6 @documentencoding UTF-8
7 @settitle GNU Guix Reference Manual
12 @c Identifier of the OpenPGP key used to sign tarballs and such.
13 @set OPENPGP-SIGNING-KEY-ID 3CE464558A84FDC69DB40CFB090B11993D9AEBB5
16 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018 Ludovic Courtès@*
17 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
18 Copyright @copyright{} 2013 Nikita Karetnikov@*
19 Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
20 Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
21 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
22 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
23 Copyright @copyright{} 2015, 2016, 2017 Leo Famulari@*
24 Copyright @copyright{} 2015, 2016, 2017, 2018 Ricardo Wurmus@*
25 Copyright @copyright{} 2016 Ben Woodcroft@*
26 Copyright @copyright{} 2016, 2017, 2018 Chris Marusich@*
27 Copyright @copyright{} 2016, 2017, 2018 Efraim Flashner@*
28 Copyright @copyright{} 2016 John Darrington@*
29 Copyright @copyright{} 2016, 2017 Nils Gillmann@*
30 Copyright @copyright{} 2016, 2017 Jan Nieuwenhuizen@*
31 Copyright @copyright{} 2016 Julien Lepiller@*
32 Copyright @copyright{} 2016 Alex ter Weele@*
33 Copyright @copyright{} 2017, 2018 Clément Lassieur@*
34 Copyright @copyright{} 2017 Mathieu Othacehe@*
35 Copyright @copyright{} 2017 Federico Beffa@*
36 Copyright @copyright{} 2017 Carlo Zancanaro@*
37 Copyright @copyright{} 2017 Thomas Danckaert@*
38 Copyright @copyright{} 2017 humanitiesNerd@*
39 Copyright @copyright{} 2017 Christopher Allan Webber@*
40 Copyright @copyright{} 2017 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{~root/.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="`echo ~root`/.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.
2042 @cindex collisions, in a profile
2043 @cindex colliding packages in profiles
2044 @cindex profile collisions
2045 @item --allow-collisions
2046 Allow colliding packages in the new profile. Use at your own risk!
2048 By default, @command{guix package} reports as an error @dfn{collisions}
2049 in the profile. Collisions happen when two or more different versions
2050 or variants of a given package end up in the profile.
2053 Produce verbose output. In particular, emit the build log of the
2054 environment on the standard error port.
2057 Use the bootstrap Guile to build the profile. This option is only
2058 useful to distribution developers.
2062 In addition to these actions, @command{guix package} supports the
2063 following options to query the current state of a profile, or the
2064 availability of packages:
2068 @item --search=@var{regexp}
2069 @itemx -s @var{regexp}
2070 @cindex searching for packages
2071 List the available packages whose name, synopsis, or description matches
2072 @var{regexp}, sorted by relevance. Print all the metadata of matching packages in
2073 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
2074 GNU recutils manual}).
2076 This allows specific fields to be extracted using the @command{recsel}
2077 command, for instance:
2080 $ guix package -s malloc | recsel -p name,version,relevance
2094 Similarly, to show the name of all the packages available under the
2095 terms of the GNU@tie{}LGPL version 3:
2098 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
2105 It is also possible to refine search results using several @code{-s}
2106 flags. For example, the following command returns a list of board
2110 $ guix package -s '\<board\>' -s game | recsel -p name
2115 If we were to omit @code{-s game}, we would also get software packages
2116 that deal with printed circuit boards; removing the angle brackets
2117 around @code{board} would further add packages that have to do with
2120 And now for a more elaborate example. The following command searches
2121 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
2122 libraries, and prints the name and synopsis of the matching packages:
2125 $ guix package -s crypto -s library | \
2126 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
2130 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
2131 information on @dfn{selection expressions} for @code{recsel -e}.
2133 @item --show=@var{package}
2134 Show details about @var{package}, taken from the list of available packages, in
2135 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
2139 $ guix package --show=python | recsel -p name,version
2147 You may also specify the full name of a package to only get details about a
2148 specific version of it:
2150 $ guix package --show=python@@3.4 | recsel -p name,version
2157 @item --list-installed[=@var{regexp}]
2158 @itemx -I [@var{regexp}]
2159 List the currently installed packages in the specified profile, with the
2160 most recently installed packages shown last. When @var{regexp} is
2161 specified, list only installed packages whose name matches @var{regexp}.
2163 For each installed package, print the following items, separated by
2164 tabs: the package name, its version string, the part of the package that
2165 is installed (for instance, @code{out} for the default output,
2166 @code{include} for its headers, etc.), and the path of this package in
2169 @item --list-available[=@var{regexp}]
2170 @itemx -A [@var{regexp}]
2171 List packages currently available in the distribution for this system
2172 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
2173 installed packages whose name matches @var{regexp}.
2175 For each package, print the following items separated by tabs: its name,
2176 its version string, the parts of the package (@pxref{Packages with
2177 Multiple Outputs}), and the source location of its definition.
2179 @item --list-generations[=@var{pattern}]
2180 @itemx -l [@var{pattern}]
2182 Return a list of generations along with their creation dates; for each
2183 generation, show the installed packages, with the most recently
2184 installed packages shown last. Note that the zeroth generation is never
2187 For each installed package, print the following items, separated by
2188 tabs: the name of a package, its version string, the part of the package
2189 that is installed (@pxref{Packages with Multiple Outputs}), and the
2190 location of this package in the store.
2192 When @var{pattern} is used, the command returns only matching
2193 generations. Valid patterns include:
2196 @item @emph{Integers and comma-separated integers}. Both patterns denote
2197 generation numbers. For instance, @code{--list-generations=1} returns
2200 And @code{--list-generations=1,8,2} outputs three generations in the
2201 specified order. Neither spaces nor trailing commas are allowed.
2203 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
2204 specified generations and everything in between. Note that the start of
2205 a range must be smaller than its end.
2207 It is also possible to omit the endpoint. For example,
2208 @code{--list-generations=2..}, returns all generations starting from the
2211 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
2212 or months by passing an integer along with the first letter of the
2213 duration. For example, @code{--list-generations=20d} lists generations
2214 that are up to 20 days old.
2217 @item --delete-generations[=@var{pattern}]
2218 @itemx -d [@var{pattern}]
2219 When @var{pattern} is omitted, delete all generations except the current
2222 This command accepts the same patterns as @option{--list-generations}.
2223 When @var{pattern} is specified, delete the matching generations. When
2224 @var{pattern} specifies a duration, generations @emph{older} than the
2225 specified duration match. For instance, @code{--delete-generations=1m}
2226 deletes generations that are more than one month old.
2228 If the current generation matches, it is @emph{not} deleted. Also, the
2229 zeroth generation is never deleted.
2231 Note that deleting generations prevents rolling back to them.
2232 Consequently, this command must be used with care.
2236 Finally, since @command{guix package} may actually start build
2237 processes, it supports all the common build options (@pxref{Common Build
2238 Options}). It also supports package transformation options, such as
2239 @option{--with-source} (@pxref{Package Transformation Options}).
2240 However, note that package transformations are lost when upgrading; to
2241 preserve transformations across upgrades, you should define your own
2242 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
2243 (@pxref{Defining Packages}).
2246 @section Substitutes
2249 @cindex pre-built binaries
2250 Guix supports transparent source/binary deployment, which means that it
2251 can either build things locally, or download pre-built items from a
2252 server, or both. We call these pre-built items @dfn{substitutes}---they
2253 are substitutes for local build results. In many cases, downloading a
2254 substitute is much faster than building things locally.
2256 Substitutes can be anything resulting from a derivation build
2257 (@pxref{Derivations}). Of course, in the common case, they are
2258 pre-built package binaries, but source tarballs, for instance, which
2259 also result from derivation builds, can be available as substitutes.
2262 * Official Substitute Server:: One particular source of substitutes.
2263 * Substitute Server Authorization:: How to enable or disable substitutes.
2264 * Substitute Authentication:: How Guix verifies substitutes.
2265 * Proxy Settings:: How to get substitutes via proxy.
2266 * Substitution Failure:: What happens when substitution fails.
2267 * On Trusting Binaries:: How can you trust that binary blob?
2270 @node Official Substitute Server
2271 @subsection Official Substitute Server
2275 The @code{mirror.hydra.gnu.org} server is a front-end to an official build farm
2276 that builds packages from Guix continuously for some
2277 architectures, and makes them available as substitutes. This is the
2278 default source of substitutes; it can be overridden by passing the
2279 @option{--substitute-urls} option either to @command{guix-daemon}
2280 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
2281 or to client tools such as @command{guix package}
2282 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
2285 Substitute URLs can be either HTTP or HTTPS.
2286 HTTPS is recommended because communications are encrypted; conversely,
2287 using HTTP makes all communications visible to an eavesdropper, who
2288 could use the information gathered to determine, for instance, whether
2289 your system has unpatched security vulnerabilities.
2291 Substitutes from the official build farm are enabled by default when
2292 using the Guix System Distribution (@pxref{GNU Distribution}). However,
2293 they are disabled by default when using Guix on a foreign distribution,
2294 unless you have explicitly enabled them via one of the recommended
2295 installation steps (@pxref{Installation}). The following paragraphs
2296 describe how to enable or disable substitutes for the official build
2297 farm; the same procedure can also be used to enable substitutes for any
2298 other substitute server.
2300 @node Substitute Server Authorization
2301 @subsection Substitute Server Authorization
2304 @cindex substitutes, authorization thereof
2305 @cindex access control list (ACL), for substitutes
2306 @cindex ACL (access control list), for substitutes
2307 To allow Guix to download substitutes from @code{hydra.gnu.org} or a
2309 must add its public key to the access control list (ACL) of archive
2310 imports, using the @command{guix archive} command (@pxref{Invoking guix
2311 archive}). Doing so implies that you trust @code{hydra.gnu.org} to not
2312 be compromised and to serve genuine substitutes.
2314 The public key for @code{hydra.gnu.org} is installed along with Guix, in
2315 @code{@var{prefix}/share/guix/hydra.gnu.org.pub}, where @var{prefix} is
2316 the installation prefix of Guix. If you installed Guix from source,
2317 make sure you checked the GPG signature of
2318 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
2319 Then, you can run something like this:
2322 # guix archive --authorize < @var{prefix}/share/guix/hydra.gnu.org.pub
2326 Similarly, the @file{berlin.guixsd.org.pub} file contains the public key
2327 for the project's new build farm, reachable at
2328 @indicateurl{https://berlin.guixsd.org}.
2330 As of this writing @code{berlin.guixsd.org} is being upgraded so it can
2331 better scale up, but you might want to give it a try. It is backed by
2332 20 x86_64/i686 build nodes and may be able to provide substitutes more
2333 quickly than @code{mirror.hydra.gnu.org}.
2336 Once this is in place, the output of a command like @code{guix build}
2337 should change from something like:
2340 $ guix build emacs --dry-run
2341 The following derivations would be built:
2342 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
2343 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
2344 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
2345 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
2353 $ guix build emacs --dry-run
2354 112.3 MB would be downloaded:
2355 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
2356 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
2357 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
2358 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
2363 This indicates that substitutes from @code{hydra.gnu.org} are usable and
2364 will be downloaded, when possible, for future builds.
2366 @cindex substitutes, how to disable
2367 The substitute mechanism can be disabled globally by running
2368 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
2369 guix-daemon}). It can also be disabled temporarily by passing the
2370 @code{--no-substitutes} option to @command{guix package}, @command{guix
2371 build}, and other command-line tools.
2373 @node Substitute Authentication
2374 @subsection Substitute Authentication
2376 @cindex digital signatures
2377 Guix detects and raises an error when attempting to use a substitute
2378 that has been tampered with. Likewise, it ignores substitutes that are
2379 not signed, or that are not signed by one of the keys listed in the ACL.
2381 There is one exception though: if an unauthorized server provides
2382 substitutes that are @emph{bit-for-bit identical} to those provided by
2383 an authorized server, then the unauthorized server becomes eligible for
2384 downloads. For example, assume we have chosen two substitute servers
2388 --substitute-urls="https://a.example.org https://b.example.org"
2392 @cindex reproducible builds
2393 If the ACL contains only the key for @code{b.example.org}, and if
2394 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
2395 then Guix will download substitutes from @code{a.example.org} because it
2396 comes first in the list and can be considered a mirror of
2397 @code{b.example.org}. In practice, independent build machines usually
2398 produce the same binaries, thanks to bit-reproducible builds (see
2401 When using HTTPS, the server's X.509 certificate is @emph{not} validated
2402 (in other words, the server is not authenticated), contrary to what
2403 HTTPS clients such as Web browsers usually do. This is because Guix
2404 authenticates substitute information itself, as explained above, which
2405 is what we care about (whereas X.509 certificates are about
2406 authenticating bindings between domain names and public keys.)
2408 @node Proxy Settings
2409 @subsection Proxy Settings
2412 Substitutes are downloaded over HTTP or HTTPS.
2413 The @code{http_proxy} environment
2414 variable can be set in the environment of @command{guix-daemon} and is
2415 honored for downloads of substitutes. Note that the value of
2416 @code{http_proxy} in the environment where @command{guix build},
2417 @command{guix package}, and other client commands are run has
2418 @emph{absolutely no effect}.
2420 @node Substitution Failure
2421 @subsection Substitution Failure
2423 Even when a substitute for a derivation is available, sometimes the
2424 substitution attempt will fail. This can happen for a variety of
2425 reasons: the substitute server might be offline, the substitute may
2426 recently have been deleted, the connection might have been interrupted,
2429 When substitutes are enabled and a substitute for a derivation is
2430 available, but the substitution attempt fails, Guix will attempt to
2431 build the derivation locally depending on whether or not
2432 @code{--fallback} was given (@pxref{fallback-option,, common build
2433 option @code{--fallback}}). Specifically, if @code{--fallback} was
2434 omitted, then no local build will be performed, and the derivation is
2435 considered to have failed. However, if @code{--fallback} was given,
2436 then Guix will attempt to build the derivation locally, and the success
2437 or failure of the derivation depends on the success or failure of the
2438 local build. Note that when substitutes are disabled or no substitute
2439 is available for the derivation in question, a local build will
2440 @emph{always} be performed, regardless of whether or not
2441 @code{--fallback} was given.
2443 To get an idea of how many substitutes are available right now, you can
2444 try running the @command{guix weather} command (@pxref{Invoking guix
2445 weather}). This command provides statistics on the substitutes provided
2448 @node On Trusting Binaries
2449 @subsection On Trusting Binaries
2451 @cindex trust, of pre-built binaries
2452 Today, each individual's control over their own computing is at the
2453 mercy of institutions, corporations, and groups with enough power and
2454 determination to subvert the computing infrastructure and exploit its
2455 weaknesses. While using @code{hydra.gnu.org} substitutes can be
2456 convenient, we encourage users to also build on their own, or even run
2457 their own build farm, such that @code{hydra.gnu.org} is less of an
2458 interesting target. One way to help is by publishing the software you
2459 build using @command{guix publish} so that others have one more choice
2460 of server to download substitutes from (@pxref{Invoking guix publish}).
2462 Guix has the foundations to maximize build reproducibility
2463 (@pxref{Features}). In most cases, independent builds of a given
2464 package or derivation should yield bit-identical results. Thus, through
2465 a diverse set of independent package builds, we can strengthen the
2466 integrity of our systems. The @command{guix challenge} command aims to
2467 help users assess substitute servers, and to assist developers in
2468 finding out about non-deterministic package builds (@pxref{Invoking guix
2469 challenge}). Similarly, the @option{--check} option of @command{guix
2470 build} allows users to check whether previously-installed substitutes
2471 are genuine by rebuilding them locally (@pxref{build-check,
2472 @command{guix build --check}}).
2474 In the future, we want Guix to have support to publish and retrieve
2475 binaries to/from other users, in a peer-to-peer fashion. If you would
2476 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
2478 @node Packages with Multiple Outputs
2479 @section Packages with Multiple Outputs
2481 @cindex multiple-output packages
2482 @cindex package outputs
2485 Often, packages defined in Guix have a single @dfn{output}---i.e., the
2486 source package leads to exactly one directory in the store. When running
2487 @command{guix package -i glibc}, one installs the default output of the
2488 GNU libc package; the default output is called @code{out}, but its name
2489 can be omitted as shown in this command. In this particular case, the
2490 default output of @code{glibc} contains all the C header files, shared
2491 libraries, static libraries, Info documentation, and other supporting
2494 Sometimes it is more appropriate to separate the various types of files
2495 produced from a single source package into separate outputs. For
2496 instance, the GLib C library (used by GTK+ and related packages)
2497 installs more than 20 MiB of reference documentation as HTML pages.
2498 To save space for users who do not need it, the documentation goes to a
2499 separate output, called @code{doc}. To install the main GLib output,
2500 which contains everything but the documentation, one would run:
2503 guix package -i glib
2506 @cindex documentation
2507 The command to install its documentation is:
2510 guix package -i glib:doc
2513 Some packages install programs with different ``dependency footprints''.
2514 For instance, the WordNet package installs both command-line tools and
2515 graphical user interfaces (GUIs). The former depend solely on the C
2516 library, whereas the latter depend on Tcl/Tk and the underlying X
2517 libraries. In this case, we leave the command-line tools in the default
2518 output, whereas the GUIs are in a separate output. This allows users
2519 who do not need the GUIs to save space. The @command{guix size} command
2520 can help find out about such situations (@pxref{Invoking guix size}).
2521 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
2523 There are several such multiple-output packages in the GNU distribution.
2524 Other conventional output names include @code{lib} for libraries and
2525 possibly header files, @code{bin} for stand-alone programs, and
2526 @code{debug} for debugging information (@pxref{Installing Debugging
2527 Files}). The outputs of a packages are listed in the third column of
2528 the output of @command{guix package --list-available} (@pxref{Invoking
2532 @node Invoking guix gc
2533 @section Invoking @command{guix gc}
2535 @cindex garbage collector
2537 Packages that are installed, but not used, may be @dfn{garbage-collected}.
2538 The @command{guix gc} command allows users to explicitly run the garbage
2539 collector to reclaim space from the @file{/gnu/store} directory. It is
2540 the @emph{only} way to remove files from @file{/gnu/store}---removing
2541 files or directories manually may break it beyond repair!
2544 @cindex garbage collector roots
2545 The garbage collector has a set of known @dfn{roots}: any file under
2546 @file{/gnu/store} reachable from a root is considered @dfn{live} and
2547 cannot be deleted; any other file is considered @dfn{dead} and may be
2548 deleted. The set of garbage collector roots (``GC roots'' for short)
2549 includes default user profiles; by default, the symlinks under
2550 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
2551 added with @command{guix build --root}, for example (@pxref{Invoking
2554 Prior to running @code{guix gc --collect-garbage} to make space, it is
2555 often useful to remove old generations from user profiles; that way, old
2556 package builds referenced by those generations can be reclaimed. This
2557 is achieved by running @code{guix package --delete-generations}
2558 (@pxref{Invoking guix package}).
2560 Our recommendation is to run a garbage collection periodically, or when
2561 you are short on disk space. For instance, to guarantee that at least
2562 5@tie{}GB are available on your disk, simply run:
2568 It is perfectly safe to run as a non-interactive periodic job
2569 (@pxref{Scheduled Job Execution}, for how to set up such a job on
2570 GuixSD). Running @command{guix gc} with no arguments will collect as
2571 much garbage as it can, but that is often inconvenient: you may find
2572 yourself having to rebuild or re-download software that is ``dead'' from
2573 the GC viewpoint but that is necessary to build other pieces of
2574 software---e.g., the compiler tool chain.
2576 The @command{guix gc} command has three modes of operation: it can be
2577 used to garbage-collect any dead files (the default), to delete specific
2578 files (the @code{--delete} option), to print garbage-collector
2579 information, or for more advanced queries. The garbage collection
2580 options are as follows:
2583 @item --collect-garbage[=@var{min}]
2584 @itemx -C [@var{min}]
2585 Collect garbage---i.e., unreachable @file{/gnu/store} files and
2586 sub-directories. This is the default operation when no option is
2589 When @var{min} is given, stop once @var{min} bytes have been collected.
2590 @var{min} may be a number of bytes, or it may include a unit as a
2591 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
2592 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
2594 When @var{min} is omitted, collect all the garbage.
2596 @item --free-space=@var{free}
2597 @itemx -F @var{free}
2598 Collect garbage until @var{free} space is available under
2599 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
2600 as @code{500MiB}, as described above.
2602 When @var{free} or more is already available in @file{/gnu/store}, do
2603 nothing and exit immediately.
2607 Attempt to delete all the store files and directories specified as
2608 arguments. This fails if some of the files are not in the store, or if
2609 they are still live.
2611 @item --list-failures
2612 List store items corresponding to cached build failures.
2614 This prints nothing unless the daemon was started with
2615 @option{--cache-failures} (@pxref{Invoking guix-daemon,
2616 @option{--cache-failures}}).
2618 @item --clear-failures
2619 Remove the specified store items from the failed-build cache.
2621 Again, this option only makes sense when the daemon is started with
2622 @option{--cache-failures}. Otherwise, it does nothing.
2625 Show the list of dead files and directories still present in the
2626 store---i.e., files and directories no longer reachable from any root.
2629 Show the list of live store files and directories.
2633 In addition, the references among existing store files can be queried:
2639 @cindex package dependencies
2640 List the references (respectively, the referrers) of store files given
2646 List the requisites of the store files passed as arguments. Requisites
2647 include the store files themselves, their references, and the references
2648 of these, recursively. In other words, the returned list is the
2649 @dfn{transitive closure} of the store files.
2651 @xref{Invoking guix size}, for a tool to profile the size of the closure
2652 of an element. @xref{Invoking guix graph}, for a tool to visualize
2653 the graph of references.
2657 Return the derivation(s) leading to the given store items
2658 (@pxref{Derivations}).
2660 For example, this command:
2663 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
2667 returns the @file{.drv} file(s) leading to the @code{emacs} package
2668 installed in your profile.
2670 Note that there may be zero matching @file{.drv} files, for instance
2671 because these files have been garbage-collected. There can also be more
2672 than one matching @file{.drv} due to fixed-output derivations.
2675 Lastly, the following options allow you to check the integrity of the
2676 store and to control disk usage.
2680 @item --verify[=@var{options}]
2681 @cindex integrity, of the store
2682 @cindex integrity checking
2683 Verify the integrity of the store.
2685 By default, make sure that all the store items marked as valid in the
2686 database of the daemon actually exist in @file{/gnu/store}.
2688 When provided, @var{options} must be a comma-separated list containing one
2689 or more of @code{contents} and @code{repair}.
2691 When passing @option{--verify=contents}, the daemon computes the
2692 content hash of each store item and compares it against its hash in the
2693 database. Hash mismatches are reported as data corruptions. Because it
2694 traverses @emph{all the files in the store}, this command can take a
2695 long time, especially on systems with a slow disk drive.
2697 @cindex repairing the store
2698 @cindex corruption, recovering from
2699 Using @option{--verify=repair} or @option{--verify=contents,repair}
2700 causes the daemon to try to repair corrupt store items by fetching
2701 substitutes for them (@pxref{Substitutes}). Because repairing is not
2702 atomic, and thus potentially dangerous, it is available only to the
2703 system administrator. A lightweight alternative, when you know exactly
2704 which items in the store are corrupt, is @command{guix build --repair}
2705 (@pxref{Invoking guix build}).
2708 @cindex deduplication
2709 Optimize the store by hard-linking identical files---this is
2710 @dfn{deduplication}.
2712 The daemon performs deduplication after each successful build or archive
2713 import, unless it was started with @code{--disable-deduplication}
2714 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
2715 this option is primarily useful when the daemon was running with
2716 @code{--disable-deduplication}.
2720 @node Invoking guix pull
2721 @section Invoking @command{guix pull}
2723 @cindex upgrading Guix
2724 @cindex updating Guix
2725 @cindex @command{guix pull}
2727 Packages are installed or upgraded to the latest version available in
2728 the distribution currently available on your local machine. To update
2729 that distribution, along with the Guix tools, you must run @command{guix
2730 pull}: the command downloads the latest Guix source code and package
2731 descriptions, and deploys it. Source code is downloaded from a
2732 @uref{https://git-scm.com, Git} repository.
2734 On completion, @command{guix package} will use packages and package
2735 versions from this just-retrieved copy of Guix. Not only that, but all
2736 the Guix commands and Scheme modules will also be taken from that latest
2737 version. New @command{guix} sub-commands added by the update also
2740 Any user can update their Guix copy using @command{guix pull}, and the
2741 effect is limited to the user who run @command{guix pull}. For
2742 instance, when user @code{root} runs @command{guix pull}, this has no
2743 effect on the version of Guix that user @code{alice} sees, and vice
2744 versa@footnote{Under the hood, @command{guix pull} updates the
2745 @file{~/.config/guix/latest} symbolic link to point to the latest Guix,
2746 and the @command{guix} command loads code from there. Currently, the
2747 only way to roll back an invocation of @command{guix pull} is to
2748 manually update this symlink to point to the previous Guix.}.
2750 The @command{guix pull} command is usually invoked with no arguments,
2751 but it supports the following options:
2755 Produce verbose output, writing build logs to the standard error output.
2757 @item --url=@var{url}
2758 Download Guix from the Git repository at @var{url}.
2760 @vindex GUIX_PULL_URL
2761 By default, the source is taken from its canonical Git repository at
2762 @code{gnu.org}, for the stable branch of Guix. To use a different source,
2763 set the @code{GUIX_PULL_URL} environment variable.
2765 @item --commit=@var{commit}
2766 Deploy @var{commit}, a valid Git commit ID represented as a hexadecimal
2769 @item --branch=@var{branch}
2770 Deploy the tip of @var{branch}, the name of a Git branch available on
2771 the repository at @var{url}.
2774 Use the bootstrap Guile to build the latest Guix. This option is only
2775 useful to Guix developers.
2778 In addition, @command{guix pull} supports all the common build options
2779 (@pxref{Common Build Options}).
2781 @node Invoking guix pack
2782 @section Invoking @command{guix pack}
2784 Occasionally you want to pass software to people who are not (yet!)
2785 lucky enough to be using Guix. You'd tell them to run @command{guix
2786 package -i @var{something}}, but that's not possible in this case. This
2787 is where @command{guix pack} comes in.
2790 If you are looking for ways to exchange binaries among machines that
2791 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
2792 publish}, and @ref{Invoking guix archive}.
2797 @cindex application bundle
2798 @cindex software bundle
2799 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
2800 @dfn{software bundle}: it creates a tarball or some other archive
2801 containing the binaries of the software you're interested in, and all
2802 its dependencies. The resulting archive can be used on any machine that
2803 does not have Guix, and people can run the exact same binaries as those
2804 you have with Guix. The pack itself is created in a bit-reproducible
2805 fashion, so anyone can verify that it really contains the build results
2806 that you pretend to be shipping.
2808 For example, to create a bundle containing Guile, Emacs, Geiser, and all
2809 their dependencies, you can run:
2812 $ guix pack guile emacs geiser
2814 /gnu/store/@dots{}-pack.tar.gz
2817 The result here is a tarball containing a @file{/gnu/store} directory
2818 with all the relevant packages. The resulting tarball contains a
2819 @dfn{profile} with the three packages of interest; the profile is the
2820 same as would be created by @command{guix package -i}. It is this
2821 mechanism that is used to create Guix's own standalone binary tarball
2822 (@pxref{Binary Installation}).
2824 Users of this pack would have to run
2825 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
2826 find inconvenient. To work around it, you can create, say, a
2827 @file{/opt/gnu/bin} symlink to the profile:
2830 guix pack -S /opt/gnu/bin=bin guile emacs geiser
2834 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
2836 Alternatively, you can produce a pack in the Docker image format using
2837 the following command:
2840 guix pack -f docker guile emacs geiser
2844 The result is a tarball that can be passed to the @command{docker load}
2846 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
2847 documentation} for more information.
2849 Several command-line options allow you to customize your pack:
2852 @item --format=@var{format}
2853 @itemx -f @var{format}
2854 Produce a pack in the given @var{format}.
2856 The available formats are:
2860 This is the default format. It produces a tarball containing all the
2861 specified binaries and symlinks.
2864 This produces a tarball that follows the
2865 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
2866 Docker Image Specification}.
2869 @item --expression=@var{expr}
2870 @itemx -e @var{expr}
2871 Consider the package @var{expr} evaluates to.
2873 This has the same purpose as the same-named option in @command{guix
2874 build} (@pxref{Additional Build Options, @code{--expression} in
2875 @command{guix build}}).
2877 @item --manifest=@var{file}
2878 @itemx -m @var{file}
2879 Use the packages contained in the manifest object returned by the Scheme
2882 This has a similar purpose as the same-named option in @command{guix
2883 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
2884 same manifest files. It allows you to define a collection of packages
2885 once and use it both for creating profiles and for creating archives
2886 for use on machines that do not have Guix installed. Note that you can
2887 specify @emph{either} a manifest file @emph{or} a list of packages,
2890 @item --system=@var{system}
2891 @itemx -s @var{system}
2892 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
2893 the system type of the build host.
2895 @item --target=@var{triplet}
2896 @cindex cross-compilation
2897 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
2898 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
2899 configuration triplets,, autoconf, Autoconf}).
2901 @item --compression=@var{tool}
2902 @itemx -C @var{tool}
2903 Compress the resulting tarball using @var{tool}---one of @code{gzip},
2904 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
2906 @item --symlink=@var{spec}
2907 @itemx -S @var{spec}
2908 Add the symlinks specified by @var{spec} to the pack. This option can
2909 appear several times.
2911 @var{spec} has the form @code{@var{source}=@var{target}}, where
2912 @var{source} is the symlink that will be created and @var{target} is the
2915 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
2916 symlink pointing to the @file{bin} sub-directory of the profile.
2918 @item --localstatedir
2919 Include the ``local state directory'', @file{/var/guix}, in the
2922 @file{/var/guix} contains the store database (@pxref{The Store}) as well
2923 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
2924 the pack means that the store is ``complete'' and manageable by Guix;
2925 not providing it pack means that the store is ``dead'': items cannot be
2926 added to it or removed from it after extraction of the pack.
2928 One use case for this is the Guix self-contained binary tarball
2929 (@pxref{Binary Installation}).
2932 Use the bootstrap binaries to build the pack. This option is only
2933 useful to Guix developers.
2936 In addition, @command{guix pack} supports all the common build options
2937 (@pxref{Common Build Options}) and all the package transformation
2938 options (@pxref{Package Transformation Options}).
2941 @node Invoking guix archive
2942 @section Invoking @command{guix archive}
2944 @cindex @command{guix archive}
2946 The @command{guix archive} command allows users to @dfn{export} files
2947 from the store into a single archive, and to later @dfn{import} them on
2948 a machine that runs Guix.
2949 In particular, it allows store files to be transferred from one machine
2950 to the store on another machine.
2953 If you're looking for a way to produce archives in a format suitable for
2954 tools other than Guix, @pxref{Invoking guix pack}.
2957 @cindex exporting store items
2958 To export store files as an archive to standard output, run:
2961 guix archive --export @var{options} @var{specifications}...
2964 @var{specifications} may be either store file names or package
2965 specifications, as for @command{guix package} (@pxref{Invoking guix
2966 package}). For instance, the following command creates an archive
2967 containing the @code{gui} output of the @code{git} package and the main
2968 output of @code{emacs}:
2971 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
2974 If the specified packages are not built yet, @command{guix archive}
2975 automatically builds them. The build process may be controlled with the
2976 common build options (@pxref{Common Build Options}).
2978 To transfer the @code{emacs} package to a machine connected over SSH,
2982 guix archive --export -r emacs | ssh the-machine guix archive --import
2986 Similarly, a complete user profile may be transferred from one machine
2987 to another like this:
2990 guix archive --export -r $(readlink -f ~/.guix-profile) | \
2991 ssh the-machine guix-archive --import
2995 However, note that, in both examples, all of @code{emacs} and the
2996 profile as well as all of their dependencies are transferred (due to
2997 @code{-r}), regardless of what is already available in the store on the
2998 target machine. The @code{--missing} option can help figure out which
2999 items are missing from the target store. The @command{guix copy}
3000 command simplifies and optimizes this whole process, so this is probably
3001 what you should use in this case (@pxref{Invoking guix copy}).
3003 @cindex nar, archive format
3004 @cindex normalized archive (nar)
3005 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
3006 comparable in spirit to `tar', but with differences
3007 that make it more appropriate for our purposes. First, rather than
3008 recording all Unix metadata for each file, the nar format only mentions
3009 the file type (regular, directory, or symbolic link); Unix permissions
3010 and owner/group are dismissed. Second, the order in which directory
3011 entries are stored always follows the order of file names according to
3012 the C locale collation order. This makes archive production fully
3015 When exporting, the daemon digitally signs the contents of the archive,
3016 and that digital signature is appended. When importing, the daemon
3017 verifies the signature and rejects the import in case of an invalid
3018 signature or if the signing key is not authorized.
3019 @c FIXME: Add xref to daemon doc about signatures.
3021 The main options are:
3025 Export the specified store files or packages (see below.) Write the
3026 resulting archive to the standard output.
3028 Dependencies are @emph{not} included in the output, unless
3029 @code{--recursive} is passed.
3033 When combined with @code{--export}, this instructs @command{guix
3034 archive} to include dependencies of the given items in the archive.
3035 Thus, the resulting archive is self-contained: it contains the closure
3036 of the exported store items.
3039 Read an archive from the standard input, and import the files listed
3040 therein into the store. Abort if the archive has an invalid digital
3041 signature, or if it is signed by a public key not among the authorized
3042 keys (see @code{--authorize} below.)
3045 Read a list of store file names from the standard input, one per line,
3046 and write on the standard output the subset of these files missing from
3049 @item --generate-key[=@var{parameters}]
3050 @cindex signing, archives
3051 Generate a new key pair for the daemon. This is a prerequisite before
3052 archives can be exported with @code{--export}. Note that this operation
3053 usually takes time, because it needs to gather enough entropy to
3054 generate the key pair.
3056 The generated key pair is typically stored under @file{/etc/guix}, in
3057 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
3058 key, which must be kept secret.) When @var{parameters} is omitted,
3059 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
3060 versions before 1.6.0, it is a 4096-bit RSA key.
3061 Alternatively, @var{parameters} can specify
3062 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
3063 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
3064 Libgcrypt Reference Manual}).
3067 @cindex authorizing, archives
3068 Authorize imports signed by the public key passed on standard input.
3069 The public key must be in ``s-expression advanced format''---i.e., the
3070 same format as the @file{signing-key.pub} file.
3072 The list of authorized keys is kept in the human-editable file
3073 @file{/etc/guix/acl}. The file contains
3074 @url{http://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
3075 s-expressions''} and is structured as an access-control list in the
3076 @url{http://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
3079 @item --extract=@var{directory}
3080 @itemx -x @var{directory}
3081 Read a single-item archive as served by substitute servers
3082 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
3083 low-level operation needed in only very narrow use cases; see below.
3085 For example, the following command extracts the substitute for Emacs
3086 served by @code{hydra.gnu.org} to @file{/tmp/emacs}:
3090 https://hydra.gnu.org/nar/@dots{}-emacs-24.5 \
3091 | bunzip2 | guix archive -x /tmp/emacs
3094 Single-item archives are different from multiple-item archives produced
3095 by @command{guix archive --export}; they contain a single store item,
3096 and they do @emph{not} embed a signature. Thus this operation does
3097 @emph{no} signature verification and its output should be considered
3100 The primary purpose of this operation is to facilitate inspection of
3101 archive contents coming from possibly untrusted substitute servers.
3105 @c *********************************************************************
3106 @node Programming Interface
3107 @chapter Programming Interface
3109 GNU Guix provides several Scheme programming interfaces (APIs) to
3110 define, build, and query packages. The first interface allows users to
3111 write high-level package definitions. These definitions refer to
3112 familiar packaging concepts, such as the name and version of a package,
3113 its build system, and its dependencies. These definitions can then be
3114 turned into concrete build actions.
3116 Build actions are performed by the Guix daemon, on behalf of users. In a
3117 standard setup, the daemon has write access to the store---the
3118 @file{/gnu/store} directory---whereas users do not. The recommended
3119 setup also has the daemon perform builds in chroots, under a specific
3120 build users, to minimize interference with the rest of the system.
3123 Lower-level APIs are available to interact with the daemon and the
3124 store. To instruct the daemon to perform a build action, users actually
3125 provide it with a @dfn{derivation}. A derivation is a low-level
3126 representation of the build actions to be taken, and the environment in
3127 which they should occur---derivations are to package definitions what
3128 assembly is to C programs. The term ``derivation'' comes from the fact
3129 that build results @emph{derive} from them.
3131 This chapter describes all these APIs in turn, starting from high-level
3132 package definitions.
3135 * Defining Packages:: Defining new packages.
3136 * Build Systems:: Specifying how packages are built.
3137 * The Store:: Manipulating the package store.
3138 * Derivations:: Low-level interface to package derivations.
3139 * The Store Monad:: Purely functional interface to the store.
3140 * G-Expressions:: Manipulating build expressions.
3143 @node Defining Packages
3144 @section Defining Packages
3146 The high-level interface to package definitions is implemented in the
3147 @code{(guix packages)} and @code{(guix build-system)} modules. As an
3148 example, the package definition, or @dfn{recipe}, for the GNU Hello
3149 package looks like this:
3152 (define-module (gnu packages hello)
3153 #:use-module (guix packages)
3154 #:use-module (guix download)
3155 #:use-module (guix build-system gnu)
3156 #:use-module (guix licenses)
3157 #:use-module (gnu packages gawk))
3159 (define-public hello
3165 (uri (string-append "mirror://gnu/hello/hello-" version
3169 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
3170 (build-system gnu-build-system)
3171 (arguments '(#:configure-flags '("--enable-silent-rules")))
3172 (inputs `(("gawk" ,gawk)))
3173 (synopsis "Hello, GNU world: An example GNU package")
3174 (description "Guess what GNU Hello prints!")
3175 (home-page "http://www.gnu.org/software/hello/")
3180 Without being a Scheme expert, the reader may have guessed the meaning
3181 of the various fields here. This expression binds the variable
3182 @code{hello} to a @code{<package>} object, which is essentially a record
3183 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
3184 This package object can be inspected using procedures found in the
3185 @code{(guix packages)} module; for instance, @code{(package-name hello)}
3186 returns---surprise!---@code{"hello"}.
3188 With luck, you may be able to import part or all of the definition of
3189 the package you are interested in from another repository, using the
3190 @code{guix import} command (@pxref{Invoking guix import}).
3192 In the example above, @var{hello} is defined in a module of its own,
3193 @code{(gnu packages hello)}. Technically, this is not strictly
3194 necessary, but it is convenient to do so: all the packages defined in
3195 modules under @code{(gnu packages @dots{})} are automatically known to
3196 the command-line tools (@pxref{Package Modules}).
3198 There are a few points worth noting in the above package definition:
3202 The @code{source} field of the package is an @code{<origin>} object
3203 (@pxref{origin Reference}, for the complete reference).
3204 Here, the @code{url-fetch} method from @code{(guix download)} is used,
3205 meaning that the source is a file to be downloaded over FTP or HTTP.
3207 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
3208 the GNU mirrors defined in @code{(guix download)}.
3210 The @code{sha256} field specifies the expected SHA256 hash of the file
3211 being downloaded. It is mandatory, and allows Guix to check the
3212 integrity of the file. The @code{(base32 @dots{})} form introduces the
3213 base32 representation of the hash. You can obtain this information with
3214 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
3215 hash} (@pxref{Invoking guix hash}).
3218 When needed, the @code{origin} form can also have a @code{patches} field
3219 listing patches to be applied, and a @code{snippet} field giving a
3220 Scheme expression to modify the source code.
3223 @cindex GNU Build System
3224 The @code{build-system} field specifies the procedure to build the
3225 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
3226 represents the familiar GNU Build System, where packages may be
3227 configured, built, and installed with the usual @code{./configure &&
3228 make && make check && make install} command sequence.
3231 The @code{arguments} field specifies options for the build system
3232 (@pxref{Build Systems}). Here it is interpreted by
3233 @var{gnu-build-system} as a request run @file{configure} with the
3234 @code{--enable-silent-rules} flag.
3240 What about these quote (@code{'}) characters? They are Scheme syntax to
3241 introduce a literal list; @code{'} is synonymous with @code{quote}.
3242 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
3243 for details. Here the value of the @code{arguments} field is a list of
3244 arguments passed to the build system down the road, as with @code{apply}
3245 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
3248 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
3249 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
3250 @code{#:configure-flags} is a keyword used to pass a keyword argument
3251 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
3255 The @code{inputs} field specifies inputs to the build process---i.e.,
3256 build-time or run-time dependencies of the package. Here, we define an
3257 input called @code{"gawk"} whose value is that of the @var{gawk}
3258 variable; @var{gawk} is itself bound to a @code{<package>} object.
3260 @cindex backquote (quasiquote)
3263 @cindex comma (unquote)
3267 @findex unquote-splicing
3268 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
3269 us to introduce a literal list in the @code{inputs} field, while
3270 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
3271 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
3274 Note that GCC, Coreutils, Bash, and other essential tools do not need to
3275 be specified as inputs here. Instead, @var{gnu-build-system} takes care
3276 of ensuring that they are present (@pxref{Build Systems}).
3278 However, any other dependencies need to be specified in the
3279 @code{inputs} field. Any dependency not specified here will simply be
3280 unavailable to the build process, possibly leading to a build failure.
3283 @xref{package Reference}, for a full description of possible fields.
3285 Once a package definition is in place, the
3286 package may actually be built using the @code{guix build} command-line
3287 tool (@pxref{Invoking guix build}), troubleshooting any build failures
3288 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
3289 package definition using the @command{guix edit} command
3290 (@pxref{Invoking guix edit}).
3291 @xref{Packaging Guidelines}, for
3292 more information on how to test package definitions, and
3293 @ref{Invoking guix lint}, for information on how to check a definition
3294 for style conformance.
3295 @vindex GUIX_PACKAGE_PATH
3296 Lastly, @pxref{Package Modules}, for information
3297 on how to extend the distribution by adding your own package definitions
3298 to @code{GUIX_PACKAGE_PATH}.
3300 Finally, updating the package definition to a new upstream version
3301 can be partly automated by the @command{guix refresh} command
3302 (@pxref{Invoking guix refresh}).
3304 Behind the scenes, a derivation corresponding to the @code{<package>}
3305 object is first computed by the @code{package-derivation} procedure.
3306 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
3307 The build actions it prescribes may then be realized by using the
3308 @code{build-derivations} procedure (@pxref{The Store}).
3310 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
3311 Return the @code{<derivation>} object of @var{package} for @var{system}
3312 (@pxref{Derivations}).
3314 @var{package} must be a valid @code{<package>} object, and @var{system}
3315 must be a string denoting the target system type---e.g.,
3316 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
3317 must be a connection to the daemon, which operates on the store
3318 (@pxref{The Store}).
3322 @cindex cross-compilation
3323 Similarly, it is possible to compute a derivation that cross-builds a
3324 package for some other system:
3326 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
3327 @var{package} @var{target} [@var{system}]
3328 Return the @code{<derivation>} object of @var{package} cross-built from
3329 @var{system} to @var{target}.
3331 @var{target} must be a valid GNU triplet denoting the target hardware
3332 and operating system, such as @code{"mips64el-linux-gnu"}
3333 (@pxref{Configuration Names, GNU configuration triplets,, configure, GNU
3334 Configure and Build System}).
3337 @cindex package transformations
3338 @cindex input rewriting
3339 @cindex dependency tree rewriting
3340 Packages can be manipulated in arbitrary ways. An example of a useful
3341 transformation is @dfn{input rewriting}, whereby the dependency tree of
3342 a package is rewritten by replacing specific inputs by others:
3344 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
3345 [@var{rewrite-name}]
3346 Return a procedure that, when passed a package, replaces its direct and
3347 indirect dependencies (but not its implicit inputs) according to
3348 @var{replacements}. @var{replacements} is a list of package pairs; the
3349 first element of each pair is the package to replace, and the second one
3352 Optionally, @var{rewrite-name} is a one-argument procedure that takes
3353 the name of a package and returns its new name after rewrite.
3357 Consider this example:
3360 (define libressl-instead-of-openssl
3361 ;; This is a procedure to replace OPENSSL by LIBRESSL,
3363 (package-input-rewriting `((,openssl . ,libressl))))
3365 (define git-with-libressl
3366 (libressl-instead-of-openssl git))
3370 Here we first define a rewriting procedure that replaces @var{openssl}
3371 with @var{libressl}. Then we use it to define a @dfn{variant} of the
3372 @var{git} package that uses @var{libressl} instead of @var{openssl}.
3373 This is exactly what the @option{--with-input} command-line option does
3374 (@pxref{Package Transformation Options, @option{--with-input}}).
3376 A more generic procedure to rewrite a package dependency graph is
3377 @code{package-mapping}: it supports arbitrary changes to nodes in the
3380 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
3381 Return a procedure that, given a package, applies @var{proc} to all the packages
3382 depended on and returns the resulting package. The procedure stops recursion
3383 when @var{cut?} returns true for a given package.
3387 * package Reference :: The package data type.
3388 * origin Reference:: The origin data type.
3392 @node package Reference
3393 @subsection @code{package} Reference
3395 This section summarizes all the options available in @code{package}
3396 declarations (@pxref{Defining Packages}).
3398 @deftp {Data Type} package
3399 This is the data type representing a package recipe.
3403 The name of the package, as a string.
3405 @item @code{version}
3406 The version of the package, as a string.
3409 An object telling how the source code for the package should be
3410 acquired. Most of the time, this is an @code{origin} object, which
3411 denotes a file fetched from the Internet (@pxref{origin Reference}). It
3412 can also be any other ``file-like'' object such as a @code{local-file},
3413 which denotes a file from the local file system (@pxref{G-Expressions,
3414 @code{local-file}}).
3416 @item @code{build-system}
3417 The build system that should be used to build the package (@pxref{Build
3420 @item @code{arguments} (default: @code{'()})
3421 The arguments that should be passed to the build system. This is a
3422 list, typically containing sequential keyword-value pairs.
3424 @item @code{inputs} (default: @code{'()})
3425 @itemx @code{native-inputs} (default: @code{'()})
3426 @itemx @code{propagated-inputs} (default: @code{'()})
3427 @cindex inputs, of packages
3428 These fields list dependencies of the package. Each one is a list of
3429 tuples, where each tuple has a label for the input (a string) as its
3430 first element, a package, origin, or derivation as its second element,
3431 and optionally the name of the output thereof that should be used, which
3432 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
3433 more on package outputs). For example, the list below specifies three
3437 `(("libffi" ,libffi)
3438 ("libunistring" ,libunistring)
3439 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
3442 @cindex cross compilation, package dependencies
3443 The distinction between @code{native-inputs} and @code{inputs} is
3444 necessary when considering cross-compilation. When cross-compiling,
3445 dependencies listed in @code{inputs} are built for the @emph{target}
3446 architecture; conversely, dependencies listed in @code{native-inputs}
3447 are built for the architecture of the @emph{build} machine.
3449 @code{native-inputs} is typically used to list tools needed at
3450 build time, but not at run time, such as Autoconf, Automake, pkg-config,
3451 Gettext, or Bison. @command{guix lint} can report likely mistakes in
3452 this area (@pxref{Invoking guix lint}).
3454 @anchor{package-propagated-inputs}
3455 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
3456 specified packages will be automatically installed alongside the package
3457 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
3458 package}}, for information on how @command{guix package} deals with
3461 For example this is necessary when a C/C++ library needs headers of
3462 another library to compile, or when a pkg-config file refers to another
3463 one @i{via} its @code{Requires} field.
3465 Another example where @code{propagated-inputs} is useful is for languages
3466 that lack a facility to record the run-time search path akin to the
3467 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
3468 more. To ensure that libraries written in those languages can find
3469 library code they depend on at run time, run-time dependencies must be
3470 listed in @code{propagated-inputs} rather than @code{inputs}.
3472 @item @code{self-native-input?} (default: @code{#f})
3473 This is a Boolean field telling whether the package should use itself as
3474 a native input when cross-compiling.
3476 @item @code{outputs} (default: @code{'("out")})
3477 The list of output names of the package. @xref{Packages with Multiple
3478 Outputs}, for typical uses of additional outputs.
3480 @item @code{native-search-paths} (default: @code{'()})
3481 @itemx @code{search-paths} (default: @code{'()})
3482 A list of @code{search-path-specification} objects describing
3483 search-path environment variables honored by the package.
3485 @item @code{replacement} (default: @code{#f})
3486 This must be either @code{#f} or a package object that will be used as a
3487 @dfn{replacement} for this package. @xref{Security Updates, grafts},
3490 @item @code{synopsis}
3491 A one-line description of the package.
3493 @item @code{description}
3494 A more elaborate description of the package.
3496 @item @code{license}
3497 @cindex license, of packages
3498 The license of the package; a value from @code{(guix licenses)},
3499 or a list of such values.
3501 @item @code{home-page}
3502 The URL to the home-page of the package, as a string.
3504 @item @code{supported-systems} (default: @var{%supported-systems})
3505 The list of systems supported by the package, as strings of the form
3506 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
3508 @item @code{maintainers} (default: @code{'()})
3509 The list of maintainers of the package, as @code{maintainer} objects.
3511 @item @code{location} (default: source location of the @code{package} form)
3512 The source location of the package. It is useful to override this when
3513 inheriting from another package, in which case this field is not
3514 automatically corrected.
3519 @node origin Reference
3520 @subsection @code{origin} Reference
3522 This section summarizes all the options available in @code{origin}
3523 declarations (@pxref{Defining Packages}).
3525 @deftp {Data Type} origin
3526 This is the data type representing a source code origin.
3530 An object containing the URI of the source. The object type depends on
3531 the @code{method} (see below). For example, when using the
3532 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
3533 values are: a URL represented as a string, or a list thereof.
3536 A procedure that handles the URI.
3541 @item @var{url-fetch} from @code{(guix download)}
3542 download a file from the HTTP, HTTPS, or FTP URL specified in the
3546 @item @var{git-fetch} from @code{(guix git-download)}
3547 clone the Git version control repository, and check out the revision
3548 specified in the @code{uri} field as a @code{git-reference} object; a
3549 @code{git-reference} looks like this:
3553 (url "git://git.debian.org/git/pkg-shadow/shadow")
3554 (commit "v4.1.5.1"))
3559 A bytevector containing the SHA-256 hash of the source. Typically the
3560 @code{base32} form is used here to generate the bytevector from a
3563 You can obtain this information using @code{guix download}
3564 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
3567 @item @code{file-name} (default: @code{#f})
3568 The file name under which the source code should be saved. When this is
3569 @code{#f}, a sensible default value will be used in most cases. In case
3570 the source is fetched from a URL, the file name from the URL will be
3571 used. For version control checkouts, it is recommended to provide the
3572 file name explicitly because the default is not very descriptive.
3574 @item @code{patches} (default: @code{'()})
3575 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
3576 file-like objects}) pointing to patches to be applied to the source.
3578 This list of patches must be unconditional. In particular, it cannot
3579 depend on the value of @code{%current-system} or
3580 @code{%current-target-system}.
3582 @item @code{snippet} (default: @code{#f})
3583 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
3584 in the source directory. This is a convenient way to modify the source,
3585 sometimes more convenient than a patch.
3587 @item @code{patch-flags} (default: @code{'("-p1")})
3588 A list of command-line flags that should be passed to the @code{patch}
3591 @item @code{patch-inputs} (default: @code{#f})
3592 Input packages or derivations to the patching process. When this is
3593 @code{#f}, the usual set of inputs necessary for patching are provided,
3594 such as GNU@tie{}Patch.
3596 @item @code{modules} (default: @code{'()})
3597 A list of Guile modules that should be loaded during the patching
3598 process and while running the code in the @code{snippet} field.
3600 @item @code{patch-guile} (default: @code{#f})
3601 The Guile package that should be used in the patching process. When
3602 this is @code{#f}, a sensible default is used.
3608 @section Build Systems
3610 @cindex build system
3611 Each package definition specifies a @dfn{build system} and arguments for
3612 that build system (@pxref{Defining Packages}). This @code{build-system}
3613 field represents the build procedure of the package, as well as implicit
3614 dependencies of that build procedure.
3616 Build systems are @code{<build-system>} objects. The interface to
3617 create and manipulate them is provided by the @code{(guix build-system)}
3618 module, and actual build systems are exported by specific modules.
3620 @cindex bag (low-level package representation)
3621 Under the hood, build systems first compile package objects to
3622 @dfn{bags}. A @dfn{bag} is like a package, but with less
3623 ornamentation---in other words, a bag is a lower-level representation of
3624 a package, which includes all the inputs of that package, including some
3625 that were implicitly added by the build system. This intermediate
3626 representation is then compiled to a derivation (@pxref{Derivations}).
3628 Build systems accept an optional list of @dfn{arguments}. In package
3629 definitions, these are passed @i{via} the @code{arguments} field
3630 (@pxref{Defining Packages}). They are typically keyword arguments
3631 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
3632 Guile Reference Manual}). The value of these arguments is usually
3633 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
3634 by the daemon (@pxref{Derivations}).
3636 The main build system is @var{gnu-build-system}, which implements the
3637 standard build procedure for GNU and many other packages. It
3638 is provided by the @code{(guix build-system gnu)} module.
3640 @defvr {Scheme Variable} gnu-build-system
3641 @var{gnu-build-system} represents the GNU Build System, and variants
3642 thereof (@pxref{Configuration, configuration and makefile conventions,,
3643 standards, GNU Coding Standards}).
3645 @cindex build phases
3646 In a nutshell, packages using it are configured, built, and installed with
3647 the usual @code{./configure && make && make check && make install}
3648 command sequence. In practice, a few additional steps are often needed.
3649 All these steps are split up in separate @dfn{phases},
3650 notably@footnote{Please see the @code{(guix build gnu-build-system)}
3651 modules for more details about the build phases.}:
3655 Unpack the source tarball, and change the current directory to the
3656 extracted source tree. If the source is actually a directory, copy it
3657 to the build tree, and enter that directory.
3659 @item patch-source-shebangs
3660 Patch shebangs encountered in source files so they refer to the right
3661 store file names. For instance, this changes @code{#!/bin/sh} to
3662 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
3665 Run the @file{configure} script with a number of default options, such
3666 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
3667 by the @code{#:configure-flags} argument.
3670 Run @code{make} with the list of flags specified with
3671 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
3672 (the default), build with @code{make -j}.
3675 Run @code{make check}, or some other target specified with
3676 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
3677 @code{#:parallel-tests?} argument is true (the default), run @code{make
3681 Run @code{make install} with the flags listed in @code{#:make-flags}.
3683 @item patch-shebangs
3684 Patch shebangs on the installed executable files.
3687 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
3688 is false), copying them to the @code{debug} output when available
3689 (@pxref{Installing Debugging Files}).
3692 @vindex %standard-phases
3693 The build-side module @code{(guix build gnu-build-system)} defines
3694 @var{%standard-phases} as the default list of build phases.
3695 @var{%standard-phases} is a list of symbol/procedure pairs, where the
3696 procedure implements the actual phase.
3698 The list of phases used for a particular package can be changed with the
3699 @code{#:phases} parameter. For instance, passing:
3702 #:phases (modify-phases %standard-phases (delete 'configure))
3705 means that all the phases described above will be used, except the
3706 @code{configure} phase.
3708 In addition, this build system ensures that the ``standard'' environment
3709 for GNU packages is available. This includes tools such as GCC, libc,
3710 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
3711 build-system gnu)} module for a complete list). We call these the
3712 @dfn{implicit inputs} of a package, because package definitions do not
3713 have to mention them.
3716 Other @code{<build-system>} objects are defined to support other
3717 conventions and tools used by free software packages. They inherit most
3718 of @var{gnu-build-system}, and differ mainly in the set of inputs
3719 implicitly added to the build process, and in the list of phases
3720 executed. Some of these build systems are listed below.
3722 @defvr {Scheme Variable} ant-build-system
3723 This variable is exported by @code{(guix build-system ant)}. It
3724 implements the build procedure for Java packages that can be built with
3725 @url{http://ant.apache.org/, Ant build tool}.
3727 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
3728 provided by the @code{icedtea} package to the set of inputs. Different
3729 packages can be specified with the @code{#:ant} and @code{#:jdk}
3730 parameters, respectively.
3732 When the original package does not provide a suitable Ant build file,
3733 the parameter @code{#:jar-name} can be used to generate a minimal Ant
3734 build file @file{build.xml} with tasks to build the specified jar
3735 archive. In this case the parameter @code{#:source-dir} can be used to
3736 specify the source sub-directory, defaulting to ``src''.
3738 The @code{#:main-class} parameter can be used with the minimal ant
3739 buildfile to specify the main class of the resulting jar. This makes the
3740 jar file executable. The @code{#:test-include} parameter can be used to
3741 specify the list of junit tests to run. It defaults to
3742 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
3743 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
3744 because abstract classes cannot be run as tests.
3746 The parameter @code{#:build-target} can be used to specify the Ant task
3747 that should be run during the @code{build} phase. By default the
3748 ``jar'' task will be run.
3752 @defvr {Scheme Variable} asdf-build-system/source
3753 @defvrx {Scheme Variable} asdf-build-system/sbcl
3754 @defvrx {Scheme Variable} asdf-build-system/ecl
3756 These variables, exported by @code{(guix build-system asdf)}, implement
3757 build procedures for Common Lisp packages using
3758 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
3759 definition facility for Common Lisp programs and libraries.
3761 The @code{asdf-build-system/source} system installs the packages in
3762 source form, and can be loaded using any common lisp implementation, via
3763 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
3764 systems in the format which a particular implementation understands.
3765 These build systems can also be used to produce executable programs, or
3766 lisp images which contain a set of packages pre-loaded.
3768 The build system uses naming conventions. For binary packages, the
3769 package name should be prefixed with the lisp implementation, such as
3770 @code{sbcl-} for @code{asdf-build-system/sbcl}.
3772 Additionally, the corresponding source package should be labeled using
3773 the same convention as python packages (see @ref{Python Modules}), using
3774 the @code{cl-} prefix.
3776 For binary packages, each system should be defined as a Guix package.
3777 If one package @code{origin} contains several systems, package variants
3778 can be created in order to build all the systems. Source packages,
3779 which use @code{asdf-build-system/source}, may contain several systems.
3781 In order to create executable programs and images, the build-side
3782 procedures @code{build-program} and @code{build-image} can be used.
3783 They should be called in a build phase after the @code{create-symlinks}
3784 phase, so that the system which was just built can be used within the
3785 resulting image. @code{build-program} requires a list of Common Lisp
3786 expressions to be passed as the @code{#:entry-program} argument.
3788 If the system is not defined within its own @code{.asd} file of the same
3789 name, then the @code{#:asd-file} parameter should be used to specify
3790 which file the system is defined in. Furthermore, if the package
3791 defines a system for its tests in a separate file, it will be loaded
3792 before the tests are run if it is specified by the
3793 @code{#:test-asd-file} parameter. If it is not set, the files
3794 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
3795 and @code{test.asd} will be tried if they exist.
3797 If for some reason the package must be named in a different way than the
3798 naming conventions suggest, the @code{#:asd-system-name} parameter can
3799 be used to specify the name of the system.
3803 @defvr {Scheme Variable} cargo-build-system
3804 @cindex Rust programming language
3805 @cindex Cargo (Rust build system)
3806 This variable is exported by @code{(guix build-system cargo)}. It
3807 supports builds of packages using Cargo, the build tool of the
3808 @uref{https://www.rust-lang.org, Rust programming language}.
3810 In its @code{configure} phase, this build system replaces dependencies
3811 specified in the @file{Carto.toml} file with inputs to the Guix package.
3812 The @code{install} phase installs the binaries, and it also installs the
3813 source code and @file{Cargo.toml} file.
3816 @defvr {Scheme Variable} cmake-build-system
3817 This variable is exported by @code{(guix build-system cmake)}. It
3818 implements the build procedure for packages using the
3819 @url{http://www.cmake.org, CMake build tool}.
3821 It automatically adds the @code{cmake} package to the set of inputs.
3822 Which package is used can be specified with the @code{#:cmake}
3825 The @code{#:configure-flags} parameter is taken as a list of flags
3826 passed to the @command{cmake} command. The @code{#:build-type}
3827 parameter specifies in abstract terms the flags passed to the compiler;
3828 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
3829 debugging information''), which roughly means that code is compiled with
3830 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
3833 @defvr {Scheme Variable} go-build-system
3834 This variable is exported by @code{(guix build-system go)}. It
3835 implements a build procedure for Go packages using the standard
3836 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
3837 Go build mechanisms}.
3839 The user is expected to provide a value for the key @code{#:import-path}
3840 and, in some cases, @code{#:unpack-path}. The
3841 @url{https://golang.org/doc/code.html#ImportPaths, import path}
3842 corresponds to the file system path expected by the package's build
3843 scripts and any referring packages, and provides a unique way to
3844 refer to a Go package. It is typically based on a combination of the
3845 package source code's remote URI and file system hierarchy structure. In
3846 some cases, you will need to unpack the package's source code to a
3847 different directory structure than the one indicated by the import path,
3848 and @code{#:unpack-path} should be used in such cases.
3850 Packages that provide Go libraries should be installed along with their
3851 source code. The key @code{#:install-source?}, which defaults to
3852 @code{#t}, controls whether or not the source code is installed. It can
3853 be set to @code{#f} for packages that only provide executable files.
3856 @defvr {Scheme Variable} glib-or-gtk-build-system
3857 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
3858 is intended for use with packages making use of GLib or GTK+.
3860 This build system adds the following two phases to the ones defined by
3861 @var{gnu-build-system}:
3864 @item glib-or-gtk-wrap
3865 The phase @code{glib-or-gtk-wrap} ensures that programs in
3866 @file{bin/} are able to find GLib ``schemas'' and
3867 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
3868 modules}. This is achieved by wrapping the programs in launch scripts
3869 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
3870 environment variables.
3872 It is possible to exclude specific package outputs from that wrapping
3873 process by listing their names in the
3874 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
3875 when an output is known not to contain any GLib or GTK+ binaries, and
3876 where wrapping would gratuitously add a dependency of that output on
3879 @item glib-or-gtk-compile-schemas
3880 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
3881 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
3882 GSettings schemas} of GLib are compiled. Compilation is performed by the
3883 @command{glib-compile-schemas} program. It is provided by the package
3884 @code{glib:bin} which is automatically imported by the build system.
3885 The @code{glib} package providing @command{glib-compile-schemas} can be
3886 specified with the @code{#:glib} parameter.
3889 Both phases are executed after the @code{install} phase.
3892 @defvr {Scheme Variable} minify-build-system
3893 This variable is exported by @code{(guix build-system minify)}. It
3894 implements a minification procedure for simple JavaScript packages.
3896 It adds @code{uglify-js} to the set of inputs and uses it to compress
3897 all JavaScript files in the @file{src} directory. A different minifier
3898 package can be specified with the @code{#:uglify-js} parameter, but it
3899 is expected that the package writes the minified code to the standard
3902 When the input JavaScript files are not all located in the @file{src}
3903 directory, the parameter @code{#:javascript-files} can be used to
3904 specify a list of file names to feed to the minifier.
3907 @defvr {Scheme Variable} ocaml-build-system
3908 This variable is exported by @code{(guix build-system ocaml)}. It implements
3909 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
3910 of choosing the correct set of commands to run for each package. OCaml
3911 packages can expect many different commands to be run. This build system will
3914 When the package has a @file{setup.ml} file present at the top-level, it will
3915 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
3916 @code{ocaml setup.ml -install}. The build system will assume that this file
3917 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
3918 care of setting the prefix and enabling tests if they are not disabled. You
3919 can pass configure and build flags with the @code{#:configure-flags} and
3920 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
3921 set of flags used to enable tests. The @code{#:use-make?} key can be used to
3922 bypass this system in the build and install phases.
3924 When the package has a @file{configure} file, it is assumed that it is a
3925 hand-made configure script that requires a different argument format than
3926 in the @code{gnu-build-system}. You can add more flags with the
3927 @code{#:configure-flags} key.
3929 When the package has a @file{Makefile} file (or @code{#:use-make?} is
3930 @code{#t}), it will be used and more flags can be passed to the build and
3931 install phases with the @code{#:make-flags} key.
3933 Finally, some packages do not have these files and use a somewhat standard
3934 location for its build system. In that case, the build system will run
3935 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
3936 providing the path to the required findlib module. Additional flags can
3937 be passed via the @code{#:build-flags} key. Install is taken care of by
3938 @command{opam-installer}. In this case, the @code{opam} package must
3939 be added to the @code{native-inputs} field of the package definition.
3941 Note that most OCaml packages assume they will be installed in the same
3942 directory as OCaml, which is not what we want in guix. In particular, they
3943 will install @file{.so} files in their module's directory, which is usually
3944 fine because it is in the OCaml compiler directory. In guix though, these
3945 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
3946 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
3947 @file{.so} libraries should be installed.
3950 @defvr {Scheme Variable} python-build-system
3951 This variable is exported by @code{(guix build-system python)}. It
3952 implements the more or less standard build procedure used by Python
3953 packages, which consists in running @code{python setup.py build} and
3954 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
3956 For packages that install stand-alone Python programs under @code{bin/},
3957 it takes care of wrapping these programs so that their @code{PYTHONPATH}
3958 environment variable points to all the Python libraries they depend on.
3960 Which Python package is used to perform the build can be specified with
3961 the @code{#:python} parameter. This is a useful way to force a package
3962 to be built for a specific version of the Python interpreter, which
3963 might be necessary if the package is only compatible with a single
3964 interpreter version.
3966 By default guix calls @code{setup.py} under control of
3967 @code{setuptools}, much like @command{pip} does. Some packages are not
3968 compatible with setuptools (and pip), thus you can disable this by
3969 setting the @code{#:use-setuptools} parameter to @code{#f}.
3972 @defvr {Scheme Variable} perl-build-system
3973 This variable is exported by @code{(guix build-system perl)}. It
3974 implements the standard build procedure for Perl packages, which either
3975 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
3976 followed by @code{Build} and @code{Build install}; or in running
3977 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
3978 @code{make} and @code{make install}, depending on which of
3979 @code{Build.PL} or @code{Makefile.PL} is present in the package
3980 distribution. Preference is given to the former if both @code{Build.PL}
3981 and @code{Makefile.PL} exist in the package distribution. This
3982 preference can be reversed by specifying @code{#t} for the
3983 @code{#:make-maker?} parameter.
3985 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
3986 passes flags specified by the @code{#:make-maker-flags} or
3987 @code{#:module-build-flags} parameter, respectively.
3989 Which Perl package is used can be specified with @code{#:perl}.
3992 @defvr {Scheme Variable} r-build-system
3993 This variable is exported by @code{(guix build-system r)}. It
3994 implements the build procedure used by @uref{http://r-project.org, R}
3995 packages, which essentially is little more than running @code{R CMD
3996 INSTALL --library=/gnu/store/@dots{}} in an environment where
3997 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
3998 are run after installation using the R function
3999 @code{tools::testInstalledPackage}.
4002 @defvr {Scheme Variable} texlive-build-system
4003 This variable is exported by @code{(guix build-system texlive)}. It is
4004 used to build TeX packages in batch mode with a specified engine. The
4005 build system sets the @code{TEXINPUTS} variable to find all TeX source
4006 files in the inputs.
4008 By default it runs @code{luatex} on all files ending on @code{ins}. A
4009 different engine and format can be specified with the
4010 @code{#:tex-format} argument. Different build targets can be specified
4011 with the @code{#:build-targets} argument, which expects a list of file
4012 names. The build system adds only @code{texlive-bin} and
4013 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
4014 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
4015 and @code{#:texlive-latex-base}, respectively.
4017 The @code{#:tex-directory} parameter tells the build system where to
4018 install the built files under the texmf tree.
4021 @defvr {Scheme Variable} ruby-build-system
4022 This variable is exported by @code{(guix build-system ruby)}. It
4023 implements the RubyGems build procedure used by Ruby packages, which
4024 involves running @code{gem build} followed by @code{gem install}.
4026 The @code{source} field of a package that uses this build system
4027 typically references a gem archive, since this is the format that Ruby
4028 developers use when releasing their software. The build system unpacks
4029 the gem archive, potentially patches the source, runs the test suite,
4030 repackages the gem, and installs it. Additionally, directories and
4031 tarballs may be referenced to allow building unreleased gems from Git or
4032 a traditional source release tarball.
4034 Which Ruby package is used can be specified with the @code{#:ruby}
4035 parameter. A list of additional flags to be passed to the @command{gem}
4036 command can be specified with the @code{#:gem-flags} parameter.
4039 @defvr {Scheme Variable} waf-build-system
4040 This variable is exported by @code{(guix build-system waf)}. It
4041 implements a build procedure around the @code{waf} script. The common
4042 phases---@code{configure}, @code{build}, and @code{install}---are
4043 implemented by passing their names as arguments to the @code{waf}
4046 The @code{waf} script is executed by the Python interpreter. Which
4047 Python package is used to run the script can be specified with the
4048 @code{#:python} parameter.
4051 @defvr {Scheme Variable} scons-build-system
4052 This variable is exported by @code{(guix build-system scons)}. It
4053 implements the build procedure used by the SCons software construction
4054 tool. This build system runs @code{scons} to build the package,
4055 @code{scons test} to run tests, and then @code{scons install} to install
4058 Additional flags to be passed to @code{scons} can be specified with the
4059 @code{#:scons-flags} parameter. The version of Python used to run SCons
4060 can be specified by selecting the appropriate SCons package with the
4061 @code{#:scons} parameter.
4064 @defvr {Scheme Variable} haskell-build-system
4065 This variable is exported by @code{(guix build-system haskell)}. It
4066 implements the Cabal build procedure used by Haskell packages, which
4067 involves running @code{runhaskell Setup.hs configure
4068 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
4069 Instead of installing the package by running @code{runhaskell Setup.hs
4070 install}, to avoid trying to register libraries in the read-only
4071 compiler store directory, the build system uses @code{runhaskell
4072 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
4073 addition, the build system generates the package documentation by
4074 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
4075 is passed. Optional Haddock parameters can be passed with the help of
4076 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
4077 not found, the build system looks for @code{Setup.lhs} instead.
4079 Which Haskell compiler is used can be specified with the @code{#:haskell}
4080 parameter which defaults to @code{ghc}.
4083 @defvr {Scheme Variable} dub-build-system
4084 This variable is exported by @code{(guix build-system dub)}. It
4085 implements the Dub build procedure used by D packages, which
4086 involves running @code{dub build} and @code{dub run}.
4087 Installation is done by copying the files manually.
4089 Which D compiler is used can be specified with the @code{#:ldc}
4090 parameter which defaults to @code{ldc}.
4093 @defvr {Scheme Variable} emacs-build-system
4094 This variable is exported by @code{(guix build-system emacs)}. It
4095 implements an installation procedure similar to the packaging system
4096 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
4098 It first creates the @code{@var{package}-autoloads.el} file, then it
4099 byte compiles all Emacs Lisp files. Differently from the Emacs
4100 packaging system, the Info documentation files are moved to the standard
4101 documentation directory and the @file{dir} file is deleted. Each
4102 package is installed in its own directory under
4103 @file{share/emacs/site-lisp/guix.d}.
4106 @defvr {Scheme Variable} font-build-system
4107 This variable is exported by @code{(guix build-system font)}. It
4108 implements an installation procedure for font packages where upstream
4109 provides pre-compiled TrueType, OpenType, etc. font files that merely
4110 need to be copied into place. It copies font files to standard
4111 locations in the output directory.
4114 @defvr {Scheme Variable} meson-build-system
4115 This variable is exported by @code{(guix build-system meson)}. It
4116 implements the build procedure for packages that use
4117 @url{http://mesonbuild.com, Meson} as their build system.
4119 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
4120 of inputs, and they can be changed with the parameters @code{#:meson}
4121 and @code{#:ninja} if needed. The default Meson is
4122 @code{meson-for-build}, which is special because it doesn't clear the
4123 @code{RUNPATH} of binaries and libraries when they are installed.
4125 This build system is an extension of @var{gnu-build-system}, but with the
4126 following phases changed to some specific for Meson:
4131 The phase runs @code{meson} with the flags specified in
4132 @code{#:configure-flags}. The flag @code{--build-type} is always set to
4133 @code{plain} unless something else is specified in @code{#:build-type}.
4136 The phase runs @code{ninja} to build the package in parallel by default, but
4137 this can be changed with @code{#:parallel-build?}.
4140 The phase runs @code{ninja} with the target specified in @code{#:test-target},
4141 which is @code{"test"} by default.
4144 The phase runs @code{ninja install} and can not be changed.
4147 Apart from that, the build system also adds the following phases:
4152 This phase ensures that all binaries can find the libraries they need.
4153 It searches for required libraries in subdirectories of the package being
4154 built, and adds those to @code{RUNPATH} where needed. It also removes
4155 references to libraries left over from the build phase by
4156 @code{meson-for-build}, such as test dependencies, that aren't actually
4157 required for the program to run.
4159 @item glib-or-gtk-wrap
4160 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
4161 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
4163 @item glib-or-gtk-compile-schemas
4164 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
4165 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
4169 Lastly, for packages that do not need anything as sophisticated, a
4170 ``trivial'' build system is provided. It is trivial in the sense that
4171 it provides basically no support: it does not pull any implicit inputs,
4172 and does not have a notion of build phases.
4174 @defvr {Scheme Variable} trivial-build-system
4175 This variable is exported by @code{(guix build-system trivial)}.
4177 This build system requires a @code{#:builder} argument. This argument
4178 must be a Scheme expression that builds the package output(s)---as
4179 with @code{build-expression->derivation} (@pxref{Derivations,
4180 @code{build-expression->derivation}}).
4190 Conceptually, the @dfn{store} is the place where derivations that have
4191 been built successfully are stored---by default, @file{/gnu/store}.
4192 Sub-directories in the store are referred to as @dfn{store items} or
4193 sometimes @dfn{store paths}. The store has an associated database that
4194 contains information such as the store paths referred to by each store
4195 path, and the list of @emph{valid} store items---results of successful
4196 builds. This database resides in @file{@var{localstatedir}/guix/db},
4197 where @var{localstatedir} is the state directory specified @i{via}
4198 @option{--localstatedir} at configure time, usually @file{/var}.
4200 The store is @emph{always} accessed by the daemon on behalf of its clients
4201 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
4202 connect to the daemon over a Unix-domain socket, send requests to it,
4203 and read the result---these are remote procedure calls, or RPCs.
4206 Users must @emph{never} modify files under @file{/gnu/store} directly.
4207 This would lead to inconsistencies and break the immutability
4208 assumptions of Guix's functional model (@pxref{Introduction}).
4210 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
4211 how to check the integrity of the store and attempt recovery from
4212 accidental modifications.
4215 The @code{(guix store)} module provides procedures to connect to the
4216 daemon, and to perform RPCs. These are described below. By default,
4217 @code{open-connection}, and thus all the @command{guix} commands,
4218 connect to the local daemon or to the URI specified by the
4219 @code{GUIX_DAEMON_SOCKET} environment variable.
4221 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
4222 When set, the value of this variable should be a file name or a URI
4223 designating the daemon endpoint. When it is a file name, it denotes a
4224 Unix-domain socket to connect to. In addition to file names, the
4225 supported URI schemes are:
4230 These are for Unix-domain sockets.
4231 @code{file:///var/guix/daemon-socket/socket} is equivalent to
4232 @file{/var/guix/daemon-socket/socket}.
4235 @cindex daemon, remote access
4236 @cindex remote access to the daemon
4237 @cindex daemon, cluster setup
4238 @cindex clusters, daemon setup
4239 These URIs denote connections over TCP/IP, without encryption nor
4240 authentication of the remote host. The URI must specify the host name
4241 and optionally a port number (by default port 44146 is used):
4244 guix://master.guix.example.org:1234
4247 This setup is suitable on local networks, such as clusters, where only
4248 trusted nodes may connect to the build daemon at
4249 @code{master.guix.example.org}.
4251 The @code{--listen} option of @command{guix-daemon} can be used to
4252 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
4256 @cindex SSH access to build daemons
4257 These URIs allow you to connect to a remote daemon over
4258 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
4259 A typical URL might look like this:
4262 ssh://charlie@@guix.example.org:22
4265 As for @command{guix copy}, the usual OpenSSH client configuration files
4266 are honored (@pxref{Invoking guix copy}).
4269 Additional URI schemes may be supported in the future.
4271 @c XXX: Remove this note when the protocol incurs fewer round trips
4272 @c and when (guix derivations) no longer relies on file system access.
4274 The ability to connect to remote build daemons is considered
4275 experimental as of @value{VERSION}. Please get in touch with us to
4276 share any problems or suggestions you may have (@pxref{Contributing}).
4280 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
4281 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
4282 @var{reserve-space?} is true, instruct it to reserve a little bit of
4283 extra space on the file system so that the garbage collector can still
4284 operate should the disk become full. Return a server object.
4286 @var{file} defaults to @var{%default-socket-path}, which is the normal
4287 location given the options that were passed to @command{configure}.
4290 @deffn {Scheme Procedure} close-connection @var{server}
4291 Close the connection to @var{server}.
4294 @defvr {Scheme Variable} current-build-output-port
4295 This variable is bound to a SRFI-39 parameter, which refers to the port
4296 where build and error logs sent by the daemon should be written.
4299 Procedures that make RPCs all take a server object as their first
4302 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
4303 @cindex invalid store items
4304 Return @code{#t} when @var{path} designates a valid store item and
4305 @code{#f} otherwise (an invalid item may exist on disk but still be
4306 invalid, for instance because it is the result of an aborted or failed
4309 A @code{&nix-protocol-error} condition is raised if @var{path} is not
4310 prefixed by the store directory (@file{/gnu/store}).
4313 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
4314 Add @var{text} under file @var{name} in the store, and return its store
4315 path. @var{references} is the list of store paths referred to by the
4316 resulting store path.
4319 @deffn {Scheme Procedure} build-derivations @var{server} @var{derivations}
4320 Build @var{derivations} (a list of @code{<derivation>} objects or
4321 derivation paths), and return when the worker is done building them.
4322 Return @code{#t} on success.
4325 Note that the @code{(guix monads)} module provides a monad as well as
4326 monadic versions of the above procedures, with the goal of making it
4327 more convenient to work with code that accesses the store (@pxref{The
4331 @i{This section is currently incomplete.}
4334 @section Derivations
4337 Low-level build actions and the environment in which they are performed
4338 are represented by @dfn{derivations}. A derivation contains the
4339 following pieces of information:
4343 The outputs of the derivation---derivations produce at least one file or
4344 directory in the store, but may produce more.
4347 The inputs of the derivations, which may be other derivations or plain
4348 files in the store (patches, build scripts, etc.)
4351 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
4354 The file name of a build script in the store, along with the arguments
4358 A list of environment variables to be defined.
4362 @cindex derivation path
4363 Derivations allow clients of the daemon to communicate build actions to
4364 the store. They exist in two forms: as an in-memory representation,
4365 both on the client- and daemon-side, and as files in the store whose
4366 name end in @code{.drv}---these files are referred to as @dfn{derivation
4367 paths}. Derivations paths can be passed to the @code{build-derivations}
4368 procedure to perform the build actions they prescribe (@pxref{The
4371 @cindex fixed-output derivations
4372 Operations such as file downloads and version-control checkouts for
4373 which the expected content hash is known in advance are modeled as
4374 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
4375 of a fixed-output derivation are independent of its inputs---e.g., a
4376 source code download produces the same result regardless of the download
4377 method and tools being used.
4379 The @code{(guix derivations)} module provides a representation of
4380 derivations as Scheme objects, along with procedures to create and
4381 otherwise manipulate derivations. The lowest-level primitive to create
4382 a derivation is the @code{derivation} procedure:
4384 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
4385 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
4386 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
4387 [#:system (%current-system)] [#:references-graphs #f] @
4388 [#:allowed-references #f] [#:disallowed-references #f] @
4389 [#:leaked-env-vars #f] [#:local-build? #f] @
4390 [#:substitutable? #t]
4391 Build a derivation with the given arguments, and return the resulting
4392 @code{<derivation>} object.
4394 When @var{hash} and @var{hash-algo} are given, a
4395 @dfn{fixed-output derivation} is created---i.e., one whose result is
4396 known in advance, such as a file download. If, in addition,
4397 @var{recursive?} is true, then that fixed output may be an executable
4398 file or a directory and @var{hash} must be the hash of an archive
4399 containing this output.
4401 When @var{references-graphs} is true, it must be a list of file
4402 name/store path pairs. In that case, the reference graph of each store
4403 path is exported in the build environment in the corresponding file, in
4404 a simple text format.
4406 When @var{allowed-references} is true, it must be a list of store items
4407 or outputs that the derivation's output may refer to. Likewise,
4408 @var{disallowed-references}, if true, must be a list of things the
4409 outputs may @emph{not} refer to.
4411 When @var{leaked-env-vars} is true, it must be a list of strings
4412 denoting environment variables that are allowed to ``leak'' from the
4413 daemon's environment to the build environment. This is only applicable
4414 to fixed-output derivations---i.e., when @var{hash} is true. The main
4415 use is to allow variables such as @code{http_proxy} to be passed to
4416 derivations that download files.
4418 When @var{local-build?} is true, declare that the derivation is not a
4419 good candidate for offloading and should rather be built locally
4420 (@pxref{Daemon Offload Setup}). This is the case for small derivations
4421 where the costs of data transfers would outweigh the benefits.
4423 When @var{substitutable?} is false, declare that substitutes of the
4424 derivation's output should not be used (@pxref{Substitutes}). This is
4425 useful, for instance, when building packages that capture details of the
4426 host CPU instruction set.
4430 Here's an example with a shell script as its builder, assuming
4431 @var{store} is an open connection to the daemon, and @var{bash} points
4432 to a Bash executable in the store:
4435 (use-modules (guix utils)
4439 (let ((builder ; add the Bash script to the store
4440 (add-text-to-store store "my-builder.sh"
4441 "echo hello world > $out\n" '())))
4442 (derivation store "foo"
4443 bash `("-e" ,builder)
4444 #:inputs `((,bash) (,builder))
4445 #:env-vars '(("HOME" . "/homeless"))))
4446 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
4449 As can be guessed, this primitive is cumbersome to use directly. A
4450 better approach is to write build scripts in Scheme, of course! The
4451 best course of action for that is to write the build code as a
4452 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
4453 information, @pxref{G-Expressions}.
4455 Once upon a time, @code{gexp->derivation} did not exist and constructing
4456 derivations with build code written in Scheme was achieved with
4457 @code{build-expression->derivation}, documented below. This procedure
4458 is now deprecated in favor of the much nicer @code{gexp->derivation}.
4460 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
4461 @var{name} @var{exp} @
4462 [#:system (%current-system)] [#:inputs '()] @
4463 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
4464 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
4465 [#:references-graphs #f] [#:allowed-references #f] @
4466 [#:disallowed-references #f] @
4467 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
4468 Return a derivation that executes Scheme expression @var{exp} as a
4469 builder for derivation @var{name}. @var{inputs} must be a list of
4470 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
4471 @code{"out"} is assumed. @var{modules} is a list of names of Guile
4472 modules from the current search path to be copied in the store,
4473 compiled, and made available in the load path during the execution of
4474 @var{exp}---e.g., @code{((guix build utils) (guix build
4475 gnu-build-system))}.
4477 @var{exp} is evaluated in an environment where @code{%outputs} is bound
4478 to a list of output/path pairs, and where @code{%build-inputs} is bound
4479 to a list of string/output-path pairs made from @var{inputs}.
4480 Optionally, @var{env-vars} is a list of string pairs specifying the name
4481 and value of environment variables visible to the builder. The builder
4482 terminates by passing the result of @var{exp} to @code{exit}; thus, when
4483 @var{exp} returns @code{#f}, the build is considered to have failed.
4485 @var{exp} is built using @var{guile-for-build} (a derivation). When
4486 @var{guile-for-build} is omitted or is @code{#f}, the value of the
4487 @code{%guile-for-build} fluid is used instead.
4489 See the @code{derivation} procedure for the meaning of
4490 @var{references-graphs}, @var{allowed-references},
4491 @var{disallowed-references}, @var{local-build?}, and
4492 @var{substitutable?}.
4496 Here's an example of a single-output derivation that creates a directory
4497 containing one file:
4500 (let ((builder '(let ((out (assoc-ref %outputs "out")))
4501 (mkdir out) ; create /gnu/store/@dots{}-goo
4502 (call-with-output-file (string-append out "/test")
4504 (display '(hello guix) p))))))
4505 (build-expression->derivation store "goo" builder))
4507 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
4511 @node The Store Monad
4512 @section The Store Monad
4516 The procedures that operate on the store described in the previous
4517 sections all take an open connection to the build daemon as their first
4518 argument. Although the underlying model is functional, they either have
4519 side effects or depend on the current state of the store.
4521 The former is inconvenient: the connection to the build daemon has to be
4522 carried around in all those functions, making it impossible to compose
4523 functions that do not take that parameter with functions that do. The
4524 latter can be problematic: since store operations have side effects
4525 and/or depend on external state, they have to be properly sequenced.
4527 @cindex monadic values
4528 @cindex monadic functions
4529 This is where the @code{(guix monads)} module comes in. This module
4530 provides a framework for working with @dfn{monads}, and a particularly
4531 useful monad for our uses, the @dfn{store monad}. Monads are a
4532 construct that allows two things: associating ``context'' with values
4533 (in our case, the context is the store), and building sequences of
4534 computations (here computations include accesses to the store). Values
4535 in a monad---values that carry this additional context---are called
4536 @dfn{monadic values}; procedures that return such values are called
4537 @dfn{monadic procedures}.
4539 Consider this ``normal'' procedure:
4542 (define (sh-symlink store)
4543 ;; Return a derivation that symlinks the 'bash' executable.
4544 (let* ((drv (package-derivation store bash))
4545 (out (derivation->output-path drv))
4546 (sh (string-append out "/bin/bash")))
4547 (build-expression->derivation store "sh"
4548 `(symlink ,sh %output))))
4551 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
4552 as a monadic function:
4555 (define (sh-symlink)
4556 ;; Same, but return a monadic value.
4557 (mlet %store-monad ((drv (package->derivation bash)))
4558 (gexp->derivation "sh"
4559 #~(symlink (string-append #$drv "/bin/bash")
4563 There are several things to note in the second version: the @code{store}
4564 parameter is now implicit and is ``threaded'' in the calls to the
4565 @code{package->derivation} and @code{gexp->derivation} monadic
4566 procedures, and the monadic value returned by @code{package->derivation}
4567 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
4569 As it turns out, the call to @code{package->derivation} can even be
4570 omitted since it will take place implicitly, as we will see later
4571 (@pxref{G-Expressions}):
4574 (define (sh-symlink)
4575 (gexp->derivation "sh"
4576 #~(symlink (string-append #$bash "/bin/bash")
4581 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
4582 @c for the funny quote.
4583 Calling the monadic @code{sh-symlink} has no effect. As someone once
4584 said, ``you exit a monad like you exit a building on fire: by running''.
4585 So, to exit the monad and get the desired effect, one must use
4586 @code{run-with-store}:
4589 (run-with-store (open-connection) (sh-symlink))
4590 @result{} /gnu/store/...-sh-symlink
4593 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
4594 new ``meta-commands'' to make it easier to deal with monadic procedures:
4595 @code{run-in-store}, and @code{enter-store-monad}. The former is used
4596 to ``run'' a single monadic value through the store:
4599 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
4600 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
4603 The latter enters a recursive REPL, where all the return values are
4604 automatically run through the store:
4607 scheme@@(guile-user)> ,enter-store-monad
4608 store-monad@@(guile-user) [1]> (package->derivation hello)
4609 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
4610 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
4611 $3 = "/gnu/store/@dots{}-foo"
4612 store-monad@@(guile-user) [1]> ,q
4613 scheme@@(guile-user)>
4617 Note that non-monadic values cannot be returned in the
4618 @code{store-monad} REPL.
4620 The main syntactic forms to deal with monads in general are provided by
4621 the @code{(guix monads)} module and are described below.
4623 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
4624 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
4628 @deffn {Scheme Syntax} return @var{val}
4629 Return a monadic value that encapsulates @var{val}.
4632 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
4633 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
4634 procedures @var{mproc}@dots{}@footnote{This operation is commonly
4635 referred to as ``bind'', but that name denotes an unrelated procedure in
4636 Guile. Thus we use this somewhat cryptic symbol inherited from the
4637 Haskell language.}. There can be one @var{mproc} or several of them, as
4642 (with-monad %state-monad
4644 (lambda (x) (return (+ 1 x)))
4645 (lambda (x) (return (* 2 x)))))
4649 @result{} some-state
4653 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
4655 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
4657 Bind the variables @var{var} to the monadic values @var{mval} in
4658 @var{body}, which is a sequence of expressions. As with the bind
4659 operator, this can be thought of as ``unpacking'' the raw, non-monadic
4660 value ``contained'' in @var{mval} and making @var{var} refer to that
4661 raw, non-monadic value within the scope of the @var{body}. The form
4662 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
4663 @var{val}, as per @code{let}. The binding operations occur in sequence
4664 from left to right. The last expression of @var{body} must be a monadic
4665 expression, and its result will become the result of the @code{mlet} or
4666 @code{mlet*} when run in the @var{monad}.
4668 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
4669 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
4672 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
4673 Bind @var{mexp} and the following monadic expressions in sequence,
4674 returning the result of the last expression. Every expression in the
4675 sequence must be a monadic expression.
4677 This is akin to @code{mlet}, except that the return values of the
4678 monadic expressions are ignored. In that sense, it is analogous to
4679 @code{begin}, but applied to monadic expressions.
4682 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
4683 When @var{condition} is true, evaluate the sequence of monadic
4684 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
4685 @var{condition} is false, return @code{*unspecified*} in the current
4686 monad. Every expression in the sequence must be a monadic expression.
4689 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
4690 When @var{condition} is false, evaluate the sequence of monadic
4691 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
4692 @var{condition} is true, return @code{*unspecified*} in the current
4693 monad. Every expression in the sequence must be a monadic expression.
4697 The @code{(guix monads)} module provides the @dfn{state monad}, which
4698 allows an additional value---the state---to be @emph{threaded} through
4699 monadic procedure calls.
4701 @defvr {Scheme Variable} %state-monad
4702 The state monad. Procedures in the state monad can access and change
4703 the state that is threaded.
4705 Consider the example below. The @code{square} procedure returns a value
4706 in the state monad. It returns the square of its argument, but also
4707 increments the current state value:
4711 (mlet %state-monad ((count (current-state)))
4712 (mbegin %state-monad
4713 (set-current-state (+ 1 count))
4716 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
4721 When ``run'' through @var{%state-monad}, we obtain that additional state
4722 value, which is the number of @code{square} calls.
4725 @deffn {Monadic Procedure} current-state
4726 Return the current state as a monadic value.
4729 @deffn {Monadic Procedure} set-current-state @var{value}
4730 Set the current state to @var{value} and return the previous state as a
4734 @deffn {Monadic Procedure} state-push @var{value}
4735 Push @var{value} to the current state, which is assumed to be a list,
4736 and return the previous state as a monadic value.
4739 @deffn {Monadic Procedure} state-pop
4740 Pop a value from the current state and return it as a monadic value.
4741 The state is assumed to be a list.
4744 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
4745 Run monadic value @var{mval} starting with @var{state} as the initial
4746 state. Return two values: the resulting value, and the resulting state.
4749 The main interface to the store monad, provided by the @code{(guix
4750 store)} module, is as follows.
4752 @defvr {Scheme Variable} %store-monad
4753 The store monad---an alias for @var{%state-monad}.
4755 Values in the store monad encapsulate accesses to the store. When its
4756 effect is needed, a value of the store monad must be ``evaluated'' by
4757 passing it to the @code{run-with-store} procedure (see below.)
4760 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
4761 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
4762 open store connection.
4765 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
4766 Return as a monadic value the absolute file name in the store of the file
4767 containing @var{text}, a string. @var{references} is a list of store items that the
4768 resulting text file refers to; it defaults to the empty list.
4771 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
4772 [#:recursive? #t] [#:select? (const #t)]
4773 Return the name of @var{file} once interned in the store. Use
4774 @var{name} as its store name, or the basename of @var{file} if
4775 @var{name} is omitted.
4777 When @var{recursive?} is true, the contents of @var{file} are added
4778 recursively; if @var{file} designates a flat file and @var{recursive?}
4779 is true, its contents are added, and its permission bits are kept.
4781 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
4782 @var{stat})} for each directory entry, where @var{file} is the entry's
4783 absolute file name and @var{stat} is the result of @code{lstat}; exclude
4784 entries for which @var{select?} does not return true.
4786 The example below adds a file to the store, under two different names:
4789 (run-with-store (open-connection)
4790 (mlet %store-monad ((a (interned-file "README"))
4791 (b (interned-file "README" "LEGU-MIN")))
4792 (return (list a b))))
4794 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
4799 The @code{(guix packages)} module exports the following package-related
4802 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
4803 [#:system (%current-system)] [#:target #f] @
4806 value in the absolute file name of @var{file} within the @var{output}
4807 directory of @var{package}. When @var{file} is omitted, return the name
4808 of the @var{output} directory of @var{package}. When @var{target} is
4809 true, use it as a cross-compilation target triplet.
4812 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
4813 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
4814 @var{target} [@var{system}]
4815 Monadic version of @code{package-derivation} and
4816 @code{package-cross-derivation} (@pxref{Defining Packages}).
4821 @section G-Expressions
4823 @cindex G-expression
4824 @cindex build code quoting
4825 So we have ``derivations'', which represent a sequence of build actions
4826 to be performed to produce an item in the store (@pxref{Derivations}).
4827 These build actions are performed when asking the daemon to actually
4828 build the derivations; they are run by the daemon in a container
4829 (@pxref{Invoking guix-daemon}).
4831 @cindex strata of code
4832 It should come as no surprise that we like to write these build actions
4833 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
4834 code@footnote{The term @dfn{stratum} in this context was coined by
4835 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
4836 Kiselyov, who has written insightful
4837 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
4838 on this topic}, refers to this kind of code generation as
4839 @dfn{staging}.}: the ``host code''---code that defines packages, talks
4840 to the daemon, etc.---and the ``build code''---code that actually
4841 performs build actions, such as making directories, invoking
4842 @command{make}, etc.
4844 To describe a derivation and its build actions, one typically needs to
4845 embed build code inside host code. It boils down to manipulating build
4846 code as data, and the homoiconicity of Scheme---code has a direct
4847 representation as data---comes in handy for that. But we need more than
4848 the normal @code{quasiquote} mechanism in Scheme to construct build
4851 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
4852 S-expressions adapted to build expressions. G-expressions, or
4853 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
4854 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
4855 @code{#$}, and @code{#$@@}), which are comparable to
4856 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
4857 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
4858 GNU Guile Reference Manual}). However, there are major differences:
4862 Gexps are meant to be written to a file and run or manipulated by other
4866 When a high-level object such as a package or derivation is unquoted
4867 inside a gexp, the result is as if its output file name had been
4871 Gexps carry information about the packages or derivations they refer to,
4872 and these dependencies are automatically added as inputs to the build
4873 processes that use them.
4876 @cindex lowering, of high-level objects in gexps
4877 This mechanism is not limited to package and derivation
4878 objects: @dfn{compilers} able to ``lower'' other high-level objects to
4879 derivations or files in the store can be defined,
4880 such that these objects can also be inserted
4881 into gexps. For example, a useful type of high-level objects that can be
4882 inserted in a gexp is ``file-like objects'', which make it easy to
4883 add files to the store and to refer to them in
4884 derivations and such (see @code{local-file} and @code{plain-file}
4887 To illustrate the idea, here is an example of a gexp:
4894 (symlink (string-append #$coreutils "/bin/ls")
4898 This gexp can be passed to @code{gexp->derivation}; we obtain a
4899 derivation that builds a directory containing exactly one symlink to
4900 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
4903 (gexp->derivation "the-thing" build-exp)
4906 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
4907 substituted to the reference to the @var{coreutils} package in the
4908 actual build code, and @var{coreutils} is automatically made an input to
4909 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
4910 output)}) is replaced by a string containing the directory name of the
4911 output of the derivation.
4913 @cindex cross compilation
4914 In a cross-compilation context, it is useful to distinguish between
4915 references to the @emph{native} build of a package---that can run on the
4916 host---versus references to cross builds of a package. To that end, the
4917 @code{#+} plays the same role as @code{#$}, but is a reference to a
4918 native package build:
4921 (gexp->derivation "vi"
4924 (system* (string-append #+coreutils "/bin/ln")
4926 (string-append #$emacs "/bin/emacs")
4927 (string-append #$output "/bin/vi")))
4928 #:target "mips64el-linux-gnu")
4932 In the example above, the native build of @var{coreutils} is used, so
4933 that @command{ln} can actually run on the host; but then the
4934 cross-compiled build of @var{emacs} is referenced.
4936 @cindex imported modules, for gexps
4937 @findex with-imported-modules
4938 Another gexp feature is @dfn{imported modules}: sometimes you want to be
4939 able to use certain Guile modules from the ``host environment'' in the
4940 gexp, so those modules should be imported in the ``build environment''.
4941 The @code{with-imported-modules} form allows you to express that:
4944 (let ((build (with-imported-modules '((guix build utils))
4946 (use-modules (guix build utils))
4947 (mkdir-p (string-append #$output "/bin"))))))
4948 (gexp->derivation "empty-dir"
4951 (display "success!\n")
4956 In this example, the @code{(guix build utils)} module is automatically
4957 pulled into the isolated build environment of our gexp, such that
4958 @code{(use-modules (guix build utils))} works as expected.
4960 @cindex module closure
4961 @findex source-module-closure
4962 Usually you want the @emph{closure} of the module to be imported---i.e.,
4963 the module itself and all the modules it depends on---rather than just
4964 the module; failing to do that, attempts to use the module will fail
4965 because of missing dependent modules. The @code{source-module-closure}
4966 procedure computes the closure of a module by looking at its source file
4967 headers, which comes in handy in this case:
4970 (use-modules (guix modules)) ;for 'source-module-closure'
4972 (with-imported-modules (source-module-closure
4973 '((guix build utils)
4975 (gexp->derivation "something-with-vms"
4977 (use-modules (guix build utils)
4982 The syntactic form to construct gexps is summarized below.
4984 @deffn {Scheme Syntax} #~@var{exp}
4985 @deffnx {Scheme Syntax} (gexp @var{exp})
4986 Return a G-expression containing @var{exp}. @var{exp} may contain one
4987 or more of the following forms:
4991 @itemx (ungexp @var{obj})
4992 Introduce a reference to @var{obj}. @var{obj} may have one of the
4993 supported types, for example a package or a
4994 derivation, in which case the @code{ungexp} form is replaced by its
4995 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
4997 If @var{obj} is a list, it is traversed and references to supported
4998 objects are substituted similarly.
5000 If @var{obj} is another gexp, its contents are inserted and its
5001 dependencies are added to those of the containing gexp.
5003 If @var{obj} is another kind of object, it is inserted as is.
5005 @item #$@var{obj}:@var{output}
5006 @itemx (ungexp @var{obj} @var{output})
5007 This is like the form above, but referring explicitly to the
5008 @var{output} of @var{obj}---this is useful when @var{obj} produces
5009 multiple outputs (@pxref{Packages with Multiple Outputs}).
5012 @itemx #+@var{obj}:output
5013 @itemx (ungexp-native @var{obj})
5014 @itemx (ungexp-native @var{obj} @var{output})
5015 Same as @code{ungexp}, but produces a reference to the @emph{native}
5016 build of @var{obj} when used in a cross compilation context.
5018 @item #$output[:@var{output}]
5019 @itemx (ungexp output [@var{output}])
5020 Insert a reference to derivation output @var{output}, or to the main
5021 output when @var{output} is omitted.
5023 This only makes sense for gexps passed to @code{gexp->derivation}.
5026 @itemx (ungexp-splicing @var{lst})
5027 Like the above, but splices the contents of @var{lst} inside the
5031 @itemx (ungexp-native-splicing @var{lst})
5032 Like the above, but refers to native builds of the objects listed in
5037 G-expressions created by @code{gexp} or @code{#~} are run-time objects
5038 of the @code{gexp?} type (see below.)
5041 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
5042 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
5043 in their execution environment.
5045 Each item in @var{modules} can be the name of a module, such as
5046 @code{(guix build utils)}, or it can be a module name, followed by an
5047 arrow, followed by a file-like object:
5050 `((guix build utils)
5052 ((guix config) => ,(scheme-file "config.scm"
5053 #~(define-module @dots{}))))
5057 In the example above, the first two modules are taken from the search
5058 path, and the last one is created from the given file-like object.
5060 This form has @emph{lexical} scope: it has an effect on the gexps
5061 directly defined in @var{body}@dots{}, but not on those defined, say, in
5062 procedures called from @var{body}@dots{}.
5065 @deffn {Scheme Procedure} gexp? @var{obj}
5066 Return @code{#t} if @var{obj} is a G-expression.
5069 G-expressions are meant to be written to disk, either as code building
5070 some derivation, or as plain files in the store. The monadic procedures
5071 below allow you to do that (@pxref{The Store Monad}, for more
5072 information about monads.)
5074 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
5075 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
5076 [#:hash #f] [#:hash-algo #f] @
5077 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
5078 [#:module-path @var{%load-path}] @
5079 [#:references-graphs #f] [#:allowed-references #f] @
5080 [#:disallowed-references #f] @
5081 [#:leaked-env-vars #f] @
5082 [#:script-name (string-append @var{name} "-builder")] @
5083 [#:deprecation-warnings #f] @
5084 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
5085 Return a derivation @var{name} that runs @var{exp} (a gexp) with
5086 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
5087 stored in a file called @var{script-name}. When @var{target} is true,
5088 it is used as the cross-compilation target triplet for packages referred
5091 @var{modules} is deprecated in favor of @code{with-imported-modules}.
5093 make @var{modules} available in the evaluation context of @var{exp};
5094 @var{modules} is a list of names of Guile modules searched in
5095 @var{module-path} to be copied in the store, compiled, and made available in
5096 the load path during the execution of @var{exp}---e.g., @code{((guix
5097 build utils) (guix build gnu-build-system))}.
5099 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
5102 When @var{references-graphs} is true, it must be a list of tuples of one of the
5106 (@var{file-name} @var{package})
5107 (@var{file-name} @var{package} @var{output})
5108 (@var{file-name} @var{derivation})
5109 (@var{file-name} @var{derivation} @var{output})
5110 (@var{file-name} @var{store-item})
5113 The right-hand-side of each element of @var{references-graphs} is automatically made
5114 an input of the build process of @var{exp}. In the build environment, each
5115 @var{file-name} contains the reference graph of the corresponding item, in a simple
5118 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
5119 In the latter case, the list denotes store items that the result is allowed to
5120 refer to. Any reference to another store item will lead to a build error.
5121 Similarly for @var{disallowed-references}, which can list items that must not be
5122 referenced by the outputs.
5124 @var{deprecation-warnings} determines whether to show deprecation warnings while
5125 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
5127 The other arguments are as for @code{derivation} (@pxref{Derivations}).
5130 @cindex file-like objects
5131 The @code{local-file}, @code{plain-file}, @code{computed-file},
5132 @code{program-file}, and @code{scheme-file} procedures below return
5133 @dfn{file-like objects}. That is, when unquoted in a G-expression,
5134 these objects lead to a file in the store. Consider this G-expression:
5137 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
5138 #$(local-file "/tmp/my-nscd.conf"))
5141 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
5142 to the store. Once expanded, for instance @i{via}
5143 @code{gexp->derivation}, the G-expression refers to that copy under
5144 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
5145 does not have any effect on what the G-expression does.
5146 @code{plain-file} can be used similarly; it differs in that the file
5147 content is directly passed as a string.
5149 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
5150 [#:recursive? #f] [#:select? (const #t)]
5151 Return an object representing local file @var{file} to add to the store; this
5152 object can be used in a gexp. If @var{file} is a relative file name, it is looked
5153 up relative to the source file where this form appears. @var{file} will be added to
5154 the store under @var{name}--by default the base name of @var{file}.
5156 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
5157 designates a flat file and @var{recursive?} is true, its contents are added, and its
5158 permission bits are kept.
5160 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
5161 @var{stat})} for each directory entry, where @var{file} is the entry's
5162 absolute file name and @var{stat} is the result of @code{lstat}; exclude
5163 entries for which @var{select?} does not return true.
5165 This is the declarative counterpart of the @code{interned-file} monadic
5166 procedure (@pxref{The Store Monad, @code{interned-file}}).
5169 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
5170 Return an object representing a text file called @var{name} with the given
5171 @var{content} (a string) to be added to the store.
5173 This is the declarative counterpart of @code{text-file}.
5176 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
5177 [#:options '(#:local-build? #t)]
5178 Return an object representing the store item @var{name}, a file or
5179 directory computed by @var{gexp}. @var{options}
5180 is a list of additional arguments to pass to @code{gexp->derivation}.
5182 This is the declarative counterpart of @code{gexp->derivation}.
5185 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
5186 [#:guile (default-guile)] [#:module-path %load-path]
5187 Return an executable script @var{name} that runs @var{exp} using
5188 @var{guile}, with @var{exp}'s imported modules in its search path.
5189 Look up @var{exp}'s modules in @var{module-path}.
5191 The example below builds a script that simply invokes the @command{ls}
5195 (use-modules (guix gexp) (gnu packages base))
5197 (gexp->script "list-files"
5198 #~(execl #$(file-append coreutils "/bin/ls")
5202 When ``running'' it through the store (@pxref{The Store Monad,
5203 @code{run-with-store}}), we obtain a derivation that produces an
5204 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
5207 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
5209 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
5213 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
5214 [#:guile #f] [#:module-path %load-path]
5215 Return an object representing the executable store item @var{name} that
5216 runs @var{gexp}. @var{guile} is the Guile package used to execute that
5217 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
5219 This is the declarative counterpart of @code{gexp->script}.
5222 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
5223 [#:set-load-path? #t] [#:module-path %load-path] @
5225 [#:guile (default-guile)]
5226 Return a derivation that builds a file @var{name} containing @var{exp}.
5227 When @var{splice?} is true, @var{exp} is considered to be a list of
5228 expressions that will be spliced in the resulting file.
5230 When @var{set-load-path?} is true, emit code in the resulting file to
5231 set @code{%load-path} and @code{%load-compiled-path} to honor
5232 @var{exp}'s imported modules. Look up @var{exp}'s modules in
5235 The resulting file holds references to all the dependencies of @var{exp}
5236 or a subset thereof.
5239 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
5240 Return an object representing the Scheme file @var{name} that contains
5243 This is the declarative counterpart of @code{gexp->file}.
5246 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
5247 Return as a monadic value a derivation that builds a text file
5248 containing all of @var{text}. @var{text} may list, in addition to
5249 strings, objects of any type that can be used in a gexp: packages,
5250 derivations, local file objects, etc. The resulting store file holds
5251 references to all these.
5253 This variant should be preferred over @code{text-file} anytime the file
5254 to create will reference items from the store. This is typically the
5255 case when building a configuration file that embeds store file names,
5259 (define (profile.sh)
5260 ;; Return the name of a shell script in the store that
5261 ;; initializes the 'PATH' environment variable.
5262 (text-file* "profile.sh"
5263 "export PATH=" coreutils "/bin:"
5264 grep "/bin:" sed "/bin\n"))
5267 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
5268 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
5269 preventing them from being garbage-collected during its lifetime.
5272 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
5273 Return an object representing store file @var{name} containing
5274 @var{text}. @var{text} is a sequence of strings and file-like objects,
5278 (mixed-text-file "profile"
5279 "export PATH=" coreutils "/bin:" grep "/bin")
5282 This is the declarative counterpart of @code{text-file*}.
5285 @deffn {Scheme Procedure} file-union @var{name} @var{files}
5286 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
5287 Each item in @var{files} must be a two-element list where the first element is the
5288 file name to use in the new directory, and the second element is a gexp
5289 denoting the target file. Here's an example:
5293 `(("hosts" ,(plain-file "hosts"
5294 "127.0.0.1 localhost"))
5295 ("bashrc" ,(plain-file "bashrc"
5296 "alias ls='ls --color'"))))
5299 This yields an @code{etc} directory containing these two files.
5302 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
5303 Return a directory that is the union of @var{things}, where @var{things} is a list of
5304 file-like objects denoting directories. For example:
5307 (directory-union "guile+emacs" (list guile emacs))
5310 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
5313 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
5314 Return a file-like object that expands to the concatenation of @var{obj}
5315 and @var{suffix}, where @var{obj} is a lowerable object and each
5316 @var{suffix} is a string.
5318 As an example, consider this gexp:
5321 (gexp->script "run-uname"
5322 #~(system* #$(file-append coreutils
5326 The same effect could be achieved with:
5329 (gexp->script "run-uname"
5330 #~(system* (string-append #$coreutils
5334 There is one difference though: in the @code{file-append} case, the
5335 resulting script contains the absolute file name as a string, whereas in
5336 the second case, the resulting script contains a @code{(string-append
5337 @dots{})} expression to construct the file name @emph{at run time}.
5341 Of course, in addition to gexps embedded in ``host'' code, there are
5342 also modules containing build tools. To make it clear that they are
5343 meant to be used in the build stratum, these modules are kept in the
5344 @code{(guix build @dots{})} name space.
5346 @cindex lowering, of high-level objects in gexps
5347 Internally, high-level objects are @dfn{lowered}, using their compiler,
5348 to either derivations or store items. For instance, lowering a package
5349 yields a derivation, and lowering a @code{plain-file} yields a store
5350 item. This is achieved using the @code{lower-object} monadic procedure.
5352 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
5354 Return as a value in @var{%store-monad} the derivation or store item
5355 corresponding to @var{obj} for @var{system}, cross-compiling for
5356 @var{target} if @var{target} is true. @var{obj} must be an object that
5357 has an associated gexp compiler, such as a @code{<package>}.
5361 @c *********************************************************************
5365 This section describes Guix command-line utilities. Some of them are
5366 primarily targeted at developers and users who write new package
5367 definitions, while others are more generally useful. They complement
5368 the Scheme programming interface of Guix in a convenient way.
5371 * Invoking guix build:: Building packages from the command line.
5372 * Invoking guix edit:: Editing package definitions.
5373 * Invoking guix download:: Downloading a file and printing its hash.
5374 * Invoking guix hash:: Computing the cryptographic hash of a file.
5375 * Invoking guix import:: Importing package definitions.
5376 * Invoking guix refresh:: Updating package definitions.
5377 * Invoking guix lint:: Finding errors in package definitions.
5378 * Invoking guix size:: Profiling disk usage.
5379 * Invoking guix graph:: Visualizing the graph of packages.
5380 * Invoking guix environment:: Setting up development environments.
5381 * Invoking guix publish:: Sharing substitutes.
5382 * Invoking guix challenge:: Challenging substitute servers.
5383 * Invoking guix copy:: Copying to and from a remote store.
5384 * Invoking guix container:: Process isolation.
5385 * Invoking guix weather:: Assessing substitute availability.
5388 @node Invoking guix build
5389 @section Invoking @command{guix build}
5391 @cindex package building
5392 @cindex @command{guix build}
5393 The @command{guix build} command builds packages or derivations and
5394 their dependencies, and prints the resulting store paths. Note that it
5395 does not modify the user's profile---this is the job of the
5396 @command{guix package} command (@pxref{Invoking guix package}). Thus,
5397 it is mainly useful for distribution developers.
5399 The general syntax is:
5402 guix build @var{options} @var{package-or-derivation}@dots{}
5405 As an example, the following command builds the latest versions of Emacs
5406 and of Guile, displays their build logs, and finally displays the
5407 resulting directories:
5410 guix build emacs guile
5413 Similarly, the following command builds all the available packages:
5416 guix build --quiet --keep-going \
5417 `guix package -A | cut -f1,2 --output-delimiter=@@`
5420 @var{package-or-derivation} may be either the name of a package found in
5421 the software distribution such as @code{coreutils} or
5422 @code{coreutils@@8.20}, or a derivation such as
5423 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
5424 package with the corresponding name (and optionally version) is searched
5425 for among the GNU distribution modules (@pxref{Package Modules}).
5427 Alternatively, the @code{--expression} option may be used to specify a
5428 Scheme expression that evaluates to a package; this is useful when
5429 disambiguating among several same-named packages or package variants is
5432 There may be zero or more @var{options}. The available options are
5433 described in the subsections below.
5436 * Common Build Options:: Build options for most commands.
5437 * Package Transformation Options:: Creating variants of packages.
5438 * Additional Build Options:: Options specific to 'guix build'.
5439 * Debugging Build Failures:: Real life packaging experience.
5442 @node Common Build Options
5443 @subsection Common Build Options
5445 A number of options that control the build process are common to
5446 @command{guix build} and other commands that can spawn builds, such as
5447 @command{guix package} or @command{guix archive}. These are the
5452 @item --load-path=@var{directory}
5453 @itemx -L @var{directory}
5454 Add @var{directory} to the front of the package module search path
5455 (@pxref{Package Modules}).
5457 This allows users to define their own packages and make them visible to
5458 the command-line tools.
5462 Keep the build tree of failed builds. Thus, if a build fails, its build
5463 tree is kept under @file{/tmp}, in a directory whose name is shown at
5464 the end of the build log. This is useful when debugging build issues.
5465 @xref{Debugging Build Failures}, for tips and tricks on how to debug
5470 Keep going when some of the derivations fail to build; return only once
5471 all the builds have either completed or failed.
5473 The default behavior is to stop as soon as one of the specified
5474 derivations has failed.
5478 Do not build the derivations.
5480 @anchor{fallback-option}
5482 When substituting a pre-built binary fails, fall back to building
5483 packages locally (@pxref{Substitution Failure}).
5485 @item --substitute-urls=@var{urls}
5486 @anchor{client-substitute-urls}
5487 Consider @var{urls} the whitespace-separated list of substitute source
5488 URLs, overriding the default list of URLs of @command{guix-daemon}
5489 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
5491 This means that substitutes may be downloaded from @var{urls}, provided
5492 they are signed by a key authorized by the system administrator
5493 (@pxref{Substitutes}).
5495 When @var{urls} is the empty string, substitutes are effectively
5498 @item --no-substitutes
5499 Do not use substitutes for build products. That is, always build things
5500 locally instead of allowing downloads of pre-built binaries
5501 (@pxref{Substitutes}).
5504 Do not ``graft'' packages. In practice, this means that package updates
5505 available as grafts are not applied. @xref{Security Updates}, for more
5506 information on grafts.
5508 @item --rounds=@var{n}
5509 Build each derivation @var{n} times in a row, and raise an error if
5510 consecutive build results are not bit-for-bit identical.
5512 This is a useful way to detect non-deterministic builds processes.
5513 Non-deterministic build processes are a problem because they make it
5514 practically impossible for users to @emph{verify} whether third-party
5515 binaries are genuine. @xref{Invoking guix challenge}, for more.
5517 Note that, currently, the differing build results are not kept around,
5518 so you will have to manually investigate in case of an error---e.g., by
5519 stashing one of the build results with @code{guix archive --export}
5520 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
5523 @item --no-build-hook
5524 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
5525 (@pxref{Daemon Offload Setup}). That is, always build things locally
5526 instead of offloading builds to remote machines.
5528 @item --max-silent-time=@var{seconds}
5529 When the build or substitution process remains silent for more than
5530 @var{seconds}, terminate it and report a build failure.
5532 By default, the daemon's setting is honored (@pxref{Invoking
5533 guix-daemon, @code{--max-silent-time}}).
5535 @item --timeout=@var{seconds}
5536 Likewise, when the build or substitution process lasts for more than
5537 @var{seconds}, terminate it and report a build failure.
5539 By default, the daemon's setting is honored (@pxref{Invoking
5540 guix-daemon, @code{--timeout}}).
5542 @item --verbosity=@var{level}
5543 Use the given verbosity level. @var{level} must be an integer between 0
5544 and 5; higher means more verbose output. Setting a level of 4 or more
5545 may be helpful when debugging setup issues with the build daemon.
5547 @item --cores=@var{n}
5549 Allow the use of up to @var{n} CPU cores for the build. The special
5550 value @code{0} means to use as many CPU cores as available.
5552 @item --max-jobs=@var{n}
5554 Allow at most @var{n} build jobs in parallel. @xref{Invoking
5555 guix-daemon, @code{--max-jobs}}, for details about this option and the
5556 equivalent @command{guix-daemon} option.
5560 Behind the scenes, @command{guix build} is essentially an interface to
5561 the @code{package-derivation} procedure of the @code{(guix packages)}
5562 module, and to the @code{build-derivations} procedure of the @code{(guix
5563 derivations)} module.
5565 In addition to options explicitly passed on the command line,
5566 @command{guix build} and other @command{guix} commands that support
5567 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
5569 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
5570 Users can define this variable to a list of command line options that
5571 will automatically be used by @command{guix build} and other
5572 @command{guix} commands that can perform builds, as in the example
5576 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
5579 These options are parsed independently, and the result is appended to
5580 the parsed command-line options.
5584 @node Package Transformation Options
5585 @subsection Package Transformation Options
5587 @cindex package variants
5588 Another set of command-line options supported by @command{guix build}
5589 and also @command{guix package} are @dfn{package transformation
5590 options}. These are options that make it possible to define @dfn{package
5591 variants}---for instance, packages built from different source code.
5592 This is a convenient way to create customized packages on the fly
5593 without having to type in the definitions of package variants
5594 (@pxref{Defining Packages}).
5598 @item --with-source=@var{source}
5599 @itemx --with-source=@var{package}=@var{source}
5600 @itemx --with-source=@var{package}@@@var{version}=@var{source}
5601 Use @var{source} as the source of @var{package}, and @var{version} as
5603 @var{source} must be a file name or a URL, as for @command{guix
5604 download} (@pxref{Invoking guix download}).
5606 When @var{package} is omitted,
5607 it is taken to be the package name specified on the
5608 command line that matches the base of @var{source}---e.g.,
5609 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
5610 package is @code{guile}.
5612 Likewise, when @var{version} is omitted, the version string is inferred from
5613 @var{source}; in the previous example, it is @code{2.0.10}.
5615 This option allows users to try out versions of packages other than the
5616 one provided by the distribution. The example below downloads
5617 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
5618 the @code{ed} package:
5621 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
5624 As a developer, @code{--with-source} makes it easy to test release
5628 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
5631 @dots{} or to build from a checkout in a pristine environment:
5634 $ git clone git://git.sv.gnu.org/guix.git
5635 $ guix build guix --with-source=guix@@1.0=./guix
5638 @item --with-input=@var{package}=@var{replacement}
5639 Replace dependency on @var{package} by a dependency on
5640 @var{replacement}. @var{package} must be a package name, and
5641 @var{replacement} must be a package specification such as @code{guile}
5642 or @code{guile@@1.8}.
5644 For instance, the following command builds Guix, but replaces its
5645 dependency on the current stable version of Guile with a dependency on
5646 the legacy version of Guile, @code{guile@@2.0}:
5649 guix build --with-input=guile=guile@@2.0 guix
5652 This is a recursive, deep replacement. So in this example, both
5653 @code{guix} and its dependency @code{guile-json} (which also depends on
5654 @code{guile}) get rebuilt against @code{guile@@2.0}.
5656 This is implemented using the @code{package-input-rewriting} Scheme
5657 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
5659 @item --with-graft=@var{package}=@var{replacement}
5660 This is similar to @code{--with-input} but with an important difference:
5661 instead of rebuilding the whole dependency chain, @var{replacement} is
5662 built and then @dfn{grafted} onto the binaries that were initially
5663 referring to @var{package}. @xref{Security Updates}, for more
5664 information on grafts.
5666 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
5667 and all its dependencies, replacing references to the version of GnuTLS
5668 they currently refer to:
5671 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
5674 This has the advantage of being much faster than rebuilding everything.
5675 But there is a caveat: it works if and only if @var{package} and
5676 @var{replacement} are strictly compatible---for example, if they provide
5677 a library, the application binary interface (ABI) of those libraries
5678 must be compatible. If @var{replacement} is somehow incompatible with
5679 @var{package}, then the resulting package may be unusable. Use with
5684 @node Additional Build Options
5685 @subsection Additional Build Options
5687 The command-line options presented below are specific to @command{guix
5694 Build quietly, without displaying the build log. Upon completion, the
5695 build log is kept in @file{/var} (or similar) and can always be
5696 retrieved using the @option{--log-file} option.
5698 @item --file=@var{file}
5699 @itemx -f @var{file}
5701 Build the package or derivation that the code within @var{file}
5704 As an example, @var{file} might contain a package definition like this
5705 (@pxref{Defining Packages}):
5708 @verbatiminclude package-hello.scm
5711 @item --expression=@var{expr}
5712 @itemx -e @var{expr}
5713 Build the package or derivation @var{expr} evaluates to.
5715 For example, @var{expr} may be @code{(@@ (gnu packages guile)
5716 guile-1.8)}, which unambiguously designates this specific variant of
5717 version 1.8 of Guile.
5719 Alternatively, @var{expr} may be a G-expression, in which case it is used
5720 as a build program passed to @code{gexp->derivation}
5721 (@pxref{G-Expressions}).
5723 Lastly, @var{expr} may refer to a zero-argument monadic procedure
5724 (@pxref{The Store Monad}). The procedure must return a derivation as a
5725 monadic value, which is then passed through @code{run-with-store}.
5729 Build the source derivations of the packages, rather than the packages
5732 For instance, @code{guix build -S gcc} returns something like
5733 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
5736 The returned source tarball is the result of applying any patches and
5737 code snippets specified in the package @code{origin} (@pxref{Defining
5741 Fetch and return the source of @var{package-or-derivation} and all their
5742 dependencies, recursively. This is a handy way to obtain a local copy
5743 of all the source code needed to build @var{packages}, allowing you to
5744 eventually build them even without network access. It is an extension
5745 of the @code{--source} option and can accept one of the following
5746 optional argument values:
5750 This value causes the @code{--sources} option to behave in the same way
5751 as the @code{--source} option.
5754 Build the source derivations of all packages, including any source that
5755 might be listed as @code{inputs}. This is the default value.
5758 $ guix build --sources tzdata
5759 The following derivations will be built:
5760 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
5761 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
5765 Build the source derivations of all packages, as well of all transitive
5766 inputs to the packages. This can be used e.g. to
5767 prefetch package source for later offline building.
5770 $ guix build --sources=transitive tzdata
5771 The following derivations will be built:
5772 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
5773 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
5774 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
5775 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
5776 /gnu/store/@dots{}-make-4.1.tar.xz.drv
5777 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
5783 @item --system=@var{system}
5784 @itemx -s @var{system}
5785 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5786 the system type of the build host.
5789 The @code{--system} flag is for @emph{native} compilation and must not
5790 be confused with cross-compilation. See @code{--target} below for
5791 information on cross-compilation.
5794 An example use of this is on Linux-based systems, which can emulate
5795 different personalities. For instance, passing
5796 @code{--system=i686-linux} on an @code{x86_64-linux} system allows you
5797 to build packages in a complete 32-bit environment.
5799 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
5800 is enabled (@pxref{Virtualization Services,
5801 @code{qemu-binfmt-service-type}}), you can build for any system for
5802 which a QEMU @code{binfmt_misc} handler is installed.
5804 Builds for a system other than that of the machine you are using can
5805 also be offloaded to a remote machine of the right architecture.
5806 @xref{Daemon Offload Setup}, for more information on offloading.
5808 @item --target=@var{triplet}
5809 @cindex cross-compilation
5810 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5811 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
5812 configuration triplets,, autoconf, Autoconf}).
5814 @anchor{build-check}
5816 @cindex determinism, checking
5817 @cindex reproducibility, checking
5818 Rebuild @var{package-or-derivation}, which are already available in the
5819 store, and raise an error if the build results are not bit-for-bit
5822 This mechanism allows you to check whether previously installed
5823 substitutes are genuine (@pxref{Substitutes}), or whether the build result
5824 of a package is deterministic. @xref{Invoking guix challenge}, for more
5825 background information and tools.
5827 When used in conjunction with @option{--keep-failed}, the differing
5828 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
5829 This makes it easy to look for differences between the two results.
5832 @cindex repairing store items
5833 @cindex corruption, recovering from
5834 Attempt to repair the specified store items, if they are corrupt, by
5835 re-downloading or rebuilding them.
5837 This operation is not atomic and thus restricted to @code{root}.
5841 Return the derivation paths, not the output paths, of the given
5844 @item --root=@var{file}
5845 @itemx -r @var{file}
5846 @cindex GC roots, adding
5847 @cindex garbage collector roots, adding
5848 Make @var{file} a symlink to the result, and register it as a garbage
5851 Consequently, the results of this @command{guix build} invocation are
5852 protected from garbage collection until @var{file} is removed. When
5853 that option is omitted, build results are eligible for garbage
5854 collection as soon as the build completes. @xref{Invoking guix gc}, for
5858 @cindex build logs, access
5859 Return the build log file names or URLs for the given
5860 @var{package-or-derivation}, or raise an error if build logs are
5863 This works regardless of how packages or derivations are specified. For
5864 instance, the following invocations are equivalent:
5867 guix build --log-file `guix build -d guile`
5868 guix build --log-file `guix build guile`
5869 guix build --log-file guile
5870 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
5873 If a log is unavailable locally, and unless @code{--no-substitutes} is
5874 passed, the command looks for a corresponding log on one of the
5875 substitute servers (as specified with @code{--substitute-urls}.)
5877 So for instance, imagine you want to see the build log of GDB on MIPS,
5878 but you are actually on an @code{x86_64} machine:
5881 $ guix build --log-file gdb -s mips64el-linux
5882 https://hydra.gnu.org/log/@dots{}-gdb-7.10
5885 You can freely access a huge library of build logs!
5888 @node Debugging Build Failures
5889 @subsection Debugging Build Failures
5891 @cindex build failures, debugging
5892 When defining a new package (@pxref{Defining Packages}), you will
5893 probably find yourself spending some time debugging and tweaking the
5894 build until it succeeds. To do that, you need to operate the build
5895 commands yourself in an environment as close as possible to the one the
5898 To that end, the first thing to do is to use the @option{--keep-failed}
5899 or @option{-K} option of @command{guix build}, which will keep the
5900 failed build tree in @file{/tmp} or whatever directory you specified as
5901 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
5903 From there on, you can @command{cd} to the failed build tree and source
5904 the @file{environment-variables} file, which contains all the
5905 environment variable definitions that were in place when the build
5906 failed. So let's say you're debugging a build failure in package
5907 @code{foo}; a typical session would look like this:
5911 @dots{} @i{build fails}
5912 $ cd /tmp/guix-build-foo.drv-0
5913 $ source ./environment-variables
5917 Now, you can invoke commands as if you were the daemon (almost) and
5918 troubleshoot your build process.
5920 Sometimes it happens that, for example, a package's tests pass when you
5921 run them manually but they fail when the daemon runs them. This can
5922 happen because the daemon runs builds in containers where, unlike in our
5923 environment above, network access is missing, @file{/bin/sh} does not
5924 exist, etc. (@pxref{Build Environment Setup}).
5926 In such cases, you may need to run inspect the build process from within
5927 a container similar to the one the build daemon creates:
5932 $ cd /tmp/guix-build-foo.drv-0
5933 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
5934 [env]# source ./environment-variables
5938 Here, @command{guix environment -C} creates a container and spawns a new
5939 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
5940 strace gdb} part adds the @command{strace} and @command{gdb} commands to
5941 the container, which would may find handy while debugging. The
5942 @option{--no-grafts} option makes sure we get the exact same
5943 environment, with ungrafted packages (@pxref{Security Updates}, for more
5946 To get closer to a container like that used by the build daemon, we can
5947 remove @file{/bin/sh}:
5953 (Don't worry, this is harmless: this is all happening in the throw-away
5954 container created by @command{guix environment}.)
5956 The @command{strace} command is probably not in the search path, but we
5960 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
5963 In this way, not only you will have reproduced the environment variables
5964 the daemon uses, you will also be running the build process in a container
5965 similar to the one the daemon uses.
5968 @node Invoking guix edit
5969 @section Invoking @command{guix edit}
5971 @cindex @command{guix edit}
5972 @cindex package definition, editing
5973 So many packages, so many source files! The @command{guix edit} command
5974 facilitates the life of users and packagers by pointing their editor at
5975 the source file containing the definition of the specified packages.
5979 guix edit gcc@@4.9 vim
5983 launches the program specified in the @code{VISUAL} or in the
5984 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
5987 If you are using a Guix Git checkout (@pxref{Building from Git}), or
5988 have created your own packages on @code{GUIX_PACKAGE_PATH}
5989 (@pxref{Defining Packages}), you will be able to edit the package
5990 recipes. Otherwise, you will be able to examine the read-only recipes
5991 for packages currently in the store.
5994 @node Invoking guix download
5995 @section Invoking @command{guix download}
5997 @cindex @command{guix download}
5998 @cindex downloading package sources
5999 When writing a package definition, developers typically need to download
6000 a source tarball, compute its SHA256 hash, and write that
6001 hash in the package definition (@pxref{Defining Packages}). The
6002 @command{guix download} tool helps with this task: it downloads a file
6003 from the given URI, adds it to the store, and prints both its file name
6004 in the store and its SHA256 hash.
6006 The fact that the downloaded file is added to the store saves bandwidth:
6007 when the developer eventually tries to build the newly defined package
6008 with @command{guix build}, the source tarball will not have to be
6009 downloaded again because it is already in the store. It is also a
6010 convenient way to temporarily stash files, which may be deleted
6011 eventually (@pxref{Invoking guix gc}).
6013 The @command{guix download} command supports the same URIs as used in
6014 package definitions. In particular, it supports @code{mirror://} URIs.
6015 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
6016 Guile bindings for GnuTLS are available in the user's environment; when
6017 they are not available, an error is raised. @xref{Guile Preparations,
6018 how to install the GnuTLS bindings for Guile,, gnutls-guile,
6019 GnuTLS-Guile}, for more information.
6021 @command{guix download} verifies HTTPS server certificates by loading
6022 the certificates of X.509 authorities from the directory pointed to by
6023 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
6024 Certificates}), unless @option{--no-check-certificate} is used.
6026 The following options are available:
6029 @item --format=@var{fmt}
6031 Write the hash in the format specified by @var{fmt}. For more
6032 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
6034 @item --no-check-certificate
6035 Do not validate the X.509 certificates of HTTPS servers.
6037 When using this option, you have @emph{absolutely no guarantee} that you
6038 are communicating with the authentic server responsible for the given
6039 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
6041 @item --output=@var{file}
6042 @itemx -o @var{file}
6043 Save the downloaded file to @var{file} instead of adding it to the
6047 @node Invoking guix hash
6048 @section Invoking @command{guix hash}
6050 @cindex @command{guix hash}
6051 The @command{guix hash} command computes the SHA256 hash of a file.
6052 It is primarily a convenience tool for anyone contributing to the
6053 distribution: it computes the cryptographic hash of a file, which can be
6054 used in the definition of a package (@pxref{Defining Packages}).
6056 The general syntax is:
6059 guix hash @var{option} @var{file}
6062 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
6063 hash of data read from standard input. @command{guix hash} has the
6068 @item --format=@var{fmt}
6070 Write the hash in the format specified by @var{fmt}.
6072 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
6073 (@code{hex} and @code{hexadecimal} can be used as well).
6075 If the @option{--format} option is not specified, @command{guix hash}
6076 will output the hash in @code{nix-base32}. This representation is used
6077 in the definitions of packages.
6081 Compute the hash on @var{file} recursively.
6083 In this case, the hash is computed on an archive containing @var{file},
6084 including its children if it is a directory. Some of the metadata of
6085 @var{file} is part of the archive; for instance, when @var{file} is a
6086 regular file, the hash is different depending on whether @var{file} is
6087 executable or not. Metadata such as time stamps has no impact on the
6088 hash (@pxref{Invoking guix archive}).
6089 @c FIXME: Replace xref above with xref to an ``Archive'' section when
6094 When combined with @option{--recursive}, exclude version control system
6095 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
6098 As an example, here is how you would compute the hash of a Git checkout,
6099 which is useful when using the @code{git-fetch} method (@pxref{origin
6103 $ git clone http://example.org/foo.git
6109 @node Invoking guix import
6110 @section Invoking @command{guix import}
6112 @cindex importing packages
6113 @cindex package import
6114 @cindex package conversion
6115 @cindex Invoking @command{guix import}
6116 The @command{guix import} command is useful for people who would like to
6117 add a package to the distribution with as little work as
6118 possible---a legitimate demand. The command knows of a few
6119 repositories from which it can ``import'' package metadata. The result
6120 is a package definition, or a template thereof, in the format we know
6121 (@pxref{Defining Packages}).
6123 The general syntax is:
6126 guix import @var{importer} @var{options}@dots{}
6129 @var{importer} specifies the source from which to import package
6130 metadata, and @var{options} specifies a package identifier and other
6131 options specific to @var{importer}. Currently, the available
6136 Import metadata for the given GNU package. This provides a template
6137 for the latest version of that GNU package, including the hash of its
6138 source tarball, and its canonical synopsis and description.
6140 Additional information such as the package dependencies and its
6141 license needs to be figured out manually.
6143 For example, the following command returns a package definition for
6147 guix import gnu hello
6150 Specific command-line options are:
6153 @item --key-download=@var{policy}
6154 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
6155 keys when verifying the package signature. @xref{Invoking guix
6156 refresh, @code{--key-download}}.
6161 Import metadata from the @uref{https://pypi.python.org/, Python Package
6162 Index}@footnote{This functionality requires Guile-JSON to be installed.
6163 @xref{Requirements}.}. Information is taken from the JSON-formatted
6164 description available at @code{pypi.python.org} and usually includes all
6165 the relevant information, including package dependencies. For maximum
6166 efficiency, it is recommended to install the @command{unzip} utility, so
6167 that the importer can unzip Python wheels and gather data from them.
6169 The command below imports metadata for the @code{itsdangerous} Python
6173 guix import pypi itsdangerous
6178 Import metadata from @uref{https://rubygems.org/,
6179 RubyGems}@footnote{This functionality requires Guile-JSON to be
6180 installed. @xref{Requirements}.}. Information is taken from the
6181 JSON-formatted description available at @code{rubygems.org} and includes
6182 most relevant information, including runtime dependencies. There are
6183 some caveats, however. The metadata doesn't distinguish between
6184 synopses and descriptions, so the same string is used for both fields.
6185 Additionally, the details of non-Ruby dependencies required to build
6186 native extensions is unavailable and left as an exercise to the
6189 The command below imports metadata for the @code{rails} Ruby package:
6192 guix import gem rails
6197 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}@footnote{This
6198 functionality requires Guile-JSON to be installed.
6199 @xref{Requirements}.}.
6200 Information is taken from the JSON-formatted metadata provided through
6201 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
6202 relevant information, such as module dependencies. License information
6203 should be checked closely. If Perl is available in the store, then the
6204 @code{corelist} utility will be used to filter core modules out of the
6205 list of dependencies.
6207 The command command below imports metadata for the @code{Acme::Boolean}
6211 guix import cpan Acme::Boolean
6216 @cindex Bioconductor
6217 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
6218 central repository for the @uref{http://r-project.org, GNU@tie{}R
6219 statistical and graphical environment}.
6221 Information is extracted from the @code{DESCRIPTION} file of the package.
6223 The command command below imports metadata for the @code{Cairo}
6227 guix import cran Cairo
6230 When @code{--recursive} is added, the importer will traverse the
6231 dependency graph of the given upstream package recursively and generate
6232 package expressions for all those packages that are not yet in Guix.
6234 When @code{--archive=bioconductor} is added, metadata is imported from
6235 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
6236 packages for for the analysis and comprehension of high-throughput
6237 genomic data in bioinformatics.
6239 Information is extracted from the @code{DESCRIPTION} file of a package
6240 published on the web interface of the Bioconductor SVN repository.
6242 The command below imports metadata for the @code{GenomicRanges}
6246 guix import cran --archive=bioconductor GenomicRanges
6252 Import metadata from @uref{http://www.ctan.org/, CTAN}, the
6253 comprehensive TeX archive network for TeX packages that are part of the
6254 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
6256 Information about the package is obtained through the XML API provided
6257 by CTAN, while the source code is downloaded from the SVN repository of
6258 the Tex Live project. This is done because the CTAN does not keep
6261 The command command below imports metadata for the @code{fontspec}
6265 guix import texlive fontspec
6268 When @code{--archive=DIRECTORY} is added, the source code is downloaded
6269 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
6270 tree in the TeX Live SVN repository, but from the specified sibling
6271 directory under the same root.
6273 The command below imports metadata for the @code{ifxetex} package from
6274 CTAN while fetching the sources from the directory
6275 @file{texmf/source/generic}:
6278 guix import texlive --archive=generic ifxetex
6282 @cindex JSON, import
6283 Import package metadata from a local JSON file@footnote{This
6284 functionality requires Guile-JSON to be installed.
6285 @xref{Requirements}.}. Consider the following example package
6286 definition in JSON format:
6292 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
6293 "build-system": "gnu",
6294 "home-page": "https://www.gnu.org/software/hello/",
6295 "synopsis": "Hello, GNU world: An example GNU package",
6296 "description": "GNU Hello prints a greeting.",
6297 "license": "GPL-3.0+",
6298 "native-inputs": ["gcc@@6"]
6302 The field names are the same as for the @code{<package>} record
6303 (@xref{Defining Packages}). References to other packages are provided
6304 as JSON lists of quoted package specification strings such as
6305 @code{guile} or @code{guile@@2.0}.
6307 The importer also supports a more explicit source definition using the
6308 common fields for @code{<origin>} records:
6314 "method": "url-fetch",
6315 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
6317 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
6324 The command below reads metadata from the JSON file @code{hello.json}
6325 and outputs a package expression:
6328 guix import json hello.json
6332 Import metadata from a local copy of the source of the
6333 @uref{http://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
6334 relies on the @command{nix-instantiate} command of
6335 @uref{http://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
6336 typically written in a mixture of Nix-language and Bash code. This
6337 command only imports the high-level package structure that is written in
6338 the Nix language. It normally includes all the basic fields of a
6341 When importing a GNU package, the synopsis and descriptions are replaced
6342 by their canonical upstream variant.
6344 Usually, you will first need to do:
6347 export NIX_REMOTE=daemon
6351 so that @command{nix-instantiate} does not try to open the Nix database.
6353 As an example, the command below imports the package definition of
6354 LibreOffice (more precisely, it imports the definition of the package
6355 bound to the @code{libreoffice} top-level attribute):
6358 guix import nix ~/path/to/nixpkgs libreoffice
6363 Import metadata from the Haskell community's central package archive
6364 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
6365 Cabal files and includes all the relevant information, including package
6368 Specific command-line options are:
6373 Read a Cabal file from standard input.
6374 @item --no-test-dependencies
6376 Do not include dependencies required only by the test suites.
6377 @item --cabal-environment=@var{alist}
6378 @itemx -e @var{alist}
6379 @var{alist} is a Scheme alist defining the environment in which the
6380 Cabal conditionals are evaluated. The accepted keys are: @code{os},
6381 @code{arch}, @code{impl} and a string representing the name of a flag.
6382 The value associated with a flag has to be either the symbol
6383 @code{true} or @code{false}. The value associated with other keys
6384 has to conform to the Cabal file format definition. The default value
6385 associated with the keys @code{os}, @code{arch} and @code{impl} is
6386 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
6389 The command below imports metadata for the latest version of the
6390 @code{HTTP} Haskell package without including test dependencies and
6391 specifying the value of the flag @samp{network-uri} as @code{false}:
6394 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
6397 A specific package version may optionally be specified by following the
6398 package name by an at-sign and a version number as in the following example:
6401 guix import hackage mtl@@2.1.3.1
6406 The @code{stackage} importer is a wrapper around the @code{hackage} one.
6407 It takes a package name, looks up the package version included in a
6408 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
6409 release and uses the @code{hackage} importer to retrieve its metadata.
6410 Note that it is up to you to select an LTS release compatible with the
6411 GHC compiler used by Guix.
6413 Specific command-line options are:
6416 @item --no-test-dependencies
6418 Do not include dependencies required only by the test suites.
6419 @item --lts-version=@var{version}
6420 @itemx -r @var{version}
6421 @var{version} is the desired LTS release version. If omitted the latest
6425 The command below imports metadata for the @code{HTTP} Haskell package
6426 included in the LTS Stackage release version 7.18:
6429 guix import stackage --lts-version=7.18 HTTP
6434 Import metadata from an Emacs Lisp Package Archive (ELPA) package
6435 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6437 Specific command-line options are:
6440 @item --archive=@var{repo}
6441 @itemx -a @var{repo}
6442 @var{repo} identifies the archive repository from which to retrieve the
6443 information. Currently the supported repositories and their identifiers
6447 @uref{http://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
6448 identifier. This is the default.
6450 Packages from @code{elpa.gnu.org} are signed with one of the keys
6451 contained in the GnuPG keyring at
6452 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
6453 @code{emacs} package (@pxref{Package Installation, ELPA package
6454 signatures,, emacs, The GNU Emacs Manual}).
6457 @uref{http://stable.melpa.org/packages, MELPA-Stable}, selected by the
6458 @code{melpa-stable} identifier.
6461 @uref{http://melpa.org/packages, MELPA}, selected by the @code{melpa}
6468 Import metadata from the crates.io Rust package repository
6469 @uref{https://crates.io, crates.io}.
6472 The structure of the @command{guix import} code is modular. It would be
6473 useful to have more importers for other package formats, and your help
6474 is welcome here (@pxref{Contributing}).
6476 @node Invoking guix refresh
6477 @section Invoking @command{guix refresh}
6479 @cindex @command {guix refresh}
6480 The primary audience of the @command{guix refresh} command is developers
6481 of the GNU software distribution. By default, it reports any packages
6482 provided by the distribution that are outdated compared to the latest
6483 upstream version, like this:
6487 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
6488 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
6491 Alternately, one can specify packages to consider, in which case a
6492 warning is emitted for packages that lack an updater:
6495 $ guix refresh coreutils guile guile-ssh
6496 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
6497 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
6500 @command{guix refresh} browses the upstream repository of each package and determines
6501 the highest version number of the releases therein. The command
6502 knows how to update specific types of packages: GNU packages, ELPA
6503 packages, etc.---see the documentation for @option{--type} below. There
6504 are many packages, though, for which it lacks a method to determine
6505 whether a new upstream release is available. However, the mechanism is
6506 extensible, so feel free to get in touch with us to add a new method!
6508 Sometimes the upstream name differs from the package name used in Guix,
6509 and @command{guix refresh} needs a little help. Most updaters honor the
6510 @code{upstream-name} property in package definitions, which can be used
6514 (define-public network-manager
6516 (name "network-manager")
6518 (properties '((upstream-name . "NetworkManager")))))
6521 When passed @code{--update}, it modifies distribution source files to
6522 update the version numbers and source tarball hashes of those package
6523 recipes (@pxref{Defining Packages}). This is achieved by downloading
6524 each package's latest source tarball and its associated OpenPGP
6525 signature, authenticating the downloaded tarball against its signature
6526 using @command{gpg}, and finally computing its hash. When the public
6527 key used to sign the tarball is missing from the user's keyring, an
6528 attempt is made to automatically retrieve it from a public key server;
6529 when this is successful, the key is added to the user's keyring; otherwise,
6530 @command{guix refresh} reports an error.
6532 The following options are supported:
6536 @item --expression=@var{expr}
6537 @itemx -e @var{expr}
6538 Consider the package @var{expr} evaluates to.
6540 This is useful to precisely refer to a package, as in this example:
6543 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
6546 This command lists the dependents of the ``final'' libc (essentially all
6551 Update distribution source files (package recipes) in place. This is
6552 usually run from a checkout of the Guix source tree (@pxref{Running
6553 Guix Before It Is Installed}):
6556 $ ./pre-inst-env guix refresh -s non-core -u
6559 @xref{Defining Packages}, for more information on package definitions.
6561 @item --select=[@var{subset}]
6562 @itemx -s @var{subset}
6563 Select all the packages in @var{subset}, one of @code{core} or
6566 The @code{core} subset refers to all the packages at the core of the
6567 distribution---i.e., packages that are used to build ``everything
6568 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
6569 changing one of these packages in the distribution entails a rebuild of
6570 all the others. Thus, such updates are an inconvenience to users in
6571 terms of build time or bandwidth used to achieve the upgrade.
6573 The @code{non-core} subset refers to the remaining packages. It is
6574 typically useful in cases where an update of the core packages would be
6577 @item --manifest=@var{file}
6578 @itemx -m @var{file}
6579 Select all the packages from the manifest in @var{file}. This is useful to
6580 check if any packages of the user manifest can be updated.
6582 @item --type=@var{updater}
6583 @itemx -t @var{updater}
6584 Select only packages handled by @var{updater} (may be a comma-separated
6585 list of updaters). Currently, @var{updater} may be one of:
6589 the updater for GNU packages;
6591 the updater for GNOME packages;
6593 the updater for KDE packages;
6595 the updater for X.org packages;
6597 the updater for packages hosted on kernel.org;
6599 the updater for @uref{http://elpa.gnu.org/, ELPA} packages;
6601 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
6603 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
6605 the updater for @uref{http://www.cpan.org/, CPAN} packages;
6607 the updater for @uref{https://pypi.python.org, PyPI} packages.
6609 the updater for @uref{https://rubygems.org, RubyGems} packages.
6611 the updater for @uref{https://github.com, GitHub} packages.
6613 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
6615 the updater for @uref{https://www.stackage.org, Stackage} packages.
6617 the updater for @uref{https://crates.io, Crates} packages.
6620 For instance, the following command only checks for updates of Emacs
6621 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
6624 $ guix refresh --type=elpa,cran
6625 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
6626 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
6631 In addition, @command{guix refresh} can be passed one or more package
6632 names, as in this example:
6635 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
6639 The command above specifically updates the @code{emacs} and
6640 @code{idutils} packages. The @code{--select} option would have no
6641 effect in this case.
6643 When considering whether to upgrade a package, it is sometimes
6644 convenient to know which packages would be affected by the upgrade and
6645 should be checked for compatibility. For this the following option may
6646 be used when passing @command{guix refresh} one or more package names:
6650 @item --list-updaters
6652 List available updaters and exit (see @option{--type} above.)
6654 For each updater, display the fraction of packages it covers; at the
6655 end, display the fraction of packages covered by all these updaters.
6657 @item --list-dependent
6659 List top-level dependent packages that would need to be rebuilt as a
6660 result of upgrading one or more packages.
6662 @xref{Invoking guix graph, the @code{reverse-package} type of
6663 @command{guix graph}}, for information on how to visualize the list of
6664 dependents of a package.
6668 Be aware that the @code{--list-dependent} option only
6669 @emph{approximates} the rebuilds that would be required as a result of
6670 an upgrade. More rebuilds might be required under some circumstances.
6673 $ guix refresh --list-dependent flex
6674 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
6675 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
6678 The command above lists a set of packages that could be built to check
6679 for compatibility with an upgraded @code{flex} package.
6681 The following options can be used to customize GnuPG operation:
6685 @item --gpg=@var{command}
6686 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
6687 for in @code{$PATH}.
6689 @item --key-download=@var{policy}
6690 Handle missing OpenPGP keys according to @var{policy}, which may be one
6695 Always download missing OpenPGP keys from the key server, and add them
6696 to the user's GnuPG keyring.
6699 Never try to download missing OpenPGP keys. Instead just bail out.
6702 When a package signed with an unknown OpenPGP key is encountered, ask
6703 the user whether to download it or not. This is the default behavior.
6706 @item --key-server=@var{host}
6707 Use @var{host} as the OpenPGP key server when importing a public key.
6711 The @code{github} updater uses the
6712 @uref{https://developer.github.com/v3/, GitHub API} to query for new
6713 releases. When used repeatedly e.g. when refreshing all packages,
6714 GitHub will eventually refuse to answer any further API requests. By
6715 default 60 API requests per hour are allowed, and a full refresh on all
6716 GitHub packages in Guix requires more than this. Authentication with
6717 GitHub through the use of an API token alleviates these limits. To use
6718 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
6719 token procured from @uref{https://github.com/settings/tokens} or
6723 @node Invoking guix lint
6724 @section Invoking @command{guix lint}
6726 @cindex @command{guix lint}
6727 @cindex package, checking for errors
6728 The @command{guix lint} command is meant to help package developers avoid
6729 common errors and use a consistent style. It runs a number of checks on
6730 a given set of packages in order to find common mistakes in their
6731 definitions. Available @dfn{checkers} include (see
6732 @code{--list-checkers} for a complete list):
6737 Validate certain typographical and stylistic rules about package
6738 descriptions and synopses.
6740 @item inputs-should-be-native
6741 Identify inputs that should most likely be native inputs.
6746 @itemx source-file-name
6747 Probe @code{home-page} and @code{source} URLs and report those that are
6748 invalid. Suggest a @code{mirror://} URL when applicable. Check that
6749 the source file name is meaningful, e.g. is not
6750 just a version number or ``git-checkout'', without a declared
6751 @code{file-name} (@pxref{origin Reference}).
6754 @cindex security vulnerabilities
6755 @cindex CVE, Common Vulnerabilities and Exposures
6756 Report known vulnerabilities found in the Common Vulnerabilities and
6757 Exposures (CVE) databases of the current and past year
6758 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
6761 To view information about a particular vulnerability, visit pages such as:
6765 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
6767 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
6771 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
6772 @code{CVE-2015-7554}.
6774 Package developers can specify in package recipes the
6775 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
6776 name and version of the package when they differ from the name that Guix
6777 uses, as in this example:
6783 ;; CPE calls this package "grub2".
6784 (properties '((cpe-name . "grub2"))))
6788 Warn about obvious source code formatting issues: trailing white space,
6789 use of tabulations, etc.
6792 The general syntax is:
6795 guix lint @var{options} @var{package}@dots{}
6798 If no package is given on the command line, then all packages are checked.
6799 The @var{options} may be zero or more of the following:
6802 @item --list-checkers
6804 List and describe all the available checkers that will be run on packages
6809 Only enable the checkers specified in a comma-separated list using the
6810 names returned by @code{--list-checkers}.
6814 @node Invoking guix size
6815 @section Invoking @command{guix size}
6818 @cindex package size
6820 @cindex @command{guix size}
6821 The @command{guix size} command helps package developers profile the
6822 disk usage of packages. It is easy to overlook the impact of an
6823 additional dependency added to a package, or the impact of using a
6824 single output for a package that could easily be split (@pxref{Packages
6825 with Multiple Outputs}). Such are the typical issues that
6826 @command{guix size} can highlight.
6828 The command can be passed a package specification such as @code{gcc@@4.8}
6829 or @code{guile:debug}, or a file name in the store. Consider this
6833 $ guix size coreutils
6834 store item total self
6835 /gnu/store/@dots{}-coreutils-8.23 70.0 13.9 19.8%
6836 /gnu/store/@dots{}-gmp-6.0.0a 55.3 2.5 3.6%
6837 /gnu/store/@dots{}-acl-2.2.52 53.7 0.5 0.7%
6838 /gnu/store/@dots{}-attr-2.4.46 53.2 0.3 0.5%
6839 /gnu/store/@dots{}-gcc-4.8.4-lib 52.9 15.7 22.4%
6840 /gnu/store/@dots{}-glibc-2.21 37.2 37.2 53.1%
6844 The store items listed here constitute the @dfn{transitive closure} of
6845 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
6846 would be returned by:
6849 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
6852 Here the output shows three columns next to store items. The first column,
6853 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
6854 the store item---that is, its own size plus the size of all its
6855 dependencies. The next column, labeled ``self'', shows the size of the
6856 item itself. The last column shows the ratio of the size of the item
6857 itself to the space occupied by all the items listed here.
6859 In this example, we see that the closure of Coreutils weighs in at
6860 70@tie{}MiB, half of which is taken by libc. (That libc represents a
6861 large fraction of the closure is not a problem @i{per se} because it is
6862 always available on the system anyway.)
6864 When the package passed to @command{guix size} is available in the
6865 store, @command{guix size} queries the daemon to determine its
6866 dependencies, and measures its size in the store, similar to @command{du
6867 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
6870 When the given package is @emph{not} in the store, @command{guix size}
6871 reports information based on the available substitutes
6872 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
6873 store items that are not even on disk, only available remotely.
6875 You can also specify several package names:
6878 $ guix size coreutils grep sed bash
6879 store item total self
6880 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
6881 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
6882 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
6883 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
6889 In this example we see that the combination of the four packages takes
6890 102.3@tie{}MiB in total, which is much less than the sum of each closure
6891 since they have a lot of dependencies in common.
6893 The available options are:
6897 @item --substitute-urls=@var{urls}
6898 Use substitute information from @var{urls}.
6899 @xref{client-substitute-urls, the same option for @code{guix build}}.
6901 @item --sort=@var{key}
6902 Sort lines according to @var{key}, one of the following options:
6906 the size of each item (the default);
6908 the total size of the item's closure.
6911 @item --map-file=@var{file}
6912 Write a graphical map of disk usage in PNG format to @var{file}.
6914 For the example above, the map looks like this:
6916 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
6917 produced by @command{guix size}}
6919 This option requires that
6920 @uref{http://wingolog.org/software/guile-charting/, Guile-Charting} be
6921 installed and visible in Guile's module search path. When that is not
6922 the case, @command{guix size} fails as it tries to load it.
6924 @item --system=@var{system}
6925 @itemx -s @var{system}
6926 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
6930 @node Invoking guix graph
6931 @section Invoking @command{guix graph}
6934 @cindex @command{guix graph}
6935 @cindex package dependencies
6936 Packages and their dependencies form a @dfn{graph}, specifically a
6937 directed acyclic graph (DAG). It can quickly become difficult to have a
6938 mental model of the package DAG, so the @command{guix graph} command
6939 provides a visual representation of the DAG. By default,
6940 @command{guix graph} emits a DAG representation in the input format of
6941 @uref{http://www.graphviz.org/, Graphviz}, so its output can be passed
6942 directly to the @command{dot} command of Graphviz. It can also emit an
6943 HTML page with embedded JavaScript code to display a ``chord diagram''
6944 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
6945 emit Cypher queries to construct a graph in a graph database supporting
6946 the @uref{http://www.opencypher.org/, openCypher} query language.
6947 The general syntax is:
6950 guix graph @var{options} @var{package}@dots{}
6953 For example, the following command generates a PDF file representing the
6954 package DAG for the GNU@tie{}Core Utilities, showing its build-time
6958 guix graph coreutils | dot -Tpdf > dag.pdf
6961 The output looks like this:
6963 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
6965 Nice little graph, no?
6967 But there is more than one graph! The one above is concise: it is the
6968 graph of package objects, omitting implicit inputs such as GCC, libc,
6969 grep, etc. It is often useful to have such a concise graph, but
6970 sometimes one may want to see more details. @command{guix graph} supports
6971 several types of graphs, allowing you to choose the level of detail:
6975 This is the default type used in the example above. It shows the DAG of
6976 package objects, excluding implicit dependencies. It is concise, but
6977 filters out many details.
6979 @item reverse-package
6980 This shows the @emph{reverse} DAG of packages. For example:
6983 guix graph --type=reverse-package ocaml
6986 ... yields the graph of packages that depend on OCaml.
6988 Note that for core packages this can yield huge graphs. If all you want
6989 is to know the number of packages that depend on a given package, use
6990 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
6991 @option{--list-dependent}}).
6994 This is the package DAG, @emph{including} implicit inputs.
6996 For instance, the following command:
6999 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
7002 ... yields this bigger graph:
7004 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
7006 At the bottom of the graph, we see all the implicit inputs of
7007 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
7009 Now, note that the dependencies of these implicit inputs---that is, the
7010 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
7011 here, for conciseness.
7014 Similar to @code{bag-emerged}, but this time including all the bootstrap
7017 @item bag-with-origins
7018 Similar to @code{bag}, but also showing origins and their dependencies.
7021 This is the most detailed representation: It shows the DAG of
7022 derivations (@pxref{Derivations}) and plain store items. Compared to
7023 the above representation, many additional nodes are visible, including
7024 build scripts, patches, Guile modules, etc.
7026 For this type of graph, it is also possible to pass a @file{.drv} file
7027 name instead of a package name, as in:
7030 guix graph -t derivation `guix system build -d my-config.scm`
7034 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
7035 For example, the following command shows the graph for the package
7036 module that defines the @code{guile} package:
7039 guix graph -t module guile | dot -Tpdf > module-graph.pdf
7043 All the types above correspond to @emph{build-time dependencies}. The
7044 following graph type represents the @emph{run-time dependencies}:
7048 This is the graph of @dfn{references} of a package output, as returned
7049 by @command{guix gc --references} (@pxref{Invoking guix gc}).
7051 If the given package output is not available in the store, @command{guix
7052 graph} attempts to obtain dependency information from substitutes.
7054 Here you can also pass a store file name instead of a package name. For
7055 example, the command below produces the reference graph of your profile
7056 (which can be big!):
7059 guix graph -t references `readlink -f ~/.guix-profile`
7063 This is the graph of the @dfn{referrers} of a store item, as returned by
7064 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
7066 This relies exclusively on local information from your store. For
7067 instance, let us suppose that the current Inkscape is available in 10
7068 profiles on your machine; @command{guix graph -t referrers inkscape}
7069 will show a graph rooted at Inkscape and with those 10 profiles linked
7072 It can help determine what is preventing a store item from being garbage
7077 The available options are the following:
7080 @item --type=@var{type}
7081 @itemx -t @var{type}
7082 Produce a graph output of @var{type}, where @var{type} must be one of
7083 the values listed above.
7086 List the supported graph types.
7088 @item --backend=@var{backend}
7089 @itemx -b @var{backend}
7090 Produce a graph using the selected @var{backend}.
7092 @item --list-backends
7093 List the supported graph backends.
7095 Currently, the available backends are Graphviz and d3.js.
7097 @item --expression=@var{expr}
7098 @itemx -e @var{expr}
7099 Consider the package @var{expr} evaluates to.
7101 This is useful to precisely refer to a package, as in this example:
7104 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
7109 @node Invoking guix environment
7110 @section Invoking @command{guix environment}
7112 @cindex reproducible build environments
7113 @cindex development environments
7114 @cindex @command{guix environment}
7115 @cindex environment, package build environment
7116 The purpose of @command{guix environment} is to assist hackers in
7117 creating reproducible development environments without polluting their
7118 package profile. The @command{guix environment} tool takes one or more
7119 packages, builds all of their inputs, and creates a shell
7120 environment to use them.
7122 The general syntax is:
7125 guix environment @var{options} @var{package}@dots{}
7128 The following example spawns a new shell set up for the development of
7132 guix environment guile
7135 If the needed dependencies are not built yet, @command{guix environment}
7136 automatically builds them. The environment of the new shell is an augmented
7137 version of the environment that @command{guix environment} was run in.
7138 It contains the necessary search paths for building the given package
7139 added to the existing environment variables. To create a ``pure''
7140 environment, in which the original environment variables have been unset,
7141 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
7142 environment variables such as @code{PATH} in their @file{~/.bashrc}
7143 file. As a consequence, when @code{guix environment} launches it, Bash
7144 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
7145 environment variables. It is an error to define such environment
7146 variables in @file{.bashrc}; instead, they should be defined in
7147 @file{.bash_profile}, which is sourced only by log-in shells.
7148 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
7149 details on Bash start-up files.}.
7151 @vindex GUIX_ENVIRONMENT
7152 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
7153 variable in the shell it spawns; its value is the file name of the
7154 profile of this environment. This allows users to, say, define a
7155 specific prompt for development environments in their @file{.bashrc}
7156 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
7159 if [ -n "$GUIX_ENVIRONMENT" ]
7161 export PS1="\u@@\h \w [dev]\$ "
7166 ... or to browse the profile:
7169 $ ls "$GUIX_ENVIRONMENT/bin"
7172 Additionally, more than one package may be specified, in which case the
7173 union of the inputs for the given packages are used. For example, the
7174 command below spawns a shell where all of the dependencies of both Guile
7175 and Emacs are available:
7178 guix environment guile emacs
7181 Sometimes an interactive shell session is not desired. An arbitrary
7182 command may be invoked by placing the @code{--} token to separate the
7183 command from the rest of the arguments:
7186 guix environment guile -- make -j4
7189 In other situations, it is more convenient to specify the list of
7190 packages needed in the environment. For example, the following command
7191 runs @command{python} from an environment containing Python@tie{}2.7 and
7195 guix environment --ad-hoc python2-numpy python-2.7 -- python
7198 Furthermore, one might want the dependencies of a package and also some
7199 additional packages that are not build-time or runtime dependencies, but
7200 are useful when developing nonetheless. Because of this, the
7201 @code{--ad-hoc} flag is positional. Packages appearing before
7202 @code{--ad-hoc} are interpreted as packages whose dependencies will be
7203 added to the environment. Packages appearing after are interpreted as
7204 packages that will be added to the environment directly. For example,
7205 the following command creates a Guix development environment that
7206 additionally includes Git and strace:
7209 guix environment guix --ad-hoc git strace
7212 Sometimes it is desirable to isolate the environment as much as
7213 possible, for maximal purity and reproducibility. In particular, when
7214 using Guix on a host distro that is not GuixSD, it is desirable to
7215 prevent access to @file{/usr/bin} and other system-wide resources from
7216 the development environment. For example, the following command spawns
7217 a Guile REPL in a ``container'' where only the store and the current
7218 working directory are mounted:
7221 guix environment --ad-hoc --container guile -- guile
7225 The @code{--container} option requires Linux-libre 3.19 or newer.
7228 The available options are summarized below.
7231 @item --root=@var{file}
7232 @itemx -r @var{file}
7233 @cindex persistent environment
7234 @cindex garbage collector root, for environments
7235 Make @var{file} a symlink to the profile for this environment, and
7236 register it as a garbage collector root.
7238 This is useful if you want to protect your environment from garbage
7239 collection, to make it ``persistent''.
7241 When this option is omitted, the environment is protected from garbage
7242 collection only for the duration of the @command{guix environment}
7243 session. This means that next time you recreate the same environment,
7244 you could have to rebuild or re-download packages. @xref{Invoking guix
7245 gc}, for more on GC roots.
7247 @item --expression=@var{expr}
7248 @itemx -e @var{expr}
7249 Create an environment for the package or list of packages that
7250 @var{expr} evaluates to.
7252 For example, running:
7255 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
7258 starts a shell with the environment for this specific variant of the
7264 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
7267 starts a shell with all the GuixSD base packages available.
7269 The above commands only use the default output of the given packages.
7270 To select other outputs, two element tuples can be specified:
7273 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
7276 @item --load=@var{file}
7277 @itemx -l @var{file}
7278 Create an environment for the package or list of packages that the code
7279 within @var{file} evaluates to.
7281 As an example, @var{file} might contain a definition like this
7282 (@pxref{Defining Packages}):
7285 @verbatiminclude environment-gdb.scm
7288 @item --manifest=@var{file}
7289 @itemx -m @var{file}
7290 Create an environment for the packages contained in the manifest object
7291 returned by the Scheme code in @var{file}.
7293 This is similar to the same-named option in @command{guix package}
7294 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
7298 Include all specified packages in the resulting environment, as if an
7299 @i{ad hoc} package were defined with them as inputs. This option is
7300 useful for quickly creating an environment without having to write a
7301 package expression to contain the desired inputs.
7303 For instance, the command:
7306 guix environment --ad-hoc guile guile-sdl -- guile
7309 runs @command{guile} in an environment where Guile and Guile-SDL are
7312 Note that this example implicitly asks for the default output of
7313 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
7314 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
7315 of @code{glib} (@pxref{Packages with Multiple Outputs}).
7317 This option may be composed with the default behavior of @command{guix
7318 environment}. Packages appearing before @code{--ad-hoc} are interpreted
7319 as packages whose dependencies will be added to the environment, the
7320 default behavior. Packages appearing after are interpreted as packages
7321 that will be added to the environment directly.
7324 Unset existing environment variables when building the new environment.
7325 This has the effect of creating an environment in which search paths
7326 only contain package inputs.
7328 @item --search-paths
7329 Display the environment variable definitions that make up the
7332 @item --system=@var{system}
7333 @itemx -s @var{system}
7334 Attempt to build for @var{system}---e.g., @code{i686-linux}.
7339 Run @var{command} within an isolated container. The current working
7340 directory outside the container is mapped inside the container.
7341 Additionally, unless overridden with @code{--user}, a dummy home
7342 directory is created that matches the current user's home directory, and
7343 @file{/etc/passwd} is configured accordingly. The spawned process runs
7344 as the current user outside the container, but has root privileges in
7345 the context of the container.
7349 For containers, share the network namespace with the host system.
7350 Containers created without this flag only have access to the loopback
7353 @item --link-profile
7355 For containers, link the environment profile to
7356 @file{~/.guix-profile} within the container. This is equivalent to
7357 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
7358 within the container. Linking will fail and abort the environment if
7359 the directory already exists, which will certainly be the case if
7360 @command{guix environment} was invoked in the user's home directory.
7362 Certain packages are configured to look in
7363 @code{~/.guix-profile} for configuration files and data;@footnote{For
7364 example, the @code{fontconfig} package inspects
7365 @file{~/.guix-profile/share/fonts} for additional fonts.}
7366 @code{--link-profile} allows these programs to behave as expected within
7369 @item --user=@var{user}
7370 @itemx -u @var{user}
7371 For containers, use the username @var{user} in place of the current
7372 user. The generated @file{/etc/passwd} entry within the container will
7373 contain the name @var{user}; the home directory will be
7374 @file{/home/USER}; and no user GECOS data will be copied. @var{user}
7375 need not exist on the system.
7377 Additionally, any shared or exposed path (see @code{--share} and
7378 @code{--expose} respectively) whose target is within the current user's
7379 home directory will be remapped relative to @file{/home/USER}; this
7380 includes the automatic mapping of the current working directory.
7383 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
7385 guix environment --container --user=foo \
7386 --expose=$HOME/test \
7387 --expose=/tmp/target=$HOME/target
7390 While this will limit the leaking of user identity through home paths
7391 and each of the user fields, this is only one useful component of a
7392 broader privacy/anonymity solution---not one in and of itself.
7394 @item --expose=@var{source}[=@var{target}]
7395 For containers, expose the file system @var{source} from the host system
7396 as the read-only file system @var{target} within the container. If
7397 @var{target} is not specified, @var{source} is used as the target mount
7398 point in the container.
7400 The example below spawns a Guile REPL in a container in which the user's
7401 home directory is accessible read-only via the @file{/exchange}
7405 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
7408 @item --share=@var{source}[=@var{target}]
7409 For containers, share the file system @var{source} from the host system
7410 as the writable file system @var{target} within the container. If
7411 @var{target} is not specified, @var{source} is used as the target mount
7412 point in the container.
7414 The example below spawns a Guile REPL in a container in which the user's
7415 home directory is accessible for both reading and writing via the
7416 @file{/exchange} directory:
7419 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
7423 @command{guix environment}
7424 also supports all of the common build options that @command{guix
7425 build} supports (@pxref{Common Build Options}).
7428 @node Invoking guix publish
7429 @section Invoking @command{guix publish}
7431 @cindex @command{guix publish}
7432 The purpose of @command{guix publish} is to enable users to easily share
7433 their store with others, who can then use it as a substitute server
7434 (@pxref{Substitutes}).
7436 When @command{guix publish} runs, it spawns an HTTP server which allows
7437 anyone with network access to obtain substitutes from it. This means
7438 that any machine running Guix can also act as if it were a build farm,
7439 since the HTTP interface is compatible with Hydra, the software behind
7440 the @code{hydra.gnu.org} build farm.
7442 For security, each substitute is signed, allowing recipients to check
7443 their authenticity and integrity (@pxref{Substitutes}). Because
7444 @command{guix publish} uses the signing key of the system, which is only
7445 readable by the system administrator, it must be started as root; the
7446 @code{--user} option makes it drop root privileges early on.
7448 The signing key pair must be generated before @command{guix publish} is
7449 launched, using @command{guix archive --generate-key} (@pxref{Invoking
7452 The general syntax is:
7455 guix publish @var{options}@dots{}
7458 Running @command{guix publish} without any additional arguments will
7459 spawn an HTTP server on port 8080:
7465 Once a publishing server has been authorized (@pxref{Invoking guix
7466 archive}), the daemon may download substitutes from it:
7469 guix-daemon --substitute-urls=http://example.org:8080
7472 By default, @command{guix publish} compresses archives on the fly as it
7473 serves them. This ``on-the-fly'' mode is convenient in that it requires
7474 no setup and is immediately available. However, when serving lots of
7475 clients, we recommend using the @option{--cache} option, which enables
7476 caching of the archives before they are sent to clients---see below for
7477 details. The @command{guix weather} command provides a handy way to
7478 check what a server provides (@pxref{Invoking guix weather}).
7480 As a bonus, @command{guix publish} also serves as a content-addressed
7481 mirror for source files referenced in @code{origin} records
7482 (@pxref{origin Reference}). For instance, assuming @command{guix
7483 publish} is running on @code{example.org}, the following URL returns the
7484 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
7485 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
7488 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
7491 Obviously, these URLs only work for files that are in the store; in
7492 other cases, they return 404 (``Not Found'').
7494 @cindex build logs, publication
7495 Build logs are available from @code{/log} URLs like:
7498 http://example.org/log/gwspk@dots{}-guile-2.2.3
7502 When @command{guix-daemon} is configured to save compressed build logs,
7503 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
7504 URLs return the compressed log as-is, with an appropriate
7505 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
7506 running @command{guix-daemon} with @code{--log-compression=gzip} since
7507 Web browsers can automatically decompress it, which is not the case with
7510 The following options are available:
7513 @item --port=@var{port}
7514 @itemx -p @var{port}
7515 Listen for HTTP requests on @var{port}.
7517 @item --listen=@var{host}
7518 Listen on the network interface for @var{host}. The default is to
7519 accept connections from any interface.
7521 @item --user=@var{user}
7522 @itemx -u @var{user}
7523 Change privileges to @var{user} as soon as possible---i.e., once the
7524 server socket is open and the signing key has been read.
7526 @item --compression[=@var{level}]
7527 @itemx -C [@var{level}]
7528 Compress data using the given @var{level}. When @var{level} is zero,
7529 disable compression. The range 1 to 9 corresponds to different gzip
7530 compression levels: 1 is the fastest, and 9 is the best (CPU-intensive).
7533 Unless @option{--cache} is used, compression occurs on the fly and
7534 the compressed streams are not
7535 cached. Thus, to reduce load on the machine that runs @command{guix
7536 publish}, it may be a good idea to choose a low compression level, to
7537 run @command{guix publish} behind a caching proxy, or to use
7538 @option{--cache}. Using @option{--cache} has the advantage that it
7539 allows @command{guix publish} to add @code{Content-Length} HTTP header
7542 @item --cache=@var{directory}
7543 @itemx -c @var{directory}
7544 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
7545 and only serve archives that are in cache.
7547 When this option is omitted, archives and meta-data are created
7548 on-the-fly. This can reduce the available bandwidth, especially when
7549 compression is enabled, since this may become CPU-bound. Another
7550 drawback of the default mode is that the length of archives is not known
7551 in advance, so @command{guix publish} does not add a
7552 @code{Content-Length} HTTP header to its responses, which in turn
7553 prevents clients from knowing the amount of data being downloaded.
7555 Conversely, when @option{--cache} is used, the first request for a store
7556 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
7557 background process to @dfn{bake} the archive---computing its
7558 @code{.narinfo} and compressing the archive, if needed. Once the
7559 archive is cached in @var{directory}, subsequent requests succeed and
7560 are served directly from the cache, which guarantees that clients get
7561 the best possible bandwidth.
7563 The ``baking'' process is performed by worker threads. By default, one
7564 thread per CPU core is created, but this can be customized. See
7565 @option{--workers} below.
7567 When @option{--ttl} is used, cached entries are automatically deleted
7568 when they have expired.
7570 @item --workers=@var{N}
7571 When @option{--cache} is used, request the allocation of @var{N} worker
7572 threads to ``bake'' archives.
7574 @item --ttl=@var{ttl}
7575 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
7576 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
7577 days, @code{1m} means 1 month, and so on.
7579 This allows the user's Guix to keep substitute information in cache for
7580 @var{ttl}. However, note that @code{guix publish} does not itself
7581 guarantee that the store items it provides will indeed remain available
7582 for as long as @var{ttl}.
7584 Additionally, when @option{--cache} is used, cached entries that have
7585 not been accessed for @var{ttl} and that no longer have a corresponding
7586 item in the store, may be deleted.
7588 @item --nar-path=@var{path}
7589 Use @var{path} as the prefix for the URLs of ``nar'' files
7590 (@pxref{Invoking guix archive, normalized archives}).
7592 By default, nars are served at a URL such as
7593 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
7594 change the @code{/nar} part to @var{path}.
7596 @item --public-key=@var{file}
7597 @itemx --private-key=@var{file}
7598 Use the specific @var{file}s as the public/private key pair used to sign
7599 the store items being published.
7601 The files must correspond to the same key pair (the private key is used
7602 for signing and the public key is merely advertised in the signature
7603 metadata). They must contain keys in the canonical s-expression format
7604 as produced by @command{guix archive --generate-key} (@pxref{Invoking
7605 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
7606 @file{/etc/guix/signing-key.sec} are used.
7608 @item --repl[=@var{port}]
7609 @itemx -r [@var{port}]
7610 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
7611 Reference Manual}) on @var{port} (37146 by default). This is used
7612 primarily for debugging a running @command{guix publish} server.
7615 Enabling @command{guix publish} on a GuixSD system is a one-liner: just
7616 instantiate a @code{guix-publish-service-type} service in the @code{services} field
7617 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
7618 @code{guix-publish-service-type}}).
7620 If you are instead running Guix on a ``foreign distro'', follow these
7625 If your host distro uses the systemd init system:
7628 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
7629 /etc/systemd/system/
7630 # systemctl start guix-publish && systemctl enable guix-publish
7634 If your host distro uses the Upstart init system:
7637 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
7638 # start guix-publish
7642 Otherwise, proceed similarly with your distro's init system.
7645 @node Invoking guix challenge
7646 @section Invoking @command{guix challenge}
7648 @cindex reproducible builds
7649 @cindex verifiable builds
7650 @cindex @command{guix challenge}
7652 Do the binaries provided by this server really correspond to the source
7653 code it claims to build? Is a package build process deterministic?
7654 These are the questions the @command{guix challenge} command attempts to
7657 The former is obviously an important question: Before using a substitute
7658 server (@pxref{Substitutes}), one had better @emph{verify} that it
7659 provides the right binaries, and thus @emph{challenge} it. The latter
7660 is what enables the former: If package builds are deterministic, then
7661 independent builds of the package should yield the exact same result,
7662 bit for bit; if a server provides a binary different from the one
7663 obtained locally, it may be either corrupt or malicious.
7665 We know that the hash that shows up in @file{/gnu/store} file names is
7666 the hash of all the inputs of the process that built the file or
7667 directory---compilers, libraries, build scripts,
7668 etc. (@pxref{Introduction}). Assuming deterministic build processes,
7669 one store file name should map to exactly one build output.
7670 @command{guix challenge} checks whether there is, indeed, a single
7671 mapping by comparing the build outputs of several independent builds of
7672 any given store item.
7674 The command output looks like this:
7677 $ guix challenge --substitute-urls="https://hydra.gnu.org https://guix.example.org"
7678 updating list of substitutes from 'https://hydra.gnu.org'... 100.0%
7679 updating list of substitutes from 'https://guix.example.org'... 100.0%
7680 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
7681 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
7682 https://hydra.gnu.org/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
7683 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
7684 /gnu/store/@dots{}-git-2.5.0 contents differ:
7685 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
7686 https://hydra.gnu.org/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
7687 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
7688 /gnu/store/@dots{}-pius-2.1.1 contents differ:
7689 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
7690 https://hydra.gnu.org/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
7691 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
7695 6,406 store items were analyzed:
7696 - 4,749 (74.1%) were identical
7697 - 525 (8.2%) differed
7698 - 1,132 (17.7%) were inconclusive
7702 In this example, @command{guix challenge} first scans the store to
7703 determine the set of locally-built derivations---as opposed to store
7704 items that were downloaded from a substitute server---and then queries
7705 all the substitute servers. It then reports those store items for which
7706 the servers obtained a result different from the local build.
7708 @cindex non-determinism, in package builds
7709 As an example, @code{guix.example.org} always gets a different answer.
7710 Conversely, @code{hydra.gnu.org} agrees with local builds, except in the
7711 case of Git. This might indicate that the build process of Git is
7712 non-deterministic, meaning that its output varies as a function of
7713 various things that Guix does not fully control, in spite of building
7714 packages in isolated environments (@pxref{Features}). Most common
7715 sources of non-determinism include the addition of timestamps in build
7716 results, the inclusion of random numbers, and directory listings sorted
7717 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
7720 To find out what is wrong with this Git binary, we can do something along
7721 these lines (@pxref{Invoking guix archive}):
7724 $ wget -q -O - https://hydra.gnu.org/nar/@dots{}-git-2.5.0 \
7725 | guix archive -x /tmp/git
7726 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
7729 This command shows the difference between the files resulting from the
7730 local build, and the files resulting from the build on
7731 @code{hydra.gnu.org} (@pxref{Overview, Comparing and Merging Files,,
7732 diffutils, Comparing and Merging Files}). The @command{diff} command
7733 works great for text files. When binary files differ, a better option
7734 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
7735 visualize differences for all kinds of files.
7737 Once you have done that work, you can tell whether the differences are due
7738 to a non-deterministic build process or to a malicious server. We try
7739 hard to remove sources of non-determinism in packages to make it easier
7740 to verify substitutes, but of course, this is a process that
7741 involves not just Guix, but a large part of the free software community.
7742 In the meantime, @command{guix challenge} is one tool to help address
7745 If you are writing packages for Guix, you are encouraged to check
7746 whether @code{hydra.gnu.org} and other substitute servers obtain the
7747 same build result as you did with:
7750 $ guix challenge @var{package}
7754 where @var{package} is a package specification such as
7755 @code{guile@@2.0} or @code{glibc:debug}.
7757 The general syntax is:
7760 guix challenge @var{options} [@var{packages}@dots{}]
7763 When a difference is found between the hash of a locally-built item and
7764 that of a server-provided substitute, or among substitutes provided by
7765 different servers, the command displays it as in the example above and
7766 its exit code is 2 (other non-zero exit codes denote other kinds of
7769 The one option that matters is:
7773 @item --substitute-urls=@var{urls}
7774 Consider @var{urls} the whitespace-separated list of substitute source
7779 Show details about matches (identical contents) in addition to
7780 information about mismatches.
7784 @node Invoking guix copy
7785 @section Invoking @command{guix copy}
7787 @cindex copy, of store items, over SSH
7788 @cindex SSH, copy of store items
7789 @cindex sharing store items across machines
7790 @cindex transferring store items across machines
7791 The @command{guix copy} command copies items from the store of one
7792 machine to that of another machine over a secure shell (SSH)
7793 connection@footnote{This command is available only when Guile-SSH was
7794 found. @xref{Requirements}, for details.}. For example, the following
7795 command copies the @code{coreutils} package, the user's profile, and all
7796 their dependencies over to @var{host}, logged in as @var{user}:
7799 guix copy --to=@var{user}@@@var{host} \
7800 coreutils `readlink -f ~/.guix-profile`
7803 If some of the items to be copied are already present on @var{host},
7804 they are not actually sent.
7806 The command below retrieves @code{libreoffice} and @code{gimp} from
7807 @var{host}, assuming they are available there:
7810 guix copy --from=@var{host} libreoffice gimp
7813 The SSH connection is established using the Guile-SSH client, which is
7814 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
7815 @file{~/.ssh/config}, and uses the SSH agent for authentication.
7817 The key used to sign items that are sent must be accepted by the remote
7818 machine. Likewise, the key used by the remote machine to sign items you
7819 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
7820 own daemon. @xref{Invoking guix archive}, for more information about
7821 store item authentication.
7823 The general syntax is:
7826 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
7829 You must always specify one of the following options:
7832 @item --to=@var{spec}
7833 @itemx --from=@var{spec}
7834 Specify the host to send to or receive from. @var{spec} must be an SSH
7835 spec such as @code{example.org}, @code{charlie@@example.org}, or
7836 @code{charlie@@example.org:2222}.
7839 The @var{items} can be either package names, such as @code{gimp}, or
7840 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
7842 When specifying the name of a package to send, it is first built if
7843 needed, unless @option{--dry-run} was specified. Common build options
7844 are supported (@pxref{Common Build Options}).
7847 @node Invoking guix container
7848 @section Invoking @command{guix container}
7850 @cindex @command{guix container}
7852 As of version @value{VERSION}, this tool is experimental. The interface
7853 is subject to radical change in the future.
7856 The purpose of @command{guix container} is to manipulate processes
7857 running within an isolated environment, commonly known as a
7858 ``container'', typically created by the @command{guix environment}
7859 (@pxref{Invoking guix environment}) and @command{guix system container}
7860 (@pxref{Invoking guix system}) commands.
7862 The general syntax is:
7865 guix container @var{action} @var{options}@dots{}
7868 @var{action} specifies the operation to perform with a container, and
7869 @var{options} specifies the context-specific arguments for the action.
7871 The following actions are available:
7875 Execute a command within the context of a running container.
7880 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
7883 @var{pid} specifies the process ID of the running container.
7884 @var{program} specifies an executable file name within the root file
7885 system of the container. @var{arguments} are the additional options that
7886 will be passed to @var{program}.
7888 The following command launches an interactive login shell inside a
7889 GuixSD container, started by @command{guix system container}, and whose
7893 guix container exec 9001 /run/current-system/profile/bin/bash --login
7896 Note that the @var{pid} cannot be the parent process of a container. It
7897 must be PID 1 of the container or one of its child processes.
7901 @node Invoking guix weather
7902 @section Invoking @command{guix weather}
7904 Occasionally you're grumpy because substitutes are lacking and you end
7905 up building packages by yourself (@pxref{Substitutes}). The
7906 @command{guix weather} command reports on substitute availability on the
7907 specified servers so you can have an idea of whether you'll be grumpy
7908 today. It can sometimes be useful info as a user, but it is primarily
7909 useful to people running @command{guix publish} (@pxref{Invoking guix
7912 @cindex statistics, for substitutes
7913 @cindex availability of substitutes
7914 @cindex substitute availability
7915 @cindex weather, substitute availability
7916 Here's a sample run:
7919 $ guix weather --substitute-urls=https://guix.example.org
7920 computing 5,872 package derivations for x86_64-linux...
7921 looking for 6,128 store items on https://guix.example.org..
7922 updating list of substitutes from 'https://guix.example.org'... 100.0%
7923 https://guix.example.org
7924 43.4% substitutes available (2,658 out of 6,128)
7925 7,032.5 MiB of nars (compressed)
7926 19,824.2 MiB on disk (uncompressed)
7927 0.030 seconds per request (182.9 seconds in total)
7928 33.5 requests per second
7930 9.8% (342 out of 3,470) of the missing items are queued
7932 x86_64-linux: 518 (59.7%)
7933 i686-linux: 221 (25.5%)
7934 aarch64-linux: 128 (14.8%)
7935 build rate: 23.41 builds per hour
7936 x86_64-linux: 11.16 builds per hour
7937 i686-linux: 6.03 builds per hour
7938 aarch64-linux: 6.41 builds per hour
7941 @cindex continuous integration, statistics
7942 As you can see, it reports the fraction of all the packages for which
7943 substitutes are available on the server---regardless of whether
7944 substitutes are enabled, and regardless of whether this server's signing
7945 key is authorized. It also reports the size of the compressed archives
7946 (``nars'') provided by the server, the size the corresponding store
7947 items occupy in the store (assuming deduplication is turned off), and
7948 the server's throughput. The second part gives continuous integration
7949 (CI) statistics, if the server supports it.
7951 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
7952 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
7953 challenge}, it ignores signatures on those substitutes, which is
7954 innocuous since the command only gathers statistics and cannot install
7957 Among other things, it is possible to query specific system types and
7958 specific package sets. The available options are listed below.
7961 @item --substitute-urls=@var{urls}
7962 @var{urls} is the space-separated list of substitute server URLs to
7963 query. When this option is omitted, the default set of substitute
7966 @item --system=@var{system}
7967 @itemx -s @var{system}
7968 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
7969 option can be repeated, in which case @command{guix weather} will query
7970 substitutes for several system types.
7972 @item --manifest=@var{file}
7973 Instead of querying substitutes for all the packages, only ask for those
7974 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
7975 with the @code{-m} option of @command{guix package} (@pxref{Invoking
7980 @c *********************************************************************
7981 @node GNU Distribution
7982 @chapter GNU Distribution
7984 @cindex Guix System Distribution
7986 Guix comes with a distribution of the GNU system consisting entirely of
7987 free software@footnote{The term ``free'' here refers to the
7988 @url{http://www.gnu.org/philosophy/free-sw.html,freedom provided to
7989 users of that software}.}. The
7990 distribution can be installed on its own (@pxref{System Installation}),
7991 but it is also possible to install Guix as a package manager on top of
7992 an installed GNU/Linux system (@pxref{Installation}). To distinguish
7993 between the two, we refer to the standalone distribution as the Guix
7994 System Distribution, or GuixSD.
7996 The distribution provides core GNU packages such as GNU libc, GCC, and
7997 Binutils, as well as many GNU and non-GNU applications. The complete
7998 list of available packages can be browsed
7999 @url{http://www.gnu.org/software/guix/packages,on-line} or by
8000 running @command{guix package} (@pxref{Invoking guix package}):
8003 guix package --list-available
8006 Our goal is to provide a practical 100% free software distribution of
8007 Linux-based and other variants of GNU, with a focus on the promotion and
8008 tight integration of GNU components, and an emphasis on programs and
8009 tools that help users exert that freedom.
8011 Packages are currently available on the following platforms:
8016 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
8019 Intel 32-bit architecture (IA32), Linux-Libre kernel;
8022 ARMv7-A architecture with hard float, Thumb-2 and NEON,
8023 using the EABI hard-float application binary interface (ABI),
8024 and Linux-Libre kernel.
8027 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel. This is
8028 currently in an experimental stage, with limited support.
8029 @xref{Contributing}, for how to help!
8031 @item mips64el-linux
8032 little-endian 64-bit MIPS processors, specifically the Loongson series,
8033 n32 ABI, and Linux-Libre kernel.
8037 GuixSD itself is currently only available on @code{i686} and @code{x86_64}.
8040 For information on porting to other architectures or kernels,
8044 * System Installation:: Installing the whole operating system.
8045 * System Configuration:: Configuring the operating system.
8046 * Documentation:: Browsing software user manuals.
8047 * Installing Debugging Files:: Feeding the debugger.
8048 * Security Updates:: Deploying security fixes quickly.
8049 * Package Modules:: Packages from the programmer's viewpoint.
8050 * Packaging Guidelines:: Growing the distribution.
8051 * Bootstrapping:: GNU/Linux built from scratch.
8052 * Porting:: Targeting another platform or kernel.
8055 Building this distribution is a cooperative effort, and you are invited
8056 to join! @xref{Contributing}, for information about how you can help.
8058 @node System Installation
8059 @section System Installation
8061 @cindex installing GuixSD
8062 @cindex Guix System Distribution
8063 This section explains how to install the Guix System Distribution (GuixSD)
8064 on a machine. The Guix package manager can
8065 also be installed on top of a running GNU/Linux system,
8066 @pxref{Installation}.
8070 @c This paragraph is for people reading this from tty2 of the
8071 @c installation image.
8072 You are reading this documentation with an Info reader. For details on
8073 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
8074 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
8075 Info}. Hit @kbd{l} afterwards to come back here.
8077 Alternately, run @command{info info} in another tty to keep the manual
8083 * Limitations:: What you can expect.
8084 * Hardware Considerations:: Supported hardware.
8085 * USB Stick and DVD Installation:: Preparing the installation medium.
8086 * Preparing for Installation:: Networking, partitioning, etc.
8087 * Proceeding with the Installation:: The real thing.
8088 * Installing GuixSD in a VM:: GuixSD playground.
8089 * Building the Installation Image:: How this comes to be.
8093 @subsection Limitations
8095 As of version @value{VERSION}, the Guix System Distribution (GuixSD) is
8096 not production-ready. It may contain bugs and lack important
8097 features. Thus, if you are looking for a stable production system that
8098 respects your freedom as a computer user, a good solution at this point
8099 is to consider @url{http://www.gnu.org/distros/free-distros.html, one of
8100 the more established GNU/Linux distributions}. We hope you can soon switch
8101 to the GuixSD without fear, of course. In the meantime, you can
8102 also keep using your distribution and try out the package manager on top
8103 of it (@pxref{Installation}).
8105 Before you proceed with the installation, be aware of the following
8106 noteworthy limitations applicable to version @value{VERSION}:
8110 The installation process does not include a graphical user interface and
8111 requires familiarity with GNU/Linux (see the following subsections to
8112 get a feel of what that means.)
8115 Support for the Logical Volume Manager (LVM) is missing.
8118 More and more system services are provided (@pxref{Services}), but some
8122 More than 6,500 packages are available, but you might
8123 occasionally find that a useful package is missing.
8126 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
8127 as well as a number of X11 window managers. However, some graphical
8128 applications may be missing, as well as KDE.
8131 You have been warned! But more than a disclaimer, this is an invitation
8132 to report issues (and success stories!), and to join us in improving it.
8133 @xref{Contributing}, for more info.
8136 @node Hardware Considerations
8137 @subsection Hardware Considerations
8139 @cindex hardware support on GuixSD
8140 GNU@tie{}GuixSD focuses on respecting the user's computing freedom. It
8141 builds around the kernel Linux-libre, which means that only hardware for
8142 which free software drivers and firmware exist is supported. Nowadays,
8143 a wide range of off-the-shelf hardware is supported on
8144 GNU/Linux-libre---from keyboards to graphics cards to scanners and
8145 Ethernet controllers. Unfortunately, there are still areas where
8146 hardware vendors deny users control over their own computing, and such
8147 hardware is not supported on GuixSD.
8149 @cindex WiFi, hardware support
8150 One of the main areas where free drivers or firmware are lacking is WiFi
8151 devices. WiFi devices known to work include those using Atheros chips
8152 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
8153 driver, and those using Broadcom/AirForce chips (BCM43xx with
8154 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
8155 Linux-libre driver. Free firmware exists for both and is available
8156 out-of-the-box on GuixSD, as part of @var{%base-firmware}
8157 (@pxref{operating-system Reference, @code{firmware}}).
8159 @cindex RYF, Respects Your Freedom
8160 The @uref{https://www.fsf.org/, Free Software Foundation} runs
8161 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
8162 certification program for hardware products that respect your freedom
8163 and your privacy and ensure that you have control over your device. We
8164 encourage you to check the list of RYF-certified devices.
8166 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
8167 web site. It contains a catalog of hardware devices with information
8168 about their support in GNU/Linux.
8171 @node USB Stick and DVD Installation
8172 @subsection USB Stick and DVD Installation
8174 An ISO-9660 installation image that can be written to a USB stick or
8175 burnt to a DVD can be downloaded from
8176 @indicateurl{ftp://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.iso.xz},
8177 where @var{system} is one of:
8181 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
8184 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
8187 @c start duplication of authentication part from ``Binary Installation''
8188 Make sure to download the associated @file{.sig} file and to verify the
8189 authenticity of the image against it, along these lines:
8192 $ wget ftp://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.iso.xz.sig
8193 $ gpg --verify guixsd-install-@value{VERSION}.@var{system}.iso.xz.sig
8196 If that command fails because you do not have the required public key,
8197 then run this command to import it:
8200 $ gpg --keyserver pgp.mit.edu --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
8204 and rerun the @code{gpg --verify} command.
8207 This image contains the tools necessary for an installation.
8208 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
8210 @unnumberedsubsubsec Copying to a USB Stick
8212 To copy the image to a USB stick, follow these steps:
8216 Decompress the image using the @command{xz} command:
8219 xz -d guixsd-install-@value{VERSION}.@var{system}.iso.xz
8223 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
8224 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
8225 copy the image with:
8228 dd if=guixsd-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX
8232 Access to @file{/dev/sdX} usually requires root privileges.
8235 @unnumberedsubsubsec Burning on a DVD
8237 To copy the image to a DVD, follow these steps:
8241 Decompress the image using the @command{xz} command:
8244 xz -d guixsd-install-@value{VERSION}.@var{system}.iso.xz
8248 Insert a blank DVD into your machine, and determine
8249 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
8250 copy the image with:
8253 growisofs -dvd-compat -Z /dev/srX=guixsd-install-@value{VERSION}.x86_64.iso
8256 Access to @file{/dev/srX} usually requires root privileges.
8259 @unnumberedsubsubsec Booting
8261 Once this is done, you should be able to reboot the system and boot from
8262 the USB stick or DVD. The latter usually requires you to get in the
8263 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
8265 @xref{Installing GuixSD in a VM}, if, instead, you would like to install
8266 GuixSD in a virtual machine (VM).
8269 @node Preparing for Installation
8270 @subsection Preparing for Installation
8272 Once you have successfully booted your computer using the installation medium,
8273 you should end up with a root prompt. Several console TTYs are configured
8274 and can be used to run commands as root. TTY2 shows this documentation,
8275 browsable using the Info reader commands (@pxref{Top,,, info-stnd,
8276 Stand-alone GNU Info}). The installation system runs the GPM mouse
8277 daemon, which allows you to select text with the left mouse button and
8278 to paste it with the middle button.
8281 Installation requires access to the Internet so that any missing
8282 dependencies of your system configuration can be downloaded. See the
8283 ``Networking'' section below.
8286 The installation system includes many common tools needed for this task.
8287 But it is also a full-blown GuixSD system, which means that you can
8288 install additional packages, should you need it, using @command{guix
8289 package} (@pxref{Invoking guix package}).
8291 @subsubsection Keyboard Layout
8293 @cindex keyboard layout
8294 The installation image uses the US qwerty keyboard layout. If you want
8295 to change it, you can use the @command{loadkeys} command. For example,
8296 the following command selects the Dvorak keyboard layout:
8302 See the files under @file{/run/current-system/profile/share/keymaps} for
8303 a list of available keyboard layouts. Run @command{man loadkeys} for
8306 @subsubsection Networking
8308 Run the following command see what your network interfaces are called:
8315 @dots{} or, using the GNU/Linux-specific @command{ip} command:
8321 @c http://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
8322 Wired interfaces have a name starting with @samp{e}; for example, the
8323 interface corresponding to the first on-board Ethernet controller is
8324 called @samp{eno1}. Wireless interfaces have a name starting with
8325 @samp{w}, like @samp{w1p2s0}.
8328 @item Wired connection
8329 To configure a wired network run the following command, substituting
8330 @var{interface} with the name of the wired interface you want to use.
8333 ifconfig @var{interface} up
8336 @item Wireless connection
8339 To configure wireless networking, you can create a configuration file
8340 for the @command{wpa_supplicant} configuration tool (its location is not
8341 important) using one of the available text editors such as
8345 nano wpa_supplicant.conf
8348 As an example, the following stanza can go to this file and will work
8349 for many wireless networks, provided you give the actual SSID and
8350 passphrase for the network you are connecting to:
8354 ssid="@var{my-ssid}"
8356 psk="the network's secret passphrase"
8360 Start the wireless service and run it in the background with the
8361 following command (substitute @var{interface} with the name of the
8362 network interface you want to use):
8365 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
8368 Run @command{man wpa_supplicant} for more information.
8372 At this point, you need to acquire an IP address. On a network where IP
8373 addresses are automatically assigned @i{via} DHCP, you can run:
8376 dhclient -v @var{interface}
8379 Try to ping a server to see if networking is up and running:
8385 Setting up network access is almost always a requirement because the
8386 image does not contain all the software and tools that may be needed.
8388 @cindex installing over SSH
8389 If you want to, you can continue the installation remotely by starting
8393 herd start ssh-daemon
8396 Make sure to either set a password with @command{passwd}, or configure
8397 OpenSSH public key authentication before logging in.
8399 @subsubsection Disk Partitioning
8401 Unless this has already been done, the next step is to partition, and
8402 then format the target partition(s).
8404 The installation image includes several partitioning tools, including
8405 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
8406 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
8407 the partition layout you want:
8413 If your disk uses the GUID Partition Table (GPT) format and you plan to
8414 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
8415 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
8418 @cindex EFI, installation
8419 @cindex UEFI, installation
8420 @cindex ESP, EFI system partition
8421 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
8422 (ESP) is required. This partition should be mounted at @file{/boot/efi} and
8423 must have the @code{esp} flag set. E.g., for @command{parted}:
8426 parted /dev/sda set 1 esp on
8429 Once you are done partitioning the target hard disk drive, you have to
8430 create a file system on the relevant partition(s)@footnote{Currently
8431 GuixSD only supports ext4 and btrfs file systems. In particular, code
8432 that reads file system UUIDs and labels only works for these file system
8433 types.}. For the ESP, if you have one and assuming it is
8434 @file{/dev/sda2}, run:
8437 mkfs.fat -F32 /dev/sda2
8440 Preferably, assign file systems a label so that you can easily and
8441 reliably refer to them in @code{file-system} declarations (@pxref{File
8442 Systems}). This is typically done using the @code{-L} option of
8443 @command{mkfs.ext4} and related commands. So, assuming the target root
8444 partition lives at @file{/dev/sda1}, a file system with the label
8445 @code{my-root} can be created with:
8448 mkfs.ext4 -L my-root /dev/sda1
8451 @cindex encrypted disk
8452 If you are instead planning to encrypt the root partition, you can use
8453 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
8454 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
8455 @code{man cryptsetup}} for more information.) Assuming you want to
8456 store the root partition on @file{/dev/sda1}, the command sequence would
8457 be along these lines:
8460 cryptsetup luksFormat /dev/sda1
8461 cryptsetup open --type luks /dev/sda1 my-partition
8462 mkfs.ext4 -L my-root /dev/mapper/my-partition
8465 Once that is done, mount the target file system under @file{/mnt}
8466 with a command like (again, assuming @code{my-root} is the label of the
8470 mount LABEL=my-root /mnt
8473 Also mount any other file systems you would like to use on the target
8474 system relative to this path. If you have @file{/boot} on a separate
8475 partition for example, mount it at @file{/mnt/boot} now so it is found
8476 by @code{guix system init} afterwards.
8478 Finally, if you plan to use one or more swap partitions (@pxref{Memory
8479 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
8480 sure to initialize them with @command{mkswap}. Assuming you have one
8481 swap partition on @file{/dev/sda2}, you would run:
8488 Alternatively, you may use a swap file. For example, assuming that in
8489 the new system you want to use the file @file{/swapfile} as a swap file,
8490 you would run@footnote{This example will work for many types of file
8491 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
8492 btrfs), the required steps may be different. For details, see the
8493 manual pages for @command{mkswap} and @command{swapon}.}:
8496 # This is 10 GiB of swap space. Adjust "count" to change the size.
8497 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
8498 # For security, make the file readable and writable only by root.
8499 chmod 600 /mnt/swapfile
8500 mkswap /mnt/swapfile
8501 swapon /mnt/swapfile
8504 Note that if you have encrypted the root partition and created a swap
8505 file in its file system as described above, then the encryption also
8506 protects the swap file, just like any other file in that file system.
8508 @node Proceeding with the Installation
8509 @subsection Proceeding with the Installation
8511 With the target partitions ready and the target root mounted on
8512 @file{/mnt}, we're ready to go. First, run:
8515 herd start cow-store /mnt
8518 This makes @file{/gnu/store} copy-on-write, such that packages added to it
8519 during the installation phase are written to the target disk on @file{/mnt}
8520 rather than kept in memory. This is necessary because the first phase of
8521 the @command{guix system init} command (see below) entails downloads or
8522 builds to @file{/gnu/store} which, initially, is an in-memory file system.
8524 Next, you have to edit a file and
8525 provide the declaration of the operating system to be installed. To
8526 that end, the installation system comes with three text editors. We
8527 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
8528 supports syntax highlighting and parentheses matching; other editors
8529 include GNU Zile (an Emacs clone), and
8530 nvi (a clone of the original BSD @command{vi} editor).
8531 We strongly recommend storing that file on the target root file system, say,
8532 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
8533 configuration file once you have rebooted into the newly-installed system.
8535 @xref{Using the Configuration System}, for an overview of the
8536 configuration file. The example configurations discussed in that
8537 section are available under @file{/etc/configuration} in the
8538 installation image. Thus, to get started with a system configuration
8539 providing a graphical display server (a ``desktop'' system), you can run
8540 something along these lines:
8544 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
8545 # nano /mnt/etc/config.scm
8548 You should pay attention to what your configuration file contains, and
8553 Make sure the @code{bootloader-configuration} form refers to the target
8554 you want to install GRUB on. It should mention @code{grub-bootloader} if
8555 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
8556 for newer UEFI systems. For legacy systems, the @code{target} field
8557 names a device, like @code{/dev/sda}; for UEFI systems it names a path
8558 to a mounted EFI partition, like @code{/boot/efi}, and do make sure the
8559 path is actually mounted.
8562 Be sure that your file system labels match the value of their respective
8563 @code{device} fields in your @code{file-system} configuration, assuming
8564 your @code{file-system} configuration sets the value of @code{title} to
8568 If there are encrypted or RAID partitions, make sure to add a
8569 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
8572 Once you are done preparing the configuration file, the new system must
8573 be initialized (remember that the target root file system is mounted
8577 guix system init /mnt/etc/config.scm /mnt
8581 This copies all the necessary files and installs GRUB on
8582 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
8583 more information, @pxref{Invoking guix system}. This command may trigger
8584 downloads or builds of missing packages, which can take some time.
8586 Once that command has completed---and hopefully succeeded!---you can run
8587 @command{reboot} and boot into the new system. The @code{root} password
8588 in the new system is initially empty; other users' passwords need to be
8589 initialized by running the @command{passwd} command as @code{root},
8590 unless your configuration specifies otherwise
8591 (@pxref{user-account-password, user account passwords}).
8593 @cindex upgrading GuixSD
8594 From then on, you can update GuixSD whenever you want by running
8595 @command{guix pull} as @code{root} (@pxref{Invoking guix pull}), and
8596 then running @command{guix system reconfigure} to build a new system
8597 generation with the latest packages and services (@pxref{Invoking guix
8598 system}). We recommend doing that regularly so that your system
8599 includes the latest security updates (@pxref{Security Updates}).
8601 Join us on @code{#guix} on the Freenode IRC network or on
8602 @file{guix-devel@@gnu.org} to share your experience---good or not so
8605 @node Installing GuixSD in a VM
8606 @subsection Installing GuixSD in a Virtual Machine
8608 @cindex virtual machine, GuixSD installation
8609 @cindex virtual private server (VPS)
8610 @cindex VPS (virtual private server)
8611 If you'd like to install GuixSD in a virtual machine (VM) or on a
8612 virtual private server (VPS) rather than on your beloved machine, this
8615 To boot a @uref{http://qemu.org/,QEMU} VM for installing GuixSD in a
8616 disk image, follow these steps:
8620 First, retrieve and decompress the GuixSD installation image as
8621 described previously (@pxref{USB Stick and DVD Installation}).
8624 Create a disk image that will hold the installed system. To make a
8625 qcow2-formatted disk image, use the @command{qemu-img} command:
8628 qemu-img create -f qcow2 guixsd.img 50G
8631 The resulting file will be much smaller than 50 GB (typically less than
8632 1 MB), but it will grow as the virtualized storage device is filled up.
8635 Boot the USB installation image in an VM:
8638 qemu-system-x86_64 -m 1024 -smp 1 \
8639 -net user -net nic,model=virtio -boot menu=on \
8640 -drive file=guixsd-install-@value{VERSION}.@var{system}.iso \
8641 -drive file=guixsd.img
8644 The ordering of the drives matters.
8646 In the VM console, quickly press the @kbd{F12} key to enter the boot
8647 menu. Then press the @kbd{2} key and the @kbd{RET} key to validate your
8651 You're now root in the VM, proceed with the installation process.
8652 @xref{Preparing for Installation}, and follow the instructions.
8655 Once installation is complete, you can boot the system that's on your
8656 @file{guixsd.img} image. @xref{Running GuixSD in a VM}, for how to do
8659 @node Building the Installation Image
8660 @subsection Building the Installation Image
8662 @cindex installation image
8663 The installation image described above was built using the @command{guix
8664 system} command, specifically:
8667 guix system disk-image gnu/system/install.scm
8670 Have a look at @file{gnu/system/install.scm} in the source tree,
8671 and see also @ref{Invoking guix system} for more information
8672 about the installation image.
8674 @node System Configuration
8675 @section System Configuration
8677 @cindex system configuration
8678 The Guix System Distribution supports a consistent whole-system configuration
8679 mechanism. By that we mean that all aspects of the global system
8680 configuration---such as the available system services, timezone and
8681 locale settings, user accounts---are declared in a single place. Such
8682 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
8684 One of the advantages of putting all the system configuration under the
8685 control of Guix is that it supports transactional system upgrades, and
8686 makes it possible to roll back to a previous system instantiation,
8687 should something go wrong with the new one (@pxref{Features}). Another
8688 advantage is that it makes it easy to replicate the exact same configuration
8689 across different machines, or at different points in time, without
8690 having to resort to additional administration tools layered on top of
8691 the own tools of the system.
8692 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
8694 This section describes this mechanism. First we focus on the system
8695 administrator's viewpoint---explaining how the system is configured and
8696 instantiated. Then we show how this mechanism can be extended, for
8697 instance to support new system services.
8700 * Using the Configuration System:: Customizing your GNU system.
8701 * operating-system Reference:: Detail of operating-system declarations.
8702 * File Systems:: Configuring file system mounts.
8703 * Mapped Devices:: Block device extra processing.
8704 * User Accounts:: Specifying user accounts.
8705 * Locales:: Language and cultural convention settings.
8706 * Services:: Specifying system services.
8707 * Setuid Programs:: Programs running with root privileges.
8708 * X.509 Certificates:: Authenticating HTTPS servers.
8709 * Name Service Switch:: Configuring libc's name service switch.
8710 * Initial RAM Disk:: Linux-Libre bootstrapping.
8711 * Bootloader Configuration:: Configuring the boot loader.
8712 * Invoking guix system:: Instantiating a system configuration.
8713 * Running GuixSD in a VM:: How to run GuixSD in a virtual machine.
8714 * Defining Services:: Adding new service definitions.
8717 @node Using the Configuration System
8718 @subsection Using the Configuration System
8720 The operating system is configured by providing an
8721 @code{operating-system} declaration in a file that can then be passed to
8722 the @command{guix system} command (@pxref{Invoking guix system}). A
8723 simple setup, with the default system services, the default Linux-Libre
8724 kernel, initial RAM disk, and boot loader looks like this:
8726 @findex operating-system
8728 @include os-config-bare-bones.texi
8731 This example should be self-describing. Some of the fields defined
8732 above, such as @code{host-name} and @code{bootloader}, are mandatory.
8733 Others, such as @code{packages} and @code{services}, can be omitted, in
8734 which case they get a default value.
8736 Below we discuss the effect of some of the most important fields
8737 (@pxref{operating-system Reference}, for details about all the available
8738 fields), and how to @dfn{instantiate} the operating system using
8739 @command{guix system}.
8741 @unnumberedsubsubsec Globally-Visible Packages
8743 @vindex %base-packages
8744 The @code{packages} field lists packages that will be globally visible
8745 on the system, for all user accounts---i.e., in every user's @code{PATH}
8746 environment variable---in addition to the per-user profiles
8747 (@pxref{Invoking guix package}). The @var{%base-packages} variable
8748 provides all the tools one would expect for basic user and administrator
8749 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
8750 the GNU Zile lightweight text editor, @command{find}, @command{grep},
8751 etc. The example above adds GNU@tie{}Screen and OpenSSH to those,
8752 taken from the @code{(gnu packages screen)} and @code{(gnu packages ssh)}
8753 modules (@pxref{Package Modules}). The
8754 @code{(list package output)} syntax can be used to add a specific output
8758 (use-modules (gnu packages))
8759 (use-modules (gnu packages dns))
8763 (packages (cons (list bind "utils")
8767 @findex specification->package
8768 Referring to packages by variable name, like @code{bind} above, has
8769 the advantage of being unambiguous; it also allows typos and such to be
8770 diagnosed right away as ``unbound variables''. The downside is that one
8771 needs to know which module defines which package, and to augment the
8772 @code{use-package-modules} line accordingly. To avoid that, one can use
8773 the @code{specification->package} procedure of the @code{(gnu packages)}
8774 module, which returns the best package for a given name or name and
8778 (use-modules (gnu packages))
8782 (packages (append (map specification->package
8783 '("tcpdump" "htop" "gnupg@@2.0"))
8787 @unnumberedsubsubsec System Services
8790 @vindex %base-services
8791 The @code{services} field lists @dfn{system services} to be made
8792 available when the system starts (@pxref{Services}).
8793 The @code{operating-system} declaration above specifies that, in
8794 addition to the basic services, we want the @command{lshd} secure shell
8795 daemon listening on port 2222 (@pxref{Networking Services,
8796 @code{lsh-service}}). Under the hood,
8797 @code{lsh-service} arranges so that @code{lshd} is started with the
8798 right command-line options, possibly with supporting configuration files
8799 generated as needed (@pxref{Defining Services}).
8801 @cindex customization, of services
8802 @findex modify-services
8803 Occasionally, instead of using the base services as is, you will want to
8804 customize them. To do this, use @code{modify-services} (@pxref{Service
8805 Reference, @code{modify-services}}) to modify the list.
8807 For example, suppose you want to modify @code{guix-daemon} and Mingetty
8808 (the console log-in) in the @var{%base-services} list (@pxref{Base
8809 Services, @code{%base-services}}). To do that, you can write the
8810 following in your operating system declaration:
8813 (define %my-services
8814 ;; My very own list of services.
8815 (modify-services %base-services
8816 (guix-service-type config =>
8819 (use-substitutes? #f)
8820 (extra-options '("--gc-keep-derivations"))))
8821 (mingetty-service-type config =>
8822 (mingetty-configuration
8823 (inherit config)))))
8827 (services %my-services))
8830 This changes the configuration---i.e., the service parameters---of the
8831 @code{guix-service-type} instance, and that of all the
8832 @code{mingetty-service-type} instances in the @var{%base-services} list.
8833 Observe how this is accomplished: first, we arrange for the original
8834 configuration to be bound to the identifier @code{config} in the
8835 @var{body}, and then we write the @var{body} so that it evaluates to the
8836 desired configuration. In particular, notice how we use @code{inherit}
8837 to create a new configuration which has the same values as the old
8838 configuration, but with a few modifications.
8840 @cindex encrypted disk
8841 The configuration for a typical ``desktop'' usage, with an encrypted
8842 root partition, the X11 display
8843 server, GNOME and Xfce (users can choose which of these desktop
8844 environments to use at the log-in screen by pressing @kbd{F1}), network
8845 management, power management, and more, would look like this:
8848 @include os-config-desktop.texi
8852 A graphical UEFI system with a choice of lightweight window managers
8853 instead of full-blown desktop environments would look like this:
8856 @include os-config-lightweight-desktop.texi
8859 This example refers to the @file{/boot/efi} file system by its UUID,
8860 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
8861 as returned by the @command{blkid} command.
8863 @xref{Desktop Services}, for the exact list of services provided by
8864 @var{%desktop-services}. @xref{X.509 Certificates}, for background
8865 information about the @code{nss-certs} package that is used here.
8867 Again, @var{%desktop-services} is just a list of service objects. If
8868 you want to remove services from there, you can do so using the
8869 procedures for list filtering (@pxref{SRFI-1 Filtering and
8870 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
8871 following expression returns a list that contains all the services in
8872 @var{%desktop-services} minus the Avahi service:
8875 (remove (lambda (service)
8876 (eq? (service-kind service) avahi-service-type))
8880 @unnumberedsubsubsec Instantiating the System
8882 Assuming the @code{operating-system} declaration
8883 is stored in the @file{my-system-config.scm}
8884 file, the @command{guix system reconfigure my-system-config.scm} command
8885 instantiates that configuration, and makes it the default GRUB boot
8886 entry (@pxref{Invoking guix system}).
8888 The normal way to change the system configuration is by updating this
8889 file and re-running @command{guix system reconfigure}. One should never
8890 have to touch files in @file{/etc} or to run commands that modify the
8891 system state such as @command{useradd} or @command{grub-install}. In
8892 fact, you must avoid that since that would not only void your warranty
8893 but also prevent you from rolling back to previous versions of your
8894 system, should you ever need to.
8896 @cindex roll-back, of the operating system
8897 Speaking of roll-back, each time you run @command{guix system
8898 reconfigure}, a new @dfn{generation} of the system is created---without
8899 modifying or deleting previous generations. Old system generations get
8900 an entry in the bootloader boot menu, allowing you to boot them in case
8901 something went wrong with the latest generation. Reassuring, no? The
8902 @command{guix system list-generations} command lists the system
8903 generations available on disk. It is also possible to roll back the
8904 system via the commands @command{guix system roll-back} and
8905 @command{guix system switch-generation}.
8907 Although the command @command{guix system reconfigure} will not modify
8908 previous generations, must take care when the current generation is not
8909 the latest (e.g., after invoking @command{guix system roll-back}), since
8910 the operation might overwrite a later generation (@pxref{Invoking guix
8913 @unnumberedsubsubsec The Programming Interface
8915 At the Scheme level, the bulk of an @code{operating-system} declaration
8916 is instantiated with the following monadic procedure (@pxref{The Store
8919 @deffn {Monadic Procedure} operating-system-derivation os
8920 Return a derivation that builds @var{os}, an @code{operating-system}
8921 object (@pxref{Derivations}).
8923 The output of the derivation is a single directory that refers to all
8924 the packages, configuration files, and other supporting files needed to
8925 instantiate @var{os}.
8928 This procedure is provided by the @code{(gnu system)} module. Along
8929 with @code{(gnu services)} (@pxref{Services}), this module contains the
8930 guts of GuixSD. Make sure to visit it!
8933 @node operating-system Reference
8934 @subsection @code{operating-system} Reference
8936 This section summarizes all the options available in
8937 @code{operating-system} declarations (@pxref{Using the Configuration
8940 @deftp {Data Type} operating-system
8941 This is the data type representing an operating system configuration.
8942 By that, we mean all the global system configuration, not per-user
8943 configuration (@pxref{Using the Configuration System}).
8946 @item @code{kernel} (default: @var{linux-libre})
8947 The package object of the operating system kernel to use@footnote{Currently
8948 only the Linux-libre kernel is supported. In the future, it will be
8949 possible to use the GNU@tie{}Hurd.}.
8951 @item @code{kernel-arguments} (default: @code{'()})
8952 List of strings or gexps representing additional arguments to pass on
8953 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
8955 @item @code{bootloader}
8956 The system bootloader configuration object. @xref{Bootloader Configuration}.
8958 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
8960 @cindex initial RAM disk
8961 The list of Linux kernel modules that need to be available in the
8962 initial RAM disk. @xref{Initial RAM Disk}.
8964 @item @code{initrd} (default: @code{base-initrd})
8965 A monadic procedure that returns an initial RAM disk for the Linux
8966 kernel. This field is provided to support low-level customization and
8967 should rarely be needed for casual use. @xref{Initial RAM Disk}.
8969 @item @code{firmware} (default: @var{%base-firmware})
8971 List of firmware packages loadable by the operating system kernel.
8973 The default includes firmware needed for Atheros- and Broadcom-based
8974 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
8975 respectively). @xref{Hardware Considerations}, for more info on
8978 @item @code{host-name}
8981 @item @code{hosts-file}
8983 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
8984 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
8985 Reference Manual}). The default is a file with entries for
8986 @code{localhost} and @var{host-name}.
8988 @item @code{mapped-devices} (default: @code{'()})
8989 A list of mapped devices. @xref{Mapped Devices}.
8991 @item @code{file-systems}
8992 A list of file systems. @xref{File Systems}.
8994 @item @code{swap-devices} (default: @code{'()})
8995 @cindex swap devices
8996 A list of strings identifying devices or files to be used for ``swap
8997 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
8998 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
8999 It is possible to specify a swap file in a file system on a mapped
9000 device, provided that the necessary device mapping and file system are
9001 also specified. @xref{Mapped Devices} and @ref{File Systems}.
9003 @item @code{users} (default: @code{%base-user-accounts})
9004 @itemx @code{groups} (default: @var{%base-groups})
9005 List of user accounts and groups. @xref{User Accounts}.
9007 If the @code{users} list lacks a user account with UID@tie{}0, a
9008 ``root'' account with UID@tie{}0 is automatically added.
9010 @item @code{skeletons} (default: @code{(default-skeletons)})
9011 A list target file name/file-like object tuples (@pxref{G-Expressions,
9012 file-like objects}). These are the skeleton files that will be added to
9013 the home directory of newly-created user accounts.
9015 For instance, a valid value may look like this:
9018 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
9019 (".guile" ,(plain-file "guile"
9020 "(use-modules (ice-9 readline))
9021 (activate-readline)")))
9024 @item @code{issue} (default: @var{%default-issue})
9025 A string denoting the contents of the @file{/etc/issue} file, which is
9026 displayed when users log in on a text console.
9028 @item @code{packages} (default: @var{%base-packages})
9029 The set of packages installed in the global profile, which is accessible
9030 at @file{/run/current-system/profile}.
9032 The default set includes core utilities and it is good practice to
9033 install non-core utilities in user profiles (@pxref{Invoking guix
9036 @item @code{timezone}
9037 A timezone identifying string---e.g., @code{"Europe/Paris"}.
9039 You can run the @command{tzselect} command to find out which timezone
9040 string corresponds to your region. Choosing an invalid timezone name
9041 causes @command{guix system} to fail.
9043 @item @code{locale} (default: @code{"en_US.utf8"})
9044 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
9045 Library Reference Manual}). @xref{Locales}, for more information.
9047 @item @code{locale-definitions} (default: @var{%default-locale-definitions})
9048 The list of locale definitions to be compiled and that may be used at
9049 run time. @xref{Locales}.
9051 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
9052 The list of GNU@tie{}libc packages whose locale data and tools are used
9053 to build the locale definitions. @xref{Locales}, for compatibility
9054 considerations that justify this option.
9056 @item @code{name-service-switch} (default: @var{%default-nss})
9057 Configuration of the libc name service switch (NSS)---a
9058 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
9061 @item @code{services} (default: @var{%base-services})
9062 A list of service objects denoting system services. @xref{Services}.
9064 @item @code{pam-services} (default: @code{(base-pam-services)})
9066 @cindex pluggable authentication modules
9067 Linux @dfn{pluggable authentication module} (PAM) services.
9068 @c FIXME: Add xref to PAM services section.
9070 @item @code{setuid-programs} (default: @var{%setuid-programs})
9071 List of string-valued G-expressions denoting setuid programs.
9072 @xref{Setuid Programs}.
9074 @item @code{sudoers-file} (default: @var{%sudoers-specification})
9075 @cindex sudoers file
9076 The contents of the @file{/etc/sudoers} file as a file-like object
9077 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
9079 This file specifies which users can use the @command{sudo} command, what
9080 they are allowed to do, and what privileges they may gain. The default
9081 is that only @code{root} and members of the @code{wheel} group may use
9088 @subsection File Systems
9090 The list of file systems to be mounted is specified in the
9091 @code{file-systems} field of the operating system declaration
9092 (@pxref{Using the Configuration System}). Each file system is declared
9093 using the @code{file-system} form, like this:
9097 (mount-point "/home")
9098 (device "/dev/sda3")
9102 As usual, some of the fields are mandatory---those shown in the example
9103 above---while others can be omitted. These are described below.
9105 @deftp {Data Type} file-system
9106 Objects of this type represent file systems to be mounted. They
9107 contain the following members:
9111 This is a string specifying the type of the file system---e.g.,
9114 @item @code{mount-point}
9115 This designates the place where the file system is to be mounted.
9118 This names the ``source'' of the file system. By default it is the name
9119 of a node under @file{/dev}, but its meaning depends on the @code{title}
9120 field described below.
9122 @item @code{title} (default: @code{'device})
9123 This is a symbol that specifies how the @code{device} field is to be
9126 When it is the symbol @code{device}, then the @code{device} field is
9127 interpreted as a file name; when it is @code{label}, then @code{device}
9128 is interpreted as a file system label name; when it is @code{uuid},
9129 @code{device} is interpreted as a file system unique identifier (UUID).
9131 UUIDs may be converted from their string representation (as shown by the
9132 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
9133 @code{uuid} form expects 16-byte UUIDs as defined in
9134 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
9135 form of UUID used by the ext2 family of file systems and others, but it
9136 is different from ``UUIDs'' found in FAT file systems, for instance.},
9141 (mount-point "/home")
9144 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
9147 The @code{label} and @code{uuid} options offer a way to refer to file
9148 systems without having to hard-code their actual device
9149 name@footnote{Note that, while it is tempting to use
9150 @file{/dev/disk/by-uuid} and similar device names to achieve the same
9151 result, this is not recommended: These special device nodes are created
9152 by the udev daemon and may be unavailable at the time the device is
9155 However, when the source of a file system is a mapped device (@pxref{Mapped
9156 Devices}), its @code{device} field @emph{must} refer to the mapped
9157 device name---e.g., @file{/dev/mapper/root-partition}---and consequently
9158 @code{title} must be set to @code{'device}. This is required so that
9159 the system knows that mounting the file system depends on having the
9160 corresponding device mapping established.
9162 @item @code{flags} (default: @code{'()})
9163 This is a list of symbols denoting mount flags. Recognized flags
9164 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
9165 access to special files), @code{no-suid} (ignore setuid and setgid
9166 bits), and @code{no-exec} (disallow program execution.)
9168 @item @code{options} (default: @code{#f})
9169 This is either @code{#f}, or a string denoting mount options.
9171 @item @code{mount?} (default: @code{#t})
9172 This value indicates whether to automatically mount the file system when
9173 the system is brought up. When set to @code{#f}, the file system gets
9174 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
9175 is not automatically mounted.
9177 @item @code{needed-for-boot?} (default: @code{#f})
9178 This Boolean value indicates whether the file system is needed when
9179 booting. If that is true, then the file system is mounted when the
9180 initial RAM disk (initrd) is loaded. This is always the case, for
9181 instance, for the root file system.
9183 @item @code{check?} (default: @code{#t})
9184 This Boolean indicates whether the file system needs to be checked for
9185 errors before being mounted.
9187 @item @code{create-mount-point?} (default: @code{#f})
9188 When true, the mount point is created if it does not exist yet.
9190 @item @code{dependencies} (default: @code{'()})
9191 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
9192 representing file systems that must be mounted or mapped devices that
9193 must be opened before (and unmounted or closed after) this one.
9195 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
9196 a dependency of @file{/sys/fs/cgroup/cpu} and
9197 @file{/sys/fs/cgroup/memory}.
9199 Another example is a file system that depends on a mapped device, for
9200 example for an encrypted partition (@pxref{Mapped Devices}).
9204 The @code{(gnu system file-systems)} exports the following useful
9207 @defvr {Scheme Variable} %base-file-systems
9208 These are essential file systems that are required on normal systems,
9209 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
9210 below.) Operating system declarations should always contain at least
9214 @defvr {Scheme Variable} %pseudo-terminal-file-system
9215 This is the file system to be mounted as @file{/dev/pts}. It supports
9216 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
9217 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
9218 Manual}). Pseudo-terminals are used by terminal emulators such as
9222 @defvr {Scheme Variable} %shared-memory-file-system
9223 This file system is mounted as @file{/dev/shm} and is used to support
9224 memory sharing across processes (@pxref{Memory-mapped I/O,
9225 @code{shm_open},, libc, The GNU C Library Reference Manual}).
9228 @defvr {Scheme Variable} %immutable-store
9229 This file system performs a read-only ``bind mount'' of
9230 @file{/gnu/store}, making it read-only for all the users including
9231 @code{root}. This prevents against accidental modification by software
9232 running as @code{root} or by system administrators.
9234 The daemon itself is still able to write to the store: it remounts it
9235 read-write in its own ``name space.''
9238 @defvr {Scheme Variable} %binary-format-file-system
9239 The @code{binfmt_misc} file system, which allows handling of arbitrary
9240 executable file types to be delegated to user space. This requires the
9241 @code{binfmt.ko} kernel module to be loaded.
9244 @defvr {Scheme Variable} %fuse-control-file-system
9245 The @code{fusectl} file system, which allows unprivileged users to mount
9246 and unmount user-space FUSE file systems. This requires the
9247 @code{fuse.ko} kernel module to be loaded.
9250 @node Mapped Devices
9251 @subsection Mapped Devices
9253 @cindex device mapping
9254 @cindex mapped devices
9255 The Linux kernel has a notion of @dfn{device mapping}: a block device,
9256 such as a hard disk partition, can be @dfn{mapped} into another device,
9257 usually in @code{/dev/mapper/},
9258 with additional processing over the data that flows through
9259 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
9260 concept of a ``mapped device'' and that of a file system: both boil down
9261 to @emph{translating} input/output operations made on a file to
9262 operations on its backing store. Thus, the Hurd implements mapped
9263 devices, like file systems, using the generic @dfn{translator} mechanism
9264 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
9265 typical example is encryption device mapping: all writes to the mapped
9266 device are encrypted, and all reads are deciphered, transparently.
9267 Guix extends this notion by considering any device or set of devices that
9268 are @dfn{transformed} in some way to create a new device; for instance,
9269 RAID devices are obtained by @dfn{assembling} several other devices, such
9270 as hard disks or partitions, into a new one that behaves as one partition.
9271 Other examples, not yet implemented, are LVM logical volumes.
9273 Mapped devices are declared using the @code{mapped-device} form,
9274 defined as follows; for examples, see below.
9276 @deftp {Data Type} mapped-device
9277 Objects of this type represent device mappings that will be made when
9278 the system boots up.
9282 This is either a string specifying the name of the block device to be mapped,
9283 such as @code{"/dev/sda3"}, or a list of such strings when several devices
9284 need to be assembled for creating a new one.
9287 This string specifies the name of the resulting mapped device. For
9288 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
9289 specifying @code{"my-partition"} leads to the creation of
9290 the @code{"/dev/mapper/my-partition"} device.
9291 For RAID devices of type @code{raid-device-mapping}, the full device name
9292 such as @code{"/dev/md0"} needs to be given.
9295 This must be a @code{mapped-device-kind} object, which specifies how
9296 @var{source} is mapped to @var{target}.
9300 @defvr {Scheme Variable} luks-device-mapping
9301 This defines LUKS block device encryption using the @command{cryptsetup}
9302 command from the package with the same name. It relies on the
9303 @code{dm-crypt} Linux kernel module.
9306 @defvr {Scheme Variable} raid-device-mapping
9307 This defines a RAID device, which is assembled using the @code{mdadm}
9308 command from the package with the same name. It requires a Linux kernel
9309 module for the appropriate RAID level to be loaded, such as @code{raid456}
9310 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
9313 @cindex disk encryption
9315 The following example specifies a mapping from @file{/dev/sda3} to
9316 @file{/dev/mapper/home} using LUKS---the
9317 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
9318 standard mechanism for disk encryption.
9319 The @file{/dev/mapper/home}
9320 device can then be used as the @code{device} of a @code{file-system}
9321 declaration (@pxref{File Systems}).
9325 (source "/dev/sda3")
9327 (type luks-device-mapping))
9330 Alternatively, to become independent of device numbering, one may obtain
9331 the LUKS UUID (@dfn{unique identifier}) of the source device by a
9335 cryptsetup luksUUID /dev/sda3
9338 and use it as follows:
9342 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
9344 (type luks-device-mapping))
9347 @cindex swap encryption
9348 It is also desirable to encrypt swap space, since swap space may contain
9349 sensitive data. One way to accomplish that is to use a swap file in a
9350 file system on a device mapped via LUKS encryption. In this way, the
9351 swap file is encrypted because the entire device is encrypted.
9352 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
9354 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
9355 may be declared as follows:
9359 (source (list "/dev/sda1" "/dev/sdb1"))
9361 (type raid-device-mapping))
9364 The @file{/dev/md0} device can then be used as the @code{device} of a
9365 @code{file-system} declaration (@pxref{File Systems}).
9366 Note that the RAID level need not be given; it is chosen during the
9367 initial creation and formatting of the RAID device and is determined
9368 automatically later.
9372 @subsection User Accounts
9376 @cindex user accounts
9377 User accounts and groups are entirely managed through the
9378 @code{operating-system} declaration. They are specified with the
9379 @code{user-account} and @code{user-group} forms:
9385 (supplementary-groups '("wheel" ;allow use of sudo, etc.
9387 "video" ;video devices such as webcams
9388 "cdrom")) ;the good ol' CD-ROM
9389 (comment "Bob's sister")
9390 (home-directory "/home/alice"))
9393 When booting or upon completion of @command{guix system reconfigure},
9394 the system ensures that only the user accounts and groups specified in
9395 the @code{operating-system} declaration exist, and with the specified
9396 properties. Thus, account or group creations or modifications made by
9397 directly invoking commands such as @command{useradd} are lost upon
9398 reconfiguration or reboot. This ensures that the system remains exactly
9401 @deftp {Data Type} user-account
9402 Objects of this type represent user accounts. The following members may
9407 The name of the user account.
9411 This is the name (a string) or identifier (a number) of the user group
9412 this account belongs to.
9414 @item @code{supplementary-groups} (default: @code{'()})
9415 Optionally, this can be defined as a list of group names that this
9418 @item @code{uid} (default: @code{#f})
9419 This is the user ID for this account (a number), or @code{#f}. In the
9420 latter case, a number is automatically chosen by the system when the
9423 @item @code{comment} (default: @code{""})
9424 A comment about the account, such as the account owner's full name.
9426 @item @code{home-directory}
9427 This is the name of the home directory for the account.
9429 @item @code{create-home-directory?} (default: @code{#t})
9430 Indicates whether the home directory of this account should be created
9431 if it does not exist yet.
9433 @item @code{shell} (default: Bash)
9434 This is a G-expression denoting the file name of a program to be used as
9435 the shell (@pxref{G-Expressions}).
9437 @item @code{system?} (default: @code{#f})
9438 This Boolean value indicates whether the account is a ``system''
9439 account. System accounts are sometimes treated specially; for instance,
9440 graphical login managers do not list them.
9442 @anchor{user-account-password}
9443 @item @code{password} (default: @code{#f})
9444 You would normally leave this field to @code{#f}, initialize user
9445 passwords as @code{root} with the @command{passwd} command, and then let
9446 users change it with @command{passwd}. Passwords set with
9447 @command{passwd} are of course preserved across reboot and
9450 If you @emph{do} want to have a preset password for an account, then
9451 this field must contain the encrypted password, as a string.
9452 @xref{crypt,,, libc, The GNU C Library Reference Manual}, for more information
9453 on password encryption, and @ref{Encryption,,, guile, GNU Guile Reference
9454 Manual}, for information on Guile's @code{crypt} procedure.
9460 User group declarations are even simpler:
9463 (user-group (name "students"))
9466 @deftp {Data Type} user-group
9467 This type is for, well, user groups. There are just a few fields:
9471 The name of the group.
9473 @item @code{id} (default: @code{#f})
9474 The group identifier (a number). If @code{#f}, a new number is
9475 automatically allocated when the group is created.
9477 @item @code{system?} (default: @code{#f})
9478 This Boolean value indicates whether the group is a ``system'' group.
9479 System groups have low numerical IDs.
9481 @item @code{password} (default: @code{#f})
9482 What, user groups can have a password? Well, apparently yes. Unless
9483 @code{#f}, this field specifies the password of the group.
9488 For convenience, a variable lists all the basic user groups one may
9491 @defvr {Scheme Variable} %base-groups
9492 This is the list of basic user groups that users and/or packages expect
9493 to be present on the system. This includes groups such as ``root'',
9494 ``wheel'', and ``users'', as well as groups used to control access to
9495 specific devices such as ``audio'', ``disk'', and ``cdrom''.
9498 @defvr {Scheme Variable} %base-user-accounts
9499 This is the list of basic system accounts that programs may expect to
9500 find on a GNU/Linux system, such as the ``nobody'' account.
9502 Note that the ``root'' account is not included here. It is a
9503 special-case and is automatically added whether or not it is specified.
9510 A @dfn{locale} defines cultural conventions for a particular language
9511 and region of the world (@pxref{Locales,,, libc, The GNU C Library
9512 Reference Manual}). Each locale has a name that typically has the form
9513 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
9514 @code{fr_LU.utf8} designates the locale for the French language, with
9515 cultural conventions from Luxembourg, and using the UTF-8 encoding.
9517 @cindex locale definition
9518 Usually, you will want to specify the default locale for the machine
9519 using the @code{locale} field of the @code{operating-system} declaration
9520 (@pxref{operating-system Reference, @code{locale}}).
9522 The selected locale is automatically added to the @dfn{locale
9523 definitions} known to the system if needed, with its codeset inferred
9524 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
9525 @code{UTF-8} codeset. Additional locale definitions can be specified in
9526 the @code{locale-definitions} slot of @code{operating-system}---this is
9527 useful, for instance, if the codeset could not be inferred from the
9528 locale name. The default set of locale definitions includes some widely
9529 used locales, but not all the available locales, in order to save space.
9531 For instance, to add the North Frisian locale for Germany, the value of
9535 (cons (locale-definition
9536 (name "fy_DE.utf8") (source "fy_DE"))
9537 %default-locale-definitions)
9540 Likewise, to save space, one might want @code{locale-definitions} to
9541 list only the locales that are actually used, as in:
9544 (list (locale-definition
9545 (name "ja_JP.eucjp") (source "ja_JP")
9546 (charset "EUC-JP")))
9550 The compiled locale definitions are available at
9551 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
9552 version, which is the default location where the GNU@tie{}libc provided
9553 by Guix looks for locale data. This can be overridden using the
9554 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
9555 @code{LOCPATH} and locale packages}).
9557 The @code{locale-definition} form is provided by the @code{(gnu system
9558 locale)} module. Details are given below.
9560 @deftp {Data Type} locale-definition
9561 This is the data type of a locale definition.
9566 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
9567 Reference Manual}, for more information on locale names.
9570 The name of the source for that locale. This is typically the
9571 @code{@var{language}_@var{territory}} part of the locale name.
9573 @item @code{charset} (default: @code{"UTF-8"})
9574 The ``character set'' or ``code set'' for that locale,
9575 @uref{http://www.iana.org/assignments/character-sets, as defined by
9581 @defvr {Scheme Variable} %default-locale-definitions
9582 A list of commonly used UTF-8 locales, used as the default
9583 value of the @code{locale-definitions} field of @code{operating-system}
9587 @cindex normalized codeset in locale names
9588 These locale definitions use the @dfn{normalized codeset} for the part
9589 that follows the dot in the name (@pxref{Using gettextized software,
9590 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
9591 instance it has @code{uk_UA.utf8} but @emph{not}, say,
9595 @subsubsection Locale Data Compatibility Considerations
9597 @cindex incompatibility, of locale data
9598 @code{operating-system} declarations provide a @code{locale-libcs} field
9599 to specify the GNU@tie{}libc packages that are used to compile locale
9600 declarations (@pxref{operating-system Reference}). ``Why would I
9601 care?'', you may ask. Well, it turns out that the binary format of
9602 locale data is occasionally incompatible from one libc version to
9605 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
9606 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
9607 For instance, a program linked against libc version 2.21 is unable to
9608 read locale data produced with libc 2.22; worse, that program
9609 @emph{aborts} instead of simply ignoring the incompatible locale
9610 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
9611 the incompatible locale data, which is already an improvement.}.
9612 Similarly, a program linked against libc 2.22 can read most, but not
9613 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
9614 data is incompatible); thus calls to @code{setlocale} may fail, but
9615 programs will not abort.
9617 The ``problem'' in GuixSD is that users have a lot of freedom: They can
9618 choose whether and when to upgrade software in their profiles, and might
9619 be using a libc version different from the one the system administrator
9620 used to build the system-wide locale data.
9622 Fortunately, unprivileged users can also install their own locale data
9623 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
9624 @code{GUIX_LOCPATH} and locale packages}).
9626 Still, it is best if the system-wide locale data at
9627 @file{/run/current-system/locale} is built for all the libc versions
9628 actually in use on the system, so that all the programs can access
9629 it---this is especially crucial on a multi-user system. To do that, the
9630 administrator can specify several libc packages in the
9631 @code{locale-libcs} field of @code{operating-system}:
9634 (use-package-modules base)
9638 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
9641 This example would lead to a system containing locale definitions for
9642 both libc 2.21 and the current version of libc in
9643 @file{/run/current-system/locale}.
9647 @subsection Services
9649 @cindex system services
9650 An important part of preparing an @code{operating-system} declaration is
9651 listing @dfn{system services} and their configuration (@pxref{Using the
9652 Configuration System}). System services are typically daemons launched
9653 when the system boots, or other actions needed at that time---e.g.,
9654 configuring network access.
9656 GuixSD has a broad definition of ``service'' (@pxref{Service
9657 Composition}), but many services are managed by the GNU@tie{}Shepherd
9658 (@pxref{Shepherd Services}). On a running system, the @command{herd}
9659 command allows you to list the available services, show their status,
9660 start and stop them, or do other specific operations (@pxref{Jump
9661 Start,,, shepherd, The GNU Shepherd Manual}). For example:
9667 The above command, run as @code{root}, lists the currently defined
9668 services. The @command{herd doc} command shows a synopsis of the given
9673 Run libc's name service cache daemon (nscd).
9676 The @command{start}, @command{stop}, and @command{restart} sub-commands
9677 have the effect you would expect. For instance, the commands below stop
9678 the nscd service and restart the Xorg display server:
9682 Service nscd has been stopped.
9683 # herd restart xorg-server
9684 Service xorg-server has been stopped.
9685 Service xorg-server has been started.
9688 The following sections document the available services, starting with
9689 the core services, that may be used in an @code{operating-system}
9693 * Base Services:: Essential system services.
9694 * Scheduled Job Execution:: The mcron service.
9695 * Log Rotation:: The rottlog service.
9696 * Networking Services:: Network setup, SSH daemon, etc.
9697 * X Window:: Graphical display.
9698 * Printing Services:: Local and remote printer support.
9699 * Desktop Services:: D-Bus and desktop services.
9700 * Database Services:: SQL databases, key-value stores, etc.
9701 * Mail Services:: IMAP, POP3, SMTP, and all that.
9702 * Messaging Services:: Messaging services.
9703 * Telephony Services:: Telephony services.
9704 * Monitoring Services:: Monitoring services.
9705 * Kerberos Services:: Kerberos services.
9706 * Web Services:: Web servers.
9707 * Certificate Services:: TLS certificates via Let's Encrypt.
9708 * DNS Services:: DNS daemons.
9709 * VPN Services:: VPN daemons.
9710 * Network File System:: NFS related services.
9711 * Continuous Integration:: The Cuirass service.
9712 * Power management Services:: The TLP tool.
9713 * Audio Services:: The MPD.
9714 * Virtualization Services:: Virtualization services.
9715 * Version Control Services:: Providing remote access to Git repositories.
9716 * Game Services:: Game servers.
9717 * Miscellaneous Services:: Other services.
9721 @subsubsection Base Services
9723 The @code{(gnu services base)} module provides definitions for the basic
9724 services that one expects from the system. The services exported by
9725 this module are listed below.
9727 @defvr {Scheme Variable} %base-services
9728 This variable contains a list of basic services (@pxref{Service Types
9729 and Services}, for more information on service objects) one would
9730 expect from the system: a login service (mingetty) on each tty, syslogd,
9731 the libc name service cache daemon (nscd), the udev device manager, and
9734 This is the default value of the @code{services} field of
9735 @code{operating-system} declarations. Usually, when customizing a
9736 system, you will want to append services to @var{%base-services}, like
9740 (cons* (avahi-service) (lsh-service) %base-services)
9744 @defvr {Scheme Variable} special-files-service-type
9745 This is the service that sets up ``special files'' such as
9746 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
9748 The value associated with @code{special-files-service-type} services
9749 must be a list of tuples where the first element is the ``special file''
9750 and the second element is its target. By default it is:
9752 @cindex @file{/bin/sh}
9753 @cindex @file{sh}, in @file{/bin}
9755 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
9758 @cindex @file{/usr/bin/env}
9759 @cindex @file{env}, in @file{/usr/bin}
9760 If you want to add, say, @code{/usr/bin/env} to your system, you can
9764 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
9765 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
9768 Since this is part of @code{%base-services}, you can use
9769 @code{modify-services} to customize the set of special files
9770 (@pxref{Service Reference, @code{modify-services}}). But the simple way
9771 to add a special file is @i{via} the @code{extra-special-file} procedure
9775 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
9776 Use @var{target} as the ``special file'' @var{file}.
9778 For example, adding the following lines to the @code{services} field of
9779 your operating system declaration leads to a @file{/usr/bin/env}
9783 (extra-special-file "/usr/bin/env"
9784 (file-append coreutils "/bin/env"))
9788 @deffn {Scheme Procedure} host-name-service @var{name}
9789 Return a service that sets the host name to @var{name}.
9792 @deffn {Scheme Procedure} login-service @var{config}
9793 Return a service to run login according to @var{config}, a
9794 @code{<login-configuration>} object, which specifies the message of the day,
9798 @deftp {Data Type} login-configuration
9799 This is the data type representing the configuration of login.
9804 @cindex message of the day
9805 A file-like object containing the ``message of the day''.
9807 @item @code{allow-empty-passwords?} (default: @code{#t})
9808 Allow empty passwords by default so that first-time users can log in when
9809 the 'root' account has just been created.
9814 @deffn {Scheme Procedure} mingetty-service @var{config}
9815 Return a service to run mingetty according to @var{config}, a
9816 @code{<mingetty-configuration>} object, which specifies the tty to run, among
9820 @deftp {Data Type} mingetty-configuration
9821 This is the data type representing the configuration of Mingetty, which
9822 provides the default implementation of virtual console log-in.
9827 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
9829 @item @code{auto-login} (default: @code{#f})
9830 When true, this field must be a string denoting the user name under
9831 which the system automatically logs in. When it is @code{#f}, a
9832 user name and password must be entered to log in.
9834 @item @code{login-program} (default: @code{#f})
9835 This must be either @code{#f}, in which case the default log-in program
9836 is used (@command{login} from the Shadow tool suite), or a gexp denoting
9837 the name of the log-in program.
9839 @item @code{login-pause?} (default: @code{#f})
9840 When set to @code{#t} in conjunction with @var{auto-login}, the user
9841 will have to press a key before the log-in shell is launched.
9843 @item @code{mingetty} (default: @var{mingetty})
9844 The Mingetty package to use.
9849 @deffn {Scheme Procedure} agetty-service @var{config}
9850 Return a service to run agetty according to @var{config}, an
9851 @code{<agetty-configuration>} object, which specifies the tty to run,
9855 @deftp {Data Type} agetty-configuration
9856 This is the data type representing the configuration of agetty, which
9857 implements virtual and serial console log-in. See the @code{agetty(8)}
9858 man page for more information.
9863 The name of the console this agetty runs on, as a string---e.g.,
9864 @code{"ttyS0"}. This argument is optional, it will default to
9865 a reasonable default serial port used by the kernel Linux.
9867 For this, if there is a value for an option @code{agetty.tty} in the kernel
9868 command line, agetty will extract the device name of the serial port
9869 from it and use that.
9871 If not and if there is a value for an option @code{console} with a tty in
9872 the Linux command line, agetty will extract the device name of the
9873 serial port from it and use that.
9875 In both cases, agetty will leave the other serial device settings
9876 (baud rate etc.) alone---in the hope that Linux pinned them to the
9879 @item @code{baud-rate} (default: @code{#f})
9880 A string containing a comma-separated list of one or more baud rates, in
9883 @item @code{term} (default: @code{#f})
9884 A string containing the value used for the @code{TERM} environment
9887 @item @code{eight-bits?} (default: @code{#f})
9888 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
9891 @item @code{auto-login} (default: @code{#f})
9892 When passed a login name, as a string, the specified user will be logged
9893 in automatically without prompting for their login name or password.
9895 @item @code{no-reset?} (default: @code{#f})
9896 When @code{#t}, don't reset terminal cflags (control modes).
9898 @item @code{host} (default: @code{#f})
9899 This accepts a string containing the "login_host", which will be written
9900 into the @file{/var/run/utmpx} file.
9902 @item @code{remote?} (default: @code{#f})
9903 When set to @code{#t} in conjunction with @var{host}, this will add an
9904 @code{-r} fakehost option to the command line of the login program
9905 specified in @var{login-program}.
9907 @item @code{flow-control?} (default: @code{#f})
9908 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
9910 @item @code{no-issue?} (default: @code{#f})
9911 When set to @code{#t}, the contents of the @file{/etc/issue} file will
9912 not be displayed before presenting the login prompt.
9914 @item @code{init-string} (default: @code{#f})
9915 This accepts a string that will be sent to the tty or modem before
9916 sending anything else. It can be used to initialize a modem.
9918 @item @code{no-clear?} (default: @code{#f})
9919 When set to @code{#t}, agetty will not clear the screen before showing
9922 @item @code{login-program} (default: (file-append shadow "/bin/login"))
9923 This must be either a gexp denoting the name of a log-in program, or
9924 unset, in which case the default value is the @command{login} from the
9927 @item @code{local-line} (default: @code{#f})
9928 Control the CLOCAL line flag. This accepts one of three symbols as
9929 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
9930 the default value chosen by agetty is @code{'auto}.
9932 @item @code{extract-baud?} (default: @code{#f})
9933 When set to @code{#t}, instruct agetty to try to extract the baud rate
9934 from the status messages produced by certain types of modems.
9936 @item @code{skip-login?} (default: @code{#f})
9937 When set to @code{#t}, do not prompt the user for a login name. This
9938 can be used with @var{login-program} field to use non-standard login
9941 @item @code{no-newline?} (default: @code{#f})
9942 When set to @code{#t}, do not print a newline before printing the
9943 @file{/etc/issue} file.
9945 @c Is this dangerous only when used with login-program, or always?
9946 @item @code{login-options} (default: @code{#f})
9947 This option accepts a string containing options that are passed to the
9948 login program. When used with the @var{login-program}, be aware that a
9949 malicious user could try to enter a login name containing embedded
9950 options that could be parsed by the login program.
9952 @item @code{login-pause} (default: @code{#f})
9953 When set to @code{#t}, wait for any key before showing the login prompt.
9954 This can be used in conjunction with @var{auto-login} to save memory by
9955 lazily spawning shells.
9957 @item @code{chroot} (default: @code{#f})
9958 Change root to the specified directory. This option accepts a directory
9961 @item @code{hangup?} (default: @code{#f})
9962 Use the Linux system call @code{vhangup} to do a virtual hangup of the
9965 @item @code{keep-baud?} (default: @code{#f})
9966 When set to @code{#t}, try to keep the existing baud rate. The baud
9967 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
9970 @item @code{timeout} (default: @code{#f})
9971 When set to an integer value, terminate if no user name could be read
9972 within @var{timeout} seconds.
9974 @item @code{detect-case?} (default: @code{#f})
9975 When set to @code{#t}, turn on support for detecting an uppercase-only
9976 terminal. This setting will detect a login name containing only
9977 uppercase letters as indicating an uppercase-only terminal and turn on
9978 some upper-to-lower case conversions. Note that this will not support
9981 @item @code{wait-cr?} (default: @code{#f})
9982 When set to @code{#t}, wait for the user or modem to send a
9983 carriage-return or linefeed character before displaying
9984 @file{/etc/issue} or login prompt. This is typically used with the
9985 @var{init-string} option.
9987 @item @code{no-hints?} (default: @code{#f})
9988 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
9991 @item @code{no-hostname?} (default: @code{#f})
9992 By default, the hostname is printed. When this option is set to
9993 @code{#t}, no hostname will be shown at all.
9995 @item @code{long-hostname?} (default: @code{#f})
9996 By default, the hostname is only printed until the first dot. When this
9997 option is set to @code{#t}, the fully qualified hostname by
9998 @code{gethostname} or @code{getaddrinfo} is shown.
10000 @item @code{erase-characters} (default: @code{#f})
10001 This option accepts a string of additional characters that should be
10002 interpreted as backspace when the user types their login name.
10004 @item @code{kill-characters} (default: @code{#f})
10005 This option accepts a string that should be interpreted to mean "ignore
10006 all previous characters" (also called a "kill" character) when the types
10009 @item @code{chdir} (default: @code{#f})
10010 This option accepts, as a string, a directory path that will be changed
10013 @item @code{delay} (default: @code{#f})
10014 This options accepts, as an integer, the number of seconds to sleep
10015 before opening the tty and displaying the login prompt.
10017 @item @code{nice} (default: @code{#f})
10018 This option accepts, as an integer, the nice value with which to run the
10019 @command{login} program.
10021 @item @code{extra-options} (default: @code{'()})
10022 This option provides an "escape hatch" for the user to provide arbitrary
10023 command-line arguments to @command{agetty} as a list of strings.
10028 @deffn {Scheme Procedure} kmscon-service-type @var{config}
10029 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
10030 according to @var{config}, a @code{<kmscon-configuration>} object, which
10031 specifies the tty to run, among other things.
10034 @deftp {Data Type} kmscon-configuration
10035 This is the data type representing the configuration of Kmscon, which
10036 implements virtual console log-in.
10040 @item @code{virtual-terminal}
10041 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
10043 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
10044 A gexp denoting the name of the log-in program. The default log-in program is
10045 @command{login} from the Shadow tool suite.
10047 @item @code{login-arguments} (default: @code{'("-p")})
10048 A list of arguments to pass to @command{login}.
10050 @item @code{hardware-acceleration?} (default: #f)
10051 Whether to use hardware acceleration.
10053 @item @code{kmscon} (default: @var{kmscon})
10054 The Kmscon package to use.
10059 @cindex name service cache daemon
10061 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
10062 [#:name-services '()]
10063 Return a service that runs the libc name service cache daemon (nscd) with the
10064 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
10065 Service Switch}, for an example.
10068 @defvr {Scheme Variable} %nscd-default-configuration
10069 This is the default @code{<nscd-configuration>} value (see below) used
10070 by @code{nscd-service}. It uses the caches defined by
10071 @var{%nscd-default-caches}; see below.
10074 @deftp {Data Type} nscd-configuration
10075 This is the data type representing the name service cache daemon (nscd)
10080 @item @code{name-services} (default: @code{'()})
10081 List of packages denoting @dfn{name services} that must be visible to
10082 the nscd---e.g., @code{(list @var{nss-mdns})}.
10084 @item @code{glibc} (default: @var{glibc})
10085 Package object denoting the GNU C Library providing the @command{nscd}
10088 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
10089 Name of the nscd log file. This is where debugging output goes when
10090 @code{debug-level} is strictly positive.
10092 @item @code{debug-level} (default: @code{0})
10093 Integer denoting the debugging levels. Higher numbers mean that more
10094 debugging output is logged.
10096 @item @code{caches} (default: @var{%nscd-default-caches})
10097 List of @code{<nscd-cache>} objects denoting things to be cached; see
10103 @deftp {Data Type} nscd-cache
10104 Data type representing a cache database of nscd and its parameters.
10108 @item @code{database}
10109 This is a symbol representing the name of the database to be cached.
10110 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
10111 @code{services}, which designate the corresponding NSS database
10112 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
10114 @item @code{positive-time-to-live}
10115 @itemx @code{negative-time-to-live} (default: @code{20})
10116 A number representing the number of seconds during which a positive or
10117 negative lookup result remains in cache.
10119 @item @code{check-files?} (default: @code{#t})
10120 Whether to check for updates of the files corresponding to
10123 For instance, when @var{database} is @code{hosts}, setting this flag
10124 instructs nscd to check for updates in @file{/etc/hosts} and to take
10127 @item @code{persistent?} (default: @code{#t})
10128 Whether the cache should be stored persistently on disk.
10130 @item @code{shared?} (default: @code{#t})
10131 Whether the cache should be shared among users.
10133 @item @code{max-database-size} (default: 32@tie{}MiB)
10134 Maximum size in bytes of the database cache.
10136 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
10137 @c settings, so leave them out.
10142 @defvr {Scheme Variable} %nscd-default-caches
10143 List of @code{<nscd-cache>} objects used by default by
10144 @code{nscd-configuration} (see above).
10146 It enables persistent and aggressive caching of service and host name
10147 lookups. The latter provides better host name lookup performance,
10148 resilience in the face of unreliable name servers, and also better
10149 privacy---often the result of host name lookups is in local cache, so
10150 external name servers do not even need to be queried.
10153 @anchor{syslog-configuration-type}
10156 @deftp {Data Type} syslog-configuration
10157 This data type represents the configuration of the syslog daemon.
10160 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
10161 The syslog daemon to use.
10163 @item @code{config-file} (default: @code{%default-syslog.conf})
10164 The syslog configuration file to use.
10169 @anchor{syslog-service}
10171 @deffn {Scheme Procedure} syslog-service @var{config}
10172 Return a service that runs a syslog daemon according to @var{config}.
10174 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
10175 information on the configuration file syntax.
10178 @anchor{guix-configuration-type}
10179 @deftp {Data Type} guix-configuration
10180 This data type represents the configuration of the Guix build daemon.
10181 @xref{Invoking guix-daemon}, for more information.
10184 @item @code{guix} (default: @var{guix})
10185 The Guix package to use.
10187 @item @code{build-group} (default: @code{"guixbuild"})
10188 Name of the group for build user accounts.
10190 @item @code{build-accounts} (default: @code{10})
10191 Number of build user accounts to create.
10193 @item @code{authorize-key?} (default: @code{#t})
10194 @cindex substitutes, authorization thereof
10195 Whether to authorize the substitute keys listed in
10196 @code{authorized-keys}---by default that of @code{hydra.gnu.org}
10197 (@pxref{Substitutes}).
10199 @vindex %default-authorized-guix-keys
10200 @item @code{authorized-keys} (default: @var{%default-authorized-guix-keys})
10201 The list of authorized key files for archive imports, as a list of
10202 string-valued gexps (@pxref{Invoking guix archive}). By default, it
10203 contains that of @code{hydra.gnu.org} (@pxref{Substitutes}).
10205 @item @code{use-substitutes?} (default: @code{#t})
10206 Whether to use substitutes.
10208 @item @code{substitute-urls} (default: @var{%default-substitute-urls})
10209 The list of URLs where to look for substitutes by default.
10211 @item @code{max-silent-time} (default: @code{0})
10212 @itemx @code{timeout} (default: @code{0})
10213 The number of seconds of silence and the number of seconds of activity,
10214 respectively, after which a build process times out. A value of zero
10215 disables the timeout.
10217 @item @code{log-compression} (default: @code{'bzip2})
10218 The type of compression used for build logs---one of @code{gzip},
10219 @code{bzip2}, or @code{none}.
10221 @item @code{extra-options} (default: @code{'()})
10222 List of extra command-line options for @command{guix-daemon}.
10224 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
10225 File where @command{guix-daemon}'s standard output and standard error
10228 @item @code{http-proxy} (default: @code{#f})
10229 The HTTP proxy used for downloading fixed-output derivations and
10232 @item @code{tmpdir} (default: @code{#f})
10233 A directory path where the @command{guix-daemon} will perform builds.
10238 @deffn {Scheme Procedure} guix-service @var{config}
10239 Return a service that runs the Guix build daemon according to
10243 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
10244 Run @var{udev}, which populates the @file{/dev} directory dynamically.
10245 udev rules can be provided as a list of files through the @var{rules}
10246 variable. The procedures @var{udev-rule} and @var{file->udev-rule} from
10247 @code{(gnu services base)} simplify the creation of such rule files.
10249 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
10250 Return a udev-rule file named @var{file-name} containing the rules
10251 defined by the @var{contents} literal.
10253 In the following example, a rule for a USB device is defined to be
10254 stored in the file @file{90-usb-thing.rules}. The rule runs a script
10255 upon detecting a USB device with a given product identifier.
10258 (define %example-udev-rule
10260 "90-usb-thing.rules"
10261 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
10262 "ATTR@{product@}==\"Example\", "
10263 "RUN+=\"/path/to/script\"")))
10267 Here we show how the default @var{udev-service} can be extended with it.
10273 (modify-services %desktop-services
10274 (udev-service-type config =>
10275 (udev-configuration (inherit config)
10276 (rules (append (udev-configuration-rules config)
10277 (list %example-udev-rule))))))))
10280 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
10281 Return a udev file named @var{file-name} containing the rules defined
10282 within @var{file}, a file-like object.
10284 The following example showcases how we can use an existing rule file.
10287 (use-modules (guix download) ;for url-fetch
10288 (guix packages) ;for origin
10291 (define %android-udev-rules
10293 "51-android-udev.rules"
10294 (let ((version "20170910"))
10297 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
10298 "android-udev-rules/" version "/51-android.rules"))
10300 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
10304 Additionally, Guix package definitions can be included in @var{rules} in
10305 order to extend the udev rules with the definitions found under their
10306 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
10307 @var{file->udev-rule} example, we could have used the
10308 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
10309 packages android)} module.
10311 The following example shows how to use the @var{android-udev-rules}
10312 package so that the Android tool @command{adb} can detect devices
10313 without root privileges. It also details how to create the
10314 @code{adbusers} group, which is required for the proper functioning of
10315 the rules defined within the @var{android-udev-rules} package. To
10316 create such a group, we must define it both as part of the
10317 @var{supplementary-groups} of our @var{user-account} declaration, as
10318 well as in the @var{groups} field of the @var{operating-system} record.
10321 (use-modules (gnu packages android) ;for android-udev-rules
10322 (gnu system shadow) ;for user-group
10327 (users (cons (user-acount
10329 (supplementary-groups
10330 '("adbusers" ;for adb
10331 "wheel" "netdev" "audio" "video"))
10334 (groups (cons (user-group (system? #t) (name "adbusers"))
10340 (modify-services %desktop-services
10341 (udev-service-type config =>
10342 (udev-configuration (inherit config)
10343 (rules (cons* android-udev-rules
10344 (udev-configuration-rules config))))))))
10348 @defvr {Scheme Variable} urandom-seed-service-type
10349 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
10350 when rebooting. It also tries to seed @file{/dev/urandom} from
10351 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
10355 @defvr {Scheme Variable} %random-seed-file
10356 This is the name of the file where some random bytes are saved by
10357 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
10358 It defaults to @file{/var/lib/random-seed}.
10363 @deffn {Scheme Procedure} console-keymap-service @var{files} ...
10364 @cindex keyboard layout
10365 Return a service to load console keymaps from @var{files} using
10366 @command{loadkeys} command. Most likely, you want to load some default
10367 keymap, which can be done like this:
10370 (console-keymap-service "dvorak")
10373 Or, for example, for a Swedish keyboard, you may need to combine
10374 the following keymaps:
10376 (console-keymap-service "se-lat6" "se-fi-lat6")
10379 Also you can specify a full file name (or file names) of your keymap(s).
10380 See @code{man loadkeys} for details.
10386 @deffn {Scheme Procedure} gpm-service [#:gpm @var{gpm}] @
10388 Run @var{gpm}, the general-purpose mouse daemon, with the given
10389 command-line @var{options}. GPM allows users to use the mouse in the console,
10390 notably to select, copy, and paste text. The default value of @var{options}
10391 uses the @code{ps2} protocol, which works for both USB and PS/2 mice.
10393 This service is not part of @var{%base-services}.
10396 @anchor{guix-publish-service-type}
10397 @deffn {Scheme Variable} guix-publish-service-type
10398 This is the service type for @command{guix publish} (@pxref{Invoking
10399 guix publish}). Its value must be a @code{guix-configuration}
10400 object, as described below.
10402 This assumes that @file{/etc/guix} already contains a signing key pair as
10403 created by @command{guix archive --generate-key} (@pxref{Invoking guix
10404 archive}). If that is not the case, the service will fail to start.
10407 @deftp {Data Type} guix-publish-configuration
10408 Data type representing the configuration of the @code{guix publish}
10412 @item @code{guix} (default: @code{guix})
10413 The Guix package to use.
10415 @item @code{port} (default: @code{80})
10416 The TCP port to listen for connections.
10418 @item @code{host} (default: @code{"localhost"})
10419 The host (and thus, network interface) to listen to. Use
10420 @code{"0.0.0.0"} to listen on all the network interfaces.
10422 @item @code{compression-level} (default: @code{3})
10423 The gzip compression level at which substitutes are compressed. Use
10424 @code{0} to disable compression altogether, and @code{9} to get the best
10425 compression ratio at the expense of increased CPU usage.
10427 @item @code{nar-path} (default: @code{"nar"})
10428 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
10429 publish, @code{--nar-path}}, for details.
10431 @item @code{cache} (default: @code{#f})
10432 When it is @code{#f}, disable caching and instead generate archives on
10433 demand. Otherwise, this should be the name of a directory---e.g.,
10434 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
10435 archives and meta-data ready to be sent. @xref{Invoking guix publish,
10436 @option{--cache}}, for more information on the tradeoffs involved.
10438 @item @code{workers} (default: @code{#f})
10439 When it is an integer, this is the number of worker threads used for
10440 caching; when @code{#f}, the number of processors is used.
10441 @xref{Invoking guix publish, @option{--workers}}, for more information.
10443 @item @code{ttl} (default: @code{#f})
10444 When it is an integer, this denotes the @dfn{time-to-live} in seconds
10445 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
10446 for more information.
10450 @anchor{rngd-service}
10451 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
10452 [#:device "/dev/hwrng"]
10453 Return a service that runs the @command{rngd} program from @var{rng-tools}
10454 to add @var{device} to the kernel's entropy pool. The service will fail if
10455 @var{device} does not exist.
10458 @anchor{pam-limits-service}
10459 @cindex session limits
10464 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
10466 Return a service that installs a configuration file for the
10467 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
10468 @code{pam_limits} module}. The procedure optionally takes a list of
10469 @code{pam-limits-entry} values, which can be used to specify
10470 @code{ulimit} limits and nice priority limits to user sessions.
10472 The following limits definition sets two hard and soft limits for all
10473 login sessions of users in the @code{realtime} group:
10476 (pam-limits-service
10478 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
10479 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
10482 The first entry increases the maximum realtime priority for
10483 non-privileged processes; the second entry lifts any restriction of the
10484 maximum address space that can be locked in memory. These settings are
10485 commonly used for real-time audio systems.
10488 @node Scheduled Job Execution
10489 @subsubsection Scheduled Job Execution
10493 @cindex scheduling jobs
10494 The @code{(gnu services mcron)} module provides an interface to
10495 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
10496 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
10497 Unix @command{cron} daemon; the main difference is that it is
10498 implemented in Guile Scheme, which provides a lot of flexibility when
10499 specifying the scheduling of jobs and their actions.
10501 The example below defines an operating system that runs the
10502 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
10503 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
10504 well as the @command{mkid} command on behalf of an unprivileged user
10505 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
10506 gexps to introduce job definitions that are passed to mcron
10507 (@pxref{G-Expressions}).
10510 (use-modules (guix) (gnu) (gnu services mcron))
10511 (use-package-modules base idutils)
10513 (define updatedb-job
10514 ;; Run 'updatedb' at 3AM every day. Here we write the
10515 ;; job's action as a Scheme procedure.
10516 #~(job '(next-hour '(3))
10518 (execl (string-append #$findutils "/bin/updatedb")
10520 "--prunepaths=/tmp /var/tmp /gnu/store"))))
10522 (define garbage-collector-job
10523 ;; Collect garbage 5 minutes after midnight every day.
10524 ;; The job's action is a shell command.
10525 #~(job "5 0 * * *" ;Vixie cron syntax
10528 (define idutils-job
10529 ;; Update the index database as user "charlie" at 12:15PM
10530 ;; and 19:15PM. This runs from the user's home directory.
10531 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
10532 (string-append #$idutils "/bin/mkid src")
10537 (services (cons (mcron-service (list garbage-collector-job
10543 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
10544 for more information on mcron job specifications. Below is the
10545 reference of the mcron service.
10547 @deffn {Scheme Procedure} mcron-service @var{jobs} [#:mcron @var{mcron}]
10548 Return an mcron service running @var{mcron} that schedules @var{jobs}, a
10549 list of gexps denoting mcron job specifications.
10551 This is a shorthand for:
10553 (service mcron-service-type
10554 (mcron-configuration (mcron mcron) (jobs jobs)))
10558 @defvr {Scheme Variable} mcron-service-type
10559 This is the type of the @code{mcron} service, whose value is an
10560 @code{mcron-configuration} object.
10562 This service type can be the target of a service extension that provides
10563 it additional job specifications (@pxref{Service Composition}). In
10564 other words, it is possible to define services that provide additional
10568 @deftp {Data Type} mcron-configuration
10569 Data type representing the configuration of mcron.
10572 @item @code{mcron} (default: @var{mcron})
10573 The mcron package to use.
10576 This is a list of gexps (@pxref{G-Expressions}), where each gexp
10577 corresponds to an mcron job specification (@pxref{Syntax, mcron job
10578 specifications,, mcron, GNU@tie{}mcron}).
10584 @subsubsection Log Rotation
10587 @cindex log rotation
10589 Log files such as those found in @file{/var/log} tend to grow endlessly,
10590 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
10591 their contents in separate files, possibly compressed. The @code{(gnu
10592 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
10593 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
10595 The example below defines an operating system that provides log rotation
10596 with the default settings, for commonly encountered log files.
10599 (use-modules (guix) (gnu))
10600 (use-service-modules admin mcron)
10601 (use-package-modules base idutils)
10605 (services (cons (service rottlog-service-type)
10609 @defvr {Scheme Variable} rottlog-service-type
10610 This is the type of the Rottlog service, whose value is a
10611 @code{rottlog-configuration} object.
10613 Other services can extend this one with new @code{log-rotation} objects
10614 (see below), thereby augmenting the set of files to be rotated.
10616 This service type can define mcron jobs (@pxref{Scheduled Job
10617 Execution}) to run the rottlog service.
10620 @deftp {Data Type} rottlog-configuration
10621 Data type representing the configuration of rottlog.
10624 @item @code{rottlog} (default: @code{rottlog})
10625 The Rottlog package to use.
10627 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
10628 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
10629 rottlog, GNU Rot[t]log Manual}).
10631 @item @code{rotations} (default: @code{%default-rotations})
10632 A list of @code{log-rotation} objects as defined below.
10635 This is a list of gexps where each gexp corresponds to an mcron job
10636 specification (@pxref{Scheduled Job Execution}).
10640 @deftp {Data Type} log-rotation
10641 Data type representing the rotation of a group of log files.
10643 Taking an example from the Rottlog manual (@pxref{Period Related File
10644 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
10650 (files '("/var/log/apache/*"))
10651 (options '("storedir apache-archives"
10657 The list of fields is as follows:
10660 @item @code{frequency} (default: @code{'weekly})
10661 The log rotation frequency, a symbol.
10664 The list of files or file glob patterns to rotate.
10666 @item @code{options} (default: @code{'()})
10667 The list of rottlog options for this rotation (@pxref{Configuration
10668 parameters,,, rottlog, GNU Rot[t]lg Manual}).
10670 @item @code{post-rotate} (default: @code{#f})
10671 Either @code{#f} or a gexp to execute once the rotation has completed.
10675 @defvr {Scheme Variable} %default-rotations
10676 Specifies weekly rotation of @var{%rotated-files} and
10677 a couple of other files.
10680 @defvr {Scheme Variable} %rotated-files
10681 The list of syslog-controlled files to be rotated. By default it is:
10682 @code{'("/var/log/messages" "/var/log/secure")}.
10685 @node Networking Services
10686 @subsubsection Networking Services
10688 The @code{(gnu services networking)} module provides services to configure
10689 the network interface.
10691 @cindex DHCP, networking service
10692 @deffn {Scheme Procedure} dhcp-client-service [#:dhcp @var{isc-dhcp}]
10693 Return a service that runs @var{dhcp}, a Dynamic Host Configuration
10694 Protocol (DHCP) client, on all the non-loopback network interfaces.
10697 @defvr {Scheme Variable} static-networking-service-type
10698 This is the type for statically-configured network interfaces.
10699 @c TODO Document <static-networking> data structures.
10702 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
10703 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}]
10704 [#:requirement @code{'(udev)}]
10705 Return a service that starts @var{interface} with address @var{ip}. If
10706 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
10707 it must be a string specifying the default network gateway. @var{requirement}
10708 can be used to declare a dependency on another service before configuring the
10711 This procedure can be called several times, one for each network
10712 interface of interest. Behind the scenes what it does is extend
10713 @code{static-networking-service-type} with additional network interfaces
10720 @cindex network management
10721 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
10722 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
10723 management daemon that aims to simplify wired and wireless networking.
10725 This service adds the @var{wicd} package to the global profile, providing
10726 several commands to interact with the daemon and configure networking:
10727 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
10728 and @command{wicd-curses} user interfaces.
10731 @cindex NetworkManager
10733 @defvr {Scheme Variable} network-manager-service-type
10734 This is the service type for the
10735 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
10736 service. The value for this service type is a
10737 @code{network-manager-configuration} record.
10739 This service is part of @code{%desktop-services} (@pxref{Desktop
10743 @deftp {Data Type} network-manager-configuration
10744 Data type representing the configuration of NetworkManager.
10747 @item @code{network-manager} (default: @code{network-manager})
10748 The NetworkManager package to use.
10750 @item @code{dns} (default: @code{"default"})
10751 Processing mode for DNS, which affects how NetworkManager uses the
10752 @code{resolv.conf} configuration file.
10756 NetworkManager will update @code{resolv.conf} to reflect the nameservers
10757 provided by currently active connections.
10760 NetworkManager will run @code{dnsmasq} as a local caching nameserver,
10761 using a "split DNS" configuration if you are connected to a VPN, and
10762 then update @code{resolv.conf} to point to the local nameserver.
10765 NetworkManager will not modify @code{resolv.conf}.
10768 @item @code{vpn-plugins} (default: @code{'()})
10769 This is the list of available plugins for virtual private networks
10770 (VPNs). An example of this is the @code{network-manager-openvpn}
10771 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
10777 @deffn {Scheme Variable} connman-service-type
10778 This is the service type to run @url{https://01.org/connman,Connman},
10779 a network connection manager.
10781 Its value must be an
10782 @code{connman-configuration} record as in this example:
10785 (service connman-service-type
10786 (connman-configuration
10787 (disable-vpn? #t)))
10790 See below for details about @code{connman-configuration}.
10793 @deftp {Data Type} connman-configuration
10794 Data Type representing the configuration of connman.
10797 @item @code{connman} (default: @var{connman})
10798 The connman package to use.
10800 @item @code{disable-vpn?} (default: @code{#f})
10801 When true, enable connman's vpn plugin.
10805 @cindex WPA Supplicant
10806 @defvr {Scheme Variable} wpa-supplicant-service-type
10807 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
10808 supplicant}, an authentication daemon required to authenticate against
10809 encrypted WiFi or ethernet networks. It is configured to listen for
10812 The value of this service is the @code{wpa-supplicant} package to use.
10813 Thus, it can be instantiated like this:
10816 (use-modules (gnu services networking))
10818 (service wpa-supplicant-service-type)
10823 @cindex real time clock
10824 @deffn {Scheme Procedure} ntp-service [#:ntp @var{ntp}] @
10825 [#:servers @var{%ntp-servers}] @
10826 [#:allow-large-adjustment? #f]
10827 Return a service that runs the daemon from @var{ntp}, the
10828 @uref{http://www.ntp.org, Network Time Protocol package}. The daemon will
10829 keep the system clock synchronized with that of @var{servers}.
10830 @var{allow-large-adjustment?} determines whether @command{ntpd} is allowed to
10831 make an initial adjustment of more than 1,000 seconds.
10834 @defvr {Scheme Variable} %ntp-servers
10835 List of host names used as the default NTP servers.
10839 @deffn {Scheme Procedure} openntpd-service-type
10840 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
10841 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
10842 clock synchronized with that of the given servers.
10846 openntpd-service-type
10847 (openntpd-configuration
10848 (listen-on '("127.0.0.1" "::1"))
10849 (sensor '("udcf0 correction 70000"))
10850 (constraint-from '("www.gnu.org"))
10851 (constraints-from '("https://www.google.com/"))
10852 (allow-large-adjustment? #t)))
10857 @deftp {Data Type} openntpd-configuration
10859 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
10860 The openntpd executable to use.
10861 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
10862 A list of local IP addresses or hostnames the ntpd daemon should listen on.
10863 @item @code{query-from} (default: @code{'()})
10864 A list of local IP address the ntpd daemon should use for outgoing queries.
10865 @item @code{sensor} (default: @code{'()})
10866 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
10867 will listen to each sensor that acutally exists and ignore non-existant ones.
10868 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
10870 @item @code{server} (default: @var{%ntp-servers})
10871 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
10872 @item @code{servers} (default: @code{'()})
10873 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
10874 @item @code{constraint-from} (default: @code{'()})
10875 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
10876 This time information is not used for precision but acts as an authenticated
10877 constraint, thereby reducing the impact of unauthenticated NTP
10878 man-in-the-middle attacks.
10879 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
10881 @item @code{constraints-from} (default: @code{'()})
10882 As with constraint from, specify a list of URLs, IP addresses or hostnames of
10883 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
10884 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
10885 @item @code{allow-large-adjustment?} (default: @code{#f})
10886 Determines if @code{ntpd} is allowed to make an initial adjustment of more
10892 @deffn {Scheme variable} inetd-service-type
10893 This service runs the @command{inetd} (@pxref{inetd invocation,,,
10894 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
10895 connections on internet sockets, and lazily starts the specified server
10896 program when a connection is made on one of these sockets.
10898 The value of this service is an @code{inetd-configuration} object. The
10899 following example configures the @command{inetd} daemon to provide the
10900 built-in @command{echo} service, as well as an smtp service which
10901 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
10902 gateway @code{hostname}:
10907 (inetd-configuration
10911 (socket-type 'stream)
10918 (socket-type 'stream)
10922 (program (file-append openssh "/bin/ssh"))
10924 '("ssh" "-qT" "-i" "/path/to/ssh_key"
10925 "-W" "smtp-server:25" "user@@hostname")))))
10928 See below for more details about @code{inetd-configuration}.
10931 @deftp {Data Type} inetd-configuration
10932 Data type representing the configuration of @command{inetd}.
10935 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
10936 The @command{inetd} executable to use.
10938 @item @code{entries} (default: @code{'()})
10939 A list of @command{inetd} service entries. Each entry should be created
10940 by the @code{inetd-entry} constructor.
10944 @deftp {Data Type} inetd-entry
10945 Data type representing an entry in the @command{inetd} configuration.
10946 Each entry corresponds to a socket where @command{inetd} will listen for
10950 @item @code{node} (default: @code{#f})
10951 Optional string, a comma-separated list of local addresses
10952 @command{inetd} should use when listening for this service.
10953 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
10954 description of all options.
10956 A string, the name must correspond to an entry in @code{/etc/services}.
10957 @item @code{socket-type}
10958 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
10960 @item @code{protocol}
10961 A string, must correspond to an entry in @code{/etc/protocols}.
10962 @item @code{wait?} (default: @code{#t})
10963 Whether @command{inetd} should wait for the server to exit before
10964 listening to new service requests.
10966 A string containing the user (and, optionally, group) name of the user
10967 as whom the server should run. The group name can be specified in a
10968 suffix, separated by a colon or period, i.e. @code{"user"},
10969 @code{"user:group"} or @code{"user.group"}.
10970 @item @code{program} (default: @code{"internal"})
10971 The server program which will serve the requests, or @code{"internal"}
10972 if @command{inetd} should use a built-in service.
10973 @item @code{arguments} (default: @code{'()})
10974 A list strings or file-like objects, which are the server program's
10975 arguments, starting with the zeroth argument, i.e. the name of the
10976 program itself. For @command{inetd}'s internal services, this entry
10977 must be @code{'()} or @code{'("internal")}.
10980 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
10981 detailed discussion of each configuration field.
10985 @deffn {Scheme Procedure} tor-service [@var{config-file}] [#:tor @var{tor}]
10986 Return a service to run the @uref{https://torproject.org, Tor} anonymous
10989 The daemon runs as the @code{tor} unprivileged user. It is passed
10990 @var{config-file}, a file-like object, with an additional @code{User tor} line
10991 and lines for hidden services added via @code{tor-hidden-service}. Run
10992 @command{man tor} for information about the configuration file.
10995 @cindex hidden service
10996 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
10997 Define a new Tor @dfn{hidden service} called @var{name} and implementing
10998 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
11001 '((22 "127.0.0.1:22")
11002 (80 "127.0.0.1:8080"))
11005 In this example, port 22 of the hidden service is mapped to local port 22, and
11006 port 80 is mapped to local port 8080.
11008 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
11009 the @file{hostname} file contains the @code{.onion} host name for the hidden
11012 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
11013 project's documentation} for more information.
11016 The @code{(gnu services rsync)} module provides the following services:
11018 You might want an rsync daemon if you have files that you want available
11019 so anyone (or just yourself) can download existing files or upload new
11022 @deffn {Scheme Variable} rsync-service-type
11023 This is the type for the @uref{https://rsync.samba.org, rsync} rsync daemon,
11024 @command{rsync-configuration} record as in this example:
11027 (service rsync-service-type)
11030 See below for details about @code{rsync-configuration}.
11033 @deftp {Data Type} rsync-configuration
11034 Data type representing the configuration for @code{rsync-service}.
11037 @item @code{package} (default: @var{rsync})
11038 @code{rsync} package to use.
11040 @item @code{port-number} (default: @code{873})
11041 TCP port on which @command{rsync} listens for incoming connections. If port
11042 is less than @code{1024} @command{rsync} needs to be started as the
11043 @code{root} user and group.
11045 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
11046 Name of the file where @command{rsync} writes its PID.
11048 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
11049 Name of the file where @command{rsync} writes its lock file.
11051 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
11052 Name of the file where @command{rsync} writes its log file.
11054 @item @code{use-chroot?} (default: @var{#t})
11055 Whether to use chroot for @command{rsync} shared directory.
11057 @item @code{share-path} (default: @file{/srv/rsync})
11058 Location of the @command{rsync} shared directory.
11060 @item @code{share-comment} (default: @code{"Rsync share"})
11061 Comment of the @command{rsync} shared directory.
11063 @item @code{read-only?} (default: @var{#f})
11064 Read-write permissions to shared directory.
11066 @item @code{timeout} (default: @code{300})
11067 I/O timeout in seconds.
11069 @item @code{user} (default: @var{"root"})
11070 Owner of the @code{rsync} process.
11072 @item @code{group} (default: @var{"root"})
11073 Group of the @code{rsync} process.
11075 @item @code{uid} (default: @var{"rsyncd"})
11076 User name or user ID that file transfers to and from that module should take
11077 place as when the daemon was run as @code{root}.
11079 @item @code{gid} (default: @var{"rsyncd"})
11080 Group name or group ID that will be used when accessing the module.
11085 Furthermore, @code{(gnu services ssh)} provides the following services.
11089 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
11090 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
11091 [#:allow-empty-passwords? #f] [#:root-login? #f] @
11092 [#:syslog-output? #t] [#:x11-forwarding? #t] @
11093 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
11094 [#:public-key-authentication? #t] [#:initialize? #t]
11095 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
11096 @var{host-key} must designate a file containing the host key, and readable
11099 When @var{daemonic?} is true, @command{lshd} will detach from the
11100 controlling terminal and log its output to syslogd, unless one sets
11101 @var{syslog-output?} to false. Obviously, it also makes lsh-service
11102 depend on existence of syslogd service. When @var{pid-file?} is true,
11103 @command{lshd} writes its PID to the file called @var{pid-file}.
11105 When @var{initialize?} is true, automatically create the seed and host key
11106 upon service activation if they do not exist yet. This may take long and
11107 require interaction.
11109 When @var{initialize?} is false, it is up to the user to initialize the
11110 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
11111 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
11112 basics,,, lsh, LSH Manual}).
11114 When @var{interfaces} is empty, lshd listens for connections on all the
11115 network interfaces; otherwise, @var{interfaces} must be a list of host names
11118 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
11119 passwords, and @var{root-login?} specifies whether to accept log-ins as
11122 The other options should be self-descriptive.
11127 @deffn {Scheme Variable} openssh-service-type
11128 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
11129 shell daemon, @command{sshd}. Its value must be an
11130 @code{openssh-configuration} record as in this example:
11133 (service openssh-service-type
11134 (openssh-configuration
11135 (x11-forwarding? #t)
11136 (permit-root-login 'without-password)
11138 `(("alice" ,(local-file "alice.pub"))
11139 ("bob" ,(local-file "bob.pub"))))))
11142 See below for details about @code{openssh-configuration}.
11144 This service can be extended with extra authorized keys, as in this
11148 (service-extension openssh-service-type
11149 (const `(("charlie"
11150 ,(local-file "charlie.pub")))))
11154 @deftp {Data Type} openssh-configuration
11155 This is the configuration record for OpenSSH's @command{sshd}.
11158 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
11159 Name of the file where @command{sshd} writes its PID.
11161 @item @code{port-number} (default: @code{22})
11162 TCP port on which @command{sshd} listens for incoming connections.
11164 @item @code{permit-root-login} (default: @code{#f})
11165 This field determines whether and when to allow logins as root. If
11166 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
11167 If it's the symbol @code{'without-password}, then root logins are
11168 permitted but not with password-based authentication.
11170 @item @code{allow-empty-passwords?} (default: @code{#f})
11171 When true, users with empty passwords may log in. When false, they may
11174 @item @code{password-authentication?} (default: @code{#t})
11175 When true, users may log in with their password. When false, they have
11176 other authentication methods.
11178 @item @code{public-key-authentication?} (default: @code{#t})
11179 When true, users may log in using public key authentication. When
11180 false, users have to use other authentication method.
11182 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
11183 This is used only by protocol version 2.
11185 @item @code{x11-forwarding?} (default: @code{#f})
11186 When true, forwarding of X11 graphical client connections is
11187 enabled---in other words, @command{ssh} options @option{-X} and
11188 @option{-Y} will work.
11190 @item @code{challenge-response-authentication?} (default: @code{#f})
11191 Specifies whether challenge response authentication is allowed (e.g. via
11194 @item @code{use-pam?} (default: @code{#t})
11195 Enables the Pluggable Authentication Module interface. If set to
11196 @code{#t}, this will enable PAM authentication using
11197 @code{challenge-response-authentication?} and
11198 @code{password-authentication?}, in addition to PAM account and session
11199 module processing for all authentication types.
11201 Because PAM challenge response authentication usually serves an
11202 equivalent role to password authentication, you should disable either
11203 @code{challenge-response-authentication?} or
11204 @code{password-authentication?}.
11206 @item @code{print-last-log?} (default: @code{#t})
11207 Specifies whether @command{sshd} should print the date and time of the
11208 last user login when a user logs in interactively.
11210 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
11211 Configures external subsystems (e.g. file transfer daemon).
11213 This is a list of two-element lists, each of which containing the
11214 subsystem name and a command (with optional arguments) to execute upon
11217 The command @command{internal-sftp} implements an in-process SFTP
11218 server. Alternately, one can specify the @command{sftp-server} command:
11220 (service openssh-service-type
11221 (openssh-configuration
11223 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
11226 @item @code{accepted-environment} (default: @code{'()})
11227 List of strings describing which environment variables may be exported.
11229 Each string gets on its own line. See the @code{AcceptEnv} option in
11230 @code{man sshd_config}.
11232 This example allows ssh-clients to export the @code{COLORTERM} variable.
11233 It is set by terminal emulators, which support colors. You can use it in
11234 your shell's ressource file to enable colors for the prompt and commands
11235 if this variable is set.
11238 (service openssh-service-type
11239 (openssh-configuration
11240 (accepted-environment '("COLORTERM"))))
11243 @item @code{authorized-keys} (default: @code{'()})
11244 @cindex authorized keys, SSH
11245 @cindex SSH authorized keys
11246 This is the list of authorized keys. Each element of the list is a user
11247 name followed by one or more file-like objects that represent SSH public
11251 (openssh-configuration
11253 `(("rekado" ,(local-file "rekado.pub"))
11254 ("chris" ,(local-file "chris.pub"))
11255 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
11259 registers the specified public keys for user accounts @code{rekado},
11260 @code{chris}, and @code{root}.
11262 Additional authorized keys can be specified @i{via}
11263 @code{service-extension}.
11265 Note that this does @emph{not} interfere with the use of
11266 @file{~/.ssh/authorized_keys}.
11270 @deffn {Scheme Procedure} dropbear-service [@var{config}]
11271 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
11272 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
11275 For example, to specify a Dropbear service listening on port 1234, add
11276 this call to the operating system's @code{services} field:
11279 (dropbear-service (dropbear-configuration
11280 (port-number 1234)))
11284 @deftp {Data Type} dropbear-configuration
11285 This data type represents the configuration of a Dropbear SSH daemon.
11288 @item @code{dropbear} (default: @var{dropbear})
11289 The Dropbear package to use.
11291 @item @code{port-number} (default: 22)
11292 The TCP port where the daemon waits for incoming connections.
11294 @item @code{syslog-output?} (default: @code{#t})
11295 Whether to enable syslog output.
11297 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
11298 File name of the daemon's PID file.
11300 @item @code{root-login?} (default: @code{#f})
11301 Whether to allow @code{root} logins.
11303 @item @code{allow-empty-passwords?} (default: @code{#f})
11304 Whether to allow empty passwords.
11306 @item @code{password-authentication?} (default: @code{#t})
11307 Whether to enable password-based authentication.
11311 @defvr {Scheme Variable} %facebook-host-aliases
11312 This variable contains a string for use in @file{/etc/hosts}
11313 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
11314 line contains a entry that maps a known server name of the Facebook
11315 on-line service---e.g., @code{www.facebook.com}---to the local
11316 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
11318 This variable is typically used in the @code{hosts-file} field of an
11319 @code{operating-system} declaration (@pxref{operating-system Reference,
11320 @file{/etc/hosts}}):
11323 (use-modules (gnu) (guix))
11326 (host-name "mymachine")
11329 ;; Create a /etc/hosts file with aliases for "localhost"
11330 ;; and "mymachine", as well as for Facebook servers.
11331 (plain-file "hosts"
11332 (string-append (local-host-aliases host-name)
11333 %facebook-host-aliases))))
11336 This mechanism can prevent programs running locally, such as Web
11337 browsers, from accessing Facebook.
11340 The @code{(gnu services avahi)} provides the following definition.
11342 @deffn {Scheme Procedure} avahi-service [#:avahi @var{avahi}] @
11343 [#:host-name #f] [#:publish? #t] [#:ipv4? #t] @
11344 [#:ipv6? #t] [#:wide-area? #f] @
11345 [#:domains-to-browse '()] [#:debug? #f]
11346 Return a service that runs @command{avahi-daemon}, a system-wide
11347 mDNS/DNS-SD responder that allows for service discovery and
11348 "zero-configuration" host name lookups (see @uref{http://avahi.org/}), and
11349 extends the name service cache daemon (nscd) so that it can resolve
11350 @code{.local} host names using
11351 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. Additionally,
11352 add the @var{avahi} package to the system profile so that commands such as
11353 @command{avahi-browse} are directly usable.
11355 If @var{host-name} is different from @code{#f}, use that as the host name to
11356 publish for this machine; otherwise, use the machine's actual host name.
11358 When @var{publish?} is true, publishing of host names and services is allowed;
11359 in particular, avahi-daemon will publish the machine's host name and IP
11360 address via mDNS on the local network.
11362 When @var{wide-area?} is true, DNS-SD over unicast DNS is enabled.
11364 Boolean values @var{ipv4?} and @var{ipv6?} determine whether to use IPv4/IPv6
11368 @deffn {Scheme Variable} openvswitch-service-type
11369 This is the type of the @uref{http://www.openvswitch.org, Open vSwitch}
11370 service, whose value should be an @code{openvswitch-configuration}
11374 @deftp {Data Type} openvswitch-configuration
11375 Data type representing the configuration of Open vSwitch, a multilayer
11376 virtual switch which is designed to enable massive network automation
11377 through programmatic extension.
11380 @item @code{package} (default: @var{openvswitch})
11381 Package object of the Open vSwitch.
11387 @subsubsection X Window
11390 @cindex X Window System
11391 @cindex login manager
11392 Support for the X Window graphical display system---specifically
11393 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
11394 there is no @code{xorg-service} procedure. Instead, the X server is
11395 started by the @dfn{login manager}, by default SLiM.
11397 @cindex window manager
11398 To use X11, you must install at least one @dfn{window manager}---for
11399 example the @code{windowmaker} or @code{openbox} packages---preferably
11400 by adding it to the @code{packages} field of your operating system
11401 definition (@pxref{operating-system Reference, system-wide packages}).
11403 @defvr {Scheme Variable} slim-service-type
11404 This is the type for the SLiM graphical login manager for X11.
11406 @cindex session types (X11)
11407 @cindex X11 session types
11408 SLiM looks for @dfn{session types} described by the @file{.desktop} files in
11409 @file{/run/current-system/profile/share/xsessions} and allows users to
11410 choose a session from the log-in screen using @kbd{F1}. Packages such
11411 as @code{xfce}, @code{sawfish}, and @code{ratpoison} provide
11412 @file{.desktop} files; adding them to the system-wide set of packages
11413 automatically makes them available at the log-in screen.
11415 In addition, @file{~/.xsession} files are honored. When available,
11416 @file{~/.xsession} must be an executable that starts a window manager
11417 and/or other X clients.
11420 @deftp {Data Type} slim-configuration
11421 Data type representing the configuration of @code{slim-service-type}.
11424 @item @code{allow-empty-passwords?} (default: @code{#t})
11425 Whether to allow logins with empty passwords.
11427 @item @code{auto-login?} (default: @code{#f})
11428 @itemx @code{default-user} (default: @code{""})
11429 When @code{auto-login?} is false, SLiM presents a log-in screen.
11431 When @code{auto-login?} is true, SLiM logs in directly as
11432 @code{default-user}.
11434 @item @code{theme} (default: @code{%default-slim-theme})
11435 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
11436 The graphical theme to use and its name.
11438 @item @code{auto-login-session} (default: @code{#f})
11439 If true, this must be the name of the executable to start as the default
11440 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
11442 If false, a session described by one of the available @file{.desktop}
11443 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
11447 You must install at least one window manager in the system profile or in
11448 your user profile. Failing to do that, if @code{auto-login-session} is
11449 false, you will be unable to log in.
11452 @item @code{startx} (default: @code{(xorg-start-command)})
11453 The command used to start the X11 graphical server.
11455 @item @code{xauth} (default: @code{xauth})
11456 The XAuth package to use.
11458 @item @code{shepherd} (default: @code{shepherd})
11459 The Shepherd package used when invoking @command{halt} and
11462 @item @code{sessreg} (default: @code{sessreg})
11463 The sessreg package used in order to register the session.
11465 @item @code{slim} (default: @code{slim})
11466 The SLiM package to use.
11470 @defvr {Scheme Variable} %default-theme
11471 @defvrx {Scheme Variable} %default-theme-name
11472 The default SLiM theme and its name.
11476 @deftp {Data Type} sddm-configuration
11477 This is the data type representing the sddm service configuration.
11480 @item @code{display-server} (default: "x11")
11481 Select display server to use for the greeter. Valid values are "x11"
11484 @item @code{numlock} (default: "on")
11485 Valid values are "on", "off" or "none".
11487 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
11488 Command to run when halting.
11490 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
11491 Command to run when rebooting.
11493 @item @code{theme} (default "maldives")
11494 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
11496 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
11497 Directory to look for themes.
11499 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
11500 Directory to look for faces.
11502 @item @code{default-path} (default "/run/current-system/profile/bin")
11503 Default PATH to use.
11505 @item @code{minimum-uid} (default 1000)
11506 Minimum UID to display in SDDM.
11508 @item @code{maximum-uid} (default 2000)
11509 Maximum UID to display in SDDM
11511 @item @code{remember-last-user?} (default #t)
11512 Remember last user.
11514 @item @code{remember-last-session?} (default #t)
11515 Remember last session.
11517 @item @code{hide-users} (default "")
11518 Usernames to hide from SDDM greeter.
11520 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
11521 Users with shells listed will be hidden from the SDDM greeter.
11523 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
11524 Script to run before starting a wayland session.
11526 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
11527 Directory to look for desktop files starting wayland sessions.
11529 @item @code{xorg-server-path} (default @code{xorg-start-command})
11530 Path to xorg-server.
11532 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
11535 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
11538 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
11539 Script to run after starting xorg-server.
11541 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
11542 Script to run before stopping xorg-server.
11544 @item @code{xsession-command} (default: @code{xinitr })
11545 Script to run before starting a X session.
11547 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
11548 Directory to look for desktop files starting X sessions.
11550 @item @code{minimum-vt} (default: 7)
11553 @item @code{xserver-arguments} (default "-nolisten tcp")
11554 Arguments to pass to xorg-server.
11556 @item @code{auto-login-user} (default "")
11557 User to use for auto-login.
11559 @item @code{auto-login-session} (default "")
11560 Desktop file to use for auto-login.
11562 @item @code{relogin?} (default #f)
11563 Relogin after logout.
11568 @cindex login manager
11570 @deffn {Scheme Procedure} sddm-service config
11571 Return a service that spawns the SDDM graphical login manager for config of
11572 type @code{<sddm-configuration>}.
11575 (sddm-service (sddm-configuration
11576 (auto-login-user "Alice")
11577 (auto-login-session "xfce.desktop")))
11581 @deffn {Scheme Procedure} xorg-start-command [#:guile] @
11582 [#:modules %default-xorg-modules] @
11583 [#:fonts %default-xorg-fonts] @
11584 [#:configuration-file (xorg-configuration-file @dots{})] @
11585 [#:xorg-server @var{xorg-server}]
11586 Return a @code{startx} script in which @var{modules}, a list of X module
11587 packages, and @var{fonts}, a list of X font directories, are available. See
11588 @code{xorg-wrapper} for more details on the arguments. The result should be
11589 used in place of @code{startx}.
11591 Usually the X server is started by a login manager.
11594 @deffn {Scheme Procedure} xorg-configuration-file @
11595 [#:modules %default-xorg-modules] @
11596 [#:fonts %default-xorg-fonts] @
11597 [#:drivers '()] [#:resolutions '()] [#:extra-config '()]
11598 Return a configuration file for the Xorg server containing search paths for
11599 all the common drivers.
11601 @var{modules} must be a list of @dfn{module packages} loaded by the Xorg
11602 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
11603 @var{fonts} must be a list of font directories to add to the server's
11606 @var{drivers} must be either the empty list, in which case Xorg chooses a
11607 graphics driver automatically, or a list of driver names that will be tried in
11608 this order---e.g., @code{("modesetting" "vesa")}.
11610 Likewise, when @var{resolutions} is the empty list, Xorg chooses an
11611 appropriate screen resolution; otherwise, it must be a list of
11612 resolutions---e.g., @code{((1024 768) (640 480))}.
11614 Last, @var{extra-config} is a list of strings or objects appended to the
11615 configuration file. It is used to pass extra text to be
11616 added verbatim to the configuration file.
11619 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
11620 Add @var{package}, a package for a screen locker or screen saver whose
11621 command is @var{program}, to the set of setuid programs and add a PAM entry
11622 for it. For example:
11625 (screen-locker-service xlockmore "xlock")
11628 makes the good ol' XlockMore usable.
11632 @node Printing Services
11633 @subsubsection Printing Services
11635 @cindex printer support with CUPS
11636 The @code{(gnu services cups)} module provides a Guix service definition
11637 for the CUPS printing service. To add printer support to a GuixSD
11638 system, add a @code{cups-service} to the operating system definition:
11640 @deffn {Scheme Variable} cups-service-type
11641 The service type for the CUPS print server. Its value should be a valid
11642 CUPS configuration (see below). To use the default settings, simply
11645 (service cups-service-type)
11649 The CUPS configuration controls the basic things about your CUPS
11650 installation: what interfaces it listens on, what to do if a print job
11651 fails, how much logging to do, and so on. To actually add a printer,
11652 you have to visit the @url{http://localhost:631} URL, or use a tool such
11653 as GNOME's printer configuration services. By default, configuring a
11654 CUPS service will generate a self-signed certificate if needed, for
11655 secure connections to the print server.
11657 Suppose you want to enable the Web interface of CUPS and also add
11658 support for Epson printers @i{via} the @code{escpr} package and for HP
11659 printers @i{via} the @code{hplip} package. You can do that directly,
11660 like this (you need to use the @code{(gnu packages cups)} module):
11663 (service cups-service-type
11664 (cups-configuration
11665 (web-interface? #t)
11667 (list cups-filters escpr hplip))))
11670 The available configuration parameters follow. Each parameter
11671 definition is preceded by its type; for example, @samp{string-list foo}
11672 indicates that the @code{foo} parameter should be specified as a list of
11673 strings. There is also a way to specify the configuration as a string,
11674 if you have an old @code{cupsd.conf} file that you want to port over
11675 from some other system; see the end for more details.
11677 @c The following documentation was initially generated by
11678 @c (generate-documentation) in (gnu services cups). Manually maintained
11679 @c documentation is better, so we shouldn't hesitate to edit below as
11680 @c needed. However if the change you want to make to this documentation
11681 @c can be done in an automated way, it's probably easier to change
11682 @c (generate-documentation) than to make it below and have to deal with
11683 @c the churn as CUPS updates.
11686 Available @code{cups-configuration} fields are:
11688 @deftypevr {@code{cups-configuration} parameter} package cups
11692 @deftypevr {@code{cups-configuration} parameter} package-list extensions
11693 Drivers and other extensions to the CUPS package.
11696 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
11697 Configuration of where to write logs, what directories to use for print
11698 spools, and related privileged configuration parameters.
11700 Available @code{files-configuration} fields are:
11702 @deftypevr {@code{files-configuration} parameter} log-location access-log
11703 Defines the access log filename. Specifying a blank filename disables
11704 access log generation. The value @code{stderr} causes log entries to be
11705 sent to the standard error file when the scheduler is running in the
11706 foreground, or to the system log daemon when run in the background. The
11707 value @code{syslog} causes log entries to be sent to the system log
11708 daemon. The server name may be included in filenames using the string
11709 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
11711 Defaults to @samp{"/var/log/cups/access_log"}.
11714 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
11715 Where CUPS should cache data.
11717 Defaults to @samp{"/var/cache/cups"}.
11720 @deftypevr {@code{files-configuration} parameter} string config-file-perm
11721 Specifies the permissions for all configuration files that the scheduler
11724 Note that the permissions for the printers.conf file are currently
11725 masked to only allow access from the scheduler user (typically root).
11726 This is done because printer device URIs sometimes contain sensitive
11727 authentication information that should not be generally known on the
11728 system. There is no way to disable this security feature.
11730 Defaults to @samp{"0640"}.
11733 @deftypevr {@code{files-configuration} parameter} log-location error-log
11734 Defines the error log filename. Specifying a blank filename disables
11735 access log generation. The value @code{stderr} causes log entries to be
11736 sent to the standard error file when the scheduler is running in the
11737 foreground, or to the system log daemon when run in the background. The
11738 value @code{syslog} causes log entries to be sent to the system log
11739 daemon. The server name may be included in filenames using the string
11740 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
11742 Defaults to @samp{"/var/log/cups/error_log"}.
11745 @deftypevr {@code{files-configuration} parameter} string fatal-errors
11746 Specifies which errors are fatal, causing the scheduler to exit. The
11751 No errors are fatal.
11754 All of the errors below are fatal.
11757 Browsing initialization errors are fatal, for example failed connections
11758 to the DNS-SD daemon.
11761 Configuration file syntax errors are fatal.
11764 Listen or Port errors are fatal, except for IPv6 failures on the
11765 loopback or @code{any} addresses.
11768 Log file creation or write errors are fatal.
11771 Bad startup file permissions are fatal, for example shared TLS
11772 certificate and key files with world-read permissions.
11775 Defaults to @samp{"all -browse"}.
11778 @deftypevr {@code{files-configuration} parameter} boolean file-device?
11779 Specifies whether the file pseudo-device can be used for new printer
11780 queues. The URI @uref{file:///dev/null} is always allowed.
11782 Defaults to @samp{#f}.
11785 @deftypevr {@code{files-configuration} parameter} string group
11786 Specifies the group name or ID that will be used when executing external
11789 Defaults to @samp{"lp"}.
11792 @deftypevr {@code{files-configuration} parameter} string log-file-perm
11793 Specifies the permissions for all log files that the scheduler writes.
11795 Defaults to @samp{"0644"}.
11798 @deftypevr {@code{files-configuration} parameter} log-location page-log
11799 Defines the page log filename. Specifying a blank filename disables
11800 access log generation. The value @code{stderr} causes log entries to be
11801 sent to the standard error file when the scheduler is running in the
11802 foreground, or to the system log daemon when run in the background. The
11803 value @code{syslog} causes log entries to be sent to the system log
11804 daemon. The server name may be included in filenames using the string
11805 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
11807 Defaults to @samp{"/var/log/cups/page_log"}.
11810 @deftypevr {@code{files-configuration} parameter} string remote-root
11811 Specifies the username that is associated with unauthenticated accesses
11812 by clients claiming to be the root user. The default is @code{remroot}.
11814 Defaults to @samp{"remroot"}.
11817 @deftypevr {@code{files-configuration} parameter} file-name request-root
11818 Specifies the directory that contains print jobs and other HTTP request
11821 Defaults to @samp{"/var/spool/cups"}.
11824 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
11825 Specifies the level of security sandboxing that is applied to print
11826 filters, backends, and other child processes of the scheduler; either
11827 @code{relaxed} or @code{strict}. This directive is currently only
11828 used/supported on macOS.
11830 Defaults to @samp{strict}.
11833 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
11834 Specifies the location of TLS certificates and private keys. CUPS will
11835 look for public and private keys in this directory: a @code{.crt} files
11836 for PEM-encoded certificates and corresponding @code{.key} files for
11837 PEM-encoded private keys.
11839 Defaults to @samp{"/etc/cups/ssl"}.
11842 @deftypevr {@code{files-configuration} parameter} file-name server-root
11843 Specifies the directory containing the server configuration files.
11845 Defaults to @samp{"/etc/cups"}.
11848 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
11849 Specifies whether the scheduler calls fsync(2) after writing
11850 configuration or state files.
11852 Defaults to @samp{#f}.
11855 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
11856 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
11859 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
11860 Specifies the directory where temporary files are stored.
11862 Defaults to @samp{"/var/spool/cups/tmp"}.
11865 @deftypevr {@code{files-configuration} parameter} string user
11866 Specifies the user name or ID that is used when running external
11869 Defaults to @samp{"lp"}.
11873 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
11874 Specifies the logging level for the AccessLog file. The @code{config}
11875 level logs when printers and classes are added, deleted, or modified and
11876 when configuration files are accessed or updated. The @code{actions}
11877 level logs when print jobs are submitted, held, released, modified, or
11878 canceled, and any of the conditions for @code{config}. The @code{all}
11879 level logs all requests.
11881 Defaults to @samp{actions}.
11884 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
11885 Specifies whether to purge job history data automatically when it is no
11886 longer required for quotas.
11888 Defaults to @samp{#f}.
11891 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
11892 Specifies which protocols to use for local printer sharing.
11894 Defaults to @samp{dnssd}.
11897 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
11898 Specifies whether the CUPS web interface is advertised.
11900 Defaults to @samp{#f}.
11903 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
11904 Specifies whether shared printers are advertised.
11906 Defaults to @samp{#f}.
11909 @deftypevr {@code{cups-configuration} parameter} string classification
11910 Specifies the security classification of the server. Any valid banner
11911 name can be used, including "classified", "confidential", "secret",
11912 "topsecret", and "unclassified", or the banner can be omitted to disable
11913 secure printing functions.
11915 Defaults to @samp{""}.
11918 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
11919 Specifies whether users may override the classification (cover page) of
11920 individual print jobs using the @code{job-sheets} option.
11922 Defaults to @samp{#f}.
11925 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
11926 Specifies the default type of authentication to use.
11928 Defaults to @samp{Basic}.
11931 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
11932 Specifies whether encryption will be used for authenticated requests.
11934 Defaults to @samp{Required}.
11937 @deftypevr {@code{cups-configuration} parameter} string default-language
11938 Specifies the default language to use for text and web content.
11940 Defaults to @samp{"en"}.
11943 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
11944 Specifies the default paper size for new print queues. @samp{"Auto"}
11945 uses a locale-specific default, while @samp{"None"} specifies there is
11946 no default paper size. Specific size names are typically
11947 @samp{"Letter"} or @samp{"A4"}.
11949 Defaults to @samp{"Auto"}.
11952 @deftypevr {@code{cups-configuration} parameter} string default-policy
11953 Specifies the default access policy to use.
11955 Defaults to @samp{"default"}.
11958 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
11959 Specifies whether local printers are shared by default.
11961 Defaults to @samp{#t}.
11964 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
11965 Specifies the delay for updating of configuration and state files, in
11966 seconds. A value of 0 causes the update to happen as soon as possible,
11967 typically within a few milliseconds.
11969 Defaults to @samp{30}.
11972 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
11973 Specifies what to do when an error occurs. Possible values are
11974 @code{abort-job}, which will discard the failed print job;
11975 @code{retry-job}, which will retry the job at a later time;
11976 @code{retry-this-job}, which retries the failed job immediately; and
11977 @code{stop-printer}, which stops the printer.
11979 Defaults to @samp{stop-printer}.
11982 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
11983 Specifies the maximum cost of filters that are run concurrently, which
11984 can be used to minimize disk, memory, and CPU resource problems. A
11985 limit of 0 disables filter limiting. An average print to a
11986 non-PostScript printer needs a filter limit of about 200. A PostScript
11987 printer needs about half that (100). Setting the limit below these
11988 thresholds will effectively limit the scheduler to printing a single job
11991 Defaults to @samp{0}.
11994 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
11995 Specifies the scheduling priority of filters that are run to print a
11996 job. The nice value ranges from 0, the highest priority, to 19, the
11999 Defaults to @samp{0}.
12002 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
12003 Specifies whether to do reverse lookups on connecting clients. The
12004 @code{double} setting causes @code{cupsd} to verify that the hostname
12005 resolved from the address matches one of the addresses returned for that
12006 hostname. Double lookups also prevent clients with unregistered
12007 addresses from connecting to your server. Only set this option to
12008 @code{#t} or @code{double} if absolutely required.
12010 Defaults to @samp{#f}.
12013 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
12014 Specifies the number of seconds to wait before killing the filters and
12015 backend associated with a canceled or held job.
12017 Defaults to @samp{30}.
12020 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
12021 Specifies the interval between retries of jobs in seconds. This is
12022 typically used for fax queues but can also be used with normal print
12023 queues whose error policy is @code{retry-job} or
12024 @code{retry-current-job}.
12026 Defaults to @samp{30}.
12029 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
12030 Specifies the number of retries that are done for jobs. This is
12031 typically used for fax queues but can also be used with normal print
12032 queues whose error policy is @code{retry-job} or
12033 @code{retry-current-job}.
12035 Defaults to @samp{5}.
12038 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
12039 Specifies whether to support HTTP keep-alive connections.
12041 Defaults to @samp{#t}.
12044 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
12045 Specifies how long an idle client connection remains open, in seconds.
12047 Defaults to @samp{30}.
12050 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
12051 Specifies the maximum size of print files, IPP requests, and HTML form
12052 data. A limit of 0 disables the limit check.
12054 Defaults to @samp{0}.
12057 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
12058 Listens on the specified interfaces for connections. Valid values are
12059 of the form @var{address}:@var{port}, where @var{address} is either an
12060 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
12061 indicate all addresses. Values can also be file names of local UNIX
12062 domain sockets. The Listen directive is similar to the Port directive
12063 but allows you to restrict access to specific interfaces or networks.
12066 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
12067 Specifies the number of pending connections that will be allowed. This
12068 normally only affects very busy servers that have reached the MaxClients
12069 limit, but can also be triggered by large numbers of simultaneous
12070 connections. When the limit is reached, the operating system will
12071 refuse additional connections until the scheduler can accept the pending
12074 Defaults to @samp{128}.
12077 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
12078 Specifies a set of additional access controls.
12080 Available @code{location-access-controls} fields are:
12082 @deftypevr {@code{location-access-controls} parameter} file-name path
12083 Specifies the URI path to which the access control applies.
12086 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
12087 Access controls for all access to this path, in the same format as the
12088 @code{access-controls} of @code{operation-access-control}.
12090 Defaults to @samp{()}.
12093 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
12094 Access controls for method-specific access to this path.
12096 Defaults to @samp{()}.
12098 Available @code{method-access-controls} fields are:
12100 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
12101 If @code{#t}, apply access controls to all methods except the listed
12102 methods. Otherwise apply to only the listed methods.
12104 Defaults to @samp{#f}.
12107 @deftypevr {@code{method-access-controls} parameter} method-list methods
12108 Methods to which this access control applies.
12110 Defaults to @samp{()}.
12113 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
12114 Access control directives, as a list of strings. Each string should be
12115 one directive, such as "Order allow,deny".
12117 Defaults to @samp{()}.
12122 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
12123 Specifies the number of debugging messages that are retained for logging
12124 if an error occurs in a print job. Debug messages are logged regardless
12125 of the LogLevel setting.
12127 Defaults to @samp{100}.
12130 @deftypevr {@code{cups-configuration} parameter} log-level log-level
12131 Specifies the level of logging for the ErrorLog file. The value
12132 @code{none} stops all logging while @code{debug2} logs everything.
12134 Defaults to @samp{info}.
12137 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
12138 Specifies the format of the date and time in the log files. The value
12139 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
12141 Defaults to @samp{standard}.
12144 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
12145 Specifies the maximum number of simultaneous clients that are allowed by
12148 Defaults to @samp{100}.
12151 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
12152 Specifies the maximum number of simultaneous clients that are allowed
12153 from a single address.
12155 Defaults to @samp{100}.
12158 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
12159 Specifies the maximum number of copies that a user can print of each
12162 Defaults to @samp{9999}.
12165 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
12166 Specifies the maximum time a job may remain in the @code{indefinite}
12167 hold state before it is canceled. A value of 0 disables cancellation of
12170 Defaults to @samp{0}.
12173 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
12174 Specifies the maximum number of simultaneous jobs that are allowed. Set
12175 to 0 to allow an unlimited number of jobs.
12177 Defaults to @samp{500}.
12180 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
12181 Specifies the maximum number of simultaneous jobs that are allowed per
12182 printer. A value of 0 allows up to MaxJobs jobs per printer.
12184 Defaults to @samp{0}.
12187 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
12188 Specifies the maximum number of simultaneous jobs that are allowed per
12189 user. A value of 0 allows up to MaxJobs jobs per user.
12191 Defaults to @samp{0}.
12194 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
12195 Specifies the maximum time a job may take to print before it is
12196 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
12198 Defaults to @samp{10800}.
12201 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
12202 Specifies the maximum size of the log files before they are rotated, in
12203 bytes. The value 0 disables log rotation.
12205 Defaults to @samp{1048576}.
12208 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
12209 Specifies the maximum amount of time to allow between files in a
12210 multiple file print job, in seconds.
12212 Defaults to @samp{300}.
12215 @deftypevr {@code{cups-configuration} parameter} string page-log-format
12216 Specifies the format of PageLog lines. Sequences beginning with percent
12217 (@samp{%}) characters are replaced with the corresponding information,
12218 while all other characters are copied literally. The following percent
12219 sequences are recognized:
12223 insert a single percent character
12226 insert the value of the specified IPP attribute
12229 insert the number of copies for the current page
12232 insert the current page number
12235 insert the current date and time in common log format
12241 insert the printer name
12244 insert the username
12247 A value of the empty string disables page logging. The string @code{%p
12248 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
12249 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
12252 Defaults to @samp{""}.
12255 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
12256 Passes the specified environment variable(s) to child processes; a list
12259 Defaults to @samp{()}.
12262 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
12263 Specifies named access control policies.
12265 Available @code{policy-configuration} fields are:
12267 @deftypevr {@code{policy-configuration} parameter} string name
12268 Name of the policy.
12271 @deftypevr {@code{policy-configuration} parameter} string job-private-access
12272 Specifies an access list for a job's private values. @code{@@ACL} maps
12273 to the printer's requesting-user-name-allowed or
12274 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
12275 owner. @code{@@SYSTEM} maps to the groups listed for the
12276 @code{system-group} field of the @code{files-config} configuration,
12277 which is reified into the @code{cups-files.conf(5)} file. Other
12278 possible elements of the access list include specific user names, and
12279 @code{@@@var{group}} to indicate members of a specific group. The
12280 access list may also be simply @code{all} or @code{default}.
12282 Defaults to @samp{"@@OWNER @@SYSTEM"}.
12285 @deftypevr {@code{policy-configuration} parameter} string job-private-values
12286 Specifies the list of job values to make private, or @code{all},
12287 @code{default}, or @code{none}.
12289 Defaults to @samp{"job-name job-originating-host-name
12290 job-originating-user-name phone"}.
12293 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
12294 Specifies an access list for a subscription's private values.
12295 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
12296 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
12297 owner. @code{@@SYSTEM} maps to the groups listed for the
12298 @code{system-group} field of the @code{files-config} configuration,
12299 which is reified into the @code{cups-files.conf(5)} file. Other
12300 possible elements of the access list include specific user names, and
12301 @code{@@@var{group}} to indicate members of a specific group. The
12302 access list may also be simply @code{all} or @code{default}.
12304 Defaults to @samp{"@@OWNER @@SYSTEM"}.
12307 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
12308 Specifies the list of job values to make private, or @code{all},
12309 @code{default}, or @code{none}.
12311 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
12312 notify-subscriber-user-name notify-user-data"}.
12315 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
12316 Access control by IPP operation.
12318 Defaults to @samp{()}.
12322 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
12323 Specifies whether job files (documents) are preserved after a job is
12324 printed. If a numeric value is specified, job files are preserved for
12325 the indicated number of seconds after printing. Otherwise a boolean
12326 value applies indefinitely.
12328 Defaults to @samp{86400}.
12331 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
12332 Specifies whether the job history is preserved after a job is printed.
12333 If a numeric value is specified, the job history is preserved for the
12334 indicated number of seconds after printing. If @code{#t}, the job
12335 history is preserved until the MaxJobs limit is reached.
12337 Defaults to @samp{#t}.
12340 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
12341 Specifies the amount of time to wait for job completion before
12342 restarting the scheduler.
12344 Defaults to @samp{30}.
12347 @deftypevr {@code{cups-configuration} parameter} string rip-cache
12348 Specifies the maximum amount of memory to use when converting documents
12349 into bitmaps for a printer.
12351 Defaults to @samp{"128m"}.
12354 @deftypevr {@code{cups-configuration} parameter} string server-admin
12355 Specifies the email address of the server administrator.
12357 Defaults to @samp{"root@@localhost.localdomain"}.
12360 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
12361 The ServerAlias directive is used for HTTP Host header validation when
12362 clients connect to the scheduler from external interfaces. Using the
12363 special name @code{*} can expose your system to known browser-based DNS
12364 rebinding attacks, even when accessing sites through a firewall. If the
12365 auto-discovery of alternate names does not work, we recommend listing
12366 each alternate name with a ServerAlias directive instead of using
12369 Defaults to @samp{*}.
12372 @deftypevr {@code{cups-configuration} parameter} string server-name
12373 Specifies the fully-qualified host name of the server.
12375 Defaults to @samp{"localhost"}.
12378 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
12379 Specifies what information is included in the Server header of HTTP
12380 responses. @code{None} disables the Server header. @code{ProductOnly}
12381 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
12382 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
12383 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
12384 the output of the @code{uname} command. @code{Full} reports @code{CUPS
12385 2.0.0 (@var{uname}) IPP/2.0}.
12387 Defaults to @samp{Minimal}.
12390 @deftypevr {@code{cups-configuration} parameter} string set-env
12391 Set the specified environment variable to be passed to child processes.
12393 Defaults to @samp{"variable value"}.
12396 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
12397 Listens on the specified interfaces for encrypted connections. Valid
12398 values are of the form @var{address}:@var{port}, where @var{address} is
12399 either an IPv6 address enclosed in brackets, an IPv4 address, or
12400 @code{*} to indicate all addresses.
12402 Defaults to @samp{()}.
12405 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
12406 Sets encryption options. By default, CUPS only supports encryption
12407 using TLS v1.0 or higher using known secure cipher suites. The
12408 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
12409 required for some older clients that do not implement newer ones. The
12410 @code{AllowSSL3} option enables SSL v3.0, which is required for some
12411 older clients that do not support TLS v1.0.
12413 Defaults to @samp{()}.
12416 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
12417 Specifies whether the scheduler requires clients to strictly adhere to
12418 the IPP specifications.
12420 Defaults to @samp{#f}.
12423 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
12424 Specifies the HTTP request timeout, in seconds.
12426 Defaults to @samp{300}.
12430 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
12431 Specifies whether the web interface is enabled.
12433 Defaults to @samp{#f}.
12436 At this point you're probably thinking ``oh dear, Guix manual, I like
12437 you but you can stop already with the configuration options''. Indeed.
12438 However, one more point: it could be that you have an existing
12439 @code{cupsd.conf} that you want to use. In that case, you can pass an
12440 @code{opaque-cups-configuration} as the configuration of a
12441 @code{cups-service-type}.
12443 Available @code{opaque-cups-configuration} fields are:
12445 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
12449 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
12450 The contents of the @code{cupsd.conf}, as a string.
12453 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
12454 The contents of the @code{cups-files.conf} file, as a string.
12457 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
12458 strings of the same name, you could instantiate a CUPS service like
12462 (service cups-service-type
12463 (opaque-cups-configuration
12464 (cupsd.conf cupsd.conf)
12465 (cups-files.conf cups-files.conf)))
12469 @node Desktop Services
12470 @subsubsection Desktop Services
12472 The @code{(gnu services desktop)} module provides services that are
12473 usually useful in the context of a ``desktop'' setup---that is, on a
12474 machine running a graphical display server, possibly with graphical user
12475 interfaces, etc. It also defines services that provide specific desktop
12476 environments like GNOME, XFCE or MATE.
12478 To simplify things, the module defines a variable containing the set of
12479 services that users typically expect on a machine with a graphical
12480 environment and networking:
12482 @defvr {Scheme Variable} %desktop-services
12483 This is a list of services that builds upon @var{%base-services} and
12484 adds or adjusts services for a typical ``desktop'' setup.
12486 In particular, it adds a graphical login manager (@pxref{X Window,
12487 @code{slim-service}}), screen lockers, a network management tool
12488 (@pxref{Networking Services, @code{network-manager-service-type}}), energy and color
12489 management services, the @code{elogind} login and seat manager, the
12490 Polkit privilege service, the GeoClue location service, the
12491 AccountsService daemon that allows authorized users change system
12492 passwords, an NTP client (@pxref{Networking Services}), the Avahi
12493 daemon, and has the name service switch service configured to be able to
12494 use @code{nss-mdns} (@pxref{Name Service Switch, mDNS}).
12497 The @var{%desktop-services} variable can be used as the @code{services}
12498 field of an @code{operating-system} declaration (@pxref{operating-system
12499 Reference, @code{services}}).
12501 Additionally, the @code{gnome-desktop-service},
12502 @code{xfce-desktop-service} and @code{mate-desktop-service}
12503 procedures can add GNOME, XFCE and/or MATE to a system.
12504 To ``add GNOME'' means that system-level services like the
12505 backlight adjustment helpers and the power management utilities are
12506 added to the system, extending @code{polkit} and @code{dbus}
12507 appropriately, allowing GNOME to operate with elevated privileges on a
12508 limited number of special-purpose system interfaces. Additionally,
12509 adding a service made by @code{gnome-desktop-service} adds the GNOME
12510 metapackage to the system profile. Likewise, adding the XFCE service
12511 not only adds the @code{xfce} metapackage to the system profile, but it
12512 also gives the Thunar file manager the ability to open a ``root-mode''
12513 file management window, if the user authenticates using the
12514 administrator's password via the standard polkit graphical interface.
12515 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
12516 appropriately, allowing MATE to operate with elevated privileges on a
12517 limited number of special-purpose system interfaces. Additionally,
12518 adding a service made by @code{mate-desktop-service} adds the MATE
12519 metapackage to the system profile.
12521 The desktop environments in Guix use the Xorg display server by
12522 default. If you'd like to use the newer display server protocol
12523 called Wayland, you need to use the @code{sddm-service} instead of the
12524 @code{slim-service} for the graphical login manager. You should then
12525 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
12526 also try starting GNOME on Wayland manually from a TTY with the
12527 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
12528 gnome-session``. Currently only GNOME has support for Wayland.
12530 @deffn {Scheme Procedure} gnome-desktop-service
12531 Return a service that adds the @code{gnome} package to the system
12532 profile, and extends polkit with the actions from
12533 @code{gnome-settings-daemon}.
12536 @deffn {Scheme Procedure} xfce-desktop-service
12537 Return a service that adds the @code{xfce} package to the system profile,
12538 and extends polkit with the ability for @code{thunar} to manipulate the
12539 file system as root from within a user session, after the user has
12540 authenticated with the administrator's password.
12543 @deffn {Scheme Procedure} mate-desktop-service
12544 Return a service that adds the @code{mate} package to the system
12545 profile, and extends polkit with the actions from
12546 @code{mate-settings-daemon}.
12549 Because the GNOME, XFCE and MATE desktop services pull in so many packages,
12550 the default @code{%desktop-services} variable doesn't include either of
12551 them by default. To add GNOME, XFCE or MATE, just @code{cons} them onto
12552 @code{%desktop-services} in the @code{services} field of your
12553 @code{operating-system}:
12556 (use-modules (gnu))
12557 (use-service-modules desktop)
12560 ;; cons* adds items to the list given as its last argument.
12561 (services (cons* (gnome-desktop-service)
12562 (xfce-desktop-service)
12563 %desktop-services))
12567 These desktop environments will then be available as options in the
12568 graphical login window.
12570 The actual service definitions included in @code{%desktop-services} and
12571 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
12572 are described below.
12574 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
12575 Return a service that runs the ``system bus'', using @var{dbus}, with
12576 support for @var{services}.
12578 @uref{http://dbus.freedesktop.org/, D-Bus} is an inter-process communication
12579 facility. Its system bus is used to allow system services to communicate
12580 and to be notified of system-wide events.
12582 @var{services} must be a list of packages that provide an
12583 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
12584 and policy files. For example, to allow avahi-daemon to use the system bus,
12585 @var{services} must be equal to @code{(list avahi)}.
12588 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
12589 Return a service that runs the @code{elogind} login and
12590 seat management daemon. @uref{https://github.com/elogind/elogind,
12591 Elogind} exposes a D-Bus interface that can be used to know which users
12592 are logged in, know what kind of sessions they have open, suspend the
12593 system, inhibit system suspend, reboot the system, and other tasks.
12595 Elogind handles most system-level power events for a computer, for
12596 example suspending the system when a lid is closed, or shutting it down
12597 when the power button is pressed.
12599 The @var{config} keyword argument specifies the configuration for
12600 elogind, and should be the result of an @code{(elogind-configuration
12601 (@var{parameter} @var{value})...)} invocation. Available parameters and
12602 their default values are:
12605 @item kill-user-processes?
12607 @item kill-only-users
12609 @item kill-exclude-users
12611 @item inhibit-delay-max-seconds
12613 @item handle-power-key
12615 @item handle-suspend-key
12617 @item handle-hibernate-key
12619 @item handle-lid-switch
12621 @item handle-lid-switch-docked
12623 @item power-key-ignore-inhibited?
12625 @item suspend-key-ignore-inhibited?
12627 @item hibernate-key-ignore-inhibited?
12629 @item lid-switch-ignore-inhibited?
12631 @item holdoff-timeout-seconds
12635 @item idle-action-seconds
12637 @item runtime-directory-size-percent
12639 @item runtime-directory-size
12643 @item suspend-state
12644 @code{("mem" "standby" "freeze")}
12647 @item hibernate-state
12649 @item hibernate-mode
12650 @code{("platform" "shutdown")}
12651 @item hybrid-sleep-state
12653 @item hybrid-sleep-mode
12654 @code{("suspend" "platform" "shutdown")}
12658 @deffn {Scheme Procedure} accountsservice-service @
12659 [#:accountsservice @var{accountsservice}]
12660 Return a service that runs AccountsService, a system service that can
12661 list available accounts, change their passwords, and so on.
12662 AccountsService integrates with PolicyKit to enable unprivileged users
12663 to acquire the capability to modify their system configuration.
12664 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
12665 accountsservice web site} for more information.
12667 The @var{accountsservice} keyword argument is the @code{accountsservice}
12668 package to expose as a service.
12671 @deffn {Scheme Procedure} polkit-service @
12672 [#:polkit @var{polkit}]
12673 Return a service that runs the
12674 @uref{http://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
12675 management service}, which allows system administrators to grant access to
12676 privileged operations in a structured way. By querying the Polkit service, a
12677 privileged system component can know when it should grant additional
12678 capabilities to ordinary users. For example, an ordinary user can be granted
12679 the capability to suspend the system if the user is logged in locally.
12682 @deffn {Scheme Procedure} upower-service [#:upower @var{upower}] @
12683 [#:watts-up-pro? #f] @
12684 [#:poll-batteries? #t] @
12685 [#:ignore-lid? #f] @
12686 [#:use-percentage-for-policy? #f] @
12687 [#:percentage-low 10] @
12688 [#:percentage-critical 3] @
12689 [#:percentage-action 2] @
12690 [#:time-low 1200] @
12691 [#:time-critical 300] @
12692 [#:time-action 120] @
12693 [#:critical-power-action 'hybrid-sleep]
12694 Return a service that runs @uref{http://upower.freedesktop.org/,
12695 @command{upowerd}}, a system-wide monitor for power consumption and battery
12696 levels, with the given configuration settings. It implements the
12697 @code{org.freedesktop.UPower} D-Bus interface, and is notably used by
12701 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
12702 Return a service for @uref{http://udisks.freedesktop.org/docs/latest/,
12703 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
12704 notifications and ways to mount/unmount disks. Programs that talk to UDisks
12705 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
12708 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
12709 Return a service that runs @command{colord}, a system service with a D-Bus
12710 interface to manage the color profiles of input and output devices such as
12711 screens and scanners. It is notably used by the GNOME Color Manager graphical
12712 tool. See @uref{http://www.freedesktop.org/software/colord/, the colord web
12713 site} for more information.
12716 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
12717 Return a configuration allowing an application to access GeoClue
12718 location data. @var{name} is the Desktop ID of the application, without
12719 the @code{.desktop} part. If @var{allowed?} is true, the application
12720 will have access to location information by default. The boolean
12721 @var{system?} value indicates whether an application is a system component
12722 or not. Finally @var{users} is a list of UIDs of all users for which
12723 this application is allowed location info access. An empty users list
12724 means that all users are allowed.
12727 @defvr {Scheme Variable} %standard-geoclue-applications
12728 The standard list of well-known GeoClue application configurations,
12729 granting authority to the GNOME date-and-time utility to ask for the
12730 current location in order to set the time zone, and allowing the
12731 IceCat and Epiphany web browsers to request location information.
12732 IceCat and Epiphany both query the user before allowing a web page to
12733 know the user's location.
12736 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
12737 [#:whitelist '()] @
12738 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
12739 [#:submit-data? #f]
12740 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
12741 [#:submission-nick "geoclue"] @
12742 [#:applications %standard-geoclue-applications]
12743 Return a service that runs the GeoClue location service. This service
12744 provides a D-Bus interface to allow applications to request access to a
12745 user's physical location, and optionally to add information to online
12746 location databases. See
12747 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
12748 web site} for more information.
12751 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
12752 [@w{#:auto-enable? #f}]
12753 Return a service that runs the @command{bluetoothd} daemon, which
12754 manages all the Bluetooth devices and provides a number of D-Bus
12755 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
12756 powered automatically at boot, which can be useful when using a
12757 bluetooth keyboard or mouse.
12759 Users need to be in the @code{lp} group to access the D-Bus service.
12762 @node Database Services
12763 @subsubsection Database Services
12767 The @code{(gnu services databases)} module provides the following services.
12769 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
12770 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
12771 [#:port 5432] [#:locale ``en_US.utf8'']
12772 Return a service that runs @var{postgresql}, the PostgreSQL database
12775 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
12776 creates a database cluster with @var{locale} as the default
12777 locale, stored in @var{data-directory}. It then listens on @var{port}.
12780 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
12781 Return a service that runs @command{mysqld}, the MySQL or MariaDB
12784 The optional @var{config} argument specifies the configuration for
12785 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
12788 @deftp {Data Type} mysql-configuration
12789 Data type representing the configuration of @var{mysql-service}.
12792 @item @code{mysql} (default: @var{mariadb})
12793 Package object of the MySQL database server, can be either @var{mariadb}
12796 For MySQL, a temporary root password will be displayed at activation time.
12797 For MariaDB, the root password is empty.
12799 @item @code{port} (default: @code{3306})
12800 TCP port on which the database server listens for incoming connections.
12804 @defvr {Scheme Variable} memcached-service-type
12805 This is the service type for the @uref{https://memcached.org/,
12806 Memcached} service, which provides a distributed in memory cache. The
12807 value for the service type is a @code{memcached-configuration} object.
12811 (service memcached-service-type)
12814 @deftp {Data Type} memcached-configuration
12815 Data type representing the configuration of memcached.
12818 @item @code{memcached} (default: @code{memcached})
12819 The Memcached package to use.
12821 @item @code{interfaces} (default: @code{'("0.0.0.0")})
12822 Network interfaces on which to listen.
12824 @item @code{tcp-port} (default: @code{11211})
12825 Port on which to accept connections on,
12827 @item @code{udp-port} (default: @code{11211})
12828 Port on which to accept UDP connections on, a value of 0 will disable
12829 listening on a UDP socket.
12831 @item @code{additional-options} (default: @code{'()})
12832 Additional command line options to pass to @code{memcached}.
12836 @defvr {Scheme Variable} mongodb-service-type
12837 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
12838 The value for the service type is a @code{mongodb-configuration} object.
12842 (service mongodb-service-type)
12845 @deftp {Data Type} mongodb-configuration
12846 Data type representing the configuration of mongodb.
12849 @item @code{mongodb} (default: @code{mongodb})
12850 The MongoDB package to use.
12852 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
12853 The configuration file for MongoDB.
12855 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
12856 This value is used to create the directory, so that it exists and is
12857 owned by the mongodb user. It should match the data-directory which
12858 MongoDB is configured to use through the configuration file.
12862 @defvr {Scheme Variable} redis-service-type
12863 This is the service type for the @uref{https://redis.io/, Redis}
12864 key/value store, whose value is a @code{redis-configuration} object.
12867 @deftp {Data Type} redis-configuration
12868 Data type representing the configuration of redis.
12871 @item @code{redis} (default: @code{redis})
12872 The Redis package to use.
12874 @item @code{bind} (default: @code{"127.0.0.1"})
12875 Network interface on which to listen.
12877 @item @code{port} (default: @code{6379})
12878 Port on which to accept connections on, a value of 0 will disable
12879 listening on a TCP socket.
12881 @item @code{working-directory} (default: @code{"/var/lib/redis"})
12882 Directory in which to store the database and related files.
12886 @node Mail Services
12887 @subsubsection Mail Services
12891 The @code{(gnu services mail)} module provides Guix service definitions
12892 for email services: IMAP, POP3, and LMTP servers, as well as mail
12893 transport agents (MTAs). Lots of acronyms! These services are detailed
12894 in the subsections below.
12896 @subsubheading Dovecot Service
12898 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
12899 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
12902 By default, Dovecot does not need much configuration; the default
12903 configuration object created by @code{(dovecot-configuration)} will
12904 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
12905 certificate will be generated for TLS-protected connections, though
12906 Dovecot will also listen on cleartext ports by default. There are a
12907 number of options, though, which mail administrators might need to change,
12908 and as is the case with other services, Guix allows the system
12909 administrator to specify these parameters via a uniform Scheme interface.
12911 For example, to specify that mail is located at @code{maildir~/.mail},
12912 one would instantiate the Dovecot service like this:
12915 (dovecot-service #:config
12916 (dovecot-configuration
12917 (mail-location "maildir:~/.mail")))
12920 The available configuration parameters follow. Each parameter
12921 definition is preceded by its type; for example, @samp{string-list foo}
12922 indicates that the @code{foo} parameter should be specified as a list of
12923 strings. There is also a way to specify the configuration as a string,
12924 if you have an old @code{dovecot.conf} file that you want to port over
12925 from some other system; see the end for more details.
12927 @c The following documentation was initially generated by
12928 @c (generate-documentation) in (gnu services mail). Manually maintained
12929 @c documentation is better, so we shouldn't hesitate to edit below as
12930 @c needed. However if the change you want to make to this documentation
12931 @c can be done in an automated way, it's probably easier to change
12932 @c (generate-documentation) than to make it below and have to deal with
12933 @c the churn as dovecot updates.
12935 Available @code{dovecot-configuration} fields are:
12937 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
12938 The dovecot package.
12941 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
12942 A list of IPs or hosts where to listen for connections. @samp{*}
12943 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
12944 interfaces. If you want to specify non-default ports or anything more
12945 complex, customize the address and port fields of the
12946 @samp{inet-listener} of the specific services you are interested in.
12949 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
12950 List of protocols we want to serve. Available protocols include
12951 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
12953 Available @code{protocol-configuration} fields are:
12955 @deftypevr {@code{protocol-configuration} parameter} string name
12956 The name of the protocol.
12959 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
12960 UNIX socket path to the master authentication server to find users.
12961 This is used by imap (for shared users) and lda.
12962 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
12965 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
12966 Space separated list of plugins to load.
12969 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
12970 Maximum number of IMAP connections allowed for a user from each IP
12971 address. NOTE: The username is compared case-sensitively.
12972 Defaults to @samp{10}.
12977 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
12978 List of services to enable. Available services include @samp{imap},
12979 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
12982 Available @code{service-configuration} fields are:
12984 @deftypevr {@code{service-configuration} parameter} string kind
12985 The service kind. Valid values include @code{director},
12986 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
12987 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
12988 @code{tcpwrap}, @code{quota-warning}, or anything else.
12991 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
12992 Listeners for the service. A listener is either a
12993 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
12994 an @code{inet-listener-configuration}.
12995 Defaults to @samp{()}.
12997 Available @code{unix-listener-configuration} fields are:
12999 @deftypevr {@code{unix-listener-configuration} parameter} string path
13000 Path to the file, relative to @code{base-dir} field. This is also used as
13004 @deftypevr {@code{unix-listener-configuration} parameter} string mode
13005 The access mode for the socket.
13006 Defaults to @samp{"0600"}.
13009 @deftypevr {@code{unix-listener-configuration} parameter} string user
13010 The user to own the socket.
13011 Defaults to @samp{""}.
13014 @deftypevr {@code{unix-listener-configuration} parameter} string group
13015 The group to own the socket.
13016 Defaults to @samp{""}.
13020 Available @code{fifo-listener-configuration} fields are:
13022 @deftypevr {@code{fifo-listener-configuration} parameter} string path
13023 Path to the file, relative to @code{base-dir} field. This is also used as
13027 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
13028 The access mode for the socket.
13029 Defaults to @samp{"0600"}.
13032 @deftypevr {@code{fifo-listener-configuration} parameter} string user
13033 The user to own the socket.
13034 Defaults to @samp{""}.
13037 @deftypevr {@code{fifo-listener-configuration} parameter} string group
13038 The group to own the socket.
13039 Defaults to @samp{""}.
13043 Available @code{inet-listener-configuration} fields are:
13045 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
13046 The protocol to listen for.
13049 @deftypevr {@code{inet-listener-configuration} parameter} string address
13050 The address on which to listen, or empty for all addresses.
13051 Defaults to @samp{""}.
13054 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
13055 The port on which to listen.
13058 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
13059 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
13061 Defaults to @samp{#t}.
13066 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
13067 Number of connections to handle before starting a new process.
13068 Typically the only useful values are 0 (unlimited) or 1. 1 is more
13069 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
13070 Defaults to @samp{1}.
13073 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
13074 Number of processes to always keep waiting for more connections.
13075 Defaults to @samp{0}.
13078 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
13079 If you set @samp{service-count 0}, you probably need to grow
13081 Defaults to @samp{256000000}.
13086 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
13087 Dict configuration, as created by the @code{dict-configuration}
13090 Available @code{dict-configuration} fields are:
13092 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
13093 A list of key-value pairs that this dict should hold.
13094 Defaults to @samp{()}.
13099 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
13100 A list of passdb configurations, each one created by the
13101 @code{passdb-configuration} constructor.
13103 Available @code{passdb-configuration} fields are:
13105 @deftypevr {@code{passdb-configuration} parameter} string driver
13106 The driver that the passdb should use. Valid values include
13107 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
13109 Defaults to @samp{"pam"}.
13112 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
13113 Space separated list of arguments to the passdb driver.
13114 Defaults to @samp{""}.
13119 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
13120 List of userdb configurations, each one created by the
13121 @code{userdb-configuration} constructor.
13123 Available @code{userdb-configuration} fields are:
13125 @deftypevr {@code{userdb-configuration} parameter} string driver
13126 The driver that the userdb should use. Valid values include
13127 @samp{passwd} and @samp{static}.
13128 Defaults to @samp{"passwd"}.
13131 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
13132 Space separated list of arguments to the userdb driver.
13133 Defaults to @samp{""}.
13136 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
13137 Override fields from passwd.
13138 Defaults to @samp{()}.
13143 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
13144 Plug-in configuration, created by the @code{plugin-configuration}
13148 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
13149 List of namespaces. Each item in the list is created by the
13150 @code{namespace-configuration} constructor.
13152 Available @code{namespace-configuration} fields are:
13154 @deftypevr {@code{namespace-configuration} parameter} string name
13155 Name for this namespace.
13158 @deftypevr {@code{namespace-configuration} parameter} string type
13159 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
13160 Defaults to @samp{"private"}.
13163 @deftypevr {@code{namespace-configuration} parameter} string separator
13164 Hierarchy separator to use. You should use the same separator for
13165 all namespaces or some clients get confused. @samp{/} is usually a good
13166 one. The default however depends on the underlying mail storage
13168 Defaults to @samp{""}.
13171 @deftypevr {@code{namespace-configuration} parameter} string prefix
13172 Prefix required to access this namespace. This needs to be
13173 different for all namespaces. For example @samp{Public/}.
13174 Defaults to @samp{""}.
13177 @deftypevr {@code{namespace-configuration} parameter} string location
13178 Physical location of the mailbox. This is in the same format as
13179 mail_location, which is also the default for it.
13180 Defaults to @samp{""}.
13183 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
13184 There can be only one INBOX, and this setting defines which
13186 Defaults to @samp{#f}.
13189 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
13190 If namespace is hidden, it's not advertised to clients via NAMESPACE
13191 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
13192 useful when converting from another server with different namespaces
13193 which you want to deprecate but still keep working. For example you can
13194 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
13196 Defaults to @samp{#f}.
13199 @deftypevr {@code{namespace-configuration} parameter} boolean list?
13200 Show the mailboxes under this namespace with the LIST command. This
13201 makes the namespace visible for clients that do not support the NAMESPACE
13202 extension. The special @code{children} value lists child mailboxes, but
13203 hides the namespace prefix.
13204 Defaults to @samp{#t}.
13207 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
13208 Namespace handles its own subscriptions. If set to @code{#f}, the
13209 parent namespace handles them. The empty prefix should always have this
13211 Defaults to @samp{#t}.
13214 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
13215 List of predefined mailboxes in this namespace.
13216 Defaults to @samp{()}.
13218 Available @code{mailbox-configuration} fields are:
13220 @deftypevr {@code{mailbox-configuration} parameter} string name
13221 Name for this mailbox.
13224 @deftypevr {@code{mailbox-configuration} parameter} string auto
13225 @samp{create} will automatically create this mailbox.
13226 @samp{subscribe} will both create and subscribe to the mailbox.
13227 Defaults to @samp{"no"}.
13230 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
13231 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
13232 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
13233 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
13234 Defaults to @samp{()}.
13241 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
13242 Base directory where to store runtime data.
13243 Defaults to @samp{"/var/run/dovecot/"}.
13246 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
13247 Greeting message for clients.
13248 Defaults to @samp{"Dovecot ready."}.
13251 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
13252 List of trusted network ranges. Connections from these IPs are
13253 allowed to override their IP addresses and ports (for logging and for
13254 authentication checks). @samp{disable-plaintext-auth} is also ignored
13255 for these networks. Typically you would specify your IMAP proxy servers
13257 Defaults to @samp{()}.
13260 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
13261 List of login access check sockets (e.g. tcpwrap).
13262 Defaults to @samp{()}.
13265 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
13266 Show more verbose process titles (in ps). Currently shows user name
13267 and IP address. Useful for seeing who is actually using the IMAP
13268 processes (e.g. shared mailboxes or if the same uid is used for multiple
13270 Defaults to @samp{#f}.
13273 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
13274 Should all processes be killed when Dovecot master process shuts down.
13275 Setting this to @code{#f} means that Dovecot can be upgraded without
13276 forcing existing client connections to close (although that could also
13277 be a problem if the upgrade is e.g. due to a security fix).
13278 Defaults to @samp{#t}.
13281 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
13282 If non-zero, run mail commands via this many connections to doveadm
13283 server, instead of running them directly in the same process.
13284 Defaults to @samp{0}.
13287 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
13288 UNIX socket or host:port used for connecting to doveadm server.
13289 Defaults to @samp{"doveadm-server"}.
13292 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
13293 List of environment variables that are preserved on Dovecot startup
13294 and passed down to all of its child processes. You can also give
13295 key=value pairs to always set specific settings.
13298 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
13299 Disable LOGIN command and all other plaintext authentications unless
13300 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
13301 matches the local IP (i.e. you're connecting from the same computer),
13302 the connection is considered secure and plaintext authentication is
13303 allowed. See also ssl=required setting.
13304 Defaults to @samp{#t}.
13307 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
13308 Authentication cache size (e.g. @samp{#e10e6}). 0 means it's disabled.
13309 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
13310 for caching to be used.
13311 Defaults to @samp{0}.
13314 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
13315 Time to live for cached data. After TTL expires the cached record
13316 is no longer used, *except* if the main database lookup returns internal
13317 failure. We also try to handle password changes automatically: If
13318 user's previous authentication was successful, but this one wasn't, the
13319 cache isn't used. For now this works only with plaintext
13321 Defaults to @samp{"1 hour"}.
13324 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
13325 TTL for negative hits (user not found, password mismatch).
13326 0 disables caching them completely.
13327 Defaults to @samp{"1 hour"}.
13330 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
13331 List of realms for SASL authentication mechanisms that need them.
13332 You can leave it empty if you don't want to support multiple realms.
13333 Many clients simply use the first one listed here, so keep the default
13335 Defaults to @samp{()}.
13338 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
13339 Default realm/domain to use if none was specified. This is used for
13340 both SASL realms and appending @@domain to username in plaintext
13342 Defaults to @samp{""}.
13345 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
13346 List of allowed characters in username. If the user-given username
13347 contains a character not listed in here, the login automatically fails.
13348 This is just an extra check to make sure user can't exploit any
13349 potential quote escaping vulnerabilities with SQL/LDAP databases. If
13350 you want to allow all characters, set this value to empty.
13351 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
13354 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
13355 Username character translations before it's looked up from
13356 databases. The value contains series of from -> to characters. For
13357 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
13358 translated to @samp{@@}.
13359 Defaults to @samp{""}.
13362 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
13363 Username formatting before it's looked up from databases. You can
13364 use the standard variables here, e.g. %Lu would lowercase the username,
13365 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
13366 change the @samp{@@} into @samp{-AT-}. This translation is done after
13367 @samp{auth-username-translation} changes.
13368 Defaults to @samp{"%Lu"}.
13371 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
13372 If you want to allow master users to log in by specifying the master
13373 username within the normal username string (i.e. not using SASL
13374 mechanism's support for it), you can specify the separator character
13375 here. The format is then <username><separator><master username>.
13376 UW-IMAP uses @samp{*} as the separator, so that could be a good
13378 Defaults to @samp{""}.
13381 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
13382 Username to use for users logging in with ANONYMOUS SASL
13384 Defaults to @samp{"anonymous"}.
13387 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
13388 Maximum number of dovecot-auth worker processes. They're used to
13389 execute blocking passdb and userdb queries (e.g. MySQL and PAM).
13390 They're automatically created and destroyed as needed.
13391 Defaults to @samp{30}.
13394 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
13395 Host name to use in GSSAPI principal names. The default is to use
13396 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
13397 allow all keytab entries.
13398 Defaults to @samp{""}.
13401 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
13402 Kerberos keytab to use for the GSSAPI mechanism. Will use the
13403 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
13404 need to change the auth service to run as root to be able to read this
13406 Defaults to @samp{""}.
13409 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
13410 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
13411 and @samp{ntlm-auth} helper.
13412 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
13413 Defaults to @samp{#f}.
13416 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
13417 Path for Samba's @samp{ntlm-auth} helper binary.
13418 Defaults to @samp{"/usr/bin/ntlm_auth"}.
13421 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
13422 Time to delay before replying to failed authentications.
13423 Defaults to @samp{"2 secs"}.
13426 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
13427 Require a valid SSL client certificate or the authentication
13429 Defaults to @samp{#f}.
13432 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
13433 Take the username from client's SSL certificate, using
13434 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
13436 Defaults to @samp{#f}.
13439 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
13440 List of wanted authentication mechanisms. Supported mechanisms are:
13441 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
13442 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
13443 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
13444 @samp{disable-plaintext-auth} setting.
13447 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
13448 List of IPs or hostnames to all director servers, including ourself.
13449 Ports can be specified as ip:port. The default port is the same as what
13450 director service's @samp{inet-listener} is using.
13451 Defaults to @samp{()}.
13454 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
13455 List of IPs or hostnames to all backend mail servers. Ranges are
13456 allowed too, like 10.0.0.10-10.0.0.30.
13457 Defaults to @samp{()}.
13460 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
13461 How long to redirect users to a specific server after it no longer
13462 has any connections.
13463 Defaults to @samp{"15 min"}.
13466 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
13467 How the username is translated before being hashed. Useful values
13468 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
13469 are shared within domain.
13470 Defaults to @samp{"%Lu"}.
13473 @deftypevr {@code{dovecot-configuration} parameter} string log-path
13474 Log file to use for error messages. @samp{syslog} logs to syslog,
13475 @samp{/dev/stderr} logs to stderr.
13476 Defaults to @samp{"syslog"}.
13479 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
13480 Log file to use for informational messages. Defaults to
13482 Defaults to @samp{""}.
13485 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
13486 Log file to use for debug messages. Defaults to
13487 @samp{info-log-path}.
13488 Defaults to @samp{""}.
13491 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
13492 Syslog facility to use if you're logging to syslog. Usually if you
13493 don't want to use @samp{mail}, you'll use local0..local7. Also other
13494 standard facilities are supported.
13495 Defaults to @samp{"mail"}.
13498 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
13499 Log unsuccessful authentication attempts and the reasons why they
13501 Defaults to @samp{#f}.
13504 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose-passwords?
13505 In case of password mismatches, log the attempted password. Valid
13506 values are no, plain and sha1. sha1 can be useful for detecting brute
13507 force password attempts vs. user simply trying the same password over
13508 and over again. You can also truncate the value to n chars by appending
13509 ":n" (e.g. sha1:6).
13510 Defaults to @samp{#f}.
13513 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
13514 Even more verbose logging for debugging purposes. Shows for example
13516 Defaults to @samp{#f}.
13519 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
13520 In case of password mismatches, log the passwords and used scheme so
13521 the problem can be debugged. Enabling this also enables
13523 Defaults to @samp{#f}.
13526 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
13527 Enable mail process debugging. This can help you figure out why
13528 Dovecot isn't finding your mails.
13529 Defaults to @samp{#f}.
13532 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
13533 Show protocol level SSL errors.
13534 Defaults to @samp{#f}.
13537 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
13538 Prefix for each line written to log file. % codes are in
13539 strftime(3) format.
13540 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
13543 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
13544 List of elements we want to log. The elements which have a
13545 non-empty variable value are joined together to form a comma-separated
13549 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
13550 Login log format. %s contains @samp{login-log-format-elements}
13551 string, %$ contains the data we want to log.
13552 Defaults to @samp{"%$: %s"}.
13555 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
13556 Log prefix for mail processes. See doc/wiki/Variables.txt for list
13557 of possible variables you can use.
13558 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
13561 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
13562 Format to use for logging mail deliveries. You can use variables:
13565 Delivery status message (e.g. @samp{saved to INBOX})
13577 Defaults to @samp{"msgid=%m: %$"}.
13580 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
13581 Location for users' mailboxes. The default is empty, which means
13582 that Dovecot tries to find the mailboxes automatically. This won't work
13583 if the user doesn't yet have any mail, so you should explicitly tell
13584 Dovecot the full location.
13586 If you're using mbox, giving a path to the INBOX
13587 file (e.g. /var/mail/%u) isn't enough. You'll also need to tell Dovecot
13588 where the other mailboxes are kept. This is called the "root mail
13589 directory", and it must be the first path given in the
13590 @samp{mail-location} setting.
13592 There are a few special variables you can use, eg.:
13598 user part in user@@domain, same as %u if there's no domain
13600 domain part in user@@domain, empty if there's no domain
13605 See doc/wiki/Variables.txt for full list. Some examples:
13607 @item maildir:~/Maildir
13608 @item mbox:~/mail:INBOX=/var/mail/%u
13609 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
13611 Defaults to @samp{""}.
13614 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
13615 System user and group used to access mails. If you use multiple,
13616 userdb can override these by returning uid or gid fields. You can use
13617 either numbers or names. <doc/wiki/UserIds.txt>.
13618 Defaults to @samp{""}.
13621 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
13623 Defaults to @samp{""}.
13626 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
13627 Group to enable temporarily for privileged operations. Currently
13628 this is used only with INBOX when either its initial creation or
13629 dotlocking fails. Typically this is set to "mail" to give access to
13631 Defaults to @samp{""}.
13634 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
13635 Grant access to these supplementary groups for mail processes.
13636 Typically these are used to set up access to shared mailboxes. Note
13637 that it may be dangerous to set these if users can create
13638 symlinks (e.g. if "mail" group is set here, ln -s /var/mail ~/mail/var
13639 could allow a user to delete others' mailboxes, or ln -s
13640 /secret/shared/box ~/mail/mybox would allow reading it).
13641 Defaults to @samp{""}.
13644 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
13645 Allow full file system access to clients. There's no access checks
13646 other than what the operating system does for the active UID/GID. It
13647 works with both maildir and mboxes, allowing you to prefix mailboxes
13648 names with e.g. /path/ or ~user/.
13649 Defaults to @samp{#f}.
13652 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
13653 Don't use mmap() at all. This is required if you store indexes to
13654 shared file systems (NFS or clustered file system).
13655 Defaults to @samp{#f}.
13658 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
13659 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
13660 supports @samp{O_EXCL} since version 3, so this should be safe to use
13661 nowadays by default.
13662 Defaults to @samp{#t}.
13665 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
13666 When to use fsync() or fdatasync() calls:
13669 Whenever necessary to avoid losing important data
13671 Useful with e.g. NFS when write()s are delayed
13673 Never use it (best performance, but crashes can lose data).
13675 Defaults to @samp{"optimized"}.
13678 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
13679 Mail storage exists in NFS. Set this to yes to make Dovecot flush
13680 NFS caches whenever needed. If you're using only a single mail server
13682 Defaults to @samp{#f}.
13685 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
13686 Mail index files also exist in NFS. Setting this to yes requires
13687 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
13688 Defaults to @samp{#f}.
13691 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
13692 Locking method for index files. Alternatives are fcntl, flock and
13693 dotlock. Dotlocking uses some tricks which may create more disk I/O
13694 than other locking methods. NFS users: flock doesn't work, remember to
13695 change @samp{mmap-disable}.
13696 Defaults to @samp{"fcntl"}.
13699 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
13700 Directory in which LDA/LMTP temporarily stores incoming mails >128
13702 Defaults to @samp{"/tmp"}.
13705 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
13706 Valid UID range for users. This is mostly to make sure that users can't
13707 log in as daemons or other system users. Note that denying root logins is
13708 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
13710 Defaults to @samp{500}.
13713 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
13715 Defaults to @samp{0}.
13718 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
13719 Valid GID range for users. Users having non-valid GID as primary group ID
13720 aren't allowed to log in. If user belongs to supplementary groups with
13721 non-valid GIDs, those groups are not set.
13722 Defaults to @samp{1}.
13725 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
13727 Defaults to @samp{0}.
13730 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
13731 Maximum allowed length for mail keyword name. It's only forced when
13732 trying to create new keywords.
13733 Defaults to @samp{50}.
13736 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
13737 List of directories under which chrooting is allowed for mail
13738 processes (i.e. /var/mail will allow chrooting to /var/mail/foo/bar
13739 too). This setting doesn't affect @samp{login-chroot}
13740 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
13741 "/./" in home dirs are ignored. WARNING: Never add directories here
13742 which local users can modify, that may lead to root exploit. Usually
13743 this should be done only if you don't allow shell access for users.
13744 <doc/wiki/Chrooting.txt>.
13745 Defaults to @samp{()}.
13748 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
13749 Default chroot directory for mail processes. This can be overridden
13750 for specific users in user database by giving /./ in user's home
13751 directory (e.g. /home/./user chroots into /home). Note that usually
13752 there is no real need to do chrooting, Dovecot doesn't allow users to
13753 access files outside their mail directory anyway. If your home
13754 directories are prefixed with the chroot directory, append "/." to
13755 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
13756 Defaults to @samp{""}.
13759 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
13760 UNIX socket path to master authentication server to find users.
13761 This is used by imap (for shared users) and lda.
13762 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
13765 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
13766 Directory where to look up mail plugins.
13767 Defaults to @samp{"/usr/lib/dovecot"}.
13770 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
13771 List of plugins to load for all services. Plugins specific to IMAP,
13772 LDA, etc. are added to this list in their own .conf files.
13773 Defaults to @samp{()}.
13776 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
13777 The minimum number of mails in a mailbox before updates are done to
13778 cache file. This allows optimizing Dovecot's behavior to do less disk
13779 writes at the cost of more disk reads.
13780 Defaults to @samp{0}.
13783 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
13784 When IDLE command is running, mailbox is checked once in a while to
13785 see if there are any new mails or other changes. This setting defines
13786 the minimum time to wait between those checks. Dovecot can also use
13787 dnotify, inotify and kqueue to find out immediately when changes
13789 Defaults to @samp{"30 secs"}.
13792 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
13793 Save mails with CR+LF instead of plain LF. This makes sending those
13794 mails take less CPU, especially with sendfile() syscall with Linux and
13795 FreeBSD. But it also creates a bit more disk I/O which may just make it
13796 slower. Also note that if other software reads the mboxes/maildirs,
13797 they may handle the extra CRs wrong and cause problems.
13798 Defaults to @samp{#f}.
13801 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
13802 By default LIST command returns all entries in maildir beginning
13803 with a dot. Enabling this option makes Dovecot return only entries
13804 which are directories. This is done by stat()ing each entry, so it
13805 causes more disk I/O.
13806 (For systems setting struct @samp{dirent->d_type} this check is free
13807 and it's done always regardless of this setting).
13808 Defaults to @samp{#f}.
13811 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
13812 When copying a message, do it with hard links whenever possible.
13813 This makes the performance much better, and it's unlikely to have any
13815 Defaults to @samp{#t}.
13818 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
13819 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
13820 directory only when its mtime changes unexpectedly or when we can't find
13821 the mail otherwise.
13822 Defaults to @samp{#f}.
13825 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
13826 Which locking methods to use for locking mbox. There are four
13831 Create <mailbox>.lock file. This is the oldest and most NFS-safe
13832 solution. If you want to use /var/mail/ like directory, the users will
13833 need write access to that directory.
13835 Same as dotlock, but if it fails because of permissions or because there
13836 isn't enough disk space, just skip it.
13838 Use this if possible. Works with NFS too if lockd is used.
13840 May not exist in all systems. Doesn't work with NFS.
13842 May not exist in all systems. Doesn't work with NFS.
13845 You can use multiple locking methods; if you do the order they're declared
13846 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
13847 locking methods as well. Some operating systems don't allow using some of
13848 them simultaneously.
13851 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
13855 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
13856 Maximum time to wait for lock (all of them) before aborting.
13857 Defaults to @samp{"5 mins"}.
13860 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
13861 If dotlock exists but the mailbox isn't modified in any way,
13862 override the lock file after this much time.
13863 Defaults to @samp{"2 mins"}.
13866 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
13867 When mbox changes unexpectedly we have to fully read it to find out
13868 what changed. If the mbox is large this can take a long time. Since
13869 the change is usually just a newly appended mail, it'd be faster to
13870 simply read the new mails. If this setting is enabled, Dovecot does
13871 this but still safely fallbacks to re-reading the whole mbox file
13872 whenever something in mbox isn't how it's expected to be. The only real
13873 downside to this setting is that if some other MUA changes message
13874 flags, Dovecot doesn't notice it immediately. Note that a full sync is
13875 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
13876 Defaults to @samp{#t}.
13879 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
13880 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
13881 EXAMINE, EXPUNGE or CHECK commands. If this is set,
13882 @samp{mbox-dirty-syncs} is ignored.
13883 Defaults to @samp{#f}.
13886 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
13887 Delay writing mbox headers until doing a full write sync (EXPUNGE
13888 and CHECK commands and when closing the mailbox). This is especially
13889 useful for POP3 where clients often delete all mails. The downside is
13890 that our changes aren't immediately visible to other MUAs.
13891 Defaults to @samp{#t}.
13894 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
13895 If mbox size is smaller than this (e.g. 100k), don't write index
13896 files. If an index file already exists it's still read, just not
13898 Defaults to @samp{0}.
13901 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
13902 Maximum dbox file size until it's rotated.
13903 Defaults to @samp{10000000}.
13906 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
13907 Maximum dbox file age until it's rotated. Typically in days. Day
13908 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
13910 Defaults to @samp{"1d"}.
13913 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
13914 When creating new mdbox files, immediately preallocate their size to
13915 @samp{mdbox-rotate-size}. This setting currently works only in Linux
13916 with some file systems (ext4, xfs).
13917 Defaults to @samp{#f}.
13920 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
13921 sdbox and mdbox support saving mail attachments to external files,
13922 which also allows single instance storage for them. Other backends
13923 don't support this for now.
13925 WARNING: This feature hasn't been tested much yet. Use at your own risk.
13927 Directory root where to store mail attachments. Disabled, if empty.
13928 Defaults to @samp{""}.
13931 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
13932 Attachments smaller than this aren't saved externally. It's also
13933 possible to write a plugin to disable saving specific attachments
13935 Defaults to @samp{128000}.
13938 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
13939 File system backend to use for saving attachments:
13942 No SiS done by Dovecot (but this might help FS's own deduplication)
13944 SiS with immediate byte-by-byte comparison during saving
13945 @item sis-queue posix
13946 SiS with delayed comparison and deduplication.
13948 Defaults to @samp{"sis posix"}.
13951 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
13952 Hash format to use in attachment filenames. You can add any text and
13953 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
13954 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
13955 truncated, e.g. @code{%@{sha256:80@}} returns only first 80 bits.
13956 Defaults to @samp{"%@{sha1@}"}.
13959 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
13961 Defaults to @samp{100}.
13964 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
13966 Defaults to @samp{1000}.
13969 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
13970 Default VSZ (virtual memory size) limit for service processes.
13971 This is mainly intended to catch and kill processes that leak memory
13972 before they eat up everything.
13973 Defaults to @samp{256000000}.
13976 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
13977 Login user is internally used by login processes. This is the most
13978 untrusted user in Dovecot system. It shouldn't have access to anything
13980 Defaults to @samp{"dovenull"}.
13983 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
13984 Internal user is used by unprivileged processes. It should be
13985 separate from login user, so that login processes can't disturb other
13987 Defaults to @samp{"dovecot"}.
13990 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
13991 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
13992 Defaults to @samp{"required"}.
13995 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
13996 PEM encoded X.509 SSL/TLS certificate (public key).
13997 Defaults to @samp{"</etc/dovecot/default.pem"}.
14000 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
14001 PEM encoded SSL/TLS private key. The key is opened before
14002 dropping root privileges, so keep the key file unreadable by anyone but
14004 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
14007 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
14008 If key file is password protected, give the password here.
14009 Alternatively give it when starting dovecot with -p parameter. Since
14010 this file is often world-readable, you may want to place this setting
14011 instead to a different.
14012 Defaults to @samp{""}.
14015 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
14016 PEM encoded trusted certificate authority. Set this only if you
14017 intend to use @samp{ssl-verify-client-cert? #t}. The file should
14018 contain the CA certificate(s) followed by the matching
14019 CRL(s). (e.g. @samp{ssl-ca </etc/ssl/certs/ca.pem}).
14020 Defaults to @samp{""}.
14023 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
14024 Require that CRL check succeeds for client certificates.
14025 Defaults to @samp{#t}.
14028 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
14029 Request client to send a certificate. If you also want to require
14030 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
14031 Defaults to @samp{#f}.
14034 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
14035 Which field from certificate to use for username. commonName and
14036 x500UniqueIdentifier are the usual choices. You'll also need to set
14037 @samp{auth-ssl-username-from-cert? #t}.
14038 Defaults to @samp{"commonName"}.
14041 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
14042 Minimum SSL protocol version to accept.
14043 Defaults to @samp{"TLSv1"}.
14046 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
14047 SSL ciphers to use.
14048 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
14051 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
14052 SSL crypto device to use, for valid values run "openssl engine".
14053 Defaults to @samp{""}.
14056 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
14057 Address to use when sending rejection mails.
14058 %d expands to recipient domain.
14059 Defaults to @samp{"postmaster@@%d"}.
14062 @deftypevr {@code{dovecot-configuration} parameter} string hostname
14063 Hostname to use in various parts of sent mails (e.g. in Message-Id)
14064 and in LMTP replies. Default is the system's real hostname@@domain.
14065 Defaults to @samp{""}.
14068 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
14069 If user is over quota, return with temporary failure instead of
14071 Defaults to @samp{#f}.
14074 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
14075 Binary to use for sending mails.
14076 Defaults to @samp{"/usr/sbin/sendmail"}.
14079 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
14080 If non-empty, send mails via this SMTP host[:port] instead of
14082 Defaults to @samp{""}.
14085 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
14086 Subject: header to use for rejection mails. You can use the same
14087 variables as for @samp{rejection-reason} below.
14088 Defaults to @samp{"Rejected: %s"}.
14091 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
14092 Human readable error message for rejection mails. You can use
14105 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
14108 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
14109 Delimiter character between local-part and detail in email
14111 Defaults to @samp{"+"}.
14114 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
14115 Header where the original recipient address (SMTP's RCPT TO:
14116 address) is taken from if not available elsewhere. With dovecot-lda -a
14117 parameter overrides this. A commonly used header for this is
14119 Defaults to @samp{""}.
14122 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
14123 Should saving a mail to a nonexistent mailbox automatically create
14125 Defaults to @samp{#f}.
14128 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
14129 Should automatically created mailboxes be also automatically
14131 Defaults to @samp{#f}.
14134 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
14135 Maximum IMAP command line length. Some clients generate very long
14136 command lines with huge mailboxes, so you may need to raise this if you
14137 get "Too long argument" or "IMAP command line too large" errors
14139 Defaults to @samp{64000}.
14142 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
14143 IMAP logout format string:
14146 total number of bytes read from client
14148 total number of bytes sent to client.
14150 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
14151 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@}"}.
14154 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
14155 Override the IMAP CAPABILITY response. If the value begins with '+',
14156 add the given capabilities on top of the defaults (e.g. +XFOO XBAR).
14157 Defaults to @samp{""}.
14160 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
14161 How long to wait between "OK Still here" notifications when client
14163 Defaults to @samp{"2 mins"}.
14166 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
14167 ID field names and values to send to clients. Using * as the value
14168 makes Dovecot use the default value. The following fields have default
14169 values currently: name, version, os, os-version, support-url,
14171 Defaults to @samp{""}.
14174 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
14175 ID fields sent by client to log. * means everything.
14176 Defaults to @samp{""}.
14179 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
14180 Workarounds for various client bugs:
14183 @item delay-newmail
14184 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
14185 CHECK commands. Some clients ignore them otherwise, for example OSX
14186 Mail (<v2.1). Outlook Express breaks more badly though, without this it
14187 may show user "Message no longer in server" errors. Note that OE6
14188 still breaks even with this workaround if synchronization is set to
14191 @item tb-extra-mailbox-sep
14192 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
14193 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
14194 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
14196 @item tb-lsub-flags
14197 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g. mbox).
14198 This makes Thunderbird realize they aren't selectable and show them
14199 greyed out, instead of only later giving "not selectable" popup error.
14201 Defaults to @samp{()}.
14204 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
14205 Host allowed in URLAUTH URLs sent by client. "*" allows all.
14206 Defaults to @samp{""}.
14210 Whew! Lots of configuration options. The nice thing about it though is
14211 that GuixSD has a complete interface to Dovecot's configuration
14212 language. This allows not only a nice way to declare configurations,
14213 but also offers reflective capabilities as well: users can write code to
14214 inspect and transform configurations from within Scheme.
14216 However, it could be that you just want to get a @code{dovecot.conf} up
14217 and running. In that case, you can pass an
14218 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
14219 @code{dovecot-service}. As its name indicates, an opaque configuration
14220 does not have easy reflective capabilities.
14222 Available @code{opaque-dovecot-configuration} fields are:
14224 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
14225 The dovecot package.
14228 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
14229 The contents of the @code{dovecot.conf}, as a string.
14232 For example, if your @code{dovecot.conf} is just the empty string, you
14233 could instantiate a dovecot service like this:
14236 (dovecot-service #:config
14237 (opaque-dovecot-configuration
14241 @subsubheading OpenSMTPD Service
14243 @deffn {Scheme Variable} opensmtpd-service-type
14244 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
14245 service, whose value should be an @code{opensmtpd-configuration} object
14246 as in this example:
14249 (service opensmtpd-service-type
14250 (opensmtpd-configuration
14251 (config-file (local-file "./my-smtpd.conf"))))
14255 @deftp {Data Type} opensmtpd-configuration
14256 Data type representing the configuration of opensmtpd.
14259 @item @code{package} (default: @var{opensmtpd})
14260 Package object of the OpenSMTPD SMTP server.
14262 @item @code{config-file} (default: @var{%default-opensmtpd-file})
14263 File-like object of the OpenSMTPD configuration file to use. By default
14264 it listens on the loopback network interface, and allows for mail from
14265 users and daemons on the local machine, as well as permitting email to
14266 remote servers. Run @command{man smtpd.conf} for more information.
14271 @subsubheading Exim Service
14273 @cindex mail transfer agent (MTA)
14274 @cindex MTA (mail transfer agent)
14277 @deffn {Scheme Variable} exim-service-type
14278 This is the type of the @uref{https://exim.org, Exim} mail transfer
14279 agent (MTA), whose value should be an @code{exim-configuration} object
14280 as in this example:
14283 (service exim-service-type
14284 (exim-configuration
14285 (config-file (local-file "./my-exim.conf"))))
14289 In order to use an @code{exim-service-type} service you must also have a
14290 @code{mail-aliases-service-type} service present in your
14291 @code{operating-system} (even if it has no aliases).
14293 @deftp {Data Type} exim-configuration
14294 Data type representing the configuration of exim.
14297 @item @code{package} (default: @var{exim})
14298 Package object of the Exim server.
14300 @item @code{config-file} (default: @code{#f})
14301 File-like object of the Exim configuration file to use. If its value is
14302 @code{#f} then use the default configuration file from the package
14303 provided in @code{package}. The resulting configuration file is loaded
14304 after setting the @code{exim_user} and @code{exim_group} configuration
14310 @subsubheading Mail Aliases Service
14312 @cindex email aliases
14313 @cindex aliases, for email addresses
14315 @deffn {Scheme Variable} mail-aliases-service-type
14316 This is the type of the service which provides @code{/etc/aliases},
14317 specifying how to deliver mail to users on this system.
14320 (service mail-aliases-service-type
14321 '(("postmaster" "bob")
14322 ("bob" "bob@@example.com" "bob@@example2.com")))
14326 The configuration for a @code{mail-aliases-service-type} service is an
14327 association list denoting how to deliver mail that comes to this
14328 system. Each entry is of the form @code{(alias addresses ...)}, with
14329 @code{alias} specifying the local alias and @code{addresses} specifying
14330 where to deliver this user's mail.
14332 The aliases aren't required to exist as users on the local system. In
14333 the above example, there doesn't need to be a @code{postmaster} entry in
14334 the @code{operating-system}'s @code{user-accounts} in order to deliver
14335 the @code{postmaster} mail to @code{bob} (which subsequently would
14336 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
14338 @node Messaging Services
14339 @subsubsection Messaging Services
14344 The @code{(gnu services messaging)} module provides Guix service
14345 definitions for messaging services: currently only Prosody is supported.
14347 @subsubheading Prosody Service
14349 @deffn {Scheme Variable} prosody-service-type
14350 This is the type for the @uref{https://prosody.im, Prosody XMPP
14351 communication server}. Its value must be a @code{prosody-configuration}
14352 record as in this example:
14355 (service prosody-service-type
14356 (prosody-configuration
14357 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
14360 (int-component-configuration
14361 (hostname "conference.example.net")
14363 (mod-muc (mod-muc-configuration)))))
14366 (virtualhost-configuration
14367 (domain "example.net"))))))
14370 See below for details about @code{prosody-configuration}.
14374 By default, Prosody does not need much configuration. Only one
14375 @code{virtualhosts} field is needed: it specifies the domain you wish
14378 You can perform various sanity checks on the generated configuration
14379 with the @code{prosodyctl check} command.
14381 Prosodyctl will also help you to import certificates from the
14382 @code{letsencrypt} directory so that the @code{prosody} user can access
14383 them. See @url{https://prosody.im/doc/letsencrypt}.
14386 prosodyctl --root cert import /etc/letsencrypt/live
14389 The available configuration parameters follow. Each parameter
14390 definition is preceded by its type; for example, @samp{string-list foo}
14391 indicates that the @code{foo} parameter should be specified as a list of
14392 strings. Types starting with @code{maybe-} denote parameters that won't
14393 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
14395 There is also a way to specify the configuration as a string, if you
14396 have an old @code{prosody.cfg.lua} file that you want to port over from
14397 some other system; see the end for more details.
14399 The @code{file-object} type designates either a file-like object
14400 (@pxref{G-Expressions, file-like objects}) or a file name.
14402 @c The following documentation was initially generated by
14403 @c (generate-documentation) in (gnu services messaging). Manually maintained
14404 @c documentation is better, so we shouldn't hesitate to edit below as
14405 @c needed. However if the change you want to make to this documentation
14406 @c can be done in an automated way, it's probably easier to change
14407 @c (generate-documentation) than to make it below and have to deal with
14408 @c the churn as Prosody updates.
14410 Available @code{prosody-configuration} fields are:
14412 @deftypevr {@code{prosody-configuration} parameter} package prosody
14413 The Prosody package.
14416 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
14417 Location of the Prosody data storage directory. See
14418 @url{https://prosody.im/doc/configure}.
14419 Defaults to @samp{"/var/lib/prosody"}.
14422 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
14423 Additional plugin directories. They are searched in all the specified
14424 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
14425 Defaults to @samp{()}.
14428 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
14429 Every virtual host and component needs a certificate so that clients and
14430 servers can securely verify its identity. Prosody will automatically load
14431 certificates/keys from the directory specified here.
14432 Defaults to @samp{"/etc/prosody/certs"}.
14435 @deftypevr {@code{prosody-configuration} parameter} string-list admins
14436 This is a list of accounts that are admins for the server. Note that you
14437 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
14438 @url{https://prosody.im/doc/creating_accounts}.
14439 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
14440 Defaults to @samp{()}.
14443 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
14444 Enable use of libevent for better performance under high load. See
14445 @url{https://prosody.im/doc/libevent}.
14446 Defaults to @samp{#f}.
14449 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
14450 This is the list of modules Prosody will load on startup. It looks for
14451 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
14452 Documentation on modules can be found at:
14453 @url{https://prosody.im/doc/modules}.
14454 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
14457 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
14458 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
14459 should you want to disable them then add them to this list.
14460 Defaults to @samp{()}.
14463 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
14464 Path to a text file where the shared groups are defined. If this path is
14465 empty then @samp{mod_groups} does nothing. See
14466 @url{https://prosody.im/doc/modules/mod_groups}.
14467 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
14470 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
14471 Disable account creation by default, for security. See
14472 @url{https://prosody.im/doc/creating_accounts}.
14473 Defaults to @samp{#f}.
14476 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
14477 These are the SSL/TLS-related settings. Most of them are disabled so to
14478 use Prosody's defaults. If you do not completely understand these options, do
14479 not add them to your config, it is easy to lower the security of your server
14480 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
14482 Available @code{ssl-configuration} fields are:
14484 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
14485 This determines what handshake to use.
14488 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
14489 Path to your private key file.
14492 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
14493 Path to your certificate file.
14496 @deftypevr {@code{ssl-configuration} parameter} file-object capath
14497 Path to directory containing root certificates that you wish Prosody to
14498 trust when verifying the certificates of remote servers.
14499 Defaults to @samp{"/etc/ssl/certs"}.
14502 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
14503 Path to a file containing root certificates that you wish Prosody to trust.
14504 Similar to @code{capath} but with all certificates concatenated together.
14507 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
14508 A list of verification options (these mostly map to OpenSSL's
14509 @code{set_verify()} flags).
14512 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
14513 A list of general options relating to SSL/TLS. These map to OpenSSL's
14514 @code{set_options()}. For a full list of options available in LuaSec, see the
14518 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
14519 How long a chain of certificate authorities to check when looking for a
14520 trusted root certificate.
14523 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
14524 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
14525 clients, and in what order.
14528 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
14529 A path to a file containing parameters for Diffie-Hellman key exchange. You
14530 can create such a file with:
14531 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
14534 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
14535 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
14536 @samp{"secp384r1"}.
14539 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
14540 A list of "extra" verification options.
14543 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
14544 Password for encrypted private keys.
14549 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
14550 Whether to force all client-to-server connections to be encrypted or not.
14551 See @url{https://prosody.im/doc/modules/mod_tls}.
14552 Defaults to @samp{#f}.
14555 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
14556 Set of mechanisms that will never be offered. See
14557 @url{https://prosody.im/doc/modules/mod_saslauth}.
14558 Defaults to @samp{("DIGEST-MD5")}.
14561 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
14562 Whether to force all server-to-server connections to be encrypted or not.
14563 See @url{https://prosody.im/doc/modules/mod_tls}.
14564 Defaults to @samp{#f}.
14567 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
14568 Whether to require encryption and certificate authentication. This
14569 provides ideal security, but requires servers you communicate with to support
14570 encryption AND present valid, trusted certificates. See
14571 @url{https://prosody.im/doc/s2s#security}.
14572 Defaults to @samp{#f}.
14575 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
14576 Many servers don't support encryption or have invalid or self-signed
14577 certificates. You can list domains here that will not be required to
14578 authenticate using certificates. They will be authenticated using DNS. See
14579 @url{https://prosody.im/doc/s2s#security}.
14580 Defaults to @samp{()}.
14583 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
14584 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
14585 valid certificates for some domains by specifying a list here. See
14586 @url{https://prosody.im/doc/s2s#security}.
14587 Defaults to @samp{()}.
14590 @deftypevr {@code{prosody-configuration} parameter} string authentication
14591 Select the authentication backend to use. The default provider stores
14592 passwords in plaintext and uses Prosody's configured data storage to store the
14593 authentication data. If you do not trust your server please see
14594 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
14595 about using the hashed backend. See also
14596 @url{https://prosody.im/doc/authentication}
14597 Defaults to @samp{"internal_plain"}.
14600 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
14601 Set logging options. Advanced logging configuration is not yet supported
14602 by the GuixSD Prosody Service. See @url{https://prosody.im/doc/logging}.
14603 Defaults to @samp{"*syslog"}.
14606 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
14607 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
14608 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
14611 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
14612 Maximum allowed size of the HTTP body (in bytes).
14615 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
14616 Some modules expose their own URL in various ways. This URL is built
14617 from the protocol, host and port used. If Prosody sits behind a proxy, the
14618 public URL will be @code{http-external-url} instead. See
14619 @url{https://prosody.im/doc/http#external_url}.
14622 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
14623 A host in Prosody is a domain on which user accounts can be created. For
14624 example if you want your users to have addresses like
14625 @samp{"john.smith@@example.com"} then you need to add a host
14626 @samp{"example.com"}. All options in this list will apply only to this host.
14628 Note: the name "virtual" host is used in configuration to avoid confusion with
14629 the actual physical host that Prosody is installed on. A single Prosody
14630 instance can serve many domains, each one defined as a VirtualHost entry in
14631 Prosody's configuration. Conversely a server that hosts a single domain would
14632 have just one VirtualHost entry.
14634 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
14636 Available @code{virtualhost-configuration} fields are:
14638 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:
14639 @deftypevr {@code{virtualhost-configuration} parameter} string domain
14640 Domain you wish Prosody to serve.
14645 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
14646 Components are extra services on a server which are available to clients,
14647 usually on a subdomain of the main server (such as
14648 @samp{"mycomponent.example.com"}). Example components might be chatroom
14649 servers, user directories, or gateways to other protocols.
14651 Internal components are implemented with Prosody-specific plugins. To add an
14652 internal component, you simply fill the hostname field, and the plugin you wish
14653 to use for the component.
14655 See @url{https://prosody.im/doc/components}.
14656 Defaults to @samp{()}.
14658 Available @code{int-component-configuration} fields are:
14660 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:
14661 @deftypevr {@code{int-component-configuration} parameter} string hostname
14662 Hostname of the component.
14665 @deftypevr {@code{int-component-configuration} parameter} string plugin
14666 Plugin you wish to use for the component.
14669 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
14670 Multi-user chat (MUC) is Prosody's module for allowing you to create
14671 hosted chatrooms/conferences for XMPP users.
14673 General information on setting up and using multi-user chatrooms can be found
14674 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
14675 which you should read if you are new to XMPP chatrooms.
14677 See also @url{https://prosody.im/doc/modules/mod_muc}.
14679 Available @code{mod-muc-configuration} fields are:
14681 @deftypevr {@code{mod-muc-configuration} parameter} string name
14682 The name to return in service discovery responses.
14683 Defaults to @samp{"Prosody Chatrooms"}.
14686 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
14687 If @samp{#t}, this will only allow admins to create new chatrooms.
14688 Otherwise anyone can create a room. The value @samp{"local"} restricts room
14689 creation to users on the service's parent domain. E.g. @samp{user@@example.com}
14690 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
14691 restricts to service administrators only.
14692 Defaults to @samp{#f}.
14695 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
14696 Maximum number of history messages that will be sent to the member that has
14697 just joined the room.
14698 Defaults to @samp{20}.
14705 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
14706 External components use XEP-0114, which most standalone components
14707 support. To add an external component, you simply fill the hostname field. See
14708 @url{https://prosody.im/doc/components}.
14709 Defaults to @samp{()}.
14711 Available @code{ext-component-configuration} fields are:
14713 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:
14714 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
14715 Password which the component will use to log in.
14718 @deftypevr {@code{ext-component-configuration} parameter} string hostname
14719 Hostname of the component.
14724 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
14725 Port(s) Prosody listens on for component connections.
14726 Defaults to @samp{(5347)}.
14729 @deftypevr {@code{prosody-configuration} parameter} string component-interface
14730 Interface Prosody listens on for component connections.
14731 Defaults to @samp{"127.0.0.1"}.
14734 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
14735 Raw content that will be added to the configuration file.
14738 It could be that you just want to get a @code{prosody.cfg.lua}
14739 up and running. In that case, you can pass an
14740 @code{opaque-prosody-configuration} record as the value of
14741 @code{prosody-service-type}. As its name indicates, an opaque configuration
14742 does not have easy reflective capabilities.
14743 Available @code{opaque-prosody-configuration} fields are:
14745 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
14746 The prosody package.
14749 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
14750 The contents of the @code{prosody.cfg.lua} to use.
14753 For example, if your @code{prosody.cfg.lua} is just the empty
14754 string, you could instantiate a prosody service like this:
14757 (service prosody-service-type
14758 (opaque-prosody-configuration
14759 (prosody.cfg.lua "")))
14762 @c end of Prosody auto-generated documentation
14764 @subsubheading BitlBee Service
14766 @cindex IRC (Internet Relay Chat)
14767 @cindex IRC gateway
14768 @url{http://bitlbee.org,BitlBee} is a gateway that provides an IRC
14769 interface to a variety of messaging protocols such as XMPP.
14771 @defvr {Scheme Variable} bitlbee-service-type
14772 This is the service type for the @url{http://bitlbee.org,BitlBee} IRC
14773 gateway daemon. Its value is a @code{bitlbee-configuration} (see
14776 To have BitlBee listen on port 6667 on localhost, add this line to your
14780 (service bitlbee-service-type)
14784 @deftp {Data Type} bitlbee-configuration
14785 This is the configuration for BitlBee, with the following fields:
14788 @item @code{interface} (default: @code{"127.0.0.1"})
14789 @itemx @code{port} (default: @code{6667})
14790 Listen on the network interface corresponding to the IP address
14791 specified in @var{interface}, on @var{port}.
14793 When @var{interface} is @code{127.0.0.1}, only local clients can
14794 connect; when it is @code{0.0.0.0}, connections can come from any
14795 networking interface.
14797 @item @code{package} (default: @code{bitlbee})
14798 The BitlBee package to use.
14800 @item @code{extra-settings} (default: @code{""})
14801 Configuration snippet added as-is to the BitlBee configuration file.
14806 @node Telephony Services
14807 @subsubsection Telephony Services
14809 @cindex Murmur (VoIP server)
14810 @cindex VoIP server
14811 This section describes how to set up and run a Murmur server. Murmur is
14812 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
14815 @deftp {Data Type} murmur-configuration
14816 The service type for the Murmur server. An example configuration can
14820 (service murmur-service-type
14821 (murmur-configuration
14823 "Welcome to this Mumble server running on GuixSD!")
14824 (cert-required? #t) ;disallow text password logins
14825 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
14826 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
14829 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
14830 password with the command that is printed during the activation phase.
14832 It is recommended to register a normal Mumble user account
14833 and grant it admin or moderator rights.
14834 You can use the @code{mumble} client to
14835 login as new normal user, register yourself, and log out.
14836 For the next step login with the name @code{SuperUser} use
14837 the @code{SuperUser} password that you set previously,
14838 and grant your newly registered mumble user administrator or moderator
14839 rights and create some channels.
14841 Available @code{murmur-configuration} fields are:
14844 @item @code{package} (default: @code{mumble})
14845 Package that contains @code{bin/murmurd}.
14847 @item @code{user} (default: @code{"murmur"})
14848 User who will run the Murmur server.
14850 @item @code{group} (default: @code{"murmur"})
14851 Group of the user who will run the murmur server.
14853 @item @code{port} (default: @code{64738})
14854 Port on which the server will listen.
14856 @item @code{welcome-text} (default: @code{""})
14857 Welcome text sent to clients when they connect.
14859 @item @code{server-password} (default: @code{""})
14860 Password the clients have to enter in order to connect.
14862 @item @code{max-users} (default: @code{100})
14863 Maximum of users that can be connected to the server at once.
14865 @item @code{max-user-bandwidth} (default: @code{#f})
14866 Maximum voice traffic a user can send per second.
14868 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
14869 File name of the sqlite database.
14870 The service's user will become the owner of the directory.
14872 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
14873 File name of the log file.
14874 The service's user will become the owner of the directory.
14876 @item @code{autoban-attempts} (default: @code{10})
14877 Maximum number of logins a user can make in @code{autoban-timeframe}
14878 without getting auto banned for @code{autoban-time}.
14880 @item @code{autoban-timeframe} (default: @code{120})
14881 Timeframe for autoban in seconds.
14883 @item @code{autoban-time} (default: @code{300})
14884 Amount of time in seconds for which a client gets banned
14885 when violating the autoban limits.
14887 @item @code{opus-threshold} (default: @code{100})
14888 Percentage of clients that need to support opus
14889 before switching over to opus audio codec.
14891 @item @code{channel-nesting-limit} (default: @code{10})
14892 How deep channels can be nested at maximum.
14894 @item @code{channelname-regex} (default: @code{#f})
14895 A string in from of a Qt regular expression that channel names must conform to.
14897 @item @code{username-regex} (default: @code{#f})
14898 A string in from of a Qt regular expression that user names must conform to.
14900 @item @code{text-message-length} (default: @code{5000})
14901 Maximum size in bytes that a user can send in one text chat message.
14903 @item @code{image-message-length} (default: @code{(* 128 1024)})
14904 Maximum size in bytes that a user can send in one image message.
14906 @item @code{cert-required?} (default: @code{#f})
14907 If it is set to @code{#t} clients that use weak password authentification
14908 will not be accepted. Users must have completed the certificate wizard to join.
14910 @item @code{remember-channel?} (defualt @code{#f})
14911 Should murmur remember the last channel each user was in when they disconnected
14912 and put them into the remembered channel when they rejoin.
14914 @item @code{allow-html?} (default: @code{#f})
14915 Should html be allowed in text messages, user comments, and channel descriptions.
14917 @item @code{allow-ping?} (default: @code{#f})
14918 Setting to true exposes the current user count, the maximum user count, and
14919 the server's maximum bandwidth per client to unauthenticated users. In the
14920 Mumble client, this information is shown in the Connect dialog.
14922 Disabling this setting will prevent public listing of the server.
14924 @item @code{bonjour?} (default: @code{#f})
14925 Should the server advertise itself in the local network through the bonjour protocol.
14927 @item @code{send-version?} (default: @code{#f})
14928 Should the murmur server version be exposed in ping requests.
14930 @item @code{log-days} (default: @code{31})
14931 Murmur also stores logs in the database, which are accessible via RPC.
14932 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
14933 or -1 to disable logging to the database.
14935 @item @code{obfuscate-ips?} (default @code{#t})
14936 Should logged ips be obfuscated to protect the privacy of users.
14938 @item @code{ssl-cert} (default: @code{#f})
14939 File name of the SSL/TLS certificate used for encrypted connections.
14942 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
14944 @item @code{ssl-key} (default: @code{#f})
14945 Filepath to the ssl private key used for encrypted connections.
14947 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
14950 @item @code{ssl-dh-params} (default: @code{#f})
14951 File name of a PEM-encoded file with Diffie-Hellman parameters
14952 for the SSL/TLS encryption. Alternatively you set it to
14953 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
14954 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
14956 @item @code{ssl-ciphers} (default: @code{#f})
14957 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
14960 This option is specified using
14961 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
14962 OpenSSL cipher list notation}.
14964 It is recommended that you try your cipher string using 'openssl ciphers <string>'
14965 before setting it here, to get a feel for which cipher suites you will get.
14966 After setting this option, it is recommend that you inspect your Murmur log
14967 to ensure that Murmur is using the cipher suites that you expected it to.
14969 Note: Changing this option may impact the backwards compatibility of your
14970 Murmur server, and can remove the ability for older Mumble clients to be able
14973 @item @code{public-registration} (default: @code{#f})
14974 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
14976 You can optionally register your server in the public server list that the
14977 @code{mumble} client shows on startup.
14978 You cannot register your server if you have set a @code{server-password},
14979 or set @code{allow-ping} to @code{#f}.
14981 It might take a few hours until it shows up in the public list.
14983 @item @code{file} (default: @code{#f})
14984 Optional alternative override for this configuration.
14988 @deftp {Data Type} murmur-public-registration-configuration
14989 Configuration for public registration of a murmur service.
14993 This is a display name for your server. Not to be confused with the hostname.
14995 @item @code{password}
14996 A password to identify your registration.
14997 Subsequent updates will need the same password. Don't lose your password.
15000 This should be a @code{http://} or @code{https://} link to your web
15003 @item @code{hostname} (default: @code{#f})
15004 By default your server will be listed by its IP address.
15005 If it is set your server will be linked by this host name instead.
15011 @node Monitoring Services
15012 @subsubsection Monitoring Services
15014 @subsubheading Tailon Service
15016 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
15017 viewing and searching log files.
15019 The following example will configure the service with default values.
15020 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
15023 (service tailon-service-type)
15026 The following example customises more of the Tailon configuration,
15027 adding @command{sed} to the list of allowed commands.
15030 (service tailon-service-type
15031 (tailon-configuration
15033 (tailon-configuration-file
15034 (allowed-commands '("tail" "grep" "awk" "sed"))))))
15038 @deftp {Data Type} tailon-configuration
15039 Data type representing the configuration of Tailon.
15040 This type has the following parameters:
15043 @item @code{config-file} (default: @code{(tailon-configuration-file)})
15044 The configuration file to use for Tailon. This can be set to a
15045 @dfn{tailon-configuration-file} record value, or any gexp
15046 (@pxref{G-Expressions}).
15048 For example, to instead use a local file, the @code{local-file} function
15052 (service tailon-service-type
15053 (tailon-configuration
15054 (config-file (local-file "./my-tailon.conf"))))
15057 @item @code{package} (default: @code{tailon})
15058 The tailon package to use.
15063 @deftp {Data Type} tailon-configuration-file
15064 Data type representing the configuration options for Tailon.
15065 This type has the following parameters:
15068 @item @code{files} (default: @code{(list "/var/log")})
15069 List of files to display. The list can include strings for a single file
15070 or directory, or a list, where the first item is the name of a
15071 subsection, and the remaining items are the files or directories in that
15074 @item @code{bind} (default: @code{"localhost:8080"})
15075 Address and port to which Tailon should bind on.
15077 @item @code{relative-root} (default: @code{#f})
15078 URL path to use for Tailon, set to @code{#f} to not use a path.
15080 @item @code{allow-transfers?} (default: @code{#t})
15081 Allow downloading the log files in the web interface.
15083 @item @code{follow-names?} (default: @code{#t})
15084 Allow tailing of not-yet existent files.
15086 @item @code{tail-lines} (default: @code{200})
15087 Number of lines to read initially from each file.
15089 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
15090 Commands to allow running. By default, @code{sed} is disabled.
15092 @item @code{debug?} (default: @code{#f})
15093 Set @code{debug?} to @code{#t} to show debug messages.
15095 @item @code{wrap-lines} (default: @code{#t})
15096 Initial line wrapping state in the web interface. Set to @code{#t} to
15097 initially wrap lines (the default), or to @code{#f} to initially not
15100 @item @code{http-auth} (default: @code{#f})
15101 HTTP authentication type to use. Set to @code{#f} to disable
15102 authentication (the default). Supported values are @code{"digest"} or
15105 @item @code{users} (default: @code{#f})
15106 If HTTP authentication is enabled (see @code{http-auth}), access will be
15107 restricted to the credentials provided here. To configure users, use a
15108 list of pairs, where the first element of the pair is the username, and
15109 the 2nd element of the pair is the password.
15112 (tailon-configuration-file
15113 (http-auth "basic")
15114 (users '(("user1" . "password1")
15115 ("user2" . "password2"))))
15122 @subsubheading Darkstat Service
15124 Darkstat is a packet sniffer that captures network traffic, calculates
15125 statistics about usage, and serves reports over HTTP.
15127 @defvar {Scheme Variable} darkstat-service-type
15128 This is the service type for the
15129 @uref{https://unix4lyfe.org/darkstat/, darkstat}
15130 service, its value must be a @code{darkstat-configuration} record as in
15134 (service darkstat-service-type
15135 (darkstat-configuration
15136 (interface "eno1")))
15140 @deftp {Data Type} darkstat-configuration
15141 Data type representing the configuration of @command{darkstat}.
15144 @item @code{package} (default: @code{darkstat})
15145 The darkstat package to use.
15147 @item @code{interface}
15148 Capture traffic on the specified network interface.
15150 @item @code{port} (default: @code{"667"})
15151 Bind the web interface to the specified port.
15153 @item @code{bind-address} (default: @code{"127.0.0.1"})
15154 Bind the web interface to the specified address.
15156 @item @code{base} (default: @code{"/"})
15157 Specify the path of the base URL. This can be useful if
15158 @command{darkstat} is accessed via a reverse proxy.
15164 @node Kerberos Services
15165 @subsubsection Kerberos Services
15168 The @code{(gnu services kerberos)} module provides services relating to
15169 the authentication protocol @dfn{Kerberos}.
15171 @subsubheading Krb5 Service
15173 Programs using a Kerberos client library normally
15174 expect a configuration file in @file{/etc/krb5.conf}.
15175 This service generates such a file from a definition provided in the
15176 operating system declaration.
15177 It does not cause any daemon to be started.
15179 No ``keytab'' files are provided by this service---you must explicitly create them.
15180 This service is known to work with the MIT client library, @code{mit-krb5}.
15181 Other implementations have not been tested.
15183 @defvr {Scheme Variable} krb5-service-type
15184 A service type for Kerberos 5 clients.
15188 Here is an example of its use:
15190 (service krb5-service-type
15191 (krb5-configuration
15192 (default-realm "EXAMPLE.COM")
15193 (allow-weak-crypto? #t)
15196 (name "EXAMPLE.COM")
15197 (admin-server "groucho.example.com")
15198 (kdc "karl.example.com"))
15201 (admin-server "kerb-admin.argrx.edu")
15202 (kdc "keys.argrx.edu"))))))
15206 This example provides a Kerberos@tie{}5 client configuration which:
15208 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
15209 of which have distinct administration servers and key distribution centers;
15210 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
15211 specified by clients;
15212 @item Accepts services which only support encryption types known to be weak.
15215 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
15216 Only the most commonly used ones are described here.
15217 For a full list, and more detailed explanation of each, see the MIT
15218 @uref{http://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
15222 @deftp {Data Type} krb5-realm
15223 @cindex realm, kerberos
15226 This field is a string identifying the name of the realm.
15227 A common convention is to use the fully qualified DNS name of your organization,
15228 converted to upper case.
15230 @item @code{admin-server}
15231 This field is a string identifying the host where the administration server is
15235 This field is a string identifying the key distribution center
15240 @deftp {Data Type} krb5-configuration
15243 @item @code{allow-weak-crypto?} (default: @code{#f})
15244 If this flag is @code{#t} then services which only offer encryption algorithms
15245 known to be weak will be accepted.
15247 @item @code{default-realm} (default: @code{#f})
15248 This field should be a string identifying the default Kerberos
15249 realm for the client.
15250 You should set this field to the name of your Kerberos realm.
15251 If this value is @code{#f}
15252 then a realm must be specified with every Kerberos principal when invoking programs
15253 such as @command{kinit}.
15255 @item @code{realms}
15256 This should be a non-empty list of @code{krb5-realm} objects, which clients may
15258 Normally, one of them will have a @code{name} field matching the @code{default-realm}
15264 @subsubheading PAM krb5 Service
15267 The @code{pam-krb5} service allows for login authentication and password
15268 management via Kerberos.
15269 You will need this service if you want PAM enabled applications to authenticate
15270 users using Kerberos.
15272 @defvr {Scheme Variable} pam-krb5-service-type
15273 A service type for the Kerberos 5 PAM module.
15276 @deftp {Data Type} pam-krb5-configuration
15277 Data type representing the configuration of the Kerberos 5 PAM module
15278 This type has the following parameters:
15280 @item @code{pam-krb5} (default: @code{pam-krb5})
15281 The pam-krb5 package to use.
15283 @item @code{minimum-uid} (default: @code{1000})
15284 The smallest user ID for which Kerberos authentications should be attempted.
15285 Local accounts with lower values will silently fail to authenticate.
15291 @subsubsection Web Services
15296 The @code{(gnu services web)} module provides the Apache HTTP Server,
15297 the nginx web server, and also a fastcgi wrapper daemon.
15299 @subsubheading Apache HTTP Server
15301 @deffn {Scheme Variable} httpd-service-type
15302 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
15303 (@dfn{httpd}). The value for this service type is a
15304 @code{https-configuration} record.
15306 A simple example configuration is given below.
15309 (service httpd-service-type
15310 (httpd-configuration
15313 (server-name "www.example.com")
15314 (document-root "/srv/http/www.example.com")))))
15317 Other services can also extend the @code{httpd-service-type} to add to
15321 (simple-service 'my-extra-server httpd-service-type
15325 (list (string-append
15326 "ServerName "www.example.com
15327 DocumentRoot \"/srv/http/www.example.com\"")))))
15331 The details for the @code{httpd-configuration}, @code{httpd-module},
15332 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
15335 @deffn {Data Type} httpd-configuration
15336 This data type represents the configuration for the httpd service.
15339 @item @code{package} (default: @code{httpd})
15340 The httpd package to use.
15342 @item @code{pid-file} (default: @code{"/var/run/httpd"})
15343 The pid file used by the shepherd-service.
15345 @item @code{config} (default: @code{(httpd-config-file)})
15346 The configuration file to use with the httpd service. The default value
15347 is a @code{httpd-config-file} record, but this can also be a different
15348 G-expression that generates a file, for example a @code{plain-file}. A
15349 file outside of the store can also be specified through a string.
15354 @deffn {Data Type} httpd-module
15355 This data type represents a module for the httpd service.
15359 The name of the module.
15362 The file for the module. This can be relative to the httpd package being
15363 used, the absolute location of a file, or a G-expression for a file
15364 within the store, for example @code{(file-append mod-wsgi
15365 "/modules/mod_wsgi.so")}.
15370 @deffn {Data Type} httpd-config-file
15371 This data type represents a configuration file for the httpd service.
15374 @item @code{modules} (default: @code{%default-httpd-modules})
15375 The modules to load. Additional modules can be added here, or loaded by
15376 additional configuration.
15378 @item @code{server-root} (default: @code{httpd})
15379 The @code{ServerRoot} in the configuration file, defaults to the httpd
15380 package. Directives including @code{Include} and @code{LoadModule} are
15381 taken as relative to the server root.
15383 @item @code{server-name} (default: @code{#f})
15384 The @code{ServerName} in the configuration file, used to specify the
15385 request scheme, hostname and port that the server uses to identify
15388 This doesn't need to be set in the server config, and can be specifyed
15389 in virtual hosts. The default is @code{#f} to not specify a
15392 @item @code{document-root} (default: @code{"/srv/http"})
15393 The @code{DocumentRoot} from which files will be served.
15395 @item @code{listen} (default: @code{'("80")})
15396 The list of values for the @code{Listen} directives in the config
15397 file. The value should be a list of strings, when each string can
15398 specify the port number to listen on, and optionally the IP address and
15401 @item @code{pid-file} (default: @code{"/var/run/httpd"})
15402 The @code{PidFile} to use. This should match the @code{pid-file} set in
15403 the @code{httpd-configuration} so that the Shepherd service is
15404 configured correctly.
15406 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
15407 The @code{ErrorLog} to which the server will log errors.
15409 @item @code{user} (default: @code{"httpd"})
15410 The @code{User} which the server will answer requests as.
15412 @item @code{group} (default: @code{"httpd"})
15413 The @code{Group} which the server will answer requests as.
15415 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
15416 A flat list of strings and G-expressions which will be added to the end
15417 of the configuration file.
15419 Any values which the service is extended with will be appended to this
15425 @deffn {Data Type} httpd-virtualhost
15426 This data type represents a virtualhost configuration block for the httpd service.
15428 These should be added to the extra-config for the httpd-service.
15431 (simple-service 'my-extra-server httpd-service-type
15435 (list (string-append
15436 "ServerName "www.example.com
15437 DocumentRoot \"/srv/http/www.example.com\"")))))
15441 @item @code{addresses-and-ports}
15442 The addresses and ports for the @code{VirtualHost} directive.
15444 @item @code{contents}
15445 The contents of the @code{VirtualHost} directive, this should be a list
15446 of strings and G-expressions.
15451 @subsubheading NGINX
15453 @deffn {Scheme Variable} nginx-service-type
15454 Service type for the @uref{https://nginx.org/,NGinx} web server. The
15455 value for this service type is a @code{<nginx-configuration>} record.
15457 A simple example configuration is given below.
15460 (service nginx-service-type
15461 (nginx-configuration
15463 (list (nginx-server-configuration
15464 (server-name '("www.example.com"))
15465 (root "/srv/http/www.example.com"))))))
15468 In addition to adding server blocks to the service configuration
15469 directly, this service can be extended by other services to add server
15470 blocks, as in this example:
15473 (simple-service 'my-extra-server nginx-service-type
15474 (list (nginx-server-configuration
15475 (root "/srv/http/extra-website")
15476 (try-files (list "$uri" "$uri/index.html")))))
15480 At startup, @command{nginx} has not yet read its configuration file, so
15481 it uses a default file to log error messages. If it fails to load its
15482 configuration file, that is where error messages are logged. After the
15483 configuration file is loaded, the default error log file changes as per
15484 configuration. In our case, startup error messages can be found in
15485 @file{/var/run/nginx/logs/error.log}, and after configuration in
15486 @file{/var/log/nginx/error.log}. The second location can be changed
15487 with the @var{log-directory} configuration option.
15489 @deffn {Data Type} nginx-configuration
15490 This data type represents the configuration for NGinx. Some
15491 configuration can be done through this and the other provided record
15492 types, or alternatively, a config file can be provided.
15495 @item @code{nginx} (default: @code{nginx})
15496 The nginx package to use.
15498 @item @code{log-directory} (default: @code{"/var/log/nginx"})
15499 The directory to which NGinx will write log files.
15501 @item @code{run-directory} (default: @code{"/var/run/nginx"})
15502 The directory in which NGinx will create a pid file, and write temporary
15505 @item @code{server-blocks} (default: @code{'()})
15506 A list of @dfn{server blocks} to create in the generated configuration
15507 file, the elements should be of type
15508 @code{<nginx-server-configuration>}.
15510 The following example would setup NGinx to serve @code{www.example.com}
15511 from the @code{/srv/http/www.example.com} directory, without using
15514 (service nginx-service-type
15515 (nginx-configuration
15517 (list (nginx-server-configuration
15518 (server-name '("www.example.com"))
15519 (root "/srv/http/www.example.com"))))))
15522 @item @code{upstream-blocks} (default: @code{'()})
15523 A list of @dfn{upstream blocks} to create in the generated configuration
15524 file, the elements should be of type
15525 @code{<nginx-upstream-configuration>}.
15527 Configuring upstreams through the @code{upstream-blocks} can be useful
15528 when combined with @code{locations} in the
15529 @code{<nginx-server-configuration>} records. The following example
15530 creates a server configuration with one location configuration, that
15531 will proxy requests to a upstream configuration, which will handle
15532 requests with two servers.
15537 (nginx-configuration
15539 (list (nginx-server-configuration
15540 (server-name '("www.example.com"))
15541 (root "/srv/http/www.example.com")
15544 (nginx-location-configuration
15546 (body '("proxy_pass http://server-proxy;"))))))))
15548 (list (nginx-upstream-configuration
15549 (name "server-proxy")
15550 (servers (list "server1.example.com"
15551 "server2.example.com")))))))
15554 @item @code{file} (default: @code{#f})
15555 If a configuration @var{file} is provided, this will be used, rather than
15556 generating a configuration file from the provided @code{log-directory},
15557 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
15558 proper operation, these arguments should match what is in @var{file} to ensure
15559 that the directories are created when the service is activated.
15561 This can be useful if you have an existing configuration file, or it's
15562 not possible to do what is required through the other parts of the
15563 nginx-configuration record.
15565 @item @code{server-names-hash-bucket-size} (default: @code{#f})
15566 Bucket size for the server names hash tables, defaults to @code{#f} to
15567 use the size of the processors cache line.
15569 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
15570 Maximum bucket size for the server names hash tables.
15575 @deftp {Data Type} nginx-server-configuration
15576 Data type representing the configuration of an nginx server block.
15577 This type has the following parameters:
15580 @item @code{listen} (default: @code{'("80" "443 ssl")})
15581 Each @code{listen} directive sets the address and port for IP, or the
15582 path for a UNIX-domain socket on which the server will accept requests.
15583 Both address and port, or only address or only port can be specified.
15584 An address may also be a hostname, for example:
15587 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
15590 @item @code{server-name} (default: @code{(list 'default)})
15591 A list of server names this server represents. @code{'default} represents the
15592 default server for connections matching no other server.
15594 @item @code{root} (default: @code{"/srv/http"})
15595 Root of the website nginx will serve.
15597 @item @code{locations} (default: @code{'()})
15598 A list of @dfn{nginx-location-configuration} or
15599 @dfn{nginx-named-location-configuration} records to use within this
15602 @item @code{index} (default: @code{(list "index.html")})
15603 Index files to look for when clients ask for a directory. If it cannot be found,
15604 Nginx will send the list of files in the directory.
15606 @item @code{try-files} (default: @code{'()})
15607 A list of files whose existence is checked in the specified order.
15608 @code{nginx} will use the first file it finds to process the request.
15610 @item @code{ssl-certificate} (default: @code{#f})
15611 Where to find the certificate for secure connections. Set it to @code{#f} if
15612 you don't have a certificate or you don't want to use HTTPS.
15614 @item @code{ssl-certificate-key} (default: @code{#f})
15615 Where to find the private key for secure connections. Set it to @code{#f} if
15616 you don't have a key or you don't want to use HTTPS.
15618 @item @code{server-tokens?} (default: @code{#f})
15619 Whether the server should add its configuration to response.
15621 @item @code{raw-content} (default: @code{'()})
15622 A list of raw lines added to the server block.
15627 @deftp {Data Type} nginx-upstream-configuration
15628 Data type representing the configuration of an nginx @code{upstream}
15629 block. This type has the following parameters:
15633 Name for this group of servers.
15635 @item @code{servers}
15636 Specify the addresses of the servers in the group. The address can be
15637 specified as a IP address (e.g. @samp{127.0.0.1}), domain name
15638 (e.g. @samp{backend1.example.com}) or a path to a UNIX socket using the
15639 prefix @samp{unix:}. For addresses using an IP address or domain name,
15640 the default port is 80, and a different port can be specified
15646 @deftp {Data Type} nginx-location-configuration
15647 Data type representing the configuration of an nginx @code{location}
15648 block. This type has the following parameters:
15652 URI which this location block matches.
15654 @anchor{nginx-location-configuration body}
15656 Body of the location block, specified as a list of strings. This can contain
15658 configuration directives. For example, to pass requests to a upstream
15659 server group defined using an @code{nginx-upstream-configuration} block,
15660 the following directive would be specified in the body @samp{(list "proxy_pass
15661 http://upstream-name;")}.
15666 @deftp {Data Type} nginx-named-location-configuration
15667 Data type representing the configuration of an nginx named location
15668 block. Named location blocks are used for request redirection, and not
15669 used for regular request processing. This type has the following
15674 Name to identify this location block.
15677 @xref{nginx-location-configuration body}, as the body for named location
15678 blocks can be used in a similar way to the
15679 @code{nginx-location-configuration body}. One restriction is that the
15680 body of a named location block cannot contain location blocks.
15687 FastCGI is an interface between the front-end and the back-end of a web
15688 service. It is a somewhat legacy facility; new web services should
15689 generally just talk HTTP between the front-end and the back-end.
15690 However there are a number of back-end services such as PHP or the
15691 optimized HTTP Git repository access that use FastCGI, so we have
15692 support for it in Guix.
15694 To use FastCGI, you configure the front-end web server (e.g., nginx) to
15695 dispatch some subset of its requests to the fastcgi backend, which
15696 listens on a local TCP or UNIX socket. There is an intermediary
15697 @code{fcgiwrap} program that sits between the actual backend process and
15698 the web server. The front-end indicates which backend program to run,
15699 passing that information to the @code{fcgiwrap} process.
15701 @defvr {Scheme Variable} fcgiwrap-service-type
15702 A service type for the @code{fcgiwrap} FastCGI proxy.
15705 @deftp {Data Type} fcgiwrap-configuration
15706 Data type representing the configuration of the @code{fcgiwrap} serice.
15707 This type has the following parameters:
15709 @item @code{package} (default: @code{fcgiwrap})
15710 The fcgiwrap package to use.
15712 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
15713 The socket on which the @code{fcgiwrap} process should listen, as a
15714 string. Valid @var{socket} values include
15715 @code{unix:@var{/path/to/unix/socket}},
15716 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
15717 @code{tcp6:[@var{ipv6_addr}]:port}.
15719 @item @code{user} (default: @code{fcgiwrap})
15720 @itemx @code{group} (default: @code{fcgiwrap})
15721 The user and group names, as strings, under which to run the
15722 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
15723 the user asks for the specific user or group names @code{fcgiwrap} that
15724 the corresponding user and/or group is present on the system.
15726 It is possible to configure a FastCGI-backed web service to pass HTTP
15727 authentication information from the front-end to the back-end, and to
15728 allow @code{fcgiwrap} to run the back-end process as a corresponding
15729 local user. To enable this capability on the back-end., run
15730 @code{fcgiwrap} as the @code{root} user and group. Note that this
15731 capability also has to be configured on the front-end as well.
15736 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
15737 with some additional features useful for sites of any size.
15739 These features include:
15741 @item Adaptive process spawning
15742 @item Basic statistics (similar to Apache's mod_status)
15743 @item Advanced process management with graceful stop/start
15744 @item Ability to start workers with different uid/gid/chroot/environment
15745 and different php.ini (replaces safe_mode)
15746 @item Stdout & stderr logging
15747 @item Emergency restart in case of accidental opcode cache destruction
15748 @item Accelerated upload support
15749 @item Support for a "slowlog"
15750 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
15751 a special function to finish request & flush all data while continuing to do
15752 something time-consuming (video converting, stats processing, etc.)
15756 @defvr {Scheme Variable} php-fpm-service-type
15757 A Service type for @code{php-fpm}.
15760 @deftp {Data Type} php-fpm-configuration
15761 Data Type for php-fpm service configuration.
15763 @item @code{php} (default: @code{php})
15764 The php package to use.
15765 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
15766 The address on which to accept FastCGI requests. Valid syntaxes are:
15768 @item @code{"ip.add.re.ss:port"}
15769 Listen on a TCP socket to a specific address on a specific port.
15770 @item @code{"port"}
15771 Listen on a TCP socket to all addresses on a specific port.
15772 @item @code{"/path/to/unix/socket"}
15773 Listen on a unix socket.
15776 @item @code{user} (default: @code{php-fpm})
15777 User who will own the php worker processes.
15778 @item @code{group} (default: @code{php-fpm})
15779 Group of the worker processes.
15780 @item @code{socket-user} (default: @code{php-fpm})
15781 User who can speak to the php-fpm socket.
15782 @item @code{socket-group} (default: @code{php-fpm})
15783 Group that can speak to the php-fpm socket.
15784 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
15785 The process id of the php-fpm process is written to this file
15786 once the service has started.
15787 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
15788 Log for the php-fpm master process.
15789 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
15790 Detailed settings for the php-fpm process manager.
15793 @item @code{<php-fpm-dynamic-process-manager-configuration>}
15794 @item @code{<php-fpm-static-process-manager-configuration>}
15795 @item @code{<php-fpm-on-demand-process-manager-configuration>}
15797 @item @code{display-errors} (default @code{#f})
15798 Determines whether php errors and warning should be sent to clients
15799 and displayed in their browsers.
15800 This is useful for local php development, but a security risk for public sites,
15801 as error messages can reveal passwords and personal data.
15802 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
15803 This file will log the @code{stderr} outputs of php worker processes.
15804 Can be set to @code{#f} to disable logging.
15805 @item @code{file} (default @code{#f})
15806 An optional override of the whole configuration.
15807 You can use the @code{mixed-text-file} function or an absolute filepath for it.
15811 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
15812 Data Type for the @code{dynamic} php-fpm process manager. With the
15813 @code{dynamic} process manager, spare worker processes are kept around
15814 based on it's configured limits.
15816 @item @code{max-children} (default: @code{5})
15817 Maximum of worker processes.
15818 @item @code{start-servers} (default: @code{2})
15819 How many worker processes should be started on start-up.
15820 @item @code{min-spare-servers} (default: @code{1})
15821 How many spare worker processes should be kept around at minimum.
15822 @item @code{max-spare-servers} (default: @code{3})
15823 How many spare worker processes should be kept around at maximum.
15827 @deftp {Data type} php-fpm-static-process-manager-configuration
15828 Data Type for the @code{static} php-fpm process manager. With the
15829 @code{static} process manager, an unchanging number of worker processes
15832 @item @code{max-children} (default: @code{5})
15833 Maximum of worker processes.
15837 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
15838 Data Type for the @code{on-demand} php-fpm process manager. With the
15839 @code{on-demand} process manager, worker processes are only created as
15842 @item @code{max-children} (default: @code{5})
15843 Maximum of worker processes.
15844 @item @code{process-idle-timeout} (default: @code{10})
15845 The time in seconds after which a process with no requests is killed.
15850 @deffn {Scheme Procedure} nginx-php-fpm-location @
15851 [#:nginx-package nginx] @
15852 [socket (string-append "/var/run/php" @
15853 (version-major (package-version php)) @
15855 A helper function to quickly add php to an @code{nginx-server-configuration}.
15858 A simple services setup for nginx with php can look like this:
15860 (services (cons* (dhcp-client-service)
15861 (service php-fpm-service-type)
15862 (service nginx-service-type
15863 (nginx-server-configuration
15864 (server-name '("example.com"))
15865 (root "/srv/http/")
15867 (list (nginx-php-location)))
15869 (ssl-certificate #f)
15870 (ssl-certificate-key #f)))
15874 @cindex cat-avatar-generator
15875 The cat avatar generator is a simple service to demonstrate the use of php-fpm
15876 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
15877 the hash of a user's email address.
15879 @deffn {Scheme Procedure} cat-avatar-generator-serice @
15880 [#:cache-dir "/var/cache/cat-avatar-generator"] @
15881 [#:package cat-avatar-generator] @
15882 [#:configuration (nginx-server-configuration)]
15883 Returns an nginx-server-configuration that inherits @code{configuration}. It
15884 extends the nginx configuration to add a server block that serves @code{package},
15885 a version of cat-avatar-generator. During execution, cat-avatar-generator will
15886 be able to use @code{cache-dir} as its cache directory.
15889 A simple setup for cat-avatar-generator can look like this:
15891 (services (cons* (cat-avatar-generator-service
15893 (nginx-server-configuration
15894 (server-name '("example.com"))))
15899 @node Certificate Services
15900 @subsubsection Certificate Services
15903 @cindex HTTP, HTTPS
15904 @cindex Let's Encrypt
15905 @cindex TLS certificates
15906 The @code{(gnu services certbot)} module provides a service to
15907 automatically obtain a valid TLS certificate from the Let's Encrypt
15908 certificate authority. These certificates can then be used to serve
15909 content securely over HTTPS or other TLS-based protocols, with the
15910 knowledge that the client will be able to verify the server's
15913 @url{https://letsencrypt.org/, Let's Encrypt} provides the
15914 @code{certbot} tool to automate the certification process. This tool
15915 first securely generates a key on the server. It then makes a request
15916 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
15917 checks that the request originates from the host in question by using a
15918 challenge-response protocol, requiring the server to provide its
15919 response over HTTP. If that protocol completes successfully, the CA
15920 signs the key, resulting in a certificate. That certificate is valid
15921 for a limited period of time, and therefore to continue to provide TLS
15922 services, the server needs to periodically ask the CA to renew its
15925 The certbot service automates this process: the initial key
15926 generation, the initial certification request to the Let's Encrypt
15927 service, the web server challenge/response integration, writing the
15928 certificate to disk, the automated periodic renewals, and the deployment
15929 tasks associated with the renewal (e.g. reloading services, copying keys
15930 with different permissions).
15932 Certbot is run twice a day, at a random minute within the hour. It
15933 won't do anything until your certificates are due for renewal or
15934 revoked, but running it regularly would give your service a chance of
15935 staying online in case a Let's Encrypt-initiated revocation happened for
15938 By using this service, you agree to the ACME Subscriber Agreement, which
15939 can be found there:
15940 @url{https://acme-v01.api.letsencrypt.org/directory}.
15942 @defvr {Scheme Variable} certbot-service-type
15943 A service type for the @code{certbot} Let's Encrypt client. Its value
15944 must be a @code{certbot-configuration} record as in this example:
15947 (define %nginx-deploy-hook
15949 "nginx-deploy-hook"
15950 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
15951 (kill pid SIGHUP))))
15953 (service certbot-service-type
15954 (certbot-configuration
15955 (email "foo@@example.net")
15958 (certificate-configuration
15959 (domains '("example.net" "www.example.net"))
15960 (deploy-hook %nginx-deploy-hook))
15961 (certificate-configuration
15962 (domains '("bar.example.net")))))))
15965 See below for details about @code{certbot-configuration}.
15968 @deftp {Data Type} certbot-configuration
15969 Data type representing the configuration of the @code{certbot} service.
15970 This type has the following parameters:
15973 @item @code{package} (default: @code{certbot})
15974 The certbot package to use.
15976 @item @code{webroot} (default: @code{/var/www})
15977 The directory from which to serve the Let's Encrypt challenge/response
15980 @item @code{certificates} (default: @code{()})
15981 A list of @code{certificates-configuration}s for which to generate
15982 certificates and request signatures. Each certificate has a @code{name}
15983 and several @code{domains}.
15986 Mandatory email used for registration, recovery contact, and important
15987 account notifications.
15989 @item @code{rsa-key-size} (default: @code{2048})
15990 Size of the RSA key.
15992 @item @code{default-location} (default: @i{see below})
15993 The default @code{nginx-location-configuration}. Because @code{certbot}
15994 needs to be able to serve challenges and responses, it needs to be able
15995 to run a web server. It does so by extending the @code{nginx} web
15996 service with an @code{nginx-server-configuration} listening on the
15997 @var{domains} on port 80, and which has a
15998 @code{nginx-location-configuration} for the @code{/.well-known/} URI
15999 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
16000 these nginx configuration data types.
16002 Requests to other URL paths will be matched by the
16003 @code{default-location}, which if present is added to all
16004 @code{nginx-server-configuration}s.
16006 By default, the @code{default-location} will issue a redirect from
16007 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
16008 you to define what to serve on your site via @code{https}.
16010 Pass @code{#f} to not issue a default location.
16014 @deftp {Data Type} certificate-configuration
16015 Data type representing the configuration of a certificate.
16016 This type has the following parameters:
16019 @item @code{name} (default: @i{see below})
16020 This name is used by Certbot for housekeeping and in file paths; it
16021 doesn't affect the content of the certificate itself. To see
16022 certificate names, run @code{certbot certificates}.
16024 Its default is the first provided domain.
16026 @item @code{domains} (default: @code{()})
16027 The first domain provided will be the subject CN of the certificate, and
16028 all domains will be Subject Alternative Names on the certificate.
16030 @item @code{deploy-hook} (default: @code{#f})
16031 Command to be run in a shell once for each successfully issued
16032 certificate. For this command, the shell variable
16033 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
16034 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
16035 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
16036 contain a space-delimited list of renewed certificate domains (for
16037 example, @samp{"example.com www.example.com"}.
16042 For each @code{certificate-configuration}, the certificate is saved to
16043 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
16044 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
16046 @subsubsection DNS Services
16047 @cindex DNS (domain name system)
16048 @cindex domain name system (DNS)
16050 The @code{(gnu services dns)} module provides services related to the
16051 @dfn{domain name system} (DNS). It provides a server service for hosting
16052 an @emph{authoritative} DNS server for multiple zones, slave or master.
16053 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}.
16055 An example configuration of an authoritative server for two zones, one master
16059 (define-zone-entries example.org.zone
16060 ;; Name TTL Class Type Data
16061 ("@@" "" "IN" "A" "127.0.0.1")
16062 ("@@" "" "IN" "NS" "ns")
16063 ("ns" "" "IN" "A" "127.0.0.1"))
16065 (define master-zone
16066 (knot-zone-configuration
16067 (domain "example.org")
16069 (origin "example.org")
16070 (entries example.org.zone)))))
16073 (knot-zone-configuration
16074 (domain "plop.org")
16075 (dnssec-policy "default")
16076 (master (list "plop-master"))))
16078 (define plop-master
16079 (knot-remote-configuration
16081 (address (list "208.76.58.171"))))
16085 (services (cons* (service knot-service-type
16086 (knot-configuration
16087 (remotes (list plop-master))
16088 (zones (list master-zone slave-zone))))
16093 @deffn {Scheme Variable} knot-service-type
16094 This is the type for the Knot DNS server.
16096 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
16097 zones, that is to say domain names you would buy from a registrar. This server
16098 is not a resolver, meaning that it can only resolve names for which it is
16099 authoritative. This server can be configured to serve zones as a master server
16100 or a slave server as a per-zone basis. Slave zones will get their data from
16101 masters, and will serve it as an authoritative server. From the point of view
16102 of a resolver, there is no difference between master and slave.
16104 The following data types are used to configure the Knot DNS server:
16107 @deftp {Data Type} knot-key-configuration
16108 Data type representing a key.
16109 This type has the following parameters:
16112 @item @code{id} (default: @code{""})
16113 An identifier for other configuration fields to refer to this key. IDs must
16114 be unique and must not be empty.
16116 @item @code{algorithm} (default: @code{#f})
16117 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
16118 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
16119 and @code{'hmac-sha512}.
16121 @item @code{secret} (default: @code{""})
16122 The secret key itself.
16127 @deftp {Data Type} knot-acl-configuration
16128 Data type representing an Access Control List (ACL) configuration.
16129 This type has the following parameters:
16132 @item @code{id} (default: @code{""})
16133 An identifier for ether configuration fields to refer to this key. IDs must be
16134 unique and must not be empty.
16136 @item @code{address} (default: @code{'()})
16137 An ordered list of IP addresses, network subnets, or network ranges represented
16138 with strings. The query must match one of them. Empty value means that
16139 address match is not required.
16141 @item @code{key} (default: @code{'()})
16142 An ordered list of references to keys represented with strings. The string
16143 must match a key ID defined in a @code{knot-key-configuration}. No key means
16144 that a key is not require to match that ACL.
16146 @item @code{action} (default: @code{'()})
16147 An ordered list of actions that are permitted or forbidden by this ACL. Possible
16148 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
16149 and @code{'update}.
16151 @item @code{deny?} (default: @code{#f})
16152 When true, the ACL defines restrictions. Listed actions are forbidden. When
16153 false, listed actions are allowed.
16158 @deftp {Data Type} zone-entry
16159 Data type represnting a record entry in a zone file.
16160 This type has the following parameters:
16163 @item @code{name} (default: @code{"@@"})
16164 The name of the record. @code{"@@"} refers to the origin of the zone. Names
16165 are relative to the origin of the zone. For example, in the @code{example.org}
16166 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
16167 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
16168 refers to @code{ns.example.org}.
16170 @item @code{ttl} (default: @code{""})
16171 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
16173 @item @code{class} (default: @code{"IN"})
16174 The class of the record. Knot currently supports only @code{"IN"} and
16175 partially @code{"CH"}.
16177 @item @code{type} (default: @code{"A"})
16178 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
16179 address), NS (Name Server) and MX (Mail eXchange). Many other types are
16182 @item @code{data} (default: @code{""})
16183 The data contained in the record. For instance an IP address associated with
16184 an A record, or a domain name associated with an NS record. Remember that
16185 domain names are relative to the origin unless they end with a dot.
16190 @deftp {Data Type} zone-file
16191 Data type representing the content of a zone file.
16192 This type has the following parameters:
16195 @item @code{entries} (default: @code{'()})
16196 The list of entries. The SOA record is taken care of, so you don't need to
16197 put it in the list of entries. This list should probably contain an entry
16198 for your primary authoritative DNS server. Other than using a list of entries
16199 directly, you can use @code{define-zone-entries} to define a object containing
16200 the list of entries more easily, that you can later pass to the @code{entries}
16201 field of the @code{zone-file}.
16203 @item @code{origin} (default: @code{""})
16204 The name of your zone. This parameter cannot be empty.
16206 @item @code{ns} (default: @code{"ns"})
16207 The domain of your primary authoritative DNS server. The name is relative to
16208 the origin, unless it ends with a dot. It is mandatory that this primary
16209 DNS server corresponds to an NS record in the zone and that it is associated
16210 to an IP address in the list of entries.
16212 @item @code{mail} (default: @code{"hostmaster"})
16213 An email address people can contact you at, as the owner of the zone. This
16214 is translated as @code{<mail>@@<origin>}.
16216 @item @code{serial} (default: @code{1})
16217 The serial number of the zone. As this is used to keep track of changes by
16218 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
16219 Always increment it when you make a change in your zone.
16221 @item @code{refresh} (default: @code{(* 2 24 3600)})
16222 The frequency at which slaves will do a zone transfer. This value is a number
16223 of seconds. It can be computed by multiplications or with
16224 @code{(string->duration)}.
16226 @item @code{retry} (default: @code{(* 15 60)})
16227 The period after which a slave will retry to contact its master when it fails
16228 to do so a first time.
16230 @item @code{expiry} (default: @code{(* 14 24 3600)})
16231 Default TTL of records. Existing records are considered correct for at most
16232 this amount of time. After this period, resolvers will invalidate their cache
16233 and check again that it still exists.
16235 @item @code{nx} (default: @code{3600})
16236 Default TTL of inexistant records. This delay is usually short because you want
16237 your new domains to reach everyone quickly.
16242 @deftp {Data Type} knot-remote-configuration
16243 Data type representing a remote configuration.
16244 This type has the following parameters:
16247 @item @code{id} (default: @code{""})
16248 An identifier for other configuration fields to refer to this remote. IDs must
16249 be unique and must not be empty.
16251 @item @code{address} (default: @code{'()})
16252 An ordered list of destination IP addresses. Addresses are tried in sequence.
16253 An optional port can be given with the @@ separator. For instance:
16254 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
16256 @item @code{via} (default: @code{'()})
16257 An ordered list of source IP addresses. An empty list will have Knot choose
16258 an appropriate source IP. An optional port can be given with the @@ separator.
16259 The default is to choose at random.
16261 @item @code{key} (default: @code{#f})
16262 A reference to a key, that is a string containing the identifier of a key
16263 defined in a @code{knot-key-configuration} field.
16268 @deftp {Data Type} knot-keystore-configuration
16269 Data type representing a keystore to hold dnssec keys.
16270 This type has the following parameters:
16273 @item @code{id} (default: @code{""})
16274 The id of the keystore. It must not be empty.
16276 @item @code{backend} (default: @code{'pem})
16277 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
16279 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
16280 The configuration string of the backend. An example for the PKCS#11 is:
16281 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
16282 For the pem backend, the string reprensents a path in the file system.
16287 @deftp {Data Type} knot-policy-configuration
16288 Data type representing a dnssec policy. Knot DNS is able to automatically
16289 sign your zones. It can either generate and manage your keys automatically or
16290 use keys that you generate.
16292 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
16293 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
16294 zone. In order to be trusted, the KSK needs to be present in the parent zone
16295 (usually a top-level domain). If your registrar supports dnssec, you will
16296 have to send them your KSK's hash so they can add a DS record in their zone.
16297 This is not automated and need to be done each time you change your KSK.
16299 The policy also defines the lifetime of keys. Usually, ZSK can be changed
16300 easily and use weaker cryptographic functions (they use lower parameters) in
16301 order to sign records quickly, so they are changed often. The KSK however
16302 requires manual interaction with the registrar, so they are changed less often
16303 and use stronger parameters because they sign only one record.
16305 This type has the following parameters:
16308 @item @code{id} (default: @code{""})
16309 The id of the policy. It must not be empty.
16311 @item @code{keystore} (default: @code{"default"})
16312 A reference to a keystore, that is a string containing the identifier of a
16313 keystore defined in a @code{knot-keystore-configuration} field. The
16314 @code{"default"} identifier means the default keystore (a kasp database that
16315 was setup by this service).
16317 @item @code{manual?} (default: @code{#f})
16318 Whether the key management is manual or automatic.
16320 @item @code{single-type-signing?} (default: @code{#f})
16321 When @code{#t}, use the Single-Type Signing Scheme.
16323 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
16324 An algorithm of signing keys and issued signatures.
16326 @item @code{ksk-size} (default: @code{256})
16327 The length of the KSK. Note that this value is correct for the default
16328 algorithm, but would be unsecure for other algorithms.
16330 @item @code{zsk-size} (default: @code{256})
16331 The length of the ZSK. Note that this value is correct for the default
16332 algorithm, but would be unsecure for other algorithms.
16334 @item @code{dnskey-ttl} (default: @code{'default})
16335 The TTL value for DNSKEY records added into zone apex. The special
16336 @code{'default} value means same as the zone SOA TTL.
16338 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
16339 The period between ZSK publication and the next rollover initiation.
16341 @item @code{propagation-delay} (default: @code{(* 24 3600)})
16342 An extra delay added for each key rollover step. This value should be high
16343 enough to cover propagation of data from the master server to all slaves.
16345 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
16346 A validity period of newly issued signatures.
16348 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
16349 A period how long before a signature expiration the signature will be refreshed.
16351 @item @code{nsec3?} (default: @code{#f})
16352 When @code{#t}, NSEC3 will be used instead of NSEC.
16354 @item @code{nsec3-iterations} (default: @code{5})
16355 The number of additional times the hashing is performed.
16357 @item @code{nsec3-salt-length} (default: @code{8})
16358 The length of a salt field in octets, which is appended to the original owner
16359 name before hashing.
16361 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
16362 The validity period of newly issued salt field.
16367 @deftp {Data Type} knot-zone-configuration
16368 Data type representing a zone served by Knot.
16369 This type has the following parameters:
16372 @item @code{domain} (default: @code{""})
16373 The domain served by this configuration. It must not be empty.
16375 @item @code{file} (default: @code{""})
16376 The file where this zone is saved. This parameter is ignored by master zones.
16377 Empty means default location that depends on the domain name.
16379 @item @code{zone} (default: @code{(zone-file)})
16380 The content of the zone file. This parameter is ignored by slave zones. It
16381 must contain a zone-file record.
16383 @item @code{master} (default: @code{'()})
16384 A list of master remotes. When empty, this zone is a master. When set, this
16385 zone is a slave. This is a list of remotes identifiers.
16387 @item @code{ddns-master} (default: @code{#f})
16388 The main master. When empty, it defaults to the first master in the list of
16391 @item @code{notify} (default: @code{'()})
16392 A list of slave remote identifiers.
16394 @item @code{acl} (default: @code{'()})
16395 A list of acl identifiers.
16397 @item @code{semantic-checks?} (default: @code{#f})
16398 When set, this adds more semantic checks to the zone.
16400 @item @code{disable-any?} (default: @code{#f})
16401 When set, this forbids queries of the ANY type.
16403 @item @code{zonefile-sync} (default: @code{0})
16404 The delay between a modification in memory and on disk. 0 means immediate
16407 @item @code{serial-policy} (default: @code{'increment})
16408 A policy between @code{'increment} and @code{'unixtime}.
16413 @deftp {Data Type} knot-configuration
16414 Data type representing the Knot configuration.
16415 This type has the following parameters:
16418 @item @code{knot} (default: @code{knot})
16421 @item @code{run-directory} (default: @code{"/var/run/knot"})
16422 The run directory. This directory will be used for pid file and sockets.
16424 @item @code{listen-v4} (default: @code{"0.0.0.0"})
16425 An ip address on which to listen.
16427 @item @code{listen-v6} (default: @code{"::"})
16428 An ip address on which to listen.
16430 @item @code{listen-port} (default: @code{53})
16431 A port on which to listen.
16433 @item @code{keys} (default: @code{'()})
16434 The list of knot-key-configuration used by this configuration.
16436 @item @code{acls} (default: @code{'()})
16437 The list of knot-acl-configuration used by this configuration.
16439 @item @code{remotes} (default: @code{'()})
16440 The list of knot-remote-configuration used by this configuration.
16442 @item @code{zones} (default: @code{'()})
16443 The list of knot-zone-configuration used by this configuration.
16450 @subsubsection VPN Services
16451 @cindex VPN (virtual private network)
16452 @cindex virtual private network (VPN)
16454 The @code{(gnu services vpn)} module provides services related to
16455 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
16456 your machine to connect to a VPN, and a @emph{servire} service for your machine
16457 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
16459 @deffn {Scheme Procedure} openvpn-client-service @
16460 [#:config (openvpn-client-configuration)]
16462 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
16465 @deffn {Scheme Procedure} openvpn-server-service @
16466 [#:config (openvpn-server-configuration)]
16468 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
16470 Both can be run simultaneously.
16473 @c %automatically generated documentation
16475 Available @code{openvpn-client-configuration} fields are:
16477 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
16478 The OpenVPN package.
16482 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
16483 The OpenVPN pid file.
16485 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
16489 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
16490 The protocol (UDP or TCP) used to open a channel between clients and
16493 Defaults to @samp{udp}.
16497 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
16498 The device type used to represent the VPN connection.
16500 Defaults to @samp{tun}.
16504 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
16505 The certificate authority to check connections against.
16507 Defaults to @samp{"/etc/openvpn/ca.crt"}.
16511 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
16512 The certificate of the machine the daemon is running on. It should be
16513 signed by the authority given in @code{ca}.
16515 Defaults to @samp{"/etc/openvpn/client.crt"}.
16519 @deftypevr {@code{openvpn-client-configuration} parameter} string key
16520 The key of the machine the daemon is running on. It must be the key whose
16521 certificate is @code{cert}.
16523 Defaults to @samp{"/etc/openvpn/client.key"}.
16527 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
16528 Whether to use the lzo compression algorithm.
16530 Defaults to @samp{#t}.
16534 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
16535 Don't re-read key files across SIGUSR1 or --ping-restart.
16537 Defaults to @samp{#t}.
16541 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
16542 Don't close and reopen TUN/TAP device or run up/down scripts across
16543 SIGUSR1 or --ping-restart restarts.
16545 Defaults to @samp{#t}.
16549 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
16552 Defaults to @samp{3}.
16556 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
16557 Add an additional layer of HMAC authentication on top of the TLS control
16558 channel to protect against DoS attacks.
16560 Defaults to @samp{#f}.
16564 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
16565 Whether to check the server certificate has server usage extension.
16567 Defaults to @samp{#t}.
16571 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
16572 Bind to a specific local port number.
16574 Defaults to @samp{#f}.
16578 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
16579 Retry resolving server address.
16581 Defaults to @samp{#t}.
16585 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
16586 A list of remote servers to connect to.
16588 Defaults to @samp{()}.
16590 Available @code{openvpn-remote-configuration} fields are:
16592 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
16595 Defaults to @samp{"my-server"}.
16599 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
16600 Port number the server listens to.
16602 Defaults to @samp{1194}.
16607 @c %end of automatic openvpn-client documentation
16609 @c %automatically generated documentation
16611 Available @code{openvpn-server-configuration} fields are:
16613 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
16614 The OpenVPN package.
16618 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
16619 The OpenVPN pid file.
16621 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
16625 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
16626 The protocol (UDP or TCP) used to open a channel between clients and
16629 Defaults to @samp{udp}.
16633 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
16634 The device type used to represent the VPN connection.
16636 Defaults to @samp{tun}.
16640 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
16641 The certificate authority to check connections against.
16643 Defaults to @samp{"/etc/openvpn/ca.crt"}.
16647 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
16648 The certificate of the machine the daemon is running on. It should be
16649 signed by the authority given in @code{ca}.
16651 Defaults to @samp{"/etc/openvpn/client.crt"}.
16655 @deftypevr {@code{openvpn-server-configuration} parameter} string key
16656 The key of the machine the daemon is running on. It must be the key whose
16657 certificate is @code{cert}.
16659 Defaults to @samp{"/etc/openvpn/client.key"}.
16663 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
16664 Whether to use the lzo compression algorithm.
16666 Defaults to @samp{#t}.
16670 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
16671 Don't re-read key files across SIGUSR1 or --ping-restart.
16673 Defaults to @samp{#t}.
16677 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
16678 Don't close and reopen TUN/TAP device or run up/down scripts across
16679 SIGUSR1 or --ping-restart restarts.
16681 Defaults to @samp{#t}.
16685 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
16688 Defaults to @samp{3}.
16692 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
16693 Add an additional layer of HMAC authentication on top of the TLS control
16694 channel to protect against DoS attacks.
16696 Defaults to @samp{#f}.
16700 @deftypevr {@code{openvpn-server-configuration} parameter} number port
16701 Specifies the port number on which the server listens.
16703 Defaults to @samp{1194}.
16707 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
16708 An ip and mask specifying the subnet inside the virtual network.
16710 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
16714 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
16715 A CIDR notation specifying the IPv6 subnet inside the virtual network.
16717 Defaults to @samp{#f}.
16721 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
16722 The Diffie-Hellman parameters file.
16724 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
16728 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
16729 The file that records client IPs.
16731 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
16735 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
16736 When true, the server will act as a gateway for its clients.
16738 Defaults to @samp{#f}.
16742 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
16743 When true, clients are allowed to talk to each other inside the VPN.
16745 Defaults to @samp{#f}.
16749 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
16750 Causes ping-like messages to be sent back and forth over the link so
16751 that each side knows when the other side has gone down. @code{keepalive}
16752 requires a pair. The first element is the period of the ping sending,
16753 and the second element is the timeout before considering the other side
16758 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
16759 The maximum number of clients.
16761 Defaults to @samp{100}.
16765 @deftypevr {@code{openvpn-server-configuration} parameter} string status
16766 The status file. This file shows a small report on current connection.
16767 It is truncated and rewritten every minute.
16769 Defaults to @samp{"/var/run/openvpn/status"}.
16773 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
16774 The list of configuration for some clients.
16776 Defaults to @samp{()}.
16778 Available @code{openvpn-ccd-configuration} fields are:
16780 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
16783 Defaults to @samp{"client"}.
16787 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
16790 Defaults to @samp{#f}.
16794 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
16797 Defaults to @samp{#f}.
16804 @c %end of automatic openvpn-server documentation
16807 @node Network File System
16808 @subsubsection Network File System
16811 The @code{(gnu services nfs)} module provides the following services,
16812 which are most commonly used in relation to mounting or exporting
16813 directory trees as @dfn{network file systems} (NFS).
16815 @subsubheading RPC Bind Service
16818 The RPC Bind service provides a facility to map program numbers into
16819 universal addresses.
16820 Many NFS related services use this facility. Hence it is automatically
16821 started when a dependent service starts.
16823 @defvr {Scheme Variable} rpcbind-service-type
16824 A service type for the RPC portmapper daemon.
16828 @deftp {Data Type} rpcbind-configuration
16829 Data type representing the configuration of the RPC Bind Service.
16830 This type has the following parameters:
16832 @item @code{rpcbind} (default: @code{rpcbind})
16833 The rpcbind package to use.
16835 @item @code{warm-start?} (default: @code{#t})
16836 If this parameter is @code{#t}, then the daemon will read a
16837 state file on startup thus reloading state information saved by a previous
16843 @subsubheading Pipefs Pseudo File System
16847 The pipefs file system is used to transfer NFS related data
16848 between the kernel and user space programs.
16850 @defvr {Scheme Variable} pipefs-service-type
16851 A service type for the pipefs pseudo file system.
16854 @deftp {Data Type} pipefs-configuration
16855 Data type representing the configuration of the pipefs pseudo file system service.
16856 This type has the following parameters:
16858 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
16859 The directory to which the file system is to be attached.
16864 @subsubheading GSS Daemon Service
16867 @cindex global security system
16869 The @dfn{global security system} (GSS) daemon provides strong security for RPC
16871 Before exchanging RPC requests an RPC client must establish a security
16872 context. Typically this is done using the Kerberos command @command{kinit}
16873 or automatically at login time using PAM services (@pxref{Kerberos Services}).
16875 @defvr {Scheme Variable} gss-service-type
16876 A service type for the Global Security System (GSS) daemon.
16879 @deftp {Data Type} gss-configuration
16880 Data type representing the configuration of the GSS daemon service.
16881 This type has the following parameters:
16883 @item @code{nfs-utils} (default: @code{nfs-utils})
16884 The package in which the @command{rpc.gssd} command is to be found.
16886 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
16887 The directory where the pipefs file system is mounted.
16893 @subsubheading IDMAP Daemon Service
16895 @cindex name mapper
16897 The idmap daemon service provides mapping between user IDs and user names.
16898 Typically it is required in order to access file systems mounted via NFSv4.
16900 @defvr {Scheme Variable} idmap-service-type
16901 A service type for the Identity Mapper (IDMAP) daemon.
16904 @deftp {Data Type} idmap-configuration
16905 Data type representing the configuration of the IDMAP daemon service.
16906 This type has the following parameters:
16908 @item @code{nfs-utils} (default: @code{nfs-utils})
16909 The package in which the @command{rpc.idmapd} command is to be found.
16911 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
16912 The directory where the pipefs file system is mounted.
16914 @item @code{domain} (default: @code{#f})
16915 The local NFSv4 domain name.
16916 This must be a string or @code{#f}.
16917 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
16922 @node Continuous Integration
16923 @subsubsection Continuous Integration
16925 @cindex continuous integration
16926 @uref{https://notabug.org/mthl/cuirass, Cuirass} is a continuous
16927 integration tool for Guix. It can be used both for development and for
16928 providing substitutes to others (@pxref{Substitutes}).
16930 The @code{(gnu services cuirass)} module provides the following service.
16932 @defvr {Scheme Procedure} cuirass-service-type
16933 The type of the Cuirass service. Its value must be a
16934 @code{cuirass-configuration} object, as described below.
16937 To add build jobs, you have to set the @code{specifications} field of
16938 the configuration. Here is an example of a service defining a build job
16939 based on a specification that can be found in Cuirass source tree. This
16940 service polls the Guix repository and builds a subset of the Guix
16941 packages, as prescribed in the @file{gnu-system.scm} example spec:
16944 (let ((spec #~((#:name . "guix")
16945 (#:url . "git://git.savannah.gnu.org/guix.git")
16946 (#:load-path . ".")
16947 (#:file . "build-aux/cuirass/gnu-system.scm")
16948 (#:proc . cuirass-jobs)
16949 (#:arguments (subset . "hello"))
16950 (#:branch . "master"))))
16951 (service cuirass-service-type
16952 (cuirass-configuration
16953 (specifications #~(list '#$spec)))))
16956 While information related to build jobs is located directly in the
16957 specifications, global settings for the @command{cuirass} process are
16958 accessible in other @code{cuirass-configuration} fields.
16960 @deftp {Data Type} cuirass-configuration
16961 Data type representing the configuration of Cuirass.
16964 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
16965 Location of the log file.
16967 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
16968 Location of the repository cache.
16970 @item @code{user} (default: @code{"cuirass"})
16971 Owner of the @code{cuirass} process.
16973 @item @code{group} (default: @code{"cuirass"})
16974 Owner's group of the @code{cuirass} process.
16976 @item @code{interval} (default: @code{60})
16977 Number of seconds between the poll of the repositories followed by the
16980 @item @code{database} (default: @code{"/var/run/cuirass/cuirass.db"})
16981 Location of sqlite database which contains the build results and previously
16982 added specifications.
16984 @item @code{port} (default: @code{8081})
16985 Port number used by the HTTP server.
16987 @item --listen=@var{host}
16988 Listen on the network interface for @var{host}. The default is to
16989 accept connections from localhost.
16991 @item @code{specifications} (default: @code{#~'()})
16992 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
16993 where a specification is an association list
16994 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
16995 keys are keywords (@code{#:keyword-example}) as shown in the example
16998 @item @code{use-substitutes?} (default: @code{#f})
16999 This allows using substitutes to avoid building every dependencies of a job
17002 @item @code{one-shot?} (default: @code{#f})
17003 Only evaluate specifications and build derivations once.
17005 @item @code{fallback?} (default: @code{#f})
17006 When substituting a pre-built binary fails, fall back to building
17009 @item @code{load-path} (default: @code{'()})
17010 This allows users to define their own packages and make them visible to
17011 cuirass as in @command{guix build} command.
17013 @item @code{cuirass} (default: @code{cuirass})
17014 The Cuirass package to use.
17018 @node Power management Services
17019 @subsubsection Power management Services
17021 @cindex power management with TLP
17022 The @code{(gnu services pm)} module provides a Guix service definition
17023 for the Linux power management tool TLP.
17025 TLP enables various powersaving modes in userspace and kernel.
17026 Contrary to @code{upower-service}, it is not a passive,
17027 monitoring tool, as it will apply custom settings each time a new power
17028 source is detected. More information can be found at
17029 @uref{http://linrunner.de/en/tlp/tlp.html, TLP home page}.
17031 @deffn {Scheme Variable} tlp-service-type
17032 The service type for the TLP tool. Its value should be a valid
17033 TLP configuration (see below). To use the default settings, simply
17036 (service tlp-service-type)
17040 By default TLP does not need much configuration but most TLP parameters
17041 can be tweaked using @code{tlp-configuration}.
17043 Each parameter definition is preceded by its type; for example,
17044 @samp{boolean foo} indicates that the @code{foo} parameter
17045 should be specified as a boolean. Types starting with
17046 @code{maybe-} denote parameters that won't show up in TLP config file
17047 when their value is @code{'disabled}.
17049 @c The following documentation was initially generated by
17050 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
17051 @c documentation is better, so we shouldn't hesitate to edit below as
17052 @c needed. However if the change you want to make to this documentation
17053 @c can be done in an automated way, it's probably easier to change
17054 @c (generate-documentation) than to make it below and have to deal with
17055 @c the churn as TLP updates.
17057 Available @code{tlp-configuration} fields are:
17059 @deftypevr {@code{tlp-configuration} parameter} package tlp
17064 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
17065 Set to true if you wish to enable TLP.
17067 Defaults to @samp{#t}.
17071 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
17072 Default mode when no power supply can be detected. Alternatives are AC
17075 Defaults to @samp{"AC"}.
17079 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
17080 Number of seconds Linux kernel has to wait after the disk goes idle,
17081 before syncing on AC.
17083 Defaults to @samp{0}.
17087 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
17088 Same as @code{disk-idle-ac} but on BAT mode.
17090 Defaults to @samp{2}.
17094 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
17095 Dirty pages flushing periodicity, expressed in seconds.
17097 Defaults to @samp{15}.
17101 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
17102 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
17104 Defaults to @samp{60}.
17108 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
17109 CPU frequency scaling governor on AC mode. With intel_pstate driver,
17110 alternatives are powersave and performance. With acpi-cpufreq driver,
17111 alternatives are ondemand, powersave, performance and conservative.
17113 Defaults to @samp{disabled}.
17117 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
17118 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
17120 Defaults to @samp{disabled}.
17124 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
17125 Set the min available frequency for the scaling governor on AC.
17127 Defaults to @samp{disabled}.
17131 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
17132 Set the max available frequency for the scaling governor on AC.
17134 Defaults to @samp{disabled}.
17138 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
17139 Set the min available frequency for the scaling governor on BAT.
17141 Defaults to @samp{disabled}.
17145 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
17146 Set the max available frequency for the scaling governor on BAT.
17148 Defaults to @samp{disabled}.
17152 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
17153 Limit the min P-state to control the power dissipation of the CPU, in AC
17154 mode. Values are stated as a percentage of the available performance.
17156 Defaults to @samp{disabled}.
17160 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
17161 Limit the max P-state to control the power dissipation of the CPU, in AC
17162 mode. Values are stated as a percentage of the available performance.
17164 Defaults to @samp{disabled}.
17168 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
17169 Same as @code{cpu-min-perf-on-ac} on BAT mode.
17171 Defaults to @samp{disabled}.
17175 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
17176 Same as @code{cpu-max-perf-on-ac} on BAT mode.
17178 Defaults to @samp{disabled}.
17182 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
17183 Enable CPU turbo boost feature on AC mode.
17185 Defaults to @samp{disabled}.
17189 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
17190 Same as @code{cpu-boost-on-ac?} on BAT mode.
17192 Defaults to @samp{disabled}.
17196 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
17197 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
17198 used under light load conditions.
17200 Defaults to @samp{#f}.
17204 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
17205 Same as @code{sched-powersave-on-ac?} but on BAT mode.
17207 Defaults to @samp{#t}.
17211 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
17212 Enable Linux kernel NMI watchdog.
17214 Defaults to @samp{#f}.
17218 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
17219 For Linux kernels with PHC patch applied, change CPU voltages. An
17220 example value would be @samp{"F:V F:V F:V F:V"}.
17222 Defaults to @samp{disabled}.
17226 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
17227 Set CPU performance versus energy saving policy on AC. Alternatives are
17228 performance, normal, powersave.
17230 Defaults to @samp{"performance"}.
17234 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
17235 Same as @code{energy-perf-policy-ac} but on BAT mode.
17237 Defaults to @samp{"powersave"}.
17241 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
17246 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
17247 Hard disk advanced power management level.
17251 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
17252 Same as @code{disk-apm-bat} but on BAT mode.
17256 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
17257 Hard disk spin down timeout. One value has to be specified for each
17258 declared hard disk.
17260 Defaults to @samp{disabled}.
17264 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
17265 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
17267 Defaults to @samp{disabled}.
17271 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
17272 Select IO scheduler for disk devices. One value has to be specified for
17273 each declared hard disk. Example alternatives are cfq, deadline and
17276 Defaults to @samp{disabled}.
17280 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
17281 SATA aggressive link power management (ALPM) level. Alternatives are
17282 min_power, medium_power, max_performance.
17284 Defaults to @samp{"max_performance"}.
17288 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
17289 Same as @code{sata-linkpwr-ac} but on BAT mode.
17291 Defaults to @samp{"min_power"}.
17295 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
17296 Exclude specified SATA host devices for link power management.
17298 Defaults to @samp{disabled}.
17302 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
17303 Enable Runtime Power Management for AHCI controller and disks on AC
17306 Defaults to @samp{disabled}.
17310 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
17311 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
17313 Defaults to @samp{disabled}.
17317 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
17318 Seconds of inactivity before disk is suspended.
17320 Defaults to @samp{15}.
17324 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
17325 PCI Express Active State Power Management level. Alternatives are
17326 default, performance, powersave.
17328 Defaults to @samp{"performance"}.
17332 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
17333 Same as @code{pcie-aspm-ac} but on BAT mode.
17335 Defaults to @samp{"powersave"}.
17339 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
17340 Radeon graphics clock speed level. Alternatives are low, mid, high,
17343 Defaults to @samp{"high"}.
17347 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
17348 Same as @code{radeon-power-ac} but on BAT mode.
17350 Defaults to @samp{"low"}.
17354 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
17355 Radeon dynamic power management method (DPM). Alternatives are battery,
17358 Defaults to @samp{"performance"}.
17362 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
17363 Same as @code{radeon-dpm-state-ac} but on BAT mode.
17365 Defaults to @samp{"battery"}.
17369 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
17370 Radeon DPM performance level. Alternatives are auto, low, high.
17372 Defaults to @samp{"auto"}.
17376 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
17377 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
17379 Defaults to @samp{"auto"}.
17383 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
17384 Wifi power saving mode.
17386 Defaults to @samp{#f}.
17390 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
17391 Same as @code{wifi-power-ac?} but on BAT mode.
17393 Defaults to @samp{#t}.
17397 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
17398 Disable wake on LAN.
17400 Defaults to @samp{#t}.
17404 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
17405 Timeout duration in seconds before activating audio power saving on
17406 Intel HDA and AC97 devices. A value of 0 disables power saving.
17408 Defaults to @samp{0}.
17412 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
17413 Same as @code{sound-powersave-ac} but on BAT mode.
17415 Defaults to @samp{1}.
17419 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
17420 Disable controller in powersaving mode on Intel HDA devices.
17422 Defaults to @samp{#t}.
17426 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
17427 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
17428 powered on again by releasing (and reinserting) the eject lever or by
17429 pressing the disc eject button on newer models.
17431 Defaults to @samp{#f}.
17435 @deftypevr {@code{tlp-configuration} parameter} string bay-device
17436 Name of the optical drive device to power off.
17438 Defaults to @samp{"sr0"}.
17442 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
17443 Runtime Power Management for PCI(e) bus devices. Alternatives are on
17446 Defaults to @samp{"on"}.
17450 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
17451 Same as @code{runtime-pm-ac} but on BAT mode.
17453 Defaults to @samp{"auto"}.
17457 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
17458 Runtime Power Management for all PCI(e) bus devices, except blacklisted
17461 Defaults to @samp{#t}.
17465 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
17466 Exclude specified PCI(e) device addresses from Runtime Power Management.
17468 Defaults to @samp{disabled}.
17472 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
17473 Exclude PCI(e) devices assigned to the specified drivers from Runtime
17478 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
17479 Enable USB autosuspend feature.
17481 Defaults to @samp{#t}.
17485 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
17486 Exclude specified devices from USB autosuspend.
17488 Defaults to @samp{disabled}.
17492 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
17493 Exclude WWAN devices from USB autosuspend.
17495 Defaults to @samp{#t}.
17499 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
17500 Include specified devices into USB autosuspend, even if they are already
17501 excluded by the driver or via @code{usb-blacklist-wwan?}.
17503 Defaults to @samp{disabled}.
17507 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
17508 Enable USB autosuspend before shutdown.
17510 Defaults to @samp{disabled}.
17514 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
17515 Restore radio device state (bluetooth, wifi, wwan) from previous
17516 shutdown on system startup.
17518 Defaults to @samp{#f}.
17523 The @code{(gnu services pm)} module provides an interface to
17524 thermald, a CPU frequency scaling service which helps prevent overheating.
17526 @defvr {Scheme Variable} thermald-service-type
17527 This is the service type for
17528 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
17529 Thermal Daemon, which is responsible for controlling the thermal state
17530 of processors and preventing overheating.
17533 @deftp {Data Type} thermald-configuration
17534 Data type representing the configuration of @code{thermald-service-type}.
17537 @item @code{ignore-cpuid-check?} (default: @code{#f})
17538 Ignore cpuid check for supported CPU models.
17540 @item @code{thermald} (default: @var{thermald})
17541 Package object of thermald.
17546 @node Audio Services
17547 @subsubsection Audio Services
17549 The @code{(gnu services audio)} module provides a service to start MPD
17550 (the Music Player Daemon).
17553 @subsubheading Music Player Daemon
17555 The Music Player Daemon (MPD) is a service that can play music while
17556 being controlled from the local machine or over the network by a variety
17559 The following example shows how one might run @code{mpd} as user
17560 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
17563 (service mpd-service-type
17569 @defvr {Scheme Variable} mpd-service-type
17570 The service type for @command{mpd}
17573 @deftp {Data Type} mpd-configuration
17574 Data type representing the configuration of @command{mpd}.
17577 @item @code{user} (default: @code{"mpd"})
17578 The user to run mpd as.
17580 @item @code{music-dir} (default: @code{"~/Music"})
17581 The directory to scan for music files.
17583 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
17584 The directory to store playlists.
17586 @item @code{port} (default: @code{"6600"})
17587 The port to run mpd on.
17589 @item @code{address} (default: @code{"any"})
17590 The address that mpd will bind to. To use a Unix domain socket,
17591 an absolute path can be specified here.
17596 @node Virtualization Services
17597 @subsubsection Virtualization services
17599 The @code{(gnu services virtualization)} module provides services for
17600 the libvirt and virtlog daemons, as well as other virtualization-related
17603 @subsubheading Libvirt daemon
17604 @code{libvirtd} is the server side daemon component of the libvirt
17605 virtualization management system. This daemon runs on host servers
17606 and performs required management tasks for virtualized guests.
17608 @deffn {Scheme Variable} libvirt-service-type
17609 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
17610 Its value must be a @code{libvirt-configuration}.
17613 (service libvirt-service-type
17614 (libvirt-configuration
17615 (unix-sock-group "libvirt")
17616 (tls-port "16555")))
17620 @c Auto-generated with (generate-libvirt-documentation)
17621 Available @code{libvirt-configuration} fields are:
17623 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
17628 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
17629 Flag listening for secure TLS connections on the public TCP/IP port.
17630 must set @code{listen} for this to have any effect.
17632 It is necessary to setup a CA and issue server certificates before using
17635 Defaults to @samp{#t}.
17639 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
17640 Listen for unencrypted TCP connections on the public TCP/IP port. must
17641 set @code{listen} for this to have any effect.
17643 Using the TCP socket requires SASL authentication by default. Only SASL
17644 mechanisms which support data encryption are allowed. This is
17645 DIGEST_MD5 and GSSAPI (Kerberos5)
17647 Defaults to @samp{#f}.
17651 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
17652 Port for accepting secure TLS connections This can be a port number, or
17655 Defaults to @samp{"16514"}.
17659 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
17660 Port for accepting insecure TCP connections This can be a port number,
17663 Defaults to @samp{"16509"}.
17667 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
17668 IP address or hostname used for client connections.
17670 Defaults to @samp{"0.0.0.0"}.
17674 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
17675 Flag toggling mDNS advertisement of the libvirt service.
17677 Alternatively can disable for all services on a host by stopping the
17680 Defaults to @samp{#f}.
17684 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
17685 Default mDNS advertisement name. This must be unique on the immediate
17688 Defaults to @samp{"Virtualization Host <hostname>"}.
17692 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
17693 UNIX domain socket group ownership. This can be used to allow a
17694 'trusted' set of users access to management capabilities without
17697 Defaults to @samp{"root"}.
17701 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
17702 UNIX socket permissions for the R/O socket. This is used for monitoring
17705 Defaults to @samp{"0777"}.
17709 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
17710 UNIX socket permissions for the R/W socket. Default allows only root.
17711 If PolicyKit is enabled on the socket, the default will change to allow
17712 everyone (eg, 0777)
17714 Defaults to @samp{"0770"}.
17718 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
17719 UNIX socket permissions for the admin socket. Default allows only owner
17720 (root), do not change it unless you are sure to whom you are exposing
17723 Defaults to @samp{"0777"}.
17727 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
17728 The directory in which sockets will be found/created.
17730 Defaults to @samp{"/var/run/libvirt"}.
17734 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
17735 Authentication scheme for UNIX read-only sockets. By default socket
17736 permissions allow anyone to connect
17738 Defaults to @samp{"polkit"}.
17742 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
17743 Authentication scheme for UNIX read-write sockets. By default socket
17744 permissions only allow root. If PolicyKit support was compiled into
17745 libvirt, the default will be to use 'polkit' auth.
17747 Defaults to @samp{"polkit"}.
17751 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
17752 Authentication scheme for TCP sockets. If you don't enable SASL, then
17753 all TCP traffic is cleartext. Don't do this outside of a dev/test
17756 Defaults to @samp{"sasl"}.
17760 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
17761 Authentication scheme for TLS sockets. TLS sockets already have
17762 encryption provided by the TLS layer, and limited authentication is done
17765 It is possible to make use of any SASL authentication mechanism as well,
17766 by using 'sasl' for this option
17768 Defaults to @samp{"none"}.
17772 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
17773 API access control scheme.
17775 By default an authenticated user is allowed access to all APIs. Access
17776 drivers can place restrictions on this.
17778 Defaults to @samp{()}.
17782 @deftypevr {@code{libvirt-configuration} parameter} string key-file
17783 Server key file path. If set to an empty string, then no private key is
17786 Defaults to @samp{""}.
17790 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
17791 Server key file path. If set to an empty string, then no certificate is
17794 Defaults to @samp{""}.
17798 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
17799 Server key file path. If set to an empty string, then no CA certificate
17802 Defaults to @samp{""}.
17806 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
17807 Certificate revocation list path. If set to an empty string, then no
17810 Defaults to @samp{""}.
17814 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
17815 Disable verification of our own server certificates.
17817 When libvirtd starts it performs some sanity checks against its own
17820 Defaults to @samp{#f}.
17824 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
17825 Disable verification of client certificates.
17827 Client certificate verification is the primary authentication mechanism.
17828 Any client which does not present a certificate signed by the CA will be
17831 Defaults to @samp{#f}.
17835 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
17836 Whitelist of allowed x509 Distinguished Name.
17838 Defaults to @samp{()}.
17842 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
17843 Whitelist of allowed SASL usernames. The format for username depends on
17844 the SASL authentication mechanism.
17846 Defaults to @samp{()}.
17850 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
17851 Override the compile time default TLS priority string. The default is
17852 usually "NORMAL" unless overridden at build time. Only set this is it
17853 is desired for libvirt to deviate from the global default settings.
17855 Defaults to @samp{"NORMAL"}.
17859 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
17860 Maximum number of concurrent client connections to allow over all
17863 Defaults to @samp{5000}.
17867 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
17868 Maximum length of queue of connections waiting to be accepted by the
17869 daemon. Note, that some protocols supporting retransmission may obey
17870 this so that a later reattempt at connection succeeds.
17872 Defaults to @samp{1000}.
17876 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
17877 Maximum length of queue of accepted but not yet authenticated clients.
17878 Set this to zero to turn this feature off
17880 Defaults to @samp{20}.
17884 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
17885 Number of workers to start up initially.
17887 Defaults to @samp{5}.
17891 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
17892 Maximum number of worker threads.
17894 If the number of active clients exceeds @code{min-workers}, then more
17895 threads are spawned, up to max_workers limit. Typically you'd want
17896 max_workers to equal maximum number of clients allowed.
17898 Defaults to @samp{20}.
17902 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
17903 Number of priority workers. If all workers from above pool are stuck,
17904 some calls marked as high priority (notably domainDestroy) can be
17905 executed in this pool.
17907 Defaults to @samp{5}.
17911 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
17912 Total global limit on concurrent RPC calls.
17914 Defaults to @samp{20}.
17918 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
17919 Limit on concurrent requests from a single client connection. To avoid
17920 one client monopolizing the server this should be a small fraction of
17921 the global max_requests and max_workers parameter.
17923 Defaults to @samp{5}.
17927 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
17928 Same as @code{min-workers} but for the admin interface.
17930 Defaults to @samp{1}.
17934 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
17935 Same as @code{max-workers} but for the admin interface.
17937 Defaults to @samp{5}.
17941 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
17942 Same as @code{max-clients} but for the admin interface.
17944 Defaults to @samp{5}.
17948 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
17949 Same as @code{max-queued-clients} but for the admin interface.
17951 Defaults to @samp{5}.
17955 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
17956 Same as @code{max-client-requests} but for the admin interface.
17958 Defaults to @samp{5}.
17962 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
17963 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
17965 Defaults to @samp{3}.
17969 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
17972 A filter allows to select a different logging level for a given category
17973 of logs The format for a filter is one of:
17984 where @code{name} is a string which is matched against the category
17985 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
17986 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
17987 be a substring of the full category name, in order to match multiple
17988 similar categories), the optional "+" prefix tells libvirt to log stack
17989 trace for each message matching name, and @code{x} is the minimal level
17990 where matching messages should be logged:
18007 Multiple filters can be defined in a single filters statement, they just
18008 need to be separated by spaces.
18010 Defaults to @samp{"3:remote 4:event"}.
18014 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
18017 An output is one of the places to save logging information The format
18018 for an output can be:
18022 output goes to stderr
18024 @item x:syslog:name
18025 use syslog for the output and use the given name as the ident
18027 @item x:file:file_path
18028 output to a file, with the given filepath
18031 output to journald logging system
18035 In all case the x prefix is the minimal level, acting as a filter
18052 Multiple outputs can be defined, they just need to be separated by
18055 Defaults to @samp{"3:stderr"}.
18059 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
18060 Allows usage of the auditing subsystem to be altered
18064 0: disable all auditing
18067 1: enable auditing, only if enabled on host
18070 2: enable auditing, and exit if disabled on host.
18074 Defaults to @samp{1}.
18078 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
18079 Send audit messages via libvirt logging infrastructure.
18081 Defaults to @samp{#f}.
18085 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
18086 Host UUID. UUID must not have all digits be the same.
18088 Defaults to @samp{""}.
18092 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
18093 Source to read host UUID.
18097 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
18100 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
18104 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
18107 Defaults to @samp{"smbios"}.
18111 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
18112 A keepalive message is sent to a client after @code{keepalive_interval}
18113 seconds of inactivity to check if the client is still responding. If
18114 set to -1, libvirtd will never send keepalive requests; however clients
18115 can still send them and the daemon will send responses.
18117 Defaults to @samp{5}.
18121 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
18122 Maximum number of keepalive messages that are allowed to be sent to the
18123 client without getting any response before the connection is considered
18126 In other words, the connection is automatically closed approximately
18127 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
18128 the last message received from the client. When @code{keepalive-count}
18129 is set to 0, connections will be automatically closed after
18130 @code{keepalive-interval} seconds of inactivity without sending any
18131 keepalive messages.
18133 Defaults to @samp{5}.
18137 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
18138 Same as above but for admin interface.
18140 Defaults to @samp{5}.
18144 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
18145 Same as above but for admin interface.
18147 Defaults to @samp{5}.
18151 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
18152 Timeout for Open vSwitch calls.
18154 The @code{ovs-vsctl} utility is used for the configuration and its
18155 timeout option is set by default to 5 seconds to avoid potential
18156 infinite waits blocking libvirt.
18158 Defaults to @samp{5}.
18162 @c %end of autogenerated docs
18164 @subsubheading Virtlog daemon
18165 The virtlogd service is a server side daemon component of libvirt that is
18166 used to manage logs from virtual machine consoles.
18168 This daemon is not used directly by libvirt client applications, rather it
18169 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
18170 standalone daemon, the main @code{libvirtd} daemon can be restarted without
18171 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
18172 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
18174 @deffn {Scheme Variable} virtlog-service-type
18175 This is the type of the virtlog daemon.
18176 Its value must be a @code{virtlog-configuration}.
18179 (service virtlog-service-type
18180 (virtlog-configuration
18181 (max-clients 1000)))
18185 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
18186 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
18188 Defaults to @samp{3}.
18192 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
18195 A filter allows to select a different logging level for a given category
18196 of logs The format for a filter is one of:
18207 where @code{name} is a string which is matched against the category
18208 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
18209 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
18210 be a substring of the full category name, in order to match multiple
18211 similar categories), the optional "+" prefix tells libvirt to log stack
18212 trace for each message matching name, and @code{x} is the minimal level
18213 where matching messages should be logged:
18230 Multiple filters can be defined in a single filters statement, they just
18231 need to be separated by spaces.
18233 Defaults to @samp{"3:remote 4:event"}.
18237 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
18240 An output is one of the places to save logging information The format
18241 for an output can be:
18245 output goes to stderr
18247 @item x:syslog:name
18248 use syslog for the output and use the given name as the ident
18250 @item x:file:file_path
18251 output to a file, with the given filepath
18254 output to journald logging system
18258 In all case the x prefix is the minimal level, acting as a filter
18275 Multiple outputs can be defined, they just need to be separated by
18278 Defaults to @samp{"3:stderr"}.
18282 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
18283 Maximum number of concurrent client connections to allow over all
18286 Defaults to @samp{1024}.
18290 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
18291 Maximum file size before rolling over.
18293 Defaults to @samp{2MB}
18297 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
18298 Maximum number of backup files to keep.
18300 Defaults to @samp{3}
18304 @subsubheading Transparent Emulation with QEMU
18307 @cindex @code{binfmt_misc}
18308 @code{qemu-binfmt-service-type} provides support for transparent
18309 emulation of program binaries built for different architectures---e.g.,
18310 it allows you to transparently execute an ARMv7 program on an x86_64
18311 machine. It achieves this by combining the @uref{https://www.qemu.org,
18312 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
18314 @defvr {Scheme Variable} qemu-binfmt-service-type
18315 This is the type of the QEMU/binfmt service for transparent emulation.
18316 Its value must be a @code{qemu-binfmt-configuration} object, which
18317 specifies the QEMU package to use as well as the architecture we want to
18321 (service qemu-binfmt-service-type
18322 (qemu-binfmt-configuration
18323 (platforms (lookup-qemu-platforms "arm" "aarch64" "ppc"))))
18326 In this example, we enable transparent emulation for the ARM and aarch64
18327 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
18328 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
18329 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
18332 @deftp {Data Type} qemu-binfmt-configuration
18333 This is the configuration for the @code{qemu-binfmt} service.
18336 @item @code{platforms} (default: @code{'()})
18337 The list of emulated QEMU platforms. Each item must be a @dfn{platform
18338 object} as returned by @code{lookup-qemu-platforms} (see below).
18340 @item @code{guix-support?} (default: @code{#f})
18341 When it is true, QEMU and all its dependencies are added to the build
18342 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
18343 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
18344 handlers to be used within the build environment, which in turn means
18345 that you can transparently build programs for another architecture.
18347 For example, let's suppose you're on an x86_64 machine and you have this
18351 (service qemu-binfmt-service-type
18352 (qemu-binfmt-configuration
18353 (platforms (lookup-qemu-platforms "arm"))
18354 (guix-support? #t)))
18360 guix build -s armhf-linux inkscape
18364 and it will build Inkscape for ARMv7 @emph{as if it were a native
18365 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
18366 if you'd like to test a package build for an architecture you don't have
18369 @item @code{qemu} (default: @code{qemu})
18370 The QEMU package to use.
18374 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
18375 Return the list of QEMU platform objects corresponding to
18376 @var{platforms}@dots{}. @var{platforms} must be a list of strings
18377 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
18378 @code{"mips64el"}, and so on.
18381 @deffn {Scheme Procedure} qemu-platform? @var{obj}
18382 Return true if @var{obj} is a platform object.
18385 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
18386 Return the name of @var{platform}---a string such as @code{"arm"}.
18389 @node Version Control Services
18390 @subsubsection Version Control Services
18392 The @code{(gnu services version-control)} module provides a service to
18393 allow remote access to local Git repositories. There are three options:
18394 the @code{git-daemon-service}, which provides access to repositories via
18395 the @code{git://} unsecured TCP-based protocol, extending the
18396 @code{nginx} web server to proxy some requests to
18397 @code{git-http-backend}, or providing a web interface with
18398 @code{cgit-service-type}.
18400 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
18402 Return a service that runs @command{git daemon}, a simple TCP server to
18403 expose repositories over the Git protocol for anonymous access.
18405 The optional @var{config} argument should be a
18406 @code{<git-daemon-configuration>} object, by default it allows read-only
18407 access to exported@footnote{By creating the magic file
18408 "git-daemon-export-ok" in the repository directory.} repositories under
18413 @deftp {Data Type} git-daemon-configuration
18414 Data type representing the configuration for @code{git-daemon-service}.
18417 @item @code{package} (default: @var{git})
18418 Package object of the Git distributed version control system.
18420 @item @code{export-all?} (default: @var{#f})
18421 Whether to allow access for all Git repositories, even if they do not
18422 have the @file{git-daemon-export-ok} file.
18424 @item @code{base-path} (default: @file{/srv/git})
18425 Whether to remap all the path requests as relative to the given path.
18426 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
18427 then if you later try to pull @code{git://example.com/hello.git}, git
18428 daemon will interpret the path as @code{/srv/git/hello.git}.
18430 @item @code{user-path} (default: @var{#f})
18431 Whether to allow @code{~user} notation to be used in requests. When
18432 specified with empty string, requests to @code{git://host/~alice/foo} is
18433 taken as a request to access @code{foo} repository in the home directory
18434 of user @code{alice}. If @var{(user-path "path")} is specified, the
18435 same request is taken as a request to access @code{path/foo} repository
18436 in the home directory of user @code{alice}.
18438 @item @code{listen} (default: @var{'()})
18439 Whether to listen on specific IP addresses or hostnames, defaults to
18442 @item @code{port} (default: @var{#f})
18443 Whether to listen on an alternative port, which defaults to 9418.
18445 @item @code{whitelist} (default: @var{'()})
18446 If not empty, only allow access to this list of directories.
18448 @item @code{extra-options} (default: @var{'()})
18449 Extra options will be passed to @code{git daemon}, please run
18450 @command{man git-daemon} for more information.
18455 The @code{git://} protocol lacks authentication. When you pull from a
18456 repository fetched via @code{git://}, you don't know that the data you
18457 receive was modified is really coming from the specified host, and you
18458 have your connection is subject to eavesdropping. It's better to use an
18459 authenticated and encrypted transport, such as @code{https}. Although Git allows you
18460 to serve repositories using unsophisticated file-based web servers,
18461 there is a faster protocol implemented by the @code{git-http-backend}
18462 program. This program is the back-end of a proper Git web service. It
18463 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
18464 on running the necessary @code{fcgiwrap} daemon.
18466 Guix has a separate configuration data type for serving Git repositories
18469 @deftp {Data Type} git-http-configuration
18470 Data type representing the configuration for @code{git-http-service}.
18473 @item @code{package} (default: @var{git})
18474 Package object of the Git distributed version control system.
18476 @item @code{git-root} (default: @file{/srv/git})
18477 Directory containing the Git repositories to expose to the world.
18479 @item @code{export-all?} (default: @var{#f})
18480 Whether to expose access for all Git repositories in @var{git-root},
18481 even if they do not have the @file{git-daemon-export-ok} file.
18483 @item @code{uri-path} (default: @file{/git/})
18484 Path prefix for Git access. With the default @code{/git/} prefix, this
18485 will map @code{http://@var{server}/git/@var{repo}.git} to
18486 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
18487 with this prefix are not passed on to this Git instance.
18489 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
18490 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
18495 There is no @code{git-http-service-type}, currently; instead you can
18496 create an @code{nginx-location-configuration} from a
18497 @code{git-http-configuration} and then add that location to a web
18500 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
18501 [config=(git-http-configuration)]
18502 Compute an @code{nginx-location-configuration} that corresponds to the
18503 given Git http configuration. An example nginx service definition to
18504 serve the default @file{/srv/git} over HTTPS might be:
18507 (service nginx-service-type
18508 (nginx-configuration
18511 (nginx-server-configuration
18512 (listen '("443 ssl"))
18513 (server-name "git.my-host.org")
18515 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
18516 (ssl-certificate-key
18517 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
18520 (git-http-nginx-location-configuration
18521 (git-http-configuration (uri-path "/"))))))))))
18524 This example assumes that you are using Let's Encrypt to get your TLS
18525 certificate. @xref{Certificate Services}. The default @code{certbot}
18526 service will redirect all HTTP traffic on @code{git.my-host.org} to
18527 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
18528 system services. @xref{Web Services}.
18531 @subsubheading Cgit Service
18533 @cindex Cgit service
18534 @cindex Git, web interface
18535 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
18536 repositories written in C.
18538 The following example will configure the service with default values.
18539 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
18542 (service cgit-service-type)
18545 The @code{file-object} type designates either a file-like object
18546 (@pxref{G-Expressions, file-like objects}) or a string.
18548 @c %start of fragment
18550 Available @code{cgit-configuration} fields are:
18552 @deftypevr {@code{cgit-configuration} parameter} package package
18557 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
18558 NGINX configuration.
18562 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
18563 Specifies a command which will be invoked to format the content of about
18564 pages (both top-level and for each repository).
18566 Defaults to @samp{""}.
18570 @deftypevr {@code{cgit-configuration} parameter} string agefile
18571 Specifies a path, relative to each repository path, which can be used to
18572 specify the date and time of the youngest commit in the repository.
18574 Defaults to @samp{""}.
18578 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
18579 Specifies a command that will be invoked for authenticating repository
18582 Defaults to @samp{""}.
18586 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
18587 Flag which, when set to @samp{age}, enables date ordering in the branch
18588 ref list, and when set @samp{name} enables ordering by branch name.
18590 Defaults to @samp{"name"}.
18594 @deftypevr {@code{cgit-configuration} parameter} string cache-root
18595 Path used to store the cgit cache entries.
18597 Defaults to @samp{"/var/cache/cgit"}.
18601 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
18602 Number which specifies the time-to-live, in minutes, for the cached
18603 version of repository pages accessed with a fixed SHA1.
18605 Defaults to @samp{-1}.
18609 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
18610 Number which specifies the time-to-live, in minutes, for the cached
18611 version of repository pages accessed without a fixed SHA1.
18613 Defaults to @samp{5}.
18617 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
18618 Number which specifies the time-to-live, in minutes, for the cached
18619 version of the repository summary page.
18621 Defaults to @samp{5}.
18625 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
18626 Number which specifies the time-to-live, in minutes, for the cached
18627 version of the repository index page.
18629 Defaults to @samp{5}.
18633 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
18634 Number which specifies the time-to-live, in minutes, for the result of
18635 scanning a path for Git repositories.
18637 Defaults to @samp{15}.
18641 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
18642 Number which specifies the time-to-live, in minutes, for the cached
18643 version of the repository about page.
18645 Defaults to @samp{15}.
18649 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
18650 Number which specifies the time-to-live, in minutes, for the cached
18651 version of snapshots.
18653 Defaults to @samp{5}.
18657 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
18658 The maximum number of entries in the cgit cache. When set to @samp{0},
18659 caching is disabled.
18661 Defaults to @samp{0}.
18665 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
18666 Sort items in the repo list case sensitively.
18668 Defaults to @samp{#t}.
18672 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
18673 List of common prefixes which, when combined with a repository URL,
18674 generates valid clone URLs for the repository.
18676 Defaults to @samp{()}.
18680 @deftypevr {@code{cgit-configuration} parameter} list clone-url
18681 List of @code{clone-url} templates.
18683 Defaults to @samp{()}.
18687 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
18688 Command which will be invoked to format commit messages.
18690 Defaults to @samp{""}.
18694 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
18695 Flag which, when set to @samp{date}, enables strict date ordering in the
18696 commit log, and when set to @samp{topo} enables strict topological
18699 Defaults to @samp{"git log"}.
18703 @deftypevr {@code{cgit-configuration} parameter} file-object css
18704 URL which specifies the css document to include in all cgit pages.
18706 Defaults to @samp{"/share/cgit/cgit.css"}.
18710 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
18711 Specifies a command which will be invoked to format names and email
18712 address of committers, authors, and taggers, as represented in various
18713 places throughout the cgit interface.
18715 Defaults to @samp{""}.
18719 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
18720 Flag which, when set to @samp{#t}, will make cgit generate a HTML
18721 fragment suitable for embedding in other HTML pages.
18723 Defaults to @samp{#f}.
18727 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
18728 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
18729 commit history graph to the left of the commit messages in the
18730 repository log page.
18732 Defaults to @samp{#f}.
18736 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
18737 Flag which, when set to @samp{#t}, allows all filter settings to be
18738 overridden in repository-specific cgitrc files.
18740 Defaults to @samp{#f}.
18744 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
18745 Flag which, when set to @samp{#t}, allows users to follow a file in the
18748 Defaults to @samp{#f}.
18752 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
18753 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
18756 Defaults to @samp{#t}.
18760 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
18761 Flag which, when set to @samp{#t}, will make cgit generate extra links
18762 "summary", "commit", "tree" for each repo in the repository index.
18764 Defaults to @samp{#f}.
18768 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
18769 Flag which, when set to @samp{#t}, will make cgit display the owner of
18770 each repo in the repository index.
18772 Defaults to @samp{#t}.
18776 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
18777 Flag which, when set to @samp{#t}, will make cgit print the number of
18778 modified files for each commit on the repository log page.
18780 Defaults to @samp{#f}.
18784 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
18785 Flag which, when set to @samp{#t}, will make cgit print the number of
18786 added and removed lines for each commit on the repository log page.
18788 Defaults to @samp{#f}.
18792 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
18793 Flag which, when set to @code{#t}, will make cgit display remote
18794 branches in the summary and refs views.
18796 Defaults to @samp{#f}.
18800 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
18801 Flag which, when set to @code{1}, will make cgit use the subject of the
18802 parent commit as link text when generating links to parent commits in
18805 Defaults to @samp{#f}.
18809 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
18810 Flag which, when set to @samp{#t}, will make cgit use the subject of the
18811 parent commit as link text when generating links to parent commits in
18814 Defaults to @samp{#f}.
18818 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
18819 Flag which, when set to @samp{#t}, will make cgit generate linenumber
18820 links for plaintext blobs printed in the tree view.
18822 Defaults to @samp{#t}.
18826 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
18827 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
18828 set any repo specific settings.
18830 Defaults to @samp{#f}.
18834 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
18835 URL used as link to a shortcut icon for cgit.
18837 Defaults to @samp{"/favicon.ico"}.
18841 @deftypevr {@code{cgit-configuration} parameter} string footer
18842 The content of the file specified with this option will be included
18843 verbatim at the bottom of all pages (i.e. it replaces the standard
18844 "generated by..." message).
18846 Defaults to @samp{""}.
18850 @deftypevr {@code{cgit-configuration} parameter} string head-include
18851 The content of the file specified with this option will be included
18852 verbatim in the HTML HEAD section on all pages.
18854 Defaults to @samp{""}.
18858 @deftypevr {@code{cgit-configuration} parameter} string header
18859 The content of the file specified with this option will be included
18860 verbatim at the top of all pages.
18862 Defaults to @samp{""}.
18866 @deftypevr {@code{cgit-configuration} parameter} file-object include
18867 Name of a configfile to include before the rest of the current config-
18870 Defaults to @samp{""}.
18874 @deftypevr {@code{cgit-configuration} parameter} string index-header
18875 The content of the file specified with this option will be included
18876 verbatim above the repository index.
18878 Defaults to @samp{""}.
18882 @deftypevr {@code{cgit-configuration} parameter} string index-info
18883 The content of the file specified with this option will be included
18884 verbatim below the heading on the repository index page.
18886 Defaults to @samp{""}.
18890 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
18891 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
18892 in the servers timezone.
18894 Defaults to @samp{#f}.
18898 @deftypevr {@code{cgit-configuration} parameter} file-object logo
18899 URL which specifies the source of an image which will be used as a logo
18902 Defaults to @samp{"/share/cgit/cgit.png"}.
18906 @deftypevr {@code{cgit-configuration} parameter} string logo-link
18907 URL loaded when clicking on the cgit logo image.
18909 Defaults to @samp{""}.
18913 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
18914 Command which will be invoked to format the Owner column of the main
18917 Defaults to @samp{""}.
18921 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
18922 Number of items to display in atom feeds view.
18924 Defaults to @samp{10}.
18928 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
18929 Number of entries to list per page in "log" view.
18931 Defaults to @samp{50}.
18935 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
18936 Number of commit message characters to display in "log" view.
18938 Defaults to @samp{80}.
18942 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
18943 Specifies the number of entries to list per page on the repository index
18946 Defaults to @samp{50}.
18950 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
18951 Specifies the maximum number of repo description characters to display
18952 on the repository index page.
18954 Defaults to @samp{80}.
18958 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
18959 Specifies the maximum size of a blob to display HTML for in KBytes.
18961 Defaults to @samp{0}.
18965 @deftypevr {@code{cgit-configuration} parameter} string max-stats
18966 Maximum statistics period. Valid values are @samp{week},@samp{month},
18967 @samp{quarter} and @samp{year}.
18969 Defaults to @samp{""}.
18973 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
18974 Mimetype for the specified filename extension.
18976 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
18977 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
18978 "image/png") (svg "image/svg+xml"))}.
18982 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
18983 Specifies the file to use for automatic mimetype lookup.
18985 Defaults to @samp{""}.
18989 @deftypevr {@code{cgit-configuration} parameter} string module-link
18990 Text which will be used as the formatstring for a hyperlink when a
18991 submodule is printed in a directory listing.
18993 Defaults to @samp{""}.
18997 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
18998 If set to the value @samp{#t} caching will be disabled.
19000 Defaults to @samp{#f}.
19004 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
19005 If set to @samp{#t} showing full author email addresses will be
19008 Defaults to @samp{#f}.
19012 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
19013 Flag which, when set to @samp{#t}, will make cgit omit the standard
19014 header on all pages.
19016 Defaults to @samp{#f}.
19020 @deftypevr {@code{cgit-configuration} parameter} list project-list
19021 A list of subdirectories inside of @code{repository-directory}, relative
19022 to it, that should loaded as Git repositories. An empty list means that
19023 all subdirectories will be loaded.
19025 Defaults to @samp{()}.
19029 @deftypevr {@code{cgit-configuration} parameter} file-object readme
19030 Text which will be used as default value for @code{cgit-repo-readme}.
19032 Defaults to @samp{""}.
19036 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
19037 If set to @code{#t} and @code{repository-directory} is enabled, if any
19038 repositories are found with a suffix of @code{.git}, this suffix will be
19039 removed for the URL and name.
19041 Defaults to @samp{#f}.
19045 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
19046 Maximum number of files to consider when detecting renames.
19048 Defaults to @samp{-1}.
19052 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
19053 The way in which repositories in each section are sorted.
19055 Defaults to @samp{""}.
19059 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
19060 Text used as content for the @code{robots} meta-tag.
19062 Defaults to @samp{("noindex" "nofollow")}.
19066 @deftypevr {@code{cgit-configuration} parameter} string root-desc
19067 Text printed below the heading on the repository index page.
19069 Defaults to @samp{"a fast webinterface for the git dscm"}.
19073 @deftypevr {@code{cgit-configuration} parameter} string root-readme
19074 The content of the file specified with this option will be included
19075 verbatim below thef "about" link on the repository index page.
19077 Defaults to @samp{""}.
19081 @deftypevr {@code{cgit-configuration} parameter} string root-title
19082 Text printed as heading on the repository index page.
19084 Defaults to @samp{""}.
19088 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
19089 If set to @samp{#t} and repository-directory is enabled,
19090 repository-directory will recurse into directories whose name starts
19091 with a period. Otherwise, repository-directory will stay away from such
19092 directories, considered as "hidden". Note that this does not apply to
19093 the ".git" directory in non-bare repos.
19095 Defaults to @samp{#f}.
19099 @deftypevr {@code{cgit-configuration} parameter} list snapshots
19100 Text which specifies the default set of snapshot formats that cgit
19101 generates links for.
19103 Defaults to @samp{()}.
19107 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
19108 Name of the directory to scan for repositories (represents
19111 Defaults to @samp{"/srv/git"}.
19115 @deftypevr {@code{cgit-configuration} parameter} string section
19116 The name of the current repository section - all repositories defined
19117 after this option will inherit the current section name.
19119 Defaults to @samp{""}.
19123 @deftypevr {@code{cgit-configuration} parameter} string section-sort
19124 Flag which, when set to @samp{1}, will sort the sections on the
19125 repository listing by name.
19127 Defaults to @samp{""}.
19131 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
19132 A number which, if defined prior to repository-directory, specifies how
19133 many path elements from each repo path to use as a default section name.
19135 Defaults to @samp{0}.
19139 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
19140 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
19143 Defaults to @samp{#f}.
19147 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
19148 Specifies a command which will be invoked to format plaintext blobs in
19151 Defaults to @samp{""}.
19155 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
19156 Specifies the number of branches to display in the repository "summary"
19159 Defaults to @samp{10}.
19163 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
19164 Specifies the number of log entries to display in the repository
19167 Defaults to @samp{10}.
19171 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
19172 Specifies the number of tags to display in the repository "summary"
19175 Defaults to @samp{10}.
19179 @deftypevr {@code{cgit-configuration} parameter} string strict-export
19180 Filename which, if specified, needs to be present within the repository
19181 for cgit to allow access to that repository.
19183 Defaults to @samp{""}.
19187 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
19188 URL which, if specified, will be used as root for all cgit links.
19190 Defaults to @samp{"/"}.
19194 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
19195 A list of @dfn{cgit-repo} records to use with config.
19197 Defaults to @samp{()}.
19199 Available @code{repository-cgit-configuration} fields are:
19201 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
19202 A mask of snapshot formats for this repo that cgit generates links for,
19203 restricted by the global @code{snapshots} setting.
19205 Defaults to @samp{()}.
19209 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
19210 Override the default @code{source-filter}.
19212 Defaults to @samp{""}.
19216 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
19217 The relative URL used to access the repository.
19219 Defaults to @samp{""}.
19223 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
19224 Override the default @code{about-filter}.
19226 Defaults to @samp{""}.
19230 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
19231 Flag which, when set to @samp{age}, enables date ordering in the branch
19232 ref list, and when set to @samp{name} enables ordering by branch name.
19234 Defaults to @samp{""}.
19238 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
19239 A list of URLs which can be used to clone repo.
19241 Defaults to @samp{()}.
19245 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
19246 Override the default @code{commit-filter}.
19248 Defaults to @samp{""}.
19252 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
19253 Flag which, when set to @samp{date}, enables strict date ordering in the
19254 commit log, and when set to @samp{topo} enables strict topological
19257 Defaults to @samp{""}.
19261 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
19262 The name of the default branch for this repository. If no such branch
19263 exists in the repository, the first branch name (when sorted) is used as
19264 default instead. By default branch pointed to by HEAD, or "master" if
19265 there is no suitable HEAD.
19267 Defaults to @samp{""}.
19271 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
19272 The value to show as repository description.
19274 Defaults to @samp{""}.
19278 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
19279 The value to show as repository homepage.
19281 Defaults to @samp{""}.
19285 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
19286 Override the default @code{email-filter}.
19288 Defaults to @samp{""}.
19292 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-commit-graph?
19293 A flag which can be used to disable the global setting
19294 @code{enable-commit-graph?}.
19296 Defaults to @samp{#f}.
19300 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-log-filecount?
19301 A flag which can be used to disable the global setting
19302 @code{enable-log-filecount?}.
19304 Defaults to @samp{#f}.
19308 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-log-linecount?
19309 A flag which can be used to disable the global setting
19310 @code{enable-log-linecount?}.
19312 Defaults to @samp{#f}.
19316 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-remote-branches?
19317 Flag which, when set to @code{#t}, will make cgit display remote
19318 branches in the summary and refs views.
19320 Defaults to @samp{#f}.
19324 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-subject-links?
19325 A flag which can be used to override the global setting
19326 @code{enable-subject-links?}.
19328 Defaults to @samp{#f}.
19332 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean enable-html-serving?
19333 A flag which can be used to override the global setting
19334 @code{enable-html-serving?}.
19336 Defaults to @samp{#f}.
19340 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
19341 Flag which, when set to @code{#t}, hides the repository from the
19344 Defaults to @samp{#f}.
19348 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
19349 Flag which, when set to @samp{#t}, ignores the repository.
19351 Defaults to @samp{#f}.
19355 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
19356 URL which specifies the source of an image which will be used as a logo
19357 on this repo’s pages.
19359 Defaults to @samp{""}.
19363 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
19364 URL loaded when clicking on the cgit logo image.
19366 Defaults to @samp{""}.
19370 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
19371 Override the default @code{owner-filter}.
19373 Defaults to @samp{""}.
19377 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
19378 Text which will be used as the formatstring for a hyperlink when a
19379 submodule is printed in a directory listing. The arguments for the
19380 formatstring are the path and SHA1 of the submodule commit.
19382 Defaults to @samp{""}.
19386 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
19387 Text which will be used as the formatstring for a hyperlink when a
19388 submodule with the specified subdirectory path is printed in a directory
19391 Defaults to @samp{()}.
19395 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
19396 Override the default maximum statistics period.
19398 Defaults to @samp{""}.
19402 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
19403 The value to show as repository name.
19405 Defaults to @samp{""}.
19409 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
19410 A value used to identify the owner of the repository.
19412 Defaults to @samp{""}.
19416 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
19417 An absolute path to the repository directory.
19419 Defaults to @samp{""}.
19423 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
19424 A path (relative to repo) which specifies a file to include verbatim as
19425 the "About" page for this repo.
19427 Defaults to @samp{""}.
19431 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
19432 The name of the current repository section - all repositories defined
19433 after this option will inherit the current section name.
19435 Defaults to @samp{""}.
19439 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
19440 Extra options will be appended to cgitrc file.
19442 Defaults to @samp{()}.
19448 @deftypevr {@code{cgit-configuration} parameter} list extra-options
19449 Extra options will be appended to cgitrc file.
19451 Defaults to @samp{()}.
19456 @c %end of fragment
19458 However, it could be that you just want to get a @code{cgitrc} up and
19459 running. In that case, you can pass an @code{opaque-cgit-configuration}
19460 as a record to @code{cgit-service-type}. As its name indicates, an
19461 opaque configuration does not have easy reflective capabilities.
19463 Available @code{opaque-cgit-configuration} fields are:
19465 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
19469 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
19470 The contents of the @code{cgitrc}, as a string.
19473 For example, if your @code{cgitrc} is just the empty string, you
19474 could instantiate a cgit service like this:
19477 (service cgit-service-type
19478 (opaque-cgit-configuration
19483 @node Game Services
19484 @subsubsection Game Services
19486 @subsubheading The Battle for Wesnoth Service
19488 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
19489 based tactical strategy game, with several single player campaigns, and
19490 multiplayer games (both networked and local).
19492 @defvar {Scheme Variable} wesnothd-service-type
19493 Service type for the wesnothd service. Its value must be a
19494 @code{wesnothd-configuration} object. To run wesnothd in the default
19495 configuration, instantiate it as:
19498 (service wesnothd-service-type)
19502 @deftp {Data Type} wesnothd-configuration
19503 Data type representing the configuration of @command{wesnothd}.
19506 @item @code{package} (default: @code{wesnoth-server})
19507 The wesnoth server package to use.
19509 @item @code{port} (default: @code{15000})
19510 The port to bind the server to.
19514 @node Miscellaneous Services
19515 @subsubsection Miscellaneous Services
19518 @subsubheading System Control Service
19520 The @code{(gnu services sysctl)} provides a service to configure kernel
19521 parameters at boot.
19523 @defvr {Scheme Variable} sysctl-service-type
19524 The service type for @command{sysctl}, which modifies kernel parameters
19525 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
19529 (service sysctl-service-type
19530 (sysctl-configuration
19531 (settings '(("net.ipv4.ip_forward" . "1")))))
19535 @deftp {Data Type} sysctl-configuration
19536 The data type representing the configuration of @command{sysctl}.
19539 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
19540 The @command{sysctl} executable to use.
19542 @item @code{settings} (default: @code{'()})
19543 An association list specifies kernel parameters and their values.
19548 @subsubheading Lirc Service
19550 The @code{(gnu services lirc)} module provides the following service.
19552 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
19553 [#:device #f] [#:driver #f] [#:config-file #f] @
19554 [#:extra-options '()]
19555 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
19556 decodes infrared signals from remote controls.
19558 Optionally, @var{device}, @var{driver} and @var{config-file}
19559 (configuration file name) may be specified. See @command{lircd} manual
19562 Finally, @var{extra-options} is a list of additional command-line options
19563 passed to @command{lircd}.
19567 @subsubheading Spice Service
19569 The @code{(gnu services spice)} module provides the following service.
19571 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
19572 Returns a service that runs @url{http://www.spice-space.org,VDAGENT}, a daemon
19573 that enables sharing the clipboard with a vm and setting the guest display
19574 resolution when the graphical console window resizes.
19577 @subsubsection Dictionary Services
19579 The @code{(gnu services dict)} module provides the following service:
19581 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
19582 Return a service that runs the @command{dicod} daemon, an implementation
19583 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
19585 The optional @var{config} argument specifies the configuration for
19586 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
19587 default it serves the GNU Collaborative International Dictonary of English.
19589 You can add @command{open localhost} to your @file{~/.dico} file to make
19590 @code{localhost} the default server for @command{dico} client
19591 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
19594 @deftp {Data Type} dicod-configuration
19595 Data type representing the configuration of dicod.
19598 @item @code{dico} (default: @var{dico})
19599 Package object of the GNU Dico dictionary server.
19601 @item @code{interfaces} (default: @var{'("localhost")})
19602 This is the list of IP addresses and ports and possibly socket file
19603 names to listen to (@pxref{Server Settings, @code{listen} directive,,
19604 dico, GNU Dico Manual}).
19606 @item @code{handlers} (default: @var{'()})
19607 List of @code{<dicod-handler>} objects denoting handlers (module instances).
19609 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
19610 List of @code{<dicod-database>} objects denoting dictionaries to be served.
19614 @deftp {Data Type} dicod-handler
19615 Data type representing a dictionary handler (module instance).
19619 Name of the handler (module instance).
19621 @item @code{module} (default: @var{#f})
19622 Name of the dicod module of the handler (instance). If it is @code{#f},
19623 the module has the same name as the handler.
19624 (@pxref{Modules,,, dico, GNU Dico Manual}).
19626 @item @code{options}
19627 List of strings or gexps representing the arguments for the module handler
19631 @deftp {Data Type} dicod-database
19632 Data type representing a dictionary database.
19636 Name of the database, will be used in DICT commands.
19638 @item @code{handler}
19639 Name of the dicod handler (module instance) used by this database
19640 (@pxref{Handlers,,, dico, GNU Dico Manual}).
19642 @item @code{complex?} (default: @var{#f})
19643 Whether the database configuration complex. The complex configuration
19644 will need a corresponding @code{<dicod-handler>} object, otherwise not.
19646 @item @code{options}
19647 List of strings or gexps representing the arguments for the database
19648 (@pxref{Databases,,, dico, GNU Dico Manual}).
19652 @defvr {Scheme Variable} %dicod-database:gcide
19653 A @code{<dicod-database>} object serving the GNU Collaborative International
19654 Dictionary of English using the @code{gcide} package.
19657 The following is an example @code{dicod-service} configuration.
19660 (dicod-service #:config
19661 (dicod-configuration
19662 (handlers (list (dicod-handler
19666 (list #~(string-append "dbdir=" #$wordnet))))))
19667 (databases (list (dicod-database
19670 (handler "wordnet")
19671 (options '("database=wn")))
19672 %dicod-database:gcide))))
19675 @node Setuid Programs
19676 @subsection Setuid Programs
19678 @cindex setuid programs
19679 Some programs need to run with ``root'' privileges, even when they are
19680 launched by unprivileged users. A notorious example is the
19681 @command{passwd} program, which users can run to change their
19682 password, and which needs to access the @file{/etc/passwd} and
19683 @file{/etc/shadow} files---something normally restricted to root, for
19684 obvious security reasons. To address that, these executables are
19685 @dfn{setuid-root}, meaning that they always run with root privileges
19686 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
19687 for more info about the setuid mechanism.)
19689 The store itself @emph{cannot} contain setuid programs: that would be a
19690 security issue since any user on the system can write derivations that
19691 populate the store (@pxref{The Store}). Thus, a different mechanism is
19692 used: instead of changing the setuid bit directly on files that are in
19693 the store, we let the system administrator @emph{declare} which programs
19694 should be setuid root.
19696 The @code{setuid-programs} field of an @code{operating-system}
19697 declaration contains a list of G-expressions denoting the names of
19698 programs to be setuid-root (@pxref{Using the Configuration System}).
19699 For instance, the @command{passwd} program, which is part of the Shadow
19700 package, can be designated by this G-expression (@pxref{G-Expressions}):
19703 #~(string-append #$shadow "/bin/passwd")
19706 A default set of setuid programs is defined by the
19707 @code{%setuid-programs} variable of the @code{(gnu system)} module.
19709 @defvr {Scheme Variable} %setuid-programs
19710 A list of G-expressions denoting common programs that are setuid-root.
19712 The list includes commands such as @command{passwd}, @command{ping},
19713 @command{su}, and @command{sudo}.
19716 Under the hood, the actual setuid programs are created in the
19717 @file{/run/setuid-programs} directory at system activation time. The
19718 files in this directory refer to the ``real'' binaries, which are in the
19721 @node X.509 Certificates
19722 @subsection X.509 Certificates
19724 @cindex HTTPS, certificates
19725 @cindex X.509 certificates
19727 Web servers available over HTTPS (that is, HTTP over the transport-layer
19728 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
19729 that the client can then use to @emph{authenticate} the server. To do
19730 that, clients verify that the server's certificate is signed by a
19731 so-called @dfn{certificate authority} (CA). But to verify the CA's
19732 signature, clients must have first acquired the CA's certificate.
19734 Web browsers such as GNU@tie{}IceCat include their own set of CA
19735 certificates, such that they are able to verify CA signatures
19738 However, most other programs that can talk HTTPS---@command{wget},
19739 @command{git}, @command{w3m}, etc.---need to be told where CA
19740 certificates can be found.
19742 @cindex @code{nss-certs}
19743 In GuixSD, this is done by adding a package that provides certificates
19744 to the @code{packages} field of the @code{operating-system} declaration
19745 (@pxref{operating-system Reference}). GuixSD includes one such package,
19746 @code{nss-certs}, which is a set of CA certificates provided as part of
19747 Mozilla's Network Security Services.
19749 Note that it is @emph{not} part of @var{%base-packages}, so you need to
19750 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
19751 most applications and libraries look for certificates by default, points
19752 to the certificates installed globally.
19754 Unprivileged users, including users of Guix on a foreign distro,
19755 can also install their own certificate package in
19756 their profile. A number of environment variables need to be defined so
19757 that applications and libraries know where to find them. Namely, the
19758 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
19759 variables. Some applications add their own environment variables; for
19760 instance, the Git version control system honors the certificate bundle
19761 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
19762 would typically run something like:
19765 $ guix package -i nss-certs
19766 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
19767 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
19768 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
19771 As another example, R requires the @code{CURL_CA_BUNDLE} environment
19772 variable to point to a certificate bundle, so you would have to run
19773 something like this:
19776 $ guix package -i nss-certs
19777 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
19780 For other applications you may want to look up the required environment
19781 variable in the relevant documentation.
19784 @node Name Service Switch
19785 @subsection Name Service Switch
19787 @cindex name service switch
19789 The @code{(gnu system nss)} module provides bindings to the
19790 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
19791 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
19792 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
19793 extended with new ``name'' lookup methods for system databases, which
19794 includes host names, service names, user accounts, and more (@pxref{Name
19795 Service Switch, System Databases and Name Service Switch,, libc, The GNU
19796 C Library Reference Manual}).
19798 The NSS configuration specifies, for each system database, which lookup
19799 method is to be used, and how the various methods are chained
19800 together---for instance, under which circumstances NSS should try the
19801 next method in the list. The NSS configuration is given in the
19802 @code{name-service-switch} field of @code{operating-system} declarations
19803 (@pxref{operating-system Reference, @code{name-service-switch}}).
19806 @cindex .local, host name lookup
19807 As an example, the declaration below configures the NSS to use the
19808 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
19809 back-end}, which supports host name lookups over multicast DNS (mDNS)
19810 for host names ending in @code{.local}:
19813 (name-service-switch
19814 (hosts (list %files ;first, check /etc/hosts
19816 ;; If the above did not succeed, try
19817 ;; with 'mdns_minimal'.
19819 (name "mdns_minimal")
19821 ;; 'mdns_minimal' is authoritative for
19822 ;; '.local'. When it returns "not found",
19823 ;; no need to try the next methods.
19824 (reaction (lookup-specification
19825 (not-found => return))))
19827 ;; Then fall back to DNS.
19831 ;; Finally, try with the "full" 'mdns'.
19836 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
19837 contains this configuration, so you will not have to type it if all you
19838 want is to have @code{.local} host lookup working.
19840 Note that, in this case, in addition to setting the
19841 @code{name-service-switch} of the @code{operating-system} declaration,
19842 you also need to use @code{avahi-service} (@pxref{Networking Services,
19843 @code{avahi-service}}), or @var{%desktop-services}, which includes it
19844 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
19845 to the name service cache daemon (@pxref{Base Services,
19846 @code{nscd-service}}).
19848 For convenience, the following variables provide typical NSS
19851 @defvr {Scheme Variable} %default-nss
19852 This is the default name service switch configuration, a
19853 @code{name-service-switch} object.
19856 @defvr {Scheme Variable} %mdns-host-lookup-nss
19857 This is the name service switch configuration with support for host name
19858 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
19861 The reference for name service switch configuration is given below. It
19862 is a direct mapping of the configuration file format of the C library , so
19863 please refer to the C library manual for more information (@pxref{NSS
19864 Configuration File,,, libc, The GNU C Library Reference Manual}).
19865 Compared to the configuration file format of libc NSS, it has the advantage
19866 not only of adding this warm parenthetic feel that we like, but also
19867 static checks: you will know about syntax errors and typos as soon as you
19868 run @command{guix system}.
19870 @deftp {Data Type} name-service-switch
19872 This is the data type representation the configuration of libc's name
19873 service switch (NSS). Each field below represents one of the supported
19890 The system databases handled by the NSS. Each of these fields must be a
19891 list of @code{<name-service>} objects (see below).
19895 @deftp {Data Type} name-service
19897 This is the data type representing an actual name service and the
19898 associated lookup action.
19902 A string denoting the name service (@pxref{Services in the NSS
19903 configuration,,, libc, The GNU C Library Reference Manual}).
19905 Note that name services listed here must be visible to nscd. This is
19906 achieved by passing the @code{#:name-services} argument to
19907 @code{nscd-service} the list of packages providing the needed name
19908 services (@pxref{Base Services, @code{nscd-service}}).
19911 An action specified using the @code{lookup-specification} macro
19912 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
19913 Reference Manual}). For example:
19916 (lookup-specification (unavailable => continue)
19917 (success => return))
19922 @node Initial RAM Disk
19923 @subsection Initial RAM Disk
19926 @cindex initial RAM disk
19927 For bootstrapping purposes, the Linux-Libre kernel is passed an
19928 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
19929 root file system as well as an initialization script. The latter is
19930 responsible for mounting the real root file system, and for loading any
19931 kernel modules that may be needed to achieve that.
19933 The @code{initrd-modules} field of an @code{operating-system}
19934 declaration allows you to specify Linux-libre kernel modules that must
19935 be available in the initrd. In particular, this is where you would list
19936 modules needed to actually drive the hard disk where your root partition
19937 is---although the default value of @code{initrd-modules} should cover
19938 most use cases. For example, assuming you need the @code{megaraid_sas}
19939 module in addition to the default modules to be able to access your root
19940 file system, you would write:
19945 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
19948 @defvr {Scheme Variable} %base-initrd-modules
19949 This is the list of kernel modules included in the initrd by default.
19952 Furthermore, if you need lower-level customization, the @code{initrd}
19953 field of an @code{operating-system} declaration allows
19954 you to specify which initrd you would like to use. The @code{(gnu
19955 system linux-initrd)} module provides three ways to build an initrd: the
19956 high-level @code{base-initrd} procedure and the low-level
19957 @code{raw-initrd} and @code{expression->initrd} procedures.
19959 The @code{base-initrd} procedure is intended to cover most common uses.
19960 For example, if you want to add a bunch of kernel modules to be loaded
19961 at boot time, you can define the @code{initrd} field of the operating
19962 system declaration like this:
19965 (initrd (lambda (file-systems . rest)
19966 ;; Create a standard initrd but set up networking
19967 ;; with the parameters QEMU expects by default.
19968 (apply base-initrd file-systems
19969 #:qemu-networking? #t
19973 The @code{base-initrd} procedure also handles common use cases that
19974 involves using the system as a QEMU guest, or as a ``live'' system with
19975 volatile root file system.
19977 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
19978 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
19979 such as trying to guess which kernel modules and packages should be included
19980 to the initrd. An example use of @code{raw-initrd} is when a user has
19981 a custom Linux kernel configuration and default kernel modules included by
19982 @code{base-initrd} are not available.
19984 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
19985 honors several options passed on the Linux kernel command line
19986 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
19987 @code{-append} option of QEMU), notably:
19990 @item --load=@var{boot}
19991 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
19992 program, once it has mounted the root file system.
19994 GuixSD uses this option to yield control to a boot program that runs the
19995 service activation programs and then spawns the GNU@tie{}Shepherd, the
19996 initialization system.
19998 @item --root=@var{root}
19999 Mount @var{root} as the root file system. @var{root} can be a
20000 device name like @code{/dev/sda1}, a file system label, or a file system
20003 @item --system=@var{system}
20004 Have @file{/run/booted-system} and @file{/run/current-system} point to
20007 @item modprobe.blacklist=@var{modules}@dots{}
20008 @cindex module, black-listing
20009 @cindex black list, of kernel modules
20010 Instruct the initial RAM disk as well as the @command{modprobe} command
20011 (from the kmod package) to refuse to load @var{modules}. @var{modules}
20012 must be a comma-separated list of module names---e.g.,
20013 @code{usbkbd,9pnet}.
20016 Start a read-eval-print loop (REPL) from the initial RAM disk before it
20017 tries to load kernel modules and to mount the root file system. Our
20018 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
20019 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
20020 Manual}, for more information on Guile's REPL.
20024 Now that you know all the features that initial RAM disks produced by
20025 @code{base-initrd} and @code{raw-initrd} provide,
20026 here is how to use it and customize it further.
20029 @cindex initial RAM disk
20030 @deffn {Monadic Procedure} raw-initrd @var{file-systems} @
20031 [#:linux-modules '()] [#:mapped-devices '()] @
20032 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
20033 Return a monadic derivation that builds a raw initrd. @var{file-systems} is
20034 a list of file systems to be mounted by the initrd, possibly in addition to
20035 the root file system specified on the kernel command line via @code{--root}.
20036 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
20037 @var{mapped-devices} is a list of device mappings to realize before
20038 @var{file-systems} are mounted (@pxref{Mapped Devices}).
20039 @var{helper-packages} is a list of packages to be copied in the initrd. It may
20040 include @code{e2fsck/static} or other packages needed by the initrd to check
20041 the root file system.
20043 When @var{qemu-networking?} is true, set up networking with the standard QEMU
20044 parameters. When @var{virtio?} is true, load additional modules so that the
20045 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
20047 When @var{volatile-root?} is true, the root file system is writable but any changes
20051 @deffn {Monadic Procedure} base-initrd @var{file-systems} @
20052 [#:mapped-devices '()] [#:qemu-networking? #f] [#:volatile-root? #f]@
20053 [#:linux-modules '()]
20054 Return a monadic derivation that builds a generic initrd, with kernel
20055 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
20056 mounted by the initrd, possibly in addition to the root file system specified
20057 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
20058 mappings to realize before @var{file-systems} are mounted.
20060 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
20062 The initrd is automatically populated with all the kernel modules necessary
20063 for @var{file-systems} and for the given options. Additional kernel
20064 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
20065 loaded at boot time in the order in which they appear.
20068 Needless to say, the initrds we produce and use embed a
20069 statically-linked Guile, and the initialization program is a Guile
20070 program. That gives a lot of flexibility. The
20071 @code{expression->initrd} procedure builds such an initrd, given the
20072 program to run in that initrd.
20074 @deffn {Monadic Procedure} expression->initrd @var{exp} @
20075 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
20076 Return a derivation that builds a Linux initrd (a gzipped cpio archive)
20077 containing @var{guile} and that evaluates @var{exp}, a G-expression,
20078 upon booting. All the derivations referenced by @var{exp} are
20079 automatically copied to the initrd.
20082 @node Bootloader Configuration
20083 @subsection Bootloader Configuration
20086 @cindex boot loader
20088 The operating system supports multiple bootloaders. The bootloader is
20089 configured using @code{bootloader-configuration} declaration. All the
20090 fields of this structure are bootloader agnostic except for one field,
20091 @code{bootloader} that indicates the bootloader to be configured and
20094 Some of the bootloaders do not honor every field of
20095 @code{bootloader-configuration}. For instance, the extlinux
20096 bootloader does not support themes and thus ignores the @code{theme}
20099 @deftp {Data Type} bootloader-configuration
20100 The type of a bootloader configuration declaration.
20104 @item @code{bootloader}
20105 @cindex EFI, bootloader
20106 @cindex UEFI, bootloader
20107 @cindex BIOS, bootloader
20108 The bootloader to use, as a @code{bootloader} object. For now
20109 @code{grub-bootloader}, @code{grub-efi-bootloader},
20110 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
20111 @code{grub-efi-bootloader} allows to boot on modern systems using the
20112 @dfn{Unified Extensible Firmware Interface} (UEFI).
20114 Available bootloaders are described in @code{(gnu bootloader @dots{})}
20117 @item @code{target}
20118 This is a string denoting the target onto which to install the
20119 bootloader. The exact interpretation depends on the bootloader in
20120 question; for @code{grub-bootloader}, for example, it should be a device
20121 name understood by the bootloader @command{installer} command, such as
20122 @code{/dev/sda} or @code{(hd0)} (for GRUB, @pxref{Invoking
20123 grub-install,,, grub, GNU GRUB Manual}). For
20124 @code{grub-efi-bootloader}, it should be the path to a mounted EFI file
20127 @item @code{menu-entries} (default: @code{()})
20128 A possibly empty list of @code{menu-entry} objects (see below), denoting
20129 entries to appear in the bootloader menu, in addition to the current
20130 system entry and the entry pointing to previous system generations.
20132 @item @code{default-entry} (default: @code{0})
20133 The index of the default boot menu entry. Index 0 is for the entry of the
20136 @item @code{timeout} (default: @code{5})
20137 The number of seconds to wait for keyboard input before booting. Set to
20138 0 to boot immediately, and to -1 to wait indefinitely.
20140 @item @code{theme} (default: @var{#f})
20141 The bootloader theme object describing the theme to use. If no theme
20142 is provided, some bootloaders might use a default theme, that's true
20145 @item @code{terminal-outputs} (default: @code{'gfxterm})
20146 The output terminals used for the bootloader boot menu, as a list of
20147 symbols. GRUB accepts the values: @code{console}, @code{serial},
20148 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
20149 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
20150 corresponds to the GRUB variable GRUB_TERMINAL_OUTPUT (@pxref{Simple
20151 configuration,,, grub,GNU GRUB manual}).
20153 @item @code{terminal-inputs} (default: @code{'()})
20154 The input terminals used for the bootloader boot menu, as a list of
20155 symbols. For GRUB, the default is the native platform terminal as
20156 determined at run-time. GRUB accepts the values: @code{console},
20157 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
20158 @code{usb_keyboard}. This field corresponds to the GRUB variable
20159 GRUB_TERMINAL_INPUT (@pxref{Simple configuration,,, grub,GNU GRUB
20162 @item @code{serial-unit} (default: @code{#f})
20163 The serial unit used by the bootloader, as an integer from 0 to 3.
20164 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
20165 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
20167 @item @code{serial-speed} (default: @code{#f})
20168 The speed of the serial interface, as an integer. For GRUB, the
20169 default value is chosen at run-time; currently GRUB chooses
20170 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
20177 Should you want to list additional boot menu entries @i{via} the
20178 @code{menu-entries} field above, you will need to create them with the
20179 @code{menu-entry} form. For example, imagine you want to be able to
20180 boot another distro (hard to imagine!), you can define a menu entry
20185 (label "The Other Distro")
20186 (linux "/boot/old/vmlinux-2.6.32")
20187 (linux-arguments '("root=/dev/sda2"))
20188 (initrd "/boot/old/initrd"))
20193 @deftp {Data Type} menu-entry
20194 The type of an entry in the bootloader menu.
20199 The label to show in the menu---e.g., @code{"GNU"}.
20202 The Linux kernel image to boot, for example:
20205 (file-append linux-libre "/bzImage")
20208 For GRUB, it is also possible to specify a device explicitly in the
20209 file path using GRUB's device naming convention (@pxref{Naming
20210 convention,,, grub, GNU GRUB manual}), for example:
20213 "(hd0,msdos1)/boot/vmlinuz"
20216 If the device is specified explicitly as above, then the @code{device}
20217 field is ignored entirely.
20219 @item @code{linux-arguments} (default: @code{()})
20220 The list of extra Linux kernel command-line arguments---e.g.,
20221 @code{("console=ttyS0")}.
20223 @item @code{initrd}
20224 A G-Expression or string denoting the file name of the initial RAM disk
20225 to use (@pxref{G-Expressions}).
20226 @item @code{device} (default: @code{#f})
20227 The device where the kernel and initrd are to be found---i.e., for GRUB,
20228 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
20230 This may be a file system label (a string), a file system UUID (a
20231 bytevector, @pxref{File Systems}), or @code{#f}, in which case
20232 the bootloader will search the device containing the file specified by
20233 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
20234 must @emph{not} be an OS device name such as @file{/dev/sda1}.
20239 @c FIXME: Write documentation once it's stable.
20240 Fow now only GRUB has theme support. GRUB themes are created using
20241 the @code{grub-theme} form, which is not documented yet.
20243 @defvr {Scheme Variable} %default-theme
20244 This is the default GRUB theme used by the operating system if no
20245 @code{theme} field is specified in @code{bootloader-configuration}
20248 It comes with a fancy background image displaying the GNU and Guix
20253 @node Invoking guix system
20254 @subsection Invoking @code{guix system}
20256 Once you have written an operating system declaration as seen in the
20257 previous section, it can be @dfn{instantiated} using the @command{guix
20258 system} command. The synopsis is:
20261 guix system @var{options}@dots{} @var{action} @var{file}
20264 @var{file} must be the name of a file containing an
20265 @code{operating-system} declaration. @var{action} specifies how the
20266 operating system is instantiated. Currently the following values are
20271 Display available service type definitions that match the given regular
20272 expressions, sorted by relevance:
20275 $ guix system search console font
20276 name: console-fonts
20277 location: gnu/services/base.scm:729:2
20278 extends: shepherd-root
20279 description: Install the given fonts on the specified ttys (fonts are
20280 + per virtual console on GNU/Linux). The value of this service is a list
20281 + of tty/font pairs like:
20283 + '(("tty1" . "LatGrkCyr-8x16"))
20287 location: gnu/services/base.scm:1048:2
20288 extends: shepherd-root
20289 description: Provide console login using the `mingetty' program.
20293 location: gnu/services/base.scm:775:2
20295 description: Provide a console log-in service as specified by its
20296 + configuration value, a `login-configuration' object.
20302 As for @command{guix package --search}, the result is written in
20303 @code{recutils} format, which makes it easy to filter the output
20304 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
20307 Build the operating system described in @var{file}, activate it, and
20308 switch to it@footnote{This action (and the related actions
20309 @code{switch-generation} and @code{roll-back}) are usable only on
20310 systems already running GuixSD.}.
20312 This effects all the configuration specified in @var{file}: user
20313 accounts, system services, global package list, setuid programs, etc.
20314 The command starts system services specified in @var{file} that are not
20315 currently running; if a service is currently running, it does not
20316 attempt to upgrade it since this would not be possible without stopping it
20319 This command creates a new generation whose number is one greater than
20320 the current generation (as reported by @command{guix system
20321 list-generations}). If that generation already exists, it will be
20322 overwritten. This behavior mirrors that of @command{guix package}
20323 (@pxref{Invoking guix package}).
20325 It also adds a bootloader menu entry for the new OS configuration,
20326 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
20327 entries for older configurations to a submenu, allowing you to choose
20328 an older system generation at boot time should you need it.
20331 @c The paragraph below refers to the problem discussed at
20332 @c <http://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
20333 It is highly recommended to run @command{guix pull} once before you run
20334 @command{guix system reconfigure} for the first time (@pxref{Invoking
20335 guix pull}). Failing to do that you would see an older version of Guix
20336 once @command{reconfigure} has completed.
20339 @item switch-generation
20340 @cindex generations
20341 Switch to an existing system generation. This action atomically
20342 switches the system profile to the specified system generation. It
20343 also rearranges the system's existing bootloader menu entries. It
20344 makes the menu entry for the specified system generation the default,
20345 and it moves the entries for the other generatiors to a submenu, if
20346 supported by the bootloader being used. The next time the system
20347 boots, it will use the specified system generation.
20349 The bootloader itself is not being reinstalled when using this
20350 command. Thus, the installed bootloader is used with an updated
20351 configuration file.
20353 The target generation can be specified explicitly by its generation
20354 number. For example, the following invocation would switch to system
20358 guix system switch-generation 7
20361 The target generation can also be specified relative to the current
20362 generation with the form @code{+N} or @code{-N}, where @code{+3} means
20363 ``3 generations ahead of the current generation,'' and @code{-1} means
20364 ``1 generation prior to the current generation.'' When specifying a
20365 negative value such as @code{-1}, you must precede it with @code{--} to
20366 prevent it from being parsed as an option. For example:
20369 guix system switch-generation -- -1
20372 Currently, the effect of invoking this action is @emph{only} to switch
20373 the system profile to an existing generation and rearrange the
20374 bootloader menu entries. To actually start using the target system
20375 generation, you must reboot after running this action. In the future,
20376 it will be updated to do the same things as @command{reconfigure},
20377 like activating and deactivating services.
20379 This action will fail if the specified generation does not exist.
20382 @cindex rolling back
20383 Switch to the preceding system generation. The next time the system
20384 boots, it will use the preceding system generation. This is the inverse
20385 of @command{reconfigure}, and it is exactly the same as invoking
20386 @command{switch-generation} with an argument of @code{-1}.
20388 Currently, as with @command{switch-generation}, you must reboot after
20389 running this action to actually start using the preceding system
20393 Build the derivation of the operating system, which includes all the
20394 configuration files and programs needed to boot and run the system.
20395 This action does not actually install anything.
20398 Populate the given directory with all the files necessary to run the
20399 operating system specified in @var{file}. This is useful for first-time
20400 installations of GuixSD. For instance:
20403 guix system init my-os-config.scm /mnt
20406 copies to @file{/mnt} all the store items required by the configuration
20407 specified in @file{my-os-config.scm}. This includes configuration
20408 files, packages, and so on. It also creates other essential files
20409 needed for the system to operate correctly---e.g., the @file{/etc},
20410 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
20412 This command also installs bootloader on the target specified in
20413 @file{my-os-config}, unless the @option{--no-bootloader} option was
20417 @cindex virtual machine
20419 @anchor{guix system vm}
20420 Build a virtual machine that contains the operating system declared in
20421 @var{file}, and return a script to run that virtual machine (VM).
20422 Arguments given to the script are passed to QEMU as in the example
20423 below, which enables networking and requests 1@tie{}GiB of RAM for the
20427 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
20430 The VM shares its store with the host system.
20432 Additional file systems can be shared between the host and the VM using
20433 the @code{--share} and @code{--expose} command-line options: the former
20434 specifies a directory to be shared with write access, while the latter
20435 provides read-only access to the shared directory.
20437 The example below creates a VM in which the user's home directory is
20438 accessible read-only, and where the @file{/exchange} directory is a
20439 read-write mapping of @file{$HOME/tmp} on the host:
20442 guix system vm my-config.scm \
20443 --expose=$HOME --share=$HOME/tmp=/exchange
20446 On GNU/Linux, the default is to boot directly to the kernel; this has
20447 the advantage of requiring only a very tiny root disk image since the
20448 store of the host can then be mounted.
20450 The @code{--full-boot} option forces a complete boot sequence, starting
20451 with the bootloader. This requires more disk space since a root image
20452 containing at least the kernel, initrd, and bootloader data files must
20453 be created. The @code{--image-size} option can be used to specify the
20456 @cindex System images, creation in various formats
20457 @cindex Creating system images in various formats
20460 @itemx docker-image
20461 Return a virtual machine, disk image, or Docker image of the operating
20462 system declared in @var{file} that stands alone. By default,
20463 @command{guix system} estimates the size of the image needed to store
20464 the system, but you can use the @option{--image-size} option to specify
20465 a value. Docker images are built to contain exactly what they need, so
20466 the @option{--image-size} option is ignored in the case of
20467 @code{docker-image}.
20469 You can specify the root file system type by using the
20470 @option{--file-system-type} option. It defaults to @code{ext4}.
20472 When using @code{vm-image}, the returned image is in qcow2 format, which
20473 the QEMU emulator can efficiently use. @xref{Running GuixSD in a VM},
20474 for more information on how to run the image in a virtual machine.
20476 When using @code{disk-image}, a raw disk image is produced; it can be
20477 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
20478 the device corresponding to a USB stick, one can copy the image to it
20479 using the following command:
20482 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
20485 When using @code{docker-image}, a Docker image is produced. Guix builds
20486 the image from scratch, not from a pre-existing Docker base image. As a
20487 result, it contains @emph{exactly} what you define in the operating
20488 system configuration file. You can then load the image and launch a
20489 Docker container using commands like the following:
20492 image_id="$(docker load < guixsd-docker-image.tar.gz)"
20493 docker run -e GUIX_NEW_SYSTEM=/var/guix/profiles/system \\
20494 --entrypoint /var/guix/profiles/system/profile/bin/guile \\
20495 $image_id /var/guix/profiles/system/boot
20498 This command starts a new Docker container from the specified image. It
20499 will boot the GuixSD system in the usual manner, which means it will
20500 start any services you have defined in the operating system
20501 configuration. Depending on what you run in the Docker container, it
20502 may be necessary to give the container additional permissions. For
20503 example, if you intend to build software using Guix inside of the Docker
20504 container, you may need to pass the @option{--privileged} option to
20508 Return a script to run the operating system declared in @var{file}
20509 within a container. Containers are a set of lightweight isolation
20510 mechanisms provided by the kernel Linux-libre. Containers are
20511 substantially less resource-demanding than full virtual machines since
20512 the kernel, shared objects, and other resources can be shared with the
20513 host system; this also means they provide thinner isolation.
20515 Currently, the script must be run as root in order to support more than
20516 a single user and group. The container shares its store with the host
20519 As with the @code{vm} action (@pxref{guix system vm}), additional file
20520 systems to be shared between the host and container can be specified
20521 using the @option{--share} and @option{--expose} options:
20524 guix system container my-config.scm \
20525 --expose=$HOME --share=$HOME/tmp=/exchange
20529 This option requires Linux-libre 3.19 or newer.
20534 @var{options} can contain any of the common build options (@pxref{Common
20535 Build Options}). In addition, @var{options} can contain one of the
20539 @item --expression=@var{expr}
20540 @itemx -e @var{expr}
20541 Consider the operating-system @var{expr} evaluates to.
20542 This is an alternative to specifying a file which evaluates to an
20544 This is used to generate the GuixSD installer @pxref{Building the
20545 Installation Image}).
20547 @item --system=@var{system}
20548 @itemx -s @var{system}
20549 Attempt to build for @var{system} instead of the host system type.
20550 This works as per @command{guix build} (@pxref{Invoking guix build}).
20554 Return the derivation file name of the given operating system without
20557 @item --file-system-type=@var{type}
20558 @itemx -t @var{type}
20559 For the @code{disk-image} action, create a file system of the given
20560 @var{type} on the image.
20562 When this option is omitted, @command{guix system} uses @code{ext4}.
20564 @cindex ISO-9660 format
20565 @cindex CD image format
20566 @cindex DVD image format
20567 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
20568 for burning on CDs and DVDs.
20570 @item --image-size=@var{size}
20571 For the @code{vm-image} and @code{disk-image} actions, create an image
20572 of the given @var{size}. @var{size} may be a number of bytes, or it may
20573 include a unit as a suffix (@pxref{Block size, size specifications,,
20574 coreutils, GNU Coreutils}).
20576 When this option is omitted, @command{guix system} computes an estimate
20577 of the image size as a function of the size of the system declared in
20580 @item --root=@var{file}
20581 @itemx -r @var{file}
20582 Make @var{file} a symlink to the result, and register it as a garbage
20585 @item --skip-checks
20586 Skip pre-installation safety checks.
20588 By default, @command{guix system init} and @command{guix system
20589 reconfigure} perform safety checks: they make sure the file systems that
20590 appear in the @code{operating-system} declaration actually exist
20591 (@pxref{File Systems}), and that any Linux kernel modules that may be
20592 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
20593 RAM Disk}). Passing this option skips these tests altogether.
20595 @item --on-error=@var{strategy}
20596 Apply @var{strategy} when an error occurs when reading @var{file}.
20597 @var{strategy} may be one of the following:
20600 @item nothing-special
20601 Report the error concisely and exit. This is the default strategy.
20604 Likewise, but also display a backtrace.
20607 Report the error and enter Guile's debugger. From there, you can run
20608 commands such as @code{,bt} to get a backtrace, @code{,locals} to
20609 display local variable values, and more generally inspect the state of the
20610 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
20611 a list of available debugging commands.
20616 All the actions above, except @code{build} and @code{init},
20617 can use KVM support in the Linux-libre kernel. Specifically, if the
20618 machine has hardware virtualization support, the corresponding
20619 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
20620 must exist and be readable and writable by the user and by the
20621 build users of the daemon (@pxref{Build Environment Setup}).
20624 Once you have built, configured, re-configured, and re-re-configured
20625 your GuixSD installation, you may find it useful to list the operating
20626 system generations available on disk---and that you can choose from the
20627 bootloader boot menu:
20631 @item list-generations
20632 List a summary of each generation of the operating system available on
20633 disk, in a human-readable way. This is similar to the
20634 @option{--list-generations} option of @command{guix package}
20635 (@pxref{Invoking guix package}).
20637 Optionally, one can specify a pattern, with the same syntax that is used
20638 in @command{guix package --list-generations}, to restrict the list of
20639 generations displayed. For instance, the following command displays
20640 generations that are up to 10 days old:
20643 $ guix system list-generations 10d
20648 The @command{guix system} command has even more to offer! The following
20649 sub-commands allow you to visualize how your system services relate to
20652 @anchor{system-extension-graph}
20655 @item extension-graph
20656 Emit in Dot/Graphviz format to standard output the @dfn{service
20657 extension graph} of the operating system defined in @var{file}
20658 (@pxref{Service Composition}, for more information on service
20664 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
20667 produces a PDF file showing the extension relations among services.
20669 @anchor{system-shepherd-graph}
20670 @item shepherd-graph
20671 Emit in Dot/Graphviz format to standard output the @dfn{dependency
20672 graph} of shepherd services of the operating system defined in
20673 @var{file}. @xref{Shepherd Services}, for more information and for an
20678 @node Running GuixSD in a VM
20679 @subsection Running GuixSD in a Virtual Machine
20681 @cindex virtual machine
20682 To run GuixSD in a virtual machine (VM), one can either use the
20683 pre-built GuixSD VM image distributed at
20684 @indicateurl{ftp://alpha.gnu.org/guix/guixsd-vm-image-@value{VERSION}.@var{system}.tar.xz}
20685 , or build their own virtual machine image using @command{guix system
20686 vm-image} (@pxref{Invoking guix system}). The returned image is in
20687 qcow2 format, which the @uref{http://qemu.org/, QEMU emulator} can
20691 If you built your own image, you must copy it out of the store
20692 (@pxref{The Store}) and give yourself permission to write to the copy
20693 before you can use it. When invoking QEMU, you must choose a system
20694 emulator that is suitable for your hardware platform. Here is a minimal
20695 QEMU invocation that will boot the result of @command{guix system
20696 vm-image} on x86_64 hardware:
20699 $ qemu-system-x86_64 \
20700 -net user -net nic,model=virtio \
20701 -enable-kvm -m 256 /tmp/qemu-image
20704 Here is what each of these options means:
20707 @item qemu-system-x86_64
20708 This specifies the hardware platform to emulate. This should match the
20712 Enable the unprivileged user-mode network stack. The guest OS can
20713 access the host but not vice versa. This is the simplest way to get the
20716 @item -net nic,model=virtio
20717 You must create a network interface of a given model. If you do not
20718 create a NIC, the boot will fail. Assuming your hardware platform is
20719 x86_64, you can get a list of available NIC models by running
20720 @command{qemu-system-x86_64 -net nic,model=help}.
20723 If your system has hardware virtualization extensions, enabling the
20724 virtual machine support (KVM) of the Linux kernel will make things run
20728 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
20729 which may be insufficient for some operations.
20731 @item /tmp/qemu-image
20732 The file name of the qcow2 image.
20735 The default @command{run-vm.sh} script that is returned by an invocation of
20736 @command{guix system vm} does not add a @command{-net user} flag by default.
20737 To get network access from within the vm add the @code{(dhcp-client-service)}
20738 to your system definition and start the VM using
20739 @command{`guix system vm config.scm` -net user}. An important caveat of using
20740 @command{-net user} for networking is that @command{ping} will not work, because
20741 it uses the ICMP protocol. You'll have to use a different command to check for
20742 network connectivity, for example @command{guix download}.
20744 @subsubsection Connecting Through SSH
20748 To enable SSH inside a VM you need to add a SSH server like @code{(dropbear-service)}
20749 or @code{(lsh-service)} to your VM. The @code{(lsh-service}) doesn't currently
20750 boot unsupervised. It requires you to type some characters to initialize the
20751 randomness generator. In addition you need to forward the SSH port, 22 by
20752 default, to the host. You can do this with
20755 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
20758 To connect to the VM you can run
20761 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
20764 The @command{-p} tells @command{ssh} the port you want to connect to.
20765 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
20766 every time you modify your @command{config.scm} file and the
20767 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
20768 connection to an unknown host every time you connect.
20770 @subsubsection Using @command{virt-viewer} with Spice
20772 As an alternative to the default @command{qemu} graphical client you can
20773 use the @command{remote-viewer} from the @command{virt-viewer} package. To
20774 connect pass the @command{-spice port=5930,disable-ticketing} flag to
20775 @command{qemu}. See previous section for further information on how to do this.
20777 Spice also allows you to do some nice stuff like share your clipboard with your
20778 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
20781 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
20782 -chardev spicevmc,name=vdagent,id=vdagent
20783 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
20784 name=com.redhat.spice.0
20787 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
20789 @node Defining Services
20790 @subsection Defining Services
20792 The previous sections show the available services and how one can combine
20793 them in an @code{operating-system} declaration. But how do we define
20794 them in the first place? And what is a service anyway?
20797 * Service Composition:: The model for composing services.
20798 * Service Types and Services:: Types and services.
20799 * Service Reference:: API reference.
20800 * Shepherd Services:: A particular type of service.
20803 @node Service Composition
20804 @subsubsection Service Composition
20808 Here we define a @dfn{service} as, broadly, something that extends the
20809 functionality of the operating system. Often a service is a process---a
20810 @dfn{daemon}---started when the system boots: a secure shell server, a
20811 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
20812 whose execution can be triggered by another daemon---e.g., an FTP server
20813 started by @command{inetd} or a D-Bus service activated by
20814 @command{dbus-daemon}. Occasionally, a service does not map to a
20815 daemon. For instance, the ``account'' service collects user accounts
20816 and makes sure they exist when the system runs; the ``udev'' service
20817 collects device management rules and makes them available to the eudev
20818 daemon; the @file{/etc} service populates the @file{/etc} directory
20821 @cindex service extensions
20822 GuixSD services are connected by @dfn{extensions}. For instance, the
20823 secure shell service @emph{extends} the Shepherd---the GuixSD
20824 initialization system, running as PID@tie{}1---by giving it the command
20825 lines to start and stop the secure shell daemon (@pxref{Networking
20826 Services, @code{lsh-service}}); the UPower service extends the D-Bus
20827 service by passing it its @file{.service} specification, and extends the
20828 udev service by passing it device management rules (@pxref{Desktop
20829 Services, @code{upower-service}}); the Guix daemon service extends the
20830 Shepherd by passing it the command lines to start and stop the daemon,
20831 and extends the account service by passing it a list of required build
20832 user accounts (@pxref{Base Services}).
20834 All in all, services and their ``extends'' relations form a directed
20835 acyclic graph (DAG). If we represent services as boxes and extensions
20836 as arrows, a typical system might provide something like this:
20838 @image{images/service-graph,,5in,Typical service extension graph.}
20840 @cindex system service
20841 At the bottom, we see the @dfn{system service}, which produces the
20842 directory containing everything to run and boot the system, as returned
20843 by the @command{guix system build} command. @xref{Service Reference},
20844 to learn about the other service types shown here.
20845 @xref{system-extension-graph, the @command{guix system extension-graph}
20846 command}, for information on how to generate this representation for a
20847 particular operating system definition.
20849 @cindex service types
20850 Technically, developers can define @dfn{service types} to express these
20851 relations. There can be any number of services of a given type on the
20852 system---for instance, a system running two instances of the GNU secure
20853 shell server (lsh) has two instances of @var{lsh-service-type}, with
20854 different parameters.
20856 The following section describes the programming interface for service
20857 types and services.
20859 @node Service Types and Services
20860 @subsubsection Service Types and Services
20862 A @dfn{service type} is a node in the DAG described above. Let us start
20863 with a simple example, the service type for the Guix build daemon
20864 (@pxref{Invoking guix-daemon}):
20867 (define guix-service-type
20871 (list (service-extension shepherd-root-service-type guix-shepherd-service)
20872 (service-extension account-service-type guix-accounts)
20873 (service-extension activation-service-type guix-activation)))
20874 (default-value (guix-configuration))))
20878 It defines three things:
20882 A name, whose sole purpose is to make inspection and debugging easier.
20885 A list of @dfn{service extensions}, where each extension designates the
20886 target service type and a procedure that, given the parameters of the
20887 service, returns a list of objects to extend the service of that type.
20889 Every service type has at least one service extension. The only
20890 exception is the @dfn{boot service type}, which is the ultimate service.
20893 Optionally, a default value for instances of this type.
20896 In this example, @var{guix-service-type} extends three services:
20899 @item shepherd-root-service-type
20900 The @var{guix-shepherd-service} procedure defines how the Shepherd
20901 service is extended. Namely, it returns a @code{<shepherd-service>}
20902 object that defines how @command{guix-daemon} is started and stopped
20903 (@pxref{Shepherd Services}).
20905 @item account-service-type
20906 This extension for this service is computed by @var{guix-accounts},
20907 which returns a list of @code{user-group} and @code{user-account}
20908 objects representing the build user accounts (@pxref{Invoking
20911 @item activation-service-type
20912 Here @var{guix-activation} is a procedure that returns a gexp, which is
20913 a code snippet to run at ``activation time''---e.g., when the service is
20917 A service of this type is instantiated like this:
20920 (service guix-service-type
20921 (guix-configuration
20923 (use-substitutes? #f)))
20926 The second argument to the @code{service} form is a value representing
20927 the parameters of this specific service instance.
20928 @xref{guix-configuration-type, @code{guix-configuration}}, for
20929 information about the @code{guix-configuration} data type. When the
20930 value is omitted, the default value specified by
20931 @code{guix-service-type} is used:
20934 (service guix-service-type)
20937 @var{guix-service-type} is quite simple because it extends other
20938 services but is not extensible itself.
20940 @c @subsubsubsection Extensible Service Types
20942 The service type for an @emph{extensible} service looks like this:
20945 (define udev-service-type
20946 (service-type (name 'udev)
20948 (list (service-extension shepherd-root-service-type
20949 udev-shepherd-service)))
20951 (compose concatenate) ;concatenate the list of rules
20952 (extend (lambda (config rules)
20954 (($ <udev-configuration> udev initial-rules)
20955 (udev-configuration
20956 (udev udev) ;the udev package to use
20957 (rules (append initial-rules rules)))))))))
20960 This is the service type for the
20961 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
20962 management daemon}. Compared to the previous example, in addition to an
20963 extension of @var{shepherd-root-service-type}, we see two new fields:
20967 This is the procedure to @dfn{compose} the list of extensions to
20968 services of this type.
20970 Services can extend the udev service by passing it lists of rules; we
20971 compose those extensions simply by concatenating them.
20974 This procedure defines how the value of the service is @dfn{extended} with
20975 the composition of the extensions.
20977 Udev extensions are composed into a list of rules, but the udev service
20978 value is itself a @code{<udev-configuration>} record. So here, we
20979 extend that record by appending the list of rules it contains to the
20980 list of contributed rules.
20983 This is a string giving an overview of the service type. The string can
20984 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
20985 @command{guix system search} command searches these strings and displays
20986 them (@pxref{Invoking guix system}).
20989 There can be only one instance of an extensible service type such as
20990 @var{udev-service-type}. If there were more, the
20991 @code{service-extension} specifications would be ambiguous.
20993 Still here? The next section provides a reference of the programming
20994 interface for services.
20996 @node Service Reference
20997 @subsubsection Service Reference
20999 We have seen an overview of service types (@pxref{Service Types and
21000 Services}). This section provides a reference on how to manipulate
21001 services and service types. This interface is provided by the
21002 @code{(gnu services)} module.
21004 @deffn {Scheme Procedure} service @var{type} [@var{value}]
21005 Return a new service of @var{type}, a @code{<service-type>} object (see
21006 below.) @var{value} can be any object; it represents the parameters of
21007 this particular service instance.
21009 When @var{value} is omitted, the default value specified by @var{type}
21010 is used; if @var{type} does not specify a default value, an error is
21013 For instance, this:
21016 (service openssh-service-type)
21020 is equivalent to this:
21023 (service openssh-service-type
21024 (openssh-configuration))
21027 In both cases the result is an instance of @code{openssh-service-type}
21028 with the default configuration.
21031 @deffn {Scheme Procedure} service? @var{obj}
21032 Return true if @var{obj} is a service.
21035 @deffn {Scheme Procedure} service-kind @var{service}
21036 Return the type of @var{service}---i.e., a @code{<service-type>} object.
21039 @deffn {Scheme Procedure} service-value @var{service}
21040 Return the value associated with @var{service}. It represents its
21044 Here is an example of how a service is created and manipulated:
21048 (service nginx-service-type
21049 (nginx-configuration
21051 (log-directory log-directory)
21052 (run-directory run-directory)
21053 (file config-file))))
21058 (eq? (service-kind s) nginx-service-type)
21062 The @code{modify-services} form provides a handy way to change the
21063 parameters of some of the services of a list such as
21064 @var{%base-services} (@pxref{Base Services, @code{%base-services}}). It
21065 evaluates to a list of services. Of course, you could always use
21066 standard list combinators such as @code{map} and @code{fold} to do that
21067 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
21068 @code{modify-services} simply provides a more concise form for this
21071 @deffn {Scheme Syntax} modify-services @var{services} @
21072 (@var{type} @var{variable} => @var{body}) @dots{}
21074 Modify the services listed in @var{services} according to the given
21075 clauses. Each clause has the form:
21078 (@var{type} @var{variable} => @var{body})
21081 where @var{type} is a service type---e.g.,
21082 @code{guix-service-type}---and @var{variable} is an identifier that is
21083 bound within the @var{body} to the service parameters---e.g., a
21084 @code{guix-configuration} instance---of the original service of that
21087 The @var{body} should evaluate to the new service parameters, which will
21088 be used to configure the new service. This new service will replace the
21089 original in the resulting list. Because a service's service parameters
21090 are created using @code{define-record-type*}, you can write a succinct
21091 @var{body} that evaluates to the new service parameters by using the
21092 @code{inherit} feature that @code{define-record-type*} provides.
21094 @xref{Using the Configuration System}, for example usage.
21098 Next comes the programming interface for service types. This is
21099 something you want to know when writing new service definitions, but not
21100 necessarily when simply looking for ways to customize your
21101 @code{operating-system} declaration.
21103 @deftp {Data Type} service-type
21104 @cindex service type
21105 This is the representation of a @dfn{service type} (@pxref{Service Types
21110 This is a symbol, used only to simplify inspection and debugging.
21112 @item @code{extensions}
21113 A non-empty list of @code{<service-extension>} objects (see below).
21115 @item @code{compose} (default: @code{#f})
21116 If this is @code{#f}, then the service type denotes services that cannot
21117 be extended---i.e., services that do not receive ``values'' from other
21120 Otherwise, it must be a one-argument procedure. The procedure is called
21121 by @code{fold-services} and is passed a list of values collected from
21122 extensions. It may return any single value.
21124 @item @code{extend} (default: @code{#f})
21125 If this is @code{#f}, services of this type cannot be extended.
21127 Otherwise, it must be a two-argument procedure: @code{fold-services}
21128 calls it, passing it the initial value of the service as the first
21129 argument and the result of applying @code{compose} to the extension
21130 values as the second argument. It must return a value that is a valid
21131 parameter value for the service instance.
21134 @xref{Service Types and Services}, for examples.
21137 @deffn {Scheme Procedure} service-extension @var{target-type} @
21139 Return a new extension for services of type @var{target-type}.
21140 @var{compute} must be a one-argument procedure: @code{fold-services}
21141 calls it, passing it the value associated with the service that provides
21142 the extension; it must return a valid value for the target service.
21145 @deffn {Scheme Procedure} service-extension? @var{obj}
21146 Return true if @var{obj} is a service extension.
21149 Occasionally, you might want to simply extend an existing service. This
21150 involves creating a new service type and specifying the extension of
21151 interest, which can be verbose; the @code{simple-service} procedure
21152 provides a shorthand for this.
21154 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
21155 Return a service that extends @var{target} with @var{value}. This works
21156 by creating a singleton service type @var{name}, of which the returned
21157 service is an instance.
21159 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
21163 (simple-service 'my-mcron-job mcron-service-type
21164 #~(job '(next-hour (3)) "guix gc -F 2G"))
21168 At the core of the service abstraction lies the @code{fold-services}
21169 procedure, which is responsible for ``compiling'' a list of services
21170 down to a single directory that contains everything needed to boot and
21171 run the system---the directory shown by the @command{guix system build}
21172 command (@pxref{Invoking guix system}). In essence, it propagates
21173 service extensions down the service graph, updating each node parameters
21174 on the way, until it reaches the root node.
21176 @deffn {Scheme Procedure} fold-services @var{services} @
21177 [#:target-type @var{system-service-type}]
21178 Fold @var{services} by propagating their extensions down to the root of
21179 type @var{target-type}; return the root service adjusted accordingly.
21182 Lastly, the @code{(gnu services)} module also defines several essential
21183 service types, some of which are listed below.
21185 @defvr {Scheme Variable} system-service-type
21186 This is the root of the service graph. It produces the system directory
21187 as returned by the @command{guix system build} command.
21190 @defvr {Scheme Variable} boot-service-type
21191 The type of the ``boot service'', which produces the @dfn{boot script}.
21192 The boot script is what the initial RAM disk runs when booting.
21195 @defvr {Scheme Variable} etc-service-type
21196 The type of the @file{/etc} service. This service is used to create
21197 files under @file{/etc} and can be extended by
21198 passing it name/file tuples such as:
21201 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
21204 In this example, the effect would be to add an @file{/etc/issue} file
21205 pointing to the given file.
21208 @defvr {Scheme Variable} setuid-program-service-type
21209 Type for the ``setuid-program service''. This service collects lists of
21210 executable file names, passed as gexps, and adds them to the set of
21211 setuid-root programs on the system (@pxref{Setuid Programs}).
21214 @defvr {Scheme Variable} profile-service-type
21215 Type of the service that populates the @dfn{system profile}---i.e., the
21216 programs under @file{/run/current-system/profile}. Other services can
21217 extend it by passing it lists of packages to add to the system profile.
21221 @node Shepherd Services
21222 @subsubsection Shepherd Services
21224 @cindex shepherd services
21226 @cindex init system
21227 The @code{(gnu services shepherd)} module provides a way to define
21228 services managed by the GNU@tie{}Shepherd, which is the GuixSD
21229 initialization system---the first process that is started when the
21230 system boots, also known as PID@tie{}1
21231 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
21233 Services in the Shepherd can depend on each other. For instance, the
21234 SSH daemon may need to be started after the syslog daemon has been
21235 started, which in turn can only happen once all the file systems have
21236 been mounted. The simple operating system defined earlier (@pxref{Using
21237 the Configuration System}) results in a service graph like this:
21239 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
21241 You can actually generate such a graph for any operating system
21242 definition using the @command{guix system shepherd-graph} command
21243 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
21245 The @var{%shepherd-root-service} is a service object representing
21246 PID@tie{}1, of type @var{shepherd-root-service-type}; it can be extended
21247 by passing it lists of @code{<shepherd-service>} objects.
21249 @deftp {Data Type} shepherd-service
21250 The data type representing a service managed by the Shepherd.
21253 @item @code{provision}
21254 This is a list of symbols denoting what the service provides.
21256 These are the names that may be passed to @command{herd start},
21257 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
21258 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
21259 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
21261 @item @code{requirements} (default: @code{'()})
21262 List of symbols denoting the Shepherd services this one depends on.
21264 @item @code{respawn?} (default: @code{#t})
21265 Whether to restart the service when it stops, for instance when the
21266 underlying process dies.
21269 @itemx @code{stop} (default: @code{#~(const #f)})
21270 The @code{start} and @code{stop} fields refer to the Shepherd's
21271 facilities to start and stop processes (@pxref{Service De- and
21272 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
21273 G-expressions that get expanded in the Shepherd configuration file
21274 (@pxref{G-Expressions}).
21276 @item @code{documentation}
21277 A documentation string, as shown when running:
21280 herd doc @var{service-name}
21283 where @var{service-name} is one of the symbols in @var{provision}
21284 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
21286 @item @code{modules} (default: @var{%default-modules})
21287 This is the list of modules that must be in scope when @code{start} and
21288 @code{stop} are evaluated.
21293 @defvr {Scheme Variable} shepherd-root-service-type
21294 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
21296 This is the service type that extensions target when they want to create
21297 shepherd services (@pxref{Service Types and Services}, for an example).
21298 Each extension must pass a list of @code{<shepherd-service>}.
21301 @defvr {Scheme Variable} %shepherd-root-service
21302 This service represents PID@tie{}1.
21306 @node Documentation
21307 @section Documentation
21309 @cindex documentation, searching for
21310 @cindex searching for documentation
21311 @cindex Info, documentation format
21313 @cindex manual pages
21314 In most cases packages installed with Guix come with documentation.
21315 There are two main documentation formats: ``Info'', a browseable
21316 hypertext format used for GNU software, and ``manual pages'' (or ``man
21317 pages''), the linear documentation format traditionally found on Unix.
21318 Info manuals are accessed with the @command{info} command or with Emacs,
21319 and man pages are accessed using @command{man}.
21321 You can look for documentation of software installed on your system by
21322 keyword. For example, the following command searches for information
21323 about ``TLS'' in Info manuals:
21327 "(emacs)Network Security" -- STARTTLS
21328 "(emacs)Network Security" -- TLS
21329 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
21330 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
21335 The command below searches for the same keyword in man pages:
21339 SSL (7) - OpenSSL SSL/TLS library
21340 certtool (1) - GnuTLS certificate tool
21344 These searches are purely local to your computer so you have the
21345 guarantee that documentation you find corresponds to what you have
21346 actually installed, you can access it off-line, and your privacy is
21349 Once you have these results, you can view the relevant documentation by
21353 $ info "(gnutls)Core TLS API"
21363 Info manuals contain sections and indices as well as hyperlinks like
21364 those found in Web pages. The @command{info} reader (@pxref{Top, Info
21365 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
21366 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
21367 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
21368 Introduction}, for an introduction to Info navigation.
21370 @node Installing Debugging Files
21371 @section Installing Debugging Files
21373 @cindex debugging files
21374 Program binaries, as produced by the GCC compilers for instance, are
21375 typically written in the ELF format, with a section containing
21376 @dfn{debugging information}. Debugging information is what allows the
21377 debugger, GDB, to map binary code to source code; it is required to
21378 debug a compiled program in good conditions.
21380 The problem with debugging information is that is takes up a fair amount
21381 of disk space. For example, debugging information for the GNU C Library
21382 weighs in at more than 60 MiB. Thus, as a user, keeping all the
21383 debugging info of all the installed programs is usually not an option.
21384 Yet, space savings should not come at the cost of an impediment to
21385 debugging---especially in the GNU system, which should make it easier
21386 for users to exert their computing freedom (@pxref{GNU Distribution}).
21388 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
21389 mechanism that allows users to get the best of both worlds: debugging
21390 information can be stripped from the binaries and stored in separate
21391 files. GDB is then able to load debugging information from those files,
21392 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
21395 The GNU distribution takes advantage of this by storing debugging
21396 information in the @code{lib/debug} sub-directory of a separate package
21397 output unimaginatively called @code{debug} (@pxref{Packages with
21398 Multiple Outputs}). Users can choose to install the @code{debug} output
21399 of a package when they need it. For instance, the following command
21400 installs the debugging information for the GNU C Library and for GNU
21404 guix package -i glibc:debug guile:debug
21407 GDB must then be told to look for debug files in the user's profile, by
21408 setting the @code{debug-file-directory} variable (consider setting it
21409 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
21413 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
21416 From there on, GDB will pick up debugging information from the
21417 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
21419 In addition, you will most likely want GDB to be able to show the source
21420 code being debugged. To do that, you will have to unpack the source
21421 code of the package of interest (obtained with @code{guix build
21422 --source}, @pxref{Invoking guix build}), and to point GDB to that source
21423 directory using the @code{directory} command (@pxref{Source Path,
21424 @code{directory},, gdb, Debugging with GDB}).
21426 @c XXX: keep me up-to-date
21427 The @code{debug} output mechanism in Guix is implemented by the
21428 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
21429 opt-in---debugging information is available only for the packages
21430 with definitions explicitly declaring a @code{debug} output. This may be
21431 changed to opt-out in the future if our build farm servers can handle
21432 the load. To check whether a package has a @code{debug} output, use
21433 @command{guix package --list-available} (@pxref{Invoking guix package}).
21436 @node Security Updates
21437 @section Security Updates
21439 @cindex security updates
21440 @cindex security vulnerabilities
21441 Occasionally, important security vulnerabilities are discovered in software
21442 packages and must be patched. Guix developers try hard to keep track of
21443 known vulnerabilities and to apply fixes as soon as possible in the
21444 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
21445 containing only security updates.) The @command{guix lint} tool helps
21446 developers find out about vulnerable versions of software packages in the
21451 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
21452 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
21453 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
21457 @xref{Invoking guix lint}, for more information.
21460 As of version @value{VERSION}, the feature described below is considered
21464 Guix follows a functional
21465 package management discipline (@pxref{Introduction}), which implies
21466 that, when a package is changed, @emph{every package that depends on it}
21467 must be rebuilt. This can significantly slow down the deployment of
21468 fixes in core packages such as libc or Bash, since basically the whole
21469 distribution would need to be rebuilt. Using pre-built binaries helps
21470 (@pxref{Substitutes}), but deployment may still take more time than
21474 To address this, Guix implements @dfn{grafts}, a mechanism that allows
21475 for fast deployment of critical updates without the costs associated
21476 with a whole-distribution rebuild. The idea is to rebuild only the
21477 package that needs to be patched, and then to ``graft'' it onto packages
21478 explicitly installed by the user and that were previously referring to
21479 the original package. The cost of grafting is typically very low, and
21480 order of magnitudes lower than a full rebuild of the dependency chain.
21482 @cindex replacements of packages, for grafts
21483 For instance, suppose a security update needs to be applied to Bash.
21484 Guix developers will provide a package definition for the ``fixed''
21485 Bash, say @var{bash-fixed}, in the usual way (@pxref{Defining
21486 Packages}). Then, the original package definition is augmented with a
21487 @code{replacement} field pointing to the package containing the bug fix:
21494 (replacement bash-fixed)))
21497 From there on, any package depending directly or indirectly on Bash---as
21498 reported by @command{guix gc --requisites} (@pxref{Invoking guix
21499 gc})---that is installed is automatically ``rewritten'' to refer to
21500 @var{bash-fixed} instead of @var{bash}. This grafting process takes
21501 time proportional to the size of the package, usually less than a
21502 minute for an ``average'' package on a recent machine. Grafting is
21503 recursive: when an indirect dependency requires grafting, then grafting
21504 ``propagates'' up to the package that the user is installing.
21506 Currently, the length of the name and version of the graft and that of
21507 the package it replaces (@var{bash-fixed} and @var{bash} in the example
21508 above) must be equal. This restriction mostly comes from the fact that
21509 grafting works by patching files, including binary files, directly.
21510 Other restrictions may apply: for instance, when adding a graft to a
21511 package providing a shared library, the original shared library and its
21512 replacement must have the same @code{SONAME} and be binary-compatible.
21514 The @option{--no-grafts} command-line option allows you to forcefully
21515 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
21519 guix build bash --no-grafts
21523 returns the store file name of the original Bash, whereas:
21530 returns the store file name of the ``fixed'', replacement Bash. This
21531 allows you to distinguish between the two variants of Bash.
21533 To verify which Bash your whole profile refers to, you can run
21534 (@pxref{Invoking guix gc}):
21537 guix gc -R `readlink -f ~/.guix-profile` | grep bash
21541 @dots{} and compare the store file names that you get with those above.
21542 Likewise for a complete GuixSD system generation:
21545 guix gc -R `guix system build my-config.scm` | grep bash
21548 Lastly, to check which Bash running processes are using, you can use the
21549 @command{lsof} command:
21552 lsof | grep /gnu/store/.*bash
21556 @node Package Modules
21557 @section Package Modules
21559 From a programming viewpoint, the package definitions of the
21560 GNU distribution are provided by Guile modules in the @code{(gnu packages
21561 @dots{})} name space@footnote{Note that packages under the @code{(gnu
21562 packages @dots{})} module name space are not necessarily ``GNU
21563 packages''. This module naming scheme follows the usual Guile module
21564 naming convention: @code{gnu} means that these modules are distributed
21565 as part of the GNU system, and @code{packages} identifies modules that
21566 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
21567 Reference Manual}). For instance, the @code{(gnu packages emacs)}
21568 module exports a variable named @code{emacs}, which is bound to a
21569 @code{<package>} object (@pxref{Defining Packages}).
21571 The @code{(gnu packages @dots{})} module name space is
21572 automatically scanned for packages by the command-line tools. For
21573 instance, when running @code{guix package -i emacs}, all the @code{(gnu
21574 packages @dots{})} modules are scanned until one that exports a package
21575 object whose name is @code{emacs} is found. This package search
21576 facility is implemented in the @code{(gnu packages)} module.
21578 @cindex customization, of packages
21579 @cindex package module search path
21580 Users can store package definitions in modules with different
21581 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
21582 name and module name must match. For instance, the @code{(my-packages
21583 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
21584 relative to the load path specified with @option{--load-path} or
21585 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
21586 guile, GNU Guile Reference Manual}, for details.}. These package definitions
21587 will not be visible by default. Users can invoke commands such as
21588 @command{guix package} and @command{guix build} with the
21589 @code{-e} option so that they know where to find the package. Better
21590 yet, they can use the
21591 @code{-L} option of these commands to make those modules visible
21592 (@pxref{Invoking guix build, @code{--load-path}}), or define the
21593 @code{GUIX_PACKAGE_PATH} environment variable. This environment
21594 variable makes it easy to extend or customize the distribution and is
21595 honored by all the user interfaces.
21597 @defvr {Environment Variable} GUIX_PACKAGE_PATH
21598 This is a colon-separated list of directories to search for additional
21599 package modules. Directories listed in this variable take precedence
21600 over the own modules of the distribution.
21603 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
21604 each package is built based solely on other packages in the
21605 distribution. The root of this dependency graph is a small set of
21606 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
21607 bootstrap)} module. For more information on bootstrapping,
21608 @pxref{Bootstrapping}.
21610 @node Packaging Guidelines
21611 @section Packaging Guidelines
21613 @cindex packages, creating
21614 The GNU distribution is nascent and may well lack some of your favorite
21615 packages. This section describes how you can help make the distribution
21616 grow. @xref{Contributing}, for additional information on how you can
21619 Free software packages are usually distributed in the form of
21620 @dfn{source code tarballs}---typically @file{tar.gz} files that contain
21621 all the source files. Adding a package to the distribution means
21622 essentially two things: adding a @dfn{recipe} that describes how to
21623 build the package, including a list of other packages required to build
21624 it, and adding @dfn{package metadata} along with that recipe, such as a
21625 description and licensing information.
21627 In Guix all this information is embodied in @dfn{package definitions}.
21628 Package definitions provide a high-level view of the package. They are
21629 written using the syntax of the Scheme programming language; in fact,
21630 for each package we define a variable bound to the package definition,
21631 and export that variable from a module (@pxref{Package Modules}).
21632 However, in-depth Scheme knowledge is @emph{not} a prerequisite for
21633 creating packages. For more information on package definitions,
21634 @pxref{Defining Packages}.
21636 Once a package definition is in place, stored in a file in the Guix
21637 source tree, it can be tested using the @command{guix build} command
21638 (@pxref{Invoking guix build}). For example, assuming the new package is
21639 called @code{gnew}, you may run this command from the Guix build tree
21640 (@pxref{Running Guix Before It Is Installed}):
21643 ./pre-inst-env guix build gnew --keep-failed
21646 Using @code{--keep-failed} makes it easier to debug build failures since
21647 it provides access to the failed build tree. Another useful
21648 command-line option when debugging is @code{--log-file}, to access the
21651 If the package is unknown to the @command{guix} command, it may be that
21652 the source file contains a syntax error, or lacks a @code{define-public}
21653 clause to export the package variable. To figure it out, you may load
21654 the module from Guile to get more information about the actual error:
21657 ./pre-inst-env guile -c '(use-modules (gnu packages gnew))'
21660 Once your package builds correctly, please send us a patch
21661 (@pxref{Contributing}). Well, if you need help, we will be happy to
21662 help you too. Once the patch is committed in the Guix repository, the
21663 new package automatically gets built on the supported platforms by
21664 @url{http://hydra.gnu.org/jobset/gnu/master, our continuous integration
21667 @cindex substituter
21668 Users can obtain the new package definition simply by running
21669 @command{guix pull} (@pxref{Invoking guix pull}). When
21670 @code{hydra.gnu.org} is done building the package, installing the
21671 package automatically downloads binaries from there
21672 (@pxref{Substitutes}). The only place where human intervention is
21673 needed is to review and apply the patch.
21677 * Software Freedom:: What may go into the distribution.
21678 * Package Naming:: What's in a name?
21679 * Version Numbers:: When the name is not enough.
21680 * Synopses and Descriptions:: Helping users find the right package.
21681 * Python Modules:: A touch of British comedy.
21682 * Perl Modules:: Little pearls.
21683 * Java Packages:: Coffee break.
21684 * Fonts:: Fond of fonts.
21687 @node Software Freedom
21688 @subsection Software Freedom
21690 @c Adapted from http://www.gnu.org/philosophy/philosophy.html.
21691 @cindex free software
21692 The GNU operating system has been developed so that users can have
21693 freedom in their computing. GNU is @dfn{free software}, meaning that
21694 users have the @url{http://www.gnu.org/philosophy/free-sw.html,four
21695 essential freedoms}: to run the program, to study and change the program
21696 in source code form, to redistribute exact copies, and to distribute
21697 modified versions. Packages found in the GNU distribution provide only
21698 software that conveys these four freedoms.
21700 In addition, the GNU distribution follow the
21701 @url{http://www.gnu.org/distros/free-system-distribution-guidelines.html,free
21702 software distribution guidelines}. Among other things, these guidelines
21703 reject non-free firmware, recommendations of non-free software, and
21704 discuss ways to deal with trademarks and patents.
21706 Some otherwise free upstream package sources contain a small and optional
21707 subset that violates the above guidelines, for instance because this subset
21708 is itself non-free code. When that happens, the offending items are removed
21709 with appropriate patches or code snippets in the @code{origin} form of the
21710 package (@pxref{Defining Packages}). This way, @code{guix
21711 build --source} returns the ``freed'' source rather than the unmodified
21715 @node Package Naming
21716 @subsection Package Naming
21718 @cindex package name
21719 A package has actually two names associated with it:
21720 First, there is the name of the @emph{Scheme variable}, the one following
21721 @code{define-public}. By this name, the package can be made known in the
21722 Scheme code, for instance as input to another package. Second, there is
21723 the string in the @code{name} field of a package definition. This name
21724 is used by package management commands such as
21725 @command{guix package} and @command{guix build}.
21727 Both are usually the same and correspond to the lowercase conversion of
21728 the project name chosen upstream, with underscores replaced with
21729 hyphens. For instance, GNUnet is available as @code{gnunet}, and
21730 SDL_net as @code{sdl-net}.
21732 We do not add @code{lib} prefixes for library packages, unless these are
21733 already part of the official project name. But @pxref{Python
21734 Modules} and @ref{Perl Modules} for special rules concerning modules for
21735 the Python and Perl languages.
21737 Font package names are handled differently, @pxref{Fonts}.
21740 @node Version Numbers
21741 @subsection Version Numbers
21743 @cindex package version
21744 We usually package only the latest version of a given free software
21745 project. But sometimes, for instance for incompatible library versions,
21746 two (or more) versions of the same package are needed. These require
21747 different Scheme variable names. We use the name as defined
21748 in @ref{Package Naming}
21749 for the most recent version; previous versions use the same name, suffixed
21750 by @code{-} and the smallest prefix of the version number that may
21751 distinguish the two versions.
21753 The name inside the package definition is the same for all versions of a
21754 package and does not contain any version number.
21756 For instance, the versions 2.24.20 and 3.9.12 of GTK+ may be packaged as follows:
21759 (define-public gtk+
21764 (define-public gtk+-2
21767 (version "2.24.20")
21770 If we also wanted GTK+ 3.8.2, this would be packaged as
21772 (define-public gtk+-3.8
21779 @c See <https://lists.gnu.org/archive/html/guix-devel/2016-01/msg00425.html>,
21780 @c for a discussion of what follows.
21781 @cindex version number, for VCS snapshots
21782 Occasionally, we package snapshots of upstream's version control system
21783 (VCS) instead of formal releases. This should remain exceptional,
21784 because it is up to upstream developers to clarify what the stable
21785 release is. Yet, it is sometimes necessary. So, what should we put in
21786 the @code{version} field?
21788 Clearly, we need to make the commit identifier of the VCS snapshot
21789 visible in the version string, but we also need to make sure that the
21790 version string is monotonically increasing so that @command{guix package
21791 --upgrade} can determine which version is newer. Since commit
21792 identifiers, notably with Git, are not monotonically increasing, we add
21793 a revision number that we increase each time we upgrade to a newer
21794 snapshot. The resulting version string looks like this:
21799 | | `-- upstream commit ID
21801 | `--- Guix package revision
21803 latest upstream version
21806 It is a good idea to strip commit identifiers in the @code{version}
21807 field to, say, 7 digits. It avoids an aesthetic annoyance (assuming
21808 aesthetics have a role to play here) as well as problems related to OS
21809 limits such as the maximum shebang length (127 bytes for the Linux
21810 kernel.) It is best to use the full commit identifiers in
21811 @code{origin}s, though, to avoid ambiguities. A typical package
21812 definition may look like this:
21816 (let ((commit "c3f29bc928d5900971f65965feaae59e1272a3f7")
21817 (revision "1")) ;Guix package revision
21819 (version (git-version "0.9" revision commit))
21822 (uri (git-reference
21823 (url "git://example.org/my-package.git")
21825 (sha256 (base32 "1mbikn@dots{}"))
21826 (file-name (git-file-name name version))))
21831 @node Synopses and Descriptions
21832 @subsection Synopses and Descriptions
21834 @cindex package description
21835 @cindex package synopsis
21836 As we have seen before, each package in GNU@tie{}Guix includes a
21837 synopsis and a description (@pxref{Defining Packages}). Synopses and
21838 descriptions are important: They are what @command{guix package
21839 --search} searches, and a crucial piece of information to help users
21840 determine whether a given package suits their needs. Consequently,
21841 packagers should pay attention to what goes into them.
21843 Synopses must start with a capital letter and must not end with a
21844 period. They must not start with ``a'' or ``the'', which usually does
21845 not bring anything; for instance, prefer ``File-frobbing tool'' over ``A
21846 tool that frobs files''. The synopsis should say what the package
21847 is---e.g., ``Core GNU utilities (file, text, shell)''---or what it is
21848 used for---e.g., the synopsis for GNU@tie{}grep is ``Print lines
21849 matching a pattern''.
21851 Keep in mind that the synopsis must be meaningful for a very wide
21852 audience. For example, ``Manipulate alignments in the SAM format''
21853 might make sense for a seasoned bioinformatics researcher, but might be
21854 fairly unhelpful or even misleading to a non-specialized audience. It
21855 is a good idea to come up with a synopsis that gives an idea of the
21856 application domain of the package. In this example, this might give
21857 something like ``Manipulate nucleotide sequence alignments'', which
21858 hopefully gives the user a better idea of whether this is what they are
21861 Descriptions should take between five and ten lines. Use full
21862 sentences, and avoid using acronyms without first introducing them.
21863 Please avoid marketing phrases such as ``world-leading'',
21864 ``industrial-strength'', and ``next-generation'', and avoid superlatives
21865 like ``the most advanced''---they are not helpful to users looking for a
21866 package and may even sound suspicious. Instead, try to be factual,
21867 mentioning use cases and features.
21869 @cindex Texinfo markup, in package descriptions
21870 Descriptions can include Texinfo markup, which is useful to introduce
21871 ornaments such as @code{@@code} or @code{@@dfn}, bullet lists, or
21872 hyperlinks (@pxref{Overview,,, texinfo, GNU Texinfo}). However you
21873 should be careful when using some characters for example @samp{@@} and
21874 curly braces which are the basic special characters in Texinfo
21875 (@pxref{Special Characters,,, texinfo, GNU Texinfo}). User interfaces
21876 such as @command{guix package --show} take care of rendering it
21879 Synopses and descriptions are translated by volunteers
21880 @uref{http://translationproject.org/domain/guix-packages.html, at the
21881 Translation Project} so that as many users as possible can read them in
21882 their native language. User interfaces search them and display them in
21883 the language specified by the current locale.
21885 To allow @command{xgettext} to extract them as translatable strings,
21886 synopses and descriptions @emph{must be literal strings}. This means
21887 that you cannot use @code{string-append} or @code{format} to construct
21893 (synopsis "This is translatable")
21894 (description (string-append "This is " "*not*" " translatable.")))
21897 Translation is a lot of work so, as a packager, please pay even more
21898 attention to your synopses and descriptions as every change may entail
21899 additional work for translators. In order to help them, it is possible
21900 to make recommendations or instructions visible to them by inserting
21901 special comments like this (@pxref{xgettext Invocation,,, gettext, GNU
21905 ;; TRANSLATORS: "X11 resize-and-rotate" should not be translated.
21906 (description "ARandR is designed to provide a simple visual front end
21907 for the X11 resize-and-rotate (RandR) extension. @dots{}")
21911 @node Python Modules
21912 @subsection Python Modules
21915 We currently package Python 2 and Python 3, under the Scheme variable names
21916 @code{python-2} and @code{python} as explained in @ref{Version Numbers}.
21917 To avoid confusion and naming clashes with other programming languages, it
21918 seems desirable that the name of a package for a Python module contains
21919 the word @code{python}.
21921 Some modules are compatible with only one version of Python, others with both.
21922 If the package Foo compiles only with Python 3, we name it
21923 @code{python-foo}; if it compiles only with Python 2, we name it
21924 @code{python2-foo}. If it is compatible with both versions, we create two
21925 packages with the corresponding names.
21927 If a project already contains the word @code{python}, we drop this;
21928 for instance, the module python-dateutil is packaged under the names
21929 @code{python-dateutil} and @code{python2-dateutil}. If the project name
21930 starts with @code{py} (e.g. @code{pytz}), we keep it and prefix it as
21933 @subsubsection Specifying Dependencies
21934 @cindex inputs, for Python packages
21936 Dependency information for Python packages is usually available in the
21937 package source tree, with varying degrees of accuracy: in the
21938 @file{setup.py} file, in @file{requirements.txt}, or in @file{tox.ini}.
21940 Your mission, when writing a recipe for a Python package, is to map
21941 these dependencies to the appropriate type of ``input'' (@pxref{package
21942 Reference, inputs}). Although the @code{pypi} importer normally does a
21943 good job (@pxref{Invoking guix import}), you may want to check the
21944 following check list to determine which dependency goes where.
21949 We currently package Python 2 with @code{setuptools} and @code{pip}
21950 installed like Python 3.4 has per default. Thus you don't need to
21951 specify either of these as an input. @command{guix lint} will warn you
21955 Python dependencies required at run time go into
21956 @code{propagated-inputs}. They are typically defined with the
21957 @code{install_requires} keyword in @file{setup.py}, or in the
21958 @file{requirements.txt} file.
21961 Python packages required only at build time---e.g., those listed with
21962 the @code{setup_requires} keyword in @file{setup.py}---or only for
21963 testing---e.g., those in @code{tests_require}---go into
21964 @code{native-inputs}. The rationale is that (1) they do not need to be
21965 propagated because they are not needed at run time, and (2) in a
21966 cross-compilation context, it's the ``native'' input that we'd want.
21968 Examples are the @code{pytest}, @code{mock}, and @code{nose} test
21969 frameworks. Of course if any of these packages is also required at
21970 run-time, it needs to go to @code{propagated-inputs}.
21973 Anything that does not fall in the previous categories goes to
21974 @code{inputs}, for example programs or C libraries required for building
21975 Python packages containing C extensions.
21978 If a Python package has optional dependencies (@code{extras_require}),
21979 it is up to you to decide whether to add them or not, based on their
21980 usefulness/overhead ratio (@pxref{Submitting Patches, @command{guix
21987 @subsection Perl Modules
21990 Perl programs standing for themselves are named as any other package,
21991 using the lowercase upstream name.
21992 For Perl packages containing a single class, we use the lowercase class name,
21993 replace all occurrences of @code{::} by dashes and prepend the prefix
21995 So the class @code{XML::Parser} becomes @code{perl-xml-parser}.
21996 Modules containing several classes keep their lowercase upstream name and
21997 are also prepended by @code{perl-}. Such modules tend to have the word
21998 @code{perl} somewhere in their name, which gets dropped in favor of the
21999 prefix. For instance, @code{libwww-perl} becomes @code{perl-libwww}.
22002 @node Java Packages
22003 @subsection Java Packages
22006 Java programs standing for themselves are named as any other package,
22007 using the lowercase upstream name.
22009 To avoid confusion and naming clashes with other programming languages,
22010 it is desirable that the name of a package for a Java package is
22011 prefixed with @code{java-}. If a project already contains the word
22012 @code{java}, we drop this; for instance, the package @code{ngsjava} is
22013 packaged under the name @code{java-ngs}.
22015 For Java packages containing a single class or a small class hierarchy,
22016 we use the lowercase class name, replace all occurrences of @code{.} by
22017 dashes and prepend the prefix @code{java-}. So the class
22018 @code{apache.commons.cli} becomes package
22019 @code{java-apache-commons-cli}.
22026 For fonts that are in general not installed by a user for typesetting
22027 purposes, or that are distributed as part of a larger software package,
22028 we rely on the general packaging rules for software; for instance, this
22029 applies to the fonts delivered as part of the X.Org system or fonts that
22030 are part of TeX Live.
22032 To make it easier for a user to search for fonts, names for other packages
22033 containing only fonts are constructed as follows, independently of the
22034 upstream package name.
22036 The name of a package containing only one font family starts with
22037 @code{font-}; it is followed by the foundry name and a dash @code{-}
22038 if the foundry is known, and the font family name, in which spaces are
22039 replaced by dashes (and as usual, all upper case letters are transformed
22041 For example, the Gentium font family by SIL is packaged under the name
22042 @code{font-sil-gentium}.
22044 For a package containing several font families, the name of the collection
22045 is used in the place of the font family name.
22046 For instance, the Liberation fonts consist of three families,
22047 Liberation Sans, Liberation Serif and Liberation Mono.
22048 These could be packaged separately under the names
22049 @code{font-liberation-sans} and so on; but as they are distributed together
22050 under a common name, we prefer to package them together as
22051 @code{font-liberation}.
22053 In the case where several formats of the same font family or font collection
22054 are packaged separately, a short form of the format, prepended by a dash,
22055 is added to the package name. We use @code{-ttf} for TrueType fonts,
22056 @code{-otf} for OpenType fonts and @code{-type1} for PostScript Type 1
22061 @node Bootstrapping
22062 @section Bootstrapping
22064 @c Adapted from the ELS 2013 paper.
22066 @cindex bootstrapping
22068 Bootstrapping in our context refers to how the distribution gets built
22069 ``from nothing''. Remember that the build environment of a derivation
22070 contains nothing but its declared inputs (@pxref{Introduction}). So
22071 there's an obvious chicken-and-egg problem: how does the first package
22072 get built? How does the first compiler get compiled? Note that this is
22073 a question of interest only to the curious hacker, not to the regular
22074 user, so you can shamelessly skip this section if you consider yourself
22075 a ``regular user''.
22077 @cindex bootstrap binaries
22078 The GNU system is primarily made of C code, with libc at its core. The
22079 GNU build system itself assumes the availability of a Bourne shell and
22080 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
22081 `grep'. Furthermore, build programs---programs that run
22082 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
22083 (@pxref{Derivations}). Consequently, to be able to build anything at
22084 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
22085 Binutils, libc, and the other packages mentioned above---the
22086 @dfn{bootstrap binaries}.
22088 These bootstrap binaries are ``taken for granted'', though we can also
22089 re-create them if needed (more on that later).
22091 @unnumberedsubsec Preparing to Use the Bootstrap Binaries
22093 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
22094 @c large image, it's hard to scroll. Oh well.
22095 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
22097 The figure above shows the very beginning of the dependency graph of the
22098 distribution, corresponding to the package definitions of the @code{(gnu
22099 packages bootstrap)} module. A similar figure can be generated with
22100 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
22103 guix graph -t derivation \
22104 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
22108 At this level of detail, things are
22109 slightly complex. First, Guile itself consists of an ELF executable,
22110 along with many source and compiled Scheme files that are dynamically
22111 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
22112 tarball shown in this graph. This tarball is part of Guix's ``source''
22113 distribution, and gets inserted into the store with @code{add-to-store}
22114 (@pxref{The Store}).
22116 But how do we write a derivation that unpacks this tarball and adds it
22117 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
22118 derivation---the first one that gets built---uses @code{bash} as its
22119 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
22120 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
22121 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
22122 the Guix source distribution, whose sole purpose is to allow the Guile
22123 tarball to be unpacked.
22125 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
22126 Guile that can be used to run subsequent build programs. Its first task
22127 is to download tarballs containing the other pre-built binaries---this
22128 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
22129 @code{ftp-client.scm} are used for this purpose. The
22130 @code{module-import.drv} derivations import those modules in a directory
22131 in the store, using the original layout. The
22132 @code{module-import-compiled.drv} derivations compile those modules, and
22133 write them in an output directory with the right layout. This
22134 corresponds to the @code{#:modules} argument of
22135 @code{build-expression->derivation} (@pxref{Derivations}).
22137 Finally, the various tarballs are unpacked by the
22138 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
22139 etc., at which point we have a working C tool chain.
22142 @unnumberedsubsec Building the Build Tools
22144 Bootstrapping is complete when we have a full tool chain that does not
22145 depend on the pre-built bootstrap tools discussed above. This
22146 no-dependency requirement is verified by checking whether the files of
22147 the final tool chain contain references to the @file{/gnu/store}
22148 directories of the bootstrap inputs. The process that leads to this
22149 ``final'' tool chain is described by the package definitions found in
22150 the @code{(gnu packages commencement)} module.
22152 The @command{guix graph} command allows us to ``zoom out'' compared to
22153 the graph above, by looking at the level of package objects instead of
22154 individual derivations---remember that a package may translate to
22155 several derivations, typically one derivation to download its source,
22156 one to build the Guile modules it needs, and one to actually build the
22157 package from source. The command:
22160 guix graph -t bag \
22161 -e '(@@@@ (gnu packages commencement)
22162 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
22166 produces the dependency graph leading to the ``final'' C
22167 library@footnote{You may notice the @code{glibc-intermediate} label,
22168 suggesting that it is not @emph{quite} final, but as a good
22169 approximation, we will consider it final.}, depicted below.
22171 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
22173 @c See <http://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
22174 The first tool that gets built with the bootstrap binaries is
22175 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
22176 for all the following packages. From there Findutils and Diffutils get
22179 Then come the first-stage Binutils and GCC, built as pseudo cross
22180 tools---i.e., with @code{--target} equal to @code{--host}. They are
22181 used to build libc. Thanks to this cross-build trick, this libc is
22182 guaranteed not to hold any reference to the initial tool chain.
22184 From there the final Binutils and GCC (not shown above) are built.
22186 from the final Binutils, and links programs against the just-built libc.
22187 This tool chain is used to build the other packages used by Guix and by
22188 the GNU Build System: Guile, Bash, Coreutils, etc.
22190 And voilà! At this point we have the complete set of build tools that
22191 the GNU Build System expects. These are in the @code{%final-inputs}
22192 variable of the @code{(gnu packages commencement)} module, and are
22193 implicitly used by any package that uses @code{gnu-build-system}
22194 (@pxref{Build Systems, @code{gnu-build-system}}).
22197 @unnumberedsubsec Building the Bootstrap Binaries
22199 @cindex bootstrap binaries
22200 Because the final tool chain does not depend on the bootstrap binaries,
22201 those rarely need to be updated. Nevertheless, it is useful to have an
22202 automated way to produce them, should an update occur, and this is what
22203 the @code{(gnu packages make-bootstrap)} module provides.
22205 The following command builds the tarballs containing the bootstrap
22206 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
22207 of Coreutils and other basic command-line tools):
22210 guix build bootstrap-tarballs
22213 The generated tarballs are those that should be referred to in the
22214 @code{(gnu packages bootstrap)} module mentioned at the beginning of
22217 Still here? Then perhaps by now you've started to wonder: when do we
22218 reach a fixed point? That is an interesting question! The answer is
22219 unknown, but if you would like to investigate further (and have
22220 significant computational and storage resources to do so), then let us
22223 @unnumberedsubsec Reducing the Set of Bootstrap Binaries
22225 Our bootstrap binaries currently include GCC, Guile, etc. That's a lot
22226 of binary code! Why is that a problem? It's a problem because these
22227 big chunks of binary code are practically non-auditable, which makes it
22228 hard to establish what source code produced them. Every unauditable
22229 binary also leaves us vulnerable to compiler backdoors as described by
22230 Ken Thompson in the 1984 paper @emph{Reflections on Trusting Trust}.
22232 This is mitigated by the fact that our bootstrap binaries were generated
22233 from an earlier Guix revision. Nevertheless it lacks the level of
22234 transparency that we get in the rest of the package dependency graph,
22235 where Guix always gives us a source-to-binary mapping. Thus, our goal
22236 is to reduce the set of bootstrap binaries to the bare minimum.
22238 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
22239 on-going projects to do that. One of these is about replacing the
22240 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
22241 of increasing complexity, which could be built from source starting from
22242 a simple and auditable assembler. Your help is welcome!
22246 @section Porting to a New Platform
22248 As discussed above, the GNU distribution is self-contained, and
22249 self-containment is achieved by relying on pre-built ``bootstrap
22250 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
22251 operating system kernel, CPU architecture, and application binary
22252 interface (ABI). Thus, to port the distribution to a platform that is
22253 not yet supported, one must build those bootstrap binaries, and update
22254 the @code{(gnu packages bootstrap)} module to use them on that platform.
22256 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
22257 When everything goes well, and assuming the GNU tool chain supports the
22258 target platform, this can be as simple as running a command like this
22262 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
22265 For this to work, the @code{glibc-dynamic-linker} procedure in
22266 @code{(gnu packages bootstrap)} must be augmented to return the right
22267 file name for libc's dynamic linker on that platform; likewise,
22268 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
22269 taught about the new platform.
22271 Once these are built, the @code{(gnu packages bootstrap)} module needs
22272 to be updated to refer to these binaries on the target platform. That
22273 is, the hashes and URLs of the bootstrap tarballs for the new platform
22274 must be added alongside those of the currently supported platforms. The
22275 bootstrap Guile tarball is treated specially: it is expected to be
22276 available locally, and @file{gnu/local.mk} has rules do download it for
22277 the supported architectures; a rule for the new platform must be added
22280 In practice, there may be some complications. First, it may be that the
22281 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
22282 above) is not recognized by all the GNU tools. Typically, glibc
22283 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
22284 configure flag (see @code{gcc.scm} for examples of how to handle this).
22285 Second, some of the required packages could fail to build for that
22286 platform. Lastly, the generated binaries could be broken for some
22289 @c *********************************************************************
22290 @include contributing.texi
22292 @c *********************************************************************
22293 @node Acknowledgments
22294 @chapter Acknowledgments
22296 Guix is based on the @uref{http://nixos.org/nix/, Nix package manager},
22297 which was designed and
22298 implemented by Eelco Dolstra, with contributions from other people (see
22299 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
22300 management, and promoted unprecedented features, such as transactional
22301 package upgrades and rollbacks, per-user profiles, and referentially
22302 transparent build processes. Without this work, Guix would not exist.
22304 The Nix-based software distributions, Nixpkgs and NixOS, have also been
22305 an inspiration for Guix.
22307 GNU@tie{}Guix itself is a collective work with contributions from a
22308 number of people. See the @file{AUTHORS} file in Guix for more
22309 information on these fine people. The @file{THANKS} file lists people
22310 who have helped by reporting bugs, taking care of the infrastructure,
22311 providing artwork and themes, making suggestions, and more---thank you!
22314 @c *********************************************************************
22315 @node GNU Free Documentation License
22316 @appendix GNU Free Documentation License
22317 @cindex license, GNU Free Documentation License
22318 @include fdl-1.3.texi
22320 @c *********************************************************************
22321 @node Concept Index
22322 @unnumbered Concept Index
22325 @node Programming Index
22326 @unnumbered Programming Index
22327 @syncodeindex tp fn
22328 @syncodeindex vr fn
22333 @c Local Variables:
22334 @c ispell-local-dictionary: "american";