6 @documentencoding UTF-8
7 @settitle GNU Guix Reference Manual
12 @c Identifier of the OpenPGP key used to sign tarballs and such.
13 @set OPENPGP-SIGNING-KEY-ID 3CE464558A84FDC69DB40CFB090B11993D9AEBB5
14 @set KEY-SERVER pool.sks-keyservers.net
16 @c The official substitute server used by default.
17 @set SUBSTITUTE-SERVER ci.guix.info
20 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 Ludovic Courtès@*
21 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
22 Copyright @copyright{} 2013 Nikita Karetnikov@*
23 Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
24 Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
25 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
26 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
27 Copyright @copyright{} 2015, 2016, 2017 Leo Famulari@*
28 Copyright @copyright{} 2015, 2016, 2017, 2018, 2019 Ricardo Wurmus@*
29 Copyright @copyright{} 2016 Ben Woodcroft@*
30 Copyright @copyright{} 2016, 2017, 2018 Chris Marusich@*
31 Copyright @copyright{} 2016, 2017, 2018 Efraim Flashner@*
32 Copyright @copyright{} 2016 John Darrington@*
33 Copyright @copyright{} 2016, 2017 Nils Gillmann@*
34 Copyright @copyright{} 2016, 2017, 2018 Jan Nieuwenhuizen@*
35 Copyright @copyright{} 2016 Julien Lepiller@*
36 Copyright @copyright{} 2016 Alex ter Weele@*
37 Copyright @copyright{} 2017, 2018 Clément Lassieur@*
38 Copyright @copyright{} 2017, 2018 Mathieu Othacehe@*
39 Copyright @copyright{} 2017 Federico Beffa@*
40 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
41 Copyright @copyright{} 2017 Thomas Danckaert@*
42 Copyright @copyright{} 2017 humanitiesNerd@*
43 Copyright @copyright{} 2017 Christopher Allan Webber@*
44 Copyright @copyright{} 2017, 2018 Marius Bakke@*
45 Copyright @copyright{} 2017 Hartmut Goebel@*
46 Copyright @copyright{} 2017 Maxim Cournoyer@*
47 Copyright @copyright{} 2017, 2018 Tobias Geerinckx-Rice@*
48 Copyright @copyright{} 2017 George Clemmer@*
49 Copyright @copyright{} 2017 Andy Wingo@*
50 Copyright @copyright{} 2017, 2018 Arun Isaac@*
51 Copyright @copyright{} 2017 nee@*
52 Copyright @copyright{} 2018 Rutger Helling@*
53 Copyright @copyright{} 2018 Oleg Pykhalov@*
54 Copyright @copyright{} 2018 Mike Gerwitz@*
55 Copyright @copyright{} 2018 Pierre-Antoine Rouby@*
56 Copyright @copyright{} 2018 Gábor Boskovits@*
57 Copyright @copyright{} 2018 Florian Pelz@*
58 Copyright @copyright{} 2018 Laura Lazzati@*
59 Copyright @copyright{} 2018 Alex Vong@*
61 Permission is granted to copy, distribute and/or modify this document
62 under the terms of the GNU Free Documentation License, Version 1.3 or
63 any later version published by the Free Software Foundation; with no
64 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
65 copy of the license is included in the section entitled ``GNU Free
66 Documentation License''.
69 @dircategory System administration
71 * Guix: (guix). Manage installed software and system configuration.
72 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
73 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
74 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
75 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
78 @dircategory Software development
80 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
81 * guix build: (guix)Invoking guix build. Building packages.
82 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
86 @title GNU Guix Reference Manual
87 @subtitle Using the GNU Guix Functional Package Manager
88 @author The GNU Guix Developers
91 @vskip 0pt plus 1filll
92 Edition @value{EDITION} @*
100 @c *********************************************************************
104 This document describes GNU Guix version @value{VERSION}, a functional
105 package management tool written for the GNU system.
107 @c TRANSLATORS: You can replace the following paragraph with information on
108 @c how to join your own translation team and how to report issues with the
110 This manual is also available in French (@pxref{Top,,, guix.fr, Manuel de
111 référence de GNU Guix}) and German (@pxref{Top,,, guix.de, Referenzhandbuch
112 zu GNU Guix}). If you would like to translate it in your native language,
114 @uref{https://translationproject.org/domain/guix-manual.html, Translation
118 * Introduction:: What is Guix about?
119 * Installation:: Installing Guix.
120 * Package Management:: Package installation, upgrade, etc.
121 * Programming Interface:: Using Guix in Scheme.
122 * Utilities:: Package management commands.
123 * System Installation:: Installing the whole operating system.
124 * System Configuration:: Configuring the operating system.
125 * Documentation:: Browsing software user manuals.
126 * Installing Debugging Files:: Feeding the debugger.
127 * Security Updates:: Deploying security fixes quickly.
128 * Package Modules:: Packages from the programmer's viewpoint.
129 * Packaging Guidelines:: Growing the distribution.
130 * Bootstrapping:: GNU/Linux built from scratch.
131 * Porting:: Targeting another platform or kernel.
132 * Contributing:: Your help needed!
134 * Acknowledgments:: Thanks!
135 * GNU Free Documentation License:: The license of this manual.
136 * Concept Index:: Concepts.
137 * Programming Index:: Data types, functions, and variables.
140 --- The Detailed Node Listing ---
144 * Binary Installation:: Getting Guix running in no time!
145 * Requirements:: Software needed to build and run Guix.
146 * Running the Test Suite:: Testing Guix.
147 * Setting Up the Daemon:: Preparing the build daemon's environment.
148 * Invoking guix-daemon:: Running the build daemon.
149 * Application Setup:: Application-specific setup.
151 Setting Up the Daemon
153 * Build Environment Setup:: Preparing the isolated build environment.
154 * Daemon Offload Setup:: Offloading builds to remote machines.
155 * SELinux Support:: Using an SELinux policy for the daemon.
159 * Features:: How Guix will make your life brighter.
160 * Invoking guix package:: Package installation, removal, etc.
161 * Substitutes:: Downloading pre-built binaries.
162 * Packages with Multiple Outputs:: Single source package, multiple outputs.
163 * Invoking guix gc:: Running the garbage collector.
164 * Invoking guix pull:: Fetching the latest Guix and distribution.
165 * Channels:: Customizing the package collection.
166 * Inferiors:: Interacting with another revision of Guix.
167 * Invoking guix describe:: Display information about your Guix revision.
168 * Invoking guix pack:: Creating software bundles.
169 * Invoking guix archive:: Exporting and importing store files.
173 * Official Substitute Server:: One particular source of substitutes.
174 * Substitute Server Authorization:: How to enable or disable substitutes.
175 * Substitute Authentication:: How Guix verifies substitutes.
176 * Proxy Settings:: How to get substitutes via proxy.
177 * Substitution Failure:: What happens when substitution fails.
178 * On Trusting Binaries:: How can you trust that binary blob?
180 Programming Interface
182 * Defining Packages:: Defining new packages.
183 * Build Systems:: Specifying how packages are built.
184 * The Store:: Manipulating the package store.
185 * Derivations:: Low-level interface to package derivations.
186 * The Store Monad:: Purely functional interface to the store.
187 * G-Expressions:: Manipulating build expressions.
188 * Invoking guix repl:: Fiddling with Guix interactively.
192 * package Reference:: The package data type.
193 * origin Reference:: The origin data type.
197 * Invoking guix build:: Building packages from the command line.
198 * Invoking guix edit:: Editing package definitions.
199 * Invoking guix download:: Downloading a file and printing its hash.
200 * Invoking guix hash:: Computing the cryptographic hash of a file.
201 * Invoking guix import:: Importing package definitions.
202 * Invoking guix refresh:: Updating package definitions.
203 * Invoking guix lint:: Finding errors in package definitions.
204 * Invoking guix size:: Profiling disk usage.
205 * Invoking guix graph:: Visualizing the graph of packages.
206 * Invoking guix environment:: Setting up development environments.
207 * Invoking guix publish:: Sharing substitutes.
208 * Invoking guix challenge:: Challenging substitute servers.
209 * Invoking guix copy:: Copying to and from a remote store.
210 * Invoking guix container:: Process isolation.
211 * Invoking guix weather:: Assessing substitute availability.
212 * Invoking guix processes:: Listing client processes.
214 Invoking @command{guix build}
216 * Common Build Options:: Build options for most commands.
217 * Package Transformation Options:: Creating variants of packages.
218 * Additional Build Options:: Options specific to 'guix build'.
219 * Debugging Build Failures:: Real life packaging experience.
223 * Limitations:: What you can expect.
224 * Hardware Considerations:: Supported hardware.
225 * USB Stick and DVD Installation:: Preparing the installation medium.
226 * Preparing for Installation:: Networking, partitioning, etc.
227 * Proceeding with the Installation:: The real thing.
228 * Installing GuixSD in a VM:: GuixSD playground.
229 * Building the Installation Image:: How this comes to be.
233 * Using the Configuration System:: Customizing your GNU system.
234 * operating-system Reference:: Detail of operating-system declarations.
235 * File Systems:: Configuring file system mounts.
236 * Mapped Devices:: Block device extra processing.
237 * User Accounts:: Specifying user accounts.
238 * Locales:: Language and cultural convention settings.
239 * Services:: Specifying system services.
240 * Setuid Programs:: Programs running with root privileges.
241 * X.509 Certificates:: Authenticating HTTPS servers.
242 * Name Service Switch:: Configuring libc's name service switch.
243 * Initial RAM Disk:: Linux-Libre bootstrapping.
244 * Bootloader Configuration:: Configuring the boot loader.
245 * Invoking guix system:: Instantiating a system configuration.
246 * Running GuixSD in a VM:: How to run GuixSD in a virtual machine.
247 * Defining Services:: Adding new service definitions.
251 * Base Services:: Essential system services.
252 * Scheduled Job Execution:: The mcron service.
253 * Log Rotation:: The rottlog service.
254 * Networking Services:: Network setup, SSH daemon, etc.
255 * X Window:: Graphical display.
256 * Printing Services:: Local and remote printer support.
257 * Desktop Services:: D-Bus and desktop services.
258 * Sound Services:: ALSA and Pulseaudio services.
259 * Database Services:: SQL databases, key-value stores, etc.
260 * Mail Services:: IMAP, POP3, SMTP, and all that.
261 * Messaging Services:: Messaging services.
262 * Telephony Services:: Telephony services.
263 * Monitoring Services:: Monitoring services.
264 * Kerberos Services:: Kerberos services.
265 * Web Services:: Web servers.
266 * Certificate Services:: TLS certificates via Let's Encrypt.
267 * DNS Services:: DNS daemons.
268 * VPN Services:: VPN daemons.
269 * Network File System:: NFS related services.
270 * Continuous Integration:: The Cuirass service.
271 * Power Management Services:: Extending battery life.
272 * Audio Services:: The MPD.
273 * Virtualization Services:: Virtualization services.
274 * Version Control Services:: Providing remote access to Git repositories.
275 * Game Services:: Game servers.
276 * Miscellaneous Services:: Other services.
280 * Service Composition:: The model for composing services.
281 * Service Types and Services:: Types and services.
282 * Service Reference:: API reference.
283 * Shepherd Services:: A particular type of service.
287 * Software Freedom:: What may go into the distribution.
288 * Package Naming:: What's in a name?
289 * Version Numbers:: When the name is not enough.
290 * Synopses and Descriptions:: Helping users find the right package.
291 * Python Modules:: A touch of British comedy.
292 * Perl Modules:: Little pearls.
293 * Java Packages:: Coffee break.
294 * Fonts:: Fond of fonts.
299 @c *********************************************************************
301 @chapter Introduction
304 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
305 using the international phonetic alphabet (IPA).} is a package
306 management tool for and distribution of the GNU system.
307 Guix makes it easy for unprivileged
308 users to install, upgrade, or remove software packages, to roll back to a
309 previous package set, to build packages from source, and generally
310 assists with the creation and maintenance of software environments.
314 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
315 complements the available tools without interference (@pxref{Installation}),
316 or you can use it as a standalone operating system distribution,
317 @dfn{Guix@tie{}System} (@pxref{GNU Distribution}).
319 @node Managing Software the Guix Way
320 @section Managing Software the Guix Way
322 @cindex user interfaces
323 Guix provides a command-line package management interface
324 (@pxref{Invoking guix package}), a set of command-line utilities
325 (@pxref{Utilities}), as well as Scheme programming interfaces
326 (@pxref{Programming Interface}).
328 Its @dfn{build daemon} is responsible for building packages on behalf of
329 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
330 binaries from authorized sources (@pxref{Substitutes}).
332 @cindex extensibility of the distribution
333 @cindex customization, of packages
334 Guix includes package definitions for many GNU and non-GNU packages, all
335 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
336 user's computing freedom}. It is @emph{extensible}: users can write
337 their own package definitions (@pxref{Defining Packages}) and make them
338 available as independent package modules (@pxref{Package Modules}). It
339 is also @emph{customizable}: users can @emph{derive} specialized package
340 definitions from existing ones, including from the command line
341 (@pxref{Package Transformation Options}).
343 @cindex functional package management
345 Under the hood, Guix implements the @dfn{functional package management}
346 discipline pioneered by Nix (@pxref{Acknowledgments}).
347 In Guix, the package build and installation process is seen
348 as a @emph{function}, in the mathematical sense. That function takes inputs,
349 such as build scripts, a compiler, and libraries, and
350 returns an installed package. As a pure function, its result depends
351 solely on its inputs---for instance, it cannot refer to software or
352 scripts that were not explicitly passed as inputs. A build function
353 always produces the same result when passed a given set of inputs. It
354 cannot alter the environment of the running system in
355 any way; for instance, it cannot create, modify, or delete files outside
356 of its build and installation directories. This is achieved by running
357 build processes in isolated environments (or @dfn{containers}), where only their
358 explicit inputs are visible.
361 The result of package build functions is @dfn{cached} in the file
362 system, in a special directory called @dfn{the store} (@pxref{The
363 Store}). Each package is installed in a directory of its own in the
364 store---by default under @file{/gnu/store}. The directory name contains
365 a hash of all the inputs used to build that package; thus, changing an
366 input yields a different directory name.
368 This approach is the foundation for the salient features of Guix: support
369 for transactional package upgrade and rollback, per-user installation, and
370 garbage collection of packages (@pxref{Features}).
373 @node GNU Distribution
374 @section GNU Distribution
378 Guix comes with a distribution of the GNU system consisting entirely of
379 free software@footnote{The term ``free'' here refers to the
380 @url{http://www.gnu.org/philosophy/free-sw.html,freedom provided to
381 users of that software}.}. The
382 distribution can be installed on its own (@pxref{System Installation}),
383 but it is also possible to install Guix as a package manager on top of
384 an installed GNU/Linux system (@pxref{Installation}). When we need to
385 distinguish between the two, we refer to the standalone distribution as
388 The distribution provides core GNU packages such as GNU libc, GCC, and
389 Binutils, as well as many GNU and non-GNU applications. The complete
390 list of available packages can be browsed
391 @url{http://www.gnu.org/software/guix/packages,on-line} or by
392 running @command{guix package} (@pxref{Invoking guix package}):
395 guix package --list-available
398 Our goal is to provide a practical 100% free software distribution of
399 Linux-based and other variants of GNU, with a focus on the promotion and
400 tight integration of GNU components, and an emphasis on programs and
401 tools that help users exert that freedom.
403 Packages are currently available on the following platforms:
408 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
411 Intel 32-bit architecture (IA32), Linux-Libre kernel;
414 ARMv7-A architecture with hard float, Thumb-2 and NEON,
415 using the EABI hard-float application binary interface (ABI),
416 and Linux-Libre kernel.
419 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel. This is
420 currently in an experimental stage, with limited support.
421 @xref{Contributing}, for how to help!
424 little-endian 64-bit MIPS processors, specifically the Loongson series,
425 n32 ABI, and Linux-Libre kernel.
429 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
430 configuration and Guix takes care of instantiating the configuration in a
431 transactional, reproducible, and stateless fashion (@pxref{System
432 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
433 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
434 Manual}), the well-known GNU utilities and tool chain, as well as the
435 graphical environment or system services of your choice.
437 Guix System is available on all the above platforms except
438 @code{mips64el-linux}.
441 For information on porting to other architectures or kernels,
444 Building this distribution is a cooperative effort, and you are invited
445 to join! @xref{Contributing}, for information about how you can help.
448 @c *********************************************************************
450 @chapter Installation
452 @cindex installing Guix
455 We recommend the use of this
456 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
457 shell installer script} to install Guix on top of a running GNU/Linux system,
458 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
459 with the installation of the package manager, which can be done on top of a
460 running GNU/Linux system. If, instead, you want to install the complete GNU
461 operating system, @pxref{System Installation}.} The script automates the
462 download, installation, and initial configuration of Guix. It should be run
466 @cindex foreign distro
467 @cindex directories related to foreign distro
468 When installed on a foreign distro, GNU@tie{}Guix complements the available
469 tools without interference. Its data lives exclusively in two directories,
470 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
471 such as @file{/etc}, are left untouched.
473 Once installed, Guix can be updated by running @command{guix pull}
474 (@pxref{Invoking guix pull}).
476 If you prefer to perform the installation steps manually or want to tweak
477 them, you may find the following subsections useful. They describe the
478 software requirements of Guix, as well as how to install it manually and get
482 * Binary Installation:: Getting Guix running in no time!
483 * Requirements:: Software needed to build and run Guix.
484 * Running the Test Suite:: Testing Guix.
485 * Setting Up the Daemon:: Preparing the build daemon's environment.
486 * Invoking guix-daemon:: Running the build daemon.
487 * Application Setup:: Application-specific setup.
490 @node Binary Installation
491 @section Binary Installation
493 @cindex installing Guix from binaries
494 @cindex installer script
495 This section describes how to install Guix on an arbitrary system from a
496 self-contained tarball providing binaries for Guix and for all its
497 dependencies. This is often quicker than installing from source, which
498 is described in the next sections. The only requirement is to have
501 Installing goes along these lines:
505 @cindex downloading Guix binary
506 Download the binary tarball from
507 @indicateurl{https://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz},
508 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
509 already running the kernel Linux, and so on.
511 @c The following is somewhat duplicated in ``System Installation''.
512 Make sure to download the associated @file{.sig} file and to verify the
513 authenticity of the tarball against it, along these lines:
516 $ wget https://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
517 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
520 If that command fails because you do not have the required public key,
521 then run this command to import it:
524 $ gpg --keyserver @value{KEY-SERVER} \
525 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
529 and rerun the @code{gpg --verify} command.
530 @c end authentication part
533 Now, you need to become the @code{root} user. Depending on your distribution,
534 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
538 # tar --warning=no-timestamp -xf \
539 guix-binary-@value{VERSION}.@var{system}.tar.xz
540 # mv var/guix /var/ && mv gnu /
543 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
544 The latter contains a ready-to-use profile for @code{root} (see next
547 Do @emph{not} unpack the tarball on a working Guix system since that
548 would overwrite its own essential files.
550 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
551 not emit warnings about ``implausibly old time stamps'' (such
552 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
554 They stem from the fact that all the
555 files in the archive have their modification time set to zero (which
556 means January 1st, 1970.) This is done on purpose to make sure the
557 archive content is independent of its creation time, thus making it
561 Make the profile available under @file{~root/.config/guix/current}, which is
562 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
565 # mkdir -p ~root/.config/guix
566 # ln -sf /var/guix/profiles/per-user/root/current-guix \
567 ~root/.config/guix/current
570 Source @file{etc/profile} to augment @code{PATH} and other relevant
571 environment variables:
574 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
575 source $GUIX_PROFILE/etc/profile
579 Create the group and user accounts for build users as explained below
580 (@pxref{Build Environment Setup}).
583 Run the daemon, and set it to automatically start on boot.
585 If your host distro uses the systemd init system, this can be achieved
588 @c Versions of systemd that supported symlinked service files are not
589 @c yet widely deployed, so we should suggest that users copy the service
592 @c See this thread for more information:
593 @c http://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
596 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
598 # systemctl start guix-daemon && systemctl enable guix-daemon
601 If your host distro uses the Upstart init system:
604 # initctl reload-configuration
605 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
610 Otherwise, you can still start the daemon manually with:
613 # ~root/.config/guix/current/bin/guix-daemon \
614 --build-users-group=guixbuild
618 Make the @command{guix} command available to other users on the machine,
622 # mkdir -p /usr/local/bin
624 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
627 It is also a good idea to make the Info version of this manual available
631 # mkdir -p /usr/local/share/info
632 # cd /usr/local/share/info
633 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
637 That way, assuming @file{/usr/local/share/info} is in the search path,
638 running @command{info guix} will open this manual (@pxref{Other Info
639 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
643 @cindex substitutes, authorization thereof
644 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
645 (@pxref{Substitutes}), authorize them:
648 # guix archive --authorize < \
649 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
653 Each user may need to perform a few additional steps to make their Guix
654 environment ready for use, @pxref{Application Setup}.
657 Voilà, the installation is complete!
659 You can confirm that Guix is working by installing a sample package into
663 # guix package -i hello
666 The @code{guix} package must remain available in @code{root}'s profile,
667 or it would become subject to garbage collection---in which case you
668 would find yourself badly handicapped by the lack of the @command{guix}
669 command. In other words, do not remove @code{guix} by running
670 @code{guix package -r guix}.
672 The binary installation tarball can be (re)produced and verified simply
673 by running the following command in the Guix source tree:
676 make guix-binary.@var{system}.tar.xz
680 ...@: which, in turn, runs:
683 guix pack -s @var{system} --localstatedir \
684 --profile-name=current-guix guix
687 @xref{Invoking guix pack}, for more info on this handy tool.
690 @section Requirements
692 This section lists requirements when building Guix from source. The
693 build procedure for Guix is the same as for other GNU software, and is
694 not covered here. Please see the files @file{README} and @file{INSTALL}
695 in the Guix source tree for additional details.
697 @cindex official website
698 GNU Guix is available for download from its website at
699 @url{https://www.gnu.org/software/guix/}.
701 GNU Guix depends on the following packages:
704 @item @url{http://gnu.org/software/guile/, GNU Guile}, version 2.2.x;
705 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
708 @uref{http://gnutls.org/, GnuTLS}, specifically its Guile bindings
709 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
710 Guile,, gnutls-guile, GnuTLS-Guile});
712 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
715 @c FIXME: Specify a version number once a release has been made.
716 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
718 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON};
719 @item @url{http://zlib.net, zlib};
720 @item @url{http://www.gnu.org/software/make/, GNU Make}.
723 The following dependencies are optional:
727 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
728 Support for build offloading (@pxref{Daemon Offload Setup}) and
729 @command{guix copy} (@pxref{Invoking guix copy}) depends on
730 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
731 version 0.10.2 or later.
734 When @url{http://www.bzip.org, libbz2} is available,
735 @command{guix-daemon} can use it to compress build logs.
738 Unless @code{--disable-daemon} was passed to @command{configure}, the
739 following packages are also needed:
742 @item @url{http://gnupg.org/, GNU libgcrypt};
743 @item @url{http://sqlite.org, SQLite 3};
744 @item @url{http://gcc.gnu.org, GCC's g++}, with support for the
748 @cindex state directory
749 When configuring Guix on a system that already has a Guix installation,
750 be sure to specify the same state directory as the existing installation
751 using the @code{--localstatedir} option of the @command{configure}
752 script (@pxref{Directory Variables, @code{localstatedir},, standards,
753 GNU Coding Standards}). The @command{configure} script protects against
754 unintended misconfiguration of @var{localstatedir} so you do not
755 inadvertently corrupt your store (@pxref{The Store}).
757 @cindex Nix, compatibility
758 When a working installation of @url{http://nixos.org/nix/, the Nix package
759 manager} is available, you
760 can instead configure Guix with @code{--disable-daemon}. In that case,
761 Nix replaces the three dependencies above.
763 Guix is compatible with Nix, so it is possible to share the same store
764 between both. To do so, you must pass @command{configure} not only the
765 same @code{--with-store-dir} value, but also the same
766 @code{--localstatedir} value. The latter is essential because it
767 specifies where the database that stores metadata about the store is
768 located, among other things. The default values for Nix are
769 @code{--with-store-dir=/nix/store} and @code{--localstatedir=/nix/var}.
770 Note that @code{--disable-daemon} is not required if
771 your goal is to share the store with Nix.
773 @node Running the Test Suite
774 @section Running the Test Suite
777 After a successful @command{configure} and @code{make} run, it is a good
778 idea to run the test suite. It can help catch issues with the setup or
779 environment, or bugs in Guix itself---and really, reporting test
780 failures is a good way to help improve the software. To run the test
787 Test cases can run in parallel: you can use the @code{-j} option of
788 GNU@tie{}make to speed things up. The first run may take a few minutes
789 on a recent machine; subsequent runs will be faster because the store
790 that is created for test purposes will already have various things in
793 It is also possible to run a subset of the tests by defining the
794 @code{TESTS} makefile variable as in this example:
797 make check TESTS="tests/store.scm tests/cpio.scm"
800 By default, tests results are displayed at a file level. In order to
801 see the details of every individual test cases, it is possible to define
802 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
805 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
808 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
809 @file{test-suite.log} file. Please specify the Guix version being used
810 as well as version numbers of the dependencies (@pxref{Requirements}) in
813 Guix also comes with a whole-system test suite that tests complete
814 GuixSD operating system instances. It can only run on systems where
815 Guix is already installed, using:
822 or, again, by defining @code{TESTS} to select a subset of tests to run:
825 make check-system TESTS="basic mcron"
828 These system tests are defined in the @code{(gnu tests @dots{})}
829 modules. They work by running the operating systems under test with
830 lightweight instrumentation in a virtual machine (VM). They can be
831 computationally intensive or rather cheap, depending on whether
832 substitutes are available for their dependencies (@pxref{Substitutes}).
833 Some of them require a lot of storage space to hold VM images.
835 Again in case of test failures, please send @email{bug-guix@@gnu.org}
838 @node Setting Up the Daemon
839 @section Setting Up the Daemon
842 Operations such as building a package or running the garbage collector
843 are all performed by a specialized process, the @dfn{build daemon}, on
844 behalf of clients. Only the daemon may access the store and its
845 associated database. Thus, any operation that manipulates the store
846 goes through the daemon. For instance, command-line tools such as
847 @command{guix package} and @command{guix build} communicate with the
848 daemon (@i{via} remote procedure calls) to instruct it what to do.
850 The following sections explain how to prepare the build daemon's
851 environment. See also @ref{Substitutes}, for information on how to allow
852 the daemon to download pre-built binaries.
855 * Build Environment Setup:: Preparing the isolated build environment.
856 * Daemon Offload Setup:: Offloading builds to remote machines.
857 * SELinux Support:: Using an SELinux policy for the daemon.
860 @node Build Environment Setup
861 @subsection Build Environment Setup
863 @cindex build environment
864 In a standard multi-user setup, Guix and its daemon---the
865 @command{guix-daemon} program---are installed by the system
866 administrator; @file{/gnu/store} is owned by @code{root} and
867 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
868 Guix tools to build packages or otherwise access the store, and the
869 daemon will do it on their behalf, ensuring that the store is kept in a
870 consistent state, and allowing built packages to be shared among users.
873 When @command{guix-daemon} runs as @code{root}, you may not want package
874 build processes themselves to run as @code{root} too, for obvious
875 security reasons. To avoid that, a special pool of @dfn{build users}
876 should be created for use by build processes started by the daemon.
877 These build users need not have a shell and a home directory: they will
878 just be used when the daemon drops @code{root} privileges in build
879 processes. Having several such users allows the daemon to launch
880 distinct build processes under separate UIDs, which guarantees that they
881 do not interfere with each other---an essential feature since builds are
882 regarded as pure functions (@pxref{Introduction}).
884 On a GNU/Linux system, a build user pool may be created like this (using
885 Bash syntax and the @code{shadow} commands):
887 @c See http://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
888 @c for why `-G' is needed.
890 # groupadd --system guixbuild
891 # for i in `seq -w 1 10`;
893 useradd -g guixbuild -G guixbuild \
894 -d /var/empty -s `which nologin` \
895 -c "Guix build user $i" --system \
901 The number of build users determines how many build jobs may run in
902 parallel, as specified by the @option{--max-jobs} option
903 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
904 @command{guix system vm} and related commands, you may need to add the
905 build users to the @code{kvm} group so they can access @file{/dev/kvm},
906 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
907 (@pxref{Invoking guix system}).
909 The @code{guix-daemon} program may then be run as @code{root} with the
910 following command@footnote{If your machine uses the systemd init system,
911 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
912 file in @file{/etc/systemd/system} will ensure that
913 @command{guix-daemon} is automatically started. Similarly, if your
914 machine uses the Upstart init system, drop the
915 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
916 file in @file{/etc/init}.}:
919 # guix-daemon --build-users-group=guixbuild
924 This way, the daemon starts build processes in a chroot, under one of
925 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
926 environment contains nothing but:
928 @c Keep this list in sync with libstore/build.cc! -----------------------
931 a minimal @code{/dev} directory, created mostly independently from the
932 host @code{/dev}@footnote{``Mostly'', because while the set of files
933 that appear in the chroot's @code{/dev} is fixed, most of these files
934 can only be created if the host has them.};
937 the @code{/proc} directory; it only shows the processes of the container
938 since a separate PID name space is used;
941 @file{/etc/passwd} with an entry for the current user and an entry for
945 @file{/etc/group} with an entry for the user's group;
948 @file{/etc/hosts} with an entry that maps @code{localhost} to
952 a writable @file{/tmp} directory.
955 You can influence the directory where the daemon stores build trees
956 @i{via} the @code{TMPDIR} environment variable. However, the build tree
957 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
958 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
959 This way, the value of @code{TMPDIR} does not leak inside build
960 environments, which avoids discrepancies in cases where build processes
961 capture the name of their build tree.
964 The daemon also honors the @code{http_proxy} environment variable for
965 HTTP downloads it performs, be it for fixed-output derivations
966 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
968 If you are installing Guix as an unprivileged user, it is still possible
969 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
970 However, build processes will not be isolated from one another, and not
971 from the rest of the system. Thus, build processes may interfere with
972 each other, and may access programs, libraries, and other files
973 available on the system---making it much harder to view them as
974 @emph{pure} functions.
977 @node Daemon Offload Setup
978 @subsection Using the Offload Facility
982 When desired, the build daemon can @dfn{offload} derivation builds to
983 other machines running Guix, using the @code{offload} @dfn{build
984 hook}@footnote{This feature is available only when
985 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
987 feature is enabled, a list of user-specified build machines is read from
988 @file{/etc/guix/machines.scm}; every time a build is requested, for
989 instance via @code{guix build}, the daemon attempts to offload it to one
990 of the machines that satisfy the constraints of the derivation, in
991 particular its system type---e.g., @file{x86_64-linux}. Missing
992 prerequisites for the build are copied over SSH to the target machine,
993 which then proceeds with the build; upon success the output(s) of the
994 build are copied back to the initial machine.
996 The @file{/etc/guix/machines.scm} file typically looks like this:
1000 (name "eightysix.example.org")
1001 (system "x86_64-linux")
1002 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1004 (speed 2.)) ;incredibly fast!
1007 (name "meeps.example.org")
1008 (system "mips64el-linux")
1009 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1012 (string-append (getenv "HOME")
1013 "/.ssh/identity-for-guix"))))
1017 In the example above we specify a list of two build machines, one for
1018 the @code{x86_64} architecture and one for the @code{mips64el}
1021 In fact, this file is---not surprisingly!---a Scheme file that is
1022 evaluated when the @code{offload} hook is started. Its return value
1023 must be a list of @code{build-machine} objects. While this example
1024 shows a fixed list of build machines, one could imagine, say, using
1025 DNS-SD to return a list of potential build machines discovered in the
1026 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1027 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1030 @deftp {Data Type} build-machine
1031 This data type represents build machines to which the daemon may offload
1032 builds. The important fields are:
1037 The host name of the remote machine.
1040 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1043 The user account to use when connecting to the remote machine over SSH.
1044 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1045 allow non-interactive logins.
1048 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1049 This is used to authenticate the machine when we connect to it. It is a
1050 long string that looks like this:
1053 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1056 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1057 key can be found in a file such as
1058 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1060 If the machine is running the SSH daemon of GNU@tie{}lsh,
1061 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1062 similar file. It can be converted to the OpenSSH format using
1063 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1066 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1067 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1072 A number of optional fields may be specified:
1076 @item @code{port} (default: @code{22})
1077 Port number of SSH server on the machine.
1079 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1080 The SSH private key file to use when connecting to the machine, in
1081 OpenSSH format. This key must not be protected with a passphrase.
1083 Note that the default value is the private key @emph{of the root
1084 account}. Make sure it exists if you use the default.
1086 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1087 @itemx @code{compression-level} (default: @code{3})
1088 The SSH-level compression methods and compression level requested.
1090 Note that offloading relies on SSH compression to reduce bandwidth usage
1091 when transferring files to and from build machines.
1093 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1094 File name of the Unix-domain socket @command{guix-daemon} is listening
1097 @item @code{parallel-builds} (default: @code{1})
1098 The number of builds that may run in parallel on the machine.
1100 @item @code{speed} (default: @code{1.0})
1101 A ``relative speed factor''. The offload scheduler will tend to prefer
1102 machines with a higher speed factor.
1104 @item @code{features} (default: @code{'()})
1105 A list of strings denoting specific features supported by the machine.
1106 An example is @code{"kvm"} for machines that have the KVM Linux modules
1107 and corresponding hardware support. Derivations can request features by
1108 name, and they will be scheduled on matching build machines.
1113 The @command{guix} command must be in the search path on the build
1114 machines. You can check whether this is the case by running:
1117 ssh build-machine guix repl --version
1120 There is one last thing to do once @file{machines.scm} is in place. As
1121 explained above, when offloading, files are transferred back and forth
1122 between the machine stores. For this to work, you first need to
1123 generate a key pair on each machine to allow the daemon to export signed
1124 archives of files from the store (@pxref{Invoking guix archive}):
1127 # guix archive --generate-key
1131 Each build machine must authorize the key of the master machine so that
1132 it accepts store items it receives from the master:
1135 # guix archive --authorize < master-public-key.txt
1139 Likewise, the master machine must authorize the key of each build machine.
1141 All the fuss with keys is here to express pairwise mutual trust
1142 relations between the master and the build machines. Concretely, when
1143 the master receives files from a build machine (and @i{vice versa}), its
1144 build daemon can make sure they are genuine, have not been tampered
1145 with, and that they are signed by an authorized key.
1147 @cindex offload test
1148 To test whether your setup is operational, run this command on the
1155 This will attempt to connect to each of the build machines specified in
1156 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1157 available on each machine, attempt to export to the machine and import
1158 from it, and report any error in the process.
1160 If you want to test a different machine file, just specify it on the
1164 # guix offload test machines-qualif.scm
1167 Last, you can test the subset of the machines whose name matches a
1168 regular expression like this:
1171 # guix offload test machines.scm '\.gnu\.org$'
1174 @cindex offload status
1175 To display the current load of all build hosts, run this command on the
1179 # guix offload status
1183 @node SELinux Support
1184 @subsection SELinux Support
1186 @cindex SELinux, daemon policy
1187 @cindex mandatory access control, SELinux
1188 @cindex security, guix-daemon
1189 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1190 can be installed on a system where SELinux is enabled, in order to label
1191 Guix files and to specify the expected behavior of the daemon. Since
1192 GuixSD does not provide an SELinux base policy, the daemon policy cannot
1195 @subsubsection Installing the SELinux policy
1196 @cindex SELinux, policy installation
1197 To install the policy run this command as root:
1200 semodule -i etc/guix-daemon.cil
1203 Then relabel the file system with @code{restorecon} or by a different
1204 mechanism provided by your system.
1206 Once the policy is installed, the file system has been relabeled, and
1207 the daemon has been restarted, it should be running in the
1208 @code{guix_daemon_t} context. You can confirm this with the following
1212 ps -Zax | grep guix-daemon
1215 Monitor the SELinux log files as you run a command like @code{guix build
1216 hello} to convince yourself that SELinux permits all necessary
1219 @subsubsection Limitations
1220 @cindex SELinux, limitations
1222 This policy is not perfect. Here is a list of limitations or quirks
1223 that should be considered when deploying the provided SELinux policy for
1228 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1229 operations involve contexts that have anything to do with
1230 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1231 but it would be preferrable to define socket rules for only this label.
1234 @code{guix gc} cannot access arbitrary links to profiles. By design,
1235 the file label of the destination of a symlink is independent of the
1236 file label of the link itself. Although all profiles under
1237 $localstatedir are labelled, the links to these profiles inherit the
1238 label of the directory they are in. For links in the user’s home
1239 directory this will be @code{user_home_t}. But for links from the root
1240 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1241 directory, etc, this won’t work. @code{guix gc} would be prevented from
1242 reading and following these links.
1245 The daemon’s feature to listen for TCP connections might no longer work.
1246 This might require extra rules, because SELinux treats network sockets
1247 differently from files.
1250 Currently all files with a name matching the regular expression
1251 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1252 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1253 that name in any profile would be permitted to run in the
1254 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1255 build a package that provides this executable and convince a user to
1256 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1257 At that point SELinux could not prevent it from accessing files that are
1258 allowed for processes in that domain.
1260 We could generate a much more restrictive policy at installation time,
1261 so that only the @emph{exact} file name of the currently installed
1262 @code{guix-daemon} executable would be labelled with
1263 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1264 The downside is that root would have to install or upgrade the policy at
1265 installation time whenever the Guix package that provides the
1266 effectively running @code{guix-daemon} executable is upgraded.
1269 @node Invoking guix-daemon
1270 @section Invoking @command{guix-daemon}
1272 The @command{guix-daemon} program implements all the functionality to
1273 access the store. This includes launching build processes, running the
1274 garbage collector, querying the availability of a build result, etc. It
1275 is normally run as @code{root} like this:
1278 # guix-daemon --build-users-group=guixbuild
1282 For details on how to set it up, @pxref{Setting Up the Daemon}.
1285 @cindex container, build environment
1286 @cindex build environment
1287 @cindex reproducible builds
1288 By default, @command{guix-daemon} launches build processes under
1289 different UIDs, taken from the build group specified with
1290 @code{--build-users-group}. In addition, each build process is run in a
1291 chroot environment that only contains the subset of the store that the
1292 build process depends on, as specified by its derivation
1293 (@pxref{Programming Interface, derivation}), plus a set of specific
1294 system directories. By default, the latter contains @file{/dev} and
1295 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1296 @dfn{container}: in addition to having its own file system tree, it has
1297 a separate mount name space, its own PID name space, network name space,
1298 etc. This helps achieve reproducible builds (@pxref{Features}).
1300 When the daemon performs a build on behalf of the user, it creates a
1301 build directory under @file{/tmp} or under the directory specified by
1302 its @code{TMPDIR} environment variable. This directory is shared with
1303 the container for the duration of the build, though within the container,
1304 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1306 The build directory is automatically deleted upon completion, unless the
1307 build failed and the client specified @option{--keep-failed}
1308 (@pxref{Invoking guix build, @option{--keep-failed}}).
1310 The daemon listens for connections and spawns one sub-process for each session
1311 started by a client (one of the @command{guix} sub-commands.) The
1312 @command{guix processes} command allows you to get an overview of the activity
1313 on your system by viewing each of the active sessions and clients.
1314 @xref{Invoking guix processes}, for more information.
1316 The following command-line options are supported:
1319 @item --build-users-group=@var{group}
1320 Take users from @var{group} to run build processes (@pxref{Setting Up
1321 the Daemon, build users}).
1323 @item --no-substitutes
1325 Do not use substitutes for build products. That is, always build things
1326 locally instead of allowing downloads of pre-built binaries
1327 (@pxref{Substitutes}).
1329 When the daemon runs with @code{--no-substitutes}, clients can still
1330 explicitly enable substitution @i{via} the @code{set-build-options}
1331 remote procedure call (@pxref{The Store}).
1333 @item --substitute-urls=@var{urls}
1334 @anchor{daemon-substitute-urls}
1335 Consider @var{urls} the default whitespace-separated list of substitute
1336 source URLs. When this option is omitted,
1337 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1339 This means that substitutes may be downloaded from @var{urls}, as long
1340 as they are signed by a trusted signature (@pxref{Substitutes}).
1343 @item --no-build-hook
1344 Do not use the @dfn{build hook}.
1346 The build hook is a helper program that the daemon can start and to
1347 which it submits build requests. This mechanism is used to offload
1348 builds to other machines (@pxref{Daemon Offload Setup}).
1350 @item --cache-failures
1351 Cache build failures. By default, only successful builds are cached.
1353 When this option is used, @command{guix gc --list-failures} can be used
1354 to query the set of store items marked as failed; @command{guix gc
1355 --clear-failures} removes store items from the set of cached failures.
1356 @xref{Invoking guix gc}.
1358 @item --cores=@var{n}
1360 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1363 The default value is @code{0}, but it may be overridden by clients, such
1364 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1367 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1368 in the build process, which can then use it to exploit internal
1369 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1371 @item --max-jobs=@var{n}
1373 Allow at most @var{n} build jobs in parallel. The default value is
1374 @code{1}. Setting it to @code{0} means that no builds will be performed
1375 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1376 Setup}), or simply fail.
1378 @item --max-silent-time=@var{seconds}
1379 When the build or substitution process remains silent for more than
1380 @var{seconds}, terminate it and report a build failure.
1382 The default value is @code{0}, which disables the timeout.
1384 The value specified here can be overridden by clients (@pxref{Common
1385 Build Options, @code{--max-silent-time}}).
1387 @item --timeout=@var{seconds}
1388 Likewise, when the build or substitution process lasts for more than
1389 @var{seconds}, terminate it and report a build failure.
1391 The default value is @code{0}, which disables the timeout.
1393 The value specified here can be overridden by clients (@pxref{Common
1394 Build Options, @code{--timeout}}).
1396 @item --rounds=@var{N}
1397 Build each derivation @var{n} times in a row, and raise an error if
1398 consecutive build results are not bit-for-bit identical. Note that this
1399 setting can be overridden by clients such as @command{guix build}
1400 (@pxref{Invoking guix build}).
1402 When used in conjunction with @option{--keep-failed}, the differing
1403 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1404 This makes it easy to look for differences between the two results.
1407 Produce debugging output.
1409 This is useful to debug daemon start-up issues, but then it may be
1410 overridden by clients, for example the @code{--verbosity} option of
1411 @command{guix build} (@pxref{Invoking guix build}).
1413 @item --chroot-directory=@var{dir}
1414 Add @var{dir} to the build chroot.
1416 Doing this may change the result of build processes---for instance if
1417 they use optional dependencies found in @var{dir} when it is available,
1418 and not otherwise. For that reason, it is not recommended to do so.
1419 Instead, make sure that each derivation declares all the inputs that it
1422 @item --disable-chroot
1423 Disable chroot builds.
1425 Using this option is not recommended since, again, it would allow build
1426 processes to gain access to undeclared dependencies. It is necessary,
1427 though, when @command{guix-daemon} is running under an unprivileged user
1430 @item --log-compression=@var{type}
1431 Compress build logs according to @var{type}, one of @code{gzip},
1432 @code{bzip2}, or @code{none}.
1434 Unless @code{--lose-logs} is used, all the build logs are kept in the
1435 @var{localstatedir}. To save space, the daemon automatically compresses
1436 them with bzip2 by default.
1438 @item --disable-deduplication
1439 @cindex deduplication
1440 Disable automatic file ``deduplication'' in the store.
1442 By default, files added to the store are automatically ``deduplicated'':
1443 if a newly added file is identical to another one found in the store,
1444 the daemon makes the new file a hard link to the other file. This can
1445 noticeably reduce disk usage, at the expense of slightly increased
1446 input/output load at the end of a build process. This option disables
1449 @item --gc-keep-outputs[=yes|no]
1450 Tell whether the garbage collector (GC) must keep outputs of live
1454 @cindex garbage collector roots
1455 When set to ``yes'', the GC will keep the outputs of any live derivation
1456 available in the store---the @code{.drv} files. The default is ``no'',
1457 meaning that derivation outputs are kept only if they are reachable from a GC
1458 root. @xref{Invoking guix gc}, for more on GC roots.
1460 @item --gc-keep-derivations[=yes|no]
1461 Tell whether the garbage collector (GC) must keep derivations
1462 corresponding to live outputs.
1464 When set to ``yes'', as is the case by default, the GC keeps
1465 derivations---i.e., @code{.drv} files---as long as at least one of their
1466 outputs is live. This allows users to keep track of the origins of
1467 items in their store. Setting it to ``no'' saves a bit of disk space.
1469 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1470 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1471 ``yes'' causes liveness to flow from derivations to outputs. When both are
1472 set to ``yes'', the effect is to keep all the build prerequisites (the
1473 sources, compiler, libraries, and other build-time tools) of live objects in
1474 the store, regardless of whether these prerequisites are reachable from a GC
1475 root. This is convenient for developers since it saves rebuilds or downloads.
1477 @item --impersonate-linux-2.6
1478 On Linux-based systems, impersonate Linux 2.6. This means that the
1479 kernel's @code{uname} system call will report 2.6 as the release number.
1481 This might be helpful to build programs that (usually wrongfully) depend
1482 on the kernel version number.
1485 Do not keep build logs. By default they are kept under
1486 @code{@var{localstatedir}/guix/log}.
1488 @item --system=@var{system}
1489 Assume @var{system} as the current system type. By default it is the
1490 architecture/kernel pair found at configure time, such as
1491 @code{x86_64-linux}.
1493 @item --listen=@var{endpoint}
1494 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1495 as the file name of a Unix-domain socket if it starts with
1496 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1497 host name or host name and port to listen to. Here are a few examples:
1500 @item --listen=/gnu/var/daemon
1501 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1502 creating it if needed.
1504 @item --listen=localhost
1505 @cindex daemon, remote access
1506 @cindex remote access to the daemon
1507 @cindex daemon, cluster setup
1508 @cindex clusters, daemon setup
1509 Listen for TCP connections on the network interface corresponding to
1510 @code{localhost}, on port 44146.
1512 @item --listen=128.0.0.42:1234
1513 Listen for TCP connections on the network interface corresponding to
1514 @code{128.0.0.42}, on port 1234.
1517 This option can be repeated multiple times, in which case
1518 @command{guix-daemon} accepts connections on all the specified
1519 endpoints. Users can tell client commands what endpoint to connect to
1520 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1521 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1524 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1525 @code{--listen=@var{host}} is suitable on local networks, such as
1526 clusters, where only trusted nodes may connect to the build daemon. In
1527 other cases where remote access to the daemon is needed, we recommend
1528 using Unix-domain sockets along with SSH.
1531 When @code{--listen} is omitted, @command{guix-daemon} listens for
1532 connections on the Unix-domain socket located at
1533 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1537 @node Application Setup
1538 @section Application Setup
1540 @cindex foreign distro
1541 When using Guix on top of GNU/Linux distribution other than GuixSD---a
1542 so-called @dfn{foreign distro}---a few additional steps are needed to
1543 get everything in place. Here are some of them.
1547 @anchor{locales-and-locpath}
1548 @cindex locales, when not on GuixSD
1550 @vindex GUIX_LOCPATH
1551 Packages installed @i{via} Guix will not use the locale data of the
1552 host system. Instead, you must first install one of the locale packages
1553 available with Guix and then define the @code{GUIX_LOCPATH} environment
1557 $ guix package -i glibc-locales
1558 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1561 Note that the @code{glibc-locales} package contains data for all the
1562 locales supported by the GNU@tie{}libc and weighs in at around
1563 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1564 limited to a few UTF-8 locales.
1566 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1567 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1568 Manual}). There are two important differences though:
1572 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1573 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1574 to make sure the programs of the foreign distro will not end up loading
1575 incompatible locale data.
1578 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1579 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1580 should your Guix profile contain a mixture of programs linked against
1581 different libc version, each libc version will only try to load locale
1582 data in the right format.
1585 This is important because the locale data format used by different libc
1586 versions may be incompatible.
1588 @subsection Name Service Switch
1590 @cindex name service switch, glibc
1591 @cindex NSS (name service switch), glibc
1592 @cindex nscd (name service caching daemon)
1593 @cindex name service caching daemon (nscd)
1594 When using Guix on a foreign distro, we @emph{strongly recommend} that
1595 the system run the GNU C library's @dfn{name service cache daemon},
1596 @command{nscd}, which should be listening on the
1597 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1598 installed with Guix may fail to look up host names or user accounts, or
1599 may even crash. The next paragraphs explain why.
1601 @cindex @file{nsswitch.conf}
1602 The GNU C library implements a @dfn{name service switch} (NSS), which is
1603 an extensible mechanism for ``name lookups'' in general: host name
1604 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1605 The GNU C Library Reference Manual}).
1607 @cindex Network information service (NIS)
1608 @cindex NIS (Network information service)
1609 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1610 lookup implementations: for example, the @code{nss-mdns} plugin allow
1611 resolution of @code{.local} host names, the @code{nis} plugin allows
1612 user account lookup using the Network information service (NIS), and so
1613 on. These extra ``lookup services'' are configured system-wide in
1614 @file{/etc/nsswitch.conf}, and all the programs running on the system
1615 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1618 When they perform a name lookup---for instance by calling the
1619 @code{getaddrinfo} function in C---applications first try to connect to
1620 the nscd; on success, nscd performs name lookups on their behalf. If
1621 the nscd is not running, then they perform the name lookup by
1622 themselves, by loading the name lookup services into their own address
1623 space and running it. These name lookup services---the
1624 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1625 the host system's C library, rather than from the C library the
1626 application is linked against (the C library coming from Guix).
1628 And this is where the problem is: if your application is linked against
1629 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1630 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1631 likely crash or have its name lookups fail unexpectedly.
1633 Running @command{nscd} on the system, among other advantages, eliminates
1634 this binary incompatibility problem because those @code{libnss_*.so}
1635 files are loaded in the @command{nscd} process, not in applications
1638 @subsection X11 Fonts
1641 The majority of graphical applications use Fontconfig to locate and
1642 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1643 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1644 by default. Thus, to allow graphical applications installed with Guix
1645 to display fonts, you have to install fonts with Guix as well.
1646 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1647 @code{font-gnu-freefont-ttf}.
1649 To display text written in Chinese languages, Japanese, or Korean in
1650 graphical applications, consider installing
1651 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1652 has multiple outputs, one per language family (@pxref{Packages with
1653 Multiple Outputs}). For instance, the following command installs fonts
1654 for Chinese languages:
1657 guix package -i font-adobe-source-han-sans:cn
1660 @cindex @code{xterm}
1661 Older programs such as @command{xterm} do not use Fontconfig and instead
1662 rely on server-side font rendering. Such programs require to specify a
1663 full name of a font using XLFD (X Logical Font Description), like this:
1666 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1669 To be able to use such full names for the TrueType fonts installed in
1670 your Guix profile, you need to extend the font path of the X server:
1672 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1673 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1675 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1678 @cindex @code{xlsfonts}
1679 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1680 to make sure your TrueType fonts are listed there.
1682 @cindex @code{fc-cache}
1684 After installing fonts you may have to refresh the font cache to use
1685 them in applications. The same applies when applications installed via
1686 Guix do not seem to find fonts. To force rebuilding of the font cache
1687 run @code{fc-cache -f}. The @code{fc-cache} command is provided by the
1688 @code{fontconfig} package.
1690 @subsection X.509 Certificates
1692 @cindex @code{nss-certs}
1693 The @code{nss-certs} package provides X.509 certificates, which allow
1694 programs to authenticate Web servers accessed over HTTPS.
1696 When using Guix on a foreign distro, you can install this package and
1697 define the relevant environment variables so that packages know where to
1698 look for certificates. @xref{X.509 Certificates}, for detailed
1701 @subsection Emacs Packages
1703 @cindex @code{emacs}
1704 When you install Emacs packages with Guix, the elisp files may be placed
1705 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1707 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1708 directory exists because potentially there may exist thousands of Emacs
1709 packages and storing all their files in a single directory may not be
1710 reliable (because of name conflicts). So we think using a separate
1711 directory for each package is a good idea. It is very similar to how
1712 the Emacs package system organizes the file structure (@pxref{Package
1713 Files,,, emacs, The GNU Emacs Manual}).
1715 By default, Emacs (installed with Guix) ``knows'' where these packages
1716 are placed, so you do not need to perform any configuration. If, for
1717 some reason, you want to avoid auto-loading Emacs packages installed
1718 with Guix, you can do so by running Emacs with @code{--no-site-file}
1719 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1721 @subsection The GCC toolchain
1726 Guix offers individual compiler packages such as @code{gcc} but if you
1727 are in need of a complete toolchain for compiling and linking source
1728 code what you really want is the @code{gcc-toolchain} package. This
1729 package provides a complete GCC toolchain for C/C++ development,
1730 including GCC itself, the GNU C Library (headers and binaries, plus
1731 debugging symbols in the @code{debug} output), Binutils, and a linker
1734 @cindex attempt to use impure library, error message
1736 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1737 passed to the linker, add corresponding @code{-rpath} arguments, and
1738 invoke the actual linker with this new set of arguments. By default,
1739 the linker wrapper refuses to link to libraries outside the store to
1740 ensure ``purity''. This can be annoying when using the toolchain to
1741 link with local libraries. To allow references to libraries outside the
1742 store you need to define the environment variable
1743 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES}.
1747 @c *********************************************************************
1748 @node Package Management
1749 @chapter Package Management
1752 The purpose of GNU Guix is to allow users to easily install, upgrade, and
1753 remove software packages, without having to know about their build
1754 procedures or dependencies. Guix also goes beyond this obvious set of
1757 This chapter describes the main features of Guix, as well as the
1758 package management tools it provides. Along with the command-line
1759 interface described below (@pxref{Invoking guix package, @code{guix
1760 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
1761 emacs-guix, The Emacs-Guix Reference Manual}), after installing
1762 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
1766 guix package -i emacs-guix
1770 * Features:: How Guix will make your life brighter.
1771 * Invoking guix package:: Package installation, removal, etc.
1772 * Substitutes:: Downloading pre-built binaries.
1773 * Packages with Multiple Outputs:: Single source package, multiple outputs.
1774 * Invoking guix gc:: Running the garbage collector.
1775 * Invoking guix pull:: Fetching the latest Guix and distribution.
1776 * Channels:: Customizing the package collection.
1777 * Inferiors:: Interacting with another revision of Guix.
1778 * Invoking guix describe:: Display information about your Guix revision.
1779 * Invoking guix pack:: Creating software bundles.
1780 * Invoking guix archive:: Exporting and importing store files.
1786 When using Guix, each package ends up in the @dfn{package store}, in its
1787 own directory---something that resembles
1788 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
1790 Instead of referring to these directories, users have their own
1791 @dfn{profile}, which points to the packages that they actually want to
1792 use. These profiles are stored within each user's home directory, at
1793 @code{$HOME/.guix-profile}.
1795 For example, @code{alice} installs GCC 4.7.2. As a result,
1796 @file{/home/alice/.guix-profile/bin/gcc} points to
1797 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
1798 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
1799 simply continues to point to
1800 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
1801 coexist on the same system without any interference.
1803 The @command{guix package} command is the central tool to manage
1804 packages (@pxref{Invoking guix package}). It operates on the per-user
1805 profiles, and can be used @emph{with normal user privileges}.
1807 @cindex transactions
1808 The command provides the obvious install, remove, and upgrade
1809 operations. Each invocation is actually a @emph{transaction}: either
1810 the specified operation succeeds, or nothing happens. Thus, if the
1811 @command{guix package} process is terminated during the transaction,
1812 or if a power outage occurs during the transaction, then the user's
1813 profile remains in its previous state, and remains usable.
1815 In addition, any package transaction may be @emph{rolled back}. So, if,
1816 for example, an upgrade installs a new version of a package that turns
1817 out to have a serious bug, users may roll back to the previous instance
1818 of their profile, which was known to work well. Similarly, the global
1819 system configuration on GuixSD is subject to
1820 transactional upgrades and roll-back
1821 (@pxref{Using the Configuration System}).
1823 All packages in the package store may be @emph{garbage-collected}.
1824 Guix can determine which packages are still referenced by user
1825 profiles, and remove those that are provably no longer referenced
1826 (@pxref{Invoking guix gc}). Users may also explicitly remove old
1827 generations of their profile so that the packages they refer to can be
1830 @cindex reproducibility
1831 @cindex reproducible builds
1832 Guix takes a @dfn{purely functional} approach to package
1833 management, as described in the introduction (@pxref{Introduction}).
1834 Each @file{/gnu/store} package directory name contains a hash of all the
1835 inputs that were used to build that package---compiler, libraries, build
1836 scripts, etc. This direct correspondence allows users to make sure a
1837 given package installation matches the current state of their
1838 distribution. It also helps maximize @dfn{build reproducibility}:
1839 thanks to the isolated build environments that are used, a given build
1840 is likely to yield bit-identical files when performed on different
1841 machines (@pxref{Invoking guix-daemon, container}).
1844 This foundation allows Guix to support @dfn{transparent binary/source
1845 deployment}. When a pre-built binary for a @file{/gnu/store} item is
1846 available from an external source---a @dfn{substitute}, Guix just
1847 downloads it and unpacks it;
1848 otherwise, it builds the package from source, locally
1849 (@pxref{Substitutes}). Because build results are usually bit-for-bit
1850 reproducible, users do not have to trust servers that provide
1851 substitutes: they can force a local build and @emph{challenge} providers
1852 (@pxref{Invoking guix challenge}).
1854 Control over the build environment is a feature that is also useful for
1855 developers. The @command{guix environment} command allows developers of
1856 a package to quickly set up the right development environment for their
1857 package, without having to manually install the dependencies of the
1858 package into their profile (@pxref{Invoking guix environment}).
1860 @cindex replication, of software environments
1861 @cindex provenance tracking, of software artifacts
1862 All of Guix and its package definitions is version-controlled, and
1863 @command{guix pull} allows you to ``travel in time'' on the history of Guix
1864 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
1865 Guix instance on a different machine or at a later point in time, which in
1866 turn allows you to @emph{replicate complete software environments}, while
1867 retaining precise @dfn{provenance tracking} of the software.
1869 @node Invoking guix package
1870 @section Invoking @command{guix package}
1872 @cindex installing packages
1873 @cindex removing packages
1874 @cindex package installation
1875 @cindex package removal
1876 The @command{guix package} command is the tool that allows users to
1877 install, upgrade, and remove packages, as well as rolling back to
1878 previous configurations. It operates only on the user's own profile,
1879 and works with normal user privileges (@pxref{Features}). Its syntax
1883 guix package @var{options}
1885 @cindex transactions
1886 Primarily, @var{options} specifies the operations to be performed during
1887 the transaction. Upon completion, a new profile is created, but
1888 previous @dfn{generations} of the profile remain available, should the user
1891 For example, to remove @code{lua} and install @code{guile} and
1892 @code{guile-cairo} in a single transaction:
1895 guix package -r lua -i guile guile-cairo
1898 @command{guix package} also supports a @dfn{declarative approach}
1899 whereby the user specifies the exact set of packages to be available and
1900 passes it @i{via} the @option{--manifest} option
1901 (@pxref{profile-manifest, @option{--manifest}}).
1904 For each user, a symlink to the user's default profile is automatically
1905 created in @file{$HOME/.guix-profile}. This symlink always points to the
1906 current generation of the user's default profile. Thus, users can add
1907 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
1908 variable, and so on.
1909 @cindex search paths
1910 If you are not using the Guix System Distribution, consider adding the
1911 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
1912 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
1913 shells get all the right environment variable definitions:
1916 GUIX_PROFILE="$HOME/.guix-profile" ; \
1917 source "$HOME/.guix-profile/etc/profile"
1920 In a multi-user setup, user profiles are stored in a place registered as
1921 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
1922 to (@pxref{Invoking guix gc}). That directory is normally
1923 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
1924 @var{localstatedir} is the value passed to @code{configure} as
1925 @code{--localstatedir}, and @var{user} is the user name. The
1926 @file{per-user} directory is created when @command{guix-daemon} is
1927 started, and the @var{user} sub-directory is created by @command{guix
1930 The @var{options} can be among the following:
1934 @item --install=@var{package} @dots{}
1935 @itemx -i @var{package} @dots{}
1936 Install the specified @var{package}s.
1938 Each @var{package} may specify either a simple package name, such as
1939 @code{guile}, or a package name followed by an at-sign and version number,
1940 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
1941 case, the newest version prefixed by @code{1.8} is selected.)
1943 If no version number is specified, the
1944 newest available version will be selected. In addition, @var{package}
1945 may contain a colon, followed by the name of one of the outputs of the
1946 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
1947 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
1948 name (and optionally version) are searched for among the GNU
1949 distribution modules (@pxref{Package Modules}).
1951 @cindex propagated inputs
1952 Sometimes packages have @dfn{propagated inputs}: these are dependencies
1953 that automatically get installed along with the required package
1954 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
1955 @code{package} objects}, for information about propagated inputs in
1956 package definitions).
1958 @anchor{package-cmd-propagated-inputs}
1959 An example is the GNU MPC library: its C header files refer to those of
1960 the GNU MPFR library, which in turn refer to those of the GMP library.
1961 Thus, when installing MPC, the MPFR and GMP libraries also get installed
1962 in the profile; removing MPC also removes MPFR and GMP---unless they had
1963 also been explicitly installed by the user.
1965 Besides, packages sometimes rely on the definition of environment
1966 variables for their search paths (see explanation of
1967 @code{--search-paths} below). Any missing or possibly incorrect
1968 environment variable definitions are reported here.
1970 @item --install-from-expression=@var{exp}
1972 Install the package @var{exp} evaluates to.
1974 @var{exp} must be a Scheme expression that evaluates to a
1975 @code{<package>} object. This option is notably useful to disambiguate
1976 between same-named variants of a package, with expressions such as
1977 @code{(@@ (gnu packages base) guile-final)}.
1979 Note that this option installs the first output of the specified
1980 package, which may be insufficient when needing a specific output of a
1981 multiple-output package.
1983 @item --install-from-file=@var{file}
1984 @itemx -f @var{file}
1985 Install the package that the code within @var{file} evaluates to.
1987 As an example, @var{file} might contain a definition like this
1988 (@pxref{Defining Packages}):
1991 @verbatiminclude package-hello.scm
1994 Developers may find it useful to include such a @file{guix.scm} file
1995 in the root of their project source tree that can be used to test
1996 development snapshots and create reproducible development environments
1997 (@pxref{Invoking guix environment}).
1999 @item --remove=@var{package} @dots{}
2000 @itemx -r @var{package} @dots{}
2001 Remove the specified @var{package}s.
2003 As for @code{--install}, each @var{package} may specify a version number
2004 and/or output name in addition to the package name. For instance,
2005 @code{-r glibc:debug} would remove the @code{debug} output of
2008 @item --upgrade[=@var{regexp} @dots{}]
2009 @itemx -u [@var{regexp} @dots{}]
2010 @cindex upgrading packages
2011 Upgrade all the installed packages. If one or more @var{regexp}s are
2012 specified, upgrade only installed packages whose name matches a
2013 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2015 Note that this upgrades package to the latest version of packages found
2016 in the distribution currently installed. To update your distribution,
2017 you should regularly run @command{guix pull} (@pxref{Invoking guix
2020 @item --do-not-upgrade[=@var{regexp} @dots{}]
2021 When used together with the @code{--upgrade} option, do @emph{not}
2022 upgrade any packages whose name matches a @var{regexp}. For example, to
2023 upgrade all packages in the current profile except those containing the
2024 substring ``emacs'':
2027 $ guix package --upgrade . --do-not-upgrade emacs
2030 @item @anchor{profile-manifest}--manifest=@var{file}
2031 @itemx -m @var{file}
2032 @cindex profile declaration
2033 @cindex profile manifest
2034 Create a new generation of the profile from the manifest object
2035 returned by the Scheme code in @var{file}.
2037 This allows you to @emph{declare} the profile's contents rather than
2038 constructing it through a sequence of @code{--install} and similar
2039 commands. The advantage is that @var{file} can be put under version
2040 control, copied to different machines to reproduce the same profile, and
2043 @c FIXME: Add reference to (guix profile) documentation when available.
2044 @var{file} must return a @dfn{manifest} object, which is roughly a list
2047 @findex packages->manifest
2049 (use-package-modules guile emacs)
2054 ;; Use a specific package output.
2055 (list guile-2.0 "debug")))
2058 @findex specifications->manifest
2059 In this example we have to know which modules define the @code{emacs}
2060 and @code{guile-2.0} variables to provide the right
2061 @code{use-package-modules} line, which can be cumbersome. We can
2062 instead provide regular package specifications and let
2063 @code{specifications->manifest} look up the corresponding package
2067 (specifications->manifest
2068 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2072 @cindex rolling back
2073 @cindex undoing transactions
2074 @cindex transactions, undoing
2075 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2076 the last transaction.
2078 When combined with options such as @code{--install}, roll back occurs
2079 before any other actions.
2081 When rolling back from the first generation that actually contains
2082 installed packages, the profile is made to point to the @dfn{zeroth
2083 generation}, which contains no files apart from its own metadata.
2085 After having rolled back, installing, removing, or upgrading packages
2086 overwrites previous future generations. Thus, the history of the
2087 generations in a profile is always linear.
2089 @item --switch-generation=@var{pattern}
2090 @itemx -S @var{pattern}
2092 Switch to a particular generation defined by @var{pattern}.
2094 @var{pattern} may be either a generation number or a number prefixed
2095 with ``+'' or ``-''. The latter means: move forward/backward by a
2096 specified number of generations. For example, if you want to return to
2097 the latest generation after @code{--roll-back}, use
2098 @code{--switch-generation=+1}.
2100 The difference between @code{--roll-back} and
2101 @code{--switch-generation=-1} is that @code{--switch-generation} will
2102 not make a zeroth generation, so if a specified generation does not
2103 exist, the current generation will not be changed.
2105 @item --search-paths[=@var{kind}]
2106 @cindex search paths
2107 Report environment variable definitions, in Bash syntax, that may be
2108 needed in order to use the set of installed packages. These environment
2109 variables are used to specify @dfn{search paths} for files used by some
2110 of the installed packages.
2112 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2113 environment variables to be defined so it can look for headers and
2114 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2115 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2116 library are installed in the profile, then @code{--search-paths} will
2117 suggest setting these variables to @code{@var{profile}/include} and
2118 @code{@var{profile}/lib}, respectively.
2120 The typical use case is to define these environment variables in the
2124 $ eval `guix package --search-paths`
2127 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2128 meaning that the returned environment variable definitions will either
2129 be exact settings, or prefixes or suffixes of the current value of these
2130 variables. When omitted, @var{kind} defaults to @code{exact}.
2132 This option can also be used to compute the @emph{combined} search paths
2133 of several profiles. Consider this example:
2136 $ guix package -p foo -i guile
2137 $ guix package -p bar -i guile-json
2138 $ guix package -p foo -p bar --search-paths
2141 The last command above reports about the @code{GUILE_LOAD_PATH}
2142 variable, even though, taken individually, neither @file{foo} nor
2143 @file{bar} would lead to that recommendation.
2146 @item --profile=@var{profile}
2147 @itemx -p @var{profile}
2148 Use @var{profile} instead of the user's default profile.
2150 @cindex collisions, in a profile
2151 @cindex colliding packages in profiles
2152 @cindex profile collisions
2153 @item --allow-collisions
2154 Allow colliding packages in the new profile. Use at your own risk!
2156 By default, @command{guix package} reports as an error @dfn{collisions}
2157 in the profile. Collisions happen when two or more different versions
2158 or variants of a given package end up in the profile.
2161 Use the bootstrap Guile to build the profile. This option is only
2162 useful to distribution developers.
2166 In addition to these actions, @command{guix package} supports the
2167 following options to query the current state of a profile, or the
2168 availability of packages:
2172 @item --search=@var{regexp}
2173 @itemx -s @var{regexp}
2174 @cindex searching for packages
2175 List the available packages whose name, synopsis, or description matches
2176 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
2177 Print all the metadata of matching packages in
2178 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
2179 GNU recutils manual}).
2181 This allows specific fields to be extracted using the @command{recsel}
2182 command, for instance:
2185 $ guix package -s malloc | recsel -p name,version,relevance
2199 Similarly, to show the name of all the packages available under the
2200 terms of the GNU@tie{}LGPL version 3:
2203 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
2210 It is also possible to refine search results using several @code{-s}
2211 flags. For example, the following command returns a list of board
2215 $ guix package -s '\<board\>' -s game | recsel -p name
2220 If we were to omit @code{-s game}, we would also get software packages
2221 that deal with printed circuit boards; removing the angle brackets
2222 around @code{board} would further add packages that have to do with
2225 And now for a more elaborate example. The following command searches
2226 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
2227 libraries, and prints the name and synopsis of the matching packages:
2230 $ guix package -s crypto -s library | \
2231 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
2235 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
2236 information on @dfn{selection expressions} for @code{recsel -e}.
2238 @item --show=@var{package}
2239 Show details about @var{package}, taken from the list of available packages, in
2240 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
2244 $ guix package --show=python | recsel -p name,version
2252 You may also specify the full name of a package to only get details about a
2253 specific version of it:
2255 $ guix package --show=python@@3.4 | recsel -p name,version
2262 @item --list-installed[=@var{regexp}]
2263 @itemx -I [@var{regexp}]
2264 List the currently installed packages in the specified profile, with the
2265 most recently installed packages shown last. When @var{regexp} is
2266 specified, list only installed packages whose name matches @var{regexp}.
2268 For each installed package, print the following items, separated by
2269 tabs: the package name, its version string, the part of the package that
2270 is installed (for instance, @code{out} for the default output,
2271 @code{include} for its headers, etc.), and the path of this package in
2274 @item --list-available[=@var{regexp}]
2275 @itemx -A [@var{regexp}]
2276 List packages currently available in the distribution for this system
2277 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
2278 installed packages whose name matches @var{regexp}.
2280 For each package, print the following items separated by tabs: its name,
2281 its version string, the parts of the package (@pxref{Packages with
2282 Multiple Outputs}), and the source location of its definition.
2284 @item --list-generations[=@var{pattern}]
2285 @itemx -l [@var{pattern}]
2287 Return a list of generations along with their creation dates; for each
2288 generation, show the installed packages, with the most recently
2289 installed packages shown last. Note that the zeroth generation is never
2292 For each installed package, print the following items, separated by
2293 tabs: the name of a package, its version string, the part of the package
2294 that is installed (@pxref{Packages with Multiple Outputs}), and the
2295 location of this package in the store.
2297 When @var{pattern} is used, the command returns only matching
2298 generations. Valid patterns include:
2301 @item @emph{Integers and comma-separated integers}. Both patterns denote
2302 generation numbers. For instance, @code{--list-generations=1} returns
2305 And @code{--list-generations=1,8,2} outputs three generations in the
2306 specified order. Neither spaces nor trailing commas are allowed.
2308 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
2309 specified generations and everything in between. Note that the start of
2310 a range must be smaller than its end.
2312 It is also possible to omit the endpoint. For example,
2313 @code{--list-generations=2..}, returns all generations starting from the
2316 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
2317 or months by passing an integer along with the first letter of the
2318 duration. For example, @code{--list-generations=20d} lists generations
2319 that are up to 20 days old.
2322 @item --delete-generations[=@var{pattern}]
2323 @itemx -d [@var{pattern}]
2324 When @var{pattern} is omitted, delete all generations except the current
2327 This command accepts the same patterns as @option{--list-generations}.
2328 When @var{pattern} is specified, delete the matching generations. When
2329 @var{pattern} specifies a duration, generations @emph{older} than the
2330 specified duration match. For instance, @code{--delete-generations=1m}
2331 deletes generations that are more than one month old.
2333 If the current generation matches, it is @emph{not} deleted. Also, the
2334 zeroth generation is never deleted.
2336 Note that deleting generations prevents rolling back to them.
2337 Consequently, this command must be used with care.
2341 Finally, since @command{guix package} may actually start build
2342 processes, it supports all the common build options (@pxref{Common Build
2343 Options}). It also supports package transformation options, such as
2344 @option{--with-source} (@pxref{Package Transformation Options}).
2345 However, note that package transformations are lost when upgrading; to
2346 preserve transformations across upgrades, you should define your own
2347 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
2348 (@pxref{Defining Packages}).
2351 @section Substitutes
2354 @cindex pre-built binaries
2355 Guix supports transparent source/binary deployment, which means that it
2356 can either build things locally, or download pre-built items from a
2357 server, or both. We call these pre-built items @dfn{substitutes}---they
2358 are substitutes for local build results. In many cases, downloading a
2359 substitute is much faster than building things locally.
2361 Substitutes can be anything resulting from a derivation build
2362 (@pxref{Derivations}). Of course, in the common case, they are
2363 pre-built package binaries, but source tarballs, for instance, which
2364 also result from derivation builds, can be available as substitutes.
2367 * Official Substitute Server:: One particular source of substitutes.
2368 * Substitute Server Authorization:: How to enable or disable substitutes.
2369 * Substitute Authentication:: How Guix verifies substitutes.
2370 * Proxy Settings:: How to get substitutes via proxy.
2371 * Substitution Failure:: What happens when substitution fails.
2372 * On Trusting Binaries:: How can you trust that binary blob?
2375 @node Official Substitute Server
2376 @subsection Official Substitute Server
2380 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
2381 that builds packages from Guix continuously for some
2382 architectures, and makes them available as substitutes. This is the
2383 default source of substitutes; it can be overridden by passing the
2384 @option{--substitute-urls} option either to @command{guix-daemon}
2385 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
2386 or to client tools such as @command{guix package}
2387 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
2390 Substitute URLs can be either HTTP or HTTPS.
2391 HTTPS is recommended because communications are encrypted; conversely,
2392 using HTTP makes all communications visible to an eavesdropper, who
2393 could use the information gathered to determine, for instance, whether
2394 your system has unpatched security vulnerabilities.
2396 Substitutes from the official build farm are enabled by default when
2397 using the Guix System Distribution (@pxref{GNU Distribution}). However,
2398 they are disabled by default when using Guix on a foreign distribution,
2399 unless you have explicitly enabled them via one of the recommended
2400 installation steps (@pxref{Installation}). The following paragraphs
2401 describe how to enable or disable substitutes for the official build
2402 farm; the same procedure can also be used to enable substitutes for any
2403 other substitute server.
2405 @node Substitute Server Authorization
2406 @subsection Substitute Server Authorization
2409 @cindex substitutes, authorization thereof
2410 @cindex access control list (ACL), for substitutes
2411 @cindex ACL (access control list), for substitutes
2412 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
2414 must add its public key to the access control list (ACL) of archive
2415 imports, using the @command{guix archive} command (@pxref{Invoking guix
2416 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
2417 be compromised and to serve genuine substitutes.
2419 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
2420 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
2421 the installation prefix of Guix. If you installed Guix from source,
2422 make sure you checked the GPG signature of
2423 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
2424 Then, you can run something like this:
2427 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
2431 Similarly, the @file{hydra.gnu.org.pub} file contains the public key
2432 of an independent build farm also run by the project, reachable at
2433 @indicateurl{https://mirror.hydra.gnu.org}.
2436 Once this is in place, the output of a command like @code{guix build}
2437 should change from something like:
2440 $ guix build emacs --dry-run
2441 The following derivations would be built:
2442 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
2443 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
2444 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
2445 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
2453 $ guix build emacs --dry-run
2454 112.3 MB would be downloaded:
2455 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
2456 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
2457 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
2458 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
2463 This indicates that substitutes from @code{@value{SUBSTITUTE-SERVER}} are usable and
2464 will be downloaded, when possible, for future builds.
2466 @cindex substitutes, how to disable
2467 The substitute mechanism can be disabled globally by running
2468 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
2469 guix-daemon}). It can also be disabled temporarily by passing the
2470 @code{--no-substitutes} option to @command{guix package}, @command{guix
2471 build}, and other command-line tools.
2473 @node Substitute Authentication
2474 @subsection Substitute Authentication
2476 @cindex digital signatures
2477 Guix detects and raises an error when attempting to use a substitute
2478 that has been tampered with. Likewise, it ignores substitutes that are
2479 not signed, or that are not signed by one of the keys listed in the ACL.
2481 There is one exception though: if an unauthorized server provides
2482 substitutes that are @emph{bit-for-bit identical} to those provided by
2483 an authorized server, then the unauthorized server becomes eligible for
2484 downloads. For example, assume we have chosen two substitute servers
2488 --substitute-urls="https://a.example.org https://b.example.org"
2492 @cindex reproducible builds
2493 If the ACL contains only the key for @code{b.example.org}, and if
2494 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
2495 then Guix will download substitutes from @code{a.example.org} because it
2496 comes first in the list and can be considered a mirror of
2497 @code{b.example.org}. In practice, independent build machines usually
2498 produce the same binaries, thanks to bit-reproducible builds (see
2501 When using HTTPS, the server's X.509 certificate is @emph{not} validated
2502 (in other words, the server is not authenticated), contrary to what
2503 HTTPS clients such as Web browsers usually do. This is because Guix
2504 authenticates substitute information itself, as explained above, which
2505 is what we care about (whereas X.509 certificates are about
2506 authenticating bindings between domain names and public keys.)
2508 @node Proxy Settings
2509 @subsection Proxy Settings
2512 Substitutes are downloaded over HTTP or HTTPS.
2513 The @code{http_proxy} environment
2514 variable can be set in the environment of @command{guix-daemon} and is
2515 honored for downloads of substitutes. Note that the value of
2516 @code{http_proxy} in the environment where @command{guix build},
2517 @command{guix package}, and other client commands are run has
2518 @emph{absolutely no effect}.
2520 @node Substitution Failure
2521 @subsection Substitution Failure
2523 Even when a substitute for a derivation is available, sometimes the
2524 substitution attempt will fail. This can happen for a variety of
2525 reasons: the substitute server might be offline, the substitute may
2526 recently have been deleted, the connection might have been interrupted,
2529 When substitutes are enabled and a substitute for a derivation is
2530 available, but the substitution attempt fails, Guix will attempt to
2531 build the derivation locally depending on whether or not
2532 @code{--fallback} was given (@pxref{fallback-option,, common build
2533 option @code{--fallback}}). Specifically, if @code{--fallback} was
2534 omitted, then no local build will be performed, and the derivation is
2535 considered to have failed. However, if @code{--fallback} was given,
2536 then Guix will attempt to build the derivation locally, and the success
2537 or failure of the derivation depends on the success or failure of the
2538 local build. Note that when substitutes are disabled or no substitute
2539 is available for the derivation in question, a local build will
2540 @emph{always} be performed, regardless of whether or not
2541 @code{--fallback} was given.
2543 To get an idea of how many substitutes are available right now, you can
2544 try running the @command{guix weather} command (@pxref{Invoking guix
2545 weather}). This command provides statistics on the substitutes provided
2548 @node On Trusting Binaries
2549 @subsection On Trusting Binaries
2551 @cindex trust, of pre-built binaries
2552 Today, each individual's control over their own computing is at the
2553 mercy of institutions, corporations, and groups with enough power and
2554 determination to subvert the computing infrastructure and exploit its
2555 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
2556 convenient, we encourage users to also build on their own, or even run
2557 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
2558 interesting target. One way to help is by publishing the software you
2559 build using @command{guix publish} so that others have one more choice
2560 of server to download substitutes from (@pxref{Invoking guix publish}).
2562 Guix has the foundations to maximize build reproducibility
2563 (@pxref{Features}). In most cases, independent builds of a given
2564 package or derivation should yield bit-identical results. Thus, through
2565 a diverse set of independent package builds, we can strengthen the
2566 integrity of our systems. The @command{guix challenge} command aims to
2567 help users assess substitute servers, and to assist developers in
2568 finding out about non-deterministic package builds (@pxref{Invoking guix
2569 challenge}). Similarly, the @option{--check} option of @command{guix
2570 build} allows users to check whether previously-installed substitutes
2571 are genuine by rebuilding them locally (@pxref{build-check,
2572 @command{guix build --check}}).
2574 In the future, we want Guix to have support to publish and retrieve
2575 binaries to/from other users, in a peer-to-peer fashion. If you would
2576 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
2578 @node Packages with Multiple Outputs
2579 @section Packages with Multiple Outputs
2581 @cindex multiple-output packages
2582 @cindex package outputs
2585 Often, packages defined in Guix have a single @dfn{output}---i.e., the
2586 source package leads to exactly one directory in the store. When running
2587 @command{guix package -i glibc}, one installs the default output of the
2588 GNU libc package; the default output is called @code{out}, but its name
2589 can be omitted as shown in this command. In this particular case, the
2590 default output of @code{glibc} contains all the C header files, shared
2591 libraries, static libraries, Info documentation, and other supporting
2594 Sometimes it is more appropriate to separate the various types of files
2595 produced from a single source package into separate outputs. For
2596 instance, the GLib C library (used by GTK+ and related packages)
2597 installs more than 20 MiB of reference documentation as HTML pages.
2598 To save space for users who do not need it, the documentation goes to a
2599 separate output, called @code{doc}. To install the main GLib output,
2600 which contains everything but the documentation, one would run:
2603 guix package -i glib
2606 @cindex documentation
2607 The command to install its documentation is:
2610 guix package -i glib:doc
2613 Some packages install programs with different ``dependency footprints''.
2614 For instance, the WordNet package installs both command-line tools and
2615 graphical user interfaces (GUIs). The former depend solely on the C
2616 library, whereas the latter depend on Tcl/Tk and the underlying X
2617 libraries. In this case, we leave the command-line tools in the default
2618 output, whereas the GUIs are in a separate output. This allows users
2619 who do not need the GUIs to save space. The @command{guix size} command
2620 can help find out about such situations (@pxref{Invoking guix size}).
2621 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
2623 There are several such multiple-output packages in the GNU distribution.
2624 Other conventional output names include @code{lib} for libraries and
2625 possibly header files, @code{bin} for stand-alone programs, and
2626 @code{debug} for debugging information (@pxref{Installing Debugging
2627 Files}). The outputs of a packages are listed in the third column of
2628 the output of @command{guix package --list-available} (@pxref{Invoking
2632 @node Invoking guix gc
2633 @section Invoking @command{guix gc}
2635 @cindex garbage collector
2637 Packages that are installed, but not used, may be @dfn{garbage-collected}.
2638 The @command{guix gc} command allows users to explicitly run the garbage
2639 collector to reclaim space from the @file{/gnu/store} directory. It is
2640 the @emph{only} way to remove files from @file{/gnu/store}---removing
2641 files or directories manually may break it beyond repair!
2644 @cindex garbage collector roots
2645 The garbage collector has a set of known @dfn{roots}: any file under
2646 @file{/gnu/store} reachable from a root is considered @dfn{live} and
2647 cannot be deleted; any other file is considered @dfn{dead} and may be
2648 deleted. The set of garbage collector roots (``GC roots'' for short)
2649 includes default user profiles; by default, the symlinks under
2650 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
2651 added with @command{guix build --root}, for example (@pxref{Invoking
2654 Prior to running @code{guix gc --collect-garbage} to make space, it is
2655 often useful to remove old generations from user profiles; that way, old
2656 package builds referenced by those generations can be reclaimed. This
2657 is achieved by running @code{guix package --delete-generations}
2658 (@pxref{Invoking guix package}).
2660 Our recommendation is to run a garbage collection periodically, or when
2661 you are short on disk space. For instance, to guarantee that at least
2662 5@tie{}GB are available on your disk, simply run:
2668 It is perfectly safe to run as a non-interactive periodic job
2669 (@pxref{Scheduled Job Execution}, for how to set up such a job on
2670 GuixSD). Running @command{guix gc} with no arguments will collect as
2671 much garbage as it can, but that is often inconvenient: you may find
2672 yourself having to rebuild or re-download software that is ``dead'' from
2673 the GC viewpoint but that is necessary to build other pieces of
2674 software---e.g., the compiler tool chain.
2676 The @command{guix gc} command has three modes of operation: it can be
2677 used to garbage-collect any dead files (the default), to delete specific
2678 files (the @code{--delete} option), to print garbage-collector
2679 information, or for more advanced queries. The garbage collection
2680 options are as follows:
2683 @item --collect-garbage[=@var{min}]
2684 @itemx -C [@var{min}]
2685 Collect garbage---i.e., unreachable @file{/gnu/store} files and
2686 sub-directories. This is the default operation when no option is
2689 When @var{min} is given, stop once @var{min} bytes have been collected.
2690 @var{min} may be a number of bytes, or it may include a unit as a
2691 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
2692 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
2694 When @var{min} is omitted, collect all the garbage.
2696 @item --free-space=@var{free}
2697 @itemx -F @var{free}
2698 Collect garbage until @var{free} space is available under
2699 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
2700 as @code{500MiB}, as described above.
2702 When @var{free} or more is already available in @file{/gnu/store}, do
2703 nothing and exit immediately.
2707 Attempt to delete all the store files and directories specified as
2708 arguments. This fails if some of the files are not in the store, or if
2709 they are still live.
2711 @item --list-failures
2712 List store items corresponding to cached build failures.
2714 This prints nothing unless the daemon was started with
2715 @option{--cache-failures} (@pxref{Invoking guix-daemon,
2716 @option{--cache-failures}}).
2718 @item --clear-failures
2719 Remove the specified store items from the failed-build cache.
2721 Again, this option only makes sense when the daemon is started with
2722 @option{--cache-failures}. Otherwise, it does nothing.
2725 Show the list of dead files and directories still present in the
2726 store---i.e., files and directories no longer reachable from any root.
2729 Show the list of live store files and directories.
2733 In addition, the references among existing store files can be queried:
2739 @cindex package dependencies
2740 List the references (respectively, the referrers) of store files given
2746 List the requisites of the store files passed as arguments. Requisites
2747 include the store files themselves, their references, and the references
2748 of these, recursively. In other words, the returned list is the
2749 @dfn{transitive closure} of the store files.
2751 @xref{Invoking guix size}, for a tool to profile the size of the closure
2752 of an element. @xref{Invoking guix graph}, for a tool to visualize
2753 the graph of references.
2757 Return the derivation(s) leading to the given store items
2758 (@pxref{Derivations}).
2760 For example, this command:
2763 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
2767 returns the @file{.drv} file(s) leading to the @code{emacs} package
2768 installed in your profile.
2770 Note that there may be zero matching @file{.drv} files, for instance
2771 because these files have been garbage-collected. There can also be more
2772 than one matching @file{.drv} due to fixed-output derivations.
2775 Lastly, the following options allow you to check the integrity of the
2776 store and to control disk usage.
2780 @item --verify[=@var{options}]
2781 @cindex integrity, of the store
2782 @cindex integrity checking
2783 Verify the integrity of the store.
2785 By default, make sure that all the store items marked as valid in the
2786 database of the daemon actually exist in @file{/gnu/store}.
2788 When provided, @var{options} must be a comma-separated list containing one
2789 or more of @code{contents} and @code{repair}.
2791 When passing @option{--verify=contents}, the daemon computes the
2792 content hash of each store item and compares it against its hash in the
2793 database. Hash mismatches are reported as data corruptions. Because it
2794 traverses @emph{all the files in the store}, this command can take a
2795 long time, especially on systems with a slow disk drive.
2797 @cindex repairing the store
2798 @cindex corruption, recovering from
2799 Using @option{--verify=repair} or @option{--verify=contents,repair}
2800 causes the daemon to try to repair corrupt store items by fetching
2801 substitutes for them (@pxref{Substitutes}). Because repairing is not
2802 atomic, and thus potentially dangerous, it is available only to the
2803 system administrator. A lightweight alternative, when you know exactly
2804 which items in the store are corrupt, is @command{guix build --repair}
2805 (@pxref{Invoking guix build}).
2808 @cindex deduplication
2809 Optimize the store by hard-linking identical files---this is
2810 @dfn{deduplication}.
2812 The daemon performs deduplication after each successful build or archive
2813 import, unless it was started with @code{--disable-deduplication}
2814 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
2815 this option is primarily useful when the daemon was running with
2816 @code{--disable-deduplication}.
2820 @node Invoking guix pull
2821 @section Invoking @command{guix pull}
2823 @cindex upgrading Guix
2824 @cindex updating Guix
2825 @cindex @command{guix pull}
2827 Packages are installed or upgraded to the latest version available in
2828 the distribution currently available on your local machine. To update
2829 that distribution, along with the Guix tools, you must run @command{guix
2830 pull}: the command downloads the latest Guix source code and package
2831 descriptions, and deploys it. Source code is downloaded from a
2832 @uref{https://git-scm.com, Git} repository, by default the official
2833 GNU@tie{}Guix repository, though this can be customized.
2835 On completion, @command{guix package} will use packages and package
2836 versions from this just-retrieved copy of Guix. Not only that, but all
2837 the Guix commands and Scheme modules will also be taken from that latest
2838 version. New @command{guix} sub-commands added by the update also
2841 Any user can update their Guix copy using @command{guix pull}, and the
2842 effect is limited to the user who run @command{guix pull}. For
2843 instance, when user @code{root} runs @command{guix pull}, this has no
2844 effect on the version of Guix that user @code{alice} sees, and vice
2847 The result of running @command{guix pull} is a @dfn{profile} available
2848 under @file{~/.config/guix/current} containing the latest Guix. Thus,
2849 make sure to add it to the beginning of your search path so that you use
2850 the latest version, and similarly for the Info manual
2851 (@pxref{Documentation}):
2854 export PATH="$HOME/.config/guix/current/bin:$PATH"
2855 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
2858 The @code{--list-generations} or @code{-l} option lists past generations
2859 produced by @command{guix pull}, along with details about their provenance:
2863 Generation 1 Jun 10 2018 00:18:18
2865 repository URL: https://git.savannah.gnu.org/git/guix.git
2866 branch: origin/master
2867 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
2869 Generation 2 Jun 11 2018 11:02:49
2871 repository URL: https://git.savannah.gnu.org/git/guix.git
2872 branch: origin/master
2873 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
2874 2 new packages: keepalived, libnfnetlink
2875 6 packages upgraded: emacs-nix-mode@@2.0.4,
2876 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
2877 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
2879 Generation 3 Jun 13 2018 23:31:07 (current)
2881 repository URL: https://git.savannah.gnu.org/git/guix.git
2882 branch: origin/master
2883 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
2884 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
2885 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
2888 @ref{Invoking guix describe, @command{guix describe}}, for other ways to
2889 describe the current status of Guix.
2891 This @code{~/.config/guix/current} profile works like any other profile
2892 created by @command{guix package} (@pxref{Invoking guix package}). That
2893 is, you can list generations, roll back to the previous
2894 generation---i.e., the previous Guix---and so on:
2897 $ guix package -p ~/.config/guix/current --roll-back
2898 switched from generation 3 to 2
2899 $ guix package -p ~/.config/guix/current --delete-generations=1
2900 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
2903 The @command{guix pull} command is usually invoked with no arguments,
2904 but it supports the following options:
2907 @item --url=@var{url}
2908 @itemx --commit=@var{commit}
2909 @itemx --branch=@var{branch}
2910 Download code from the specified @var{url}, at the given @var{commit} (a valid
2911 Git commit ID represented as a hexadecimal string), or @var{branch}.
2913 @cindex @file{channels.scm}, configuration file
2914 @cindex configuration file for channels
2915 These options are provided for convenience, but you can also specify your
2916 configuration in the @file{~/.config/guix/channels.scm} file or using the
2917 @option{--channels} option (see below).
2919 @item --channels=@var{file}
2920 @itemx -C @var{file}
2921 Read the list of channels from @var{file} instead of
2922 @file{~/.config/guix/channels.scm}. @var{file} must contain Scheme code that
2923 evaluates to a list of channel objects. @xref{Channels}, for more
2926 @item --list-generations[=@var{pattern}]
2927 @itemx -l [@var{pattern}]
2928 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
2929 is provided, the subset of generations that match @var{pattern}.
2930 The syntax of @var{pattern} is the same as with @code{guix package
2931 --list-generations} (@pxref{Invoking guix package}).
2933 @ref{Invoking guix describe}, for a way to display information about the
2934 current generation only.
2936 @item --profile=@var{profile}
2937 @itemx -p @var{profile}
2938 Use @var{profile} instead of @file{~/.config/guix/current}.
2942 Show which channel commit(s) would be used and what would be built or
2943 substituted but do not actually do it.
2945 @item --system=@var{system}
2946 @itemx -s @var{system}
2947 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
2948 the system type of the build host.
2951 Produce verbose output, writing build logs to the standard error output.
2954 Use the bootstrap Guile to build the latest Guix. This option is only
2955 useful to Guix developers.
2958 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
2959 repository and branch to pull from, as well as @emph{additional} repositories
2960 containing package modules that should be deployed. @xref{Channels}, for more
2963 In addition, @command{guix pull} supports all the common build options
2964 (@pxref{Common Build Options}).
2970 @cindex @file{channels.scm}, configuration file
2971 @cindex configuration file for channels
2972 @cindex @command{guix pull}, configuration file
2973 @cindex configuration of @command{guix pull}
2974 Guix and its package collection are updated by running @command{guix pull}
2975 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
2976 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
2977 customized by defining @dfn{channels} in the
2978 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
2979 of a Git repository to be deployed, and @command{guix pull} can be instructed
2980 to pull from one or more channels. In other words, channels can be used to
2981 @emph{customize} and to @emph{extend} Guix, as we will see below.
2983 @subsection Using a Custom Guix Channel
2985 The channel called @code{guix} specifies where Guix itself---its command-line
2986 tools as well as its package collection---should be downloaded. For instance,
2987 suppose you want to update from your own copy of the Guix repository at
2988 @code{example.org}, and specifically the @code{super-hacks} branch, you can
2989 write in @code{~/.config/guix/channels.scm} this specification:
2992 ;; Tell 'guix pull' to use my own repo.
2995 (url "https://example.org/my-guix.git")
2996 (branch "super-hacks")))
3000 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3001 branch of the repository at @code{example.org}.
3003 @subsection Specifying Additional Channels
3005 @cindex extending the package collection (channels)
3006 @cindex personal packages (channels)
3007 @cindex channels, for personal packages
3008 You can also specify @emph{additional channels} to pull from. Let's say you
3009 have a bunch of custom package variants or personal packages that you think
3010 would make little sense to contribute to the Guix project, but would like to
3011 have these packages transparently available to you at the command line. You
3012 would first write modules containing those package definitions (@pxref{Package
3013 Modules}), maintain them in a Git repository, and then you and anyone else can
3014 use it as an additional channel to get packages from. Neat, no?
3016 @c What follows stems from discussions at
3017 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3018 @c earlier discussions on guix-devel@gnu.org.
3020 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3021 publish your personal channel to the world, we would like to share a few words
3026 Before publishing a channel, please consider contributing your package
3027 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3028 to free software of all sorts, and packages in Guix proper are readily
3029 available to all Guix users and benefit from the project's quality assurance
3033 When you maintain package definitions outside Guix, we, Guix developers,
3034 consider that @emph{the compatibility burden is on you}. Remember that
3035 package modules and package definitions are just Scheme code that uses various
3036 programming interfaces (APIs). We want to remain free to change these APIs to
3037 keep improving Guix, possibly in ways that break your channel. We never
3038 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3042 Corollary: if you're using an external channel and that channel breaks, please
3043 @emph{report the issue to the channel authors}, not to the Guix project.
3046 You've been warned! Having said this, we believe external channels are a
3047 practical way to exert your freedom to augment Guix' package collection and to
3048 share your improvements, which are basic tenets of
3049 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3050 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3053 Once you have a Git repository containing your own package modules, you can
3054 write @code{~/.config/guix/channels.scm} to instruct @command{guix pull} to
3055 pull from your personal channel @emph{in addition} to the default Guix
3058 @vindex %default-channels
3060 ;; Add my personal packages to those Guix provides.
3062 (name 'my-personal-packages)
3063 (url "https://example.org/personal-packages.git"))
3068 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3069 add a channel the list of channels that the variable @code{%default-channels}
3070 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3071 Manual}). With this file in place, @command{guix pull} builds not only Guix
3072 but also the package modules from your own repository. The result in
3073 @file{~/.config/guix/current} is the union of Guix with your own package
3077 $ guix pull --list-generations
3079 Generation 19 Aug 27 2018 16:20:48
3081 repository URL: https://git.savannah.gnu.org/git/guix.git
3083 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
3084 my-personal-packages dd3df5e
3085 repository URL: https://example.org/personal-packages.git
3087 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
3088 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
3089 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
3093 The output of @command{guix pull} above shows that Generation@tie{}19 includes
3094 both Guix and packages from the @code{my-personal-packages} channel. Among
3095 the new and upgraded packages that are listed, some like @code{my-gimp} and
3096 @code{my-emacs-with-cool-features} might come from
3097 @code{my-personal-packages}, while others come from the Guix default channel.
3099 @cindex dependencies, channels
3100 @cindex meta-data, channels
3101 @subsection Declaring Channel Dependencies
3103 Channel authors may decide to augment a package collection provided by other
3104 channels. They can declare their channel to be dependent on other channels in
3105 a meta-data file @file{.guix-channel}, which is to be placed in the root of
3106 the channel repository.
3108 The meta-data file should contain a simple S-expression like this:
3115 (name some-collection)
3116 (url "https://example.org/first-collection.git"))
3118 (name some-other-collection)
3119 (url "https://example.org/second-collection.git")
3120 (branch "testing"))))
3123 In the above example this channel is declared to depend on two other channels,
3124 which will both be fetched automatically. The modules provided by the channel
3125 will be compiled in an environment where the modules of all these declared
3126 channels are available.
3128 For the sake of reliability and maintainability, you should avoid dependencies
3129 on channels that you don't control, and you should aim to keep the number of
3130 dependencies to a minimum.
3132 @subsection Replicating Guix
3134 @cindex pinning, channels
3135 @cindex replicating Guix
3136 @cindex reproducibility, of Guix
3137 The @command{guix pull --list-generations} output above shows precisely which
3138 commits were used to build this instance of Guix. We can thus replicate it,
3139 say, on another machine, by providing a channel specification in
3140 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
3143 ;; Deploy specific commits of my channels of interest.
3146 (url "https://git.savannah.gnu.org/git/guix.git")
3147 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
3149 (name 'my-personal-packages)
3150 (url "https://example.org/personal-packages.git")
3151 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
3154 The @command{guix describe --format=channels} command can even generate this
3155 list of channels directly (@pxref{Invoking guix describe}).
3157 At this point the two machines run the @emph{exact same Guix}, with access to
3158 the @emph{exact same packages}. The output of @command{guix build gimp} on
3159 one machine will be exactly the same, bit for bit, as the output of the same
3160 command on the other machine. It also means both machines have access to all
3161 the source code of Guix and, transitively, to all the source code of every
3164 This gives you super powers, allowing you to track the provenance of binary
3165 artifacts with very fine grain, and to reproduce software environments at
3166 will---some sort of ``meta reproducibility'' capabilities, if you will.
3167 @xref{Inferiors}, for another way to take advantage of these super powers.
3172 @c TODO: Remove this once we're more confident about API stability.
3174 The functionality described here is a ``technology preview'' as of version
3175 @value{VERSION}. As such, the interface is subject to change.
3179 @cindex composition of Guix revisions
3180 Sometimes you might need to mix packages from the revision of Guix you're
3181 currently running with packages available in a different revision of Guix.
3182 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
3183 revisions in arbitrary ways.
3185 @cindex inferior packages
3186 Technically, an ``inferior'' is essentially a separate Guix process connected
3187 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
3188 @code{(guix inferior)} module allows you to create inferiors and to
3189 communicate with them. It also provides a high-level interface to browse and
3190 manipulate the packages that an inferior provides---@dfn{inferior packages}.
3192 When combined with channels (@pxref{Channels}), inferiors provide a simple way
3193 to interact with a separate revision of Guix. For example, let's assume you
3194 want to install in your profile the current @code{guile} package, along with
3195 the @code{guile-json} as it existed in an older revision of Guix---perhaps
3196 because the newer @code{guile-json} has an incompatible API and you want to
3197 run your code against the old API@. To do that, you could write a manifest for
3198 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
3199 manifest, you would create an inferior for that old Guix revision you care
3200 about, and you would look up the @code{guile-json} package in the inferior:
3203 (use-modules (guix inferior) (guix channels)
3204 (srfi srfi-1)) ;for 'first'
3207 ;; This is the old revision from which we want to
3208 ;; extract guile-json.
3211 (url "https://git.savannah.gnu.org/git/guix.git")
3213 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
3216 ;; An inferior representing the above revision.
3217 (inferior-for-channels channels))
3219 ;; Now create a manifest with the current "guile" package
3220 ;; and the old "guile-json" package.
3222 (list (first (lookup-inferior-packages inferior "guile-json"))
3223 (specification->package "guile")))
3226 On its first run, @command{guix package --manifest} might have to build the
3227 channel you specified before it can create the inferior; subsequent runs will
3228 be much faster because the Guix revision will be cached.
3230 The @code{(guix inferior)} module provides the following procedures to open an
3233 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
3234 [#:cache-directory] [#:ttl]
3235 Return an inferior for @var{channels}, a list of channels. Use the cache at
3236 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
3237 This procedure opens a new connection to the build daemon.
3239 As a side effect, this procedure may build or substitute binaries for
3240 @var{channels}, which can take time.
3243 @deffn {Scheme Procedure} open-inferior @var{directory} @
3244 [#:command "bin/guix"]
3245 Open the inferior Guix in @var{directory}, running
3246 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
3247 the inferior could not be launched.
3250 @cindex inferior packages
3251 The procedures listed below allow you to obtain and manipulate inferior
3254 @deffn {Scheme Procedure} inferior-packages @var{inferior}
3255 Return the list of packages known to @var{inferior}.
3258 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
3260 Return the sorted list of inferior packages matching @var{name} in
3261 @var{inferior}, with highest version numbers first. If @var{version} is true,
3262 return only packages with a version number prefixed by @var{version}.
3265 @deffn {Scheme Procedure} inferior-package? @var{obj}
3266 Return true if @var{obj} is an inferior package.
3269 @deffn {Scheme Procedure} inferior-package-name @var{package}
3270 @deffnx {Scheme Procedure} inferior-package-version @var{package}
3271 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
3272 @deffnx {Scheme Procedure} inferior-package-description @var{package}
3273 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
3274 @deffnx {Scheme Procedure} inferior-package-location @var{package}
3275 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
3276 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
3277 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
3278 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
3279 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
3280 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
3281 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
3282 These procedures are the counterpart of package record accessors
3283 (@pxref{package Reference}). Most of them work by querying the inferior
3284 @var{package} comes from, so the inferior must still be live when you call
3288 Inferior packages can be used transparently like any other package or
3289 file-like object in G-expressions (@pxref{G-Expressions}). They are also
3290 transparently handled by the @code{packages->manifest} procedure, which is
3291 commonly use in manifests (@pxref{Invoking guix package, the
3292 @option{--manifest} option of @command{guix package}}). Thus you can insert
3293 an inferior package pretty much anywhere you would insert a regular package:
3294 in manifests, in the @code{packages} field of your @code{operating-system}
3295 declaration, and so on.
3297 @node Invoking guix describe
3298 @section Invoking @command{guix describe}
3300 @cindex reproducibility
3301 @cindex replicating Guix
3302 Often you may want to answer questions like: ``Which revision of Guix am I
3303 using?'' or ``Which channels am I using?'' This is useful information in many
3304 situations: if you want to @emph{replicate} an environment on a different
3305 machine or user account, if you want to report a bug or to determine what
3306 change in the channels you are using caused it, or if you want to record your
3307 system state for reproducibility purposes. The @command{guix describe}
3308 command answers these questions.
3310 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
3311 displays the channel(s) that it was built from, including their repository URL
3312 and commit IDs (@pxref{Channels}):
3316 Generation 10 Sep 03 2018 17:32:44 (current)
3318 repository URL: https://git.savannah.gnu.org/git/guix.git
3320 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
3323 If you're familiar with the Git version control system, this is similar in
3324 spirit to @command{git describe}; the output is also similar to that of
3325 @command{guix pull --list-generations}, but limited to the current generation
3326 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
3327 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
3328 information is all it takes to describe the revision of Guix you're using, and
3329 also to replicate it.
3331 To make it easier to replicate Guix, @command{guix describe} can also be asked
3332 to return a list of channels instead of the human-readable description above:
3335 $ guix describe -f channels
3338 (url "https://git.savannah.gnu.org/git/guix.git")
3340 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
3344 You can save this to a file and feed it to @command{guix pull -C} on some
3345 other machine or at a later point in time, which will instantiate @emph{this
3346 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
3347 From there on, since you're able to deploy the same revision of Guix, you can
3348 just as well @emph{replicate a complete software environment}. We humbly
3349 think that this is @emph{awesome}, and we hope you'll like it too!
3351 The details of the options supported by @command{guix describe} are as
3355 @item --format=@var{format}
3356 @itemx -f @var{format}
3357 Produce output in the specified @var{format}, one of:
3361 produce human-readable output;
3363 produce a list of channel specifications that can be passed to @command{guix
3364 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
3368 produce a list of channel specifications in JSON format;
3370 produce a list of channel specifications in Recutils format.
3373 @item --profile=@var{profile}
3374 @itemx -p @var{profile}
3375 Display information about @var{profile}.
3378 @node Invoking guix pack
3379 @section Invoking @command{guix pack}
3381 Occasionally you want to pass software to people who are not (yet!)
3382 lucky enough to be using Guix. You'd tell them to run @command{guix
3383 package -i @var{something}}, but that's not possible in this case. This
3384 is where @command{guix pack} comes in.
3387 If you are looking for ways to exchange binaries among machines that
3388 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
3389 publish}, and @ref{Invoking guix archive}.
3394 @cindex application bundle
3395 @cindex software bundle
3396 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
3397 @dfn{software bundle}: it creates a tarball or some other archive
3398 containing the binaries of the software you're interested in, and all
3399 its dependencies. The resulting archive can be used on any machine that
3400 does not have Guix, and people can run the exact same binaries as those
3401 you have with Guix. The pack itself is created in a bit-reproducible
3402 fashion, so anyone can verify that it really contains the build results
3403 that you pretend to be shipping.
3405 For example, to create a bundle containing Guile, Emacs, Geiser, and all
3406 their dependencies, you can run:
3409 $ guix pack guile emacs geiser
3411 /gnu/store/@dots{}-pack.tar.gz
3414 The result here is a tarball containing a @file{/gnu/store} directory
3415 with all the relevant packages. The resulting tarball contains a
3416 @dfn{profile} with the three packages of interest; the profile is the
3417 same as would be created by @command{guix package -i}. It is this
3418 mechanism that is used to create Guix's own standalone binary tarball
3419 (@pxref{Binary Installation}).
3421 Users of this pack would have to run
3422 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
3423 find inconvenient. To work around it, you can create, say, a
3424 @file{/opt/gnu/bin} symlink to the profile:
3427 guix pack -S /opt/gnu/bin=bin guile emacs geiser
3431 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
3433 @cindex relocatable binaries, with @command{guix pack}
3434 What if the recipient of your pack does not have root privileges on
3435 their machine, and thus cannot unpack it in the root file system? In
3436 that case, you will want to use the @code{--relocatable} option (see
3437 below). This option produces @dfn{relocatable binaries}, meaning they
3438 they can be placed anywhere in the file system hierarchy: in the example
3439 above, users can unpack your tarball in their home directory and
3440 directly run @file{./opt/gnu/bin/guile}.
3442 @cindex Docker, build an image with guix pack
3443 Alternatively, you can produce a pack in the Docker image format using
3444 the following command:
3447 guix pack -f docker guile emacs geiser
3451 The result is a tarball that can be passed to the @command{docker load}
3453 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
3454 documentation} for more information.
3456 @cindex Singularity, build an image with guix pack
3457 @cindex SquashFS, build an image with guix pack
3458 Yet another option is to produce a SquashFS image with the following
3462 guix pack -f squashfs guile emacs geiser
3466 The result is a SquashFS file system image that can either be mounted or
3467 directly be used as a file system container image with the
3468 @uref{http://singularity.lbl.gov, Singularity container execution
3469 environment}, using commands like @command{singularity shell} or
3470 @command{singularity exec}.
3472 Several command-line options allow you to customize your pack:
3475 @item --format=@var{format}
3476 @itemx -f @var{format}
3477 Produce a pack in the given @var{format}.
3479 The available formats are:
3483 This is the default format. It produces a tarball containing all the
3484 specified binaries and symlinks.
3487 This produces a tarball that follows the
3488 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
3489 Docker Image Specification}.
3492 This produces a SquashFS image containing all the specified binaries and
3493 symlinks, as well as empty mount points for virtual file systems like
3499 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
3500 anywhere in the file system hierarchy and run from there. For example,
3501 if you create a pack containing Bash with:
3504 guix pack -R -S /mybin=bin bash
3508 ...@: you can copy that pack to a machine that lacks Guix, and from your
3509 home directory as a normal user, run:
3517 In that shell, if you type @code{ls /gnu/store}, you'll notice that
3518 @file{/gnu/store} shows up and contains all the dependencies of
3519 @code{bash}, even though the machine actually lacks @file{/gnu/store}
3520 altogether! That is probably the simplest way to deploy Guix-built
3521 software on a non-Guix machine.
3523 There's a gotcha though: this technique relies on the @dfn{user
3524 namespace} feature of the kernel Linux, which allows unprivileged users
3525 to mount or change root. Old versions of Linux did not support it, and
3526 some GNU/Linux distributions turn it off; on these systems, programs
3527 from the pack @emph{will fail to run}, unless they are unpacked in the
3530 @item --expression=@var{expr}
3531 @itemx -e @var{expr}
3532 Consider the package @var{expr} evaluates to.
3534 This has the same purpose as the same-named option in @command{guix
3535 build} (@pxref{Additional Build Options, @code{--expression} in
3536 @command{guix build}}).
3538 @item --manifest=@var{file}
3539 @itemx -m @var{file}
3540 Use the packages contained in the manifest object returned by the Scheme
3543 This has a similar purpose as the same-named option in @command{guix
3544 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
3545 same manifest files. It allows you to define a collection of packages
3546 once and use it both for creating profiles and for creating archives
3547 for use on machines that do not have Guix installed. Note that you can
3548 specify @emph{either} a manifest file @emph{or} a list of packages,
3551 @item --system=@var{system}
3552 @itemx -s @var{system}
3553 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3554 the system type of the build host.
3556 @item --target=@var{triplet}
3557 @cindex cross-compilation
3558 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
3559 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
3560 configuration triplets,, autoconf, Autoconf}).
3562 @item --compression=@var{tool}
3563 @itemx -C @var{tool}
3564 Compress the resulting tarball using @var{tool}---one of @code{gzip},
3565 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
3567 @item --symlink=@var{spec}
3568 @itemx -S @var{spec}
3569 Add the symlinks specified by @var{spec} to the pack. This option can
3570 appear several times.
3572 @var{spec} has the form @code{@var{source}=@var{target}}, where
3573 @var{source} is the symlink that will be created and @var{target} is the
3576 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
3577 symlink pointing to the @file{bin} sub-directory of the profile.
3579 @item --localstatedir
3580 @itemx --profile-name=@var{name}
3581 Include the ``local state directory'', @file{/var/guix}, in the resulting
3582 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
3583 profile---by default @var{name} is @code{guix-profile}, which corresponds to
3584 @file{~root/.guix-profile}.
3586 @file{/var/guix} contains the store database (@pxref{The Store}) as well
3587 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
3588 the pack means that the store is ``complete'' and manageable by Guix;
3589 not providing it pack means that the store is ``dead'': items cannot be
3590 added to it or removed from it after extraction of the pack.
3592 One use case for this is the Guix self-contained binary tarball
3593 (@pxref{Binary Installation}).
3596 Use the bootstrap binaries to build the pack. This option is only
3597 useful to Guix developers.
3600 In addition, @command{guix pack} supports all the common build options
3601 (@pxref{Common Build Options}) and all the package transformation
3602 options (@pxref{Package Transformation Options}).
3605 @node Invoking guix archive
3606 @section Invoking @command{guix archive}
3608 @cindex @command{guix archive}
3610 The @command{guix archive} command allows users to @dfn{export} files
3611 from the store into a single archive, and to later @dfn{import} them on
3612 a machine that runs Guix.
3613 In particular, it allows store files to be transferred from one machine
3614 to the store on another machine.
3617 If you're looking for a way to produce archives in a format suitable for
3618 tools other than Guix, @pxref{Invoking guix pack}.
3621 @cindex exporting store items
3622 To export store files as an archive to standard output, run:
3625 guix archive --export @var{options} @var{specifications}...
3628 @var{specifications} may be either store file names or package
3629 specifications, as for @command{guix package} (@pxref{Invoking guix
3630 package}). For instance, the following command creates an archive
3631 containing the @code{gui} output of the @code{git} package and the main
3632 output of @code{emacs}:
3635 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
3638 If the specified packages are not built yet, @command{guix archive}
3639 automatically builds them. The build process may be controlled with the
3640 common build options (@pxref{Common Build Options}).
3642 To transfer the @code{emacs} package to a machine connected over SSH,
3646 guix archive --export -r emacs | ssh the-machine guix archive --import
3650 Similarly, a complete user profile may be transferred from one machine
3651 to another like this:
3654 guix archive --export -r $(readlink -f ~/.guix-profile) | \
3655 ssh the-machine guix-archive --import
3659 However, note that, in both examples, all of @code{emacs} and the
3660 profile as well as all of their dependencies are transferred (due to
3661 @code{-r}), regardless of what is already available in the store on the
3662 target machine. The @code{--missing} option can help figure out which
3663 items are missing from the target store. The @command{guix copy}
3664 command simplifies and optimizes this whole process, so this is probably
3665 what you should use in this case (@pxref{Invoking guix copy}).
3667 @cindex nar, archive format
3668 @cindex normalized archive (nar)
3669 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
3670 comparable in spirit to `tar', but with differences
3671 that make it more appropriate for our purposes. First, rather than
3672 recording all Unix metadata for each file, the nar format only mentions
3673 the file type (regular, directory, or symbolic link); Unix permissions
3674 and owner/group are dismissed. Second, the order in which directory
3675 entries are stored always follows the order of file names according to
3676 the C locale collation order. This makes archive production fully
3679 When exporting, the daemon digitally signs the contents of the archive,
3680 and that digital signature is appended. When importing, the daemon
3681 verifies the signature and rejects the import in case of an invalid
3682 signature or if the signing key is not authorized.
3683 @c FIXME: Add xref to daemon doc about signatures.
3685 The main options are:
3689 Export the specified store files or packages (see below.) Write the
3690 resulting archive to the standard output.
3692 Dependencies are @emph{not} included in the output, unless
3693 @code{--recursive} is passed.
3697 When combined with @code{--export}, this instructs @command{guix
3698 archive} to include dependencies of the given items in the archive.
3699 Thus, the resulting archive is self-contained: it contains the closure
3700 of the exported store items.
3703 Read an archive from the standard input, and import the files listed
3704 therein into the store. Abort if the archive has an invalid digital
3705 signature, or if it is signed by a public key not among the authorized
3706 keys (see @code{--authorize} below.)
3709 Read a list of store file names from the standard input, one per line,
3710 and write on the standard output the subset of these files missing from
3713 @item --generate-key[=@var{parameters}]
3714 @cindex signing, archives
3715 Generate a new key pair for the daemon. This is a prerequisite before
3716 archives can be exported with @code{--export}. Note that this operation
3717 usually takes time, because it needs to gather enough entropy to
3718 generate the key pair.
3720 The generated key pair is typically stored under @file{/etc/guix}, in
3721 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
3722 key, which must be kept secret.) When @var{parameters} is omitted,
3723 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
3724 versions before 1.6.0, it is a 4096-bit RSA key.
3725 Alternatively, @var{parameters} can specify
3726 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
3727 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
3728 Libgcrypt Reference Manual}).
3731 @cindex authorizing, archives
3732 Authorize imports signed by the public key passed on standard input.
3733 The public key must be in ``s-expression advanced format''---i.e., the
3734 same format as the @file{signing-key.pub} file.
3736 The list of authorized keys is kept in the human-editable file
3737 @file{/etc/guix/acl}. The file contains
3738 @url{http://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
3739 s-expressions''} and is structured as an access-control list in the
3740 @url{http://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
3743 @item --extract=@var{directory}
3744 @itemx -x @var{directory}
3745 Read a single-item archive as served by substitute servers
3746 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
3747 low-level operation needed in only very narrow use cases; see below.
3749 For example, the following command extracts the substitute for Emacs
3750 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
3754 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
3755 | bunzip2 | guix archive -x /tmp/emacs
3758 Single-item archives are different from multiple-item archives produced
3759 by @command{guix archive --export}; they contain a single store item,
3760 and they do @emph{not} embed a signature. Thus this operation does
3761 @emph{no} signature verification and its output should be considered
3764 The primary purpose of this operation is to facilitate inspection of
3765 archive contents coming from possibly untrusted substitute servers.
3769 @c *********************************************************************
3770 @node Programming Interface
3771 @chapter Programming Interface
3773 GNU Guix provides several Scheme programming interfaces (APIs) to
3774 define, build, and query packages. The first interface allows users to
3775 write high-level package definitions. These definitions refer to
3776 familiar packaging concepts, such as the name and version of a package,
3777 its build system, and its dependencies. These definitions can then be
3778 turned into concrete build actions.
3780 Build actions are performed by the Guix daemon, on behalf of users. In a
3781 standard setup, the daemon has write access to the store---the
3782 @file{/gnu/store} directory---whereas users do not. The recommended
3783 setup also has the daemon perform builds in chroots, under a specific
3784 build users, to minimize interference with the rest of the system.
3787 Lower-level APIs are available to interact with the daemon and the
3788 store. To instruct the daemon to perform a build action, users actually
3789 provide it with a @dfn{derivation}. A derivation is a low-level
3790 representation of the build actions to be taken, and the environment in
3791 which they should occur---derivations are to package definitions what
3792 assembly is to C programs. The term ``derivation'' comes from the fact
3793 that build results @emph{derive} from them.
3795 This chapter describes all these APIs in turn, starting from high-level
3796 package definitions.
3799 * Defining Packages:: Defining new packages.
3800 * Build Systems:: Specifying how packages are built.
3801 * The Store:: Manipulating the package store.
3802 * Derivations:: Low-level interface to package derivations.
3803 * The Store Monad:: Purely functional interface to the store.
3804 * G-Expressions:: Manipulating build expressions.
3805 * Invoking guix repl:: Fiddling with Guix interactively.
3808 @node Defining Packages
3809 @section Defining Packages
3811 The high-level interface to package definitions is implemented in the
3812 @code{(guix packages)} and @code{(guix build-system)} modules. As an
3813 example, the package definition, or @dfn{recipe}, for the GNU Hello
3814 package looks like this:
3817 (define-module (gnu packages hello)
3818 #:use-module (guix packages)
3819 #:use-module (guix download)
3820 #:use-module (guix build-system gnu)
3821 #:use-module (guix licenses)
3822 #:use-module (gnu packages gawk))
3824 (define-public hello
3830 (uri (string-append "mirror://gnu/hello/hello-" version
3834 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
3835 (build-system gnu-build-system)
3836 (arguments '(#:configure-flags '("--enable-silent-rules")))
3837 (inputs `(("gawk" ,gawk)))
3838 (synopsis "Hello, GNU world: An example GNU package")
3839 (description "Guess what GNU Hello prints!")
3840 (home-page "http://www.gnu.org/software/hello/")
3845 Without being a Scheme expert, the reader may have guessed the meaning
3846 of the various fields here. This expression binds the variable
3847 @code{hello} to a @code{<package>} object, which is essentially a record
3848 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
3849 This package object can be inspected using procedures found in the
3850 @code{(guix packages)} module; for instance, @code{(package-name hello)}
3851 returns---surprise!---@code{"hello"}.
3853 With luck, you may be able to import part or all of the definition of
3854 the package you are interested in from another repository, using the
3855 @code{guix import} command (@pxref{Invoking guix import}).
3857 In the example above, @var{hello} is defined in a module of its own,
3858 @code{(gnu packages hello)}. Technically, this is not strictly
3859 necessary, but it is convenient to do so: all the packages defined in
3860 modules under @code{(gnu packages @dots{})} are automatically known to
3861 the command-line tools (@pxref{Package Modules}).
3863 There are a few points worth noting in the above package definition:
3867 The @code{source} field of the package is an @code{<origin>} object
3868 (@pxref{origin Reference}, for the complete reference).
3869 Here, the @code{url-fetch} method from @code{(guix download)} is used,
3870 meaning that the source is a file to be downloaded over FTP or HTTP.
3872 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
3873 the GNU mirrors defined in @code{(guix download)}.
3875 The @code{sha256} field specifies the expected SHA256 hash of the file
3876 being downloaded. It is mandatory, and allows Guix to check the
3877 integrity of the file. The @code{(base32 @dots{})} form introduces the
3878 base32 representation of the hash. You can obtain this information with
3879 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
3880 hash} (@pxref{Invoking guix hash}).
3883 When needed, the @code{origin} form can also have a @code{patches} field
3884 listing patches to be applied, and a @code{snippet} field giving a
3885 Scheme expression to modify the source code.
3888 @cindex GNU Build System
3889 The @code{build-system} field specifies the procedure to build the
3890 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
3891 represents the familiar GNU Build System, where packages may be
3892 configured, built, and installed with the usual @code{./configure &&
3893 make && make check && make install} command sequence.
3896 The @code{arguments} field specifies options for the build system
3897 (@pxref{Build Systems}). Here it is interpreted by
3898 @var{gnu-build-system} as a request run @file{configure} with the
3899 @code{--enable-silent-rules} flag.
3905 What about these quote (@code{'}) characters? They are Scheme syntax to
3906 introduce a literal list; @code{'} is synonymous with @code{quote}.
3907 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
3908 for details. Here the value of the @code{arguments} field is a list of
3909 arguments passed to the build system down the road, as with @code{apply}
3910 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
3913 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
3914 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
3915 @code{#:configure-flags} is a keyword used to pass a keyword argument
3916 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
3920 The @code{inputs} field specifies inputs to the build process---i.e.,
3921 build-time or run-time dependencies of the package. Here, we define an
3922 input called @code{"gawk"} whose value is that of the @var{gawk}
3923 variable; @var{gawk} is itself bound to a @code{<package>} object.
3925 @cindex backquote (quasiquote)
3928 @cindex comma (unquote)
3932 @findex unquote-splicing
3933 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
3934 us to introduce a literal list in the @code{inputs} field, while
3935 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
3936 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
3939 Note that GCC, Coreutils, Bash, and other essential tools do not need to
3940 be specified as inputs here. Instead, @var{gnu-build-system} takes care
3941 of ensuring that they are present (@pxref{Build Systems}).
3943 However, any other dependencies need to be specified in the
3944 @code{inputs} field. Any dependency not specified here will simply be
3945 unavailable to the build process, possibly leading to a build failure.
3948 @xref{package Reference}, for a full description of possible fields.
3950 Once a package definition is in place, the
3951 package may actually be built using the @code{guix build} command-line
3952 tool (@pxref{Invoking guix build}), troubleshooting any build failures
3953 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
3954 package definition using the @command{guix edit} command
3955 (@pxref{Invoking guix edit}).
3956 @xref{Packaging Guidelines}, for
3957 more information on how to test package definitions, and
3958 @ref{Invoking guix lint}, for information on how to check a definition
3959 for style conformance.
3960 @vindex GUIX_PACKAGE_PATH
3961 Lastly, @pxref{Channels}, for information
3962 on how to extend the distribution by adding your own package definitions
3965 Finally, updating the package definition to a new upstream version
3966 can be partly automated by the @command{guix refresh} command
3967 (@pxref{Invoking guix refresh}).
3969 Behind the scenes, a derivation corresponding to the @code{<package>}
3970 object is first computed by the @code{package-derivation} procedure.
3971 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
3972 The build actions it prescribes may then be realized by using the
3973 @code{build-derivations} procedure (@pxref{The Store}).
3975 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
3976 Return the @code{<derivation>} object of @var{package} for @var{system}
3977 (@pxref{Derivations}).
3979 @var{package} must be a valid @code{<package>} object, and @var{system}
3980 must be a string denoting the target system type---e.g.,
3981 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
3982 must be a connection to the daemon, which operates on the store
3983 (@pxref{The Store}).
3987 @cindex cross-compilation
3988 Similarly, it is possible to compute a derivation that cross-builds a
3989 package for some other system:
3991 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
3992 @var{package} @var{target} [@var{system}]
3993 Return the @code{<derivation>} object of @var{package} cross-built from
3994 @var{system} to @var{target}.
3996 @var{target} must be a valid GNU triplet denoting the target hardware
3997 and operating system, such as @code{"mips64el-linux-gnu"}
3998 (@pxref{Configuration Names, GNU configuration triplets,, configure, GNU
3999 Configure and Build System}).
4002 @cindex package transformations
4003 @cindex input rewriting
4004 @cindex dependency tree rewriting
4005 Packages can be manipulated in arbitrary ways. An example of a useful
4006 transformation is @dfn{input rewriting}, whereby the dependency tree of
4007 a package is rewritten by replacing specific inputs by others:
4009 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
4010 [@var{rewrite-name}]
4011 Return a procedure that, when passed a package, replaces its direct and
4012 indirect dependencies (but not its implicit inputs) according to
4013 @var{replacements}. @var{replacements} is a list of package pairs; the
4014 first element of each pair is the package to replace, and the second one
4017 Optionally, @var{rewrite-name} is a one-argument procedure that takes
4018 the name of a package and returns its new name after rewrite.
4022 Consider this example:
4025 (define libressl-instead-of-openssl
4026 ;; This is a procedure to replace OPENSSL by LIBRESSL,
4028 (package-input-rewriting `((,openssl . ,libressl))))
4030 (define git-with-libressl
4031 (libressl-instead-of-openssl git))
4035 Here we first define a rewriting procedure that replaces @var{openssl}
4036 with @var{libressl}. Then we use it to define a @dfn{variant} of the
4037 @var{git} package that uses @var{libressl} instead of @var{openssl}.
4038 This is exactly what the @option{--with-input} command-line option does
4039 (@pxref{Package Transformation Options, @option{--with-input}}).
4041 A more generic procedure to rewrite a package dependency graph is
4042 @code{package-mapping}: it supports arbitrary changes to nodes in the
4045 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
4046 Return a procedure that, given a package, applies @var{proc} to all the packages
4047 depended on and returns the resulting package. The procedure stops recursion
4048 when @var{cut?} returns true for a given package.
4052 * package Reference:: The package data type.
4053 * origin Reference:: The origin data type.
4057 @node package Reference
4058 @subsection @code{package} Reference
4060 This section summarizes all the options available in @code{package}
4061 declarations (@pxref{Defining Packages}).
4063 @deftp {Data Type} package
4064 This is the data type representing a package recipe.
4068 The name of the package, as a string.
4070 @item @code{version}
4071 The version of the package, as a string.
4074 An object telling how the source code for the package should be
4075 acquired. Most of the time, this is an @code{origin} object, which
4076 denotes a file fetched from the Internet (@pxref{origin Reference}). It
4077 can also be any other ``file-like'' object such as a @code{local-file},
4078 which denotes a file from the local file system (@pxref{G-Expressions,
4079 @code{local-file}}).
4081 @item @code{build-system}
4082 The build system that should be used to build the package (@pxref{Build
4085 @item @code{arguments} (default: @code{'()})
4086 The arguments that should be passed to the build system. This is a
4087 list, typically containing sequential keyword-value pairs.
4089 @item @code{inputs} (default: @code{'()})
4090 @itemx @code{native-inputs} (default: @code{'()})
4091 @itemx @code{propagated-inputs} (default: @code{'()})
4092 @cindex inputs, of packages
4093 These fields list dependencies of the package. Each one is a list of
4094 tuples, where each tuple has a label for the input (a string) as its
4095 first element, a package, origin, or derivation as its second element,
4096 and optionally the name of the output thereof that should be used, which
4097 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
4098 more on package outputs). For example, the list below specifies three
4102 `(("libffi" ,libffi)
4103 ("libunistring" ,libunistring)
4104 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
4107 @cindex cross compilation, package dependencies
4108 The distinction between @code{native-inputs} and @code{inputs} is
4109 necessary when considering cross-compilation. When cross-compiling,
4110 dependencies listed in @code{inputs} are built for the @emph{target}
4111 architecture; conversely, dependencies listed in @code{native-inputs}
4112 are built for the architecture of the @emph{build} machine.
4114 @code{native-inputs} is typically used to list tools needed at
4115 build time, but not at run time, such as Autoconf, Automake, pkg-config,
4116 Gettext, or Bison. @command{guix lint} can report likely mistakes in
4117 this area (@pxref{Invoking guix lint}).
4119 @anchor{package-propagated-inputs}
4120 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
4121 specified packages will be automatically installed alongside the package
4122 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
4123 package}}, for information on how @command{guix package} deals with
4126 For example this is necessary when a C/C++ library needs headers of
4127 another library to compile, or when a pkg-config file refers to another
4128 one @i{via} its @code{Requires} field.
4130 Another example where @code{propagated-inputs} is useful is for languages
4131 that lack a facility to record the run-time search path akin to the
4132 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
4133 more. To ensure that libraries written in those languages can find
4134 library code they depend on at run time, run-time dependencies must be
4135 listed in @code{propagated-inputs} rather than @code{inputs}.
4137 @item @code{self-native-input?} (default: @code{#f})
4138 This is a Boolean field telling whether the package should use itself as
4139 a native input when cross-compiling.
4141 @item @code{outputs} (default: @code{'("out")})
4142 The list of output names of the package. @xref{Packages with Multiple
4143 Outputs}, for typical uses of additional outputs.
4145 @item @code{native-search-paths} (default: @code{'()})
4146 @itemx @code{search-paths} (default: @code{'()})
4147 A list of @code{search-path-specification} objects describing
4148 search-path environment variables honored by the package.
4150 @item @code{replacement} (default: @code{#f})
4151 This must be either @code{#f} or a package object that will be used as a
4152 @dfn{replacement} for this package. @xref{Security Updates, grafts},
4155 @item @code{synopsis}
4156 A one-line description of the package.
4158 @item @code{description}
4159 A more elaborate description of the package.
4161 @item @code{license}
4162 @cindex license, of packages
4163 The license of the package; a value from @code{(guix licenses)},
4164 or a list of such values.
4166 @item @code{home-page}
4167 The URL to the home-page of the package, as a string.
4169 @item @code{supported-systems} (default: @var{%supported-systems})
4170 The list of systems supported by the package, as strings of the form
4171 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
4173 @item @code{maintainers} (default: @code{'()})
4174 The list of maintainers of the package, as @code{maintainer} objects.
4176 @item @code{location} (default: source location of the @code{package} form)
4177 The source location of the package. It is useful to override this when
4178 inheriting from another package, in which case this field is not
4179 automatically corrected.
4184 @node origin Reference
4185 @subsection @code{origin} Reference
4187 This section summarizes all the options available in @code{origin}
4188 declarations (@pxref{Defining Packages}).
4190 @deftp {Data Type} origin
4191 This is the data type representing a source code origin.
4195 An object containing the URI of the source. The object type depends on
4196 the @code{method} (see below). For example, when using the
4197 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
4198 values are: a URL represented as a string, or a list thereof.
4201 A procedure that handles the URI.
4206 @item @var{url-fetch} from @code{(guix download)}
4207 download a file from the HTTP, HTTPS, or FTP URL specified in the
4211 @item @var{git-fetch} from @code{(guix git-download)}
4212 clone the Git version control repository, and check out the revision
4213 specified in the @code{uri} field as a @code{git-reference} object; a
4214 @code{git-reference} looks like this:
4218 (url "git://git.debian.org/git/pkg-shadow/shadow")
4219 (commit "v4.1.5.1"))
4224 A bytevector containing the SHA-256 hash of the source. Typically the
4225 @code{base32} form is used here to generate the bytevector from a
4228 You can obtain this information using @code{guix download}
4229 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
4232 @item @code{file-name} (default: @code{#f})
4233 The file name under which the source code should be saved. When this is
4234 @code{#f}, a sensible default value will be used in most cases. In case
4235 the source is fetched from a URL, the file name from the URL will be
4236 used. For version control checkouts, it is recommended to provide the
4237 file name explicitly because the default is not very descriptive.
4239 @item @code{patches} (default: @code{'()})
4240 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
4241 file-like objects}) pointing to patches to be applied to the source.
4243 This list of patches must be unconditional. In particular, it cannot
4244 depend on the value of @code{%current-system} or
4245 @code{%current-target-system}.
4247 @item @code{snippet} (default: @code{#f})
4248 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
4249 in the source directory. This is a convenient way to modify the source,
4250 sometimes more convenient than a patch.
4252 @item @code{patch-flags} (default: @code{'("-p1")})
4253 A list of command-line flags that should be passed to the @code{patch}
4256 @item @code{patch-inputs} (default: @code{#f})
4257 Input packages or derivations to the patching process. When this is
4258 @code{#f}, the usual set of inputs necessary for patching are provided,
4259 such as GNU@tie{}Patch.
4261 @item @code{modules} (default: @code{'()})
4262 A list of Guile modules that should be loaded during the patching
4263 process and while running the code in the @code{snippet} field.
4265 @item @code{patch-guile} (default: @code{#f})
4266 The Guile package that should be used in the patching process. When
4267 this is @code{#f}, a sensible default is used.
4273 @section Build Systems
4275 @cindex build system
4276 Each package definition specifies a @dfn{build system} and arguments for
4277 that build system (@pxref{Defining Packages}). This @code{build-system}
4278 field represents the build procedure of the package, as well as implicit
4279 dependencies of that build procedure.
4281 Build systems are @code{<build-system>} objects. The interface to
4282 create and manipulate them is provided by the @code{(guix build-system)}
4283 module, and actual build systems are exported by specific modules.
4285 @cindex bag (low-level package representation)
4286 Under the hood, build systems first compile package objects to
4287 @dfn{bags}. A @dfn{bag} is like a package, but with less
4288 ornamentation---in other words, a bag is a lower-level representation of
4289 a package, which includes all the inputs of that package, including some
4290 that were implicitly added by the build system. This intermediate
4291 representation is then compiled to a derivation (@pxref{Derivations}).
4293 Build systems accept an optional list of @dfn{arguments}. In package
4294 definitions, these are passed @i{via} the @code{arguments} field
4295 (@pxref{Defining Packages}). They are typically keyword arguments
4296 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
4297 Guile Reference Manual}). The value of these arguments is usually
4298 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
4299 by the daemon (@pxref{Derivations}).
4301 The main build system is @var{gnu-build-system}, which implements the
4302 standard build procedure for GNU and many other packages. It
4303 is provided by the @code{(guix build-system gnu)} module.
4305 @defvr {Scheme Variable} gnu-build-system
4306 @var{gnu-build-system} represents the GNU Build System, and variants
4307 thereof (@pxref{Configuration, configuration and makefile conventions,,
4308 standards, GNU Coding Standards}).
4310 @cindex build phases
4311 In a nutshell, packages using it are configured, built, and installed with
4312 the usual @code{./configure && make && make check && make install}
4313 command sequence. In practice, a few additional steps are often needed.
4314 All these steps are split up in separate @dfn{phases},
4315 notably@footnote{Please see the @code{(guix build gnu-build-system)}
4316 modules for more details about the build phases.}:
4320 Unpack the source tarball, and change the current directory to the
4321 extracted source tree. If the source is actually a directory, copy it
4322 to the build tree, and enter that directory.
4324 @item patch-source-shebangs
4325 Patch shebangs encountered in source files so they refer to the right
4326 store file names. For instance, this changes @code{#!/bin/sh} to
4327 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
4330 Run the @file{configure} script with a number of default options, such
4331 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
4332 by the @code{#:configure-flags} argument.
4335 Run @code{make} with the list of flags specified with
4336 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
4337 (the default), build with @code{make -j}.
4340 Run @code{make check}, or some other target specified with
4341 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
4342 @code{#:parallel-tests?} argument is true (the default), run @code{make
4346 Run @code{make install} with the flags listed in @code{#:make-flags}.
4348 @item patch-shebangs
4349 Patch shebangs on the installed executable files.
4352 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
4353 is false), copying them to the @code{debug} output when available
4354 (@pxref{Installing Debugging Files}).
4357 @vindex %standard-phases
4358 The build-side module @code{(guix build gnu-build-system)} defines
4359 @var{%standard-phases} as the default list of build phases.
4360 @var{%standard-phases} is a list of symbol/procedure pairs, where the
4361 procedure implements the actual phase.
4363 The list of phases used for a particular package can be changed with the
4364 @code{#:phases} parameter. For instance, passing:
4367 #:phases (modify-phases %standard-phases (delete 'configure))
4370 means that all the phases described above will be used, except the
4371 @code{configure} phase.
4373 In addition, this build system ensures that the ``standard'' environment
4374 for GNU packages is available. This includes tools such as GCC, libc,
4375 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
4376 build-system gnu)} module for a complete list). We call these the
4377 @dfn{implicit inputs} of a package, because package definitions do not
4378 have to mention them.
4381 Other @code{<build-system>} objects are defined to support other
4382 conventions and tools used by free software packages. They inherit most
4383 of @var{gnu-build-system}, and differ mainly in the set of inputs
4384 implicitly added to the build process, and in the list of phases
4385 executed. Some of these build systems are listed below.
4387 @defvr {Scheme Variable} ant-build-system
4388 This variable is exported by @code{(guix build-system ant)}. It
4389 implements the build procedure for Java packages that can be built with
4390 @url{http://ant.apache.org/, Ant build tool}.
4392 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
4393 provided by the @code{icedtea} package to the set of inputs. Different
4394 packages can be specified with the @code{#:ant} and @code{#:jdk}
4395 parameters, respectively.
4397 When the original package does not provide a suitable Ant build file,
4398 the parameter @code{#:jar-name} can be used to generate a minimal Ant
4399 build file @file{build.xml} with tasks to build the specified jar
4400 archive. In this case the parameter @code{#:source-dir} can be used to
4401 specify the source sub-directory, defaulting to ``src''.
4403 The @code{#:main-class} parameter can be used with the minimal ant
4404 buildfile to specify the main class of the resulting jar. This makes the
4405 jar file executable. The @code{#:test-include} parameter can be used to
4406 specify the list of junit tests to run. It defaults to
4407 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
4408 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
4409 because abstract classes cannot be run as tests.
4411 The parameter @code{#:build-target} can be used to specify the Ant task
4412 that should be run during the @code{build} phase. By default the
4413 ``jar'' task will be run.
4417 @defvr {Scheme Variable} android-ndk-build-system
4418 @cindex Android distribution
4419 @cindex Android NDK build system
4420 This variable is exported by @code{(guix build-system android-ndk)}. It
4421 implements a build procedure for Android NDK (native development kit)
4422 packages using a Guix-specific build process.
4424 The build system assumes that packages install their public interface
4425 (header) files to the subdirectory "include" of the "out" output and
4426 their libraries to the subdirectory "lib" of the "out" output.
4428 It's also assumed that the union of all the dependencies of a package
4429 has no conflicting files.
4431 For the time being, cross-compilation is not supported - so right now
4432 the libraries and header files are assumed to be host tools.
4436 @defvr {Scheme Variable} asdf-build-system/source
4437 @defvrx {Scheme Variable} asdf-build-system/sbcl
4438 @defvrx {Scheme Variable} asdf-build-system/ecl
4440 These variables, exported by @code{(guix build-system asdf)}, implement
4441 build procedures for Common Lisp packages using
4442 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
4443 definition facility for Common Lisp programs and libraries.
4445 The @code{asdf-build-system/source} system installs the packages in
4446 source form, and can be loaded using any common lisp implementation, via
4447 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
4448 systems in the format which a particular implementation understands.
4449 These build systems can also be used to produce executable programs, or
4450 lisp images which contain a set of packages pre-loaded.
4452 The build system uses naming conventions. For binary packages, the
4453 package name should be prefixed with the lisp implementation, such as
4454 @code{sbcl-} for @code{asdf-build-system/sbcl}.
4456 Additionally, the corresponding source package should be labeled using
4457 the same convention as python packages (see @ref{Python Modules}), using
4458 the @code{cl-} prefix.
4460 For binary packages, each system should be defined as a Guix package.
4461 If one package @code{origin} contains several systems, package variants
4462 can be created in order to build all the systems. Source packages,
4463 which use @code{asdf-build-system/source}, may contain several systems.
4465 In order to create executable programs and images, the build-side
4466 procedures @code{build-program} and @code{build-image} can be used.
4467 They should be called in a build phase after the @code{create-symlinks}
4468 phase, so that the system which was just built can be used within the
4469 resulting image. @code{build-program} requires a list of Common Lisp
4470 expressions to be passed as the @code{#:entry-program} argument.
4472 If the system is not defined within its own @code{.asd} file of the same
4473 name, then the @code{#:asd-file} parameter should be used to specify
4474 which file the system is defined in. Furthermore, if the package
4475 defines a system for its tests in a separate file, it will be loaded
4476 before the tests are run if it is specified by the
4477 @code{#:test-asd-file} parameter. If it is not set, the files
4478 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
4479 and @code{test.asd} will be tried if they exist.
4481 If for some reason the package must be named in a different way than the
4482 naming conventions suggest, the @code{#:asd-system-name} parameter can
4483 be used to specify the name of the system.
4487 @defvr {Scheme Variable} cargo-build-system
4488 @cindex Rust programming language
4489 @cindex Cargo (Rust build system)
4490 This variable is exported by @code{(guix build-system cargo)}. It
4491 supports builds of packages using Cargo, the build tool of the
4492 @uref{https://www.rust-lang.org, Rust programming language}.
4494 In its @code{configure} phase, this build system replaces dependencies
4495 specified in the @file{Carto.toml} file with inputs to the Guix package.
4496 The @code{install} phase installs the binaries, and it also installs the
4497 source code and @file{Cargo.toml} file.
4500 @cindex Clojure (programming language)
4501 @cindex simple Clojure build system
4502 @defvr {Scheme Variable} clojure-build-system
4503 This variable is exported by @code{(guix build-system clojure)}. It implements
4504 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
4505 using plain old @code{compile} in Clojure. Cross-compilation is not supported
4508 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
4509 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
4510 @code{#:zip} parameters, respectively.
4512 A list of source directories, test directories and jar names can be specified
4513 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
4514 parameters, respectively. Compile directory and main class can be specified
4515 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
4516 Other parameters are documented below.
4518 This build system is an extension of @var{ant-build-system}, but with the
4519 following phases changed:
4524 This phase calls @code{compile} in Clojure to compile source files and runs
4525 @command{jar} to create jars from both source files and compiled files
4526 according to the include list and exclude list specified in
4527 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
4528 has priority over the include list. These lists consist of symbols
4529 representing Clojure libraries or the special keyword @code{#:all} representing
4530 all Clojure libraries found under the source directories. The parameter
4531 @code{#:omit-source?} decides if source should be included into the jars.
4534 This phase runs tests according to the include list and exclude list specified
4535 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
4536 meanings are analogous to that of @code{#:aot-include} and
4537 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
4538 stands for all Clojure libraries found under the test directories. The
4539 parameter @code{#:tests?} decides if tests should be run.
4542 This phase installs all jars built previously.
4545 Apart from the above, this build system also contains an additional phase:
4550 This phase installs all top-level files with base name matching
4551 @var{%doc-regex}. A different regex can be specified with the
4552 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
4553 directories specified in @code{#:doc-dirs} are installed as well.
4557 @defvr {Scheme Variable} cmake-build-system
4558 This variable is exported by @code{(guix build-system cmake)}. It
4559 implements the build procedure for packages using the
4560 @url{http://www.cmake.org, CMake build tool}.
4562 It automatically adds the @code{cmake} package to the set of inputs.
4563 Which package is used can be specified with the @code{#:cmake}
4566 The @code{#:configure-flags} parameter is taken as a list of flags
4567 passed to the @command{cmake} command. The @code{#:build-type}
4568 parameter specifies in abstract terms the flags passed to the compiler;
4569 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
4570 debugging information''), which roughly means that code is compiled with
4571 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
4574 @defvr {Scheme Variable} dune-build-system
4575 This variable is exported by @code{(guix build-system dune)}. It
4576 supports builds of packages using @uref{https://dune.build/, Dune}, a build
4577 tool for the OCaml programming language. It is implemented as an extension
4578 of the @code{ocaml-build-system} which is described below. As such, the
4579 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
4582 It automatically adds the @code{dune} package to the set of inputs.
4583 Which package is used can be specified with the @code{#:dune}
4586 There is no @code{configure} phase because dune packages typically don't
4587 need to be configured. The @code{#:build-flags} parameter is taken as a
4588 list of flags passed to the @code{dune} command during the build.
4590 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
4591 command instead of the more recent @code{dune} command while building
4592 a package. Its default value is @code{#f}.
4595 @defvr {Scheme Variable} go-build-system
4596 This variable is exported by @code{(guix build-system go)}. It
4597 implements a build procedure for Go packages using the standard
4598 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
4599 Go build mechanisms}.
4601 The user is expected to provide a value for the key @code{#:import-path}
4602 and, in some cases, @code{#:unpack-path}. The
4603 @url{https://golang.org/doc/code.html#ImportPaths, import path}
4604 corresponds to the file system path expected by the package's build
4605 scripts and any referring packages, and provides a unique way to
4606 refer to a Go package. It is typically based on a combination of the
4607 package source code's remote URI and file system hierarchy structure. In
4608 some cases, you will need to unpack the package's source code to a
4609 different directory structure than the one indicated by the import path,
4610 and @code{#:unpack-path} should be used in such cases.
4612 Packages that provide Go libraries should be installed along with their
4613 source code. The key @code{#:install-source?}, which defaults to
4614 @code{#t}, controls whether or not the source code is installed. It can
4615 be set to @code{#f} for packages that only provide executable files.
4618 @defvr {Scheme Variable} glib-or-gtk-build-system
4619 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
4620 is intended for use with packages making use of GLib or GTK+.
4622 This build system adds the following two phases to the ones defined by
4623 @var{gnu-build-system}:
4626 @item glib-or-gtk-wrap
4627 The phase @code{glib-or-gtk-wrap} ensures that programs in
4628 @file{bin/} are able to find GLib ``schemas'' and
4629 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
4630 modules}. This is achieved by wrapping the programs in launch scripts
4631 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
4632 environment variables.
4634 It is possible to exclude specific package outputs from that wrapping
4635 process by listing their names in the
4636 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
4637 when an output is known not to contain any GLib or GTK+ binaries, and
4638 where wrapping would gratuitously add a dependency of that output on
4641 @item glib-or-gtk-compile-schemas
4642 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
4643 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
4644 GSettings schemas} of GLib are compiled. Compilation is performed by the
4645 @command{glib-compile-schemas} program. It is provided by the package
4646 @code{glib:bin} which is automatically imported by the build system.
4647 The @code{glib} package providing @command{glib-compile-schemas} can be
4648 specified with the @code{#:glib} parameter.
4651 Both phases are executed after the @code{install} phase.
4654 @defvr {Scheme Variable} guile-build-system
4655 This build system is for Guile packages that consist exclusively of Scheme
4656 code and that are so lean that they don't even have a makefile, let alone a
4657 @file{configure} script. It compiles Scheme code using @command{guild
4658 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
4659 installs the @file{.scm} and @file{.go} files in the right place. It also
4660 installs documentation.
4662 This build system supports cross-compilation by using the @code{--target}
4663 option of @command{guild compile}.
4665 Packages built with @code{guile-build-system} must provide a Guile package in
4666 their @code{native-inputs} field.
4669 @defvr {Scheme Variable} minify-build-system
4670 This variable is exported by @code{(guix build-system minify)}. It
4671 implements a minification procedure for simple JavaScript packages.
4673 It adds @code{uglify-js} to the set of inputs and uses it to compress
4674 all JavaScript files in the @file{src} directory. A different minifier
4675 package can be specified with the @code{#:uglify-js} parameter, but it
4676 is expected that the package writes the minified code to the standard
4679 When the input JavaScript files are not all located in the @file{src}
4680 directory, the parameter @code{#:javascript-files} can be used to
4681 specify a list of file names to feed to the minifier.
4684 @defvr {Scheme Variable} ocaml-build-system
4685 This variable is exported by @code{(guix build-system ocaml)}. It implements
4686 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
4687 of choosing the correct set of commands to run for each package. OCaml
4688 packages can expect many different commands to be run. This build system will
4691 When the package has a @file{setup.ml} file present at the top-level, it will
4692 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
4693 @code{ocaml setup.ml -install}. The build system will assume that this file
4694 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
4695 care of setting the prefix and enabling tests if they are not disabled. You
4696 can pass configure and build flags with the @code{#:configure-flags} and
4697 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
4698 set of flags used to enable tests. The @code{#:use-make?} key can be used to
4699 bypass this system in the build and install phases.
4701 When the package has a @file{configure} file, it is assumed that it is a
4702 hand-made configure script that requires a different argument format than
4703 in the @code{gnu-build-system}. You can add more flags with the
4704 @code{#:configure-flags} key.
4706 When the package has a @file{Makefile} file (or @code{#:use-make?} is
4707 @code{#t}), it will be used and more flags can be passed to the build and
4708 install phases with the @code{#:make-flags} key.
4710 Finally, some packages do not have these files and use a somewhat standard
4711 location for its build system. In that case, the build system will run
4712 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
4713 providing the path to the required findlib module. Additional flags can
4714 be passed via the @code{#:build-flags} key. Install is taken care of by
4715 @command{opam-installer}. In this case, the @code{opam} package must
4716 be added to the @code{native-inputs} field of the package definition.
4718 Note that most OCaml packages assume they will be installed in the same
4719 directory as OCaml, which is not what we want in guix. In particular, they
4720 will install @file{.so} files in their module's directory, which is usually
4721 fine because it is in the OCaml compiler directory. In guix though, these
4722 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
4723 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
4724 @file{.so} libraries should be installed.
4727 @defvr {Scheme Variable} python-build-system
4728 This variable is exported by @code{(guix build-system python)}. It
4729 implements the more or less standard build procedure used by Python
4730 packages, which consists in running @code{python setup.py build} and
4731 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
4733 For packages that install stand-alone Python programs under @code{bin/},
4734 it takes care of wrapping these programs so that their @code{PYTHONPATH}
4735 environment variable points to all the Python libraries they depend on.
4737 Which Python package is used to perform the build can be specified with
4738 the @code{#:python} parameter. This is a useful way to force a package
4739 to be built for a specific version of the Python interpreter, which
4740 might be necessary if the package is only compatible with a single
4741 interpreter version.
4743 By default guix calls @code{setup.py} under control of
4744 @code{setuptools}, much like @command{pip} does. Some packages are not
4745 compatible with setuptools (and pip), thus you can disable this by
4746 setting the @code{#:use-setuptools} parameter to @code{#f}.
4749 @defvr {Scheme Variable} perl-build-system
4750 This variable is exported by @code{(guix build-system perl)}. It
4751 implements the standard build procedure for Perl packages, which either
4752 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
4753 followed by @code{Build} and @code{Build install}; or in running
4754 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
4755 @code{make} and @code{make install}, depending on which of
4756 @code{Build.PL} or @code{Makefile.PL} is present in the package
4757 distribution. Preference is given to the former if both @code{Build.PL}
4758 and @code{Makefile.PL} exist in the package distribution. This
4759 preference can be reversed by specifying @code{#t} for the
4760 @code{#:make-maker?} parameter.
4762 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
4763 passes flags specified by the @code{#:make-maker-flags} or
4764 @code{#:module-build-flags} parameter, respectively.
4766 Which Perl package is used can be specified with @code{#:perl}.
4769 @defvr {Scheme Variable} r-build-system
4770 This variable is exported by @code{(guix build-system r)}. It
4771 implements the build procedure used by @uref{http://r-project.org, R}
4772 packages, which essentially is little more than running @code{R CMD
4773 INSTALL --library=/gnu/store/@dots{}} in an environment where
4774 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
4775 are run after installation using the R function
4776 @code{tools::testInstalledPackage}.
4779 @defvr {Scheme Variable} texlive-build-system
4780 This variable is exported by @code{(guix build-system texlive)}. It is
4781 used to build TeX packages in batch mode with a specified engine. The
4782 build system sets the @code{TEXINPUTS} variable to find all TeX source
4783 files in the inputs.
4785 By default it runs @code{luatex} on all files ending on @code{ins}. A
4786 different engine and format can be specified with the
4787 @code{#:tex-format} argument. Different build targets can be specified
4788 with the @code{#:build-targets} argument, which expects a list of file
4789 names. The build system adds only @code{texlive-bin} and
4790 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
4791 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
4792 and @code{#:texlive-latex-base}, respectively.
4794 The @code{#:tex-directory} parameter tells the build system where to
4795 install the built files under the texmf tree.
4798 @defvr {Scheme Variable} ruby-build-system
4799 This variable is exported by @code{(guix build-system ruby)}. It
4800 implements the RubyGems build procedure used by Ruby packages, which
4801 involves running @code{gem build} followed by @code{gem install}.
4803 The @code{source} field of a package that uses this build system
4804 typically references a gem archive, since this is the format that Ruby
4805 developers use when releasing their software. The build system unpacks
4806 the gem archive, potentially patches the source, runs the test suite,
4807 repackages the gem, and installs it. Additionally, directories and
4808 tarballs may be referenced to allow building unreleased gems from Git or
4809 a traditional source release tarball.
4811 Which Ruby package is used can be specified with the @code{#:ruby}
4812 parameter. A list of additional flags to be passed to the @command{gem}
4813 command can be specified with the @code{#:gem-flags} parameter.
4816 @defvr {Scheme Variable} waf-build-system
4817 This variable is exported by @code{(guix build-system waf)}. It
4818 implements a build procedure around the @code{waf} script. The common
4819 phases---@code{configure}, @code{build}, and @code{install}---are
4820 implemented by passing their names as arguments to the @code{waf}
4823 The @code{waf} script is executed by the Python interpreter. Which
4824 Python package is used to run the script can be specified with the
4825 @code{#:python} parameter.
4828 @defvr {Scheme Variable} scons-build-system
4829 This variable is exported by @code{(guix build-system scons)}. It
4830 implements the build procedure used by the SCons software construction
4831 tool. This build system runs @code{scons} to build the package,
4832 @code{scons test} to run tests, and then @code{scons install} to install
4835 Additional flags to be passed to @code{scons} can be specified with the
4836 @code{#:scons-flags} parameter. The version of Python used to run SCons
4837 can be specified by selecting the appropriate SCons package with the
4838 @code{#:scons} parameter.
4841 @defvr {Scheme Variable} haskell-build-system
4842 This variable is exported by @code{(guix build-system haskell)}. It
4843 implements the Cabal build procedure used by Haskell packages, which
4844 involves running @code{runhaskell Setup.hs configure
4845 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
4846 Instead of installing the package by running @code{runhaskell Setup.hs
4847 install}, to avoid trying to register libraries in the read-only
4848 compiler store directory, the build system uses @code{runhaskell
4849 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
4850 addition, the build system generates the package documentation by
4851 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
4852 is passed. Optional Haddock parameters can be passed with the help of
4853 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
4854 not found, the build system looks for @code{Setup.lhs} instead.
4856 Which Haskell compiler is used can be specified with the @code{#:haskell}
4857 parameter which defaults to @code{ghc}.
4860 @defvr {Scheme Variable} dub-build-system
4861 This variable is exported by @code{(guix build-system dub)}. It
4862 implements the Dub build procedure used by D packages, which
4863 involves running @code{dub build} and @code{dub run}.
4864 Installation is done by copying the files manually.
4866 Which D compiler is used can be specified with the @code{#:ldc}
4867 parameter which defaults to @code{ldc}.
4870 @defvr {Scheme Variable} emacs-build-system
4871 This variable is exported by @code{(guix build-system emacs)}. It
4872 implements an installation procedure similar to the packaging system
4873 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
4875 It first creates the @code{@var{package}-autoloads.el} file, then it
4876 byte compiles all Emacs Lisp files. Differently from the Emacs
4877 packaging system, the Info documentation files are moved to the standard
4878 documentation directory and the @file{dir} file is deleted. Each
4879 package is installed in its own directory under
4880 @file{share/emacs/site-lisp/guix.d}.
4883 @defvr {Scheme Variable} font-build-system
4884 This variable is exported by @code{(guix build-system font)}. It
4885 implements an installation procedure for font packages where upstream
4886 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
4887 need to be copied into place. It copies font files to standard
4888 locations in the output directory.
4891 @defvr {Scheme Variable} meson-build-system
4892 This variable is exported by @code{(guix build-system meson)}. It
4893 implements the build procedure for packages that use
4894 @url{http://mesonbuild.com, Meson} as their build system.
4896 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
4897 of inputs, and they can be changed with the parameters @code{#:meson}
4898 and @code{#:ninja} if needed. The default Meson is
4899 @code{meson-for-build}, which is special because it doesn't clear the
4900 @code{RUNPATH} of binaries and libraries when they are installed.
4902 This build system is an extension of @var{gnu-build-system}, but with the
4903 following phases changed to some specific for Meson:
4908 The phase runs @code{meson} with the flags specified in
4909 @code{#:configure-flags}. The flag @code{--build-type} is always set to
4910 @code{plain} unless something else is specified in @code{#:build-type}.
4913 The phase runs @code{ninja} to build the package in parallel by default, but
4914 this can be changed with @code{#:parallel-build?}.
4917 The phase runs @code{ninja} with the target specified in @code{#:test-target},
4918 which is @code{"test"} by default.
4921 The phase runs @code{ninja install} and can not be changed.
4924 Apart from that, the build system also adds the following phases:
4929 This phase ensures that all binaries can find the libraries they need.
4930 It searches for required libraries in subdirectories of the package being
4931 built, and adds those to @code{RUNPATH} where needed. It also removes
4932 references to libraries left over from the build phase by
4933 @code{meson-for-build}, such as test dependencies, that aren't actually
4934 required for the program to run.
4936 @item glib-or-gtk-wrap
4937 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
4938 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
4940 @item glib-or-gtk-compile-schemas
4941 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
4942 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
4946 Lastly, for packages that do not need anything as sophisticated, a
4947 ``trivial'' build system is provided. It is trivial in the sense that
4948 it provides basically no support: it does not pull any implicit inputs,
4949 and does not have a notion of build phases.
4951 @defvr {Scheme Variable} trivial-build-system
4952 This variable is exported by @code{(guix build-system trivial)}.
4954 This build system requires a @code{#:builder} argument. This argument
4955 must be a Scheme expression that builds the package output(s)---as
4956 with @code{build-expression->derivation} (@pxref{Derivations,
4957 @code{build-expression->derivation}}).
4967 Conceptually, the @dfn{store} is the place where derivations that have
4968 been built successfully are stored---by default, @file{/gnu/store}.
4969 Sub-directories in the store are referred to as @dfn{store items} or
4970 sometimes @dfn{store paths}. The store has an associated database that
4971 contains information such as the store paths referred to by each store
4972 path, and the list of @emph{valid} store items---results of successful
4973 builds. This database resides in @file{@var{localstatedir}/guix/db},
4974 where @var{localstatedir} is the state directory specified @i{via}
4975 @option{--localstatedir} at configure time, usually @file{/var}.
4977 The store is @emph{always} accessed by the daemon on behalf of its clients
4978 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
4979 connect to the daemon over a Unix-domain socket, send requests to it,
4980 and read the result---these are remote procedure calls, or RPCs.
4983 Users must @emph{never} modify files under @file{/gnu/store} directly.
4984 This would lead to inconsistencies and break the immutability
4985 assumptions of Guix's functional model (@pxref{Introduction}).
4987 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
4988 how to check the integrity of the store and attempt recovery from
4989 accidental modifications.
4992 The @code{(guix store)} module provides procedures to connect to the
4993 daemon, and to perform RPCs. These are described below. By default,
4994 @code{open-connection}, and thus all the @command{guix} commands,
4995 connect to the local daemon or to the URI specified by the
4996 @code{GUIX_DAEMON_SOCKET} environment variable.
4998 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
4999 When set, the value of this variable should be a file name or a URI
5000 designating the daemon endpoint. When it is a file name, it denotes a
5001 Unix-domain socket to connect to. In addition to file names, the
5002 supported URI schemes are:
5007 These are for Unix-domain sockets.
5008 @code{file:///var/guix/daemon-socket/socket} is equivalent to
5009 @file{/var/guix/daemon-socket/socket}.
5012 @cindex daemon, remote access
5013 @cindex remote access to the daemon
5014 @cindex daemon, cluster setup
5015 @cindex clusters, daemon setup
5016 These URIs denote connections over TCP/IP, without encryption nor
5017 authentication of the remote host. The URI must specify the host name
5018 and optionally a port number (by default port 44146 is used):
5021 guix://master.guix.example.org:1234
5024 This setup is suitable on local networks, such as clusters, where only
5025 trusted nodes may connect to the build daemon at
5026 @code{master.guix.example.org}.
5028 The @code{--listen} option of @command{guix-daemon} can be used to
5029 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
5033 @cindex SSH access to build daemons
5034 These URIs allow you to connect to a remote daemon over
5035 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
5036 A typical URL might look like this:
5039 ssh://charlie@@guix.example.org:22
5042 As for @command{guix copy}, the usual OpenSSH client configuration files
5043 are honored (@pxref{Invoking guix copy}).
5046 Additional URI schemes may be supported in the future.
5048 @c XXX: Remove this note when the protocol incurs fewer round trips
5049 @c and when (guix derivations) no longer relies on file system access.
5051 The ability to connect to remote build daemons is considered
5052 experimental as of @value{VERSION}. Please get in touch with us to
5053 share any problems or suggestions you may have (@pxref{Contributing}).
5057 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
5058 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
5059 @var{reserve-space?} is true, instruct it to reserve a little bit of
5060 extra space on the file system so that the garbage collector can still
5061 operate should the disk become full. Return a server object.
5063 @var{file} defaults to @var{%default-socket-path}, which is the normal
5064 location given the options that were passed to @command{configure}.
5067 @deffn {Scheme Procedure} close-connection @var{server}
5068 Close the connection to @var{server}.
5071 @defvr {Scheme Variable} current-build-output-port
5072 This variable is bound to a SRFI-39 parameter, which refers to the port
5073 where build and error logs sent by the daemon should be written.
5076 Procedures that make RPCs all take a server object as their first
5079 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
5080 @cindex invalid store items
5081 Return @code{#t} when @var{path} designates a valid store item and
5082 @code{#f} otherwise (an invalid item may exist on disk but still be
5083 invalid, for instance because it is the result of an aborted or failed
5086 A @code{&store-protocol-error} condition is raised if @var{path} is not
5087 prefixed by the store directory (@file{/gnu/store}).
5090 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
5091 Add @var{text} under file @var{name} in the store, and return its store
5092 path. @var{references} is the list of store paths referred to by the
5093 resulting store path.
5096 @deffn {Scheme Procedure} build-derivations @var{server} @var{derivations}
5097 Build @var{derivations} (a list of @code{<derivation>} objects or
5098 derivation paths), and return when the worker is done building them.
5099 Return @code{#t} on success.
5102 Note that the @code{(guix monads)} module provides a monad as well as
5103 monadic versions of the above procedures, with the goal of making it
5104 more convenient to work with code that accesses the store (@pxref{The
5108 @i{This section is currently incomplete.}
5111 @section Derivations
5114 Low-level build actions and the environment in which they are performed
5115 are represented by @dfn{derivations}. A derivation contains the
5116 following pieces of information:
5120 The outputs of the derivation---derivations produce at least one file or
5121 directory in the store, but may produce more.
5124 The inputs of the derivations, which may be other derivations or plain
5125 files in the store (patches, build scripts, etc.)
5128 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
5131 The file name of a build script in the store, along with the arguments
5135 A list of environment variables to be defined.
5139 @cindex derivation path
5140 Derivations allow clients of the daemon to communicate build actions to
5141 the store. They exist in two forms: as an in-memory representation,
5142 both on the client- and daemon-side, and as files in the store whose
5143 name end in @code{.drv}---these files are referred to as @dfn{derivation
5144 paths}. Derivations paths can be passed to the @code{build-derivations}
5145 procedure to perform the build actions they prescribe (@pxref{The
5148 @cindex fixed-output derivations
5149 Operations such as file downloads and version-control checkouts for
5150 which the expected content hash is known in advance are modeled as
5151 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
5152 of a fixed-output derivation are independent of its inputs---e.g., a
5153 source code download produces the same result regardless of the download
5154 method and tools being used.
5156 The @code{(guix derivations)} module provides a representation of
5157 derivations as Scheme objects, along with procedures to create and
5158 otherwise manipulate derivations. The lowest-level primitive to create
5159 a derivation is the @code{derivation} procedure:
5161 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
5162 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
5163 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
5164 [#:system (%current-system)] [#:references-graphs #f] @
5165 [#:allowed-references #f] [#:disallowed-references #f] @
5166 [#:leaked-env-vars #f] [#:local-build? #f] @
5167 [#:substitutable? #t] [#:properties '()]
5168 Build a derivation with the given arguments, and return the resulting
5169 @code{<derivation>} object.
5171 When @var{hash} and @var{hash-algo} are given, a
5172 @dfn{fixed-output derivation} is created---i.e., one whose result is
5173 known in advance, such as a file download. If, in addition,
5174 @var{recursive?} is true, then that fixed output may be an executable
5175 file or a directory and @var{hash} must be the hash of an archive
5176 containing this output.
5178 When @var{references-graphs} is true, it must be a list of file
5179 name/store path pairs. In that case, the reference graph of each store
5180 path is exported in the build environment in the corresponding file, in
5181 a simple text format.
5183 When @var{allowed-references} is true, it must be a list of store items
5184 or outputs that the derivation's output may refer to. Likewise,
5185 @var{disallowed-references}, if true, must be a list of things the
5186 outputs may @emph{not} refer to.
5188 When @var{leaked-env-vars} is true, it must be a list of strings
5189 denoting environment variables that are allowed to ``leak'' from the
5190 daemon's environment to the build environment. This is only applicable
5191 to fixed-output derivations---i.e., when @var{hash} is true. The main
5192 use is to allow variables such as @code{http_proxy} to be passed to
5193 derivations that download files.
5195 When @var{local-build?} is true, declare that the derivation is not a
5196 good candidate for offloading and should rather be built locally
5197 (@pxref{Daemon Offload Setup}). This is the case for small derivations
5198 where the costs of data transfers would outweigh the benefits.
5200 When @var{substitutable?} is false, declare that substitutes of the
5201 derivation's output should not be used (@pxref{Substitutes}). This is
5202 useful, for instance, when building packages that capture details of the
5203 host CPU instruction set.
5205 @var{properties} must be an association list describing ``properties'' of the
5206 derivation. It is kept as-is, uninterpreted, in the derivation.
5210 Here's an example with a shell script as its builder, assuming
5211 @var{store} is an open connection to the daemon, and @var{bash} points
5212 to a Bash executable in the store:
5215 (use-modules (guix utils)
5219 (let ((builder ; add the Bash script to the store
5220 (add-text-to-store store "my-builder.sh"
5221 "echo hello world > $out\n" '())))
5222 (derivation store "foo"
5223 bash `("-e" ,builder)
5224 #:inputs `((,bash) (,builder))
5225 #:env-vars '(("HOME" . "/homeless"))))
5226 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
5229 As can be guessed, this primitive is cumbersome to use directly. A
5230 better approach is to write build scripts in Scheme, of course! The
5231 best course of action for that is to write the build code as a
5232 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
5233 information, @pxref{G-Expressions}.
5235 Once upon a time, @code{gexp->derivation} did not exist and constructing
5236 derivations with build code written in Scheme was achieved with
5237 @code{build-expression->derivation}, documented below. This procedure
5238 is now deprecated in favor of the much nicer @code{gexp->derivation}.
5240 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
5241 @var{name} @var{exp} @
5242 [#:system (%current-system)] [#:inputs '()] @
5243 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
5244 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
5245 [#:references-graphs #f] [#:allowed-references #f] @
5246 [#:disallowed-references #f] @
5247 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
5248 Return a derivation that executes Scheme expression @var{exp} as a
5249 builder for derivation @var{name}. @var{inputs} must be a list of
5250 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
5251 @code{"out"} is assumed. @var{modules} is a list of names of Guile
5252 modules from the current search path to be copied in the store,
5253 compiled, and made available in the load path during the execution of
5254 @var{exp}---e.g., @code{((guix build utils) (guix build
5255 gnu-build-system))}.
5257 @var{exp} is evaluated in an environment where @code{%outputs} is bound
5258 to a list of output/path pairs, and where @code{%build-inputs} is bound
5259 to a list of string/output-path pairs made from @var{inputs}.
5260 Optionally, @var{env-vars} is a list of string pairs specifying the name
5261 and value of environment variables visible to the builder. The builder
5262 terminates by passing the result of @var{exp} to @code{exit}; thus, when
5263 @var{exp} returns @code{#f}, the build is considered to have failed.
5265 @var{exp} is built using @var{guile-for-build} (a derivation). When
5266 @var{guile-for-build} is omitted or is @code{#f}, the value of the
5267 @code{%guile-for-build} fluid is used instead.
5269 See the @code{derivation} procedure for the meaning of
5270 @var{references-graphs}, @var{allowed-references},
5271 @var{disallowed-references}, @var{local-build?}, and
5272 @var{substitutable?}.
5276 Here's an example of a single-output derivation that creates a directory
5277 containing one file:
5280 (let ((builder '(let ((out (assoc-ref %outputs "out")))
5281 (mkdir out) ; create /gnu/store/@dots{}-goo
5282 (call-with-output-file (string-append out "/test")
5284 (display '(hello guix) p))))))
5285 (build-expression->derivation store "goo" builder))
5287 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
5291 @node The Store Monad
5292 @section The Store Monad
5296 The procedures that operate on the store described in the previous
5297 sections all take an open connection to the build daemon as their first
5298 argument. Although the underlying model is functional, they either have
5299 side effects or depend on the current state of the store.
5301 The former is inconvenient: the connection to the build daemon has to be
5302 carried around in all those functions, making it impossible to compose
5303 functions that do not take that parameter with functions that do. The
5304 latter can be problematic: since store operations have side effects
5305 and/or depend on external state, they have to be properly sequenced.
5307 @cindex monadic values
5308 @cindex monadic functions
5309 This is where the @code{(guix monads)} module comes in. This module
5310 provides a framework for working with @dfn{monads}, and a particularly
5311 useful monad for our uses, the @dfn{store monad}. Monads are a
5312 construct that allows two things: associating ``context'' with values
5313 (in our case, the context is the store), and building sequences of
5314 computations (here computations include accesses to the store). Values
5315 in a monad---values that carry this additional context---are called
5316 @dfn{monadic values}; procedures that return such values are called
5317 @dfn{monadic procedures}.
5319 Consider this ``normal'' procedure:
5322 (define (sh-symlink store)
5323 ;; Return a derivation that symlinks the 'bash' executable.
5324 (let* ((drv (package-derivation store bash))
5325 (out (derivation->output-path drv))
5326 (sh (string-append out "/bin/bash")))
5327 (build-expression->derivation store "sh"
5328 `(symlink ,sh %output))))
5331 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
5332 as a monadic function:
5335 (define (sh-symlink)
5336 ;; Same, but return a monadic value.
5337 (mlet %store-monad ((drv (package->derivation bash)))
5338 (gexp->derivation "sh"
5339 #~(symlink (string-append #$drv "/bin/bash")
5343 There are several things to note in the second version: the @code{store}
5344 parameter is now implicit and is ``threaded'' in the calls to the
5345 @code{package->derivation} and @code{gexp->derivation} monadic
5346 procedures, and the monadic value returned by @code{package->derivation}
5347 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
5349 As it turns out, the call to @code{package->derivation} can even be
5350 omitted since it will take place implicitly, as we will see later
5351 (@pxref{G-Expressions}):
5354 (define (sh-symlink)
5355 (gexp->derivation "sh"
5356 #~(symlink (string-append #$bash "/bin/bash")
5361 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
5362 @c for the funny quote.
5363 Calling the monadic @code{sh-symlink} has no effect. As someone once
5364 said, ``you exit a monad like you exit a building on fire: by running''.
5365 So, to exit the monad and get the desired effect, one must use
5366 @code{run-with-store}:
5369 (run-with-store (open-connection) (sh-symlink))
5370 @result{} /gnu/store/...-sh-symlink
5373 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
5374 new ``meta-commands'' to make it easier to deal with monadic procedures:
5375 @code{run-in-store}, and @code{enter-store-monad}. The former is used
5376 to ``run'' a single monadic value through the store:
5379 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
5380 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
5383 The latter enters a recursive REPL, where all the return values are
5384 automatically run through the store:
5387 scheme@@(guile-user)> ,enter-store-monad
5388 store-monad@@(guile-user) [1]> (package->derivation hello)
5389 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
5390 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
5391 $3 = "/gnu/store/@dots{}-foo"
5392 store-monad@@(guile-user) [1]> ,q
5393 scheme@@(guile-user)>
5397 Note that non-monadic values cannot be returned in the
5398 @code{store-monad} REPL.
5400 The main syntactic forms to deal with monads in general are provided by
5401 the @code{(guix monads)} module and are described below.
5403 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
5404 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
5408 @deffn {Scheme Syntax} return @var{val}
5409 Return a monadic value that encapsulates @var{val}.
5412 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
5413 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
5414 procedures @var{mproc}@dots{}@footnote{This operation is commonly
5415 referred to as ``bind'', but that name denotes an unrelated procedure in
5416 Guile. Thus we use this somewhat cryptic symbol inherited from the
5417 Haskell language.}. There can be one @var{mproc} or several of them, as
5422 (with-monad %state-monad
5424 (lambda (x) (return (+ 1 x)))
5425 (lambda (x) (return (* 2 x)))))
5429 @result{} some-state
5433 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
5435 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
5437 Bind the variables @var{var} to the monadic values @var{mval} in
5438 @var{body}, which is a sequence of expressions. As with the bind
5439 operator, this can be thought of as ``unpacking'' the raw, non-monadic
5440 value ``contained'' in @var{mval} and making @var{var} refer to that
5441 raw, non-monadic value within the scope of the @var{body}. The form
5442 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
5443 @var{val}, as per @code{let}. The binding operations occur in sequence
5444 from left to right. The last expression of @var{body} must be a monadic
5445 expression, and its result will become the result of the @code{mlet} or
5446 @code{mlet*} when run in the @var{monad}.
5448 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
5449 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
5452 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
5453 Bind @var{mexp} and the following monadic expressions in sequence,
5454 returning the result of the last expression. Every expression in the
5455 sequence must be a monadic expression.
5457 This is akin to @code{mlet}, except that the return values of the
5458 monadic expressions are ignored. In that sense, it is analogous to
5459 @code{begin}, but applied to monadic expressions.
5462 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
5463 When @var{condition} is true, evaluate the sequence of monadic
5464 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
5465 @var{condition} is false, return @code{*unspecified*} in the current
5466 monad. Every expression in the sequence must be a monadic expression.
5469 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
5470 When @var{condition} is false, evaluate the sequence of monadic
5471 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
5472 @var{condition} is true, return @code{*unspecified*} in the current
5473 monad. Every expression in the sequence must be a monadic expression.
5477 The @code{(guix monads)} module provides the @dfn{state monad}, which
5478 allows an additional value---the state---to be @emph{threaded} through
5479 monadic procedure calls.
5481 @defvr {Scheme Variable} %state-monad
5482 The state monad. Procedures in the state monad can access and change
5483 the state that is threaded.
5485 Consider the example below. The @code{square} procedure returns a value
5486 in the state monad. It returns the square of its argument, but also
5487 increments the current state value:
5491 (mlet %state-monad ((count (current-state)))
5492 (mbegin %state-monad
5493 (set-current-state (+ 1 count))
5496 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
5501 When ``run'' through @var{%state-monad}, we obtain that additional state
5502 value, which is the number of @code{square} calls.
5505 @deffn {Monadic Procedure} current-state
5506 Return the current state as a monadic value.
5509 @deffn {Monadic Procedure} set-current-state @var{value}
5510 Set the current state to @var{value} and return the previous state as a
5514 @deffn {Monadic Procedure} state-push @var{value}
5515 Push @var{value} to the current state, which is assumed to be a list,
5516 and return the previous state as a monadic value.
5519 @deffn {Monadic Procedure} state-pop
5520 Pop a value from the current state and return it as a monadic value.
5521 The state is assumed to be a list.
5524 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
5525 Run monadic value @var{mval} starting with @var{state} as the initial
5526 state. Return two values: the resulting value, and the resulting state.
5529 The main interface to the store monad, provided by the @code{(guix
5530 store)} module, is as follows.
5532 @defvr {Scheme Variable} %store-monad
5533 The store monad---an alias for @var{%state-monad}.
5535 Values in the store monad encapsulate accesses to the store. When its
5536 effect is needed, a value of the store monad must be ``evaluated'' by
5537 passing it to the @code{run-with-store} procedure (see below.)
5540 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
5541 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
5542 open store connection.
5545 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
5546 Return as a monadic value the absolute file name in the store of the file
5547 containing @var{text}, a string. @var{references} is a list of store items that the
5548 resulting text file refers to; it defaults to the empty list.
5551 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
5552 Return as a monadic value the absolute file name in the store of the file
5553 containing @var{data}, a bytevector. @var{references} is a list of store
5554 items that the resulting binary file refers to; it defaults to the empty list.
5557 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
5558 [#:recursive? #t] [#:select? (const #t)]
5559 Return the name of @var{file} once interned in the store. Use
5560 @var{name} as its store name, or the basename of @var{file} if
5561 @var{name} is omitted.
5563 When @var{recursive?} is true, the contents of @var{file} are added
5564 recursively; if @var{file} designates a flat file and @var{recursive?}
5565 is true, its contents are added, and its permission bits are kept.
5567 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
5568 @var{stat})} for each directory entry, where @var{file} is the entry's
5569 absolute file name and @var{stat} is the result of @code{lstat}; exclude
5570 entries for which @var{select?} does not return true.
5572 The example below adds a file to the store, under two different names:
5575 (run-with-store (open-connection)
5576 (mlet %store-monad ((a (interned-file "README"))
5577 (b (interned-file "README" "LEGU-MIN")))
5578 (return (list a b))))
5580 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
5585 The @code{(guix packages)} module exports the following package-related
5588 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
5589 [#:system (%current-system)] [#:target #f] @
5592 value in the absolute file name of @var{file} within the @var{output}
5593 directory of @var{package}. When @var{file} is omitted, return the name
5594 of the @var{output} directory of @var{package}. When @var{target} is
5595 true, use it as a cross-compilation target triplet.
5598 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
5599 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
5600 @var{target} [@var{system}]
5601 Monadic version of @code{package-derivation} and
5602 @code{package-cross-derivation} (@pxref{Defining Packages}).
5607 @section G-Expressions
5609 @cindex G-expression
5610 @cindex build code quoting
5611 So we have ``derivations'', which represent a sequence of build actions
5612 to be performed to produce an item in the store (@pxref{Derivations}).
5613 These build actions are performed when asking the daemon to actually
5614 build the derivations; they are run by the daemon in a container
5615 (@pxref{Invoking guix-daemon}).
5617 @cindex strata of code
5618 It should come as no surprise that we like to write these build actions
5619 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
5620 code@footnote{The term @dfn{stratum} in this context was coined by
5621 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
5622 Kiselyov, who has written insightful
5623 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
5624 on this topic}, refers to this kind of code generation as
5625 @dfn{staging}.}: the ``host code''---code that defines packages, talks
5626 to the daemon, etc.---and the ``build code''---code that actually
5627 performs build actions, such as making directories, invoking
5628 @command{make}, etc.
5630 To describe a derivation and its build actions, one typically needs to
5631 embed build code inside host code. It boils down to manipulating build
5632 code as data, and the homoiconicity of Scheme---code has a direct
5633 representation as data---comes in handy for that. But we need more than
5634 the normal @code{quasiquote} mechanism in Scheme to construct build
5637 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
5638 S-expressions adapted to build expressions. G-expressions, or
5639 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
5640 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
5641 @code{#$}, and @code{#$@@}), which are comparable to
5642 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
5643 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
5644 GNU Guile Reference Manual}). However, there are major differences:
5648 Gexps are meant to be written to a file and run or manipulated by other
5652 When a high-level object such as a package or derivation is unquoted
5653 inside a gexp, the result is as if its output file name had been
5657 Gexps carry information about the packages or derivations they refer to,
5658 and these dependencies are automatically added as inputs to the build
5659 processes that use them.
5662 @cindex lowering, of high-level objects in gexps
5663 This mechanism is not limited to package and derivation
5664 objects: @dfn{compilers} able to ``lower'' other high-level objects to
5665 derivations or files in the store can be defined,
5666 such that these objects can also be inserted
5667 into gexps. For example, a useful type of high-level objects that can be
5668 inserted in a gexp is ``file-like objects'', which make it easy to
5669 add files to the store and to refer to them in
5670 derivations and such (see @code{local-file} and @code{plain-file}
5673 To illustrate the idea, here is an example of a gexp:
5680 (symlink (string-append #$coreutils "/bin/ls")
5684 This gexp can be passed to @code{gexp->derivation}; we obtain a
5685 derivation that builds a directory containing exactly one symlink to
5686 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
5689 (gexp->derivation "the-thing" build-exp)
5692 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
5693 substituted to the reference to the @var{coreutils} package in the
5694 actual build code, and @var{coreutils} is automatically made an input to
5695 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
5696 output)}) is replaced by a string containing the directory name of the
5697 output of the derivation.
5699 @cindex cross compilation
5700 In a cross-compilation context, it is useful to distinguish between
5701 references to the @emph{native} build of a package---that can run on the
5702 host---versus references to cross builds of a package. To that end, the
5703 @code{#+} plays the same role as @code{#$}, but is a reference to a
5704 native package build:
5707 (gexp->derivation "vi"
5710 (system* (string-append #+coreutils "/bin/ln")
5712 (string-append #$emacs "/bin/emacs")
5713 (string-append #$output "/bin/vi")))
5714 #:target "mips64el-linux-gnu")
5718 In the example above, the native build of @var{coreutils} is used, so
5719 that @command{ln} can actually run on the host; but then the
5720 cross-compiled build of @var{emacs} is referenced.
5722 @cindex imported modules, for gexps
5723 @findex with-imported-modules
5724 Another gexp feature is @dfn{imported modules}: sometimes you want to be
5725 able to use certain Guile modules from the ``host environment'' in the
5726 gexp, so those modules should be imported in the ``build environment''.
5727 The @code{with-imported-modules} form allows you to express that:
5730 (let ((build (with-imported-modules '((guix build utils))
5732 (use-modules (guix build utils))
5733 (mkdir-p (string-append #$output "/bin"))))))
5734 (gexp->derivation "empty-dir"
5737 (display "success!\n")
5742 In this example, the @code{(guix build utils)} module is automatically
5743 pulled into the isolated build environment of our gexp, such that
5744 @code{(use-modules (guix build utils))} works as expected.
5746 @cindex module closure
5747 @findex source-module-closure
5748 Usually you want the @emph{closure} of the module to be imported---i.e.,
5749 the module itself and all the modules it depends on---rather than just
5750 the module; failing to do that, attempts to use the module will fail
5751 because of missing dependent modules. The @code{source-module-closure}
5752 procedure computes the closure of a module by looking at its source file
5753 headers, which comes in handy in this case:
5756 (use-modules (guix modules)) ;for 'source-module-closure'
5758 (with-imported-modules (source-module-closure
5759 '((guix build utils)
5761 (gexp->derivation "something-with-vms"
5763 (use-modules (guix build utils)
5768 @cindex extensions, for gexps
5769 @findex with-extensions
5770 In the same vein, sometimes you want to import not just pure-Scheme
5771 modules, but also ``extensions'' such as Guile bindings to C libraries
5772 or other ``full-blown'' packages. Say you need the @code{guile-json}
5773 package available on the build side, here's how you would do it:
5776 (use-modules (gnu packages guile)) ;for 'guile-json'
5778 (with-extensions (list guile-json)
5779 (gexp->derivation "something-with-json"
5781 (use-modules (json))
5785 The syntactic form to construct gexps is summarized below.
5787 @deffn {Scheme Syntax} #~@var{exp}
5788 @deffnx {Scheme Syntax} (gexp @var{exp})
5789 Return a G-expression containing @var{exp}. @var{exp} may contain one
5790 or more of the following forms:
5794 @itemx (ungexp @var{obj})
5795 Introduce a reference to @var{obj}. @var{obj} may have one of the
5796 supported types, for example a package or a
5797 derivation, in which case the @code{ungexp} form is replaced by its
5798 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
5800 If @var{obj} is a list, it is traversed and references to supported
5801 objects are substituted similarly.
5803 If @var{obj} is another gexp, its contents are inserted and its
5804 dependencies are added to those of the containing gexp.
5806 If @var{obj} is another kind of object, it is inserted as is.
5808 @item #$@var{obj}:@var{output}
5809 @itemx (ungexp @var{obj} @var{output})
5810 This is like the form above, but referring explicitly to the
5811 @var{output} of @var{obj}---this is useful when @var{obj} produces
5812 multiple outputs (@pxref{Packages with Multiple Outputs}).
5815 @itemx #+@var{obj}:output
5816 @itemx (ungexp-native @var{obj})
5817 @itemx (ungexp-native @var{obj} @var{output})
5818 Same as @code{ungexp}, but produces a reference to the @emph{native}
5819 build of @var{obj} when used in a cross compilation context.
5821 @item #$output[:@var{output}]
5822 @itemx (ungexp output [@var{output}])
5823 Insert a reference to derivation output @var{output}, or to the main
5824 output when @var{output} is omitted.
5826 This only makes sense for gexps passed to @code{gexp->derivation}.
5829 @itemx (ungexp-splicing @var{lst})
5830 Like the above, but splices the contents of @var{lst} inside the
5834 @itemx (ungexp-native-splicing @var{lst})
5835 Like the above, but refers to native builds of the objects listed in
5840 G-expressions created by @code{gexp} or @code{#~} are run-time objects
5841 of the @code{gexp?} type (see below.)
5844 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
5845 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
5846 in their execution environment.
5848 Each item in @var{modules} can be the name of a module, such as
5849 @code{(guix build utils)}, or it can be a module name, followed by an
5850 arrow, followed by a file-like object:
5853 `((guix build utils)
5855 ((guix config) => ,(scheme-file "config.scm"
5856 #~(define-module @dots{}))))
5860 In the example above, the first two modules are taken from the search
5861 path, and the last one is created from the given file-like object.
5863 This form has @emph{lexical} scope: it has an effect on the gexps
5864 directly defined in @var{body}@dots{}, but not on those defined, say, in
5865 procedures called from @var{body}@dots{}.
5868 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
5869 Mark the gexps defined in @var{body}@dots{} as requiring
5870 @var{extensions} in their build and execution environment.
5871 @var{extensions} is typically a list of package objects such as those
5872 defined in the @code{(gnu packages guile)} module.
5874 Concretely, the packages listed in @var{extensions} are added to the
5875 load path while compiling imported modules in @var{body}@dots{}; they
5876 are also added to the load path of the gexp returned by
5880 @deffn {Scheme Procedure} gexp? @var{obj}
5881 Return @code{#t} if @var{obj} is a G-expression.
5884 G-expressions are meant to be written to disk, either as code building
5885 some derivation, or as plain files in the store. The monadic procedures
5886 below allow you to do that (@pxref{The Store Monad}, for more
5887 information about monads.)
5889 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
5890 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
5891 [#:hash #f] [#:hash-algo #f] @
5892 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
5893 [#:module-path @var{%load-path}] @
5894 [#:effective-version "2.2"] @
5895 [#:references-graphs #f] [#:allowed-references #f] @
5896 [#:disallowed-references #f] @
5897 [#:leaked-env-vars #f] @
5898 [#:script-name (string-append @var{name} "-builder")] @
5899 [#:deprecation-warnings #f] @
5900 [#:local-build? #f] [#:substitutable? #t] @
5901 [#:properties '()] [#:guile-for-build #f]
5902 Return a derivation @var{name} that runs @var{exp} (a gexp) with
5903 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
5904 stored in a file called @var{script-name}. When @var{target} is true,
5905 it is used as the cross-compilation target triplet for packages referred
5908 @var{modules} is deprecated in favor of @code{with-imported-modules}.
5910 make @var{modules} available in the evaluation context of @var{exp};
5911 @var{modules} is a list of names of Guile modules searched in
5912 @var{module-path} to be copied in the store, compiled, and made available in
5913 the load path during the execution of @var{exp}---e.g., @code{((guix
5914 build utils) (guix build gnu-build-system))}.
5916 @var{effective-version} determines the string to use when adding extensions of
5917 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
5919 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
5922 When @var{references-graphs} is true, it must be a list of tuples of one of the
5926 (@var{file-name} @var{package})
5927 (@var{file-name} @var{package} @var{output})
5928 (@var{file-name} @var{derivation})
5929 (@var{file-name} @var{derivation} @var{output})
5930 (@var{file-name} @var{store-item})
5933 The right-hand-side of each element of @var{references-graphs} is automatically made
5934 an input of the build process of @var{exp}. In the build environment, each
5935 @var{file-name} contains the reference graph of the corresponding item, in a simple
5938 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
5939 In the latter case, the list denotes store items that the result is allowed to
5940 refer to. Any reference to another store item will lead to a build error.
5941 Similarly for @var{disallowed-references}, which can list items that must not be
5942 referenced by the outputs.
5944 @var{deprecation-warnings} determines whether to show deprecation warnings while
5945 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
5947 The other arguments are as for @code{derivation} (@pxref{Derivations}).
5950 @cindex file-like objects
5951 The @code{local-file}, @code{plain-file}, @code{computed-file},
5952 @code{program-file}, and @code{scheme-file} procedures below return
5953 @dfn{file-like objects}. That is, when unquoted in a G-expression,
5954 these objects lead to a file in the store. Consider this G-expression:
5957 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
5958 #$(local-file "/tmp/my-nscd.conf"))
5961 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
5962 to the store. Once expanded, for instance @i{via}
5963 @code{gexp->derivation}, the G-expression refers to that copy under
5964 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
5965 does not have any effect on what the G-expression does.
5966 @code{plain-file} can be used similarly; it differs in that the file
5967 content is directly passed as a string.
5969 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
5970 [#:recursive? #f] [#:select? (const #t)]
5971 Return an object representing local file @var{file} to add to the store; this
5972 object can be used in a gexp. If @var{file} is a relative file name, it is looked
5973 up relative to the source file where this form appears. @var{file} will be added to
5974 the store under @var{name}--by default the base name of @var{file}.
5976 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
5977 designates a flat file and @var{recursive?} is true, its contents are added, and its
5978 permission bits are kept.
5980 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
5981 @var{stat})} for each directory entry, where @var{file} is the entry's
5982 absolute file name and @var{stat} is the result of @code{lstat}; exclude
5983 entries for which @var{select?} does not return true.
5985 This is the declarative counterpart of the @code{interned-file} monadic
5986 procedure (@pxref{The Store Monad, @code{interned-file}}).
5989 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
5990 Return an object representing a text file called @var{name} with the given
5991 @var{content} (a string or a bytevector) to be added to the store.
5993 This is the declarative counterpart of @code{text-file}.
5996 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
5997 [#:options '(#:local-build? #t)]
5998 Return an object representing the store item @var{name}, a file or
5999 directory computed by @var{gexp}. @var{options}
6000 is a list of additional arguments to pass to @code{gexp->derivation}.
6002 This is the declarative counterpart of @code{gexp->derivation}.
6005 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
6006 [#:guile (default-guile)] [#:module-path %load-path]
6007 Return an executable script @var{name} that runs @var{exp} using
6008 @var{guile}, with @var{exp}'s imported modules in its search path.
6009 Look up @var{exp}'s modules in @var{module-path}.
6011 The example below builds a script that simply invokes the @command{ls}
6015 (use-modules (guix gexp) (gnu packages base))
6017 (gexp->script "list-files"
6018 #~(execl #$(file-append coreutils "/bin/ls")
6022 When ``running'' it through the store (@pxref{The Store Monad,
6023 @code{run-with-store}}), we obtain a derivation that produces an
6024 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
6027 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
6029 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
6033 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
6034 [#:guile #f] [#:module-path %load-path]
6035 Return an object representing the executable store item @var{name} that
6036 runs @var{gexp}. @var{guile} is the Guile package used to execute that
6037 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
6039 This is the declarative counterpart of @code{gexp->script}.
6042 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
6043 [#:set-load-path? #t] [#:module-path %load-path] @
6045 [#:guile (default-guile)]
6046 Return a derivation that builds a file @var{name} containing @var{exp}.
6047 When @var{splice?} is true, @var{exp} is considered to be a list of
6048 expressions that will be spliced in the resulting file.
6050 When @var{set-load-path?} is true, emit code in the resulting file to
6051 set @code{%load-path} and @code{%load-compiled-path} to honor
6052 @var{exp}'s imported modules. Look up @var{exp}'s modules in
6055 The resulting file holds references to all the dependencies of @var{exp}
6056 or a subset thereof.
6059 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
6060 Return an object representing the Scheme file @var{name} that contains
6063 This is the declarative counterpart of @code{gexp->file}.
6066 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
6067 Return as a monadic value a derivation that builds a text file
6068 containing all of @var{text}. @var{text} may list, in addition to
6069 strings, objects of any type that can be used in a gexp: packages,
6070 derivations, local file objects, etc. The resulting store file holds
6071 references to all these.
6073 This variant should be preferred over @code{text-file} anytime the file
6074 to create will reference items from the store. This is typically the
6075 case when building a configuration file that embeds store file names,
6079 (define (profile.sh)
6080 ;; Return the name of a shell script in the store that
6081 ;; initializes the 'PATH' environment variable.
6082 (text-file* "profile.sh"
6083 "export PATH=" coreutils "/bin:"
6084 grep "/bin:" sed "/bin\n"))
6087 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
6088 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
6089 preventing them from being garbage-collected during its lifetime.
6092 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
6093 Return an object representing store file @var{name} containing
6094 @var{text}. @var{text} is a sequence of strings and file-like objects,
6098 (mixed-text-file "profile"
6099 "export PATH=" coreutils "/bin:" grep "/bin")
6102 This is the declarative counterpart of @code{text-file*}.
6105 @deffn {Scheme Procedure} file-union @var{name} @var{files}
6106 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
6107 Each item in @var{files} must be a two-element list where the first element is the
6108 file name to use in the new directory, and the second element is a gexp
6109 denoting the target file. Here's an example:
6113 `(("hosts" ,(plain-file "hosts"
6114 "127.0.0.1 localhost"))
6115 ("bashrc" ,(plain-file "bashrc"
6116 "alias ls='ls --color=auto'"))))
6119 This yields an @code{etc} directory containing these two files.
6122 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
6123 Return a directory that is the union of @var{things}, where @var{things} is a list of
6124 file-like objects denoting directories. For example:
6127 (directory-union "guile+emacs" (list guile emacs))
6130 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
6133 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
6134 Return a file-like object that expands to the concatenation of @var{obj}
6135 and @var{suffix}, where @var{obj} is a lowerable object and each
6136 @var{suffix} is a string.
6138 As an example, consider this gexp:
6141 (gexp->script "run-uname"
6142 #~(system* #$(file-append coreutils
6146 The same effect could be achieved with:
6149 (gexp->script "run-uname"
6150 #~(system* (string-append #$coreutils
6154 There is one difference though: in the @code{file-append} case, the
6155 resulting script contains the absolute file name as a string, whereas in
6156 the second case, the resulting script contains a @code{(string-append
6157 @dots{})} expression to construct the file name @emph{at run time}.
6161 Of course, in addition to gexps embedded in ``host'' code, there are
6162 also modules containing build tools. To make it clear that they are
6163 meant to be used in the build stratum, these modules are kept in the
6164 @code{(guix build @dots{})} name space.
6166 @cindex lowering, of high-level objects in gexps
6167 Internally, high-level objects are @dfn{lowered}, using their compiler,
6168 to either derivations or store items. For instance, lowering a package
6169 yields a derivation, and lowering a @code{plain-file} yields a store
6170 item. This is achieved using the @code{lower-object} monadic procedure.
6172 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
6174 Return as a value in @var{%store-monad} the derivation or store item
6175 corresponding to @var{obj} for @var{system}, cross-compiling for
6176 @var{target} if @var{target} is true. @var{obj} must be an object that
6177 has an associated gexp compiler, such as a @code{<package>}.
6180 @node Invoking guix repl
6181 @section Invoking @command{guix repl}
6183 @cindex REPL, read-eval-print loop
6184 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
6185 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
6186 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
6187 command, @command{guix repl} guarantees that all the Guix modules and all its
6188 dependencies are available in the search path. You can use it this way:
6192 scheme@@(guile-user)> ,use (gnu packages base)
6193 scheme@@(guile-user)> coreutils
6194 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
6198 In addition, @command{guix repl} implements a simple machine-readable REPL
6199 protocol for use by @code{(guix inferior)}, a facility to interact with
6200 @dfn{inferiors}, separate processes running a potentially different revision
6203 The available options are as follows:
6206 @item --type=@var{type}
6207 @itemx -t @var{type}
6208 Start a REPL of the given @var{TYPE}, which can be one of the following:
6212 This is default, and it spawns a standard full-featured Guile REPL.
6214 Spawn a REPL that uses the machine-readable protocol. This is the protocol
6215 that the @code{(guix inferior)} module speaks.
6218 @item --listen=@var{endpoint}
6219 By default, @command{guix repl} reads from standard input and writes to
6220 standard output. When this option is passed, it will instead listen for
6221 connections on @var{endpoint}. Here are examples of valid options:
6224 @item --listen=tcp:37146
6225 Accept connections on localhost on port 37146.
6227 @item --listen=unix:/tmp/socket
6228 Accept connections on the Unix-domain socket @file{/tmp/socket}.
6232 @c *********************************************************************
6236 This section describes Guix command-line utilities. Some of them are
6237 primarily targeted at developers and users who write new package
6238 definitions, while others are more generally useful. They complement
6239 the Scheme programming interface of Guix in a convenient way.
6242 * Invoking guix build:: Building packages from the command line.
6243 * Invoking guix edit:: Editing package definitions.
6244 * Invoking guix download:: Downloading a file and printing its hash.
6245 * Invoking guix hash:: Computing the cryptographic hash of a file.
6246 * Invoking guix import:: Importing package definitions.
6247 * Invoking guix refresh:: Updating package definitions.
6248 * Invoking guix lint:: Finding errors in package definitions.
6249 * Invoking guix size:: Profiling disk usage.
6250 * Invoking guix graph:: Visualizing the graph of packages.
6251 * Invoking guix environment:: Setting up development environments.
6252 * Invoking guix publish:: Sharing substitutes.
6253 * Invoking guix challenge:: Challenging substitute servers.
6254 * Invoking guix copy:: Copying to and from a remote store.
6255 * Invoking guix container:: Process isolation.
6256 * Invoking guix weather:: Assessing substitute availability.
6257 * Invoking guix processes:: Listing client processes.
6260 @node Invoking guix build
6261 @section Invoking @command{guix build}
6263 @cindex package building
6264 @cindex @command{guix build}
6265 The @command{guix build} command builds packages or derivations and
6266 their dependencies, and prints the resulting store paths. Note that it
6267 does not modify the user's profile---this is the job of the
6268 @command{guix package} command (@pxref{Invoking guix package}). Thus,
6269 it is mainly useful for distribution developers.
6271 The general syntax is:
6274 guix build @var{options} @var{package-or-derivation}@dots{}
6277 As an example, the following command builds the latest versions of Emacs
6278 and of Guile, displays their build logs, and finally displays the
6279 resulting directories:
6282 guix build emacs guile
6285 Similarly, the following command builds all the available packages:
6288 guix build --quiet --keep-going \
6289 `guix package -A | cut -f1,2 --output-delimiter=@@`
6292 @var{package-or-derivation} may be either the name of a package found in
6293 the software distribution such as @code{coreutils} or
6294 @code{coreutils@@8.20}, or a derivation such as
6295 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
6296 package with the corresponding name (and optionally version) is searched
6297 for among the GNU distribution modules (@pxref{Package Modules}).
6299 Alternatively, the @code{--expression} option may be used to specify a
6300 Scheme expression that evaluates to a package; this is useful when
6301 disambiguating among several same-named packages or package variants is
6304 There may be zero or more @var{options}. The available options are
6305 described in the subsections below.
6308 * Common Build Options:: Build options for most commands.
6309 * Package Transformation Options:: Creating variants of packages.
6310 * Additional Build Options:: Options specific to 'guix build'.
6311 * Debugging Build Failures:: Real life packaging experience.
6314 @node Common Build Options
6315 @subsection Common Build Options
6317 A number of options that control the build process are common to
6318 @command{guix build} and other commands that can spawn builds, such as
6319 @command{guix package} or @command{guix archive}. These are the
6324 @item --load-path=@var{directory}
6325 @itemx -L @var{directory}
6326 Add @var{directory} to the front of the package module search path
6327 (@pxref{Package Modules}).
6329 This allows users to define their own packages and make them visible to
6330 the command-line tools.
6334 Keep the build tree of failed builds. Thus, if a build fails, its build
6335 tree is kept under @file{/tmp}, in a directory whose name is shown at
6336 the end of the build log. This is useful when debugging build issues.
6337 @xref{Debugging Build Failures}, for tips and tricks on how to debug
6340 This option has no effect when connecting to a remote daemon with a
6341 @code{guix://} URI (@pxref{The Store, the @code{GUIX_DAEMON_SOCKET}
6346 Keep going when some of the derivations fail to build; return only once
6347 all the builds have either completed or failed.
6349 The default behavior is to stop as soon as one of the specified
6350 derivations has failed.
6354 Do not build the derivations.
6356 @anchor{fallback-option}
6358 When substituting a pre-built binary fails, fall back to building
6359 packages locally (@pxref{Substitution Failure}).
6361 @item --substitute-urls=@var{urls}
6362 @anchor{client-substitute-urls}
6363 Consider @var{urls} the whitespace-separated list of substitute source
6364 URLs, overriding the default list of URLs of @command{guix-daemon}
6365 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
6367 This means that substitutes may be downloaded from @var{urls}, provided
6368 they are signed by a key authorized by the system administrator
6369 (@pxref{Substitutes}).
6371 When @var{urls} is the empty string, substitutes are effectively
6374 @item --no-substitutes
6375 Do not use substitutes for build products. That is, always build things
6376 locally instead of allowing downloads of pre-built binaries
6377 (@pxref{Substitutes}).
6380 Do not ``graft'' packages. In practice, this means that package updates
6381 available as grafts are not applied. @xref{Security Updates}, for more
6382 information on grafts.
6384 @item --rounds=@var{n}
6385 Build each derivation @var{n} times in a row, and raise an error if
6386 consecutive build results are not bit-for-bit identical.
6388 This is a useful way to detect non-deterministic builds processes.
6389 Non-deterministic build processes are a problem because they make it
6390 practically impossible for users to @emph{verify} whether third-party
6391 binaries are genuine. @xref{Invoking guix challenge}, for more.
6393 Note that, currently, the differing build results are not kept around,
6394 so you will have to manually investigate in case of an error---e.g., by
6395 stashing one of the build results with @code{guix archive --export}
6396 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
6399 @item --no-build-hook
6400 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
6401 (@pxref{Daemon Offload Setup}). That is, always build things locally
6402 instead of offloading builds to remote machines.
6404 @item --max-silent-time=@var{seconds}
6405 When the build or substitution process remains silent for more than
6406 @var{seconds}, terminate it and report a build failure.
6408 By default, the daemon's setting is honored (@pxref{Invoking
6409 guix-daemon, @code{--max-silent-time}}).
6411 @item --timeout=@var{seconds}
6412 Likewise, when the build or substitution process lasts for more than
6413 @var{seconds}, terminate it and report a build failure.
6415 By default, the daemon's setting is honored (@pxref{Invoking
6416 guix-daemon, @code{--timeout}}).
6418 @c Note: This option is actually not part of %standard-build-options but
6419 @c most programs honor it.
6420 @cindex verbosity, of the command-line tools
6421 @cindex build logs, verbosity
6422 @item -v @var{level}
6423 @itemx --verbosity=@var{level}
6424 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
6425 output is produced, 1 is for quiet output, and 2 shows all the build log
6426 output on standard error.
6428 @item --cores=@var{n}
6430 Allow the use of up to @var{n} CPU cores for the build. The special
6431 value @code{0} means to use as many CPU cores as available.
6433 @item --max-jobs=@var{n}
6435 Allow at most @var{n} build jobs in parallel. @xref{Invoking
6436 guix-daemon, @code{--max-jobs}}, for details about this option and the
6437 equivalent @command{guix-daemon} option.
6439 @item --debug=@var{level}
6440 Produce debugging output coming from the build daemon. @var{level} must be an
6441 integer between 0 and 5; higher means more verbose output. Setting a level of
6442 4 or more may be helpful when debugging setup issues with the build daemon.
6446 Behind the scenes, @command{guix build} is essentially an interface to
6447 the @code{package-derivation} procedure of the @code{(guix packages)}
6448 module, and to the @code{build-derivations} procedure of the @code{(guix
6449 derivations)} module.
6451 In addition to options explicitly passed on the command line,
6452 @command{guix build} and other @command{guix} commands that support
6453 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
6455 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
6456 Users can define this variable to a list of command line options that
6457 will automatically be used by @command{guix build} and other
6458 @command{guix} commands that can perform builds, as in the example
6462 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
6465 These options are parsed independently, and the result is appended to
6466 the parsed command-line options.
6470 @node Package Transformation Options
6471 @subsection Package Transformation Options
6473 @cindex package variants
6474 Another set of command-line options supported by @command{guix build}
6475 and also @command{guix package} are @dfn{package transformation
6476 options}. These are options that make it possible to define @dfn{package
6477 variants}---for instance, packages built from different source code.
6478 This is a convenient way to create customized packages on the fly
6479 without having to type in the definitions of package variants
6480 (@pxref{Defining Packages}).
6484 @item --with-source=@var{source}
6485 @itemx --with-source=@var{package}=@var{source}
6486 @itemx --with-source=@var{package}@@@var{version}=@var{source}
6487 Use @var{source} as the source of @var{package}, and @var{version} as
6489 @var{source} must be a file name or a URL, as for @command{guix
6490 download} (@pxref{Invoking guix download}).
6492 When @var{package} is omitted,
6493 it is taken to be the package name specified on the
6494 command line that matches the base of @var{source}---e.g.,
6495 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
6496 package is @code{guile}.
6498 Likewise, when @var{version} is omitted, the version string is inferred from
6499 @var{source}; in the previous example, it is @code{2.0.10}.
6501 This option allows users to try out versions of packages other than the
6502 one provided by the distribution. The example below downloads
6503 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
6504 the @code{ed} package:
6507 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
6510 As a developer, @code{--with-source} makes it easy to test release
6514 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
6517 @dots{} or to build from a checkout in a pristine environment:
6520 $ git clone git://git.sv.gnu.org/guix.git
6521 $ guix build guix --with-source=guix@@1.0=./guix
6524 @item --with-input=@var{package}=@var{replacement}
6525 Replace dependency on @var{package} by a dependency on
6526 @var{replacement}. @var{package} must be a package name, and
6527 @var{replacement} must be a package specification such as @code{guile}
6528 or @code{guile@@1.8}.
6530 For instance, the following command builds Guix, but replaces its
6531 dependency on the current stable version of Guile with a dependency on
6532 the legacy version of Guile, @code{guile@@2.0}:
6535 guix build --with-input=guile=guile@@2.0 guix
6538 This is a recursive, deep replacement. So in this example, both
6539 @code{guix} and its dependency @code{guile-json} (which also depends on
6540 @code{guile}) get rebuilt against @code{guile@@2.0}.
6542 This is implemented using the @code{package-input-rewriting} Scheme
6543 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
6545 @item --with-graft=@var{package}=@var{replacement}
6546 This is similar to @code{--with-input} but with an important difference:
6547 instead of rebuilding the whole dependency chain, @var{replacement} is
6548 built and then @dfn{grafted} onto the binaries that were initially
6549 referring to @var{package}. @xref{Security Updates}, for more
6550 information on grafts.
6552 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
6553 and all its dependencies, replacing references to the version of GnuTLS
6554 they currently refer to:
6557 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
6560 This has the advantage of being much faster than rebuilding everything.
6561 But there is a caveat: it works if and only if @var{package} and
6562 @var{replacement} are strictly compatible---for example, if they provide
6563 a library, the application binary interface (ABI) of those libraries
6564 must be compatible. If @var{replacement} is somehow incompatible with
6565 @var{package}, then the resulting package may be unusable. Use with
6568 @item --with-branch=@var{package}=@var{branch}
6569 @cindex Git, using the latest commit
6570 @cindex latest commit, building
6571 Build @var{package} from the latest commit of @var{branch}. The @code{source}
6572 field of @var{package} must be an origin with the @code{git-fetch} method
6573 (@pxref{origin Reference}) or a @code{git-checkout} object; the repository URL
6574 is taken from that @code{source}.
6576 For instance, the following command builds @code{guile-sqlite3} from the
6577 latest commit of its @code{master} branch, and then builds @code{guix} (which
6578 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
6579 specific @code{guile-sqlite3} build:
6582 guix build --with-branch=guile-sqlite3=master cuirass
6585 @cindex continuous integration
6586 Obviously, since it uses the latest commit of the given branch, the result of
6587 such a command varies over time. Nevertheless it is a convenient way to
6588 rebuild entire software stacks against the latest commit of one or more
6589 packages. This is particularly useful in the context of continuous
6592 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
6593 consecutive accesses to the same repository. You may want to clean it up once
6594 in a while to save disk space.
6596 @item --with-commit=@var{package}=@var{commit}
6597 This is similar to @code{--with-branch}, except that it builds from
6598 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
6599 Git commit SHA1 identifier.
6602 @node Additional Build Options
6603 @subsection Additional Build Options
6605 The command-line options presented below are specific to @command{guix
6612 Build quietly, without displaying the build log; this is equivalent to
6613 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
6614 (or similar) and can always be retrieved using the @option{--log-file} option.
6616 @item --file=@var{file}
6617 @itemx -f @var{file}
6618 Build the package, derivation, or other file-like object that the code within
6619 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
6621 As an example, @var{file} might contain a package definition like this
6622 (@pxref{Defining Packages}):
6625 @verbatiminclude package-hello.scm
6628 @item --expression=@var{expr}
6629 @itemx -e @var{expr}
6630 Build the package or derivation @var{expr} evaluates to.
6632 For example, @var{expr} may be @code{(@@ (gnu packages guile)
6633 guile-1.8)}, which unambiguously designates this specific variant of
6634 version 1.8 of Guile.
6636 Alternatively, @var{expr} may be a G-expression, in which case it is used
6637 as a build program passed to @code{gexp->derivation}
6638 (@pxref{G-Expressions}).
6640 Lastly, @var{expr} may refer to a zero-argument monadic procedure
6641 (@pxref{The Store Monad}). The procedure must return a derivation as a
6642 monadic value, which is then passed through @code{run-with-store}.
6646 Build the source derivations of the packages, rather than the packages
6649 For instance, @code{guix build -S gcc} returns something like
6650 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
6653 The returned source tarball is the result of applying any patches and
6654 code snippets specified in the package @code{origin} (@pxref{Defining
6658 Fetch and return the source of @var{package-or-derivation} and all their
6659 dependencies, recursively. This is a handy way to obtain a local copy
6660 of all the source code needed to build @var{packages}, allowing you to
6661 eventually build them even without network access. It is an extension
6662 of the @code{--source} option and can accept one of the following
6663 optional argument values:
6667 This value causes the @code{--sources} option to behave in the same way
6668 as the @code{--source} option.
6671 Build the source derivations of all packages, including any source that
6672 might be listed as @code{inputs}. This is the default value.
6675 $ guix build --sources tzdata
6676 The following derivations will be built:
6677 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
6678 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
6682 Build the source derivations of all packages, as well of all transitive
6683 inputs to the packages. This can be used e.g.@: to
6684 prefetch package source for later offline building.
6687 $ guix build --sources=transitive tzdata
6688 The following derivations will be built:
6689 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
6690 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
6691 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
6692 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
6693 /gnu/store/@dots{}-make-4.1.tar.xz.drv
6694 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
6700 @item --system=@var{system}
6701 @itemx -s @var{system}
6702 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
6703 the system type of the build host.
6706 The @code{--system} flag is for @emph{native} compilation and must not
6707 be confused with cross-compilation. See @code{--target} below for
6708 information on cross-compilation.
6711 An example use of this is on Linux-based systems, which can emulate
6712 different personalities. For instance, passing
6713 @code{--system=i686-linux} on an @code{x86_64-linux} system or
6714 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
6715 to build packages in a complete 32-bit environment.
6718 Building for an @code{armhf-linux} system is unconditionally enabled on
6719 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
6720 allow for this functionality, notably the ThunderX.
6723 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
6724 is enabled (@pxref{Virtualization Services,
6725 @code{qemu-binfmt-service-type}}), you can build for any system for
6726 which a QEMU @code{binfmt_misc} handler is installed.
6728 Builds for a system other than that of the machine you are using can
6729 also be offloaded to a remote machine of the right architecture.
6730 @xref{Daemon Offload Setup}, for more information on offloading.
6732 @item --target=@var{triplet}
6733 @cindex cross-compilation
6734 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
6735 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
6736 configuration triplets,, autoconf, Autoconf}).
6738 @anchor{build-check}
6740 @cindex determinism, checking
6741 @cindex reproducibility, checking
6742 Rebuild @var{package-or-derivation}, which are already available in the
6743 store, and raise an error if the build results are not bit-for-bit
6746 This mechanism allows you to check whether previously installed
6747 substitutes are genuine (@pxref{Substitutes}), or whether the build result
6748 of a package is deterministic. @xref{Invoking guix challenge}, for more
6749 background information and tools.
6751 When used in conjunction with @option{--keep-failed}, the differing
6752 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
6753 This makes it easy to look for differences between the two results.
6756 @cindex repairing store items
6757 @cindex corruption, recovering from
6758 Attempt to repair the specified store items, if they are corrupt, by
6759 re-downloading or rebuilding them.
6761 This operation is not atomic and thus restricted to @code{root}.
6765 Return the derivation paths, not the output paths, of the given
6768 @item --root=@var{file}
6769 @itemx -r @var{file}
6770 @cindex GC roots, adding
6771 @cindex garbage collector roots, adding
6772 Make @var{file} a symlink to the result, and register it as a garbage
6775 Consequently, the results of this @command{guix build} invocation are
6776 protected from garbage collection until @var{file} is removed. When
6777 that option is omitted, build results are eligible for garbage
6778 collection as soon as the build completes. @xref{Invoking guix gc}, for
6782 @cindex build logs, access
6783 Return the build log file names or URLs for the given
6784 @var{package-or-derivation}, or raise an error if build logs are
6787 This works regardless of how packages or derivations are specified. For
6788 instance, the following invocations are equivalent:
6791 guix build --log-file `guix build -d guile`
6792 guix build --log-file `guix build guile`
6793 guix build --log-file guile
6794 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
6797 If a log is unavailable locally, and unless @code{--no-substitutes} is
6798 passed, the command looks for a corresponding log on one of the
6799 substitute servers (as specified with @code{--substitute-urls}.)
6801 So for instance, imagine you want to see the build log of GDB on MIPS,
6802 but you are actually on an @code{x86_64} machine:
6805 $ guix build --log-file gdb -s mips64el-linux
6806 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
6809 You can freely access a huge library of build logs!
6812 @node Debugging Build Failures
6813 @subsection Debugging Build Failures
6815 @cindex build failures, debugging
6816 When defining a new package (@pxref{Defining Packages}), you will
6817 probably find yourself spending some time debugging and tweaking the
6818 build until it succeeds. To do that, you need to operate the build
6819 commands yourself in an environment as close as possible to the one the
6822 To that end, the first thing to do is to use the @option{--keep-failed}
6823 or @option{-K} option of @command{guix build}, which will keep the
6824 failed build tree in @file{/tmp} or whatever directory you specified as
6825 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
6827 From there on, you can @command{cd} to the failed build tree and source
6828 the @file{environment-variables} file, which contains all the
6829 environment variable definitions that were in place when the build
6830 failed. So let's say you're debugging a build failure in package
6831 @code{foo}; a typical session would look like this:
6835 @dots{} @i{build fails}
6836 $ cd /tmp/guix-build-foo.drv-0
6837 $ source ./environment-variables
6841 Now, you can invoke commands as if you were the daemon (almost) and
6842 troubleshoot your build process.
6844 Sometimes it happens that, for example, a package's tests pass when you
6845 run them manually but they fail when the daemon runs them. This can
6846 happen because the daemon runs builds in containers where, unlike in our
6847 environment above, network access is missing, @file{/bin/sh} does not
6848 exist, etc. (@pxref{Build Environment Setup}).
6850 In such cases, you may need to run inspect the build process from within
6851 a container similar to the one the build daemon creates:
6856 $ cd /tmp/guix-build-foo.drv-0
6857 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
6858 [env]# source ./environment-variables
6862 Here, @command{guix environment -C} creates a container and spawns a new
6863 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
6864 strace gdb} part adds the @command{strace} and @command{gdb} commands to
6865 the container, which would may find handy while debugging. The
6866 @option{--no-grafts} option makes sure we get the exact same
6867 environment, with ungrafted packages (@pxref{Security Updates}, for more
6870 To get closer to a container like that used by the build daemon, we can
6871 remove @file{/bin/sh}:
6877 (Don't worry, this is harmless: this is all happening in the throw-away
6878 container created by @command{guix environment}.)
6880 The @command{strace} command is probably not in the search path, but we
6884 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
6887 In this way, not only you will have reproduced the environment variables
6888 the daemon uses, you will also be running the build process in a container
6889 similar to the one the daemon uses.
6892 @node Invoking guix edit
6893 @section Invoking @command{guix edit}
6895 @cindex @command{guix edit}
6896 @cindex package definition, editing
6897 So many packages, so many source files! The @command{guix edit} command
6898 facilitates the life of users and packagers by pointing their editor at
6899 the source file containing the definition of the specified packages.
6903 guix edit gcc@@4.9 vim
6907 launches the program specified in the @code{VISUAL} or in the
6908 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
6911 If you are using a Guix Git checkout (@pxref{Building from Git}), or
6912 have created your own packages on @code{GUIX_PACKAGE_PATH}
6913 (@pxref{Package Modules}), you will be able to edit the package
6914 recipes. In other cases, you will be able to examine the read-only recipes
6915 for packages currently in the store.
6918 @node Invoking guix download
6919 @section Invoking @command{guix download}
6921 @cindex @command{guix download}
6922 @cindex downloading package sources
6923 When writing a package definition, developers typically need to download
6924 a source tarball, compute its SHA256 hash, and write that
6925 hash in the package definition (@pxref{Defining Packages}). The
6926 @command{guix download} tool helps with this task: it downloads a file
6927 from the given URI, adds it to the store, and prints both its file name
6928 in the store and its SHA256 hash.
6930 The fact that the downloaded file is added to the store saves bandwidth:
6931 when the developer eventually tries to build the newly defined package
6932 with @command{guix build}, the source tarball will not have to be
6933 downloaded again because it is already in the store. It is also a
6934 convenient way to temporarily stash files, which may be deleted
6935 eventually (@pxref{Invoking guix gc}).
6937 The @command{guix download} command supports the same URIs as used in
6938 package definitions. In particular, it supports @code{mirror://} URIs.
6939 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
6940 Guile bindings for GnuTLS are available in the user's environment; when
6941 they are not available, an error is raised. @xref{Guile Preparations,
6942 how to install the GnuTLS bindings for Guile,, gnutls-guile,
6943 GnuTLS-Guile}, for more information.
6945 @command{guix download} verifies HTTPS server certificates by loading
6946 the certificates of X.509 authorities from the directory pointed to by
6947 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
6948 Certificates}), unless @option{--no-check-certificate} is used.
6950 The following options are available:
6953 @item --format=@var{fmt}
6955 Write the hash in the format specified by @var{fmt}. For more
6956 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
6958 @item --no-check-certificate
6959 Do not validate the X.509 certificates of HTTPS servers.
6961 When using this option, you have @emph{absolutely no guarantee} that you
6962 are communicating with the authentic server responsible for the given
6963 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
6965 @item --output=@var{file}
6966 @itemx -o @var{file}
6967 Save the downloaded file to @var{file} instead of adding it to the
6971 @node Invoking guix hash
6972 @section Invoking @command{guix hash}
6974 @cindex @command{guix hash}
6975 The @command{guix hash} command computes the SHA256 hash of a file.
6976 It is primarily a convenience tool for anyone contributing to the
6977 distribution: it computes the cryptographic hash of a file, which can be
6978 used in the definition of a package (@pxref{Defining Packages}).
6980 The general syntax is:
6983 guix hash @var{option} @var{file}
6986 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
6987 hash of data read from standard input. @command{guix hash} has the
6992 @item --format=@var{fmt}
6994 Write the hash in the format specified by @var{fmt}.
6996 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
6997 (@code{hex} and @code{hexadecimal} can be used as well).
6999 If the @option{--format} option is not specified, @command{guix hash}
7000 will output the hash in @code{nix-base32}. This representation is used
7001 in the definitions of packages.
7005 Compute the hash on @var{file} recursively.
7007 In this case, the hash is computed on an archive containing @var{file},
7008 including its children if it is a directory. Some of the metadata of
7009 @var{file} is part of the archive; for instance, when @var{file} is a
7010 regular file, the hash is different depending on whether @var{file} is
7011 executable or not. Metadata such as time stamps has no impact on the
7012 hash (@pxref{Invoking guix archive}).
7013 @c FIXME: Replace xref above with xref to an ``Archive'' section when
7018 When combined with @option{--recursive}, exclude version control system
7019 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
7022 As an example, here is how you would compute the hash of a Git checkout,
7023 which is useful when using the @code{git-fetch} method (@pxref{origin
7027 $ git clone http://example.org/foo.git
7033 @node Invoking guix import
7034 @section Invoking @command{guix import}
7036 @cindex importing packages
7037 @cindex package import
7038 @cindex package conversion
7039 @cindex Invoking @command{guix import}
7040 The @command{guix import} command is useful for people who would like to
7041 add a package to the distribution with as little work as
7042 possible---a legitimate demand. The command knows of a few
7043 repositories from which it can ``import'' package metadata. The result
7044 is a package definition, or a template thereof, in the format we know
7045 (@pxref{Defining Packages}).
7047 The general syntax is:
7050 guix import @var{importer} @var{options}@dots{}
7053 @var{importer} specifies the source from which to import package
7054 metadata, and @var{options} specifies a package identifier and other
7055 options specific to @var{importer}. Currently, the available
7060 Import metadata for the given GNU package. This provides a template
7061 for the latest version of that GNU package, including the hash of its
7062 source tarball, and its canonical synopsis and description.
7064 Additional information such as the package dependencies and its
7065 license needs to be figured out manually.
7067 For example, the following command returns a package definition for
7071 guix import gnu hello
7074 Specific command-line options are:
7077 @item --key-download=@var{policy}
7078 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
7079 keys when verifying the package signature. @xref{Invoking guix
7080 refresh, @code{--key-download}}.
7085 Import metadata from the @uref{https://pypi.python.org/, Python Package
7086 Index}. Information is taken from the JSON-formatted description
7087 available at @code{pypi.python.org} and usually includes all the relevant
7088 information, including package dependencies. For maximum efficiency, it
7089 is recommended to install the @command{unzip} utility, so that the
7090 importer can unzip Python wheels and gather data from them.
7092 The command below imports metadata for the @code{itsdangerous} Python
7096 guix import pypi itsdangerous
7102 Traverse the dependency graph of the given upstream package recursively
7103 and generate package expressions for all those packages that are not yet
7109 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
7110 is taken from the JSON-formatted description available at
7111 @code{rubygems.org} and includes most relevant information, including
7112 runtime dependencies. There are some caveats, however. The metadata
7113 doesn't distinguish between synopses and descriptions, so the same string
7114 is used for both fields. Additionally, the details of non-Ruby
7115 dependencies required to build native extensions is unavailable and left
7116 as an exercise to the packager.
7118 The command below imports metadata for the @code{rails} Ruby package:
7121 guix import gem rails
7127 Traverse the dependency graph of the given upstream package recursively
7128 and generate package expressions for all those packages that are not yet
7134 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
7135 Information is taken from the JSON-formatted metadata provided through
7136 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
7137 relevant information, such as module dependencies. License information
7138 should be checked closely. If Perl is available in the store, then the
7139 @code{corelist} utility will be used to filter core modules out of the
7140 list of dependencies.
7142 The command command below imports metadata for the @code{Acme::Boolean}
7146 guix import cpan Acme::Boolean
7151 @cindex Bioconductor
7152 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
7153 central repository for the @uref{http://r-project.org, GNU@tie{}R
7154 statistical and graphical environment}.
7156 Information is extracted from the @code{DESCRIPTION} file of the package.
7158 The command command below imports metadata for the @code{Cairo}
7162 guix import cran Cairo
7165 When @code{--recursive} is added, the importer will traverse the
7166 dependency graph of the given upstream package recursively and generate
7167 package expressions for all those packages that are not yet in Guix.
7169 When @code{--archive=bioconductor} is added, metadata is imported from
7170 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
7171 packages for for the analysis and comprehension of high-throughput
7172 genomic data in bioinformatics.
7174 Information is extracted from the @code{DESCRIPTION} file of a package
7175 published on the web interface of the Bioconductor SVN repository.
7177 The command below imports metadata for the @code{GenomicRanges}
7181 guix import cran --archive=bioconductor GenomicRanges
7187 Import metadata from @uref{http://www.ctan.org/, CTAN}, the
7188 comprehensive TeX archive network for TeX packages that are part of the
7189 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
7191 Information about the package is obtained through the XML API provided
7192 by CTAN, while the source code is downloaded from the SVN repository of
7193 the Tex Live project. This is done because the CTAN does not keep
7196 The command command below imports metadata for the @code{fontspec}
7200 guix import texlive fontspec
7203 When @code{--archive=DIRECTORY} is added, the source code is downloaded
7204 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
7205 tree in the TeX Live SVN repository, but from the specified sibling
7206 directory under the same root.
7208 The command below imports metadata for the @code{ifxetex} package from
7209 CTAN while fetching the sources from the directory
7210 @file{texmf/source/generic}:
7213 guix import texlive --archive=generic ifxetex
7217 @cindex JSON, import
7218 Import package metadata from a local JSON file. Consider the following
7219 example package definition in JSON format:
7225 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
7226 "build-system": "gnu",
7227 "home-page": "https://www.gnu.org/software/hello/",
7228 "synopsis": "Hello, GNU world: An example GNU package",
7229 "description": "GNU Hello prints a greeting.",
7230 "license": "GPL-3.0+",
7231 "native-inputs": ["gcc@@6"]
7235 The field names are the same as for the @code{<package>} record
7236 (@xref{Defining Packages}). References to other packages are provided
7237 as JSON lists of quoted package specification strings such as
7238 @code{guile} or @code{guile@@2.0}.
7240 The importer also supports a more explicit source definition using the
7241 common fields for @code{<origin>} records:
7247 "method": "url-fetch",
7248 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
7250 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
7257 The command below reads metadata from the JSON file @code{hello.json}
7258 and outputs a package expression:
7261 guix import json hello.json
7265 Import metadata from a local copy of the source of the
7266 @uref{http://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
7267 relies on the @command{nix-instantiate} command of
7268 @uref{http://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
7269 typically written in a mixture of Nix-language and Bash code. This
7270 command only imports the high-level package structure that is written in
7271 the Nix language. It normally includes all the basic fields of a
7274 When importing a GNU package, the synopsis and descriptions are replaced
7275 by their canonical upstream variant.
7277 Usually, you will first need to do:
7280 export NIX_REMOTE=daemon
7284 so that @command{nix-instantiate} does not try to open the Nix database.
7286 As an example, the command below imports the package definition of
7287 LibreOffice (more precisely, it imports the definition of the package
7288 bound to the @code{libreoffice} top-level attribute):
7291 guix import nix ~/path/to/nixpkgs libreoffice
7296 Import metadata from the Haskell community's central package archive
7297 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
7298 Cabal files and includes all the relevant information, including package
7301 Specific command-line options are:
7306 Read a Cabal file from standard input.
7307 @item --no-test-dependencies
7309 Do not include dependencies required only by the test suites.
7310 @item --cabal-environment=@var{alist}
7311 @itemx -e @var{alist}
7312 @var{alist} is a Scheme alist defining the environment in which the
7313 Cabal conditionals are evaluated. The accepted keys are: @code{os},
7314 @code{arch}, @code{impl} and a string representing the name of a flag.
7315 The value associated with a flag has to be either the symbol
7316 @code{true} or @code{false}. The value associated with other keys
7317 has to conform to the Cabal file format definition. The default value
7318 associated with the keys @code{os}, @code{arch} and @code{impl} is
7319 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
7322 Traverse the dependency graph of the given upstream package recursively
7323 and generate package expressions for all those packages that are not yet
7327 The command below imports metadata for the latest version of the
7328 @code{HTTP} Haskell package without including test dependencies and
7329 specifying the value of the flag @samp{network-uri} as @code{false}:
7332 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
7335 A specific package version may optionally be specified by following the
7336 package name by an at-sign and a version number as in the following example:
7339 guix import hackage mtl@@2.1.3.1
7344 The @code{stackage} importer is a wrapper around the @code{hackage} one.
7345 It takes a package name, looks up the package version included in a
7346 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
7347 release and uses the @code{hackage} importer to retrieve its metadata.
7348 Note that it is up to you to select an LTS release compatible with the
7349 GHC compiler used by Guix.
7351 Specific command-line options are:
7354 @item --no-test-dependencies
7356 Do not include dependencies required only by the test suites.
7357 @item --lts-version=@var{version}
7358 @itemx -l @var{version}
7359 @var{version} is the desired LTS release version. If omitted the latest
7363 Traverse the dependency graph of the given upstream package recursively
7364 and generate package expressions for all those packages that are not yet
7368 The command below imports metadata for the @code{HTTP} Haskell package
7369 included in the LTS Stackage release version 7.18:
7372 guix import stackage --lts-version=7.18 HTTP
7377 Import metadata from an Emacs Lisp Package Archive (ELPA) package
7378 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
7380 Specific command-line options are:
7383 @item --archive=@var{repo}
7384 @itemx -a @var{repo}
7385 @var{repo} identifies the archive repository from which to retrieve the
7386 information. Currently the supported repositories and their identifiers
7390 @uref{http://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
7391 identifier. This is the default.
7393 Packages from @code{elpa.gnu.org} are signed with one of the keys
7394 contained in the GnuPG keyring at
7395 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
7396 @code{emacs} package (@pxref{Package Installation, ELPA package
7397 signatures,, emacs, The GNU Emacs Manual}).
7400 @uref{http://stable.melpa.org/packages, MELPA-Stable}, selected by the
7401 @code{melpa-stable} identifier.
7404 @uref{http://melpa.org/packages, MELPA}, selected by the @code{melpa}
7410 Traverse the dependency graph of the given upstream package recursively
7411 and generate package expressions for all those packages that are not yet
7417 Import metadata from the crates.io Rust package repository
7418 @uref{https://crates.io, crates.io}.
7423 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
7424 repository used by the OCaml community.
7427 The structure of the @command{guix import} code is modular. It would be
7428 useful to have more importers for other package formats, and your help
7429 is welcome here (@pxref{Contributing}).
7431 @node Invoking guix refresh
7432 @section Invoking @command{guix refresh}
7434 @cindex @command {guix refresh}
7435 The primary audience of the @command{guix refresh} command is developers
7436 of the GNU software distribution. By default, it reports any packages
7437 provided by the distribution that are outdated compared to the latest
7438 upstream version, like this:
7442 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
7443 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
7446 Alternately, one can specify packages to consider, in which case a
7447 warning is emitted for packages that lack an updater:
7450 $ guix refresh coreutils guile guile-ssh
7451 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
7452 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
7455 @command{guix refresh} browses the upstream repository of each package and determines
7456 the highest version number of the releases therein. The command
7457 knows how to update specific types of packages: GNU packages, ELPA
7458 packages, etc.---see the documentation for @option{--type} below. There
7459 are many packages, though, for which it lacks a method to determine
7460 whether a new upstream release is available. However, the mechanism is
7461 extensible, so feel free to get in touch with us to add a new method!
7466 Consider the packages specified, and all the packages upon which they depend.
7469 $ guix refresh --recursive coreutils
7470 gnu/packages/acl.scm:35:2: warning: no updater for acl
7471 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
7472 gnu/packages/xml.scm:68:2: warning: no updater for expat
7473 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
7479 Sometimes the upstream name differs from the package name used in Guix,
7480 and @command{guix refresh} needs a little help. Most updaters honor the
7481 @code{upstream-name} property in package definitions, which can be used
7485 (define-public network-manager
7487 (name "network-manager")
7489 (properties '((upstream-name . "NetworkManager")))))
7492 When passed @code{--update}, it modifies distribution source files to
7493 update the version numbers and source tarball hashes of those package
7494 recipes (@pxref{Defining Packages}). This is achieved by downloading
7495 each package's latest source tarball and its associated OpenPGP
7496 signature, authenticating the downloaded tarball against its signature
7497 using @command{gpg}, and finally computing its hash. When the public
7498 key used to sign the tarball is missing from the user's keyring, an
7499 attempt is made to automatically retrieve it from a public key server;
7500 when this is successful, the key is added to the user's keyring; otherwise,
7501 @command{guix refresh} reports an error.
7503 The following options are supported:
7507 @item --expression=@var{expr}
7508 @itemx -e @var{expr}
7509 Consider the package @var{expr} evaluates to.
7511 This is useful to precisely refer to a package, as in this example:
7514 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
7517 This command lists the dependents of the ``final'' libc (essentially all
7522 Update distribution source files (package recipes) in place. This is
7523 usually run from a checkout of the Guix source tree (@pxref{Running
7524 Guix Before It Is Installed}):
7527 $ ./pre-inst-env guix refresh -s non-core -u
7530 @xref{Defining Packages}, for more information on package definitions.
7532 @item --select=[@var{subset}]
7533 @itemx -s @var{subset}
7534 Select all the packages in @var{subset}, one of @code{core} or
7537 The @code{core} subset refers to all the packages at the core of the
7538 distribution---i.e., packages that are used to build ``everything
7539 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
7540 changing one of these packages in the distribution entails a rebuild of
7541 all the others. Thus, such updates are an inconvenience to users in
7542 terms of build time or bandwidth used to achieve the upgrade.
7544 The @code{non-core} subset refers to the remaining packages. It is
7545 typically useful in cases where an update of the core packages would be
7548 @item --manifest=@var{file}
7549 @itemx -m @var{file}
7550 Select all the packages from the manifest in @var{file}. This is useful to
7551 check if any packages of the user manifest can be updated.
7553 @item --type=@var{updater}
7554 @itemx -t @var{updater}
7555 Select only packages handled by @var{updater} (may be a comma-separated
7556 list of updaters). Currently, @var{updater} may be one of:
7560 the updater for GNU packages;
7562 the updater for GNOME packages;
7564 the updater for KDE packages;
7566 the updater for X.org packages;
7568 the updater for packages hosted on kernel.org;
7570 the updater for @uref{http://elpa.gnu.org/, ELPA} packages;
7572 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
7574 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
7576 the updater for @uref{http://www.cpan.org/, CPAN} packages;
7578 the updater for @uref{https://pypi.python.org, PyPI} packages.
7580 the updater for @uref{https://rubygems.org, RubyGems} packages.
7582 the updater for @uref{https://github.com, GitHub} packages.
7584 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
7586 the updater for @uref{https://www.stackage.org, Stackage} packages.
7588 the updater for @uref{https://crates.io, Crates} packages.
7591 For instance, the following command only checks for updates of Emacs
7592 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
7595 $ guix refresh --type=elpa,cran
7596 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
7597 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
7602 In addition, @command{guix refresh} can be passed one or more package
7603 names, as in this example:
7606 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
7610 The command above specifically updates the @code{emacs} and
7611 @code{idutils} packages. The @code{--select} option would have no
7612 effect in this case.
7614 When considering whether to upgrade a package, it is sometimes
7615 convenient to know which packages would be affected by the upgrade and
7616 should be checked for compatibility. For this the following option may
7617 be used when passing @command{guix refresh} one or more package names:
7621 @item --list-updaters
7623 List available updaters and exit (see @option{--type} above.)
7625 For each updater, display the fraction of packages it covers; at the
7626 end, display the fraction of packages covered by all these updaters.
7628 @item --list-dependent
7630 List top-level dependent packages that would need to be rebuilt as a
7631 result of upgrading one or more packages.
7633 @xref{Invoking guix graph, the @code{reverse-package} type of
7634 @command{guix graph}}, for information on how to visualize the list of
7635 dependents of a package.
7639 Be aware that the @code{--list-dependent} option only
7640 @emph{approximates} the rebuilds that would be required as a result of
7641 an upgrade. More rebuilds might be required under some circumstances.
7644 $ guix refresh --list-dependent flex
7645 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
7646 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
7649 The command above lists a set of packages that could be built to check
7650 for compatibility with an upgraded @code{flex} package.
7654 @item --list-transitive
7655 List all the packages which one or more packages depend upon.
7658 $ guix refresh --list-transitive flex
7659 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
7660 bison@@3.0.5 indent@@2.2.10 tar@@1.30 gzip@@1.9 bzip2@@1.0.6 xz@@5.2.4 file@@5.33 @dots{}
7665 The command above lists a set of packages which, when changed, would cause
7666 @code{flex} to be rebuilt.
7668 The following options can be used to customize GnuPG operation:
7672 @item --gpg=@var{command}
7673 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
7674 for in @code{$PATH}.
7676 @item --keyring=@var{file}
7677 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
7678 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
7679 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
7680 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
7681 information on a tool to manipulate keybox files).
7683 When this option is omitted, @command{guix refresh} uses
7684 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
7685 signing keys. OpenPGP signatures are checked against keys from this keyring;
7686 missing keys are downloaded to this keyring as well (see
7687 @option{--key-download} below.)
7689 You can export keys from your default GPG keyring into a keybox file using
7690 commands like this one:
7693 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
7696 Likewise, you can fetch keys to a specific keybox file like this:
7699 gpg --no-default-keyring --keyring mykeyring.kbx \
7700 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
7703 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
7704 Privacy Guard}, for more information on GPG's @option{--keyring} option.
7706 @item --key-download=@var{policy}
7707 Handle missing OpenPGP keys according to @var{policy}, which may be one
7712 Always download missing OpenPGP keys from the key server, and add them
7713 to the user's GnuPG keyring.
7716 Never try to download missing OpenPGP keys. Instead just bail out.
7719 When a package signed with an unknown OpenPGP key is encountered, ask
7720 the user whether to download it or not. This is the default behavior.
7723 @item --key-server=@var{host}
7724 Use @var{host} as the OpenPGP key server when importing a public key.
7728 The @code{github} updater uses the
7729 @uref{https://developer.github.com/v3/, GitHub API} to query for new
7730 releases. When used repeatedly e.g.@: when refreshing all packages,
7731 GitHub will eventually refuse to answer any further API requests. By
7732 default 60 API requests per hour are allowed, and a full refresh on all
7733 GitHub packages in Guix requires more than this. Authentication with
7734 GitHub through the use of an API token alleviates these limits. To use
7735 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
7736 token procured from @uref{https://github.com/settings/tokens} or
7740 @node Invoking guix lint
7741 @section Invoking @command{guix lint}
7743 @cindex @command{guix lint}
7744 @cindex package, checking for errors
7745 The @command{guix lint} command is meant to help package developers avoid
7746 common errors and use a consistent style. It runs a number of checks on
7747 a given set of packages in order to find common mistakes in their
7748 definitions. Available @dfn{checkers} include (see
7749 @code{--list-checkers} for a complete list):
7754 Validate certain typographical and stylistic rules about package
7755 descriptions and synopses.
7757 @item inputs-should-be-native
7758 Identify inputs that should most likely be native inputs.
7764 @itemx source-file-name
7765 Probe @code{home-page} and @code{source} URLs and report those that are
7766 invalid. Suggest a @code{mirror://} URL when applicable. If the
7767 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
7768 URL. Check that the source file name is meaningful, e.g.@: is not just a
7769 version number or ``git-checkout'', without a declared @code{file-name}
7770 (@pxref{origin Reference}).
7772 @item source-unstable-tarball
7773 Parse the @code{source} URL to determine if a tarball from GitHub is
7774 autogenerated or if it is a release tarball. Unfortunately GitHub's
7775 autogenerated tarballs are sometimes regenerated.
7778 @cindex security vulnerabilities
7779 @cindex CVE, Common Vulnerabilities and Exposures
7780 Report known vulnerabilities found in the Common Vulnerabilities and
7781 Exposures (CVE) databases of the current and past year
7782 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
7785 To view information about a particular vulnerability, visit pages such as:
7789 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
7791 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
7795 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
7796 @code{CVE-2015-7554}.
7798 Package developers can specify in package recipes the
7799 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
7800 name and version of the package when they differ from the name or version
7801 that Guix uses, as in this example:
7807 ;; CPE calls this package "grub2".
7808 (properties '((cpe-name . "grub2")
7809 (cpe-version . "2.3")))
7812 @c See <http://www.openwall.com/lists/oss-security/2017/03/15/3>.
7813 Some entries in the CVE database do not specify which version of a
7814 package they apply to, and would thus ``stick around'' forever. Package
7815 developers who found CVE alerts and verified they can be ignored can
7816 declare them as in this example:
7822 ;; These CVEs no longer apply and can be safely ignored.
7823 (properties `((lint-hidden-cve . ("CVE-2011-0433"
7826 "CVE-2011-5244")))))
7830 Warn about obvious source code formatting issues: trailing white space,
7831 use of tabulations, etc.
7834 The general syntax is:
7837 guix lint @var{options} @var{package}@dots{}
7840 If no package is given on the command line, then all packages are checked.
7841 The @var{options} may be zero or more of the following:
7844 @item --list-checkers
7846 List and describe all the available checkers that will be run on packages
7851 Only enable the checkers specified in a comma-separated list using the
7852 names returned by @code{--list-checkers}.
7856 @node Invoking guix size
7857 @section Invoking @command{guix size}
7860 @cindex package size
7862 @cindex @command{guix size}
7863 The @command{guix size} command helps package developers profile the
7864 disk usage of packages. It is easy to overlook the impact of an
7865 additional dependency added to a package, or the impact of using a
7866 single output for a package that could easily be split (@pxref{Packages
7867 with Multiple Outputs}). Such are the typical issues that
7868 @command{guix size} can highlight.
7870 The command can be passed one or more package specifications
7871 such as @code{gcc@@4.8}
7872 or @code{guile:debug}, or a file name in the store. Consider this
7876 $ guix size coreutils
7877 store item total self
7878 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
7879 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
7880 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
7881 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
7882 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
7883 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
7884 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
7885 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
7890 The store items listed here constitute the @dfn{transitive closure} of
7891 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
7892 would be returned by:
7895 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
7898 Here the output shows three columns next to store items. The first column,
7899 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
7900 the store item---that is, its own size plus the size of all its
7901 dependencies. The next column, labeled ``self'', shows the size of the
7902 item itself. The last column shows the ratio of the size of the item
7903 itself to the space occupied by all the items listed here.
7905 In this example, we see that the closure of Coreutils weighs in at
7906 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
7907 libraries. (That libc and GCC's libraries represent a large fraction of
7908 the closure is not a problem @i{per se} because they are always available
7909 on the system anyway.)
7911 When the package(s) passed to @command{guix size} are available in the
7912 store@footnote{More precisely, @command{guix size} looks for the
7913 @emph{ungrafted} variant of the given package(s), as returned by
7914 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
7915 for information on grafts.}, @command{guix size} queries the daemon to determine its
7916 dependencies, and measures its size in the store, similar to @command{du
7917 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
7920 When the given packages are @emph{not} in the store, @command{guix size}
7921 reports information based on the available substitutes
7922 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
7923 store items that are not even on disk, only available remotely.
7925 You can also specify several package names:
7928 $ guix size coreutils grep sed bash
7929 store item total self
7930 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
7931 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
7932 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
7933 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
7939 In this example we see that the combination of the four packages takes
7940 102.3@tie{}MiB in total, which is much less than the sum of each closure
7941 since they have a lot of dependencies in common.
7943 The available options are:
7947 @item --substitute-urls=@var{urls}
7948 Use substitute information from @var{urls}.
7949 @xref{client-substitute-urls, the same option for @code{guix build}}.
7951 @item --sort=@var{key}
7952 Sort lines according to @var{key}, one of the following options:
7956 the size of each item (the default);
7958 the total size of the item's closure.
7961 @item --map-file=@var{file}
7962 Write a graphical map of disk usage in PNG format to @var{file}.
7964 For the example above, the map looks like this:
7966 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
7967 produced by @command{guix size}}
7969 This option requires that
7970 @uref{http://wingolog.org/software/guile-charting/, Guile-Charting} be
7971 installed and visible in Guile's module search path. When that is not
7972 the case, @command{guix size} fails as it tries to load it.
7974 @item --system=@var{system}
7975 @itemx -s @var{system}
7976 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
7980 @node Invoking guix graph
7981 @section Invoking @command{guix graph}
7984 @cindex @command{guix graph}
7985 @cindex package dependencies
7986 Packages and their dependencies form a @dfn{graph}, specifically a
7987 directed acyclic graph (DAG). It can quickly become difficult to have a
7988 mental model of the package DAG, so the @command{guix graph} command
7989 provides a visual representation of the DAG. By default,
7990 @command{guix graph} emits a DAG representation in the input format of
7991 @uref{http://www.graphviz.org/, Graphviz}, so its output can be passed
7992 directly to the @command{dot} command of Graphviz. It can also emit an
7993 HTML page with embedded JavaScript code to display a ``chord diagram''
7994 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
7995 emit Cypher queries to construct a graph in a graph database supporting
7996 the @uref{http://www.opencypher.org/, openCypher} query language.
7997 The general syntax is:
8000 guix graph @var{options} @var{package}@dots{}
8003 For example, the following command generates a PDF file representing the
8004 package DAG for the GNU@tie{}Core Utilities, showing its build-time
8008 guix graph coreutils | dot -Tpdf > dag.pdf
8011 The output looks like this:
8013 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
8015 Nice little graph, no?
8017 But there is more than one graph! The one above is concise: it is the
8018 graph of package objects, omitting implicit inputs such as GCC, libc,
8019 grep, etc. It is often useful to have such a concise graph, but
8020 sometimes one may want to see more details. @command{guix graph} supports
8021 several types of graphs, allowing you to choose the level of detail:
8025 This is the default type used in the example above. It shows the DAG of
8026 package objects, excluding implicit dependencies. It is concise, but
8027 filters out many details.
8029 @item reverse-package
8030 This shows the @emph{reverse} DAG of packages. For example:
8033 guix graph --type=reverse-package ocaml
8036 ...@: yields the graph of packages that depend on OCaml.
8038 Note that for core packages this can yield huge graphs. If all you want
8039 is to know the number of packages that depend on a given package, use
8040 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
8041 @option{--list-dependent}}).
8044 This is the package DAG, @emph{including} implicit inputs.
8046 For instance, the following command:
8049 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
8052 ...@: yields this bigger graph:
8054 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
8056 At the bottom of the graph, we see all the implicit inputs of
8057 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
8059 Now, note that the dependencies of these implicit inputs---that is, the
8060 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
8061 here, for conciseness.
8064 Similar to @code{bag-emerged}, but this time including all the bootstrap
8067 @item bag-with-origins
8068 Similar to @code{bag}, but also showing origins and their dependencies.
8071 This is the most detailed representation: It shows the DAG of
8072 derivations (@pxref{Derivations}) and plain store items. Compared to
8073 the above representation, many additional nodes are visible, including
8074 build scripts, patches, Guile modules, etc.
8076 For this type of graph, it is also possible to pass a @file{.drv} file
8077 name instead of a package name, as in:
8080 guix graph -t derivation `guix system build -d my-config.scm`
8084 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
8085 For example, the following command shows the graph for the package
8086 module that defines the @code{guile} package:
8089 guix graph -t module guile | dot -Tpdf > module-graph.pdf
8093 All the types above correspond to @emph{build-time dependencies}. The
8094 following graph type represents the @emph{run-time dependencies}:
8098 This is the graph of @dfn{references} of a package output, as returned
8099 by @command{guix gc --references} (@pxref{Invoking guix gc}).
8101 If the given package output is not available in the store, @command{guix
8102 graph} attempts to obtain dependency information from substitutes.
8104 Here you can also pass a store file name instead of a package name. For
8105 example, the command below produces the reference graph of your profile
8106 (which can be big!):
8109 guix graph -t references `readlink -f ~/.guix-profile`
8113 This is the graph of the @dfn{referrers} of a store item, as returned by
8114 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
8116 This relies exclusively on local information from your store. For
8117 instance, let us suppose that the current Inkscape is available in 10
8118 profiles on your machine; @command{guix graph -t referrers inkscape}
8119 will show a graph rooted at Inkscape and with those 10 profiles linked
8122 It can help determine what is preventing a store item from being garbage
8127 The available options are the following:
8130 @item --type=@var{type}
8131 @itemx -t @var{type}
8132 Produce a graph output of @var{type}, where @var{type} must be one of
8133 the values listed above.
8136 List the supported graph types.
8138 @item --backend=@var{backend}
8139 @itemx -b @var{backend}
8140 Produce a graph using the selected @var{backend}.
8142 @item --list-backends
8143 List the supported graph backends.
8145 Currently, the available backends are Graphviz and d3.js.
8147 @item --expression=@var{expr}
8148 @itemx -e @var{expr}
8149 Consider the package @var{expr} evaluates to.
8151 This is useful to precisely refer to a package, as in this example:
8154 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
8157 @item --system=@var{system}
8158 @itemx -s @var{system}
8159 Display the graph for @var{system}---e.g., @code{i686-linux}.
8161 The package dependency graph is largely architecture-independent, but there
8162 are some architecture-dependent bits that this option allows you to visualize.
8166 @node Invoking guix environment
8167 @section Invoking @command{guix environment}
8169 @cindex reproducible build environments
8170 @cindex development environments
8171 @cindex @command{guix environment}
8172 @cindex environment, package build environment
8173 The purpose of @command{guix environment} is to assist hackers in
8174 creating reproducible development environments without polluting their
8175 package profile. The @command{guix environment} tool takes one or more
8176 packages, builds all of their inputs, and creates a shell
8177 environment to use them.
8179 The general syntax is:
8182 guix environment @var{options} @var{package}@dots{}
8185 The following example spawns a new shell set up for the development of
8189 guix environment guile
8192 If the needed dependencies are not built yet, @command{guix environment}
8193 automatically builds them. The environment of the new shell is an augmented
8194 version of the environment that @command{guix environment} was run in.
8195 It contains the necessary search paths for building the given package
8196 added to the existing environment variables. To create a ``pure''
8197 environment, in which the original environment variables have been unset,
8198 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
8199 environment variables such as @code{PATH} in their @file{~/.bashrc}
8200 file. As a consequence, when @code{guix environment} launches it, Bash
8201 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
8202 environment variables. It is an error to define such environment
8203 variables in @file{.bashrc}; instead, they should be defined in
8204 @file{.bash_profile}, which is sourced only by log-in shells.
8205 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
8206 details on Bash start-up files.}.
8208 @vindex GUIX_ENVIRONMENT
8209 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
8210 variable in the shell it spawns; its value is the file name of the
8211 profile of this environment. This allows users to, say, define a
8212 specific prompt for development environments in their @file{.bashrc}
8213 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
8216 if [ -n "$GUIX_ENVIRONMENT" ]
8218 export PS1="\u@@\h \w [dev]\$ "
8223 ...@: or to browse the profile:
8226 $ ls "$GUIX_ENVIRONMENT/bin"
8229 Additionally, more than one package may be specified, in which case the
8230 union of the inputs for the given packages are used. For example, the
8231 command below spawns a shell where all of the dependencies of both Guile
8232 and Emacs are available:
8235 guix environment guile emacs
8238 Sometimes an interactive shell session is not desired. An arbitrary
8239 command may be invoked by placing the @code{--} token to separate the
8240 command from the rest of the arguments:
8243 guix environment guile -- make -j4
8246 In other situations, it is more convenient to specify the list of
8247 packages needed in the environment. For example, the following command
8248 runs @command{python} from an environment containing Python@tie{}2.7 and
8252 guix environment --ad-hoc python2-numpy python-2.7 -- python
8255 Furthermore, one might want the dependencies of a package and also some
8256 additional packages that are not build-time or runtime dependencies, but
8257 are useful when developing nonetheless. Because of this, the
8258 @code{--ad-hoc} flag is positional. Packages appearing before
8259 @code{--ad-hoc} are interpreted as packages whose dependencies will be
8260 added to the environment. Packages appearing after are interpreted as
8261 packages that will be added to the environment directly. For example,
8262 the following command creates a Guix development environment that
8263 additionally includes Git and strace:
8266 guix environment guix --ad-hoc git strace
8269 Sometimes it is desirable to isolate the environment as much as
8270 possible, for maximal purity and reproducibility. In particular, when
8271 using Guix on a host distro that is not GuixSD, it is desirable to
8272 prevent access to @file{/usr/bin} and other system-wide resources from
8273 the development environment. For example, the following command spawns
8274 a Guile REPL in a ``container'' where only the store and the current
8275 working directory are mounted:
8278 guix environment --ad-hoc --container guile -- guile
8282 The @code{--container} option requires Linux-libre 3.19 or newer.
8285 The available options are summarized below.
8288 @item --root=@var{file}
8289 @itemx -r @var{file}
8290 @cindex persistent environment
8291 @cindex garbage collector root, for environments
8292 Make @var{file} a symlink to the profile for this environment, and
8293 register it as a garbage collector root.
8295 This is useful if you want to protect your environment from garbage
8296 collection, to make it ``persistent''.
8298 When this option is omitted, the environment is protected from garbage
8299 collection only for the duration of the @command{guix environment}
8300 session. This means that next time you recreate the same environment,
8301 you could have to rebuild or re-download packages. @xref{Invoking guix
8302 gc}, for more on GC roots.
8304 @item --expression=@var{expr}
8305 @itemx -e @var{expr}
8306 Create an environment for the package or list of packages that
8307 @var{expr} evaluates to.
8309 For example, running:
8312 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
8315 starts a shell with the environment for this specific variant of the
8321 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
8324 starts a shell with all the GuixSD base packages available.
8326 The above commands only use the default output of the given packages.
8327 To select other outputs, two element tuples can be specified:
8330 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
8333 @item --load=@var{file}
8334 @itemx -l @var{file}
8335 Create an environment for the package or list of packages that the code
8336 within @var{file} evaluates to.
8338 As an example, @var{file} might contain a definition like this
8339 (@pxref{Defining Packages}):
8342 @verbatiminclude environment-gdb.scm
8345 @item --manifest=@var{file}
8346 @itemx -m @var{file}
8347 Create an environment for the packages contained in the manifest object
8348 returned by the Scheme code in @var{file}.
8350 This is similar to the same-named option in @command{guix package}
8351 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
8355 Include all specified packages in the resulting environment, as if an
8356 @i{ad hoc} package were defined with them as inputs. This option is
8357 useful for quickly creating an environment without having to write a
8358 package expression to contain the desired inputs.
8360 For instance, the command:
8363 guix environment --ad-hoc guile guile-sdl -- guile
8366 runs @command{guile} in an environment where Guile and Guile-SDL are
8369 Note that this example implicitly asks for the default output of
8370 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
8371 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
8372 of @code{glib} (@pxref{Packages with Multiple Outputs}).
8374 This option may be composed with the default behavior of @command{guix
8375 environment}. Packages appearing before @code{--ad-hoc} are interpreted
8376 as packages whose dependencies will be added to the environment, the
8377 default behavior. Packages appearing after are interpreted as packages
8378 that will be added to the environment directly.
8381 Unset existing environment variables when building the new environment.
8382 This has the effect of creating an environment in which search paths
8383 only contain package inputs.
8385 @item --search-paths
8386 Display the environment variable definitions that make up the
8389 @item --system=@var{system}
8390 @itemx -s @var{system}
8391 Attempt to build for @var{system}---e.g., @code{i686-linux}.
8396 Run @var{command} within an isolated container. The current working
8397 directory outside the container is mapped inside the container.
8398 Additionally, unless overridden with @code{--user}, a dummy home
8399 directory is created that matches the current user's home directory, and
8400 @file{/etc/passwd} is configured accordingly. The spawned process runs
8401 as the current user outside the container, but has root privileges in
8402 the context of the container.
8406 For containers, share the network namespace with the host system.
8407 Containers created without this flag only have access to the loopback
8410 @item --link-profile
8412 For containers, link the environment profile to
8413 @file{~/.guix-profile} within the container. This is equivalent to
8414 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
8415 within the container. Linking will fail and abort the environment if
8416 the directory already exists, which will certainly be the case if
8417 @command{guix environment} was invoked in the user's home directory.
8419 Certain packages are configured to look in
8420 @code{~/.guix-profile} for configuration files and data;@footnote{For
8421 example, the @code{fontconfig} package inspects
8422 @file{~/.guix-profile/share/fonts} for additional fonts.}
8423 @code{--link-profile} allows these programs to behave as expected within
8426 @item --user=@var{user}
8427 @itemx -u @var{user}
8428 For containers, use the username @var{user} in place of the current
8429 user. The generated @file{/etc/passwd} entry within the container will
8430 contain the name @var{user}; the home directory will be
8431 @file{/home/USER}; and no user GECOS data will be copied. @var{user}
8432 need not exist on the system.
8434 Additionally, any shared or exposed path (see @code{--share} and
8435 @code{--expose} respectively) whose target is within the current user's
8436 home directory will be remapped relative to @file{/home/USER}; this
8437 includes the automatic mapping of the current working directory.
8440 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
8442 guix environment --container --user=foo \
8443 --expose=$HOME/test \
8444 --expose=/tmp/target=$HOME/target
8447 While this will limit the leaking of user identity through home paths
8448 and each of the user fields, this is only one useful component of a
8449 broader privacy/anonymity solution---not one in and of itself.
8451 @item --expose=@var{source}[=@var{target}]
8452 For containers, expose the file system @var{source} from the host system
8453 as the read-only file system @var{target} within the container. If
8454 @var{target} is not specified, @var{source} is used as the target mount
8455 point in the container.
8457 The example below spawns a Guile REPL in a container in which the user's
8458 home directory is accessible read-only via the @file{/exchange}
8462 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
8465 @item --share=@var{source}[=@var{target}]
8466 For containers, share the file system @var{source} from the host system
8467 as the writable file system @var{target} within the container. If
8468 @var{target} is not specified, @var{source} is used as the target mount
8469 point in the container.
8471 The example below spawns a Guile REPL in a container in which the user's
8472 home directory is accessible for both reading and writing via the
8473 @file{/exchange} directory:
8476 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
8480 @command{guix environment}
8481 also supports all of the common build options that @command{guix
8482 build} supports (@pxref{Common Build Options}) as well as package
8483 transformation options (@pxref{Package Transformation Options}).
8486 @node Invoking guix publish
8487 @section Invoking @command{guix publish}
8489 @cindex @command{guix publish}
8490 The purpose of @command{guix publish} is to enable users to easily share
8491 their store with others, who can then use it as a substitute server
8492 (@pxref{Substitutes}).
8494 When @command{guix publish} runs, it spawns an HTTP server which allows
8495 anyone with network access to obtain substitutes from it. This means
8496 that any machine running Guix can also act as if it were a build farm,
8497 since the HTTP interface is compatible with Hydra, the software behind
8498 the @code{@value{SUBSTITUTE-SERVER}} build farm.
8500 For security, each substitute is signed, allowing recipients to check
8501 their authenticity and integrity (@pxref{Substitutes}). Because
8502 @command{guix publish} uses the signing key of the system, which is only
8503 readable by the system administrator, it must be started as root; the
8504 @code{--user} option makes it drop root privileges early on.
8506 The signing key pair must be generated before @command{guix publish} is
8507 launched, using @command{guix archive --generate-key} (@pxref{Invoking
8510 The general syntax is:
8513 guix publish @var{options}@dots{}
8516 Running @command{guix publish} without any additional arguments will
8517 spawn an HTTP server on port 8080:
8523 Once a publishing server has been authorized (@pxref{Invoking guix
8524 archive}), the daemon may download substitutes from it:
8527 guix-daemon --substitute-urls=http://example.org:8080
8530 By default, @command{guix publish} compresses archives on the fly as it
8531 serves them. This ``on-the-fly'' mode is convenient in that it requires
8532 no setup and is immediately available. However, when serving lots of
8533 clients, we recommend using the @option{--cache} option, which enables
8534 caching of the archives before they are sent to clients---see below for
8535 details. The @command{guix weather} command provides a handy way to
8536 check what a server provides (@pxref{Invoking guix weather}).
8538 As a bonus, @command{guix publish} also serves as a content-addressed
8539 mirror for source files referenced in @code{origin} records
8540 (@pxref{origin Reference}). For instance, assuming @command{guix
8541 publish} is running on @code{example.org}, the following URL returns the
8542 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
8543 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
8546 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
8549 Obviously, these URLs only work for files that are in the store; in
8550 other cases, they return 404 (``Not Found'').
8552 @cindex build logs, publication
8553 Build logs are available from @code{/log} URLs like:
8556 http://example.org/log/gwspk@dots{}-guile-2.2.3
8560 When @command{guix-daemon} is configured to save compressed build logs,
8561 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
8562 URLs return the compressed log as-is, with an appropriate
8563 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
8564 running @command{guix-daemon} with @code{--log-compression=gzip} since
8565 Web browsers can automatically decompress it, which is not the case with
8568 The following options are available:
8571 @item --port=@var{port}
8572 @itemx -p @var{port}
8573 Listen for HTTP requests on @var{port}.
8575 @item --listen=@var{host}
8576 Listen on the network interface for @var{host}. The default is to
8577 accept connections from any interface.
8579 @item --user=@var{user}
8580 @itemx -u @var{user}
8581 Change privileges to @var{user} as soon as possible---i.e., once the
8582 server socket is open and the signing key has been read.
8584 @item --compression[=@var{level}]
8585 @itemx -C [@var{level}]
8586 Compress data using the given @var{level}. When @var{level} is zero,
8587 disable compression. The range 1 to 9 corresponds to different gzip
8588 compression levels: 1 is the fastest, and 9 is the best (CPU-intensive).
8591 Unless @option{--cache} is used, compression occurs on the fly and
8592 the compressed streams are not
8593 cached. Thus, to reduce load on the machine that runs @command{guix
8594 publish}, it may be a good idea to choose a low compression level, to
8595 run @command{guix publish} behind a caching proxy, or to use
8596 @option{--cache}. Using @option{--cache} has the advantage that it
8597 allows @command{guix publish} to add @code{Content-Length} HTTP header
8600 @item --cache=@var{directory}
8601 @itemx -c @var{directory}
8602 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
8603 and only serve archives that are in cache.
8605 When this option is omitted, archives and meta-data are created
8606 on-the-fly. This can reduce the available bandwidth, especially when
8607 compression is enabled, since this may become CPU-bound. Another
8608 drawback of the default mode is that the length of archives is not known
8609 in advance, so @command{guix publish} does not add a
8610 @code{Content-Length} HTTP header to its responses, which in turn
8611 prevents clients from knowing the amount of data being downloaded.
8613 Conversely, when @option{--cache} is used, the first request for a store
8614 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
8615 background process to @dfn{bake} the archive---computing its
8616 @code{.narinfo} and compressing the archive, if needed. Once the
8617 archive is cached in @var{directory}, subsequent requests succeed and
8618 are served directly from the cache, which guarantees that clients get
8619 the best possible bandwidth.
8621 The ``baking'' process is performed by worker threads. By default, one
8622 thread per CPU core is created, but this can be customized. See
8623 @option{--workers} below.
8625 When @option{--ttl} is used, cached entries are automatically deleted
8626 when they have expired.
8628 @item --workers=@var{N}
8629 When @option{--cache} is used, request the allocation of @var{N} worker
8630 threads to ``bake'' archives.
8632 @item --ttl=@var{ttl}
8633 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
8634 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
8635 days, @code{1m} means 1 month, and so on.
8637 This allows the user's Guix to keep substitute information in cache for
8638 @var{ttl}. However, note that @code{guix publish} does not itself
8639 guarantee that the store items it provides will indeed remain available
8640 for as long as @var{ttl}.
8642 Additionally, when @option{--cache} is used, cached entries that have
8643 not been accessed for @var{ttl} and that no longer have a corresponding
8644 item in the store, may be deleted.
8646 @item --nar-path=@var{path}
8647 Use @var{path} as the prefix for the URLs of ``nar'' files
8648 (@pxref{Invoking guix archive, normalized archives}).
8650 By default, nars are served at a URL such as
8651 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
8652 change the @code{/nar} part to @var{path}.
8654 @item --public-key=@var{file}
8655 @itemx --private-key=@var{file}
8656 Use the specific @var{file}s as the public/private key pair used to sign
8657 the store items being published.
8659 The files must correspond to the same key pair (the private key is used
8660 for signing and the public key is merely advertised in the signature
8661 metadata). They must contain keys in the canonical s-expression format
8662 as produced by @command{guix archive --generate-key} (@pxref{Invoking
8663 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
8664 @file{/etc/guix/signing-key.sec} are used.
8666 @item --repl[=@var{port}]
8667 @itemx -r [@var{port}]
8668 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
8669 Reference Manual}) on @var{port} (37146 by default). This is used
8670 primarily for debugging a running @command{guix publish} server.
8673 Enabling @command{guix publish} on a GuixSD system is a one-liner: just
8674 instantiate a @code{guix-publish-service-type} service in the @code{services} field
8675 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
8676 @code{guix-publish-service-type}}).
8678 If you are instead running Guix on a ``foreign distro'', follow these
8683 If your host distro uses the systemd init system:
8686 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
8687 /etc/systemd/system/
8688 # systemctl start guix-publish && systemctl enable guix-publish
8692 If your host distro uses the Upstart init system:
8695 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
8696 # start guix-publish
8700 Otherwise, proceed similarly with your distro's init system.
8703 @node Invoking guix challenge
8704 @section Invoking @command{guix challenge}
8706 @cindex reproducible builds
8707 @cindex verifiable builds
8708 @cindex @command{guix challenge}
8710 Do the binaries provided by this server really correspond to the source
8711 code it claims to build? Is a package build process deterministic?
8712 These are the questions the @command{guix challenge} command attempts to
8715 The former is obviously an important question: Before using a substitute
8716 server (@pxref{Substitutes}), one had better @emph{verify} that it
8717 provides the right binaries, and thus @emph{challenge} it. The latter
8718 is what enables the former: If package builds are deterministic, then
8719 independent builds of the package should yield the exact same result,
8720 bit for bit; if a server provides a binary different from the one
8721 obtained locally, it may be either corrupt or malicious.
8723 We know that the hash that shows up in @file{/gnu/store} file names is
8724 the hash of all the inputs of the process that built the file or
8725 directory---compilers, libraries, build scripts,
8726 etc. (@pxref{Introduction}). Assuming deterministic build processes,
8727 one store file name should map to exactly one build output.
8728 @command{guix challenge} checks whether there is, indeed, a single
8729 mapping by comparing the build outputs of several independent builds of
8730 any given store item.
8732 The command output looks like this:
8735 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
8736 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
8737 updating list of substitutes from 'https://guix.example.org'... 100.0%
8738 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
8739 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
8740 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
8741 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
8742 /gnu/store/@dots{}-git-2.5.0 contents differ:
8743 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
8744 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
8745 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
8746 /gnu/store/@dots{}-pius-2.1.1 contents differ:
8747 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
8748 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
8749 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
8753 6,406 store items were analyzed:
8754 - 4,749 (74.1%) were identical
8755 - 525 (8.2%) differed
8756 - 1,132 (17.7%) were inconclusive
8760 In this example, @command{guix challenge} first scans the store to
8761 determine the set of locally-built derivations---as opposed to store
8762 items that were downloaded from a substitute server---and then queries
8763 all the substitute servers. It then reports those store items for which
8764 the servers obtained a result different from the local build.
8766 @cindex non-determinism, in package builds
8767 As an example, @code{guix.example.org} always gets a different answer.
8768 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
8769 case of Git. This might indicate that the build process of Git is
8770 non-deterministic, meaning that its output varies as a function of
8771 various things that Guix does not fully control, in spite of building
8772 packages in isolated environments (@pxref{Features}). Most common
8773 sources of non-determinism include the addition of timestamps in build
8774 results, the inclusion of random numbers, and directory listings sorted
8775 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
8778 To find out what is wrong with this Git binary, we can do something along
8779 these lines (@pxref{Invoking guix archive}):
8782 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
8783 | guix archive -x /tmp/git
8784 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
8787 This command shows the difference between the files resulting from the
8788 local build, and the files resulting from the build on
8789 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
8790 diffutils, Comparing and Merging Files}). The @command{diff} command
8791 works great for text files. When binary files differ, a better option
8792 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
8793 visualize differences for all kinds of files.
8795 Once you have done that work, you can tell whether the differences are due
8796 to a non-deterministic build process or to a malicious server. We try
8797 hard to remove sources of non-determinism in packages to make it easier
8798 to verify substitutes, but of course, this is a process that
8799 involves not just Guix, but a large part of the free software community.
8800 In the meantime, @command{guix challenge} is one tool to help address
8803 If you are writing packages for Guix, you are encouraged to check
8804 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
8805 same build result as you did with:
8808 $ guix challenge @var{package}
8812 where @var{package} is a package specification such as
8813 @code{guile@@2.0} or @code{glibc:debug}.
8815 The general syntax is:
8818 guix challenge @var{options} [@var{packages}@dots{}]
8821 When a difference is found between the hash of a locally-built item and
8822 that of a server-provided substitute, or among substitutes provided by
8823 different servers, the command displays it as in the example above and
8824 its exit code is 2 (other non-zero exit codes denote other kinds of
8827 The one option that matters is:
8831 @item --substitute-urls=@var{urls}
8832 Consider @var{urls} the whitespace-separated list of substitute source
8837 Show details about matches (identical contents) in addition to
8838 information about mismatches.
8842 @node Invoking guix copy
8843 @section Invoking @command{guix copy}
8845 @cindex copy, of store items, over SSH
8846 @cindex SSH, copy of store items
8847 @cindex sharing store items across machines
8848 @cindex transferring store items across machines
8849 The @command{guix copy} command copies items from the store of one
8850 machine to that of another machine over a secure shell (SSH)
8851 connection@footnote{This command is available only when Guile-SSH was
8852 found. @xref{Requirements}, for details.}. For example, the following
8853 command copies the @code{coreutils} package, the user's profile, and all
8854 their dependencies over to @var{host}, logged in as @var{user}:
8857 guix copy --to=@var{user}@@@var{host} \
8858 coreutils `readlink -f ~/.guix-profile`
8861 If some of the items to be copied are already present on @var{host},
8862 they are not actually sent.
8864 The command below retrieves @code{libreoffice} and @code{gimp} from
8865 @var{host}, assuming they are available there:
8868 guix copy --from=@var{host} libreoffice gimp
8871 The SSH connection is established using the Guile-SSH client, which is
8872 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
8873 @file{~/.ssh/config}, and uses the SSH agent for authentication.
8875 The key used to sign items that are sent must be accepted by the remote
8876 machine. Likewise, the key used by the remote machine to sign items you
8877 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
8878 own daemon. @xref{Invoking guix archive}, for more information about
8879 store item authentication.
8881 The general syntax is:
8884 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
8887 You must always specify one of the following options:
8890 @item --to=@var{spec}
8891 @itemx --from=@var{spec}
8892 Specify the host to send to or receive from. @var{spec} must be an SSH
8893 spec such as @code{example.org}, @code{charlie@@example.org}, or
8894 @code{charlie@@example.org:2222}.
8897 The @var{items} can be either package names, such as @code{gimp}, or
8898 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
8900 When specifying the name of a package to send, it is first built if
8901 needed, unless @option{--dry-run} was specified. Common build options
8902 are supported (@pxref{Common Build Options}).
8905 @node Invoking guix container
8906 @section Invoking @command{guix container}
8908 @cindex @command{guix container}
8910 As of version @value{VERSION}, this tool is experimental. The interface
8911 is subject to radical change in the future.
8914 The purpose of @command{guix container} is to manipulate processes
8915 running within an isolated environment, commonly known as a
8916 ``container'', typically created by the @command{guix environment}
8917 (@pxref{Invoking guix environment}) and @command{guix system container}
8918 (@pxref{Invoking guix system}) commands.
8920 The general syntax is:
8923 guix container @var{action} @var{options}@dots{}
8926 @var{action} specifies the operation to perform with a container, and
8927 @var{options} specifies the context-specific arguments for the action.
8929 The following actions are available:
8933 Execute a command within the context of a running container.
8938 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
8941 @var{pid} specifies the process ID of the running container.
8942 @var{program} specifies an executable file name within the root file
8943 system of the container. @var{arguments} are the additional options that
8944 will be passed to @var{program}.
8946 The following command launches an interactive login shell inside a
8947 GuixSD container, started by @command{guix system container}, and whose
8951 guix container exec 9001 /run/current-system/profile/bin/bash --login
8954 Note that the @var{pid} cannot be the parent process of a container. It
8955 must be PID 1 of the container or one of its child processes.
8959 @node Invoking guix weather
8960 @section Invoking @command{guix weather}
8962 Occasionally you're grumpy because substitutes are lacking and you end
8963 up building packages by yourself (@pxref{Substitutes}). The
8964 @command{guix weather} command reports on substitute availability on the
8965 specified servers so you can have an idea of whether you'll be grumpy
8966 today. It can sometimes be useful info as a user, but it is primarily
8967 useful to people running @command{guix publish} (@pxref{Invoking guix
8970 @cindex statistics, for substitutes
8971 @cindex availability of substitutes
8972 @cindex substitute availability
8973 @cindex weather, substitute availability
8974 Here's a sample run:
8977 $ guix weather --substitute-urls=https://guix.example.org
8978 computing 5,872 package derivations for x86_64-linux...
8979 looking for 6,128 store items on https://guix.example.org..
8980 updating list of substitutes from 'https://guix.example.org'... 100.0%
8981 https://guix.example.org
8982 43.4% substitutes available (2,658 out of 6,128)
8983 7,032.5 MiB of nars (compressed)
8984 19,824.2 MiB on disk (uncompressed)
8985 0.030 seconds per request (182.9 seconds in total)
8986 33.5 requests per second
8988 9.8% (342 out of 3,470) of the missing items are queued
8990 x86_64-linux: 518 (59.7%)
8991 i686-linux: 221 (25.5%)
8992 aarch64-linux: 128 (14.8%)
8993 build rate: 23.41 builds per hour
8994 x86_64-linux: 11.16 builds per hour
8995 i686-linux: 6.03 builds per hour
8996 aarch64-linux: 6.41 builds per hour
8999 @cindex continuous integration, statistics
9000 As you can see, it reports the fraction of all the packages for which
9001 substitutes are available on the server---regardless of whether
9002 substitutes are enabled, and regardless of whether this server's signing
9003 key is authorized. It also reports the size of the compressed archives
9004 (``nars'') provided by the server, the size the corresponding store
9005 items occupy in the store (assuming deduplication is turned off), and
9006 the server's throughput. The second part gives continuous integration
9007 (CI) statistics, if the server supports it.
9009 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
9010 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
9011 challenge}, it ignores signatures on those substitutes, which is
9012 innocuous since the command only gathers statistics and cannot install
9015 Among other things, it is possible to query specific system types and
9016 specific package sets. The available options are listed below.
9019 @item --substitute-urls=@var{urls}
9020 @var{urls} is the space-separated list of substitute server URLs to
9021 query. When this option is omitted, the default set of substitute
9024 @item --system=@var{system}
9025 @itemx -s @var{system}
9026 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
9027 option can be repeated, in which case @command{guix weather} will query
9028 substitutes for several system types.
9030 @item --manifest=@var{file}
9031 Instead of querying substitutes for all the packages, only ask for those
9032 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
9033 with the @code{-m} option of @command{guix package} (@pxref{Invoking
9037 @node Invoking guix processes
9038 @section Invoking @command{guix processes}
9040 The @command{guix processes} command can be useful to developers and system
9041 administrators, especially on multi-user machines and on build farms: it lists
9042 the current sessions (connections to the daemon), as well as information about
9043 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
9044 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
9045 listed.}. Here's an example of the information it returns:
9048 $ sudo guix processes
9051 ClientCommand: guix environment --ad-hoc python
9055 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
9059 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
9060 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
9061 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
9062 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
9063 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
9064 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
9065 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
9068 In this example we see that @command{guix-daemon} has three clients:
9069 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
9070 integration tool; their process identifier (PID) is given by the
9071 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
9072 @command{guix-daemon} sub-process of this particular session.
9074 The @code{LockHeld} fields show which store items are currently locked by this
9075 session, which corresponds to store items being built or substituted (the
9076 @code{LockHeld} field is not displayed when @command{guix processes} is not
9077 running as root.) Last, by looking at the @code{ChildProcess} field, we
9078 understand that these three builds are being offloaded (@pxref{Daemon Offload
9081 The output is in Recutils format so we can use the handy @command{recsel}
9082 command to select sessions of interest (@pxref{Selection Expressions,,,
9083 recutils, GNU recutils manual}). As an example, the command shows the command
9084 line and PID of the client that triggered the build of a Perl package:
9087 $ sudo guix processes | \
9088 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
9090 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
9094 @node System Installation
9095 @chapter System Installation
9097 @cindex installing GuixSD
9098 @cindex Guix System Distribution
9099 This section explains how to install the Guix System Distribution (GuixSD)
9100 on a machine. The Guix package manager can
9101 also be installed on top of a running GNU/Linux system,
9102 @pxref{Installation}.
9106 @c This paragraph is for people reading this from tty2 of the
9107 @c installation image.
9108 You are reading this documentation with an Info reader. For details on
9109 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
9110 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
9111 Info}. Hit @kbd{l} afterwards to come back here.
9113 Alternately, run @command{info info} in another tty to keep the manual
9119 * Limitations:: What you can expect.
9120 * Hardware Considerations:: Supported hardware.
9121 * USB Stick and DVD Installation:: Preparing the installation medium.
9122 * Preparing for Installation:: Networking, partitioning, etc.
9123 * Proceeding with the Installation:: The real thing.
9124 * Installing GuixSD in a VM:: GuixSD playground.
9125 * Building the Installation Image:: How this comes to be.
9129 @section Limitations
9131 As of version @value{VERSION}, the Guix System Distribution (GuixSD) is
9132 not production-ready. It may contain bugs and lack important
9133 features. Thus, if you are looking for a stable production system that
9134 respects your freedom as a computer user, a good solution at this point
9135 is to consider @url{http://www.gnu.org/distros/free-distros.html, one of
9136 the more established GNU/Linux distributions}. We hope you can soon switch
9137 to the GuixSD without fear, of course. In the meantime, you can
9138 also keep using your distribution and try out the package manager on top
9139 of it (@pxref{Installation}).
9141 Before you proceed with the installation, be aware of the following
9142 noteworthy limitations applicable to version @value{VERSION}:
9146 The installation process does not include a graphical user interface and
9147 requires familiarity with GNU/Linux (see the following subsections to
9148 get a feel of what that means.)
9151 Support for the Logical Volume Manager (LVM) is missing.
9154 More and more system services are provided (@pxref{Services}), but some
9158 More than 8,500 packages are available, but you might
9159 occasionally find that a useful package is missing.
9162 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
9163 as well as a number of X11 window managers. However, some graphical
9164 applications may be missing, as well as KDE.
9167 You have been warned! But more than a disclaimer, this is an invitation
9168 to report issues (and success stories!), and to join us in improving it.
9169 @xref{Contributing}, for more info.
9172 @node Hardware Considerations
9173 @section Hardware Considerations
9175 @cindex hardware support on GuixSD
9176 GNU@tie{}GuixSD focuses on respecting the user's computing freedom. It
9177 builds around the kernel Linux-libre, which means that only hardware for
9178 which free software drivers and firmware exist is supported. Nowadays,
9179 a wide range of off-the-shelf hardware is supported on
9180 GNU/Linux-libre---from keyboards to graphics cards to scanners and
9181 Ethernet controllers. Unfortunately, there are still areas where
9182 hardware vendors deny users control over their own computing, and such
9183 hardware is not supported on GuixSD.
9185 @cindex WiFi, hardware support
9186 One of the main areas where free drivers or firmware are lacking is WiFi
9187 devices. WiFi devices known to work include those using Atheros chips
9188 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
9189 driver, and those using Broadcom/AirForce chips (BCM43xx with
9190 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
9191 Linux-libre driver. Free firmware exists for both and is available
9192 out-of-the-box on GuixSD, as part of @var{%base-firmware}
9193 (@pxref{operating-system Reference, @code{firmware}}).
9195 @cindex RYF, Respects Your Freedom
9196 The @uref{https://www.fsf.org/, Free Software Foundation} runs
9197 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
9198 certification program for hardware products that respect your freedom
9199 and your privacy and ensure that you have control over your device. We
9200 encourage you to check the list of RYF-certified devices.
9202 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
9203 web site. It contains a catalog of hardware devices with information
9204 about their support in GNU/Linux.
9207 @node USB Stick and DVD Installation
9208 @section USB Stick and DVD Installation
9210 An ISO-9660 installation image that can be written to a USB stick or
9211 burnt to a DVD can be downloaded from
9212 @indicateurl{https://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.iso.xz},
9213 where @var{system} is one of:
9217 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
9220 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
9223 @c start duplication of authentication part from ``Binary Installation''
9224 Make sure to download the associated @file{.sig} file and to verify the
9225 authenticity of the image against it, along these lines:
9228 $ wget https://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.iso.xz.sig
9229 $ gpg --verify guixsd-install-@value{VERSION}.@var{system}.iso.xz.sig
9232 If that command fails because you do not have the required public key,
9233 then run this command to import it:
9236 $ gpg --keyserver @value{KEY-SERVER} \
9237 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9241 and rerun the @code{gpg --verify} command.
9244 This image contains the tools necessary for an installation.
9245 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
9247 @unnumberedsubsec Copying to a USB Stick
9249 To copy the image to a USB stick, follow these steps:
9253 Decompress the image using the @command{xz} command:
9256 xz -d guixsd-install-@value{VERSION}.@var{system}.iso.xz
9260 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
9261 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
9262 copy the image with:
9265 dd if=guixsd-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
9269 Access to @file{/dev/sdX} usually requires root privileges.
9272 @unnumberedsubsec Burning on a DVD
9274 To copy the image to a DVD, follow these steps:
9278 Decompress the image using the @command{xz} command:
9281 xz -d guixsd-install-@value{VERSION}.@var{system}.iso.xz
9285 Insert a blank DVD into your machine, and determine
9286 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
9287 copy the image with:
9290 growisofs -dvd-compat -Z /dev/srX=guixsd-install-@value{VERSION}.@var{system}.iso
9293 Access to @file{/dev/srX} usually requires root privileges.
9296 @unnumberedsubsec Booting
9298 Once this is done, you should be able to reboot the system and boot from
9299 the USB stick or DVD. The latter usually requires you to get in the
9300 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
9302 @xref{Installing GuixSD in a VM}, if, instead, you would like to install
9303 GuixSD in a virtual machine (VM).
9306 @node Preparing for Installation
9307 @section Preparing for Installation
9309 Once you have successfully booted your computer using the installation medium,
9310 you should end up with the welcome page of the graphical installer. The
9311 graphical installer is a text-based user interface built upon the newt
9312 library. It shall guide you through all the different steps needed to install
9313 GNU GuixSD. However, as the graphical installer is still under heavy
9314 development, you might want to fallback to the original, shell based install
9315 process, by switching to TTYs 3 to 6 with the shortcuts CTRL-ALT-F[3-6]. The
9316 following sections describe the installation procedure assuming you're using
9317 one of those TTYs. They are configured and can be used to run commands as
9320 TTY2 shows this documentation, browsable using the Info reader commands
9321 (@pxref{Top,,, info-stnd, Stand-alone GNU Info}). The installation system
9322 runs the GPM mouse daemon, which allows you to select text with the left mouse
9323 button and to paste it with the middle button.
9326 Installation requires access to the Internet so that any missing
9327 dependencies of your system configuration can be downloaded. See the
9328 ``Networking'' section below.
9331 The installation system includes many common tools needed for this task.
9332 But it is also a full-blown GuixSD system, which means that you can
9333 install additional packages, should you need it, using @command{guix
9334 package} (@pxref{Invoking guix package}).
9336 @subsection Keyboard Layout
9338 @cindex keyboard layout
9339 The installation image uses the US qwerty keyboard layout. If you want
9340 to change it, you can use the @command{loadkeys} command. For example,
9341 the following command selects the Dvorak keyboard layout:
9347 See the files under @file{/run/current-system/profile/share/keymaps} for
9348 a list of available keyboard layouts. Run @command{man loadkeys} for
9351 @subsection Networking
9353 Run the following command to see what your network interfaces are called:
9360 @dots{} or, using the GNU/Linux-specific @command{ip} command:
9366 @c http://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
9367 Wired interfaces have a name starting with @samp{e}; for example, the
9368 interface corresponding to the first on-board Ethernet controller is
9369 called @samp{eno1}. Wireless interfaces have a name starting with
9370 @samp{w}, like @samp{w1p2s0}.
9373 @item Wired connection
9374 To configure a wired network run the following command, substituting
9375 @var{interface} with the name of the wired interface you want to use.
9378 ifconfig @var{interface} up
9381 @item Wireless connection
9384 To configure wireless networking, you can create a configuration file
9385 for the @command{wpa_supplicant} configuration tool (its location is not
9386 important) using one of the available text editors such as
9390 nano wpa_supplicant.conf
9393 As an example, the following stanza can go to this file and will work
9394 for many wireless networks, provided you give the actual SSID and
9395 passphrase for the network you are connecting to:
9399 ssid="@var{my-ssid}"
9401 psk="the network's secret passphrase"
9405 Start the wireless service and run it in the background with the
9406 following command (substitute @var{interface} with the name of the
9407 network interface you want to use):
9410 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
9413 Run @command{man wpa_supplicant} for more information.
9417 At this point, you need to acquire an IP address. On a network where IP
9418 addresses are automatically assigned @i{via} DHCP, you can run:
9421 dhclient -v @var{interface}
9424 Try to ping a server to see if networking is up and running:
9430 Setting up network access is almost always a requirement because the
9431 image does not contain all the software and tools that may be needed.
9433 @cindex installing over SSH
9434 If you want to, you can continue the installation remotely by starting
9438 herd start ssh-daemon
9441 Make sure to either set a password with @command{passwd}, or configure
9442 OpenSSH public key authentication before logging in.
9444 @subsection Disk Partitioning
9446 Unless this has already been done, the next step is to partition, and
9447 then format the target partition(s).
9449 The installation image includes several partitioning tools, including
9450 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
9451 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
9452 the partition layout you want:
9458 If your disk uses the GUID Partition Table (GPT) format and you plan to
9459 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
9460 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
9463 @cindex EFI, installation
9464 @cindex UEFI, installation
9465 @cindex ESP, EFI system partition
9466 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
9467 (ESP) is required. This partition should be mounted at @file{/boot/efi} and
9468 must have the @code{esp} flag set. E.g., for @command{parted}:
9471 parted /dev/sda set 1 esp on
9475 @vindex grub-bootloader
9476 @vindex grub-efi-bootloader
9477 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
9478 @file{/sys/firmware/efi} exists in the installation image, then you should
9479 probably perform an EFI installation, using @code{grub-efi-bootloader}.
9480 Otherwise you should use the BIOS-based GRUB, known as
9481 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
9485 Once you are done partitioning the target hard disk drive, you have to
9486 create a file system on the relevant partition(s)@footnote{Currently
9487 GuixSD only supports ext4 and btrfs file systems. In particular, code
9488 that reads file system UUIDs and labels only works for these file system
9489 types.}. For the ESP, if you have one and assuming it is
9490 @file{/dev/sda1}, run:
9493 mkfs.fat -F32 /dev/sda1
9496 Preferably, assign file systems a label so that you can easily and
9497 reliably refer to them in @code{file-system} declarations (@pxref{File
9498 Systems}). This is typically done using the @code{-L} option of
9499 @command{mkfs.ext4} and related commands. So, assuming the target root
9500 partition lives at @file{/dev/sda2}, a file system with the label
9501 @code{my-root} can be created with:
9504 mkfs.ext4 -L my-root /dev/sda2
9507 @cindex encrypted disk
9508 If you are instead planning to encrypt the root partition, you can use
9509 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
9510 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
9511 @code{man cryptsetup}} for more information.) Assuming you want to
9512 store the root partition on @file{/dev/sda2}, the command sequence would
9513 be along these lines:
9516 cryptsetup luksFormat /dev/sda2
9517 cryptsetup open --type luks /dev/sda2 my-partition
9518 mkfs.ext4 -L my-root /dev/mapper/my-partition
9521 Once that is done, mount the target file system under @file{/mnt}
9522 with a command like (again, assuming @code{my-root} is the label of the
9526 mount LABEL=my-root /mnt
9529 Also mount any other file systems you would like to use on the target
9530 system relative to this path. If you have @file{/boot} on a separate
9531 partition for example, mount it at @file{/mnt/boot} now so it is found
9532 by @code{guix system init} afterwards.
9534 Finally, if you plan to use one or more swap partitions (@pxref{Memory
9535 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
9536 sure to initialize them with @command{mkswap}. Assuming you have one
9537 swap partition on @file{/dev/sda3}, you would run:
9544 Alternatively, you may use a swap file. For example, assuming that in
9545 the new system you want to use the file @file{/swapfile} as a swap file,
9546 you would run@footnote{This example will work for many types of file
9547 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
9548 btrfs), the required steps may be different. For details, see the
9549 manual pages for @command{mkswap} and @command{swapon}.}:
9552 # This is 10 GiB of swap space. Adjust "count" to change the size.
9553 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
9554 # For security, make the file readable and writable only by root.
9555 chmod 600 /mnt/swapfile
9556 mkswap /mnt/swapfile
9557 swapon /mnt/swapfile
9560 Note that if you have encrypted the root partition and created a swap
9561 file in its file system as described above, then the encryption also
9562 protects the swap file, just like any other file in that file system.
9564 @node Proceeding with the Installation
9565 @section Proceeding with the Installation
9567 With the target partitions ready and the target root mounted on
9568 @file{/mnt}, we're ready to go. First, run:
9571 herd start cow-store /mnt
9574 This makes @file{/gnu/store} copy-on-write, such that packages added to it
9575 during the installation phase are written to the target disk on @file{/mnt}
9576 rather than kept in memory. This is necessary because the first phase of
9577 the @command{guix system init} command (see below) entails downloads or
9578 builds to @file{/gnu/store} which, initially, is an in-memory file system.
9580 Next, you have to edit a file and
9581 provide the declaration of the operating system to be installed. To
9582 that end, the installation system comes with three text editors. We
9583 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
9584 supports syntax highlighting and parentheses matching; other editors
9585 include GNU Zile (an Emacs clone), and
9586 nvi (a clone of the original BSD @command{vi} editor).
9587 We strongly recommend storing that file on the target root file system, say,
9588 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
9589 configuration file once you have rebooted into the newly-installed system.
9591 @xref{Using the Configuration System}, for an overview of the
9592 configuration file. The example configurations discussed in that
9593 section are available under @file{/etc/configuration} in the
9594 installation image. Thus, to get started with a system configuration
9595 providing a graphical display server (a ``desktop'' system), you can run
9596 something along these lines:
9600 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
9601 # nano /mnt/etc/config.scm
9604 You should pay attention to what your configuration file contains, and
9609 Make sure the @code{bootloader-configuration} form refers to the target
9610 you want to install GRUB on. It should mention @code{grub-bootloader} if
9611 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
9612 for newer UEFI systems. For legacy systems, the @code{target} field
9613 names a device, like @code{/dev/sda}; for UEFI systems it names a path
9614 to a mounted EFI partition, like @code{/boot/efi}, and do make sure the
9615 path is actually mounted.
9618 Be sure that your file system labels match the value of their respective
9619 @code{device} fields in your @code{file-system} configuration, assuming
9620 your @code{file-system} configuration uses the @code{file-system-label}
9621 procedure in its @code{device} field.
9624 If there are encrypted or RAID partitions, make sure to add a
9625 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
9628 Once you are done preparing the configuration file, the new system must
9629 be initialized (remember that the target root file system is mounted
9633 guix system init /mnt/etc/config.scm /mnt
9637 This copies all the necessary files and installs GRUB on
9638 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
9639 more information, @pxref{Invoking guix system}. This command may trigger
9640 downloads or builds of missing packages, which can take some time.
9642 Once that command has completed---and hopefully succeeded!---you can run
9643 @command{reboot} and boot into the new system. The @code{root} password
9644 in the new system is initially empty; other users' passwords need to be
9645 initialized by running the @command{passwd} command as @code{root},
9646 unless your configuration specifies otherwise
9647 (@pxref{user-account-password, user account passwords}).
9649 @cindex upgrading GuixSD
9650 From then on, you can update GuixSD whenever you want by running @command{guix
9651 pull} as @code{root} (@pxref{Invoking guix pull}), and then running
9652 @command{guix system reconfigure /etc/config.scm}, as @code{root} too, to
9653 build a new system generation with the latest packages and services
9654 (@pxref{Invoking guix system}). We recommend doing that regularly so that
9655 your system includes the latest security updates (@pxref{Security Updates}).
9657 Join us on @code{#guix} on the Freenode IRC network or on
9658 @email{guix-devel@@gnu.org} to share your experience---good or not so
9661 @node Installing GuixSD in a VM
9662 @section Installing GuixSD in a Virtual Machine
9664 @cindex virtual machine, GuixSD installation
9665 @cindex virtual private server (VPS)
9666 @cindex VPS (virtual private server)
9667 If you'd like to install GuixSD in a virtual machine (VM) or on a
9668 virtual private server (VPS) rather than on your beloved machine, this
9671 To boot a @uref{http://qemu.org/,QEMU} VM for installing GuixSD in a
9672 disk image, follow these steps:
9676 First, retrieve and decompress the GuixSD installation image as
9677 described previously (@pxref{USB Stick and DVD Installation}).
9680 Create a disk image that will hold the installed system. To make a
9681 qcow2-formatted disk image, use the @command{qemu-img} command:
9684 qemu-img create -f qcow2 guixsd.img 50G
9687 The resulting file will be much smaller than 50 GB (typically less than
9688 1 MB), but it will grow as the virtualized storage device is filled up.
9691 Boot the USB installation image in an VM:
9694 qemu-system-x86_64 -m 1024 -smp 1 \
9695 -net user -net nic,model=virtio -boot menu=on \
9696 -drive file=guixsd-install-@value{VERSION}.@var{system}.iso \
9697 -drive file=guixsd.img
9700 The ordering of the drives matters.
9702 In the VM console, quickly press the @kbd{F12} key to enter the boot
9703 menu. Then press the @kbd{2} key and the @kbd{RET} key to validate your
9707 You're now root in the VM, proceed with the installation process.
9708 @xref{Preparing for Installation}, and follow the instructions.
9711 Once installation is complete, you can boot the system that's on your
9712 @file{guixsd.img} image. @xref{Running GuixSD in a VM}, for how to do
9715 @node Building the Installation Image
9716 @section Building the Installation Image
9718 @cindex installation image
9719 The installation image described above was built using the @command{guix
9720 system} command, specifically:
9723 guix system disk-image gnu/system/install.scm
9726 Have a look at @file{gnu/system/install.scm} in the source tree,
9727 and see also @ref{Invoking guix system} for more information
9728 about the installation image.
9730 @section Building the Installation Image for ARM Boards
9732 Many ARM boards require a specific variant of the
9733 @uref{http://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
9735 If you build a disk image and the bootloader is not available otherwise
9736 (on another boot drive etc), it's advisable to build an image that
9737 includes the bootloader, specifically:
9740 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
9743 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
9744 board, a list of possible boards will be printed.
9746 @node System Configuration
9747 @chapter System Configuration
9749 @cindex system configuration
9750 The Guix System Distribution supports a consistent whole-system configuration
9751 mechanism. By that we mean that all aspects of the global system
9752 configuration---such as the available system services, timezone and
9753 locale settings, user accounts---are declared in a single place. Such
9754 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
9756 One of the advantages of putting all the system configuration under the
9757 control of Guix is that it supports transactional system upgrades, and
9758 makes it possible to roll back to a previous system instantiation,
9759 should something go wrong with the new one (@pxref{Features}). Another
9760 advantage is that it makes it easy to replicate the exact same configuration
9761 across different machines, or at different points in time, without
9762 having to resort to additional administration tools layered on top of
9763 the own tools of the system.
9764 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
9766 This section describes this mechanism. First we focus on the system
9767 administrator's viewpoint---explaining how the system is configured and
9768 instantiated. Then we show how this mechanism can be extended, for
9769 instance to support new system services.
9772 * Using the Configuration System:: Customizing your GNU system.
9773 * operating-system Reference:: Detail of operating-system declarations.
9774 * File Systems:: Configuring file system mounts.
9775 * Mapped Devices:: Block device extra processing.
9776 * User Accounts:: Specifying user accounts.
9777 * Locales:: Language and cultural convention settings.
9778 * Services:: Specifying system services.
9779 * Setuid Programs:: Programs running with root privileges.
9780 * X.509 Certificates:: Authenticating HTTPS servers.
9781 * Name Service Switch:: Configuring libc's name service switch.
9782 * Initial RAM Disk:: Linux-Libre bootstrapping.
9783 * Bootloader Configuration:: Configuring the boot loader.
9784 * Invoking guix system:: Instantiating a system configuration.
9785 * Running GuixSD in a VM:: How to run GuixSD in a virtual machine.
9786 * Defining Services:: Adding new service definitions.
9789 @node Using the Configuration System
9790 @section Using the Configuration System
9792 The operating system is configured by providing an
9793 @code{operating-system} declaration in a file that can then be passed to
9794 the @command{guix system} command (@pxref{Invoking guix system}). A
9795 simple setup, with the default system services, the default Linux-Libre
9796 kernel, initial RAM disk, and boot loader looks like this:
9798 @findex operating-system
9800 @include os-config-bare-bones.texi
9803 This example should be self-describing. Some of the fields defined
9804 above, such as @code{host-name} and @code{bootloader}, are mandatory.
9805 Others, such as @code{packages} and @code{services}, can be omitted, in
9806 which case they get a default value.
9808 Below we discuss the effect of some of the most important fields
9809 (@pxref{operating-system Reference}, for details about all the available
9810 fields), and how to @dfn{instantiate} the operating system using
9811 @command{guix system}.
9813 @unnumberedsubsec Bootloader
9815 @cindex legacy boot, on Intel machines
9816 @cindex BIOS boot, on Intel machines
9819 The @code{bootloader} field describes the method that will be used to boot
9820 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
9821 mode, as in the example above. However, more recent machines rely instead on
9822 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
9823 the @code{bootloader} field should contain something along these lines:
9826 (bootloader-configuration
9827 (bootloader grub-efi-bootloader)
9828 (target "/boot/efi"))
9831 @xref{Bootloader Configuration}, for more information on the available
9832 configuration options.
9834 @unnumberedsubsec Globally-Visible Packages
9836 @vindex %base-packages
9837 The @code{packages} field lists packages that will be globally visible
9838 on the system, for all user accounts---i.e., in every user's @code{PATH}
9839 environment variable---in addition to the per-user profiles
9840 (@pxref{Invoking guix package}). The @var{%base-packages} variable
9841 provides all the tools one would expect for basic user and administrator
9842 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
9843 the GNU Zile lightweight text editor, @command{find}, @command{grep},
9844 etc. The example above adds GNU@tie{}Screen to those,
9845 taken from the @code{(gnu packages screen)}
9846 module (@pxref{Package Modules}). The
9847 @code{(list package output)} syntax can be used to add a specific output
9851 (use-modules (gnu packages))
9852 (use-modules (gnu packages dns))
9856 (packages (cons (list bind "utils")
9860 @findex specification->package
9861 Referring to packages by variable name, like @code{bind} above, has
9862 the advantage of being unambiguous; it also allows typos and such to be
9863 diagnosed right away as ``unbound variables''. The downside is that one
9864 needs to know which module defines which package, and to augment the
9865 @code{use-package-modules} line accordingly. To avoid that, one can use
9866 the @code{specification->package} procedure of the @code{(gnu packages)}
9867 module, which returns the best package for a given name or name and
9871 (use-modules (gnu packages))
9875 (packages (append (map specification->package
9876 '("tcpdump" "htop" "gnupg@@2.0"))
9880 @unnumberedsubsec System Services
9883 @vindex %base-services
9884 The @code{services} field lists @dfn{system services} to be made
9885 available when the system starts (@pxref{Services}).
9886 The @code{operating-system} declaration above specifies that, in
9887 addition to the basic services, we want the @command{lshd} secure shell
9888 daemon listening on port 2222 (@pxref{Networking Services,
9889 @code{lsh-service}}). Under the hood,
9890 @code{lsh-service} arranges so that @code{lshd} is started with the
9891 right command-line options, possibly with supporting configuration files
9892 generated as needed (@pxref{Defining Services}).
9894 @cindex customization, of services
9895 @findex modify-services
9896 Occasionally, instead of using the base services as is, you will want to
9897 customize them. To do this, use @code{modify-services} (@pxref{Service
9898 Reference, @code{modify-services}}) to modify the list.
9900 For example, suppose you want to modify @code{guix-daemon} and Mingetty
9901 (the console log-in) in the @var{%base-services} list (@pxref{Base
9902 Services, @code{%base-services}}). To do that, you can write the
9903 following in your operating system declaration:
9906 (define %my-services
9907 ;; My very own list of services.
9908 (modify-services %base-services
9909 (guix-service-type config =>
9912 (use-substitutes? #f)
9913 (extra-options '("--gc-keep-derivations"))))
9914 (mingetty-service-type config =>
9915 (mingetty-configuration
9916 (inherit config)))))
9920 (services %my-services))
9923 This changes the configuration---i.e., the service parameters---of the
9924 @code{guix-service-type} instance, and that of all the
9925 @code{mingetty-service-type} instances in the @var{%base-services} list.
9926 Observe how this is accomplished: first, we arrange for the original
9927 configuration to be bound to the identifier @code{config} in the
9928 @var{body}, and then we write the @var{body} so that it evaluates to the
9929 desired configuration. In particular, notice how we use @code{inherit}
9930 to create a new configuration which has the same values as the old
9931 configuration, but with a few modifications.
9933 @cindex encrypted disk
9934 The configuration for a typical ``desktop'' usage, with an encrypted
9935 root partition, the X11 display
9936 server, GNOME and Xfce (users can choose which of these desktop
9937 environments to use at the log-in screen by pressing @kbd{F1}), network
9938 management, power management, and more, would look like this:
9941 @include os-config-desktop.texi
9944 A graphical system with a choice of lightweight window managers
9945 instead of full-blown desktop environments would look like this:
9948 @include os-config-lightweight-desktop.texi
9951 This example refers to the @file{/boot/efi} file system by its UUID,
9952 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
9953 as returned by the @command{blkid} command.
9955 @xref{Desktop Services}, for the exact list of services provided by
9956 @var{%desktop-services}. @xref{X.509 Certificates}, for background
9957 information about the @code{nss-certs} package that is used here.
9959 Again, @var{%desktop-services} is just a list of service objects. If
9960 you want to remove services from there, you can do so using the
9961 procedures for list filtering (@pxref{SRFI-1 Filtering and
9962 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
9963 following expression returns a list that contains all the services in
9964 @var{%desktop-services} minus the Avahi service:
9967 (remove (lambda (service)
9968 (eq? (service-kind service) avahi-service-type))
9972 @unnumberedsubsec Instantiating the System
9974 Assuming the @code{operating-system} declaration
9975 is stored in the @file{my-system-config.scm}
9976 file, the @command{guix system reconfigure my-system-config.scm} command
9977 instantiates that configuration, and makes it the default GRUB boot
9978 entry (@pxref{Invoking guix system}).
9980 The normal way to change the system configuration is by updating this
9981 file and re-running @command{guix system reconfigure}. One should never
9982 have to touch files in @file{/etc} or to run commands that modify the
9983 system state such as @command{useradd} or @command{grub-install}. In
9984 fact, you must avoid that since that would not only void your warranty
9985 but also prevent you from rolling back to previous versions of your
9986 system, should you ever need to.
9988 @cindex roll-back, of the operating system
9989 Speaking of roll-back, each time you run @command{guix system
9990 reconfigure}, a new @dfn{generation} of the system is created---without
9991 modifying or deleting previous generations. Old system generations get
9992 an entry in the bootloader boot menu, allowing you to boot them in case
9993 something went wrong with the latest generation. Reassuring, no? The
9994 @command{guix system list-generations} command lists the system
9995 generations available on disk. It is also possible to roll back the
9996 system via the commands @command{guix system roll-back} and
9997 @command{guix system switch-generation}.
9999 Although the @command{guix system reconfigure} command will not modify
10000 previous generations, you must take care when the current generation is not
10001 the latest (e.g., after invoking @command{guix system roll-back}), since
10002 the operation might overwrite a later generation (@pxref{Invoking guix
10005 @unnumberedsubsec The Programming Interface
10007 At the Scheme level, the bulk of an @code{operating-system} declaration
10008 is instantiated with the following monadic procedure (@pxref{The Store
10011 @deffn {Monadic Procedure} operating-system-derivation os
10012 Return a derivation that builds @var{os}, an @code{operating-system}
10013 object (@pxref{Derivations}).
10015 The output of the derivation is a single directory that refers to all
10016 the packages, configuration files, and other supporting files needed to
10017 instantiate @var{os}.
10020 This procedure is provided by the @code{(gnu system)} module. Along
10021 with @code{(gnu services)} (@pxref{Services}), this module contains the
10022 guts of GuixSD. Make sure to visit it!
10025 @node operating-system Reference
10026 @section @code{operating-system} Reference
10028 This section summarizes all the options available in
10029 @code{operating-system} declarations (@pxref{Using the Configuration
10032 @deftp {Data Type} operating-system
10033 This is the data type representing an operating system configuration.
10034 By that, we mean all the global system configuration, not per-user
10035 configuration (@pxref{Using the Configuration System}).
10038 @item @code{kernel} (default: @var{linux-libre})
10039 The package object of the operating system kernel to use@footnote{Currently
10040 only the Linux-libre kernel is supported. In the future, it will be
10041 possible to use the GNU@tie{}Hurd.}.
10043 @item @code{kernel-arguments} (default: @code{'()})
10044 List of strings or gexps representing additional arguments to pass on
10045 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
10047 @item @code{bootloader}
10048 The system bootloader configuration object. @xref{Bootloader Configuration}.
10050 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
10052 @cindex initial RAM disk
10053 The list of Linux kernel modules that need to be available in the
10054 initial RAM disk. @xref{Initial RAM Disk}.
10056 @item @code{initrd} (default: @code{base-initrd})
10057 A procedure that returns an initial RAM disk for the Linux
10058 kernel. This field is provided to support low-level customization and
10059 should rarely be needed for casual use. @xref{Initial RAM Disk}.
10061 @item @code{firmware} (default: @var{%base-firmware})
10063 List of firmware packages loadable by the operating system kernel.
10065 The default includes firmware needed for Atheros- and Broadcom-based
10066 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
10067 respectively). @xref{Hardware Considerations}, for more info on
10068 supported hardware.
10070 @item @code{host-name}
10073 @item @code{hosts-file}
10075 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
10076 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
10077 Reference Manual}). The default is a file with entries for
10078 @code{localhost} and @var{host-name}.
10080 @item @code{mapped-devices} (default: @code{'()})
10081 A list of mapped devices. @xref{Mapped Devices}.
10083 @item @code{file-systems}
10084 A list of file systems. @xref{File Systems}.
10086 @item @code{swap-devices} (default: @code{'()})
10087 @cindex swap devices
10088 A list of strings identifying devices or files to be used for ``swap
10089 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
10090 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
10091 It is possible to specify a swap file in a file system on a mapped
10092 device, provided that the necessary device mapping and file system are
10093 also specified. @xref{Mapped Devices} and @ref{File Systems}.
10095 @item @code{users} (default: @code{%base-user-accounts})
10096 @itemx @code{groups} (default: @var{%base-groups})
10097 List of user accounts and groups. @xref{User Accounts}.
10099 If the @code{users} list lacks a user account with UID@tie{}0, a
10100 ``root'' account with UID@tie{}0 is automatically added.
10102 @item @code{skeletons} (default: @code{(default-skeletons)})
10103 A list target file name/file-like object tuples (@pxref{G-Expressions,
10104 file-like objects}). These are the skeleton files that will be added to
10105 the home directory of newly-created user accounts.
10107 For instance, a valid value may look like this:
10110 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
10111 (".guile" ,(plain-file "guile"
10112 "(use-modules (ice-9 readline))
10113 (activate-readline)")))
10116 @item @code{issue} (default: @var{%default-issue})
10117 A string denoting the contents of the @file{/etc/issue} file, which is
10118 displayed when users log in on a text console.
10120 @item @code{packages} (default: @var{%base-packages})
10121 The set of packages installed in the global profile, which is accessible
10122 at @file{/run/current-system/profile}.
10124 The default set includes core utilities and it is good practice to
10125 install non-core utilities in user profiles (@pxref{Invoking guix
10128 @item @code{timezone}
10129 A timezone identifying string---e.g., @code{"Europe/Paris"}.
10131 You can run the @command{tzselect} command to find out which timezone
10132 string corresponds to your region. Choosing an invalid timezone name
10133 causes @command{guix system} to fail.
10135 @item @code{locale} (default: @code{"en_US.utf8"})
10136 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
10137 Library Reference Manual}). @xref{Locales}, for more information.
10139 @item @code{locale-definitions} (default: @var{%default-locale-definitions})
10140 The list of locale definitions to be compiled and that may be used at
10141 run time. @xref{Locales}.
10143 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
10144 The list of GNU@tie{}libc packages whose locale data and tools are used
10145 to build the locale definitions. @xref{Locales}, for compatibility
10146 considerations that justify this option.
10148 @item @code{name-service-switch} (default: @var{%default-nss})
10149 Configuration of the libc name service switch (NSS)---a
10150 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
10153 @item @code{services} (default: @var{%base-services})
10154 A list of service objects denoting system services. @xref{Services}.
10156 @item @code{pam-services} (default: @code{(base-pam-services)})
10158 @cindex pluggable authentication modules
10159 Linux @dfn{pluggable authentication module} (PAM) services.
10160 @c FIXME: Add xref to PAM services section.
10162 @item @code{setuid-programs} (default: @var{%setuid-programs})
10163 List of string-valued G-expressions denoting setuid programs.
10164 @xref{Setuid Programs}.
10166 @item @code{sudoers-file} (default: @var{%sudoers-specification})
10167 @cindex sudoers file
10168 The contents of the @file{/etc/sudoers} file as a file-like object
10169 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
10171 This file specifies which users can use the @command{sudo} command, what
10172 they are allowed to do, and what privileges they may gain. The default
10173 is that only @code{root} and members of the @code{wheel} group may use
10180 @section File Systems
10182 The list of file systems to be mounted is specified in the
10183 @code{file-systems} field of the operating system declaration
10184 (@pxref{Using the Configuration System}). Each file system is declared
10185 using the @code{file-system} form, like this:
10189 (mount-point "/home")
10190 (device "/dev/sda3")
10194 As usual, some of the fields are mandatory---those shown in the example
10195 above---while others can be omitted. These are described below.
10197 @deftp {Data Type} file-system
10198 Objects of this type represent file systems to be mounted. They
10199 contain the following members:
10203 This is a string specifying the type of the file system---e.g.,
10206 @item @code{mount-point}
10207 This designates the place where the file system is to be mounted.
10209 @item @code{device}
10210 This names the ``source'' of the file system. It can be one of three
10211 things: a file system label, a file system UUID, or the name of a
10212 @file{/dev} node. Labels and UUIDs offer a way to refer to file
10213 systems without having to hard-code their actual device
10214 name@footnote{Note that, while it is tempting to use
10215 @file{/dev/disk/by-uuid} and similar device names to achieve the same
10216 result, this is not recommended: These special device nodes are created
10217 by the udev daemon and may be unavailable at the time the device is
10220 @findex file-system-label
10221 File system labels are created using the @code{file-system-label}
10222 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
10223 plain strings. Here's an example of a file system referred to by its
10224 label, as shown by the @command{e2label} command:
10228 (mount-point "/home")
10230 (device (file-system-label "my-home")))
10234 UUIDs are converted from their string representation (as shown by the
10235 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
10236 @code{uuid} form expects 16-byte UUIDs as defined in
10237 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
10238 form of UUID used by the ext2 family of file systems and others, but it
10239 is different from ``UUIDs'' found in FAT file systems, for instance.},
10244 (mount-point "/home")
10246 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
10249 When the source of a file system is a mapped device (@pxref{Mapped
10250 Devices}), its @code{device} field @emph{must} refer to the mapped
10251 device name---e.g., @file{"/dev/mapper/root-partition"}.
10252 This is required so that
10253 the system knows that mounting the file system depends on having the
10254 corresponding device mapping established.
10256 @item @code{flags} (default: @code{'()})
10257 This is a list of symbols denoting mount flags. Recognized flags
10258 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
10259 access to special files), @code{no-suid} (ignore setuid and setgid
10260 bits), and @code{no-exec} (disallow program execution.)
10262 @item @code{options} (default: @code{#f})
10263 This is either @code{#f}, or a string denoting mount options.
10265 @item @code{mount?} (default: @code{#t})
10266 This value indicates whether to automatically mount the file system when
10267 the system is brought up. When set to @code{#f}, the file system gets
10268 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
10269 is not automatically mounted.
10271 @item @code{needed-for-boot?} (default: @code{#f})
10272 This Boolean value indicates whether the file system is needed when
10273 booting. If that is true, then the file system is mounted when the
10274 initial RAM disk (initrd) is loaded. This is always the case, for
10275 instance, for the root file system.
10277 @item @code{check?} (default: @code{#t})
10278 This Boolean indicates whether the file system needs to be checked for
10279 errors before being mounted.
10281 @item @code{create-mount-point?} (default: @code{#f})
10282 When true, the mount point is created if it does not exist yet.
10284 @item @code{dependencies} (default: @code{'()})
10285 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
10286 representing file systems that must be mounted or mapped devices that
10287 must be opened before (and unmounted or closed after) this one.
10289 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
10290 a dependency of @file{/sys/fs/cgroup/cpu} and
10291 @file{/sys/fs/cgroup/memory}.
10293 Another example is a file system that depends on a mapped device, for
10294 example for an encrypted partition (@pxref{Mapped Devices}).
10298 The @code{(gnu system file-systems)} exports the following useful
10301 @defvr {Scheme Variable} %base-file-systems
10302 These are essential file systems that are required on normal systems,
10303 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
10304 below.) Operating system declarations should always contain at least
10308 @defvr {Scheme Variable} %pseudo-terminal-file-system
10309 This is the file system to be mounted as @file{/dev/pts}. It supports
10310 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
10311 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
10312 Manual}). Pseudo-terminals are used by terminal emulators such as
10316 @defvr {Scheme Variable} %shared-memory-file-system
10317 This file system is mounted as @file{/dev/shm} and is used to support
10318 memory sharing across processes (@pxref{Memory-mapped I/O,
10319 @code{shm_open},, libc, The GNU C Library Reference Manual}).
10322 @defvr {Scheme Variable} %immutable-store
10323 This file system performs a read-only ``bind mount'' of
10324 @file{/gnu/store}, making it read-only for all the users including
10325 @code{root}. This prevents against accidental modification by software
10326 running as @code{root} or by system administrators.
10328 The daemon itself is still able to write to the store: it remounts it
10329 read-write in its own ``name space.''
10332 @defvr {Scheme Variable} %binary-format-file-system
10333 The @code{binfmt_misc} file system, which allows handling of arbitrary
10334 executable file types to be delegated to user space. This requires the
10335 @code{binfmt.ko} kernel module to be loaded.
10338 @defvr {Scheme Variable} %fuse-control-file-system
10339 The @code{fusectl} file system, which allows unprivileged users to mount
10340 and unmount user-space FUSE file systems. This requires the
10341 @code{fuse.ko} kernel module to be loaded.
10344 @node Mapped Devices
10345 @section Mapped Devices
10347 @cindex device mapping
10348 @cindex mapped devices
10349 The Linux kernel has a notion of @dfn{device mapping}: a block device,
10350 such as a hard disk partition, can be @dfn{mapped} into another device,
10351 usually in @code{/dev/mapper/},
10352 with additional processing over the data that flows through
10353 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
10354 concept of a ``mapped device'' and that of a file system: both boil down
10355 to @emph{translating} input/output operations made on a file to
10356 operations on its backing store. Thus, the Hurd implements mapped
10357 devices, like file systems, using the generic @dfn{translator} mechanism
10358 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
10359 typical example is encryption device mapping: all writes to the mapped
10360 device are encrypted, and all reads are deciphered, transparently.
10361 Guix extends this notion by considering any device or set of devices that
10362 are @dfn{transformed} in some way to create a new device; for instance,
10363 RAID devices are obtained by @dfn{assembling} several other devices, such
10364 as hard disks or partitions, into a new one that behaves as one partition.
10365 Other examples, not yet implemented, are LVM logical volumes.
10367 Mapped devices are declared using the @code{mapped-device} form,
10368 defined as follows; for examples, see below.
10370 @deftp {Data Type} mapped-device
10371 Objects of this type represent device mappings that will be made when
10372 the system boots up.
10376 This is either a string specifying the name of the block device to be mapped,
10377 such as @code{"/dev/sda3"}, or a list of such strings when several devices
10378 need to be assembled for creating a new one.
10381 This string specifies the name of the resulting mapped device. For
10382 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
10383 specifying @code{"my-partition"} leads to the creation of
10384 the @code{"/dev/mapper/my-partition"} device.
10385 For RAID devices of type @code{raid-device-mapping}, the full device name
10386 such as @code{"/dev/md0"} needs to be given.
10389 This must be a @code{mapped-device-kind} object, which specifies how
10390 @var{source} is mapped to @var{target}.
10394 @defvr {Scheme Variable} luks-device-mapping
10395 This defines LUKS block device encryption using the @command{cryptsetup}
10396 command from the package with the same name. It relies on the
10397 @code{dm-crypt} Linux kernel module.
10400 @defvr {Scheme Variable} raid-device-mapping
10401 This defines a RAID device, which is assembled using the @code{mdadm}
10402 command from the package with the same name. It requires a Linux kernel
10403 module for the appropriate RAID level to be loaded, such as @code{raid456}
10404 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
10407 @cindex disk encryption
10409 The following example specifies a mapping from @file{/dev/sda3} to
10410 @file{/dev/mapper/home} using LUKS---the
10411 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
10412 standard mechanism for disk encryption.
10413 The @file{/dev/mapper/home}
10414 device can then be used as the @code{device} of a @code{file-system}
10415 declaration (@pxref{File Systems}).
10419 (source "/dev/sda3")
10421 (type luks-device-mapping))
10424 Alternatively, to become independent of device numbering, one may obtain
10425 the LUKS UUID (@dfn{unique identifier}) of the source device by a
10429 cryptsetup luksUUID /dev/sda3
10432 and use it as follows:
10436 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
10438 (type luks-device-mapping))
10441 @cindex swap encryption
10442 It is also desirable to encrypt swap space, since swap space may contain
10443 sensitive data. One way to accomplish that is to use a swap file in a
10444 file system on a device mapped via LUKS encryption. In this way, the
10445 swap file is encrypted because the entire device is encrypted.
10446 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
10448 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
10449 may be declared as follows:
10453 (source (list "/dev/sda1" "/dev/sdb1"))
10454 (target "/dev/md0")
10455 (type raid-device-mapping))
10458 The @file{/dev/md0} device can then be used as the @code{device} of a
10459 @code{file-system} declaration (@pxref{File Systems}).
10460 Note that the RAID level need not be given; it is chosen during the
10461 initial creation and formatting of the RAID device and is determined
10462 automatically later.
10465 @node User Accounts
10466 @section User Accounts
10470 @cindex user accounts
10471 User accounts and groups are entirely managed through the
10472 @code{operating-system} declaration. They are specified with the
10473 @code{user-account} and @code{user-group} forms:
10479 (supplementary-groups '("wheel" ;allow use of sudo, etc.
10480 "audio" ;sound card
10481 "video" ;video devices such as webcams
10482 "cdrom")) ;the good ol' CD-ROM
10483 (comment "Bob's sister")
10484 (home-directory "/home/alice"))
10487 When booting or upon completion of @command{guix system reconfigure},
10488 the system ensures that only the user accounts and groups specified in
10489 the @code{operating-system} declaration exist, and with the specified
10490 properties. Thus, account or group creations or modifications made by
10491 directly invoking commands such as @command{useradd} are lost upon
10492 reconfiguration or reboot. This ensures that the system remains exactly
10495 @deftp {Data Type} user-account
10496 Objects of this type represent user accounts. The following members may
10501 The name of the user account.
10505 This is the name (a string) or identifier (a number) of the user group
10506 this account belongs to.
10508 @item @code{supplementary-groups} (default: @code{'()})
10509 Optionally, this can be defined as a list of group names that this
10510 account belongs to.
10512 @item @code{uid} (default: @code{#f})
10513 This is the user ID for this account (a number), or @code{#f}. In the
10514 latter case, a number is automatically chosen by the system when the
10515 account is created.
10517 @item @code{comment} (default: @code{""})
10518 A comment about the account, such as the account owner's full name.
10520 @item @code{home-directory}
10521 This is the name of the home directory for the account.
10523 @item @code{create-home-directory?} (default: @code{#t})
10524 Indicates whether the home directory of this account should be created
10525 if it does not exist yet.
10527 @item @code{shell} (default: Bash)
10528 This is a G-expression denoting the file name of a program to be used as
10529 the shell (@pxref{G-Expressions}).
10531 @item @code{system?} (default: @code{#f})
10532 This Boolean value indicates whether the account is a ``system''
10533 account. System accounts are sometimes treated specially; for instance,
10534 graphical login managers do not list them.
10536 @anchor{user-account-password}
10537 @item @code{password} (default: @code{#f})
10538 You would normally leave this field to @code{#f}, initialize user
10539 passwords as @code{root} with the @command{passwd} command, and then let
10540 users change it with @command{passwd}. Passwords set with
10541 @command{passwd} are of course preserved across reboot and
10544 If you @emph{do} want to have a preset password for an account, then
10545 this field must contain the encrypted password, as a string.
10546 @xref{crypt,,, libc, The GNU C Library Reference Manual}, for more information
10547 on password encryption, and @ref{Encryption,,, guile, GNU Guile Reference
10548 Manual}, for information on Guile's @code{crypt} procedure.
10554 User group declarations are even simpler:
10557 (user-group (name "students"))
10560 @deftp {Data Type} user-group
10561 This type is for, well, user groups. There are just a few fields:
10565 The name of the group.
10567 @item @code{id} (default: @code{#f})
10568 The group identifier (a number). If @code{#f}, a new number is
10569 automatically allocated when the group is created.
10571 @item @code{system?} (default: @code{#f})
10572 This Boolean value indicates whether the group is a ``system'' group.
10573 System groups have low numerical IDs.
10575 @item @code{password} (default: @code{#f})
10576 What, user groups can have a password? Well, apparently yes. Unless
10577 @code{#f}, this field specifies the password of the group.
10582 For convenience, a variable lists all the basic user groups one may
10585 @defvr {Scheme Variable} %base-groups
10586 This is the list of basic user groups that users and/or packages expect
10587 to be present on the system. This includes groups such as ``root'',
10588 ``wheel'', and ``users'', as well as groups used to control access to
10589 specific devices such as ``audio'', ``disk'', and ``cdrom''.
10592 @defvr {Scheme Variable} %base-user-accounts
10593 This is the list of basic system accounts that programs may expect to
10594 find on a GNU/Linux system, such as the ``nobody'' account.
10596 Note that the ``root'' account is not included here. It is a
10597 special-case and is automatically added whether or not it is specified.
10604 A @dfn{locale} defines cultural conventions for a particular language
10605 and region of the world (@pxref{Locales,,, libc, The GNU C Library
10606 Reference Manual}). Each locale has a name that typically has the form
10607 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
10608 @code{fr_LU.utf8} designates the locale for the French language, with
10609 cultural conventions from Luxembourg, and using the UTF-8 encoding.
10611 @cindex locale definition
10612 Usually, you will want to specify the default locale for the machine
10613 using the @code{locale} field of the @code{operating-system} declaration
10614 (@pxref{operating-system Reference, @code{locale}}).
10616 The selected locale is automatically added to the @dfn{locale
10617 definitions} known to the system if needed, with its codeset inferred
10618 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
10619 @code{UTF-8} codeset. Additional locale definitions can be specified in
10620 the @code{locale-definitions} slot of @code{operating-system}---this is
10621 useful, for instance, if the codeset could not be inferred from the
10622 locale name. The default set of locale definitions includes some widely
10623 used locales, but not all the available locales, in order to save space.
10625 For instance, to add the North Frisian locale for Germany, the value of
10629 (cons (locale-definition
10630 (name "fy_DE.utf8") (source "fy_DE"))
10631 %default-locale-definitions)
10634 Likewise, to save space, one might want @code{locale-definitions} to
10635 list only the locales that are actually used, as in:
10638 (list (locale-definition
10639 (name "ja_JP.eucjp") (source "ja_JP")
10640 (charset "EUC-JP")))
10644 The compiled locale definitions are available at
10645 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
10646 version, which is the default location where the GNU@tie{}libc provided
10647 by Guix looks for locale data. This can be overridden using the
10648 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
10649 @code{LOCPATH} and locale packages}).
10651 The @code{locale-definition} form is provided by the @code{(gnu system
10652 locale)} module. Details are given below.
10654 @deftp {Data Type} locale-definition
10655 This is the data type of a locale definition.
10660 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
10661 Reference Manual}, for more information on locale names.
10663 @item @code{source}
10664 The name of the source for that locale. This is typically the
10665 @code{@var{language}_@var{territory}} part of the locale name.
10667 @item @code{charset} (default: @code{"UTF-8"})
10668 The ``character set'' or ``code set'' for that locale,
10669 @uref{http://www.iana.org/assignments/character-sets, as defined by
10675 @defvr {Scheme Variable} %default-locale-definitions
10676 A list of commonly used UTF-8 locales, used as the default
10677 value of the @code{locale-definitions} field of @code{operating-system}
10680 @cindex locale name
10681 @cindex normalized codeset in locale names
10682 These locale definitions use the @dfn{normalized codeset} for the part
10683 that follows the dot in the name (@pxref{Using gettextized software,
10684 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
10685 instance it has @code{uk_UA.utf8} but @emph{not}, say,
10686 @code{uk_UA.UTF-8}.
10689 @subsection Locale Data Compatibility Considerations
10691 @cindex incompatibility, of locale data
10692 @code{operating-system} declarations provide a @code{locale-libcs} field
10693 to specify the GNU@tie{}libc packages that are used to compile locale
10694 declarations (@pxref{operating-system Reference}). ``Why would I
10695 care?'', you may ask. Well, it turns out that the binary format of
10696 locale data is occasionally incompatible from one libc version to
10699 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
10700 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
10701 For instance, a program linked against libc version 2.21 is unable to
10702 read locale data produced with libc 2.22; worse, that program
10703 @emph{aborts} instead of simply ignoring the incompatible locale
10704 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
10705 the incompatible locale data, which is already an improvement.}.
10706 Similarly, a program linked against libc 2.22 can read most, but not
10707 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
10708 data is incompatible); thus calls to @code{setlocale} may fail, but
10709 programs will not abort.
10711 The ``problem'' in GuixSD is that users have a lot of freedom: They can
10712 choose whether and when to upgrade software in their profiles, and might
10713 be using a libc version different from the one the system administrator
10714 used to build the system-wide locale data.
10716 Fortunately, unprivileged users can also install their own locale data
10717 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
10718 @code{GUIX_LOCPATH} and locale packages}).
10720 Still, it is best if the system-wide locale data at
10721 @file{/run/current-system/locale} is built for all the libc versions
10722 actually in use on the system, so that all the programs can access
10723 it---this is especially crucial on a multi-user system. To do that, the
10724 administrator can specify several libc packages in the
10725 @code{locale-libcs} field of @code{operating-system}:
10728 (use-package-modules base)
10732 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
10735 This example would lead to a system containing locale definitions for
10736 both libc 2.21 and the current version of libc in
10737 @file{/run/current-system/locale}.
10743 @cindex system services
10744 An important part of preparing an @code{operating-system} declaration is
10745 listing @dfn{system services} and their configuration (@pxref{Using the
10746 Configuration System}). System services are typically daemons launched
10747 when the system boots, or other actions needed at that time---e.g.,
10748 configuring network access.
10750 GuixSD has a broad definition of ``service'' (@pxref{Service
10751 Composition}), but many services are managed by the GNU@tie{}Shepherd
10752 (@pxref{Shepherd Services}). On a running system, the @command{herd}
10753 command allows you to list the available services, show their status,
10754 start and stop them, or do other specific operations (@pxref{Jump
10755 Start,,, shepherd, The GNU Shepherd Manual}). For example:
10761 The above command, run as @code{root}, lists the currently defined
10762 services. The @command{herd doc} command shows a synopsis of the given
10763 service and its associated actions:
10767 Run libc's name service cache daemon (nscd).
10769 # herd doc nscd action invalidate
10770 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
10773 The @command{start}, @command{stop}, and @command{restart} sub-commands
10774 have the effect you would expect. For instance, the commands below stop
10775 the nscd service and restart the Xorg display server:
10779 Service nscd has been stopped.
10780 # herd restart xorg-server
10781 Service xorg-server has been stopped.
10782 Service xorg-server has been started.
10785 The following sections document the available services, starting with
10786 the core services, that may be used in an @code{operating-system}
10790 * Base Services:: Essential system services.
10791 * Scheduled Job Execution:: The mcron service.
10792 * Log Rotation:: The rottlog service.
10793 * Networking Services:: Network setup, SSH daemon, etc.
10794 * X Window:: Graphical display.
10795 * Printing Services:: Local and remote printer support.
10796 * Desktop Services:: D-Bus and desktop services.
10797 * Sound Services:: ALSA and Pulseaudio services.
10798 * Database Services:: SQL databases, key-value stores, etc.
10799 * Mail Services:: IMAP, POP3, SMTP, and all that.
10800 * Messaging Services:: Messaging services.
10801 * Telephony Services:: Telephony services.
10802 * Monitoring Services:: Monitoring services.
10803 * Kerberos Services:: Kerberos services.
10804 * Web Services:: Web servers.
10805 * Certificate Services:: TLS certificates via Let's Encrypt.
10806 * DNS Services:: DNS daemons.
10807 * VPN Services:: VPN daemons.
10808 * Network File System:: NFS related services.
10809 * Continuous Integration:: The Cuirass service.
10810 * Power Management Services:: Extending battery life.
10811 * Audio Services:: The MPD.
10812 * Virtualization Services:: Virtualization services.
10813 * Version Control Services:: Providing remote access to Git repositories.
10814 * Game Services:: Game servers.
10815 * Miscellaneous Services:: Other services.
10818 @node Base Services
10819 @subsection Base Services
10821 The @code{(gnu services base)} module provides definitions for the basic
10822 services that one expects from the system. The services exported by
10823 this module are listed below.
10825 @defvr {Scheme Variable} %base-services
10826 This variable contains a list of basic services (@pxref{Service Types
10827 and Services}, for more information on service objects) one would
10828 expect from the system: a login service (mingetty) on each tty, syslogd,
10829 the libc name service cache daemon (nscd), the udev device manager, and
10832 This is the default value of the @code{services} field of
10833 @code{operating-system} declarations. Usually, when customizing a
10834 system, you will want to append services to @var{%base-services}, like
10838 (cons* (service avahi-service-type)
10839 (service openssh-service-type)
10844 @defvr {Scheme Variable} special-files-service-type
10845 This is the service that sets up ``special files'' such as
10846 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
10848 The value associated with @code{special-files-service-type} services
10849 must be a list of tuples where the first element is the ``special file''
10850 and the second element is its target. By default it is:
10852 @cindex @file{/bin/sh}
10853 @cindex @file{sh}, in @file{/bin}
10855 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
10858 @cindex @file{/usr/bin/env}
10859 @cindex @file{env}, in @file{/usr/bin}
10860 If you want to add, say, @code{/usr/bin/env} to your system, you can
10864 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
10865 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
10868 Since this is part of @code{%base-services}, you can use
10869 @code{modify-services} to customize the set of special files
10870 (@pxref{Service Reference, @code{modify-services}}). But the simple way
10871 to add a special file is @i{via} the @code{extra-special-file} procedure
10875 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
10876 Use @var{target} as the ``special file'' @var{file}.
10878 For example, adding the following lines to the @code{services} field of
10879 your operating system declaration leads to a @file{/usr/bin/env}
10883 (extra-special-file "/usr/bin/env"
10884 (file-append coreutils "/bin/env"))
10888 @deffn {Scheme Procedure} host-name-service @var{name}
10889 Return a service that sets the host name to @var{name}.
10892 @deffn {Scheme Procedure} login-service @var{config}
10893 Return a service to run login according to @var{config}, a
10894 @code{<login-configuration>} object, which specifies the message of the day,
10895 among other things.
10898 @deftp {Data Type} login-configuration
10899 This is the data type representing the configuration of login.
10904 @cindex message of the day
10905 A file-like object containing the ``message of the day''.
10907 @item @code{allow-empty-passwords?} (default: @code{#t})
10908 Allow empty passwords by default so that first-time users can log in when
10909 the 'root' account has just been created.
10914 @deffn {Scheme Procedure} mingetty-service @var{config}
10915 Return a service to run mingetty according to @var{config}, a
10916 @code{<mingetty-configuration>} object, which specifies the tty to run, among
10920 @deftp {Data Type} mingetty-configuration
10921 This is the data type representing the configuration of Mingetty, which
10922 provides the default implementation of virtual console log-in.
10927 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
10929 @item @code{auto-login} (default: @code{#f})
10930 When true, this field must be a string denoting the user name under
10931 which the system automatically logs in. When it is @code{#f}, a
10932 user name and password must be entered to log in.
10934 @item @code{login-program} (default: @code{#f})
10935 This must be either @code{#f}, in which case the default log-in program
10936 is used (@command{login} from the Shadow tool suite), or a gexp denoting
10937 the name of the log-in program.
10939 @item @code{login-pause?} (default: @code{#f})
10940 When set to @code{#t} in conjunction with @var{auto-login}, the user
10941 will have to press a key before the log-in shell is launched.
10943 @item @code{mingetty} (default: @var{mingetty})
10944 The Mingetty package to use.
10949 @deffn {Scheme Procedure} agetty-service @var{config}
10950 Return a service to run agetty according to @var{config}, an
10951 @code{<agetty-configuration>} object, which specifies the tty to run,
10952 among other things.
10955 @deftp {Data Type} agetty-configuration
10956 This is the data type representing the configuration of agetty, which
10957 implements virtual and serial console log-in. See the @code{agetty(8)}
10958 man page for more information.
10963 The name of the console this agetty runs on, as a string---e.g.,
10964 @code{"ttyS0"}. This argument is optional, it will default to
10965 a reasonable default serial port used by the kernel Linux.
10967 For this, if there is a value for an option @code{agetty.tty} in the kernel
10968 command line, agetty will extract the device name of the serial port
10969 from it and use that.
10971 If not and if there is a value for an option @code{console} with a tty in
10972 the Linux command line, agetty will extract the device name of the
10973 serial port from it and use that.
10975 In both cases, agetty will leave the other serial device settings
10976 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
10979 @item @code{baud-rate} (default: @code{#f})
10980 A string containing a comma-separated list of one or more baud rates, in
10983 @item @code{term} (default: @code{#f})
10984 A string containing the value used for the @code{TERM} environment
10987 @item @code{eight-bits?} (default: @code{#f})
10988 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
10991 @item @code{auto-login} (default: @code{#f})
10992 When passed a login name, as a string, the specified user will be logged
10993 in automatically without prompting for their login name or password.
10995 @item @code{no-reset?} (default: @code{#f})
10996 When @code{#t}, don't reset terminal cflags (control modes).
10998 @item @code{host} (default: @code{#f})
10999 This accepts a string containing the "login_host", which will be written
11000 into the @file{/var/run/utmpx} file.
11002 @item @code{remote?} (default: @code{#f})
11003 When set to @code{#t} in conjunction with @var{host}, this will add an
11004 @code{-r} fakehost option to the command line of the login program
11005 specified in @var{login-program}.
11007 @item @code{flow-control?} (default: @code{#f})
11008 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
11010 @item @code{no-issue?} (default: @code{#f})
11011 When set to @code{#t}, the contents of the @file{/etc/issue} file will
11012 not be displayed before presenting the login prompt.
11014 @item @code{init-string} (default: @code{#f})
11015 This accepts a string that will be sent to the tty or modem before
11016 sending anything else. It can be used to initialize a modem.
11018 @item @code{no-clear?} (default: @code{#f})
11019 When set to @code{#t}, agetty will not clear the screen before showing
11022 @item @code{login-program} (default: (file-append shadow "/bin/login"))
11023 This must be either a gexp denoting the name of a log-in program, or
11024 unset, in which case the default value is the @command{login} from the
11027 @item @code{local-line} (default: @code{#f})
11028 Control the CLOCAL line flag. This accepts one of three symbols as
11029 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
11030 the default value chosen by agetty is @code{'auto}.
11032 @item @code{extract-baud?} (default: @code{#f})
11033 When set to @code{#t}, instruct agetty to try to extract the baud rate
11034 from the status messages produced by certain types of modems.
11036 @item @code{skip-login?} (default: @code{#f})
11037 When set to @code{#t}, do not prompt the user for a login name. This
11038 can be used with @var{login-program} field to use non-standard login
11041 @item @code{no-newline?} (default: @code{#f})
11042 When set to @code{#t}, do not print a newline before printing the
11043 @file{/etc/issue} file.
11045 @c Is this dangerous only when used with login-program, or always?
11046 @item @code{login-options} (default: @code{#f})
11047 This option accepts a string containing options that are passed to the
11048 login program. When used with the @var{login-program}, be aware that a
11049 malicious user could try to enter a login name containing embedded
11050 options that could be parsed by the login program.
11052 @item @code{login-pause} (default: @code{#f})
11053 When set to @code{#t}, wait for any key before showing the login prompt.
11054 This can be used in conjunction with @var{auto-login} to save memory by
11055 lazily spawning shells.
11057 @item @code{chroot} (default: @code{#f})
11058 Change root to the specified directory. This option accepts a directory
11061 @item @code{hangup?} (default: @code{#f})
11062 Use the Linux system call @code{vhangup} to do a virtual hangup of the
11063 specified terminal.
11065 @item @code{keep-baud?} (default: @code{#f})
11066 When set to @code{#t}, try to keep the existing baud rate. The baud
11067 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
11070 @item @code{timeout} (default: @code{#f})
11071 When set to an integer value, terminate if no user name could be read
11072 within @var{timeout} seconds.
11074 @item @code{detect-case?} (default: @code{#f})
11075 When set to @code{#t}, turn on support for detecting an uppercase-only
11076 terminal. This setting will detect a login name containing only
11077 uppercase letters as indicating an uppercase-only terminal and turn on
11078 some upper-to-lower case conversions. Note that this will not support
11079 Unicode characters.
11081 @item @code{wait-cr?} (default: @code{#f})
11082 When set to @code{#t}, wait for the user or modem to send a
11083 carriage-return or linefeed character before displaying
11084 @file{/etc/issue} or login prompt. This is typically used with the
11085 @var{init-string} option.
11087 @item @code{no-hints?} (default: @code{#f})
11088 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
11091 @item @code{no-hostname?} (default: @code{#f})
11092 By default, the hostname is printed. When this option is set to
11093 @code{#t}, no hostname will be shown at all.
11095 @item @code{long-hostname?} (default: @code{#f})
11096 By default, the hostname is only printed until the first dot. When this
11097 option is set to @code{#t}, the fully qualified hostname by
11098 @code{gethostname} or @code{getaddrinfo} is shown.
11100 @item @code{erase-characters} (default: @code{#f})
11101 This option accepts a string of additional characters that should be
11102 interpreted as backspace when the user types their login name.
11104 @item @code{kill-characters} (default: @code{#f})
11105 This option accepts a string that should be interpreted to mean "ignore
11106 all previous characters" (also called a "kill" character) when the types
11109 @item @code{chdir} (default: @code{#f})
11110 This option accepts, as a string, a directory path that will be changed
11113 @item @code{delay} (default: @code{#f})
11114 This options accepts, as an integer, the number of seconds to sleep
11115 before opening the tty and displaying the login prompt.
11117 @item @code{nice} (default: @code{#f})
11118 This option accepts, as an integer, the nice value with which to run the
11119 @command{login} program.
11121 @item @code{extra-options} (default: @code{'()})
11122 This option provides an "escape hatch" for the user to provide arbitrary
11123 command-line arguments to @command{agetty} as a list of strings.
11128 @deffn {Scheme Procedure} kmscon-service-type @var{config}
11129 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
11130 according to @var{config}, a @code{<kmscon-configuration>} object, which
11131 specifies the tty to run, among other things.
11134 @deftp {Data Type} kmscon-configuration
11135 This is the data type representing the configuration of Kmscon, which
11136 implements virtual console log-in.
11140 @item @code{virtual-terminal}
11141 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
11143 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
11144 A gexp denoting the name of the log-in program. The default log-in program is
11145 @command{login} from the Shadow tool suite.
11147 @item @code{login-arguments} (default: @code{'("-p")})
11148 A list of arguments to pass to @command{login}.
11150 @item @code{auto-login} (default: @code{#f})
11151 When passed a login name, as a string, the specified user will be logged
11152 in automatically without prompting for their login name or password.
11154 @item @code{hardware-acceleration?} (default: #f)
11155 Whether to use hardware acceleration.
11157 @item @code{kmscon} (default: @var{kmscon})
11158 The Kmscon package to use.
11163 @cindex name service cache daemon
11165 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
11166 [#:name-services '()]
11167 Return a service that runs the libc name service cache daemon (nscd) with the
11168 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
11169 Service Switch}, for an example.
11171 For convenience, the Shepherd service for nscd provides the following actions:
11175 @cindex cache invalidation, nscd
11176 @cindex nscd, cache invalidation
11177 This invalidate the given cache. For instance, running:
11180 herd invalidate nscd hosts
11184 invalidates the host name lookup cache of nscd.
11187 Running @command{herd statistics nscd} displays information about nscd usage
11193 @defvr {Scheme Variable} %nscd-default-configuration
11194 This is the default @code{<nscd-configuration>} value (see below) used
11195 by @code{nscd-service}. It uses the caches defined by
11196 @var{%nscd-default-caches}; see below.
11199 @deftp {Data Type} nscd-configuration
11200 This is the data type representing the name service cache daemon (nscd)
11205 @item @code{name-services} (default: @code{'()})
11206 List of packages denoting @dfn{name services} that must be visible to
11207 the nscd---e.g., @code{(list @var{nss-mdns})}.
11209 @item @code{glibc} (default: @var{glibc})
11210 Package object denoting the GNU C Library providing the @command{nscd}
11213 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
11214 Name of the nscd log file. This is where debugging output goes when
11215 @code{debug-level} is strictly positive.
11217 @item @code{debug-level} (default: @code{0})
11218 Integer denoting the debugging levels. Higher numbers mean that more
11219 debugging output is logged.
11221 @item @code{caches} (default: @var{%nscd-default-caches})
11222 List of @code{<nscd-cache>} objects denoting things to be cached; see
11228 @deftp {Data Type} nscd-cache
11229 Data type representing a cache database of nscd and its parameters.
11233 @item @code{database}
11234 This is a symbol representing the name of the database to be cached.
11235 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
11236 @code{services}, which designate the corresponding NSS database
11237 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
11239 @item @code{positive-time-to-live}
11240 @itemx @code{negative-time-to-live} (default: @code{20})
11241 A number representing the number of seconds during which a positive or
11242 negative lookup result remains in cache.
11244 @item @code{check-files?} (default: @code{#t})
11245 Whether to check for updates of the files corresponding to
11248 For instance, when @var{database} is @code{hosts}, setting this flag
11249 instructs nscd to check for updates in @file{/etc/hosts} and to take
11252 @item @code{persistent?} (default: @code{#t})
11253 Whether the cache should be stored persistently on disk.
11255 @item @code{shared?} (default: @code{#t})
11256 Whether the cache should be shared among users.
11258 @item @code{max-database-size} (default: 32@tie{}MiB)
11259 Maximum size in bytes of the database cache.
11261 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
11262 @c settings, so leave them out.
11267 @defvr {Scheme Variable} %nscd-default-caches
11268 List of @code{<nscd-cache>} objects used by default by
11269 @code{nscd-configuration} (see above).
11271 It enables persistent and aggressive caching of service and host name
11272 lookups. The latter provides better host name lookup performance,
11273 resilience in the face of unreliable name servers, and also better
11274 privacy---often the result of host name lookups is in local cache, so
11275 external name servers do not even need to be queried.
11278 @anchor{syslog-configuration-type}
11281 @deftp {Data Type} syslog-configuration
11282 This data type represents the configuration of the syslog daemon.
11285 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
11286 The syslog daemon to use.
11288 @item @code{config-file} (default: @code{%default-syslog.conf})
11289 The syslog configuration file to use.
11294 @anchor{syslog-service}
11296 @deffn {Scheme Procedure} syslog-service @var{config}
11297 Return a service that runs a syslog daemon according to @var{config}.
11299 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
11300 information on the configuration file syntax.
11303 @defvr {Scheme Variable} guix-service-type
11304 This is the type of the service that runs the build daemon,
11305 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
11306 @code{guix-configuration} record as described below.
11309 @anchor{guix-configuration-type}
11310 @deftp {Data Type} guix-configuration
11311 This data type represents the configuration of the Guix build daemon.
11312 @xref{Invoking guix-daemon}, for more information.
11315 @item @code{guix} (default: @var{guix})
11316 The Guix package to use.
11318 @item @code{build-group} (default: @code{"guixbuild"})
11319 Name of the group for build user accounts.
11321 @item @code{build-accounts} (default: @code{10})
11322 Number of build user accounts to create.
11324 @item @code{authorize-key?} (default: @code{#t})
11325 @cindex substitutes, authorization thereof
11326 Whether to authorize the substitute keys listed in
11327 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
11328 (@pxref{Substitutes}).
11330 @vindex %default-authorized-guix-keys
11331 @item @code{authorized-keys} (default: @var{%default-authorized-guix-keys})
11332 The list of authorized key files for archive imports, as a list of
11333 string-valued gexps (@pxref{Invoking guix archive}). By default, it
11334 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
11336 @item @code{use-substitutes?} (default: @code{#t})
11337 Whether to use substitutes.
11339 @item @code{substitute-urls} (default: @var{%default-substitute-urls})
11340 The list of URLs where to look for substitutes by default.
11342 @item @code{max-silent-time} (default: @code{0})
11343 @itemx @code{timeout} (default: @code{0})
11344 The number of seconds of silence and the number of seconds of activity,
11345 respectively, after which a build process times out. A value of zero
11346 disables the timeout.
11348 @item @code{log-compression} (default: @code{'bzip2})
11349 The type of compression used for build logs---one of @code{gzip},
11350 @code{bzip2}, or @code{none}.
11352 @item @code{extra-options} (default: @code{'()})
11353 List of extra command-line options for @command{guix-daemon}.
11355 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
11356 File where @command{guix-daemon}'s standard output and standard error
11359 @item @code{http-proxy} (default: @code{#f})
11360 The HTTP proxy used for downloading fixed-output derivations and
11363 @item @code{tmpdir} (default: @code{#f})
11364 A directory path where the @command{guix-daemon} will perform builds.
11369 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
11370 Run @var{udev}, which populates the @file{/dev} directory dynamically.
11371 udev rules can be provided as a list of files through the @var{rules}
11372 variable. The procedures @var{udev-rule} and @var{file->udev-rule} from
11373 @code{(gnu services base)} simplify the creation of such rule files.
11376 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
11377 Return a udev-rule file named @var{file-name} containing the rules
11378 defined by the @var{contents} literal.
11380 In the following example, a rule for a USB device is defined to be
11381 stored in the file @file{90-usb-thing.rules}. The rule runs a script
11382 upon detecting a USB device with a given product identifier.
11385 (define %example-udev-rule
11387 "90-usb-thing.rules"
11388 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
11389 "ATTR@{product@}==\"Example\", "
11390 "RUN+=\"/path/to/script\"")))
11393 The @command{herd rules udev} command, as root, returns the name of the
11394 directory containing all the active udev rules.
11397 Here we show how the default @var{udev-service} can be extended with it.
11403 (modify-services %desktop-services
11404 (udev-service-type config =>
11405 (udev-configuration (inherit config)
11406 (rules (append (udev-configuration-rules config)
11407 (list %example-udev-rule))))))))
11410 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
11411 Return a udev file named @var{file-name} containing the rules defined
11412 within @var{file}, a file-like object.
11414 The following example showcases how we can use an existing rule file.
11417 (use-modules (guix download) ;for url-fetch
11418 (guix packages) ;for origin
11421 (define %android-udev-rules
11423 "51-android-udev.rules"
11424 (let ((version "20170910"))
11427 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
11428 "android-udev-rules/" version "/51-android.rules"))
11430 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
11434 Additionally, Guix package definitions can be included in @var{rules} in
11435 order to extend the udev rules with the definitions found under their
11436 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
11437 @var{file->udev-rule} example, we could have used the
11438 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
11439 packages android)} module.
11441 The following example shows how to use the @var{android-udev-rules}
11442 package so that the Android tool @command{adb} can detect devices
11443 without root privileges. It also details how to create the
11444 @code{adbusers} group, which is required for the proper functioning of
11445 the rules defined within the @var{android-udev-rules} package. To
11446 create such a group, we must define it both as part of the
11447 @var{supplementary-groups} of our @var{user-account} declaration, as
11448 well as in the @var{groups} field of the @var{operating-system} record.
11451 (use-modules (gnu packages android) ;for android-udev-rules
11452 (gnu system shadow) ;for user-group
11457 (users (cons (user-acount
11459 (supplementary-groups
11460 '("adbusers" ;for adb
11461 "wheel" "netdev" "audio" "video"))
11464 (groups (cons (user-group (system? #t) (name "adbusers"))
11470 (modify-services %desktop-services
11471 (udev-service-type config =>
11472 (udev-configuration (inherit config)
11473 (rules (cons* android-udev-rules
11474 (udev-configuration-rules config))))))))
11477 @defvr {Scheme Variable} urandom-seed-service-type
11478 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
11479 when rebooting. It also tries to seed @file{/dev/urandom} from
11480 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
11484 @defvr {Scheme Variable} %random-seed-file
11485 This is the name of the file where some random bytes are saved by
11486 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
11487 It defaults to @file{/var/lib/random-seed}.
11492 @deffn {Scheme Procedure} console-keymap-service @var{files} ...
11493 @cindex keyboard layout
11494 Return a service to load console keymaps from @var{files} using
11495 @command{loadkeys} command. Most likely, you want to load some default
11496 keymap, which can be done like this:
11499 (console-keymap-service "dvorak")
11502 Or, for example, for a Swedish keyboard, you may need to combine
11503 the following keymaps:
11505 (console-keymap-service "se-lat6" "se-fi-lat6")
11508 Also you can specify a full file name (or file names) of your keymap(s).
11509 See @code{man loadkeys} for details.
11515 @defvr {Scheme Variable} gpm-service-type
11516 This is the type of the service that runs GPM, the @dfn{general-purpose
11517 mouse daemon}, which provides mouse support to the Linux console. GPM
11518 allows users to use the mouse in the console, notably to select, copy,
11521 The value for services of this type must be a @code{gpm-configuration}
11522 (see below). This service is not part of @var{%base-services}.
11525 @deftp {Data Type} gpm-configuration
11526 Data type representing the configuration of GPM.
11529 @item @code{options} (default: @code{%default-gpm-options})
11530 Command-line options passed to @command{gpm}. The default set of
11531 options instruct @command{gpm} to listen to mouse events on
11532 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
11535 @item @code{gpm} (default: @code{gpm})
11536 The GPM package to use.
11541 @anchor{guix-publish-service-type}
11542 @deffn {Scheme Variable} guix-publish-service-type
11543 This is the service type for @command{guix publish} (@pxref{Invoking
11544 guix publish}). Its value must be a @code{guix-configuration}
11545 object, as described below.
11547 This assumes that @file{/etc/guix} already contains a signing key pair as
11548 created by @command{guix archive --generate-key} (@pxref{Invoking guix
11549 archive}). If that is not the case, the service will fail to start.
11552 @deftp {Data Type} guix-publish-configuration
11553 Data type representing the configuration of the @code{guix publish}
11557 @item @code{guix} (default: @code{guix})
11558 The Guix package to use.
11560 @item @code{port} (default: @code{80})
11561 The TCP port to listen for connections.
11563 @item @code{host} (default: @code{"localhost"})
11564 The host (and thus, network interface) to listen to. Use
11565 @code{"0.0.0.0"} to listen on all the network interfaces.
11567 @item @code{compression-level} (default: @code{3})
11568 The gzip compression level at which substitutes are compressed. Use
11569 @code{0} to disable compression altogether, and @code{9} to get the best
11570 compression ratio at the expense of increased CPU usage.
11572 @item @code{nar-path} (default: @code{"nar"})
11573 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
11574 publish, @code{--nar-path}}, for details.
11576 @item @code{cache} (default: @code{#f})
11577 When it is @code{#f}, disable caching and instead generate archives on
11578 demand. Otherwise, this should be the name of a directory---e.g.,
11579 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
11580 archives and meta-data ready to be sent. @xref{Invoking guix publish,
11581 @option{--cache}}, for more information on the tradeoffs involved.
11583 @item @code{workers} (default: @code{#f})
11584 When it is an integer, this is the number of worker threads used for
11585 caching; when @code{#f}, the number of processors is used.
11586 @xref{Invoking guix publish, @option{--workers}}, for more information.
11588 @item @code{ttl} (default: @code{#f})
11589 When it is an integer, this denotes the @dfn{time-to-live} in seconds
11590 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
11591 for more information.
11595 @anchor{rngd-service}
11596 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
11597 [#:device "/dev/hwrng"]
11598 Return a service that runs the @command{rngd} program from @var{rng-tools}
11599 to add @var{device} to the kernel's entropy pool. The service will fail if
11600 @var{device} does not exist.
11603 @anchor{pam-limits-service}
11604 @cindex session limits
11609 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
11611 Return a service that installs a configuration file for the
11612 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
11613 @code{pam_limits} module}. The procedure optionally takes a list of
11614 @code{pam-limits-entry} values, which can be used to specify
11615 @code{ulimit} limits and nice priority limits to user sessions.
11617 The following limits definition sets two hard and soft limits for all
11618 login sessions of users in the @code{realtime} group:
11621 (pam-limits-service
11623 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
11624 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
11627 The first entry increases the maximum realtime priority for
11628 non-privileged processes; the second entry lifts any restriction of the
11629 maximum address space that can be locked in memory. These settings are
11630 commonly used for real-time audio systems.
11633 @node Scheduled Job Execution
11634 @subsection Scheduled Job Execution
11638 @cindex scheduling jobs
11639 The @code{(gnu services mcron)} module provides an interface to
11640 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
11641 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
11642 Unix @command{cron} daemon; the main difference is that it is
11643 implemented in Guile Scheme, which provides a lot of flexibility when
11644 specifying the scheduling of jobs and their actions.
11646 The example below defines an operating system that runs the
11647 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
11648 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
11649 well as the @command{mkid} command on behalf of an unprivileged user
11650 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
11651 gexps to introduce job definitions that are passed to mcron
11652 (@pxref{G-Expressions}).
11655 (use-modules (guix) (gnu) (gnu services mcron))
11656 (use-package-modules base idutils)
11658 (define updatedb-job
11659 ;; Run 'updatedb' at 3AM every day. Here we write the
11660 ;; job's action as a Scheme procedure.
11661 #~(job '(next-hour '(3))
11663 (execl (string-append #$findutils "/bin/updatedb")
11665 "--prunepaths=/tmp /var/tmp /gnu/store"))))
11667 (define garbage-collector-job
11668 ;; Collect garbage 5 minutes after midnight every day.
11669 ;; The job's action is a shell command.
11670 #~(job "5 0 * * *" ;Vixie cron syntax
11673 (define idutils-job
11674 ;; Update the index database as user "charlie" at 12:15PM
11675 ;; and 19:15PM. This runs from the user's home directory.
11676 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
11677 (string-append #$idutils "/bin/mkid src")
11682 (services (cons (service mcron-service-type
11683 (mcron-configuration
11684 (jobs (list garbage-collector-job
11690 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
11691 for more information on mcron job specifications. Below is the
11692 reference of the mcron service.
11694 On a running system, you can use the @code{schedule} action of the service to
11695 visualize the mcron jobs that will be executed next:
11698 # herd schedule mcron
11702 The example above lists the next five tasks that will be executed, but you can
11703 also specify the number of tasks to display:
11706 # herd schedule mcron 10
11709 @defvr {Scheme Variable} mcron-service-type
11710 This is the type of the @code{mcron} service, whose value is an
11711 @code{mcron-configuration} object.
11713 This service type can be the target of a service extension that provides
11714 it additional job specifications (@pxref{Service Composition}). In
11715 other words, it is possible to define services that provide additional
11719 @deftp {Data Type} mcron-configuration
11720 Data type representing the configuration of mcron.
11723 @item @code{mcron} (default: @var{mcron})
11724 The mcron package to use.
11727 This is a list of gexps (@pxref{G-Expressions}), where each gexp
11728 corresponds to an mcron job specification (@pxref{Syntax, mcron job
11729 specifications,, mcron, GNU@tie{}mcron}).
11735 @subsection Log Rotation
11738 @cindex log rotation
11740 Log files such as those found in @file{/var/log} tend to grow endlessly,
11741 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
11742 their contents in separate files, possibly compressed. The @code{(gnu
11743 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
11744 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
11746 The example below defines an operating system that provides log rotation
11747 with the default settings, for commonly encountered log files.
11750 (use-modules (guix) (gnu))
11751 (use-service-modules admin mcron)
11752 (use-package-modules base idutils)
11756 (services (cons (service rottlog-service-type)
11760 @defvr {Scheme Variable} rottlog-service-type
11761 This is the type of the Rottlog service, whose value is a
11762 @code{rottlog-configuration} object.
11764 Other services can extend this one with new @code{log-rotation} objects
11765 (see below), thereby augmenting the set of files to be rotated.
11767 This service type can define mcron jobs (@pxref{Scheduled Job
11768 Execution}) to run the rottlog service.
11771 @deftp {Data Type} rottlog-configuration
11772 Data type representing the configuration of rottlog.
11775 @item @code{rottlog} (default: @code{rottlog})
11776 The Rottlog package to use.
11778 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
11779 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
11780 rottlog, GNU Rot[t]log Manual}).
11782 @item @code{rotations} (default: @code{%default-rotations})
11783 A list of @code{log-rotation} objects as defined below.
11786 This is a list of gexps where each gexp corresponds to an mcron job
11787 specification (@pxref{Scheduled Job Execution}).
11791 @deftp {Data Type} log-rotation
11792 Data type representing the rotation of a group of log files.
11794 Taking an example from the Rottlog manual (@pxref{Period Related File
11795 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
11801 (files '("/var/log/apache/*"))
11802 (options '("storedir apache-archives"
11808 The list of fields is as follows:
11811 @item @code{frequency} (default: @code{'weekly})
11812 The log rotation frequency, a symbol.
11815 The list of files or file glob patterns to rotate.
11817 @item @code{options} (default: @code{'()})
11818 The list of rottlog options for this rotation (@pxref{Configuration
11819 parameters,,, rottlog, GNU Rot[t]lg Manual}).
11821 @item @code{post-rotate} (default: @code{#f})
11822 Either @code{#f} or a gexp to execute once the rotation has completed.
11826 @defvr {Scheme Variable} %default-rotations
11827 Specifies weekly rotation of @var{%rotated-files} and
11828 a couple of other files.
11831 @defvr {Scheme Variable} %rotated-files
11832 The list of syslog-controlled files to be rotated. By default it is:
11833 @code{'("/var/log/messages" "/var/log/secure")}.
11836 @node Networking Services
11837 @subsection Networking Services
11839 The @code{(gnu services networking)} module provides services to configure
11840 the network interface.
11842 @cindex DHCP, networking service
11843 @defvr {Scheme Variable} dhcp-client-service-type
11844 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
11845 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
11846 is the DHCP client package to use, @code{isc-dhcp} by default.
11849 @deffn {Scheme Procedure} dhcpd-service-type
11850 This type defines a service that runs a DHCP daemon. To create a
11851 service of this type, you must supply a @code{<dhcpd-configuration>}.
11855 (service dhcpd-service-type
11856 (dhcpd-configuration
11857 (config-file (local-file "my-dhcpd.conf"))
11858 (interfaces '("enp0s25"))))
11862 @deftp {Data Type} dhcpd-configuration
11864 @item @code{package} (default: @code{isc-dhcp})
11865 The package that provides the DHCP daemon. This package is expected to
11866 provide the daemon at @file{sbin/dhcpd} relative to its output
11867 directory. The default package is the
11868 @uref{http://www.isc.org/products/DHCP, ISC's DHCP server}.
11869 @item @code{config-file} (default: @code{#f})
11870 The configuration file to use. This is required. It will be passed to
11871 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
11872 object (@pxref{G-Expressions, file-like objects}). See @code{man
11873 dhcpd.conf} for details on the configuration file syntax.
11874 @item @code{version} (default: @code{"4"})
11875 The DHCP version to use. The ISC DHCP server supports the values ``4'',
11876 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
11877 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
11879 @item @code{run-directory} (default: @code{"/run/dhcpd"})
11880 The run directory to use. At service activation time, this directory
11881 will be created if it does not exist.
11882 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
11883 The PID file to use. This corresponds to the @code{-pf} option of
11884 @code{dhcpd}. See @code{man dhcpd} for details.
11885 @item @code{interfaces} (default: @code{'()})
11886 The names of the network interfaces on which dhcpd should listen for
11887 broadcasts. If this list is not empty, then its elements (which must be
11888 strings) will be appended to the @code{dhcpd} invocation when starting
11889 the daemon. It may not be necessary to explicitly specify any
11890 interfaces here; see @code{man dhcpd} for details.
11894 @defvr {Scheme Variable} static-networking-service-type
11895 This is the type for statically-configured network interfaces.
11896 @c TODO Document <static-networking> data structures.
11899 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
11900 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
11901 [#:requirement @code{'(udev)}]
11902 Return a service that starts @var{interface} with address @var{ip}. If
11903 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
11904 it must be a string specifying the default network gateway. @var{requirement}
11905 can be used to declare a dependency on another service before configuring the
11908 This procedure can be called several times, one for each network
11909 interface of interest. Behind the scenes what it does is extend
11910 @code{static-networking-service-type} with additional network interfaces
11916 (static-networking-service "eno1" "192.168.1.82"
11917 #:gateway "192.168.1.2"
11918 #:name-servers '("192.168.1.2"))
11925 @cindex network management
11926 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
11927 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
11928 management daemon that aims to simplify wired and wireless networking.
11930 This service adds the @var{wicd} package to the global profile, providing
11931 several commands to interact with the daemon and configure networking:
11932 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
11933 and @command{wicd-curses} user interfaces.
11936 @cindex ModemManager
11938 @defvr {Scheme Variable} modem-manager-service-type
11939 This is the service type for the
11940 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
11941 service. The value for this service type is a
11942 @code{modem-manager-configuration} record.
11944 This service is part of @code{%desktop-services} (@pxref{Desktop
11948 @deftp {Data Type} modem-manager-configuration
11949 Data type representing the configuration of ModemManager.
11952 @item @code{modem-manager} (default: @code{modem-manager})
11953 The ModemManager package to use.
11958 @cindex NetworkManager
11960 @defvr {Scheme Variable} network-manager-service-type
11961 This is the service type for the
11962 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
11963 service. The value for this service type is a
11964 @code{network-manager-configuration} record.
11966 This service is part of @code{%desktop-services} (@pxref{Desktop
11970 @deftp {Data Type} network-manager-configuration
11971 Data type representing the configuration of NetworkManager.
11974 @item @code{network-manager} (default: @code{network-manager})
11975 The NetworkManager package to use.
11977 @item @code{dns} (default: @code{"default"})
11978 Processing mode for DNS, which affects how NetworkManager uses the
11979 @code{resolv.conf} configuration file.
11983 NetworkManager will update @code{resolv.conf} to reflect the nameservers
11984 provided by currently active connections.
11987 NetworkManager will run @code{dnsmasq} as a local caching nameserver,
11988 using a "split DNS" configuration if you are connected to a VPN, and
11989 then update @code{resolv.conf} to point to the local nameserver.
11992 NetworkManager will not modify @code{resolv.conf}.
11995 @item @code{vpn-plugins} (default: @code{'()})
11996 This is the list of available plugins for virtual private networks
11997 (VPNs). An example of this is the @code{network-manager-openvpn}
11998 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
12004 @deffn {Scheme Variable} connman-service-type
12005 This is the service type to run @url{https://01.org/connman,Connman},
12006 a network connection manager.
12008 Its value must be an
12009 @code{connman-configuration} record as in this example:
12012 (service connman-service-type
12013 (connman-configuration
12014 (disable-vpn? #t)))
12017 See below for details about @code{connman-configuration}.
12020 @deftp {Data Type} connman-configuration
12021 Data Type representing the configuration of connman.
12024 @item @code{connman} (default: @var{connman})
12025 The connman package to use.
12027 @item @code{disable-vpn?} (default: @code{#f})
12028 When true, disable connman's vpn plugin.
12032 @cindex WPA Supplicant
12033 @defvr {Scheme Variable} wpa-supplicant-service-type
12034 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
12035 supplicant}, an authentication daemon required to authenticate against
12036 encrypted WiFi or ethernet networks.
12039 @deftp {Data Type} wpa-supplicant-configuration
12040 Data type representing the configuration of WPA Supplicant.
12042 It takes the following parameters:
12045 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
12046 The WPA Supplicant package to use.
12048 @item @code{dbus?} (default: @code{#t})
12049 Whether to listen for requests on D-Bus.
12051 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
12052 Where to store the PID file.
12054 @item @code{interface} (default: @code{#f})
12055 If this is set, it must specify the name of a network interface that
12056 WPA supplicant will control.
12058 @item @code{config-file} (default: @code{#f})
12059 Optional configuration file to use.
12061 @item @code{extra-options} (default: @code{'()})
12062 List of additional command-line arguments to pass to the daemon.
12067 @defvr {Scheme Variable} iptables-service-type
12068 This is the service type to set up an iptables configuration. iptables is a
12069 packet filtering framework supported by the Linux kernel. This service
12070 supports configuring iptables for both IPv4 and IPv6. A simple example
12071 configuration rejecting all incoming connections except those to the ssh port
12075 (service iptables-service-type
12076 (iptables-configuration
12077 (ipv4-rules (plain-file "iptables.rules" "*filter
12081 -A INPUT -p tcp --dport 22 -j ACCEPT
12082 -A INPUT -j REJECT --reject-with icmp-port-unreachable
12085 (ipv6-rules (plain-file "ip6tables.rules" "*filter
12089 -A INPUT -p tcp --dport 22 -j ACCEPT
12090 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
12096 @deftp {Data Type} iptables-configuration
12097 The data type representing the configuration of iptables.
12100 @item @code{iptables} (default: @code{iptables})
12101 The iptables package that provides @code{iptables-restore} and
12102 @code{ip6tables-restore}.
12103 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
12104 The iptables rules to use. It will be passed to @code{iptables-restore}.
12105 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12107 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
12108 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
12109 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12114 @cindex NTP (Network Time Protocol), service
12115 @cindex real time clock
12116 @defvr {Scheme Variable} ntp-service-type
12117 This is the type of the service running the @uref{http://www.ntp.org,
12118 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
12119 system clock synchronized with that of the specified NTP servers.
12121 The value of this service is an @code{ntpd-configuration} object, as described
12125 @deftp {Data Type} ntp-configuration
12126 This is the data type for the NTP service configuration.
12129 @item @code{servers} (default: @code{%ntp-servers})
12130 This is the list of servers (host names) with which @command{ntpd} will be
12133 @item @code{allow-large-adjustment?} (default: @code{#f})
12134 This determines whether @command{ntpd} is allowed to make an initial
12135 adjustment of more than 1,000 seconds.
12137 @item @code{ntp} (default: @code{ntp})
12138 The NTP package to use.
12142 @defvr {Scheme Variable} %ntp-servers
12143 List of host names used as the default NTP servers. These are servers of the
12144 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
12148 @deffn {Scheme Procedure} openntpd-service-type
12149 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
12150 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
12151 clock synchronized with that of the given servers.
12155 openntpd-service-type
12156 (openntpd-configuration
12157 (listen-on '("127.0.0.1" "::1"))
12158 (sensor '("udcf0 correction 70000"))
12159 (constraint-from '("www.gnu.org"))
12160 (constraints-from '("https://www.google.com/"))
12161 (allow-large-adjustment? #t)))
12166 @deftp {Data Type} openntpd-configuration
12168 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
12169 The openntpd executable to use.
12170 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
12171 A list of local IP addresses or hostnames the ntpd daemon should listen on.
12172 @item @code{query-from} (default: @code{'()})
12173 A list of local IP address the ntpd daemon should use for outgoing queries.
12174 @item @code{sensor} (default: @code{'()})
12175 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
12176 will listen to each sensor that acutally exists and ignore non-existant ones.
12177 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
12179 @item @code{server} (default: @var{%ntp-servers})
12180 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
12181 @item @code{servers} (default: @code{'()})
12182 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
12183 @item @code{constraint-from} (default: @code{'()})
12184 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
12185 This time information is not used for precision but acts as an authenticated
12186 constraint, thereby reducing the impact of unauthenticated NTP
12187 man-in-the-middle attacks.
12188 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
12190 @item @code{constraints-from} (default: @code{'()})
12191 As with constraint from, specify a list of URLs, IP addresses or hostnames of
12192 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
12193 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
12194 @item @code{allow-large-adjustment?} (default: @code{#f})
12195 Determines if @code{ntpd} is allowed to make an initial adjustment of more
12201 @deffn {Scheme variable} inetd-service-type
12202 This service runs the @command{inetd} (@pxref{inetd invocation,,,
12203 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
12204 connections on internet sockets, and lazily starts the specified server
12205 program when a connection is made on one of these sockets.
12207 The value of this service is an @code{inetd-configuration} object. The
12208 following example configures the @command{inetd} daemon to provide the
12209 built-in @command{echo} service, as well as an smtp service which
12210 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
12211 gateway @code{hostname}:
12216 (inetd-configuration
12220 (socket-type 'stream)
12227 (socket-type 'stream)
12231 (program (file-append openssh "/bin/ssh"))
12233 '("ssh" "-qT" "-i" "/path/to/ssh_key"
12234 "-W" "smtp-server:25" "user@@hostname")))))
12237 See below for more details about @code{inetd-configuration}.
12240 @deftp {Data Type} inetd-configuration
12241 Data type representing the configuration of @command{inetd}.
12244 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
12245 The @command{inetd} executable to use.
12247 @item @code{entries} (default: @code{'()})
12248 A list of @command{inetd} service entries. Each entry should be created
12249 by the @code{inetd-entry} constructor.
12253 @deftp {Data Type} inetd-entry
12254 Data type representing an entry in the @command{inetd} configuration.
12255 Each entry corresponds to a socket where @command{inetd} will listen for
12259 @item @code{node} (default: @code{#f})
12260 Optional string, a comma-separated list of local addresses
12261 @command{inetd} should use when listening for this service.
12262 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
12263 description of all options.
12265 A string, the name must correspond to an entry in @code{/etc/services}.
12266 @item @code{socket-type}
12267 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
12269 @item @code{protocol}
12270 A string, must correspond to an entry in @code{/etc/protocols}.
12271 @item @code{wait?} (default: @code{#t})
12272 Whether @command{inetd} should wait for the server to exit before
12273 listening to new service requests.
12275 A string containing the user (and, optionally, group) name of the user
12276 as whom the server should run. The group name can be specified in a
12277 suffix, separated by a colon or period, i.e.@: @code{"user"},
12278 @code{"user:group"} or @code{"user.group"}.
12279 @item @code{program} (default: @code{"internal"})
12280 The server program which will serve the requests, or @code{"internal"}
12281 if @command{inetd} should use a built-in service.
12282 @item @code{arguments} (default: @code{'()})
12283 A list strings or file-like objects, which are the server program's
12284 arguments, starting with the zeroth argument, i.e.@: the name of the
12285 program itself. For @command{inetd}'s internal services, this entry
12286 must be @code{'()} or @code{'("internal")}.
12289 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
12290 detailed discussion of each configuration field.
12294 @defvr {Scheme Variable} tor-service-type
12295 This is the type for a service that runs the @uref{https://torproject.org,
12296 Tor} anonymous networking daemon. The service is configured using a
12297 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
12298 @code{tor} unprivileged user, which is a member of the @code{tor} group.
12302 @deftp {Data Type} tor-configuration
12304 @item @code{tor} (default: @code{tor})
12305 The package that provides the Tor daemon. This package is expected to provide
12306 the daemon at @file{bin/tor} relative to its output directory. The default
12307 package is the @uref{https://www.torproject.org, Tor Project's}
12310 @item @code{config-file} (default: @code{(plain-file "empty" "")})
12311 The configuration file to use. It will be appended to a default configuration
12312 file, and the final configuration file will be passed to @code{tor} via its
12313 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
12314 file-like objects}). See @code{man tor} for details on the configuration file
12317 @item @code{hidden-services} (default: @code{'()})
12318 The list of @code{<hidden-service>} records to use. For any hidden service
12319 you include in this list, appropriate configuration to enable the hidden
12320 service will be automatically added to the default configuration file. You
12321 may conveniently create @code{<hidden-service>} records using the
12322 @code{tor-hidden-service} procedure described below.
12324 @item @code{socks-socket-type} (default: @code{'tcp})
12325 The default socket type that Tor should use for its SOCKS socket. This must
12326 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
12327 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
12328 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
12329 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
12332 If you want to customize the SOCKS socket in more detail, leave
12333 @code{socks-socket-type} at its default value of @code{'tcp} and use
12334 @code{config-file} to override the default by providing your own
12335 @code{SocksPort} option.
12339 @cindex hidden service
12340 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
12341 Define a new Tor @dfn{hidden service} called @var{name} and implementing
12342 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
12345 '((22 "127.0.0.1:22")
12346 (80 "127.0.0.1:8080"))
12349 In this example, port 22 of the hidden service is mapped to local port 22, and
12350 port 80 is mapped to local port 8080.
12352 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
12353 the @file{hostname} file contains the @code{.onion} host name for the hidden
12356 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
12357 project's documentation} for more information.
12360 The @code{(gnu services rsync)} module provides the following services:
12362 You might want an rsync daemon if you have files that you want available
12363 so anyone (or just yourself) can download existing files or upload new
12366 @deffn {Scheme Variable} rsync-service-type
12367 This is the type for the @uref{https://rsync.samba.org, rsync} rsync daemon,
12368 @command{rsync-configuration} record as in this example:
12371 (service rsync-service-type)
12374 See below for details about @code{rsync-configuration}.
12377 @deftp {Data Type} rsync-configuration
12378 Data type representing the configuration for @code{rsync-service}.
12381 @item @code{package} (default: @var{rsync})
12382 @code{rsync} package to use.
12384 @item @code{port-number} (default: @code{873})
12385 TCP port on which @command{rsync} listens for incoming connections. If port
12386 is less than @code{1024} @command{rsync} needs to be started as the
12387 @code{root} user and group.
12389 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
12390 Name of the file where @command{rsync} writes its PID.
12392 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
12393 Name of the file where @command{rsync} writes its lock file.
12395 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
12396 Name of the file where @command{rsync} writes its log file.
12398 @item @code{use-chroot?} (default: @var{#t})
12399 Whether to use chroot for @command{rsync} shared directory.
12401 @item @code{share-path} (default: @file{/srv/rsync})
12402 Location of the @command{rsync} shared directory.
12404 @item @code{share-comment} (default: @code{"Rsync share"})
12405 Comment of the @command{rsync} shared directory.
12407 @item @code{read-only?} (default: @var{#f})
12408 Read-write permissions to shared directory.
12410 @item @code{timeout} (default: @code{300})
12411 I/O timeout in seconds.
12413 @item @code{user} (default: @var{"root"})
12414 Owner of the @code{rsync} process.
12416 @item @code{group} (default: @var{"root"})
12417 Group of the @code{rsync} process.
12419 @item @code{uid} (default: @var{"rsyncd"})
12420 User name or user ID that file transfers to and from that module should take
12421 place as when the daemon was run as @code{root}.
12423 @item @code{gid} (default: @var{"rsyncd"})
12424 Group name or group ID that will be used when accessing the module.
12429 Furthermore, @code{(gnu services ssh)} provides the following services.
12433 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
12434 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
12435 [#:allow-empty-passwords? #f] [#:root-login? #f] @
12436 [#:syslog-output? #t] [#:x11-forwarding? #t] @
12437 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
12438 [#:public-key-authentication? #t] [#:initialize? #t]
12439 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
12440 @var{host-key} must designate a file containing the host key, and readable
12443 When @var{daemonic?} is true, @command{lshd} will detach from the
12444 controlling terminal and log its output to syslogd, unless one sets
12445 @var{syslog-output?} to false. Obviously, it also makes lsh-service
12446 depend on existence of syslogd service. When @var{pid-file?} is true,
12447 @command{lshd} writes its PID to the file called @var{pid-file}.
12449 When @var{initialize?} is true, automatically create the seed and host key
12450 upon service activation if they do not exist yet. This may take long and
12451 require interaction.
12453 When @var{initialize?} is false, it is up to the user to initialize the
12454 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
12455 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
12456 basics,,, lsh, LSH Manual}).
12458 When @var{interfaces} is empty, lshd listens for connections on all the
12459 network interfaces; otherwise, @var{interfaces} must be a list of host names
12462 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
12463 passwords, and @var{root-login?} specifies whether to accept log-ins as
12466 The other options should be self-descriptive.
12471 @deffn {Scheme Variable} openssh-service-type
12472 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
12473 shell daemon, @command{sshd}. Its value must be an
12474 @code{openssh-configuration} record as in this example:
12477 (service openssh-service-type
12478 (openssh-configuration
12479 (x11-forwarding? #t)
12480 (permit-root-login 'without-password)
12482 `(("alice" ,(local-file "alice.pub"))
12483 ("bob" ,(local-file "bob.pub"))))))
12486 See below for details about @code{openssh-configuration}.
12488 This service can be extended with extra authorized keys, as in this
12492 (service-extension openssh-service-type
12493 (const `(("charlie"
12494 ,(local-file "charlie.pub")))))
12498 @deftp {Data Type} openssh-configuration
12499 This is the configuration record for OpenSSH's @command{sshd}.
12502 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
12503 Name of the file where @command{sshd} writes its PID.
12505 @item @code{port-number} (default: @code{22})
12506 TCP port on which @command{sshd} listens for incoming connections.
12508 @item @code{permit-root-login} (default: @code{#f})
12509 This field determines whether and when to allow logins as root. If
12510 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
12511 If it's the symbol @code{'without-password}, then root logins are
12512 permitted but not with password-based authentication.
12514 @item @code{allow-empty-passwords?} (default: @code{#f})
12515 When true, users with empty passwords may log in. When false, they may
12518 @item @code{password-authentication?} (default: @code{#t})
12519 When true, users may log in with their password. When false, they have
12520 other authentication methods.
12522 @item @code{public-key-authentication?} (default: @code{#t})
12523 When true, users may log in using public key authentication. When
12524 false, users have to use other authentication method.
12526 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
12527 This is used only by protocol version 2.
12529 @item @code{x11-forwarding?} (default: @code{#f})
12530 When true, forwarding of X11 graphical client connections is
12531 enabled---in other words, @command{ssh} options @option{-X} and
12532 @option{-Y} will work.
12534 @item @code{allow-agent-forwarding?} (default: @code{#t})
12535 Whether to allow agent forwarding.
12537 @item @code{allow-tcp-forwarding?} (default: @code{#t})
12538 Whether to allow TCP forwarding.
12540 @item @code{gateway-ports?} (default: @code{#f})
12541 Whether to allow gateway ports.
12543 @item @code{challenge-response-authentication?} (default: @code{#f})
12544 Specifies whether challenge response authentication is allowed (e.g.@: via
12547 @item @code{use-pam?} (default: @code{#t})
12548 Enables the Pluggable Authentication Module interface. If set to
12549 @code{#t}, this will enable PAM authentication using
12550 @code{challenge-response-authentication?} and
12551 @code{password-authentication?}, in addition to PAM account and session
12552 module processing for all authentication types.
12554 Because PAM challenge response authentication usually serves an
12555 equivalent role to password authentication, you should disable either
12556 @code{challenge-response-authentication?} or
12557 @code{password-authentication?}.
12559 @item @code{print-last-log?} (default: @code{#t})
12560 Specifies whether @command{sshd} should print the date and time of the
12561 last user login when a user logs in interactively.
12563 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
12564 Configures external subsystems (e.g.@: file transfer daemon).
12566 This is a list of two-element lists, each of which containing the
12567 subsystem name and a command (with optional arguments) to execute upon
12570 The command @command{internal-sftp} implements an in-process SFTP
12571 server. Alternately, one can specify the @command{sftp-server} command:
12573 (service openssh-service-type
12574 (openssh-configuration
12576 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
12579 @item @code{accepted-environment} (default: @code{'()})
12580 List of strings describing which environment variables may be exported.
12582 Each string gets on its own line. See the @code{AcceptEnv} option in
12583 @code{man sshd_config}.
12585 This example allows ssh-clients to export the @code{COLORTERM} variable.
12586 It is set by terminal emulators, which support colors. You can use it in
12587 your shell's ressource file to enable colors for the prompt and commands
12588 if this variable is set.
12591 (service openssh-service-type
12592 (openssh-configuration
12593 (accepted-environment '("COLORTERM"))))
12596 @item @code{authorized-keys} (default: @code{'()})
12597 @cindex authorized keys, SSH
12598 @cindex SSH authorized keys
12599 This is the list of authorized keys. Each element of the list is a user
12600 name followed by one or more file-like objects that represent SSH public
12604 (openssh-configuration
12606 `(("rekado" ,(local-file "rekado.pub"))
12607 ("chris" ,(local-file "chris.pub"))
12608 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
12612 registers the specified public keys for user accounts @code{rekado},
12613 @code{chris}, and @code{root}.
12615 Additional authorized keys can be specified @i{via}
12616 @code{service-extension}.
12618 Note that this does @emph{not} interfere with the use of
12619 @file{~/.ssh/authorized_keys}.
12621 @item @code{log-level} (default: @code{'info})
12622 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
12623 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
12624 page for @file{sshd_config} for the full list of level names.
12626 @item @code{extra-content} (default: @code{""})
12627 This field can be used to append arbitrary text to the configuration file. It
12628 is especially useful for elaborate configurations that cannot be expressed
12629 otherwise. This configuration, for example, would generally disable root
12630 logins, but permit them from one specific IP address:
12633 (openssh-configuration
12635 Match Address 192.168.0.1
12636 PermitRootLogin yes"))
12642 @deffn {Scheme Procedure} dropbear-service [@var{config}]
12643 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
12644 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
12647 For example, to specify a Dropbear service listening on port 1234, add
12648 this call to the operating system's @code{services} field:
12651 (dropbear-service (dropbear-configuration
12652 (port-number 1234)))
12656 @deftp {Data Type} dropbear-configuration
12657 This data type represents the configuration of a Dropbear SSH daemon.
12660 @item @code{dropbear} (default: @var{dropbear})
12661 The Dropbear package to use.
12663 @item @code{port-number} (default: 22)
12664 The TCP port where the daemon waits for incoming connections.
12666 @item @code{syslog-output?} (default: @code{#t})
12667 Whether to enable syslog output.
12669 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
12670 File name of the daemon's PID file.
12672 @item @code{root-login?} (default: @code{#f})
12673 Whether to allow @code{root} logins.
12675 @item @code{allow-empty-passwords?} (default: @code{#f})
12676 Whether to allow empty passwords.
12678 @item @code{password-authentication?} (default: @code{#t})
12679 Whether to enable password-based authentication.
12683 @defvr {Scheme Variable} %facebook-host-aliases
12684 This variable contains a string for use in @file{/etc/hosts}
12685 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
12686 line contains a entry that maps a known server name of the Facebook
12687 on-line service---e.g., @code{www.facebook.com}---to the local
12688 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
12690 This variable is typically used in the @code{hosts-file} field of an
12691 @code{operating-system} declaration (@pxref{operating-system Reference,
12692 @file{/etc/hosts}}):
12695 (use-modules (gnu) (guix))
12698 (host-name "mymachine")
12701 ;; Create a /etc/hosts file with aliases for "localhost"
12702 ;; and "mymachine", as well as for Facebook servers.
12703 (plain-file "hosts"
12704 (string-append (local-host-aliases host-name)
12705 %facebook-host-aliases))))
12708 This mechanism can prevent programs running locally, such as Web
12709 browsers, from accessing Facebook.
12712 The @code{(gnu services avahi)} provides the following definition.
12714 @defvr {Scheme Variable} avahi-service-type
12715 This is the service that runs @command{avahi-daemon}, a system-wide
12716 mDNS/DNS-SD responder that allows for service discovery and
12717 ``zero-configuration'' host name lookups (see @uref{http://avahi.org/}).
12718 Its value must be a @code{zero-configuration} record---see below.
12720 This service extends the name service cache daemon (nscd) so that it can
12721 resolve @code{.local} host names using
12722 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
12723 Service Switch}, for information on host name resolution.
12725 Additionally, add the @var{avahi} package to the system profile so that
12726 commands such as @command{avahi-browse} are directly usable.
12729 @deftp {Data Type} avahi-configuration
12730 Data type representation the configuration for Avahi.
12734 @item @code{host-name} (default: @code{#f})
12735 If different from @code{#f}, use that as the host name to
12736 publish for this machine; otherwise, use the machine's actual host name.
12738 @item @code{publish?} (default: @code{#t})
12739 When true, allow host names and services to be published (broadcast) over the
12742 @item @code{publish-workstation?} (default: @code{#t})
12743 When true, @command{avahi-daemon} publishes the machine's host name and IP
12744 address via mDNS on the local network. To view the host names published on
12745 your local network, you can run:
12748 avahi-browse _workstation._tcp
12751 @item @code{wide-area?} (default: @code{#f})
12752 When true, DNS-SD over unicast DNS is enabled.
12754 @item @code{ipv4?} (default: @code{#t})
12755 @itemx @code{ipv6?} (default: @code{#t})
12756 These fields determine whether to use IPv4/IPv6 sockets.
12758 @item @code{domains-to-browse} (default: @code{'()})
12759 This is a list of domains to browse.
12763 @deffn {Scheme Variable} openvswitch-service-type
12764 This is the type of the @uref{http://www.openvswitch.org, Open vSwitch}
12765 service, whose value should be an @code{openvswitch-configuration}
12769 @deftp {Data Type} openvswitch-configuration
12770 Data type representing the configuration of Open vSwitch, a multilayer
12771 virtual switch which is designed to enable massive network automation
12772 through programmatic extension.
12775 @item @code{package} (default: @var{openvswitch})
12776 Package object of the Open vSwitch.
12782 @subsection X Window
12785 @cindex X Window System
12786 @cindex login manager
12787 Support for the X Window graphical display system---specifically
12788 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
12789 there is no @code{xorg-service} procedure. Instead, the X server is
12790 started by the @dfn{login manager}, by default SLiM.
12792 @cindex window manager
12793 To use X11, you must install at least one @dfn{window manager}---for
12794 example the @code{windowmaker} or @code{openbox} packages---preferably
12795 by adding it to the @code{packages} field of your operating system
12796 definition (@pxref{operating-system Reference, system-wide packages}).
12798 @defvr {Scheme Variable} slim-service-type
12799 This is the type for the SLiM graphical login manager for X11.
12801 @cindex session types (X11)
12802 @cindex X11 session types
12803 SLiM looks for @dfn{session types} described by the @file{.desktop} files in
12804 @file{/run/current-system/profile/share/xsessions} and allows users to
12805 choose a session from the log-in screen using @kbd{F1}. Packages such
12806 as @code{xfce}, @code{sawfish}, and @code{ratpoison} provide
12807 @file{.desktop} files; adding them to the system-wide set of packages
12808 automatically makes them available at the log-in screen.
12810 In addition, @file{~/.xsession} files are honored. When available,
12811 @file{~/.xsession} must be an executable that starts a window manager
12812 and/or other X clients.
12815 @deftp {Data Type} slim-configuration
12816 Data type representing the configuration of @code{slim-service-type}.
12819 @item @code{allow-empty-passwords?} (default: @code{#t})
12820 Whether to allow logins with empty passwords.
12822 @item @code{auto-login?} (default: @code{#f})
12823 @itemx @code{default-user} (default: @code{""})
12824 When @code{auto-login?} is false, SLiM presents a log-in screen.
12826 When @code{auto-login?} is true, SLiM logs in directly as
12827 @code{default-user}.
12829 @item @code{theme} (default: @code{%default-slim-theme})
12830 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
12831 The graphical theme to use and its name.
12833 @item @code{auto-login-session} (default: @code{#f})
12834 If true, this must be the name of the executable to start as the default
12835 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
12837 If false, a session described by one of the available @file{.desktop}
12838 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
12842 You must install at least one window manager in the system profile or in
12843 your user profile. Failing to do that, if @code{auto-login-session} is
12844 false, you will be unable to log in.
12847 @item @code{startx} (default: @code{(xorg-start-command)})
12848 The command used to start the X11 graphical server.
12850 @item @code{xauth} (default: @code{xauth})
12851 The XAuth package to use.
12853 @item @code{shepherd} (default: @code{shepherd})
12854 The Shepherd package used when invoking @command{halt} and
12857 @item @code{sessreg} (default: @code{sessreg})
12858 The sessreg package used in order to register the session.
12860 @item @code{slim} (default: @code{slim})
12861 The SLiM package to use.
12865 @defvr {Scheme Variable} %default-theme
12866 @defvrx {Scheme Variable} %default-theme-name
12867 The default SLiM theme and its name.
12871 @deftp {Data Type} sddm-configuration
12872 This is the data type representing the sddm service configuration.
12875 @item @code{display-server} (default: "x11")
12876 Select display server to use for the greeter. Valid values are "x11"
12879 @item @code{numlock} (default: "on")
12880 Valid values are "on", "off" or "none".
12882 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
12883 Command to run when halting.
12885 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
12886 Command to run when rebooting.
12888 @item @code{theme} (default "maldives")
12889 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
12891 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
12892 Directory to look for themes.
12894 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
12895 Directory to look for faces.
12897 @item @code{default-path} (default "/run/current-system/profile/bin")
12898 Default PATH to use.
12900 @item @code{minimum-uid} (default 1000)
12901 Minimum UID to display in SDDM.
12903 @item @code{maximum-uid} (default 2000)
12904 Maximum UID to display in SDDM
12906 @item @code{remember-last-user?} (default #t)
12907 Remember last user.
12909 @item @code{remember-last-session?} (default #t)
12910 Remember last session.
12912 @item @code{hide-users} (default "")
12913 Usernames to hide from SDDM greeter.
12915 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
12916 Users with shells listed will be hidden from the SDDM greeter.
12918 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
12919 Script to run before starting a wayland session.
12921 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
12922 Directory to look for desktop files starting wayland sessions.
12924 @item @code{xorg-server-path} (default @code{xorg-start-command})
12925 Path to xorg-server.
12927 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
12930 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
12933 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
12934 Script to run after starting xorg-server.
12936 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
12937 Script to run before stopping xorg-server.
12939 @item @code{xsession-command} (default: @code{xinitrc})
12940 Script to run before starting a X session.
12942 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
12943 Directory to look for desktop files starting X sessions.
12945 @item @code{minimum-vt} (default: 7)
12948 @item @code{xserver-arguments} (default "-nolisten tcp")
12949 Arguments to pass to xorg-server.
12951 @item @code{auto-login-user} (default "")
12952 User to use for auto-login.
12954 @item @code{auto-login-session} (default "")
12955 Desktop file to use for auto-login.
12957 @item @code{relogin?} (default #f)
12958 Relogin after logout.
12963 @cindex login manager
12965 @deffn {Scheme Procedure} sddm-service config
12966 Return a service that spawns the SDDM graphical login manager for config of
12967 type @code{<sddm-configuration>}.
12970 (sddm-service (sddm-configuration
12971 (auto-login-user "Alice")
12972 (auto-login-session "xfce.desktop")))
12976 @deffn {Scheme Procedure} xorg-start-command [#:guile] @
12977 [#:modules %default-xorg-modules] @
12978 [#:fonts %default-xorg-fonts] @
12979 [#:configuration-file (xorg-configuration-file @dots{})] @
12980 [#:xorg-server @var{xorg-server}]
12981 Return a @code{startx} script in which @var{modules}, a list of X module
12982 packages, and @var{fonts}, a list of X font directories, are available. See
12983 @code{xorg-wrapper} for more details on the arguments. The result should be
12984 used in place of @code{startx}.
12986 Usually the X server is started by a login manager.
12989 @deffn {Scheme Procedure} xorg-configuration-file @
12990 [#:modules %default-xorg-modules] @
12991 [#:fonts %default-xorg-fonts] @
12992 [#:drivers '()] [#:resolutions '()] [#:extra-config '()]
12993 Return a configuration file for the Xorg server containing search paths for
12994 all the common drivers.
12996 @var{modules} must be a list of @dfn{module packages} loaded by the Xorg
12997 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
12998 @var{fonts} must be a list of font directories to add to the server's
13001 @var{drivers} must be either the empty list, in which case Xorg chooses a
13002 graphics driver automatically, or a list of driver names that will be tried in
13003 this order---e.g., @code{("modesetting" "vesa")}.
13005 Likewise, when @var{resolutions} is the empty list, Xorg chooses an
13006 appropriate screen resolution; otherwise, it must be a list of
13007 resolutions---e.g., @code{((1024 768) (640 480))}.
13009 Last, @var{extra-config} is a list of strings or objects appended to the
13010 configuration file. It is used to pass extra text to be
13011 added verbatim to the configuration file.
13014 @cindex keyboard layout
13015 This procedure is especially useful to configure a different keyboard layout
13016 than the default US keymap. For instance, to use the ``bépo'' keymap by
13017 default on the display manager:
13021 "Section \"InputClass\"
13022 Identifier \"evdev keyboard catchall\"
13024 MatchIsKeyboard \"on\"
13025 Option \"xkb_layout\" \"fr\"
13026 Option \"xkb_variant\" \"bepo\"
13032 (modify-services %desktop-services
13033 (slim-service-type config =>
13034 (slim-configuration
13036 (startx (xorg-start-command
13037 #:configuration-file
13038 (xorg-configuration-file
13040 (list bepo-evdev)))))))))
13043 The @code{MatchIsKeyboard} line specifies that we only apply the configuration
13044 to keyboards. Without this line, other devices such as touchpad may not work
13045 correctly because they will be attached to the wrong driver. In this example,
13046 the user typically used @code{setxkbmap fr bepo} to set their favorite keymap
13047 once logged in. The first argument corresponds to the layout, while the second
13048 argument corresponds to the variant. The @code{xkb_variant} line can be omitted
13049 to select the default variant.
13052 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
13053 Add @var{package}, a package for a screen locker or screen saver whose
13054 command is @var{program}, to the set of setuid programs and add a PAM entry
13055 for it. For example:
13058 (screen-locker-service xlockmore "xlock")
13061 makes the good ol' XlockMore usable.
13065 @node Printing Services
13066 @subsection Printing Services
13068 @cindex printer support with CUPS
13069 The @code{(gnu services cups)} module provides a Guix service definition
13070 for the CUPS printing service. To add printer support to a GuixSD
13071 system, add a @code{cups-service} to the operating system definition:
13073 @deffn {Scheme Variable} cups-service-type
13074 The service type for the CUPS print server. Its value should be a valid
13075 CUPS configuration (see below). To use the default settings, simply
13078 (service cups-service-type)
13082 The CUPS configuration controls the basic things about your CUPS
13083 installation: what interfaces it listens on, what to do if a print job
13084 fails, how much logging to do, and so on. To actually add a printer,
13085 you have to visit the @url{http://localhost:631} URL, or use a tool such
13086 as GNOME's printer configuration services. By default, configuring a
13087 CUPS service will generate a self-signed certificate if needed, for
13088 secure connections to the print server.
13090 Suppose you want to enable the Web interface of CUPS and also add
13091 support for Epson printers @i{via} the @code{escpr} package and for HP
13092 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
13093 like this (you need to use the @code{(gnu packages cups)} module):
13096 (service cups-service-type
13097 (cups-configuration
13098 (web-interface? #t)
13100 (list cups-filters escpr hplip-minimal))))
13103 Note: If you wish to use the Qt5 based GUI which comes with the hplip
13104 package then it is suggested that you install the @code{hplip} package,
13105 either in your OS configuration file or as your user.
13107 The available configuration parameters follow. Each parameter
13108 definition is preceded by its type; for example, @samp{string-list foo}
13109 indicates that the @code{foo} parameter should be specified as a list of
13110 strings. There is also a way to specify the configuration as a string,
13111 if you have an old @code{cupsd.conf} file that you want to port over
13112 from some other system; see the end for more details.
13114 @c The following documentation was initially generated by
13115 @c (generate-documentation) in (gnu services cups). Manually maintained
13116 @c documentation is better, so we shouldn't hesitate to edit below as
13117 @c needed. However if the change you want to make to this documentation
13118 @c can be done in an automated way, it's probably easier to change
13119 @c (generate-documentation) than to make it below and have to deal with
13120 @c the churn as CUPS updates.
13123 Available @code{cups-configuration} fields are:
13125 @deftypevr {@code{cups-configuration} parameter} package cups
13129 @deftypevr {@code{cups-configuration} parameter} package-list extensions
13130 Drivers and other extensions to the CUPS package.
13133 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
13134 Configuration of where to write logs, what directories to use for print
13135 spools, and related privileged configuration parameters.
13137 Available @code{files-configuration} fields are:
13139 @deftypevr {@code{files-configuration} parameter} log-location access-log
13140 Defines the access log filename. Specifying a blank filename disables
13141 access log generation. The value @code{stderr} causes log entries to be
13142 sent to the standard error file when the scheduler is running in the
13143 foreground, or to the system log daemon when run in the background. The
13144 value @code{syslog} causes log entries to be sent to the system log
13145 daemon. The server name may be included in filenames using the string
13146 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
13148 Defaults to @samp{"/var/log/cups/access_log"}.
13151 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
13152 Where CUPS should cache data.
13154 Defaults to @samp{"/var/cache/cups"}.
13157 @deftypevr {@code{files-configuration} parameter} string config-file-perm
13158 Specifies the permissions for all configuration files that the scheduler
13161 Note that the permissions for the printers.conf file are currently
13162 masked to only allow access from the scheduler user (typically root).
13163 This is done because printer device URIs sometimes contain sensitive
13164 authentication information that should not be generally known on the
13165 system. There is no way to disable this security feature.
13167 Defaults to @samp{"0640"}.
13170 @deftypevr {@code{files-configuration} parameter} log-location error-log
13171 Defines the error log filename. Specifying a blank filename disables
13172 access log generation. The value @code{stderr} causes log entries to be
13173 sent to the standard error file when the scheduler is running in the
13174 foreground, or to the system log daemon when run in the background. The
13175 value @code{syslog} causes log entries to be sent to the system log
13176 daemon. The server name may be included in filenames using the string
13177 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
13179 Defaults to @samp{"/var/log/cups/error_log"}.
13182 @deftypevr {@code{files-configuration} parameter} string fatal-errors
13183 Specifies which errors are fatal, causing the scheduler to exit. The
13188 No errors are fatal.
13191 All of the errors below are fatal.
13194 Browsing initialization errors are fatal, for example failed connections
13195 to the DNS-SD daemon.
13198 Configuration file syntax errors are fatal.
13201 Listen or Port errors are fatal, except for IPv6 failures on the
13202 loopback or @code{any} addresses.
13205 Log file creation or write errors are fatal.
13208 Bad startup file permissions are fatal, for example shared TLS
13209 certificate and key files with world-read permissions.
13212 Defaults to @samp{"all -browse"}.
13215 @deftypevr {@code{files-configuration} parameter} boolean file-device?
13216 Specifies whether the file pseudo-device can be used for new printer
13217 queues. The URI @uref{file:///dev/null} is always allowed.
13219 Defaults to @samp{#f}.
13222 @deftypevr {@code{files-configuration} parameter} string group
13223 Specifies the group name or ID that will be used when executing external
13226 Defaults to @samp{"lp"}.
13229 @deftypevr {@code{files-configuration} parameter} string log-file-perm
13230 Specifies the permissions for all log files that the scheduler writes.
13232 Defaults to @samp{"0644"}.
13235 @deftypevr {@code{files-configuration} parameter} log-location page-log
13236 Defines the page log filename. Specifying a blank filename disables
13237 access log generation. The value @code{stderr} causes log entries to be
13238 sent to the standard error file when the scheduler is running in the
13239 foreground, or to the system log daemon when run in the background. The
13240 value @code{syslog} causes log entries to be sent to the system log
13241 daemon. The server name may be included in filenames using the string
13242 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
13244 Defaults to @samp{"/var/log/cups/page_log"}.
13247 @deftypevr {@code{files-configuration} parameter} string remote-root
13248 Specifies the username that is associated with unauthenticated accesses
13249 by clients claiming to be the root user. The default is @code{remroot}.
13251 Defaults to @samp{"remroot"}.
13254 @deftypevr {@code{files-configuration} parameter} file-name request-root
13255 Specifies the directory that contains print jobs and other HTTP request
13258 Defaults to @samp{"/var/spool/cups"}.
13261 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
13262 Specifies the level of security sandboxing that is applied to print
13263 filters, backends, and other child processes of the scheduler; either
13264 @code{relaxed} or @code{strict}. This directive is currently only
13265 used/supported on macOS.
13267 Defaults to @samp{strict}.
13270 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
13271 Specifies the location of TLS certificates and private keys. CUPS will
13272 look for public and private keys in this directory: a @code{.crt} files
13273 for PEM-encoded certificates and corresponding @code{.key} files for
13274 PEM-encoded private keys.
13276 Defaults to @samp{"/etc/cups/ssl"}.
13279 @deftypevr {@code{files-configuration} parameter} file-name server-root
13280 Specifies the directory containing the server configuration files.
13282 Defaults to @samp{"/etc/cups"}.
13285 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
13286 Specifies whether the scheduler calls fsync(2) after writing
13287 configuration or state files.
13289 Defaults to @samp{#f}.
13292 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
13293 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
13296 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
13297 Specifies the directory where temporary files are stored.
13299 Defaults to @samp{"/var/spool/cups/tmp"}.
13302 @deftypevr {@code{files-configuration} parameter} string user
13303 Specifies the user name or ID that is used when running external
13306 Defaults to @samp{"lp"}.
13310 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
13311 Specifies the logging level for the AccessLog file. The @code{config}
13312 level logs when printers and classes are added, deleted, or modified and
13313 when configuration files are accessed or updated. The @code{actions}
13314 level logs when print jobs are submitted, held, released, modified, or
13315 canceled, and any of the conditions for @code{config}. The @code{all}
13316 level logs all requests.
13318 Defaults to @samp{actions}.
13321 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
13322 Specifies whether to purge job history data automatically when it is no
13323 longer required for quotas.
13325 Defaults to @samp{#f}.
13328 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
13329 Specifies which protocols to use for local printer sharing.
13331 Defaults to @samp{dnssd}.
13334 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
13335 Specifies whether the CUPS web interface is advertised.
13337 Defaults to @samp{#f}.
13340 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
13341 Specifies whether shared printers are advertised.
13343 Defaults to @samp{#f}.
13346 @deftypevr {@code{cups-configuration} parameter} string classification
13347 Specifies the security classification of the server. Any valid banner
13348 name can be used, including "classified", "confidential", "secret",
13349 "topsecret", and "unclassified", or the banner can be omitted to disable
13350 secure printing functions.
13352 Defaults to @samp{""}.
13355 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
13356 Specifies whether users may override the classification (cover page) of
13357 individual print jobs using the @code{job-sheets} option.
13359 Defaults to @samp{#f}.
13362 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
13363 Specifies the default type of authentication to use.
13365 Defaults to @samp{Basic}.
13368 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
13369 Specifies whether encryption will be used for authenticated requests.
13371 Defaults to @samp{Required}.
13374 @deftypevr {@code{cups-configuration} parameter} string default-language
13375 Specifies the default language to use for text and web content.
13377 Defaults to @samp{"en"}.
13380 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
13381 Specifies the default paper size for new print queues. @samp{"Auto"}
13382 uses a locale-specific default, while @samp{"None"} specifies there is
13383 no default paper size. Specific size names are typically
13384 @samp{"Letter"} or @samp{"A4"}.
13386 Defaults to @samp{"Auto"}.
13389 @deftypevr {@code{cups-configuration} parameter} string default-policy
13390 Specifies the default access policy to use.
13392 Defaults to @samp{"default"}.
13395 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
13396 Specifies whether local printers are shared by default.
13398 Defaults to @samp{#t}.
13401 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
13402 Specifies the delay for updating of configuration and state files, in
13403 seconds. A value of 0 causes the update to happen as soon as possible,
13404 typically within a few milliseconds.
13406 Defaults to @samp{30}.
13409 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
13410 Specifies what to do when an error occurs. Possible values are
13411 @code{abort-job}, which will discard the failed print job;
13412 @code{retry-job}, which will retry the job at a later time;
13413 @code{retry-this-job}, which retries the failed job immediately; and
13414 @code{stop-printer}, which stops the printer.
13416 Defaults to @samp{stop-printer}.
13419 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
13420 Specifies the maximum cost of filters that are run concurrently, which
13421 can be used to minimize disk, memory, and CPU resource problems. A
13422 limit of 0 disables filter limiting. An average print to a
13423 non-PostScript printer needs a filter limit of about 200. A PostScript
13424 printer needs about half that (100). Setting the limit below these
13425 thresholds will effectively limit the scheduler to printing a single job
13428 Defaults to @samp{0}.
13431 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
13432 Specifies the scheduling priority of filters that are run to print a
13433 job. The nice value ranges from 0, the highest priority, to 19, the
13436 Defaults to @samp{0}.
13439 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
13440 Specifies whether to do reverse lookups on connecting clients. The
13441 @code{double} setting causes @code{cupsd} to verify that the hostname
13442 resolved from the address matches one of the addresses returned for that
13443 hostname. Double lookups also prevent clients with unregistered
13444 addresses from connecting to your server. Only set this option to
13445 @code{#t} or @code{double} if absolutely required.
13447 Defaults to @samp{#f}.
13450 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
13451 Specifies the number of seconds to wait before killing the filters and
13452 backend associated with a canceled or held job.
13454 Defaults to @samp{30}.
13457 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
13458 Specifies the interval between retries of jobs in seconds. This is
13459 typically used for fax queues but can also be used with normal print
13460 queues whose error policy is @code{retry-job} or
13461 @code{retry-current-job}.
13463 Defaults to @samp{30}.
13466 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
13467 Specifies the number of retries that are done for jobs. This is
13468 typically used for fax queues but can also be used with normal print
13469 queues whose error policy is @code{retry-job} or
13470 @code{retry-current-job}.
13472 Defaults to @samp{5}.
13475 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
13476 Specifies whether to support HTTP keep-alive connections.
13478 Defaults to @samp{#t}.
13481 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
13482 Specifies how long an idle client connection remains open, in seconds.
13484 Defaults to @samp{30}.
13487 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
13488 Specifies the maximum size of print files, IPP requests, and HTML form
13489 data. A limit of 0 disables the limit check.
13491 Defaults to @samp{0}.
13494 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
13495 Listens on the specified interfaces for connections. Valid values are
13496 of the form @var{address}:@var{port}, where @var{address} is either an
13497 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
13498 indicate all addresses. Values can also be file names of local UNIX
13499 domain sockets. The Listen directive is similar to the Port directive
13500 but allows you to restrict access to specific interfaces or networks.
13503 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
13504 Specifies the number of pending connections that will be allowed. This
13505 normally only affects very busy servers that have reached the MaxClients
13506 limit, but can also be triggered by large numbers of simultaneous
13507 connections. When the limit is reached, the operating system will
13508 refuse additional connections until the scheduler can accept the pending
13511 Defaults to @samp{128}.
13514 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
13515 Specifies a set of additional access controls.
13517 Available @code{location-access-controls} fields are:
13519 @deftypevr {@code{location-access-controls} parameter} file-name path
13520 Specifies the URI path to which the access control applies.
13523 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
13524 Access controls for all access to this path, in the same format as the
13525 @code{access-controls} of @code{operation-access-control}.
13527 Defaults to @samp{()}.
13530 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
13531 Access controls for method-specific access to this path.
13533 Defaults to @samp{()}.
13535 Available @code{method-access-controls} fields are:
13537 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
13538 If @code{#t}, apply access controls to all methods except the listed
13539 methods. Otherwise apply to only the listed methods.
13541 Defaults to @samp{#f}.
13544 @deftypevr {@code{method-access-controls} parameter} method-list methods
13545 Methods to which this access control applies.
13547 Defaults to @samp{()}.
13550 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
13551 Access control directives, as a list of strings. Each string should be
13552 one directive, such as "Order allow,deny".
13554 Defaults to @samp{()}.
13559 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
13560 Specifies the number of debugging messages that are retained for logging
13561 if an error occurs in a print job. Debug messages are logged regardless
13562 of the LogLevel setting.
13564 Defaults to @samp{100}.
13567 @deftypevr {@code{cups-configuration} parameter} log-level log-level
13568 Specifies the level of logging for the ErrorLog file. The value
13569 @code{none} stops all logging while @code{debug2} logs everything.
13571 Defaults to @samp{info}.
13574 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
13575 Specifies the format of the date and time in the log files. The value
13576 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
13578 Defaults to @samp{standard}.
13581 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
13582 Specifies the maximum number of simultaneous clients that are allowed by
13585 Defaults to @samp{100}.
13588 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
13589 Specifies the maximum number of simultaneous clients that are allowed
13590 from a single address.
13592 Defaults to @samp{100}.
13595 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
13596 Specifies the maximum number of copies that a user can print of each
13599 Defaults to @samp{9999}.
13602 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
13603 Specifies the maximum time a job may remain in the @code{indefinite}
13604 hold state before it is canceled. A value of 0 disables cancellation of
13607 Defaults to @samp{0}.
13610 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
13611 Specifies the maximum number of simultaneous jobs that are allowed. Set
13612 to 0 to allow an unlimited number of jobs.
13614 Defaults to @samp{500}.
13617 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
13618 Specifies the maximum number of simultaneous jobs that are allowed per
13619 printer. A value of 0 allows up to MaxJobs jobs per printer.
13621 Defaults to @samp{0}.
13624 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
13625 Specifies the maximum number of simultaneous jobs that are allowed per
13626 user. A value of 0 allows up to MaxJobs jobs per user.
13628 Defaults to @samp{0}.
13631 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
13632 Specifies the maximum time a job may take to print before it is
13633 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
13635 Defaults to @samp{10800}.
13638 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
13639 Specifies the maximum size of the log files before they are rotated, in
13640 bytes. The value 0 disables log rotation.
13642 Defaults to @samp{1048576}.
13645 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
13646 Specifies the maximum amount of time to allow between files in a
13647 multiple file print job, in seconds.
13649 Defaults to @samp{300}.
13652 @deftypevr {@code{cups-configuration} parameter} string page-log-format
13653 Specifies the format of PageLog lines. Sequences beginning with percent
13654 (@samp{%}) characters are replaced with the corresponding information,
13655 while all other characters are copied literally. The following percent
13656 sequences are recognized:
13660 insert a single percent character
13663 insert the value of the specified IPP attribute
13666 insert the number of copies for the current page
13669 insert the current page number
13672 insert the current date and time in common log format
13678 insert the printer name
13681 insert the username
13684 A value of the empty string disables page logging. The string @code{%p
13685 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
13686 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
13689 Defaults to @samp{""}.
13692 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
13693 Passes the specified environment variable(s) to child processes; a list
13696 Defaults to @samp{()}.
13699 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
13700 Specifies named access control policies.
13702 Available @code{policy-configuration} fields are:
13704 @deftypevr {@code{policy-configuration} parameter} string name
13705 Name of the policy.
13708 @deftypevr {@code{policy-configuration} parameter} string job-private-access
13709 Specifies an access list for a job's private values. @code{@@ACL} maps
13710 to the printer's requesting-user-name-allowed or
13711 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
13712 owner. @code{@@SYSTEM} maps to the groups listed for the
13713 @code{system-group} field of the @code{files-config} configuration,
13714 which is reified into the @code{cups-files.conf(5)} file. Other
13715 possible elements of the access list include specific user names, and
13716 @code{@@@var{group}} to indicate members of a specific group. The
13717 access list may also be simply @code{all} or @code{default}.
13719 Defaults to @samp{"@@OWNER @@SYSTEM"}.
13722 @deftypevr {@code{policy-configuration} parameter} string job-private-values
13723 Specifies the list of job values to make private, or @code{all},
13724 @code{default}, or @code{none}.
13726 Defaults to @samp{"job-name job-originating-host-name
13727 job-originating-user-name phone"}.
13730 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
13731 Specifies an access list for a subscription's private values.
13732 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
13733 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
13734 owner. @code{@@SYSTEM} maps to the groups listed for the
13735 @code{system-group} field of the @code{files-config} configuration,
13736 which is reified into the @code{cups-files.conf(5)} file. Other
13737 possible elements of the access list include specific user names, and
13738 @code{@@@var{group}} to indicate members of a specific group. The
13739 access list may also be simply @code{all} or @code{default}.
13741 Defaults to @samp{"@@OWNER @@SYSTEM"}.
13744 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
13745 Specifies the list of job values to make private, or @code{all},
13746 @code{default}, or @code{none}.
13748 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
13749 notify-subscriber-user-name notify-user-data"}.
13752 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
13753 Access control by IPP operation.
13755 Defaults to @samp{()}.
13759 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
13760 Specifies whether job files (documents) are preserved after a job is
13761 printed. If a numeric value is specified, job files are preserved for
13762 the indicated number of seconds after printing. Otherwise a boolean
13763 value applies indefinitely.
13765 Defaults to @samp{86400}.
13768 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
13769 Specifies whether the job history is preserved after a job is printed.
13770 If a numeric value is specified, the job history is preserved for the
13771 indicated number of seconds after printing. If @code{#t}, the job
13772 history is preserved until the MaxJobs limit is reached.
13774 Defaults to @samp{#t}.
13777 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
13778 Specifies the amount of time to wait for job completion before
13779 restarting the scheduler.
13781 Defaults to @samp{30}.
13784 @deftypevr {@code{cups-configuration} parameter} string rip-cache
13785 Specifies the maximum amount of memory to use when converting documents
13786 into bitmaps for a printer.
13788 Defaults to @samp{"128m"}.
13791 @deftypevr {@code{cups-configuration} parameter} string server-admin
13792 Specifies the email address of the server administrator.
13794 Defaults to @samp{"root@@localhost.localdomain"}.
13797 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
13798 The ServerAlias directive is used for HTTP Host header validation when
13799 clients connect to the scheduler from external interfaces. Using the
13800 special name @code{*} can expose your system to known browser-based DNS
13801 rebinding attacks, even when accessing sites through a firewall. If the
13802 auto-discovery of alternate names does not work, we recommend listing
13803 each alternate name with a ServerAlias directive instead of using
13806 Defaults to @samp{*}.
13809 @deftypevr {@code{cups-configuration} parameter} string server-name
13810 Specifies the fully-qualified host name of the server.
13812 Defaults to @samp{"localhost"}.
13815 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
13816 Specifies what information is included in the Server header of HTTP
13817 responses. @code{None} disables the Server header. @code{ProductOnly}
13818 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
13819 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
13820 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
13821 the output of the @code{uname} command. @code{Full} reports @code{CUPS
13822 2.0.0 (@var{uname}) IPP/2.0}.
13824 Defaults to @samp{Minimal}.
13827 @deftypevr {@code{cups-configuration} parameter} string set-env
13828 Set the specified environment variable to be passed to child processes.
13830 Defaults to @samp{"variable value"}.
13833 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
13834 Listens on the specified interfaces for encrypted connections. Valid
13835 values are of the form @var{address}:@var{port}, where @var{address} is
13836 either an IPv6 address enclosed in brackets, an IPv4 address, or
13837 @code{*} to indicate all addresses.
13839 Defaults to @samp{()}.
13842 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
13843 Sets encryption options. By default, CUPS only supports encryption
13844 using TLS v1.0 or higher using known secure cipher suites. The
13845 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
13846 required for some older clients that do not implement newer ones. The
13847 @code{AllowSSL3} option enables SSL v3.0, which is required for some
13848 older clients that do not support TLS v1.0.
13850 Defaults to @samp{()}.
13853 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
13854 Specifies whether the scheduler requires clients to strictly adhere to
13855 the IPP specifications.
13857 Defaults to @samp{#f}.
13860 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
13861 Specifies the HTTP request timeout, in seconds.
13863 Defaults to @samp{300}.
13867 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
13868 Specifies whether the web interface is enabled.
13870 Defaults to @samp{#f}.
13873 At this point you're probably thinking ``oh dear, Guix manual, I like
13874 you but you can stop already with the configuration options''. Indeed.
13875 However, one more point: it could be that you have an existing
13876 @code{cupsd.conf} that you want to use. In that case, you can pass an
13877 @code{opaque-cups-configuration} as the configuration of a
13878 @code{cups-service-type}.
13880 Available @code{opaque-cups-configuration} fields are:
13882 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
13886 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
13887 The contents of the @code{cupsd.conf}, as a string.
13890 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
13891 The contents of the @code{cups-files.conf} file, as a string.
13894 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
13895 strings of the same name, you could instantiate a CUPS service like
13899 (service cups-service-type
13900 (opaque-cups-configuration
13901 (cupsd.conf cupsd.conf)
13902 (cups-files.conf cups-files.conf)))
13906 @node Desktop Services
13907 @subsection Desktop Services
13909 The @code{(gnu services desktop)} module provides services that are
13910 usually useful in the context of a ``desktop'' setup---that is, on a
13911 machine running a graphical display server, possibly with graphical user
13912 interfaces, etc. It also defines services that provide specific desktop
13913 environments like GNOME, XFCE or MATE.
13915 To simplify things, the module defines a variable containing the set of
13916 services that users typically expect on a machine with a graphical
13917 environment and networking:
13919 @defvr {Scheme Variable} %desktop-services
13920 This is a list of services that builds upon @var{%base-services} and
13921 adds or adjusts services for a typical ``desktop'' setup.
13923 In particular, it adds a graphical login manager (@pxref{X Window,
13924 @code{slim-service}}), screen lockers, a network management tool
13925 (@pxref{Networking Services, @code{network-manager-service-type}}), energy and color
13926 management services, the @code{elogind} login and seat manager, the
13927 Polkit privilege service, the GeoClue location service, the
13928 AccountsService daemon that allows authorized users change system
13929 passwords, an NTP client (@pxref{Networking Services}), the Avahi
13930 daemon, and has the name service switch service configured to be able to
13931 use @code{nss-mdns} (@pxref{Name Service Switch, mDNS}).
13934 The @var{%desktop-services} variable can be used as the @code{services}
13935 field of an @code{operating-system} declaration (@pxref{operating-system
13936 Reference, @code{services}}).
13938 Additionally, the @code{gnome-desktop-service},
13939 @code{xfce-desktop-service}, @code{mate-desktop-service} and
13940 @code{enlightenment-desktop-service-type} procedures can add GNOME, XFCE, MATE
13941 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
13942 services like the backlight adjustment helpers and the power management
13943 utilities are added to the system, extending @code{polkit} and @code{dbus}
13944 appropriately, allowing GNOME to operate with elevated privileges on a
13945 limited number of special-purpose system interfaces. Additionally,
13946 adding a service made by @code{gnome-desktop-service} adds the GNOME
13947 metapackage to the system profile. Likewise, adding the XFCE service
13948 not only adds the @code{xfce} metapackage to the system profile, but it
13949 also gives the Thunar file manager the ability to open a ``root-mode''
13950 file management window, if the user authenticates using the
13951 administrator's password via the standard polkit graphical interface.
13952 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
13953 appropriately, allowing MATE to operate with elevated privileges on a
13954 limited number of special-purpose system interfaces. Additionally,
13955 adding a service made by @code{mate-desktop-service} adds the MATE
13956 metapackage to the system profile. ``Adding ENLIGHTENMENT'' means that
13957 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
13958 are set as setuid, allowing Enlightenment's screen locker and other
13959 functionality to work as expetected.
13961 The desktop environments in Guix use the Xorg display server by
13962 default. If you'd like to use the newer display server protocol
13963 called Wayland, you need to use the @code{sddm-service} instead of the
13964 @code{slim-service} for the graphical login manager. You should then
13965 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
13966 also try starting GNOME on Wayland manually from a TTY with the
13967 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
13968 gnome-session``. Currently only GNOME has support for Wayland.
13970 @deffn {Scheme Procedure} gnome-desktop-service
13971 Return a service that adds the @code{gnome} package to the system
13972 profile, and extends polkit with the actions from
13973 @code{gnome-settings-daemon}.
13976 @deffn {Scheme Procedure} xfce-desktop-service
13977 Return a service that adds the @code{xfce} package to the system profile,
13978 and extends polkit with the ability for @code{thunar} to manipulate the
13979 file system as root from within a user session, after the user has
13980 authenticated with the administrator's password.
13983 @deffn {Scheme Procedure} mate-desktop-service
13984 Return a service that adds the @code{mate} package to the system
13985 profile, and extends polkit with the actions from
13986 @code{mate-settings-daemon}.
13989 @deffn {Scheme Procedure} enlightenment-desktop-service-type
13990 Return a service that adds the @code{enlightenment} package to the system
13991 profile, and extends dbus with actions from @code{efl}.
13994 @deftp {Data Type} enlightenment-desktop-service-configuration
13996 @item @code{enlightenment} (default @code{enlightenment})
13997 The enlightenment package to use.
14001 Because the GNOME, XFCE and MATE desktop services pull in so many packages,
14002 the default @code{%desktop-services} variable doesn't include any of
14003 them by default. To add GNOME, XFCE or MATE, just @code{cons} them onto
14004 @code{%desktop-services} in the @code{services} field of your
14005 @code{operating-system}:
14008 (use-modules (gnu))
14009 (use-service-modules desktop)
14012 ;; cons* adds items to the list given as its last argument.
14013 (services (cons* (gnome-desktop-service)
14014 (xfce-desktop-service)
14015 %desktop-services))
14019 These desktop environments will then be available as options in the
14020 graphical login window.
14022 The actual service definitions included in @code{%desktop-services} and
14023 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
14024 are described below.
14026 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
14027 Return a service that runs the ``system bus'', using @var{dbus}, with
14028 support for @var{services}.
14030 @uref{http://dbus.freedesktop.org/, D-Bus} is an inter-process communication
14031 facility. Its system bus is used to allow system services to communicate
14032 and to be notified of system-wide events.
14034 @var{services} must be a list of packages that provide an
14035 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
14036 and policy files. For example, to allow avahi-daemon to use the system bus,
14037 @var{services} must be equal to @code{(list avahi)}.
14040 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
14041 Return a service that runs the @code{elogind} login and
14042 seat management daemon. @uref{https://github.com/elogind/elogind,
14043 Elogind} exposes a D-Bus interface that can be used to know which users
14044 are logged in, know what kind of sessions they have open, suspend the
14045 system, inhibit system suspend, reboot the system, and other tasks.
14047 Elogind handles most system-level power events for a computer, for
14048 example suspending the system when a lid is closed, or shutting it down
14049 when the power button is pressed.
14051 The @var{config} keyword argument specifies the configuration for
14052 elogind, and should be the result of an @code{(elogind-configuration
14053 (@var{parameter} @var{value})...)} invocation. Available parameters and
14054 their default values are:
14057 @item kill-user-processes?
14059 @item kill-only-users
14061 @item kill-exclude-users
14063 @item inhibit-delay-max-seconds
14065 @item handle-power-key
14067 @item handle-suspend-key
14069 @item handle-hibernate-key
14071 @item handle-lid-switch
14073 @item handle-lid-switch-docked
14075 @item power-key-ignore-inhibited?
14077 @item suspend-key-ignore-inhibited?
14079 @item hibernate-key-ignore-inhibited?
14081 @item lid-switch-ignore-inhibited?
14083 @item holdoff-timeout-seconds
14087 @item idle-action-seconds
14089 @item runtime-directory-size-percent
14091 @item runtime-directory-size
14095 @item suspend-state
14096 @code{("mem" "standby" "freeze")}
14099 @item hibernate-state
14101 @item hibernate-mode
14102 @code{("platform" "shutdown")}
14103 @item hybrid-sleep-state
14105 @item hybrid-sleep-mode
14106 @code{("suspend" "platform" "shutdown")}
14110 @deffn {Scheme Procedure} accountsservice-service @
14111 [#:accountsservice @var{accountsservice}]
14112 Return a service that runs AccountsService, a system service that can
14113 list available accounts, change their passwords, and so on.
14114 AccountsService integrates with PolicyKit to enable unprivileged users
14115 to acquire the capability to modify their system configuration.
14116 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
14117 accountsservice web site} for more information.
14119 The @var{accountsservice} keyword argument is the @code{accountsservice}
14120 package to expose as a service.
14123 @deffn {Scheme Procedure} polkit-service @
14124 [#:polkit @var{polkit}]
14125 Return a service that runs the
14126 @uref{http://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
14127 management service}, which allows system administrators to grant access to
14128 privileged operations in a structured way. By querying the Polkit service, a
14129 privileged system component can know when it should grant additional
14130 capabilities to ordinary users. For example, an ordinary user can be granted
14131 the capability to suspend the system if the user is logged in locally.
14134 @deffn {Scheme Procedure} upower-service [#:upower @var{upower}] @
14135 [#:watts-up-pro? #f] @
14136 [#:poll-batteries? #t] @
14137 [#:ignore-lid? #f] @
14138 [#:use-percentage-for-policy? #f] @
14139 [#:percentage-low 10] @
14140 [#:percentage-critical 3] @
14141 [#:percentage-action 2] @
14142 [#:time-low 1200] @
14143 [#:time-critical 300] @
14144 [#:time-action 120] @
14145 [#:critical-power-action 'hybrid-sleep]
14146 Return a service that runs @uref{http://upower.freedesktop.org/,
14147 @command{upowerd}}, a system-wide monitor for power consumption and battery
14148 levels, with the given configuration settings. It implements the
14149 @code{org.freedesktop.UPower} D-Bus interface, and is notably used by
14153 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
14154 Return a service for @uref{http://udisks.freedesktop.org/docs/latest/,
14155 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
14156 notifications and ways to mount/unmount disks. Programs that talk to UDisks
14157 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
14160 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
14161 Return a service that runs @command{colord}, a system service with a D-Bus
14162 interface to manage the color profiles of input and output devices such as
14163 screens and scanners. It is notably used by the GNOME Color Manager graphical
14164 tool. See @uref{http://www.freedesktop.org/software/colord/, the colord web
14165 site} for more information.
14168 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
14169 Return a configuration allowing an application to access GeoClue
14170 location data. @var{name} is the Desktop ID of the application, without
14171 the @code{.desktop} part. If @var{allowed?} is true, the application
14172 will have access to location information by default. The boolean
14173 @var{system?} value indicates whether an application is a system component
14174 or not. Finally @var{users} is a list of UIDs of all users for which
14175 this application is allowed location info access. An empty users list
14176 means that all users are allowed.
14179 @defvr {Scheme Variable} %standard-geoclue-applications
14180 The standard list of well-known GeoClue application configurations,
14181 granting authority to the GNOME date-and-time utility to ask for the
14182 current location in order to set the time zone, and allowing the
14183 IceCat and Epiphany web browsers to request location information.
14184 IceCat and Epiphany both query the user before allowing a web page to
14185 know the user's location.
14188 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
14189 [#:whitelist '()] @
14190 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
14191 [#:submit-data? #f]
14192 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
14193 [#:submission-nick "geoclue"] @
14194 [#:applications %standard-geoclue-applications]
14195 Return a service that runs the GeoClue location service. This service
14196 provides a D-Bus interface to allow applications to request access to a
14197 user's physical location, and optionally to add information to online
14198 location databases. See
14199 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
14200 web site} for more information.
14203 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
14204 [@w{#:auto-enable? #f}]
14205 Return a service that runs the @command{bluetoothd} daemon, which
14206 manages all the Bluetooth devices and provides a number of D-Bus
14207 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
14208 powered automatically at boot, which can be useful when using a
14209 bluetooth keyboard or mouse.
14211 Users need to be in the @code{lp} group to access the D-Bus service.
14214 @node Sound Services
14215 @subsection Sound Services
14217 @cindex sound support
14219 @cindex PulseAudio, sound support
14221 The @code{(gnu services sound)} module provides a service to configure the
14222 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
14223 preferred ALSA output driver.
14225 @deffn {Scheme Variable} alsa-service-type
14226 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
14227 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
14228 configuration file. The value for this type is a @command{alsa-configuration}
14229 record as in this example:
14232 (service alsa-service-type)
14235 See below for details about @code{alsa-configuration}.
14238 @deftp {Data Type} alsa-configuration
14239 Data type representing the configuration for @code{alsa-service}.
14242 @item @code{alsa-plugins} (default: @var{alsa-plugins})
14243 @code{alsa-plugins} package to use.
14245 @item @code{pulseaudio?} (default: @var{#t})
14246 Whether ALSA applications should transparently be made to use the
14247 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
14249 Using PulseAudio allows you to run several sound-producing applications
14250 at the same time and to individual control them @i{via}
14251 @command{pavucontrol}, among other things.
14253 @item @code{extra-options} (default: @var{""})
14254 String to append to the @file{/etc/asound.conf} file.
14259 Individual users who want to override the system configuration of ALSA can do
14260 it with the @file{~/.asoundrc} file:
14263 # In guix, we have to specify the absolute path for plugins.
14265 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
14268 # Routing ALSA to jack:
14269 # <http://jackaudio.org/faq/routing_alsa.html>.
14273 0 system:playback_1
14274 1 system:playback_2
14291 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
14295 @node Database Services
14296 @subsection Database Services
14300 The @code{(gnu services databases)} module provides the following services.
14302 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
14303 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
14304 [#:port 5432] [#:locale ``en_US.utf8'']
14305 Return a service that runs @var{postgresql}, the PostgreSQL database
14308 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
14309 creates a database cluster with @var{locale} as the default
14310 locale, stored in @var{data-directory}. It then listens on @var{port}.
14313 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
14314 Return a service that runs @command{mysqld}, the MySQL or MariaDB
14317 The optional @var{config} argument specifies the configuration for
14318 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
14321 @deftp {Data Type} mysql-configuration
14322 Data type representing the configuration of @var{mysql-service}.
14325 @item @code{mysql} (default: @var{mariadb})
14326 Package object of the MySQL database server, can be either @var{mariadb}
14329 For MySQL, a temporary root password will be displayed at activation time.
14330 For MariaDB, the root password is empty.
14332 @item @code{port} (default: @code{3306})
14333 TCP port on which the database server listens for incoming connections.
14337 @defvr {Scheme Variable} memcached-service-type
14338 This is the service type for the @uref{https://memcached.org/,
14339 Memcached} service, which provides a distributed in memory cache. The
14340 value for the service type is a @code{memcached-configuration} object.
14344 (service memcached-service-type)
14347 @deftp {Data Type} memcached-configuration
14348 Data type representing the configuration of memcached.
14351 @item @code{memcached} (default: @code{memcached})
14352 The Memcached package to use.
14354 @item @code{interfaces} (default: @code{'("0.0.0.0")})
14355 Network interfaces on which to listen.
14357 @item @code{tcp-port} (default: @code{11211})
14358 Port on which to accept connections on,
14360 @item @code{udp-port} (default: @code{11211})
14361 Port on which to accept UDP connections on, a value of 0 will disable
14362 listening on a UDP socket.
14364 @item @code{additional-options} (default: @code{'()})
14365 Additional command line options to pass to @code{memcached}.
14369 @defvr {Scheme Variable} mongodb-service-type
14370 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
14371 The value for the service type is a @code{mongodb-configuration} object.
14375 (service mongodb-service-type)
14378 @deftp {Data Type} mongodb-configuration
14379 Data type representing the configuration of mongodb.
14382 @item @code{mongodb} (default: @code{mongodb})
14383 The MongoDB package to use.
14385 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
14386 The configuration file for MongoDB.
14388 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
14389 This value is used to create the directory, so that it exists and is
14390 owned by the mongodb user. It should match the data-directory which
14391 MongoDB is configured to use through the configuration file.
14395 @defvr {Scheme Variable} redis-service-type
14396 This is the service type for the @uref{https://redis.io/, Redis}
14397 key/value store, whose value is a @code{redis-configuration} object.
14400 @deftp {Data Type} redis-configuration
14401 Data type representing the configuration of redis.
14404 @item @code{redis} (default: @code{redis})
14405 The Redis package to use.
14407 @item @code{bind} (default: @code{"127.0.0.1"})
14408 Network interface on which to listen.
14410 @item @code{port} (default: @code{6379})
14411 Port on which to accept connections on, a value of 0 will disable
14412 listening on a TCP socket.
14414 @item @code{working-directory} (default: @code{"/var/lib/redis"})
14415 Directory in which to store the database and related files.
14419 @node Mail Services
14420 @subsection Mail Services
14424 The @code{(gnu services mail)} module provides Guix service definitions
14425 for email services: IMAP, POP3, and LMTP servers, as well as mail
14426 transport agents (MTAs). Lots of acronyms! These services are detailed
14427 in the subsections below.
14429 @subsubheading Dovecot Service
14431 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
14432 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
14435 By default, Dovecot does not need much configuration; the default
14436 configuration object created by @code{(dovecot-configuration)} will
14437 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
14438 certificate will be generated for TLS-protected connections, though
14439 Dovecot will also listen on cleartext ports by default. There are a
14440 number of options, though, which mail administrators might need to change,
14441 and as is the case with other services, Guix allows the system
14442 administrator to specify these parameters via a uniform Scheme interface.
14444 For example, to specify that mail is located at @code{maildir~/.mail},
14445 one would instantiate the Dovecot service like this:
14448 (dovecot-service #:config
14449 (dovecot-configuration
14450 (mail-location "maildir:~/.mail")))
14453 The available configuration parameters follow. Each parameter
14454 definition is preceded by its type; for example, @samp{string-list foo}
14455 indicates that the @code{foo} parameter should be specified as a list of
14456 strings. There is also a way to specify the configuration as a string,
14457 if you have an old @code{dovecot.conf} file that you want to port over
14458 from some other system; see the end for more details.
14460 @c The following documentation was initially generated by
14461 @c (generate-documentation) in (gnu services mail). Manually maintained
14462 @c documentation is better, so we shouldn't hesitate to edit below as
14463 @c needed. However if the change you want to make to this documentation
14464 @c can be done in an automated way, it's probably easier to change
14465 @c (generate-documentation) than to make it below and have to deal with
14466 @c the churn as dovecot updates.
14468 Available @code{dovecot-configuration} fields are:
14470 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
14471 The dovecot package.
14474 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
14475 A list of IPs or hosts where to listen for connections. @samp{*}
14476 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
14477 interfaces. If you want to specify non-default ports or anything more
14478 complex, customize the address and port fields of the
14479 @samp{inet-listener} of the specific services you are interested in.
14482 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
14483 List of protocols we want to serve. Available protocols include
14484 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
14486 Available @code{protocol-configuration} fields are:
14488 @deftypevr {@code{protocol-configuration} parameter} string name
14489 The name of the protocol.
14492 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
14493 UNIX socket path to the master authentication server to find users.
14494 This is used by imap (for shared users) and lda.
14495 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
14498 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
14499 Space separated list of plugins to load.
14502 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
14503 Maximum number of IMAP connections allowed for a user from each IP
14504 address. NOTE: The username is compared case-sensitively.
14505 Defaults to @samp{10}.
14510 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
14511 List of services to enable. Available services include @samp{imap},
14512 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
14515 Available @code{service-configuration} fields are:
14517 @deftypevr {@code{service-configuration} parameter} string kind
14518 The service kind. Valid values include @code{director},
14519 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
14520 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
14521 @code{tcpwrap}, @code{quota-warning}, or anything else.
14524 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
14525 Listeners for the service. A listener is either a
14526 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
14527 an @code{inet-listener-configuration}.
14528 Defaults to @samp{()}.
14530 Available @code{unix-listener-configuration} fields are:
14532 @deftypevr {@code{unix-listener-configuration} parameter} string path
14533 Path to the file, relative to @code{base-dir} field. This is also used as
14537 @deftypevr {@code{unix-listener-configuration} parameter} string mode
14538 The access mode for the socket.
14539 Defaults to @samp{"0600"}.
14542 @deftypevr {@code{unix-listener-configuration} parameter} string user
14543 The user to own the socket.
14544 Defaults to @samp{""}.
14547 @deftypevr {@code{unix-listener-configuration} parameter} string group
14548 The group to own the socket.
14549 Defaults to @samp{""}.
14553 Available @code{fifo-listener-configuration} fields are:
14555 @deftypevr {@code{fifo-listener-configuration} parameter} string path
14556 Path to the file, relative to @code{base-dir} field. This is also used as
14560 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
14561 The access mode for the socket.
14562 Defaults to @samp{"0600"}.
14565 @deftypevr {@code{fifo-listener-configuration} parameter} string user
14566 The user to own the socket.
14567 Defaults to @samp{""}.
14570 @deftypevr {@code{fifo-listener-configuration} parameter} string group
14571 The group to own the socket.
14572 Defaults to @samp{""}.
14576 Available @code{inet-listener-configuration} fields are:
14578 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
14579 The protocol to listen for.
14582 @deftypevr {@code{inet-listener-configuration} parameter} string address
14583 The address on which to listen, or empty for all addresses.
14584 Defaults to @samp{""}.
14587 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
14588 The port on which to listen.
14591 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
14592 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
14594 Defaults to @samp{#t}.
14599 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
14600 Maximum number of simultaneous client connections per process. Once
14601 this number of connections is received, the next incoming connection
14602 will prompt Dovecot to spawn another process. If set to 0,
14603 @code{default-client-limit} is used instead.
14605 Defaults to @samp{0}.
14609 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
14610 Number of connections to handle before starting a new process.
14611 Typically the only useful values are 0 (unlimited) or 1. 1 is more
14612 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
14613 Defaults to @samp{1}.
14617 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
14618 Maximum number of processes that can exist for this service. If set to
14619 0, @code{default-process-limit} is used instead.
14621 Defaults to @samp{0}.
14625 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
14626 Number of processes to always keep waiting for more connections.
14627 Defaults to @samp{0}.
14630 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
14631 If you set @samp{service-count 0}, you probably need to grow
14633 Defaults to @samp{256000000}.
14638 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
14639 Dict configuration, as created by the @code{dict-configuration}
14642 Available @code{dict-configuration} fields are:
14644 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
14645 A list of key-value pairs that this dict should hold.
14646 Defaults to @samp{()}.
14651 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
14652 A list of passdb configurations, each one created by the
14653 @code{passdb-configuration} constructor.
14655 Available @code{passdb-configuration} fields are:
14657 @deftypevr {@code{passdb-configuration} parameter} string driver
14658 The driver that the passdb should use. Valid values include
14659 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
14661 Defaults to @samp{"pam"}.
14664 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
14665 Space separated list of arguments to the passdb driver.
14666 Defaults to @samp{""}.
14671 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
14672 List of userdb configurations, each one created by the
14673 @code{userdb-configuration} constructor.
14675 Available @code{userdb-configuration} fields are:
14677 @deftypevr {@code{userdb-configuration} parameter} string driver
14678 The driver that the userdb should use. Valid values include
14679 @samp{passwd} and @samp{static}.
14680 Defaults to @samp{"passwd"}.
14683 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
14684 Space separated list of arguments to the userdb driver.
14685 Defaults to @samp{""}.
14688 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
14689 Override fields from passwd.
14690 Defaults to @samp{()}.
14695 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
14696 Plug-in configuration, created by the @code{plugin-configuration}
14700 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
14701 List of namespaces. Each item in the list is created by the
14702 @code{namespace-configuration} constructor.
14704 Available @code{namespace-configuration} fields are:
14706 @deftypevr {@code{namespace-configuration} parameter} string name
14707 Name for this namespace.
14710 @deftypevr {@code{namespace-configuration} parameter} string type
14711 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
14712 Defaults to @samp{"private"}.
14715 @deftypevr {@code{namespace-configuration} parameter} string separator
14716 Hierarchy separator to use. You should use the same separator for
14717 all namespaces or some clients get confused. @samp{/} is usually a good
14718 one. The default however depends on the underlying mail storage
14720 Defaults to @samp{""}.
14723 @deftypevr {@code{namespace-configuration} parameter} string prefix
14724 Prefix required to access this namespace. This needs to be
14725 different for all namespaces. For example @samp{Public/}.
14726 Defaults to @samp{""}.
14729 @deftypevr {@code{namespace-configuration} parameter} string location
14730 Physical location of the mailbox. This is in the same format as
14731 mail_location, which is also the default for it.
14732 Defaults to @samp{""}.
14735 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
14736 There can be only one INBOX, and this setting defines which
14738 Defaults to @samp{#f}.
14741 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
14742 If namespace is hidden, it's not advertised to clients via NAMESPACE
14743 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
14744 useful when converting from another server with different namespaces
14745 which you want to deprecate but still keep working. For example you can
14746 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
14748 Defaults to @samp{#f}.
14751 @deftypevr {@code{namespace-configuration} parameter} boolean list?
14752 Show the mailboxes under this namespace with the LIST command. This
14753 makes the namespace visible for clients that do not support the NAMESPACE
14754 extension. The special @code{children} value lists child mailboxes, but
14755 hides the namespace prefix.
14756 Defaults to @samp{#t}.
14759 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
14760 Namespace handles its own subscriptions. If set to @code{#f}, the
14761 parent namespace handles them. The empty prefix should always have this
14763 Defaults to @samp{#t}.
14766 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
14767 List of predefined mailboxes in this namespace.
14768 Defaults to @samp{()}.
14770 Available @code{mailbox-configuration} fields are:
14772 @deftypevr {@code{mailbox-configuration} parameter} string name
14773 Name for this mailbox.
14776 @deftypevr {@code{mailbox-configuration} parameter} string auto
14777 @samp{create} will automatically create this mailbox.
14778 @samp{subscribe} will both create and subscribe to the mailbox.
14779 Defaults to @samp{"no"}.
14782 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
14783 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
14784 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
14785 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
14786 Defaults to @samp{()}.
14793 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
14794 Base directory where to store runtime data.
14795 Defaults to @samp{"/var/run/dovecot/"}.
14798 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
14799 Greeting message for clients.
14800 Defaults to @samp{"Dovecot ready."}.
14803 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
14804 List of trusted network ranges. Connections from these IPs are
14805 allowed to override their IP addresses and ports (for logging and for
14806 authentication checks). @samp{disable-plaintext-auth} is also ignored
14807 for these networks. Typically you would specify your IMAP proxy servers
14809 Defaults to @samp{()}.
14812 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
14813 List of login access check sockets (e.g.@: tcpwrap).
14814 Defaults to @samp{()}.
14817 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
14818 Show more verbose process titles (in ps). Currently shows user name
14819 and IP address. Useful for seeing who is actually using the IMAP
14820 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
14822 Defaults to @samp{#f}.
14825 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
14826 Should all processes be killed when Dovecot master process shuts down.
14827 Setting this to @code{#f} means that Dovecot can be upgraded without
14828 forcing existing client connections to close (although that could also
14829 be a problem if the upgrade is e.g.@: due to a security fix).
14830 Defaults to @samp{#t}.
14833 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
14834 If non-zero, run mail commands via this many connections to doveadm
14835 server, instead of running them directly in the same process.
14836 Defaults to @samp{0}.
14839 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
14840 UNIX socket or host:port used for connecting to doveadm server.
14841 Defaults to @samp{"doveadm-server"}.
14844 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
14845 List of environment variables that are preserved on Dovecot startup
14846 and passed down to all of its child processes. You can also give
14847 key=value pairs to always set specific settings.
14850 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
14851 Disable LOGIN command and all other plaintext authentications unless
14852 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
14853 matches the local IP (i.e.@: you're connecting from the same computer),
14854 the connection is considered secure and plaintext authentication is
14855 allowed. See also ssl=required setting.
14856 Defaults to @samp{#t}.
14859 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
14860 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
14861 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
14862 for caching to be used.
14863 Defaults to @samp{0}.
14866 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
14867 Time to live for cached data. After TTL expires the cached record
14868 is no longer used, *except* if the main database lookup returns internal
14869 failure. We also try to handle password changes automatically: If
14870 user's previous authentication was successful, but this one wasn't, the
14871 cache isn't used. For now this works only with plaintext
14873 Defaults to @samp{"1 hour"}.
14876 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
14877 TTL for negative hits (user not found, password mismatch).
14878 0 disables caching them completely.
14879 Defaults to @samp{"1 hour"}.
14882 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
14883 List of realms for SASL authentication mechanisms that need them.
14884 You can leave it empty if you don't want to support multiple realms.
14885 Many clients simply use the first one listed here, so keep the default
14887 Defaults to @samp{()}.
14890 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
14891 Default realm/domain to use if none was specified. This is used for
14892 both SASL realms and appending @@domain to username in plaintext
14894 Defaults to @samp{""}.
14897 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
14898 List of allowed characters in username. If the user-given username
14899 contains a character not listed in here, the login automatically fails.
14900 This is just an extra check to make sure user can't exploit any
14901 potential quote escaping vulnerabilities with SQL/LDAP databases. If
14902 you want to allow all characters, set this value to empty.
14903 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
14906 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
14907 Username character translations before it's looked up from
14908 databases. The value contains series of from -> to characters. For
14909 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
14910 translated to @samp{@@}.
14911 Defaults to @samp{""}.
14914 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
14915 Username formatting before it's looked up from databases. You can
14916 use the standard variables here, e.g.@: %Lu would lowercase the username,
14917 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
14918 change the @samp{@@} into @samp{-AT-}. This translation is done after
14919 @samp{auth-username-translation} changes.
14920 Defaults to @samp{"%Lu"}.
14923 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
14924 If you want to allow master users to log in by specifying the master
14925 username within the normal username string (i.e.@: not using SASL
14926 mechanism's support for it), you can specify the separator character
14927 here. The format is then <username><separator><master username>.
14928 UW-IMAP uses @samp{*} as the separator, so that could be a good
14930 Defaults to @samp{""}.
14933 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
14934 Username to use for users logging in with ANONYMOUS SASL
14936 Defaults to @samp{"anonymous"}.
14939 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
14940 Maximum number of dovecot-auth worker processes. They're used to
14941 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
14942 They're automatically created and destroyed as needed.
14943 Defaults to @samp{30}.
14946 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
14947 Host name to use in GSSAPI principal names. The default is to use
14948 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
14949 allow all keytab entries.
14950 Defaults to @samp{""}.
14953 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
14954 Kerberos keytab to use for the GSSAPI mechanism. Will use the
14955 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
14956 need to change the auth service to run as root to be able to read this
14958 Defaults to @samp{""}.
14961 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
14962 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
14963 and @samp{ntlm-auth} helper.
14964 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
14965 Defaults to @samp{#f}.
14968 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
14969 Path for Samba's @samp{ntlm-auth} helper binary.
14970 Defaults to @samp{"/usr/bin/ntlm_auth"}.
14973 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
14974 Time to delay before replying to failed authentications.
14975 Defaults to @samp{"2 secs"}.
14978 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
14979 Require a valid SSL client certificate or the authentication
14981 Defaults to @samp{#f}.
14984 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
14985 Take the username from client's SSL certificate, using
14986 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
14988 Defaults to @samp{#f}.
14991 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
14992 List of wanted authentication mechanisms. Supported mechanisms are:
14993 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
14994 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
14995 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
14996 @samp{disable-plaintext-auth} setting.
14999 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
15000 List of IPs or hostnames to all director servers, including ourself.
15001 Ports can be specified as ip:port. The default port is the same as what
15002 director service's @samp{inet-listener} is using.
15003 Defaults to @samp{()}.
15006 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
15007 List of IPs or hostnames to all backend mail servers. Ranges are
15008 allowed too, like 10.0.0.10-10.0.0.30.
15009 Defaults to @samp{()}.
15012 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
15013 How long to redirect users to a specific server after it no longer
15014 has any connections.
15015 Defaults to @samp{"15 min"}.
15018 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
15019 How the username is translated before being hashed. Useful values
15020 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
15021 are shared within domain.
15022 Defaults to @samp{"%Lu"}.
15025 @deftypevr {@code{dovecot-configuration} parameter} string log-path
15026 Log file to use for error messages. @samp{syslog} logs to syslog,
15027 @samp{/dev/stderr} logs to stderr.
15028 Defaults to @samp{"syslog"}.
15031 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
15032 Log file to use for informational messages. Defaults to
15034 Defaults to @samp{""}.
15037 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
15038 Log file to use for debug messages. Defaults to
15039 @samp{info-log-path}.
15040 Defaults to @samp{""}.
15043 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
15044 Syslog facility to use if you're logging to syslog. Usually if you
15045 don't want to use @samp{mail}, you'll use local0..local7. Also other
15046 standard facilities are supported.
15047 Defaults to @samp{"mail"}.
15050 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
15051 Log unsuccessful authentication attempts and the reasons why they
15053 Defaults to @samp{#f}.
15056 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose-passwords?
15057 In case of password mismatches, log the attempted password. Valid
15058 values are no, plain and sha1. sha1 can be useful for detecting brute
15059 force password attempts vs. user simply trying the same password over
15060 and over again. You can also truncate the value to n chars by appending
15061 ":n" (e.g.@: sha1:6).
15062 Defaults to @samp{#f}.
15065 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
15066 Even more verbose logging for debugging purposes. Shows for example
15068 Defaults to @samp{#f}.
15071 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
15072 In case of password mismatches, log the passwords and used scheme so
15073 the problem can be debugged. Enabling this also enables
15075 Defaults to @samp{#f}.
15078 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
15079 Enable mail process debugging. This can help you figure out why
15080 Dovecot isn't finding your mails.
15081 Defaults to @samp{#f}.
15084 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
15085 Show protocol level SSL errors.
15086 Defaults to @samp{#f}.
15089 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
15090 Prefix for each line written to log file. % codes are in
15091 strftime(3) format.
15092 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
15095 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
15096 List of elements we want to log. The elements which have a
15097 non-empty variable value are joined together to form a comma-separated
15101 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
15102 Login log format. %s contains @samp{login-log-format-elements}
15103 string, %$ contains the data we want to log.
15104 Defaults to @samp{"%$: %s"}.
15107 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
15108 Log prefix for mail processes. See doc/wiki/Variables.txt for list
15109 of possible variables you can use.
15110 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
15113 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
15114 Format to use for logging mail deliveries. You can use variables:
15117 Delivery status message (e.g.@: @samp{saved to INBOX})
15129 Defaults to @samp{"msgid=%m: %$"}.
15132 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
15133 Location for users' mailboxes. The default is empty, which means
15134 that Dovecot tries to find the mailboxes automatically. This won't work
15135 if the user doesn't yet have any mail, so you should explicitly tell
15136 Dovecot the full location.
15138 If you're using mbox, giving a path to the INBOX
15139 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
15140 where the other mailboxes are kept. This is called the "root mail
15141 directory", and it must be the first path given in the
15142 @samp{mail-location} setting.
15144 There are a few special variables you can use, eg.:
15150 user part in user@@domain, same as %u if there's no domain
15152 domain part in user@@domain, empty if there's no domain
15157 See doc/wiki/Variables.txt for full list. Some examples:
15159 @item maildir:~/Maildir
15160 @item mbox:~/mail:INBOX=/var/mail/%u
15161 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
15163 Defaults to @samp{""}.
15166 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
15167 System user and group used to access mails. If you use multiple,
15168 userdb can override these by returning uid or gid fields. You can use
15169 either numbers or names. <doc/wiki/UserIds.txt>.
15170 Defaults to @samp{""}.
15173 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
15175 Defaults to @samp{""}.
15178 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
15179 Group to enable temporarily for privileged operations. Currently
15180 this is used only with INBOX when either its initial creation or
15181 dotlocking fails. Typically this is set to "mail" to give access to
15183 Defaults to @samp{""}.
15186 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
15187 Grant access to these supplementary groups for mail processes.
15188 Typically these are used to set up access to shared mailboxes. Note
15189 that it may be dangerous to set these if users can create
15190 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
15191 could allow a user to delete others' mailboxes, or ln -s
15192 /secret/shared/box ~/mail/mybox would allow reading it).
15193 Defaults to @samp{""}.
15196 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
15197 Allow full file system access to clients. There's no access checks
15198 other than what the operating system does for the active UID/GID. It
15199 works with both maildir and mboxes, allowing you to prefix mailboxes
15200 names with e.g.@: /path/ or ~user/.
15201 Defaults to @samp{#f}.
15204 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
15205 Don't use mmap() at all. This is required if you store indexes to
15206 shared file systems (NFS or clustered file system).
15207 Defaults to @samp{#f}.
15210 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
15211 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
15212 supports @samp{O_EXCL} since version 3, so this should be safe to use
15213 nowadays by default.
15214 Defaults to @samp{#t}.
15217 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
15218 When to use fsync() or fdatasync() calls:
15221 Whenever necessary to avoid losing important data
15223 Useful with e.g.@: NFS when write()s are delayed
15225 Never use it (best performance, but crashes can lose data).
15227 Defaults to @samp{"optimized"}.
15230 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
15231 Mail storage exists in NFS. Set this to yes to make Dovecot flush
15232 NFS caches whenever needed. If you're using only a single mail server
15234 Defaults to @samp{#f}.
15237 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
15238 Mail index files also exist in NFS. Setting this to yes requires
15239 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
15240 Defaults to @samp{#f}.
15243 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
15244 Locking method for index files. Alternatives are fcntl, flock and
15245 dotlock. Dotlocking uses some tricks which may create more disk I/O
15246 than other locking methods. NFS users: flock doesn't work, remember to
15247 change @samp{mmap-disable}.
15248 Defaults to @samp{"fcntl"}.
15251 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
15252 Directory in which LDA/LMTP temporarily stores incoming mails >128
15254 Defaults to @samp{"/tmp"}.
15257 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
15258 Valid UID range for users. This is mostly to make sure that users can't
15259 log in as daemons or other system users. Note that denying root logins is
15260 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
15262 Defaults to @samp{500}.
15265 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
15267 Defaults to @samp{0}.
15270 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
15271 Valid GID range for users. Users having non-valid GID as primary group ID
15272 aren't allowed to log in. If user belongs to supplementary groups with
15273 non-valid GIDs, those groups are not set.
15274 Defaults to @samp{1}.
15277 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
15279 Defaults to @samp{0}.
15282 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
15283 Maximum allowed length for mail keyword name. It's only forced when
15284 trying to create new keywords.
15285 Defaults to @samp{50}.
15288 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
15289 List of directories under which chrooting is allowed for mail
15290 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
15291 too). This setting doesn't affect @samp{login-chroot}
15292 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
15293 "/./" in home dirs are ignored. WARNING: Never add directories here
15294 which local users can modify, that may lead to root exploit. Usually
15295 this should be done only if you don't allow shell access for users.
15296 <doc/wiki/Chrooting.txt>.
15297 Defaults to @samp{()}.
15300 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
15301 Default chroot directory for mail processes. This can be overridden
15302 for specific users in user database by giving /./ in user's home
15303 directory (e.g.@: /home/./user chroots into /home). Note that usually
15304 there is no real need to do chrooting, Dovecot doesn't allow users to
15305 access files outside their mail directory anyway. If your home
15306 directories are prefixed with the chroot directory, append "/."@: to
15307 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
15308 Defaults to @samp{""}.
15311 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
15312 UNIX socket path to master authentication server to find users.
15313 This is used by imap (for shared users) and lda.
15314 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
15317 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
15318 Directory where to look up mail plugins.
15319 Defaults to @samp{"/usr/lib/dovecot"}.
15322 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
15323 List of plugins to load for all services. Plugins specific to IMAP,
15324 LDA, etc.@: are added to this list in their own .conf files.
15325 Defaults to @samp{()}.
15328 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
15329 The minimum number of mails in a mailbox before updates are done to
15330 cache file. This allows optimizing Dovecot's behavior to do less disk
15331 writes at the cost of more disk reads.
15332 Defaults to @samp{0}.
15335 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
15336 When IDLE command is running, mailbox is checked once in a while to
15337 see if there are any new mails or other changes. This setting defines
15338 the minimum time to wait between those checks. Dovecot can also use
15339 dnotify, inotify and kqueue to find out immediately when changes
15341 Defaults to @samp{"30 secs"}.
15344 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
15345 Save mails with CR+LF instead of plain LF. This makes sending those
15346 mails take less CPU, especially with sendfile() syscall with Linux and
15347 FreeBSD. But it also creates a bit more disk I/O which may just make it
15348 slower. Also note that if other software reads the mboxes/maildirs,
15349 they may handle the extra CRs wrong and cause problems.
15350 Defaults to @samp{#f}.
15353 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
15354 By default LIST command returns all entries in maildir beginning
15355 with a dot. Enabling this option makes Dovecot return only entries
15356 which are directories. This is done by stat()ing each entry, so it
15357 causes more disk I/O.
15358 (For systems setting struct @samp{dirent->d_type} this check is free
15359 and it's done always regardless of this setting).
15360 Defaults to @samp{#f}.
15363 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
15364 When copying a message, do it with hard links whenever possible.
15365 This makes the performance much better, and it's unlikely to have any
15367 Defaults to @samp{#t}.
15370 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
15371 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
15372 directory only when its mtime changes unexpectedly or when we can't find
15373 the mail otherwise.
15374 Defaults to @samp{#f}.
15377 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
15378 Which locking methods to use for locking mbox. There are four
15383 Create <mailbox>.lock file. This is the oldest and most NFS-safe
15384 solution. If you want to use /var/mail/ like directory, the users will
15385 need write access to that directory.
15387 Same as dotlock, but if it fails because of permissions or because there
15388 isn't enough disk space, just skip it.
15390 Use this if possible. Works with NFS too if lockd is used.
15392 May not exist in all systems. Doesn't work with NFS.
15394 May not exist in all systems. Doesn't work with NFS.
15397 You can use multiple locking methods; if you do the order they're declared
15398 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
15399 locking methods as well. Some operating systems don't allow using some of
15400 them simultaneously.
15403 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
15407 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
15408 Maximum time to wait for lock (all of them) before aborting.
15409 Defaults to @samp{"5 mins"}.
15412 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
15413 If dotlock exists but the mailbox isn't modified in any way,
15414 override the lock file after this much time.
15415 Defaults to @samp{"2 mins"}.
15418 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
15419 When mbox changes unexpectedly we have to fully read it to find out
15420 what changed. If the mbox is large this can take a long time. Since
15421 the change is usually just a newly appended mail, it'd be faster to
15422 simply read the new mails. If this setting is enabled, Dovecot does
15423 this but still safely fallbacks to re-reading the whole mbox file
15424 whenever something in mbox isn't how it's expected to be. The only real
15425 downside to this setting is that if some other MUA changes message
15426 flags, Dovecot doesn't notice it immediately. Note that a full sync is
15427 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
15428 Defaults to @samp{#t}.
15431 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
15432 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
15433 EXAMINE, EXPUNGE or CHECK commands. If this is set,
15434 @samp{mbox-dirty-syncs} is ignored.
15435 Defaults to @samp{#f}.
15438 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
15439 Delay writing mbox headers until doing a full write sync (EXPUNGE
15440 and CHECK commands and when closing the mailbox). This is especially
15441 useful for POP3 where clients often delete all mails. The downside is
15442 that our changes aren't immediately visible to other MUAs.
15443 Defaults to @samp{#t}.
15446 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
15447 If mbox size is smaller than this (e.g.@: 100k), don't write index
15448 files. If an index file already exists it's still read, just not
15450 Defaults to @samp{0}.
15453 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
15454 Maximum dbox file size until it's rotated.
15455 Defaults to @samp{10000000}.
15458 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
15459 Maximum dbox file age until it's rotated. Typically in days. Day
15460 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
15462 Defaults to @samp{"1d"}.
15465 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
15466 When creating new mdbox files, immediately preallocate their size to
15467 @samp{mdbox-rotate-size}. This setting currently works only in Linux
15468 with some file systems (ext4, xfs).
15469 Defaults to @samp{#f}.
15472 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
15473 sdbox and mdbox support saving mail attachments to external files,
15474 which also allows single instance storage for them. Other backends
15475 don't support this for now.
15477 WARNING: This feature hasn't been tested much yet. Use at your own risk.
15479 Directory root where to store mail attachments. Disabled, if empty.
15480 Defaults to @samp{""}.
15483 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
15484 Attachments smaller than this aren't saved externally. It's also
15485 possible to write a plugin to disable saving specific attachments
15487 Defaults to @samp{128000}.
15490 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
15491 File system backend to use for saving attachments:
15494 No SiS done by Dovecot (but this might help FS's own deduplication)
15496 SiS with immediate byte-by-byte comparison during saving
15497 @item sis-queue posix
15498 SiS with delayed comparison and deduplication.
15500 Defaults to @samp{"sis posix"}.
15503 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
15504 Hash format to use in attachment filenames. You can add any text and
15505 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
15506 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
15507 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
15508 Defaults to @samp{"%@{sha1@}"}.
15511 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
15513 Defaults to @samp{100}.
15516 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
15518 Defaults to @samp{1000}.
15521 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
15522 Default VSZ (virtual memory size) limit for service processes.
15523 This is mainly intended to catch and kill processes that leak memory
15524 before they eat up everything.
15525 Defaults to @samp{256000000}.
15528 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
15529 Login user is internally used by login processes. This is the most
15530 untrusted user in Dovecot system. It shouldn't have access to anything
15532 Defaults to @samp{"dovenull"}.
15535 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
15536 Internal user is used by unprivileged processes. It should be
15537 separate from login user, so that login processes can't disturb other
15539 Defaults to @samp{"dovecot"}.
15542 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
15543 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
15544 Defaults to @samp{"required"}.
15547 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
15548 PEM encoded X.509 SSL/TLS certificate (public key).
15549 Defaults to @samp{"</etc/dovecot/default.pem"}.
15552 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
15553 PEM encoded SSL/TLS private key. The key is opened before
15554 dropping root privileges, so keep the key file unreadable by anyone but
15556 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
15559 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
15560 If key file is password protected, give the password here.
15561 Alternatively give it when starting dovecot with -p parameter. Since
15562 this file is often world-readable, you may want to place this setting
15563 instead to a different.
15564 Defaults to @samp{""}.
15567 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
15568 PEM encoded trusted certificate authority. Set this only if you
15569 intend to use @samp{ssl-verify-client-cert? #t}. The file should
15570 contain the CA certificate(s) followed by the matching
15571 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
15572 Defaults to @samp{""}.
15575 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
15576 Require that CRL check succeeds for client certificates.
15577 Defaults to @samp{#t}.
15580 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
15581 Request client to send a certificate. If you also want to require
15582 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
15583 Defaults to @samp{#f}.
15586 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
15587 Which field from certificate to use for username. commonName and
15588 x500UniqueIdentifier are the usual choices. You'll also need to set
15589 @samp{auth-ssl-username-from-cert? #t}.
15590 Defaults to @samp{"commonName"}.
15593 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
15594 Minimum SSL protocol version to accept.
15595 Defaults to @samp{"TLSv1"}.
15598 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
15599 SSL ciphers to use.
15600 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
15603 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
15604 SSL crypto device to use, for valid values run "openssl engine".
15605 Defaults to @samp{""}.
15608 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
15609 Address to use when sending rejection mails.
15610 %d expands to recipient domain.
15611 Defaults to @samp{"postmaster@@%d"}.
15614 @deftypevr {@code{dovecot-configuration} parameter} string hostname
15615 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
15616 and in LMTP replies. Default is the system's real hostname@@domain.
15617 Defaults to @samp{""}.
15620 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
15621 If user is over quota, return with temporary failure instead of
15623 Defaults to @samp{#f}.
15626 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
15627 Binary to use for sending mails.
15628 Defaults to @samp{"/usr/sbin/sendmail"}.
15631 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
15632 If non-empty, send mails via this SMTP host[:port] instead of
15634 Defaults to @samp{""}.
15637 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
15638 Subject: header to use for rejection mails. You can use the same
15639 variables as for @samp{rejection-reason} below.
15640 Defaults to @samp{"Rejected: %s"}.
15643 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
15644 Human readable error message for rejection mails. You can use
15657 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
15660 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
15661 Delimiter character between local-part and detail in email
15663 Defaults to @samp{"+"}.
15666 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
15667 Header where the original recipient address (SMTP's RCPT TO:
15668 address) is taken from if not available elsewhere. With dovecot-lda -a
15669 parameter overrides this. A commonly used header for this is
15671 Defaults to @samp{""}.
15674 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
15675 Should saving a mail to a nonexistent mailbox automatically create
15677 Defaults to @samp{#f}.
15680 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
15681 Should automatically created mailboxes be also automatically
15683 Defaults to @samp{#f}.
15686 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
15687 Maximum IMAP command line length. Some clients generate very long
15688 command lines with huge mailboxes, so you may need to raise this if you
15689 get "Too long argument" or "IMAP command line too large" errors
15691 Defaults to @samp{64000}.
15694 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
15695 IMAP logout format string:
15698 total number of bytes read from client
15700 total number of bytes sent to client.
15702 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
15703 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@}"}.
15706 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
15707 Override the IMAP CAPABILITY response. If the value begins with '+',
15708 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
15709 Defaults to @samp{""}.
15712 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
15713 How long to wait between "OK Still here" notifications when client
15715 Defaults to @samp{"2 mins"}.
15718 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
15719 ID field names and values to send to clients. Using * as the value
15720 makes Dovecot use the default value. The following fields have default
15721 values currently: name, version, os, os-version, support-url,
15723 Defaults to @samp{""}.
15726 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
15727 ID fields sent by client to log. * means everything.
15728 Defaults to @samp{""}.
15731 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
15732 Workarounds for various client bugs:
15735 @item delay-newmail
15736 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
15737 CHECK commands. Some clients ignore them otherwise, for example OSX
15738 Mail (<v2.1). Outlook Express breaks more badly though, without this it
15739 may show user "Message no longer in server" errors. Note that OE6
15740 still breaks even with this workaround if synchronization is set to
15743 @item tb-extra-mailbox-sep
15744 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
15745 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
15746 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
15748 @item tb-lsub-flags
15749 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
15750 This makes Thunderbird realize they aren't selectable and show them
15751 greyed out, instead of only later giving "not selectable" popup error.
15753 Defaults to @samp{()}.
15756 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
15757 Host allowed in URLAUTH URLs sent by client. "*" allows all.
15758 Defaults to @samp{""}.
15762 Whew! Lots of configuration options. The nice thing about it though is
15763 that GuixSD has a complete interface to Dovecot's configuration
15764 language. This allows not only a nice way to declare configurations,
15765 but also offers reflective capabilities as well: users can write code to
15766 inspect and transform configurations from within Scheme.
15768 However, it could be that you just want to get a @code{dovecot.conf} up
15769 and running. In that case, you can pass an
15770 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
15771 @code{dovecot-service}. As its name indicates, an opaque configuration
15772 does not have easy reflective capabilities.
15774 Available @code{opaque-dovecot-configuration} fields are:
15776 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
15777 The dovecot package.
15780 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
15781 The contents of the @code{dovecot.conf}, as a string.
15784 For example, if your @code{dovecot.conf} is just the empty string, you
15785 could instantiate a dovecot service like this:
15788 (dovecot-service #:config
15789 (opaque-dovecot-configuration
15793 @subsubheading OpenSMTPD Service
15795 @deffn {Scheme Variable} opensmtpd-service-type
15796 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
15797 service, whose value should be an @code{opensmtpd-configuration} object
15798 as in this example:
15801 (service opensmtpd-service-type
15802 (opensmtpd-configuration
15803 (config-file (local-file "./my-smtpd.conf"))))
15807 @deftp {Data Type} opensmtpd-configuration
15808 Data type representing the configuration of opensmtpd.
15811 @item @code{package} (default: @var{opensmtpd})
15812 Package object of the OpenSMTPD SMTP server.
15814 @item @code{config-file} (default: @var{%default-opensmtpd-file})
15815 File-like object of the OpenSMTPD configuration file to use. By default
15816 it listens on the loopback network interface, and allows for mail from
15817 users and daemons on the local machine, as well as permitting email to
15818 remote servers. Run @command{man smtpd.conf} for more information.
15823 @subsubheading Exim Service
15825 @cindex mail transfer agent (MTA)
15826 @cindex MTA (mail transfer agent)
15829 @deffn {Scheme Variable} exim-service-type
15830 This is the type of the @uref{https://exim.org, Exim} mail transfer
15831 agent (MTA), whose value should be an @code{exim-configuration} object
15832 as in this example:
15835 (service exim-service-type
15836 (exim-configuration
15837 (config-file (local-file "./my-exim.conf"))))
15841 In order to use an @code{exim-service-type} service you must also have a
15842 @code{mail-aliases-service-type} service present in your
15843 @code{operating-system} (even if it has no aliases).
15845 @deftp {Data Type} exim-configuration
15846 Data type representing the configuration of exim.
15849 @item @code{package} (default: @var{exim})
15850 Package object of the Exim server.
15852 @item @code{config-file} (default: @code{#f})
15853 File-like object of the Exim configuration file to use. If its value is
15854 @code{#f} then use the default configuration file from the package
15855 provided in @code{package}. The resulting configuration file is loaded
15856 after setting the @code{exim_user} and @code{exim_group} configuration
15862 @subsubheading Mail Aliases Service
15864 @cindex email aliases
15865 @cindex aliases, for email addresses
15867 @deffn {Scheme Variable} mail-aliases-service-type
15868 This is the type of the service which provides @code{/etc/aliases},
15869 specifying how to deliver mail to users on this system.
15872 (service mail-aliases-service-type
15873 '(("postmaster" "bob")
15874 ("bob" "bob@@example.com" "bob@@example2.com")))
15878 The configuration for a @code{mail-aliases-service-type} service is an
15879 association list denoting how to deliver mail that comes to this
15880 system. Each entry is of the form @code{(alias addresses ...)}, with
15881 @code{alias} specifying the local alias and @code{addresses} specifying
15882 where to deliver this user's mail.
15884 The aliases aren't required to exist as users on the local system. In
15885 the above example, there doesn't need to be a @code{postmaster} entry in
15886 the @code{operating-system}'s @code{user-accounts} in order to deliver
15887 the @code{postmaster} mail to @code{bob} (which subsequently would
15888 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
15890 @node Messaging Services
15891 @subsection Messaging Services
15896 The @code{(gnu services messaging)} module provides Guix service
15897 definitions for messaging services: currently only Prosody is supported.
15899 @subsubheading Prosody Service
15901 @deffn {Scheme Variable} prosody-service-type
15902 This is the type for the @uref{https://prosody.im, Prosody XMPP
15903 communication server}. Its value must be a @code{prosody-configuration}
15904 record as in this example:
15907 (service prosody-service-type
15908 (prosody-configuration
15909 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
15912 (int-component-configuration
15913 (hostname "conference.example.net")
15915 (mod-muc (mod-muc-configuration)))))
15918 (virtualhost-configuration
15919 (domain "example.net"))))))
15922 See below for details about @code{prosody-configuration}.
15926 By default, Prosody does not need much configuration. Only one
15927 @code{virtualhosts} field is needed: it specifies the domain you wish
15930 You can perform various sanity checks on the generated configuration
15931 with the @code{prosodyctl check} command.
15933 Prosodyctl will also help you to import certificates from the
15934 @code{letsencrypt} directory so that the @code{prosody} user can access
15935 them. See @url{https://prosody.im/doc/letsencrypt}.
15938 prosodyctl --root cert import /etc/letsencrypt/live
15941 The available configuration parameters follow. Each parameter
15942 definition is preceded by its type; for example, @samp{string-list foo}
15943 indicates that the @code{foo} parameter should be specified as a list of
15944 strings. Types starting with @code{maybe-} denote parameters that won't
15945 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
15947 There is also a way to specify the configuration as a string, if you
15948 have an old @code{prosody.cfg.lua} file that you want to port over from
15949 some other system; see the end for more details.
15951 The @code{file-object} type designates either a file-like object
15952 (@pxref{G-Expressions, file-like objects}) or a file name.
15954 @c The following documentation was initially generated by
15955 @c (generate-documentation) in (gnu services messaging). Manually maintained
15956 @c documentation is better, so we shouldn't hesitate to edit below as
15957 @c needed. However if the change you want to make to this documentation
15958 @c can be done in an automated way, it's probably easier to change
15959 @c (generate-documentation) than to make it below and have to deal with
15960 @c the churn as Prosody updates.
15962 Available @code{prosody-configuration} fields are:
15964 @deftypevr {@code{prosody-configuration} parameter} package prosody
15965 The Prosody package.
15968 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
15969 Location of the Prosody data storage directory. See
15970 @url{https://prosody.im/doc/configure}.
15971 Defaults to @samp{"/var/lib/prosody"}.
15974 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
15975 Additional plugin directories. They are searched in all the specified
15976 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
15977 Defaults to @samp{()}.
15980 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
15981 Every virtual host and component needs a certificate so that clients and
15982 servers can securely verify its identity. Prosody will automatically load
15983 certificates/keys from the directory specified here.
15984 Defaults to @samp{"/etc/prosody/certs"}.
15987 @deftypevr {@code{prosody-configuration} parameter} string-list admins
15988 This is a list of accounts that are admins for the server. Note that you
15989 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
15990 @url{https://prosody.im/doc/creating_accounts}.
15991 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
15992 Defaults to @samp{()}.
15995 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
15996 Enable use of libevent for better performance under high load. See
15997 @url{https://prosody.im/doc/libevent}.
15998 Defaults to @samp{#f}.
16001 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
16002 This is the list of modules Prosody will load on startup. It looks for
16003 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
16004 Documentation on modules can be found at:
16005 @url{https://prosody.im/doc/modules}.
16006 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
16009 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
16010 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
16011 should you want to disable them then add them to this list.
16012 Defaults to @samp{()}.
16015 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
16016 Path to a text file where the shared groups are defined. If this path is
16017 empty then @samp{mod_groups} does nothing. See
16018 @url{https://prosody.im/doc/modules/mod_groups}.
16019 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
16022 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
16023 Disable account creation by default, for security. See
16024 @url{https://prosody.im/doc/creating_accounts}.
16025 Defaults to @samp{#f}.
16028 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
16029 These are the SSL/TLS-related settings. Most of them are disabled so to
16030 use Prosody's defaults. If you do not completely understand these options, do
16031 not add them to your config, it is easy to lower the security of your server
16032 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
16034 Available @code{ssl-configuration} fields are:
16036 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
16037 This determines what handshake to use.
16040 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
16041 Path to your private key file.
16044 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
16045 Path to your certificate file.
16048 @deftypevr {@code{ssl-configuration} parameter} file-object capath
16049 Path to directory containing root certificates that you wish Prosody to
16050 trust when verifying the certificates of remote servers.
16051 Defaults to @samp{"/etc/ssl/certs"}.
16054 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
16055 Path to a file containing root certificates that you wish Prosody to trust.
16056 Similar to @code{capath} but with all certificates concatenated together.
16059 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
16060 A list of verification options (these mostly map to OpenSSL's
16061 @code{set_verify()} flags).
16064 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
16065 A list of general options relating to SSL/TLS. These map to OpenSSL's
16066 @code{set_options()}. For a full list of options available in LuaSec, see the
16070 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
16071 How long a chain of certificate authorities to check when looking for a
16072 trusted root certificate.
16075 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
16076 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
16077 clients, and in what order.
16080 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
16081 A path to a file containing parameters for Diffie-Hellman key exchange. You
16082 can create such a file with:
16083 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
16086 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
16087 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
16088 @samp{"secp384r1"}.
16091 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
16092 A list of "extra" verification options.
16095 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
16096 Password for encrypted private keys.
16101 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
16102 Whether to force all client-to-server connections to be encrypted or not.
16103 See @url{https://prosody.im/doc/modules/mod_tls}.
16104 Defaults to @samp{#f}.
16107 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
16108 Set of mechanisms that will never be offered. See
16109 @url{https://prosody.im/doc/modules/mod_saslauth}.
16110 Defaults to @samp{("DIGEST-MD5")}.
16113 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
16114 Whether to force all server-to-server connections to be encrypted or not.
16115 See @url{https://prosody.im/doc/modules/mod_tls}.
16116 Defaults to @samp{#f}.
16119 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
16120 Whether to require encryption and certificate authentication. This
16121 provides ideal security, but requires servers you communicate with to support
16122 encryption AND present valid, trusted certificates. See
16123 @url{https://prosody.im/doc/s2s#security}.
16124 Defaults to @samp{#f}.
16127 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
16128 Many servers don't support encryption or have invalid or self-signed
16129 certificates. You can list domains here that will not be required to
16130 authenticate using certificates. They will be authenticated using DNS. See
16131 @url{https://prosody.im/doc/s2s#security}.
16132 Defaults to @samp{()}.
16135 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
16136 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
16137 valid certificates for some domains by specifying a list here. See
16138 @url{https://prosody.im/doc/s2s#security}.
16139 Defaults to @samp{()}.
16142 @deftypevr {@code{prosody-configuration} parameter} string authentication
16143 Select the authentication backend to use. The default provider stores
16144 passwords in plaintext and uses Prosody's configured data storage to store the
16145 authentication data. If you do not trust your server please see
16146 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
16147 about using the hashed backend. See also
16148 @url{https://prosody.im/doc/authentication}
16149 Defaults to @samp{"internal_plain"}.
16152 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
16153 Set logging options. Advanced logging configuration is not yet supported
16154 by the GuixSD Prosody Service. See @url{https://prosody.im/doc/logging}.
16155 Defaults to @samp{"*syslog"}.
16158 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
16159 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
16160 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
16163 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
16164 Maximum allowed size of the HTTP body (in bytes).
16167 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
16168 Some modules expose their own URL in various ways. This URL is built
16169 from the protocol, host and port used. If Prosody sits behind a proxy, the
16170 public URL will be @code{http-external-url} instead. See
16171 @url{https://prosody.im/doc/http#external_url}.
16174 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
16175 A host in Prosody is a domain on which user accounts can be created. For
16176 example if you want your users to have addresses like
16177 @samp{"john.smith@@example.com"} then you need to add a host
16178 @samp{"example.com"}. All options in this list will apply only to this host.
16180 Note: the name "virtual" host is used in configuration to avoid confusion with
16181 the actual physical host that Prosody is installed on. A single Prosody
16182 instance can serve many domains, each one defined as a VirtualHost entry in
16183 Prosody's configuration. Conversely a server that hosts a single domain would
16184 have just one VirtualHost entry.
16186 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
16188 Available @code{virtualhost-configuration} fields are:
16190 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:
16191 @deftypevr {@code{virtualhost-configuration} parameter} string domain
16192 Domain you wish Prosody to serve.
16197 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
16198 Components are extra services on a server which are available to clients,
16199 usually on a subdomain of the main server (such as
16200 @samp{"mycomponent.example.com"}). Example components might be chatroom
16201 servers, user directories, or gateways to other protocols.
16203 Internal components are implemented with Prosody-specific plugins. To add an
16204 internal component, you simply fill the hostname field, and the plugin you wish
16205 to use for the component.
16207 See @url{https://prosody.im/doc/components}.
16208 Defaults to @samp{()}.
16210 Available @code{int-component-configuration} fields are:
16212 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:
16213 @deftypevr {@code{int-component-configuration} parameter} string hostname
16214 Hostname of the component.
16217 @deftypevr {@code{int-component-configuration} parameter} string plugin
16218 Plugin you wish to use for the component.
16221 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
16222 Multi-user chat (MUC) is Prosody's module for allowing you to create
16223 hosted chatrooms/conferences for XMPP users.
16225 General information on setting up and using multi-user chatrooms can be found
16226 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
16227 which you should read if you are new to XMPP chatrooms.
16229 See also @url{https://prosody.im/doc/modules/mod_muc}.
16231 Available @code{mod-muc-configuration} fields are:
16233 @deftypevr {@code{mod-muc-configuration} parameter} string name
16234 The name to return in service discovery responses.
16235 Defaults to @samp{"Prosody Chatrooms"}.
16238 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
16239 If @samp{#t}, this will only allow admins to create new chatrooms.
16240 Otherwise anyone can create a room. The value @samp{"local"} restricts room
16241 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
16242 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
16243 restricts to service administrators only.
16244 Defaults to @samp{#f}.
16247 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
16248 Maximum number of history messages that will be sent to the member that has
16249 just joined the room.
16250 Defaults to @samp{20}.
16257 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
16258 External components use XEP-0114, which most standalone components
16259 support. To add an external component, you simply fill the hostname field. See
16260 @url{https://prosody.im/doc/components}.
16261 Defaults to @samp{()}.
16263 Available @code{ext-component-configuration} fields are:
16265 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:
16266 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
16267 Password which the component will use to log in.
16270 @deftypevr {@code{ext-component-configuration} parameter} string hostname
16271 Hostname of the component.
16276 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
16277 Port(s) Prosody listens on for component connections.
16278 Defaults to @samp{(5347)}.
16281 @deftypevr {@code{prosody-configuration} parameter} string component-interface
16282 Interface Prosody listens on for component connections.
16283 Defaults to @samp{"127.0.0.1"}.
16286 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
16287 Raw content that will be added to the configuration file.
16290 It could be that you just want to get a @code{prosody.cfg.lua}
16291 up and running. In that case, you can pass an
16292 @code{opaque-prosody-configuration} record as the value of
16293 @code{prosody-service-type}. As its name indicates, an opaque configuration
16294 does not have easy reflective capabilities.
16295 Available @code{opaque-prosody-configuration} fields are:
16297 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
16298 The prosody package.
16301 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
16302 The contents of the @code{prosody.cfg.lua} to use.
16305 For example, if your @code{prosody.cfg.lua} is just the empty
16306 string, you could instantiate a prosody service like this:
16309 (service prosody-service-type
16310 (opaque-prosody-configuration
16311 (prosody.cfg.lua "")))
16314 @c end of Prosody auto-generated documentation
16316 @subsubheading BitlBee Service
16318 @cindex IRC (Internet Relay Chat)
16319 @cindex IRC gateway
16320 @url{http://bitlbee.org,BitlBee} is a gateway that provides an IRC
16321 interface to a variety of messaging protocols such as XMPP.
16323 @defvr {Scheme Variable} bitlbee-service-type
16324 This is the service type for the @url{http://bitlbee.org,BitlBee} IRC
16325 gateway daemon. Its value is a @code{bitlbee-configuration} (see
16328 To have BitlBee listen on port 6667 on localhost, add this line to your
16332 (service bitlbee-service-type)
16336 @deftp {Data Type} bitlbee-configuration
16337 This is the configuration for BitlBee, with the following fields:
16340 @item @code{interface} (default: @code{"127.0.0.1"})
16341 @itemx @code{port} (default: @code{6667})
16342 Listen on the network interface corresponding to the IP address
16343 specified in @var{interface}, on @var{port}.
16345 When @var{interface} is @code{127.0.0.1}, only local clients can
16346 connect; when it is @code{0.0.0.0}, connections can come from any
16347 networking interface.
16349 @item @code{package} (default: @code{bitlbee})
16350 The BitlBee package to use.
16352 @item @code{plugins} (default: @code{'()})
16353 List of plugin packages to use---e.g., @code{bitlbee-discord}.
16355 @item @code{extra-settings} (default: @code{""})
16356 Configuration snippet added as-is to the BitlBee configuration file.
16360 @subsubheading Quassel Service
16362 @cindex IRC (Internet Relay Chat)
16363 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
16364 meaning that one or more clients can attach to and detach from the
16367 @defvr {Scheme Variable} quassel-service-type
16368 This is the service type for the @url{https://quassel-irc.org/,Quassel}
16369 IRC backend daemon. Its value is a @code{quassel-configuration}
16373 @deftp {Data Type} quassel-configuration
16374 This is the configuration for Quassel, with the following fields:
16377 @item @code{quassel} (default: @code{quassel})
16378 The Quassel package to use.
16380 @item @code{interface} (default: @code{"::,0.0.0.0"})
16381 @item @code{port} (default: @code{4242})
16382 Listen on the network interface(s) corresponding to the IPv4 or IPv6
16383 interfaces specified in the comma delimited @var{interface}, on
16386 @item @code{loglevel} (default: @code{"Info"})
16387 The level of logging desired. Accepted values are Debug, Info, Warning
16392 @node Telephony Services
16393 @subsection Telephony Services
16395 @cindex Murmur (VoIP server)
16396 @cindex VoIP server
16397 This section describes how to set up and run a Murmur server. Murmur is
16398 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
16401 @deftp {Data Type} murmur-configuration
16402 The service type for the Murmur server. An example configuration can
16406 (service murmur-service-type
16407 (murmur-configuration
16409 "Welcome to this Mumble server running on GuixSD!")
16410 (cert-required? #t) ;disallow text password logins
16411 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
16412 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
16415 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
16416 password with the command that is printed during the activation phase.
16418 It is recommended to register a normal Mumble user account
16419 and grant it admin or moderator rights.
16420 You can use the @code{mumble} client to
16421 login as new normal user, register yourself, and log out.
16422 For the next step login with the name @code{SuperUser} use
16423 the @code{SuperUser} password that you set previously,
16424 and grant your newly registered mumble user administrator or moderator
16425 rights and create some channels.
16427 Available @code{murmur-configuration} fields are:
16430 @item @code{package} (default: @code{mumble})
16431 Package that contains @code{bin/murmurd}.
16433 @item @code{user} (default: @code{"murmur"})
16434 User who will run the Murmur server.
16436 @item @code{group} (default: @code{"murmur"})
16437 Group of the user who will run the murmur server.
16439 @item @code{port} (default: @code{64738})
16440 Port on which the server will listen.
16442 @item @code{welcome-text} (default: @code{""})
16443 Welcome text sent to clients when they connect.
16445 @item @code{server-password} (default: @code{""})
16446 Password the clients have to enter in order to connect.
16448 @item @code{max-users} (default: @code{100})
16449 Maximum of users that can be connected to the server at once.
16451 @item @code{max-user-bandwidth} (default: @code{#f})
16452 Maximum voice traffic a user can send per second.
16454 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
16455 File name of the sqlite database.
16456 The service's user will become the owner of the directory.
16458 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
16459 File name of the log file.
16460 The service's user will become the owner of the directory.
16462 @item @code{autoban-attempts} (default: @code{10})
16463 Maximum number of logins a user can make in @code{autoban-timeframe}
16464 without getting auto banned for @code{autoban-time}.
16466 @item @code{autoban-timeframe} (default: @code{120})
16467 Timeframe for autoban in seconds.
16469 @item @code{autoban-time} (default: @code{300})
16470 Amount of time in seconds for which a client gets banned
16471 when violating the autoban limits.
16473 @item @code{opus-threshold} (default: @code{100})
16474 Percentage of clients that need to support opus
16475 before switching over to opus audio codec.
16477 @item @code{channel-nesting-limit} (default: @code{10})
16478 How deep channels can be nested at maximum.
16480 @item @code{channelname-regex} (default: @code{#f})
16481 A string in form of a Qt regular expression that channel names must conform to.
16483 @item @code{username-regex} (default: @code{#f})
16484 A string in form of a Qt regular expression that user names must conform to.
16486 @item @code{text-message-length} (default: @code{5000})
16487 Maximum size in bytes that a user can send in one text chat message.
16489 @item @code{image-message-length} (default: @code{(* 128 1024)})
16490 Maximum size in bytes that a user can send in one image message.
16492 @item @code{cert-required?} (default: @code{#f})
16493 If it is set to @code{#t} clients that use weak password authentification
16494 will not be accepted. Users must have completed the certificate wizard to join.
16496 @item @code{remember-channel?} (default: @code{#f})
16497 Should murmur remember the last channel each user was in when they disconnected
16498 and put them into the remembered channel when they rejoin.
16500 @item @code{allow-html?} (default: @code{#f})
16501 Should html be allowed in text messages, user comments, and channel descriptions.
16503 @item @code{allow-ping?} (default: @code{#f})
16504 Setting to true exposes the current user count, the maximum user count, and
16505 the server's maximum bandwidth per client to unauthenticated users. In the
16506 Mumble client, this information is shown in the Connect dialog.
16508 Disabling this setting will prevent public listing of the server.
16510 @item @code{bonjour?} (default: @code{#f})
16511 Should the server advertise itself in the local network through the bonjour protocol.
16513 @item @code{send-version?} (default: @code{#f})
16514 Should the murmur server version be exposed in ping requests.
16516 @item @code{log-days} (default: @code{31})
16517 Murmur also stores logs in the database, which are accessible via RPC.
16518 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
16519 or -1 to disable logging to the database.
16521 @item @code{obfuscate-ips?} (default: @code{#t})
16522 Should logged ips be obfuscated to protect the privacy of users.
16524 @item @code{ssl-cert} (default: @code{#f})
16525 File name of the SSL/TLS certificate used for encrypted connections.
16528 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
16530 @item @code{ssl-key} (default: @code{#f})
16531 Filepath to the ssl private key used for encrypted connections.
16533 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
16536 @item @code{ssl-dh-params} (default: @code{#f})
16537 File name of a PEM-encoded file with Diffie-Hellman parameters
16538 for the SSL/TLS encryption. Alternatively you set it to
16539 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
16540 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
16542 @item @code{ssl-ciphers} (default: @code{#f})
16543 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
16546 This option is specified using
16547 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
16548 OpenSSL cipher list notation}.
16550 It is recommended that you try your cipher string using 'openssl ciphers <string>'
16551 before setting it here, to get a feel for which cipher suites you will get.
16552 After setting this option, it is recommend that you inspect your Murmur log
16553 to ensure that Murmur is using the cipher suites that you expected it to.
16555 Note: Changing this option may impact the backwards compatibility of your
16556 Murmur server, and can remove the ability for older Mumble clients to be able
16559 @item @code{public-registration} (default: @code{#f})
16560 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
16562 You can optionally register your server in the public server list that the
16563 @code{mumble} client shows on startup.
16564 You cannot register your server if you have set a @code{server-password},
16565 or set @code{allow-ping} to @code{#f}.
16567 It might take a few hours until it shows up in the public list.
16569 @item @code{file} (default: @code{#f})
16570 Optional alternative override for this configuration.
16574 @deftp {Data Type} murmur-public-registration-configuration
16575 Configuration for public registration of a murmur service.
16579 This is a display name for your server. Not to be confused with the hostname.
16581 @item @code{password}
16582 A password to identify your registration.
16583 Subsequent updates will need the same password. Don't lose your password.
16586 This should be a @code{http://} or @code{https://} link to your web
16589 @item @code{hostname} (default: @code{#f})
16590 By default your server will be listed by its IP address.
16591 If it is set your server will be linked by this host name instead.
16597 @node Monitoring Services
16598 @subsection Monitoring Services
16600 @subsubheading Tailon Service
16602 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
16603 viewing and searching log files.
16605 The following example will configure the service with default values.
16606 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
16609 (service tailon-service-type)
16612 The following example customises more of the Tailon configuration,
16613 adding @command{sed} to the list of allowed commands.
16616 (service tailon-service-type
16617 (tailon-configuration
16619 (tailon-configuration-file
16620 (allowed-commands '("tail" "grep" "awk" "sed"))))))
16624 @deftp {Data Type} tailon-configuration
16625 Data type representing the configuration of Tailon.
16626 This type has the following parameters:
16629 @item @code{config-file} (default: @code{(tailon-configuration-file)})
16630 The configuration file to use for Tailon. This can be set to a
16631 @dfn{tailon-configuration-file} record value, or any gexp
16632 (@pxref{G-Expressions}).
16634 For example, to instead use a local file, the @code{local-file} function
16638 (service tailon-service-type
16639 (tailon-configuration
16640 (config-file (local-file "./my-tailon.conf"))))
16643 @item @code{package} (default: @code{tailon})
16644 The tailon package to use.
16649 @deftp {Data Type} tailon-configuration-file
16650 Data type representing the configuration options for Tailon.
16651 This type has the following parameters:
16654 @item @code{files} (default: @code{(list "/var/log")})
16655 List of files to display. The list can include strings for a single file
16656 or directory, or a list, where the first item is the name of a
16657 subsection, and the remaining items are the files or directories in that
16660 @item @code{bind} (default: @code{"localhost:8080"})
16661 Address and port to which Tailon should bind on.
16663 @item @code{relative-root} (default: @code{#f})
16664 URL path to use for Tailon, set to @code{#f} to not use a path.
16666 @item @code{allow-transfers?} (default: @code{#t})
16667 Allow downloading the log files in the web interface.
16669 @item @code{follow-names?} (default: @code{#t})
16670 Allow tailing of not-yet existent files.
16672 @item @code{tail-lines} (default: @code{200})
16673 Number of lines to read initially from each file.
16675 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
16676 Commands to allow running. By default, @code{sed} is disabled.
16678 @item @code{debug?} (default: @code{#f})
16679 Set @code{debug?} to @code{#t} to show debug messages.
16681 @item @code{wrap-lines} (default: @code{#t})
16682 Initial line wrapping state in the web interface. Set to @code{#t} to
16683 initially wrap lines (the default), or to @code{#f} to initially not
16686 @item @code{http-auth} (default: @code{#f})
16687 HTTP authentication type to use. Set to @code{#f} to disable
16688 authentication (the default). Supported values are @code{"digest"} or
16691 @item @code{users} (default: @code{#f})
16692 If HTTP authentication is enabled (see @code{http-auth}), access will be
16693 restricted to the credentials provided here. To configure users, use a
16694 list of pairs, where the first element of the pair is the username, and
16695 the 2nd element of the pair is the password.
16698 (tailon-configuration-file
16699 (http-auth "basic")
16700 (users '(("user1" . "password1")
16701 ("user2" . "password2"))))
16708 @subsubheading Darkstat Service
16710 Darkstat is a packet sniffer that captures network traffic, calculates
16711 statistics about usage, and serves reports over HTTP.
16713 @defvar {Scheme Variable} darkstat-service-type
16714 This is the service type for the
16715 @uref{https://unix4lyfe.org/darkstat/, darkstat}
16716 service, its value must be a @code{darkstat-configuration} record as in
16720 (service darkstat-service-type
16721 (darkstat-configuration
16722 (interface "eno1")))
16726 @deftp {Data Type} darkstat-configuration
16727 Data type representing the configuration of @command{darkstat}.
16730 @item @code{package} (default: @code{darkstat})
16731 The darkstat package to use.
16733 @item @code{interface}
16734 Capture traffic on the specified network interface.
16736 @item @code{port} (default: @code{"667"})
16737 Bind the web interface to the specified port.
16739 @item @code{bind-address} (default: @code{"127.0.0.1"})
16740 Bind the web interface to the specified address.
16742 @item @code{base} (default: @code{"/"})
16743 Specify the path of the base URL. This can be useful if
16744 @command{darkstat} is accessed via a reverse proxy.
16749 @subsubheading Prometheus Node Exporter Service
16751 @cindex prometheus-node-exporter
16752 The Prometheus ``node exporter'' makes hardware and operating system statistics
16753 provided by the Linux kernel available for the Prometheus monitoring system.
16754 This service should be deployed on all physical nodes and virtual machines,
16755 where monitoring these statistics is desirable.
16757 @defvar {Scheme variable} prometheus-node-exporter-service-type
16758 This is the service type for the
16759 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
16760 service, its value must be a @code{prometheus-node-exporter-configuration}
16761 record as in this example:
16764 (service prometheus-node-exporter-service-type
16765 (prometheus-node-exporter-configuration
16766 (web-listen-address ":9100")))
16770 @deftp {Data Type} prometheus-node-exporter-configuration
16771 Data type representing the configuration of @command{node_exporter}.
16774 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
16775 The prometheus-node-exporter package to use.
16777 @item @code{web-listen-address} (default: @code{":9100"})
16778 Bind the web interface to the specified address.
16783 @subsubheading Zabbix server
16784 @cindex zabbix zabbix-server
16785 Zabbix provides monitoring metrics, among others network utilization, CPU load
16786 and disk space consumption:
16789 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
16790 @item Auto-discovery of servers and network devices and interfaces.
16791 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
16792 @item Distributed monitoring with centralized web administration.
16793 @item Native high performance agents.
16794 @item SLA, and ITIL KPI metrics on reporting.
16795 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
16796 @item Remote command execution through Zabbix proxies.
16799 @c %start of fragment
16801 Available @code{zabbix-server-configuration} fields are:
16803 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
16804 The zabbix-server package.
16808 @deftypevr {@code{zabbix-server-configuration} parameter} string user
16809 User who will run the Zabbix server.
16811 Defaults to @samp{"zabbix"}.
16815 @deftypevr {@code{zabbix-server-configuration} parameter} group group
16816 Group who will run the Zabbix server.
16818 Defaults to @samp{"zabbix"}.
16822 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
16823 Database host name.
16825 Defaults to @samp{"127.0.0.1"}.
16829 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
16832 Defaults to @samp{"zabbix"}.
16836 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
16839 Defaults to @samp{"zabbix"}.
16843 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
16844 Database password. Please, use @code{include-files} with
16845 @code{DBPassword=SECRET} inside a specified file instead.
16847 Defaults to @samp{""}.
16851 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
16854 Defaults to @samp{5432}.
16858 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
16859 Specifies where log messages are written to:
16863 @code{system} - syslog.
16866 @code{file} - file specified with @code{log-file} parameter.
16869 @code{console} - standard output.
16873 Defaults to @samp{""}.
16877 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
16878 Log file name for @code{log-type} @code{file} parameter.
16880 Defaults to @samp{"/var/log/zabbix/server.log"}.
16884 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
16887 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
16891 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
16892 The location of certificate authority (CA) files for SSL server
16893 certificate verification.
16895 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
16899 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
16900 Location of SSL client certificates.
16902 Defaults to @samp{"/etc/ssl/certs"}.
16906 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
16907 Extra options will be appended to Zabbix server configuration file.
16909 Defaults to @samp{""}.
16913 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
16914 You may include individual files or all files in a directory in the
16915 configuration file.
16917 Defaults to @samp{()}.
16921 @c %end of fragment
16923 @subsubheading Zabbix agent
16924 @cindex zabbix zabbix-agent
16926 Zabbix agent gathers information for Zabbix server.
16928 @c %start of fragment
16930 Available @code{zabbix-agent-configuration} fields are:
16932 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
16933 The zabbix-agent package.
16937 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
16938 User who will run the Zabbix agent.
16940 Defaults to @samp{"zabbix"}.
16944 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
16945 Group who will run the Zabbix agent.
16947 Defaults to @samp{"zabbix"}.
16951 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
16952 Unique, case sensitive hostname which is required for active checks and
16953 must match hostname as configured on the server.
16955 Defaults to @samp{"Zabbix server"}.
16959 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
16960 Specifies where log messages are written to:
16964 @code{system} - syslog.
16967 @code{file} - file specified with @code{log-file} parameter.
16970 @code{console} - standard output.
16974 Defaults to @samp{""}.
16978 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
16979 Log file name for @code{log-type} @code{file} parameter.
16981 Defaults to @samp{"/var/log/zabbix/agent.log"}.
16985 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
16988 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
16992 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
16993 List of IP addresses, optionally in CIDR notation, or hostnames of
16994 Zabbix servers and Zabbix proxies. Incoming connections will be
16995 accepted only from the hosts listed here.
16997 Defaults to @samp{("127.0.0.1")}.
17001 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
17002 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
17003 proxies for active checks. If port is not specified, default port is
17004 used. If this parameter is not specified, active checks are disabled.
17006 Defaults to @samp{("127.0.0.1")}.
17010 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
17011 Extra options will be appended to Zabbix server configuration file.
17013 Defaults to @samp{""}.
17017 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
17018 You may include individual files or all files in a directory in the
17019 configuration file.
17021 Defaults to @samp{()}.
17025 @c %end of fragment
17027 @subsubheading Zabbix front-end
17028 @cindex zabbix zabbix-front-end
17030 This service provides a WEB interface to Zabbix server.
17032 @c %start of fragment
17034 Available @code{zabbix-front-end-configuration} fields are:
17036 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
17037 NGINX configuration.
17041 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
17042 Database host name.
17044 Defaults to @samp{"localhost"}.
17048 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
17051 Defaults to @samp{5432}.
17055 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
17058 Defaults to @samp{"zabbix"}.
17062 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
17065 Defaults to @samp{"zabbix"}.
17069 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
17070 Database password. Please, use @code{db-secret-file} instead.
17072 Defaults to @samp{""}.
17076 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
17077 Secret file which will be appended to @file{zabbix.conf.php} file. This
17078 file contains credentials for use by Zabbix front-end. You are expected
17079 to create it manually.
17081 Defaults to @samp{""}.
17085 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
17086 Zabbix server hostname.
17088 Defaults to @samp{"localhost"}.
17092 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
17093 Zabbix server port.
17095 Defaults to @samp{10051}.
17100 @c %end of fragment
17102 @node Kerberos Services
17103 @subsection Kerberos Services
17106 The @code{(gnu services kerberos)} module provides services relating to
17107 the authentication protocol @dfn{Kerberos}.
17109 @subsubheading Krb5 Service
17111 Programs using a Kerberos client library normally
17112 expect a configuration file in @file{/etc/krb5.conf}.
17113 This service generates such a file from a definition provided in the
17114 operating system declaration.
17115 It does not cause any daemon to be started.
17117 No ``keytab'' files are provided by this service---you must explicitly create them.
17118 This service is known to work with the MIT client library, @code{mit-krb5}.
17119 Other implementations have not been tested.
17121 @defvr {Scheme Variable} krb5-service-type
17122 A service type for Kerberos 5 clients.
17126 Here is an example of its use:
17128 (service krb5-service-type
17129 (krb5-configuration
17130 (default-realm "EXAMPLE.COM")
17131 (allow-weak-crypto? #t)
17134 (name "EXAMPLE.COM")
17135 (admin-server "groucho.example.com")
17136 (kdc "karl.example.com"))
17139 (admin-server "kerb-admin.argrx.edu")
17140 (kdc "keys.argrx.edu"))))))
17144 This example provides a Kerberos@tie{}5 client configuration which:
17146 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
17147 of which have distinct administration servers and key distribution centers;
17148 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
17149 specified by clients;
17150 @item Accepts services which only support encryption types known to be weak.
17153 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
17154 Only the most commonly used ones are described here.
17155 For a full list, and more detailed explanation of each, see the MIT
17156 @uref{http://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
17160 @deftp {Data Type} krb5-realm
17161 @cindex realm, kerberos
17164 This field is a string identifying the name of the realm.
17165 A common convention is to use the fully qualified DNS name of your organization,
17166 converted to upper case.
17168 @item @code{admin-server}
17169 This field is a string identifying the host where the administration server is
17173 This field is a string identifying the key distribution center
17178 @deftp {Data Type} krb5-configuration
17181 @item @code{allow-weak-crypto?} (default: @code{#f})
17182 If this flag is @code{#t} then services which only offer encryption algorithms
17183 known to be weak will be accepted.
17185 @item @code{default-realm} (default: @code{#f})
17186 This field should be a string identifying the default Kerberos
17187 realm for the client.
17188 You should set this field to the name of your Kerberos realm.
17189 If this value is @code{#f}
17190 then a realm must be specified with every Kerberos principal when invoking programs
17191 such as @command{kinit}.
17193 @item @code{realms}
17194 This should be a non-empty list of @code{krb5-realm} objects, which clients may
17196 Normally, one of them will have a @code{name} field matching the @code{default-realm}
17202 @subsubheading PAM krb5 Service
17205 The @code{pam-krb5} service allows for login authentication and password
17206 management via Kerberos.
17207 You will need this service if you want PAM enabled applications to authenticate
17208 users using Kerberos.
17210 @defvr {Scheme Variable} pam-krb5-service-type
17211 A service type for the Kerberos 5 PAM module.
17214 @deftp {Data Type} pam-krb5-configuration
17215 Data type representing the configuration of the Kerberos 5 PAM module
17216 This type has the following parameters:
17218 @item @code{pam-krb5} (default: @code{pam-krb5})
17219 The pam-krb5 package to use.
17221 @item @code{minimum-uid} (default: @code{1000})
17222 The smallest user ID for which Kerberos authentications should be attempted.
17223 Local accounts with lower values will silently fail to authenticate.
17229 @subsection Web Services
17234 The @code{(gnu services web)} module provides the Apache HTTP Server,
17235 the nginx web server, and also a fastcgi wrapper daemon.
17237 @subsubheading Apache HTTP Server
17239 @deffn {Scheme Variable} httpd-service-type
17240 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
17241 (@dfn{httpd}). The value for this service type is a
17242 @code{httpd-configuration} record.
17244 A simple example configuration is given below.
17247 (service httpd-service-type
17248 (httpd-configuration
17251 (server-name "www.example.com")
17252 (document-root "/srv/http/www.example.com")))))
17255 Other services can also extend the @code{httpd-service-type} to add to
17259 (simple-service 'my-extra-server httpd-service-type
17263 (list (string-append
17264 "ServerName "www.example.com
17265 DocumentRoot \"/srv/http/www.example.com\"")))))
17269 The details for the @code{httpd-configuration}, @code{httpd-module},
17270 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
17273 @deffn {Data Type} httpd-configuration
17274 This data type represents the configuration for the httpd service.
17277 @item @code{package} (default: @code{httpd})
17278 The httpd package to use.
17280 @item @code{pid-file} (default: @code{"/var/run/httpd"})
17281 The pid file used by the shepherd-service.
17283 @item @code{config} (default: @code{(httpd-config-file)})
17284 The configuration file to use with the httpd service. The default value
17285 is a @code{httpd-config-file} record, but this can also be a different
17286 G-expression that generates a file, for example a @code{plain-file}. A
17287 file outside of the store can also be specified through a string.
17292 @deffn {Data Type} httpd-module
17293 This data type represents a module for the httpd service.
17297 The name of the module.
17300 The file for the module. This can be relative to the httpd package being
17301 used, the absolute location of a file, or a G-expression for a file
17302 within the store, for example @code{(file-append mod-wsgi
17303 "/modules/mod_wsgi.so")}.
17308 @defvr {Scheme Variable} %default-httpd-modules
17309 A default list of @code{httpd-module} objects.
17312 @deffn {Data Type} httpd-config-file
17313 This data type represents a configuration file for the httpd service.
17316 @item @code{modules} (default: @code{%default-httpd-modules})
17317 The modules to load. Additional modules can be added here, or loaded by
17318 additional configuration.
17320 For example, in order to handle requests for PHP files, you can use Apache’s
17321 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
17324 (service httpd-service-type
17325 (httpd-configuration
17330 (name "proxy_module")
17331 (file "modules/mod_proxy.so"))
17333 (name "proxy_fcgi_module")
17334 (file "modules/mod_proxy_fcgi.so"))
17335 %default-httpd-modules))
17336 (extra-config (list "\
17337 <FilesMatch \\.php$>
17338 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
17339 </FilesMatch>"))))))
17340 (service php-fpm-service-type
17341 (php-fpm-configuration
17342 (socket "/var/run/php-fpm.sock")
17343 (socket-group "httpd")))
17346 @item @code{server-root} (default: @code{httpd})
17347 The @code{ServerRoot} in the configuration file, defaults to the httpd
17348 package. Directives including @code{Include} and @code{LoadModule} are
17349 taken as relative to the server root.
17351 @item @code{server-name} (default: @code{#f})
17352 The @code{ServerName} in the configuration file, used to specify the
17353 request scheme, hostname and port that the server uses to identify
17356 This doesn't need to be set in the server config, and can be specifyed
17357 in virtual hosts. The default is @code{#f} to not specify a
17360 @item @code{document-root} (default: @code{"/srv/http"})
17361 The @code{DocumentRoot} from which files will be served.
17363 @item @code{listen} (default: @code{'("80")})
17364 The list of values for the @code{Listen} directives in the config
17365 file. The value should be a list of strings, when each string can
17366 specify the port number to listen on, and optionally the IP address and
17369 @item @code{pid-file} (default: @code{"/var/run/httpd"})
17370 The @code{PidFile} to use. This should match the @code{pid-file} set in
17371 the @code{httpd-configuration} so that the Shepherd service is
17372 configured correctly.
17374 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
17375 The @code{ErrorLog} to which the server will log errors.
17377 @item @code{user} (default: @code{"httpd"})
17378 The @code{User} which the server will answer requests as.
17380 @item @code{group} (default: @code{"httpd"})
17381 The @code{Group} which the server will answer requests as.
17383 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
17384 A flat list of strings and G-expressions which will be added to the end
17385 of the configuration file.
17387 Any values which the service is extended with will be appended to this
17393 @deffn {Data Type} httpd-virtualhost
17394 This data type represents a virtualhost configuration block for the httpd service.
17396 These should be added to the extra-config for the httpd-service.
17399 (simple-service 'my-extra-server httpd-service-type
17403 (list (string-append
17404 "ServerName "www.example.com
17405 DocumentRoot \"/srv/http/www.example.com\"")))))
17409 @item @code{addresses-and-ports}
17410 The addresses and ports for the @code{VirtualHost} directive.
17412 @item @code{contents}
17413 The contents of the @code{VirtualHost} directive, this should be a list
17414 of strings and G-expressions.
17419 @subsubheading NGINX
17421 @deffn {Scheme Variable} nginx-service-type
17422 Service type for the @uref{https://nginx.org/,NGinx} web server. The
17423 value for this service type is a @code{<nginx-configuration>} record.
17425 A simple example configuration is given below.
17428 (service nginx-service-type
17429 (nginx-configuration
17431 (list (nginx-server-configuration
17432 (server-name '("www.example.com"))
17433 (root "/srv/http/www.example.com"))))))
17436 In addition to adding server blocks to the service configuration
17437 directly, this service can be extended by other services to add server
17438 blocks, as in this example:
17441 (simple-service 'my-extra-server nginx-service-type
17442 (list (nginx-server-configuration
17443 (root "/srv/http/extra-website")
17444 (try-files (list "$uri" "$uri/index.html")))))
17448 At startup, @command{nginx} has not yet read its configuration file, so
17449 it uses a default file to log error messages. If it fails to load its
17450 configuration file, that is where error messages are logged. After the
17451 configuration file is loaded, the default error log file changes as per
17452 configuration. In our case, startup error messages can be found in
17453 @file{/var/run/nginx/logs/error.log}, and after configuration in
17454 @file{/var/log/nginx/error.log}. The second location can be changed
17455 with the @var{log-directory} configuration option.
17457 @deffn {Data Type} nginx-configuration
17458 This data type represents the configuration for NGinx. Some
17459 configuration can be done through this and the other provided record
17460 types, or alternatively, a config file can be provided.
17463 @item @code{nginx} (default: @code{nginx})
17464 The nginx package to use.
17466 @item @code{log-directory} (default: @code{"/var/log/nginx"})
17467 The directory to which NGinx will write log files.
17469 @item @code{run-directory} (default: @code{"/var/run/nginx"})
17470 The directory in which NGinx will create a pid file, and write temporary
17473 @item @code{server-blocks} (default: @code{'()})
17474 A list of @dfn{server blocks} to create in the generated configuration
17475 file, the elements should be of type
17476 @code{<nginx-server-configuration>}.
17478 The following example would setup NGinx to serve @code{www.example.com}
17479 from the @code{/srv/http/www.example.com} directory, without using
17482 (service nginx-service-type
17483 (nginx-configuration
17485 (list (nginx-server-configuration
17486 (server-name '("www.example.com"))
17487 (root "/srv/http/www.example.com"))))))
17490 @item @code{upstream-blocks} (default: @code{'()})
17491 A list of @dfn{upstream blocks} to create in the generated configuration
17492 file, the elements should be of type
17493 @code{<nginx-upstream-configuration>}.
17495 Configuring upstreams through the @code{upstream-blocks} can be useful
17496 when combined with @code{locations} in the
17497 @code{<nginx-server-configuration>} records. The following example
17498 creates a server configuration with one location configuration, that
17499 will proxy requests to a upstream configuration, which will handle
17500 requests with two servers.
17505 (nginx-configuration
17507 (list (nginx-server-configuration
17508 (server-name '("www.example.com"))
17509 (root "/srv/http/www.example.com")
17512 (nginx-location-configuration
17514 (body '("proxy_pass http://server-proxy;"))))))))
17516 (list (nginx-upstream-configuration
17517 (name "server-proxy")
17518 (servers (list "server1.example.com"
17519 "server2.example.com")))))))
17522 @item @code{file} (default: @code{#f})
17523 If a configuration @var{file} is provided, this will be used, rather than
17524 generating a configuration file from the provided @code{log-directory},
17525 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
17526 proper operation, these arguments should match what is in @var{file} to ensure
17527 that the directories are created when the service is activated.
17529 This can be useful if you have an existing configuration file, or it's
17530 not possible to do what is required through the other parts of the
17531 nginx-configuration record.
17533 @item @code{server-names-hash-bucket-size} (default: @code{#f})
17534 Bucket size for the server names hash tables, defaults to @code{#f} to
17535 use the size of the processors cache line.
17537 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
17538 Maximum bucket size for the server names hash tables.
17540 @item @code{extra-content} (default: @code{""})
17541 Extra content for the @code{http} block. Should be string or a string
17542 valued G-expression.
17547 @deftp {Data Type} nginx-server-configuration
17548 Data type representing the configuration of an nginx server block.
17549 This type has the following parameters:
17552 @item @code{listen} (default: @code{'("80" "443 ssl")})
17553 Each @code{listen} directive sets the address and port for IP, or the
17554 path for a UNIX-domain socket on which the server will accept requests.
17555 Both address and port, or only address or only port can be specified.
17556 An address may also be a hostname, for example:
17559 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
17562 @item @code{server-name} (default: @code{(list 'default)})
17563 A list of server names this server represents. @code{'default} represents the
17564 default server for connections matching no other server.
17566 @item @code{root} (default: @code{"/srv/http"})
17567 Root of the website nginx will serve.
17569 @item @code{locations} (default: @code{'()})
17570 A list of @dfn{nginx-location-configuration} or
17571 @dfn{nginx-named-location-configuration} records to use within this
17574 @item @code{index} (default: @code{(list "index.html")})
17575 Index files to look for when clients ask for a directory. If it cannot be found,
17576 Nginx will send the list of files in the directory.
17578 @item @code{try-files} (default: @code{'()})
17579 A list of files whose existence is checked in the specified order.
17580 @code{nginx} will use the first file it finds to process the request.
17582 @item @code{ssl-certificate} (default: @code{#f})
17583 Where to find the certificate for secure connections. Set it to @code{#f} if
17584 you don't have a certificate or you don't want to use HTTPS.
17586 @item @code{ssl-certificate-key} (default: @code{#f})
17587 Where to find the private key for secure connections. Set it to @code{#f} if
17588 you don't have a key or you don't want to use HTTPS.
17590 @item @code{server-tokens?} (default: @code{#f})
17591 Whether the server should add its configuration to response.
17593 @item @code{raw-content} (default: @code{'()})
17594 A list of raw lines added to the server block.
17599 @deftp {Data Type} nginx-upstream-configuration
17600 Data type representing the configuration of an nginx @code{upstream}
17601 block. This type has the following parameters:
17605 Name for this group of servers.
17607 @item @code{servers}
17608 Specify the addresses of the servers in the group. The address can be
17609 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
17610 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
17611 prefix @samp{unix:}. For addresses using an IP address or domain name,
17612 the default port is 80, and a different port can be specified
17618 @deftp {Data Type} nginx-location-configuration
17619 Data type representing the configuration of an nginx @code{location}
17620 block. This type has the following parameters:
17624 URI which this location block matches.
17626 @anchor{nginx-location-configuration body}
17628 Body of the location block, specified as a list of strings. This can contain
17630 configuration directives. For example, to pass requests to a upstream
17631 server group defined using an @code{nginx-upstream-configuration} block,
17632 the following directive would be specified in the body @samp{(list "proxy_pass
17633 http://upstream-name;")}.
17638 @deftp {Data Type} nginx-named-location-configuration
17639 Data type representing the configuration of an nginx named location
17640 block. Named location blocks are used for request redirection, and not
17641 used for regular request processing. This type has the following
17646 Name to identify this location block.
17649 @xref{nginx-location-configuration body}, as the body for named location
17650 blocks can be used in a similar way to the
17651 @code{nginx-location-configuration body}. One restriction is that the
17652 body of a named location block cannot contain location blocks.
17657 @subsubheading Varnish Cache
17659 Varnish is a fast cache server that sits in between web applications
17660 and end users. It proxies requests from clients and caches the
17661 accessed URLs such that multiple requests for the same resource only
17662 creates one request to the back-end.
17664 @defvr {Scheme Variable} varnish-service-type
17665 Service type for the Varnish daemon.
17668 @deftp {Data Type} varnish-configuration
17669 Data type representing the @code{varnish} service configuration.
17670 This type has the following parameters:
17673 @item @code{package} (default: @code{varnish})
17674 The Varnish package to use.
17676 @item @code{name} (default: @code{"default"})
17677 A name for this Varnish instance. Varnish will create a directory in
17678 @file{/var/varnish/} with this name and keep temporary files there. If
17679 the name starts with a forward slash, it is interpreted as an absolute
17682 Pass the @code{-n} argument to other Varnish programs to connect to the
17683 named instance, e.g.@: @command{varnishncsa -n default}.
17685 @item @code{backend} (default: @code{"localhost:8080"})
17686 The backend to use. This option has no effect if @code{vcl} is set.
17688 @item @code{vcl} (default: #f)
17689 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
17690 is @code{#f}, Varnish will proxy @code{backend} using the default
17691 configuration. Otherwise this must be a file-like object with valid
17694 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
17695 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
17696 can do something along these lines:
17699 (define %gnu-mirror
17703 backend gnu @{ .host = "www.gnu.org"; @}"))
17707 (services (cons (service varnish-service-type
17708 (varnish-configuration
17710 (vcl %gnu-mirror)))
17714 The configuration of an already running Varnish instance can be inspected
17715 and changed using the @command{varnishadm} program.
17717 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
17718 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
17719 comprehensive documentation on Varnish and its configuration language.
17721 @item @code{listen} (default: @code{'("localhost:80")})
17722 List of addresses Varnish will listen on.
17724 @item @code{storage} (default: @code{'("malloc,128m")})
17725 List of storage backends that will be available in VCL.
17727 @item @code{parameters} (default: @code{'()})
17728 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
17730 @item @code{extra-options} (default: @code{'()})
17731 Additional arguments to pass to the @command{varnishd} process.
17736 @subsubheading FastCGI
17739 FastCGI is an interface between the front-end and the back-end of a web
17740 service. It is a somewhat legacy facility; new web services should
17741 generally just talk HTTP between the front-end and the back-end.
17742 However there are a number of back-end services such as PHP or the
17743 optimized HTTP Git repository access that use FastCGI, so we have
17744 support for it in Guix.
17746 To use FastCGI, you configure the front-end web server (e.g., nginx) to
17747 dispatch some subset of its requests to the fastcgi backend, which
17748 listens on a local TCP or UNIX socket. There is an intermediary
17749 @code{fcgiwrap} program that sits between the actual backend process and
17750 the web server. The front-end indicates which backend program to run,
17751 passing that information to the @code{fcgiwrap} process.
17753 @defvr {Scheme Variable} fcgiwrap-service-type
17754 A service type for the @code{fcgiwrap} FastCGI proxy.
17757 @deftp {Data Type} fcgiwrap-configuration
17758 Data type representing the configuration of the @code{fcgiwrap} service.
17759 This type has the following parameters:
17761 @item @code{package} (default: @code{fcgiwrap})
17762 The fcgiwrap package to use.
17764 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
17765 The socket on which the @code{fcgiwrap} process should listen, as a
17766 string. Valid @var{socket} values include
17767 @code{unix:@var{/path/to/unix/socket}},
17768 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
17769 @code{tcp6:[@var{ipv6_addr}]:port}.
17771 @item @code{user} (default: @code{fcgiwrap})
17772 @itemx @code{group} (default: @code{fcgiwrap})
17773 The user and group names, as strings, under which to run the
17774 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
17775 the user asks for the specific user or group names @code{fcgiwrap} that
17776 the corresponding user and/or group is present on the system.
17778 It is possible to configure a FastCGI-backed web service to pass HTTP
17779 authentication information from the front-end to the back-end, and to
17780 allow @code{fcgiwrap} to run the back-end process as a corresponding
17781 local user. To enable this capability on the back-end., run
17782 @code{fcgiwrap} as the @code{root} user and group. Note that this
17783 capability also has to be configured on the front-end as well.
17788 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
17789 with some additional features useful for sites of any size.
17791 These features include:
17793 @item Adaptive process spawning
17794 @item Basic statistics (similar to Apache's mod_status)
17795 @item Advanced process management with graceful stop/start
17796 @item Ability to start workers with different uid/gid/chroot/environment
17797 and different php.ini (replaces safe_mode)
17798 @item Stdout & stderr logging
17799 @item Emergency restart in case of accidental opcode cache destruction
17800 @item Accelerated upload support
17801 @item Support for a "slowlog"
17802 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
17803 a special function to finish request & flush all data while continuing to do
17804 something time-consuming (video converting, stats processing, etc.)
17806 ...@: and much more.
17808 @defvr {Scheme Variable} php-fpm-service-type
17809 A Service type for @code{php-fpm}.
17812 @deftp {Data Type} php-fpm-configuration
17813 Data Type for php-fpm service configuration.
17815 @item @code{php} (default: @code{php})
17816 The php package to use.
17817 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
17818 The address on which to accept FastCGI requests. Valid syntaxes are:
17820 @item @code{"ip.add.re.ss:port"}
17821 Listen on a TCP socket to a specific address on a specific port.
17822 @item @code{"port"}
17823 Listen on a TCP socket to all addresses on a specific port.
17824 @item @code{"/path/to/unix/socket"}
17825 Listen on a unix socket.
17828 @item @code{user} (default: @code{php-fpm})
17829 User who will own the php worker processes.
17830 @item @code{group} (default: @code{php-fpm})
17831 Group of the worker processes.
17832 @item @code{socket-user} (default: @code{php-fpm})
17833 User who can speak to the php-fpm socket.
17834 @item @code{socket-group} (default: @code{php-fpm})
17835 Group that can speak to the php-fpm socket.
17836 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
17837 The process id of the php-fpm process is written to this file
17838 once the service has started.
17839 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
17840 Log for the php-fpm master process.
17841 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
17842 Detailed settings for the php-fpm process manager.
17845 @item @code{<php-fpm-dynamic-process-manager-configuration>}
17846 @item @code{<php-fpm-static-process-manager-configuration>}
17847 @item @code{<php-fpm-on-demand-process-manager-configuration>}
17849 @item @code{display-errors} (default @code{#f})
17850 Determines whether php errors and warning should be sent to clients
17851 and displayed in their browsers.
17852 This is useful for local php development, but a security risk for public sites,
17853 as error messages can reveal passwords and personal data.
17854 @item @code{timezone} (default @code{#f})
17855 Specifies @code{php_admin_value[date.timezone]} parameter.
17856 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
17857 This file will log the @code{stderr} outputs of php worker processes.
17858 Can be set to @code{#f} to disable logging.
17859 @item @code{file} (default @code{#f})
17860 An optional override of the whole configuration.
17861 You can use the @code{mixed-text-file} function or an absolute filepath for it.
17865 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
17866 Data Type for the @code{dynamic} php-fpm process manager. With the
17867 @code{dynamic} process manager, spare worker processes are kept around
17868 based on it's configured limits.
17870 @item @code{max-children} (default: @code{5})
17871 Maximum of worker processes.
17872 @item @code{start-servers} (default: @code{2})
17873 How many worker processes should be started on start-up.
17874 @item @code{min-spare-servers} (default: @code{1})
17875 How many spare worker processes should be kept around at minimum.
17876 @item @code{max-spare-servers} (default: @code{3})
17877 How many spare worker processes should be kept around at maximum.
17881 @deftp {Data type} php-fpm-static-process-manager-configuration
17882 Data Type for the @code{static} php-fpm process manager. With the
17883 @code{static} process manager, an unchanging number of worker processes
17886 @item @code{max-children} (default: @code{5})
17887 Maximum of worker processes.
17891 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
17892 Data Type for the @code{on-demand} php-fpm process manager. With the
17893 @code{on-demand} process manager, worker processes are only created as
17896 @item @code{max-children} (default: @code{5})
17897 Maximum of worker processes.
17898 @item @code{process-idle-timeout} (default: @code{10})
17899 The time in seconds after which a process with no requests is killed.
17904 @deffn {Scheme Procedure} nginx-php-fpm-location @
17905 [#:nginx-package nginx] @
17906 [socket (string-append "/var/run/php" @
17907 (version-major (package-version php)) @
17909 A helper function to quickly add php to an @code{nginx-server-configuration}.
17912 A simple services setup for nginx with php can look like this:
17914 (services (cons* (service dhcp-client-service-type)
17915 (service php-fpm-service-type)
17916 (service nginx-service-type
17917 (nginx-server-configuration
17918 (server-name '("example.com"))
17919 (root "/srv/http/")
17921 (list (nginx-php-location)))
17923 (ssl-certificate #f)
17924 (ssl-certificate-key #f)))
17928 @cindex cat-avatar-generator
17929 The cat avatar generator is a simple service to demonstrate the use of php-fpm
17930 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
17931 the hash of a user's email address.
17933 @deffn {Scheme Procedure} cat-avatar-generator-service @
17934 [#:cache-dir "/var/cache/cat-avatar-generator"] @
17935 [#:package cat-avatar-generator] @
17936 [#:configuration (nginx-server-configuration)]
17937 Returns an nginx-server-configuration that inherits @code{configuration}. It
17938 extends the nginx configuration to add a server block that serves @code{package},
17939 a version of cat-avatar-generator. During execution, cat-avatar-generator will
17940 be able to use @code{cache-dir} as its cache directory.
17943 A simple setup for cat-avatar-generator can look like this:
17945 (services (cons* (cat-avatar-generator-service
17947 (nginx-server-configuration
17948 (server-name '("example.com"))))
17953 @subsubheading Hpcguix-web
17955 @cindex hpcguix-web
17956 The @uref{hpcguix-web, https://github.com/UMCUGenetics/hpcguix-web/}
17957 program is a customizable web interface to browse Guix packages,
17958 initially designed for users of high-performance computing (HPC)
17961 @defvr {Scheme Variable} hpcguix-web-service-type
17962 The service type for @code{hpcguix-web}.
17965 @deftp {Data Type} hpcguix-web-configuration
17966 Data type for the hpcguix-web service configuration.
17970 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
17971 configuration. The main items available in this spec are:
17974 @item @code{title-prefix} (default: @code{"hpcguix | "})
17975 The page title prefix.
17977 @item @code{guix-command} (default: @code{"guix"})
17978 The @command{guix} command.
17980 @item @code{package-filter-proc} (default: @code{(const #t)})
17981 A procedure specifying how to filter packages that are displayed.
17983 @item @code{package-page-extension-proc} (default: @code{(const '())})
17984 Extension package for @code{hpcguix-web}.
17986 @item @code{menu} (default: @code{'()})
17987 Additional entry in page @code{menu}.
17989 @item @code{channels} (default: @code{%default-channels})
17990 List of channels from which the package list is built (@pxref{Channels}).
17992 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
17993 The expiration time, in seconds, after which the package list is rebuilt from
17994 the latest instances of the given channels.
17997 See the hpcguix-web repository for a
17998 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
18001 @item @code{package} (default: @code{hpcguix-web})
18002 The hpcguix-web package to use.
18006 A typical hpcguix-web service declaration looks like this:
18009 (service hpcguix-web-service-type
18010 (hpcguix-web-configuration
18012 #~(define site-config
18013 (hpcweb-configuration
18014 (title-prefix "Guix-HPC - ")
18015 (menu '(("/about" "ABOUT"))))))))
18019 The hpcguix-web service periodically updates the package list it publishes by
18020 pulling channels from Git. To that end, it needs to access X.509 certificates
18021 so that it can authenticate Git servers when communicating over HTTPS, and it
18022 assumes that @file{/etc/ssl/certs} contains those certificates.
18024 Thus, make sure to add @code{nss-certs} or another certificate package to the
18025 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
18026 more information on X.509 certificates.
18029 @node Certificate Services
18030 @subsection Certificate Services
18033 @cindex HTTP, HTTPS
18034 @cindex Let's Encrypt
18035 @cindex TLS certificates
18036 The @code{(gnu services certbot)} module provides a service to
18037 automatically obtain a valid TLS certificate from the Let's Encrypt
18038 certificate authority. These certificates can then be used to serve
18039 content securely over HTTPS or other TLS-based protocols, with the
18040 knowledge that the client will be able to verify the server's
18043 @url{https://letsencrypt.org/, Let's Encrypt} provides the
18044 @code{certbot} tool to automate the certification process. This tool
18045 first securely generates a key on the server. It then makes a request
18046 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
18047 checks that the request originates from the host in question by using a
18048 challenge-response protocol, requiring the server to provide its
18049 response over HTTP. If that protocol completes successfully, the CA
18050 signs the key, resulting in a certificate. That certificate is valid
18051 for a limited period of time, and therefore to continue to provide TLS
18052 services, the server needs to periodically ask the CA to renew its
18055 The certbot service automates this process: the initial key
18056 generation, the initial certification request to the Let's Encrypt
18057 service, the web server challenge/response integration, writing the
18058 certificate to disk, the automated periodic renewals, and the deployment
18059 tasks associated with the renewal (e.g.@: reloading services, copying keys
18060 with different permissions).
18062 Certbot is run twice a day, at a random minute within the hour. It
18063 won't do anything until your certificates are due for renewal or
18064 revoked, but running it regularly would give your service a chance of
18065 staying online in case a Let's Encrypt-initiated revocation happened for
18068 By using this service, you agree to the ACME Subscriber Agreement, which
18069 can be found there:
18070 @url{https://acme-v01.api.letsencrypt.org/directory}.
18072 @defvr {Scheme Variable} certbot-service-type
18073 A service type for the @code{certbot} Let's Encrypt client. Its value
18074 must be a @code{certbot-configuration} record as in this example:
18077 (define %nginx-deploy-hook
18079 "nginx-deploy-hook"
18080 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
18081 (kill pid SIGHUP))))
18083 (service certbot-service-type
18084 (certbot-configuration
18085 (email "foo@@example.net")
18088 (certificate-configuration
18089 (domains '("example.net" "www.example.net"))
18090 (deploy-hook %nginx-deploy-hook))
18091 (certificate-configuration
18092 (domains '("bar.example.net")))))))
18095 See below for details about @code{certbot-configuration}.
18098 @deftp {Data Type} certbot-configuration
18099 Data type representing the configuration of the @code{certbot} service.
18100 This type has the following parameters:
18103 @item @code{package} (default: @code{certbot})
18104 The certbot package to use.
18106 @item @code{webroot} (default: @code{/var/www})
18107 The directory from which to serve the Let's Encrypt challenge/response
18110 @item @code{certificates} (default: @code{()})
18111 A list of @code{certificates-configuration}s for which to generate
18112 certificates and request signatures. Each certificate has a @code{name}
18113 and several @code{domains}.
18116 Mandatory email used for registration, recovery contact, and important
18117 account notifications.
18119 @item @code{rsa-key-size} (default: @code{2048})
18120 Size of the RSA key.
18122 @item @code{default-location} (default: @i{see below})
18123 The default @code{nginx-location-configuration}. Because @code{certbot}
18124 needs to be able to serve challenges and responses, it needs to be able
18125 to run a web server. It does so by extending the @code{nginx} web
18126 service with an @code{nginx-server-configuration} listening on the
18127 @var{domains} on port 80, and which has a
18128 @code{nginx-location-configuration} for the @code{/.well-known/} URI
18129 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
18130 these nginx configuration data types.
18132 Requests to other URL paths will be matched by the
18133 @code{default-location}, which if present is added to all
18134 @code{nginx-server-configuration}s.
18136 By default, the @code{default-location} will issue a redirect from
18137 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
18138 you to define what to serve on your site via @code{https}.
18140 Pass @code{#f} to not issue a default location.
18144 @deftp {Data Type} certificate-configuration
18145 Data type representing the configuration of a certificate.
18146 This type has the following parameters:
18149 @item @code{name} (default: @i{see below})
18150 This name is used by Certbot for housekeeping and in file paths; it
18151 doesn't affect the content of the certificate itself. To see
18152 certificate names, run @code{certbot certificates}.
18154 Its default is the first provided domain.
18156 @item @code{domains} (default: @code{()})
18157 The first domain provided will be the subject CN of the certificate, and
18158 all domains will be Subject Alternative Names on the certificate.
18160 @item @code{deploy-hook} (default: @code{#f})
18161 Command to be run in a shell once for each successfully issued
18162 certificate. For this command, the shell variable
18163 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
18164 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
18165 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
18166 contain a space-delimited list of renewed certificate domains (for
18167 example, @samp{"example.com www.example.com"}.
18172 For each @code{certificate-configuration}, the certificate is saved to
18173 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
18174 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
18176 @subsection DNS Services
18177 @cindex DNS (domain name system)
18178 @cindex domain name system (DNS)
18180 The @code{(gnu services dns)} module provides services related to the
18181 @dfn{domain name system} (DNS). It provides a server service for hosting
18182 an @emph{authoritative} DNS server for multiple zones, slave or master.
18183 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
18184 caching and forwarding DNS server for the LAN, which uses
18185 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
18187 @subsubheading Knot Service
18189 An example configuration of an authoritative server for two zones, one master
18193 (define-zone-entries example.org.zone
18194 ;; Name TTL Class Type Data
18195 ("@@" "" "IN" "A" "127.0.0.1")
18196 ("@@" "" "IN" "NS" "ns")
18197 ("ns" "" "IN" "A" "127.0.0.1"))
18199 (define master-zone
18200 (knot-zone-configuration
18201 (domain "example.org")
18203 (origin "example.org")
18204 (entries example.org.zone)))))
18207 (knot-zone-configuration
18208 (domain "plop.org")
18209 (dnssec-policy "default")
18210 (master (list "plop-master"))))
18212 (define plop-master
18213 (knot-remote-configuration
18215 (address (list "208.76.58.171"))))
18219 (services (cons* (service knot-service-type
18220 (knot-configuration
18221 (remotes (list plop-master))
18222 (zones (list master-zone slave-zone))))
18227 @deffn {Scheme Variable} knot-service-type
18228 This is the type for the Knot DNS server.
18230 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
18231 zones, that is to say domain names you would buy from a registrar. This server
18232 is not a resolver, meaning that it can only resolve names for which it is
18233 authoritative. This server can be configured to serve zones as a master server
18234 or a slave server as a per-zone basis. Slave zones will get their data from
18235 masters, and will serve it as an authoritative server. From the point of view
18236 of a resolver, there is no difference between master and slave.
18238 The following data types are used to configure the Knot DNS server:
18241 @deftp {Data Type} knot-key-configuration
18242 Data type representing a key.
18243 This type has the following parameters:
18246 @item @code{id} (default: @code{""})
18247 An identifier for other configuration fields to refer to this key. IDs must
18248 be unique and must not be empty.
18250 @item @code{algorithm} (default: @code{#f})
18251 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
18252 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
18253 and @code{'hmac-sha512}.
18255 @item @code{secret} (default: @code{""})
18256 The secret key itself.
18261 @deftp {Data Type} knot-acl-configuration
18262 Data type representing an Access Control List (ACL) configuration.
18263 This type has the following parameters:
18266 @item @code{id} (default: @code{""})
18267 An identifier for ether configuration fields to refer to this key. IDs must be
18268 unique and must not be empty.
18270 @item @code{address} (default: @code{'()})
18271 An ordered list of IP addresses, network subnets, or network ranges represented
18272 with strings. The query must match one of them. Empty value means that
18273 address match is not required.
18275 @item @code{key} (default: @code{'()})
18276 An ordered list of references to keys represented with strings. The string
18277 must match a key ID defined in a @code{knot-key-configuration}. No key means
18278 that a key is not require to match that ACL.
18280 @item @code{action} (default: @code{'()})
18281 An ordered list of actions that are permitted or forbidden by this ACL. Possible
18282 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
18283 and @code{'update}.
18285 @item @code{deny?} (default: @code{#f})
18286 When true, the ACL defines restrictions. Listed actions are forbidden. When
18287 false, listed actions are allowed.
18292 @deftp {Data Type} zone-entry
18293 Data type represnting a record entry in a zone file.
18294 This type has the following parameters:
18297 @item @code{name} (default: @code{"@@"})
18298 The name of the record. @code{"@@"} refers to the origin of the zone. Names
18299 are relative to the origin of the zone. For example, in the @code{example.org}
18300 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
18301 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
18302 refers to @code{ns.example.org}.
18304 @item @code{ttl} (default: @code{""})
18305 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
18307 @item @code{class} (default: @code{"IN"})
18308 The class of the record. Knot currently supports only @code{"IN"} and
18309 partially @code{"CH"}.
18311 @item @code{type} (default: @code{"A"})
18312 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
18313 address), NS (Name Server) and MX (Mail eXchange). Many other types are
18316 @item @code{data} (default: @code{""})
18317 The data contained in the record. For instance an IP address associated with
18318 an A record, or a domain name associated with an NS record. Remember that
18319 domain names are relative to the origin unless they end with a dot.
18324 @deftp {Data Type} zone-file
18325 Data type representing the content of a zone file.
18326 This type has the following parameters:
18329 @item @code{entries} (default: @code{'()})
18330 The list of entries. The SOA record is taken care of, so you don't need to
18331 put it in the list of entries. This list should probably contain an entry
18332 for your primary authoritative DNS server. Other than using a list of entries
18333 directly, you can use @code{define-zone-entries} to define a object containing
18334 the list of entries more easily, that you can later pass to the @code{entries}
18335 field of the @code{zone-file}.
18337 @item @code{origin} (default: @code{""})
18338 The name of your zone. This parameter cannot be empty.
18340 @item @code{ns} (default: @code{"ns"})
18341 The domain of your primary authoritative DNS server. The name is relative to
18342 the origin, unless it ends with a dot. It is mandatory that this primary
18343 DNS server corresponds to an NS record in the zone and that it is associated
18344 to an IP address in the list of entries.
18346 @item @code{mail} (default: @code{"hostmaster"})
18347 An email address people can contact you at, as the owner of the zone. This
18348 is translated as @code{<mail>@@<origin>}.
18350 @item @code{serial} (default: @code{1})
18351 The serial number of the zone. As this is used to keep track of changes by
18352 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
18353 Always increment it when you make a change in your zone.
18355 @item @code{refresh} (default: @code{(* 2 24 3600)})
18356 The frequency at which slaves will do a zone transfer. This value is a number
18357 of seconds. It can be computed by multiplications or with
18358 @code{(string->duration)}.
18360 @item @code{retry} (default: @code{(* 15 60)})
18361 The period after which a slave will retry to contact its master when it fails
18362 to do so a first time.
18364 @item @code{expiry} (default: @code{(* 14 24 3600)})
18365 Default TTL of records. Existing records are considered correct for at most
18366 this amount of time. After this period, resolvers will invalidate their cache
18367 and check again that it still exists.
18369 @item @code{nx} (default: @code{3600})
18370 Default TTL of inexistant records. This delay is usually short because you want
18371 your new domains to reach everyone quickly.
18376 @deftp {Data Type} knot-remote-configuration
18377 Data type representing a remote configuration.
18378 This type has the following parameters:
18381 @item @code{id} (default: @code{""})
18382 An identifier for other configuration fields to refer to this remote. IDs must
18383 be unique and must not be empty.
18385 @item @code{address} (default: @code{'()})
18386 An ordered list of destination IP addresses. Addresses are tried in sequence.
18387 An optional port can be given with the @@ separator. For instance:
18388 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
18390 @item @code{via} (default: @code{'()})
18391 An ordered list of source IP addresses. An empty list will have Knot choose
18392 an appropriate source IP. An optional port can be given with the @@ separator.
18393 The default is to choose at random.
18395 @item @code{key} (default: @code{#f})
18396 A reference to a key, that is a string containing the identifier of a key
18397 defined in a @code{knot-key-configuration} field.
18402 @deftp {Data Type} knot-keystore-configuration
18403 Data type representing a keystore to hold dnssec keys.
18404 This type has the following parameters:
18407 @item @code{id} (default: @code{""})
18408 The id of the keystore. It must not be empty.
18410 @item @code{backend} (default: @code{'pem})
18411 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
18413 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
18414 The configuration string of the backend. An example for the PKCS#11 is:
18415 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
18416 For the pem backend, the string reprensents a path in the file system.
18421 @deftp {Data Type} knot-policy-configuration
18422 Data type representing a dnssec policy. Knot DNS is able to automatically
18423 sign your zones. It can either generate and manage your keys automatically or
18424 use keys that you generate.
18426 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
18427 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
18428 zone. In order to be trusted, the KSK needs to be present in the parent zone
18429 (usually a top-level domain). If your registrar supports dnssec, you will
18430 have to send them your KSK's hash so they can add a DS record in their zone.
18431 This is not automated and need to be done each time you change your KSK.
18433 The policy also defines the lifetime of keys. Usually, ZSK can be changed
18434 easily and use weaker cryptographic functions (they use lower parameters) in
18435 order to sign records quickly, so they are changed often. The KSK however
18436 requires manual interaction with the registrar, so they are changed less often
18437 and use stronger parameters because they sign only one record.
18439 This type has the following parameters:
18442 @item @code{id} (default: @code{""})
18443 The id of the policy. It must not be empty.
18445 @item @code{keystore} (default: @code{"default"})
18446 A reference to a keystore, that is a string containing the identifier of a
18447 keystore defined in a @code{knot-keystore-configuration} field. The
18448 @code{"default"} identifier means the default keystore (a kasp database that
18449 was setup by this service).
18451 @item @code{manual?} (default: @code{#f})
18452 Whether the key management is manual or automatic.
18454 @item @code{single-type-signing?} (default: @code{#f})
18455 When @code{#t}, use the Single-Type Signing Scheme.
18457 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
18458 An algorithm of signing keys and issued signatures.
18460 @item @code{ksk-size} (default: @code{256})
18461 The length of the KSK. Note that this value is correct for the default
18462 algorithm, but would be unsecure for other algorithms.
18464 @item @code{zsk-size} (default: @code{256})
18465 The length of the ZSK. Note that this value is correct for the default
18466 algorithm, but would be unsecure for other algorithms.
18468 @item @code{dnskey-ttl} (default: @code{'default})
18469 The TTL value for DNSKEY records added into zone apex. The special
18470 @code{'default} value means same as the zone SOA TTL.
18472 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
18473 The period between ZSK publication and the next rollover initiation.
18475 @item @code{propagation-delay} (default: @code{(* 24 3600)})
18476 An extra delay added for each key rollover step. This value should be high
18477 enough to cover propagation of data from the master server to all slaves.
18479 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
18480 A validity period of newly issued signatures.
18482 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
18483 A period how long before a signature expiration the signature will be refreshed.
18485 @item @code{nsec3?} (default: @code{#f})
18486 When @code{#t}, NSEC3 will be used instead of NSEC.
18488 @item @code{nsec3-iterations} (default: @code{5})
18489 The number of additional times the hashing is performed.
18491 @item @code{nsec3-salt-length} (default: @code{8})
18492 The length of a salt field in octets, which is appended to the original owner
18493 name before hashing.
18495 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
18496 The validity period of newly issued salt field.
18501 @deftp {Data Type} knot-zone-configuration
18502 Data type representing a zone served by Knot.
18503 This type has the following parameters:
18506 @item @code{domain} (default: @code{""})
18507 The domain served by this configuration. It must not be empty.
18509 @item @code{file} (default: @code{""})
18510 The file where this zone is saved. This parameter is ignored by master zones.
18511 Empty means default location that depends on the domain name.
18513 @item @code{zone} (default: @code{(zone-file)})
18514 The content of the zone file. This parameter is ignored by slave zones. It
18515 must contain a zone-file record.
18517 @item @code{master} (default: @code{'()})
18518 A list of master remotes. When empty, this zone is a master. When set, this
18519 zone is a slave. This is a list of remotes identifiers.
18521 @item @code{ddns-master} (default: @code{#f})
18522 The main master. When empty, it defaults to the first master in the list of
18525 @item @code{notify} (default: @code{'()})
18526 A list of slave remote identifiers.
18528 @item @code{acl} (default: @code{'()})
18529 A list of acl identifiers.
18531 @item @code{semantic-checks?} (default: @code{#f})
18532 When set, this adds more semantic checks to the zone.
18534 @item @code{disable-any?} (default: @code{#f})
18535 When set, this forbids queries of the ANY type.
18537 @item @code{zonefile-sync} (default: @code{0})
18538 The delay between a modification in memory and on disk. 0 means immediate
18541 @item @code{serial-policy} (default: @code{'increment})
18542 A policy between @code{'increment} and @code{'unixtime}.
18547 @deftp {Data Type} knot-configuration
18548 Data type representing the Knot configuration.
18549 This type has the following parameters:
18552 @item @code{knot} (default: @code{knot})
18555 @item @code{run-directory} (default: @code{"/var/run/knot"})
18556 The run directory. This directory will be used for pid file and sockets.
18558 @item @code{listen-v4} (default: @code{"0.0.0.0"})
18559 An ip address on which to listen.
18561 @item @code{listen-v6} (default: @code{"::"})
18562 An ip address on which to listen.
18564 @item @code{listen-port} (default: @code{53})
18565 A port on which to listen.
18567 @item @code{keys} (default: @code{'()})
18568 The list of knot-key-configuration used by this configuration.
18570 @item @code{acls} (default: @code{'()})
18571 The list of knot-acl-configuration used by this configuration.
18573 @item @code{remotes} (default: @code{'()})
18574 The list of knot-remote-configuration used by this configuration.
18576 @item @code{zones} (default: @code{'()})
18577 The list of knot-zone-configuration used by this configuration.
18582 @subsubheading Dnsmasq Service
18584 @deffn {Scheme Variable} dnsmasq-service-type
18585 This is the type of the dnsmasq service, whose value should be an
18586 @code{dnsmasq-configuration} object as in this example:
18589 (service dnsmasq-service-type
18590 (dnsmasq-configuration
18592 (servers '("192.168.1.1"))))
18596 @deftp {Data Type} dnsmasq-configuration
18597 Data type representing the configuration of dnsmasq.
18600 @item @code{package} (default: @var{dnsmasq})
18601 Package object of the dnsmasq server.
18603 @item @code{no-hosts?} (default: @code{#f})
18604 When true, don't read the hostnames in /etc/hosts.
18606 @item @code{port} (default: @code{53})
18607 The port to listen on. Setting this to zero completely disables DNS
18608 responses, leaving only DHCP and/or TFTP functions.
18610 @item @code{local-service?} (default: @code{#t})
18611 Accept DNS queries only from hosts whose address is on a local subnet,
18612 ie a subnet for which an interface exists on the server.
18614 @item @code{listen-addresses} (default: @code{'()})
18615 Listen on the given IP addresses.
18617 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
18618 The file to read the IP address of the upstream nameservers from.
18620 @item @code{no-resolv?} (default: @code{#f})
18621 When true, don't read @var{resolv-file}.
18623 @item @code{servers} (default: @code{'()})
18624 Specify IP address of upstream servers directly.
18626 @item @code{cache-size} (default: @code{150})
18627 Set the size of dnsmasq's cache. Setting the cache size to zero
18630 @item @code{negative-cache?} (default: @code{#t})
18631 When false, disable negative caching.
18636 @subsubheading ddclient Service
18639 The ddclient service described below runs the ddclient daemon, which takes
18640 care of automatically updating DNS entries for service providers such as
18641 @uref{https://dyn.com/dns/, Dyn}.
18643 The following example show instantiates the service with its default
18647 (service ddclient-service-type)
18650 Note that ddclient needs to access credentials that are stored in a
18651 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
18652 @code{secret-file} below.) You are expected to create this file manually, in
18653 an ``out-of-band'' fashion (you @emph{could} make this file part of the
18654 service configuration, for instance by using @code{plain-file}, but it will be
18655 world-readable @i{via} @file{/gnu/store}.) See the examples in the
18656 @file{share/ddclient} directory of the @code{ddclient} package.
18658 @c %start of fragment
18660 Available @code{ddclient-configuration} fields are:
18662 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
18663 The ddclient package.
18667 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
18668 The period after which ddclient will retry to check IP and domain name.
18670 Defaults to @samp{300}.
18674 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
18675 Use syslog for the output.
18677 Defaults to @samp{#t}.
18681 @deftypevr {@code{ddclient-configuration} parameter} string mail
18684 Defaults to @samp{"root"}.
18688 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
18689 Mail failed update to user.
18691 Defaults to @samp{"root"}.
18695 @deftypevr {@code{ddclient-configuration} parameter} string pid
18696 The ddclient PID file.
18698 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
18702 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
18703 Enable SSL support.
18705 Defaults to @samp{#t}.
18709 @deftypevr {@code{ddclient-configuration} parameter} string user
18710 Specifies the user name or ID that is used when running ddclient
18713 Defaults to @samp{"ddclient"}.
18717 @deftypevr {@code{ddclient-configuration} parameter} string group
18718 Group of the user who will run the ddclient program.
18720 Defaults to @samp{"ddclient"}.
18724 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
18725 Secret file which will be appended to @file{ddclient.conf} file. This
18726 file contains credentials for use by ddclient. You are expected to
18727 create it manually.
18729 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
18733 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
18734 Extra options will be appended to @file{ddclient.conf} file.
18736 Defaults to @samp{()}.
18741 @c %end of fragment
18745 @subsection VPN Services
18746 @cindex VPN (virtual private network)
18747 @cindex virtual private network (VPN)
18749 The @code{(gnu services vpn)} module provides services related to
18750 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
18751 your machine to connect to a VPN, and a @emph{servire} service for your machine
18752 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
18754 @deffn {Scheme Procedure} openvpn-client-service @
18755 [#:config (openvpn-client-configuration)]
18757 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
18760 @deffn {Scheme Procedure} openvpn-server-service @
18761 [#:config (openvpn-server-configuration)]
18763 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
18765 Both can be run simultaneously.
18768 @c %automatically generated documentation
18770 Available @code{openvpn-client-configuration} fields are:
18772 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
18773 The OpenVPN package.
18777 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
18778 The OpenVPN pid file.
18780 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
18784 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
18785 The protocol (UDP or TCP) used to open a channel between clients and
18788 Defaults to @samp{udp}.
18792 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
18793 The device type used to represent the VPN connection.
18795 Defaults to @samp{tun}.
18799 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
18800 The certificate authority to check connections against.
18802 Defaults to @samp{"/etc/openvpn/ca.crt"}.
18806 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
18807 The certificate of the machine the daemon is running on. It should be
18808 signed by the authority given in @code{ca}.
18810 Defaults to @samp{"/etc/openvpn/client.crt"}.
18814 @deftypevr {@code{openvpn-client-configuration} parameter} string key
18815 The key of the machine the daemon is running on. It must be the key whose
18816 certificate is @code{cert}.
18818 Defaults to @samp{"/etc/openvpn/client.key"}.
18822 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
18823 Whether to use the lzo compression algorithm.
18825 Defaults to @samp{#t}.
18829 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
18830 Don't re-read key files across SIGUSR1 or --ping-restart.
18832 Defaults to @samp{#t}.
18836 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
18837 Don't close and reopen TUN/TAP device or run up/down scripts across
18838 SIGUSR1 or --ping-restart restarts.
18840 Defaults to @samp{#t}.
18844 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
18847 Defaults to @samp{3}.
18851 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
18852 Add an additional layer of HMAC authentication on top of the TLS control
18853 channel to protect against DoS attacks.
18855 Defaults to @samp{#f}.
18859 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
18860 Whether to check the server certificate has server usage extension.
18862 Defaults to @samp{#t}.
18866 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
18867 Bind to a specific local port number.
18869 Defaults to @samp{#f}.
18873 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
18874 Retry resolving server address.
18876 Defaults to @samp{#t}.
18880 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
18881 A list of remote servers to connect to.
18883 Defaults to @samp{()}.
18885 Available @code{openvpn-remote-configuration} fields are:
18887 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
18890 Defaults to @samp{"my-server"}.
18894 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
18895 Port number the server listens to.
18897 Defaults to @samp{1194}.
18902 @c %end of automatic openvpn-client documentation
18904 @c %automatically generated documentation
18906 Available @code{openvpn-server-configuration} fields are:
18908 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
18909 The OpenVPN package.
18913 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
18914 The OpenVPN pid file.
18916 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
18920 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
18921 The protocol (UDP or TCP) used to open a channel between clients and
18924 Defaults to @samp{udp}.
18928 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
18929 The device type used to represent the VPN connection.
18931 Defaults to @samp{tun}.
18935 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
18936 The certificate authority to check connections against.
18938 Defaults to @samp{"/etc/openvpn/ca.crt"}.
18942 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
18943 The certificate of the machine the daemon is running on. It should be
18944 signed by the authority given in @code{ca}.
18946 Defaults to @samp{"/etc/openvpn/client.crt"}.
18950 @deftypevr {@code{openvpn-server-configuration} parameter} string key
18951 The key of the machine the daemon is running on. It must be the key whose
18952 certificate is @code{cert}.
18954 Defaults to @samp{"/etc/openvpn/client.key"}.
18958 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
18959 Whether to use the lzo compression algorithm.
18961 Defaults to @samp{#t}.
18965 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
18966 Don't re-read key files across SIGUSR1 or --ping-restart.
18968 Defaults to @samp{#t}.
18972 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
18973 Don't close and reopen TUN/TAP device or run up/down scripts across
18974 SIGUSR1 or --ping-restart restarts.
18976 Defaults to @samp{#t}.
18980 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
18983 Defaults to @samp{3}.
18987 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
18988 Add an additional layer of HMAC authentication on top of the TLS control
18989 channel to protect against DoS attacks.
18991 Defaults to @samp{#f}.
18995 @deftypevr {@code{openvpn-server-configuration} parameter} number port
18996 Specifies the port number on which the server listens.
18998 Defaults to @samp{1194}.
19002 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
19003 An ip and mask specifying the subnet inside the virtual network.
19005 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
19009 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
19010 A CIDR notation specifying the IPv6 subnet inside the virtual network.
19012 Defaults to @samp{#f}.
19016 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
19017 The Diffie-Hellman parameters file.
19019 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
19023 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
19024 The file that records client IPs.
19026 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
19030 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
19031 When true, the server will act as a gateway for its clients.
19033 Defaults to @samp{#f}.
19037 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
19038 When true, clients are allowed to talk to each other inside the VPN.
19040 Defaults to @samp{#f}.
19044 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
19045 Causes ping-like messages to be sent back and forth over the link so
19046 that each side knows when the other side has gone down. @code{keepalive}
19047 requires a pair. The first element is the period of the ping sending,
19048 and the second element is the timeout before considering the other side
19053 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
19054 The maximum number of clients.
19056 Defaults to @samp{100}.
19060 @deftypevr {@code{openvpn-server-configuration} parameter} string status
19061 The status file. This file shows a small report on current connection.
19062 It is truncated and rewritten every minute.
19064 Defaults to @samp{"/var/run/openvpn/status"}.
19068 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
19069 The list of configuration for some clients.
19071 Defaults to @samp{()}.
19073 Available @code{openvpn-ccd-configuration} fields are:
19075 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
19078 Defaults to @samp{"client"}.
19082 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
19085 Defaults to @samp{#f}.
19089 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
19092 Defaults to @samp{#f}.
19099 @c %end of automatic openvpn-server documentation
19102 @node Network File System
19103 @subsection Network File System
19106 The @code{(gnu services nfs)} module provides the following services,
19107 which are most commonly used in relation to mounting or exporting
19108 directory trees as @dfn{network file systems} (NFS).
19110 @subsubheading RPC Bind Service
19113 The RPC Bind service provides a facility to map program numbers into
19114 universal addresses.
19115 Many NFS related services use this facility. Hence it is automatically
19116 started when a dependent service starts.
19118 @defvr {Scheme Variable} rpcbind-service-type
19119 A service type for the RPC portmapper daemon.
19123 @deftp {Data Type} rpcbind-configuration
19124 Data type representing the configuration of the RPC Bind Service.
19125 This type has the following parameters:
19127 @item @code{rpcbind} (default: @code{rpcbind})
19128 The rpcbind package to use.
19130 @item @code{warm-start?} (default: @code{#t})
19131 If this parameter is @code{#t}, then the daemon will read a
19132 state file on startup thus reloading state information saved by a previous
19138 @subsubheading Pipefs Pseudo File System
19142 The pipefs file system is used to transfer NFS related data
19143 between the kernel and user space programs.
19145 @defvr {Scheme Variable} pipefs-service-type
19146 A service type for the pipefs pseudo file system.
19149 @deftp {Data Type} pipefs-configuration
19150 Data type representing the configuration of the pipefs pseudo file system service.
19151 This type has the following parameters:
19153 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
19154 The directory to which the file system is to be attached.
19159 @subsubheading GSS Daemon Service
19162 @cindex global security system
19164 The @dfn{global security system} (GSS) daemon provides strong security for RPC
19166 Before exchanging RPC requests an RPC client must establish a security
19167 context. Typically this is done using the Kerberos command @command{kinit}
19168 or automatically at login time using PAM services (@pxref{Kerberos Services}).
19170 @defvr {Scheme Variable} gss-service-type
19171 A service type for the Global Security System (GSS) daemon.
19174 @deftp {Data Type} gss-configuration
19175 Data type representing the configuration of the GSS daemon service.
19176 This type has the following parameters:
19178 @item @code{nfs-utils} (default: @code{nfs-utils})
19179 The package in which the @command{rpc.gssd} command is to be found.
19181 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
19182 The directory where the pipefs file system is mounted.
19188 @subsubheading IDMAP Daemon Service
19190 @cindex name mapper
19192 The idmap daemon service provides mapping between user IDs and user names.
19193 Typically it is required in order to access file systems mounted via NFSv4.
19195 @defvr {Scheme Variable} idmap-service-type
19196 A service type for the Identity Mapper (IDMAP) daemon.
19199 @deftp {Data Type} idmap-configuration
19200 Data type representing the configuration of the IDMAP daemon service.
19201 This type has the following parameters:
19203 @item @code{nfs-utils} (default: @code{nfs-utils})
19204 The package in which the @command{rpc.idmapd} command is to be found.
19206 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
19207 The directory where the pipefs file system is mounted.
19209 @item @code{domain} (default: @code{#f})
19210 The local NFSv4 domain name.
19211 This must be a string or @code{#f}.
19212 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
19217 @node Continuous Integration
19218 @subsection Continuous Integration
19220 @cindex continuous integration
19221 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
19222 continuous integration tool for Guix. It can be used both for development and
19223 for providing substitutes to others (@pxref{Substitutes}).
19225 The @code{(gnu services cuirass)} module provides the following service.
19227 @defvr {Scheme Procedure} cuirass-service-type
19228 The type of the Cuirass service. Its value must be a
19229 @code{cuirass-configuration} object, as described below.
19232 To add build jobs, you have to set the @code{specifications} field of the
19233 configuration. Here is an example of a service that polls the Guix repository
19234 and builds the packages from a manifest. Some of the packages are defined in
19235 the @code{"custom-packages"} input, which is the equivalent of
19236 @code{GUIX_PACKAGE_PATH}.
19239 (define %cuirass-specs
19241 '((#:name . "my-manifest")
19242 (#:load-path-inputs . ("guix"))
19243 (#:package-path-inputs . ("custom-packages"))
19244 (#:proc-input . "guix")
19245 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
19246 (#:proc . cuirass-jobs)
19247 (#:proc-args . ((subset . "manifests")
19248 (systems . ("x86_64-linux"))
19249 (manifests . (("config" . "guix/manifest.scm")))))
19250 (#:inputs . (((#:name . "guix")
19251 (#:url . "git://git.savannah.gnu.org/guix.git")
19252 (#:load-path . ".")
19253 (#:branch . "master")
19254 (#:no-compile? . #t))
19255 ((#:name . "config")
19256 (#:url . "git://git.example.org/config.git")
19257 (#:load-path . ".")
19258 (#:branch . "master")
19259 (#:no-compile? . #t))
19260 ((#:name . "custom-packages")
19261 (#:url . "git://git.example.org/custom-packages.git")
19262 (#:load-path . ".")
19263 (#:branch . "master")
19264 (#:no-compile? . #t)))))))
19266 (service cuirass-service-type
19267 (cuirass-configuration
19268 (specifications %cuirass-specs)))
19271 While information related to build jobs is located directly in the
19272 specifications, global settings for the @command{cuirass} process are
19273 accessible in other @code{cuirass-configuration} fields.
19275 @deftp {Data Type} cuirass-configuration
19276 Data type representing the configuration of Cuirass.
19279 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
19280 Location of the log file.
19282 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
19283 Location of the repository cache.
19285 @item @code{user} (default: @code{"cuirass"})
19286 Owner of the @code{cuirass} process.
19288 @item @code{group} (default: @code{"cuirass"})
19289 Owner's group of the @code{cuirass} process.
19291 @item @code{interval} (default: @code{60})
19292 Number of seconds between the poll of the repositories followed by the
19295 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
19296 Location of sqlite database which contains the build results and previously
19297 added specifications.
19299 @item @code{ttl} (default: @code{(* 30 24 3600)})
19300 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
19301 are registered for build results. This means that build results are protected
19302 from garbage collection for at least @var{ttl} seconds.
19304 @item @code{port} (default: @code{8081})
19305 Port number used by the HTTP server.
19307 @item --listen=@var{host}
19308 Listen on the network interface for @var{host}. The default is to
19309 accept connections from localhost.
19311 @item @code{specifications} (default: @code{#~'()})
19312 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
19313 where a specification is an association list
19314 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
19315 keys are keywords (@code{#:keyword-example}) as shown in the example
19318 @item @code{use-substitutes?} (default: @code{#f})
19319 This allows using substitutes to avoid building every dependencies of a job
19322 @item @code{one-shot?} (default: @code{#f})
19323 Only evaluate specifications and build derivations once.
19325 @item @code{fallback?} (default: @code{#f})
19326 When substituting a pre-built binary fails, fall back to building
19329 @item @code{cuirass} (default: @code{cuirass})
19330 The Cuirass package to use.
19334 @node Power Management Services
19335 @subsection Power Management Services
19338 @cindex power management with TLP
19339 @subsubheading TLP daemon
19341 The @code{(gnu services pm)} module provides a Guix service definition
19342 for the Linux power management tool TLP.
19344 TLP enables various powersaving modes in userspace and kernel.
19345 Contrary to @code{upower-service}, it is not a passive,
19346 monitoring tool, as it will apply custom settings each time a new power
19347 source is detected. More information can be found at
19348 @uref{http://linrunner.de/en/tlp/tlp.html, TLP home page}.
19350 @deffn {Scheme Variable} tlp-service-type
19351 The service type for the TLP tool. Its value should be a valid
19352 TLP configuration (see below). To use the default settings, simply
19355 (service tlp-service-type)
19359 By default TLP does not need much configuration but most TLP parameters
19360 can be tweaked using @code{tlp-configuration}.
19362 Each parameter definition is preceded by its type; for example,
19363 @samp{boolean foo} indicates that the @code{foo} parameter
19364 should be specified as a boolean. Types starting with
19365 @code{maybe-} denote parameters that won't show up in TLP config file
19366 when their value is @code{'disabled}.
19368 @c The following documentation was initially generated by
19369 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
19370 @c documentation is better, so we shouldn't hesitate to edit below as
19371 @c needed. However if the change you want to make to this documentation
19372 @c can be done in an automated way, it's probably easier to change
19373 @c (generate-documentation) than to make it below and have to deal with
19374 @c the churn as TLP updates.
19376 Available @code{tlp-configuration} fields are:
19378 @deftypevr {@code{tlp-configuration} parameter} package tlp
19383 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
19384 Set to true if you wish to enable TLP.
19386 Defaults to @samp{#t}.
19390 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
19391 Default mode when no power supply can be detected. Alternatives are AC
19394 Defaults to @samp{"AC"}.
19398 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
19399 Number of seconds Linux kernel has to wait after the disk goes idle,
19400 before syncing on AC.
19402 Defaults to @samp{0}.
19406 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
19407 Same as @code{disk-idle-ac} but on BAT mode.
19409 Defaults to @samp{2}.
19413 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
19414 Dirty pages flushing periodicity, expressed in seconds.
19416 Defaults to @samp{15}.
19420 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
19421 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
19423 Defaults to @samp{60}.
19427 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
19428 CPU frequency scaling governor on AC mode. With intel_pstate driver,
19429 alternatives are powersave and performance. With acpi-cpufreq driver,
19430 alternatives are ondemand, powersave, performance and conservative.
19432 Defaults to @samp{disabled}.
19436 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
19437 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
19439 Defaults to @samp{disabled}.
19443 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
19444 Set the min available frequency for the scaling governor on AC.
19446 Defaults to @samp{disabled}.
19450 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
19451 Set the max available frequency for the scaling governor on AC.
19453 Defaults to @samp{disabled}.
19457 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
19458 Set the min available frequency for the scaling governor on BAT.
19460 Defaults to @samp{disabled}.
19464 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
19465 Set the max available frequency for the scaling governor on BAT.
19467 Defaults to @samp{disabled}.
19471 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
19472 Limit the min P-state to control the power dissipation of the CPU, in AC
19473 mode. Values are stated as a percentage of the available performance.
19475 Defaults to @samp{disabled}.
19479 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
19480 Limit the max P-state to control the power dissipation of the CPU, in AC
19481 mode. Values are stated as a percentage of the available performance.
19483 Defaults to @samp{disabled}.
19487 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
19488 Same as @code{cpu-min-perf-on-ac} on BAT mode.
19490 Defaults to @samp{disabled}.
19494 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
19495 Same as @code{cpu-max-perf-on-ac} on BAT mode.
19497 Defaults to @samp{disabled}.
19501 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
19502 Enable CPU turbo boost feature on AC mode.
19504 Defaults to @samp{disabled}.
19508 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
19509 Same as @code{cpu-boost-on-ac?} on BAT mode.
19511 Defaults to @samp{disabled}.
19515 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
19516 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
19517 used under light load conditions.
19519 Defaults to @samp{#f}.
19523 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
19524 Same as @code{sched-powersave-on-ac?} but on BAT mode.
19526 Defaults to @samp{#t}.
19530 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
19531 Enable Linux kernel NMI watchdog.
19533 Defaults to @samp{#f}.
19537 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
19538 For Linux kernels with PHC patch applied, change CPU voltages. An
19539 example value would be @samp{"F:V F:V F:V F:V"}.
19541 Defaults to @samp{disabled}.
19545 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
19546 Set CPU performance versus energy saving policy on AC. Alternatives are
19547 performance, normal, powersave.
19549 Defaults to @samp{"performance"}.
19553 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
19554 Same as @code{energy-perf-policy-ac} but on BAT mode.
19556 Defaults to @samp{"powersave"}.
19560 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
19565 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
19566 Hard disk advanced power management level.
19570 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
19571 Same as @code{disk-apm-bat} but on BAT mode.
19575 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
19576 Hard disk spin down timeout. One value has to be specified for each
19577 declared hard disk.
19579 Defaults to @samp{disabled}.
19583 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
19584 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
19586 Defaults to @samp{disabled}.
19590 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
19591 Select IO scheduler for disk devices. One value has to be specified for
19592 each declared hard disk. Example alternatives are cfq, deadline and
19595 Defaults to @samp{disabled}.
19599 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
19600 SATA aggressive link power management (ALPM) level. Alternatives are
19601 min_power, medium_power, max_performance.
19603 Defaults to @samp{"max_performance"}.
19607 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
19608 Same as @code{sata-linkpwr-ac} but on BAT mode.
19610 Defaults to @samp{"min_power"}.
19614 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
19615 Exclude specified SATA host devices for link power management.
19617 Defaults to @samp{disabled}.
19621 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
19622 Enable Runtime Power Management for AHCI controller and disks on AC
19625 Defaults to @samp{disabled}.
19629 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
19630 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
19632 Defaults to @samp{disabled}.
19636 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
19637 Seconds of inactivity before disk is suspended.
19639 Defaults to @samp{15}.
19643 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
19644 PCI Express Active State Power Management level. Alternatives are
19645 default, performance, powersave.
19647 Defaults to @samp{"performance"}.
19651 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
19652 Same as @code{pcie-aspm-ac} but on BAT mode.
19654 Defaults to @samp{"powersave"}.
19658 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
19659 Radeon graphics clock speed level. Alternatives are low, mid, high,
19662 Defaults to @samp{"high"}.
19666 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
19667 Same as @code{radeon-power-ac} but on BAT mode.
19669 Defaults to @samp{"low"}.
19673 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
19674 Radeon dynamic power management method (DPM). Alternatives are battery,
19677 Defaults to @samp{"performance"}.
19681 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
19682 Same as @code{radeon-dpm-state-ac} but on BAT mode.
19684 Defaults to @samp{"battery"}.
19688 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
19689 Radeon DPM performance level. Alternatives are auto, low, high.
19691 Defaults to @samp{"auto"}.
19695 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
19696 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
19698 Defaults to @samp{"auto"}.
19702 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
19703 Wifi power saving mode.
19705 Defaults to @samp{#f}.
19709 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
19710 Same as @code{wifi-power-ac?} but on BAT mode.
19712 Defaults to @samp{#t}.
19716 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
19717 Disable wake on LAN.
19719 Defaults to @samp{#t}.
19723 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
19724 Timeout duration in seconds before activating audio power saving on
19725 Intel HDA and AC97 devices. A value of 0 disables power saving.
19727 Defaults to @samp{0}.
19731 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
19732 Same as @code{sound-powersave-ac} but on BAT mode.
19734 Defaults to @samp{1}.
19738 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
19739 Disable controller in powersaving mode on Intel HDA devices.
19741 Defaults to @samp{#t}.
19745 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
19746 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
19747 powered on again by releasing (and reinserting) the eject lever or by
19748 pressing the disc eject button on newer models.
19750 Defaults to @samp{#f}.
19754 @deftypevr {@code{tlp-configuration} parameter} string bay-device
19755 Name of the optical drive device to power off.
19757 Defaults to @samp{"sr0"}.
19761 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
19762 Runtime Power Management for PCI(e) bus devices. Alternatives are on
19765 Defaults to @samp{"on"}.
19769 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
19770 Same as @code{runtime-pm-ac} but on BAT mode.
19772 Defaults to @samp{"auto"}.
19776 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
19777 Runtime Power Management for all PCI(e) bus devices, except blacklisted
19780 Defaults to @samp{#t}.
19784 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
19785 Exclude specified PCI(e) device addresses from Runtime Power Management.
19787 Defaults to @samp{disabled}.
19791 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
19792 Exclude PCI(e) devices assigned to the specified drivers from Runtime
19797 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
19798 Enable USB autosuspend feature.
19800 Defaults to @samp{#t}.
19804 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
19805 Exclude specified devices from USB autosuspend.
19807 Defaults to @samp{disabled}.
19811 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
19812 Exclude WWAN devices from USB autosuspend.
19814 Defaults to @samp{#t}.
19818 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
19819 Include specified devices into USB autosuspend, even if they are already
19820 excluded by the driver or via @code{usb-blacklist-wwan?}.
19822 Defaults to @samp{disabled}.
19826 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
19827 Enable USB autosuspend before shutdown.
19829 Defaults to @samp{disabled}.
19833 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
19834 Restore radio device state (bluetooth, wifi, wwan) from previous
19835 shutdown on system startup.
19837 Defaults to @samp{#f}.
19842 @cindex CPU frequency scaling with thermald
19843 @subsubheading Thermald daemon
19845 The @code{(gnu services pm)} module provides an interface to
19846 thermald, a CPU frequency scaling service which helps prevent overheating.
19848 @defvr {Scheme Variable} thermald-service-type
19849 This is the service type for
19850 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
19851 Thermal Daemon, which is responsible for controlling the thermal state
19852 of processors and preventing overheating.
19855 @deftp {Data Type} thermald-configuration
19856 Data type representing the configuration of @code{thermald-service-type}.
19859 @item @code{ignore-cpuid-check?} (default: @code{#f})
19860 Ignore cpuid check for supported CPU models.
19862 @item @code{thermald} (default: @var{thermald})
19863 Package object of thermald.
19868 @node Audio Services
19869 @subsection Audio Services
19871 The @code{(gnu services audio)} module provides a service to start MPD
19872 (the Music Player Daemon).
19875 @subsubheading Music Player Daemon
19877 The Music Player Daemon (MPD) is a service that can play music while
19878 being controlled from the local machine or over the network by a variety
19881 The following example shows how one might run @code{mpd} as user
19882 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
19885 (service mpd-service-type
19891 @defvr {Scheme Variable} mpd-service-type
19892 The service type for @command{mpd}
19895 @deftp {Data Type} mpd-configuration
19896 Data type representing the configuration of @command{mpd}.
19899 @item @code{user} (default: @code{"mpd"})
19900 The user to run mpd as.
19902 @item @code{music-dir} (default: @code{"~/Music"})
19903 The directory to scan for music files.
19905 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
19906 The directory to store playlists.
19908 @item @code{port} (default: @code{"6600"})
19909 The port to run mpd on.
19911 @item @code{address} (default: @code{"any"})
19912 The address that mpd will bind to. To use a Unix domain socket,
19913 an absolute path can be specified here.
19918 @node Virtualization Services
19919 @subsection Virtualization services
19921 The @code{(gnu services virtualization)} module provides services for
19922 the libvirt and virtlog daemons, as well as other virtualization-related
19925 @subsubheading Libvirt daemon
19926 @code{libvirtd} is the server side daemon component of the libvirt
19927 virtualization management system. This daemon runs on host servers
19928 and performs required management tasks for virtualized guests.
19930 @deffn {Scheme Variable} libvirt-service-type
19931 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
19932 Its value must be a @code{libvirt-configuration}.
19935 (service libvirt-service-type
19936 (libvirt-configuration
19937 (unix-sock-group "libvirt")
19938 (tls-port "16555")))
19942 @c Auto-generated with (generate-libvirt-documentation)
19943 Available @code{libvirt-configuration} fields are:
19945 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
19950 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
19951 Flag listening for secure TLS connections on the public TCP/IP port.
19952 must set @code{listen} for this to have any effect.
19954 It is necessary to setup a CA and issue server certificates before using
19957 Defaults to @samp{#t}.
19961 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
19962 Listen for unencrypted TCP connections on the public TCP/IP port. must
19963 set @code{listen} for this to have any effect.
19965 Using the TCP socket requires SASL authentication by default. Only SASL
19966 mechanisms which support data encryption are allowed. This is
19967 DIGEST_MD5 and GSSAPI (Kerberos5)
19969 Defaults to @samp{#f}.
19973 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
19974 Port for accepting secure TLS connections This can be a port number, or
19977 Defaults to @samp{"16514"}.
19981 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
19982 Port for accepting insecure TCP connections This can be a port number,
19985 Defaults to @samp{"16509"}.
19989 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
19990 IP address or hostname used for client connections.
19992 Defaults to @samp{"0.0.0.0"}.
19996 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
19997 Flag toggling mDNS advertisement of the libvirt service.
19999 Alternatively can disable for all services on a host by stopping the
20002 Defaults to @samp{#f}.
20006 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
20007 Default mDNS advertisement name. This must be unique on the immediate
20010 Defaults to @samp{"Virtualization Host <hostname>"}.
20014 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
20015 UNIX domain socket group ownership. This can be used to allow a
20016 'trusted' set of users access to management capabilities without
20019 Defaults to @samp{"root"}.
20023 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
20024 UNIX socket permissions for the R/O socket. This is used for monitoring
20027 Defaults to @samp{"0777"}.
20031 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
20032 UNIX socket permissions for the R/W socket. Default allows only root.
20033 If PolicyKit is enabled on the socket, the default will change to allow
20034 everyone (eg, 0777)
20036 Defaults to @samp{"0770"}.
20040 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
20041 UNIX socket permissions for the admin socket. Default allows only owner
20042 (root), do not change it unless you are sure to whom you are exposing
20045 Defaults to @samp{"0777"}.
20049 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
20050 The directory in which sockets will be found/created.
20052 Defaults to @samp{"/var/run/libvirt"}.
20056 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
20057 Authentication scheme for UNIX read-only sockets. By default socket
20058 permissions allow anyone to connect
20060 Defaults to @samp{"polkit"}.
20064 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
20065 Authentication scheme for UNIX read-write sockets. By default socket
20066 permissions only allow root. If PolicyKit support was compiled into
20067 libvirt, the default will be to use 'polkit' auth.
20069 Defaults to @samp{"polkit"}.
20073 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
20074 Authentication scheme for TCP sockets. If you don't enable SASL, then
20075 all TCP traffic is cleartext. Don't do this outside of a dev/test
20078 Defaults to @samp{"sasl"}.
20082 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
20083 Authentication scheme for TLS sockets. TLS sockets already have
20084 encryption provided by the TLS layer, and limited authentication is done
20087 It is possible to make use of any SASL authentication mechanism as well,
20088 by using 'sasl' for this option
20090 Defaults to @samp{"none"}.
20094 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
20095 API access control scheme.
20097 By default an authenticated user is allowed access to all APIs. Access
20098 drivers can place restrictions on this.
20100 Defaults to @samp{()}.
20104 @deftypevr {@code{libvirt-configuration} parameter} string key-file
20105 Server key file path. If set to an empty string, then no private key is
20108 Defaults to @samp{""}.
20112 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
20113 Server key file path. If set to an empty string, then no certificate is
20116 Defaults to @samp{""}.
20120 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
20121 Server key file path. If set to an empty string, then no CA certificate
20124 Defaults to @samp{""}.
20128 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
20129 Certificate revocation list path. If set to an empty string, then no
20132 Defaults to @samp{""}.
20136 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
20137 Disable verification of our own server certificates.
20139 When libvirtd starts it performs some sanity checks against its own
20142 Defaults to @samp{#f}.
20146 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
20147 Disable verification of client certificates.
20149 Client certificate verification is the primary authentication mechanism.
20150 Any client which does not present a certificate signed by the CA will be
20153 Defaults to @samp{#f}.
20157 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
20158 Whitelist of allowed x509 Distinguished Name.
20160 Defaults to @samp{()}.
20164 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
20165 Whitelist of allowed SASL usernames. The format for username depends on
20166 the SASL authentication mechanism.
20168 Defaults to @samp{()}.
20172 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
20173 Override the compile time default TLS priority string. The default is
20174 usually "NORMAL" unless overridden at build time. Only set this is it
20175 is desired for libvirt to deviate from the global default settings.
20177 Defaults to @samp{"NORMAL"}.
20181 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
20182 Maximum number of concurrent client connections to allow over all
20185 Defaults to @samp{5000}.
20189 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
20190 Maximum length of queue of connections waiting to be accepted by the
20191 daemon. Note, that some protocols supporting retransmission may obey
20192 this so that a later reattempt at connection succeeds.
20194 Defaults to @samp{1000}.
20198 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
20199 Maximum length of queue of accepted but not yet authenticated clients.
20200 Set this to zero to turn this feature off
20202 Defaults to @samp{20}.
20206 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
20207 Number of workers to start up initially.
20209 Defaults to @samp{5}.
20213 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
20214 Maximum number of worker threads.
20216 If the number of active clients exceeds @code{min-workers}, then more
20217 threads are spawned, up to max_workers limit. Typically you'd want
20218 max_workers to equal maximum number of clients allowed.
20220 Defaults to @samp{20}.
20224 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
20225 Number of priority workers. If all workers from above pool are stuck,
20226 some calls marked as high priority (notably domainDestroy) can be
20227 executed in this pool.
20229 Defaults to @samp{5}.
20233 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
20234 Total global limit on concurrent RPC calls.
20236 Defaults to @samp{20}.
20240 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
20241 Limit on concurrent requests from a single client connection. To avoid
20242 one client monopolizing the server this should be a small fraction of
20243 the global max_requests and max_workers parameter.
20245 Defaults to @samp{5}.
20249 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
20250 Same as @code{min-workers} but for the admin interface.
20252 Defaults to @samp{1}.
20256 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
20257 Same as @code{max-workers} but for the admin interface.
20259 Defaults to @samp{5}.
20263 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
20264 Same as @code{max-clients} but for the admin interface.
20266 Defaults to @samp{5}.
20270 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
20271 Same as @code{max-queued-clients} but for the admin interface.
20273 Defaults to @samp{5}.
20277 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
20278 Same as @code{max-client-requests} but for the admin interface.
20280 Defaults to @samp{5}.
20284 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
20285 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
20287 Defaults to @samp{3}.
20291 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
20294 A filter allows to select a different logging level for a given category
20295 of logs The format for a filter is one of:
20306 where @code{name} is a string which is matched against the category
20307 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
20308 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
20309 be a substring of the full category name, in order to match multiple
20310 similar categories), the optional "+" prefix tells libvirt to log stack
20311 trace for each message matching name, and @code{x} is the minimal level
20312 where matching messages should be logged:
20329 Multiple filters can be defined in a single filters statement, they just
20330 need to be separated by spaces.
20332 Defaults to @samp{"3:remote 4:event"}.
20336 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
20339 An output is one of the places to save logging information The format
20340 for an output can be:
20344 output goes to stderr
20346 @item x:syslog:name
20347 use syslog for the output and use the given name as the ident
20349 @item x:file:file_path
20350 output to a file, with the given filepath
20353 output to journald logging system
20357 In all case the x prefix is the minimal level, acting as a filter
20374 Multiple outputs can be defined, they just need to be separated by
20377 Defaults to @samp{"3:stderr"}.
20381 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
20382 Allows usage of the auditing subsystem to be altered
20386 0: disable all auditing
20389 1: enable auditing, only if enabled on host
20392 2: enable auditing, and exit if disabled on host.
20396 Defaults to @samp{1}.
20400 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
20401 Send audit messages via libvirt logging infrastructure.
20403 Defaults to @samp{#f}.
20407 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
20408 Host UUID. UUID must not have all digits be the same.
20410 Defaults to @samp{""}.
20414 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
20415 Source to read host UUID.
20419 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
20422 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
20426 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
20429 Defaults to @samp{"smbios"}.
20433 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
20434 A keepalive message is sent to a client after @code{keepalive_interval}
20435 seconds of inactivity to check if the client is still responding. If
20436 set to -1, libvirtd will never send keepalive requests; however clients
20437 can still send them and the daemon will send responses.
20439 Defaults to @samp{5}.
20443 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
20444 Maximum number of keepalive messages that are allowed to be sent to the
20445 client without getting any response before the connection is considered
20448 In other words, the connection is automatically closed approximately
20449 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
20450 the last message received from the client. When @code{keepalive-count}
20451 is set to 0, connections will be automatically closed after
20452 @code{keepalive-interval} seconds of inactivity without sending any
20453 keepalive messages.
20455 Defaults to @samp{5}.
20459 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
20460 Same as above but for admin interface.
20462 Defaults to @samp{5}.
20466 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
20467 Same as above but for admin interface.
20469 Defaults to @samp{5}.
20473 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
20474 Timeout for Open vSwitch calls.
20476 The @code{ovs-vsctl} utility is used for the configuration and its
20477 timeout option is set by default to 5 seconds to avoid potential
20478 infinite waits blocking libvirt.
20480 Defaults to @samp{5}.
20484 @c %end of autogenerated docs
20486 @subsubheading Virtlog daemon
20487 The virtlogd service is a server side daemon component of libvirt that is
20488 used to manage logs from virtual machine consoles.
20490 This daemon is not used directly by libvirt client applications, rather it
20491 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
20492 standalone daemon, the main @code{libvirtd} daemon can be restarted without
20493 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
20494 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
20496 @deffn {Scheme Variable} virtlog-service-type
20497 This is the type of the virtlog daemon.
20498 Its value must be a @code{virtlog-configuration}.
20501 (service virtlog-service-type
20502 (virtlog-configuration
20503 (max-clients 1000)))
20507 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
20508 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
20510 Defaults to @samp{3}.
20514 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
20517 A filter allows to select a different logging level for a given category
20518 of logs The format for a filter is one of:
20529 where @code{name} is a string which is matched against the category
20530 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
20531 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
20532 be a substring of the full category name, in order to match multiple
20533 similar categories), the optional "+" prefix tells libvirt to log stack
20534 trace for each message matching name, and @code{x} is the minimal level
20535 where matching messages should be logged:
20552 Multiple filters can be defined in a single filters statement, they just
20553 need to be separated by spaces.
20555 Defaults to @samp{"3:remote 4:event"}.
20559 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
20562 An output is one of the places to save logging information The format
20563 for an output can be:
20567 output goes to stderr
20569 @item x:syslog:name
20570 use syslog for the output and use the given name as the ident
20572 @item x:file:file_path
20573 output to a file, with the given filepath
20576 output to journald logging system
20580 In all case the x prefix is the minimal level, acting as a filter
20597 Multiple outputs can be defined, they just need to be separated by
20600 Defaults to @samp{"3:stderr"}.
20604 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
20605 Maximum number of concurrent client connections to allow over all
20608 Defaults to @samp{1024}.
20612 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
20613 Maximum file size before rolling over.
20615 Defaults to @samp{2MB}
20619 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
20620 Maximum number of backup files to keep.
20622 Defaults to @samp{3}
20626 @subsubheading Transparent Emulation with QEMU
20629 @cindex @code{binfmt_misc}
20630 @code{qemu-binfmt-service-type} provides support for transparent
20631 emulation of program binaries built for different architectures---e.g.,
20632 it allows you to transparently execute an ARMv7 program on an x86_64
20633 machine. It achieves this by combining the @uref{https://www.qemu.org,
20634 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
20636 @defvr {Scheme Variable} qemu-binfmt-service-type
20637 This is the type of the QEMU/binfmt service for transparent emulation.
20638 Its value must be a @code{qemu-binfmt-configuration} object, which
20639 specifies the QEMU package to use as well as the architecture we want to
20643 (service qemu-binfmt-service-type
20644 (qemu-binfmt-configuration
20645 (platforms (lookup-qemu-platforms "arm" "aarch64" "ppc"))))
20648 In this example, we enable transparent emulation for the ARM and aarch64
20649 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
20650 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
20651 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
20654 @deftp {Data Type} qemu-binfmt-configuration
20655 This is the configuration for the @code{qemu-binfmt} service.
20658 @item @code{platforms} (default: @code{'()})
20659 The list of emulated QEMU platforms. Each item must be a @dfn{platform
20660 object} as returned by @code{lookup-qemu-platforms} (see below).
20662 @item @code{guix-support?} (default: @code{#f})
20663 When it is true, QEMU and all its dependencies are added to the build
20664 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
20665 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
20666 handlers to be used within the build environment, which in turn means
20667 that you can transparently build programs for another architecture.
20669 For example, let's suppose you're on an x86_64 machine and you have this
20673 (service qemu-binfmt-service-type
20674 (qemu-binfmt-configuration
20675 (platforms (lookup-qemu-platforms "arm"))
20676 (guix-support? #t)))
20682 guix build -s armhf-linux inkscape
20686 and it will build Inkscape for ARMv7 @emph{as if it were a native
20687 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
20688 if you'd like to test a package build for an architecture you don't have
20691 @item @code{qemu} (default: @code{qemu})
20692 The QEMU package to use.
20696 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
20697 Return the list of QEMU platform objects corresponding to
20698 @var{platforms}@dots{}. @var{platforms} must be a list of strings
20699 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
20700 @code{"mips64el"}, and so on.
20703 @deffn {Scheme Procedure} qemu-platform? @var{obj}
20704 Return true if @var{obj} is a platform object.
20707 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
20708 Return the name of @var{platform}---a string such as @code{"arm"}.
20711 @node Version Control Services
20712 @subsection Version Control Services
20714 The @code{(gnu services version-control)} module provides a service to
20715 allow remote access to local Git repositories. There are three options:
20716 the @code{git-daemon-service}, which provides access to repositories via
20717 the @code{git://} unsecured TCP-based protocol, extending the
20718 @code{nginx} web server to proxy some requests to
20719 @code{git-http-backend}, or providing a web interface with
20720 @code{cgit-service-type}.
20722 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
20724 Return a service that runs @command{git daemon}, a simple TCP server to
20725 expose repositories over the Git protocol for anonymous access.
20727 The optional @var{config} argument should be a
20728 @code{<git-daemon-configuration>} object, by default it allows read-only
20729 access to exported@footnote{By creating the magic file
20730 "git-daemon-export-ok" in the repository directory.} repositories under
20735 @deftp {Data Type} git-daemon-configuration
20736 Data type representing the configuration for @code{git-daemon-service}.
20739 @item @code{package} (default: @var{git})
20740 Package object of the Git distributed version control system.
20742 @item @code{export-all?} (default: @var{#f})
20743 Whether to allow access for all Git repositories, even if they do not
20744 have the @file{git-daemon-export-ok} file.
20746 @item @code{base-path} (default: @file{/srv/git})
20747 Whether to remap all the path requests as relative to the given path.
20748 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
20749 then if you later try to pull @code{git://example.com/hello.git}, git
20750 daemon will interpret the path as @code{/srv/git/hello.git}.
20752 @item @code{user-path} (default: @var{#f})
20753 Whether to allow @code{~user} notation to be used in requests. When
20754 specified with empty string, requests to @code{git://host/~alice/foo} is
20755 taken as a request to access @code{foo} repository in the home directory
20756 of user @code{alice}. If @var{(user-path "path")} is specified, the
20757 same request is taken as a request to access @code{path/foo} repository
20758 in the home directory of user @code{alice}.
20760 @item @code{listen} (default: @var{'()})
20761 Whether to listen on specific IP addresses or hostnames, defaults to
20764 @item @code{port} (default: @var{#f})
20765 Whether to listen on an alternative port, which defaults to 9418.
20767 @item @code{whitelist} (default: @var{'()})
20768 If not empty, only allow access to this list of directories.
20770 @item @code{extra-options} (default: @var{'()})
20771 Extra options will be passed to @code{git daemon}, please run
20772 @command{man git-daemon} for more information.
20777 The @code{git://} protocol lacks authentication. When you pull from a
20778 repository fetched via @code{git://}, you don't know that the data you
20779 receive was modified is really coming from the specified host, and you
20780 have your connection is subject to eavesdropping. It's better to use an
20781 authenticated and encrypted transport, such as @code{https}. Although Git allows you
20782 to serve repositories using unsophisticated file-based web servers,
20783 there is a faster protocol implemented by the @code{git-http-backend}
20784 program. This program is the back-end of a proper Git web service. It
20785 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
20786 on running the necessary @code{fcgiwrap} daemon.
20788 Guix has a separate configuration data type for serving Git repositories
20791 @deftp {Data Type} git-http-configuration
20792 Data type representing the configuration for @code{git-http-service}.
20795 @item @code{package} (default: @var{git})
20796 Package object of the Git distributed version control system.
20798 @item @code{git-root} (default: @file{/srv/git})
20799 Directory containing the Git repositories to expose to the world.
20801 @item @code{export-all?} (default: @var{#f})
20802 Whether to expose access for all Git repositories in @var{git-root},
20803 even if they do not have the @file{git-daemon-export-ok} file.
20805 @item @code{uri-path} (default: @file{/git/})
20806 Path prefix for Git access. With the default @code{/git/} prefix, this
20807 will map @code{http://@var{server}/git/@var{repo}.git} to
20808 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
20809 with this prefix are not passed on to this Git instance.
20811 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
20812 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
20817 There is no @code{git-http-service-type}, currently; instead you can
20818 create an @code{nginx-location-configuration} from a
20819 @code{git-http-configuration} and then add that location to a web
20822 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
20823 [config=(git-http-configuration)]
20824 Compute an @code{nginx-location-configuration} that corresponds to the
20825 given Git http configuration. An example nginx service definition to
20826 serve the default @file{/srv/git} over HTTPS might be:
20829 (service nginx-service-type
20830 (nginx-configuration
20833 (nginx-server-configuration
20834 (listen '("443 ssl"))
20835 (server-name "git.my-host.org")
20837 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
20838 (ssl-certificate-key
20839 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
20842 (git-http-nginx-location-configuration
20843 (git-http-configuration (uri-path "/"))))))))))
20846 This example assumes that you are using Let's Encrypt to get your TLS
20847 certificate. @xref{Certificate Services}. The default @code{certbot}
20848 service will redirect all HTTP traffic on @code{git.my-host.org} to
20849 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
20850 system services. @xref{Web Services}.
20853 @subsubheading Cgit Service
20855 @cindex Cgit service
20856 @cindex Git, web interface
20857 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
20858 repositories written in C.
20860 The following example will configure the service with default values.
20861 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
20864 (service cgit-service-type)
20867 The @code{file-object} type designates either a file-like object
20868 (@pxref{G-Expressions, file-like objects}) or a string.
20870 @c %start of fragment
20872 Available @code{cgit-configuration} fields are:
20874 @deftypevr {@code{cgit-configuration} parameter} package package
20879 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
20880 NGINX configuration.
20884 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
20885 Specifies a command which will be invoked to format the content of about
20886 pages (both top-level and for each repository).
20888 Defaults to @samp{""}.
20892 @deftypevr {@code{cgit-configuration} parameter} string agefile
20893 Specifies a path, relative to each repository path, which can be used to
20894 specify the date and time of the youngest commit in the repository.
20896 Defaults to @samp{""}.
20900 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
20901 Specifies a command that will be invoked for authenticating repository
20904 Defaults to @samp{""}.
20908 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
20909 Flag which, when set to @samp{age}, enables date ordering in the branch
20910 ref list, and when set @samp{name} enables ordering by branch name.
20912 Defaults to @samp{"name"}.
20916 @deftypevr {@code{cgit-configuration} parameter} string cache-root
20917 Path used to store the cgit cache entries.
20919 Defaults to @samp{"/var/cache/cgit"}.
20923 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
20924 Number which specifies the time-to-live, in minutes, for the cached
20925 version of repository pages accessed with a fixed SHA1.
20927 Defaults to @samp{-1}.
20931 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
20932 Number which specifies the time-to-live, in minutes, for the cached
20933 version of repository pages accessed without a fixed SHA1.
20935 Defaults to @samp{5}.
20939 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
20940 Number which specifies the time-to-live, in minutes, for the cached
20941 version of the repository summary page.
20943 Defaults to @samp{5}.
20947 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
20948 Number which specifies the time-to-live, in minutes, for the cached
20949 version of the repository index page.
20951 Defaults to @samp{5}.
20955 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
20956 Number which specifies the time-to-live, in minutes, for the result of
20957 scanning a path for Git repositories.
20959 Defaults to @samp{15}.
20963 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
20964 Number which specifies the time-to-live, in minutes, for the cached
20965 version of the repository about page.
20967 Defaults to @samp{15}.
20971 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
20972 Number which specifies the time-to-live, in minutes, for the cached
20973 version of snapshots.
20975 Defaults to @samp{5}.
20979 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
20980 The maximum number of entries in the cgit cache. When set to @samp{0},
20981 caching is disabled.
20983 Defaults to @samp{0}.
20987 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
20988 Sort items in the repo list case sensitively.
20990 Defaults to @samp{#t}.
20994 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
20995 List of common prefixes which, when combined with a repository URL,
20996 generates valid clone URLs for the repository.
20998 Defaults to @samp{()}.
21002 @deftypevr {@code{cgit-configuration} parameter} list clone-url
21003 List of @code{clone-url} templates.
21005 Defaults to @samp{()}.
21009 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
21010 Command which will be invoked to format commit messages.
21012 Defaults to @samp{""}.
21016 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
21017 Flag which, when set to @samp{date}, enables strict date ordering in the
21018 commit log, and when set to @samp{topo} enables strict topological
21021 Defaults to @samp{"git log"}.
21025 @deftypevr {@code{cgit-configuration} parameter} file-object css
21026 URL which specifies the css document to include in all cgit pages.
21028 Defaults to @samp{"/share/cgit/cgit.css"}.
21032 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
21033 Specifies a command which will be invoked to format names and email
21034 address of committers, authors, and taggers, as represented in various
21035 places throughout the cgit interface.
21037 Defaults to @samp{""}.
21041 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
21042 Flag which, when set to @samp{#t}, will make cgit generate a HTML
21043 fragment suitable for embedding in other HTML pages.
21045 Defaults to @samp{#f}.
21049 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
21050 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
21051 commit history graph to the left of the commit messages in the
21052 repository log page.
21054 Defaults to @samp{#f}.
21058 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
21059 Flag which, when set to @samp{#t}, allows all filter settings to be
21060 overridden in repository-specific cgitrc files.
21062 Defaults to @samp{#f}.
21066 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
21067 Flag which, when set to @samp{#t}, allows users to follow a file in the
21070 Defaults to @samp{#f}.
21074 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
21075 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
21078 Defaults to @samp{#t}.
21082 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
21083 Flag which, when set to @samp{#t}, will make cgit generate extra links
21084 "summary", "commit", "tree" for each repo in the repository index.
21086 Defaults to @samp{#f}.
21090 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
21091 Flag which, when set to @samp{#t}, will make cgit display the owner of
21092 each repo in the repository index.
21094 Defaults to @samp{#t}.
21098 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
21099 Flag which, when set to @samp{#t}, will make cgit print the number of
21100 modified files for each commit on the repository log page.
21102 Defaults to @samp{#f}.
21106 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
21107 Flag which, when set to @samp{#t}, will make cgit print the number of
21108 added and removed lines for each commit on the repository log page.
21110 Defaults to @samp{#f}.
21114 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
21115 Flag which, when set to @code{#t}, will make cgit display remote
21116 branches in the summary and refs views.
21118 Defaults to @samp{#f}.
21122 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
21123 Flag which, when set to @code{1}, will make cgit use the subject of the
21124 parent commit as link text when generating links to parent commits in
21127 Defaults to @samp{#f}.
21131 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
21132 Flag which, when set to @samp{#t}, will make cgit use the subject of the
21133 parent commit as link text when generating links to parent commits in
21136 Defaults to @samp{#f}.
21140 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
21141 Flag which, when set to @samp{#t}, will make cgit generate linenumber
21142 links for plaintext blobs printed in the tree view.
21144 Defaults to @samp{#t}.
21148 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
21149 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
21150 set any repo specific settings.
21152 Defaults to @samp{#f}.
21156 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
21157 URL used as link to a shortcut icon for cgit.
21159 Defaults to @samp{"/favicon.ico"}.
21163 @deftypevr {@code{cgit-configuration} parameter} string footer
21164 The content of the file specified with this option will be included
21165 verbatim at the bottom of all pages (i.e.@: it replaces the standard
21166 "generated by..."@: message).
21168 Defaults to @samp{""}.
21172 @deftypevr {@code{cgit-configuration} parameter} string head-include
21173 The content of the file specified with this option will be included
21174 verbatim in the HTML HEAD section on all pages.
21176 Defaults to @samp{""}.
21180 @deftypevr {@code{cgit-configuration} parameter} string header
21181 The content of the file specified with this option will be included
21182 verbatim at the top of all pages.
21184 Defaults to @samp{""}.
21188 @deftypevr {@code{cgit-configuration} parameter} file-object include
21189 Name of a configfile to include before the rest of the current config-
21192 Defaults to @samp{""}.
21196 @deftypevr {@code{cgit-configuration} parameter} string index-header
21197 The content of the file specified with this option will be included
21198 verbatim above the repository index.
21200 Defaults to @samp{""}.
21204 @deftypevr {@code{cgit-configuration} parameter} string index-info
21205 The content of the file specified with this option will be included
21206 verbatim below the heading on the repository index page.
21208 Defaults to @samp{""}.
21212 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
21213 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
21214 in the servers timezone.
21216 Defaults to @samp{#f}.
21220 @deftypevr {@code{cgit-configuration} parameter} file-object logo
21221 URL which specifies the source of an image which will be used as a logo
21224 Defaults to @samp{"/share/cgit/cgit.png"}.
21228 @deftypevr {@code{cgit-configuration} parameter} string logo-link
21229 URL loaded when clicking on the cgit logo image.
21231 Defaults to @samp{""}.
21235 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
21236 Command which will be invoked to format the Owner column of the main
21239 Defaults to @samp{""}.
21243 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
21244 Number of items to display in atom feeds view.
21246 Defaults to @samp{10}.
21250 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
21251 Number of entries to list per page in "log" view.
21253 Defaults to @samp{50}.
21257 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
21258 Number of commit message characters to display in "log" view.
21260 Defaults to @samp{80}.
21264 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
21265 Specifies the number of entries to list per page on the repository index
21268 Defaults to @samp{50}.
21272 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
21273 Specifies the maximum number of repo description characters to display
21274 on the repository index page.
21276 Defaults to @samp{80}.
21280 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
21281 Specifies the maximum size of a blob to display HTML for in KBytes.
21283 Defaults to @samp{0}.
21287 @deftypevr {@code{cgit-configuration} parameter} string max-stats
21288 Maximum statistics period. Valid values are @samp{week},@samp{month},
21289 @samp{quarter} and @samp{year}.
21291 Defaults to @samp{""}.
21295 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
21296 Mimetype for the specified filename extension.
21298 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
21299 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
21300 "image/png") (svg "image/svg+xml"))}.
21304 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
21305 Specifies the file to use for automatic mimetype lookup.
21307 Defaults to @samp{""}.
21311 @deftypevr {@code{cgit-configuration} parameter} string module-link
21312 Text which will be used as the formatstring for a hyperlink when a
21313 submodule is printed in a directory listing.
21315 Defaults to @samp{""}.
21319 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
21320 If set to the value @samp{#t} caching will be disabled.
21322 Defaults to @samp{#f}.
21326 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
21327 If set to @samp{#t} showing full author email addresses will be
21330 Defaults to @samp{#f}.
21334 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
21335 Flag which, when set to @samp{#t}, will make cgit omit the standard
21336 header on all pages.
21338 Defaults to @samp{#f}.
21342 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
21343 A list of subdirectories inside of @code{repository-directory}, relative
21344 to it, that should loaded as Git repositories. An empty list means that
21345 all subdirectories will be loaded.
21347 Defaults to @samp{()}.
21351 @deftypevr {@code{cgit-configuration} parameter} file-object readme
21352 Text which will be used as default value for @code{cgit-repo-readme}.
21354 Defaults to @samp{""}.
21358 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
21359 If set to @code{#t} and @code{repository-directory} is enabled, if any
21360 repositories are found with a suffix of @code{.git}, this suffix will be
21361 removed for the URL and name.
21363 Defaults to @samp{#f}.
21367 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
21368 Maximum number of files to consider when detecting renames.
21370 Defaults to @samp{-1}.
21374 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
21375 The way in which repositories in each section are sorted.
21377 Defaults to @samp{""}.
21381 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
21382 Text used as content for the @code{robots} meta-tag.
21384 Defaults to @samp{("noindex" "nofollow")}.
21388 @deftypevr {@code{cgit-configuration} parameter} string root-desc
21389 Text printed below the heading on the repository index page.
21391 Defaults to @samp{"a fast webinterface for the git dscm"}.
21395 @deftypevr {@code{cgit-configuration} parameter} string root-readme
21396 The content of the file specified with this option will be included
21397 verbatim below thef "about" link on the repository index page.
21399 Defaults to @samp{""}.
21403 @deftypevr {@code{cgit-configuration} parameter} string root-title
21404 Text printed as heading on the repository index page.
21406 Defaults to @samp{""}.
21410 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
21411 If set to @samp{#t} and repository-directory is enabled,
21412 repository-directory will recurse into directories whose name starts
21413 with a period. Otherwise, repository-directory will stay away from such
21414 directories, considered as "hidden". Note that this does not apply to
21415 the ".git" directory in non-bare repos.
21417 Defaults to @samp{#f}.
21421 @deftypevr {@code{cgit-configuration} parameter} list snapshots
21422 Text which specifies the default set of snapshot formats that cgit
21423 generates links for.
21425 Defaults to @samp{()}.
21429 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
21430 Name of the directory to scan for repositories (represents
21433 Defaults to @samp{"/srv/git"}.
21437 @deftypevr {@code{cgit-configuration} parameter} string section
21438 The name of the current repository section - all repositories defined
21439 after this option will inherit the current section name.
21441 Defaults to @samp{""}.
21445 @deftypevr {@code{cgit-configuration} parameter} string section-sort
21446 Flag which, when set to @samp{1}, will sort the sections on the
21447 repository listing by name.
21449 Defaults to @samp{""}.
21453 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
21454 A number which, if defined prior to repository-directory, specifies how
21455 many path elements from each repo path to use as a default section name.
21457 Defaults to @samp{0}.
21461 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
21462 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
21465 Defaults to @samp{#f}.
21469 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
21470 Specifies a command which will be invoked to format plaintext blobs in
21473 Defaults to @samp{""}.
21477 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
21478 Specifies the number of branches to display in the repository "summary"
21481 Defaults to @samp{10}.
21485 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
21486 Specifies the number of log entries to display in the repository
21489 Defaults to @samp{10}.
21493 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
21494 Specifies the number of tags to display in the repository "summary"
21497 Defaults to @samp{10}.
21501 @deftypevr {@code{cgit-configuration} parameter} string strict-export
21502 Filename which, if specified, needs to be present within the repository
21503 for cgit to allow access to that repository.
21505 Defaults to @samp{""}.
21509 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
21510 URL which, if specified, will be used as root for all cgit links.
21512 Defaults to @samp{"/"}.
21516 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
21517 A list of @dfn{cgit-repo} records to use with config.
21519 Defaults to @samp{()}.
21521 Available @code{repository-cgit-configuration} fields are:
21523 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
21524 A mask of snapshot formats for this repo that cgit generates links for,
21525 restricted by the global @code{snapshots} setting.
21527 Defaults to @samp{()}.
21531 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
21532 Override the default @code{source-filter}.
21534 Defaults to @samp{""}.
21538 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
21539 The relative URL used to access the repository.
21541 Defaults to @samp{""}.
21545 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
21546 Override the default @code{about-filter}.
21548 Defaults to @samp{""}.
21552 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
21553 Flag which, when set to @samp{age}, enables date ordering in the branch
21554 ref list, and when set to @samp{name} enables ordering by branch name.
21556 Defaults to @samp{""}.
21560 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
21561 A list of URLs which can be used to clone repo.
21563 Defaults to @samp{()}.
21567 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
21568 Override the default @code{commit-filter}.
21570 Defaults to @samp{""}.
21574 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
21575 Flag which, when set to @samp{date}, enables strict date ordering in the
21576 commit log, and when set to @samp{topo} enables strict topological
21579 Defaults to @samp{""}.
21583 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
21584 The name of the default branch for this repository. If no such branch
21585 exists in the repository, the first branch name (when sorted) is used as
21586 default instead. By default branch pointed to by HEAD, or "master" if
21587 there is no suitable HEAD.
21589 Defaults to @samp{""}.
21593 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
21594 The value to show as repository description.
21596 Defaults to @samp{""}.
21600 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
21601 The value to show as repository homepage.
21603 Defaults to @samp{""}.
21607 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
21608 Override the default @code{email-filter}.
21610 Defaults to @samp{""}.
21614 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
21615 A flag which can be used to disable the global setting
21616 @code{enable-commit-graph?}.
21618 Defaults to @samp{disabled}.
21622 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
21623 A flag which can be used to disable the global setting
21624 @code{enable-log-filecount?}.
21626 Defaults to @samp{disabled}.
21630 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
21631 A flag which can be used to disable the global setting
21632 @code{enable-log-linecount?}.
21634 Defaults to @samp{disabled}.
21638 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
21639 Flag which, when set to @code{#t}, will make cgit display remote
21640 branches in the summary and refs views.
21642 Defaults to @samp{disabled}.
21646 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
21647 A flag which can be used to override the global setting
21648 @code{enable-subject-links?}.
21650 Defaults to @samp{disabled}.
21654 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
21655 A flag which can be used to override the global setting
21656 @code{enable-html-serving?}.
21658 Defaults to @samp{disabled}.
21662 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
21663 Flag which, when set to @code{#t}, hides the repository from the
21666 Defaults to @samp{#f}.
21670 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
21671 Flag which, when set to @samp{#t}, ignores the repository.
21673 Defaults to @samp{#f}.
21677 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
21678 URL which specifies the source of an image which will be used as a logo
21679 on this repo’s pages.
21681 Defaults to @samp{""}.
21685 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
21686 URL loaded when clicking on the cgit logo image.
21688 Defaults to @samp{""}.
21692 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
21693 Override the default @code{owner-filter}.
21695 Defaults to @samp{""}.
21699 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
21700 Text which will be used as the formatstring for a hyperlink when a
21701 submodule is printed in a directory listing. The arguments for the
21702 formatstring are the path and SHA1 of the submodule commit.
21704 Defaults to @samp{""}.
21708 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
21709 Text which will be used as the formatstring for a hyperlink when a
21710 submodule with the specified subdirectory path is printed in a directory
21713 Defaults to @samp{()}.
21717 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
21718 Override the default maximum statistics period.
21720 Defaults to @samp{""}.
21724 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
21725 The value to show as repository name.
21727 Defaults to @samp{""}.
21731 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
21732 A value used to identify the owner of the repository.
21734 Defaults to @samp{""}.
21738 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
21739 An absolute path to the repository directory.
21741 Defaults to @samp{""}.
21745 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
21746 A path (relative to repo) which specifies a file to include verbatim as
21747 the "About" page for this repo.
21749 Defaults to @samp{""}.
21753 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
21754 The name of the current repository section - all repositories defined
21755 after this option will inherit the current section name.
21757 Defaults to @samp{""}.
21761 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
21762 Extra options will be appended to cgitrc file.
21764 Defaults to @samp{()}.
21770 @deftypevr {@code{cgit-configuration} parameter} list extra-options
21771 Extra options will be appended to cgitrc file.
21773 Defaults to @samp{()}.
21778 @c %end of fragment
21780 However, it could be that you just want to get a @code{cgitrc} up and
21781 running. In that case, you can pass an @code{opaque-cgit-configuration}
21782 as a record to @code{cgit-service-type}. As its name indicates, an
21783 opaque configuration does not have easy reflective capabilities.
21785 Available @code{opaque-cgit-configuration} fields are:
21787 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
21791 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
21792 The contents of the @code{cgitrc}, as a string.
21795 For example, if your @code{cgitrc} is just the empty string, you
21796 could instantiate a cgit service like this:
21799 (service cgit-service-type
21800 (opaque-cgit-configuration
21804 @subsubheading Gitolite Service
21806 @cindex Gitolite service
21807 @cindex Git, hosting
21808 @uref{http://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
21809 repositories on a central server.
21811 Gitolite can handle multiple repositories and users, and supports flexible
21812 configuration of the permissions for the users on the repositories.
21814 The following example will configure Gitolite using the default @code{git}
21815 user, and the provided SSH public key.
21818 (service gitolite-service-type
21819 (gitolite-configuration
21820 (admin-pubkey (plain-file
21822 "ssh-rsa AAAA... guix@@example.com"))))
21825 Gitolite is configured through a special admin repository which you can clone,
21826 for example, if you setup Gitolite on @code{example.com}, you would run the
21827 following command to clone the admin repository.
21830 git clone git@@example.com:gitolite-admin
21833 When the Gitolite service is activated, the provided @code{admin-pubkey} will
21834 be inserted in to the @file{keydir} directory in the gitolite-admin
21835 repository. If this results in a change in the repository, it will be
21836 committed using the message ``gitolite setup by GNU Guix''.
21838 @deftp {Data Type} gitolite-configuration
21839 Data type representing the configuration for @code{gitolite-service-type}.
21842 @item @code{package} (default: @var{gitolite})
21843 Gitolite package to use.
21845 @item @code{user} (default: @var{git})
21846 User to use for Gitolite. This will be user that you use when accessing
21849 @item @code{group} (default: @var{git})
21850 Group to use for Gitolite.
21852 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
21853 Directory in which to store the Gitolite configuration and repositories.
21855 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
21856 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
21857 representing the configuration for Gitolite.
21859 @item @code{admin-pubkey} (default: @var{#f})
21860 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
21861 setup Gitolite. This will be inserted in to the @file{keydir} directory
21862 within the gitolite-admin repository.
21864 To specify the SSH key as a string, use the @code{plain-file} function.
21867 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
21873 @deftp {Data Type} gitolite-rc-file
21874 Data type representing the Gitolite RC file.
21877 @item @code{umask} (default: @code{#o0077})
21878 This controls the permissions Gitolite sets on the repositories and their
21881 A value like @code{#o0027} will give read access to the group used by Gitolite
21882 (by default: @code{git}). This is necessary when using Gitolite with software
21883 like cgit or gitweb.
21885 @item @code{git-config-keys} (default: @code{""})
21886 Gitolite allows you to set git config values using the "config" keyword. This
21887 setting allows control over the config keys to accept.
21889 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
21890 Set the role names allowed to be used by users running the perms command.
21892 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
21893 This setting controls the commands and features to enable within Gitolite.
21899 @node Game Services
21900 @subsection Game Services
21902 @subsubheading The Battle for Wesnoth Service
21904 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
21905 based tactical strategy game, with several single player campaigns, and
21906 multiplayer games (both networked and local).
21908 @defvar {Scheme Variable} wesnothd-service-type
21909 Service type for the wesnothd service. Its value must be a
21910 @code{wesnothd-configuration} object. To run wesnothd in the default
21911 configuration, instantiate it as:
21914 (service wesnothd-service-type)
21918 @deftp {Data Type} wesnothd-configuration
21919 Data type representing the configuration of @command{wesnothd}.
21922 @item @code{package} (default: @code{wesnoth-server})
21923 The wesnoth server package to use.
21925 @item @code{port} (default: @code{15000})
21926 The port to bind the server to.
21930 @node Miscellaneous Services
21931 @subsection Miscellaneous Services
21933 @cindex fingerprint
21934 @subsubheading Fingerprint Service
21936 The @code{(gnu services fingerprint)} module provides a DBus service to
21937 read and identify fingerprints via a fingerprint sensor.
21939 @defvr {Scheme Variable} fprintd-service-type
21940 The service type for @command{fprintd}, which provides the fingerprint
21941 reading capability.
21944 (service fprintd-service-type)
21949 @subsubheading System Control Service
21951 The @code{(gnu services sysctl)} provides a service to configure kernel
21952 parameters at boot.
21954 @defvr {Scheme Variable} sysctl-service-type
21955 The service type for @command{sysctl}, which modifies kernel parameters
21956 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
21960 (service sysctl-service-type
21961 (sysctl-configuration
21962 (settings '(("net.ipv4.ip_forward" . "1")))))
21966 @deftp {Data Type} sysctl-configuration
21967 The data type representing the configuration of @command{sysctl}.
21970 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
21971 The @command{sysctl} executable to use.
21973 @item @code{settings} (default: @code{'()})
21974 An association list specifies kernel parameters and their values.
21979 @subsubheading PC/SC Smart Card Daemon Service
21981 The @code{(gnu services security-token)} module provides the following service
21982 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
21983 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
21984 manager that coordinates communications with smart card readers, smart cards
21985 and cryptographic tokens that are connected to the system.
21987 @defvr {Scheme Variable} pcscd-service-type
21988 Service type for the @command{pcscd} service. Its value must be a
21989 @code{pcscd-configuration} object. To run pcscd in the default
21990 configuration, instantiate it as:
21993 (service pcscd-service-type)
21997 @deftp {Data Type} pcscd-configuration
21998 The data type representing the configuration of @command{pcscd}.
22001 @item @code{pcsc-lite} (default: @code{pcsc-lite})
22002 The pcsc-lite package that provides pcscd.
22003 @item @code{usb-drivers} (default: @code{(list ccid)})
22004 List of packages that provide USB drivers to pcscd. Drivers are expected to be
22005 under @file{pcsc/drivers} in the store directory of the package.
22010 @subsubheading Lirc Service
22012 The @code{(gnu services lirc)} module provides the following service.
22014 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
22015 [#:device #f] [#:driver #f] [#:config-file #f] @
22016 [#:extra-options '()]
22017 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
22018 decodes infrared signals from remote controls.
22020 Optionally, @var{device}, @var{driver} and @var{config-file}
22021 (configuration file name) may be specified. See @command{lircd} manual
22024 Finally, @var{extra-options} is a list of additional command-line options
22025 passed to @command{lircd}.
22029 @subsubheading Spice Service
22031 The @code{(gnu services spice)} module provides the following service.
22033 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
22034 Returns a service that runs @url{http://www.spice-space.org,VDAGENT}, a daemon
22035 that enables sharing the clipboard with a vm and setting the guest display
22036 resolution when the graphical console window resizes.
22039 @subsection Dictionary Services
22041 The @code{(gnu services dict)} module provides the following service:
22043 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
22044 Return a service that runs the @command{dicod} daemon, an implementation
22045 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
22047 The optional @var{config} argument specifies the configuration for
22048 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
22049 default it serves the GNU Collaborative International Dictonary of English.
22051 You can add @command{open localhost} to your @file{~/.dico} file to make
22052 @code{localhost} the default server for @command{dico} client
22053 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
22056 @deftp {Data Type} dicod-configuration
22057 Data type representing the configuration of dicod.
22060 @item @code{dico} (default: @var{dico})
22061 Package object of the GNU Dico dictionary server.
22063 @item @code{interfaces} (default: @var{'("localhost")})
22064 This is the list of IP addresses and ports and possibly socket file
22065 names to listen to (@pxref{Server Settings, @code{listen} directive,,
22066 dico, GNU Dico Manual}).
22068 @item @code{handlers} (default: @var{'()})
22069 List of @code{<dicod-handler>} objects denoting handlers (module instances).
22071 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
22072 List of @code{<dicod-database>} objects denoting dictionaries to be served.
22076 @deftp {Data Type} dicod-handler
22077 Data type representing a dictionary handler (module instance).
22081 Name of the handler (module instance).
22083 @item @code{module} (default: @var{#f})
22084 Name of the dicod module of the handler (instance). If it is @code{#f},
22085 the module has the same name as the handler.
22086 (@pxref{Modules,,, dico, GNU Dico Manual}).
22088 @item @code{options}
22089 List of strings or gexps representing the arguments for the module handler
22093 @deftp {Data Type} dicod-database
22094 Data type representing a dictionary database.
22098 Name of the database, will be used in DICT commands.
22100 @item @code{handler}
22101 Name of the dicod handler (module instance) used by this database
22102 (@pxref{Handlers,,, dico, GNU Dico Manual}).
22104 @item @code{complex?} (default: @var{#f})
22105 Whether the database configuration complex. The complex configuration
22106 will need a corresponding @code{<dicod-handler>} object, otherwise not.
22108 @item @code{options}
22109 List of strings or gexps representing the arguments for the database
22110 (@pxref{Databases,,, dico, GNU Dico Manual}).
22114 @defvr {Scheme Variable} %dicod-database:gcide
22115 A @code{<dicod-database>} object serving the GNU Collaborative International
22116 Dictionary of English using the @code{gcide} package.
22119 The following is an example @code{dicod-service} configuration.
22122 (dicod-service #:config
22123 (dicod-configuration
22124 (handlers (list (dicod-handler
22128 (list #~(string-append "dbdir=" #$wordnet))))))
22129 (databases (list (dicod-database
22132 (handler "wordnet")
22133 (options '("database=wn")))
22134 %dicod-database:gcide))))
22138 @subsubheading Docker Service
22140 The @code{(gnu services docker)} module provides the following service.
22142 @defvr {Scheme Variable} docker-service-type
22144 This is the type of the service that runs @url{http://www.docker.com,Docker},
22145 a daemon that can execute application bundles (sometimes referred to as
22146 ``containers'') in isolated environments.
22150 @deftp {Data Type} docker-configuration
22151 This is the data type representing the configuration of Docker and Containerd.
22155 @item @code{package} (default: @code{docker})
22156 The Docker package to use.
22158 @item @code{containerd} (default: @var{containerd})
22159 The Containerd package to use.
22164 @node Setuid Programs
22165 @section Setuid Programs
22167 @cindex setuid programs
22168 Some programs need to run with ``root'' privileges, even when they are
22169 launched by unprivileged users. A notorious example is the
22170 @command{passwd} program, which users can run to change their
22171 password, and which needs to access the @file{/etc/passwd} and
22172 @file{/etc/shadow} files---something normally restricted to root, for
22173 obvious security reasons. To address that, these executables are
22174 @dfn{setuid-root}, meaning that they always run with root privileges
22175 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
22176 for more info about the setuid mechanism.)
22178 The store itself @emph{cannot} contain setuid programs: that would be a
22179 security issue since any user on the system can write derivations that
22180 populate the store (@pxref{The Store}). Thus, a different mechanism is
22181 used: instead of changing the setuid bit directly on files that are in
22182 the store, we let the system administrator @emph{declare} which programs
22183 should be setuid root.
22185 The @code{setuid-programs} field of an @code{operating-system}
22186 declaration contains a list of G-expressions denoting the names of
22187 programs to be setuid-root (@pxref{Using the Configuration System}).
22188 For instance, the @command{passwd} program, which is part of the Shadow
22189 package, can be designated by this G-expression (@pxref{G-Expressions}):
22192 #~(string-append #$shadow "/bin/passwd")
22195 A default set of setuid programs is defined by the
22196 @code{%setuid-programs} variable of the @code{(gnu system)} module.
22198 @defvr {Scheme Variable} %setuid-programs
22199 A list of G-expressions denoting common programs that are setuid-root.
22201 The list includes commands such as @command{passwd}, @command{ping},
22202 @command{su}, and @command{sudo}.
22205 Under the hood, the actual setuid programs are created in the
22206 @file{/run/setuid-programs} directory at system activation time. The
22207 files in this directory refer to the ``real'' binaries, which are in the
22210 @node X.509 Certificates
22211 @section X.509 Certificates
22213 @cindex HTTPS, certificates
22214 @cindex X.509 certificates
22216 Web servers available over HTTPS (that is, HTTP over the transport-layer
22217 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
22218 that the client can then use to @emph{authenticate} the server. To do
22219 that, clients verify that the server's certificate is signed by a
22220 so-called @dfn{certificate authority} (CA). But to verify the CA's
22221 signature, clients must have first acquired the CA's certificate.
22223 Web browsers such as GNU@tie{}IceCat include their own set of CA
22224 certificates, such that they are able to verify CA signatures
22227 However, most other programs that can talk HTTPS---@command{wget},
22228 @command{git}, @command{w3m}, etc.---need to be told where CA
22229 certificates can be found.
22231 @cindex @code{nss-certs}
22232 In GuixSD, this is done by adding a package that provides certificates
22233 to the @code{packages} field of the @code{operating-system} declaration
22234 (@pxref{operating-system Reference}). GuixSD includes one such package,
22235 @code{nss-certs}, which is a set of CA certificates provided as part of
22236 Mozilla's Network Security Services.
22238 Note that it is @emph{not} part of @var{%base-packages}, so you need to
22239 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
22240 most applications and libraries look for certificates by default, points
22241 to the certificates installed globally.
22243 Unprivileged users, including users of Guix on a foreign distro,
22244 can also install their own certificate package in
22245 their profile. A number of environment variables need to be defined so
22246 that applications and libraries know where to find them. Namely, the
22247 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
22248 variables. Some applications add their own environment variables; for
22249 instance, the Git version control system honors the certificate bundle
22250 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
22251 would typically run something like:
22254 $ guix package -i nss-certs
22255 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
22256 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
22257 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
22260 As another example, R requires the @code{CURL_CA_BUNDLE} environment
22261 variable to point to a certificate bundle, so you would have to run
22262 something like this:
22265 $ guix package -i nss-certs
22266 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
22269 For other applications you may want to look up the required environment
22270 variable in the relevant documentation.
22273 @node Name Service Switch
22274 @section Name Service Switch
22276 @cindex name service switch
22278 The @code{(gnu system nss)} module provides bindings to the
22279 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
22280 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
22281 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
22282 extended with new ``name'' lookup methods for system databases, which
22283 includes host names, service names, user accounts, and more (@pxref{Name
22284 Service Switch, System Databases and Name Service Switch,, libc, The GNU
22285 C Library Reference Manual}).
22287 The NSS configuration specifies, for each system database, which lookup
22288 method is to be used, and how the various methods are chained
22289 together---for instance, under which circumstances NSS should try the
22290 next method in the list. The NSS configuration is given in the
22291 @code{name-service-switch} field of @code{operating-system} declarations
22292 (@pxref{operating-system Reference, @code{name-service-switch}}).
22295 @cindex .local, host name lookup
22296 As an example, the declaration below configures the NSS to use the
22297 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
22298 back-end}, which supports host name lookups over multicast DNS (mDNS)
22299 for host names ending in @code{.local}:
22302 (name-service-switch
22303 (hosts (list %files ;first, check /etc/hosts
22305 ;; If the above did not succeed, try
22306 ;; with 'mdns_minimal'.
22308 (name "mdns_minimal")
22310 ;; 'mdns_minimal' is authoritative for
22311 ;; '.local'. When it returns "not found",
22312 ;; no need to try the next methods.
22313 (reaction (lookup-specification
22314 (not-found => return))))
22316 ;; Then fall back to DNS.
22320 ;; Finally, try with the "full" 'mdns'.
22325 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
22326 contains this configuration, so you will not have to type it if all you
22327 want is to have @code{.local} host lookup working.
22329 Note that, in this case, in addition to setting the
22330 @code{name-service-switch} of the @code{operating-system} declaration,
22331 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
22332 @code{avahi-service-type}}), or @var{%desktop-services}, which includes it
22333 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
22334 to the name service cache daemon (@pxref{Base Services,
22335 @code{nscd-service}}).
22337 For convenience, the following variables provide typical NSS
22340 @defvr {Scheme Variable} %default-nss
22341 This is the default name service switch configuration, a
22342 @code{name-service-switch} object.
22345 @defvr {Scheme Variable} %mdns-host-lookup-nss
22346 This is the name service switch configuration with support for host name
22347 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
22350 The reference for name service switch configuration is given below. It
22351 is a direct mapping of the configuration file format of the C library , so
22352 please refer to the C library manual for more information (@pxref{NSS
22353 Configuration File,,, libc, The GNU C Library Reference Manual}).
22354 Compared to the configuration file format of libc NSS, it has the advantage
22355 not only of adding this warm parenthetic feel that we like, but also
22356 static checks: you will know about syntax errors and typos as soon as you
22357 run @command{guix system}.
22359 @deftp {Data Type} name-service-switch
22361 This is the data type representation the configuration of libc's name
22362 service switch (NSS). Each field below represents one of the supported
22379 The system databases handled by the NSS. Each of these fields must be a
22380 list of @code{<name-service>} objects (see below).
22384 @deftp {Data Type} name-service
22386 This is the data type representing an actual name service and the
22387 associated lookup action.
22391 A string denoting the name service (@pxref{Services in the NSS
22392 configuration,,, libc, The GNU C Library Reference Manual}).
22394 Note that name services listed here must be visible to nscd. This is
22395 achieved by passing the @code{#:name-services} argument to
22396 @code{nscd-service} the list of packages providing the needed name
22397 services (@pxref{Base Services, @code{nscd-service}}).
22400 An action specified using the @code{lookup-specification} macro
22401 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
22402 Reference Manual}). For example:
22405 (lookup-specification (unavailable => continue)
22406 (success => return))
22411 @node Initial RAM Disk
22412 @section Initial RAM Disk
22415 @cindex initial RAM disk
22416 For bootstrapping purposes, the Linux-Libre kernel is passed an
22417 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
22418 root file system as well as an initialization script. The latter is
22419 responsible for mounting the real root file system, and for loading any
22420 kernel modules that may be needed to achieve that.
22422 The @code{initrd-modules} field of an @code{operating-system}
22423 declaration allows you to specify Linux-libre kernel modules that must
22424 be available in the initrd. In particular, this is where you would list
22425 modules needed to actually drive the hard disk where your root partition
22426 is---although the default value of @code{initrd-modules} should cover
22427 most use cases. For example, assuming you need the @code{megaraid_sas}
22428 module in addition to the default modules to be able to access your root
22429 file system, you would write:
22434 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
22437 @defvr {Scheme Variable} %base-initrd-modules
22438 This is the list of kernel modules included in the initrd by default.
22441 Furthermore, if you need lower-level customization, the @code{initrd}
22442 field of an @code{operating-system} declaration allows
22443 you to specify which initrd you would like to use. The @code{(gnu
22444 system linux-initrd)} module provides three ways to build an initrd: the
22445 high-level @code{base-initrd} procedure and the low-level
22446 @code{raw-initrd} and @code{expression->initrd} procedures.
22448 The @code{base-initrd} procedure is intended to cover most common uses.
22449 For example, if you want to add a bunch of kernel modules to be loaded
22450 at boot time, you can define the @code{initrd} field of the operating
22451 system declaration like this:
22454 (initrd (lambda (file-systems . rest)
22455 ;; Create a standard initrd but set up networking
22456 ;; with the parameters QEMU expects by default.
22457 (apply base-initrd file-systems
22458 #:qemu-networking? #t
22462 The @code{base-initrd} procedure also handles common use cases that
22463 involves using the system as a QEMU guest, or as a ``live'' system with
22464 volatile root file system.
22466 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
22467 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
22468 such as trying to guess which kernel modules and packages should be included
22469 to the initrd. An example use of @code{raw-initrd} is when a user has
22470 a custom Linux kernel configuration and default kernel modules included by
22471 @code{base-initrd} are not available.
22473 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
22474 honors several options passed on the Linux kernel command line
22475 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
22476 @code{-append} option of QEMU), notably:
22479 @item --load=@var{boot}
22480 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
22481 program, once it has mounted the root file system.
22483 GuixSD uses this option to yield control to a boot program that runs the
22484 service activation programs and then spawns the GNU@tie{}Shepherd, the
22485 initialization system.
22487 @item --root=@var{root}
22488 Mount @var{root} as the root file system. @var{root} can be a
22489 device name like @code{/dev/sda1}, a file system label, or a file system
22492 @item --system=@var{system}
22493 Have @file{/run/booted-system} and @file{/run/current-system} point to
22496 @item modprobe.blacklist=@var{modules}@dots{}
22497 @cindex module, black-listing
22498 @cindex black list, of kernel modules
22499 Instruct the initial RAM disk as well as the @command{modprobe} command
22500 (from the kmod package) to refuse to load @var{modules}. @var{modules}
22501 must be a comma-separated list of module names---e.g.,
22502 @code{usbkbd,9pnet}.
22505 Start a read-eval-print loop (REPL) from the initial RAM disk before it
22506 tries to load kernel modules and to mount the root file system. Our
22507 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
22508 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
22509 Manual}, for more information on Guile's REPL.
22513 Now that you know all the features that initial RAM disks produced by
22514 @code{base-initrd} and @code{raw-initrd} provide,
22515 here is how to use it and customize it further.
22518 @cindex initial RAM disk
22519 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
22520 [#:linux-modules '()] [#:mapped-devices '()] @
22521 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
22522 Return a derivation that builds a raw initrd. @var{file-systems} is
22523 a list of file systems to be mounted by the initrd, possibly in addition to
22524 the root file system specified on the kernel command line via @code{--root}.
22525 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
22526 @var{mapped-devices} is a list of device mappings to realize before
22527 @var{file-systems} are mounted (@pxref{Mapped Devices}).
22528 @var{helper-packages} is a list of packages to be copied in the initrd. It may
22529 include @code{e2fsck/static} or other packages needed by the initrd to check
22530 the root file system.
22532 When @var{qemu-networking?} is true, set up networking with the standard QEMU
22533 parameters. When @var{virtio?} is true, load additional modules so that the
22534 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
22536 When @var{volatile-root?} is true, the root file system is writable but any changes
22540 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
22541 [#:mapped-devices '()] [#:qemu-networking? #f] [#:volatile-root? #f]@
22542 [#:linux-modules '()]
22543 Return as a file-like object a generic initrd, with kernel
22544 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
22545 mounted by the initrd, possibly in addition to the root file system specified
22546 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
22547 mappings to realize before @var{file-systems} are mounted.
22549 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
22551 The initrd is automatically populated with all the kernel modules necessary
22552 for @var{file-systems} and for the given options. Additional kernel
22553 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
22554 loaded at boot time in the order in which they appear.
22557 Needless to say, the initrds we produce and use embed a
22558 statically-linked Guile, and the initialization program is a Guile
22559 program. That gives a lot of flexibility. The
22560 @code{expression->initrd} procedure builds such an initrd, given the
22561 program to run in that initrd.
22563 @deffn {Scheme Procedure} expression->initrd @var{exp} @
22564 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
22565 Return as a file-like object a Linux initrd (a gzipped cpio archive)
22566 containing @var{guile} and that evaluates @var{exp}, a G-expression,
22567 upon booting. All the derivations referenced by @var{exp} are
22568 automatically copied to the initrd.
22571 @node Bootloader Configuration
22572 @section Bootloader Configuration
22575 @cindex boot loader
22577 The operating system supports multiple bootloaders. The bootloader is
22578 configured using @code{bootloader-configuration} declaration. All the
22579 fields of this structure are bootloader agnostic except for one field,
22580 @code{bootloader} that indicates the bootloader to be configured and
22583 Some of the bootloaders do not honor every field of
22584 @code{bootloader-configuration}. For instance, the extlinux
22585 bootloader does not support themes and thus ignores the @code{theme}
22588 @deftp {Data Type} bootloader-configuration
22589 The type of a bootloader configuration declaration.
22593 @item @code{bootloader}
22594 @cindex EFI, bootloader
22595 @cindex UEFI, bootloader
22596 @cindex BIOS, bootloader
22597 The bootloader to use, as a @code{bootloader} object. For now
22598 @code{grub-bootloader}, @code{grub-efi-bootloader},
22599 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
22601 @vindex grub-efi-bootloader
22602 @code{grub-efi-bootloader} allows to boot on modern systems using the
22603 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
22604 use if the installation image contains a @file{/sys/firmware/efi} directory
22605 when you boot it on your system.
22607 @vindex grub-bootloader
22608 @code{grub-bootloader} allows you to boot in particular Intel-based machines
22609 in ``legacy'' BIOS mode.
22611 @cindex ARM, bootloaders
22612 @cindex AArch64, bootloaders
22613 Available bootloaders are described in @code{(gnu bootloader @dots{})}
22614 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
22615 of bootloaders for a wide range of ARM and AArch64 systems, using the
22616 @uref{http://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
22618 @item @code{target}
22619 This is a string denoting the target onto which to install the
22622 The interpretation depends on the bootloader in question. For
22623 @code{grub-bootloader}, for example, it should be a device name understood by
22624 the bootloader @command{installer} command, such as @code{/dev/sda} or
22625 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
22626 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
22627 system, usually @file{/boot/efi}.
22629 @item @code{menu-entries} (default: @code{()})
22630 A possibly empty list of @code{menu-entry} objects (see below), denoting
22631 entries to appear in the bootloader menu, in addition to the current
22632 system entry and the entry pointing to previous system generations.
22634 @item @code{default-entry} (default: @code{0})
22635 The index of the default boot menu entry. Index 0 is for the entry of the
22638 @item @code{timeout} (default: @code{5})
22639 The number of seconds to wait for keyboard input before booting. Set to
22640 0 to boot immediately, and to -1 to wait indefinitely.
22642 @item @code{theme} (default: @var{#f})
22643 The bootloader theme object describing the theme to use. If no theme
22644 is provided, some bootloaders might use a default theme, that's true
22647 @item @code{terminal-outputs} (default: @code{'gfxterm})
22648 The output terminals used for the bootloader boot menu, as a list of
22649 symbols. GRUB accepts the values: @code{console}, @code{serial},
22650 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
22651 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
22652 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
22653 configuration,,, grub,GNU GRUB manual}).
22655 @item @code{terminal-inputs} (default: @code{'()})
22656 The input terminals used for the bootloader boot menu, as a list of
22657 symbols. For GRUB, the default is the native platform terminal as
22658 determined at run-time. GRUB accepts the values: @code{console},
22659 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
22660 @code{usb_keyboard}. This field corresponds to the GRUB variable
22661 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
22664 @item @code{serial-unit} (default: @code{#f})
22665 The serial unit used by the bootloader, as an integer from 0 to 3.
22666 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
22667 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
22669 @item @code{serial-speed} (default: @code{#f})
22670 The speed of the serial interface, as an integer. For GRUB, the
22671 default value is chosen at run-time; currently GRUB chooses
22672 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
22679 Should you want to list additional boot menu entries @i{via} the
22680 @code{menu-entries} field above, you will need to create them with the
22681 @code{menu-entry} form. For example, imagine you want to be able to
22682 boot another distro (hard to imagine!), you can define a menu entry
22687 (label "The Other Distro")
22688 (linux "/boot/old/vmlinux-2.6.32")
22689 (linux-arguments '("root=/dev/sda2"))
22690 (initrd "/boot/old/initrd"))
22695 @deftp {Data Type} menu-entry
22696 The type of an entry in the bootloader menu.
22701 The label to show in the menu---e.g., @code{"GNU"}.
22704 The Linux kernel image to boot, for example:
22707 (file-append linux-libre "/bzImage")
22710 For GRUB, it is also possible to specify a device explicitly in the
22711 file path using GRUB's device naming convention (@pxref{Naming
22712 convention,,, grub, GNU GRUB manual}), for example:
22715 "(hd0,msdos1)/boot/vmlinuz"
22718 If the device is specified explicitly as above, then the @code{device}
22719 field is ignored entirely.
22721 @item @code{linux-arguments} (default: @code{()})
22722 The list of extra Linux kernel command-line arguments---e.g.,
22723 @code{("console=ttyS0")}.
22725 @item @code{initrd}
22726 A G-Expression or string denoting the file name of the initial RAM disk
22727 to use (@pxref{G-Expressions}).
22728 @item @code{device} (default: @code{#f})
22729 The device where the kernel and initrd are to be found---i.e., for GRUB,
22730 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
22732 This may be a file system label (a string), a file system UUID (a
22733 bytevector, @pxref{File Systems}), or @code{#f}, in which case
22734 the bootloader will search the device containing the file specified by
22735 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
22736 must @emph{not} be an OS device name such as @file{/dev/sda1}.
22741 @c FIXME: Write documentation once it's stable.
22742 Fow now only GRUB has theme support. GRUB themes are created using
22743 the @code{grub-theme} form, which is not documented yet.
22745 @defvr {Scheme Variable} %default-theme
22746 This is the default GRUB theme used by the operating system if no
22747 @code{theme} field is specified in @code{bootloader-configuration}
22750 It comes with a fancy background image displaying the GNU and Guix
22755 @node Invoking guix system
22756 @section Invoking @code{guix system}
22758 Once you have written an operating system declaration as seen in the
22759 previous section, it can be @dfn{instantiated} using the @command{guix
22760 system} command. The synopsis is:
22763 guix system @var{options}@dots{} @var{action} @var{file}
22766 @var{file} must be the name of a file containing an
22767 @code{operating-system} declaration. @var{action} specifies how the
22768 operating system is instantiated. Currently the following values are
22773 Display available service type definitions that match the given regular
22774 expressions, sorted by relevance:
22777 $ guix system search console font
22778 name: console-fonts
22779 location: gnu/services/base.scm:729:2
22780 extends: shepherd-root
22781 description: Install the given fonts on the specified ttys (fonts are
22782 + per virtual console on GNU/Linux). The value of this service is a list
22783 + of tty/font pairs like:
22785 + '(("tty1" . "LatGrkCyr-8x16"))
22789 location: gnu/services/base.scm:1048:2
22790 extends: shepherd-root
22791 description: Provide console login using the `mingetty' program.
22795 location: gnu/services/base.scm:775:2
22797 description: Provide a console log-in service as specified by its
22798 + configuration value, a `login-configuration' object.
22804 As for @command{guix package --search}, the result is written in
22805 @code{recutils} format, which makes it easy to filter the output
22806 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
22809 Build the operating system described in @var{file}, activate it, and
22810 switch to it@footnote{This action (and the related actions
22811 @code{switch-generation} and @code{roll-back}) are usable only on
22812 systems already running GuixSD.}.
22814 This effects all the configuration specified in @var{file}: user
22815 accounts, system services, global package list, setuid programs, etc.
22816 The command starts system services specified in @var{file} that are not
22817 currently running; if a service is currently running this command will
22818 arrange for it to be upgraded the next time it is stopped (e.g.@: by
22819 @code{herd stop X} or @code{herd restart X}).
22821 This command creates a new generation whose number is one greater than
22822 the current generation (as reported by @command{guix system
22823 list-generations}). If that generation already exists, it will be
22824 overwritten. This behavior mirrors that of @command{guix package}
22825 (@pxref{Invoking guix package}).
22827 It also adds a bootloader menu entry for the new OS configuration,
22828 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
22829 entries for older configurations to a submenu, allowing you to choose
22830 an older system generation at boot time should you need it.
22833 @c The paragraph below refers to the problem discussed at
22834 @c <http://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
22835 It is highly recommended to run @command{guix pull} once before you run
22836 @command{guix system reconfigure} for the first time (@pxref{Invoking
22837 guix pull}). Failing to do that you would see an older version of Guix
22838 once @command{reconfigure} has completed.
22841 @item switch-generation
22842 @cindex generations
22843 Switch to an existing system generation. This action atomically
22844 switches the system profile to the specified system generation. It
22845 also rearranges the system's existing bootloader menu entries. It
22846 makes the menu entry for the specified system generation the default,
22847 and it moves the entries for the other generatiors to a submenu, if
22848 supported by the bootloader being used. The next time the system
22849 boots, it will use the specified system generation.
22851 The bootloader itself is not being reinstalled when using this
22852 command. Thus, the installed bootloader is used with an updated
22853 configuration file.
22855 The target generation can be specified explicitly by its generation
22856 number. For example, the following invocation would switch to system
22860 guix system switch-generation 7
22863 The target generation can also be specified relative to the current
22864 generation with the form @code{+N} or @code{-N}, where @code{+3} means
22865 ``3 generations ahead of the current generation,'' and @code{-1} means
22866 ``1 generation prior to the current generation.'' When specifying a
22867 negative value such as @code{-1}, you must precede it with @code{--} to
22868 prevent it from being parsed as an option. For example:
22871 guix system switch-generation -- -1
22874 Currently, the effect of invoking this action is @emph{only} to switch
22875 the system profile to an existing generation and rearrange the
22876 bootloader menu entries. To actually start using the target system
22877 generation, you must reboot after running this action. In the future,
22878 it will be updated to do the same things as @command{reconfigure},
22879 like activating and deactivating services.
22881 This action will fail if the specified generation does not exist.
22884 @cindex rolling back
22885 Switch to the preceding system generation. The next time the system
22886 boots, it will use the preceding system generation. This is the inverse
22887 of @command{reconfigure}, and it is exactly the same as invoking
22888 @command{switch-generation} with an argument of @code{-1}.
22890 Currently, as with @command{switch-generation}, you must reboot after
22891 running this action to actually start using the preceding system
22895 Build the derivation of the operating system, which includes all the
22896 configuration files and programs needed to boot and run the system.
22897 This action does not actually install anything.
22900 Populate the given directory with all the files necessary to run the
22901 operating system specified in @var{file}. This is useful for first-time
22902 installations of GuixSD. For instance:
22905 guix system init my-os-config.scm /mnt
22908 copies to @file{/mnt} all the store items required by the configuration
22909 specified in @file{my-os-config.scm}. This includes configuration
22910 files, packages, and so on. It also creates other essential files
22911 needed for the system to operate correctly---e.g., the @file{/etc},
22912 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
22914 This command also installs bootloader on the target specified in
22915 @file{my-os-config}, unless the @option{--no-bootloader} option was
22919 @cindex virtual machine
22921 @anchor{guix system vm}
22922 Build a virtual machine that contains the operating system declared in
22923 @var{file}, and return a script to run that virtual machine (VM).
22924 Arguments given to the script are passed to QEMU as in the example
22925 below, which enables networking and requests 1@tie{}GiB of RAM for the
22929 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
22932 The VM shares its store with the host system.
22934 Additional file systems can be shared between the host and the VM using
22935 the @code{--share} and @code{--expose} command-line options: the former
22936 specifies a directory to be shared with write access, while the latter
22937 provides read-only access to the shared directory.
22939 The example below creates a VM in which the user's home directory is
22940 accessible read-only, and where the @file{/exchange} directory is a
22941 read-write mapping of @file{$HOME/tmp} on the host:
22944 guix system vm my-config.scm \
22945 --expose=$HOME --share=$HOME/tmp=/exchange
22948 On GNU/Linux, the default is to boot directly to the kernel; this has
22949 the advantage of requiring only a very tiny root disk image since the
22950 store of the host can then be mounted.
22952 The @code{--full-boot} option forces a complete boot sequence, starting
22953 with the bootloader. This requires more disk space since a root image
22954 containing at least the kernel, initrd, and bootloader data files must
22955 be created. The @code{--image-size} option can be used to specify the
22958 @cindex System images, creation in various formats
22959 @cindex Creating system images in various formats
22962 @itemx docker-image
22963 Return a virtual machine, disk image, or Docker image of the operating
22964 system declared in @var{file} that stands alone. By default,
22965 @command{guix system} estimates the size of the image needed to store
22966 the system, but you can use the @option{--image-size} option to specify
22967 a value. Docker images are built to contain exactly what they need, so
22968 the @option{--image-size} option is ignored in the case of
22969 @code{docker-image}.
22971 You can specify the root file system type by using the
22972 @option{--file-system-type} option. It defaults to @code{ext4}.
22974 When using @code{vm-image}, the returned image is in qcow2 format, which
22975 the QEMU emulator can efficiently use. @xref{Running GuixSD in a VM},
22976 for more information on how to run the image in a virtual machine.
22978 When using @code{disk-image}, a raw disk image is produced; it can be
22979 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
22980 the device corresponding to a USB stick, one can copy the image to it
22981 using the following command:
22984 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
22987 When using @code{docker-image}, a Docker image is produced. Guix builds
22988 the image from scratch, not from a pre-existing Docker base image. As a
22989 result, it contains @emph{exactly} what you define in the operating
22990 system configuration file. You can then load the image and launch a
22991 Docker container using commands like the following:
22994 image_id="$(docker load < guixsd-docker-image.tar.gz)"
22995 docker run -e GUIX_NEW_SYSTEM=/var/guix/profiles/system \\
22996 --entrypoint /var/guix/profiles/system/profile/bin/guile \\
22997 $image_id /var/guix/profiles/system/boot
23000 This command starts a new Docker container from the specified image. It
23001 will boot the GuixSD system in the usual manner, which means it will
23002 start any services you have defined in the operating system
23003 configuration. Depending on what you run in the Docker container, it
23004 may be necessary to give the container additional permissions. For
23005 example, if you intend to build software using Guix inside of the Docker
23006 container, you may need to pass the @option{--privileged} option to
23010 Return a script to run the operating system declared in @var{file}
23011 within a container. Containers are a set of lightweight isolation
23012 mechanisms provided by the kernel Linux-libre. Containers are
23013 substantially less resource-demanding than full virtual machines since
23014 the kernel, shared objects, and other resources can be shared with the
23015 host system; this also means they provide thinner isolation.
23017 Currently, the script must be run as root in order to support more than
23018 a single user and group. The container shares its store with the host
23021 As with the @code{vm} action (@pxref{guix system vm}), additional file
23022 systems to be shared between the host and container can be specified
23023 using the @option{--share} and @option{--expose} options:
23026 guix system container my-config.scm \
23027 --expose=$HOME --share=$HOME/tmp=/exchange
23031 This option requires Linux-libre 3.19 or newer.
23036 @var{options} can contain any of the common build options (@pxref{Common
23037 Build Options}). In addition, @var{options} can contain one of the
23041 @item --expression=@var{expr}
23042 @itemx -e @var{expr}
23043 Consider the operating-system @var{expr} evaluates to.
23044 This is an alternative to specifying a file which evaluates to an
23046 This is used to generate the GuixSD installer @pxref{Building the
23047 Installation Image}).
23049 @item --system=@var{system}
23050 @itemx -s @var{system}
23051 Attempt to build for @var{system} instead of the host system type.
23052 This works as per @command{guix build} (@pxref{Invoking guix build}).
23056 Return the derivation file name of the given operating system without
23059 @item --file-system-type=@var{type}
23060 @itemx -t @var{type}
23061 For the @code{disk-image} action, create a file system of the given
23062 @var{type} on the image.
23064 When this option is omitted, @command{guix system} uses @code{ext4}.
23066 @cindex ISO-9660 format
23067 @cindex CD image format
23068 @cindex DVD image format
23069 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
23070 for burning on CDs and DVDs.
23072 @item --image-size=@var{size}
23073 For the @code{vm-image} and @code{disk-image} actions, create an image
23074 of the given @var{size}. @var{size} may be a number of bytes, or it may
23075 include a unit as a suffix (@pxref{Block size, size specifications,,
23076 coreutils, GNU Coreutils}).
23078 When this option is omitted, @command{guix system} computes an estimate
23079 of the image size as a function of the size of the system declared in
23082 @item --root=@var{file}
23083 @itemx -r @var{file}
23084 Make @var{file} a symlink to the result, and register it as a garbage
23087 @item --skip-checks
23088 Skip pre-installation safety checks.
23090 By default, @command{guix system init} and @command{guix system
23091 reconfigure} perform safety checks: they make sure the file systems that
23092 appear in the @code{operating-system} declaration actually exist
23093 (@pxref{File Systems}), and that any Linux kernel modules that may be
23094 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
23095 RAM Disk}). Passing this option skips these tests altogether.
23098 @cindex on-error strategy
23099 @cindex error strategy
23100 @item --on-error=@var{strategy}
23101 Apply @var{strategy} when an error occurs when reading @var{file}.
23102 @var{strategy} may be one of the following:
23105 @item nothing-special
23106 Report the error concisely and exit. This is the default strategy.
23109 Likewise, but also display a backtrace.
23112 Report the error and enter Guile's debugger. From there, you can run
23113 commands such as @code{,bt} to get a backtrace, @code{,locals} to
23114 display local variable values, and more generally inspect the state of the
23115 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
23116 a list of available debugging commands.
23121 All the actions above, except @code{build} and @code{init},
23122 can use KVM support in the Linux-libre kernel. Specifically, if the
23123 machine has hardware virtualization support, the corresponding
23124 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
23125 must exist and be readable and writable by the user and by the
23126 build users of the daemon (@pxref{Build Environment Setup}).
23129 Once you have built, configured, re-configured, and re-re-configured
23130 your GuixSD installation, you may find it useful to list the operating
23131 system generations available on disk---and that you can choose from the
23132 bootloader boot menu:
23136 @item list-generations
23137 List a summary of each generation of the operating system available on
23138 disk, in a human-readable way. This is similar to the
23139 @option{--list-generations} option of @command{guix package}
23140 (@pxref{Invoking guix package}).
23142 Optionally, one can specify a pattern, with the same syntax that is used
23143 in @command{guix package --list-generations}, to restrict the list of
23144 generations displayed. For instance, the following command displays
23145 generations that are up to 10 days old:
23148 $ guix system list-generations 10d
23153 The @command{guix system} command has even more to offer! The following
23154 sub-commands allow you to visualize how your system services relate to
23157 @anchor{system-extension-graph}
23160 @item extension-graph
23161 Emit in Dot/Graphviz format to standard output the @dfn{service
23162 extension graph} of the operating system defined in @var{file}
23163 (@pxref{Service Composition}, for more information on service
23169 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
23172 produces a PDF file showing the extension relations among services.
23174 @anchor{system-shepherd-graph}
23175 @item shepherd-graph
23176 Emit in Dot/Graphviz format to standard output the @dfn{dependency
23177 graph} of shepherd services of the operating system defined in
23178 @var{file}. @xref{Shepherd Services}, for more information and for an
23183 @node Running GuixSD in a VM
23184 @section Running GuixSD in a Virtual Machine
23186 @cindex virtual machine
23187 To run GuixSD in a virtual machine (VM), one can either use the
23188 pre-built GuixSD VM image distributed at
23189 @indicateurl{https://alpha.gnu.org/gnu/guix/guixsd-vm-image-@value{VERSION}.@var{system}.xz}
23190 , or build their own virtual machine image using @command{guix system
23191 vm-image} (@pxref{Invoking guix system}). The returned image is in
23192 qcow2 format, which the @uref{http://qemu.org/, QEMU emulator} can
23196 If you built your own image, you must copy it out of the store
23197 (@pxref{The Store}) and give yourself permission to write to the copy
23198 before you can use it. When invoking QEMU, you must choose a system
23199 emulator that is suitable for your hardware platform. Here is a minimal
23200 QEMU invocation that will boot the result of @command{guix system
23201 vm-image} on x86_64 hardware:
23204 $ qemu-system-x86_64 \
23205 -net user -net nic,model=virtio \
23206 -enable-kvm -m 256 /tmp/qemu-image
23209 Here is what each of these options means:
23212 @item qemu-system-x86_64
23213 This specifies the hardware platform to emulate. This should match the
23217 Enable the unprivileged user-mode network stack. The guest OS can
23218 access the host but not vice versa. This is the simplest way to get the
23221 @item -net nic,model=virtio
23222 You must create a network interface of a given model. If you do not
23223 create a NIC, the boot will fail. Assuming your hardware platform is
23224 x86_64, you can get a list of available NIC models by running
23225 @command{qemu-system-x86_64 -net nic,model=help}.
23228 If your system has hardware virtualization extensions, enabling the
23229 virtual machine support (KVM) of the Linux kernel will make things run
23233 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
23234 which may be insufficient for some operations.
23236 @item /tmp/qemu-image
23237 The file name of the qcow2 image.
23240 The default @command{run-vm.sh} script that is returned by an invocation of
23241 @command{guix system vm} does not add a @command{-net user} flag by default.
23242 To get network access from within the vm add the @code{(dhcp-client-service)}
23243 to your system definition and start the VM using
23244 @command{`guix system vm config.scm` -net user}. An important caveat of using
23245 @command{-net user} for networking is that @command{ping} will not work, because
23246 it uses the ICMP protocol. You'll have to use a different command to check for
23247 network connectivity, for example @command{guix download}.
23249 @subsection Connecting Through SSH
23253 To enable SSH inside a VM you need to add a SSH server like @code{(dropbear-service)}
23254 or @code{(lsh-service)} to your VM. The @code{(lsh-service}) doesn't currently
23255 boot unsupervised. It requires you to type some characters to initialize the
23256 randomness generator. In addition you need to forward the SSH port, 22 by
23257 default, to the host. You can do this with
23260 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
23263 To connect to the VM you can run
23266 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
23269 The @command{-p} tells @command{ssh} the port you want to connect to.
23270 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
23271 every time you modify your @command{config.scm} file and the
23272 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
23273 connection to an unknown host every time you connect.
23275 @subsection Using @command{virt-viewer} with Spice
23277 As an alternative to the default @command{qemu} graphical client you can
23278 use the @command{remote-viewer} from the @command{virt-viewer} package. To
23279 connect pass the @command{-spice port=5930,disable-ticketing} flag to
23280 @command{qemu}. See previous section for further information on how to do this.
23282 Spice also allows you to do some nice stuff like share your clipboard with your
23283 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
23286 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
23287 -chardev spicevmc,name=vdagent,id=vdagent
23288 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
23289 name=com.redhat.spice.0
23292 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
23294 @node Defining Services
23295 @section Defining Services
23297 The previous sections show the available services and how one can combine
23298 them in an @code{operating-system} declaration. But how do we define
23299 them in the first place? And what is a service anyway?
23302 * Service Composition:: The model for composing services.
23303 * Service Types and Services:: Types and services.
23304 * Service Reference:: API reference.
23305 * Shepherd Services:: A particular type of service.
23308 @node Service Composition
23309 @subsection Service Composition
23313 Here we define a @dfn{service} as, broadly, something that extends the
23314 functionality of the operating system. Often a service is a process---a
23315 @dfn{daemon}---started when the system boots: a secure shell server, a
23316 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
23317 whose execution can be triggered by another daemon---e.g., an FTP server
23318 started by @command{inetd} or a D-Bus service activated by
23319 @command{dbus-daemon}. Occasionally, a service does not map to a
23320 daemon. For instance, the ``account'' service collects user accounts
23321 and makes sure they exist when the system runs; the ``udev'' service
23322 collects device management rules and makes them available to the eudev
23323 daemon; the @file{/etc} service populates the @file{/etc} directory
23326 @cindex service extensions
23327 GuixSD services are connected by @dfn{extensions}. For instance, the
23328 secure shell service @emph{extends} the Shepherd---the GuixSD
23329 initialization system, running as PID@tie{}1---by giving it the command
23330 lines to start and stop the secure shell daemon (@pxref{Networking
23331 Services, @code{lsh-service}}); the UPower service extends the D-Bus
23332 service by passing it its @file{.service} specification, and extends the
23333 udev service by passing it device management rules (@pxref{Desktop
23334 Services, @code{upower-service}}); the Guix daemon service extends the
23335 Shepherd by passing it the command lines to start and stop the daemon,
23336 and extends the account service by passing it a list of required build
23337 user accounts (@pxref{Base Services}).
23339 All in all, services and their ``extends'' relations form a directed
23340 acyclic graph (DAG). If we represent services as boxes and extensions
23341 as arrows, a typical system might provide something like this:
23343 @image{images/service-graph,,5in,Typical service extension graph.}
23345 @cindex system service
23346 At the bottom, we see the @dfn{system service}, which produces the
23347 directory containing everything to run and boot the system, as returned
23348 by the @command{guix system build} command. @xref{Service Reference},
23349 to learn about the other service types shown here.
23350 @xref{system-extension-graph, the @command{guix system extension-graph}
23351 command}, for information on how to generate this representation for a
23352 particular operating system definition.
23354 @cindex service types
23355 Technically, developers can define @dfn{service types} to express these
23356 relations. There can be any number of services of a given type on the
23357 system---for instance, a system running two instances of the GNU secure
23358 shell server (lsh) has two instances of @var{lsh-service-type}, with
23359 different parameters.
23361 The following section describes the programming interface for service
23362 types and services.
23364 @node Service Types and Services
23365 @subsection Service Types and Services
23367 A @dfn{service type} is a node in the DAG described above. Let us start
23368 with a simple example, the service type for the Guix build daemon
23369 (@pxref{Invoking guix-daemon}):
23372 (define guix-service-type
23376 (list (service-extension shepherd-root-service-type guix-shepherd-service)
23377 (service-extension account-service-type guix-accounts)
23378 (service-extension activation-service-type guix-activation)))
23379 (default-value (guix-configuration))))
23383 It defines three things:
23387 A name, whose sole purpose is to make inspection and debugging easier.
23390 A list of @dfn{service extensions}, where each extension designates the
23391 target service type and a procedure that, given the parameters of the
23392 service, returns a list of objects to extend the service of that type.
23394 Every service type has at least one service extension. The only
23395 exception is the @dfn{boot service type}, which is the ultimate service.
23398 Optionally, a default value for instances of this type.
23401 In this example, @var{guix-service-type} extends three services:
23404 @item shepherd-root-service-type
23405 The @var{guix-shepherd-service} procedure defines how the Shepherd
23406 service is extended. Namely, it returns a @code{<shepherd-service>}
23407 object that defines how @command{guix-daemon} is started and stopped
23408 (@pxref{Shepherd Services}).
23410 @item account-service-type
23411 This extension for this service is computed by @var{guix-accounts},
23412 which returns a list of @code{user-group} and @code{user-account}
23413 objects representing the build user accounts (@pxref{Invoking
23416 @item activation-service-type
23417 Here @var{guix-activation} is a procedure that returns a gexp, which is
23418 a code snippet to run at ``activation time''---e.g., when the service is
23422 A service of this type is instantiated like this:
23425 (service guix-service-type
23426 (guix-configuration
23428 (use-substitutes? #f)))
23431 The second argument to the @code{service} form is a value representing
23432 the parameters of this specific service instance.
23433 @xref{guix-configuration-type, @code{guix-configuration}}, for
23434 information about the @code{guix-configuration} data type. When the
23435 value is omitted, the default value specified by
23436 @code{guix-service-type} is used:
23439 (service guix-service-type)
23442 @var{guix-service-type} is quite simple because it extends other
23443 services but is not extensible itself.
23445 @c @subsubsubsection Extensible Service Types
23447 The service type for an @emph{extensible} service looks like this:
23450 (define udev-service-type
23451 (service-type (name 'udev)
23453 (list (service-extension shepherd-root-service-type
23454 udev-shepherd-service)))
23456 (compose concatenate) ;concatenate the list of rules
23457 (extend (lambda (config rules)
23459 (($ <udev-configuration> udev initial-rules)
23460 (udev-configuration
23461 (udev udev) ;the udev package to use
23462 (rules (append initial-rules rules)))))))))
23465 This is the service type for the
23466 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
23467 management daemon}. Compared to the previous example, in addition to an
23468 extension of @var{shepherd-root-service-type}, we see two new fields:
23472 This is the procedure to @dfn{compose} the list of extensions to
23473 services of this type.
23475 Services can extend the udev service by passing it lists of rules; we
23476 compose those extensions simply by concatenating them.
23479 This procedure defines how the value of the service is @dfn{extended} with
23480 the composition of the extensions.
23482 Udev extensions are composed into a list of rules, but the udev service
23483 value is itself a @code{<udev-configuration>} record. So here, we
23484 extend that record by appending the list of rules it contains to the
23485 list of contributed rules.
23488 This is a string giving an overview of the service type. The string can
23489 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
23490 @command{guix system search} command searches these strings and displays
23491 them (@pxref{Invoking guix system}).
23494 There can be only one instance of an extensible service type such as
23495 @var{udev-service-type}. If there were more, the
23496 @code{service-extension} specifications would be ambiguous.
23498 Still here? The next section provides a reference of the programming
23499 interface for services.
23501 @node Service Reference
23502 @subsection Service Reference
23504 We have seen an overview of service types (@pxref{Service Types and
23505 Services}). This section provides a reference on how to manipulate
23506 services and service types. This interface is provided by the
23507 @code{(gnu services)} module.
23509 @deffn {Scheme Procedure} service @var{type} [@var{value}]
23510 Return a new service of @var{type}, a @code{<service-type>} object (see
23511 below.) @var{value} can be any object; it represents the parameters of
23512 this particular service instance.
23514 When @var{value} is omitted, the default value specified by @var{type}
23515 is used; if @var{type} does not specify a default value, an error is
23518 For instance, this:
23521 (service openssh-service-type)
23525 is equivalent to this:
23528 (service openssh-service-type
23529 (openssh-configuration))
23532 In both cases the result is an instance of @code{openssh-service-type}
23533 with the default configuration.
23536 @deffn {Scheme Procedure} service? @var{obj}
23537 Return true if @var{obj} is a service.
23540 @deffn {Scheme Procedure} service-kind @var{service}
23541 Return the type of @var{service}---i.e., a @code{<service-type>} object.
23544 @deffn {Scheme Procedure} service-value @var{service}
23545 Return the value associated with @var{service}. It represents its
23549 Here is an example of how a service is created and manipulated:
23553 (service nginx-service-type
23554 (nginx-configuration
23556 (log-directory log-directory)
23557 (run-directory run-directory)
23558 (file config-file))))
23563 (eq? (service-kind s) nginx-service-type)
23567 The @code{modify-services} form provides a handy way to change the
23568 parameters of some of the services of a list such as
23569 @var{%base-services} (@pxref{Base Services, @code{%base-services}}). It
23570 evaluates to a list of services. Of course, you could always use
23571 standard list combinators such as @code{map} and @code{fold} to do that
23572 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
23573 @code{modify-services} simply provides a more concise form for this
23576 @deffn {Scheme Syntax} modify-services @var{services} @
23577 (@var{type} @var{variable} => @var{body}) @dots{}
23579 Modify the services listed in @var{services} according to the given
23580 clauses. Each clause has the form:
23583 (@var{type} @var{variable} => @var{body})
23586 where @var{type} is a service type---e.g.,
23587 @code{guix-service-type}---and @var{variable} is an identifier that is
23588 bound within the @var{body} to the service parameters---e.g., a
23589 @code{guix-configuration} instance---of the original service of that
23592 The @var{body} should evaluate to the new service parameters, which will
23593 be used to configure the new service. This new service will replace the
23594 original in the resulting list. Because a service's service parameters
23595 are created using @code{define-record-type*}, you can write a succinct
23596 @var{body} that evaluates to the new service parameters by using the
23597 @code{inherit} feature that @code{define-record-type*} provides.
23599 @xref{Using the Configuration System}, for example usage.
23603 Next comes the programming interface for service types. This is
23604 something you want to know when writing new service definitions, but not
23605 necessarily when simply looking for ways to customize your
23606 @code{operating-system} declaration.
23608 @deftp {Data Type} service-type
23609 @cindex service type
23610 This is the representation of a @dfn{service type} (@pxref{Service Types
23615 This is a symbol, used only to simplify inspection and debugging.
23617 @item @code{extensions}
23618 A non-empty list of @code{<service-extension>} objects (see below).
23620 @item @code{compose} (default: @code{#f})
23621 If this is @code{#f}, then the service type denotes services that cannot
23622 be extended---i.e., services that do not receive ``values'' from other
23625 Otherwise, it must be a one-argument procedure. The procedure is called
23626 by @code{fold-services} and is passed a list of values collected from
23627 extensions. It may return any single value.
23629 @item @code{extend} (default: @code{#f})
23630 If this is @code{#f}, services of this type cannot be extended.
23632 Otherwise, it must be a two-argument procedure: @code{fold-services}
23633 calls it, passing it the initial value of the service as the first
23634 argument and the result of applying @code{compose} to the extension
23635 values as the second argument. It must return a value that is a valid
23636 parameter value for the service instance.
23639 @xref{Service Types and Services}, for examples.
23642 @deffn {Scheme Procedure} service-extension @var{target-type} @
23644 Return a new extension for services of type @var{target-type}.
23645 @var{compute} must be a one-argument procedure: @code{fold-services}
23646 calls it, passing it the value associated with the service that provides
23647 the extension; it must return a valid value for the target service.
23650 @deffn {Scheme Procedure} service-extension? @var{obj}
23651 Return true if @var{obj} is a service extension.
23654 Occasionally, you might want to simply extend an existing service. This
23655 involves creating a new service type and specifying the extension of
23656 interest, which can be verbose; the @code{simple-service} procedure
23657 provides a shorthand for this.
23659 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
23660 Return a service that extends @var{target} with @var{value}. This works
23661 by creating a singleton service type @var{name}, of which the returned
23662 service is an instance.
23664 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
23668 (simple-service 'my-mcron-job mcron-service-type
23669 #~(job '(next-hour (3)) "guix gc -F 2G"))
23673 At the core of the service abstraction lies the @code{fold-services}
23674 procedure, which is responsible for ``compiling'' a list of services
23675 down to a single directory that contains everything needed to boot and
23676 run the system---the directory shown by the @command{guix system build}
23677 command (@pxref{Invoking guix system}). In essence, it propagates
23678 service extensions down the service graph, updating each node parameters
23679 on the way, until it reaches the root node.
23681 @deffn {Scheme Procedure} fold-services @var{services} @
23682 [#:target-type @var{system-service-type}]
23683 Fold @var{services} by propagating their extensions down to the root of
23684 type @var{target-type}; return the root service adjusted accordingly.
23687 Lastly, the @code{(gnu services)} module also defines several essential
23688 service types, some of which are listed below.
23690 @defvr {Scheme Variable} system-service-type
23691 This is the root of the service graph. It produces the system directory
23692 as returned by the @command{guix system build} command.
23695 @defvr {Scheme Variable} boot-service-type
23696 The type of the ``boot service'', which produces the @dfn{boot script}.
23697 The boot script is what the initial RAM disk runs when booting.
23700 @defvr {Scheme Variable} etc-service-type
23701 The type of the @file{/etc} service. This service is used to create
23702 files under @file{/etc} and can be extended by
23703 passing it name/file tuples such as:
23706 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
23709 In this example, the effect would be to add an @file{/etc/issue} file
23710 pointing to the given file.
23713 @defvr {Scheme Variable} setuid-program-service-type
23714 Type for the ``setuid-program service''. This service collects lists of
23715 executable file names, passed as gexps, and adds them to the set of
23716 setuid-root programs on the system (@pxref{Setuid Programs}).
23719 @defvr {Scheme Variable} profile-service-type
23720 Type of the service that populates the @dfn{system profile}---i.e., the
23721 programs under @file{/run/current-system/profile}. Other services can
23722 extend it by passing it lists of packages to add to the system profile.
23726 @node Shepherd Services
23727 @subsection Shepherd Services
23729 @cindex shepherd services
23731 @cindex init system
23732 The @code{(gnu services shepherd)} module provides a way to define
23733 services managed by the GNU@tie{}Shepherd, which is the GuixSD
23734 initialization system---the first process that is started when the
23735 system boots, also known as PID@tie{}1
23736 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
23738 Services in the Shepherd can depend on each other. For instance, the
23739 SSH daemon may need to be started after the syslog daemon has been
23740 started, which in turn can only happen once all the file systems have
23741 been mounted. The simple operating system defined earlier (@pxref{Using
23742 the Configuration System}) results in a service graph like this:
23744 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
23746 You can actually generate such a graph for any operating system
23747 definition using the @command{guix system shepherd-graph} command
23748 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
23750 The @var{%shepherd-root-service} is a service object representing
23751 PID@tie{}1, of type @var{shepherd-root-service-type}; it can be extended
23752 by passing it lists of @code{<shepherd-service>} objects.
23754 @deftp {Data Type} shepherd-service
23755 The data type representing a service managed by the Shepherd.
23758 @item @code{provision}
23759 This is a list of symbols denoting what the service provides.
23761 These are the names that may be passed to @command{herd start},
23762 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
23763 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
23764 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
23766 @item @code{requirements} (default: @code{'()})
23767 List of symbols denoting the Shepherd services this one depends on.
23769 @item @code{respawn?} (default: @code{#t})
23770 Whether to restart the service when it stops, for instance when the
23771 underlying process dies.
23774 @itemx @code{stop} (default: @code{#~(const #f)})
23775 The @code{start} and @code{stop} fields refer to the Shepherd's
23776 facilities to start and stop processes (@pxref{Service De- and
23777 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
23778 G-expressions that get expanded in the Shepherd configuration file
23779 (@pxref{G-Expressions}).
23781 @item @code{actions} (default: @code{'()})
23782 @cindex actions, of Shepherd services
23783 This is a list of @code{shepherd-action} objects (see below) defining
23784 @dfn{actions} supported by the service, in addition to the standard
23785 @code{start} and @code{stop} actions. Actions listed here become available as
23786 @command{herd} sub-commands:
23789 herd @var{action} @var{service} [@var{arguments}@dots{}]
23792 @item @code{documentation}
23793 A documentation string, as shown when running:
23796 herd doc @var{service-name}
23799 where @var{service-name} is one of the symbols in @var{provision}
23800 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
23802 @item @code{modules} (default: @var{%default-modules})
23803 This is the list of modules that must be in scope when @code{start} and
23804 @code{stop} are evaluated.
23809 @deftp {Data Type} shepherd-action
23810 This is the data type that defines additional actions implemented by a
23811 Shepherd service (see above).
23815 Symbol naming the action.
23817 @item documentation
23818 This is a documentation string for the action. It can be viewed by running:
23821 herd doc @var{service} action @var{action}
23825 This should be a gexp that evaluates to a procedure of at least one argument,
23826 which is the ``running value'' of the service (@pxref{Slots of services,,,
23827 shepherd, The GNU Shepherd Manual}).
23830 The following example defines an action called @code{say-hello} that kindly
23836 (documentation "Say hi!")
23837 (procedure #~(lambda (running . args)
23838 (format #t "Hello, friend! arguments: ~s\n"
23843 Assuming this action is added to the @code{example} service, then you can do:
23846 # herd say-hello example
23847 Hello, friend! arguments: ()
23848 # herd say-hello example a b c
23849 Hello, friend! arguments: ("a" "b" "c")
23852 This, as you can see, is a fairly sophisticated way to say hello.
23853 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
23857 @defvr {Scheme Variable} shepherd-root-service-type
23858 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
23860 This is the service type that extensions target when they want to create
23861 shepherd services (@pxref{Service Types and Services}, for an example).
23862 Each extension must pass a list of @code{<shepherd-service>}.
23865 @defvr {Scheme Variable} %shepherd-root-service
23866 This service represents PID@tie{}1.
23870 @node Documentation
23871 @chapter Documentation
23873 @cindex documentation, searching for
23874 @cindex searching for documentation
23875 @cindex Info, documentation format
23877 @cindex manual pages
23878 In most cases packages installed with Guix come with documentation.
23879 There are two main documentation formats: ``Info'', a browseable
23880 hypertext format used for GNU software, and ``manual pages'' (or ``man
23881 pages''), the linear documentation format traditionally found on Unix.
23882 Info manuals are accessed with the @command{info} command or with Emacs,
23883 and man pages are accessed using @command{man}.
23885 You can look for documentation of software installed on your system by
23886 keyword. For example, the following command searches for information
23887 about ``TLS'' in Info manuals:
23891 "(emacs)Network Security" -- STARTTLS
23892 "(emacs)Network Security" -- TLS
23893 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
23894 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
23899 The command below searches for the same keyword in man pages:
23903 SSL (7) - OpenSSL SSL/TLS library
23904 certtool (1) - GnuTLS certificate tool
23908 These searches are purely local to your computer so you have the
23909 guarantee that documentation you find corresponds to what you have
23910 actually installed, you can access it off-line, and your privacy is
23913 Once you have these results, you can view the relevant documentation by
23917 $ info "(gnutls)Core TLS API"
23927 Info manuals contain sections and indices as well as hyperlinks like
23928 those found in Web pages. The @command{info} reader (@pxref{Top, Info
23929 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
23930 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
23931 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
23932 Introduction}, for an introduction to Info navigation.
23934 @node Installing Debugging Files
23935 @chapter Installing Debugging Files
23937 @cindex debugging files
23938 Program binaries, as produced by the GCC compilers for instance, are
23939 typically written in the ELF format, with a section containing
23940 @dfn{debugging information}. Debugging information is what allows the
23941 debugger, GDB, to map binary code to source code; it is required to
23942 debug a compiled program in good conditions.
23944 The problem with debugging information is that is takes up a fair amount
23945 of disk space. For example, debugging information for the GNU C Library
23946 weighs in at more than 60 MiB. Thus, as a user, keeping all the
23947 debugging info of all the installed programs is usually not an option.
23948 Yet, space savings should not come at the cost of an impediment to
23949 debugging---especially in the GNU system, which should make it easier
23950 for users to exert their computing freedom (@pxref{GNU Distribution}).
23952 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
23953 mechanism that allows users to get the best of both worlds: debugging
23954 information can be stripped from the binaries and stored in separate
23955 files. GDB is then able to load debugging information from those files,
23956 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
23959 The GNU distribution takes advantage of this by storing debugging
23960 information in the @code{lib/debug} sub-directory of a separate package
23961 output unimaginatively called @code{debug} (@pxref{Packages with
23962 Multiple Outputs}). Users can choose to install the @code{debug} output
23963 of a package when they need it. For instance, the following command
23964 installs the debugging information for the GNU C Library and for GNU
23968 guix package -i glibc:debug guile:debug
23971 GDB must then be told to look for debug files in the user's profile, by
23972 setting the @code{debug-file-directory} variable (consider setting it
23973 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
23977 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
23980 From there on, GDB will pick up debugging information from the
23981 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
23983 In addition, you will most likely want GDB to be able to show the source
23984 code being debugged. To do that, you will have to unpack the source
23985 code of the package of interest (obtained with @code{guix build
23986 --source}, @pxref{Invoking guix build}), and to point GDB to that source
23987 directory using the @code{directory} command (@pxref{Source Path,
23988 @code{directory},, gdb, Debugging with GDB}).
23990 @c XXX: keep me up-to-date
23991 The @code{debug} output mechanism in Guix is implemented by the
23992 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
23993 opt-in---debugging information is available only for the packages
23994 with definitions explicitly declaring a @code{debug} output. This may be
23995 changed to opt-out in the future if our build farm servers can handle
23996 the load. To check whether a package has a @code{debug} output, use
23997 @command{guix package --list-available} (@pxref{Invoking guix package}).
24000 @node Security Updates
24001 @chapter Security Updates
24003 @cindex security updates
24004 @cindex security vulnerabilities
24005 Occasionally, important security vulnerabilities are discovered in software
24006 packages and must be patched. Guix developers try hard to keep track of
24007 known vulnerabilities and to apply fixes as soon as possible in the
24008 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
24009 containing only security updates.) The @command{guix lint} tool helps
24010 developers find out about vulnerable versions of software packages in the
24015 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
24016 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
24017 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
24021 @xref{Invoking guix lint}, for more information.
24024 As of version @value{VERSION}, the feature described below is considered
24028 Guix follows a functional
24029 package management discipline (@pxref{Introduction}), which implies
24030 that, when a package is changed, @emph{every package that depends on it}
24031 must be rebuilt. This can significantly slow down the deployment of
24032 fixes in core packages such as libc or Bash, since basically the whole
24033 distribution would need to be rebuilt. Using pre-built binaries helps
24034 (@pxref{Substitutes}), but deployment may still take more time than
24038 To address this, Guix implements @dfn{grafts}, a mechanism that allows
24039 for fast deployment of critical updates without the costs associated
24040 with a whole-distribution rebuild. The idea is to rebuild only the
24041 package that needs to be patched, and then to ``graft'' it onto packages
24042 explicitly installed by the user and that were previously referring to
24043 the original package. The cost of grafting is typically very low, and
24044 order of magnitudes lower than a full rebuild of the dependency chain.
24046 @cindex replacements of packages, for grafts
24047 For instance, suppose a security update needs to be applied to Bash.
24048 Guix developers will provide a package definition for the ``fixed''
24049 Bash, say @var{bash-fixed}, in the usual way (@pxref{Defining
24050 Packages}). Then, the original package definition is augmented with a
24051 @code{replacement} field pointing to the package containing the bug fix:
24058 (replacement bash-fixed)))
24061 From there on, any package depending directly or indirectly on Bash---as
24062 reported by @command{guix gc --requisites} (@pxref{Invoking guix
24063 gc})---that is installed is automatically ``rewritten'' to refer to
24064 @var{bash-fixed} instead of @var{bash}. This grafting process takes
24065 time proportional to the size of the package, usually less than a
24066 minute for an ``average'' package on a recent machine. Grafting is
24067 recursive: when an indirect dependency requires grafting, then grafting
24068 ``propagates'' up to the package that the user is installing.
24070 Currently, the length of the name and version of the graft and that of
24071 the package it replaces (@var{bash-fixed} and @var{bash} in the example
24072 above) must be equal. This restriction mostly comes from the fact that
24073 grafting works by patching files, including binary files, directly.
24074 Other restrictions may apply: for instance, when adding a graft to a
24075 package providing a shared library, the original shared library and its
24076 replacement must have the same @code{SONAME} and be binary-compatible.
24078 The @option{--no-grafts} command-line option allows you to forcefully
24079 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
24083 guix build bash --no-grafts
24087 returns the store file name of the original Bash, whereas:
24094 returns the store file name of the ``fixed'', replacement Bash. This
24095 allows you to distinguish between the two variants of Bash.
24097 To verify which Bash your whole profile refers to, you can run
24098 (@pxref{Invoking guix gc}):
24101 guix gc -R `readlink -f ~/.guix-profile` | grep bash
24105 @dots{} and compare the store file names that you get with those above.
24106 Likewise for a complete GuixSD system generation:
24109 guix gc -R `guix system build my-config.scm` | grep bash
24112 Lastly, to check which Bash running processes are using, you can use the
24113 @command{lsof} command:
24116 lsof | grep /gnu/store/.*bash
24120 @node Package Modules
24121 @chapter Package Modules
24123 From a programming viewpoint, the package definitions of the
24124 GNU distribution are provided by Guile modules in the @code{(gnu packages
24125 @dots{})} name space@footnote{Note that packages under the @code{(gnu
24126 packages @dots{})} module name space are not necessarily ``GNU
24127 packages''. This module naming scheme follows the usual Guile module
24128 naming convention: @code{gnu} means that these modules are distributed
24129 as part of the GNU system, and @code{packages} identifies modules that
24130 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
24131 Reference Manual}). For instance, the @code{(gnu packages emacs)}
24132 module exports a variable named @code{emacs}, which is bound to a
24133 @code{<package>} object (@pxref{Defining Packages}).
24135 The @code{(gnu packages @dots{})} module name space is
24136 automatically scanned for packages by the command-line tools. For
24137 instance, when running @code{guix package -i emacs}, all the @code{(gnu
24138 packages @dots{})} modules are scanned until one that exports a package
24139 object whose name is @code{emacs} is found. This package search
24140 facility is implemented in the @code{(gnu packages)} module.
24142 @cindex customization, of packages
24143 @cindex package module search path
24144 Users can store package definitions in modules with different
24145 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
24146 name and module name must match. For instance, the @code{(my-packages
24147 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
24148 relative to the load path specified with @option{--load-path} or
24149 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
24150 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
24151 these package definitions visible to the user interfaces:
24155 By adding the directory containing your package modules to the search path
24156 with the @code{-L} flag of @command{guix package} and other commands
24157 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
24158 environment variable described below.
24161 By defining a @dfn{channel} and configuring @command{guix pull} so that it
24162 pulls from it. A channel is essentially a Git repository containing package
24163 modules. @xref{Channels}, for more information on how to define and use
24167 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
24169 @defvr {Environment Variable} GUIX_PACKAGE_PATH
24170 This is a colon-separated list of directories to search for additional
24171 package modules. Directories listed in this variable take precedence
24172 over the own modules of the distribution.
24175 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
24176 each package is built based solely on other packages in the
24177 distribution. The root of this dependency graph is a small set of
24178 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
24179 bootstrap)} module. For more information on bootstrapping,
24180 @pxref{Bootstrapping}.
24182 @node Packaging Guidelines
24183 @chapter Packaging Guidelines
24185 @cindex packages, creating
24186 The GNU distribution is nascent and may well lack some of your favorite
24187 packages. This section describes how you can help make the distribution
24188 grow. @xref{Contributing}, for additional information on how you can
24191 Free software packages are usually distributed in the form of
24192 @dfn{source code tarballs}---typically @file{tar.gz} files that contain
24193 all the source files. Adding a package to the distribution means
24194 essentially two things: adding a @dfn{recipe} that describes how to
24195 build the package, including a list of other packages required to build
24196 it, and adding @dfn{package metadata} along with that recipe, such as a
24197 description and licensing information.
24199 In Guix all this information is embodied in @dfn{package definitions}.
24200 Package definitions provide a high-level view of the package. They are
24201 written using the syntax of the Scheme programming language; in fact,
24202 for each package we define a variable bound to the package definition,
24203 and export that variable from a module (@pxref{Package Modules}).
24204 However, in-depth Scheme knowledge is @emph{not} a prerequisite for
24205 creating packages. For more information on package definitions,
24206 @pxref{Defining Packages}.
24208 Once a package definition is in place, stored in a file in the Guix
24209 source tree, it can be tested using the @command{guix build} command
24210 (@pxref{Invoking guix build}). For example, assuming the new package is
24211 called @code{gnew}, you may run this command from the Guix build tree
24212 (@pxref{Running Guix Before It Is Installed}):
24215 ./pre-inst-env guix build gnew --keep-failed
24218 Using @code{--keep-failed} makes it easier to debug build failures since
24219 it provides access to the failed build tree. Another useful
24220 command-line option when debugging is @code{--log-file}, to access the
24223 If the package is unknown to the @command{guix} command, it may be that
24224 the source file contains a syntax error, or lacks a @code{define-public}
24225 clause to export the package variable. To figure it out, you may load
24226 the module from Guile to get more information about the actual error:
24229 ./pre-inst-env guile -c '(use-modules (gnu packages gnew))'
24232 Once your package builds correctly, please send us a patch
24233 (@pxref{Contributing}). Well, if you need help, we will be happy to
24234 help you too. Once the patch is committed in the Guix repository, the
24235 new package automatically gets built on the supported platforms by
24236 @url{http://hydra.gnu.org/jobset/gnu/master, our continuous integration
24239 @cindex substituter
24240 Users can obtain the new package definition simply by running
24241 @command{guix pull} (@pxref{Invoking guix pull}). When
24242 @code{@value{SUBSTITUTE-SERVER}} is done building the package, installing the
24243 package automatically downloads binaries from there
24244 (@pxref{Substitutes}). The only place where human intervention is
24245 needed is to review and apply the patch.
24249 * Software Freedom:: What may go into the distribution.
24250 * Package Naming:: What's in a name?
24251 * Version Numbers:: When the name is not enough.
24252 * Synopses and Descriptions:: Helping users find the right package.
24253 * Python Modules:: A touch of British comedy.
24254 * Perl Modules:: Little pearls.
24255 * Java Packages:: Coffee break.
24256 * Fonts:: Fond of fonts.
24259 @node Software Freedom
24260 @section Software Freedom
24262 @c Adapted from http://www.gnu.org/philosophy/philosophy.html.
24263 @cindex free software
24264 The GNU operating system has been developed so that users can have
24265 freedom in their computing. GNU is @dfn{free software}, meaning that
24266 users have the @url{http://www.gnu.org/philosophy/free-sw.html,four
24267 essential freedoms}: to run the program, to study and change the program
24268 in source code form, to redistribute exact copies, and to distribute
24269 modified versions. Packages found in the GNU distribution provide only
24270 software that conveys these four freedoms.
24272 In addition, the GNU distribution follow the
24273 @url{http://www.gnu.org/distros/free-system-distribution-guidelines.html,free
24274 software distribution guidelines}. Among other things, these guidelines
24275 reject non-free firmware, recommendations of non-free software, and
24276 discuss ways to deal with trademarks and patents.
24278 Some otherwise free upstream package sources contain a small and optional
24279 subset that violates the above guidelines, for instance because this subset
24280 is itself non-free code. When that happens, the offending items are removed
24281 with appropriate patches or code snippets in the @code{origin} form of the
24282 package (@pxref{Defining Packages}). This way, @code{guix
24283 build --source} returns the ``freed'' source rather than the unmodified
24287 @node Package Naming
24288 @section Package Naming
24290 @cindex package name
24291 A package has actually two names associated with it:
24292 First, there is the name of the @emph{Scheme variable}, the one following
24293 @code{define-public}. By this name, the package can be made known in the
24294 Scheme code, for instance as input to another package. Second, there is
24295 the string in the @code{name} field of a package definition. This name
24296 is used by package management commands such as
24297 @command{guix package} and @command{guix build}.
24299 Both are usually the same and correspond to the lowercase conversion of
24300 the project name chosen upstream, with underscores replaced with
24301 hyphens. For instance, GNUnet is available as @code{gnunet}, and
24302 SDL_net as @code{sdl-net}.
24304 We do not add @code{lib} prefixes for library packages, unless these are
24305 already part of the official project name. But @pxref{Python
24306 Modules} and @ref{Perl Modules} for special rules concerning modules for
24307 the Python and Perl languages.
24309 Font package names are handled differently, @pxref{Fonts}.
24312 @node Version Numbers
24313 @section Version Numbers
24315 @cindex package version
24316 We usually package only the latest version of a given free software
24317 project. But sometimes, for instance for incompatible library versions,
24318 two (or more) versions of the same package are needed. These require
24319 different Scheme variable names. We use the name as defined
24320 in @ref{Package Naming}
24321 for the most recent version; previous versions use the same name, suffixed
24322 by @code{-} and the smallest prefix of the version number that may
24323 distinguish the two versions.
24325 The name inside the package definition is the same for all versions of a
24326 package and does not contain any version number.
24328 For instance, the versions 2.24.20 and 3.9.12 of GTK+ may be packaged as follows:
24331 (define-public gtk+
24336 (define-public gtk+-2
24339 (version "2.24.20")
24342 If we also wanted GTK+ 3.8.2, this would be packaged as
24344 (define-public gtk+-3.8
24351 @c See <https://lists.gnu.org/archive/html/guix-devel/2016-01/msg00425.html>,
24352 @c for a discussion of what follows.
24353 @cindex version number, for VCS snapshots
24354 Occasionally, we package snapshots of upstream's version control system
24355 (VCS) instead of formal releases. This should remain exceptional,
24356 because it is up to upstream developers to clarify what the stable
24357 release is. Yet, it is sometimes necessary. So, what should we put in
24358 the @code{version} field?
24360 Clearly, we need to make the commit identifier of the VCS snapshot
24361 visible in the version string, but we also need to make sure that the
24362 version string is monotonically increasing so that @command{guix package
24363 --upgrade} can determine which version is newer. Since commit
24364 identifiers, notably with Git, are not monotonically increasing, we add
24365 a revision number that we increase each time we upgrade to a newer
24366 snapshot. The resulting version string looks like this:
24371 | | `-- upstream commit ID
24373 | `--- Guix package revision
24375 latest upstream version
24378 It is a good idea to strip commit identifiers in the @code{version}
24379 field to, say, 7 digits. It avoids an aesthetic annoyance (assuming
24380 aesthetics have a role to play here) as well as problems related to OS
24381 limits such as the maximum shebang length (127 bytes for the Linux
24382 kernel.) It is best to use the full commit identifiers in
24383 @code{origin}s, though, to avoid ambiguities. A typical package
24384 definition may look like this:
24388 (let ((commit "c3f29bc928d5900971f65965feaae59e1272a3f7")
24389 (revision "1")) ;Guix package revision
24391 (version (git-version "0.9" revision commit))
24394 (uri (git-reference
24395 (url "git://example.org/my-package.git")
24397 (sha256 (base32 "1mbikn@dots{}"))
24398 (file-name (git-file-name name version))))
24403 @node Synopses and Descriptions
24404 @section Synopses and Descriptions
24406 @cindex package description
24407 @cindex package synopsis
24408 As we have seen before, each package in GNU@tie{}Guix includes a
24409 synopsis and a description (@pxref{Defining Packages}). Synopses and
24410 descriptions are important: They are what @command{guix package
24411 --search} searches, and a crucial piece of information to help users
24412 determine whether a given package suits their needs. Consequently,
24413 packagers should pay attention to what goes into them.
24415 Synopses must start with a capital letter and must not end with a
24416 period. They must not start with ``a'' or ``the'', which usually does
24417 not bring anything; for instance, prefer ``File-frobbing tool'' over ``A
24418 tool that frobs files''. The synopsis should say what the package
24419 is---e.g., ``Core GNU utilities (file, text, shell)''---or what it is
24420 used for---e.g., the synopsis for GNU@tie{}grep is ``Print lines
24421 matching a pattern''.
24423 Keep in mind that the synopsis must be meaningful for a very wide
24424 audience. For example, ``Manipulate alignments in the SAM format''
24425 might make sense for a seasoned bioinformatics researcher, but might be
24426 fairly unhelpful or even misleading to a non-specialized audience. It
24427 is a good idea to come up with a synopsis that gives an idea of the
24428 application domain of the package. In this example, this might give
24429 something like ``Manipulate nucleotide sequence alignments'', which
24430 hopefully gives the user a better idea of whether this is what they are
24433 Descriptions should take between five and ten lines. Use full
24434 sentences, and avoid using acronyms without first introducing them.
24435 Please avoid marketing phrases such as ``world-leading'',
24436 ``industrial-strength'', and ``next-generation'', and avoid superlatives
24437 like ``the most advanced''---they are not helpful to users looking for a
24438 package and may even sound suspicious. Instead, try to be factual,
24439 mentioning use cases and features.
24441 @cindex Texinfo markup, in package descriptions
24442 Descriptions can include Texinfo markup, which is useful to introduce
24443 ornaments such as @code{@@code} or @code{@@dfn}, bullet lists, or
24444 hyperlinks (@pxref{Overview,,, texinfo, GNU Texinfo}). However you
24445 should be careful when using some characters for example @samp{@@} and
24446 curly braces which are the basic special characters in Texinfo
24447 (@pxref{Special Characters,,, texinfo, GNU Texinfo}). User interfaces
24448 such as @command{guix package --show} take care of rendering it
24451 Synopses and descriptions are translated by volunteers
24452 @uref{http://translationproject.org/domain/guix-packages.html, at the
24453 Translation Project} so that as many users as possible can read them in
24454 their native language. User interfaces search them and display them in
24455 the language specified by the current locale.
24457 To allow @command{xgettext} to extract them as translatable strings,
24458 synopses and descriptions @emph{must be literal strings}. This means
24459 that you cannot use @code{string-append} or @code{format} to construct
24465 (synopsis "This is translatable")
24466 (description (string-append "This is " "*not*" " translatable.")))
24469 Translation is a lot of work so, as a packager, please pay even more
24470 attention to your synopses and descriptions as every change may entail
24471 additional work for translators. In order to help them, it is possible
24472 to make recommendations or instructions visible to them by inserting
24473 special comments like this (@pxref{xgettext Invocation,,, gettext, GNU
24477 ;; TRANSLATORS: "X11 resize-and-rotate" should not be translated.
24478 (description "ARandR is designed to provide a simple visual front end
24479 for the X11 resize-and-rotate (RandR) extension. @dots{}")
24483 @node Python Modules
24484 @section Python Modules
24487 We currently package Python 2 and Python 3, under the Scheme variable names
24488 @code{python-2} and @code{python} as explained in @ref{Version Numbers}.
24489 To avoid confusion and naming clashes with other programming languages, it
24490 seems desirable that the name of a package for a Python module contains
24491 the word @code{python}.
24493 Some modules are compatible with only one version of Python, others with both.
24494 If the package Foo compiles only with Python 3, we name it
24495 @code{python-foo}; if it compiles only with Python 2, we name it
24496 @code{python2-foo}. If it is compatible with both versions, we create two
24497 packages with the corresponding names.
24499 If a project already contains the word @code{python}, we drop this;
24500 for instance, the module python-dateutil is packaged under the names
24501 @code{python-dateutil} and @code{python2-dateutil}. If the project name
24502 starts with @code{py} (e.g.@: @code{pytz}), we keep it and prefix it as
24505 @subsection Specifying Dependencies
24506 @cindex inputs, for Python packages
24508 Dependency information for Python packages is usually available in the
24509 package source tree, with varying degrees of accuracy: in the
24510 @file{setup.py} file, in @file{requirements.txt}, or in @file{tox.ini}.
24512 Your mission, when writing a recipe for a Python package, is to map
24513 these dependencies to the appropriate type of ``input'' (@pxref{package
24514 Reference, inputs}). Although the @code{pypi} importer normally does a
24515 good job (@pxref{Invoking guix import}), you may want to check the
24516 following check list to determine which dependency goes where.
24521 We currently package Python 2 with @code{setuptools} and @code{pip}
24522 installed like Python 3.4 has per default. Thus you don't need to
24523 specify either of these as an input. @command{guix lint} will warn you
24527 Python dependencies required at run time go into
24528 @code{propagated-inputs}. They are typically defined with the
24529 @code{install_requires} keyword in @file{setup.py}, or in the
24530 @file{requirements.txt} file.
24533 Python packages required only at build time---e.g., those listed with
24534 the @code{setup_requires} keyword in @file{setup.py}---or only for
24535 testing---e.g., those in @code{tests_require}---go into
24536 @code{native-inputs}. The rationale is that (1) they do not need to be
24537 propagated because they are not needed at run time, and (2) in a
24538 cross-compilation context, it's the ``native'' input that we'd want.
24540 Examples are the @code{pytest}, @code{mock}, and @code{nose} test
24541 frameworks. Of course if any of these packages is also required at
24542 run-time, it needs to go to @code{propagated-inputs}.
24545 Anything that does not fall in the previous categories goes to
24546 @code{inputs}, for example programs or C libraries required for building
24547 Python packages containing C extensions.
24550 If a Python package has optional dependencies (@code{extras_require}),
24551 it is up to you to decide whether to add them or not, based on their
24552 usefulness/overhead ratio (@pxref{Submitting Patches, @command{guix
24559 @section Perl Modules
24562 Perl programs standing for themselves are named as any other package,
24563 using the lowercase upstream name.
24564 For Perl packages containing a single class, we use the lowercase class name,
24565 replace all occurrences of @code{::} by dashes and prepend the prefix
24567 So the class @code{XML::Parser} becomes @code{perl-xml-parser}.
24568 Modules containing several classes keep their lowercase upstream name and
24569 are also prepended by @code{perl-}. Such modules tend to have the word
24570 @code{perl} somewhere in their name, which gets dropped in favor of the
24571 prefix. For instance, @code{libwww-perl} becomes @code{perl-libwww}.
24574 @node Java Packages
24575 @section Java Packages
24578 Java programs standing for themselves are named as any other package,
24579 using the lowercase upstream name.
24581 To avoid confusion and naming clashes with other programming languages,
24582 it is desirable that the name of a package for a Java package is
24583 prefixed with @code{java-}. If a project already contains the word
24584 @code{java}, we drop this; for instance, the package @code{ngsjava} is
24585 packaged under the name @code{java-ngs}.
24587 For Java packages containing a single class or a small class hierarchy,
24588 we use the lowercase class name, replace all occurrences of @code{.} by
24589 dashes and prepend the prefix @code{java-}. So the class
24590 @code{apache.commons.cli} becomes package
24591 @code{java-apache-commons-cli}.
24598 For fonts that are in general not installed by a user for typesetting
24599 purposes, or that are distributed as part of a larger software package,
24600 we rely on the general packaging rules for software; for instance, this
24601 applies to the fonts delivered as part of the X.Org system or fonts that
24602 are part of TeX Live.
24604 To make it easier for a user to search for fonts, names for other packages
24605 containing only fonts are constructed as follows, independently of the
24606 upstream package name.
24608 The name of a package containing only one font family starts with
24609 @code{font-}; it is followed by the foundry name and a dash @code{-}
24610 if the foundry is known, and the font family name, in which spaces are
24611 replaced by dashes (and as usual, all upper case letters are transformed
24613 For example, the Gentium font family by SIL is packaged under the name
24614 @code{font-sil-gentium}.
24616 For a package containing several font families, the name of the collection
24617 is used in the place of the font family name.
24618 For instance, the Liberation fonts consist of three families,
24619 Liberation Sans, Liberation Serif and Liberation Mono.
24620 These could be packaged separately under the names
24621 @code{font-liberation-sans} and so on; but as they are distributed together
24622 under a common name, we prefer to package them together as
24623 @code{font-liberation}.
24625 In the case where several formats of the same font family or font collection
24626 are packaged separately, a short form of the format, prepended by a dash,
24627 is added to the package name. We use @code{-ttf} for TrueType fonts,
24628 @code{-otf} for OpenType fonts and @code{-type1} for PostScript Type 1
24633 @node Bootstrapping
24634 @chapter Bootstrapping
24636 @c Adapted from the ELS 2013 paper.
24638 @cindex bootstrapping
24640 Bootstrapping in our context refers to how the distribution gets built
24641 ``from nothing''. Remember that the build environment of a derivation
24642 contains nothing but its declared inputs (@pxref{Introduction}). So
24643 there's an obvious chicken-and-egg problem: how does the first package
24644 get built? How does the first compiler get compiled? Note that this is
24645 a question of interest only to the curious hacker, not to the regular
24646 user, so you can shamelessly skip this section if you consider yourself
24647 a ``regular user''.
24649 @cindex bootstrap binaries
24650 The GNU system is primarily made of C code, with libc at its core. The
24651 GNU build system itself assumes the availability of a Bourne shell and
24652 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
24653 `grep'. Furthermore, build programs---programs that run
24654 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
24655 (@pxref{Derivations}). Consequently, to be able to build anything at
24656 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
24657 Binutils, libc, and the other packages mentioned above---the
24658 @dfn{bootstrap binaries}.
24660 These bootstrap binaries are ``taken for granted'', though we can also
24661 re-create them if needed (more on that later).
24663 @unnumberedsec Preparing to Use the Bootstrap Binaries
24665 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
24666 @c large image, it's hard to scroll. Oh well.
24667 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
24669 The figure above shows the very beginning of the dependency graph of the
24670 distribution, corresponding to the package definitions of the @code{(gnu
24671 packages bootstrap)} module. A similar figure can be generated with
24672 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
24675 guix graph -t derivation \
24676 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
24680 At this level of detail, things are
24681 slightly complex. First, Guile itself consists of an ELF executable,
24682 along with many source and compiled Scheme files that are dynamically
24683 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
24684 tarball shown in this graph. This tarball is part of Guix's ``source''
24685 distribution, and gets inserted into the store with @code{add-to-store}
24686 (@pxref{The Store}).
24688 But how do we write a derivation that unpacks this tarball and adds it
24689 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
24690 derivation---the first one that gets built---uses @code{bash} as its
24691 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
24692 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
24693 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
24694 the Guix source distribution, whose sole purpose is to allow the Guile
24695 tarball to be unpacked.
24697 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
24698 Guile that can be used to run subsequent build programs. Its first task
24699 is to download tarballs containing the other pre-built binaries---this
24700 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
24701 @code{ftp-client.scm} are used for this purpose. The
24702 @code{module-import.drv} derivations import those modules in a directory
24703 in the store, using the original layout. The
24704 @code{module-import-compiled.drv} derivations compile those modules, and
24705 write them in an output directory with the right layout. This
24706 corresponds to the @code{#:modules} argument of
24707 @code{build-expression->derivation} (@pxref{Derivations}).
24709 Finally, the various tarballs are unpacked by the
24710 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
24711 etc., at which point we have a working C tool chain.
24714 @unnumberedsec Building the Build Tools
24716 Bootstrapping is complete when we have a full tool chain that does not
24717 depend on the pre-built bootstrap tools discussed above. This
24718 no-dependency requirement is verified by checking whether the files of
24719 the final tool chain contain references to the @file{/gnu/store}
24720 directories of the bootstrap inputs. The process that leads to this
24721 ``final'' tool chain is described by the package definitions found in
24722 the @code{(gnu packages commencement)} module.
24724 The @command{guix graph} command allows us to ``zoom out'' compared to
24725 the graph above, by looking at the level of package objects instead of
24726 individual derivations---remember that a package may translate to
24727 several derivations, typically one derivation to download its source,
24728 one to build the Guile modules it needs, and one to actually build the
24729 package from source. The command:
24732 guix graph -t bag \
24733 -e '(@@@@ (gnu packages commencement)
24734 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
24738 produces the dependency graph leading to the ``final'' C
24739 library@footnote{You may notice the @code{glibc-intermediate} label,
24740 suggesting that it is not @emph{quite} final, but as a good
24741 approximation, we will consider it final.}, depicted below.
24743 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
24745 @c See <http://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
24746 The first tool that gets built with the bootstrap binaries is
24747 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
24748 for all the following packages. From there Findutils and Diffutils get
24751 Then come the first-stage Binutils and GCC, built as pseudo cross
24752 tools---i.e., with @code{--target} equal to @code{--host}. They are
24753 used to build libc. Thanks to this cross-build trick, this libc is
24754 guaranteed not to hold any reference to the initial tool chain.
24756 From there the final Binutils and GCC (not shown above) are built.
24758 from the final Binutils, and links programs against the just-built libc.
24759 This tool chain is used to build the other packages used by Guix and by
24760 the GNU Build System: Guile, Bash, Coreutils, etc.
24762 And voilà! At this point we have the complete set of build tools that
24763 the GNU Build System expects. These are in the @code{%final-inputs}
24764 variable of the @code{(gnu packages commencement)} module, and are
24765 implicitly used by any package that uses @code{gnu-build-system}
24766 (@pxref{Build Systems, @code{gnu-build-system}}).
24769 @unnumberedsec Building the Bootstrap Binaries
24771 @cindex bootstrap binaries
24772 Because the final tool chain does not depend on the bootstrap binaries,
24773 those rarely need to be updated. Nevertheless, it is useful to have an
24774 automated way to produce them, should an update occur, and this is what
24775 the @code{(gnu packages make-bootstrap)} module provides.
24777 The following command builds the tarballs containing the bootstrap
24778 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
24779 of Coreutils and other basic command-line tools):
24782 guix build bootstrap-tarballs
24785 The generated tarballs are those that should be referred to in the
24786 @code{(gnu packages bootstrap)} module mentioned at the beginning of
24789 Still here? Then perhaps by now you've started to wonder: when do we
24790 reach a fixed point? That is an interesting question! The answer is
24791 unknown, but if you would like to investigate further (and have
24792 significant computational and storage resources to do so), then let us
24795 @unnumberedsec Reducing the Set of Bootstrap Binaries
24797 Our bootstrap binaries currently include GCC, Guile, etc. That's a lot
24798 of binary code! Why is that a problem? It's a problem because these
24799 big chunks of binary code are practically non-auditable, which makes it
24800 hard to establish what source code produced them. Every unauditable
24801 binary also leaves us vulnerable to compiler backdoors as described by
24802 Ken Thompson in the 1984 paper @emph{Reflections on Trusting Trust}.
24804 This is mitigated by the fact that our bootstrap binaries were generated
24805 from an earlier Guix revision. Nevertheless it lacks the level of
24806 transparency that we get in the rest of the package dependency graph,
24807 where Guix always gives us a source-to-binary mapping. Thus, our goal
24808 is to reduce the set of bootstrap binaries to the bare minimum.
24810 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
24811 on-going projects to do that. One of these is about replacing the
24812 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
24813 of increasing complexity, which could be built from source starting from
24814 a simple and auditable assembler. Your help is welcome!
24818 @chapter Porting to a New Platform
24820 As discussed above, the GNU distribution is self-contained, and
24821 self-containment is achieved by relying on pre-built ``bootstrap
24822 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
24823 operating system kernel, CPU architecture, and application binary
24824 interface (ABI). Thus, to port the distribution to a platform that is
24825 not yet supported, one must build those bootstrap binaries, and update
24826 the @code{(gnu packages bootstrap)} module to use them on that platform.
24828 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
24829 When everything goes well, and assuming the GNU tool chain supports the
24830 target platform, this can be as simple as running a command like this
24834 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
24837 For this to work, the @code{glibc-dynamic-linker} procedure in
24838 @code{(gnu packages bootstrap)} must be augmented to return the right
24839 file name for libc's dynamic linker on that platform; likewise,
24840 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
24841 taught about the new platform.
24843 Once these are built, the @code{(gnu packages bootstrap)} module needs
24844 to be updated to refer to these binaries on the target platform. That
24845 is, the hashes and URLs of the bootstrap tarballs for the new platform
24846 must be added alongside those of the currently supported platforms. The
24847 bootstrap Guile tarball is treated specially: it is expected to be
24848 available locally, and @file{gnu/local.mk} has rules to download it for
24849 the supported architectures; a rule for the new platform must be added
24852 In practice, there may be some complications. First, it may be that the
24853 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
24854 above) is not recognized by all the GNU tools. Typically, glibc
24855 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
24856 configure flag (see @code{gcc.scm} for examples of how to handle this).
24857 Second, some of the required packages could fail to build for that
24858 platform. Lastly, the generated binaries could be broken for some
24861 @c *********************************************************************
24862 @include contributing.texi
24864 @c *********************************************************************
24865 @node Acknowledgments
24866 @chapter Acknowledgments
24868 Guix is based on the @uref{http://nixos.org/nix/, Nix package manager},
24869 which was designed and
24870 implemented by Eelco Dolstra, with contributions from other people (see
24871 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
24872 management, and promoted unprecedented features, such as transactional
24873 package upgrades and rollbacks, per-user profiles, and referentially
24874 transparent build processes. Without this work, Guix would not exist.
24876 The Nix-based software distributions, Nixpkgs and NixOS, have also been
24877 an inspiration for Guix.
24879 GNU@tie{}Guix itself is a collective work with contributions from a
24880 number of people. See the @file{AUTHORS} file in Guix for more
24881 information on these fine people. The @file{THANKS} file lists people
24882 who have helped by reporting bugs, taking care of the infrastructure,
24883 providing artwork and themes, making suggestions, and more---thank you!
24886 @c *********************************************************************
24887 @node GNU Free Documentation License
24888 @appendix GNU Free Documentation License
24889 @cindex license, GNU Free Documentation License
24890 @include fdl-1.3.texi
24892 @c *********************************************************************
24893 @node Concept Index
24894 @unnumbered Concept Index
24897 @node Programming Index
24898 @unnumbered Programming Index
24899 @syncodeindex tp fn
24900 @syncodeindex vr fn
24905 @c Local Variables:
24906 @c ispell-local-dictionary: "american";