6 @documentencoding UTF-8
7 @settitle GNU Guix Reference Manual
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17 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018 Ludovic Courtès@*
18 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
19 Copyright @copyright{} 2013 Nikita Karetnikov@*
20 Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
21 Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
22 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
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30 Copyright @copyright{} 2016, 2017 Nils Gillmann@*
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33 Copyright @copyright{} 2016 Alex ter Weele@*
34 Copyright @copyright{} 2017, 2018 Clément Lassieur@*
35 Copyright @copyright{} 2017, 2018 Mathieu Othacehe@*
36 Copyright @copyright{} 2017 Federico Beffa@*
37 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
38 Copyright @copyright{} 2017 Thomas Danckaert@*
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41 Copyright @copyright{} 2017, 2018 Marius Bakke@*
42 Copyright @copyright{} 2017 Hartmut Goebel@*
43 Copyright @copyright{} 2017 Maxim Cournoyer@*
44 Copyright @copyright{} 2017, 2018 Tobias Geerinckx-Rice@*
45 Copyright @copyright{} 2017 George Clemmer@*
46 Copyright @copyright{} 2017 Andy Wingo@*
47 Copyright @copyright{} 2017, 2018 Arun Isaac@*
48 Copyright @copyright{} 2017 nee@*
49 Copyright @copyright{} 2018 Rutger Helling@*
50 Copyright @copyright{} 2018 Oleg Pykhalov@*
51 Copyright @copyright{} 2018 Mike Gerwitz@*
52 Copyright @copyright{} 2018 Pierre-Antoine Rouby@*
53 Copyright @copyright{} 2018 Gábor Boskovits@*
54 Copyright @copyright{} 2018 Florian Pelz@*
55 Copyright @copyright{} 2018 Laura Lazzati@*
56 Copyright @copyright{} 2018 Alex Vong@*
58 Permission is granted to copy, distribute and/or modify this document
59 under the terms of the GNU Free Documentation License, Version 1.3 or
60 any later version published by the Free Software Foundation; with no
61 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
62 copy of the license is included in the section entitled ``GNU Free
63 Documentation License''.
66 @dircategory System administration
68 * Guix: (guix). Manage installed software and system configuration.
69 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
70 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
71 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
72 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
75 @dircategory Software development
77 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
78 * guix build: (guix)Invoking guix build. Building packages.
79 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
83 @title GNU Guix Reference Manual
84 @subtitle Using the GNU Guix Functional Package Manager
85 @author The GNU Guix Developers
88 @vskip 0pt plus 1filll
89 Edition @value{EDITION} @*
97 @c *********************************************************************
101 This document describes GNU Guix version @value{VERSION}, a functional
102 package management tool written for the GNU system.
104 @c TRANSLATORS: You can replace the following paragraph with information on
105 @c how to join your own translation team and how to report issues with the
107 This manual is also available in French (@pxref{Top,,, guix.fr, Manuel de
108 référence de GNU Guix}) and German (@pxref{Top,,, guix.de, Referenzhandbuch
109 zu GNU Guix}). If you would like to translate it in your native language,
111 @uref{https://translationproject.org/domain/guix-manual.html, Translation
115 * Introduction:: What is Guix about?
116 * Installation:: Installing Guix.
117 * Package Management:: Package installation, upgrade, etc.
118 * Programming Interface:: Using Guix in Scheme.
119 * Utilities:: Package management commands.
120 * GNU Distribution:: Software for your friendly GNU system.
121 * Contributing:: Your help needed!
123 * Acknowledgments:: Thanks!
124 * GNU Free Documentation License:: The license of this manual.
125 * Concept Index:: Concepts.
126 * Programming Index:: Data types, functions, and variables.
129 --- The Detailed Node Listing ---
133 * Binary Installation:: Getting Guix running in no time!
134 * Requirements:: Software needed to build and run Guix.
135 * Running the Test Suite:: Testing Guix.
136 * Setting Up the Daemon:: Preparing the build daemon's environment.
137 * Invoking guix-daemon:: Running the build daemon.
138 * Application Setup:: Application-specific setup.
140 Setting Up the Daemon
142 * Build Environment Setup:: Preparing the isolated build environment.
143 * Daemon Offload Setup:: Offloading builds to remote machines.
144 * SELinux Support:: Using an SELinux policy for the daemon.
148 * Features:: How Guix will make your life brighter.
149 * Invoking guix package:: Package installation, removal, etc.
150 * Substitutes:: Downloading pre-built binaries.
151 * Packages with Multiple Outputs:: Single source package, multiple outputs.
152 * Invoking guix gc:: Running the garbage collector.
153 * Invoking guix pull:: Fetching the latest Guix and distribution.
154 * Channels:: Customizing the package collection.
155 * Inferiors:: Interacting with another revision of Guix.
156 * Invoking guix describe:: Display information about your Guix revision.
157 * Invoking guix pack:: Creating software bundles.
158 * Invoking guix archive:: Exporting and importing store files.
162 * Official Substitute Server:: One particular source of substitutes.
163 * Substitute Server Authorization:: How to enable or disable substitutes.
164 * Substitute Authentication:: How Guix verifies substitutes.
165 * Proxy Settings:: How to get substitutes via proxy.
166 * Substitution Failure:: What happens when substitution fails.
167 * On Trusting Binaries:: How can you trust that binary blob?
169 Programming Interface
171 * Defining Packages:: Defining new packages.
172 * Build Systems:: Specifying how packages are built.
173 * The Store:: Manipulating the package store.
174 * Derivations:: Low-level interface to package derivations.
175 * The Store Monad:: Purely functional interface to the store.
176 * G-Expressions:: Manipulating build expressions.
177 * Invoking guix repl:: Fiddling with Guix interactively.
181 * package Reference:: The package data type.
182 * origin Reference:: The origin data type.
186 * Invoking guix build:: Building packages from the command line.
187 * Invoking guix edit:: Editing package definitions.
188 * Invoking guix download:: Downloading a file and printing its hash.
189 * Invoking guix hash:: Computing the cryptographic hash of a file.
190 * Invoking guix import:: Importing package definitions.
191 * Invoking guix refresh:: Updating package definitions.
192 * Invoking guix lint:: Finding errors in package definitions.
193 * Invoking guix size:: Profiling disk usage.
194 * Invoking guix graph:: Visualizing the graph of packages.
195 * Invoking guix environment:: Setting up development environments.
196 * Invoking guix publish:: Sharing substitutes.
197 * Invoking guix challenge:: Challenging substitute servers.
198 * Invoking guix copy:: Copying to and from a remote store.
199 * Invoking guix container:: Process isolation.
200 * Invoking guix weather:: Assessing substitute availability.
201 * Invoking guix processes:: Listing client processes.
203 Invoking @command{guix build}
205 * Common Build Options:: Build options for most commands.
206 * Package Transformation Options:: Creating variants of packages.
207 * Additional Build Options:: Options specific to 'guix build'.
208 * Debugging Build Failures:: Real life packaging experience.
212 * System Installation:: Installing the whole operating system.
213 * System Configuration:: Configuring the operating system.
214 * Documentation:: Browsing software user manuals.
215 * Installing Debugging Files:: Feeding the debugger.
216 * Security Updates:: Deploying security fixes quickly.
217 * Package Modules:: Packages from the programmer's viewpoint.
218 * Packaging Guidelines:: Growing the distribution.
219 * Bootstrapping:: GNU/Linux built from scratch.
220 * Porting:: Targeting another platform or kernel.
224 * Limitations:: What you can expect.
225 * Hardware Considerations:: Supported hardware.
226 * USB Stick and DVD Installation:: Preparing the installation medium.
227 * Preparing for Installation:: Networking, partitioning, etc.
228 * Proceeding with the Installation:: The real thing.
229 * Installing GuixSD in a VM:: GuixSD playground.
230 * Building the Installation Image:: How this comes to be.
234 * Using the Configuration System:: Customizing your GNU system.
235 * operating-system Reference:: Detail of operating-system declarations.
236 * File Systems:: Configuring file system mounts.
237 * Mapped Devices:: Block device extra processing.
238 * User Accounts:: Specifying user accounts.
239 * Locales:: Language and cultural convention settings.
240 * Services:: Specifying system services.
241 * Setuid Programs:: Programs running with root privileges.
242 * X.509 Certificates:: Authenticating HTTPS servers.
243 * Name Service Switch:: Configuring libc's name service switch.
244 * Initial RAM Disk:: Linux-Libre bootstrapping.
245 * Bootloader Configuration:: Configuring the boot loader.
246 * Invoking guix system:: Instantiating a system configuration.
247 * Running GuixSD in a VM:: How to run GuixSD in a virtual machine.
248 * Defining Services:: Adding new service definitions.
252 * Base Services:: Essential system services.
253 * Scheduled Job Execution:: The mcron service.
254 * Log Rotation:: The rottlog service.
255 * Networking Services:: Network setup, SSH daemon, etc.
256 * X Window:: Graphical display.
257 * Printing Services:: Local and remote printer support.
258 * Desktop Services:: D-Bus and desktop services.
259 * Sound Services:: ALSA and Pulseaudio services.
260 * Database Services:: SQL databases, key-value stores, etc.
261 * Mail Services:: IMAP, POP3, SMTP, and all that.
262 * Messaging Services:: Messaging services.
263 * Telephony Services:: Telephony services.
264 * Monitoring Services:: Monitoring services.
265 * Kerberos Services:: Kerberos services.
266 * Web Services:: Web servers.
267 * Certificate Services:: TLS certificates via Let's Encrypt.
268 * DNS Services:: DNS daemons.
269 * VPN Services:: VPN daemons.
270 * Network File System:: NFS related services.
271 * Continuous Integration:: The Cuirass service.
272 * Power Management Services:: Extending battery life.
273 * Audio Services:: The MPD.
274 * Virtualization Services:: Virtualization services.
275 * Version Control Services:: Providing remote access to Git repositories.
276 * Game Services:: Game servers.
277 * Miscellaneous Services:: Other services.
281 * Service Composition:: The model for composing services.
282 * Service Types and Services:: Types and services.
283 * Service Reference:: API reference.
284 * Shepherd Services:: A particular type of service.
288 * Software Freedom:: What may go into the distribution.
289 * Package Naming:: What's in a name?
290 * Version Numbers:: When the name is not enough.
291 * Synopses and Descriptions:: Helping users find the right package.
292 * Python Modules:: A touch of British comedy.
293 * Perl Modules:: Little pearls.
294 * Java Packages:: Coffee break.
295 * Fonts:: Fond of fonts.
299 * Building from Git:: The latest and greatest.
300 * Running Guix Before It Is Installed:: Hacker tricks.
301 * The Perfect Setup:: The right tools.
302 * Coding Style:: Hygiene of the contributor.
303 * Submitting Patches:: Share your work.
307 * Programming Paradigm:: How to compose your elements.
308 * Modules:: Where to store your code?
309 * Data Types and Pattern Matching:: Implementing data structures.
310 * Formatting Code:: Writing conventions.
315 @c *********************************************************************
317 @chapter Introduction
320 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
321 using the international phonetic alphabet (IPA).} is a package
322 management tool for the GNU system. Guix makes it easy for unprivileged
323 users to install, upgrade, or remove packages, to roll back to a
324 previous package set, to build packages from source, and generally
325 assists with the creation and maintenance of software environments.
327 @cindex user interfaces
328 Guix provides a command-line package management interface
329 (@pxref{Invoking guix package}), a set of command-line utilities
330 (@pxref{Utilities}), as well as Scheme programming interfaces
331 (@pxref{Programming Interface}).
333 Its @dfn{build daemon} is responsible for building packages on behalf of
334 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
335 binaries from authorized sources (@pxref{Substitutes}).
337 @cindex extensibility of the distribution
338 @cindex customization, of packages
339 Guix includes package definitions for many GNU and non-GNU packages, all
340 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
341 user's computing freedom}. It is @emph{extensible}: users can write
342 their own package definitions (@pxref{Defining Packages}) and make them
343 available as independent package modules (@pxref{Package Modules}). It
344 is also @emph{customizable}: users can @emph{derive} specialized package
345 definitions from existing ones, including from the command line
346 (@pxref{Package Transformation Options}).
348 @cindex Guix System Distribution
350 You can install GNU@tie{}Guix on top of an existing GNU/Linux system
351 where it complements the available tools without interference
352 (@pxref{Installation}), or you can use it as part of the standalone
353 @dfn{Guix System Distribution} or GuixSD (@pxref{GNU Distribution}).
354 With GNU@tie{}GuixSD, you @emph{declare} all aspects of the operating
355 system configuration and Guix takes care of instantiating the
356 configuration in a transactional, reproducible, and stateless fashion
357 (@pxref{System Configuration}).
359 @cindex functional package management
361 Under the hood, Guix implements the @dfn{functional package management}
362 discipline pioneered by Nix (@pxref{Acknowledgments}).
363 In Guix, the package build and installation process is seen
364 as a @emph{function}, in the mathematical sense. That function takes inputs,
365 such as build scripts, a compiler, and libraries, and
366 returns an installed package. As a pure function, its result depends
367 solely on its inputs---for instance, it cannot refer to software or
368 scripts that were not explicitly passed as inputs. A build function
369 always produces the same result when passed a given set of inputs. It
370 cannot alter the environment of the running system in
371 any way; for instance, it cannot create, modify, or delete files outside
372 of its build and installation directories. This is achieved by running
373 build processes in isolated environments (or @dfn{containers}), where only their
374 explicit inputs are visible.
377 The result of package build functions is @dfn{cached} in the file
378 system, in a special directory called @dfn{the store} (@pxref{The
379 Store}). Each package is installed in a directory of its own in the
380 store---by default under @file{/gnu/store}. The directory name contains
381 a hash of all the inputs used to build that package; thus, changing an
382 input yields a different directory name.
384 This approach is the foundation for the salient features of Guix: support
385 for transactional package upgrade and rollback, per-user installation, and
386 garbage collection of packages (@pxref{Features}).
389 @c *********************************************************************
391 @chapter Installation
393 @cindex installing Guix
394 @cindex official website
395 GNU Guix is available for download from its website at
396 @url{http://www.gnu.org/software/guix/}. This section describes the
397 software requirements of Guix, as well as how to install it and get
400 Note that this section is concerned with the installation of the package
401 manager, which can be done on top of a running GNU/Linux system. If,
402 instead, you want to install the complete GNU operating system,
403 @pxref{System Installation}.
405 @cindex foreign distro
406 @cindex directories related to foreign distro
408 When installed on a running GNU/Linux system---thereafter called a
409 @dfn{foreign distro}---GNU@tie{}Guix complements the available tools
410 without interference. Its data lives exclusively in two directories,
411 usually @file{/gnu/store} and @file{/var/guix}; other files on your
412 system, such as @file{/etc}, are left untouched.
414 Once installed, Guix can be updated by running @command{guix pull}
415 (@pxref{Invoking guix pull}).
418 * Binary Installation:: Getting Guix running in no time!
419 * Requirements:: Software needed to build and run Guix.
420 * Running the Test Suite:: Testing Guix.
421 * Setting Up the Daemon:: Preparing the build daemon's environment.
422 * Invoking guix-daemon:: Running the build daemon.
423 * Application Setup:: Application-specific setup.
426 @node Binary Installation
427 @section Binary Installation
429 @cindex installing Guix from binaries
430 @cindex installer script
431 This section describes how to install Guix on an arbitrary system from a
432 self-contained tarball providing binaries for Guix and for all its
433 dependencies. This is often quicker than installing from source, which
434 is described in the next sections. The only requirement is to have
438 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
439 shell installer script}, which automates the download, installation, and
440 initial configuration of Guix. It should be run as the root user.
442 Installing goes along these lines:
446 @cindex downloading Guix binary
447 Download the binary tarball from
448 @indicateurl{https://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz},
449 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
450 already running the kernel Linux, and so on.
452 @c The following is somewhat duplicated in ``System Installation''.
453 Make sure to download the associated @file{.sig} file and to verify the
454 authenticity of the tarball against it, along these lines:
457 $ wget https://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
458 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
461 If that command fails because you do not have the required public key,
462 then run this command to import it:
465 $ gpg --keyserver @value{KEY-SERVER} \
466 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
470 and rerun the @code{gpg --verify} command.
471 @c end authentication part
474 Now, you need to become the @code{root} user. Depending on your distribution,
475 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
479 # tar --warning=no-timestamp -xf \
480 guix-binary-@value{VERSION}.@var{system}.tar.xz
481 # mv var/guix /var/ && mv gnu /
484 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
485 The latter contains a ready-to-use profile for @code{root} (see next
488 Do @emph{not} unpack the tarball on a working Guix system since that
489 would overwrite its own essential files.
491 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
492 not emit warnings about ``implausibly old time stamps'' (such
493 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
495 They stem from the fact that all the
496 files in the archive have their modification time set to zero (which
497 means January 1st, 1970.) This is done on purpose to make sure the
498 archive content is independent of its creation time, thus making it
502 Make the profile available under @file{~root/.config/guix/current}, which is
503 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
506 # mkdir -p ~root/.config/guix
507 # ln -sf /var/guix/profiles/per-user/root/current-guix \
508 ~root/.config/guix/current
511 Source @file{etc/profile} to augment @code{PATH} and other relevant
512 environment variables:
515 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
516 source $GUIX_PROFILE/etc/profile
520 Create the group and user accounts for build users as explained below
521 (@pxref{Build Environment Setup}).
524 Run the daemon, and set it to automatically start on boot.
526 If your host distro uses the systemd init system, this can be achieved
529 @c Versions of systemd that supported symlinked service files are not
530 @c yet widely deployed, so we should suggest that users copy the service
533 @c See this thread for more information:
534 @c http://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
537 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
539 # systemctl start guix-daemon && systemctl enable guix-daemon
542 If your host distro uses the Upstart init system:
545 # initctl reload-configuration
546 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
551 Otherwise, you can still start the daemon manually with:
554 # ~root/.config/guix/current/bin/guix-daemon \
555 --build-users-group=guixbuild
559 Make the @command{guix} command available to other users on the machine,
563 # mkdir -p /usr/local/bin
565 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
568 It is also a good idea to make the Info version of this manual available
572 # mkdir -p /usr/local/share/info
573 # cd /usr/local/share/info
574 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
578 That way, assuming @file{/usr/local/share/info} is in the search path,
579 running @command{info guix} will open this manual (@pxref{Other Info
580 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
584 @cindex substitutes, authorization thereof
585 To use substitutes from @code{hydra.gnu.org} or one of its mirrors
586 (@pxref{Substitutes}), authorize them:
589 # guix archive --authorize < \
590 ~root/.config/guix/current/share/guix/hydra.gnu.org.pub
594 Each user may need to perform a few additional steps to make their Guix
595 environment ready for use, @pxref{Application Setup}.
598 Voilà, the installation is complete!
600 You can confirm that Guix is working by installing a sample package into
604 # guix package -i hello
607 The @code{guix} package must remain available in @code{root}'s profile,
608 or it would become subject to garbage collection---in which case you
609 would find yourself badly handicapped by the lack of the @command{guix}
610 command. In other words, do not remove @code{guix} by running
611 @code{guix package -r guix}.
613 The binary installation tarball can be (re)produced and verified simply
614 by running the following command in the Guix source tree:
617 make guix-binary.@var{system}.tar.xz
621 ... which, in turn, runs:
624 guix pack -s @var{system} --localstatedir \
625 --profile-name=current-guix guix
628 @xref{Invoking guix pack}, for more info on this handy tool.
631 @section Requirements
633 This section lists requirements when building Guix from source. The
634 build procedure for Guix is the same as for other GNU software, and is
635 not covered here. Please see the files @file{README} and @file{INSTALL}
636 in the Guix source tree for additional details.
638 GNU Guix depends on the following packages:
641 @item @url{http://gnu.org/software/guile/, GNU Guile}, version 2.0.13 or
642 later, including 2.2.x;
643 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
646 @uref{http://gnutls.org/, GnuTLS}, specifically its Guile bindings
647 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
648 Guile,, gnutls-guile, GnuTLS-Guile});
650 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
653 @c FIXME: Specify a version number once a release has been made.
654 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
656 @item @url{http://zlib.net, zlib};
657 @item @url{http://www.gnu.org/software/make/, GNU Make}.
660 The following dependencies are optional:
665 @url{http://savannah.nongnu.org/projects/guile-json/, Guile-JSON} will
666 allow you to use the @command{guix import pypi} command (@pxref{Invoking
667 guix import}). It is of
668 interest primarily for developers and not for casual users.
671 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
672 Support for build offloading (@pxref{Daemon Offload Setup}) and
673 @command{guix copy} (@pxref{Invoking guix copy}) depends on
674 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
675 version 0.10.2 or later.
678 When @url{http://www.bzip.org, libbz2} is available,
679 @command{guix-daemon} can use it to compress build logs.
682 Unless @code{--disable-daemon} was passed to @command{configure}, the
683 following packages are also needed:
686 @item @url{http://gnupg.org/, GNU libgcrypt};
687 @item @url{http://sqlite.org, SQLite 3};
688 @item @url{http://gcc.gnu.org, GCC's g++}, with support for the
692 @cindex state directory
693 When configuring Guix on a system that already has a Guix installation,
694 be sure to specify the same state directory as the existing installation
695 using the @code{--localstatedir} option of the @command{configure}
696 script (@pxref{Directory Variables, @code{localstatedir},, standards,
697 GNU Coding Standards}). The @command{configure} script protects against
698 unintended misconfiguration of @var{localstatedir} so you do not
699 inadvertently corrupt your store (@pxref{The Store}).
701 @cindex Nix, compatibility
702 When a working installation of @url{http://nixos.org/nix/, the Nix package
703 manager} is available, you
704 can instead configure Guix with @code{--disable-daemon}. In that case,
705 Nix replaces the three dependencies above.
707 Guix is compatible with Nix, so it is possible to share the same store
708 between both. To do so, you must pass @command{configure} not only the
709 same @code{--with-store-dir} value, but also the same
710 @code{--localstatedir} value. The latter is essential because it
711 specifies where the database that stores metadata about the store is
712 located, among other things. The default values for Nix are
713 @code{--with-store-dir=/nix/store} and @code{--localstatedir=/nix/var}.
714 Note that @code{--disable-daemon} is not required if
715 your goal is to share the store with Nix.
717 @node Running the Test Suite
718 @section Running the Test Suite
721 After a successful @command{configure} and @code{make} run, it is a good
722 idea to run the test suite. It can help catch issues with the setup or
723 environment, or bugs in Guix itself---and really, reporting test
724 failures is a good way to help improve the software. To run the test
731 Test cases can run in parallel: you can use the @code{-j} option of
732 GNU@tie{}make to speed things up. The first run may take a few minutes
733 on a recent machine; subsequent runs will be faster because the store
734 that is created for test purposes will already have various things in
737 It is also possible to run a subset of the tests by defining the
738 @code{TESTS} makefile variable as in this example:
741 make check TESTS="tests/store.scm tests/cpio.scm"
744 By default, tests results are displayed at a file level. In order to
745 see the details of every individual test cases, it is possible to define
746 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
749 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
752 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
753 @file{test-suite.log} file. Please specify the Guix version being used
754 as well as version numbers of the dependencies (@pxref{Requirements}) in
757 Guix also comes with a whole-system test suite that tests complete
758 GuixSD operating system instances. It can only run on systems where
759 Guix is already installed, using:
766 or, again, by defining @code{TESTS} to select a subset of tests to run:
769 make check-system TESTS="basic mcron"
772 These system tests are defined in the @code{(gnu tests @dots{})}
773 modules. They work by running the operating systems under test with
774 lightweight instrumentation in a virtual machine (VM). They can be
775 computationally intensive or rather cheap, depending on whether
776 substitutes are available for their dependencies (@pxref{Substitutes}).
777 Some of them require a lot of storage space to hold VM images.
779 Again in case of test failures, please send @email{bug-guix@@gnu.org}
782 @node Setting Up the Daemon
783 @section Setting Up the Daemon
786 Operations such as building a package or running the garbage collector
787 are all performed by a specialized process, the @dfn{build daemon}, on
788 behalf of clients. Only the daemon may access the store and its
789 associated database. Thus, any operation that manipulates the store
790 goes through the daemon. For instance, command-line tools such as
791 @command{guix package} and @command{guix build} communicate with the
792 daemon (@i{via} remote procedure calls) to instruct it what to do.
794 The following sections explain how to prepare the build daemon's
795 environment. See also @ref{Substitutes}, for information on how to allow
796 the daemon to download pre-built binaries.
799 * Build Environment Setup:: Preparing the isolated build environment.
800 * Daemon Offload Setup:: Offloading builds to remote machines.
801 * SELinux Support:: Using an SELinux policy for the daemon.
804 @node Build Environment Setup
805 @subsection Build Environment Setup
807 @cindex build environment
808 In a standard multi-user setup, Guix and its daemon---the
809 @command{guix-daemon} program---are installed by the system
810 administrator; @file{/gnu/store} is owned by @code{root} and
811 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
812 Guix tools to build packages or otherwise access the store, and the
813 daemon will do it on their behalf, ensuring that the store is kept in a
814 consistent state, and allowing built packages to be shared among users.
817 When @command{guix-daemon} runs as @code{root}, you may not want package
818 build processes themselves to run as @code{root} too, for obvious
819 security reasons. To avoid that, a special pool of @dfn{build users}
820 should be created for use by build processes started by the daemon.
821 These build users need not have a shell and a home directory: they will
822 just be used when the daemon drops @code{root} privileges in build
823 processes. Having several such users allows the daemon to launch
824 distinct build processes under separate UIDs, which guarantees that they
825 do not interfere with each other---an essential feature since builds are
826 regarded as pure functions (@pxref{Introduction}).
828 On a GNU/Linux system, a build user pool may be created like this (using
829 Bash syntax and the @code{shadow} commands):
831 @c See http://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
832 @c for why `-G' is needed.
834 # groupadd --system guixbuild
835 # for i in `seq -w 1 10`;
837 useradd -g guixbuild -G guixbuild \
838 -d /var/empty -s `which nologin` \
839 -c "Guix build user $i" --system \
845 The number of build users determines how many build jobs may run in
846 parallel, as specified by the @option{--max-jobs} option
847 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
848 @command{guix system vm} and related commands, you may need to add the
849 build users to the @code{kvm} group so they can access @file{/dev/kvm},
850 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
851 (@pxref{Invoking guix system}).
853 The @code{guix-daemon} program may then be run as @code{root} with the
854 following command@footnote{If your machine uses the systemd init system,
855 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
856 file in @file{/etc/systemd/system} will ensure that
857 @command{guix-daemon} is automatically started. Similarly, if your
858 machine uses the Upstart init system, drop the
859 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
860 file in @file{/etc/init}.}:
863 # guix-daemon --build-users-group=guixbuild
868 This way, the daemon starts build processes in a chroot, under one of
869 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
870 environment contains nothing but:
872 @c Keep this list in sync with libstore/build.cc! -----------------------
875 a minimal @code{/dev} directory, created mostly independently from the
876 host @code{/dev}@footnote{``Mostly'', because while the set of files
877 that appear in the chroot's @code{/dev} is fixed, most of these files
878 can only be created if the host has them.};
881 the @code{/proc} directory; it only shows the processes of the container
882 since a separate PID name space is used;
885 @file{/etc/passwd} with an entry for the current user and an entry for
889 @file{/etc/group} with an entry for the user's group;
892 @file{/etc/hosts} with an entry that maps @code{localhost} to
896 a writable @file{/tmp} directory.
899 You can influence the directory where the daemon stores build trees
900 @i{via} the @code{TMPDIR} environment variable. However, the build tree
901 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
902 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
903 This way, the value of @code{TMPDIR} does not leak inside build
904 environments, which avoids discrepancies in cases where build processes
905 capture the name of their build tree.
908 The daemon also honors the @code{http_proxy} environment variable for
909 HTTP downloads it performs, be it for fixed-output derivations
910 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
912 If you are installing Guix as an unprivileged user, it is still possible
913 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
914 However, build processes will not be isolated from one another, and not
915 from the rest of the system. Thus, build processes may interfere with
916 each other, and may access programs, libraries, and other files
917 available on the system---making it much harder to view them as
918 @emph{pure} functions.
921 @node Daemon Offload Setup
922 @subsection Using the Offload Facility
926 When desired, the build daemon can @dfn{offload} derivation builds to
927 other machines running Guix, using the @code{offload} @dfn{build
928 hook}@footnote{This feature is available only when
929 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
931 feature is enabled, a list of user-specified build machines is read from
932 @file{/etc/guix/machines.scm}; every time a build is requested, for
933 instance via @code{guix build}, the daemon attempts to offload it to one
934 of the machines that satisfy the constraints of the derivation, in
935 particular its system type---e.g., @file{x86_64-linux}. Missing
936 prerequisites for the build are copied over SSH to the target machine,
937 which then proceeds with the build; upon success the output(s) of the
938 build are copied back to the initial machine.
940 The @file{/etc/guix/machines.scm} file typically looks like this:
944 (name "eightysix.example.org")
945 (system "x86_64-linux")
946 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
948 (speed 2.)) ;incredibly fast!
951 (name "meeps.example.org")
952 (system "mips64el-linux")
953 (host-key "ssh-rsa AAAAB3Nza@dots{}")
956 (string-append (getenv "HOME")
957 "/.ssh/identity-for-guix"))))
961 In the example above we specify a list of two build machines, one for
962 the @code{x86_64} architecture and one for the @code{mips64el}
965 In fact, this file is---not surprisingly!---a Scheme file that is
966 evaluated when the @code{offload} hook is started. Its return value
967 must be a list of @code{build-machine} objects. While this example
968 shows a fixed list of build machines, one could imagine, say, using
969 DNS-SD to return a list of potential build machines discovered in the
970 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
971 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
974 @deftp {Data Type} build-machine
975 This data type represents build machines to which the daemon may offload
976 builds. The important fields are:
981 The host name of the remote machine.
984 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
987 The user account to use when connecting to the remote machine over SSH.
988 Note that the SSH key pair must @emph{not} be passphrase-protected, to
989 allow non-interactive logins.
992 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
993 This is used to authenticate the machine when we connect to it. It is a
994 long string that looks like this:
997 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1000 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1001 key can be found in a file such as
1002 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1004 If the machine is running the SSH daemon of GNU@tie{}lsh,
1005 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1006 similar file. It can be converted to the OpenSSH format using
1007 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1010 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1011 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1016 A number of optional fields may be specified:
1020 @item @code{port} (default: @code{22})
1021 Port number of SSH server on the machine.
1023 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1024 The SSH private key file to use when connecting to the machine, in
1025 OpenSSH format. This key must not be protected with a passphrase.
1027 Note that the default value is the private key @emph{of the root
1028 account}. Make sure it exists if you use the default.
1030 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1031 @itemx @code{compression-level} (default: @code{3})
1032 The SSH-level compression methods and compression level requested.
1034 Note that offloading relies on SSH compression to reduce bandwidth usage
1035 when transferring files to and from build machines.
1037 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1038 File name of the Unix-domain socket @command{guix-daemon} is listening
1041 @item @code{parallel-builds} (default: @code{1})
1042 The number of builds that may run in parallel on the machine.
1044 @item @code{speed} (default: @code{1.0})
1045 A ``relative speed factor''. The offload scheduler will tend to prefer
1046 machines with a higher speed factor.
1048 @item @code{features} (default: @code{'()})
1049 A list of strings denoting specific features supported by the machine.
1050 An example is @code{"kvm"} for machines that have the KVM Linux modules
1051 and corresponding hardware support. Derivations can request features by
1052 name, and they will be scheduled on matching build machines.
1057 The @code{guile} command must be in the search path on the build
1058 machines. In addition, the Guix modules must be in
1059 @code{$GUILE_LOAD_PATH} on the build machine---you can check whether
1060 this is the case by running:
1063 ssh build-machine guile -c "'(use-modules (guix config))'"
1066 There is one last thing to do once @file{machines.scm} is in place. As
1067 explained above, when offloading, files are transferred back and forth
1068 between the machine stores. For this to work, you first need to
1069 generate a key pair on each machine to allow the daemon to export signed
1070 archives of files from the store (@pxref{Invoking guix archive}):
1073 # guix archive --generate-key
1077 Each build machine must authorize the key of the master machine so that
1078 it accepts store items it receives from the master:
1081 # guix archive --authorize < master-public-key.txt
1085 Likewise, the master machine must authorize the key of each build machine.
1087 All the fuss with keys is here to express pairwise mutual trust
1088 relations between the master and the build machines. Concretely, when
1089 the master receives files from a build machine (and @i{vice versa}), its
1090 build daemon can make sure they are genuine, have not been tampered
1091 with, and that they are signed by an authorized key.
1093 @cindex offload test
1094 To test whether your setup is operational, run this command on the
1101 This will attempt to connect to each of the build machines specified in
1102 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1103 available on each machine, attempt to export to the machine and import
1104 from it, and report any error in the process.
1106 If you want to test a different machine file, just specify it on the
1110 # guix offload test machines-qualif.scm
1113 Last, you can test the subset of the machines whose name matches a
1114 regular expression like this:
1117 # guix offload test machines.scm '\.gnu\.org$'
1120 @cindex offload status
1121 To display the current load of all build hosts, run this command on the
1125 # guix offload status
1129 @node SELinux Support
1130 @subsection SELinux Support
1132 @cindex SELinux, daemon policy
1133 @cindex mandatory access control, SELinux
1134 @cindex security, guix-daemon
1135 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1136 can be installed on a system where SELinux is enabled, in order to label
1137 Guix files and to specify the expected behavior of the daemon. Since
1138 GuixSD does not provide an SELinux base policy, the daemon policy cannot
1141 @subsubsection Installing the SELinux policy
1142 @cindex SELinux, policy installation
1143 To install the policy run this command as root:
1146 semodule -i etc/guix-daemon.cil
1149 Then relabel the file system with @code{restorecon} or by a different
1150 mechanism provided by your system.
1152 Once the policy is installed, the file system has been relabeled, and
1153 the daemon has been restarted, it should be running in the
1154 @code{guix_daemon_t} context. You can confirm this with the following
1158 ps -Zax | grep guix-daemon
1161 Monitor the SELinux log files as you run a command like @code{guix build
1162 hello} to convince yourself that SELinux permits all necessary
1165 @subsubsection Limitations
1166 @cindex SELinux, limitations
1168 This policy is not perfect. Here is a list of limitations or quirks
1169 that should be considered when deploying the provided SELinux policy for
1174 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1175 operations involve contexts that have anything to do with
1176 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1177 but it would be preferrable to define socket rules for only this label.
1180 @code{guix gc} cannot access arbitrary links to profiles. By design,
1181 the file label of the destination of a symlink is independent of the
1182 file label of the link itself. Although all profiles under
1183 $localstatedir are labelled, the links to these profiles inherit the
1184 label of the directory they are in. For links in the user’s home
1185 directory this will be @code{user_home_t}. But for links from the root
1186 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1187 directory, etc, this won’t work. @code{guix gc} would be prevented from
1188 reading and following these links.
1191 The daemon’s feature to listen for TCP connections might no longer work.
1192 This might require extra rules, because SELinux treats network sockets
1193 differently from files.
1196 Currently all files with a name matching the regular expression
1197 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1198 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1199 that name in any profile would be permitted to run in the
1200 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1201 build a package that provides this executable and convince a user to
1202 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1203 At that point SELinux could not prevent it from accessing files that are
1204 allowed for processes in that domain.
1206 We could generate a much more restrictive policy at installation time,
1207 so that only the @emph{exact} file name of the currently installed
1208 @code{guix-daemon} executable would be labelled with
1209 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1210 The downside is that root would have to install or upgrade the policy at
1211 installation time whenever the Guix package that provides the
1212 effectively running @code{guix-daemon} executable is upgraded.
1215 @node Invoking guix-daemon
1216 @section Invoking @command{guix-daemon}
1218 The @command{guix-daemon} program implements all the functionality to
1219 access the store. This includes launching build processes, running the
1220 garbage collector, querying the availability of a build result, etc. It
1221 is normally run as @code{root} like this:
1224 # guix-daemon --build-users-group=guixbuild
1228 For details on how to set it up, @pxref{Setting Up the Daemon}.
1231 @cindex container, build environment
1232 @cindex build environment
1233 @cindex reproducible builds
1234 By default, @command{guix-daemon} launches build processes under
1235 different UIDs, taken from the build group specified with
1236 @code{--build-users-group}. In addition, each build process is run in a
1237 chroot environment that only contains the subset of the store that the
1238 build process depends on, as specified by its derivation
1239 (@pxref{Programming Interface, derivation}), plus a set of specific
1240 system directories. By default, the latter contains @file{/dev} and
1241 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1242 @dfn{container}: in addition to having its own file system tree, it has
1243 a separate mount name space, its own PID name space, network name space,
1244 etc. This helps achieve reproducible builds (@pxref{Features}).
1246 When the daemon performs a build on behalf of the user, it creates a
1247 build directory under @file{/tmp} or under the directory specified by
1248 its @code{TMPDIR} environment variable. This directory is shared with
1249 the container for the duration of the build, though within the container,
1250 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1252 The build directory is automatically deleted upon completion, unless the
1253 build failed and the client specified @option{--keep-failed}
1254 (@pxref{Invoking guix build, @option{--keep-failed}}).
1256 The daemon listens for connections and spawns one sub-process for each session
1257 started by a client (one of the @command{guix} sub-commands.) The
1258 @command{guix processes} command allows you to get an overview of the activity
1259 on your system by viewing each of the active sessions and clients.
1260 @xref{Invoking guix processes}, for more information.
1262 The following command-line options are supported:
1265 @item --build-users-group=@var{group}
1266 Take users from @var{group} to run build processes (@pxref{Setting Up
1267 the Daemon, build users}).
1269 @item --no-substitutes
1271 Do not use substitutes for build products. That is, always build things
1272 locally instead of allowing downloads of pre-built binaries
1273 (@pxref{Substitutes}).
1275 When the daemon runs with @code{--no-substitutes}, clients can still
1276 explicitly enable substitution @i{via} the @code{set-build-options}
1277 remote procedure call (@pxref{The Store}).
1279 @item --substitute-urls=@var{urls}
1280 @anchor{daemon-substitute-urls}
1281 Consider @var{urls} the default whitespace-separated list of substitute
1282 source URLs. When this option is omitted,
1283 @indicateurl{https://mirror.hydra.gnu.org https://hydra.gnu.org} is used
1284 (@code{mirror.hydra.gnu.org} is a mirror of @code{hydra.gnu.org}).
1286 This means that substitutes may be downloaded from @var{urls}, as long
1287 as they are signed by a trusted signature (@pxref{Substitutes}).
1290 @item --no-build-hook
1291 Do not use the @dfn{build hook}.
1293 The build hook is a helper program that the daemon can start and to
1294 which it submits build requests. This mechanism is used to offload
1295 builds to other machines (@pxref{Daemon Offload Setup}).
1297 @item --cache-failures
1298 Cache build failures. By default, only successful builds are cached.
1300 When this option is used, @command{guix gc --list-failures} can be used
1301 to query the set of store items marked as failed; @command{guix gc
1302 --clear-failures} removes store items from the set of cached failures.
1303 @xref{Invoking guix gc}.
1305 @item --cores=@var{n}
1307 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1310 The default value is @code{0}, but it may be overridden by clients, such
1311 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1314 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1315 in the build process, which can then use it to exploit internal
1316 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1318 @item --max-jobs=@var{n}
1320 Allow at most @var{n} build jobs in parallel. The default value is
1321 @code{1}. Setting it to @code{0} means that no builds will be performed
1322 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1323 Setup}), or simply fail.
1325 @item --max-silent-time=@var{seconds}
1326 When the build or substitution process remains silent for more than
1327 @var{seconds}, terminate it and report a build failure.
1329 The default value is @code{0}, which disables the timeout.
1331 The value specified here can be overridden by clients (@pxref{Common
1332 Build Options, @code{--max-silent-time}}).
1334 @item --timeout=@var{seconds}
1335 Likewise, when the build or substitution process lasts for more than
1336 @var{seconds}, terminate it and report a build failure.
1338 The default value is @code{0}, which disables the timeout.
1340 The value specified here can be overridden by clients (@pxref{Common
1341 Build Options, @code{--timeout}}).
1343 @item --rounds=@var{N}
1344 Build each derivation @var{n} times in a row, and raise an error if
1345 consecutive build results are not bit-for-bit identical. Note that this
1346 setting can be overridden by clients such as @command{guix build}
1347 (@pxref{Invoking guix build}).
1349 When used in conjunction with @option{--keep-failed}, the differing
1350 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1351 This makes it easy to look for differences between the two results.
1354 Produce debugging output.
1356 This is useful to debug daemon start-up issues, but then it may be
1357 overridden by clients, for example the @code{--verbosity} option of
1358 @command{guix build} (@pxref{Invoking guix build}).
1360 @item --chroot-directory=@var{dir}
1361 Add @var{dir} to the build chroot.
1363 Doing this may change the result of build processes---for instance if
1364 they use optional dependencies found in @var{dir} when it is available,
1365 and not otherwise. For that reason, it is not recommended to do so.
1366 Instead, make sure that each derivation declares all the inputs that it
1369 @item --disable-chroot
1370 Disable chroot builds.
1372 Using this option is not recommended since, again, it would allow build
1373 processes to gain access to undeclared dependencies. It is necessary,
1374 though, when @command{guix-daemon} is running under an unprivileged user
1377 @item --log-compression=@var{type}
1378 Compress build logs according to @var{type}, one of @code{gzip},
1379 @code{bzip2}, or @code{none}.
1381 Unless @code{--lose-logs} is used, all the build logs are kept in the
1382 @var{localstatedir}. To save space, the daemon automatically compresses
1383 them with bzip2 by default.
1385 @item --disable-deduplication
1386 @cindex deduplication
1387 Disable automatic file ``deduplication'' in the store.
1389 By default, files added to the store are automatically ``deduplicated'':
1390 if a newly added file is identical to another one found in the store,
1391 the daemon makes the new file a hard link to the other file. This can
1392 noticeably reduce disk usage, at the expense of slightly increased
1393 input/output load at the end of a build process. This option disables
1396 @item --gc-keep-outputs[=yes|no]
1397 Tell whether the garbage collector (GC) must keep outputs of live
1401 @cindex garbage collector roots
1402 When set to ``yes'', the GC will keep the outputs of any live derivation
1403 available in the store---the @code{.drv} files. The default is ``no'',
1404 meaning that derivation outputs are kept only if they are reachable from a GC
1405 root. @xref{Invoking guix gc}, for more on GC roots.
1407 @item --gc-keep-derivations[=yes|no]
1408 Tell whether the garbage collector (GC) must keep derivations
1409 corresponding to live outputs.
1411 When set to ``yes'', as is the case by default, the GC keeps
1412 derivations---i.e., @code{.drv} files---as long as at least one of their
1413 outputs is live. This allows users to keep track of the origins of
1414 items in their store. Setting it to ``no'' saves a bit of disk space.
1416 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1417 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1418 ``yes'' causes liveness to flow from derivations to outputs. When both are
1419 set to ``yes'', the effect is to keep all the build prerequisites (the
1420 sources, compiler, libraries, and other build-time tools) of live objects in
1421 the store, regardless of whether these prerequisites are reachable from a GC
1422 root. This is convenient for developers since it saves rebuilds or downloads.
1424 @item --impersonate-linux-2.6
1425 On Linux-based systems, impersonate Linux 2.6. This means that the
1426 kernel's @code{uname} system call will report 2.6 as the release number.
1428 This might be helpful to build programs that (usually wrongfully) depend
1429 on the kernel version number.
1432 Do not keep build logs. By default they are kept under
1433 @code{@var{localstatedir}/guix/log}.
1435 @item --system=@var{system}
1436 Assume @var{system} as the current system type. By default it is the
1437 architecture/kernel pair found at configure time, such as
1438 @code{x86_64-linux}.
1440 @item --listen=@var{endpoint}
1441 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1442 as the file name of a Unix-domain socket if it starts with
1443 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1444 host name or host name and port to listen to. Here are a few examples:
1447 @item --listen=/gnu/var/daemon
1448 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1449 creating it if needed.
1451 @item --listen=localhost
1452 @cindex daemon, remote access
1453 @cindex remote access to the daemon
1454 @cindex daemon, cluster setup
1455 @cindex clusters, daemon setup
1456 Listen for TCP connections on the network interface corresponding to
1457 @code{localhost}, on port 44146.
1459 @item --listen=128.0.0.42:1234
1460 Listen for TCP connections on the network interface corresponding to
1461 @code{128.0.0.42}, on port 1234.
1464 This option can be repeated multiple times, in which case
1465 @command{guix-daemon} accepts connections on all the specified
1466 endpoints. Users can tell client commands what endpoint to connect to
1467 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1468 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1471 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1472 @code{--listen=@var{host}} is suitable on local networks, such as
1473 clusters, where only trusted nodes may connect to the build daemon. In
1474 other cases where remote access to the daemon is needed, we recommend
1475 using Unix-domain sockets along with SSH.
1478 When @code{--listen} is omitted, @command{guix-daemon} listens for
1479 connections on the Unix-domain socket located at
1480 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1484 @node Application Setup
1485 @section Application Setup
1487 @cindex foreign distro
1488 When using Guix on top of GNU/Linux distribution other than GuixSD---a
1489 so-called @dfn{foreign distro}---a few additional steps are needed to
1490 get everything in place. Here are some of them.
1494 @anchor{locales-and-locpath}
1495 @cindex locales, when not on GuixSD
1497 @vindex GUIX_LOCPATH
1498 Packages installed @i{via} Guix will not use the locale data of the
1499 host system. Instead, you must first install one of the locale packages
1500 available with Guix and then define the @code{GUIX_LOCPATH} environment
1504 $ guix package -i glibc-locales
1505 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1508 Note that the @code{glibc-locales} package contains data for all the
1509 locales supported by the GNU@tie{}libc and weighs in at around
1510 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1511 limited to a few UTF-8 locales.
1513 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1514 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1515 Manual}). There are two important differences though:
1519 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1520 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1521 to make sure the programs of the foreign distro will not end up loading
1522 incompatible locale data.
1525 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1526 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1527 should your Guix profile contain a mixture of programs linked against
1528 different libc version, each libc version will only try to load locale
1529 data in the right format.
1532 This is important because the locale data format used by different libc
1533 versions may be incompatible.
1535 @subsection Name Service Switch
1537 @cindex name service switch, glibc
1538 @cindex NSS (name service switch), glibc
1539 @cindex nscd (name service caching daemon)
1540 @cindex name service caching daemon (nscd)
1541 When using Guix on a foreign distro, we @emph{strongly recommend} that
1542 the system run the GNU C library's @dfn{name service cache daemon},
1543 @command{nscd}, which should be listening on the
1544 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1545 installed with Guix may fail to look up host names or user accounts, or
1546 may even crash. The next paragraphs explain why.
1548 @cindex @file{nsswitch.conf}
1549 The GNU C library implements a @dfn{name service switch} (NSS), which is
1550 an extensible mechanism for ``name lookups'' in general: host name
1551 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1552 The GNU C Library Reference Manual}).
1554 @cindex Network information service (NIS)
1555 @cindex NIS (Network information service)
1556 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1557 lookup implementations: for example, the @code{nss-mdns} plugin allow
1558 resolution of @code{.local} host names, the @code{nis} plugin allows
1559 user account lookup using the Network information service (NIS), and so
1560 on. These extra ``lookup services'' are configured system-wide in
1561 @file{/etc/nsswitch.conf}, and all the programs running on the system
1562 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1565 When they perform a name lookup---for instance by calling the
1566 @code{getaddrinfo} function in C---applications first try to connect to
1567 the nscd; on success, nscd performs name lookups on their behalf. If
1568 the nscd is not running, then they perform the name lookup by
1569 themselves, by loading the name lookup services into their own address
1570 space and running it. These name lookup services---the
1571 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1572 the host system's C library, rather than from the C library the
1573 application is linked against (the C library coming from Guix).
1575 And this is where the problem is: if your application is linked against
1576 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1577 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1578 likely crash or have its name lookups fail unexpectedly.
1580 Running @command{nscd} on the system, among other advantages, eliminates
1581 this binary incompatibility problem because those @code{libnss_*.so}
1582 files are loaded in the @command{nscd} process, not in applications
1585 @subsection X11 Fonts
1588 The majority of graphical applications use Fontconfig to locate and
1589 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1590 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1591 by default. Thus, to allow graphical applications installed with Guix
1592 to display fonts, you have to install fonts with Guix as well.
1593 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1594 @code{font-gnu-freefont-ttf}.
1596 To display text written in Chinese languages, Japanese, or Korean in
1597 graphical applications, consider installing
1598 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1599 has multiple outputs, one per language family (@pxref{Packages with
1600 Multiple Outputs}). For instance, the following command installs fonts
1601 for Chinese languages:
1604 guix package -i font-adobe-source-han-sans:cn
1607 @cindex @code{xterm}
1608 Older programs such as @command{xterm} do not use Fontconfig and instead
1609 rely on server-side font rendering. Such programs require to specify a
1610 full name of a font using XLFD (X Logical Font Description), like this:
1613 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1616 To be able to use such full names for the TrueType fonts installed in
1617 your Guix profile, you need to extend the font path of the X server:
1619 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1620 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1622 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1625 @cindex @code{xlsfonts}
1626 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1627 to make sure your TrueType fonts are listed there.
1629 @cindex @code{fc-cache}
1631 After installing fonts you may have to refresh the font cache to use
1632 them in applications. The same applies when applications installed via
1633 Guix do not seem to find fonts. To force rebuilding of the font cache
1634 run @code{fc-cache -f}. The @code{fc-cache} command is provided by the
1635 @code{fontconfig} package.
1637 @subsection X.509 Certificates
1639 @cindex @code{nss-certs}
1640 The @code{nss-certs} package provides X.509 certificates, which allow
1641 programs to authenticate Web servers accessed over HTTPS.
1643 When using Guix on a foreign distro, you can install this package and
1644 define the relevant environment variables so that packages know where to
1645 look for certificates. @xref{X.509 Certificates}, for detailed
1648 @subsection Emacs Packages
1650 @cindex @code{emacs}
1651 When you install Emacs packages with Guix, the elisp files may be placed
1652 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1654 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1655 directory exists because potentially there may exist thousands of Emacs
1656 packages and storing all their files in a single directory may not be
1657 reliable (because of name conflicts). So we think using a separate
1658 directory for each package is a good idea. It is very similar to how
1659 the Emacs package system organizes the file structure (@pxref{Package
1660 Files,,, emacs, The GNU Emacs Manual}).
1662 By default, Emacs (installed with Guix) ``knows'' where these packages
1663 are placed, so you do not need to perform any configuration. If, for
1664 some reason, you want to avoid auto-loading Emacs packages installed
1665 with Guix, you can do so by running Emacs with @code{--no-site-file}
1666 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1668 @subsection The GCC toolchain
1673 Guix offers individual compiler packages such as @code{gcc} but if you
1674 are in need of a complete toolchain for compiling and linking source
1675 code what you really want is the @code{gcc-toolchain} package. This
1676 package provides a complete GCC toolchain for C/C++ development,
1677 including GCC itself, the GNU C Library (headers and binaries, plus
1678 debugging symbols in the @code{debug} output), Binutils, and a linker
1681 @cindex attempt to use impure library, error message
1683 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1684 passed to the linker, add corresponding @code{-rpath} arguments, and
1685 invoke the actual linker with this new set of arguments. By default,
1686 the linker wrapper refuses to link to libraries outside the store to
1687 ensure ``purity''. This can be annoying when using the toolchain to
1688 link with local libraries. To allow references to libraries outside the
1689 store you need to define the environment variable
1690 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES}.
1694 @c *********************************************************************
1695 @node Package Management
1696 @chapter Package Management
1699 The purpose of GNU Guix is to allow users to easily install, upgrade, and
1700 remove software packages, without having to know about their build
1701 procedures or dependencies. Guix also goes beyond this obvious set of
1704 This chapter describes the main features of Guix, as well as the
1705 package management tools it provides. Along with the command-line
1706 interface described below (@pxref{Invoking guix package, @code{guix
1707 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
1708 emacs-guix, The Emacs-Guix Reference Manual}), after installing
1709 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
1713 guix package -i emacs-guix
1717 * Features:: How Guix will make your life brighter.
1718 * Invoking guix package:: Package installation, removal, etc.
1719 * Substitutes:: Downloading pre-built binaries.
1720 * Packages with Multiple Outputs:: Single source package, multiple outputs.
1721 * Invoking guix gc:: Running the garbage collector.
1722 * Invoking guix pull:: Fetching the latest Guix and distribution.
1723 * Channels:: Customizing the package collection.
1724 * Inferiors:: Interacting with another revision of Guix.
1725 * Invoking guix describe:: Display information about your Guix revision.
1726 * Invoking guix pack:: Creating software bundles.
1727 * Invoking guix archive:: Exporting and importing store files.
1733 When using Guix, each package ends up in the @dfn{package store}, in its
1734 own directory---something that resembles
1735 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
1737 Instead of referring to these directories, users have their own
1738 @dfn{profile}, which points to the packages that they actually want to
1739 use. These profiles are stored within each user's home directory, at
1740 @code{$HOME/.guix-profile}.
1742 For example, @code{alice} installs GCC 4.7.2. As a result,
1743 @file{/home/alice/.guix-profile/bin/gcc} points to
1744 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
1745 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
1746 simply continues to point to
1747 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
1748 coexist on the same system without any interference.
1750 The @command{guix package} command is the central tool to manage
1751 packages (@pxref{Invoking guix package}). It operates on the per-user
1752 profiles, and can be used @emph{with normal user privileges}.
1754 @cindex transactions
1755 The command provides the obvious install, remove, and upgrade
1756 operations. Each invocation is actually a @emph{transaction}: either
1757 the specified operation succeeds, or nothing happens. Thus, if the
1758 @command{guix package} process is terminated during the transaction,
1759 or if a power outage occurs during the transaction, then the user's
1760 profile remains in its previous state, and remains usable.
1762 In addition, any package transaction may be @emph{rolled back}. So, if,
1763 for example, an upgrade installs a new version of a package that turns
1764 out to have a serious bug, users may roll back to the previous instance
1765 of their profile, which was known to work well. Similarly, the global
1766 system configuration on GuixSD is subject to
1767 transactional upgrades and roll-back
1768 (@pxref{Using the Configuration System}).
1770 All packages in the package store may be @emph{garbage-collected}.
1771 Guix can determine which packages are still referenced by user
1772 profiles, and remove those that are provably no longer referenced
1773 (@pxref{Invoking guix gc}). Users may also explicitly remove old
1774 generations of their profile so that the packages they refer to can be
1777 @cindex reproducibility
1778 @cindex reproducible builds
1779 Guix takes a @dfn{purely functional} approach to package
1780 management, as described in the introduction (@pxref{Introduction}).
1781 Each @file{/gnu/store} package directory name contains a hash of all the
1782 inputs that were used to build that package---compiler, libraries, build
1783 scripts, etc. This direct correspondence allows users to make sure a
1784 given package installation matches the current state of their
1785 distribution. It also helps maximize @dfn{build reproducibility}:
1786 thanks to the isolated build environments that are used, a given build
1787 is likely to yield bit-identical files when performed on different
1788 machines (@pxref{Invoking guix-daemon, container}).
1791 This foundation allows Guix to support @dfn{transparent binary/source
1792 deployment}. When a pre-built binary for a @file{/gnu/store} item is
1793 available from an external source---a @dfn{substitute}, Guix just
1794 downloads it and unpacks it;
1795 otherwise, it builds the package from source, locally
1796 (@pxref{Substitutes}). Because build results are usually bit-for-bit
1797 reproducible, users do not have to trust servers that provide
1798 substitutes: they can force a local build and @emph{challenge} providers
1799 (@pxref{Invoking guix challenge}).
1801 Control over the build environment is a feature that is also useful for
1802 developers. The @command{guix environment} command allows developers of
1803 a package to quickly set up the right development environment for their
1804 package, without having to manually install the dependencies of the
1805 package into their profile (@pxref{Invoking guix environment}).
1807 @cindex replication, of software environments
1808 @cindex provenance tracking, of software artifacts
1809 All of Guix and its package definitions is version-controlled, and
1810 @command{guix pull} allows you to ``travel in time'' on the history of Guix
1811 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
1812 Guix instance on a different machine or at a later point in time, which in
1813 turn allows you to @emph{replicate complete software environments}, while
1814 retaining precise @dfn{provenance tracking} of the software.
1816 @node Invoking guix package
1817 @section Invoking @command{guix package}
1819 @cindex installing packages
1820 @cindex removing packages
1821 @cindex package installation
1822 @cindex package removal
1823 The @command{guix package} command is the tool that allows users to
1824 install, upgrade, and remove packages, as well as rolling back to
1825 previous configurations. It operates only on the user's own profile,
1826 and works with normal user privileges (@pxref{Features}). Its syntax
1830 guix package @var{options}
1832 @cindex transactions
1833 Primarily, @var{options} specifies the operations to be performed during
1834 the transaction. Upon completion, a new profile is created, but
1835 previous @dfn{generations} of the profile remain available, should the user
1838 For example, to remove @code{lua} and install @code{guile} and
1839 @code{guile-cairo} in a single transaction:
1842 guix package -r lua -i guile guile-cairo
1845 @command{guix package} also supports a @dfn{declarative approach}
1846 whereby the user specifies the exact set of packages to be available and
1847 passes it @i{via} the @option{--manifest} option
1848 (@pxref{profile-manifest, @option{--manifest}}).
1851 For each user, a symlink to the user's default profile is automatically
1852 created in @file{$HOME/.guix-profile}. This symlink always points to the
1853 current generation of the user's default profile. Thus, users can add
1854 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
1855 variable, and so on.
1856 @cindex search paths
1857 If you are not using the Guix System Distribution, consider adding the
1858 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
1859 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
1860 shells get all the right environment variable definitions:
1863 GUIX_PROFILE="$HOME/.guix-profile" ; \
1864 source "$HOME/.guix-profile/etc/profile"
1867 In a multi-user setup, user profiles are stored in a place registered as
1868 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
1869 to (@pxref{Invoking guix gc}). That directory is normally
1870 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
1871 @var{localstatedir} is the value passed to @code{configure} as
1872 @code{--localstatedir}, and @var{user} is the user name. The
1873 @file{per-user} directory is created when @command{guix-daemon} is
1874 started, and the @var{user} sub-directory is created by @command{guix
1877 The @var{options} can be among the following:
1881 @item --install=@var{package} @dots{}
1882 @itemx -i @var{package} @dots{}
1883 Install the specified @var{package}s.
1885 Each @var{package} may specify either a simple package name, such as
1886 @code{guile}, or a package name followed by an at-sign and version number,
1887 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
1888 case, the newest version prefixed by @code{1.8} is selected.)
1890 If no version number is specified, the
1891 newest available version will be selected. In addition, @var{package}
1892 may contain a colon, followed by the name of one of the outputs of the
1893 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
1894 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
1895 name (and optionally version) are searched for among the GNU
1896 distribution modules (@pxref{Package Modules}).
1898 @cindex propagated inputs
1899 Sometimes packages have @dfn{propagated inputs}: these are dependencies
1900 that automatically get installed along with the required package
1901 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
1902 @code{package} objects}, for information about propagated inputs in
1903 package definitions).
1905 @anchor{package-cmd-propagated-inputs}
1906 An example is the GNU MPC library: its C header files refer to those of
1907 the GNU MPFR library, which in turn refer to those of the GMP library.
1908 Thus, when installing MPC, the MPFR and GMP libraries also get installed
1909 in the profile; removing MPC also removes MPFR and GMP---unless they had
1910 also been explicitly installed by the user.
1912 Besides, packages sometimes rely on the definition of environment
1913 variables for their search paths (see explanation of
1914 @code{--search-paths} below). Any missing or possibly incorrect
1915 environment variable definitions are reported here.
1917 @item --install-from-expression=@var{exp}
1919 Install the package @var{exp} evaluates to.
1921 @var{exp} must be a Scheme expression that evaluates to a
1922 @code{<package>} object. This option is notably useful to disambiguate
1923 between same-named variants of a package, with expressions such as
1924 @code{(@@ (gnu packages base) guile-final)}.
1926 Note that this option installs the first output of the specified
1927 package, which may be insufficient when needing a specific output of a
1928 multiple-output package.
1930 @item --install-from-file=@var{file}
1931 @itemx -f @var{file}
1932 Install the package that the code within @var{file} evaluates to.
1934 As an example, @var{file} might contain a definition like this
1935 (@pxref{Defining Packages}):
1938 @verbatiminclude package-hello.scm
1941 Developers may find it useful to include such a @file{guix.scm} file
1942 in the root of their project source tree that can be used to test
1943 development snapshots and create reproducible development environments
1944 (@pxref{Invoking guix environment}).
1946 @item --remove=@var{package} @dots{}
1947 @itemx -r @var{package} @dots{}
1948 Remove the specified @var{package}s.
1950 As for @code{--install}, each @var{package} may specify a version number
1951 and/or output name in addition to the package name. For instance,
1952 @code{-r glibc:debug} would remove the @code{debug} output of
1955 @item --upgrade[=@var{regexp} @dots{}]
1956 @itemx -u [@var{regexp} @dots{}]
1957 @cindex upgrading packages
1958 Upgrade all the installed packages. If one or more @var{regexp}s are
1959 specified, upgrade only installed packages whose name matches a
1960 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
1962 Note that this upgrades package to the latest version of packages found
1963 in the distribution currently installed. To update your distribution,
1964 you should regularly run @command{guix pull} (@pxref{Invoking guix
1967 @item --do-not-upgrade[=@var{regexp} @dots{}]
1968 When used together with the @code{--upgrade} option, do @emph{not}
1969 upgrade any packages whose name matches a @var{regexp}. For example, to
1970 upgrade all packages in the current profile except those containing the
1971 substring ``emacs'':
1974 $ guix package --upgrade . --do-not-upgrade emacs
1977 @item @anchor{profile-manifest}--manifest=@var{file}
1978 @itemx -m @var{file}
1979 @cindex profile declaration
1980 @cindex profile manifest
1981 Create a new generation of the profile from the manifest object
1982 returned by the Scheme code in @var{file}.
1984 This allows you to @emph{declare} the profile's contents rather than
1985 constructing it through a sequence of @code{--install} and similar
1986 commands. The advantage is that @var{file} can be put under version
1987 control, copied to different machines to reproduce the same profile, and
1990 @c FIXME: Add reference to (guix profile) documentation when available.
1991 @var{file} must return a @dfn{manifest} object, which is roughly a list
1994 @findex packages->manifest
1996 (use-package-modules guile emacs)
2001 ;; Use a specific package output.
2002 (list guile-2.0 "debug")))
2005 @findex specifications->manifest
2006 In this example we have to know which modules define the @code{emacs}
2007 and @code{guile-2.0} variables to provide the right
2008 @code{use-package-modules} line, which can be cumbersome. We can
2009 instead provide regular package specifications and let
2010 @code{specifications->manifest} look up the corresponding package
2014 (specifications->manifest
2015 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2019 @cindex rolling back
2020 @cindex undoing transactions
2021 @cindex transactions, undoing
2022 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2023 the last transaction.
2025 When combined with options such as @code{--install}, roll back occurs
2026 before any other actions.
2028 When rolling back from the first generation that actually contains
2029 installed packages, the profile is made to point to the @dfn{zeroth
2030 generation}, which contains no files apart from its own metadata.
2032 After having rolled back, installing, removing, or upgrading packages
2033 overwrites previous future generations. Thus, the history of the
2034 generations in a profile is always linear.
2036 @item --switch-generation=@var{pattern}
2037 @itemx -S @var{pattern}
2039 Switch to a particular generation defined by @var{pattern}.
2041 @var{pattern} may be either a generation number or a number prefixed
2042 with ``+'' or ``-''. The latter means: move forward/backward by a
2043 specified number of generations. For example, if you want to return to
2044 the latest generation after @code{--roll-back}, use
2045 @code{--switch-generation=+1}.
2047 The difference between @code{--roll-back} and
2048 @code{--switch-generation=-1} is that @code{--switch-generation} will
2049 not make a zeroth generation, so if a specified generation does not
2050 exist, the current generation will not be changed.
2052 @item --search-paths[=@var{kind}]
2053 @cindex search paths
2054 Report environment variable definitions, in Bash syntax, that may be
2055 needed in order to use the set of installed packages. These environment
2056 variables are used to specify @dfn{search paths} for files used by some
2057 of the installed packages.
2059 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2060 environment variables to be defined so it can look for headers and
2061 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2062 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2063 library are installed in the profile, then @code{--search-paths} will
2064 suggest setting these variables to @code{@var{profile}/include} and
2065 @code{@var{profile}/lib}, respectively.
2067 The typical use case is to define these environment variables in the
2071 $ eval `guix package --search-paths`
2074 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2075 meaning that the returned environment variable definitions will either
2076 be exact settings, or prefixes or suffixes of the current value of these
2077 variables. When omitted, @var{kind} defaults to @code{exact}.
2079 This option can also be used to compute the @emph{combined} search paths
2080 of several profiles. Consider this example:
2083 $ guix package -p foo -i guile
2084 $ guix package -p bar -i guile-json
2085 $ guix package -p foo -p bar --search-paths
2088 The last command above reports about the @code{GUILE_LOAD_PATH}
2089 variable, even though, taken individually, neither @file{foo} nor
2090 @file{bar} would lead to that recommendation.
2093 @item --profile=@var{profile}
2094 @itemx -p @var{profile}
2095 Use @var{profile} instead of the user's default profile.
2097 @cindex collisions, in a profile
2098 @cindex colliding packages in profiles
2099 @cindex profile collisions
2100 @item --allow-collisions
2101 Allow colliding packages in the new profile. Use at your own risk!
2103 By default, @command{guix package} reports as an error @dfn{collisions}
2104 in the profile. Collisions happen when two or more different versions
2105 or variants of a given package end up in the profile.
2108 Produce verbose output. In particular, emit the build log of the
2109 environment on the standard error port.
2112 Use the bootstrap Guile to build the profile. This option is only
2113 useful to distribution developers.
2117 In addition to these actions, @command{guix package} supports the
2118 following options to query the current state of a profile, or the
2119 availability of packages:
2123 @item --search=@var{regexp}
2124 @itemx -s @var{regexp}
2125 @cindex searching for packages
2126 List the available packages whose name, synopsis, or description matches
2127 @var{regexp}, sorted by relevance. Print all the metadata of matching packages in
2128 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
2129 GNU recutils manual}).
2131 This allows specific fields to be extracted using the @command{recsel}
2132 command, for instance:
2135 $ guix package -s malloc | recsel -p name,version,relevance
2149 Similarly, to show the name of all the packages available under the
2150 terms of the GNU@tie{}LGPL version 3:
2153 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
2160 It is also possible to refine search results using several @code{-s}
2161 flags. For example, the following command returns a list of board
2165 $ guix package -s '\<board\>' -s game | recsel -p name
2170 If we were to omit @code{-s game}, we would also get software packages
2171 that deal with printed circuit boards; removing the angle brackets
2172 around @code{board} would further add packages that have to do with
2175 And now for a more elaborate example. The following command searches
2176 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
2177 libraries, and prints the name and synopsis of the matching packages:
2180 $ guix package -s crypto -s library | \
2181 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
2185 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
2186 information on @dfn{selection expressions} for @code{recsel -e}.
2188 @item --show=@var{package}
2189 Show details about @var{package}, taken from the list of available packages, in
2190 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
2194 $ guix package --show=python | recsel -p name,version
2202 You may also specify the full name of a package to only get details about a
2203 specific version of it:
2205 $ guix package --show=python@@3.4 | recsel -p name,version
2212 @item --list-installed[=@var{regexp}]
2213 @itemx -I [@var{regexp}]
2214 List the currently installed packages in the specified profile, with the
2215 most recently installed packages shown last. When @var{regexp} is
2216 specified, list only installed packages whose name matches @var{regexp}.
2218 For each installed package, print the following items, separated by
2219 tabs: the package name, its version string, the part of the package that
2220 is installed (for instance, @code{out} for the default output,
2221 @code{include} for its headers, etc.), and the path of this package in
2224 @item --list-available[=@var{regexp}]
2225 @itemx -A [@var{regexp}]
2226 List packages currently available in the distribution for this system
2227 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
2228 installed packages whose name matches @var{regexp}.
2230 For each package, print the following items separated by tabs: its name,
2231 its version string, the parts of the package (@pxref{Packages with
2232 Multiple Outputs}), and the source location of its definition.
2234 @item --list-generations[=@var{pattern}]
2235 @itemx -l [@var{pattern}]
2237 Return a list of generations along with their creation dates; for each
2238 generation, show the installed packages, with the most recently
2239 installed packages shown last. Note that the zeroth generation is never
2242 For each installed package, print the following items, separated by
2243 tabs: the name of a package, its version string, the part of the package
2244 that is installed (@pxref{Packages with Multiple Outputs}), and the
2245 location of this package in the store.
2247 When @var{pattern} is used, the command returns only matching
2248 generations. Valid patterns include:
2251 @item @emph{Integers and comma-separated integers}. Both patterns denote
2252 generation numbers. For instance, @code{--list-generations=1} returns
2255 And @code{--list-generations=1,8,2} outputs three generations in the
2256 specified order. Neither spaces nor trailing commas are allowed.
2258 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
2259 specified generations and everything in between. Note that the start of
2260 a range must be smaller than its end.
2262 It is also possible to omit the endpoint. For example,
2263 @code{--list-generations=2..}, returns all generations starting from the
2266 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
2267 or months by passing an integer along with the first letter of the
2268 duration. For example, @code{--list-generations=20d} lists generations
2269 that are up to 20 days old.
2272 @item --delete-generations[=@var{pattern}]
2273 @itemx -d [@var{pattern}]
2274 When @var{pattern} is omitted, delete all generations except the current
2277 This command accepts the same patterns as @option{--list-generations}.
2278 When @var{pattern} is specified, delete the matching generations. When
2279 @var{pattern} specifies a duration, generations @emph{older} than the
2280 specified duration match. For instance, @code{--delete-generations=1m}
2281 deletes generations that are more than one month old.
2283 If the current generation matches, it is @emph{not} deleted. Also, the
2284 zeroth generation is never deleted.
2286 Note that deleting generations prevents rolling back to them.
2287 Consequently, this command must be used with care.
2291 Finally, since @command{guix package} may actually start build
2292 processes, it supports all the common build options (@pxref{Common Build
2293 Options}). It also supports package transformation options, such as
2294 @option{--with-source} (@pxref{Package Transformation Options}).
2295 However, note that package transformations are lost when upgrading; to
2296 preserve transformations across upgrades, you should define your own
2297 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
2298 (@pxref{Defining Packages}).
2301 @section Substitutes
2304 @cindex pre-built binaries
2305 Guix supports transparent source/binary deployment, which means that it
2306 can either build things locally, or download pre-built items from a
2307 server, or both. We call these pre-built items @dfn{substitutes}---they
2308 are substitutes for local build results. In many cases, downloading a
2309 substitute is much faster than building things locally.
2311 Substitutes can be anything resulting from a derivation build
2312 (@pxref{Derivations}). Of course, in the common case, they are
2313 pre-built package binaries, but source tarballs, for instance, which
2314 also result from derivation builds, can be available as substitutes.
2317 * Official Substitute Server:: One particular source of substitutes.
2318 * Substitute Server Authorization:: How to enable or disable substitutes.
2319 * Substitute Authentication:: How Guix verifies substitutes.
2320 * Proxy Settings:: How to get substitutes via proxy.
2321 * Substitution Failure:: What happens when substitution fails.
2322 * On Trusting Binaries:: How can you trust that binary blob?
2325 @node Official Substitute Server
2326 @subsection Official Substitute Server
2330 The @code{mirror.hydra.gnu.org} server is a front-end to an official build farm
2331 that builds packages from Guix continuously for some
2332 architectures, and makes them available as substitutes. This is the
2333 default source of substitutes; it can be overridden by passing the
2334 @option{--substitute-urls} option either to @command{guix-daemon}
2335 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
2336 or to client tools such as @command{guix package}
2337 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
2340 Substitute URLs can be either HTTP or HTTPS.
2341 HTTPS is recommended because communications are encrypted; conversely,
2342 using HTTP makes all communications visible to an eavesdropper, who
2343 could use the information gathered to determine, for instance, whether
2344 your system has unpatched security vulnerabilities.
2346 Substitutes from the official build farm are enabled by default when
2347 using the Guix System Distribution (@pxref{GNU Distribution}). However,
2348 they are disabled by default when using Guix on a foreign distribution,
2349 unless you have explicitly enabled them via one of the recommended
2350 installation steps (@pxref{Installation}). The following paragraphs
2351 describe how to enable or disable substitutes for the official build
2352 farm; the same procedure can also be used to enable substitutes for any
2353 other substitute server.
2355 @node Substitute Server Authorization
2356 @subsection Substitute Server Authorization
2359 @cindex substitutes, authorization thereof
2360 @cindex access control list (ACL), for substitutes
2361 @cindex ACL (access control list), for substitutes
2362 To allow Guix to download substitutes from @code{hydra.gnu.org} or a
2364 must add its public key to the access control list (ACL) of archive
2365 imports, using the @command{guix archive} command (@pxref{Invoking guix
2366 archive}). Doing so implies that you trust @code{hydra.gnu.org} to not
2367 be compromised and to serve genuine substitutes.
2369 The public key for @code{hydra.gnu.org} is installed along with Guix, in
2370 @code{@var{prefix}/share/guix/hydra.gnu.org.pub}, where @var{prefix} is
2371 the installation prefix of Guix. If you installed Guix from source,
2372 make sure you checked the GPG signature of
2373 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
2374 Then, you can run something like this:
2377 # guix archive --authorize < @var{prefix}/share/guix/hydra.gnu.org.pub
2381 Similarly, the @file{berlin.guixsd.org.pub} file contains the public key
2382 for the project's new build farm, reachable at
2383 @indicateurl{https://berlin.guixsd.org}.
2385 As of this writing @code{berlin.guixsd.org} is being upgraded so it can
2386 better scale up, but you might want to give it a try. It is backed by
2387 20 x86_64/i686 build nodes and may be able to provide substitutes more
2388 quickly than @code{mirror.hydra.gnu.org}.
2391 Once this is in place, the output of a command like @code{guix build}
2392 should change from something like:
2395 $ guix build emacs --dry-run
2396 The following derivations would be built:
2397 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
2398 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
2399 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
2400 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
2408 $ guix build emacs --dry-run
2409 112.3 MB would be downloaded:
2410 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
2411 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
2412 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
2413 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
2418 This indicates that substitutes from @code{hydra.gnu.org} are usable and
2419 will be downloaded, when possible, for future builds.
2421 @cindex substitutes, how to disable
2422 The substitute mechanism can be disabled globally by running
2423 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
2424 guix-daemon}). It can also be disabled temporarily by passing the
2425 @code{--no-substitutes} option to @command{guix package}, @command{guix
2426 build}, and other command-line tools.
2428 @node Substitute Authentication
2429 @subsection Substitute Authentication
2431 @cindex digital signatures
2432 Guix detects and raises an error when attempting to use a substitute
2433 that has been tampered with. Likewise, it ignores substitutes that are
2434 not signed, or that are not signed by one of the keys listed in the ACL.
2436 There is one exception though: if an unauthorized server provides
2437 substitutes that are @emph{bit-for-bit identical} to those provided by
2438 an authorized server, then the unauthorized server becomes eligible for
2439 downloads. For example, assume we have chosen two substitute servers
2443 --substitute-urls="https://a.example.org https://b.example.org"
2447 @cindex reproducible builds
2448 If the ACL contains only the key for @code{b.example.org}, and if
2449 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
2450 then Guix will download substitutes from @code{a.example.org} because it
2451 comes first in the list and can be considered a mirror of
2452 @code{b.example.org}. In practice, independent build machines usually
2453 produce the same binaries, thanks to bit-reproducible builds (see
2456 When using HTTPS, the server's X.509 certificate is @emph{not} validated
2457 (in other words, the server is not authenticated), contrary to what
2458 HTTPS clients such as Web browsers usually do. This is because Guix
2459 authenticates substitute information itself, as explained above, which
2460 is what we care about (whereas X.509 certificates are about
2461 authenticating bindings between domain names and public keys.)
2463 @node Proxy Settings
2464 @subsection Proxy Settings
2467 Substitutes are downloaded over HTTP or HTTPS.
2468 The @code{http_proxy} environment
2469 variable can be set in the environment of @command{guix-daemon} and is
2470 honored for downloads of substitutes. Note that the value of
2471 @code{http_proxy} in the environment where @command{guix build},
2472 @command{guix package}, and other client commands are run has
2473 @emph{absolutely no effect}.
2475 @node Substitution Failure
2476 @subsection Substitution Failure
2478 Even when a substitute for a derivation is available, sometimes the
2479 substitution attempt will fail. This can happen for a variety of
2480 reasons: the substitute server might be offline, the substitute may
2481 recently have been deleted, the connection might have been interrupted,
2484 When substitutes are enabled and a substitute for a derivation is
2485 available, but the substitution attempt fails, Guix will attempt to
2486 build the derivation locally depending on whether or not
2487 @code{--fallback} was given (@pxref{fallback-option,, common build
2488 option @code{--fallback}}). Specifically, if @code{--fallback} was
2489 omitted, then no local build will be performed, and the derivation is
2490 considered to have failed. However, if @code{--fallback} was given,
2491 then Guix will attempt to build the derivation locally, and the success
2492 or failure of the derivation depends on the success or failure of the
2493 local build. Note that when substitutes are disabled or no substitute
2494 is available for the derivation in question, a local build will
2495 @emph{always} be performed, regardless of whether or not
2496 @code{--fallback} was given.
2498 To get an idea of how many substitutes are available right now, you can
2499 try running the @command{guix weather} command (@pxref{Invoking guix
2500 weather}). This command provides statistics on the substitutes provided
2503 @node On Trusting Binaries
2504 @subsection On Trusting Binaries
2506 @cindex trust, of pre-built binaries
2507 Today, each individual's control over their own computing is at the
2508 mercy of institutions, corporations, and groups with enough power and
2509 determination to subvert the computing infrastructure and exploit its
2510 weaknesses. While using @code{hydra.gnu.org} substitutes can be
2511 convenient, we encourage users to also build on their own, or even run
2512 their own build farm, such that @code{hydra.gnu.org} is less of an
2513 interesting target. One way to help is by publishing the software you
2514 build using @command{guix publish} so that others have one more choice
2515 of server to download substitutes from (@pxref{Invoking guix publish}).
2517 Guix has the foundations to maximize build reproducibility
2518 (@pxref{Features}). In most cases, independent builds of a given
2519 package or derivation should yield bit-identical results. Thus, through
2520 a diverse set of independent package builds, we can strengthen the
2521 integrity of our systems. The @command{guix challenge} command aims to
2522 help users assess substitute servers, and to assist developers in
2523 finding out about non-deterministic package builds (@pxref{Invoking guix
2524 challenge}). Similarly, the @option{--check} option of @command{guix
2525 build} allows users to check whether previously-installed substitutes
2526 are genuine by rebuilding them locally (@pxref{build-check,
2527 @command{guix build --check}}).
2529 In the future, we want Guix to have support to publish and retrieve
2530 binaries to/from other users, in a peer-to-peer fashion. If you would
2531 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
2533 @node Packages with Multiple Outputs
2534 @section Packages with Multiple Outputs
2536 @cindex multiple-output packages
2537 @cindex package outputs
2540 Often, packages defined in Guix have a single @dfn{output}---i.e., the
2541 source package leads to exactly one directory in the store. When running
2542 @command{guix package -i glibc}, one installs the default output of the
2543 GNU libc package; the default output is called @code{out}, but its name
2544 can be omitted as shown in this command. In this particular case, the
2545 default output of @code{glibc} contains all the C header files, shared
2546 libraries, static libraries, Info documentation, and other supporting
2549 Sometimes it is more appropriate to separate the various types of files
2550 produced from a single source package into separate outputs. For
2551 instance, the GLib C library (used by GTK+ and related packages)
2552 installs more than 20 MiB of reference documentation as HTML pages.
2553 To save space for users who do not need it, the documentation goes to a
2554 separate output, called @code{doc}. To install the main GLib output,
2555 which contains everything but the documentation, one would run:
2558 guix package -i glib
2561 @cindex documentation
2562 The command to install its documentation is:
2565 guix package -i glib:doc
2568 Some packages install programs with different ``dependency footprints''.
2569 For instance, the WordNet package installs both command-line tools and
2570 graphical user interfaces (GUIs). The former depend solely on the C
2571 library, whereas the latter depend on Tcl/Tk and the underlying X
2572 libraries. In this case, we leave the command-line tools in the default
2573 output, whereas the GUIs are in a separate output. This allows users
2574 who do not need the GUIs to save space. The @command{guix size} command
2575 can help find out about such situations (@pxref{Invoking guix size}).
2576 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
2578 There are several such multiple-output packages in the GNU distribution.
2579 Other conventional output names include @code{lib} for libraries and
2580 possibly header files, @code{bin} for stand-alone programs, and
2581 @code{debug} for debugging information (@pxref{Installing Debugging
2582 Files}). The outputs of a packages are listed in the third column of
2583 the output of @command{guix package --list-available} (@pxref{Invoking
2587 @node Invoking guix gc
2588 @section Invoking @command{guix gc}
2590 @cindex garbage collector
2592 Packages that are installed, but not used, may be @dfn{garbage-collected}.
2593 The @command{guix gc} command allows users to explicitly run the garbage
2594 collector to reclaim space from the @file{/gnu/store} directory. It is
2595 the @emph{only} way to remove files from @file{/gnu/store}---removing
2596 files or directories manually may break it beyond repair!
2599 @cindex garbage collector roots
2600 The garbage collector has a set of known @dfn{roots}: any file under
2601 @file{/gnu/store} reachable from a root is considered @dfn{live} and
2602 cannot be deleted; any other file is considered @dfn{dead} and may be
2603 deleted. The set of garbage collector roots (``GC roots'' for short)
2604 includes default user profiles; by default, the symlinks under
2605 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
2606 added with @command{guix build --root}, for example (@pxref{Invoking
2609 Prior to running @code{guix gc --collect-garbage} to make space, it is
2610 often useful to remove old generations from user profiles; that way, old
2611 package builds referenced by those generations can be reclaimed. This
2612 is achieved by running @code{guix package --delete-generations}
2613 (@pxref{Invoking guix package}).
2615 Our recommendation is to run a garbage collection periodically, or when
2616 you are short on disk space. For instance, to guarantee that at least
2617 5@tie{}GB are available on your disk, simply run:
2623 It is perfectly safe to run as a non-interactive periodic job
2624 (@pxref{Scheduled Job Execution}, for how to set up such a job on
2625 GuixSD). Running @command{guix gc} with no arguments will collect as
2626 much garbage as it can, but that is often inconvenient: you may find
2627 yourself having to rebuild or re-download software that is ``dead'' from
2628 the GC viewpoint but that is necessary to build other pieces of
2629 software---e.g., the compiler tool chain.
2631 The @command{guix gc} command has three modes of operation: it can be
2632 used to garbage-collect any dead files (the default), to delete specific
2633 files (the @code{--delete} option), to print garbage-collector
2634 information, or for more advanced queries. The garbage collection
2635 options are as follows:
2638 @item --collect-garbage[=@var{min}]
2639 @itemx -C [@var{min}]
2640 Collect garbage---i.e., unreachable @file{/gnu/store} files and
2641 sub-directories. This is the default operation when no option is
2644 When @var{min} is given, stop once @var{min} bytes have been collected.
2645 @var{min} may be a number of bytes, or it may include a unit as a
2646 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
2647 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
2649 When @var{min} is omitted, collect all the garbage.
2651 @item --free-space=@var{free}
2652 @itemx -F @var{free}
2653 Collect garbage until @var{free} space is available under
2654 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
2655 as @code{500MiB}, as described above.
2657 When @var{free} or more is already available in @file{/gnu/store}, do
2658 nothing and exit immediately.
2662 Attempt to delete all the store files and directories specified as
2663 arguments. This fails if some of the files are not in the store, or if
2664 they are still live.
2666 @item --list-failures
2667 List store items corresponding to cached build failures.
2669 This prints nothing unless the daemon was started with
2670 @option{--cache-failures} (@pxref{Invoking guix-daemon,
2671 @option{--cache-failures}}).
2673 @item --clear-failures
2674 Remove the specified store items from the failed-build cache.
2676 Again, this option only makes sense when the daemon is started with
2677 @option{--cache-failures}. Otherwise, it does nothing.
2680 Show the list of dead files and directories still present in the
2681 store---i.e., files and directories no longer reachable from any root.
2684 Show the list of live store files and directories.
2688 In addition, the references among existing store files can be queried:
2694 @cindex package dependencies
2695 List the references (respectively, the referrers) of store files given
2701 List the requisites of the store files passed as arguments. Requisites
2702 include the store files themselves, their references, and the references
2703 of these, recursively. In other words, the returned list is the
2704 @dfn{transitive closure} of the store files.
2706 @xref{Invoking guix size}, for a tool to profile the size of the closure
2707 of an element. @xref{Invoking guix graph}, for a tool to visualize
2708 the graph of references.
2712 Return the derivation(s) leading to the given store items
2713 (@pxref{Derivations}).
2715 For example, this command:
2718 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
2722 returns the @file{.drv} file(s) leading to the @code{emacs} package
2723 installed in your profile.
2725 Note that there may be zero matching @file{.drv} files, for instance
2726 because these files have been garbage-collected. There can also be more
2727 than one matching @file{.drv} due to fixed-output derivations.
2730 Lastly, the following options allow you to check the integrity of the
2731 store and to control disk usage.
2735 @item --verify[=@var{options}]
2736 @cindex integrity, of the store
2737 @cindex integrity checking
2738 Verify the integrity of the store.
2740 By default, make sure that all the store items marked as valid in the
2741 database of the daemon actually exist in @file{/gnu/store}.
2743 When provided, @var{options} must be a comma-separated list containing one
2744 or more of @code{contents} and @code{repair}.
2746 When passing @option{--verify=contents}, the daemon computes the
2747 content hash of each store item and compares it against its hash in the
2748 database. Hash mismatches are reported as data corruptions. Because it
2749 traverses @emph{all the files in the store}, this command can take a
2750 long time, especially on systems with a slow disk drive.
2752 @cindex repairing the store
2753 @cindex corruption, recovering from
2754 Using @option{--verify=repair} or @option{--verify=contents,repair}
2755 causes the daemon to try to repair corrupt store items by fetching
2756 substitutes for them (@pxref{Substitutes}). Because repairing is not
2757 atomic, and thus potentially dangerous, it is available only to the
2758 system administrator. A lightweight alternative, when you know exactly
2759 which items in the store are corrupt, is @command{guix build --repair}
2760 (@pxref{Invoking guix build}).
2763 @cindex deduplication
2764 Optimize the store by hard-linking identical files---this is
2765 @dfn{deduplication}.
2767 The daemon performs deduplication after each successful build or archive
2768 import, unless it was started with @code{--disable-deduplication}
2769 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
2770 this option is primarily useful when the daemon was running with
2771 @code{--disable-deduplication}.
2775 @node Invoking guix pull
2776 @section Invoking @command{guix pull}
2778 @cindex upgrading Guix
2779 @cindex updating Guix
2780 @cindex @command{guix pull}
2782 Packages are installed or upgraded to the latest version available in
2783 the distribution currently available on your local machine. To update
2784 that distribution, along with the Guix tools, you must run @command{guix
2785 pull}: the command downloads the latest Guix source code and package
2786 descriptions, and deploys it. Source code is downloaded from a
2787 @uref{https://git-scm.com, Git} repository, by default the official
2788 GNU@tie{}Guix repository, though this can be customized.
2790 On completion, @command{guix package} will use packages and package
2791 versions from this just-retrieved copy of Guix. Not only that, but all
2792 the Guix commands and Scheme modules will also be taken from that latest
2793 version. New @command{guix} sub-commands added by the update also
2796 Any user can update their Guix copy using @command{guix pull}, and the
2797 effect is limited to the user who run @command{guix pull}. For
2798 instance, when user @code{root} runs @command{guix pull}, this has no
2799 effect on the version of Guix that user @code{alice} sees, and vice
2802 The result of running @command{guix pull} is a @dfn{profile} available
2803 under @file{~/.config/guix/current} containing the latest Guix. Thus,
2804 make sure to add it to the beginning of your search path so that you use
2805 the latest version, and similarly for the Info manual
2806 (@pxref{Documentation}):
2809 export PATH="$HOME/.config/guix/current/bin:$PATH"
2810 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
2813 The @code{--list-generations} or @code{-l} option lists past generations
2814 produced by @command{guix pull}, along with details about their provenance:
2818 Generation 1 Jun 10 2018 00:18:18
2820 repository URL: https://git.savannah.gnu.org/git/guix.git
2821 branch: origin/master
2822 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
2824 Generation 2 Jun 11 2018 11:02:49
2826 repository URL: https://git.savannah.gnu.org/git/guix.git
2827 branch: origin/master
2828 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
2829 2 new packages: keepalived, libnfnetlink
2830 6 packages upgraded: emacs-nix-mode@@2.0.4,
2831 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
2832 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
2834 Generation 3 Jun 13 2018 23:31:07 (current)
2836 repository URL: https://git.savannah.gnu.org/git/guix.git
2837 branch: origin/master
2838 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
2839 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
2840 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
2843 @ref{Invoking guix describe, @command{guix describe}}, for other ways to
2844 describe the current status of Guix.
2846 This @code{~/.config/guix/current} profile works like any other profile
2847 created by @command{guix package} (@pxref{Invoking guix package}). That
2848 is, you can list generations, roll back to the previous
2849 generation---i.e., the previous Guix---and so on:
2852 $ guix package -p ~/.config/guix/current --roll-back
2853 switched from generation 3 to 2
2854 $ guix package -p ~/.config/guix/current --delete-generations=1
2855 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
2858 The @command{guix pull} command is usually invoked with no arguments,
2859 but it supports the following options:
2862 @item --url=@var{url}
2863 @itemx --commit=@var{commit}
2864 @itemx --branch=@var{branch}
2865 Download code from the specified @var{url}, at the given @var{commit} (a valid
2866 Git commit ID represented as a hexadecimal string), or @var{branch}.
2868 @cindex @file{channels.scm}, configuration file
2869 @cindex configuration file for channels
2870 These options are provided for convenience, but you can also specify your
2871 configuration in the @file{~/.config/guix/channels.scm} file or using the
2872 @option{--channels} option (see below).
2874 @item --channels=@var{file}
2875 @itemx -C @var{file}
2876 Read the list of channels from @var{file} instead of
2877 @file{~/.config/guix/channels.scm}. @var{file} must contain Scheme code that
2878 evaluates to a list of channel objects. @xref{Channels}, for more
2881 @item --list-generations[=@var{pattern}]
2882 @itemx -l [@var{pattern}]
2883 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
2884 is provided, the subset of generations that match @var{pattern}.
2885 The syntax of @var{pattern} is the same as with @code{guix package
2886 --list-generations} (@pxref{Invoking guix package}).
2888 @ref{Invoking guix describe}, for a way to display information about the
2889 current generation only.
2891 @item --profile=@var{profile}
2892 @itemx -p @var{profile}
2893 Use @var{profile} instead of @file{~/.config/guix/current}.
2897 Show which channel commit(s) would be used and what would be built or
2898 substituted but do not actually do it.
2901 Produce verbose output, writing build logs to the standard error output.
2904 Use the bootstrap Guile to build the latest Guix. This option is only
2905 useful to Guix developers.
2908 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
2909 repository and branch to pull from, as well as @emph{additional} repositories
2910 containing package modules that should be deployed. @xref{Channels}, for more
2913 In addition, @command{guix pull} supports all the common build options
2914 (@pxref{Common Build Options}).
2920 @cindex @file{channels.scm}, configuration file
2921 @cindex configuration file for channels
2922 @cindex @command{guix pull}, configuration file
2923 @cindex configuration of @command{guix pull}
2924 Guix and its package collection are updated by running @command{guix pull}
2925 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
2926 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
2927 customized by defining @dfn{channels} in the
2928 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
2929 of a Git repository to be deployed, and @command{guix pull} can be instructed
2930 to pull from one or more channels. In other words, channels can be used to
2931 @emph{customize} and to @emph{extend} Guix, as we will see below.
2933 @subsection Using a Custom Guix Channel
2935 The channel called @code{guix} specifies where Guix itself---its command-line
2936 tools as well as its package collection---should be downloaded. For instance,
2937 suppose you want to update from your own copy of the Guix repository at
2938 @code{example.org}, and specifically the @code{super-hacks} branch, you can
2939 write in @code{~/.config/guix/channels.scm} this specification:
2942 ;; Tell 'guix pull' to use my own repo.
2945 (url "https://example.org/my-guix.git")
2946 (branch "super-hacks")))
2950 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
2951 branch of the repository at @code{example.org}.
2953 @subsection Specifying Additional Channels
2955 @cindex extending the package collection (channels)
2956 @cindex personal packages (channels)
2957 @cindex channels, for personal packages
2958 You can also specify @emph{additional channels} to pull from. Let's say you
2959 have a bunch of custom package variants or personal packages that you think
2960 would make little sense to contribute to the Guix project, but would like to
2961 have these packages transparently available to you at the command line. You
2962 would first write modules containing those package definitions (@pxref{Package
2963 Modules}), maintain them in a Git repository, and then you and anyone else can
2964 use it as an additional channel to get packages from. Neat, no?
2966 @c What follows stems from discussions at
2967 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
2968 @c earlier discussions on guix-devel@gnu.org.
2970 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
2971 publish your personal channel to the world, we would like to share a few words
2976 Before publishing a channel, please consider contributing your package
2977 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
2978 to free software of all sorts, and packages in Guix proper are readily
2979 available to all Guix users and benefit from the project's quality assurance
2983 When you maintain package definitions outside Guix, we, Guix developers,
2984 consider that @emph{the compatibility burden is on you}. Remember that
2985 package modules and package definitions are just Scheme code that uses various
2986 programming interfaces (APIs). We want to remain free to change these APIs to
2987 keep improving Guix, possibly in ways that break your channel. We never
2988 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
2992 Corollary: if you're using an external channel and that channel breaks, please
2993 @emph{report the issue to the channel authors}, not to the Guix project.
2996 You've been warned! Having said this, we believe external channels are a
2997 practical way to exert your freedom to augment Guix' package collection and to
2998 share your improvements, which are basic tenets of
2999 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3000 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3003 Once you have a Git repository containing your own package modules, you can
3004 write @code{~/.config/guix/channels.scm} to instruct @command{guix pull} to
3005 pull from your personal channel @emph{in addition} to the default Guix
3008 @vindex %default-channels
3010 ;; Add my personal packages to those Guix provides.
3012 (name 'my-personal-packages)
3013 (url "https://example.org/personal-packages.git"))
3018 Note that the snippet above is (as always!) Scheme code; we use @code{cons} to
3019 add a channel the list of channels that the variable @code{%default-channels}
3020 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3021 Manual}). With this file in place, @command{guix pull} builds not only Guix
3022 but also the package modules from your own repository. The result in
3023 @file{~/.config/guix/current} is the union of Guix with your own package
3027 $ guix pull --list-generations
3029 Generation 19 Aug 27 2018 16:20:48
3031 repository URL: https://git.savannah.gnu.org/git/guix.git
3033 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
3034 my-personal-packages dd3df5e
3035 repository URL: https://example.org/personal-packages.git
3037 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
3038 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
3039 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
3043 The output of @command{guix pull} above shows that Generation@tie{}19 includes
3044 both Guix and packages from the @code{my-personal-packages} channel. Among
3045 the new and upgraded packages that are listed, some like @code{my-gimp} and
3046 @code{my-emacs-with-cool-features} might come from
3047 @code{my-personal-packages}, while others come from the Guix default channel.
3049 @subsection Replicating Guix
3051 @cindex pinning, channels
3052 @cindex replicating Guix
3053 @cindex reproducibility, of Guix
3054 The @command{guix pull --list-generations} output above shows precisely which
3055 commits were used to build this instance of Guix. We can thus replicate it,
3056 say, on another machine, by providing a channel specification in
3057 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
3060 ;; Deploy specific commits of my channels of interest.
3063 (url "https://git.savannah.gnu.org/git/guix.git")
3064 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
3066 (name 'my-personal-packages)
3067 (url "https://example.org/personal-packages.git")
3068 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
3071 The @command{guix describe --format=channels} command can even generate this
3072 list of channels directly (@pxref{Invoking guix describe}).
3074 At this point the two machines run the @emph{exact same Guix}, with access to
3075 the @emph{exact same packages}. The output of @command{guix build gimp} on
3076 one machine will be exactly the same, bit for bit, as the output of the same
3077 command on the other machine. It also means both machines have access to all
3078 the source code of Guix and, transitively, to all the source code of every
3081 This gives you super powers, allowing you to track the provenance of binary
3082 artifacts with very fine grain, and to reproduce software environments at
3083 will---some sort of ``meta reproducibility'' capabilities, if you will.
3084 @xref{Inferiors}, for another way to take advantage of these super powers.
3089 @c TODO: Remove this once we're more confident about API stability.
3091 The functionality described here is a ``technology preview'' as of version
3092 @value{VERSION}. As such, the interface is subject to change.
3096 @cindex composition of Guix revisions
3097 Sometimes you might need to mix packages from the revision of Guix you're
3098 currently running with packages available in a different revision of Guix.
3099 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
3100 revisions in arbitrary ways.
3102 @cindex inferior packages
3103 Technically, an ``inferior'' is essentially a separate Guix process connected
3104 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
3105 @code{(guix inferior)} module allows you to create inferiors and to
3106 communicate with them. It also provides a high-level interface to browse and
3107 manipulate the packages that an inferior provides---@dfn{inferior packages}.
3109 When combined with channels (@pxref{Channels}), inferiors provide a simple way
3110 to interact with a separate revision of Guix. For example, let's assume you
3111 want to install in your profile the current @code{guile} package, along with
3112 the @code{guile-json} as it existed in an older revision of Guix---perhaps
3113 because the newer @code{guile-json} has an incompatible API and you want to
3114 run your code against the old API@. To do that, you could write a manifest for
3115 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
3116 manifest, you would create an inferior for that old Guix revision you care
3117 about, and you would look up the @code{guile-json} package in the inferior:
3120 (use-modules (guix inferior) (guix channels)
3121 (srfi srfi-1)) ;for 'first'
3124 ;; This is the old revision from which we want to
3125 ;; extract guile-json.
3128 (url "https://git.savannah.gnu.org/git/guix.git")
3130 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
3133 ;; An inferior representing the above revision.
3134 (inferior-for-channels channels))
3136 ;; Now create a manifest with the current "guile" package
3137 ;; and the old "guile-json" package.
3139 (list (first (lookup-inferior-packages inferior "guile-json"))
3140 (specification->package "guile")))
3143 On its first run, @command{guix package --manifest} might have to build the
3144 channel you specified before it can create the inferior; subsequent runs will
3145 be much faster because the Guix revision will be cached.
3147 The @code{(guix inferior)} module provides the following procedures to open an
3150 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
3151 [#:cache-directory] [#:ttl]
3152 Return an inferior for @var{channels}, a list of channels. Use the cache at
3153 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
3154 This procedure opens a new connection to the build daemon.
3156 As a side effect, this procedure may build or substitute binaries for
3157 @var{channels}, which can take time.
3160 @deffn {Scheme Procedure} open-inferior @var{directory} @
3161 [#:command "bin/guix"]
3162 Open the inferior Guix in @var{directory}, running
3163 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
3164 the inferior could not be launched.
3167 @cindex inferior packages
3168 The procedures listed below allow you to obtain and manipulate inferior
3171 @deffn {Scheme Procedure} inferior-packages @var{inferior}
3172 Return the list of packages known to @var{inferior}.
3175 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
3177 Return the sorted list of inferior packages matching @var{name} in
3178 @var{inferior}, with highest version numbers first. If @var{version} is true,
3179 return only packages with a version number prefixed by @var{version}.
3182 @deffn {Scheme Procedure} inferior-package? @var{obj}
3183 Return true if @var{obj} is an inferior package.
3186 @deffn {Scheme Procedure} inferior-package-name @var{package}
3187 @deffnx {Scheme Procedure} inferior-package-version @var{package}
3188 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
3189 @deffnx {Scheme Procedure} inferior-package-description @var{package}
3190 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
3191 @deffnx {Scheme Procedure} inferior-package-location @var{package}
3192 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
3193 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
3194 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
3195 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
3196 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
3197 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
3198 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
3199 These procedures are the counterpart of package record accessors
3200 (@pxref{package Reference}). Most of them work by querying the inferior
3201 @var{package} comes from, so the inferior must still be live when you call
3205 Inferior packages can be used transparently like any other package or
3206 file-like object in G-expressions (@pxref{G-Expressions}). They are also
3207 transparently handled by the @code{packages->manifest} procedure, which is
3208 commonly use in manifests (@pxref{Invoking guix package, the
3209 @option{--manifest} option of @command{guix package}}). Thus you can insert
3210 an inferior package pretty much anywhere you would insert a regular package:
3211 in manifests, in the @code{packages} field of your @code{operating-system}
3212 declaration, and so on.
3214 @node Invoking guix describe
3215 @section Invoking @command{guix describe}
3217 @cindex reproducibility
3218 @cindex replicating Guix
3219 Often you may want to answer questions like: ``Which revision of Guix am I
3220 using?'' or ``Which channels am I using?'' This is useful information in many
3221 situations: if you want to @emph{replicate} an environment on a different
3222 machine or user account, if you want to report a bug or to determine what
3223 change in the channels you are using caused it, or if you want to record your
3224 system state for reproducibility purposes. The @command{guix describe}
3225 command answers these questions.
3227 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
3228 displays the channel(s) that it was built from, including their repository URL
3229 and commit IDs (@pxref{Channels}):
3233 Generation 10 Sep 03 2018 17:32:44 (current)
3235 repository URL: https://git.savannah.gnu.org/git/guix.git
3237 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
3240 If you're familiar with the Git version control system, this is similar in
3241 spirit to @command{git describe}; the output is also similar to that of
3242 @command{guix pull --list-generations}, but limited to the current generation
3243 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
3244 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
3245 information is all it takes to describe the revision of Guix you're using, and
3246 also to replicate it.
3248 To make it easier to replicate Guix, @command{guix describe} can also be asked
3249 to return a list of channels instead of the human-readable description above:
3252 $ guix describe -f channels
3255 (url "https://git.savannah.gnu.org/git/guix.git")
3257 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
3261 You can save this to a file and feed it to @command{guix pull -C} on some
3262 other machine or at a later point in time, which will instantiate @emph{this
3263 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
3264 From there on, since you're able to deploy the same revision of Guix, you can
3265 just as well @emph{replicate a complete software environment}. We humbly
3266 think that this is @emph{awesome}, and we hope you'll like it too!
3268 The details of the options supported by @command{guix describe} are as
3272 @item --format=@var{format}
3273 @itemx -f @var{format}
3274 Produce output in the specified @var{format}, one of:
3278 produce human-readable output;
3280 produce a list of channel specifications that can be passed to @command{guix
3281 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
3285 produce a list of channel specifications in JSON format;
3287 produce a list of channel specifications in Recutils format.
3290 @item --profile=@var{profile}
3291 @itemx -p @var{profile}
3292 Display information about @var{profile}.
3295 @node Invoking guix pack
3296 @section Invoking @command{guix pack}
3298 Occasionally you want to pass software to people who are not (yet!)
3299 lucky enough to be using Guix. You'd tell them to run @command{guix
3300 package -i @var{something}}, but that's not possible in this case. This
3301 is where @command{guix pack} comes in.
3304 If you are looking for ways to exchange binaries among machines that
3305 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
3306 publish}, and @ref{Invoking guix archive}.
3311 @cindex application bundle
3312 @cindex software bundle
3313 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
3314 @dfn{software bundle}: it creates a tarball or some other archive
3315 containing the binaries of the software you're interested in, and all
3316 its dependencies. The resulting archive can be used on any machine that
3317 does not have Guix, and people can run the exact same binaries as those
3318 you have with Guix. The pack itself is created in a bit-reproducible
3319 fashion, so anyone can verify that it really contains the build results
3320 that you pretend to be shipping.
3322 For example, to create a bundle containing Guile, Emacs, Geiser, and all
3323 their dependencies, you can run:
3326 $ guix pack guile emacs geiser
3328 /gnu/store/@dots{}-pack.tar.gz
3331 The result here is a tarball containing a @file{/gnu/store} directory
3332 with all the relevant packages. The resulting tarball contains a
3333 @dfn{profile} with the three packages of interest; the profile is the
3334 same as would be created by @command{guix package -i}. It is this
3335 mechanism that is used to create Guix's own standalone binary tarball
3336 (@pxref{Binary Installation}).
3338 Users of this pack would have to run
3339 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
3340 find inconvenient. To work around it, you can create, say, a
3341 @file{/opt/gnu/bin} symlink to the profile:
3344 guix pack -S /opt/gnu/bin=bin guile emacs geiser
3348 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
3350 @cindex relocatable binaries, with @command{guix pack}
3351 What if the recipient of your pack does not have root privileges on
3352 their machine, and thus cannot unpack it in the root file system? In
3353 that case, you will want to use the @code{--relocatable} option (see
3354 below). This option produces @dfn{relocatable binaries}, meaning they
3355 they can be placed anywhere in the file system hierarchy: in the example
3356 above, users can unpack your tarball in their home directory and
3357 directly run @file{./opt/gnu/bin/guile}.
3359 @cindex Docker, build an image with guix pack
3360 Alternatively, you can produce a pack in the Docker image format using
3361 the following command:
3364 guix pack -f docker guile emacs geiser
3368 The result is a tarball that can be passed to the @command{docker load}
3370 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
3371 documentation} for more information.
3373 @cindex Singularity, build an image with guix pack
3374 @cindex SquashFS, build an image with guix pack
3375 Yet another option is to produce a SquashFS image with the following
3379 guix pack -f squashfs guile emacs geiser
3383 The result is a SquashFS file system image that can either be mounted or
3384 directly be used as a file system container image with the
3385 @uref{http://singularity.lbl.gov, Singularity container execution
3386 environment}, using commands like @command{singularity shell} or
3387 @command{singularity exec}.
3389 Several command-line options allow you to customize your pack:
3392 @item --format=@var{format}
3393 @itemx -f @var{format}
3394 Produce a pack in the given @var{format}.
3396 The available formats are:
3400 This is the default format. It produces a tarball containing all the
3401 specified binaries and symlinks.
3404 This produces a tarball that follows the
3405 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
3406 Docker Image Specification}.
3409 This produces a SquashFS image containing all the specified binaries and
3410 symlinks, as well as empty mount points for virtual file systems like
3416 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
3417 anywhere in the file system hierarchy and run from there. For example,
3418 if you create a pack containing Bash with:
3421 guix pack -R -S /mybin=bin bash
3425 ... you can copy that pack to a machine that lacks Guix, and from your
3426 home directory as a normal user, run:
3434 In that shell, if you type @code{ls /gnu/store}, you'll notice that
3435 @file{/gnu/store} shows up and contains all the dependencies of
3436 @code{bash}, even though the machine actually lacks @file{/gnu/store}
3437 altogether! That is probably the simplest way to deploy Guix-built
3438 software on a non-Guix machine.
3440 There's a gotcha though: this technique relies on the @dfn{user
3441 namespace} feature of the kernel Linux, which allows unprivileged users
3442 to mount or change root. Old versions of Linux did not support it, and
3443 some GNU/Linux distributions turn it off; on these systems, programs
3444 from the pack @emph{will fail to run}, unless they are unpacked in the
3447 @item --expression=@var{expr}
3448 @itemx -e @var{expr}
3449 Consider the package @var{expr} evaluates to.
3451 This has the same purpose as the same-named option in @command{guix
3452 build} (@pxref{Additional Build Options, @code{--expression} in
3453 @command{guix build}}).
3455 @item --manifest=@var{file}
3456 @itemx -m @var{file}
3457 Use the packages contained in the manifest object returned by the Scheme
3460 This has a similar purpose as the same-named option in @command{guix
3461 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
3462 same manifest files. It allows you to define a collection of packages
3463 once and use it both for creating profiles and for creating archives
3464 for use on machines that do not have Guix installed. Note that you can
3465 specify @emph{either} a manifest file @emph{or} a list of packages,
3468 @item --system=@var{system}
3469 @itemx -s @var{system}
3470 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3471 the system type of the build host.
3473 @item --target=@var{triplet}
3474 @cindex cross-compilation
3475 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
3476 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
3477 configuration triplets,, autoconf, Autoconf}).
3479 @item --compression=@var{tool}
3480 @itemx -C @var{tool}
3481 Compress the resulting tarball using @var{tool}---one of @code{gzip},
3482 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
3484 @item --symlink=@var{spec}
3485 @itemx -S @var{spec}
3486 Add the symlinks specified by @var{spec} to the pack. This option can
3487 appear several times.
3489 @var{spec} has the form @code{@var{source}=@var{target}}, where
3490 @var{source} is the symlink that will be created and @var{target} is the
3493 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
3494 symlink pointing to the @file{bin} sub-directory of the profile.
3496 @item --localstatedir
3497 @itemx --profile-name=@var{name}
3498 Include the ``local state directory'', @file{/var/guix}, in the resulting
3499 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
3500 profile---by default @var{name} is @code{guix-profile}, which corresponds to
3501 @file{~root/.guix-profile}.
3503 @file{/var/guix} contains the store database (@pxref{The Store}) as well
3504 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
3505 the pack means that the store is ``complete'' and manageable by Guix;
3506 not providing it pack means that the store is ``dead'': items cannot be
3507 added to it or removed from it after extraction of the pack.
3509 One use case for this is the Guix self-contained binary tarball
3510 (@pxref{Binary Installation}).
3513 Use the bootstrap binaries to build the pack. This option is only
3514 useful to Guix developers.
3517 In addition, @command{guix pack} supports all the common build options
3518 (@pxref{Common Build Options}) and all the package transformation
3519 options (@pxref{Package Transformation Options}).
3522 @node Invoking guix archive
3523 @section Invoking @command{guix archive}
3525 @cindex @command{guix archive}
3527 The @command{guix archive} command allows users to @dfn{export} files
3528 from the store into a single archive, and to later @dfn{import} them on
3529 a machine that runs Guix.
3530 In particular, it allows store files to be transferred from one machine
3531 to the store on another machine.
3534 If you're looking for a way to produce archives in a format suitable for
3535 tools other than Guix, @pxref{Invoking guix pack}.
3538 @cindex exporting store items
3539 To export store files as an archive to standard output, run:
3542 guix archive --export @var{options} @var{specifications}...
3545 @var{specifications} may be either store file names or package
3546 specifications, as for @command{guix package} (@pxref{Invoking guix
3547 package}). For instance, the following command creates an archive
3548 containing the @code{gui} output of the @code{git} package and the main
3549 output of @code{emacs}:
3552 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
3555 If the specified packages are not built yet, @command{guix archive}
3556 automatically builds them. The build process may be controlled with the
3557 common build options (@pxref{Common Build Options}).
3559 To transfer the @code{emacs} package to a machine connected over SSH,
3563 guix archive --export -r emacs | ssh the-machine guix archive --import
3567 Similarly, a complete user profile may be transferred from one machine
3568 to another like this:
3571 guix archive --export -r $(readlink -f ~/.guix-profile) | \
3572 ssh the-machine guix-archive --import
3576 However, note that, in both examples, all of @code{emacs} and the
3577 profile as well as all of their dependencies are transferred (due to
3578 @code{-r}), regardless of what is already available in the store on the
3579 target machine. The @code{--missing} option can help figure out which
3580 items are missing from the target store. The @command{guix copy}
3581 command simplifies and optimizes this whole process, so this is probably
3582 what you should use in this case (@pxref{Invoking guix copy}).
3584 @cindex nar, archive format
3585 @cindex normalized archive (nar)
3586 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
3587 comparable in spirit to `tar', but with differences
3588 that make it more appropriate for our purposes. First, rather than
3589 recording all Unix metadata for each file, the nar format only mentions
3590 the file type (regular, directory, or symbolic link); Unix permissions
3591 and owner/group are dismissed. Second, the order in which directory
3592 entries are stored always follows the order of file names according to
3593 the C locale collation order. This makes archive production fully
3596 When exporting, the daemon digitally signs the contents of the archive,
3597 and that digital signature is appended. When importing, the daemon
3598 verifies the signature and rejects the import in case of an invalid
3599 signature or if the signing key is not authorized.
3600 @c FIXME: Add xref to daemon doc about signatures.
3602 The main options are:
3606 Export the specified store files or packages (see below.) Write the
3607 resulting archive to the standard output.
3609 Dependencies are @emph{not} included in the output, unless
3610 @code{--recursive} is passed.
3614 When combined with @code{--export}, this instructs @command{guix
3615 archive} to include dependencies of the given items in the archive.
3616 Thus, the resulting archive is self-contained: it contains the closure
3617 of the exported store items.
3620 Read an archive from the standard input, and import the files listed
3621 therein into the store. Abort if the archive has an invalid digital
3622 signature, or if it is signed by a public key not among the authorized
3623 keys (see @code{--authorize} below.)
3626 Read a list of store file names from the standard input, one per line,
3627 and write on the standard output the subset of these files missing from
3630 @item --generate-key[=@var{parameters}]
3631 @cindex signing, archives
3632 Generate a new key pair for the daemon. This is a prerequisite before
3633 archives can be exported with @code{--export}. Note that this operation
3634 usually takes time, because it needs to gather enough entropy to
3635 generate the key pair.
3637 The generated key pair is typically stored under @file{/etc/guix}, in
3638 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
3639 key, which must be kept secret.) When @var{parameters} is omitted,
3640 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
3641 versions before 1.6.0, it is a 4096-bit RSA key.
3642 Alternatively, @var{parameters} can specify
3643 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
3644 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
3645 Libgcrypt Reference Manual}).
3648 @cindex authorizing, archives
3649 Authorize imports signed by the public key passed on standard input.
3650 The public key must be in ``s-expression advanced format''---i.e., the
3651 same format as the @file{signing-key.pub} file.
3653 The list of authorized keys is kept in the human-editable file
3654 @file{/etc/guix/acl}. The file contains
3655 @url{http://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
3656 s-expressions''} and is structured as an access-control list in the
3657 @url{http://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
3660 @item --extract=@var{directory}
3661 @itemx -x @var{directory}
3662 Read a single-item archive as served by substitute servers
3663 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
3664 low-level operation needed in only very narrow use cases; see below.
3666 For example, the following command extracts the substitute for Emacs
3667 served by @code{hydra.gnu.org} to @file{/tmp/emacs}:
3671 https://hydra.gnu.org/nar/@dots{}-emacs-24.5 \
3672 | bunzip2 | guix archive -x /tmp/emacs
3675 Single-item archives are different from multiple-item archives produced
3676 by @command{guix archive --export}; they contain a single store item,
3677 and they do @emph{not} embed a signature. Thus this operation does
3678 @emph{no} signature verification and its output should be considered
3681 The primary purpose of this operation is to facilitate inspection of
3682 archive contents coming from possibly untrusted substitute servers.
3686 @c *********************************************************************
3687 @node Programming Interface
3688 @chapter Programming Interface
3690 GNU Guix provides several Scheme programming interfaces (APIs) to
3691 define, build, and query packages. The first interface allows users to
3692 write high-level package definitions. These definitions refer to
3693 familiar packaging concepts, such as the name and version of a package,
3694 its build system, and its dependencies. These definitions can then be
3695 turned into concrete build actions.
3697 Build actions are performed by the Guix daemon, on behalf of users. In a
3698 standard setup, the daemon has write access to the store---the
3699 @file{/gnu/store} directory---whereas users do not. The recommended
3700 setup also has the daemon perform builds in chroots, under a specific
3701 build users, to minimize interference with the rest of the system.
3704 Lower-level APIs are available to interact with the daemon and the
3705 store. To instruct the daemon to perform a build action, users actually
3706 provide it with a @dfn{derivation}. A derivation is a low-level
3707 representation of the build actions to be taken, and the environment in
3708 which they should occur---derivations are to package definitions what
3709 assembly is to C programs. The term ``derivation'' comes from the fact
3710 that build results @emph{derive} from them.
3712 This chapter describes all these APIs in turn, starting from high-level
3713 package definitions.
3716 * Defining Packages:: Defining new packages.
3717 * Build Systems:: Specifying how packages are built.
3718 * The Store:: Manipulating the package store.
3719 * Derivations:: Low-level interface to package derivations.
3720 * The Store Monad:: Purely functional interface to the store.
3721 * G-Expressions:: Manipulating build expressions.
3722 * Invoking guix repl:: Fiddling with Guix interactively.
3725 @node Defining Packages
3726 @section Defining Packages
3728 The high-level interface to package definitions is implemented in the
3729 @code{(guix packages)} and @code{(guix build-system)} modules. As an
3730 example, the package definition, or @dfn{recipe}, for the GNU Hello
3731 package looks like this:
3734 (define-module (gnu packages hello)
3735 #:use-module (guix packages)
3736 #:use-module (guix download)
3737 #:use-module (guix build-system gnu)
3738 #:use-module (guix licenses)
3739 #:use-module (gnu packages gawk))
3741 (define-public hello
3747 (uri (string-append "mirror://gnu/hello/hello-" version
3751 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
3752 (build-system gnu-build-system)
3753 (arguments '(#:configure-flags '("--enable-silent-rules")))
3754 (inputs `(("gawk" ,gawk)))
3755 (synopsis "Hello, GNU world: An example GNU package")
3756 (description "Guess what GNU Hello prints!")
3757 (home-page "http://www.gnu.org/software/hello/")
3762 Without being a Scheme expert, the reader may have guessed the meaning
3763 of the various fields here. This expression binds the variable
3764 @code{hello} to a @code{<package>} object, which is essentially a record
3765 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
3766 This package object can be inspected using procedures found in the
3767 @code{(guix packages)} module; for instance, @code{(package-name hello)}
3768 returns---surprise!---@code{"hello"}.
3770 With luck, you may be able to import part or all of the definition of
3771 the package you are interested in from another repository, using the
3772 @code{guix import} command (@pxref{Invoking guix import}).
3774 In the example above, @var{hello} is defined in a module of its own,
3775 @code{(gnu packages hello)}. Technically, this is not strictly
3776 necessary, but it is convenient to do so: all the packages defined in
3777 modules under @code{(gnu packages @dots{})} are automatically known to
3778 the command-line tools (@pxref{Package Modules}).
3780 There are a few points worth noting in the above package definition:
3784 The @code{source} field of the package is an @code{<origin>} object
3785 (@pxref{origin Reference}, for the complete reference).
3786 Here, the @code{url-fetch} method from @code{(guix download)} is used,
3787 meaning that the source is a file to be downloaded over FTP or HTTP.
3789 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
3790 the GNU mirrors defined in @code{(guix download)}.
3792 The @code{sha256} field specifies the expected SHA256 hash of the file
3793 being downloaded. It is mandatory, and allows Guix to check the
3794 integrity of the file. The @code{(base32 @dots{})} form introduces the
3795 base32 representation of the hash. You can obtain this information with
3796 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
3797 hash} (@pxref{Invoking guix hash}).
3800 When needed, the @code{origin} form can also have a @code{patches} field
3801 listing patches to be applied, and a @code{snippet} field giving a
3802 Scheme expression to modify the source code.
3805 @cindex GNU Build System
3806 The @code{build-system} field specifies the procedure to build the
3807 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
3808 represents the familiar GNU Build System, where packages may be
3809 configured, built, and installed with the usual @code{./configure &&
3810 make && make check && make install} command sequence.
3813 The @code{arguments} field specifies options for the build system
3814 (@pxref{Build Systems}). Here it is interpreted by
3815 @var{gnu-build-system} as a request run @file{configure} with the
3816 @code{--enable-silent-rules} flag.
3822 What about these quote (@code{'}) characters? They are Scheme syntax to
3823 introduce a literal list; @code{'} is synonymous with @code{quote}.
3824 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
3825 for details. Here the value of the @code{arguments} field is a list of
3826 arguments passed to the build system down the road, as with @code{apply}
3827 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
3830 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
3831 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
3832 @code{#:configure-flags} is a keyword used to pass a keyword argument
3833 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
3837 The @code{inputs} field specifies inputs to the build process---i.e.,
3838 build-time or run-time dependencies of the package. Here, we define an
3839 input called @code{"gawk"} whose value is that of the @var{gawk}
3840 variable; @var{gawk} is itself bound to a @code{<package>} object.
3842 @cindex backquote (quasiquote)
3845 @cindex comma (unquote)
3849 @findex unquote-splicing
3850 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
3851 us to introduce a literal list in the @code{inputs} field, while
3852 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
3853 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
3856 Note that GCC, Coreutils, Bash, and other essential tools do not need to
3857 be specified as inputs here. Instead, @var{gnu-build-system} takes care
3858 of ensuring that they are present (@pxref{Build Systems}).
3860 However, any other dependencies need to be specified in the
3861 @code{inputs} field. Any dependency not specified here will simply be
3862 unavailable to the build process, possibly leading to a build failure.
3865 @xref{package Reference}, for a full description of possible fields.
3867 Once a package definition is in place, the
3868 package may actually be built using the @code{guix build} command-line
3869 tool (@pxref{Invoking guix build}), troubleshooting any build failures
3870 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
3871 package definition using the @command{guix edit} command
3872 (@pxref{Invoking guix edit}).
3873 @xref{Packaging Guidelines}, for
3874 more information on how to test package definitions, and
3875 @ref{Invoking guix lint}, for information on how to check a definition
3876 for style conformance.
3877 @vindex GUIX_PACKAGE_PATH
3878 Lastly, @pxref{Channels}, for information
3879 on how to extend the distribution by adding your own package definitions
3882 Finally, updating the package definition to a new upstream version
3883 can be partly automated by the @command{guix refresh} command
3884 (@pxref{Invoking guix refresh}).
3886 Behind the scenes, a derivation corresponding to the @code{<package>}
3887 object is first computed by the @code{package-derivation} procedure.
3888 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
3889 The build actions it prescribes may then be realized by using the
3890 @code{build-derivations} procedure (@pxref{The Store}).
3892 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
3893 Return the @code{<derivation>} object of @var{package} for @var{system}
3894 (@pxref{Derivations}).
3896 @var{package} must be a valid @code{<package>} object, and @var{system}
3897 must be a string denoting the target system type---e.g.,
3898 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
3899 must be a connection to the daemon, which operates on the store
3900 (@pxref{The Store}).
3904 @cindex cross-compilation
3905 Similarly, it is possible to compute a derivation that cross-builds a
3906 package for some other system:
3908 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
3909 @var{package} @var{target} [@var{system}]
3910 Return the @code{<derivation>} object of @var{package} cross-built from
3911 @var{system} to @var{target}.
3913 @var{target} must be a valid GNU triplet denoting the target hardware
3914 and operating system, such as @code{"mips64el-linux-gnu"}
3915 (@pxref{Configuration Names, GNU configuration triplets,, configure, GNU
3916 Configure and Build System}).
3919 @cindex package transformations
3920 @cindex input rewriting
3921 @cindex dependency tree rewriting
3922 Packages can be manipulated in arbitrary ways. An example of a useful
3923 transformation is @dfn{input rewriting}, whereby the dependency tree of
3924 a package is rewritten by replacing specific inputs by others:
3926 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
3927 [@var{rewrite-name}]
3928 Return a procedure that, when passed a package, replaces its direct and
3929 indirect dependencies (but not its implicit inputs) according to
3930 @var{replacements}. @var{replacements} is a list of package pairs; the
3931 first element of each pair is the package to replace, and the second one
3934 Optionally, @var{rewrite-name} is a one-argument procedure that takes
3935 the name of a package and returns its new name after rewrite.
3939 Consider this example:
3942 (define libressl-instead-of-openssl
3943 ;; This is a procedure to replace OPENSSL by LIBRESSL,
3945 (package-input-rewriting `((,openssl . ,libressl))))
3947 (define git-with-libressl
3948 (libressl-instead-of-openssl git))
3952 Here we first define a rewriting procedure that replaces @var{openssl}
3953 with @var{libressl}. Then we use it to define a @dfn{variant} of the
3954 @var{git} package that uses @var{libressl} instead of @var{openssl}.
3955 This is exactly what the @option{--with-input} command-line option does
3956 (@pxref{Package Transformation Options, @option{--with-input}}).
3958 A more generic procedure to rewrite a package dependency graph is
3959 @code{package-mapping}: it supports arbitrary changes to nodes in the
3962 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
3963 Return a procedure that, given a package, applies @var{proc} to all the packages
3964 depended on and returns the resulting package. The procedure stops recursion
3965 when @var{cut?} returns true for a given package.
3969 * package Reference:: The package data type.
3970 * origin Reference:: The origin data type.
3974 @node package Reference
3975 @subsection @code{package} Reference
3977 This section summarizes all the options available in @code{package}
3978 declarations (@pxref{Defining Packages}).
3980 @deftp {Data Type} package
3981 This is the data type representing a package recipe.
3985 The name of the package, as a string.
3987 @item @code{version}
3988 The version of the package, as a string.
3991 An object telling how the source code for the package should be
3992 acquired. Most of the time, this is an @code{origin} object, which
3993 denotes a file fetched from the Internet (@pxref{origin Reference}). It
3994 can also be any other ``file-like'' object such as a @code{local-file},
3995 which denotes a file from the local file system (@pxref{G-Expressions,
3996 @code{local-file}}).
3998 @item @code{build-system}
3999 The build system that should be used to build the package (@pxref{Build
4002 @item @code{arguments} (default: @code{'()})
4003 The arguments that should be passed to the build system. This is a
4004 list, typically containing sequential keyword-value pairs.
4006 @item @code{inputs} (default: @code{'()})
4007 @itemx @code{native-inputs} (default: @code{'()})
4008 @itemx @code{propagated-inputs} (default: @code{'()})
4009 @cindex inputs, of packages
4010 These fields list dependencies of the package. Each one is a list of
4011 tuples, where each tuple has a label for the input (a string) as its
4012 first element, a package, origin, or derivation as its second element,
4013 and optionally the name of the output thereof that should be used, which
4014 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
4015 more on package outputs). For example, the list below specifies three
4019 `(("libffi" ,libffi)
4020 ("libunistring" ,libunistring)
4021 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
4024 @cindex cross compilation, package dependencies
4025 The distinction between @code{native-inputs} and @code{inputs} is
4026 necessary when considering cross-compilation. When cross-compiling,
4027 dependencies listed in @code{inputs} are built for the @emph{target}
4028 architecture; conversely, dependencies listed in @code{native-inputs}
4029 are built for the architecture of the @emph{build} machine.
4031 @code{native-inputs} is typically used to list tools needed at
4032 build time, but not at run time, such as Autoconf, Automake, pkg-config,
4033 Gettext, or Bison. @command{guix lint} can report likely mistakes in
4034 this area (@pxref{Invoking guix lint}).
4036 @anchor{package-propagated-inputs}
4037 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
4038 specified packages will be automatically installed alongside the package
4039 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
4040 package}}, for information on how @command{guix package} deals with
4043 For example this is necessary when a C/C++ library needs headers of
4044 another library to compile, or when a pkg-config file refers to another
4045 one @i{via} its @code{Requires} field.
4047 Another example where @code{propagated-inputs} is useful is for languages
4048 that lack a facility to record the run-time search path akin to the
4049 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
4050 more. To ensure that libraries written in those languages can find
4051 library code they depend on at run time, run-time dependencies must be
4052 listed in @code{propagated-inputs} rather than @code{inputs}.
4054 @item @code{self-native-input?} (default: @code{#f})
4055 This is a Boolean field telling whether the package should use itself as
4056 a native input when cross-compiling.
4058 @item @code{outputs} (default: @code{'("out")})
4059 The list of output names of the package. @xref{Packages with Multiple
4060 Outputs}, for typical uses of additional outputs.
4062 @item @code{native-search-paths} (default: @code{'()})
4063 @itemx @code{search-paths} (default: @code{'()})
4064 A list of @code{search-path-specification} objects describing
4065 search-path environment variables honored by the package.
4067 @item @code{replacement} (default: @code{#f})
4068 This must be either @code{#f} or a package object that will be used as a
4069 @dfn{replacement} for this package. @xref{Security Updates, grafts},
4072 @item @code{synopsis}
4073 A one-line description of the package.
4075 @item @code{description}
4076 A more elaborate description of the package.
4078 @item @code{license}
4079 @cindex license, of packages
4080 The license of the package; a value from @code{(guix licenses)},
4081 or a list of such values.
4083 @item @code{home-page}
4084 The URL to the home-page of the package, as a string.
4086 @item @code{supported-systems} (default: @var{%supported-systems})
4087 The list of systems supported by the package, as strings of the form
4088 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
4090 @item @code{maintainers} (default: @code{'()})
4091 The list of maintainers of the package, as @code{maintainer} objects.
4093 @item @code{location} (default: source location of the @code{package} form)
4094 The source location of the package. It is useful to override this when
4095 inheriting from another package, in which case this field is not
4096 automatically corrected.
4101 @node origin Reference
4102 @subsection @code{origin} Reference
4104 This section summarizes all the options available in @code{origin}
4105 declarations (@pxref{Defining Packages}).
4107 @deftp {Data Type} origin
4108 This is the data type representing a source code origin.
4112 An object containing the URI of the source. The object type depends on
4113 the @code{method} (see below). For example, when using the
4114 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
4115 values are: a URL represented as a string, or a list thereof.
4118 A procedure that handles the URI.
4123 @item @var{url-fetch} from @code{(guix download)}
4124 download a file from the HTTP, HTTPS, or FTP URL specified in the
4128 @item @var{git-fetch} from @code{(guix git-download)}
4129 clone the Git version control repository, and check out the revision
4130 specified in the @code{uri} field as a @code{git-reference} object; a
4131 @code{git-reference} looks like this:
4135 (url "git://git.debian.org/git/pkg-shadow/shadow")
4136 (commit "v4.1.5.1"))
4141 A bytevector containing the SHA-256 hash of the source. Typically the
4142 @code{base32} form is used here to generate the bytevector from a
4145 You can obtain this information using @code{guix download}
4146 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
4149 @item @code{file-name} (default: @code{#f})
4150 The file name under which the source code should be saved. When this is
4151 @code{#f}, a sensible default value will be used in most cases. In case
4152 the source is fetched from a URL, the file name from the URL will be
4153 used. For version control checkouts, it is recommended to provide the
4154 file name explicitly because the default is not very descriptive.
4156 @item @code{patches} (default: @code{'()})
4157 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
4158 file-like objects}) pointing to patches to be applied to the source.
4160 This list of patches must be unconditional. In particular, it cannot
4161 depend on the value of @code{%current-system} or
4162 @code{%current-target-system}.
4164 @item @code{snippet} (default: @code{#f})
4165 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
4166 in the source directory. This is a convenient way to modify the source,
4167 sometimes more convenient than a patch.
4169 @item @code{patch-flags} (default: @code{'("-p1")})
4170 A list of command-line flags that should be passed to the @code{patch}
4173 @item @code{patch-inputs} (default: @code{#f})
4174 Input packages or derivations to the patching process. When this is
4175 @code{#f}, the usual set of inputs necessary for patching are provided,
4176 such as GNU@tie{}Patch.
4178 @item @code{modules} (default: @code{'()})
4179 A list of Guile modules that should be loaded during the patching
4180 process and while running the code in the @code{snippet} field.
4182 @item @code{patch-guile} (default: @code{#f})
4183 The Guile package that should be used in the patching process. When
4184 this is @code{#f}, a sensible default is used.
4190 @section Build Systems
4192 @cindex build system
4193 Each package definition specifies a @dfn{build system} and arguments for
4194 that build system (@pxref{Defining Packages}). This @code{build-system}
4195 field represents the build procedure of the package, as well as implicit
4196 dependencies of that build procedure.
4198 Build systems are @code{<build-system>} objects. The interface to
4199 create and manipulate them is provided by the @code{(guix build-system)}
4200 module, and actual build systems are exported by specific modules.
4202 @cindex bag (low-level package representation)
4203 Under the hood, build systems first compile package objects to
4204 @dfn{bags}. A @dfn{bag} is like a package, but with less
4205 ornamentation---in other words, a bag is a lower-level representation of
4206 a package, which includes all the inputs of that package, including some
4207 that were implicitly added by the build system. This intermediate
4208 representation is then compiled to a derivation (@pxref{Derivations}).
4210 Build systems accept an optional list of @dfn{arguments}. In package
4211 definitions, these are passed @i{via} the @code{arguments} field
4212 (@pxref{Defining Packages}). They are typically keyword arguments
4213 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
4214 Guile Reference Manual}). The value of these arguments is usually
4215 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
4216 by the daemon (@pxref{Derivations}).
4218 The main build system is @var{gnu-build-system}, which implements the
4219 standard build procedure for GNU and many other packages. It
4220 is provided by the @code{(guix build-system gnu)} module.
4222 @defvr {Scheme Variable} gnu-build-system
4223 @var{gnu-build-system} represents the GNU Build System, and variants
4224 thereof (@pxref{Configuration, configuration and makefile conventions,,
4225 standards, GNU Coding Standards}).
4227 @cindex build phases
4228 In a nutshell, packages using it are configured, built, and installed with
4229 the usual @code{./configure && make && make check && make install}
4230 command sequence. In practice, a few additional steps are often needed.
4231 All these steps are split up in separate @dfn{phases},
4232 notably@footnote{Please see the @code{(guix build gnu-build-system)}
4233 modules for more details about the build phases.}:
4237 Unpack the source tarball, and change the current directory to the
4238 extracted source tree. If the source is actually a directory, copy it
4239 to the build tree, and enter that directory.
4241 @item patch-source-shebangs
4242 Patch shebangs encountered in source files so they refer to the right
4243 store file names. For instance, this changes @code{#!/bin/sh} to
4244 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
4247 Run the @file{configure} script with a number of default options, such
4248 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
4249 by the @code{#:configure-flags} argument.
4252 Run @code{make} with the list of flags specified with
4253 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
4254 (the default), build with @code{make -j}.
4257 Run @code{make check}, or some other target specified with
4258 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
4259 @code{#:parallel-tests?} argument is true (the default), run @code{make
4263 Run @code{make install} with the flags listed in @code{#:make-flags}.
4265 @item patch-shebangs
4266 Patch shebangs on the installed executable files.
4269 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
4270 is false), copying them to the @code{debug} output when available
4271 (@pxref{Installing Debugging Files}).
4274 @vindex %standard-phases
4275 The build-side module @code{(guix build gnu-build-system)} defines
4276 @var{%standard-phases} as the default list of build phases.
4277 @var{%standard-phases} is a list of symbol/procedure pairs, where the
4278 procedure implements the actual phase.
4280 The list of phases used for a particular package can be changed with the
4281 @code{#:phases} parameter. For instance, passing:
4284 #:phases (modify-phases %standard-phases (delete 'configure))
4287 means that all the phases described above will be used, except the
4288 @code{configure} phase.
4290 In addition, this build system ensures that the ``standard'' environment
4291 for GNU packages is available. This includes tools such as GCC, libc,
4292 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
4293 build-system gnu)} module for a complete list). We call these the
4294 @dfn{implicit inputs} of a package, because package definitions do not
4295 have to mention them.
4298 Other @code{<build-system>} objects are defined to support other
4299 conventions and tools used by free software packages. They inherit most
4300 of @var{gnu-build-system}, and differ mainly in the set of inputs
4301 implicitly added to the build process, and in the list of phases
4302 executed. Some of these build systems are listed below.
4304 @defvr {Scheme Variable} ant-build-system
4305 This variable is exported by @code{(guix build-system ant)}. It
4306 implements the build procedure for Java packages that can be built with
4307 @url{http://ant.apache.org/, Ant build tool}.
4309 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
4310 provided by the @code{icedtea} package to the set of inputs. Different
4311 packages can be specified with the @code{#:ant} and @code{#:jdk}
4312 parameters, respectively.
4314 When the original package does not provide a suitable Ant build file,
4315 the parameter @code{#:jar-name} can be used to generate a minimal Ant
4316 build file @file{build.xml} with tasks to build the specified jar
4317 archive. In this case the parameter @code{#:source-dir} can be used to
4318 specify the source sub-directory, defaulting to ``src''.
4320 The @code{#:main-class} parameter can be used with the minimal ant
4321 buildfile to specify the main class of the resulting jar. This makes the
4322 jar file executable. The @code{#:test-include} parameter can be used to
4323 specify the list of junit tests to run. It defaults to
4324 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
4325 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
4326 because abstract classes cannot be run as tests.
4328 The parameter @code{#:build-target} can be used to specify the Ant task
4329 that should be run during the @code{build} phase. By default the
4330 ``jar'' task will be run.
4334 @defvr {Scheme Variable} android-ndk-build-system
4335 @cindex Android distribution
4336 @cindex Android NDK build system
4337 This variable is exported by @code{(guix build-system android-ndk)}. It
4338 implements a build procedure for Android NDK (native development kit)
4339 packages using a Guix-specific build process.
4341 The build system assumes that packages install their public interface
4342 (header) files to the subdirectory "include" of the "out" output and
4343 their libraries to the subdirectory "lib" of the "out" output.
4345 It's also assumed that the union of all the dependencies of a package
4346 has no conflicting files.
4348 For the time being, cross-compilation is not supported - so right now
4349 the libraries and header files are assumed to be host tools.
4353 @defvr {Scheme Variable} asdf-build-system/source
4354 @defvrx {Scheme Variable} asdf-build-system/sbcl
4355 @defvrx {Scheme Variable} asdf-build-system/ecl
4357 These variables, exported by @code{(guix build-system asdf)}, implement
4358 build procedures for Common Lisp packages using
4359 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
4360 definition facility for Common Lisp programs and libraries.
4362 The @code{asdf-build-system/source} system installs the packages in
4363 source form, and can be loaded using any common lisp implementation, via
4364 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
4365 systems in the format which a particular implementation understands.
4366 These build systems can also be used to produce executable programs, or
4367 lisp images which contain a set of packages pre-loaded.
4369 The build system uses naming conventions. For binary packages, the
4370 package name should be prefixed with the lisp implementation, such as
4371 @code{sbcl-} for @code{asdf-build-system/sbcl}.
4373 Additionally, the corresponding source package should be labeled using
4374 the same convention as python packages (see @ref{Python Modules}), using
4375 the @code{cl-} prefix.
4377 For binary packages, each system should be defined as a Guix package.
4378 If one package @code{origin} contains several systems, package variants
4379 can be created in order to build all the systems. Source packages,
4380 which use @code{asdf-build-system/source}, may contain several systems.
4382 In order to create executable programs and images, the build-side
4383 procedures @code{build-program} and @code{build-image} can be used.
4384 They should be called in a build phase after the @code{create-symlinks}
4385 phase, so that the system which was just built can be used within the
4386 resulting image. @code{build-program} requires a list of Common Lisp
4387 expressions to be passed as the @code{#:entry-program} argument.
4389 If the system is not defined within its own @code{.asd} file of the same
4390 name, then the @code{#:asd-file} parameter should be used to specify
4391 which file the system is defined in. Furthermore, if the package
4392 defines a system for its tests in a separate file, it will be loaded
4393 before the tests are run if it is specified by the
4394 @code{#:test-asd-file} parameter. If it is not set, the files
4395 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
4396 and @code{test.asd} will be tried if they exist.
4398 If for some reason the package must be named in a different way than the
4399 naming conventions suggest, the @code{#:asd-system-name} parameter can
4400 be used to specify the name of the system.
4404 @defvr {Scheme Variable} cargo-build-system
4405 @cindex Rust programming language
4406 @cindex Cargo (Rust build system)
4407 This variable is exported by @code{(guix build-system cargo)}. It
4408 supports builds of packages using Cargo, the build tool of the
4409 @uref{https://www.rust-lang.org, Rust programming language}.
4411 In its @code{configure} phase, this build system replaces dependencies
4412 specified in the @file{Carto.toml} file with inputs to the Guix package.
4413 The @code{install} phase installs the binaries, and it also installs the
4414 source code and @file{Cargo.toml} file.
4417 @cindex Clojure (programming language)
4418 @cindex simple Clojure build system
4419 @defvr {Scheme Variable} clojure-build-system
4420 This variable is exported by @code{(guix build-system clojure)}. It implements
4421 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
4422 using plain old @code{compile} in Clojure. Cross-compilation is not supported
4425 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
4426 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
4427 @code{#:zip} parameters, respectively.
4429 A list of source directories, test directories and jar names can be specified
4430 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
4431 parameters, respectively. Compile directory and main class can be specified
4432 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
4433 Other parameters are documented below.
4435 This build system is an extension of @var{ant-build-system}, but with the
4436 following phases changed:
4441 This phase calls @code{compile} in Clojure to compile source files and runs
4442 @command{jar} to create jars from both source files and compiled files
4443 according to the include list and exclude list specified in
4444 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
4445 has priority over the include list. These lists consist of symbols
4446 representing Clojure libraries or the special keyword @code{#:all} representing
4447 all Clojure libraries found under the source directories. The parameter
4448 @code{#:omit-source?} decides if source should be included into the jars.
4451 This phase runs tests according to the include list and exclude list specified
4452 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
4453 meanings are analogous to that of @code{#:aot-include} and
4454 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
4455 stands for all Clojure libraries found under the test directories. The
4456 parameter @code{#:tests?} decides if tests should be run.
4459 This phase installs all jars built previously.
4462 Apart from the above, this build system also contains an additional phase:
4467 This phase installs all top-level files with base name matching
4468 @var{%doc-regex}. A different regex can be specified with the
4469 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
4470 directories specified in @code{#:doc-dirs} are installed as well.
4474 @defvr {Scheme Variable} cmake-build-system
4475 This variable is exported by @code{(guix build-system cmake)}. It
4476 implements the build procedure for packages using the
4477 @url{http://www.cmake.org, CMake build tool}.
4479 It automatically adds the @code{cmake} package to the set of inputs.
4480 Which package is used can be specified with the @code{#:cmake}
4483 The @code{#:configure-flags} parameter is taken as a list of flags
4484 passed to the @command{cmake} command. The @code{#:build-type}
4485 parameter specifies in abstract terms the flags passed to the compiler;
4486 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
4487 debugging information''), which roughly means that code is compiled with
4488 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
4491 @defvr {Scheme Variable} go-build-system
4492 This variable is exported by @code{(guix build-system go)}. It
4493 implements a build procedure for Go packages using the standard
4494 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
4495 Go build mechanisms}.
4497 The user is expected to provide a value for the key @code{#:import-path}
4498 and, in some cases, @code{#:unpack-path}. The
4499 @url{https://golang.org/doc/code.html#ImportPaths, import path}
4500 corresponds to the file system path expected by the package's build
4501 scripts and any referring packages, and provides a unique way to
4502 refer to a Go package. It is typically based on a combination of the
4503 package source code's remote URI and file system hierarchy structure. In
4504 some cases, you will need to unpack the package's source code to a
4505 different directory structure than the one indicated by the import path,
4506 and @code{#:unpack-path} should be used in such cases.
4508 Packages that provide Go libraries should be installed along with their
4509 source code. The key @code{#:install-source?}, which defaults to
4510 @code{#t}, controls whether or not the source code is installed. It can
4511 be set to @code{#f} for packages that only provide executable files.
4514 @defvr {Scheme Variable} glib-or-gtk-build-system
4515 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
4516 is intended for use with packages making use of GLib or GTK+.
4518 This build system adds the following two phases to the ones defined by
4519 @var{gnu-build-system}:
4522 @item glib-or-gtk-wrap
4523 The phase @code{glib-or-gtk-wrap} ensures that programs in
4524 @file{bin/} are able to find GLib ``schemas'' and
4525 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
4526 modules}. This is achieved by wrapping the programs in launch scripts
4527 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
4528 environment variables.
4530 It is possible to exclude specific package outputs from that wrapping
4531 process by listing their names in the
4532 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
4533 when an output is known not to contain any GLib or GTK+ binaries, and
4534 where wrapping would gratuitously add a dependency of that output on
4537 @item glib-or-gtk-compile-schemas
4538 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
4539 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
4540 GSettings schemas} of GLib are compiled. Compilation is performed by the
4541 @command{glib-compile-schemas} program. It is provided by the package
4542 @code{glib:bin} which is automatically imported by the build system.
4543 The @code{glib} package providing @command{glib-compile-schemas} can be
4544 specified with the @code{#:glib} parameter.
4547 Both phases are executed after the @code{install} phase.
4550 @defvr {Scheme Variable} guile-build-system
4551 This build system is for Guile packages that consist exclusively of Scheme
4552 code and that are so lean that they don't even have a makefile, let alone a
4553 @file{configure} script. It compiles Scheme code using @command{guild
4554 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
4555 installs the @file{.scm} and @file{.go} files in the right place. It also
4556 installs documentation.
4558 This build system supports cross-compilation by using the @code{--target}
4559 option of @command{guild compile}.
4561 Packages built with @code{guile-build-system} must provide a Guile package in
4562 their @code{native-inputs} field.
4565 @defvr {Scheme Variable} minify-build-system
4566 This variable is exported by @code{(guix build-system minify)}. It
4567 implements a minification procedure for simple JavaScript packages.
4569 It adds @code{uglify-js} to the set of inputs and uses it to compress
4570 all JavaScript files in the @file{src} directory. A different minifier
4571 package can be specified with the @code{#:uglify-js} parameter, but it
4572 is expected that the package writes the minified code to the standard
4575 When the input JavaScript files are not all located in the @file{src}
4576 directory, the parameter @code{#:javascript-files} can be used to
4577 specify a list of file names to feed to the minifier.
4580 @defvr {Scheme Variable} ocaml-build-system
4581 This variable is exported by @code{(guix build-system ocaml)}. It implements
4582 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
4583 of choosing the correct set of commands to run for each package. OCaml
4584 packages can expect many different commands to be run. This build system will
4587 When the package has a @file{setup.ml} file present at the top-level, it will
4588 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
4589 @code{ocaml setup.ml -install}. The build system will assume that this file
4590 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
4591 care of setting the prefix and enabling tests if they are not disabled. You
4592 can pass configure and build flags with the @code{#:configure-flags} and
4593 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
4594 set of flags used to enable tests. The @code{#:use-make?} key can be used to
4595 bypass this system in the build and install phases.
4597 When the package has a @file{configure} file, it is assumed that it is a
4598 hand-made configure script that requires a different argument format than
4599 in the @code{gnu-build-system}. You can add more flags with the
4600 @code{#:configure-flags} key.
4602 When the package has a @file{Makefile} file (or @code{#:use-make?} is
4603 @code{#t}), it will be used and more flags can be passed to the build and
4604 install phases with the @code{#:make-flags} key.
4606 Finally, some packages do not have these files and use a somewhat standard
4607 location for its build system. In that case, the build system will run
4608 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
4609 providing the path to the required findlib module. Additional flags can
4610 be passed via the @code{#:build-flags} key. Install is taken care of by
4611 @command{opam-installer}. In this case, the @code{opam} package must
4612 be added to the @code{native-inputs} field of the package definition.
4614 Note that most OCaml packages assume they will be installed in the same
4615 directory as OCaml, which is not what we want in guix. In particular, they
4616 will install @file{.so} files in their module's directory, which is usually
4617 fine because it is in the OCaml compiler directory. In guix though, these
4618 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
4619 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
4620 @file{.so} libraries should be installed.
4623 @defvr {Scheme Variable} python-build-system
4624 This variable is exported by @code{(guix build-system python)}. It
4625 implements the more or less standard build procedure used by Python
4626 packages, which consists in running @code{python setup.py build} and
4627 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
4629 For packages that install stand-alone Python programs under @code{bin/},
4630 it takes care of wrapping these programs so that their @code{PYTHONPATH}
4631 environment variable points to all the Python libraries they depend on.
4633 Which Python package is used to perform the build can be specified with
4634 the @code{#:python} parameter. This is a useful way to force a package
4635 to be built for a specific version of the Python interpreter, which
4636 might be necessary if the package is only compatible with a single
4637 interpreter version.
4639 By default guix calls @code{setup.py} under control of
4640 @code{setuptools}, much like @command{pip} does. Some packages are not
4641 compatible with setuptools (and pip), thus you can disable this by
4642 setting the @code{#:use-setuptools} parameter to @code{#f}.
4645 @defvr {Scheme Variable} perl-build-system
4646 This variable is exported by @code{(guix build-system perl)}. It
4647 implements the standard build procedure for Perl packages, which either
4648 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
4649 followed by @code{Build} and @code{Build install}; or in running
4650 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
4651 @code{make} and @code{make install}, depending on which of
4652 @code{Build.PL} or @code{Makefile.PL} is present in the package
4653 distribution. Preference is given to the former if both @code{Build.PL}
4654 and @code{Makefile.PL} exist in the package distribution. This
4655 preference can be reversed by specifying @code{#t} for the
4656 @code{#:make-maker?} parameter.
4658 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
4659 passes flags specified by the @code{#:make-maker-flags} or
4660 @code{#:module-build-flags} parameter, respectively.
4662 Which Perl package is used can be specified with @code{#:perl}.
4665 @defvr {Scheme Variable} r-build-system
4666 This variable is exported by @code{(guix build-system r)}. It
4667 implements the build procedure used by @uref{http://r-project.org, R}
4668 packages, which essentially is little more than running @code{R CMD
4669 INSTALL --library=/gnu/store/@dots{}} in an environment where
4670 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
4671 are run after installation using the R function
4672 @code{tools::testInstalledPackage}.
4675 @defvr {Scheme Variable} texlive-build-system
4676 This variable is exported by @code{(guix build-system texlive)}. It is
4677 used to build TeX packages in batch mode with a specified engine. The
4678 build system sets the @code{TEXINPUTS} variable to find all TeX source
4679 files in the inputs.
4681 By default it runs @code{luatex} on all files ending on @code{ins}. A
4682 different engine and format can be specified with the
4683 @code{#:tex-format} argument. Different build targets can be specified
4684 with the @code{#:build-targets} argument, which expects a list of file
4685 names. The build system adds only @code{texlive-bin} and
4686 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
4687 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
4688 and @code{#:texlive-latex-base}, respectively.
4690 The @code{#:tex-directory} parameter tells the build system where to
4691 install the built files under the texmf tree.
4694 @defvr {Scheme Variable} ruby-build-system
4695 This variable is exported by @code{(guix build-system ruby)}. It
4696 implements the RubyGems build procedure used by Ruby packages, which
4697 involves running @code{gem build} followed by @code{gem install}.
4699 The @code{source} field of a package that uses this build system
4700 typically references a gem archive, since this is the format that Ruby
4701 developers use when releasing their software. The build system unpacks
4702 the gem archive, potentially patches the source, runs the test suite,
4703 repackages the gem, and installs it. Additionally, directories and
4704 tarballs may be referenced to allow building unreleased gems from Git or
4705 a traditional source release tarball.
4707 Which Ruby package is used can be specified with the @code{#:ruby}
4708 parameter. A list of additional flags to be passed to the @command{gem}
4709 command can be specified with the @code{#:gem-flags} parameter.
4712 @defvr {Scheme Variable} waf-build-system
4713 This variable is exported by @code{(guix build-system waf)}. It
4714 implements a build procedure around the @code{waf} script. The common
4715 phases---@code{configure}, @code{build}, and @code{install}---are
4716 implemented by passing their names as arguments to the @code{waf}
4719 The @code{waf} script is executed by the Python interpreter. Which
4720 Python package is used to run the script can be specified with the
4721 @code{#:python} parameter.
4724 @defvr {Scheme Variable} scons-build-system
4725 This variable is exported by @code{(guix build-system scons)}. It
4726 implements the build procedure used by the SCons software construction
4727 tool. This build system runs @code{scons} to build the package,
4728 @code{scons test} to run tests, and then @code{scons install} to install
4731 Additional flags to be passed to @code{scons} can be specified with the
4732 @code{#:scons-flags} parameter. The version of Python used to run SCons
4733 can be specified by selecting the appropriate SCons package with the
4734 @code{#:scons} parameter.
4737 @defvr {Scheme Variable} haskell-build-system
4738 This variable is exported by @code{(guix build-system haskell)}. It
4739 implements the Cabal build procedure used by Haskell packages, which
4740 involves running @code{runhaskell Setup.hs configure
4741 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
4742 Instead of installing the package by running @code{runhaskell Setup.hs
4743 install}, to avoid trying to register libraries in the read-only
4744 compiler store directory, the build system uses @code{runhaskell
4745 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
4746 addition, the build system generates the package documentation by
4747 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
4748 is passed. Optional Haddock parameters can be passed with the help of
4749 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
4750 not found, the build system looks for @code{Setup.lhs} instead.
4752 Which Haskell compiler is used can be specified with the @code{#:haskell}
4753 parameter which defaults to @code{ghc}.
4756 @defvr {Scheme Variable} dub-build-system
4757 This variable is exported by @code{(guix build-system dub)}. It
4758 implements the Dub build procedure used by D packages, which
4759 involves running @code{dub build} and @code{dub run}.
4760 Installation is done by copying the files manually.
4762 Which D compiler is used can be specified with the @code{#:ldc}
4763 parameter which defaults to @code{ldc}.
4766 @defvr {Scheme Variable} emacs-build-system
4767 This variable is exported by @code{(guix build-system emacs)}. It
4768 implements an installation procedure similar to the packaging system
4769 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
4771 It first creates the @code{@var{package}-autoloads.el} file, then it
4772 byte compiles all Emacs Lisp files. Differently from the Emacs
4773 packaging system, the Info documentation files are moved to the standard
4774 documentation directory and the @file{dir} file is deleted. Each
4775 package is installed in its own directory under
4776 @file{share/emacs/site-lisp/guix.d}.
4779 @defvr {Scheme Variable} font-build-system
4780 This variable is exported by @code{(guix build-system font)}. It
4781 implements an installation procedure for font packages where upstream
4782 provides pre-compiled TrueType, OpenType, etc. font files that merely
4783 need to be copied into place. It copies font files to standard
4784 locations in the output directory.
4787 @defvr {Scheme Variable} meson-build-system
4788 This variable is exported by @code{(guix build-system meson)}. It
4789 implements the build procedure for packages that use
4790 @url{http://mesonbuild.com, Meson} as their build system.
4792 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
4793 of inputs, and they can be changed with the parameters @code{#:meson}
4794 and @code{#:ninja} if needed. The default Meson is
4795 @code{meson-for-build}, which is special because it doesn't clear the
4796 @code{RUNPATH} of binaries and libraries when they are installed.
4798 This build system is an extension of @var{gnu-build-system}, but with the
4799 following phases changed to some specific for Meson:
4804 The phase runs @code{meson} with the flags specified in
4805 @code{#:configure-flags}. The flag @code{--build-type} is always set to
4806 @code{plain} unless something else is specified in @code{#:build-type}.
4809 The phase runs @code{ninja} to build the package in parallel by default, but
4810 this can be changed with @code{#:parallel-build?}.
4813 The phase runs @code{ninja} with the target specified in @code{#:test-target},
4814 which is @code{"test"} by default.
4817 The phase runs @code{ninja install} and can not be changed.
4820 Apart from that, the build system also adds the following phases:
4825 This phase ensures that all binaries can find the libraries they need.
4826 It searches for required libraries in subdirectories of the package being
4827 built, and adds those to @code{RUNPATH} where needed. It also removes
4828 references to libraries left over from the build phase by
4829 @code{meson-for-build}, such as test dependencies, that aren't actually
4830 required for the program to run.
4832 @item glib-or-gtk-wrap
4833 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
4834 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
4836 @item glib-or-gtk-compile-schemas
4837 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
4838 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
4842 Lastly, for packages that do not need anything as sophisticated, a
4843 ``trivial'' build system is provided. It is trivial in the sense that
4844 it provides basically no support: it does not pull any implicit inputs,
4845 and does not have a notion of build phases.
4847 @defvr {Scheme Variable} trivial-build-system
4848 This variable is exported by @code{(guix build-system trivial)}.
4850 This build system requires a @code{#:builder} argument. This argument
4851 must be a Scheme expression that builds the package output(s)---as
4852 with @code{build-expression->derivation} (@pxref{Derivations,
4853 @code{build-expression->derivation}}).
4863 Conceptually, the @dfn{store} is the place where derivations that have
4864 been built successfully are stored---by default, @file{/gnu/store}.
4865 Sub-directories in the store are referred to as @dfn{store items} or
4866 sometimes @dfn{store paths}. The store has an associated database that
4867 contains information such as the store paths referred to by each store
4868 path, and the list of @emph{valid} store items---results of successful
4869 builds. This database resides in @file{@var{localstatedir}/guix/db},
4870 where @var{localstatedir} is the state directory specified @i{via}
4871 @option{--localstatedir} at configure time, usually @file{/var}.
4873 The store is @emph{always} accessed by the daemon on behalf of its clients
4874 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
4875 connect to the daemon over a Unix-domain socket, send requests to it,
4876 and read the result---these are remote procedure calls, or RPCs.
4879 Users must @emph{never} modify files under @file{/gnu/store} directly.
4880 This would lead to inconsistencies and break the immutability
4881 assumptions of Guix's functional model (@pxref{Introduction}).
4883 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
4884 how to check the integrity of the store and attempt recovery from
4885 accidental modifications.
4888 The @code{(guix store)} module provides procedures to connect to the
4889 daemon, and to perform RPCs. These are described below. By default,
4890 @code{open-connection}, and thus all the @command{guix} commands,
4891 connect to the local daemon or to the URI specified by the
4892 @code{GUIX_DAEMON_SOCKET} environment variable.
4894 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
4895 When set, the value of this variable should be a file name or a URI
4896 designating the daemon endpoint. When it is a file name, it denotes a
4897 Unix-domain socket to connect to. In addition to file names, the
4898 supported URI schemes are:
4903 These are for Unix-domain sockets.
4904 @code{file:///var/guix/daemon-socket/socket} is equivalent to
4905 @file{/var/guix/daemon-socket/socket}.
4908 @cindex daemon, remote access
4909 @cindex remote access to the daemon
4910 @cindex daemon, cluster setup
4911 @cindex clusters, daemon setup
4912 These URIs denote connections over TCP/IP, without encryption nor
4913 authentication of the remote host. The URI must specify the host name
4914 and optionally a port number (by default port 44146 is used):
4917 guix://master.guix.example.org:1234
4920 This setup is suitable on local networks, such as clusters, where only
4921 trusted nodes may connect to the build daemon at
4922 @code{master.guix.example.org}.
4924 The @code{--listen} option of @command{guix-daemon} can be used to
4925 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
4929 @cindex SSH access to build daemons
4930 These URIs allow you to connect to a remote daemon over
4931 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
4932 A typical URL might look like this:
4935 ssh://charlie@@guix.example.org:22
4938 As for @command{guix copy}, the usual OpenSSH client configuration files
4939 are honored (@pxref{Invoking guix copy}).
4942 Additional URI schemes may be supported in the future.
4944 @c XXX: Remove this note when the protocol incurs fewer round trips
4945 @c and when (guix derivations) no longer relies on file system access.
4947 The ability to connect to remote build daemons is considered
4948 experimental as of @value{VERSION}. Please get in touch with us to
4949 share any problems or suggestions you may have (@pxref{Contributing}).
4953 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
4954 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
4955 @var{reserve-space?} is true, instruct it to reserve a little bit of
4956 extra space on the file system so that the garbage collector can still
4957 operate should the disk become full. Return a server object.
4959 @var{file} defaults to @var{%default-socket-path}, which is the normal
4960 location given the options that were passed to @command{configure}.
4963 @deffn {Scheme Procedure} close-connection @var{server}
4964 Close the connection to @var{server}.
4967 @defvr {Scheme Variable} current-build-output-port
4968 This variable is bound to a SRFI-39 parameter, which refers to the port
4969 where build and error logs sent by the daemon should be written.
4972 Procedures that make RPCs all take a server object as their first
4975 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
4976 @cindex invalid store items
4977 Return @code{#t} when @var{path} designates a valid store item and
4978 @code{#f} otherwise (an invalid item may exist on disk but still be
4979 invalid, for instance because it is the result of an aborted or failed
4982 A @code{&nix-protocol-error} condition is raised if @var{path} is not
4983 prefixed by the store directory (@file{/gnu/store}).
4986 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
4987 Add @var{text} under file @var{name} in the store, and return its store
4988 path. @var{references} is the list of store paths referred to by the
4989 resulting store path.
4992 @deffn {Scheme Procedure} build-derivations @var{server} @var{derivations}
4993 Build @var{derivations} (a list of @code{<derivation>} objects or
4994 derivation paths), and return when the worker is done building them.
4995 Return @code{#t} on success.
4998 Note that the @code{(guix monads)} module provides a monad as well as
4999 monadic versions of the above procedures, with the goal of making it
5000 more convenient to work with code that accesses the store (@pxref{The
5004 @i{This section is currently incomplete.}
5007 @section Derivations
5010 Low-level build actions and the environment in which they are performed
5011 are represented by @dfn{derivations}. A derivation contains the
5012 following pieces of information:
5016 The outputs of the derivation---derivations produce at least one file or
5017 directory in the store, but may produce more.
5020 The inputs of the derivations, which may be other derivations or plain
5021 files in the store (patches, build scripts, etc.)
5024 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
5027 The file name of a build script in the store, along with the arguments
5031 A list of environment variables to be defined.
5035 @cindex derivation path
5036 Derivations allow clients of the daemon to communicate build actions to
5037 the store. They exist in two forms: as an in-memory representation,
5038 both on the client- and daemon-side, and as files in the store whose
5039 name end in @code{.drv}---these files are referred to as @dfn{derivation
5040 paths}. Derivations paths can be passed to the @code{build-derivations}
5041 procedure to perform the build actions they prescribe (@pxref{The
5044 @cindex fixed-output derivations
5045 Operations such as file downloads and version-control checkouts for
5046 which the expected content hash is known in advance are modeled as
5047 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
5048 of a fixed-output derivation are independent of its inputs---e.g., a
5049 source code download produces the same result regardless of the download
5050 method and tools being used.
5052 The @code{(guix derivations)} module provides a representation of
5053 derivations as Scheme objects, along with procedures to create and
5054 otherwise manipulate derivations. The lowest-level primitive to create
5055 a derivation is the @code{derivation} procedure:
5057 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
5058 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
5059 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
5060 [#:system (%current-system)] [#:references-graphs #f] @
5061 [#:allowed-references #f] [#:disallowed-references #f] @
5062 [#:leaked-env-vars #f] [#:local-build? #f] @
5063 [#:substitutable? #t]
5064 Build a derivation with the given arguments, and return the resulting
5065 @code{<derivation>} object.
5067 When @var{hash} and @var{hash-algo} are given, a
5068 @dfn{fixed-output derivation} is created---i.e., one whose result is
5069 known in advance, such as a file download. If, in addition,
5070 @var{recursive?} is true, then that fixed output may be an executable
5071 file or a directory and @var{hash} must be the hash of an archive
5072 containing this output.
5074 When @var{references-graphs} is true, it must be a list of file
5075 name/store path pairs. In that case, the reference graph of each store
5076 path is exported in the build environment in the corresponding file, in
5077 a simple text format.
5079 When @var{allowed-references} is true, it must be a list of store items
5080 or outputs that the derivation's output may refer to. Likewise,
5081 @var{disallowed-references}, if true, must be a list of things the
5082 outputs may @emph{not} refer to.
5084 When @var{leaked-env-vars} is true, it must be a list of strings
5085 denoting environment variables that are allowed to ``leak'' from the
5086 daemon's environment to the build environment. This is only applicable
5087 to fixed-output derivations---i.e., when @var{hash} is true. The main
5088 use is to allow variables such as @code{http_proxy} to be passed to
5089 derivations that download files.
5091 When @var{local-build?} is true, declare that the derivation is not a
5092 good candidate for offloading and should rather be built locally
5093 (@pxref{Daemon Offload Setup}). This is the case for small derivations
5094 where the costs of data transfers would outweigh the benefits.
5096 When @var{substitutable?} is false, declare that substitutes of the
5097 derivation's output should not be used (@pxref{Substitutes}). This is
5098 useful, for instance, when building packages that capture details of the
5099 host CPU instruction set.
5103 Here's an example with a shell script as its builder, assuming
5104 @var{store} is an open connection to the daemon, and @var{bash} points
5105 to a Bash executable in the store:
5108 (use-modules (guix utils)
5112 (let ((builder ; add the Bash script to the store
5113 (add-text-to-store store "my-builder.sh"
5114 "echo hello world > $out\n" '())))
5115 (derivation store "foo"
5116 bash `("-e" ,builder)
5117 #:inputs `((,bash) (,builder))
5118 #:env-vars '(("HOME" . "/homeless"))))
5119 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
5122 As can be guessed, this primitive is cumbersome to use directly. A
5123 better approach is to write build scripts in Scheme, of course! The
5124 best course of action for that is to write the build code as a
5125 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
5126 information, @pxref{G-Expressions}.
5128 Once upon a time, @code{gexp->derivation} did not exist and constructing
5129 derivations with build code written in Scheme was achieved with
5130 @code{build-expression->derivation}, documented below. This procedure
5131 is now deprecated in favor of the much nicer @code{gexp->derivation}.
5133 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
5134 @var{name} @var{exp} @
5135 [#:system (%current-system)] [#:inputs '()] @
5136 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
5137 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
5138 [#:references-graphs #f] [#:allowed-references #f] @
5139 [#:disallowed-references #f] @
5140 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
5141 Return a derivation that executes Scheme expression @var{exp} as a
5142 builder for derivation @var{name}. @var{inputs} must be a list of
5143 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
5144 @code{"out"} is assumed. @var{modules} is a list of names of Guile
5145 modules from the current search path to be copied in the store,
5146 compiled, and made available in the load path during the execution of
5147 @var{exp}---e.g., @code{((guix build utils) (guix build
5148 gnu-build-system))}.
5150 @var{exp} is evaluated in an environment where @code{%outputs} is bound
5151 to a list of output/path pairs, and where @code{%build-inputs} is bound
5152 to a list of string/output-path pairs made from @var{inputs}.
5153 Optionally, @var{env-vars} is a list of string pairs specifying the name
5154 and value of environment variables visible to the builder. The builder
5155 terminates by passing the result of @var{exp} to @code{exit}; thus, when
5156 @var{exp} returns @code{#f}, the build is considered to have failed.
5158 @var{exp} is built using @var{guile-for-build} (a derivation). When
5159 @var{guile-for-build} is omitted or is @code{#f}, the value of the
5160 @code{%guile-for-build} fluid is used instead.
5162 See the @code{derivation} procedure for the meaning of
5163 @var{references-graphs}, @var{allowed-references},
5164 @var{disallowed-references}, @var{local-build?}, and
5165 @var{substitutable?}.
5169 Here's an example of a single-output derivation that creates a directory
5170 containing one file:
5173 (let ((builder '(let ((out (assoc-ref %outputs "out")))
5174 (mkdir out) ; create /gnu/store/@dots{}-goo
5175 (call-with-output-file (string-append out "/test")
5177 (display '(hello guix) p))))))
5178 (build-expression->derivation store "goo" builder))
5180 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
5184 @node The Store Monad
5185 @section The Store Monad
5189 The procedures that operate on the store described in the previous
5190 sections all take an open connection to the build daemon as their first
5191 argument. Although the underlying model is functional, they either have
5192 side effects or depend on the current state of the store.
5194 The former is inconvenient: the connection to the build daemon has to be
5195 carried around in all those functions, making it impossible to compose
5196 functions that do not take that parameter with functions that do. The
5197 latter can be problematic: since store operations have side effects
5198 and/or depend on external state, they have to be properly sequenced.
5200 @cindex monadic values
5201 @cindex monadic functions
5202 This is where the @code{(guix monads)} module comes in. This module
5203 provides a framework for working with @dfn{monads}, and a particularly
5204 useful monad for our uses, the @dfn{store monad}. Monads are a
5205 construct that allows two things: associating ``context'' with values
5206 (in our case, the context is the store), and building sequences of
5207 computations (here computations include accesses to the store). Values
5208 in a monad---values that carry this additional context---are called
5209 @dfn{monadic values}; procedures that return such values are called
5210 @dfn{monadic procedures}.
5212 Consider this ``normal'' procedure:
5215 (define (sh-symlink store)
5216 ;; Return a derivation that symlinks the 'bash' executable.
5217 (let* ((drv (package-derivation store bash))
5218 (out (derivation->output-path drv))
5219 (sh (string-append out "/bin/bash")))
5220 (build-expression->derivation store "sh"
5221 `(symlink ,sh %output))))
5224 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
5225 as a monadic function:
5228 (define (sh-symlink)
5229 ;; Same, but return a monadic value.
5230 (mlet %store-monad ((drv (package->derivation bash)))
5231 (gexp->derivation "sh"
5232 #~(symlink (string-append #$drv "/bin/bash")
5236 There are several things to note in the second version: the @code{store}
5237 parameter is now implicit and is ``threaded'' in the calls to the
5238 @code{package->derivation} and @code{gexp->derivation} monadic
5239 procedures, and the monadic value returned by @code{package->derivation}
5240 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
5242 As it turns out, the call to @code{package->derivation} can even be
5243 omitted since it will take place implicitly, as we will see later
5244 (@pxref{G-Expressions}):
5247 (define (sh-symlink)
5248 (gexp->derivation "sh"
5249 #~(symlink (string-append #$bash "/bin/bash")
5254 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
5255 @c for the funny quote.
5256 Calling the monadic @code{sh-symlink} has no effect. As someone once
5257 said, ``you exit a monad like you exit a building on fire: by running''.
5258 So, to exit the monad and get the desired effect, one must use
5259 @code{run-with-store}:
5262 (run-with-store (open-connection) (sh-symlink))
5263 @result{} /gnu/store/...-sh-symlink
5266 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
5267 new ``meta-commands'' to make it easier to deal with monadic procedures:
5268 @code{run-in-store}, and @code{enter-store-monad}. The former is used
5269 to ``run'' a single monadic value through the store:
5272 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
5273 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
5276 The latter enters a recursive REPL, where all the return values are
5277 automatically run through the store:
5280 scheme@@(guile-user)> ,enter-store-monad
5281 store-monad@@(guile-user) [1]> (package->derivation hello)
5282 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
5283 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
5284 $3 = "/gnu/store/@dots{}-foo"
5285 store-monad@@(guile-user) [1]> ,q
5286 scheme@@(guile-user)>
5290 Note that non-monadic values cannot be returned in the
5291 @code{store-monad} REPL.
5293 The main syntactic forms to deal with monads in general are provided by
5294 the @code{(guix monads)} module and are described below.
5296 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
5297 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
5301 @deffn {Scheme Syntax} return @var{val}
5302 Return a monadic value that encapsulates @var{val}.
5305 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
5306 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
5307 procedures @var{mproc}@dots{}@footnote{This operation is commonly
5308 referred to as ``bind'', but that name denotes an unrelated procedure in
5309 Guile. Thus we use this somewhat cryptic symbol inherited from the
5310 Haskell language.}. There can be one @var{mproc} or several of them, as
5315 (with-monad %state-monad
5317 (lambda (x) (return (+ 1 x)))
5318 (lambda (x) (return (* 2 x)))))
5322 @result{} some-state
5326 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
5328 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
5330 Bind the variables @var{var} to the monadic values @var{mval} in
5331 @var{body}, which is a sequence of expressions. As with the bind
5332 operator, this can be thought of as ``unpacking'' the raw, non-monadic
5333 value ``contained'' in @var{mval} and making @var{var} refer to that
5334 raw, non-monadic value within the scope of the @var{body}. The form
5335 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
5336 @var{val}, as per @code{let}. The binding operations occur in sequence
5337 from left to right. The last expression of @var{body} must be a monadic
5338 expression, and its result will become the result of the @code{mlet} or
5339 @code{mlet*} when run in the @var{monad}.
5341 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
5342 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
5345 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
5346 Bind @var{mexp} and the following monadic expressions in sequence,
5347 returning the result of the last expression. Every expression in the
5348 sequence must be a monadic expression.
5350 This is akin to @code{mlet}, except that the return values of the
5351 monadic expressions are ignored. In that sense, it is analogous to
5352 @code{begin}, but applied to monadic expressions.
5355 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
5356 When @var{condition} is true, evaluate the sequence of monadic
5357 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
5358 @var{condition} is false, return @code{*unspecified*} in the current
5359 monad. Every expression in the sequence must be a monadic expression.
5362 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
5363 When @var{condition} is false, evaluate the sequence of monadic
5364 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
5365 @var{condition} is true, return @code{*unspecified*} in the current
5366 monad. Every expression in the sequence must be a monadic expression.
5370 The @code{(guix monads)} module provides the @dfn{state monad}, which
5371 allows an additional value---the state---to be @emph{threaded} through
5372 monadic procedure calls.
5374 @defvr {Scheme Variable} %state-monad
5375 The state monad. Procedures in the state monad can access and change
5376 the state that is threaded.
5378 Consider the example below. The @code{square} procedure returns a value
5379 in the state monad. It returns the square of its argument, but also
5380 increments the current state value:
5384 (mlet %state-monad ((count (current-state)))
5385 (mbegin %state-monad
5386 (set-current-state (+ 1 count))
5389 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
5394 When ``run'' through @var{%state-monad}, we obtain that additional state
5395 value, which is the number of @code{square} calls.
5398 @deffn {Monadic Procedure} current-state
5399 Return the current state as a monadic value.
5402 @deffn {Monadic Procedure} set-current-state @var{value}
5403 Set the current state to @var{value} and return the previous state as a
5407 @deffn {Monadic Procedure} state-push @var{value}
5408 Push @var{value} to the current state, which is assumed to be a list,
5409 and return the previous state as a monadic value.
5412 @deffn {Monadic Procedure} state-pop
5413 Pop a value from the current state and return it as a monadic value.
5414 The state is assumed to be a list.
5417 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
5418 Run monadic value @var{mval} starting with @var{state} as the initial
5419 state. Return two values: the resulting value, and the resulting state.
5422 The main interface to the store monad, provided by the @code{(guix
5423 store)} module, is as follows.
5425 @defvr {Scheme Variable} %store-monad
5426 The store monad---an alias for @var{%state-monad}.
5428 Values in the store monad encapsulate accesses to the store. When its
5429 effect is needed, a value of the store monad must be ``evaluated'' by
5430 passing it to the @code{run-with-store} procedure (see below.)
5433 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
5434 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
5435 open store connection.
5438 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
5439 Return as a monadic value the absolute file name in the store of the file
5440 containing @var{text}, a string. @var{references} is a list of store items that the
5441 resulting text file refers to; it defaults to the empty list.
5444 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
5445 Return as a monadic value the absolute file name in the store of the file
5446 containing @var{data}, a bytevector. @var{references} is a list of store
5447 items that the resulting binary file refers to; it defaults to the empty list.
5450 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
5451 [#:recursive? #t] [#:select? (const #t)]
5452 Return the name of @var{file} once interned in the store. Use
5453 @var{name} as its store name, or the basename of @var{file} if
5454 @var{name} is omitted.
5456 When @var{recursive?} is true, the contents of @var{file} are added
5457 recursively; if @var{file} designates a flat file and @var{recursive?}
5458 is true, its contents are added, and its permission bits are kept.
5460 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
5461 @var{stat})} for each directory entry, where @var{file} is the entry's
5462 absolute file name and @var{stat} is the result of @code{lstat}; exclude
5463 entries for which @var{select?} does not return true.
5465 The example below adds a file to the store, under two different names:
5468 (run-with-store (open-connection)
5469 (mlet %store-monad ((a (interned-file "README"))
5470 (b (interned-file "README" "LEGU-MIN")))
5471 (return (list a b))))
5473 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
5478 The @code{(guix packages)} module exports the following package-related
5481 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
5482 [#:system (%current-system)] [#:target #f] @
5485 value in the absolute file name of @var{file} within the @var{output}
5486 directory of @var{package}. When @var{file} is omitted, return the name
5487 of the @var{output} directory of @var{package}. When @var{target} is
5488 true, use it as a cross-compilation target triplet.
5491 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
5492 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
5493 @var{target} [@var{system}]
5494 Monadic version of @code{package-derivation} and
5495 @code{package-cross-derivation} (@pxref{Defining Packages}).
5500 @section G-Expressions
5502 @cindex G-expression
5503 @cindex build code quoting
5504 So we have ``derivations'', which represent a sequence of build actions
5505 to be performed to produce an item in the store (@pxref{Derivations}).
5506 These build actions are performed when asking the daemon to actually
5507 build the derivations; they are run by the daemon in a container
5508 (@pxref{Invoking guix-daemon}).
5510 @cindex strata of code
5511 It should come as no surprise that we like to write these build actions
5512 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
5513 code@footnote{The term @dfn{stratum} in this context was coined by
5514 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
5515 Kiselyov, who has written insightful
5516 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
5517 on this topic}, refers to this kind of code generation as
5518 @dfn{staging}.}: the ``host code''---code that defines packages, talks
5519 to the daemon, etc.---and the ``build code''---code that actually
5520 performs build actions, such as making directories, invoking
5521 @command{make}, etc.
5523 To describe a derivation and its build actions, one typically needs to
5524 embed build code inside host code. It boils down to manipulating build
5525 code as data, and the homoiconicity of Scheme---code has a direct
5526 representation as data---comes in handy for that. But we need more than
5527 the normal @code{quasiquote} mechanism in Scheme to construct build
5530 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
5531 S-expressions adapted to build expressions. G-expressions, or
5532 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
5533 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
5534 @code{#$}, and @code{#$@@}), which are comparable to
5535 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
5536 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
5537 GNU Guile Reference Manual}). However, there are major differences:
5541 Gexps are meant to be written to a file and run or manipulated by other
5545 When a high-level object such as a package or derivation is unquoted
5546 inside a gexp, the result is as if its output file name had been
5550 Gexps carry information about the packages or derivations they refer to,
5551 and these dependencies are automatically added as inputs to the build
5552 processes that use them.
5555 @cindex lowering, of high-level objects in gexps
5556 This mechanism is not limited to package and derivation
5557 objects: @dfn{compilers} able to ``lower'' other high-level objects to
5558 derivations or files in the store can be defined,
5559 such that these objects can also be inserted
5560 into gexps. For example, a useful type of high-level objects that can be
5561 inserted in a gexp is ``file-like objects'', which make it easy to
5562 add files to the store and to refer to them in
5563 derivations and such (see @code{local-file} and @code{plain-file}
5566 To illustrate the idea, here is an example of a gexp:
5573 (symlink (string-append #$coreutils "/bin/ls")
5577 This gexp can be passed to @code{gexp->derivation}; we obtain a
5578 derivation that builds a directory containing exactly one symlink to
5579 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
5582 (gexp->derivation "the-thing" build-exp)
5585 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
5586 substituted to the reference to the @var{coreutils} package in the
5587 actual build code, and @var{coreutils} is automatically made an input to
5588 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
5589 output)}) is replaced by a string containing the directory name of the
5590 output of the derivation.
5592 @cindex cross compilation
5593 In a cross-compilation context, it is useful to distinguish between
5594 references to the @emph{native} build of a package---that can run on the
5595 host---versus references to cross builds of a package. To that end, the
5596 @code{#+} plays the same role as @code{#$}, but is a reference to a
5597 native package build:
5600 (gexp->derivation "vi"
5603 (system* (string-append #+coreutils "/bin/ln")
5605 (string-append #$emacs "/bin/emacs")
5606 (string-append #$output "/bin/vi")))
5607 #:target "mips64el-linux-gnu")
5611 In the example above, the native build of @var{coreutils} is used, so
5612 that @command{ln} can actually run on the host; but then the
5613 cross-compiled build of @var{emacs} is referenced.
5615 @cindex imported modules, for gexps
5616 @findex with-imported-modules
5617 Another gexp feature is @dfn{imported modules}: sometimes you want to be
5618 able to use certain Guile modules from the ``host environment'' in the
5619 gexp, so those modules should be imported in the ``build environment''.
5620 The @code{with-imported-modules} form allows you to express that:
5623 (let ((build (with-imported-modules '((guix build utils))
5625 (use-modules (guix build utils))
5626 (mkdir-p (string-append #$output "/bin"))))))
5627 (gexp->derivation "empty-dir"
5630 (display "success!\n")
5635 In this example, the @code{(guix build utils)} module is automatically
5636 pulled into the isolated build environment of our gexp, such that
5637 @code{(use-modules (guix build utils))} works as expected.
5639 @cindex module closure
5640 @findex source-module-closure
5641 Usually you want the @emph{closure} of the module to be imported---i.e.,
5642 the module itself and all the modules it depends on---rather than just
5643 the module; failing to do that, attempts to use the module will fail
5644 because of missing dependent modules. The @code{source-module-closure}
5645 procedure computes the closure of a module by looking at its source file
5646 headers, which comes in handy in this case:
5649 (use-modules (guix modules)) ;for 'source-module-closure'
5651 (with-imported-modules (source-module-closure
5652 '((guix build utils)
5654 (gexp->derivation "something-with-vms"
5656 (use-modules (guix build utils)
5661 @cindex extensions, for gexps
5662 @findex with-extensions
5663 In the same vein, sometimes you want to import not just pure-Scheme
5664 modules, but also ``extensions'' such as Guile bindings to C libraries
5665 or other ``full-blown'' packages. Say you need the @code{guile-json}
5666 package available on the build side, here's how you would do it:
5669 (use-modules (gnu packages guile)) ;for 'guile-json'
5671 (with-extensions (list guile-json)
5672 (gexp->derivation "something-with-json"
5674 (use-modules (json))
5678 The syntactic form to construct gexps is summarized below.
5680 @deffn {Scheme Syntax} #~@var{exp}
5681 @deffnx {Scheme Syntax} (gexp @var{exp})
5682 Return a G-expression containing @var{exp}. @var{exp} may contain one
5683 or more of the following forms:
5687 @itemx (ungexp @var{obj})
5688 Introduce a reference to @var{obj}. @var{obj} may have one of the
5689 supported types, for example a package or a
5690 derivation, in which case the @code{ungexp} form is replaced by its
5691 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
5693 If @var{obj} is a list, it is traversed and references to supported
5694 objects are substituted similarly.
5696 If @var{obj} is another gexp, its contents are inserted and its
5697 dependencies are added to those of the containing gexp.
5699 If @var{obj} is another kind of object, it is inserted as is.
5701 @item #$@var{obj}:@var{output}
5702 @itemx (ungexp @var{obj} @var{output})
5703 This is like the form above, but referring explicitly to the
5704 @var{output} of @var{obj}---this is useful when @var{obj} produces
5705 multiple outputs (@pxref{Packages with Multiple Outputs}).
5708 @itemx #+@var{obj}:output
5709 @itemx (ungexp-native @var{obj})
5710 @itemx (ungexp-native @var{obj} @var{output})
5711 Same as @code{ungexp}, but produces a reference to the @emph{native}
5712 build of @var{obj} when used in a cross compilation context.
5714 @item #$output[:@var{output}]
5715 @itemx (ungexp output [@var{output}])
5716 Insert a reference to derivation output @var{output}, or to the main
5717 output when @var{output} is omitted.
5719 This only makes sense for gexps passed to @code{gexp->derivation}.
5722 @itemx (ungexp-splicing @var{lst})
5723 Like the above, but splices the contents of @var{lst} inside the
5727 @itemx (ungexp-native-splicing @var{lst})
5728 Like the above, but refers to native builds of the objects listed in
5733 G-expressions created by @code{gexp} or @code{#~} are run-time objects
5734 of the @code{gexp?} type (see below.)
5737 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
5738 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
5739 in their execution environment.
5741 Each item in @var{modules} can be the name of a module, such as
5742 @code{(guix build utils)}, or it can be a module name, followed by an
5743 arrow, followed by a file-like object:
5746 `((guix build utils)
5748 ((guix config) => ,(scheme-file "config.scm"
5749 #~(define-module @dots{}))))
5753 In the example above, the first two modules are taken from the search
5754 path, and the last one is created from the given file-like object.
5756 This form has @emph{lexical} scope: it has an effect on the gexps
5757 directly defined in @var{body}@dots{}, but not on those defined, say, in
5758 procedures called from @var{body}@dots{}.
5761 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
5762 Mark the gexps defined in @var{body}@dots{} as requiring
5763 @var{extensions} in their build and execution environment.
5764 @var{extensions} is typically a list of package objects such as those
5765 defined in the @code{(gnu packages guile)} module.
5767 Concretely, the packages listed in @var{extensions} are added to the
5768 load path while compiling imported modules in @var{body}@dots{}; they
5769 are also added to the load path of the gexp returned by
5773 @deffn {Scheme Procedure} gexp? @var{obj}
5774 Return @code{#t} if @var{obj} is a G-expression.
5777 G-expressions are meant to be written to disk, either as code building
5778 some derivation, or as plain files in the store. The monadic procedures
5779 below allow you to do that (@pxref{The Store Monad}, for more
5780 information about monads.)
5782 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
5783 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
5784 [#:hash #f] [#:hash-algo #f] @
5785 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
5786 [#:module-path @var{%load-path}] @
5787 [#:effective-version "2.2"] @
5788 [#:references-graphs #f] [#:allowed-references #f] @
5789 [#:disallowed-references #f] @
5790 [#:leaked-env-vars #f] @
5791 [#:script-name (string-append @var{name} "-builder")] @
5792 [#:deprecation-warnings #f] @
5793 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
5794 Return a derivation @var{name} that runs @var{exp} (a gexp) with
5795 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
5796 stored in a file called @var{script-name}. When @var{target} is true,
5797 it is used as the cross-compilation target triplet for packages referred
5800 @var{modules} is deprecated in favor of @code{with-imported-modules}.
5802 make @var{modules} available in the evaluation context of @var{exp};
5803 @var{modules} is a list of names of Guile modules searched in
5804 @var{module-path} to be copied in the store, compiled, and made available in
5805 the load path during the execution of @var{exp}---e.g., @code{((guix
5806 build utils) (guix build gnu-build-system))}.
5808 @var{effective-version} determines the string to use when adding extensions of
5809 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
5811 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
5814 When @var{references-graphs} is true, it must be a list of tuples of one of the
5818 (@var{file-name} @var{package})
5819 (@var{file-name} @var{package} @var{output})
5820 (@var{file-name} @var{derivation})
5821 (@var{file-name} @var{derivation} @var{output})
5822 (@var{file-name} @var{store-item})
5825 The right-hand-side of each element of @var{references-graphs} is automatically made
5826 an input of the build process of @var{exp}. In the build environment, each
5827 @var{file-name} contains the reference graph of the corresponding item, in a simple
5830 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
5831 In the latter case, the list denotes store items that the result is allowed to
5832 refer to. Any reference to another store item will lead to a build error.
5833 Similarly for @var{disallowed-references}, which can list items that must not be
5834 referenced by the outputs.
5836 @var{deprecation-warnings} determines whether to show deprecation warnings while
5837 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
5839 The other arguments are as for @code{derivation} (@pxref{Derivations}).
5842 @cindex file-like objects
5843 The @code{local-file}, @code{plain-file}, @code{computed-file},
5844 @code{program-file}, and @code{scheme-file} procedures below return
5845 @dfn{file-like objects}. That is, when unquoted in a G-expression,
5846 these objects lead to a file in the store. Consider this G-expression:
5849 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
5850 #$(local-file "/tmp/my-nscd.conf"))
5853 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
5854 to the store. Once expanded, for instance @i{via}
5855 @code{gexp->derivation}, the G-expression refers to that copy under
5856 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
5857 does not have any effect on what the G-expression does.
5858 @code{plain-file} can be used similarly; it differs in that the file
5859 content is directly passed as a string.
5861 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
5862 [#:recursive? #f] [#:select? (const #t)]
5863 Return an object representing local file @var{file} to add to the store; this
5864 object can be used in a gexp. If @var{file} is a relative file name, it is looked
5865 up relative to the source file where this form appears. @var{file} will be added to
5866 the store under @var{name}--by default the base name of @var{file}.
5868 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
5869 designates a flat file and @var{recursive?} is true, its contents are added, and its
5870 permission bits are kept.
5872 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
5873 @var{stat})} for each directory entry, where @var{file} is the entry's
5874 absolute file name and @var{stat} is the result of @code{lstat}; exclude
5875 entries for which @var{select?} does not return true.
5877 This is the declarative counterpart of the @code{interned-file} monadic
5878 procedure (@pxref{The Store Monad, @code{interned-file}}).
5881 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
5882 Return an object representing a text file called @var{name} with the given
5883 @var{content} (a string or a bytevector) to be added to the store.
5885 This is the declarative counterpart of @code{text-file}.
5888 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
5889 [#:options '(#:local-build? #t)]
5890 Return an object representing the store item @var{name}, a file or
5891 directory computed by @var{gexp}. @var{options}
5892 is a list of additional arguments to pass to @code{gexp->derivation}.
5894 This is the declarative counterpart of @code{gexp->derivation}.
5897 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
5898 [#:guile (default-guile)] [#:module-path %load-path]
5899 Return an executable script @var{name} that runs @var{exp} using
5900 @var{guile}, with @var{exp}'s imported modules in its search path.
5901 Look up @var{exp}'s modules in @var{module-path}.
5903 The example below builds a script that simply invokes the @command{ls}
5907 (use-modules (guix gexp) (gnu packages base))
5909 (gexp->script "list-files"
5910 #~(execl #$(file-append coreutils "/bin/ls")
5914 When ``running'' it through the store (@pxref{The Store Monad,
5915 @code{run-with-store}}), we obtain a derivation that produces an
5916 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
5919 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
5921 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
5925 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
5926 [#:guile #f] [#:module-path %load-path]
5927 Return an object representing the executable store item @var{name} that
5928 runs @var{gexp}. @var{guile} is the Guile package used to execute that
5929 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
5931 This is the declarative counterpart of @code{gexp->script}.
5934 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
5935 [#:set-load-path? #t] [#:module-path %load-path] @
5937 [#:guile (default-guile)]
5938 Return a derivation that builds a file @var{name} containing @var{exp}.
5939 When @var{splice?} is true, @var{exp} is considered to be a list of
5940 expressions that will be spliced in the resulting file.
5942 When @var{set-load-path?} is true, emit code in the resulting file to
5943 set @code{%load-path} and @code{%load-compiled-path} to honor
5944 @var{exp}'s imported modules. Look up @var{exp}'s modules in
5947 The resulting file holds references to all the dependencies of @var{exp}
5948 or a subset thereof.
5951 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
5952 Return an object representing the Scheme file @var{name} that contains
5955 This is the declarative counterpart of @code{gexp->file}.
5958 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
5959 Return as a monadic value a derivation that builds a text file
5960 containing all of @var{text}. @var{text} may list, in addition to
5961 strings, objects of any type that can be used in a gexp: packages,
5962 derivations, local file objects, etc. The resulting store file holds
5963 references to all these.
5965 This variant should be preferred over @code{text-file} anytime the file
5966 to create will reference items from the store. This is typically the
5967 case when building a configuration file that embeds store file names,
5971 (define (profile.sh)
5972 ;; Return the name of a shell script in the store that
5973 ;; initializes the 'PATH' environment variable.
5974 (text-file* "profile.sh"
5975 "export PATH=" coreutils "/bin:"
5976 grep "/bin:" sed "/bin\n"))
5979 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
5980 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
5981 preventing them from being garbage-collected during its lifetime.
5984 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
5985 Return an object representing store file @var{name} containing
5986 @var{text}. @var{text} is a sequence of strings and file-like objects,
5990 (mixed-text-file "profile"
5991 "export PATH=" coreutils "/bin:" grep "/bin")
5994 This is the declarative counterpart of @code{text-file*}.
5997 @deffn {Scheme Procedure} file-union @var{name} @var{files}
5998 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
5999 Each item in @var{files} must be a two-element list where the first element is the
6000 file name to use in the new directory, and the second element is a gexp
6001 denoting the target file. Here's an example:
6005 `(("hosts" ,(plain-file "hosts"
6006 "127.0.0.1 localhost"))
6007 ("bashrc" ,(plain-file "bashrc"
6008 "alias ls='ls --color=auto'"))))
6011 This yields an @code{etc} directory containing these two files.
6014 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
6015 Return a directory that is the union of @var{things}, where @var{things} is a list of
6016 file-like objects denoting directories. For example:
6019 (directory-union "guile+emacs" (list guile emacs))
6022 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
6025 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
6026 Return a file-like object that expands to the concatenation of @var{obj}
6027 and @var{suffix}, where @var{obj} is a lowerable object and each
6028 @var{suffix} is a string.
6030 As an example, consider this gexp:
6033 (gexp->script "run-uname"
6034 #~(system* #$(file-append coreutils
6038 The same effect could be achieved with:
6041 (gexp->script "run-uname"
6042 #~(system* (string-append #$coreutils
6046 There is one difference though: in the @code{file-append} case, the
6047 resulting script contains the absolute file name as a string, whereas in
6048 the second case, the resulting script contains a @code{(string-append
6049 @dots{})} expression to construct the file name @emph{at run time}.
6053 Of course, in addition to gexps embedded in ``host'' code, there are
6054 also modules containing build tools. To make it clear that they are
6055 meant to be used in the build stratum, these modules are kept in the
6056 @code{(guix build @dots{})} name space.
6058 @cindex lowering, of high-level objects in gexps
6059 Internally, high-level objects are @dfn{lowered}, using their compiler,
6060 to either derivations or store items. For instance, lowering a package
6061 yields a derivation, and lowering a @code{plain-file} yields a store
6062 item. This is achieved using the @code{lower-object} monadic procedure.
6064 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
6066 Return as a value in @var{%store-monad} the derivation or store item
6067 corresponding to @var{obj} for @var{system}, cross-compiling for
6068 @var{target} if @var{target} is true. @var{obj} must be an object that
6069 has an associated gexp compiler, such as a @code{<package>}.
6072 @node Invoking guix repl
6073 @section Invoking @command{guix repl}
6075 @cindex REPL, read-eval-print loop
6076 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
6077 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
6078 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
6079 command, @command{guix repl} guarantees that all the Guix modules and all its
6080 dependencies are available in the search path. You can use it this way:
6084 scheme@@(guile-user)> ,use (gnu packages base)
6085 scheme@@(guile-user)> coreutils
6086 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
6090 In addition, @command{guix repl} implements a simple machine-readable REPL
6091 protocol for use by @code{(guix inferior)}, a facility to interact with
6092 @dfn{inferiors}, separate processes running a potentially different revision
6095 The available options are as follows:
6098 @item --type=@var{type}
6099 @itemx -t @var{type}
6100 Start a REPL of the given @var{TYPE}, which can be one of the following:
6104 This is default, and it spawns a standard full-featured Guile REPL.
6106 Spawn a REPL that uses the machine-readable protocol. This is the protocol
6107 that the @code{(guix inferior)} module speaks.
6110 @item --listen=@var{endpoint}
6111 By default, @command{guix repl} reads from standard input and writes to
6112 standard output. When this option is passed, it will instead listen for
6113 connections on @var{endpoint}. Here are examples of valid options:
6116 @item --listen=tcp:37146
6117 Accept connections on localhost on port 37146.
6119 @item --listen=unix:/tmp/socket
6120 Accept connections on the Unix-domain socket @file{/tmp/socket}.
6124 @c *********************************************************************
6128 This section describes Guix command-line utilities. Some of them are
6129 primarily targeted at developers and users who write new package
6130 definitions, while others are more generally useful. They complement
6131 the Scheme programming interface of Guix in a convenient way.
6134 * Invoking guix build:: Building packages from the command line.
6135 * Invoking guix edit:: Editing package definitions.
6136 * Invoking guix download:: Downloading a file and printing its hash.
6137 * Invoking guix hash:: Computing the cryptographic hash of a file.
6138 * Invoking guix import:: Importing package definitions.
6139 * Invoking guix refresh:: Updating package definitions.
6140 * Invoking guix lint:: Finding errors in package definitions.
6141 * Invoking guix size:: Profiling disk usage.
6142 * Invoking guix graph:: Visualizing the graph of packages.
6143 * Invoking guix environment:: Setting up development environments.
6144 * Invoking guix publish:: Sharing substitutes.
6145 * Invoking guix challenge:: Challenging substitute servers.
6146 * Invoking guix copy:: Copying to and from a remote store.
6147 * Invoking guix container:: Process isolation.
6148 * Invoking guix weather:: Assessing substitute availability.
6149 * Invoking guix processes:: Listing client processes.
6152 @node Invoking guix build
6153 @section Invoking @command{guix build}
6155 @cindex package building
6156 @cindex @command{guix build}
6157 The @command{guix build} command builds packages or derivations and
6158 their dependencies, and prints the resulting store paths. Note that it
6159 does not modify the user's profile---this is the job of the
6160 @command{guix package} command (@pxref{Invoking guix package}). Thus,
6161 it is mainly useful for distribution developers.
6163 The general syntax is:
6166 guix build @var{options} @var{package-or-derivation}@dots{}
6169 As an example, the following command builds the latest versions of Emacs
6170 and of Guile, displays their build logs, and finally displays the
6171 resulting directories:
6174 guix build emacs guile
6177 Similarly, the following command builds all the available packages:
6180 guix build --quiet --keep-going \
6181 `guix package -A | cut -f1,2 --output-delimiter=@@`
6184 @var{package-or-derivation} may be either the name of a package found in
6185 the software distribution such as @code{coreutils} or
6186 @code{coreutils@@8.20}, or a derivation such as
6187 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
6188 package with the corresponding name (and optionally version) is searched
6189 for among the GNU distribution modules (@pxref{Package Modules}).
6191 Alternatively, the @code{--expression} option may be used to specify a
6192 Scheme expression that evaluates to a package; this is useful when
6193 disambiguating among several same-named packages or package variants is
6196 There may be zero or more @var{options}. The available options are
6197 described in the subsections below.
6200 * Common Build Options:: Build options for most commands.
6201 * Package Transformation Options:: Creating variants of packages.
6202 * Additional Build Options:: Options specific to 'guix build'.
6203 * Debugging Build Failures:: Real life packaging experience.
6206 @node Common Build Options
6207 @subsection Common Build Options
6209 A number of options that control the build process are common to
6210 @command{guix build} and other commands that can spawn builds, such as
6211 @command{guix package} or @command{guix archive}. These are the
6216 @item --load-path=@var{directory}
6217 @itemx -L @var{directory}
6218 Add @var{directory} to the front of the package module search path
6219 (@pxref{Package Modules}).
6221 This allows users to define their own packages and make them visible to
6222 the command-line tools.
6226 Keep the build tree of failed builds. Thus, if a build fails, its build
6227 tree is kept under @file{/tmp}, in a directory whose name is shown at
6228 the end of the build log. This is useful when debugging build issues.
6229 @xref{Debugging Build Failures}, for tips and tricks on how to debug
6232 This option has no effect when connecting to a remote daemon with a
6233 @code{guix://} URI (@pxref{The Store, the @code{GUIX_DAEMON_SOCKET}
6238 Keep going when some of the derivations fail to build; return only once
6239 all the builds have either completed or failed.
6241 The default behavior is to stop as soon as one of the specified
6242 derivations has failed.
6246 Do not build the derivations.
6248 @anchor{fallback-option}
6250 When substituting a pre-built binary fails, fall back to building
6251 packages locally (@pxref{Substitution Failure}).
6253 @item --substitute-urls=@var{urls}
6254 @anchor{client-substitute-urls}
6255 Consider @var{urls} the whitespace-separated list of substitute source
6256 URLs, overriding the default list of URLs of @command{guix-daemon}
6257 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
6259 This means that substitutes may be downloaded from @var{urls}, provided
6260 they are signed by a key authorized by the system administrator
6261 (@pxref{Substitutes}).
6263 When @var{urls} is the empty string, substitutes are effectively
6266 @item --no-substitutes
6267 Do not use substitutes for build products. That is, always build things
6268 locally instead of allowing downloads of pre-built binaries
6269 (@pxref{Substitutes}).
6272 Do not ``graft'' packages. In practice, this means that package updates
6273 available as grafts are not applied. @xref{Security Updates}, for more
6274 information on grafts.
6276 @item --rounds=@var{n}
6277 Build each derivation @var{n} times in a row, and raise an error if
6278 consecutive build results are not bit-for-bit identical.
6280 This is a useful way to detect non-deterministic builds processes.
6281 Non-deterministic build processes are a problem because they make it
6282 practically impossible for users to @emph{verify} whether third-party
6283 binaries are genuine. @xref{Invoking guix challenge}, for more.
6285 Note that, currently, the differing build results are not kept around,
6286 so you will have to manually investigate in case of an error---e.g., by
6287 stashing one of the build results with @code{guix archive --export}
6288 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
6291 @item --no-build-hook
6292 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
6293 (@pxref{Daemon Offload Setup}). That is, always build things locally
6294 instead of offloading builds to remote machines.
6296 @item --max-silent-time=@var{seconds}
6297 When the build or substitution process remains silent for more than
6298 @var{seconds}, terminate it and report a build failure.
6300 By default, the daemon's setting is honored (@pxref{Invoking
6301 guix-daemon, @code{--max-silent-time}}).
6303 @item --timeout=@var{seconds}
6304 Likewise, when the build or substitution process lasts for more than
6305 @var{seconds}, terminate it and report a build failure.
6307 By default, the daemon's setting is honored (@pxref{Invoking
6308 guix-daemon, @code{--timeout}}).
6310 @item --verbosity=@var{level}
6311 Use the given verbosity level. @var{level} must be an integer between 0
6312 and 5; higher means more verbose output. Setting a level of 4 or more
6313 may be helpful when debugging setup issues with the build daemon.
6315 @item --cores=@var{n}
6317 Allow the use of up to @var{n} CPU cores for the build. The special
6318 value @code{0} means to use as many CPU cores as available.
6320 @item --max-jobs=@var{n}
6322 Allow at most @var{n} build jobs in parallel. @xref{Invoking
6323 guix-daemon, @code{--max-jobs}}, for details about this option and the
6324 equivalent @command{guix-daemon} option.
6328 Behind the scenes, @command{guix build} is essentially an interface to
6329 the @code{package-derivation} procedure of the @code{(guix packages)}
6330 module, and to the @code{build-derivations} procedure of the @code{(guix
6331 derivations)} module.
6333 In addition to options explicitly passed on the command line,
6334 @command{guix build} and other @command{guix} commands that support
6335 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
6337 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
6338 Users can define this variable to a list of command line options that
6339 will automatically be used by @command{guix build} and other
6340 @command{guix} commands that can perform builds, as in the example
6344 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
6347 These options are parsed independently, and the result is appended to
6348 the parsed command-line options.
6352 @node Package Transformation Options
6353 @subsection Package Transformation Options
6355 @cindex package variants
6356 Another set of command-line options supported by @command{guix build}
6357 and also @command{guix package} are @dfn{package transformation
6358 options}. These are options that make it possible to define @dfn{package
6359 variants}---for instance, packages built from different source code.
6360 This is a convenient way to create customized packages on the fly
6361 without having to type in the definitions of package variants
6362 (@pxref{Defining Packages}).
6366 @item --with-source=@var{source}
6367 @itemx --with-source=@var{package}=@var{source}
6368 @itemx --with-source=@var{package}@@@var{version}=@var{source}
6369 Use @var{source} as the source of @var{package}, and @var{version} as
6371 @var{source} must be a file name or a URL, as for @command{guix
6372 download} (@pxref{Invoking guix download}).
6374 When @var{package} is omitted,
6375 it is taken to be the package name specified on the
6376 command line that matches the base of @var{source}---e.g.,
6377 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
6378 package is @code{guile}.
6380 Likewise, when @var{version} is omitted, the version string is inferred from
6381 @var{source}; in the previous example, it is @code{2.0.10}.
6383 This option allows users to try out versions of packages other than the
6384 one provided by the distribution. The example below downloads
6385 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
6386 the @code{ed} package:
6389 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
6392 As a developer, @code{--with-source} makes it easy to test release
6396 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
6399 @dots{} or to build from a checkout in a pristine environment:
6402 $ git clone git://git.sv.gnu.org/guix.git
6403 $ guix build guix --with-source=guix@@1.0=./guix
6406 @item --with-input=@var{package}=@var{replacement}
6407 Replace dependency on @var{package} by a dependency on
6408 @var{replacement}. @var{package} must be a package name, and
6409 @var{replacement} must be a package specification such as @code{guile}
6410 or @code{guile@@1.8}.
6412 For instance, the following command builds Guix, but replaces its
6413 dependency on the current stable version of Guile with a dependency on
6414 the legacy version of Guile, @code{guile@@2.0}:
6417 guix build --with-input=guile=guile@@2.0 guix
6420 This is a recursive, deep replacement. So in this example, both
6421 @code{guix} and its dependency @code{guile-json} (which also depends on
6422 @code{guile}) get rebuilt against @code{guile@@2.0}.
6424 This is implemented using the @code{package-input-rewriting} Scheme
6425 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
6427 @item --with-graft=@var{package}=@var{replacement}
6428 This is similar to @code{--with-input} but with an important difference:
6429 instead of rebuilding the whole dependency chain, @var{replacement} is
6430 built and then @dfn{grafted} onto the binaries that were initially
6431 referring to @var{package}. @xref{Security Updates}, for more
6432 information on grafts.
6434 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
6435 and all its dependencies, replacing references to the version of GnuTLS
6436 they currently refer to:
6439 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
6442 This has the advantage of being much faster than rebuilding everything.
6443 But there is a caveat: it works if and only if @var{package} and
6444 @var{replacement} are strictly compatible---for example, if they provide
6445 a library, the application binary interface (ABI) of those libraries
6446 must be compatible. If @var{replacement} is somehow incompatible with
6447 @var{package}, then the resulting package may be unusable. Use with
6452 @node Additional Build Options
6453 @subsection Additional Build Options
6455 The command-line options presented below are specific to @command{guix
6462 Build quietly, without displaying the build log. Upon completion, the
6463 build log is kept in @file{/var} (or similar) and can always be
6464 retrieved using the @option{--log-file} option.
6466 @item --file=@var{file}
6467 @itemx -f @var{file}
6468 Build the package, derivation, or other file-like object that the code within
6469 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
6471 As an example, @var{file} might contain a package definition like this
6472 (@pxref{Defining Packages}):
6475 @verbatiminclude package-hello.scm
6478 @item --expression=@var{expr}
6479 @itemx -e @var{expr}
6480 Build the package or derivation @var{expr} evaluates to.
6482 For example, @var{expr} may be @code{(@@ (gnu packages guile)
6483 guile-1.8)}, which unambiguously designates this specific variant of
6484 version 1.8 of Guile.
6486 Alternatively, @var{expr} may be a G-expression, in which case it is used
6487 as a build program passed to @code{gexp->derivation}
6488 (@pxref{G-Expressions}).
6490 Lastly, @var{expr} may refer to a zero-argument monadic procedure
6491 (@pxref{The Store Monad}). The procedure must return a derivation as a
6492 monadic value, which is then passed through @code{run-with-store}.
6496 Build the source derivations of the packages, rather than the packages
6499 For instance, @code{guix build -S gcc} returns something like
6500 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
6503 The returned source tarball is the result of applying any patches and
6504 code snippets specified in the package @code{origin} (@pxref{Defining
6508 Fetch and return the source of @var{package-or-derivation} and all their
6509 dependencies, recursively. This is a handy way to obtain a local copy
6510 of all the source code needed to build @var{packages}, allowing you to
6511 eventually build them even without network access. It is an extension
6512 of the @code{--source} option and can accept one of the following
6513 optional argument values:
6517 This value causes the @code{--sources} option to behave in the same way
6518 as the @code{--source} option.
6521 Build the source derivations of all packages, including any source that
6522 might be listed as @code{inputs}. This is the default value.
6525 $ guix build --sources tzdata
6526 The following derivations will be built:
6527 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
6528 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
6532 Build the source derivations of all packages, as well of all transitive
6533 inputs to the packages. This can be used e.g. to
6534 prefetch package source for later offline building.
6537 $ guix build --sources=transitive tzdata
6538 The following derivations will be built:
6539 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
6540 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
6541 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
6542 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
6543 /gnu/store/@dots{}-make-4.1.tar.xz.drv
6544 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
6550 @item --system=@var{system}
6551 @itemx -s @var{system}
6552 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
6553 the system type of the build host.
6556 The @code{--system} flag is for @emph{native} compilation and must not
6557 be confused with cross-compilation. See @code{--target} below for
6558 information on cross-compilation.
6561 An example use of this is on Linux-based systems, which can emulate
6562 different personalities. For instance, passing
6563 @code{--system=i686-linux} on an @code{x86_64-linux} system or
6564 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
6565 to build packages in a complete 32-bit environment.
6568 Building for an @code{armhf-linux} system is unconditionally enabled on
6569 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
6570 allow for this functionality, notably the ThunderX.
6573 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
6574 is enabled (@pxref{Virtualization Services,
6575 @code{qemu-binfmt-service-type}}), you can build for any system for
6576 which a QEMU @code{binfmt_misc} handler is installed.
6578 Builds for a system other than that of the machine you are using can
6579 also be offloaded to a remote machine of the right architecture.
6580 @xref{Daemon Offload Setup}, for more information on offloading.
6582 @item --target=@var{triplet}
6583 @cindex cross-compilation
6584 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
6585 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
6586 configuration triplets,, autoconf, Autoconf}).
6588 @anchor{build-check}
6590 @cindex determinism, checking
6591 @cindex reproducibility, checking
6592 Rebuild @var{package-or-derivation}, which are already available in the
6593 store, and raise an error if the build results are not bit-for-bit
6596 This mechanism allows you to check whether previously installed
6597 substitutes are genuine (@pxref{Substitutes}), or whether the build result
6598 of a package is deterministic. @xref{Invoking guix challenge}, for more
6599 background information and tools.
6601 When used in conjunction with @option{--keep-failed}, the differing
6602 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
6603 This makes it easy to look for differences between the two results.
6606 @cindex repairing store items
6607 @cindex corruption, recovering from
6608 Attempt to repair the specified store items, if they are corrupt, by
6609 re-downloading or rebuilding them.
6611 This operation is not atomic and thus restricted to @code{root}.
6615 Return the derivation paths, not the output paths, of the given
6618 @item --root=@var{file}
6619 @itemx -r @var{file}
6620 @cindex GC roots, adding
6621 @cindex garbage collector roots, adding
6622 Make @var{file} a symlink to the result, and register it as a garbage
6625 Consequently, the results of this @command{guix build} invocation are
6626 protected from garbage collection until @var{file} is removed. When
6627 that option is omitted, build results are eligible for garbage
6628 collection as soon as the build completes. @xref{Invoking guix gc}, for
6632 @cindex build logs, access
6633 Return the build log file names or URLs for the given
6634 @var{package-or-derivation}, or raise an error if build logs are
6637 This works regardless of how packages or derivations are specified. For
6638 instance, the following invocations are equivalent:
6641 guix build --log-file `guix build -d guile`
6642 guix build --log-file `guix build guile`
6643 guix build --log-file guile
6644 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
6647 If a log is unavailable locally, and unless @code{--no-substitutes} is
6648 passed, the command looks for a corresponding log on one of the
6649 substitute servers (as specified with @code{--substitute-urls}.)
6651 So for instance, imagine you want to see the build log of GDB on MIPS,
6652 but you are actually on an @code{x86_64} machine:
6655 $ guix build --log-file gdb -s mips64el-linux
6656 https://hydra.gnu.org/log/@dots{}-gdb-7.10
6659 You can freely access a huge library of build logs!
6662 @node Debugging Build Failures
6663 @subsection Debugging Build Failures
6665 @cindex build failures, debugging
6666 When defining a new package (@pxref{Defining Packages}), you will
6667 probably find yourself spending some time debugging and tweaking the
6668 build until it succeeds. To do that, you need to operate the build
6669 commands yourself in an environment as close as possible to the one the
6672 To that end, the first thing to do is to use the @option{--keep-failed}
6673 or @option{-K} option of @command{guix build}, which will keep the
6674 failed build tree in @file{/tmp} or whatever directory you specified as
6675 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
6677 From there on, you can @command{cd} to the failed build tree and source
6678 the @file{environment-variables} file, which contains all the
6679 environment variable definitions that were in place when the build
6680 failed. So let's say you're debugging a build failure in package
6681 @code{foo}; a typical session would look like this:
6685 @dots{} @i{build fails}
6686 $ cd /tmp/guix-build-foo.drv-0
6687 $ source ./environment-variables
6691 Now, you can invoke commands as if you were the daemon (almost) and
6692 troubleshoot your build process.
6694 Sometimes it happens that, for example, a package's tests pass when you
6695 run them manually but they fail when the daemon runs them. This can
6696 happen because the daemon runs builds in containers where, unlike in our
6697 environment above, network access is missing, @file{/bin/sh} does not
6698 exist, etc. (@pxref{Build Environment Setup}).
6700 In such cases, you may need to run inspect the build process from within
6701 a container similar to the one the build daemon creates:
6706 $ cd /tmp/guix-build-foo.drv-0
6707 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
6708 [env]# source ./environment-variables
6712 Here, @command{guix environment -C} creates a container and spawns a new
6713 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
6714 strace gdb} part adds the @command{strace} and @command{gdb} commands to
6715 the container, which would may find handy while debugging. The
6716 @option{--no-grafts} option makes sure we get the exact same
6717 environment, with ungrafted packages (@pxref{Security Updates}, for more
6720 To get closer to a container like that used by the build daemon, we can
6721 remove @file{/bin/sh}:
6727 (Don't worry, this is harmless: this is all happening in the throw-away
6728 container created by @command{guix environment}.)
6730 The @command{strace} command is probably not in the search path, but we
6734 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
6737 In this way, not only you will have reproduced the environment variables
6738 the daemon uses, you will also be running the build process in a container
6739 similar to the one the daemon uses.
6742 @node Invoking guix edit
6743 @section Invoking @command{guix edit}
6745 @cindex @command{guix edit}
6746 @cindex package definition, editing
6747 So many packages, so many source files! The @command{guix edit} command
6748 facilitates the life of users and packagers by pointing their editor at
6749 the source file containing the definition of the specified packages.
6753 guix edit gcc@@4.9 vim
6757 launches the program specified in the @code{VISUAL} or in the
6758 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
6761 If you are using a Guix Git checkout (@pxref{Building from Git}), or
6762 have created your own packages on @code{GUIX_PACKAGE_PATH}
6763 (@pxref{Package Modules}), you will be able to edit the package
6764 recipes. In other cases, you will be able to examine the read-only recipes
6765 for packages currently in the store.
6768 @node Invoking guix download
6769 @section Invoking @command{guix download}
6771 @cindex @command{guix download}
6772 @cindex downloading package sources
6773 When writing a package definition, developers typically need to download
6774 a source tarball, compute its SHA256 hash, and write that
6775 hash in the package definition (@pxref{Defining Packages}). The
6776 @command{guix download} tool helps with this task: it downloads a file
6777 from the given URI, adds it to the store, and prints both its file name
6778 in the store and its SHA256 hash.
6780 The fact that the downloaded file is added to the store saves bandwidth:
6781 when the developer eventually tries to build the newly defined package
6782 with @command{guix build}, the source tarball will not have to be
6783 downloaded again because it is already in the store. It is also a
6784 convenient way to temporarily stash files, which may be deleted
6785 eventually (@pxref{Invoking guix gc}).
6787 The @command{guix download} command supports the same URIs as used in
6788 package definitions. In particular, it supports @code{mirror://} URIs.
6789 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
6790 Guile bindings for GnuTLS are available in the user's environment; when
6791 they are not available, an error is raised. @xref{Guile Preparations,
6792 how to install the GnuTLS bindings for Guile,, gnutls-guile,
6793 GnuTLS-Guile}, for more information.
6795 @command{guix download} verifies HTTPS server certificates by loading
6796 the certificates of X.509 authorities from the directory pointed to by
6797 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
6798 Certificates}), unless @option{--no-check-certificate} is used.
6800 The following options are available:
6803 @item --format=@var{fmt}
6805 Write the hash in the format specified by @var{fmt}. For more
6806 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
6808 @item --no-check-certificate
6809 Do not validate the X.509 certificates of HTTPS servers.
6811 When using this option, you have @emph{absolutely no guarantee} that you
6812 are communicating with the authentic server responsible for the given
6813 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
6815 @item --output=@var{file}
6816 @itemx -o @var{file}
6817 Save the downloaded file to @var{file} instead of adding it to the
6821 @node Invoking guix hash
6822 @section Invoking @command{guix hash}
6824 @cindex @command{guix hash}
6825 The @command{guix hash} command computes the SHA256 hash of a file.
6826 It is primarily a convenience tool for anyone contributing to the
6827 distribution: it computes the cryptographic hash of a file, which can be
6828 used in the definition of a package (@pxref{Defining Packages}).
6830 The general syntax is:
6833 guix hash @var{option} @var{file}
6836 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
6837 hash of data read from standard input. @command{guix hash} has the
6842 @item --format=@var{fmt}
6844 Write the hash in the format specified by @var{fmt}.
6846 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
6847 (@code{hex} and @code{hexadecimal} can be used as well).
6849 If the @option{--format} option is not specified, @command{guix hash}
6850 will output the hash in @code{nix-base32}. This representation is used
6851 in the definitions of packages.
6855 Compute the hash on @var{file} recursively.
6857 In this case, the hash is computed on an archive containing @var{file},
6858 including its children if it is a directory. Some of the metadata of
6859 @var{file} is part of the archive; for instance, when @var{file} is a
6860 regular file, the hash is different depending on whether @var{file} is
6861 executable or not. Metadata such as time stamps has no impact on the
6862 hash (@pxref{Invoking guix archive}).
6863 @c FIXME: Replace xref above with xref to an ``Archive'' section when
6868 When combined with @option{--recursive}, exclude version control system
6869 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
6872 As an example, here is how you would compute the hash of a Git checkout,
6873 which is useful when using the @code{git-fetch} method (@pxref{origin
6877 $ git clone http://example.org/foo.git
6883 @node Invoking guix import
6884 @section Invoking @command{guix import}
6886 @cindex importing packages
6887 @cindex package import
6888 @cindex package conversion
6889 @cindex Invoking @command{guix import}
6890 The @command{guix import} command is useful for people who would like to
6891 add a package to the distribution with as little work as
6892 possible---a legitimate demand. The command knows of a few
6893 repositories from which it can ``import'' package metadata. The result
6894 is a package definition, or a template thereof, in the format we know
6895 (@pxref{Defining Packages}).
6897 The general syntax is:
6900 guix import @var{importer} @var{options}@dots{}
6903 @var{importer} specifies the source from which to import package
6904 metadata, and @var{options} specifies a package identifier and other
6905 options specific to @var{importer}. Currently, the available
6910 Import metadata for the given GNU package. This provides a template
6911 for the latest version of that GNU package, including the hash of its
6912 source tarball, and its canonical synopsis and description.
6914 Additional information such as the package dependencies and its
6915 license needs to be figured out manually.
6917 For example, the following command returns a package definition for
6921 guix import gnu hello
6924 Specific command-line options are:
6927 @item --key-download=@var{policy}
6928 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
6929 keys when verifying the package signature. @xref{Invoking guix
6930 refresh, @code{--key-download}}.
6935 Import metadata from the @uref{https://pypi.python.org/, Python Package
6936 Index}@footnote{This functionality requires Guile-JSON to be installed.
6937 @xref{Requirements}.}. Information is taken from the JSON-formatted
6938 description available at @code{pypi.python.org} and usually includes all
6939 the relevant information, including package dependencies. For maximum
6940 efficiency, it is recommended to install the @command{unzip} utility, so
6941 that the importer can unzip Python wheels and gather data from them.
6943 The command below imports metadata for the @code{itsdangerous} Python
6947 guix import pypi itsdangerous
6953 Traverse the dependency graph of the given upstream package recursively
6954 and generate package expressions for all those packages that are not yet
6960 Import metadata from @uref{https://rubygems.org/,
6961 RubyGems}@footnote{This functionality requires Guile-JSON to be
6962 installed. @xref{Requirements}.}. Information is taken from the
6963 JSON-formatted description available at @code{rubygems.org} and includes
6964 most relevant information, including runtime dependencies. There are
6965 some caveats, however. The metadata doesn't distinguish between
6966 synopses and descriptions, so the same string is used for both fields.
6967 Additionally, the details of non-Ruby dependencies required to build
6968 native extensions is unavailable and left as an exercise to the
6971 The command below imports metadata for the @code{rails} Ruby package:
6974 guix import gem rails
6980 Traverse the dependency graph of the given upstream package recursively
6981 and generate package expressions for all those packages that are not yet
6987 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}@footnote{This
6988 functionality requires Guile-JSON to be installed.
6989 @xref{Requirements}.}.
6990 Information is taken from the JSON-formatted metadata provided through
6991 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
6992 relevant information, such as module dependencies. License information
6993 should be checked closely. If Perl is available in the store, then the
6994 @code{corelist} utility will be used to filter core modules out of the
6995 list of dependencies.
6997 The command command below imports metadata for the @code{Acme::Boolean}
7001 guix import cpan Acme::Boolean
7006 @cindex Bioconductor
7007 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
7008 central repository for the @uref{http://r-project.org, GNU@tie{}R
7009 statistical and graphical environment}.
7011 Information is extracted from the @code{DESCRIPTION} file of the package.
7013 The command command below imports metadata for the @code{Cairo}
7017 guix import cran Cairo
7020 When @code{--recursive} is added, the importer will traverse the
7021 dependency graph of the given upstream package recursively and generate
7022 package expressions for all those packages that are not yet in Guix.
7024 When @code{--archive=bioconductor} is added, metadata is imported from
7025 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
7026 packages for for the analysis and comprehension of high-throughput
7027 genomic data in bioinformatics.
7029 Information is extracted from the @code{DESCRIPTION} file of a package
7030 published on the web interface of the Bioconductor SVN repository.
7032 The command below imports metadata for the @code{GenomicRanges}
7036 guix import cran --archive=bioconductor GenomicRanges
7042 Import metadata from @uref{http://www.ctan.org/, CTAN}, the
7043 comprehensive TeX archive network for TeX packages that are part of the
7044 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
7046 Information about the package is obtained through the XML API provided
7047 by CTAN, while the source code is downloaded from the SVN repository of
7048 the Tex Live project. This is done because the CTAN does not keep
7051 The command command below imports metadata for the @code{fontspec}
7055 guix import texlive fontspec
7058 When @code{--archive=DIRECTORY} is added, the source code is downloaded
7059 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
7060 tree in the TeX Live SVN repository, but from the specified sibling
7061 directory under the same root.
7063 The command below imports metadata for the @code{ifxetex} package from
7064 CTAN while fetching the sources from the directory
7065 @file{texmf/source/generic}:
7068 guix import texlive --archive=generic ifxetex
7072 @cindex JSON, import
7073 Import package metadata from a local JSON file@footnote{This
7074 functionality requires Guile-JSON to be installed.
7075 @xref{Requirements}.}. Consider the following example package
7076 definition in JSON format:
7082 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
7083 "build-system": "gnu",
7084 "home-page": "https://www.gnu.org/software/hello/",
7085 "synopsis": "Hello, GNU world: An example GNU package",
7086 "description": "GNU Hello prints a greeting.",
7087 "license": "GPL-3.0+",
7088 "native-inputs": ["gcc@@6"]
7092 The field names are the same as for the @code{<package>} record
7093 (@xref{Defining Packages}). References to other packages are provided
7094 as JSON lists of quoted package specification strings such as
7095 @code{guile} or @code{guile@@2.0}.
7097 The importer also supports a more explicit source definition using the
7098 common fields for @code{<origin>} records:
7104 "method": "url-fetch",
7105 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
7107 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
7114 The command below reads metadata from the JSON file @code{hello.json}
7115 and outputs a package expression:
7118 guix import json hello.json
7122 Import metadata from a local copy of the source of the
7123 @uref{http://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
7124 relies on the @command{nix-instantiate} command of
7125 @uref{http://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
7126 typically written in a mixture of Nix-language and Bash code. This
7127 command only imports the high-level package structure that is written in
7128 the Nix language. It normally includes all the basic fields of a
7131 When importing a GNU package, the synopsis and descriptions are replaced
7132 by their canonical upstream variant.
7134 Usually, you will first need to do:
7137 export NIX_REMOTE=daemon
7141 so that @command{nix-instantiate} does not try to open the Nix database.
7143 As an example, the command below imports the package definition of
7144 LibreOffice (more precisely, it imports the definition of the package
7145 bound to the @code{libreoffice} top-level attribute):
7148 guix import nix ~/path/to/nixpkgs libreoffice
7153 Import metadata from the Haskell community's central package archive
7154 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
7155 Cabal files and includes all the relevant information, including package
7158 Specific command-line options are:
7163 Read a Cabal file from standard input.
7164 @item --no-test-dependencies
7166 Do not include dependencies required only by the test suites.
7167 @item --cabal-environment=@var{alist}
7168 @itemx -e @var{alist}
7169 @var{alist} is a Scheme alist defining the environment in which the
7170 Cabal conditionals are evaluated. The accepted keys are: @code{os},
7171 @code{arch}, @code{impl} and a string representing the name of a flag.
7172 The value associated with a flag has to be either the symbol
7173 @code{true} or @code{false}. The value associated with other keys
7174 has to conform to the Cabal file format definition. The default value
7175 associated with the keys @code{os}, @code{arch} and @code{impl} is
7176 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
7179 Traverse the dependency graph of the given upstream package recursively
7180 and generate package expressions for all those packages that are not yet
7184 The command below imports metadata for the latest version of the
7185 @code{HTTP} Haskell package without including test dependencies and
7186 specifying the value of the flag @samp{network-uri} as @code{false}:
7189 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
7192 A specific package version may optionally be specified by following the
7193 package name by an at-sign and a version number as in the following example:
7196 guix import hackage mtl@@2.1.3.1
7201 The @code{stackage} importer is a wrapper around the @code{hackage} one.
7202 It takes a package name, looks up the package version included in a
7203 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
7204 release and uses the @code{hackage} importer to retrieve its metadata.
7205 Note that it is up to you to select an LTS release compatible with the
7206 GHC compiler used by Guix.
7208 Specific command-line options are:
7211 @item --no-test-dependencies
7213 Do not include dependencies required only by the test suites.
7214 @item --lts-version=@var{version}
7215 @itemx -l @var{version}
7216 @var{version} is the desired LTS release version. If omitted the latest
7220 Traverse the dependency graph of the given upstream package recursively
7221 and generate package expressions for all those packages that are not yet
7225 The command below imports metadata for the @code{HTTP} Haskell package
7226 included in the LTS Stackage release version 7.18:
7229 guix import stackage --lts-version=7.18 HTTP
7234 Import metadata from an Emacs Lisp Package Archive (ELPA) package
7235 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
7237 Specific command-line options are:
7240 @item --archive=@var{repo}
7241 @itemx -a @var{repo}
7242 @var{repo} identifies the archive repository from which to retrieve the
7243 information. Currently the supported repositories and their identifiers
7247 @uref{http://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
7248 identifier. This is the default.
7250 Packages from @code{elpa.gnu.org} are signed with one of the keys
7251 contained in the GnuPG keyring at
7252 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
7253 @code{emacs} package (@pxref{Package Installation, ELPA package
7254 signatures,, emacs, The GNU Emacs Manual}).
7257 @uref{http://stable.melpa.org/packages, MELPA-Stable}, selected by the
7258 @code{melpa-stable} identifier.
7261 @uref{http://melpa.org/packages, MELPA}, selected by the @code{melpa}
7267 Traverse the dependency graph of the given upstream package recursively
7268 and generate package expressions for all those packages that are not yet
7274 Import metadata from the crates.io Rust package repository
7275 @uref{https://crates.io, crates.io}.
7280 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
7281 repository used by the OCaml community.
7284 The structure of the @command{guix import} code is modular. It would be
7285 useful to have more importers for other package formats, and your help
7286 is welcome here (@pxref{Contributing}).
7288 @node Invoking guix refresh
7289 @section Invoking @command{guix refresh}
7291 @cindex @command {guix refresh}
7292 The primary audience of the @command{guix refresh} command is developers
7293 of the GNU software distribution. By default, it reports any packages
7294 provided by the distribution that are outdated compared to the latest
7295 upstream version, like this:
7299 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
7300 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
7303 Alternately, one can specify packages to consider, in which case a
7304 warning is emitted for packages that lack an updater:
7307 $ guix refresh coreutils guile guile-ssh
7308 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
7309 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
7312 @command{guix refresh} browses the upstream repository of each package and determines
7313 the highest version number of the releases therein. The command
7314 knows how to update specific types of packages: GNU packages, ELPA
7315 packages, etc.---see the documentation for @option{--type} below. There
7316 are many packages, though, for which it lacks a method to determine
7317 whether a new upstream release is available. However, the mechanism is
7318 extensible, so feel free to get in touch with us to add a new method!
7320 Sometimes the upstream name differs from the package name used in Guix,
7321 and @command{guix refresh} needs a little help. Most updaters honor the
7322 @code{upstream-name} property in package definitions, which can be used
7326 (define-public network-manager
7328 (name "network-manager")
7330 (properties '((upstream-name . "NetworkManager")))))
7333 When passed @code{--update}, it modifies distribution source files to
7334 update the version numbers and source tarball hashes of those package
7335 recipes (@pxref{Defining Packages}). This is achieved by downloading
7336 each package's latest source tarball and its associated OpenPGP
7337 signature, authenticating the downloaded tarball against its signature
7338 using @command{gpg}, and finally computing its hash. When the public
7339 key used to sign the tarball is missing from the user's keyring, an
7340 attempt is made to automatically retrieve it from a public key server;
7341 when this is successful, the key is added to the user's keyring; otherwise,
7342 @command{guix refresh} reports an error.
7344 The following options are supported:
7348 @item --expression=@var{expr}
7349 @itemx -e @var{expr}
7350 Consider the package @var{expr} evaluates to.
7352 This is useful to precisely refer to a package, as in this example:
7355 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
7358 This command lists the dependents of the ``final'' libc (essentially all
7363 Update distribution source files (package recipes) in place. This is
7364 usually run from a checkout of the Guix source tree (@pxref{Running
7365 Guix Before It Is Installed}):
7368 $ ./pre-inst-env guix refresh -s non-core -u
7371 @xref{Defining Packages}, for more information on package definitions.
7373 @item --select=[@var{subset}]
7374 @itemx -s @var{subset}
7375 Select all the packages in @var{subset}, one of @code{core} or
7378 The @code{core} subset refers to all the packages at the core of the
7379 distribution---i.e., packages that are used to build ``everything
7380 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
7381 changing one of these packages in the distribution entails a rebuild of
7382 all the others. Thus, such updates are an inconvenience to users in
7383 terms of build time or bandwidth used to achieve the upgrade.
7385 The @code{non-core} subset refers to the remaining packages. It is
7386 typically useful in cases where an update of the core packages would be
7389 @item --manifest=@var{file}
7390 @itemx -m @var{file}
7391 Select all the packages from the manifest in @var{file}. This is useful to
7392 check if any packages of the user manifest can be updated.
7394 @item --type=@var{updater}
7395 @itemx -t @var{updater}
7396 Select only packages handled by @var{updater} (may be a comma-separated
7397 list of updaters). Currently, @var{updater} may be one of:
7401 the updater for GNU packages;
7403 the updater for GNOME packages;
7405 the updater for KDE packages;
7407 the updater for X.org packages;
7409 the updater for packages hosted on kernel.org;
7411 the updater for @uref{http://elpa.gnu.org/, ELPA} packages;
7413 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
7415 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
7417 the updater for @uref{http://www.cpan.org/, CPAN} packages;
7419 the updater for @uref{https://pypi.python.org, PyPI} packages.
7421 the updater for @uref{https://rubygems.org, RubyGems} packages.
7423 the updater for @uref{https://github.com, GitHub} packages.
7425 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
7427 the updater for @uref{https://www.stackage.org, Stackage} packages.
7429 the updater for @uref{https://crates.io, Crates} packages.
7432 For instance, the following command only checks for updates of Emacs
7433 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
7436 $ guix refresh --type=elpa,cran
7437 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
7438 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
7443 In addition, @command{guix refresh} can be passed one or more package
7444 names, as in this example:
7447 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
7451 The command above specifically updates the @code{emacs} and
7452 @code{idutils} packages. The @code{--select} option would have no
7453 effect in this case.
7455 When considering whether to upgrade a package, it is sometimes
7456 convenient to know which packages would be affected by the upgrade and
7457 should be checked for compatibility. For this the following option may
7458 be used when passing @command{guix refresh} one or more package names:
7462 @item --list-updaters
7464 List available updaters and exit (see @option{--type} above.)
7466 For each updater, display the fraction of packages it covers; at the
7467 end, display the fraction of packages covered by all these updaters.
7469 @item --list-dependent
7471 List top-level dependent packages that would need to be rebuilt as a
7472 result of upgrading one or more packages.
7474 @xref{Invoking guix graph, the @code{reverse-package} type of
7475 @command{guix graph}}, for information on how to visualize the list of
7476 dependents of a package.
7480 Be aware that the @code{--list-dependent} option only
7481 @emph{approximates} the rebuilds that would be required as a result of
7482 an upgrade. More rebuilds might be required under some circumstances.
7485 $ guix refresh --list-dependent flex
7486 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
7487 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
7490 The command above lists a set of packages that could be built to check
7491 for compatibility with an upgraded @code{flex} package.
7493 The following options can be used to customize GnuPG operation:
7497 @item --gpg=@var{command}
7498 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
7499 for in @code{$PATH}.
7501 @item --keyring=@var{file}
7502 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
7503 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
7504 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
7505 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
7506 information on a tool to manipulate keybox files).
7508 When this option is omitted, @command{guix refresh} uses
7509 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
7510 signing keys. OpenPGP signatures are checked against keys from this keyring;
7511 missing keys are downloaded to this keyring as well (see
7512 @option{--key-download} below.)
7514 You can export keys from your default GPG keyring into a keybox file using
7515 commands like this one:
7518 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
7521 Likewise, you can fetch keys to a specific keybox file like this:
7524 gpg --no-default-keyring --keyring mykeyring.kbx \
7525 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
7528 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
7529 Privacy Guard}, for more information on GPG's @option{--keyring} option.
7531 @item --key-download=@var{policy}
7532 Handle missing OpenPGP keys according to @var{policy}, which may be one
7537 Always download missing OpenPGP keys from the key server, and add them
7538 to the user's GnuPG keyring.
7541 Never try to download missing OpenPGP keys. Instead just bail out.
7544 When a package signed with an unknown OpenPGP key is encountered, ask
7545 the user whether to download it or not. This is the default behavior.
7548 @item --key-server=@var{host}
7549 Use @var{host} as the OpenPGP key server when importing a public key.
7553 The @code{github} updater uses the
7554 @uref{https://developer.github.com/v3/, GitHub API} to query for new
7555 releases. When used repeatedly e.g. when refreshing all packages,
7556 GitHub will eventually refuse to answer any further API requests. By
7557 default 60 API requests per hour are allowed, and a full refresh on all
7558 GitHub packages in Guix requires more than this. Authentication with
7559 GitHub through the use of an API token alleviates these limits. To use
7560 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
7561 token procured from @uref{https://github.com/settings/tokens} or
7565 @node Invoking guix lint
7566 @section Invoking @command{guix lint}
7568 @cindex @command{guix lint}
7569 @cindex package, checking for errors
7570 The @command{guix lint} command is meant to help package developers avoid
7571 common errors and use a consistent style. It runs a number of checks on
7572 a given set of packages in order to find common mistakes in their
7573 definitions. Available @dfn{checkers} include (see
7574 @code{--list-checkers} for a complete list):
7579 Validate certain typographical and stylistic rules about package
7580 descriptions and synopses.
7582 @item inputs-should-be-native
7583 Identify inputs that should most likely be native inputs.
7588 @itemx source-file-name
7589 Probe @code{home-page} and @code{source} URLs and report those that are
7590 invalid. Suggest a @code{mirror://} URL when applicable. Check that
7591 the source file name is meaningful, e.g. is not
7592 just a version number or ``git-checkout'', without a declared
7593 @code{file-name} (@pxref{origin Reference}).
7596 @cindex security vulnerabilities
7597 @cindex CVE, Common Vulnerabilities and Exposures
7598 Report known vulnerabilities found in the Common Vulnerabilities and
7599 Exposures (CVE) databases of the current and past year
7600 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
7603 To view information about a particular vulnerability, visit pages such as:
7607 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
7609 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
7613 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
7614 @code{CVE-2015-7554}.
7616 Package developers can specify in package recipes the
7617 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
7618 name and version of the package when they differ from the name or version
7619 that Guix uses, as in this example:
7625 ;; CPE calls this package "grub2".
7626 (properties '((cpe-name . "grub2")
7627 (cpe-version . "2.3")))
7630 @c See <http://www.openwall.com/lists/oss-security/2017/03/15/3>.
7631 Some entries in the CVE database do not specify which version of a
7632 package they apply to, and would thus ``stick around'' forever. Package
7633 developers who found CVE alerts and verified they can be ignored can
7634 declare them as in this example:
7640 ;; These CVEs no longer apply and can be safely ignored.
7641 (properties `((lint-hidden-cve . ("CVE-2011-0433"
7644 "CVE-2011-5244")))))
7648 Warn about obvious source code formatting issues: trailing white space,
7649 use of tabulations, etc.
7652 The general syntax is:
7655 guix lint @var{options} @var{package}@dots{}
7658 If no package is given on the command line, then all packages are checked.
7659 The @var{options} may be zero or more of the following:
7662 @item --list-checkers
7664 List and describe all the available checkers that will be run on packages
7669 Only enable the checkers specified in a comma-separated list using the
7670 names returned by @code{--list-checkers}.
7674 @node Invoking guix size
7675 @section Invoking @command{guix size}
7678 @cindex package size
7680 @cindex @command{guix size}
7681 The @command{guix size} command helps package developers profile the
7682 disk usage of packages. It is easy to overlook the impact of an
7683 additional dependency added to a package, or the impact of using a
7684 single output for a package that could easily be split (@pxref{Packages
7685 with Multiple Outputs}). Such are the typical issues that
7686 @command{guix size} can highlight.
7688 The command can be passed one or more package specifications
7689 such as @code{gcc@@4.8}
7690 or @code{guile:debug}, or a file name in the store. Consider this
7694 $ guix size coreutils
7695 store item total self
7696 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
7697 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
7698 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
7699 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
7700 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
7701 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
7702 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
7703 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
7708 The store items listed here constitute the @dfn{transitive closure} of
7709 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
7710 would be returned by:
7713 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
7716 Here the output shows three columns next to store items. The first column,
7717 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
7718 the store item---that is, its own size plus the size of all its
7719 dependencies. The next column, labeled ``self'', shows the size of the
7720 item itself. The last column shows the ratio of the size of the item
7721 itself to the space occupied by all the items listed here.
7723 In this example, we see that the closure of Coreutils weighs in at
7724 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
7725 libraries. (That libc and GCC's libraries represent a large fraction of
7726 the closure is not a problem @i{per se} because they are always available
7727 on the system anyway.)
7729 When the package(s) passed to @command{guix size} are available in the
7730 store@footnote{More precisely, @command{guix size} looks for the
7731 @emph{ungrafted} variant of the given package(s), as returned by
7732 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
7733 for information on grafts.}, @command{guix size} queries the daemon to determine its
7734 dependencies, and measures its size in the store, similar to @command{du
7735 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
7738 When the given packages are @emph{not} in the store, @command{guix size}
7739 reports information based on the available substitutes
7740 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
7741 store items that are not even on disk, only available remotely.
7743 You can also specify several package names:
7746 $ guix size coreutils grep sed bash
7747 store item total self
7748 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
7749 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
7750 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
7751 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
7757 In this example we see that the combination of the four packages takes
7758 102.3@tie{}MiB in total, which is much less than the sum of each closure
7759 since they have a lot of dependencies in common.
7761 The available options are:
7765 @item --substitute-urls=@var{urls}
7766 Use substitute information from @var{urls}.
7767 @xref{client-substitute-urls, the same option for @code{guix build}}.
7769 @item --sort=@var{key}
7770 Sort lines according to @var{key}, one of the following options:
7774 the size of each item (the default);
7776 the total size of the item's closure.
7779 @item --map-file=@var{file}
7780 Write a graphical map of disk usage in PNG format to @var{file}.
7782 For the example above, the map looks like this:
7784 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
7785 produced by @command{guix size}}
7787 This option requires that
7788 @uref{http://wingolog.org/software/guile-charting/, Guile-Charting} be
7789 installed and visible in Guile's module search path. When that is not
7790 the case, @command{guix size} fails as it tries to load it.
7792 @item --system=@var{system}
7793 @itemx -s @var{system}
7794 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
7798 @node Invoking guix graph
7799 @section Invoking @command{guix graph}
7802 @cindex @command{guix graph}
7803 @cindex package dependencies
7804 Packages and their dependencies form a @dfn{graph}, specifically a
7805 directed acyclic graph (DAG). It can quickly become difficult to have a
7806 mental model of the package DAG, so the @command{guix graph} command
7807 provides a visual representation of the DAG. By default,
7808 @command{guix graph} emits a DAG representation in the input format of
7809 @uref{http://www.graphviz.org/, Graphviz}, so its output can be passed
7810 directly to the @command{dot} command of Graphviz. It can also emit an
7811 HTML page with embedded JavaScript code to display a ``chord diagram''
7812 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
7813 emit Cypher queries to construct a graph in a graph database supporting
7814 the @uref{http://www.opencypher.org/, openCypher} query language.
7815 The general syntax is:
7818 guix graph @var{options} @var{package}@dots{}
7821 For example, the following command generates a PDF file representing the
7822 package DAG for the GNU@tie{}Core Utilities, showing its build-time
7826 guix graph coreutils | dot -Tpdf > dag.pdf
7829 The output looks like this:
7831 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
7833 Nice little graph, no?
7835 But there is more than one graph! The one above is concise: it is the
7836 graph of package objects, omitting implicit inputs such as GCC, libc,
7837 grep, etc. It is often useful to have such a concise graph, but
7838 sometimes one may want to see more details. @command{guix graph} supports
7839 several types of graphs, allowing you to choose the level of detail:
7843 This is the default type used in the example above. It shows the DAG of
7844 package objects, excluding implicit dependencies. It is concise, but
7845 filters out many details.
7847 @item reverse-package
7848 This shows the @emph{reverse} DAG of packages. For example:
7851 guix graph --type=reverse-package ocaml
7854 ... yields the graph of packages that depend on OCaml.
7856 Note that for core packages this can yield huge graphs. If all you want
7857 is to know the number of packages that depend on a given package, use
7858 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
7859 @option{--list-dependent}}).
7862 This is the package DAG, @emph{including} implicit inputs.
7864 For instance, the following command:
7867 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
7870 ... yields this bigger graph:
7872 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
7874 At the bottom of the graph, we see all the implicit inputs of
7875 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
7877 Now, note that the dependencies of these implicit inputs---that is, the
7878 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
7879 here, for conciseness.
7882 Similar to @code{bag-emerged}, but this time including all the bootstrap
7885 @item bag-with-origins
7886 Similar to @code{bag}, but also showing origins and their dependencies.
7889 This is the most detailed representation: It shows the DAG of
7890 derivations (@pxref{Derivations}) and plain store items. Compared to
7891 the above representation, many additional nodes are visible, including
7892 build scripts, patches, Guile modules, etc.
7894 For this type of graph, it is also possible to pass a @file{.drv} file
7895 name instead of a package name, as in:
7898 guix graph -t derivation `guix system build -d my-config.scm`
7902 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
7903 For example, the following command shows the graph for the package
7904 module that defines the @code{guile} package:
7907 guix graph -t module guile | dot -Tpdf > module-graph.pdf
7911 All the types above correspond to @emph{build-time dependencies}. The
7912 following graph type represents the @emph{run-time dependencies}:
7916 This is the graph of @dfn{references} of a package output, as returned
7917 by @command{guix gc --references} (@pxref{Invoking guix gc}).
7919 If the given package output is not available in the store, @command{guix
7920 graph} attempts to obtain dependency information from substitutes.
7922 Here you can also pass a store file name instead of a package name. For
7923 example, the command below produces the reference graph of your profile
7924 (which can be big!):
7927 guix graph -t references `readlink -f ~/.guix-profile`
7931 This is the graph of the @dfn{referrers} of a store item, as returned by
7932 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
7934 This relies exclusively on local information from your store. For
7935 instance, let us suppose that the current Inkscape is available in 10
7936 profiles on your machine; @command{guix graph -t referrers inkscape}
7937 will show a graph rooted at Inkscape and with those 10 profiles linked
7940 It can help determine what is preventing a store item from being garbage
7945 The available options are the following:
7948 @item --type=@var{type}
7949 @itemx -t @var{type}
7950 Produce a graph output of @var{type}, where @var{type} must be one of
7951 the values listed above.
7954 List the supported graph types.
7956 @item --backend=@var{backend}
7957 @itemx -b @var{backend}
7958 Produce a graph using the selected @var{backend}.
7960 @item --list-backends
7961 List the supported graph backends.
7963 Currently, the available backends are Graphviz and d3.js.
7965 @item --expression=@var{expr}
7966 @itemx -e @var{expr}
7967 Consider the package @var{expr} evaluates to.
7969 This is useful to precisely refer to a package, as in this example:
7972 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
7975 @item --system=@var{system}
7976 @itemx -s @var{system}
7977 Display the graph for @var{system}---e.g., @code{i686-linux}.
7979 The package dependency graph is largely architecture-independent, but there
7980 are some architecture-dependent bits that this option allows you to visualize.
7984 @node Invoking guix environment
7985 @section Invoking @command{guix environment}
7987 @cindex reproducible build environments
7988 @cindex development environments
7989 @cindex @command{guix environment}
7990 @cindex environment, package build environment
7991 The purpose of @command{guix environment} is to assist hackers in
7992 creating reproducible development environments without polluting their
7993 package profile. The @command{guix environment} tool takes one or more
7994 packages, builds all of their inputs, and creates a shell
7995 environment to use them.
7997 The general syntax is:
8000 guix environment @var{options} @var{package}@dots{}
8003 The following example spawns a new shell set up for the development of
8007 guix environment guile
8010 If the needed dependencies are not built yet, @command{guix environment}
8011 automatically builds them. The environment of the new shell is an augmented
8012 version of the environment that @command{guix environment} was run in.
8013 It contains the necessary search paths for building the given package
8014 added to the existing environment variables. To create a ``pure''
8015 environment, in which the original environment variables have been unset,
8016 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
8017 environment variables such as @code{PATH} in their @file{~/.bashrc}
8018 file. As a consequence, when @code{guix environment} launches it, Bash
8019 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
8020 environment variables. It is an error to define such environment
8021 variables in @file{.bashrc}; instead, they should be defined in
8022 @file{.bash_profile}, which is sourced only by log-in shells.
8023 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
8024 details on Bash start-up files.}.
8026 @vindex GUIX_ENVIRONMENT
8027 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
8028 variable in the shell it spawns; its value is the file name of the
8029 profile of this environment. This allows users to, say, define a
8030 specific prompt for development environments in their @file{.bashrc}
8031 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
8034 if [ -n "$GUIX_ENVIRONMENT" ]
8036 export PS1="\u@@\h \w [dev]\$ "
8041 ... or to browse the profile:
8044 $ ls "$GUIX_ENVIRONMENT/bin"
8047 Additionally, more than one package may be specified, in which case the
8048 union of the inputs for the given packages are used. For example, the
8049 command below spawns a shell where all of the dependencies of both Guile
8050 and Emacs are available:
8053 guix environment guile emacs
8056 Sometimes an interactive shell session is not desired. An arbitrary
8057 command may be invoked by placing the @code{--} token to separate the
8058 command from the rest of the arguments:
8061 guix environment guile -- make -j4
8064 In other situations, it is more convenient to specify the list of
8065 packages needed in the environment. For example, the following command
8066 runs @command{python} from an environment containing Python@tie{}2.7 and
8070 guix environment --ad-hoc python2-numpy python-2.7 -- python
8073 Furthermore, one might want the dependencies of a package and also some
8074 additional packages that are not build-time or runtime dependencies, but
8075 are useful when developing nonetheless. Because of this, the
8076 @code{--ad-hoc} flag is positional. Packages appearing before
8077 @code{--ad-hoc} are interpreted as packages whose dependencies will be
8078 added to the environment. Packages appearing after are interpreted as
8079 packages that will be added to the environment directly. For example,
8080 the following command creates a Guix development environment that
8081 additionally includes Git and strace:
8084 guix environment guix --ad-hoc git strace
8087 Sometimes it is desirable to isolate the environment as much as
8088 possible, for maximal purity and reproducibility. In particular, when
8089 using Guix on a host distro that is not GuixSD, it is desirable to
8090 prevent access to @file{/usr/bin} and other system-wide resources from
8091 the development environment. For example, the following command spawns
8092 a Guile REPL in a ``container'' where only the store and the current
8093 working directory are mounted:
8096 guix environment --ad-hoc --container guile -- guile
8100 The @code{--container} option requires Linux-libre 3.19 or newer.
8103 The available options are summarized below.
8106 @item --root=@var{file}
8107 @itemx -r @var{file}
8108 @cindex persistent environment
8109 @cindex garbage collector root, for environments
8110 Make @var{file} a symlink to the profile for this environment, and
8111 register it as a garbage collector root.
8113 This is useful if you want to protect your environment from garbage
8114 collection, to make it ``persistent''.
8116 When this option is omitted, the environment is protected from garbage
8117 collection only for the duration of the @command{guix environment}
8118 session. This means that next time you recreate the same environment,
8119 you could have to rebuild or re-download packages. @xref{Invoking guix
8120 gc}, for more on GC roots.
8122 @item --expression=@var{expr}
8123 @itemx -e @var{expr}
8124 Create an environment for the package or list of packages that
8125 @var{expr} evaluates to.
8127 For example, running:
8130 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
8133 starts a shell with the environment for this specific variant of the
8139 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
8142 starts a shell with all the GuixSD base packages available.
8144 The above commands only use the default output of the given packages.
8145 To select other outputs, two element tuples can be specified:
8148 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
8151 @item --load=@var{file}
8152 @itemx -l @var{file}
8153 Create an environment for the package or list of packages that the code
8154 within @var{file} evaluates to.
8156 As an example, @var{file} might contain a definition like this
8157 (@pxref{Defining Packages}):
8160 @verbatiminclude environment-gdb.scm
8163 @item --manifest=@var{file}
8164 @itemx -m @var{file}
8165 Create an environment for the packages contained in the manifest object
8166 returned by the Scheme code in @var{file}.
8168 This is similar to the same-named option in @command{guix package}
8169 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
8173 Include all specified packages in the resulting environment, as if an
8174 @i{ad hoc} package were defined with them as inputs. This option is
8175 useful for quickly creating an environment without having to write a
8176 package expression to contain the desired inputs.
8178 For instance, the command:
8181 guix environment --ad-hoc guile guile-sdl -- guile
8184 runs @command{guile} in an environment where Guile and Guile-SDL are
8187 Note that this example implicitly asks for the default output of
8188 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
8189 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
8190 of @code{glib} (@pxref{Packages with Multiple Outputs}).
8192 This option may be composed with the default behavior of @command{guix
8193 environment}. Packages appearing before @code{--ad-hoc} are interpreted
8194 as packages whose dependencies will be added to the environment, the
8195 default behavior. Packages appearing after are interpreted as packages
8196 that will be added to the environment directly.
8199 Unset existing environment variables when building the new environment.
8200 This has the effect of creating an environment in which search paths
8201 only contain package inputs.
8203 @item --search-paths
8204 Display the environment variable definitions that make up the
8207 @item --system=@var{system}
8208 @itemx -s @var{system}
8209 Attempt to build for @var{system}---e.g., @code{i686-linux}.
8214 Run @var{command} within an isolated container. The current working
8215 directory outside the container is mapped inside the container.
8216 Additionally, unless overridden with @code{--user}, a dummy home
8217 directory is created that matches the current user's home directory, and
8218 @file{/etc/passwd} is configured accordingly. The spawned process runs
8219 as the current user outside the container, but has root privileges in
8220 the context of the container.
8224 For containers, share the network namespace with the host system.
8225 Containers created without this flag only have access to the loopback
8228 @item --link-profile
8230 For containers, link the environment profile to
8231 @file{~/.guix-profile} within the container. This is equivalent to
8232 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
8233 within the container. Linking will fail and abort the environment if
8234 the directory already exists, which will certainly be the case if
8235 @command{guix environment} was invoked in the user's home directory.
8237 Certain packages are configured to look in
8238 @code{~/.guix-profile} for configuration files and data;@footnote{For
8239 example, the @code{fontconfig} package inspects
8240 @file{~/.guix-profile/share/fonts} for additional fonts.}
8241 @code{--link-profile} allows these programs to behave as expected within
8244 @item --user=@var{user}
8245 @itemx -u @var{user}
8246 For containers, use the username @var{user} in place of the current
8247 user. The generated @file{/etc/passwd} entry within the container will
8248 contain the name @var{user}; the home directory will be
8249 @file{/home/USER}; and no user GECOS data will be copied. @var{user}
8250 need not exist on the system.
8252 Additionally, any shared or exposed path (see @code{--share} and
8253 @code{--expose} respectively) whose target is within the current user's
8254 home directory will be remapped relative to @file{/home/USER}; this
8255 includes the automatic mapping of the current working directory.
8258 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
8260 guix environment --container --user=foo \
8261 --expose=$HOME/test \
8262 --expose=/tmp/target=$HOME/target
8265 While this will limit the leaking of user identity through home paths
8266 and each of the user fields, this is only one useful component of a
8267 broader privacy/anonymity solution---not one in and of itself.
8269 @item --expose=@var{source}[=@var{target}]
8270 For containers, expose the file system @var{source} from the host system
8271 as the read-only file system @var{target} within the container. If
8272 @var{target} is not specified, @var{source} is used as the target mount
8273 point in the container.
8275 The example below spawns a Guile REPL in a container in which the user's
8276 home directory is accessible read-only via the @file{/exchange}
8280 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
8283 @item --share=@var{source}[=@var{target}]
8284 For containers, share the file system @var{source} from the host system
8285 as the writable file system @var{target} within the container. If
8286 @var{target} is not specified, @var{source} is used as the target mount
8287 point in the container.
8289 The example below spawns a Guile REPL in a container in which the user's
8290 home directory is accessible for both reading and writing via the
8291 @file{/exchange} directory:
8294 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
8298 @command{guix environment}
8299 also supports all of the common build options that @command{guix
8300 build} supports (@pxref{Common Build Options}).
8303 @node Invoking guix publish
8304 @section Invoking @command{guix publish}
8306 @cindex @command{guix publish}
8307 The purpose of @command{guix publish} is to enable users to easily share
8308 their store with others, who can then use it as a substitute server
8309 (@pxref{Substitutes}).
8311 When @command{guix publish} runs, it spawns an HTTP server which allows
8312 anyone with network access to obtain substitutes from it. This means
8313 that any machine running Guix can also act as if it were a build farm,
8314 since the HTTP interface is compatible with Hydra, the software behind
8315 the @code{hydra.gnu.org} build farm.
8317 For security, each substitute is signed, allowing recipients to check
8318 their authenticity and integrity (@pxref{Substitutes}). Because
8319 @command{guix publish} uses the signing key of the system, which is only
8320 readable by the system administrator, it must be started as root; the
8321 @code{--user} option makes it drop root privileges early on.
8323 The signing key pair must be generated before @command{guix publish} is
8324 launched, using @command{guix archive --generate-key} (@pxref{Invoking
8327 The general syntax is:
8330 guix publish @var{options}@dots{}
8333 Running @command{guix publish} without any additional arguments will
8334 spawn an HTTP server on port 8080:
8340 Once a publishing server has been authorized (@pxref{Invoking guix
8341 archive}), the daemon may download substitutes from it:
8344 guix-daemon --substitute-urls=http://example.org:8080
8347 By default, @command{guix publish} compresses archives on the fly as it
8348 serves them. This ``on-the-fly'' mode is convenient in that it requires
8349 no setup and is immediately available. However, when serving lots of
8350 clients, we recommend using the @option{--cache} option, which enables
8351 caching of the archives before they are sent to clients---see below for
8352 details. The @command{guix weather} command provides a handy way to
8353 check what a server provides (@pxref{Invoking guix weather}).
8355 As a bonus, @command{guix publish} also serves as a content-addressed
8356 mirror for source files referenced in @code{origin} records
8357 (@pxref{origin Reference}). For instance, assuming @command{guix
8358 publish} is running on @code{example.org}, the following URL returns the
8359 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
8360 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
8363 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
8366 Obviously, these URLs only work for files that are in the store; in
8367 other cases, they return 404 (``Not Found'').
8369 @cindex build logs, publication
8370 Build logs are available from @code{/log} URLs like:
8373 http://example.org/log/gwspk@dots{}-guile-2.2.3
8377 When @command{guix-daemon} is configured to save compressed build logs,
8378 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
8379 URLs return the compressed log as-is, with an appropriate
8380 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
8381 running @command{guix-daemon} with @code{--log-compression=gzip} since
8382 Web browsers can automatically decompress it, which is not the case with
8385 The following options are available:
8388 @item --port=@var{port}
8389 @itemx -p @var{port}
8390 Listen for HTTP requests on @var{port}.
8392 @item --listen=@var{host}
8393 Listen on the network interface for @var{host}. The default is to
8394 accept connections from any interface.
8396 @item --user=@var{user}
8397 @itemx -u @var{user}
8398 Change privileges to @var{user} as soon as possible---i.e., once the
8399 server socket is open and the signing key has been read.
8401 @item --compression[=@var{level}]
8402 @itemx -C [@var{level}]
8403 Compress data using the given @var{level}. When @var{level} is zero,
8404 disable compression. The range 1 to 9 corresponds to different gzip
8405 compression levels: 1 is the fastest, and 9 is the best (CPU-intensive).
8408 Unless @option{--cache} is used, compression occurs on the fly and
8409 the compressed streams are not
8410 cached. Thus, to reduce load on the machine that runs @command{guix
8411 publish}, it may be a good idea to choose a low compression level, to
8412 run @command{guix publish} behind a caching proxy, or to use
8413 @option{--cache}. Using @option{--cache} has the advantage that it
8414 allows @command{guix publish} to add @code{Content-Length} HTTP header
8417 @item --cache=@var{directory}
8418 @itemx -c @var{directory}
8419 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
8420 and only serve archives that are in cache.
8422 When this option is omitted, archives and meta-data are created
8423 on-the-fly. This can reduce the available bandwidth, especially when
8424 compression is enabled, since this may become CPU-bound. Another
8425 drawback of the default mode is that the length of archives is not known
8426 in advance, so @command{guix publish} does not add a
8427 @code{Content-Length} HTTP header to its responses, which in turn
8428 prevents clients from knowing the amount of data being downloaded.
8430 Conversely, when @option{--cache} is used, the first request for a store
8431 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
8432 background process to @dfn{bake} the archive---computing its
8433 @code{.narinfo} and compressing the archive, if needed. Once the
8434 archive is cached in @var{directory}, subsequent requests succeed and
8435 are served directly from the cache, which guarantees that clients get
8436 the best possible bandwidth.
8438 The ``baking'' process is performed by worker threads. By default, one
8439 thread per CPU core is created, but this can be customized. See
8440 @option{--workers} below.
8442 When @option{--ttl} is used, cached entries are automatically deleted
8443 when they have expired.
8445 @item --workers=@var{N}
8446 When @option{--cache} is used, request the allocation of @var{N} worker
8447 threads to ``bake'' archives.
8449 @item --ttl=@var{ttl}
8450 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
8451 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
8452 days, @code{1m} means 1 month, and so on.
8454 This allows the user's Guix to keep substitute information in cache for
8455 @var{ttl}. However, note that @code{guix publish} does not itself
8456 guarantee that the store items it provides will indeed remain available
8457 for as long as @var{ttl}.
8459 Additionally, when @option{--cache} is used, cached entries that have
8460 not been accessed for @var{ttl} and that no longer have a corresponding
8461 item in the store, may be deleted.
8463 @item --nar-path=@var{path}
8464 Use @var{path} as the prefix for the URLs of ``nar'' files
8465 (@pxref{Invoking guix archive, normalized archives}).
8467 By default, nars are served at a URL such as
8468 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
8469 change the @code{/nar} part to @var{path}.
8471 @item --public-key=@var{file}
8472 @itemx --private-key=@var{file}
8473 Use the specific @var{file}s as the public/private key pair used to sign
8474 the store items being published.
8476 The files must correspond to the same key pair (the private key is used
8477 for signing and the public key is merely advertised in the signature
8478 metadata). They must contain keys in the canonical s-expression format
8479 as produced by @command{guix archive --generate-key} (@pxref{Invoking
8480 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
8481 @file{/etc/guix/signing-key.sec} are used.
8483 @item --repl[=@var{port}]
8484 @itemx -r [@var{port}]
8485 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
8486 Reference Manual}) on @var{port} (37146 by default). This is used
8487 primarily for debugging a running @command{guix publish} server.
8490 Enabling @command{guix publish} on a GuixSD system is a one-liner: just
8491 instantiate a @code{guix-publish-service-type} service in the @code{services} field
8492 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
8493 @code{guix-publish-service-type}}).
8495 If you are instead running Guix on a ``foreign distro'', follow these
8500 If your host distro uses the systemd init system:
8503 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
8504 /etc/systemd/system/
8505 # systemctl start guix-publish && systemctl enable guix-publish
8509 If your host distro uses the Upstart init system:
8512 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
8513 # start guix-publish
8517 Otherwise, proceed similarly with your distro's init system.
8520 @node Invoking guix challenge
8521 @section Invoking @command{guix challenge}
8523 @cindex reproducible builds
8524 @cindex verifiable builds
8525 @cindex @command{guix challenge}
8527 Do the binaries provided by this server really correspond to the source
8528 code it claims to build? Is a package build process deterministic?
8529 These are the questions the @command{guix challenge} command attempts to
8532 The former is obviously an important question: Before using a substitute
8533 server (@pxref{Substitutes}), one had better @emph{verify} that it
8534 provides the right binaries, and thus @emph{challenge} it. The latter
8535 is what enables the former: If package builds are deterministic, then
8536 independent builds of the package should yield the exact same result,
8537 bit for bit; if a server provides a binary different from the one
8538 obtained locally, it may be either corrupt or malicious.
8540 We know that the hash that shows up in @file{/gnu/store} file names is
8541 the hash of all the inputs of the process that built the file or
8542 directory---compilers, libraries, build scripts,
8543 etc. (@pxref{Introduction}). Assuming deterministic build processes,
8544 one store file name should map to exactly one build output.
8545 @command{guix challenge} checks whether there is, indeed, a single
8546 mapping by comparing the build outputs of several independent builds of
8547 any given store item.
8549 The command output looks like this:
8552 $ guix challenge --substitute-urls="https://hydra.gnu.org https://guix.example.org"
8553 updating list of substitutes from 'https://hydra.gnu.org'... 100.0%
8554 updating list of substitutes from 'https://guix.example.org'... 100.0%
8555 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
8556 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
8557 https://hydra.gnu.org/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
8558 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
8559 /gnu/store/@dots{}-git-2.5.0 contents differ:
8560 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
8561 https://hydra.gnu.org/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
8562 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
8563 /gnu/store/@dots{}-pius-2.1.1 contents differ:
8564 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
8565 https://hydra.gnu.org/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
8566 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
8570 6,406 store items were analyzed:
8571 - 4,749 (74.1%) were identical
8572 - 525 (8.2%) differed
8573 - 1,132 (17.7%) were inconclusive
8577 In this example, @command{guix challenge} first scans the store to
8578 determine the set of locally-built derivations---as opposed to store
8579 items that were downloaded from a substitute server---and then queries
8580 all the substitute servers. It then reports those store items for which
8581 the servers obtained a result different from the local build.
8583 @cindex non-determinism, in package builds
8584 As an example, @code{guix.example.org} always gets a different answer.
8585 Conversely, @code{hydra.gnu.org} agrees with local builds, except in the
8586 case of Git. This might indicate that the build process of Git is
8587 non-deterministic, meaning that its output varies as a function of
8588 various things that Guix does not fully control, in spite of building
8589 packages in isolated environments (@pxref{Features}). Most common
8590 sources of non-determinism include the addition of timestamps in build
8591 results, the inclusion of random numbers, and directory listings sorted
8592 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
8595 To find out what is wrong with this Git binary, we can do something along
8596 these lines (@pxref{Invoking guix archive}):
8599 $ wget -q -O - https://hydra.gnu.org/nar/@dots{}-git-2.5.0 \
8600 | guix archive -x /tmp/git
8601 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
8604 This command shows the difference between the files resulting from the
8605 local build, and the files resulting from the build on
8606 @code{hydra.gnu.org} (@pxref{Overview, Comparing and Merging Files,,
8607 diffutils, Comparing and Merging Files}). The @command{diff} command
8608 works great for text files. When binary files differ, a better option
8609 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
8610 visualize differences for all kinds of files.
8612 Once you have done that work, you can tell whether the differences are due
8613 to a non-deterministic build process or to a malicious server. We try
8614 hard to remove sources of non-determinism in packages to make it easier
8615 to verify substitutes, but of course, this is a process that
8616 involves not just Guix, but a large part of the free software community.
8617 In the meantime, @command{guix challenge} is one tool to help address
8620 If you are writing packages for Guix, you are encouraged to check
8621 whether @code{hydra.gnu.org} and other substitute servers obtain the
8622 same build result as you did with:
8625 $ guix challenge @var{package}
8629 where @var{package} is a package specification such as
8630 @code{guile@@2.0} or @code{glibc:debug}.
8632 The general syntax is:
8635 guix challenge @var{options} [@var{packages}@dots{}]
8638 When a difference is found between the hash of a locally-built item and
8639 that of a server-provided substitute, or among substitutes provided by
8640 different servers, the command displays it as in the example above and
8641 its exit code is 2 (other non-zero exit codes denote other kinds of
8644 The one option that matters is:
8648 @item --substitute-urls=@var{urls}
8649 Consider @var{urls} the whitespace-separated list of substitute source
8654 Show details about matches (identical contents) in addition to
8655 information about mismatches.
8659 @node Invoking guix copy
8660 @section Invoking @command{guix copy}
8662 @cindex copy, of store items, over SSH
8663 @cindex SSH, copy of store items
8664 @cindex sharing store items across machines
8665 @cindex transferring store items across machines
8666 The @command{guix copy} command copies items from the store of one
8667 machine to that of another machine over a secure shell (SSH)
8668 connection@footnote{This command is available only when Guile-SSH was
8669 found. @xref{Requirements}, for details.}. For example, the following
8670 command copies the @code{coreutils} package, the user's profile, and all
8671 their dependencies over to @var{host}, logged in as @var{user}:
8674 guix copy --to=@var{user}@@@var{host} \
8675 coreutils `readlink -f ~/.guix-profile`
8678 If some of the items to be copied are already present on @var{host},
8679 they are not actually sent.
8681 The command below retrieves @code{libreoffice} and @code{gimp} from
8682 @var{host}, assuming they are available there:
8685 guix copy --from=@var{host} libreoffice gimp
8688 The SSH connection is established using the Guile-SSH client, which is
8689 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
8690 @file{~/.ssh/config}, and uses the SSH agent for authentication.
8692 The key used to sign items that are sent must be accepted by the remote
8693 machine. Likewise, the key used by the remote machine to sign items you
8694 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
8695 own daemon. @xref{Invoking guix archive}, for more information about
8696 store item authentication.
8698 The general syntax is:
8701 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
8704 You must always specify one of the following options:
8707 @item --to=@var{spec}
8708 @itemx --from=@var{spec}
8709 Specify the host to send to or receive from. @var{spec} must be an SSH
8710 spec such as @code{example.org}, @code{charlie@@example.org}, or
8711 @code{charlie@@example.org:2222}.
8714 The @var{items} can be either package names, such as @code{gimp}, or
8715 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
8717 When specifying the name of a package to send, it is first built if
8718 needed, unless @option{--dry-run} was specified. Common build options
8719 are supported (@pxref{Common Build Options}).
8722 @node Invoking guix container
8723 @section Invoking @command{guix container}
8725 @cindex @command{guix container}
8727 As of version @value{VERSION}, this tool is experimental. The interface
8728 is subject to radical change in the future.
8731 The purpose of @command{guix container} is to manipulate processes
8732 running within an isolated environment, commonly known as a
8733 ``container'', typically created by the @command{guix environment}
8734 (@pxref{Invoking guix environment}) and @command{guix system container}
8735 (@pxref{Invoking guix system}) commands.
8737 The general syntax is:
8740 guix container @var{action} @var{options}@dots{}
8743 @var{action} specifies the operation to perform with a container, and
8744 @var{options} specifies the context-specific arguments for the action.
8746 The following actions are available:
8750 Execute a command within the context of a running container.
8755 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
8758 @var{pid} specifies the process ID of the running container.
8759 @var{program} specifies an executable file name within the root file
8760 system of the container. @var{arguments} are the additional options that
8761 will be passed to @var{program}.
8763 The following command launches an interactive login shell inside a
8764 GuixSD container, started by @command{guix system container}, and whose
8768 guix container exec 9001 /run/current-system/profile/bin/bash --login
8771 Note that the @var{pid} cannot be the parent process of a container. It
8772 must be PID 1 of the container or one of its child processes.
8776 @node Invoking guix weather
8777 @section Invoking @command{guix weather}
8779 Occasionally you're grumpy because substitutes are lacking and you end
8780 up building packages by yourself (@pxref{Substitutes}). The
8781 @command{guix weather} command reports on substitute availability on the
8782 specified servers so you can have an idea of whether you'll be grumpy
8783 today. It can sometimes be useful info as a user, but it is primarily
8784 useful to people running @command{guix publish} (@pxref{Invoking guix
8787 @cindex statistics, for substitutes
8788 @cindex availability of substitutes
8789 @cindex substitute availability
8790 @cindex weather, substitute availability
8791 Here's a sample run:
8794 $ guix weather --substitute-urls=https://guix.example.org
8795 computing 5,872 package derivations for x86_64-linux...
8796 looking for 6,128 store items on https://guix.example.org..
8797 updating list of substitutes from 'https://guix.example.org'... 100.0%
8798 https://guix.example.org
8799 43.4% substitutes available (2,658 out of 6,128)
8800 7,032.5 MiB of nars (compressed)
8801 19,824.2 MiB on disk (uncompressed)
8802 0.030 seconds per request (182.9 seconds in total)
8803 33.5 requests per second
8805 9.8% (342 out of 3,470) of the missing items are queued
8807 x86_64-linux: 518 (59.7%)
8808 i686-linux: 221 (25.5%)
8809 aarch64-linux: 128 (14.8%)
8810 build rate: 23.41 builds per hour
8811 x86_64-linux: 11.16 builds per hour
8812 i686-linux: 6.03 builds per hour
8813 aarch64-linux: 6.41 builds per hour
8816 @cindex continuous integration, statistics
8817 As you can see, it reports the fraction of all the packages for which
8818 substitutes are available on the server---regardless of whether
8819 substitutes are enabled, and regardless of whether this server's signing
8820 key is authorized. It also reports the size of the compressed archives
8821 (``nars'') provided by the server, the size the corresponding store
8822 items occupy in the store (assuming deduplication is turned off), and
8823 the server's throughput. The second part gives continuous integration
8824 (CI) statistics, if the server supports it.
8826 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
8827 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
8828 challenge}, it ignores signatures on those substitutes, which is
8829 innocuous since the command only gathers statistics and cannot install
8832 Among other things, it is possible to query specific system types and
8833 specific package sets. The available options are listed below.
8836 @item --substitute-urls=@var{urls}
8837 @var{urls} is the space-separated list of substitute server URLs to
8838 query. When this option is omitted, the default set of substitute
8841 @item --system=@var{system}
8842 @itemx -s @var{system}
8843 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
8844 option can be repeated, in which case @command{guix weather} will query
8845 substitutes for several system types.
8847 @item --manifest=@var{file}
8848 Instead of querying substitutes for all the packages, only ask for those
8849 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
8850 with the @code{-m} option of @command{guix package} (@pxref{Invoking
8854 @node Invoking guix processes
8855 @section Invoking @command{guix processes}
8857 The @command{guix processes} command can be useful to developers and system
8858 administrators, especially on multi-user machines and on build farms: it lists
8859 the current sessions (connections to the daemon), as well as information about
8860 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
8861 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
8862 listed.}. Here's an example of the information it returns:
8865 $ sudo guix processes
8868 ClientCommand: guix environment --ad-hoc python
8872 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
8876 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
8877 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
8878 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
8879 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
8880 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
8881 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
8882 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
8885 In this example we see that @command{guix-daemon} has three clients:
8886 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
8887 integration tool; their process identifier (PID) is given by the
8888 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
8889 @command{guix-daemon} sub-process of this particular session.
8891 The @code{LockHeld} fields show which store items are currently locked by this
8892 session, which corresponds to store items being built or substituted (the
8893 @code{LockHeld} field is not displayed when @command{guix processes} is not
8894 running as root.) Last, by looking at the @code{ChildProcess} field, we
8895 understand that these three builds are being offloaded (@pxref{Daemon Offload
8898 The output is in Recutils format so we can use the handy @command{recsel}
8899 command to select sessions of interest (@pxref{Selection Expressions,,,
8900 recutils, GNU recutils manual}). As an example, the command shows the command
8901 line and PID of the client that triggered the build of a Perl package:
8904 $ sudo guix processes | \
8905 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
8907 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
8910 @c *********************************************************************
8911 @node GNU Distribution
8912 @chapter GNU Distribution
8914 @cindex Guix System Distribution
8916 Guix comes with a distribution of the GNU system consisting entirely of
8917 free software@footnote{The term ``free'' here refers to the
8918 @url{http://www.gnu.org/philosophy/free-sw.html,freedom provided to
8919 users of that software}.}. The
8920 distribution can be installed on its own (@pxref{System Installation}),
8921 but it is also possible to install Guix as a package manager on top of
8922 an installed GNU/Linux system (@pxref{Installation}). To distinguish
8923 between the two, we refer to the standalone distribution as the Guix
8924 System Distribution, or GuixSD.
8926 The distribution provides core GNU packages such as GNU libc, GCC, and
8927 Binutils, as well as many GNU and non-GNU applications. The complete
8928 list of available packages can be browsed
8929 @url{http://www.gnu.org/software/guix/packages,on-line} or by
8930 running @command{guix package} (@pxref{Invoking guix package}):
8933 guix package --list-available
8936 Our goal is to provide a practical 100% free software distribution of
8937 Linux-based and other variants of GNU, with a focus on the promotion and
8938 tight integration of GNU components, and an emphasis on programs and
8939 tools that help users exert that freedom.
8941 Packages are currently available on the following platforms:
8946 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
8949 Intel 32-bit architecture (IA32), Linux-Libre kernel;
8952 ARMv7-A architecture with hard float, Thumb-2 and NEON,
8953 using the EABI hard-float application binary interface (ABI),
8954 and Linux-Libre kernel.
8957 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel. This is
8958 currently in an experimental stage, with limited support.
8959 @xref{Contributing}, for how to help!
8961 @item mips64el-linux
8962 little-endian 64-bit MIPS processors, specifically the Loongson series,
8963 n32 ABI, and Linux-Libre kernel.
8967 GuixSD itself is currently only available on @code{i686} and @code{x86_64}.
8970 For information on porting to other architectures or kernels,
8974 * System Installation:: Installing the whole operating system.
8975 * System Configuration:: Configuring the operating system.
8976 * Documentation:: Browsing software user manuals.
8977 * Installing Debugging Files:: Feeding the debugger.
8978 * Security Updates:: Deploying security fixes quickly.
8979 * Package Modules:: Packages from the programmer's viewpoint.
8980 * Packaging Guidelines:: Growing the distribution.
8981 * Bootstrapping:: GNU/Linux built from scratch.
8982 * Porting:: Targeting another platform or kernel.
8985 Building this distribution is a cooperative effort, and you are invited
8986 to join! @xref{Contributing}, for information about how you can help.
8988 @node System Installation
8989 @section System Installation
8991 @cindex installing GuixSD
8992 @cindex Guix System Distribution
8993 This section explains how to install the Guix System Distribution (GuixSD)
8994 on a machine. The Guix package manager can
8995 also be installed on top of a running GNU/Linux system,
8996 @pxref{Installation}.
9000 @c This paragraph is for people reading this from tty2 of the
9001 @c installation image.
9002 You are reading this documentation with an Info reader. For details on
9003 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
9004 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
9005 Info}. Hit @kbd{l} afterwards to come back here.
9007 Alternately, run @command{info info} in another tty to keep the manual
9013 * Limitations:: What you can expect.
9014 * Hardware Considerations:: Supported hardware.
9015 * USB Stick and DVD Installation:: Preparing the installation medium.
9016 * Preparing for Installation:: Networking, partitioning, etc.
9017 * Proceeding with the Installation:: The real thing.
9018 * Installing GuixSD in a VM:: GuixSD playground.
9019 * Building the Installation Image:: How this comes to be.
9023 @subsection Limitations
9025 As of version @value{VERSION}, the Guix System Distribution (GuixSD) is
9026 not production-ready. It may contain bugs and lack important
9027 features. Thus, if you are looking for a stable production system that
9028 respects your freedom as a computer user, a good solution at this point
9029 is to consider @url{http://www.gnu.org/distros/free-distros.html, one of
9030 the more established GNU/Linux distributions}. We hope you can soon switch
9031 to the GuixSD without fear, of course. In the meantime, you can
9032 also keep using your distribution and try out the package manager on top
9033 of it (@pxref{Installation}).
9035 Before you proceed with the installation, be aware of the following
9036 noteworthy limitations applicable to version @value{VERSION}:
9040 The installation process does not include a graphical user interface and
9041 requires familiarity with GNU/Linux (see the following subsections to
9042 get a feel of what that means.)
9045 Support for the Logical Volume Manager (LVM) is missing.
9048 More and more system services are provided (@pxref{Services}), but some
9052 More than 7,500 packages are available, but you might
9053 occasionally find that a useful package is missing.
9056 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
9057 as well as a number of X11 window managers. However, some graphical
9058 applications may be missing, as well as KDE.
9061 You have been warned! But more than a disclaimer, this is an invitation
9062 to report issues (and success stories!), and to join us in improving it.
9063 @xref{Contributing}, for more info.
9066 @node Hardware Considerations
9067 @subsection Hardware Considerations
9069 @cindex hardware support on GuixSD
9070 GNU@tie{}GuixSD focuses on respecting the user's computing freedom. It
9071 builds around the kernel Linux-libre, which means that only hardware for
9072 which free software drivers and firmware exist is supported. Nowadays,
9073 a wide range of off-the-shelf hardware is supported on
9074 GNU/Linux-libre---from keyboards to graphics cards to scanners and
9075 Ethernet controllers. Unfortunately, there are still areas where
9076 hardware vendors deny users control over their own computing, and such
9077 hardware is not supported on GuixSD.
9079 @cindex WiFi, hardware support
9080 One of the main areas where free drivers or firmware are lacking is WiFi
9081 devices. WiFi devices known to work include those using Atheros chips
9082 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
9083 driver, and those using Broadcom/AirForce chips (BCM43xx with
9084 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
9085 Linux-libre driver. Free firmware exists for both and is available
9086 out-of-the-box on GuixSD, as part of @var{%base-firmware}
9087 (@pxref{operating-system Reference, @code{firmware}}).
9089 @cindex RYF, Respects Your Freedom
9090 The @uref{https://www.fsf.org/, Free Software Foundation} runs
9091 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
9092 certification program for hardware products that respect your freedom
9093 and your privacy and ensure that you have control over your device. We
9094 encourage you to check the list of RYF-certified devices.
9096 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
9097 web site. It contains a catalog of hardware devices with information
9098 about their support in GNU/Linux.
9101 @node USB Stick and DVD Installation
9102 @subsection USB Stick and DVD Installation
9104 An ISO-9660 installation image that can be written to a USB stick or
9105 burnt to a DVD can be downloaded from
9106 @indicateurl{https://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.iso.xz},
9107 where @var{system} is one of:
9111 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
9114 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
9117 @c start duplication of authentication part from ``Binary Installation''
9118 Make sure to download the associated @file{.sig} file and to verify the
9119 authenticity of the image against it, along these lines:
9122 $ wget https://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.iso.xz.sig
9123 $ gpg --verify guixsd-install-@value{VERSION}.@var{system}.iso.xz.sig
9126 If that command fails because you do not have the required public key,
9127 then run this command to import it:
9130 $ gpg --keyserver @value{KEY-SERVER} \
9131 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9135 and rerun the @code{gpg --verify} command.
9138 This image contains the tools necessary for an installation.
9139 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
9141 @unnumberedsubsubsec Copying to a USB Stick
9143 To copy the image to a USB stick, follow these steps:
9147 Decompress the image using the @command{xz} command:
9150 xz -d guixsd-install-@value{VERSION}.@var{system}.iso.xz
9154 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
9155 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
9156 copy the image with:
9159 dd if=guixsd-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX
9163 Access to @file{/dev/sdX} usually requires root privileges.
9166 @unnumberedsubsubsec Burning on a DVD
9168 To copy the image to a DVD, follow these steps:
9172 Decompress the image using the @command{xz} command:
9175 xz -d guixsd-install-@value{VERSION}.@var{system}.iso.xz
9179 Insert a blank DVD into your machine, and determine
9180 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
9181 copy the image with:
9184 growisofs -dvd-compat -Z /dev/srX=guixsd-install-@value{VERSION}.x86_64.iso
9187 Access to @file{/dev/srX} usually requires root privileges.
9190 @unnumberedsubsubsec Booting
9192 Once this is done, you should be able to reboot the system and boot from
9193 the USB stick or DVD. The latter usually requires you to get in the
9194 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
9196 @xref{Installing GuixSD in a VM}, if, instead, you would like to install
9197 GuixSD in a virtual machine (VM).
9200 @node Preparing for Installation
9201 @subsection Preparing for Installation
9203 Once you have successfully booted your computer using the installation medium,
9204 you should end up with a root prompt. Several console TTYs are configured
9205 and can be used to run commands as root. TTY2 shows this documentation,
9206 browsable using the Info reader commands (@pxref{Top,,, info-stnd,
9207 Stand-alone GNU Info}). The installation system runs the GPM mouse
9208 daemon, which allows you to select text with the left mouse button and
9209 to paste it with the middle button.
9212 Installation requires access to the Internet so that any missing
9213 dependencies of your system configuration can be downloaded. See the
9214 ``Networking'' section below.
9217 The installation system includes many common tools needed for this task.
9218 But it is also a full-blown GuixSD system, which means that you can
9219 install additional packages, should you need it, using @command{guix
9220 package} (@pxref{Invoking guix package}).
9222 @subsubsection Keyboard Layout
9224 @cindex keyboard layout
9225 The installation image uses the US qwerty keyboard layout. If you want
9226 to change it, you can use the @command{loadkeys} command. For example,
9227 the following command selects the Dvorak keyboard layout:
9233 See the files under @file{/run/current-system/profile/share/keymaps} for
9234 a list of available keyboard layouts. Run @command{man loadkeys} for
9237 @subsubsection Networking
9239 Run the following command to see what your network interfaces are called:
9246 @dots{} or, using the GNU/Linux-specific @command{ip} command:
9252 @c http://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
9253 Wired interfaces have a name starting with @samp{e}; for example, the
9254 interface corresponding to the first on-board Ethernet controller is
9255 called @samp{eno1}. Wireless interfaces have a name starting with
9256 @samp{w}, like @samp{w1p2s0}.
9259 @item Wired connection
9260 To configure a wired network run the following command, substituting
9261 @var{interface} with the name of the wired interface you want to use.
9264 ifconfig @var{interface} up
9267 @item Wireless connection
9270 To configure wireless networking, you can create a configuration file
9271 for the @command{wpa_supplicant} configuration tool (its location is not
9272 important) using one of the available text editors such as
9276 nano wpa_supplicant.conf
9279 As an example, the following stanza can go to this file and will work
9280 for many wireless networks, provided you give the actual SSID and
9281 passphrase for the network you are connecting to:
9285 ssid="@var{my-ssid}"
9287 psk="the network's secret passphrase"
9291 Start the wireless service and run it in the background with the
9292 following command (substitute @var{interface} with the name of the
9293 network interface you want to use):
9296 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
9299 Run @command{man wpa_supplicant} for more information.
9303 At this point, you need to acquire an IP address. On a network where IP
9304 addresses are automatically assigned @i{via} DHCP, you can run:
9307 dhclient -v @var{interface}
9310 Try to ping a server to see if networking is up and running:
9316 Setting up network access is almost always a requirement because the
9317 image does not contain all the software and tools that may be needed.
9319 @cindex installing over SSH
9320 If you want to, you can continue the installation remotely by starting
9324 herd start ssh-daemon
9327 Make sure to either set a password with @command{passwd}, or configure
9328 OpenSSH public key authentication before logging in.
9330 @subsubsection Disk Partitioning
9332 Unless this has already been done, the next step is to partition, and
9333 then format the target partition(s).
9335 The installation image includes several partitioning tools, including
9336 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
9337 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
9338 the partition layout you want:
9344 If your disk uses the GUID Partition Table (GPT) format and you plan to
9345 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
9346 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
9349 @cindex EFI, installation
9350 @cindex UEFI, installation
9351 @cindex ESP, EFI system partition
9352 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
9353 (ESP) is required. This partition should be mounted at @file{/boot/efi} and
9354 must have the @code{esp} flag set. E.g., for @command{parted}:
9357 parted /dev/sda set 1 esp on
9361 @vindex grub-bootloader
9362 @vindex grub-efi-bootloader
9363 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
9364 @file{/sys/firmware/efi} exists in the installation image, then you should
9365 probably perform an EFI installation, using @code{grub-efi-bootloader}.
9366 Otherwise you should use the BIOS-based GRUB, known as
9367 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
9371 Once you are done partitioning the target hard disk drive, you have to
9372 create a file system on the relevant partition(s)@footnote{Currently
9373 GuixSD only supports ext4 and btrfs file systems. In particular, code
9374 that reads file system UUIDs and labels only works for these file system
9375 types.}. For the ESP, if you have one and assuming it is
9376 @file{/dev/sda1}, run:
9379 mkfs.fat -F32 /dev/sda1
9382 Preferably, assign file systems a label so that you can easily and
9383 reliably refer to them in @code{file-system} declarations (@pxref{File
9384 Systems}). This is typically done using the @code{-L} option of
9385 @command{mkfs.ext4} and related commands. So, assuming the target root
9386 partition lives at @file{/dev/sda2}, a file system with the label
9387 @code{my-root} can be created with:
9390 mkfs.ext4 -L my-root /dev/sda2
9393 @cindex encrypted disk
9394 If you are instead planning to encrypt the root partition, you can use
9395 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
9396 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
9397 @code{man cryptsetup}} for more information.) Assuming you want to
9398 store the root partition on @file{/dev/sda2}, the command sequence would
9399 be along these lines:
9402 cryptsetup luksFormat /dev/sda2
9403 cryptsetup open --type luks /dev/sda2 my-partition
9404 mkfs.ext4 -L my-root /dev/mapper/my-partition
9407 Once that is done, mount the target file system under @file{/mnt}
9408 with a command like (again, assuming @code{my-root} is the label of the
9412 mount LABEL=my-root /mnt
9415 Also mount any other file systems you would like to use on the target
9416 system relative to this path. If you have @file{/boot} on a separate
9417 partition for example, mount it at @file{/mnt/boot} now so it is found
9418 by @code{guix system init} afterwards.
9420 Finally, if you plan to use one or more swap partitions (@pxref{Memory
9421 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
9422 sure to initialize them with @command{mkswap}. Assuming you have one
9423 swap partition on @file{/dev/sda3}, you would run:
9430 Alternatively, you may use a swap file. For example, assuming that in
9431 the new system you want to use the file @file{/swapfile} as a swap file,
9432 you would run@footnote{This example will work for many types of file
9433 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
9434 btrfs), the required steps may be different. For details, see the
9435 manual pages for @command{mkswap} and @command{swapon}.}:
9438 # This is 10 GiB of swap space. Adjust "count" to change the size.
9439 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
9440 # For security, make the file readable and writable only by root.
9441 chmod 600 /mnt/swapfile
9442 mkswap /mnt/swapfile
9443 swapon /mnt/swapfile
9446 Note that if you have encrypted the root partition and created a swap
9447 file in its file system as described above, then the encryption also
9448 protects the swap file, just like any other file in that file system.
9450 @node Proceeding with the Installation
9451 @subsection Proceeding with the Installation
9453 With the target partitions ready and the target root mounted on
9454 @file{/mnt}, we're ready to go. First, run:
9457 herd start cow-store /mnt
9460 This makes @file{/gnu/store} copy-on-write, such that packages added to it
9461 during the installation phase are written to the target disk on @file{/mnt}
9462 rather than kept in memory. This is necessary because the first phase of
9463 the @command{guix system init} command (see below) entails downloads or
9464 builds to @file{/gnu/store} which, initially, is an in-memory file system.
9466 Next, you have to edit a file and
9467 provide the declaration of the operating system to be installed. To
9468 that end, the installation system comes with three text editors. We
9469 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
9470 supports syntax highlighting and parentheses matching; other editors
9471 include GNU Zile (an Emacs clone), and
9472 nvi (a clone of the original BSD @command{vi} editor).
9473 We strongly recommend storing that file on the target root file system, say,
9474 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
9475 configuration file once you have rebooted into the newly-installed system.
9477 @xref{Using the Configuration System}, for an overview of the
9478 configuration file. The example configurations discussed in that
9479 section are available under @file{/etc/configuration} in the
9480 installation image. Thus, to get started with a system configuration
9481 providing a graphical display server (a ``desktop'' system), you can run
9482 something along these lines:
9486 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
9487 # nano /mnt/etc/config.scm
9490 You should pay attention to what your configuration file contains, and
9495 Make sure the @code{bootloader-configuration} form refers to the target
9496 you want to install GRUB on. It should mention @code{grub-bootloader} if
9497 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
9498 for newer UEFI systems. For legacy systems, the @code{target} field
9499 names a device, like @code{/dev/sda}; for UEFI systems it names a path
9500 to a mounted EFI partition, like @code{/boot/efi}, and do make sure the
9501 path is actually mounted.
9504 Be sure that your file system labels match the value of their respective
9505 @code{device} fields in your @code{file-system} configuration, assuming
9506 your @code{file-system} configuration uses the @code{file-system-label}
9507 procedure in its @code{device} field.
9510 If there are encrypted or RAID partitions, make sure to add a
9511 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
9514 Once you are done preparing the configuration file, the new system must
9515 be initialized (remember that the target root file system is mounted
9519 guix system init /mnt/etc/config.scm /mnt
9523 This copies all the necessary files and installs GRUB on
9524 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
9525 more information, @pxref{Invoking guix system}. This command may trigger
9526 downloads or builds of missing packages, which can take some time.
9528 Once that command has completed---and hopefully succeeded!---you can run
9529 @command{reboot} and boot into the new system. The @code{root} password
9530 in the new system is initially empty; other users' passwords need to be
9531 initialized by running the @command{passwd} command as @code{root},
9532 unless your configuration specifies otherwise
9533 (@pxref{user-account-password, user account passwords}).
9535 @cindex upgrading GuixSD
9536 From then on, you can update GuixSD whenever you want by running
9537 @command{guix pull} as @code{root} (@pxref{Invoking guix pull}), and
9538 then running @command{guix system reconfigure} to build a new system
9539 generation with the latest packages and services (@pxref{Invoking guix
9540 system}). We recommend doing that regularly so that your system
9541 includes the latest security updates (@pxref{Security Updates}).
9543 Join us on @code{#guix} on the Freenode IRC network or on
9544 @file{guix-devel@@gnu.org} to share your experience---good or not so
9547 @node Installing GuixSD in a VM
9548 @subsection Installing GuixSD in a Virtual Machine
9550 @cindex virtual machine, GuixSD installation
9551 @cindex virtual private server (VPS)
9552 @cindex VPS (virtual private server)
9553 If you'd like to install GuixSD in a virtual machine (VM) or on a
9554 virtual private server (VPS) rather than on your beloved machine, this
9557 To boot a @uref{http://qemu.org/,QEMU} VM for installing GuixSD in a
9558 disk image, follow these steps:
9562 First, retrieve and decompress the GuixSD installation image as
9563 described previously (@pxref{USB Stick and DVD Installation}).
9566 Create a disk image that will hold the installed system. To make a
9567 qcow2-formatted disk image, use the @command{qemu-img} command:
9570 qemu-img create -f qcow2 guixsd.img 50G
9573 The resulting file will be much smaller than 50 GB (typically less than
9574 1 MB), but it will grow as the virtualized storage device is filled up.
9577 Boot the USB installation image in an VM:
9580 qemu-system-x86_64 -m 1024 -smp 1 \
9581 -net user -net nic,model=virtio -boot menu=on \
9582 -drive file=guixsd-install-@value{VERSION}.@var{system}.iso \
9583 -drive file=guixsd.img
9586 The ordering of the drives matters.
9588 In the VM console, quickly press the @kbd{F12} key to enter the boot
9589 menu. Then press the @kbd{2} key and the @kbd{RET} key to validate your
9593 You're now root in the VM, proceed with the installation process.
9594 @xref{Preparing for Installation}, and follow the instructions.
9597 Once installation is complete, you can boot the system that's on your
9598 @file{guixsd.img} image. @xref{Running GuixSD in a VM}, for how to do
9601 @node Building the Installation Image
9602 @subsection Building the Installation Image
9604 @cindex installation image
9605 The installation image described above was built using the @command{guix
9606 system} command, specifically:
9609 guix system disk-image gnu/system/install.scm
9612 Have a look at @file{gnu/system/install.scm} in the source tree,
9613 and see also @ref{Invoking guix system} for more information
9614 about the installation image.
9616 @subsection Building the Installation Image for ARM Boards
9618 Many ARM boards require a specific variant of the
9619 @uref{http://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
9621 If you build a disk image and the bootloader is not available otherwise
9622 (on another boot drive etc), it's advisable to build an image that
9623 includes the bootloader, specifically:
9626 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
9629 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
9630 board, a list of possible boards will be printed.
9632 @node System Configuration
9633 @section System Configuration
9635 @cindex system configuration
9636 The Guix System Distribution supports a consistent whole-system configuration
9637 mechanism. By that we mean that all aspects of the global system
9638 configuration---such as the available system services, timezone and
9639 locale settings, user accounts---are declared in a single place. Such
9640 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
9642 One of the advantages of putting all the system configuration under the
9643 control of Guix is that it supports transactional system upgrades, and
9644 makes it possible to roll back to a previous system instantiation,
9645 should something go wrong with the new one (@pxref{Features}). Another
9646 advantage is that it makes it easy to replicate the exact same configuration
9647 across different machines, or at different points in time, without
9648 having to resort to additional administration tools layered on top of
9649 the own tools of the system.
9650 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
9652 This section describes this mechanism. First we focus on the system
9653 administrator's viewpoint---explaining how the system is configured and
9654 instantiated. Then we show how this mechanism can be extended, for
9655 instance to support new system services.
9658 * Using the Configuration System:: Customizing your GNU system.
9659 * operating-system Reference:: Detail of operating-system declarations.
9660 * File Systems:: Configuring file system mounts.
9661 * Mapped Devices:: Block device extra processing.
9662 * User Accounts:: Specifying user accounts.
9663 * Locales:: Language and cultural convention settings.
9664 * Services:: Specifying system services.
9665 * Setuid Programs:: Programs running with root privileges.
9666 * X.509 Certificates:: Authenticating HTTPS servers.
9667 * Name Service Switch:: Configuring libc's name service switch.
9668 * Initial RAM Disk:: Linux-Libre bootstrapping.
9669 * Bootloader Configuration:: Configuring the boot loader.
9670 * Invoking guix system:: Instantiating a system configuration.
9671 * Running GuixSD in a VM:: How to run GuixSD in a virtual machine.
9672 * Defining Services:: Adding new service definitions.
9675 @node Using the Configuration System
9676 @subsection Using the Configuration System
9678 The operating system is configured by providing an
9679 @code{operating-system} declaration in a file that can then be passed to
9680 the @command{guix system} command (@pxref{Invoking guix system}). A
9681 simple setup, with the default system services, the default Linux-Libre
9682 kernel, initial RAM disk, and boot loader looks like this:
9684 @findex operating-system
9686 @include os-config-bare-bones.texi
9689 This example should be self-describing. Some of the fields defined
9690 above, such as @code{host-name} and @code{bootloader}, are mandatory.
9691 Others, such as @code{packages} and @code{services}, can be omitted, in
9692 which case they get a default value.
9694 Below we discuss the effect of some of the most important fields
9695 (@pxref{operating-system Reference}, for details about all the available
9696 fields), and how to @dfn{instantiate} the operating system using
9697 @command{guix system}.
9699 @unnumberedsubsubsec Bootloader
9701 @cindex legacy boot, on Intel machines
9702 @cindex BIOS boot, on Intel machines
9705 The @code{bootloader} field describes the method that will be used to boot
9706 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
9707 mode, as in the example above. However, more recent machines rely instead on
9708 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
9709 the @code{bootloader} field should contain something along these lines:
9712 (bootloader-configuration
9713 (bootloader grub-efi-bootloader)
9714 (target "/boot/efi"))
9717 @xref{Bootloader Configuration}, for more information on the available
9718 configuration options.
9720 @unnumberedsubsubsec Globally-Visible Packages
9722 @vindex %base-packages
9723 The @code{packages} field lists packages that will be globally visible
9724 on the system, for all user accounts---i.e., in every user's @code{PATH}
9725 environment variable---in addition to the per-user profiles
9726 (@pxref{Invoking guix package}). The @var{%base-packages} variable
9727 provides all the tools one would expect for basic user and administrator
9728 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
9729 the GNU Zile lightweight text editor, @command{find}, @command{grep},
9730 etc. The example above adds GNU@tie{}Screen to those,
9731 taken from the @code{(gnu packages screen)}
9732 module (@pxref{Package Modules}). The
9733 @code{(list package output)} syntax can be used to add a specific output
9737 (use-modules (gnu packages))
9738 (use-modules (gnu packages dns))
9742 (packages (cons (list bind "utils")
9746 @findex specification->package
9747 Referring to packages by variable name, like @code{bind} above, has
9748 the advantage of being unambiguous; it also allows typos and such to be
9749 diagnosed right away as ``unbound variables''. The downside is that one
9750 needs to know which module defines which package, and to augment the
9751 @code{use-package-modules} line accordingly. To avoid that, one can use
9752 the @code{specification->package} procedure of the @code{(gnu packages)}
9753 module, which returns the best package for a given name or name and
9757 (use-modules (gnu packages))
9761 (packages (append (map specification->package
9762 '("tcpdump" "htop" "gnupg@@2.0"))
9766 @unnumberedsubsubsec System Services
9769 @vindex %base-services
9770 The @code{services} field lists @dfn{system services} to be made
9771 available when the system starts (@pxref{Services}).
9772 The @code{operating-system} declaration above specifies that, in
9773 addition to the basic services, we want the @command{lshd} secure shell
9774 daemon listening on port 2222 (@pxref{Networking Services,
9775 @code{lsh-service}}). Under the hood,
9776 @code{lsh-service} arranges so that @code{lshd} is started with the
9777 right command-line options, possibly with supporting configuration files
9778 generated as needed (@pxref{Defining Services}).
9780 @cindex customization, of services
9781 @findex modify-services
9782 Occasionally, instead of using the base services as is, you will want to
9783 customize them. To do this, use @code{modify-services} (@pxref{Service
9784 Reference, @code{modify-services}}) to modify the list.
9786 For example, suppose you want to modify @code{guix-daemon} and Mingetty
9787 (the console log-in) in the @var{%base-services} list (@pxref{Base
9788 Services, @code{%base-services}}). To do that, you can write the
9789 following in your operating system declaration:
9792 (define %my-services
9793 ;; My very own list of services.
9794 (modify-services %base-services
9795 (guix-service-type config =>
9798 (use-substitutes? #f)
9799 (extra-options '("--gc-keep-derivations"))))
9800 (mingetty-service-type config =>
9801 (mingetty-configuration
9802 (inherit config)))))
9806 (services %my-services))
9809 This changes the configuration---i.e., the service parameters---of the
9810 @code{guix-service-type} instance, and that of all the
9811 @code{mingetty-service-type} instances in the @var{%base-services} list.
9812 Observe how this is accomplished: first, we arrange for the original
9813 configuration to be bound to the identifier @code{config} in the
9814 @var{body}, and then we write the @var{body} so that it evaluates to the
9815 desired configuration. In particular, notice how we use @code{inherit}
9816 to create a new configuration which has the same values as the old
9817 configuration, but with a few modifications.
9819 @cindex encrypted disk
9820 The configuration for a typical ``desktop'' usage, with an encrypted
9821 root partition, the X11 display
9822 server, GNOME and Xfce (users can choose which of these desktop
9823 environments to use at the log-in screen by pressing @kbd{F1}), network
9824 management, power management, and more, would look like this:
9827 @include os-config-desktop.texi
9830 A graphical system with a choice of lightweight window managers
9831 instead of full-blown desktop environments would look like this:
9834 @include os-config-lightweight-desktop.texi
9837 This example refers to the @file{/boot/efi} file system by its UUID,
9838 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
9839 as returned by the @command{blkid} command.
9841 @xref{Desktop Services}, for the exact list of services provided by
9842 @var{%desktop-services}. @xref{X.509 Certificates}, for background
9843 information about the @code{nss-certs} package that is used here.
9845 Again, @var{%desktop-services} is just a list of service objects. If
9846 you want to remove services from there, you can do so using the
9847 procedures for list filtering (@pxref{SRFI-1 Filtering and
9848 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
9849 following expression returns a list that contains all the services in
9850 @var{%desktop-services} minus the Avahi service:
9853 (remove (lambda (service)
9854 (eq? (service-kind service) avahi-service-type))
9858 @unnumberedsubsubsec Instantiating the System
9860 Assuming the @code{operating-system} declaration
9861 is stored in the @file{my-system-config.scm}
9862 file, the @command{guix system reconfigure my-system-config.scm} command
9863 instantiates that configuration, and makes it the default GRUB boot
9864 entry (@pxref{Invoking guix system}).
9866 The normal way to change the system configuration is by updating this
9867 file and re-running @command{guix system reconfigure}. One should never
9868 have to touch files in @file{/etc} or to run commands that modify the
9869 system state such as @command{useradd} or @command{grub-install}. In
9870 fact, you must avoid that since that would not only void your warranty
9871 but also prevent you from rolling back to previous versions of your
9872 system, should you ever need to.
9874 @cindex roll-back, of the operating system
9875 Speaking of roll-back, each time you run @command{guix system
9876 reconfigure}, a new @dfn{generation} of the system is created---without
9877 modifying or deleting previous generations. Old system generations get
9878 an entry in the bootloader boot menu, allowing you to boot them in case
9879 something went wrong with the latest generation. Reassuring, no? The
9880 @command{guix system list-generations} command lists the system
9881 generations available on disk. It is also possible to roll back the
9882 system via the commands @command{guix system roll-back} and
9883 @command{guix system switch-generation}.
9885 Although the @command{guix system reconfigure} command will not modify
9886 previous generations, you must take care when the current generation is not
9887 the latest (e.g., after invoking @command{guix system roll-back}), since
9888 the operation might overwrite a later generation (@pxref{Invoking guix
9891 @unnumberedsubsubsec The Programming Interface
9893 At the Scheme level, the bulk of an @code{operating-system} declaration
9894 is instantiated with the following monadic procedure (@pxref{The Store
9897 @deffn {Monadic Procedure} operating-system-derivation os
9898 Return a derivation that builds @var{os}, an @code{operating-system}
9899 object (@pxref{Derivations}).
9901 The output of the derivation is a single directory that refers to all
9902 the packages, configuration files, and other supporting files needed to
9903 instantiate @var{os}.
9906 This procedure is provided by the @code{(gnu system)} module. Along
9907 with @code{(gnu services)} (@pxref{Services}), this module contains the
9908 guts of GuixSD. Make sure to visit it!
9911 @node operating-system Reference
9912 @subsection @code{operating-system} Reference
9914 This section summarizes all the options available in
9915 @code{operating-system} declarations (@pxref{Using the Configuration
9918 @deftp {Data Type} operating-system
9919 This is the data type representing an operating system configuration.
9920 By that, we mean all the global system configuration, not per-user
9921 configuration (@pxref{Using the Configuration System}).
9924 @item @code{kernel} (default: @var{linux-libre})
9925 The package object of the operating system kernel to use@footnote{Currently
9926 only the Linux-libre kernel is supported. In the future, it will be
9927 possible to use the GNU@tie{}Hurd.}.
9929 @item @code{kernel-arguments} (default: @code{'()})
9930 List of strings or gexps representing additional arguments to pass on
9931 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
9933 @item @code{bootloader}
9934 The system bootloader configuration object. @xref{Bootloader Configuration}.
9936 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
9938 @cindex initial RAM disk
9939 The list of Linux kernel modules that need to be available in the
9940 initial RAM disk. @xref{Initial RAM Disk}.
9942 @item @code{initrd} (default: @code{base-initrd})
9943 A procedure that returns an initial RAM disk for the Linux
9944 kernel. This field is provided to support low-level customization and
9945 should rarely be needed for casual use. @xref{Initial RAM Disk}.
9947 @item @code{firmware} (default: @var{%base-firmware})
9949 List of firmware packages loadable by the operating system kernel.
9951 The default includes firmware needed for Atheros- and Broadcom-based
9952 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
9953 respectively). @xref{Hardware Considerations}, for more info on
9956 @item @code{host-name}
9959 @item @code{hosts-file}
9961 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
9962 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
9963 Reference Manual}). The default is a file with entries for
9964 @code{localhost} and @var{host-name}.
9966 @item @code{mapped-devices} (default: @code{'()})
9967 A list of mapped devices. @xref{Mapped Devices}.
9969 @item @code{file-systems}
9970 A list of file systems. @xref{File Systems}.
9972 @item @code{swap-devices} (default: @code{'()})
9973 @cindex swap devices
9974 A list of strings identifying devices or files to be used for ``swap
9975 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
9976 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
9977 It is possible to specify a swap file in a file system on a mapped
9978 device, provided that the necessary device mapping and file system are
9979 also specified. @xref{Mapped Devices} and @ref{File Systems}.
9981 @item @code{users} (default: @code{%base-user-accounts})
9982 @itemx @code{groups} (default: @var{%base-groups})
9983 List of user accounts and groups. @xref{User Accounts}.
9985 If the @code{users} list lacks a user account with UID@tie{}0, a
9986 ``root'' account with UID@tie{}0 is automatically added.
9988 @item @code{skeletons} (default: @code{(default-skeletons)})
9989 A list target file name/file-like object tuples (@pxref{G-Expressions,
9990 file-like objects}). These are the skeleton files that will be added to
9991 the home directory of newly-created user accounts.
9993 For instance, a valid value may look like this:
9996 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
9997 (".guile" ,(plain-file "guile"
9998 "(use-modules (ice-9 readline))
9999 (activate-readline)")))
10002 @item @code{issue} (default: @var{%default-issue})
10003 A string denoting the contents of the @file{/etc/issue} file, which is
10004 displayed when users log in on a text console.
10006 @item @code{packages} (default: @var{%base-packages})
10007 The set of packages installed in the global profile, which is accessible
10008 at @file{/run/current-system/profile}.
10010 The default set includes core utilities and it is good practice to
10011 install non-core utilities in user profiles (@pxref{Invoking guix
10014 @item @code{timezone}
10015 A timezone identifying string---e.g., @code{"Europe/Paris"}.
10017 You can run the @command{tzselect} command to find out which timezone
10018 string corresponds to your region. Choosing an invalid timezone name
10019 causes @command{guix system} to fail.
10021 @item @code{locale} (default: @code{"en_US.utf8"})
10022 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
10023 Library Reference Manual}). @xref{Locales}, for more information.
10025 @item @code{locale-definitions} (default: @var{%default-locale-definitions})
10026 The list of locale definitions to be compiled and that may be used at
10027 run time. @xref{Locales}.
10029 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
10030 The list of GNU@tie{}libc packages whose locale data and tools are used
10031 to build the locale definitions. @xref{Locales}, for compatibility
10032 considerations that justify this option.
10034 @item @code{name-service-switch} (default: @var{%default-nss})
10035 Configuration of the libc name service switch (NSS)---a
10036 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
10039 @item @code{services} (default: @var{%base-services})
10040 A list of service objects denoting system services. @xref{Services}.
10042 @item @code{pam-services} (default: @code{(base-pam-services)})
10044 @cindex pluggable authentication modules
10045 Linux @dfn{pluggable authentication module} (PAM) services.
10046 @c FIXME: Add xref to PAM services section.
10048 @item @code{setuid-programs} (default: @var{%setuid-programs})
10049 List of string-valued G-expressions denoting setuid programs.
10050 @xref{Setuid Programs}.
10052 @item @code{sudoers-file} (default: @var{%sudoers-specification})
10053 @cindex sudoers file
10054 The contents of the @file{/etc/sudoers} file as a file-like object
10055 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
10057 This file specifies which users can use the @command{sudo} command, what
10058 they are allowed to do, and what privileges they may gain. The default
10059 is that only @code{root} and members of the @code{wheel} group may use
10066 @subsection File Systems
10068 The list of file systems to be mounted is specified in the
10069 @code{file-systems} field of the operating system declaration
10070 (@pxref{Using the Configuration System}). Each file system is declared
10071 using the @code{file-system} form, like this:
10075 (mount-point "/home")
10076 (device "/dev/sda3")
10080 As usual, some of the fields are mandatory---those shown in the example
10081 above---while others can be omitted. These are described below.
10083 @deftp {Data Type} file-system
10084 Objects of this type represent file systems to be mounted. They
10085 contain the following members:
10089 This is a string specifying the type of the file system---e.g.,
10092 @item @code{mount-point}
10093 This designates the place where the file system is to be mounted.
10095 @item @code{device}
10096 This names the ``source'' of the file system. It can be one of three
10097 things: a file system label, a file system UUID, or the name of a
10098 @file{/dev} node. Labels and UUIDs offer a way to refer to file
10099 systems without having to hard-code their actual device
10100 name@footnote{Note that, while it is tempting to use
10101 @file{/dev/disk/by-uuid} and similar device names to achieve the same
10102 result, this is not recommended: These special device nodes are created
10103 by the udev daemon and may be unavailable at the time the device is
10106 @findex file-system-label
10107 File system labels are created using the @code{file-system-label}
10108 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
10109 plain strings. Here's an example of a file system referred to by its
10110 label, as shown by the @command{e2label} command:
10114 (mount-point "/home")
10116 (device (file-system-label "my-home")))
10120 UUIDs are converted from their string representation (as shown by the
10121 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
10122 @code{uuid} form expects 16-byte UUIDs as defined in
10123 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
10124 form of UUID used by the ext2 family of file systems and others, but it
10125 is different from ``UUIDs'' found in FAT file systems, for instance.},
10130 (mount-point "/home")
10132 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
10135 When the source of a file system is a mapped device (@pxref{Mapped
10136 Devices}), its @code{device} field @emph{must} refer to the mapped
10137 device name---e.g., @file{"/dev/mapper/root-partition"}.
10138 This is required so that
10139 the system knows that mounting the file system depends on having the
10140 corresponding device mapping established.
10142 @item @code{flags} (default: @code{'()})
10143 This is a list of symbols denoting mount flags. Recognized flags
10144 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
10145 access to special files), @code{no-suid} (ignore setuid and setgid
10146 bits), and @code{no-exec} (disallow program execution.)
10148 @item @code{options} (default: @code{#f})
10149 This is either @code{#f}, or a string denoting mount options.
10151 @item @code{mount?} (default: @code{#t})
10152 This value indicates whether to automatically mount the file system when
10153 the system is brought up. When set to @code{#f}, the file system gets
10154 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
10155 is not automatically mounted.
10157 @item @code{needed-for-boot?} (default: @code{#f})
10158 This Boolean value indicates whether the file system is needed when
10159 booting. If that is true, then the file system is mounted when the
10160 initial RAM disk (initrd) is loaded. This is always the case, for
10161 instance, for the root file system.
10163 @item @code{check?} (default: @code{#t})
10164 This Boolean indicates whether the file system needs to be checked for
10165 errors before being mounted.
10167 @item @code{create-mount-point?} (default: @code{#f})
10168 When true, the mount point is created if it does not exist yet.
10170 @item @code{dependencies} (default: @code{'()})
10171 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
10172 representing file systems that must be mounted or mapped devices that
10173 must be opened before (and unmounted or closed after) this one.
10175 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
10176 a dependency of @file{/sys/fs/cgroup/cpu} and
10177 @file{/sys/fs/cgroup/memory}.
10179 Another example is a file system that depends on a mapped device, for
10180 example for an encrypted partition (@pxref{Mapped Devices}).
10184 The @code{(gnu system file-systems)} exports the following useful
10187 @defvr {Scheme Variable} %base-file-systems
10188 These are essential file systems that are required on normal systems,
10189 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
10190 below.) Operating system declarations should always contain at least
10194 @defvr {Scheme Variable} %pseudo-terminal-file-system
10195 This is the file system to be mounted as @file{/dev/pts}. It supports
10196 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
10197 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
10198 Manual}). Pseudo-terminals are used by terminal emulators such as
10202 @defvr {Scheme Variable} %shared-memory-file-system
10203 This file system is mounted as @file{/dev/shm} and is used to support
10204 memory sharing across processes (@pxref{Memory-mapped I/O,
10205 @code{shm_open},, libc, The GNU C Library Reference Manual}).
10208 @defvr {Scheme Variable} %immutable-store
10209 This file system performs a read-only ``bind mount'' of
10210 @file{/gnu/store}, making it read-only for all the users including
10211 @code{root}. This prevents against accidental modification by software
10212 running as @code{root} or by system administrators.
10214 The daemon itself is still able to write to the store: it remounts it
10215 read-write in its own ``name space.''
10218 @defvr {Scheme Variable} %binary-format-file-system
10219 The @code{binfmt_misc} file system, which allows handling of arbitrary
10220 executable file types to be delegated to user space. This requires the
10221 @code{binfmt.ko} kernel module to be loaded.
10224 @defvr {Scheme Variable} %fuse-control-file-system
10225 The @code{fusectl} file system, which allows unprivileged users to mount
10226 and unmount user-space FUSE file systems. This requires the
10227 @code{fuse.ko} kernel module to be loaded.
10230 @node Mapped Devices
10231 @subsection Mapped Devices
10233 @cindex device mapping
10234 @cindex mapped devices
10235 The Linux kernel has a notion of @dfn{device mapping}: a block device,
10236 such as a hard disk partition, can be @dfn{mapped} into another device,
10237 usually in @code{/dev/mapper/},
10238 with additional processing over the data that flows through
10239 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
10240 concept of a ``mapped device'' and that of a file system: both boil down
10241 to @emph{translating} input/output operations made on a file to
10242 operations on its backing store. Thus, the Hurd implements mapped
10243 devices, like file systems, using the generic @dfn{translator} mechanism
10244 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
10245 typical example is encryption device mapping: all writes to the mapped
10246 device are encrypted, and all reads are deciphered, transparently.
10247 Guix extends this notion by considering any device or set of devices that
10248 are @dfn{transformed} in some way to create a new device; for instance,
10249 RAID devices are obtained by @dfn{assembling} several other devices, such
10250 as hard disks or partitions, into a new one that behaves as one partition.
10251 Other examples, not yet implemented, are LVM logical volumes.
10253 Mapped devices are declared using the @code{mapped-device} form,
10254 defined as follows; for examples, see below.
10256 @deftp {Data Type} mapped-device
10257 Objects of this type represent device mappings that will be made when
10258 the system boots up.
10262 This is either a string specifying the name of the block device to be mapped,
10263 such as @code{"/dev/sda3"}, or a list of such strings when several devices
10264 need to be assembled for creating a new one.
10267 This string specifies the name of the resulting mapped device. For
10268 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
10269 specifying @code{"my-partition"} leads to the creation of
10270 the @code{"/dev/mapper/my-partition"} device.
10271 For RAID devices of type @code{raid-device-mapping}, the full device name
10272 such as @code{"/dev/md0"} needs to be given.
10275 This must be a @code{mapped-device-kind} object, which specifies how
10276 @var{source} is mapped to @var{target}.
10280 @defvr {Scheme Variable} luks-device-mapping
10281 This defines LUKS block device encryption using the @command{cryptsetup}
10282 command from the package with the same name. It relies on the
10283 @code{dm-crypt} Linux kernel module.
10286 @defvr {Scheme Variable} raid-device-mapping
10287 This defines a RAID device, which is assembled using the @code{mdadm}
10288 command from the package with the same name. It requires a Linux kernel
10289 module for the appropriate RAID level to be loaded, such as @code{raid456}
10290 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
10293 @cindex disk encryption
10295 The following example specifies a mapping from @file{/dev/sda3} to
10296 @file{/dev/mapper/home} using LUKS---the
10297 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
10298 standard mechanism for disk encryption.
10299 The @file{/dev/mapper/home}
10300 device can then be used as the @code{device} of a @code{file-system}
10301 declaration (@pxref{File Systems}).
10305 (source "/dev/sda3")
10307 (type luks-device-mapping))
10310 Alternatively, to become independent of device numbering, one may obtain
10311 the LUKS UUID (@dfn{unique identifier}) of the source device by a
10315 cryptsetup luksUUID /dev/sda3
10318 and use it as follows:
10322 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
10324 (type luks-device-mapping))
10327 @cindex swap encryption
10328 It is also desirable to encrypt swap space, since swap space may contain
10329 sensitive data. One way to accomplish that is to use a swap file in a
10330 file system on a device mapped via LUKS encryption. In this way, the
10331 swap file is encrypted because the entire device is encrypted.
10332 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
10334 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
10335 may be declared as follows:
10339 (source (list "/dev/sda1" "/dev/sdb1"))
10340 (target "/dev/md0")
10341 (type raid-device-mapping))
10344 The @file{/dev/md0} device can then be used as the @code{device} of a
10345 @code{file-system} declaration (@pxref{File Systems}).
10346 Note that the RAID level need not be given; it is chosen during the
10347 initial creation and formatting of the RAID device and is determined
10348 automatically later.
10351 @node User Accounts
10352 @subsection User Accounts
10356 @cindex user accounts
10357 User accounts and groups are entirely managed through the
10358 @code{operating-system} declaration. They are specified with the
10359 @code{user-account} and @code{user-group} forms:
10365 (supplementary-groups '("wheel" ;allow use of sudo, etc.
10366 "audio" ;sound card
10367 "video" ;video devices such as webcams
10368 "cdrom")) ;the good ol' CD-ROM
10369 (comment "Bob's sister")
10370 (home-directory "/home/alice"))
10373 When booting or upon completion of @command{guix system reconfigure},
10374 the system ensures that only the user accounts and groups specified in
10375 the @code{operating-system} declaration exist, and with the specified
10376 properties. Thus, account or group creations or modifications made by
10377 directly invoking commands such as @command{useradd} are lost upon
10378 reconfiguration or reboot. This ensures that the system remains exactly
10381 @deftp {Data Type} user-account
10382 Objects of this type represent user accounts. The following members may
10387 The name of the user account.
10391 This is the name (a string) or identifier (a number) of the user group
10392 this account belongs to.
10394 @item @code{supplementary-groups} (default: @code{'()})
10395 Optionally, this can be defined as a list of group names that this
10396 account belongs to.
10398 @item @code{uid} (default: @code{#f})
10399 This is the user ID for this account (a number), or @code{#f}. In the
10400 latter case, a number is automatically chosen by the system when the
10401 account is created.
10403 @item @code{comment} (default: @code{""})
10404 A comment about the account, such as the account owner's full name.
10406 @item @code{home-directory}
10407 This is the name of the home directory for the account.
10409 @item @code{create-home-directory?} (default: @code{#t})
10410 Indicates whether the home directory of this account should be created
10411 if it does not exist yet.
10413 @item @code{shell} (default: Bash)
10414 This is a G-expression denoting the file name of a program to be used as
10415 the shell (@pxref{G-Expressions}).
10417 @item @code{system?} (default: @code{#f})
10418 This Boolean value indicates whether the account is a ``system''
10419 account. System accounts are sometimes treated specially; for instance,
10420 graphical login managers do not list them.
10422 @anchor{user-account-password}
10423 @item @code{password} (default: @code{#f})
10424 You would normally leave this field to @code{#f}, initialize user
10425 passwords as @code{root} with the @command{passwd} command, and then let
10426 users change it with @command{passwd}. Passwords set with
10427 @command{passwd} are of course preserved across reboot and
10430 If you @emph{do} want to have a preset password for an account, then
10431 this field must contain the encrypted password, as a string.
10432 @xref{crypt,,, libc, The GNU C Library Reference Manual}, for more information
10433 on password encryption, and @ref{Encryption,,, guile, GNU Guile Reference
10434 Manual}, for information on Guile's @code{crypt} procedure.
10440 User group declarations are even simpler:
10443 (user-group (name "students"))
10446 @deftp {Data Type} user-group
10447 This type is for, well, user groups. There are just a few fields:
10451 The name of the group.
10453 @item @code{id} (default: @code{#f})
10454 The group identifier (a number). If @code{#f}, a new number is
10455 automatically allocated when the group is created.
10457 @item @code{system?} (default: @code{#f})
10458 This Boolean value indicates whether the group is a ``system'' group.
10459 System groups have low numerical IDs.
10461 @item @code{password} (default: @code{#f})
10462 What, user groups can have a password? Well, apparently yes. Unless
10463 @code{#f}, this field specifies the password of the group.
10468 For convenience, a variable lists all the basic user groups one may
10471 @defvr {Scheme Variable} %base-groups
10472 This is the list of basic user groups that users and/or packages expect
10473 to be present on the system. This includes groups such as ``root'',
10474 ``wheel'', and ``users'', as well as groups used to control access to
10475 specific devices such as ``audio'', ``disk'', and ``cdrom''.
10478 @defvr {Scheme Variable} %base-user-accounts
10479 This is the list of basic system accounts that programs may expect to
10480 find on a GNU/Linux system, such as the ``nobody'' account.
10482 Note that the ``root'' account is not included here. It is a
10483 special-case and is automatically added whether or not it is specified.
10487 @subsection Locales
10490 A @dfn{locale} defines cultural conventions for a particular language
10491 and region of the world (@pxref{Locales,,, libc, The GNU C Library
10492 Reference Manual}). Each locale has a name that typically has the form
10493 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
10494 @code{fr_LU.utf8} designates the locale for the French language, with
10495 cultural conventions from Luxembourg, and using the UTF-8 encoding.
10497 @cindex locale definition
10498 Usually, you will want to specify the default locale for the machine
10499 using the @code{locale} field of the @code{operating-system} declaration
10500 (@pxref{operating-system Reference, @code{locale}}).
10502 The selected locale is automatically added to the @dfn{locale
10503 definitions} known to the system if needed, with its codeset inferred
10504 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
10505 @code{UTF-8} codeset. Additional locale definitions can be specified in
10506 the @code{locale-definitions} slot of @code{operating-system}---this is
10507 useful, for instance, if the codeset could not be inferred from the
10508 locale name. The default set of locale definitions includes some widely
10509 used locales, but not all the available locales, in order to save space.
10511 For instance, to add the North Frisian locale for Germany, the value of
10515 (cons (locale-definition
10516 (name "fy_DE.utf8") (source "fy_DE"))
10517 %default-locale-definitions)
10520 Likewise, to save space, one might want @code{locale-definitions} to
10521 list only the locales that are actually used, as in:
10524 (list (locale-definition
10525 (name "ja_JP.eucjp") (source "ja_JP")
10526 (charset "EUC-JP")))
10530 The compiled locale definitions are available at
10531 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
10532 version, which is the default location where the GNU@tie{}libc provided
10533 by Guix looks for locale data. This can be overridden using the
10534 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
10535 @code{LOCPATH} and locale packages}).
10537 The @code{locale-definition} form is provided by the @code{(gnu system
10538 locale)} module. Details are given below.
10540 @deftp {Data Type} locale-definition
10541 This is the data type of a locale definition.
10546 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
10547 Reference Manual}, for more information on locale names.
10549 @item @code{source}
10550 The name of the source for that locale. This is typically the
10551 @code{@var{language}_@var{territory}} part of the locale name.
10553 @item @code{charset} (default: @code{"UTF-8"})
10554 The ``character set'' or ``code set'' for that locale,
10555 @uref{http://www.iana.org/assignments/character-sets, as defined by
10561 @defvr {Scheme Variable} %default-locale-definitions
10562 A list of commonly used UTF-8 locales, used as the default
10563 value of the @code{locale-definitions} field of @code{operating-system}
10566 @cindex locale name
10567 @cindex normalized codeset in locale names
10568 These locale definitions use the @dfn{normalized codeset} for the part
10569 that follows the dot in the name (@pxref{Using gettextized software,
10570 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
10571 instance it has @code{uk_UA.utf8} but @emph{not}, say,
10572 @code{uk_UA.UTF-8}.
10575 @subsubsection Locale Data Compatibility Considerations
10577 @cindex incompatibility, of locale data
10578 @code{operating-system} declarations provide a @code{locale-libcs} field
10579 to specify the GNU@tie{}libc packages that are used to compile locale
10580 declarations (@pxref{operating-system Reference}). ``Why would I
10581 care?'', you may ask. Well, it turns out that the binary format of
10582 locale data is occasionally incompatible from one libc version to
10585 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
10586 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
10587 For instance, a program linked against libc version 2.21 is unable to
10588 read locale data produced with libc 2.22; worse, that program
10589 @emph{aborts} instead of simply ignoring the incompatible locale
10590 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
10591 the incompatible locale data, which is already an improvement.}.
10592 Similarly, a program linked against libc 2.22 can read most, but not
10593 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
10594 data is incompatible); thus calls to @code{setlocale} may fail, but
10595 programs will not abort.
10597 The ``problem'' in GuixSD is that users have a lot of freedom: They can
10598 choose whether and when to upgrade software in their profiles, and might
10599 be using a libc version different from the one the system administrator
10600 used to build the system-wide locale data.
10602 Fortunately, unprivileged users can also install their own locale data
10603 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
10604 @code{GUIX_LOCPATH} and locale packages}).
10606 Still, it is best if the system-wide locale data at
10607 @file{/run/current-system/locale} is built for all the libc versions
10608 actually in use on the system, so that all the programs can access
10609 it---this is especially crucial on a multi-user system. To do that, the
10610 administrator can specify several libc packages in the
10611 @code{locale-libcs} field of @code{operating-system}:
10614 (use-package-modules base)
10618 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
10621 This example would lead to a system containing locale definitions for
10622 both libc 2.21 and the current version of libc in
10623 @file{/run/current-system/locale}.
10627 @subsection Services
10629 @cindex system services
10630 An important part of preparing an @code{operating-system} declaration is
10631 listing @dfn{system services} and their configuration (@pxref{Using the
10632 Configuration System}). System services are typically daemons launched
10633 when the system boots, or other actions needed at that time---e.g.,
10634 configuring network access.
10636 GuixSD has a broad definition of ``service'' (@pxref{Service
10637 Composition}), but many services are managed by the GNU@tie{}Shepherd
10638 (@pxref{Shepherd Services}). On a running system, the @command{herd}
10639 command allows you to list the available services, show their status,
10640 start and stop them, or do other specific operations (@pxref{Jump
10641 Start,,, shepherd, The GNU Shepherd Manual}). For example:
10647 The above command, run as @code{root}, lists the currently defined
10648 services. The @command{herd doc} command shows a synopsis of the given
10649 service and its associated actions:
10653 Run libc's name service cache daemon (nscd).
10655 # herd doc nscd action invalidate
10656 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
10659 The @command{start}, @command{stop}, and @command{restart} sub-commands
10660 have the effect you would expect. For instance, the commands below stop
10661 the nscd service and restart the Xorg display server:
10665 Service nscd has been stopped.
10666 # herd restart xorg-server
10667 Service xorg-server has been stopped.
10668 Service xorg-server has been started.
10671 The following sections document the available services, starting with
10672 the core services, that may be used in an @code{operating-system}
10676 * Base Services:: Essential system services.
10677 * Scheduled Job Execution:: The mcron service.
10678 * Log Rotation:: The rottlog service.
10679 * Networking Services:: Network setup, SSH daemon, etc.
10680 * X Window:: Graphical display.
10681 * Printing Services:: Local and remote printer support.
10682 * Desktop Services:: D-Bus and desktop services.
10683 * Sound Services:: ALSA and Pulseaudio services.
10684 * Database Services:: SQL databases, key-value stores, etc.
10685 * Mail Services:: IMAP, POP3, SMTP, and all that.
10686 * Messaging Services:: Messaging services.
10687 * Telephony Services:: Telephony services.
10688 * Monitoring Services:: Monitoring services.
10689 * Kerberos Services:: Kerberos services.
10690 * Web Services:: Web servers.
10691 * Certificate Services:: TLS certificates via Let's Encrypt.
10692 * DNS Services:: DNS daemons.
10693 * VPN Services:: VPN daemons.
10694 * Network File System:: NFS related services.
10695 * Continuous Integration:: The Cuirass service.
10696 * Power Management Services:: Extending battery life.
10697 * Audio Services:: The MPD.
10698 * Virtualization Services:: Virtualization services.
10699 * Version Control Services:: Providing remote access to Git repositories.
10700 * Game Services:: Game servers.
10701 * Miscellaneous Services:: Other services.
10704 @node Base Services
10705 @subsubsection Base Services
10707 The @code{(gnu services base)} module provides definitions for the basic
10708 services that one expects from the system. The services exported by
10709 this module are listed below.
10711 @defvr {Scheme Variable} %base-services
10712 This variable contains a list of basic services (@pxref{Service Types
10713 and Services}, for more information on service objects) one would
10714 expect from the system: a login service (mingetty) on each tty, syslogd,
10715 the libc name service cache daemon (nscd), the udev device manager, and
10718 This is the default value of the @code{services} field of
10719 @code{operating-system} declarations. Usually, when customizing a
10720 system, you will want to append services to @var{%base-services}, like
10724 (cons* (avahi-service) (lsh-service) %base-services)
10728 @defvr {Scheme Variable} special-files-service-type
10729 This is the service that sets up ``special files'' such as
10730 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
10732 The value associated with @code{special-files-service-type} services
10733 must be a list of tuples where the first element is the ``special file''
10734 and the second element is its target. By default it is:
10736 @cindex @file{/bin/sh}
10737 @cindex @file{sh}, in @file{/bin}
10739 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
10742 @cindex @file{/usr/bin/env}
10743 @cindex @file{env}, in @file{/usr/bin}
10744 If you want to add, say, @code{/usr/bin/env} to your system, you can
10748 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
10749 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
10752 Since this is part of @code{%base-services}, you can use
10753 @code{modify-services} to customize the set of special files
10754 (@pxref{Service Reference, @code{modify-services}}). But the simple way
10755 to add a special file is @i{via} the @code{extra-special-file} procedure
10759 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
10760 Use @var{target} as the ``special file'' @var{file}.
10762 For example, adding the following lines to the @code{services} field of
10763 your operating system declaration leads to a @file{/usr/bin/env}
10767 (extra-special-file "/usr/bin/env"
10768 (file-append coreutils "/bin/env"))
10772 @deffn {Scheme Procedure} host-name-service @var{name}
10773 Return a service that sets the host name to @var{name}.
10776 @deffn {Scheme Procedure} login-service @var{config}
10777 Return a service to run login according to @var{config}, a
10778 @code{<login-configuration>} object, which specifies the message of the day,
10779 among other things.
10782 @deftp {Data Type} login-configuration
10783 This is the data type representing the configuration of login.
10788 @cindex message of the day
10789 A file-like object containing the ``message of the day''.
10791 @item @code{allow-empty-passwords?} (default: @code{#t})
10792 Allow empty passwords by default so that first-time users can log in when
10793 the 'root' account has just been created.
10798 @deffn {Scheme Procedure} mingetty-service @var{config}
10799 Return a service to run mingetty according to @var{config}, a
10800 @code{<mingetty-configuration>} object, which specifies the tty to run, among
10804 @deftp {Data Type} mingetty-configuration
10805 This is the data type representing the configuration of Mingetty, which
10806 provides the default implementation of virtual console log-in.
10811 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
10813 @item @code{auto-login} (default: @code{#f})
10814 When true, this field must be a string denoting the user name under
10815 which the system automatically logs in. When it is @code{#f}, a
10816 user name and password must be entered to log in.
10818 @item @code{login-program} (default: @code{#f})
10819 This must be either @code{#f}, in which case the default log-in program
10820 is used (@command{login} from the Shadow tool suite), or a gexp denoting
10821 the name of the log-in program.
10823 @item @code{login-pause?} (default: @code{#f})
10824 When set to @code{#t} in conjunction with @var{auto-login}, the user
10825 will have to press a key before the log-in shell is launched.
10827 @item @code{mingetty} (default: @var{mingetty})
10828 The Mingetty package to use.
10833 @deffn {Scheme Procedure} agetty-service @var{config}
10834 Return a service to run agetty according to @var{config}, an
10835 @code{<agetty-configuration>} object, which specifies the tty to run,
10836 among other things.
10839 @deftp {Data Type} agetty-configuration
10840 This is the data type representing the configuration of agetty, which
10841 implements virtual and serial console log-in. See the @code{agetty(8)}
10842 man page for more information.
10847 The name of the console this agetty runs on, as a string---e.g.,
10848 @code{"ttyS0"}. This argument is optional, it will default to
10849 a reasonable default serial port used by the kernel Linux.
10851 For this, if there is a value for an option @code{agetty.tty} in the kernel
10852 command line, agetty will extract the device name of the serial port
10853 from it and use that.
10855 If not and if there is a value for an option @code{console} with a tty in
10856 the Linux command line, agetty will extract the device name of the
10857 serial port from it and use that.
10859 In both cases, agetty will leave the other serial device settings
10860 (baud rate etc.) alone---in the hope that Linux pinned them to the
10863 @item @code{baud-rate} (default: @code{#f})
10864 A string containing a comma-separated list of one or more baud rates, in
10867 @item @code{term} (default: @code{#f})
10868 A string containing the value used for the @code{TERM} environment
10871 @item @code{eight-bits?} (default: @code{#f})
10872 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
10875 @item @code{auto-login} (default: @code{#f})
10876 When passed a login name, as a string, the specified user will be logged
10877 in automatically without prompting for their login name or password.
10879 @item @code{no-reset?} (default: @code{#f})
10880 When @code{#t}, don't reset terminal cflags (control modes).
10882 @item @code{host} (default: @code{#f})
10883 This accepts a string containing the "login_host", which will be written
10884 into the @file{/var/run/utmpx} file.
10886 @item @code{remote?} (default: @code{#f})
10887 When set to @code{#t} in conjunction with @var{host}, this will add an
10888 @code{-r} fakehost option to the command line of the login program
10889 specified in @var{login-program}.
10891 @item @code{flow-control?} (default: @code{#f})
10892 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
10894 @item @code{no-issue?} (default: @code{#f})
10895 When set to @code{#t}, the contents of the @file{/etc/issue} file will
10896 not be displayed before presenting the login prompt.
10898 @item @code{init-string} (default: @code{#f})
10899 This accepts a string that will be sent to the tty or modem before
10900 sending anything else. It can be used to initialize a modem.
10902 @item @code{no-clear?} (default: @code{#f})
10903 When set to @code{#t}, agetty will not clear the screen before showing
10906 @item @code{login-program} (default: (file-append shadow "/bin/login"))
10907 This must be either a gexp denoting the name of a log-in program, or
10908 unset, in which case the default value is the @command{login} from the
10911 @item @code{local-line} (default: @code{#f})
10912 Control the CLOCAL line flag. This accepts one of three symbols as
10913 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
10914 the default value chosen by agetty is @code{'auto}.
10916 @item @code{extract-baud?} (default: @code{#f})
10917 When set to @code{#t}, instruct agetty to try to extract the baud rate
10918 from the status messages produced by certain types of modems.
10920 @item @code{skip-login?} (default: @code{#f})
10921 When set to @code{#t}, do not prompt the user for a login name. This
10922 can be used with @var{login-program} field to use non-standard login
10925 @item @code{no-newline?} (default: @code{#f})
10926 When set to @code{#t}, do not print a newline before printing the
10927 @file{/etc/issue} file.
10929 @c Is this dangerous only when used with login-program, or always?
10930 @item @code{login-options} (default: @code{#f})
10931 This option accepts a string containing options that are passed to the
10932 login program. When used with the @var{login-program}, be aware that a
10933 malicious user could try to enter a login name containing embedded
10934 options that could be parsed by the login program.
10936 @item @code{login-pause} (default: @code{#f})
10937 When set to @code{#t}, wait for any key before showing the login prompt.
10938 This can be used in conjunction with @var{auto-login} to save memory by
10939 lazily spawning shells.
10941 @item @code{chroot} (default: @code{#f})
10942 Change root to the specified directory. This option accepts a directory
10945 @item @code{hangup?} (default: @code{#f})
10946 Use the Linux system call @code{vhangup} to do a virtual hangup of the
10947 specified terminal.
10949 @item @code{keep-baud?} (default: @code{#f})
10950 When set to @code{#t}, try to keep the existing baud rate. The baud
10951 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
10954 @item @code{timeout} (default: @code{#f})
10955 When set to an integer value, terminate if no user name could be read
10956 within @var{timeout} seconds.
10958 @item @code{detect-case?} (default: @code{#f})
10959 When set to @code{#t}, turn on support for detecting an uppercase-only
10960 terminal. This setting will detect a login name containing only
10961 uppercase letters as indicating an uppercase-only terminal and turn on
10962 some upper-to-lower case conversions. Note that this will not support
10963 Unicode characters.
10965 @item @code{wait-cr?} (default: @code{#f})
10966 When set to @code{#t}, wait for the user or modem to send a
10967 carriage-return or linefeed character before displaying
10968 @file{/etc/issue} or login prompt. This is typically used with the
10969 @var{init-string} option.
10971 @item @code{no-hints?} (default: @code{#f})
10972 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
10975 @item @code{no-hostname?} (default: @code{#f})
10976 By default, the hostname is printed. When this option is set to
10977 @code{#t}, no hostname will be shown at all.
10979 @item @code{long-hostname?} (default: @code{#f})
10980 By default, the hostname is only printed until the first dot. When this
10981 option is set to @code{#t}, the fully qualified hostname by
10982 @code{gethostname} or @code{getaddrinfo} is shown.
10984 @item @code{erase-characters} (default: @code{#f})
10985 This option accepts a string of additional characters that should be
10986 interpreted as backspace when the user types their login name.
10988 @item @code{kill-characters} (default: @code{#f})
10989 This option accepts a string that should be interpreted to mean "ignore
10990 all previous characters" (also called a "kill" character) when the types
10993 @item @code{chdir} (default: @code{#f})
10994 This option accepts, as a string, a directory path that will be changed
10997 @item @code{delay} (default: @code{#f})
10998 This options accepts, as an integer, the number of seconds to sleep
10999 before opening the tty and displaying the login prompt.
11001 @item @code{nice} (default: @code{#f})
11002 This option accepts, as an integer, the nice value with which to run the
11003 @command{login} program.
11005 @item @code{extra-options} (default: @code{'()})
11006 This option provides an "escape hatch" for the user to provide arbitrary
11007 command-line arguments to @command{agetty} as a list of strings.
11012 @deffn {Scheme Procedure} kmscon-service-type @var{config}
11013 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
11014 according to @var{config}, a @code{<kmscon-configuration>} object, which
11015 specifies the tty to run, among other things.
11018 @deftp {Data Type} kmscon-configuration
11019 This is the data type representing the configuration of Kmscon, which
11020 implements virtual console log-in.
11024 @item @code{virtual-terminal}
11025 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
11027 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
11028 A gexp denoting the name of the log-in program. The default log-in program is
11029 @command{login} from the Shadow tool suite.
11031 @item @code{login-arguments} (default: @code{'("-p")})
11032 A list of arguments to pass to @command{login}.
11034 @item @code{auto-login} (default: @code{#f})
11035 When passed a login name, as a string, the specified user will be logged
11036 in automatically without prompting for their login name or password.
11038 @item @code{hardware-acceleration?} (default: #f)
11039 Whether to use hardware acceleration.
11041 @item @code{kmscon} (default: @var{kmscon})
11042 The Kmscon package to use.
11047 @cindex name service cache daemon
11049 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
11050 [#:name-services '()]
11051 Return a service that runs the libc name service cache daemon (nscd) with the
11052 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
11053 Service Switch}, for an example.
11055 For convenience, the Shepherd service for nscd provides the following actions:
11059 @cindex cache invalidation, nscd
11060 @cindex nscd, cache invalidation
11061 This invalidate the given cache. For instance, running:
11064 herd invalidate nscd hosts
11068 invalidates the host name lookup cache of nscd.
11071 Running @command{herd statistics nscd} displays information about nscd usage
11077 @defvr {Scheme Variable} %nscd-default-configuration
11078 This is the default @code{<nscd-configuration>} value (see below) used
11079 by @code{nscd-service}. It uses the caches defined by
11080 @var{%nscd-default-caches}; see below.
11083 @deftp {Data Type} nscd-configuration
11084 This is the data type representing the name service cache daemon (nscd)
11089 @item @code{name-services} (default: @code{'()})
11090 List of packages denoting @dfn{name services} that must be visible to
11091 the nscd---e.g., @code{(list @var{nss-mdns})}.
11093 @item @code{glibc} (default: @var{glibc})
11094 Package object denoting the GNU C Library providing the @command{nscd}
11097 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
11098 Name of the nscd log file. This is where debugging output goes when
11099 @code{debug-level} is strictly positive.
11101 @item @code{debug-level} (default: @code{0})
11102 Integer denoting the debugging levels. Higher numbers mean that more
11103 debugging output is logged.
11105 @item @code{caches} (default: @var{%nscd-default-caches})
11106 List of @code{<nscd-cache>} objects denoting things to be cached; see
11112 @deftp {Data Type} nscd-cache
11113 Data type representing a cache database of nscd and its parameters.
11117 @item @code{database}
11118 This is a symbol representing the name of the database to be cached.
11119 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
11120 @code{services}, which designate the corresponding NSS database
11121 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
11123 @item @code{positive-time-to-live}
11124 @itemx @code{negative-time-to-live} (default: @code{20})
11125 A number representing the number of seconds during which a positive or
11126 negative lookup result remains in cache.
11128 @item @code{check-files?} (default: @code{#t})
11129 Whether to check for updates of the files corresponding to
11132 For instance, when @var{database} is @code{hosts}, setting this flag
11133 instructs nscd to check for updates in @file{/etc/hosts} and to take
11136 @item @code{persistent?} (default: @code{#t})
11137 Whether the cache should be stored persistently on disk.
11139 @item @code{shared?} (default: @code{#t})
11140 Whether the cache should be shared among users.
11142 @item @code{max-database-size} (default: 32@tie{}MiB)
11143 Maximum size in bytes of the database cache.
11145 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
11146 @c settings, so leave them out.
11151 @defvr {Scheme Variable} %nscd-default-caches
11152 List of @code{<nscd-cache>} objects used by default by
11153 @code{nscd-configuration} (see above).
11155 It enables persistent and aggressive caching of service and host name
11156 lookups. The latter provides better host name lookup performance,
11157 resilience in the face of unreliable name servers, and also better
11158 privacy---often the result of host name lookups is in local cache, so
11159 external name servers do not even need to be queried.
11162 @anchor{syslog-configuration-type}
11165 @deftp {Data Type} syslog-configuration
11166 This data type represents the configuration of the syslog daemon.
11169 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
11170 The syslog daemon to use.
11172 @item @code{config-file} (default: @code{%default-syslog.conf})
11173 The syslog configuration file to use.
11178 @anchor{syslog-service}
11180 @deffn {Scheme Procedure} syslog-service @var{config}
11181 Return a service that runs a syslog daemon according to @var{config}.
11183 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
11184 information on the configuration file syntax.
11187 @defvr {Scheme Variable} guix-service-type
11188 This is the type of the service that runs the build daemon,
11189 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
11190 @code{guix-configuration} record as described below.
11193 @anchor{guix-configuration-type}
11194 @deftp {Data Type} guix-configuration
11195 This data type represents the configuration of the Guix build daemon.
11196 @xref{Invoking guix-daemon}, for more information.
11199 @item @code{guix} (default: @var{guix})
11200 The Guix package to use.
11202 @item @code{build-group} (default: @code{"guixbuild"})
11203 Name of the group for build user accounts.
11205 @item @code{build-accounts} (default: @code{10})
11206 Number of build user accounts to create.
11208 @item @code{authorize-key?} (default: @code{#t})
11209 @cindex substitutes, authorization thereof
11210 Whether to authorize the substitute keys listed in
11211 @code{authorized-keys}---by default that of @code{hydra.gnu.org}
11212 (@pxref{Substitutes}).
11214 @vindex %default-authorized-guix-keys
11215 @item @code{authorized-keys} (default: @var{%default-authorized-guix-keys})
11216 The list of authorized key files for archive imports, as a list of
11217 string-valued gexps (@pxref{Invoking guix archive}). By default, it
11218 contains that of @code{hydra.gnu.org} (@pxref{Substitutes}).
11220 @item @code{use-substitutes?} (default: @code{#t})
11221 Whether to use substitutes.
11223 @item @code{substitute-urls} (default: @var{%default-substitute-urls})
11224 The list of URLs where to look for substitutes by default.
11226 @item @code{max-silent-time} (default: @code{0})
11227 @itemx @code{timeout} (default: @code{0})
11228 The number of seconds of silence and the number of seconds of activity,
11229 respectively, after which a build process times out. A value of zero
11230 disables the timeout.
11232 @item @code{log-compression} (default: @code{'bzip2})
11233 The type of compression used for build logs---one of @code{gzip},
11234 @code{bzip2}, or @code{none}.
11236 @item @code{extra-options} (default: @code{'()})
11237 List of extra command-line options for @command{guix-daemon}.
11239 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
11240 File where @command{guix-daemon}'s standard output and standard error
11243 @item @code{http-proxy} (default: @code{#f})
11244 The HTTP proxy used for downloading fixed-output derivations and
11247 @item @code{tmpdir} (default: @code{#f})
11248 A directory path where the @command{guix-daemon} will perform builds.
11253 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
11254 Run @var{udev}, which populates the @file{/dev} directory dynamically.
11255 udev rules can be provided as a list of files through the @var{rules}
11256 variable. The procedures @var{udev-rule} and @var{file->udev-rule} from
11257 @code{(gnu services base)} simplify the creation of such rule files.
11259 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
11260 Return a udev-rule file named @var{file-name} containing the rules
11261 defined by the @var{contents} literal.
11263 In the following example, a rule for a USB device is defined to be
11264 stored in the file @file{90-usb-thing.rules}. The rule runs a script
11265 upon detecting a USB device with a given product identifier.
11268 (define %example-udev-rule
11270 "90-usb-thing.rules"
11271 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
11272 "ATTR@{product@}==\"Example\", "
11273 "RUN+=\"/path/to/script\"")))
11277 Here we show how the default @var{udev-service} can be extended with it.
11283 (modify-services %desktop-services
11284 (udev-service-type config =>
11285 (udev-configuration (inherit config)
11286 (rules (append (udev-configuration-rules config)
11287 (list %example-udev-rule))))))))
11290 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
11291 Return a udev file named @var{file-name} containing the rules defined
11292 within @var{file}, a file-like object.
11294 The following example showcases how we can use an existing rule file.
11297 (use-modules (guix download) ;for url-fetch
11298 (guix packages) ;for origin
11301 (define %android-udev-rules
11303 "51-android-udev.rules"
11304 (let ((version "20170910"))
11307 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
11308 "android-udev-rules/" version "/51-android.rules"))
11310 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
11314 Additionally, Guix package definitions can be included in @var{rules} in
11315 order to extend the udev rules with the definitions found under their
11316 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
11317 @var{file->udev-rule} example, we could have used the
11318 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
11319 packages android)} module.
11321 The following example shows how to use the @var{android-udev-rules}
11322 package so that the Android tool @command{adb} can detect devices
11323 without root privileges. It also details how to create the
11324 @code{adbusers} group, which is required for the proper functioning of
11325 the rules defined within the @var{android-udev-rules} package. To
11326 create such a group, we must define it both as part of the
11327 @var{supplementary-groups} of our @var{user-account} declaration, as
11328 well as in the @var{groups} field of the @var{operating-system} record.
11331 (use-modules (gnu packages android) ;for android-udev-rules
11332 (gnu system shadow) ;for user-group
11337 (users (cons (user-acount
11339 (supplementary-groups
11340 '("adbusers" ;for adb
11341 "wheel" "netdev" "audio" "video"))
11344 (groups (cons (user-group (system? #t) (name "adbusers"))
11350 (modify-services %desktop-services
11351 (udev-service-type config =>
11352 (udev-configuration (inherit config)
11353 (rules (cons* android-udev-rules
11354 (udev-configuration-rules config))))))))
11358 @defvr {Scheme Variable} urandom-seed-service-type
11359 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
11360 when rebooting. It also tries to seed @file{/dev/urandom} from
11361 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
11365 @defvr {Scheme Variable} %random-seed-file
11366 This is the name of the file where some random bytes are saved by
11367 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
11368 It defaults to @file{/var/lib/random-seed}.
11373 @deffn {Scheme Procedure} console-keymap-service @var{files} ...
11374 @cindex keyboard layout
11375 Return a service to load console keymaps from @var{files} using
11376 @command{loadkeys} command. Most likely, you want to load some default
11377 keymap, which can be done like this:
11380 (console-keymap-service "dvorak")
11383 Or, for example, for a Swedish keyboard, you may need to combine
11384 the following keymaps:
11386 (console-keymap-service "se-lat6" "se-fi-lat6")
11389 Also you can specify a full file name (or file names) of your keymap(s).
11390 See @code{man loadkeys} for details.
11396 @defvr {Scheme Variable} gpm-service-type
11397 This is the type of the service that runs GPM, the @dfn{general-purpose
11398 mouse daemon}, which provides mouse support to the Linux console. GPM
11399 allows users to use the mouse in the console, notably to select, copy,
11402 The value for services of this type must be a @code{gpm-configuration}
11403 (see below). This service is not part of @var{%base-services}.
11406 @deftp {Data Type} gpm-configuration
11407 Data type representing the configuration of GPM.
11410 @item @code{options} (default: @code{%default-gpm-options})
11411 Command-line options passed to @command{gpm}. The default set of
11412 options instruct @command{gpm} to listen to mouse events on
11413 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
11416 @item @code{gpm} (default: @code{gpm})
11417 The GPM package to use.
11422 @anchor{guix-publish-service-type}
11423 @deffn {Scheme Variable} guix-publish-service-type
11424 This is the service type for @command{guix publish} (@pxref{Invoking
11425 guix publish}). Its value must be a @code{guix-configuration}
11426 object, as described below.
11428 This assumes that @file{/etc/guix} already contains a signing key pair as
11429 created by @command{guix archive --generate-key} (@pxref{Invoking guix
11430 archive}). If that is not the case, the service will fail to start.
11433 @deftp {Data Type} guix-publish-configuration
11434 Data type representing the configuration of the @code{guix publish}
11438 @item @code{guix} (default: @code{guix})
11439 The Guix package to use.
11441 @item @code{port} (default: @code{80})
11442 The TCP port to listen for connections.
11444 @item @code{host} (default: @code{"localhost"})
11445 The host (and thus, network interface) to listen to. Use
11446 @code{"0.0.0.0"} to listen on all the network interfaces.
11448 @item @code{compression-level} (default: @code{3})
11449 The gzip compression level at which substitutes are compressed. Use
11450 @code{0} to disable compression altogether, and @code{9} to get the best
11451 compression ratio at the expense of increased CPU usage.
11453 @item @code{nar-path} (default: @code{"nar"})
11454 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
11455 publish, @code{--nar-path}}, for details.
11457 @item @code{cache} (default: @code{#f})
11458 When it is @code{#f}, disable caching and instead generate archives on
11459 demand. Otherwise, this should be the name of a directory---e.g.,
11460 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
11461 archives and meta-data ready to be sent. @xref{Invoking guix publish,
11462 @option{--cache}}, for more information on the tradeoffs involved.
11464 @item @code{workers} (default: @code{#f})
11465 When it is an integer, this is the number of worker threads used for
11466 caching; when @code{#f}, the number of processors is used.
11467 @xref{Invoking guix publish, @option{--workers}}, for more information.
11469 @item @code{ttl} (default: @code{#f})
11470 When it is an integer, this denotes the @dfn{time-to-live} in seconds
11471 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
11472 for more information.
11476 @anchor{rngd-service}
11477 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
11478 [#:device "/dev/hwrng"]
11479 Return a service that runs the @command{rngd} program from @var{rng-tools}
11480 to add @var{device} to the kernel's entropy pool. The service will fail if
11481 @var{device} does not exist.
11484 @anchor{pam-limits-service}
11485 @cindex session limits
11490 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
11492 Return a service that installs a configuration file for the
11493 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
11494 @code{pam_limits} module}. The procedure optionally takes a list of
11495 @code{pam-limits-entry} values, which can be used to specify
11496 @code{ulimit} limits and nice priority limits to user sessions.
11498 The following limits definition sets two hard and soft limits for all
11499 login sessions of users in the @code{realtime} group:
11502 (pam-limits-service
11504 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
11505 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
11508 The first entry increases the maximum realtime priority for
11509 non-privileged processes; the second entry lifts any restriction of the
11510 maximum address space that can be locked in memory. These settings are
11511 commonly used for real-time audio systems.
11514 @node Scheduled Job Execution
11515 @subsubsection Scheduled Job Execution
11519 @cindex scheduling jobs
11520 The @code{(gnu services mcron)} module provides an interface to
11521 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
11522 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
11523 Unix @command{cron} daemon; the main difference is that it is
11524 implemented in Guile Scheme, which provides a lot of flexibility when
11525 specifying the scheduling of jobs and their actions.
11527 The example below defines an operating system that runs the
11528 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
11529 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
11530 well as the @command{mkid} command on behalf of an unprivileged user
11531 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
11532 gexps to introduce job definitions that are passed to mcron
11533 (@pxref{G-Expressions}).
11536 (use-modules (guix) (gnu) (gnu services mcron))
11537 (use-package-modules base idutils)
11539 (define updatedb-job
11540 ;; Run 'updatedb' at 3AM every day. Here we write the
11541 ;; job's action as a Scheme procedure.
11542 #~(job '(next-hour '(3))
11544 (execl (string-append #$findutils "/bin/updatedb")
11546 "--prunepaths=/tmp /var/tmp /gnu/store"))))
11548 (define garbage-collector-job
11549 ;; Collect garbage 5 minutes after midnight every day.
11550 ;; The job's action is a shell command.
11551 #~(job "5 0 * * *" ;Vixie cron syntax
11554 (define idutils-job
11555 ;; Update the index database as user "charlie" at 12:15PM
11556 ;; and 19:15PM. This runs from the user's home directory.
11557 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
11558 (string-append #$idutils "/bin/mkid src")
11563 (services (cons (mcron-service (list garbage-collector-job
11569 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
11570 for more information on mcron job specifications. Below is the
11571 reference of the mcron service.
11573 On a running system, you can use the @code{schedule} action of the service to
11574 visualize the mcron jobs that will be executed next:
11577 # herd schedule mcron
11581 The example above lists the next five tasks that will be executed, but you can
11582 also specify the number of tasks to display:
11585 # herd schedule mcron 10
11588 @deffn {Scheme Procedure} mcron-service @var{jobs} [#:mcron @var{mcron}]
11589 Return an mcron service running @var{mcron} that schedules @var{jobs}, a
11590 list of gexps denoting mcron job specifications.
11592 This is a shorthand for:
11594 (service mcron-service-type
11595 (mcron-configuration (mcron mcron) (jobs jobs)))
11599 @defvr {Scheme Variable} mcron-service-type
11600 This is the type of the @code{mcron} service, whose value is an
11601 @code{mcron-configuration} object.
11603 This service type can be the target of a service extension that provides
11604 it additional job specifications (@pxref{Service Composition}). In
11605 other words, it is possible to define services that provide additional
11609 @deftp {Data Type} mcron-configuration
11610 Data type representing the configuration of mcron.
11613 @item @code{mcron} (default: @var{mcron})
11614 The mcron package to use.
11617 This is a list of gexps (@pxref{G-Expressions}), where each gexp
11618 corresponds to an mcron job specification (@pxref{Syntax, mcron job
11619 specifications,, mcron, GNU@tie{}mcron}).
11625 @subsubsection Log Rotation
11628 @cindex log rotation
11630 Log files such as those found in @file{/var/log} tend to grow endlessly,
11631 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
11632 their contents in separate files, possibly compressed. The @code{(gnu
11633 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
11634 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
11636 The example below defines an operating system that provides log rotation
11637 with the default settings, for commonly encountered log files.
11640 (use-modules (guix) (gnu))
11641 (use-service-modules admin mcron)
11642 (use-package-modules base idutils)
11646 (services (cons (service rottlog-service-type)
11650 @defvr {Scheme Variable} rottlog-service-type
11651 This is the type of the Rottlog service, whose value is a
11652 @code{rottlog-configuration} object.
11654 Other services can extend this one with new @code{log-rotation} objects
11655 (see below), thereby augmenting the set of files to be rotated.
11657 This service type can define mcron jobs (@pxref{Scheduled Job
11658 Execution}) to run the rottlog service.
11661 @deftp {Data Type} rottlog-configuration
11662 Data type representing the configuration of rottlog.
11665 @item @code{rottlog} (default: @code{rottlog})
11666 The Rottlog package to use.
11668 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
11669 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
11670 rottlog, GNU Rot[t]log Manual}).
11672 @item @code{rotations} (default: @code{%default-rotations})
11673 A list of @code{log-rotation} objects as defined below.
11676 This is a list of gexps where each gexp corresponds to an mcron job
11677 specification (@pxref{Scheduled Job Execution}).
11681 @deftp {Data Type} log-rotation
11682 Data type representing the rotation of a group of log files.
11684 Taking an example from the Rottlog manual (@pxref{Period Related File
11685 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
11691 (files '("/var/log/apache/*"))
11692 (options '("storedir apache-archives"
11698 The list of fields is as follows:
11701 @item @code{frequency} (default: @code{'weekly})
11702 The log rotation frequency, a symbol.
11705 The list of files or file glob patterns to rotate.
11707 @item @code{options} (default: @code{'()})
11708 The list of rottlog options for this rotation (@pxref{Configuration
11709 parameters,,, rottlog, GNU Rot[t]lg Manual}).
11711 @item @code{post-rotate} (default: @code{#f})
11712 Either @code{#f} or a gexp to execute once the rotation has completed.
11716 @defvr {Scheme Variable} %default-rotations
11717 Specifies weekly rotation of @var{%rotated-files} and
11718 a couple of other files.
11721 @defvr {Scheme Variable} %rotated-files
11722 The list of syslog-controlled files to be rotated. By default it is:
11723 @code{'("/var/log/messages" "/var/log/secure")}.
11726 @node Networking Services
11727 @subsubsection Networking Services
11729 The @code{(gnu services networking)} module provides services to configure
11730 the network interface.
11732 @cindex DHCP, networking service
11733 @defvr {Scheme Variable} dhcp-client-service-type
11734 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
11735 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
11736 is the DHCP client package to use, @code{isc-dhcp} by default.
11739 @deffn {Scheme Procedure} dhcpd-service-type
11740 This type defines a service that runs a DHCP daemon. To create a
11741 service of this type, you must supply a @code{<dhcpd-configuration>}.
11745 (service dhcpd-service-type
11746 (dhcpd-configuration
11747 (config-file (local-file "my-dhcpd.conf"))
11748 (interfaces '("enp0s25"))))
11752 @deftp {Data Type} dhcpd-configuration
11754 @item @code{package} (default: @code{isc-dhcp})
11755 The package that provides the DHCP daemon. This package is expected to
11756 provide the daemon at @file{sbin/dhcpd} relative to its output
11757 directory. The default package is the
11758 @uref{http://www.isc.org/products/DHCP, ISC's DHCP server}.
11759 @item @code{config-file} (default: @code{#f})
11760 The configuration file to use. This is required. It will be passed to
11761 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
11762 object (@pxref{G-Expressions, file-like objects}). See @code{man
11763 dhcpd.conf} for details on the configuration file syntax.
11764 @item @code{version} (default: @code{"4"})
11765 The DHCP version to use. The ISC DHCP server supports the values ``4'',
11766 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
11767 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
11769 @item @code{run-directory} (default: @code{"/run/dhcpd"})
11770 The run directory to use. At service activation time, this directory
11771 will be created if it does not exist.
11772 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
11773 The PID file to use. This corresponds to the @code{-pf} option of
11774 @code{dhcpd}. See @code{man dhcpd} for details.
11775 @item @code{interfaces} (default: @code{'()})
11776 The names of the network interfaces on which dhcpd should listen for
11777 broadcasts. If this list is not empty, then its elements (which must be
11778 strings) will be appended to the @code{dhcpd} invocation when starting
11779 the daemon. It may not be necessary to explicitly specify any
11780 interfaces here; see @code{man dhcpd} for details.
11784 @defvr {Scheme Variable} static-networking-service-type
11785 This is the type for statically-configured network interfaces.
11786 @c TODO Document <static-networking> data structures.
11789 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
11790 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
11791 [#:requirement @code{'(udev)}]
11792 Return a service that starts @var{interface} with address @var{ip}. If
11793 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
11794 it must be a string specifying the default network gateway. @var{requirement}
11795 can be used to declare a dependency on another service before configuring the
11798 This procedure can be called several times, one for each network
11799 interface of interest. Behind the scenes what it does is extend
11800 @code{static-networking-service-type} with additional network interfaces
11806 (static-networking-service "eno1" "192.168.1.82"
11807 #:gateway "192.168.1.2"
11808 #:name-servers '("192.168.1.2"))
11815 @cindex network management
11816 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
11817 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
11818 management daemon that aims to simplify wired and wireless networking.
11820 This service adds the @var{wicd} package to the global profile, providing
11821 several commands to interact with the daemon and configure networking:
11822 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
11823 and @command{wicd-curses} user interfaces.
11826 @cindex ModemManager
11828 @defvr {Scheme Variable} modem-manager-service-type
11829 This is the service type for the
11830 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
11831 service. The value for this service type is a
11832 @code{modem-manager-configuration} record.
11834 This service is part of @code{%desktop-services} (@pxref{Desktop
11838 @deftp {Data Type} modem-manager-configuration
11839 Data type representing the configuration of ModemManager.
11842 @item @code{modem-manager} (default: @code{modem-manager})
11843 The ModemManager package to use.
11848 @cindex NetworkManager
11850 @defvr {Scheme Variable} network-manager-service-type
11851 This is the service type for the
11852 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
11853 service. The value for this service type is a
11854 @code{network-manager-configuration} record.
11856 This service is part of @code{%desktop-services} (@pxref{Desktop
11860 @deftp {Data Type} network-manager-configuration
11861 Data type representing the configuration of NetworkManager.
11864 @item @code{network-manager} (default: @code{network-manager})
11865 The NetworkManager package to use.
11867 @item @code{dns} (default: @code{"default"})
11868 Processing mode for DNS, which affects how NetworkManager uses the
11869 @code{resolv.conf} configuration file.
11873 NetworkManager will update @code{resolv.conf} to reflect the nameservers
11874 provided by currently active connections.
11877 NetworkManager will run @code{dnsmasq} as a local caching nameserver,
11878 using a "split DNS" configuration if you are connected to a VPN, and
11879 then update @code{resolv.conf} to point to the local nameserver.
11882 NetworkManager will not modify @code{resolv.conf}.
11885 @item @code{vpn-plugins} (default: @code{'()})
11886 This is the list of available plugins for virtual private networks
11887 (VPNs). An example of this is the @code{network-manager-openvpn}
11888 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
11894 @deffn {Scheme Variable} connman-service-type
11895 This is the service type to run @url{https://01.org/connman,Connman},
11896 a network connection manager.
11898 Its value must be an
11899 @code{connman-configuration} record as in this example:
11902 (service connman-service-type
11903 (connman-configuration
11904 (disable-vpn? #t)))
11907 See below for details about @code{connman-configuration}.
11910 @deftp {Data Type} connman-configuration
11911 Data Type representing the configuration of connman.
11914 @item @code{connman} (default: @var{connman})
11915 The connman package to use.
11917 @item @code{disable-vpn?} (default: @code{#f})
11918 When true, disable connman's vpn plugin.
11922 @cindex WPA Supplicant
11923 @defvr {Scheme Variable} wpa-supplicant-service-type
11924 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
11925 supplicant}, an authentication daemon required to authenticate against
11926 encrypted WiFi or ethernet networks.
11929 @deftp {Data Type} wpa-supplicant-configuration
11930 Data type representing the configuration of WPA Supplicant.
11932 It takes the following parameters:
11935 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
11936 The WPA Supplicant package to use.
11938 @item @code{dbus?} (default: @code{#t})
11939 Whether to listen for requests on D-Bus.
11941 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
11942 Where to store the PID file.
11944 @item @code{interface} (default: @code{#f})
11945 If this is set, it must specify the name of a network interface that
11946 WPA supplicant will control.
11948 @item @code{config-file} (default: @code{#f})
11949 Optional configuration file to use.
11951 @item @code{extra-options} (default: @code{'()})
11952 List of additional command-line arguments to pass to the daemon.
11957 @defvr {Scheme Variable} iptables-service-type
11958 This is the service type to set up an iptables configuration. iptables is a
11959 packet filtering framework supported by the Linux kernel. This service
11960 supports configuring iptables for both IPv4 and IPv6. A simple example
11961 configuration rejecting all incoming connections except those to the ssh port
11965 (service iptables-service-type
11966 (iptables-configuration
11967 (ipv4-rules (plain-file "iptables.rules" "*filter
11971 -A INPUT -p tcp --dport 22 -j ACCEPT
11972 -A INPUT -j REJECT --reject-with icmp-port-unreachable
11975 (ipv6-rules (plain-file "ip6tables.rules" "*filter
11979 -A INPUT -p tcp --dport 22 -j ACCEPT
11980 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
11986 @deftp {Data Type} iptables-configuration
11987 The data type representing the configuration of iptables.
11990 @item @code{iptables} (default: @code{iptables})
11991 The iptables package that provides @code{iptables-restore} and
11992 @code{ip6tables-restore}.
11993 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
11994 The iptables rules to use. It will be passed to @code{iptables-restore}.
11995 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
11997 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
11998 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
11999 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12004 @cindex NTP (Network Time Protocol), service
12005 @cindex real time clock
12006 @defvr {Scheme Variable} ntp-service-type
12007 This is the type of the service running the the @uref{http://www.ntp.org,
12008 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
12009 system clock synchronized with that of the specified NTP servers.
12011 The value of this service is an @code{ntpd-configuration} object, as described
12015 @deftp {Data Type} ntp-configuration
12016 This is the data type for the NTP service configuration.
12019 @item @code{servers} (default: @code{%ntp-servers})
12020 This is the list of servers (host names) with which @command{ntpd} will be
12023 @item @code{allow-large-adjustment?} (default: @code{#f})
12024 This determines whether @command{ntpd} is allowed to make an initial
12025 adjustment of more than 1,000 seconds.
12027 @item @code{ntp} (default: @code{ntp})
12028 The NTP package to use.
12032 @defvr {Scheme Variable} %ntp-servers
12033 List of host names used as the default NTP servers. These are servers of the
12034 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
12038 @deffn {Scheme Procedure} openntpd-service-type
12039 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
12040 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
12041 clock synchronized with that of the given servers.
12045 openntpd-service-type
12046 (openntpd-configuration
12047 (listen-on '("127.0.0.1" "::1"))
12048 (sensor '("udcf0 correction 70000"))
12049 (constraint-from '("www.gnu.org"))
12050 (constraints-from '("https://www.google.com/"))
12051 (allow-large-adjustment? #t)))
12056 @deftp {Data Type} openntpd-configuration
12058 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
12059 The openntpd executable to use.
12060 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
12061 A list of local IP addresses or hostnames the ntpd daemon should listen on.
12062 @item @code{query-from} (default: @code{'()})
12063 A list of local IP address the ntpd daemon should use for outgoing queries.
12064 @item @code{sensor} (default: @code{'()})
12065 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
12066 will listen to each sensor that acutally exists and ignore non-existant ones.
12067 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
12069 @item @code{server} (default: @var{%ntp-servers})
12070 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
12071 @item @code{servers} (default: @code{'()})
12072 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
12073 @item @code{constraint-from} (default: @code{'()})
12074 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
12075 This time information is not used for precision but acts as an authenticated
12076 constraint, thereby reducing the impact of unauthenticated NTP
12077 man-in-the-middle attacks.
12078 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
12080 @item @code{constraints-from} (default: @code{'()})
12081 As with constraint from, specify a list of URLs, IP addresses or hostnames of
12082 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
12083 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
12084 @item @code{allow-large-adjustment?} (default: @code{#f})
12085 Determines if @code{ntpd} is allowed to make an initial adjustment of more
12091 @deffn {Scheme variable} inetd-service-type
12092 This service runs the @command{inetd} (@pxref{inetd invocation,,,
12093 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
12094 connections on internet sockets, and lazily starts the specified server
12095 program when a connection is made on one of these sockets.
12097 The value of this service is an @code{inetd-configuration} object. The
12098 following example configures the @command{inetd} daemon to provide the
12099 built-in @command{echo} service, as well as an smtp service which
12100 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
12101 gateway @code{hostname}:
12106 (inetd-configuration
12110 (socket-type 'stream)
12117 (socket-type 'stream)
12121 (program (file-append openssh "/bin/ssh"))
12123 '("ssh" "-qT" "-i" "/path/to/ssh_key"
12124 "-W" "smtp-server:25" "user@@hostname")))))
12127 See below for more details about @code{inetd-configuration}.
12130 @deftp {Data Type} inetd-configuration
12131 Data type representing the configuration of @command{inetd}.
12134 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
12135 The @command{inetd} executable to use.
12137 @item @code{entries} (default: @code{'()})
12138 A list of @command{inetd} service entries. Each entry should be created
12139 by the @code{inetd-entry} constructor.
12143 @deftp {Data Type} inetd-entry
12144 Data type representing an entry in the @command{inetd} configuration.
12145 Each entry corresponds to a socket where @command{inetd} will listen for
12149 @item @code{node} (default: @code{#f})
12150 Optional string, a comma-separated list of local addresses
12151 @command{inetd} should use when listening for this service.
12152 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
12153 description of all options.
12155 A string, the name must correspond to an entry in @code{/etc/services}.
12156 @item @code{socket-type}
12157 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
12159 @item @code{protocol}
12160 A string, must correspond to an entry in @code{/etc/protocols}.
12161 @item @code{wait?} (default: @code{#t})
12162 Whether @command{inetd} should wait for the server to exit before
12163 listening to new service requests.
12165 A string containing the user (and, optionally, group) name of the user
12166 as whom the server should run. The group name can be specified in a
12167 suffix, separated by a colon or period, i.e. @code{"user"},
12168 @code{"user:group"} or @code{"user.group"}.
12169 @item @code{program} (default: @code{"internal"})
12170 The server program which will serve the requests, or @code{"internal"}
12171 if @command{inetd} should use a built-in service.
12172 @item @code{arguments} (default: @code{'()})
12173 A list strings or file-like objects, which are the server program's
12174 arguments, starting with the zeroth argument, i.e. the name of the
12175 program itself. For @command{inetd}'s internal services, this entry
12176 must be @code{'()} or @code{'("internal")}.
12179 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
12180 detailed discussion of each configuration field.
12184 @defvr {Scheme Variable} tor-service-type
12185 This is the type for a service that runs the @uref{https://torproject.org,
12186 Tor} anonymous networking daemon. The service is configured using a
12187 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
12188 @code{tor} unprivileged user, which is a member of the @code{tor} group.
12192 @deffn {Scheme Procedure} tor-service [@var{config-file}] [#:tor @var{tor}]
12193 This procedure is deprecated and will be removed in a future release. Return
12194 a service of the @code{tor-service-type} type. @var{config-file} and
12195 @var{tor} have the same meaning as in @code{<tor-configuration>}.
12198 @deftp {Data Type} tor-configuration
12200 @item @code{tor} (default: @code{tor})
12201 The package that provides the Tor daemon. This package is expected to provide
12202 the daemon at @file{bin/tor} relative to its output directory. The default
12203 package is the @uref{https://www.torproject.org, Tor Project's}
12206 @item @code{config-file} (default: @code{(plain-file "empty" "")})
12207 The configuration file to use. It will be appended to a default configuration
12208 file, and the final configuration file will be passed to @code{tor} via its
12209 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
12210 file-like objects}). See @code{man tor} for details on the configuration file
12213 @item @code{hidden-services} (default: @code{'()})
12214 The list of @code{<hidden-service>} records to use. For any hidden service
12215 you include in this list, appropriate configuration to enable the hidden
12216 service will be automatically added to the default configuration file. You
12217 may conveniently create @code{<hidden-service>} records using the
12218 @code{tor-hidden-service} procedure described below.
12220 @item @code{socks-socket-type} (default: @code{'tcp})
12221 The default socket type that Tor should use for its SOCKS socket. This must
12222 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
12223 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
12224 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
12225 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
12228 If you want to customize the SOCKS socket in more detail, leave
12229 @code{socks-socket-type} at its default value of @code{'tcp} and use
12230 @code{config-file} to override the default by providing your own
12231 @code{SocksPort} option.
12235 @cindex hidden service
12236 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
12237 Define a new Tor @dfn{hidden service} called @var{name} and implementing
12238 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
12241 '((22 "127.0.0.1:22")
12242 (80 "127.0.0.1:8080"))
12245 In this example, port 22 of the hidden service is mapped to local port 22, and
12246 port 80 is mapped to local port 8080.
12248 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
12249 the @file{hostname} file contains the @code{.onion} host name for the hidden
12252 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
12253 project's documentation} for more information.
12256 The @code{(gnu services rsync)} module provides the following services:
12258 You might want an rsync daemon if you have files that you want available
12259 so anyone (or just yourself) can download existing files or upload new
12262 @deffn {Scheme Variable} rsync-service-type
12263 This is the type for the @uref{https://rsync.samba.org, rsync} rsync daemon,
12264 @command{rsync-configuration} record as in this example:
12267 (service rsync-service-type)
12270 See below for details about @code{rsync-configuration}.
12273 @deftp {Data Type} rsync-configuration
12274 Data type representing the configuration for @code{rsync-service}.
12277 @item @code{package} (default: @var{rsync})
12278 @code{rsync} package to use.
12280 @item @code{port-number} (default: @code{873})
12281 TCP port on which @command{rsync} listens for incoming connections. If port
12282 is less than @code{1024} @command{rsync} needs to be started as the
12283 @code{root} user and group.
12285 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
12286 Name of the file where @command{rsync} writes its PID.
12288 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
12289 Name of the file where @command{rsync} writes its lock file.
12291 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
12292 Name of the file where @command{rsync} writes its log file.
12294 @item @code{use-chroot?} (default: @var{#t})
12295 Whether to use chroot for @command{rsync} shared directory.
12297 @item @code{share-path} (default: @file{/srv/rsync})
12298 Location of the @command{rsync} shared directory.
12300 @item @code{share-comment} (default: @code{"Rsync share"})
12301 Comment of the @command{rsync} shared directory.
12303 @item @code{read-only?} (default: @var{#f})
12304 Read-write permissions to shared directory.
12306 @item @code{timeout} (default: @code{300})
12307 I/O timeout in seconds.
12309 @item @code{user} (default: @var{"root"})
12310 Owner of the @code{rsync} process.
12312 @item @code{group} (default: @var{"root"})
12313 Group of the @code{rsync} process.
12315 @item @code{uid} (default: @var{"rsyncd"})
12316 User name or user ID that file transfers to and from that module should take
12317 place as when the daemon was run as @code{root}.
12319 @item @code{gid} (default: @var{"rsyncd"})
12320 Group name or group ID that will be used when accessing the module.
12325 Furthermore, @code{(gnu services ssh)} provides the following services.
12329 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
12330 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
12331 [#:allow-empty-passwords? #f] [#:root-login? #f] @
12332 [#:syslog-output? #t] [#:x11-forwarding? #t] @
12333 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
12334 [#:public-key-authentication? #t] [#:initialize? #t]
12335 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
12336 @var{host-key} must designate a file containing the host key, and readable
12339 When @var{daemonic?} is true, @command{lshd} will detach from the
12340 controlling terminal and log its output to syslogd, unless one sets
12341 @var{syslog-output?} to false. Obviously, it also makes lsh-service
12342 depend on existence of syslogd service. When @var{pid-file?} is true,
12343 @command{lshd} writes its PID to the file called @var{pid-file}.
12345 When @var{initialize?} is true, automatically create the seed and host key
12346 upon service activation if they do not exist yet. This may take long and
12347 require interaction.
12349 When @var{initialize?} is false, it is up to the user to initialize the
12350 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
12351 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
12352 basics,,, lsh, LSH Manual}).
12354 When @var{interfaces} is empty, lshd listens for connections on all the
12355 network interfaces; otherwise, @var{interfaces} must be a list of host names
12358 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
12359 passwords, and @var{root-login?} specifies whether to accept log-ins as
12362 The other options should be self-descriptive.
12367 @deffn {Scheme Variable} openssh-service-type
12368 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
12369 shell daemon, @command{sshd}. Its value must be an
12370 @code{openssh-configuration} record as in this example:
12373 (service openssh-service-type
12374 (openssh-configuration
12375 (x11-forwarding? #t)
12376 (permit-root-login 'without-password)
12378 `(("alice" ,(local-file "alice.pub"))
12379 ("bob" ,(local-file "bob.pub"))))))
12382 See below for details about @code{openssh-configuration}.
12384 This service can be extended with extra authorized keys, as in this
12388 (service-extension openssh-service-type
12389 (const `(("charlie"
12390 ,(local-file "charlie.pub")))))
12394 @deftp {Data Type} openssh-configuration
12395 This is the configuration record for OpenSSH's @command{sshd}.
12398 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
12399 Name of the file where @command{sshd} writes its PID.
12401 @item @code{port-number} (default: @code{22})
12402 TCP port on which @command{sshd} listens for incoming connections.
12404 @item @code{permit-root-login} (default: @code{#f})
12405 This field determines whether and when to allow logins as root. If
12406 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
12407 If it's the symbol @code{'without-password}, then root logins are
12408 permitted but not with password-based authentication.
12410 @item @code{allow-empty-passwords?} (default: @code{#f})
12411 When true, users with empty passwords may log in. When false, they may
12414 @item @code{password-authentication?} (default: @code{#t})
12415 When true, users may log in with their password. When false, they have
12416 other authentication methods.
12418 @item @code{public-key-authentication?} (default: @code{#t})
12419 When true, users may log in using public key authentication. When
12420 false, users have to use other authentication method.
12422 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
12423 This is used only by protocol version 2.
12425 @item @code{x11-forwarding?} (default: @code{#f})
12426 When true, forwarding of X11 graphical client connections is
12427 enabled---in other words, @command{ssh} options @option{-X} and
12428 @option{-Y} will work.
12430 @item @code{allow-agent-forwarding?} (default: @code{#t})
12431 Whether to allow agent forwarding.
12433 @item @code{allow-tcp-forwarding?} (default: @code{#t})
12434 Whether to allow TCP forwarding.
12436 @item @code{gateway-ports?} (default: @code{#f})
12437 Whether to allow gateway ports.
12439 @item @code{challenge-response-authentication?} (default: @code{#f})
12440 Specifies whether challenge response authentication is allowed (e.g. via
12443 @item @code{use-pam?} (default: @code{#t})
12444 Enables the Pluggable Authentication Module interface. If set to
12445 @code{#t}, this will enable PAM authentication using
12446 @code{challenge-response-authentication?} and
12447 @code{password-authentication?}, in addition to PAM account and session
12448 module processing for all authentication types.
12450 Because PAM challenge response authentication usually serves an
12451 equivalent role to password authentication, you should disable either
12452 @code{challenge-response-authentication?} or
12453 @code{password-authentication?}.
12455 @item @code{print-last-log?} (default: @code{#t})
12456 Specifies whether @command{sshd} should print the date and time of the
12457 last user login when a user logs in interactively.
12459 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
12460 Configures external subsystems (e.g. file transfer daemon).
12462 This is a list of two-element lists, each of which containing the
12463 subsystem name and a command (with optional arguments) to execute upon
12466 The command @command{internal-sftp} implements an in-process SFTP
12467 server. Alternately, one can specify the @command{sftp-server} command:
12469 (service openssh-service-type
12470 (openssh-configuration
12472 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
12475 @item @code{accepted-environment} (default: @code{'()})
12476 List of strings describing which environment variables may be exported.
12478 Each string gets on its own line. See the @code{AcceptEnv} option in
12479 @code{man sshd_config}.
12481 This example allows ssh-clients to export the @code{COLORTERM} variable.
12482 It is set by terminal emulators, which support colors. You can use it in
12483 your shell's ressource file to enable colors for the prompt and commands
12484 if this variable is set.
12487 (service openssh-service-type
12488 (openssh-configuration
12489 (accepted-environment '("COLORTERM"))))
12492 @item @code{authorized-keys} (default: @code{'()})
12493 @cindex authorized keys, SSH
12494 @cindex SSH authorized keys
12495 This is the list of authorized keys. Each element of the list is a user
12496 name followed by one or more file-like objects that represent SSH public
12500 (openssh-configuration
12502 `(("rekado" ,(local-file "rekado.pub"))
12503 ("chris" ,(local-file "chris.pub"))
12504 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
12508 registers the specified public keys for user accounts @code{rekado},
12509 @code{chris}, and @code{root}.
12511 Additional authorized keys can be specified @i{via}
12512 @code{service-extension}.
12514 Note that this does @emph{not} interfere with the use of
12515 @file{~/.ssh/authorized_keys}.
12517 @item @code{log-level} (default: @code{'info})
12518 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
12519 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
12520 page for @file{sshd_config} for the full list of level names.
12525 @deffn {Scheme Procedure} dropbear-service [@var{config}]
12526 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
12527 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
12530 For example, to specify a Dropbear service listening on port 1234, add
12531 this call to the operating system's @code{services} field:
12534 (dropbear-service (dropbear-configuration
12535 (port-number 1234)))
12539 @deftp {Data Type} dropbear-configuration
12540 This data type represents the configuration of a Dropbear SSH daemon.
12543 @item @code{dropbear} (default: @var{dropbear})
12544 The Dropbear package to use.
12546 @item @code{port-number} (default: 22)
12547 The TCP port where the daemon waits for incoming connections.
12549 @item @code{syslog-output?} (default: @code{#t})
12550 Whether to enable syslog output.
12552 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
12553 File name of the daemon's PID file.
12555 @item @code{root-login?} (default: @code{#f})
12556 Whether to allow @code{root} logins.
12558 @item @code{allow-empty-passwords?} (default: @code{#f})
12559 Whether to allow empty passwords.
12561 @item @code{password-authentication?} (default: @code{#t})
12562 Whether to enable password-based authentication.
12566 @defvr {Scheme Variable} %facebook-host-aliases
12567 This variable contains a string for use in @file{/etc/hosts}
12568 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
12569 line contains a entry that maps a known server name of the Facebook
12570 on-line service---e.g., @code{www.facebook.com}---to the local
12571 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
12573 This variable is typically used in the @code{hosts-file} field of an
12574 @code{operating-system} declaration (@pxref{operating-system Reference,
12575 @file{/etc/hosts}}):
12578 (use-modules (gnu) (guix))
12581 (host-name "mymachine")
12584 ;; Create a /etc/hosts file with aliases for "localhost"
12585 ;; and "mymachine", as well as for Facebook servers.
12586 (plain-file "hosts"
12587 (string-append (local-host-aliases host-name)
12588 %facebook-host-aliases))))
12591 This mechanism can prevent programs running locally, such as Web
12592 browsers, from accessing Facebook.
12595 The @code{(gnu services avahi)} provides the following definition.
12597 @deffn {Scheme Procedure} avahi-service [#:avahi @var{avahi}] @
12598 [#:host-name #f] [#:publish? #t] [#:ipv4? #t] @
12599 [#:ipv6? #t] [#:wide-area? #f] @
12600 [#:domains-to-browse '()] [#:debug? #f]
12601 Return a service that runs @command{avahi-daemon}, a system-wide
12602 mDNS/DNS-SD responder that allows for service discovery and
12603 "zero-configuration" host name lookups (see @uref{http://avahi.org/}), and
12604 extends the name service cache daemon (nscd) so that it can resolve
12605 @code{.local} host names using
12606 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. Additionally,
12607 add the @var{avahi} package to the system profile so that commands such as
12608 @command{avahi-browse} are directly usable.
12610 If @var{host-name} is different from @code{#f}, use that as the host name to
12611 publish for this machine; otherwise, use the machine's actual host name.
12613 When @var{publish?} is true, publishing of host names and services is allowed;
12614 in particular, avahi-daemon will publish the machine's host name and IP
12615 address via mDNS on the local network.
12617 When @var{wide-area?} is true, DNS-SD over unicast DNS is enabled.
12619 Boolean values @var{ipv4?} and @var{ipv6?} determine whether to use IPv4/IPv6
12623 @deffn {Scheme Variable} openvswitch-service-type
12624 This is the type of the @uref{http://www.openvswitch.org, Open vSwitch}
12625 service, whose value should be an @code{openvswitch-configuration}
12629 @deftp {Data Type} openvswitch-configuration
12630 Data type representing the configuration of Open vSwitch, a multilayer
12631 virtual switch which is designed to enable massive network automation
12632 through programmatic extension.
12635 @item @code{package} (default: @var{openvswitch})
12636 Package object of the Open vSwitch.
12642 @subsubsection X Window
12645 @cindex X Window System
12646 @cindex login manager
12647 Support for the X Window graphical display system---specifically
12648 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
12649 there is no @code{xorg-service} procedure. Instead, the X server is
12650 started by the @dfn{login manager}, by default SLiM.
12652 @cindex window manager
12653 To use X11, you must install at least one @dfn{window manager}---for
12654 example the @code{windowmaker} or @code{openbox} packages---preferably
12655 by adding it to the @code{packages} field of your operating system
12656 definition (@pxref{operating-system Reference, system-wide packages}).
12658 @defvr {Scheme Variable} slim-service-type
12659 This is the type for the SLiM graphical login manager for X11.
12661 @cindex session types (X11)
12662 @cindex X11 session types
12663 SLiM looks for @dfn{session types} described by the @file{.desktop} files in
12664 @file{/run/current-system/profile/share/xsessions} and allows users to
12665 choose a session from the log-in screen using @kbd{F1}. Packages such
12666 as @code{xfce}, @code{sawfish}, and @code{ratpoison} provide
12667 @file{.desktop} files; adding them to the system-wide set of packages
12668 automatically makes them available at the log-in screen.
12670 In addition, @file{~/.xsession} files are honored. When available,
12671 @file{~/.xsession} must be an executable that starts a window manager
12672 and/or other X clients.
12675 @deftp {Data Type} slim-configuration
12676 Data type representing the configuration of @code{slim-service-type}.
12679 @item @code{allow-empty-passwords?} (default: @code{#t})
12680 Whether to allow logins with empty passwords.
12682 @item @code{auto-login?} (default: @code{#f})
12683 @itemx @code{default-user} (default: @code{""})
12684 When @code{auto-login?} is false, SLiM presents a log-in screen.
12686 When @code{auto-login?} is true, SLiM logs in directly as
12687 @code{default-user}.
12689 @item @code{theme} (default: @code{%default-slim-theme})
12690 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
12691 The graphical theme to use and its name.
12693 @item @code{auto-login-session} (default: @code{#f})
12694 If true, this must be the name of the executable to start as the default
12695 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
12697 If false, a session described by one of the available @file{.desktop}
12698 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
12702 You must install at least one window manager in the system profile or in
12703 your user profile. Failing to do that, if @code{auto-login-session} is
12704 false, you will be unable to log in.
12707 @item @code{startx} (default: @code{(xorg-start-command)})
12708 The command used to start the X11 graphical server.
12710 @item @code{xauth} (default: @code{xauth})
12711 The XAuth package to use.
12713 @item @code{shepherd} (default: @code{shepherd})
12714 The Shepherd package used when invoking @command{halt} and
12717 @item @code{sessreg} (default: @code{sessreg})
12718 The sessreg package used in order to register the session.
12720 @item @code{slim} (default: @code{slim})
12721 The SLiM package to use.
12725 @defvr {Scheme Variable} %default-theme
12726 @defvrx {Scheme Variable} %default-theme-name
12727 The default SLiM theme and its name.
12731 @deftp {Data Type} sddm-configuration
12732 This is the data type representing the sddm service configuration.
12735 @item @code{display-server} (default: "x11")
12736 Select display server to use for the greeter. Valid values are "x11"
12739 @item @code{numlock} (default: "on")
12740 Valid values are "on", "off" or "none".
12742 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
12743 Command to run when halting.
12745 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
12746 Command to run when rebooting.
12748 @item @code{theme} (default "maldives")
12749 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
12751 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
12752 Directory to look for themes.
12754 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
12755 Directory to look for faces.
12757 @item @code{default-path} (default "/run/current-system/profile/bin")
12758 Default PATH to use.
12760 @item @code{minimum-uid} (default 1000)
12761 Minimum UID to display in SDDM.
12763 @item @code{maximum-uid} (default 2000)
12764 Maximum UID to display in SDDM
12766 @item @code{remember-last-user?} (default #t)
12767 Remember last user.
12769 @item @code{remember-last-session?} (default #t)
12770 Remember last session.
12772 @item @code{hide-users} (default "")
12773 Usernames to hide from SDDM greeter.
12775 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
12776 Users with shells listed will be hidden from the SDDM greeter.
12778 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
12779 Script to run before starting a wayland session.
12781 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
12782 Directory to look for desktop files starting wayland sessions.
12784 @item @code{xorg-server-path} (default @code{xorg-start-command})
12785 Path to xorg-server.
12787 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
12790 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
12793 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
12794 Script to run after starting xorg-server.
12796 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
12797 Script to run before stopping xorg-server.
12799 @item @code{xsession-command} (default: @code{xinitrc})
12800 Script to run before starting a X session.
12802 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
12803 Directory to look for desktop files starting X sessions.
12805 @item @code{minimum-vt} (default: 7)
12808 @item @code{xserver-arguments} (default "-nolisten tcp")
12809 Arguments to pass to xorg-server.
12811 @item @code{auto-login-user} (default "")
12812 User to use for auto-login.
12814 @item @code{auto-login-session} (default "")
12815 Desktop file to use for auto-login.
12817 @item @code{relogin?} (default #f)
12818 Relogin after logout.
12823 @cindex login manager
12825 @deffn {Scheme Procedure} sddm-service config
12826 Return a service that spawns the SDDM graphical login manager for config of
12827 type @code{<sddm-configuration>}.
12830 (sddm-service (sddm-configuration
12831 (auto-login-user "Alice")
12832 (auto-login-session "xfce.desktop")))
12836 @deffn {Scheme Procedure} xorg-start-command [#:guile] @
12837 [#:modules %default-xorg-modules] @
12838 [#:fonts %default-xorg-fonts] @
12839 [#:configuration-file (xorg-configuration-file @dots{})] @
12840 [#:xorg-server @var{xorg-server}]
12841 Return a @code{startx} script in which @var{modules}, a list of X module
12842 packages, and @var{fonts}, a list of X font directories, are available. See
12843 @code{xorg-wrapper} for more details on the arguments. The result should be
12844 used in place of @code{startx}.
12846 Usually the X server is started by a login manager.
12849 @deffn {Scheme Procedure} xorg-configuration-file @
12850 [#:modules %default-xorg-modules] @
12851 [#:fonts %default-xorg-fonts] @
12852 [#:drivers '()] [#:resolutions '()] [#:extra-config '()]
12853 Return a configuration file for the Xorg server containing search paths for
12854 all the common drivers.
12856 @var{modules} must be a list of @dfn{module packages} loaded by the Xorg
12857 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
12858 @var{fonts} must be a list of font directories to add to the server's
12861 @var{drivers} must be either the empty list, in which case Xorg chooses a
12862 graphics driver automatically, or a list of driver names that will be tried in
12863 this order---e.g., @code{("modesetting" "vesa")}.
12865 Likewise, when @var{resolutions} is the empty list, Xorg chooses an
12866 appropriate screen resolution; otherwise, it must be a list of
12867 resolutions---e.g., @code{((1024 768) (640 480))}.
12869 Last, @var{extra-config} is a list of strings or objects appended to the
12870 configuration file. It is used to pass extra text to be
12871 added verbatim to the configuration file.
12874 @cindex keyboard layout
12875 This procedure is especially useful to configure a different keyboard layout
12876 than the default US keymap. For instance, to use the ``bépo'' keymap by
12877 default on the display manager:
12881 "Section \"InputClass\"
12882 Identifier \"evdev keyboard catchall\"
12884 MatchIsKeyboard \"on\"
12885 Option \"xkb_layout\" \"fr\"
12886 Option \"xkb_variant\" \"bepo\"
12892 (modify-services %desktop-services
12893 (slim-service-type config =>
12894 (slim-configuration
12896 (startx (xorg-start-command
12897 #:configuration-file
12898 (xorg-configuration-file
12900 (list bepo-evdev)))))))))
12903 The @code{MatchIsKeyboard} line specifies that we only apply the configuration
12904 to keyboards. Without this line, other devices such as touchpad may not work
12905 correctly because they will be attached to the wrong driver. In this example,
12906 the user typically used @code{setxkbmap fr bepo} to set their favorite keymap
12907 once logged in. The first argument corresponds to the layout, while the second
12908 argument corresponds to the variant. The @code{xkb_variant} line can be omitted
12909 to select the default variant.
12912 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
12913 Add @var{package}, a package for a screen locker or screen saver whose
12914 command is @var{program}, to the set of setuid programs and add a PAM entry
12915 for it. For example:
12918 (screen-locker-service xlockmore "xlock")
12921 makes the good ol' XlockMore usable.
12925 @node Printing Services
12926 @subsubsection Printing Services
12928 @cindex printer support with CUPS
12929 The @code{(gnu services cups)} module provides a Guix service definition
12930 for the CUPS printing service. To add printer support to a GuixSD
12931 system, add a @code{cups-service} to the operating system definition:
12933 @deffn {Scheme Variable} cups-service-type
12934 The service type for the CUPS print server. Its value should be a valid
12935 CUPS configuration (see below). To use the default settings, simply
12938 (service cups-service-type)
12942 The CUPS configuration controls the basic things about your CUPS
12943 installation: what interfaces it listens on, what to do if a print job
12944 fails, how much logging to do, and so on. To actually add a printer,
12945 you have to visit the @url{http://localhost:631} URL, or use a tool such
12946 as GNOME's printer configuration services. By default, configuring a
12947 CUPS service will generate a self-signed certificate if needed, for
12948 secure connections to the print server.
12950 Suppose you want to enable the Web interface of CUPS and also add
12951 support for Epson printers @i{via} the @code{escpr} package and for HP
12952 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
12953 like this (you need to use the @code{(gnu packages cups)} module):
12956 (service cups-service-type
12957 (cups-configuration
12958 (web-interface? #t)
12960 (list cups-filters escpr hplip-minimal))))
12963 Note: If you wish to use the Qt5 based GUI which comes with the hplip
12964 package then it is suggested that you install the @code{hplip} package,
12965 either in your OS configuration file or as your user.
12967 The available configuration parameters follow. Each parameter
12968 definition is preceded by its type; for example, @samp{string-list foo}
12969 indicates that the @code{foo} parameter should be specified as a list of
12970 strings. There is also a way to specify the configuration as a string,
12971 if you have an old @code{cupsd.conf} file that you want to port over
12972 from some other system; see the end for more details.
12974 @c The following documentation was initially generated by
12975 @c (generate-documentation) in (gnu services cups). Manually maintained
12976 @c documentation is better, so we shouldn't hesitate to edit below as
12977 @c needed. However if the change you want to make to this documentation
12978 @c can be done in an automated way, it's probably easier to change
12979 @c (generate-documentation) than to make it below and have to deal with
12980 @c the churn as CUPS updates.
12983 Available @code{cups-configuration} fields are:
12985 @deftypevr {@code{cups-configuration} parameter} package cups
12989 @deftypevr {@code{cups-configuration} parameter} package-list extensions
12990 Drivers and other extensions to the CUPS package.
12993 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
12994 Configuration of where to write logs, what directories to use for print
12995 spools, and related privileged configuration parameters.
12997 Available @code{files-configuration} fields are:
12999 @deftypevr {@code{files-configuration} parameter} log-location access-log
13000 Defines the access log filename. Specifying a blank filename disables
13001 access log generation. The value @code{stderr} causes log entries to be
13002 sent to the standard error file when the scheduler is running in the
13003 foreground, or to the system log daemon when run in the background. The
13004 value @code{syslog} causes log entries to be sent to the system log
13005 daemon. The server name may be included in filenames using the string
13006 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
13008 Defaults to @samp{"/var/log/cups/access_log"}.
13011 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
13012 Where CUPS should cache data.
13014 Defaults to @samp{"/var/cache/cups"}.
13017 @deftypevr {@code{files-configuration} parameter} string config-file-perm
13018 Specifies the permissions for all configuration files that the scheduler
13021 Note that the permissions for the printers.conf file are currently
13022 masked to only allow access from the scheduler user (typically root).
13023 This is done because printer device URIs sometimes contain sensitive
13024 authentication information that should not be generally known on the
13025 system. There is no way to disable this security feature.
13027 Defaults to @samp{"0640"}.
13030 @deftypevr {@code{files-configuration} parameter} log-location error-log
13031 Defines the error log filename. Specifying a blank filename disables
13032 access log generation. The value @code{stderr} causes log entries to be
13033 sent to the standard error file when the scheduler is running in the
13034 foreground, or to the system log daemon when run in the background. The
13035 value @code{syslog} causes log entries to be sent to the system log
13036 daemon. The server name may be included in filenames using the string
13037 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
13039 Defaults to @samp{"/var/log/cups/error_log"}.
13042 @deftypevr {@code{files-configuration} parameter} string fatal-errors
13043 Specifies which errors are fatal, causing the scheduler to exit. The
13048 No errors are fatal.
13051 All of the errors below are fatal.
13054 Browsing initialization errors are fatal, for example failed connections
13055 to the DNS-SD daemon.
13058 Configuration file syntax errors are fatal.
13061 Listen or Port errors are fatal, except for IPv6 failures on the
13062 loopback or @code{any} addresses.
13065 Log file creation or write errors are fatal.
13068 Bad startup file permissions are fatal, for example shared TLS
13069 certificate and key files with world-read permissions.
13072 Defaults to @samp{"all -browse"}.
13075 @deftypevr {@code{files-configuration} parameter} boolean file-device?
13076 Specifies whether the file pseudo-device can be used for new printer
13077 queues. The URI @uref{file:///dev/null} is always allowed.
13079 Defaults to @samp{#f}.
13082 @deftypevr {@code{files-configuration} parameter} string group
13083 Specifies the group name or ID that will be used when executing external
13086 Defaults to @samp{"lp"}.
13089 @deftypevr {@code{files-configuration} parameter} string log-file-perm
13090 Specifies the permissions for all log files that the scheduler writes.
13092 Defaults to @samp{"0644"}.
13095 @deftypevr {@code{files-configuration} parameter} log-location page-log
13096 Defines the page log filename. Specifying a blank filename disables
13097 access log generation. The value @code{stderr} causes log entries to be
13098 sent to the standard error file when the scheduler is running in the
13099 foreground, or to the system log daemon when run in the background. The
13100 value @code{syslog} causes log entries to be sent to the system log
13101 daemon. The server name may be included in filenames using the string
13102 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
13104 Defaults to @samp{"/var/log/cups/page_log"}.
13107 @deftypevr {@code{files-configuration} parameter} string remote-root
13108 Specifies the username that is associated with unauthenticated accesses
13109 by clients claiming to be the root user. The default is @code{remroot}.
13111 Defaults to @samp{"remroot"}.
13114 @deftypevr {@code{files-configuration} parameter} file-name request-root
13115 Specifies the directory that contains print jobs and other HTTP request
13118 Defaults to @samp{"/var/spool/cups"}.
13121 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
13122 Specifies the level of security sandboxing that is applied to print
13123 filters, backends, and other child processes of the scheduler; either
13124 @code{relaxed} or @code{strict}. This directive is currently only
13125 used/supported on macOS.
13127 Defaults to @samp{strict}.
13130 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
13131 Specifies the location of TLS certificates and private keys. CUPS will
13132 look for public and private keys in this directory: a @code{.crt} files
13133 for PEM-encoded certificates and corresponding @code{.key} files for
13134 PEM-encoded private keys.
13136 Defaults to @samp{"/etc/cups/ssl"}.
13139 @deftypevr {@code{files-configuration} parameter} file-name server-root
13140 Specifies the directory containing the server configuration files.
13142 Defaults to @samp{"/etc/cups"}.
13145 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
13146 Specifies whether the scheduler calls fsync(2) after writing
13147 configuration or state files.
13149 Defaults to @samp{#f}.
13152 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
13153 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
13156 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
13157 Specifies the directory where temporary files are stored.
13159 Defaults to @samp{"/var/spool/cups/tmp"}.
13162 @deftypevr {@code{files-configuration} parameter} string user
13163 Specifies the user name or ID that is used when running external
13166 Defaults to @samp{"lp"}.
13170 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
13171 Specifies the logging level for the AccessLog file. The @code{config}
13172 level logs when printers and classes are added, deleted, or modified and
13173 when configuration files are accessed or updated. The @code{actions}
13174 level logs when print jobs are submitted, held, released, modified, or
13175 canceled, and any of the conditions for @code{config}. The @code{all}
13176 level logs all requests.
13178 Defaults to @samp{actions}.
13181 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
13182 Specifies whether to purge job history data automatically when it is no
13183 longer required for quotas.
13185 Defaults to @samp{#f}.
13188 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
13189 Specifies which protocols to use for local printer sharing.
13191 Defaults to @samp{dnssd}.
13194 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
13195 Specifies whether the CUPS web interface is advertised.
13197 Defaults to @samp{#f}.
13200 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
13201 Specifies whether shared printers are advertised.
13203 Defaults to @samp{#f}.
13206 @deftypevr {@code{cups-configuration} parameter} string classification
13207 Specifies the security classification of the server. Any valid banner
13208 name can be used, including "classified", "confidential", "secret",
13209 "topsecret", and "unclassified", or the banner can be omitted to disable
13210 secure printing functions.
13212 Defaults to @samp{""}.
13215 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
13216 Specifies whether users may override the classification (cover page) of
13217 individual print jobs using the @code{job-sheets} option.
13219 Defaults to @samp{#f}.
13222 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
13223 Specifies the default type of authentication to use.
13225 Defaults to @samp{Basic}.
13228 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
13229 Specifies whether encryption will be used for authenticated requests.
13231 Defaults to @samp{Required}.
13234 @deftypevr {@code{cups-configuration} parameter} string default-language
13235 Specifies the default language to use for text and web content.
13237 Defaults to @samp{"en"}.
13240 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
13241 Specifies the default paper size for new print queues. @samp{"Auto"}
13242 uses a locale-specific default, while @samp{"None"} specifies there is
13243 no default paper size. Specific size names are typically
13244 @samp{"Letter"} or @samp{"A4"}.
13246 Defaults to @samp{"Auto"}.
13249 @deftypevr {@code{cups-configuration} parameter} string default-policy
13250 Specifies the default access policy to use.
13252 Defaults to @samp{"default"}.
13255 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
13256 Specifies whether local printers are shared by default.
13258 Defaults to @samp{#t}.
13261 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
13262 Specifies the delay for updating of configuration and state files, in
13263 seconds. A value of 0 causes the update to happen as soon as possible,
13264 typically within a few milliseconds.
13266 Defaults to @samp{30}.
13269 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
13270 Specifies what to do when an error occurs. Possible values are
13271 @code{abort-job}, which will discard the failed print job;
13272 @code{retry-job}, which will retry the job at a later time;
13273 @code{retry-this-job}, which retries the failed job immediately; and
13274 @code{stop-printer}, which stops the printer.
13276 Defaults to @samp{stop-printer}.
13279 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
13280 Specifies the maximum cost of filters that are run concurrently, which
13281 can be used to minimize disk, memory, and CPU resource problems. A
13282 limit of 0 disables filter limiting. An average print to a
13283 non-PostScript printer needs a filter limit of about 200. A PostScript
13284 printer needs about half that (100). Setting the limit below these
13285 thresholds will effectively limit the scheduler to printing a single job
13288 Defaults to @samp{0}.
13291 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
13292 Specifies the scheduling priority of filters that are run to print a
13293 job. The nice value ranges from 0, the highest priority, to 19, the
13296 Defaults to @samp{0}.
13299 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
13300 Specifies whether to do reverse lookups on connecting clients. The
13301 @code{double} setting causes @code{cupsd} to verify that the hostname
13302 resolved from the address matches one of the addresses returned for that
13303 hostname. Double lookups also prevent clients with unregistered
13304 addresses from connecting to your server. Only set this option to
13305 @code{#t} or @code{double} if absolutely required.
13307 Defaults to @samp{#f}.
13310 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
13311 Specifies the number of seconds to wait before killing the filters and
13312 backend associated with a canceled or held job.
13314 Defaults to @samp{30}.
13317 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
13318 Specifies the interval between retries of jobs in seconds. This is
13319 typically used for fax queues but can also be used with normal print
13320 queues whose error policy is @code{retry-job} or
13321 @code{retry-current-job}.
13323 Defaults to @samp{30}.
13326 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
13327 Specifies the number of retries that are done for jobs. This is
13328 typically used for fax queues but can also be used with normal print
13329 queues whose error policy is @code{retry-job} or
13330 @code{retry-current-job}.
13332 Defaults to @samp{5}.
13335 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
13336 Specifies whether to support HTTP keep-alive connections.
13338 Defaults to @samp{#t}.
13341 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
13342 Specifies how long an idle client connection remains open, in seconds.
13344 Defaults to @samp{30}.
13347 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
13348 Specifies the maximum size of print files, IPP requests, and HTML form
13349 data. A limit of 0 disables the limit check.
13351 Defaults to @samp{0}.
13354 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
13355 Listens on the specified interfaces for connections. Valid values are
13356 of the form @var{address}:@var{port}, where @var{address} is either an
13357 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
13358 indicate all addresses. Values can also be file names of local UNIX
13359 domain sockets. The Listen directive is similar to the Port directive
13360 but allows you to restrict access to specific interfaces or networks.
13363 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
13364 Specifies the number of pending connections that will be allowed. This
13365 normally only affects very busy servers that have reached the MaxClients
13366 limit, but can also be triggered by large numbers of simultaneous
13367 connections. When the limit is reached, the operating system will
13368 refuse additional connections until the scheduler can accept the pending
13371 Defaults to @samp{128}.
13374 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
13375 Specifies a set of additional access controls.
13377 Available @code{location-access-controls} fields are:
13379 @deftypevr {@code{location-access-controls} parameter} file-name path
13380 Specifies the URI path to which the access control applies.
13383 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
13384 Access controls for all access to this path, in the same format as the
13385 @code{access-controls} of @code{operation-access-control}.
13387 Defaults to @samp{()}.
13390 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
13391 Access controls for method-specific access to this path.
13393 Defaults to @samp{()}.
13395 Available @code{method-access-controls} fields are:
13397 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
13398 If @code{#t}, apply access controls to all methods except the listed
13399 methods. Otherwise apply to only the listed methods.
13401 Defaults to @samp{#f}.
13404 @deftypevr {@code{method-access-controls} parameter} method-list methods
13405 Methods to which this access control applies.
13407 Defaults to @samp{()}.
13410 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
13411 Access control directives, as a list of strings. Each string should be
13412 one directive, such as "Order allow,deny".
13414 Defaults to @samp{()}.
13419 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
13420 Specifies the number of debugging messages that are retained for logging
13421 if an error occurs in a print job. Debug messages are logged regardless
13422 of the LogLevel setting.
13424 Defaults to @samp{100}.
13427 @deftypevr {@code{cups-configuration} parameter} log-level log-level
13428 Specifies the level of logging for the ErrorLog file. The value
13429 @code{none} stops all logging while @code{debug2} logs everything.
13431 Defaults to @samp{info}.
13434 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
13435 Specifies the format of the date and time in the log files. The value
13436 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
13438 Defaults to @samp{standard}.
13441 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
13442 Specifies the maximum number of simultaneous clients that are allowed by
13445 Defaults to @samp{100}.
13448 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
13449 Specifies the maximum number of simultaneous clients that are allowed
13450 from a single address.
13452 Defaults to @samp{100}.
13455 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
13456 Specifies the maximum number of copies that a user can print of each
13459 Defaults to @samp{9999}.
13462 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
13463 Specifies the maximum time a job may remain in the @code{indefinite}
13464 hold state before it is canceled. A value of 0 disables cancellation of
13467 Defaults to @samp{0}.
13470 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
13471 Specifies the maximum number of simultaneous jobs that are allowed. Set
13472 to 0 to allow an unlimited number of jobs.
13474 Defaults to @samp{500}.
13477 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
13478 Specifies the maximum number of simultaneous jobs that are allowed per
13479 printer. A value of 0 allows up to MaxJobs jobs per printer.
13481 Defaults to @samp{0}.
13484 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
13485 Specifies the maximum number of simultaneous jobs that are allowed per
13486 user. A value of 0 allows up to MaxJobs jobs per user.
13488 Defaults to @samp{0}.
13491 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
13492 Specifies the maximum time a job may take to print before it is
13493 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
13495 Defaults to @samp{10800}.
13498 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
13499 Specifies the maximum size of the log files before they are rotated, in
13500 bytes. The value 0 disables log rotation.
13502 Defaults to @samp{1048576}.
13505 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
13506 Specifies the maximum amount of time to allow between files in a
13507 multiple file print job, in seconds.
13509 Defaults to @samp{300}.
13512 @deftypevr {@code{cups-configuration} parameter} string page-log-format
13513 Specifies the format of PageLog lines. Sequences beginning with percent
13514 (@samp{%}) characters are replaced with the corresponding information,
13515 while all other characters are copied literally. The following percent
13516 sequences are recognized:
13520 insert a single percent character
13523 insert the value of the specified IPP attribute
13526 insert the number of copies for the current page
13529 insert the current page number
13532 insert the current date and time in common log format
13538 insert the printer name
13541 insert the username
13544 A value of the empty string disables page logging. The string @code{%p
13545 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
13546 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
13549 Defaults to @samp{""}.
13552 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
13553 Passes the specified environment variable(s) to child processes; a list
13556 Defaults to @samp{()}.
13559 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
13560 Specifies named access control policies.
13562 Available @code{policy-configuration} fields are:
13564 @deftypevr {@code{policy-configuration} parameter} string name
13565 Name of the policy.
13568 @deftypevr {@code{policy-configuration} parameter} string job-private-access
13569 Specifies an access list for a job's private values. @code{@@ACL} maps
13570 to the printer's requesting-user-name-allowed or
13571 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
13572 owner. @code{@@SYSTEM} maps to the groups listed for the
13573 @code{system-group} field of the @code{files-config} configuration,
13574 which is reified into the @code{cups-files.conf(5)} file. Other
13575 possible elements of the access list include specific user names, and
13576 @code{@@@var{group}} to indicate members of a specific group. The
13577 access list may also be simply @code{all} or @code{default}.
13579 Defaults to @samp{"@@OWNER @@SYSTEM"}.
13582 @deftypevr {@code{policy-configuration} parameter} string job-private-values
13583 Specifies the list of job values to make private, or @code{all},
13584 @code{default}, or @code{none}.
13586 Defaults to @samp{"job-name job-originating-host-name
13587 job-originating-user-name phone"}.
13590 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
13591 Specifies an access list for a subscription's private values.
13592 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
13593 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
13594 owner. @code{@@SYSTEM} maps to the groups listed for the
13595 @code{system-group} field of the @code{files-config} configuration,
13596 which is reified into the @code{cups-files.conf(5)} file. Other
13597 possible elements of the access list include specific user names, and
13598 @code{@@@var{group}} to indicate members of a specific group. The
13599 access list may also be simply @code{all} or @code{default}.
13601 Defaults to @samp{"@@OWNER @@SYSTEM"}.
13604 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
13605 Specifies the list of job values to make private, or @code{all},
13606 @code{default}, or @code{none}.
13608 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
13609 notify-subscriber-user-name notify-user-data"}.
13612 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
13613 Access control by IPP operation.
13615 Defaults to @samp{()}.
13619 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
13620 Specifies whether job files (documents) are preserved after a job is
13621 printed. If a numeric value is specified, job files are preserved for
13622 the indicated number of seconds after printing. Otherwise a boolean
13623 value applies indefinitely.
13625 Defaults to @samp{86400}.
13628 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
13629 Specifies whether the job history is preserved after a job is printed.
13630 If a numeric value is specified, the job history is preserved for the
13631 indicated number of seconds after printing. If @code{#t}, the job
13632 history is preserved until the MaxJobs limit is reached.
13634 Defaults to @samp{#t}.
13637 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
13638 Specifies the amount of time to wait for job completion before
13639 restarting the scheduler.
13641 Defaults to @samp{30}.
13644 @deftypevr {@code{cups-configuration} parameter} string rip-cache
13645 Specifies the maximum amount of memory to use when converting documents
13646 into bitmaps for a printer.
13648 Defaults to @samp{"128m"}.
13651 @deftypevr {@code{cups-configuration} parameter} string server-admin
13652 Specifies the email address of the server administrator.
13654 Defaults to @samp{"root@@localhost.localdomain"}.
13657 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
13658 The ServerAlias directive is used for HTTP Host header validation when
13659 clients connect to the scheduler from external interfaces. Using the
13660 special name @code{*} can expose your system to known browser-based DNS
13661 rebinding attacks, even when accessing sites through a firewall. If the
13662 auto-discovery of alternate names does not work, we recommend listing
13663 each alternate name with a ServerAlias directive instead of using
13666 Defaults to @samp{*}.
13669 @deftypevr {@code{cups-configuration} parameter} string server-name
13670 Specifies the fully-qualified host name of the server.
13672 Defaults to @samp{"localhost"}.
13675 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
13676 Specifies what information is included in the Server header of HTTP
13677 responses. @code{None} disables the Server header. @code{ProductOnly}
13678 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
13679 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
13680 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
13681 the output of the @code{uname} command. @code{Full} reports @code{CUPS
13682 2.0.0 (@var{uname}) IPP/2.0}.
13684 Defaults to @samp{Minimal}.
13687 @deftypevr {@code{cups-configuration} parameter} string set-env
13688 Set the specified environment variable to be passed to child processes.
13690 Defaults to @samp{"variable value"}.
13693 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
13694 Listens on the specified interfaces for encrypted connections. Valid
13695 values are of the form @var{address}:@var{port}, where @var{address} is
13696 either an IPv6 address enclosed in brackets, an IPv4 address, or
13697 @code{*} to indicate all addresses.
13699 Defaults to @samp{()}.
13702 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
13703 Sets encryption options. By default, CUPS only supports encryption
13704 using TLS v1.0 or higher using known secure cipher suites. The
13705 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
13706 required for some older clients that do not implement newer ones. The
13707 @code{AllowSSL3} option enables SSL v3.0, which is required for some
13708 older clients that do not support TLS v1.0.
13710 Defaults to @samp{()}.
13713 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
13714 Specifies whether the scheduler requires clients to strictly adhere to
13715 the IPP specifications.
13717 Defaults to @samp{#f}.
13720 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
13721 Specifies the HTTP request timeout, in seconds.
13723 Defaults to @samp{300}.
13727 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
13728 Specifies whether the web interface is enabled.
13730 Defaults to @samp{#f}.
13733 At this point you're probably thinking ``oh dear, Guix manual, I like
13734 you but you can stop already with the configuration options''. Indeed.
13735 However, one more point: it could be that you have an existing
13736 @code{cupsd.conf} that you want to use. In that case, you can pass an
13737 @code{opaque-cups-configuration} as the configuration of a
13738 @code{cups-service-type}.
13740 Available @code{opaque-cups-configuration} fields are:
13742 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
13746 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
13747 The contents of the @code{cupsd.conf}, as a string.
13750 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
13751 The contents of the @code{cups-files.conf} file, as a string.
13754 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
13755 strings of the same name, you could instantiate a CUPS service like
13759 (service cups-service-type
13760 (opaque-cups-configuration
13761 (cupsd.conf cupsd.conf)
13762 (cups-files.conf cups-files.conf)))
13766 @node Desktop Services
13767 @subsubsection Desktop Services
13769 The @code{(gnu services desktop)} module provides services that are
13770 usually useful in the context of a ``desktop'' setup---that is, on a
13771 machine running a graphical display server, possibly with graphical user
13772 interfaces, etc. It also defines services that provide specific desktop
13773 environments like GNOME, XFCE or MATE.
13775 To simplify things, the module defines a variable containing the set of
13776 services that users typically expect on a machine with a graphical
13777 environment and networking:
13779 @defvr {Scheme Variable} %desktop-services
13780 This is a list of services that builds upon @var{%base-services} and
13781 adds or adjusts services for a typical ``desktop'' setup.
13783 In particular, it adds a graphical login manager (@pxref{X Window,
13784 @code{slim-service}}), screen lockers, a network management tool
13785 (@pxref{Networking Services, @code{network-manager-service-type}}), energy and color
13786 management services, the @code{elogind} login and seat manager, the
13787 Polkit privilege service, the GeoClue location service, the
13788 AccountsService daemon that allows authorized users change system
13789 passwords, an NTP client (@pxref{Networking Services}), the Avahi
13790 daemon, and has the name service switch service configured to be able to
13791 use @code{nss-mdns} (@pxref{Name Service Switch, mDNS}).
13794 The @var{%desktop-services} variable can be used as the @code{services}
13795 field of an @code{operating-system} declaration (@pxref{operating-system
13796 Reference, @code{services}}).
13798 Additionally, the @code{gnome-desktop-service},
13799 @code{xfce-desktop-service}, @code{mate-desktop-service} and
13800 @code{enlightenment-desktop-service-type} procedures can add GNOME, XFCE, MATE
13801 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
13802 services like the backlight adjustment helpers and the power management
13803 utilities are added to the system, extending @code{polkit} and @code{dbus}
13804 appropriately, allowing GNOME to operate with elevated privileges on a
13805 limited number of special-purpose system interfaces. Additionally,
13806 adding a service made by @code{gnome-desktop-service} adds the GNOME
13807 metapackage to the system profile. Likewise, adding the XFCE service
13808 not only adds the @code{xfce} metapackage to the system profile, but it
13809 also gives the Thunar file manager the ability to open a ``root-mode''
13810 file management window, if the user authenticates using the
13811 administrator's password via the standard polkit graphical interface.
13812 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
13813 appropriately, allowing MATE to operate with elevated privileges on a
13814 limited number of special-purpose system interfaces. Additionally,
13815 adding a service made by @code{mate-desktop-service} adds the MATE
13816 metapackage to the system profile. ``Adding ENLIGHTENMENT'' means that
13817 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
13818 are set as setuid, allowing Enlightenment's screen locker and other
13819 functionality to work as expetected.
13821 The desktop environments in Guix use the Xorg display server by
13822 default. If you'd like to use the newer display server protocol
13823 called Wayland, you need to use the @code{sddm-service} instead of the
13824 @code{slim-service} for the graphical login manager. You should then
13825 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
13826 also try starting GNOME on Wayland manually from a TTY with the
13827 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
13828 gnome-session``. Currently only GNOME has support for Wayland.
13830 @deffn {Scheme Procedure} gnome-desktop-service
13831 Return a service that adds the @code{gnome} package to the system
13832 profile, and extends polkit with the actions from
13833 @code{gnome-settings-daemon}.
13836 @deffn {Scheme Procedure} xfce-desktop-service
13837 Return a service that adds the @code{xfce} package to the system profile,
13838 and extends polkit with the ability for @code{thunar} to manipulate the
13839 file system as root from within a user session, after the user has
13840 authenticated with the administrator's password.
13843 @deffn {Scheme Procedure} mate-desktop-service
13844 Return a service that adds the @code{mate} package to the system
13845 profile, and extends polkit with the actions from
13846 @code{mate-settings-daemon}.
13849 @deffn {Scheme Procedure} enlightenment-desktop-service-type
13850 Return a service that adds the @code{enlightenment} package to the system
13851 profile, and extends dbus with actions from @code{efl}.
13854 @deftp {Data Type} enlightenment-desktop-service-configuration
13856 @item @code{enlightenment} (default @code{enlightenment})
13857 The enlightenment package to use.
13861 Because the GNOME, XFCE and MATE desktop services pull in so many packages,
13862 the default @code{%desktop-services} variable doesn't include any of
13863 them by default. To add GNOME, XFCE or MATE, just @code{cons} them onto
13864 @code{%desktop-services} in the @code{services} field of your
13865 @code{operating-system}:
13868 (use-modules (gnu))
13869 (use-service-modules desktop)
13872 ;; cons* adds items to the list given as its last argument.
13873 (services (cons* (gnome-desktop-service)
13874 (xfce-desktop-service)
13875 %desktop-services))
13879 These desktop environments will then be available as options in the
13880 graphical login window.
13882 The actual service definitions included in @code{%desktop-services} and
13883 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
13884 are described below.
13886 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
13887 Return a service that runs the ``system bus'', using @var{dbus}, with
13888 support for @var{services}.
13890 @uref{http://dbus.freedesktop.org/, D-Bus} is an inter-process communication
13891 facility. Its system bus is used to allow system services to communicate
13892 and to be notified of system-wide events.
13894 @var{services} must be a list of packages that provide an
13895 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
13896 and policy files. For example, to allow avahi-daemon to use the system bus,
13897 @var{services} must be equal to @code{(list avahi)}.
13900 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
13901 Return a service that runs the @code{elogind} login and
13902 seat management daemon. @uref{https://github.com/elogind/elogind,
13903 Elogind} exposes a D-Bus interface that can be used to know which users
13904 are logged in, know what kind of sessions they have open, suspend the
13905 system, inhibit system suspend, reboot the system, and other tasks.
13907 Elogind handles most system-level power events for a computer, for
13908 example suspending the system when a lid is closed, or shutting it down
13909 when the power button is pressed.
13911 The @var{config} keyword argument specifies the configuration for
13912 elogind, and should be the result of an @code{(elogind-configuration
13913 (@var{parameter} @var{value})...)} invocation. Available parameters and
13914 their default values are:
13917 @item kill-user-processes?
13919 @item kill-only-users
13921 @item kill-exclude-users
13923 @item inhibit-delay-max-seconds
13925 @item handle-power-key
13927 @item handle-suspend-key
13929 @item handle-hibernate-key
13931 @item handle-lid-switch
13933 @item handle-lid-switch-docked
13935 @item power-key-ignore-inhibited?
13937 @item suspend-key-ignore-inhibited?
13939 @item hibernate-key-ignore-inhibited?
13941 @item lid-switch-ignore-inhibited?
13943 @item holdoff-timeout-seconds
13947 @item idle-action-seconds
13949 @item runtime-directory-size-percent
13951 @item runtime-directory-size
13955 @item suspend-state
13956 @code{("mem" "standby" "freeze")}
13959 @item hibernate-state
13961 @item hibernate-mode
13962 @code{("platform" "shutdown")}
13963 @item hybrid-sleep-state
13965 @item hybrid-sleep-mode
13966 @code{("suspend" "platform" "shutdown")}
13970 @deffn {Scheme Procedure} accountsservice-service @
13971 [#:accountsservice @var{accountsservice}]
13972 Return a service that runs AccountsService, a system service that can
13973 list available accounts, change their passwords, and so on.
13974 AccountsService integrates with PolicyKit to enable unprivileged users
13975 to acquire the capability to modify their system configuration.
13976 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
13977 accountsservice web site} for more information.
13979 The @var{accountsservice} keyword argument is the @code{accountsservice}
13980 package to expose as a service.
13983 @deffn {Scheme Procedure} polkit-service @
13984 [#:polkit @var{polkit}]
13985 Return a service that runs the
13986 @uref{http://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
13987 management service}, which allows system administrators to grant access to
13988 privileged operations in a structured way. By querying the Polkit service, a
13989 privileged system component can know when it should grant additional
13990 capabilities to ordinary users. For example, an ordinary user can be granted
13991 the capability to suspend the system if the user is logged in locally.
13994 @deffn {Scheme Procedure} upower-service [#:upower @var{upower}] @
13995 [#:watts-up-pro? #f] @
13996 [#:poll-batteries? #t] @
13997 [#:ignore-lid? #f] @
13998 [#:use-percentage-for-policy? #f] @
13999 [#:percentage-low 10] @
14000 [#:percentage-critical 3] @
14001 [#:percentage-action 2] @
14002 [#:time-low 1200] @
14003 [#:time-critical 300] @
14004 [#:time-action 120] @
14005 [#:critical-power-action 'hybrid-sleep]
14006 Return a service that runs @uref{http://upower.freedesktop.org/,
14007 @command{upowerd}}, a system-wide monitor for power consumption and battery
14008 levels, with the given configuration settings. It implements the
14009 @code{org.freedesktop.UPower} D-Bus interface, and is notably used by
14013 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
14014 Return a service for @uref{http://udisks.freedesktop.org/docs/latest/,
14015 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
14016 notifications and ways to mount/unmount disks. Programs that talk to UDisks
14017 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
14020 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
14021 Return a service that runs @command{colord}, a system service with a D-Bus
14022 interface to manage the color profiles of input and output devices such as
14023 screens and scanners. It is notably used by the GNOME Color Manager graphical
14024 tool. See @uref{http://www.freedesktop.org/software/colord/, the colord web
14025 site} for more information.
14028 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
14029 Return a configuration allowing an application to access GeoClue
14030 location data. @var{name} is the Desktop ID of the application, without
14031 the @code{.desktop} part. If @var{allowed?} is true, the application
14032 will have access to location information by default. The boolean
14033 @var{system?} value indicates whether an application is a system component
14034 or not. Finally @var{users} is a list of UIDs of all users for which
14035 this application is allowed location info access. An empty users list
14036 means that all users are allowed.
14039 @defvr {Scheme Variable} %standard-geoclue-applications
14040 The standard list of well-known GeoClue application configurations,
14041 granting authority to the GNOME date-and-time utility to ask for the
14042 current location in order to set the time zone, and allowing the
14043 IceCat and Epiphany web browsers to request location information.
14044 IceCat and Epiphany both query the user before allowing a web page to
14045 know the user's location.
14048 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
14049 [#:whitelist '()] @
14050 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
14051 [#:submit-data? #f]
14052 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
14053 [#:submission-nick "geoclue"] @
14054 [#:applications %standard-geoclue-applications]
14055 Return a service that runs the GeoClue location service. This service
14056 provides a D-Bus interface to allow applications to request access to a
14057 user's physical location, and optionally to add information to online
14058 location databases. See
14059 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
14060 web site} for more information.
14063 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
14064 [@w{#:auto-enable? #f}]
14065 Return a service that runs the @command{bluetoothd} daemon, which
14066 manages all the Bluetooth devices and provides a number of D-Bus
14067 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
14068 powered automatically at boot, which can be useful when using a
14069 bluetooth keyboard or mouse.
14071 Users need to be in the @code{lp} group to access the D-Bus service.
14074 @node Sound Services
14075 @subsubsection Sound Services
14077 @cindex sound support
14079 @cindex PulseAudio, sound support
14081 The @code{(gnu services sound)} module provides a service to configure the
14082 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
14083 preferred ALSA output driver.
14085 @deffn {Scheme Variable} alsa-service-type
14086 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
14087 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
14088 configuration file. The value for this type is a @command{alsa-configuration}
14089 record as in this example:
14092 (service alsa-service-type)
14095 See below for details about @code{alsa-configuration}.
14098 @deftp {Data Type} alsa-configuration
14099 Data type representing the configuration for @code{alsa-service}.
14102 @item @code{alsa-plugins} (default: @var{alsa-plugins})
14103 @code{alsa-plugins} package to use.
14105 @item @code{pulseaudio?} (default: @var{#t})
14106 Whether ALSA applications should transparently be made to use the
14107 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
14109 Using PulseAudio allows you to run several sound-producing applications
14110 at the same time and to individual control them @i{via}
14111 @command{pavucontrol}, among other things.
14113 @item @code{extra-options} (default: @var{""})
14114 String to append to the @file{/etc/asound.conf} file.
14119 Individual users who want to override the system configuration of ALSA can do
14120 it with the @file{~/.asoundrc} file:
14123 # In guix, we have to specify the absolute path for plugins.
14125 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
14128 # Routing ALSA to jack:
14129 # <http://jackaudio.org/faq/routing_alsa.html>.
14133 0 system:playback_1
14134 1 system:playback_2
14151 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
14155 @node Database Services
14156 @subsubsection Database Services
14160 The @code{(gnu services databases)} module provides the following services.
14162 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
14163 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
14164 [#:port 5432] [#:locale ``en_US.utf8'']
14165 Return a service that runs @var{postgresql}, the PostgreSQL database
14168 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
14169 creates a database cluster with @var{locale} as the default
14170 locale, stored in @var{data-directory}. It then listens on @var{port}.
14173 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
14174 Return a service that runs @command{mysqld}, the MySQL or MariaDB
14177 The optional @var{config} argument specifies the configuration for
14178 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
14181 @deftp {Data Type} mysql-configuration
14182 Data type representing the configuration of @var{mysql-service}.
14185 @item @code{mysql} (default: @var{mariadb})
14186 Package object of the MySQL database server, can be either @var{mariadb}
14189 For MySQL, a temporary root password will be displayed at activation time.
14190 For MariaDB, the root password is empty.
14192 @item @code{port} (default: @code{3306})
14193 TCP port on which the database server listens for incoming connections.
14197 @defvr {Scheme Variable} memcached-service-type
14198 This is the service type for the @uref{https://memcached.org/,
14199 Memcached} service, which provides a distributed in memory cache. The
14200 value for the service type is a @code{memcached-configuration} object.
14204 (service memcached-service-type)
14207 @deftp {Data Type} memcached-configuration
14208 Data type representing the configuration of memcached.
14211 @item @code{memcached} (default: @code{memcached})
14212 The Memcached package to use.
14214 @item @code{interfaces} (default: @code{'("0.0.0.0")})
14215 Network interfaces on which to listen.
14217 @item @code{tcp-port} (default: @code{11211})
14218 Port on which to accept connections on,
14220 @item @code{udp-port} (default: @code{11211})
14221 Port on which to accept UDP connections on, a value of 0 will disable
14222 listening on a UDP socket.
14224 @item @code{additional-options} (default: @code{'()})
14225 Additional command line options to pass to @code{memcached}.
14229 @defvr {Scheme Variable} mongodb-service-type
14230 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
14231 The value for the service type is a @code{mongodb-configuration} object.
14235 (service mongodb-service-type)
14238 @deftp {Data Type} mongodb-configuration
14239 Data type representing the configuration of mongodb.
14242 @item @code{mongodb} (default: @code{mongodb})
14243 The MongoDB package to use.
14245 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
14246 The configuration file for MongoDB.
14248 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
14249 This value is used to create the directory, so that it exists and is
14250 owned by the mongodb user. It should match the data-directory which
14251 MongoDB is configured to use through the configuration file.
14255 @defvr {Scheme Variable} redis-service-type
14256 This is the service type for the @uref{https://redis.io/, Redis}
14257 key/value store, whose value is a @code{redis-configuration} object.
14260 @deftp {Data Type} redis-configuration
14261 Data type representing the configuration of redis.
14264 @item @code{redis} (default: @code{redis})
14265 The Redis package to use.
14267 @item @code{bind} (default: @code{"127.0.0.1"})
14268 Network interface on which to listen.
14270 @item @code{port} (default: @code{6379})
14271 Port on which to accept connections on, a value of 0 will disable
14272 listening on a TCP socket.
14274 @item @code{working-directory} (default: @code{"/var/lib/redis"})
14275 Directory in which to store the database and related files.
14279 @node Mail Services
14280 @subsubsection Mail Services
14284 The @code{(gnu services mail)} module provides Guix service definitions
14285 for email services: IMAP, POP3, and LMTP servers, as well as mail
14286 transport agents (MTAs). Lots of acronyms! These services are detailed
14287 in the subsections below.
14289 @subsubheading Dovecot Service
14291 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
14292 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
14295 By default, Dovecot does not need much configuration; the default
14296 configuration object created by @code{(dovecot-configuration)} will
14297 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
14298 certificate will be generated for TLS-protected connections, though
14299 Dovecot will also listen on cleartext ports by default. There are a
14300 number of options, though, which mail administrators might need to change,
14301 and as is the case with other services, Guix allows the system
14302 administrator to specify these parameters via a uniform Scheme interface.
14304 For example, to specify that mail is located at @code{maildir~/.mail},
14305 one would instantiate the Dovecot service like this:
14308 (dovecot-service #:config
14309 (dovecot-configuration
14310 (mail-location "maildir:~/.mail")))
14313 The available configuration parameters follow. Each parameter
14314 definition is preceded by its type; for example, @samp{string-list foo}
14315 indicates that the @code{foo} parameter should be specified as a list of
14316 strings. There is also a way to specify the configuration as a string,
14317 if you have an old @code{dovecot.conf} file that you want to port over
14318 from some other system; see the end for more details.
14320 @c The following documentation was initially generated by
14321 @c (generate-documentation) in (gnu services mail). Manually maintained
14322 @c documentation is better, so we shouldn't hesitate to edit below as
14323 @c needed. However if the change you want to make to this documentation
14324 @c can be done in an automated way, it's probably easier to change
14325 @c (generate-documentation) than to make it below and have to deal with
14326 @c the churn as dovecot updates.
14328 Available @code{dovecot-configuration} fields are:
14330 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
14331 The dovecot package.
14334 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
14335 A list of IPs or hosts where to listen for connections. @samp{*}
14336 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
14337 interfaces. If you want to specify non-default ports or anything more
14338 complex, customize the address and port fields of the
14339 @samp{inet-listener} of the specific services you are interested in.
14342 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
14343 List of protocols we want to serve. Available protocols include
14344 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
14346 Available @code{protocol-configuration} fields are:
14348 @deftypevr {@code{protocol-configuration} parameter} string name
14349 The name of the protocol.
14352 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
14353 UNIX socket path to the master authentication server to find users.
14354 This is used by imap (for shared users) and lda.
14355 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
14358 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
14359 Space separated list of plugins to load.
14362 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
14363 Maximum number of IMAP connections allowed for a user from each IP
14364 address. NOTE: The username is compared case-sensitively.
14365 Defaults to @samp{10}.
14370 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
14371 List of services to enable. Available services include @samp{imap},
14372 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
14375 Available @code{service-configuration} fields are:
14377 @deftypevr {@code{service-configuration} parameter} string kind
14378 The service kind. Valid values include @code{director},
14379 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
14380 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
14381 @code{tcpwrap}, @code{quota-warning}, or anything else.
14384 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
14385 Listeners for the service. A listener is either a
14386 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
14387 an @code{inet-listener-configuration}.
14388 Defaults to @samp{()}.
14390 Available @code{unix-listener-configuration} fields are:
14392 @deftypevr {@code{unix-listener-configuration} parameter} string path
14393 Path to the file, relative to @code{base-dir} field. This is also used as
14397 @deftypevr {@code{unix-listener-configuration} parameter} string mode
14398 The access mode for the socket.
14399 Defaults to @samp{"0600"}.
14402 @deftypevr {@code{unix-listener-configuration} parameter} string user
14403 The user to own the socket.
14404 Defaults to @samp{""}.
14407 @deftypevr {@code{unix-listener-configuration} parameter} string group
14408 The group to own the socket.
14409 Defaults to @samp{""}.
14413 Available @code{fifo-listener-configuration} fields are:
14415 @deftypevr {@code{fifo-listener-configuration} parameter} string path
14416 Path to the file, relative to @code{base-dir} field. This is also used as
14420 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
14421 The access mode for the socket.
14422 Defaults to @samp{"0600"}.
14425 @deftypevr {@code{fifo-listener-configuration} parameter} string user
14426 The user to own the socket.
14427 Defaults to @samp{""}.
14430 @deftypevr {@code{fifo-listener-configuration} parameter} string group
14431 The group to own the socket.
14432 Defaults to @samp{""}.
14436 Available @code{inet-listener-configuration} fields are:
14438 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
14439 The protocol to listen for.
14442 @deftypevr {@code{inet-listener-configuration} parameter} string address
14443 The address on which to listen, or empty for all addresses.
14444 Defaults to @samp{""}.
14447 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
14448 The port on which to listen.
14451 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
14452 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
14454 Defaults to @samp{#t}.
14459 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
14460 Maximum number of simultaneous client connections per process. Once
14461 this number of connections is received, the next incoming connection
14462 will prompt Dovecot to spawn another process. If set to 0,
14463 @code{default-client-limit} is used instead.
14465 Defaults to @samp{0}.
14469 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
14470 Number of connections to handle before starting a new process.
14471 Typically the only useful values are 0 (unlimited) or 1. 1 is more
14472 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
14473 Defaults to @samp{1}.
14477 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
14478 Maximum number of processes that can exist for this service. If set to
14479 0, @code{default-process-limit} is used instead.
14481 Defaults to @samp{0}.
14485 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
14486 Number of processes to always keep waiting for more connections.
14487 Defaults to @samp{0}.
14490 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
14491 If you set @samp{service-count 0}, you probably need to grow
14493 Defaults to @samp{256000000}.
14498 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
14499 Dict configuration, as created by the @code{dict-configuration}
14502 Available @code{dict-configuration} fields are:
14504 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
14505 A list of key-value pairs that this dict should hold.
14506 Defaults to @samp{()}.
14511 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
14512 A list of passdb configurations, each one created by the
14513 @code{passdb-configuration} constructor.
14515 Available @code{passdb-configuration} fields are:
14517 @deftypevr {@code{passdb-configuration} parameter} string driver
14518 The driver that the passdb should use. Valid values include
14519 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
14521 Defaults to @samp{"pam"}.
14524 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
14525 Space separated list of arguments to the passdb driver.
14526 Defaults to @samp{""}.
14531 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
14532 List of userdb configurations, each one created by the
14533 @code{userdb-configuration} constructor.
14535 Available @code{userdb-configuration} fields are:
14537 @deftypevr {@code{userdb-configuration} parameter} string driver
14538 The driver that the userdb should use. Valid values include
14539 @samp{passwd} and @samp{static}.
14540 Defaults to @samp{"passwd"}.
14543 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
14544 Space separated list of arguments to the userdb driver.
14545 Defaults to @samp{""}.
14548 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
14549 Override fields from passwd.
14550 Defaults to @samp{()}.
14555 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
14556 Plug-in configuration, created by the @code{plugin-configuration}
14560 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
14561 List of namespaces. Each item in the list is created by the
14562 @code{namespace-configuration} constructor.
14564 Available @code{namespace-configuration} fields are:
14566 @deftypevr {@code{namespace-configuration} parameter} string name
14567 Name for this namespace.
14570 @deftypevr {@code{namespace-configuration} parameter} string type
14571 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
14572 Defaults to @samp{"private"}.
14575 @deftypevr {@code{namespace-configuration} parameter} string separator
14576 Hierarchy separator to use. You should use the same separator for
14577 all namespaces or some clients get confused. @samp{/} is usually a good
14578 one. The default however depends on the underlying mail storage
14580 Defaults to @samp{""}.
14583 @deftypevr {@code{namespace-configuration} parameter} string prefix
14584 Prefix required to access this namespace. This needs to be
14585 different for all namespaces. For example @samp{Public/}.
14586 Defaults to @samp{""}.
14589 @deftypevr {@code{namespace-configuration} parameter} string location
14590 Physical location of the mailbox. This is in the same format as
14591 mail_location, which is also the default for it.
14592 Defaults to @samp{""}.
14595 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
14596 There can be only one INBOX, and this setting defines which
14598 Defaults to @samp{#f}.
14601 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
14602 If namespace is hidden, it's not advertised to clients via NAMESPACE
14603 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
14604 useful when converting from another server with different namespaces
14605 which you want to deprecate but still keep working. For example you can
14606 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
14608 Defaults to @samp{#f}.
14611 @deftypevr {@code{namespace-configuration} parameter} boolean list?
14612 Show the mailboxes under this namespace with the LIST command. This
14613 makes the namespace visible for clients that do not support the NAMESPACE
14614 extension. The special @code{children} value lists child mailboxes, but
14615 hides the namespace prefix.
14616 Defaults to @samp{#t}.
14619 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
14620 Namespace handles its own subscriptions. If set to @code{#f}, the
14621 parent namespace handles them. The empty prefix should always have this
14623 Defaults to @samp{#t}.
14626 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
14627 List of predefined mailboxes in this namespace.
14628 Defaults to @samp{()}.
14630 Available @code{mailbox-configuration} fields are:
14632 @deftypevr {@code{mailbox-configuration} parameter} string name
14633 Name for this mailbox.
14636 @deftypevr {@code{mailbox-configuration} parameter} string auto
14637 @samp{create} will automatically create this mailbox.
14638 @samp{subscribe} will both create and subscribe to the mailbox.
14639 Defaults to @samp{"no"}.
14642 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
14643 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
14644 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
14645 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
14646 Defaults to @samp{()}.
14653 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
14654 Base directory where to store runtime data.
14655 Defaults to @samp{"/var/run/dovecot/"}.
14658 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
14659 Greeting message for clients.
14660 Defaults to @samp{"Dovecot ready."}.
14663 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
14664 List of trusted network ranges. Connections from these IPs are
14665 allowed to override their IP addresses and ports (for logging and for
14666 authentication checks). @samp{disable-plaintext-auth} is also ignored
14667 for these networks. Typically you would specify your IMAP proxy servers
14669 Defaults to @samp{()}.
14672 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
14673 List of login access check sockets (e.g. tcpwrap).
14674 Defaults to @samp{()}.
14677 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
14678 Show more verbose process titles (in ps). Currently shows user name
14679 and IP address. Useful for seeing who is actually using the IMAP
14680 processes (e.g. shared mailboxes or if the same uid is used for multiple
14682 Defaults to @samp{#f}.
14685 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
14686 Should all processes be killed when Dovecot master process shuts down.
14687 Setting this to @code{#f} means that Dovecot can be upgraded without
14688 forcing existing client connections to close (although that could also
14689 be a problem if the upgrade is e.g. due to a security fix).
14690 Defaults to @samp{#t}.
14693 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
14694 If non-zero, run mail commands via this many connections to doveadm
14695 server, instead of running them directly in the same process.
14696 Defaults to @samp{0}.
14699 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
14700 UNIX socket or host:port used for connecting to doveadm server.
14701 Defaults to @samp{"doveadm-server"}.
14704 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
14705 List of environment variables that are preserved on Dovecot startup
14706 and passed down to all of its child processes. You can also give
14707 key=value pairs to always set specific settings.
14710 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
14711 Disable LOGIN command and all other plaintext authentications unless
14712 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
14713 matches the local IP (i.e. you're connecting from the same computer),
14714 the connection is considered secure and plaintext authentication is
14715 allowed. See also ssl=required setting.
14716 Defaults to @samp{#t}.
14719 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
14720 Authentication cache size (e.g. @samp{#e10e6}). 0 means it's disabled.
14721 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
14722 for caching to be used.
14723 Defaults to @samp{0}.
14726 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
14727 Time to live for cached data. After TTL expires the cached record
14728 is no longer used, *except* if the main database lookup returns internal
14729 failure. We also try to handle password changes automatically: If
14730 user's previous authentication was successful, but this one wasn't, the
14731 cache isn't used. For now this works only with plaintext
14733 Defaults to @samp{"1 hour"}.
14736 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
14737 TTL for negative hits (user not found, password mismatch).
14738 0 disables caching them completely.
14739 Defaults to @samp{"1 hour"}.
14742 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
14743 List of realms for SASL authentication mechanisms that need them.
14744 You can leave it empty if you don't want to support multiple realms.
14745 Many clients simply use the first one listed here, so keep the default
14747 Defaults to @samp{()}.
14750 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
14751 Default realm/domain to use if none was specified. This is used for
14752 both SASL realms and appending @@domain to username in plaintext
14754 Defaults to @samp{""}.
14757 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
14758 List of allowed characters in username. If the user-given username
14759 contains a character not listed in here, the login automatically fails.
14760 This is just an extra check to make sure user can't exploit any
14761 potential quote escaping vulnerabilities with SQL/LDAP databases. If
14762 you want to allow all characters, set this value to empty.
14763 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
14766 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
14767 Username character translations before it's looked up from
14768 databases. The value contains series of from -> to characters. For
14769 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
14770 translated to @samp{@@}.
14771 Defaults to @samp{""}.
14774 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
14775 Username formatting before it's looked up from databases. You can
14776 use the standard variables here, e.g. %Lu would lowercase the username,
14777 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
14778 change the @samp{@@} into @samp{-AT-}. This translation is done after
14779 @samp{auth-username-translation} changes.
14780 Defaults to @samp{"%Lu"}.
14783 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
14784 If you want to allow master users to log in by specifying the master
14785 username within the normal username string (i.e. not using SASL
14786 mechanism's support for it), you can specify the separator character
14787 here. The format is then <username><separator><master username>.
14788 UW-IMAP uses @samp{*} as the separator, so that could be a good
14790 Defaults to @samp{""}.
14793 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
14794 Username to use for users logging in with ANONYMOUS SASL
14796 Defaults to @samp{"anonymous"}.
14799 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
14800 Maximum number of dovecot-auth worker processes. They're used to
14801 execute blocking passdb and userdb queries (e.g. MySQL and PAM).
14802 They're automatically created and destroyed as needed.
14803 Defaults to @samp{30}.
14806 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
14807 Host name to use in GSSAPI principal names. The default is to use
14808 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
14809 allow all keytab entries.
14810 Defaults to @samp{""}.
14813 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
14814 Kerberos keytab to use for the GSSAPI mechanism. Will use the
14815 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
14816 need to change the auth service to run as root to be able to read this
14818 Defaults to @samp{""}.
14821 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
14822 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
14823 and @samp{ntlm-auth} helper.
14824 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
14825 Defaults to @samp{#f}.
14828 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
14829 Path for Samba's @samp{ntlm-auth} helper binary.
14830 Defaults to @samp{"/usr/bin/ntlm_auth"}.
14833 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
14834 Time to delay before replying to failed authentications.
14835 Defaults to @samp{"2 secs"}.
14838 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
14839 Require a valid SSL client certificate or the authentication
14841 Defaults to @samp{#f}.
14844 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
14845 Take the username from client's SSL certificate, using
14846 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
14848 Defaults to @samp{#f}.
14851 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
14852 List of wanted authentication mechanisms. Supported mechanisms are:
14853 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
14854 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
14855 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
14856 @samp{disable-plaintext-auth} setting.
14859 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
14860 List of IPs or hostnames to all director servers, including ourself.
14861 Ports can be specified as ip:port. The default port is the same as what
14862 director service's @samp{inet-listener} is using.
14863 Defaults to @samp{()}.
14866 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
14867 List of IPs or hostnames to all backend mail servers. Ranges are
14868 allowed too, like 10.0.0.10-10.0.0.30.
14869 Defaults to @samp{()}.
14872 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
14873 How long to redirect users to a specific server after it no longer
14874 has any connections.
14875 Defaults to @samp{"15 min"}.
14878 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
14879 How the username is translated before being hashed. Useful values
14880 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
14881 are shared within domain.
14882 Defaults to @samp{"%Lu"}.
14885 @deftypevr {@code{dovecot-configuration} parameter} string log-path
14886 Log file to use for error messages. @samp{syslog} logs to syslog,
14887 @samp{/dev/stderr} logs to stderr.
14888 Defaults to @samp{"syslog"}.
14891 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
14892 Log file to use for informational messages. Defaults to
14894 Defaults to @samp{""}.
14897 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
14898 Log file to use for debug messages. Defaults to
14899 @samp{info-log-path}.
14900 Defaults to @samp{""}.
14903 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
14904 Syslog facility to use if you're logging to syslog. Usually if you
14905 don't want to use @samp{mail}, you'll use local0..local7. Also other
14906 standard facilities are supported.
14907 Defaults to @samp{"mail"}.
14910 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
14911 Log unsuccessful authentication attempts and the reasons why they
14913 Defaults to @samp{#f}.
14916 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose-passwords?
14917 In case of password mismatches, log the attempted password. Valid
14918 values are no, plain and sha1. sha1 can be useful for detecting brute
14919 force password attempts vs. user simply trying the same password over
14920 and over again. You can also truncate the value to n chars by appending
14921 ":n" (e.g. sha1:6).
14922 Defaults to @samp{#f}.
14925 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
14926 Even more verbose logging for debugging purposes. Shows for example
14928 Defaults to @samp{#f}.
14931 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
14932 In case of password mismatches, log the passwords and used scheme so
14933 the problem can be debugged. Enabling this also enables
14935 Defaults to @samp{#f}.
14938 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
14939 Enable mail process debugging. This can help you figure out why
14940 Dovecot isn't finding your mails.
14941 Defaults to @samp{#f}.
14944 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
14945 Show protocol level SSL errors.
14946 Defaults to @samp{#f}.
14949 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
14950 Prefix for each line written to log file. % codes are in
14951 strftime(3) format.
14952 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
14955 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
14956 List of elements we want to log. The elements which have a
14957 non-empty variable value are joined together to form a comma-separated
14961 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
14962 Login log format. %s contains @samp{login-log-format-elements}
14963 string, %$ contains the data we want to log.
14964 Defaults to @samp{"%$: %s"}.
14967 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
14968 Log prefix for mail processes. See doc/wiki/Variables.txt for list
14969 of possible variables you can use.
14970 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
14973 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
14974 Format to use for logging mail deliveries. You can use variables:
14977 Delivery status message (e.g. @samp{saved to INBOX})
14989 Defaults to @samp{"msgid=%m: %$"}.
14992 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
14993 Location for users' mailboxes. The default is empty, which means
14994 that Dovecot tries to find the mailboxes automatically. This won't work
14995 if the user doesn't yet have any mail, so you should explicitly tell
14996 Dovecot the full location.
14998 If you're using mbox, giving a path to the INBOX
14999 file (e.g. /var/mail/%u) isn't enough. You'll also need to tell Dovecot
15000 where the other mailboxes are kept. This is called the "root mail
15001 directory", and it must be the first path given in the
15002 @samp{mail-location} setting.
15004 There are a few special variables you can use, eg.:
15010 user part in user@@domain, same as %u if there's no domain
15012 domain part in user@@domain, empty if there's no domain
15017 See doc/wiki/Variables.txt for full list. Some examples:
15019 @item maildir:~/Maildir
15020 @item mbox:~/mail:INBOX=/var/mail/%u
15021 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
15023 Defaults to @samp{""}.
15026 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
15027 System user and group used to access mails. If you use multiple,
15028 userdb can override these by returning uid or gid fields. You can use
15029 either numbers or names. <doc/wiki/UserIds.txt>.
15030 Defaults to @samp{""}.
15033 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
15035 Defaults to @samp{""}.
15038 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
15039 Group to enable temporarily for privileged operations. Currently
15040 this is used only with INBOX when either its initial creation or
15041 dotlocking fails. Typically this is set to "mail" to give access to
15043 Defaults to @samp{""}.
15046 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
15047 Grant access to these supplementary groups for mail processes.
15048 Typically these are used to set up access to shared mailboxes. Note
15049 that it may be dangerous to set these if users can create
15050 symlinks (e.g. if "mail" group is set here, ln -s /var/mail ~/mail/var
15051 could allow a user to delete others' mailboxes, or ln -s
15052 /secret/shared/box ~/mail/mybox would allow reading it).
15053 Defaults to @samp{""}.
15056 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
15057 Allow full file system access to clients. There's no access checks
15058 other than what the operating system does for the active UID/GID. It
15059 works with both maildir and mboxes, allowing you to prefix mailboxes
15060 names with e.g. /path/ or ~user/.
15061 Defaults to @samp{#f}.
15064 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
15065 Don't use mmap() at all. This is required if you store indexes to
15066 shared file systems (NFS or clustered file system).
15067 Defaults to @samp{#f}.
15070 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
15071 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
15072 supports @samp{O_EXCL} since version 3, so this should be safe to use
15073 nowadays by default.
15074 Defaults to @samp{#t}.
15077 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
15078 When to use fsync() or fdatasync() calls:
15081 Whenever necessary to avoid losing important data
15083 Useful with e.g. NFS when write()s are delayed
15085 Never use it (best performance, but crashes can lose data).
15087 Defaults to @samp{"optimized"}.
15090 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
15091 Mail storage exists in NFS. Set this to yes to make Dovecot flush
15092 NFS caches whenever needed. If you're using only a single mail server
15094 Defaults to @samp{#f}.
15097 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
15098 Mail index files also exist in NFS. Setting this to yes requires
15099 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
15100 Defaults to @samp{#f}.
15103 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
15104 Locking method for index files. Alternatives are fcntl, flock and
15105 dotlock. Dotlocking uses some tricks which may create more disk I/O
15106 than other locking methods. NFS users: flock doesn't work, remember to
15107 change @samp{mmap-disable}.
15108 Defaults to @samp{"fcntl"}.
15111 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
15112 Directory in which LDA/LMTP temporarily stores incoming mails >128
15114 Defaults to @samp{"/tmp"}.
15117 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
15118 Valid UID range for users. This is mostly to make sure that users can't
15119 log in as daemons or other system users. Note that denying root logins is
15120 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
15122 Defaults to @samp{500}.
15125 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
15127 Defaults to @samp{0}.
15130 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
15131 Valid GID range for users. Users having non-valid GID as primary group ID
15132 aren't allowed to log in. If user belongs to supplementary groups with
15133 non-valid GIDs, those groups are not set.
15134 Defaults to @samp{1}.
15137 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
15139 Defaults to @samp{0}.
15142 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
15143 Maximum allowed length for mail keyword name. It's only forced when
15144 trying to create new keywords.
15145 Defaults to @samp{50}.
15148 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
15149 List of directories under which chrooting is allowed for mail
15150 processes (i.e. /var/mail will allow chrooting to /var/mail/foo/bar
15151 too). This setting doesn't affect @samp{login-chroot}
15152 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
15153 "/./" in home dirs are ignored. WARNING: Never add directories here
15154 which local users can modify, that may lead to root exploit. Usually
15155 this should be done only if you don't allow shell access for users.
15156 <doc/wiki/Chrooting.txt>.
15157 Defaults to @samp{()}.
15160 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
15161 Default chroot directory for mail processes. This can be overridden
15162 for specific users in user database by giving /./ in user's home
15163 directory (e.g. /home/./user chroots into /home). Note that usually
15164 there is no real need to do chrooting, Dovecot doesn't allow users to
15165 access files outside their mail directory anyway. If your home
15166 directories are prefixed with the chroot directory, append "/." to
15167 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
15168 Defaults to @samp{""}.
15171 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
15172 UNIX socket path to master authentication server to find users.
15173 This is used by imap (for shared users) and lda.
15174 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
15177 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
15178 Directory where to look up mail plugins.
15179 Defaults to @samp{"/usr/lib/dovecot"}.
15182 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
15183 List of plugins to load for all services. Plugins specific to IMAP,
15184 LDA, etc. are added to this list in their own .conf files.
15185 Defaults to @samp{()}.
15188 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
15189 The minimum number of mails in a mailbox before updates are done to
15190 cache file. This allows optimizing Dovecot's behavior to do less disk
15191 writes at the cost of more disk reads.
15192 Defaults to @samp{0}.
15195 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
15196 When IDLE command is running, mailbox is checked once in a while to
15197 see if there are any new mails or other changes. This setting defines
15198 the minimum time to wait between those checks. Dovecot can also use
15199 dnotify, inotify and kqueue to find out immediately when changes
15201 Defaults to @samp{"30 secs"}.
15204 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
15205 Save mails with CR+LF instead of plain LF. This makes sending those
15206 mails take less CPU, especially with sendfile() syscall with Linux and
15207 FreeBSD. But it also creates a bit more disk I/O which may just make it
15208 slower. Also note that if other software reads the mboxes/maildirs,
15209 they may handle the extra CRs wrong and cause problems.
15210 Defaults to @samp{#f}.
15213 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
15214 By default LIST command returns all entries in maildir beginning
15215 with a dot. Enabling this option makes Dovecot return only entries
15216 which are directories. This is done by stat()ing each entry, so it
15217 causes more disk I/O.
15218 (For systems setting struct @samp{dirent->d_type} this check is free
15219 and it's done always regardless of this setting).
15220 Defaults to @samp{#f}.
15223 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
15224 When copying a message, do it with hard links whenever possible.
15225 This makes the performance much better, and it's unlikely to have any
15227 Defaults to @samp{#t}.
15230 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
15231 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
15232 directory only when its mtime changes unexpectedly or when we can't find
15233 the mail otherwise.
15234 Defaults to @samp{#f}.
15237 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
15238 Which locking methods to use for locking mbox. There are four
15243 Create <mailbox>.lock file. This is the oldest and most NFS-safe
15244 solution. If you want to use /var/mail/ like directory, the users will
15245 need write access to that directory.
15247 Same as dotlock, but if it fails because of permissions or because there
15248 isn't enough disk space, just skip it.
15250 Use this if possible. Works with NFS too if lockd is used.
15252 May not exist in all systems. Doesn't work with NFS.
15254 May not exist in all systems. Doesn't work with NFS.
15257 You can use multiple locking methods; if you do the order they're declared
15258 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
15259 locking methods as well. Some operating systems don't allow using some of
15260 them simultaneously.
15263 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
15267 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
15268 Maximum time to wait for lock (all of them) before aborting.
15269 Defaults to @samp{"5 mins"}.
15272 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
15273 If dotlock exists but the mailbox isn't modified in any way,
15274 override the lock file after this much time.
15275 Defaults to @samp{"2 mins"}.
15278 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
15279 When mbox changes unexpectedly we have to fully read it to find out
15280 what changed. If the mbox is large this can take a long time. Since
15281 the change is usually just a newly appended mail, it'd be faster to
15282 simply read the new mails. If this setting is enabled, Dovecot does
15283 this but still safely fallbacks to re-reading the whole mbox file
15284 whenever something in mbox isn't how it's expected to be. The only real
15285 downside to this setting is that if some other MUA changes message
15286 flags, Dovecot doesn't notice it immediately. Note that a full sync is
15287 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
15288 Defaults to @samp{#t}.
15291 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
15292 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
15293 EXAMINE, EXPUNGE or CHECK commands. If this is set,
15294 @samp{mbox-dirty-syncs} is ignored.
15295 Defaults to @samp{#f}.
15298 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
15299 Delay writing mbox headers until doing a full write sync (EXPUNGE
15300 and CHECK commands and when closing the mailbox). This is especially
15301 useful for POP3 where clients often delete all mails. The downside is
15302 that our changes aren't immediately visible to other MUAs.
15303 Defaults to @samp{#t}.
15306 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
15307 If mbox size is smaller than this (e.g. 100k), don't write index
15308 files. If an index file already exists it's still read, just not
15310 Defaults to @samp{0}.
15313 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
15314 Maximum dbox file size until it's rotated.
15315 Defaults to @samp{10000000}.
15318 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
15319 Maximum dbox file age until it's rotated. Typically in days. Day
15320 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
15322 Defaults to @samp{"1d"}.
15325 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
15326 When creating new mdbox files, immediately preallocate their size to
15327 @samp{mdbox-rotate-size}. This setting currently works only in Linux
15328 with some file systems (ext4, xfs).
15329 Defaults to @samp{#f}.
15332 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
15333 sdbox and mdbox support saving mail attachments to external files,
15334 which also allows single instance storage for them. Other backends
15335 don't support this for now.
15337 WARNING: This feature hasn't been tested much yet. Use at your own risk.
15339 Directory root where to store mail attachments. Disabled, if empty.
15340 Defaults to @samp{""}.
15343 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
15344 Attachments smaller than this aren't saved externally. It's also
15345 possible to write a plugin to disable saving specific attachments
15347 Defaults to @samp{128000}.
15350 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
15351 File system backend to use for saving attachments:
15354 No SiS done by Dovecot (but this might help FS's own deduplication)
15356 SiS with immediate byte-by-byte comparison during saving
15357 @item sis-queue posix
15358 SiS with delayed comparison and deduplication.
15360 Defaults to @samp{"sis posix"}.
15363 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
15364 Hash format to use in attachment filenames. You can add any text and
15365 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
15366 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
15367 truncated, e.g. @code{%@{sha256:80@}} returns only first 80 bits.
15368 Defaults to @samp{"%@{sha1@}"}.
15371 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
15373 Defaults to @samp{100}.
15376 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
15378 Defaults to @samp{1000}.
15381 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
15382 Default VSZ (virtual memory size) limit for service processes.
15383 This is mainly intended to catch and kill processes that leak memory
15384 before they eat up everything.
15385 Defaults to @samp{256000000}.
15388 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
15389 Login user is internally used by login processes. This is the most
15390 untrusted user in Dovecot system. It shouldn't have access to anything
15392 Defaults to @samp{"dovenull"}.
15395 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
15396 Internal user is used by unprivileged processes. It should be
15397 separate from login user, so that login processes can't disturb other
15399 Defaults to @samp{"dovecot"}.
15402 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
15403 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
15404 Defaults to @samp{"required"}.
15407 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
15408 PEM encoded X.509 SSL/TLS certificate (public key).
15409 Defaults to @samp{"</etc/dovecot/default.pem"}.
15412 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
15413 PEM encoded SSL/TLS private key. The key is opened before
15414 dropping root privileges, so keep the key file unreadable by anyone but
15416 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
15419 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
15420 If key file is password protected, give the password here.
15421 Alternatively give it when starting dovecot with -p parameter. Since
15422 this file is often world-readable, you may want to place this setting
15423 instead to a different.
15424 Defaults to @samp{""}.
15427 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
15428 PEM encoded trusted certificate authority. Set this only if you
15429 intend to use @samp{ssl-verify-client-cert? #t}. The file should
15430 contain the CA certificate(s) followed by the matching
15431 CRL(s). (e.g. @samp{ssl-ca </etc/ssl/certs/ca.pem}).
15432 Defaults to @samp{""}.
15435 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
15436 Require that CRL check succeeds for client certificates.
15437 Defaults to @samp{#t}.
15440 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
15441 Request client to send a certificate. If you also want to require
15442 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
15443 Defaults to @samp{#f}.
15446 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
15447 Which field from certificate to use for username. commonName and
15448 x500UniqueIdentifier are the usual choices. You'll also need to set
15449 @samp{auth-ssl-username-from-cert? #t}.
15450 Defaults to @samp{"commonName"}.
15453 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
15454 Minimum SSL protocol version to accept.
15455 Defaults to @samp{"TLSv1"}.
15458 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
15459 SSL ciphers to use.
15460 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
15463 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
15464 SSL crypto device to use, for valid values run "openssl engine".
15465 Defaults to @samp{""}.
15468 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
15469 Address to use when sending rejection mails.
15470 %d expands to recipient domain.
15471 Defaults to @samp{"postmaster@@%d"}.
15474 @deftypevr {@code{dovecot-configuration} parameter} string hostname
15475 Hostname to use in various parts of sent mails (e.g. in Message-Id)
15476 and in LMTP replies. Default is the system's real hostname@@domain.
15477 Defaults to @samp{""}.
15480 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
15481 If user is over quota, return with temporary failure instead of
15483 Defaults to @samp{#f}.
15486 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
15487 Binary to use for sending mails.
15488 Defaults to @samp{"/usr/sbin/sendmail"}.
15491 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
15492 If non-empty, send mails via this SMTP host[:port] instead of
15494 Defaults to @samp{""}.
15497 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
15498 Subject: header to use for rejection mails. You can use the same
15499 variables as for @samp{rejection-reason} below.
15500 Defaults to @samp{"Rejected: %s"}.
15503 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
15504 Human readable error message for rejection mails. You can use
15517 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
15520 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
15521 Delimiter character between local-part and detail in email
15523 Defaults to @samp{"+"}.
15526 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
15527 Header where the original recipient address (SMTP's RCPT TO:
15528 address) is taken from if not available elsewhere. With dovecot-lda -a
15529 parameter overrides this. A commonly used header for this is
15531 Defaults to @samp{""}.
15534 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
15535 Should saving a mail to a nonexistent mailbox automatically create
15537 Defaults to @samp{#f}.
15540 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
15541 Should automatically created mailboxes be also automatically
15543 Defaults to @samp{#f}.
15546 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
15547 Maximum IMAP command line length. Some clients generate very long
15548 command lines with huge mailboxes, so you may need to raise this if you
15549 get "Too long argument" or "IMAP command line too large" errors
15551 Defaults to @samp{64000}.
15554 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
15555 IMAP logout format string:
15558 total number of bytes read from client
15560 total number of bytes sent to client.
15562 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
15563 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@}"}.
15566 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
15567 Override the IMAP CAPABILITY response. If the value begins with '+',
15568 add the given capabilities on top of the defaults (e.g. +XFOO XBAR).
15569 Defaults to @samp{""}.
15572 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
15573 How long to wait between "OK Still here" notifications when client
15575 Defaults to @samp{"2 mins"}.
15578 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
15579 ID field names and values to send to clients. Using * as the value
15580 makes Dovecot use the default value. The following fields have default
15581 values currently: name, version, os, os-version, support-url,
15583 Defaults to @samp{""}.
15586 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
15587 ID fields sent by client to log. * means everything.
15588 Defaults to @samp{""}.
15591 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
15592 Workarounds for various client bugs:
15595 @item delay-newmail
15596 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
15597 CHECK commands. Some clients ignore them otherwise, for example OSX
15598 Mail (<v2.1). Outlook Express breaks more badly though, without this it
15599 may show user "Message no longer in server" errors. Note that OE6
15600 still breaks even with this workaround if synchronization is set to
15603 @item tb-extra-mailbox-sep
15604 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
15605 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
15606 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
15608 @item tb-lsub-flags
15609 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g. mbox).
15610 This makes Thunderbird realize they aren't selectable and show them
15611 greyed out, instead of only later giving "not selectable" popup error.
15613 Defaults to @samp{()}.
15616 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
15617 Host allowed in URLAUTH URLs sent by client. "*" allows all.
15618 Defaults to @samp{""}.
15622 Whew! Lots of configuration options. The nice thing about it though is
15623 that GuixSD has a complete interface to Dovecot's configuration
15624 language. This allows not only a nice way to declare configurations,
15625 but also offers reflective capabilities as well: users can write code to
15626 inspect and transform configurations from within Scheme.
15628 However, it could be that you just want to get a @code{dovecot.conf} up
15629 and running. In that case, you can pass an
15630 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
15631 @code{dovecot-service}. As its name indicates, an opaque configuration
15632 does not have easy reflective capabilities.
15634 Available @code{opaque-dovecot-configuration} fields are:
15636 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
15637 The dovecot package.
15640 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
15641 The contents of the @code{dovecot.conf}, as a string.
15644 For example, if your @code{dovecot.conf} is just the empty string, you
15645 could instantiate a dovecot service like this:
15648 (dovecot-service #:config
15649 (opaque-dovecot-configuration
15653 @subsubheading OpenSMTPD Service
15655 @deffn {Scheme Variable} opensmtpd-service-type
15656 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
15657 service, whose value should be an @code{opensmtpd-configuration} object
15658 as in this example:
15661 (service opensmtpd-service-type
15662 (opensmtpd-configuration
15663 (config-file (local-file "./my-smtpd.conf"))))
15667 @deftp {Data Type} opensmtpd-configuration
15668 Data type representing the configuration of opensmtpd.
15671 @item @code{package} (default: @var{opensmtpd})
15672 Package object of the OpenSMTPD SMTP server.
15674 @item @code{config-file} (default: @var{%default-opensmtpd-file})
15675 File-like object of the OpenSMTPD configuration file to use. By default
15676 it listens on the loopback network interface, and allows for mail from
15677 users and daemons on the local machine, as well as permitting email to
15678 remote servers. Run @command{man smtpd.conf} for more information.
15683 @subsubheading Exim Service
15685 @cindex mail transfer agent (MTA)
15686 @cindex MTA (mail transfer agent)
15689 @deffn {Scheme Variable} exim-service-type
15690 This is the type of the @uref{https://exim.org, Exim} mail transfer
15691 agent (MTA), whose value should be an @code{exim-configuration} object
15692 as in this example:
15695 (service exim-service-type
15696 (exim-configuration
15697 (config-file (local-file "./my-exim.conf"))))
15701 In order to use an @code{exim-service-type} service you must also have a
15702 @code{mail-aliases-service-type} service present in your
15703 @code{operating-system} (even if it has no aliases).
15705 @deftp {Data Type} exim-configuration
15706 Data type representing the configuration of exim.
15709 @item @code{package} (default: @var{exim})
15710 Package object of the Exim server.
15712 @item @code{config-file} (default: @code{#f})
15713 File-like object of the Exim configuration file to use. If its value is
15714 @code{#f} then use the default configuration file from the package
15715 provided in @code{package}. The resulting configuration file is loaded
15716 after setting the @code{exim_user} and @code{exim_group} configuration
15722 @subsubheading Mail Aliases Service
15724 @cindex email aliases
15725 @cindex aliases, for email addresses
15727 @deffn {Scheme Variable} mail-aliases-service-type
15728 This is the type of the service which provides @code{/etc/aliases},
15729 specifying how to deliver mail to users on this system.
15732 (service mail-aliases-service-type
15733 '(("postmaster" "bob")
15734 ("bob" "bob@@example.com" "bob@@example2.com")))
15738 The configuration for a @code{mail-aliases-service-type} service is an
15739 association list denoting how to deliver mail that comes to this
15740 system. Each entry is of the form @code{(alias addresses ...)}, with
15741 @code{alias} specifying the local alias and @code{addresses} specifying
15742 where to deliver this user's mail.
15744 The aliases aren't required to exist as users on the local system. In
15745 the above example, there doesn't need to be a @code{postmaster} entry in
15746 the @code{operating-system}'s @code{user-accounts} in order to deliver
15747 the @code{postmaster} mail to @code{bob} (which subsequently would
15748 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
15750 @node Messaging Services
15751 @subsubsection Messaging Services
15756 The @code{(gnu services messaging)} module provides Guix service
15757 definitions for messaging services: currently only Prosody is supported.
15759 @subsubheading Prosody Service
15761 @deffn {Scheme Variable} prosody-service-type
15762 This is the type for the @uref{https://prosody.im, Prosody XMPP
15763 communication server}. Its value must be a @code{prosody-configuration}
15764 record as in this example:
15767 (service prosody-service-type
15768 (prosody-configuration
15769 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
15772 (int-component-configuration
15773 (hostname "conference.example.net")
15775 (mod-muc (mod-muc-configuration)))))
15778 (virtualhost-configuration
15779 (domain "example.net"))))))
15782 See below for details about @code{prosody-configuration}.
15786 By default, Prosody does not need much configuration. Only one
15787 @code{virtualhosts} field is needed: it specifies the domain you wish
15790 You can perform various sanity checks on the generated configuration
15791 with the @code{prosodyctl check} command.
15793 Prosodyctl will also help you to import certificates from the
15794 @code{letsencrypt} directory so that the @code{prosody} user can access
15795 them. See @url{https://prosody.im/doc/letsencrypt}.
15798 prosodyctl --root cert import /etc/letsencrypt/live
15801 The available configuration parameters follow. Each parameter
15802 definition is preceded by its type; for example, @samp{string-list foo}
15803 indicates that the @code{foo} parameter should be specified as a list of
15804 strings. Types starting with @code{maybe-} denote parameters that won't
15805 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
15807 There is also a way to specify the configuration as a string, if you
15808 have an old @code{prosody.cfg.lua} file that you want to port over from
15809 some other system; see the end for more details.
15811 The @code{file-object} type designates either a file-like object
15812 (@pxref{G-Expressions, file-like objects}) or a file name.
15814 @c The following documentation was initially generated by
15815 @c (generate-documentation) in (gnu services messaging). Manually maintained
15816 @c documentation is better, so we shouldn't hesitate to edit below as
15817 @c needed. However if the change you want to make to this documentation
15818 @c can be done in an automated way, it's probably easier to change
15819 @c (generate-documentation) than to make it below and have to deal with
15820 @c the churn as Prosody updates.
15822 Available @code{prosody-configuration} fields are:
15824 @deftypevr {@code{prosody-configuration} parameter} package prosody
15825 The Prosody package.
15828 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
15829 Location of the Prosody data storage directory. See
15830 @url{https://prosody.im/doc/configure}.
15831 Defaults to @samp{"/var/lib/prosody"}.
15834 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
15835 Additional plugin directories. They are searched in all the specified
15836 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
15837 Defaults to @samp{()}.
15840 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
15841 Every virtual host and component needs a certificate so that clients and
15842 servers can securely verify its identity. Prosody will automatically load
15843 certificates/keys from the directory specified here.
15844 Defaults to @samp{"/etc/prosody/certs"}.
15847 @deftypevr {@code{prosody-configuration} parameter} string-list admins
15848 This is a list of accounts that are admins for the server. Note that you
15849 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
15850 @url{https://prosody.im/doc/creating_accounts}.
15851 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
15852 Defaults to @samp{()}.
15855 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
15856 Enable use of libevent for better performance under high load. See
15857 @url{https://prosody.im/doc/libevent}.
15858 Defaults to @samp{#f}.
15861 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
15862 This is the list of modules Prosody will load on startup. It looks for
15863 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
15864 Documentation on modules can be found at:
15865 @url{https://prosody.im/doc/modules}.
15866 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
15869 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
15870 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
15871 should you want to disable them then add them to this list.
15872 Defaults to @samp{()}.
15875 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
15876 Path to a text file where the shared groups are defined. If this path is
15877 empty then @samp{mod_groups} does nothing. See
15878 @url{https://prosody.im/doc/modules/mod_groups}.
15879 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
15882 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
15883 Disable account creation by default, for security. See
15884 @url{https://prosody.im/doc/creating_accounts}.
15885 Defaults to @samp{#f}.
15888 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
15889 These are the SSL/TLS-related settings. Most of them are disabled so to
15890 use Prosody's defaults. If you do not completely understand these options, do
15891 not add them to your config, it is easy to lower the security of your server
15892 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
15894 Available @code{ssl-configuration} fields are:
15896 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
15897 This determines what handshake to use.
15900 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
15901 Path to your private key file.
15904 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
15905 Path to your certificate file.
15908 @deftypevr {@code{ssl-configuration} parameter} file-object capath
15909 Path to directory containing root certificates that you wish Prosody to
15910 trust when verifying the certificates of remote servers.
15911 Defaults to @samp{"/etc/ssl/certs"}.
15914 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
15915 Path to a file containing root certificates that you wish Prosody to trust.
15916 Similar to @code{capath} but with all certificates concatenated together.
15919 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
15920 A list of verification options (these mostly map to OpenSSL's
15921 @code{set_verify()} flags).
15924 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
15925 A list of general options relating to SSL/TLS. These map to OpenSSL's
15926 @code{set_options()}. For a full list of options available in LuaSec, see the
15930 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
15931 How long a chain of certificate authorities to check when looking for a
15932 trusted root certificate.
15935 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
15936 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
15937 clients, and in what order.
15940 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
15941 A path to a file containing parameters for Diffie-Hellman key exchange. You
15942 can create such a file with:
15943 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
15946 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
15947 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
15948 @samp{"secp384r1"}.
15951 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
15952 A list of "extra" verification options.
15955 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
15956 Password for encrypted private keys.
15961 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
15962 Whether to force all client-to-server connections to be encrypted or not.
15963 See @url{https://prosody.im/doc/modules/mod_tls}.
15964 Defaults to @samp{#f}.
15967 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
15968 Set of mechanisms that will never be offered. See
15969 @url{https://prosody.im/doc/modules/mod_saslauth}.
15970 Defaults to @samp{("DIGEST-MD5")}.
15973 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
15974 Whether to force all server-to-server connections to be encrypted or not.
15975 See @url{https://prosody.im/doc/modules/mod_tls}.
15976 Defaults to @samp{#f}.
15979 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
15980 Whether to require encryption and certificate authentication. This
15981 provides ideal security, but requires servers you communicate with to support
15982 encryption AND present valid, trusted certificates. See
15983 @url{https://prosody.im/doc/s2s#security}.
15984 Defaults to @samp{#f}.
15987 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
15988 Many servers don't support encryption or have invalid or self-signed
15989 certificates. You can list domains here that will not be required to
15990 authenticate using certificates. They will be authenticated using DNS. See
15991 @url{https://prosody.im/doc/s2s#security}.
15992 Defaults to @samp{()}.
15995 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
15996 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
15997 valid certificates for some domains by specifying a list here. See
15998 @url{https://prosody.im/doc/s2s#security}.
15999 Defaults to @samp{()}.
16002 @deftypevr {@code{prosody-configuration} parameter} string authentication
16003 Select the authentication backend to use. The default provider stores
16004 passwords in plaintext and uses Prosody's configured data storage to store the
16005 authentication data. If you do not trust your server please see
16006 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
16007 about using the hashed backend. See also
16008 @url{https://prosody.im/doc/authentication}
16009 Defaults to @samp{"internal_plain"}.
16012 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
16013 Set logging options. Advanced logging configuration is not yet supported
16014 by the GuixSD Prosody Service. See @url{https://prosody.im/doc/logging}.
16015 Defaults to @samp{"*syslog"}.
16018 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
16019 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
16020 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
16023 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
16024 Maximum allowed size of the HTTP body (in bytes).
16027 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
16028 Some modules expose their own URL in various ways. This URL is built
16029 from the protocol, host and port used. If Prosody sits behind a proxy, the
16030 public URL will be @code{http-external-url} instead. See
16031 @url{https://prosody.im/doc/http#external_url}.
16034 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
16035 A host in Prosody is a domain on which user accounts can be created. For
16036 example if you want your users to have addresses like
16037 @samp{"john.smith@@example.com"} then you need to add a host
16038 @samp{"example.com"}. All options in this list will apply only to this host.
16040 Note: the name "virtual" host is used in configuration to avoid confusion with
16041 the actual physical host that Prosody is installed on. A single Prosody
16042 instance can serve many domains, each one defined as a VirtualHost entry in
16043 Prosody's configuration. Conversely a server that hosts a single domain would
16044 have just one VirtualHost entry.
16046 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
16048 Available @code{virtualhost-configuration} fields are:
16050 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:
16051 @deftypevr {@code{virtualhost-configuration} parameter} string domain
16052 Domain you wish Prosody to serve.
16057 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
16058 Components are extra services on a server which are available to clients,
16059 usually on a subdomain of the main server (such as
16060 @samp{"mycomponent.example.com"}). Example components might be chatroom
16061 servers, user directories, or gateways to other protocols.
16063 Internal components are implemented with Prosody-specific plugins. To add an
16064 internal component, you simply fill the hostname field, and the plugin you wish
16065 to use for the component.
16067 See @url{https://prosody.im/doc/components}.
16068 Defaults to @samp{()}.
16070 Available @code{int-component-configuration} fields are:
16072 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:
16073 @deftypevr {@code{int-component-configuration} parameter} string hostname
16074 Hostname of the component.
16077 @deftypevr {@code{int-component-configuration} parameter} string plugin
16078 Plugin you wish to use for the component.
16081 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
16082 Multi-user chat (MUC) is Prosody's module for allowing you to create
16083 hosted chatrooms/conferences for XMPP users.
16085 General information on setting up and using multi-user chatrooms can be found
16086 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
16087 which you should read if you are new to XMPP chatrooms.
16089 See also @url{https://prosody.im/doc/modules/mod_muc}.
16091 Available @code{mod-muc-configuration} fields are:
16093 @deftypevr {@code{mod-muc-configuration} parameter} string name
16094 The name to return in service discovery responses.
16095 Defaults to @samp{"Prosody Chatrooms"}.
16098 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
16099 If @samp{#t}, this will only allow admins to create new chatrooms.
16100 Otherwise anyone can create a room. The value @samp{"local"} restricts room
16101 creation to users on the service's parent domain. E.g. @samp{user@@example.com}
16102 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
16103 restricts to service administrators only.
16104 Defaults to @samp{#f}.
16107 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
16108 Maximum number of history messages that will be sent to the member that has
16109 just joined the room.
16110 Defaults to @samp{20}.
16117 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
16118 External components use XEP-0114, which most standalone components
16119 support. To add an external component, you simply fill the hostname field. See
16120 @url{https://prosody.im/doc/components}.
16121 Defaults to @samp{()}.
16123 Available @code{ext-component-configuration} fields are:
16125 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:
16126 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
16127 Password which the component will use to log in.
16130 @deftypevr {@code{ext-component-configuration} parameter} string hostname
16131 Hostname of the component.
16136 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
16137 Port(s) Prosody listens on for component connections.
16138 Defaults to @samp{(5347)}.
16141 @deftypevr {@code{prosody-configuration} parameter} string component-interface
16142 Interface Prosody listens on for component connections.
16143 Defaults to @samp{"127.0.0.1"}.
16146 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
16147 Raw content that will be added to the configuration file.
16150 It could be that you just want to get a @code{prosody.cfg.lua}
16151 up and running. In that case, you can pass an
16152 @code{opaque-prosody-configuration} record as the value of
16153 @code{prosody-service-type}. As its name indicates, an opaque configuration
16154 does not have easy reflective capabilities.
16155 Available @code{opaque-prosody-configuration} fields are:
16157 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
16158 The prosody package.
16161 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
16162 The contents of the @code{prosody.cfg.lua} to use.
16165 For example, if your @code{prosody.cfg.lua} is just the empty
16166 string, you could instantiate a prosody service like this:
16169 (service prosody-service-type
16170 (opaque-prosody-configuration
16171 (prosody.cfg.lua "")))
16174 @c end of Prosody auto-generated documentation
16176 @subsubheading BitlBee Service
16178 @cindex IRC (Internet Relay Chat)
16179 @cindex IRC gateway
16180 @url{http://bitlbee.org,BitlBee} is a gateway that provides an IRC
16181 interface to a variety of messaging protocols such as XMPP.
16183 @defvr {Scheme Variable} bitlbee-service-type
16184 This is the service type for the @url{http://bitlbee.org,BitlBee} IRC
16185 gateway daemon. Its value is a @code{bitlbee-configuration} (see
16188 To have BitlBee listen on port 6667 on localhost, add this line to your
16192 (service bitlbee-service-type)
16196 @deftp {Data Type} bitlbee-configuration
16197 This is the configuration for BitlBee, with the following fields:
16200 @item @code{interface} (default: @code{"127.0.0.1"})
16201 @itemx @code{port} (default: @code{6667})
16202 Listen on the network interface corresponding to the IP address
16203 specified in @var{interface}, on @var{port}.
16205 When @var{interface} is @code{127.0.0.1}, only local clients can
16206 connect; when it is @code{0.0.0.0}, connections can come from any
16207 networking interface.
16209 @item @code{package} (default: @code{bitlbee})
16210 The BitlBee package to use.
16212 @item @code{plugins} (default: @code{'()})
16213 List of plugin packages to use---e.g., @code{bitlbee-discord}.
16215 @item @code{extra-settings} (default: @code{""})
16216 Configuration snippet added as-is to the BitlBee configuration file.
16221 @node Telephony Services
16222 @subsubsection Telephony Services
16224 @cindex Murmur (VoIP server)
16225 @cindex VoIP server
16226 This section describes how to set up and run a Murmur server. Murmur is
16227 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
16230 @deftp {Data Type} murmur-configuration
16231 The service type for the Murmur server. An example configuration can
16235 (service murmur-service-type
16236 (murmur-configuration
16238 "Welcome to this Mumble server running on GuixSD!")
16239 (cert-required? #t) ;disallow text password logins
16240 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
16241 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
16244 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
16245 password with the command that is printed during the activation phase.
16247 It is recommended to register a normal Mumble user account
16248 and grant it admin or moderator rights.
16249 You can use the @code{mumble} client to
16250 login as new normal user, register yourself, and log out.
16251 For the next step login with the name @code{SuperUser} use
16252 the @code{SuperUser} password that you set previously,
16253 and grant your newly registered mumble user administrator or moderator
16254 rights and create some channels.
16256 Available @code{murmur-configuration} fields are:
16259 @item @code{package} (default: @code{mumble})
16260 Package that contains @code{bin/murmurd}.
16262 @item @code{user} (default: @code{"murmur"})
16263 User who will run the Murmur server.
16265 @item @code{group} (default: @code{"murmur"})
16266 Group of the user who will run the murmur server.
16268 @item @code{port} (default: @code{64738})
16269 Port on which the server will listen.
16271 @item @code{welcome-text} (default: @code{""})
16272 Welcome text sent to clients when they connect.
16274 @item @code{server-password} (default: @code{""})
16275 Password the clients have to enter in order to connect.
16277 @item @code{max-users} (default: @code{100})
16278 Maximum of users that can be connected to the server at once.
16280 @item @code{max-user-bandwidth} (default: @code{#f})
16281 Maximum voice traffic a user can send per second.
16283 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
16284 File name of the sqlite database.
16285 The service's user will become the owner of the directory.
16287 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
16288 File name of the log file.
16289 The service's user will become the owner of the directory.
16291 @item @code{autoban-attempts} (default: @code{10})
16292 Maximum number of logins a user can make in @code{autoban-timeframe}
16293 without getting auto banned for @code{autoban-time}.
16295 @item @code{autoban-timeframe} (default: @code{120})
16296 Timeframe for autoban in seconds.
16298 @item @code{autoban-time} (default: @code{300})
16299 Amount of time in seconds for which a client gets banned
16300 when violating the autoban limits.
16302 @item @code{opus-threshold} (default: @code{100})
16303 Percentage of clients that need to support opus
16304 before switching over to opus audio codec.
16306 @item @code{channel-nesting-limit} (default: @code{10})
16307 How deep channels can be nested at maximum.
16309 @item @code{channelname-regex} (default: @code{#f})
16310 A string in form of a Qt regular expression that channel names must conform to.
16312 @item @code{username-regex} (default: @code{#f})
16313 A string in form of a Qt regular expression that user names must conform to.
16315 @item @code{text-message-length} (default: @code{5000})
16316 Maximum size in bytes that a user can send in one text chat message.
16318 @item @code{image-message-length} (default: @code{(* 128 1024)})
16319 Maximum size in bytes that a user can send in one image message.
16321 @item @code{cert-required?} (default: @code{#f})
16322 If it is set to @code{#t} clients that use weak password authentification
16323 will not be accepted. Users must have completed the certificate wizard to join.
16325 @item @code{remember-channel?} (default: @code{#f})
16326 Should murmur remember the last channel each user was in when they disconnected
16327 and put them into the remembered channel when they rejoin.
16329 @item @code{allow-html?} (default: @code{#f})
16330 Should html be allowed in text messages, user comments, and channel descriptions.
16332 @item @code{allow-ping?} (default: @code{#f})
16333 Setting to true exposes the current user count, the maximum user count, and
16334 the server's maximum bandwidth per client to unauthenticated users. In the
16335 Mumble client, this information is shown in the Connect dialog.
16337 Disabling this setting will prevent public listing of the server.
16339 @item @code{bonjour?} (default: @code{#f})
16340 Should the server advertise itself in the local network through the bonjour protocol.
16342 @item @code{send-version?} (default: @code{#f})
16343 Should the murmur server version be exposed in ping requests.
16345 @item @code{log-days} (default: @code{31})
16346 Murmur also stores logs in the database, which are accessible via RPC.
16347 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
16348 or -1 to disable logging to the database.
16350 @item @code{obfuscate-ips?} (default: @code{#t})
16351 Should logged ips be obfuscated to protect the privacy of users.
16353 @item @code{ssl-cert} (default: @code{#f})
16354 File name of the SSL/TLS certificate used for encrypted connections.
16357 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
16359 @item @code{ssl-key} (default: @code{#f})
16360 Filepath to the ssl private key used for encrypted connections.
16362 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
16365 @item @code{ssl-dh-params} (default: @code{#f})
16366 File name of a PEM-encoded file with Diffie-Hellman parameters
16367 for the SSL/TLS encryption. Alternatively you set it to
16368 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
16369 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
16371 @item @code{ssl-ciphers} (default: @code{#f})
16372 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
16375 This option is specified using
16376 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
16377 OpenSSL cipher list notation}.
16379 It is recommended that you try your cipher string using 'openssl ciphers <string>'
16380 before setting it here, to get a feel for which cipher suites you will get.
16381 After setting this option, it is recommend that you inspect your Murmur log
16382 to ensure that Murmur is using the cipher suites that you expected it to.
16384 Note: Changing this option may impact the backwards compatibility of your
16385 Murmur server, and can remove the ability for older Mumble clients to be able
16388 @item @code{public-registration} (default: @code{#f})
16389 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
16391 You can optionally register your server in the public server list that the
16392 @code{mumble} client shows on startup.
16393 You cannot register your server if you have set a @code{server-password},
16394 or set @code{allow-ping} to @code{#f}.
16396 It might take a few hours until it shows up in the public list.
16398 @item @code{file} (default: @code{#f})
16399 Optional alternative override for this configuration.
16403 @deftp {Data Type} murmur-public-registration-configuration
16404 Configuration for public registration of a murmur service.
16408 This is a display name for your server. Not to be confused with the hostname.
16410 @item @code{password}
16411 A password to identify your registration.
16412 Subsequent updates will need the same password. Don't lose your password.
16415 This should be a @code{http://} or @code{https://} link to your web
16418 @item @code{hostname} (default: @code{#f})
16419 By default your server will be listed by its IP address.
16420 If it is set your server will be linked by this host name instead.
16426 @node Monitoring Services
16427 @subsubsection Monitoring Services
16429 @subsubheading Tailon Service
16431 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
16432 viewing and searching log files.
16434 The following example will configure the service with default values.
16435 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
16438 (service tailon-service-type)
16441 The following example customises more of the Tailon configuration,
16442 adding @command{sed} to the list of allowed commands.
16445 (service tailon-service-type
16446 (tailon-configuration
16448 (tailon-configuration-file
16449 (allowed-commands '("tail" "grep" "awk" "sed"))))))
16453 @deftp {Data Type} tailon-configuration
16454 Data type representing the configuration of Tailon.
16455 This type has the following parameters:
16458 @item @code{config-file} (default: @code{(tailon-configuration-file)})
16459 The configuration file to use for Tailon. This can be set to a
16460 @dfn{tailon-configuration-file} record value, or any gexp
16461 (@pxref{G-Expressions}).
16463 For example, to instead use a local file, the @code{local-file} function
16467 (service tailon-service-type
16468 (tailon-configuration
16469 (config-file (local-file "./my-tailon.conf"))))
16472 @item @code{package} (default: @code{tailon})
16473 The tailon package to use.
16478 @deftp {Data Type} tailon-configuration-file
16479 Data type representing the configuration options for Tailon.
16480 This type has the following parameters:
16483 @item @code{files} (default: @code{(list "/var/log")})
16484 List of files to display. The list can include strings for a single file
16485 or directory, or a list, where the first item is the name of a
16486 subsection, and the remaining items are the files or directories in that
16489 @item @code{bind} (default: @code{"localhost:8080"})
16490 Address and port to which Tailon should bind on.
16492 @item @code{relative-root} (default: @code{#f})
16493 URL path to use for Tailon, set to @code{#f} to not use a path.
16495 @item @code{allow-transfers?} (default: @code{#t})
16496 Allow downloading the log files in the web interface.
16498 @item @code{follow-names?} (default: @code{#t})
16499 Allow tailing of not-yet existent files.
16501 @item @code{tail-lines} (default: @code{200})
16502 Number of lines to read initially from each file.
16504 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
16505 Commands to allow running. By default, @code{sed} is disabled.
16507 @item @code{debug?} (default: @code{#f})
16508 Set @code{debug?} to @code{#t} to show debug messages.
16510 @item @code{wrap-lines} (default: @code{#t})
16511 Initial line wrapping state in the web interface. Set to @code{#t} to
16512 initially wrap lines (the default), or to @code{#f} to initially not
16515 @item @code{http-auth} (default: @code{#f})
16516 HTTP authentication type to use. Set to @code{#f} to disable
16517 authentication (the default). Supported values are @code{"digest"} or
16520 @item @code{users} (default: @code{#f})
16521 If HTTP authentication is enabled (see @code{http-auth}), access will be
16522 restricted to the credentials provided here. To configure users, use a
16523 list of pairs, where the first element of the pair is the username, and
16524 the 2nd element of the pair is the password.
16527 (tailon-configuration-file
16528 (http-auth "basic")
16529 (users '(("user1" . "password1")
16530 ("user2" . "password2"))))
16537 @subsubheading Darkstat Service
16539 Darkstat is a packet sniffer that captures network traffic, calculates
16540 statistics about usage, and serves reports over HTTP.
16542 @defvar {Scheme Variable} darkstat-service-type
16543 This is the service type for the
16544 @uref{https://unix4lyfe.org/darkstat/, darkstat}
16545 service, its value must be a @code{darkstat-configuration} record as in
16549 (service darkstat-service-type
16550 (darkstat-configuration
16551 (interface "eno1")))
16555 @deftp {Data Type} darkstat-configuration
16556 Data type representing the configuration of @command{darkstat}.
16559 @item @code{package} (default: @code{darkstat})
16560 The darkstat package to use.
16562 @item @code{interface}
16563 Capture traffic on the specified network interface.
16565 @item @code{port} (default: @code{"667"})
16566 Bind the web interface to the specified port.
16568 @item @code{bind-address} (default: @code{"127.0.0.1"})
16569 Bind the web interface to the specified address.
16571 @item @code{base} (default: @code{"/"})
16572 Specify the path of the base URL. This can be useful if
16573 @command{darkstat} is accessed via a reverse proxy.
16578 @subsubheading Prometheus Node Exporter Service
16580 @cindex prometheus-node-exporter
16581 The Prometheus ``node exporter'' makes hardware and operating system statistics
16582 provided by the Linux kernel available for the Prometheus monitoring system.
16583 This service should be deployed on all physical nodes and virtual machines,
16584 where monitoring these statistics is desirable.
16586 @defvar {Scheme variable} prometheus-node-exporter-service-type
16587 This is the service type for the
16588 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
16589 service, its value must be a @code{prometheus-node-exporter-configuration}
16590 record as in this example:
16593 (service prometheus-node-exporter-service-type
16594 (prometheus-node-exporter-configuration
16595 (web-listen-address ":9100")))
16599 @deftp {Data Type} prometheus-node-exporter-configuration
16600 Data type representing the configuration of @command{node_exporter}.
16603 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
16604 The prometheus-node-exporter package to use.
16606 @item @code{web-listen-address} (default: @code{":9100"})
16607 Bind the web interface to the specified address.
16612 @node Kerberos Services
16613 @subsubsection Kerberos Services
16616 The @code{(gnu services kerberos)} module provides services relating to
16617 the authentication protocol @dfn{Kerberos}.
16619 @subsubheading Krb5 Service
16621 Programs using a Kerberos client library normally
16622 expect a configuration file in @file{/etc/krb5.conf}.
16623 This service generates such a file from a definition provided in the
16624 operating system declaration.
16625 It does not cause any daemon to be started.
16627 No ``keytab'' files are provided by this service---you must explicitly create them.
16628 This service is known to work with the MIT client library, @code{mit-krb5}.
16629 Other implementations have not been tested.
16631 @defvr {Scheme Variable} krb5-service-type
16632 A service type for Kerberos 5 clients.
16636 Here is an example of its use:
16638 (service krb5-service-type
16639 (krb5-configuration
16640 (default-realm "EXAMPLE.COM")
16641 (allow-weak-crypto? #t)
16644 (name "EXAMPLE.COM")
16645 (admin-server "groucho.example.com")
16646 (kdc "karl.example.com"))
16649 (admin-server "kerb-admin.argrx.edu")
16650 (kdc "keys.argrx.edu"))))))
16654 This example provides a Kerberos@tie{}5 client configuration which:
16656 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
16657 of which have distinct administration servers and key distribution centers;
16658 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
16659 specified by clients;
16660 @item Accepts services which only support encryption types known to be weak.
16663 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
16664 Only the most commonly used ones are described here.
16665 For a full list, and more detailed explanation of each, see the MIT
16666 @uref{http://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
16670 @deftp {Data Type} krb5-realm
16671 @cindex realm, kerberos
16674 This field is a string identifying the name of the realm.
16675 A common convention is to use the fully qualified DNS name of your organization,
16676 converted to upper case.
16678 @item @code{admin-server}
16679 This field is a string identifying the host where the administration server is
16683 This field is a string identifying the key distribution center
16688 @deftp {Data Type} krb5-configuration
16691 @item @code{allow-weak-crypto?} (default: @code{#f})
16692 If this flag is @code{#t} then services which only offer encryption algorithms
16693 known to be weak will be accepted.
16695 @item @code{default-realm} (default: @code{#f})
16696 This field should be a string identifying the default Kerberos
16697 realm for the client.
16698 You should set this field to the name of your Kerberos realm.
16699 If this value is @code{#f}
16700 then a realm must be specified with every Kerberos principal when invoking programs
16701 such as @command{kinit}.
16703 @item @code{realms}
16704 This should be a non-empty list of @code{krb5-realm} objects, which clients may
16706 Normally, one of them will have a @code{name} field matching the @code{default-realm}
16712 @subsubheading PAM krb5 Service
16715 The @code{pam-krb5} service allows for login authentication and password
16716 management via Kerberos.
16717 You will need this service if you want PAM enabled applications to authenticate
16718 users using Kerberos.
16720 @defvr {Scheme Variable} pam-krb5-service-type
16721 A service type for the Kerberos 5 PAM module.
16724 @deftp {Data Type} pam-krb5-configuration
16725 Data type representing the configuration of the Kerberos 5 PAM module
16726 This type has the following parameters:
16728 @item @code{pam-krb5} (default: @code{pam-krb5})
16729 The pam-krb5 package to use.
16731 @item @code{minimum-uid} (default: @code{1000})
16732 The smallest user ID for which Kerberos authentications should be attempted.
16733 Local accounts with lower values will silently fail to authenticate.
16739 @subsubsection Web Services
16744 The @code{(gnu services web)} module provides the Apache HTTP Server,
16745 the nginx web server, and also a fastcgi wrapper daemon.
16747 @subsubheading Apache HTTP Server
16749 @deffn {Scheme Variable} httpd-service-type
16750 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
16751 (@dfn{httpd}). The value for this service type is a
16752 @code{httpd-configuration} record.
16754 A simple example configuration is given below.
16757 (service httpd-service-type
16758 (httpd-configuration
16761 (server-name "www.example.com")
16762 (document-root "/srv/http/www.example.com")))))
16765 Other services can also extend the @code{httpd-service-type} to add to
16769 (simple-service 'my-extra-server httpd-service-type
16773 (list (string-append
16774 "ServerName "www.example.com
16775 DocumentRoot \"/srv/http/www.example.com\"")))))
16779 The details for the @code{httpd-configuration}, @code{httpd-module},
16780 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
16783 @deffn {Data Type} httpd-configuration
16784 This data type represents the configuration for the httpd service.
16787 @item @code{package} (default: @code{httpd})
16788 The httpd package to use.
16790 @item @code{pid-file} (default: @code{"/var/run/httpd"})
16791 The pid file used by the shepherd-service.
16793 @item @code{config} (default: @code{(httpd-config-file)})
16794 The configuration file to use with the httpd service. The default value
16795 is a @code{httpd-config-file} record, but this can also be a different
16796 G-expression that generates a file, for example a @code{plain-file}. A
16797 file outside of the store can also be specified through a string.
16802 @deffn {Data Type} httpd-module
16803 This data type represents a module for the httpd service.
16807 The name of the module.
16810 The file for the module. This can be relative to the httpd package being
16811 used, the absolute location of a file, or a G-expression for a file
16812 within the store, for example @code{(file-append mod-wsgi
16813 "/modules/mod_wsgi.so")}.
16818 @defvr {Scheme Variable} %default-httpd-modules
16819 A default list of @code{httpd-module} objects.
16822 @deffn {Data Type} httpd-config-file
16823 This data type represents a configuration file for the httpd service.
16826 @item @code{modules} (default: @code{%default-httpd-modules})
16827 The modules to load. Additional modules can be added here, or loaded by
16828 additional configuration.
16830 For example, in order to handle requests for PHP files, you can use Apache’s
16831 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
16834 (service httpd-service-type
16835 (httpd-configuration
16840 (name "proxy_module")
16841 (file "modules/mod_proxy.so"))
16843 (name "proxy_fcgi_module")
16844 (file "modules/mod_proxy_fcgi.so"))
16845 %default-httpd-modules))
16846 (extra-config (list "\
16847 <FilesMatch \\.php$>
16848 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
16849 </FilesMatch>"))))))
16850 (service php-fpm-service-type
16851 (php-fpm-configuration
16852 (socket "/var/run/php-fpm.sock")
16853 (socket-group "httpd")))
16856 @item @code{server-root} (default: @code{httpd})
16857 The @code{ServerRoot} in the configuration file, defaults to the httpd
16858 package. Directives including @code{Include} and @code{LoadModule} are
16859 taken as relative to the server root.
16861 @item @code{server-name} (default: @code{#f})
16862 The @code{ServerName} in the configuration file, used to specify the
16863 request scheme, hostname and port that the server uses to identify
16866 This doesn't need to be set in the server config, and can be specifyed
16867 in virtual hosts. The default is @code{#f} to not specify a
16870 @item @code{document-root} (default: @code{"/srv/http"})
16871 The @code{DocumentRoot} from which files will be served.
16873 @item @code{listen} (default: @code{'("80")})
16874 The list of values for the @code{Listen} directives in the config
16875 file. The value should be a list of strings, when each string can
16876 specify the port number to listen on, and optionally the IP address and
16879 @item @code{pid-file} (default: @code{"/var/run/httpd"})
16880 The @code{PidFile} to use. This should match the @code{pid-file} set in
16881 the @code{httpd-configuration} so that the Shepherd service is
16882 configured correctly.
16884 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
16885 The @code{ErrorLog} to which the server will log errors.
16887 @item @code{user} (default: @code{"httpd"})
16888 The @code{User} which the server will answer requests as.
16890 @item @code{group} (default: @code{"httpd"})
16891 The @code{Group} which the server will answer requests as.
16893 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
16894 A flat list of strings and G-expressions which will be added to the end
16895 of the configuration file.
16897 Any values which the service is extended with will be appended to this
16903 @deffn {Data Type} httpd-virtualhost
16904 This data type represents a virtualhost configuration block for the httpd service.
16906 These should be added to the extra-config for the httpd-service.
16909 (simple-service 'my-extra-server httpd-service-type
16913 (list (string-append
16914 "ServerName "www.example.com
16915 DocumentRoot \"/srv/http/www.example.com\"")))))
16919 @item @code{addresses-and-ports}
16920 The addresses and ports for the @code{VirtualHost} directive.
16922 @item @code{contents}
16923 The contents of the @code{VirtualHost} directive, this should be a list
16924 of strings and G-expressions.
16929 @subsubheading NGINX
16931 @deffn {Scheme Variable} nginx-service-type
16932 Service type for the @uref{https://nginx.org/,NGinx} web server. The
16933 value for this service type is a @code{<nginx-configuration>} record.
16935 A simple example configuration is given below.
16938 (service nginx-service-type
16939 (nginx-configuration
16941 (list (nginx-server-configuration
16942 (server-name '("www.example.com"))
16943 (root "/srv/http/www.example.com"))))))
16946 In addition to adding server blocks to the service configuration
16947 directly, this service can be extended by other services to add server
16948 blocks, as in this example:
16951 (simple-service 'my-extra-server nginx-service-type
16952 (list (nginx-server-configuration
16953 (root "/srv/http/extra-website")
16954 (try-files (list "$uri" "$uri/index.html")))))
16958 At startup, @command{nginx} has not yet read its configuration file, so
16959 it uses a default file to log error messages. If it fails to load its
16960 configuration file, that is where error messages are logged. After the
16961 configuration file is loaded, the default error log file changes as per
16962 configuration. In our case, startup error messages can be found in
16963 @file{/var/run/nginx/logs/error.log}, and after configuration in
16964 @file{/var/log/nginx/error.log}. The second location can be changed
16965 with the @var{log-directory} configuration option.
16967 @deffn {Data Type} nginx-configuration
16968 This data type represents the configuration for NGinx. Some
16969 configuration can be done through this and the other provided record
16970 types, or alternatively, a config file can be provided.
16973 @item @code{nginx} (default: @code{nginx})
16974 The nginx package to use.
16976 @item @code{log-directory} (default: @code{"/var/log/nginx"})
16977 The directory to which NGinx will write log files.
16979 @item @code{run-directory} (default: @code{"/var/run/nginx"})
16980 The directory in which NGinx will create a pid file, and write temporary
16983 @item @code{server-blocks} (default: @code{'()})
16984 A list of @dfn{server blocks} to create in the generated configuration
16985 file, the elements should be of type
16986 @code{<nginx-server-configuration>}.
16988 The following example would setup NGinx to serve @code{www.example.com}
16989 from the @code{/srv/http/www.example.com} directory, without using
16992 (service nginx-service-type
16993 (nginx-configuration
16995 (list (nginx-server-configuration
16996 (server-name '("www.example.com"))
16997 (root "/srv/http/www.example.com"))))))
17000 @item @code{upstream-blocks} (default: @code{'()})
17001 A list of @dfn{upstream blocks} to create in the generated configuration
17002 file, the elements should be of type
17003 @code{<nginx-upstream-configuration>}.
17005 Configuring upstreams through the @code{upstream-blocks} can be useful
17006 when combined with @code{locations} in the
17007 @code{<nginx-server-configuration>} records. The following example
17008 creates a server configuration with one location configuration, that
17009 will proxy requests to a upstream configuration, which will handle
17010 requests with two servers.
17015 (nginx-configuration
17017 (list (nginx-server-configuration
17018 (server-name '("www.example.com"))
17019 (root "/srv/http/www.example.com")
17022 (nginx-location-configuration
17024 (body '("proxy_pass http://server-proxy;"))))))))
17026 (list (nginx-upstream-configuration
17027 (name "server-proxy")
17028 (servers (list "server1.example.com"
17029 "server2.example.com")))))))
17032 @item @code{file} (default: @code{#f})
17033 If a configuration @var{file} is provided, this will be used, rather than
17034 generating a configuration file from the provided @code{log-directory},
17035 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
17036 proper operation, these arguments should match what is in @var{file} to ensure
17037 that the directories are created when the service is activated.
17039 This can be useful if you have an existing configuration file, or it's
17040 not possible to do what is required through the other parts of the
17041 nginx-configuration record.
17043 @item @code{server-names-hash-bucket-size} (default: @code{#f})
17044 Bucket size for the server names hash tables, defaults to @code{#f} to
17045 use the size of the processors cache line.
17047 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
17048 Maximum bucket size for the server names hash tables.
17050 @item @code{extra-content} (default: @code{""})
17051 Extra content for the @code{http} block. Should be string or a string
17052 valued G-expression.
17057 @deftp {Data Type} nginx-server-configuration
17058 Data type representing the configuration of an nginx server block.
17059 This type has the following parameters:
17062 @item @code{listen} (default: @code{'("80" "443 ssl")})
17063 Each @code{listen} directive sets the address and port for IP, or the
17064 path for a UNIX-domain socket on which the server will accept requests.
17065 Both address and port, or only address or only port can be specified.
17066 An address may also be a hostname, for example:
17069 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
17072 @item @code{server-name} (default: @code{(list 'default)})
17073 A list of server names this server represents. @code{'default} represents the
17074 default server for connections matching no other server.
17076 @item @code{root} (default: @code{"/srv/http"})
17077 Root of the website nginx will serve.
17079 @item @code{locations} (default: @code{'()})
17080 A list of @dfn{nginx-location-configuration} or
17081 @dfn{nginx-named-location-configuration} records to use within this
17084 @item @code{index} (default: @code{(list "index.html")})
17085 Index files to look for when clients ask for a directory. If it cannot be found,
17086 Nginx will send the list of files in the directory.
17088 @item @code{try-files} (default: @code{'()})
17089 A list of files whose existence is checked in the specified order.
17090 @code{nginx} will use the first file it finds to process the request.
17092 @item @code{ssl-certificate} (default: @code{#f})
17093 Where to find the certificate for secure connections. Set it to @code{#f} if
17094 you don't have a certificate or you don't want to use HTTPS.
17096 @item @code{ssl-certificate-key} (default: @code{#f})
17097 Where to find the private key for secure connections. Set it to @code{#f} if
17098 you don't have a key or you don't want to use HTTPS.
17100 @item @code{server-tokens?} (default: @code{#f})
17101 Whether the server should add its configuration to response.
17103 @item @code{raw-content} (default: @code{'()})
17104 A list of raw lines added to the server block.
17109 @deftp {Data Type} nginx-upstream-configuration
17110 Data type representing the configuration of an nginx @code{upstream}
17111 block. This type has the following parameters:
17115 Name for this group of servers.
17117 @item @code{servers}
17118 Specify the addresses of the servers in the group. The address can be
17119 specified as a IP address (e.g. @samp{127.0.0.1}), domain name
17120 (e.g. @samp{backend1.example.com}) or a path to a UNIX socket using the
17121 prefix @samp{unix:}. For addresses using an IP address or domain name,
17122 the default port is 80, and a different port can be specified
17128 @deftp {Data Type} nginx-location-configuration
17129 Data type representing the configuration of an nginx @code{location}
17130 block. This type has the following parameters:
17134 URI which this location block matches.
17136 @anchor{nginx-location-configuration body}
17138 Body of the location block, specified as a list of strings. This can contain
17140 configuration directives. For example, to pass requests to a upstream
17141 server group defined using an @code{nginx-upstream-configuration} block,
17142 the following directive would be specified in the body @samp{(list "proxy_pass
17143 http://upstream-name;")}.
17148 @deftp {Data Type} nginx-named-location-configuration
17149 Data type representing the configuration of an nginx named location
17150 block. Named location blocks are used for request redirection, and not
17151 used for regular request processing. This type has the following
17156 Name to identify this location block.
17159 @xref{nginx-location-configuration body}, as the body for named location
17160 blocks can be used in a similar way to the
17161 @code{nginx-location-configuration body}. One restriction is that the
17162 body of a named location block cannot contain location blocks.
17167 @subsubheading Varnish Cache
17169 Varnish is a fast cache server that sits in between web applications
17170 and end users. It proxies requests from clients and caches the
17171 accessed URLs such that multiple requests for the same resource only
17172 creates one request to the back-end.
17174 @defvr {Scheme Variable} varnish-service-type
17175 Service type for the Varnish daemon.
17178 @deftp {Data Type} varnish-configuration
17179 Data type representing the @code{varnish} service configuration.
17180 This type has the following parameters:
17183 @item @code{package} (default: @code{varnish})
17184 The Varnish package to use.
17186 @item @code{name} (default: @code{"default"})
17187 A name for this Varnish instance. Varnish will create a directory in
17188 @file{/var/varnish/} with this name and keep temporary files there. If
17189 the name starts with a forward slash, it is interpreted as an absolute
17192 Pass the @code{-n} argument to other Varnish programs to connect to the
17193 named instance, e.g. @command{varnishncsa -n default}.
17195 @item @code{backend} (default: @code{"localhost:8080"})
17196 The backend to use. This option has no effect if @code{vcl} is set.
17198 @item @code{vcl} (default: #f)
17199 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
17200 is @code{#f}, Varnish will proxy @code{backend} using the default
17201 configuration. Otherwise this must be a file-like object with valid
17204 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
17205 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
17206 can do something along these lines:
17209 (define %gnu-mirror
17213 backend gnu @{ .host = "www.gnu.org"; @}"))
17217 (services (cons (service varnish-service-type
17218 (varnish-configuration
17220 (vcl %gnu-mirror)))
17224 The configuration of an already running Varnish instance can be inspected
17225 and changed using the @command{varnishadm} program.
17227 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
17228 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
17229 comprehensive documentation on Varnish and its configuration language.
17231 @item @code{listen} (default: @code{'("localhost:80")})
17232 List of addresses Varnish will listen on.
17234 @item @code{storage} (default: @code{'("malloc,128m")})
17235 List of storage backends that will be available in VCL.
17237 @item @code{parameters} (default: @code{'()})
17238 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
17240 @item @code{extra-options} (default: @code{'()})
17241 Additional arguments to pass to the @command{varnishd} process.
17246 @subsubheading FastCGI
17249 FastCGI is an interface between the front-end and the back-end of a web
17250 service. It is a somewhat legacy facility; new web services should
17251 generally just talk HTTP between the front-end and the back-end.
17252 However there are a number of back-end services such as PHP or the
17253 optimized HTTP Git repository access that use FastCGI, so we have
17254 support for it in Guix.
17256 To use FastCGI, you configure the front-end web server (e.g., nginx) to
17257 dispatch some subset of its requests to the fastcgi backend, which
17258 listens on a local TCP or UNIX socket. There is an intermediary
17259 @code{fcgiwrap} program that sits between the actual backend process and
17260 the web server. The front-end indicates which backend program to run,
17261 passing that information to the @code{fcgiwrap} process.
17263 @defvr {Scheme Variable} fcgiwrap-service-type
17264 A service type for the @code{fcgiwrap} FastCGI proxy.
17267 @deftp {Data Type} fcgiwrap-configuration
17268 Data type representing the configuration of the @code{fcgiwrap} serice.
17269 This type has the following parameters:
17271 @item @code{package} (default: @code{fcgiwrap})
17272 The fcgiwrap package to use.
17274 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
17275 The socket on which the @code{fcgiwrap} process should listen, as a
17276 string. Valid @var{socket} values include
17277 @code{unix:@var{/path/to/unix/socket}},
17278 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
17279 @code{tcp6:[@var{ipv6_addr}]:port}.
17281 @item @code{user} (default: @code{fcgiwrap})
17282 @itemx @code{group} (default: @code{fcgiwrap})
17283 The user and group names, as strings, under which to run the
17284 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
17285 the user asks for the specific user or group names @code{fcgiwrap} that
17286 the corresponding user and/or group is present on the system.
17288 It is possible to configure a FastCGI-backed web service to pass HTTP
17289 authentication information from the front-end to the back-end, and to
17290 allow @code{fcgiwrap} to run the back-end process as a corresponding
17291 local user. To enable this capability on the back-end., run
17292 @code{fcgiwrap} as the @code{root} user and group. Note that this
17293 capability also has to be configured on the front-end as well.
17298 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
17299 with some additional features useful for sites of any size.
17301 These features include:
17303 @item Adaptive process spawning
17304 @item Basic statistics (similar to Apache's mod_status)
17305 @item Advanced process management with graceful stop/start
17306 @item Ability to start workers with different uid/gid/chroot/environment
17307 and different php.ini (replaces safe_mode)
17308 @item Stdout & stderr logging
17309 @item Emergency restart in case of accidental opcode cache destruction
17310 @item Accelerated upload support
17311 @item Support for a "slowlog"
17312 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
17313 a special function to finish request & flush all data while continuing to do
17314 something time-consuming (video converting, stats processing, etc.)
17318 @defvr {Scheme Variable} php-fpm-service-type
17319 A Service type for @code{php-fpm}.
17322 @deftp {Data Type} php-fpm-configuration
17323 Data Type for php-fpm service configuration.
17325 @item @code{php} (default: @code{php})
17326 The php package to use.
17327 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
17328 The address on which to accept FastCGI requests. Valid syntaxes are:
17330 @item @code{"ip.add.re.ss:port"}
17331 Listen on a TCP socket to a specific address on a specific port.
17332 @item @code{"port"}
17333 Listen on a TCP socket to all addresses on a specific port.
17334 @item @code{"/path/to/unix/socket"}
17335 Listen on a unix socket.
17338 @item @code{user} (default: @code{php-fpm})
17339 User who will own the php worker processes.
17340 @item @code{group} (default: @code{php-fpm})
17341 Group of the worker processes.
17342 @item @code{socket-user} (default: @code{php-fpm})
17343 User who can speak to the php-fpm socket.
17344 @item @code{socket-group} (default: @code{php-fpm})
17345 Group that can speak to the php-fpm socket.
17346 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
17347 The process id of the php-fpm process is written to this file
17348 once the service has started.
17349 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
17350 Log for the php-fpm master process.
17351 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
17352 Detailed settings for the php-fpm process manager.
17355 @item @code{<php-fpm-dynamic-process-manager-configuration>}
17356 @item @code{<php-fpm-static-process-manager-configuration>}
17357 @item @code{<php-fpm-on-demand-process-manager-configuration>}
17359 @item @code{display-errors} (default @code{#f})
17360 Determines whether php errors and warning should be sent to clients
17361 and displayed in their browsers.
17362 This is useful for local php development, but a security risk for public sites,
17363 as error messages can reveal passwords and personal data.
17364 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
17365 This file will log the @code{stderr} outputs of php worker processes.
17366 Can be set to @code{#f} to disable logging.
17367 @item @code{file} (default @code{#f})
17368 An optional override of the whole configuration.
17369 You can use the @code{mixed-text-file} function or an absolute filepath for it.
17373 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
17374 Data Type for the @code{dynamic} php-fpm process manager. With the
17375 @code{dynamic} process manager, spare worker processes are kept around
17376 based on it's configured limits.
17378 @item @code{max-children} (default: @code{5})
17379 Maximum of worker processes.
17380 @item @code{start-servers} (default: @code{2})
17381 How many worker processes should be started on start-up.
17382 @item @code{min-spare-servers} (default: @code{1})
17383 How many spare worker processes should be kept around at minimum.
17384 @item @code{max-spare-servers} (default: @code{3})
17385 How many spare worker processes should be kept around at maximum.
17389 @deftp {Data type} php-fpm-static-process-manager-configuration
17390 Data Type for the @code{static} php-fpm process manager. With the
17391 @code{static} process manager, an unchanging number of worker processes
17394 @item @code{max-children} (default: @code{5})
17395 Maximum of worker processes.
17399 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
17400 Data Type for the @code{on-demand} php-fpm process manager. With the
17401 @code{on-demand} process manager, worker processes are only created as
17404 @item @code{max-children} (default: @code{5})
17405 Maximum of worker processes.
17406 @item @code{process-idle-timeout} (default: @code{10})
17407 The time in seconds after which a process with no requests is killed.
17412 @deffn {Scheme Procedure} nginx-php-fpm-location @
17413 [#:nginx-package nginx] @
17414 [socket (string-append "/var/run/php" @
17415 (version-major (package-version php)) @
17417 A helper function to quickly add php to an @code{nginx-server-configuration}.
17420 A simple services setup for nginx with php can look like this:
17422 (services (cons* (service dhcp-client-service-type)
17423 (service php-fpm-service-type)
17424 (service nginx-service-type
17425 (nginx-server-configuration
17426 (server-name '("example.com"))
17427 (root "/srv/http/")
17429 (list (nginx-php-location)))
17431 (ssl-certificate #f)
17432 (ssl-certificate-key #f)))
17436 @cindex cat-avatar-generator
17437 The cat avatar generator is a simple service to demonstrate the use of php-fpm
17438 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
17439 the hash of a user's email address.
17441 @deffn {Scheme Procedure} cat-avatar-generator-serice @
17442 [#:cache-dir "/var/cache/cat-avatar-generator"] @
17443 [#:package cat-avatar-generator] @
17444 [#:configuration (nginx-server-configuration)]
17445 Returns an nginx-server-configuration that inherits @code{configuration}. It
17446 extends the nginx configuration to add a server block that serves @code{package},
17447 a version of cat-avatar-generator. During execution, cat-avatar-generator will
17448 be able to use @code{cache-dir} as its cache directory.
17451 A simple setup for cat-avatar-generator can look like this:
17453 (services (cons* (cat-avatar-generator-service
17455 (nginx-server-configuration
17456 (server-name '("example.com"))))
17461 @subsubheading Hpcguix-web
17463 @cindex hpcguix-web
17464 The @uref{hpcguix-web, https://github.com/UMCUGenetics/hpcguix-web/}
17465 program is a customizable web interface to browse Guix packages,
17466 initially designed for users of high-performance computing (HPC)
17469 @defvr {Scheme Variable} hpcguix-web-service-type
17470 The service type for @code{hpcguix-web}.
17473 @deftp {Data Type} hpcguix-web-configuration
17474 Data type for the hpcguix-web service configuration.
17478 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
17479 configuration. The main items available in this spec are:
17482 @item @code{title-prefix} (default: @code{"hpcguix | "})
17483 The page title prefix.
17485 @item @code{guix-command} (default: @code{"guix"})
17486 The @command{guix} command.
17488 @item @code{package-filter-proc} (default: @code{(const #t)})
17489 A procedure specifying how to filter packages that are displayed.
17491 @item @code{package-page-extension-proc} (default: @code{(const '())})
17492 Extension package for @code{hpcguix-web}.
17494 @item @code{menu} (default: @code{'()})
17495 Additional entry in page @code{menu}.
17497 @item @code{channels} (default: @code{%default-channels})
17498 List of channels from which the package list is built (@pxref{Channels}).
17500 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
17501 The expiration time, in seconds, after which the package list is rebuilt from
17502 the latest instances of the given channels.
17505 See the hpcguix-web repository for a
17506 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
17509 @item @code{package} (default: @code{hpcguix-web})
17510 The hpcguix-web package to use.
17514 A typical hpcguix-web service declaration looks like this:
17517 (service hpcguix-web-service-type
17518 (hpcguix-web-configuration
17520 #~(define site-config
17521 (hpcweb-configuration
17522 (title-prefix "Guix-HPC - ")
17523 (menu '(("/about" "ABOUT"))))))))
17527 The hpcguix-web service periodically updates the package list it publishes by
17528 pulling channels from Git. To that end, it needs to access X.509 certificates
17529 so that it can authenticate Git servers when communicating over HTTPS, and it
17530 assumes that @file{/etc/ssl/certs} contains those certificates.
17532 Thus, make sure to add @code{nss-certs} or another certificate package to the
17533 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
17534 more information on X.509 certificates.
17537 @node Certificate Services
17538 @subsubsection Certificate Services
17541 @cindex HTTP, HTTPS
17542 @cindex Let's Encrypt
17543 @cindex TLS certificates
17544 The @code{(gnu services certbot)} module provides a service to
17545 automatically obtain a valid TLS certificate from the Let's Encrypt
17546 certificate authority. These certificates can then be used to serve
17547 content securely over HTTPS or other TLS-based protocols, with the
17548 knowledge that the client will be able to verify the server's
17551 @url{https://letsencrypt.org/, Let's Encrypt} provides the
17552 @code{certbot} tool to automate the certification process. This tool
17553 first securely generates a key on the server. It then makes a request
17554 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
17555 checks that the request originates from the host in question by using a
17556 challenge-response protocol, requiring the server to provide its
17557 response over HTTP. If that protocol completes successfully, the CA
17558 signs the key, resulting in a certificate. That certificate is valid
17559 for a limited period of time, and therefore to continue to provide TLS
17560 services, the server needs to periodically ask the CA to renew its
17563 The certbot service automates this process: the initial key
17564 generation, the initial certification request to the Let's Encrypt
17565 service, the web server challenge/response integration, writing the
17566 certificate to disk, the automated periodic renewals, and the deployment
17567 tasks associated with the renewal (e.g. reloading services, copying keys
17568 with different permissions).
17570 Certbot is run twice a day, at a random minute within the hour. It
17571 won't do anything until your certificates are due for renewal or
17572 revoked, but running it regularly would give your service a chance of
17573 staying online in case a Let's Encrypt-initiated revocation happened for
17576 By using this service, you agree to the ACME Subscriber Agreement, which
17577 can be found there:
17578 @url{https://acme-v01.api.letsencrypt.org/directory}.
17580 @defvr {Scheme Variable} certbot-service-type
17581 A service type for the @code{certbot} Let's Encrypt client. Its value
17582 must be a @code{certbot-configuration} record as in this example:
17585 (define %nginx-deploy-hook
17587 "nginx-deploy-hook"
17588 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
17589 (kill pid SIGHUP))))
17591 (service certbot-service-type
17592 (certbot-configuration
17593 (email "foo@@example.net")
17596 (certificate-configuration
17597 (domains '("example.net" "www.example.net"))
17598 (deploy-hook %nginx-deploy-hook))
17599 (certificate-configuration
17600 (domains '("bar.example.net")))))))
17603 See below for details about @code{certbot-configuration}.
17606 @deftp {Data Type} certbot-configuration
17607 Data type representing the configuration of the @code{certbot} service.
17608 This type has the following parameters:
17611 @item @code{package} (default: @code{certbot})
17612 The certbot package to use.
17614 @item @code{webroot} (default: @code{/var/www})
17615 The directory from which to serve the Let's Encrypt challenge/response
17618 @item @code{certificates} (default: @code{()})
17619 A list of @code{certificates-configuration}s for which to generate
17620 certificates and request signatures. Each certificate has a @code{name}
17621 and several @code{domains}.
17624 Mandatory email used for registration, recovery contact, and important
17625 account notifications.
17627 @item @code{rsa-key-size} (default: @code{2048})
17628 Size of the RSA key.
17630 @item @code{default-location} (default: @i{see below})
17631 The default @code{nginx-location-configuration}. Because @code{certbot}
17632 needs to be able to serve challenges and responses, it needs to be able
17633 to run a web server. It does so by extending the @code{nginx} web
17634 service with an @code{nginx-server-configuration} listening on the
17635 @var{domains} on port 80, and which has a
17636 @code{nginx-location-configuration} for the @code{/.well-known/} URI
17637 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
17638 these nginx configuration data types.
17640 Requests to other URL paths will be matched by the
17641 @code{default-location}, which if present is added to all
17642 @code{nginx-server-configuration}s.
17644 By default, the @code{default-location} will issue a redirect from
17645 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
17646 you to define what to serve on your site via @code{https}.
17648 Pass @code{#f} to not issue a default location.
17652 @deftp {Data Type} certificate-configuration
17653 Data type representing the configuration of a certificate.
17654 This type has the following parameters:
17657 @item @code{name} (default: @i{see below})
17658 This name is used by Certbot for housekeeping and in file paths; it
17659 doesn't affect the content of the certificate itself. To see
17660 certificate names, run @code{certbot certificates}.
17662 Its default is the first provided domain.
17664 @item @code{domains} (default: @code{()})
17665 The first domain provided will be the subject CN of the certificate, and
17666 all domains will be Subject Alternative Names on the certificate.
17668 @item @code{deploy-hook} (default: @code{#f})
17669 Command to be run in a shell once for each successfully issued
17670 certificate. For this command, the shell variable
17671 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
17672 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
17673 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
17674 contain a space-delimited list of renewed certificate domains (for
17675 example, @samp{"example.com www.example.com"}.
17680 For each @code{certificate-configuration}, the certificate is saved to
17681 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
17682 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
17684 @subsubsection DNS Services
17685 @cindex DNS (domain name system)
17686 @cindex domain name system (DNS)
17688 The @code{(gnu services dns)} module provides services related to the
17689 @dfn{domain name system} (DNS). It provides a server service for hosting
17690 an @emph{authoritative} DNS server for multiple zones, slave or master.
17691 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
17692 caching and forwarding DNS server for the LAN, which uses
17693 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
17695 @subsubheading Knot Service
17697 An example configuration of an authoritative server for two zones, one master
17701 (define-zone-entries example.org.zone
17702 ;; Name TTL Class Type Data
17703 ("@@" "" "IN" "A" "127.0.0.1")
17704 ("@@" "" "IN" "NS" "ns")
17705 ("ns" "" "IN" "A" "127.0.0.1"))
17707 (define master-zone
17708 (knot-zone-configuration
17709 (domain "example.org")
17711 (origin "example.org")
17712 (entries example.org.zone)))))
17715 (knot-zone-configuration
17716 (domain "plop.org")
17717 (dnssec-policy "default")
17718 (master (list "plop-master"))))
17720 (define plop-master
17721 (knot-remote-configuration
17723 (address (list "208.76.58.171"))))
17727 (services (cons* (service knot-service-type
17728 (knot-configuration
17729 (remotes (list plop-master))
17730 (zones (list master-zone slave-zone))))
17735 @deffn {Scheme Variable} knot-service-type
17736 This is the type for the Knot DNS server.
17738 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
17739 zones, that is to say domain names you would buy from a registrar. This server
17740 is not a resolver, meaning that it can only resolve names for which it is
17741 authoritative. This server can be configured to serve zones as a master server
17742 or a slave server as a per-zone basis. Slave zones will get their data from
17743 masters, and will serve it as an authoritative server. From the point of view
17744 of a resolver, there is no difference between master and slave.
17746 The following data types are used to configure the Knot DNS server:
17749 @deftp {Data Type} knot-key-configuration
17750 Data type representing a key.
17751 This type has the following parameters:
17754 @item @code{id} (default: @code{""})
17755 An identifier for other configuration fields to refer to this key. IDs must
17756 be unique and must not be empty.
17758 @item @code{algorithm} (default: @code{#f})
17759 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
17760 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
17761 and @code{'hmac-sha512}.
17763 @item @code{secret} (default: @code{""})
17764 The secret key itself.
17769 @deftp {Data Type} knot-acl-configuration
17770 Data type representing an Access Control List (ACL) configuration.
17771 This type has the following parameters:
17774 @item @code{id} (default: @code{""})
17775 An identifier for ether configuration fields to refer to this key. IDs must be
17776 unique and must not be empty.
17778 @item @code{address} (default: @code{'()})
17779 An ordered list of IP addresses, network subnets, or network ranges represented
17780 with strings. The query must match one of them. Empty value means that
17781 address match is not required.
17783 @item @code{key} (default: @code{'()})
17784 An ordered list of references to keys represented with strings. The string
17785 must match a key ID defined in a @code{knot-key-configuration}. No key means
17786 that a key is not require to match that ACL.
17788 @item @code{action} (default: @code{'()})
17789 An ordered list of actions that are permitted or forbidden by this ACL. Possible
17790 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
17791 and @code{'update}.
17793 @item @code{deny?} (default: @code{#f})
17794 When true, the ACL defines restrictions. Listed actions are forbidden. When
17795 false, listed actions are allowed.
17800 @deftp {Data Type} zone-entry
17801 Data type represnting a record entry in a zone file.
17802 This type has the following parameters:
17805 @item @code{name} (default: @code{"@@"})
17806 The name of the record. @code{"@@"} refers to the origin of the zone. Names
17807 are relative to the origin of the zone. For example, in the @code{example.org}
17808 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
17809 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
17810 refers to @code{ns.example.org}.
17812 @item @code{ttl} (default: @code{""})
17813 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
17815 @item @code{class} (default: @code{"IN"})
17816 The class of the record. Knot currently supports only @code{"IN"} and
17817 partially @code{"CH"}.
17819 @item @code{type} (default: @code{"A"})
17820 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
17821 address), NS (Name Server) and MX (Mail eXchange). Many other types are
17824 @item @code{data} (default: @code{""})
17825 The data contained in the record. For instance an IP address associated with
17826 an A record, or a domain name associated with an NS record. Remember that
17827 domain names are relative to the origin unless they end with a dot.
17832 @deftp {Data Type} zone-file
17833 Data type representing the content of a zone file.
17834 This type has the following parameters:
17837 @item @code{entries} (default: @code{'()})
17838 The list of entries. The SOA record is taken care of, so you don't need to
17839 put it in the list of entries. This list should probably contain an entry
17840 for your primary authoritative DNS server. Other than using a list of entries
17841 directly, you can use @code{define-zone-entries} to define a object containing
17842 the list of entries more easily, that you can later pass to the @code{entries}
17843 field of the @code{zone-file}.
17845 @item @code{origin} (default: @code{""})
17846 The name of your zone. This parameter cannot be empty.
17848 @item @code{ns} (default: @code{"ns"})
17849 The domain of your primary authoritative DNS server. The name is relative to
17850 the origin, unless it ends with a dot. It is mandatory that this primary
17851 DNS server corresponds to an NS record in the zone and that it is associated
17852 to an IP address in the list of entries.
17854 @item @code{mail} (default: @code{"hostmaster"})
17855 An email address people can contact you at, as the owner of the zone. This
17856 is translated as @code{<mail>@@<origin>}.
17858 @item @code{serial} (default: @code{1})
17859 The serial number of the zone. As this is used to keep track of changes by
17860 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
17861 Always increment it when you make a change in your zone.
17863 @item @code{refresh} (default: @code{(* 2 24 3600)})
17864 The frequency at which slaves will do a zone transfer. This value is a number
17865 of seconds. It can be computed by multiplications or with
17866 @code{(string->duration)}.
17868 @item @code{retry} (default: @code{(* 15 60)})
17869 The period after which a slave will retry to contact its master when it fails
17870 to do so a first time.
17872 @item @code{expiry} (default: @code{(* 14 24 3600)})
17873 Default TTL of records. Existing records are considered correct for at most
17874 this amount of time. After this period, resolvers will invalidate their cache
17875 and check again that it still exists.
17877 @item @code{nx} (default: @code{3600})
17878 Default TTL of inexistant records. This delay is usually short because you want
17879 your new domains to reach everyone quickly.
17884 @deftp {Data Type} knot-remote-configuration
17885 Data type representing a remote configuration.
17886 This type has the following parameters:
17889 @item @code{id} (default: @code{""})
17890 An identifier for other configuration fields to refer to this remote. IDs must
17891 be unique and must not be empty.
17893 @item @code{address} (default: @code{'()})
17894 An ordered list of destination IP addresses. Addresses are tried in sequence.
17895 An optional port can be given with the @@ separator. For instance:
17896 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
17898 @item @code{via} (default: @code{'()})
17899 An ordered list of source IP addresses. An empty list will have Knot choose
17900 an appropriate source IP. An optional port can be given with the @@ separator.
17901 The default is to choose at random.
17903 @item @code{key} (default: @code{#f})
17904 A reference to a key, that is a string containing the identifier of a key
17905 defined in a @code{knot-key-configuration} field.
17910 @deftp {Data Type} knot-keystore-configuration
17911 Data type representing a keystore to hold dnssec keys.
17912 This type has the following parameters:
17915 @item @code{id} (default: @code{""})
17916 The id of the keystore. It must not be empty.
17918 @item @code{backend} (default: @code{'pem})
17919 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
17921 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
17922 The configuration string of the backend. An example for the PKCS#11 is:
17923 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
17924 For the pem backend, the string reprensents a path in the file system.
17929 @deftp {Data Type} knot-policy-configuration
17930 Data type representing a dnssec policy. Knot DNS is able to automatically
17931 sign your zones. It can either generate and manage your keys automatically or
17932 use keys that you generate.
17934 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
17935 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
17936 zone. In order to be trusted, the KSK needs to be present in the parent zone
17937 (usually a top-level domain). If your registrar supports dnssec, you will
17938 have to send them your KSK's hash so they can add a DS record in their zone.
17939 This is not automated and need to be done each time you change your KSK.
17941 The policy also defines the lifetime of keys. Usually, ZSK can be changed
17942 easily and use weaker cryptographic functions (they use lower parameters) in
17943 order to sign records quickly, so they are changed often. The KSK however
17944 requires manual interaction with the registrar, so they are changed less often
17945 and use stronger parameters because they sign only one record.
17947 This type has the following parameters:
17950 @item @code{id} (default: @code{""})
17951 The id of the policy. It must not be empty.
17953 @item @code{keystore} (default: @code{"default"})
17954 A reference to a keystore, that is a string containing the identifier of a
17955 keystore defined in a @code{knot-keystore-configuration} field. The
17956 @code{"default"} identifier means the default keystore (a kasp database that
17957 was setup by this service).
17959 @item @code{manual?} (default: @code{#f})
17960 Whether the key management is manual or automatic.
17962 @item @code{single-type-signing?} (default: @code{#f})
17963 When @code{#t}, use the Single-Type Signing Scheme.
17965 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
17966 An algorithm of signing keys and issued signatures.
17968 @item @code{ksk-size} (default: @code{256})
17969 The length of the KSK. Note that this value is correct for the default
17970 algorithm, but would be unsecure for other algorithms.
17972 @item @code{zsk-size} (default: @code{256})
17973 The length of the ZSK. Note that this value is correct for the default
17974 algorithm, but would be unsecure for other algorithms.
17976 @item @code{dnskey-ttl} (default: @code{'default})
17977 The TTL value for DNSKEY records added into zone apex. The special
17978 @code{'default} value means same as the zone SOA TTL.
17980 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
17981 The period between ZSK publication and the next rollover initiation.
17983 @item @code{propagation-delay} (default: @code{(* 24 3600)})
17984 An extra delay added for each key rollover step. This value should be high
17985 enough to cover propagation of data from the master server to all slaves.
17987 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
17988 A validity period of newly issued signatures.
17990 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
17991 A period how long before a signature expiration the signature will be refreshed.
17993 @item @code{nsec3?} (default: @code{#f})
17994 When @code{#t}, NSEC3 will be used instead of NSEC.
17996 @item @code{nsec3-iterations} (default: @code{5})
17997 The number of additional times the hashing is performed.
17999 @item @code{nsec3-salt-length} (default: @code{8})
18000 The length of a salt field in octets, which is appended to the original owner
18001 name before hashing.
18003 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
18004 The validity period of newly issued salt field.
18009 @deftp {Data Type} knot-zone-configuration
18010 Data type representing a zone served by Knot.
18011 This type has the following parameters:
18014 @item @code{domain} (default: @code{""})
18015 The domain served by this configuration. It must not be empty.
18017 @item @code{file} (default: @code{""})
18018 The file where this zone is saved. This parameter is ignored by master zones.
18019 Empty means default location that depends on the domain name.
18021 @item @code{zone} (default: @code{(zone-file)})
18022 The content of the zone file. This parameter is ignored by slave zones. It
18023 must contain a zone-file record.
18025 @item @code{master} (default: @code{'()})
18026 A list of master remotes. When empty, this zone is a master. When set, this
18027 zone is a slave. This is a list of remotes identifiers.
18029 @item @code{ddns-master} (default: @code{#f})
18030 The main master. When empty, it defaults to the first master in the list of
18033 @item @code{notify} (default: @code{'()})
18034 A list of slave remote identifiers.
18036 @item @code{acl} (default: @code{'()})
18037 A list of acl identifiers.
18039 @item @code{semantic-checks?} (default: @code{#f})
18040 When set, this adds more semantic checks to the zone.
18042 @item @code{disable-any?} (default: @code{#f})
18043 When set, this forbids queries of the ANY type.
18045 @item @code{zonefile-sync} (default: @code{0})
18046 The delay between a modification in memory and on disk. 0 means immediate
18049 @item @code{serial-policy} (default: @code{'increment})
18050 A policy between @code{'increment} and @code{'unixtime}.
18055 @deftp {Data Type} knot-configuration
18056 Data type representing the Knot configuration.
18057 This type has the following parameters:
18060 @item @code{knot} (default: @code{knot})
18063 @item @code{run-directory} (default: @code{"/var/run/knot"})
18064 The run directory. This directory will be used for pid file and sockets.
18066 @item @code{listen-v4} (default: @code{"0.0.0.0"})
18067 An ip address on which to listen.
18069 @item @code{listen-v6} (default: @code{"::"})
18070 An ip address on which to listen.
18072 @item @code{listen-port} (default: @code{53})
18073 A port on which to listen.
18075 @item @code{keys} (default: @code{'()})
18076 The list of knot-key-configuration used by this configuration.
18078 @item @code{acls} (default: @code{'()})
18079 The list of knot-acl-configuration used by this configuration.
18081 @item @code{remotes} (default: @code{'()})
18082 The list of knot-remote-configuration used by this configuration.
18084 @item @code{zones} (default: @code{'()})
18085 The list of knot-zone-configuration used by this configuration.
18090 @subsubheading Dnsmasq Service
18092 @deffn {Scheme Variable} dnsmasq-service-type
18093 This is the type of the dnsmasq service, whose value should be an
18094 @code{dnsmasq-configuration} object as in this example:
18097 (service dnsmasq-service-type
18098 (dnsmasq-configuration
18100 (servers '("192.168.1.1"))))
18104 @deftp {Data Type} dnsmasq-configuration
18105 Data type representing the configuration of dnsmasq.
18108 @item @code{package} (default: @var{dnsmasq})
18109 Package object of the dnsmasq server.
18111 @item @code{no-hosts?} (default: @code{#f})
18112 When true, don't read the hostnames in /etc/hosts.
18114 @item @code{port} (default: @code{53})
18115 The port to listen on. Setting this to zero completely disables DNS
18116 responses, leaving only DHCP and/or TFTP functions.
18118 @item @code{local-service?} (default: @code{#t})
18119 Accept DNS queries only from hosts whose address is on a local subnet,
18120 ie a subnet for which an interface exists on the server.
18122 @item @code{listen-addresses} (default: @code{'()})
18123 Listen on the given IP addresses.
18125 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
18126 The file to read the IP address of the upstream nameservers from.
18128 @item @code{no-resolv?} (default: @code{#f})
18129 When true, don't read @var{resolv-file}.
18131 @item @code{servers} (default: @code{'()})
18132 Specify IP address of upstream servers directly.
18134 @item @code{cache-size} (default: @code{150})
18135 Set the size of dnsmasq's cache. Setting the cache size to zero
18138 @item @code{negative-cache?} (default: @code{#t})
18139 When false, disable negative caching.
18144 @subsubheading ddclient Service
18147 The ddclient service described below runs the ddclient daemon, which takes
18148 care of automatically updating DNS entries for service providers such as
18149 @uref{https://dyn.com/dns/, Dyn}.
18151 The following example show instantiates the service with its default
18155 (service ddclient-service-type)
18158 Note that ddclient needs to access credentials that are stored in a
18159 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
18160 @code{secret-file} below.) You are expected to create this file manually, in
18161 an ``out-of-band'' fashion (you @emph{could} make this file part of the
18162 service configuration, for instance by using @code{plain-file}, but it will be
18163 world-readable @i{via} @file{/gnu/store}.) See the examples in the
18164 @file{share/ddclient} directory of the @code{ddclient} package.
18166 @c %start of fragment
18168 Available @code{ddclient-configuration} fields are:
18170 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
18171 The ddclient package.
18175 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
18176 The period after which ddclient will retry to check IP and domain name.
18178 Defaults to @samp{300}.
18182 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
18183 Use syslog for the output.
18185 Defaults to @samp{#t}.
18189 @deftypevr {@code{ddclient-configuration} parameter} string mail
18192 Defaults to @samp{"root"}.
18196 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
18197 Mail failed update to user.
18199 Defaults to @samp{"root"}.
18203 @deftypevr {@code{ddclient-configuration} parameter} string pid
18204 The ddclient PID file.
18206 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
18210 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
18211 Enable SSL support.
18213 Defaults to @samp{#t}.
18217 @deftypevr {@code{ddclient-configuration} parameter} string user
18218 Specifies the user name or ID that is used when running ddclient
18221 Defaults to @samp{"ddclient"}.
18225 @deftypevr {@code{ddclient-configuration} parameter} string group
18226 Group of the user who will run the ddclient program.
18228 Defaults to @samp{"ddclient"}.
18232 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
18233 Secret file which will be appended to @file{ddclient.conf} file. This
18234 file contains credentials for use by ddclient. You are expected to
18235 create it manually.
18237 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
18241 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
18242 Extra options will be appended to @file{ddclient.conf} file.
18244 Defaults to @samp{()}.
18249 @c %end of fragment
18253 @subsubsection VPN Services
18254 @cindex VPN (virtual private network)
18255 @cindex virtual private network (VPN)
18257 The @code{(gnu services vpn)} module provides services related to
18258 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
18259 your machine to connect to a VPN, and a @emph{servire} service for your machine
18260 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
18262 @deffn {Scheme Procedure} openvpn-client-service @
18263 [#:config (openvpn-client-configuration)]
18265 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
18268 @deffn {Scheme Procedure} openvpn-server-service @
18269 [#:config (openvpn-server-configuration)]
18271 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
18273 Both can be run simultaneously.
18276 @c %automatically generated documentation
18278 Available @code{openvpn-client-configuration} fields are:
18280 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
18281 The OpenVPN package.
18285 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
18286 The OpenVPN pid file.
18288 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
18292 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
18293 The protocol (UDP or TCP) used to open a channel between clients and
18296 Defaults to @samp{udp}.
18300 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
18301 The device type used to represent the VPN connection.
18303 Defaults to @samp{tun}.
18307 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
18308 The certificate authority to check connections against.
18310 Defaults to @samp{"/etc/openvpn/ca.crt"}.
18314 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
18315 The certificate of the machine the daemon is running on. It should be
18316 signed by the authority given in @code{ca}.
18318 Defaults to @samp{"/etc/openvpn/client.crt"}.
18322 @deftypevr {@code{openvpn-client-configuration} parameter} string key
18323 The key of the machine the daemon is running on. It must be the key whose
18324 certificate is @code{cert}.
18326 Defaults to @samp{"/etc/openvpn/client.key"}.
18330 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
18331 Whether to use the lzo compression algorithm.
18333 Defaults to @samp{#t}.
18337 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
18338 Don't re-read key files across SIGUSR1 or --ping-restart.
18340 Defaults to @samp{#t}.
18344 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
18345 Don't close and reopen TUN/TAP device or run up/down scripts across
18346 SIGUSR1 or --ping-restart restarts.
18348 Defaults to @samp{#t}.
18352 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
18355 Defaults to @samp{3}.
18359 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
18360 Add an additional layer of HMAC authentication on top of the TLS control
18361 channel to protect against DoS attacks.
18363 Defaults to @samp{#f}.
18367 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
18368 Whether to check the server certificate has server usage extension.
18370 Defaults to @samp{#t}.
18374 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
18375 Bind to a specific local port number.
18377 Defaults to @samp{#f}.
18381 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
18382 Retry resolving server address.
18384 Defaults to @samp{#t}.
18388 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
18389 A list of remote servers to connect to.
18391 Defaults to @samp{()}.
18393 Available @code{openvpn-remote-configuration} fields are:
18395 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
18398 Defaults to @samp{"my-server"}.
18402 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
18403 Port number the server listens to.
18405 Defaults to @samp{1194}.
18410 @c %end of automatic openvpn-client documentation
18412 @c %automatically generated documentation
18414 Available @code{openvpn-server-configuration} fields are:
18416 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
18417 The OpenVPN package.
18421 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
18422 The OpenVPN pid file.
18424 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
18428 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
18429 The protocol (UDP or TCP) used to open a channel between clients and
18432 Defaults to @samp{udp}.
18436 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
18437 The device type used to represent the VPN connection.
18439 Defaults to @samp{tun}.
18443 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
18444 The certificate authority to check connections against.
18446 Defaults to @samp{"/etc/openvpn/ca.crt"}.
18450 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
18451 The certificate of the machine the daemon is running on. It should be
18452 signed by the authority given in @code{ca}.
18454 Defaults to @samp{"/etc/openvpn/client.crt"}.
18458 @deftypevr {@code{openvpn-server-configuration} parameter} string key
18459 The key of the machine the daemon is running on. It must be the key whose
18460 certificate is @code{cert}.
18462 Defaults to @samp{"/etc/openvpn/client.key"}.
18466 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
18467 Whether to use the lzo compression algorithm.
18469 Defaults to @samp{#t}.
18473 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
18474 Don't re-read key files across SIGUSR1 or --ping-restart.
18476 Defaults to @samp{#t}.
18480 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
18481 Don't close and reopen TUN/TAP device or run up/down scripts across
18482 SIGUSR1 or --ping-restart restarts.
18484 Defaults to @samp{#t}.
18488 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
18491 Defaults to @samp{3}.
18495 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
18496 Add an additional layer of HMAC authentication on top of the TLS control
18497 channel to protect against DoS attacks.
18499 Defaults to @samp{#f}.
18503 @deftypevr {@code{openvpn-server-configuration} parameter} number port
18504 Specifies the port number on which the server listens.
18506 Defaults to @samp{1194}.
18510 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
18511 An ip and mask specifying the subnet inside the virtual network.
18513 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
18517 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
18518 A CIDR notation specifying the IPv6 subnet inside the virtual network.
18520 Defaults to @samp{#f}.
18524 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
18525 The Diffie-Hellman parameters file.
18527 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
18531 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
18532 The file that records client IPs.
18534 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
18538 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
18539 When true, the server will act as a gateway for its clients.
18541 Defaults to @samp{#f}.
18545 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
18546 When true, clients are allowed to talk to each other inside the VPN.
18548 Defaults to @samp{#f}.
18552 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
18553 Causes ping-like messages to be sent back and forth over the link so
18554 that each side knows when the other side has gone down. @code{keepalive}
18555 requires a pair. The first element is the period of the ping sending,
18556 and the second element is the timeout before considering the other side
18561 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
18562 The maximum number of clients.
18564 Defaults to @samp{100}.
18568 @deftypevr {@code{openvpn-server-configuration} parameter} string status
18569 The status file. This file shows a small report on current connection.
18570 It is truncated and rewritten every minute.
18572 Defaults to @samp{"/var/run/openvpn/status"}.
18576 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
18577 The list of configuration for some clients.
18579 Defaults to @samp{()}.
18581 Available @code{openvpn-ccd-configuration} fields are:
18583 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
18586 Defaults to @samp{"client"}.
18590 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
18593 Defaults to @samp{#f}.
18597 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
18600 Defaults to @samp{#f}.
18607 @c %end of automatic openvpn-server documentation
18610 @node Network File System
18611 @subsubsection Network File System
18614 The @code{(gnu services nfs)} module provides the following services,
18615 which are most commonly used in relation to mounting or exporting
18616 directory trees as @dfn{network file systems} (NFS).
18618 @subsubheading RPC Bind Service
18621 The RPC Bind service provides a facility to map program numbers into
18622 universal addresses.
18623 Many NFS related services use this facility. Hence it is automatically
18624 started when a dependent service starts.
18626 @defvr {Scheme Variable} rpcbind-service-type
18627 A service type for the RPC portmapper daemon.
18631 @deftp {Data Type} rpcbind-configuration
18632 Data type representing the configuration of the RPC Bind Service.
18633 This type has the following parameters:
18635 @item @code{rpcbind} (default: @code{rpcbind})
18636 The rpcbind package to use.
18638 @item @code{warm-start?} (default: @code{#t})
18639 If this parameter is @code{#t}, then the daemon will read a
18640 state file on startup thus reloading state information saved by a previous
18646 @subsubheading Pipefs Pseudo File System
18650 The pipefs file system is used to transfer NFS related data
18651 between the kernel and user space programs.
18653 @defvr {Scheme Variable} pipefs-service-type
18654 A service type for the pipefs pseudo file system.
18657 @deftp {Data Type} pipefs-configuration
18658 Data type representing the configuration of the pipefs pseudo file system service.
18659 This type has the following parameters:
18661 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
18662 The directory to which the file system is to be attached.
18667 @subsubheading GSS Daemon Service
18670 @cindex global security system
18672 The @dfn{global security system} (GSS) daemon provides strong security for RPC
18674 Before exchanging RPC requests an RPC client must establish a security
18675 context. Typically this is done using the Kerberos command @command{kinit}
18676 or automatically at login time using PAM services (@pxref{Kerberos Services}).
18678 @defvr {Scheme Variable} gss-service-type
18679 A service type for the Global Security System (GSS) daemon.
18682 @deftp {Data Type} gss-configuration
18683 Data type representing the configuration of the GSS daemon service.
18684 This type has the following parameters:
18686 @item @code{nfs-utils} (default: @code{nfs-utils})
18687 The package in which the @command{rpc.gssd} command is to be found.
18689 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
18690 The directory where the pipefs file system is mounted.
18696 @subsubheading IDMAP Daemon Service
18698 @cindex name mapper
18700 The idmap daemon service provides mapping between user IDs and user names.
18701 Typically it is required in order to access file systems mounted via NFSv4.
18703 @defvr {Scheme Variable} idmap-service-type
18704 A service type for the Identity Mapper (IDMAP) daemon.
18707 @deftp {Data Type} idmap-configuration
18708 Data type representing the configuration of the IDMAP daemon service.
18709 This type has the following parameters:
18711 @item @code{nfs-utils} (default: @code{nfs-utils})
18712 The package in which the @command{rpc.idmapd} command is to be found.
18714 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
18715 The directory where the pipefs file system is mounted.
18717 @item @code{domain} (default: @code{#f})
18718 The local NFSv4 domain name.
18719 This must be a string or @code{#f}.
18720 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
18725 @node Continuous Integration
18726 @subsubsection Continuous Integration
18728 @cindex continuous integration
18729 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
18730 continuous integration tool for Guix. It can be used both for development and
18731 for providing substitutes to others (@pxref{Substitutes}).
18733 The @code{(gnu services cuirass)} module provides the following service.
18735 @defvr {Scheme Procedure} cuirass-service-type
18736 The type of the Cuirass service. Its value must be a
18737 @code{cuirass-configuration} object, as described below.
18740 To add build jobs, you have to set the @code{specifications} field of the
18741 configuration. Here is an example of a service that polls the Guix repository
18742 and builds the packages from a manifest. Some of the packages are defined in
18743 the @code{"custom-packages"} input, which is the equivalent of
18744 @code{GUIX_PACKAGE_PATH}.
18747 (define %cuirass-specs
18749 '((#:name . "my-manifest")
18750 (#:load-path-inputs . ("guix"))
18751 (#:package-path-inputs . ("custom-packages"))
18752 (#:proc-input . "guix")
18753 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
18754 (#:proc . cuirass-jobs)
18755 (#:proc-args . ((subset . "manifests")
18756 (systems . ("x86_64-linux"))
18757 (manifests . (("config" . "guix/manifest.scm")))))
18758 (#:inputs . (((#:name . "guix")
18759 (#:url . "git://git.savannah.gnu.org/guix.git")
18760 (#:load-path . ".")
18761 (#:branch . "master")
18762 (#:no-compile? . #t))
18763 ((#:name . "config")
18764 (#:url . "git://git.example.org/config.git")
18765 (#:load-path . ".")
18766 (#:branch . "master")
18767 (#:no-compile? . #t))
18768 ((#:name . "custom-packages")
18769 (#:url . "git://git.example.org/custom-packages.git")
18770 (#:load-path . ".")
18771 (#:branch . "master")
18772 (#:no-compile? . #t)))))))
18774 (service cuirass-service-type
18775 (cuirass-configuration
18776 (specifications %cuirass-specs)))
18779 While information related to build jobs is located directly in the
18780 specifications, global settings for the @command{cuirass} process are
18781 accessible in other @code{cuirass-configuration} fields.
18783 @deftp {Data Type} cuirass-configuration
18784 Data type representing the configuration of Cuirass.
18787 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
18788 Location of the log file.
18790 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
18791 Location of the repository cache.
18793 @item @code{user} (default: @code{"cuirass"})
18794 Owner of the @code{cuirass} process.
18796 @item @code{group} (default: @code{"cuirass"})
18797 Owner's group of the @code{cuirass} process.
18799 @item @code{interval} (default: @code{60})
18800 Number of seconds between the poll of the repositories followed by the
18803 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
18804 Location of sqlite database which contains the build results and previously
18805 added specifications.
18807 @item @code{ttl} (default: @code{(* 30 24 3600)})
18808 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
18809 are registered for build results. This means that build results are protected
18810 from garbage collection for at least @var{ttl} seconds.
18812 @item @code{port} (default: @code{8081})
18813 Port number used by the HTTP server.
18815 @item --listen=@var{host}
18816 Listen on the network interface for @var{host}. The default is to
18817 accept connections from localhost.
18819 @item @code{specifications} (default: @code{#~'()})
18820 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
18821 where a specification is an association list
18822 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
18823 keys are keywords (@code{#:keyword-example}) as shown in the example
18826 @item @code{use-substitutes?} (default: @code{#f})
18827 This allows using substitutes to avoid building every dependencies of a job
18830 @item @code{one-shot?} (default: @code{#f})
18831 Only evaluate specifications and build derivations once.
18833 @item @code{fallback?} (default: @code{#f})
18834 When substituting a pre-built binary fails, fall back to building
18837 @item @code{cuirass} (default: @code{cuirass})
18838 The Cuirass package to use.
18842 @node Power Management Services
18843 @subsubsection Power Management Services
18846 @cindex power management with TLP
18847 @subsubheading TLP daemon
18849 The @code{(gnu services pm)} module provides a Guix service definition
18850 for the Linux power management tool TLP.
18852 TLP enables various powersaving modes in userspace and kernel.
18853 Contrary to @code{upower-service}, it is not a passive,
18854 monitoring tool, as it will apply custom settings each time a new power
18855 source is detected. More information can be found at
18856 @uref{http://linrunner.de/en/tlp/tlp.html, TLP home page}.
18858 @deffn {Scheme Variable} tlp-service-type
18859 The service type for the TLP tool. Its value should be a valid
18860 TLP configuration (see below). To use the default settings, simply
18863 (service tlp-service-type)
18867 By default TLP does not need much configuration but most TLP parameters
18868 can be tweaked using @code{tlp-configuration}.
18870 Each parameter definition is preceded by its type; for example,
18871 @samp{boolean foo} indicates that the @code{foo} parameter
18872 should be specified as a boolean. Types starting with
18873 @code{maybe-} denote parameters that won't show up in TLP config file
18874 when their value is @code{'disabled}.
18876 @c The following documentation was initially generated by
18877 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
18878 @c documentation is better, so we shouldn't hesitate to edit below as
18879 @c needed. However if the change you want to make to this documentation
18880 @c can be done in an automated way, it's probably easier to change
18881 @c (generate-documentation) than to make it below and have to deal with
18882 @c the churn as TLP updates.
18884 Available @code{tlp-configuration} fields are:
18886 @deftypevr {@code{tlp-configuration} parameter} package tlp
18891 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
18892 Set to true if you wish to enable TLP.
18894 Defaults to @samp{#t}.
18898 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
18899 Default mode when no power supply can be detected. Alternatives are AC
18902 Defaults to @samp{"AC"}.
18906 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
18907 Number of seconds Linux kernel has to wait after the disk goes idle,
18908 before syncing on AC.
18910 Defaults to @samp{0}.
18914 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
18915 Same as @code{disk-idle-ac} but on BAT mode.
18917 Defaults to @samp{2}.
18921 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
18922 Dirty pages flushing periodicity, expressed in seconds.
18924 Defaults to @samp{15}.
18928 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
18929 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
18931 Defaults to @samp{60}.
18935 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
18936 CPU frequency scaling governor on AC mode. With intel_pstate driver,
18937 alternatives are powersave and performance. With acpi-cpufreq driver,
18938 alternatives are ondemand, powersave, performance and conservative.
18940 Defaults to @samp{disabled}.
18944 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
18945 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
18947 Defaults to @samp{disabled}.
18951 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
18952 Set the min available frequency for the scaling governor on AC.
18954 Defaults to @samp{disabled}.
18958 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
18959 Set the max available frequency for the scaling governor on AC.
18961 Defaults to @samp{disabled}.
18965 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
18966 Set the min available frequency for the scaling governor on BAT.
18968 Defaults to @samp{disabled}.
18972 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
18973 Set the max available frequency for the scaling governor on BAT.
18975 Defaults to @samp{disabled}.
18979 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
18980 Limit the min P-state to control the power dissipation of the CPU, in AC
18981 mode. Values are stated as a percentage of the available performance.
18983 Defaults to @samp{disabled}.
18987 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
18988 Limit the max P-state to control the power dissipation of the CPU, in AC
18989 mode. Values are stated as a percentage of the available performance.
18991 Defaults to @samp{disabled}.
18995 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
18996 Same as @code{cpu-min-perf-on-ac} on BAT mode.
18998 Defaults to @samp{disabled}.
19002 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
19003 Same as @code{cpu-max-perf-on-ac} on BAT mode.
19005 Defaults to @samp{disabled}.
19009 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
19010 Enable CPU turbo boost feature on AC mode.
19012 Defaults to @samp{disabled}.
19016 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
19017 Same as @code{cpu-boost-on-ac?} on BAT mode.
19019 Defaults to @samp{disabled}.
19023 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
19024 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
19025 used under light load conditions.
19027 Defaults to @samp{#f}.
19031 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
19032 Same as @code{sched-powersave-on-ac?} but on BAT mode.
19034 Defaults to @samp{#t}.
19038 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
19039 Enable Linux kernel NMI watchdog.
19041 Defaults to @samp{#f}.
19045 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
19046 For Linux kernels with PHC patch applied, change CPU voltages. An
19047 example value would be @samp{"F:V F:V F:V F:V"}.
19049 Defaults to @samp{disabled}.
19053 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
19054 Set CPU performance versus energy saving policy on AC. Alternatives are
19055 performance, normal, powersave.
19057 Defaults to @samp{"performance"}.
19061 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
19062 Same as @code{energy-perf-policy-ac} but on BAT mode.
19064 Defaults to @samp{"powersave"}.
19068 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
19073 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
19074 Hard disk advanced power management level.
19078 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
19079 Same as @code{disk-apm-bat} but on BAT mode.
19083 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
19084 Hard disk spin down timeout. One value has to be specified for each
19085 declared hard disk.
19087 Defaults to @samp{disabled}.
19091 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
19092 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
19094 Defaults to @samp{disabled}.
19098 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
19099 Select IO scheduler for disk devices. One value has to be specified for
19100 each declared hard disk. Example alternatives are cfq, deadline and
19103 Defaults to @samp{disabled}.
19107 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
19108 SATA aggressive link power management (ALPM) level. Alternatives are
19109 min_power, medium_power, max_performance.
19111 Defaults to @samp{"max_performance"}.
19115 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
19116 Same as @code{sata-linkpwr-ac} but on BAT mode.
19118 Defaults to @samp{"min_power"}.
19122 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
19123 Exclude specified SATA host devices for link power management.
19125 Defaults to @samp{disabled}.
19129 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
19130 Enable Runtime Power Management for AHCI controller and disks on AC
19133 Defaults to @samp{disabled}.
19137 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
19138 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
19140 Defaults to @samp{disabled}.
19144 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
19145 Seconds of inactivity before disk is suspended.
19147 Defaults to @samp{15}.
19151 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
19152 PCI Express Active State Power Management level. Alternatives are
19153 default, performance, powersave.
19155 Defaults to @samp{"performance"}.
19159 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
19160 Same as @code{pcie-aspm-ac} but on BAT mode.
19162 Defaults to @samp{"powersave"}.
19166 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
19167 Radeon graphics clock speed level. Alternatives are low, mid, high,
19170 Defaults to @samp{"high"}.
19174 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
19175 Same as @code{radeon-power-ac} but on BAT mode.
19177 Defaults to @samp{"low"}.
19181 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
19182 Radeon dynamic power management method (DPM). Alternatives are battery,
19185 Defaults to @samp{"performance"}.
19189 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
19190 Same as @code{radeon-dpm-state-ac} but on BAT mode.
19192 Defaults to @samp{"battery"}.
19196 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
19197 Radeon DPM performance level. Alternatives are auto, low, high.
19199 Defaults to @samp{"auto"}.
19203 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
19204 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
19206 Defaults to @samp{"auto"}.
19210 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
19211 Wifi power saving mode.
19213 Defaults to @samp{#f}.
19217 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
19218 Same as @code{wifi-power-ac?} but on BAT mode.
19220 Defaults to @samp{#t}.
19224 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
19225 Disable wake on LAN.
19227 Defaults to @samp{#t}.
19231 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
19232 Timeout duration in seconds before activating audio power saving on
19233 Intel HDA and AC97 devices. A value of 0 disables power saving.
19235 Defaults to @samp{0}.
19239 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
19240 Same as @code{sound-powersave-ac} but on BAT mode.
19242 Defaults to @samp{1}.
19246 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
19247 Disable controller in powersaving mode on Intel HDA devices.
19249 Defaults to @samp{#t}.
19253 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
19254 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
19255 powered on again by releasing (and reinserting) the eject lever or by
19256 pressing the disc eject button on newer models.
19258 Defaults to @samp{#f}.
19262 @deftypevr {@code{tlp-configuration} parameter} string bay-device
19263 Name of the optical drive device to power off.
19265 Defaults to @samp{"sr0"}.
19269 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
19270 Runtime Power Management for PCI(e) bus devices. Alternatives are on
19273 Defaults to @samp{"on"}.
19277 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
19278 Same as @code{runtime-pm-ac} but on BAT mode.
19280 Defaults to @samp{"auto"}.
19284 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
19285 Runtime Power Management for all PCI(e) bus devices, except blacklisted
19288 Defaults to @samp{#t}.
19292 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
19293 Exclude specified PCI(e) device addresses from Runtime Power Management.
19295 Defaults to @samp{disabled}.
19299 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
19300 Exclude PCI(e) devices assigned to the specified drivers from Runtime
19305 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
19306 Enable USB autosuspend feature.
19308 Defaults to @samp{#t}.
19312 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
19313 Exclude specified devices from USB autosuspend.
19315 Defaults to @samp{disabled}.
19319 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
19320 Exclude WWAN devices from USB autosuspend.
19322 Defaults to @samp{#t}.
19326 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
19327 Include specified devices into USB autosuspend, even if they are already
19328 excluded by the driver or via @code{usb-blacklist-wwan?}.
19330 Defaults to @samp{disabled}.
19334 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
19335 Enable USB autosuspend before shutdown.
19337 Defaults to @samp{disabled}.
19341 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
19342 Restore radio device state (bluetooth, wifi, wwan) from previous
19343 shutdown on system startup.
19345 Defaults to @samp{#f}.
19350 @cindex CPU frequency scaling with thermald
19351 @subsubheading Thermald daemon
19353 The @code{(gnu services pm)} module provides an interface to
19354 thermald, a CPU frequency scaling service which helps prevent overheating.
19356 @defvr {Scheme Variable} thermald-service-type
19357 This is the service type for
19358 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
19359 Thermal Daemon, which is responsible for controlling the thermal state
19360 of processors and preventing overheating.
19363 @deftp {Data Type} thermald-configuration
19364 Data type representing the configuration of @code{thermald-service-type}.
19367 @item @code{ignore-cpuid-check?} (default: @code{#f})
19368 Ignore cpuid check for supported CPU models.
19370 @item @code{thermald} (default: @var{thermald})
19371 Package object of thermald.
19376 @node Audio Services
19377 @subsubsection Audio Services
19379 The @code{(gnu services audio)} module provides a service to start MPD
19380 (the Music Player Daemon).
19383 @subsubheading Music Player Daemon
19385 The Music Player Daemon (MPD) is a service that can play music while
19386 being controlled from the local machine or over the network by a variety
19389 The following example shows how one might run @code{mpd} as user
19390 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
19393 (service mpd-service-type
19399 @defvr {Scheme Variable} mpd-service-type
19400 The service type for @command{mpd}
19403 @deftp {Data Type} mpd-configuration
19404 Data type representing the configuration of @command{mpd}.
19407 @item @code{user} (default: @code{"mpd"})
19408 The user to run mpd as.
19410 @item @code{music-dir} (default: @code{"~/Music"})
19411 The directory to scan for music files.
19413 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
19414 The directory to store playlists.
19416 @item @code{port} (default: @code{"6600"})
19417 The port to run mpd on.
19419 @item @code{address} (default: @code{"any"})
19420 The address that mpd will bind to. To use a Unix domain socket,
19421 an absolute path can be specified here.
19426 @node Virtualization Services
19427 @subsubsection Virtualization services
19429 The @code{(gnu services virtualization)} module provides services for
19430 the libvirt and virtlog daemons, as well as other virtualization-related
19433 @subsubheading Libvirt daemon
19434 @code{libvirtd} is the server side daemon component of the libvirt
19435 virtualization management system. This daemon runs on host servers
19436 and performs required management tasks for virtualized guests.
19438 @deffn {Scheme Variable} libvirt-service-type
19439 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
19440 Its value must be a @code{libvirt-configuration}.
19443 (service libvirt-service-type
19444 (libvirt-configuration
19445 (unix-sock-group "libvirt")
19446 (tls-port "16555")))
19450 @c Auto-generated with (generate-libvirt-documentation)
19451 Available @code{libvirt-configuration} fields are:
19453 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
19458 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
19459 Flag listening for secure TLS connections on the public TCP/IP port.
19460 must set @code{listen} for this to have any effect.
19462 It is necessary to setup a CA and issue server certificates before using
19465 Defaults to @samp{#t}.
19469 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
19470 Listen for unencrypted TCP connections on the public TCP/IP port. must
19471 set @code{listen} for this to have any effect.
19473 Using the TCP socket requires SASL authentication by default. Only SASL
19474 mechanisms which support data encryption are allowed. This is
19475 DIGEST_MD5 and GSSAPI (Kerberos5)
19477 Defaults to @samp{#f}.
19481 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
19482 Port for accepting secure TLS connections This can be a port number, or
19485 Defaults to @samp{"16514"}.
19489 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
19490 Port for accepting insecure TCP connections This can be a port number,
19493 Defaults to @samp{"16509"}.
19497 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
19498 IP address or hostname used for client connections.
19500 Defaults to @samp{"0.0.0.0"}.
19504 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
19505 Flag toggling mDNS advertisement of the libvirt service.
19507 Alternatively can disable for all services on a host by stopping the
19510 Defaults to @samp{#f}.
19514 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
19515 Default mDNS advertisement name. This must be unique on the immediate
19518 Defaults to @samp{"Virtualization Host <hostname>"}.
19522 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
19523 UNIX domain socket group ownership. This can be used to allow a
19524 'trusted' set of users access to management capabilities without
19527 Defaults to @samp{"root"}.
19531 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
19532 UNIX socket permissions for the R/O socket. This is used for monitoring
19535 Defaults to @samp{"0777"}.
19539 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
19540 UNIX socket permissions for the R/W socket. Default allows only root.
19541 If PolicyKit is enabled on the socket, the default will change to allow
19542 everyone (eg, 0777)
19544 Defaults to @samp{"0770"}.
19548 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
19549 UNIX socket permissions for the admin socket. Default allows only owner
19550 (root), do not change it unless you are sure to whom you are exposing
19553 Defaults to @samp{"0777"}.
19557 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
19558 The directory in which sockets will be found/created.
19560 Defaults to @samp{"/var/run/libvirt"}.
19564 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
19565 Authentication scheme for UNIX read-only sockets. By default socket
19566 permissions allow anyone to connect
19568 Defaults to @samp{"polkit"}.
19572 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
19573 Authentication scheme for UNIX read-write sockets. By default socket
19574 permissions only allow root. If PolicyKit support was compiled into
19575 libvirt, the default will be to use 'polkit' auth.
19577 Defaults to @samp{"polkit"}.
19581 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
19582 Authentication scheme for TCP sockets. If you don't enable SASL, then
19583 all TCP traffic is cleartext. Don't do this outside of a dev/test
19586 Defaults to @samp{"sasl"}.
19590 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
19591 Authentication scheme for TLS sockets. TLS sockets already have
19592 encryption provided by the TLS layer, and limited authentication is done
19595 It is possible to make use of any SASL authentication mechanism as well,
19596 by using 'sasl' for this option
19598 Defaults to @samp{"none"}.
19602 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
19603 API access control scheme.
19605 By default an authenticated user is allowed access to all APIs. Access
19606 drivers can place restrictions on this.
19608 Defaults to @samp{()}.
19612 @deftypevr {@code{libvirt-configuration} parameter} string key-file
19613 Server key file path. If set to an empty string, then no private key is
19616 Defaults to @samp{""}.
19620 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
19621 Server key file path. If set to an empty string, then no certificate is
19624 Defaults to @samp{""}.
19628 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
19629 Server key file path. If set to an empty string, then no CA certificate
19632 Defaults to @samp{""}.
19636 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
19637 Certificate revocation list path. If set to an empty string, then no
19640 Defaults to @samp{""}.
19644 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
19645 Disable verification of our own server certificates.
19647 When libvirtd starts it performs some sanity checks against its own
19650 Defaults to @samp{#f}.
19654 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
19655 Disable verification of client certificates.
19657 Client certificate verification is the primary authentication mechanism.
19658 Any client which does not present a certificate signed by the CA will be
19661 Defaults to @samp{#f}.
19665 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
19666 Whitelist of allowed x509 Distinguished Name.
19668 Defaults to @samp{()}.
19672 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
19673 Whitelist of allowed SASL usernames. The format for username depends on
19674 the SASL authentication mechanism.
19676 Defaults to @samp{()}.
19680 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
19681 Override the compile time default TLS priority string. The default is
19682 usually "NORMAL" unless overridden at build time. Only set this is it
19683 is desired for libvirt to deviate from the global default settings.
19685 Defaults to @samp{"NORMAL"}.
19689 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
19690 Maximum number of concurrent client connections to allow over all
19693 Defaults to @samp{5000}.
19697 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
19698 Maximum length of queue of connections waiting to be accepted by the
19699 daemon. Note, that some protocols supporting retransmission may obey
19700 this so that a later reattempt at connection succeeds.
19702 Defaults to @samp{1000}.
19706 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
19707 Maximum length of queue of accepted but not yet authenticated clients.
19708 Set this to zero to turn this feature off
19710 Defaults to @samp{20}.
19714 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
19715 Number of workers to start up initially.
19717 Defaults to @samp{5}.
19721 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
19722 Maximum number of worker threads.
19724 If the number of active clients exceeds @code{min-workers}, then more
19725 threads are spawned, up to max_workers limit. Typically you'd want
19726 max_workers to equal maximum number of clients allowed.
19728 Defaults to @samp{20}.
19732 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
19733 Number of priority workers. If all workers from above pool are stuck,
19734 some calls marked as high priority (notably domainDestroy) can be
19735 executed in this pool.
19737 Defaults to @samp{5}.
19741 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
19742 Total global limit on concurrent RPC calls.
19744 Defaults to @samp{20}.
19748 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
19749 Limit on concurrent requests from a single client connection. To avoid
19750 one client monopolizing the server this should be a small fraction of
19751 the global max_requests and max_workers parameter.
19753 Defaults to @samp{5}.
19757 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
19758 Same as @code{min-workers} but for the admin interface.
19760 Defaults to @samp{1}.
19764 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
19765 Same as @code{max-workers} but for the admin interface.
19767 Defaults to @samp{5}.
19771 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
19772 Same as @code{max-clients} but for the admin interface.
19774 Defaults to @samp{5}.
19778 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
19779 Same as @code{max-queued-clients} but for the admin interface.
19781 Defaults to @samp{5}.
19785 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
19786 Same as @code{max-client-requests} but for the admin interface.
19788 Defaults to @samp{5}.
19792 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
19793 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
19795 Defaults to @samp{3}.
19799 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
19802 A filter allows to select a different logging level for a given category
19803 of logs The format for a filter is one of:
19814 where @code{name} is a string which is matched against the category
19815 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
19816 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
19817 be a substring of the full category name, in order to match multiple
19818 similar categories), the optional "+" prefix tells libvirt to log stack
19819 trace for each message matching name, and @code{x} is the minimal level
19820 where matching messages should be logged:
19837 Multiple filters can be defined in a single filters statement, they just
19838 need to be separated by spaces.
19840 Defaults to @samp{"3:remote 4:event"}.
19844 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
19847 An output is one of the places to save logging information The format
19848 for an output can be:
19852 output goes to stderr
19854 @item x:syslog:name
19855 use syslog for the output and use the given name as the ident
19857 @item x:file:file_path
19858 output to a file, with the given filepath
19861 output to journald logging system
19865 In all case the x prefix is the minimal level, acting as a filter
19882 Multiple outputs can be defined, they just need to be separated by
19885 Defaults to @samp{"3:stderr"}.
19889 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
19890 Allows usage of the auditing subsystem to be altered
19894 0: disable all auditing
19897 1: enable auditing, only if enabled on host
19900 2: enable auditing, and exit if disabled on host.
19904 Defaults to @samp{1}.
19908 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
19909 Send audit messages via libvirt logging infrastructure.
19911 Defaults to @samp{#f}.
19915 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
19916 Host UUID. UUID must not have all digits be the same.
19918 Defaults to @samp{""}.
19922 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
19923 Source to read host UUID.
19927 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
19930 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
19934 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
19937 Defaults to @samp{"smbios"}.
19941 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
19942 A keepalive message is sent to a client after @code{keepalive_interval}
19943 seconds of inactivity to check if the client is still responding. If
19944 set to -1, libvirtd will never send keepalive requests; however clients
19945 can still send them and the daemon will send responses.
19947 Defaults to @samp{5}.
19951 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
19952 Maximum number of keepalive messages that are allowed to be sent to the
19953 client without getting any response before the connection is considered
19956 In other words, the connection is automatically closed approximately
19957 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
19958 the last message received from the client. When @code{keepalive-count}
19959 is set to 0, connections will be automatically closed after
19960 @code{keepalive-interval} seconds of inactivity without sending any
19961 keepalive messages.
19963 Defaults to @samp{5}.
19967 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
19968 Same as above but for admin interface.
19970 Defaults to @samp{5}.
19974 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
19975 Same as above but for admin interface.
19977 Defaults to @samp{5}.
19981 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
19982 Timeout for Open vSwitch calls.
19984 The @code{ovs-vsctl} utility is used for the configuration and its
19985 timeout option is set by default to 5 seconds to avoid potential
19986 infinite waits blocking libvirt.
19988 Defaults to @samp{5}.
19992 @c %end of autogenerated docs
19994 @subsubheading Virtlog daemon
19995 The virtlogd service is a server side daemon component of libvirt that is
19996 used to manage logs from virtual machine consoles.
19998 This daemon is not used directly by libvirt client applications, rather it
19999 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
20000 standalone daemon, the main @code{libvirtd} daemon can be restarted without
20001 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
20002 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
20004 @deffn {Scheme Variable} virtlog-service-type
20005 This is the type of the virtlog daemon.
20006 Its value must be a @code{virtlog-configuration}.
20009 (service virtlog-service-type
20010 (virtlog-configuration
20011 (max-clients 1000)))
20015 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
20016 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
20018 Defaults to @samp{3}.
20022 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
20025 A filter allows to select a different logging level for a given category
20026 of logs The format for a filter is one of:
20037 where @code{name} is a string which is matched against the category
20038 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
20039 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
20040 be a substring of the full category name, in order to match multiple
20041 similar categories), the optional "+" prefix tells libvirt to log stack
20042 trace for each message matching name, and @code{x} is the minimal level
20043 where matching messages should be logged:
20060 Multiple filters can be defined in a single filters statement, they just
20061 need to be separated by spaces.
20063 Defaults to @samp{"3:remote 4:event"}.
20067 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
20070 An output is one of the places to save logging information The format
20071 for an output can be:
20075 output goes to stderr
20077 @item x:syslog:name
20078 use syslog for the output and use the given name as the ident
20080 @item x:file:file_path
20081 output to a file, with the given filepath
20084 output to journald logging system
20088 In all case the x prefix is the minimal level, acting as a filter
20105 Multiple outputs can be defined, they just need to be separated by
20108 Defaults to @samp{"3:stderr"}.
20112 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
20113 Maximum number of concurrent client connections to allow over all
20116 Defaults to @samp{1024}.
20120 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
20121 Maximum file size before rolling over.
20123 Defaults to @samp{2MB}
20127 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
20128 Maximum number of backup files to keep.
20130 Defaults to @samp{3}
20134 @subsubheading Transparent Emulation with QEMU
20137 @cindex @code{binfmt_misc}
20138 @code{qemu-binfmt-service-type} provides support for transparent
20139 emulation of program binaries built for different architectures---e.g.,
20140 it allows you to transparently execute an ARMv7 program on an x86_64
20141 machine. It achieves this by combining the @uref{https://www.qemu.org,
20142 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
20144 @defvr {Scheme Variable} qemu-binfmt-service-type
20145 This is the type of the QEMU/binfmt service for transparent emulation.
20146 Its value must be a @code{qemu-binfmt-configuration} object, which
20147 specifies the QEMU package to use as well as the architecture we want to
20151 (service qemu-binfmt-service-type
20152 (qemu-binfmt-configuration
20153 (platforms (lookup-qemu-platforms "arm" "aarch64" "ppc"))))
20156 In this example, we enable transparent emulation for the ARM and aarch64
20157 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
20158 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
20159 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
20162 @deftp {Data Type} qemu-binfmt-configuration
20163 This is the configuration for the @code{qemu-binfmt} service.
20166 @item @code{platforms} (default: @code{'()})
20167 The list of emulated QEMU platforms. Each item must be a @dfn{platform
20168 object} as returned by @code{lookup-qemu-platforms} (see below).
20170 @item @code{guix-support?} (default: @code{#f})
20171 When it is true, QEMU and all its dependencies are added to the build
20172 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
20173 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
20174 handlers to be used within the build environment, which in turn means
20175 that you can transparently build programs for another architecture.
20177 For example, let's suppose you're on an x86_64 machine and you have this
20181 (service qemu-binfmt-service-type
20182 (qemu-binfmt-configuration
20183 (platforms (lookup-qemu-platforms "arm"))
20184 (guix-support? #t)))
20190 guix build -s armhf-linux inkscape
20194 and it will build Inkscape for ARMv7 @emph{as if it were a native
20195 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
20196 if you'd like to test a package build for an architecture you don't have
20199 @item @code{qemu} (default: @code{qemu})
20200 The QEMU package to use.
20204 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
20205 Return the list of QEMU platform objects corresponding to
20206 @var{platforms}@dots{}. @var{platforms} must be a list of strings
20207 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
20208 @code{"mips64el"}, and so on.
20211 @deffn {Scheme Procedure} qemu-platform? @var{obj}
20212 Return true if @var{obj} is a platform object.
20215 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
20216 Return the name of @var{platform}---a string such as @code{"arm"}.
20219 @node Version Control Services
20220 @subsubsection Version Control Services
20222 The @code{(gnu services version-control)} module provides a service to
20223 allow remote access to local Git repositories. There are three options:
20224 the @code{git-daemon-service}, which provides access to repositories via
20225 the @code{git://} unsecured TCP-based protocol, extending the
20226 @code{nginx} web server to proxy some requests to
20227 @code{git-http-backend}, or providing a web interface with
20228 @code{cgit-service-type}.
20230 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
20232 Return a service that runs @command{git daemon}, a simple TCP server to
20233 expose repositories over the Git protocol for anonymous access.
20235 The optional @var{config} argument should be a
20236 @code{<git-daemon-configuration>} object, by default it allows read-only
20237 access to exported@footnote{By creating the magic file
20238 "git-daemon-export-ok" in the repository directory.} repositories under
20243 @deftp {Data Type} git-daemon-configuration
20244 Data type representing the configuration for @code{git-daemon-service}.
20247 @item @code{package} (default: @var{git})
20248 Package object of the Git distributed version control system.
20250 @item @code{export-all?} (default: @var{#f})
20251 Whether to allow access for all Git repositories, even if they do not
20252 have the @file{git-daemon-export-ok} file.
20254 @item @code{base-path} (default: @file{/srv/git})
20255 Whether to remap all the path requests as relative to the given path.
20256 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
20257 then if you later try to pull @code{git://example.com/hello.git}, git
20258 daemon will interpret the path as @code{/srv/git/hello.git}.
20260 @item @code{user-path} (default: @var{#f})
20261 Whether to allow @code{~user} notation to be used in requests. When
20262 specified with empty string, requests to @code{git://host/~alice/foo} is
20263 taken as a request to access @code{foo} repository in the home directory
20264 of user @code{alice}. If @var{(user-path "path")} is specified, the
20265 same request is taken as a request to access @code{path/foo} repository
20266 in the home directory of user @code{alice}.
20268 @item @code{listen} (default: @var{'()})
20269 Whether to listen on specific IP addresses or hostnames, defaults to
20272 @item @code{port} (default: @var{#f})
20273 Whether to listen on an alternative port, which defaults to 9418.
20275 @item @code{whitelist} (default: @var{'()})
20276 If not empty, only allow access to this list of directories.
20278 @item @code{extra-options} (default: @var{'()})
20279 Extra options will be passed to @code{git daemon}, please run
20280 @command{man git-daemon} for more information.
20285 The @code{git://} protocol lacks authentication. When you pull from a
20286 repository fetched via @code{git://}, you don't know that the data you
20287 receive was modified is really coming from the specified host, and you
20288 have your connection is subject to eavesdropping. It's better to use an
20289 authenticated and encrypted transport, such as @code{https}. Although Git allows you
20290 to serve repositories using unsophisticated file-based web servers,
20291 there is a faster protocol implemented by the @code{git-http-backend}
20292 program. This program is the back-end of a proper Git web service. It
20293 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
20294 on running the necessary @code{fcgiwrap} daemon.
20296 Guix has a separate configuration data type for serving Git repositories
20299 @deftp {Data Type} git-http-configuration
20300 Data type representing the configuration for @code{git-http-service}.
20303 @item @code{package} (default: @var{git})
20304 Package object of the Git distributed version control system.
20306 @item @code{git-root} (default: @file{/srv/git})
20307 Directory containing the Git repositories to expose to the world.
20309 @item @code{export-all?} (default: @var{#f})
20310 Whether to expose access for all Git repositories in @var{git-root},
20311 even if they do not have the @file{git-daemon-export-ok} file.
20313 @item @code{uri-path} (default: @file{/git/})
20314 Path prefix for Git access. With the default @code{/git/} prefix, this
20315 will map @code{http://@var{server}/git/@var{repo}.git} to
20316 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
20317 with this prefix are not passed on to this Git instance.
20319 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
20320 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
20325 There is no @code{git-http-service-type}, currently; instead you can
20326 create an @code{nginx-location-configuration} from a
20327 @code{git-http-configuration} and then add that location to a web
20330 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
20331 [config=(git-http-configuration)]
20332 Compute an @code{nginx-location-configuration} that corresponds to the
20333 given Git http configuration. An example nginx service definition to
20334 serve the default @file{/srv/git} over HTTPS might be:
20337 (service nginx-service-type
20338 (nginx-configuration
20341 (nginx-server-configuration
20342 (listen '("443 ssl"))
20343 (server-name "git.my-host.org")
20345 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
20346 (ssl-certificate-key
20347 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
20350 (git-http-nginx-location-configuration
20351 (git-http-configuration (uri-path "/"))))))))))
20354 This example assumes that you are using Let's Encrypt to get your TLS
20355 certificate. @xref{Certificate Services}. The default @code{certbot}
20356 service will redirect all HTTP traffic on @code{git.my-host.org} to
20357 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
20358 system services. @xref{Web Services}.
20361 @subsubheading Cgit Service
20363 @cindex Cgit service
20364 @cindex Git, web interface
20365 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
20366 repositories written in C.
20368 The following example will configure the service with default values.
20369 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
20372 (service cgit-service-type)
20375 The @code{file-object} type designates either a file-like object
20376 (@pxref{G-Expressions, file-like objects}) or a string.
20378 @c %start of fragment
20380 Available @code{cgit-configuration} fields are:
20382 @deftypevr {@code{cgit-configuration} parameter} package package
20387 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
20388 NGINX configuration.
20392 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
20393 Specifies a command which will be invoked to format the content of about
20394 pages (both top-level and for each repository).
20396 Defaults to @samp{""}.
20400 @deftypevr {@code{cgit-configuration} parameter} string agefile
20401 Specifies a path, relative to each repository path, which can be used to
20402 specify the date and time of the youngest commit in the repository.
20404 Defaults to @samp{""}.
20408 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
20409 Specifies a command that will be invoked for authenticating repository
20412 Defaults to @samp{""}.
20416 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
20417 Flag which, when set to @samp{age}, enables date ordering in the branch
20418 ref list, and when set @samp{name} enables ordering by branch name.
20420 Defaults to @samp{"name"}.
20424 @deftypevr {@code{cgit-configuration} parameter} string cache-root
20425 Path used to store the cgit cache entries.
20427 Defaults to @samp{"/var/cache/cgit"}.
20431 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
20432 Number which specifies the time-to-live, in minutes, for the cached
20433 version of repository pages accessed with a fixed SHA1.
20435 Defaults to @samp{-1}.
20439 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
20440 Number which specifies the time-to-live, in minutes, for the cached
20441 version of repository pages accessed without a fixed SHA1.
20443 Defaults to @samp{5}.
20447 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
20448 Number which specifies the time-to-live, in minutes, for the cached
20449 version of the repository summary page.
20451 Defaults to @samp{5}.
20455 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
20456 Number which specifies the time-to-live, in minutes, for the cached
20457 version of the repository index page.
20459 Defaults to @samp{5}.
20463 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
20464 Number which specifies the time-to-live, in minutes, for the result of
20465 scanning a path for Git repositories.
20467 Defaults to @samp{15}.
20471 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
20472 Number which specifies the time-to-live, in minutes, for the cached
20473 version of the repository about page.
20475 Defaults to @samp{15}.
20479 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
20480 Number which specifies the time-to-live, in minutes, for the cached
20481 version of snapshots.
20483 Defaults to @samp{5}.
20487 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
20488 The maximum number of entries in the cgit cache. When set to @samp{0},
20489 caching is disabled.
20491 Defaults to @samp{0}.
20495 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
20496 Sort items in the repo list case sensitively.
20498 Defaults to @samp{#t}.
20502 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
20503 List of common prefixes which, when combined with a repository URL,
20504 generates valid clone URLs for the repository.
20506 Defaults to @samp{()}.
20510 @deftypevr {@code{cgit-configuration} parameter} list clone-url
20511 List of @code{clone-url} templates.
20513 Defaults to @samp{()}.
20517 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
20518 Command which will be invoked to format commit messages.
20520 Defaults to @samp{""}.
20524 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
20525 Flag which, when set to @samp{date}, enables strict date ordering in the
20526 commit log, and when set to @samp{topo} enables strict topological
20529 Defaults to @samp{"git log"}.
20533 @deftypevr {@code{cgit-configuration} parameter} file-object css
20534 URL which specifies the css document to include in all cgit pages.
20536 Defaults to @samp{"/share/cgit/cgit.css"}.
20540 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
20541 Specifies a command which will be invoked to format names and email
20542 address of committers, authors, and taggers, as represented in various
20543 places throughout the cgit interface.
20545 Defaults to @samp{""}.
20549 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
20550 Flag which, when set to @samp{#t}, will make cgit generate a HTML
20551 fragment suitable for embedding in other HTML pages.
20553 Defaults to @samp{#f}.
20557 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
20558 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
20559 commit history graph to the left of the commit messages in the
20560 repository log page.
20562 Defaults to @samp{#f}.
20566 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
20567 Flag which, when set to @samp{#t}, allows all filter settings to be
20568 overridden in repository-specific cgitrc files.
20570 Defaults to @samp{#f}.
20574 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
20575 Flag which, when set to @samp{#t}, allows users to follow a file in the
20578 Defaults to @samp{#f}.
20582 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
20583 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
20586 Defaults to @samp{#t}.
20590 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
20591 Flag which, when set to @samp{#t}, will make cgit generate extra links
20592 "summary", "commit", "tree" for each repo in the repository index.
20594 Defaults to @samp{#f}.
20598 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
20599 Flag which, when set to @samp{#t}, will make cgit display the owner of
20600 each repo in the repository index.
20602 Defaults to @samp{#t}.
20606 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
20607 Flag which, when set to @samp{#t}, will make cgit print the number of
20608 modified files for each commit on the repository log page.
20610 Defaults to @samp{#f}.
20614 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
20615 Flag which, when set to @samp{#t}, will make cgit print the number of
20616 added and removed lines for each commit on the repository log page.
20618 Defaults to @samp{#f}.
20622 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
20623 Flag which, when set to @code{#t}, will make cgit display remote
20624 branches in the summary and refs views.
20626 Defaults to @samp{#f}.
20630 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
20631 Flag which, when set to @code{1}, will make cgit use the subject of the
20632 parent commit as link text when generating links to parent commits in
20635 Defaults to @samp{#f}.
20639 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
20640 Flag which, when set to @samp{#t}, will make cgit use the subject of the
20641 parent commit as link text when generating links to parent commits in
20644 Defaults to @samp{#f}.
20648 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
20649 Flag which, when set to @samp{#t}, will make cgit generate linenumber
20650 links for plaintext blobs printed in the tree view.
20652 Defaults to @samp{#t}.
20656 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
20657 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
20658 set any repo specific settings.
20660 Defaults to @samp{#f}.
20664 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
20665 URL used as link to a shortcut icon for cgit.
20667 Defaults to @samp{"/favicon.ico"}.
20671 @deftypevr {@code{cgit-configuration} parameter} string footer
20672 The content of the file specified with this option will be included
20673 verbatim at the bottom of all pages (i.e. it replaces the standard
20674 "generated by..." message).
20676 Defaults to @samp{""}.
20680 @deftypevr {@code{cgit-configuration} parameter} string head-include
20681 The content of the file specified with this option will be included
20682 verbatim in the HTML HEAD section on all pages.
20684 Defaults to @samp{""}.
20688 @deftypevr {@code{cgit-configuration} parameter} string header
20689 The content of the file specified with this option will be included
20690 verbatim at the top of all pages.
20692 Defaults to @samp{""}.
20696 @deftypevr {@code{cgit-configuration} parameter} file-object include
20697 Name of a configfile to include before the rest of the current config-
20700 Defaults to @samp{""}.
20704 @deftypevr {@code{cgit-configuration} parameter} string index-header
20705 The content of the file specified with this option will be included
20706 verbatim above the repository index.
20708 Defaults to @samp{""}.
20712 @deftypevr {@code{cgit-configuration} parameter} string index-info
20713 The content of the file specified with this option will be included
20714 verbatim below the heading on the repository index page.
20716 Defaults to @samp{""}.
20720 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
20721 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
20722 in the servers timezone.
20724 Defaults to @samp{#f}.
20728 @deftypevr {@code{cgit-configuration} parameter} file-object logo
20729 URL which specifies the source of an image which will be used as a logo
20732 Defaults to @samp{"/share/cgit/cgit.png"}.
20736 @deftypevr {@code{cgit-configuration} parameter} string logo-link
20737 URL loaded when clicking on the cgit logo image.
20739 Defaults to @samp{""}.
20743 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
20744 Command which will be invoked to format the Owner column of the main
20747 Defaults to @samp{""}.
20751 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
20752 Number of items to display in atom feeds view.
20754 Defaults to @samp{10}.
20758 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
20759 Number of entries to list per page in "log" view.
20761 Defaults to @samp{50}.
20765 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
20766 Number of commit message characters to display in "log" view.
20768 Defaults to @samp{80}.
20772 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
20773 Specifies the number of entries to list per page on the repository index
20776 Defaults to @samp{50}.
20780 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
20781 Specifies the maximum number of repo description characters to display
20782 on the repository index page.
20784 Defaults to @samp{80}.
20788 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
20789 Specifies the maximum size of a blob to display HTML for in KBytes.
20791 Defaults to @samp{0}.
20795 @deftypevr {@code{cgit-configuration} parameter} string max-stats
20796 Maximum statistics period. Valid values are @samp{week},@samp{month},
20797 @samp{quarter} and @samp{year}.
20799 Defaults to @samp{""}.
20803 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
20804 Mimetype for the specified filename extension.
20806 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
20807 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
20808 "image/png") (svg "image/svg+xml"))}.
20812 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
20813 Specifies the file to use for automatic mimetype lookup.
20815 Defaults to @samp{""}.
20819 @deftypevr {@code{cgit-configuration} parameter} string module-link
20820 Text which will be used as the formatstring for a hyperlink when a
20821 submodule is printed in a directory listing.
20823 Defaults to @samp{""}.
20827 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
20828 If set to the value @samp{#t} caching will be disabled.
20830 Defaults to @samp{#f}.
20834 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
20835 If set to @samp{#t} showing full author email addresses will be
20838 Defaults to @samp{#f}.
20842 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
20843 Flag which, when set to @samp{#t}, will make cgit omit the standard
20844 header on all pages.
20846 Defaults to @samp{#f}.
20850 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
20851 A list of subdirectories inside of @code{repository-directory}, relative
20852 to it, that should loaded as Git repositories. An empty list means that
20853 all subdirectories will be loaded.
20855 Defaults to @samp{()}.
20859 @deftypevr {@code{cgit-configuration} parameter} file-object readme
20860 Text which will be used as default value for @code{cgit-repo-readme}.
20862 Defaults to @samp{""}.
20866 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
20867 If set to @code{#t} and @code{repository-directory} is enabled, if any
20868 repositories are found with a suffix of @code{.git}, this suffix will be
20869 removed for the URL and name.
20871 Defaults to @samp{#f}.
20875 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
20876 Maximum number of files to consider when detecting renames.
20878 Defaults to @samp{-1}.
20882 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
20883 The way in which repositories in each section are sorted.
20885 Defaults to @samp{""}.
20889 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
20890 Text used as content for the @code{robots} meta-tag.
20892 Defaults to @samp{("noindex" "nofollow")}.
20896 @deftypevr {@code{cgit-configuration} parameter} string root-desc
20897 Text printed below the heading on the repository index page.
20899 Defaults to @samp{"a fast webinterface for the git dscm"}.
20903 @deftypevr {@code{cgit-configuration} parameter} string root-readme
20904 The content of the file specified with this option will be included
20905 verbatim below thef "about" link on the repository index page.
20907 Defaults to @samp{""}.
20911 @deftypevr {@code{cgit-configuration} parameter} string root-title
20912 Text printed as heading on the repository index page.
20914 Defaults to @samp{""}.
20918 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
20919 If set to @samp{#t} and repository-directory is enabled,
20920 repository-directory will recurse into directories whose name starts
20921 with a period. Otherwise, repository-directory will stay away from such
20922 directories, considered as "hidden". Note that this does not apply to
20923 the ".git" directory in non-bare repos.
20925 Defaults to @samp{#f}.
20929 @deftypevr {@code{cgit-configuration} parameter} list snapshots
20930 Text which specifies the default set of snapshot formats that cgit
20931 generates links for.
20933 Defaults to @samp{()}.
20937 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
20938 Name of the directory to scan for repositories (represents
20941 Defaults to @samp{"/srv/git"}.
20945 @deftypevr {@code{cgit-configuration} parameter} string section
20946 The name of the current repository section - all repositories defined
20947 after this option will inherit the current section name.
20949 Defaults to @samp{""}.
20953 @deftypevr {@code{cgit-configuration} parameter} string section-sort
20954 Flag which, when set to @samp{1}, will sort the sections on the
20955 repository listing by name.
20957 Defaults to @samp{""}.
20961 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
20962 A number which, if defined prior to repository-directory, specifies how
20963 many path elements from each repo path to use as a default section name.
20965 Defaults to @samp{0}.
20969 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
20970 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
20973 Defaults to @samp{#f}.
20977 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
20978 Specifies a command which will be invoked to format plaintext blobs in
20981 Defaults to @samp{""}.
20985 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
20986 Specifies the number of branches to display in the repository "summary"
20989 Defaults to @samp{10}.
20993 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
20994 Specifies the number of log entries to display in the repository
20997 Defaults to @samp{10}.
21001 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
21002 Specifies the number of tags to display in the repository "summary"
21005 Defaults to @samp{10}.
21009 @deftypevr {@code{cgit-configuration} parameter} string strict-export
21010 Filename which, if specified, needs to be present within the repository
21011 for cgit to allow access to that repository.
21013 Defaults to @samp{""}.
21017 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
21018 URL which, if specified, will be used as root for all cgit links.
21020 Defaults to @samp{"/"}.
21024 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
21025 A list of @dfn{cgit-repo} records to use with config.
21027 Defaults to @samp{()}.
21029 Available @code{repository-cgit-configuration} fields are:
21031 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
21032 A mask of snapshot formats for this repo that cgit generates links for,
21033 restricted by the global @code{snapshots} setting.
21035 Defaults to @samp{()}.
21039 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
21040 Override the default @code{source-filter}.
21042 Defaults to @samp{""}.
21046 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
21047 The relative URL used to access the repository.
21049 Defaults to @samp{""}.
21053 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
21054 Override the default @code{about-filter}.
21056 Defaults to @samp{""}.
21060 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
21061 Flag which, when set to @samp{age}, enables date ordering in the branch
21062 ref list, and when set to @samp{name} enables ordering by branch name.
21064 Defaults to @samp{""}.
21068 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
21069 A list of URLs which can be used to clone repo.
21071 Defaults to @samp{()}.
21075 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
21076 Override the default @code{commit-filter}.
21078 Defaults to @samp{""}.
21082 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
21083 Flag which, when set to @samp{date}, enables strict date ordering in the
21084 commit log, and when set to @samp{topo} enables strict topological
21087 Defaults to @samp{""}.
21091 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
21092 The name of the default branch for this repository. If no such branch
21093 exists in the repository, the first branch name (when sorted) is used as
21094 default instead. By default branch pointed to by HEAD, or "master" if
21095 there is no suitable HEAD.
21097 Defaults to @samp{""}.
21101 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
21102 The value to show as repository description.
21104 Defaults to @samp{""}.
21108 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
21109 The value to show as repository homepage.
21111 Defaults to @samp{""}.
21115 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
21116 Override the default @code{email-filter}.
21118 Defaults to @samp{""}.
21122 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
21123 A flag which can be used to disable the global setting
21124 @code{enable-commit-graph?}.
21126 Defaults to @samp{disabled}.
21130 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
21131 A flag which can be used to disable the global setting
21132 @code{enable-log-filecount?}.
21134 Defaults to @samp{disabled}.
21138 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
21139 A flag which can be used to disable the global setting
21140 @code{enable-log-linecount?}.
21142 Defaults to @samp{disabled}.
21146 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
21147 Flag which, when set to @code{#t}, will make cgit display remote
21148 branches in the summary and refs views.
21150 Defaults to @samp{disabled}.
21154 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
21155 A flag which can be used to override the global setting
21156 @code{enable-subject-links?}.
21158 Defaults to @samp{disabled}.
21162 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
21163 A flag which can be used to override the global setting
21164 @code{enable-html-serving?}.
21166 Defaults to @samp{disabled}.
21170 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
21171 Flag which, when set to @code{#t}, hides the repository from the
21174 Defaults to @samp{#f}.
21178 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
21179 Flag which, when set to @samp{#t}, ignores the repository.
21181 Defaults to @samp{#f}.
21185 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
21186 URL which specifies the source of an image which will be used as a logo
21187 on this repo’s pages.
21189 Defaults to @samp{""}.
21193 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
21194 URL loaded when clicking on the cgit logo image.
21196 Defaults to @samp{""}.
21200 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
21201 Override the default @code{owner-filter}.
21203 Defaults to @samp{""}.
21207 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
21208 Text which will be used as the formatstring for a hyperlink when a
21209 submodule is printed in a directory listing. The arguments for the
21210 formatstring are the path and SHA1 of the submodule commit.
21212 Defaults to @samp{""}.
21216 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
21217 Text which will be used as the formatstring for a hyperlink when a
21218 submodule with the specified subdirectory path is printed in a directory
21221 Defaults to @samp{()}.
21225 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
21226 Override the default maximum statistics period.
21228 Defaults to @samp{""}.
21232 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
21233 The value to show as repository name.
21235 Defaults to @samp{""}.
21239 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
21240 A value used to identify the owner of the repository.
21242 Defaults to @samp{""}.
21246 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
21247 An absolute path to the repository directory.
21249 Defaults to @samp{""}.
21253 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
21254 A path (relative to repo) which specifies a file to include verbatim as
21255 the "About" page for this repo.
21257 Defaults to @samp{""}.
21261 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
21262 The name of the current repository section - all repositories defined
21263 after this option will inherit the current section name.
21265 Defaults to @samp{""}.
21269 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
21270 Extra options will be appended to cgitrc file.
21272 Defaults to @samp{()}.
21278 @deftypevr {@code{cgit-configuration} parameter} list extra-options
21279 Extra options will be appended to cgitrc file.
21281 Defaults to @samp{()}.
21286 @c %end of fragment
21288 However, it could be that you just want to get a @code{cgitrc} up and
21289 running. In that case, you can pass an @code{opaque-cgit-configuration}
21290 as a record to @code{cgit-service-type}. As its name indicates, an
21291 opaque configuration does not have easy reflective capabilities.
21293 Available @code{opaque-cgit-configuration} fields are:
21295 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
21299 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
21300 The contents of the @code{cgitrc}, as a string.
21303 For example, if your @code{cgitrc} is just the empty string, you
21304 could instantiate a cgit service like this:
21307 (service cgit-service-type
21308 (opaque-cgit-configuration
21312 @subsubheading Gitolite Service
21314 @cindex Gitolite service
21315 @cindex Git, hosting
21316 @uref{http://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
21317 repositories on a central server.
21319 Gitolite can handle multiple repositories and users, and supports flexible
21320 configuration of the permissions for the users on the repositories.
21322 The following example will configure Gitolite using the default @code{git}
21323 user, and the provided SSH public key.
21326 (service gitolite-service-type
21327 (gitolite-configuration
21328 (admin-pubkey (plain-file
21330 "ssh-rsa AAAA... guix@@example.com"))))
21333 Gitolite is configured through a special admin repository which you can clone,
21334 for example, if you setup Gitolite on @code{example.com}, you would run the
21335 following command to clone the admin repository.
21338 git clone git@@example.com:gitolite-admin
21341 When the Gitolite service is activated, the provided @code{admin-pubkey} will
21342 be inserted in to the @file{keydir} directory in the gitolite-admin
21343 repository. If this results in a change in the repository, it will be
21344 committed using the message ``gitolite setup by GNU Guix''.
21346 @deftp {Data Type} gitolite-configuration
21347 Data type representing the configuration for @code{gitolite-service-type}.
21350 @item @code{package} (default: @var{gitolite})
21351 Gitolite package to use.
21353 @item @code{user} (default: @var{git})
21354 User to use for Gitolite. This will be user that you use when accessing
21357 @item @code{group} (default: @var{git})
21358 Group to use for Gitolite.
21360 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
21361 Directory in which to store the Gitolite configuration and repositories.
21363 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
21364 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
21365 representing the configuration for Gitolite.
21367 @item @code{admin-pubkey} (default: @var{#f})
21368 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
21369 setup Gitolite. This will be inserted in to the @file{keydir} directory
21370 within the gitolite-admin repository.
21372 To specify the SSH key as a string, use the @code{plain-file} function.
21375 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
21381 @deftp {Data Type} gitolite-rc-file
21382 Data type representing the Gitolite RC file.
21385 @item @code{umask} (default: @code{#o0077})
21386 This controls the permissions Gitolite sets on the repositories and their
21389 A value like @code{#o0027} will give read access to the group used by Gitolite
21390 (by default: @code{git}). This is necessary when using Gitolite with software
21391 like cgit or gitweb.
21393 @item @code{git-config-keys} (default: @code{""})
21394 Gitolite allows you to set git config values using the "config" keyword. This
21395 setting allows control over the config keys to accept.
21397 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
21398 Set the role names allowed to be used by users running the perms command.
21400 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
21401 This setting controls the commands and features to enable within Gitolite.
21407 @node Game Services
21408 @subsubsection Game Services
21410 @subsubheading The Battle for Wesnoth Service
21412 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
21413 based tactical strategy game, with several single player campaigns, and
21414 multiplayer games (both networked and local).
21416 @defvar {Scheme Variable} wesnothd-service-type
21417 Service type for the wesnothd service. Its value must be a
21418 @code{wesnothd-configuration} object. To run wesnothd in the default
21419 configuration, instantiate it as:
21422 (service wesnothd-service-type)
21426 @deftp {Data Type} wesnothd-configuration
21427 Data type representing the configuration of @command{wesnothd}.
21430 @item @code{package} (default: @code{wesnoth-server})
21431 The wesnoth server package to use.
21433 @item @code{port} (default: @code{15000})
21434 The port to bind the server to.
21438 @node Miscellaneous Services
21439 @subsubsection Miscellaneous Services
21441 @cindex fingerprint
21442 @subsubheading Fingerprint Service
21444 The @code{(gnu services fingerprint)} module provides a DBus service to
21445 read and identify fingerprints via a fingerprint sensor.
21447 @defvr {Scheme Variable} fprintd-service-type
21448 The service type for @command{fprintd}, which provides the fingerprint
21449 reading capability.
21452 (service fprintd-service-type)
21457 @subsubheading System Control Service
21459 The @code{(gnu services sysctl)} provides a service to configure kernel
21460 parameters at boot.
21462 @defvr {Scheme Variable} sysctl-service-type
21463 The service type for @command{sysctl}, which modifies kernel parameters
21464 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
21468 (service sysctl-service-type
21469 (sysctl-configuration
21470 (settings '(("net.ipv4.ip_forward" . "1")))))
21474 @deftp {Data Type} sysctl-configuration
21475 The data type representing the configuration of @command{sysctl}.
21478 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
21479 The @command{sysctl} executable to use.
21481 @item @code{settings} (default: @code{'()})
21482 An association list specifies kernel parameters and their values.
21487 @subsubheading PC/SC Smart Card Daemon Service
21489 The @code{(gnu services security-token)} module provides the following service
21490 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
21491 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
21492 manager that coordinates communications with smart card readers, smart cards
21493 and cryptographic tokens that are connected to the system.
21495 @defvr {Scheme Variable} pcscd-service-type
21496 Service type for the @command{pcscd} service. Its value must be a
21497 @code{pcscd-configuration} object. To run pcscd in the default
21498 configuration, instantiate it as:
21501 (service pcscd-service-type)
21505 @deftp {Data Type} pcscd-configuration
21506 The data type representing the configuration of @command{pcscd}.
21509 @item @code{pcsc-lite} (default: @code{pcsc-lite})
21510 The pcsc-lite package that provides pcscd.
21511 @item @code{usb-drivers} (default: @code{(list ccid)})
21512 List of packages that provide USB drivers to pcscd. Drivers are expected to be
21513 under @file{pcsc/drivers} in the store directory of the package.
21518 @subsubheading Lirc Service
21520 The @code{(gnu services lirc)} module provides the following service.
21522 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
21523 [#:device #f] [#:driver #f] [#:config-file #f] @
21524 [#:extra-options '()]
21525 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
21526 decodes infrared signals from remote controls.
21528 Optionally, @var{device}, @var{driver} and @var{config-file}
21529 (configuration file name) may be specified. See @command{lircd} manual
21532 Finally, @var{extra-options} is a list of additional command-line options
21533 passed to @command{lircd}.
21537 @subsubheading Spice Service
21539 The @code{(gnu services spice)} module provides the following service.
21541 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
21542 Returns a service that runs @url{http://www.spice-space.org,VDAGENT}, a daemon
21543 that enables sharing the clipboard with a vm and setting the guest display
21544 resolution when the graphical console window resizes.
21547 @subsubsection Dictionary Services
21549 The @code{(gnu services dict)} module provides the following service:
21551 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
21552 Return a service that runs the @command{dicod} daemon, an implementation
21553 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
21555 The optional @var{config} argument specifies the configuration for
21556 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
21557 default it serves the GNU Collaborative International Dictonary of English.
21559 You can add @command{open localhost} to your @file{~/.dico} file to make
21560 @code{localhost} the default server for @command{dico} client
21561 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
21564 @deftp {Data Type} dicod-configuration
21565 Data type representing the configuration of dicod.
21568 @item @code{dico} (default: @var{dico})
21569 Package object of the GNU Dico dictionary server.
21571 @item @code{interfaces} (default: @var{'("localhost")})
21572 This is the list of IP addresses and ports and possibly socket file
21573 names to listen to (@pxref{Server Settings, @code{listen} directive,,
21574 dico, GNU Dico Manual}).
21576 @item @code{handlers} (default: @var{'()})
21577 List of @code{<dicod-handler>} objects denoting handlers (module instances).
21579 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
21580 List of @code{<dicod-database>} objects denoting dictionaries to be served.
21584 @deftp {Data Type} dicod-handler
21585 Data type representing a dictionary handler (module instance).
21589 Name of the handler (module instance).
21591 @item @code{module} (default: @var{#f})
21592 Name of the dicod module of the handler (instance). If it is @code{#f},
21593 the module has the same name as the handler.
21594 (@pxref{Modules,,, dico, GNU Dico Manual}).
21596 @item @code{options}
21597 List of strings or gexps representing the arguments for the module handler
21601 @deftp {Data Type} dicod-database
21602 Data type representing a dictionary database.
21606 Name of the database, will be used in DICT commands.
21608 @item @code{handler}
21609 Name of the dicod handler (module instance) used by this database
21610 (@pxref{Handlers,,, dico, GNU Dico Manual}).
21612 @item @code{complex?} (default: @var{#f})
21613 Whether the database configuration complex. The complex configuration
21614 will need a corresponding @code{<dicod-handler>} object, otherwise not.
21616 @item @code{options}
21617 List of strings or gexps representing the arguments for the database
21618 (@pxref{Databases,,, dico, GNU Dico Manual}).
21622 @defvr {Scheme Variable} %dicod-database:gcide
21623 A @code{<dicod-database>} object serving the GNU Collaborative International
21624 Dictionary of English using the @code{gcide} package.
21627 The following is an example @code{dicod-service} configuration.
21630 (dicod-service #:config
21631 (dicod-configuration
21632 (handlers (list (dicod-handler
21636 (list #~(string-append "dbdir=" #$wordnet))))))
21637 (databases (list (dicod-database
21640 (handler "wordnet")
21641 (options '("database=wn")))
21642 %dicod-database:gcide))))
21645 @node Setuid Programs
21646 @subsection Setuid Programs
21648 @cindex setuid programs
21649 Some programs need to run with ``root'' privileges, even when they are
21650 launched by unprivileged users. A notorious example is the
21651 @command{passwd} program, which users can run to change their
21652 password, and which needs to access the @file{/etc/passwd} and
21653 @file{/etc/shadow} files---something normally restricted to root, for
21654 obvious security reasons. To address that, these executables are
21655 @dfn{setuid-root}, meaning that they always run with root privileges
21656 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
21657 for more info about the setuid mechanism.)
21659 The store itself @emph{cannot} contain setuid programs: that would be a
21660 security issue since any user on the system can write derivations that
21661 populate the store (@pxref{The Store}). Thus, a different mechanism is
21662 used: instead of changing the setuid bit directly on files that are in
21663 the store, we let the system administrator @emph{declare} which programs
21664 should be setuid root.
21666 The @code{setuid-programs} field of an @code{operating-system}
21667 declaration contains a list of G-expressions denoting the names of
21668 programs to be setuid-root (@pxref{Using the Configuration System}).
21669 For instance, the @command{passwd} program, which is part of the Shadow
21670 package, can be designated by this G-expression (@pxref{G-Expressions}):
21673 #~(string-append #$shadow "/bin/passwd")
21676 A default set of setuid programs is defined by the
21677 @code{%setuid-programs} variable of the @code{(gnu system)} module.
21679 @defvr {Scheme Variable} %setuid-programs
21680 A list of G-expressions denoting common programs that are setuid-root.
21682 The list includes commands such as @command{passwd}, @command{ping},
21683 @command{su}, and @command{sudo}.
21686 Under the hood, the actual setuid programs are created in the
21687 @file{/run/setuid-programs} directory at system activation time. The
21688 files in this directory refer to the ``real'' binaries, which are in the
21691 @node X.509 Certificates
21692 @subsection X.509 Certificates
21694 @cindex HTTPS, certificates
21695 @cindex X.509 certificates
21697 Web servers available over HTTPS (that is, HTTP over the transport-layer
21698 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
21699 that the client can then use to @emph{authenticate} the server. To do
21700 that, clients verify that the server's certificate is signed by a
21701 so-called @dfn{certificate authority} (CA). But to verify the CA's
21702 signature, clients must have first acquired the CA's certificate.
21704 Web browsers such as GNU@tie{}IceCat include their own set of CA
21705 certificates, such that they are able to verify CA signatures
21708 However, most other programs that can talk HTTPS---@command{wget},
21709 @command{git}, @command{w3m}, etc.---need to be told where CA
21710 certificates can be found.
21712 @cindex @code{nss-certs}
21713 In GuixSD, this is done by adding a package that provides certificates
21714 to the @code{packages} field of the @code{operating-system} declaration
21715 (@pxref{operating-system Reference}). GuixSD includes one such package,
21716 @code{nss-certs}, which is a set of CA certificates provided as part of
21717 Mozilla's Network Security Services.
21719 Note that it is @emph{not} part of @var{%base-packages}, so you need to
21720 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
21721 most applications and libraries look for certificates by default, points
21722 to the certificates installed globally.
21724 Unprivileged users, including users of Guix on a foreign distro,
21725 can also install their own certificate package in
21726 their profile. A number of environment variables need to be defined so
21727 that applications and libraries know where to find them. Namely, the
21728 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
21729 variables. Some applications add their own environment variables; for
21730 instance, the Git version control system honors the certificate bundle
21731 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
21732 would typically run something like:
21735 $ guix package -i nss-certs
21736 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
21737 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
21738 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
21741 As another example, R requires the @code{CURL_CA_BUNDLE} environment
21742 variable to point to a certificate bundle, so you would have to run
21743 something like this:
21746 $ guix package -i nss-certs
21747 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
21750 For other applications you may want to look up the required environment
21751 variable in the relevant documentation.
21754 @node Name Service Switch
21755 @subsection Name Service Switch
21757 @cindex name service switch
21759 The @code{(gnu system nss)} module provides bindings to the
21760 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
21761 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
21762 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
21763 extended with new ``name'' lookup methods for system databases, which
21764 includes host names, service names, user accounts, and more (@pxref{Name
21765 Service Switch, System Databases and Name Service Switch,, libc, The GNU
21766 C Library Reference Manual}).
21768 The NSS configuration specifies, for each system database, which lookup
21769 method is to be used, and how the various methods are chained
21770 together---for instance, under which circumstances NSS should try the
21771 next method in the list. The NSS configuration is given in the
21772 @code{name-service-switch} field of @code{operating-system} declarations
21773 (@pxref{operating-system Reference, @code{name-service-switch}}).
21776 @cindex .local, host name lookup
21777 As an example, the declaration below configures the NSS to use the
21778 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
21779 back-end}, which supports host name lookups over multicast DNS (mDNS)
21780 for host names ending in @code{.local}:
21783 (name-service-switch
21784 (hosts (list %files ;first, check /etc/hosts
21786 ;; If the above did not succeed, try
21787 ;; with 'mdns_minimal'.
21789 (name "mdns_minimal")
21791 ;; 'mdns_minimal' is authoritative for
21792 ;; '.local'. When it returns "not found",
21793 ;; no need to try the next methods.
21794 (reaction (lookup-specification
21795 (not-found => return))))
21797 ;; Then fall back to DNS.
21801 ;; Finally, try with the "full" 'mdns'.
21806 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
21807 contains this configuration, so you will not have to type it if all you
21808 want is to have @code{.local} host lookup working.
21810 Note that, in this case, in addition to setting the
21811 @code{name-service-switch} of the @code{operating-system} declaration,
21812 you also need to use @code{avahi-service} (@pxref{Networking Services,
21813 @code{avahi-service}}), or @var{%desktop-services}, which includes it
21814 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
21815 to the name service cache daemon (@pxref{Base Services,
21816 @code{nscd-service}}).
21818 For convenience, the following variables provide typical NSS
21821 @defvr {Scheme Variable} %default-nss
21822 This is the default name service switch configuration, a
21823 @code{name-service-switch} object.
21826 @defvr {Scheme Variable} %mdns-host-lookup-nss
21827 This is the name service switch configuration with support for host name
21828 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
21831 The reference for name service switch configuration is given below. It
21832 is a direct mapping of the configuration file format of the C library , so
21833 please refer to the C library manual for more information (@pxref{NSS
21834 Configuration File,,, libc, The GNU C Library Reference Manual}).
21835 Compared to the configuration file format of libc NSS, it has the advantage
21836 not only of adding this warm parenthetic feel that we like, but also
21837 static checks: you will know about syntax errors and typos as soon as you
21838 run @command{guix system}.
21840 @deftp {Data Type} name-service-switch
21842 This is the data type representation the configuration of libc's name
21843 service switch (NSS). Each field below represents one of the supported
21860 The system databases handled by the NSS. Each of these fields must be a
21861 list of @code{<name-service>} objects (see below).
21865 @deftp {Data Type} name-service
21867 This is the data type representing an actual name service and the
21868 associated lookup action.
21872 A string denoting the name service (@pxref{Services in the NSS
21873 configuration,,, libc, The GNU C Library Reference Manual}).
21875 Note that name services listed here must be visible to nscd. This is
21876 achieved by passing the @code{#:name-services} argument to
21877 @code{nscd-service} the list of packages providing the needed name
21878 services (@pxref{Base Services, @code{nscd-service}}).
21881 An action specified using the @code{lookup-specification} macro
21882 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
21883 Reference Manual}). For example:
21886 (lookup-specification (unavailable => continue)
21887 (success => return))
21892 @node Initial RAM Disk
21893 @subsection Initial RAM Disk
21896 @cindex initial RAM disk
21897 For bootstrapping purposes, the Linux-Libre kernel is passed an
21898 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
21899 root file system as well as an initialization script. The latter is
21900 responsible for mounting the real root file system, and for loading any
21901 kernel modules that may be needed to achieve that.
21903 The @code{initrd-modules} field of an @code{operating-system}
21904 declaration allows you to specify Linux-libre kernel modules that must
21905 be available in the initrd. In particular, this is where you would list
21906 modules needed to actually drive the hard disk where your root partition
21907 is---although the default value of @code{initrd-modules} should cover
21908 most use cases. For example, assuming you need the @code{megaraid_sas}
21909 module in addition to the default modules to be able to access your root
21910 file system, you would write:
21915 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
21918 @defvr {Scheme Variable} %base-initrd-modules
21919 This is the list of kernel modules included in the initrd by default.
21922 Furthermore, if you need lower-level customization, the @code{initrd}
21923 field of an @code{operating-system} declaration allows
21924 you to specify which initrd you would like to use. The @code{(gnu
21925 system linux-initrd)} module provides three ways to build an initrd: the
21926 high-level @code{base-initrd} procedure and the low-level
21927 @code{raw-initrd} and @code{expression->initrd} procedures.
21929 The @code{base-initrd} procedure is intended to cover most common uses.
21930 For example, if you want to add a bunch of kernel modules to be loaded
21931 at boot time, you can define the @code{initrd} field of the operating
21932 system declaration like this:
21935 (initrd (lambda (file-systems . rest)
21936 ;; Create a standard initrd but set up networking
21937 ;; with the parameters QEMU expects by default.
21938 (apply base-initrd file-systems
21939 #:qemu-networking? #t
21943 The @code{base-initrd} procedure also handles common use cases that
21944 involves using the system as a QEMU guest, or as a ``live'' system with
21945 volatile root file system.
21947 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
21948 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
21949 such as trying to guess which kernel modules and packages should be included
21950 to the initrd. An example use of @code{raw-initrd} is when a user has
21951 a custom Linux kernel configuration and default kernel modules included by
21952 @code{base-initrd} are not available.
21954 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
21955 honors several options passed on the Linux kernel command line
21956 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
21957 @code{-append} option of QEMU), notably:
21960 @item --load=@var{boot}
21961 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
21962 program, once it has mounted the root file system.
21964 GuixSD uses this option to yield control to a boot program that runs the
21965 service activation programs and then spawns the GNU@tie{}Shepherd, the
21966 initialization system.
21968 @item --root=@var{root}
21969 Mount @var{root} as the root file system. @var{root} can be a
21970 device name like @code{/dev/sda1}, a file system label, or a file system
21973 @item --system=@var{system}
21974 Have @file{/run/booted-system} and @file{/run/current-system} point to
21977 @item modprobe.blacklist=@var{modules}@dots{}
21978 @cindex module, black-listing
21979 @cindex black list, of kernel modules
21980 Instruct the initial RAM disk as well as the @command{modprobe} command
21981 (from the kmod package) to refuse to load @var{modules}. @var{modules}
21982 must be a comma-separated list of module names---e.g.,
21983 @code{usbkbd,9pnet}.
21986 Start a read-eval-print loop (REPL) from the initial RAM disk before it
21987 tries to load kernel modules and to mount the root file system. Our
21988 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
21989 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
21990 Manual}, for more information on Guile's REPL.
21994 Now that you know all the features that initial RAM disks produced by
21995 @code{base-initrd} and @code{raw-initrd} provide,
21996 here is how to use it and customize it further.
21999 @cindex initial RAM disk
22000 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
22001 [#:linux-modules '()] [#:mapped-devices '()] @
22002 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
22003 Return a derivation that builds a raw initrd. @var{file-systems} is
22004 a list of file systems to be mounted by the initrd, possibly in addition to
22005 the root file system specified on the kernel command line via @code{--root}.
22006 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
22007 @var{mapped-devices} is a list of device mappings to realize before
22008 @var{file-systems} are mounted (@pxref{Mapped Devices}).
22009 @var{helper-packages} is a list of packages to be copied in the initrd. It may
22010 include @code{e2fsck/static} or other packages needed by the initrd to check
22011 the root file system.
22013 When @var{qemu-networking?} is true, set up networking with the standard QEMU
22014 parameters. When @var{virtio?} is true, load additional modules so that the
22015 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
22017 When @var{volatile-root?} is true, the root file system is writable but any changes
22021 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
22022 [#:mapped-devices '()] [#:qemu-networking? #f] [#:volatile-root? #f]@
22023 [#:linux-modules '()]
22024 Return as a file-like object a generic initrd, with kernel
22025 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
22026 mounted by the initrd, possibly in addition to the root file system specified
22027 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
22028 mappings to realize before @var{file-systems} are mounted.
22030 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
22032 The initrd is automatically populated with all the kernel modules necessary
22033 for @var{file-systems} and for the given options. Additional kernel
22034 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
22035 loaded at boot time in the order in which they appear.
22038 Needless to say, the initrds we produce and use embed a
22039 statically-linked Guile, and the initialization program is a Guile
22040 program. That gives a lot of flexibility. The
22041 @code{expression->initrd} procedure builds such an initrd, given the
22042 program to run in that initrd.
22044 @deffn {Scheme Procedure} expression->initrd @var{exp} @
22045 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
22046 Return as a file-like object a Linux initrd (a gzipped cpio archive)
22047 containing @var{guile} and that evaluates @var{exp}, a G-expression,
22048 upon booting. All the derivations referenced by @var{exp} are
22049 automatically copied to the initrd.
22052 @node Bootloader Configuration
22053 @subsection Bootloader Configuration
22056 @cindex boot loader
22058 The operating system supports multiple bootloaders. The bootloader is
22059 configured using @code{bootloader-configuration} declaration. All the
22060 fields of this structure are bootloader agnostic except for one field,
22061 @code{bootloader} that indicates the bootloader to be configured and
22064 Some of the bootloaders do not honor every field of
22065 @code{bootloader-configuration}. For instance, the extlinux
22066 bootloader does not support themes and thus ignores the @code{theme}
22069 @deftp {Data Type} bootloader-configuration
22070 The type of a bootloader configuration declaration.
22074 @item @code{bootloader}
22075 @cindex EFI, bootloader
22076 @cindex UEFI, bootloader
22077 @cindex BIOS, bootloader
22078 The bootloader to use, as a @code{bootloader} object. For now
22079 @code{grub-bootloader}, @code{grub-efi-bootloader},
22080 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
22082 @vindex grub-efi-bootloader
22083 @code{grub-efi-bootloader} allows to boot on modern systems using the
22084 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
22085 use if the installation image contains a @file{/sys/firmware/efi} directory
22086 when you boot it on your system.
22088 @vindex grub-bootloader
22089 @code{grub-bootloader} allows you to boot in particular Intel-based machines
22090 in ``legacy'' BIOS mode.
22092 @cindex ARM, bootloaders
22093 @cindex AArch64, bootloaders
22094 Available bootloaders are described in @code{(gnu bootloader @dots{})}
22095 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
22096 of bootloaders for a wide range of ARM and AArch64 systems, using the
22097 @uref{http://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
22099 @item @code{target}
22100 This is a string denoting the target onto which to install the
22103 The interpretation depends on the bootloader in question. For
22104 @code{grub-bootloader}, for example, it should be a device name understood by
22105 the bootloader @command{installer} command, such as @code{/dev/sda} or
22106 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
22107 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
22108 system, usually @file{/boot/efi}.
22110 @item @code{menu-entries} (default: @code{()})
22111 A possibly empty list of @code{menu-entry} objects (see below), denoting
22112 entries to appear in the bootloader menu, in addition to the current
22113 system entry and the entry pointing to previous system generations.
22115 @item @code{default-entry} (default: @code{0})
22116 The index of the default boot menu entry. Index 0 is for the entry of the
22119 @item @code{timeout} (default: @code{5})
22120 The number of seconds to wait for keyboard input before booting. Set to
22121 0 to boot immediately, and to -1 to wait indefinitely.
22123 @item @code{theme} (default: @var{#f})
22124 The bootloader theme object describing the theme to use. If no theme
22125 is provided, some bootloaders might use a default theme, that's true
22128 @item @code{terminal-outputs} (default: @code{'gfxterm})
22129 The output terminals used for the bootloader boot menu, as a list of
22130 symbols. GRUB accepts the values: @code{console}, @code{serial},
22131 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
22132 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
22133 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
22134 configuration,,, grub,GNU GRUB manual}).
22136 @item @code{terminal-inputs} (default: @code{'()})
22137 The input terminals used for the bootloader boot menu, as a list of
22138 symbols. For GRUB, the default is the native platform terminal as
22139 determined at run-time. GRUB accepts the values: @code{console},
22140 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
22141 @code{usb_keyboard}. This field corresponds to the GRUB variable
22142 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
22145 @item @code{serial-unit} (default: @code{#f})
22146 The serial unit used by the bootloader, as an integer from 0 to 3.
22147 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
22148 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
22150 @item @code{serial-speed} (default: @code{#f})
22151 The speed of the serial interface, as an integer. For GRUB, the
22152 default value is chosen at run-time; currently GRUB chooses
22153 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
22160 Should you want to list additional boot menu entries @i{via} the
22161 @code{menu-entries} field above, you will need to create them with the
22162 @code{menu-entry} form. For example, imagine you want to be able to
22163 boot another distro (hard to imagine!), you can define a menu entry
22168 (label "The Other Distro")
22169 (linux "/boot/old/vmlinux-2.6.32")
22170 (linux-arguments '("root=/dev/sda2"))
22171 (initrd "/boot/old/initrd"))
22176 @deftp {Data Type} menu-entry
22177 The type of an entry in the bootloader menu.
22182 The label to show in the menu---e.g., @code{"GNU"}.
22185 The Linux kernel image to boot, for example:
22188 (file-append linux-libre "/bzImage")
22191 For GRUB, it is also possible to specify a device explicitly in the
22192 file path using GRUB's device naming convention (@pxref{Naming
22193 convention,,, grub, GNU GRUB manual}), for example:
22196 "(hd0,msdos1)/boot/vmlinuz"
22199 If the device is specified explicitly as above, then the @code{device}
22200 field is ignored entirely.
22202 @item @code{linux-arguments} (default: @code{()})
22203 The list of extra Linux kernel command-line arguments---e.g.,
22204 @code{("console=ttyS0")}.
22206 @item @code{initrd}
22207 A G-Expression or string denoting the file name of the initial RAM disk
22208 to use (@pxref{G-Expressions}).
22209 @item @code{device} (default: @code{#f})
22210 The device where the kernel and initrd are to be found---i.e., for GRUB,
22211 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
22213 This may be a file system label (a string), a file system UUID (a
22214 bytevector, @pxref{File Systems}), or @code{#f}, in which case
22215 the bootloader will search the device containing the file specified by
22216 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
22217 must @emph{not} be an OS device name such as @file{/dev/sda1}.
22222 @c FIXME: Write documentation once it's stable.
22223 Fow now only GRUB has theme support. GRUB themes are created using
22224 the @code{grub-theme} form, which is not documented yet.
22226 @defvr {Scheme Variable} %default-theme
22227 This is the default GRUB theme used by the operating system if no
22228 @code{theme} field is specified in @code{bootloader-configuration}
22231 It comes with a fancy background image displaying the GNU and Guix
22236 @node Invoking guix system
22237 @subsection Invoking @code{guix system}
22239 Once you have written an operating system declaration as seen in the
22240 previous section, it can be @dfn{instantiated} using the @command{guix
22241 system} command. The synopsis is:
22244 guix system @var{options}@dots{} @var{action} @var{file}
22247 @var{file} must be the name of a file containing an
22248 @code{operating-system} declaration. @var{action} specifies how the
22249 operating system is instantiated. Currently the following values are
22254 Display available service type definitions that match the given regular
22255 expressions, sorted by relevance:
22258 $ guix system search console font
22259 name: console-fonts
22260 location: gnu/services/base.scm:729:2
22261 extends: shepherd-root
22262 description: Install the given fonts on the specified ttys (fonts are
22263 + per virtual console on GNU/Linux). The value of this service is a list
22264 + of tty/font pairs like:
22266 + '(("tty1" . "LatGrkCyr-8x16"))
22270 location: gnu/services/base.scm:1048:2
22271 extends: shepherd-root
22272 description: Provide console login using the `mingetty' program.
22276 location: gnu/services/base.scm:775:2
22278 description: Provide a console log-in service as specified by its
22279 + configuration value, a `login-configuration' object.
22285 As for @command{guix package --search}, the result is written in
22286 @code{recutils} format, which makes it easy to filter the output
22287 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
22290 Build the operating system described in @var{file}, activate it, and
22291 switch to it@footnote{This action (and the related actions
22292 @code{switch-generation} and @code{roll-back}) are usable only on
22293 systems already running GuixSD.}.
22295 This effects all the configuration specified in @var{file}: user
22296 accounts, system services, global package list, setuid programs, etc.
22297 The command starts system services specified in @var{file} that are not
22298 currently running; if a service is currently running this command will
22299 arrange for it to be upgraded the next time it is stopped (eg. by
22300 @code{herd stop X} or @code{herd restart X}).
22302 This command creates a new generation whose number is one greater than
22303 the current generation (as reported by @command{guix system
22304 list-generations}). If that generation already exists, it will be
22305 overwritten. This behavior mirrors that of @command{guix package}
22306 (@pxref{Invoking guix package}).
22308 It also adds a bootloader menu entry for the new OS configuration,
22309 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
22310 entries for older configurations to a submenu, allowing you to choose
22311 an older system generation at boot time should you need it.
22314 @c The paragraph below refers to the problem discussed at
22315 @c <http://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
22316 It is highly recommended to run @command{guix pull} once before you run
22317 @command{guix system reconfigure} for the first time (@pxref{Invoking
22318 guix pull}). Failing to do that you would see an older version of Guix
22319 once @command{reconfigure} has completed.
22322 @item switch-generation
22323 @cindex generations
22324 Switch to an existing system generation. This action atomically
22325 switches the system profile to the specified system generation. It
22326 also rearranges the system's existing bootloader menu entries. It
22327 makes the menu entry for the specified system generation the default,
22328 and it moves the entries for the other generatiors to a submenu, if
22329 supported by the bootloader being used. The next time the system
22330 boots, it will use the specified system generation.
22332 The bootloader itself is not being reinstalled when using this
22333 command. Thus, the installed bootloader is used with an updated
22334 configuration file.
22336 The target generation can be specified explicitly by its generation
22337 number. For example, the following invocation would switch to system
22341 guix system switch-generation 7
22344 The target generation can also be specified relative to the current
22345 generation with the form @code{+N} or @code{-N}, where @code{+3} means
22346 ``3 generations ahead of the current generation,'' and @code{-1} means
22347 ``1 generation prior to the current generation.'' When specifying a
22348 negative value such as @code{-1}, you must precede it with @code{--} to
22349 prevent it from being parsed as an option. For example:
22352 guix system switch-generation -- -1
22355 Currently, the effect of invoking this action is @emph{only} to switch
22356 the system profile to an existing generation and rearrange the
22357 bootloader menu entries. To actually start using the target system
22358 generation, you must reboot after running this action. In the future,
22359 it will be updated to do the same things as @command{reconfigure},
22360 like activating and deactivating services.
22362 This action will fail if the specified generation does not exist.
22365 @cindex rolling back
22366 Switch to the preceding system generation. The next time the system
22367 boots, it will use the preceding system generation. This is the inverse
22368 of @command{reconfigure}, and it is exactly the same as invoking
22369 @command{switch-generation} with an argument of @code{-1}.
22371 Currently, as with @command{switch-generation}, you must reboot after
22372 running this action to actually start using the preceding system
22376 Build the derivation of the operating system, which includes all the
22377 configuration files and programs needed to boot and run the system.
22378 This action does not actually install anything.
22381 Populate the given directory with all the files necessary to run the
22382 operating system specified in @var{file}. This is useful for first-time
22383 installations of GuixSD. For instance:
22386 guix system init my-os-config.scm /mnt
22389 copies to @file{/mnt} all the store items required by the configuration
22390 specified in @file{my-os-config.scm}. This includes configuration
22391 files, packages, and so on. It also creates other essential files
22392 needed for the system to operate correctly---e.g., the @file{/etc},
22393 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
22395 This command also installs bootloader on the target specified in
22396 @file{my-os-config}, unless the @option{--no-bootloader} option was
22400 @cindex virtual machine
22402 @anchor{guix system vm}
22403 Build a virtual machine that contains the operating system declared in
22404 @var{file}, and return a script to run that virtual machine (VM).
22405 Arguments given to the script are passed to QEMU as in the example
22406 below, which enables networking and requests 1@tie{}GiB of RAM for the
22410 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
22413 The VM shares its store with the host system.
22415 Additional file systems can be shared between the host and the VM using
22416 the @code{--share} and @code{--expose} command-line options: the former
22417 specifies a directory to be shared with write access, while the latter
22418 provides read-only access to the shared directory.
22420 The example below creates a VM in which the user's home directory is
22421 accessible read-only, and where the @file{/exchange} directory is a
22422 read-write mapping of @file{$HOME/tmp} on the host:
22425 guix system vm my-config.scm \
22426 --expose=$HOME --share=$HOME/tmp=/exchange
22429 On GNU/Linux, the default is to boot directly to the kernel; this has
22430 the advantage of requiring only a very tiny root disk image since the
22431 store of the host can then be mounted.
22433 The @code{--full-boot} option forces a complete boot sequence, starting
22434 with the bootloader. This requires more disk space since a root image
22435 containing at least the kernel, initrd, and bootloader data files must
22436 be created. The @code{--image-size} option can be used to specify the
22439 @cindex System images, creation in various formats
22440 @cindex Creating system images in various formats
22443 @itemx docker-image
22444 Return a virtual machine, disk image, or Docker image of the operating
22445 system declared in @var{file} that stands alone. By default,
22446 @command{guix system} estimates the size of the image needed to store
22447 the system, but you can use the @option{--image-size} option to specify
22448 a value. Docker images are built to contain exactly what they need, so
22449 the @option{--image-size} option is ignored in the case of
22450 @code{docker-image}.
22452 You can specify the root file system type by using the
22453 @option{--file-system-type} option. It defaults to @code{ext4}.
22455 When using @code{vm-image}, the returned image is in qcow2 format, which
22456 the QEMU emulator can efficiently use. @xref{Running GuixSD in a VM},
22457 for more information on how to run the image in a virtual machine.
22459 When using @code{disk-image}, a raw disk image is produced; it can be
22460 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
22461 the device corresponding to a USB stick, one can copy the image to it
22462 using the following command:
22465 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
22468 When using @code{docker-image}, a Docker image is produced. Guix builds
22469 the image from scratch, not from a pre-existing Docker base image. As a
22470 result, it contains @emph{exactly} what you define in the operating
22471 system configuration file. You can then load the image and launch a
22472 Docker container using commands like the following:
22475 image_id="$(docker load < guixsd-docker-image.tar.gz)"
22476 docker run -e GUIX_NEW_SYSTEM=/var/guix/profiles/system \\
22477 --entrypoint /var/guix/profiles/system/profile/bin/guile \\
22478 $image_id /var/guix/profiles/system/boot
22481 This command starts a new Docker container from the specified image. It
22482 will boot the GuixSD system in the usual manner, which means it will
22483 start any services you have defined in the operating system
22484 configuration. Depending on what you run in the Docker container, it
22485 may be necessary to give the container additional permissions. For
22486 example, if you intend to build software using Guix inside of the Docker
22487 container, you may need to pass the @option{--privileged} option to
22491 Return a script to run the operating system declared in @var{file}
22492 within a container. Containers are a set of lightweight isolation
22493 mechanisms provided by the kernel Linux-libre. Containers are
22494 substantially less resource-demanding than full virtual machines since
22495 the kernel, shared objects, and other resources can be shared with the
22496 host system; this also means they provide thinner isolation.
22498 Currently, the script must be run as root in order to support more than
22499 a single user and group. The container shares its store with the host
22502 As with the @code{vm} action (@pxref{guix system vm}), additional file
22503 systems to be shared between the host and container can be specified
22504 using the @option{--share} and @option{--expose} options:
22507 guix system container my-config.scm \
22508 --expose=$HOME --share=$HOME/tmp=/exchange
22512 This option requires Linux-libre 3.19 or newer.
22517 @var{options} can contain any of the common build options (@pxref{Common
22518 Build Options}). In addition, @var{options} can contain one of the
22522 @item --expression=@var{expr}
22523 @itemx -e @var{expr}
22524 Consider the operating-system @var{expr} evaluates to.
22525 This is an alternative to specifying a file which evaluates to an
22527 This is used to generate the GuixSD installer @pxref{Building the
22528 Installation Image}).
22530 @item --system=@var{system}
22531 @itemx -s @var{system}
22532 Attempt to build for @var{system} instead of the host system type.
22533 This works as per @command{guix build} (@pxref{Invoking guix build}).
22537 Return the derivation file name of the given operating system without
22540 @item --file-system-type=@var{type}
22541 @itemx -t @var{type}
22542 For the @code{disk-image} action, create a file system of the given
22543 @var{type} on the image.
22545 When this option is omitted, @command{guix system} uses @code{ext4}.
22547 @cindex ISO-9660 format
22548 @cindex CD image format
22549 @cindex DVD image format
22550 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
22551 for burning on CDs and DVDs.
22553 @item --image-size=@var{size}
22554 For the @code{vm-image} and @code{disk-image} actions, create an image
22555 of the given @var{size}. @var{size} may be a number of bytes, or it may
22556 include a unit as a suffix (@pxref{Block size, size specifications,,
22557 coreutils, GNU Coreutils}).
22559 When this option is omitted, @command{guix system} computes an estimate
22560 of the image size as a function of the size of the system declared in
22563 @item --root=@var{file}
22564 @itemx -r @var{file}
22565 Make @var{file} a symlink to the result, and register it as a garbage
22568 @item --skip-checks
22569 Skip pre-installation safety checks.
22571 By default, @command{guix system init} and @command{guix system
22572 reconfigure} perform safety checks: they make sure the file systems that
22573 appear in the @code{operating-system} declaration actually exist
22574 (@pxref{File Systems}), and that any Linux kernel modules that may be
22575 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
22576 RAM Disk}). Passing this option skips these tests altogether.
22578 @item --on-error=@var{strategy}
22579 Apply @var{strategy} when an error occurs when reading @var{file}.
22580 @var{strategy} may be one of the following:
22583 @item nothing-special
22584 Report the error concisely and exit. This is the default strategy.
22587 Likewise, but also display a backtrace.
22590 Report the error and enter Guile's debugger. From there, you can run
22591 commands such as @code{,bt} to get a backtrace, @code{,locals} to
22592 display local variable values, and more generally inspect the state of the
22593 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
22594 a list of available debugging commands.
22599 All the actions above, except @code{build} and @code{init},
22600 can use KVM support in the Linux-libre kernel. Specifically, if the
22601 machine has hardware virtualization support, the corresponding
22602 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
22603 must exist and be readable and writable by the user and by the
22604 build users of the daemon (@pxref{Build Environment Setup}).
22607 Once you have built, configured, re-configured, and re-re-configured
22608 your GuixSD installation, you may find it useful to list the operating
22609 system generations available on disk---and that you can choose from the
22610 bootloader boot menu:
22614 @item list-generations
22615 List a summary of each generation of the operating system available on
22616 disk, in a human-readable way. This is similar to the
22617 @option{--list-generations} option of @command{guix package}
22618 (@pxref{Invoking guix package}).
22620 Optionally, one can specify a pattern, with the same syntax that is used
22621 in @command{guix package --list-generations}, to restrict the list of
22622 generations displayed. For instance, the following command displays
22623 generations that are up to 10 days old:
22626 $ guix system list-generations 10d
22631 The @command{guix system} command has even more to offer! The following
22632 sub-commands allow you to visualize how your system services relate to
22635 @anchor{system-extension-graph}
22638 @item extension-graph
22639 Emit in Dot/Graphviz format to standard output the @dfn{service
22640 extension graph} of the operating system defined in @var{file}
22641 (@pxref{Service Composition}, for more information on service
22647 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
22650 produces a PDF file showing the extension relations among services.
22652 @anchor{system-shepherd-graph}
22653 @item shepherd-graph
22654 Emit in Dot/Graphviz format to standard output the @dfn{dependency
22655 graph} of shepherd services of the operating system defined in
22656 @var{file}. @xref{Shepherd Services}, for more information and for an
22661 @node Running GuixSD in a VM
22662 @subsection Running GuixSD in a Virtual Machine
22664 @cindex virtual machine
22665 To run GuixSD in a virtual machine (VM), one can either use the
22666 pre-built GuixSD VM image distributed at
22667 @indicateurl{https://alpha.gnu.org/gnu/guix/guixsd-vm-image-@value{VERSION}.@var{system}.xz}
22668 , or build their own virtual machine image using @command{guix system
22669 vm-image} (@pxref{Invoking guix system}). The returned image is in
22670 qcow2 format, which the @uref{http://qemu.org/, QEMU emulator} can
22674 If you built your own image, you must copy it out of the store
22675 (@pxref{The Store}) and give yourself permission to write to the copy
22676 before you can use it. When invoking QEMU, you must choose a system
22677 emulator that is suitable for your hardware platform. Here is a minimal
22678 QEMU invocation that will boot the result of @command{guix system
22679 vm-image} on x86_64 hardware:
22682 $ qemu-system-x86_64 \
22683 -net user -net nic,model=virtio \
22684 -enable-kvm -m 256 /tmp/qemu-image
22687 Here is what each of these options means:
22690 @item qemu-system-x86_64
22691 This specifies the hardware platform to emulate. This should match the
22695 Enable the unprivileged user-mode network stack. The guest OS can
22696 access the host but not vice versa. This is the simplest way to get the
22699 @item -net nic,model=virtio
22700 You must create a network interface of a given model. If you do not
22701 create a NIC, the boot will fail. Assuming your hardware platform is
22702 x86_64, you can get a list of available NIC models by running
22703 @command{qemu-system-x86_64 -net nic,model=help}.
22706 If your system has hardware virtualization extensions, enabling the
22707 virtual machine support (KVM) of the Linux kernel will make things run
22711 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
22712 which may be insufficient for some operations.
22714 @item /tmp/qemu-image
22715 The file name of the qcow2 image.
22718 The default @command{run-vm.sh} script that is returned by an invocation of
22719 @command{guix system vm} does not add a @command{-net user} flag by default.
22720 To get network access from within the vm add the @code{(dhcp-client-service)}
22721 to your system definition and start the VM using
22722 @command{`guix system vm config.scm` -net user}. An important caveat of using
22723 @command{-net user} for networking is that @command{ping} will not work, because
22724 it uses the ICMP protocol. You'll have to use a different command to check for
22725 network connectivity, for example @command{guix download}.
22727 @subsubsection Connecting Through SSH
22731 To enable SSH inside a VM you need to add a SSH server like @code{(dropbear-service)}
22732 or @code{(lsh-service)} to your VM. The @code{(lsh-service}) doesn't currently
22733 boot unsupervised. It requires you to type some characters to initialize the
22734 randomness generator. In addition you need to forward the SSH port, 22 by
22735 default, to the host. You can do this with
22738 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
22741 To connect to the VM you can run
22744 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
22747 The @command{-p} tells @command{ssh} the port you want to connect to.
22748 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
22749 every time you modify your @command{config.scm} file and the
22750 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
22751 connection to an unknown host every time you connect.
22753 @subsubsection Using @command{virt-viewer} with Spice
22755 As an alternative to the default @command{qemu} graphical client you can
22756 use the @command{remote-viewer} from the @command{virt-viewer} package. To
22757 connect pass the @command{-spice port=5930,disable-ticketing} flag to
22758 @command{qemu}. See previous section for further information on how to do this.
22760 Spice also allows you to do some nice stuff like share your clipboard with your
22761 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
22764 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
22765 -chardev spicevmc,name=vdagent,id=vdagent
22766 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
22767 name=com.redhat.spice.0
22770 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
22772 @node Defining Services
22773 @subsection Defining Services
22775 The previous sections show the available services and how one can combine
22776 them in an @code{operating-system} declaration. But how do we define
22777 them in the first place? And what is a service anyway?
22780 * Service Composition:: The model for composing services.
22781 * Service Types and Services:: Types and services.
22782 * Service Reference:: API reference.
22783 * Shepherd Services:: A particular type of service.
22786 @node Service Composition
22787 @subsubsection Service Composition
22791 Here we define a @dfn{service} as, broadly, something that extends the
22792 functionality of the operating system. Often a service is a process---a
22793 @dfn{daemon}---started when the system boots: a secure shell server, a
22794 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
22795 whose execution can be triggered by another daemon---e.g., an FTP server
22796 started by @command{inetd} or a D-Bus service activated by
22797 @command{dbus-daemon}. Occasionally, a service does not map to a
22798 daemon. For instance, the ``account'' service collects user accounts
22799 and makes sure they exist when the system runs; the ``udev'' service
22800 collects device management rules and makes them available to the eudev
22801 daemon; the @file{/etc} service populates the @file{/etc} directory
22804 @cindex service extensions
22805 GuixSD services are connected by @dfn{extensions}. For instance, the
22806 secure shell service @emph{extends} the Shepherd---the GuixSD
22807 initialization system, running as PID@tie{}1---by giving it the command
22808 lines to start and stop the secure shell daemon (@pxref{Networking
22809 Services, @code{lsh-service}}); the UPower service extends the D-Bus
22810 service by passing it its @file{.service} specification, and extends the
22811 udev service by passing it device management rules (@pxref{Desktop
22812 Services, @code{upower-service}}); the Guix daemon service extends the
22813 Shepherd by passing it the command lines to start and stop the daemon,
22814 and extends the account service by passing it a list of required build
22815 user accounts (@pxref{Base Services}).
22817 All in all, services and their ``extends'' relations form a directed
22818 acyclic graph (DAG). If we represent services as boxes and extensions
22819 as arrows, a typical system might provide something like this:
22821 @image{images/service-graph,,5in,Typical service extension graph.}
22823 @cindex system service
22824 At the bottom, we see the @dfn{system service}, which produces the
22825 directory containing everything to run and boot the system, as returned
22826 by the @command{guix system build} command. @xref{Service Reference},
22827 to learn about the other service types shown here.
22828 @xref{system-extension-graph, the @command{guix system extension-graph}
22829 command}, for information on how to generate this representation for a
22830 particular operating system definition.
22832 @cindex service types
22833 Technically, developers can define @dfn{service types} to express these
22834 relations. There can be any number of services of a given type on the
22835 system---for instance, a system running two instances of the GNU secure
22836 shell server (lsh) has two instances of @var{lsh-service-type}, with
22837 different parameters.
22839 The following section describes the programming interface for service
22840 types and services.
22842 @node Service Types and Services
22843 @subsubsection Service Types and Services
22845 A @dfn{service type} is a node in the DAG described above. Let us start
22846 with a simple example, the service type for the Guix build daemon
22847 (@pxref{Invoking guix-daemon}):
22850 (define guix-service-type
22854 (list (service-extension shepherd-root-service-type guix-shepherd-service)
22855 (service-extension account-service-type guix-accounts)
22856 (service-extension activation-service-type guix-activation)))
22857 (default-value (guix-configuration))))
22861 It defines three things:
22865 A name, whose sole purpose is to make inspection and debugging easier.
22868 A list of @dfn{service extensions}, where each extension designates the
22869 target service type and a procedure that, given the parameters of the
22870 service, returns a list of objects to extend the service of that type.
22872 Every service type has at least one service extension. The only
22873 exception is the @dfn{boot service type}, which is the ultimate service.
22876 Optionally, a default value for instances of this type.
22879 In this example, @var{guix-service-type} extends three services:
22882 @item shepherd-root-service-type
22883 The @var{guix-shepherd-service} procedure defines how the Shepherd
22884 service is extended. Namely, it returns a @code{<shepherd-service>}
22885 object that defines how @command{guix-daemon} is started and stopped
22886 (@pxref{Shepherd Services}).
22888 @item account-service-type
22889 This extension for this service is computed by @var{guix-accounts},
22890 which returns a list of @code{user-group} and @code{user-account}
22891 objects representing the build user accounts (@pxref{Invoking
22894 @item activation-service-type
22895 Here @var{guix-activation} is a procedure that returns a gexp, which is
22896 a code snippet to run at ``activation time''---e.g., when the service is
22900 A service of this type is instantiated like this:
22903 (service guix-service-type
22904 (guix-configuration
22906 (use-substitutes? #f)))
22909 The second argument to the @code{service} form is a value representing
22910 the parameters of this specific service instance.
22911 @xref{guix-configuration-type, @code{guix-configuration}}, for
22912 information about the @code{guix-configuration} data type. When the
22913 value is omitted, the default value specified by
22914 @code{guix-service-type} is used:
22917 (service guix-service-type)
22920 @var{guix-service-type} is quite simple because it extends other
22921 services but is not extensible itself.
22923 @c @subsubsubsection Extensible Service Types
22925 The service type for an @emph{extensible} service looks like this:
22928 (define udev-service-type
22929 (service-type (name 'udev)
22931 (list (service-extension shepherd-root-service-type
22932 udev-shepherd-service)))
22934 (compose concatenate) ;concatenate the list of rules
22935 (extend (lambda (config rules)
22937 (($ <udev-configuration> udev initial-rules)
22938 (udev-configuration
22939 (udev udev) ;the udev package to use
22940 (rules (append initial-rules rules)))))))))
22943 This is the service type for the
22944 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
22945 management daemon}. Compared to the previous example, in addition to an
22946 extension of @var{shepherd-root-service-type}, we see two new fields:
22950 This is the procedure to @dfn{compose} the list of extensions to
22951 services of this type.
22953 Services can extend the udev service by passing it lists of rules; we
22954 compose those extensions simply by concatenating them.
22957 This procedure defines how the value of the service is @dfn{extended} with
22958 the composition of the extensions.
22960 Udev extensions are composed into a list of rules, but the udev service
22961 value is itself a @code{<udev-configuration>} record. So here, we
22962 extend that record by appending the list of rules it contains to the
22963 list of contributed rules.
22966 This is a string giving an overview of the service type. The string can
22967 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
22968 @command{guix system search} command searches these strings and displays
22969 them (@pxref{Invoking guix system}).
22972 There can be only one instance of an extensible service type such as
22973 @var{udev-service-type}. If there were more, the
22974 @code{service-extension} specifications would be ambiguous.
22976 Still here? The next section provides a reference of the programming
22977 interface for services.
22979 @node Service Reference
22980 @subsubsection Service Reference
22982 We have seen an overview of service types (@pxref{Service Types and
22983 Services}). This section provides a reference on how to manipulate
22984 services and service types. This interface is provided by the
22985 @code{(gnu services)} module.
22987 @deffn {Scheme Procedure} service @var{type} [@var{value}]
22988 Return a new service of @var{type}, a @code{<service-type>} object (see
22989 below.) @var{value} can be any object; it represents the parameters of
22990 this particular service instance.
22992 When @var{value} is omitted, the default value specified by @var{type}
22993 is used; if @var{type} does not specify a default value, an error is
22996 For instance, this:
22999 (service openssh-service-type)
23003 is equivalent to this:
23006 (service openssh-service-type
23007 (openssh-configuration))
23010 In both cases the result is an instance of @code{openssh-service-type}
23011 with the default configuration.
23014 @deffn {Scheme Procedure} service? @var{obj}
23015 Return true if @var{obj} is a service.
23018 @deffn {Scheme Procedure} service-kind @var{service}
23019 Return the type of @var{service}---i.e., a @code{<service-type>} object.
23022 @deffn {Scheme Procedure} service-value @var{service}
23023 Return the value associated with @var{service}. It represents its
23027 Here is an example of how a service is created and manipulated:
23031 (service nginx-service-type
23032 (nginx-configuration
23034 (log-directory log-directory)
23035 (run-directory run-directory)
23036 (file config-file))))
23041 (eq? (service-kind s) nginx-service-type)
23045 The @code{modify-services} form provides a handy way to change the
23046 parameters of some of the services of a list such as
23047 @var{%base-services} (@pxref{Base Services, @code{%base-services}}). It
23048 evaluates to a list of services. Of course, you could always use
23049 standard list combinators such as @code{map} and @code{fold} to do that
23050 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
23051 @code{modify-services} simply provides a more concise form for this
23054 @deffn {Scheme Syntax} modify-services @var{services} @
23055 (@var{type} @var{variable} => @var{body}) @dots{}
23057 Modify the services listed in @var{services} according to the given
23058 clauses. Each clause has the form:
23061 (@var{type} @var{variable} => @var{body})
23064 where @var{type} is a service type---e.g.,
23065 @code{guix-service-type}---and @var{variable} is an identifier that is
23066 bound within the @var{body} to the service parameters---e.g., a
23067 @code{guix-configuration} instance---of the original service of that
23070 The @var{body} should evaluate to the new service parameters, which will
23071 be used to configure the new service. This new service will replace the
23072 original in the resulting list. Because a service's service parameters
23073 are created using @code{define-record-type*}, you can write a succinct
23074 @var{body} that evaluates to the new service parameters by using the
23075 @code{inherit} feature that @code{define-record-type*} provides.
23077 @xref{Using the Configuration System}, for example usage.
23081 Next comes the programming interface for service types. This is
23082 something you want to know when writing new service definitions, but not
23083 necessarily when simply looking for ways to customize your
23084 @code{operating-system} declaration.
23086 @deftp {Data Type} service-type
23087 @cindex service type
23088 This is the representation of a @dfn{service type} (@pxref{Service Types
23093 This is a symbol, used only to simplify inspection and debugging.
23095 @item @code{extensions}
23096 A non-empty list of @code{<service-extension>} objects (see below).
23098 @item @code{compose} (default: @code{#f})
23099 If this is @code{#f}, then the service type denotes services that cannot
23100 be extended---i.e., services that do not receive ``values'' from other
23103 Otherwise, it must be a one-argument procedure. The procedure is called
23104 by @code{fold-services} and is passed a list of values collected from
23105 extensions. It may return any single value.
23107 @item @code{extend} (default: @code{#f})
23108 If this is @code{#f}, services of this type cannot be extended.
23110 Otherwise, it must be a two-argument procedure: @code{fold-services}
23111 calls it, passing it the initial value of the service as the first
23112 argument and the result of applying @code{compose} to the extension
23113 values as the second argument. It must return a value that is a valid
23114 parameter value for the service instance.
23117 @xref{Service Types and Services}, for examples.
23120 @deffn {Scheme Procedure} service-extension @var{target-type} @
23122 Return a new extension for services of type @var{target-type}.
23123 @var{compute} must be a one-argument procedure: @code{fold-services}
23124 calls it, passing it the value associated with the service that provides
23125 the extension; it must return a valid value for the target service.
23128 @deffn {Scheme Procedure} service-extension? @var{obj}
23129 Return true if @var{obj} is a service extension.
23132 Occasionally, you might want to simply extend an existing service. This
23133 involves creating a new service type and specifying the extension of
23134 interest, which can be verbose; the @code{simple-service} procedure
23135 provides a shorthand for this.
23137 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
23138 Return a service that extends @var{target} with @var{value}. This works
23139 by creating a singleton service type @var{name}, of which the returned
23140 service is an instance.
23142 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
23146 (simple-service 'my-mcron-job mcron-service-type
23147 #~(job '(next-hour (3)) "guix gc -F 2G"))
23151 At the core of the service abstraction lies the @code{fold-services}
23152 procedure, which is responsible for ``compiling'' a list of services
23153 down to a single directory that contains everything needed to boot and
23154 run the system---the directory shown by the @command{guix system build}
23155 command (@pxref{Invoking guix system}). In essence, it propagates
23156 service extensions down the service graph, updating each node parameters
23157 on the way, until it reaches the root node.
23159 @deffn {Scheme Procedure} fold-services @var{services} @
23160 [#:target-type @var{system-service-type}]
23161 Fold @var{services} by propagating their extensions down to the root of
23162 type @var{target-type}; return the root service adjusted accordingly.
23165 Lastly, the @code{(gnu services)} module also defines several essential
23166 service types, some of which are listed below.
23168 @defvr {Scheme Variable} system-service-type
23169 This is the root of the service graph. It produces the system directory
23170 as returned by the @command{guix system build} command.
23173 @defvr {Scheme Variable} boot-service-type
23174 The type of the ``boot service'', which produces the @dfn{boot script}.
23175 The boot script is what the initial RAM disk runs when booting.
23178 @defvr {Scheme Variable} etc-service-type
23179 The type of the @file{/etc} service. This service is used to create
23180 files under @file{/etc} and can be extended by
23181 passing it name/file tuples such as:
23184 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
23187 In this example, the effect would be to add an @file{/etc/issue} file
23188 pointing to the given file.
23191 @defvr {Scheme Variable} setuid-program-service-type
23192 Type for the ``setuid-program service''. This service collects lists of
23193 executable file names, passed as gexps, and adds them to the set of
23194 setuid-root programs on the system (@pxref{Setuid Programs}).
23197 @defvr {Scheme Variable} profile-service-type
23198 Type of the service that populates the @dfn{system profile}---i.e., the
23199 programs under @file{/run/current-system/profile}. Other services can
23200 extend it by passing it lists of packages to add to the system profile.
23204 @node Shepherd Services
23205 @subsubsection Shepherd Services
23207 @cindex shepherd services
23209 @cindex init system
23210 The @code{(gnu services shepherd)} module provides a way to define
23211 services managed by the GNU@tie{}Shepherd, which is the GuixSD
23212 initialization system---the first process that is started when the
23213 system boots, also known as PID@tie{}1
23214 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
23216 Services in the Shepherd can depend on each other. For instance, the
23217 SSH daemon may need to be started after the syslog daemon has been
23218 started, which in turn can only happen once all the file systems have
23219 been mounted. The simple operating system defined earlier (@pxref{Using
23220 the Configuration System}) results in a service graph like this:
23222 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
23224 You can actually generate such a graph for any operating system
23225 definition using the @command{guix system shepherd-graph} command
23226 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
23228 The @var{%shepherd-root-service} is a service object representing
23229 PID@tie{}1, of type @var{shepherd-root-service-type}; it can be extended
23230 by passing it lists of @code{<shepherd-service>} objects.
23232 @deftp {Data Type} shepherd-service
23233 The data type representing a service managed by the Shepherd.
23236 @item @code{provision}
23237 This is a list of symbols denoting what the service provides.
23239 These are the names that may be passed to @command{herd start},
23240 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
23241 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
23242 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
23244 @item @code{requirements} (default: @code{'()})
23245 List of symbols denoting the Shepherd services this one depends on.
23247 @item @code{respawn?} (default: @code{#t})
23248 Whether to restart the service when it stops, for instance when the
23249 underlying process dies.
23252 @itemx @code{stop} (default: @code{#~(const #f)})
23253 The @code{start} and @code{stop} fields refer to the Shepherd's
23254 facilities to start and stop processes (@pxref{Service De- and
23255 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
23256 G-expressions that get expanded in the Shepherd configuration file
23257 (@pxref{G-Expressions}).
23259 @item @code{actions} (default: @code{'()})
23260 @cindex actions, of Shepherd services
23261 This is a list of @code{shepherd-action} objects (see below) defining
23262 @dfn{actions} supported by the service, in addition to the standard
23263 @code{start} and @code{stop} actions. Actions listed here become available as
23264 @command{herd} sub-commands:
23267 herd @var{action} @var{service} [@var{arguments}@dots{}]
23270 @item @code{documentation}
23271 A documentation string, as shown when running:
23274 herd doc @var{service-name}
23277 where @var{service-name} is one of the symbols in @var{provision}
23278 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
23280 @item @code{modules} (default: @var{%default-modules})
23281 This is the list of modules that must be in scope when @code{start} and
23282 @code{stop} are evaluated.
23287 @deftp {Data Type} shepherd-action
23288 This is the data type that defines additional actions implemented by a
23289 Shepherd service (see above).
23293 Symbol naming the action.
23295 @item documentation
23296 This is a documentation string for the action. It can be viewed by running:
23299 herd doc @var{service} action @var{action}
23303 This should be a gexp that evaluates to a procedure of at least one argument,
23304 which is the ``running value'' of the service (@pxref{Slots of services,,,
23305 shepherd, The GNU Shepherd Manual}).
23308 The following example defines an action called @code{say-hello} that kindly
23314 (documentation "Say hi!")
23315 (procedure #~(lambda (running . args)
23316 (format #t "Hello, friend! arguments: ~s\n"
23321 Assuming this action is added to the @code{example} service, then you can do:
23324 # herd say-hello example
23325 Hello, friend! arguments: ()
23326 # herd say-hello example a b c
23327 Hello, friend! arguments: ("a" "b" "c")
23330 This, as you can see, is a fairly sophisticated way to say hello.
23331 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
23335 @defvr {Scheme Variable} shepherd-root-service-type
23336 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
23338 This is the service type that extensions target when they want to create
23339 shepherd services (@pxref{Service Types and Services}, for an example).
23340 Each extension must pass a list of @code{<shepherd-service>}.
23343 @defvr {Scheme Variable} %shepherd-root-service
23344 This service represents PID@tie{}1.
23348 @node Documentation
23349 @section Documentation
23351 @cindex documentation, searching for
23352 @cindex searching for documentation
23353 @cindex Info, documentation format
23355 @cindex manual pages
23356 In most cases packages installed with Guix come with documentation.
23357 There are two main documentation formats: ``Info'', a browseable
23358 hypertext format used for GNU software, and ``manual pages'' (or ``man
23359 pages''), the linear documentation format traditionally found on Unix.
23360 Info manuals are accessed with the @command{info} command or with Emacs,
23361 and man pages are accessed using @command{man}.
23363 You can look for documentation of software installed on your system by
23364 keyword. For example, the following command searches for information
23365 about ``TLS'' in Info manuals:
23369 "(emacs)Network Security" -- STARTTLS
23370 "(emacs)Network Security" -- TLS
23371 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
23372 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
23377 The command below searches for the same keyword in man pages:
23381 SSL (7) - OpenSSL SSL/TLS library
23382 certtool (1) - GnuTLS certificate tool
23386 These searches are purely local to your computer so you have the
23387 guarantee that documentation you find corresponds to what you have
23388 actually installed, you can access it off-line, and your privacy is
23391 Once you have these results, you can view the relevant documentation by
23395 $ info "(gnutls)Core TLS API"
23405 Info manuals contain sections and indices as well as hyperlinks like
23406 those found in Web pages. The @command{info} reader (@pxref{Top, Info
23407 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
23408 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
23409 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
23410 Introduction}, for an introduction to Info navigation.
23412 @node Installing Debugging Files
23413 @section Installing Debugging Files
23415 @cindex debugging files
23416 Program binaries, as produced by the GCC compilers for instance, are
23417 typically written in the ELF format, with a section containing
23418 @dfn{debugging information}. Debugging information is what allows the
23419 debugger, GDB, to map binary code to source code; it is required to
23420 debug a compiled program in good conditions.
23422 The problem with debugging information is that is takes up a fair amount
23423 of disk space. For example, debugging information for the GNU C Library
23424 weighs in at more than 60 MiB. Thus, as a user, keeping all the
23425 debugging info of all the installed programs is usually not an option.
23426 Yet, space savings should not come at the cost of an impediment to
23427 debugging---especially in the GNU system, which should make it easier
23428 for users to exert their computing freedom (@pxref{GNU Distribution}).
23430 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
23431 mechanism that allows users to get the best of both worlds: debugging
23432 information can be stripped from the binaries and stored in separate
23433 files. GDB is then able to load debugging information from those files,
23434 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
23437 The GNU distribution takes advantage of this by storing debugging
23438 information in the @code{lib/debug} sub-directory of a separate package
23439 output unimaginatively called @code{debug} (@pxref{Packages with
23440 Multiple Outputs}). Users can choose to install the @code{debug} output
23441 of a package when they need it. For instance, the following command
23442 installs the debugging information for the GNU C Library and for GNU
23446 guix package -i glibc:debug guile:debug
23449 GDB must then be told to look for debug files in the user's profile, by
23450 setting the @code{debug-file-directory} variable (consider setting it
23451 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
23455 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
23458 From there on, GDB will pick up debugging information from the
23459 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
23461 In addition, you will most likely want GDB to be able to show the source
23462 code being debugged. To do that, you will have to unpack the source
23463 code of the package of interest (obtained with @code{guix build
23464 --source}, @pxref{Invoking guix build}), and to point GDB to that source
23465 directory using the @code{directory} command (@pxref{Source Path,
23466 @code{directory},, gdb, Debugging with GDB}).
23468 @c XXX: keep me up-to-date
23469 The @code{debug} output mechanism in Guix is implemented by the
23470 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
23471 opt-in---debugging information is available only for the packages
23472 with definitions explicitly declaring a @code{debug} output. This may be
23473 changed to opt-out in the future if our build farm servers can handle
23474 the load. To check whether a package has a @code{debug} output, use
23475 @command{guix package --list-available} (@pxref{Invoking guix package}).
23478 @node Security Updates
23479 @section Security Updates
23481 @cindex security updates
23482 @cindex security vulnerabilities
23483 Occasionally, important security vulnerabilities are discovered in software
23484 packages and must be patched. Guix developers try hard to keep track of
23485 known vulnerabilities and to apply fixes as soon as possible in the
23486 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
23487 containing only security updates.) The @command{guix lint} tool helps
23488 developers find out about vulnerable versions of software packages in the
23493 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
23494 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
23495 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
23499 @xref{Invoking guix lint}, for more information.
23502 As of version @value{VERSION}, the feature described below is considered
23506 Guix follows a functional
23507 package management discipline (@pxref{Introduction}), which implies
23508 that, when a package is changed, @emph{every package that depends on it}
23509 must be rebuilt. This can significantly slow down the deployment of
23510 fixes in core packages such as libc or Bash, since basically the whole
23511 distribution would need to be rebuilt. Using pre-built binaries helps
23512 (@pxref{Substitutes}), but deployment may still take more time than
23516 To address this, Guix implements @dfn{grafts}, a mechanism that allows
23517 for fast deployment of critical updates without the costs associated
23518 with a whole-distribution rebuild. The idea is to rebuild only the
23519 package that needs to be patched, and then to ``graft'' it onto packages
23520 explicitly installed by the user and that were previously referring to
23521 the original package. The cost of grafting is typically very low, and
23522 order of magnitudes lower than a full rebuild of the dependency chain.
23524 @cindex replacements of packages, for grafts
23525 For instance, suppose a security update needs to be applied to Bash.
23526 Guix developers will provide a package definition for the ``fixed''
23527 Bash, say @var{bash-fixed}, in the usual way (@pxref{Defining
23528 Packages}). Then, the original package definition is augmented with a
23529 @code{replacement} field pointing to the package containing the bug fix:
23536 (replacement bash-fixed)))
23539 From there on, any package depending directly or indirectly on Bash---as
23540 reported by @command{guix gc --requisites} (@pxref{Invoking guix
23541 gc})---that is installed is automatically ``rewritten'' to refer to
23542 @var{bash-fixed} instead of @var{bash}. This grafting process takes
23543 time proportional to the size of the package, usually less than a
23544 minute for an ``average'' package on a recent machine. Grafting is
23545 recursive: when an indirect dependency requires grafting, then grafting
23546 ``propagates'' up to the package that the user is installing.
23548 Currently, the length of the name and version of the graft and that of
23549 the package it replaces (@var{bash-fixed} and @var{bash} in the example
23550 above) must be equal. This restriction mostly comes from the fact that
23551 grafting works by patching files, including binary files, directly.
23552 Other restrictions may apply: for instance, when adding a graft to a
23553 package providing a shared library, the original shared library and its
23554 replacement must have the same @code{SONAME} and be binary-compatible.
23556 The @option{--no-grafts} command-line option allows you to forcefully
23557 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
23561 guix build bash --no-grafts
23565 returns the store file name of the original Bash, whereas:
23572 returns the store file name of the ``fixed'', replacement Bash. This
23573 allows you to distinguish between the two variants of Bash.
23575 To verify which Bash your whole profile refers to, you can run
23576 (@pxref{Invoking guix gc}):
23579 guix gc -R `readlink -f ~/.guix-profile` | grep bash
23583 @dots{} and compare the store file names that you get with those above.
23584 Likewise for a complete GuixSD system generation:
23587 guix gc -R `guix system build my-config.scm` | grep bash
23590 Lastly, to check which Bash running processes are using, you can use the
23591 @command{lsof} command:
23594 lsof | grep /gnu/store/.*bash
23598 @node Package Modules
23599 @section Package Modules
23601 From a programming viewpoint, the package definitions of the
23602 GNU distribution are provided by Guile modules in the @code{(gnu packages
23603 @dots{})} name space@footnote{Note that packages under the @code{(gnu
23604 packages @dots{})} module name space are not necessarily ``GNU
23605 packages''. This module naming scheme follows the usual Guile module
23606 naming convention: @code{gnu} means that these modules are distributed
23607 as part of the GNU system, and @code{packages} identifies modules that
23608 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
23609 Reference Manual}). For instance, the @code{(gnu packages emacs)}
23610 module exports a variable named @code{emacs}, which is bound to a
23611 @code{<package>} object (@pxref{Defining Packages}).
23613 The @code{(gnu packages @dots{})} module name space is
23614 automatically scanned for packages by the command-line tools. For
23615 instance, when running @code{guix package -i emacs}, all the @code{(gnu
23616 packages @dots{})} modules are scanned until one that exports a package
23617 object whose name is @code{emacs} is found. This package search
23618 facility is implemented in the @code{(gnu packages)} module.
23620 @cindex customization, of packages
23621 @cindex package module search path
23622 Users can store package definitions in modules with different
23623 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
23624 name and module name must match. For instance, the @code{(my-packages
23625 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
23626 relative to the load path specified with @option{--load-path} or
23627 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
23628 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
23629 these package definitions visible to the user interfaces:
23633 By adding the directory containing your package modules to the search path
23634 with the @code{-L} flag of @command{guix package} and other commands
23635 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
23636 environment variable described below.
23639 By defining a @dfn{channel} and configuring @command{guix pull} so that it
23640 pulls from it. A channel is essentially a Git repository containing package
23641 modules. @xref{Channels}, for more information on how to define and use
23645 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
23647 @defvr {Environment Variable} GUIX_PACKAGE_PATH
23648 This is a colon-separated list of directories to search for additional
23649 package modules. Directories listed in this variable take precedence
23650 over the own modules of the distribution.
23653 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
23654 each package is built based solely on other packages in the
23655 distribution. The root of this dependency graph is a small set of
23656 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
23657 bootstrap)} module. For more information on bootstrapping,
23658 @pxref{Bootstrapping}.
23660 @node Packaging Guidelines
23661 @section Packaging Guidelines
23663 @cindex packages, creating
23664 The GNU distribution is nascent and may well lack some of your favorite
23665 packages. This section describes how you can help make the distribution
23666 grow. @xref{Contributing}, for additional information on how you can
23669 Free software packages are usually distributed in the form of
23670 @dfn{source code tarballs}---typically @file{tar.gz} files that contain
23671 all the source files. Adding a package to the distribution means
23672 essentially two things: adding a @dfn{recipe} that describes how to
23673 build the package, including a list of other packages required to build
23674 it, and adding @dfn{package metadata} along with that recipe, such as a
23675 description and licensing information.
23677 In Guix all this information is embodied in @dfn{package definitions}.
23678 Package definitions provide a high-level view of the package. They are
23679 written using the syntax of the Scheme programming language; in fact,
23680 for each package we define a variable bound to the package definition,
23681 and export that variable from a module (@pxref{Package Modules}).
23682 However, in-depth Scheme knowledge is @emph{not} a prerequisite for
23683 creating packages. For more information on package definitions,
23684 @pxref{Defining Packages}.
23686 Once a package definition is in place, stored in a file in the Guix
23687 source tree, it can be tested using the @command{guix build} command
23688 (@pxref{Invoking guix build}). For example, assuming the new package is
23689 called @code{gnew}, you may run this command from the Guix build tree
23690 (@pxref{Running Guix Before It Is Installed}):
23693 ./pre-inst-env guix build gnew --keep-failed
23696 Using @code{--keep-failed} makes it easier to debug build failures since
23697 it provides access to the failed build tree. Another useful
23698 command-line option when debugging is @code{--log-file}, to access the
23701 If the package is unknown to the @command{guix} command, it may be that
23702 the source file contains a syntax error, or lacks a @code{define-public}
23703 clause to export the package variable. To figure it out, you may load
23704 the module from Guile to get more information about the actual error:
23707 ./pre-inst-env guile -c '(use-modules (gnu packages gnew))'
23710 Once your package builds correctly, please send us a patch
23711 (@pxref{Contributing}). Well, if you need help, we will be happy to
23712 help you too. Once the patch is committed in the Guix repository, the
23713 new package automatically gets built on the supported platforms by
23714 @url{http://hydra.gnu.org/jobset/gnu/master, our continuous integration
23717 @cindex substituter
23718 Users can obtain the new package definition simply by running
23719 @command{guix pull} (@pxref{Invoking guix pull}). When
23720 @code{hydra.gnu.org} is done building the package, installing the
23721 package automatically downloads binaries from there
23722 (@pxref{Substitutes}). The only place where human intervention is
23723 needed is to review and apply the patch.
23727 * Software Freedom:: What may go into the distribution.
23728 * Package Naming:: What's in a name?
23729 * Version Numbers:: When the name is not enough.
23730 * Synopses and Descriptions:: Helping users find the right package.
23731 * Python Modules:: A touch of British comedy.
23732 * Perl Modules:: Little pearls.
23733 * Java Packages:: Coffee break.
23734 * Fonts:: Fond of fonts.
23737 @node Software Freedom
23738 @subsection Software Freedom
23740 @c Adapted from http://www.gnu.org/philosophy/philosophy.html.
23741 @cindex free software
23742 The GNU operating system has been developed so that users can have
23743 freedom in their computing. GNU is @dfn{free software}, meaning that
23744 users have the @url{http://www.gnu.org/philosophy/free-sw.html,four
23745 essential freedoms}: to run the program, to study and change the program
23746 in source code form, to redistribute exact copies, and to distribute
23747 modified versions. Packages found in the GNU distribution provide only
23748 software that conveys these four freedoms.
23750 In addition, the GNU distribution follow the
23751 @url{http://www.gnu.org/distros/free-system-distribution-guidelines.html,free
23752 software distribution guidelines}. Among other things, these guidelines
23753 reject non-free firmware, recommendations of non-free software, and
23754 discuss ways to deal with trademarks and patents.
23756 Some otherwise free upstream package sources contain a small and optional
23757 subset that violates the above guidelines, for instance because this subset
23758 is itself non-free code. When that happens, the offending items are removed
23759 with appropriate patches or code snippets in the @code{origin} form of the
23760 package (@pxref{Defining Packages}). This way, @code{guix
23761 build --source} returns the ``freed'' source rather than the unmodified
23765 @node Package Naming
23766 @subsection Package Naming
23768 @cindex package name
23769 A package has actually two names associated with it:
23770 First, there is the name of the @emph{Scheme variable}, the one following
23771 @code{define-public}. By this name, the package can be made known in the
23772 Scheme code, for instance as input to another package. Second, there is
23773 the string in the @code{name} field of a package definition. This name
23774 is used by package management commands such as
23775 @command{guix package} and @command{guix build}.
23777 Both are usually the same and correspond to the lowercase conversion of
23778 the project name chosen upstream, with underscores replaced with
23779 hyphens. For instance, GNUnet is available as @code{gnunet}, and
23780 SDL_net as @code{sdl-net}.
23782 We do not add @code{lib} prefixes for library packages, unless these are
23783 already part of the official project name. But @pxref{Python
23784 Modules} and @ref{Perl Modules} for special rules concerning modules for
23785 the Python and Perl languages.
23787 Font package names are handled differently, @pxref{Fonts}.
23790 @node Version Numbers
23791 @subsection Version Numbers
23793 @cindex package version
23794 We usually package only the latest version of a given free software
23795 project. But sometimes, for instance for incompatible library versions,
23796 two (or more) versions of the same package are needed. These require
23797 different Scheme variable names. We use the name as defined
23798 in @ref{Package Naming}
23799 for the most recent version; previous versions use the same name, suffixed
23800 by @code{-} and the smallest prefix of the version number that may
23801 distinguish the two versions.
23803 The name inside the package definition is the same for all versions of a
23804 package and does not contain any version number.
23806 For instance, the versions 2.24.20 and 3.9.12 of GTK+ may be packaged as follows:
23809 (define-public gtk+
23814 (define-public gtk+-2
23817 (version "2.24.20")
23820 If we also wanted GTK+ 3.8.2, this would be packaged as
23822 (define-public gtk+-3.8
23829 @c See <https://lists.gnu.org/archive/html/guix-devel/2016-01/msg00425.html>,
23830 @c for a discussion of what follows.
23831 @cindex version number, for VCS snapshots
23832 Occasionally, we package snapshots of upstream's version control system
23833 (VCS) instead of formal releases. This should remain exceptional,
23834 because it is up to upstream developers to clarify what the stable
23835 release is. Yet, it is sometimes necessary. So, what should we put in
23836 the @code{version} field?
23838 Clearly, we need to make the commit identifier of the VCS snapshot
23839 visible in the version string, but we also need to make sure that the
23840 version string is monotonically increasing so that @command{guix package
23841 --upgrade} can determine which version is newer. Since commit
23842 identifiers, notably with Git, are not monotonically increasing, we add
23843 a revision number that we increase each time we upgrade to a newer
23844 snapshot. The resulting version string looks like this:
23849 | | `-- upstream commit ID
23851 | `--- Guix package revision
23853 latest upstream version
23856 It is a good idea to strip commit identifiers in the @code{version}
23857 field to, say, 7 digits. It avoids an aesthetic annoyance (assuming
23858 aesthetics have a role to play here) as well as problems related to OS
23859 limits such as the maximum shebang length (127 bytes for the Linux
23860 kernel.) It is best to use the full commit identifiers in
23861 @code{origin}s, though, to avoid ambiguities. A typical package
23862 definition may look like this:
23866 (let ((commit "c3f29bc928d5900971f65965feaae59e1272a3f7")
23867 (revision "1")) ;Guix package revision
23869 (version (git-version "0.9" revision commit))
23872 (uri (git-reference
23873 (url "git://example.org/my-package.git")
23875 (sha256 (base32 "1mbikn@dots{}"))
23876 (file-name (git-file-name name version))))
23881 @node Synopses and Descriptions
23882 @subsection Synopses and Descriptions
23884 @cindex package description
23885 @cindex package synopsis
23886 As we have seen before, each package in GNU@tie{}Guix includes a
23887 synopsis and a description (@pxref{Defining Packages}). Synopses and
23888 descriptions are important: They are what @command{guix package
23889 --search} searches, and a crucial piece of information to help users
23890 determine whether a given package suits their needs. Consequently,
23891 packagers should pay attention to what goes into them.
23893 Synopses must start with a capital letter and must not end with a
23894 period. They must not start with ``a'' or ``the'', which usually does
23895 not bring anything; for instance, prefer ``File-frobbing tool'' over ``A
23896 tool that frobs files''. The synopsis should say what the package
23897 is---e.g., ``Core GNU utilities (file, text, shell)''---or what it is
23898 used for---e.g., the synopsis for GNU@tie{}grep is ``Print lines
23899 matching a pattern''.
23901 Keep in mind that the synopsis must be meaningful for a very wide
23902 audience. For example, ``Manipulate alignments in the SAM format''
23903 might make sense for a seasoned bioinformatics researcher, but might be
23904 fairly unhelpful or even misleading to a non-specialized audience. It
23905 is a good idea to come up with a synopsis that gives an idea of the
23906 application domain of the package. In this example, this might give
23907 something like ``Manipulate nucleotide sequence alignments'', which
23908 hopefully gives the user a better idea of whether this is what they are
23911 Descriptions should take between five and ten lines. Use full
23912 sentences, and avoid using acronyms without first introducing them.
23913 Please avoid marketing phrases such as ``world-leading'',
23914 ``industrial-strength'', and ``next-generation'', and avoid superlatives
23915 like ``the most advanced''---they are not helpful to users looking for a
23916 package and may even sound suspicious. Instead, try to be factual,
23917 mentioning use cases and features.
23919 @cindex Texinfo markup, in package descriptions
23920 Descriptions can include Texinfo markup, which is useful to introduce
23921 ornaments such as @code{@@code} or @code{@@dfn}, bullet lists, or
23922 hyperlinks (@pxref{Overview,,, texinfo, GNU Texinfo}). However you
23923 should be careful when using some characters for example @samp{@@} and
23924 curly braces which are the basic special characters in Texinfo
23925 (@pxref{Special Characters,,, texinfo, GNU Texinfo}). User interfaces
23926 such as @command{guix package --show} take care of rendering it
23929 Synopses and descriptions are translated by volunteers
23930 @uref{http://translationproject.org/domain/guix-packages.html, at the
23931 Translation Project} so that as many users as possible can read them in
23932 their native language. User interfaces search them and display them in
23933 the language specified by the current locale.
23935 To allow @command{xgettext} to extract them as translatable strings,
23936 synopses and descriptions @emph{must be literal strings}. This means
23937 that you cannot use @code{string-append} or @code{format} to construct
23943 (synopsis "This is translatable")
23944 (description (string-append "This is " "*not*" " translatable.")))
23947 Translation is a lot of work so, as a packager, please pay even more
23948 attention to your synopses and descriptions as every change may entail
23949 additional work for translators. In order to help them, it is possible
23950 to make recommendations or instructions visible to them by inserting
23951 special comments like this (@pxref{xgettext Invocation,,, gettext, GNU
23955 ;; TRANSLATORS: "X11 resize-and-rotate" should not be translated.
23956 (description "ARandR is designed to provide a simple visual front end
23957 for the X11 resize-and-rotate (RandR) extension. @dots{}")
23961 @node Python Modules
23962 @subsection Python Modules
23965 We currently package Python 2 and Python 3, under the Scheme variable names
23966 @code{python-2} and @code{python} as explained in @ref{Version Numbers}.
23967 To avoid confusion and naming clashes with other programming languages, it
23968 seems desirable that the name of a package for a Python module contains
23969 the word @code{python}.
23971 Some modules are compatible with only one version of Python, others with both.
23972 If the package Foo compiles only with Python 3, we name it
23973 @code{python-foo}; if it compiles only with Python 2, we name it
23974 @code{python2-foo}. If it is compatible with both versions, we create two
23975 packages with the corresponding names.
23977 If a project already contains the word @code{python}, we drop this;
23978 for instance, the module python-dateutil is packaged under the names
23979 @code{python-dateutil} and @code{python2-dateutil}. If the project name
23980 starts with @code{py} (e.g. @code{pytz}), we keep it and prefix it as
23983 @subsubsection Specifying Dependencies
23984 @cindex inputs, for Python packages
23986 Dependency information for Python packages is usually available in the
23987 package source tree, with varying degrees of accuracy: in the
23988 @file{setup.py} file, in @file{requirements.txt}, or in @file{tox.ini}.
23990 Your mission, when writing a recipe for a Python package, is to map
23991 these dependencies to the appropriate type of ``input'' (@pxref{package
23992 Reference, inputs}). Although the @code{pypi} importer normally does a
23993 good job (@pxref{Invoking guix import}), you may want to check the
23994 following check list to determine which dependency goes where.
23999 We currently package Python 2 with @code{setuptools} and @code{pip}
24000 installed like Python 3.4 has per default. Thus you don't need to
24001 specify either of these as an input. @command{guix lint} will warn you
24005 Python dependencies required at run time go into
24006 @code{propagated-inputs}. They are typically defined with the
24007 @code{install_requires} keyword in @file{setup.py}, or in the
24008 @file{requirements.txt} file.
24011 Python packages required only at build time---e.g., those listed with
24012 the @code{setup_requires} keyword in @file{setup.py}---or only for
24013 testing---e.g., those in @code{tests_require}---go into
24014 @code{native-inputs}. The rationale is that (1) they do not need to be
24015 propagated because they are not needed at run time, and (2) in a
24016 cross-compilation context, it's the ``native'' input that we'd want.
24018 Examples are the @code{pytest}, @code{mock}, and @code{nose} test
24019 frameworks. Of course if any of these packages is also required at
24020 run-time, it needs to go to @code{propagated-inputs}.
24023 Anything that does not fall in the previous categories goes to
24024 @code{inputs}, for example programs or C libraries required for building
24025 Python packages containing C extensions.
24028 If a Python package has optional dependencies (@code{extras_require}),
24029 it is up to you to decide whether to add them or not, based on their
24030 usefulness/overhead ratio (@pxref{Submitting Patches, @command{guix
24037 @subsection Perl Modules
24040 Perl programs standing for themselves are named as any other package,
24041 using the lowercase upstream name.
24042 For Perl packages containing a single class, we use the lowercase class name,
24043 replace all occurrences of @code{::} by dashes and prepend the prefix
24045 So the class @code{XML::Parser} becomes @code{perl-xml-parser}.
24046 Modules containing several classes keep their lowercase upstream name and
24047 are also prepended by @code{perl-}. Such modules tend to have the word
24048 @code{perl} somewhere in their name, which gets dropped in favor of the
24049 prefix. For instance, @code{libwww-perl} becomes @code{perl-libwww}.
24052 @node Java Packages
24053 @subsection Java Packages
24056 Java programs standing for themselves are named as any other package,
24057 using the lowercase upstream name.
24059 To avoid confusion and naming clashes with other programming languages,
24060 it is desirable that the name of a package for a Java package is
24061 prefixed with @code{java-}. If a project already contains the word
24062 @code{java}, we drop this; for instance, the package @code{ngsjava} is
24063 packaged under the name @code{java-ngs}.
24065 For Java packages containing a single class or a small class hierarchy,
24066 we use the lowercase class name, replace all occurrences of @code{.} by
24067 dashes and prepend the prefix @code{java-}. So the class
24068 @code{apache.commons.cli} becomes package
24069 @code{java-apache-commons-cli}.
24076 For fonts that are in general not installed by a user for typesetting
24077 purposes, or that are distributed as part of a larger software package,
24078 we rely on the general packaging rules for software; for instance, this
24079 applies to the fonts delivered as part of the X.Org system or fonts that
24080 are part of TeX Live.
24082 To make it easier for a user to search for fonts, names for other packages
24083 containing only fonts are constructed as follows, independently of the
24084 upstream package name.
24086 The name of a package containing only one font family starts with
24087 @code{font-}; it is followed by the foundry name and a dash @code{-}
24088 if the foundry is known, and the font family name, in which spaces are
24089 replaced by dashes (and as usual, all upper case letters are transformed
24091 For example, the Gentium font family by SIL is packaged under the name
24092 @code{font-sil-gentium}.
24094 For a package containing several font families, the name of the collection
24095 is used in the place of the font family name.
24096 For instance, the Liberation fonts consist of three families,
24097 Liberation Sans, Liberation Serif and Liberation Mono.
24098 These could be packaged separately under the names
24099 @code{font-liberation-sans} and so on; but as they are distributed together
24100 under a common name, we prefer to package them together as
24101 @code{font-liberation}.
24103 In the case where several formats of the same font family or font collection
24104 are packaged separately, a short form of the format, prepended by a dash,
24105 is added to the package name. We use @code{-ttf} for TrueType fonts,
24106 @code{-otf} for OpenType fonts and @code{-type1} for PostScript Type 1
24111 @node Bootstrapping
24112 @section Bootstrapping
24114 @c Adapted from the ELS 2013 paper.
24116 @cindex bootstrapping
24118 Bootstrapping in our context refers to how the distribution gets built
24119 ``from nothing''. Remember that the build environment of a derivation
24120 contains nothing but its declared inputs (@pxref{Introduction}). So
24121 there's an obvious chicken-and-egg problem: how does the first package
24122 get built? How does the first compiler get compiled? Note that this is
24123 a question of interest only to the curious hacker, not to the regular
24124 user, so you can shamelessly skip this section if you consider yourself
24125 a ``regular user''.
24127 @cindex bootstrap binaries
24128 The GNU system is primarily made of C code, with libc at its core. The
24129 GNU build system itself assumes the availability of a Bourne shell and
24130 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
24131 `grep'. Furthermore, build programs---programs that run
24132 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
24133 (@pxref{Derivations}). Consequently, to be able to build anything at
24134 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
24135 Binutils, libc, and the other packages mentioned above---the
24136 @dfn{bootstrap binaries}.
24138 These bootstrap binaries are ``taken for granted'', though we can also
24139 re-create them if needed (more on that later).
24141 @unnumberedsubsec Preparing to Use the Bootstrap Binaries
24143 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
24144 @c large image, it's hard to scroll. Oh well.
24145 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
24147 The figure above shows the very beginning of the dependency graph of the
24148 distribution, corresponding to the package definitions of the @code{(gnu
24149 packages bootstrap)} module. A similar figure can be generated with
24150 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
24153 guix graph -t derivation \
24154 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
24158 At this level of detail, things are
24159 slightly complex. First, Guile itself consists of an ELF executable,
24160 along with many source and compiled Scheme files that are dynamically
24161 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
24162 tarball shown in this graph. This tarball is part of Guix's ``source''
24163 distribution, and gets inserted into the store with @code{add-to-store}
24164 (@pxref{The Store}).
24166 But how do we write a derivation that unpacks this tarball and adds it
24167 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
24168 derivation---the first one that gets built---uses @code{bash} as its
24169 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
24170 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
24171 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
24172 the Guix source distribution, whose sole purpose is to allow the Guile
24173 tarball to be unpacked.
24175 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
24176 Guile that can be used to run subsequent build programs. Its first task
24177 is to download tarballs containing the other pre-built binaries---this
24178 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
24179 @code{ftp-client.scm} are used for this purpose. The
24180 @code{module-import.drv} derivations import those modules in a directory
24181 in the store, using the original layout. The
24182 @code{module-import-compiled.drv} derivations compile those modules, and
24183 write them in an output directory with the right layout. This
24184 corresponds to the @code{#:modules} argument of
24185 @code{build-expression->derivation} (@pxref{Derivations}).
24187 Finally, the various tarballs are unpacked by the
24188 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
24189 etc., at which point we have a working C tool chain.
24192 @unnumberedsubsec Building the Build Tools
24194 Bootstrapping is complete when we have a full tool chain that does not
24195 depend on the pre-built bootstrap tools discussed above. This
24196 no-dependency requirement is verified by checking whether the files of
24197 the final tool chain contain references to the @file{/gnu/store}
24198 directories of the bootstrap inputs. The process that leads to this
24199 ``final'' tool chain is described by the package definitions found in
24200 the @code{(gnu packages commencement)} module.
24202 The @command{guix graph} command allows us to ``zoom out'' compared to
24203 the graph above, by looking at the level of package objects instead of
24204 individual derivations---remember that a package may translate to
24205 several derivations, typically one derivation to download its source,
24206 one to build the Guile modules it needs, and one to actually build the
24207 package from source. The command:
24210 guix graph -t bag \
24211 -e '(@@@@ (gnu packages commencement)
24212 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
24216 produces the dependency graph leading to the ``final'' C
24217 library@footnote{You may notice the @code{glibc-intermediate} label,
24218 suggesting that it is not @emph{quite} final, but as a good
24219 approximation, we will consider it final.}, depicted below.
24221 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
24223 @c See <http://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
24224 The first tool that gets built with the bootstrap binaries is
24225 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
24226 for all the following packages. From there Findutils and Diffutils get
24229 Then come the first-stage Binutils and GCC, built as pseudo cross
24230 tools---i.e., with @code{--target} equal to @code{--host}. They are
24231 used to build libc. Thanks to this cross-build trick, this libc is
24232 guaranteed not to hold any reference to the initial tool chain.
24234 From there the final Binutils and GCC (not shown above) are built.
24236 from the final Binutils, and links programs against the just-built libc.
24237 This tool chain is used to build the other packages used by Guix and by
24238 the GNU Build System: Guile, Bash, Coreutils, etc.
24240 And voilà! At this point we have the complete set of build tools that
24241 the GNU Build System expects. These are in the @code{%final-inputs}
24242 variable of the @code{(gnu packages commencement)} module, and are
24243 implicitly used by any package that uses @code{gnu-build-system}
24244 (@pxref{Build Systems, @code{gnu-build-system}}).
24247 @unnumberedsubsec Building the Bootstrap Binaries
24249 @cindex bootstrap binaries
24250 Because the final tool chain does not depend on the bootstrap binaries,
24251 those rarely need to be updated. Nevertheless, it is useful to have an
24252 automated way to produce them, should an update occur, and this is what
24253 the @code{(gnu packages make-bootstrap)} module provides.
24255 The following command builds the tarballs containing the bootstrap
24256 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
24257 of Coreutils and other basic command-line tools):
24260 guix build bootstrap-tarballs
24263 The generated tarballs are those that should be referred to in the
24264 @code{(gnu packages bootstrap)} module mentioned at the beginning of
24267 Still here? Then perhaps by now you've started to wonder: when do we
24268 reach a fixed point? That is an interesting question! The answer is
24269 unknown, but if you would like to investigate further (and have
24270 significant computational and storage resources to do so), then let us
24273 @unnumberedsubsec Reducing the Set of Bootstrap Binaries
24275 Our bootstrap binaries currently include GCC, Guile, etc. That's a lot
24276 of binary code! Why is that a problem? It's a problem because these
24277 big chunks of binary code are practically non-auditable, which makes it
24278 hard to establish what source code produced them. Every unauditable
24279 binary also leaves us vulnerable to compiler backdoors as described by
24280 Ken Thompson in the 1984 paper @emph{Reflections on Trusting Trust}.
24282 This is mitigated by the fact that our bootstrap binaries were generated
24283 from an earlier Guix revision. Nevertheless it lacks the level of
24284 transparency that we get in the rest of the package dependency graph,
24285 where Guix always gives us a source-to-binary mapping. Thus, our goal
24286 is to reduce the set of bootstrap binaries to the bare minimum.
24288 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
24289 on-going projects to do that. One of these is about replacing the
24290 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
24291 of increasing complexity, which could be built from source starting from
24292 a simple and auditable assembler. Your help is welcome!
24296 @section Porting to a New Platform
24298 As discussed above, the GNU distribution is self-contained, and
24299 self-containment is achieved by relying on pre-built ``bootstrap
24300 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
24301 operating system kernel, CPU architecture, and application binary
24302 interface (ABI). Thus, to port the distribution to a platform that is
24303 not yet supported, one must build those bootstrap binaries, and update
24304 the @code{(gnu packages bootstrap)} module to use them on that platform.
24306 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
24307 When everything goes well, and assuming the GNU tool chain supports the
24308 target platform, this can be as simple as running a command like this
24312 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
24315 For this to work, the @code{glibc-dynamic-linker} procedure in
24316 @code{(gnu packages bootstrap)} must be augmented to return the right
24317 file name for libc's dynamic linker on that platform; likewise,
24318 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
24319 taught about the new platform.
24321 Once these are built, the @code{(gnu packages bootstrap)} module needs
24322 to be updated to refer to these binaries on the target platform. That
24323 is, the hashes and URLs of the bootstrap tarballs for the new platform
24324 must be added alongside those of the currently supported platforms. The
24325 bootstrap Guile tarball is treated specially: it is expected to be
24326 available locally, and @file{gnu/local.mk} has rules to download it for
24327 the supported architectures; a rule for the new platform must be added
24330 In practice, there may be some complications. First, it may be that the
24331 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
24332 above) is not recognized by all the GNU tools. Typically, glibc
24333 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
24334 configure flag (see @code{gcc.scm} for examples of how to handle this).
24335 Second, some of the required packages could fail to build for that
24336 platform. Lastly, the generated binaries could be broken for some
24339 @c *********************************************************************
24340 @include contributing.texi
24342 @c *********************************************************************
24343 @node Acknowledgments
24344 @chapter Acknowledgments
24346 Guix is based on the @uref{http://nixos.org/nix/, Nix package manager},
24347 which was designed and
24348 implemented by Eelco Dolstra, with contributions from other people (see
24349 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
24350 management, and promoted unprecedented features, such as transactional
24351 package upgrades and rollbacks, per-user profiles, and referentially
24352 transparent build processes. Without this work, Guix would not exist.
24354 The Nix-based software distributions, Nixpkgs and NixOS, have also been
24355 an inspiration for Guix.
24357 GNU@tie{}Guix itself is a collective work with contributions from a
24358 number of people. See the @file{AUTHORS} file in Guix for more
24359 information on these fine people. The @file{THANKS} file lists people
24360 who have helped by reporting bugs, taking care of the infrastructure,
24361 providing artwork and themes, making suggestions, and more---thank you!
24364 @c *********************************************************************
24365 @node GNU Free Documentation License
24366 @appendix GNU Free Documentation License
24367 @cindex license, GNU Free Documentation License
24368 @include fdl-1.3.texi
24370 @c *********************************************************************
24371 @node Concept Index
24372 @unnumbered Concept Index
24375 @node Programming Index
24376 @unnumbered Programming Index
24377 @syncodeindex tp fn
24378 @syncodeindex vr fn
24383 @c Local Variables:
24384 @c ispell-local-dictionary: "american";