Rotation:: The rottlog service.
9633 * Networking Services:: Network setup, SSH daemon, etc.
9634 * X Window:: Graphical display.
9635 * Printing Services:: Local and remote printer support.
9636 * Desktop Services:: D-Bus and desktop services.
9637 * Database Services:: SQL databases, key-value stores, etc.
9638 * Mail Services:: IMAP, POP3, SMTP, and all that.
9639 * Messaging Services:: Messaging services.
9640 * Telephony Services:: Telephony services.
9641 * Monitoring Services:: Monitoring services.
9642 * Kerberos Services:: Kerberos services.
9643 * Web Services:: Web servers.
9644 * Certificate Services:: TLS certificates via Let's Encrypt.
9645 * DNS Services:: DNS daemons.
9646 * VPN Services:: VPN daemons.
9647 * Network File System:: NFS related services.
9648 * Continuous Integration:: The Cuirass service.
9649 * Power management Services:: The TLP tool.
9650 * Audio Services:: The MPD.
9651 * Virtualization Services:: Virtualization services.
9652 * Version Control Services:: Providing remote access to Git repositories.
9653 * Game Services:: Game servers.
9654 * Miscellaneous Services:: Other services.
9658 @subsubsection Base Services
9660 The @code{(gnu services base)} module provides definitions for the basic
9661 services that one expects from the system. The services exported by
9662 this module are listed below.
9664 @defvr {Scheme Variable} %base-services
9665 This variable contains a list of basic services (@pxref{Service Types
9666 and Services}, for more information on service objects) one would
9667 expect from the system: a login service (mingetty) on each tty, syslogd,
9668 the libc name service cache daemon (nscd), the udev device manager, and
9671 This is the default value of the @code{services} field of
9672 @code{operating-system} declarations. Usually, when customizing a
9673 system, you will want to append services to @var{%base-services}, like
9677 (cons* (avahi-service) (lsh-service) %base-services)
9681 @defvr {Scheme Variable} special-files-service-type
9682 This is the service that sets up ``special files'' such as
9683 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
9685 The value associated with @code{special-files-service-type} services
9686 must be a list of tuples where the first element is the ``special file''
9687 and the second element is its target. By default it is:
9689 @cindex @file{/bin/sh}
9690 @cindex @file{sh}, in @file{/bin}
9692 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
9695 @cindex @file{/usr/bin/env}
9696 @cindex @file{env}, in @file{/usr/bin}
9697 If you want to add, say, @code{/usr/bin/env} to your system, you can
9701 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
9702 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
9705 Since this is part of @code{%base-services}, you can use
9706 @code{modify-services} to customize the set of special files
9707 (@pxref{Service Reference, @code{modify-services}}). But the simple way
9708 to add a special file is @i{via} the @code{extra-special-file} procedure
9712 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
9713 Use @var{target} as the ``special file'' @var{file}.
9715 For example, adding the following lines to the @code{services} field of
9716 your operating system declaration leads to a @file{/usr/bin/env}
9720 (extra-special-file "/usr/bin/env"
9721 (file-append coreutils "/bin/env"))
9725 @deffn {Scheme Procedure} host-name-service @var{name}
9726 Return a service that sets the host name to @var{name}.
9729 @deffn {Scheme Procedure} login-service @var{config}
9730 Return a service to run login according to @var{config}, a
9731 @code{<login-configuration>} object, which specifies the message of the day,
9735 @deftp {Data Type} login-configuration
9736 This is the data type representing the configuration of login.
9741 @cindex message of the day
9742 A file-like object containing the ``message of the day''.
9744 @item @code{allow-empty-passwords?} (default: @code{#t})
9745 Allow empty passwords by default so that first-time users can log in when
9746 the 'root' account has just been created.
9751 @deffn {Scheme Procedure} mingetty-service @var{config}
9752 Return a service to run mingetty according to @var{config}, a
9753 @code{<mingetty-configuration>} object, which specifies the tty to run, among
9757 @deftp {Data Type} mingetty-configuration
9758 This is the data type representing the configuration of Mingetty, which
9759 provides the default implementation of virtual console log-in.
9764 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
9766 @item @code{auto-login} (default: @code{#f})
9767 When true, this field must be a string denoting the user name under
9768 which the system automatically logs in. When it is @code{#f}, a
9769 user name and password must be entered to log in.
9771 @item @code{login-program} (default: @code{#f})
9772 This must be either @code{#f}, in which case the default log-in program
9773 is used (@command{login} from the Shadow tool suite), or a gexp denoting
9774 the name of the log-in program.
9776 @item @code{login-pause?} (default: @code{#f})
9777 When set to @code{#t} in conjunction with @var{auto-login}, the user
9778 will have to press a key before the log-in shell is launched.
9780 @item @code{mingetty} (default: @var{mingetty})
9781 The Mingetty package to use.
9786 @deffn {Scheme Procedure} agetty-service @var{config}
9787 Return a service to run agetty according to @var{config}, an
9788 @code{<agetty-configuration>} object, which specifies the tty to run,
9792 @deftp {Data Type} agetty-configuration
9793 This is the data type representing the configuration of agetty, which
9794 implements virtual and serial console log-in. See the @code{agetty(8)}
9795 man page for more information.
9800 The name of the console this agetty runs on, as a string---e.g.,
9801 @code{"ttyS0"}. This argument is optional, it will default to
9802 a reasonable default serial port used by the kernel Linux.
9804 For this, if there is a value for an option @code{agetty.tty} in the kernel
9805 command line, agetty will extract the device name of the serial port
9806 from it and use that.
9808 If not and if there is a value for an option @code{console} with a tty in
9809 the Linux command line, agetty will extract the device name of the
9810 serial port from it and use that.
9812 In both cases, agetty will leave the other serial device settings
9813 (baud rate etc.) alone---in the hope that Linux pinned them to the
9816 @item @code{baud-rate} (default: @code{#f})
9817 A string containing a comma-separated list of one or more baud rates, in
9820 @item @code{term} (default: @code{#f})
9821 A string containing the value used for the @code{TERM} environment
9824 @item @code{eight-bits?} (default: @code{#f})
9825 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
9828 @item @code{auto-login} (default: @code{#f})
9829 When passed a login name, as a string, the specified user will be logged
9830 in automatically without prompting for their login name or password.
9832 @item @code{no-reset?} (default: @code{#f})
9833 When @code{#t}, don't reset terminal cflags (control modes).
9835 @item @code{host} (default: @code{#f})
9836 This accepts a string containing the "login_host", which will be written
9837 into the @file{/var/run/utmpx} file.
9839 @item @code{remote?} (default: @code{#f})
9840 When set to @code{#t} in conjunction with @var{host}, this will add an
9841 @code{-r} fakehost option to the command line of the login program
9842 specified in @var{login-program}.
9844 @item @code{flow-control?} (default: @code{#f})
9845 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
9847 @item @code{no-issue?} (default: @code{#f})
9848 When set to @code{#t}, the contents of the @file{/etc/issue} file will
9849 not be displayed before presenting the login prompt.
9851 @item @code{init-string} (default: @code{#f})
9852 This accepts a string that will be sent to the tty or modem before
9853 sending anything else. It can be used to initialize a modem.
9855 @item @code{no-clear?} (default: @code{#f})
9856 When set to @code{#t}, agetty will not clear the screen before showing
9859 @item @code{login-program} (default: (file-append shadow "/bin/login"))
9860 This must be either a gexp denoting the name of a log-in program, or
9861 unset, in which case the default value is the @command{login} from the
9864 @item @code{local-line} (default: @code{#f})
9865 Control the CLOCAL line flag. This accepts one of three symbols as
9866 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
9867 the default value chosen by agetty is @code{'auto}.
9869 @item @code{extract-baud?} (default: @code{#f})
9870 When set to @code{#t}, instruct agetty to try to extract the baud rate
9871 from the status messages produced by certain types of modems.
9873 @item @code{skip-login?} (default: @code{#f})
9874 When set to @code{#t}, do not prompt the user for a login name. This
9875 can be used with @var{login-program} field to use non-standard login
9878 @item @code{no-newline?} (default: @code{#f})
9879 When set to @code{#t}, do not print a newline before printing the
9880 @file{/etc/issue} file.
9882 @c Is this dangerous only when used with login-program, or always?
9883 @item @code{login-options} (default: @code{#f})
9884 This option accepts a string containing options that are passed to the
9885 login program. When used with the @var{login-program}, be aware that a
9886 malicious user could try to enter a login name containing embedded
9887 options that could be parsed by the login program.
9889 @item @code{login-pause} (default: @code{#f})
9890 When set to @code{#t}, wait for any key before showing the login prompt.
9891 This can be used in conjunction with @var{auto-login} to save memory by
9892 lazily spawning shells.
9894 @item @code{chroot} (default: @code{#f})
9895 Change root to the specified directory. This option accepts a directory
9898 @item @code{hangup?} (default: @code{#f})
9899 Use the Linux system call @code{vhangup} to do a virtual hangup of the
9902 @item @code{keep-baud?} (default: @code{#f})
9903 When set to @code{#t}, try to keep the existing baud rate. The baud
9904 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
9907 @item @code{timeout} (default: @code{#f})
9908 When set to an integer value, terminate if no user name could be read
9909 within @var{timeout} seconds.
9911 @item @code{detect-case?} (default: @code{#f})
9912 When set to @code{#t}, turn on support for detecting an uppercase-only
9913 terminal. This setting will detect a login name containing only
9914 uppercase letters as indicating an uppercase-only terminal and turn on
9915 some upper-to-lower case conversions. Note that this will not support
9918 @item @code{wait-cr?} (default: @code{#f})
9919 When set to @code{#t}, wait for the user or modem to send a
9920 carriage-return or linefeed character before displaying
9921 @file{/etc/issue} or login prompt. This is typically used with the
9922 @var{init-string} option.
9924 @item @code{no-hints?} (default: @code{#f})
9925 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
9928 @item @code{no-hostname?} (default: @code{#f})
9929 By default, the hostname is printed. When this option is set to
9930 @code{#t}, no hostname will be shown at all.
9932 @item @code{long-hostname?} (default: @code{#f})
9933 By default, the hostname is only printed until the first dot. When this
9934 option is set to @code{#t}, the fully qualified hostname by
9935 @code{gethostname} or @code{getaddrinfo} is shown.
9937 @item @code{erase-characters} (default: @code{#f})
9938 This option accepts a string of additional characters that should be
9939 interpreted as backspace when the user types their login name.
9941 @item @code{kill-characters} (default: @code{#f})
9942 This option accepts a string that should be interpreted to mean "ignore
9943 all previous characters" (also called a "kill" character) when the types
9946 @item @code{chdir} (default: @code{#f})
9947 This option accepts, as a string, a directory path that will be changed
9950 @item @code{delay} (default: @code{#f})
9951 This options accepts, as an integer, the number of seconds to sleep
9952 before opening the tty and displaying the login prompt.
9954 @item @code{nice} (default: @code{#f})
9955 This option accepts, as an integer, the nice value with which to run the
9956 @command{login} program.
9958 @item @code{extra-options} (default: @code{'()})
9959 This option provides an "escape hatch" for the user to provide arbitrary
9960 command-line arguments to @command{agetty} as a list of strings.
9965 @deffn {Scheme Procedure} kmscon-service-type @var{config}
9966 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
9967 according to @var{config}, a @code{<kmscon-configuration>} object, which
9968 specifies the tty to run, among other things.
9971 @deftp {Data Type} kmscon-configuration
9972 This is the data type representing the configuration of Kmscon, which
9973 implements virtual console log-in.
9977 @item @code{virtual-terminal}
9978 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
9980 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
9981 A gexp denoting the name of the log-in program. The default log-in program is
9982 @command{login} from the Shadow tool suite.
9984 @item @code{login-arguments} (default: @code{'("-p")})
9985 A list of arguments to pass to @command{login}.
9987 @item @code{hardware-acceleration?} (default: #f)
9988 Whether to use hardware acceleration.
9990 @item @code{kmscon} (default: @var{kmscon})
9991 The Kmscon package to use.
9996 @cindex name service cache daemon
9998 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
9999 [#:name-services '()]
10000 Return a service that runs the libc name service cache daemon (nscd) with the
10001 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
10002 Service Switch}, for an example.
10005 @defvr {Scheme Variable} %nscd-default-configuration
10006 This is the default @code{<nscd-configuration>} value (see below) used
10007 by @code{nscd-service}. It uses the caches defined by
10008 @var{%nscd-default-caches}; see below.
10011 @deftp {Data Type} nscd-configuration
10012 This is the data type representing the name service cache daemon (nscd)
10017 @item @code{name-services} (default: @code{'()})
10018 List of packages denoting @dfn{name services} that must be visible to
10019 the nscd---e.g., @code{(list @var{nss-mdns})}.
10021 @item @code{glibc} (default: @var{glibc})
10022 Package object denoting the GNU C Library providing the @command{nscd}
10025 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
10026 Name of the nscd log file. This is where debugging output goes when
10027 @code{debug-level} is strictly positive.
10029 @item @code{debug-level} (default: @code{0})
10030 Integer denoting the debugging levels. Higher numbers mean that more
10031 debugging output is logged.
10033 @item @code{caches} (default: @var{%nscd-default-caches})
10034 List of @code{<nscd-cache>} objects denoting things to be cached; see
10040 @deftp {Data Type} nscd-cache
10041 Data type representing a cache database of nscd and its parameters.
10045 @item @code{database}
10046 This is a symbol representing the name of the database to be cached.
10047 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
10048 @code{services}, which designate the corresponding NSS database
10049 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
10051 @item @code{positive-time-to-live}
10052 @itemx @code{negative-time-to-live} (default: @code{20})
10053 A number representing the number of seconds during which a positive or
10054 negative lookup result remains in cache.
10056 @item @code{check-files?} (default: @code{#t})
10057 Whether to check for updates of the files corresponding to
10060 For instance, when @var{database} is @code{hosts}, setting this flag
10061 instructs nscd to check for updates in @file{/etc/hosts} and to take
10064 @item @code{persistent?} (default: @code{#t})
10065 Whether the cache should be stored persistently on disk.
10067 @item @code{shared?} (default: @code{#t})
10068 Whether the cache should be shared among users.
10070 @item @code{max-database-size} (default: 32@tie{}MiB)
10071 Maximum size in bytes of the database cache.
10073 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
10074 @c settings, so leave them out.
10079 @defvr {Scheme Variable} %nscd-default-caches
10080 List of @code{<nscd-cache>} objects used by default by
10081 @code{nscd-configuration} (see above).
10083 It enables persistent and aggressive caching of service and host name
10084 lookups. The latter provides better host name lookup performance,
10085 resilience in the face of unreliable name servers, and also better
10086 privacy---often the result of host name lookups is in local cache, so
10087 external name servers do not even need to be queried.
10090 @anchor{syslog-configuration-type}
10093 @deftp {Data Type} syslog-configuration
10094 This data type represents the configuration of the syslog daemon.
10097 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
10098 The syslog daemon to use.
10100 @item @code{config-file} (default: @code{%default-syslog.conf})
10101 The syslog configuration file to use.
10106 @anchor{syslog-service}
10108 @deffn {Scheme Procedure} syslog-service @var{config}
10109 Return a service that runs a syslog daemon according to @var{config}.
10111 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
10112 information on the configuration file syntax.
10115 @anchor{guix-configuration-type}
10116 @deftp {Data Type} guix-configuration
10117 This data type represents the configuration of the Guix build daemon.
10118 @xref{Invoking guix-daemon}, for more information.
10121 @item @code{guix} (default: @var{guix})
10122 The Guix package to use.
10124 @item @code{build-group} (default: @code{"guixbuild"})
10125 Name of the group for build user accounts.
10127 @item @code{build-accounts} (default: @code{10})
10128 Number of build user accounts to create.
10130 @item @code{authorize-key?} (default: @code{#t})
10131 @cindex substitutes, authorization thereof
10132 Whether to authorize the substitute keys listed in
10133 @code{authorized-keys}---by default that of @code{hydra.gnu.org}
10134 (@pxref{Substitutes}).
10136 @vindex %default-authorized-guix-keys
10137 @item @code{authorized-keys} (default: @var{%default-authorized-guix-keys})
10138 The list of authorized key files for archive imports, as a list of
10139 string-valued gexps (@pxref{Invoking guix archive}). By default, it
10140 contains that of @code{hydra.gnu.org} (@pxref{Substitutes}).
10142 @item @code{use-substitutes?} (default: @code{#t})
10143 Whether to use substitutes.
10145 @item @code{substitute-urls} (default: @var{%default-substitute-urls})
10146 The list of URLs where to look for substitutes by default.
10148 @item @code{max-silent-time} (default: @code{0})
10149 @itemx @code{timeout} (default: @code{0})
10150 The number of seconds of silence and the number of seconds of activity,
10151 respectively, after which a build process times out. A value of zero
10152 disables the timeout.
10154 @item @code{log-compression} (default: @code{'bzip2})
10155 The type of compression used for build logs---one of @code{gzip},
10156 @code{bzip2}, or @code{none}.
10158 @item @code{extra-options} (default: @code{'()})
10159 List of extra command-line options for @command{guix-daemon}.
10161 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
10162 File where @command{guix-daemon}'s standard output and standard error
10165 @item @code{http-proxy} (default: @code{#f})
10166 The HTTP proxy used for downloading fixed-output derivations and
10169 @item @code{tmpdir} (default: @code{#f})
10170 A directory path where the @command{guix-daemon} will perform builds.
10175 @deffn {Scheme Procedure} guix-service @var{config}
10176 Return a service that runs the Guix build daemon according to
10180 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
10181 Run @var{udev}, which populates the @file{/dev} directory dynamically.
10182 udev rules can be provided as a list of files through the @var{rules}
10183 variable. The procedures @var{udev-rule} and @var{file->udev-rule} from
10184 @code{(gnu services base)} simplify the creation of such rule files.
10186 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
10187 Return a udev-rule file named @var{file-name} containing the rules
10188 defined by the @var{contents} literal.
10190 In the following example, a rule for a USB device is defined to be
10191 stored in the file @file{90-usb-thing.rules}. The rule runs a script
10192 upon detecting a USB device with a given product identifier.
10195 (define %example-udev-rule
10197 "90-usb-thing.rules"
10198 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
10199 "ATTR@{product@}==\"Example\", "
10200 "RUN+=\"/path/to/script\"")))
10204 Here we show how the default @var{udev-service} can be extended with it.
10210 (modify-services %desktop-services
10211 (udev-service-type config =>
10212 (udev-configuration (inherit config)
10213 (rules (append (udev-configuration-rules config)
10214 (list %example-udev-rule))))))))
10217 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
10218 Return a udev file named @var{file-name} containing the rules defined
10219 within @var{file}, a file-like object.
10221 The following example showcases how we can use an existing rule file.
10224 (use-modules (guix download) ;for url-fetch
10225 (guix packages) ;for origin
10228 (define %android-udev-rules
10230 "51-android-udev.rules"
10231 (let ((version "20170910"))
10234 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
10235 "android-udev-rules/" version "/51-android.rules"))
10237 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
10241 Additionally, Guix package definitions can be included in @var{rules} in
10242 order to extend the udev rules with the definitions found under their
10243 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
10244 @var{file->udev-rule} example, we could have used the
10245 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
10246 packages android)} module.
10248 The following example shows how to use the @var{android-udev-rules}
10249 package so that the Android tool @command{adb} can detect devices
10250 without root privileges. It also details how to create the
10251 @code{adbusers} group, which is required for the proper functioning of
10252 the rules defined within the @var{android-udev-rules} package. To
10253 create such a group, we must define it both as part of the
10254 @var{supplementary-groups} of our @var{user-account} declaration, as
10255 well as in the @var{groups} field of the @var{operating-system} record.
10258 (use-modules (gnu packages android) ;for android-udev-rules
10259 (gnu system shadow) ;for user-group
10264 (users (cons (user-acount
10266 (supplementary-groups
10267 '("adbusers" ;for adb
10268 "wheel" "netdev" "audio" "video"))
10271 (groups (cons (user-group (system? #t) (name "adbusers"))
10277 (modify-services %desktop-services
10278 (udev-service-type config =>
10279 (udev-configuration (inherit config)
10280 (rules (cons* android-udev-rules
10281 (udev-configuration-rules config))))))))
10285 @defvr {Scheme Variable} urandom-seed-service-type
10286 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
10287 when rebooting. It also tries to seed @file{/dev/urandom} from
10288 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
10292 @defvr {Scheme Variable} %random-seed-file
10293 This is the name of the file where some random bytes are saved by
10294 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
10295 It defaults to @file{/var/lib/random-seed}.
10300 @deffn {Scheme Procedure} console-keymap-service @var{files} ...
10301 @cindex keyboard layout
10302 Return a service to load console keymaps from @var{files} using
10303 @command{loadkeys} command. Most likely, you want to load some default
10304 keymap, which can be done like this:
10307 (console-keymap-service "dvorak")
10310 Or, for example, for a Swedish keyboard, you may need to combine
10311 the following keymaps:
10313 (console-keymap-service "se-lat6" "se-fi-lat6")
10316 Also you can specify a full file name (or file names) of your keymap(s).
10317 See @code{man loadkeys} for details.
10323 @deffn {Scheme Procedure} gpm-service [#:gpm @var{gpm}] @
10325 Run @var{gpm}, the general-purpose mouse daemon, with the given
10326 command-line @var{options}. GPM allows users to use the mouse in the console,
10327 notably to select, copy, and paste text. The default value of @var{options}
10328 uses the @code{ps2} protocol, which works for both USB and PS/2 mice.
10330 This service is not part of @var{%base-services}.
10333 @anchor{guix-publish-service-type}
10334 @deffn {Scheme Variable} guix-publish-service-type
10335 This is the service type for @command{guix publish} (@pxref{Invoking
10336 guix publish}). Its value must be a @code{guix-configuration}
10337 object, as described below.
10339 This assumes that @file{/etc/guix} already contains a signing key pair as
10340 created by @command{guix archive --generate-key} (@pxref{Invoking guix
10341 archive}). If that is not the case, the service will fail to start.
10344 @deftp {Data Type} guix-publish-configuration
10345 Data type representing the configuration of the @code{guix publish}
10349 @item @code{guix} (default: @code{guix})
10350 The Guix package to use.
10352 @item @code{port} (default: @code{80})
10353 The TCP port to listen for connections.
10355 @item @code{host} (default: @code{"localhost"})
10356 The host (and thus, network interface) to listen to. Use
10357 @code{"0.0.0.0"} to listen on all the network interfaces.
10359 @item @code{compression-level} (default: @code{3})
10360 The gzip compression level at which substitutes are compressed. Use
10361 @code{0} to disable compression altogether, and @code{9} to get the best
10362 compression ratio at the expense of increased CPU usage.
10364 @item @code{nar-path} (default: @code{"nar"})
10365 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
10366 publish, @code{--nar-path}}, for details.
10368 @item @code{cache} (default: @code{#f})
10369 When it is @code{#f}, disable caching and instead generate archives on
10370 demand. Otherwise, this should be the name of a directory---e.g.,
10371 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
10372 archives and meta-data ready to be sent. @xref{Invoking guix publish,
10373 @option{--cache}}, for more information on the tradeoffs involved.
10375 @item @code{workers} (default: @code{#f})
10376 When it is an integer, this is the number of worker threads used for
10377 caching; when @code{#f}, the number of processors is used.
10378 @xref{Invoking guix publish, @option{--workers}}, for more information.
10380 @item @code{ttl} (default: @code{#f})
10381 When it is an integer, this denotes the @dfn{time-to-live} in seconds
10382 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
10383 for more information.
10387 @anchor{rngd-service}
10388 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
10389 [#:device "/dev/hwrng"]
10390 Return a service that runs the @command{rngd} program from @var{rng-tools}
10391 to add @var{device} to the kernel's entropy pool. The service will fail if
10392 @var{device} does not exist.
10395 @anchor{pam-limits-service}
10396 @cindex session limits
10399 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
10401 Return a service that installs a configuration file for the
10402 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
10403 @code{pam_limits} module}. The procedure optionally takes a list of
10404 @code{pam-limits-entry} values, which can be used to specify
10405 @code{ulimit} limits and nice priority limits to user sessions.
10407 The following limits definition sets two hard and soft limits for all
10408 login sessions of users in the @code{realtime} group:
10411 (pam-limits-service
10413 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
10414 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
10417 The first entry increases the maximum realtime priority for
10418 non-privileged processes; the second entry lifts any restriction of the
10419 maximum address space that can be locked in memory. These settings are
10420 commonly used for real-time audio systems.
10423 @node Scheduled Job Execution
10424 @subsubsection Scheduled Job Execution
10428 @cindex scheduling jobs
10429 The @code{(gnu services mcron)} module provides an interface to
10430 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
10431 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
10432 Unix @command{cron} daemon; the main difference is that it is
10433 implemented in Guile Scheme, which provides a lot of flexibility when
10434 specifying the scheduling of jobs and their actions.
10436 The example below defines an operating system that runs the
10437 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
10438 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
10439 well as the @command{mkid} command on behalf of an unprivileged user
10440 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
10441 gexps to introduce job definitions that are passed to mcron
10442 (@pxref{G-Expressions}).
10445 (use-modules (guix) (gnu) (gnu services mcron))
10446 (use-package-modules base idutils)
10448 (define updatedb-job
10449 ;; Run 'updatedb' at 3AM every day. Here we write the
10450 ;; job's action as a Scheme procedure.
10451 #~(job '(next-hour '(3))
10453 (execl (string-append #$findutils "/bin/updatedb")
10455 "--prunepaths=/tmp /var/tmp /gnu/store"))))
10457 (define garbage-collector-job
10458 ;; Collect garbage 5 minutes after midnight every day.
10459 ;; The job's action is a shell command.
10460 #~(job "5 0 * * *" ;Vixie cron syntax
10463 (define idutils-job
10464 ;; Update the index database as user "charlie" at 12:15PM
10465 ;; and 19:15PM. This runs from the user's home directory.
10466 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
10467 (string-append #$idutils "/bin/mkid src")
10472 (services (cons (mcron-service (list garbage-collector-job
10478 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
10479 for more information on mcron job specifications. Below is the
10480 reference of the mcron service.
10482 @deffn {Scheme Procedure} mcron-service @var{jobs} [#:mcron @var{mcron2}]
10483 Return an mcron service running @var{mcron} that schedules @var{jobs}, a
10484 list of gexps denoting mcron job specifications.
10486 This is a shorthand for:
10488 (service mcron-service-type
10489 (mcron-configuration (mcron mcron) (jobs jobs)))
10493 @defvr {Scheme Variable} mcron-service-type
10494 This is the type of the @code{mcron} service, whose value is an
10495 @code{mcron-configuration} object.
10497 This service type can be the target of a service extension that provides
10498 it additional job specifications (@pxref{Service Composition}). In
10499 other words, it is possible to define services that provide additional
10503 @deftp {Data Type} mcron-configuration
10504 Data type representing the configuration of mcron.
10507 @item @code{mcron} (default: @var{mcron2})
10508 The mcron package to use.
10511 This is a list of gexps (@pxref{G-Expressions}), where each gexp
10512 corresponds to an mcron job specification (@pxref{Syntax, mcron job
10513 specifications,, mcron, GNU@tie{}mcron}).
10519 @subsubsection Log Rotation
10522 @cindex log rotation
10524 Log files such as those found in @file{/var/log} tend to grow endlessly,
10525 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
10526 their contents in separate files, possibly compressed. The @code{(gnu
10527 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
10528 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
10530 The example below defines an operating system that provides log rotation
10531 with the default settings, for commonly encountered log files.
10534 (use-modules (guix) (gnu))
10535 (use-service-modules admin mcron)
10536 (use-package-modules base idutils)
10540 (services (cons (service rottlog-service-type)
10544 @defvr {Scheme Variable} rottlog-service-type
10545 This is the type of the Rottlog service, whose value is a
10546 @code{rottlog-configuration} object.
10548 Other services can extend this one with new @code{log-rotation} objects
10549 (see below), thereby augmenting the set of files to be rotated.
10551 This service type can define mcron jobs (@pxref{Scheduled Job
10552 Execution}) to run the rottlog service.
10555 @deftp {Data Type} rottlog-configuration
10556 Data type representing the configuration of rottlog.
10559 @item @code{rottlog} (default: @code{rottlog})
10560 The Rottlog package to use.
10562 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
10563 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
10564 rottlog, GNU Rot[t]log Manual}).
10566 @item @code{rotations} (default: @code{%default-rotations})
10567 A list of @code{log-rotation} objects as defined below.
10570 This is a list of gexps where each gexp corresponds to an mcron job
10571 specification (@pxref{Scheduled Job Execution}).
10575 @deftp {Data Type} log-rotation
10576 Data type representing the rotation of a group of log files.
10578 Taking an example from the Rottlog manual (@pxref{Period Related File
10579 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
10585 (files '("/var/log/apache/*"))
10586 (options '("storedir apache-archives"
10592 The list of fields is as follows:
10595 @item @code{frequency} (default: @code{'weekly})
10596 The log rotation frequency, a symbol.
10599 The list of files or file glob patterns to rotate.
10601 @item @code{options} (default: @code{'()})
10602 The list of rottlog options for this rotation (@pxref{Configuration
10603 parameters,,, rottlog, GNU Rot[t]lg Manual}).
10605 @item @code{post-rotate} (default: @code{#f})
10606 Either @code{#f} or a gexp to execute once the rotation has completed.
10610 @defvr {Scheme Variable} %default-rotations
10611 Specifies weekly rotation of @var{%rotated-files} and
10612 a couple of other files.
10615 @defvr {Scheme Variable} %rotated-files
10616 The list of syslog-controlled files to be rotated. By default it is:
10617 @code{'("/var/log/messages" "/var/log/secure")}.
10620 @node Networking Services
10621 @subsubsection Networking Services
10623 The @code{(gnu services networking)} module provides services to configure
10624 the network interface.
10626 @cindex DHCP, networking service
10627 @deffn {Scheme Procedure} dhcp-client-service [#:dhcp @var{isc-dhcp}]
10628 Return a service that runs @var{dhcp}, a Dynamic Host Configuration
10629 Protocol (DHCP) client, on all the non-loopback network interfaces.
10632 @defvr {Scheme Variable} static-networking-service-type
10633 This is the type for statically-configured network interfaces.
10634 @c TODO Document <static-networking> data structures.
10637 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
10638 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}]
10639 [#:requirement @code{'(udev)}]
10640 Return a service that starts @var{interface} with address @var{ip}. If
10641 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
10642 it must be a string specifying the default network gateway. @var{requirement}
10643 can be used to declare a dependency on another service before configuring the
10646 This procedure can be called several times, one for each network
10647 interface of interest. Behind the scenes what it does is extend
10648 @code{static-networking-service-type} with additional network interfaces
10655 @cindex network management
10656 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
10657 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
10658 management daemon that aims to simplify wired and wireless networking.
10660 This service adds the @var{wicd} package to the global profile, providing
10661 several commands to interact with the daemon and configure networking:
10662 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
10663 and @command{wicd-curses} user interfaces.
10666 @cindex NetworkManager
10668 @defvr {Scheme Variable} network-manager-service-type
10669 This is the service type for the
10670 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
10671 service. The value for this service type is a
10672 @code{network-manager-configuration} record.
10674 This service is part of @code{%desktop-services} (@pxref{Desktop
10678 @deftp {Data Type} network-manager-configuration
10679 Data type representing the configuration of NetworkManager.
10682 @item @code{network-manager} (default: @code{network-manager})
10683 The NetworkManager package to use.
10685 @item @code{dns} (default: @code{"default"})
10686 Processing mode for DNS, which affects how NetworkManager uses the
10687 @code{resolv.conf} configuration file.
10691 NetworkManager will update @code{resolv.conf} to reflect the nameservers
10692 provided by currently active connections.
10695 NetworkManager will run @code{dnsmasq} as a local caching nameserver,
10696 using a "split DNS" configuration if you are connected to a VPN, and
10697 then update @code{resolv.conf} to point to the local nameserver.
10700 NetworkManager will not modify @code{resolv.conf}.
10703 @item @code{vpn-plugins} (default: @code{'()})
10704 This is the list of available plugins for virtual private networks
10705 (VPNs). An example of this is the @code{network-manager-openvpn}
10706 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
10712 @deffn {Scheme Variable} connman-service-type
10713 This is the service type to run @url{https://01.org/connman,Connman},
10714 a network connection manager.
10716 Its value must be an
10717 @code{connman-configuration} record as in this example:
10720 (service connman-service-type
10721 (connman-configuration
10722 (disable-vpn? #t)))
10725 See below for details about @code{connman-configuration}.
10728 @deftp {Data Type} connman-configuration
10729 Data Type representing the configuration of connman.
10732 @item @code{connman} (default: @var{connman})
10733 The connman package to use.
10735 @item @code{disable-vpn?} (default: @code{#f})
10736 When true, enable connman's vpn plugin.
10740 @cindex WPA Supplicant
10741 @defvr {Scheme Variable} wpa-supplicant-service-type
10742 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
10743 supplicant}, an authentication daemon required to authenticate against
10744 encrypted WiFi or ethernet networks. It is configured to listen for
10747 The value of this service is the @code{wpa-supplicant} package to use.
10748 Thus, it can be instantiated like this:
10751 (use-modules (gnu services networking))
10753 (service wpa-supplicant-service-type)
10758 @cindex real time clock
10759 @deffn {Scheme Procedure} ntp-service [#:ntp @var{ntp}] @
10760 [#:servers @var{%ntp-servers}] @
10761 [#:allow-large-adjustment? #f]
10762 Return a service that runs the daemon from @var{ntp}, the
10763 @uref{http://www.ntp.org, Network Time Protocol package}. The daemon will
10764 keep the system clock synchronized with that of @var{servers}.
10765 @var{allow-large-adjustment?} determines whether @command{ntpd} is allowed to
10766 make an initial adjustment of more than 1,000 seconds.
10769 @defvr {Scheme Variable} %ntp-servers
10770 List of host names used as the default NTP servers.
10774 @deffn {Scheme Procedure} openntpd-service-type
10775 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
10776 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
10777 clock synchronized with that of the given servers.
10781 openntpd-service-type
10782 (openntpd-configuration
10783 (listen-on '("127.0.0.1" "::1"))
10784 (sensor '("udcf0 correction 70000"))
10785 (constraint-from '("www.gnu.org"))
10786 (constraints-from '("https://www.google.com/"))
10787 (allow-large-adjustment? #t)))
10792 @deftp {Data Type} openntpd-configuration
10794 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
10795 The openntpd executable to use.
10796 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
10797 A list of local IP addresses or hostnames the ntpd daemon should listen on.
10798 @item @code{query-from} (default: @code{'()})
10799 A list of local IP address the ntpd daemon should use for outgoing queries.
10800 @item @code{sensor} (default: @code{'()})
10801 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
10802 will listen to each sensor that acutally exists and ignore non-existant ones.
10803 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
10805 @item @code{server} (default: @var{%ntp-servers})
10806 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
10807 @item @code{servers} (default: @code{'()})
10808 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
10809 @item @code{constraint-from} (default: @code{'()})
10810 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
10811 This time information is not used for precision but acts as an authenticated
10812 constraint, thereby reducing the impact of unauthenticated NTP
10813 man-in-the-middle attacks.
10814 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
10816 @item @code{constraints-from} (default: @code{'()})
10817 As with constraint from, specify a list of URLs, IP addresses or hostnames of
10818 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
10819 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
10820 @item @code{allow-large-adjustment?} (default: @code{#f})
10821 Determines if @code{ntpd} is allowed to make an initial adjustment of more
10827 @deffn {Scheme variable} inetd-service-type
10828 This service runs the @command{inetd} (@pxref{inetd invocation,,,
10829 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
10830 connections on internet sockets, and lazily starts the specified server
10831 program when a connection is made on one of these sockets.
10833 The value of this service is an @code{inetd-configuration} object. The
10834 following example configures the @command{inetd} daemon to provide the
10835 built-in @command{echo} service, as well as an smtp service which
10836 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
10837 gateway @code{hostname}:
10842 (inetd-configuration
10846 (socket-type 'stream)
10853 (socket-type 'stream)
10857 (program (file-append openssh "/bin/ssh"))
10859 '("ssh" "-qT" "-i" "/path/to/ssh_key"
10860 "-W" "smtp-server:25" "user@@hostname")))))
10863 See below for more details about @code{inetd-configuration}.
10866 @deftp {Data Type} inetd-configuration
10867 Data type representing the configuration of @command{inetd}.
10870 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
10871 The @command{inetd} executable to use.
10873 @item @code{entries} (default: @code{'()})
10874 A list of @command{inetd} service entries. Each entry should be created
10875 by the @code{inetd-entry} constructor.
10879 @deftp {Data Type} inetd-entry
10880 Data type representing an entry in the @command{inetd} configuration.
10881 Each entry corresponds to a socket where @command{inetd} will listen for
10885 @item @code{node} (default: @code{#f})
10886 Optional string, a comma-separated list of local addresses
10887 @command{inetd} should use when listening for this service.
10888 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
10889 description of all options.
10891 A string, the name must correspond to an entry in @code{/etc/services}.
10892 @item @code{socket-type}
10893 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
10895 @item @code{protocol}
10896 A string, must correspond to an entry in @code{/etc/protocols}.
10897 @item @code{wait?} (default: @code{#t})
10898 Whether @command{inetd} should wait for the server to exit before
10899 listening to new service requests.
10901 A string containing the user (and, optionally, group) name of the user
10902 as whom the server should run. The group name can be specified in a
10903 suffix, separated by a colon or period, i.e. @code{"user"},
10904 @code{"user:group"} or @code{"user.group"}.
10905 @item @code{program} (default: @code{"internal"})
10906 The server program which will serve the requests, or @code{"internal"}
10907 if @command{inetd} should use a built-in service.
10908 @item @code{arguments} (default: @code{'()})
10909 A list strings or file-like objects, which are the server program's
10910 arguments, starting with the zeroth argument, i.e. the name of the
10911 program itself. For @command{inetd}'s internal services, this entry
10912 must be @code{'()} or @code{'("internal")}.
10915 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
10916 detailed discussion of each configuration field.
10920 @deffn {Scheme Procedure} tor-service [@var{config-file}] [#:tor @var{tor}]
10921 Return a service to run the @uref{https://torproject.org, Tor} anonymous
10924 The daemon runs as the @code{tor} unprivileged user. It is passed
10925 @var{config-file}, a file-like object, with an additional @code{User tor} line
10926 and lines for hidden services added via @code{tor-hidden-service}. Run
10927 @command{man tor} for information about the configuration file.
10930 @cindex hidden service
10931 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
10932 Define a new Tor @dfn{hidden service} called @var{name} and implementing
10933 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
10936 '((22 "127.0.0.1:22")
10937 (80 "127.0.0.1:8080"))
10940 In this example, port 22 of the hidden service is mapped to local port 22, and
10941 port 80 is mapped to local port 8080.
10943 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
10944 the @file{hostname} file contains the @code{.onion} host name for the hidden
10947 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
10948 project's documentation} for more information.
10951 The @code{(gnu services rsync)} module provides the following services:
10953 You might want an rsync daemon if you have files that you want available
10954 so anyone (or just yourself) can download existing files or upload new
10957 @deffn {Scheme Variable} rsync-service-type
10958 This is the type for the @uref{https://rsync.samba.org, rsync} rsync daemon,
10959 @command{rsync-configuration} record as in this example:
10962 (service rsync-service-type)
10965 See below for details about @code{rsync-configuration}.
10968 @deftp {Data Type} rsync-configuration
10969 Data type representing the configuration for @code{rsync-service}.
10972 @item @code{package} (default: @var{rsync})
10973 @code{rsync} package to use.
10975 @item @code{port-number} (default: @code{873})
10976 TCP port on which @command{rsync} listens for incoming connections. If port
10977 is less than @code{1024} @command{rsync} needs to be started as the
10978 @code{root} user and group.
10980 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
10981 Name of the file where @command{rsync} writes its PID.
10983 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
10984 Name of the file where @command{rsync} writes its lock file.
10986 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
10987 Name of the file where @command{rsync} writes its log file.
10989 @item @code{use-chroot?} (default: @var{#t})
10990 Whether to use chroot for @command{rsync} shared directory.
10992 @item @code{share-path} (default: @file{/srv/rsync})
10993 Location of the @command{rsync} shared directory.
10995 @item @code{share-comment} (default: @code{"Rsync share"})
10996 Comment of the @command{rsync} shared directory.
10998 @item @code{read-only?} (default: @var{#f})
10999 Read-write permissions to shared directory.
11001 @item @code{timeout} (default: @code{300})
11002 I/O timeout in seconds.
11004 @item @code{user} (default: @var{"root"})
11005 Owner of the @code{rsync} process.
11007 @item @code{group} (default: @var{"root"})
11008 Group of the @code{rsync} process.
11010 @item @code{uid} (default: @var{"rsyncd"})
11011 User name or user ID that file transfers to and from that module should take
11012 place as when the daemon was run as @code{root}.
11014 @item @code{gid} (default: @var{"rsyncd"})
11015 Group name or group ID that will be used when accessing the module.
11020 Furthermore, @code{(gnu services ssh)} provides the following services.
11024 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
11025 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
11026 [#:allow-empty-passwords? #f] [#:root-login? #f] @
11027 [#:syslog-output? #t] [#:x11-forwarding? #t] @
11028 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
11029 [#:public-key-authentication? #t] [#:initialize? #t]
11030 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
11031 @var{host-key} must designate a file containing the host key, and readable
11034 When @var{daemonic?} is true, @command{lshd} will detach from the
11035 controlling terminal and log its output to syslogd, unless one sets
11036 @var{syslog-output?} to false. Obviously, it also makes lsh-service
11037 depend on existence of syslogd service. When @var{pid-file?} is true,
11038 @command{lshd} writes its PID to the file called @var{pid-file}.
11040 When @var{initialize?} is true, automatically create the seed and host key
11041 upon service activation if they do not exist yet. This may take long and
11042 require interaction.
11044 When @var{initialize?} is false, it is up to the user to initialize the
11045 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
11046 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
11047 basics,,, lsh, LSH Manual}).
11049 When @var{interfaces} is empty, lshd listens for connections on all the
11050 network interfaces; otherwise, @var{interfaces} must be a list of host names
11053 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
11054 passwords, and @var{root-login?} specifies whether to accept log-ins as
11057 The other options should be self-descriptive.
11062 @deffn {Scheme Variable} openssh-service-type
11063 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
11064 shell daemon, @command{sshd}. Its value must be an
11065 @code{openssh-configuration} record as in this example:
11068 (service openssh-service-type
11069 (openssh-configuration
11070 (x11-forwarding? #t)
11071 (permit-root-login 'without-password)
11073 `(("alice" ,(local-file "alice.pub"))
11074 ("bob" ,(local-file "bob.pub"))))))
11077 See below for details about @code{openssh-configuration}.
11079 This service can be extended with extra authorized keys, as in this
11083 (service-extension openssh-service-type
11084 (const `(("charlie"
11085 ,(local-file "charlie.pub")))))
11089 @deftp {Data Type} openssh-configuration
11090 This is the configuration record for OpenSSH's @command{sshd}.
11093 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
11094 Name of the file where @command{sshd} writes its PID.
11096 @item @code{port-number} (default: @code{22})
11097 TCP port on which @command{sshd} listens for incoming connections.
11099 @item @code{permit-root-login} (default: @code{#f})
11100 This field determines whether and when to allow logins as root. If
11101 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
11102 If it's the symbol @code{'without-password}, then root logins are
11103 permitted but not with password-based authentication.
11105 @item @code{allow-empty-passwords?} (default: @code{#f})
11106 When true, users with empty passwords may log in. When false, they may
11109 @item @code{password-authentication?} (default: @code{#t})
11110 When true, users may log in with their password. When false, they have
11111 other authentication methods.
11113 @item @code{public-key-authentication?} (default: @code{#t})
11114 When true, users may log in using public key authentication. When
11115 false, users have to use other authentication method.
11117 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
11118 This is used only by protocol version 2.
11120 @item @code{x11-forwarding?} (default: @code{#f})
11121 When true, forwarding of X11 graphical client connections is
11122 enabled---in other words, @command{ssh} options @option{-X} and
11123 @option{-Y} will work.
11125 @item @code{challenge-response-authentication?} (default: @code{#f})
11126 Specifies whether challenge response authentication is allowed (e.g. via
11129 @item @code{use-pam?} (default: @code{#t})
11130 Enables the Pluggable Authentication Module interface. If set to
11131 @code{#t}, this will enable PAM authentication using
11132 @code{challenge-response-authentication?} and
11133 @code{password-authentication?}, in addition to PAM account and session
11134 module processing for all authentication types.
11136 Because PAM challenge response authentication usually serves an
11137 equivalent role to password authentication, you should disable either
11138 @code{challenge-response-authentication?} or
11139 @code{password-authentication?}.
11141 @item @code{print-last-log?} (default: @code{#t})
11142 Specifies whether @command{sshd} should print the date and time of the
11143 last user login when a user logs in interactively.
11145 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
11146 Configures external subsystems (e.g. file transfer daemon).
11148 This is a list of two-element lists, each of which containing the
11149 subsystem name and a command (with optional arguments) to execute upon
11152 The command @command{internal-sftp} implements an in-process SFTP
11153 server. Alternately, one can specify the @command{sftp-server} command:
11155 (service openssh-service-type
11156 (openssh-configuration
11158 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
11161 @item @code{authorized-keys} (default: @code{'()})
11162 @cindex authorized keys, SSH
11163 @cindex SSH authorized keys
11164 This is the list of authorized keys. Each element of the list is a user
11165 name followed by one or more file-like objects that represent SSH public
11169 (openssh-configuration
11171 `(("rekado" ,(local-file "rekado.pub"))
11172 ("chris" ,(local-file "chris.pub"))
11173 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
11177 registers the specified public keys for user accounts @code{rekado},
11178 @code{chris}, and @code{root}.
11180 Additional authorized keys can be specified @i{via}
11181 @code{service-extension}.
11183 Note that this does @emph{not} interfere with the use of
11184 @file{~/.ssh/authorized_keys}.
11188 @deffn {Scheme Procedure} dropbear-service [@var{config}]
11189 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
11190 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
11193 For example, to specify a Dropbear service listening on port 1234, add
11194 this call to the operating system's @code{services} field:
11197 (dropbear-service (dropbear-configuration
11198 (port-number 1234)))
11202 @deftp {Data Type} dropbear-configuration
11203 This data type represents the configuration of a Dropbear SSH daemon.
11206 @item @code{dropbear} (default: @var{dropbear})
11207 The Dropbear package to use.
11209 @item @code{port-number} (default: 22)
11210 The TCP port where the daemon waits for incoming connections.
11212 @item @code{syslog-output?} (default: @code{#t})
11213 Whether to enable syslog output.
11215 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
11216 File name of the daemon's PID file.
11218 @item @code{root-login?} (default: @code{#f})
11219 Whether to allow @code{root} logins.
11221 @item @code{allow-empty-passwords?} (default: @code{#f})
11222 Whether to allow empty passwords.
11224 @item @code{password-authentication?} (default: @code{#t})
11225 Whether to enable password-based authentication.
11229 @defvr {Scheme Variable} %facebook-host-aliases
11230 This variable contains a string for use in @file{/etc/hosts}
11231 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
11232 line contains a entry that maps a known server name of the Facebook
11233 on-line service---e.g., @code{www.facebook.com}---to the local
11234 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
11236 This variable is typically used in the @code{hosts-file} field of an
11237 @code{operating-system} declaration (@pxref{operating-system Reference,
11238 @file{/etc/hosts}}):
11241 (use-modules (gnu) (guix))
11244 (host-name "mymachine")
11247 ;; Create a /etc/hosts file with aliases for "localhost"
11248 ;; and "mymachine", as well as for Facebook servers.
11249 (plain-file "hosts"
11250 (string-append (local-host-aliases host-name)
11251 %facebook-host-aliases))))
11254 This mechanism can prevent programs running locally, such as Web
11255 browsers, from accessing Facebook.
11258 The @code{(gnu services avahi)} provides the following definition.
11260 @deffn {Scheme Procedure} avahi-service [#:avahi @var{avahi}] @
11261 [#:host-name #f] [#:publish? #t] [#:ipv4? #t] @
11262 [#:ipv6? #t] [#:wide-area? #f] @
11263 [#:domains-to-browse '()] [#:debug? #f]
11264 Return a service that runs @command{avahi-daemon}, a system-wide
11265 mDNS/DNS-SD responder that allows for service discovery and
11266 "zero-configuration" host name lookups (see @uref{http://avahi.org/}), and
11267 extends the name service cache daemon (nscd) so that it can resolve
11268 @code{.local} host names using
11269 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. Additionally,
11270 add the @var{avahi} package to the system profile so that commands such as
11271 @command{avahi-browse} are directly usable.
11273 If @var{host-name} is different from @code{#f}, use that as the host name to
11274 publish for this machine; otherwise, use the machine's actual host name.
11276 When @var{publish?} is true, publishing of host names and services is allowed;
11277 in particular, avahi-daemon will publish the machine's host name and IP
11278 address via mDNS on the local network.
11280 When @var{wide-area?} is true, DNS-SD over unicast DNS is enabled.
11282 Boolean values @var{ipv4?} and @var{ipv6?} determine whether to use IPv4/IPv6
11286 @deffn {Scheme Variable} openvswitch-service-type
11287 This is the type of the @uref{http://www.openvswitch.org, Open vSwitch}
11288 service, whose value should be an @code{openvswitch-configuration}
11292 @deftp {Data Type} openvswitch-configuration
11293 Data type representing the configuration of Open vSwitch, a multilayer
11294 virtual switch which is designed to enable massive network automation
11295 through programmatic extension.
11298 @item @code{package} (default: @var{openvswitch})
11299 Package object of the Open vSwitch.
11305 @subsubsection X Window
11308 @cindex X Window System
11309 @cindex login manager
11310 Support for the X Window graphical display system---specifically
11311 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
11312 there is no @code{xorg-service} procedure. Instead, the X server is
11313 started by the @dfn{login manager}, by default SLiM.
11315 @cindex window manager
11316 To use X11, you must install at least one @dfn{window manager}---for
11317 example the @code{windowmaker} or @code{openbox} packages---preferably
11318 by adding it to the @code{packages} field of your operating system
11319 definition (@pxref{operating-system Reference, system-wide packages}).
11321 @defvr {Scheme Variable} slim-service-type
11322 This is the type for the SLiM graphical login manager for X11.
11324 @cindex session types (X11)
11325 @cindex X11 session types
11326 SLiM looks for @dfn{session types} described by the @file{.desktop} files in
11327 @file{/run/current-system/profile/share/xsessions} and allows users to
11328 choose a session from the log-in screen using @kbd{F1}. Packages such
11329 as @code{xfce}, @code{sawfish}, and @code{ratpoison} provide
11330 @file{.desktop} files; adding them to the system-wide set of packages
11331 automatically makes them available at the log-in screen.
11333 In addition, @file{~/.xsession} files are honored. When available,
11334 @file{~/.xsession} must be an executable that starts a window manager
11335 and/or other X clients.
11338 @deftp {Data Type} slim-configuration
11339 Data type representing the configuration of @code{slim-service-type}.
11342 @item @code{allow-empty-passwords?} (default: @code{#t})
11343 Whether to allow logins with empty passwords.
11345 @item @code{auto-login?} (default: @code{#f})
11346 @itemx @code{default-user} (default: @code{""})
11347 When @code{auto-login?} is false, SLiM presents a log-in screen.
11349 When @code{auto-login?} is true, SLiM logs in directly as
11350 @code{default-user}.
11352 @item @code{theme} (default: @code{%default-slim-theme})
11353 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
11354 The graphical theme to use and its name.
11356 @item @code{auto-login-session} (default: @code{#f})
11357 If true, this must be the name of the executable to start as the default
11358 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
11360 If false, a session described by one of the available @file{.desktop}
11361 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
11365 You must install at least one window manager in the system profile or in
11366 your user profile. Failing to do that, if @code{auto-login-session} is
11367 false, you will be unable to log in.
11370 @item @code{startx} (default: @code{(xorg-start-command)})
11371 The command used to start the X11 graphical server.
11373 @item @code{xauth} (default: @code{xauth})
11374 The XAuth package to use.
11376 @item @code{shepherd} (default: @code{shepherd})
11377 The Shepherd package used when invoking @command{halt} and
11380 @item @code{sessreg} (default: @code{sessreg})
11381 The sessreg package used in order to register the session.
11383 @item @code{slim} (default: @code{slim})
11384 The SLiM package to use.
11388 @defvr {Scheme Variable} %default-theme
11389 @defvrx {Scheme Variable} %default-theme-name
11390 The default SLiM theme and its name.
11394 @deftp {Data Type} sddm-configuration
11395 This is the data type representing the sddm service configuration.
11398 @item @code{display-server} (default: "x11")
11399 Select display server to use for the greeter. Valid values are "x11"
11402 @item @code{numlock} (default: "on")
11403 Valid values are "on", "off" or "none".
11405 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
11406 Command to run when halting.
11408 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
11409 Command to run when rebooting.
11411 @item @code{theme} (default "maldives")
11412 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
11414 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
11415 Directory to look for themes.
11417 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
11418 Directory to look for faces.
11420 @item @code{default-path} (default "/run/current-system/profile/bin")
11421 Default PATH to use.
11423 @item @code{minimum-uid} (default 1000)
11424 Minimum UID to display in SDDM.
11426 @item @code{maximum-uid} (default 2000)
11427 Maximum UID to display in SDDM
11429 @item @code{remember-last-user?} (default #t)
11430 Remember last user.
11432 @item @code{remember-last-session?} (default #t)
11433 Remember last session.
11435 @item @code{hide-users} (default "")
11436 Usernames to hide from SDDM greeter.
11438 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
11439 Users with shells listed will be hidden from the SDDM greeter.
11441 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
11442 Script to run before starting a wayland session.
11444 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
11445 Directory to look for desktop files starting wayland sessions.
11447 @item @code{xorg-server-path} (default @code{xorg-start-command})
11448 Path to xorg-server.
11450 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
11453 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
11456 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
11457 Script to run after starting xorg-server.
11459 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
11460 Script to run before stopping xorg-server.
11462 @item @code{xsession-command} (default: @code{xinitr })
11463 Script to run before starting a X session.
11465 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
11466 Directory to look for desktop files starting X sessions.
11468 @item @code{minimum-vt} (default: 7)
11471 @item @code{xserver-arguments} (default "-nolisten tcp")
11472 Arguments to pass to xorg-server.
11474 @item @code{auto-login-user} (default "")
11475 User to use for auto-login.
11477 @item @code{auto-login-session} (default "")
11478 Desktop file to use for auto-login.
11480 @item @code{relogin?} (default #f)
11481 Relogin after logout.
11486 @cindex login manager
11488 @deffn {Scheme Procedure} sddm-service config
11489 Return a service that spawns the SDDM graphical login manager for config of
11490 type @code{<sddm-configuration>}.
11493 (sddm-service (sddm-configuration
11494 (auto-login-user "Alice")
11495 (auto-login-session "xfce.desktop")))
11499 @deffn {Scheme Procedure} xorg-start-command [#:guile] @
11500 [#:modules %default-xorg-modules] @
11501 [#:fonts %default-xorg-fonts] @
11502 [#:configuration-file (xorg-configuration-file @dots{})] @
11503 [#:xorg-server @var{xorg-server}]
11504 Return a @code{startx} script in which @var{modules}, a list of X module
11505 packages, and @var{fonts}, a list of X font directories, are available. See
11506 @code{xorg-wrapper} for more details on the arguments. The result should be
11507 used in place of @code{startx}.
11509 Usually the X server is started by a login manager.
11512 @deffn {Scheme Procedure} xorg-configuration-file @
11513 [#:modules %default-xorg-modules] @
11514 [#:fonts %default-xorg-fonts] @
11515 [#:drivers '()] [#:resolutions '()] [#:extra-config '()]
11516 Return a configuration file for the Xorg server containing search paths for
11517 all the common drivers.
11519 @var{modules} must be a list of @dfn{module packages} loaded by the Xorg
11520 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
11521 @var{fonts} must be a list of font directories to add to the server's
11524 @var{drivers} must be either the empty list, in which case Xorg chooses a
11525 graphics driver automatically, or a list of driver names that will be tried in
11526 this order---e.g., @code{("modesetting" "vesa")}.
11528 Likewise, when @var{resolutions} is the empty list, Xorg chooses an
11529 appropriate screen resolution; otherwise, it must be a list of
11530 resolutions---e.g., @code{((1024 768) (640 480))}.
11532 Last, @var{extra-config} is a list of strings or objects appended to the
11533 configuration file. It is used to pass extra text to be
11534 added verbatim to the configuration file.
11537 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
11538 Add @var{package}, a package for a screen locker or screen saver whose
11539 command is @var{program}, to the set of setuid programs and add a PAM entry
11540 for it. For example:
11543 (screen-locker-service xlockmore "xlock")
11546 makes the good ol' XlockMore usable.
11550 @node Printing Services
11551 @subsubsection Printing Services
11553 @cindex printer support with CUPS
11554 The @code{(gnu services cups)} module provides a Guix service definition
11555 for the CUPS printing service. To add printer support to a GuixSD
11556 system, add a @code{cups-service} to the operating system definition:
11558 @deffn {Scheme Variable} cups-service-type
11559 The service type for the CUPS print server. Its value should be a valid
11560 CUPS configuration (see below). To use the default settings, simply
11563 (service cups-service-type)
11567 The CUPS configuration controls the basic things about your CUPS
11568 installation: what interfaces it listens on, what to do if a print job
11569 fails, how much logging to do, and so on. To actually add a printer,
11570 you have to visit the @url{http://localhost:631} URL, or use a tool such
11571 as GNOME's printer configuration services. By default, configuring a
11572 CUPS service will generate a self-signed certificate if needed, for
11573 secure connections to the print server.
11575 Suppose you want to enable the Web interface of CUPS and also add
11576 support for Epson printers @i{via} the @code{escpr} package and for HP
11577 printers @i{via} the @code{hplip} package. You can do that directly,
11578 like this (you need to use the @code{(gnu packages cups)} module):
11581 (service cups-service-type
11582 (cups-configuration
11583 (web-interface? #t)
11585 (list cups-filters escpr hplip))))
11588 The available configuration parameters follow. Each parameter
11589 definition is preceded by its type; for example, @samp{string-list foo}
11590 indicates that the @code{foo} parameter should be specified as a list of
11591 strings. There is also a way to specify the configuration as a string,
11592 if you have an old @code{cupsd.conf} file that you want to port over
11593 from some other system; see the end for more details.
11595 @c The following documentation was initially generated by
11596 @c (generate-documentation) in (gnu services cups). Manually maintained
11597 @c documentation is better, so we shouldn't hesitate to edit below as
11598 @c needed. However if the change you want to make to this documentation
11599 @c can be done in an automated way, it's probably easier to change
11600 @c (generate-documentation) than to make it below and have to deal with
11601 @c the churn as CUPS updates.
11604 Available @code{cups-configuration} fields are:
11606 @deftypevr {@code{cups-configuration} parameter} package cups
11610 @deftypevr {@code{cups-configuration} parameter} package-list extensions
11611 Drivers and other extensions to the CUPS package.
11614 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
11615 Configuration of where to write logs, what directories to use for print
11616 spools, and related privileged configuration parameters.
11618 Available @code{files-configuration} fields are:
11620 @deftypevr {@code{files-configuration} parameter} log-location access-log
11621 Defines the access log filename. Specifying a blank filename disables
11622 access log generation. The value @code{stderr} causes log entries to be
11623 sent to the standard error file when the scheduler is running in the
11624 foreground, or to the system log daemon when run in the background. The
11625 value @code{syslog} causes log entries to be sent to the system log
11626 daemon. The server name may be included in filenames using the string
11627 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
11629 Defaults to @samp{"/var/log/cups/access_log"}.
11632 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
11633 Where CUPS should cache data.
11635 Defaults to @samp{"/var/cache/cups"}.
11638 @deftypevr {@code{files-configuration} parameter} string config-file-perm
11639 Specifies the permissions for all configuration files that the scheduler
11642 Note that the permissions for the printers.conf file are currently
11643 masked to only allow access from the scheduler user (typically root).
11644 This is done because printer device URIs sometimes contain sensitive
11645 authentication information that should not be generally known on the
11646 system. There is no way to disable this security feature.
11648 Defaults to @samp{"0640"}.
11651 @deftypevr {@code{files-configuration} parameter} log-location error-log
11652 Defines the error log filename. Specifying a blank filename disables
11653 access log generation. The value @code{stderr} causes log entries to be
11654 sent to the standard error file when the scheduler is running in the
11655 foreground, or to the system log daemon when run in the background. The
11656 value @code{syslog} causes log entries to be sent to the system log
11657 daemon. The server name may be included in filenames using the string
11658 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
11660 Defaults to @samp{"/var/log/cups/error_log"}.
11663 @deftypevr {@code{files-configuration} parameter} string fatal-errors
11664 Specifies which errors are fatal, causing the scheduler to exit. The
11669 No errors are fatal.
11672 All of the errors below are fatal.
11675 Browsing initialization errors are fatal, for example failed connections
11676 to the DNS-SD daemon.
11679 Configuration file syntax errors are fatal.
11682 Listen or Port errors are fatal, except for IPv6 failures on the
11683 loopback or @code{any} addresses.
11686 Log file creation or write errors are fatal.
11689 Bad startup file permissions are fatal, for example shared TLS
11690 certificate and key files with world-read permissions.
11693 Defaults to @samp{"all -browse"}.
11696 @deftypevr {@code{files-configuration} parameter} boolean file-device?
11697 Specifies whether the file pseudo-device can be used for new printer
11698 queues. The URI @uref{file:///dev/null} is always allowed.
11700 Defaults to @samp{#f}.
11703 @deftypevr {@code{files-configuration} parameter} string group
11704 Specifies the group name or ID that will be used when executing external
11707 Defaults to @samp{"lp"}.
11710 @deftypevr {@code{files-configuration} parameter} string log-file-perm
11711 Specifies the permissions for all log files that the scheduler writes.
11713 Defaults to @samp{"0644"}.
11716 @deftypevr {@code{files-configuration} parameter} log-location page-log
11717 Defines the page log filename. Specifying a blank filename disables
11718 access log generation. The value @code{stderr} causes log entries to be
11719 sent to the standard error file when the scheduler is running in the
11720 foreground, or to the system log daemon when run in the background. The
11721 value @code{syslog} causes log entries to be sent to the system log
11722 daemon. The server name may be included in filenames using the string
11723 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
11725 Defaults to @samp{"/var/log/cups/page_log"}.
11728 @deftypevr {@code{files-configuration} parameter} string remote-root
11729 Specifies the username that is associated with unauthenticated accesses
11730 by clients claiming to be the root user. The default is @code{remroot}.
11732 Defaults to @samp{"remroot"}.
11735 @deftypevr {@code{files-configuration} parameter} file-name request-root
11736 Specifies the directory that contains print jobs and other HTTP request
11739 Defaults to @samp{"/var/spool/cups"}.
11742 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
11743 Specifies the level of security sandboxing that is applied to print
11744 filters, backends, and other child processes of the scheduler; either
11745 @code{relaxed} or @code{strict}. This directive is currently only
11746 used/supported on macOS.
11748 Defaults to @samp{strict}.
11751 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
11752 Specifies the location of TLS certificates and private keys. CUPS will
11753 look for public and private keys in this directory: a @code{.crt} files
11754 for PEM-encoded certificates and corresponding @code{.key} files for
11755 PEM-encoded private keys.
11757 Defaults to @samp{"/etc/cups/ssl"}.
11760 @deftypevr {@code{files-configuration} parameter} file-name server-root
11761 Specifies the directory containing the server configuration files.
11763 Defaults to @samp{"/etc/cups"}.
11766 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
11767 Specifies whether the scheduler calls fsync(2) after writing
11768 configuration or state files.
11770 Defaults to @samp{#f}.
11773 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
11774 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
11777 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
11778 Specifies the directory where temporary files are stored.
11780 Defaults to @samp{"/var/spool/cups/tmp"}.
11783 @deftypevr {@code{files-configuration} parameter} string user
11784 Specifies the user name or ID that is used when running external
11787 Defaults to @samp{"lp"}.
11791 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
11792 Specifies the logging level for the AccessLog file. The @code{config}
11793 level logs when printers and classes are added, deleted, or modified and
11794 when configuration files are accessed or updated. The @code{actions}
11795 level logs when print jobs are submitted, held, released, modified, or
11796 canceled, and any of the conditions for @code{config}. The @code{all}
11797 level logs all requests.
11799 Defaults to @samp{actions}.
11802 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
11803 Specifies whether to purge job history data automatically when it is no
11804 longer required for quotas.
11806 Defaults to @samp{#f}.
11809 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
11810 Specifies which protocols to use for local printer sharing.
11812 Defaults to @samp{dnssd}.
11815 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
11816 Specifies whether the CUPS web interface is advertised.
11818 Defaults to @samp{#f}.
11821 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
11822 Specifies whether shared printers are advertised.
11824 Defaults to @samp{#f}.
11827 @deftypevr {@code{cups-configuration} parameter} string classification
11828 Specifies the security classification of the server. Any valid banner
11829 name can be used, including "classified", "confidential", "secret",
11830 "topsecret", and "unclassified", or the banner can be omitted to disable
11831 secure printing functions.
11833 Defaults to @samp{""}.
11836 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
11837 Specifies whether users may override the classification (cover page) of
11838 individual print jobs using the @code{job-sheets} option.
11840 Defaults to @samp{#f}.
11843 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
11844 Specifies the default type of authentication to use.
11846 Defaults to @samp{Basic}.
11849 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
11850 Specifies whether encryption will be used for authenticated requests.
11852 Defaults to @samp{Required}.
11855 @deftypevr {@code{cups-configuration} parameter} string default-language
11856 Specifies the default language to use for text and web content.
11858 Defaults to @samp{"en"}.
11861 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
11862 Specifies the default paper size for new print queues. @samp{"Auto"}
11863 uses a locale-specific default, while @samp{"None"} specifies there is
11864 no default paper size. Specific size names are typically
11865 @samp{"Letter"} or @samp{"A4"}.
11867 Defaults to @samp{"Auto"}.
11870 @deftypevr {@code{cups-configuration} parameter} string default-policy
11871 Specifies the default access policy to use.
11873 Defaults to @samp{"default"}.
11876 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
11877 Specifies whether local printers are shared by default.
11879 Defaults to @samp{#t}.
11882 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
11883 Specifies the delay for updating of configuration and state files, in
11884 seconds. A value of 0 causes the update to happen as soon as possible,
11885 typically within a few milliseconds.
11887 Defaults to @samp{30}.
11890 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
11891 Specifies what to do when an error occurs. Possible values are
11892 @code{abort-job}, which will discard the failed print job;
11893 @code{retry-job}, which will retry the job at a later time;
11894 @code{retry-this-job}, which retries the failed job immediately; and
11895 @code{stop-printer}, which stops the printer.
11897 Defaults to @samp{stop-printer}.
11900 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
11901 Specifies the maximum cost of filters that are run concurrently, which
11902 can be used to minimize disk, memory, and CPU resource problems. A
11903 limit of 0 disables filter limiting. An average print to a
11904 non-PostScript printer needs a filter limit of about 200. A PostScript
11905 printer needs about half that (100). Setting the limit below these
11906 thresholds will effectively limit the scheduler to printing a single job
11909 Defaults to @samp{0}.
11912 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
11913 Specifies the scheduling priority of filters that are run to print a
11914 job. The nice value ranges from 0, the highest priority, to 19, the
11917 Defaults to @samp{0}.
11920 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
11921 Specifies whether to do reverse lookups on connecting clients. The
11922 @code{double} setting causes @code{cupsd} to verify that the hostname
11923 resolved from the address matches one of the addresses returned for that
11924 hostname. Double lookups also prevent clients with unregistered
11925 addresses from connecting to your server. Only set this option to
11926 @code{#t} or @code{double} if absolutely required.
11928 Defaults to @samp{#f}.
11931 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
11932 Specifies the number of seconds to wait before killing the filters and
11933 backend associated with a canceled or held job.
11935 Defaults to @samp{30}.
11938 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
11939 Specifies the interval between retries of jobs in seconds. This is
11940 typically used for fax queues but can also be used with normal print
11941 queues whose error policy is @code{retry-job} or
11942 @code{retry-current-job}.
11944 Defaults to @samp{30}.
11947 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
11948 Specifies the number of retries that are done for jobs. This is
11949 typically used for fax queues but can also be used with normal print
11950 queues whose error policy is @code{retry-job} or
11951 @code{retry-current-job}.
11953 Defaults to @samp{5}.
11956 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
11957 Specifies whether to support HTTP keep-alive connections.
11959 Defaults to @samp{#t}.
11962 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
11963 Specifies how long an idle client connection remains open, in seconds.
11965 Defaults to @samp{30}.
11968 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
11969 Specifies the maximum size of print files, IPP requests, and HTML form
11970 data. A limit of 0 disables the limit check.
11972 Defaults to @samp{0}.
11975 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
11976 Listens on the specified interfaces for connections. Valid values are
11977 of the form @var{address}:@var{port}, where @var{address} is either an
11978 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
11979 indicate all addresses. Values can also be file names of local UNIX
11980 domain sockets. The Listen directive is similar to the Port directive
11981 but allows you to restrict access to specific interfaces or networks.
11984 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
11985 Specifies the number of pending connections that will be allowed. This
11986 normally only affects very busy servers that have reached the MaxClients
11987 limit, but can also be triggered by large numbers of simultaneous
11988 connections. When the limit is reached, the operating system will
11989 refuse additional connections until the scheduler can accept the pending
11992 Defaults to @samp{128}.
11995 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
11996 Specifies a set of additional access controls.
11998 Available @code{location-access-controls} fields are:
12000 @deftypevr {@code{location-access-controls} parameter} file-name path
12001 Specifies the URI path to which the access control applies.
12004 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
12005 Access controls for all access to this path, in the same format as the
12006 @code{access-controls} of @code{operation-access-control}.
12008 Defaults to @samp{()}.
12011 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
12012 Access controls for method-specific access to this path.
12014 Defaults to @samp{()}.
12016 Available @code{method-access-controls} fields are:
12018 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
12019 If @code{#t}, apply access controls to all methods except the listed
12020 methods. Otherwise apply to only the listed methods.
12022 Defaults to @samp{#f}.
12025 @deftypevr {@code{method-access-controls} parameter} method-list methods
12026 Methods to which this access control applies.
12028 Defaults to @samp{()}.
12031 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
12032 Access control directives, as a list of strings. Each string should be
12033 one directive, such as "Order allow,deny".
12035 Defaults to @samp{()}.
12040 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
12041 Specifies the number of debugging messages that are retained for logging
12042 if an error occurs in a print job. Debug messages are logged regardless
12043 of the LogLevel setting.
12045 Defaults to @samp{100}.
12048 @deftypevr {@code{cups-configuration} parameter} log-level log-level
12049 Specifies the level of logging for the ErrorLog file. The value
12050 @code{none} stops all logging while @code{debug2} logs everything.
12052 Defaults to @samp{info}.
12055 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
12056 Specifies the format of the date and time in the log files. The value
12057 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
12059 Defaults to @samp{standard}.
12062 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
12063 Specifies the maximum number of simultaneous clients that are allowed by
12066 Defaults to @samp{100}.
12069 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
12070 Specifies the maximum number of simultaneous clients that are allowed
12071 from a single address.
12073 Defaults to @samp{100}.
12076 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
12077 Specifies the maximum number of copies that a user can print of each
12080 Defaults to @samp{9999}.
12083 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
12084 Specifies the maximum time a job may remain in the @code{indefinite}
12085 hold state before it is canceled. A value of 0 disables cancellation of
12088 Defaults to @samp{0}.
12091 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
12092 Specifies the maximum number of simultaneous jobs that are allowed. Set
12093 to 0 to allow an unlimited number of jobs.
12095 Defaults to @samp{500}.
12098 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
12099 Specifies the maximum number of simultaneous jobs that are allowed per
12100 printer. A value of 0 allows up to MaxJobs jobs per printer.
12102 Defaults to @samp{0}.
12105 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
12106 Specifies the maximum number of simultaneous jobs that are allowed per
12107 user. A value of 0 allows up to MaxJobs jobs per user.
12109 Defaults to @samp{0}.
12112 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
12113 Specifies the maximum time a job may take to print before it is
12114 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
12116 Defaults to @samp{10800}.
12119 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
12120 Specifies the maximum size of the log files before they are rotated, in
12121 bytes. The value 0 disables log rotation.
12123 Defaults to @samp{1048576}.
12126 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
12127 Specifies the maximum amount of time to allow between files in a
12128 multiple file print job, in seconds.
12130 Defaults to @samp{300}.
12133 @deftypevr {@code{cups-configuration} parameter} string page-log-format
12134 Specifies the format of PageLog lines. Sequences beginning with percent
12135 (@samp{%}) characters are replaced with the corresponding information,
12136 while all other characters are copied literally. The following percent
12137 sequences are recognized:
12141 insert a single percent character
12144 insert the value of the specified IPP attribute
12147 insert the number of copies for the current page
12150 insert the current page number
12153 insert the current date and time in common log format
12159 insert the printer name
12162 insert the username
12165 A value of the empty string disables page logging. The string @code{%p
12166 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
12167 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
12170 Defaults to @samp{""}.
12173 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
12174 Passes the specified environment variable(s) to child processes; a list
12177 Defaults to @samp{()}.
12180 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
12181 Specifies named access control policies.
12183 Available @code{policy-configuration} fields are:
12185 @deftypevr {@code{policy-configuration} parameter} string name
12186 Name of the policy.
12189 @deftypevr {@code{policy-configuration} parameter} string job-private-access
12190 Specifies an access list for a job's private values. @code{@@ACL} maps
12191 to the printer's requesting-user-name-allowed or
12192 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
12193 owner. @code{@@SYSTEM} maps to the groups listed for the
12194 @code{system-group} field of the @code{files-config} configuration,
12195 which is reified into the @code{cups-files.conf(5)} file. Other
12196 possible elements of the access list include specific user names, and
12197 @code{@@@var{group}} to indicate members of a specific group. The
12198 access list may also be simply @code{all} or @code{default}.
12200 Defaults to @samp{"@@OWNER @@SYSTEM"}.
12203 @deftypevr {@code{policy-configuration} parameter} string job-private-values
12204 Specifies the list of job values to make private, or @code{all},
12205 @code{default}, or @code{none}.
12207 Defaults to @samp{"job-name job-originating-host-name
12208 job-originating-user-name phone"}.
12211 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
12212 Specifies an access list for a subscription's private values.
12213 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
12214 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
12215 owner. @code{@@SYSTEM} maps to the groups listed for the
12216 @code{system-group} field of the @code{files-config} configuration,
12217 which is reified into the @code{cups-files.conf(5)} file. Other
12218 possible elements of the access list include specific user names, and
12219 @code{@@@var{group}} to indicate members of a specific group. The
12220 access list may also be simply @code{all} or @code{default}.
12222 Defaults to @samp{"@@OWNER @@SYSTEM"}.
12225 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
12226 Specifies the list of job values to make private, or @code{all},
12227 @code{default}, or @code{none}.
12229 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
12230 notify-subscriber-user-name notify-user-data"}.
12233 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
12234 Access control by IPP operation.
12236 Defaults to @samp{()}.
12240 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
12241 Specifies whether job files (documents) are preserved after a job is
12242 printed. If a numeric value is specified, job files are preserved for
12243 the indicated number of seconds after printing. Otherwise a boolean
12244 value applies indefinitely.
12246 Defaults to @samp{86400}.
12249 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
12250 Specifies whether the job history is preserved after a job is printed.
12251 If a numeric value is specified, the job history is preserved for the
12252 indicated number of seconds after printing. If @code{#t}, the job
12253 history is preserved until the MaxJobs limit is reached.
12255 Defaults to @samp{#t}.
12258 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
12259 Specifies the amount of time to wait for job completion before
12260 restarting the scheduler.
12262 Defaults to @samp{30}.
12265 @deftypevr {@code{cups-configuration} parameter} string rip-cache
12266 Specifies the maximum amount of memory to use when converting documents
12267 into bitmaps for a printer.
12269 Defaults to @samp{"128m"}.
12272 @deftypevr {@code{cups-configuration} parameter} string server-admin
12273 Specifies the email address of the server administrator.
12275 Defaults to @samp{"root@@localhost.localdomain"}.
12278 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
12279 The ServerAlias directive is used for HTTP Host header validation when
12280 clients connect to the scheduler from external interfaces. Using the
12281 special name @code{*} can expose your system to known browser-based DNS
12282 rebinding attacks, even when accessing sites through a firewall. If the
12283 auto-discovery of alternate names does not work, we recommend listing
12284 each alternate name with a ServerAlias directive instead of using
12287 Defaults to @samp{*}.
12290 @deftypevr {@code{cups-configuration} parameter} string server-name
12291 Specifies the fully-qualified host name of the server.
12293 Defaults to @samp{"localhost"}.
12296 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
12297 Specifies what information is included in the Server header of HTTP
12298 responses. @code{None} disables the Server header. @code{ProductOnly}
12299 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
12300 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
12301 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
12302 the output of the @code{uname} command. @code{Full} reports @code{CUPS
12303 2.0.0 (@var{uname}) IPP/2.0}.
12305 Defaults to @samp{Minimal}.
12308 @deftypevr {@code{cups-configuration} parameter} string set-env
12309 Set the specified environment variable to be passed to child processes.
12311 Defaults to @samp{"variable value"}.
12314 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
12315 Listens on the specified interfaces for encrypted connections. Valid
12316 values are of the form @var{address}:@var{port}, where @var{address} is
12317 either an IPv6 address enclosed in brackets, an IPv4 address, or
12318 @code{*} to indicate all addresses.
12320 Defaults to @samp{()}.
12323 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
12324 Sets encryption options. By default, CUPS only supports encryption
12325 using TLS v1.0 or higher using known secure cipher suites. The
12326 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
12327 required for some older clients that do not implement newer ones. The
12328 @code{AllowSSL3} option enables SSL v3.0, which is required for some
12329 older clients that do not support TLS v1.0.
12331 Defaults to @samp{()}.
12334 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
12335 Specifies whether the scheduler requires clients to strictly adhere to
12336 the IPP specifications.
12338 Defaults to @samp{#f}.
12341 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
12342 Specifies the HTTP request timeout, in seconds.
12344 Defaults to @samp{300}.
12348 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
12349 Specifies whether the web interface is enabled.
12351 Defaults to @samp{#f}.
12354 At this point you're probably thinking ``oh dear, Guix manual, I like
12355 you but you can stop already with the configuration options''. Indeed.
12356 However, one more point: it could be that you have an existing
12357 @code{cupsd.conf} that you want to use. In that case, you can pass an
12358 @code{opaque-cups-configuration} as the configuration of a
12359 @code{cups-service-type}.
12361 Available @code{opaque-cups-configuration} fields are:
12363 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
12367 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
12368 The contents of the @code{cupsd.conf}, as a string.
12371 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
12372 The contents of the @code{cups-files.conf} file, as a string.
12375 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
12376 strings of the same name, you could instantiate a CUPS service like
12380 (service cups-service-type
12381 (opaque-cups-configuration
12382 (cupsd.conf cupsd.conf)
12383 (cups-files.conf cups-files.conf)))
12387 @node Desktop Services
12388 @subsubsection Desktop Services
12390 The @code{(gnu services desktop)} module provides services that are
12391 usually useful in the context of a ``desktop'' setup---that is, on a
12392 machine running a graphical display server, possibly with graphical user
12393 interfaces, etc. It also defines services that provide specific desktop
12394 environments like GNOME, XFCE or MATE.
12396 To simplify things, the module defines a variable containing the set of
12397 services that users typically expect on a machine with a graphical
12398 environment and networking:
12400 @defvr {Scheme Variable} %desktop-services
12401 This is a list of services that builds upon @var{%base-services} and
12402 adds or adjusts services for a typical ``desktop'' setup.
12404 In particular, it adds a graphical login manager (@pxref{X Window,
12405 @code{slim-service}}), screen lockers, a network management tool
12406 (@pxref{Networking Services, @code{network-manager-service-type}}), energy and color
12407 management services, the @code{elogind} login and seat manager, the
12408 Polkit privilege service, the GeoClue location service, the
12409 AccountsService daemon that allows authorized users change system
12410 passwords, an NTP client (@pxref{Networking Services}), the Avahi
12411 daemon, and has the name service switch service configured to be able to
12412 use @code{nss-mdns} (@pxref{Name Service Switch, mDNS}).
12415 The @var{%desktop-services} variable can be used as the @code{services}
12416 field of an @code{operating-system} declaration (@pxref{operating-system
12417 Reference, @code{services}}).
12419 Additionally, the @code{gnome-desktop-service},
12420 @code{xfce-desktop-service} and @code{mate-desktop-service}
12421 procedures can add GNOME, XFCE and/or MATE to a system.
12422 To ``add GNOME'' means that system-level services like the
12423 backlight adjustment helpers and the power management utilities are
12424 added to the system, extending @code{polkit} and @code{dbus}
12425 appropriately, allowing GNOME to operate with elevated privileges on a
12426 limited number of special-purpose system interfaces. Additionally,
12427 adding a service made by @code{gnome-desktop-service} adds the GNOME
12428 metapackage to the system profile. Likewise, adding the XFCE service
12429 not only adds the @code{xfce} metapackage to the system profile, but it
12430 also gives the Thunar file manager the ability to open a ``root-mode''
12431 file management window, if the user authenticates using the
12432 administrator's password via the standard polkit graphical interface.
12433 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
12434 appropriately, allowing MATE to operate with elevated privileges on a
12435 limited number of special-purpose system interfaces. Additionally,
12436 adding a service made by @code{mate-desktop-service} adds the MATE
12437 metapackage to the system profile.
12439 The desktop environments in Guix use the Xorg display server by
12440 default. If you'd like to use the newer display server protocol
12441 called Wayland, you need to use the @code{sddm-service} instead of the
12442 @code{slim-service} for the graphical login manager. You should then
12443 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
12444 also try starting GNOME on Wayland manually from a TTY with the
12445 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
12446 gnome-session``. Currently only GNOME has support for Wayland.
12448 @deffn {Scheme Procedure} gnome-desktop-service
12449 Return a service that adds the @code{gnome} package to the system
12450 profile, and extends polkit with the actions from
12451 @code{gnome-settings-daemon}.
12454 @deffn {Scheme Procedure} xfce-desktop-service
12455 Return a service that adds the @code{xfce} package to the system profile,
12456 and extends polkit with the ability for @code{thunar} to manipulate the
12457 file system as root from within a user session, after the user has
12458 authenticated with the administrator's password.
12461 @deffn {Scheme Procedure} mate-desktop-service
12462 Return a service that adds the @code{mate} package to the system
12463 profile, and extends polkit with the actions from
12464 @code{mate-settings-daemon}.
12467 Because the GNOME, XFCE and MATE desktop services pull in so many packages,
12468 the default @code{%desktop-services} variable doesn't include either of
12469 them by default. To add GNOME, XFCE or MATE, just @code{cons} them onto
12470 @code{%desktop-services} in the @code{services} field of your
12471 @code{operating-system}:
12474 (use-modules (gnu))
12475 (use-service-modules desktop)
12478 ;; cons* adds items to the list given as its last argument.
12479 (services (cons* (gnome-desktop-service)
12480 (xfce-desktop-service)
12481 %desktop-services))
12485 These desktop environments will then be available as options in the
12486 graphical login window.
12488 The actual service definitions included in @code{%desktop-services} and
12489 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
12490 are described below.
12492 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
12493 Return a service that runs the ``system bus'', using @var{dbus}, with
12494 support for @var{services}.
12496 @uref{http://dbus.freedesktop.org/, D-Bus} is an inter-process communication
12497 facility. Its system bus is used to allow system services to communicate
12498 and to be notified of system-wide events.
12500 @var{services} must be a list of packages that provide an
12501 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
12502 and policy files. For example, to allow avahi-daemon to use the system bus,
12503 @var{services} must be equal to @code{(list avahi)}.
12506 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
12507 Return a service that runs the @code{elogind} login and
12508 seat management daemon. @uref{https://github.com/elogind/elogind,
12509 Elogind} exposes a D-Bus interface that can be used to know which users
12510 are logged in, know what kind of sessions they have open, suspend the
12511 system, inhibit system suspend, reboot the system, and other tasks.
12513 Elogind handles most system-level power events for a computer, for
12514 example suspending the system when a lid is closed, or shutting it down
12515 when the power button is pressed.
12517 The @var{config} keyword argument specifies the configuration for
12518 elogind, and should be the result of an @code{(elogind-configuration
12519 (@var{parameter} @var{value})...)} invocation. Available parameters and
12520 their default values are:
12523 @item kill-user-processes?
12525 @item kill-only-users
12527 @item kill-exclude-users
12529 @item inhibit-delay-max-seconds
12531 @item handle-power-key
12533 @item handle-suspend-key
12535 @item handle-hibernate-key
12537 @item handle-lid-switch
12539 @item handle-lid-switch-docked
12541 @item power-key-ignore-inhibited?
12543 @item suspend-key-ignore-inhibited?
12545 @item hibernate-key-ignore-inhibited?
12547 @item lid-switch-ignore-inhibited?
12549 @item holdoff-timeout-seconds
12553 @item idle-action-seconds
12555 @item runtime-directory-size-percent
12557 @item runtime-directory-size
12561 @item suspend-state
12562 @code{("mem" "standby" "freeze")}
12565 @item hibernate-state
12567 @item hibernate-mode
12568 @code{("platform" "shutdown")}
12569 @item hybrid-sleep-state
12571 @item hybrid-sleep-mode
12572 @code{("suspend" "platform" "shutdown")}
12576 @deffn {Scheme Procedure} accountsservice-service @
12577 [#:accountsservice @var{accountsservice}]
12578 Return a service that runs AccountsService, a system service that can
12579 list available accounts, change their passwords, and so on.
12580 AccountsService integrates with PolicyKit to enable unprivileged users
12581 to acquire the capability to modify their system configuration.
12582 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
12583 accountsservice web site} for more information.
12585 The @var{accountsservice} keyword argument is the @code{accountsservice}
12586 package to expose as a service.
12589 @deffn {Scheme Procedure} polkit-service @
12590 [#:polkit @var{polkit}]
12591 Return a service that runs the
12592 @uref{http://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
12593 management service}, which allows system administrators to grant access to
12594 privileged operations in a structured way. By querying the Polkit service, a
12595 privileged system component can know when it should grant additional
12596 capabilities to ordinary users. For example, an ordinary user can be granted
12597 the capability to suspend the system if the user is logged in locally.
12600 @deffn {Scheme Procedure} upower-service [#:upower @var{upower}] @
12601 [#:watts-up-pro? #f] @
12602 [#:poll-batteries? #t] @
12603 [#:ignore-lid? #f] @
12604 [#:use-percentage-for-policy? #f] @
12605 [#:percentage-low 10] @
12606 [#:percentage-critical 3] @
12607 [#:percentage-action 2] @
12608 [#:time-low 1200] @
12609 [#:time-critical 300] @
12610 [#:time-action 120] @
12611 [#:critical-power-action 'hybrid-sleep]
12612 Return a service that runs @uref{http://upower.freedesktop.org/,
12613 @command{upowerd}}, a system-wide monitor for power consumption and battery
12614 levels, with the given configuration settings. It implements the
12615 @code{org.freedesktop.UPower} D-Bus interface, and is notably used by
12619 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
12620 Return a service for @uref{http://udisks.freedesktop.org/docs/latest/,
12621 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
12622 notifications and ways to mount/unmount disks. Programs that talk to UDisks
12623 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
12626 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
12627 Return a service that runs @command{colord}, a system service with a D-Bus
12628 interface to manage the color profiles of input and output devices such as
12629 screens and scanners. It is notably used by the GNOME Color Manager graphical
12630 tool. See @uref{http://www.freedesktop.org/software/colord/, the colord web
12631 site} for more information.
12634 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
12635 Return a configuration allowing an application to access GeoClue
12636 location data. @var{name} is the Desktop ID of the application, without
12637 the @code{.desktop} part. If @var{allowed?} is true, the application
12638 will have access to location information by default. The boolean
12639 @var{system?} value indicates whether an application is a system component
12640 or not. Finally @var{users} is a list of UIDs of all users for which
12641 this application is allowed location info access. An empty users list
12642 means that all users are allowed.
12645 @defvr {Scheme Variable} %standard-geoclue-applications
12646 The standard list of well-known GeoClue application configurations,
12647 granting authority to the GNOME date-and-time utility to ask for the
12648 current location in order to set the time zone, and allowing the
12649 IceCat and Epiphany web browsers to request location information.
12650 IceCat and Epiphany both query the user before allowing a web page to
12651 know the user's location.
12654 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
12655 [#:whitelist '()] @
12656 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
12657 [#:submit-data? #f]
12658 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
12659 [#:submission-nick "geoclue"] @
12660 [#:applications %standard-geoclue-applications]
12661 Return a service that runs the GeoClue location service. This service
12662 provides a D-Bus interface to allow applications to request access to a
12663 user's physical location, and optionally to add information to online
12664 location databases. See
12665 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
12666 web site} for more information.
12669 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
12670 [@w{#:auto-enable? #f}]
12671 Return a service that runs the @command{bluetoothd} daemon, which
12672 manages all the Bluetooth devices and provides a number of D-Bus
12673 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
12674 powered automatically at boot, which can be useful when using a
12675 bluetooth keyboard or mouse.
12677 Users need to be in the @code{lp} group to access the D-Bus service.
12680 @node Database Services
12681 @subsubsection Database Services
12685 The @code{(gnu services databases)} module provides the following services.
12687 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
12688 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
12689 [#:port 5432] [#:locale ``en_US.utf8'']
12690 Return a service that runs @var{postgresql}, the PostgreSQL database
12693 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
12694 creates a database cluster with @var{locale} as the default
12695 locale, stored in @var{data-directory}. It then listens on @var{port}.
12698 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
12699 Return a service that runs @command{mysqld}, the MySQL or MariaDB
12702 The optional @var{config} argument specifies the configuration for
12703 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
12706 @deftp {Data Type} mysql-configuration
12707 Data type representing the configuration of @var{mysql-service}.
12710 @item @code{mysql} (default: @var{mariadb})
12711 Package object of the MySQL database server, can be either @var{mariadb}
12714 For MySQL, a temporary root password will be displayed at activation time.
12715 For MariaDB, the root password is empty.
12717 @item @code{port} (default: @code{3306})
12718 TCP port on which the database server listens for incoming connections.
12722 @defvr {Scheme Variable} memcached-service-type
12723 This is the service type for the @uref{https://memcached.org/,
12724 Memcached} service, which provides a distributed in memory cache. The
12725 value for the service type is a @code{memcached-configuration} object.
12729 (service memcached-service-type)
12732 @deftp {Data Type} memcached-configuration
12733 Data type representing the configuration of memcached.
12736 @item @code{memcached} (default: @code{memcached})
12737 The Memcached package to use.
12739 @item @code{interfaces} (default: @code{'("0.0.0.0")})
12740 Network interfaces on which to listen.
12742 @item @code{tcp-port} (default: @code{11211})
12743 Port on which to accept connections on,
12745 @item @code{udp-port} (default: @code{11211})
12746 Port on which to accept UDP connections on, a value of 0 will disable
12747 listening on a UDP socket.
12749 @item @code{additional-options} (default: @code{'()})
12750 Additional command line options to pass to @code{memcached}.
12754 @defvr {Scheme Variable} mongodb-service-type
12755 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
12756 The value for the service type is a @code{mongodb-configuration} object.
12760 (service mongodb-service-type)
12763 @deftp {Data Type} mongodb-configuration
12764 Data type representing the configuration of mongodb.
12767 @item @code{mongodb} (default: @code{mongodb})
12768 The MongoDB package to use.
12770 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
12771 The configuration file for MongoDB.
12773 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
12774 This value is used to create the directory, so that it exists and is
12775 owned by the mongodb user. It should match the data-directory which
12776 MongoDB is configured to use through the configuration file.
12780 @defvr {Scheme Variable} redis-service-type
12781 This is the service type for the @uref{https://redis.io/, Redis}
12782 key/value store, whose value is a @code{redis-configuration} object.
12785 @deftp {Data Type} redis-configuration
12786 Data type representing the configuration of redis.
12789 @item @code{redis} (default: @code{redis})
12790 The Redis package to use.
12792 @item @code{bind} (default: @code{"127.0.0.1"})
12793 Network interface on which to listen.
12795 @item @code{port} (default: @code{6379})
12796 Port on which to accept connections on, a value of 0 will disable
12797 listening on a TCP socket.
12799 @item @code{working-directory} (default: @code{"/var/lib/redis"})
12800 Directory in which to store the database and related files.
12804 @node Mail Services
12805 @subsubsection Mail Services
12809 The @code{(gnu services mail)} module provides Guix service definitions
12810 for email services: IMAP, POP3, and LMTP servers, as well as mail
12811 transport agents (MTAs). Lots of acronyms! These services are detailed
12812 in the subsections below.
12814 @subsubheading Dovecot Service
12816 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
12817 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
12820 By default, Dovecot does not need much configuration; the default
12821 configuration object created by @code{(dovecot-configuration)} will
12822 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
12823 certificate will be generated for TLS-protected connections, though
12824 Dovecot will also listen on cleartext ports by default. There are a
12825 number of options, though, which mail administrators might need to change,
12826 and as is the case with other services, Guix allows the system
12827 administrator to specify these parameters via a uniform Scheme interface.
12829 For example, to specify that mail is located at @code{maildir~/.mail},
12830 one would instantiate the Dovecot service like this:
12833 (dovecot-service #:config
12834 (dovecot-configuration
12835 (mail-location "maildir:~/.mail")))
12838 The available configuration parameters follow. Each parameter
12839 definition is preceded by its type; for example, @samp{string-list foo}
12840 indicates that the @code{foo} parameter should be specified as a list of
12841 strings. There is also a way to specify the configuration as a string,
12842 if you have an old @code{dovecot.conf} file that you want to port over
12843 from some other system; see the end for more details.
12845 @c The following documentation was initially generated by
12846 @c (generate-documentation) in (gnu services mail). Manually maintained
12847 @c documentation is better, so we shouldn't hesitate to edit below as
12848 @c needed. However if the change you want to make to this documentation
12849 @c can be done in an automated way, it's probably easier to change
12850 @c (generate-documentation) than to make it below and have to deal with
12851 @c the churn as dovecot updates.
12853 Available @code{dovecot-configuration} fields are:
12855 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
12856 The dovecot package.
12859 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
12860 A list of IPs or hosts where to listen for connections. @samp{*}
12861 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
12862 interfaces. If you want to specify non-default ports or anything more
12863 complex, customize the address and port fields of the
12864 @samp{inet-listener} of the specific services you are interested in.
12867 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
12868 List of protocols we want to serve. Available protocols include
12869 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
12871 Available @code{protocol-configuration} fields are:
12873 @deftypevr {@code{protocol-configuration} parameter} string name
12874 The name of the protocol.
12877 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
12878 UNIX socket path to the master authentication server to find users.
12879 This is used by imap (for shared users) and lda.
12880 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
12883 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
12884 Space separated list of plugins to load.
12887 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
12888 Maximum number of IMAP connections allowed for a user from each IP
12889 address. NOTE: The username is compared case-sensitively.
12890 Defaults to @samp{10}.
12895 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
12896 List of services to enable. Available services include @samp{imap},
12897 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
12900 Available @code{service-configuration} fields are:
12902 @deftypevr {@code{service-configuration} parameter} string kind
12903 The service kind. Valid values include @code{director},
12904 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
12905 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
12906 @code{tcpwrap}, @code{quota-warning}, or anything else.
12909 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
12910 Listeners for the service. A listener is either a
12911 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
12912 an @code{inet-listener-configuration}.
12913 Defaults to @samp{()}.
12915 Available @code{unix-listener-configuration} fields are:
12917 @deftypevr {@code{unix-listener-configuration} parameter} string path
12918 Path to the file, relative to @code{base-dir} field. This is also used as
12922 @deftypevr {@code{unix-listener-configuration} parameter} string mode
12923 The access mode for the socket.
12924 Defaults to @samp{"0600"}.
12927 @deftypevr {@code{unix-listener-configuration} parameter} string user
12928 The user to own the socket.
12929 Defaults to @samp{""}.
12932 @deftypevr {@code{unix-listener-configuration} parameter} string group
12933 The group to own the socket.
12934 Defaults to @samp{""}.
12938 Available @code{fifo-listener-configuration} fields are:
12940 @deftypevr {@code{fifo-listener-configuration} parameter} string path
12941 Path to the file, relative to @code{base-dir} field. This is also used as
12945 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
12946 The access mode for the socket.
12947 Defaults to @samp{"0600"}.
12950 @deftypevr {@code{fifo-listener-configuration} parameter} string user
12951 The user to own the socket.
12952 Defaults to @samp{""}.
12955 @deftypevr {@code{fifo-listener-configuration} parameter} string group
12956 The group to own the socket.
12957 Defaults to @samp{""}.
12961 Available @code{inet-listener-configuration} fields are:
12963 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
12964 The protocol to listen for.
12967 @deftypevr {@code{inet-listener-configuration} parameter} string address
12968 The address on which to listen, or empty for all addresses.
12969 Defaults to @samp{""}.
12972 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
12973 The port on which to listen.
12976 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
12977 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
12979 Defaults to @samp{#t}.
12984 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
12985 Number of connections to handle before starting a new process.
12986 Typically the only useful values are 0 (unlimited) or 1. 1 is more
12987 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
12988 Defaults to @samp{1}.
12991 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
12992 Number of processes to always keep waiting for more connections.
12993 Defaults to @samp{0}.
12996 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
12997 If you set @samp{service-count 0}, you probably need to grow
12999 Defaults to @samp{256000000}.
13004 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
13005 Dict configuration, as created by the @code{dict-configuration}
13008 Available @code{dict-configuration} fields are:
13010 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
13011 A list of key-value pairs that this dict should hold.
13012 Defaults to @samp{()}.
13017 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
13018 A list of passdb configurations, each one created by the
13019 @code{passdb-configuration} constructor.
13021 Available @code{passdb-configuration} fields are:
13023 @deftypevr {@code{passdb-configuration} parameter} string driver
13024 The driver that the passdb should use. Valid values include
13025 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
13027 Defaults to @samp{"pam"}.
13030 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
13031 Space separated list of arguments to the passdb driver.
13032 Defaults to @samp{""}.
13037 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
13038 List of userdb configurations, each one created by the
13039 @code{userdb-configuration} constructor.
13041 Available @code{userdb-configuration} fields are:
13043 @deftypevr {@code{userdb-configuration} parameter} string driver
13044 The driver that the userdb should use. Valid values include
13045 @samp{passwd} and @samp{static}.
13046 Defaults to @samp{"passwd"}.
13049 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
13050 Space separated list of arguments to the userdb driver.
13051 Defaults to @samp{""}.
13054 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
13055 Override fields from passwd.
13056 Defaults to @samp{()}.
13061 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
13062 Plug-in configuration, created by the @code{plugin-configuration}
13066 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
13067 List of namespaces. Each item in the list is created by the
13068 @code{namespace-configuration} constructor.
13070 Available @code{namespace-configuration} fields are:
13072 @deftypevr {@code{namespace-configuration} parameter} string name
13073 Name for this namespace.
13076 @deftypevr {@code{namespace-configuration} parameter} string type
13077 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
13078 Defaults to @samp{"private"}.
13081 @deftypevr {@code{namespace-configuration} parameter} string separator
13082 Hierarchy separator to use. You should use the same separator for
13083 all namespaces or some clients get confused. @samp{/} is usually a good
13084 one. The default however depends on the underlying mail storage
13086 Defaults to @samp{""}.
13089 @deftypevr {@code{namespace-configuration} parameter} string prefix
13090 Prefix required to access this namespace. This needs to be
13091 different for all namespaces. For example @samp{Public/}.
13092 Defaults to @samp{""}.
13095 @deftypevr {@code{namespace-configuration} parameter} string location
13096 Physical location of the mailbox. This is in the same format as
13097 mail_location, which is also the default for it.
13098 Defaults to @samp{""}.
13101 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
13102 There can be only one INBOX, and this setting defines which
13104 Defaults to @samp{#f}.
13107 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
13108 If namespace is hidden, it's not advertised to clients via NAMESPACE
13109 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
13110 useful when converting from another server with different namespaces
13111 which you want to deprecate but still keep working. For example you can
13112 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
13114 Defaults to @samp{#f}.
13117 @deftypevr {@code{namespace-configuration} parameter} boolean list?
13118 Show the mailboxes under this namespace with the LIST command. This
13119 makes the namespace visible for clients that do not support the NAMESPACE
13120 extension. The special @code{children} value lists child mailboxes, but
13121 hides the namespace prefix.
13122 Defaults to @samp{#t}.
13125 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
13126 Namespace handles its own subscriptions. If set to @code{#f}, the
13127 parent namespace handles them. The empty prefix should always have this
13129 Defaults to @samp{#t}.
13132 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
13133 List of predefined mailboxes in this namespace.
13134 Defaults to @samp{()}.
13136 Available @code{mailbox-configuration} fields are:
13138 @deftypevr {@code{mailbox-configuration} parameter} string name
13139 Name for this mailbox.
13142 @deftypevr {@code{mailbox-configuration} parameter} string auto
13143 @samp{create} will automatically create this mailbox.
13144 @samp{subscribe} will both create and subscribe to the mailbox.
13145 Defaults to @samp{"no"}.
13148 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
13149 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
13150 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
13151 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
13152 Defaults to @samp{()}.
13159 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
13160 Base directory where to store runtime data.
13161 Defaults to @samp{"/var/run/dovecot/"}.
13164 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
13165 Greeting message for clients.
13166 Defaults to @samp{"Dovecot ready."}.
13169 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
13170 List of trusted network ranges. Connections from these IPs are
13171 allowed to override their IP addresses and ports (for logging and for
13172 authentication checks). @samp{disable-plaintext-auth} is also ignored
13173 for these networks. Typically you would specify your IMAP proxy servers
13175 Defaults to @samp{()}.
13178 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
13179 List of login access check sockets (e.g. tcpwrap).
13180 Defaults to @samp{()}.
13183 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
13184 Show more verbose process titles (in ps). Currently shows user name
13185 and IP address. Useful for seeing who is actually using the IMAP
13186 processes (e.g. shared mailboxes or if the same uid is used for multiple
13188 Defaults to @samp{#f}.
13191 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
13192 Should all processes be killed when Dovecot master process shuts down.
13193 Setting this to @code{#f} means that Dovecot can be upgraded without
13194 forcing existing client connections to close (although that could also
13195 be a problem if the upgrade is e.g. due to a security fix).
13196 Defaults to @samp{#t}.
13199 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
13200 If non-zero, run mail commands via this many connections to doveadm
13201 server, instead of running them directly in the same process.
13202 Defaults to @samp{0}.
13205 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
13206 UNIX socket or host:port used for connecting to doveadm server.
13207 Defaults to @samp{"doveadm-server"}.
13210 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
13211 List of environment variables that are preserved on Dovecot startup
13212 and passed down to all of its child processes. You can also give
13213 key=value pairs to always set specific settings.
13216 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
13217 Disable LOGIN command and all other plaintext authentications unless
13218 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
13219 matches the local IP (i.e. you're connecting from the same computer),
13220 the connection is considered secure and plaintext authentication is
13221 allowed. See also ssl=required setting.
13222 Defaults to @samp{#t}.
13225 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
13226 Authentication cache size (e.g. @samp{#e10e6}). 0 means it's disabled.
13227 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
13228 for caching to be used.
13229 Defaults to @samp{0}.
13232 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
13233 Time to live for cached data. After TTL expires the cached record
13234 is no longer used, *except* if the main database lookup returns internal
13235 failure. We also try to handle password changes automatically: If
13236 user's previous authentication was successful, but this one wasn't, the
13237 cache isn't used. For now this works only with plaintext
13239 Defaults to @samp{"1 hour"}.
13242 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
13243 TTL for negative hits (user not found, password mismatch).
13244 0 disables caching them completely.
13245 Defaults to @samp{"1 hour"}.
13248 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
13249 List of realms for SASL authentication mechanisms that need them.
13250 You can leave it empty if you don't want to support multiple realms.
13251 Many clients simply use the first one listed here, so keep the default
13253 Defaults to @samp{()}.
13256 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
13257 Default realm/domain to use if none was specified. This is used for
13258 both SASL realms and appending @@domain to username in plaintext
13260 Defaults to @samp{""}.
13263 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
13264 List of allowed characters in username. If the user-given username
13265 contains a character not listed in here, the login automatically fails.
13266 This is just an extra check to make sure user can't exploit any
13267 potential quote escaping vulnerabilities with SQL/LDAP databases. If
13268 you want to allow all characters, set this value to empty.
13269 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
13272 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
13273 Username character translations before it's looked up from
13274 databases. The value contains series of from -> to characters. For
13275 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
13276 translated to @samp{@@}.
13277 Defaults to @samp{""}.
13280 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
13281 Username formatting before it's looked up from databases. You can
13282 use the standard variables here, e.g. %Lu would lowercase the username,
13283 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
13284 change the @samp{@@} into @samp{-AT-}. This translation is done after
13285 @samp{auth-username-translation} changes.
13286 Defaults to @samp{"%Lu"}.
13289 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
13290 If you want to allow master users to log in by specifying the master
13291 username within the normal username string (i.e. not using SASL
13292 mechanism's support for it), you can specify the separator character
13293 here. The format is then <username><separator><master username>.
13294 UW-IMAP uses @samp{*} as the separator, so that could be a good
13296 Defaults to @samp{""}.
13299 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
13300 Username to use for users logging in with ANONYMOUS SASL
13302 Defaults to @samp{"anonymous"}.
13305 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
13306 Maximum number of dovecot-auth worker processes. They're used to
13307 execute blocking passdb and userdb queries (e.g. MySQL and PAM).
13308 They're automatically created and destroyed as needed.
13309 Defaults to @samp{30}.
13312 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
13313 Host name to use in GSSAPI principal names. The default is to use
13314 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
13315 allow all keytab entries.
13316 Defaults to @samp{""}.
13319 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
13320 Kerberos keytab to use for the GSSAPI mechanism. Will use the
13321 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
13322 need to change the auth service to run as root to be able to read this
13324 Defaults to @samp{""}.
13327 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
13328 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
13329 and @samp{ntlm-auth} helper.
13330 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
13331 Defaults to @samp{#f}.
13334 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
13335 Path for Samba's @samp{ntlm-auth} helper binary.
13336 Defaults to @samp{"/usr/bin/ntlm_auth"}.
13339 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
13340 Time to delay before replying to failed authentications.
13341 Defaults to @samp{"2 secs"}.
13344 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
13345 Require a valid SSL client certificate or the authentication
13347 Defaults to @samp{#f}.
13350 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
13351 Take the username from client's SSL certificate, using
13352 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
13354 Defaults to @samp{#f}.
13357 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
13358 List of wanted authentication mechanisms. Supported mechanisms are:
13359 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
13360 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
13361 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
13362 @samp{disable-plaintext-auth} setting.
13365 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
13366 List of IPs or hostnames to all director servers, including ourself.
13367 Ports can be specified as ip:port. The default port is the same as what
13368 director service's @samp{inet-listener} is using.
13369 Defaults to @samp{()}.
13372 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
13373 List of IPs or hostnames to all backend mail servers. Ranges are
13374 allowed too, like 10.0.0.10-10.0.0.30.
13375 Defaults to @samp{()}.
13378 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
13379 How long to redirect users to a specific server after it no longer
13380 has any connections.
13381 Defaults to @samp{"15 min"}.
13384 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
13385 How the username is translated before being hashed. Useful values
13386 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
13387 are shared within domain.
13388 Defaults to @samp{"%Lu"}.
13391 @deftypevr {@code{dovecot-configuration} parameter} string log-path
13392 Log file to use for error messages. @samp{syslog} logs to syslog,
13393 @samp{/dev/stderr} logs to stderr.
13394 Defaults to @samp{"syslog"}.
13397 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
13398 Log file to use for informational messages. Defaults to
13400 Defaults to @samp{""}.
13403 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
13404 Log file to use for debug messages. Defaults to
13405 @samp{info-log-path}.
13406 Defaults to @samp{""}.
13409 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
13410 Syslog facility to use if you're logging to syslog. Usually if you
13411 don't want to use @samp{mail}, you'll use local0..local7. Also other
13412 standard facilities are supported.
13413 Defaults to @samp{"mail"}.
13416 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
13417 Log unsuccessful authentication attempts and the reasons why they
13419 Defaults to @samp{#f}.
13422 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose-passwords?
13423 In case of password mismatches, log the attempted password. Valid
13424 values are no, plain and sha1. sha1 can be useful for detecting brute
13425 force password attempts vs. user simply trying the same password over
13426 and over again. You can also truncate the value to n chars by appending
13427 ":n" (e.g. sha1:6).
13428 Defaults to @samp{#f}.
13431 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
13432 Even more verbose logging for debugging purposes. Shows for example
13434 Defaults to @samp{#f}.
13437 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
13438 In case of password mismatches, log the passwords and used scheme so
13439 the problem can be debugged. Enabling this also enables
13441 Defaults to @samp{#f}.
13444 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
13445 Enable mail process debugging. This can help you figure out why
13446 Dovecot isn't finding your mails.
13447 Defaults to @samp{#f}.
13450 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
13451 Show protocol level SSL errors.
13452 Defaults to @samp{#f}.
13455 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
13456 Prefix for each line written to log file. % codes are in
13457 strftime(3) format.
13458 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
13461 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
13462 List of elements we want to log. The elements which have a
13463 non-empty variable value are joined together to form a comma-separated
13467 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
13468 Login log format. %s contains @samp{login-log-format-elements}
13469 string, %$ contains the data we want to log.
13470 Defaults to @samp{"%$: %s"}.
13473 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
13474 Log prefix for mail processes. See doc/wiki/Variables.txt for list
13475 of possible variables you can use.
13476 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
13479 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
13480 Format to use for logging mail deliveries. You can use variables:
13483 Delivery status message (e.g. @samp{saved to INBOX})
13495 Defaults to @samp{"msgid=%m: %$"}.
13498 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
13499 Location for users' mailboxes. The default is empty, which means
13500 that Dovecot tries to find the mailboxes automatically. This won't work
13501 if the user doesn't yet have any mail, so you should explicitly tell
13502 Dovecot the full location.
13504 If you're using mbox, giving a path to the INBOX
13505 file (e.g. /var/mail/%u) isn't enough. You'll also need to tell Dovecot
13506 where the other mailboxes are kept. This is called the "root mail
13507 directory", and it must be the first path given in the
13508 @samp{mail-location} setting.
13510 There are a few special variables you can use, eg.:
13516 user part in user@@domain, same as %u if there's no domain
13518 domain part in user@@domain, empty if there's no domain
13523 See doc/wiki/Variables.txt for full list. Some examples:
13525 @item maildir:~/Maildir
13526 @item mbox:~/mail:INBOX=/var/mail/%u
13527 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
13529 Defaults to @samp{""}.
13532 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
13533 System user and group used to access mails. If you use multiple,
13534 userdb can override these by returning uid or gid fields. You can use
13535 either numbers or names. <doc/wiki/UserIds.txt>.
13536 Defaults to @samp{""}.
13539 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
13541 Defaults to @samp{""}.
13544 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
13545 Group to enable temporarily for privileged operations. Currently
13546 this is used only with INBOX when either its initial creation or
13547 dotlocking fails. Typically this is set to "mail" to give access to
13549 Defaults to @samp{""}.
13552 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
13553 Grant access to these supplementary groups for mail processes.
13554 Typically these are used to set up access to shared mailboxes. Note
13555 that it may be dangerous to set these if users can create
13556 symlinks (e.g. if "mail" group is set here, ln -s /var/mail ~/mail/var
13557 could allow a user to delete others' mailboxes, or ln -s
13558 /secret/shared/box ~/mail/mybox would allow reading it).
13559 Defaults to @samp{""}.
13562 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
13563 Allow full file system access to clients. There's no access checks
13564 other than what the operating system does for the active UID/GID. It
13565 works with both maildir and mboxes, allowing you to prefix mailboxes
13566 names with e.g. /path/ or ~user/.
13567 Defaults to @samp{#f}.
13570 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
13571 Don't use mmap() at all. This is required if you store indexes to
13572 shared file systems (NFS or clustered file system).
13573 Defaults to @samp{#f}.
13576 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
13577 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
13578 supports @samp{O_EXCL} since version 3, so this should be safe to use
13579 nowadays by default.
13580 Defaults to @samp{#t}.
13583 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
13584 When to use fsync() or fdatasync() calls:
13587 Whenever necessary to avoid losing important data
13589 Useful with e.g. NFS when write()s are delayed
13591 Never use it (best performance, but crashes can lose data).
13593 Defaults to @samp{"optimized"}.
13596 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
13597 Mail storage exists in NFS. Set this to yes to make Dovecot flush
13598 NFS caches whenever needed. If you're using only a single mail server
13600 Defaults to @samp{#f}.
13603 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
13604 Mail index files also exist in NFS. Setting this to yes requires
13605 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
13606 Defaults to @samp{#f}.
13609 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
13610 Locking method for index files. Alternatives are fcntl, flock and
13611 dotlock. Dotlocking uses some tricks which may create more disk I/O
13612 than other locking methods. NFS users: flock doesn't work, remember to
13613 change @samp{mmap-disable}.
13614 Defaults to @samp{"fcntl"}.
13617 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
13618 Directory in which LDA/LMTP temporarily stores incoming mails >128
13620 Defaults to @samp{"/tmp"}.
13623 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
13624 Valid UID range for users. This is mostly to make sure that users can't
13625 log in as daemons or other system users. Note that denying root logins is
13626 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
13628 Defaults to @samp{500}.
13631 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
13633 Defaults to @samp{0}.
13636 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
13637 Valid GID range for users. Users having non-valid GID as primary group ID
13638 aren't allowed to log in. If user belongs to supplementary groups with
13639 non-valid GIDs, those groups are not set.
13640 Defaults to @samp{1}.
13643 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
13645 Defaults to @samp{0}.
13648 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
13649 Maximum allowed length for mail keyword name. It's only forced when
13650 trying to create new keywords.
13651 Defaults to @samp{50}.
13654 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
13655 List of directories under which chrooting is allowed for mail
13656 processes (i.e. /var/mail will allow chrooting to /var/mail/foo/bar
13657 too). This setting doesn't affect @samp{login-chroot}
13658 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
13659 "/./" in home dirs are ignored. WARNING: Never add directories here
13660 which local users can modify, that may lead to root exploit. Usually
13661 this should be done only if you don't allow shell access for users.
13662 <doc/wiki/Chrooting.txt>.
13663 Defaults to @samp{()}.
13666 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
13667 Default chroot directory for mail processes. This can be overridden
13668 for specific users in user database by giving /./ in user's home
13669 directory (e.g. /home/./user chroots into /home). Note that usually
13670 there is no real need to do chrooting, Dovecot doesn't allow users to
13671 access files outside their mail directory anyway. If your home
13672 directories are prefixed with the chroot directory, append "/." to
13673 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
13674 Defaults to @samp{""}.
13677 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
13678 UNIX socket path to master authentication server to find users.
13679 This is used by imap (for shared users) and lda.
13680 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
13683 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
13684 Directory where to look up mail plugins.
13685 Defaults to @samp{"/usr/lib/dovecot"}.
13688 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
13689 List of plugins to load for all services. Plugins specific to IMAP,
13690 LDA, etc. are added to this list in their own .conf files.
13691 Defaults to @samp{()}.
13694 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
13695 The minimum number of mails in a mailbox before updates are done to
13696 cache file. This allows optimizing Dovecot's behavior to do less disk
13697 writes at the cost of more disk reads.
13698 Defaults to @samp{0}.
13701 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
13702 When IDLE command is running, mailbox is checked once in a while to
13703 see if there are any new mails or other changes. This setting defines
13704 the minimum time to wait between those checks. Dovecot can also use
13705 dnotify, inotify and kqueue to find out immediately when changes
13707 Defaults to @samp{"30 secs"}.
13710 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
13711 Save mails with CR+LF instead of plain LF. This makes sending those
13712 mails take less CPU, especially with sendfile() syscall with Linux and
13713 FreeBSD. But it also creates a bit more disk I/O which may just make it
13714 slower. Also note that if other software reads the mboxes/maildirs,
13715 they may handle the extra CRs wrong and cause problems.
13716 Defaults to @samp{#f}.
13719 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
13720 By default LIST command returns all entries in maildir beginning
13721 with a dot. Enabling this option makes Dovecot return only entries
13722 which are directories. This is done by stat()ing each entry, so it
13723 causes more disk I/O.
13724 (For systems setting struct @samp{dirent->d_type} this check is free
13725 and it's done always regardless of this setting).
13726 Defaults to @samp{#f}.
13729 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
13730 When copying a message, do it with hard links whenever possible.
13731 This makes the performance much better, and it's unlikely to have any
13733 Defaults to @samp{#t}.
13736 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
13737 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
13738 directory only when its mtime changes unexpectedly or when we can't find
13739 the mail otherwise.
13740 Defaults to @samp{#f}.
13743 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
13744 Which locking methods to use for locking mbox. There are four
13749 Create <mailbox>.lock file. This is the oldest and most NFS-safe
13750 solution. If you want to use /var/mail/ like directory, the users will
13751 need write access to that directory.
13753 Same as dotlock, but if it fails because of permissions or because there
13754 isn't enough disk space, just skip it.
13756 Use this if possible. Works with NFS too if lockd is used.
13758 May not exist in all systems. Doesn't work with NFS.
13760 May not exist in all systems. Doesn't work with NFS.
13763 You can use multiple locking methods; if you do the order they're declared
13764 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
13765 locking methods as well. Some operating systems don't allow using some of
13766 them simultaneously.
13769 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
13773 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
13774 Maximum time to wait for lock (all of them) before aborting.
13775 Defaults to @samp{"5 mins"}.
13778 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
13779 If dotlock exists but the mailbox isn't modified in any way,
13780 override the lock file after this much time.
13781 Defaults to @samp{"2 mins"}.
13784 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
13785 When mbox changes unexpectedly we have to fully read it to find out
13786 what changed. If the mbox is large this can take a long time. Since
13787 the change is usually just a newly appended mail, it'd be faster to
13788 simply read the new mails. If this setting is enabled, Dovecot does
13789 this but still safely fallbacks to re-reading the whole mbox file
13790 whenever something in mbox isn't how it's expected to be. The only real
13791 downside to this setting is that if some other MUA changes message
13792 flags, Dovecot doesn't notice it immediately. Note that a full sync is
13793 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
13794 Defaults to @samp{#t}.
13797 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
13798 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
13799 EXAMINE, EXPUNGE or CHECK commands. If this is set,
13800 @samp{mbox-dirty-syncs} is ignored.
13801 Defaults to @samp{#f}.
13804 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
13805 Delay writing mbox headers until doing a full write sync (EXPUNGE
13806 and CHECK commands and when closing the mailbox). This is especially
13807 useful for POP3 where clients often delete all mails. The downside is
13808 that our changes aren't immediately visible to other MUAs.
13809 Defaults to @samp{#t}.
13812 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
13813 If mbox size is smaller than this (e.g. 100k), don't write index
13814 files. If an index file already exists it's still read, just not
13816 Defaults to @samp{0}.
13819 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
13820 Maximum dbox file size until it's rotated.
13821 Defaults to @samp{10000000}.
13824 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
13825 Maximum dbox file age until it's rotated. Typically in days. Day
13826 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
13828 Defaults to @samp{"1d"}.
13831 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
13832 When creating new mdbox files, immediately preallocate their size to
13833 @samp{mdbox-rotate-size}. This setting currently works only in Linux
13834 with some file systems (ext4, xfs).
13835 Defaults to @samp{#f}.
13838 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
13839 sdbox and mdbox support saving mail attachments to external files,
13840 which also allows single instance storage for them. Other backends
13841 don't support this for now.
13843 WARNING: This feature hasn't been tested much yet. Use at your own risk.
13845 Directory root where to store mail attachments. Disabled, if empty.
13846 Defaults to @samp{""}.
13849 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
13850 Attachments smaller than this aren't saved externally. It's also
13851 possible to write a plugin to disable saving specific attachments
13853 Defaults to @samp{128000}.
13856 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
13857 File system backend to use for saving attachments:
13860 No SiS done by Dovecot (but this might help FS's own deduplication)
13862 SiS with immediate byte-by-byte comparison during saving
13863 @item sis-queue posix
13864 SiS with delayed comparison and deduplication.
13866 Defaults to @samp{"sis posix"}.
13869 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
13870 Hash format to use in attachment filenames. You can add any text and
13871 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
13872 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
13873 truncated, e.g. @code{%@{sha256:80@}} returns only first 80 bits.
13874 Defaults to @samp{"%@{sha1@}"}.
13877 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
13879 Defaults to @samp{100}.
13882 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
13884 Defaults to @samp{1000}.
13887 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
13888 Default VSZ (virtual memory size) limit for service processes.
13889 This is mainly intended to catch and kill processes that leak memory
13890 before they eat up everything.
13891 Defaults to @samp{256000000}.
13894 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
13895 Login user is internally used by login processes. This is the most
13896 untrusted user in Dovecot system. It shouldn't have access to anything
13898 Defaults to @samp{"dovenull"}.
13901 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
13902 Internal user is used by unprivileged processes. It should be
13903 separate from login user, so that login processes can't disturb other
13905 Defaults to @samp{"dovecot"}.
13908 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
13909 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
13910 Defaults to @samp{"required"}.
13913 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
13914 PEM encoded X.509 SSL/TLS certificate (public key).
13915 Defaults to @samp{"</etc/dovecot/default.pem"}.
13918 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
13919 PEM encoded SSL/TLS private key. The key is opened before
13920 dropping root privileges, so keep the key file unreadable by anyone but
13922 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
13925 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
13926 If key file is password protected, give the password here.
13927 Alternatively give it when starting dovecot with -p parameter. Since
13928 this file is often world-readable, you may want to place this setting
13929 instead to a different.
13930 Defaults to @samp{""}.
13933 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
13934 PEM encoded trusted certificate authority. Set this only if you
13935 intend to use @samp{ssl-verify-client-cert? #t}. The file should
13936 contain the CA certificate(s) followed by the matching
13937 CRL(s). (e.g. @samp{ssl-ca </etc/ssl/certs/ca.pem}).
13938 Defaults to @samp{""}.
13941 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
13942 Require that CRL check succeeds for client certificates.
13943 Defaults to @samp{#t}.
13946 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
13947 Request client to send a certificate. If you also want to require
13948 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
13949 Defaults to @samp{#f}.
13952 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
13953 Which field from certificate to use for username. commonName and
13954 x500UniqueIdentifier are the usual choices. You'll also need to set
13955 @samp{auth-ssl-username-from-cert? #t}.
13956 Defaults to @samp{"commonName"}.
13959 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
13960 Minimum SSL protocol version to accept.
13961 Defaults to @samp{"TLSv1"}.
13964 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
13965 SSL ciphers to use.
13966 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
13969 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
13970 SSL crypto device to use, for valid values run "openssl engine".
13971 Defaults to @samp{""}.
13974 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
13975 Address to use when sending rejection mails.
13976 %d expands to recipient domain.
13977 Defaults to @samp{"postmaster@@%d"}.
13980 @deftypevr {@code{dovecot-configuration} parameter} string hostname
13981 Hostname to use in various parts of sent mails (e.g. in Message-Id)
13982 and in LMTP replies. Default is the system's real hostname@@domain.
13983 Defaults to @samp{""}.
13986 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
13987 If user is over quota, return with temporary failure instead of
13989 Defaults to @samp{#f}.
13992 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
13993 Binary to use for sending mails.
13994 Defaults to @samp{"/usr/sbin/sendmail"}.
13997 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
13998 If non-empty, send mails via this SMTP host[:port] instead of
14000 Defaults to @samp{""}.
14003 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
14004 Subject: header to use for rejection mails. You can use the same
14005 variables as for @samp{rejection-reason} below.
14006 Defaults to @samp{"Rejected: %s"}.
14009 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
14010 Human readable error message for rejection mails. You can use
14023 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
14026 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
14027 Delimiter character between local-part and detail in email
14029 Defaults to @samp{"+"}.
14032 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
14033 Header where the original recipient address (SMTP's RCPT TO:
14034 address) is taken from if not available elsewhere. With dovecot-lda -a
14035 parameter overrides this. A commonly used header for this is
14037 Defaults to @samp{""}.
14040 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
14041 Should saving a mail to a nonexistent mailbox automatically create
14043 Defaults to @samp{#f}.
14046 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
14047 Should automatically created mailboxes be also automatically
14049 Defaults to @samp{#f}.
14052 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
14053 Maximum IMAP command line length. Some clients generate very long
14054 command lines with huge mailboxes, so you may need to raise this if you
14055 get "Too long argument" or "IMAP command line too large" errors
14057 Defaults to @samp{64000}.
14060 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
14061 IMAP logout format string:
14064 total number of bytes read from client
14066 total number of bytes sent to client.
14068 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
14069 Defaults to @samp{"in=%i out=%o deleted=%@{deleted@} expunged=%@{expunged@} trashed=%@{trashed@} hdr_count=%@{fetch_hdr_count@} hdr_bytes=%@{fetch_hdr_bytes@} body_count=%@{fetch_body_count@} body_bytes=%@{fetch_body_bytes@}"}.
14072 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
14073 Override the IMAP CAPABILITY response. If the value begins with '+',
14074 add the given capabilities on top of the defaults (e.g. +XFOO XBAR).
14075 Defaults to @samp{""}.
14078 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
14079 How long to wait between "OK Still here" notifications when client
14081 Defaults to @samp{"2 mins"}.
14084 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
14085 ID field names and values to send to clients. Using * as the value
14086 makes Dovecot use the default value. The following fields have default
14087 values currently: name, version, os, os-version, support-url,
14089 Defaults to @samp{""}.
14092 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
14093 ID fields sent by client to log. * means everything.
14094 Defaults to @samp{""}.
14097 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
14098 Workarounds for various client bugs:
14101 @item delay-newmail
14102 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
14103 CHECK commands. Some clients ignore them otherwise, for example OSX
14104 Mail (<v2.1). Outlook Express breaks more badly though, without this it
14105 may show user "Message no longer in server" errors. Note that OE6
14106 still breaks even with this workaround if synchronization is set to
14109 @item tb-extra-mailbox-sep
14110 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
14111 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
14112 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
14114 @item tb-lsub-flags
14115 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g. mbox).
14116 This makes Thunderbird realize they aren't selectable and show them
14117 greyed out, instead of only later giving "not selectable" popup error.
14119 Defaults to @samp{()}.
14122 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
14123 Host allowed in URLAUTH URLs sent by client. "*" allows all.
14124 Defaults to @samp{""}.
14128 Whew! Lots of configuration options. The nice thing about it though is
14129 that GuixSD has a complete interface to Dovecot's configuration
14130 language. This allows not only a nice way to declare configurations,
14131 but also offers reflective capabilities as well: users can write code to
14132 inspect and transform configurations from within Scheme.
14134 However, it could be that you just want to get a @code{dovecot.conf} up
14135 and running. In that case, you can pass an
14136 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
14137 @code{dovecot-service}. As its name indicates, an opaque configuration
14138 does not have easy reflective capabilities.
14140 Available @code{opaque-dovecot-configuration} fields are:
14142 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
14143 The dovecot package.
14146 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
14147 The contents of the @code{dovecot.conf}, as a string.
14150 For example, if your @code{dovecot.conf} is just the empty string, you
14151 could instantiate a dovecot service like this:
14154 (dovecot-service #:config
14155 (opaque-dovecot-configuration
14159 @subsubheading OpenSMTPD Service
14161 @deffn {Scheme Variable} opensmtpd-service-type
14162 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
14163 service, whose value should be an @code{opensmtpd-configuration} object
14164 as in this example:
14167 (service opensmtpd-service-type
14168 (opensmtpd-configuration
14169 (config-file (local-file "./my-smtpd.conf"))))
14173 @deftp {Data Type} opensmtpd-configuration
14174 Data type representing the configuration of opensmtpd.
14177 @item @code{package} (default: @var{opensmtpd})
14178 Package object of the OpenSMTPD SMTP server.
14180 @item @code{config-file} (default: @var{%default-opensmtpd-file})
14181 File-like object of the OpenSMTPD configuration file to use. By default
14182 it listens on the loopback network interface, and allows for mail from
14183 users and daemons on the local machine, as well as permitting email to
14184 remote servers. Run @command{man smtpd.conf} for more information.
14189 @subsubheading Exim Service
14191 @cindex mail transfer agent (MTA)
14192 @cindex MTA (mail transfer agent)
14195 @deffn {Scheme Variable} exim-service-type
14196 This is the type of the @uref{https://exim.org, Exim} mail transfer
14197 agent (MTA), whose value should be an @code{exim-configuration} object
14198 as in this example:
14201 (service exim-service-type
14202 (exim-configuration
14203 (config-file (local-file "./my-exim.conf"))))
14207 In order to use an @code{exim-service-type} service you must also have a
14208 @code{mail-aliases-service-type} service present in your
14209 @code{operating-system} (even if it has no aliases).
14211 @deftp {Data Type} exim-configuration
14212 Data type representing the configuration of exim.
14215 @item @code{package} (default: @var{exim})
14216 Package object of the Exim server.
14218 @item @code{config-file} (default: @code{#f})
14219 File-like object of the Exim configuration file to use. If its value is
14220 @code{#f} then use the default configuration file from the package
14221 provided in @code{package}. The resulting configuration file is loaded
14222 after setting the @code{exim_user} and @code{exim_group} configuration
14228 @subsubheading Mail Aliases Service
14230 @cindex email aliases
14231 @cindex aliases, for email addresses
14233 @deffn {Scheme Variable} mail-aliases-service-type
14234 This is the type of the service which provides @code{/etc/aliases},
14235 specifying how to deliver mail to users on this system.
14238 (service mail-aliases-service-type
14239 '(("postmaster" "bob")
14240 ("bob" "bob@@example.com" "bob@@example2.com")))
14244 The configuration for a @code{mail-aliases-service-type} service is an
14245 association list denoting how to deliver mail that comes to this
14246 system. Each entry is of the form @code{(alias addresses ...)}, with
14247 @code{alias} specifying the local alias and @code{addresses} specifying
14248 where to deliver this user's mail.
14250 The aliases aren't required to exist as users on the local system. In
14251 the above example, there doesn't need to be a @code{postmaster} entry in
14252 the @code{operating-system}'s @code{user-accounts} in order to deliver
14253 the @code{postmaster} mail to @code{bob} (which subsequently would
14254 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
14256 @node Messaging Services
14257 @subsubsection Messaging Services
14262 The @code{(gnu services messaging)} module provides Guix service
14263 definitions for messaging services: currently only Prosody is supported.
14265 @subsubheading Prosody Service
14267 @deffn {Scheme Variable} prosody-service-type
14268 This is the type for the @uref{https://prosody.im, Prosody XMPP
14269 communication server}. Its value must be a @code{prosody-configuration}
14270 record as in this example:
14273 (service prosody-service-type
14274 (prosody-configuration
14275 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
14278 (int-component-configuration
14279 (hostname "conference.example.net")
14281 (mod-muc (mod-muc-configuration)))))
14284 (virtualhost-configuration
14285 (domain "example.net"))))))
14288 See below for details about @code{prosody-configuration}.
14292 By default, Prosody does not need much configuration. Only one
14293 @code{virtualhosts} field is needed: it specifies the domain you wish
14296 You can perform various sanity checks on the generated configuration
14297 with the @code{prosodyctl check} command.
14299 Prosodyctl will also help you to import certificates from the
14300 @code{letsencrypt} directory so that the @code{prosody} user can access
14301 them. See @url{https://prosody.im/doc/letsencrypt}.
14304 prosodyctl --root cert import /etc/letsencrypt/live
14307 The available configuration parameters follow. Each parameter
14308 definition is preceded by its type; for example, @samp{string-list foo}
14309 indicates that the @code{foo} parameter should be specified as a list of
14310 strings. Types starting with @code{maybe-} denote parameters that won't
14311 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
14313 There is also a way to specify the configuration as a string, if you
14314 have an old @code{prosody.cfg.lua} file that you want to port over from
14315 some other system; see the end for more details.
14317 The @code{file-object} type designates either a file-like object
14318 (@pxref{G-Expressions, file-like objects}) or a file name.
14320 @c The following documentation was initially generated by
14321 @c (generate-documentation) in (gnu services messaging). Manually maintained
14322 @c documentation is better, so we shouldn't hesitate to edit below as
14323 @c needed. However if the change you want to make to this documentation
14324 @c can be done in an automated way, it's probably easier to change
14325 @c (generate-documentation) than to make it below and have to deal with
14326 @c the churn as Prosody updates.
14328 Available @code{prosody-configuration} fields are:
14330 @deftypevr {@code{prosody-configuration} parameter} package prosody
14331 The Prosody package.
14334 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
14335 Location of the Prosody data storage directory. See
14336 @url{https://prosody.im/doc/configure}.
14337 Defaults to @samp{"/var/lib/prosody"}.
14340 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
14341 Additional plugin directories. They are searched in all the specified
14342 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
14343 Defaults to @samp{()}.
14346 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
14347 Every virtual host and component needs a certificate so that clients and
14348 servers can securely verify its identity. Prosody will automatically load
14349 certificates/keys from the directory specified here.
14350 Defaults to @samp{"/etc/prosody/certs"}.
14353 @deftypevr {@code{prosody-configuration} parameter} string-list admins
14354 This is a list of accounts that are admins for the server. Note that you
14355 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
14356 @url{https://prosody.im/doc/creating_accounts}.
14357 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
14358 Defaults to @samp{()}.
14361 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
14362 Enable use of libevent for better performance under high load. See
14363 @url{https://prosody.im/doc/libevent}.
14364 Defaults to @samp{#f}.
14367 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
14368 This is the list of modules Prosody will load on startup. It looks for
14369 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
14370 Documentation on modules can be found at:
14371 @url{https://prosody.im/doc/modules}.
14372 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
14375 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
14376 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
14377 should you want to disable them then add them to this list.
14378 Defaults to @samp{()}.
14381 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
14382 Path to a text file where the shared groups are defined. If this path is
14383 empty then @samp{mod_groups} does nothing. See
14384 @url{https://prosody.im/doc/modules/mod_groups}.
14385 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
14388 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
14389 Disable account creation by default, for security. See
14390 @url{https://prosody.im/doc/creating_accounts}.
14391 Defaults to @samp{#f}.
14394 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
14395 These are the SSL/TLS-related settings. Most of them are disabled so to
14396 use Prosody's defaults. If you do not completely understand these options, do
14397 not add them to your config, it is easy to lower the security of your server
14398 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
14400 Available @code{ssl-configuration} fields are:
14402 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
14403 This determines what handshake to use.
14406 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
14407 Path to your private key file.
14410 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
14411 Path to your certificate file.
14414 @deftypevr {@code{ssl-configuration} parameter} file-object capath
14415 Path to directory containing root certificates that you wish Prosody to
14416 trust when verifying the certificates of remote servers.
14417 Defaults to @samp{"/etc/ssl/certs"}.
14420 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
14421 Path to a file containing root certificates that you wish Prosody to trust.
14422 Similar to @code{capath} but with all certificates concatenated together.
14425 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
14426 A list of verification options (these mostly map to OpenSSL's
14427 @code{set_verify()} flags).
14430 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
14431 A list of general options relating to SSL/TLS. These map to OpenSSL's
14432 @code{set_options()}. For a full list of options available in LuaSec, see the
14436 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
14437 How long a chain of certificate authorities to check when looking for a
14438 trusted root certificate.
14441 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
14442 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
14443 clients, and in what order.
14446 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
14447 A path to a file containing parameters for Diffie-Hellman key exchange. You
14448 can create such a file with:
14449 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
14452 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
14453 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
14454 @samp{"secp384r1"}.
14457 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
14458 A list of "extra" verification options.
14461 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
14462 Password for encrypted private keys.
14467 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
14468 Whether to force all client-to-server connections to be encrypted or not.
14469 See @url{https://prosody.im/doc/modules/mod_tls}.
14470 Defaults to @samp{#f}.
14473 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
14474 Set of mechanisms that will never be offered. See
14475 @url{https://prosody.im/doc/modules/mod_saslauth}.
14476 Defaults to @samp{("DIGEST-MD5")}.
14479 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
14480 Whether to force all server-to-server connections to be encrypted or not.
14481 See @url{https://prosody.im/doc/modules/mod_tls}.
14482 Defaults to @samp{#f}.
14485 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
14486 Whether to require encryption and certificate authentication. This
14487 provides ideal security, but requires servers you communicate with to support
14488 encryption AND present valid, trusted certificates. See
14489 @url{https://prosody.im/doc/s2s#security}.
14490 Defaults to @samp{#f}.
14493 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
14494 Many servers don't support encryption or have invalid or self-signed
14495 certificates. You can list domains here that will not be required to
14496 authenticate using certificates. They will be authenticated using DNS. See
14497 @url{https://prosody.im/doc/s2s#security}.
14498 Defaults to @samp{()}.
14501 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
14502 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
14503 valid certificates for some domains by specifying a list here. See
14504 @url{https://prosody.im/doc/s2s#security}.
14505 Defaults to @samp{()}.
14508 @deftypevr {@code{prosody-configuration} parameter} string authentication
14509 Select the authentication backend to use. The default provider stores
14510 passwords in plaintext and uses Prosody's configured data storage to store the
14511 authentication data. If you do not trust your server please see
14512 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
14513 about using the hashed backend. See also
14514 @url{https://prosody.im/doc/authentication}
14515 Defaults to @samp{"internal_plain"}.
14518 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
14519 Set logging options. Advanced logging configuration is not yet supported
14520 by the GuixSD Prosody Service. See @url{https://prosody.im/doc/logging}.
14521 Defaults to @samp{"*syslog"}.
14524 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
14525 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
14526 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
14529 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
14530 Maximum allowed size of the HTTP body (in bytes).
14533 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
14534 Some modules expose their own URL in various ways. This URL is built
14535 from the protocol, host and port used. If Prosody sits behind a proxy, the
14536 public URL will be @code{http-external-url} instead. See
14537 @url{https://prosody.im/doc/http#external_url}.
14540 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
14541 A host in Prosody is a domain on which user accounts can be created. For
14542 example if you want your users to have addresses like
14543 @samp{"john.smith@@example.com"} then you need to add a host
14544 @samp{"example.com"}. All options in this list will apply only to this host.
14546 Note: the name "virtual" host is used in configuration to avoid confusion with
14547 the actual physical host that Prosody is installed on. A single Prosody
14548 instance can serve many domains, each one defined as a VirtualHost entry in
14549 Prosody's configuration. Conversely a server that hosts a single domain would
14550 have just one VirtualHost entry.
14552 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
14554 Available @code{virtualhost-configuration} fields are:
14556 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:
14557 @deftypevr {@code{virtualhost-configuration} parameter} string domain
14558 Domain you wish Prosody to serve.
14563 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
14564 Components are extra services on a server which are available to clients,
14565 usually on a subdomain of the main server (such as
14566 @samp{"mycomponent.example.com"}). Example components might be chatroom
14567 servers, user directories, or gateways to other protocols.
14569 Internal components are implemented with Prosody-specific plugins. To add an
14570 internal component, you simply fill the hostname field, and the plugin you wish
14571 to use for the component.
14573 See @url{https://prosody.im/doc/components}.
14574 Defaults to @samp{()}.
14576 Available @code{int-component-configuration} fields are:
14578 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:
14579 @deftypevr {@code{int-component-configuration} parameter} string hostname
14580 Hostname of the component.
14583 @deftypevr {@code{int-component-configuration} parameter} string plugin
14584 Plugin you wish to use for the component.
14587 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
14588 Multi-user chat (MUC) is Prosody's module for allowing you to create
14589 hosted chatrooms/conferences for XMPP users.
14591 General information on setting up and using multi-user chatrooms can be found
14592 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
14593 which you should read if you are new to XMPP chatrooms.
14595 See also @url{https://prosody.im/doc/modules/mod_muc}.
14597 Available @code{mod-muc-configuration} fields are:
14599 @deftypevr {@code{mod-muc-configuration} parameter} string name
14600 The name to return in service discovery responses.
14601 Defaults to @samp{"Prosody Chatrooms"}.
14604 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
14605 If @samp{#t}, this will only allow admins to create new chatrooms.
14606 Otherwise anyone can create a room. The value @samp{"local"} restricts room
14607 creation to users on the service's parent domain. E.g. @samp{user@@example.com}
14608 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
14609 restricts to service administrators only.
14610 Defaults to @samp{#f}.
14613 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
14614 Maximum number of history messages that will be sent to the member that has
14615 just joined the room.
14616 Defaults to @samp{20}.
14623 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
14624 External components use XEP-0114, which most standalone components
14625 support. To add an external component, you simply fill the hostname field. See
14626 @url{https://prosody.im/doc/components}.
14627 Defaults to @samp{()}.
14629 Available @code{ext-component-configuration} fields are:
14631 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:
14632 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
14633 Password which the component will use to log in.
14636 @deftypevr {@code{ext-component-configuration} parameter} string hostname
14637 Hostname of the component.
14642 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
14643 Port(s) Prosody listens on for component connections.
14644 Defaults to @samp{(5347)}.
14647 @deftypevr {@code{prosody-configuration} parameter} string component-interface
14648 Interface Prosody listens on for component connections.
14649 Defaults to @samp{"127.0.0.1"}.
14652 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
14653 Raw content that will be added to the configuration file.
14656 It could be that you just want to get a @code{prosody.cfg.lua}
14657 up and running. In that case, you can pass an
14658 @code{opaque-prosody-configuration} record as the value of
14659 @code{prosody-service-type}. As its name indicates, an opaque configuration
14660 does not have easy reflective capabilities.
14661 Available @code{opaque-prosody-configuration} fields are:
14663 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
14664 The prosody package.
14667 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
14668 The contents of the @code{prosody.cfg.lua} to use.
14671 For example, if your @code{prosody.cfg.lua} is just the empty
14672 string, you could instantiate a prosody service like this:
14675 (service prosody-service-type
14676 (opaque-prosody-configuration
14677 (prosody.cfg.lua "")))
14680 @c end of Prosody auto-generated documentation
14682 @subsubheading BitlBee Service
14684 @cindex IRC (Internet Relay Chat)
14685 @cindex IRC gateway
14686 @url{http://bitlbee.org,BitlBee} is a gateway that provides an IRC
14687 interface to a variety of messaging protocols such as XMPP.
14689 @defvr {Scheme Variable} bitlbee-service-type
14690 This is the service type for the @url{http://bitlbee.org,BitlBee} IRC
14691 gateway daemon. Its value is a @code{bitlbee-configuration} (see
14694 To have BitlBee listen on port 6667 on localhost, add this line to your
14698 (service bitlbee-service-type)
14702 @deftp {Data Type} bitlbee-configuration
14703 This is the configuration for BitlBee, with the following fields:
14706 @item @code{interface} (default: @code{"127.0.0.1"})
14707 @itemx @code{port} (default: @code{6667})
14708 Listen on the network interface corresponding to the IP address
14709 specified in @var{interface}, on @var{port}.
14711 When @var{interface} is @code{127.0.0.1}, only local clients can
14712 connect; when it is @code{0.0.0.0}, connections can come from any
14713 networking interface.
14715 @item @code{package} (default: @code{bitlbee})
14716 The BitlBee package to use.
14718 @item @code{extra-settings} (default: @code{""})
14719 Configuration snippet added as-is to the BitlBee configuration file.
14724 @node Telephony Services
14725 @subsubsection Telephony Services
14727 @cindex Murmur (VoIP server)
14728 @cindex VoIP server
14729 This section describes how to set up and run a Murmur server. Murmur is
14730 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
14733 @deftp {Data Type} murmur-configuration
14734 The service type for the Murmur server. An example configuration can
14738 (service murmur-service-type
14739 (murmur-configuration
14741 "Welcome to this Mumble server running on GuixSD!")
14742 (cert-required? #t) ;disallow text password logins
14743 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
14744 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
14747 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
14748 password with the command that is printed during the activation phase.
14750 It is recommended to register a normal Mumble user account
14751 and grant it admin or moderator rights.
14752 You can use the @code{mumble} client to
14753 login as new normal user, register yourself, and log out.
14754 For the next step login with the name @code{SuperUser} use
14755 the @code{SuperUser} password that you set previously,
14756 and grant your newly registered mumble user administrator or moderator
14757 rights and create some channels.
14759 Available @code{murmur-configuration} fields are:
14762 @item @code{package} (default: @code{mumble})
14763 Package that contains @code{bin/murmurd}.
14765 @item @code{user} (default: @code{"murmur"})
14766 User who will run the Murmur server.
14768 @item @code{group} (default: @code{"murmur"})
14769 Group of the user who will run the murmur server.
14771 @item @code{port} (default: @code{64738})
14772 Port on which the server will listen.
14774 @item @code{welcome-text} (default: @code{""})
14775 Welcome text sent to clients when they connect.
14777 @item @code{server-password} (default: @code{""})
14778 Password the clients have to enter in order to connect.
14780 @item @code{max-users} (default: @code{100})
14781 Maximum of users that can be connected to the server at once.
14783 @item @code{max-user-bandwidth} (default: @code{#f})
14784 Maximum voice traffic a user can send per second.
14786 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
14787 File name of the sqlite database.
14788 The service's user will become the owner of the directory.
14790 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
14791 File name of the log file.
14792 The service's user will become the owner of the directory.
14794 @item @code{autoban-attempts} (default: @code{10})
14795 Maximum number of logins a user can make in @code{autoban-timeframe}
14796 without getting auto banned for @code{autoban-time}.
14798 @item @code{autoban-timeframe} (default: @code{120})
14799 Timeframe for autoban in seconds.
14801 @item @code{autoban-time} (default: @code{300})
14802 Amount of time in seconds for which a client gets banned
14803 when violating the autoban limits.
14805 @item @code{opus-threshold} (default: @code{100})
14806 Percentage of clients that need to support opus
14807 before switching over to opus audio codec.
14809 @item @code{channel-nesting-limit} (default: @code{10})
14810 How deep channels can be nested at maximum.
14812 @item @code{channelname-regex} (default: @code{#f})
14813 A string in from of a Qt regular expression that channel names must conform to.
14815 @item @code{username-regex} (default: @code{#f})
14816 A string in from of a Qt regular expression that user names must conform to.
14818 @item @code{text-message-length} (default: @code{5000})
14819 Maximum size in bytes that a user can send in one text chat message.
14821 @item @code{image-message-length} (default: @code{(* 128 1024)})
14822 Maximum size in bytes that a user can send in one image message.
14824 @item @code{cert-required?} (default: @code{#f})
14825 If it is set to @code{#t} clients that use weak password authentification
14826 will not be accepted. Users must have completed the certificate wizard to join.
14828 @item @code{remember-channel?} (defualt @code{#f})
14829 Should murmur remember the last channel each user was in when they disconnected
14830 and put them into the remembered channel when they rejoin.
14832 @item @code{allow-html?} (default: @code{#f})
14833 Should html be allowed in text messages, user comments, and channel descriptions.
14835 @item @code{allow-ping?} (default: @code{#f})
14836 Setting to true exposes the current user count, the maximum user count, and
14837 the server's maximum bandwidth per client to unauthenticated users. In the
14838 Mumble client, this information is shown in the Connect dialog.
14840 Disabling this setting will prevent public listing of the server.
14842 @item @code{bonjour?} (default: @code{#f})
14843 Should the server advertise itself in the local network through the bonjour protocol.
14845 @item @code{send-version?} (default: @code{#f})
14846 Should the murmur server version be exposed in ping requests.
14848 @item @code{log-days} (default: @code{31})
14849 Murmur also stores logs in the database, which are accessible via RPC.
14850 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
14851 or -1 to disable logging to the database.
14853 @item @code{obfuscate-ips?} (default @code{#t})
14854 Should logged ips be obfuscated to protect the privacy of users.
14856 @item @code{ssl-cert} (default: @code{#f})
14857 File name of the SSL/TLS certificate used for encrypted connections.
14860 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
14862 @item @code{ssl-key} (default: @code{#f})
14863 Filepath to the ssl private key used for encrypted connections.
14865 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
14868 @item @code{ssl-dh-params} (default: @code{#f})
14869 File name of a PEM-encoded file with Diffie-Hellman parameters
14870 for the SSL/TLS encryption. Alternatively you set it to
14871 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
14872 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
14874 @item @code{ssl-ciphers} (default: @code{#f})
14875 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
14878 This option is specified using
14879 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
14880 OpenSSL cipher list notation}.
14882 It is recommended that you try your cipher string using 'openssl ciphers <string>'
14883 before setting it here, to get a feel for which cipher suites you will get.
14884 After setting this option, it is recommend that you inspect your Murmur log
14885 to ensure that Murmur is using the cipher suites that you expected it to.
14887 Note: Changing this option may impact the backwards compatibility of your
14888 Murmur server, and can remove the ability for older Mumble clients to be able
14891 @item @code{public-registration} (default: @code{#f})
14892 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
14894 You can optionally register your server in the public server list that the
14895 @code{mumble} client shows on startup.
14896 You cannot register your server if you have set a @code{server-password},
14897 or set @code{allow-ping} to @code{#f}.
14899 It might take a few hours until it shows up in the public list.
14901 @item @code{file} (default: @code{#f})
14902 Optional alternative override for this configuration.
14906 @deftp {Data Type} murmur-public-registration-configuration
14907 Configuration for public registration of a murmur service.
14911 This is a display name for your server. Not to be confused with the hostname.
14913 @item @code{password}
14914 A password to identify your registration.
14915 Subsequent updates will need the same password. Don't lose your password.
14918 This should be a @code{http://} or @code{https://} link to your web
14921 @item @code{hostname} (default: @code{#f})
14922 By default your server will be listed by its IP address.
14923 If it is set your server will be linked by this host name instead.
14929 @node Monitoring Services
14930 @subsubsection Monitoring Services
14932 @subsubheading Tailon Service
14934 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
14935 viewing and searching log files.
14937 The following example will configure the service with default values.
14938 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
14941 (service tailon-service-type)
14944 The following example customises more of the Tailon configuration,
14945 adding @command{sed} to the list of allowed commands.
14948 (service tailon-service-type
14949 (tailon-configuration
14951 (tailon-configuration-file
14952 (allowed-commands '("tail" "grep" "awk" "sed"))))))
14956 @deftp {Data Type} tailon-configuration
14957 Data type representing the configuration of Tailon.
14958 This type has the following parameters:
14961 @item @code{config-file} (default: @code{(tailon-configuration-file)})
14962 The configuration file to use for Tailon. This can be set to a
14963 @dfn{tailon-configuration-file} record value, or any gexp
14964 (@pxref{G-Expressions}).
14966 For example, to instead use a local file, the @code{local-file} function
14970 (service tailon-service-type
14971 (tailon-configuration
14972 (config-file (local-file "./my-tailon.conf"))))
14975 @item @code{package} (default: @code{tailon})
14976 The tailon package to use.
14981 @deftp {Data Type} tailon-configuration-file
14982 Data type representing the configuration options for Tailon.
14983 This type has the following parameters:
14986 @item @code{files} (default: @code{(list "/var/log")})
14987 List of files to display. The list can include strings for a single file
14988 or directory, or a list, where the first item is the name of a
14989 subsection, and the remaining items are the files or directories in that
14992 @item @code{bind} (default: @code{"localhost:8080"})
14993 Address and port to which Tailon should bind on.
14995 @item @code{relative-root} (default: @code{#f})
14996 URL path to use for Tailon, set to @code{#f} to not use a path.
14998 @item @code{allow-transfers?} (default: @code{#t})
14999 Allow downloading the log files in the web interface.
15001 @item @code{follow-names?} (default: @code{#t})
15002 Allow tailing of not-yet existent files.
15004 @item @code{tail-lines} (default: @code{200})
15005 Number of lines to read initially from each file.
15007 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
15008 Commands to allow running. By default, @code{sed} is disabled.
15010 @item @code{debug?} (default: @code{#f})
15011 Set @code{debug?} to @code{#t} to show debug messages.
15013 @item @code{wrap-lines} (default: @code{#t})
15014 Initial line wrapping state in the web interface. Set to @code{#t} to
15015 initially wrap lines (the default), or to @code{#f} to initially not
15018 @item @code{http-auth} (default: @code{#f})
15019 HTTP authentication type to use. Set to @code{#f} to disable
15020 authentication (the default). Supported values are @code{"digest"} or
15023 @item @code{users} (default: @code{#f})
15024 If HTTP authentication is enabled (see @code{http-auth}), access will be
15025 restricted to the credentials provided here. To configure users, use a
15026 list of pairs, where the first element of the pair is the username, and
15027 the 2nd element of the pair is the password.
15030 (tailon-configuration-file
15031 (http-auth "basic")
15032 (users '(("user1" . "password1")
15033 ("user2" . "password2"))))
15040 @subsubheading Darkstat Service
15042 Darkstat is a packet sniffer that captures network traffic, calculates
15043 statistics about usage, and serves reports over HTTP.
15045 @defvar {Scheme Variable} darkstat-service-type
15046 This is the service type for the
15047 @uref{https://unix4lyfe.org/darkstat/, darkstat}
15048 service, its value must be a @code{darkstat-configuration} record as in
15052 (service darkstat-service-type
15053 (darkstat-configuration
15054 (interface "eno1")))
15058 @deftp {Data Type} darkstat-configuration
15059 Data type representing the configuration of @command{darkstat}.
15062 @item @code{package} (default: @code{darkstat})
15063 The darkstat package to use.
15065 @item @code{interface}
15066 Capture traffic on the specified network interface.
15068 @item @code{port} (default: @code{"667"})
15069 Bind the web interface to the specified port.
15071 @item @code{bind-address} (default: @code{"127.0.0.1"})
15072 Bind the web interface to the specified address.
15074 @item @code{base} (default: @code{"/"})
15075 Specify the path of the base URL. This can be useful if
15076 @command{darkstat} is accessed via a reverse proxy.
15082 @node Kerberos Services
15083 @subsubsection Kerberos Services
15086 The @code{(gnu services kerberos)} module provides services relating to
15087 the authentication protocol @dfn{Kerberos}.
15089 @subsubheading Krb5 Service
15091 Programs using a Kerberos client library normally
15092 expect a configuration file in @file{/etc/krb5.conf}.
15093 This service generates such a file from a definition provided in the
15094 operating system declaration.
15095 It does not cause any daemon to be started.
15097 No ``keytab'' files are provided by this service---you must explicitly create them.
15098 This service is known to work with the MIT client library, @code{mit-krb5}.
15099 Other implementations have not been tested.
15101 @defvr {Scheme Variable} krb5-service-type
15102 A service type for Kerberos 5 clients.
15106 Here is an example of its use:
15108 (service krb5-service-type
15109 (krb5-configuration
15110 (default-realm "EXAMPLE.COM")
15111 (allow-weak-crypto? #t)
15114 (name "EXAMPLE.COM")
15115 (admin-server "groucho.example.com")
15116 (kdc "karl.example.com"))
15119 (admin-server "kerb-admin.argrx.edu")
15120 (kdc "keys.argrx.edu"))))))
15124 This example provides a Kerberos@tie{}5 client configuration which:
15126 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
15127 of which have distinct administration servers and key distribution centers;
15128 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
15129 specified by clients;
15130 @item Accepts services which only support encryption types known to be weak.
15133 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
15134 Only the most commonly used ones are described here.
15135 For a full list, and more detailed explanation of each, see the MIT
15136 @uref{http://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
15140 @deftp {Data Type} krb5-realm
15141 @cindex realm, kerberos
15144 This field is a string identifying the name of the realm.
15145 A common convention is to use the fully qualified DNS name of your organization,
15146 converted to upper case.
15148 @item @code{admin-server}
15149 This field is a string identifying the host where the administration server is
15153 This field is a string identifying the key distribution center
15158 @deftp {Data Type} krb5-configuration
15161 @item @code{allow-weak-crypto?} (default: @code{#f})
15162 If this flag is @code{#t} then services which only offer encryption algorithms
15163 known to be weak will be accepted.
15165 @item @code{default-realm} (default: @code{#f})
15166 This field should be a string identifying the default Kerberos
15167 realm for the client.
15168 You should set this field to the name of your Kerberos realm.
15169 If this value is @code{#f}
15170 then a realm must be specified with every Kerberos principal when invoking programs
15171 such as @command{kinit}.
15173 @item @code{realms}
15174 This should be a non-empty list of @code{krb5-realm} objects, which clients may
15176 Normally, one of them will have a @code{name} field matching the @code{default-realm}
15182 @subsubheading PAM krb5 Service
15185 The @code{pam-krb5} service allows for login authentication and password
15186 management via Kerberos.
15187 You will need this service if you want PAM enabled applications to authenticate
15188 users using Kerberos.
15190 @defvr {Scheme Variable} pam-krb5-service-type
15191 A service type for the Kerberos 5 PAM module.
15194 @deftp {Data Type} pam-krb5-configuration
15195 Data type representing the configuration of the Kerberos 5 PAM module
15196 This type has the following parameters:
15198 @item @code{pam-krb5} (default: @code{pam-krb5})
15199 The pam-krb5 package to use.
15201 @item @code{minimum-uid} (default: @code{1000})
15202 The smallest user ID for which Kerberos authentications should be attempted.
15203 Local accounts with lower values will silently fail to authenticate.
15209 @subsubsection Web Services
15214 The @code{(gnu services web)} module provides the Apache HTTP Server,
15215 the nginx web server, and also a fastcgi wrapper daemon.
15217 @subsubheading Apache HTTP Server
15219 @deffn {Scheme Variable} httpd-service-type
15220 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
15221 (@dfn{httpd}). The value for this service type is a
15222 @code{https-configuration} record.
15224 A simple example configuration is given below.
15227 (service httpd-service-type
15228 (httpd-configuration
15231 (server-name "www.example.com")
15232 (document-root "/srv/http/www.example.com")))))
15235 Other services can also extend the @code{httpd-service-type} to add to
15239 (simple-service 'my-extra-server httpd-service-type
15243 (list (string-append
15244 "ServerName "www.example.com
15245 DocumentRoot \"/srv/http/www.example.com\"")))))
15249 The details for the @code{httpd-configuration}, @code{httpd-module},
15250 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
15253 @deffn {Data Type} httpd-configuration
15254 This data type represents the configuration for the httpd service.
15257 @item @code{package} (default: @code{httpd})
15258 The httpd package to use.
15260 @item @code{pid-file} (default: @code{"/var/run/httpd"})
15261 The pid file used by the shepherd-service.
15263 @item @code{config} (default: @code{(httpd-config-file)})
15264 The configuration file to use with the httpd service. The default value
15265 is a @code{httpd-config-file} record, but this can also be a different
15266 G-expression that generates a file, for example a @code{plain-file}. A
15267 file outside of the store can also be specified through a string.
15272 @deffn {Data Type} httpd-module
15273 This data type represents a module for the httpd service.
15277 The name of the module.
15280 The file for the module. This can be relative to the httpd package being
15281 used, the absolute location of a file, or a G-expression for a file
15282 within the store, for example @code{(file-append mod-wsgi
15283 "/modules/mod_wsgi.so")}.
15288 @deffn {Data Type} httpd-config-file
15289 This data type represents a configuration file for the httpd service.
15292 @item @code{modules} (default: @code{%default-httpd-modules})
15293 The modules to load. Additional modules can be added here, or loaded by
15294 additional configuration.
15296 @item @code{server-root} (default: @code{httpd})
15297 The @code{ServerRoot} in the configuration file, defaults to the httpd
15298 package. Directives including @code{Include} and @code{LoadModule} are
15299 taken as relative to the server root.
15301 @item @code{server-name} (default: @code{#f})
15302 The @code{ServerName} in the configuration file, used to specify the
15303 request scheme, hostname and port that the server uses to identify
15306 This doesn't need to be set in the server config, and can be specifyed
15307 in virtual hosts. The default is @code{#f} to not specify a
15310 @item @code{document-root} (default: @code{"/srv/http"})
15311 The @code{DocumentRoot} from which files will be served.
15313 @item @code{listen} (default: @code{'("80")})
15314 The list of values for the @code{Listen} directives in the config
15315 file. The value should be a list of strings, when each string can
15316 specify the port number to listen on, and optionally the IP address and
15319 @item @code{pid-file} (default: @code{"/var/run/httpd"})
15320 The @code{PidFile} to use. This should match the @code{pid-file} set in
15321 the @code{httpd-configuration} so that the Shepherd service is
15322 configured correctly.
15324 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
15325 The @code{ErrorLog} to which the server will log errors.
15327 @item @code{user} (default: @code{"httpd"})
15328 The @code{User} which the server will answer requests as.
15330 @item @code{group} (default: @code{"httpd"})
15331 The @code{Group} which the server will answer requests as.
15333 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
15334 A flat list of strings and G-expressions which will be added to the end
15335 of the configuration file.
15337 Any values which the service is extended with will be appended to this
15343 @deffn {Data Type} httpd-virtualhost
15344 This data type represents a virtualhost configuration block for the httpd service.
15346 These should be added to the extra-config for the httpd-service.
15349 (simple-service 'my-extra-server httpd-service-type
15353 (list (string-append
15354 "ServerName "www.example.com
15355 DocumentRoot \"/srv/http/www.example.com\"")))))
15359 @item @code{addresses-and-ports}
15360 The addresses and ports for the @code{VirtualHost} directive.
15362 @item @code{contents}
15363 The contents of the @code{VirtualHost} directive, this should be a list
15364 of strings and G-expressions.
15369 @subsubheading NGINX
15371 @deffn {Scheme Variable} nginx-service-type
15372 Service type for the @uref{https://nginx.org/,NGinx} web server. The
15373 value for this service type is a @code{<nginx-configuration>} record.
15375 A simple example configuration is given below.
15378 (service nginx-service-type
15379 (nginx-configuration
15381 (list (nginx-server-configuration
15382 (server-name '("www.example.com"))
15383 (root "/srv/http/www.example.com"))))))
15386 In addition to adding server blocks to the service configuration
15387 directly, this service can be extended by other services to add server
15388 blocks, as in this example:
15391 (simple-service 'my-extra-server nginx-service-type
15392 (list (nginx-server-configuration
15393 (root "/srv/http/extra-website")
15394 (try-files (list "$uri" "$uri/index.html")))))
15398 At startup, @command{nginx} has not yet read its configuration file, so
15399 it uses a default file to log error messages. If it fails to load its
15400 configuration file, that is where error messages are logged. After the
15401 configuration file is loaded, the default error log file changes as per
15402 configuration. In our case, startup error messages can be found in
15403 @file{/var/run/nginx/logs/error.log}, and after configuration in
15404 @file{/var/log/nginx/error.log}. The second location can be changed
15405 with the @var{log-directory} configuration option.
15407 @deffn {Data Type} nginx-configuration
15408 This data type represents the configuration for NGinx. Some
15409 configuration can be done through this and the other provided record
15410 types, or alternatively, a config file can be provided.
15413 @item @code{nginx} (default: @code{nginx})
15414 The nginx package to use.
15416 @item @code{log-directory} (default: @code{"/var/log/nginx"})
15417 The directory to which NGinx will write log files.
15419 @item @code{run-directory} (default: @code{"/var/run/nginx"})
15420 The directory in which NGinx will create a pid file, and write temporary
15423 @item @code{server-blocks} (default: @code{'()})
15424 A list of @dfn{server blocks} to create in the generated configuration
15425 file, the elements should be of type
15426 @code{<nginx-server-configuration>}.
15428 The following example would setup NGinx to serve @code{www.example.com}
15429 from the @code{/srv/http/www.example.com} directory, without using
15432 (service nginx-service-type
15433 (nginx-configuration
15435 (list (nginx-server-configuration
15436 (server-name '("www.example.com"))
15437 (root "/srv/http/www.example.com"))))))
15440 @item @code{upstream-blocks} (default: @code{'()})
15441 A list of @dfn{upstream blocks} to create in the generated configuration
15442 file, the elements should be of type
15443 @code{<nginx-upstream-configuration>}.
15445 Configuring upstreams through the @code{upstream-blocks} can be useful
15446 when combined with @code{locations} in the
15447 @code{<nginx-server-configuration>} records. The following example
15448 creates a server configuration with one location configuration, that
15449 will proxy requests to a upstream configuration, which will handle
15450 requests with two servers.
15455 (nginx-configuration
15457 (list (nginx-server-configuration
15458 (server-name '("www.example.com"))
15459 (root "/srv/http/www.example.com")
15462 (nginx-location-configuration
15464 (body '("proxy_pass http://server-proxy;"))))))))
15466 (list (nginx-upstream-configuration
15467 (name "server-proxy")
15468 (servers (list "server1.example.com"
15469 "server2.example.com")))))))
15472 @item @code{file} (default: @code{#f})
15473 If a configuration @var{file} is provided, this will be used, rather than
15474 generating a configuration file from the provided @code{log-directory},
15475 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
15476 proper operation, these arguments should match what is in @var{file} to ensure
15477 that the directories are created when the service is activated.
15479 This can be useful if you have an existing configuration file, or it's
15480 not possible to do what is required through the other parts of the
15481 nginx-configuration record.
15483 @item @code{server-names-hash-bucket-size} (default: @code{#f})
15484 Bucket size for the server names hash tables, defaults to @code{#f} to
15485 use the size of the processors cache line.
15487 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
15488 Maximum bucket size for the server names hash tables.
15493 @deftp {Data Type} nginx-server-configuration
15494 Data type representing the configuration of an nginx server block.
15495 This type has the following parameters:
15498 @item @code{listen} (default: @code{'("80" "443 ssl")})
15499 Each @code{listen} directive sets the address and port for IP, or the
15500 path for a UNIX-domain socket on which the server will accept requests.
15501 Both address and port, or only address or only port can be specified.
15502 An address may also be a hostname, for example:
15505 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
15508 @item @code{server-name} (default: @code{(list 'default)})
15509 A list of server names this server represents. @code{'default} represents the
15510 default server for connections matching no other server.
15512 @item @code{root} (default: @code{"/srv/http"})
15513 Root of the website nginx will serve.
15515 @item @code{locations} (default: @code{'()})
15516 A list of @dfn{nginx-location-configuration} or
15517 @dfn{nginx-named-location-configuration} records to use within this
15520 @item @code{index} (default: @code{(list "index.html")})
15521 Index files to look for when clients ask for a directory. If it cannot be found,
15522 Nginx will send the list of files in the directory.
15524 @item @code{try-files} (default: @code{'()})
15525 A list of files whose existence is checked in the specified order.
15526 @code{nginx} will use the first file it finds to process the request.
15528 @item @code{ssl-certificate} (default: @code{#f})
15529 Where to find the certificate for secure connections. Set it to @code{#f} if
15530 you don't have a certificate or you don't want to use HTTPS.
15532 @item @code{ssl-certificate-key} (default: @code{#f})
15533 Where to find the private key for secure connections. Set it to @code{#f} if
15534 you don't have a key or you don't want to use HTTPS.
15536 @item @code{server-tokens?} (default: @code{#f})
15537 Whether the server should add its configuration to response.
15539 @item @code{raw-content} (default: @code{'()})
15540 A list of raw lines added to the server block.
15545 @deftp {Data Type} nginx-upstream-configuration
15546 Data type representing the configuration of an nginx @code{upstream}
15547 block. This type has the following parameters:
15551 Name for this group of servers.
15553 @item @code{servers}
15554 Specify the addresses of the servers in the group. The address can be
15555 specified as a IP address (e.g. @samp{127.0.0.1}), domain name
15556 (e.g. @samp{backend1.example.com}) or a path to a UNIX socket using the
15557 prefix @samp{unix:}. For addresses using an IP address or domain name,
15558 the default port is 80, and a different port can be specified
15564 @deftp {Data Type} nginx-location-configuration
15565 Data type representing the configuration of an nginx @code{location}
15566 block. This type has the following parameters:
15570 URI which this location block matches.
15572 @anchor{nginx-location-configuration body}
15574 Body of the location block, specified as a list of strings. This can contain
15576 configuration directives. For example, to pass requests to a upstream
15577 server group defined using an @code{nginx-upstream-configuration} block,
15578 the following directive would be specified in the body @samp{(list "proxy_pass
15579 http://upstream-name;")}.
15584 @deftp {Data Type} nginx-named-location-configuration
15585 Data type representing the configuration of an nginx named location
15586 block. Named location blocks are used for request redirection, and not
15587 used for regular request processing. This type has the following
15592 Name to identify this location block.
15595 @xref{nginx-location-configuration body}, as the body for named location
15596 blocks can be used in a similar way to the
15597 @code{nginx-location-configuration body}. One restriction is that the
15598 body of a named location block cannot contain location blocks.
15605 FastCGI is an interface between the front-end and the back-end of a web
15606 service. It is a somewhat legacy facility; new web services should
15607 generally just talk HTTP between the front-end and the back-end.
15608 However there are a number of back-end services such as PHP or the
15609 optimized HTTP Git repository access that use FastCGI, so we have
15610 support for it in Guix.
15612 To use FastCGI, you configure the front-end web server (e.g., nginx) to
15613 dispatch some subset of its requests to the fastcgi backend, which
15614 listens on a local TCP or UNIX socket. There is an intermediary
15615 @code{fcgiwrap} program that sits between the actual backend process and
15616 the web server. The front-end indicates which backend program to run,
15617 passing that information to the @code{fcgiwrap} process.
15619 @defvr {Scheme Variable} fcgiwrap-service-type
15620 A service type for the @code{fcgiwrap} FastCGI proxy.
15623 @deftp {Data Type} fcgiwrap-configuration
15624 Data type representing the configuration of the @code{fcgiwrap} serice.
15625 This type has the following parameters:
15627 @item @code{package} (default: @code{fcgiwrap})
15628 The fcgiwrap package to use.
15630 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
15631 The socket on which the @code{fcgiwrap} process should listen, as a
15632 string. Valid @var{socket} values include
15633 @code{unix:@var{/path/to/unix/socket}},
15634 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
15635 @code{tcp6:[@var{ipv6_addr}]:port}.
15637 @item @code{user} (default: @code{fcgiwrap})
15638 @itemx @code{group} (default: @code{fcgiwrap})
15639 The user and group names, as strings, under which to run the
15640 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
15641 the user asks for the specific user or group names @code{fcgiwrap} that
15642 the corresponding user and/or group is present on the system.
15644 It is possible to configure a FastCGI-backed web service to pass HTTP
15645 authentication information from the front-end to the back-end, and to
15646 allow @code{fcgiwrap} to run the back-end process as a corresponding
15647 local user. To enable this capability on the back-end., run
15648 @code{fcgiwrap} as the @code{root} user and group. Note that this
15649 capability also has to be configured on the front-end as well.
15654 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
15655 with some additional features useful for sites of any size.
15657 These features include:
15659 @item Adaptive process spawning
15660 @item Basic statistics (similar to Apache's mod_status)
15661 @item Advanced process management with graceful stop/start
15662 @item Ability to start workers with different uid/gid/chroot/environment
15663 and different php.ini (replaces safe_mode)
15664 @item Stdout & stderr logging
15665 @item Emergency restart in case of accidental opcode cache destruction
15666 @item Accelerated upload support
15667 @item Support for a "slowlog"
15668 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
15669 a special function to finish request & flush all data while continuing to do
15670 something time-consuming (video converting, stats processing, etc.)
15674 @defvr {Scheme Variable} php-fpm-service-type
15675 A Service type for @code{php-fpm}.
15678 @deftp {Data Type} php-fpm-configuration
15679 Data Type for php-fpm service configuration.
15681 @item @code{php} (default: @code{php})
15682 The php package to use.
15683 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
15684 The address on which to accept FastCGI requests. Valid syntaxes are:
15686 @item @code{"ip.add.re.ss:port"}
15687 Listen on a TCP socket to a specific address on a specific port.
15688 @item @code{"port"}
15689 Listen on a TCP socket to all addresses on a specific port.
15690 @item @code{"/path/to/unix/socket"}
15691 Listen on a unix socket.
15694 @item @code{user} (default: @code{php-fpm})
15695 User who will own the php worker processes.
15696 @item @code{group} (default: @code{php-fpm})
15697 Group of the worker processes.
15698 @item @code{socket-user} (default: @code{php-fpm})
15699 User who can speak to the php-fpm socket.
15700 @item @code{socket-group} (default: @code{php-fpm})
15701 Group that can speak to the php-fpm socket.
15702 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
15703 The process id of the php-fpm process is written to this file
15704 once the service has started.
15705 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
15706 Log for the php-fpm master process.
15707 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
15708 Detailed settings for the php-fpm process manager.
15711 @item @code{<php-fpm-dynamic-process-manager-configuration>}
15712 @item @code{<php-fpm-static-process-manager-configuration>}
15713 @item @code{<php-fpm-on-demand-process-manager-configuration>}
15715 @item @code{display-errors} (default @code{#f})
15716 Determines wether php errors and warning should be sent to clients
15717 and displayed in their browsers.
15718 This is useful for local php development, but a security risk for public sites,
15719 as error messages can reveal passwords and personal data.
15720 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
15721 This file will log the @code{stderr} outputs of php worker processes.
15722 Can be set to @code{#f} to disable logging.
15723 @item @code{file} (default @code{#f})
15724 An optional override of the whole configuration.
15725 You can use the @code{mixed-text-file} function or an absolute filepath for it.
15729 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
15730 Data Type for the @code{dynamic} php-fpm process manager. With the
15731 @code{dynamic} process manager, spare worker processes are kept around
15732 based on it's configured limits.
15734 @item @code{max-children} (default: @code{5})
15735 Maximum of worker processes.
15736 @item @code{start-servers} (default: @code{2})
15737 How many worker processes should be started on start-up.
15738 @item @code{min-spare-servers} (default: @code{1})
15739 How many spare worker processes should be kept around at minimum.
15740 @item @code{max-spare-servers} (default: @code{3})
15741 How many spare worker processes should be kept around at maximum.
15745 @deftp {Data type} php-fpm-static-process-manager-configuration
15746 Data Type for the @code{static} php-fpm process manager. With the
15747 @code{static} process manager, an unchanging number of worker processes
15750 @item @code{max-children} (default: @code{5})
15751 Maximum of worker processes.
15755 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
15756 Data Type for the @code{on-demand} php-fpm process manager. With the
15757 @code{on-demand} process manager, worker processes are only created as
15760 @item @code{max-children} (default: @code{5})
15761 Maximum of worker processes.
15762 @item @code{process-idle-timeout} (default: @code{10})
15763 The time in seconds after which a process with no requests is killed.
15768 @deffn {Scheme Procedure} nginx-php-fpm-location @
15769 [#:nginx-package nginx] @
15770 [socket (string-append "/var/run/php" @
15771 (version-major (package-version php)) @
15773 A helper function to quickly add php to an @code{nginx-server-configuration}.
15776 A simple services setup for nginx with php can look like this:
15778 (services (cons* (dhcp-client-service)
15779 (service php-fpm-service-type)
15780 (service nginx-service-type
15781 (nginx-server-configuration
15782 (server-name '("example.com"))
15783 (root "/srv/http/")
15785 (list (nginx-php-location)))
15787 (ssl-certificate #f)
15788 (ssl-certificate-key #f)))
15792 @cindex cat-avatar-generator
15793 The cat avatar generator is a simple service to demonstrate the use of php-fpm
15794 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
15795 the hash of a user's email address.
15797 @deffn {Scheme Procedure} cat-avatar-generator-serice @
15798 [#:cache-dir "/var/cache/cat-avatar-generator"] @
15799 [#:package cat-avatar-generator] @
15800 [#:configuration (nginx-server-configuration)]
15801 Returns an nginx-server-configuration that inherits @code{configuration}. It
15802 extends the nginx configuration to add a server block that serves @code{package},
15803 a version of cat-avatar-generator. During execution, cat-avatar-generator will
15804 be able to use @code{cache-dir} as its cache directory.
15807 A simple setup for cat-avatar-generator can look like this:
15809 (services (cons* (cat-avatar-generator-service
15811 (nginx-server-configuration
15812 (server-name '("example.com"))))
15817 @node Certificate Services
15818 @subsubsection Certificate Services
15821 @cindex HTTP, HTTPS
15822 @cindex Let's Encrypt
15823 @cindex TLS certificates
15824 The @code{(gnu services certbot)} module provides a service to
15825 automatically obtain a valid TLS certificate from the Let's Encrypt
15826 certificate authority. These certificates can then be used to serve
15827 content securely over HTTPS or other TLS-based protocols, with the
15828 knowledge that the client will be able to verify the server's
15831 @url{https://letsencrypt.org/, Let's Encrypt} provides the
15832 @code{certbot} tool to automate the certification process. This tool
15833 first securely generates a key on the server. It then makes a request
15834 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
15835 checks that the request originates from the host in question by using a
15836 challenge-response protocol, requiring the server to provide its
15837 response over HTTP. If that protocol completes successfully, the CA
15838 signs the key, resulting in a certificate. That certificate is valid
15839 for a limited period of time, and therefore to continue to provide TLS
15840 services, the server needs to periodically ask the CA to renew its
15843 The certbot service automates this process: the initial key
15844 generation, the initial certification request to the Let's Encrypt
15845 service, the web server challenge/response integration, writing the
15846 certificate to disk, the automated periodic renewals, and the deployment
15847 tasks associated with the renewal (e.g. reloading services, copying keys
15848 with different permissions).
15850 Certbot is run twice a day, at a random minute within the hour. It
15851 won't do anything until your certificates are due for renewal or
15852 revoked, but running it regularly would give your service a chance of
15853 staying online in case a Let's Encrypt-initiated revocation happened for
15856 By using this service, you agree to the ACME Subscriber Agreement, which
15857 can be found there:
15858 @url{https://acme-v01.api.letsencrypt.org/directory}.
15860 @defvr {Scheme Variable} certbot-service-type
15861 A service type for the @code{certbot} Let's Encrypt client. Its value
15862 must be a @code{certbot-configuration} record as in this example:
15865 (define %nginx-deploy-hook
15867 "nginx-deploy-hook"
15868 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
15869 (kill pid SIGHUP))))
15871 (service certbot-service-type
15872 (certbot-configuration
15873 (email "foo@@example.net")
15876 (certificate-configuration
15877 (domains '("example.net" "www.example.net"))
15878 (deploy-hook %nginx-deploy-hook))
15879 (certificate-configuration
15880 (domains '("bar.example.net")))))))
15883 See below for details about @code{certbot-configuration}.
15886 @deftp {Data Type} certbot-configuration
15887 Data type representing the configuration of the @code{certbot} service.
15888 This type has the following parameters:
15891 @item @code{package} (default: @code{certbot})
15892 The certbot package to use.
15894 @item @code{webroot} (default: @code{/var/www})
15895 The directory from which to serve the Let's Encrypt challenge/response
15898 @item @code{certificates} (default: @code{()})
15899 A list of @code{certificates-configuration}s for which to generate
15900 certificates and request signatures. Each certificate has a @code{name}
15901 and several @code{domains}.
15904 Mandatory email used for registration, recovery contact, and important
15905 account notifications.
15907 @item @code{rsa-key-size} (default: @code{2048})
15908 Size of the RSA key.
15910 @item @code{default-location} (default: @i{see below})
15911 The default @code{nginx-location-configuration}. Because @code{certbot}
15912 needs to be able to serve challenges and responses, it needs to be able
15913 to run a web server. It does so by extending the @code{nginx} web
15914 service with an @code{nginx-server-configuration} listening on the
15915 @var{domains} on port 80, and which has a
15916 @code{nginx-location-configuration} for the @code{/.well-known/} URI
15917 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
15918 these nginx configuration data types.
15920 Requests to other URL paths will be matched by the
15921 @code{default-location}, which if present is added to all
15922 @code{nginx-server-configuration}s.
15924 By default, the @code{default-location} will issue a redirect from
15925 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
15926 you to define what to serve on your site via @code{https}.
15928 Pass @code{#f} to not issue a default location.
15932 @deftp {Data Type} certificate-configuration
15933 Data type representing the configuration of a certificate.
15934 This type has the following parameters:
15937 @item @code{name} (default: @i{see below})
15938 This name is used by Certbot for housekeeping and in file paths; it
15939 doesn't affect the content of the certificate itself. To see
15940 certificate names, run @code{certbot certificates}.
15942 Its default is the first provided domain.
15944 @item @code{domains} (default: @code{()})
15945 The first domain provided will be the subject CN of the certificate, and
15946 all domains will be Subject Alternative Names on the certificate.
15948 @item @code{deploy-hook} (default: @code{#f})
15949 Command to be run in a shell once for each successfully issued
15950 certificate. For this command, the shell variable
15951 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
15952 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
15953 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
15954 contain a space-delimited list of renewed certificate domains (for
15955 example, @samp{"example.com www.example.com"}.
15960 For each @code{certificate-configuration}, the certificate is saved to
15961 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
15962 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
15964 @subsubsection DNS Services
15965 @cindex DNS (domain name system)
15966 @cindex domain name system (DNS)
15968 The @code{(gnu services dns)} module provides services related to the
15969 @dfn{domain name system} (DNS). It provides a server service for hosting
15970 an @emph{authoritative} DNS server for multiple zones, slave or master.
15971 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}.
15973 An example configuration of an authoritative server for two zones, one master
15977 (define-zone-entries example.org.zone
15978 ;; Name TTL Class Type Data
15979 ("@@" "" "IN" "A" "127.0.0.1")
15980 ("@@" "" "IN" "NS" "ns")
15981 ("ns" "" "IN" "A" "127.0.0.1"))
15983 (define master-zone
15984 (knot-zone-configuration
15985 (domain "example.org")
15987 (origin "example.org")
15988 (entries example.org.zone)))))
15991 (knot-zone-configuration
15992 (domain "plop.org")
15993 (dnssec-policy "default")
15994 (master (list "plop-master"))))
15996 (define plop-master
15997 (knot-remote-configuration
15999 (address (list "208.76.58.171"))))
16003 (services (cons* (service knot-service-type
16004 (knot-configuration
16005 (remotes (list plop-master))
16006 (zones (list master-zone slave-zone))))
16011 @deffn {Scheme Variable} knot-service-type
16012 This is the type for the Knot DNS server.
16014 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
16015 zones, that is to say domain names you would buy from a registrar. This server
16016 is not a resolver, meaning that it can only resolve names for which it is
16017 authoritative. This server can be configured to serve zones as a master server
16018 or a slave server as a per-zone basis. Slave zones will get their data from
16019 masters, and will serve it as an authoritative server. From the point of view
16020 of a resolver, there is no difference between master and slave.
16022 The following data types are used to configure the Knot DNS server:
16025 @deftp {Data Type} knot-key-configuration
16026 Data type representing a key.
16027 This type has the following parameters:
16030 @item @code{id} (default: @code{""})
16031 An identifier for other configuration fields to refer to this key. IDs must
16032 be unique and must not be empty.
16034 @item @code{algorithm} (default: @code{#f})
16035 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
16036 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
16037 and @code{'hmac-sha512}.
16039 @item @code{secret} (default: @code{""})
16040 The secret key itself.
16045 @deftp {Data Type} knot-acl-configuration
16046 Data type representing an Access Control List (ACL) configuration.
16047 This type has the following parameters:
16050 @item @code{id} (default: @code{""})
16051 An identifier for ether configuration fields to refer to this key. IDs must be
16052 unique and must not be empty.
16054 @item @code{address} (default: @code{'()})
16055 An ordered list of IP addresses, network subnets, or network ranges represented
16056 with strings. The query must match one of them. Empty value means that
16057 address match is not required.
16059 @item @code{key} (default: @code{'()})
16060 An ordered list of references to keys represented with strings. The string
16061 must match a key ID defined in a @code{knot-key-configuration}. No key means
16062 that a key is not require to match that ACL.
16064 @item @code{action} (default: @code{'()})
16065 An ordered list of actions that are permitted or forbidden by this ACL. Possible
16066 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
16067 and @code{'update}.
16069 @item @code{deny?} (default: @code{#f})
16070 When true, the ACL defines restrictions. Listed actions are forbidden. When
16071 false, listed actions are allowed.
16076 @deftp {Data Type} zone-entry
16077 Data type represnting a record entry in a zone file.
16078 This type has the following parameters:
16081 @item @code{name} (default: @code{"@@"})
16082 The name of the record. @code{"@@"} refers to the origin of the zone. Names
16083 are relative to the origin of the zone. For example, in the @code{example.org}
16084 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
16085 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
16086 refers to @code{ns.example.org}.
16088 @item @code{ttl} (default: @code{""})
16089 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
16091 @item @code{class} (default: @code{"IN"})
16092 The class of the record. Knot currently supports only @code{"IN"} and
16093 partially @code{"CH"}.
16095 @item @code{type} (default: @code{"A"})
16096 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
16097 address), NS (Name Server) and MX (Mail eXchange). Many other types are
16100 @item @code{data} (default: @code{""})
16101 The data contained in the record. For instance an IP address associated with
16102 an A record, or a domain name associated with an NS record. Remember that
16103 domain names are relative to the origin unless they end with a dot.
16108 @deftp {Data Type} zone-file
16109 Data type representing the content of a zone file.
16110 This type has the following parameters:
16113 @item @code{entries} (default: @code{'()})
16114 The list of entries. The SOA record is taken care of, so you don't need to
16115 put it in the list of entries. This list should probably contain an entry
16116 for your primary authoritative DNS server. Other than using a list of entries
16117 directly, you can use @code{define-zone-entries} to define a object containing
16118 the list of entries more easily, that you can later pass to the @code{entries}
16119 field of the @code{zone-file}.
16121 @item @code{origin} (default: @code{""})
16122 The name of your zone. This parameter cannot be empty.
16124 @item @code{ns} (default: @code{"ns"})
16125 The domain of your primary authoritative DNS server. The name is relative to
16126 the origin, unless it ends with a dot. It is mandatory that this primary
16127 DNS server corresponds to an NS record in the zone and that it is associated
16128 to an IP address in the list of entries.
16130 @item @code{mail} (default: @code{"hostmaster"})
16131 An email address people can contact you at, as the owner of the zone. This
16132 is translated as @code{<mail>@@<origin>}.
16134 @item @code{serial} (default: @code{1})
16135 The serial number of the zone. As this is used to keep track of changes by
16136 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
16137 Always increment it when you make a change in your zone.
16139 @item @code{refresh} (default: @code{(* 2 24 3600)})
16140 The frequency at which slaves will do a zone transfer. This value is a number
16141 of seconds. It can be computed by multiplications or with
16142 @code{(string->duration)}.
16144 @item @code{retry} (default: @code{(* 15 60)})
16145 The period after which a slave will retry to contact its master when it fails
16146 to do so a first time.
16148 @item @code{expiry} (default: @code{(* 14 24 3600)})
16149 Default TTL of records. Existing records are considered correct for at most
16150 this amount of time. After this period, resolvers will invalidate their cache
16151 and check again that it still exists.
16153 @item @code{nx} (default: @code{3600})
16154 Default TTL of inexistant records. This delay is usually short because you want
16155 your new domains to reach everyone quickly.
16160 @deftp {Data Type} knot-remote-configuration
16161 Data type representing a remote configuration.
16162 This type has the following parameters:
16165 @item @code{id} (default: @code{""})
16166 An identifier for other configuration fields to refer to this remote. IDs must
16167 be unique and must not be empty.
16169 @item @code{address} (default: @code{'()})
16170 An ordered list of destination IP addresses. Addresses are tried in sequence.
16171 An optional port can be given with the @@ separator. For instance:
16172 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
16174 @item @code{via} (default: @code{'()})
16175 An ordered list of source IP addresses. An empty list will have Knot choose
16176 an appropriate source IP. An optional port can be given with the @@ separator.
16177 The default is to choose at random.
16179 @item @code{key} (default: @code{#f})
16180 A reference to a key, that is a string containing the identifier of a key
16181 defined in a @code{knot-key-configuration} field.
16186 @deftp {Data Type} knot-keystore-configuration
16187 Data type representing a keystore to hold dnssec keys.
16188 This type has the following parameters:
16191 @item @code{id} (default: @code{""})
16192 The id of the keystore. It must not be empty.
16194 @item @code{backend} (default: @code{'pem})
16195 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
16197 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
16198 The configuration string of the backend. An example for the PKCS#11 is:
16199 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
16200 For the pem backend, the string reprensents a path in the file system.
16205 @deftp {Data Type} knot-policy-configuration
16206 Data type representing a dnssec policy. Knot DNS is able to automatically
16207 sign your zones. It can either generate and manage your keys automatically or
16208 use keys that you generate.
16210 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
16211 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
16212 zone. In order to be trusted, the KSK needs to be present in the parent zone
16213 (usually a top-level domain). If your registrar supports dnssec, you will
16214 have to send them your KSK's hash so they can add a DS record in their zone.
16215 This is not automated and need to be done each time you change your KSK.
16217 The policy also defines the lifetime of keys. Usually, ZSK can be changed
16218 easily and use weaker cryptographic functions (they use lower parameters) in
16219 order to sign records quickly, so they are changed often. The KSK however
16220 requires manual interaction with the registrar, so they are changed less often
16221 and use stronger parameters because they sign only one record.
16223 This type has the following parameters:
16226 @item @code{id} (default: @code{""})
16227 The id of the policy. It must not be empty.
16229 @item @code{keystore} (default: @code{"default"})
16230 A reference to a keystore, that is a string containing the identifier of a
16231 keystore defined in a @code{knot-keystore-configuration} field. The
16232 @code{"default"} identifier means the default keystore (a kasp database that
16233 was setup by this service).
16235 @item @code{manual?} (default: @code{#f})
16236 Whether the key management is manual or automatic.
16238 @item @code{single-type-signing?} (default: @code{#f})
16239 When @code{#t}, use the Single-Type Signing Scheme.
16241 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
16242 An algorithm of signing keys and issued signatures.
16244 @item @code{ksk-size} (default: @code{256})
16245 The length of the KSK. Note that this value is correct for the default
16246 algorithm, but would be unsecure for other algorithms.
16248 @item @code{zsk-size} (default: @code{256})
16249 The length of the ZSK. Note that this value is correct for the default
16250 algorithm, but would be unsecure for other algorithms.
16252 @item @code{dnskey-ttl} (default: @code{'default})
16253 The TTL value for DNSKEY records added into zone apex. The special
16254 @code{'default} value means same as the zone SOA TTL.
16256 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
16257 The period between ZSK publication and the next rollover initiation.
16259 @item @code{propagation-delay} (default: @code{(* 24 3600)})
16260 An extra delay added for each key rollover step. This value should be high
16261 enough to cover propagation of data from the master server to all slaves.
16263 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
16264 A validity period of newly issued signatures.
16266 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
16267 A period how long before a signature expiration the signature will be refreshed.
16269 @item @code{nsec3?} (default: @code{#f})
16270 When @code{#t}, NSEC3 will be used instead of NSEC.
16272 @item @code{nsec3-iterations} (default: @code{5})
16273 The number of additional times the hashing is performed.
16275 @item @code{nsec3-salt-length} (default: @code{8})
16276 The length of a salt field in octets, which is appended to the original owner
16277 name before hashing.
16279 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
16280 The validity period of newly issued salt field.
16285 @deftp {Data Type} knot-zone-configuration
16286 Data type representing a zone served by Knot.
16287 This type has the following parameters:
16290 @item @code{domain} (default: @code{""})
16291 The domain served by this configuration. It must not be empty.
16293 @item @code{file} (default: @code{""})
16294 The file where this zone is saved. This parameter is ignored by master zones.
16295 Empty means default location that depends on the domain name.
16297 @item @code{zone} (default: @code{(zone-file)})
16298 The content of the zone file. This parameter is ignored by slave zones. It
16299 must contain a zone-file record.
16301 @item @code{master} (default: @code{'()})
16302 A list of master remotes. When empty, this zone is a master. When set, this
16303 zone is a slave. This is a list of remotes identifiers.
16305 @item @code{ddns-master} (default: @code{#f})
16306 The main master. When empty, it defaults to the first master in the list of
16309 @item @code{notify} (default: @code{'()})
16310 A list of slave remote identifiers.
16312 @item @code{acl} (default: @code{'()})
16313 A list of acl identifiers.
16315 @item @code{semantic-checks?} (default: @code{#f})
16316 When set, this adds more semantic checks to the zone.
16318 @item @code{disable-any?} (default: @code{#f})
16319 When set, this forbids queries of the ANY type.
16321 @item @code{zonefile-sync} (default: @code{0})
16322 The delay between a modification in memory and on disk. 0 means immediate
16325 @item @code{serial-policy} (default: @code{'increment})
16326 A policy between @code{'increment} and @code{'unixtime}.
16331 @deftp {Data Type} knot-configuration
16332 Data type representing the Knot configuration.
16333 This type has the following parameters:
16336 @item @code{knot} (default: @code{knot})
16339 @item @code{run-directory} (default: @code{"/var/run/knot"})
16340 The run directory. This directory will be used for pid file and sockets.
16342 @item @code{listen-v4} (default: @code{"0.0.0.0"})
16343 An ip address on which to listen.
16345 @item @code{listen-v6} (default: @code{"::"})
16346 An ip address on which to listen.
16348 @item @code{listen-port} (default: @code{53})
16349 A port on which to listen.
16351 @item @code{keys} (default: @code{'()})
16352 The list of knot-key-configuration used by this configuration.
16354 @item @code{acls} (default: @code{'()})
16355 The list of knot-acl-configuration used by this configuration.
16357 @item @code{remotes} (default: @code{'()})
16358 The list of knot-remote-configuration used by this configuration.
16360 @item @code{zones} (default: @code{'()})
16361 The list of knot-zone-configuration used by this configuration.
16368 @subsubsection VPN Services
16369 @cindex VPN (virtual private network)
16370 @cindex virtual private network (VPN)
16372 The @code{(gnu services vpn)} module provides services related to
16373 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
16374 your machine to connect to a VPN, and a @emph{servire} service for your machine
16375 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
16377 @deffn {Scheme Procedure} openvpn-client-service @
16378 [#:config (openvpn-client-configuration)]
16380 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
16383 @deffn {Scheme Procedure} openvpn-server-service @
16384 [#:config (openvpn-server-configuration)]
16386 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
16388 Both can be run simultaneously.
16391 @c %automatically generated documentation
16393 Available @code{openvpn-client-configuration} fields are:
16395 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
16396 The OpenVPN package.
16400 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
16401 The OpenVPN pid file.
16403 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
16407 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
16408 The protocol (UDP or TCP) used to open a channel between clients and
16411 Defaults to @samp{udp}.
16415 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
16416 The device type used to represent the VPN connection.
16418 Defaults to @samp{tun}.
16422 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
16423 The certificate authority to check connections against.
16425 Defaults to @samp{"/etc/openvpn/ca.crt"}.
16429 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
16430 The certificate of the machine the daemon is running on. It should be
16431 signed by the authority given in @code{ca}.
16433 Defaults to @samp{"/etc/openvpn/client.crt"}.
16437 @deftypevr {@code{openvpn-client-configuration} parameter} string key
16438 The key of the machine the daemon is running on. It must be the key whose
16439 certificate is @code{cert}.
16441 Defaults to @samp{"/etc/openvpn/client.key"}.
16445 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
16446 Whether to use the lzo compression algorithm.
16448 Defaults to @samp{#t}.
16452 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
16453 Don't re-read key files across SIGUSR1 or --ping-restart.
16455 Defaults to @samp{#t}.
16459 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
16460 Don't close and reopen TUN/TAP device or run up/down scripts across
16461 SIGUSR1 or --ping-restart restarts.
16463 Defaults to @samp{#t}.
16467 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
16470 Defaults to @samp{3}.
16474 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
16475 Add an additional layer of HMAC authentication on top of the TLS control
16476 channel to protect against DoS attacks.
16478 Defaults to @samp{#f}.
16482 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
16483 Whether to check the server certificate has server usage extension.
16485 Defaults to @samp{#t}.
16489 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
16490 Bind to a specific local port number.
16492 Defaults to @samp{#f}.
16496 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
16497 Retry resolving server address.
16499 Defaults to @samp{#t}.
16503 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
16504 A list of remote servers to connect to.
16506 Defaults to @samp{()}.
16508 Available @code{openvpn-remote-configuration} fields are:
16510 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
16513 Defaults to @samp{"my-server"}.
16517 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
16518 Port number the server listens to.
16520 Defaults to @samp{1194}.
16525 @c %end of automatic openvpn-client documentation
16527 @c %automatically generated documentation
16529 Available @code{openvpn-server-configuration} fields are:
16531 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
16532 The OpenVPN package.
16536 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
16537 The OpenVPN pid file.
16539 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
16543 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
16544 The protocol (UDP or TCP) used to open a channel between clients and
16547 Defaults to @samp{udp}.
16551 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
16552 The device type used to represent the VPN connection.
16554 Defaults to @samp{tun}.
16558 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
16559 The certificate authority to check connections against.
16561 Defaults to @samp{"/etc/openvpn/ca.crt"}.
16565 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
16566 The certificate of the machine the daemon is running on. It should be
16567 signed by the authority given in @code{ca}.
16569 Defaults to @samp{"/etc/openvpn/client.crt"}.
16573 @deftypevr {@code{openvpn-server-configuration} parameter} string key
16574 The key of the machine the daemon is running on. It must be the key whose
16575 certificate is @code{cert}.
16577 Defaults to @samp{"/etc/openvpn/client.key"}.
16581 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
16582 Whether to use the lzo compression algorithm.
16584 Defaults to @samp{#t}.
16588 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
16589 Don't re-read key files across SIGUSR1 or --ping-restart.
16591 Defaults to @samp{#t}.
16595 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
16596 Don't close and reopen TUN/TAP device or run up/down scripts across
16597 SIGUSR1 or --ping-restart restarts.
16599 Defaults to @samp{#t}.
16603 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
16606 Defaults to @samp{3}.
16610 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
16611 Add an additional layer of HMAC authentication on top of the TLS control
16612 channel to protect against DoS attacks.
16614 Defaults to @samp{#f}.
16618 @deftypevr {@code{openvpn-server-configuration} parameter} number port
16619 Specifies the port number on which the server listens.
16621 Defaults to @samp{1194}.
16625 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
16626 An ip and mask specifying the subnet inside the virtual network.
16628 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
16632 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
16633 A CIDR notation specifying the IPv6 subnet inside the virtual network.
16635 Defaults to @samp{#f}.
16639 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
16640 The Diffie-Hellman parameters file.
16642 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
16646 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
16647 The file that records client IPs.
16649 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
16653 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
16654 When true, the server will act as a gateway for its clients.
16656 Defaults to @samp{#f}.
16660 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
16661 When true, clients are allowed to talk to each other inside the VPN.
16663 Defaults to @samp{#f}.
16667 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
16668 Causes ping-like messages to be sent back and forth over the link so
16669 that each side knows when the other side has gone down. @code{keepalive}
16670 requires a pair. The first element is the period of the ping sending,
16671 and the second element is the timeout before considering the other side
16676 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
16677 The maximum number of clients.
16679 Defaults to @samp{100}.
16683 @deftypevr {@code{openvpn-server-configuration} parameter} string status
16684 The status file. This file shows a small report on current connection.
16685 It is truncated and rewritten every minute.
16687 Defaults to @samp{"/var/run/openvpn/status"}.
16691 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
16692 The list of configuration for some clients.
16694 Defaults to @samp{()}.
16696 Available @code{openvpn-ccd-configuration} fields are:
16698 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
16701 Defaults to @samp{"client"}.
16705 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
16708 Defaults to @samp{#f}.
16712 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
16715 Defaults to @samp{#f}.
16722 @c %end of automatic openvpn-server documentation
16725 @node Network File System
16726 @subsubsection Network File System
16729 The @code{(gnu services nfs)} module provides the following services,
16730 which are most commonly used in relation to mounting or exporting
16731 directory trees as @dfn{network file systems} (NFS).
16733 @subsubheading RPC Bind Service
16736 The RPC Bind service provides a facility to map program numbers into
16737 universal addresses.
16738 Many NFS related services use this facility. Hence it is automatically
16739 started when a dependent service starts.
16741 @defvr {Scheme Variable} rpcbind-service-type
16742 A service type for the RPC portmapper daemon.
16746 @deftp {Data Type} rpcbind-configuration
16747 Data type representing the configuration of the RPC Bind Service.
16748 This type has the following parameters:
16750 @item @code{rpcbind} (default: @code{rpcbind})
16751 The rpcbind package to use.
16753 @item @code{warm-start?} (default: @code{#t})
16754 If this parameter is @code{#t}, then the daemon will read a
16755 state file on startup thus reloading state information saved by a previous
16761 @subsubheading Pipefs Pseudo File System
16765 The pipefs file system is used to transfer NFS related data
16766 between the kernel and user space programs.
16768 @defvr {Scheme Variable} pipefs-service-type
16769 A service type for the pipefs pseudo file system.
16772 @deftp {Data Type} pipefs-configuration
16773 Data type representing the configuration of the pipefs pseudo file system service.
16774 This type has the following parameters:
16776 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
16777 The directory to which the file system is to be attached.
16782 @subsubheading GSS Daemon Service
16785 @cindex global security system
16787 The @dfn{global security system} (GSS) daemon provides strong security for RPC
16789 Before exchanging RPC requests an RPC client must establish a security
16790 context. Typically this is done using the Kerberos command @command{kinit}
16791 or automatically at login time using PAM services (@pxref{Kerberos Services}).
16793 @defvr {Scheme Variable} gss-service-type
16794 A service type for the Global Security System (GSS) daemon.
16797 @deftp {Data Type} gss-configuration
16798 Data type representing the configuration of the GSS daemon service.
16799 This type has the following parameters:
16801 @item @code{nfs-utils} (default: @code{nfs-utils})
16802 The package in which the @command{rpc.gssd} command is to be found.
16804 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
16805 The directory where the pipefs file system is mounted.
16811 @subsubheading IDMAP Daemon Service
16813 @cindex name mapper
16815 The idmap daemon service provides mapping between user IDs and user names.
16816 Typically it is required in order to access file systems mounted via NFSv4.
16818 @defvr {Scheme Variable} idmap-service-type
16819 A service type for the Identity Mapper (IDMAP) daemon.
16822 @deftp {Data Type} idmap-configuration
16823 Data type representing the configuration of the IDMAP daemon service.
16824 This type has the following parameters:
16826 @item @code{nfs-utils} (default: @code{nfs-utils})
16827 The package in which the @command{rpc.idmapd} command is to be found.
16829 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
16830 The directory where the pipefs file system is mounted.
16832 @item @code{domain} (default: @code{#f})
16833 The local NFSv4 domain name.
16834 This must be a string or @code{#f}.
16835 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
16840 @node Continuous Integration
16841 @subsubsection Continuous Integration
16843 @cindex continuous integration
16844 @uref{https://notabug.org/mthl/cuirass, Cuirass} is a continuous
16845 integration tool for Guix. It can be used both for development and for
16846 providing substitutes to others (@pxref{Substitutes}).
16848 The @code{(gnu services cuirass)} module provides the following service.
16850 @defvr {Scheme Procedure} cuirass-service-type
16851 The type of the Cuirass service. Its value must be a
16852 @code{cuirass-configuration} object, as described below.
16855 To add build jobs, you have to set the @code{specifications} field of
16856 the configuration. Here is an example of a service defining a build job
16857 based on a specification that can be found in Cuirass source tree. This
16858 service polls the Guix repository and builds a subset of the Guix
16859 packages, as prescribed in the @file{gnu-system.scm} example spec:
16862 (let ((spec #~((#:name . "guix")
16863 (#:url . "git://git.savannah.gnu.org/guix.git")
16864 (#:load-path . ".")
16865 (#:file . "build-aux/cuirass/gnu-system.scm")
16866 (#:proc . cuirass-jobs)
16867 (#:arguments (subset . "hello"))
16868 (#:branch . "master"))))
16869 (service cuirass-service-type
16870 (cuirass-configuration
16871 (specifications #~(list '#$spec)))))
16874 While information related to build jobs is located directly in the
16875 specifications, global settings for the @command{cuirass} process are
16876 accessible in other @code{cuirass-configuration} fields.
16878 @deftp {Data Type} cuirass-configuration
16879 Data type representing the configuration of Cuirass.
16882 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
16883 Location of the log file.
16885 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
16886 Location of the repository cache.
16888 @item @code{user} (default: @code{"cuirass"})
16889 Owner of the @code{cuirass} process.
16891 @item @code{group} (default: @code{"cuirass"})
16892 Owner's group of the @code{cuirass} process.
16894 @item @code{interval} (default: @code{60})
16895 Number of seconds between the poll of the repositories followed by the
16898 @item @code{database} (default: @code{"/var/run/cuirass/cuirass.db"})
16899 Location of sqlite database which contains the build results and previously
16900 added specifications.
16902 @item @code{port} (default: @code{8081})
16903 Port number used by the HTTP server.
16905 @item --listen=@var{host}
16906 Listen on the network interface for @var{host}. The default is to
16907 accept connections from localhost.
16909 @item @code{specifications} (default: @code{#~'()})
16910 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
16911 where a specification is an association list
16912 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
16913 keys are keywords (@code{#:keyword-example}) as shown in the example
16916 @item @code{use-substitutes?} (default: @code{#f})
16917 This allows using substitutes to avoid building every dependencies of a job
16920 @item @code{one-shot?} (default: @code{#f})
16921 Only evaluate specifications and build derivations once.
16923 @item @code{fallback?} (default: @code{#f})
16924 When substituting a pre-built binary fails, fall back to building
16927 @item @code{load-path} (default: @code{'()})
16928 This allows users to define their own packages and make them visible to
16929 cuirass as in @command{guix build} command.
16931 @item @code{cuirass} (default: @code{cuirass})
16932 The Cuirass package to use.
16936 @node Power management Services
16937 @subsubsection Power management Services
16939 @cindex power management with TLP
16940 The @code{(gnu services pm)} module provides a Guix service definition
16941 for the Linux power management tool TLP.
16943 TLP enables various powersaving modes in userspace and kernel.
16944 Contrary to @code{upower-service}, it is not a passive,
16945 monitoring tool, as it will apply custom settings each time a new power
16946 source is detected. More information can be found at
16947 @uref{http://linrunner.de/en/tlp/tlp.html, TLP home page}.
16949 @deffn {Scheme Variable} tlp-service-type
16950 The service type for the TLP tool. Its value should be a valid
16951 TLP configuration (see below). To use the default settings, simply
16954 (service tlp-service-type)
16958 By default TLP does not need much configuration but most TLP parameters
16959 can be tweaked using @code{tlp-configuration}.
16961 Each parameter definition is preceded by its type; for example,
16962 @samp{boolean foo} indicates that the @code{foo} parameter
16963 should be specified as a boolean. Types starting with
16964 @code{maybe-} denote parameters that won't show up in TLP config file
16965 when their value is @code{'disabled}.
16967 @c The following documentation was initially generated by
16968 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
16969 @c documentation is better, so we shouldn't hesitate to edit below as
16970 @c needed. However if the change you want to make to this documentation
16971 @c can be done in an automated way, it's probably easier to change
16972 @c (generate-documentation) than to make it below and have to deal with
16973 @c the churn as TLP updates.
16975 Available @code{tlp-configuration} fields are:
16977 @deftypevr {@code{tlp-configuration} parameter} package tlp
16982 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
16983 Set to true if you wish to enable TLP.
16985 Defaults to @samp{#t}.
16989 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
16990 Default mode when no power supply can be detected. Alternatives are AC
16993 Defaults to @samp{"AC"}.
16997 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
16998 Number of seconds Linux kernel has to wait after the disk goes idle,
16999 before syncing on AC.
17001 Defaults to @samp{0}.
17005 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
17006 Same as @code{disk-idle-ac} but on BAT mode.
17008 Defaults to @samp{2}.
17012 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
17013 Dirty pages flushing periodicity, expressed in seconds.
17015 Defaults to @samp{15}.
17019 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
17020 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
17022 Defaults to @samp{60}.
17026 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
17027 CPU frequency scaling governor on AC mode. With intel_pstate driver,
17028 alternatives are powersave and performance. With acpi-cpufreq driver,
17029 alternatives are ondemand, powersave, performance and conservative.
17031 Defaults to @samp{disabled}.
17035 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
17036 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
17038 Defaults to @samp{disabled}.
17042 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
17043 Set the min available frequency for the scaling governor on AC.
17045 Defaults to @samp{disabled}.
17049 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
17050 Set the max available frequency for the scaling governor on AC.
17052 Defaults to @samp{disabled}.
17056 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
17057 Set the min available frequency for the scaling governor on BAT.
17059 Defaults to @samp{disabled}.
17063 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
17064 Set the max available frequency for the scaling governor on BAT.
17066 Defaults to @samp{disabled}.
17070 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
17071 Limit the min P-state to control the power dissipation of the CPU, in AC
17072 mode. Values are stated as a percentage of the available performance.
17074 Defaults to @samp{disabled}.
17078 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
17079 Limit the max P-state to control the power dissipation of the CPU, in AC
17080 mode. Values are stated as a percentage of the available performance.
17082 Defaults to @samp{disabled}.
17086 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
17087 Same as @code{cpu-min-perf-on-ac} on BAT mode.
17089 Defaults to @samp{disabled}.
17093 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
17094 Same as @code{cpu-max-perf-on-ac} on BAT mode.
17096 Defaults to @samp{disabled}.
17100 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
17101 Enable CPU turbo boost feature on AC mode.
17103 Defaults to @samp{disabled}.
17107 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
17108 Same as @code{cpu-boost-on-ac?} on BAT mode.
17110 Defaults to @samp{disabled}.
17114 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
17115 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
17116 used under light load conditions.
17118 Defaults to @samp{#f}.
17122 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
17123 Same as @code{sched-powersave-on-ac?} but on BAT mode.
17125 Defaults to @samp{#t}.
17129 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
17130 Enable Linux kernel NMI watchdog.
17132 Defaults to @samp{#f}.
17136 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
17137 For Linux kernels with PHC patch applied, change CPU voltages. An
17138 example value would be @samp{"F:V F:V F:V F:V"}.
17140 Defaults to @samp{disabled}.
17144 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
17145 Set CPU performance versus energy saving policy on AC. Alternatives are
17146 performance, normal, powersave.
17148 Defaults to @samp{"performance"}.
17152 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
17153 Same as @code{energy-perf-policy-ac} but on BAT mode.
17155 Defaults to @samp{"powersave"}.
17159 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
17164 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
17165 Hard disk advanced power management level.
17169 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
17170 Same as @code{disk-apm-bat} but on BAT mode.
17174 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
17175 Hard disk spin down timeout. One value has to be specified for each
17176 declared hard disk.
17178 Defaults to @samp{disabled}.
17182 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
17183 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
17185 Defaults to @samp{disabled}.
17189 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
17190 Select IO scheduler for disk devices. One value has to be specified for
17191 each declared hard disk. Example alternatives are cfq, deadline and
17194 Defaults to @samp{disabled}.
17198 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
17199 SATA aggressive link power management (ALPM) level. Alternatives are
17200 min_power, medium_power, max_performance.
17202 Defaults to @samp{"max_performance"}.
17206 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
17207 Same as @code{sata-linkpwr-ac} but on BAT mode.
17209 Defaults to @samp{"min_power"}.
17213 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
17214 Exclude specified SATA host devices for link power management.
17216 Defaults to @samp{disabled}.
17220 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
17221 Enable Runtime Power Management for AHCI controller and disks on AC
17224 Defaults to @samp{disabled}.
17228 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
17229 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
17231 Defaults to @samp{disabled}.
17235 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
17236 Seconds of inactivity before disk is suspended.
17238 Defaults to @samp{15}.
17242 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
17243 PCI Express Active State Power Management level. Alternatives are
17244 default, performance, powersave.
17246 Defaults to @samp{"performance"}.
17250 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
17251 Same as @code{pcie-aspm-ac} but on BAT mode.
17253 Defaults to @samp{"powersave"}.
17257 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
17258 Radeon graphics clock speed level. Alternatives are low, mid, high,
17261 Defaults to @samp{"high"}.
17265 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
17266 Same as @code{radeon-power-ac} but on BAT mode.
17268 Defaults to @samp{"low"}.
17272 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
17273 Radeon dynamic power management method (DPM). Alternatives are battery,
17276 Defaults to @samp{"performance"}.
17280 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
17281 Same as @code{radeon-dpm-state-ac} but on BAT mode.
17283 Defaults to @samp{"battery"}.
17287 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
17288 Radeon DPM performance level. Alternatives are auto, low, high.
17290 Defaults to @samp{"auto"}.
17294 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
17295 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
17297 Defaults to @samp{"auto"}.
17301 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
17302 Wifi power saving mode.
17304 Defaults to @samp{#f}.
17308 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
17309 Same as @code{wifi-power-ac?} but on BAT mode.
17311 Defaults to @samp{#t}.
17315 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
17316 Disable wake on LAN.
17318 Defaults to @samp{#t}.
17322 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
17323 Timeout duration in seconds before activating audio power saving on
17324 Intel HDA and AC97 devices. A value of 0 disables power saving.
17326 Defaults to @samp{0}.
17330 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
17331 Same as @code{sound-powersave-ac} but on BAT mode.
17333 Defaults to @samp{1}.
17337 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
17338 Disable controller in powersaving mode on Intel HDA devices.
17340 Defaults to @samp{#t}.
17344 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
17345 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
17346 powered on again by releasing (and reinserting) the eject lever or by
17347 pressing the disc eject button on newer models.
17349 Defaults to @samp{#f}.
17353 @deftypevr {@code{tlp-configuration} parameter} string bay-device
17354 Name of the optical drive device to power off.
17356 Defaults to @samp{"sr0"}.
17360 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
17361 Runtime Power Management for PCI(e) bus devices. Alternatives are on
17364 Defaults to @samp{"on"}.
17368 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
17369 Same as @code{runtime-pm-ac} but on BAT mode.
17371 Defaults to @samp{"auto"}.
17375 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
17376 Runtime Power Management for all PCI(e) bus devices, except blacklisted
17379 Defaults to @samp{#t}.
17383 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
17384 Exclude specified PCI(e) device addresses from Runtime Power Management.
17386 Defaults to @samp{disabled}.
17390 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
17391 Exclude PCI(e) devices assigned to the specified drivers from Runtime
17396 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
17397 Enable USB autosuspend feature.
17399 Defaults to @samp{#t}.
17403 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
17404 Exclude specified devices from USB autosuspend.
17406 Defaults to @samp{disabled}.
17410 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
17411 Exclude WWAN devices from USB autosuspend.
17413 Defaults to @samp{#t}.
17417 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
17418 Include specified devices into USB autosuspend, even if they are already
17419 excluded by the driver or via @code{usb-blacklist-wwan?}.
17421 Defaults to @samp{disabled}.
17425 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
17426 Enable USB autosuspend before shutdown.
17428 Defaults to @samp{disabled}.
17432 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
17433 Restore radio device state (bluetooth, wifi, wwan) from previous
17434 shutdown on system startup.
17436 Defaults to @samp{#f}.
17441 The @code{(gnu services pm)} module provides an interface to
17442 thermald, a CPU frequency scaling service which helps prevent overheating.
17444 @defvr {Scheme Variable} thermald-service-type
17445 This is the service type for
17446 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
17447 Thermal Daemon, which is responsible for controlling the thermal state
17448 of processors and preventing overheating.
17451 @deftp {Data Type} thermald-configuration
17452 Data type representing the configuration of @code{thermald-service-type}.
17455 @item @code{ignore-cpuid-check?} (default: @code{#f})
17456 Ignore cpuid check for supported CPU models.
17458 @item @code{thermald} (default: @var{thermald})
17459 Package object of thermald.
17464 @node Audio Services
17465 @subsubsection Audio Services
17467 The @code{(gnu services audio)} module provides a service to start MPD
17468 (the Music Player Daemon).
17471 @subsubheading Music Player Daemon
17473 The Music Player Daemon (MPD) is a service that can play music while
17474 being controlled from the local machine or over the network by a variety
17477 The following example shows how one might run @code{mpd} as user
17478 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
17481 (service mpd-service-type
17487 @defvr {Scheme Variable} mpd-service-type
17488 The service type for @command{mpd}
17491 @deftp {Data Type} mpd-configuration
17492 Data type representing the configuration of @command{mpd}.
17495 @item @code{user} (default: @code{"mpd"})
17496 The user to run mpd as.
17498 @item @code{music-dir} (default: @code{"~/Music"})
17499 The directory to scan for music files.
17501 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
17502 The directory to store playlists.
17504 @item @code{port} (default: @code{"6600"})
17505 The port to run mpd on.
17507 @item @code{address} (default: @code{"any"})
17508 The address that mpd will bind to. To use a Unix domain socket,
17509 an absolute path can be specified here.
17514 @node Virtualization Services
17515 @subsubsection Virtualization services
17517 The @code{(gnu services virtualization)} module provides services for
17518 the libvirt and virtlog daemons, as well as other virtualization-related
17521 @subsubheading Libvirt daemon
17522 @code{libvirtd} is the server side daemon component of the libvirt
17523 virtualization management system. This daemon runs on host servers
17524 and performs required management tasks for virtualized guests.
17526 @deffn {Scheme Variable} libvirt-service-type
17527 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
17528 Its value must be a @code{libvirt-configuration}.
17531 (service libvirt-service-type
17532 (libvirt-configuration
17533 (unix-sock-group "libvirt")
17534 (tls-port "16555")))
17538 @c Auto-generated with (generate-libvirt-documentation)
17539 Available @code{libvirt-configuration} fields are:
17541 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
17546 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
17547 Flag listening for secure TLS connections on the public TCP/IP port.
17548 must set @code{listen} for this to have any effect.
17550 It is necessary to setup a CA and issue server certificates before using
17553 Defaults to @samp{#t}.
17557 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
17558 Listen for unencrypted TCP connections on the public TCP/IP port. must
17559 set @code{listen} for this to have any effect.
17561 Using the TCP socket requires SASL authentication by default. Only SASL
17562 mechanisms which support data encryption are allowed. This is
17563 DIGEST_MD5 and GSSAPI (Kerberos5)
17565 Defaults to @samp{#f}.
17569 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
17570 Port for accepting secure TLS connections This can be a port number, or
17573 Defaults to @samp{"16514"}.
17577 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
17578 Port for accepting insecure TCP connections This can be a port number,
17581 Defaults to @samp{"16509"}.
17585 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
17586 IP address or hostname used for client connections.
17588 Defaults to @samp{"0.0.0.0"}.
17592 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
17593 Flag toggling mDNS advertisement of the libvirt service.
17595 Alternatively can disable for all services on a host by stopping the
17598 Defaults to @samp{#f}.
17602 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
17603 Default mDNS advertisement name. This must be unique on the immediate
17606 Defaults to @samp{"Virtualization Host <hostname>"}.
17610 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
17611 UNIX domain socket group ownership. This can be used to allow a
17612 'trusted' set of users access to management capabilities without
17615 Defaults to @samp{"root"}.
17619 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
17620 UNIX socket permissions for the R/O socket. This is used for monitoring
17623 Defaults to @samp{"0777"}.
17627 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
17628 UNIX socket permissions for the R/W socket. Default allows only root.
17629 If PolicyKit is enabled on the socket, the default will change to allow
17630 everyone (eg, 0777)
17632 Defaults to @samp{"0770"}.
17636 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
17637 UNIX socket permissions for the admin socket. Default allows only owner
17638 (root), do not change it unless you are sure to whom you are exposing
17641 Defaults to @samp{"0777"}.
17645 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
17646 The directory in which sockets will be found/created.
17648 Defaults to @samp{"/var/run/libvirt"}.
17652 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
17653 Authentication scheme for UNIX read-only sockets. By default socket
17654 permissions allow anyone to connect
17656 Defaults to @samp{"polkit"}.
17660 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
17661 Authentication scheme for UNIX read-write sockets. By default socket
17662 permissions only allow root. If PolicyKit support was compiled into
17663 libvirt, the default will be to use 'polkit' auth.
17665 Defaults to @samp{"polkit"}.
17669 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
17670 Authentication scheme for TCP sockets. If you don't enable SASL, then
17671 all TCP traffic is cleartext. Don't do this outside of a dev/test
17674 Defaults to @samp{"sasl"}.
17678 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
17679 Authentication scheme for TLS sockets. TLS sockets already have
17680 encryption provided by the TLS layer, and limited authentication is done
17683 It is possible to make use of any SASL authentication mechanism as well,
17684 by using 'sasl' for this option
17686 Defaults to @samp{"none"}.
17690 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
17691 API access control scheme.
17693 By default an authenticated user is allowed access to all APIs. Access
17694 drivers can place restrictions on this.
17696 Defaults to @samp{()}.
17700 @deftypevr {@code{libvirt-configuration} parameter} string key-file
17701 Server key file path. If set to an empty string, then no private key is
17704 Defaults to @samp{""}.
17708 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
17709 Server key file path. If set to an empty string, then no certificate is
17712 Defaults to @samp{""}.
17716 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
17717 Server key file path. If set to an empty string, then no CA certificate
17720 Defaults to @samp{""}.
17724 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
17725 Certificate revocation list path. If set to an empty string, then no
17728 Defaults to @samp{""}.
17732 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
17733 Disable verification of our own server certificates.
17735 When libvirtd starts it performs some sanity checks against its own
17738 Defaults to @samp{#f}.
17742 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
17743 Disable verification of client certificates.
17745 Client certificate verification is the primary authentication mechanism.
17746 Any client which does not present a certificate signed by the CA will be
17749 Defaults to @samp{#f}.
17753 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
17754 Whitelist of allowed x509 Distinguished Name.
17756 Defaults to @samp{()}.
17760 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
17761 Whitelist of allowed SASL usernames. The format for username depends on
17762 the SASL authentication mechanism.
17764 Defaults to @samp{()}.
17768 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
17769 Override the compile time default TLS priority string. The default is
17770 usually "NORMAL" unless overridden at build time. Only set this is it
17771 is desired for libvirt to deviate from the global default settings.
17773 Defaults to @samp{"NORMAL"}.
17777 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
17778 Maximum number of concurrent client connections to allow over all
17781 Defaults to @samp{5000}.
17785 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
17786 Maximum length of queue of connections waiting to be accepted by the
17787 daemon. Note, that some protocols supporting retransmission may obey
17788 this so that a later reattempt at connection succeeds.
17790 Defaults to @samp{1000}.
17794 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
17795 Maximum length of queue of accepted but not yet authenticated clients.
17796 Set this to zero to turn this feature off
17798 Defaults to @samp{20}.
17802 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
17803 Number of workers to start up initially.
17805 Defaults to @samp{5}.
17809 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
17810 Maximum number of worker threads.
17812 If the number of active clients exceeds @code{min-workers}, then more
17813 threads are spawned, up to max_workers limit. Typically you'd want
17814 max_workers to equal maximum number of clients allowed.
17816 Defaults to @samp{20}.
17820 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
17821 Number of priority workers. If all workers from above pool are stuck,
17822 some calls marked as high priority (notably domainDestroy) can be
17823 executed in this pool.
17825 Defaults to @samp{5}.
17829 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
17830 Total global limit on concurrent RPC calls.
17832 Defaults to @samp{20}.
17836 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
17837 Limit on concurrent requests from a single client connection. To avoid
17838 one client monopolizing the server this should be a small fraction of
17839 the global max_requests and max_workers parameter.
17841 Defaults to @samp{5}.
17845 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
17846 Same as @code{min-workers} but for the admin interface.
17848 Defaults to @samp{1}.
17852 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
17853 Same as @code{max-workers} but for the admin interface.
17855 Defaults to @samp{5}.
17859 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
17860 Same as @code{max-clients} but for the admin interface.
17862 Defaults to @samp{5}.
17866 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
17867 Same as @code{max-queued-clients} but for the admin interface.
17869 Defaults to @samp{5}.
17873 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
17874 Same as @code{max-client-requests} but for the admin interface.
17876 Defaults to @samp{5}.
17880 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
17881 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
17883 Defaults to @samp{3}.
17887 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
17890 A filter allows to select a different logging level for a given category
17891 of logs The format for a filter is one of:
17902 where @code{name} is a string which is matched against the category
17903 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
17904 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
17905 be a substring of the full category name, in order to match multiple
17906 similar categories), the optional "+" prefix tells libvirt to log stack
17907 trace for each message matching name, and @code{x} is the minimal level
17908 where matching messages should be logged:
17925 Multiple filters can be defined in a single filters statement, they just
17926 need to be separated by spaces.
17928 Defaults to @samp{"3:remote 4:event"}.
17932 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
17935 An output is one of the places to save logging information The format
17936 for an output can be:
17940 output goes to stderr
17942 @item x:syslog:name
17943 use syslog for the output and use the given name as the ident
17945 @item x:file:file_path
17946 output to a file, with the given filepath
17949 output to journald logging system
17953 In all case the x prefix is the minimal level, acting as a filter
17970 Multiple outputs can be defined, they just need to be separated by
17973 Defaults to @samp{"3:stderr"}.
17977 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
17978 Allows usage of the auditing subsystem to be altered
17982 0: disable all auditing
17985 1: enable auditing, only if enabled on host
17988 2: enable auditing, and exit if disabled on host.
17992 Defaults to @samp{1}.
17996 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
17997 Send audit messages via libvirt logging infrastructure.
17999 Defaults to @samp{#f}.
18003 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
18004 Host UUID. UUID must not have all digits be the same.
18006 Defaults to @samp{""}.
18010 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
18011 Source to read host UUID.
18015 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
18018 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
18022 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
18025 Defaults to @samp{"smbios"}.
18029 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
18030 A keepalive message is sent to a client after @code{keepalive_interval}
18031 seconds of inactivity to check if the client is still responding. If
18032 set to -1, libvirtd will never send keepalive requests; however clients
18033 can still send them and the daemon will send responses.
18035 Defaults to @samp{5}.
18039 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
18040 Maximum number of keepalive messages that are allowed to be sent to the
18041 client without getting any response before the connection is considered
18044 In other words, the connection is automatically closed approximately
18045 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
18046 the last message received from the client. When @code{keepalive-count}
18047 is set to 0, connections will be automatically closed after
18048 @code{keepalive-interval} seconds of inactivity without sending any
18049 keepalive messages.
18051 Defaults to @samp{5}.
18055 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
18056 Same as above but for admin interface.
18058 Defaults to @samp{5}.
18062 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
18063 Same as above but for admin interface.
18065 Defaults to @samp{5}.
18069 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
18070 Timeout for Open vSwitch calls.
18072 The @code{ovs-vsctl} utility is used for the configuration and its
18073 timeout option is set by default to 5 seconds to avoid potential
18074 infinite waits blocking libvirt.
18076 Defaults to @samp{5}.
18080 @c %end of autogenerated docs
18082 @subsubheading Virtlog daemon
18083 The virtlogd service is a server side daemon component of libvirt that is
18084 used to manage logs from virtual machine consoles.
18086 This daemon is not used directly by libvirt client applications, rather it
18087 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
18088 standalone daemon, the main @code{libvirtd} daemon can be restarted without
18089 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
18090 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
18092 @deffn {Scheme Variable} virtlog-service-type
18093 This is the type of the virtlog daemon.
18094 Its value must be a @code{virtlog-configuration}.
18097 (service virtlog-service-type
18098 (virtlog-configuration
18099 (max-clients 1000)))
18103 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
18104 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
18106 Defaults to @samp{3}.
18110 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
18113 A filter allows to select a different logging level for a given category
18114 of logs The format for a filter is one of:
18125 where @code{name} is a string which is matched against the category
18126 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
18127 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
18128 be a substring of the full category name, in order to match multiple
18129 similar categories), the optional "+" prefix tells libvirt to log stack
18130 trace for each message matching name, and @code{x} is the minimal level
18131 where matching messages should be logged:
18148 Multiple filters can be defined in a single filters statement, they just
18149 need to be separated by spaces.
18151 Defaults to @samp{"3:remote 4:event"}.
18155 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
18158 An output is one of the places to save logging information The format
18159 for an output can be:
18163 output goes to stderr
18165 @item x:syslog:name
18166 use syslog for the output and use the given name as the ident
18168 @item x:file:file_path
18169 output to a file, with the given filepath
18172 output to journald logging system
18176 In all case the x prefix is the minimal level, acting as a filter
18193 Multiple outputs can be defined, they just need to be separated by
18196 Defaults to @samp{"3:stderr"}.
18200 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
18201 Maximum number of concurrent client connections to allow over all
18204 Defaults to @samp{1024}.
18208 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
18209 Maximum file size before rolling over.
18211 Defaults to @samp{2MB}
18215 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
18216 Maximum number of backup files to keep.
18218 Defaults to @samp{3}
18222 @subsubheading Transparent Emulation with QEMU
18225 @cindex @code{binfmt_misc}
18226 @code{qemu-binfmt-service-type} provides support for transparent
18227 emulation of program binaries built for different architectures---e.g.,
18228 it allows you to transparently execute an ARMv7 program on an x86_64
18229 machine. It achieves this by combining the @uref{https://www.qemu.org,
18230 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
18232 @defvr {Scheme Variable} qemu-binfmt-service-type
18233 This is the type of the QEMU/binfmt service for transparent emulation.
18234 Its value must be a @code{qemu-binfmt-configuration} object, which
18235 specifies the QEMU package to use as well as the architecture we want to
18239 (service qemu-binfmt-service-type
18240 (qemu-binfmt-configuration
18241 (platforms (lookup-qemu-platforms "arm" "aarch64" "ppc"))))
18244 In this example, we enable transparent emulation for the ARM and aarch64
18245 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
18246 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
18247 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
18250 @deftp {Data Type} qemu-binfmt-configuration
18251 This is the configuration for the @code{qemu-binfmt} service.
18254 @item @code{platforms} (default: @code{'()})
18255 The list of emulated QEMU platforms. Each item must be a @dfn{platform
18256 object} as returned by @code{lookup-qemu-platforms} (see below).
18258 @item @code{guix-support?} (default: @code{#f})
18259 When it is true, QEMU and all its dependencies are added to the build
18260 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
18261 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
18262 handlers to be used within the build environment, which in turn means
18263 that you can transparently build programs for another architecture.
18265 For example, let's suppose you're on an x86_64 machine and you have this
18269 (service qemu-binfmt-service-type
18270 (qemu-binfmt-configuration
18271 (platforms (lookup-qemu-platforms "arm"))
18272 (guix-support? #t)))
18278 guix build -s armhf-linux inkscape
18282 and it will build Inkscape for ARMv7 @emph{as if it were a native
18283 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
18284 if you'd like to test a package build for an architecture you don't have
18287 @item @code{qemu} (default: @code{qemu})
18288 The QEMU package to use.
18292 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
18293 Return the list of QEMU platform objects corresponding to
18294 @var{platforms}@dots{}. @var{platforms} must be a list of strings
18295 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
18296 @code{"mips64el"}, and so on.
18299 @deffn {Scheme Procedure} qemu-platform? @var{obj}
18300 Return true if @var{obj} is a platform object.
18303 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
18304 Return the name of @var{platform}---a string such as @code{"arm"}.
18307 @node Version Control Services
18308 @subsubsection Version Control Services
18310 The @code{(gnu services version-control)} module provides a service to
18311 allow remote access to local Git repositories. There are two options:
18312 the @code{git-daemon-service}, which provides access to repositories via
18313 the @code{git://} unsecured TCP-based protocol, or extending the
18314 @code{nginx} web server to proxy some requests to
18315 @code{git-http-backend}.
18317 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
18319 Return a service that runs @command{git daemon}, a simple TCP server to
18320 expose repositories over the Git protocol for anonymous access.
18322 The optional @var{config} argument should be a
18323 @code{<git-daemon-configuration>} object, by default it allows read-only
18324 access to exported@footnote{By creating the magic file
18325 "git-daemon-export-ok" in the repository directory.} repositories under
18330 @deftp {Data Type} git-daemon-configuration
18331 Data type representing the configuration for @code{git-daemon-service}.
18334 @item @code{package} (default: @var{git})
18335 Package object of the Git distributed version control system.
18337 @item @code{export-all?} (default: @var{#f})
18338 Whether to allow access for all Git repositories, even if they do not
18339 have the @file{git-daemon-export-ok} file.
18341 @item @code{base-path} (default: @file{/srv/git})
18342 Whether to remap all the path requests as relative to the given path.
18343 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
18344 then if you later try to pull @code{git://example.com/hello.git}, git
18345 daemon will interpret the path as @code{/srv/git/hello.git}.
18347 @item @code{user-path} (default: @var{#f})
18348 Whether to allow @code{~user} notation to be used in requests. When
18349 specified with empty string, requests to @code{git://host/~alice/foo} is
18350 taken as a request to access @code{foo} repository in the home directory
18351 of user @code{alice}. If @var{(user-path "path")} is specified, the
18352 same request is taken as a request to access @code{path/foo} repository
18353 in the home directory of user @code{alice}.
18355 @item @code{listen} (default: @var{'()})
18356 Whether to listen on specific IP addresses or hostnames, defaults to
18359 @item @code{port} (default: @var{#f})
18360 Whether to listen on an alternative port, which defaults to 9418.
18362 @item @code{whitelist} (default: @var{'()})
18363 If not empty, only allow access to this list of directories.
18365 @item @code{extra-options} (default: @var{'()})
18366 Extra options will be passed to @code{git daemon}, please run
18367 @command{man git-daemon} for more information.
18372 The @code{git://} protocol lacks authentication. When you pull from a
18373 repository fetched via @code{git://}, you don't know that the data you
18374 receive was modified is really coming from the specified host, and you
18375 have your connection is subject to eavesdropping. It's better to use an
18376 authenticated and encrypted transport, such as @code{https}. Although Git allows you
18377 to serve repositories using unsophisticated file-based web servers,
18378 there is a faster protocol implemented by the @code{git-http-backend}
18379 program. This program is the back-end of a proper Git web service. It
18380 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
18381 on running the necessary @code{fcgiwrap} daemon.
18383 Guix has a separate configuration data type for serving Git repositories
18386 @deftp {Data Type} git-http-configuration
18387 Data type representing the configuration for @code{git-http-service}.
18390 @item @code{package} (default: @var{git})
18391 Package object of the Git distributed version control system.
18393 @item @code{git-root} (default: @file{/srv/git})
18394 Directory containing the Git repositories to expose to the world.
18396 @item @code{export-all?} (default: @var{#f})
18397 Whether to expose access for all Git repositories in @var{git-root},
18398 even if they do not have the @file{git-daemon-export-ok} file.
18400 @item @code{uri-path} (default: @file{/git/})
18401 Path prefix for Git access. With the default @code{/git/} prefix, this
18402 will map @code{http://@var{server}/git/@var{repo}.git} to
18403 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
18404 with this prefix are not passed on to this Git instance.
18406 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
18407 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
18412 There is no @code{git-http-service-type}, currently; instead you can
18413 create an @code{nginx-location-configuration} from a
18414 @code{git-http-configuration} and then add that location to a web
18417 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
18418 [config=(git-http-configuration)]
18419 Compute an @code{nginx-location-configuration} that corresponds to the
18420 given Git http configuration. An example nginx service definition to
18421 serve the default @file{/srv/git} over HTTPS might be:
18424 (service nginx-service-type
18425 (nginx-configuration
18428 (nginx-server-configuration
18429 (listen '("443 ssl"))
18430 (server-name "git.my-host.org")
18432 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
18433 (ssl-certificate-key
18434 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
18437 (git-http-nginx-location-configuration
18438 (git-http-configuration (uri-path "/"))))))))))
18441 This example assumes that you are using Let's Encrypt to get your TLS
18442 certificate. @xref{Certificate Services}. The default @code{certbot}
18443 service will redirect all HTTP traffic on @code{git.my-host.org} to
18444 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
18445 system services. @xref{Web Services}.
18448 @node Game Services
18449 @subsubsection Game Services
18451 @subsubheading The Battle for Wesnoth Service
18453 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
18454 based tactical strategy game, with several single player campaigns, and
18455 multiplayer games (both networked and local).
18457 @defvar {Scheme Variable} wesnothd-service-type
18458 Service type for the wesnothd service. Its value must be a
18459 @code{wesnothd-configuration} object. To run wesnothd in the default
18460 configuration, instantiate it as:
18463 (service wesnothd-service-type)
18467 @deftp {Data Type} wesnothd-configuration
18468 Data type representing the configuration of @command{wesnothd}.
18471 @item @code{package} (default: @code{wesnoth-server})
18472 The wesnoth server package to use.
18474 @item @code{port} (default: @code{15000})
18475 The port to bind the server to.
18479 @node Miscellaneous Services
18480 @subsubsection Miscellaneous Services
18483 @subsubheading System Control Service
18485 The @code{(gnu services sysctl)} provides a service to configure kernel
18486 parameters at boot.
18488 @defvr {Scheme Variable} sysctl-service-type
18489 The service type for @command{sysctl}, which modifies kernel parameters
18490 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
18494 (service sysctl-service-type
18495 (sysctl-configuration
18496 (settings '(("net.ipv4.ip_forward" . "1")))))
18500 @deftp {Data Type} sysctl-configuration
18501 The data type representing the configuration of @command{sysctl}.
18504 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
18505 The @command{sysctl} executable to use.
18507 @item @code{settings} (default: @code{'()})
18508 An association list specifies kernel parameters and their values.
18513 @subsubheading Lirc Service
18515 The @code{(gnu services lirc)} module provides the following service.
18517 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
18518 [#:device #f] [#:driver #f] [#:config-file #f] @
18519 [#:extra-options '()]
18520 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
18521 decodes infrared signals from remote controls.
18523 Optionally, @var{device}, @var{driver} and @var{config-file}
18524 (configuration file name) may be specified. See @command{lircd} manual
18527 Finally, @var{extra-options} is a list of additional command-line options
18528 passed to @command{lircd}.
18532 @subsubheading Spice Service
18534 The @code{(gnu services spice)} module provides the following service.
18536 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
18537 Returns a service that runs @url{http://www.spice-space.org,VDAGENT}, a daemon
18538 that enables sharing the clipboard with a vm and setting the guest display
18539 resolution when the graphical console window resizes.
18542 @subsubsection Dictionary Services
18544 The @code{(gnu services dict)} module provides the following service:
18546 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
18547 Return a service that runs the @command{dicod} daemon, an implementation
18548 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
18550 The optional @var{config} argument specifies the configuration for
18551 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
18552 default it serves the GNU Collaborative International Dictonary of English.
18554 You can add @command{open localhost} to your @file{~/.dico} file to make
18555 @code{localhost} the default server for @command{dico} client
18556 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
18559 @deftp {Data Type} dicod-configuration
18560 Data type representing the configuration of dicod.
18563 @item @code{dico} (default: @var{dico})
18564 Package object of the GNU Dico dictionary server.
18566 @item @code{interfaces} (default: @var{'("localhost")})
18567 This is the list of IP addresses and ports and possibly socket file
18568 names to listen to (@pxref{Server Settings, @code{listen} directive,,
18569 dico, GNU Dico Manual}).
18571 @item @code{handlers} (default: @var{'()})
18572 List of @code{<dicod-handler>} objects denoting handlers (module instances).
18574 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
18575 List of @code{<dicod-database>} objects denoting dictionaries to be served.
18579 @deftp {Data Type} dicod-handler
18580 Data type representing a dictionary handler (module instance).
18584 Name of the handler (module instance).
18586 @item @code{module} (default: @var{#f})
18587 Name of the dicod module of the handler (instance). If it is @code{#f},
18588 the module has the same name as the handler.
18589 (@pxref{Modules,,, dico, GNU Dico Manual}).
18591 @item @code{options}
18592 List of strings or gexps representing the arguments for the module handler
18596 @deftp {Data Type} dicod-database
18597 Data type representing a dictionary database.
18601 Name of the database, will be used in DICT commands.
18603 @item @code{handler}
18604 Name of the dicod handler (module instance) used by this database
18605 (@pxref{Handlers,,, dico, GNU Dico Manual}).
18607 @item @code{complex?} (default: @var{#f})
18608 Whether the database configuration complex. The complex configuration
18609 will need a corresponding @code{<dicod-handler>} object, otherwise not.
18611 @item @code{options}
18612 List of strings or gexps representing the arguments for the database
18613 (@pxref{Databases,,, dico, GNU Dico Manual}).
18617 @defvr {Scheme Variable} %dicod-database:gcide
18618 A @code{<dicod-database>} object serving the GNU Collaborative International
18619 Dictionary of English using the @code{gcide} package.
18622 The following is an example @code{dicod-service} configuration.
18625 (dicod-service #:config
18626 (dicod-configuration
18627 (handlers (list (dicod-handler
18631 (list #~(string-append "dbdir=" #$wordnet))))))
18632 (databases (list (dicod-database
18635 (handler "wordnet")
18636 (options '("database=wn")))
18637 %dicod-database:gcide))))
18641 @subsubheading Cgit Service
18643 @cindex Cgit service
18644 @cindex Git, web interface
18645 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
18646 repositories written in C.
18648 The following example will configure the service with default values.
18649 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
18652 (service cgit-service-type)
18655 @c %start of fragment
18657 Available @code{cgit-configuration} fields are:
18659 @deftypevr {@code{cgit-configuration} parameter} package package
18664 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
18665 NGINX configuration.
18669 @deftypevr {@code{cgit-configuration} parameter} string about-filter
18670 Specifies a command which will be invoked to format the content of about
18671 pages (both top-level and for each repository).
18673 Defaults to @samp{""}.
18677 @deftypevr {@code{cgit-configuration} parameter} string agefile
18678 Specifies a path, relative to each repository path, which can be used to
18679 specify the date and time of the youngest commit in the repository.
18681 Defaults to @samp{""}.
18685 @deftypevr {@code{cgit-configuration} parameter} string auth-filter
18686 Specifies a command that will be invoked for authenticating repository
18689 Defaults to @samp{""}.
18693 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
18694 Flag which, when set to @samp{age}, enables date ordering in the branch
18695 ref list, and when set @samp{name} enables ordering by branch name.
18697 Defaults to @samp{"name"}.
18701 @deftypevr {@code{cgit-configuration} parameter} string cache-root
18702 Path used to store the cgit cache entries.
18704 Defaults to @samp{"/var/cache/cgit"}.
18708 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
18709 Number which specifies the time-to-live, in minutes, for the cached
18710 version of repository pages accessed with a fixed SHA1.
18712 Defaults to @samp{-1}.
18716 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
18717 Number which specifies the time-to-live, in minutes, for the cached
18718 version of repository pages accessed without a fixed SHA1.
18720 Defaults to @samp{5}.
18724 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
18725 Number which specifies the time-to-live, in minutes, for the cached
18726 version of the repository summary page.
18728 Defaults to @samp{5}.
18732 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
18733 Number which specifies the time-to-live, in minutes, for the cached
18734 version of the repository index page.
18736 Defaults to @samp{5}.
18740 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
18741 Number which specifies the time-to-live, in minutes, for the result of
18742 scanning a path for Git repositories.
18744 Defaults to @samp{15}.
18748 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
18749 Number which specifies the time-to-live, in minutes, for the cached
18750 version of the repository about page.
18752 Defaults to @samp{15}.
18756 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
18757 Number which specifies the time-to-live, in minutes, for the cached
18758 version of snapshots.
18760 Defaults to @samp{5}.
18764 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
18765 The maximum number of entries in the cgit cache. When set to @samp{0},
18766 caching is disabled.
18768 Defaults to @samp{0}.
18772 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
18773 Sort items in the repo list case sensitively.
18775 Defaults to @samp{#t}.
18779 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
18780 List of common prefixes which, when combined with a repository URL,
18781 generates valid clone URLs for the repository.
18783 Defaults to @samp{()}.
18787 @deftypevr {@code{cgit-configuration} parameter} list clone-url
18788 List of @code{clone-url} templates.
18790 Defaults to @samp{()}.
18794 @deftypevr {@code{cgit-configuration} parameter} string commit-filter
18795 Command which will be invoked to format commit messages.
18797 Defaults to @samp{""}.
18801 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
18802 Flag which, when set to @samp{date}, enables strict date ordering in the
18803 commit log, and when set to @samp{topo} enables strict topological
18806 Defaults to @samp{"git log"}.
18810 @deftypevr {@code{cgit-configuration} parameter} string css
18811 URL which specifies the css document to include in all cgit pages.
18813 Defaults to @samp{"/share/cgit/cgit.css"}.
18817 @deftypevr {@code{cgit-configuration} parameter} string email-filter
18818 Specifies a command which will be invoked to format names and email
18819 address of committers, authors, and taggers, as represented in various
18820 places throughout the cgit interface.
18822 Defaults to @samp{""}.
18826 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
18827 Flag which, when set to @samp{#t}, will make cgit generate a HTML
18828 fragment suitable for embedding in other HTML pages.
18830 Defaults to @samp{#f}.
18834 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
18835 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
18836 commit history graph to the left of the commit messages in the
18837 repository log page.
18839 Defaults to @samp{#f}.
18843 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
18844 Flag which, when set to @samp{#t}, allows all filter settings to be
18845 overridden in repository-specific cgitrc files.
18847 Defaults to @samp{#f}.
18851 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
18852 Flag which, when set to @samp{#t}, allows users to follow a file in the
18855 Defaults to @samp{#f}.
18859 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
18860 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
18863 Defaults to @samp{#t}.
18867 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
18868 Flag which, when set to @samp{#t}, will make cgit generate extra links
18869 "summary", "commit", "tree" for each repo in the repository index.
18871 Defaults to @samp{#f}.
18875 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
18876 Flag which, when set to @samp{#t}, will make cgit display the owner of
18877 each repo in the repository index.
18879 Defaults to @samp{#t}.
18883 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
18884 Flag which, when set to @samp{#t}, will make cgit print the number of
18885 modified files for each commit on the repository log page.
18887 Defaults to @samp{#f}.
18891 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
18892 Flag which, when set to @samp{#t}, will make cgit print the number of
18893 added and removed lines for each commit on the repository log page.
18895 Defaults to @samp{#f}.
18899 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
18900 Flag which, when set to @code{#t}, will make cgit display remote
18901 branches in the summary and refs views.
18903 Defaults to @samp{#f}.
18907 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
18908 Flag which, when set to @code{1}, will make cgit use the subject of the
18909 parent commit as link text when generating links to parent commits in
18912 Defaults to @samp{#f}.
18916 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
18917 Flag which, when set to @samp{#t}, will make cgit use the subject of the
18918 parent commit as link text when generating links to parent commits in
18921 Defaults to @samp{#f}.
18925 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
18926 Flag which, when set to @samp{#t}, will make cgit generate linenumber
18927 links for plaintext blobs printed in the tree view.
18929 Defaults to @samp{#t}.
18933 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
18934 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
18935 set any repo specific settings.
18937 Defaults to @samp{#f}.
18941 @deftypevr {@code{cgit-configuration} parameter} string favicon
18942 URL used as link to a shortcut icon for cgit.
18944 Defaults to @samp{"/favicon.ico"}.
18948 @deftypevr {@code{cgit-configuration} parameter} string footer
18949 The content of the file specified with this option will be included
18950 verbatim at the bottom of all pages (i.e. it replaces the standard
18951 "generated by..." message).
18953 Defaults to @samp{""}.
18957 @deftypevr {@code{cgit-configuration} parameter} string head-include
18958 The content of the file specified with this option will be included
18959 verbatim in the HTML HEAD section on all pages.
18961 Defaults to @samp{""}.
18965 @deftypevr {@code{cgit-configuration} parameter} string header
18966 The content of the file specified with this option will be included
18967 verbatim at the top of all pages.
18969 Defaults to @samp{""}.
18973 @deftypevr {@code{cgit-configuration} parameter} string include
18974 Name of a configfile to include before the rest of the current config-
18977 Defaults to @samp{""}.
18981 @deftypevr {@code{cgit-configuration} parameter} string index-header
18982 The content of the file specified with this option will be included
18983 verbatim above the repository index.
18985 Defaults to @samp{""}.
18989 @deftypevr {@code{cgit-configuration} parameter} string index-info
18990 The content of the file specified with this option will be included
18991 verbatim below the heading on the repository index page.
18993 Defaults to @samp{""}.
18997 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
18998 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
18999 in the servers timezone.
19001 Defaults to @samp{#f}.
19005 @deftypevr {@code{cgit-configuration} parameter} string logo
19006 URL which specifies the source of an image which will be used as a logo
19009 Defaults to @samp{"/share/cgit/cgit.png"}.
19013 @deftypevr {@code{cgit-configuration} parameter} string logo-link
19014 URL loaded when clicking on the cgit logo image.
19016 Defaults to @samp{""}.
19020 @deftypevr {@code{cgit-configuration} parameter} string owner-filter
19021 Command which will be invoked to format the Owner column of the main
19024 Defaults to @samp{""}.
19028 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
19029 Number of items to display in atom feeds view.
19031 Defaults to @samp{10}.
19035 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
19036 Number of entries to list per page in "log" view.
19038 Defaults to @samp{50}.
19042 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
19043 Number of commit message characters to display in "log" view.
19045 Defaults to @samp{80}.
19049 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
19050 Specifies the number of entries to list per page on the repository index
19053 Defaults to @samp{50}.
19057 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
19058 Specifies the maximum number of repo description characters to display
19059 on the repository index page.
19061 Defaults to @samp{80}.
19065 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
19066 Specifies the maximum size of a blob to display HTML for in KBytes.
19068 Defaults to @samp{0}.
19072 @deftypevr {@code{cgit-configuration} parameter} string max-stats
19073 Maximum statistics period. Valid values are @samp{week},@samp{month},
19074 @samp{quarter} and @samp{year}.
19076 Defaults to @samp{""}.
19080 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
19081 Mimetype for the specified filename extension.
19083 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
19084 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
19085 "image/png") (svg "image/svg+xml"))}.
19089 @deftypevr {@code{cgit-configuration} parameter} string mimetype-file
19090 Specifies the file to use for automatic mimetype lookup.
19092 Defaults to @samp{""}.
19096 @deftypevr {@code{cgit-configuration} parameter} string module-link
19097 Text which will be used as the formatstring for a hyperlink when a
19098 submodule is printed in a directory listing.
19100 Defaults to @samp{""}.
19104 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
19105 If set to the value @samp{#t} caching will be disabled.
19107 Defaults to @samp{#f}.
19111 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
19112 If set to @samp{#t} showing full author email addresses will be
19115 Defaults to @samp{#f}.
19119 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
19120 Flag which, when set to @samp{#t}, will make cgit omit the standard
19121 header on all pages.
19123 Defaults to @samp{#f}.
19127 @deftypevr {@code{cgit-configuration} parameter} string readme
19128 Text which will be used as default value for @code{cgit-repo-readme}.
19130 Defaults to @samp{""}.
19134 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
19135 If set to @code{#t} and @code{repository-directory} is enabled, if any
19136 repositories are found with a suffix of @code{.git}, this suffix will be
19137 removed for the URL and name.
19139 Defaults to @samp{#f}.
19143 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
19144 Maximum number of files to consider when detecting renames.
19146 Defaults to @samp{-1}.
19150 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
19151 The way in which repositories in each section are sorted.
19153 Defaults to @samp{""}.
19157 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
19158 Text used as content for the @code{robots} meta-tag.
19160 Defaults to @samp{("noindex" "nofollow")}.
19164 @deftypevr {@code{cgit-configuration} parameter} string root-desc
19165 Text printed below the heading on the repository index page.
19167 Defaults to @samp{"a fast webinterface for the git dscm"}.
19171 @deftypevr {@code{cgit-configuration} parameter} string root-readme
19172 The content of the file specified with this option will be included
19173 verbatim below thef "about" link on the repository index page.
19175 Defaults to @samp{""}.
19179 @deftypevr {@code{cgit-configuration} parameter} string root-title
19180 Text printed as heading on the repository index page.
19182 Defaults to @samp{""}.
19186 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
19187 If set to @samp{#t} and repository-directory is enabled,
19188 repository-directory will recurse into directories whose name starts
19189 with a period. Otherwise, repository-directory will stay away from such
19190 directories, considered as "hidden". Note that this does not apply to
19191 the ".git" directory in non-bare repos.
19193 Defaults to @samp{#f}.
19197 @deftypevr {@code{cgit-configuration} parameter} list snapshots
19198 Text which specifies the default set of snapshot formats that cgit
19199 generates links for.
19201 Defaults to @samp{()}.
19205 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
19206 Name of the directory to scan for repositories (represents
19209 Defaults to @samp{"/srv/git"}.
19213 @deftypevr {@code{cgit-configuration} parameter} string section
19214 The name of the current repository section - all repositories defined
19215 after this option will inherit the current section name.
19217 Defaults to @samp{""}.
19221 @deftypevr {@code{cgit-configuration} parameter} string section-sort
19222 Flag which, when set to @samp{1}, will sort the sections on the
19223 repository listing by name.
19225 Defaults to @samp{""}.
19229 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
19230 A number which, if defined prior to repository-directory, specifies how
19231 many path elements from each repo path to use as a default section name.
19233 Defaults to @samp{0}.
19237 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
19238 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
19241 Defaults to @samp{#f}.
19245 @deftypevr {@code{cgit-configuration} parameter} string source-filter
19246 Specifies a command which will be invoked to format plaintext blobs in
19249 Defaults to @samp{""}.
19253 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
19254 Specifies the number of branches to display in the repository "summary"
19257 Defaults to @samp{10}.
19261 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
19262 Specifies the number of log entries to display in the repository
19265 Defaults to @samp{10}.
19269 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
19270 Specifies the number of tags to display in the repository "summary"
19273 Defaults to @samp{10}.
19277 @deftypevr {@code{cgit-configuration} parameter} string strict-export
19278 Filename which, if specified, needs to be present within the repository
19279 for cgit to allow access to that repository.
19281 Defaults to @samp{""}.
19285 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
19286 URL which, if specified, will be used as root for all cgit links.
19288 Defaults to @samp{"/"}.
19292 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
19293 A list of @dfn{cgit-repo} records to use with config.
19295 Defaults to @samp{()}.
19297 Available @code{repository-cgit-configuration} fields are:
19299 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
19300 A mask of snapshot formats for this repo that cgit generates links for,
19301 restricted by the global @code{snapshots} setting.
19303 Defaults to @samp{()}.
19307 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string source-filter
19308 Override the default @code{source-filter}.
19310 Defaults to @samp{""}.
19314 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
19315 The relative URL used to access the repository.
19317 Defaults to @samp{""}.
19321 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string about-filter
19322 Override the default @code{about-filter}.
19324 Defaults to @samp{""}.
19328 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
19329 Flag which, when set to @samp{age}, enables date ordering in the branch
19330 ref list, and when set to @samp{name} enables ordering by branch name.
19332 Defaults to @samp{""}.
19336 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
19337 A list of URLs which can be used to clone repo.
19339 Defaults to @samp{()}.
19343 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-filter
19344 Override the default @code{commit-filter}.
19346 Defaults to @samp{""}.
19350 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
19351 Flag which, when set to @samp{date}, enables strict date ordering in the
19352 commit log, and when set to @samp{topo} enables strict topological
19355 Defaults to @samp{""}.
19359 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
19360 The name of the default branch for this repository. If no such branch
19361 exists in the repository, the first branch name (when sorted) is used as
19362 default instead. By default branch pointed to by HEAD, or "master" if
19363 there is no suitable HEAD.
19365 Defaults to @samp{""}.
19369 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
19370 The value to show as repository description.
19372 Defaults to @samp{""}.
19376 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
19377 The value to show as repository homepage.
19379 Defaults to @samp{""}.
19383 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string email-filter
19384 Override the default @code{email-filter}.
19386 Defaults to @samp{""}.
19390 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-commit-graph?
19391 A flag which can be used to disable the global setting
19392 @code{enable-commit-graph?}.
19394 Defaults to @samp{#f}.
19398 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-log-filecount?
19399 A flag which can be used to disable the global setting
19400 @code{enable-log-filecount?}.
19402 Defaults to @samp{#f}.
19406 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-log-linecount?
19407 A flag which can be used to disable the global setting
19408 @code{enable-log-linecount?}.
19410 Defaults to @samp{#f}.
19414 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-remote-branches?
19415 Flag which, when set to @code{#t}, will make cgit display remote
19416 branches in the summary and refs views.
19418 Defaults to @samp{#f}.
19422 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-subject-links?
19423 A flag which can be used to override the global setting
19424 @code{enable-subject-links?}.
19426 Defaults to @samp{#f}.
19430 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-html-serving?
19431 A flag which can be used to override the global setting
19432 @code{enable-html-serving?}.
19434 Defaults to @samp{#f}.
19438 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
19439 Flag which, when set to @code{#t}, hides the repository from the
19442 Defaults to @samp{#f}.
19446 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
19447 Flag which, when set to @samp{#t}, ignores the repository.
19449 Defaults to @samp{#f}.
19453 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo
19454 URL which specifies the source of an image which will be used as a logo
19455 on this repo’s pages.
19457 Defaults to @samp{""}.
19461 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
19462 URL loaded when clicking on the cgit logo image.
19464 Defaults to @samp{""}.
19468 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner-filter
19469 Override the default @code{owner-filter}.
19471 Defaults to @samp{""}.
19475 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
19476 Text which will be used as the formatstring for a hyperlink when a
19477 submodule is printed in a directory listing. The arguments for the
19478 formatstring are the path and SHA1 of the submodule commit.
19480 Defaults to @samp{""}.
19484 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
19485 Text which will be used as the formatstring for a hyperlink when a
19486 submodule with the specified subdirectory path is printed in a directory
19489 Defaults to @samp{()}.
19493 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
19494 Override the default maximum statistics period.
19496 Defaults to @samp{""}.
19500 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
19501 The value to show as repository name.
19503 Defaults to @samp{""}.
19507 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
19508 A value used to identify the owner of the repository.
19510 Defaults to @samp{""}.
19514 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
19515 An absolute path to the repository directory.
19517 Defaults to @samp{""}.
19521 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
19522 A path (relative to repo) which specifies a file to include verbatim as
19523 the "About" page for this repo.
19525 Defaults to @samp{""}.
19529 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
19530 The name of the current repository section - all repositories defined
19531 after this option will inherit the current section name.
19533 Defaults to @samp{""}.
19537 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
19538 Extra options will be appended to cgitrc file.
19540 Defaults to @samp{()}.
19546 @deftypevr {@code{cgit-configuration} parameter} list extra-options
19547 Extra options will be appended to cgitrc file.
19549 Defaults to @samp{()}.
19553 @c %end of fragment
19555 However, it could be that you just want to get a @code{cgitrc} up and
19556 running. In that case, you can pass an @code{opaque-cgit-configuration}
19557 as a record to @code{cgit-service-type}. As its name indicates, an
19558 opaque configuration does not have easy reflective capabilities.
19560 Available @code{opaque-cgit-configuration} fields are:
19562 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
19566 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
19567 The contents of the @code{cgitrc}, as a string.
19570 For example, if your @code{cgitrc} is just the empty string, you
19571 could instantiate a cgit service like this:
19574 (service cgit-service-type
19575 (opaque-cgit-configuration
19579 @node Setuid Programs
19580 @subsection Setuid Programs
19582 @cindex setuid programs
19583 Some programs need to run with ``root'' privileges, even when they are
19584 launched by unprivileged users. A notorious example is the
19585 @command{passwd} program, which users can run to change their
19586 password, and which needs to access the @file{/etc/passwd} and
19587 @file{/etc/shadow} files---something normally restricted to root, for
19588 obvious security reasons. To address that, these executables are
19589 @dfn{setuid-root}, meaning that they always run with root privileges
19590 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
19591 for more info about the setuid mechanism.)
19593 The store itself @emph{cannot} contain setuid programs: that would be a
19594 security issue since any user on the system can write derivations that
19595 populate the store (@pxref{The Store}). Thus, a different mechanism is
19596 used: instead of changing the setuid bit directly on files that are in
19597 the store, we let the system administrator @emph{declare} which programs
19598 should be setuid root.
19600 The @code{setuid-programs} field of an @code{operating-system}
19601 declaration contains a list of G-expressions denoting the names of
19602 programs to be setuid-root (@pxref{Using the Configuration System}).
19603 For instance, the @command{passwd} program, which is part of the Shadow
19604 package, can be designated by this G-expression (@pxref{G-Expressions}):
19607 #~(string-append #$shadow "/bin/passwd")
19610 A default set of setuid programs is defined by the
19611 @code{%setuid-programs} variable of the @code{(gnu system)} module.
19613 @defvr {Scheme Variable} %setuid-programs
19614 A list of G-expressions denoting common programs that are setuid-root.
19616 The list includes commands such as @command{passwd}, @command{ping},
19617 @command{su}, and @command{sudo}.
19620 Under the hood, the actual setuid programs are created in the
19621 @file{/run/setuid-programs} directory at system activation time. The
19622 files in this directory refer to the ``real'' binaries, which are in the
19625 @node X.509 Certificates
19626 @subsection X.509 Certificates
19628 @cindex HTTPS, certificates
19629 @cindex X.509 certificates
19631 Web servers available over HTTPS (that is, HTTP over the transport-layer
19632 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
19633 that the client can then use to @emph{authenticate} the server. To do
19634 that, clients verify that the server's certificate is signed by a
19635 so-called @dfn{certificate authority} (CA). But to verify the CA's
19636 signature, clients must have first acquired the CA's certificate.
19638 Web browsers such as GNU@tie{}IceCat include their own set of CA
19639 certificates, such that they are able to verify CA signatures
19642 However, most other programs that can talk HTTPS---@command{wget},
19643 @command{git}, @command{w3m}, etc.---need to be told where CA
19644 certificates can be found.
19646 @cindex @code{nss-certs}
19647 In GuixSD, this is done by adding a package that provides certificates
19648 to the @code{packages} field of the @code{operating-system} declaration
19649 (@pxref{operating-system Reference}). GuixSD includes one such package,
19650 @code{nss-certs}, which is a set of CA certificates provided as part of
19651 Mozilla's Network Security Services.
19653 Note that it is @emph{not} part of @var{%base-packages}, so you need to
19654 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
19655 most applications and libraries look for certificates by default, points
19656 to the certificates installed globally.
19658 Unprivileged users, including users of Guix on a foreign distro,
19659 can also install their own certificate package in
19660 their profile. A number of environment variables need to be defined so
19661 that applications and libraries know where to find them. Namely, the
19662 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
19663 variables. Some applications add their own environment variables; for
19664 instance, the Git version control system honors the certificate bundle
19665 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
19666 would typically run something like:
19669 $ guix package -i nss-certs
19670 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
19671 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
19672 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
19675 As another example, R requires the @code{CURL_CA_BUNDLE} environment
19676 variable to point to a certificate bundle, so you would have to run
19677 something like this:
19680 $ guix package -i nss-certs
19681 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
19684 For other applications you may want to look up the required environment
19685 variable in the relevant documentation.
19688 @node Name Service Switch
19689 @subsection Name Service Switch
19691 @cindex name service switch
19693 The @code{(gnu system nss)} module provides bindings to the
19694 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
19695 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
19696 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
19697 extended with new ``name'' lookup methods for system databases, which
19698 includes host names, service names, user accounts, and more (@pxref{Name
19699 Service Switch, System Databases and Name Service Switch,, libc, The GNU
19700 C Library Reference Manual}).
19702 The NSS configuration specifies, for each system database, which lookup
19703 method is to be used, and how the various methods are chained
19704 together---for instance, under which circumstances NSS should try the
19705 next method in the list. The NSS configuration is given in the
19706 @code{name-service-switch} field of @code{operating-system} declarations
19707 (@pxref{operating-system Reference, @code{name-service-switch}}).
19710 @cindex .local, host name lookup
19711 As an example, the declaration below configures the NSS to use the
19712 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
19713 back-end}, which supports host name lookups over multicast DNS (mDNS)
19714 for host names ending in @code{.local}:
19717 (name-service-switch
19718 (hosts (list %files ;first, check /etc/hosts
19720 ;; If the above did not succeed, try
19721 ;; with 'mdns_minimal'.
19723 (name "mdns_minimal")
19725 ;; 'mdns_minimal' is authoritative for
19726 ;; '.local'. When it returns "not found",
19727 ;; no need to try the next methods.
19728 (reaction (lookup-specification
19729 (not-found => return))))
19731 ;; Then fall back to DNS.
19735 ;; Finally, try with the "full" 'mdns'.
19740 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
19741 contains this configuration, so you will not have to type it if all you
19742 want is to have @code{.local} host lookup working.
19744 Note that, in this case, in addition to setting the
19745 @code{name-service-switch} of the @code{operating-system} declaration,
19746 you also need to use @code{avahi-service} (@pxref{Networking Services,
19747 @code{avahi-service}}), or @var{%desktop-services}, which includes it
19748 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
19749 to the name service cache daemon (@pxref{Base Services,
19750 @code{nscd-service}}).
19752 For convenience, the following variables provide typical NSS
19755 @defvr {Scheme Variable} %default-nss
19756 This is the default name service switch configuration, a
19757 @code{name-service-switch} object.
19760 @defvr {Scheme Variable} %mdns-host-lookup-nss
19761 This is the name service switch configuration with support for host name
19762 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
19765 The reference for name service switch configuration is given below. It
19766 is a direct mapping of the configuration file format of the C library , so
19767 please refer to the C library manual for more information (@pxref{NSS
19768 Configuration File,,, libc, The GNU C Library Reference Manual}).
19769 Compared to the configuration file format of libc NSS, it has the advantage
19770 not only of adding this warm parenthetic feel that we like, but also
19771 static checks: you will know about syntax errors and typos as soon as you
19772 run @command{guix system}.
19774 @deftp {Data Type} name-service-switch
19776 This is the data type representation the configuration of libc's name
19777 service switch (NSS). Each field below represents one of the supported
19794 The system databases handled by the NSS. Each of these fields must be a
19795 list of @code{<name-service>} objects (see below).
19799 @deftp {Data Type} name-service
19801 This is the data type representing an actual name service and the
19802 associated lookup action.
19806 A string denoting the name service (@pxref{Services in the NSS
19807 configuration,,, libc, The GNU C Library Reference Manual}).
19809 Note that name services listed here must be visible to nscd. This is
19810 achieved by passing the @code{#:name-services} argument to
19811 @code{nscd-service} the list of packages providing the needed name
19812 services (@pxref{Base Services, @code{nscd-service}}).
19815 An action specified using the @code{lookup-specification} macro
19816 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
19817 Reference Manual}). For example:
19820 (lookup-specification (unavailable => continue)
19821 (success => return))
19826 @node Initial RAM Disk
19827 @subsection Initial RAM Disk
19830 @cindex initial RAM disk
19831 For bootstrapping purposes, the Linux-Libre kernel is passed an
19832 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
19833 root file system as well as an initialization script. The latter is
19834 responsible for mounting the real root file system, and for loading any
19835 kernel modules that may be needed to achieve that.
19837 The @code{initrd-modules} field of an @code{operating-system}
19838 declaration allows you to specify Linux-libre kernel modules that must
19839 be available in the initrd. In particular, this is where you would list
19840 modules needed to actually drive the hard disk where your root partition
19841 is---although the default value of @code{initrd-modules} should cover
19842 most use cases. For example, assuming you need the @code{megaraid_sas}
19843 module in addition to the default modules to be able to access your root
19844 file system, you would write:
19849 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
19852 @defvr {Scheme Variable} %base-initrd-modules
19853 This is the list of kernel modules included in the initrd by default.
19856 Furthermore, if you need lower-level customization, the @code{initrd}
19857 field of an @code{operating-system} declaration allows
19858 you to specify which initrd you would like to use. The @code{(gnu
19859 system linux-initrd)} module provides three ways to build an initrd: the
19860 high-level @code{base-initrd} procedure and the low-level
19861 @code{raw-initrd} and @code{expression->initrd} procedures.
19863 The @code{base-initrd} procedure is intended to cover most common uses.
19864 For example, if you want to add a bunch of kernel modules to be loaded
19865 at boot time, you can define the @code{initrd} field of the operating
19866 system declaration like this:
19869 (initrd (lambda (file-systems . rest)
19870 ;; Create a standard initrd but set up networking
19871 ;; with the parameters QEMU expects by default.
19872 (apply base-initrd file-systems
19873 #:qemu-networking? #t
19877 The @code{base-initrd} procedure also handles common use cases that
19878 involves using the system as a QEMU guest, or as a ``live'' system with
19879 volatile root file system.
19881 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
19882 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
19883 such as trying to guess which kernel modules and packages should be included
19884 to the initrd. An example use of @code{raw-initrd} is when a user has
19885 a custom Linux kernel configuration and default kernel modules included by
19886 @code{base-initrd} are not available.
19888 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
19889 honors several options passed on the Linux kernel command line
19890 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
19891 @code{-append} option of QEMU), notably:
19894 @item --load=@var{boot}
19895 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
19896 program, once it has mounted the root file system.
19898 GuixSD uses this option to yield control to a boot program that runs the
19899 service activation programs and then spawns the GNU@tie{}Shepherd, the
19900 initialization system.
19902 @item --root=@var{root}
19903 Mount @var{root} as the root file system. @var{root} can be a
19904 device name like @code{/dev/sda1}, a file system label, or a file system
19907 @item --system=@var{system}
19908 Have @file{/run/booted-system} and @file{/run/current-system} point to
19911 @item modprobe.blacklist=@var{modules}@dots{}
19912 @cindex module, black-listing
19913 @cindex black list, of kernel modules
19914 Instruct the initial RAM disk as well as the @command{modprobe} command
19915 (from the kmod package) to refuse to load @var{modules}. @var{modules}
19916 must be a comma-separated list of module names---e.g.,
19917 @code{usbkbd,9pnet}.
19920 Start a read-eval-print loop (REPL) from the initial RAM disk before it
19921 tries to load kernel modules and to mount the root file system. Our
19922 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
19923 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
19924 Manual}, for more information on Guile's REPL.
19928 Now that you know all the features that initial RAM disks produced by
19929 @code{base-initrd} and @code{raw-initrd} provide,
19930 here is how to use it and customize it further.
19933 @cindex initial RAM disk
19934 @deffn {Monadic Procedure} raw-initrd @var{file-systems} @
19935 [#:linux-modules '()] [#:mapped-devices '()] @
19936 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
19937 Return a monadic derivation that builds a raw initrd. @var{file-systems} is
19938 a list of file systems to be mounted by the initrd, possibly in addition to
19939 the root file system specified on the kernel command line via @code{--root}.
19940 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
19941 @var{mapped-devices} is a list of device mappings to realize before
19942 @var{file-systems} are mounted (@pxref{Mapped Devices}).
19943 @var{helper-packages} is a list of packages to be copied in the initrd. It may
19944 include @code{e2fsck/static} or other packages needed by the initrd to check
19945 the root file system.
19947 When @var{qemu-networking?} is true, set up networking with the standard QEMU
19948 parameters. When @var{virtio?} is true, load additional modules so that the
19949 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
19951 When @var{volatile-root?} is true, the root file system is writable but any changes
19955 @deffn {Monadic Procedure} base-initrd @var{file-systems} @
19956 [#:mapped-devices '()] [#:qemu-networking? #f] [#:volatile-root? #f]@
19957 [#:linux-modules '()]
19958 Return a monadic derivation that builds a generic initrd, with kernel
19959 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
19960 mounted by the initrd, possibly in addition to the root file system specified
19961 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
19962 mappings to realize before @var{file-systems} are mounted.
19964 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
19966 The initrd is automatically populated with all the kernel modules necessary
19967 for @var{file-systems} and for the given options. Additional kernel
19968 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
19969 loaded at boot time in the order in which they appear.
19972 Needless to say, the initrds we produce and use embed a
19973 statically-linked Guile, and the initialization program is a Guile
19974 program. That gives a lot of flexibility. The
19975 @code{expression->initrd} procedure builds such an initrd, given the
19976 program to run in that initrd.
19978 @deffn {Monadic Procedure} expression->initrd @var{exp} @
19979 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
19980 Return a derivation that builds a Linux initrd (a gzipped cpio archive)
19981 containing @var{guile} and that evaluates @var{exp}, a G-expression,
19982 upon booting. All the derivations referenced by @var{exp} are
19983 automatically copied to the initrd.
19986 @node Bootloader Configuration
19987 @subsection Bootloader Configuration
19990 @cindex boot loader
19992 The operating system supports multiple bootloaders. The bootloader is
19993 configured using @code{bootloader-configuration} declaration. All the
19994 fields of this structure are bootloader agnostic except for one field,
19995 @code{bootloader} that indicates the bootloader to be configured and
19998 Some of the bootloaders do not honor every field of
19999 @code{bootloader-configuration}. For instance, the extlinux
20000 bootloader does not support themes and thus ignores the @code{theme}
20003 @deftp {Data Type} bootloader-configuration
20004 The type of a bootloader configuration declaration.
20008 @item @code{bootloader}
20009 @cindex EFI, bootloader
20010 @cindex UEFI, bootloader
20011 @cindex BIOS, bootloader
20012 The bootloader to use, as a @code{bootloader} object. For now
20013 @code{grub-bootloader}, @code{grub-efi-bootloader},
20014 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
20015 @code{grub-efi-bootloader} allows to boot on modern systems using the
20016 @dfn{Unified Extensible Firmware Interface} (UEFI).
20018 Available bootloaders are described in @code{(gnu bootloader @dots{})}
20021 @item @code{target}
20022 This is a string denoting the target onto which to install the
20023 bootloader. The exact interpretation depends on the bootloader in
20024 question; for @code{grub-bootloader}, for example, it should be a device
20025 name understood by the bootloader @command{installer} command, such as
20026 @code{/dev/sda} or @code{(hd0)} (for GRUB, @pxref{Invoking
20027 grub-install,,, grub, GNU GRUB Manual}). For
20028 @code{grub-efi-bootloader}, it should be the path to a mounted EFI file
20031 @item @code{menu-entries} (default: @code{()})
20032 A possibly empty list of @code{menu-entry} objects (see below), denoting
20033 entries to appear in the bootloader menu, in addition to the current
20034 system entry and the entry pointing to previous system generations.
20036 @item @code{default-entry} (default: @code{0})
20037 The index of the default boot menu entry. Index 0 is for the entry of the
20040 @item @code{timeout} (default: @code{5})
20041 The number of seconds to wait for keyboard input before booting. Set to
20042 0 to boot immediately, and to -1 to wait indefinitely.
20044 @item @code{theme} (default: @var{#f})
20045 The bootloader theme object describing the theme to use. If no theme
20046 is provided, some bootloaders might use a default theme, that's true
20049 @item @code{terminal-outputs} (default: @code{'gfxterm})
20050 The output terminals used for the bootloader boot menu, as a list of
20051 symbols. GRUB accepts the values: @code{console}, @code{serial},
20052 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
20053 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
20054 corresponds to the GRUB variable GRUB_TERMINAL_OUTPUT (@pxref{Simple
20055 configuration,,, grub,GNU GRUB manual}).
20057 @item @code{terminal-inputs} (default: @code{'()})
20058 The input terminals used for the bootloader boot menu, as a list of
20059 symbols. For GRUB, the default is the native platform terminal as
20060 determined at run-time. GRUB accepts the values: @code{console},
20061 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
20062 @code{usb_keyboard}. This field corresponds to the GRUB variable
20063 GRUB_TERMINAL_INPUT (@pxref{Simple configuration,,, grub,GNU GRUB
20066 @item @code{serial-unit} (default: @code{#f})
20067 The serial unit used by the bootloader, as an integer from 0 to 3.
20068 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
20069 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
20071 @item @code{serial-speed} (default: @code{#f})
20072 The speed of the serial interface, as an integer. For GRUB, the
20073 default value is chosen at run-time; currently GRUB chooses
20074 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
20081 Should you want to list additional boot menu entries @i{via} the
20082 @code{menu-entries} field above, you will need to create them with the
20083 @code{menu-entry} form. For example, imagine you want to be able to
20084 boot another distro (hard to imagine!), you can define a menu entry
20089 (label "The Other Distro")
20090 (linux "/boot/old/vmlinux-2.6.32")
20091 (linux-arguments '("root=/dev/sda2"))
20092 (initrd "/boot/old/initrd"))
20097 @deftp {Data Type} menu-entry
20098 The type of an entry in the bootloader menu.
20103 The label to show in the menu---e.g., @code{"GNU"}.
20106 The Linux kernel image to boot, for example:
20109 (file-append linux-libre "/bzImage")
20112 For GRUB, it is also possible to specify a device explicitly in the
20113 file path using GRUB's device naming convention (@pxref{Naming
20114 convention,,, grub, GNU GRUB manual}), for example:
20117 "(hd0,msdos1)/boot/vmlinuz"
20120 If the device is specified explicitly as above, then the @code{device}
20121 field is ignored entirely.
20123 @item @code{linux-arguments} (default: @code{()})
20124 The list of extra Linux kernel command-line arguments---e.g.,
20125 @code{("console=ttyS0")}.
20127 @item @code{initrd}
20128 A G-Expression or string denoting the file name of the initial RAM disk
20129 to use (@pxref{G-Expressions}).
20130 @item @code{device} (default: @code{#f})
20131 The device where the kernel and initrd are to be found---i.e., for GRUB,
20132 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
20134 This may be a file system label (a string), a file system UUID (a
20135 bytevector, @pxref{File Systems}), or @code{#f}, in which case
20136 the bootloader will search the device containing the file specified by
20137 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
20138 must @emph{not} be an OS device name such as @file{/dev/sda1}.
20143 @c FIXME: Write documentation once it's stable.
20144 Fow now only GRUB has theme support. GRUB themes are created using
20145 the @code{grub-theme} form, which is not documented yet.
20147 @defvr {Scheme Variable} %default-theme
20148 This is the default GRUB theme used by the operating system if no
20149 @code{theme} field is specified in @code{bootloader-configuration}
20152 It comes with a fancy background image displaying the GNU and Guix
20157 @node Invoking guix system
20158 @subsection Invoking @code{guix system}
20160 Once you have written an operating system declaration as seen in the
20161 previous section, it can be @dfn{instantiated} using the @command{guix
20162 system} command. The synopsis is:
20165 guix system @var{options}@dots{} @var{action} @var{file}
20168 @var{file} must be the name of a file containing an
20169 @code{operating-system} declaration. @var{action} specifies how the
20170 operating system is instantiated. Currently the following values are
20175 Display available service type definitions that match the given regular
20176 expressions, sorted by relevance:
20179 $ guix system search console font
20180 name: console-fonts
20181 location: gnu/services/base.scm:729:2
20182 extends: shepherd-root
20183 description: Install the given fonts on the specified ttys (fonts are
20184 + per virtual console on GNU/Linux). The value of this service is a list
20185 + of tty/font pairs like:
20187 + '(("tty1" . "LatGrkCyr-8x16"))
20191 location: gnu/services/base.scm:1048:2
20192 extends: shepherd-root
20193 description: Provide console login using the `mingetty' program.
20197 location: gnu/services/base.scm:775:2
20199 description: Provide a console log-in service as specified by its
20200 + configuration value, a `login-configuration' object.
20206 As for @command{guix package --search}, the result is written in
20207 @code{recutils} format, which makes it easy to filter the output
20208 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
20211 Build the operating system described in @var{file}, activate it, and
20212 switch to it@footnote{This action (and the related actions
20213 @code{switch-generation} and @code{roll-back}) are usable only on
20214 systems already running GuixSD.}.
20216 This effects all the configuration specified in @var{file}: user
20217 accounts, system services, global package list, setuid programs, etc.
20218 The command starts system services specified in @var{file} that are not
20219 currently running; if a service is currently running, it does not
20220 attempt to upgrade it since this would not be possible without stopping it
20223 This command creates a new generation whose number is one greater than
20224 the current generation (as reported by @command{guix system
20225 list-generations}). If that generation already exists, it will be
20226 overwritten. This behavior mirrors that of @command{guix package}
20227 (@pxref{Invoking guix package}).
20229 It also adds a bootloader menu entry for the new OS configuration,
20230 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
20231 entries for older configurations to a submenu, allowing you to choose
20232 an older system generation at boot time should you need it.
20235 @c The paragraph below refers to the problem discussed at
20236 @c <http://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
20237 It is highly recommended to run @command{guix pull} once before you run
20238 @command{guix system reconfigure} for the first time (@pxref{Invoking
20239 guix pull}). Failing to do that you would see an older version of Guix
20240 once @command{reconfigure} has completed.
20243 @item switch-generation
20244 @cindex generations
20245 Switch to an existing system generation. This action atomically
20246 switches the system profile to the specified system generation. It
20247 also rearranges the system's existing bootloader menu entries. It
20248 makes the menu entry for the specified system generation the default,
20249 and it moves the entries for the other generatiors to a submenu, if
20250 supported by the bootloader being used. The next time the system
20251 boots, it will use the specified system generation.
20253 The bootloader itself is not being reinstalled when using this
20254 command. Thus, the installed bootloader is used with an updated
20255 configuration file.
20257 The target generation can be specified explicitly by its generation
20258 number. For example, the following invocation would switch to system
20262 guix system switch-generation 7
20265 The target generation can also be specified relative to the current
20266 generation with the form @code{+N} or @code{-N}, where @code{+3} means
20267 ``3 generations ahead of the current generation,'' and @code{-1} means
20268 ``1 generation prior to the current generation.'' When specifying a
20269 negative value such as @code{-1}, you must precede it with @code{--} to
20270 prevent it from being parsed as an option. For example:
20273 guix system switch-generation -- -1
20276 Currently, the effect of invoking this action is @emph{only} to switch
20277 the system profile to an existing generation and rearrange the
20278 bootloader menu entries. To actually start using the target system
20279 generation, you must reboot after running this action. In the future,
20280 it will be updated to do the same things as @command{reconfigure},
20281 like activating and deactivating services.
20283 This action will fail if the specified generation does not exist.
20286 @cindex rolling back
20287 Switch to the preceding system generation. The next time the system
20288 boots, it will use the preceding system generation. This is the inverse
20289 of @command{reconfigure}, and it is exactly the same as invoking
20290 @command{switch-generation} with an argument of @code{-1}.
20292 Currently, as with @command{switch-generation}, you must reboot after
20293 running this action to actually start using the preceding system
20297 Build the derivation of the operating system, which includes all the
20298 configuration files and programs needed to boot and run the system.
20299 This action does not actually install anything.
20302 Populate the given directory with all the files necessary to run the
20303 operating system specified in @var{file}. This is useful for first-time
20304 installations of GuixSD. For instance:
20307 guix system init my-os-config.scm /mnt
20310 copies to @file{/mnt} all the store items required by the configuration
20311 specified in @file{my-os-config.scm}. This includes configuration
20312 files, packages, and so on. It also creates other essential files
20313 needed for the system to operate correctly---e.g., the @file{/etc},
20314 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
20316 This command also installs bootloader on the target specified in
20317 @file{my-os-config}, unless the @option{--no-bootloader} option was
20321 @cindex virtual machine
20323 @anchor{guix system vm}
20324 Build a virtual machine that contains the operating system declared in
20325 @var{file}, and return a script to run that virtual machine (VM).
20326 Arguments given to the script are passed to QEMU as in the example
20327 below, which enables networking and requests 1@tie{}GiB of RAM for the
20331 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
20334 The VM shares its store with the host system.
20336 Additional file systems can be shared between the host and the VM using
20337 the @code{--share} and @code{--expose} command-line options: the former
20338 specifies a directory to be shared with write access, while the latter
20339 provides read-only access to the shared directory.
20341 The example below creates a VM in which the user's home directory is
20342 accessible read-only, and where the @file{/exchange} directory is a
20343 read-write mapping of @file{$HOME/tmp} on the host:
20346 guix system vm my-config.scm \
20347 --expose=$HOME --share=$HOME/tmp=/exchange
20350 On GNU/Linux, the default is to boot directly to the kernel; this has
20351 the advantage of requiring only a very tiny root disk image since the
20352 store of the host can then be mounted.
20354 The @code{--full-boot} option forces a complete boot sequence, starting
20355 with the bootloader. This requires more disk space since a root image
20356 containing at least the kernel, initrd, and bootloader data files must
20357 be created. The @code{--image-size} option can be used to specify the
20362 Return a virtual machine or disk image of the operating system declared
20363 in @var{file} that stands alone. By default, @command{guix system}
20364 estimates the size of the image needed to store the system, but you can
20365 use the @option{--image-size} option to specify a value.
20367 You can specify the root file system type by using the
20368 @option{--file-system-type} option. It defaults to @code{ext4}.
20370 When using @code{vm-image}, the returned image is in qcow2 format, which
20371 the QEMU emulator can efficiently use. @xref{Running GuixSD in a VM},
20372 for more information on how to run the image in a virtual machine.
20374 When using @code{disk-image}, a raw disk image is produced; it can be
20375 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
20376 the device corresponding to a USB stick, one can copy the image to it
20377 using the following command:
20380 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
20384 Return a script to run the operating system declared in @var{file}
20385 within a container. Containers are a set of lightweight isolation
20386 mechanisms provided by the kernel Linux-libre. Containers are
20387 substantially less resource-demanding than full virtual machines since
20388 the kernel, shared objects, and other resources can be shared with the
20389 host system; this also means they provide thinner isolation.
20391 Currently, the script must be run as root in order to support more than
20392 a single user and group. The container shares its store with the host
20395 As with the @code{vm} action (@pxref{guix system vm}), additional file
20396 systems to be shared between the host and container can be specified
20397 using the @option{--share} and @option{--expose} options:
20400 guix system container my-config.scm \
20401 --expose=$HOME --share=$HOME/tmp=/exchange
20405 This option requires Linux-libre 3.19 or newer.
20410 @var{options} can contain any of the common build options (@pxref{Common
20411 Build Options}). In addition, @var{options} can contain one of the
20415 @item --expression=@var{expr}
20416 @itemx -e @var{expr}
20417 Consider the operating-system @var{expr} evaluates to.
20418 This is an alternative to specifying a file which evaluates to an
20420 This is used to generate the GuixSD installer @pxref{Building the
20421 Installation Image}).
20423 @item --system=@var{system}
20424 @itemx -s @var{system}
20425 Attempt to build for @var{system} instead of the host system type.
20426 This works as per @command{guix build} (@pxref{Invoking guix build}).
20430 Return the derivation file name of the given operating system without
20433 @item --file-system-type=@var{type}
20434 @itemx -t @var{type}
20435 For the @code{disk-image} action, create a file system of the given
20436 @var{type} on the image.
20438 When this option is omitted, @command{guix system} uses @code{ext4}.
20440 @cindex ISO-9660 format
20441 @cindex CD image format
20442 @cindex DVD image format
20443 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
20444 for burning on CDs and DVDs.
20446 @item --image-size=@var{size}
20447 For the @code{vm-image} and @code{disk-image} actions, create an image
20448 of the given @var{size}. @var{size} may be a number of bytes, or it may
20449 include a unit as a suffix (@pxref{Block size, size specifications,,
20450 coreutils, GNU Coreutils}).
20452 When this option is omitted, @command{guix system} computes an estimate
20453 of the image size as a function of the size of the system declared in
20456 @item --root=@var{file}
20457 @itemx -r @var{file}
20458 Make @var{file} a symlink to the result, and register it as a garbage
20461 @item --skip-checks
20462 Skip pre-installation safety checks.
20464 By default, @command{guix system init} and @command{guix system
20465 reconfigure} perform safety checks: they make sure the file systems that
20466 appear in the @code{operating-system} declaration actually exist
20467 (@pxref{File Systems}), and that any Linux kernel modules that may be
20468 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
20469 RAM Disk}). Passing this option skips these tests altogether.
20471 @item --on-error=@var{strategy}
20472 Apply @var{strategy} when an error occurs when reading @var{file}.
20473 @var{strategy} may be one of the following:
20476 @item nothing-special
20477 Report the error concisely and exit. This is the default strategy.
20480 Likewise, but also display a backtrace.
20483 Report the error and enter Guile's debugger. From there, you can run
20484 commands such as @code{,bt} to get a backtrace, @code{,locals} to
20485 display local variable values, and more generally inspect the state of the
20486 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
20487 a list of available debugging commands.
20492 All the actions above, except @code{build} and @code{init},
20493 can use KVM support in the Linux-libre kernel. Specifically, if the
20494 machine has hardware virtualization support, the corresponding
20495 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
20496 must exist and be readable and writable by the user and by the
20497 build users of the daemon (@pxref{Build Environment Setup}).
20500 Once you have built, configured, re-configured, and re-re-configured
20501 your GuixSD installation, you may find it useful to list the operating
20502 system generations available on disk---and that you can choose from the
20503 bootloader boot menu:
20507 @item list-generations
20508 List a summary of each generation of the operating system available on
20509 disk, in a human-readable way. This is similar to the
20510 @option{--list-generations} option of @command{guix package}
20511 (@pxref{Invoking guix package}).
20513 Optionally, one can specify a pattern, with the same syntax that is used
20514 in @command{guix package --list-generations}, to restrict the list of
20515 generations displayed. For instance, the following command displays
20516 generations that are up to 10 days old:
20519 $ guix system list-generations 10d
20524 The @command{guix system} command has even more to offer! The following
20525 sub-commands allow you to visualize how your system services relate to
20528 @anchor{system-extension-graph}
20531 @item extension-graph
20532 Emit in Dot/Graphviz format to standard output the @dfn{service
20533 extension graph} of the operating system defined in @var{file}
20534 (@pxref{Service Composition}, for more information on service
20540 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
20543 produces a PDF file showing the extension relations among services.
20545 @anchor{system-shepherd-graph}
20546 @item shepherd-graph
20547 Emit in Dot/Graphviz format to standard output the @dfn{dependency
20548 graph} of shepherd services of the operating system defined in
20549 @var{file}. @xref{Shepherd Services}, for more information and for an
20554 @node Running GuixSD in a VM
20555 @subsection Running GuixSD in a Virtual Machine
20557 @cindex virtual machine
20558 To run GuixSD in a virtual machine (VM), one can either use the
20559 pre-built GuixSD VM image distributed at
20560 @indicateurl{ftp://alpha.gnu.org/guix/guixsd-vm-image-@value{VERSION}.@var{system}.tar.xz}
20561 , or build their own virtual machine image using @command{guix system
20562 vm-image} (@pxref{Invoking guix system}). The returned image is in
20563 qcow2 format, which the @uref{http://qemu.org/, QEMU emulator} can
20567 If you built your own image, you must copy it out of the store
20568 (@pxref{The Store}) and give yourself permission to write to the copy
20569 before you can use it. When invoking QEMU, you must choose a system
20570 emulator that is suitable for your hardware platform. Here is a minimal
20571 QEMU invocation that will boot the result of @command{guix system
20572 vm-image} on x86_64 hardware:
20575 $ qemu-system-x86_64 \
20576 -net user -net nic,model=virtio \
20577 -enable-kvm -m 256 /tmp/qemu-image
20580 Here is what each of these options means:
20583 @item qemu-system-x86_64
20584 This specifies the hardware platform to emulate. This should match the
20588 Enable the unprivileged user-mode network stack. The guest OS can
20589 access the host but not vice versa. This is the simplest way to get the
20592 @item -net nic,model=virtio
20593 You must create a network interface of a given model. If you do not
20594 create a NIC, the boot will fail. Assuming your hardware platform is
20595 x86_64, you can get a list of available NIC models by running
20596 @command{qemu-system-x86_64 -net nic,model=help}.
20599 If your system has hardware virtualization extensions, enabling the
20600 virtual machine support (KVM) of the Linux kernel will make things run
20604 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
20605 which may be insufficient for some operations.
20607 @item /tmp/qemu-image
20608 The file name of the qcow2 image.
20611 The default @command{run-vm.sh} script that is returned by an invocation of
20612 @command{guix system vm} does not add a @command{-net user} flag by default.
20613 To get network access from within the vm add the @code{(dhcp-client-service)}
20614 to your system definition and start the VM using
20615 @command{`guix system vm config.scm` -net user}. An important caveat of using
20616 @command{-net user} for networking is that @command{ping} will not work, because
20617 it uses the ICMP protocol. You'll have to use a different command to check for
20618 network connectivity, for example @command{guix download}.
20620 @subsubsection Connecting Through SSH
20624 To enable SSH inside a VM you need to add a SSH server like @code{(dropbear-service)}
20625 or @code{(lsh-service)} to your VM. The @code{(lsh-service}) doesn't currently
20626 boot unsupervised. It requires you to type some characters to initialize the
20627 randomness generator. In addition you need to forward the SSH port, 22 by
20628 default, to the host. You can do this with
20631 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
20634 To connect to the VM you can run
20637 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
20640 The @command{-p} tells @command{ssh} the port you want to connect to.
20641 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
20642 every time you modify your @command{config.scm} file and the
20643 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
20644 connection to an unknown host every time you connect.
20646 @subsubsection Using @command{virt-viewer} with Spice
20648 As an alternative to the default @command{qemu} graphical client you can
20649 use the @command{remote-viewer} from the @command{virt-viewer} package. To
20650 connect pass the @command{-spice port=5930,disable-ticketing} flag to
20651 @command{qemu}. See previous section for further information on how to do this.
20653 Spice also allows you to do some nice stuff like share your clipboard with your
20654 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
20657 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
20658 -chardev spicevmc,name=vdagent,id=vdagent
20659 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
20660 name=com.redhat.spice.0
20663 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
20665 @node Defining Services
20666 @subsection Defining Services
20668 The previous sections show the available services and how one can combine
20669 them in an @code{operating-system} declaration. But how do we define
20670 them in the first place? And what is a service anyway?
20673 * Service Composition:: The model for composing services.
20674 * Service Types and Services:: Types and services.
20675 * Service Reference:: API reference.
20676 * Shepherd Services:: A particular type of service.
20679 @node Service Composition
20680 @subsubsection Service Composition
20684 Here we define a @dfn{service} as, broadly, something that extends the
20685 functionality of the operating system. Often a service is a process---a
20686 @dfn{daemon}---started when the system boots: a secure shell server, a
20687 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
20688 whose execution can be triggered by another daemon---e.g., an FTP server
20689 started by @command{inetd} or a D-Bus service activated by
20690 @command{dbus-daemon}. Occasionally, a service does not map to a
20691 daemon. For instance, the ``account'' service collects user accounts
20692 and makes sure they exist when the system runs; the ``udev'' service
20693 collects device management rules and makes them available to the eudev
20694 daemon; the @file{/etc} service populates the @file{/etc} directory
20697 @cindex service extensions
20698 GuixSD services are connected by @dfn{extensions}. For instance, the
20699 secure shell service @emph{extends} the Shepherd---the GuixSD
20700 initialization system, running as PID@tie{}1---by giving it the command
20701 lines to start and stop the secure shell daemon (@pxref{Networking
20702 Services, @code{lsh-service}}); the UPower service extends the D-Bus
20703 service by passing it its @file{.service} specification, and extends the
20704 udev service by passing it device management rules (@pxref{Desktop
20705 Services, @code{upower-service}}); the Guix daemon service extends the
20706 Shepherd by passing it the command lines to start and stop the daemon,
20707 and extends the account service by passing it a list of required build
20708 user accounts (@pxref{Base Services}).
20710 All in all, services and their ``extends'' relations form a directed
20711 acyclic graph (DAG). If we represent services as boxes and extensions
20712 as arrows, a typical system might provide something like this:
20714 @image{images/service-graph,,5in,Typical service extension graph.}
20716 @cindex system service
20717 At the bottom, we see the @dfn{system service}, which produces the
20718 directory containing everything to run and boot the system, as returned
20719 by the @command{guix system build} command. @xref{Service Reference},
20720 to learn about the other service types shown here.
20721 @xref{system-extension-graph, the @command{guix system extension-graph}
20722 command}, for information on how to generate this representation for a
20723 particular operating system definition.
20725 @cindex service types
20726 Technically, developers can define @dfn{service types} to express these
20727 relations. There can be any number of services of a given type on the
20728 system---for instance, a system running two instances of the GNU secure
20729 shell server (lsh) has two instances of @var{lsh-service-type}, with
20730 different parameters.
20732 The following section describes the programming interface for service
20733 types and services.
20735 @node Service Types and Services
20736 @subsubsection Service Types and Services
20738 A @dfn{service type} is a node in the DAG described above. Let us start
20739 with a simple example, the service type for the Guix build daemon
20740 (@pxref{Invoking guix-daemon}):
20743 (define guix-service-type
20747 (list (service-extension shepherd-root-service-type guix-shepherd-service)
20748 (service-extension account-service-type guix-accounts)
20749 (service-extension activation-service-type guix-activation)))
20750 (default-value (guix-configuration))))
20754 It defines three things:
20758 A name, whose sole purpose is to make inspection and debugging easier.
20761 A list of @dfn{service extensions}, where each extension designates the
20762 target service type and a procedure that, given the parameters of the
20763 service, returns a list of objects to extend the service of that type.
20765 Every service type has at least one service extension. The only
20766 exception is the @dfn{boot service type}, which is the ultimate service.
20769 Optionally, a default value for instances of this type.
20772 In this example, @var{guix-service-type} extends three services:
20775 @item shepherd-root-service-type
20776 The @var{guix-shepherd-service} procedure defines how the Shepherd
20777 service is extended. Namely, it returns a @code{<shepherd-service>}
20778 object that defines how @command{guix-daemon} is started and stopped
20779 (@pxref{Shepherd Services}).
20781 @item account-service-type
20782 This extension for this service is computed by @var{guix-accounts},
20783 which returns a list of @code{user-group} and @code{user-account}
20784 objects representing the build user accounts (@pxref{Invoking
20787 @item activation-service-type
20788 Here @var{guix-activation} is a procedure that returns a gexp, which is
20789 a code snippet to run at ``activation time''---e.g., when the service is
20793 A service of this type is instantiated like this:
20796 (service guix-service-type
20797 (guix-configuration
20799 (use-substitutes? #f)))
20802 The second argument to the @code{service} form is a value representing
20803 the parameters of this specific service instance.
20804 @xref{guix-configuration-type, @code{guix-configuration}}, for
20805 information about the @code{guix-configuration} data type. When the
20806 value is omitted, the default value specified by
20807 @code{guix-service-type} is used:
20810 (service guix-service-type)
20813 @var{guix-service-type} is quite simple because it extends other
20814 services but is not extensible itself.
20816 @c @subsubsubsection Extensible Service Types
20818 The service type for an @emph{extensible} service looks like this:
20821 (define udev-service-type
20822 (service-type (name 'udev)
20824 (list (service-extension shepherd-root-service-type
20825 udev-shepherd-service)))
20827 (compose concatenate) ;concatenate the list of rules
20828 (extend (lambda (config rules)
20830 (($ <udev-configuration> udev initial-rules)
20831 (udev-configuration
20832 (udev udev) ;the udev package to use
20833 (rules (append initial-rules rules)))))))))
20836 This is the service type for the
20837 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
20838 management daemon}. Compared to the previous example, in addition to an
20839 extension of @var{shepherd-root-service-type}, we see two new fields:
20843 This is the procedure to @dfn{compose} the list of extensions to
20844 services of this type.
20846 Services can extend the udev service by passing it lists of rules; we
20847 compose those extensions simply by concatenating them.
20850 This procedure defines how the value of the service is @dfn{extended} with
20851 the composition of the extensions.
20853 Udev extensions are composed into a list of rules, but the udev service
20854 value is itself a @code{<udev-configuration>} record. So here, we
20855 extend that record by appending the list of rules it contains to the
20856 list of contributed rules.
20859 This is a string giving an overview of the service type. The string can
20860 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
20861 @command{guix system search} command searches these strings and displays
20862 them (@pxref{Invoking guix system}).
20865 There can be only one instance of an extensible service type such as
20866 @var{udev-service-type}. If there were more, the
20867 @code{service-extension} specifications would be ambiguous.
20869 Still here? The next section provides a reference of the programming
20870 interface for services.
20872 @node Service Reference
20873 @subsubsection Service Reference
20875 We have seen an overview of service types (@pxref{Service Types and
20876 Services}). This section provides a reference on how to manipulate
20877 services and service types. This interface is provided by the
20878 @code{(gnu services)} module.
20880 @deffn {Scheme Procedure} service @var{type} [@var{value}]
20881 Return a new service of @var{type}, a @code{<service-type>} object (see
20882 below.) @var{value} can be any object; it represents the parameters of
20883 this particular service instance.
20885 When @var{value} is omitted, the default value specified by @var{type}
20886 is used; if @var{type} does not specify a default value, an error is
20889 For instance, this:
20892 (service openssh-service-type)
20896 is equivalent to this:
20899 (service openssh-service-type
20900 (openssh-configuration))
20903 In both cases the result is an instance of @code{openssh-service-type}
20904 with the default configuration.
20907 @deffn {Scheme Procedure} service? @var{obj}
20908 Return true if @var{obj} is a service.
20911 @deffn {Scheme Procedure} service-kind @var{service}
20912 Return the type of @var{service}---i.e., a @code{<service-type>} object.
20915 @deffn {Scheme Procedure} service-value @var{service}
20916 Return the value associated with @var{service}. It represents its
20920 Here is an example of how a service is created and manipulated:
20924 (service nginx-service-type
20925 (nginx-configuration
20927 (log-directory log-directory)
20928 (run-directory run-directory)
20929 (file config-file))))
20934 (eq? (service-kind s) nginx-service-type)
20938 The @code{modify-services} form provides a handy way to change the
20939 parameters of some of the services of a list such as
20940 @var{%base-services} (@pxref{Base Services, @code{%base-services}}). It
20941 evaluates to a list of services. Of course, you could always use
20942 standard list combinators such as @code{map} and @code{fold} to do that
20943 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
20944 @code{modify-services} simply provides a more concise form for this
20947 @deffn {Scheme Syntax} modify-services @var{services} @
20948 (@var{type} @var{variable} => @var{body}) @dots{}
20950 Modify the services listed in @var{services} according to the given
20951 clauses. Each clause has the form:
20954 (@var{type} @var{variable} => @var{body})
20957 where @var{type} is a service type---e.g.,
20958 @code{guix-service-type}---and @var{variable} is an identifier that is
20959 bound within the @var{body} to the service parameters---e.g., a
20960 @code{guix-configuration} instance---of the original service of that
20963 The @var{body} should evaluate to the new service parameters, which will
20964 be used to configure the new service. This new service will replace the
20965 original in the resulting list. Because a service's service parameters
20966 are created using @code{define-record-type*}, you can write a succinct
20967 @var{body} that evaluates to the new service parameters by using the
20968 @code{inherit} feature that @code{define-record-type*} provides.
20970 @xref{Using the Configuration System}, for example usage.
20974 Next comes the programming interface for service types. This is
20975 something you want to know when writing new service definitions, but not
20976 necessarily when simply looking for ways to customize your
20977 @code{operating-system} declaration.
20979 @deftp {Data Type} service-type
20980 @cindex service type
20981 This is the representation of a @dfn{service type} (@pxref{Service Types
20986 This is a symbol, used only to simplify inspection and debugging.
20988 @item @code{extensions}
20989 A non-empty list of @code{<service-extension>} objects (see below).
20991 @item @code{compose} (default: @code{#f})
20992 If this is @code{#f}, then the service type denotes services that cannot
20993 be extended---i.e., services that do not receive ``values'' from other
20996 Otherwise, it must be a one-argument procedure. The procedure is called
20997 by @code{fold-services} and is passed a list of values collected from
20998 extensions. It must return a value that is a valid parameter value for
20999 the service instance.
21001 @item @code{extend} (default: @code{#f})
21002 If this is @code{#f}, services of this type cannot be extended.
21004 Otherwise, it must be a two-argument procedure: @code{fold-services}
21005 calls it, passing it the initial value of the service as the first argument
21006 and the result of applying @code{compose} to the extension values as the
21010 @xref{Service Types and Services}, for examples.
21013 @deffn {Scheme Procedure} service-extension @var{target-type} @
21015 Return a new extension for services of type @var{target-type}.
21016 @var{compute} must be a one-argument procedure: @code{fold-services}
21017 calls it, passing it the value associated with the service that provides
21018 the extension; it must return a valid value for the target service.
21021 @deffn {Scheme Procedure} service-extension? @var{obj}
21022 Return true if @var{obj} is a service extension.
21025 Occasionally, you might want to simply extend an existing service. This
21026 involves creating a new service type and specifying the extension of
21027 interest, which can be verbose; the @code{simple-service} procedure
21028 provides a shorthand for this.
21030 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
21031 Return a service that extends @var{target} with @var{value}. This works
21032 by creating a singleton service type @var{name}, of which the returned
21033 service is an instance.
21035 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
21039 (simple-service 'my-mcron-job mcron-service-type
21040 #~(job '(next-hour (3)) "guix gc -F 2G"))
21044 At the core of the service abstraction lies the @code{fold-services}
21045 procedure, which is responsible for ``compiling'' a list of services
21046 down to a single directory that contains everything needed to boot and
21047 run the system---the directory shown by the @command{guix system build}
21048 command (@pxref{Invoking guix system}). In essence, it propagates
21049 service extensions down the service graph, updating each node parameters
21050 on the way, until it reaches the root node.
21052 @deffn {Scheme Procedure} fold-services @var{services} @
21053 [#:target-type @var{system-service-type}]
21054 Fold @var{services} by propagating their extensions down to the root of
21055 type @var{target-type}; return the root service adjusted accordingly.
21058 Lastly, the @code{(gnu services)} module also defines several essential
21059 service types, some of which are listed below.
21061 @defvr {Scheme Variable} system-service-type
21062 This is the root of the service graph. It produces the system directory
21063 as returned by the @command{guix system build} command.
21066 @defvr {Scheme Variable} boot-service-type
21067 The type of the ``boot service'', which produces the @dfn{boot script}.
21068 The boot script is what the initial RAM disk runs when booting.
21071 @defvr {Scheme Variable} etc-service-type
21072 The type of the @file{/etc} service. This service is used to create
21073 files under @file{/etc} and can be extended by
21074 passing it name/file tuples such as:
21077 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
21080 In this example, the effect would be to add an @file{/etc/issue} file
21081 pointing to the given file.
21084 @defvr {Scheme Variable} setuid-program-service-type
21085 Type for the ``setuid-program service''. This service collects lists of
21086 executable file names, passed as gexps, and adds them to the set of
21087 setuid-root programs on the system (@pxref{Setuid Programs}).
21090 @defvr {Scheme Variable} profile-service-type
21091 Type of the service that populates the @dfn{system profile}---i.e., the
21092 programs under @file{/run/current-system/profile}. Other services can
21093 extend it by passing it lists of packages to add to the system profile.
21097 @node Shepherd Services
21098 @subsubsection Shepherd Services
21100 @cindex shepherd services
21102 @cindex init system
21103 The @code{(gnu services shepherd)} module provides a way to define
21104 services managed by the GNU@tie{}Shepherd, which is the GuixSD
21105 initialization system---the first process that is started when the
21106 system boots, also known as PID@tie{}1
21107 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
21109 Services in the Shepherd can depend on each other. For instance, the
21110 SSH daemon may need to be started after the syslog daemon has been
21111 started, which in turn can only happen once all the file systems have
21112 been mounted. The simple operating system defined earlier (@pxref{Using
21113 the Configuration System}) results in a service graph like this:
21115 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
21117 You can actually generate such a graph for any operating system
21118 definition using the @command{guix system shepherd-graph} command
21119 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
21121 The @var{%shepherd-root-service} is a service object representing
21122 PID@tie{}1, of type @var{shepherd-root-service-type}; it can be extended
21123 by passing it lists of @code{<shepherd-service>} objects.
21125 @deftp {Data Type} shepherd-service
21126 The data type representing a service managed by the Shepherd.
21129 @item @code{provision}
21130 This is a list of symbols denoting what the service provides.
21132 These are the names that may be passed to @command{herd start},
21133 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
21134 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
21135 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
21137 @item @code{requirements} (default: @code{'()})
21138 List of symbols denoting the Shepherd services this one depends on.
21140 @item @code{respawn?} (default: @code{#t})
21141 Whether to restart the service when it stops, for instance when the
21142 underlying process dies.
21145 @itemx @code{stop} (default: @code{#~(const #f)})
21146 The @code{start} and @code{stop} fields refer to the Shepherd's
21147 facilities to start and stop processes (@pxref{Service De- and
21148 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
21149 G-expressions that get expanded in the Shepherd configuration file
21150 (@pxref{G-Expressions}).
21152 @item @code{documentation}
21153 A documentation string, as shown when running:
21156 herd doc @var{service-name}
21159 where @var{service-name} is one of the symbols in @var{provision}
21160 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
21162 @item @code{modules} (default: @var{%default-modules})
21163 This is the list of modules that must be in scope when @code{start} and
21164 @code{stop} are evaluated.
21169 @defvr {Scheme Variable} shepherd-root-service-type
21170 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
21172 This is the service type that extensions target when they want to create
21173 shepherd services (@pxref{Service Types and Services}, for an example).
21174 Each extension must pass a list of @code{<shepherd-service>}.
21177 @defvr {Scheme Variable} %shepherd-root-service
21178 This service represents PID@tie{}1.
21182 @node Documentation
21183 @section Documentation
21185 @cindex documentation, searching for
21186 @cindex searching for documentation
21187 @cindex Info, documentation format
21189 @cindex manual pages
21190 In most cases packages installed with Guix come with documentation.
21191 There are two main documentation formats: ``Info'', a browseable
21192 hypertext format used for GNU software, and ``manual pages'' (or ``man
21193 pages''), the linear documentation format traditionally found on Unix.
21194 Info manuals are accessed with the @command{info} command or with Emacs,
21195 and man pages are accessed using @command{man}.
21197 You can look for documentation of software installed on your system by
21198 keyword. For example, the following command searches for information
21199 about ``TLS'' in Info manuals:
21203 "(emacs)Network Security" -- STARTTLS
21204 "(emacs)Network Security" -- TLS
21205 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
21206 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
21211 The command below searches for the same keyword in man pages:
21215 SSL (7) - OpenSSL SSL/TLS library
21216 certtool (1) - GnuTLS certificate tool
21220 These searches are purely local to your computer so you have the
21221 guarantee that documentation you find corresponds to what you have
21222 actually installed, you can access it off-line, and your privacy is
21225 Once you have these results, you can view the relevant documentation by
21229 $ info "(gnutls)Core TLS API"
21239 Info manuals contain sections and indices as well as hyperlinks like
21240 those found in Web pages. The @command{info} reader (@pxref{Top, Info
21241 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
21242 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
21243 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
21244 Introduction}, for an introduction to Info navigation.
21246 @node Installing Debugging Files
21247 @section Installing Debugging Files
21249 @cindex debugging files
21250 Program binaries, as produced by the GCC compilers for instance, are
21251 typically written in the ELF format, with a section containing
21252 @dfn{debugging information}. Debugging information is what allows the
21253 debugger, GDB, to map binary code to source code; it is required to
21254 debug a compiled program in good conditions.
21256 The problem with debugging information is that is takes up a fair amount
21257 of disk space. For example, debugging information for the GNU C Library
21258 weighs in at more than 60 MiB. Thus, as a user, keeping all the
21259 debugging info of all the installed programs is usually not an option.
21260 Yet, space savings should not come at the cost of an impediment to
21261 debugging---especially in the GNU system, which should make it easier
21262 for users to exert their computing freedom (@pxref{GNU Distribution}).
21264 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
21265 mechanism that allows users to get the best of both worlds: debugging
21266 information can be stripped from the binaries and stored in separate
21267 files. GDB is then able to load debugging information from those files,
21268 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
21271 The GNU distribution takes advantage of this by storing debugging
21272 information in the @code{lib/debug} sub-directory of a separate package
21273 output unimaginatively called @code{debug} (@pxref{Packages with
21274 Multiple Outputs}). Users can choose to install the @code{debug} output
21275 of a package when they need it. For instance, the following command
21276 installs the debugging information for the GNU C Library and for GNU
21280 guix package -i glibc:debug guile:debug
21283 GDB must then be told to look for debug files in the user's profile, by
21284 setting the @code{debug-file-directory} variable (consider setting it
21285 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
21289 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
21292 From there on, GDB will pick up debugging information from the
21293 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
21295 In addition, you will most likely want GDB to be able to show the source
21296 code being debugged. To do that, you will have to unpack the source
21297 code of the package of interest (obtained with @code{guix build
21298 --source}, @pxref{Invoking guix build}), and to point GDB to that source
21299 directory using the @code{directory} command (@pxref{Source Path,
21300 @code{directory},, gdb, Debugging with GDB}).
21302 @c XXX: keep me up-to-date
21303 The @code{debug} output mechanism in Guix is implemented by the
21304 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
21305 opt-in---debugging information is available only for the packages
21306 with definitions explicitly declaring a @code{debug} output. This may be
21307 changed to opt-out in the future if our build farm servers can handle
21308 the load. To check whether a package has a @code{debug} output, use
21309 @command{guix package --list-available} (@pxref{Invoking guix package}).
21312 @node Security Updates
21313 @section Security Updates
21315 @cindex security updates
21316 @cindex security vulnerabilities
21317 Occasionally, important security vulnerabilities are discovered in software
21318 packages and must be patched. Guix developers try hard to keep track of
21319 known vulnerabilities and to apply fixes as soon as possible in the
21320 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
21321 containing only security updates.) The @command{guix lint} tool helps
21322 developers find out about vulnerable versions of software packages in the
21327 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
21328 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
21329 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
21333 @xref{Invoking guix lint}, for more information.
21336 As of version @value{VERSION}, the feature described below is considered
21340 Guix follows a functional
21341 package management discipline (@pxref{Introduction}), which implies
21342 that, when a package is changed, @emph{every package that depends on it}
21343 must be rebuilt. This can significantly slow down the deployment of
21344 fixes in core packages such as libc or Bash, since basically the whole
21345 distribution would need to be rebuilt. Using pre-built binaries helps
21346 (@pxref{Substitutes}), but deployment may still take more time than
21350 To address this, Guix implements @dfn{grafts}, a mechanism that allows
21351 for fast deployment of critical updates without the costs associated
21352 with a whole-distribution rebuild. The idea is to rebuild only the
21353 package that needs to be patched, and then to ``graft'' it onto packages
21354 explicitly installed by the user and that were previously referring to
21355 the original package. The cost of grafting is typically very low, and
21356 order of magnitudes lower than a full rebuild of the dependency chain.
21358 @cindex replacements of packages, for grafts
21359 For instance, suppose a security update needs to be applied to Bash.
21360 Guix developers will provide a package definition for the ``fixed''
21361 Bash, say @var{bash-fixed}, in the usual way (@pxref{Defining
21362 Packages}). Then, the original package definition is augmented with a
21363 @code{replacement} field pointing to the package containing the bug fix:
21370 (replacement bash-fixed)))
21373 From there on, any package depending directly or indirectly on Bash---as
21374 reported by @command{guix gc --requisites} (@pxref{Invoking guix
21375 gc})---that is installed is automatically ``rewritten'' to refer to
21376 @var{bash-fixed} instead of @var{bash}. This grafting process takes
21377 time proportional to the size of the package, usually less than a
21378 minute for an ``average'' package on a recent machine. Grafting is
21379 recursive: when an indirect dependency requires grafting, then grafting
21380 ``propagates'' up to the package that the user is installing.
21382 Currently, the length of the name and version of the graft and that of
21383 the package it replaces (@var{bash-fixed} and @var{bash} in the example
21384 above) must be equal. This restriction mostly comes from the fact that
21385 grafting works by patching files, including binary files, directly.
21386 Other restrictions may apply: for instance, when adding a graft to a
21387 package providing a shared library, the original shared library and its
21388 replacement must have the same @code{SONAME} and be binary-compatible.
21390 The @option{--no-grafts} command-line option allows you to forcefully
21391 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
21395 guix build bash --no-grafts
21399 returns the store file name of the original Bash, whereas:
21406 returns the store file name of the ``fixed'', replacement Bash. This
21407 allows you to distinguish between the two variants of Bash.
21409 To verify which Bash your whole profile refers to, you can run
21410 (@pxref{Invoking guix gc}):
21413 guix gc -R `readlink -f ~/.guix-profile` | grep bash
21417 @dots{} and compare the store file names that you get with those above.
21418 Likewise for a complete GuixSD system generation:
21421 guix gc -R `guix system build my-config.scm` | grep bash
21424 Lastly, to check which Bash running processes are using, you can use the
21425 @command{lsof} command:
21428 lsof | grep /gnu/store/.*bash
21432 @node Package Modules
21433 @section Package Modules
21435 From a programming viewpoint, the package definitions of the
21436 GNU distribution are provided by Guile modules in the @code{(gnu packages
21437 @dots{})} name space@footnote{Note that packages under the @code{(gnu
21438 packages @dots{})} module name space are not necessarily ``GNU
21439 packages''. This module naming scheme follows the usual Guile module
21440 naming convention: @code{gnu} means that these modules are distributed
21441 as part of the GNU system, and @code{packages} identifies modules that
21442 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
21443 Reference Manual}). For instance, the @code{(gnu packages emacs)}
21444 module exports a variable named @code{emacs}, which is bound to a
21445 @code{<package>} object (@pxref{Defining Packages}).
21447 The @code{(gnu packages @dots{})} module name space is
21448 automatically scanned for packages by the command-line tools. For
21449 instance, when running @code{guix package -i emacs}, all the @code{(gnu
21450 packages @dots{})} modules are scanned until one that exports a package
21451 object whose name is @code{emacs} is found. This package search
21452 facility is implemented in the @code{(gnu packages)} module.
21454 @cindex customization, of packages
21455 @cindex package module search path
21456 Users can store package definitions in modules with different
21457 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
21458 name and module name must match. For instance, the @code{(my-packages
21459 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
21460 relative to the load path specified with @option{--load-path} or
21461 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
21462 guile, GNU Guile Reference Manual}, for details.}. These package definitions
21463 will not be visible by default. Users can invoke commands such as
21464 @command{guix package} and @command{guix build} with the
21465 @code{-e} option so that they know where to find the package. Better
21466 yet, they can use the
21467 @code{-L} option of these commands to make those modules visible
21468 (@pxref{Invoking guix build, @code{--load-path}}), or define the
21469 @code{GUIX_PACKAGE_PATH} environment variable. This environment
21470 variable makes it easy to extend or customize the distribution and is
21471 honored by all the user interfaces.
21473 @defvr {Environment Variable} GUIX_PACKAGE_PATH
21474 This is a colon-separated list of directories to search for additional
21475 package modules. Directories listed in this variable take precedence
21476 over the own modules of the distribution.
21479 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
21480 each package is built based solely on other packages in the
21481 distribution. The root of this dependency graph is a small set of
21482 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
21483 bootstrap)} module. For more information on bootstrapping,
21484 @pxref{Bootstrapping}.
21486 @node Packaging Guidelines
21487 @section Packaging Guidelines
21489 @cindex packages, creating
21490 The GNU distribution is nascent and may well lack some of your favorite
21491 packages. This section describes how you can help make the distribution
21492 grow. @xref{Contributing}, for additional information on how you can
21495 Free software packages are usually distributed in the form of
21496 @dfn{source code tarballs}---typically @file{tar.gz} files that contain
21497 all the source files. Adding a package to the distribution means
21498 essentially two things: adding a @dfn{recipe} that describes how to
21499 build the package, including a list of other packages required to build
21500 it, and adding @dfn{package metadata} along with that recipe, such as a
21501 description and licensing information.
21503 In Guix all this information is embodied in @dfn{package definitions}.
21504 Package definitions provide a high-level view of the package. They are
21505 written using the syntax of the Scheme programming language; in fact,
21506 for each package we define a variable bound to the package definition,
21507 and export that variable from a module (@pxref{Package Modules}).
21508 However, in-depth Scheme knowledge is @emph{not} a prerequisite for
21509 creating packages. For more information on package definitions,
21510 @pxref{Defining Packages}.
21512 Once a package definition is in place, stored in a file in the Guix
21513 source tree, it can be tested using the @command{guix build} command
21514 (@pxref{Invoking guix build}). For example, assuming the new package is
21515 called @code{gnew}, you may run this command from the Guix build tree
21516 (@pxref{Running Guix Before It Is Installed}):
21519 ./pre-inst-env guix build gnew --keep-failed
21522 Using @code{--keep-failed} makes it easier to debug build failures since
21523 it provides access to the failed build tree. Another useful
21524 command-line option when debugging is @code{--log-file}, to access the
21527 If the package is unknown to the @command{guix} command, it may be that
21528 the source file contains a syntax error, or lacks a @code{define-public}
21529 clause to export the package variable. To figure it out, you may load
21530 the module from Guile to get more information about the actual error:
21533 ./pre-inst-env guile -c '(use-modules (gnu packages gnew))'
21536 Once your package builds correctly, please send us a patch
21537 (@pxref{Contributing}). Well, if you need help, we will be happy to
21538 help you too. Once the patch is committed in the Guix repository, the
21539 new package automatically gets built on the supported platforms by
21540 @url{http://hydra.gnu.org/jobset/gnu/master, our continuous integration
21543 @cindex substituter
21544 Users can obtain the new package definition simply by running
21545 @command{guix pull} (@pxref{Invoking guix pull}). When
21546 @code{hydra.gnu.org} is done building the package, installing the
21547 package automatically downloads binaries from there
21548 (@pxref{Substitutes}). The only place where human intervention is
21549 needed is to review and apply the patch.
21553 * Software Freedom:: What may go into the distribution.
21554 * Package Naming:: What's in a name?
21555 * Version Numbers:: When the name is not enough.
21556 * Synopses and Descriptions:: Helping users find the right package.
21557 * Python Modules:: A touch of British comedy.
21558 * Perl Modules:: Little pearls.
21559 * Java Packages:: Coffee break.
21560 * Fonts:: Fond of fonts.
21563 @node Software Freedom
21564 @subsection Software Freedom
21566 @c Adapted from http://www.gnu.org/philosophy/philosophy.html.
21567 @cindex free software
21568 The GNU operating system has been developed so that users can have
21569 freedom in their computing. GNU is @dfn{free software}, meaning that
21570 users have the @url{http://www.gnu.org/philosophy/free-sw.html,four
21571 essential freedoms}: to run the program, to study and change the program
21572 in source code form, to redistribute exact copies, and to distribute
21573 modified versions. Packages found in the GNU distribution provide only
21574 software that conveys these four freedoms.
21576 In addition, the GNU distribution follow the
21577 @url{http://www.gnu.org/distros/free-system-distribution-guidelines.html,free
21578 software distribution guidelines}. Among other things, these guidelines
21579 reject non-free firmware, recommendations of non-free software, and
21580 discuss ways to deal with trademarks and patents.
21582 Some otherwise free upstream package sources contain a small and optional
21583 subset that violates the above guidelines, for instance because this subset
21584 is itself non-free code. When that happens, the offending items are removed
21585 with appropriate patches or code snippets in the @code{origin} form of the
21586 package (@pxref{Defining Packages}). This way, @code{guix
21587 build --source} returns the ``freed'' source rather than the unmodified
21591 @node Package Naming
21592 @subsection Package Naming
21594 @cindex package name
21595 A package has actually two names associated with it:
21596 First, there is the name of the @emph{Scheme variable}, the one following
21597 @code{define-public}. By this name, the package can be made known in the
21598 Scheme code, for instance as input to another package. Second, there is
21599 the string in the @code{name} field of a package definition. This name
21600 is used by package management commands such as
21601 @command{guix package} and @command{guix build}.
21603 Both are usually the same and correspond to the lowercase conversion of
21604 the project name chosen upstream, with underscores replaced with
21605 hyphens. For instance, GNUnet is available as @code{gnunet}, and
21606 SDL_net as @code{sdl-net}.
21608 We do not add @code{lib} prefixes for library packages, unless these are
21609 already part of the official project name. But @pxref{Python
21610 Modules} and @ref{Perl Modules} for special rules concerning modules for
21611 the Python and Perl languages.
21613 Font package names are handled differently, @pxref{Fonts}.
21616 @node Version Numbers
21617 @subsection Version Numbers
21619 @cindex package version
21620 We usually package only the latest version of a given free software
21621 project. But sometimes, for instance for incompatible library versions,
21622 two (or more) versions of the same package are needed. These require
21623 different Scheme variable names. We use the name as defined
21624 in @ref{Package Naming}
21625 for the most recent version; previous versions use the same name, suffixed
21626 by @code{-} and the smallest prefix of the version number that may
21627 distinguish the two versions.
21629 The name inside the package definition is the same for all versions of a
21630 package and does not contain any version number.
21632 For instance, the versions 2.24.20 and 3.9.12 of GTK+ may be packaged as follows:
21635 (define-public gtk+
21640 (define-public gtk+-2
21643 (version "2.24.20")
21646 If we also wanted GTK+ 3.8.2, this would be packaged as
21648 (define-public gtk+-3.8
21655 @c See <https://lists.gnu.org/archive/html/guix-devel/2016-01/msg00425.html>,
21656 @c for a discussion of what follows.
21657 @cindex version number, for VCS snapshots
21658 Occasionally, we package snapshots of upstream's version control system
21659 (VCS) instead of formal releases. This should remain exceptional,
21660 because it is up to upstream developers to clarify what the stable
21661 release is. Yet, it is sometimes necessary. So, what should we put in
21662 the @code{version} field?
21664 Clearly, we need to make the commit identifier of the VCS snapshot
21665 visible in the version string, but we also need to make sure that the
21666 version string is monotonically increasing so that @command{guix package
21667 --upgrade} can determine which version is newer. Since commit
21668 identifiers, notably with Git, are not monotonically increasing, we add
21669 a revision number that we increase each time we upgrade to a newer
21670 snapshot. The resulting version string looks like this:
21675 | | `-- upstream commit ID
21677 | `--- Guix package revision
21679 latest upstream version
21682 It is a good idea to strip commit identifiers in the @code{version}
21683 field to, say, 7 digits. It avoids an aesthetic annoyance (assuming
21684 aesthetics have a role to play here) as well as problems related to OS
21685 limits such as the maximum shebang length (127 bytes for the Linux
21686 kernel.) It is best to use the full commit identifiers in
21687 @code{origin}s, though, to avoid ambiguities. A typical package
21688 definition may look like this:
21692 (let ((commit "c3f29bc928d5900971f65965feaae59e1272a3f7")
21693 (revision "1")) ;Guix package revision
21695 (version (git-version "0.9" revision commit))
21698 (uri (git-reference
21699 (url "git://example.org/my-package.git")
21701 (sha256 (base32 "1mbikn@dots{}"))
21702 (file-name (git-file-name name version))))
21707 @node Synopses and Descriptions
21708 @subsection Synopses and Descriptions
21710 @cindex package description
21711 @cindex package synopsis
21712 As we have seen before, each package in GNU@tie{}Guix includes a
21713 synopsis and a description (@pxref{Defining Packages}). Synopses and
21714 descriptions are important: They are what @command{guix package
21715 --search} searches, and a crucial piece of information to help users
21716 determine whether a given package suits their needs. Consequently,
21717 packagers should pay attention to what goes into them.
21719 Synopses must start with a capital letter and must not end with a
21720 period. They must not start with ``a'' or ``the'', which usually does
21721 not bring anything; for instance, prefer ``File-frobbing tool'' over ``A
21722 tool that frobs files''. The synopsis should say what the package
21723 is---e.g., ``Core GNU utilities (file, text, shell)''---or what it is
21724 used for---e.g., the synopsis for GNU@tie{}grep is ``Print lines
21725 matching a pattern''.
21727 Keep in mind that the synopsis must be meaningful for a very wide
21728 audience. For example, ``Manipulate alignments in the SAM format''
21729 might make sense for a seasoned bioinformatics researcher, but might be
21730 fairly unhelpful or even misleading to a non-specialized audience. It
21731 is a good idea to come up with a synopsis that gives an idea of the
21732 application domain of the package. In this example, this might give
21733 something like ``Manipulate nucleotide sequence alignments'', which
21734 hopefully gives the user a better idea of whether this is what they are
21737 Descriptions should take between five and ten lines. Use full
21738 sentences, and avoid using acronyms without first introducing them.
21739 Please avoid marketing phrases such as ``world-leading'',
21740 ``industrial-strength'', and ``next-generation'', and avoid superlatives
21741 like ``the most advanced''---they are not helpful to users looking for a
21742 package and may even sound suspicious. Instead, try to be factual,
21743 mentioning use cases and features.
21745 @cindex Texinfo markup, in package descriptions
21746 Descriptions can include Texinfo markup, which is useful to introduce
21747 ornaments such as @code{@@code} or @code{@@dfn}, bullet lists, or
21748 hyperlinks (@pxref{Overview,,, texinfo, GNU Texinfo}). However you
21749 should be careful when using some characters for example @samp{@@} and
21750 curly braces which are the basic special characters in Texinfo
21751 (@pxref{Special Characters,,, texinfo, GNU Texinfo}). User interfaces
21752 such as @command{guix package --show} take care of rendering it
21755 Synopses and descriptions are translated by volunteers
21756 @uref{http://translationproject.org/domain/guix-packages.html, at the
21757 Translation Project} so that as many users as possible can read them in
21758 their native language. User interfaces search them and display them in
21759 the language specified by the current locale.
21761 To allow @command{xgettext} to extract them as translatable strings,
21762 synopses and descriptions @emph{must be literal strings}. This means
21763 that you cannot use @code{string-append} or @code{format} to construct
21769 (synopsis "This is translatable")
21770 (description (string-append "This is " "*not*" " translatable.")))
21773 Translation is a lot of work so, as a packager, please pay even more
21774 attention to your synopses and descriptions as every change may entail
21775 additional work for translators. In order to help them, it is possible
21776 to make recommendations or instructions visible to them by inserting
21777 special comments like this (@pxref{xgettext Invocation,,, gettext, GNU
21781 ;; TRANSLATORS: "X11 resize-and-rotate" should not be translated.
21782 (description "ARandR is designed to provide a simple visual front end
21783 for the X11 resize-and-rotate (RandR) extension. @dots{}")
21787 @node Python Modules
21788 @subsection Python Modules
21791 We currently package Python 2 and Python 3, under the Scheme variable names
21792 @code{python-2} and @code{python} as explained in @ref{Version Numbers}.
21793 To avoid confusion and naming clashes with other programming languages, it
21794 seems desirable that the name of a package for a Python module contains
21795 the word @code{python}.
21797 Some modules are compatible with only one version of Python, others with both.
21798 If the package Foo compiles only with Python 3, we name it
21799 @code{python-foo}; if it compiles only with Python 2, we name it
21800 @code{python2-foo}. If it is compatible with both versions, we create two
21801 packages with the corresponding names.
21803 If a project already contains the word @code{python}, we drop this;
21804 for instance, the module python-dateutil is packaged under the names
21805 @code{python-dateutil} and @code{python2-dateutil}. If the project name
21806 starts with @code{py} (e.g. @code{pytz}), we keep it and prefix it as
21809 @subsubsection Specifying Dependencies
21810 @cindex inputs, for Python packages
21812 Dependency information for Python packages is usually available in the
21813 package source tree, with varying degrees of accuracy: in the
21814 @file{setup.py} file, in @file{requirements.txt}, or in @file{tox.ini}.
21816 Your mission, when writing a recipe for a Python package, is to map
21817 these dependencies to the appropriate type of ``input'' (@pxref{package
21818 Reference, inputs}). Although the @code{pypi} importer normally does a
21819 good job (@pxref{Invoking guix import}), you may want to check the
21820 following check list to determine which dependency goes where.
21825 We currently package Python 2 with @code{setuptools} and @code{pip}
21826 installed like Python 3.4 has per default. Thus you don't need to
21827 specify either of these as an input. @command{guix lint} will warn you
21831 Python dependencies required at run time go into
21832 @code{propagated-inputs}. They are typically defined with the
21833 @code{install_requires} keyword in @file{setup.py}, or in the
21834 @file{requirements.txt} file.
21837 Python packages required only at build time---e.g., those listed with
21838 the @code{setup_requires} keyword in @file{setup.py}---or only for
21839 testing---e.g., those in @code{tests_require}---go into
21840 @code{native-inputs}. The rationale is that (1) they do not need to be
21841 propagated because they are not needed at run time, and (2) in a
21842 cross-compilation context, it's the ``native'' input that we'd want.
21844 Examples are the @code{pytest}, @code{mock}, and @code{nose} test
21845 frameworks. Of course if any of these packages is also required at
21846 run-time, it needs to go to @code{propagated-inputs}.
21849 Anything that does not fall in the previous categories goes to
21850 @code{inputs}, for example programs or C libraries required for building
21851 Python packages containing C extensions.
21854 If a Python package has optional dependencies (@code{extras_require}),
21855 it is up to you to decide whether to add them or not, based on their
21856 usefulness/overhead ratio (@pxref{Submitting Patches, @command{guix
21863 @subsection Perl Modules
21866 Perl programs standing for themselves are named as any other package,
21867 using the lowercase upstream name.
21868 For Perl packages containing a single class, we use the lowercase class name,
21869 replace all occurrences of @code{::} by dashes and prepend the prefix
21871 So the class @code{XML::Parser} becomes @code{perl-xml-parser}.
21872 Modules containing several classes keep their lowercase upstream name and
21873 are also prepended by @code{perl-}. Such modules tend to have the word
21874 @code{perl} somewhere in their name, which gets dropped in favor of the
21875 prefix. For instance, @code{libwww-perl} becomes @code{perl-libwww}.
21878 @node Java Packages
21879 @subsection Java Packages
21882 Java programs standing for themselves are named as any other package,
21883 using the lowercase upstream name.
21885 To avoid confusion and naming clashes with other programming languages,
21886 it is desirable that the name of a package for a Java package is
21887 prefixed with @code{java-}. If a project already contains the word
21888 @code{java}, we drop this; for instance, the package @code{ngsjava} is
21889 packaged under the name @code{java-ngs}.
21891 For Java packages containing a single class or a small class hierarchy,
21892 we use the lowercase class name, replace all occurrences of @code{.} by
21893 dashes and prepend the prefix @code{java-}. So the class
21894 @code{apache.commons.cli} becomes package
21895 @code{java-apache-commons-cli}.
21902 For fonts that are in general not installed by a user for typesetting
21903 purposes, or that are distributed as part of a larger software package,
21904 we rely on the general packaging rules for software; for instance, this
21905 applies to the fonts delivered as part of the X.Org system or fonts that
21906 are part of TeX Live.
21908 To make it easier for a user to search for fonts, names for other packages
21909 containing only fonts are constructed as follows, independently of the
21910 upstream package name.
21912 The name of a package containing only one font family starts with
21913 @code{font-}; it is followed by the foundry name and a dash @code{-}
21914 if the foundry is known, and the font family name, in which spaces are
21915 replaced by dashes (and as usual, all upper case letters are transformed
21917 For example, the Gentium font family by SIL is packaged under the name
21918 @code{font-sil-gentium}.
21920 For a package containing several font families, the name of the collection
21921 is used in the place of the font family name.
21922 For instance, the Liberation fonts consist of three families,
21923 Liberation Sans, Liberation Serif and Liberation Mono.
21924 These could be packaged separately under the names
21925 @code{font-liberation-sans} and so on; but as they are distributed together
21926 under a common name, we prefer to package them together as
21927 @code{font-liberation}.
21929 In the case where several formats of the same font family or font collection
21930 are packaged separately, a short form of the format, prepended by a dash,
21931 is added to the package name. We use @code{-ttf} for TrueType fonts,
21932 @code{-otf} for OpenType fonts and @code{-type1} for PostScript Type 1
21937 @node Bootstrapping
21938 @section Bootstrapping
21940 @c Adapted from the ELS 2013 paper.
21942 @cindex bootstrapping
21944 Bootstrapping in our context refers to how the distribution gets built
21945 ``from nothing''. Remember that the build environment of a derivation
21946 contains nothing but its declared inputs (@pxref{Introduction}). So
21947 there's an obvious chicken-and-egg problem: how does the first package
21948 get built? How does the first compiler get compiled? Note that this is
21949 a question of interest only to the curious hacker, not to the regular
21950 user, so you can shamelessly skip this section if you consider yourself
21951 a ``regular user''.
21953 @cindex bootstrap binaries
21954 The GNU system is primarily made of C code, with libc at its core. The
21955 GNU build system itself assumes the availability of a Bourne shell and
21956 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
21957 `grep'. Furthermore, build programs---programs that run
21958 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
21959 (@pxref{Derivations}). Consequently, to be able to build anything at
21960 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
21961 Binutils, libc, and the other packages mentioned above---the
21962 @dfn{bootstrap binaries}.
21964 These bootstrap binaries are ``taken for granted'', though we can also
21965 re-create them if needed (more on that later).
21967 @unnumberedsubsec Preparing to Use the Bootstrap Binaries
21969 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
21970 @c large image, it's hard to scroll. Oh well.
21971 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
21973 The figure above shows the very beginning of the dependency graph of the
21974 distribution, corresponding to the package definitions of the @code{(gnu
21975 packages bootstrap)} module. A similar figure can be generated with
21976 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
21979 guix graph -t derivation \
21980 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
21984 At this level of detail, things are
21985 slightly complex. First, Guile itself consists of an ELF executable,
21986 along with many source and compiled Scheme files that are dynamically
21987 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
21988 tarball shown in this graph. This tarball is part of Guix's ``source''
21989 distribution, and gets inserted into the store with @code{add-to-store}
21990 (@pxref{The Store}).
21992 But how do we write a derivation that unpacks this tarball and adds it
21993 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
21994 derivation---the first one that gets built---uses @code{bash} as its
21995 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
21996 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
21997 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
21998 the Guix source distribution, whose sole purpose is to allow the Guile
21999 tarball to be unpacked.
22001 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
22002 Guile that can be used to run subsequent build programs. Its first task
22003 is to download tarballs containing the other pre-built binaries---this
22004 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
22005 @code{ftp-client.scm} are used for this purpose. The
22006 @code{module-import.drv} derivations import those modules in a directory
22007 in the store, using the original layout. The
22008 @code{module-import-compiled.drv} derivations compile those modules, and
22009 write them in an output directory with the right layout. This
22010 corresponds to the @code{#:modules} argument of
22011 @code{build-expression->derivation} (@pxref{Derivations}).
22013 Finally, the various tarballs are unpacked by the
22014 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
22015 etc., at which point we have a working C tool chain.
22018 @unnumberedsubsec Building the Build Tools
22020 Bootstrapping is complete when we have a full tool chain that does not
22021 depend on the pre-built bootstrap tools discussed above. This
22022 no-dependency requirement is verified by checking whether the files of
22023 the final tool chain contain references to the @file{/gnu/store}
22024 directories of the bootstrap inputs. The process that leads to this
22025 ``final'' tool chain is described by the package definitions found in
22026 the @code{(gnu packages commencement)} module.
22028 The @command{guix graph} command allows us to ``zoom out'' compared to
22029 the graph above, by looking at the level of package objects instead of
22030 individual derivations---remember that a package may translate to
22031 several derivations, typically one derivation to download its source,
22032 one to build the Guile modules it needs, and one to actually build the
22033 package from source. The command:
22036 guix graph -t bag \
22037 -e '(@@@@ (gnu packages commencement)
22038 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
22042 produces the dependency graph leading to the ``final'' C
22043 library@footnote{You may notice the @code{glibc-intermediate} label,
22044 suggesting that it is not @emph{quite} final, but as a good
22045 approximation, we will consider it final.}, depicted below.
22047 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
22049 @c See <http://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
22050 The first tool that gets built with the bootstrap binaries is
22051 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
22052 for all the following packages. From there Findutils and Diffutils get
22055 Then come the first-stage Binutils and GCC, built as pseudo cross
22056 tools---i.e., with @code{--target} equal to @code{--host}. They are
22057 used to build libc. Thanks to this cross-build trick, this libc is
22058 guaranteed not to hold any reference to the initial tool chain.
22060 From there the final Binutils and GCC (not shown above) are built.
22062 from the final Binutils, and links programs against the just-built libc.
22063 This tool chain is used to build the other packages used by Guix and by
22064 the GNU Build System: Guile, Bash, Coreutils, etc.
22066 And voilà! At this point we have the complete set of build tools that
22067 the GNU Build System expects. These are in the @code{%final-inputs}
22068 variable of the @code{(gnu packages commencement)} module, and are
22069 implicitly used by any package that uses @code{gnu-build-system}
22070 (@pxref{Build Systems, @code{gnu-build-system}}).
22073 @unnumberedsubsec Building the Bootstrap Binaries
22075 @cindex bootstrap binaries
22076 Because the final tool chain does not depend on the bootstrap binaries,
22077 those rarely need to be updated. Nevertheless, it is useful to have an
22078 automated way to produce them, should an update occur, and this is what
22079 the @code{(gnu packages make-bootstrap)} module provides.
22081 The following command builds the tarballs containing the bootstrap
22082 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
22083 of Coreutils and other basic command-line tools):
22086 guix build bootstrap-tarballs
22089 The generated tarballs are those that should be referred to in the
22090 @code{(gnu packages bootstrap)} module mentioned at the beginning of
22093 Still here? Then perhaps by now you've started to wonder: when do we
22094 reach a fixed point? That is an interesting question! The answer is
22095 unknown, but if you would like to investigate further (and have
22096 significant computational and storage resources to do so), then let us
22099 @unnumberedsubsec Reducing the Set of Bootstrap Binaries
22101 Our bootstrap binaries currently include GCC, Guile, etc. That's a lot
22102 of binary code! Why is that a problem? It's a problem because these
22103 big chunks of binary code are practically non-auditable, which makes it
22104 hard to establish what source code produced them. Every unauditable
22105 binary also leaves us vulnerable to compiler backdoors as described by
22106 Ken Thompson in the 1984 paper @emph{Reflections on Trusting Trust}.
22108 This is mitigated by the fact that our bootstrap binaries were generated
22109 from an earlier Guix revision. Nevertheless it lacks the level of
22110 transparency that we get in the rest of the package dependency graph,
22111 where Guix always gives us a source-to-binary mapping. Thus, our goal
22112 is to reduce the set of bootstrap binaries to the bare minimum.
22114 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
22115 on-going projects to do that. One of these is about replacing the
22116 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
22117 of increasing complexity, which could be built from source starting from
22118 a simple and auditable assembler. Your help is welcome!
22122 @section Porting to a New Platform
22124 As discussed above, the GNU distribution is self-contained, and
22125 self-containment is achieved by relying on pre-built ``bootstrap
22126 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
22127 operating system kernel, CPU architecture, and application binary
22128 interface (ABI). Thus, to port the distribution to a platform that is
22129 not yet supported, one must build those bootstrap binaries, and update
22130 the @code{(gnu packages bootstrap)} module to use them on that platform.
22132 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
22133 When everything goes well, and assuming the GNU tool chain supports the
22134 target platform, this can be as simple as running a command like this
22138 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
22141 For this to work, the @code{glibc-dynamic-linker} procedure in
22142 @code{(gnu packages bootstrap)} must be augmented to return the right
22143 file name for libc's dynamic linker on that platform; likewise,
22144 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
22145 taught about the new platform.
22147 Once these are built, the @code{(gnu packages bootstrap)} module needs
22148 to be updated to refer to these binaries on the target platform. That
22149 is, the hashes and URLs of the bootstrap tarballs for the new platform
22150 must be added alongside those of the currently supported platforms. The
22151 bootstrap Guile tarball is treated specially: it is expected to be
22152 available locally, and @file{gnu/local.mk} has rules do download it for
22153 the supported architectures; a rule for the new platform must be added
22156 In practice, there may be some complications. First, it may be that the
22157 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
22158 above) is not recognized by all the GNU tools. Typically, glibc
22159 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
22160 configure flag (see @code{gcc.scm} for examples of how to handle this).
22161 Second, some of the required packages could fail to build for that
22162 platform. Lastly, the generated binaries could be broken for some
22165 @c *********************************************************************
22166 @include contributing.texi
22168 @c *********************************************************************
22169 @node Acknowledgments
22170 @chapter Acknowledgments
22172 Guix is based on the @uref{http://nixos.org/nix/, Nix package manager},
22173 which was designed and
22174 implemented by Eelco Dolstra, with contributions from other people (see
22175 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
22176 management, and promoted unprecedented features, such as transactional
22177 package upgrades and rollbacks, per-user profiles, and referentially
22178 transparent build processes. Without this work, Guix would not exist.
22180 The Nix-based software distributions, Nixpkgs and NixOS, have also been
22181 an inspiration for Guix.
22183 GNU@tie{}Guix itself is a collective work with contributions from a
22184 number of people. See the @file{AUTHORS} file in Guix for more
22185 information on these fine people. The @file{THANKS} file lists people
22186 who have helped by reporting bugs, taking care of the infrastructure,
22187 providing artwork and themes, making suggestions, and more---thank you!
22190 @c *********************************************************************
22191 @node GNU Free Documentation License
22192 @appendix GNU Free Documentation License
22193 @cindex license, GNU Free Documentation License
22194 @include fdl-1.3.texi
22196 @c *********************************************************************
22197 @node Concept Index
22198 @unnumbered Concept Index
22201 @node Programming Index
22202 @unnumbered Programming Index
22203 @syncodeindex tp fn
22204 @syncodeindex vr fn
22209 @c Local Variables:
22210 @c ispell-local-dictionary: "american";