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, 2019 Efraim Flashner@*
32 Copyright @copyright{} 2016 John Darrington@*
33 Copyright @copyright{} 2016, 2017 ng0@*
34 Copyright @copyright{} 2016, 2017, 2018, 2019 Jan Nieuwenhuizen@*
35 Copyright @copyright{} 2016 Julien Lepiller@*
36 Copyright @copyright{} 2016 Alex ter Weele@*
37 Copyright @copyright{} 2016, 2017, 2018, 2019 Christopher Baines@*
38 Copyright @copyright{} 2017, 2018 Clément Lassieur@*
39 Copyright @copyright{} 2017, 2018 Mathieu Othacehe@*
40 Copyright @copyright{} 2017 Federico Beffa@*
41 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
42 Copyright @copyright{} 2017 Thomas Danckaert@*
43 Copyright @copyright{} 2017 humanitiesNerd@*
44 Copyright @copyright{} 2017 Christopher Allan Webber@*
45 Copyright @copyright{} 2017, 2018 Marius Bakke@*
46 Copyright @copyright{} 2017 Hartmut Goebel@*
47 Copyright @copyright{} 2017 Maxim Cournoyer@*
48 Copyright @copyright{} 2017, 2018 Tobias Geerinckx-Rice@*
49 Copyright @copyright{} 2017 George Clemmer@*
50 Copyright @copyright{} 2017 Andy Wingo@*
51 Copyright @copyright{} 2017, 2018, 2019 Arun Isaac@*
52 Copyright @copyright{} 2017 nee@*
53 Copyright @copyright{} 2018 Rutger Helling@*
54 Copyright @copyright{} 2018 Oleg Pykhalov@*
55 Copyright @copyright{} 2018 Mike Gerwitz@*
56 Copyright @copyright{} 2018 Pierre-Antoine Rouby@*
57 Copyright @copyright{} 2018 Gábor Boskovits@*
58 Copyright @copyright{} 2018 Florian Pelz@*
59 Copyright @copyright{} 2018 Laura Lazzati@*
60 Copyright @copyright{} 2018 Alex Vong@*
62 Permission is granted to copy, distribute and/or modify this document
63 under the terms of the GNU Free Documentation License, Version 1.3 or
64 any later version published by the Free Software Foundation; with no
65 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
66 copy of the license is included in the section entitled ``GNU Free
67 Documentation License''.
70 @dircategory System administration
72 * Guix: (guix). Manage installed software and system configuration.
73 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
74 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
75 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
76 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
79 @dircategory Software development
81 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
82 * guix build: (guix)Invoking guix build. Building packages.
83 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
87 @title GNU Guix Reference Manual
88 @subtitle Using the GNU Guix Functional Package Manager
89 @author The GNU Guix Developers
92 @vskip 0pt plus 1filll
93 Edition @value{EDITION} @*
101 @c *********************************************************************
105 This document describes GNU Guix version @value{VERSION}, a functional
106 package management tool written for the GNU system.
108 @c TRANSLATORS: You can replace the following paragraph with information on
109 @c how to join your own translation team and how to report issues with the
111 This manual is also available in French (@pxref{Top,,, guix.fr, Manuel de
112 référence de GNU Guix}) and German (@pxref{Top,,, guix.de, Referenzhandbuch
113 zu GNU Guix}). If you would like to translate it in your native language,
115 @uref{https://translationproject.org/domain/guix-manual.html, Translation
119 * Introduction:: What is Guix about?
120 * Installation:: Installing Guix.
121 * System Installation:: Installing the whole operating system.
122 * Package Management:: Package installation, upgrade, etc.
123 * Development:: Guix-aided software development.
124 * Programming Interface:: Using Guix in Scheme.
125 * Utilities:: Package management commands.
126 * System Configuration:: Configuring the operating system.
127 * Documentation:: Browsing software user manuals.
128 * Installing Debugging Files:: Feeding the debugger.
129 * Security Updates:: Deploying security fixes quickly.
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 * Managing Software the Guix Way:: What's special.
145 * GNU Distribution:: The packages and tools.
149 * Binary Installation:: Getting Guix running in no time!
150 * Requirements:: Software needed to build and run Guix.
151 * Running the Test Suite:: Testing Guix.
152 * Setting Up the Daemon:: Preparing the build daemon's environment.
153 * Invoking guix-daemon:: Running the build daemon.
154 * Application Setup:: Application-specific setup.
156 Setting Up the Daemon
158 * Build Environment Setup:: Preparing the isolated build environment.
159 * Daemon Offload Setup:: Offloading builds to remote machines.
160 * SELinux Support:: Using an SELinux policy for the daemon.
164 * Limitations:: What you can expect.
165 * Hardware Considerations:: Supported hardware.
166 * USB Stick and DVD Installation:: Preparing the installation medium.
167 * Preparing for Installation:: Networking, partitioning, etc.
168 * Guided Graphical Installation:: Easy graphical installation.
169 * Manual Installation:: Manual installation for wizards.
170 * After System Installation:: When installation succeeded.
171 * Installing Guix in a VM:: Guix System playground.
172 * Building the Installation Image:: How this comes to be.
176 * Keyboard Layout and Networking and Partitioning:: Initial setup.
177 * Proceeding with the Installation:: Installing.
181 * Features:: How Guix will make your life brighter.
182 * Invoking guix package:: Package installation, removal, etc.
183 * Substitutes:: Downloading pre-built binaries.
184 * Packages with Multiple Outputs:: Single source package, multiple outputs.
185 * Invoking guix gc:: Running the garbage collector.
186 * Invoking guix pull:: Fetching the latest Guix and distribution.
187 * Channels:: Customizing the package collection.
188 * Inferiors:: Interacting with another revision of Guix.
189 * Invoking guix describe:: Display information about your Guix revision.
190 * Invoking guix archive:: Exporting and importing store files.
194 * Official Substitute Server:: One particular source of substitutes.
195 * Substitute Server Authorization:: How to enable or disable substitutes.
196 * Substitute Authentication:: How Guix verifies substitutes.
197 * Proxy Settings:: How to get substitutes via proxy.
198 * Substitution Failure:: What happens when substitution fails.
199 * On Trusting Binaries:: How can you trust that binary blob?
203 * Invoking guix environment:: Setting up development environments.
204 * Invoking guix pack:: Creating software bundles.
206 Programming Interface
208 * Package Modules:: Packages from the programmer's viewpoint.
209 * Defining Packages:: Defining new packages.
210 * Build Systems:: Specifying how packages are built.
211 * The Store:: Manipulating the package store.
212 * Derivations:: Low-level interface to package derivations.
213 * The Store Monad:: Purely functional interface to the store.
214 * G-Expressions:: Manipulating build expressions.
215 * Invoking guix repl:: Fiddling with Guix interactively.
219 * package Reference:: The package data type.
220 * origin Reference:: The origin data type.
224 * Invoking guix build:: Building packages from the command line.
225 * Invoking guix edit:: Editing package definitions.
226 * Invoking guix download:: Downloading a file and printing its hash.
227 * Invoking guix hash:: Computing the cryptographic hash of a file.
228 * Invoking guix import:: Importing package definitions.
229 * Invoking guix refresh:: Updating package definitions.
230 * Invoking guix lint:: Finding errors in package definitions.
231 * Invoking guix size:: Profiling disk usage.
232 * Invoking guix graph:: Visualizing the graph of packages.
233 * Invoking guix publish:: Sharing substitutes.
234 * Invoking guix challenge:: Challenging substitute servers.
235 * Invoking guix copy:: Copying to and from a remote store.
236 * Invoking guix container:: Process isolation.
237 * Invoking guix weather:: Assessing substitute availability.
238 * Invoking guix processes:: Listing client processes.
240 Invoking @command{guix build}
242 * Common Build Options:: Build options for most commands.
243 * Package Transformation Options:: Creating variants of packages.
244 * Additional Build Options:: Options specific to 'guix build'.
245 * Debugging Build Failures:: Real life packaging experience.
249 * Using the Configuration System:: Customizing your GNU system.
250 * operating-system Reference:: Detail of operating-system declarations.
251 * File Systems:: Configuring file system mounts.
252 * Mapped Devices:: Block device extra processing.
253 * User Accounts:: Specifying user accounts.
254 * Keyboard Layout:: How the system interprets key strokes.
255 * Locales:: Language and cultural convention settings.
256 * Services:: Specifying system services.
257 * Setuid Programs:: Programs running with root privileges.
258 * X.509 Certificates:: Authenticating HTTPS servers.
259 * Name Service Switch:: Configuring libc's name service switch.
260 * Initial RAM Disk:: Linux-Libre bootstrapping.
261 * Bootloader Configuration:: Configuring the boot loader.
262 * Invoking guix system:: Instantiating a system configuration.
263 * Running Guix in a VM:: How to run Guix System in a virtual machine.
264 * Defining Services:: Adding new service definitions.
268 * Base Services:: Essential system services.
269 * Scheduled Job Execution:: The mcron service.
270 * Log Rotation:: The rottlog service.
271 * Networking Services:: Network setup, SSH daemon, etc.
272 * X Window:: Graphical display.
273 * Printing Services:: Local and remote printer support.
274 * Desktop Services:: D-Bus and desktop services.
275 * Sound Services:: ALSA and Pulseaudio services.
276 * Database Services:: SQL databases, key-value stores, etc.
277 * Mail Services:: IMAP, POP3, SMTP, and all that.
278 * Messaging Services:: Messaging services.
279 * Telephony Services:: Telephony services.
280 * Monitoring Services:: Monitoring services.
281 * Kerberos Services:: Kerberos services.
282 * Web Services:: Web servers.
283 * Certificate Services:: TLS certificates via Let's Encrypt.
284 * DNS Services:: DNS daemons.
285 * VPN Services:: VPN daemons.
286 * Network File System:: NFS related services.
287 * Continuous Integration:: The Cuirass service.
288 * Power Management Services:: Extending battery life.
289 * Audio Services:: The MPD.
290 * Virtualization Services:: Virtualization services.
291 * Version Control Services:: Providing remote access to Git repositories.
292 * Game Services:: Game servers.
293 * Miscellaneous Services:: Other services.
297 * Service Composition:: The model for composing services.
298 * Service Types and Services:: Types and services.
299 * Service Reference:: API reference.
300 * Shepherd Services:: A particular type of service.
305 @c *********************************************************************
307 @chapter Introduction
310 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
311 using the international phonetic alphabet (IPA).} is a package
312 management tool for and distribution of the GNU system.
313 Guix makes it easy for unprivileged
314 users to install, upgrade, or remove software packages, to roll back to a
315 previous package set, to build packages from source, and generally
316 assists with the creation and maintenance of software environments.
319 @cindex GuixSD, now Guix System
320 @cindex Guix System Distribution, now Guix System
321 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
322 complements the available tools without interference (@pxref{Installation}),
323 or you can use it as a standalone operating system distribution,
324 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
325 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
326 group everything under the ``Guix'' banner since, after all, Guix System is
327 readily available through the @command{guix system} command, even if you're
328 using a different distro underneath!}. @xref{GNU Distribution}.
331 * Managing Software the Guix Way:: What's special.
332 * GNU Distribution:: The packages and tools.
335 @node Managing Software the Guix Way
336 @section Managing Software the Guix Way
338 @cindex user interfaces
339 Guix provides a command-line package management interface
340 (@pxref{Package Management}), tools to help with software development
341 (@pxref{Development}), command-line utilities for more advanced usage,
342 (@pxref{Utilities}), as well as Scheme programming interfaces
343 (@pxref{Programming Interface}).
345 Its @dfn{build daemon} is responsible for building packages on behalf of
346 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
347 binaries from authorized sources (@pxref{Substitutes}).
349 @cindex extensibility of the distribution
350 @cindex customization, of packages
351 Guix includes package definitions for many GNU and non-GNU packages, all
352 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
353 user's computing freedom}. It is @emph{extensible}: users can write
354 their own package definitions (@pxref{Defining Packages}) and make them
355 available as independent package modules (@pxref{Package Modules}). It
356 is also @emph{customizable}: users can @emph{derive} specialized package
357 definitions from existing ones, including from the command line
358 (@pxref{Package Transformation Options}).
360 @cindex functional package management
362 Under the hood, Guix implements the @dfn{functional package management}
363 discipline pioneered by Nix (@pxref{Acknowledgments}).
364 In Guix, the package build and installation process is seen
365 as a @emph{function}, in the mathematical sense. That function takes inputs,
366 such as build scripts, a compiler, and libraries, and
367 returns an installed package. As a pure function, its result depends
368 solely on its inputs---for instance, it cannot refer to software or
369 scripts that were not explicitly passed as inputs. A build function
370 always produces the same result when passed a given set of inputs. It
371 cannot alter the environment of the running system in
372 any way; for instance, it cannot create, modify, or delete files outside
373 of its build and installation directories. This is achieved by running
374 build processes in isolated environments (or @dfn{containers}), where only their
375 explicit inputs are visible.
378 The result of package build functions is @dfn{cached} in the file
379 system, in a special directory called @dfn{the store} (@pxref{The
380 Store}). Each package is installed in a directory of its own in the
381 store---by default under @file{/gnu/store}. The directory name contains
382 a hash of all the inputs used to build that package; thus, changing an
383 input yields a different directory name.
385 This approach is the foundation for the salient features of Guix: support
386 for transactional package upgrade and rollback, per-user installation, and
387 garbage collection of packages (@pxref{Features}).
390 @node GNU Distribution
391 @section GNU Distribution
394 Guix comes with a distribution of the GNU system consisting entirely of
395 free software@footnote{The term ``free'' here refers to the
396 @url{http://www.gnu.org/philosophy/free-sw.html,freedom provided to
397 users of that software}.}. The
398 distribution can be installed on its own (@pxref{System Installation}),
399 but it is also possible to install Guix as a package manager on top of
400 an installed GNU/Linux system (@pxref{Installation}). When we need to
401 distinguish between the two, we refer to the standalone distribution as
404 The distribution provides core GNU packages such as GNU libc, GCC, and
405 Binutils, as well as many GNU and non-GNU applications. The complete
406 list of available packages can be browsed
407 @url{http://www.gnu.org/software/guix/packages,on-line} or by
408 running @command{guix package} (@pxref{Invoking guix package}):
411 guix package --list-available
414 Our goal is to provide a practical 100% free software distribution of
415 Linux-based and other variants of GNU, with a focus on the promotion and
416 tight integration of GNU components, and an emphasis on programs and
417 tools that help users exert that freedom.
419 Packages are currently available on the following platforms:
424 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
427 Intel 32-bit architecture (IA32), Linux-Libre kernel;
430 ARMv7-A architecture with hard float, Thumb-2 and NEON,
431 using the EABI hard-float application binary interface (ABI),
432 and Linux-Libre kernel.
435 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel. This is
436 currently in an experimental stage, with limited support.
437 @xref{Contributing}, for how to help!
440 little-endian 64-bit MIPS processors, specifically the Loongson series,
441 n32 ABI, and Linux-Libre kernel.
445 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
446 configuration and Guix takes care of instantiating the configuration in a
447 transactional, reproducible, and stateless fashion (@pxref{System
448 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
449 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
450 Manual}), the well-known GNU utilities and tool chain, as well as the
451 graphical environment or system services of your choice.
453 Guix System is available on all the above platforms except
454 @code{mips64el-linux}.
457 For information on porting to other architectures or kernels,
460 Building this distribution is a cooperative effort, and you are invited
461 to join! @xref{Contributing}, for information about how you can help.
464 @c *********************************************************************
466 @chapter Installation
468 @cindex installing Guix
471 We recommend the use of this
472 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
473 shell installer script} to install Guix on top of a running GNU/Linux system,
474 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
475 with the installation of the package manager, which can be done on top of a
476 running GNU/Linux system. If, instead, you want to install the complete GNU
477 operating system, @pxref{System Installation}.} The script automates the
478 download, installation, and initial configuration of Guix. It should be run
482 @cindex foreign distro
483 @cindex directories related to foreign distro
484 When installed on a foreign distro, GNU@tie{}Guix complements the available
485 tools without interference. Its data lives exclusively in two directories,
486 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
487 such as @file{/etc}, are left untouched.
489 Once installed, Guix can be updated by running @command{guix pull}
490 (@pxref{Invoking guix pull}).
492 If you prefer to perform the installation steps manually or want to tweak
493 them, you may find the following subsections useful. They describe the
494 software requirements of Guix, as well as how to install it manually and get
498 * Binary Installation:: Getting Guix running in no time!
499 * Requirements:: Software needed to build and run Guix.
500 * Running the Test Suite:: Testing Guix.
501 * Setting Up the Daemon:: Preparing the build daemon's environment.
502 * Invoking guix-daemon:: Running the build daemon.
503 * Application Setup:: Application-specific setup.
506 @node Binary Installation
507 @section Binary Installation
509 @cindex installing Guix from binaries
510 @cindex installer script
511 This section describes how to install Guix on an arbitrary system from a
512 self-contained tarball providing binaries for Guix and for all its
513 dependencies. This is often quicker than installing from source, which
514 is described in the next sections. The only requirement is to have
517 Installing goes along these lines:
521 @cindex downloading Guix binary
522 Download the binary tarball from
523 @indicateurl{https://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz},
524 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
525 already running the kernel Linux, and so on.
527 @c The following is somewhat duplicated in ``System Installation''.
528 Make sure to download the associated @file{.sig} file and to verify the
529 authenticity of the tarball against it, along these lines:
532 $ wget https://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
533 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
536 If that command fails because you do not have the required public key,
537 then run this command to import it:
540 $ gpg --keyserver @value{KEY-SERVER} \
541 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
545 and rerun the @code{gpg --verify} command.
546 @c end authentication part
549 Now, you need to become the @code{root} user. Depending on your distribution,
550 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
554 # tar --warning=no-timestamp -xf \
555 guix-binary-@value{VERSION}.@var{system}.tar.xz
556 # mv var/guix /var/ && mv gnu /
559 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
560 The latter contains a ready-to-use profile for @code{root} (see next
563 Do @emph{not} unpack the tarball on a working Guix system since that
564 would overwrite its own essential files.
566 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
567 not emit warnings about ``implausibly old time stamps'' (such
568 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
570 They stem from the fact that all the
571 files in the archive have their modification time set to zero (which
572 means January 1st, 1970.) This is done on purpose to make sure the
573 archive content is independent of its creation time, thus making it
577 Make the profile available under @file{~root/.config/guix/current}, which is
578 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
581 # mkdir -p ~root/.config/guix
582 # ln -sf /var/guix/profiles/per-user/root/current-guix \
583 ~root/.config/guix/current
586 Source @file{etc/profile} to augment @code{PATH} and other relevant
587 environment variables:
590 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
591 source $GUIX_PROFILE/etc/profile
595 Create the group and user accounts for build users as explained below
596 (@pxref{Build Environment Setup}).
599 Run the daemon, and set it to automatically start on boot.
601 If your host distro uses the systemd init system, this can be achieved
604 @c Versions of systemd that supported symlinked service files are not
605 @c yet widely deployed, so we should suggest that users copy the service
608 @c See this thread for more information:
609 @c http://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
612 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
614 # systemctl start guix-daemon && systemctl enable guix-daemon
617 If your host distro uses the Upstart init system:
620 # initctl reload-configuration
621 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
626 Otherwise, you can still start the daemon manually with:
629 # ~root/.config/guix/current/bin/guix-daemon \
630 --build-users-group=guixbuild
634 Make the @command{guix} command available to other users on the machine,
638 # mkdir -p /usr/local/bin
640 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
643 It is also a good idea to make the Info version of this manual available
647 # mkdir -p /usr/local/share/info
648 # cd /usr/local/share/info
649 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
653 That way, assuming @file{/usr/local/share/info} is in the search path,
654 running @command{info guix} will open this manual (@pxref{Other Info
655 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
659 @cindex substitutes, authorization thereof
660 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
661 (@pxref{Substitutes}), authorize them:
664 # guix archive --authorize < \
665 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
669 Each user may need to perform a few additional steps to make their Guix
670 environment ready for use, @pxref{Application Setup}.
673 Voilà, the installation is complete!
675 You can confirm that Guix is working by installing a sample package into
679 # guix package -i hello
682 The @code{guix} package must remain available in @code{root}'s profile,
683 or it would become subject to garbage collection---in which case you
684 would find yourself badly handicapped by the lack of the @command{guix}
685 command. In other words, do not remove @code{guix} by running
686 @code{guix package -r guix}.
688 The binary installation tarball can be (re)produced and verified simply
689 by running the following command in the Guix source tree:
692 make guix-binary.@var{system}.tar.xz
696 ...@: which, in turn, runs:
699 guix pack -s @var{system} --localstatedir \
700 --profile-name=current-guix guix
703 @xref{Invoking guix pack}, for more info on this handy tool.
706 @section Requirements
708 This section lists requirements when building Guix from source. The
709 build procedure for Guix is the same as for other GNU software, and is
710 not covered here. Please see the files @file{README} and @file{INSTALL}
711 in the Guix source tree for additional details.
713 @cindex official website
714 GNU Guix is available for download from its website at
715 @url{https://www.gnu.org/software/guix/}.
717 GNU Guix depends on the following packages:
720 @item @url{http://gnu.org/software/guile/, GNU Guile}, version 2.2.x;
721 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
724 @uref{http://gnutls.org/, GnuTLS}, specifically its Guile bindings
725 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
726 Guile,, gnutls-guile, GnuTLS-Guile});
728 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
731 @c FIXME: Specify a version number once a release has been made.
732 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
734 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON};
735 @item @url{http://zlib.net, zlib};
736 @item @url{http://www.gnu.org/software/make/, GNU Make}.
739 The following dependencies are optional:
743 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
744 Support for build offloading (@pxref{Daemon Offload Setup}) and
745 @command{guix copy} (@pxref{Invoking guix copy}) depends on
746 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
747 version 0.10.2 or later.
750 When @url{http://www.bzip.org, libbz2} is available,
751 @command{guix-daemon} can use it to compress build logs.
754 Unless @code{--disable-daemon} was passed to @command{configure}, the
755 following packages are also needed:
758 @item @url{http://gnupg.org/, GNU libgcrypt};
759 @item @url{http://sqlite.org, SQLite 3};
760 @item @url{http://gcc.gnu.org, GCC's g++}, with support for the
764 @cindex state directory
765 When configuring Guix on a system that already has a Guix installation,
766 be sure to specify the same state directory as the existing installation
767 using the @code{--localstatedir} option of the @command{configure}
768 script (@pxref{Directory Variables, @code{localstatedir},, standards,
769 GNU Coding Standards}). The @command{configure} script protects against
770 unintended misconfiguration of @var{localstatedir} so you do not
771 inadvertently corrupt your store (@pxref{The Store}).
773 @cindex Nix, compatibility
774 When a working installation of @url{http://nixos.org/nix/, the Nix package
775 manager} is available, you
776 can instead configure Guix with @code{--disable-daemon}. In that case,
777 Nix replaces the three dependencies above.
779 Guix is compatible with Nix, so it is possible to share the same store
780 between both. To do so, you must pass @command{configure} not only the
781 same @code{--with-store-dir} value, but also the same
782 @code{--localstatedir} value. The latter is essential because it
783 specifies where the database that stores metadata about the store is
784 located, among other things. The default values for Nix are
785 @code{--with-store-dir=/nix/store} and @code{--localstatedir=/nix/var}.
786 Note that @code{--disable-daemon} is not required if
787 your goal is to share the store with Nix.
789 @node Running the Test Suite
790 @section Running the Test Suite
793 After a successful @command{configure} and @code{make} run, it is a good
794 idea to run the test suite. It can help catch issues with the setup or
795 environment, or bugs in Guix itself---and really, reporting test
796 failures is a good way to help improve the software. To run the test
803 Test cases can run in parallel: you can use the @code{-j} option of
804 GNU@tie{}make to speed things up. The first run may take a few minutes
805 on a recent machine; subsequent runs will be faster because the store
806 that is created for test purposes will already have various things in
809 It is also possible to run a subset of the tests by defining the
810 @code{TESTS} makefile variable as in this example:
813 make check TESTS="tests/store.scm tests/cpio.scm"
816 By default, tests results are displayed at a file level. In order to
817 see the details of every individual test cases, it is possible to define
818 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
821 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
824 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
825 @file{test-suite.log} file. Please specify the Guix version being used
826 as well as version numbers of the dependencies (@pxref{Requirements}) in
829 Guix also comes with a whole-system test suite that tests complete
830 Guix System instances. It can only run on systems where
831 Guix is already installed, using:
838 or, again, by defining @code{TESTS} to select a subset of tests to run:
841 make check-system TESTS="basic mcron"
844 These system tests are defined in the @code{(gnu tests @dots{})}
845 modules. They work by running the operating systems under test with
846 lightweight instrumentation in a virtual machine (VM). They can be
847 computationally intensive or rather cheap, depending on whether
848 substitutes are available for their dependencies (@pxref{Substitutes}).
849 Some of them require a lot of storage space to hold VM images.
851 Again in case of test failures, please send @email{bug-guix@@gnu.org}
854 @node Setting Up the Daemon
855 @section Setting Up the Daemon
858 Operations such as building a package or running the garbage collector
859 are all performed by a specialized process, the @dfn{build daemon}, on
860 behalf of clients. Only the daemon may access the store and its
861 associated database. Thus, any operation that manipulates the store
862 goes through the daemon. For instance, command-line tools such as
863 @command{guix package} and @command{guix build} communicate with the
864 daemon (@i{via} remote procedure calls) to instruct it what to do.
866 The following sections explain how to prepare the build daemon's
867 environment. See also @ref{Substitutes}, for information on how to allow
868 the daemon to download pre-built binaries.
871 * Build Environment Setup:: Preparing the isolated build environment.
872 * Daemon Offload Setup:: Offloading builds to remote machines.
873 * SELinux Support:: Using an SELinux policy for the daemon.
876 @node Build Environment Setup
877 @subsection Build Environment Setup
879 @cindex build environment
880 In a standard multi-user setup, Guix and its daemon---the
881 @command{guix-daemon} program---are installed by the system
882 administrator; @file{/gnu/store} is owned by @code{root} and
883 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
884 Guix tools to build packages or otherwise access the store, and the
885 daemon will do it on their behalf, ensuring that the store is kept in a
886 consistent state, and allowing built packages to be shared among users.
889 When @command{guix-daemon} runs as @code{root}, you may not want package
890 build processes themselves to run as @code{root} too, for obvious
891 security reasons. To avoid that, a special pool of @dfn{build users}
892 should be created for use by build processes started by the daemon.
893 These build users need not have a shell and a home directory: they will
894 just be used when the daemon drops @code{root} privileges in build
895 processes. Having several such users allows the daemon to launch
896 distinct build processes under separate UIDs, which guarantees that they
897 do not interfere with each other---an essential feature since builds are
898 regarded as pure functions (@pxref{Introduction}).
900 On a GNU/Linux system, a build user pool may be created like this (using
901 Bash syntax and the @code{shadow} commands):
903 @c See http://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
904 @c for why `-G' is needed.
906 # groupadd --system guixbuild
907 # for i in `seq -w 1 10`;
909 useradd -g guixbuild -G guixbuild \
910 -d /var/empty -s `which nologin` \
911 -c "Guix build user $i" --system \
917 The number of build users determines how many build jobs may run in
918 parallel, as specified by the @option{--max-jobs} option
919 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
920 @command{guix system vm} and related commands, you may need to add the
921 build users to the @code{kvm} group so they can access @file{/dev/kvm},
922 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
923 (@pxref{Invoking guix system}).
925 The @code{guix-daemon} program may then be run as @code{root} with the
926 following command@footnote{If your machine uses the systemd init system,
927 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
928 file in @file{/etc/systemd/system} will ensure that
929 @command{guix-daemon} is automatically started. Similarly, if your
930 machine uses the Upstart init system, drop the
931 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
932 file in @file{/etc/init}.}:
935 # guix-daemon --build-users-group=guixbuild
940 This way, the daemon starts build processes in a chroot, under one of
941 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
942 environment contains nothing but:
944 @c Keep this list in sync with libstore/build.cc! -----------------------
947 a minimal @code{/dev} directory, created mostly independently from the
948 host @code{/dev}@footnote{``Mostly'', because while the set of files
949 that appear in the chroot's @code{/dev} is fixed, most of these files
950 can only be created if the host has them.};
953 the @code{/proc} directory; it only shows the processes of the container
954 since a separate PID name space is used;
957 @file{/etc/passwd} with an entry for the current user and an entry for
961 @file{/etc/group} with an entry for the user's group;
964 @file{/etc/hosts} with an entry that maps @code{localhost} to
968 a writable @file{/tmp} directory.
971 You can influence the directory where the daemon stores build trees
972 @i{via} the @code{TMPDIR} environment variable. However, the build tree
973 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
974 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
975 This way, the value of @code{TMPDIR} does not leak inside build
976 environments, which avoids discrepancies in cases where build processes
977 capture the name of their build tree.
980 The daemon also honors the @code{http_proxy} environment variable for
981 HTTP downloads it performs, be it for fixed-output derivations
982 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
984 If you are installing Guix as an unprivileged user, it is still possible
985 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
986 However, build processes will not be isolated from one another, and not
987 from the rest of the system. Thus, build processes may interfere with
988 each other, and may access programs, libraries, and other files
989 available on the system---making it much harder to view them as
990 @emph{pure} functions.
993 @node Daemon Offload Setup
994 @subsection Using the Offload Facility
998 When desired, the build daemon can @dfn{offload} derivation builds to
999 other machines running Guix, using the @code{offload} @dfn{build
1000 hook}@footnote{This feature is available only when
1001 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1002 present.}. When that
1003 feature is enabled, a list of user-specified build machines is read from
1004 @file{/etc/guix/machines.scm}; every time a build is requested, for
1005 instance via @code{guix build}, the daemon attempts to offload it to one
1006 of the machines that satisfy the constraints of the derivation, in
1007 particular its system type---e.g., @file{x86_64-linux}. Missing
1008 prerequisites for the build are copied over SSH to the target machine,
1009 which then proceeds with the build; upon success the output(s) of the
1010 build are copied back to the initial machine.
1012 The @file{/etc/guix/machines.scm} file typically looks like this:
1015 (list (build-machine
1016 (name "eightysix.example.org")
1017 (system "x86_64-linux")
1018 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1020 (speed 2.)) ;incredibly fast!
1023 (name "meeps.example.org")
1024 (system "mips64el-linux")
1025 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1028 (string-append (getenv "HOME")
1029 "/.ssh/identity-for-guix"))))
1033 In the example above we specify a list of two build machines, one for
1034 the @code{x86_64} architecture and one for the @code{mips64el}
1037 In fact, this file is---not surprisingly!---a Scheme file that is
1038 evaluated when the @code{offload} hook is started. Its return value
1039 must be a list of @code{build-machine} objects. While this example
1040 shows a fixed list of build machines, one could imagine, say, using
1041 DNS-SD to return a list of potential build machines discovered in the
1042 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1043 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1046 @deftp {Data Type} build-machine
1047 This data type represents build machines to which the daemon may offload
1048 builds. The important fields are:
1053 The host name of the remote machine.
1056 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1059 The user account to use when connecting to the remote machine over SSH.
1060 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1061 allow non-interactive logins.
1064 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1065 This is used to authenticate the machine when we connect to it. It is a
1066 long string that looks like this:
1069 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1072 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1073 key can be found in a file such as
1074 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1076 If the machine is running the SSH daemon of GNU@tie{}lsh,
1077 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1078 similar file. It can be converted to the OpenSSH format using
1079 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1082 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1083 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1088 A number of optional fields may be specified:
1092 @item @code{port} (default: @code{22})
1093 Port number of SSH server on the machine.
1095 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1096 The SSH private key file to use when connecting to the machine, in
1097 OpenSSH format. This key must not be protected with a passphrase.
1099 Note that the default value is the private key @emph{of the root
1100 account}. Make sure it exists if you use the default.
1102 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1103 @itemx @code{compression-level} (default: @code{3})
1104 The SSH-level compression methods and compression level requested.
1106 Note that offloading relies on SSH compression to reduce bandwidth usage
1107 when transferring files to and from build machines.
1109 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1110 File name of the Unix-domain socket @command{guix-daemon} is listening
1113 @item @code{parallel-builds} (default: @code{1})
1114 The number of builds that may run in parallel on the machine.
1116 @item @code{speed} (default: @code{1.0})
1117 A ``relative speed factor''. The offload scheduler will tend to prefer
1118 machines with a higher speed factor.
1120 @item @code{features} (default: @code{'()})
1121 A list of strings denoting specific features supported by the machine.
1122 An example is @code{"kvm"} for machines that have the KVM Linux modules
1123 and corresponding hardware support. Derivations can request features by
1124 name, and they will be scheduled on matching build machines.
1129 The @command{guix} command must be in the search path on the build
1130 machines. You can check whether this is the case by running:
1133 ssh build-machine guix repl --version
1136 There is one last thing to do once @file{machines.scm} is in place. As
1137 explained above, when offloading, files are transferred back and forth
1138 between the machine stores. For this to work, you first need to
1139 generate a key pair on each machine to allow the daemon to export signed
1140 archives of files from the store (@pxref{Invoking guix archive}):
1143 # guix archive --generate-key
1147 Each build machine must authorize the key of the master machine so that
1148 it accepts store items it receives from the master:
1151 # guix archive --authorize < master-public-key.txt
1155 Likewise, the master machine must authorize the key of each build machine.
1157 All the fuss with keys is here to express pairwise mutual trust
1158 relations between the master and the build machines. Concretely, when
1159 the master receives files from a build machine (and @i{vice versa}), its
1160 build daemon can make sure they are genuine, have not been tampered
1161 with, and that they are signed by an authorized key.
1163 @cindex offload test
1164 To test whether your setup is operational, run this command on the
1171 This will attempt to connect to each of the build machines specified in
1172 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1173 available on each machine, attempt to export to the machine and import
1174 from it, and report any error in the process.
1176 If you want to test a different machine file, just specify it on the
1180 # guix offload test machines-qualif.scm
1183 Last, you can test the subset of the machines whose name matches a
1184 regular expression like this:
1187 # guix offload test machines.scm '\.gnu\.org$'
1190 @cindex offload status
1191 To display the current load of all build hosts, run this command on the
1195 # guix offload status
1199 @node SELinux Support
1200 @subsection SELinux Support
1202 @cindex SELinux, daemon policy
1203 @cindex mandatory access control, SELinux
1204 @cindex security, guix-daemon
1205 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1206 can be installed on a system where SELinux is enabled, in order to label
1207 Guix files and to specify the expected behavior of the daemon. Since
1208 Guix System does not provide an SELinux base policy, the daemon policy cannot
1209 be used on Guix System.
1211 @subsubsection Installing the SELinux policy
1212 @cindex SELinux, policy installation
1213 To install the policy run this command as root:
1216 semodule -i etc/guix-daemon.cil
1219 Then relabel the file system with @code{restorecon} or by a different
1220 mechanism provided by your system.
1222 Once the policy is installed, the file system has been relabeled, and
1223 the daemon has been restarted, it should be running in the
1224 @code{guix_daemon_t} context. You can confirm this with the following
1228 ps -Zax | grep guix-daemon
1231 Monitor the SELinux log files as you run a command like @code{guix build
1232 hello} to convince yourself that SELinux permits all necessary
1235 @subsubsection Limitations
1236 @cindex SELinux, limitations
1238 This policy is not perfect. Here is a list of limitations or quirks
1239 that should be considered when deploying the provided SELinux policy for
1244 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1245 operations involve contexts that have anything to do with
1246 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1247 but it would be preferrable to define socket rules for only this label.
1250 @code{guix gc} cannot access arbitrary links to profiles. By design,
1251 the file label of the destination of a symlink is independent of the
1252 file label of the link itself. Although all profiles under
1253 $localstatedir are labelled, the links to these profiles inherit the
1254 label of the directory they are in. For links in the user’s home
1255 directory this will be @code{user_home_t}. But for links from the root
1256 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1257 directory, etc, this won’t work. @code{guix gc} would be prevented from
1258 reading and following these links.
1261 The daemon’s feature to listen for TCP connections might no longer work.
1262 This might require extra rules, because SELinux treats network sockets
1263 differently from files.
1266 Currently all files with a name matching the regular expression
1267 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1268 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1269 that name in any profile would be permitted to run in the
1270 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1271 build a package that provides this executable and convince a user to
1272 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1273 At that point SELinux could not prevent it from accessing files that are
1274 allowed for processes in that domain.
1276 We could generate a much more restrictive policy at installation time,
1277 so that only the @emph{exact} file name of the currently installed
1278 @code{guix-daemon} executable would be labelled with
1279 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1280 The downside is that root would have to install or upgrade the policy at
1281 installation time whenever the Guix package that provides the
1282 effectively running @code{guix-daemon} executable is upgraded.
1285 @node Invoking guix-daemon
1286 @section Invoking @command{guix-daemon}
1288 The @command{guix-daemon} program implements all the functionality to
1289 access the store. This includes launching build processes, running the
1290 garbage collector, querying the availability of a build result, etc. It
1291 is normally run as @code{root} like this:
1294 # guix-daemon --build-users-group=guixbuild
1298 For details on how to set it up, @pxref{Setting Up the Daemon}.
1301 @cindex container, build environment
1302 @cindex build environment
1303 @cindex reproducible builds
1304 By default, @command{guix-daemon} launches build processes under
1305 different UIDs, taken from the build group specified with
1306 @code{--build-users-group}. In addition, each build process is run in a
1307 chroot environment that only contains the subset of the store that the
1308 build process depends on, as specified by its derivation
1309 (@pxref{Programming Interface, derivation}), plus a set of specific
1310 system directories. By default, the latter contains @file{/dev} and
1311 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1312 @dfn{container}: in addition to having its own file system tree, it has
1313 a separate mount name space, its own PID name space, network name space,
1314 etc. This helps achieve reproducible builds (@pxref{Features}).
1316 When the daemon performs a build on behalf of the user, it creates a
1317 build directory under @file{/tmp} or under the directory specified by
1318 its @code{TMPDIR} environment variable. This directory is shared with
1319 the container for the duration of the build, though within the container,
1320 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1322 The build directory is automatically deleted upon completion, unless the
1323 build failed and the client specified @option{--keep-failed}
1324 (@pxref{Invoking guix build, @option{--keep-failed}}).
1326 The daemon listens for connections and spawns one sub-process for each session
1327 started by a client (one of the @command{guix} sub-commands.) The
1328 @command{guix processes} command allows you to get an overview of the activity
1329 on your system by viewing each of the active sessions and clients.
1330 @xref{Invoking guix processes}, for more information.
1332 The following command-line options are supported:
1335 @item --build-users-group=@var{group}
1336 Take users from @var{group} to run build processes (@pxref{Setting Up
1337 the Daemon, build users}).
1339 @item --no-substitutes
1341 Do not use substitutes for build products. That is, always build things
1342 locally instead of allowing downloads of pre-built binaries
1343 (@pxref{Substitutes}).
1345 When the daemon runs with @code{--no-substitutes}, clients can still
1346 explicitly enable substitution @i{via} the @code{set-build-options}
1347 remote procedure call (@pxref{The Store}).
1349 @item --substitute-urls=@var{urls}
1350 @anchor{daemon-substitute-urls}
1351 Consider @var{urls} the default whitespace-separated list of substitute
1352 source URLs. When this option is omitted,
1353 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1355 This means that substitutes may be downloaded from @var{urls}, as long
1356 as they are signed by a trusted signature (@pxref{Substitutes}).
1359 @item --no-build-hook
1360 Do not use the @dfn{build hook}.
1362 The build hook is a helper program that the daemon can start and to
1363 which it submits build requests. This mechanism is used to offload
1364 builds to other machines (@pxref{Daemon Offload Setup}).
1366 @item --cache-failures
1367 Cache build failures. By default, only successful builds are cached.
1369 When this option is used, @command{guix gc --list-failures} can be used
1370 to query the set of store items marked as failed; @command{guix gc
1371 --clear-failures} removes store items from the set of cached failures.
1372 @xref{Invoking guix gc}.
1374 @item --cores=@var{n}
1376 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1379 The default value is @code{0}, but it may be overridden by clients, such
1380 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1383 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1384 in the build process, which can then use it to exploit internal
1385 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1387 @item --max-jobs=@var{n}
1389 Allow at most @var{n} build jobs in parallel. The default value is
1390 @code{1}. Setting it to @code{0} means that no builds will be performed
1391 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1392 Setup}), or simply fail.
1394 @item --max-silent-time=@var{seconds}
1395 When the build or substitution process remains silent for more than
1396 @var{seconds}, terminate it and report a build failure.
1398 The default value is @code{0}, which disables the timeout.
1400 The value specified here can be overridden by clients (@pxref{Common
1401 Build Options, @code{--max-silent-time}}).
1403 @item --timeout=@var{seconds}
1404 Likewise, when the build or substitution process lasts for more than
1405 @var{seconds}, terminate it and report a build failure.
1407 The default value is @code{0}, which disables the timeout.
1409 The value specified here can be overridden by clients (@pxref{Common
1410 Build Options, @code{--timeout}}).
1412 @item --rounds=@var{N}
1413 Build each derivation @var{n} times in a row, and raise an error if
1414 consecutive build results are not bit-for-bit identical. Note that this
1415 setting can be overridden by clients such as @command{guix build}
1416 (@pxref{Invoking guix build}).
1418 When used in conjunction with @option{--keep-failed}, the differing
1419 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1420 This makes it easy to look for differences between the two results.
1423 Produce debugging output.
1425 This is useful to debug daemon start-up issues, but then it may be
1426 overridden by clients, for example the @code{--verbosity} option of
1427 @command{guix build} (@pxref{Invoking guix build}).
1429 @item --chroot-directory=@var{dir}
1430 Add @var{dir} to the build chroot.
1432 Doing this may change the result of build processes---for instance if
1433 they use optional dependencies found in @var{dir} when it is available,
1434 and not otherwise. For that reason, it is not recommended to do so.
1435 Instead, make sure that each derivation declares all the inputs that it
1438 @item --disable-chroot
1439 Disable chroot builds.
1441 Using this option is not recommended since, again, it would allow build
1442 processes to gain access to undeclared dependencies. It is necessary,
1443 though, when @command{guix-daemon} is running under an unprivileged user
1446 @item --log-compression=@var{type}
1447 Compress build logs according to @var{type}, one of @code{gzip},
1448 @code{bzip2}, or @code{none}.
1450 Unless @code{--lose-logs} is used, all the build logs are kept in the
1451 @var{localstatedir}. To save space, the daemon automatically compresses
1452 them with bzip2 by default.
1454 @item --disable-deduplication
1455 @cindex deduplication
1456 Disable automatic file ``deduplication'' in the store.
1458 By default, files added to the store are automatically ``deduplicated'':
1459 if a newly added file is identical to another one found in the store,
1460 the daemon makes the new file a hard link to the other file. This can
1461 noticeably reduce disk usage, at the expense of slightly increased
1462 input/output load at the end of a build process. This option disables
1465 @item --gc-keep-outputs[=yes|no]
1466 Tell whether the garbage collector (GC) must keep outputs of live
1470 @cindex garbage collector roots
1471 When set to ``yes'', the GC will keep the outputs of any live derivation
1472 available in the store---the @code{.drv} files. The default is ``no'',
1473 meaning that derivation outputs are kept only if they are reachable from a GC
1474 root. @xref{Invoking guix gc}, for more on GC roots.
1476 @item --gc-keep-derivations[=yes|no]
1477 Tell whether the garbage collector (GC) must keep derivations
1478 corresponding to live outputs.
1480 When set to ``yes'', as is the case by default, the GC keeps
1481 derivations---i.e., @code{.drv} files---as long as at least one of their
1482 outputs is live. This allows users to keep track of the origins of
1483 items in their store. Setting it to ``no'' saves a bit of disk space.
1485 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1486 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1487 ``yes'' causes liveness to flow from derivations to outputs. When both are
1488 set to ``yes'', the effect is to keep all the build prerequisites (the
1489 sources, compiler, libraries, and other build-time tools) of live objects in
1490 the store, regardless of whether these prerequisites are reachable from a GC
1491 root. This is convenient for developers since it saves rebuilds or downloads.
1493 @item --impersonate-linux-2.6
1494 On Linux-based systems, impersonate Linux 2.6. This means that the
1495 kernel's @code{uname} system call will report 2.6 as the release number.
1497 This might be helpful to build programs that (usually wrongfully) depend
1498 on the kernel version number.
1501 Do not keep build logs. By default they are kept under
1502 @code{@var{localstatedir}/guix/log}.
1504 @item --system=@var{system}
1505 Assume @var{system} as the current system type. By default it is the
1506 architecture/kernel pair found at configure time, such as
1507 @code{x86_64-linux}.
1509 @item --listen=@var{endpoint}
1510 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1511 as the file name of a Unix-domain socket if it starts with
1512 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1513 host name or host name and port to listen to. Here are a few examples:
1516 @item --listen=/gnu/var/daemon
1517 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1518 creating it if needed.
1520 @item --listen=localhost
1521 @cindex daemon, remote access
1522 @cindex remote access to the daemon
1523 @cindex daemon, cluster setup
1524 @cindex clusters, daemon setup
1525 Listen for TCP connections on the network interface corresponding to
1526 @code{localhost}, on port 44146.
1528 @item --listen=128.0.0.42:1234
1529 Listen for TCP connections on the network interface corresponding to
1530 @code{128.0.0.42}, on port 1234.
1533 This option can be repeated multiple times, in which case
1534 @command{guix-daemon} accepts connections on all the specified
1535 endpoints. Users can tell client commands what endpoint to connect to
1536 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1537 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1540 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1541 @code{--listen=@var{host}} is suitable on local networks, such as
1542 clusters, where only trusted nodes may connect to the build daemon. In
1543 other cases where remote access to the daemon is needed, we recommend
1544 using Unix-domain sockets along with SSH.
1547 When @code{--listen} is omitted, @command{guix-daemon} listens for
1548 connections on the Unix-domain socket located at
1549 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1553 @node Application Setup
1554 @section Application Setup
1556 @cindex foreign distro
1557 When using Guix on top of GNU/Linux distribution other than Guix System---a
1558 so-called @dfn{foreign distro}---a few additional steps are needed to
1559 get everything in place. Here are some of them.
1563 @anchor{locales-and-locpath}
1564 @cindex locales, when not on Guix System
1566 @vindex GUIX_LOCPATH
1567 Packages installed @i{via} Guix will not use the locale data of the
1568 host system. Instead, you must first install one of the locale packages
1569 available with Guix and then define the @code{GUIX_LOCPATH} environment
1573 $ guix package -i glibc-locales
1574 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1577 Note that the @code{glibc-locales} package contains data for all the
1578 locales supported by the GNU@tie{}libc and weighs in at around
1579 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1580 limited to a few UTF-8 locales.
1582 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1583 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1584 Manual}). There are two important differences though:
1588 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1589 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1590 to make sure the programs of the foreign distro will not end up loading
1591 incompatible locale data.
1594 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1595 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1596 should your Guix profile contain a mixture of programs linked against
1597 different libc version, each libc version will only try to load locale
1598 data in the right format.
1601 This is important because the locale data format used by different libc
1602 versions may be incompatible.
1604 @subsection Name Service Switch
1606 @cindex name service switch, glibc
1607 @cindex NSS (name service switch), glibc
1608 @cindex nscd (name service caching daemon)
1609 @cindex name service caching daemon (nscd)
1610 When using Guix on a foreign distro, we @emph{strongly recommend} that
1611 the system run the GNU C library's @dfn{name service cache daemon},
1612 @command{nscd}, which should be listening on the
1613 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1614 installed with Guix may fail to look up host names or user accounts, or
1615 may even crash. The next paragraphs explain why.
1617 @cindex @file{nsswitch.conf}
1618 The GNU C library implements a @dfn{name service switch} (NSS), which is
1619 an extensible mechanism for ``name lookups'' in general: host name
1620 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1621 The GNU C Library Reference Manual}).
1623 @cindex Network information service (NIS)
1624 @cindex NIS (Network information service)
1625 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1626 lookup implementations: for example, the @code{nss-mdns} plugin allow
1627 resolution of @code{.local} host names, the @code{nis} plugin allows
1628 user account lookup using the Network information service (NIS), and so
1629 on. These extra ``lookup services'' are configured system-wide in
1630 @file{/etc/nsswitch.conf}, and all the programs running on the system
1631 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1634 When they perform a name lookup---for instance by calling the
1635 @code{getaddrinfo} function in C---applications first try to connect to
1636 the nscd; on success, nscd performs name lookups on their behalf. If
1637 the nscd is not running, then they perform the name lookup by
1638 themselves, by loading the name lookup services into their own address
1639 space and running it. These name lookup services---the
1640 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1641 the host system's C library, rather than from the C library the
1642 application is linked against (the C library coming from Guix).
1644 And this is where the problem is: if your application is linked against
1645 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1646 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1647 likely crash or have its name lookups fail unexpectedly.
1649 Running @command{nscd} on the system, among other advantages, eliminates
1650 this binary incompatibility problem because those @code{libnss_*.so}
1651 files are loaded in the @command{nscd} process, not in applications
1654 @subsection X11 Fonts
1657 The majority of graphical applications use Fontconfig to locate and
1658 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1659 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1660 by default. Thus, to allow graphical applications installed with Guix
1661 to display fonts, you have to install fonts with Guix as well.
1662 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1663 @code{font-gnu-freefont-ttf}.
1665 To display text written in Chinese languages, Japanese, or Korean in
1666 graphical applications, consider installing
1667 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1668 has multiple outputs, one per language family (@pxref{Packages with
1669 Multiple Outputs}). For instance, the following command installs fonts
1670 for Chinese languages:
1673 guix package -i font-adobe-source-han-sans:cn
1676 @cindex @code{xterm}
1677 Older programs such as @command{xterm} do not use Fontconfig and instead
1678 rely on server-side font rendering. Such programs require to specify a
1679 full name of a font using XLFD (X Logical Font Description), like this:
1682 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1685 To be able to use such full names for the TrueType fonts installed in
1686 your Guix profile, you need to extend the font path of the X server:
1688 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1689 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1691 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1694 @cindex @code{xlsfonts}
1695 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1696 to make sure your TrueType fonts are listed there.
1698 @cindex @code{fc-cache}
1700 After installing fonts you may have to refresh the font cache to use
1701 them in applications. The same applies when applications installed via
1702 Guix do not seem to find fonts. To force rebuilding of the font cache
1703 run @code{fc-cache -f}. The @code{fc-cache} command is provided by the
1704 @code{fontconfig} package.
1706 @subsection X.509 Certificates
1708 @cindex @code{nss-certs}
1709 The @code{nss-certs} package provides X.509 certificates, which allow
1710 programs to authenticate Web servers accessed over HTTPS.
1712 When using Guix on a foreign distro, you can install this package and
1713 define the relevant environment variables so that packages know where to
1714 look for certificates. @xref{X.509 Certificates}, for detailed
1717 @subsection Emacs Packages
1719 @cindex @code{emacs}
1720 When you install Emacs packages with Guix, the elisp files may be placed
1721 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1723 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1724 directory exists because potentially there may exist thousands of Emacs
1725 packages and storing all their files in a single directory may not be
1726 reliable (because of name conflicts). So we think using a separate
1727 directory for each package is a good idea. It is very similar to how
1728 the Emacs package system organizes the file structure (@pxref{Package
1729 Files,,, emacs, The GNU Emacs Manual}).
1731 By default, Emacs (installed with Guix) ``knows'' where these packages
1732 are placed, so you do not need to perform any configuration. If, for
1733 some reason, you want to avoid auto-loading Emacs packages installed
1734 with Guix, you can do so by running Emacs with @code{--no-site-file}
1735 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1737 @subsection The GCC toolchain
1742 Guix offers individual compiler packages such as @code{gcc} but if you
1743 are in need of a complete toolchain for compiling and linking source
1744 code what you really want is the @code{gcc-toolchain} package. This
1745 package provides a complete GCC toolchain for C/C++ development,
1746 including GCC itself, the GNU C Library (headers and binaries, plus
1747 debugging symbols in the @code{debug} output), Binutils, and a linker
1750 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1751 passed to the linker, add corresponding @code{-rpath} arguments, and
1752 invoke the actual linker with this new set of arguments. You can instruct the
1753 wrapper to refuse to link against libraries not in the store by setting the
1754 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
1758 @c *********************************************************************
1759 @node System Installation
1760 @chapter System Installation
1762 @cindex installing Guix System
1763 @cindex Guix System, installation
1764 This section explains how to install Guix System
1765 on a machine. Guix, as a package manager, can
1766 also be installed on top of a running GNU/Linux system,
1767 @pxref{Installation}.
1771 @c This paragraph is for people reading this from tty2 of the
1772 @c installation image.
1773 You are reading this documentation with an Info reader. For details on
1774 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1775 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1776 Info}. Hit @kbd{l} afterwards to come back here.
1778 Alternately, run @command{info info} in another tty to keep the manual
1784 * Limitations:: What you can expect.
1785 * Hardware Considerations:: Supported hardware.
1786 * USB Stick and DVD Installation:: Preparing the installation medium.
1787 * Preparing for Installation:: Networking, partitioning, etc.
1788 * Guided Graphical Installation:: Easy graphical installation.
1789 * Manual Installation:: Manual installation for wizards.
1790 * After System Installation:: When installation succeeded.
1791 * Installing Guix in a VM:: Guix System playground.
1792 * Building the Installation Image:: How this comes to be.
1796 @section Limitations
1798 As of version @value{VERSION}, Guix System is
1799 not production-ready. It may contain bugs and lack important
1800 features. Thus, if you are looking for a stable production system that
1801 respects your freedom as a computer user, a good solution at this point
1802 is to consider @url{http://www.gnu.org/distros/free-distros.html, one of
1803 the more established GNU/Linux distributions}. We hope you can soon switch
1804 to the Guix System without fear, of course. In the meantime, you can
1805 also keep using your distribution and try out the package manager on top
1806 of it (@pxref{Installation}).
1808 Before you proceed with the installation, be aware of the following
1809 noteworthy limitations applicable to version @value{VERSION}:
1813 The installation process does not include a graphical user interface and
1814 requires familiarity with GNU/Linux (see the following subsections to
1815 get a feel of what that means.)
1818 Support for the Logical Volume Manager (LVM) is missing.
1821 More and more system services are provided (@pxref{Services}), but some
1825 More than 8,500 packages are available, but you might
1826 occasionally find that a useful package is missing.
1829 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1830 as well as a number of X11 window managers. However, some graphical
1831 applications may be missing, as well as KDE.
1834 You have been warned! But more than a disclaimer, this is an invitation
1835 to report issues (and success stories!), and to join us in improving it.
1836 @xref{Contributing}, for more info.
1839 @node Hardware Considerations
1840 @section Hardware Considerations
1842 @cindex hardware support on Guix System
1843 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1844 builds around the kernel Linux-libre, which means that only hardware for
1845 which free software drivers and firmware exist is supported. Nowadays,
1846 a wide range of off-the-shelf hardware is supported on
1847 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1848 Ethernet controllers. Unfortunately, there are still areas where
1849 hardware vendors deny users control over their own computing, and such
1850 hardware is not supported on Guix System.
1852 @cindex WiFi, hardware support
1853 One of the main areas where free drivers or firmware are lacking is WiFi
1854 devices. WiFi devices known to work include those using Atheros chips
1855 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1856 driver, and those using Broadcom/AirForce chips (BCM43xx with
1857 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1858 Linux-libre driver. Free firmware exists for both and is available
1859 out-of-the-box on Guix System, as part of @var{%base-firmware}
1860 (@pxref{operating-system Reference, @code{firmware}}).
1862 @cindex RYF, Respects Your Freedom
1863 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1864 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1865 certification program for hardware products that respect your freedom
1866 and your privacy and ensure that you have control over your device. We
1867 encourage you to check the list of RYF-certified devices.
1869 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1870 web site. It contains a catalog of hardware devices with information
1871 about their support in GNU/Linux.
1874 @node USB Stick and DVD Installation
1875 @section USB Stick and DVD Installation
1877 An ISO-9660 installation image that can be written to a USB stick or
1878 burnt to a DVD can be downloaded from
1879 @indicateurl{https://alpha.gnu.org/gnu/guix/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1880 where @var{system} is one of:
1884 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1887 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1890 @c start duplication of authentication part from ``Binary Installation''
1891 Make sure to download the associated @file{.sig} file and to verify the
1892 authenticity of the image against it, along these lines:
1895 $ wget https://alpha.gnu.org/gnu/guix/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1896 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1899 If that command fails because you do not have the required public key,
1900 then run this command to import it:
1903 $ gpg --keyserver @value{KEY-SERVER} \
1904 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
1908 and rerun the @code{gpg --verify} command.
1911 This image contains the tools necessary for an installation.
1912 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1914 @unnumberedsubsec Copying to a USB Stick
1916 To copy the image to a USB stick, follow these steps:
1920 Decompress the image using the @command{xz} command:
1923 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1927 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1928 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1929 copy the image with:
1932 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1936 Access to @file{/dev/sdX} usually requires root privileges.
1939 @unnumberedsubsec Burning on a DVD
1941 To copy the image to a DVD, follow these steps:
1945 Decompress the image using the @command{xz} command:
1948 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1952 Insert a blank DVD into your machine, and determine
1953 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
1954 copy the image with:
1957 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
1960 Access to @file{/dev/srX} usually requires root privileges.
1963 @unnumberedsubsec Booting
1965 Once this is done, you should be able to reboot the system and boot from
1966 the USB stick or DVD. The latter usually requires you to get in the
1967 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
1969 @xref{Installing Guix in a VM}, if, instead, you would like to install
1970 Guix System in a virtual machine (VM).
1973 @node Preparing for Installation
1974 @section Preparing for Installation
1976 Once you have booted, you can use the guided graphical installer, which makes
1977 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
1978 if you are already familiar with GNU/Linux and if you want more control than
1979 what the graphical installer provides, you can choose the ``manual''
1980 installation process (@pxref{Manual Installation}).
1982 The graphical installer is available on TTY1. You can obtain root shells on
1983 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
1984 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
1985 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
1986 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
1987 which allows you to select text with the left mouse button and to paste it
1988 with the middle button.
1991 Installation requires access to the Internet so that any missing
1992 dependencies of your system configuration can be downloaded. See the
1993 ``Networking'' section below.
1996 @node Guided Graphical Installation
1997 @section Guided Graphical Installation
1999 The graphical installer is a text-based user interface. It will guide you,
2000 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2002 The first dialog boxes allow you to set up the system as you use it during the
2003 installation: you can choose the language, keyboard layout, and set up
2004 networking, which will be used during the installation. The image below shows
2005 the networking dialog.
2007 @image{images/installer-network,5in,, networking setup with the graphical installer}
2009 Later steps allow you to partition your hard disk, as shown in the image
2010 below, to choose whether or not to use encrypted file systems, to enter the
2011 host name and root password, and to create an additional account, among other
2014 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2016 Note that, at any time, the installer allows you to exit the current
2017 installation step and resume at a previous step, as show in the image below.
2019 @image{images/installer-resume,5in,, resuming the installation process}
2021 Once you're done, the installer produces an operating system configuration and
2022 displays it (@pxref{Using the Configuration System}). At that point you can
2023 hit ``OK'' and installation will proceed. On success, you can reboot into the
2024 new system and enjoy. @xref{After System Installation}, for what's next!
2027 @node Manual Installation
2028 @section Manual Installation
2030 This section describes how you would ``manually'' install GNU@tie{}Guix System
2031 on your machine. This option requires familiarity with GNU/Linux, with the
2032 shell, and with common administration tools. If you think this is not for
2033 you, consider using the guided graphical installer (@pxref{Guided Graphical
2036 The installation system provides root shells on TTYs 3 to 6; press
2037 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2038 many common tools needed to install the system. But it is also a full-blown
2039 Guix System, which means that you can install additional packages, should you
2040 need it, using @command{guix package} (@pxref{Invoking guix package}).
2043 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2044 * Proceeding with the Installation:: Installing.
2047 @node Keyboard Layout and Networking and Partitioning
2048 @subsection Keyboard Layout, Networking, and Partitioning
2050 Before you can install the system, you may want to adjust the keyboard layout,
2051 set up networking, and partition your target hard disk. This section will
2052 guide you through this.
2054 @subsubsection Keyboard Layout
2056 @cindex keyboard layout
2057 The installation image uses the US qwerty keyboard layout. If you want
2058 to change it, you can use the @command{loadkeys} command. For example,
2059 the following command selects the Dvorak keyboard layout:
2065 See the files under @file{/run/current-system/profile/share/keymaps} for
2066 a list of available keyboard layouts. Run @command{man loadkeys} for
2069 @subsubsection Networking
2071 Run the following command to see what your network interfaces are called:
2078 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2084 @c http://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2085 Wired interfaces have a name starting with @samp{e}; for example, the
2086 interface corresponding to the first on-board Ethernet controller is
2087 called @samp{eno1}. Wireless interfaces have a name starting with
2088 @samp{w}, like @samp{w1p2s0}.
2091 @item Wired connection
2092 To configure a wired network run the following command, substituting
2093 @var{interface} with the name of the wired interface you want to use.
2096 ifconfig @var{interface} up
2099 @item Wireless connection
2102 To configure wireless networking, you can create a configuration file
2103 for the @command{wpa_supplicant} configuration tool (its location is not
2104 important) using one of the available text editors such as
2108 nano wpa_supplicant.conf
2111 As an example, the following stanza can go to this file and will work
2112 for many wireless networks, provided you give the actual SSID and
2113 passphrase for the network you are connecting to:
2117 ssid="@var{my-ssid}"
2119 psk="the network's secret passphrase"
2123 Start the wireless service and run it in the background with the
2124 following command (substitute @var{interface} with the name of the
2125 network interface you want to use):
2128 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2131 Run @command{man wpa_supplicant} for more information.
2135 At this point, you need to acquire an IP address. On a network where IP
2136 addresses are automatically assigned @i{via} DHCP, you can run:
2139 dhclient -v @var{interface}
2142 Try to ping a server to see if networking is up and running:
2148 Setting up network access is almost always a requirement because the
2149 image does not contain all the software and tools that may be needed.
2151 @cindex installing over SSH
2152 If you want to, you can continue the installation remotely by starting
2156 herd start ssh-daemon
2159 Make sure to either set a password with @command{passwd}, or configure
2160 OpenSSH public key authentication before logging in.
2162 @subsubsection Disk Partitioning
2164 Unless this has already been done, the next step is to partition, and
2165 then format the target partition(s).
2167 The installation image includes several partitioning tools, including
2168 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2169 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2170 the partition layout you want:
2176 If your disk uses the GUID Partition Table (GPT) format and you plan to
2177 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2178 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2181 @cindex EFI, installation
2182 @cindex UEFI, installation
2183 @cindex ESP, EFI system partition
2184 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2185 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2186 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2189 parted /dev/sda set 1 esp on
2193 @vindex grub-bootloader
2194 @vindex grub-efi-bootloader
2195 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2196 @file{/sys/firmware/efi} exists in the installation image, then you should
2197 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2198 Otherwise you should use the BIOS-based GRUB, known as
2199 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2203 Once you are done partitioning the target hard disk drive, you have to
2204 create a file system on the relevant partition(s)@footnote{Currently
2205 Guix System only supports ext4 and btrfs file systems. In particular, code
2206 that reads file system UUIDs and labels only works for these file system
2207 types.}. For the ESP, if you have one and assuming it is
2208 @file{/dev/sda1}, run:
2211 mkfs.fat -F32 /dev/sda1
2214 Preferably, assign file systems a label so that you can easily and
2215 reliably refer to them in @code{file-system} declarations (@pxref{File
2216 Systems}). This is typically done using the @code{-L} option of
2217 @command{mkfs.ext4} and related commands. So, assuming the target root
2218 partition lives at @file{/dev/sda2}, a file system with the label
2219 @code{my-root} can be created with:
2222 mkfs.ext4 -L my-root /dev/sda2
2225 @cindex encrypted disk
2226 If you are instead planning to encrypt the root partition, you can use
2227 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2228 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2229 @code{man cryptsetup}} for more information.) Assuming you want to
2230 store the root partition on @file{/dev/sda2}, the command sequence would
2231 be along these lines:
2234 cryptsetup luksFormat /dev/sda2
2235 cryptsetup open --type luks /dev/sda2 my-partition
2236 mkfs.ext4 -L my-root /dev/mapper/my-partition
2239 Once that is done, mount the target file system under @file{/mnt}
2240 with a command like (again, assuming @code{my-root} is the label of the
2244 mount LABEL=my-root /mnt
2247 Also mount any other file systems you would like to use on the target
2248 system relative to this path. If you have opted for @file{/boot/efi} as an
2249 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2250 found by @code{guix system init} afterwards.
2252 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2253 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2254 sure to initialize them with @command{mkswap}. Assuming you have one
2255 swap partition on @file{/dev/sda3}, you would run:
2262 Alternatively, you may use a swap file. For example, assuming that in
2263 the new system you want to use the file @file{/swapfile} as a swap file,
2264 you would run@footnote{This example will work for many types of file
2265 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2266 btrfs), the required steps may be different. For details, see the
2267 manual pages for @command{mkswap} and @command{swapon}.}:
2270 # This is 10 GiB of swap space. Adjust "count" to change the size.
2271 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2272 # For security, make the file readable and writable only by root.
2273 chmod 600 /mnt/swapfile
2274 mkswap /mnt/swapfile
2275 swapon /mnt/swapfile
2278 Note that if you have encrypted the root partition and created a swap
2279 file in its file system as described above, then the encryption also
2280 protects the swap file, just like any other file in that file system.
2282 @node Proceeding with the Installation
2283 @subsection Proceeding with the Installation
2285 With the target partitions ready and the target root mounted on
2286 @file{/mnt}, we're ready to go. First, run:
2289 herd start cow-store /mnt
2292 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2293 during the installation phase are written to the target disk on @file{/mnt}
2294 rather than kept in memory. This is necessary because the first phase of
2295 the @command{guix system init} command (see below) entails downloads or
2296 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2298 Next, you have to edit a file and
2299 provide the declaration of the operating system to be installed. To
2300 that end, the installation system comes with three text editors. We
2301 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2302 supports syntax highlighting and parentheses matching; other editors
2303 include GNU Zile (an Emacs clone), and
2304 nvi (a clone of the original BSD @command{vi} editor).
2305 We strongly recommend storing that file on the target root file system, say,
2306 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2307 configuration file once you have rebooted into the newly-installed system.
2309 @xref{Using the Configuration System}, for an overview of the
2310 configuration file. The example configurations discussed in that
2311 section are available under @file{/etc/configuration} in the
2312 installation image. Thus, to get started with a system configuration
2313 providing a graphical display server (a ``desktop'' system), you can run
2314 something along these lines:
2318 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2319 # nano /mnt/etc/config.scm
2322 You should pay attention to what your configuration file contains, and
2327 Make sure the @code{bootloader-configuration} form refers to the target
2328 you want to install GRUB on. It should mention @code{grub-bootloader} if
2329 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2330 for newer UEFI systems. For legacy systems, the @code{target} field
2331 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2332 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2333 currently mounted and a @code{file-system} entry is specified in your
2337 Be sure that your file system labels match the value of their respective
2338 @code{device} fields in your @code{file-system} configuration, assuming
2339 your @code{file-system} configuration uses the @code{file-system-label}
2340 procedure in its @code{device} field.
2343 If there are encrypted or RAID partitions, make sure to add a
2344 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2347 Once you are done preparing the configuration file, the new system must
2348 be initialized (remember that the target root file system is mounted
2352 guix system init /mnt/etc/config.scm /mnt
2356 This copies all the necessary files and installs GRUB on
2357 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2358 more information, @pxref{Invoking guix system}. This command may trigger
2359 downloads or builds of missing packages, which can take some time.
2361 Once that command has completed---and hopefully succeeded!---you can run
2362 @command{reboot} and boot into the new system. The @code{root} password
2363 in the new system is initially empty; other users' passwords need to be
2364 initialized by running the @command{passwd} command as @code{root},
2365 unless your configuration specifies otherwise
2366 (@pxref{user-account-password, user account passwords}).
2367 @xref{After System Installation}, for what's next!
2370 @node After System Installation
2371 @section After System Installation
2373 Success, you've now booted into Guix System! From then on, you can update the
2374 system whenever you want by running, say:
2378 sudo guix system reconfigure /etc/config.scm
2382 This builds a new system generation with the latest packages and services
2383 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2384 your system includes the latest security updates (@pxref{Security Updates}).
2386 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2388 @cindex sudo vs. @command{guix pull}
2389 Note that @command{sudo guix} runs your user's @command{guix} command and
2390 @emph{not} root's, because @command{sudo} leaves @code{PATH} unchanged. To
2391 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2394 Join us on @code{#guix} on the Freenode IRC network or on
2395 @email{guix-devel@@gnu.org} to share your experience!
2398 @node Installing Guix in a VM
2399 @section Installing Guix in a Virtual Machine
2401 @cindex virtual machine, Guix System installation
2402 @cindex virtual private server (VPS)
2403 @cindex VPS (virtual private server)
2404 If you'd like to install Guix System in a virtual machine (VM) or on a
2405 virtual private server (VPS) rather than on your beloved machine, this
2408 To boot a @uref{http://qemu.org/,QEMU} VM for installing Guix System in a
2409 disk image, follow these steps:
2413 First, retrieve and decompress the Guix system installation image as
2414 described previously (@pxref{USB Stick and DVD Installation}).
2417 Create a disk image that will hold the installed system. To make a
2418 qcow2-formatted disk image, use the @command{qemu-img} command:
2421 qemu-img create -f qcow2 guixsd.img 50G
2424 The resulting file will be much smaller than 50 GB (typically less than
2425 1 MB), but it will grow as the virtualized storage device is filled up.
2428 Boot the USB installation image in an VM:
2431 qemu-system-x86_64 -m 1024 -smp 1 \
2432 -net user -net nic,model=virtio -boot menu=on \
2433 -drive file=guix-system-install-@value{VERSION}.@var{system}.iso \
2434 -drive file=guixsd.img
2437 The ordering of the drives matters.
2439 In the VM console, quickly press the @kbd{F12} key to enter the boot
2440 menu. Then press the @kbd{2} key and the @kbd{RET} key to validate your
2444 You're now root in the VM, proceed with the installation process.
2445 @xref{Preparing for Installation}, and follow the instructions.
2448 Once installation is complete, you can boot the system that's on your
2449 @file{guixsd.img} image. @xref{Running Guix in a VM}, for how to do
2452 @node Building the Installation Image
2453 @section Building the Installation Image
2455 @cindex installation image
2456 The installation image described above was built using the @command{guix
2457 system} command, specifically:
2460 guix system disk-image --file-system-type=iso9660 \
2461 gnu/system/install.scm
2464 Have a look at @file{gnu/system/install.scm} in the source tree,
2465 and see also @ref{Invoking guix system} for more information
2466 about the installation image.
2468 @section Building the Installation Image for ARM Boards
2470 Many ARM boards require a specific variant of the
2471 @uref{http://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2473 If you build a disk image and the bootloader is not available otherwise
2474 (on another boot drive etc), it's advisable to build an image that
2475 includes the bootloader, specifically:
2478 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2481 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2482 board, a list of possible boards will be printed.
2484 @c *********************************************************************
2485 @node Package Management
2486 @chapter Package Management
2489 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2490 remove software packages, without having to know about their build
2491 procedures or dependencies. Guix also goes beyond this obvious set of
2494 This chapter describes the main features of Guix, as well as the
2495 package management tools it provides. Along with the command-line
2496 interface described below (@pxref{Invoking guix package, @code{guix
2497 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2498 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2499 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2503 guix package -i emacs-guix
2507 * Features:: How Guix will make your life brighter.
2508 * Invoking guix package:: Package installation, removal, etc.
2509 * Substitutes:: Downloading pre-built binaries.
2510 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2511 * Invoking guix gc:: Running the garbage collector.
2512 * Invoking guix pull:: Fetching the latest Guix and distribution.
2513 * Channels:: Customizing the package collection.
2514 * Inferiors:: Interacting with another revision of Guix.
2515 * Invoking guix describe:: Display information about your Guix revision.
2516 * Invoking guix archive:: Exporting and importing store files.
2522 When using Guix, each package ends up in the @dfn{package store}, in its
2523 own directory---something that resembles
2524 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2526 Instead of referring to these directories, users have their own
2527 @dfn{profile}, which points to the packages that they actually want to
2528 use. These profiles are stored within each user's home directory, at
2529 @code{$HOME/.guix-profile}.
2531 For example, @code{alice} installs GCC 4.7.2. As a result,
2532 @file{/home/alice/.guix-profile/bin/gcc} points to
2533 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2534 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2535 simply continues to point to
2536 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2537 coexist on the same system without any interference.
2539 The @command{guix package} command is the central tool to manage
2540 packages (@pxref{Invoking guix package}). It operates on the per-user
2541 profiles, and can be used @emph{with normal user privileges}.
2543 @cindex transactions
2544 The command provides the obvious install, remove, and upgrade
2545 operations. Each invocation is actually a @emph{transaction}: either
2546 the specified operation succeeds, or nothing happens. Thus, if the
2547 @command{guix package} process is terminated during the transaction,
2548 or if a power outage occurs during the transaction, then the user's
2549 profile remains in its previous state, and remains usable.
2551 In addition, any package transaction may be @emph{rolled back}. So, if,
2552 for example, an upgrade installs a new version of a package that turns
2553 out to have a serious bug, users may roll back to the previous instance
2554 of their profile, which was known to work well. Similarly, the global
2555 system configuration on Guix is subject to
2556 transactional upgrades and roll-back
2557 (@pxref{Using the Configuration System}).
2559 All packages in the package store may be @emph{garbage-collected}.
2560 Guix can determine which packages are still referenced by user
2561 profiles, and remove those that are provably no longer referenced
2562 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2563 generations of their profile so that the packages they refer to can be
2566 @cindex reproducibility
2567 @cindex reproducible builds
2568 Guix takes a @dfn{purely functional} approach to package
2569 management, as described in the introduction (@pxref{Introduction}).
2570 Each @file{/gnu/store} package directory name contains a hash of all the
2571 inputs that were used to build that package---compiler, libraries, build
2572 scripts, etc. This direct correspondence allows users to make sure a
2573 given package installation matches the current state of their
2574 distribution. It also helps maximize @dfn{build reproducibility}:
2575 thanks to the isolated build environments that are used, a given build
2576 is likely to yield bit-identical files when performed on different
2577 machines (@pxref{Invoking guix-daemon, container}).
2580 This foundation allows Guix to support @dfn{transparent binary/source
2581 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2582 available from an external source---a @dfn{substitute}, Guix just
2583 downloads it and unpacks it;
2584 otherwise, it builds the package from source, locally
2585 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2586 reproducible, users do not have to trust servers that provide
2587 substitutes: they can force a local build and @emph{challenge} providers
2588 (@pxref{Invoking guix challenge}).
2590 Control over the build environment is a feature that is also useful for
2591 developers. The @command{guix environment} command allows developers of
2592 a package to quickly set up the right development environment for their
2593 package, without having to manually install the dependencies of the
2594 package into their profile (@pxref{Invoking guix environment}).
2596 @cindex replication, of software environments
2597 @cindex provenance tracking, of software artifacts
2598 All of Guix and its package definitions is version-controlled, and
2599 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2600 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2601 Guix instance on a different machine or at a later point in time, which in
2602 turn allows you to @emph{replicate complete software environments}, while
2603 retaining precise @dfn{provenance tracking} of the software.
2605 @node Invoking guix package
2606 @section Invoking @command{guix package}
2608 @cindex installing packages
2609 @cindex removing packages
2610 @cindex package installation
2611 @cindex package removal
2612 The @command{guix package} command is the tool that allows users to
2613 install, upgrade, and remove packages, as well as rolling back to
2614 previous configurations. It operates only on the user's own profile,
2615 and works with normal user privileges (@pxref{Features}). Its syntax
2619 guix package @var{options}
2621 @cindex transactions
2622 Primarily, @var{options} specifies the operations to be performed during
2623 the transaction. Upon completion, a new profile is created, but
2624 previous @dfn{generations} of the profile remain available, should the user
2627 For example, to remove @code{lua} and install @code{guile} and
2628 @code{guile-cairo} in a single transaction:
2631 guix package -r lua -i guile guile-cairo
2634 @command{guix package} also supports a @dfn{declarative approach}
2635 whereby the user specifies the exact set of packages to be available and
2636 passes it @i{via} the @option{--manifest} option
2637 (@pxref{profile-manifest, @option{--manifest}}).
2640 For each user, a symlink to the user's default profile is automatically
2641 created in @file{$HOME/.guix-profile}. This symlink always points to the
2642 current generation of the user's default profile. Thus, users can add
2643 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
2644 variable, and so on.
2645 @cindex search paths
2646 If you are not using the Guix System Distribution, consider adding the
2647 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2648 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2649 shells get all the right environment variable definitions:
2652 GUIX_PROFILE="$HOME/.guix-profile" ; \
2653 source "$HOME/.guix-profile/etc/profile"
2656 In a multi-user setup, user profiles are stored in a place registered as
2657 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2658 to (@pxref{Invoking guix gc}). That directory is normally
2659 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2660 @var{localstatedir} is the value passed to @code{configure} as
2661 @code{--localstatedir}, and @var{user} is the user name. The
2662 @file{per-user} directory is created when @command{guix-daemon} is
2663 started, and the @var{user} sub-directory is created by @command{guix
2666 The @var{options} can be among the following:
2670 @item --install=@var{package} @dots{}
2671 @itemx -i @var{package} @dots{}
2672 Install the specified @var{package}s.
2674 Each @var{package} may specify either a simple package name, such as
2675 @code{guile}, or a package name followed by an at-sign and version number,
2676 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2677 case, the newest version prefixed by @code{1.8} is selected.)
2679 If no version number is specified, the
2680 newest available version will be selected. In addition, @var{package}
2681 may contain a colon, followed by the name of one of the outputs of the
2682 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2683 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2684 name (and optionally version) are searched for among the GNU
2685 distribution modules (@pxref{Package Modules}).
2687 @cindex propagated inputs
2688 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2689 that automatically get installed along with the required package
2690 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2691 @code{package} objects}, for information about propagated inputs in
2692 package definitions).
2694 @anchor{package-cmd-propagated-inputs}
2695 An example is the GNU MPC library: its C header files refer to those of
2696 the GNU MPFR library, which in turn refer to those of the GMP library.
2697 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2698 in the profile; removing MPC also removes MPFR and GMP---unless they had
2699 also been explicitly installed by the user.
2701 Besides, packages sometimes rely on the definition of environment
2702 variables for their search paths (see explanation of
2703 @code{--search-paths} below). Any missing or possibly incorrect
2704 environment variable definitions are reported here.
2706 @item --install-from-expression=@var{exp}
2708 Install the package @var{exp} evaluates to.
2710 @var{exp} must be a Scheme expression that evaluates to a
2711 @code{<package>} object. This option is notably useful to disambiguate
2712 between same-named variants of a package, with expressions such as
2713 @code{(@@ (gnu packages base) guile-final)}.
2715 Note that this option installs the first output of the specified
2716 package, which may be insufficient when needing a specific output of a
2717 multiple-output package.
2719 @item --install-from-file=@var{file}
2720 @itemx -f @var{file}
2721 Install the package that the code within @var{file} evaluates to.
2723 As an example, @var{file} might contain a definition like this
2724 (@pxref{Defining Packages}):
2727 @verbatiminclude package-hello.scm
2730 Developers may find it useful to include such a @file{guix.scm} file
2731 in the root of their project source tree that can be used to test
2732 development snapshots and create reproducible development environments
2733 (@pxref{Invoking guix environment}).
2735 @item --remove=@var{package} @dots{}
2736 @itemx -r @var{package} @dots{}
2737 Remove the specified @var{package}s.
2739 As for @code{--install}, each @var{package} may specify a version number
2740 and/or output name in addition to the package name. For instance,
2741 @code{-r glibc:debug} would remove the @code{debug} output of
2744 @item --upgrade[=@var{regexp} @dots{}]
2745 @itemx -u [@var{regexp} @dots{}]
2746 @cindex upgrading packages
2747 Upgrade all the installed packages. If one or more @var{regexp}s are
2748 specified, upgrade only installed packages whose name matches a
2749 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2751 Note that this upgrades package to the latest version of packages found
2752 in the distribution currently installed. To update your distribution,
2753 you should regularly run @command{guix pull} (@pxref{Invoking guix
2756 @item --do-not-upgrade[=@var{regexp} @dots{}]
2757 When used together with the @code{--upgrade} option, do @emph{not}
2758 upgrade any packages whose name matches a @var{regexp}. For example, to
2759 upgrade all packages in the current profile except those containing the
2760 substring ``emacs'':
2763 $ guix package --upgrade . --do-not-upgrade emacs
2766 @item @anchor{profile-manifest}--manifest=@var{file}
2767 @itemx -m @var{file}
2768 @cindex profile declaration
2769 @cindex profile manifest
2770 Create a new generation of the profile from the manifest object
2771 returned by the Scheme code in @var{file}.
2773 This allows you to @emph{declare} the profile's contents rather than
2774 constructing it through a sequence of @code{--install} and similar
2775 commands. The advantage is that @var{file} can be put under version
2776 control, copied to different machines to reproduce the same profile, and
2779 @c FIXME: Add reference to (guix profile) documentation when available.
2780 @var{file} must return a @dfn{manifest} object, which is roughly a list
2783 @findex packages->manifest
2785 (use-package-modules guile emacs)
2790 ;; Use a specific package output.
2791 (list guile-2.0 "debug")))
2794 @findex specifications->manifest
2795 In this example we have to know which modules define the @code{emacs}
2796 and @code{guile-2.0} variables to provide the right
2797 @code{use-package-modules} line, which can be cumbersome. We can
2798 instead provide regular package specifications and let
2799 @code{specifications->manifest} look up the corresponding package
2803 (specifications->manifest
2804 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2808 @cindex rolling back
2809 @cindex undoing transactions
2810 @cindex transactions, undoing
2811 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2812 the last transaction.
2814 When combined with options such as @code{--install}, roll back occurs
2815 before any other actions.
2817 When rolling back from the first generation that actually contains
2818 installed packages, the profile is made to point to the @dfn{zeroth
2819 generation}, which contains no files apart from its own metadata.
2821 After having rolled back, installing, removing, or upgrading packages
2822 overwrites previous future generations. Thus, the history of the
2823 generations in a profile is always linear.
2825 @item --switch-generation=@var{pattern}
2826 @itemx -S @var{pattern}
2828 Switch to a particular generation defined by @var{pattern}.
2830 @var{pattern} may be either a generation number or a number prefixed
2831 with ``+'' or ``-''. The latter means: move forward/backward by a
2832 specified number of generations. For example, if you want to return to
2833 the latest generation after @code{--roll-back}, use
2834 @code{--switch-generation=+1}.
2836 The difference between @code{--roll-back} and
2837 @code{--switch-generation=-1} is that @code{--switch-generation} will
2838 not make a zeroth generation, so if a specified generation does not
2839 exist, the current generation will not be changed.
2841 @item --search-paths[=@var{kind}]
2842 @cindex search paths
2843 Report environment variable definitions, in Bash syntax, that may be
2844 needed in order to use the set of installed packages. These environment
2845 variables are used to specify @dfn{search paths} for files used by some
2846 of the installed packages.
2848 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2849 environment variables to be defined so it can look for headers and
2850 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2851 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2852 library are installed in the profile, then @code{--search-paths} will
2853 suggest setting these variables to @code{@var{profile}/include} and
2854 @code{@var{profile}/lib}, respectively.
2856 The typical use case is to define these environment variables in the
2860 $ eval `guix package --search-paths`
2863 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2864 meaning that the returned environment variable definitions will either
2865 be exact settings, or prefixes or suffixes of the current value of these
2866 variables. When omitted, @var{kind} defaults to @code{exact}.
2868 This option can also be used to compute the @emph{combined} search paths
2869 of several profiles. Consider this example:
2872 $ guix package -p foo -i guile
2873 $ guix package -p bar -i guile-json
2874 $ guix package -p foo -p bar --search-paths
2877 The last command above reports about the @code{GUILE_LOAD_PATH}
2878 variable, even though, taken individually, neither @file{foo} nor
2879 @file{bar} would lead to that recommendation.
2882 @item --profile=@var{profile}
2883 @itemx -p @var{profile}
2884 Use @var{profile} instead of the user's default profile.
2886 @cindex collisions, in a profile
2887 @cindex colliding packages in profiles
2888 @cindex profile collisions
2889 @item --allow-collisions
2890 Allow colliding packages in the new profile. Use at your own risk!
2892 By default, @command{guix package} reports as an error @dfn{collisions}
2893 in the profile. Collisions happen when two or more different versions
2894 or variants of a given package end up in the profile.
2897 Use the bootstrap Guile to build the profile. This option is only
2898 useful to distribution developers.
2902 In addition to these actions, @command{guix package} supports the
2903 following options to query the current state of a profile, or the
2904 availability of packages:
2908 @item --search=@var{regexp}
2909 @itemx -s @var{regexp}
2910 @cindex searching for packages
2911 List the available packages whose name, synopsis, or description matches
2912 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
2913 Print all the metadata of matching packages in
2914 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
2915 GNU recutils manual}).
2917 This allows specific fields to be extracted using the @command{recsel}
2918 command, for instance:
2921 $ guix package -s malloc | recsel -p name,version,relevance
2935 Similarly, to show the name of all the packages available under the
2936 terms of the GNU@tie{}LGPL version 3:
2939 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
2946 It is also possible to refine search results using several @code{-s}
2947 flags. For example, the following command returns a list of board
2951 $ guix package -s '\<board\>' -s game | recsel -p name
2956 If we were to omit @code{-s game}, we would also get software packages
2957 that deal with printed circuit boards; removing the angle brackets
2958 around @code{board} would further add packages that have to do with
2961 And now for a more elaborate example. The following command searches
2962 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
2963 libraries, and prints the name and synopsis of the matching packages:
2966 $ guix package -s crypto -s library | \
2967 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
2971 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
2972 information on @dfn{selection expressions} for @code{recsel -e}.
2974 @item --show=@var{package}
2975 Show details about @var{package}, taken from the list of available packages, in
2976 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
2980 $ guix package --show=python | recsel -p name,version
2988 You may also specify the full name of a package to only get details about a
2989 specific version of it:
2991 $ guix package --show=python@@3.4 | recsel -p name,version
2998 @item --list-installed[=@var{regexp}]
2999 @itemx -I [@var{regexp}]
3000 List the currently installed packages in the specified profile, with the
3001 most recently installed packages shown last. When @var{regexp} is
3002 specified, list only installed packages whose name matches @var{regexp}.
3004 For each installed package, print the following items, separated by
3005 tabs: the package name, its version string, the part of the package that
3006 is installed (for instance, @code{out} for the default output,
3007 @code{include} for its headers, etc.), and the path of this package in
3010 @item --list-available[=@var{regexp}]
3011 @itemx -A [@var{regexp}]
3012 List packages currently available in the distribution for this system
3013 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3014 installed packages whose name matches @var{regexp}.
3016 For each package, print the following items separated by tabs: its name,
3017 its version string, the parts of the package (@pxref{Packages with
3018 Multiple Outputs}), and the source location of its definition.
3020 @item --list-generations[=@var{pattern}]
3021 @itemx -l [@var{pattern}]
3023 Return a list of generations along with their creation dates; for each
3024 generation, show the installed packages, with the most recently
3025 installed packages shown last. Note that the zeroth generation is never
3028 For each installed package, print the following items, separated by
3029 tabs: the name of a package, its version string, the part of the package
3030 that is installed (@pxref{Packages with Multiple Outputs}), and the
3031 location of this package in the store.
3033 When @var{pattern} is used, the command returns only matching
3034 generations. Valid patterns include:
3037 @item @emph{Integers and comma-separated integers}. Both patterns denote
3038 generation numbers. For instance, @code{--list-generations=1} returns
3041 And @code{--list-generations=1,8,2} outputs three generations in the
3042 specified order. Neither spaces nor trailing commas are allowed.
3044 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
3045 specified generations and everything in between. Note that the start of
3046 a range must be smaller than its end.
3048 It is also possible to omit the endpoint. For example,
3049 @code{--list-generations=2..}, returns all generations starting from the
3052 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3053 or months by passing an integer along with the first letter of the
3054 duration. For example, @code{--list-generations=20d} lists generations
3055 that are up to 20 days old.
3058 @item --delete-generations[=@var{pattern}]
3059 @itemx -d [@var{pattern}]
3060 When @var{pattern} is omitted, delete all generations except the current
3063 This command accepts the same patterns as @option{--list-generations}.
3064 When @var{pattern} is specified, delete the matching generations. When
3065 @var{pattern} specifies a duration, generations @emph{older} than the
3066 specified duration match. For instance, @code{--delete-generations=1m}
3067 deletes generations that are more than one month old.
3069 If the current generation matches, it is @emph{not} deleted. Also, the
3070 zeroth generation is never deleted.
3072 Note that deleting generations prevents rolling back to them.
3073 Consequently, this command must be used with care.
3077 Finally, since @command{guix package} may actually start build
3078 processes, it supports all the common build options (@pxref{Common Build
3079 Options}). It also supports package transformation options, such as
3080 @option{--with-source} (@pxref{Package Transformation Options}).
3081 However, note that package transformations are lost when upgrading; to
3082 preserve transformations across upgrades, you should define your own
3083 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
3084 (@pxref{Defining Packages}).
3087 @section Substitutes
3090 @cindex pre-built binaries
3091 Guix supports transparent source/binary deployment, which means that it
3092 can either build things locally, or download pre-built items from a
3093 server, or both. We call these pre-built items @dfn{substitutes}---they
3094 are substitutes for local build results. In many cases, downloading a
3095 substitute is much faster than building things locally.
3097 Substitutes can be anything resulting from a derivation build
3098 (@pxref{Derivations}). Of course, in the common case, they are
3099 pre-built package binaries, but source tarballs, for instance, which
3100 also result from derivation builds, can be available as substitutes.
3103 * Official Substitute Server:: One particular source of substitutes.
3104 * Substitute Server Authorization:: How to enable or disable substitutes.
3105 * Substitute Authentication:: How Guix verifies substitutes.
3106 * Proxy Settings:: How to get substitutes via proxy.
3107 * Substitution Failure:: What happens when substitution fails.
3108 * On Trusting Binaries:: How can you trust that binary blob?
3111 @node Official Substitute Server
3112 @subsection Official Substitute Server
3116 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3117 that builds packages from Guix continuously for some
3118 architectures, and makes them available as substitutes. This is the
3119 default source of substitutes; it can be overridden by passing the
3120 @option{--substitute-urls} option either to @command{guix-daemon}
3121 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3122 or to client tools such as @command{guix package}
3123 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3126 Substitute URLs can be either HTTP or HTTPS.
3127 HTTPS is recommended because communications are encrypted; conversely,
3128 using HTTP makes all communications visible to an eavesdropper, who
3129 could use the information gathered to determine, for instance, whether
3130 your system has unpatched security vulnerabilities.
3132 Substitutes from the official build farm are enabled by default when
3133 using the Guix System Distribution (@pxref{GNU Distribution}). However,
3134 they are disabled by default when using Guix on a foreign distribution,
3135 unless you have explicitly enabled them via one of the recommended
3136 installation steps (@pxref{Installation}). The following paragraphs
3137 describe how to enable or disable substitutes for the official build
3138 farm; the same procedure can also be used to enable substitutes for any
3139 other substitute server.
3141 @node Substitute Server Authorization
3142 @subsection Substitute Server Authorization
3145 @cindex substitutes, authorization thereof
3146 @cindex access control list (ACL), for substitutes
3147 @cindex ACL (access control list), for substitutes
3148 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3150 must add its public key to the access control list (ACL) of archive
3151 imports, using the @command{guix archive} command (@pxref{Invoking guix
3152 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3153 be compromised and to serve genuine substitutes.
3155 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3156 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3157 the installation prefix of Guix. If you installed Guix from source,
3158 make sure you checked the GPG signature of
3159 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3160 Then, you can run something like this:
3163 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3167 Similarly, the @file{hydra.gnu.org.pub} file contains the public key
3168 of an independent build farm also run by the project, reachable at
3169 @indicateurl{https://mirror.hydra.gnu.org}.
3172 Once this is in place, the output of a command like @code{guix build}
3173 should change from something like:
3176 $ guix build emacs --dry-run
3177 The following derivations would be built:
3178 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3179 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3180 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3181 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3189 $ guix build emacs --dry-run
3190 112.3 MB would be downloaded:
3191 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3192 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3193 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3194 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3199 This indicates that substitutes from @code{@value{SUBSTITUTE-SERVER}} are usable and
3200 will be downloaded, when possible, for future builds.
3202 @cindex substitutes, how to disable
3203 The substitute mechanism can be disabled globally by running
3204 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
3205 guix-daemon}). It can also be disabled temporarily by passing the
3206 @code{--no-substitutes} option to @command{guix package}, @command{guix
3207 build}, and other command-line tools.
3209 @node Substitute Authentication
3210 @subsection Substitute Authentication
3212 @cindex digital signatures
3213 Guix detects and raises an error when attempting to use a substitute
3214 that has been tampered with. Likewise, it ignores substitutes that are
3215 not signed, or that are not signed by one of the keys listed in the ACL.
3217 There is one exception though: if an unauthorized server provides
3218 substitutes that are @emph{bit-for-bit identical} to those provided by
3219 an authorized server, then the unauthorized server becomes eligible for
3220 downloads. For example, assume we have chosen two substitute servers
3224 --substitute-urls="https://a.example.org https://b.example.org"
3228 @cindex reproducible builds
3229 If the ACL contains only the key for @code{b.example.org}, and if
3230 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
3231 then Guix will download substitutes from @code{a.example.org} because it
3232 comes first in the list and can be considered a mirror of
3233 @code{b.example.org}. In practice, independent build machines usually
3234 produce the same binaries, thanks to bit-reproducible builds (see
3237 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3238 (in other words, the server is not authenticated), contrary to what
3239 HTTPS clients such as Web browsers usually do. This is because Guix
3240 authenticates substitute information itself, as explained above, which
3241 is what we care about (whereas X.509 certificates are about
3242 authenticating bindings between domain names and public keys.)
3244 @node Proxy Settings
3245 @subsection Proxy Settings
3248 Substitutes are downloaded over HTTP or HTTPS.
3249 The @code{http_proxy} environment
3250 variable can be set in the environment of @command{guix-daemon} and is
3251 honored for downloads of substitutes. Note that the value of
3252 @code{http_proxy} in the environment where @command{guix build},
3253 @command{guix package}, and other client commands are run has
3254 @emph{absolutely no effect}.
3256 @node Substitution Failure
3257 @subsection Substitution Failure
3259 Even when a substitute for a derivation is available, sometimes the
3260 substitution attempt will fail. This can happen for a variety of
3261 reasons: the substitute server might be offline, the substitute may
3262 recently have been deleted, the connection might have been interrupted,
3265 When substitutes are enabled and a substitute for a derivation is
3266 available, but the substitution attempt fails, Guix will attempt to
3267 build the derivation locally depending on whether or not
3268 @code{--fallback} was given (@pxref{fallback-option,, common build
3269 option @code{--fallback}}). Specifically, if @code{--fallback} was
3270 omitted, then no local build will be performed, and the derivation is
3271 considered to have failed. However, if @code{--fallback} was given,
3272 then Guix will attempt to build the derivation locally, and the success
3273 or failure of the derivation depends on the success or failure of the
3274 local build. Note that when substitutes are disabled or no substitute
3275 is available for the derivation in question, a local build will
3276 @emph{always} be performed, regardless of whether or not
3277 @code{--fallback} was given.
3279 To get an idea of how many substitutes are available right now, you can
3280 try running the @command{guix weather} command (@pxref{Invoking guix
3281 weather}). This command provides statistics on the substitutes provided
3284 @node On Trusting Binaries
3285 @subsection On Trusting Binaries
3287 @cindex trust, of pre-built binaries
3288 Today, each individual's control over their own computing is at the
3289 mercy of institutions, corporations, and groups with enough power and
3290 determination to subvert the computing infrastructure and exploit its
3291 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3292 convenient, we encourage users to also build on their own, or even run
3293 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3294 interesting target. One way to help is by publishing the software you
3295 build using @command{guix publish} so that others have one more choice
3296 of server to download substitutes from (@pxref{Invoking guix publish}).
3298 Guix has the foundations to maximize build reproducibility
3299 (@pxref{Features}). In most cases, independent builds of a given
3300 package or derivation should yield bit-identical results. Thus, through
3301 a diverse set of independent package builds, we can strengthen the
3302 integrity of our systems. The @command{guix challenge} command aims to
3303 help users assess substitute servers, and to assist developers in
3304 finding out about non-deterministic package builds (@pxref{Invoking guix
3305 challenge}). Similarly, the @option{--check} option of @command{guix
3306 build} allows users to check whether previously-installed substitutes
3307 are genuine by rebuilding them locally (@pxref{build-check,
3308 @command{guix build --check}}).
3310 In the future, we want Guix to have support to publish and retrieve
3311 binaries to/from other users, in a peer-to-peer fashion. If you would
3312 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3314 @node Packages with Multiple Outputs
3315 @section Packages with Multiple Outputs
3317 @cindex multiple-output packages
3318 @cindex package outputs
3321 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3322 source package leads to exactly one directory in the store. When running
3323 @command{guix package -i glibc}, one installs the default output of the
3324 GNU libc package; the default output is called @code{out}, but its name
3325 can be omitted as shown in this command. In this particular case, the
3326 default output of @code{glibc} contains all the C header files, shared
3327 libraries, static libraries, Info documentation, and other supporting
3330 Sometimes it is more appropriate to separate the various types of files
3331 produced from a single source package into separate outputs. For
3332 instance, the GLib C library (used by GTK+ and related packages)
3333 installs more than 20 MiB of reference documentation as HTML pages.
3334 To save space for users who do not need it, the documentation goes to a
3335 separate output, called @code{doc}. To install the main GLib output,
3336 which contains everything but the documentation, one would run:
3339 guix package -i glib
3342 @cindex documentation
3343 The command to install its documentation is:
3346 guix package -i glib:doc
3349 Some packages install programs with different ``dependency footprints''.
3350 For instance, the WordNet package installs both command-line tools and
3351 graphical user interfaces (GUIs). The former depend solely on the C
3352 library, whereas the latter depend on Tcl/Tk and the underlying X
3353 libraries. In this case, we leave the command-line tools in the default
3354 output, whereas the GUIs are in a separate output. This allows users
3355 who do not need the GUIs to save space. The @command{guix size} command
3356 can help find out about such situations (@pxref{Invoking guix size}).
3357 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3359 There are several such multiple-output packages in the GNU distribution.
3360 Other conventional output names include @code{lib} for libraries and
3361 possibly header files, @code{bin} for stand-alone programs, and
3362 @code{debug} for debugging information (@pxref{Installing Debugging
3363 Files}). The outputs of a packages are listed in the third column of
3364 the output of @command{guix package --list-available} (@pxref{Invoking
3368 @node Invoking guix gc
3369 @section Invoking @command{guix gc}
3371 @cindex garbage collector
3373 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3374 The @command{guix gc} command allows users to explicitly run the garbage
3375 collector to reclaim space from the @file{/gnu/store} directory. It is
3376 the @emph{only} way to remove files from @file{/gnu/store}---removing
3377 files or directories manually may break it beyond repair!
3380 @cindex garbage collector roots
3381 The garbage collector has a set of known @dfn{roots}: any file under
3382 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3383 cannot be deleted; any other file is considered @dfn{dead} and may be
3384 deleted. The set of garbage collector roots (``GC roots'' for short)
3385 includes default user profiles; by default, the symlinks under
3386 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3387 added with @command{guix build --root}, for example (@pxref{Invoking
3388 guix build}). The @command{guix gc --list-roots} command lists them.
3390 Prior to running @code{guix gc --collect-garbage} to make space, it is
3391 often useful to remove old generations from user profiles; that way, old
3392 package builds referenced by those generations can be reclaimed. This
3393 is achieved by running @code{guix package --delete-generations}
3394 (@pxref{Invoking guix package}).
3396 Our recommendation is to run a garbage collection periodically, or when
3397 you are short on disk space. For instance, to guarantee that at least
3398 5@tie{}GB are available on your disk, simply run:
3404 It is perfectly safe to run as a non-interactive periodic job
3405 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3406 Running @command{guix gc} with no arguments will collect as
3407 much garbage as it can, but that is often inconvenient: you may find
3408 yourself having to rebuild or re-download software that is ``dead'' from
3409 the GC viewpoint but that is necessary to build other pieces of
3410 software---e.g., the compiler tool chain.
3412 The @command{guix gc} command has three modes of operation: it can be
3413 used to garbage-collect any dead files (the default), to delete specific
3414 files (the @code{--delete} option), to print garbage-collector
3415 information, or for more advanced queries. The garbage collection
3416 options are as follows:
3419 @item --collect-garbage[=@var{min}]
3420 @itemx -C [@var{min}]
3421 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3422 sub-directories. This is the default operation when no option is
3425 When @var{min} is given, stop once @var{min} bytes have been collected.
3426 @var{min} may be a number of bytes, or it may include a unit as a
3427 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3428 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3430 When @var{min} is omitted, collect all the garbage.
3432 @item --free-space=@var{free}
3433 @itemx -F @var{free}
3434 Collect garbage until @var{free} space is available under
3435 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3436 as @code{500MiB}, as described above.
3438 When @var{free} or more is already available in @file{/gnu/store}, do
3439 nothing and exit immediately.
3441 @item --delete-generations[=@var{duration}]
3442 @itemx -d [@var{duration}]
3443 Before starting the garbage collection process, delete all the generations
3444 older than @var{duration}, for all the user profiles; when run as root, this
3445 applies to all the profiles @emph{of all the users}.
3447 For example, this command deletes all the generations of all your profiles
3448 that are older than 2 months (except generations that are current), and then
3449 proceeds to free space until at least 10 GiB are available:
3452 guix gc -d 2m -F 10G
3457 Attempt to delete all the store files and directories specified as
3458 arguments. This fails if some of the files are not in the store, or if
3459 they are still live.
3461 @item --list-failures
3462 List store items corresponding to cached build failures.
3464 This prints nothing unless the daemon was started with
3465 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3466 @option{--cache-failures}}).
3469 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3472 @item --clear-failures
3473 Remove the specified store items from the failed-build cache.
3475 Again, this option only makes sense when the daemon is started with
3476 @option{--cache-failures}. Otherwise, it does nothing.
3479 Show the list of dead files and directories still present in the
3480 store---i.e., files and directories no longer reachable from any root.
3483 Show the list of live store files and directories.
3487 In addition, the references among existing store files can be queried:
3493 @cindex package dependencies
3494 List the references (respectively, the referrers) of store files given
3500 List the requisites of the store files passed as arguments. Requisites
3501 include the store files themselves, their references, and the references
3502 of these, recursively. In other words, the returned list is the
3503 @dfn{transitive closure} of the store files.
3505 @xref{Invoking guix size}, for a tool to profile the size of the closure
3506 of an element. @xref{Invoking guix graph}, for a tool to visualize
3507 the graph of references.
3511 Return the derivation(s) leading to the given store items
3512 (@pxref{Derivations}).
3514 For example, this command:
3517 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3521 returns the @file{.drv} file(s) leading to the @code{emacs} package
3522 installed in your profile.
3524 Note that there may be zero matching @file{.drv} files, for instance
3525 because these files have been garbage-collected. There can also be more
3526 than one matching @file{.drv} due to fixed-output derivations.
3529 Lastly, the following options allow you to check the integrity of the
3530 store and to control disk usage.
3534 @item --verify[=@var{options}]
3535 @cindex integrity, of the store
3536 @cindex integrity checking
3537 Verify the integrity of the store.
3539 By default, make sure that all the store items marked as valid in the
3540 database of the daemon actually exist in @file{/gnu/store}.
3542 When provided, @var{options} must be a comma-separated list containing one
3543 or more of @code{contents} and @code{repair}.
3545 When passing @option{--verify=contents}, the daemon computes the
3546 content hash of each store item and compares it against its hash in the
3547 database. Hash mismatches are reported as data corruptions. Because it
3548 traverses @emph{all the files in the store}, this command can take a
3549 long time, especially on systems with a slow disk drive.
3551 @cindex repairing the store
3552 @cindex corruption, recovering from
3553 Using @option{--verify=repair} or @option{--verify=contents,repair}
3554 causes the daemon to try to repair corrupt store items by fetching
3555 substitutes for them (@pxref{Substitutes}). Because repairing is not
3556 atomic, and thus potentially dangerous, it is available only to the
3557 system administrator. A lightweight alternative, when you know exactly
3558 which items in the store are corrupt, is @command{guix build --repair}
3559 (@pxref{Invoking guix build}).
3562 @cindex deduplication
3563 Optimize the store by hard-linking identical files---this is
3564 @dfn{deduplication}.
3566 The daemon performs deduplication after each successful build or archive
3567 import, unless it was started with @code{--disable-deduplication}
3568 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
3569 this option is primarily useful when the daemon was running with
3570 @code{--disable-deduplication}.
3574 @node Invoking guix pull
3575 @section Invoking @command{guix pull}
3577 @cindex upgrading Guix
3578 @cindex updating Guix
3579 @cindex @command{guix pull}
3581 Packages are installed or upgraded to the latest version available in
3582 the distribution currently available on your local machine. To update
3583 that distribution, along with the Guix tools, you must run @command{guix
3584 pull}: the command downloads the latest Guix source code and package
3585 descriptions, and deploys it. Source code is downloaded from a
3586 @uref{https://git-scm.com, Git} repository, by default the official
3587 GNU@tie{}Guix repository, though this can be customized.
3589 On completion, @command{guix package} will use packages and package
3590 versions from this just-retrieved copy of Guix. Not only that, but all
3591 the Guix commands and Scheme modules will also be taken from that latest
3592 version. New @command{guix} sub-commands added by the update also
3595 Any user can update their Guix copy using @command{guix pull}, and the
3596 effect is limited to the user who run @command{guix pull}. For
3597 instance, when user @code{root} runs @command{guix pull}, this has no
3598 effect on the version of Guix that user @code{alice} sees, and vice
3601 The result of running @command{guix pull} is a @dfn{profile} available
3602 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3603 make sure to add it to the beginning of your search path so that you use
3604 the latest version, and similarly for the Info manual
3605 (@pxref{Documentation}):
3608 export PATH="$HOME/.config/guix/current/bin:$PATH"
3609 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3612 The @code{--list-generations} or @code{-l} option lists past generations
3613 produced by @command{guix pull}, along with details about their provenance:
3617 Generation 1 Jun 10 2018 00:18:18
3619 repository URL: https://git.savannah.gnu.org/git/guix.git
3620 branch: origin/master
3621 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3623 Generation 2 Jun 11 2018 11:02:49
3625 repository URL: https://git.savannah.gnu.org/git/guix.git
3626 branch: origin/master
3627 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3628 2 new packages: keepalived, libnfnetlink
3629 6 packages upgraded: emacs-nix-mode@@2.0.4,
3630 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3631 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3633 Generation 3 Jun 13 2018 23:31:07 (current)
3635 repository URL: https://git.savannah.gnu.org/git/guix.git
3636 branch: origin/master
3637 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3638 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3639 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3642 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3643 describe the current status of Guix.
3645 This @code{~/.config/guix/current} profile works like any other profile
3646 created by @command{guix package} (@pxref{Invoking guix package}). That
3647 is, you can list generations, roll back to the previous
3648 generation---i.e., the previous Guix---and so on:
3651 $ guix package -p ~/.config/guix/current --roll-back
3652 switched from generation 3 to 2
3653 $ guix package -p ~/.config/guix/current --delete-generations=1
3654 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3657 The @command{guix pull} command is usually invoked with no arguments,
3658 but it supports the following options:
3661 @item --url=@var{url}
3662 @itemx --commit=@var{commit}
3663 @itemx --branch=@var{branch}
3664 Download code from the specified @var{url}, at the given @var{commit} (a valid
3665 Git commit ID represented as a hexadecimal string), or @var{branch}.
3667 @cindex @file{channels.scm}, configuration file
3668 @cindex configuration file for channels
3669 These options are provided for convenience, but you can also specify your
3670 configuration in the @file{~/.config/guix/channels.scm} file or using the
3671 @option{--channels} option (see below).
3673 @item --channels=@var{file}
3674 @itemx -C @var{file}
3675 Read the list of channels from @var{file} instead of
3676 @file{~/.config/guix/channels.scm}. @var{file} must contain Scheme code that
3677 evaluates to a list of channel objects. @xref{Channels}, for more
3680 @item --list-generations[=@var{pattern}]
3681 @itemx -l [@var{pattern}]
3682 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3683 is provided, the subset of generations that match @var{pattern}.
3684 The syntax of @var{pattern} is the same as with @code{guix package
3685 --list-generations} (@pxref{Invoking guix package}).
3687 @xref{Invoking guix describe}, for a way to display information about the
3688 current generation only.
3690 @item --profile=@var{profile}
3691 @itemx -p @var{profile}
3692 Use @var{profile} instead of @file{~/.config/guix/current}.
3696 Show which channel commit(s) would be used and what would be built or
3697 substituted but do not actually do it.
3699 @item --system=@var{system}
3700 @itemx -s @var{system}
3701 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3702 the system type of the build host.
3705 Produce verbose output, writing build logs to the standard error output.
3708 Use the bootstrap Guile to build the latest Guix. This option is only
3709 useful to Guix developers.
3712 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3713 repository and branch to pull from, as well as @emph{additional} repositories
3714 containing package modules that should be deployed. @xref{Channels}, for more
3717 In addition, @command{guix pull} supports all the common build options
3718 (@pxref{Common Build Options}).
3724 @cindex @file{channels.scm}, configuration file
3725 @cindex configuration file for channels
3726 @cindex @command{guix pull}, configuration file
3727 @cindex configuration of @command{guix pull}
3728 Guix and its package collection are updated by running @command{guix pull}
3729 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3730 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3731 customized by defining @dfn{channels} in the
3732 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3733 of a Git repository to be deployed, and @command{guix pull} can be instructed
3734 to pull from one or more channels. In other words, channels can be used to
3735 @emph{customize} and to @emph{extend} Guix, as we will see below.
3737 @subsection Using a Custom Guix Channel
3739 The channel called @code{guix} specifies where Guix itself---its command-line
3740 tools as well as its package collection---should be downloaded. For instance,
3741 suppose you want to update from your own copy of the Guix repository at
3742 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3743 write in @code{~/.config/guix/channels.scm} this specification:
3746 ;; Tell 'guix pull' to use my own repo.
3749 (url "https://example.org/my-guix.git")
3750 (branch "super-hacks")))
3754 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3755 branch of the repository at @code{example.org}.
3757 @subsection Specifying Additional Channels
3759 @cindex extending the package collection (channels)
3760 @cindex personal packages (channels)
3761 @cindex channels, for personal packages
3762 You can also specify @emph{additional channels} to pull from. Let's say you
3763 have a bunch of custom package variants or personal packages that you think
3764 would make little sense to contribute to the Guix project, but would like to
3765 have these packages transparently available to you at the command line. You
3766 would first write modules containing those package definitions (@pxref{Package
3767 Modules}), maintain them in a Git repository, and then you and anyone else can
3768 use it as an additional channel to get packages from. Neat, no?
3770 @c What follows stems from discussions at
3771 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3772 @c earlier discussions on guix-devel@gnu.org.
3774 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3775 publish your personal channel to the world, we would like to share a few words
3780 Before publishing a channel, please consider contributing your package
3781 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3782 to free software of all sorts, and packages in Guix proper are readily
3783 available to all Guix users and benefit from the project's quality assurance
3787 When you maintain package definitions outside Guix, we, Guix developers,
3788 consider that @emph{the compatibility burden is on you}. Remember that
3789 package modules and package definitions are just Scheme code that uses various
3790 programming interfaces (APIs). We want to remain free to change these APIs to
3791 keep improving Guix, possibly in ways that break your channel. We never
3792 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3796 Corollary: if you're using an external channel and that channel breaks, please
3797 @emph{report the issue to the channel authors}, not to the Guix project.
3800 You've been warned! Having said this, we believe external channels are a
3801 practical way to exert your freedom to augment Guix' package collection and to
3802 share your improvements, which are basic tenets of
3803 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3804 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3807 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
3808 @command{guix pull} to pull from it @emph{in addition} to the default Guix
3811 @vindex %default-channels
3813 ;; Add my personal packages to those Guix provides.
3815 (name 'my-personal-packages)
3816 (url "https://example.org/personal-packages.git"))
3821 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3822 add a channel the list of channels that the variable @code{%default-channels}
3823 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3824 Manual}). With this file in place, @command{guix pull} builds not only Guix
3825 but also the package modules from your own repository. The result in
3826 @file{~/.config/guix/current} is the union of Guix with your own package
3830 $ guix pull --list-generations
3832 Generation 19 Aug 27 2018 16:20:48
3834 repository URL: https://git.savannah.gnu.org/git/guix.git
3836 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
3837 my-personal-packages dd3df5e
3838 repository URL: https://example.org/personal-packages.git
3840 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
3841 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
3842 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
3846 The output of @command{guix pull} above shows that Generation@tie{}19 includes
3847 both Guix and packages from the @code{my-personal-packages} channel. Among
3848 the new and upgraded packages that are listed, some like @code{my-gimp} and
3849 @code{my-emacs-with-cool-features} might come from
3850 @code{my-personal-packages}, while others come from the Guix default channel.
3852 To create a channel, create a Git repository containing your own package
3853 modules and make it available. The repository can contain anything, but a
3854 useful channel will contain Guile modules that export packages. Once you
3855 start using a channel, Guix will behave as if the root directory of that
3856 channel's Git repository has been added to the Guile load path (@pxref{Load
3857 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
3858 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
3859 module, then the module will be available under the name @code{(my-packages
3860 my-tools)}, and you will be able to use it like any other module
3861 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
3863 @cindex dependencies, channels
3864 @cindex meta-data, channels
3865 @subsection Declaring Channel Dependencies
3867 Channel authors may decide to augment a package collection provided by other
3868 channels. They can declare their channel to be dependent on other channels in
3869 a meta-data file @file{.guix-channel}, which is to be placed in the root of
3870 the channel repository.
3872 The meta-data file should contain a simple S-expression like this:
3879 (name some-collection)
3880 (url "https://example.org/first-collection.git"))
3882 (name some-other-collection)
3883 (url "https://example.org/second-collection.git")
3884 (branch "testing"))))
3887 In the above example this channel is declared to depend on two other channels,
3888 which will both be fetched automatically. The modules provided by the channel
3889 will be compiled in an environment where the modules of all these declared
3890 channels are available.
3892 For the sake of reliability and maintainability, you should avoid dependencies
3893 on channels that you don't control, and you should aim to keep the number of
3894 dependencies to a minimum.
3896 @subsection Replicating Guix
3898 @cindex pinning, channels
3899 @cindex replicating Guix
3900 @cindex reproducibility, of Guix
3901 The @command{guix pull --list-generations} output above shows precisely which
3902 commits were used to build this instance of Guix. We can thus replicate it,
3903 say, on another machine, by providing a channel specification in
3904 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
3907 ;; Deploy specific commits of my channels of interest.
3910 (url "https://git.savannah.gnu.org/git/guix.git")
3911 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
3913 (name 'my-personal-packages)
3914 (url "https://example.org/personal-packages.git")
3915 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
3918 The @command{guix describe --format=channels} command can even generate this
3919 list of channels directly (@pxref{Invoking guix describe}).
3921 At this point the two machines run the @emph{exact same Guix}, with access to
3922 the @emph{exact same packages}. The output of @command{guix build gimp} on
3923 one machine will be exactly the same, bit for bit, as the output of the same
3924 command on the other machine. It also means both machines have access to all
3925 the source code of Guix and, transitively, to all the source code of every
3928 This gives you super powers, allowing you to track the provenance of binary
3929 artifacts with very fine grain, and to reproduce software environments at
3930 will---some sort of ``meta reproducibility'' capabilities, if you will.
3931 @xref{Inferiors}, for another way to take advantage of these super powers.
3936 @c TODO: Remove this once we're more confident about API stability.
3938 The functionality described here is a ``technology preview'' as of version
3939 @value{VERSION}. As such, the interface is subject to change.
3943 @cindex composition of Guix revisions
3944 Sometimes you might need to mix packages from the revision of Guix you're
3945 currently running with packages available in a different revision of Guix.
3946 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
3947 revisions in arbitrary ways.
3949 @cindex inferior packages
3950 Technically, an ``inferior'' is essentially a separate Guix process connected
3951 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
3952 @code{(guix inferior)} module allows you to create inferiors and to
3953 communicate with them. It also provides a high-level interface to browse and
3954 manipulate the packages that an inferior provides---@dfn{inferior packages}.
3956 When combined with channels (@pxref{Channels}), inferiors provide a simple way
3957 to interact with a separate revision of Guix. For example, let's assume you
3958 want to install in your profile the current @code{guile} package, along with
3959 the @code{guile-json} as it existed in an older revision of Guix---perhaps
3960 because the newer @code{guile-json} has an incompatible API and you want to
3961 run your code against the old API@. To do that, you could write a manifest for
3962 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
3963 manifest, you would create an inferior for that old Guix revision you care
3964 about, and you would look up the @code{guile-json} package in the inferior:
3967 (use-modules (guix inferior) (guix channels)
3968 (srfi srfi-1)) ;for 'first'
3971 ;; This is the old revision from which we want to
3972 ;; extract guile-json.
3975 (url "https://git.savannah.gnu.org/git/guix.git")
3977 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
3980 ;; An inferior representing the above revision.
3981 (inferior-for-channels channels))
3983 ;; Now create a manifest with the current "guile" package
3984 ;; and the old "guile-json" package.
3986 (list (first (lookup-inferior-packages inferior "guile-json"))
3987 (specification->package "guile")))
3990 On its first run, @command{guix package --manifest} might have to build the
3991 channel you specified before it can create the inferior; subsequent runs will
3992 be much faster because the Guix revision will be cached.
3994 The @code{(guix inferior)} module provides the following procedures to open an
3997 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
3998 [#:cache-directory] [#:ttl]
3999 Return an inferior for @var{channels}, a list of channels. Use the cache at
4000 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4001 This procedure opens a new connection to the build daemon.
4003 As a side effect, this procedure may build or substitute binaries for
4004 @var{channels}, which can take time.
4007 @deffn {Scheme Procedure} open-inferior @var{directory} @
4008 [#:command "bin/guix"]
4009 Open the inferior Guix in @var{directory}, running
4010 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4011 the inferior could not be launched.
4014 @cindex inferior packages
4015 The procedures listed below allow you to obtain and manipulate inferior
4018 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4019 Return the list of packages known to @var{inferior}.
4022 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4024 Return the sorted list of inferior packages matching @var{name} in
4025 @var{inferior}, with highest version numbers first. If @var{version} is true,
4026 return only packages with a version number prefixed by @var{version}.
4029 @deffn {Scheme Procedure} inferior-package? @var{obj}
4030 Return true if @var{obj} is an inferior package.
4033 @deffn {Scheme Procedure} inferior-package-name @var{package}
4034 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4035 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4036 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4037 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4038 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4039 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4040 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4041 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4042 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4043 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4044 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4045 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4046 These procedures are the counterpart of package record accessors
4047 (@pxref{package Reference}). Most of them work by querying the inferior
4048 @var{package} comes from, so the inferior must still be live when you call
4052 Inferior packages can be used transparently like any other package or
4053 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4054 transparently handled by the @code{packages->manifest} procedure, which is
4055 commonly use in manifests (@pxref{Invoking guix package, the
4056 @option{--manifest} option of @command{guix package}}). Thus you can insert
4057 an inferior package pretty much anywhere you would insert a regular package:
4058 in manifests, in the @code{packages} field of your @code{operating-system}
4059 declaration, and so on.
4061 @node Invoking guix describe
4062 @section Invoking @command{guix describe}
4064 @cindex reproducibility
4065 @cindex replicating Guix
4066 Often you may want to answer questions like: ``Which revision of Guix am I
4067 using?'' or ``Which channels am I using?'' This is useful information in many
4068 situations: if you want to @emph{replicate} an environment on a different
4069 machine or user account, if you want to report a bug or to determine what
4070 change in the channels you are using caused it, or if you want to record your
4071 system state for reproducibility purposes. The @command{guix describe}
4072 command answers these questions.
4074 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4075 displays the channel(s) that it was built from, including their repository URL
4076 and commit IDs (@pxref{Channels}):
4080 Generation 10 Sep 03 2018 17:32:44 (current)
4082 repository URL: https://git.savannah.gnu.org/git/guix.git
4084 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4087 If you're familiar with the Git version control system, this is similar in
4088 spirit to @command{git describe}; the output is also similar to that of
4089 @command{guix pull --list-generations}, but limited to the current generation
4090 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4091 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4092 information is all it takes to describe the revision of Guix you're using, and
4093 also to replicate it.
4095 To make it easier to replicate Guix, @command{guix describe} can also be asked
4096 to return a list of channels instead of the human-readable description above:
4099 $ guix describe -f channels
4102 (url "https://git.savannah.gnu.org/git/guix.git")
4104 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4108 You can save this to a file and feed it to @command{guix pull -C} on some
4109 other machine or at a later point in time, which will instantiate @emph{this
4110 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4111 From there on, since you're able to deploy the same revision of Guix, you can
4112 just as well @emph{replicate a complete software environment}. We humbly
4113 think that this is @emph{awesome}, and we hope you'll like it too!
4115 The details of the options supported by @command{guix describe} are as
4119 @item --format=@var{format}
4120 @itemx -f @var{format}
4121 Produce output in the specified @var{format}, one of:
4125 produce human-readable output;
4127 produce a list of channel specifications that can be passed to @command{guix
4128 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4132 produce a list of channel specifications in JSON format;
4134 produce a list of channel specifications in Recutils format.
4137 @item --profile=@var{profile}
4138 @itemx -p @var{profile}
4139 Display information about @var{profile}.
4142 @node Invoking guix archive
4143 @section Invoking @command{guix archive}
4145 @cindex @command{guix archive}
4147 The @command{guix archive} command allows users to @dfn{export} files
4148 from the store into a single archive, and to later @dfn{import} them on
4149 a machine that runs Guix.
4150 In particular, it allows store files to be transferred from one machine
4151 to the store on another machine.
4154 If you're looking for a way to produce archives in a format suitable for
4155 tools other than Guix, @pxref{Invoking guix pack}.
4158 @cindex exporting store items
4159 To export store files as an archive to standard output, run:
4162 guix archive --export @var{options} @var{specifications}...
4165 @var{specifications} may be either store file names or package
4166 specifications, as for @command{guix package} (@pxref{Invoking guix
4167 package}). For instance, the following command creates an archive
4168 containing the @code{gui} output of the @code{git} package and the main
4169 output of @code{emacs}:
4172 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4175 If the specified packages are not built yet, @command{guix archive}
4176 automatically builds them. The build process may be controlled with the
4177 common build options (@pxref{Common Build Options}).
4179 To transfer the @code{emacs} package to a machine connected over SSH,
4183 guix archive --export -r emacs | ssh the-machine guix archive --import
4187 Similarly, a complete user profile may be transferred from one machine
4188 to another like this:
4191 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4192 ssh the-machine guix-archive --import
4196 However, note that, in both examples, all of @code{emacs} and the
4197 profile as well as all of their dependencies are transferred (due to
4198 @code{-r}), regardless of what is already available in the store on the
4199 target machine. The @code{--missing} option can help figure out which
4200 items are missing from the target store. The @command{guix copy}
4201 command simplifies and optimizes this whole process, so this is probably
4202 what you should use in this case (@pxref{Invoking guix copy}).
4204 @cindex nar, archive format
4205 @cindex normalized archive (nar)
4206 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4207 comparable in spirit to `tar', but with differences
4208 that make it more appropriate for our purposes. First, rather than
4209 recording all Unix metadata for each file, the nar format only mentions
4210 the file type (regular, directory, or symbolic link); Unix permissions
4211 and owner/group are dismissed. Second, the order in which directory
4212 entries are stored always follows the order of file names according to
4213 the C locale collation order. This makes archive production fully
4216 When exporting, the daemon digitally signs the contents of the archive,
4217 and that digital signature is appended. When importing, the daemon
4218 verifies the signature and rejects the import in case of an invalid
4219 signature or if the signing key is not authorized.
4220 @c FIXME: Add xref to daemon doc about signatures.
4222 The main options are:
4226 Export the specified store files or packages (see below.) Write the
4227 resulting archive to the standard output.
4229 Dependencies are @emph{not} included in the output, unless
4230 @code{--recursive} is passed.
4234 When combined with @code{--export}, this instructs @command{guix
4235 archive} to include dependencies of the given items in the archive.
4236 Thus, the resulting archive is self-contained: it contains the closure
4237 of the exported store items.
4240 Read an archive from the standard input, and import the files listed
4241 therein into the store. Abort if the archive has an invalid digital
4242 signature, or if it is signed by a public key not among the authorized
4243 keys (see @code{--authorize} below.)
4246 Read a list of store file names from the standard input, one per line,
4247 and write on the standard output the subset of these files missing from
4250 @item --generate-key[=@var{parameters}]
4251 @cindex signing, archives
4252 Generate a new key pair for the daemon. This is a prerequisite before
4253 archives can be exported with @code{--export}. Note that this operation
4254 usually takes time, because it needs to gather enough entropy to
4255 generate the key pair.
4257 The generated key pair is typically stored under @file{/etc/guix}, in
4258 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4259 key, which must be kept secret.) When @var{parameters} is omitted,
4260 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4261 versions before 1.6.0, it is a 4096-bit RSA key.
4262 Alternatively, @var{parameters} can specify
4263 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4264 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4265 Libgcrypt Reference Manual}).
4268 @cindex authorizing, archives
4269 Authorize imports signed by the public key passed on standard input.
4270 The public key must be in ``s-expression advanced format''---i.e., the
4271 same format as the @file{signing-key.pub} file.
4273 The list of authorized keys is kept in the human-editable file
4274 @file{/etc/guix/acl}. The file contains
4275 @url{http://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4276 s-expressions''} and is structured as an access-control list in the
4277 @url{http://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4280 @item --extract=@var{directory}
4281 @itemx -x @var{directory}
4282 Read a single-item archive as served by substitute servers
4283 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4284 low-level operation needed in only very narrow use cases; see below.
4286 For example, the following command extracts the substitute for Emacs
4287 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4291 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
4292 | bunzip2 | guix archive -x /tmp/emacs
4295 Single-item archives are different from multiple-item archives produced
4296 by @command{guix archive --export}; they contain a single store item,
4297 and they do @emph{not} embed a signature. Thus this operation does
4298 @emph{no} signature verification and its output should be considered
4301 The primary purpose of this operation is to facilitate inspection of
4302 archive contents coming from possibly untrusted substitute servers.
4307 @c *********************************************************************
4309 @chapter Development
4311 @cindex software development
4312 If you are a software developer, Guix provides tools that you should find
4313 helpful---independently of the language you're developing in. This is what
4314 this chapter is about.
4316 The @command{guix environment} command provides a convenient way to set up
4317 @dfn{development environments} containing all the dependencies and tools
4318 necessary to work on the software package of your choice. The @command{guix
4319 pack} command allows you to create @dfn{application bundles} that can be
4320 easily distributed to users who do not run Guix.
4323 * Invoking guix environment:: Setting up development environments.
4324 * Invoking guix pack:: Creating software bundles.
4327 @node Invoking guix environment
4328 @section Invoking @command{guix environment}
4330 @cindex reproducible build environments
4331 @cindex development environments
4332 @cindex @command{guix environment}
4333 @cindex environment, package build environment
4334 The purpose of @command{guix environment} is to assist hackers in
4335 creating reproducible development environments without polluting their
4336 package profile. The @command{guix environment} tool takes one or more
4337 packages, builds all of their inputs, and creates a shell
4338 environment to use them.
4340 The general syntax is:
4343 guix environment @var{options} @var{package}@dots{}
4346 The following example spawns a new shell set up for the development of
4350 guix environment guile
4353 If the needed dependencies are not built yet, @command{guix environment}
4354 automatically builds them. The environment of the new shell is an augmented
4355 version of the environment that @command{guix environment} was run in.
4356 It contains the necessary search paths for building the given package
4357 added to the existing environment variables. To create a ``pure''
4358 environment, in which the original environment variables have been unset,
4359 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
4360 environment variables such as @code{PATH} in their @file{~/.bashrc}
4361 file. As a consequence, when @code{guix environment} launches it, Bash
4362 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
4363 environment variables. It is an error to define such environment
4364 variables in @file{.bashrc}; instead, they should be defined in
4365 @file{.bash_profile}, which is sourced only by log-in shells.
4366 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
4367 details on Bash start-up files.}.
4369 @vindex GUIX_ENVIRONMENT
4370 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
4371 variable in the shell it spawns; its value is the file name of the
4372 profile of this environment. This allows users to, say, define a
4373 specific prompt for development environments in their @file{.bashrc}
4374 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4377 if [ -n "$GUIX_ENVIRONMENT" ]
4379 export PS1="\u@@\h \w [dev]\$ "
4384 ...@: or to browse the profile:
4387 $ ls "$GUIX_ENVIRONMENT/bin"
4390 Additionally, more than one package may be specified, in which case the
4391 union of the inputs for the given packages are used. For example, the
4392 command below spawns a shell where all of the dependencies of both Guile
4393 and Emacs are available:
4396 guix environment guile emacs
4399 Sometimes an interactive shell session is not desired. An arbitrary
4400 command may be invoked by placing the @code{--} token to separate the
4401 command from the rest of the arguments:
4404 guix environment guile -- make -j4
4407 In other situations, it is more convenient to specify the list of
4408 packages needed in the environment. For example, the following command
4409 runs @command{python} from an environment containing Python@tie{}2.7 and
4413 guix environment --ad-hoc python2-numpy python-2.7 -- python
4416 Furthermore, one might want the dependencies of a package and also some
4417 additional packages that are not build-time or runtime dependencies, but
4418 are useful when developing nonetheless. Because of this, the
4419 @code{--ad-hoc} flag is positional. Packages appearing before
4420 @code{--ad-hoc} are interpreted as packages whose dependencies will be
4421 added to the environment. Packages appearing after are interpreted as
4422 packages that will be added to the environment directly. For example,
4423 the following command creates a Guix development environment that
4424 additionally includes Git and strace:
4427 guix environment guix --ad-hoc git strace
4430 Sometimes it is desirable to isolate the environment as much as
4431 possible, for maximal purity and reproducibility. In particular, when
4432 using Guix on a host distro that is not Guix System, it is desirable to
4433 prevent access to @file{/usr/bin} and other system-wide resources from
4434 the development environment. For example, the following command spawns
4435 a Guile REPL in a ``container'' where only the store and the current
4436 working directory are mounted:
4439 guix environment --ad-hoc --container guile -- guile
4443 The @code{--container} option requires Linux-libre 3.19 or newer.
4446 The available options are summarized below.
4449 @item --root=@var{file}
4450 @itemx -r @var{file}
4451 @cindex persistent environment
4452 @cindex garbage collector root, for environments
4453 Make @var{file} a symlink to the profile for this environment, and
4454 register it as a garbage collector root.
4456 This is useful if you want to protect your environment from garbage
4457 collection, to make it ``persistent''.
4459 When this option is omitted, the environment is protected from garbage
4460 collection only for the duration of the @command{guix environment}
4461 session. This means that next time you recreate the same environment,
4462 you could have to rebuild or re-download packages. @xref{Invoking guix
4463 gc}, for more on GC roots.
4465 @item --expression=@var{expr}
4466 @itemx -e @var{expr}
4467 Create an environment for the package or list of packages that
4468 @var{expr} evaluates to.
4470 For example, running:
4473 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4476 starts a shell with the environment for this specific variant of the
4482 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4485 starts a shell with all the base system packages available.
4487 The above commands only use the default output of the given packages.
4488 To select other outputs, two element tuples can be specified:
4491 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4494 @item --load=@var{file}
4495 @itemx -l @var{file}
4496 Create an environment for the package or list of packages that the code
4497 within @var{file} evaluates to.
4499 As an example, @var{file} might contain a definition like this
4500 (@pxref{Defining Packages}):
4503 @verbatiminclude environment-gdb.scm
4506 @item --manifest=@var{file}
4507 @itemx -m @var{file}
4508 Create an environment for the packages contained in the manifest object
4509 returned by the Scheme code in @var{file}.
4511 This is similar to the same-named option in @command{guix package}
4512 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4516 Include all specified packages in the resulting environment, as if an
4517 @i{ad hoc} package were defined with them as inputs. This option is
4518 useful for quickly creating an environment without having to write a
4519 package expression to contain the desired inputs.
4521 For instance, the command:
4524 guix environment --ad-hoc guile guile-sdl -- guile
4527 runs @command{guile} in an environment where Guile and Guile-SDL are
4530 Note that this example implicitly asks for the default output of
4531 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4532 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4533 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4535 This option may be composed with the default behavior of @command{guix
4536 environment}. Packages appearing before @code{--ad-hoc} are interpreted
4537 as packages whose dependencies will be added to the environment, the
4538 default behavior. Packages appearing after are interpreted as packages
4539 that will be added to the environment directly.
4542 Unset existing environment variables when building the new environment, except
4543 those specified with @option{--preserve} (see below.) This has the effect of
4544 creating an environment in which search paths only contain package inputs.
4546 @item --preserve=@var{regexp}
4547 @itemx -E @var{regexp}
4548 When used alongside @option{--pure}, preserve the environment variables
4549 matching @var{regexp}---in other words, put them on a ``white list'' of
4550 environment variables that must be preserved. This option can be repeated
4554 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4558 This example runs @command{mpirun} in a context where the only environment
4559 variables defined are @code{PATH}, environment variables whose name starts
4560 with @code{SLURM}, as well as the usual ``precious'' variables (@code{HOME},
4563 @item --search-paths
4564 Display the environment variable definitions that make up the
4567 @item --system=@var{system}
4568 @itemx -s @var{system}
4569 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4574 Run @var{command} within an isolated container. The current working
4575 directory outside the container is mapped inside the container.
4576 Additionally, unless overridden with @code{--user}, a dummy home
4577 directory is created that matches the current user's home directory, and
4578 @file{/etc/passwd} is configured accordingly.
4580 The spawned process runs as the current user outside the container. Inside
4581 the container, it has the same UID and GID as the current user, unless
4582 @option{--user} is passed (see below.)
4586 For containers, share the network namespace with the host system.
4587 Containers created without this flag only have access to the loopback
4590 @item --link-profile
4592 For containers, link the environment profile to
4593 @file{~/.guix-profile} within the container. This is equivalent to
4594 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
4595 within the container. Linking will fail and abort the environment if
4596 the directory already exists, which will certainly be the case if
4597 @command{guix environment} was invoked in the user's home directory.
4599 Certain packages are configured to look in
4600 @code{~/.guix-profile} for configuration files and data;@footnote{For
4601 example, the @code{fontconfig} package inspects
4602 @file{~/.guix-profile/share/fonts} for additional fonts.}
4603 @code{--link-profile} allows these programs to behave as expected within
4606 @item --user=@var{user}
4607 @itemx -u @var{user}
4608 For containers, use the username @var{user} in place of the current
4609 user. The generated @file{/etc/passwd} entry within the container will
4610 contain the name @var{user}, the home directory will be
4611 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4612 the UID and GID inside the container are 1000. @var{user}
4613 need not exist on the system.
4615 Additionally, any shared or exposed path (see @code{--share} and
4616 @code{--expose} respectively) whose target is within the current user's
4617 home directory will be remapped relative to @file{/home/USER}; this
4618 includes the automatic mapping of the current working directory.
4621 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4623 guix environment --container --user=foo \
4624 --expose=$HOME/test \
4625 --expose=/tmp/target=$HOME/target
4628 While this will limit the leaking of user identity through home paths
4629 and each of the user fields, this is only one useful component of a
4630 broader privacy/anonymity solution---not one in and of itself.
4632 @item --expose=@var{source}[=@var{target}]
4633 For containers, expose the file system @var{source} from the host system
4634 as the read-only file system @var{target} within the container. If
4635 @var{target} is not specified, @var{source} is used as the target mount
4636 point in the container.
4638 The example below spawns a Guile REPL in a container in which the user's
4639 home directory is accessible read-only via the @file{/exchange}
4643 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
4646 @item --share=@var{source}[=@var{target}]
4647 For containers, share the file system @var{source} from the host system
4648 as the writable file system @var{target} within the container. If
4649 @var{target} is not specified, @var{source} is used as the target mount
4650 point in the container.
4652 The example below spawns a Guile REPL in a container in which the user's
4653 home directory is accessible for both reading and writing via the
4654 @file{/exchange} directory:
4657 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
4661 @command{guix environment}
4662 also supports all of the common build options that @command{guix
4663 build} supports (@pxref{Common Build Options}) as well as package
4664 transformation options (@pxref{Package Transformation Options}).
4666 @node Invoking guix pack
4667 @section Invoking @command{guix pack}
4669 Occasionally you want to pass software to people who are not (yet!)
4670 lucky enough to be using Guix. You'd tell them to run @command{guix
4671 package -i @var{something}}, but that's not possible in this case. This
4672 is where @command{guix pack} comes in.
4675 If you are looking for ways to exchange binaries among machines that
4676 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
4677 publish}, and @ref{Invoking guix archive}.
4682 @cindex application bundle
4683 @cindex software bundle
4684 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
4685 @dfn{software bundle}: it creates a tarball or some other archive
4686 containing the binaries of the software you're interested in, and all
4687 its dependencies. The resulting archive can be used on any machine that
4688 does not have Guix, and people can run the exact same binaries as those
4689 you have with Guix. The pack itself is created in a bit-reproducible
4690 fashion, so anyone can verify that it really contains the build results
4691 that you pretend to be shipping.
4693 For example, to create a bundle containing Guile, Emacs, Geiser, and all
4694 their dependencies, you can run:
4697 $ guix pack guile emacs geiser
4699 /gnu/store/@dots{}-pack.tar.gz
4702 The result here is a tarball containing a @file{/gnu/store} directory
4703 with all the relevant packages. The resulting tarball contains a
4704 @dfn{profile} with the three packages of interest; the profile is the
4705 same as would be created by @command{guix package -i}. It is this
4706 mechanism that is used to create Guix's own standalone binary tarball
4707 (@pxref{Binary Installation}).
4709 Users of this pack would have to run
4710 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
4711 find inconvenient. To work around it, you can create, say, a
4712 @file{/opt/gnu/bin} symlink to the profile:
4715 guix pack -S /opt/gnu/bin=bin guile emacs geiser
4719 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
4721 @cindex relocatable binaries, with @command{guix pack}
4722 What if the recipient of your pack does not have root privileges on
4723 their machine, and thus cannot unpack it in the root file system? In
4724 that case, you will want to use the @code{--relocatable} option (see
4725 below). This option produces @dfn{relocatable binaries}, meaning they
4726 they can be placed anywhere in the file system hierarchy: in the example
4727 above, users can unpack your tarball in their home directory and
4728 directly run @file{./opt/gnu/bin/guile}.
4730 @cindex Docker, build an image with guix pack
4731 Alternatively, you can produce a pack in the Docker image format using
4732 the following command:
4735 guix pack -f docker guile emacs geiser
4739 The result is a tarball that can be passed to the @command{docker load}
4741 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
4742 documentation} for more information.
4744 @cindex Singularity, build an image with guix pack
4745 @cindex SquashFS, build an image with guix pack
4746 Yet another option is to produce a SquashFS image with the following
4750 guix pack -f squashfs guile emacs geiser
4754 The result is a SquashFS file system image that can either be mounted or
4755 directly be used as a file system container image with the
4756 @uref{http://singularity.lbl.gov, Singularity container execution
4757 environment}, using commands like @command{singularity shell} or
4758 @command{singularity exec}.
4760 Several command-line options allow you to customize your pack:
4763 @item --format=@var{format}
4764 @itemx -f @var{format}
4765 Produce a pack in the given @var{format}.
4767 The available formats are:
4771 This is the default format. It produces a tarball containing all the
4772 specified binaries and symlinks.
4775 This produces a tarball that follows the
4776 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
4777 Docker Image Specification}.
4780 This produces a SquashFS image containing all the specified binaries and
4781 symlinks, as well as empty mount points for virtual file systems like
4785 @cindex relocatable binaries
4788 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
4789 anywhere in the file system hierarchy and run from there.
4791 When this option is passed once, the resulting binaries require support for
4792 @dfn{user namespaces} in the kernel Linux; when passed
4793 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
4794 PRoot support, can be thought of as the abbreviation of ``Really
4795 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
4796 if user namespaces are unavailable, and essentially work anywhere---see below
4797 for the implications.
4799 For example, if you create a pack containing Bash with:
4802 guix pack -RR -S /mybin=bin bash
4806 ...@: you can copy that pack to a machine that lacks Guix, and from your
4807 home directory as a normal user, run:
4815 In that shell, if you type @code{ls /gnu/store}, you'll notice that
4816 @file{/gnu/store} shows up and contains all the dependencies of
4817 @code{bash}, even though the machine actually lacks @file{/gnu/store}
4818 altogether! That is probably the simplest way to deploy Guix-built
4819 software on a non-Guix machine.
4822 By default, relocatable binaries rely on the @dfn{user namespace} feature of
4823 the kernel Linux, which allows unprivileged users to mount or change root.
4824 Old versions of Linux did not support it, and some GNU/Linux distributions
4827 To produce relocatable binaries that work even in the absence of user
4828 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
4829 case, binaries will try user namespace support and fall back to PRoot if user
4830 namespaces are not supported.
4832 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
4833 support for file system virtualization. It achieves that by using the
4834 @code{ptrace} system call on the running program. This approach has the
4835 advantage to work without requiring special kernel support, but it incurs
4836 run-time overhead every time a system call is made.
4839 @item --expression=@var{expr}
4840 @itemx -e @var{expr}
4841 Consider the package @var{expr} evaluates to.
4843 This has the same purpose as the same-named option in @command{guix
4844 build} (@pxref{Additional Build Options, @code{--expression} in
4845 @command{guix build}}).
4847 @item --manifest=@var{file}
4848 @itemx -m @var{file}
4849 Use the packages contained in the manifest object returned by the Scheme
4852 This has a similar purpose as the same-named option in @command{guix
4853 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
4854 same manifest files. It allows you to define a collection of packages
4855 once and use it both for creating profiles and for creating archives
4856 for use on machines that do not have Guix installed. Note that you can
4857 specify @emph{either} a manifest file @emph{or} a list of packages,
4860 @item --system=@var{system}
4861 @itemx -s @var{system}
4862 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4863 the system type of the build host.
4865 @item --target=@var{triplet}
4866 @cindex cross-compilation
4867 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
4868 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
4869 configuration triplets,, autoconf, Autoconf}).
4871 @item --compression=@var{tool}
4872 @itemx -C @var{tool}
4873 Compress the resulting tarball using @var{tool}---one of @code{gzip},
4874 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
4876 @item --symlink=@var{spec}
4877 @itemx -S @var{spec}
4878 Add the symlinks specified by @var{spec} to the pack. This option can
4879 appear several times.
4881 @var{spec} has the form @code{@var{source}=@var{target}}, where
4882 @var{source} is the symlink that will be created and @var{target} is the
4885 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
4886 symlink pointing to the @file{bin} sub-directory of the profile.
4888 @item --save-provenance
4889 Save provenance information for the packages passed on the command line.
4890 Provenance information includes the URL and commit of the channels in use
4893 Provenance information is saved in the
4894 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
4895 usual package metadata---the name and version of each package, their
4896 propagated inputs, and so on. It is useful information to the recipient of
4897 the pack, who then knows how the pack was (supposedly) obtained.
4899 This option is not enabled by default because, like timestamps, provenance
4900 information contributes nothing to the build process. In other words, there
4901 is an infinity of channel URLs and commit IDs that can lead to the same pack.
4902 Recording such ``silent'' metadata in the output thus potentially breaks the
4903 source-to-binary bitwise reproducibility property.
4905 @item --localstatedir
4906 @itemx --profile-name=@var{name}
4907 Include the ``local state directory'', @file{/var/guix}, in the resulting
4908 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
4909 profile---by default @var{name} is @code{guix-profile}, which corresponds to
4910 @file{~root/.guix-profile}.
4912 @file{/var/guix} contains the store database (@pxref{The Store}) as well
4913 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
4914 the pack means that the store is ``complete'' and manageable by Guix;
4915 not providing it pack means that the store is ``dead'': items cannot be
4916 added to it or removed from it after extraction of the pack.
4918 One use case for this is the Guix self-contained binary tarball
4919 (@pxref{Binary Installation}).
4922 Use the bootstrap binaries to build the pack. This option is only
4923 useful to Guix developers.
4926 In addition, @command{guix pack} supports all the common build options
4927 (@pxref{Common Build Options}) and all the package transformation
4928 options (@pxref{Package Transformation Options}).
4931 @c *********************************************************************
4932 @node Programming Interface
4933 @chapter Programming Interface
4935 GNU Guix provides several Scheme programming interfaces (APIs) to
4936 define, build, and query packages. The first interface allows users to
4937 write high-level package definitions. These definitions refer to
4938 familiar packaging concepts, such as the name and version of a package,
4939 its build system, and its dependencies. These definitions can then be
4940 turned into concrete build actions.
4942 Build actions are performed by the Guix daemon, on behalf of users. In a
4943 standard setup, the daemon has write access to the store---the
4944 @file{/gnu/store} directory---whereas users do not. The recommended
4945 setup also has the daemon perform builds in chroots, under a specific
4946 build users, to minimize interference with the rest of the system.
4949 Lower-level APIs are available to interact with the daemon and the
4950 store. To instruct the daemon to perform a build action, users actually
4951 provide it with a @dfn{derivation}. A derivation is a low-level
4952 representation of the build actions to be taken, and the environment in
4953 which they should occur---derivations are to package definitions what
4954 assembly is to C programs. The term ``derivation'' comes from the fact
4955 that build results @emph{derive} from them.
4957 This chapter describes all these APIs in turn, starting from high-level
4958 package definitions.
4961 * Package Modules:: Packages from the programmer's viewpoint.
4962 * Defining Packages:: Defining new packages.
4963 * Build Systems:: Specifying how packages are built.
4964 * The Store:: Manipulating the package store.
4965 * Derivations:: Low-level interface to package derivations.
4966 * The Store Monad:: Purely functional interface to the store.
4967 * G-Expressions:: Manipulating build expressions.
4968 * Invoking guix repl:: Fiddling with Guix interactively.
4971 @node Package Modules
4972 @section Package Modules
4974 From a programming viewpoint, the package definitions of the
4975 GNU distribution are provided by Guile modules in the @code{(gnu packages
4976 @dots{})} name space@footnote{Note that packages under the @code{(gnu
4977 packages @dots{})} module name space are not necessarily ``GNU
4978 packages''. This module naming scheme follows the usual Guile module
4979 naming convention: @code{gnu} means that these modules are distributed
4980 as part of the GNU system, and @code{packages} identifies modules that
4981 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
4982 Reference Manual}). For instance, the @code{(gnu packages emacs)}
4983 module exports a variable named @code{emacs}, which is bound to a
4984 @code{<package>} object (@pxref{Defining Packages}).
4986 The @code{(gnu packages @dots{})} module name space is
4987 automatically scanned for packages by the command-line tools. For
4988 instance, when running @code{guix package -i emacs}, all the @code{(gnu
4989 packages @dots{})} modules are scanned until one that exports a package
4990 object whose name is @code{emacs} is found. This package search
4991 facility is implemented in the @code{(gnu packages)} module.
4993 @cindex customization, of packages
4994 @cindex package module search path
4995 Users can store package definitions in modules with different
4996 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
4997 name and module name must match. For instance, the @code{(my-packages
4998 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
4999 relative to the load path specified with @option{--load-path} or
5000 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5001 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5002 these package definitions visible to the user interfaces:
5006 By adding the directory containing your package modules to the search path
5007 with the @code{-L} flag of @command{guix package} and other commands
5008 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
5009 environment variable described below.
5012 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5013 pulls from it. A channel is essentially a Git repository containing package
5014 modules. @xref{Channels}, for more information on how to define and use
5018 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5020 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5021 This is a colon-separated list of directories to search for additional
5022 package modules. Directories listed in this variable take precedence
5023 over the own modules of the distribution.
5026 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5027 each package is built based solely on other packages in the
5028 distribution. The root of this dependency graph is a small set of
5029 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5030 bootstrap)} module. For more information on bootstrapping,
5031 @pxref{Bootstrapping}.
5033 @node Defining Packages
5034 @section Defining Packages
5036 The high-level interface to package definitions is implemented in the
5037 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5038 example, the package definition, or @dfn{recipe}, for the GNU Hello
5039 package looks like this:
5042 (define-module (gnu packages hello)
5043 #:use-module (guix packages)
5044 #:use-module (guix download)
5045 #:use-module (guix build-system gnu)
5046 #:use-module (guix licenses)
5047 #:use-module (gnu packages gawk))
5049 (define-public hello
5055 (uri (string-append "mirror://gnu/hello/hello-" version
5059 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5060 (build-system gnu-build-system)
5061 (arguments '(#:configure-flags '("--enable-silent-rules")))
5062 (inputs `(("gawk" ,gawk)))
5063 (synopsis "Hello, GNU world: An example GNU package")
5064 (description "Guess what GNU Hello prints!")
5065 (home-page "http://www.gnu.org/software/hello/")
5070 Without being a Scheme expert, the reader may have guessed the meaning
5071 of the various fields here. This expression binds the variable
5072 @code{hello} to a @code{<package>} object, which is essentially a record
5073 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5074 This package object can be inspected using procedures found in the
5075 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5076 returns---surprise!---@code{"hello"}.
5078 With luck, you may be able to import part or all of the definition of
5079 the package you are interested in from another repository, using the
5080 @code{guix import} command (@pxref{Invoking guix import}).
5082 In the example above, @var{hello} is defined in a module of its own,
5083 @code{(gnu packages hello)}. Technically, this is not strictly
5084 necessary, but it is convenient to do so: all the packages defined in
5085 modules under @code{(gnu packages @dots{})} are automatically known to
5086 the command-line tools (@pxref{Package Modules}).
5088 There are a few points worth noting in the above package definition:
5092 The @code{source} field of the package is an @code{<origin>} object
5093 (@pxref{origin Reference}, for the complete reference).
5094 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5095 meaning that the source is a file to be downloaded over FTP or HTTP.
5097 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5098 the GNU mirrors defined in @code{(guix download)}.
5100 The @code{sha256} field specifies the expected SHA256 hash of the file
5101 being downloaded. It is mandatory, and allows Guix to check the
5102 integrity of the file. The @code{(base32 @dots{})} form introduces the
5103 base32 representation of the hash. You can obtain this information with
5104 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5105 hash} (@pxref{Invoking guix hash}).
5108 When needed, the @code{origin} form can also have a @code{patches} field
5109 listing patches to be applied, and a @code{snippet} field giving a
5110 Scheme expression to modify the source code.
5113 @cindex GNU Build System
5114 The @code{build-system} field specifies the procedure to build the
5115 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5116 represents the familiar GNU Build System, where packages may be
5117 configured, built, and installed with the usual @code{./configure &&
5118 make && make check && make install} command sequence.
5121 The @code{arguments} field specifies options for the build system
5122 (@pxref{Build Systems}). Here it is interpreted by
5123 @var{gnu-build-system} as a request run @file{configure} with the
5124 @code{--enable-silent-rules} flag.
5130 What about these quote (@code{'}) characters? They are Scheme syntax to
5131 introduce a literal list; @code{'} is synonymous with @code{quote}.
5132 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5133 for details. Here the value of the @code{arguments} field is a list of
5134 arguments passed to the build system down the road, as with @code{apply}
5135 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5138 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5139 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5140 @code{#:configure-flags} is a keyword used to pass a keyword argument
5141 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5145 The @code{inputs} field specifies inputs to the build process---i.e.,
5146 build-time or run-time dependencies of the package. Here, we define an
5147 input called @code{"gawk"} whose value is that of the @var{gawk}
5148 variable; @var{gawk} is itself bound to a @code{<package>} object.
5150 @cindex backquote (quasiquote)
5153 @cindex comma (unquote)
5157 @findex unquote-splicing
5158 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5159 us to introduce a literal list in the @code{inputs} field, while
5160 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5161 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5164 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5165 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5166 of ensuring that they are present (@pxref{Build Systems}).
5168 However, any other dependencies need to be specified in the
5169 @code{inputs} field. Any dependency not specified here will simply be
5170 unavailable to the build process, possibly leading to a build failure.
5173 @xref{package Reference}, for a full description of possible fields.
5175 Once a package definition is in place, the
5176 package may actually be built using the @code{guix build} command-line
5177 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5178 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5179 package definition using the @command{guix edit} command
5180 (@pxref{Invoking guix edit}).
5181 @xref{Packaging Guidelines}, for
5182 more information on how to test package definitions, and
5183 @ref{Invoking guix lint}, for information on how to check a definition
5184 for style conformance.
5185 @vindex GUIX_PACKAGE_PATH
5186 Lastly, @pxref{Channels}, for information
5187 on how to extend the distribution by adding your own package definitions
5190 Finally, updating the package definition to a new upstream version
5191 can be partly automated by the @command{guix refresh} command
5192 (@pxref{Invoking guix refresh}).
5194 Behind the scenes, a derivation corresponding to the @code{<package>}
5195 object is first computed by the @code{package-derivation} procedure.
5196 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
5197 The build actions it prescribes may then be realized by using the
5198 @code{build-derivations} procedure (@pxref{The Store}).
5200 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5201 Return the @code{<derivation>} object of @var{package} for @var{system}
5202 (@pxref{Derivations}).
5204 @var{package} must be a valid @code{<package>} object, and @var{system}
5205 must be a string denoting the target system type---e.g.,
5206 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5207 must be a connection to the daemon, which operates on the store
5208 (@pxref{The Store}).
5212 @cindex cross-compilation
5213 Similarly, it is possible to compute a derivation that cross-builds a
5214 package for some other system:
5216 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5217 @var{package} @var{target} [@var{system}]
5218 Return the @code{<derivation>} object of @var{package} cross-built from
5219 @var{system} to @var{target}.
5221 @var{target} must be a valid GNU triplet denoting the target hardware
5222 and operating system, such as @code{"mips64el-linux-gnu"}
5223 (@pxref{Configuration Names, GNU configuration triplets,, configure, GNU
5224 Configure and Build System}).
5227 @cindex package transformations
5228 @cindex input rewriting
5229 @cindex dependency tree rewriting
5230 Packages can be manipulated in arbitrary ways. An example of a useful
5231 transformation is @dfn{input rewriting}, whereby the dependency tree of
5232 a package is rewritten by replacing specific inputs by others:
5234 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5235 [@var{rewrite-name}]
5236 Return a procedure that, when passed a package, replaces its direct and
5237 indirect dependencies (but not its implicit inputs) according to
5238 @var{replacements}. @var{replacements} is a list of package pairs; the
5239 first element of each pair is the package to replace, and the second one
5242 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5243 the name of a package and returns its new name after rewrite.
5247 Consider this example:
5250 (define libressl-instead-of-openssl
5251 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5253 (package-input-rewriting `((,openssl . ,libressl))))
5255 (define git-with-libressl
5256 (libressl-instead-of-openssl git))
5260 Here we first define a rewriting procedure that replaces @var{openssl}
5261 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5262 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5263 This is exactly what the @option{--with-input} command-line option does
5264 (@pxref{Package Transformation Options, @option{--with-input}}).
5266 The following variant of @code{package-input-rewriting} can match packages to
5267 be replaced by name rather than by identity.
5269 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5270 Return a procedure that, given a package, applies the given @var{replacements} to
5271 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5272 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5273 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5274 replacement for that package.
5277 The example above could be rewritten this way:
5280 (define libressl-instead-of-openssl
5281 ;; Replace all the packages called "openssl" with LibreSSL.
5282 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5285 The key difference here is that, this time, packages are matched by spec and
5286 not by identity. In other words, any package in the graph that is called
5287 @code{openssl} will be replaced.
5289 A more generic procedure to rewrite a package dependency graph is
5290 @code{package-mapping}: it supports arbitrary changes to nodes in the
5293 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5294 Return a procedure that, given a package, applies @var{proc} to all the packages
5295 depended on and returns the resulting package. The procedure stops recursion
5296 when @var{cut?} returns true for a given package.
5300 * package Reference:: The package data type.
5301 * origin Reference:: The origin data type.
5305 @node package Reference
5306 @subsection @code{package} Reference
5308 This section summarizes all the options available in @code{package}
5309 declarations (@pxref{Defining Packages}).
5311 @deftp {Data Type} package
5312 This is the data type representing a package recipe.
5316 The name of the package, as a string.
5318 @item @code{version}
5319 The version of the package, as a string.
5322 An object telling how the source code for the package should be
5323 acquired. Most of the time, this is an @code{origin} object, which
5324 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5325 can also be any other ``file-like'' object such as a @code{local-file},
5326 which denotes a file from the local file system (@pxref{G-Expressions,
5327 @code{local-file}}).
5329 @item @code{build-system}
5330 The build system that should be used to build the package (@pxref{Build
5333 @item @code{arguments} (default: @code{'()})
5334 The arguments that should be passed to the build system. This is a
5335 list, typically containing sequential keyword-value pairs.
5337 @item @code{inputs} (default: @code{'()})
5338 @itemx @code{native-inputs} (default: @code{'()})
5339 @itemx @code{propagated-inputs} (default: @code{'()})
5340 @cindex inputs, of packages
5341 These fields list dependencies of the package. Each one is a list of
5342 tuples, where each tuple has a label for the input (a string) as its
5343 first element, a package, origin, or derivation as its second element,
5344 and optionally the name of the output thereof that should be used, which
5345 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5346 more on package outputs). For example, the list below specifies three
5350 `(("libffi" ,libffi)
5351 ("libunistring" ,libunistring)
5352 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5355 @cindex cross compilation, package dependencies
5356 The distinction between @code{native-inputs} and @code{inputs} is
5357 necessary when considering cross-compilation. When cross-compiling,
5358 dependencies listed in @code{inputs} are built for the @emph{target}
5359 architecture; conversely, dependencies listed in @code{native-inputs}
5360 are built for the architecture of the @emph{build} machine.
5362 @code{native-inputs} is typically used to list tools needed at
5363 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5364 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5365 this area (@pxref{Invoking guix lint}).
5367 @anchor{package-propagated-inputs}
5368 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5369 specified packages will be automatically installed alongside the package
5370 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5371 package}}, for information on how @command{guix package} deals with
5374 For example this is necessary when a C/C++ library needs headers of
5375 another library to compile, or when a pkg-config file refers to another
5376 one @i{via} its @code{Requires} field.
5378 Another example where @code{propagated-inputs} is useful is for languages
5379 that lack a facility to record the run-time search path akin to the
5380 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5381 more. To ensure that libraries written in those languages can find
5382 library code they depend on at run time, run-time dependencies must be
5383 listed in @code{propagated-inputs} rather than @code{inputs}.
5385 @item @code{outputs} (default: @code{'("out")})
5386 The list of output names of the package. @xref{Packages with Multiple
5387 Outputs}, for typical uses of additional outputs.
5389 @item @code{native-search-paths} (default: @code{'()})
5390 @itemx @code{search-paths} (default: @code{'()})
5391 A list of @code{search-path-specification} objects describing
5392 search-path environment variables honored by the package.
5394 @item @code{replacement} (default: @code{#f})
5395 This must be either @code{#f} or a package object that will be used as a
5396 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5399 @item @code{synopsis}
5400 A one-line description of the package.
5402 @item @code{description}
5403 A more elaborate description of the package.
5405 @item @code{license}
5406 @cindex license, of packages
5407 The license of the package; a value from @code{(guix licenses)},
5408 or a list of such values.
5410 @item @code{home-page}
5411 The URL to the home-page of the package, as a string.
5413 @item @code{supported-systems} (default: @var{%supported-systems})
5414 The list of systems supported by the package, as strings of the form
5415 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5417 @item @code{maintainers} (default: @code{'()})
5418 The list of maintainers of the package, as @code{maintainer} objects.
5420 @item @code{location} (default: source location of the @code{package} form)
5421 The source location of the package. It is useful to override this when
5422 inheriting from another package, in which case this field is not
5423 automatically corrected.
5428 @node origin Reference
5429 @subsection @code{origin} Reference
5431 This section summarizes all the options available in @code{origin}
5432 declarations (@pxref{Defining Packages}).
5434 @deftp {Data Type} origin
5435 This is the data type representing a source code origin.
5439 An object containing the URI of the source. The object type depends on
5440 the @code{method} (see below). For example, when using the
5441 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5442 values are: a URL represented as a string, or a list thereof.
5445 A procedure that handles the URI.
5450 @item @var{url-fetch} from @code{(guix download)}
5451 download a file from the HTTP, HTTPS, or FTP URL specified in the
5455 @item @var{git-fetch} from @code{(guix git-download)}
5456 clone the Git version control repository, and check out the revision
5457 specified in the @code{uri} field as a @code{git-reference} object; a
5458 @code{git-reference} looks like this:
5462 (url "git://git.debian.org/git/pkg-shadow/shadow")
5463 (commit "v4.1.5.1"))
5468 A bytevector containing the SHA-256 hash of the source. Typically the
5469 @code{base32} form is used here to generate the bytevector from a
5472 You can obtain this information using @code{guix download}
5473 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5476 @item @code{file-name} (default: @code{#f})
5477 The file name under which the source code should be saved. When this is
5478 @code{#f}, a sensible default value will be used in most cases. In case
5479 the source is fetched from a URL, the file name from the URL will be
5480 used. For version control checkouts, it is recommended to provide the
5481 file name explicitly because the default is not very descriptive.
5483 @item @code{patches} (default: @code{'()})
5484 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5485 file-like objects}) pointing to patches to be applied to the source.
5487 This list of patches must be unconditional. In particular, it cannot
5488 depend on the value of @code{%current-system} or
5489 @code{%current-target-system}.
5491 @item @code{snippet} (default: @code{#f})
5492 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5493 in the source directory. This is a convenient way to modify the source,
5494 sometimes more convenient than a patch.
5496 @item @code{patch-flags} (default: @code{'("-p1")})
5497 A list of command-line flags that should be passed to the @code{patch}
5500 @item @code{patch-inputs} (default: @code{#f})
5501 Input packages or derivations to the patching process. When this is
5502 @code{#f}, the usual set of inputs necessary for patching are provided,
5503 such as GNU@tie{}Patch.
5505 @item @code{modules} (default: @code{'()})
5506 A list of Guile modules that should be loaded during the patching
5507 process and while running the code in the @code{snippet} field.
5509 @item @code{patch-guile} (default: @code{#f})
5510 The Guile package that should be used in the patching process. When
5511 this is @code{#f}, a sensible default is used.
5517 @section Build Systems
5519 @cindex build system
5520 Each package definition specifies a @dfn{build system} and arguments for
5521 that build system (@pxref{Defining Packages}). This @code{build-system}
5522 field represents the build procedure of the package, as well as implicit
5523 dependencies of that build procedure.
5525 Build systems are @code{<build-system>} objects. The interface to
5526 create and manipulate them is provided by the @code{(guix build-system)}
5527 module, and actual build systems are exported by specific modules.
5529 @cindex bag (low-level package representation)
5530 Under the hood, build systems first compile package objects to
5531 @dfn{bags}. A @dfn{bag} is like a package, but with less
5532 ornamentation---in other words, a bag is a lower-level representation of
5533 a package, which includes all the inputs of that package, including some
5534 that were implicitly added by the build system. This intermediate
5535 representation is then compiled to a derivation (@pxref{Derivations}).
5537 Build systems accept an optional list of @dfn{arguments}. In package
5538 definitions, these are passed @i{via} the @code{arguments} field
5539 (@pxref{Defining Packages}). They are typically keyword arguments
5540 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
5541 Guile Reference Manual}). The value of these arguments is usually
5542 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
5543 by the daemon (@pxref{Derivations}).
5545 The main build system is @var{gnu-build-system}, which implements the
5546 standard build procedure for GNU and many other packages. It
5547 is provided by the @code{(guix build-system gnu)} module.
5549 @defvr {Scheme Variable} gnu-build-system
5550 @var{gnu-build-system} represents the GNU Build System, and variants
5551 thereof (@pxref{Configuration, configuration and makefile conventions,,
5552 standards, GNU Coding Standards}).
5554 @cindex build phases
5555 In a nutshell, packages using it are configured, built, and installed with
5556 the usual @code{./configure && make && make check && make install}
5557 command sequence. In practice, a few additional steps are often needed.
5558 All these steps are split up in separate @dfn{phases},
5559 notably@footnote{Please see the @code{(guix build gnu-build-system)}
5560 modules for more details about the build phases.}:
5564 Unpack the source tarball, and change the current directory to the
5565 extracted source tree. If the source is actually a directory, copy it
5566 to the build tree, and enter that directory.
5568 @item patch-source-shebangs
5569 Patch shebangs encountered in source files so they refer to the right
5570 store file names. For instance, this changes @code{#!/bin/sh} to
5571 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
5574 Run the @file{configure} script with a number of default options, such
5575 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
5576 by the @code{#:configure-flags} argument.
5579 Run @code{make} with the list of flags specified with
5580 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
5581 (the default), build with @code{make -j}.
5584 Run @code{make check}, or some other target specified with
5585 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
5586 @code{#:parallel-tests?} argument is true (the default), run @code{make
5590 Run @code{make install} with the flags listed in @code{#:make-flags}.
5592 @item patch-shebangs
5593 Patch shebangs on the installed executable files.
5596 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
5597 is false), copying them to the @code{debug} output when available
5598 (@pxref{Installing Debugging Files}).
5601 @vindex %standard-phases
5602 The build-side module @code{(guix build gnu-build-system)} defines
5603 @var{%standard-phases} as the default list of build phases.
5604 @var{%standard-phases} is a list of symbol/procedure pairs, where the
5605 procedure implements the actual phase.
5607 The list of phases used for a particular package can be changed with the
5608 @code{#:phases} parameter. For instance, passing:
5611 #:phases (modify-phases %standard-phases (delete 'configure))
5614 means that all the phases described above will be used, except the
5615 @code{configure} phase.
5617 In addition, this build system ensures that the ``standard'' environment
5618 for GNU packages is available. This includes tools such as GCC, libc,
5619 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
5620 build-system gnu)} module for a complete list). We call these the
5621 @dfn{implicit inputs} of a package, because package definitions do not
5622 have to mention them.
5625 Other @code{<build-system>} objects are defined to support other
5626 conventions and tools used by free software packages. They inherit most
5627 of @var{gnu-build-system}, and differ mainly in the set of inputs
5628 implicitly added to the build process, and in the list of phases
5629 executed. Some of these build systems are listed below.
5631 @defvr {Scheme Variable} ant-build-system
5632 This variable is exported by @code{(guix build-system ant)}. It
5633 implements the build procedure for Java packages that can be built with
5634 @url{http://ant.apache.org/, Ant build tool}.
5636 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
5637 provided by the @code{icedtea} package to the set of inputs. Different
5638 packages can be specified with the @code{#:ant} and @code{#:jdk}
5639 parameters, respectively.
5641 When the original package does not provide a suitable Ant build file,
5642 the parameter @code{#:jar-name} can be used to generate a minimal Ant
5643 build file @file{build.xml} with tasks to build the specified jar
5644 archive. In this case the parameter @code{#:source-dir} can be used to
5645 specify the source sub-directory, defaulting to ``src''.
5647 The @code{#:main-class} parameter can be used with the minimal ant
5648 buildfile to specify the main class of the resulting jar. This makes the
5649 jar file executable. The @code{#:test-include} parameter can be used to
5650 specify the list of junit tests to run. It defaults to
5651 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
5652 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
5653 because abstract classes cannot be run as tests.
5655 The parameter @code{#:build-target} can be used to specify the Ant task
5656 that should be run during the @code{build} phase. By default the
5657 ``jar'' task will be run.
5661 @defvr {Scheme Variable} android-ndk-build-system
5662 @cindex Android distribution
5663 @cindex Android NDK build system
5664 This variable is exported by @code{(guix build-system android-ndk)}. It
5665 implements a build procedure for Android NDK (native development kit)
5666 packages using a Guix-specific build process.
5668 The build system assumes that packages install their public interface
5669 (header) files to the subdirectory "include" of the "out" output and
5670 their libraries to the subdirectory "lib" of the "out" output.
5672 It's also assumed that the union of all the dependencies of a package
5673 has no conflicting files.
5675 For the time being, cross-compilation is not supported - so right now
5676 the libraries and header files are assumed to be host tools.
5680 @defvr {Scheme Variable} asdf-build-system/source
5681 @defvrx {Scheme Variable} asdf-build-system/sbcl
5682 @defvrx {Scheme Variable} asdf-build-system/ecl
5684 These variables, exported by @code{(guix build-system asdf)}, implement
5685 build procedures for Common Lisp packages using
5686 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
5687 definition facility for Common Lisp programs and libraries.
5689 The @code{asdf-build-system/source} system installs the packages in
5690 source form, and can be loaded using any common lisp implementation, via
5691 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
5692 systems in the format which a particular implementation understands.
5693 These build systems can also be used to produce executable programs, or
5694 lisp images which contain a set of packages pre-loaded.
5696 The build system uses naming conventions. For binary packages, the
5697 package name should be prefixed with the lisp implementation, such as
5698 @code{sbcl-} for @code{asdf-build-system/sbcl}.
5700 Additionally, the corresponding source package should be labeled using
5701 the same convention as python packages (see @ref{Python Modules}), using
5702 the @code{cl-} prefix.
5704 For binary packages, each system should be defined as a Guix package.
5705 If one package @code{origin} contains several systems, package variants
5706 can be created in order to build all the systems. Source packages,
5707 which use @code{asdf-build-system/source}, may contain several systems.
5709 In order to create executable programs and images, the build-side
5710 procedures @code{build-program} and @code{build-image} can be used.
5711 They should be called in a build phase after the @code{create-symlinks}
5712 phase, so that the system which was just built can be used within the
5713 resulting image. @code{build-program} requires a list of Common Lisp
5714 expressions to be passed as the @code{#:entry-program} argument.
5716 If the system is not defined within its own @code{.asd} file of the same
5717 name, then the @code{#:asd-file} parameter should be used to specify
5718 which file the system is defined in. Furthermore, if the package
5719 defines a system for its tests in a separate file, it will be loaded
5720 before the tests are run if it is specified by the
5721 @code{#:test-asd-file} parameter. If it is not set, the files
5722 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
5723 and @code{test.asd} will be tried if they exist.
5725 If for some reason the package must be named in a different way than the
5726 naming conventions suggest, the @code{#:asd-system-name} parameter can
5727 be used to specify the name of the system.
5731 @defvr {Scheme Variable} cargo-build-system
5732 @cindex Rust programming language
5733 @cindex Cargo (Rust build system)
5734 This variable is exported by @code{(guix build-system cargo)}. It
5735 supports builds of packages using Cargo, the build tool of the
5736 @uref{https://www.rust-lang.org, Rust programming language}.
5738 In its @code{configure} phase, this build system replaces dependencies
5739 specified in the @file{Carto.toml} file with inputs to the Guix package.
5740 The @code{install} phase installs the binaries, and it also installs the
5741 source code and @file{Cargo.toml} file.
5744 @cindex Clojure (programming language)
5745 @cindex simple Clojure build system
5746 @defvr {Scheme Variable} clojure-build-system
5747 This variable is exported by @code{(guix build-system clojure)}. It implements
5748 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
5749 using plain old @code{compile} in Clojure. Cross-compilation is not supported
5752 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
5753 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
5754 @code{#:zip} parameters, respectively.
5756 A list of source directories, test directories and jar names can be specified
5757 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
5758 parameters, respectively. Compile directory and main class can be specified
5759 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
5760 Other parameters are documented below.
5762 This build system is an extension of @var{ant-build-system}, but with the
5763 following phases changed:
5768 This phase calls @code{compile} in Clojure to compile source files and runs
5769 @command{jar} to create jars from both source files and compiled files
5770 according to the include list and exclude list specified in
5771 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
5772 has priority over the include list. These lists consist of symbols
5773 representing Clojure libraries or the special keyword @code{#:all} representing
5774 all Clojure libraries found under the source directories. The parameter
5775 @code{#:omit-source?} decides if source should be included into the jars.
5778 This phase runs tests according to the include list and exclude list specified
5779 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
5780 meanings are analogous to that of @code{#:aot-include} and
5781 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
5782 stands for all Clojure libraries found under the test directories. The
5783 parameter @code{#:tests?} decides if tests should be run.
5786 This phase installs all jars built previously.
5789 Apart from the above, this build system also contains an additional phase:
5794 This phase installs all top-level files with base name matching
5795 @var{%doc-regex}. A different regex can be specified with the
5796 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
5797 directories specified in @code{#:doc-dirs} are installed as well.
5801 @defvr {Scheme Variable} cmake-build-system
5802 This variable is exported by @code{(guix build-system cmake)}. It
5803 implements the build procedure for packages using the
5804 @url{http://www.cmake.org, CMake build tool}.
5806 It automatically adds the @code{cmake} package to the set of inputs.
5807 Which package is used can be specified with the @code{#:cmake}
5810 The @code{#:configure-flags} parameter is taken as a list of flags
5811 passed to the @command{cmake} command. The @code{#:build-type}
5812 parameter specifies in abstract terms the flags passed to the compiler;
5813 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
5814 debugging information''), which roughly means that code is compiled with
5815 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
5818 @defvr {Scheme Variable} dune-build-system
5819 This variable is exported by @code{(guix build-system dune)}. It
5820 supports builds of packages using @uref{https://dune.build/, Dune}, a build
5821 tool for the OCaml programming language. It is implemented as an extension
5822 of the @code{ocaml-build-system} which is described below. As such, the
5823 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
5826 It automatically adds the @code{dune} package to the set of inputs.
5827 Which package is used can be specified with the @code{#:dune}
5830 There is no @code{configure} phase because dune packages typically don't
5831 need to be configured. The @code{#:build-flags} parameter is taken as a
5832 list of flags passed to the @code{dune} command during the build.
5834 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
5835 command instead of the more recent @code{dune} command while building
5836 a package. Its default value is @code{#f}.
5838 The @code{#:package} parameter can be passed to specify a package name, which
5839 is useful when a package contains multiple packages and you want to build
5840 only one of them. This is equivalent to passing the @code{-p} argument to
5844 @defvr {Scheme Variable} go-build-system
5845 This variable is exported by @code{(guix build-system go)}. It
5846 implements a build procedure for Go packages using the standard
5847 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
5848 Go build mechanisms}.
5850 The user is expected to provide a value for the key @code{#:import-path}
5851 and, in some cases, @code{#:unpack-path}. The
5852 @url{https://golang.org/doc/code.html#ImportPaths, import path}
5853 corresponds to the file system path expected by the package's build
5854 scripts and any referring packages, and provides a unique way to
5855 refer to a Go package. It is typically based on a combination of the
5856 package source code's remote URI and file system hierarchy structure. In
5857 some cases, you will need to unpack the package's source code to a
5858 different directory structure than the one indicated by the import path,
5859 and @code{#:unpack-path} should be used in such cases.
5861 Packages that provide Go libraries should install their source code into
5862 the built output. The key @code{#:install-source?}, which defaults to
5863 @code{#t}, controls whether or not the source code is installed. It can
5864 be set to @code{#f} for packages that only provide executable files.
5867 @defvr {Scheme Variable} glib-or-gtk-build-system
5868 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
5869 is intended for use with packages making use of GLib or GTK+.
5871 This build system adds the following two phases to the ones defined by
5872 @var{gnu-build-system}:
5875 @item glib-or-gtk-wrap
5876 The phase @code{glib-or-gtk-wrap} ensures that programs in
5877 @file{bin/} are able to find GLib ``schemas'' and
5878 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
5879 modules}. This is achieved by wrapping the programs in launch scripts
5880 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
5881 environment variables.
5883 It is possible to exclude specific package outputs from that wrapping
5884 process by listing their names in the
5885 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
5886 when an output is known not to contain any GLib or GTK+ binaries, and
5887 where wrapping would gratuitously add a dependency of that output on
5890 @item glib-or-gtk-compile-schemas
5891 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
5892 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
5893 GSettings schemas} of GLib are compiled. Compilation is performed by the
5894 @command{glib-compile-schemas} program. It is provided by the package
5895 @code{glib:bin} which is automatically imported by the build system.
5896 The @code{glib} package providing @command{glib-compile-schemas} can be
5897 specified with the @code{#:glib} parameter.
5900 Both phases are executed after the @code{install} phase.
5903 @defvr {Scheme Variable} guile-build-system
5904 This build system is for Guile packages that consist exclusively of Scheme
5905 code and that are so lean that they don't even have a makefile, let alone a
5906 @file{configure} script. It compiles Scheme code using @command{guild
5907 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
5908 installs the @file{.scm} and @file{.go} files in the right place. It also
5909 installs documentation.
5911 This build system supports cross-compilation by using the @code{--target}
5912 option of @command{guild compile}.
5914 Packages built with @code{guile-build-system} must provide a Guile package in
5915 their @code{native-inputs} field.
5918 @defvr {Scheme Variable} minify-build-system
5919 This variable is exported by @code{(guix build-system minify)}. It
5920 implements a minification procedure for simple JavaScript packages.
5922 It adds @code{uglify-js} to the set of inputs and uses it to compress
5923 all JavaScript files in the @file{src} directory. A different minifier
5924 package can be specified with the @code{#:uglify-js} parameter, but it
5925 is expected that the package writes the minified code to the standard
5928 When the input JavaScript files are not all located in the @file{src}
5929 directory, the parameter @code{#:javascript-files} can be used to
5930 specify a list of file names to feed to the minifier.
5933 @defvr {Scheme Variable} ocaml-build-system
5934 This variable is exported by @code{(guix build-system ocaml)}. It implements
5935 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
5936 of choosing the correct set of commands to run for each package. OCaml
5937 packages can expect many different commands to be run. This build system will
5940 When the package has a @file{setup.ml} file present at the top-level, it will
5941 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
5942 @code{ocaml setup.ml -install}. The build system will assume that this file
5943 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
5944 care of setting the prefix and enabling tests if they are not disabled. You
5945 can pass configure and build flags with the @code{#:configure-flags} and
5946 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
5947 set of flags used to enable tests. The @code{#:use-make?} key can be used to
5948 bypass this system in the build and install phases.
5950 When the package has a @file{configure} file, it is assumed that it is a
5951 hand-made configure script that requires a different argument format than
5952 in the @code{gnu-build-system}. You can add more flags with the
5953 @code{#:configure-flags} key.
5955 When the package has a @file{Makefile} file (or @code{#:use-make?} is
5956 @code{#t}), it will be used and more flags can be passed to the build and
5957 install phases with the @code{#:make-flags} key.
5959 Finally, some packages do not have these files and use a somewhat standard
5960 location for its build system. In that case, the build system will run
5961 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
5962 providing the path to the required findlib module. Additional flags can
5963 be passed via the @code{#:build-flags} key. Install is taken care of by
5964 @command{opam-installer}. In this case, the @code{opam} package must
5965 be added to the @code{native-inputs} field of the package definition.
5967 Note that most OCaml packages assume they will be installed in the same
5968 directory as OCaml, which is not what we want in guix. In particular, they
5969 will install @file{.so} files in their module's directory, which is usually
5970 fine because it is in the OCaml compiler directory. In guix though, these
5971 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
5972 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
5973 @file{.so} libraries should be installed.
5976 @defvr {Scheme Variable} python-build-system
5977 This variable is exported by @code{(guix build-system python)}. It
5978 implements the more or less standard build procedure used by Python
5979 packages, which consists in running @code{python setup.py build} and
5980 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
5982 For packages that install stand-alone Python programs under @code{bin/},
5983 it takes care of wrapping these programs so that their @code{PYTHONPATH}
5984 environment variable points to all the Python libraries they depend on.
5986 Which Python package is used to perform the build can be specified with
5987 the @code{#:python} parameter. This is a useful way to force a package
5988 to be built for a specific version of the Python interpreter, which
5989 might be necessary if the package is only compatible with a single
5990 interpreter version.
5992 By default guix calls @code{setup.py} under control of
5993 @code{setuptools}, much like @command{pip} does. Some packages are not
5994 compatible with setuptools (and pip), thus you can disable this by
5995 setting the @code{#:use-setuptools} parameter to @code{#f}.
5998 @defvr {Scheme Variable} perl-build-system
5999 This variable is exported by @code{(guix build-system perl)}. It
6000 implements the standard build procedure for Perl packages, which either
6001 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6002 followed by @code{Build} and @code{Build install}; or in running
6003 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6004 @code{make} and @code{make install}, depending on which of
6005 @code{Build.PL} or @code{Makefile.PL} is present in the package
6006 distribution. Preference is given to the former if both @code{Build.PL}
6007 and @code{Makefile.PL} exist in the package distribution. This
6008 preference can be reversed by specifying @code{#t} for the
6009 @code{#:make-maker?} parameter.
6011 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6012 passes flags specified by the @code{#:make-maker-flags} or
6013 @code{#:module-build-flags} parameter, respectively.
6015 Which Perl package is used can be specified with @code{#:perl}.
6018 @defvr {Scheme Variable} r-build-system
6019 This variable is exported by @code{(guix build-system r)}. It
6020 implements the build procedure used by @uref{http://r-project.org, R}
6021 packages, which essentially is little more than running @code{R CMD
6022 INSTALL --library=/gnu/store/@dots{}} in an environment where
6023 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6024 are run after installation using the R function
6025 @code{tools::testInstalledPackage}.
6028 @defvr {Scheme Variable} rakudo-build-system
6029 This variable is exported by @code{(guix build-system rakudo)} It
6030 implements the build procedure used by @uref{https://rakudo.org/,
6031 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6032 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6033 installs the binaries, library files and the resources, as well as wrap
6034 the files under the @code{bin/} directory. Tests can be skipped by
6035 passing @code{#f} to the @code{tests?} parameter.
6037 Which rakudo package is used can be specified with @code{rakudo}.
6038 Which perl6-tap-harness package used for the tests can be specified with
6039 @code{#:prove6} or removed by passing @code{#f} to the
6040 @code{with-prove6?} parameter.
6041 Which perl6-zef package used for tests and installing can be specified
6042 with @code{#:zef} or removed by passing @code{#f} to the
6043 @code{with-zef?} parameter.
6046 @defvr {Scheme Variable} texlive-build-system
6047 This variable is exported by @code{(guix build-system texlive)}. It is
6048 used to build TeX packages in batch mode with a specified engine. The
6049 build system sets the @code{TEXINPUTS} variable to find all TeX source
6050 files in the inputs.
6052 By default it runs @code{luatex} on all files ending on @code{ins}. A
6053 different engine and format can be specified with the
6054 @code{#:tex-format} argument. Different build targets can be specified
6055 with the @code{#:build-targets} argument, which expects a list of file
6056 names. The build system adds only @code{texlive-bin} and
6057 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6058 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6059 and @code{#:texlive-latex-base}, respectively.
6061 The @code{#:tex-directory} parameter tells the build system where to
6062 install the built files under the texmf tree.
6065 @defvr {Scheme Variable} ruby-build-system
6066 This variable is exported by @code{(guix build-system ruby)}. It
6067 implements the RubyGems build procedure used by Ruby packages, which
6068 involves running @code{gem build} followed by @code{gem install}.
6070 The @code{source} field of a package that uses this build system
6071 typically references a gem archive, since this is the format that Ruby
6072 developers use when releasing their software. The build system unpacks
6073 the gem archive, potentially patches the source, runs the test suite,
6074 repackages the gem, and installs it. Additionally, directories and
6075 tarballs may be referenced to allow building unreleased gems from Git or
6076 a traditional source release tarball.
6078 Which Ruby package is used can be specified with the @code{#:ruby}
6079 parameter. A list of additional flags to be passed to the @command{gem}
6080 command can be specified with the @code{#:gem-flags} parameter.
6083 @defvr {Scheme Variable} waf-build-system
6084 This variable is exported by @code{(guix build-system waf)}. It
6085 implements a build procedure around the @code{waf} script. The common
6086 phases---@code{configure}, @code{build}, and @code{install}---are
6087 implemented by passing their names as arguments to the @code{waf}
6090 The @code{waf} script is executed by the Python interpreter. Which
6091 Python package is used to run the script can be specified with the
6092 @code{#:python} parameter.
6095 @defvr {Scheme Variable} scons-build-system
6096 This variable is exported by @code{(guix build-system scons)}. It
6097 implements the build procedure used by the SCons software construction
6098 tool. This build system runs @code{scons} to build the package,
6099 @code{scons test} to run tests, and then @code{scons install} to install
6102 Additional flags to be passed to @code{scons} can be specified with the
6103 @code{#:scons-flags} parameter. The version of Python used to run SCons
6104 can be specified by selecting the appropriate SCons package with the
6105 @code{#:scons} parameter.
6108 @defvr {Scheme Variable} haskell-build-system
6109 This variable is exported by @code{(guix build-system haskell)}. It
6110 implements the Cabal build procedure used by Haskell packages, which
6111 involves running @code{runhaskell Setup.hs configure
6112 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6113 Instead of installing the package by running @code{runhaskell Setup.hs
6114 install}, to avoid trying to register libraries in the read-only
6115 compiler store directory, the build system uses @code{runhaskell
6116 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6117 addition, the build system generates the package documentation by
6118 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6119 is passed. Optional Haddock parameters can be passed with the help of
6120 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6121 not found, the build system looks for @code{Setup.lhs} instead.
6123 Which Haskell compiler is used can be specified with the @code{#:haskell}
6124 parameter which defaults to @code{ghc}.
6127 @defvr {Scheme Variable} dub-build-system
6128 This variable is exported by @code{(guix build-system dub)}. It
6129 implements the Dub build procedure used by D packages, which
6130 involves running @code{dub build} and @code{dub run}.
6131 Installation is done by copying the files manually.
6133 Which D compiler is used can be specified with the @code{#:ldc}
6134 parameter which defaults to @code{ldc}.
6137 @defvr {Scheme Variable} emacs-build-system
6138 This variable is exported by @code{(guix build-system emacs)}. It
6139 implements an installation procedure similar to the packaging system
6140 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6142 It first creates the @code{@var{package}-autoloads.el} file, then it
6143 byte compiles all Emacs Lisp files. Differently from the Emacs
6144 packaging system, the Info documentation files are moved to the standard
6145 documentation directory and the @file{dir} file is deleted. Each
6146 package is installed in its own directory under
6147 @file{share/emacs/site-lisp/guix.d}.
6150 @defvr {Scheme Variable} font-build-system
6151 This variable is exported by @code{(guix build-system font)}. It
6152 implements an installation procedure for font packages where upstream
6153 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6154 need to be copied into place. It copies font files to standard
6155 locations in the output directory.
6158 @defvr {Scheme Variable} meson-build-system
6159 This variable is exported by @code{(guix build-system meson)}. It
6160 implements the build procedure for packages that use
6161 @url{http://mesonbuild.com, Meson} as their build system.
6163 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6164 of inputs, and they can be changed with the parameters @code{#:meson}
6165 and @code{#:ninja} if needed. The default Meson is
6166 @code{meson-for-build}, which is special because it doesn't clear the
6167 @code{RUNPATH} of binaries and libraries when they are installed.
6169 This build system is an extension of @var{gnu-build-system}, but with the
6170 following phases changed to some specific for Meson:
6175 The phase runs @code{meson} with the flags specified in
6176 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6177 @code{plain} unless something else is specified in @code{#:build-type}.
6180 The phase runs @code{ninja} to build the package in parallel by default, but
6181 this can be changed with @code{#:parallel-build?}.
6184 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6185 which is @code{"test"} by default.
6188 The phase runs @code{ninja install} and can not be changed.
6191 Apart from that, the build system also adds the following phases:
6196 This phase ensures that all binaries can find the libraries they need.
6197 It searches for required libraries in subdirectories of the package being
6198 built, and adds those to @code{RUNPATH} where needed. It also removes
6199 references to libraries left over from the build phase by
6200 @code{meson-for-build}, such as test dependencies, that aren't actually
6201 required for the program to run.
6203 @item glib-or-gtk-wrap
6204 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6205 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6207 @item glib-or-gtk-compile-schemas
6208 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6209 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6213 Lastly, for packages that do not need anything as sophisticated, a
6214 ``trivial'' build system is provided. It is trivial in the sense that
6215 it provides basically no support: it does not pull any implicit inputs,
6216 and does not have a notion of build phases.
6218 @defvr {Scheme Variable} trivial-build-system
6219 This variable is exported by @code{(guix build-system trivial)}.
6221 This build system requires a @code{#:builder} argument. This argument
6222 must be a Scheme expression that builds the package output(s)---as
6223 with @code{build-expression->derivation} (@pxref{Derivations,
6224 @code{build-expression->derivation}}).
6234 Conceptually, the @dfn{store} is the place where derivations that have
6235 been built successfully are stored---by default, @file{/gnu/store}.
6236 Sub-directories in the store are referred to as @dfn{store items} or
6237 sometimes @dfn{store paths}. The store has an associated database that
6238 contains information such as the store paths referred to by each store
6239 path, and the list of @emph{valid} store items---results of successful
6240 builds. This database resides in @file{@var{localstatedir}/guix/db},
6241 where @var{localstatedir} is the state directory specified @i{via}
6242 @option{--localstatedir} at configure time, usually @file{/var}.
6244 The store is @emph{always} accessed by the daemon on behalf of its clients
6245 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6246 connect to the daemon over a Unix-domain socket, send requests to it,
6247 and read the result---these are remote procedure calls, or RPCs.
6250 Users must @emph{never} modify files under @file{/gnu/store} directly.
6251 This would lead to inconsistencies and break the immutability
6252 assumptions of Guix's functional model (@pxref{Introduction}).
6254 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6255 how to check the integrity of the store and attempt recovery from
6256 accidental modifications.
6259 The @code{(guix store)} module provides procedures to connect to the
6260 daemon, and to perform RPCs. These are described below. By default,
6261 @code{open-connection}, and thus all the @command{guix} commands,
6262 connect to the local daemon or to the URI specified by the
6263 @code{GUIX_DAEMON_SOCKET} environment variable.
6265 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6266 When set, the value of this variable should be a file name or a URI
6267 designating the daemon endpoint. When it is a file name, it denotes a
6268 Unix-domain socket to connect to. In addition to file names, the
6269 supported URI schemes are:
6274 These are for Unix-domain sockets.
6275 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6276 @file{/var/guix/daemon-socket/socket}.
6279 @cindex daemon, remote access
6280 @cindex remote access to the daemon
6281 @cindex daemon, cluster setup
6282 @cindex clusters, daemon setup
6283 These URIs denote connections over TCP/IP, without encryption nor
6284 authentication of the remote host. The URI must specify the host name
6285 and optionally a port number (by default port 44146 is used):
6288 guix://master.guix.example.org:1234
6291 This setup is suitable on local networks, such as clusters, where only
6292 trusted nodes may connect to the build daemon at
6293 @code{master.guix.example.org}.
6295 The @code{--listen} option of @command{guix-daemon} can be used to
6296 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6300 @cindex SSH access to build daemons
6301 These URIs allow you to connect to a remote daemon over
6302 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
6303 A typical URL might look like this:
6306 ssh://charlie@@guix.example.org:22
6309 As for @command{guix copy}, the usual OpenSSH client configuration files
6310 are honored (@pxref{Invoking guix copy}).
6313 Additional URI schemes may be supported in the future.
6315 @c XXX: Remove this note when the protocol incurs fewer round trips
6316 @c and when (guix derivations) no longer relies on file system access.
6318 The ability to connect to remote build daemons is considered
6319 experimental as of @value{VERSION}. Please get in touch with us to
6320 share any problems or suggestions you may have (@pxref{Contributing}).
6324 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6325 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6326 @var{reserve-space?} is true, instruct it to reserve a little bit of
6327 extra space on the file system so that the garbage collector can still
6328 operate should the disk become full. Return a server object.
6330 @var{file} defaults to @var{%default-socket-path}, which is the normal
6331 location given the options that were passed to @command{configure}.
6334 @deffn {Scheme Procedure} close-connection @var{server}
6335 Close the connection to @var{server}.
6338 @defvr {Scheme Variable} current-build-output-port
6339 This variable is bound to a SRFI-39 parameter, which refers to the port
6340 where build and error logs sent by the daemon should be written.
6343 Procedures that make RPCs all take a server object as their first
6346 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6347 @cindex invalid store items
6348 Return @code{#t} when @var{path} designates a valid store item and
6349 @code{#f} otherwise (an invalid item may exist on disk but still be
6350 invalid, for instance because it is the result of an aborted or failed
6353 A @code{&store-protocol-error} condition is raised if @var{path} is not
6354 prefixed by the store directory (@file{/gnu/store}).
6357 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6358 Add @var{text} under file @var{name} in the store, and return its store
6359 path. @var{references} is the list of store paths referred to by the
6360 resulting store path.
6363 @deffn {Scheme Procedure} build-derivations @var{server} @var{derivations}
6364 Build @var{derivations} (a list of @code{<derivation>} objects or
6365 derivation paths), and return when the worker is done building them.
6366 Return @code{#t} on success.
6369 Note that the @code{(guix monads)} module provides a monad as well as
6370 monadic versions of the above procedures, with the goal of making it
6371 more convenient to work with code that accesses the store (@pxref{The
6375 @i{This section is currently incomplete.}
6378 @section Derivations
6381 Low-level build actions and the environment in which they are performed
6382 are represented by @dfn{derivations}. A derivation contains the
6383 following pieces of information:
6387 The outputs of the derivation---derivations produce at least one file or
6388 directory in the store, but may produce more.
6391 @cindex build-time dependencies
6392 @cindex dependencies, build-time
6393 The inputs of the derivations---i.e., its build-time dependencies---which may
6394 be other derivations or plain files in the store (patches, build scripts,
6398 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
6401 The file name of a build script in the store, along with the arguments
6405 A list of environment variables to be defined.
6409 @cindex derivation path
6410 Derivations allow clients of the daemon to communicate build actions to
6411 the store. They exist in two forms: as an in-memory representation,
6412 both on the client- and daemon-side, and as files in the store whose
6413 name end in @code{.drv}---these files are referred to as @dfn{derivation
6414 paths}. Derivations paths can be passed to the @code{build-derivations}
6415 procedure to perform the build actions they prescribe (@pxref{The
6418 @cindex fixed-output derivations
6419 Operations such as file downloads and version-control checkouts for
6420 which the expected content hash is known in advance are modeled as
6421 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
6422 of a fixed-output derivation are independent of its inputs---e.g., a
6423 source code download produces the same result regardless of the download
6424 method and tools being used.
6427 @cindex run-time dependencies
6428 @cindex dependencies, run-time
6429 The outputs of derivations---i.e., the build results---have a set of
6430 @dfn{references}, as reported by the @code{references} RPC or the
6431 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
6432 are the set of run-time dependencies of the build results. References are a
6433 subset of the inputs of the derivation; this subset is automatically computed
6434 by the build daemon by scanning all the files in the outputs.
6436 The @code{(guix derivations)} module provides a representation of
6437 derivations as Scheme objects, along with procedures to create and
6438 otherwise manipulate derivations. The lowest-level primitive to create
6439 a derivation is the @code{derivation} procedure:
6441 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
6442 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6443 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
6444 [#:system (%current-system)] [#:references-graphs #f] @
6445 [#:allowed-references #f] [#:disallowed-references #f] @
6446 [#:leaked-env-vars #f] [#:local-build? #f] @
6447 [#:substitutable? #t] [#:properties '()]
6448 Build a derivation with the given arguments, and return the resulting
6449 @code{<derivation>} object.
6451 When @var{hash} and @var{hash-algo} are given, a
6452 @dfn{fixed-output derivation} is created---i.e., one whose result is
6453 known in advance, such as a file download. If, in addition,
6454 @var{recursive?} is true, then that fixed output may be an executable
6455 file or a directory and @var{hash} must be the hash of an archive
6456 containing this output.
6458 When @var{references-graphs} is true, it must be a list of file
6459 name/store path pairs. In that case, the reference graph of each store
6460 path is exported in the build environment in the corresponding file, in
6461 a simple text format.
6463 When @var{allowed-references} is true, it must be a list of store items
6464 or outputs that the derivation's output may refer to. Likewise,
6465 @var{disallowed-references}, if true, must be a list of things the
6466 outputs may @emph{not} refer to.
6468 When @var{leaked-env-vars} is true, it must be a list of strings
6469 denoting environment variables that are allowed to ``leak'' from the
6470 daemon's environment to the build environment. This is only applicable
6471 to fixed-output derivations---i.e., when @var{hash} is true. The main
6472 use is to allow variables such as @code{http_proxy} to be passed to
6473 derivations that download files.
6475 When @var{local-build?} is true, declare that the derivation is not a
6476 good candidate for offloading and should rather be built locally
6477 (@pxref{Daemon Offload Setup}). This is the case for small derivations
6478 where the costs of data transfers would outweigh the benefits.
6480 When @var{substitutable?} is false, declare that substitutes of the
6481 derivation's output should not be used (@pxref{Substitutes}). This is
6482 useful, for instance, when building packages that capture details of the
6483 host CPU instruction set.
6485 @var{properties} must be an association list describing ``properties'' of the
6486 derivation. It is kept as-is, uninterpreted, in the derivation.
6490 Here's an example with a shell script as its builder, assuming
6491 @var{store} is an open connection to the daemon, and @var{bash} points
6492 to a Bash executable in the store:
6495 (use-modules (guix utils)
6499 (let ((builder ; add the Bash script to the store
6500 (add-text-to-store store "my-builder.sh"
6501 "echo hello world > $out\n" '())))
6502 (derivation store "foo"
6503 bash `("-e" ,builder)
6504 #:inputs `((,bash) (,builder))
6505 #:env-vars '(("HOME" . "/homeless"))))
6506 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
6509 As can be guessed, this primitive is cumbersome to use directly. A
6510 better approach is to write build scripts in Scheme, of course! The
6511 best course of action for that is to write the build code as a
6512 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
6513 information, @pxref{G-Expressions}.
6515 Once upon a time, @code{gexp->derivation} did not exist and constructing
6516 derivations with build code written in Scheme was achieved with
6517 @code{build-expression->derivation}, documented below. This procedure
6518 is now deprecated in favor of the much nicer @code{gexp->derivation}.
6520 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
6521 @var{name} @var{exp} @
6522 [#:system (%current-system)] [#:inputs '()] @
6523 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6524 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
6525 [#:references-graphs #f] [#:allowed-references #f] @
6526 [#:disallowed-references #f] @
6527 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
6528 Return a derivation that executes Scheme expression @var{exp} as a
6529 builder for derivation @var{name}. @var{inputs} must be a list of
6530 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
6531 @code{"out"} is assumed. @var{modules} is a list of names of Guile
6532 modules from the current search path to be copied in the store,
6533 compiled, and made available in the load path during the execution of
6534 @var{exp}---e.g., @code{((guix build utils) (guix build
6535 gnu-build-system))}.
6537 @var{exp} is evaluated in an environment where @code{%outputs} is bound
6538 to a list of output/path pairs, and where @code{%build-inputs} is bound
6539 to a list of string/output-path pairs made from @var{inputs}.
6540 Optionally, @var{env-vars} is a list of string pairs specifying the name
6541 and value of environment variables visible to the builder. The builder
6542 terminates by passing the result of @var{exp} to @code{exit}; thus, when
6543 @var{exp} returns @code{#f}, the build is considered to have failed.
6545 @var{exp} is built using @var{guile-for-build} (a derivation). When
6546 @var{guile-for-build} is omitted or is @code{#f}, the value of the
6547 @code{%guile-for-build} fluid is used instead.
6549 See the @code{derivation} procedure for the meaning of
6550 @var{references-graphs}, @var{allowed-references},
6551 @var{disallowed-references}, @var{local-build?}, and
6552 @var{substitutable?}.
6556 Here's an example of a single-output derivation that creates a directory
6557 containing one file:
6560 (let ((builder '(let ((out (assoc-ref %outputs "out")))
6561 (mkdir out) ; create /gnu/store/@dots{}-goo
6562 (call-with-output-file (string-append out "/test")
6564 (display '(hello guix) p))))))
6565 (build-expression->derivation store "goo" builder))
6567 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
6571 @node The Store Monad
6572 @section The Store Monad
6576 The procedures that operate on the store described in the previous
6577 sections all take an open connection to the build daemon as their first
6578 argument. Although the underlying model is functional, they either have
6579 side effects or depend on the current state of the store.
6581 The former is inconvenient: the connection to the build daemon has to be
6582 carried around in all those functions, making it impossible to compose
6583 functions that do not take that parameter with functions that do. The
6584 latter can be problematic: since store operations have side effects
6585 and/or depend on external state, they have to be properly sequenced.
6587 @cindex monadic values
6588 @cindex monadic functions
6589 This is where the @code{(guix monads)} module comes in. This module
6590 provides a framework for working with @dfn{monads}, and a particularly
6591 useful monad for our uses, the @dfn{store monad}. Monads are a
6592 construct that allows two things: associating ``context'' with values
6593 (in our case, the context is the store), and building sequences of
6594 computations (here computations include accesses to the store). Values
6595 in a monad---values that carry this additional context---are called
6596 @dfn{monadic values}; procedures that return such values are called
6597 @dfn{monadic procedures}.
6599 Consider this ``normal'' procedure:
6602 (define (sh-symlink store)
6603 ;; Return a derivation that symlinks the 'bash' executable.
6604 (let* ((drv (package-derivation store bash))
6605 (out (derivation->output-path drv))
6606 (sh (string-append out "/bin/bash")))
6607 (build-expression->derivation store "sh"
6608 `(symlink ,sh %output))))
6611 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
6612 as a monadic function:
6615 (define (sh-symlink)
6616 ;; Same, but return a monadic value.
6617 (mlet %store-monad ((drv (package->derivation bash)))
6618 (gexp->derivation "sh"
6619 #~(symlink (string-append #$drv "/bin/bash")
6623 There are several things to note in the second version: the @code{store}
6624 parameter is now implicit and is ``threaded'' in the calls to the
6625 @code{package->derivation} and @code{gexp->derivation} monadic
6626 procedures, and the monadic value returned by @code{package->derivation}
6627 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
6629 As it turns out, the call to @code{package->derivation} can even be
6630 omitted since it will take place implicitly, as we will see later
6631 (@pxref{G-Expressions}):
6634 (define (sh-symlink)
6635 (gexp->derivation "sh"
6636 #~(symlink (string-append #$bash "/bin/bash")
6641 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
6642 @c for the funny quote.
6643 Calling the monadic @code{sh-symlink} has no effect. As someone once
6644 said, ``you exit a monad like you exit a building on fire: by running''.
6645 So, to exit the monad and get the desired effect, one must use
6646 @code{run-with-store}:
6649 (run-with-store (open-connection) (sh-symlink))
6650 @result{} /gnu/store/...-sh-symlink
6653 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
6654 new ``meta-commands'' to make it easier to deal with monadic procedures:
6655 @code{run-in-store}, and @code{enter-store-monad}. The former is used
6656 to ``run'' a single monadic value through the store:
6659 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
6660 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6663 The latter enters a recursive REPL, where all the return values are
6664 automatically run through the store:
6667 scheme@@(guile-user)> ,enter-store-monad
6668 store-monad@@(guile-user) [1]> (package->derivation hello)
6669 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6670 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
6671 $3 = "/gnu/store/@dots{}-foo"
6672 store-monad@@(guile-user) [1]> ,q
6673 scheme@@(guile-user)>
6677 Note that non-monadic values cannot be returned in the
6678 @code{store-monad} REPL.
6680 The main syntactic forms to deal with monads in general are provided by
6681 the @code{(guix monads)} module and are described below.
6683 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
6684 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
6688 @deffn {Scheme Syntax} return @var{val}
6689 Return a monadic value that encapsulates @var{val}.
6692 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
6693 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
6694 procedures @var{mproc}@dots{}@footnote{This operation is commonly
6695 referred to as ``bind'', but that name denotes an unrelated procedure in
6696 Guile. Thus we use this somewhat cryptic symbol inherited from the
6697 Haskell language.}. There can be one @var{mproc} or several of them, as
6702 (with-monad %state-monad
6704 (lambda (x) (return (+ 1 x)))
6705 (lambda (x) (return (* 2 x)))))
6709 @result{} some-state
6713 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
6715 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
6717 Bind the variables @var{var} to the monadic values @var{mval} in
6718 @var{body}, which is a sequence of expressions. As with the bind
6719 operator, this can be thought of as ``unpacking'' the raw, non-monadic
6720 value ``contained'' in @var{mval} and making @var{var} refer to that
6721 raw, non-monadic value within the scope of the @var{body}. The form
6722 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
6723 @var{val}, as per @code{let}. The binding operations occur in sequence
6724 from left to right. The last expression of @var{body} must be a monadic
6725 expression, and its result will become the result of the @code{mlet} or
6726 @code{mlet*} when run in the @var{monad}.
6728 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
6729 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
6732 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
6733 Bind @var{mexp} and the following monadic expressions in sequence,
6734 returning the result of the last expression. Every expression in the
6735 sequence must be a monadic expression.
6737 This is akin to @code{mlet}, except that the return values of the
6738 monadic expressions are ignored. In that sense, it is analogous to
6739 @code{begin}, but applied to monadic expressions.
6742 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
6743 When @var{condition} is true, evaluate the sequence of monadic
6744 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6745 @var{condition} is false, return @code{*unspecified*} in the current
6746 monad. Every expression in the sequence must be a monadic expression.
6749 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
6750 When @var{condition} is false, evaluate the sequence of monadic
6751 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6752 @var{condition} is true, return @code{*unspecified*} in the current
6753 monad. Every expression in the sequence must be a monadic expression.
6757 The @code{(guix monads)} module provides the @dfn{state monad}, which
6758 allows an additional value---the state---to be @emph{threaded} through
6759 monadic procedure calls.
6761 @defvr {Scheme Variable} %state-monad
6762 The state monad. Procedures in the state monad can access and change
6763 the state that is threaded.
6765 Consider the example below. The @code{square} procedure returns a value
6766 in the state monad. It returns the square of its argument, but also
6767 increments the current state value:
6771 (mlet %state-monad ((count (current-state)))
6772 (mbegin %state-monad
6773 (set-current-state (+ 1 count))
6776 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
6781 When ``run'' through @var{%state-monad}, we obtain that additional state
6782 value, which is the number of @code{square} calls.
6785 @deffn {Monadic Procedure} current-state
6786 Return the current state as a monadic value.
6789 @deffn {Monadic Procedure} set-current-state @var{value}
6790 Set the current state to @var{value} and return the previous state as a
6794 @deffn {Monadic Procedure} state-push @var{value}
6795 Push @var{value} to the current state, which is assumed to be a list,
6796 and return the previous state as a monadic value.
6799 @deffn {Monadic Procedure} state-pop
6800 Pop a value from the current state and return it as a monadic value.
6801 The state is assumed to be a list.
6804 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
6805 Run monadic value @var{mval} starting with @var{state} as the initial
6806 state. Return two values: the resulting value, and the resulting state.
6809 The main interface to the store monad, provided by the @code{(guix
6810 store)} module, is as follows.
6812 @defvr {Scheme Variable} %store-monad
6813 The store monad---an alias for @var{%state-monad}.
6815 Values in the store monad encapsulate accesses to the store. When its
6816 effect is needed, a value of the store monad must be ``evaluated'' by
6817 passing it to the @code{run-with-store} procedure (see below.)
6820 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
6821 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
6822 open store connection.
6825 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
6826 Return as a monadic value the absolute file name in the store of the file
6827 containing @var{text}, a string. @var{references} is a list of store items that the
6828 resulting text file refers to; it defaults to the empty list.
6831 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
6832 Return as a monadic value the absolute file name in the store of the file
6833 containing @var{data}, a bytevector. @var{references} is a list of store
6834 items that the resulting binary file refers to; it defaults to the empty list.
6837 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
6838 [#:recursive? #t] [#:select? (const #t)]
6839 Return the name of @var{file} once interned in the store. Use
6840 @var{name} as its store name, or the basename of @var{file} if
6841 @var{name} is omitted.
6843 When @var{recursive?} is true, the contents of @var{file} are added
6844 recursively; if @var{file} designates a flat file and @var{recursive?}
6845 is true, its contents are added, and its permission bits are kept.
6847 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
6848 @var{stat})} for each directory entry, where @var{file} is the entry's
6849 absolute file name and @var{stat} is the result of @code{lstat}; exclude
6850 entries for which @var{select?} does not return true.
6852 The example below adds a file to the store, under two different names:
6855 (run-with-store (open-connection)
6856 (mlet %store-monad ((a (interned-file "README"))
6857 (b (interned-file "README" "LEGU-MIN")))
6858 (return (list a b))))
6860 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
6865 The @code{(guix packages)} module exports the following package-related
6868 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
6869 [#:system (%current-system)] [#:target #f] @
6872 value in the absolute file name of @var{file} within the @var{output}
6873 directory of @var{package}. When @var{file} is omitted, return the name
6874 of the @var{output} directory of @var{package}. When @var{target} is
6875 true, use it as a cross-compilation target triplet.
6878 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
6879 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
6880 @var{target} [@var{system}]
6881 Monadic version of @code{package-derivation} and
6882 @code{package-cross-derivation} (@pxref{Defining Packages}).
6887 @section G-Expressions
6889 @cindex G-expression
6890 @cindex build code quoting
6891 So we have ``derivations'', which represent a sequence of build actions
6892 to be performed to produce an item in the store (@pxref{Derivations}).
6893 These build actions are performed when asking the daemon to actually
6894 build the derivations; they are run by the daemon in a container
6895 (@pxref{Invoking guix-daemon}).
6897 @cindex strata of code
6898 It should come as no surprise that we like to write these build actions
6899 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
6900 code@footnote{The term @dfn{stratum} in this context was coined by
6901 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
6902 Kiselyov, who has written insightful
6903 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
6904 on this topic}, refers to this kind of code generation as
6905 @dfn{staging}.}: the ``host code''---code that defines packages, talks
6906 to the daemon, etc.---and the ``build code''---code that actually
6907 performs build actions, such as making directories, invoking
6908 @command{make}, etc.
6910 To describe a derivation and its build actions, one typically needs to
6911 embed build code inside host code. It boils down to manipulating build
6912 code as data, and the homoiconicity of Scheme---code has a direct
6913 representation as data---comes in handy for that. But we need more than
6914 the normal @code{quasiquote} mechanism in Scheme to construct build
6917 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
6918 S-expressions adapted to build expressions. G-expressions, or
6919 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
6920 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
6921 @code{#$}, and @code{#$@@}), which are comparable to
6922 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
6923 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
6924 GNU Guile Reference Manual}). However, there are major differences:
6928 Gexps are meant to be written to a file and run or manipulated by other
6932 When a high-level object such as a package or derivation is unquoted
6933 inside a gexp, the result is as if its output file name had been
6937 Gexps carry information about the packages or derivations they refer to,
6938 and these dependencies are automatically added as inputs to the build
6939 processes that use them.
6942 @cindex lowering, of high-level objects in gexps
6943 This mechanism is not limited to package and derivation
6944 objects: @dfn{compilers} able to ``lower'' other high-level objects to
6945 derivations or files in the store can be defined,
6946 such that these objects can also be inserted
6947 into gexps. For example, a useful type of high-level objects that can be
6948 inserted in a gexp is ``file-like objects'', which make it easy to
6949 add files to the store and to refer to them in
6950 derivations and such (see @code{local-file} and @code{plain-file}
6953 To illustrate the idea, here is an example of a gexp:
6960 (symlink (string-append #$coreutils "/bin/ls")
6964 This gexp can be passed to @code{gexp->derivation}; we obtain a
6965 derivation that builds a directory containing exactly one symlink to
6966 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
6969 (gexp->derivation "the-thing" build-exp)
6972 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
6973 substituted to the reference to the @var{coreutils} package in the
6974 actual build code, and @var{coreutils} is automatically made an input to
6975 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
6976 output)}) is replaced by a string containing the directory name of the
6977 output of the derivation.
6979 @cindex cross compilation
6980 In a cross-compilation context, it is useful to distinguish between
6981 references to the @emph{native} build of a package---that can run on the
6982 host---versus references to cross builds of a package. To that end, the
6983 @code{#+} plays the same role as @code{#$}, but is a reference to a
6984 native package build:
6987 (gexp->derivation "vi"
6990 (system* (string-append #+coreutils "/bin/ln")
6992 (string-append #$emacs "/bin/emacs")
6993 (string-append #$output "/bin/vi")))
6994 #:target "mips64el-linux-gnu")
6998 In the example above, the native build of @var{coreutils} is used, so
6999 that @command{ln} can actually run on the host; but then the
7000 cross-compiled build of @var{emacs} is referenced.
7002 @cindex imported modules, for gexps
7003 @findex with-imported-modules
7004 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7005 able to use certain Guile modules from the ``host environment'' in the
7006 gexp, so those modules should be imported in the ``build environment''.
7007 The @code{with-imported-modules} form allows you to express that:
7010 (let ((build (with-imported-modules '((guix build utils))
7012 (use-modules (guix build utils))
7013 (mkdir-p (string-append #$output "/bin"))))))
7014 (gexp->derivation "empty-dir"
7017 (display "success!\n")
7022 In this example, the @code{(guix build utils)} module is automatically
7023 pulled into the isolated build environment of our gexp, such that
7024 @code{(use-modules (guix build utils))} works as expected.
7026 @cindex module closure
7027 @findex source-module-closure
7028 Usually you want the @emph{closure} of the module to be imported---i.e.,
7029 the module itself and all the modules it depends on---rather than just
7030 the module; failing to do that, attempts to use the module will fail
7031 because of missing dependent modules. The @code{source-module-closure}
7032 procedure computes the closure of a module by looking at its source file
7033 headers, which comes in handy in this case:
7036 (use-modules (guix modules)) ;for 'source-module-closure'
7038 (with-imported-modules (source-module-closure
7039 '((guix build utils)
7041 (gexp->derivation "something-with-vms"
7043 (use-modules (guix build utils)
7048 @cindex extensions, for gexps
7049 @findex with-extensions
7050 In the same vein, sometimes you want to import not just pure-Scheme
7051 modules, but also ``extensions'' such as Guile bindings to C libraries
7052 or other ``full-blown'' packages. Say you need the @code{guile-json}
7053 package available on the build side, here's how you would do it:
7056 (use-modules (gnu packages guile)) ;for 'guile-json'
7058 (with-extensions (list guile-json)
7059 (gexp->derivation "something-with-json"
7061 (use-modules (json))
7065 The syntactic form to construct gexps is summarized below.
7067 @deffn {Scheme Syntax} #~@var{exp}
7068 @deffnx {Scheme Syntax} (gexp @var{exp})
7069 Return a G-expression containing @var{exp}. @var{exp} may contain one
7070 or more of the following forms:
7074 @itemx (ungexp @var{obj})
7075 Introduce a reference to @var{obj}. @var{obj} may have one of the
7076 supported types, for example a package or a
7077 derivation, in which case the @code{ungexp} form is replaced by its
7078 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7080 If @var{obj} is a list, it is traversed and references to supported
7081 objects are substituted similarly.
7083 If @var{obj} is another gexp, its contents are inserted and its
7084 dependencies are added to those of the containing gexp.
7086 If @var{obj} is another kind of object, it is inserted as is.
7088 @item #$@var{obj}:@var{output}
7089 @itemx (ungexp @var{obj} @var{output})
7090 This is like the form above, but referring explicitly to the
7091 @var{output} of @var{obj}---this is useful when @var{obj} produces
7092 multiple outputs (@pxref{Packages with Multiple Outputs}).
7095 @itemx #+@var{obj}:output
7096 @itemx (ungexp-native @var{obj})
7097 @itemx (ungexp-native @var{obj} @var{output})
7098 Same as @code{ungexp}, but produces a reference to the @emph{native}
7099 build of @var{obj} when used in a cross compilation context.
7101 @item #$output[:@var{output}]
7102 @itemx (ungexp output [@var{output}])
7103 Insert a reference to derivation output @var{output}, or to the main
7104 output when @var{output} is omitted.
7106 This only makes sense for gexps passed to @code{gexp->derivation}.
7109 @itemx (ungexp-splicing @var{lst})
7110 Like the above, but splices the contents of @var{lst} inside the
7114 @itemx (ungexp-native-splicing @var{lst})
7115 Like the above, but refers to native builds of the objects listed in
7120 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7121 of the @code{gexp?} type (see below.)
7124 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7125 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7126 in their execution environment.
7128 Each item in @var{modules} can be the name of a module, such as
7129 @code{(guix build utils)}, or it can be a module name, followed by an
7130 arrow, followed by a file-like object:
7133 `((guix build utils)
7135 ((guix config) => ,(scheme-file "config.scm"
7136 #~(define-module @dots{}))))
7140 In the example above, the first two modules are taken from the search
7141 path, and the last one is created from the given file-like object.
7143 This form has @emph{lexical} scope: it has an effect on the gexps
7144 directly defined in @var{body}@dots{}, but not on those defined, say, in
7145 procedures called from @var{body}@dots{}.
7148 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7149 Mark the gexps defined in @var{body}@dots{} as requiring
7150 @var{extensions} in their build and execution environment.
7151 @var{extensions} is typically a list of package objects such as those
7152 defined in the @code{(gnu packages guile)} module.
7154 Concretely, the packages listed in @var{extensions} are added to the
7155 load path while compiling imported modules in @var{body}@dots{}; they
7156 are also added to the load path of the gexp returned by
7160 @deffn {Scheme Procedure} gexp? @var{obj}
7161 Return @code{#t} if @var{obj} is a G-expression.
7164 G-expressions are meant to be written to disk, either as code building
7165 some derivation, or as plain files in the store. The monadic procedures
7166 below allow you to do that (@pxref{The Store Monad}, for more
7167 information about monads.)
7169 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7170 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7171 [#:hash #f] [#:hash-algo #f] @
7172 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7173 [#:module-path @var{%load-path}] @
7174 [#:effective-version "2.2"] @
7175 [#:references-graphs #f] [#:allowed-references #f] @
7176 [#:disallowed-references #f] @
7177 [#:leaked-env-vars #f] @
7178 [#:script-name (string-append @var{name} "-builder")] @
7179 [#:deprecation-warnings #f] @
7180 [#:local-build? #f] [#:substitutable? #t] @
7181 [#:properties '()] [#:guile-for-build #f]
7182 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7183 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7184 stored in a file called @var{script-name}. When @var{target} is true,
7185 it is used as the cross-compilation target triplet for packages referred
7188 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7190 make @var{modules} available in the evaluation context of @var{exp};
7191 @var{modules} is a list of names of Guile modules searched in
7192 @var{module-path} to be copied in the store, compiled, and made available in
7193 the load path during the execution of @var{exp}---e.g., @code{((guix
7194 build utils) (guix build gnu-build-system))}.
7196 @var{effective-version} determines the string to use when adding extensions of
7197 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7199 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7202 When @var{references-graphs} is true, it must be a list of tuples of one of the
7206 (@var{file-name} @var{package})
7207 (@var{file-name} @var{package} @var{output})
7208 (@var{file-name} @var{derivation})
7209 (@var{file-name} @var{derivation} @var{output})
7210 (@var{file-name} @var{store-item})
7213 The right-hand-side of each element of @var{references-graphs} is automatically made
7214 an input of the build process of @var{exp}. In the build environment, each
7215 @var{file-name} contains the reference graph of the corresponding item, in a simple
7218 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7219 In the latter case, the list denotes store items that the result is allowed to
7220 refer to. Any reference to another store item will lead to a build error.
7221 Similarly for @var{disallowed-references}, which can list items that must not be
7222 referenced by the outputs.
7224 @var{deprecation-warnings} determines whether to show deprecation warnings while
7225 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7227 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7230 @cindex file-like objects
7231 The @code{local-file}, @code{plain-file}, @code{computed-file},
7232 @code{program-file}, and @code{scheme-file} procedures below return
7233 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7234 these objects lead to a file in the store. Consider this G-expression:
7237 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7238 #$(local-file "/tmp/my-nscd.conf"))
7241 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7242 to the store. Once expanded, for instance @i{via}
7243 @code{gexp->derivation}, the G-expression refers to that copy under
7244 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7245 does not have any effect on what the G-expression does.
7246 @code{plain-file} can be used similarly; it differs in that the file
7247 content is directly passed as a string.
7249 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7250 [#:recursive? #f] [#:select? (const #t)]
7251 Return an object representing local file @var{file} to add to the store; this
7252 object can be used in a gexp. If @var{file} is a relative file name, it is looked
7253 up relative to the source file where this form appears. @var{file} will be added to
7254 the store under @var{name}--by default the base name of @var{file}.
7256 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7257 designates a flat file and @var{recursive?} is true, its contents are added, and its
7258 permission bits are kept.
7260 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7261 @var{stat})} for each directory entry, where @var{file} is the entry's
7262 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7263 entries for which @var{select?} does not return true.
7265 This is the declarative counterpart of the @code{interned-file} monadic
7266 procedure (@pxref{The Store Monad, @code{interned-file}}).
7269 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7270 Return an object representing a text file called @var{name} with the given
7271 @var{content} (a string or a bytevector) to be added to the store.
7273 This is the declarative counterpart of @code{text-file}.
7276 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7277 [#:options '(#:local-build? #t)]
7278 Return an object representing the store item @var{name}, a file or
7279 directory computed by @var{gexp}. @var{options}
7280 is a list of additional arguments to pass to @code{gexp->derivation}.
7282 This is the declarative counterpart of @code{gexp->derivation}.
7285 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7286 [#:guile (default-guile)] [#:module-path %load-path]
7287 Return an executable script @var{name} that runs @var{exp} using
7288 @var{guile}, with @var{exp}'s imported modules in its search path.
7289 Look up @var{exp}'s modules in @var{module-path}.
7291 The example below builds a script that simply invokes the @command{ls}
7295 (use-modules (guix gexp) (gnu packages base))
7297 (gexp->script "list-files"
7298 #~(execl #$(file-append coreutils "/bin/ls")
7302 When ``running'' it through the store (@pxref{The Store Monad,
7303 @code{run-with-store}}), we obtain a derivation that produces an
7304 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7307 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7309 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7313 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7314 [#:guile #f] [#:module-path %load-path]
7315 Return an object representing the executable store item @var{name} that
7316 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7317 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7319 This is the declarative counterpart of @code{gexp->script}.
7322 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7323 [#:set-load-path? #t] [#:module-path %load-path] @
7325 [#:guile (default-guile)]
7326 Return a derivation that builds a file @var{name} containing @var{exp}.
7327 When @var{splice?} is true, @var{exp} is considered to be a list of
7328 expressions that will be spliced in the resulting file.
7330 When @var{set-load-path?} is true, emit code in the resulting file to
7331 set @code{%load-path} and @code{%load-compiled-path} to honor
7332 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7335 The resulting file holds references to all the dependencies of @var{exp}
7336 or a subset thereof.
7339 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
7340 Return an object representing the Scheme file @var{name} that contains
7343 This is the declarative counterpart of @code{gexp->file}.
7346 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7347 Return as a monadic value a derivation that builds a text file
7348 containing all of @var{text}. @var{text} may list, in addition to
7349 strings, objects of any type that can be used in a gexp: packages,
7350 derivations, local file objects, etc. The resulting store file holds
7351 references to all these.
7353 This variant should be preferred over @code{text-file} anytime the file
7354 to create will reference items from the store. This is typically the
7355 case when building a configuration file that embeds store file names,
7359 (define (profile.sh)
7360 ;; Return the name of a shell script in the store that
7361 ;; initializes the 'PATH' environment variable.
7362 (text-file* "profile.sh"
7363 "export PATH=" coreutils "/bin:"
7364 grep "/bin:" sed "/bin\n"))
7367 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
7368 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
7369 preventing them from being garbage-collected during its lifetime.
7372 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
7373 Return an object representing store file @var{name} containing
7374 @var{text}. @var{text} is a sequence of strings and file-like objects,
7378 (mixed-text-file "profile"
7379 "export PATH=" coreutils "/bin:" grep "/bin")
7382 This is the declarative counterpart of @code{text-file*}.
7385 @deffn {Scheme Procedure} file-union @var{name} @var{files}
7386 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
7387 Each item in @var{files} must be a two-element list where the first element is the
7388 file name to use in the new directory, and the second element is a gexp
7389 denoting the target file. Here's an example:
7393 `(("hosts" ,(plain-file "hosts"
7394 "127.0.0.1 localhost"))
7395 ("bashrc" ,(plain-file "bashrc"
7396 "alias ls='ls --color=auto'"))))
7399 This yields an @code{etc} directory containing these two files.
7402 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
7403 Return a directory that is the union of @var{things}, where @var{things} is a list of
7404 file-like objects denoting directories. For example:
7407 (directory-union "guile+emacs" (list guile emacs))
7410 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
7413 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
7414 Return a file-like object that expands to the concatenation of @var{obj}
7415 and @var{suffix}, where @var{obj} is a lowerable object and each
7416 @var{suffix} is a string.
7418 As an example, consider this gexp:
7421 (gexp->script "run-uname"
7422 #~(system* #$(file-append coreutils
7426 The same effect could be achieved with:
7429 (gexp->script "run-uname"
7430 #~(system* (string-append #$coreutils
7434 There is one difference though: in the @code{file-append} case, the
7435 resulting script contains the absolute file name as a string, whereas in
7436 the second case, the resulting script contains a @code{(string-append
7437 @dots{})} expression to construct the file name @emph{at run time}.
7441 Of course, in addition to gexps embedded in ``host'' code, there are
7442 also modules containing build tools. To make it clear that they are
7443 meant to be used in the build stratum, these modules are kept in the
7444 @code{(guix build @dots{})} name space.
7446 @cindex lowering, of high-level objects in gexps
7447 Internally, high-level objects are @dfn{lowered}, using their compiler,
7448 to either derivations or store items. For instance, lowering a package
7449 yields a derivation, and lowering a @code{plain-file} yields a store
7450 item. This is achieved using the @code{lower-object} monadic procedure.
7452 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
7454 Return as a value in @var{%store-monad} the derivation or store item
7455 corresponding to @var{obj} for @var{system}, cross-compiling for
7456 @var{target} if @var{target} is true. @var{obj} must be an object that
7457 has an associated gexp compiler, such as a @code{<package>}.
7460 @node Invoking guix repl
7461 @section Invoking @command{guix repl}
7463 @cindex REPL, read-eval-print loop
7464 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
7465 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
7466 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
7467 command, @command{guix repl} guarantees that all the Guix modules and all its
7468 dependencies are available in the search path. You can use it this way:
7472 scheme@@(guile-user)> ,use (gnu packages base)
7473 scheme@@(guile-user)> coreutils
7474 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
7478 In addition, @command{guix repl} implements a simple machine-readable REPL
7479 protocol for use by @code{(guix inferior)}, a facility to interact with
7480 @dfn{inferiors}, separate processes running a potentially different revision
7483 The available options are as follows:
7486 @item --type=@var{type}
7487 @itemx -t @var{type}
7488 Start a REPL of the given @var{TYPE}, which can be one of the following:
7492 This is default, and it spawns a standard full-featured Guile REPL.
7494 Spawn a REPL that uses the machine-readable protocol. This is the protocol
7495 that the @code{(guix inferior)} module speaks.
7498 @item --listen=@var{endpoint}
7499 By default, @command{guix repl} reads from standard input and writes to
7500 standard output. When this option is passed, it will instead listen for
7501 connections on @var{endpoint}. Here are examples of valid options:
7504 @item --listen=tcp:37146
7505 Accept connections on localhost on port 37146.
7507 @item --listen=unix:/tmp/socket
7508 Accept connections on the Unix-domain socket @file{/tmp/socket}.
7512 @c *********************************************************************
7516 This section describes Guix command-line utilities. Some of them are
7517 primarily targeted at developers and users who write new package
7518 definitions, while others are more generally useful. They complement
7519 the Scheme programming interface of Guix in a convenient way.
7522 * Invoking guix build:: Building packages from the command line.
7523 * Invoking guix edit:: Editing package definitions.
7524 * Invoking guix download:: Downloading a file and printing its hash.
7525 * Invoking guix hash:: Computing the cryptographic hash of a file.
7526 * Invoking guix import:: Importing package definitions.
7527 * Invoking guix refresh:: Updating package definitions.
7528 * Invoking guix lint:: Finding errors in package definitions.
7529 * Invoking guix size:: Profiling disk usage.
7530 * Invoking guix graph:: Visualizing the graph of packages.
7531 * Invoking guix publish:: Sharing substitutes.
7532 * Invoking guix challenge:: Challenging substitute servers.
7533 * Invoking guix copy:: Copying to and from a remote store.
7534 * Invoking guix container:: Process isolation.
7535 * Invoking guix weather:: Assessing substitute availability.
7536 * Invoking guix processes:: Listing client processes.
7539 @node Invoking guix build
7540 @section Invoking @command{guix build}
7542 @cindex package building
7543 @cindex @command{guix build}
7544 The @command{guix build} command builds packages or derivations and
7545 their dependencies, and prints the resulting store paths. Note that it
7546 does not modify the user's profile---this is the job of the
7547 @command{guix package} command (@pxref{Invoking guix package}). Thus,
7548 it is mainly useful for distribution developers.
7550 The general syntax is:
7553 guix build @var{options} @var{package-or-derivation}@dots{}
7556 As an example, the following command builds the latest versions of Emacs
7557 and of Guile, displays their build logs, and finally displays the
7558 resulting directories:
7561 guix build emacs guile
7564 Similarly, the following command builds all the available packages:
7567 guix build --quiet --keep-going \
7568 `guix package -A | cut -f1,2 --output-delimiter=@@`
7571 @var{package-or-derivation} may be either the name of a package found in
7572 the software distribution such as @code{coreutils} or
7573 @code{coreutils@@8.20}, or a derivation such as
7574 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
7575 package with the corresponding name (and optionally version) is searched
7576 for among the GNU distribution modules (@pxref{Package Modules}).
7578 Alternatively, the @code{--expression} option may be used to specify a
7579 Scheme expression that evaluates to a package; this is useful when
7580 disambiguating among several same-named packages or package variants is
7583 There may be zero or more @var{options}. The available options are
7584 described in the subsections below.
7587 * Common Build Options:: Build options for most commands.
7588 * Package Transformation Options:: Creating variants of packages.
7589 * Additional Build Options:: Options specific to 'guix build'.
7590 * Debugging Build Failures:: Real life packaging experience.
7593 @node Common Build Options
7594 @subsection Common Build Options
7596 A number of options that control the build process are common to
7597 @command{guix build} and other commands that can spawn builds, such as
7598 @command{guix package} or @command{guix archive}. These are the
7603 @item --load-path=@var{directory}
7604 @itemx -L @var{directory}
7605 Add @var{directory} to the front of the package module search path
7606 (@pxref{Package Modules}).
7608 This allows users to define their own packages and make them visible to
7609 the command-line tools.
7613 Keep the build tree of failed builds. Thus, if a build fails, its build
7614 tree is kept under @file{/tmp}, in a directory whose name is shown at
7615 the end of the build log. This is useful when debugging build issues.
7616 @xref{Debugging Build Failures}, for tips and tricks on how to debug
7619 This option has no effect when connecting to a remote daemon with a
7620 @code{guix://} URI (@pxref{The Store, the @code{GUIX_DAEMON_SOCKET}
7625 Keep going when some of the derivations fail to build; return only once
7626 all the builds have either completed or failed.
7628 The default behavior is to stop as soon as one of the specified
7629 derivations has failed.
7633 Do not build the derivations.
7635 @anchor{fallback-option}
7637 When substituting a pre-built binary fails, fall back to building
7638 packages locally (@pxref{Substitution Failure}).
7640 @item --substitute-urls=@var{urls}
7641 @anchor{client-substitute-urls}
7642 Consider @var{urls} the whitespace-separated list of substitute source
7643 URLs, overriding the default list of URLs of @command{guix-daemon}
7644 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
7646 This means that substitutes may be downloaded from @var{urls}, provided
7647 they are signed by a key authorized by the system administrator
7648 (@pxref{Substitutes}).
7650 When @var{urls} is the empty string, substitutes are effectively
7653 @item --no-substitutes
7654 Do not use substitutes for build products. That is, always build things
7655 locally instead of allowing downloads of pre-built binaries
7656 (@pxref{Substitutes}).
7659 Do not ``graft'' packages. In practice, this means that package updates
7660 available as grafts are not applied. @xref{Security Updates}, for more
7661 information on grafts.
7663 @item --rounds=@var{n}
7664 Build each derivation @var{n} times in a row, and raise an error if
7665 consecutive build results are not bit-for-bit identical.
7667 This is a useful way to detect non-deterministic builds processes.
7668 Non-deterministic build processes are a problem because they make it
7669 practically impossible for users to @emph{verify} whether third-party
7670 binaries are genuine. @xref{Invoking guix challenge}, for more.
7672 Note that, currently, the differing build results are not kept around,
7673 so you will have to manually investigate in case of an error---e.g., by
7674 stashing one of the build results with @code{guix archive --export}
7675 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
7678 @item --no-build-hook
7679 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
7680 (@pxref{Daemon Offload Setup}). That is, always build things locally
7681 instead of offloading builds to remote machines.
7683 @item --max-silent-time=@var{seconds}
7684 When the build or substitution process remains silent for more than
7685 @var{seconds}, terminate it and report a build failure.
7687 By default, the daemon's setting is honored (@pxref{Invoking
7688 guix-daemon, @code{--max-silent-time}}).
7690 @item --timeout=@var{seconds}
7691 Likewise, when the build or substitution process lasts for more than
7692 @var{seconds}, terminate it and report a build failure.
7694 By default, the daemon's setting is honored (@pxref{Invoking
7695 guix-daemon, @code{--timeout}}).
7697 @c Note: This option is actually not part of %standard-build-options but
7698 @c most programs honor it.
7699 @cindex verbosity, of the command-line tools
7700 @cindex build logs, verbosity
7701 @item -v @var{level}
7702 @itemx --verbosity=@var{level}
7703 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
7704 output is produced, 1 is for quiet output, and 2 shows all the build log
7705 output on standard error.
7707 @item --cores=@var{n}
7709 Allow the use of up to @var{n} CPU cores for the build. The special
7710 value @code{0} means to use as many CPU cores as available.
7712 @item --max-jobs=@var{n}
7714 Allow at most @var{n} build jobs in parallel. @xref{Invoking
7715 guix-daemon, @code{--max-jobs}}, for details about this option and the
7716 equivalent @command{guix-daemon} option.
7718 @item --debug=@var{level}
7719 Produce debugging output coming from the build daemon. @var{level} must be an
7720 integer between 0 and 5; higher means more verbose output. Setting a level of
7721 4 or more may be helpful when debugging setup issues with the build daemon.
7725 Behind the scenes, @command{guix build} is essentially an interface to
7726 the @code{package-derivation} procedure of the @code{(guix packages)}
7727 module, and to the @code{build-derivations} procedure of the @code{(guix
7728 derivations)} module.
7730 In addition to options explicitly passed on the command line,
7731 @command{guix build} and other @command{guix} commands that support
7732 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
7734 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
7735 Users can define this variable to a list of command line options that
7736 will automatically be used by @command{guix build} and other
7737 @command{guix} commands that can perform builds, as in the example
7741 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
7744 These options are parsed independently, and the result is appended to
7745 the parsed command-line options.
7749 @node Package Transformation Options
7750 @subsection Package Transformation Options
7752 @cindex package variants
7753 Another set of command-line options supported by @command{guix build}
7754 and also @command{guix package} are @dfn{package transformation
7755 options}. These are options that make it possible to define @dfn{package
7756 variants}---for instance, packages built from different source code.
7757 This is a convenient way to create customized packages on the fly
7758 without having to type in the definitions of package variants
7759 (@pxref{Defining Packages}).
7763 @item --with-source=@var{source}
7764 @itemx --with-source=@var{package}=@var{source}
7765 @itemx --with-source=@var{package}@@@var{version}=@var{source}
7766 Use @var{source} as the source of @var{package}, and @var{version} as
7768 @var{source} must be a file name or a URL, as for @command{guix
7769 download} (@pxref{Invoking guix download}).
7771 When @var{package} is omitted,
7772 it is taken to be the package name specified on the
7773 command line that matches the base of @var{source}---e.g.,
7774 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
7775 package is @code{guile}.
7777 Likewise, when @var{version} is omitted, the version string is inferred from
7778 @var{source}; in the previous example, it is @code{2.0.10}.
7780 This option allows users to try out versions of packages other than the
7781 one provided by the distribution. The example below downloads
7782 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
7783 the @code{ed} package:
7786 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
7789 As a developer, @code{--with-source} makes it easy to test release
7793 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
7796 @dots{} or to build from a checkout in a pristine environment:
7799 $ git clone git://git.sv.gnu.org/guix.git
7800 $ guix build guix --with-source=guix@@1.0=./guix
7803 @item --with-input=@var{package}=@var{replacement}
7804 Replace dependency on @var{package} by a dependency on
7805 @var{replacement}. @var{package} must be a package name, and
7806 @var{replacement} must be a package specification such as @code{guile}
7807 or @code{guile@@1.8}.
7809 For instance, the following command builds Guix, but replaces its
7810 dependency on the current stable version of Guile with a dependency on
7811 the legacy version of Guile, @code{guile@@2.0}:
7814 guix build --with-input=guile=guile@@2.0 guix
7817 This is a recursive, deep replacement. So in this example, both
7818 @code{guix} and its dependency @code{guile-json} (which also depends on
7819 @code{guile}) get rebuilt against @code{guile@@2.0}.
7821 This is implemented using the @code{package-input-rewriting} Scheme
7822 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
7824 @item --with-graft=@var{package}=@var{replacement}
7825 This is similar to @code{--with-input} but with an important difference:
7826 instead of rebuilding the whole dependency chain, @var{replacement} is
7827 built and then @dfn{grafted} onto the binaries that were initially
7828 referring to @var{package}. @xref{Security Updates}, for more
7829 information on grafts.
7831 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
7832 and all its dependencies, replacing references to the version of GnuTLS
7833 they currently refer to:
7836 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
7839 This has the advantage of being much faster than rebuilding everything.
7840 But there is a caveat: it works if and only if @var{package} and
7841 @var{replacement} are strictly compatible---for example, if they provide
7842 a library, the application binary interface (ABI) of those libraries
7843 must be compatible. If @var{replacement} is somehow incompatible with
7844 @var{package}, then the resulting package may be unusable. Use with
7847 @item --with-git-url=@var{package}=@var{url}
7848 @cindex Git, using the latest commit
7849 @cindex latest commit, building
7850 Build @var{package} from the latest commit of the @code{master} branch of the
7851 Git repository at @var{url}. Git sub-modules of the repository are fetched,
7854 For example, the following command builds the NumPy Python library against the
7855 latest commit of the master branch of Python itself:
7858 guix build python-numpy \
7859 --with-git-url=python=https://github.com/python/cpython
7862 This option can also be combined with @code{--with-branch} or
7863 @code{--with-commit} (see below).
7865 @cindex continuous integration
7866 Obviously, since it uses the latest commit of the given branch, the result of
7867 such a command varies over time. Nevertheless it is a convenient way to
7868 rebuild entire software stacks against the latest commit of one or more
7869 packages. This is particularly useful in the context of continuous
7872 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
7873 consecutive accesses to the same repository. You may want to clean it up once
7874 in a while to save disk space.
7876 @item --with-branch=@var{package}=@var{branch}
7877 Build @var{package} from the latest commit of @var{branch}. If the
7878 @code{source} field of @var{package} is an origin with the @code{git-fetch}
7879 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
7880 repository URL is taken from that @code{source}. Otherwise you have to use
7881 @code{--with-git-url} to specify the URL of the Git repository.
7883 For instance, the following command builds @code{guile-sqlite3} from the
7884 latest commit of its @code{master} branch, and then builds @code{guix} (which
7885 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
7886 specific @code{guile-sqlite3} build:
7889 guix build --with-branch=guile-sqlite3=master cuirass
7892 @item --with-commit=@var{package}=@var{commit}
7893 This is similar to @code{--with-branch}, except that it builds from
7894 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
7895 Git commit SHA1 identifier.
7898 @node Additional Build Options
7899 @subsection Additional Build Options
7901 The command-line options presented below are specific to @command{guix
7908 Build quietly, without displaying the build log; this is equivalent to
7909 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
7910 (or similar) and can always be retrieved using the @option{--log-file} option.
7912 @item --file=@var{file}
7913 @itemx -f @var{file}
7914 Build the package, derivation, or other file-like object that the code within
7915 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
7917 As an example, @var{file} might contain a package definition like this
7918 (@pxref{Defining Packages}):
7921 @verbatiminclude package-hello.scm
7924 @item --expression=@var{expr}
7925 @itemx -e @var{expr}
7926 Build the package or derivation @var{expr} evaluates to.
7928 For example, @var{expr} may be @code{(@@ (gnu packages guile)
7929 guile-1.8)}, which unambiguously designates this specific variant of
7930 version 1.8 of Guile.
7932 Alternatively, @var{expr} may be a G-expression, in which case it is used
7933 as a build program passed to @code{gexp->derivation}
7934 (@pxref{G-Expressions}).
7936 Lastly, @var{expr} may refer to a zero-argument monadic procedure
7937 (@pxref{The Store Monad}). The procedure must return a derivation as a
7938 monadic value, which is then passed through @code{run-with-store}.
7942 Build the source derivations of the packages, rather than the packages
7945 For instance, @code{guix build -S gcc} returns something like
7946 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
7949 The returned source tarball is the result of applying any patches and
7950 code snippets specified in the package @code{origin} (@pxref{Defining
7954 Fetch and return the source of @var{package-or-derivation} and all their
7955 dependencies, recursively. This is a handy way to obtain a local copy
7956 of all the source code needed to build @var{packages}, allowing you to
7957 eventually build them even without network access. It is an extension
7958 of the @code{--source} option and can accept one of the following
7959 optional argument values:
7963 This value causes the @code{--sources} option to behave in the same way
7964 as the @code{--source} option.
7967 Build the source derivations of all packages, including any source that
7968 might be listed as @code{inputs}. This is the default value.
7971 $ guix build --sources tzdata
7972 The following derivations will be built:
7973 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
7974 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
7978 Build the source derivations of all packages, as well of all transitive
7979 inputs to the packages. This can be used e.g.@: to
7980 prefetch package source for later offline building.
7983 $ guix build --sources=transitive tzdata
7984 The following derivations will be built:
7985 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
7986 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
7987 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
7988 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
7989 /gnu/store/@dots{}-make-4.1.tar.xz.drv
7990 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
7996 @item --system=@var{system}
7997 @itemx -s @var{system}
7998 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
7999 the system type of the build host.
8002 The @code{--system} flag is for @emph{native} compilation and must not
8003 be confused with cross-compilation. See @code{--target} below for
8004 information on cross-compilation.
8007 An example use of this is on Linux-based systems, which can emulate
8008 different personalities. For instance, passing
8009 @code{--system=i686-linux} on an @code{x86_64-linux} system or
8010 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
8011 to build packages in a complete 32-bit environment.
8014 Building for an @code{armhf-linux} system is unconditionally enabled on
8015 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8016 allow for this functionality, notably the ThunderX.
8019 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8020 is enabled (@pxref{Virtualization Services,
8021 @code{qemu-binfmt-service-type}}), you can build for any system for
8022 which a QEMU @code{binfmt_misc} handler is installed.
8024 Builds for a system other than that of the machine you are using can
8025 also be offloaded to a remote machine of the right architecture.
8026 @xref{Daemon Offload Setup}, for more information on offloading.
8028 @item --target=@var{triplet}
8029 @cindex cross-compilation
8030 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8031 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
8032 configuration triplets,, autoconf, Autoconf}).
8034 @anchor{build-check}
8036 @cindex determinism, checking
8037 @cindex reproducibility, checking
8038 Rebuild @var{package-or-derivation}, which are already available in the
8039 store, and raise an error if the build results are not bit-for-bit
8042 This mechanism allows you to check whether previously installed
8043 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8044 of a package is deterministic. @xref{Invoking guix challenge}, for more
8045 background information and tools.
8047 When used in conjunction with @option{--keep-failed}, the differing
8048 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8049 This makes it easy to look for differences between the two results.
8052 @cindex repairing store items
8053 @cindex corruption, recovering from
8054 Attempt to repair the specified store items, if they are corrupt, by
8055 re-downloading or rebuilding them.
8057 This operation is not atomic and thus restricted to @code{root}.
8061 Return the derivation paths, not the output paths, of the given
8064 @item --root=@var{file}
8065 @itemx -r @var{file}
8066 @cindex GC roots, adding
8067 @cindex garbage collector roots, adding
8068 Make @var{file} a symlink to the result, and register it as a garbage
8071 Consequently, the results of this @command{guix build} invocation are
8072 protected from garbage collection until @var{file} is removed. When
8073 that option is omitted, build results are eligible for garbage
8074 collection as soon as the build completes. @xref{Invoking guix gc}, for
8078 @cindex build logs, access
8079 Return the build log file names or URLs for the given
8080 @var{package-or-derivation}, or raise an error if build logs are
8083 This works regardless of how packages or derivations are specified. For
8084 instance, the following invocations are equivalent:
8087 guix build --log-file `guix build -d guile`
8088 guix build --log-file `guix build guile`
8089 guix build --log-file guile
8090 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8093 If a log is unavailable locally, and unless @code{--no-substitutes} is
8094 passed, the command looks for a corresponding log on one of the
8095 substitute servers (as specified with @code{--substitute-urls}.)
8097 So for instance, imagine you want to see the build log of GDB on MIPS,
8098 but you are actually on an @code{x86_64} machine:
8101 $ guix build --log-file gdb -s mips64el-linux
8102 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8105 You can freely access a huge library of build logs!
8108 @node Debugging Build Failures
8109 @subsection Debugging Build Failures
8111 @cindex build failures, debugging
8112 When defining a new package (@pxref{Defining Packages}), you will
8113 probably find yourself spending some time debugging and tweaking the
8114 build until it succeeds. To do that, you need to operate the build
8115 commands yourself in an environment as close as possible to the one the
8118 To that end, the first thing to do is to use the @option{--keep-failed}
8119 or @option{-K} option of @command{guix build}, which will keep the
8120 failed build tree in @file{/tmp} or whatever directory you specified as
8121 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8123 From there on, you can @command{cd} to the failed build tree and source
8124 the @file{environment-variables} file, which contains all the
8125 environment variable definitions that were in place when the build
8126 failed. So let's say you're debugging a build failure in package
8127 @code{foo}; a typical session would look like this:
8131 @dots{} @i{build fails}
8132 $ cd /tmp/guix-build-foo.drv-0
8133 $ source ./environment-variables
8137 Now, you can invoke commands as if you were the daemon (almost) and
8138 troubleshoot your build process.
8140 Sometimes it happens that, for example, a package's tests pass when you
8141 run them manually but they fail when the daemon runs them. This can
8142 happen because the daemon runs builds in containers where, unlike in our
8143 environment above, network access is missing, @file{/bin/sh} does not
8144 exist, etc. (@pxref{Build Environment Setup}).
8146 In such cases, you may need to run inspect the build process from within
8147 a container similar to the one the build daemon creates:
8152 $ cd /tmp/guix-build-foo.drv-0
8153 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8154 [env]# source ./environment-variables
8158 Here, @command{guix environment -C} creates a container and spawns a new
8159 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8160 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8161 the container, which would may find handy while debugging. The
8162 @option{--no-grafts} option makes sure we get the exact same
8163 environment, with ungrafted packages (@pxref{Security Updates}, for more
8166 To get closer to a container like that used by the build daemon, we can
8167 remove @file{/bin/sh}:
8173 (Don't worry, this is harmless: this is all happening in the throw-away
8174 container created by @command{guix environment}.)
8176 The @command{strace} command is probably not in the search path, but we
8180 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8183 In this way, not only you will have reproduced the environment variables
8184 the daemon uses, you will also be running the build process in a container
8185 similar to the one the daemon uses.
8188 @node Invoking guix edit
8189 @section Invoking @command{guix edit}
8191 @cindex @command{guix edit}
8192 @cindex package definition, editing
8193 So many packages, so many source files! The @command{guix edit} command
8194 facilitates the life of users and packagers by pointing their editor at
8195 the source file containing the definition of the specified packages.
8199 guix edit gcc@@4.9 vim
8203 launches the program specified in the @code{VISUAL} or in the
8204 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8207 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8208 have created your own packages on @code{GUIX_PACKAGE_PATH}
8209 (@pxref{Package Modules}), you will be able to edit the package
8210 recipes. In other cases, you will be able to examine the read-only recipes
8211 for packages currently in the store.
8214 @node Invoking guix download
8215 @section Invoking @command{guix download}
8217 @cindex @command{guix download}
8218 @cindex downloading package sources
8219 When writing a package definition, developers typically need to download
8220 a source tarball, compute its SHA256 hash, and write that
8221 hash in the package definition (@pxref{Defining Packages}). The
8222 @command{guix download} tool helps with this task: it downloads a file
8223 from the given URI, adds it to the store, and prints both its file name
8224 in the store and its SHA256 hash.
8226 The fact that the downloaded file is added to the store saves bandwidth:
8227 when the developer eventually tries to build the newly defined package
8228 with @command{guix build}, the source tarball will not have to be
8229 downloaded again because it is already in the store. It is also a
8230 convenient way to temporarily stash files, which may be deleted
8231 eventually (@pxref{Invoking guix gc}).
8233 The @command{guix download} command supports the same URIs as used in
8234 package definitions. In particular, it supports @code{mirror://} URIs.
8235 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8236 Guile bindings for GnuTLS are available in the user's environment; when
8237 they are not available, an error is raised. @xref{Guile Preparations,
8238 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8239 GnuTLS-Guile}, for more information.
8241 @command{guix download} verifies HTTPS server certificates by loading
8242 the certificates of X.509 authorities from the directory pointed to by
8243 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8244 Certificates}), unless @option{--no-check-certificate} is used.
8246 The following options are available:
8249 @item --format=@var{fmt}
8251 Write the hash in the format specified by @var{fmt}. For more
8252 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8254 @item --no-check-certificate
8255 Do not validate the X.509 certificates of HTTPS servers.
8257 When using this option, you have @emph{absolutely no guarantee} that you
8258 are communicating with the authentic server responsible for the given
8259 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8261 @item --output=@var{file}
8262 @itemx -o @var{file}
8263 Save the downloaded file to @var{file} instead of adding it to the
8267 @node Invoking guix hash
8268 @section Invoking @command{guix hash}
8270 @cindex @command{guix hash}
8271 The @command{guix hash} command computes the SHA256 hash of a file.
8272 It is primarily a convenience tool for anyone contributing to the
8273 distribution: it computes the cryptographic hash of a file, which can be
8274 used in the definition of a package (@pxref{Defining Packages}).
8276 The general syntax is:
8279 guix hash @var{option} @var{file}
8282 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8283 hash of data read from standard input. @command{guix hash} has the
8288 @item --format=@var{fmt}
8290 Write the hash in the format specified by @var{fmt}.
8292 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8293 (@code{hex} and @code{hexadecimal} can be used as well).
8295 If the @option{--format} option is not specified, @command{guix hash}
8296 will output the hash in @code{nix-base32}. This representation is used
8297 in the definitions of packages.
8301 Compute the hash on @var{file} recursively.
8303 In this case, the hash is computed on an archive containing @var{file},
8304 including its children if it is a directory. Some of the metadata of
8305 @var{file} is part of the archive; for instance, when @var{file} is a
8306 regular file, the hash is different depending on whether @var{file} is
8307 executable or not. Metadata such as time stamps has no impact on the
8308 hash (@pxref{Invoking guix archive}).
8309 @c FIXME: Replace xref above with xref to an ``Archive'' section when
8314 When combined with @option{--recursive}, exclude version control system
8315 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
8318 As an example, here is how you would compute the hash of a Git checkout,
8319 which is useful when using the @code{git-fetch} method (@pxref{origin
8323 $ git clone http://example.org/foo.git
8329 @node Invoking guix import
8330 @section Invoking @command{guix import}
8332 @cindex importing packages
8333 @cindex package import
8334 @cindex package conversion
8335 @cindex Invoking @command{guix import}
8336 The @command{guix import} command is useful for people who would like to
8337 add a package to the distribution with as little work as
8338 possible---a legitimate demand. The command knows of a few
8339 repositories from which it can ``import'' package metadata. The result
8340 is a package definition, or a template thereof, in the format we know
8341 (@pxref{Defining Packages}).
8343 The general syntax is:
8346 guix import @var{importer} @var{options}@dots{}
8349 @var{importer} specifies the source from which to import package
8350 metadata, and @var{options} specifies a package identifier and other
8351 options specific to @var{importer}. Currently, the available
8356 Import metadata for the given GNU package. This provides a template
8357 for the latest version of that GNU package, including the hash of its
8358 source tarball, and its canonical synopsis and description.
8360 Additional information such as the package dependencies and its
8361 license needs to be figured out manually.
8363 For example, the following command returns a package definition for
8367 guix import gnu hello
8370 Specific command-line options are:
8373 @item --key-download=@var{policy}
8374 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
8375 keys when verifying the package signature. @xref{Invoking guix
8376 refresh, @code{--key-download}}.
8381 Import metadata from the @uref{https://pypi.python.org/, Python Package
8382 Index}. Information is taken from the JSON-formatted description
8383 available at @code{pypi.python.org} and usually includes all the relevant
8384 information, including package dependencies. For maximum efficiency, it
8385 is recommended to install the @command{unzip} utility, so that the
8386 importer can unzip Python wheels and gather data from them.
8388 The command below imports metadata for the @code{itsdangerous} Python
8392 guix import pypi itsdangerous
8398 Traverse the dependency graph of the given upstream package recursively
8399 and generate package expressions for all those packages that are not yet
8405 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
8406 is taken from the JSON-formatted description available at
8407 @code{rubygems.org} and includes most relevant information, including
8408 runtime dependencies. There are some caveats, however. The metadata
8409 doesn't distinguish between synopses and descriptions, so the same string
8410 is used for both fields. Additionally, the details of non-Ruby
8411 dependencies required to build native extensions is unavailable and left
8412 as an exercise to the packager.
8414 The command below imports metadata for the @code{rails} Ruby package:
8417 guix import gem rails
8423 Traverse the dependency graph of the given upstream package recursively
8424 and generate package expressions for all those packages that are not yet
8430 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
8431 Information is taken from the JSON-formatted metadata provided through
8432 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
8433 relevant information, such as module dependencies. License information
8434 should be checked closely. If Perl is available in the store, then the
8435 @code{corelist} utility will be used to filter core modules out of the
8436 list of dependencies.
8438 The command command below imports metadata for the @code{Acme::Boolean}
8442 guix import cpan Acme::Boolean
8447 @cindex Bioconductor
8448 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
8449 central repository for the @uref{http://r-project.org, GNU@tie{}R
8450 statistical and graphical environment}.
8452 Information is extracted from the @code{DESCRIPTION} file of the package.
8454 The command command below imports metadata for the @code{Cairo}
8458 guix import cran Cairo
8461 When @code{--recursive} is added, the importer will traverse the
8462 dependency graph of the given upstream package recursively and generate
8463 package expressions for all those packages that are not yet in Guix.
8465 When @code{--archive=bioconductor} is added, metadata is imported from
8466 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
8467 packages for for the analysis and comprehension of high-throughput
8468 genomic data in bioinformatics.
8470 Information is extracted from the @code{DESCRIPTION} file of a package
8471 published on the web interface of the Bioconductor SVN repository.
8473 The command below imports metadata for the @code{GenomicRanges}
8477 guix import cran --archive=bioconductor GenomicRanges
8483 Import metadata from @uref{http://www.ctan.org/, CTAN}, the
8484 comprehensive TeX archive network for TeX packages that are part of the
8485 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
8487 Information about the package is obtained through the XML API provided
8488 by CTAN, while the source code is downloaded from the SVN repository of
8489 the Tex Live project. This is done because the CTAN does not keep
8492 The command command below imports metadata for the @code{fontspec}
8496 guix import texlive fontspec
8499 When @code{--archive=DIRECTORY} is added, the source code is downloaded
8500 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
8501 tree in the TeX Live SVN repository, but from the specified sibling
8502 directory under the same root.
8504 The command below imports metadata for the @code{ifxetex} package from
8505 CTAN while fetching the sources from the directory
8506 @file{texmf/source/generic}:
8509 guix import texlive --archive=generic ifxetex
8513 @cindex JSON, import
8514 Import package metadata from a local JSON file. Consider the following
8515 example package definition in JSON format:
8521 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
8522 "build-system": "gnu",
8523 "home-page": "https://www.gnu.org/software/hello/",
8524 "synopsis": "Hello, GNU world: An example GNU package",
8525 "description": "GNU Hello prints a greeting.",
8526 "license": "GPL-3.0+",
8527 "native-inputs": ["gcc@@6"]
8531 The field names are the same as for the @code{<package>} record
8532 (@xref{Defining Packages}). References to other packages are provided
8533 as JSON lists of quoted package specification strings such as
8534 @code{guile} or @code{guile@@2.0}.
8536 The importer also supports a more explicit source definition using the
8537 common fields for @code{<origin>} records:
8543 "method": "url-fetch",
8544 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
8546 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
8553 The command below reads metadata from the JSON file @code{hello.json}
8554 and outputs a package expression:
8557 guix import json hello.json
8561 Import metadata from a local copy of the source of the
8562 @uref{http://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
8563 relies on the @command{nix-instantiate} command of
8564 @uref{http://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
8565 typically written in a mixture of Nix-language and Bash code. This
8566 command only imports the high-level package structure that is written in
8567 the Nix language. It normally includes all the basic fields of a
8570 When importing a GNU package, the synopsis and descriptions are replaced
8571 by their canonical upstream variant.
8573 Usually, you will first need to do:
8576 export NIX_REMOTE=daemon
8580 so that @command{nix-instantiate} does not try to open the Nix database.
8582 As an example, the command below imports the package definition of
8583 LibreOffice (more precisely, it imports the definition of the package
8584 bound to the @code{libreoffice} top-level attribute):
8587 guix import nix ~/path/to/nixpkgs libreoffice
8592 Import metadata from the Haskell community's central package archive
8593 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
8594 Cabal files and includes all the relevant information, including package
8597 Specific command-line options are:
8602 Read a Cabal file from standard input.
8603 @item --no-test-dependencies
8605 Do not include dependencies required only by the test suites.
8606 @item --cabal-environment=@var{alist}
8607 @itemx -e @var{alist}
8608 @var{alist} is a Scheme alist defining the environment in which the
8609 Cabal conditionals are evaluated. The accepted keys are: @code{os},
8610 @code{arch}, @code{impl} and a string representing the name of a flag.
8611 The value associated with a flag has to be either the symbol
8612 @code{true} or @code{false}. The value associated with other keys
8613 has to conform to the Cabal file format definition. The default value
8614 associated with the keys @code{os}, @code{arch} and @code{impl} is
8615 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
8618 Traverse the dependency graph of the given upstream package recursively
8619 and generate package expressions for all those packages that are not yet
8623 The command below imports metadata for the latest version of the
8624 @code{HTTP} Haskell package without including test dependencies and
8625 specifying the value of the flag @samp{network-uri} as @code{false}:
8628 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
8631 A specific package version may optionally be specified by following the
8632 package name by an at-sign and a version number as in the following example:
8635 guix import hackage mtl@@2.1.3.1
8640 The @code{stackage} importer is a wrapper around the @code{hackage} one.
8641 It takes a package name, looks up the package version included in a
8642 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
8643 release and uses the @code{hackage} importer to retrieve its metadata.
8644 Note that it is up to you to select an LTS release compatible with the
8645 GHC compiler used by Guix.
8647 Specific command-line options are:
8650 @item --no-test-dependencies
8652 Do not include dependencies required only by the test suites.
8653 @item --lts-version=@var{version}
8654 @itemx -l @var{version}
8655 @var{version} is the desired LTS release version. If omitted the latest
8659 Traverse the dependency graph of the given upstream package recursively
8660 and generate package expressions for all those packages that are not yet
8664 The command below imports metadata for the @code{HTTP} Haskell package
8665 included in the LTS Stackage release version 7.18:
8668 guix import stackage --lts-version=7.18 HTTP
8673 Import metadata from an Emacs Lisp Package Archive (ELPA) package
8674 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
8676 Specific command-line options are:
8679 @item --archive=@var{repo}
8680 @itemx -a @var{repo}
8681 @var{repo} identifies the archive repository from which to retrieve the
8682 information. Currently the supported repositories and their identifiers
8686 @uref{http://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
8687 identifier. This is the default.
8689 Packages from @code{elpa.gnu.org} are signed with one of the keys
8690 contained in the GnuPG keyring at
8691 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
8692 @code{emacs} package (@pxref{Package Installation, ELPA package
8693 signatures,, emacs, The GNU Emacs Manual}).
8696 @uref{http://stable.melpa.org/packages, MELPA-Stable}, selected by the
8697 @code{melpa-stable} identifier.
8700 @uref{http://melpa.org/packages, MELPA}, selected by the @code{melpa}
8706 Traverse the dependency graph of the given upstream package recursively
8707 and generate package expressions for all those packages that are not yet
8713 Import metadata from the crates.io Rust package repository
8714 @uref{https://crates.io, crates.io}.
8719 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
8720 repository used by the OCaml community.
8723 The structure of the @command{guix import} code is modular. It would be
8724 useful to have more importers for other package formats, and your help
8725 is welcome here (@pxref{Contributing}).
8727 @node Invoking guix refresh
8728 @section Invoking @command{guix refresh}
8730 @cindex @command {guix refresh}
8731 The primary audience of the @command{guix refresh} command is developers
8732 of the GNU software distribution. By default, it reports any packages
8733 provided by the distribution that are outdated compared to the latest
8734 upstream version, like this:
8738 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
8739 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
8742 Alternately, one can specify packages to consider, in which case a
8743 warning is emitted for packages that lack an updater:
8746 $ guix refresh coreutils guile guile-ssh
8747 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
8748 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
8751 @command{guix refresh} browses the upstream repository of each package and determines
8752 the highest version number of the releases therein. The command
8753 knows how to update specific types of packages: GNU packages, ELPA
8754 packages, etc.---see the documentation for @option{--type} below. There
8755 are many packages, though, for which it lacks a method to determine
8756 whether a new upstream release is available. However, the mechanism is
8757 extensible, so feel free to get in touch with us to add a new method!
8762 Consider the packages specified, and all the packages upon which they depend.
8765 $ guix refresh --recursive coreutils
8766 gnu/packages/acl.scm:35:2: warning: no updater for acl
8767 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
8768 gnu/packages/xml.scm:68:2: warning: no updater for expat
8769 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
8775 Sometimes the upstream name differs from the package name used in Guix,
8776 and @command{guix refresh} needs a little help. Most updaters honor the
8777 @code{upstream-name} property in package definitions, which can be used
8781 (define-public network-manager
8783 (name "network-manager")
8785 (properties '((upstream-name . "NetworkManager")))))
8788 When passed @code{--update}, it modifies distribution source files to
8789 update the version numbers and source tarball hashes of those package
8790 recipes (@pxref{Defining Packages}). This is achieved by downloading
8791 each package's latest source tarball and its associated OpenPGP
8792 signature, authenticating the downloaded tarball against its signature
8793 using @command{gpg}, and finally computing its hash. When the public
8794 key used to sign the tarball is missing from the user's keyring, an
8795 attempt is made to automatically retrieve it from a public key server;
8796 when this is successful, the key is added to the user's keyring; otherwise,
8797 @command{guix refresh} reports an error.
8799 The following options are supported:
8803 @item --expression=@var{expr}
8804 @itemx -e @var{expr}
8805 Consider the package @var{expr} evaluates to.
8807 This is useful to precisely refer to a package, as in this example:
8810 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
8813 This command lists the dependents of the ``final'' libc (essentially all
8818 Update distribution source files (package recipes) in place. This is
8819 usually run from a checkout of the Guix source tree (@pxref{Running
8820 Guix Before It Is Installed}):
8823 $ ./pre-inst-env guix refresh -s non-core -u
8826 @xref{Defining Packages}, for more information on package definitions.
8828 @item --select=[@var{subset}]
8829 @itemx -s @var{subset}
8830 Select all the packages in @var{subset}, one of @code{core} or
8833 The @code{core} subset refers to all the packages at the core of the
8834 distribution---i.e., packages that are used to build ``everything
8835 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
8836 changing one of these packages in the distribution entails a rebuild of
8837 all the others. Thus, such updates are an inconvenience to users in
8838 terms of build time or bandwidth used to achieve the upgrade.
8840 The @code{non-core} subset refers to the remaining packages. It is
8841 typically useful in cases where an update of the core packages would be
8844 @item --manifest=@var{file}
8845 @itemx -m @var{file}
8846 Select all the packages from the manifest in @var{file}. This is useful to
8847 check if any packages of the user manifest can be updated.
8849 @item --type=@var{updater}
8850 @itemx -t @var{updater}
8851 Select only packages handled by @var{updater} (may be a comma-separated
8852 list of updaters). Currently, @var{updater} may be one of:
8856 the updater for GNU packages;
8858 the updater for GNOME packages;
8860 the updater for KDE packages;
8862 the updater for X.org packages;
8864 the updater for packages hosted on kernel.org;
8866 the updater for @uref{http://elpa.gnu.org/, ELPA} packages;
8868 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
8870 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
8872 the updater for @uref{http://www.cpan.org/, CPAN} packages;
8874 the updater for @uref{https://pypi.python.org, PyPI} packages.
8876 the updater for @uref{https://rubygems.org, RubyGems} packages.
8878 the updater for @uref{https://github.com, GitHub} packages.
8880 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
8882 the updater for @uref{https://www.stackage.org, Stackage} packages.
8884 the updater for @uref{https://crates.io, Crates} packages.
8886 the updater for @uref{https://launchpad.net, Launchpad} packages.
8889 For instance, the following command only checks for updates of Emacs
8890 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
8893 $ guix refresh --type=elpa,cran
8894 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
8895 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
8900 In addition, @command{guix refresh} can be passed one or more package
8901 names, as in this example:
8904 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
8908 The command above specifically updates the @code{emacs} and
8909 @code{idutils} packages. The @code{--select} option would have no
8910 effect in this case.
8912 When considering whether to upgrade a package, it is sometimes
8913 convenient to know which packages would be affected by the upgrade and
8914 should be checked for compatibility. For this the following option may
8915 be used when passing @command{guix refresh} one or more package names:
8919 @item --list-updaters
8921 List available updaters and exit (see @option{--type} above.)
8923 For each updater, display the fraction of packages it covers; at the
8924 end, display the fraction of packages covered by all these updaters.
8926 @item --list-dependent
8928 List top-level dependent packages that would need to be rebuilt as a
8929 result of upgrading one or more packages.
8931 @xref{Invoking guix graph, the @code{reverse-package} type of
8932 @command{guix graph}}, for information on how to visualize the list of
8933 dependents of a package.
8937 Be aware that the @code{--list-dependent} option only
8938 @emph{approximates} the rebuilds that would be required as a result of
8939 an upgrade. More rebuilds might be required under some circumstances.
8942 $ guix refresh --list-dependent flex
8943 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
8944 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
8947 The command above lists a set of packages that could be built to check
8948 for compatibility with an upgraded @code{flex} package.
8952 @item --list-transitive
8953 List all the packages which one or more packages depend upon.
8956 $ guix refresh --list-transitive flex
8957 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
8958 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{}
8963 The command above lists a set of packages which, when changed, would cause
8964 @code{flex} to be rebuilt.
8966 The following options can be used to customize GnuPG operation:
8970 @item --gpg=@var{command}
8971 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
8972 for in @code{$PATH}.
8974 @item --keyring=@var{file}
8975 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
8976 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
8977 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
8978 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
8979 information on a tool to manipulate keybox files).
8981 When this option is omitted, @command{guix refresh} uses
8982 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
8983 signing keys. OpenPGP signatures are checked against keys from this keyring;
8984 missing keys are downloaded to this keyring as well (see
8985 @option{--key-download} below.)
8987 You can export keys from your default GPG keyring into a keybox file using
8988 commands like this one:
8991 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
8994 Likewise, you can fetch keys to a specific keybox file like this:
8997 gpg --no-default-keyring --keyring mykeyring.kbx \
8998 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9001 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9002 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9004 @item --key-download=@var{policy}
9005 Handle missing OpenPGP keys according to @var{policy}, which may be one
9010 Always download missing OpenPGP keys from the key server, and add them
9011 to the user's GnuPG keyring.
9014 Never try to download missing OpenPGP keys. Instead just bail out.
9017 When a package signed with an unknown OpenPGP key is encountered, ask
9018 the user whether to download it or not. This is the default behavior.
9021 @item --key-server=@var{host}
9022 Use @var{host} as the OpenPGP key server when importing a public key.
9026 The @code{github} updater uses the
9027 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9028 releases. When used repeatedly e.g.@: when refreshing all packages,
9029 GitHub will eventually refuse to answer any further API requests. By
9030 default 60 API requests per hour are allowed, and a full refresh on all
9031 GitHub packages in Guix requires more than this. Authentication with
9032 GitHub through the use of an API token alleviates these limits. To use
9033 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9034 token procured from @uref{https://github.com/settings/tokens} or
9038 @node Invoking guix lint
9039 @section Invoking @command{guix lint}
9041 @cindex @command{guix lint}
9042 @cindex package, checking for errors
9043 The @command{guix lint} command is meant to help package developers avoid
9044 common errors and use a consistent style. It runs a number of checks on
9045 a given set of packages in order to find common mistakes in their
9046 definitions. Available @dfn{checkers} include (see
9047 @code{--list-checkers} for a complete list):
9052 Validate certain typographical and stylistic rules about package
9053 descriptions and synopses.
9055 @item inputs-should-be-native
9056 Identify inputs that should most likely be native inputs.
9062 @itemx source-file-name
9063 Probe @code{home-page} and @code{source} URLs and report those that are
9064 invalid. Suggest a @code{mirror://} URL when applicable. If the
9065 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9066 URL. Check that the source file name is meaningful, e.g.@: is not just a
9067 version number or ``git-checkout'', without a declared @code{file-name}
9068 (@pxref{origin Reference}).
9070 @item source-unstable-tarball
9071 Parse the @code{source} URL to determine if a tarball from GitHub is
9072 autogenerated or if it is a release tarball. Unfortunately GitHub's
9073 autogenerated tarballs are sometimes regenerated.
9076 @cindex security vulnerabilities
9077 @cindex CVE, Common Vulnerabilities and Exposures
9078 Report known vulnerabilities found in the Common Vulnerabilities and
9079 Exposures (CVE) databases of the current and past year
9080 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
9083 To view information about a particular vulnerability, visit pages such as:
9087 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9089 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9093 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9094 @code{CVE-2015-7554}.
9096 Package developers can specify in package recipes the
9097 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
9098 name and version of the package when they differ from the name or version
9099 that Guix uses, as in this example:
9105 ;; CPE calls this package "grub2".
9106 (properties '((cpe-name . "grub2")
9107 (cpe-version . "2.3")))
9110 @c See <http://www.openwall.com/lists/oss-security/2017/03/15/3>.
9111 Some entries in the CVE database do not specify which version of a
9112 package they apply to, and would thus ``stick around'' forever. Package
9113 developers who found CVE alerts and verified they can be ignored can
9114 declare them as in this example:
9120 ;; These CVEs no longer apply and can be safely ignored.
9121 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9124 "CVE-2011-5244")))))
9128 Warn about obvious source code formatting issues: trailing white space,
9129 use of tabulations, etc.
9132 The general syntax is:
9135 guix lint @var{options} @var{package}@dots{}
9138 If no package is given on the command line, then all packages are checked.
9139 The @var{options} may be zero or more of the following:
9142 @item --list-checkers
9144 List and describe all the available checkers that will be run on packages
9149 Only enable the checkers specified in a comma-separated list using the
9150 names returned by @code{--list-checkers}.
9154 @node Invoking guix size
9155 @section Invoking @command{guix size}
9158 @cindex package size
9160 @cindex @command{guix size}
9161 The @command{guix size} command helps package developers profile the
9162 disk usage of packages. It is easy to overlook the impact of an
9163 additional dependency added to a package, or the impact of using a
9164 single output for a package that could easily be split (@pxref{Packages
9165 with Multiple Outputs}). Such are the typical issues that
9166 @command{guix size} can highlight.
9168 The command can be passed one or more package specifications
9169 such as @code{gcc@@4.8}
9170 or @code{guile:debug}, or a file name in the store. Consider this
9174 $ guix size coreutils
9175 store item total self
9176 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9177 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9178 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9179 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9180 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9181 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9182 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9183 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9188 The store items listed here constitute the @dfn{transitive closure} of
9189 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9190 would be returned by:
9193 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9196 Here the output shows three columns next to store items. The first column,
9197 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9198 the store item---that is, its own size plus the size of all its
9199 dependencies. The next column, labeled ``self'', shows the size of the
9200 item itself. The last column shows the ratio of the size of the item
9201 itself to the space occupied by all the items listed here.
9203 In this example, we see that the closure of Coreutils weighs in at
9204 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9205 libraries. (That libc and GCC's libraries represent a large fraction of
9206 the closure is not a problem @i{per se} because they are always available
9207 on the system anyway.)
9209 When the package(s) passed to @command{guix size} are available in the
9210 store@footnote{More precisely, @command{guix size} looks for the
9211 @emph{ungrafted} variant of the given package(s), as returned by
9212 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9213 for information on grafts.}, @command{guix size} queries the daemon to determine its
9214 dependencies, and measures its size in the store, similar to @command{du
9215 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9218 When the given packages are @emph{not} in the store, @command{guix size}
9219 reports information based on the available substitutes
9220 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9221 store items that are not even on disk, only available remotely.
9223 You can also specify several package names:
9226 $ guix size coreutils grep sed bash
9227 store item total self
9228 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9229 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9230 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9231 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
9237 In this example we see that the combination of the four packages takes
9238 102.3@tie{}MiB in total, which is much less than the sum of each closure
9239 since they have a lot of dependencies in common.
9241 The available options are:
9245 @item --substitute-urls=@var{urls}
9246 Use substitute information from @var{urls}.
9247 @xref{client-substitute-urls, the same option for @code{guix build}}.
9249 @item --sort=@var{key}
9250 Sort lines according to @var{key}, one of the following options:
9254 the size of each item (the default);
9256 the total size of the item's closure.
9259 @item --map-file=@var{file}
9260 Write a graphical map of disk usage in PNG format to @var{file}.
9262 For the example above, the map looks like this:
9264 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
9265 produced by @command{guix size}}
9267 This option requires that
9268 @uref{http://wingolog.org/software/guile-charting/, Guile-Charting} be
9269 installed and visible in Guile's module search path. When that is not
9270 the case, @command{guix size} fails as it tries to load it.
9272 @item --system=@var{system}
9273 @itemx -s @var{system}
9274 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
9278 @node Invoking guix graph
9279 @section Invoking @command{guix graph}
9282 @cindex @command{guix graph}
9283 @cindex package dependencies
9284 Packages and their dependencies form a @dfn{graph}, specifically a
9285 directed acyclic graph (DAG). It can quickly become difficult to have a
9286 mental model of the package DAG, so the @command{guix graph} command
9287 provides a visual representation of the DAG. By default,
9288 @command{guix graph} emits a DAG representation in the input format of
9289 @uref{http://www.graphviz.org/, Graphviz}, so its output can be passed
9290 directly to the @command{dot} command of Graphviz. It can also emit an
9291 HTML page with embedded JavaScript code to display a ``chord diagram''
9292 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
9293 emit Cypher queries to construct a graph in a graph database supporting
9294 the @uref{http://www.opencypher.org/, openCypher} query language.
9295 The general syntax is:
9298 guix graph @var{options} @var{package}@dots{}
9301 For example, the following command generates a PDF file representing the
9302 package DAG for the GNU@tie{}Core Utilities, showing its build-time
9306 guix graph coreutils | dot -Tpdf > dag.pdf
9309 The output looks like this:
9311 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
9313 Nice little graph, no?
9315 But there is more than one graph! The one above is concise: it is the
9316 graph of package objects, omitting implicit inputs such as GCC, libc,
9317 grep, etc. It is often useful to have such a concise graph, but
9318 sometimes one may want to see more details. @command{guix graph} supports
9319 several types of graphs, allowing you to choose the level of detail:
9323 This is the default type used in the example above. It shows the DAG of
9324 package objects, excluding implicit dependencies. It is concise, but
9325 filters out many details.
9327 @item reverse-package
9328 This shows the @emph{reverse} DAG of packages. For example:
9331 guix graph --type=reverse-package ocaml
9334 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
9335 you are also interested in cases where OCaml is an implicit dependency, see
9336 @code{reverse-bag} below.)
9338 Note that for core packages this can yield huge graphs. If all you want
9339 is to know the number of packages that depend on a given package, use
9340 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
9341 @option{--list-dependent}}).
9344 This is the package DAG, @emph{including} implicit inputs.
9346 For instance, the following command:
9349 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
9352 ...@: yields this bigger graph:
9354 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
9356 At the bottom of the graph, we see all the implicit inputs of
9357 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
9359 Now, note that the dependencies of these implicit inputs---that is, the
9360 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
9361 here, for conciseness.
9364 Similar to @code{bag-emerged}, but this time including all the bootstrap
9367 @item bag-with-origins
9368 Similar to @code{bag}, but also showing origins and their dependencies.
9371 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
9372 it also takes implicit dependencies into account. For example:
9375 guix graph -t reverse-bag dune
9379 ...@: yields the graph of all packages that depend on Dune, directly or
9380 indirectly. Since Dune is an @emph{implicit} dependency of many packages
9381 @i{via} @code{dune-build-system}, this shows a large number of packages,
9382 whereas @code{reverse-package} would show very few if any.
9385 This is the most detailed representation: It shows the DAG of
9386 derivations (@pxref{Derivations}) and plain store items. Compared to
9387 the above representation, many additional nodes are visible, including
9388 build scripts, patches, Guile modules, etc.
9390 For this type of graph, it is also possible to pass a @file{.drv} file
9391 name instead of a package name, as in:
9394 guix graph -t derivation `guix system build -d my-config.scm`
9398 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
9399 For example, the following command shows the graph for the package
9400 module that defines the @code{guile} package:
9403 guix graph -t module guile | dot -Tpdf > module-graph.pdf
9407 All the types above correspond to @emph{build-time dependencies}. The
9408 following graph type represents the @emph{run-time dependencies}:
9412 This is the graph of @dfn{references} of a package output, as returned
9413 by @command{guix gc --references} (@pxref{Invoking guix gc}).
9415 If the given package output is not available in the store, @command{guix
9416 graph} attempts to obtain dependency information from substitutes.
9418 Here you can also pass a store file name instead of a package name. For
9419 example, the command below produces the reference graph of your profile
9420 (which can be big!):
9423 guix graph -t references `readlink -f ~/.guix-profile`
9427 This is the graph of the @dfn{referrers} of a store item, as returned by
9428 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
9430 This relies exclusively on local information from your store. For
9431 instance, let us suppose that the current Inkscape is available in 10
9432 profiles on your machine; @command{guix graph -t referrers inkscape}
9433 will show a graph rooted at Inkscape and with those 10 profiles linked
9436 It can help determine what is preventing a store item from being garbage
9441 The available options are the following:
9444 @item --type=@var{type}
9445 @itemx -t @var{type}
9446 Produce a graph output of @var{type}, where @var{type} must be one of
9447 the values listed above.
9450 List the supported graph types.
9452 @item --backend=@var{backend}
9453 @itemx -b @var{backend}
9454 Produce a graph using the selected @var{backend}.
9456 @item --list-backends
9457 List the supported graph backends.
9459 Currently, the available backends are Graphviz and d3.js.
9461 @item --expression=@var{expr}
9462 @itemx -e @var{expr}
9463 Consider the package @var{expr} evaluates to.
9465 This is useful to precisely refer to a package, as in this example:
9468 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
9471 @item --system=@var{system}
9472 @itemx -s @var{system}
9473 Display the graph for @var{system}---e.g., @code{i686-linux}.
9475 The package dependency graph is largely architecture-independent, but there
9476 are some architecture-dependent bits that this option allows you to visualize.
9481 @node Invoking guix publish
9482 @section Invoking @command{guix publish}
9484 @cindex @command{guix publish}
9485 The purpose of @command{guix publish} is to enable users to easily share
9486 their store with others, who can then use it as a substitute server
9487 (@pxref{Substitutes}).
9489 When @command{guix publish} runs, it spawns an HTTP server which allows
9490 anyone with network access to obtain substitutes from it. This means
9491 that any machine running Guix can also act as if it were a build farm,
9492 since the HTTP interface is compatible with Hydra, the software behind
9493 the @code{@value{SUBSTITUTE-SERVER}} build farm.
9495 For security, each substitute is signed, allowing recipients to check
9496 their authenticity and integrity (@pxref{Substitutes}). Because
9497 @command{guix publish} uses the signing key of the system, which is only
9498 readable by the system administrator, it must be started as root; the
9499 @code{--user} option makes it drop root privileges early on.
9501 The signing key pair must be generated before @command{guix publish} is
9502 launched, using @command{guix archive --generate-key} (@pxref{Invoking
9505 The general syntax is:
9508 guix publish @var{options}@dots{}
9511 Running @command{guix publish} without any additional arguments will
9512 spawn an HTTP server on port 8080:
9518 Once a publishing server has been authorized (@pxref{Invoking guix
9519 archive}), the daemon may download substitutes from it:
9522 guix-daemon --substitute-urls=http://example.org:8080
9525 By default, @command{guix publish} compresses archives on the fly as it
9526 serves them. This ``on-the-fly'' mode is convenient in that it requires
9527 no setup and is immediately available. However, when serving lots of
9528 clients, we recommend using the @option{--cache} option, which enables
9529 caching of the archives before they are sent to clients---see below for
9530 details. The @command{guix weather} command provides a handy way to
9531 check what a server provides (@pxref{Invoking guix weather}).
9533 As a bonus, @command{guix publish} also serves as a content-addressed
9534 mirror for source files referenced in @code{origin} records
9535 (@pxref{origin Reference}). For instance, assuming @command{guix
9536 publish} is running on @code{example.org}, the following URL returns the
9537 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
9538 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
9541 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
9544 Obviously, these URLs only work for files that are in the store; in
9545 other cases, they return 404 (``Not Found'').
9547 @cindex build logs, publication
9548 Build logs are available from @code{/log} URLs like:
9551 http://example.org/log/gwspk@dots{}-guile-2.2.3
9555 When @command{guix-daemon} is configured to save compressed build logs,
9556 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
9557 URLs return the compressed log as-is, with an appropriate
9558 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
9559 running @command{guix-daemon} with @code{--log-compression=gzip} since
9560 Web browsers can automatically decompress it, which is not the case with
9563 The following options are available:
9566 @item --port=@var{port}
9567 @itemx -p @var{port}
9568 Listen for HTTP requests on @var{port}.
9570 @item --listen=@var{host}
9571 Listen on the network interface for @var{host}. The default is to
9572 accept connections from any interface.
9574 @item --user=@var{user}
9575 @itemx -u @var{user}
9576 Change privileges to @var{user} as soon as possible---i.e., once the
9577 server socket is open and the signing key has been read.
9579 @item --compression[=@var{level}]
9580 @itemx -C [@var{level}]
9581 Compress data using the given @var{level}. When @var{level} is zero,
9582 disable compression. The range 1 to 9 corresponds to different gzip
9583 compression levels: 1 is the fastest, and 9 is the best (CPU-intensive).
9586 Unless @option{--cache} is used, compression occurs on the fly and
9587 the compressed streams are not
9588 cached. Thus, to reduce load on the machine that runs @command{guix
9589 publish}, it may be a good idea to choose a low compression level, to
9590 run @command{guix publish} behind a caching proxy, or to use
9591 @option{--cache}. Using @option{--cache} has the advantage that it
9592 allows @command{guix publish} to add @code{Content-Length} HTTP header
9595 @item --cache=@var{directory}
9596 @itemx -c @var{directory}
9597 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
9598 and only serve archives that are in cache.
9600 When this option is omitted, archives and meta-data are created
9601 on-the-fly. This can reduce the available bandwidth, especially when
9602 compression is enabled, since this may become CPU-bound. Another
9603 drawback of the default mode is that the length of archives is not known
9604 in advance, so @command{guix publish} does not add a
9605 @code{Content-Length} HTTP header to its responses, which in turn
9606 prevents clients from knowing the amount of data being downloaded.
9608 Conversely, when @option{--cache} is used, the first request for a store
9609 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
9610 background process to @dfn{bake} the archive---computing its
9611 @code{.narinfo} and compressing the archive, if needed. Once the
9612 archive is cached in @var{directory}, subsequent requests succeed and
9613 are served directly from the cache, which guarantees that clients get
9614 the best possible bandwidth.
9616 The ``baking'' process is performed by worker threads. By default, one
9617 thread per CPU core is created, but this can be customized. See
9618 @option{--workers} below.
9620 When @option{--ttl} is used, cached entries are automatically deleted
9621 when they have expired.
9623 @item --workers=@var{N}
9624 When @option{--cache} is used, request the allocation of @var{N} worker
9625 threads to ``bake'' archives.
9627 @item --ttl=@var{ttl}
9628 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
9629 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
9630 days, @code{1m} means 1 month, and so on.
9632 This allows the user's Guix to keep substitute information in cache for
9633 @var{ttl}. However, note that @code{guix publish} does not itself
9634 guarantee that the store items it provides will indeed remain available
9635 for as long as @var{ttl}.
9637 Additionally, when @option{--cache} is used, cached entries that have
9638 not been accessed for @var{ttl} and that no longer have a corresponding
9639 item in the store, may be deleted.
9641 @item --nar-path=@var{path}
9642 Use @var{path} as the prefix for the URLs of ``nar'' files
9643 (@pxref{Invoking guix archive, normalized archives}).
9645 By default, nars are served at a URL such as
9646 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
9647 change the @code{/nar} part to @var{path}.
9649 @item --public-key=@var{file}
9650 @itemx --private-key=@var{file}
9651 Use the specific @var{file}s as the public/private key pair used to sign
9652 the store items being published.
9654 The files must correspond to the same key pair (the private key is used
9655 for signing and the public key is merely advertised in the signature
9656 metadata). They must contain keys in the canonical s-expression format
9657 as produced by @command{guix archive --generate-key} (@pxref{Invoking
9658 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
9659 @file{/etc/guix/signing-key.sec} are used.
9661 @item --repl[=@var{port}]
9662 @itemx -r [@var{port}]
9663 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
9664 Reference Manual}) on @var{port} (37146 by default). This is used
9665 primarily for debugging a running @command{guix publish} server.
9668 Enabling @command{guix publish} on Guix System is a one-liner: just
9669 instantiate a @code{guix-publish-service-type} service in the @code{services} field
9670 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
9671 @code{guix-publish-service-type}}).
9673 If you are instead running Guix on a ``foreign distro'', follow these
9678 If your host distro uses the systemd init system:
9681 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
9682 /etc/systemd/system/
9683 # systemctl start guix-publish && systemctl enable guix-publish
9687 If your host distro uses the Upstart init system:
9690 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
9691 # start guix-publish
9695 Otherwise, proceed similarly with your distro's init system.
9698 @node Invoking guix challenge
9699 @section Invoking @command{guix challenge}
9701 @cindex reproducible builds
9702 @cindex verifiable builds
9703 @cindex @command{guix challenge}
9705 Do the binaries provided by this server really correspond to the source
9706 code it claims to build? Is a package build process deterministic?
9707 These are the questions the @command{guix challenge} command attempts to
9710 The former is obviously an important question: Before using a substitute
9711 server (@pxref{Substitutes}), one had better @emph{verify} that it
9712 provides the right binaries, and thus @emph{challenge} it. The latter
9713 is what enables the former: If package builds are deterministic, then
9714 independent builds of the package should yield the exact same result,
9715 bit for bit; if a server provides a binary different from the one
9716 obtained locally, it may be either corrupt or malicious.
9718 We know that the hash that shows up in @file{/gnu/store} file names is
9719 the hash of all the inputs of the process that built the file or
9720 directory---compilers, libraries, build scripts,
9721 etc. (@pxref{Introduction}). Assuming deterministic build processes,
9722 one store file name should map to exactly one build output.
9723 @command{guix challenge} checks whether there is, indeed, a single
9724 mapping by comparing the build outputs of several independent builds of
9725 any given store item.
9727 The command output looks like this:
9730 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
9731 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
9732 updating list of substitutes from 'https://guix.example.org'... 100.0%
9733 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
9734 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9735 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9736 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
9737 /gnu/store/@dots{}-git-2.5.0 contents differ:
9738 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
9739 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
9740 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
9741 /gnu/store/@dots{}-pius-2.1.1 contents differ:
9742 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9743 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9744 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
9748 6,406 store items were analyzed:
9749 - 4,749 (74.1%) were identical
9750 - 525 (8.2%) differed
9751 - 1,132 (17.7%) were inconclusive
9755 In this example, @command{guix challenge} first scans the store to
9756 determine the set of locally-built derivations---as opposed to store
9757 items that were downloaded from a substitute server---and then queries
9758 all the substitute servers. It then reports those store items for which
9759 the servers obtained a result different from the local build.
9761 @cindex non-determinism, in package builds
9762 As an example, @code{guix.example.org} always gets a different answer.
9763 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
9764 case of Git. This might indicate that the build process of Git is
9765 non-deterministic, meaning that its output varies as a function of
9766 various things that Guix does not fully control, in spite of building
9767 packages in isolated environments (@pxref{Features}). Most common
9768 sources of non-determinism include the addition of timestamps in build
9769 results, the inclusion of random numbers, and directory listings sorted
9770 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
9773 To find out what is wrong with this Git binary, we can do something along
9774 these lines (@pxref{Invoking guix archive}):
9777 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
9778 | guix archive -x /tmp/git
9779 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
9782 This command shows the difference between the files resulting from the
9783 local build, and the files resulting from the build on
9784 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
9785 diffutils, Comparing and Merging Files}). The @command{diff} command
9786 works great for text files. When binary files differ, a better option
9787 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
9788 visualize differences for all kinds of files.
9790 Once you have done that work, you can tell whether the differences are due
9791 to a non-deterministic build process or to a malicious server. We try
9792 hard to remove sources of non-determinism in packages to make it easier
9793 to verify substitutes, but of course, this is a process that
9794 involves not just Guix, but a large part of the free software community.
9795 In the meantime, @command{guix challenge} is one tool to help address
9798 If you are writing packages for Guix, you are encouraged to check
9799 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
9800 same build result as you did with:
9803 $ guix challenge @var{package}
9807 where @var{package} is a package specification such as
9808 @code{guile@@2.0} or @code{glibc:debug}.
9810 The general syntax is:
9813 guix challenge @var{options} [@var{packages}@dots{}]
9816 When a difference is found between the hash of a locally-built item and
9817 that of a server-provided substitute, or among substitutes provided by
9818 different servers, the command displays it as in the example above and
9819 its exit code is 2 (other non-zero exit codes denote other kinds of
9822 The one option that matters is:
9826 @item --substitute-urls=@var{urls}
9827 Consider @var{urls} the whitespace-separated list of substitute source
9832 Show details about matches (identical contents) in addition to
9833 information about mismatches.
9837 @node Invoking guix copy
9838 @section Invoking @command{guix copy}
9840 @cindex copy, of store items, over SSH
9841 @cindex SSH, copy of store items
9842 @cindex sharing store items across machines
9843 @cindex transferring store items across machines
9844 The @command{guix copy} command copies items from the store of one
9845 machine to that of another machine over a secure shell (SSH)
9846 connection@footnote{This command is available only when Guile-SSH was
9847 found. @xref{Requirements}, for details.}. For example, the following
9848 command copies the @code{coreutils} package, the user's profile, and all
9849 their dependencies over to @var{host}, logged in as @var{user}:
9852 guix copy --to=@var{user}@@@var{host} \
9853 coreutils `readlink -f ~/.guix-profile`
9856 If some of the items to be copied are already present on @var{host},
9857 they are not actually sent.
9859 The command below retrieves @code{libreoffice} and @code{gimp} from
9860 @var{host}, assuming they are available there:
9863 guix copy --from=@var{host} libreoffice gimp
9866 The SSH connection is established using the Guile-SSH client, which is
9867 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
9868 @file{~/.ssh/config}, and uses the SSH agent for authentication.
9870 The key used to sign items that are sent must be accepted by the remote
9871 machine. Likewise, the key used by the remote machine to sign items you
9872 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
9873 own daemon. @xref{Invoking guix archive}, for more information about
9874 store item authentication.
9876 The general syntax is:
9879 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
9882 You must always specify one of the following options:
9885 @item --to=@var{spec}
9886 @itemx --from=@var{spec}
9887 Specify the host to send to or receive from. @var{spec} must be an SSH
9888 spec such as @code{example.org}, @code{charlie@@example.org}, or
9889 @code{charlie@@example.org:2222}.
9892 The @var{items} can be either package names, such as @code{gimp}, or
9893 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
9895 When specifying the name of a package to send, it is first built if
9896 needed, unless @option{--dry-run} was specified. Common build options
9897 are supported (@pxref{Common Build Options}).
9900 @node Invoking guix container
9901 @section Invoking @command{guix container}
9903 @cindex @command{guix container}
9905 As of version @value{VERSION}, this tool is experimental. The interface
9906 is subject to radical change in the future.
9909 The purpose of @command{guix container} is to manipulate processes
9910 running within an isolated environment, commonly known as a
9911 ``container'', typically created by the @command{guix environment}
9912 (@pxref{Invoking guix environment}) and @command{guix system container}
9913 (@pxref{Invoking guix system}) commands.
9915 The general syntax is:
9918 guix container @var{action} @var{options}@dots{}
9921 @var{action} specifies the operation to perform with a container, and
9922 @var{options} specifies the context-specific arguments for the action.
9924 The following actions are available:
9928 Execute a command within the context of a running container.
9933 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
9936 @var{pid} specifies the process ID of the running container.
9937 @var{program} specifies an executable file name within the root file
9938 system of the container. @var{arguments} are the additional options that
9939 will be passed to @var{program}.
9941 The following command launches an interactive login shell inside a
9942 Guix system container, started by @command{guix system container}, and whose
9946 guix container exec 9001 /run/current-system/profile/bin/bash --login
9949 Note that the @var{pid} cannot be the parent process of a container. It
9950 must be PID 1 of the container or one of its child processes.
9954 @node Invoking guix weather
9955 @section Invoking @command{guix weather}
9957 Occasionally you're grumpy because substitutes are lacking and you end
9958 up building packages by yourself (@pxref{Substitutes}). The
9959 @command{guix weather} command reports on substitute availability on the
9960 specified servers so you can have an idea of whether you'll be grumpy
9961 today. It can sometimes be useful info as a user, but it is primarily
9962 useful to people running @command{guix publish} (@pxref{Invoking guix
9965 @cindex statistics, for substitutes
9966 @cindex availability of substitutes
9967 @cindex substitute availability
9968 @cindex weather, substitute availability
9969 Here's a sample run:
9972 $ guix weather --substitute-urls=https://guix.example.org
9973 computing 5,872 package derivations for x86_64-linux...
9974 looking for 6,128 store items on https://guix.example.org..
9975 updating list of substitutes from 'https://guix.example.org'... 100.0%
9976 https://guix.example.org
9977 43.4% substitutes available (2,658 out of 6,128)
9978 7,032.5 MiB of nars (compressed)
9979 19,824.2 MiB on disk (uncompressed)
9980 0.030 seconds per request (182.9 seconds in total)
9981 33.5 requests per second
9983 9.8% (342 out of 3,470) of the missing items are queued
9985 x86_64-linux: 518 (59.7%)
9986 i686-linux: 221 (25.5%)
9987 aarch64-linux: 128 (14.8%)
9988 build rate: 23.41 builds per hour
9989 x86_64-linux: 11.16 builds per hour
9990 i686-linux: 6.03 builds per hour
9991 aarch64-linux: 6.41 builds per hour
9994 @cindex continuous integration, statistics
9995 As you can see, it reports the fraction of all the packages for which
9996 substitutes are available on the server---regardless of whether
9997 substitutes are enabled, and regardless of whether this server's signing
9998 key is authorized. It also reports the size of the compressed archives
9999 (``nars'') provided by the server, the size the corresponding store
10000 items occupy in the store (assuming deduplication is turned off), and
10001 the server's throughput. The second part gives continuous integration
10002 (CI) statistics, if the server supports it. In addition, using the
10003 @option{--coverage} option, @command{guix weather} can list ``important''
10004 package substitutes missing on the server (see below).
10006 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10007 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10008 challenge}, it ignores signatures on those substitutes, which is
10009 innocuous since the command only gathers statistics and cannot install
10012 Among other things, it is possible to query specific system types and
10013 specific package sets. The available options are listed below.
10016 @item --substitute-urls=@var{urls}
10017 @var{urls} is the space-separated list of substitute server URLs to
10018 query. When this option is omitted, the default set of substitute
10019 servers is queried.
10021 @item --system=@var{system}
10022 @itemx -s @var{system}
10023 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10024 option can be repeated, in which case @command{guix weather} will query
10025 substitutes for several system types.
10027 @item --manifest=@var{file}
10028 Instead of querying substitutes for all the packages, only ask for those
10029 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10030 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10033 @item --coverage[=@var{count}]
10034 @itemx -c [@var{count}]
10035 Report on substitute coverage for packages: list packages with at least
10036 @var{count} dependents (zero by default) for which substitutes are
10037 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10038 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10039 @var{b} usually lacks substitutes as well. The result looks like this:
10042 $ guix weather --substitute-urls=https://ci.guix.info -c 10
10043 computing 8,983 package derivations for x86_64-linux...
10044 looking for 9,343 store items on https://ci.guix.info...
10045 updating substitutes from 'https://ci.guix.info'... 100.0%
10046 https://ci.guix.info
10047 64.7% substitutes available (6,047 out of 9,343)
10049 2502 packages are missing from 'https://ci.guix.info' for 'x86_64-linux', among which:
10050 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10051 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10052 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10056 What this example shows is that @code{kcoreaddons} and presumably the 58
10057 packages that depend on it have no substitutes at @code{ci.guix.info};
10058 likewise for @code{qgpgme} and the 46 packages that depend on it.
10060 If you are a Guix developer, or if you are taking care of this build farm,
10061 you'll probably want to have a closer look at these packages: they may simply
10065 @node Invoking guix processes
10066 @section Invoking @command{guix processes}
10068 The @command{guix processes} command can be useful to developers and system
10069 administrators, especially on multi-user machines and on build farms: it lists
10070 the current sessions (connections to the daemon), as well as information about
10071 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10072 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10073 listed.}. Here's an example of the information it returns:
10076 $ sudo guix processes
10079 ClientCommand: guix environment --ad-hoc python
10083 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10087 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10088 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10089 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10090 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10091 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10092 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10093 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10096 In this example we see that @command{guix-daemon} has three clients:
10097 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10098 integration tool; their process identifier (PID) is given by the
10099 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10100 @command{guix-daemon} sub-process of this particular session.
10102 The @code{LockHeld} fields show which store items are currently locked by this
10103 session, which corresponds to store items being built or substituted (the
10104 @code{LockHeld} field is not displayed when @command{guix processes} is not
10105 running as root.) Last, by looking at the @code{ChildProcess} field, we
10106 understand that these three builds are being offloaded (@pxref{Daemon Offload
10109 The output is in Recutils format so we can use the handy @command{recsel}
10110 command to select sessions of interest (@pxref{Selection Expressions,,,
10111 recutils, GNU recutils manual}). As an example, the command shows the command
10112 line and PID of the client that triggered the build of a Perl package:
10115 $ sudo guix processes | \
10116 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10118 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10122 @node System Configuration
10123 @chapter System Configuration
10125 @cindex system configuration
10126 The Guix System Distribution supports a consistent whole-system configuration
10127 mechanism. By that we mean that all aspects of the global system
10128 configuration---such as the available system services, timezone and
10129 locale settings, user accounts---are declared in a single place. Such
10130 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10132 One of the advantages of putting all the system configuration under the
10133 control of Guix is that it supports transactional system upgrades, and
10134 makes it possible to roll back to a previous system instantiation,
10135 should something go wrong with the new one (@pxref{Features}). Another
10136 advantage is that it makes it easy to replicate the exact same configuration
10137 across different machines, or at different points in time, without
10138 having to resort to additional administration tools layered on top of
10139 the own tools of the system.
10140 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
10142 This section describes this mechanism. First we focus on the system
10143 administrator's viewpoint---explaining how the system is configured and
10144 instantiated. Then we show how this mechanism can be extended, for
10145 instance to support new system services.
10148 * Using the Configuration System:: Customizing your GNU system.
10149 * operating-system Reference:: Detail of operating-system declarations.
10150 * File Systems:: Configuring file system mounts.
10151 * Mapped Devices:: Block device extra processing.
10152 * User Accounts:: Specifying user accounts.
10153 * Keyboard Layout:: How the system interprets key strokes.
10154 * Locales:: Language and cultural convention settings.
10155 * Services:: Specifying system services.
10156 * Setuid Programs:: Programs running with root privileges.
10157 * X.509 Certificates:: Authenticating HTTPS servers.
10158 * Name Service Switch:: Configuring libc's name service switch.
10159 * Initial RAM Disk:: Linux-Libre bootstrapping.
10160 * Bootloader Configuration:: Configuring the boot loader.
10161 * Invoking guix system:: Instantiating a system configuration.
10162 * Running Guix in a VM:: How to run Guix System in a virtual machine.
10163 * Defining Services:: Adding new service definitions.
10166 @node Using the Configuration System
10167 @section Using the Configuration System
10169 The operating system is configured by providing an
10170 @code{operating-system} declaration in a file that can then be passed to
10171 the @command{guix system} command (@pxref{Invoking guix system}). A
10172 simple setup, with the default system services, the default Linux-Libre
10173 kernel, initial RAM disk, and boot loader looks like this:
10175 @findex operating-system
10177 @include os-config-bare-bones.texi
10180 This example should be self-describing. Some of the fields defined
10181 above, such as @code{host-name} and @code{bootloader}, are mandatory.
10182 Others, such as @code{packages} and @code{services}, can be omitted, in
10183 which case they get a default value.
10185 Below we discuss the effect of some of the most important fields
10186 (@pxref{operating-system Reference}, for details about all the available
10187 fields), and how to @dfn{instantiate} the operating system using
10188 @command{guix system}.
10190 @unnumberedsubsec Bootloader
10192 @cindex legacy boot, on Intel machines
10193 @cindex BIOS boot, on Intel machines
10196 The @code{bootloader} field describes the method that will be used to boot
10197 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
10198 mode, as in the example above. However, more recent machines rely instead on
10199 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
10200 the @code{bootloader} field should contain something along these lines:
10203 (bootloader-configuration
10204 (bootloader grub-efi-bootloader)
10205 (target "/boot/efi"))
10208 @xref{Bootloader Configuration}, for more information on the available
10209 configuration options.
10211 @unnumberedsubsec Globally-Visible Packages
10213 @vindex %base-packages
10214 The @code{packages} field lists packages that will be globally visible
10215 on the system, for all user accounts---i.e., in every user's @code{PATH}
10216 environment variable---in addition to the per-user profiles
10217 (@pxref{Invoking guix package}). The @var{%base-packages} variable
10218 provides all the tools one would expect for basic user and administrator
10219 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
10220 the GNU Zile lightweight text editor, @command{find}, @command{grep},
10221 etc. The example above adds GNU@tie{}Screen to those,
10222 taken from the @code{(gnu packages screen)}
10223 module (@pxref{Package Modules}). The
10224 @code{(list package output)} syntax can be used to add a specific output
10228 (use-modules (gnu packages))
10229 (use-modules (gnu packages dns))
10233 (packages (cons (list bind "utils")
10237 @findex specification->package
10238 Referring to packages by variable name, like @code{bind} above, has
10239 the advantage of being unambiguous; it also allows typos and such to be
10240 diagnosed right away as ``unbound variables''. The downside is that one
10241 needs to know which module defines which package, and to augment the
10242 @code{use-package-modules} line accordingly. To avoid that, one can use
10243 the @code{specification->package} procedure of the @code{(gnu packages)}
10244 module, which returns the best package for a given name or name and
10248 (use-modules (gnu packages))
10252 (packages (append (map specification->package
10253 '("tcpdump" "htop" "gnupg@@2.0"))
10257 @unnumberedsubsec System Services
10260 @vindex %base-services
10261 The @code{services} field lists @dfn{system services} to be made
10262 available when the system starts (@pxref{Services}).
10263 The @code{operating-system} declaration above specifies that, in
10264 addition to the basic services, we want the OpenSSH secure shell
10265 daemon listening on port 2222 (@pxref{Networking Services,
10266 @code{openssh-service-type}}). Under the hood,
10267 @code{openssh-service-type} arranges so that @command{sshd} is started with the
10268 right command-line options, possibly with supporting configuration files
10269 generated as needed (@pxref{Defining Services}).
10271 @cindex customization, of services
10272 @findex modify-services
10273 Occasionally, instead of using the base services as is, you will want to
10274 customize them. To do this, use @code{modify-services} (@pxref{Service
10275 Reference, @code{modify-services}}) to modify the list.
10277 For example, suppose you want to modify @code{guix-daemon} and Mingetty
10278 (the console log-in) in the @var{%base-services} list (@pxref{Base
10279 Services, @code{%base-services}}). To do that, you can write the
10280 following in your operating system declaration:
10283 (define %my-services
10284 ;; My very own list of services.
10285 (modify-services %base-services
10286 (guix-service-type config =>
10287 (guix-configuration
10289 (use-substitutes? #f)
10290 (extra-options '("--gc-keep-derivations"))))
10291 (mingetty-service-type config =>
10292 (mingetty-configuration
10293 (inherit config)))))
10297 (services %my-services))
10300 This changes the configuration---i.e., the service parameters---of the
10301 @code{guix-service-type} instance, and that of all the
10302 @code{mingetty-service-type} instances in the @var{%base-services} list.
10303 Observe how this is accomplished: first, we arrange for the original
10304 configuration to be bound to the identifier @code{config} in the
10305 @var{body}, and then we write the @var{body} so that it evaluates to the
10306 desired configuration. In particular, notice how we use @code{inherit}
10307 to create a new configuration which has the same values as the old
10308 configuration, but with a few modifications.
10310 @cindex encrypted disk
10311 The configuration for a typical ``desktop'' usage, with an encrypted
10312 root partition, the X11 display
10313 server, GNOME and Xfce (users can choose which of these desktop
10314 environments to use at the log-in screen by pressing @kbd{F1}), network
10315 management, power management, and more, would look like this:
10318 @include os-config-desktop.texi
10321 A graphical system with a choice of lightweight window managers
10322 instead of full-blown desktop environments would look like this:
10325 @include os-config-lightweight-desktop.texi
10328 This example refers to the @file{/boot/efi} file system by its UUID,
10329 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
10330 as returned by the @command{blkid} command.
10332 @xref{Desktop Services}, for the exact list of services provided by
10333 @var{%desktop-services}. @xref{X.509 Certificates}, for background
10334 information about the @code{nss-certs} package that is used here.
10336 Again, @var{%desktop-services} is just a list of service objects. If
10337 you want to remove services from there, you can do so using the
10338 procedures for list filtering (@pxref{SRFI-1 Filtering and
10339 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
10340 following expression returns a list that contains all the services in
10341 @var{%desktop-services} minus the Avahi service:
10344 (remove (lambda (service)
10345 (eq? (service-kind service) avahi-service-type))
10349 @unnumberedsubsec Instantiating the System
10351 Assuming the @code{operating-system} declaration
10352 is stored in the @file{my-system-config.scm}
10353 file, the @command{guix system reconfigure my-system-config.scm} command
10354 instantiates that configuration, and makes it the default GRUB boot
10355 entry (@pxref{Invoking guix system}).
10357 The normal way to change the system configuration is by updating this
10358 file and re-running @command{guix system reconfigure}. One should never
10359 have to touch files in @file{/etc} or to run commands that modify the
10360 system state such as @command{useradd} or @command{grub-install}. In
10361 fact, you must avoid that since that would not only void your warranty
10362 but also prevent you from rolling back to previous versions of your
10363 system, should you ever need to.
10365 @cindex roll-back, of the operating system
10366 Speaking of roll-back, each time you run @command{guix system
10367 reconfigure}, a new @dfn{generation} of the system is created---without
10368 modifying or deleting previous generations. Old system generations get
10369 an entry in the bootloader boot menu, allowing you to boot them in case
10370 something went wrong with the latest generation. Reassuring, no? The
10371 @command{guix system list-generations} command lists the system
10372 generations available on disk. It is also possible to roll back the
10373 system via the commands @command{guix system roll-back} and
10374 @command{guix system switch-generation}.
10376 Although the @command{guix system reconfigure} command will not modify
10377 previous generations, you must take care when the current generation is not
10378 the latest (e.g., after invoking @command{guix system roll-back}), since
10379 the operation might overwrite a later generation (@pxref{Invoking guix
10382 @unnumberedsubsec The Programming Interface
10384 At the Scheme level, the bulk of an @code{operating-system} declaration
10385 is instantiated with the following monadic procedure (@pxref{The Store
10388 @deffn {Monadic Procedure} operating-system-derivation os
10389 Return a derivation that builds @var{os}, an @code{operating-system}
10390 object (@pxref{Derivations}).
10392 The output of the derivation is a single directory that refers to all
10393 the packages, configuration files, and other supporting files needed to
10394 instantiate @var{os}.
10397 This procedure is provided by the @code{(gnu system)} module. Along
10398 with @code{(gnu services)} (@pxref{Services}), this module contains the
10399 guts of Guix System. Make sure to visit it!
10402 @node operating-system Reference
10403 @section @code{operating-system} Reference
10405 This section summarizes all the options available in
10406 @code{operating-system} declarations (@pxref{Using the Configuration
10409 @deftp {Data Type} operating-system
10410 This is the data type representing an operating system configuration.
10411 By that, we mean all the global system configuration, not per-user
10412 configuration (@pxref{Using the Configuration System}).
10415 @item @code{kernel} (default: @var{linux-libre})
10416 The package object of the operating system kernel to use@footnote{Currently
10417 only the Linux-libre kernel is supported. In the future, it will be
10418 possible to use the GNU@tie{}Hurd.}.
10420 @item @code{kernel-arguments} (default: @code{'()})
10421 List of strings or gexps representing additional arguments to pass on
10422 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
10424 @item @code{bootloader}
10425 The system bootloader configuration object. @xref{Bootloader Configuration}.
10427 @item @code{keyboard-layout} (default: @code{#f})
10428 This field specifies the keyboard layout to use in the console. It can be
10429 either @code{#f}, in which case the default keyboard layout is used (usually
10430 US English), or a @code{<keyboard-layout>} record.
10432 This keyboard layout is in effect as soon as the kernel has booted. For
10433 instance, it is the keyboard layout in effect when you type a passphrase if
10434 your root file system is on a @code{luks-device-mapping} mapped device
10435 (@pxref{Mapped Devices}).
10438 This does @emph{not} specify the keyboard layout used by the bootloader, nor
10439 that used by the graphical display server. @xref{Bootloader Configuration},
10440 for information on how to specify the bootloader's keyboard layout. @xref{X
10441 Window}, for information on how to specify the keyboard layout used by the X
10445 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
10447 @cindex initial RAM disk
10448 The list of Linux kernel modules that need to be available in the
10449 initial RAM disk. @xref{Initial RAM Disk}.
10451 @item @code{initrd} (default: @code{base-initrd})
10452 A procedure that returns an initial RAM disk for the Linux
10453 kernel. This field is provided to support low-level customization and
10454 should rarely be needed for casual use. @xref{Initial RAM Disk}.
10456 @item @code{firmware} (default: @var{%base-firmware})
10458 List of firmware packages loadable by the operating system kernel.
10460 The default includes firmware needed for Atheros- and Broadcom-based
10461 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
10462 respectively). @xref{Hardware Considerations}, for more info on
10463 supported hardware.
10465 @item @code{host-name}
10468 @item @code{hosts-file}
10470 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
10471 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
10472 Reference Manual}). The default is a file with entries for
10473 @code{localhost} and @var{host-name}.
10475 @item @code{mapped-devices} (default: @code{'()})
10476 A list of mapped devices. @xref{Mapped Devices}.
10478 @item @code{file-systems}
10479 A list of file systems. @xref{File Systems}.
10481 @item @code{swap-devices} (default: @code{'()})
10482 @cindex swap devices
10483 A list of strings identifying devices or files to be used for ``swap
10484 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
10485 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
10486 It is possible to specify a swap file in a file system on a mapped
10487 device, provided that the necessary device mapping and file system are
10488 also specified. @xref{Mapped Devices} and @ref{File Systems}.
10490 @item @code{users} (default: @code{%base-user-accounts})
10491 @itemx @code{groups} (default: @var{%base-groups})
10492 List of user accounts and groups. @xref{User Accounts}.
10494 If the @code{users} list lacks a user account with UID@tie{}0, a
10495 ``root'' account with UID@tie{}0 is automatically added.
10497 @item @code{skeletons} (default: @code{(default-skeletons)})
10498 A list target file name/file-like object tuples (@pxref{G-Expressions,
10499 file-like objects}). These are the skeleton files that will be added to
10500 the home directory of newly-created user accounts.
10502 For instance, a valid value may look like this:
10505 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
10506 (".guile" ,(plain-file "guile"
10507 "(use-modules (ice-9 readline))
10508 (activate-readline)")))
10511 @item @code{issue} (default: @var{%default-issue})
10512 A string denoting the contents of the @file{/etc/issue} file, which is
10513 displayed when users log in on a text console.
10515 @item @code{packages} (default: @var{%base-packages})
10516 The set of packages installed in the global profile, which is accessible
10517 at @file{/run/current-system/profile}.
10519 The default set includes core utilities and it is good practice to
10520 install non-core utilities in user profiles (@pxref{Invoking guix
10523 @item @code{timezone}
10524 A timezone identifying string---e.g., @code{"Europe/Paris"}.
10526 You can run the @command{tzselect} command to find out which timezone
10527 string corresponds to your region. Choosing an invalid timezone name
10528 causes @command{guix system} to fail.
10530 @item @code{locale} (default: @code{"en_US.utf8"})
10531 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
10532 Library Reference Manual}). @xref{Locales}, for more information.
10534 @item @code{locale-definitions} (default: @var{%default-locale-definitions})
10535 The list of locale definitions to be compiled and that may be used at
10536 run time. @xref{Locales}.
10538 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
10539 The list of GNU@tie{}libc packages whose locale data and tools are used
10540 to build the locale definitions. @xref{Locales}, for compatibility
10541 considerations that justify this option.
10543 @item @code{name-service-switch} (default: @var{%default-nss})
10544 Configuration of the libc name service switch (NSS)---a
10545 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
10548 @item @code{services} (default: @var{%base-services})
10549 A list of service objects denoting system services. @xref{Services}.
10551 @cindex essential services
10552 @item @code{essential-services} (default: ...)
10553 The list of ``essential services''---i.e., things like instances of
10554 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
10555 Reference}), which are derived from the operating system definition itself.
10556 As a user you should @emph{never} need to touch this field.
10558 @item @code{pam-services} (default: @code{(base-pam-services)})
10560 @cindex pluggable authentication modules
10561 Linux @dfn{pluggable authentication module} (PAM) services.
10562 @c FIXME: Add xref to PAM services section.
10564 @item @code{setuid-programs} (default: @var{%setuid-programs})
10565 List of string-valued G-expressions denoting setuid programs.
10566 @xref{Setuid Programs}.
10568 @item @code{sudoers-file} (default: @var{%sudoers-specification})
10569 @cindex sudoers file
10570 The contents of the @file{/etc/sudoers} file as a file-like object
10571 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
10573 This file specifies which users can use the @command{sudo} command, what
10574 they are allowed to do, and what privileges they may gain. The default
10575 is that only @code{root} and members of the @code{wheel} group may use
10582 @section File Systems
10584 The list of file systems to be mounted is specified in the
10585 @code{file-systems} field of the operating system declaration
10586 (@pxref{Using the Configuration System}). Each file system is declared
10587 using the @code{file-system} form, like this:
10591 (mount-point "/home")
10592 (device "/dev/sda3")
10596 As usual, some of the fields are mandatory---those shown in the example
10597 above---while others can be omitted. These are described below.
10599 @deftp {Data Type} file-system
10600 Objects of this type represent file systems to be mounted. They
10601 contain the following members:
10605 This is a string specifying the type of the file system---e.g.,
10608 @item @code{mount-point}
10609 This designates the place where the file system is to be mounted.
10611 @item @code{device}
10612 This names the ``source'' of the file system. It can be one of three
10613 things: a file system label, a file system UUID, or the name of a
10614 @file{/dev} node. Labels and UUIDs offer a way to refer to file
10615 systems without having to hard-code their actual device
10616 name@footnote{Note that, while it is tempting to use
10617 @file{/dev/disk/by-uuid} and similar device names to achieve the same
10618 result, this is not recommended: These special device nodes are created
10619 by the udev daemon and may be unavailable at the time the device is
10622 @findex file-system-label
10623 File system labels are created using the @code{file-system-label}
10624 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
10625 plain strings. Here's an example of a file system referred to by its
10626 label, as shown by the @command{e2label} command:
10630 (mount-point "/home")
10632 (device (file-system-label "my-home")))
10636 UUIDs are converted from their string representation (as shown by the
10637 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
10638 @code{uuid} form expects 16-byte UUIDs as defined in
10639 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
10640 form of UUID used by the ext2 family of file systems and others, but it
10641 is different from ``UUIDs'' found in FAT file systems, for instance.},
10646 (mount-point "/home")
10648 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
10651 When the source of a file system is a mapped device (@pxref{Mapped
10652 Devices}), its @code{device} field @emph{must} refer to the mapped
10653 device name---e.g., @file{"/dev/mapper/root-partition"}.
10654 This is required so that
10655 the system knows that mounting the file system depends on having the
10656 corresponding device mapping established.
10658 @item @code{flags} (default: @code{'()})
10659 This is a list of symbols denoting mount flags. Recognized flags
10660 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
10661 access to special files), @code{no-suid} (ignore setuid and setgid
10662 bits), and @code{no-exec} (disallow program execution.)
10664 @item @code{options} (default: @code{#f})
10665 This is either @code{#f}, or a string denoting mount options.
10667 @item @code{mount?} (default: @code{#t})
10668 This value indicates whether to automatically mount the file system when
10669 the system is brought up. When set to @code{#f}, the file system gets
10670 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
10671 is not automatically mounted.
10673 @item @code{needed-for-boot?} (default: @code{#f})
10674 This Boolean value indicates whether the file system is needed when
10675 booting. If that is true, then the file system is mounted when the
10676 initial RAM disk (initrd) is loaded. This is always the case, for
10677 instance, for the root file system.
10679 @item @code{check?} (default: @code{#t})
10680 This Boolean indicates whether the file system needs to be checked for
10681 errors before being mounted.
10683 @item @code{create-mount-point?} (default: @code{#f})
10684 When true, the mount point is created if it does not exist yet.
10686 @item @code{dependencies} (default: @code{'()})
10687 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
10688 representing file systems that must be mounted or mapped devices that
10689 must be opened before (and unmounted or closed after) this one.
10691 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
10692 a dependency of @file{/sys/fs/cgroup/cpu} and
10693 @file{/sys/fs/cgroup/memory}.
10695 Another example is a file system that depends on a mapped device, for
10696 example for an encrypted partition (@pxref{Mapped Devices}).
10700 The @code{(gnu system file-systems)} exports the following useful
10703 @defvr {Scheme Variable} %base-file-systems
10704 These are essential file systems that are required on normal systems,
10705 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
10706 below.) Operating system declarations should always contain at least
10710 @defvr {Scheme Variable} %pseudo-terminal-file-system
10711 This is the file system to be mounted as @file{/dev/pts}. It supports
10712 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
10713 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
10714 Manual}). Pseudo-terminals are used by terminal emulators such as
10718 @defvr {Scheme Variable} %shared-memory-file-system
10719 This file system is mounted as @file{/dev/shm} and is used to support
10720 memory sharing across processes (@pxref{Memory-mapped I/O,
10721 @code{shm_open},, libc, The GNU C Library Reference Manual}).
10724 @defvr {Scheme Variable} %immutable-store
10725 This file system performs a read-only ``bind mount'' of
10726 @file{/gnu/store}, making it read-only for all the users including
10727 @code{root}. This prevents against accidental modification by software
10728 running as @code{root} or by system administrators.
10730 The daemon itself is still able to write to the store: it remounts it
10731 read-write in its own ``name space.''
10734 @defvr {Scheme Variable} %binary-format-file-system
10735 The @code{binfmt_misc} file system, which allows handling of arbitrary
10736 executable file types to be delegated to user space. This requires the
10737 @code{binfmt.ko} kernel module to be loaded.
10740 @defvr {Scheme Variable} %fuse-control-file-system
10741 The @code{fusectl} file system, which allows unprivileged users to mount
10742 and unmount user-space FUSE file systems. This requires the
10743 @code{fuse.ko} kernel module to be loaded.
10746 @node Mapped Devices
10747 @section Mapped Devices
10749 @cindex device mapping
10750 @cindex mapped devices
10751 The Linux kernel has a notion of @dfn{device mapping}: a block device,
10752 such as a hard disk partition, can be @dfn{mapped} into another device,
10753 usually in @code{/dev/mapper/},
10754 with additional processing over the data that flows through
10755 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
10756 concept of a ``mapped device'' and that of a file system: both boil down
10757 to @emph{translating} input/output operations made on a file to
10758 operations on its backing store. Thus, the Hurd implements mapped
10759 devices, like file systems, using the generic @dfn{translator} mechanism
10760 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
10761 typical example is encryption device mapping: all writes to the mapped
10762 device are encrypted, and all reads are deciphered, transparently.
10763 Guix extends this notion by considering any device or set of devices that
10764 are @dfn{transformed} in some way to create a new device; for instance,
10765 RAID devices are obtained by @dfn{assembling} several other devices, such
10766 as hard disks or partitions, into a new one that behaves as one partition.
10767 Other examples, not yet implemented, are LVM logical volumes.
10769 Mapped devices are declared using the @code{mapped-device} form,
10770 defined as follows; for examples, see below.
10772 @deftp {Data Type} mapped-device
10773 Objects of this type represent device mappings that will be made when
10774 the system boots up.
10778 This is either a string specifying the name of the block device to be mapped,
10779 such as @code{"/dev/sda3"}, or a list of such strings when several devices
10780 need to be assembled for creating a new one.
10783 This string specifies the name of the resulting mapped device. For
10784 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
10785 specifying @code{"my-partition"} leads to the creation of
10786 the @code{"/dev/mapper/my-partition"} device.
10787 For RAID devices of type @code{raid-device-mapping}, the full device name
10788 such as @code{"/dev/md0"} needs to be given.
10791 This must be a @code{mapped-device-kind} object, which specifies how
10792 @var{source} is mapped to @var{target}.
10796 @defvr {Scheme Variable} luks-device-mapping
10797 This defines LUKS block device encryption using the @command{cryptsetup}
10798 command from the package with the same name. It relies on the
10799 @code{dm-crypt} Linux kernel module.
10802 @defvr {Scheme Variable} raid-device-mapping
10803 This defines a RAID device, which is assembled using the @code{mdadm}
10804 command from the package with the same name. It requires a Linux kernel
10805 module for the appropriate RAID level to be loaded, such as @code{raid456}
10806 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
10809 @cindex disk encryption
10811 The following example specifies a mapping from @file{/dev/sda3} to
10812 @file{/dev/mapper/home} using LUKS---the
10813 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
10814 standard mechanism for disk encryption.
10815 The @file{/dev/mapper/home}
10816 device can then be used as the @code{device} of a @code{file-system}
10817 declaration (@pxref{File Systems}).
10821 (source "/dev/sda3")
10823 (type luks-device-mapping))
10826 Alternatively, to become independent of device numbering, one may obtain
10827 the LUKS UUID (@dfn{unique identifier}) of the source device by a
10831 cryptsetup luksUUID /dev/sda3
10834 and use it as follows:
10838 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
10840 (type luks-device-mapping))
10843 @cindex swap encryption
10844 It is also desirable to encrypt swap space, since swap space may contain
10845 sensitive data. One way to accomplish that is to use a swap file in a
10846 file system on a device mapped via LUKS encryption. In this way, the
10847 swap file is encrypted because the entire device is encrypted.
10848 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
10850 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
10851 may be declared as follows:
10855 (source (list "/dev/sda1" "/dev/sdb1"))
10856 (target "/dev/md0")
10857 (type raid-device-mapping))
10860 The @file{/dev/md0} device can then be used as the @code{device} of a
10861 @code{file-system} declaration (@pxref{File Systems}).
10862 Note that the RAID level need not be given; it is chosen during the
10863 initial creation and formatting of the RAID device and is determined
10864 automatically later.
10867 @node User Accounts
10868 @section User Accounts
10872 @cindex user accounts
10873 User accounts and groups are entirely managed through the
10874 @code{operating-system} declaration. They are specified with the
10875 @code{user-account} and @code{user-group} forms:
10881 (supplementary-groups '("wheel" ;allow use of sudo, etc.
10882 "audio" ;sound card
10883 "video" ;video devices such as webcams
10884 "cdrom")) ;the good ol' CD-ROM
10885 (comment "Bob's sister")
10886 (home-directory "/home/alice"))
10889 When booting or upon completion of @command{guix system reconfigure},
10890 the system ensures that only the user accounts and groups specified in
10891 the @code{operating-system} declaration exist, and with the specified
10892 properties. Thus, account or group creations or modifications made by
10893 directly invoking commands such as @command{useradd} are lost upon
10894 reconfiguration or reboot. This ensures that the system remains exactly
10897 @deftp {Data Type} user-account
10898 Objects of this type represent user accounts. The following members may
10903 The name of the user account.
10907 This is the name (a string) or identifier (a number) of the user group
10908 this account belongs to.
10910 @item @code{supplementary-groups} (default: @code{'()})
10911 Optionally, this can be defined as a list of group names that this
10912 account belongs to.
10914 @item @code{uid} (default: @code{#f})
10915 This is the user ID for this account (a number), or @code{#f}. In the
10916 latter case, a number is automatically chosen by the system when the
10917 account is created.
10919 @item @code{comment} (default: @code{""})
10920 A comment about the account, such as the account owner's full name.
10922 @item @code{home-directory}
10923 This is the name of the home directory for the account.
10925 @item @code{create-home-directory?} (default: @code{#t})
10926 Indicates whether the home directory of this account should be created
10927 if it does not exist yet.
10929 @item @code{shell} (default: Bash)
10930 This is a G-expression denoting the file name of a program to be used as
10931 the shell (@pxref{G-Expressions}).
10933 @item @code{system?} (default: @code{#f})
10934 This Boolean value indicates whether the account is a ``system''
10935 account. System accounts are sometimes treated specially; for instance,
10936 graphical login managers do not list them.
10938 @anchor{user-account-password}
10939 @cindex password, for user accounts
10940 @item @code{password} (default: @code{#f})
10941 You would normally leave this field to @code{#f}, initialize user
10942 passwords as @code{root} with the @command{passwd} command, and then let
10943 users change it with @command{passwd}. Passwords set with
10944 @command{passwd} are of course preserved across reboot and
10947 If you @emph{do} want to set an initial password for an account, then
10948 this field must contain the encrypted password, as a string. You can use the
10949 @code{crypt} procedure for this purpose:
10956 ;; Specify a SHA-512-hashed initial password.
10957 (password (crypt "InitialPassword!" "$6$abc")))
10961 The hash of this initial password will be available in a file in
10962 @file{/gnu/store}, readable by all the users, so this method must be used with
10966 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
10967 more information on password encryption, and @ref{Encryption,,, guile, GNU
10968 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
10974 User group declarations are even simpler:
10977 (user-group (name "students"))
10980 @deftp {Data Type} user-group
10981 This type is for, well, user groups. There are just a few fields:
10985 The name of the group.
10987 @item @code{id} (default: @code{#f})
10988 The group identifier (a number). If @code{#f}, a new number is
10989 automatically allocated when the group is created.
10991 @item @code{system?} (default: @code{#f})
10992 This Boolean value indicates whether the group is a ``system'' group.
10993 System groups have low numerical IDs.
10995 @item @code{password} (default: @code{#f})
10996 What, user groups can have a password? Well, apparently yes. Unless
10997 @code{#f}, this field specifies the password of the group.
11002 For convenience, a variable lists all the basic user groups one may
11005 @defvr {Scheme Variable} %base-groups
11006 This is the list of basic user groups that users and/or packages expect
11007 to be present on the system. This includes groups such as ``root'',
11008 ``wheel'', and ``users'', as well as groups used to control access to
11009 specific devices such as ``audio'', ``disk'', and ``cdrom''.
11012 @defvr {Scheme Variable} %base-user-accounts
11013 This is the list of basic system accounts that programs may expect to
11014 find on a GNU/Linux system, such as the ``nobody'' account.
11016 Note that the ``root'' account is not included here. It is a
11017 special-case and is automatically added whether or not it is specified.
11020 @node Keyboard Layout
11021 @section Keyboard Layout
11023 @cindex keyboard layout
11025 To specify what each key of your keyboard does, you need to tell the operating
11026 system what @dfn{keyboard layout} you want to use. The default, when nothing
11027 is specified, is the US English QWERTY layout for 105-key PC keyboards.
11028 However, German speakers will usually prefer the German QWERTZ layout, French
11029 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
11030 or bépo, and they might even want to further customize the effect of some of
11031 the keys. This section explains how to get that done.
11033 @cindex keyboard layout, definition
11034 There are three components that will want to know about your keyboard layout:
11038 The @emph{bootloader} may want to know what keyboard layout you want to use
11039 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
11040 you want, for instance, to make sure that you can type the passphrase of your
11041 encrypted root partition using the right layout.
11044 The @emph{operating system kernel}, Linux, will need that so that the console
11045 is properly configured (@pxref{operating-system Reference,
11046 @code{keyboard-layout}}).
11049 The @emph{graphical display server}, usually Xorg, also has its own idea of
11050 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
11053 Guix allows you to configure all three separately but, fortunately, it allows
11054 you to share the same keyboard layout for all three components.
11056 @cindex XKB, keyboard layouts
11057 Keyboard layouts are represented by records created by the
11058 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
11059 the X Keyboard extension (XKB), each layout has four attributes: a name (often
11060 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
11061 optional variant name, an optional keyboard model name, and a possibly empty
11062 list of additional options. In most cases the layout name is all you care
11063 about. Here are a few example:
11066 ;; The German QWERTZ layout. Here we assume a standard
11067 ;; "pc105" keyboard model.
11068 (keyboard-layout "de")
11070 ;; The bépo variant of the French layout.
11071 (keyboard-layout "fr" "bepo")
11073 ;; The Catalan layout.
11074 (keyboard-layout "es" "cat")
11076 ;; The Latin American Spanish layout. In addition, the
11077 ;; "Caps Lock" key is used as an additional "Ctrl" key,
11078 ;; and the "Menu" key is used as a "Compose" key to enter
11079 ;; accented letters.
11080 (keyboard-layout "latam"
11081 #:options '("ctrl:nocaps" "compose:menu"))
11083 ;; The Russian layout for a ThinkPad keyboard.
11084 (keyboard-layout "ru" #:model "thinkpad")
11086 ;; The "US international" layout, which is the US layout plus
11087 ;; dead keys to enter accented characters. This is for an
11088 ;; Apple MacBook keyboard.
11089 (keyboard-layout "us" "intl" #:model "macbook78")
11092 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
11093 for a complete list of supported layouts, variants, and models.
11095 @cindex keyboard layout, configuration
11096 Let's say you want your system to use the Turkish keyboard layout throughout
11097 your system---bootloader, console, and Xorg. Here's what your system
11098 configuration would look like:
11100 @findex set-xorg-configuration
11102 ;; Using the Turkish layout for the bootloader, the console,
11107 (keyboard-layout (keyboard-layout "tr")) ;for the console
11108 (bootloader (bootloader-configuration
11109 (bootloader grub-efi-bootloader)
11110 (target "/boot/efi")
11111 (keyboard-layout keyboard-layout))) ;for GRUB
11112 (services (cons (set-xorg-configuration
11113 (xorg-configuration ;for Xorg
11114 (keyboard-layout keyboard-layout)))
11115 %desktop-services)))
11118 In the example above, for GRUB and for Xorg, we just refer to the
11119 @code{keyboard-layout} field defined above, but we could just as well refer to
11120 a different layout. The @code{set-xorg-configuration} procedure communicates
11121 the desired Xorg configuration to the graphical log-in manager, by default
11124 We've discussed how to specify the @emph{default} keyboard layout of your
11125 system when it starts, but you can also adjust it at run time:
11129 If you're using GNOME, its settings panel has a ``Region & Language'' entry
11130 where you can select one or more keyboard layouts.
11133 Under Xorg, the @command{setxkbmap} command (from the same-named package)
11134 allows you to change the current layout. For example, this is how you would
11135 change the layout to US Dvorak:
11138 setxkbmap us dvorak
11142 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
11143 console. However, note that @code{loadkeys} does @emph{not} use the XKB
11144 keyboard layout categorization described above. The command below loads the
11145 French bépo layout:
11156 A @dfn{locale} defines cultural conventions for a particular language
11157 and region of the world (@pxref{Locales,,, libc, The GNU C Library
11158 Reference Manual}). Each locale has a name that typically has the form
11159 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
11160 @code{fr_LU.utf8} designates the locale for the French language, with
11161 cultural conventions from Luxembourg, and using the UTF-8 encoding.
11163 @cindex locale definition
11164 Usually, you will want to specify the default locale for the machine
11165 using the @code{locale} field of the @code{operating-system} declaration
11166 (@pxref{operating-system Reference, @code{locale}}).
11168 The selected locale is automatically added to the @dfn{locale
11169 definitions} known to the system if needed, with its codeset inferred
11170 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
11171 @code{UTF-8} codeset. Additional locale definitions can be specified in
11172 the @code{locale-definitions} slot of @code{operating-system}---this is
11173 useful, for instance, if the codeset could not be inferred from the
11174 locale name. The default set of locale definitions includes some widely
11175 used locales, but not all the available locales, in order to save space.
11177 For instance, to add the North Frisian locale for Germany, the value of
11181 (cons (locale-definition
11182 (name "fy_DE.utf8") (source "fy_DE"))
11183 %default-locale-definitions)
11186 Likewise, to save space, one might want @code{locale-definitions} to
11187 list only the locales that are actually used, as in:
11190 (list (locale-definition
11191 (name "ja_JP.eucjp") (source "ja_JP")
11192 (charset "EUC-JP")))
11196 The compiled locale definitions are available at
11197 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
11198 version, which is the default location where the GNU@tie{}libc provided
11199 by Guix looks for locale data. This can be overridden using the
11200 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
11201 @code{LOCPATH} and locale packages}).
11203 The @code{locale-definition} form is provided by the @code{(gnu system
11204 locale)} module. Details are given below.
11206 @deftp {Data Type} locale-definition
11207 This is the data type of a locale definition.
11212 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
11213 Reference Manual}, for more information on locale names.
11215 @item @code{source}
11216 The name of the source for that locale. This is typically the
11217 @code{@var{language}_@var{territory}} part of the locale name.
11219 @item @code{charset} (default: @code{"UTF-8"})
11220 The ``character set'' or ``code set'' for that locale,
11221 @uref{http://www.iana.org/assignments/character-sets, as defined by
11227 @defvr {Scheme Variable} %default-locale-definitions
11228 A list of commonly used UTF-8 locales, used as the default
11229 value of the @code{locale-definitions} field of @code{operating-system}
11232 @cindex locale name
11233 @cindex normalized codeset in locale names
11234 These locale definitions use the @dfn{normalized codeset} for the part
11235 that follows the dot in the name (@pxref{Using gettextized software,
11236 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
11237 instance it has @code{uk_UA.utf8} but @emph{not}, say,
11238 @code{uk_UA.UTF-8}.
11241 @subsection Locale Data Compatibility Considerations
11243 @cindex incompatibility, of locale data
11244 @code{operating-system} declarations provide a @code{locale-libcs} field
11245 to specify the GNU@tie{}libc packages that are used to compile locale
11246 declarations (@pxref{operating-system Reference}). ``Why would I
11247 care?'', you may ask. Well, it turns out that the binary format of
11248 locale data is occasionally incompatible from one libc version to
11251 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
11252 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
11253 For instance, a program linked against libc version 2.21 is unable to
11254 read locale data produced with libc 2.22; worse, that program
11255 @emph{aborts} instead of simply ignoring the incompatible locale
11256 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
11257 the incompatible locale data, which is already an improvement.}.
11258 Similarly, a program linked against libc 2.22 can read most, but not
11259 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
11260 data is incompatible); thus calls to @code{setlocale} may fail, but
11261 programs will not abort.
11263 The ``problem'' with Guix is that users have a lot of freedom: They can
11264 choose whether and when to upgrade software in their profiles, and might
11265 be using a libc version different from the one the system administrator
11266 used to build the system-wide locale data.
11268 Fortunately, unprivileged users can also install their own locale data
11269 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
11270 @code{GUIX_LOCPATH} and locale packages}).
11272 Still, it is best if the system-wide locale data at
11273 @file{/run/current-system/locale} is built for all the libc versions
11274 actually in use on the system, so that all the programs can access
11275 it---this is especially crucial on a multi-user system. To do that, the
11276 administrator can specify several libc packages in the
11277 @code{locale-libcs} field of @code{operating-system}:
11280 (use-package-modules base)
11284 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
11287 This example would lead to a system containing locale definitions for
11288 both libc 2.21 and the current version of libc in
11289 @file{/run/current-system/locale}.
11295 @cindex system services
11296 An important part of preparing an @code{operating-system} declaration is
11297 listing @dfn{system services} and their configuration (@pxref{Using the
11298 Configuration System}). System services are typically daemons launched
11299 when the system boots, or other actions needed at that time---e.g.,
11300 configuring network access.
11302 Guix has a broad definition of ``service'' (@pxref{Service
11303 Composition}), but many services are managed by the GNU@tie{}Shepherd
11304 (@pxref{Shepherd Services}). On a running system, the @command{herd}
11305 command allows you to list the available services, show their status,
11306 start and stop them, or do other specific operations (@pxref{Jump
11307 Start,,, shepherd, The GNU Shepherd Manual}). For example:
11313 The above command, run as @code{root}, lists the currently defined
11314 services. The @command{herd doc} command shows a synopsis of the given
11315 service and its associated actions:
11319 Run libc's name service cache daemon (nscd).
11321 # herd doc nscd action invalidate
11322 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
11325 The @command{start}, @command{stop}, and @command{restart} sub-commands
11326 have the effect you would expect. For instance, the commands below stop
11327 the nscd service and restart the Xorg display server:
11331 Service nscd has been stopped.
11332 # herd restart xorg-server
11333 Service xorg-server has been stopped.
11334 Service xorg-server has been started.
11337 The following sections document the available services, starting with
11338 the core services, that may be used in an @code{operating-system}
11342 * Base Services:: Essential system services.
11343 * Scheduled Job Execution:: The mcron service.
11344 * Log Rotation:: The rottlog service.
11345 * Networking Services:: Network setup, SSH daemon, etc.
11346 * X Window:: Graphical display.
11347 * Printing Services:: Local and remote printer support.
11348 * Desktop Services:: D-Bus and desktop services.
11349 * Sound Services:: ALSA and Pulseaudio services.
11350 * Database Services:: SQL databases, key-value stores, etc.
11351 * Mail Services:: IMAP, POP3, SMTP, and all that.
11352 * Messaging Services:: Messaging services.
11353 * Telephony Services:: Telephony services.
11354 * Monitoring Services:: Monitoring services.
11355 * Kerberos Services:: Kerberos services.
11356 * LDAP Services:: LDAP services.
11357 * Web Services:: Web servers.
11358 * Certificate Services:: TLS certificates via Let's Encrypt.
11359 * DNS Services:: DNS daemons.
11360 * VPN Services:: VPN daemons.
11361 * Network File System:: NFS related services.
11362 * Continuous Integration:: The Cuirass service.
11363 * Power Management Services:: Extending battery life.
11364 * Audio Services:: The MPD.
11365 * Virtualization Services:: Virtualization services.
11366 * Version Control Services:: Providing remote access to Git repositories.
11367 * Game Services:: Game servers.
11368 * Miscellaneous Services:: Other services.
11371 @node Base Services
11372 @subsection Base Services
11374 The @code{(gnu services base)} module provides definitions for the basic
11375 services that one expects from the system. The services exported by
11376 this module are listed below.
11378 @defvr {Scheme Variable} %base-services
11379 This variable contains a list of basic services (@pxref{Service Types
11380 and Services}, for more information on service objects) one would
11381 expect from the system: a login service (mingetty) on each tty, syslogd,
11382 the libc name service cache daemon (nscd), the udev device manager, and
11385 This is the default value of the @code{services} field of
11386 @code{operating-system} declarations. Usually, when customizing a
11387 system, you will want to append services to @var{%base-services}, like
11391 (append (list (service avahi-service-type)
11392 (service openssh-service-type))
11397 @defvr {Scheme Variable} special-files-service-type
11398 This is the service that sets up ``special files'' such as
11399 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
11401 The value associated with @code{special-files-service-type} services
11402 must be a list of tuples where the first element is the ``special file''
11403 and the second element is its target. By default it is:
11405 @cindex @file{/bin/sh}
11406 @cindex @file{sh}, in @file{/bin}
11408 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
11411 @cindex @file{/usr/bin/env}
11412 @cindex @file{env}, in @file{/usr/bin}
11413 If you want to add, say, @code{/usr/bin/env} to your system, you can
11417 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
11418 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
11421 Since this is part of @code{%base-services}, you can use
11422 @code{modify-services} to customize the set of special files
11423 (@pxref{Service Reference, @code{modify-services}}). But the simple way
11424 to add a special file is @i{via} the @code{extra-special-file} procedure
11428 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
11429 Use @var{target} as the ``special file'' @var{file}.
11431 For example, adding the following lines to the @code{services} field of
11432 your operating system declaration leads to a @file{/usr/bin/env}
11436 (extra-special-file "/usr/bin/env"
11437 (file-append coreutils "/bin/env"))
11441 @deffn {Scheme Procedure} host-name-service @var{name}
11442 Return a service that sets the host name to @var{name}.
11445 @deffn {Scheme Procedure} login-service @var{config}
11446 Return a service to run login according to @var{config}, a
11447 @code{<login-configuration>} object, which specifies the message of the day,
11448 among other things.
11451 @deftp {Data Type} login-configuration
11452 This is the data type representing the configuration of login.
11457 @cindex message of the day
11458 A file-like object containing the ``message of the day''.
11460 @item @code{allow-empty-passwords?} (default: @code{#t})
11461 Allow empty passwords by default so that first-time users can log in when
11462 the 'root' account has just been created.
11467 @deffn {Scheme Procedure} mingetty-service @var{config}
11468 Return a service to run mingetty according to @var{config}, a
11469 @code{<mingetty-configuration>} object, which specifies the tty to run, among
11473 @deftp {Data Type} mingetty-configuration
11474 This is the data type representing the configuration of Mingetty, which
11475 provides the default implementation of virtual console log-in.
11480 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
11482 @item @code{auto-login} (default: @code{#f})
11483 When true, this field must be a string denoting the user name under
11484 which the system automatically logs in. When it is @code{#f}, a
11485 user name and password must be entered to log in.
11487 @item @code{login-program} (default: @code{#f})
11488 This must be either @code{#f}, in which case the default log-in program
11489 is used (@command{login} from the Shadow tool suite), or a gexp denoting
11490 the name of the log-in program.
11492 @item @code{login-pause?} (default: @code{#f})
11493 When set to @code{#t} in conjunction with @var{auto-login}, the user
11494 will have to press a key before the log-in shell is launched.
11496 @item @code{mingetty} (default: @var{mingetty})
11497 The Mingetty package to use.
11502 @deffn {Scheme Procedure} agetty-service @var{config}
11503 Return a service to run agetty according to @var{config}, an
11504 @code{<agetty-configuration>} object, which specifies the tty to run,
11505 among other things.
11508 @deftp {Data Type} agetty-configuration
11509 This is the data type representing the configuration of agetty, which
11510 implements virtual and serial console log-in. See the @code{agetty(8)}
11511 man page for more information.
11516 The name of the console this agetty runs on, as a string---e.g.,
11517 @code{"ttyS0"}. This argument is optional, it will default to
11518 a reasonable default serial port used by the kernel Linux.
11520 For this, if there is a value for an option @code{agetty.tty} in the kernel
11521 command line, agetty will extract the device name of the serial port
11522 from it and use that.
11524 If not and if there is a value for an option @code{console} with a tty in
11525 the Linux command line, agetty will extract the device name of the
11526 serial port from it and use that.
11528 In both cases, agetty will leave the other serial device settings
11529 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
11532 @item @code{baud-rate} (default: @code{#f})
11533 A string containing a comma-separated list of one or more baud rates, in
11536 @item @code{term} (default: @code{#f})
11537 A string containing the value used for the @code{TERM} environment
11540 @item @code{eight-bits?} (default: @code{#f})
11541 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
11544 @item @code{auto-login} (default: @code{#f})
11545 When passed a login name, as a string, the specified user will be logged
11546 in automatically without prompting for their login name or password.
11548 @item @code{no-reset?} (default: @code{#f})
11549 When @code{#t}, don't reset terminal cflags (control modes).
11551 @item @code{host} (default: @code{#f})
11552 This accepts a string containing the "login_host", which will be written
11553 into the @file{/var/run/utmpx} file.
11555 @item @code{remote?} (default: @code{#f})
11556 When set to @code{#t} in conjunction with @var{host}, this will add an
11557 @code{-r} fakehost option to the command line of the login program
11558 specified in @var{login-program}.
11560 @item @code{flow-control?} (default: @code{#f})
11561 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
11563 @item @code{no-issue?} (default: @code{#f})
11564 When set to @code{#t}, the contents of the @file{/etc/issue} file will
11565 not be displayed before presenting the login prompt.
11567 @item @code{init-string} (default: @code{#f})
11568 This accepts a string that will be sent to the tty or modem before
11569 sending anything else. It can be used to initialize a modem.
11571 @item @code{no-clear?} (default: @code{#f})
11572 When set to @code{#t}, agetty will not clear the screen before showing
11575 @item @code{login-program} (default: (file-append shadow "/bin/login"))
11576 This must be either a gexp denoting the name of a log-in program, or
11577 unset, in which case the default value is the @command{login} from the
11580 @item @code{local-line} (default: @code{#f})
11581 Control the CLOCAL line flag. This accepts one of three symbols as
11582 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
11583 the default value chosen by agetty is @code{'auto}.
11585 @item @code{extract-baud?} (default: @code{#f})
11586 When set to @code{#t}, instruct agetty to try to extract the baud rate
11587 from the status messages produced by certain types of modems.
11589 @item @code{skip-login?} (default: @code{#f})
11590 When set to @code{#t}, do not prompt the user for a login name. This
11591 can be used with @var{login-program} field to use non-standard login
11594 @item @code{no-newline?} (default: @code{#f})
11595 When set to @code{#t}, do not print a newline before printing the
11596 @file{/etc/issue} file.
11598 @c Is this dangerous only when used with login-program, or always?
11599 @item @code{login-options} (default: @code{#f})
11600 This option accepts a string containing options that are passed to the
11601 login program. When used with the @var{login-program}, be aware that a
11602 malicious user could try to enter a login name containing embedded
11603 options that could be parsed by the login program.
11605 @item @code{login-pause} (default: @code{#f})
11606 When set to @code{#t}, wait for any key before showing the login prompt.
11607 This can be used in conjunction with @var{auto-login} to save memory by
11608 lazily spawning shells.
11610 @item @code{chroot} (default: @code{#f})
11611 Change root to the specified directory. This option accepts a directory
11614 @item @code{hangup?} (default: @code{#f})
11615 Use the Linux system call @code{vhangup} to do a virtual hangup of the
11616 specified terminal.
11618 @item @code{keep-baud?} (default: @code{#f})
11619 When set to @code{#t}, try to keep the existing baud rate. The baud
11620 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
11623 @item @code{timeout} (default: @code{#f})
11624 When set to an integer value, terminate if no user name could be read
11625 within @var{timeout} seconds.
11627 @item @code{detect-case?} (default: @code{#f})
11628 When set to @code{#t}, turn on support for detecting an uppercase-only
11629 terminal. This setting will detect a login name containing only
11630 uppercase letters as indicating an uppercase-only terminal and turn on
11631 some upper-to-lower case conversions. Note that this will not support
11632 Unicode characters.
11634 @item @code{wait-cr?} (default: @code{#f})
11635 When set to @code{#t}, wait for the user or modem to send a
11636 carriage-return or linefeed character before displaying
11637 @file{/etc/issue} or login prompt. This is typically used with the
11638 @var{init-string} option.
11640 @item @code{no-hints?} (default: @code{#f})
11641 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
11644 @item @code{no-hostname?} (default: @code{#f})
11645 By default, the hostname is printed. When this option is set to
11646 @code{#t}, no hostname will be shown at all.
11648 @item @code{long-hostname?} (default: @code{#f})
11649 By default, the hostname is only printed until the first dot. When this
11650 option is set to @code{#t}, the fully qualified hostname by
11651 @code{gethostname} or @code{getaddrinfo} is shown.
11653 @item @code{erase-characters} (default: @code{#f})
11654 This option accepts a string of additional characters that should be
11655 interpreted as backspace when the user types their login name.
11657 @item @code{kill-characters} (default: @code{#f})
11658 This option accepts a string that should be interpreted to mean "ignore
11659 all previous characters" (also called a "kill" character) when the types
11662 @item @code{chdir} (default: @code{#f})
11663 This option accepts, as a string, a directory path that will be changed
11666 @item @code{delay} (default: @code{#f})
11667 This options accepts, as an integer, the number of seconds to sleep
11668 before opening the tty and displaying the login prompt.
11670 @item @code{nice} (default: @code{#f})
11671 This option accepts, as an integer, the nice value with which to run the
11672 @command{login} program.
11674 @item @code{extra-options} (default: @code{'()})
11675 This option provides an "escape hatch" for the user to provide arbitrary
11676 command-line arguments to @command{agetty} as a list of strings.
11681 @deffn {Scheme Procedure} kmscon-service-type @var{config}
11682 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
11683 according to @var{config}, a @code{<kmscon-configuration>} object, which
11684 specifies the tty to run, among other things.
11687 @deftp {Data Type} kmscon-configuration
11688 This is the data type representing the configuration of Kmscon, which
11689 implements virtual console log-in.
11693 @item @code{virtual-terminal}
11694 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
11696 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
11697 A gexp denoting the name of the log-in program. The default log-in program is
11698 @command{login} from the Shadow tool suite.
11700 @item @code{login-arguments} (default: @code{'("-p")})
11701 A list of arguments to pass to @command{login}.
11703 @item @code{auto-login} (default: @code{#f})
11704 When passed a login name, as a string, the specified user will be logged
11705 in automatically without prompting for their login name or password.
11707 @item @code{hardware-acceleration?} (default: #f)
11708 Whether to use hardware acceleration.
11710 @item @code{kmscon} (default: @var{kmscon})
11711 The Kmscon package to use.
11716 @cindex name service cache daemon
11718 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
11719 [#:name-services '()]
11720 Return a service that runs the libc name service cache daemon (nscd) with the
11721 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
11722 Service Switch}, for an example.
11724 For convenience, the Shepherd service for nscd provides the following actions:
11728 @cindex cache invalidation, nscd
11729 @cindex nscd, cache invalidation
11730 This invalidate the given cache. For instance, running:
11733 herd invalidate nscd hosts
11737 invalidates the host name lookup cache of nscd.
11740 Running @command{herd statistics nscd} displays information about nscd usage
11746 @defvr {Scheme Variable} %nscd-default-configuration
11747 This is the default @code{<nscd-configuration>} value (see below) used
11748 by @code{nscd-service}. It uses the caches defined by
11749 @var{%nscd-default-caches}; see below.
11752 @deftp {Data Type} nscd-configuration
11753 This is the data type representing the name service cache daemon (nscd)
11758 @item @code{name-services} (default: @code{'()})
11759 List of packages denoting @dfn{name services} that must be visible to
11760 the nscd---e.g., @code{(list @var{nss-mdns})}.
11762 @item @code{glibc} (default: @var{glibc})
11763 Package object denoting the GNU C Library providing the @command{nscd}
11766 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
11767 Name of the nscd log file. This is where debugging output goes when
11768 @code{debug-level} is strictly positive.
11770 @item @code{debug-level} (default: @code{0})
11771 Integer denoting the debugging levels. Higher numbers mean that more
11772 debugging output is logged.
11774 @item @code{caches} (default: @var{%nscd-default-caches})
11775 List of @code{<nscd-cache>} objects denoting things to be cached; see
11781 @deftp {Data Type} nscd-cache
11782 Data type representing a cache database of nscd and its parameters.
11786 @item @code{database}
11787 This is a symbol representing the name of the database to be cached.
11788 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
11789 @code{services}, which designate the corresponding NSS database
11790 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
11792 @item @code{positive-time-to-live}
11793 @itemx @code{negative-time-to-live} (default: @code{20})
11794 A number representing the number of seconds during which a positive or
11795 negative lookup result remains in cache.
11797 @item @code{check-files?} (default: @code{#t})
11798 Whether to check for updates of the files corresponding to
11801 For instance, when @var{database} is @code{hosts}, setting this flag
11802 instructs nscd to check for updates in @file{/etc/hosts} and to take
11805 @item @code{persistent?} (default: @code{#t})
11806 Whether the cache should be stored persistently on disk.
11808 @item @code{shared?} (default: @code{#t})
11809 Whether the cache should be shared among users.
11811 @item @code{max-database-size} (default: 32@tie{}MiB)
11812 Maximum size in bytes of the database cache.
11814 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
11815 @c settings, so leave them out.
11820 @defvr {Scheme Variable} %nscd-default-caches
11821 List of @code{<nscd-cache>} objects used by default by
11822 @code{nscd-configuration} (see above).
11824 It enables persistent and aggressive caching of service and host name
11825 lookups. The latter provides better host name lookup performance,
11826 resilience in the face of unreliable name servers, and also better
11827 privacy---often the result of host name lookups is in local cache, so
11828 external name servers do not even need to be queried.
11831 @anchor{syslog-configuration-type}
11834 @deftp {Data Type} syslog-configuration
11835 This data type represents the configuration of the syslog daemon.
11838 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
11839 The syslog daemon to use.
11841 @item @code{config-file} (default: @code{%default-syslog.conf})
11842 The syslog configuration file to use.
11847 @anchor{syslog-service}
11849 @deffn {Scheme Procedure} syslog-service @var{config}
11850 Return a service that runs a syslog daemon according to @var{config}.
11852 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
11853 information on the configuration file syntax.
11856 @defvr {Scheme Variable} guix-service-type
11857 This is the type of the service that runs the build daemon,
11858 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
11859 @code{guix-configuration} record as described below.
11862 @anchor{guix-configuration-type}
11863 @deftp {Data Type} guix-configuration
11864 This data type represents the configuration of the Guix build daemon.
11865 @xref{Invoking guix-daemon}, for more information.
11868 @item @code{guix} (default: @var{guix})
11869 The Guix package to use.
11871 @item @code{build-group} (default: @code{"guixbuild"})
11872 Name of the group for build user accounts.
11874 @item @code{build-accounts} (default: @code{10})
11875 Number of build user accounts to create.
11877 @item @code{authorize-key?} (default: @code{#t})
11878 @cindex substitutes, authorization thereof
11879 Whether to authorize the substitute keys listed in
11880 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
11881 (@pxref{Substitutes}).
11883 @vindex %default-authorized-guix-keys
11884 @item @code{authorized-keys} (default: @var{%default-authorized-guix-keys})
11885 The list of authorized key files for archive imports, as a list of
11886 string-valued gexps (@pxref{Invoking guix archive}). By default, it
11887 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
11889 @item @code{use-substitutes?} (default: @code{#t})
11890 Whether to use substitutes.
11892 @item @code{substitute-urls} (default: @var{%default-substitute-urls})
11893 The list of URLs where to look for substitutes by default.
11895 @item @code{max-silent-time} (default: @code{0})
11896 @itemx @code{timeout} (default: @code{0})
11897 The number of seconds of silence and the number of seconds of activity,
11898 respectively, after which a build process times out. A value of zero
11899 disables the timeout.
11901 @item @code{log-compression} (default: @code{'bzip2})
11902 The type of compression used for build logs---one of @code{gzip},
11903 @code{bzip2}, or @code{none}.
11905 @item @code{extra-options} (default: @code{'()})
11906 List of extra command-line options for @command{guix-daemon}.
11908 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
11909 File where @command{guix-daemon}'s standard output and standard error
11912 @item @code{http-proxy} (default: @code{#f})
11913 The HTTP proxy used for downloading fixed-output derivations and
11916 @item @code{tmpdir} (default: @code{#f})
11917 A directory path where the @command{guix-daemon} will perform builds.
11922 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
11923 Run @var{udev}, which populates the @file{/dev} directory dynamically.
11924 udev rules can be provided as a list of files through the @var{rules}
11925 variable. The procedures @var{udev-rule} and @var{file->udev-rule} from
11926 @code{(gnu services base)} simplify the creation of such rule files.
11929 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
11930 Return a udev-rule file named @var{file-name} containing the rules
11931 defined by the @var{contents} literal.
11933 In the following example, a rule for a USB device is defined to be
11934 stored in the file @file{90-usb-thing.rules}. The rule runs a script
11935 upon detecting a USB device with a given product identifier.
11938 (define %example-udev-rule
11940 "90-usb-thing.rules"
11941 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
11942 "ATTR@{product@}==\"Example\", "
11943 "RUN+=\"/path/to/script\"")))
11946 The @command{herd rules udev} command, as root, returns the name of the
11947 directory containing all the active udev rules.
11950 Here we show how the default @var{udev-service} can be extended with it.
11956 (modify-services %desktop-services
11957 (udev-service-type config =>
11958 (udev-configuration (inherit config)
11959 (rules (append (udev-configuration-rules config)
11960 (list %example-udev-rule))))))))
11963 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
11964 Return a udev file named @var{file-name} containing the rules defined
11965 within @var{file}, a file-like object.
11967 The following example showcases how we can use an existing rule file.
11970 (use-modules (guix download) ;for url-fetch
11971 (guix packages) ;for origin
11974 (define %android-udev-rules
11976 "51-android-udev.rules"
11977 (let ((version "20170910"))
11980 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
11981 "android-udev-rules/" version "/51-android.rules"))
11983 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
11987 Additionally, Guix package definitions can be included in @var{rules} in
11988 order to extend the udev rules with the definitions found under their
11989 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
11990 @var{file->udev-rule} example, we could have used the
11991 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
11992 packages android)} module.
11994 The following example shows how to use the @var{android-udev-rules}
11995 package so that the Android tool @command{adb} can detect devices
11996 without root privileges. It also details how to create the
11997 @code{adbusers} group, which is required for the proper functioning of
11998 the rules defined within the @var{android-udev-rules} package. To
11999 create such a group, we must define it both as part of the
12000 @var{supplementary-groups} of our @var{user-account} declaration, as
12001 well as in the @var{groups} field of the @var{operating-system} record.
12004 (use-modules (gnu packages android) ;for android-udev-rules
12005 (gnu system shadow) ;for user-group
12010 (users (cons (user-acount
12012 (supplementary-groups
12013 '("adbusers" ;for adb
12014 "wheel" "netdev" "audio" "video"))
12017 (groups (cons (user-group (system? #t) (name "adbusers"))
12023 (modify-services %desktop-services
12026 (udev-configuration (inherit config)
12027 (rules (cons android-udev-rules
12028 (udev-configuration-rules config))))))))
12031 @defvr {Scheme Variable} urandom-seed-service-type
12032 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
12033 when rebooting. It also tries to seed @file{/dev/urandom} from
12034 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
12038 @defvr {Scheme Variable} %random-seed-file
12039 This is the name of the file where some random bytes are saved by
12040 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
12041 It defaults to @file{/var/lib/random-seed}.
12046 @defvr {Scheme Variable} gpm-service-type
12047 This is the type of the service that runs GPM, the @dfn{general-purpose
12048 mouse daemon}, which provides mouse support to the Linux console. GPM
12049 allows users to use the mouse in the console, notably to select, copy,
12052 The value for services of this type must be a @code{gpm-configuration}
12053 (see below). This service is not part of @var{%base-services}.
12056 @deftp {Data Type} gpm-configuration
12057 Data type representing the configuration of GPM.
12060 @item @code{options} (default: @code{%default-gpm-options})
12061 Command-line options passed to @command{gpm}. The default set of
12062 options instruct @command{gpm} to listen to mouse events on
12063 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
12066 @item @code{gpm} (default: @code{gpm})
12067 The GPM package to use.
12072 @anchor{guix-publish-service-type}
12073 @deffn {Scheme Variable} guix-publish-service-type
12074 This is the service type for @command{guix publish} (@pxref{Invoking
12075 guix publish}). Its value must be a @code{guix-configuration}
12076 object, as described below.
12078 This assumes that @file{/etc/guix} already contains a signing key pair as
12079 created by @command{guix archive --generate-key} (@pxref{Invoking guix
12080 archive}). If that is not the case, the service will fail to start.
12083 @deftp {Data Type} guix-publish-configuration
12084 Data type representing the configuration of the @code{guix publish}
12088 @item @code{guix} (default: @code{guix})
12089 The Guix package to use.
12091 @item @code{port} (default: @code{80})
12092 The TCP port to listen for connections.
12094 @item @code{host} (default: @code{"localhost"})
12095 The host (and thus, network interface) to listen to. Use
12096 @code{"0.0.0.0"} to listen on all the network interfaces.
12098 @item @code{compression-level} (default: @code{3})
12099 The gzip compression level at which substitutes are compressed. Use
12100 @code{0} to disable compression altogether, and @code{9} to get the best
12101 compression ratio at the expense of increased CPU usage.
12103 @item @code{nar-path} (default: @code{"nar"})
12104 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
12105 publish, @code{--nar-path}}, for details.
12107 @item @code{cache} (default: @code{#f})
12108 When it is @code{#f}, disable caching and instead generate archives on
12109 demand. Otherwise, this should be the name of a directory---e.g.,
12110 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
12111 archives and meta-data ready to be sent. @xref{Invoking guix publish,
12112 @option{--cache}}, for more information on the tradeoffs involved.
12114 @item @code{workers} (default: @code{#f})
12115 When it is an integer, this is the number of worker threads used for
12116 caching; when @code{#f}, the number of processors is used.
12117 @xref{Invoking guix publish, @option{--workers}}, for more information.
12119 @item @code{ttl} (default: @code{#f})
12120 When it is an integer, this denotes the @dfn{time-to-live} in seconds
12121 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
12122 for more information.
12126 @anchor{rngd-service}
12127 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
12128 [#:device "/dev/hwrng"]
12129 Return a service that runs the @command{rngd} program from @var{rng-tools}
12130 to add @var{device} to the kernel's entropy pool. The service will fail if
12131 @var{device} does not exist.
12134 @anchor{pam-limits-service}
12135 @cindex session limits
12140 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
12142 Return a service that installs a configuration file for the
12143 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
12144 @code{pam_limits} module}. The procedure optionally takes a list of
12145 @code{pam-limits-entry} values, which can be used to specify
12146 @code{ulimit} limits and nice priority limits to user sessions.
12148 The following limits definition sets two hard and soft limits for all
12149 login sessions of users in the @code{realtime} group:
12152 (pam-limits-service
12154 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
12155 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
12158 The first entry increases the maximum realtime priority for
12159 non-privileged processes; the second entry lifts any restriction of the
12160 maximum address space that can be locked in memory. These settings are
12161 commonly used for real-time audio systems.
12164 @node Scheduled Job Execution
12165 @subsection Scheduled Job Execution
12169 @cindex scheduling jobs
12170 The @code{(gnu services mcron)} module provides an interface to
12171 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
12172 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
12173 Unix @command{cron} daemon; the main difference is that it is
12174 implemented in Guile Scheme, which provides a lot of flexibility when
12175 specifying the scheduling of jobs and their actions.
12177 The example below defines an operating system that runs the
12178 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
12179 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
12180 well as the @command{mkid} command on behalf of an unprivileged user
12181 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
12182 gexps to introduce job definitions that are passed to mcron
12183 (@pxref{G-Expressions}).
12186 (use-modules (guix) (gnu) (gnu services mcron))
12187 (use-package-modules base idutils)
12189 (define updatedb-job
12190 ;; Run 'updatedb' at 3AM every day. Here we write the
12191 ;; job's action as a Scheme procedure.
12192 #~(job '(next-hour '(3))
12194 (execl (string-append #$findutils "/bin/updatedb")
12196 "--prunepaths=/tmp /var/tmp /gnu/store"))))
12198 (define garbage-collector-job
12199 ;; Collect garbage 5 minutes after midnight every day.
12200 ;; The job's action is a shell command.
12201 #~(job "5 0 * * *" ;Vixie cron syntax
12204 (define idutils-job
12205 ;; Update the index database as user "charlie" at 12:15PM
12206 ;; and 19:15PM. This runs from the user's home directory.
12207 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
12208 (string-append #$idutils "/bin/mkid src")
12213 (services (cons (service mcron-service-type
12214 (mcron-configuration
12215 (jobs (list garbage-collector-job
12221 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
12222 for more information on mcron job specifications. Below is the
12223 reference of the mcron service.
12225 On a running system, you can use the @code{schedule} action of the service to
12226 visualize the mcron jobs that will be executed next:
12229 # herd schedule mcron
12233 The example above lists the next five tasks that will be executed, but you can
12234 also specify the number of tasks to display:
12237 # herd schedule mcron 10
12240 @defvr {Scheme Variable} mcron-service-type
12241 This is the type of the @code{mcron} service, whose value is an
12242 @code{mcron-configuration} object.
12244 This service type can be the target of a service extension that provides
12245 it additional job specifications (@pxref{Service Composition}). In
12246 other words, it is possible to define services that provide additional
12250 @deftp {Data Type} mcron-configuration
12251 Data type representing the configuration of mcron.
12254 @item @code{mcron} (default: @var{mcron})
12255 The mcron package to use.
12258 This is a list of gexps (@pxref{G-Expressions}), where each gexp
12259 corresponds to an mcron job specification (@pxref{Syntax, mcron job
12260 specifications,, mcron, GNU@tie{}mcron}).
12266 @subsection Log Rotation
12269 @cindex log rotation
12271 Log files such as those found in @file{/var/log} tend to grow endlessly,
12272 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
12273 their contents in separate files, possibly compressed. The @code{(gnu
12274 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
12275 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
12277 The example below defines an operating system that provides log rotation
12278 with the default settings, for commonly encountered log files.
12281 (use-modules (guix) (gnu))
12282 (use-service-modules admin mcron)
12283 (use-package-modules base idutils)
12287 (services (cons (service rottlog-service-type)
12291 @defvr {Scheme Variable} rottlog-service-type
12292 This is the type of the Rottlog service, whose value is a
12293 @code{rottlog-configuration} object.
12295 Other services can extend this one with new @code{log-rotation} objects
12296 (see below), thereby augmenting the set of files to be rotated.
12298 This service type can define mcron jobs (@pxref{Scheduled Job
12299 Execution}) to run the rottlog service.
12302 @deftp {Data Type} rottlog-configuration
12303 Data type representing the configuration of rottlog.
12306 @item @code{rottlog} (default: @code{rottlog})
12307 The Rottlog package to use.
12309 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
12310 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
12311 rottlog, GNU Rot[t]log Manual}).
12313 @item @code{rotations} (default: @code{%default-rotations})
12314 A list of @code{log-rotation} objects as defined below.
12317 This is a list of gexps where each gexp corresponds to an mcron job
12318 specification (@pxref{Scheduled Job Execution}).
12322 @deftp {Data Type} log-rotation
12323 Data type representing the rotation of a group of log files.
12325 Taking an example from the Rottlog manual (@pxref{Period Related File
12326 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
12332 (files '("/var/log/apache/*"))
12333 (options '("storedir apache-archives"
12339 The list of fields is as follows:
12342 @item @code{frequency} (default: @code{'weekly})
12343 The log rotation frequency, a symbol.
12346 The list of files or file glob patterns to rotate.
12348 @item @code{options} (default: @code{'()})
12349 The list of rottlog options for this rotation (@pxref{Configuration
12350 parameters,,, rottlog, GNU Rot[t]lg Manual}).
12352 @item @code{post-rotate} (default: @code{#f})
12353 Either @code{#f} or a gexp to execute once the rotation has completed.
12357 @defvr {Scheme Variable} %default-rotations
12358 Specifies weekly rotation of @var{%rotated-files} and
12359 a couple of other files.
12362 @defvr {Scheme Variable} %rotated-files
12363 The list of syslog-controlled files to be rotated. By default it is:
12364 @code{'("/var/log/messages" "/var/log/secure")}.
12367 @node Networking Services
12368 @subsection Networking Services
12370 The @code{(gnu services networking)} module provides services to configure
12371 the network interface.
12373 @cindex DHCP, networking service
12374 @defvr {Scheme Variable} dhcp-client-service-type
12375 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
12376 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
12377 is the DHCP client package to use, @code{isc-dhcp} by default.
12380 @deffn {Scheme Procedure} dhcpd-service-type
12381 This type defines a service that runs a DHCP daemon. To create a
12382 service of this type, you must supply a @code{<dhcpd-configuration>}.
12386 (service dhcpd-service-type
12387 (dhcpd-configuration
12388 (config-file (local-file "my-dhcpd.conf"))
12389 (interfaces '("enp0s25"))))
12393 @deftp {Data Type} dhcpd-configuration
12395 @item @code{package} (default: @code{isc-dhcp})
12396 The package that provides the DHCP daemon. This package is expected to
12397 provide the daemon at @file{sbin/dhcpd} relative to its output
12398 directory. The default package is the
12399 @uref{http://www.isc.org/products/DHCP, ISC's DHCP server}.
12400 @item @code{config-file} (default: @code{#f})
12401 The configuration file to use. This is required. It will be passed to
12402 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
12403 object (@pxref{G-Expressions, file-like objects}). See @code{man
12404 dhcpd.conf} for details on the configuration file syntax.
12405 @item @code{version} (default: @code{"4"})
12406 The DHCP version to use. The ISC DHCP server supports the values ``4'',
12407 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
12408 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
12410 @item @code{run-directory} (default: @code{"/run/dhcpd"})
12411 The run directory to use. At service activation time, this directory
12412 will be created if it does not exist.
12413 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
12414 The PID file to use. This corresponds to the @code{-pf} option of
12415 @code{dhcpd}. See @code{man dhcpd} for details.
12416 @item @code{interfaces} (default: @code{'()})
12417 The names of the network interfaces on which dhcpd should listen for
12418 broadcasts. If this list is not empty, then its elements (which must be
12419 strings) will be appended to the @code{dhcpd} invocation when starting
12420 the daemon. It may not be necessary to explicitly specify any
12421 interfaces here; see @code{man dhcpd} for details.
12425 @defvr {Scheme Variable} static-networking-service-type
12426 This is the type for statically-configured network interfaces.
12427 @c TODO Document <static-networking> data structures.
12430 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
12431 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
12432 [#:requirement @code{'(udev)}]
12433 Return a service that starts @var{interface} with address @var{ip}. If
12434 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
12435 it must be a string specifying the default network gateway. @var{requirement}
12436 can be used to declare a dependency on another service before configuring the
12439 This procedure can be called several times, one for each network
12440 interface of interest. Behind the scenes what it does is extend
12441 @code{static-networking-service-type} with additional network interfaces
12447 (static-networking-service "eno1" "192.168.1.82"
12448 #:gateway "192.168.1.2"
12449 #:name-servers '("192.168.1.2"))
12456 @cindex network management
12457 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
12458 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
12459 management daemon that aims to simplify wired and wireless networking.
12461 This service adds the @var{wicd} package to the global profile, providing
12462 several commands to interact with the daemon and configure networking:
12463 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
12464 and @command{wicd-curses} user interfaces.
12467 @cindex ModemManager
12469 @defvr {Scheme Variable} modem-manager-service-type
12470 This is the service type for the
12471 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
12472 service. The value for this service type is a
12473 @code{modem-manager-configuration} record.
12475 This service is part of @code{%desktop-services} (@pxref{Desktop
12479 @deftp {Data Type} modem-manager-configuration
12480 Data type representing the configuration of ModemManager.
12483 @item @code{modem-manager} (default: @code{modem-manager})
12484 The ModemManager package to use.
12489 @cindex NetworkManager
12491 @defvr {Scheme Variable} network-manager-service-type
12492 This is the service type for the
12493 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
12494 service. The value for this service type is a
12495 @code{network-manager-configuration} record.
12497 This service is part of @code{%desktop-services} (@pxref{Desktop
12501 @deftp {Data Type} network-manager-configuration
12502 Data type representing the configuration of NetworkManager.
12505 @item @code{network-manager} (default: @code{network-manager})
12506 The NetworkManager package to use.
12508 @item @code{dns} (default: @code{"default"})
12509 Processing mode for DNS, which affects how NetworkManager uses the
12510 @code{resolv.conf} configuration file.
12514 NetworkManager will update @code{resolv.conf} to reflect the nameservers
12515 provided by currently active connections.
12518 NetworkManager will run @code{dnsmasq} as a local caching nameserver,
12519 using a "split DNS" configuration if you are connected to a VPN, and
12520 then update @code{resolv.conf} to point to the local nameserver.
12523 NetworkManager will not modify @code{resolv.conf}.
12526 @item @code{vpn-plugins} (default: @code{'()})
12527 This is the list of available plugins for virtual private networks
12528 (VPNs). An example of this is the @code{network-manager-openvpn}
12529 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
12535 @deffn {Scheme Variable} connman-service-type
12536 This is the service type to run @url{https://01.org/connman,Connman},
12537 a network connection manager.
12539 Its value must be an
12540 @code{connman-configuration} record as in this example:
12543 (service connman-service-type
12544 (connman-configuration
12545 (disable-vpn? #t)))
12548 See below for details about @code{connman-configuration}.
12551 @deftp {Data Type} connman-configuration
12552 Data Type representing the configuration of connman.
12555 @item @code{connman} (default: @var{connman})
12556 The connman package to use.
12558 @item @code{disable-vpn?} (default: @code{#f})
12559 When true, disable connman's vpn plugin.
12563 @cindex WPA Supplicant
12564 @defvr {Scheme Variable} wpa-supplicant-service-type
12565 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
12566 supplicant}, an authentication daemon required to authenticate against
12567 encrypted WiFi or ethernet networks.
12570 @deftp {Data Type} wpa-supplicant-configuration
12571 Data type representing the configuration of WPA Supplicant.
12573 It takes the following parameters:
12576 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
12577 The WPA Supplicant package to use.
12579 @item @code{dbus?} (default: @code{#t})
12580 Whether to listen for requests on D-Bus.
12582 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
12583 Where to store the PID file.
12585 @item @code{interface} (default: @code{#f})
12586 If this is set, it must specify the name of a network interface that
12587 WPA supplicant will control.
12589 @item @code{config-file} (default: @code{#f})
12590 Optional configuration file to use.
12592 @item @code{extra-options} (default: @code{'()})
12593 List of additional command-line arguments to pass to the daemon.
12598 @defvr {Scheme Variable} iptables-service-type
12599 This is the service type to set up an iptables configuration. iptables is a
12600 packet filtering framework supported by the Linux kernel. This service
12601 supports configuring iptables for both IPv4 and IPv6. A simple example
12602 configuration rejecting all incoming connections except those to the ssh port
12606 (service iptables-service-type
12607 (iptables-configuration
12608 (ipv4-rules (plain-file "iptables.rules" "*filter
12612 -A INPUT -p tcp --dport 22 -j ACCEPT
12613 -A INPUT -j REJECT --reject-with icmp-port-unreachable
12616 (ipv6-rules (plain-file "ip6tables.rules" "*filter
12620 -A INPUT -p tcp --dport 22 -j ACCEPT
12621 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
12627 @deftp {Data Type} iptables-configuration
12628 The data type representing the configuration of iptables.
12631 @item @code{iptables} (default: @code{iptables})
12632 The iptables package that provides @code{iptables-restore} and
12633 @code{ip6tables-restore}.
12634 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
12635 The iptables rules to use. It will be passed to @code{iptables-restore}.
12636 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12638 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
12639 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
12640 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12645 @cindex NTP (Network Time Protocol), service
12646 @cindex real time clock
12647 @defvr {Scheme Variable} ntp-service-type
12648 This is the type of the service running the @uref{http://www.ntp.org,
12649 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
12650 system clock synchronized with that of the specified NTP servers.
12652 The value of this service is an @code{ntpd-configuration} object, as described
12656 @deftp {Data Type} ntp-configuration
12657 This is the data type for the NTP service configuration.
12660 @item @code{servers} (default: @code{%ntp-servers})
12661 This is the list of servers (host names) with which @command{ntpd} will be
12664 @item @code{allow-large-adjustment?} (default: @code{#f})
12665 This determines whether @command{ntpd} is allowed to make an initial
12666 adjustment of more than 1,000 seconds.
12668 @item @code{ntp} (default: @code{ntp})
12669 The NTP package to use.
12673 @defvr {Scheme Variable} %ntp-servers
12674 List of host names used as the default NTP servers. These are servers of the
12675 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
12679 @deffn {Scheme Procedure} openntpd-service-type
12680 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
12681 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
12682 clock synchronized with that of the given servers.
12686 openntpd-service-type
12687 (openntpd-configuration
12688 (listen-on '("127.0.0.1" "::1"))
12689 (sensor '("udcf0 correction 70000"))
12690 (constraint-from '("www.gnu.org"))
12691 (constraints-from '("https://www.google.com/"))
12692 (allow-large-adjustment? #t)))
12697 @deftp {Data Type} openntpd-configuration
12699 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
12700 The openntpd executable to use.
12701 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
12702 A list of local IP addresses or hostnames the ntpd daemon should listen on.
12703 @item @code{query-from} (default: @code{'()})
12704 A list of local IP address the ntpd daemon should use for outgoing queries.
12705 @item @code{sensor} (default: @code{'()})
12706 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
12707 will listen to each sensor that acutally exists and ignore non-existant ones.
12708 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
12710 @item @code{server} (default: @var{%ntp-servers})
12711 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
12712 @item @code{servers} (default: @code{'()})
12713 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
12714 @item @code{constraint-from} (default: @code{'()})
12715 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
12716 This time information is not used for precision but acts as an authenticated
12717 constraint, thereby reducing the impact of unauthenticated NTP
12718 man-in-the-middle attacks.
12719 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
12721 @item @code{constraints-from} (default: @code{'()})
12722 As with constraint from, specify a list of URLs, IP addresses or hostnames of
12723 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
12724 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
12725 @item @code{allow-large-adjustment?} (default: @code{#f})
12726 Determines if @code{ntpd} is allowed to make an initial adjustment of more
12732 @deffn {Scheme variable} inetd-service-type
12733 This service runs the @command{inetd} (@pxref{inetd invocation,,,
12734 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
12735 connections on internet sockets, and lazily starts the specified server
12736 program when a connection is made on one of these sockets.
12738 The value of this service is an @code{inetd-configuration} object. The
12739 following example configures the @command{inetd} daemon to provide the
12740 built-in @command{echo} service, as well as an smtp service which
12741 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
12742 gateway @code{hostname}:
12747 (inetd-configuration
12751 (socket-type 'stream)
12758 (socket-type 'stream)
12762 (program (file-append openssh "/bin/ssh"))
12764 '("ssh" "-qT" "-i" "/path/to/ssh_key"
12765 "-W" "smtp-server:25" "user@@hostname")))))
12768 See below for more details about @code{inetd-configuration}.
12771 @deftp {Data Type} inetd-configuration
12772 Data type representing the configuration of @command{inetd}.
12775 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
12776 The @command{inetd} executable to use.
12778 @item @code{entries} (default: @code{'()})
12779 A list of @command{inetd} service entries. Each entry should be created
12780 by the @code{inetd-entry} constructor.
12784 @deftp {Data Type} inetd-entry
12785 Data type representing an entry in the @command{inetd} configuration.
12786 Each entry corresponds to a socket where @command{inetd} will listen for
12790 @item @code{node} (default: @code{#f})
12791 Optional string, a comma-separated list of local addresses
12792 @command{inetd} should use when listening for this service.
12793 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
12794 description of all options.
12796 A string, the name must correspond to an entry in @code{/etc/services}.
12797 @item @code{socket-type}
12798 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
12800 @item @code{protocol}
12801 A string, must correspond to an entry in @code{/etc/protocols}.
12802 @item @code{wait?} (default: @code{#t})
12803 Whether @command{inetd} should wait for the server to exit before
12804 listening to new service requests.
12806 A string containing the user (and, optionally, group) name of the user
12807 as whom the server should run. The group name can be specified in a
12808 suffix, separated by a colon or period, i.e.@: @code{"user"},
12809 @code{"user:group"} or @code{"user.group"}.
12810 @item @code{program} (default: @code{"internal"})
12811 The server program which will serve the requests, or @code{"internal"}
12812 if @command{inetd} should use a built-in service.
12813 @item @code{arguments} (default: @code{'()})
12814 A list strings or file-like objects, which are the server program's
12815 arguments, starting with the zeroth argument, i.e.@: the name of the
12816 program itself. For @command{inetd}'s internal services, this entry
12817 must be @code{'()} or @code{'("internal")}.
12820 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
12821 detailed discussion of each configuration field.
12825 @defvr {Scheme Variable} tor-service-type
12826 This is the type for a service that runs the @uref{https://torproject.org,
12827 Tor} anonymous networking daemon. The service is configured using a
12828 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
12829 @code{tor} unprivileged user, which is a member of the @code{tor} group.
12833 @deftp {Data Type} tor-configuration
12835 @item @code{tor} (default: @code{tor})
12836 The package that provides the Tor daemon. This package is expected to provide
12837 the daemon at @file{bin/tor} relative to its output directory. The default
12838 package is the @uref{https://www.torproject.org, Tor Project's}
12841 @item @code{config-file} (default: @code{(plain-file "empty" "")})
12842 The configuration file to use. It will be appended to a default configuration
12843 file, and the final configuration file will be passed to @code{tor} via its
12844 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
12845 file-like objects}). See @code{man tor} for details on the configuration file
12848 @item @code{hidden-services} (default: @code{'()})
12849 The list of @code{<hidden-service>} records to use. For any hidden service
12850 you include in this list, appropriate configuration to enable the hidden
12851 service will be automatically added to the default configuration file. You
12852 may conveniently create @code{<hidden-service>} records using the
12853 @code{tor-hidden-service} procedure described below.
12855 @item @code{socks-socket-type} (default: @code{'tcp})
12856 The default socket type that Tor should use for its SOCKS socket. This must
12857 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
12858 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
12859 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
12860 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
12863 If you want to customize the SOCKS socket in more detail, leave
12864 @code{socks-socket-type} at its default value of @code{'tcp} and use
12865 @code{config-file} to override the default by providing your own
12866 @code{SocksPort} option.
12870 @cindex hidden service
12871 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
12872 Define a new Tor @dfn{hidden service} called @var{name} and implementing
12873 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
12876 '((22 "127.0.0.1:22")
12877 (80 "127.0.0.1:8080"))
12880 In this example, port 22 of the hidden service is mapped to local port 22, and
12881 port 80 is mapped to local port 8080.
12883 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
12884 the @file{hostname} file contains the @code{.onion} host name for the hidden
12887 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
12888 project's documentation} for more information.
12891 The @code{(gnu services rsync)} module provides the following services:
12893 You might want an rsync daemon if you have files that you want available
12894 so anyone (or just yourself) can download existing files or upload new
12897 @deffn {Scheme Variable} rsync-service-type
12898 This is the type for the @uref{https://rsync.samba.org, rsync} rsync daemon,
12899 @command{rsync-configuration} record as in this example:
12902 (service rsync-service-type)
12905 See below for details about @code{rsync-configuration}.
12908 @deftp {Data Type} rsync-configuration
12909 Data type representing the configuration for @code{rsync-service}.
12912 @item @code{package} (default: @var{rsync})
12913 @code{rsync} package to use.
12915 @item @code{port-number} (default: @code{873})
12916 TCP port on which @command{rsync} listens for incoming connections. If port
12917 is less than @code{1024} @command{rsync} needs to be started as the
12918 @code{root} user and group.
12920 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
12921 Name of the file where @command{rsync} writes its PID.
12923 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
12924 Name of the file where @command{rsync} writes its lock file.
12926 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
12927 Name of the file where @command{rsync} writes its log file.
12929 @item @code{use-chroot?} (default: @var{#t})
12930 Whether to use chroot for @command{rsync} shared directory.
12932 @item @code{share-path} (default: @file{/srv/rsync})
12933 Location of the @command{rsync} shared directory.
12935 @item @code{share-comment} (default: @code{"Rsync share"})
12936 Comment of the @command{rsync} shared directory.
12938 @item @code{read-only?} (default: @var{#f})
12939 Read-write permissions to shared directory.
12941 @item @code{timeout} (default: @code{300})
12942 I/O timeout in seconds.
12944 @item @code{user} (default: @var{"root"})
12945 Owner of the @code{rsync} process.
12947 @item @code{group} (default: @var{"root"})
12948 Group of the @code{rsync} process.
12950 @item @code{uid} (default: @var{"rsyncd"})
12951 User name or user ID that file transfers to and from that module should take
12952 place as when the daemon was run as @code{root}.
12954 @item @code{gid} (default: @var{"rsyncd"})
12955 Group name or group ID that will be used when accessing the module.
12960 Furthermore, @code{(gnu services ssh)} provides the following services.
12964 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
12965 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
12966 [#:allow-empty-passwords? #f] [#:root-login? #f] @
12967 [#:syslog-output? #t] [#:x11-forwarding? #t] @
12968 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
12969 [#:public-key-authentication? #t] [#:initialize? #t]
12970 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
12971 @var{host-key} must designate a file containing the host key, and readable
12974 When @var{daemonic?} is true, @command{lshd} will detach from the
12975 controlling terminal and log its output to syslogd, unless one sets
12976 @var{syslog-output?} to false. Obviously, it also makes lsh-service
12977 depend on existence of syslogd service. When @var{pid-file?} is true,
12978 @command{lshd} writes its PID to the file called @var{pid-file}.
12980 When @var{initialize?} is true, automatically create the seed and host key
12981 upon service activation if they do not exist yet. This may take long and
12982 require interaction.
12984 When @var{initialize?} is false, it is up to the user to initialize the
12985 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
12986 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
12987 basics,,, lsh, LSH Manual}).
12989 When @var{interfaces} is empty, lshd listens for connections on all the
12990 network interfaces; otherwise, @var{interfaces} must be a list of host names
12993 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
12994 passwords, and @var{root-login?} specifies whether to accept log-ins as
12997 The other options should be self-descriptive.
13002 @deffn {Scheme Variable} openssh-service-type
13003 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
13004 shell daemon, @command{sshd}. Its value must be an
13005 @code{openssh-configuration} record as in this example:
13008 (service openssh-service-type
13009 (openssh-configuration
13010 (x11-forwarding? #t)
13011 (permit-root-login 'without-password)
13013 `(("alice" ,(local-file "alice.pub"))
13014 ("bob" ,(local-file "bob.pub"))))))
13017 See below for details about @code{openssh-configuration}.
13019 This service can be extended with extra authorized keys, as in this
13023 (service-extension openssh-service-type
13024 (const `(("charlie"
13025 ,(local-file "charlie.pub")))))
13029 @deftp {Data Type} openssh-configuration
13030 This is the configuration record for OpenSSH's @command{sshd}.
13033 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
13034 Name of the file where @command{sshd} writes its PID.
13036 @item @code{port-number} (default: @code{22})
13037 TCP port on which @command{sshd} listens for incoming connections.
13039 @item @code{permit-root-login} (default: @code{#f})
13040 This field determines whether and when to allow logins as root. If
13041 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
13042 If it's the symbol @code{'without-password}, then root logins are
13043 permitted but not with password-based authentication.
13045 @item @code{allow-empty-passwords?} (default: @code{#f})
13046 When true, users with empty passwords may log in. When false, they may
13049 @item @code{password-authentication?} (default: @code{#t})
13050 When true, users may log in with their password. When false, they have
13051 other authentication methods.
13053 @item @code{public-key-authentication?} (default: @code{#t})
13054 When true, users may log in using public key authentication. When
13055 false, users have to use other authentication method.
13057 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
13058 This is used only by protocol version 2.
13060 @item @code{x11-forwarding?} (default: @code{#f})
13061 When true, forwarding of X11 graphical client connections is
13062 enabled---in other words, @command{ssh} options @option{-X} and
13063 @option{-Y} will work.
13065 @item @code{allow-agent-forwarding?} (default: @code{#t})
13066 Whether to allow agent forwarding.
13068 @item @code{allow-tcp-forwarding?} (default: @code{#t})
13069 Whether to allow TCP forwarding.
13071 @item @code{gateway-ports?} (default: @code{#f})
13072 Whether to allow gateway ports.
13074 @item @code{challenge-response-authentication?} (default: @code{#f})
13075 Specifies whether challenge response authentication is allowed (e.g.@: via
13078 @item @code{use-pam?} (default: @code{#t})
13079 Enables the Pluggable Authentication Module interface. If set to
13080 @code{#t}, this will enable PAM authentication using
13081 @code{challenge-response-authentication?} and
13082 @code{password-authentication?}, in addition to PAM account and session
13083 module processing for all authentication types.
13085 Because PAM challenge response authentication usually serves an
13086 equivalent role to password authentication, you should disable either
13087 @code{challenge-response-authentication?} or
13088 @code{password-authentication?}.
13090 @item @code{print-last-log?} (default: @code{#t})
13091 Specifies whether @command{sshd} should print the date and time of the
13092 last user login when a user logs in interactively.
13094 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
13095 Configures external subsystems (e.g.@: file transfer daemon).
13097 This is a list of two-element lists, each of which containing the
13098 subsystem name and a command (with optional arguments) to execute upon
13101 The command @command{internal-sftp} implements an in-process SFTP
13102 server. Alternately, one can specify the @command{sftp-server} command:
13104 (service openssh-service-type
13105 (openssh-configuration
13107 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
13110 @item @code{accepted-environment} (default: @code{'()})
13111 List of strings describing which environment variables may be exported.
13113 Each string gets on its own line. See the @code{AcceptEnv} option in
13114 @code{man sshd_config}.
13116 This example allows ssh-clients to export the @code{COLORTERM} variable.
13117 It is set by terminal emulators, which support colors. You can use it in
13118 your shell's ressource file to enable colors for the prompt and commands
13119 if this variable is set.
13122 (service openssh-service-type
13123 (openssh-configuration
13124 (accepted-environment '("COLORTERM"))))
13127 @item @code{authorized-keys} (default: @code{'()})
13128 @cindex authorized keys, SSH
13129 @cindex SSH authorized keys
13130 This is the list of authorized keys. Each element of the list is a user
13131 name followed by one or more file-like objects that represent SSH public
13135 (openssh-configuration
13137 `(("rekado" ,(local-file "rekado.pub"))
13138 ("chris" ,(local-file "chris.pub"))
13139 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
13143 registers the specified public keys for user accounts @code{rekado},
13144 @code{chris}, and @code{root}.
13146 Additional authorized keys can be specified @i{via}
13147 @code{service-extension}.
13149 Note that this does @emph{not} interfere with the use of
13150 @file{~/.ssh/authorized_keys}.
13152 @item @code{log-level} (default: @code{'info})
13153 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
13154 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
13155 page for @file{sshd_config} for the full list of level names.
13157 @item @code{extra-content} (default: @code{""})
13158 This field can be used to append arbitrary text to the configuration file. It
13159 is especially useful for elaborate configurations that cannot be expressed
13160 otherwise. This configuration, for example, would generally disable root
13161 logins, but permit them from one specific IP address:
13164 (openssh-configuration
13166 Match Address 192.168.0.1
13167 PermitRootLogin yes"))
13173 @deffn {Scheme Procedure} dropbear-service [@var{config}]
13174 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
13175 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
13178 For example, to specify a Dropbear service listening on port 1234, add
13179 this call to the operating system's @code{services} field:
13182 (dropbear-service (dropbear-configuration
13183 (port-number 1234)))
13187 @deftp {Data Type} dropbear-configuration
13188 This data type represents the configuration of a Dropbear SSH daemon.
13191 @item @code{dropbear} (default: @var{dropbear})
13192 The Dropbear package to use.
13194 @item @code{port-number} (default: 22)
13195 The TCP port where the daemon waits for incoming connections.
13197 @item @code{syslog-output?} (default: @code{#t})
13198 Whether to enable syslog output.
13200 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
13201 File name of the daemon's PID file.
13203 @item @code{root-login?} (default: @code{#f})
13204 Whether to allow @code{root} logins.
13206 @item @code{allow-empty-passwords?} (default: @code{#f})
13207 Whether to allow empty passwords.
13209 @item @code{password-authentication?} (default: @code{#t})
13210 Whether to enable password-based authentication.
13214 @defvr {Scheme Variable} %facebook-host-aliases
13215 This variable contains a string for use in @file{/etc/hosts}
13216 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
13217 line contains a entry that maps a known server name of the Facebook
13218 on-line service---e.g., @code{www.facebook.com}---to the local
13219 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
13221 This variable is typically used in the @code{hosts-file} field of an
13222 @code{operating-system} declaration (@pxref{operating-system Reference,
13223 @file{/etc/hosts}}):
13226 (use-modules (gnu) (guix))
13229 (host-name "mymachine")
13232 ;; Create a /etc/hosts file with aliases for "localhost"
13233 ;; and "mymachine", as well as for Facebook servers.
13234 (plain-file "hosts"
13235 (string-append (local-host-aliases host-name)
13236 %facebook-host-aliases))))
13239 This mechanism can prevent programs running locally, such as Web
13240 browsers, from accessing Facebook.
13243 The @code{(gnu services avahi)} provides the following definition.
13245 @defvr {Scheme Variable} avahi-service-type
13246 This is the service that runs @command{avahi-daemon}, a system-wide
13247 mDNS/DNS-SD responder that allows for service discovery and
13248 ``zero-configuration'' host name lookups (see @uref{http://avahi.org/}).
13249 Its value must be a @code{zero-configuration} record---see below.
13251 This service extends the name service cache daemon (nscd) so that it can
13252 resolve @code{.local} host names using
13253 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
13254 Service Switch}, for information on host name resolution.
13256 Additionally, add the @var{avahi} package to the system profile so that
13257 commands such as @command{avahi-browse} are directly usable.
13260 @deftp {Data Type} avahi-configuration
13261 Data type representation the configuration for Avahi.
13265 @item @code{host-name} (default: @code{#f})
13266 If different from @code{#f}, use that as the host name to
13267 publish for this machine; otherwise, use the machine's actual host name.
13269 @item @code{publish?} (default: @code{#t})
13270 When true, allow host names and services to be published (broadcast) over the
13273 @item @code{publish-workstation?} (default: @code{#t})
13274 When true, @command{avahi-daemon} publishes the machine's host name and IP
13275 address via mDNS on the local network. To view the host names published on
13276 your local network, you can run:
13279 avahi-browse _workstation._tcp
13282 @item @code{wide-area?} (default: @code{#f})
13283 When true, DNS-SD over unicast DNS is enabled.
13285 @item @code{ipv4?} (default: @code{#t})
13286 @itemx @code{ipv6?} (default: @code{#t})
13287 These fields determine whether to use IPv4/IPv6 sockets.
13289 @item @code{domains-to-browse} (default: @code{'()})
13290 This is a list of domains to browse.
13294 @deffn {Scheme Variable} openvswitch-service-type
13295 This is the type of the @uref{http://www.openvswitch.org, Open vSwitch}
13296 service, whose value should be an @code{openvswitch-configuration}
13300 @deftp {Data Type} openvswitch-configuration
13301 Data type representing the configuration of Open vSwitch, a multilayer
13302 virtual switch which is designed to enable massive network automation
13303 through programmatic extension.
13306 @item @code{package} (default: @var{openvswitch})
13307 Package object of the Open vSwitch.
13313 @subsection X Window
13316 @cindex X Window System
13317 @cindex login manager
13318 Support for the X Window graphical display system---specifically
13319 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
13320 there is no @code{xorg-service} procedure. Instead, the X server is
13321 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
13324 @cindex GNOME, login manager
13325 GDM of course allows users to log in into window managers and desktop
13326 environments other than GNOME; for those using GNOME, GDM is required for
13327 features such as automatic screen locking.
13329 @cindex window manager
13330 To use X11, you must install at least one @dfn{window manager}---for
13331 example the @code{windowmaker} or @code{openbox} packages---preferably
13332 by adding it to the @code{packages} field of your operating system
13333 definition (@pxref{operating-system Reference, system-wide packages}).
13335 @defvr {Scheme Variable} gdm-service-type
13336 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
13337 Desktop Manager} (GDM), a program that manages graphical display servers and
13338 handles graphical user logins. Its value must be a @code{gdm-configuration}
13341 @cindex session types (X11)
13342 @cindex X11 session types
13343 GDM looks for @dfn{session types} described by the @file{.desktop} files in
13344 @file{/run/current-system/profile/share/xsessions} and allows users to choose
13345 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
13346 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
13347 set of packages automatically makes them available at the log-in screen.
13349 In addition, @file{~/.xsession} files are honored. When available,
13350 @file{~/.xsession} must be an executable that starts a window manager
13351 and/or other X clients.
13354 @deftp {Data Type} gdm-configuration
13356 @item @code{auto-login?} (default: @code{#f})
13357 @itemx @code{default-user} (default: @code{#f})
13358 When @code{auto-login?} is false, GDM presents a log-in screen.
13360 When @code{auto-login?} is true, GDM logs in directly as
13361 @code{default-user}.
13363 @item @code{gnome-shell-assets} (default: ...)
13364 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
13366 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
13367 Configuration of the Xorg graphical server.
13369 @item @code{xsession} (default: @code{(xinitrc)})
13370 Script to run before starting a X session.
13372 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
13373 File name of the @code{dbus-daemon} executable.
13375 @item @code{gdm} (default: @code{gdm})
13376 The GDM package to use.
13380 @defvr {Scheme Variable} slim-service-type
13381 This is the type for the SLiM graphical login manager for X11.
13383 Like GDM, SLiM looks for session types described by @file{.desktop} files and
13384 allows users to choose a session from the log-in screen using @kbd{F1}. It
13385 also honors @file{~/.xsession} files.
13388 @deftp {Data Type} slim-configuration
13389 Data type representing the configuration of @code{slim-service-type}.
13392 @item @code{allow-empty-passwords?} (default: @code{#t})
13393 Whether to allow logins with empty passwords.
13395 @item @code{auto-login?} (default: @code{#f})
13396 @itemx @code{default-user} (default: @code{""})
13397 When @code{auto-login?} is false, SLiM presents a log-in screen.
13399 When @code{auto-login?} is true, SLiM logs in directly as
13400 @code{default-user}.
13402 @item @code{theme} (default: @code{%default-slim-theme})
13403 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
13404 The graphical theme to use and its name.
13406 @item @code{auto-login-session} (default: @code{#f})
13407 If true, this must be the name of the executable to start as the default
13408 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
13410 If false, a session described by one of the available @file{.desktop}
13411 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
13415 You must install at least one window manager in the system profile or in
13416 your user profile. Failing to do that, if @code{auto-login-session} is
13417 false, you will be unable to log in.
13420 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13421 Configuration of the Xorg graphical server.
13423 @item @code{xauth} (default: @code{xauth})
13424 The XAuth package to use.
13426 @item @code{shepherd} (default: @code{shepherd})
13427 The Shepherd package used when invoking @command{halt} and
13430 @item @code{sessreg} (default: @code{sessreg})
13431 The sessreg package used in order to register the session.
13433 @item @code{slim} (default: @code{slim})
13434 The SLiM package to use.
13438 @defvr {Scheme Variable} %default-theme
13439 @defvrx {Scheme Variable} %default-theme-name
13440 The default SLiM theme and its name.
13444 @deftp {Data Type} sddm-configuration
13445 This is the data type representing the sddm service configuration.
13448 @item @code{display-server} (default: "x11")
13449 Select display server to use for the greeter. Valid values are "x11"
13452 @item @code{numlock} (default: "on")
13453 Valid values are "on", "off" or "none".
13455 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
13456 Command to run when halting.
13458 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
13459 Command to run when rebooting.
13461 @item @code{theme} (default "maldives")
13462 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
13464 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
13465 Directory to look for themes.
13467 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
13468 Directory to look for faces.
13470 @item @code{default-path} (default "/run/current-system/profile/bin")
13471 Default PATH to use.
13473 @item @code{minimum-uid} (default 1000)
13474 Minimum UID to display in SDDM.
13476 @item @code{maximum-uid} (default 2000)
13477 Maximum UID to display in SDDM
13479 @item @code{remember-last-user?} (default #t)
13480 Remember last user.
13482 @item @code{remember-last-session?} (default #t)
13483 Remember last session.
13485 @item @code{hide-users} (default "")
13486 Usernames to hide from SDDM greeter.
13488 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
13489 Users with shells listed will be hidden from the SDDM greeter.
13491 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
13492 Script to run before starting a wayland session.
13494 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
13495 Directory to look for desktop files starting wayland sessions.
13497 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13498 Configuration of the Xorg graphical server.
13500 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
13503 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
13506 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
13507 Script to run after starting xorg-server.
13509 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
13510 Script to run before stopping xorg-server.
13512 @item @code{xsession-command} (default: @code{xinitrc})
13513 Script to run before starting a X session.
13515 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
13516 Directory to look for desktop files starting X sessions.
13518 @item @code{minimum-vt} (default: 7)
13521 @item @code{auto-login-user} (default "")
13522 User to use for auto-login.
13524 @item @code{auto-login-session} (default "")
13525 Desktop file to use for auto-login.
13527 @item @code{relogin?} (default #f)
13528 Relogin after logout.
13533 @cindex login manager
13535 @deffn {Scheme Procedure} sddm-service config
13536 Return a service that spawns the SDDM graphical login manager for config of
13537 type @code{<sddm-configuration>}.
13540 (sddm-service (sddm-configuration
13541 (auto-login-user "Alice")
13542 (auto-login-session "xfce.desktop")))
13546 @cindex Xorg, configuration
13547 @deftp {Data Type} xorg-configuration
13548 This data type represents the configuration of the Xorg graphical display
13549 server. Note that there is not Xorg service; instead, the X server is started
13550 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
13551 of these display managers aggregates an @code{xorg-configuration} record.
13554 @item @code{modules} (default: @code{%default-xorg-modules})
13555 This is a list of @dfn{module packages} loaded by the Xorg
13556 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
13558 @item @code{fonts} (default: @code{%default-xorg-fonts})
13559 This is a list of font directories to add to the server's @dfn{font path}.
13561 @item @code{drivers} (default: @code{'()})
13562 This must be either the empty list, in which case Xorg chooses a graphics
13563 driver automatically, or a list of driver names that will be tried in this
13564 order---e.g., @code{("modesetting" "vesa")}.
13566 @item @code{resolutions} (default: @code{'()})
13567 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
13568 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
13571 @cindex keyboard layout, for Xorg
13572 @cindex keymap, for Xorg
13573 @item @code{keyboard-layout} (default: @code{#f})
13574 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
13575 English (``qwerty'') for a 105-key PC keyboard.
13577 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
13578 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
13579 information on how to specify the keyboard layout.
13581 @item @code{extra-config} (default: @code{'()})
13582 This is a list of strings or objects appended to the configuration file. It
13583 is used to pass extra text to be added verbatim to the configuration file.
13585 @item @code{server} (default: @code{xorg-server})
13586 This is the package providing the Xorg server.
13588 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
13589 This is the list of command-line arguments to pass to the X server. The
13590 default is @code{-nolisten tcp}.
13594 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
13595 [@var{login-manager-service-type}]
13596 Tell the log-in manager (of type @var{login-manager-service-type}) to use
13597 @var{config}, an <xorg-configuration> record.
13599 Since the Xorg configuration is embedded in the log-in manager's
13600 configuration---e.g., @code{gdm-configuration}---this procedure provides a
13601 shorthand to set the Xorg configuration.
13604 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
13605 Return a @code{startx} script in which the modules, fonts, etc. specified
13606 in @var{config}, are available. The result should be used in place of
13609 Usually the X server is started by a login manager.
13613 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
13614 Add @var{package}, a package for a screen locker or screen saver whose
13615 command is @var{program}, to the set of setuid programs and add a PAM entry
13616 for it. For example:
13619 (screen-locker-service xlockmore "xlock")
13622 makes the good ol' XlockMore usable.
13626 @node Printing Services
13627 @subsection Printing Services
13629 @cindex printer support with CUPS
13630 The @code{(gnu services cups)} module provides a Guix service definition
13631 for the CUPS printing service. To add printer support to a Guix
13632 system, add a @code{cups-service} to the operating system definition:
13634 @deffn {Scheme Variable} cups-service-type
13635 The service type for the CUPS print server. Its value should be a valid
13636 CUPS configuration (see below). To use the default settings, simply
13639 (service cups-service-type)
13643 The CUPS configuration controls the basic things about your CUPS
13644 installation: what interfaces it listens on, what to do if a print job
13645 fails, how much logging to do, and so on. To actually add a printer,
13646 you have to visit the @url{http://localhost:631} URL, or use a tool such
13647 as GNOME's printer configuration services. By default, configuring a
13648 CUPS service will generate a self-signed certificate if needed, for
13649 secure connections to the print server.
13651 Suppose you want to enable the Web interface of CUPS and also add
13652 support for Epson printers @i{via} the @code{escpr} package and for HP
13653 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
13654 like this (you need to use the @code{(gnu packages cups)} module):
13657 (service cups-service-type
13658 (cups-configuration
13659 (web-interface? #t)
13661 (list cups-filters escpr hplip-minimal))))
13664 Note: If you wish to use the Qt5 based GUI which comes with the hplip
13665 package then it is suggested that you install the @code{hplip} package,
13666 either in your OS configuration file or as your user.
13668 The available configuration parameters follow. Each parameter
13669 definition is preceded by its type; for example, @samp{string-list foo}
13670 indicates that the @code{foo} parameter should be specified as a list of
13671 strings. There is also a way to specify the configuration as a string,
13672 if you have an old @code{cupsd.conf} file that you want to port over
13673 from some other system; see the end for more details.
13675 @c The following documentation was initially generated by
13676 @c (generate-documentation) in (gnu services cups). Manually maintained
13677 @c documentation is better, so we shouldn't hesitate to edit below as
13678 @c needed. However if the change you want to make to this documentation
13679 @c can be done in an automated way, it's probably easier to change
13680 @c (generate-documentation) than to make it below and have to deal with
13681 @c the churn as CUPS updates.
13684 Available @code{cups-configuration} fields are:
13686 @deftypevr {@code{cups-configuration} parameter} package cups
13690 @deftypevr {@code{cups-configuration} parameter} package-list extensions
13691 Drivers and other extensions to the CUPS package.
13694 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
13695 Configuration of where to write logs, what directories to use for print
13696 spools, and related privileged configuration parameters.
13698 Available @code{files-configuration} fields are:
13700 @deftypevr {@code{files-configuration} parameter} log-location access-log
13701 Defines the access log filename. Specifying a blank filename disables
13702 access log generation. The value @code{stderr} causes log entries to be
13703 sent to the standard error file when the scheduler is running in the
13704 foreground, or to the system log daemon when run in the background. The
13705 value @code{syslog} causes log entries to be sent to the system log
13706 daemon. The server name may be included in filenames using the string
13707 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
13709 Defaults to @samp{"/var/log/cups/access_log"}.
13712 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
13713 Where CUPS should cache data.
13715 Defaults to @samp{"/var/cache/cups"}.
13718 @deftypevr {@code{files-configuration} parameter} string config-file-perm
13719 Specifies the permissions for all configuration files that the scheduler
13722 Note that the permissions for the printers.conf file are currently
13723 masked to only allow access from the scheduler user (typically root).
13724 This is done because printer device URIs sometimes contain sensitive
13725 authentication information that should not be generally known on the
13726 system. There is no way to disable this security feature.
13728 Defaults to @samp{"0640"}.
13731 @deftypevr {@code{files-configuration} parameter} log-location error-log
13732 Defines the error log filename. Specifying a blank filename disables
13733 access log generation. The value @code{stderr} causes log entries to be
13734 sent to the standard error file when the scheduler is running in the
13735 foreground, or to the system log daemon when run in the background. The
13736 value @code{syslog} causes log entries to be sent to the system log
13737 daemon. The server name may be included in filenames using the string
13738 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
13740 Defaults to @samp{"/var/log/cups/error_log"}.
13743 @deftypevr {@code{files-configuration} parameter} string fatal-errors
13744 Specifies which errors are fatal, causing the scheduler to exit. The
13749 No errors are fatal.
13752 All of the errors below are fatal.
13755 Browsing initialization errors are fatal, for example failed connections
13756 to the DNS-SD daemon.
13759 Configuration file syntax errors are fatal.
13762 Listen or Port errors are fatal, except for IPv6 failures on the
13763 loopback or @code{any} addresses.
13766 Log file creation or write errors are fatal.
13769 Bad startup file permissions are fatal, for example shared TLS
13770 certificate and key files with world-read permissions.
13773 Defaults to @samp{"all -browse"}.
13776 @deftypevr {@code{files-configuration} parameter} boolean file-device?
13777 Specifies whether the file pseudo-device can be used for new printer
13778 queues. The URI @uref{file:///dev/null} is always allowed.
13780 Defaults to @samp{#f}.
13783 @deftypevr {@code{files-configuration} parameter} string group
13784 Specifies the group name or ID that will be used when executing external
13787 Defaults to @samp{"lp"}.
13790 @deftypevr {@code{files-configuration} parameter} string log-file-perm
13791 Specifies the permissions for all log files that the scheduler writes.
13793 Defaults to @samp{"0644"}.
13796 @deftypevr {@code{files-configuration} parameter} log-location page-log
13797 Defines the page log filename. Specifying a blank filename disables
13798 access log generation. The value @code{stderr} causes log entries to be
13799 sent to the standard error file when the scheduler is running in the
13800 foreground, or to the system log daemon when run in the background. The
13801 value @code{syslog} causes log entries to be sent to the system log
13802 daemon. The server name may be included in filenames using the string
13803 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
13805 Defaults to @samp{"/var/log/cups/page_log"}.
13808 @deftypevr {@code{files-configuration} parameter} string remote-root
13809 Specifies the username that is associated with unauthenticated accesses
13810 by clients claiming to be the root user. The default is @code{remroot}.
13812 Defaults to @samp{"remroot"}.
13815 @deftypevr {@code{files-configuration} parameter} file-name request-root
13816 Specifies the directory that contains print jobs and other HTTP request
13819 Defaults to @samp{"/var/spool/cups"}.
13822 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
13823 Specifies the level of security sandboxing that is applied to print
13824 filters, backends, and other child processes of the scheduler; either
13825 @code{relaxed} or @code{strict}. This directive is currently only
13826 used/supported on macOS.
13828 Defaults to @samp{strict}.
13831 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
13832 Specifies the location of TLS certificates and private keys. CUPS will
13833 look for public and private keys in this directory: a @code{.crt} files
13834 for PEM-encoded certificates and corresponding @code{.key} files for
13835 PEM-encoded private keys.
13837 Defaults to @samp{"/etc/cups/ssl"}.
13840 @deftypevr {@code{files-configuration} parameter} file-name server-root
13841 Specifies the directory containing the server configuration files.
13843 Defaults to @samp{"/etc/cups"}.
13846 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
13847 Specifies whether the scheduler calls fsync(2) after writing
13848 configuration or state files.
13850 Defaults to @samp{#f}.
13853 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
13854 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
13857 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
13858 Specifies the directory where temporary files are stored.
13860 Defaults to @samp{"/var/spool/cups/tmp"}.
13863 @deftypevr {@code{files-configuration} parameter} string user
13864 Specifies the user name or ID that is used when running external
13867 Defaults to @samp{"lp"}.
13871 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
13872 Specifies the logging level for the AccessLog file. The @code{config}
13873 level logs when printers and classes are added, deleted, or modified and
13874 when configuration files are accessed or updated. The @code{actions}
13875 level logs when print jobs are submitted, held, released, modified, or
13876 canceled, and any of the conditions for @code{config}. The @code{all}
13877 level logs all requests.
13879 Defaults to @samp{actions}.
13882 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
13883 Specifies whether to purge job history data automatically when it is no
13884 longer required for quotas.
13886 Defaults to @samp{#f}.
13889 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
13890 Specifies which protocols to use for local printer sharing.
13892 Defaults to @samp{dnssd}.
13895 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
13896 Specifies whether the CUPS web interface is advertised.
13898 Defaults to @samp{#f}.
13901 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
13902 Specifies whether shared printers are advertised.
13904 Defaults to @samp{#f}.
13907 @deftypevr {@code{cups-configuration} parameter} string classification
13908 Specifies the security classification of the server. Any valid banner
13909 name can be used, including "classified", "confidential", "secret",
13910 "topsecret", and "unclassified", or the banner can be omitted to disable
13911 secure printing functions.
13913 Defaults to @samp{""}.
13916 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
13917 Specifies whether users may override the classification (cover page) of
13918 individual print jobs using the @code{job-sheets} option.
13920 Defaults to @samp{#f}.
13923 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
13924 Specifies the default type of authentication to use.
13926 Defaults to @samp{Basic}.
13929 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
13930 Specifies whether encryption will be used for authenticated requests.
13932 Defaults to @samp{Required}.
13935 @deftypevr {@code{cups-configuration} parameter} string default-language
13936 Specifies the default language to use for text and web content.
13938 Defaults to @samp{"en"}.
13941 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
13942 Specifies the default paper size for new print queues. @samp{"Auto"}
13943 uses a locale-specific default, while @samp{"None"} specifies there is
13944 no default paper size. Specific size names are typically
13945 @samp{"Letter"} or @samp{"A4"}.
13947 Defaults to @samp{"Auto"}.
13950 @deftypevr {@code{cups-configuration} parameter} string default-policy
13951 Specifies the default access policy to use.
13953 Defaults to @samp{"default"}.
13956 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
13957 Specifies whether local printers are shared by default.
13959 Defaults to @samp{#t}.
13962 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
13963 Specifies the delay for updating of configuration and state files, in
13964 seconds. A value of 0 causes the update to happen as soon as possible,
13965 typically within a few milliseconds.
13967 Defaults to @samp{30}.
13970 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
13971 Specifies what to do when an error occurs. Possible values are
13972 @code{abort-job}, which will discard the failed print job;
13973 @code{retry-job}, which will retry the job at a later time;
13974 @code{retry-this-job}, which retries the failed job immediately; and
13975 @code{stop-printer}, which stops the printer.
13977 Defaults to @samp{stop-printer}.
13980 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
13981 Specifies the maximum cost of filters that are run concurrently, which
13982 can be used to minimize disk, memory, and CPU resource problems. A
13983 limit of 0 disables filter limiting. An average print to a
13984 non-PostScript printer needs a filter limit of about 200. A PostScript
13985 printer needs about half that (100). Setting the limit below these
13986 thresholds will effectively limit the scheduler to printing a single job
13989 Defaults to @samp{0}.
13992 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
13993 Specifies the scheduling priority of filters that are run to print a
13994 job. The nice value ranges from 0, the highest priority, to 19, the
13997 Defaults to @samp{0}.
14000 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
14001 Specifies whether to do reverse lookups on connecting clients. The
14002 @code{double} setting causes @code{cupsd} to verify that the hostname
14003 resolved from the address matches one of the addresses returned for that
14004 hostname. Double lookups also prevent clients with unregistered
14005 addresses from connecting to your server. Only set this option to
14006 @code{#t} or @code{double} if absolutely required.
14008 Defaults to @samp{#f}.
14011 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
14012 Specifies the number of seconds to wait before killing the filters and
14013 backend associated with a canceled or held job.
14015 Defaults to @samp{30}.
14018 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
14019 Specifies the interval between retries of jobs in seconds. This is
14020 typically used for fax queues but can also be used with normal print
14021 queues whose error policy is @code{retry-job} or
14022 @code{retry-current-job}.
14024 Defaults to @samp{30}.
14027 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
14028 Specifies the number of retries that are done for jobs. This is
14029 typically used for fax queues but can also be used with normal print
14030 queues whose error policy is @code{retry-job} or
14031 @code{retry-current-job}.
14033 Defaults to @samp{5}.
14036 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
14037 Specifies whether to support HTTP keep-alive connections.
14039 Defaults to @samp{#t}.
14042 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
14043 Specifies how long an idle client connection remains open, in seconds.
14045 Defaults to @samp{30}.
14048 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
14049 Specifies the maximum size of print files, IPP requests, and HTML form
14050 data. A limit of 0 disables the limit check.
14052 Defaults to @samp{0}.
14055 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
14056 Listens on the specified interfaces for connections. Valid values are
14057 of the form @var{address}:@var{port}, where @var{address} is either an
14058 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
14059 indicate all addresses. Values can also be file names of local UNIX
14060 domain sockets. The Listen directive is similar to the Port directive
14061 but allows you to restrict access to specific interfaces or networks.
14064 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
14065 Specifies the number of pending connections that will be allowed. This
14066 normally only affects very busy servers that have reached the MaxClients
14067 limit, but can also be triggered by large numbers of simultaneous
14068 connections. When the limit is reached, the operating system will
14069 refuse additional connections until the scheduler can accept the pending
14072 Defaults to @samp{128}.
14075 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
14076 Specifies a set of additional access controls.
14078 Available @code{location-access-controls} fields are:
14080 @deftypevr {@code{location-access-controls} parameter} file-name path
14081 Specifies the URI path to which the access control applies.
14084 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
14085 Access controls for all access to this path, in the same format as the
14086 @code{access-controls} of @code{operation-access-control}.
14088 Defaults to @samp{()}.
14091 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
14092 Access controls for method-specific access to this path.
14094 Defaults to @samp{()}.
14096 Available @code{method-access-controls} fields are:
14098 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
14099 If @code{#t}, apply access controls to all methods except the listed
14100 methods. Otherwise apply to only the listed methods.
14102 Defaults to @samp{#f}.
14105 @deftypevr {@code{method-access-controls} parameter} method-list methods
14106 Methods to which this access control applies.
14108 Defaults to @samp{()}.
14111 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
14112 Access control directives, as a list of strings. Each string should be
14113 one directive, such as "Order allow,deny".
14115 Defaults to @samp{()}.
14120 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
14121 Specifies the number of debugging messages that are retained for logging
14122 if an error occurs in a print job. Debug messages are logged regardless
14123 of the LogLevel setting.
14125 Defaults to @samp{100}.
14128 @deftypevr {@code{cups-configuration} parameter} log-level log-level
14129 Specifies the level of logging for the ErrorLog file. The value
14130 @code{none} stops all logging while @code{debug2} logs everything.
14132 Defaults to @samp{info}.
14135 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
14136 Specifies the format of the date and time in the log files. The value
14137 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
14139 Defaults to @samp{standard}.
14142 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
14143 Specifies the maximum number of simultaneous clients that are allowed by
14146 Defaults to @samp{100}.
14149 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
14150 Specifies the maximum number of simultaneous clients that are allowed
14151 from a single address.
14153 Defaults to @samp{100}.
14156 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
14157 Specifies the maximum number of copies that a user can print of each
14160 Defaults to @samp{9999}.
14163 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
14164 Specifies the maximum time a job may remain in the @code{indefinite}
14165 hold state before it is canceled. A value of 0 disables cancellation of
14168 Defaults to @samp{0}.
14171 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
14172 Specifies the maximum number of simultaneous jobs that are allowed. Set
14173 to 0 to allow an unlimited number of jobs.
14175 Defaults to @samp{500}.
14178 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
14179 Specifies the maximum number of simultaneous jobs that are allowed per
14180 printer. A value of 0 allows up to MaxJobs jobs per printer.
14182 Defaults to @samp{0}.
14185 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
14186 Specifies the maximum number of simultaneous jobs that are allowed per
14187 user. A value of 0 allows up to MaxJobs jobs per user.
14189 Defaults to @samp{0}.
14192 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
14193 Specifies the maximum time a job may take to print before it is
14194 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
14196 Defaults to @samp{10800}.
14199 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
14200 Specifies the maximum size of the log files before they are rotated, in
14201 bytes. The value 0 disables log rotation.
14203 Defaults to @samp{1048576}.
14206 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
14207 Specifies the maximum amount of time to allow between files in a
14208 multiple file print job, in seconds.
14210 Defaults to @samp{300}.
14213 @deftypevr {@code{cups-configuration} parameter} string page-log-format
14214 Specifies the format of PageLog lines. Sequences beginning with percent
14215 (@samp{%}) characters are replaced with the corresponding information,
14216 while all other characters are copied literally. The following percent
14217 sequences are recognized:
14221 insert a single percent character
14224 insert the value of the specified IPP attribute
14227 insert the number of copies for the current page
14230 insert the current page number
14233 insert the current date and time in common log format
14239 insert the printer name
14242 insert the username
14245 A value of the empty string disables page logging. The string @code{%p
14246 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
14247 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
14250 Defaults to @samp{""}.
14253 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
14254 Passes the specified environment variable(s) to child processes; a list
14257 Defaults to @samp{()}.
14260 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
14261 Specifies named access control policies.
14263 Available @code{policy-configuration} fields are:
14265 @deftypevr {@code{policy-configuration} parameter} string name
14266 Name of the policy.
14269 @deftypevr {@code{policy-configuration} parameter} string job-private-access
14270 Specifies an access list for a job's private values. @code{@@ACL} maps
14271 to the printer's requesting-user-name-allowed or
14272 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14273 owner. @code{@@SYSTEM} maps to the groups listed for the
14274 @code{system-group} field of the @code{files-config} configuration,
14275 which is reified into the @code{cups-files.conf(5)} file. Other
14276 possible elements of the access list include specific user names, and
14277 @code{@@@var{group}} to indicate members of a specific group. The
14278 access list may also be simply @code{all} or @code{default}.
14280 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14283 @deftypevr {@code{policy-configuration} parameter} string job-private-values
14284 Specifies the list of job values to make private, or @code{all},
14285 @code{default}, or @code{none}.
14287 Defaults to @samp{"job-name job-originating-host-name
14288 job-originating-user-name phone"}.
14291 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
14292 Specifies an access list for a subscription's private values.
14293 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
14294 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14295 owner. @code{@@SYSTEM} maps to the groups listed for the
14296 @code{system-group} field of the @code{files-config} configuration,
14297 which is reified into the @code{cups-files.conf(5)} file. Other
14298 possible elements of the access list include specific user names, and
14299 @code{@@@var{group}} to indicate members of a specific group. The
14300 access list may also be simply @code{all} or @code{default}.
14302 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14305 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
14306 Specifies the list of job values to make private, or @code{all},
14307 @code{default}, or @code{none}.
14309 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
14310 notify-subscriber-user-name notify-user-data"}.
14313 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
14314 Access control by IPP operation.
14316 Defaults to @samp{()}.
14320 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
14321 Specifies whether job files (documents) are preserved after a job is
14322 printed. If a numeric value is specified, job files are preserved for
14323 the indicated number of seconds after printing. Otherwise a boolean
14324 value applies indefinitely.
14326 Defaults to @samp{86400}.
14329 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
14330 Specifies whether the job history is preserved after a job is printed.
14331 If a numeric value is specified, the job history is preserved for the
14332 indicated number of seconds after printing. If @code{#t}, the job
14333 history is preserved until the MaxJobs limit is reached.
14335 Defaults to @samp{#t}.
14338 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
14339 Specifies the amount of time to wait for job completion before
14340 restarting the scheduler.
14342 Defaults to @samp{30}.
14345 @deftypevr {@code{cups-configuration} parameter} string rip-cache
14346 Specifies the maximum amount of memory to use when converting documents
14347 into bitmaps for a printer.
14349 Defaults to @samp{"128m"}.
14352 @deftypevr {@code{cups-configuration} parameter} string server-admin
14353 Specifies the email address of the server administrator.
14355 Defaults to @samp{"root@@localhost.localdomain"}.
14358 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
14359 The ServerAlias directive is used for HTTP Host header validation when
14360 clients connect to the scheduler from external interfaces. Using the
14361 special name @code{*} can expose your system to known browser-based DNS
14362 rebinding attacks, even when accessing sites through a firewall. If the
14363 auto-discovery of alternate names does not work, we recommend listing
14364 each alternate name with a ServerAlias directive instead of using
14367 Defaults to @samp{*}.
14370 @deftypevr {@code{cups-configuration} parameter} string server-name
14371 Specifies the fully-qualified host name of the server.
14373 Defaults to @samp{"localhost"}.
14376 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
14377 Specifies what information is included in the Server header of HTTP
14378 responses. @code{None} disables the Server header. @code{ProductOnly}
14379 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
14380 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
14381 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
14382 the output of the @code{uname} command. @code{Full} reports @code{CUPS
14383 2.0.0 (@var{uname}) IPP/2.0}.
14385 Defaults to @samp{Minimal}.
14388 @deftypevr {@code{cups-configuration} parameter} string set-env
14389 Set the specified environment variable to be passed to child processes.
14391 Defaults to @samp{"variable value"}.
14394 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
14395 Listens on the specified interfaces for encrypted connections. Valid
14396 values are of the form @var{address}:@var{port}, where @var{address} is
14397 either an IPv6 address enclosed in brackets, an IPv4 address, or
14398 @code{*} to indicate all addresses.
14400 Defaults to @samp{()}.
14403 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
14404 Sets encryption options. By default, CUPS only supports encryption
14405 using TLS v1.0 or higher using known secure cipher suites. The
14406 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
14407 required for some older clients that do not implement newer ones. The
14408 @code{AllowSSL3} option enables SSL v3.0, which is required for some
14409 older clients that do not support TLS v1.0.
14411 Defaults to @samp{()}.
14414 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
14415 Specifies whether the scheduler requires clients to strictly adhere to
14416 the IPP specifications.
14418 Defaults to @samp{#f}.
14421 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
14422 Specifies the HTTP request timeout, in seconds.
14424 Defaults to @samp{300}.
14428 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
14429 Specifies whether the web interface is enabled.
14431 Defaults to @samp{#f}.
14434 At this point you're probably thinking ``oh dear, Guix manual, I like
14435 you but you can stop already with the configuration options''. Indeed.
14436 However, one more point: it could be that you have an existing
14437 @code{cupsd.conf} that you want to use. In that case, you can pass an
14438 @code{opaque-cups-configuration} as the configuration of a
14439 @code{cups-service-type}.
14441 Available @code{opaque-cups-configuration} fields are:
14443 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
14447 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
14448 The contents of the @code{cupsd.conf}, as a string.
14451 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
14452 The contents of the @code{cups-files.conf} file, as a string.
14455 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
14456 strings of the same name, you could instantiate a CUPS service like
14460 (service cups-service-type
14461 (opaque-cups-configuration
14462 (cupsd.conf cupsd.conf)
14463 (cups-files.conf cups-files.conf)))
14467 @node Desktop Services
14468 @subsection Desktop Services
14470 The @code{(gnu services desktop)} module provides services that are
14471 usually useful in the context of a ``desktop'' setup---that is, on a
14472 machine running a graphical display server, possibly with graphical user
14473 interfaces, etc. It also defines services that provide specific desktop
14474 environments like GNOME, Xfce or MATE.
14476 To simplify things, the module defines a variable containing the set of
14477 services that users typically expect on a machine with a graphical
14478 environment and networking:
14480 @defvr {Scheme Variable} %desktop-services
14481 This is a list of services that builds upon @var{%base-services} and
14482 adds or adjusts services for a typical ``desktop'' setup.
14484 In particular, it adds a graphical login manager (@pxref{X Window,
14485 @code{gdm-service-type}}), screen lockers, a network management tool
14486 (@pxref{Networking Services, @code{network-manager-service-type}}), energy and color
14487 management services, the @code{elogind} login and seat manager, the
14488 Polkit privilege service, the GeoClue location service, the
14489 AccountsService daemon that allows authorized users change system
14490 passwords, an NTP client (@pxref{Networking Services}), the Avahi
14491 daemon, and has the name service switch service configured to be able to
14492 use @code{nss-mdns} (@pxref{Name Service Switch, mDNS}).
14495 The @var{%desktop-services} variable can be used as the @code{services}
14496 field of an @code{operating-system} declaration (@pxref{operating-system
14497 Reference, @code{services}}).
14499 Additionally, the @code{gnome-desktop-service-type},
14500 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
14501 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
14502 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
14503 services like the backlight adjustment helpers and the power management
14504 utilities are added to the system, extending @code{polkit} and @code{dbus}
14505 appropriately, allowing GNOME to operate with elevated privileges on a
14506 limited number of special-purpose system interfaces. Additionally,
14507 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
14508 metapackage to the system profile. Likewise, adding the Xfce service
14509 not only adds the @code{xfce} metapackage to the system profile, but it
14510 also gives the Thunar file manager the ability to open a ``root-mode''
14511 file management window, if the user authenticates using the
14512 administrator's password via the standard polkit graphical interface.
14513 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
14514 appropriately, allowing MATE to operate with elevated privileges on a
14515 limited number of special-purpose system interfaces. Additionally,
14516 adding a service of type @code{mate-desktop-service-type} adds the MATE
14517 metapackage to the system profile. ``Adding Enlightenment'' means that
14518 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
14519 are set as setuid, allowing Enlightenment's screen locker and other
14520 functionality to work as expetected.
14522 The desktop environments in Guix use the Xorg display server by
14523 default. If you'd like to use the newer display server protocol
14524 called Wayland, you need to use the @code{sddm-service} instead of
14525 GDM as the graphical login manager. You should then
14526 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
14527 also try starting GNOME on Wayland manually from a TTY with the
14528 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
14529 gnome-session``. Currently only GNOME has support for Wayland.
14531 @defvr {Scheme Variable} gnome-desktop-service-type
14532 This is the type of the service that adds the @uref{https://www.gnome.org,
14533 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
14534 object (see below.)
14536 This service adds the @code{gnome} package to the system profile, and extends
14537 polkit with the actions from @code{gnome-settings-daemon}.
14540 @deftp {Data Type} gnome-desktop-configuration
14541 Configuration record for the GNOME desktop environment.
14544 @item @code{gnome} (default @code{gnome})
14545 The GNOME package to use.
14549 @defvr {Scheme Variable} xfce-desktop-service-type
14550 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
14551 desktop environment. Its value is an @code{xfce-desktop-configuration} object
14554 This service that adds the @code{xfce} package to the system profile, and
14555 extends polkit with the ability for @code{thunar} to manipulate the file
14556 system as root from within a user session, after the user has authenticated
14557 with the administrator's password.
14560 @deftp {Data Type} xfce-desktop-configuration
14561 Configuration record for the Xfce desktop environment.
14564 @item @code{xfce} (default @code{xfce})
14565 The Xfce package to use.
14569 @deffn {Scheme Variable} mate-desktop-service-type
14570 This is the type of the service that runs the @uref{https://mate-desktop.org/,
14571 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
14572 object (see below.)
14574 This service adds the @code{mate} package to the system
14575 profile, and extends polkit with the actions from
14576 @code{mate-settings-daemon}.
14579 @deftp {Data Type} mate-desktop-configuration
14580 Configuration record for the MATE desktop environment.
14583 @item @code{mate} (default @code{mate})
14584 The MATE package to use.
14588 @deffn {Scheme Variable} enlightenment-desktop-service-type
14589 Return a service that adds the @code{enlightenment} package to the system
14590 profile, and extends dbus with actions from @code{efl}.
14593 @deftp {Data Type} enlightenment-desktop-service-configuration
14595 @item @code{enlightenment} (default @code{enlightenment})
14596 The enlightenment package to use.
14600 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
14601 the default @code{%desktop-services} variable doesn't include any of
14602 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
14603 @code{%desktop-services} in the @code{services} field of your
14604 @code{operating-system}:
14607 (use-modules (gnu))
14608 (use-service-modules desktop)
14611 ;; cons* adds items to the list given as its last argument.
14612 (services (cons* (service gnome-desktop-service-type)
14613 (service xfce-desktop-service)
14614 %desktop-services))
14618 These desktop environments will then be available as options in the
14619 graphical login window.
14621 The actual service definitions included in @code{%desktop-services} and
14622 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
14623 are described below.
14625 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
14626 Return a service that runs the ``system bus'', using @var{dbus}, with
14627 support for @var{services}.
14629 @uref{http://dbus.freedesktop.org/, D-Bus} is an inter-process communication
14630 facility. Its system bus is used to allow system services to communicate
14631 and to be notified of system-wide events.
14633 @var{services} must be a list of packages that provide an
14634 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
14635 and policy files. For example, to allow avahi-daemon to use the system bus,
14636 @var{services} must be equal to @code{(list avahi)}.
14639 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
14640 Return a service that runs the @code{elogind} login and
14641 seat management daemon. @uref{https://github.com/elogind/elogind,
14642 Elogind} exposes a D-Bus interface that can be used to know which users
14643 are logged in, know what kind of sessions they have open, suspend the
14644 system, inhibit system suspend, reboot the system, and other tasks.
14646 Elogind handles most system-level power events for a computer, for
14647 example suspending the system when a lid is closed, or shutting it down
14648 when the power button is pressed.
14650 The @var{config} keyword argument specifies the configuration for
14651 elogind, and should be the result of an @code{(elogind-configuration
14652 (@var{parameter} @var{value})...)} invocation. Available parameters and
14653 their default values are:
14656 @item kill-user-processes?
14658 @item kill-only-users
14660 @item kill-exclude-users
14662 @item inhibit-delay-max-seconds
14664 @item handle-power-key
14666 @item handle-suspend-key
14668 @item handle-hibernate-key
14670 @item handle-lid-switch
14672 @item handle-lid-switch-docked
14674 @item power-key-ignore-inhibited?
14676 @item suspend-key-ignore-inhibited?
14678 @item hibernate-key-ignore-inhibited?
14680 @item lid-switch-ignore-inhibited?
14682 @item holdoff-timeout-seconds
14686 @item idle-action-seconds
14688 @item runtime-directory-size-percent
14690 @item runtime-directory-size
14694 @item suspend-state
14695 @code{("mem" "standby" "freeze")}
14698 @item hibernate-state
14700 @item hibernate-mode
14701 @code{("platform" "shutdown")}
14702 @item hybrid-sleep-state
14704 @item hybrid-sleep-mode
14705 @code{("suspend" "platform" "shutdown")}
14709 @deffn {Scheme Procedure} accountsservice-service @
14710 [#:accountsservice @var{accountsservice}]
14711 Return a service that runs AccountsService, a system service that can
14712 list available accounts, change their passwords, and so on.
14713 AccountsService integrates with PolicyKit to enable unprivileged users
14714 to acquire the capability to modify their system configuration.
14715 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
14716 accountsservice web site} for more information.
14718 The @var{accountsservice} keyword argument is the @code{accountsservice}
14719 package to expose as a service.
14722 @deffn {Scheme Procedure} polkit-service @
14723 [#:polkit @var{polkit}]
14724 Return a service that runs the
14725 @uref{http://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
14726 management service}, which allows system administrators to grant access to
14727 privileged operations in a structured way. By querying the Polkit service, a
14728 privileged system component can know when it should grant additional
14729 capabilities to ordinary users. For example, an ordinary user can be granted
14730 the capability to suspend the system if the user is logged in locally.
14733 @defvr {Scheme Variable} upower-service-type
14734 Service that runs @uref{http://upower.freedesktop.org/, @command{upowerd}}, a
14735 system-wide monitor for power consumption and battery levels, with the given
14736 configuration settings.
14738 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
14739 notably used by GNOME.
14742 @deftp {Data Type} upower-configuration
14743 Data type representation the configuration for UPower.
14747 @item @code{upower} (default: @var{upower})
14748 Package to use for @code{upower}.
14750 @item @code{watts-up-pro?} (default: @code{#f})
14751 Enable the Watts Up Pro device.
14753 @item @code{poll-batteries?} (default: @code{#t})
14754 Enable polling the kernel for battery level changes.
14756 @item @code{ignore-lid?} (default: @code{#f})
14757 Ignore the lid state, this can be useful if it's incorrect on a device.
14759 @item @code{use-percentage-for-policy?} (default: @code{#f})
14760 Whether battery percentage based policy should be used. The default is to use
14761 the time left, change to @code{#t} to use the percentage.
14763 @item @code{percentage-low} (default: @code{10})
14764 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14765 at which the battery is considered low.
14767 @item @code{percentage-critical} (default: @code{3})
14768 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14769 at which the battery is considered critical.
14771 @item @code{percentage-action} (default: @code{2})
14772 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14773 at which action will be taken.
14775 @item @code{time-low} (default: @code{1200})
14776 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14777 seconds at which the battery is considered low.
14779 @item @code{time-critical} (default: @code{300})
14780 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14781 seconds at which the battery is considered critical.
14783 @item @code{time-action} (default: @code{120})
14784 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14785 seconds at which action will be taken.
14787 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
14788 The action taken when @code{percentage-action} or @code{time-action} is
14789 reached (depending on the configuration of @code{use-percentage-for-policy?}).
14791 Possible values are:
14801 @code{'hybrid-sleep}.
14807 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
14808 Return a service for @uref{http://udisks.freedesktop.org/docs/latest/,
14809 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
14810 notifications and ways to mount/unmount disks. Programs that talk to UDisks
14811 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
14814 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
14815 Return a service that runs @command{colord}, a system service with a D-Bus
14816 interface to manage the color profiles of input and output devices such as
14817 screens and scanners. It is notably used by the GNOME Color Manager graphical
14818 tool. See @uref{http://www.freedesktop.org/software/colord/, the colord web
14819 site} for more information.
14822 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
14823 Return a configuration allowing an application to access GeoClue
14824 location data. @var{name} is the Desktop ID of the application, without
14825 the @code{.desktop} part. If @var{allowed?} is true, the application
14826 will have access to location information by default. The boolean
14827 @var{system?} value indicates whether an application is a system component
14828 or not. Finally @var{users} is a list of UIDs of all users for which
14829 this application is allowed location info access. An empty users list
14830 means that all users are allowed.
14833 @defvr {Scheme Variable} %standard-geoclue-applications
14834 The standard list of well-known GeoClue application configurations,
14835 granting authority to the GNOME date-and-time utility to ask for the
14836 current location in order to set the time zone, and allowing the
14837 IceCat and Epiphany web browsers to request location information.
14838 IceCat and Epiphany both query the user before allowing a web page to
14839 know the user's location.
14842 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
14843 [#:whitelist '()] @
14844 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
14845 [#:submit-data? #f]
14846 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
14847 [#:submission-nick "geoclue"] @
14848 [#:applications %standard-geoclue-applications]
14849 Return a service that runs the GeoClue location service. This service
14850 provides a D-Bus interface to allow applications to request access to a
14851 user's physical location, and optionally to add information to online
14852 location databases. See
14853 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
14854 web site} for more information.
14857 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
14858 [@w{#:auto-enable? #f}]
14859 Return a service that runs the @command{bluetoothd} daemon, which
14860 manages all the Bluetooth devices and provides a number of D-Bus
14861 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
14862 powered automatically at boot, which can be useful when using a
14863 bluetooth keyboard or mouse.
14865 Users need to be in the @code{lp} group to access the D-Bus service.
14868 @node Sound Services
14869 @subsection Sound Services
14871 @cindex sound support
14873 @cindex PulseAudio, sound support
14875 The @code{(gnu services sound)} module provides a service to configure the
14876 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
14877 preferred ALSA output driver.
14879 @deffn {Scheme Variable} alsa-service-type
14880 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
14881 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
14882 configuration file. The value for this type is a @command{alsa-configuration}
14883 record as in this example:
14886 (service alsa-service-type)
14889 See below for details about @code{alsa-configuration}.
14892 @deftp {Data Type} alsa-configuration
14893 Data type representing the configuration for @code{alsa-service}.
14896 @item @code{alsa-plugins} (default: @var{alsa-plugins})
14897 @code{alsa-plugins} package to use.
14899 @item @code{pulseaudio?} (default: @var{#t})
14900 Whether ALSA applications should transparently be made to use the
14901 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
14903 Using PulseAudio allows you to run several sound-producing applications
14904 at the same time and to individual control them @i{via}
14905 @command{pavucontrol}, among other things.
14907 @item @code{extra-options} (default: @var{""})
14908 String to append to the @file{/etc/asound.conf} file.
14913 Individual users who want to override the system configuration of ALSA can do
14914 it with the @file{~/.asoundrc} file:
14917 # In guix, we have to specify the absolute path for plugins.
14919 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
14922 # Routing ALSA to jack:
14923 # <http://jackaudio.org/faq/routing_alsa.html>.
14927 0 system:playback_1
14928 1 system:playback_2
14945 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
14949 @node Database Services
14950 @subsection Database Services
14954 The @code{(gnu services databases)} module provides the following services.
14956 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
14957 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
14958 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
14959 Return a service that runs @var{postgresql}, the PostgreSQL database
14962 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
14963 creates a database cluster with @var{locale} as the default
14964 locale, stored in @var{data-directory}. It then listens on @var{port}.
14966 @cindex postgresql extension-packages
14967 Additional extensions are loaded from packages listed in
14968 @var{extension-packages}. Extensions are available at runtime. For instance,
14969 to create a geographic database using the @code{postgis} extension, a user can
14970 configure the postgresql-service as in this example:
14974 (use-package-modules databases geo)
14978 ;; postgresql is required to run `psql' but postgis is not required for
14979 ;; proper operation.
14980 (packages (cons* postgresql %base-packages))
14983 (postgresql-service #:extension-packages (list postgis))
14987 Then the extension becomes visible and you can initialise an empty geographic
14988 database in this way:
14992 > create database postgistest;
14993 > \connect postgistest;
14994 > create extension postgis;
14995 > create extension postgis_topology;
14998 There is no need to add this field for contrib extensions such as hstore or
14999 dblink as they are already loadable by postgresql. This field is only
15000 required to add extensions provided by other packages.
15003 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
15004 Return a service that runs @command{mysqld}, the MySQL or MariaDB
15007 The optional @var{config} argument specifies the configuration for
15008 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
15011 @deftp {Data Type} mysql-configuration
15012 Data type representing the configuration of @var{mysql-service}.
15015 @item @code{mysql} (default: @var{mariadb})
15016 Package object of the MySQL database server, can be either @var{mariadb}
15019 For MySQL, a temporary root password will be displayed at activation time.
15020 For MariaDB, the root password is empty.
15022 @item @code{port} (default: @code{3306})
15023 TCP port on which the database server listens for incoming connections.
15027 @defvr {Scheme Variable} memcached-service-type
15028 This is the service type for the @uref{https://memcached.org/,
15029 Memcached} service, which provides a distributed in memory cache. The
15030 value for the service type is a @code{memcached-configuration} object.
15034 (service memcached-service-type)
15037 @deftp {Data Type} memcached-configuration
15038 Data type representing the configuration of memcached.
15041 @item @code{memcached} (default: @code{memcached})
15042 The Memcached package to use.
15044 @item @code{interfaces} (default: @code{'("0.0.0.0")})
15045 Network interfaces on which to listen.
15047 @item @code{tcp-port} (default: @code{11211})
15048 Port on which to accept connections on,
15050 @item @code{udp-port} (default: @code{11211})
15051 Port on which to accept UDP connections on, a value of 0 will disable
15052 listening on a UDP socket.
15054 @item @code{additional-options} (default: @code{'()})
15055 Additional command line options to pass to @code{memcached}.
15059 @defvr {Scheme Variable} mongodb-service-type
15060 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
15061 The value for the service type is a @code{mongodb-configuration} object.
15065 (service mongodb-service-type)
15068 @deftp {Data Type} mongodb-configuration
15069 Data type representing the configuration of mongodb.
15072 @item @code{mongodb} (default: @code{mongodb})
15073 The MongoDB package to use.
15075 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
15076 The configuration file for MongoDB.
15078 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
15079 This value is used to create the directory, so that it exists and is
15080 owned by the mongodb user. It should match the data-directory which
15081 MongoDB is configured to use through the configuration file.
15085 @defvr {Scheme Variable} redis-service-type
15086 This is the service type for the @uref{https://redis.io/, Redis}
15087 key/value store, whose value is a @code{redis-configuration} object.
15090 @deftp {Data Type} redis-configuration
15091 Data type representing the configuration of redis.
15094 @item @code{redis} (default: @code{redis})
15095 The Redis package to use.
15097 @item @code{bind} (default: @code{"127.0.0.1"})
15098 Network interface on which to listen.
15100 @item @code{port} (default: @code{6379})
15101 Port on which to accept connections on, a value of 0 will disable
15102 listening on a TCP socket.
15104 @item @code{working-directory} (default: @code{"/var/lib/redis"})
15105 Directory in which to store the database and related files.
15109 @node Mail Services
15110 @subsection Mail Services
15114 The @code{(gnu services mail)} module provides Guix service definitions
15115 for email services: IMAP, POP3, and LMTP servers, as well as mail
15116 transport agents (MTAs). Lots of acronyms! These services are detailed
15117 in the subsections below.
15119 @subsubheading Dovecot Service
15121 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
15122 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
15125 By default, Dovecot does not need much configuration; the default
15126 configuration object created by @code{(dovecot-configuration)} will
15127 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
15128 certificate will be generated for TLS-protected connections, though
15129 Dovecot will also listen on cleartext ports by default. There are a
15130 number of options, though, which mail administrators might need to change,
15131 and as is the case with other services, Guix allows the system
15132 administrator to specify these parameters via a uniform Scheme interface.
15134 For example, to specify that mail is located at @code{maildir~/.mail},
15135 one would instantiate the Dovecot service like this:
15138 (dovecot-service #:config
15139 (dovecot-configuration
15140 (mail-location "maildir:~/.mail")))
15143 The available configuration parameters follow. Each parameter
15144 definition is preceded by its type; for example, @samp{string-list foo}
15145 indicates that the @code{foo} parameter should be specified as a list of
15146 strings. There is also a way to specify the configuration as a string,
15147 if you have an old @code{dovecot.conf} file that you want to port over
15148 from some other system; see the end for more details.
15150 @c The following documentation was initially generated by
15151 @c (generate-documentation) in (gnu services mail). Manually maintained
15152 @c documentation is better, so we shouldn't hesitate to edit below as
15153 @c needed. However if the change you want to make to this documentation
15154 @c can be done in an automated way, it's probably easier to change
15155 @c (generate-documentation) than to make it below and have to deal with
15156 @c the churn as dovecot updates.
15158 Available @code{dovecot-configuration} fields are:
15160 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
15161 The dovecot package.
15164 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
15165 A list of IPs or hosts where to listen for connections. @samp{*}
15166 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
15167 interfaces. If you want to specify non-default ports or anything more
15168 complex, customize the address and port fields of the
15169 @samp{inet-listener} of the specific services you are interested in.
15172 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
15173 List of protocols we want to serve. Available protocols include
15174 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
15176 Available @code{protocol-configuration} fields are:
15178 @deftypevr {@code{protocol-configuration} parameter} string name
15179 The name of the protocol.
15182 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
15183 UNIX socket path to the master authentication server to find users.
15184 This is used by imap (for shared users) and lda.
15185 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
15188 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
15189 Space separated list of plugins to load.
15192 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
15193 Maximum number of IMAP connections allowed for a user from each IP
15194 address. NOTE: The username is compared case-sensitively.
15195 Defaults to @samp{10}.
15200 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
15201 List of services to enable. Available services include @samp{imap},
15202 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
15205 Available @code{service-configuration} fields are:
15207 @deftypevr {@code{service-configuration} parameter} string kind
15208 The service kind. Valid values include @code{director},
15209 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
15210 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
15211 @code{tcpwrap}, @code{quota-warning}, or anything else.
15214 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
15215 Listeners for the service. A listener is either a
15216 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
15217 an @code{inet-listener-configuration}.
15218 Defaults to @samp{()}.
15220 Available @code{unix-listener-configuration} fields are:
15222 @deftypevr {@code{unix-listener-configuration} parameter} string path
15223 Path to the file, relative to @code{base-dir} field. This is also used as
15227 @deftypevr {@code{unix-listener-configuration} parameter} string mode
15228 The access mode for the socket.
15229 Defaults to @samp{"0600"}.
15232 @deftypevr {@code{unix-listener-configuration} parameter} string user
15233 The user to own the socket.
15234 Defaults to @samp{""}.
15237 @deftypevr {@code{unix-listener-configuration} parameter} string group
15238 The group to own the socket.
15239 Defaults to @samp{""}.
15243 Available @code{fifo-listener-configuration} fields are:
15245 @deftypevr {@code{fifo-listener-configuration} parameter} string path
15246 Path to the file, relative to @code{base-dir} field. This is also used as
15250 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
15251 The access mode for the socket.
15252 Defaults to @samp{"0600"}.
15255 @deftypevr {@code{fifo-listener-configuration} parameter} string user
15256 The user to own the socket.
15257 Defaults to @samp{""}.
15260 @deftypevr {@code{fifo-listener-configuration} parameter} string group
15261 The group to own the socket.
15262 Defaults to @samp{""}.
15266 Available @code{inet-listener-configuration} fields are:
15268 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
15269 The protocol to listen for.
15272 @deftypevr {@code{inet-listener-configuration} parameter} string address
15273 The address on which to listen, or empty for all addresses.
15274 Defaults to @samp{""}.
15277 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
15278 The port on which to listen.
15281 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
15282 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
15284 Defaults to @samp{#t}.
15289 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
15290 Maximum number of simultaneous client connections per process. Once
15291 this number of connections is received, the next incoming connection
15292 will prompt Dovecot to spawn another process. If set to 0,
15293 @code{default-client-limit} is used instead.
15295 Defaults to @samp{0}.
15299 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
15300 Number of connections to handle before starting a new process.
15301 Typically the only useful values are 0 (unlimited) or 1. 1 is more
15302 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
15303 Defaults to @samp{1}.
15307 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
15308 Maximum number of processes that can exist for this service. If set to
15309 0, @code{default-process-limit} is used instead.
15311 Defaults to @samp{0}.
15315 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
15316 Number of processes to always keep waiting for more connections.
15317 Defaults to @samp{0}.
15320 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
15321 If you set @samp{service-count 0}, you probably need to grow
15323 Defaults to @samp{256000000}.
15328 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
15329 Dict configuration, as created by the @code{dict-configuration}
15332 Available @code{dict-configuration} fields are:
15334 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
15335 A list of key-value pairs that this dict should hold.
15336 Defaults to @samp{()}.
15341 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
15342 A list of passdb configurations, each one created by the
15343 @code{passdb-configuration} constructor.
15345 Available @code{passdb-configuration} fields are:
15347 @deftypevr {@code{passdb-configuration} parameter} string driver
15348 The driver that the passdb should use. Valid values include
15349 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
15351 Defaults to @samp{"pam"}.
15354 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
15355 Space separated list of arguments to the passdb driver.
15356 Defaults to @samp{""}.
15361 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
15362 List of userdb configurations, each one created by the
15363 @code{userdb-configuration} constructor.
15365 Available @code{userdb-configuration} fields are:
15367 @deftypevr {@code{userdb-configuration} parameter} string driver
15368 The driver that the userdb should use. Valid values include
15369 @samp{passwd} and @samp{static}.
15370 Defaults to @samp{"passwd"}.
15373 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
15374 Space separated list of arguments to the userdb driver.
15375 Defaults to @samp{""}.
15378 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
15379 Override fields from passwd.
15380 Defaults to @samp{()}.
15385 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
15386 Plug-in configuration, created by the @code{plugin-configuration}
15390 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
15391 List of namespaces. Each item in the list is created by the
15392 @code{namespace-configuration} constructor.
15394 Available @code{namespace-configuration} fields are:
15396 @deftypevr {@code{namespace-configuration} parameter} string name
15397 Name for this namespace.
15400 @deftypevr {@code{namespace-configuration} parameter} string type
15401 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
15402 Defaults to @samp{"private"}.
15405 @deftypevr {@code{namespace-configuration} parameter} string separator
15406 Hierarchy separator to use. You should use the same separator for
15407 all namespaces or some clients get confused. @samp{/} is usually a good
15408 one. The default however depends on the underlying mail storage
15410 Defaults to @samp{""}.
15413 @deftypevr {@code{namespace-configuration} parameter} string prefix
15414 Prefix required to access this namespace. This needs to be
15415 different for all namespaces. For example @samp{Public/}.
15416 Defaults to @samp{""}.
15419 @deftypevr {@code{namespace-configuration} parameter} string location
15420 Physical location of the mailbox. This is in the same format as
15421 mail_location, which is also the default for it.
15422 Defaults to @samp{""}.
15425 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
15426 There can be only one INBOX, and this setting defines which
15428 Defaults to @samp{#f}.
15431 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
15432 If namespace is hidden, it's not advertised to clients via NAMESPACE
15433 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
15434 useful when converting from another server with different namespaces
15435 which you want to deprecate but still keep working. For example you can
15436 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
15438 Defaults to @samp{#f}.
15441 @deftypevr {@code{namespace-configuration} parameter} boolean list?
15442 Show the mailboxes under this namespace with the LIST command. This
15443 makes the namespace visible for clients that do not support the NAMESPACE
15444 extension. The special @code{children} value lists child mailboxes, but
15445 hides the namespace prefix.
15446 Defaults to @samp{#t}.
15449 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
15450 Namespace handles its own subscriptions. If set to @code{#f}, the
15451 parent namespace handles them. The empty prefix should always have this
15453 Defaults to @samp{#t}.
15456 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
15457 List of predefined mailboxes in this namespace.
15458 Defaults to @samp{()}.
15460 Available @code{mailbox-configuration} fields are:
15462 @deftypevr {@code{mailbox-configuration} parameter} string name
15463 Name for this mailbox.
15466 @deftypevr {@code{mailbox-configuration} parameter} string auto
15467 @samp{create} will automatically create this mailbox.
15468 @samp{subscribe} will both create and subscribe to the mailbox.
15469 Defaults to @samp{"no"}.
15472 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
15473 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
15474 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
15475 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
15476 Defaults to @samp{()}.
15483 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
15484 Base directory where to store runtime data.
15485 Defaults to @samp{"/var/run/dovecot/"}.
15488 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
15489 Greeting message for clients.
15490 Defaults to @samp{"Dovecot ready."}.
15493 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
15494 List of trusted network ranges. Connections from these IPs are
15495 allowed to override their IP addresses and ports (for logging and for
15496 authentication checks). @samp{disable-plaintext-auth} is also ignored
15497 for these networks. Typically you would specify your IMAP proxy servers
15499 Defaults to @samp{()}.
15502 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
15503 List of login access check sockets (e.g.@: tcpwrap).
15504 Defaults to @samp{()}.
15507 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
15508 Show more verbose process titles (in ps). Currently shows user name
15509 and IP address. Useful for seeing who is actually using the IMAP
15510 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
15512 Defaults to @samp{#f}.
15515 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
15516 Should all processes be killed when Dovecot master process shuts down.
15517 Setting this to @code{#f} means that Dovecot can be upgraded without
15518 forcing existing client connections to close (although that could also
15519 be a problem if the upgrade is e.g.@: due to a security fix).
15520 Defaults to @samp{#t}.
15523 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
15524 If non-zero, run mail commands via this many connections to doveadm
15525 server, instead of running them directly in the same process.
15526 Defaults to @samp{0}.
15529 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
15530 UNIX socket or host:port used for connecting to doveadm server.
15531 Defaults to @samp{"doveadm-server"}.
15534 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
15535 List of environment variables that are preserved on Dovecot startup
15536 and passed down to all of its child processes. You can also give
15537 key=value pairs to always set specific settings.
15540 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
15541 Disable LOGIN command and all other plaintext authentications unless
15542 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
15543 matches the local IP (i.e.@: you're connecting from the same computer),
15544 the connection is considered secure and plaintext authentication is
15545 allowed. See also ssl=required setting.
15546 Defaults to @samp{#t}.
15549 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
15550 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
15551 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
15552 for caching to be used.
15553 Defaults to @samp{0}.
15556 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
15557 Time to live for cached data. After TTL expires the cached record
15558 is no longer used, *except* if the main database lookup returns internal
15559 failure. We also try to handle password changes automatically: If
15560 user's previous authentication was successful, but this one wasn't, the
15561 cache isn't used. For now this works only with plaintext
15563 Defaults to @samp{"1 hour"}.
15566 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
15567 TTL for negative hits (user not found, password mismatch).
15568 0 disables caching them completely.
15569 Defaults to @samp{"1 hour"}.
15572 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
15573 List of realms for SASL authentication mechanisms that need them.
15574 You can leave it empty if you don't want to support multiple realms.
15575 Many clients simply use the first one listed here, so keep the default
15577 Defaults to @samp{()}.
15580 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
15581 Default realm/domain to use if none was specified. This is used for
15582 both SASL realms and appending @@domain to username in plaintext
15584 Defaults to @samp{""}.
15587 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
15588 List of allowed characters in username. If the user-given username
15589 contains a character not listed in here, the login automatically fails.
15590 This is just an extra check to make sure user can't exploit any
15591 potential quote escaping vulnerabilities with SQL/LDAP databases. If
15592 you want to allow all characters, set this value to empty.
15593 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
15596 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
15597 Username character translations before it's looked up from
15598 databases. The value contains series of from -> to characters. For
15599 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
15600 translated to @samp{@@}.
15601 Defaults to @samp{""}.
15604 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
15605 Username formatting before it's looked up from databases. You can
15606 use the standard variables here, e.g.@: %Lu would lowercase the username,
15607 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
15608 change the @samp{@@} into @samp{-AT-}. This translation is done after
15609 @samp{auth-username-translation} changes.
15610 Defaults to @samp{"%Lu"}.
15613 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
15614 If you want to allow master users to log in by specifying the master
15615 username within the normal username string (i.e.@: not using SASL
15616 mechanism's support for it), you can specify the separator character
15617 here. The format is then <username><separator><master username>.
15618 UW-IMAP uses @samp{*} as the separator, so that could be a good
15620 Defaults to @samp{""}.
15623 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
15624 Username to use for users logging in with ANONYMOUS SASL
15626 Defaults to @samp{"anonymous"}.
15629 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
15630 Maximum number of dovecot-auth worker processes. They're used to
15631 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
15632 They're automatically created and destroyed as needed.
15633 Defaults to @samp{30}.
15636 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
15637 Host name to use in GSSAPI principal names. The default is to use
15638 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
15639 allow all keytab entries.
15640 Defaults to @samp{""}.
15643 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
15644 Kerberos keytab to use for the GSSAPI mechanism. Will use the
15645 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
15646 need to change the auth service to run as root to be able to read this
15648 Defaults to @samp{""}.
15651 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
15652 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
15653 and @samp{ntlm-auth} helper.
15654 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
15655 Defaults to @samp{#f}.
15658 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
15659 Path for Samba's @samp{ntlm-auth} helper binary.
15660 Defaults to @samp{"/usr/bin/ntlm_auth"}.
15663 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
15664 Time to delay before replying to failed authentications.
15665 Defaults to @samp{"2 secs"}.
15668 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
15669 Require a valid SSL client certificate or the authentication
15671 Defaults to @samp{#f}.
15674 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
15675 Take the username from client's SSL certificate, using
15676 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
15678 Defaults to @samp{#f}.
15681 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
15682 List of wanted authentication mechanisms. Supported mechanisms are:
15683 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
15684 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
15685 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
15686 @samp{disable-plaintext-auth} setting.
15689 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
15690 List of IPs or hostnames to all director servers, including ourself.
15691 Ports can be specified as ip:port. The default port is the same as what
15692 director service's @samp{inet-listener} is using.
15693 Defaults to @samp{()}.
15696 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
15697 List of IPs or hostnames to all backend mail servers. Ranges are
15698 allowed too, like 10.0.0.10-10.0.0.30.
15699 Defaults to @samp{()}.
15702 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
15703 How long to redirect users to a specific server after it no longer
15704 has any connections.
15705 Defaults to @samp{"15 min"}.
15708 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
15709 How the username is translated before being hashed. Useful values
15710 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
15711 are shared within domain.
15712 Defaults to @samp{"%Lu"}.
15715 @deftypevr {@code{dovecot-configuration} parameter} string log-path
15716 Log file to use for error messages. @samp{syslog} logs to syslog,
15717 @samp{/dev/stderr} logs to stderr.
15718 Defaults to @samp{"syslog"}.
15721 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
15722 Log file to use for informational messages. Defaults to
15724 Defaults to @samp{""}.
15727 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
15728 Log file to use for debug messages. Defaults to
15729 @samp{info-log-path}.
15730 Defaults to @samp{""}.
15733 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
15734 Syslog facility to use if you're logging to syslog. Usually if you
15735 don't want to use @samp{mail}, you'll use local0..local7. Also other
15736 standard facilities are supported.
15737 Defaults to @samp{"mail"}.
15740 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
15741 Log unsuccessful authentication attempts and the reasons why they
15743 Defaults to @samp{#f}.
15746 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose-passwords?
15747 In case of password mismatches, log the attempted password. Valid
15748 values are no, plain and sha1. sha1 can be useful for detecting brute
15749 force password attempts vs. user simply trying the same password over
15750 and over again. You can also truncate the value to n chars by appending
15751 ":n" (e.g.@: sha1:6).
15752 Defaults to @samp{#f}.
15755 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
15756 Even more verbose logging for debugging purposes. Shows for example
15758 Defaults to @samp{#f}.
15761 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
15762 In case of password mismatches, log the passwords and used scheme so
15763 the problem can be debugged. Enabling this also enables
15765 Defaults to @samp{#f}.
15768 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
15769 Enable mail process debugging. This can help you figure out why
15770 Dovecot isn't finding your mails.
15771 Defaults to @samp{#f}.
15774 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
15775 Show protocol level SSL errors.
15776 Defaults to @samp{#f}.
15779 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
15780 Prefix for each line written to log file. % codes are in
15781 strftime(3) format.
15782 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
15785 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
15786 List of elements we want to log. The elements which have a
15787 non-empty variable value are joined together to form a comma-separated
15791 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
15792 Login log format. %s contains @samp{login-log-format-elements}
15793 string, %$ contains the data we want to log.
15794 Defaults to @samp{"%$: %s"}.
15797 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
15798 Log prefix for mail processes. See doc/wiki/Variables.txt for list
15799 of possible variables you can use.
15800 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
15803 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
15804 Format to use for logging mail deliveries. You can use variables:
15807 Delivery status message (e.g.@: @samp{saved to INBOX})
15819 Defaults to @samp{"msgid=%m: %$"}.
15822 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
15823 Location for users' mailboxes. The default is empty, which means
15824 that Dovecot tries to find the mailboxes automatically. This won't work
15825 if the user doesn't yet have any mail, so you should explicitly tell
15826 Dovecot the full location.
15828 If you're using mbox, giving a path to the INBOX
15829 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
15830 where the other mailboxes are kept. This is called the "root mail
15831 directory", and it must be the first path given in the
15832 @samp{mail-location} setting.
15834 There are a few special variables you can use, eg.:
15840 user part in user@@domain, same as %u if there's no domain
15842 domain part in user@@domain, empty if there's no domain
15847 See doc/wiki/Variables.txt for full list. Some examples:
15849 @item maildir:~/Maildir
15850 @item mbox:~/mail:INBOX=/var/mail/%u
15851 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
15853 Defaults to @samp{""}.
15856 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
15857 System user and group used to access mails. If you use multiple,
15858 userdb can override these by returning uid or gid fields. You can use
15859 either numbers or names. <doc/wiki/UserIds.txt>.
15860 Defaults to @samp{""}.
15863 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
15865 Defaults to @samp{""}.
15868 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
15869 Group to enable temporarily for privileged operations. Currently
15870 this is used only with INBOX when either its initial creation or
15871 dotlocking fails. Typically this is set to "mail" to give access to
15873 Defaults to @samp{""}.
15876 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
15877 Grant access to these supplementary groups for mail processes.
15878 Typically these are used to set up access to shared mailboxes. Note
15879 that it may be dangerous to set these if users can create
15880 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
15881 could allow a user to delete others' mailboxes, or ln -s
15882 /secret/shared/box ~/mail/mybox would allow reading it).
15883 Defaults to @samp{""}.
15886 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
15887 Allow full file system access to clients. There's no access checks
15888 other than what the operating system does for the active UID/GID. It
15889 works with both maildir and mboxes, allowing you to prefix mailboxes
15890 names with e.g.@: /path/ or ~user/.
15891 Defaults to @samp{#f}.
15894 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
15895 Don't use mmap() at all. This is required if you store indexes to
15896 shared file systems (NFS or clustered file system).
15897 Defaults to @samp{#f}.
15900 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
15901 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
15902 supports @samp{O_EXCL} since version 3, so this should be safe to use
15903 nowadays by default.
15904 Defaults to @samp{#t}.
15907 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
15908 When to use fsync() or fdatasync() calls:
15911 Whenever necessary to avoid losing important data
15913 Useful with e.g.@: NFS when write()s are delayed
15915 Never use it (best performance, but crashes can lose data).
15917 Defaults to @samp{"optimized"}.
15920 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
15921 Mail storage exists in NFS. Set this to yes to make Dovecot flush
15922 NFS caches whenever needed. If you're using only a single mail server
15924 Defaults to @samp{#f}.
15927 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
15928 Mail index files also exist in NFS. Setting this to yes requires
15929 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
15930 Defaults to @samp{#f}.
15933 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
15934 Locking method for index files. Alternatives are fcntl, flock and
15935 dotlock. Dotlocking uses some tricks which may create more disk I/O
15936 than other locking methods. NFS users: flock doesn't work, remember to
15937 change @samp{mmap-disable}.
15938 Defaults to @samp{"fcntl"}.
15941 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
15942 Directory in which LDA/LMTP temporarily stores incoming mails >128
15944 Defaults to @samp{"/tmp"}.
15947 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
15948 Valid UID range for users. This is mostly to make sure that users can't
15949 log in as daemons or other system users. Note that denying root logins is
15950 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
15952 Defaults to @samp{500}.
15955 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
15957 Defaults to @samp{0}.
15960 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
15961 Valid GID range for users. Users having non-valid GID as primary group ID
15962 aren't allowed to log in. If user belongs to supplementary groups with
15963 non-valid GIDs, those groups are not set.
15964 Defaults to @samp{1}.
15967 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
15969 Defaults to @samp{0}.
15972 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
15973 Maximum allowed length for mail keyword name. It's only forced when
15974 trying to create new keywords.
15975 Defaults to @samp{50}.
15978 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
15979 List of directories under which chrooting is allowed for mail
15980 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
15981 too). This setting doesn't affect @samp{login-chroot}
15982 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
15983 "/./" in home dirs are ignored. WARNING: Never add directories here
15984 which local users can modify, that may lead to root exploit. Usually
15985 this should be done only if you don't allow shell access for users.
15986 <doc/wiki/Chrooting.txt>.
15987 Defaults to @samp{()}.
15990 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
15991 Default chroot directory for mail processes. This can be overridden
15992 for specific users in user database by giving /./ in user's home
15993 directory (e.g.@: /home/./user chroots into /home). Note that usually
15994 there is no real need to do chrooting, Dovecot doesn't allow users to
15995 access files outside their mail directory anyway. If your home
15996 directories are prefixed with the chroot directory, append "/."@: to
15997 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
15998 Defaults to @samp{""}.
16001 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
16002 UNIX socket path to master authentication server to find users.
16003 This is used by imap (for shared users) and lda.
16004 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16007 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
16008 Directory where to look up mail plugins.
16009 Defaults to @samp{"/usr/lib/dovecot"}.
16012 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
16013 List of plugins to load for all services. Plugins specific to IMAP,
16014 LDA, etc.@: are added to this list in their own .conf files.
16015 Defaults to @samp{()}.
16018 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
16019 The minimum number of mails in a mailbox before updates are done to
16020 cache file. This allows optimizing Dovecot's behavior to do less disk
16021 writes at the cost of more disk reads.
16022 Defaults to @samp{0}.
16025 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
16026 When IDLE command is running, mailbox is checked once in a while to
16027 see if there are any new mails or other changes. This setting defines
16028 the minimum time to wait between those checks. Dovecot can also use
16029 dnotify, inotify and kqueue to find out immediately when changes
16031 Defaults to @samp{"30 secs"}.
16034 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
16035 Save mails with CR+LF instead of plain LF. This makes sending those
16036 mails take less CPU, especially with sendfile() syscall with Linux and
16037 FreeBSD. But it also creates a bit more disk I/O which may just make it
16038 slower. Also note that if other software reads the mboxes/maildirs,
16039 they may handle the extra CRs wrong and cause problems.
16040 Defaults to @samp{#f}.
16043 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
16044 By default LIST command returns all entries in maildir beginning
16045 with a dot. Enabling this option makes Dovecot return only entries
16046 which are directories. This is done by stat()ing each entry, so it
16047 causes more disk I/O.
16048 (For systems setting struct @samp{dirent->d_type} this check is free
16049 and it's done always regardless of this setting).
16050 Defaults to @samp{#f}.
16053 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
16054 When copying a message, do it with hard links whenever possible.
16055 This makes the performance much better, and it's unlikely to have any
16057 Defaults to @samp{#t}.
16060 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
16061 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
16062 directory only when its mtime changes unexpectedly or when we can't find
16063 the mail otherwise.
16064 Defaults to @samp{#f}.
16067 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
16068 Which locking methods to use for locking mbox. There are four
16073 Create <mailbox>.lock file. This is the oldest and most NFS-safe
16074 solution. If you want to use /var/mail/ like directory, the users will
16075 need write access to that directory.
16077 Same as dotlock, but if it fails because of permissions or because there
16078 isn't enough disk space, just skip it.
16080 Use this if possible. Works with NFS too if lockd is used.
16082 May not exist in all systems. Doesn't work with NFS.
16084 May not exist in all systems. Doesn't work with NFS.
16087 You can use multiple locking methods; if you do the order they're declared
16088 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
16089 locking methods as well. Some operating systems don't allow using some of
16090 them simultaneously.
16093 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
16097 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
16098 Maximum time to wait for lock (all of them) before aborting.
16099 Defaults to @samp{"5 mins"}.
16102 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
16103 If dotlock exists but the mailbox isn't modified in any way,
16104 override the lock file after this much time.
16105 Defaults to @samp{"2 mins"}.
16108 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
16109 When mbox changes unexpectedly we have to fully read it to find out
16110 what changed. If the mbox is large this can take a long time. Since
16111 the change is usually just a newly appended mail, it'd be faster to
16112 simply read the new mails. If this setting is enabled, Dovecot does
16113 this but still safely fallbacks to re-reading the whole mbox file
16114 whenever something in mbox isn't how it's expected to be. The only real
16115 downside to this setting is that if some other MUA changes message
16116 flags, Dovecot doesn't notice it immediately. Note that a full sync is
16117 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
16118 Defaults to @samp{#t}.
16121 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
16122 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
16123 EXAMINE, EXPUNGE or CHECK commands. If this is set,
16124 @samp{mbox-dirty-syncs} is ignored.
16125 Defaults to @samp{#f}.
16128 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
16129 Delay writing mbox headers until doing a full write sync (EXPUNGE
16130 and CHECK commands and when closing the mailbox). This is especially
16131 useful for POP3 where clients often delete all mails. The downside is
16132 that our changes aren't immediately visible to other MUAs.
16133 Defaults to @samp{#t}.
16136 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
16137 If mbox size is smaller than this (e.g.@: 100k), don't write index
16138 files. If an index file already exists it's still read, just not
16140 Defaults to @samp{0}.
16143 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
16144 Maximum dbox file size until it's rotated.
16145 Defaults to @samp{10000000}.
16148 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
16149 Maximum dbox file age until it's rotated. Typically in days. Day
16150 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
16152 Defaults to @samp{"1d"}.
16155 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
16156 When creating new mdbox files, immediately preallocate their size to
16157 @samp{mdbox-rotate-size}. This setting currently works only in Linux
16158 with some file systems (ext4, xfs).
16159 Defaults to @samp{#f}.
16162 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
16163 sdbox and mdbox support saving mail attachments to external files,
16164 which also allows single instance storage for them. Other backends
16165 don't support this for now.
16167 WARNING: This feature hasn't been tested much yet. Use at your own risk.
16169 Directory root where to store mail attachments. Disabled, if empty.
16170 Defaults to @samp{""}.
16173 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
16174 Attachments smaller than this aren't saved externally. It's also
16175 possible to write a plugin to disable saving specific attachments
16177 Defaults to @samp{128000}.
16180 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
16181 File system backend to use for saving attachments:
16184 No SiS done by Dovecot (but this might help FS's own deduplication)
16186 SiS with immediate byte-by-byte comparison during saving
16187 @item sis-queue posix
16188 SiS with delayed comparison and deduplication.
16190 Defaults to @samp{"sis posix"}.
16193 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
16194 Hash format to use in attachment filenames. You can add any text and
16195 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
16196 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
16197 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
16198 Defaults to @samp{"%@{sha1@}"}.
16201 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
16203 Defaults to @samp{100}.
16206 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
16208 Defaults to @samp{1000}.
16211 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
16212 Default VSZ (virtual memory size) limit for service processes.
16213 This is mainly intended to catch and kill processes that leak memory
16214 before they eat up everything.
16215 Defaults to @samp{256000000}.
16218 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
16219 Login user is internally used by login processes. This is the most
16220 untrusted user in Dovecot system. It shouldn't have access to anything
16222 Defaults to @samp{"dovenull"}.
16225 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
16226 Internal user is used by unprivileged processes. It should be
16227 separate from login user, so that login processes can't disturb other
16229 Defaults to @samp{"dovecot"}.
16232 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
16233 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
16234 Defaults to @samp{"required"}.
16237 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
16238 PEM encoded X.509 SSL/TLS certificate (public key).
16239 Defaults to @samp{"</etc/dovecot/default.pem"}.
16242 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
16243 PEM encoded SSL/TLS private key. The key is opened before
16244 dropping root privileges, so keep the key file unreadable by anyone but
16246 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
16249 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
16250 If key file is password protected, give the password here.
16251 Alternatively give it when starting dovecot with -p parameter. Since
16252 this file is often world-readable, you may want to place this setting
16253 instead to a different.
16254 Defaults to @samp{""}.
16257 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
16258 PEM encoded trusted certificate authority. Set this only if you
16259 intend to use @samp{ssl-verify-client-cert? #t}. The file should
16260 contain the CA certificate(s) followed by the matching
16261 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
16262 Defaults to @samp{""}.
16265 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
16266 Require that CRL check succeeds for client certificates.
16267 Defaults to @samp{#t}.
16270 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
16271 Request client to send a certificate. If you also want to require
16272 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
16273 Defaults to @samp{#f}.
16276 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
16277 Which field from certificate to use for username. commonName and
16278 x500UniqueIdentifier are the usual choices. You'll also need to set
16279 @samp{auth-ssl-username-from-cert? #t}.
16280 Defaults to @samp{"commonName"}.
16283 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
16284 Minimum SSL protocol version to accept.
16285 Defaults to @samp{"TLSv1"}.
16288 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
16289 SSL ciphers to use.
16290 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
16293 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
16294 SSL crypto device to use, for valid values run "openssl engine".
16295 Defaults to @samp{""}.
16298 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
16299 Address to use when sending rejection mails.
16300 %d expands to recipient domain.
16301 Defaults to @samp{"postmaster@@%d"}.
16304 @deftypevr {@code{dovecot-configuration} parameter} string hostname
16305 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
16306 and in LMTP replies. Default is the system's real hostname@@domain.
16307 Defaults to @samp{""}.
16310 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
16311 If user is over quota, return with temporary failure instead of
16313 Defaults to @samp{#f}.
16316 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
16317 Binary to use for sending mails.
16318 Defaults to @samp{"/usr/sbin/sendmail"}.
16321 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
16322 If non-empty, send mails via this SMTP host[:port] instead of
16324 Defaults to @samp{""}.
16327 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
16328 Subject: header to use for rejection mails. You can use the same
16329 variables as for @samp{rejection-reason} below.
16330 Defaults to @samp{"Rejected: %s"}.
16333 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
16334 Human readable error message for rejection mails. You can use
16347 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
16350 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
16351 Delimiter character between local-part and detail in email
16353 Defaults to @samp{"+"}.
16356 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
16357 Header where the original recipient address (SMTP's RCPT TO:
16358 address) is taken from if not available elsewhere. With dovecot-lda -a
16359 parameter overrides this. A commonly used header for this is
16361 Defaults to @samp{""}.
16364 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
16365 Should saving a mail to a nonexistent mailbox automatically create
16367 Defaults to @samp{#f}.
16370 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
16371 Should automatically created mailboxes be also automatically
16373 Defaults to @samp{#f}.
16376 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
16377 Maximum IMAP command line length. Some clients generate very long
16378 command lines with huge mailboxes, so you may need to raise this if you
16379 get "Too long argument" or "IMAP command line too large" errors
16381 Defaults to @samp{64000}.
16384 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
16385 IMAP logout format string:
16388 total number of bytes read from client
16390 total number of bytes sent to client.
16392 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
16393 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@}"}.
16396 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
16397 Override the IMAP CAPABILITY response. If the value begins with '+',
16398 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
16399 Defaults to @samp{""}.
16402 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
16403 How long to wait between "OK Still here" notifications when client
16405 Defaults to @samp{"2 mins"}.
16408 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
16409 ID field names and values to send to clients. Using * as the value
16410 makes Dovecot use the default value. The following fields have default
16411 values currently: name, version, os, os-version, support-url,
16413 Defaults to @samp{""}.
16416 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
16417 ID fields sent by client to log. * means everything.
16418 Defaults to @samp{""}.
16421 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
16422 Workarounds for various client bugs:
16425 @item delay-newmail
16426 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
16427 CHECK commands. Some clients ignore them otherwise, for example OSX
16428 Mail (<v2.1). Outlook Express breaks more badly though, without this it
16429 may show user "Message no longer in server" errors. Note that OE6
16430 still breaks even with this workaround if synchronization is set to
16433 @item tb-extra-mailbox-sep
16434 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
16435 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
16436 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
16438 @item tb-lsub-flags
16439 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
16440 This makes Thunderbird realize they aren't selectable and show them
16441 greyed out, instead of only later giving "not selectable" popup error.
16443 Defaults to @samp{()}.
16446 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
16447 Host allowed in URLAUTH URLs sent by client. "*" allows all.
16448 Defaults to @samp{""}.
16452 Whew! Lots of configuration options. The nice thing about it though is
16453 that Guix has a complete interface to Dovecot's configuration
16454 language. This allows not only a nice way to declare configurations,
16455 but also offers reflective capabilities as well: users can write code to
16456 inspect and transform configurations from within Scheme.
16458 However, it could be that you just want to get a @code{dovecot.conf} up
16459 and running. In that case, you can pass an
16460 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
16461 @code{dovecot-service}. As its name indicates, an opaque configuration
16462 does not have easy reflective capabilities.
16464 Available @code{opaque-dovecot-configuration} fields are:
16466 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
16467 The dovecot package.
16470 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
16471 The contents of the @code{dovecot.conf}, as a string.
16474 For example, if your @code{dovecot.conf} is just the empty string, you
16475 could instantiate a dovecot service like this:
16478 (dovecot-service #:config
16479 (opaque-dovecot-configuration
16483 @subsubheading OpenSMTPD Service
16485 @deffn {Scheme Variable} opensmtpd-service-type
16486 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
16487 service, whose value should be an @code{opensmtpd-configuration} object
16488 as in this example:
16491 (service opensmtpd-service-type
16492 (opensmtpd-configuration
16493 (config-file (local-file "./my-smtpd.conf"))))
16497 @deftp {Data Type} opensmtpd-configuration
16498 Data type representing the configuration of opensmtpd.
16501 @item @code{package} (default: @var{opensmtpd})
16502 Package object of the OpenSMTPD SMTP server.
16504 @item @code{config-file} (default: @var{%default-opensmtpd-file})
16505 File-like object of the OpenSMTPD configuration file to use. By default
16506 it listens on the loopback network interface, and allows for mail from
16507 users and daemons on the local machine, as well as permitting email to
16508 remote servers. Run @command{man smtpd.conf} for more information.
16513 @subsubheading Exim Service
16515 @cindex mail transfer agent (MTA)
16516 @cindex MTA (mail transfer agent)
16519 @deffn {Scheme Variable} exim-service-type
16520 This is the type of the @uref{https://exim.org, Exim} mail transfer
16521 agent (MTA), whose value should be an @code{exim-configuration} object
16522 as in this example:
16525 (service exim-service-type
16526 (exim-configuration
16527 (config-file (local-file "./my-exim.conf"))))
16531 In order to use an @code{exim-service-type} service you must also have a
16532 @code{mail-aliases-service-type} service present in your
16533 @code{operating-system} (even if it has no aliases).
16535 @deftp {Data Type} exim-configuration
16536 Data type representing the configuration of exim.
16539 @item @code{package} (default: @var{exim})
16540 Package object of the Exim server.
16542 @item @code{config-file} (default: @code{#f})
16543 File-like object of the Exim configuration file to use. If its value is
16544 @code{#f} then use the default configuration file from the package
16545 provided in @code{package}. The resulting configuration file is loaded
16546 after setting the @code{exim_user} and @code{exim_group} configuration
16552 @subsubheading Mail Aliases Service
16554 @cindex email aliases
16555 @cindex aliases, for email addresses
16557 @deffn {Scheme Variable} mail-aliases-service-type
16558 This is the type of the service which provides @code{/etc/aliases},
16559 specifying how to deliver mail to users on this system.
16562 (service mail-aliases-service-type
16563 '(("postmaster" "bob")
16564 ("bob" "bob@@example.com" "bob@@example2.com")))
16568 The configuration for a @code{mail-aliases-service-type} service is an
16569 association list denoting how to deliver mail that comes to this
16570 system. Each entry is of the form @code{(alias addresses ...)}, with
16571 @code{alias} specifying the local alias and @code{addresses} specifying
16572 where to deliver this user's mail.
16574 The aliases aren't required to exist as users on the local system. In
16575 the above example, there doesn't need to be a @code{postmaster} entry in
16576 the @code{operating-system}'s @code{user-accounts} in order to deliver
16577 the @code{postmaster} mail to @code{bob} (which subsequently would
16578 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
16580 @subsubheading GNU Mailutils IMAP4 Daemon
16581 @cindex GNU Mailutils IMAP4 Daemon
16583 @deffn {Scheme Variable} imap4d-service-type
16584 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
16585 mailutils, GNU Mailutils Manual}), whose value should be an
16586 @code{imap4d-configuration} object as in this example:
16589 (service imap4d-service-type
16590 (imap4d-configuration
16591 (config-file (local-file "imap4d.conf"))))
16595 @deftp {Data Type} imap4d-configuration
16596 Data type representing the configuration of @command{imap4d}.
16599 @item @code{package} (default: @code{mailutils})
16600 The package that provides @command{imap4d}.
16602 @item @code{config-file} (default: @code{%default-imap4d-config-file})
16603 File-like object of the configuration file to use, by default it will listen
16604 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
16605 Mailutils Manual}, for details.
16610 @node Messaging Services
16611 @subsection Messaging Services
16616 The @code{(gnu services messaging)} module provides Guix service
16617 definitions for messaging services: currently only Prosody is supported.
16619 @subsubheading Prosody Service
16621 @deffn {Scheme Variable} prosody-service-type
16622 This is the type for the @uref{https://prosody.im, Prosody XMPP
16623 communication server}. Its value must be a @code{prosody-configuration}
16624 record as in this example:
16627 (service prosody-service-type
16628 (prosody-configuration
16629 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
16632 (int-component-configuration
16633 (hostname "conference.example.net")
16635 (mod-muc (mod-muc-configuration)))))
16638 (virtualhost-configuration
16639 (domain "example.net"))))))
16642 See below for details about @code{prosody-configuration}.
16646 By default, Prosody does not need much configuration. Only one
16647 @code{virtualhosts} field is needed: it specifies the domain you wish
16650 You can perform various sanity checks on the generated configuration
16651 with the @code{prosodyctl check} command.
16653 Prosodyctl will also help you to import certificates from the
16654 @code{letsencrypt} directory so that the @code{prosody} user can access
16655 them. See @url{https://prosody.im/doc/letsencrypt}.
16658 prosodyctl --root cert import /etc/letsencrypt/live
16661 The available configuration parameters follow. Each parameter
16662 definition is preceded by its type; for example, @samp{string-list foo}
16663 indicates that the @code{foo} parameter should be specified as a list of
16664 strings. Types starting with @code{maybe-} denote parameters that won't
16665 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
16667 There is also a way to specify the configuration as a string, if you
16668 have an old @code{prosody.cfg.lua} file that you want to port over from
16669 some other system; see the end for more details.
16671 The @code{file-object} type designates either a file-like object
16672 (@pxref{G-Expressions, file-like objects}) or a file name.
16674 @c The following documentation was initially generated by
16675 @c (generate-documentation) in (gnu services messaging). Manually maintained
16676 @c documentation is better, so we shouldn't hesitate to edit below as
16677 @c needed. However if the change you want to make to this documentation
16678 @c can be done in an automated way, it's probably easier to change
16679 @c (generate-documentation) than to make it below and have to deal with
16680 @c the churn as Prosody updates.
16682 Available @code{prosody-configuration} fields are:
16684 @deftypevr {@code{prosody-configuration} parameter} package prosody
16685 The Prosody package.
16688 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
16689 Location of the Prosody data storage directory. See
16690 @url{https://prosody.im/doc/configure}.
16691 Defaults to @samp{"/var/lib/prosody"}.
16694 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
16695 Additional plugin directories. They are searched in all the specified
16696 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
16697 Defaults to @samp{()}.
16700 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
16701 Every virtual host and component needs a certificate so that clients and
16702 servers can securely verify its identity. Prosody will automatically load
16703 certificates/keys from the directory specified here.
16704 Defaults to @samp{"/etc/prosody/certs"}.
16707 @deftypevr {@code{prosody-configuration} parameter} string-list admins
16708 This is a list of accounts that are admins for the server. Note that you
16709 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
16710 @url{https://prosody.im/doc/creating_accounts}.
16711 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
16712 Defaults to @samp{()}.
16715 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
16716 Enable use of libevent for better performance under high load. See
16717 @url{https://prosody.im/doc/libevent}.
16718 Defaults to @samp{#f}.
16721 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
16722 This is the list of modules Prosody will load on startup. It looks for
16723 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
16724 Documentation on modules can be found at:
16725 @url{https://prosody.im/doc/modules}.
16726 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
16729 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
16730 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
16731 should you want to disable them then add them to this list.
16732 Defaults to @samp{()}.
16735 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
16736 Path to a text file where the shared groups are defined. If this path is
16737 empty then @samp{mod_groups} does nothing. See
16738 @url{https://prosody.im/doc/modules/mod_groups}.
16739 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
16742 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
16743 Disable account creation by default, for security. See
16744 @url{https://prosody.im/doc/creating_accounts}.
16745 Defaults to @samp{#f}.
16748 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
16749 These are the SSL/TLS-related settings. Most of them are disabled so to
16750 use Prosody's defaults. If you do not completely understand these options, do
16751 not add them to your config, it is easy to lower the security of your server
16752 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
16754 Available @code{ssl-configuration} fields are:
16756 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
16757 This determines what handshake to use.
16760 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
16761 Path to your private key file.
16764 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
16765 Path to your certificate file.
16768 @deftypevr {@code{ssl-configuration} parameter} file-object capath
16769 Path to directory containing root certificates that you wish Prosody to
16770 trust when verifying the certificates of remote servers.
16771 Defaults to @samp{"/etc/ssl/certs"}.
16774 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
16775 Path to a file containing root certificates that you wish Prosody to trust.
16776 Similar to @code{capath} but with all certificates concatenated together.
16779 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
16780 A list of verification options (these mostly map to OpenSSL's
16781 @code{set_verify()} flags).
16784 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
16785 A list of general options relating to SSL/TLS. These map to OpenSSL's
16786 @code{set_options()}. For a full list of options available in LuaSec, see the
16790 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
16791 How long a chain of certificate authorities to check when looking for a
16792 trusted root certificate.
16795 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
16796 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
16797 clients, and in what order.
16800 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
16801 A path to a file containing parameters for Diffie-Hellman key exchange. You
16802 can create such a file with:
16803 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
16806 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
16807 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
16808 @samp{"secp384r1"}.
16811 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
16812 A list of "extra" verification options.
16815 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
16816 Password for encrypted private keys.
16821 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
16822 Whether to force all client-to-server connections to be encrypted or not.
16823 See @url{https://prosody.im/doc/modules/mod_tls}.
16824 Defaults to @samp{#f}.
16827 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
16828 Set of mechanisms that will never be offered. See
16829 @url{https://prosody.im/doc/modules/mod_saslauth}.
16830 Defaults to @samp{("DIGEST-MD5")}.
16833 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
16834 Whether to force all server-to-server connections to be encrypted or not.
16835 See @url{https://prosody.im/doc/modules/mod_tls}.
16836 Defaults to @samp{#f}.
16839 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
16840 Whether to require encryption and certificate authentication. This
16841 provides ideal security, but requires servers you communicate with to support
16842 encryption AND present valid, trusted certificates. See
16843 @url{https://prosody.im/doc/s2s#security}.
16844 Defaults to @samp{#f}.
16847 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
16848 Many servers don't support encryption or have invalid or self-signed
16849 certificates. You can list domains here that will not be required to
16850 authenticate using certificates. They will be authenticated using DNS. See
16851 @url{https://prosody.im/doc/s2s#security}.
16852 Defaults to @samp{()}.
16855 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
16856 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
16857 valid certificates for some domains by specifying a list here. See
16858 @url{https://prosody.im/doc/s2s#security}.
16859 Defaults to @samp{()}.
16862 @deftypevr {@code{prosody-configuration} parameter} string authentication
16863 Select the authentication backend to use. The default provider stores
16864 passwords in plaintext and uses Prosody's configured data storage to store the
16865 authentication data. If you do not trust your server please see
16866 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
16867 about using the hashed backend. See also
16868 @url{https://prosody.im/doc/authentication}
16869 Defaults to @samp{"internal_plain"}.
16872 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
16873 Set logging options. Advanced logging configuration is not yet supported
16874 by the Prosody service. See @url{https://prosody.im/doc/logging}.
16875 Defaults to @samp{"*syslog"}.
16878 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
16879 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
16880 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
16883 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
16884 Maximum allowed size of the HTTP body (in bytes).
16887 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
16888 Some modules expose their own URL in various ways. This URL is built
16889 from the protocol, host and port used. If Prosody sits behind a proxy, the
16890 public URL will be @code{http-external-url} instead. See
16891 @url{https://prosody.im/doc/http#external_url}.
16894 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
16895 A host in Prosody is a domain on which user accounts can be created. For
16896 example if you want your users to have addresses like
16897 @samp{"john.smith@@example.com"} then you need to add a host
16898 @samp{"example.com"}. All options in this list will apply only to this host.
16900 Note: the name "virtual" host is used in configuration to avoid confusion with
16901 the actual physical host that Prosody is installed on. A single Prosody
16902 instance can serve many domains, each one defined as a VirtualHost entry in
16903 Prosody's configuration. Conversely a server that hosts a single domain would
16904 have just one VirtualHost entry.
16906 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
16908 Available @code{virtualhost-configuration} fields are:
16910 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:
16911 @deftypevr {@code{virtualhost-configuration} parameter} string domain
16912 Domain you wish Prosody to serve.
16917 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
16918 Components are extra services on a server which are available to clients,
16919 usually on a subdomain of the main server (such as
16920 @samp{"mycomponent.example.com"}). Example components might be chatroom
16921 servers, user directories, or gateways to other protocols.
16923 Internal components are implemented with Prosody-specific plugins. To add an
16924 internal component, you simply fill the hostname field, and the plugin you wish
16925 to use for the component.
16927 See @url{https://prosody.im/doc/components}.
16928 Defaults to @samp{()}.
16930 Available @code{int-component-configuration} fields are:
16932 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:
16933 @deftypevr {@code{int-component-configuration} parameter} string hostname
16934 Hostname of the component.
16937 @deftypevr {@code{int-component-configuration} parameter} string plugin
16938 Plugin you wish to use for the component.
16941 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
16942 Multi-user chat (MUC) is Prosody's module for allowing you to create
16943 hosted chatrooms/conferences for XMPP users.
16945 General information on setting up and using multi-user chatrooms can be found
16946 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
16947 which you should read if you are new to XMPP chatrooms.
16949 See also @url{https://prosody.im/doc/modules/mod_muc}.
16951 Available @code{mod-muc-configuration} fields are:
16953 @deftypevr {@code{mod-muc-configuration} parameter} string name
16954 The name to return in service discovery responses.
16955 Defaults to @samp{"Prosody Chatrooms"}.
16958 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
16959 If @samp{#t}, this will only allow admins to create new chatrooms.
16960 Otherwise anyone can create a room. The value @samp{"local"} restricts room
16961 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
16962 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
16963 restricts to service administrators only.
16964 Defaults to @samp{#f}.
16967 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
16968 Maximum number of history messages that will be sent to the member that has
16969 just joined the room.
16970 Defaults to @samp{20}.
16977 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
16978 External components use XEP-0114, which most standalone components
16979 support. To add an external component, you simply fill the hostname field. See
16980 @url{https://prosody.im/doc/components}.
16981 Defaults to @samp{()}.
16983 Available @code{ext-component-configuration} fields are:
16985 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:
16986 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
16987 Password which the component will use to log in.
16990 @deftypevr {@code{ext-component-configuration} parameter} string hostname
16991 Hostname of the component.
16996 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
16997 Port(s) Prosody listens on for component connections.
16998 Defaults to @samp{(5347)}.
17001 @deftypevr {@code{prosody-configuration} parameter} string component-interface
17002 Interface Prosody listens on for component connections.
17003 Defaults to @samp{"127.0.0.1"}.
17006 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
17007 Raw content that will be added to the configuration file.
17010 It could be that you just want to get a @code{prosody.cfg.lua}
17011 up and running. In that case, you can pass an
17012 @code{opaque-prosody-configuration} record as the value of
17013 @code{prosody-service-type}. As its name indicates, an opaque configuration
17014 does not have easy reflective capabilities.
17015 Available @code{opaque-prosody-configuration} fields are:
17017 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
17018 The prosody package.
17021 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
17022 The contents of the @code{prosody.cfg.lua} to use.
17025 For example, if your @code{prosody.cfg.lua} is just the empty
17026 string, you could instantiate a prosody service like this:
17029 (service prosody-service-type
17030 (opaque-prosody-configuration
17031 (prosody.cfg.lua "")))
17034 @c end of Prosody auto-generated documentation
17036 @subsubheading BitlBee Service
17038 @cindex IRC (Internet Relay Chat)
17039 @cindex IRC gateway
17040 @url{http://bitlbee.org,BitlBee} is a gateway that provides an IRC
17041 interface to a variety of messaging protocols such as XMPP.
17043 @defvr {Scheme Variable} bitlbee-service-type
17044 This is the service type for the @url{http://bitlbee.org,BitlBee} IRC
17045 gateway daemon. Its value is a @code{bitlbee-configuration} (see
17048 To have BitlBee listen on port 6667 on localhost, add this line to your
17052 (service bitlbee-service-type)
17056 @deftp {Data Type} bitlbee-configuration
17057 This is the configuration for BitlBee, with the following fields:
17060 @item @code{interface} (default: @code{"127.0.0.1"})
17061 @itemx @code{port} (default: @code{6667})
17062 Listen on the network interface corresponding to the IP address
17063 specified in @var{interface}, on @var{port}.
17065 When @var{interface} is @code{127.0.0.1}, only local clients can
17066 connect; when it is @code{0.0.0.0}, connections can come from any
17067 networking interface.
17069 @item @code{package} (default: @code{bitlbee})
17070 The BitlBee package to use.
17072 @item @code{plugins} (default: @code{'()})
17073 List of plugin packages to use---e.g., @code{bitlbee-discord}.
17075 @item @code{extra-settings} (default: @code{""})
17076 Configuration snippet added as-is to the BitlBee configuration file.
17080 @subsubheading Quassel Service
17082 @cindex IRC (Internet Relay Chat)
17083 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
17084 meaning that one or more clients can attach to and detach from the
17087 @defvr {Scheme Variable} quassel-service-type
17088 This is the service type for the @url{https://quassel-irc.org/,Quassel}
17089 IRC backend daemon. Its value is a @code{quassel-configuration}
17093 @deftp {Data Type} quassel-configuration
17094 This is the configuration for Quassel, with the following fields:
17097 @item @code{quassel} (default: @code{quassel})
17098 The Quassel package to use.
17100 @item @code{interface} (default: @code{"::,0.0.0.0"})
17101 @item @code{port} (default: @code{4242})
17102 Listen on the network interface(s) corresponding to the IPv4 or IPv6
17103 interfaces specified in the comma delimited @var{interface}, on
17106 @item @code{loglevel} (default: @code{"Info"})
17107 The level of logging desired. Accepted values are Debug, Info, Warning
17112 @node Telephony Services
17113 @subsection Telephony Services
17115 @cindex Murmur (VoIP server)
17116 @cindex VoIP server
17117 This section describes how to set up and run a Murmur server. Murmur is
17118 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
17121 @deftp {Data Type} murmur-configuration
17122 The service type for the Murmur server. An example configuration can
17126 (service murmur-service-type
17127 (murmur-configuration
17129 "Welcome to this Mumble server running on Guix!")
17130 (cert-required? #t) ;disallow text password logins
17131 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
17132 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
17135 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
17136 password with the command that is printed during the activation phase.
17138 It is recommended to register a normal Mumble user account
17139 and grant it admin or moderator rights.
17140 You can use the @code{mumble} client to
17141 login as new normal user, register yourself, and log out.
17142 For the next step login with the name @code{SuperUser} use
17143 the @code{SuperUser} password that you set previously,
17144 and grant your newly registered mumble user administrator or moderator
17145 rights and create some channels.
17147 Available @code{murmur-configuration} fields are:
17150 @item @code{package} (default: @code{mumble})
17151 Package that contains @code{bin/murmurd}.
17153 @item @code{user} (default: @code{"murmur"})
17154 User who will run the Murmur server.
17156 @item @code{group} (default: @code{"murmur"})
17157 Group of the user who will run the murmur server.
17159 @item @code{port} (default: @code{64738})
17160 Port on which the server will listen.
17162 @item @code{welcome-text} (default: @code{""})
17163 Welcome text sent to clients when they connect.
17165 @item @code{server-password} (default: @code{""})
17166 Password the clients have to enter in order to connect.
17168 @item @code{max-users} (default: @code{100})
17169 Maximum of users that can be connected to the server at once.
17171 @item @code{max-user-bandwidth} (default: @code{#f})
17172 Maximum voice traffic a user can send per second.
17174 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
17175 File name of the sqlite database.
17176 The service's user will become the owner of the directory.
17178 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
17179 File name of the log file.
17180 The service's user will become the owner of the directory.
17182 @item @code{autoban-attempts} (default: @code{10})
17183 Maximum number of logins a user can make in @code{autoban-timeframe}
17184 without getting auto banned for @code{autoban-time}.
17186 @item @code{autoban-timeframe} (default: @code{120})
17187 Timeframe for autoban in seconds.
17189 @item @code{autoban-time} (default: @code{300})
17190 Amount of time in seconds for which a client gets banned
17191 when violating the autoban limits.
17193 @item @code{opus-threshold} (default: @code{100})
17194 Percentage of clients that need to support opus
17195 before switching over to opus audio codec.
17197 @item @code{channel-nesting-limit} (default: @code{10})
17198 How deep channels can be nested at maximum.
17200 @item @code{channelname-regex} (default: @code{#f})
17201 A string in form of a Qt regular expression that channel names must conform to.
17203 @item @code{username-regex} (default: @code{#f})
17204 A string in form of a Qt regular expression that user names must conform to.
17206 @item @code{text-message-length} (default: @code{5000})
17207 Maximum size in bytes that a user can send in one text chat message.
17209 @item @code{image-message-length} (default: @code{(* 128 1024)})
17210 Maximum size in bytes that a user can send in one image message.
17212 @item @code{cert-required?} (default: @code{#f})
17213 If it is set to @code{#t} clients that use weak password authentification
17214 will not be accepted. Users must have completed the certificate wizard to join.
17216 @item @code{remember-channel?} (default: @code{#f})
17217 Should murmur remember the last channel each user was in when they disconnected
17218 and put them into the remembered channel when they rejoin.
17220 @item @code{allow-html?} (default: @code{#f})
17221 Should html be allowed in text messages, user comments, and channel descriptions.
17223 @item @code{allow-ping?} (default: @code{#f})
17224 Setting to true exposes the current user count, the maximum user count, and
17225 the server's maximum bandwidth per client to unauthenticated users. In the
17226 Mumble client, this information is shown in the Connect dialog.
17228 Disabling this setting will prevent public listing of the server.
17230 @item @code{bonjour?} (default: @code{#f})
17231 Should the server advertise itself in the local network through the bonjour protocol.
17233 @item @code{send-version?} (default: @code{#f})
17234 Should the murmur server version be exposed in ping requests.
17236 @item @code{log-days} (default: @code{31})
17237 Murmur also stores logs in the database, which are accessible via RPC.
17238 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
17239 or -1 to disable logging to the database.
17241 @item @code{obfuscate-ips?} (default: @code{#t})
17242 Should logged ips be obfuscated to protect the privacy of users.
17244 @item @code{ssl-cert} (default: @code{#f})
17245 File name of the SSL/TLS certificate used for encrypted connections.
17248 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
17250 @item @code{ssl-key} (default: @code{#f})
17251 Filepath to the ssl private key used for encrypted connections.
17253 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
17256 @item @code{ssl-dh-params} (default: @code{#f})
17257 File name of a PEM-encoded file with Diffie-Hellman parameters
17258 for the SSL/TLS encryption. Alternatively you set it to
17259 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
17260 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
17262 @item @code{ssl-ciphers} (default: @code{#f})
17263 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
17266 This option is specified using
17267 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
17268 OpenSSL cipher list notation}.
17270 It is recommended that you try your cipher string using 'openssl ciphers <string>'
17271 before setting it here, to get a feel for which cipher suites you will get.
17272 After setting this option, it is recommend that you inspect your Murmur log
17273 to ensure that Murmur is using the cipher suites that you expected it to.
17275 Note: Changing this option may impact the backwards compatibility of your
17276 Murmur server, and can remove the ability for older Mumble clients to be able
17279 @item @code{public-registration} (default: @code{#f})
17280 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
17282 You can optionally register your server in the public server list that the
17283 @code{mumble} client shows on startup.
17284 You cannot register your server if you have set a @code{server-password},
17285 or set @code{allow-ping} to @code{#f}.
17287 It might take a few hours until it shows up in the public list.
17289 @item @code{file} (default: @code{#f})
17290 Optional alternative override for this configuration.
17294 @deftp {Data Type} murmur-public-registration-configuration
17295 Configuration for public registration of a murmur service.
17299 This is a display name for your server. Not to be confused with the hostname.
17301 @item @code{password}
17302 A password to identify your registration.
17303 Subsequent updates will need the same password. Don't lose your password.
17306 This should be a @code{http://} or @code{https://} link to your web
17309 @item @code{hostname} (default: @code{#f})
17310 By default your server will be listed by its IP address.
17311 If it is set your server will be linked by this host name instead.
17317 @node Monitoring Services
17318 @subsection Monitoring Services
17320 @subsubheading Tailon Service
17322 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
17323 viewing and searching log files.
17325 The following example will configure the service with default values.
17326 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
17329 (service tailon-service-type)
17332 The following example customises more of the Tailon configuration,
17333 adding @command{sed} to the list of allowed commands.
17336 (service tailon-service-type
17337 (tailon-configuration
17339 (tailon-configuration-file
17340 (allowed-commands '("tail" "grep" "awk" "sed"))))))
17344 @deftp {Data Type} tailon-configuration
17345 Data type representing the configuration of Tailon.
17346 This type has the following parameters:
17349 @item @code{config-file} (default: @code{(tailon-configuration-file)})
17350 The configuration file to use for Tailon. This can be set to a
17351 @dfn{tailon-configuration-file} record value, or any gexp
17352 (@pxref{G-Expressions}).
17354 For example, to instead use a local file, the @code{local-file} function
17358 (service tailon-service-type
17359 (tailon-configuration
17360 (config-file (local-file "./my-tailon.conf"))))
17363 @item @code{package} (default: @code{tailon})
17364 The tailon package to use.
17369 @deftp {Data Type} tailon-configuration-file
17370 Data type representing the configuration options for Tailon.
17371 This type has the following parameters:
17374 @item @code{files} (default: @code{(list "/var/log")})
17375 List of files to display. The list can include strings for a single file
17376 or directory, or a list, where the first item is the name of a
17377 subsection, and the remaining items are the files or directories in that
17380 @item @code{bind} (default: @code{"localhost:8080"})
17381 Address and port to which Tailon should bind on.
17383 @item @code{relative-root} (default: @code{#f})
17384 URL path to use for Tailon, set to @code{#f} to not use a path.
17386 @item @code{allow-transfers?} (default: @code{#t})
17387 Allow downloading the log files in the web interface.
17389 @item @code{follow-names?} (default: @code{#t})
17390 Allow tailing of not-yet existent files.
17392 @item @code{tail-lines} (default: @code{200})
17393 Number of lines to read initially from each file.
17395 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
17396 Commands to allow running. By default, @code{sed} is disabled.
17398 @item @code{debug?} (default: @code{#f})
17399 Set @code{debug?} to @code{#t} to show debug messages.
17401 @item @code{wrap-lines} (default: @code{#t})
17402 Initial line wrapping state in the web interface. Set to @code{#t} to
17403 initially wrap lines (the default), or to @code{#f} to initially not
17406 @item @code{http-auth} (default: @code{#f})
17407 HTTP authentication type to use. Set to @code{#f} to disable
17408 authentication (the default). Supported values are @code{"digest"} or
17411 @item @code{users} (default: @code{#f})
17412 If HTTP authentication is enabled (see @code{http-auth}), access will be
17413 restricted to the credentials provided here. To configure users, use a
17414 list of pairs, where the first element of the pair is the username, and
17415 the 2nd element of the pair is the password.
17418 (tailon-configuration-file
17419 (http-auth "basic")
17420 (users '(("user1" . "password1")
17421 ("user2" . "password2"))))
17428 @subsubheading Darkstat Service
17430 Darkstat is a packet sniffer that captures network traffic, calculates
17431 statistics about usage, and serves reports over HTTP.
17433 @defvar {Scheme Variable} darkstat-service-type
17434 This is the service type for the
17435 @uref{https://unix4lyfe.org/darkstat/, darkstat}
17436 service, its value must be a @code{darkstat-configuration} record as in
17440 (service darkstat-service-type
17441 (darkstat-configuration
17442 (interface "eno1")))
17446 @deftp {Data Type} darkstat-configuration
17447 Data type representing the configuration of @command{darkstat}.
17450 @item @code{package} (default: @code{darkstat})
17451 The darkstat package to use.
17453 @item @code{interface}
17454 Capture traffic on the specified network interface.
17456 @item @code{port} (default: @code{"667"})
17457 Bind the web interface to the specified port.
17459 @item @code{bind-address} (default: @code{"127.0.0.1"})
17460 Bind the web interface to the specified address.
17462 @item @code{base} (default: @code{"/"})
17463 Specify the path of the base URL. This can be useful if
17464 @command{darkstat} is accessed via a reverse proxy.
17469 @subsubheading Prometheus Node Exporter Service
17471 @cindex prometheus-node-exporter
17472 The Prometheus ``node exporter'' makes hardware and operating system statistics
17473 provided by the Linux kernel available for the Prometheus monitoring system.
17474 This service should be deployed on all physical nodes and virtual machines,
17475 where monitoring these statistics is desirable.
17477 @defvar {Scheme variable} prometheus-node-exporter-service-type
17478 This is the service type for the
17479 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
17480 service, its value must be a @code{prometheus-node-exporter-configuration}
17481 record as in this example:
17484 (service prometheus-node-exporter-service-type
17485 (prometheus-node-exporter-configuration
17486 (web-listen-address ":9100")))
17490 @deftp {Data Type} prometheus-node-exporter-configuration
17491 Data type representing the configuration of @command{node_exporter}.
17494 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
17495 The prometheus-node-exporter package to use.
17497 @item @code{web-listen-address} (default: @code{":9100"})
17498 Bind the web interface to the specified address.
17503 @subsubheading Zabbix server
17504 @cindex zabbix zabbix-server
17505 Zabbix provides monitoring metrics, among others network utilization, CPU load
17506 and disk space consumption:
17509 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
17510 @item Auto-discovery of servers and network devices and interfaces.
17511 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
17512 @item Distributed monitoring with centralized web administration.
17513 @item Native high performance agents.
17514 @item SLA, and ITIL KPI metrics on reporting.
17515 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
17516 @item Remote command execution through Zabbix proxies.
17519 @c %start of fragment
17521 Available @code{zabbix-server-configuration} fields are:
17523 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
17524 The zabbix-server package.
17528 @deftypevr {@code{zabbix-server-configuration} parameter} string user
17529 User who will run the Zabbix server.
17531 Defaults to @samp{"zabbix"}.
17535 @deftypevr {@code{zabbix-server-configuration} parameter} group group
17536 Group who will run the Zabbix server.
17538 Defaults to @samp{"zabbix"}.
17542 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
17543 Database host name.
17545 Defaults to @samp{"127.0.0.1"}.
17549 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
17552 Defaults to @samp{"zabbix"}.
17556 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
17559 Defaults to @samp{"zabbix"}.
17563 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
17564 Database password. Please, use @code{include-files} with
17565 @code{DBPassword=SECRET} inside a specified file instead.
17567 Defaults to @samp{""}.
17571 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
17574 Defaults to @samp{5432}.
17578 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
17579 Specifies where log messages are written to:
17583 @code{system} - syslog.
17586 @code{file} - file specified with @code{log-file} parameter.
17589 @code{console} - standard output.
17593 Defaults to @samp{""}.
17597 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
17598 Log file name for @code{log-type} @code{file} parameter.
17600 Defaults to @samp{"/var/log/zabbix/server.log"}.
17604 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
17607 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
17611 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
17612 The location of certificate authority (CA) files for SSL server
17613 certificate verification.
17615 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
17619 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
17620 Location of SSL client certificates.
17622 Defaults to @samp{"/etc/ssl/certs"}.
17626 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
17627 Extra options will be appended to Zabbix server configuration file.
17629 Defaults to @samp{""}.
17633 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
17634 You may include individual files or all files in a directory in the
17635 configuration file.
17637 Defaults to @samp{()}.
17641 @c %end of fragment
17643 @subsubheading Zabbix agent
17644 @cindex zabbix zabbix-agent
17646 Zabbix agent gathers information for Zabbix server.
17648 @c %start of fragment
17650 Available @code{zabbix-agent-configuration} fields are:
17652 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
17653 The zabbix-agent package.
17657 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
17658 User who will run the Zabbix agent.
17660 Defaults to @samp{"zabbix"}.
17664 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
17665 Group who will run the Zabbix agent.
17667 Defaults to @samp{"zabbix"}.
17671 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
17672 Unique, case sensitive hostname which is required for active checks and
17673 must match hostname as configured on the server.
17675 Defaults to @samp{"Zabbix server"}.
17679 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
17680 Specifies where log messages are written to:
17684 @code{system} - syslog.
17687 @code{file} - file specified with @code{log-file} parameter.
17690 @code{console} - standard output.
17694 Defaults to @samp{""}.
17698 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
17699 Log file name for @code{log-type} @code{file} parameter.
17701 Defaults to @samp{"/var/log/zabbix/agent.log"}.
17705 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
17708 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
17712 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
17713 List of IP addresses, optionally in CIDR notation, or hostnames of
17714 Zabbix servers and Zabbix proxies. Incoming connections will be
17715 accepted only from the hosts listed here.
17717 Defaults to @samp{("127.0.0.1")}.
17721 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
17722 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
17723 proxies for active checks. If port is not specified, default port is
17724 used. If this parameter is not specified, active checks are disabled.
17726 Defaults to @samp{("127.0.0.1")}.
17730 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
17731 Extra options will be appended to Zabbix server configuration file.
17733 Defaults to @samp{""}.
17737 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
17738 You may include individual files or all files in a directory in the
17739 configuration file.
17741 Defaults to @samp{()}.
17745 @c %end of fragment
17747 @subsubheading Zabbix front-end
17748 @cindex zabbix zabbix-front-end
17750 This service provides a WEB interface to Zabbix server.
17752 @c %start of fragment
17754 Available @code{zabbix-front-end-configuration} fields are:
17756 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
17757 NGINX configuration.
17761 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
17762 Database host name.
17764 Defaults to @samp{"localhost"}.
17768 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
17771 Defaults to @samp{5432}.
17775 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
17778 Defaults to @samp{"zabbix"}.
17782 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
17785 Defaults to @samp{"zabbix"}.
17789 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
17790 Database password. Please, use @code{db-secret-file} instead.
17792 Defaults to @samp{""}.
17796 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
17797 Secret file which will be appended to @file{zabbix.conf.php} file. This
17798 file contains credentials for use by Zabbix front-end. You are expected
17799 to create it manually.
17801 Defaults to @samp{""}.
17805 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
17806 Zabbix server hostname.
17808 Defaults to @samp{"localhost"}.
17812 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
17813 Zabbix server port.
17815 Defaults to @samp{10051}.
17820 @c %end of fragment
17822 @node Kerberos Services
17823 @subsection Kerberos Services
17826 The @code{(gnu services kerberos)} module provides services relating to
17827 the authentication protocol @dfn{Kerberos}.
17829 @subsubheading Krb5 Service
17831 Programs using a Kerberos client library normally
17832 expect a configuration file in @file{/etc/krb5.conf}.
17833 This service generates such a file from a definition provided in the
17834 operating system declaration.
17835 It does not cause any daemon to be started.
17837 No ``keytab'' files are provided by this service---you must explicitly create them.
17838 This service is known to work with the MIT client library, @code{mit-krb5}.
17839 Other implementations have not been tested.
17841 @defvr {Scheme Variable} krb5-service-type
17842 A service type for Kerberos 5 clients.
17846 Here is an example of its use:
17848 (service krb5-service-type
17849 (krb5-configuration
17850 (default-realm "EXAMPLE.COM")
17851 (allow-weak-crypto? #t)
17854 (name "EXAMPLE.COM")
17855 (admin-server "groucho.example.com")
17856 (kdc "karl.example.com"))
17859 (admin-server "kerb-admin.argrx.edu")
17860 (kdc "keys.argrx.edu"))))))
17864 This example provides a Kerberos@tie{}5 client configuration which:
17866 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
17867 of which have distinct administration servers and key distribution centers;
17868 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
17869 specified by clients;
17870 @item Accepts services which only support encryption types known to be weak.
17873 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
17874 Only the most commonly used ones are described here.
17875 For a full list, and more detailed explanation of each, see the MIT
17876 @uref{http://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
17880 @deftp {Data Type} krb5-realm
17881 @cindex realm, kerberos
17884 This field is a string identifying the name of the realm.
17885 A common convention is to use the fully qualified DNS name of your organization,
17886 converted to upper case.
17888 @item @code{admin-server}
17889 This field is a string identifying the host where the administration server is
17893 This field is a string identifying the key distribution center
17898 @deftp {Data Type} krb5-configuration
17901 @item @code{allow-weak-crypto?} (default: @code{#f})
17902 If this flag is @code{#t} then services which only offer encryption algorithms
17903 known to be weak will be accepted.
17905 @item @code{default-realm} (default: @code{#f})
17906 This field should be a string identifying the default Kerberos
17907 realm for the client.
17908 You should set this field to the name of your Kerberos realm.
17909 If this value is @code{#f}
17910 then a realm must be specified with every Kerberos principal when invoking programs
17911 such as @command{kinit}.
17913 @item @code{realms}
17914 This should be a non-empty list of @code{krb5-realm} objects, which clients may
17916 Normally, one of them will have a @code{name} field matching the @code{default-realm}
17922 @subsubheading PAM krb5 Service
17925 The @code{pam-krb5} service allows for login authentication and password
17926 management via Kerberos.
17927 You will need this service if you want PAM enabled applications to authenticate
17928 users using Kerberos.
17930 @defvr {Scheme Variable} pam-krb5-service-type
17931 A service type for the Kerberos 5 PAM module.
17934 @deftp {Data Type} pam-krb5-configuration
17935 Data type representing the configuration of the Kerberos 5 PAM module
17936 This type has the following parameters:
17938 @item @code{pam-krb5} (default: @code{pam-krb5})
17939 The pam-krb5 package to use.
17941 @item @code{minimum-uid} (default: @code{1000})
17942 The smallest user ID for which Kerberos authentications should be attempted.
17943 Local accounts with lower values will silently fail to authenticate.
17948 @node LDAP Services
17949 @subsection LDAP Services
17951 @cindex nslcd, LDAP service
17953 The @code{(gnu services authentication)} module provides the
17954 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
17955 server. In addition to configuring the service itself, you may want to add
17956 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
17957 Switch} for detailed information.
17959 Here is a simple operating system declaration with a default configuration of
17960 the @code{nslcd-service-type} and a Name Service Switch configuration that
17961 consults the @code{ldap} name service last:
17964 (use-service-modules authentication)
17965 (use-modules (gnu system nss))
17971 (service nslcd-service-type)
17972 (service dhcp-client-service-type)
17974 (name-service-switch
17975 (let ((services (list (name-service (name "db"))
17976 (name-service (name "files"))
17977 (name-service (name "ldap")))))
17978 (name-service-switch
17979 (inherit %mdns-host-lookup-nss)
17980 (password services)
17983 (netgroup services)
17984 (gshadow services)))))
17987 @c %start of generated documentation for nslcd-configuration
17989 Available @code{nslcd-configuration} fields are:
17991 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
17992 The @code{nss-pam-ldapd} package to use.
17996 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
17997 The number of threads to start that can handle requests and perform LDAP
17998 queries. Each thread opens a separate connection to the LDAP server.
17999 The default is to start 5 threads.
18001 Defaults to @samp{disabled}.
18005 @deftypevr {@code{nslcd-configuration} parameter} string uid
18006 This specifies the user id with which the daemon should be run.
18008 Defaults to @samp{"nslcd"}.
18012 @deftypevr {@code{nslcd-configuration} parameter} string gid
18013 This specifies the group id with which the daemon should be run.
18015 Defaults to @samp{"nslcd"}.
18019 @deftypevr {@code{nslcd-configuration} parameter} log-option log
18020 This option controls the way logging is done via a list containing
18021 SCHEME and LEVEL. The SCHEME argument may either be the symbols "none"
18022 or "syslog", or an absolute file name. The LEVEL argument is optional
18023 and specifies the log level. The log level may be one of the following
18024 symbols: "crit", "error", "warning", "notice", "info" or "debug". All
18025 messages with the specified log level or higher are logged.
18027 Defaults to @samp{("/var/log/nslcd" info)}.
18031 @deftypevr {@code{nslcd-configuration} parameter} list uri
18032 The list of LDAP server URIs. Normally, only the first server will be
18033 used with the following servers as fall-back.
18035 Defaults to @samp{("ldap://localhost:389/")}.
18039 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
18040 The version of the LDAP protocol to use. The default is to use the
18041 maximum version supported by the LDAP library.
18043 Defaults to @samp{disabled}.
18047 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
18048 Specifies the distinguished name with which to bind to the directory
18049 server for lookups. The default is to bind anonymously.
18051 Defaults to @samp{disabled}.
18055 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
18056 Specifies the credentials with which to bind. This option is only
18057 applicable when used with binddn.
18059 Defaults to @samp{disabled}.
18063 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
18064 Specifies the distinguished name to use when the root user tries to
18065 modify a user's password using the PAM module.
18067 Defaults to @samp{disabled}.
18071 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
18072 Specifies the credentials with which to bind if the root user tries to
18073 change a user's password. This option is only applicable when used with
18076 Defaults to @samp{disabled}.
18080 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
18081 Specifies the SASL mechanism to be used when performing SASL
18084 Defaults to @samp{disabled}.
18088 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
18089 Specifies the SASL realm to be used when performing SASL authentication.
18091 Defaults to @samp{disabled}.
18095 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
18096 Specifies the authentication identity to be used when performing SASL
18099 Defaults to @samp{disabled}.
18103 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
18104 Specifies the authorization identity to be used when performing SASL
18107 Defaults to @samp{disabled}.
18111 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
18112 Determines whether the LDAP server host name should be canonicalised. If
18113 this is enabled the LDAP library will do a reverse host name lookup. By
18114 default, it is left up to the LDAP library whether this check is
18117 Defaults to @samp{disabled}.
18121 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
18122 Set the name for the GSS-API Kerberos credentials cache.
18124 Defaults to @samp{disabled}.
18128 @deftypevr {@code{nslcd-configuration} parameter} string base
18129 The directory search base.
18131 Defaults to @samp{"dc=example,dc=com"}.
18135 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
18136 Specifies the search scope (subtree, onelevel, base or children). The
18137 default scope is subtree; base scope is almost never useful for name
18138 service lookups; children scope is not supported on all servers.
18140 Defaults to @samp{(subtree)}.
18144 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
18145 Specifies the policy for dereferencing aliases. The default policy is
18146 to never dereference aliases.
18148 Defaults to @samp{disabled}.
18152 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
18153 Specifies whether automatic referral chasing should be enabled. The
18154 default behaviour is to chase referrals.
18156 Defaults to @samp{disabled}.
18160 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
18161 This option allows for custom attributes to be looked up instead of the
18162 default RFC 2307 attributes. It is a list of maps, each consisting of
18163 the name of a map, the RFC 2307 attribute to match and the query
18164 expression for the attribute as it is available in the directory.
18166 Defaults to @samp{()}.
18170 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
18171 A list of filters consisting of the name of a map to which the filter
18172 applies and an LDAP search filter expression.
18174 Defaults to @samp{()}.
18178 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
18179 Specifies the time limit in seconds to use when connecting to the
18180 directory server. The default value is 10 seconds.
18182 Defaults to @samp{disabled}.
18186 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
18187 Specifies the time limit (in seconds) to wait for a response from the
18188 LDAP server. A value of zero, which is the default, is to wait
18189 indefinitely for searches to be completed.
18191 Defaults to @samp{disabled}.
18195 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
18196 Specifies the period if inactivity (in seconds) after which the con‐
18197 nection to the LDAP server will be closed. The default is not to time
18200 Defaults to @samp{disabled}.
18204 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
18205 Specifies the number of seconds to sleep when connecting to all LDAP
18206 servers fails. By default one second is waited between the first
18207 failure and the first retry.
18209 Defaults to @samp{disabled}.
18213 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
18214 Specifies the time after which the LDAP server is considered to be
18215 permanently unavailable. Once this time is reached retries will be done
18216 only once per this time period. The default value is 10 seconds.
18218 Defaults to @samp{disabled}.
18222 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
18223 Specifies whether to use SSL/TLS or not (the default is not to). If
18224 'start-tls is specified then StartTLS is used rather than raw LDAP over
18227 Defaults to @samp{disabled}.
18231 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
18232 Specifies what checks to perform on a server-supplied certificate. The
18233 meaning of the values is described in the ldap.conf(5) manual page.
18235 Defaults to @samp{disabled}.
18239 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
18240 Specifies the directory containing X.509 certificates for peer authen‐
18241 tication. This parameter is ignored when using GnuTLS.
18243 Defaults to @samp{disabled}.
18247 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
18248 Specifies the path to the X.509 certificate for peer authentication.
18250 Defaults to @samp{disabled}.
18254 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
18255 Specifies the path to an entropy source. This parameter is ignored when
18258 Defaults to @samp{disabled}.
18262 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
18263 Specifies the ciphers to use for TLS as a string.
18265 Defaults to @samp{disabled}.
18269 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
18270 Specifies the path to the file containing the local certificate for
18271 client TLS authentication.
18273 Defaults to @samp{disabled}.
18277 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
18278 Specifies the path to the file containing the private key for client TLS
18281 Defaults to @samp{disabled}.
18285 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
18286 Set this to a number greater than 0 to request paged results from the
18287 LDAP server in accordance with RFC2696. The default (0) is to not
18288 request paged results.
18290 Defaults to @samp{disabled}.
18294 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
18295 This option prevents group membership lookups through LDAP for the
18296 specified users. Alternatively, the value 'all-local may be used. With
18297 that value nslcd builds a full list of non-LDAP users on startup.
18299 Defaults to @samp{disabled}.
18303 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
18304 This option ensures that LDAP users with a numeric user id lower than
18305 the specified value are ignored.
18307 Defaults to @samp{disabled}.
18311 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
18312 This option specifies an offset that is added to all LDAP numeric user
18313 ids. This can be used to avoid user id collisions with local users.
18315 Defaults to @samp{disabled}.
18319 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
18320 This option specifies an offset that is added to all LDAP numeric group
18321 ids. This can be used to avoid user id collisions with local groups.
18323 Defaults to @samp{disabled}.
18327 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
18328 If this option is set, the member attribute of a group may point to
18329 another group. Members of nested groups are also returned in the higher
18330 level group and parent groups are returned when finding groups for a
18331 specific user. The default is not to perform extra searches for nested
18334 Defaults to @samp{disabled}.
18338 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
18339 If this option is set, the group member list is not retrieved when
18340 looking up groups. Lookups for finding which groups a user belongs to
18341 will remain functional so the user will likely still get the correct
18342 groups assigned on login.
18344 Defaults to @samp{disabled}.
18348 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
18349 If this option is set, functions which cause all user/group entries to
18350 be loaded from the directory will not succeed in doing so. This can
18351 dramatically reduce LDAP server load in situations where there are a
18352 great number of users and/or groups. This option is not recommended for
18353 most configurations.
18355 Defaults to @samp{disabled}.
18359 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
18360 This option can be used to specify how user and group names are verified
18361 within the system. This pattern is used to check all user and group
18362 names that are requested and returned from LDAP.
18364 Defaults to @samp{disabled}.
18368 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
18369 This specifies whether or not to perform searches using case-insensitive
18370 matching. Enabling this could open up the system to authorization
18371 bypass vulnerabilities and introduce nscd cache poisoning
18372 vulnerabilities which allow denial of service.
18374 Defaults to @samp{disabled}.
18378 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
18379 This option specifies whether password policy controls are requested and
18380 handled from the LDAP server when performing user authentication.
18382 Defaults to @samp{disabled}.
18386 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
18387 By default nslcd performs an LDAP search with the user's credentials
18388 after BIND (authentication) to ensure that the BIND operation was
18389 successful. The default search is a simple check to see if the user's
18390 DN exists. A search filter can be specified that will be used instead.
18391 It should return at least one entry.
18393 Defaults to @samp{disabled}.
18397 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
18398 This option allows flexible fine tuning of the authorisation check that
18399 should be performed. The search filter specified is executed and if any
18400 entries match, access is granted, otherwise access is denied.
18402 Defaults to @samp{disabled}.
18406 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
18407 If this option is set password modification using pam_ldap will be
18408 denied and the specified message will be presented to the user instead.
18409 The message can be used to direct the user to an alternative means of
18410 changing their password.
18412 Defaults to @samp{disabled}.
18416 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
18417 List of pam service names for which LDAP authentication should suffice.
18419 Defaults to @samp{()}.
18423 @c %end of generated documentation for nslcd-configuration
18427 @subsection Web Services
18432 The @code{(gnu services web)} module provides the Apache HTTP Server,
18433 the nginx web server, and also a fastcgi wrapper daemon.
18435 @subsubheading Apache HTTP Server
18437 @deffn {Scheme Variable} httpd-service-type
18438 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
18439 (@dfn{httpd}). The value for this service type is a
18440 @code{httpd-configuration} record.
18442 A simple example configuration is given below.
18445 (service httpd-service-type
18446 (httpd-configuration
18449 (server-name "www.example.com")
18450 (document-root "/srv/http/www.example.com")))))
18453 Other services can also extend the @code{httpd-service-type} to add to
18457 (simple-service 'my-extra-server httpd-service-type
18461 (list (string-append
18462 "ServerName "www.example.com
18463 DocumentRoot \"/srv/http/www.example.com\"")))))
18467 The details for the @code{httpd-configuration}, @code{httpd-module},
18468 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
18471 @deffn {Data Type} httpd-configuration
18472 This data type represents the configuration for the httpd service.
18475 @item @code{package} (default: @code{httpd})
18476 The httpd package to use.
18478 @item @code{pid-file} (default: @code{"/var/run/httpd"})
18479 The pid file used by the shepherd-service.
18481 @item @code{config} (default: @code{(httpd-config-file)})
18482 The configuration file to use with the httpd service. The default value
18483 is a @code{httpd-config-file} record, but this can also be a different
18484 G-expression that generates a file, for example a @code{plain-file}. A
18485 file outside of the store can also be specified through a string.
18490 @deffn {Data Type} httpd-module
18491 This data type represents a module for the httpd service.
18495 The name of the module.
18498 The file for the module. This can be relative to the httpd package being
18499 used, the absolute location of a file, or a G-expression for a file
18500 within the store, for example @code{(file-append mod-wsgi
18501 "/modules/mod_wsgi.so")}.
18506 @defvr {Scheme Variable} %default-httpd-modules
18507 A default list of @code{httpd-module} objects.
18510 @deffn {Data Type} httpd-config-file
18511 This data type represents a configuration file for the httpd service.
18514 @item @code{modules} (default: @code{%default-httpd-modules})
18515 The modules to load. Additional modules can be added here, or loaded by
18516 additional configuration.
18518 For example, in order to handle requests for PHP files, you can use Apache’s
18519 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
18522 (service httpd-service-type
18523 (httpd-configuration
18528 (name "proxy_module")
18529 (file "modules/mod_proxy.so"))
18531 (name "proxy_fcgi_module")
18532 (file "modules/mod_proxy_fcgi.so"))
18533 %default-httpd-modules))
18534 (extra-config (list "\
18535 <FilesMatch \\.php$>
18536 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
18537 </FilesMatch>"))))))
18538 (service php-fpm-service-type
18539 (php-fpm-configuration
18540 (socket "/var/run/php-fpm.sock")
18541 (socket-group "httpd")))
18544 @item @code{server-root} (default: @code{httpd})
18545 The @code{ServerRoot} in the configuration file, defaults to the httpd
18546 package. Directives including @code{Include} and @code{LoadModule} are
18547 taken as relative to the server root.
18549 @item @code{server-name} (default: @code{#f})
18550 The @code{ServerName} in the configuration file, used to specify the
18551 request scheme, hostname and port that the server uses to identify
18554 This doesn't need to be set in the server config, and can be specifyed
18555 in virtual hosts. The default is @code{#f} to not specify a
18558 @item @code{document-root} (default: @code{"/srv/http"})
18559 The @code{DocumentRoot} from which files will be served.
18561 @item @code{listen} (default: @code{'("80")})
18562 The list of values for the @code{Listen} directives in the config
18563 file. The value should be a list of strings, when each string can
18564 specify the port number to listen on, and optionally the IP address and
18567 @item @code{pid-file} (default: @code{"/var/run/httpd"})
18568 The @code{PidFile} to use. This should match the @code{pid-file} set in
18569 the @code{httpd-configuration} so that the Shepherd service is
18570 configured correctly.
18572 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
18573 The @code{ErrorLog} to which the server will log errors.
18575 @item @code{user} (default: @code{"httpd"})
18576 The @code{User} which the server will answer requests as.
18578 @item @code{group} (default: @code{"httpd"})
18579 The @code{Group} which the server will answer requests as.
18581 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
18582 A flat list of strings and G-expressions which will be added to the end
18583 of the configuration file.
18585 Any values which the service is extended with will be appended to this
18591 @deffn {Data Type} httpd-virtualhost
18592 This data type represents a virtualhost configuration block for the httpd service.
18594 These should be added to the extra-config for the httpd-service.
18597 (simple-service 'my-extra-server httpd-service-type
18601 (list (string-append
18602 "ServerName "www.example.com
18603 DocumentRoot \"/srv/http/www.example.com\"")))))
18607 @item @code{addresses-and-ports}
18608 The addresses and ports for the @code{VirtualHost} directive.
18610 @item @code{contents}
18611 The contents of the @code{VirtualHost} directive, this should be a list
18612 of strings and G-expressions.
18617 @subsubheading NGINX
18619 @deffn {Scheme Variable} nginx-service-type
18620 Service type for the @uref{https://nginx.org/,NGinx} web server. The
18621 value for this service type is a @code{<nginx-configuration>} record.
18623 A simple example configuration is given below.
18626 (service nginx-service-type
18627 (nginx-configuration
18629 (list (nginx-server-configuration
18630 (server-name '("www.example.com"))
18631 (root "/srv/http/www.example.com"))))))
18634 In addition to adding server blocks to the service configuration
18635 directly, this service can be extended by other services to add server
18636 blocks, as in this example:
18639 (simple-service 'my-extra-server nginx-service-type
18640 (list (nginx-server-configuration
18641 (root "/srv/http/extra-website")
18642 (try-files (list "$uri" "$uri/index.html")))))
18646 At startup, @command{nginx} has not yet read its configuration file, so
18647 it uses a default file to log error messages. If it fails to load its
18648 configuration file, that is where error messages are logged. After the
18649 configuration file is loaded, the default error log file changes as per
18650 configuration. In our case, startup error messages can be found in
18651 @file{/var/run/nginx/logs/error.log}, and after configuration in
18652 @file{/var/log/nginx/error.log}. The second location can be changed
18653 with the @var{log-directory} configuration option.
18655 @deffn {Data Type} nginx-configuration
18656 This data type represents the configuration for NGinx. Some
18657 configuration can be done through this and the other provided record
18658 types, or alternatively, a config file can be provided.
18661 @item @code{nginx} (default: @code{nginx})
18662 The nginx package to use.
18664 @item @code{log-directory} (default: @code{"/var/log/nginx"})
18665 The directory to which NGinx will write log files.
18667 @item @code{run-directory} (default: @code{"/var/run/nginx"})
18668 The directory in which NGinx will create a pid file, and write temporary
18671 @item @code{server-blocks} (default: @code{'()})
18672 A list of @dfn{server blocks} to create in the generated configuration
18673 file, the elements should be of type
18674 @code{<nginx-server-configuration>}.
18676 The following example would setup NGinx to serve @code{www.example.com}
18677 from the @code{/srv/http/www.example.com} directory, without using
18680 (service nginx-service-type
18681 (nginx-configuration
18683 (list (nginx-server-configuration
18684 (server-name '("www.example.com"))
18685 (root "/srv/http/www.example.com"))))))
18688 @item @code{upstream-blocks} (default: @code{'()})
18689 A list of @dfn{upstream blocks} to create in the generated configuration
18690 file, the elements should be of type
18691 @code{<nginx-upstream-configuration>}.
18693 Configuring upstreams through the @code{upstream-blocks} can be useful
18694 when combined with @code{locations} in the
18695 @code{<nginx-server-configuration>} records. The following example
18696 creates a server configuration with one location configuration, that
18697 will proxy requests to a upstream configuration, which will handle
18698 requests with two servers.
18703 (nginx-configuration
18705 (list (nginx-server-configuration
18706 (server-name '("www.example.com"))
18707 (root "/srv/http/www.example.com")
18710 (nginx-location-configuration
18712 (body '("proxy_pass http://server-proxy;"))))))))
18714 (list (nginx-upstream-configuration
18715 (name "server-proxy")
18716 (servers (list "server1.example.com"
18717 "server2.example.com")))))))
18720 @item @code{file} (default: @code{#f})
18721 If a configuration @var{file} is provided, this will be used, rather than
18722 generating a configuration file from the provided @code{log-directory},
18723 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
18724 proper operation, these arguments should match what is in @var{file} to ensure
18725 that the directories are created when the service is activated.
18727 This can be useful if you have an existing configuration file, or it's
18728 not possible to do what is required through the other parts of the
18729 nginx-configuration record.
18731 @item @code{server-names-hash-bucket-size} (default: @code{#f})
18732 Bucket size for the server names hash tables, defaults to @code{#f} to
18733 use the size of the processors cache line.
18735 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
18736 Maximum bucket size for the server names hash tables.
18738 @item @code{extra-content} (default: @code{""})
18739 Extra content for the @code{http} block. Should be string or a string
18740 valued G-expression.
18745 @deftp {Data Type} nginx-server-configuration
18746 Data type representing the configuration of an nginx server block.
18747 This type has the following parameters:
18750 @item @code{listen} (default: @code{'("80" "443 ssl")})
18751 Each @code{listen} directive sets the address and port for IP, or the
18752 path for a UNIX-domain socket on which the server will accept requests.
18753 Both address and port, or only address or only port can be specified.
18754 An address may also be a hostname, for example:
18757 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
18760 @item @code{server-name} (default: @code{(list 'default)})
18761 A list of server names this server represents. @code{'default} represents the
18762 default server for connections matching no other server.
18764 @item @code{root} (default: @code{"/srv/http"})
18765 Root of the website nginx will serve.
18767 @item @code{locations} (default: @code{'()})
18768 A list of @dfn{nginx-location-configuration} or
18769 @dfn{nginx-named-location-configuration} records to use within this
18772 @item @code{index} (default: @code{(list "index.html")})
18773 Index files to look for when clients ask for a directory. If it cannot be found,
18774 Nginx will send the list of files in the directory.
18776 @item @code{try-files} (default: @code{'()})
18777 A list of files whose existence is checked in the specified order.
18778 @code{nginx} will use the first file it finds to process the request.
18780 @item @code{ssl-certificate} (default: @code{#f})
18781 Where to find the certificate for secure connections. Set it to @code{#f} if
18782 you don't have a certificate or you don't want to use HTTPS.
18784 @item @code{ssl-certificate-key} (default: @code{#f})
18785 Where to find the private key for secure connections. Set it to @code{#f} if
18786 you don't have a key or you don't want to use HTTPS.
18788 @item @code{server-tokens?} (default: @code{#f})
18789 Whether the server should add its configuration to response.
18791 @item @code{raw-content} (default: @code{'()})
18792 A list of raw lines added to the server block.
18797 @deftp {Data Type} nginx-upstream-configuration
18798 Data type representing the configuration of an nginx @code{upstream}
18799 block. This type has the following parameters:
18803 Name for this group of servers.
18805 @item @code{servers}
18806 Specify the addresses of the servers in the group. The address can be
18807 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
18808 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
18809 prefix @samp{unix:}. For addresses using an IP address or domain name,
18810 the default port is 80, and a different port can be specified
18816 @deftp {Data Type} nginx-location-configuration
18817 Data type representing the configuration of an nginx @code{location}
18818 block. This type has the following parameters:
18822 URI which this location block matches.
18824 @anchor{nginx-location-configuration body}
18826 Body of the location block, specified as a list of strings. This can contain
18828 configuration directives. For example, to pass requests to a upstream
18829 server group defined using an @code{nginx-upstream-configuration} block,
18830 the following directive would be specified in the body @samp{(list "proxy_pass
18831 http://upstream-name;")}.
18836 @deftp {Data Type} nginx-named-location-configuration
18837 Data type representing the configuration of an nginx named location
18838 block. Named location blocks are used for request redirection, and not
18839 used for regular request processing. This type has the following
18844 Name to identify this location block.
18847 @xref{nginx-location-configuration body}, as the body for named location
18848 blocks can be used in a similar way to the
18849 @code{nginx-location-configuration body}. One restriction is that the
18850 body of a named location block cannot contain location blocks.
18855 @subsubheading Varnish Cache
18857 Varnish is a fast cache server that sits in between web applications
18858 and end users. It proxies requests from clients and caches the
18859 accessed URLs such that multiple requests for the same resource only
18860 creates one request to the back-end.
18862 @defvr {Scheme Variable} varnish-service-type
18863 Service type for the Varnish daemon.
18866 @deftp {Data Type} varnish-configuration
18867 Data type representing the @code{varnish} service configuration.
18868 This type has the following parameters:
18871 @item @code{package} (default: @code{varnish})
18872 The Varnish package to use.
18874 @item @code{name} (default: @code{"default"})
18875 A name for this Varnish instance. Varnish will create a directory in
18876 @file{/var/varnish/} with this name and keep temporary files there. If
18877 the name starts with a forward slash, it is interpreted as an absolute
18880 Pass the @code{-n} argument to other Varnish programs to connect to the
18881 named instance, e.g.@: @command{varnishncsa -n default}.
18883 @item @code{backend} (default: @code{"localhost:8080"})
18884 The backend to use. This option has no effect if @code{vcl} is set.
18886 @item @code{vcl} (default: #f)
18887 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
18888 is @code{#f}, Varnish will proxy @code{backend} using the default
18889 configuration. Otherwise this must be a file-like object with valid
18892 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
18893 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
18894 can do something along these lines:
18897 (define %gnu-mirror
18901 backend gnu @{ .host = "www.gnu.org"; @}"))
18905 (services (cons (service varnish-service-type
18906 (varnish-configuration
18908 (vcl %gnu-mirror)))
18912 The configuration of an already running Varnish instance can be inspected
18913 and changed using the @command{varnishadm} program.
18915 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
18916 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
18917 comprehensive documentation on Varnish and its configuration language.
18919 @item @code{listen} (default: @code{'("localhost:80")})
18920 List of addresses Varnish will listen on.
18922 @item @code{storage} (default: @code{'("malloc,128m")})
18923 List of storage backends that will be available in VCL.
18925 @item @code{parameters} (default: @code{'()})
18926 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
18928 @item @code{extra-options} (default: @code{'()})
18929 Additional arguments to pass to the @command{varnishd} process.
18934 @subsubheading FastCGI
18937 FastCGI is an interface between the front-end and the back-end of a web
18938 service. It is a somewhat legacy facility; new web services should
18939 generally just talk HTTP between the front-end and the back-end.
18940 However there are a number of back-end services such as PHP or the
18941 optimized HTTP Git repository access that use FastCGI, so we have
18942 support for it in Guix.
18944 To use FastCGI, you configure the front-end web server (e.g., nginx) to
18945 dispatch some subset of its requests to the fastcgi backend, which
18946 listens on a local TCP or UNIX socket. There is an intermediary
18947 @code{fcgiwrap} program that sits between the actual backend process and
18948 the web server. The front-end indicates which backend program to run,
18949 passing that information to the @code{fcgiwrap} process.
18951 @defvr {Scheme Variable} fcgiwrap-service-type
18952 A service type for the @code{fcgiwrap} FastCGI proxy.
18955 @deftp {Data Type} fcgiwrap-configuration
18956 Data type representing the configuration of the @code{fcgiwrap} service.
18957 This type has the following parameters:
18959 @item @code{package} (default: @code{fcgiwrap})
18960 The fcgiwrap package to use.
18962 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
18963 The socket on which the @code{fcgiwrap} process should listen, as a
18964 string. Valid @var{socket} values include
18965 @code{unix:@var{/path/to/unix/socket}},
18966 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
18967 @code{tcp6:[@var{ipv6_addr}]:port}.
18969 @item @code{user} (default: @code{fcgiwrap})
18970 @itemx @code{group} (default: @code{fcgiwrap})
18971 The user and group names, as strings, under which to run the
18972 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
18973 the user asks for the specific user or group names @code{fcgiwrap} that
18974 the corresponding user and/or group is present on the system.
18976 It is possible to configure a FastCGI-backed web service to pass HTTP
18977 authentication information from the front-end to the back-end, and to
18978 allow @code{fcgiwrap} to run the back-end process as a corresponding
18979 local user. To enable this capability on the back-end., run
18980 @code{fcgiwrap} as the @code{root} user and group. Note that this
18981 capability also has to be configured on the front-end as well.
18986 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
18987 with some additional features useful for sites of any size.
18989 These features include:
18991 @item Adaptive process spawning
18992 @item Basic statistics (similar to Apache's mod_status)
18993 @item Advanced process management with graceful stop/start
18994 @item Ability to start workers with different uid/gid/chroot/environment
18995 and different php.ini (replaces safe_mode)
18996 @item Stdout & stderr logging
18997 @item Emergency restart in case of accidental opcode cache destruction
18998 @item Accelerated upload support
18999 @item Support for a "slowlog"
19000 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
19001 a special function to finish request & flush all data while continuing to do
19002 something time-consuming (video converting, stats processing, etc.)
19004 ...@: and much more.
19006 @defvr {Scheme Variable} php-fpm-service-type
19007 A Service type for @code{php-fpm}.
19010 @deftp {Data Type} php-fpm-configuration
19011 Data Type for php-fpm service configuration.
19013 @item @code{php} (default: @code{php})
19014 The php package to use.
19015 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
19016 The address on which to accept FastCGI requests. Valid syntaxes are:
19018 @item @code{"ip.add.re.ss:port"}
19019 Listen on a TCP socket to a specific address on a specific port.
19020 @item @code{"port"}
19021 Listen on a TCP socket to all addresses on a specific port.
19022 @item @code{"/path/to/unix/socket"}
19023 Listen on a unix socket.
19026 @item @code{user} (default: @code{php-fpm})
19027 User who will own the php worker processes.
19028 @item @code{group} (default: @code{php-fpm})
19029 Group of the worker processes.
19030 @item @code{socket-user} (default: @code{php-fpm})
19031 User who can speak to the php-fpm socket.
19032 @item @code{socket-group} (default: @code{php-fpm})
19033 Group that can speak to the php-fpm socket.
19034 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
19035 The process id of the php-fpm process is written to this file
19036 once the service has started.
19037 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
19038 Log for the php-fpm master process.
19039 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
19040 Detailed settings for the php-fpm process manager.
19043 @item @code{<php-fpm-dynamic-process-manager-configuration>}
19044 @item @code{<php-fpm-static-process-manager-configuration>}
19045 @item @code{<php-fpm-on-demand-process-manager-configuration>}
19047 @item @code{display-errors} (default @code{#f})
19048 Determines whether php errors and warning should be sent to clients
19049 and displayed in their browsers.
19050 This is useful for local php development, but a security risk for public sites,
19051 as error messages can reveal passwords and personal data.
19052 @item @code{timezone} (default @code{#f})
19053 Specifies @code{php_admin_value[date.timezone]} parameter.
19054 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
19055 This file will log the @code{stderr} outputs of php worker processes.
19056 Can be set to @code{#f} to disable logging.
19057 @item @code{file} (default @code{#f})
19058 An optional override of the whole configuration.
19059 You can use the @code{mixed-text-file} function or an absolute filepath for it.
19063 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
19064 Data Type for the @code{dynamic} php-fpm process manager. With the
19065 @code{dynamic} process manager, spare worker processes are kept around
19066 based on it's configured limits.
19068 @item @code{max-children} (default: @code{5})
19069 Maximum of worker processes.
19070 @item @code{start-servers} (default: @code{2})
19071 How many worker processes should be started on start-up.
19072 @item @code{min-spare-servers} (default: @code{1})
19073 How many spare worker processes should be kept around at minimum.
19074 @item @code{max-spare-servers} (default: @code{3})
19075 How many spare worker processes should be kept around at maximum.
19079 @deftp {Data type} php-fpm-static-process-manager-configuration
19080 Data Type for the @code{static} php-fpm process manager. With the
19081 @code{static} process manager, an unchanging number of worker processes
19084 @item @code{max-children} (default: @code{5})
19085 Maximum of worker processes.
19089 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
19090 Data Type for the @code{on-demand} php-fpm process manager. With the
19091 @code{on-demand} process manager, worker processes are only created as
19094 @item @code{max-children} (default: @code{5})
19095 Maximum of worker processes.
19096 @item @code{process-idle-timeout} (default: @code{10})
19097 The time in seconds after which a process with no requests is killed.
19102 @deffn {Scheme Procedure} nginx-php-fpm-location @
19103 [#:nginx-package nginx] @
19104 [socket (string-append "/var/run/php" @
19105 (version-major (package-version php)) @
19107 A helper function to quickly add php to an @code{nginx-server-configuration}.
19110 A simple services setup for nginx with php can look like this:
19112 (services (cons* (service dhcp-client-service-type)
19113 (service php-fpm-service-type)
19114 (service nginx-service-type
19115 (nginx-server-configuration
19116 (server-name '("example.com"))
19117 (root "/srv/http/")
19119 (list (nginx-php-location)))
19121 (ssl-certificate #f)
19122 (ssl-certificate-key #f)))
19126 @cindex cat-avatar-generator
19127 The cat avatar generator is a simple service to demonstrate the use of php-fpm
19128 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
19129 the hash of a user's email address.
19131 @deffn {Scheme Procedure} cat-avatar-generator-service @
19132 [#:cache-dir "/var/cache/cat-avatar-generator"] @
19133 [#:package cat-avatar-generator] @
19134 [#:configuration (nginx-server-configuration)]
19135 Returns an nginx-server-configuration that inherits @code{configuration}. It
19136 extends the nginx configuration to add a server block that serves @code{package},
19137 a version of cat-avatar-generator. During execution, cat-avatar-generator will
19138 be able to use @code{cache-dir} as its cache directory.
19141 A simple setup for cat-avatar-generator can look like this:
19143 (services (cons* (cat-avatar-generator-service
19145 (nginx-server-configuration
19146 (server-name '("example.com"))))
19151 @subsubheading Hpcguix-web
19153 @cindex hpcguix-web
19154 The @uref{hpcguix-web, https://github.com/UMCUGenetics/hpcguix-web/}
19155 program is a customizable web interface to browse Guix packages,
19156 initially designed for users of high-performance computing (HPC)
19159 @defvr {Scheme Variable} hpcguix-web-service-type
19160 The service type for @code{hpcguix-web}.
19163 @deftp {Data Type} hpcguix-web-configuration
19164 Data type for the hpcguix-web service configuration.
19168 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
19169 configuration. The main items available in this spec are:
19172 @item @code{title-prefix} (default: @code{"hpcguix | "})
19173 The page title prefix.
19175 @item @code{guix-command} (default: @code{"guix"})
19176 The @command{guix} command.
19178 @item @code{package-filter-proc} (default: @code{(const #t)})
19179 A procedure specifying how to filter packages that are displayed.
19181 @item @code{package-page-extension-proc} (default: @code{(const '())})
19182 Extension package for @code{hpcguix-web}.
19184 @item @code{menu} (default: @code{'()})
19185 Additional entry in page @code{menu}.
19187 @item @code{channels} (default: @code{%default-channels})
19188 List of channels from which the package list is built (@pxref{Channels}).
19190 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
19191 The expiration time, in seconds, after which the package list is rebuilt from
19192 the latest instances of the given channels.
19195 See the hpcguix-web repository for a
19196 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
19199 @item @code{package} (default: @code{hpcguix-web})
19200 The hpcguix-web package to use.
19204 A typical hpcguix-web service declaration looks like this:
19207 (service hpcguix-web-service-type
19208 (hpcguix-web-configuration
19210 #~(define site-config
19211 (hpcweb-configuration
19212 (title-prefix "Guix-HPC - ")
19213 (menu '(("/about" "ABOUT"))))))))
19217 The hpcguix-web service periodically updates the package list it publishes by
19218 pulling channels from Git. To that end, it needs to access X.509 certificates
19219 so that it can authenticate Git servers when communicating over HTTPS, and it
19220 assumes that @file{/etc/ssl/certs} contains those certificates.
19222 Thus, make sure to add @code{nss-certs} or another certificate package to the
19223 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
19224 more information on X.509 certificates.
19227 @node Certificate Services
19228 @subsection Certificate Services
19231 @cindex HTTP, HTTPS
19232 @cindex Let's Encrypt
19233 @cindex TLS certificates
19234 The @code{(gnu services certbot)} module provides a service to
19235 automatically obtain a valid TLS certificate from the Let's Encrypt
19236 certificate authority. These certificates can then be used to serve
19237 content securely over HTTPS or other TLS-based protocols, with the
19238 knowledge that the client will be able to verify the server's
19241 @url{https://letsencrypt.org/, Let's Encrypt} provides the
19242 @code{certbot} tool to automate the certification process. This tool
19243 first securely generates a key on the server. It then makes a request
19244 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
19245 checks that the request originates from the host in question by using a
19246 challenge-response protocol, requiring the server to provide its
19247 response over HTTP. If that protocol completes successfully, the CA
19248 signs the key, resulting in a certificate. That certificate is valid
19249 for a limited period of time, and therefore to continue to provide TLS
19250 services, the server needs to periodically ask the CA to renew its
19253 The certbot service automates this process: the initial key
19254 generation, the initial certification request to the Let's Encrypt
19255 service, the web server challenge/response integration, writing the
19256 certificate to disk, the automated periodic renewals, and the deployment
19257 tasks associated with the renewal (e.g.@: reloading services, copying keys
19258 with different permissions).
19260 Certbot is run twice a day, at a random minute within the hour. It
19261 won't do anything until your certificates are due for renewal or
19262 revoked, but running it regularly would give your service a chance of
19263 staying online in case a Let's Encrypt-initiated revocation happened for
19266 By using this service, you agree to the ACME Subscriber Agreement, which
19267 can be found there:
19268 @url{https://acme-v01.api.letsencrypt.org/directory}.
19270 @defvr {Scheme Variable} certbot-service-type
19271 A service type for the @code{certbot} Let's Encrypt client. Its value
19272 must be a @code{certbot-configuration} record as in this example:
19275 (define %nginx-deploy-hook
19277 "nginx-deploy-hook"
19278 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
19279 (kill pid SIGHUP))))
19281 (service certbot-service-type
19282 (certbot-configuration
19283 (email "foo@@example.net")
19286 (certificate-configuration
19287 (domains '("example.net" "www.example.net"))
19288 (deploy-hook %nginx-deploy-hook))
19289 (certificate-configuration
19290 (domains '("bar.example.net")))))))
19293 See below for details about @code{certbot-configuration}.
19296 @deftp {Data Type} certbot-configuration
19297 Data type representing the configuration of the @code{certbot} service.
19298 This type has the following parameters:
19301 @item @code{package} (default: @code{certbot})
19302 The certbot package to use.
19304 @item @code{webroot} (default: @code{/var/www})
19305 The directory from which to serve the Let's Encrypt challenge/response
19308 @item @code{certificates} (default: @code{()})
19309 A list of @code{certificates-configuration}s for which to generate
19310 certificates and request signatures. Each certificate has a @code{name}
19311 and several @code{domains}.
19314 Mandatory email used for registration, recovery contact, and important
19315 account notifications.
19317 @item @code{rsa-key-size} (default: @code{2048})
19318 Size of the RSA key.
19320 @item @code{default-location} (default: @i{see below})
19321 The default @code{nginx-location-configuration}. Because @code{certbot}
19322 needs to be able to serve challenges and responses, it needs to be able
19323 to run a web server. It does so by extending the @code{nginx} web
19324 service with an @code{nginx-server-configuration} listening on the
19325 @var{domains} on port 80, and which has a
19326 @code{nginx-location-configuration} for the @code{/.well-known/} URI
19327 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
19328 these nginx configuration data types.
19330 Requests to other URL paths will be matched by the
19331 @code{default-location}, which if present is added to all
19332 @code{nginx-server-configuration}s.
19334 By default, the @code{default-location} will issue a redirect from
19335 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
19336 you to define what to serve on your site via @code{https}.
19338 Pass @code{#f} to not issue a default location.
19342 @deftp {Data Type} certificate-configuration
19343 Data type representing the configuration of a certificate.
19344 This type has the following parameters:
19347 @item @code{name} (default: @i{see below})
19348 This name is used by Certbot for housekeeping and in file paths; it
19349 doesn't affect the content of the certificate itself. To see
19350 certificate names, run @code{certbot certificates}.
19352 Its default is the first provided domain.
19354 @item @code{domains} (default: @code{()})
19355 The first domain provided will be the subject CN of the certificate, and
19356 all domains will be Subject Alternative Names on the certificate.
19358 @item @code{deploy-hook} (default: @code{#f})
19359 Command to be run in a shell once for each successfully issued
19360 certificate. For this command, the shell variable
19361 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
19362 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
19363 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
19364 contain a space-delimited list of renewed certificate domains (for
19365 example, @samp{"example.com www.example.com"}.
19370 For each @code{certificate-configuration}, the certificate is saved to
19371 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
19372 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
19374 @subsection DNS Services
19375 @cindex DNS (domain name system)
19376 @cindex domain name system (DNS)
19378 The @code{(gnu services dns)} module provides services related to the
19379 @dfn{domain name system} (DNS). It provides a server service for hosting
19380 an @emph{authoritative} DNS server for multiple zones, slave or master.
19381 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
19382 caching and forwarding DNS server for the LAN, which uses
19383 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
19385 @subsubheading Knot Service
19387 An example configuration of an authoritative server for two zones, one master
19391 (define-zone-entries example.org.zone
19392 ;; Name TTL Class Type Data
19393 ("@@" "" "IN" "A" "127.0.0.1")
19394 ("@@" "" "IN" "NS" "ns")
19395 ("ns" "" "IN" "A" "127.0.0.1"))
19397 (define master-zone
19398 (knot-zone-configuration
19399 (domain "example.org")
19401 (origin "example.org")
19402 (entries example.org.zone)))))
19405 (knot-zone-configuration
19406 (domain "plop.org")
19407 (dnssec-policy "default")
19408 (master (list "plop-master"))))
19410 (define plop-master
19411 (knot-remote-configuration
19413 (address (list "208.76.58.171"))))
19417 (services (cons* (service knot-service-type
19418 (knot-configuration
19419 (remotes (list plop-master))
19420 (zones (list master-zone slave-zone))))
19425 @deffn {Scheme Variable} knot-service-type
19426 This is the type for the Knot DNS server.
19428 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
19429 zones, that is to say domain names you would buy from a registrar. This server
19430 is not a resolver, meaning that it can only resolve names for which it is
19431 authoritative. This server can be configured to serve zones as a master server
19432 or a slave server as a per-zone basis. Slave zones will get their data from
19433 masters, and will serve it as an authoritative server. From the point of view
19434 of a resolver, there is no difference between master and slave.
19436 The following data types are used to configure the Knot DNS server:
19439 @deftp {Data Type} knot-key-configuration
19440 Data type representing a key.
19441 This type has the following parameters:
19444 @item @code{id} (default: @code{""})
19445 An identifier for other configuration fields to refer to this key. IDs must
19446 be unique and must not be empty.
19448 @item @code{algorithm} (default: @code{#f})
19449 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
19450 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
19451 and @code{'hmac-sha512}.
19453 @item @code{secret} (default: @code{""})
19454 The secret key itself.
19459 @deftp {Data Type} knot-acl-configuration
19460 Data type representing an Access Control List (ACL) configuration.
19461 This type has the following parameters:
19464 @item @code{id} (default: @code{""})
19465 An identifier for ether configuration fields to refer to this key. IDs must be
19466 unique and must not be empty.
19468 @item @code{address} (default: @code{'()})
19469 An ordered list of IP addresses, network subnets, or network ranges represented
19470 with strings. The query must match one of them. Empty value means that
19471 address match is not required.
19473 @item @code{key} (default: @code{'()})
19474 An ordered list of references to keys represented with strings. The string
19475 must match a key ID defined in a @code{knot-key-configuration}. No key means
19476 that a key is not require to match that ACL.
19478 @item @code{action} (default: @code{'()})
19479 An ordered list of actions that are permitted or forbidden by this ACL. Possible
19480 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
19481 and @code{'update}.
19483 @item @code{deny?} (default: @code{#f})
19484 When true, the ACL defines restrictions. Listed actions are forbidden. When
19485 false, listed actions are allowed.
19490 @deftp {Data Type} zone-entry
19491 Data type represnting a record entry in a zone file.
19492 This type has the following parameters:
19495 @item @code{name} (default: @code{"@@"})
19496 The name of the record. @code{"@@"} refers to the origin of the zone. Names
19497 are relative to the origin of the zone. For example, in the @code{example.org}
19498 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
19499 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
19500 refers to @code{ns.example.org}.
19502 @item @code{ttl} (default: @code{""})
19503 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
19505 @item @code{class} (default: @code{"IN"})
19506 The class of the record. Knot currently supports only @code{"IN"} and
19507 partially @code{"CH"}.
19509 @item @code{type} (default: @code{"A"})
19510 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
19511 address), NS (Name Server) and MX (Mail eXchange). Many other types are
19514 @item @code{data} (default: @code{""})
19515 The data contained in the record. For instance an IP address associated with
19516 an A record, or a domain name associated with an NS record. Remember that
19517 domain names are relative to the origin unless they end with a dot.
19522 @deftp {Data Type} zone-file
19523 Data type representing the content of a zone file.
19524 This type has the following parameters:
19527 @item @code{entries} (default: @code{'()})
19528 The list of entries. The SOA record is taken care of, so you don't need to
19529 put it in the list of entries. This list should probably contain an entry
19530 for your primary authoritative DNS server. Other than using a list of entries
19531 directly, you can use @code{define-zone-entries} to define a object containing
19532 the list of entries more easily, that you can later pass to the @code{entries}
19533 field of the @code{zone-file}.
19535 @item @code{origin} (default: @code{""})
19536 The name of your zone. This parameter cannot be empty.
19538 @item @code{ns} (default: @code{"ns"})
19539 The domain of your primary authoritative DNS server. The name is relative to
19540 the origin, unless it ends with a dot. It is mandatory that this primary
19541 DNS server corresponds to an NS record in the zone and that it is associated
19542 to an IP address in the list of entries.
19544 @item @code{mail} (default: @code{"hostmaster"})
19545 An email address people can contact you at, as the owner of the zone. This
19546 is translated as @code{<mail>@@<origin>}.
19548 @item @code{serial} (default: @code{1})
19549 The serial number of the zone. As this is used to keep track of changes by
19550 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
19551 Always increment it when you make a change in your zone.
19553 @item @code{refresh} (default: @code{(* 2 24 3600)})
19554 The frequency at which slaves will do a zone transfer. This value is a number
19555 of seconds. It can be computed by multiplications or with
19556 @code{(string->duration)}.
19558 @item @code{retry} (default: @code{(* 15 60)})
19559 The period after which a slave will retry to contact its master when it fails
19560 to do so a first time.
19562 @item @code{expiry} (default: @code{(* 14 24 3600)})
19563 Default TTL of records. Existing records are considered correct for at most
19564 this amount of time. After this period, resolvers will invalidate their cache
19565 and check again that it still exists.
19567 @item @code{nx} (default: @code{3600})
19568 Default TTL of inexistant records. This delay is usually short because you want
19569 your new domains to reach everyone quickly.
19574 @deftp {Data Type} knot-remote-configuration
19575 Data type representing a remote configuration.
19576 This type has the following parameters:
19579 @item @code{id} (default: @code{""})
19580 An identifier for other configuration fields to refer to this remote. IDs must
19581 be unique and must not be empty.
19583 @item @code{address} (default: @code{'()})
19584 An ordered list of destination IP addresses. Addresses are tried in sequence.
19585 An optional port can be given with the @@ separator. For instance:
19586 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
19588 @item @code{via} (default: @code{'()})
19589 An ordered list of source IP addresses. An empty list will have Knot choose
19590 an appropriate source IP. An optional port can be given with the @@ separator.
19591 The default is to choose at random.
19593 @item @code{key} (default: @code{#f})
19594 A reference to a key, that is a string containing the identifier of a key
19595 defined in a @code{knot-key-configuration} field.
19600 @deftp {Data Type} knot-keystore-configuration
19601 Data type representing a keystore to hold dnssec keys.
19602 This type has the following parameters:
19605 @item @code{id} (default: @code{""})
19606 The id of the keystore. It must not be empty.
19608 @item @code{backend} (default: @code{'pem})
19609 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
19611 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
19612 The configuration string of the backend. An example for the PKCS#11 is:
19613 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
19614 For the pem backend, the string reprensents a path in the file system.
19619 @deftp {Data Type} knot-policy-configuration
19620 Data type representing a dnssec policy. Knot DNS is able to automatically
19621 sign your zones. It can either generate and manage your keys automatically or
19622 use keys that you generate.
19624 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
19625 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
19626 zone. In order to be trusted, the KSK needs to be present in the parent zone
19627 (usually a top-level domain). If your registrar supports dnssec, you will
19628 have to send them your KSK's hash so they can add a DS record in their zone.
19629 This is not automated and need to be done each time you change your KSK.
19631 The policy also defines the lifetime of keys. Usually, ZSK can be changed
19632 easily and use weaker cryptographic functions (they use lower parameters) in
19633 order to sign records quickly, so they are changed often. The KSK however
19634 requires manual interaction with the registrar, so they are changed less often
19635 and use stronger parameters because they sign only one record.
19637 This type has the following parameters:
19640 @item @code{id} (default: @code{""})
19641 The id of the policy. It must not be empty.
19643 @item @code{keystore} (default: @code{"default"})
19644 A reference to a keystore, that is a string containing the identifier of a
19645 keystore defined in a @code{knot-keystore-configuration} field. The
19646 @code{"default"} identifier means the default keystore (a kasp database that
19647 was setup by this service).
19649 @item @code{manual?} (default: @code{#f})
19650 Whether the key management is manual or automatic.
19652 @item @code{single-type-signing?} (default: @code{#f})
19653 When @code{#t}, use the Single-Type Signing Scheme.
19655 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
19656 An algorithm of signing keys and issued signatures.
19658 @item @code{ksk-size} (default: @code{256})
19659 The length of the KSK. Note that this value is correct for the default
19660 algorithm, but would be unsecure for other algorithms.
19662 @item @code{zsk-size} (default: @code{256})
19663 The length of the ZSK. Note that this value is correct for the default
19664 algorithm, but would be unsecure for other algorithms.
19666 @item @code{dnskey-ttl} (default: @code{'default})
19667 The TTL value for DNSKEY records added into zone apex. The special
19668 @code{'default} value means same as the zone SOA TTL.
19670 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
19671 The period between ZSK publication and the next rollover initiation.
19673 @item @code{propagation-delay} (default: @code{(* 24 3600)})
19674 An extra delay added for each key rollover step. This value should be high
19675 enough to cover propagation of data from the master server to all slaves.
19677 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
19678 A validity period of newly issued signatures.
19680 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
19681 A period how long before a signature expiration the signature will be refreshed.
19683 @item @code{nsec3?} (default: @code{#f})
19684 When @code{#t}, NSEC3 will be used instead of NSEC.
19686 @item @code{nsec3-iterations} (default: @code{5})
19687 The number of additional times the hashing is performed.
19689 @item @code{nsec3-salt-length} (default: @code{8})
19690 The length of a salt field in octets, which is appended to the original owner
19691 name before hashing.
19693 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
19694 The validity period of newly issued salt field.
19699 @deftp {Data Type} knot-zone-configuration
19700 Data type representing a zone served by Knot.
19701 This type has the following parameters:
19704 @item @code{domain} (default: @code{""})
19705 The domain served by this configuration. It must not be empty.
19707 @item @code{file} (default: @code{""})
19708 The file where this zone is saved. This parameter is ignored by master zones.
19709 Empty means default location that depends on the domain name.
19711 @item @code{zone} (default: @code{(zone-file)})
19712 The content of the zone file. This parameter is ignored by slave zones. It
19713 must contain a zone-file record.
19715 @item @code{master} (default: @code{'()})
19716 A list of master remotes. When empty, this zone is a master. When set, this
19717 zone is a slave. This is a list of remotes identifiers.
19719 @item @code{ddns-master} (default: @code{#f})
19720 The main master. When empty, it defaults to the first master in the list of
19723 @item @code{notify} (default: @code{'()})
19724 A list of slave remote identifiers.
19726 @item @code{acl} (default: @code{'()})
19727 A list of acl identifiers.
19729 @item @code{semantic-checks?} (default: @code{#f})
19730 When set, this adds more semantic checks to the zone.
19732 @item @code{disable-any?} (default: @code{#f})
19733 When set, this forbids queries of the ANY type.
19735 @item @code{zonefile-sync} (default: @code{0})
19736 The delay between a modification in memory and on disk. 0 means immediate
19739 @item @code{serial-policy} (default: @code{'increment})
19740 A policy between @code{'increment} and @code{'unixtime}.
19745 @deftp {Data Type} knot-configuration
19746 Data type representing the Knot configuration.
19747 This type has the following parameters:
19750 @item @code{knot} (default: @code{knot})
19753 @item @code{run-directory} (default: @code{"/var/run/knot"})
19754 The run directory. This directory will be used for pid file and sockets.
19756 @item @code{listen-v4} (default: @code{"0.0.0.0"})
19757 An ip address on which to listen.
19759 @item @code{listen-v6} (default: @code{"::"})
19760 An ip address on which to listen.
19762 @item @code{listen-port} (default: @code{53})
19763 A port on which to listen.
19765 @item @code{keys} (default: @code{'()})
19766 The list of knot-key-configuration used by this configuration.
19768 @item @code{acls} (default: @code{'()})
19769 The list of knot-acl-configuration used by this configuration.
19771 @item @code{remotes} (default: @code{'()})
19772 The list of knot-remote-configuration used by this configuration.
19774 @item @code{zones} (default: @code{'()})
19775 The list of knot-zone-configuration used by this configuration.
19780 @subsubheading Dnsmasq Service
19782 @deffn {Scheme Variable} dnsmasq-service-type
19783 This is the type of the dnsmasq service, whose value should be an
19784 @code{dnsmasq-configuration} object as in this example:
19787 (service dnsmasq-service-type
19788 (dnsmasq-configuration
19790 (servers '("192.168.1.1"))))
19794 @deftp {Data Type} dnsmasq-configuration
19795 Data type representing the configuration of dnsmasq.
19798 @item @code{package} (default: @var{dnsmasq})
19799 Package object of the dnsmasq server.
19801 @item @code{no-hosts?} (default: @code{#f})
19802 When true, don't read the hostnames in /etc/hosts.
19804 @item @code{port} (default: @code{53})
19805 The port to listen on. Setting this to zero completely disables DNS
19806 responses, leaving only DHCP and/or TFTP functions.
19808 @item @code{local-service?} (default: @code{#t})
19809 Accept DNS queries only from hosts whose address is on a local subnet,
19810 ie a subnet for which an interface exists on the server.
19812 @item @code{listen-addresses} (default: @code{'()})
19813 Listen on the given IP addresses.
19815 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
19816 The file to read the IP address of the upstream nameservers from.
19818 @item @code{no-resolv?} (default: @code{#f})
19819 When true, don't read @var{resolv-file}.
19821 @item @code{servers} (default: @code{'()})
19822 Specify IP address of upstream servers directly.
19824 @item @code{cache-size} (default: @code{150})
19825 Set the size of dnsmasq's cache. Setting the cache size to zero
19828 @item @code{negative-cache?} (default: @code{#t})
19829 When false, disable negative caching.
19834 @subsubheading ddclient Service
19837 The ddclient service described below runs the ddclient daemon, which takes
19838 care of automatically updating DNS entries for service providers such as
19839 @uref{https://dyn.com/dns/, Dyn}.
19841 The following example show instantiates the service with its default
19845 (service ddclient-service-type)
19848 Note that ddclient needs to access credentials that are stored in a
19849 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
19850 @code{secret-file} below.) You are expected to create this file manually, in
19851 an ``out-of-band'' fashion (you @emph{could} make this file part of the
19852 service configuration, for instance by using @code{plain-file}, but it will be
19853 world-readable @i{via} @file{/gnu/store}.) See the examples in the
19854 @file{share/ddclient} directory of the @code{ddclient} package.
19856 @c %start of fragment
19858 Available @code{ddclient-configuration} fields are:
19860 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
19861 The ddclient package.
19865 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
19866 The period after which ddclient will retry to check IP and domain name.
19868 Defaults to @samp{300}.
19872 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
19873 Use syslog for the output.
19875 Defaults to @samp{#t}.
19879 @deftypevr {@code{ddclient-configuration} parameter} string mail
19882 Defaults to @samp{"root"}.
19886 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
19887 Mail failed update to user.
19889 Defaults to @samp{"root"}.
19893 @deftypevr {@code{ddclient-configuration} parameter} string pid
19894 The ddclient PID file.
19896 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
19900 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
19901 Enable SSL support.
19903 Defaults to @samp{#t}.
19907 @deftypevr {@code{ddclient-configuration} parameter} string user
19908 Specifies the user name or ID that is used when running ddclient
19911 Defaults to @samp{"ddclient"}.
19915 @deftypevr {@code{ddclient-configuration} parameter} string group
19916 Group of the user who will run the ddclient program.
19918 Defaults to @samp{"ddclient"}.
19922 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
19923 Secret file which will be appended to @file{ddclient.conf} file. This
19924 file contains credentials for use by ddclient. You are expected to
19925 create it manually.
19927 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
19931 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
19932 Extra options will be appended to @file{ddclient.conf} file.
19934 Defaults to @samp{()}.
19939 @c %end of fragment
19943 @subsection VPN Services
19944 @cindex VPN (virtual private network)
19945 @cindex virtual private network (VPN)
19947 The @code{(gnu services vpn)} module provides services related to
19948 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
19949 your machine to connect to a VPN, and a @emph{servire} service for your machine
19950 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
19952 @deffn {Scheme Procedure} openvpn-client-service @
19953 [#:config (openvpn-client-configuration)]
19955 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
19958 @deffn {Scheme Procedure} openvpn-server-service @
19959 [#:config (openvpn-server-configuration)]
19961 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
19963 Both can be run simultaneously.
19966 @c %automatically generated documentation
19968 Available @code{openvpn-client-configuration} fields are:
19970 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
19971 The OpenVPN package.
19975 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
19976 The OpenVPN pid file.
19978 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
19982 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
19983 The protocol (UDP or TCP) used to open a channel between clients and
19986 Defaults to @samp{udp}.
19990 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
19991 The device type used to represent the VPN connection.
19993 Defaults to @samp{tun}.
19997 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
19998 The certificate authority to check connections against.
20000 Defaults to @samp{"/etc/openvpn/ca.crt"}.
20004 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
20005 The certificate of the machine the daemon is running on. It should be
20006 signed by the authority given in @code{ca}.
20008 Defaults to @samp{"/etc/openvpn/client.crt"}.
20012 @deftypevr {@code{openvpn-client-configuration} parameter} string key
20013 The key of the machine the daemon is running on. It must be the key whose
20014 certificate is @code{cert}.
20016 Defaults to @samp{"/etc/openvpn/client.key"}.
20020 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
20021 Whether to use the lzo compression algorithm.
20023 Defaults to @samp{#t}.
20027 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
20028 Don't re-read key files across SIGUSR1 or --ping-restart.
20030 Defaults to @samp{#t}.
20034 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
20035 Don't close and reopen TUN/TAP device or run up/down scripts across
20036 SIGUSR1 or --ping-restart restarts.
20038 Defaults to @samp{#t}.
20042 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
20045 Defaults to @samp{3}.
20049 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
20050 Add an additional layer of HMAC authentication on top of the TLS control
20051 channel to protect against DoS attacks.
20053 Defaults to @samp{#f}.
20057 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
20058 Whether to check the server certificate has server usage extension.
20060 Defaults to @samp{#t}.
20064 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
20065 Bind to a specific local port number.
20067 Defaults to @samp{#f}.
20071 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
20072 Retry resolving server address.
20074 Defaults to @samp{#t}.
20078 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
20079 A list of remote servers to connect to.
20081 Defaults to @samp{()}.
20083 Available @code{openvpn-remote-configuration} fields are:
20085 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
20088 Defaults to @samp{"my-server"}.
20092 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
20093 Port number the server listens to.
20095 Defaults to @samp{1194}.
20100 @c %end of automatic openvpn-client documentation
20102 @c %automatically generated documentation
20104 Available @code{openvpn-server-configuration} fields are:
20106 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
20107 The OpenVPN package.
20111 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
20112 The OpenVPN pid file.
20114 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
20118 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
20119 The protocol (UDP or TCP) used to open a channel between clients and
20122 Defaults to @samp{udp}.
20126 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
20127 The device type used to represent the VPN connection.
20129 Defaults to @samp{tun}.
20133 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
20134 The certificate authority to check connections against.
20136 Defaults to @samp{"/etc/openvpn/ca.crt"}.
20140 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
20141 The certificate of the machine the daemon is running on. It should be
20142 signed by the authority given in @code{ca}.
20144 Defaults to @samp{"/etc/openvpn/client.crt"}.
20148 @deftypevr {@code{openvpn-server-configuration} parameter} string key
20149 The key of the machine the daemon is running on. It must be the key whose
20150 certificate is @code{cert}.
20152 Defaults to @samp{"/etc/openvpn/client.key"}.
20156 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
20157 Whether to use the lzo compression algorithm.
20159 Defaults to @samp{#t}.
20163 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
20164 Don't re-read key files across SIGUSR1 or --ping-restart.
20166 Defaults to @samp{#t}.
20170 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
20171 Don't close and reopen TUN/TAP device or run up/down scripts across
20172 SIGUSR1 or --ping-restart restarts.
20174 Defaults to @samp{#t}.
20178 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
20181 Defaults to @samp{3}.
20185 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
20186 Add an additional layer of HMAC authentication on top of the TLS control
20187 channel to protect against DoS attacks.
20189 Defaults to @samp{#f}.
20193 @deftypevr {@code{openvpn-server-configuration} parameter} number port
20194 Specifies the port number on which the server listens.
20196 Defaults to @samp{1194}.
20200 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
20201 An ip and mask specifying the subnet inside the virtual network.
20203 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
20207 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
20208 A CIDR notation specifying the IPv6 subnet inside the virtual network.
20210 Defaults to @samp{#f}.
20214 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
20215 The Diffie-Hellman parameters file.
20217 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
20221 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
20222 The file that records client IPs.
20224 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
20228 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
20229 When true, the server will act as a gateway for its clients.
20231 Defaults to @samp{#f}.
20235 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
20236 When true, clients are allowed to talk to each other inside the VPN.
20238 Defaults to @samp{#f}.
20242 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
20243 Causes ping-like messages to be sent back and forth over the link so
20244 that each side knows when the other side has gone down. @code{keepalive}
20245 requires a pair. The first element is the period of the ping sending,
20246 and the second element is the timeout before considering the other side
20251 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
20252 The maximum number of clients.
20254 Defaults to @samp{100}.
20258 @deftypevr {@code{openvpn-server-configuration} parameter} string status
20259 The status file. This file shows a small report on current connection.
20260 It is truncated and rewritten every minute.
20262 Defaults to @samp{"/var/run/openvpn/status"}.
20266 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
20267 The list of configuration for some clients.
20269 Defaults to @samp{()}.
20271 Available @code{openvpn-ccd-configuration} fields are:
20273 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
20276 Defaults to @samp{"client"}.
20280 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
20283 Defaults to @samp{#f}.
20287 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
20290 Defaults to @samp{#f}.
20297 @c %end of automatic openvpn-server documentation
20300 @node Network File System
20301 @subsection Network File System
20304 The @code{(gnu services nfs)} module provides the following services,
20305 which are most commonly used in relation to mounting or exporting
20306 directory trees as @dfn{network file systems} (NFS).
20308 @subsubheading RPC Bind Service
20311 The RPC Bind service provides a facility to map program numbers into
20312 universal addresses.
20313 Many NFS related services use this facility. Hence it is automatically
20314 started when a dependent service starts.
20316 @defvr {Scheme Variable} rpcbind-service-type
20317 A service type for the RPC portmapper daemon.
20321 @deftp {Data Type} rpcbind-configuration
20322 Data type representing the configuration of the RPC Bind Service.
20323 This type has the following parameters:
20325 @item @code{rpcbind} (default: @code{rpcbind})
20326 The rpcbind package to use.
20328 @item @code{warm-start?} (default: @code{#t})
20329 If this parameter is @code{#t}, then the daemon will read a
20330 state file on startup thus reloading state information saved by a previous
20336 @subsubheading Pipefs Pseudo File System
20340 The pipefs file system is used to transfer NFS related data
20341 between the kernel and user space programs.
20343 @defvr {Scheme Variable} pipefs-service-type
20344 A service type for the pipefs pseudo file system.
20347 @deftp {Data Type} pipefs-configuration
20348 Data type representing the configuration of the pipefs pseudo file system service.
20349 This type has the following parameters:
20351 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20352 The directory to which the file system is to be attached.
20357 @subsubheading GSS Daemon Service
20360 @cindex global security system
20362 The @dfn{global security system} (GSS) daemon provides strong security for RPC
20364 Before exchanging RPC requests an RPC client must establish a security
20365 context. Typically this is done using the Kerberos command @command{kinit}
20366 or automatically at login time using PAM services (@pxref{Kerberos Services}).
20368 @defvr {Scheme Variable} gss-service-type
20369 A service type for the Global Security System (GSS) daemon.
20372 @deftp {Data Type} gss-configuration
20373 Data type representing the configuration of the GSS daemon service.
20374 This type has the following parameters:
20376 @item @code{nfs-utils} (default: @code{nfs-utils})
20377 The package in which the @command{rpc.gssd} command is to be found.
20379 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20380 The directory where the pipefs file system is mounted.
20386 @subsubheading IDMAP Daemon Service
20388 @cindex name mapper
20390 The idmap daemon service provides mapping between user IDs and user names.
20391 Typically it is required in order to access file systems mounted via NFSv4.
20393 @defvr {Scheme Variable} idmap-service-type
20394 A service type for the Identity Mapper (IDMAP) daemon.
20397 @deftp {Data Type} idmap-configuration
20398 Data type representing the configuration of the IDMAP daemon service.
20399 This type has the following parameters:
20401 @item @code{nfs-utils} (default: @code{nfs-utils})
20402 The package in which the @command{rpc.idmapd} command is to be found.
20404 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20405 The directory where the pipefs file system is mounted.
20407 @item @code{domain} (default: @code{#f})
20408 The local NFSv4 domain name.
20409 This must be a string or @code{#f}.
20410 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
20415 @node Continuous Integration
20416 @subsection Continuous Integration
20418 @cindex continuous integration
20419 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
20420 continuous integration tool for Guix. It can be used both for development and
20421 for providing substitutes to others (@pxref{Substitutes}).
20423 The @code{(gnu services cuirass)} module provides the following service.
20425 @defvr {Scheme Procedure} cuirass-service-type
20426 The type of the Cuirass service. Its value must be a
20427 @code{cuirass-configuration} object, as described below.
20430 To add build jobs, you have to set the @code{specifications} field of the
20431 configuration. Here is an example of a service that polls the Guix repository
20432 and builds the packages from a manifest. Some of the packages are defined in
20433 the @code{"custom-packages"} input, which is the equivalent of
20434 @code{GUIX_PACKAGE_PATH}.
20437 (define %cuirass-specs
20439 '((#:name . "my-manifest")
20440 (#:load-path-inputs . ("guix"))
20441 (#:package-path-inputs . ("custom-packages"))
20442 (#:proc-input . "guix")
20443 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
20444 (#:proc . cuirass-jobs)
20445 (#:proc-args . ((subset . "manifests")
20446 (systems . ("x86_64-linux"))
20447 (manifests . (("config" . "guix/manifest.scm")))))
20448 (#:inputs . (((#:name . "guix")
20449 (#:url . "git://git.savannah.gnu.org/guix.git")
20450 (#:load-path . ".")
20451 (#:branch . "master")
20452 (#:no-compile? . #t))
20453 ((#:name . "config")
20454 (#:url . "git://git.example.org/config.git")
20455 (#:load-path . ".")
20456 (#:branch . "master")
20457 (#:no-compile? . #t))
20458 ((#:name . "custom-packages")
20459 (#:url . "git://git.example.org/custom-packages.git")
20460 (#:load-path . ".")
20461 (#:branch . "master")
20462 (#:no-compile? . #t)))))))
20464 (service cuirass-service-type
20465 (cuirass-configuration
20466 (specifications %cuirass-specs)))
20469 While information related to build jobs is located directly in the
20470 specifications, global settings for the @command{cuirass} process are
20471 accessible in other @code{cuirass-configuration} fields.
20473 @deftp {Data Type} cuirass-configuration
20474 Data type representing the configuration of Cuirass.
20477 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
20478 Location of the log file.
20480 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
20481 Location of the repository cache.
20483 @item @code{user} (default: @code{"cuirass"})
20484 Owner of the @code{cuirass} process.
20486 @item @code{group} (default: @code{"cuirass"})
20487 Owner's group of the @code{cuirass} process.
20489 @item @code{interval} (default: @code{60})
20490 Number of seconds between the poll of the repositories followed by the
20493 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
20494 Location of sqlite database which contains the build results and previously
20495 added specifications.
20497 @item @code{ttl} (default: @code{(* 30 24 3600)})
20498 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
20499 are registered for build results. This means that build results are protected
20500 from garbage collection for at least @var{ttl} seconds.
20502 @item @code{port} (default: @code{8081})
20503 Port number used by the HTTP server.
20505 @item --listen=@var{host}
20506 Listen on the network interface for @var{host}. The default is to
20507 accept connections from localhost.
20509 @item @code{specifications} (default: @code{#~'()})
20510 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
20511 where a specification is an association list
20512 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
20513 keys are keywords (@code{#:keyword-example}) as shown in the example
20516 @item @code{use-substitutes?} (default: @code{#f})
20517 This allows using substitutes to avoid building every dependencies of a job
20520 @item @code{one-shot?} (default: @code{#f})
20521 Only evaluate specifications and build derivations once.
20523 @item @code{fallback?} (default: @code{#f})
20524 When substituting a pre-built binary fails, fall back to building
20527 @item @code{cuirass} (default: @code{cuirass})
20528 The Cuirass package to use.
20532 @node Power Management Services
20533 @subsection Power Management Services
20536 @cindex power management with TLP
20537 @subsubheading TLP daemon
20539 The @code{(gnu services pm)} module provides a Guix service definition
20540 for the Linux power management tool TLP.
20542 TLP enables various powersaving modes in userspace and kernel.
20543 Contrary to @code{upower-service}, it is not a passive,
20544 monitoring tool, as it will apply custom settings each time a new power
20545 source is detected. More information can be found at
20546 @uref{http://linrunner.de/en/tlp/tlp.html, TLP home page}.
20548 @deffn {Scheme Variable} tlp-service-type
20549 The service type for the TLP tool. Its value should be a valid
20550 TLP configuration (see below). To use the default settings, simply
20553 (service tlp-service-type)
20557 By default TLP does not need much configuration but most TLP parameters
20558 can be tweaked using @code{tlp-configuration}.
20560 Each parameter definition is preceded by its type; for example,
20561 @samp{boolean foo} indicates that the @code{foo} parameter
20562 should be specified as a boolean. Types starting with
20563 @code{maybe-} denote parameters that won't show up in TLP config file
20564 when their value is @code{'disabled}.
20566 @c The following documentation was initially generated by
20567 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
20568 @c documentation is better, so we shouldn't hesitate to edit below as
20569 @c needed. However if the change you want to make to this documentation
20570 @c can be done in an automated way, it's probably easier to change
20571 @c (generate-documentation) than to make it below and have to deal with
20572 @c the churn as TLP updates.
20574 Available @code{tlp-configuration} fields are:
20576 @deftypevr {@code{tlp-configuration} parameter} package tlp
20581 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
20582 Set to true if you wish to enable TLP.
20584 Defaults to @samp{#t}.
20588 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
20589 Default mode when no power supply can be detected. Alternatives are AC
20592 Defaults to @samp{"AC"}.
20596 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
20597 Number of seconds Linux kernel has to wait after the disk goes idle,
20598 before syncing on AC.
20600 Defaults to @samp{0}.
20604 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
20605 Same as @code{disk-idle-ac} but on BAT mode.
20607 Defaults to @samp{2}.
20611 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
20612 Dirty pages flushing periodicity, expressed in seconds.
20614 Defaults to @samp{15}.
20618 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
20619 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
20621 Defaults to @samp{60}.
20625 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
20626 CPU frequency scaling governor on AC mode. With intel_pstate driver,
20627 alternatives are powersave and performance. With acpi-cpufreq driver,
20628 alternatives are ondemand, powersave, performance and conservative.
20630 Defaults to @samp{disabled}.
20634 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
20635 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
20637 Defaults to @samp{disabled}.
20641 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
20642 Set the min available frequency for the scaling governor on AC.
20644 Defaults to @samp{disabled}.
20648 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
20649 Set the max available frequency for the scaling governor on AC.
20651 Defaults to @samp{disabled}.
20655 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
20656 Set the min available frequency for the scaling governor on BAT.
20658 Defaults to @samp{disabled}.
20662 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
20663 Set the max available frequency for the scaling governor on BAT.
20665 Defaults to @samp{disabled}.
20669 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
20670 Limit the min P-state to control the power dissipation of the CPU, in AC
20671 mode. Values are stated as a percentage of the available performance.
20673 Defaults to @samp{disabled}.
20677 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
20678 Limit the max P-state to control the power dissipation of the CPU, in AC
20679 mode. Values are stated as a percentage of the available performance.
20681 Defaults to @samp{disabled}.
20685 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
20686 Same as @code{cpu-min-perf-on-ac} on BAT mode.
20688 Defaults to @samp{disabled}.
20692 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
20693 Same as @code{cpu-max-perf-on-ac} on BAT mode.
20695 Defaults to @samp{disabled}.
20699 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
20700 Enable CPU turbo boost feature on AC mode.
20702 Defaults to @samp{disabled}.
20706 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
20707 Same as @code{cpu-boost-on-ac?} on BAT mode.
20709 Defaults to @samp{disabled}.
20713 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
20714 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
20715 used under light load conditions.
20717 Defaults to @samp{#f}.
20721 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
20722 Same as @code{sched-powersave-on-ac?} but on BAT mode.
20724 Defaults to @samp{#t}.
20728 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
20729 Enable Linux kernel NMI watchdog.
20731 Defaults to @samp{#f}.
20735 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
20736 For Linux kernels with PHC patch applied, change CPU voltages. An
20737 example value would be @samp{"F:V F:V F:V F:V"}.
20739 Defaults to @samp{disabled}.
20743 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
20744 Set CPU performance versus energy saving policy on AC. Alternatives are
20745 performance, normal, powersave.
20747 Defaults to @samp{"performance"}.
20751 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
20752 Same as @code{energy-perf-policy-ac} but on BAT mode.
20754 Defaults to @samp{"powersave"}.
20758 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
20763 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
20764 Hard disk advanced power management level.
20768 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
20769 Same as @code{disk-apm-bat} but on BAT mode.
20773 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
20774 Hard disk spin down timeout. One value has to be specified for each
20775 declared hard disk.
20777 Defaults to @samp{disabled}.
20781 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
20782 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
20784 Defaults to @samp{disabled}.
20788 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
20789 Select IO scheduler for disk devices. One value has to be specified for
20790 each declared hard disk. Example alternatives are cfq, deadline and
20793 Defaults to @samp{disabled}.
20797 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
20798 SATA aggressive link power management (ALPM) level. Alternatives are
20799 min_power, medium_power, max_performance.
20801 Defaults to @samp{"max_performance"}.
20805 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
20806 Same as @code{sata-linkpwr-ac} but on BAT mode.
20808 Defaults to @samp{"min_power"}.
20812 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
20813 Exclude specified SATA host devices for link power management.
20815 Defaults to @samp{disabled}.
20819 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
20820 Enable Runtime Power Management for AHCI controller and disks on AC
20823 Defaults to @samp{disabled}.
20827 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
20828 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
20830 Defaults to @samp{disabled}.
20834 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
20835 Seconds of inactivity before disk is suspended.
20837 Defaults to @samp{15}.
20841 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
20842 PCI Express Active State Power Management level. Alternatives are
20843 default, performance, powersave.
20845 Defaults to @samp{"performance"}.
20849 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
20850 Same as @code{pcie-aspm-ac} but on BAT mode.
20852 Defaults to @samp{"powersave"}.
20856 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
20857 Radeon graphics clock speed level. Alternatives are low, mid, high,
20860 Defaults to @samp{"high"}.
20864 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
20865 Same as @code{radeon-power-ac} but on BAT mode.
20867 Defaults to @samp{"low"}.
20871 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
20872 Radeon dynamic power management method (DPM). Alternatives are battery,
20875 Defaults to @samp{"performance"}.
20879 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
20880 Same as @code{radeon-dpm-state-ac} but on BAT mode.
20882 Defaults to @samp{"battery"}.
20886 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
20887 Radeon DPM performance level. Alternatives are auto, low, high.
20889 Defaults to @samp{"auto"}.
20893 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
20894 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
20896 Defaults to @samp{"auto"}.
20900 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
20901 Wifi power saving mode.
20903 Defaults to @samp{#f}.
20907 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
20908 Same as @code{wifi-power-ac?} but on BAT mode.
20910 Defaults to @samp{#t}.
20914 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
20915 Disable wake on LAN.
20917 Defaults to @samp{#t}.
20921 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
20922 Timeout duration in seconds before activating audio power saving on
20923 Intel HDA and AC97 devices. A value of 0 disables power saving.
20925 Defaults to @samp{0}.
20929 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
20930 Same as @code{sound-powersave-ac} but on BAT mode.
20932 Defaults to @samp{1}.
20936 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
20937 Disable controller in powersaving mode on Intel HDA devices.
20939 Defaults to @samp{#t}.
20943 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
20944 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
20945 powered on again by releasing (and reinserting) the eject lever or by
20946 pressing the disc eject button on newer models.
20948 Defaults to @samp{#f}.
20952 @deftypevr {@code{tlp-configuration} parameter} string bay-device
20953 Name of the optical drive device to power off.
20955 Defaults to @samp{"sr0"}.
20959 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
20960 Runtime Power Management for PCI(e) bus devices. Alternatives are on
20963 Defaults to @samp{"on"}.
20967 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
20968 Same as @code{runtime-pm-ac} but on BAT mode.
20970 Defaults to @samp{"auto"}.
20974 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
20975 Runtime Power Management for all PCI(e) bus devices, except blacklisted
20978 Defaults to @samp{#t}.
20982 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
20983 Exclude specified PCI(e) device addresses from Runtime Power Management.
20985 Defaults to @samp{disabled}.
20989 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
20990 Exclude PCI(e) devices assigned to the specified drivers from Runtime
20995 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
20996 Enable USB autosuspend feature.
20998 Defaults to @samp{#t}.
21002 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
21003 Exclude specified devices from USB autosuspend.
21005 Defaults to @samp{disabled}.
21009 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
21010 Exclude WWAN devices from USB autosuspend.
21012 Defaults to @samp{#t}.
21016 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
21017 Include specified devices into USB autosuspend, even if they are already
21018 excluded by the driver or via @code{usb-blacklist-wwan?}.
21020 Defaults to @samp{disabled}.
21024 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
21025 Enable USB autosuspend before shutdown.
21027 Defaults to @samp{disabled}.
21031 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
21032 Restore radio device state (bluetooth, wifi, wwan) from previous
21033 shutdown on system startup.
21035 Defaults to @samp{#f}.
21040 @cindex CPU frequency scaling with thermald
21041 @subsubheading Thermald daemon
21043 The @code{(gnu services pm)} module provides an interface to
21044 thermald, a CPU frequency scaling service which helps prevent overheating.
21046 @defvr {Scheme Variable} thermald-service-type
21047 This is the service type for
21048 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
21049 Thermal Daemon, which is responsible for controlling the thermal state
21050 of processors and preventing overheating.
21053 @deftp {Data Type} thermald-configuration
21054 Data type representing the configuration of @code{thermald-service-type}.
21057 @item @code{ignore-cpuid-check?} (default: @code{#f})
21058 Ignore cpuid check for supported CPU models.
21060 @item @code{thermald} (default: @var{thermald})
21061 Package object of thermald.
21066 @node Audio Services
21067 @subsection Audio Services
21069 The @code{(gnu services audio)} module provides a service to start MPD
21070 (the Music Player Daemon).
21073 @subsubheading Music Player Daemon
21075 The Music Player Daemon (MPD) is a service that can play music while
21076 being controlled from the local machine or over the network by a variety
21079 The following example shows how one might run @code{mpd} as user
21080 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
21083 (service mpd-service-type
21089 @defvr {Scheme Variable} mpd-service-type
21090 The service type for @command{mpd}
21093 @deftp {Data Type} mpd-configuration
21094 Data type representing the configuration of @command{mpd}.
21097 @item @code{user} (default: @code{"mpd"})
21098 The user to run mpd as.
21100 @item @code{music-dir} (default: @code{"~/Music"})
21101 The directory to scan for music files.
21103 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
21104 The directory to store playlists.
21106 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
21107 The location of the music database.
21109 @item @code{state-file} (default: @code{"~/.mpd/state"})
21110 The location of the file that stores current MPD's state.
21112 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
21113 The location of the sticker database.
21115 @item @code{port} (default: @code{"6600"})
21116 The port to run mpd on.
21118 @item @code{address} (default: @code{"any"})
21119 The address that mpd will bind to. To use a Unix domain socket,
21120 an absolute path can be specified here.
21125 @node Virtualization Services
21126 @subsection Virtualization services
21128 The @code{(gnu services virtualization)} module provides services for
21129 the libvirt and virtlog daemons, as well as other virtualization-related
21132 @subsubheading Libvirt daemon
21133 @code{libvirtd} is the server side daemon component of the libvirt
21134 virtualization management system. This daemon runs on host servers
21135 and performs required management tasks for virtualized guests.
21137 @deffn {Scheme Variable} libvirt-service-type
21138 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
21139 Its value must be a @code{libvirt-configuration}.
21142 (service libvirt-service-type
21143 (libvirt-configuration
21144 (unix-sock-group "libvirt")
21145 (tls-port "16555")))
21149 @c Auto-generated with (generate-libvirt-documentation)
21150 Available @code{libvirt-configuration} fields are:
21152 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
21157 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
21158 Flag listening for secure TLS connections on the public TCP/IP port.
21159 must set @code{listen} for this to have any effect.
21161 It is necessary to setup a CA and issue server certificates before using
21164 Defaults to @samp{#t}.
21168 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
21169 Listen for unencrypted TCP connections on the public TCP/IP port. must
21170 set @code{listen} for this to have any effect.
21172 Using the TCP socket requires SASL authentication by default. Only SASL
21173 mechanisms which support data encryption are allowed. This is
21174 DIGEST_MD5 and GSSAPI (Kerberos5)
21176 Defaults to @samp{#f}.
21180 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
21181 Port for accepting secure TLS connections This can be a port number, or
21184 Defaults to @samp{"16514"}.
21188 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
21189 Port for accepting insecure TCP connections This can be a port number,
21192 Defaults to @samp{"16509"}.
21196 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
21197 IP address or hostname used for client connections.
21199 Defaults to @samp{"0.0.0.0"}.
21203 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
21204 Flag toggling mDNS advertisement of the libvirt service.
21206 Alternatively can disable for all services on a host by stopping the
21209 Defaults to @samp{#f}.
21213 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
21214 Default mDNS advertisement name. This must be unique on the immediate
21217 Defaults to @samp{"Virtualization Host <hostname>"}.
21221 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
21222 UNIX domain socket group ownership. This can be used to allow a
21223 'trusted' set of users access to management capabilities without
21226 Defaults to @samp{"root"}.
21230 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
21231 UNIX socket permissions for the R/O socket. This is used for monitoring
21234 Defaults to @samp{"0777"}.
21238 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
21239 UNIX socket permissions for the R/W socket. Default allows only root.
21240 If PolicyKit is enabled on the socket, the default will change to allow
21241 everyone (eg, 0777)
21243 Defaults to @samp{"0770"}.
21247 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
21248 UNIX socket permissions for the admin socket. Default allows only owner
21249 (root), do not change it unless you are sure to whom you are exposing
21252 Defaults to @samp{"0777"}.
21256 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
21257 The directory in which sockets will be found/created.
21259 Defaults to @samp{"/var/run/libvirt"}.
21263 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
21264 Authentication scheme for UNIX read-only sockets. By default socket
21265 permissions allow anyone to connect
21267 Defaults to @samp{"polkit"}.
21271 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
21272 Authentication scheme for UNIX read-write sockets. By default socket
21273 permissions only allow root. If PolicyKit support was compiled into
21274 libvirt, the default will be to use 'polkit' auth.
21276 Defaults to @samp{"polkit"}.
21280 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
21281 Authentication scheme for TCP sockets. If you don't enable SASL, then
21282 all TCP traffic is cleartext. Don't do this outside of a dev/test
21285 Defaults to @samp{"sasl"}.
21289 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
21290 Authentication scheme for TLS sockets. TLS sockets already have
21291 encryption provided by the TLS layer, and limited authentication is done
21294 It is possible to make use of any SASL authentication mechanism as well,
21295 by using 'sasl' for this option
21297 Defaults to @samp{"none"}.
21301 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
21302 API access control scheme.
21304 By default an authenticated user is allowed access to all APIs. Access
21305 drivers can place restrictions on this.
21307 Defaults to @samp{()}.
21311 @deftypevr {@code{libvirt-configuration} parameter} string key-file
21312 Server key file path. If set to an empty string, then no private key is
21315 Defaults to @samp{""}.
21319 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
21320 Server key file path. If set to an empty string, then no certificate is
21323 Defaults to @samp{""}.
21327 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
21328 Server key file path. If set to an empty string, then no CA certificate
21331 Defaults to @samp{""}.
21335 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
21336 Certificate revocation list path. If set to an empty string, then no
21339 Defaults to @samp{""}.
21343 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
21344 Disable verification of our own server certificates.
21346 When libvirtd starts it performs some sanity checks against its own
21349 Defaults to @samp{#f}.
21353 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
21354 Disable verification of client certificates.
21356 Client certificate verification is the primary authentication mechanism.
21357 Any client which does not present a certificate signed by the CA will be
21360 Defaults to @samp{#f}.
21364 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
21365 Whitelist of allowed x509 Distinguished Name.
21367 Defaults to @samp{()}.
21371 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
21372 Whitelist of allowed SASL usernames. The format for username depends on
21373 the SASL authentication mechanism.
21375 Defaults to @samp{()}.
21379 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
21380 Override the compile time default TLS priority string. The default is
21381 usually "NORMAL" unless overridden at build time. Only set this is it
21382 is desired for libvirt to deviate from the global default settings.
21384 Defaults to @samp{"NORMAL"}.
21388 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
21389 Maximum number of concurrent client connections to allow over all
21392 Defaults to @samp{5000}.
21396 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
21397 Maximum length of queue of connections waiting to be accepted by the
21398 daemon. Note, that some protocols supporting retransmission may obey
21399 this so that a later reattempt at connection succeeds.
21401 Defaults to @samp{1000}.
21405 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
21406 Maximum length of queue of accepted but not yet authenticated clients.
21407 Set this to zero to turn this feature off
21409 Defaults to @samp{20}.
21413 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
21414 Number of workers to start up initially.
21416 Defaults to @samp{5}.
21420 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
21421 Maximum number of worker threads.
21423 If the number of active clients exceeds @code{min-workers}, then more
21424 threads are spawned, up to max_workers limit. Typically you'd want
21425 max_workers to equal maximum number of clients allowed.
21427 Defaults to @samp{20}.
21431 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
21432 Number of priority workers. If all workers from above pool are stuck,
21433 some calls marked as high priority (notably domainDestroy) can be
21434 executed in this pool.
21436 Defaults to @samp{5}.
21440 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
21441 Total global limit on concurrent RPC calls.
21443 Defaults to @samp{20}.
21447 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
21448 Limit on concurrent requests from a single client connection. To avoid
21449 one client monopolizing the server this should be a small fraction of
21450 the global max_requests and max_workers parameter.
21452 Defaults to @samp{5}.
21456 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
21457 Same as @code{min-workers} but for the admin interface.
21459 Defaults to @samp{1}.
21463 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
21464 Same as @code{max-workers} but for the admin interface.
21466 Defaults to @samp{5}.
21470 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
21471 Same as @code{max-clients} but for the admin interface.
21473 Defaults to @samp{5}.
21477 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
21478 Same as @code{max-queued-clients} but for the admin interface.
21480 Defaults to @samp{5}.
21484 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
21485 Same as @code{max-client-requests} but for the admin interface.
21487 Defaults to @samp{5}.
21491 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
21492 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
21494 Defaults to @samp{3}.
21498 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
21501 A filter allows to select a different logging level for a given category
21502 of logs The format for a filter is one of:
21513 where @code{name} is a string which is matched against the category
21514 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
21515 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
21516 be a substring of the full category name, in order to match multiple
21517 similar categories), the optional "+" prefix tells libvirt to log stack
21518 trace for each message matching name, and @code{x} is the minimal level
21519 where matching messages should be logged:
21536 Multiple filters can be defined in a single filters statement, they just
21537 need to be separated by spaces.
21539 Defaults to @samp{"3:remote 4:event"}.
21543 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
21546 An output is one of the places to save logging information The format
21547 for an output can be:
21551 output goes to stderr
21553 @item x:syslog:name
21554 use syslog for the output and use the given name as the ident
21556 @item x:file:file_path
21557 output to a file, with the given filepath
21560 output to journald logging system
21564 In all case the x prefix is the minimal level, acting as a filter
21581 Multiple outputs can be defined, they just need to be separated by
21584 Defaults to @samp{"3:stderr"}.
21588 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
21589 Allows usage of the auditing subsystem to be altered
21593 0: disable all auditing
21596 1: enable auditing, only if enabled on host
21599 2: enable auditing, and exit if disabled on host.
21603 Defaults to @samp{1}.
21607 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
21608 Send audit messages via libvirt logging infrastructure.
21610 Defaults to @samp{#f}.
21614 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
21615 Host UUID. UUID must not have all digits be the same.
21617 Defaults to @samp{""}.
21621 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
21622 Source to read host UUID.
21626 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
21629 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
21633 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
21636 Defaults to @samp{"smbios"}.
21640 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
21641 A keepalive message is sent to a client after @code{keepalive_interval}
21642 seconds of inactivity to check if the client is still responding. If
21643 set to -1, libvirtd will never send keepalive requests; however clients
21644 can still send them and the daemon will send responses.
21646 Defaults to @samp{5}.
21650 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
21651 Maximum number of keepalive messages that are allowed to be sent to the
21652 client without getting any response before the connection is considered
21655 In other words, the connection is automatically closed approximately
21656 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
21657 the last message received from the client. When @code{keepalive-count}
21658 is set to 0, connections will be automatically closed after
21659 @code{keepalive-interval} seconds of inactivity without sending any
21660 keepalive messages.
21662 Defaults to @samp{5}.
21666 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
21667 Same as above but for admin interface.
21669 Defaults to @samp{5}.
21673 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
21674 Same as above but for admin interface.
21676 Defaults to @samp{5}.
21680 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
21681 Timeout for Open vSwitch calls.
21683 The @code{ovs-vsctl} utility is used for the configuration and its
21684 timeout option is set by default to 5 seconds to avoid potential
21685 infinite waits blocking libvirt.
21687 Defaults to @samp{5}.
21691 @c %end of autogenerated docs
21693 @subsubheading Virtlog daemon
21694 The virtlogd service is a server side daemon component of libvirt that is
21695 used to manage logs from virtual machine consoles.
21697 This daemon is not used directly by libvirt client applications, rather it
21698 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
21699 standalone daemon, the main @code{libvirtd} daemon can be restarted without
21700 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
21701 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
21703 @deffn {Scheme Variable} virtlog-service-type
21704 This is the type of the virtlog daemon.
21705 Its value must be a @code{virtlog-configuration}.
21708 (service virtlog-service-type
21709 (virtlog-configuration
21710 (max-clients 1000)))
21714 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
21715 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
21717 Defaults to @samp{3}.
21721 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
21724 A filter allows to select a different logging level for a given category
21725 of logs The format for a filter is one of:
21736 where @code{name} is a string which is matched against the category
21737 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
21738 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
21739 be a substring of the full category name, in order to match multiple
21740 similar categories), the optional "+" prefix tells libvirt to log stack
21741 trace for each message matching name, and @code{x} is the minimal level
21742 where matching messages should be logged:
21759 Multiple filters can be defined in a single filters statement, they just
21760 need to be separated by spaces.
21762 Defaults to @samp{"3:remote 4:event"}.
21766 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
21769 An output is one of the places to save logging information The format
21770 for an output can be:
21774 output goes to stderr
21776 @item x:syslog:name
21777 use syslog for the output and use the given name as the ident
21779 @item x:file:file_path
21780 output to a file, with the given filepath
21783 output to journald logging system
21787 In all case the x prefix is the minimal level, acting as a filter
21804 Multiple outputs can be defined, they just need to be separated by
21807 Defaults to @samp{"3:stderr"}.
21811 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
21812 Maximum number of concurrent client connections to allow over all
21815 Defaults to @samp{1024}.
21819 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
21820 Maximum file size before rolling over.
21822 Defaults to @samp{2MB}
21826 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
21827 Maximum number of backup files to keep.
21829 Defaults to @samp{3}
21833 @subsubheading Transparent Emulation with QEMU
21836 @cindex @code{binfmt_misc}
21837 @code{qemu-binfmt-service-type} provides support for transparent
21838 emulation of program binaries built for different architectures---e.g.,
21839 it allows you to transparently execute an ARMv7 program on an x86_64
21840 machine. It achieves this by combining the @uref{https://www.qemu.org,
21841 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
21843 @defvr {Scheme Variable} qemu-binfmt-service-type
21844 This is the type of the QEMU/binfmt service for transparent emulation.
21845 Its value must be a @code{qemu-binfmt-configuration} object, which
21846 specifies the QEMU package to use as well as the architecture we want to
21850 (service qemu-binfmt-service-type
21851 (qemu-binfmt-configuration
21852 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
21855 In this example, we enable transparent emulation for the ARM and aarch64
21856 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
21857 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
21858 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
21861 @deftp {Data Type} qemu-binfmt-configuration
21862 This is the configuration for the @code{qemu-binfmt} service.
21865 @item @code{platforms} (default: @code{'()})
21866 The list of emulated QEMU platforms. Each item must be a @dfn{platform
21867 object} as returned by @code{lookup-qemu-platforms} (see below).
21869 @item @code{guix-support?} (default: @code{#f})
21870 When it is true, QEMU and all its dependencies are added to the build
21871 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
21872 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
21873 handlers to be used within the build environment, which in turn means
21874 that you can transparently build programs for another architecture.
21876 For example, let's suppose you're on an x86_64 machine and you have this
21880 (service qemu-binfmt-service-type
21881 (qemu-binfmt-configuration
21882 (platforms (lookup-qemu-platforms "arm"))
21883 (guix-support? #t)))
21889 guix build -s armhf-linux inkscape
21893 and it will build Inkscape for ARMv7 @emph{as if it were a native
21894 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
21895 if you'd like to test a package build for an architecture you don't have
21898 @item @code{qemu} (default: @code{qemu})
21899 The QEMU package to use.
21903 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
21904 Return the list of QEMU platform objects corresponding to
21905 @var{platforms}@dots{}. @var{platforms} must be a list of strings
21906 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
21907 @code{"mips64el"}, and so on.
21910 @deffn {Scheme Procedure} qemu-platform? @var{obj}
21911 Return true if @var{obj} is a platform object.
21914 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
21915 Return the name of @var{platform}---a string such as @code{"arm"}.
21918 @node Version Control Services
21919 @subsection Version Control Services
21921 The @code{(gnu services version-control)} module provides a service to
21922 allow remote access to local Git repositories. There are three options:
21923 the @code{git-daemon-service}, which provides access to repositories via
21924 the @code{git://} unsecured TCP-based protocol, extending the
21925 @code{nginx} web server to proxy some requests to
21926 @code{git-http-backend}, or providing a web interface with
21927 @code{cgit-service-type}.
21929 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
21931 Return a service that runs @command{git daemon}, a simple TCP server to
21932 expose repositories over the Git protocol for anonymous access.
21934 The optional @var{config} argument should be a
21935 @code{<git-daemon-configuration>} object, by default it allows read-only
21936 access to exported@footnote{By creating the magic file
21937 "git-daemon-export-ok" in the repository directory.} repositories under
21942 @deftp {Data Type} git-daemon-configuration
21943 Data type representing the configuration for @code{git-daemon-service}.
21946 @item @code{package} (default: @var{git})
21947 Package object of the Git distributed version control system.
21949 @item @code{export-all?} (default: @var{#f})
21950 Whether to allow access for all Git repositories, even if they do not
21951 have the @file{git-daemon-export-ok} file.
21953 @item @code{base-path} (default: @file{/srv/git})
21954 Whether to remap all the path requests as relative to the given path.
21955 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
21956 then if you later try to pull @code{git://example.com/hello.git}, git
21957 daemon will interpret the path as @code{/srv/git/hello.git}.
21959 @item @code{user-path} (default: @var{#f})
21960 Whether to allow @code{~user} notation to be used in requests. When
21961 specified with empty string, requests to @code{git://host/~alice/foo} is
21962 taken as a request to access @code{foo} repository in the home directory
21963 of user @code{alice}. If @var{(user-path "path")} is specified, the
21964 same request is taken as a request to access @code{path/foo} repository
21965 in the home directory of user @code{alice}.
21967 @item @code{listen} (default: @var{'()})
21968 Whether to listen on specific IP addresses or hostnames, defaults to
21971 @item @code{port} (default: @var{#f})
21972 Whether to listen on an alternative port, which defaults to 9418.
21974 @item @code{whitelist} (default: @var{'()})
21975 If not empty, only allow access to this list of directories.
21977 @item @code{extra-options} (default: @var{'()})
21978 Extra options will be passed to @code{git daemon}, please run
21979 @command{man git-daemon} for more information.
21984 The @code{git://} protocol lacks authentication. When you pull from a
21985 repository fetched via @code{git://}, you don't know that the data you
21986 receive was modified is really coming from the specified host, and you
21987 have your connection is subject to eavesdropping. It's better to use an
21988 authenticated and encrypted transport, such as @code{https}. Although Git allows you
21989 to serve repositories using unsophisticated file-based web servers,
21990 there is a faster protocol implemented by the @code{git-http-backend}
21991 program. This program is the back-end of a proper Git web service. It
21992 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
21993 on running the necessary @code{fcgiwrap} daemon.
21995 Guix has a separate configuration data type for serving Git repositories
21998 @deftp {Data Type} git-http-configuration
21999 Data type representing the configuration for @code{git-http-service}.
22002 @item @code{package} (default: @var{git})
22003 Package object of the Git distributed version control system.
22005 @item @code{git-root} (default: @file{/srv/git})
22006 Directory containing the Git repositories to expose to the world.
22008 @item @code{export-all?} (default: @var{#f})
22009 Whether to expose access for all Git repositories in @var{git-root},
22010 even if they do not have the @file{git-daemon-export-ok} file.
22012 @item @code{uri-path} (default: @file{/git/})
22013 Path prefix for Git access. With the default @code{/git/} prefix, this
22014 will map @code{http://@var{server}/git/@var{repo}.git} to
22015 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
22016 with this prefix are not passed on to this Git instance.
22018 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
22019 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
22024 There is no @code{git-http-service-type}, currently; instead you can
22025 create an @code{nginx-location-configuration} from a
22026 @code{git-http-configuration} and then add that location to a web
22029 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
22030 [config=(git-http-configuration)]
22031 Compute an @code{nginx-location-configuration} that corresponds to the
22032 given Git http configuration. An example nginx service definition to
22033 serve the default @file{/srv/git} over HTTPS might be:
22036 (service nginx-service-type
22037 (nginx-configuration
22040 (nginx-server-configuration
22041 (listen '("443 ssl"))
22042 (server-name "git.my-host.org")
22044 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
22045 (ssl-certificate-key
22046 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
22049 (git-http-nginx-location-configuration
22050 (git-http-configuration (uri-path "/"))))))))))
22053 This example assumes that you are using Let's Encrypt to get your TLS
22054 certificate. @xref{Certificate Services}. The default @code{certbot}
22055 service will redirect all HTTP traffic on @code{git.my-host.org} to
22056 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
22057 system services. @xref{Web Services}.
22060 @subsubheading Cgit Service
22062 @cindex Cgit service
22063 @cindex Git, web interface
22064 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
22065 repositories written in C.
22067 The following example will configure the service with default values.
22068 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
22071 (service cgit-service-type)
22074 The @code{file-object} type designates either a file-like object
22075 (@pxref{G-Expressions, file-like objects}) or a string.
22077 @c %start of fragment
22079 Available @code{cgit-configuration} fields are:
22081 @deftypevr {@code{cgit-configuration} parameter} package package
22086 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
22087 NGINX configuration.
22091 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
22092 Specifies a command which will be invoked to format the content of about
22093 pages (both top-level and for each repository).
22095 Defaults to @samp{""}.
22099 @deftypevr {@code{cgit-configuration} parameter} string agefile
22100 Specifies a path, relative to each repository path, which can be used to
22101 specify the date and time of the youngest commit in the repository.
22103 Defaults to @samp{""}.
22107 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
22108 Specifies a command that will be invoked for authenticating repository
22111 Defaults to @samp{""}.
22115 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
22116 Flag which, when set to @samp{age}, enables date ordering in the branch
22117 ref list, and when set @samp{name} enables ordering by branch name.
22119 Defaults to @samp{"name"}.
22123 @deftypevr {@code{cgit-configuration} parameter} string cache-root
22124 Path used to store the cgit cache entries.
22126 Defaults to @samp{"/var/cache/cgit"}.
22130 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
22131 Number which specifies the time-to-live, in minutes, for the cached
22132 version of repository pages accessed with a fixed SHA1.
22134 Defaults to @samp{-1}.
22138 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
22139 Number which specifies the time-to-live, in minutes, for the cached
22140 version of repository pages accessed without a fixed SHA1.
22142 Defaults to @samp{5}.
22146 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
22147 Number which specifies the time-to-live, in minutes, for the cached
22148 version of the repository summary page.
22150 Defaults to @samp{5}.
22154 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
22155 Number which specifies the time-to-live, in minutes, for the cached
22156 version of the repository index page.
22158 Defaults to @samp{5}.
22162 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
22163 Number which specifies the time-to-live, in minutes, for the result of
22164 scanning a path for Git repositories.
22166 Defaults to @samp{15}.
22170 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
22171 Number which specifies the time-to-live, in minutes, for the cached
22172 version of the repository about page.
22174 Defaults to @samp{15}.
22178 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
22179 Number which specifies the time-to-live, in minutes, for the cached
22180 version of snapshots.
22182 Defaults to @samp{5}.
22186 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
22187 The maximum number of entries in the cgit cache. When set to @samp{0},
22188 caching is disabled.
22190 Defaults to @samp{0}.
22194 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
22195 Sort items in the repo list case sensitively.
22197 Defaults to @samp{#t}.
22201 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
22202 List of common prefixes which, when combined with a repository URL,
22203 generates valid clone URLs for the repository.
22205 Defaults to @samp{()}.
22209 @deftypevr {@code{cgit-configuration} parameter} list clone-url
22210 List of @code{clone-url} templates.
22212 Defaults to @samp{()}.
22216 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
22217 Command which will be invoked to format commit messages.
22219 Defaults to @samp{""}.
22223 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
22224 Flag which, when set to @samp{date}, enables strict date ordering in the
22225 commit log, and when set to @samp{topo} enables strict topological
22228 Defaults to @samp{"git log"}.
22232 @deftypevr {@code{cgit-configuration} parameter} file-object css
22233 URL which specifies the css document to include in all cgit pages.
22235 Defaults to @samp{"/share/cgit/cgit.css"}.
22239 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
22240 Specifies a command which will be invoked to format names and email
22241 address of committers, authors, and taggers, as represented in various
22242 places throughout the cgit interface.
22244 Defaults to @samp{""}.
22248 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
22249 Flag which, when set to @samp{#t}, will make cgit generate a HTML
22250 fragment suitable for embedding in other HTML pages.
22252 Defaults to @samp{#f}.
22256 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
22257 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
22258 commit history graph to the left of the commit messages in the
22259 repository log page.
22261 Defaults to @samp{#f}.
22265 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
22266 Flag which, when set to @samp{#t}, allows all filter settings to be
22267 overridden in repository-specific cgitrc files.
22269 Defaults to @samp{#f}.
22273 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
22274 Flag which, when set to @samp{#t}, allows users to follow a file in the
22277 Defaults to @samp{#f}.
22281 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
22282 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
22285 Defaults to @samp{#t}.
22289 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
22290 Flag which, when set to @samp{#t}, will make cgit generate extra links
22291 "summary", "commit", "tree" for each repo in the repository index.
22293 Defaults to @samp{#f}.
22297 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
22298 Flag which, when set to @samp{#t}, will make cgit display the owner of
22299 each repo in the repository index.
22301 Defaults to @samp{#t}.
22305 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
22306 Flag which, when set to @samp{#t}, will make cgit print the number of
22307 modified files for each commit on the repository log page.
22309 Defaults to @samp{#f}.
22313 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
22314 Flag which, when set to @samp{#t}, will make cgit print the number of
22315 added and removed lines for each commit on the repository log page.
22317 Defaults to @samp{#f}.
22321 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
22322 Flag which, when set to @code{#t}, will make cgit display remote
22323 branches in the summary and refs views.
22325 Defaults to @samp{#f}.
22329 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
22330 Flag which, when set to @code{1}, will make cgit use the subject of the
22331 parent commit as link text when generating links to parent commits in
22334 Defaults to @samp{#f}.
22338 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
22339 Flag which, when set to @samp{#t}, will make cgit use the subject of the
22340 parent commit as link text when generating links to parent commits in
22343 Defaults to @samp{#f}.
22347 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
22348 Flag which, when set to @samp{#t}, will make cgit generate linenumber
22349 links for plaintext blobs printed in the tree view.
22351 Defaults to @samp{#t}.
22355 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
22356 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
22357 set any repo specific settings.
22359 Defaults to @samp{#f}.
22363 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
22364 URL used as link to a shortcut icon for cgit.
22366 Defaults to @samp{"/favicon.ico"}.
22370 @deftypevr {@code{cgit-configuration} parameter} string footer
22371 The content of the file specified with this option will be included
22372 verbatim at the bottom of all pages (i.e.@: it replaces the standard
22373 "generated by..."@: message).
22375 Defaults to @samp{""}.
22379 @deftypevr {@code{cgit-configuration} parameter} string head-include
22380 The content of the file specified with this option will be included
22381 verbatim in the HTML HEAD section on all pages.
22383 Defaults to @samp{""}.
22387 @deftypevr {@code{cgit-configuration} parameter} string header
22388 The content of the file specified with this option will be included
22389 verbatim at the top of all pages.
22391 Defaults to @samp{""}.
22395 @deftypevr {@code{cgit-configuration} parameter} file-object include
22396 Name of a configfile to include before the rest of the current config-
22399 Defaults to @samp{""}.
22403 @deftypevr {@code{cgit-configuration} parameter} string index-header
22404 The content of the file specified with this option will be included
22405 verbatim above the repository index.
22407 Defaults to @samp{""}.
22411 @deftypevr {@code{cgit-configuration} parameter} string index-info
22412 The content of the file specified with this option will be included
22413 verbatim below the heading on the repository index page.
22415 Defaults to @samp{""}.
22419 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
22420 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
22421 in the servers timezone.
22423 Defaults to @samp{#f}.
22427 @deftypevr {@code{cgit-configuration} parameter} file-object logo
22428 URL which specifies the source of an image which will be used as a logo
22431 Defaults to @samp{"/share/cgit/cgit.png"}.
22435 @deftypevr {@code{cgit-configuration} parameter} string logo-link
22436 URL loaded when clicking on the cgit logo image.
22438 Defaults to @samp{""}.
22442 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
22443 Command which will be invoked to format the Owner column of the main
22446 Defaults to @samp{""}.
22450 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
22451 Number of items to display in atom feeds view.
22453 Defaults to @samp{10}.
22457 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
22458 Number of entries to list per page in "log" view.
22460 Defaults to @samp{50}.
22464 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
22465 Number of commit message characters to display in "log" view.
22467 Defaults to @samp{80}.
22471 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
22472 Specifies the number of entries to list per page on the repository index
22475 Defaults to @samp{50}.
22479 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
22480 Specifies the maximum number of repo description characters to display
22481 on the repository index page.
22483 Defaults to @samp{80}.
22487 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
22488 Specifies the maximum size of a blob to display HTML for in KBytes.
22490 Defaults to @samp{0}.
22494 @deftypevr {@code{cgit-configuration} parameter} string max-stats
22495 Maximum statistics period. Valid values are @samp{week},@samp{month},
22496 @samp{quarter} and @samp{year}.
22498 Defaults to @samp{""}.
22502 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
22503 Mimetype for the specified filename extension.
22505 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
22506 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
22507 "image/png") (svg "image/svg+xml"))}.
22511 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
22512 Specifies the file to use for automatic mimetype lookup.
22514 Defaults to @samp{""}.
22518 @deftypevr {@code{cgit-configuration} parameter} string module-link
22519 Text which will be used as the formatstring for a hyperlink when a
22520 submodule is printed in a directory listing.
22522 Defaults to @samp{""}.
22526 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
22527 If set to the value @samp{#t} caching will be disabled.
22529 Defaults to @samp{#f}.
22533 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
22534 If set to @samp{#t} showing full author email addresses will be
22537 Defaults to @samp{#f}.
22541 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
22542 Flag which, when set to @samp{#t}, will make cgit omit the standard
22543 header on all pages.
22545 Defaults to @samp{#f}.
22549 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
22550 A list of subdirectories inside of @code{repository-directory}, relative
22551 to it, that should loaded as Git repositories. An empty list means that
22552 all subdirectories will be loaded.
22554 Defaults to @samp{()}.
22558 @deftypevr {@code{cgit-configuration} parameter} file-object readme
22559 Text which will be used as default value for @code{cgit-repo-readme}.
22561 Defaults to @samp{""}.
22565 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
22566 If set to @code{#t} and @code{repository-directory} is enabled, if any
22567 repositories are found with a suffix of @code{.git}, this suffix will be
22568 removed for the URL and name.
22570 Defaults to @samp{#f}.
22574 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
22575 Maximum number of files to consider when detecting renames.
22577 Defaults to @samp{-1}.
22581 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
22582 The way in which repositories in each section are sorted.
22584 Defaults to @samp{""}.
22588 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
22589 Text used as content for the @code{robots} meta-tag.
22591 Defaults to @samp{("noindex" "nofollow")}.
22595 @deftypevr {@code{cgit-configuration} parameter} string root-desc
22596 Text printed below the heading on the repository index page.
22598 Defaults to @samp{"a fast webinterface for the git dscm"}.
22602 @deftypevr {@code{cgit-configuration} parameter} string root-readme
22603 The content of the file specified with this option will be included
22604 verbatim below thef "about" link on the repository index page.
22606 Defaults to @samp{""}.
22610 @deftypevr {@code{cgit-configuration} parameter} string root-title
22611 Text printed as heading on the repository index page.
22613 Defaults to @samp{""}.
22617 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
22618 If set to @samp{#t} and repository-directory is enabled,
22619 repository-directory will recurse into directories whose name starts
22620 with a period. Otherwise, repository-directory will stay away from such
22621 directories, considered as "hidden". Note that this does not apply to
22622 the ".git" directory in non-bare repos.
22624 Defaults to @samp{#f}.
22628 @deftypevr {@code{cgit-configuration} parameter} list snapshots
22629 Text which specifies the default set of snapshot formats that cgit
22630 generates links for.
22632 Defaults to @samp{()}.
22636 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
22637 Name of the directory to scan for repositories (represents
22640 Defaults to @samp{"/srv/git"}.
22644 @deftypevr {@code{cgit-configuration} parameter} string section
22645 The name of the current repository section - all repositories defined
22646 after this option will inherit the current section name.
22648 Defaults to @samp{""}.
22652 @deftypevr {@code{cgit-configuration} parameter} string section-sort
22653 Flag which, when set to @samp{1}, will sort the sections on the
22654 repository listing by name.
22656 Defaults to @samp{""}.
22660 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
22661 A number which, if defined prior to repository-directory, specifies how
22662 many path elements from each repo path to use as a default section name.
22664 Defaults to @samp{0}.
22668 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
22669 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
22672 Defaults to @samp{#f}.
22676 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
22677 Specifies a command which will be invoked to format plaintext blobs in
22680 Defaults to @samp{""}.
22684 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
22685 Specifies the number of branches to display in the repository "summary"
22688 Defaults to @samp{10}.
22692 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
22693 Specifies the number of log entries to display in the repository
22696 Defaults to @samp{10}.
22700 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
22701 Specifies the number of tags to display in the repository "summary"
22704 Defaults to @samp{10}.
22708 @deftypevr {@code{cgit-configuration} parameter} string strict-export
22709 Filename which, if specified, needs to be present within the repository
22710 for cgit to allow access to that repository.
22712 Defaults to @samp{""}.
22716 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
22717 URL which, if specified, will be used as root for all cgit links.
22719 Defaults to @samp{"/"}.
22723 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
22724 A list of @dfn{cgit-repo} records to use with config.
22726 Defaults to @samp{()}.
22728 Available @code{repository-cgit-configuration} fields are:
22730 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
22731 A mask of snapshot formats for this repo that cgit generates links for,
22732 restricted by the global @code{snapshots} setting.
22734 Defaults to @samp{()}.
22738 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
22739 Override the default @code{source-filter}.
22741 Defaults to @samp{""}.
22745 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
22746 The relative URL used to access the repository.
22748 Defaults to @samp{""}.
22752 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
22753 Override the default @code{about-filter}.
22755 Defaults to @samp{""}.
22759 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
22760 Flag which, when set to @samp{age}, enables date ordering in the branch
22761 ref list, and when set to @samp{name} enables ordering by branch name.
22763 Defaults to @samp{""}.
22767 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
22768 A list of URLs which can be used to clone repo.
22770 Defaults to @samp{()}.
22774 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
22775 Override the default @code{commit-filter}.
22777 Defaults to @samp{""}.
22781 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
22782 Flag which, when set to @samp{date}, enables strict date ordering in the
22783 commit log, and when set to @samp{topo} enables strict topological
22786 Defaults to @samp{""}.
22790 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
22791 The name of the default branch for this repository. If no such branch
22792 exists in the repository, the first branch name (when sorted) is used as
22793 default instead. By default branch pointed to by HEAD, or "master" if
22794 there is no suitable HEAD.
22796 Defaults to @samp{""}.
22800 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
22801 The value to show as repository description.
22803 Defaults to @samp{""}.
22807 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
22808 The value to show as repository homepage.
22810 Defaults to @samp{""}.
22814 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
22815 Override the default @code{email-filter}.
22817 Defaults to @samp{""}.
22821 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
22822 A flag which can be used to disable the global setting
22823 @code{enable-commit-graph?}.
22825 Defaults to @samp{disabled}.
22829 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
22830 A flag which can be used to disable the global setting
22831 @code{enable-log-filecount?}.
22833 Defaults to @samp{disabled}.
22837 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
22838 A flag which can be used to disable the global setting
22839 @code{enable-log-linecount?}.
22841 Defaults to @samp{disabled}.
22845 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
22846 Flag which, when set to @code{#t}, will make cgit display remote
22847 branches in the summary and refs views.
22849 Defaults to @samp{disabled}.
22853 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
22854 A flag which can be used to override the global setting
22855 @code{enable-subject-links?}.
22857 Defaults to @samp{disabled}.
22861 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
22862 A flag which can be used to override the global setting
22863 @code{enable-html-serving?}.
22865 Defaults to @samp{disabled}.
22869 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
22870 Flag which, when set to @code{#t}, hides the repository from the
22873 Defaults to @samp{#f}.
22877 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
22878 Flag which, when set to @samp{#t}, ignores the repository.
22880 Defaults to @samp{#f}.
22884 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
22885 URL which specifies the source of an image which will be used as a logo
22886 on this repo’s pages.
22888 Defaults to @samp{""}.
22892 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
22893 URL loaded when clicking on the cgit logo image.
22895 Defaults to @samp{""}.
22899 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
22900 Override the default @code{owner-filter}.
22902 Defaults to @samp{""}.
22906 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
22907 Text which will be used as the formatstring for a hyperlink when a
22908 submodule is printed in a directory listing. The arguments for the
22909 formatstring are the path and SHA1 of the submodule commit.
22911 Defaults to @samp{""}.
22915 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
22916 Text which will be used as the formatstring for a hyperlink when a
22917 submodule with the specified subdirectory path is printed in a directory
22920 Defaults to @samp{()}.
22924 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
22925 Override the default maximum statistics period.
22927 Defaults to @samp{""}.
22931 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
22932 The value to show as repository name.
22934 Defaults to @samp{""}.
22938 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
22939 A value used to identify the owner of the repository.
22941 Defaults to @samp{""}.
22945 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
22946 An absolute path to the repository directory.
22948 Defaults to @samp{""}.
22952 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
22953 A path (relative to repo) which specifies a file to include verbatim as
22954 the "About" page for this repo.
22956 Defaults to @samp{""}.
22960 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
22961 The name of the current repository section - all repositories defined
22962 after this option will inherit the current section name.
22964 Defaults to @samp{""}.
22968 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
22969 Extra options will be appended to cgitrc file.
22971 Defaults to @samp{()}.
22977 @deftypevr {@code{cgit-configuration} parameter} list extra-options
22978 Extra options will be appended to cgitrc file.
22980 Defaults to @samp{()}.
22985 @c %end of fragment
22987 However, it could be that you just want to get a @code{cgitrc} up and
22988 running. In that case, you can pass an @code{opaque-cgit-configuration}
22989 as a record to @code{cgit-service-type}. As its name indicates, an
22990 opaque configuration does not have easy reflective capabilities.
22992 Available @code{opaque-cgit-configuration} fields are:
22994 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
22998 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
22999 The contents of the @code{cgitrc}, as a string.
23002 For example, if your @code{cgitrc} is just the empty string, you
23003 could instantiate a cgit service like this:
23006 (service cgit-service-type
23007 (opaque-cgit-configuration
23011 @subsubheading Gitolite Service
23013 @cindex Gitolite service
23014 @cindex Git, hosting
23015 @uref{http://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
23016 repositories on a central server.
23018 Gitolite can handle multiple repositories and users, and supports flexible
23019 configuration of the permissions for the users on the repositories.
23021 The following example will configure Gitolite using the default @code{git}
23022 user, and the provided SSH public key.
23025 (service gitolite-service-type
23026 (gitolite-configuration
23027 (admin-pubkey (plain-file
23029 "ssh-rsa AAAA... guix@@example.com"))))
23032 Gitolite is configured through a special admin repository which you can clone,
23033 for example, if you setup Gitolite on @code{example.com}, you would run the
23034 following command to clone the admin repository.
23037 git clone git@@example.com:gitolite-admin
23040 When the Gitolite service is activated, the provided @code{admin-pubkey} will
23041 be inserted in to the @file{keydir} directory in the gitolite-admin
23042 repository. If this results in a change in the repository, it will be
23043 committed using the message ``gitolite setup by GNU Guix''.
23045 @deftp {Data Type} gitolite-configuration
23046 Data type representing the configuration for @code{gitolite-service-type}.
23049 @item @code{package} (default: @var{gitolite})
23050 Gitolite package to use.
23052 @item @code{user} (default: @var{git})
23053 User to use for Gitolite. This will be user that you use when accessing
23056 @item @code{group} (default: @var{git})
23057 Group to use for Gitolite.
23059 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
23060 Directory in which to store the Gitolite configuration and repositories.
23062 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
23063 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
23064 representing the configuration for Gitolite.
23066 @item @code{admin-pubkey} (default: @var{#f})
23067 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
23068 setup Gitolite. This will be inserted in to the @file{keydir} directory
23069 within the gitolite-admin repository.
23071 To specify the SSH key as a string, use the @code{plain-file} function.
23074 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
23080 @deftp {Data Type} gitolite-rc-file
23081 Data type representing the Gitolite RC file.
23084 @item @code{umask} (default: @code{#o0077})
23085 This controls the permissions Gitolite sets on the repositories and their
23088 A value like @code{#o0027} will give read access to the group used by Gitolite
23089 (by default: @code{git}). This is necessary when using Gitolite with software
23090 like cgit or gitweb.
23092 @item @code{git-config-keys} (default: @code{""})
23093 Gitolite allows you to set git config values using the "config" keyword. This
23094 setting allows control over the config keys to accept.
23096 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
23097 Set the role names allowed to be used by users running the perms command.
23099 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
23100 This setting controls the commands and features to enable within Gitolite.
23106 @node Game Services
23107 @subsection Game Services
23109 @subsubheading The Battle for Wesnoth Service
23111 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
23112 based tactical strategy game, with several single player campaigns, and
23113 multiplayer games (both networked and local).
23115 @defvar {Scheme Variable} wesnothd-service-type
23116 Service type for the wesnothd service. Its value must be a
23117 @code{wesnothd-configuration} object. To run wesnothd in the default
23118 configuration, instantiate it as:
23121 (service wesnothd-service-type)
23125 @deftp {Data Type} wesnothd-configuration
23126 Data type representing the configuration of @command{wesnothd}.
23129 @item @code{package} (default: @code{wesnoth-server})
23130 The wesnoth server package to use.
23132 @item @code{port} (default: @code{15000})
23133 The port to bind the server to.
23137 @node Miscellaneous Services
23138 @subsection Miscellaneous Services
23140 @cindex fingerprint
23141 @subsubheading Fingerprint Service
23143 The @code{(gnu services fingerprint)} module provides a DBus service to
23144 read and identify fingerprints via a fingerprint sensor.
23146 @defvr {Scheme Variable} fprintd-service-type
23147 The service type for @command{fprintd}, which provides the fingerprint
23148 reading capability.
23151 (service fprintd-service-type)
23156 @subsubheading System Control Service
23158 The @code{(gnu services sysctl)} provides a service to configure kernel
23159 parameters at boot.
23161 @defvr {Scheme Variable} sysctl-service-type
23162 The service type for @command{sysctl}, which modifies kernel parameters
23163 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
23167 (service sysctl-service-type
23168 (sysctl-configuration
23169 (settings '(("net.ipv4.ip_forward" . "1")))))
23173 @deftp {Data Type} sysctl-configuration
23174 The data type representing the configuration of @command{sysctl}.
23177 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
23178 The @command{sysctl} executable to use.
23180 @item @code{settings} (default: @code{'()})
23181 An association list specifies kernel parameters and their values.
23186 @subsubheading PC/SC Smart Card Daemon Service
23188 The @code{(gnu services security-token)} module provides the following service
23189 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
23190 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
23191 manager that coordinates communications with smart card readers, smart cards
23192 and cryptographic tokens that are connected to the system.
23194 @defvr {Scheme Variable} pcscd-service-type
23195 Service type for the @command{pcscd} service. Its value must be a
23196 @code{pcscd-configuration} object. To run pcscd in the default
23197 configuration, instantiate it as:
23200 (service pcscd-service-type)
23204 @deftp {Data Type} pcscd-configuration
23205 The data type representing the configuration of @command{pcscd}.
23208 @item @code{pcsc-lite} (default: @code{pcsc-lite})
23209 The pcsc-lite package that provides pcscd.
23210 @item @code{usb-drivers} (default: @code{(list ccid)})
23211 List of packages that provide USB drivers to pcscd. Drivers are expected to be
23212 under @file{pcsc/drivers} in the store directory of the package.
23217 @subsubheading Lirc Service
23219 The @code{(gnu services lirc)} module provides the following service.
23221 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
23222 [#:device #f] [#:driver #f] [#:config-file #f] @
23223 [#:extra-options '()]
23224 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
23225 decodes infrared signals from remote controls.
23227 Optionally, @var{device}, @var{driver} and @var{config-file}
23228 (configuration file name) may be specified. See @command{lircd} manual
23231 Finally, @var{extra-options} is a list of additional command-line options
23232 passed to @command{lircd}.
23236 @subsubheading Spice Service
23238 The @code{(gnu services spice)} module provides the following service.
23240 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
23241 Returns a service that runs @url{http://www.spice-space.org,VDAGENT}, a daemon
23242 that enables sharing the clipboard with a vm and setting the guest display
23243 resolution when the graphical console window resizes.
23246 @cindex inputattach
23247 @subsubheading inputattach Service
23249 @cindex tablet input, for Xorg
23250 @cindex touchscreen input, for Xorg
23251 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
23252 use input devices such as Wacom tablets, touchscreens, or joysticks with the
23253 Xorg display server.
23255 @deffn {Scheme Variable} inputattach-service-type
23256 Type of a service that runs @command{inputattach} on a device and
23257 dispatches events from it.
23260 @deftp {Data Type} inputattach-configuration
23262 @item @code{device-type} (default: @code{"wacom"})
23263 The type of device to connect to. Run @command{inputattach --help}, from the
23264 @code{inputattach} package, to see the list of supported device types.
23266 @item @code{device} (default: @code{"/dev/ttyS0"})
23267 The device file to connect to the device.
23269 @item @code{log-file} (default: @code{#f})
23270 If true, this must be the name of a file to log messages to.
23274 @subsection Dictionary Services
23276 The @code{(gnu services dict)} module provides the following service:
23278 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
23279 Return a service that runs the @command{dicod} daemon, an implementation
23280 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
23282 The optional @var{config} argument specifies the configuration for
23283 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
23284 default it serves the GNU Collaborative International Dictonary of English.
23286 You can add @command{open localhost} to your @file{~/.dico} file to make
23287 @code{localhost} the default server for @command{dico} client
23288 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
23291 @deftp {Data Type} dicod-configuration
23292 Data type representing the configuration of dicod.
23295 @item @code{dico} (default: @var{dico})
23296 Package object of the GNU Dico dictionary server.
23298 @item @code{interfaces} (default: @var{'("localhost")})
23299 This is the list of IP addresses and ports and possibly socket file
23300 names to listen to (@pxref{Server Settings, @code{listen} directive,,
23301 dico, GNU Dico Manual}).
23303 @item @code{handlers} (default: @var{'()})
23304 List of @code{<dicod-handler>} objects denoting handlers (module instances).
23306 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
23307 List of @code{<dicod-database>} objects denoting dictionaries to be served.
23311 @deftp {Data Type} dicod-handler
23312 Data type representing a dictionary handler (module instance).
23316 Name of the handler (module instance).
23318 @item @code{module} (default: @var{#f})
23319 Name of the dicod module of the handler (instance). If it is @code{#f},
23320 the module has the same name as the handler.
23321 (@pxref{Modules,,, dico, GNU Dico Manual}).
23323 @item @code{options}
23324 List of strings or gexps representing the arguments for the module handler
23328 @deftp {Data Type} dicod-database
23329 Data type representing a dictionary database.
23333 Name of the database, will be used in DICT commands.
23335 @item @code{handler}
23336 Name of the dicod handler (module instance) used by this database
23337 (@pxref{Handlers,,, dico, GNU Dico Manual}).
23339 @item @code{complex?} (default: @var{#f})
23340 Whether the database configuration complex. The complex configuration
23341 will need a corresponding @code{<dicod-handler>} object, otherwise not.
23343 @item @code{options}
23344 List of strings or gexps representing the arguments for the database
23345 (@pxref{Databases,,, dico, GNU Dico Manual}).
23349 @defvr {Scheme Variable} %dicod-database:gcide
23350 A @code{<dicod-database>} object serving the GNU Collaborative International
23351 Dictionary of English using the @code{gcide} package.
23354 The following is an example @code{dicod-service} configuration.
23357 (dicod-service #:config
23358 (dicod-configuration
23359 (handlers (list (dicod-handler
23363 (list #~(string-append "dbdir=" #$wordnet))))))
23364 (databases (list (dicod-database
23367 (handler "wordnet")
23368 (options '("database=wn")))
23369 %dicod-database:gcide))))
23373 @subsubheading Docker Service
23375 The @code{(gnu services docker)} module provides the following service.
23377 @defvr {Scheme Variable} docker-service-type
23379 This is the type of the service that runs @url{http://www.docker.com,Docker},
23380 a daemon that can execute application bundles (sometimes referred to as
23381 ``containers'') in isolated environments.
23385 @deftp {Data Type} docker-configuration
23386 This is the data type representing the configuration of Docker and Containerd.
23390 @item @code{package} (default: @code{docker})
23391 The Docker package to use.
23393 @item @code{containerd} (default: @var{containerd})
23394 The Containerd package to use.
23399 @node Setuid Programs
23400 @section Setuid Programs
23402 @cindex setuid programs
23403 Some programs need to run with ``root'' privileges, even when they are
23404 launched by unprivileged users. A notorious example is the
23405 @command{passwd} program, which users can run to change their
23406 password, and which needs to access the @file{/etc/passwd} and
23407 @file{/etc/shadow} files---something normally restricted to root, for
23408 obvious security reasons. To address that, these executables are
23409 @dfn{setuid-root}, meaning that they always run with root privileges
23410 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
23411 for more info about the setuid mechanism.)
23413 The store itself @emph{cannot} contain setuid programs: that would be a
23414 security issue since any user on the system can write derivations that
23415 populate the store (@pxref{The Store}). Thus, a different mechanism is
23416 used: instead of changing the setuid bit directly on files that are in
23417 the store, we let the system administrator @emph{declare} which programs
23418 should be setuid root.
23420 The @code{setuid-programs} field of an @code{operating-system}
23421 declaration contains a list of G-expressions denoting the names of
23422 programs to be setuid-root (@pxref{Using the Configuration System}).
23423 For instance, the @command{passwd} program, which is part of the Shadow
23424 package, can be designated by this G-expression (@pxref{G-Expressions}):
23427 #~(string-append #$shadow "/bin/passwd")
23430 A default set of setuid programs is defined by the
23431 @code{%setuid-programs} variable of the @code{(gnu system)} module.
23433 @defvr {Scheme Variable} %setuid-programs
23434 A list of G-expressions denoting common programs that are setuid-root.
23436 The list includes commands such as @command{passwd}, @command{ping},
23437 @command{su}, and @command{sudo}.
23440 Under the hood, the actual setuid programs are created in the
23441 @file{/run/setuid-programs} directory at system activation time. The
23442 files in this directory refer to the ``real'' binaries, which are in the
23445 @node X.509 Certificates
23446 @section X.509 Certificates
23448 @cindex HTTPS, certificates
23449 @cindex X.509 certificates
23451 Web servers available over HTTPS (that is, HTTP over the transport-layer
23452 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
23453 that the client can then use to @emph{authenticate} the server. To do
23454 that, clients verify that the server's certificate is signed by a
23455 so-called @dfn{certificate authority} (CA). But to verify the CA's
23456 signature, clients must have first acquired the CA's certificate.
23458 Web browsers such as GNU@tie{}IceCat include their own set of CA
23459 certificates, such that they are able to verify CA signatures
23462 However, most other programs that can talk HTTPS---@command{wget},
23463 @command{git}, @command{w3m}, etc.---need to be told where CA
23464 certificates can be found.
23466 @cindex @code{nss-certs}
23467 In Guix, this is done by adding a package that provides certificates
23468 to the @code{packages} field of the @code{operating-system} declaration
23469 (@pxref{operating-system Reference}). Guix includes one such package,
23470 @code{nss-certs}, which is a set of CA certificates provided as part of
23471 Mozilla's Network Security Services.
23473 Note that it is @emph{not} part of @var{%base-packages}, so you need to
23474 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
23475 most applications and libraries look for certificates by default, points
23476 to the certificates installed globally.
23478 Unprivileged users, including users of Guix on a foreign distro,
23479 can also install their own certificate package in
23480 their profile. A number of environment variables need to be defined so
23481 that applications and libraries know where to find them. Namely, the
23482 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
23483 variables. Some applications add their own environment variables; for
23484 instance, the Git version control system honors the certificate bundle
23485 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
23486 would typically run something like:
23489 $ guix package -i nss-certs
23490 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
23491 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
23492 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
23495 As another example, R requires the @code{CURL_CA_BUNDLE} environment
23496 variable to point to a certificate bundle, so you would have to run
23497 something like this:
23500 $ guix package -i nss-certs
23501 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
23504 For other applications you may want to look up the required environment
23505 variable in the relevant documentation.
23508 @node Name Service Switch
23509 @section Name Service Switch
23511 @cindex name service switch
23513 The @code{(gnu system nss)} module provides bindings to the
23514 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
23515 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
23516 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
23517 extended with new ``name'' lookup methods for system databases, which
23518 includes host names, service names, user accounts, and more (@pxref{Name
23519 Service Switch, System Databases and Name Service Switch,, libc, The GNU
23520 C Library Reference Manual}).
23522 The NSS configuration specifies, for each system database, which lookup
23523 method is to be used, and how the various methods are chained
23524 together---for instance, under which circumstances NSS should try the
23525 next method in the list. The NSS configuration is given in the
23526 @code{name-service-switch} field of @code{operating-system} declarations
23527 (@pxref{operating-system Reference, @code{name-service-switch}}).
23530 @cindex .local, host name lookup
23531 As an example, the declaration below configures the NSS to use the
23532 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
23533 back-end}, which supports host name lookups over multicast DNS (mDNS)
23534 for host names ending in @code{.local}:
23537 (name-service-switch
23538 (hosts (list %files ;first, check /etc/hosts
23540 ;; If the above did not succeed, try
23541 ;; with 'mdns_minimal'.
23543 (name "mdns_minimal")
23545 ;; 'mdns_minimal' is authoritative for
23546 ;; '.local'. When it returns "not found",
23547 ;; no need to try the next methods.
23548 (reaction (lookup-specification
23549 (not-found => return))))
23551 ;; Then fall back to DNS.
23555 ;; Finally, try with the "full" 'mdns'.
23560 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
23561 contains this configuration, so you will not have to type it if all you
23562 want is to have @code{.local} host lookup working.
23564 Note that, in this case, in addition to setting the
23565 @code{name-service-switch} of the @code{operating-system} declaration,
23566 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
23567 @code{avahi-service-type}}), or @var{%desktop-services}, which includes it
23568 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
23569 to the name service cache daemon (@pxref{Base Services,
23570 @code{nscd-service}}).
23572 For convenience, the following variables provide typical NSS
23575 @defvr {Scheme Variable} %default-nss
23576 This is the default name service switch configuration, a
23577 @code{name-service-switch} object.
23580 @defvr {Scheme Variable} %mdns-host-lookup-nss
23581 This is the name service switch configuration with support for host name
23582 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
23585 The reference for name service switch configuration is given below. It
23586 is a direct mapping of the configuration file format of the C library , so
23587 please refer to the C library manual for more information (@pxref{NSS
23588 Configuration File,,, libc, The GNU C Library Reference Manual}).
23589 Compared to the configuration file format of libc NSS, it has the advantage
23590 not only of adding this warm parenthetic feel that we like, but also
23591 static checks: you will know about syntax errors and typos as soon as you
23592 run @command{guix system}.
23594 @deftp {Data Type} name-service-switch
23596 This is the data type representation the configuration of libc's name
23597 service switch (NSS). Each field below represents one of the supported
23614 The system databases handled by the NSS. Each of these fields must be a
23615 list of @code{<name-service>} objects (see below).
23619 @deftp {Data Type} name-service
23621 This is the data type representing an actual name service and the
23622 associated lookup action.
23626 A string denoting the name service (@pxref{Services in the NSS
23627 configuration,,, libc, The GNU C Library Reference Manual}).
23629 Note that name services listed here must be visible to nscd. This is
23630 achieved by passing the @code{#:name-services} argument to
23631 @code{nscd-service} the list of packages providing the needed name
23632 services (@pxref{Base Services, @code{nscd-service}}).
23635 An action specified using the @code{lookup-specification} macro
23636 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
23637 Reference Manual}). For example:
23640 (lookup-specification (unavailable => continue)
23641 (success => return))
23646 @node Initial RAM Disk
23647 @section Initial RAM Disk
23650 @cindex initial RAM disk
23651 For bootstrapping purposes, the Linux-Libre kernel is passed an
23652 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
23653 root file system as well as an initialization script. The latter is
23654 responsible for mounting the real root file system, and for loading any
23655 kernel modules that may be needed to achieve that.
23657 The @code{initrd-modules} field of an @code{operating-system}
23658 declaration allows you to specify Linux-libre kernel modules that must
23659 be available in the initrd. In particular, this is where you would list
23660 modules needed to actually drive the hard disk where your root partition
23661 is---although the default value of @code{initrd-modules} should cover
23662 most use cases. For example, assuming you need the @code{megaraid_sas}
23663 module in addition to the default modules to be able to access your root
23664 file system, you would write:
23669 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
23672 @defvr {Scheme Variable} %base-initrd-modules
23673 This is the list of kernel modules included in the initrd by default.
23676 Furthermore, if you need lower-level customization, the @code{initrd}
23677 field of an @code{operating-system} declaration allows
23678 you to specify which initrd you would like to use. The @code{(gnu
23679 system linux-initrd)} module provides three ways to build an initrd: the
23680 high-level @code{base-initrd} procedure and the low-level
23681 @code{raw-initrd} and @code{expression->initrd} procedures.
23683 The @code{base-initrd} procedure is intended to cover most common uses.
23684 For example, if you want to add a bunch of kernel modules to be loaded
23685 at boot time, you can define the @code{initrd} field of the operating
23686 system declaration like this:
23689 (initrd (lambda (file-systems . rest)
23690 ;; Create a standard initrd but set up networking
23691 ;; with the parameters QEMU expects by default.
23692 (apply base-initrd file-systems
23693 #:qemu-networking? #t
23697 The @code{base-initrd} procedure also handles common use cases that
23698 involves using the system as a QEMU guest, or as a ``live'' system with
23699 volatile root file system.
23701 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
23702 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
23703 such as trying to guess which kernel modules and packages should be included
23704 to the initrd. An example use of @code{raw-initrd} is when a user has
23705 a custom Linux kernel configuration and default kernel modules included by
23706 @code{base-initrd} are not available.
23708 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
23709 honors several options passed on the Linux kernel command line
23710 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
23711 @code{-append} option of QEMU), notably:
23714 @item --load=@var{boot}
23715 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
23716 program, once it has mounted the root file system.
23718 Guix uses this option to yield control to a boot program that runs the
23719 service activation programs and then spawns the GNU@tie{}Shepherd, the
23720 initialization system.
23722 @item --root=@var{root}
23723 Mount @var{root} as the root file system. @var{root} can be a
23724 device name like @code{/dev/sda1}, a file system label, or a file system
23727 @item --system=@var{system}
23728 Have @file{/run/booted-system} and @file{/run/current-system} point to
23731 @item modprobe.blacklist=@var{modules}@dots{}
23732 @cindex module, black-listing
23733 @cindex black list, of kernel modules
23734 Instruct the initial RAM disk as well as the @command{modprobe} command
23735 (from the kmod package) to refuse to load @var{modules}. @var{modules}
23736 must be a comma-separated list of module names---e.g.,
23737 @code{usbkbd,9pnet}.
23740 Start a read-eval-print loop (REPL) from the initial RAM disk before it
23741 tries to load kernel modules and to mount the root file system. Our
23742 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
23743 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
23744 Manual}, for more information on Guile's REPL.
23748 Now that you know all the features that initial RAM disks produced by
23749 @code{base-initrd} and @code{raw-initrd} provide,
23750 here is how to use it and customize it further.
23753 @cindex initial RAM disk
23754 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
23755 [#:linux-modules '()] [#:mapped-devices '()] @
23756 [#:keyboard-layout #f] @
23757 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
23758 Return a derivation that builds a raw initrd. @var{file-systems} is
23759 a list of file systems to be mounted by the initrd, possibly in addition to
23760 the root file system specified on the kernel command line via @code{--root}.
23761 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
23762 @var{mapped-devices} is a list of device mappings to realize before
23763 @var{file-systems} are mounted (@pxref{Mapped Devices}).
23764 @var{helper-packages} is a list of packages to be copied in the initrd. It may
23765 include @code{e2fsck/static} or other packages needed by the initrd to check
23766 the root file system.
23768 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
23769 the desired console keyboard layout. This is done before @var{mapped-devices}
23770 are set up and before @var{file-systems} are mounted such that, should the
23771 user need to enter a passphrase or use the REPL, this happens using the
23772 intended keyboard layout.
23774 When @var{qemu-networking?} is true, set up networking with the standard QEMU
23775 parameters. When @var{virtio?} is true, load additional modules so that the
23776 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
23778 When @var{volatile-root?} is true, the root file system is writable but any changes
23782 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
23783 [#:mapped-devices '()] [#:keyboard-layout #f] @
23784 [#:qemu-networking? #f] [#:volatile-root? #f] @
23785 [#:linux-modules '()]
23786 Return as a file-like object a generic initrd, with kernel
23787 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
23788 mounted by the initrd, possibly in addition to the root file system specified
23789 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
23790 mappings to realize before @var{file-systems} are mounted.
23792 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
23793 the desired console keyboard layout. This is done before @var{mapped-devices}
23794 are set up and before @var{file-systems} are mounted such that, should the
23795 user need to enter a passphrase or use the REPL, this happens using the
23796 intended keyboard layout.
23798 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
23800 The initrd is automatically populated with all the kernel modules necessary
23801 for @var{file-systems} and for the given options. Additional kernel
23802 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
23803 loaded at boot time in the order in which they appear.
23806 Needless to say, the initrds we produce and use embed a
23807 statically-linked Guile, and the initialization program is a Guile
23808 program. That gives a lot of flexibility. The
23809 @code{expression->initrd} procedure builds such an initrd, given the
23810 program to run in that initrd.
23812 @deffn {Scheme Procedure} expression->initrd @var{exp} @
23813 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
23814 Return as a file-like object a Linux initrd (a gzipped cpio archive)
23815 containing @var{guile} and that evaluates @var{exp}, a G-expression,
23816 upon booting. All the derivations referenced by @var{exp} are
23817 automatically copied to the initrd.
23820 @node Bootloader Configuration
23821 @section Bootloader Configuration
23824 @cindex boot loader
23826 The operating system supports multiple bootloaders. The bootloader is
23827 configured using @code{bootloader-configuration} declaration. All the
23828 fields of this structure are bootloader agnostic except for one field,
23829 @code{bootloader} that indicates the bootloader to be configured and
23832 Some of the bootloaders do not honor every field of
23833 @code{bootloader-configuration}. For instance, the extlinux
23834 bootloader does not support themes and thus ignores the @code{theme}
23837 @deftp {Data Type} bootloader-configuration
23838 The type of a bootloader configuration declaration.
23842 @item @code{bootloader}
23843 @cindex EFI, bootloader
23844 @cindex UEFI, bootloader
23845 @cindex BIOS, bootloader
23846 The bootloader to use, as a @code{bootloader} object. For now
23847 @code{grub-bootloader}, @code{grub-efi-bootloader},
23848 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
23850 @vindex grub-efi-bootloader
23851 @code{grub-efi-bootloader} allows to boot on modern systems using the
23852 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
23853 use if the installation image contains a @file{/sys/firmware/efi} directory
23854 when you boot it on your system.
23856 @vindex grub-bootloader
23857 @code{grub-bootloader} allows you to boot in particular Intel-based machines
23858 in ``legacy'' BIOS mode.
23860 @cindex ARM, bootloaders
23861 @cindex AArch64, bootloaders
23862 Available bootloaders are described in @code{(gnu bootloader @dots{})}
23863 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
23864 of bootloaders for a wide range of ARM and AArch64 systems, using the
23865 @uref{http://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
23867 @item @code{target}
23868 This is a string denoting the target onto which to install the
23871 The interpretation depends on the bootloader in question. For
23872 @code{grub-bootloader}, for example, it should be a device name understood by
23873 the bootloader @command{installer} command, such as @code{/dev/sda} or
23874 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
23875 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
23876 system, usually @file{/boot/efi}.
23878 @item @code{menu-entries} (default: @code{()})
23879 A possibly empty list of @code{menu-entry} objects (see below), denoting
23880 entries to appear in the bootloader menu, in addition to the current
23881 system entry and the entry pointing to previous system generations.
23883 @item @code{default-entry} (default: @code{0})
23884 The index of the default boot menu entry. Index 0 is for the entry of the
23887 @item @code{timeout} (default: @code{5})
23888 The number of seconds to wait for keyboard input before booting. Set to
23889 0 to boot immediately, and to -1 to wait indefinitely.
23891 @cindex keyboard layout, for the bootloader
23892 @item @code{keyboard-layout} (default: @code{#f})
23893 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
23894 layout, usually US@tie{}English (``qwerty'').
23896 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
23900 This option is currently ignored by bootloaders other than @code{grub} and
23904 @item @code{theme} (default: @var{#f})
23905 The bootloader theme object describing the theme to use. If no theme
23906 is provided, some bootloaders might use a default theme, that's true
23909 @item @code{terminal-outputs} (default: @code{'gfxterm})
23910 The output terminals used for the bootloader boot menu, as a list of
23911 symbols. GRUB accepts the values: @code{console}, @code{serial},
23912 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
23913 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
23914 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
23915 configuration,,, grub,GNU GRUB manual}).
23917 @item @code{terminal-inputs} (default: @code{'()})
23918 The input terminals used for the bootloader boot menu, as a list of
23919 symbols. For GRUB, the default is the native platform terminal as
23920 determined at run-time. GRUB accepts the values: @code{console},
23921 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
23922 @code{usb_keyboard}. This field corresponds to the GRUB variable
23923 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
23926 @item @code{serial-unit} (default: @code{#f})
23927 The serial unit used by the bootloader, as an integer from 0 to 3.
23928 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
23929 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
23931 @item @code{serial-speed} (default: @code{#f})
23932 The speed of the serial interface, as an integer. For GRUB, the
23933 default value is chosen at run-time; currently GRUB chooses
23934 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
23941 Should you want to list additional boot menu entries @i{via} the
23942 @code{menu-entries} field above, you will need to create them with the
23943 @code{menu-entry} form. For example, imagine you want to be able to
23944 boot another distro (hard to imagine!), you can define a menu entry
23949 (label "The Other Distro")
23950 (linux "/boot/old/vmlinux-2.6.32")
23951 (linux-arguments '("root=/dev/sda2"))
23952 (initrd "/boot/old/initrd"))
23957 @deftp {Data Type} menu-entry
23958 The type of an entry in the bootloader menu.
23963 The label to show in the menu---e.g., @code{"GNU"}.
23966 The Linux kernel image to boot, for example:
23969 (file-append linux-libre "/bzImage")
23972 For GRUB, it is also possible to specify a device explicitly in the
23973 file path using GRUB's device naming convention (@pxref{Naming
23974 convention,,, grub, GNU GRUB manual}), for example:
23977 "(hd0,msdos1)/boot/vmlinuz"
23980 If the device is specified explicitly as above, then the @code{device}
23981 field is ignored entirely.
23983 @item @code{linux-arguments} (default: @code{()})
23984 The list of extra Linux kernel command-line arguments---e.g.,
23985 @code{("console=ttyS0")}.
23987 @item @code{initrd}
23988 A G-Expression or string denoting the file name of the initial RAM disk
23989 to use (@pxref{G-Expressions}).
23990 @item @code{device} (default: @code{#f})
23991 The device where the kernel and initrd are to be found---i.e., for GRUB,
23992 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
23994 This may be a file system label (a string), a file system UUID (a
23995 bytevector, @pxref{File Systems}), or @code{#f}, in which case
23996 the bootloader will search the device containing the file specified by
23997 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
23998 must @emph{not} be an OS device name such as @file{/dev/sda1}.
24003 @c FIXME: Write documentation once it's stable.
24004 Fow now only GRUB has theme support. GRUB themes are created using
24005 the @code{grub-theme} form, which is not documented yet.
24007 @defvr {Scheme Variable} %default-theme
24008 This is the default GRUB theme used by the operating system if no
24009 @code{theme} field is specified in @code{bootloader-configuration}
24012 It comes with a fancy background image displaying the GNU and Guix
24017 @node Invoking guix system
24018 @section Invoking @code{guix system}
24020 Once you have written an operating system declaration as seen in the
24021 previous section, it can be @dfn{instantiated} using the @command{guix
24022 system} command. The synopsis is:
24025 guix system @var{options}@dots{} @var{action} @var{file}
24028 @var{file} must be the name of a file containing an
24029 @code{operating-system} declaration. @var{action} specifies how the
24030 operating system is instantiated. Currently the following values are
24035 Display available service type definitions that match the given regular
24036 expressions, sorted by relevance:
24039 $ guix system search console font
24040 name: console-fonts
24041 location: gnu/services/base.scm:729:2
24042 extends: shepherd-root
24043 description: Install the given fonts on the specified ttys (fonts are
24044 + per virtual console on GNU/Linux). The value of this service is a list
24045 + of tty/font pairs like:
24047 + '(("tty1" . "LatGrkCyr-8x16"))
24051 location: gnu/services/base.scm:1048:2
24052 extends: shepherd-root
24053 description: Provide console login using the `mingetty' program.
24057 location: gnu/services/base.scm:775:2
24059 description: Provide a console log-in service as specified by its
24060 + configuration value, a `login-configuration' object.
24066 As for @command{guix package --search}, the result is written in
24067 @code{recutils} format, which makes it easy to filter the output
24068 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
24071 Build the operating system described in @var{file}, activate it, and
24072 switch to it@footnote{This action (and the related actions
24073 @code{switch-generation} and @code{roll-back}) are usable only on
24074 systems already running Guix System.}.
24076 This effects all the configuration specified in @var{file}: user
24077 accounts, system services, global package list, setuid programs, etc.
24078 The command starts system services specified in @var{file} that are not
24079 currently running; if a service is currently running this command will
24080 arrange for it to be upgraded the next time it is stopped (e.g.@: by
24081 @code{herd stop X} or @code{herd restart X}).
24083 This command creates a new generation whose number is one greater than
24084 the current generation (as reported by @command{guix system
24085 list-generations}). If that generation already exists, it will be
24086 overwritten. This behavior mirrors that of @command{guix package}
24087 (@pxref{Invoking guix package}).
24089 It also adds a bootloader menu entry for the new OS configuration,
24090 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
24091 entries for older configurations to a submenu, allowing you to choose
24092 an older system generation at boot time should you need it.
24095 @c The paragraph below refers to the problem discussed at
24096 @c <http://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
24097 It is highly recommended to run @command{guix pull} once before you run
24098 @command{guix system reconfigure} for the first time (@pxref{Invoking
24099 guix pull}). Failing to do that you would see an older version of Guix
24100 once @command{reconfigure} has completed.
24103 @item switch-generation
24104 @cindex generations
24105 Switch to an existing system generation. This action atomically
24106 switches the system profile to the specified system generation. It
24107 also rearranges the system's existing bootloader menu entries. It
24108 makes the menu entry for the specified system generation the default,
24109 and it moves the entries for the other generatiors to a submenu, if
24110 supported by the bootloader being used. The next time the system
24111 boots, it will use the specified system generation.
24113 The bootloader itself is not being reinstalled when using this
24114 command. Thus, the installed bootloader is used with an updated
24115 configuration file.
24117 The target generation can be specified explicitly by its generation
24118 number. For example, the following invocation would switch to system
24122 guix system switch-generation 7
24125 The target generation can also be specified relative to the current
24126 generation with the form @code{+N} or @code{-N}, where @code{+3} means
24127 ``3 generations ahead of the current generation,'' and @code{-1} means
24128 ``1 generation prior to the current generation.'' When specifying a
24129 negative value such as @code{-1}, you must precede it with @code{--} to
24130 prevent it from being parsed as an option. For example:
24133 guix system switch-generation -- -1
24136 Currently, the effect of invoking this action is @emph{only} to switch
24137 the system profile to an existing generation and rearrange the
24138 bootloader menu entries. To actually start using the target system
24139 generation, you must reboot after running this action. In the future,
24140 it will be updated to do the same things as @command{reconfigure},
24141 like activating and deactivating services.
24143 This action will fail if the specified generation does not exist.
24146 @cindex rolling back
24147 Switch to the preceding system generation. The next time the system
24148 boots, it will use the preceding system generation. This is the inverse
24149 of @command{reconfigure}, and it is exactly the same as invoking
24150 @command{switch-generation} with an argument of @code{-1}.
24152 Currently, as with @command{switch-generation}, you must reboot after
24153 running this action to actually start using the preceding system
24156 @item delete-generations
24157 @cindex deleting system generations
24158 @cindex saving space
24159 Delete system generations, making them candidates for garbage collection
24160 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
24163 This works in the same way as @command{guix package --delete-generations}
24164 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
24165 arguments, all system generations but the current one are deleted:
24168 guix system delete-generations
24171 You can also select the generations you want to delete. The example below
24172 deletes all the system generations that are more than two month old:
24175 guix system delete-generations 2m
24178 Running this command automatically reinstalls the bootloader with an updated
24179 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
24180 longer lists the generations that have been deleted.
24183 Build the derivation of the operating system, which includes all the
24184 configuration files and programs needed to boot and run the system.
24185 This action does not actually install anything.
24188 Populate the given directory with all the files necessary to run the
24189 operating system specified in @var{file}. This is useful for first-time
24190 installations of Guix System. For instance:
24193 guix system init my-os-config.scm /mnt
24196 copies to @file{/mnt} all the store items required by the configuration
24197 specified in @file{my-os-config.scm}. This includes configuration
24198 files, packages, and so on. It also creates other essential files
24199 needed for the system to operate correctly---e.g., the @file{/etc},
24200 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
24202 This command also installs bootloader on the target specified in
24203 @file{my-os-config}, unless the @option{--no-bootloader} option was
24207 @cindex virtual machine
24209 @anchor{guix system vm}
24210 Build a virtual machine that contains the operating system declared in
24211 @var{file}, and return a script to run that virtual machine (VM).
24214 The @code{vm} action and others below
24215 can use KVM support in the Linux-libre kernel. Specifically, if the
24216 machine has hardware virtualization support, the corresponding
24217 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
24218 must exist and be readable and writable by the user and by the
24219 build users of the daemon (@pxref{Build Environment Setup}).
24222 Arguments given to the script are passed to QEMU as in the example
24223 below, which enables networking and requests 1@tie{}GiB of RAM for the
24227 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
24230 The VM shares its store with the host system.
24232 Additional file systems can be shared between the host and the VM using
24233 the @code{--share} and @code{--expose} command-line options: the former
24234 specifies a directory to be shared with write access, while the latter
24235 provides read-only access to the shared directory.
24237 The example below creates a VM in which the user's home directory is
24238 accessible read-only, and where the @file{/exchange} directory is a
24239 read-write mapping of @file{$HOME/tmp} on the host:
24242 guix system vm my-config.scm \
24243 --expose=$HOME --share=$HOME/tmp=/exchange
24246 On GNU/Linux, the default is to boot directly to the kernel; this has
24247 the advantage of requiring only a very tiny root disk image since the
24248 store of the host can then be mounted.
24250 The @code{--full-boot} option forces a complete boot sequence, starting
24251 with the bootloader. This requires more disk space since a root image
24252 containing at least the kernel, initrd, and bootloader data files must
24253 be created. The @code{--image-size} option can be used to specify the
24256 @cindex System images, creation in various formats
24257 @cindex Creating system images in various formats
24260 @itemx docker-image
24261 Return a virtual machine, disk image, or Docker image of the operating
24262 system declared in @var{file} that stands alone. By default,
24263 @command{guix system} estimates the size of the image needed to store
24264 the system, but you can use the @option{--image-size} option to specify
24265 a value. Docker images are built to contain exactly what they need, so
24266 the @option{--image-size} option is ignored in the case of
24267 @code{docker-image}.
24269 You can specify the root file system type by using the
24270 @option{--file-system-type} option. It defaults to @code{ext4}.
24272 When using @code{vm-image}, the returned image is in qcow2 format, which
24273 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
24274 for more information on how to run the image in a virtual machine.
24276 When using @code{disk-image}, a raw disk image is produced; it can be
24277 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
24278 the device corresponding to a USB stick, one can copy the image to it
24279 using the following command:
24282 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
24285 When using @code{docker-image}, a Docker image is produced. Guix builds
24286 the image from scratch, not from a pre-existing Docker base image. As a
24287 result, it contains @emph{exactly} what you define in the operating
24288 system configuration file. You can then load the image and launch a
24289 Docker container using commands like the following:
24292 image_id="$(docker load < guix-system-docker-image.tar.gz)"
24293 docker run -e GUIX_NEW_SYSTEM=/var/guix/profiles/system \\
24294 --entrypoint /var/guix/profiles/system/profile/bin/guile \\
24295 $image_id /var/guix/profiles/system/boot
24298 This command starts a new Docker container from the specified image. It
24299 will boot the Guix system in the usual manner, which means it will
24300 start any services you have defined in the operating system
24301 configuration. Depending on what you run in the Docker container, it
24302 may be necessary to give the container additional permissions. For
24303 example, if you intend to build software using Guix inside of the Docker
24304 container, you may need to pass the @option{--privileged} option to
24308 Return a script to run the operating system declared in @var{file}
24309 within a container. Containers are a set of lightweight isolation
24310 mechanisms provided by the kernel Linux-libre. Containers are
24311 substantially less resource-demanding than full virtual machines since
24312 the kernel, shared objects, and other resources can be shared with the
24313 host system; this also means they provide thinner isolation.
24315 Currently, the script must be run as root in order to support more than
24316 a single user and group. The container shares its store with the host
24319 As with the @code{vm} action (@pxref{guix system vm}), additional file
24320 systems to be shared between the host and container can be specified
24321 using the @option{--share} and @option{--expose} options:
24324 guix system container my-config.scm \
24325 --expose=$HOME --share=$HOME/tmp=/exchange
24329 This option requires Linux-libre 3.19 or newer.
24334 @var{options} can contain any of the common build options (@pxref{Common
24335 Build Options}). In addition, @var{options} can contain one of the
24339 @item --expression=@var{expr}
24340 @itemx -e @var{expr}
24341 Consider the operating-system @var{expr} evaluates to.
24342 This is an alternative to specifying a file which evaluates to an
24344 This is used to generate the Guix system installer @pxref{Building the
24345 Installation Image}).
24347 @item --system=@var{system}
24348 @itemx -s @var{system}
24349 Attempt to build for @var{system} instead of the host system type.
24350 This works as per @command{guix build} (@pxref{Invoking guix build}).
24354 Return the derivation file name of the given operating system without
24357 @item --file-system-type=@var{type}
24358 @itemx -t @var{type}
24359 For the @code{disk-image} action, create a file system of the given
24360 @var{type} on the image.
24362 When this option is omitted, @command{guix system} uses @code{ext4}.
24364 @cindex ISO-9660 format
24365 @cindex CD image format
24366 @cindex DVD image format
24367 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
24368 for burning on CDs and DVDs.
24370 @item --image-size=@var{size}
24371 For the @code{vm-image} and @code{disk-image} actions, create an image
24372 of the given @var{size}. @var{size} may be a number of bytes, or it may
24373 include a unit as a suffix (@pxref{Block size, size specifications,,
24374 coreutils, GNU Coreutils}).
24376 When this option is omitted, @command{guix system} computes an estimate
24377 of the image size as a function of the size of the system declared in
24380 @item --root=@var{file}
24381 @itemx -r @var{file}
24382 Make @var{file} a symlink to the result, and register it as a garbage
24385 @item --skip-checks
24386 Skip pre-installation safety checks.
24388 By default, @command{guix system init} and @command{guix system
24389 reconfigure} perform safety checks: they make sure the file systems that
24390 appear in the @code{operating-system} declaration actually exist
24391 (@pxref{File Systems}), and that any Linux kernel modules that may be
24392 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
24393 RAM Disk}). Passing this option skips these tests altogether.
24396 @cindex on-error strategy
24397 @cindex error strategy
24398 @item --on-error=@var{strategy}
24399 Apply @var{strategy} when an error occurs when reading @var{file}.
24400 @var{strategy} may be one of the following:
24403 @item nothing-special
24404 Report the error concisely and exit. This is the default strategy.
24407 Likewise, but also display a backtrace.
24410 Report the error and enter Guile's debugger. From there, you can run
24411 commands such as @code{,bt} to get a backtrace, @code{,locals} to
24412 display local variable values, and more generally inspect the state of the
24413 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
24414 a list of available debugging commands.
24418 Once you have built, configured, re-configured, and re-re-configured
24419 your Guix installation, you may find it useful to list the operating
24420 system generations available on disk---and that you can choose from the
24421 bootloader boot menu:
24425 @item list-generations
24426 List a summary of each generation of the operating system available on
24427 disk, in a human-readable way. This is similar to the
24428 @option{--list-generations} option of @command{guix package}
24429 (@pxref{Invoking guix package}).
24431 Optionally, one can specify a pattern, with the same syntax that is used
24432 in @command{guix package --list-generations}, to restrict the list of
24433 generations displayed. For instance, the following command displays
24434 generations that are up to 10 days old:
24437 $ guix system list-generations 10d
24442 The @command{guix system} command has even more to offer! The following
24443 sub-commands allow you to visualize how your system services relate to
24446 @anchor{system-extension-graph}
24449 @item extension-graph
24450 Emit in Dot/Graphviz format to standard output the @dfn{service
24451 extension graph} of the operating system defined in @var{file}
24452 (@pxref{Service Composition}, for more information on service
24458 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
24461 produces a PDF file showing the extension relations among services.
24463 @anchor{system-shepherd-graph}
24464 @item shepherd-graph
24465 Emit in Dot/Graphviz format to standard output the @dfn{dependency
24466 graph} of shepherd services of the operating system defined in
24467 @var{file}. @xref{Shepherd Services}, for more information and for an
24472 @node Running Guix in a VM
24473 @section Running Guix in a Virtual Machine
24475 @cindex virtual machine
24476 To run Guix in a virtual machine (VM), one can either use the
24477 pre-built Guix VM image distributed at
24478 @indicateurl{https://alpha.gnu.org/gnu/guix/guix-system-vm-image-@value{VERSION}.@var{system}.xz}
24479 , or build their own virtual machine image using @command{guix system
24480 vm-image} (@pxref{Invoking guix system}). The returned image is in
24481 qcow2 format, which the @uref{http://qemu.org/, QEMU emulator} can
24485 If you built your own image, you must copy it out of the store
24486 (@pxref{The Store}) and give yourself permission to write to the copy
24487 before you can use it. When invoking QEMU, you must choose a system
24488 emulator that is suitable for your hardware platform. Here is a minimal
24489 QEMU invocation that will boot the result of @command{guix system
24490 vm-image} on x86_64 hardware:
24493 $ qemu-system-x86_64 \
24494 -net user -net nic,model=virtio \
24495 -enable-kvm -m 256 /tmp/qemu-image
24498 Here is what each of these options means:
24501 @item qemu-system-x86_64
24502 This specifies the hardware platform to emulate. This should match the
24506 Enable the unprivileged user-mode network stack. The guest OS can
24507 access the host but not vice versa. This is the simplest way to get the
24510 @item -net nic,model=virtio
24511 You must create a network interface of a given model. If you do not
24512 create a NIC, the boot will fail. Assuming your hardware platform is
24513 x86_64, you can get a list of available NIC models by running
24514 @command{qemu-system-x86_64 -net nic,model=help}.
24517 If your system has hardware virtualization extensions, enabling the
24518 virtual machine support (KVM) of the Linux kernel will make things run
24522 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
24523 which may be insufficient for some operations.
24525 @item /tmp/qemu-image
24526 The file name of the qcow2 image.
24529 The default @command{run-vm.sh} script that is returned by an invocation of
24530 @command{guix system vm} does not add a @command{-net user} flag by default.
24531 To get network access from within the vm add the @code{(dhcp-client-service)}
24532 to your system definition and start the VM using
24533 @command{`guix system vm config.scm` -net user}. An important caveat of using
24534 @command{-net user} for networking is that @command{ping} will not work, because
24535 it uses the ICMP protocol. You'll have to use a different command to check for
24536 network connectivity, for example @command{guix download}.
24538 @subsection Connecting Through SSH
24542 To enable SSH inside a VM you need to add a SSH server like @code{(dropbear-service)}
24543 or @code{(lsh-service)} to your VM. The @code{(lsh-service}) doesn't currently
24544 boot unsupervised. It requires you to type some characters to initialize the
24545 randomness generator. In addition you need to forward the SSH port, 22 by
24546 default, to the host. You can do this with
24549 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
24552 To connect to the VM you can run
24555 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
24558 The @command{-p} tells @command{ssh} the port you want to connect to.
24559 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
24560 every time you modify your @command{config.scm} file and the
24561 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
24562 connection to an unknown host every time you connect.
24564 @subsection Using @command{virt-viewer} with Spice
24566 As an alternative to the default @command{qemu} graphical client you can
24567 use the @command{remote-viewer} from the @command{virt-viewer} package. To
24568 connect pass the @command{-spice port=5930,disable-ticketing} flag to
24569 @command{qemu}. See previous section for further information on how to do this.
24571 Spice also allows you to do some nice stuff like share your clipboard with your
24572 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
24575 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
24576 -chardev spicevmc,name=vdagent,id=vdagent
24577 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
24578 name=com.redhat.spice.0
24581 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
24583 @node Defining Services
24584 @section Defining Services
24586 The previous sections show the available services and how one can combine
24587 them in an @code{operating-system} declaration. But how do we define
24588 them in the first place? And what is a service anyway?
24591 * Service Composition:: The model for composing services.
24592 * Service Types and Services:: Types and services.
24593 * Service Reference:: API reference.
24594 * Shepherd Services:: A particular type of service.
24597 @node Service Composition
24598 @subsection Service Composition
24602 Here we define a @dfn{service} as, broadly, something that extends the
24603 functionality of the operating system. Often a service is a process---a
24604 @dfn{daemon}---started when the system boots: a secure shell server, a
24605 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
24606 whose execution can be triggered by another daemon---e.g., an FTP server
24607 started by @command{inetd} or a D-Bus service activated by
24608 @command{dbus-daemon}. Occasionally, a service does not map to a
24609 daemon. For instance, the ``account'' service collects user accounts
24610 and makes sure they exist when the system runs; the ``udev'' service
24611 collects device management rules and makes them available to the eudev
24612 daemon; the @file{/etc} service populates the @file{/etc} directory
24615 @cindex service extensions
24616 Guix system services are connected by @dfn{extensions}. For instance, the
24617 secure shell service @emph{extends} the Shepherd---the
24618 initialization system, running as PID@tie{}1---by giving it the command
24619 lines to start and stop the secure shell daemon (@pxref{Networking
24620 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
24621 service by passing it its @file{.service} specification, and extends the
24622 udev service by passing it device management rules (@pxref{Desktop
24623 Services, @code{upower-service}}); the Guix daemon service extends the
24624 Shepherd by passing it the command lines to start and stop the daemon,
24625 and extends the account service by passing it a list of required build
24626 user accounts (@pxref{Base Services}).
24628 All in all, services and their ``extends'' relations form a directed
24629 acyclic graph (DAG). If we represent services as boxes and extensions
24630 as arrows, a typical system might provide something like this:
24632 @image{images/service-graph,,5in,Typical service extension graph.}
24634 @cindex system service
24635 At the bottom, we see the @dfn{system service}, which produces the
24636 directory containing everything to run and boot the system, as returned
24637 by the @command{guix system build} command. @xref{Service Reference},
24638 to learn about the other service types shown here.
24639 @xref{system-extension-graph, the @command{guix system extension-graph}
24640 command}, for information on how to generate this representation for a
24641 particular operating system definition.
24643 @cindex service types
24644 Technically, developers can define @dfn{service types} to express these
24645 relations. There can be any number of services of a given type on the
24646 system---for instance, a system running two instances of the GNU secure
24647 shell server (lsh) has two instances of @code{lsh-service-type}, with
24648 different parameters.
24650 The following section describes the programming interface for service
24651 types and services.
24653 @node Service Types and Services
24654 @subsection Service Types and Services
24656 A @dfn{service type} is a node in the DAG described above. Let us start
24657 with a simple example, the service type for the Guix build daemon
24658 (@pxref{Invoking guix-daemon}):
24661 (define guix-service-type
24665 (list (service-extension shepherd-root-service-type guix-shepherd-service)
24666 (service-extension account-service-type guix-accounts)
24667 (service-extension activation-service-type guix-activation)))
24668 (default-value (guix-configuration))))
24672 It defines three things:
24676 A name, whose sole purpose is to make inspection and debugging easier.
24679 A list of @dfn{service extensions}, where each extension designates the
24680 target service type and a procedure that, given the parameters of the
24681 service, returns a list of objects to extend the service of that type.
24683 Every service type has at least one service extension. The only
24684 exception is the @dfn{boot service type}, which is the ultimate service.
24687 Optionally, a default value for instances of this type.
24690 In this example, @var{guix-service-type} extends three services:
24693 @item shepherd-root-service-type
24694 The @var{guix-shepherd-service} procedure defines how the Shepherd
24695 service is extended. Namely, it returns a @code{<shepherd-service>}
24696 object that defines how @command{guix-daemon} is started and stopped
24697 (@pxref{Shepherd Services}).
24699 @item account-service-type
24700 This extension for this service is computed by @var{guix-accounts},
24701 which returns a list of @code{user-group} and @code{user-account}
24702 objects representing the build user accounts (@pxref{Invoking
24705 @item activation-service-type
24706 Here @var{guix-activation} is a procedure that returns a gexp, which is
24707 a code snippet to run at ``activation time''---e.g., when the service is
24711 A service of this type is instantiated like this:
24714 (service guix-service-type
24715 (guix-configuration
24717 (use-substitutes? #f)))
24720 The second argument to the @code{service} form is a value representing
24721 the parameters of this specific service instance.
24722 @xref{guix-configuration-type, @code{guix-configuration}}, for
24723 information about the @code{guix-configuration} data type. When the
24724 value is omitted, the default value specified by
24725 @code{guix-service-type} is used:
24728 (service guix-service-type)
24731 @var{guix-service-type} is quite simple because it extends other
24732 services but is not extensible itself.
24734 @c @subsubsubsection Extensible Service Types
24736 The service type for an @emph{extensible} service looks like this:
24739 (define udev-service-type
24740 (service-type (name 'udev)
24742 (list (service-extension shepherd-root-service-type
24743 udev-shepherd-service)))
24745 (compose concatenate) ;concatenate the list of rules
24746 (extend (lambda (config rules)
24748 (($ <udev-configuration> udev initial-rules)
24749 (udev-configuration
24750 (udev udev) ;the udev package to use
24751 (rules (append initial-rules rules)))))))))
24754 This is the service type for the
24755 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
24756 management daemon}. Compared to the previous example, in addition to an
24757 extension of @var{shepherd-root-service-type}, we see two new fields:
24761 This is the procedure to @dfn{compose} the list of extensions to
24762 services of this type.
24764 Services can extend the udev service by passing it lists of rules; we
24765 compose those extensions simply by concatenating them.
24768 This procedure defines how the value of the service is @dfn{extended} with
24769 the composition of the extensions.
24771 Udev extensions are composed into a list of rules, but the udev service
24772 value is itself a @code{<udev-configuration>} record. So here, we
24773 extend that record by appending the list of rules it contains to the
24774 list of contributed rules.
24777 This is a string giving an overview of the service type. The string can
24778 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
24779 @command{guix system search} command searches these strings and displays
24780 them (@pxref{Invoking guix system}).
24783 There can be only one instance of an extensible service type such as
24784 @var{udev-service-type}. If there were more, the
24785 @code{service-extension} specifications would be ambiguous.
24787 Still here? The next section provides a reference of the programming
24788 interface for services.
24790 @node Service Reference
24791 @subsection Service Reference
24793 We have seen an overview of service types (@pxref{Service Types and
24794 Services}). This section provides a reference on how to manipulate
24795 services and service types. This interface is provided by the
24796 @code{(gnu services)} module.
24798 @deffn {Scheme Procedure} service @var{type} [@var{value}]
24799 Return a new service of @var{type}, a @code{<service-type>} object (see
24800 below.) @var{value} can be any object; it represents the parameters of
24801 this particular service instance.
24803 When @var{value} is omitted, the default value specified by @var{type}
24804 is used; if @var{type} does not specify a default value, an error is
24807 For instance, this:
24810 (service openssh-service-type)
24814 is equivalent to this:
24817 (service openssh-service-type
24818 (openssh-configuration))
24821 In both cases the result is an instance of @code{openssh-service-type}
24822 with the default configuration.
24825 @deffn {Scheme Procedure} service? @var{obj}
24826 Return true if @var{obj} is a service.
24829 @deffn {Scheme Procedure} service-kind @var{service}
24830 Return the type of @var{service}---i.e., a @code{<service-type>} object.
24833 @deffn {Scheme Procedure} service-value @var{service}
24834 Return the value associated with @var{service}. It represents its
24838 Here is an example of how a service is created and manipulated:
24842 (service nginx-service-type
24843 (nginx-configuration
24845 (log-directory log-directory)
24846 (run-directory run-directory)
24847 (file config-file))))
24852 (eq? (service-kind s) nginx-service-type)
24856 The @code{modify-services} form provides a handy way to change the
24857 parameters of some of the services of a list such as
24858 @var{%base-services} (@pxref{Base Services, @code{%base-services}}). It
24859 evaluates to a list of services. Of course, you could always use
24860 standard list combinators such as @code{map} and @code{fold} to do that
24861 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
24862 @code{modify-services} simply provides a more concise form for this
24865 @deffn {Scheme Syntax} modify-services @var{services} @
24866 (@var{type} @var{variable} => @var{body}) @dots{}
24868 Modify the services listed in @var{services} according to the given
24869 clauses. Each clause has the form:
24872 (@var{type} @var{variable} => @var{body})
24875 where @var{type} is a service type---e.g.,
24876 @code{guix-service-type}---and @var{variable} is an identifier that is
24877 bound within the @var{body} to the service parameters---e.g., a
24878 @code{guix-configuration} instance---of the original service of that
24881 The @var{body} should evaluate to the new service parameters, which will
24882 be used to configure the new service. This new service will replace the
24883 original in the resulting list. Because a service's service parameters
24884 are created using @code{define-record-type*}, you can write a succinct
24885 @var{body} that evaluates to the new service parameters by using the
24886 @code{inherit} feature that @code{define-record-type*} provides.
24888 @xref{Using the Configuration System}, for example usage.
24892 Next comes the programming interface for service types. This is
24893 something you want to know when writing new service definitions, but not
24894 necessarily when simply looking for ways to customize your
24895 @code{operating-system} declaration.
24897 @deftp {Data Type} service-type
24898 @cindex service type
24899 This is the representation of a @dfn{service type} (@pxref{Service Types
24904 This is a symbol, used only to simplify inspection and debugging.
24906 @item @code{extensions}
24907 A non-empty list of @code{<service-extension>} objects (see below).
24909 @item @code{compose} (default: @code{#f})
24910 If this is @code{#f}, then the service type denotes services that cannot
24911 be extended---i.e., services that do not receive ``values'' from other
24914 Otherwise, it must be a one-argument procedure. The procedure is called
24915 by @code{fold-services} and is passed a list of values collected from
24916 extensions. It may return any single value.
24918 @item @code{extend} (default: @code{#f})
24919 If this is @code{#f}, services of this type cannot be extended.
24921 Otherwise, it must be a two-argument procedure: @code{fold-services}
24922 calls it, passing it the initial value of the service as the first
24923 argument and the result of applying @code{compose} to the extension
24924 values as the second argument. It must return a value that is a valid
24925 parameter value for the service instance.
24928 @xref{Service Types and Services}, for examples.
24931 @deffn {Scheme Procedure} service-extension @var{target-type} @
24933 Return a new extension for services of type @var{target-type}.
24934 @var{compute} must be a one-argument procedure: @code{fold-services}
24935 calls it, passing it the value associated with the service that provides
24936 the extension; it must return a valid value for the target service.
24939 @deffn {Scheme Procedure} service-extension? @var{obj}
24940 Return true if @var{obj} is a service extension.
24943 Occasionally, you might want to simply extend an existing service. This
24944 involves creating a new service type and specifying the extension of
24945 interest, which can be verbose; the @code{simple-service} procedure
24946 provides a shorthand for this.
24948 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
24949 Return a service that extends @var{target} with @var{value}. This works
24950 by creating a singleton service type @var{name}, of which the returned
24951 service is an instance.
24953 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
24957 (simple-service 'my-mcron-job mcron-service-type
24958 #~(job '(next-hour (3)) "guix gc -F 2G"))
24962 At the core of the service abstraction lies the @code{fold-services}
24963 procedure, which is responsible for ``compiling'' a list of services
24964 down to a single directory that contains everything needed to boot and
24965 run the system---the directory shown by the @command{guix system build}
24966 command (@pxref{Invoking guix system}). In essence, it propagates
24967 service extensions down the service graph, updating each node parameters
24968 on the way, until it reaches the root node.
24970 @deffn {Scheme Procedure} fold-services @var{services} @
24971 [#:target-type @var{system-service-type}]
24972 Fold @var{services} by propagating their extensions down to the root of
24973 type @var{target-type}; return the root service adjusted accordingly.
24976 Lastly, the @code{(gnu services)} module also defines several essential
24977 service types, some of which are listed below.
24979 @defvr {Scheme Variable} system-service-type
24980 This is the root of the service graph. It produces the system directory
24981 as returned by the @command{guix system build} command.
24984 @defvr {Scheme Variable} boot-service-type
24985 The type of the ``boot service'', which produces the @dfn{boot script}.
24986 The boot script is what the initial RAM disk runs when booting.
24989 @defvr {Scheme Variable} etc-service-type
24990 The type of the @file{/etc} service. This service is used to create
24991 files under @file{/etc} and can be extended by
24992 passing it name/file tuples such as:
24995 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
24998 In this example, the effect would be to add an @file{/etc/issue} file
24999 pointing to the given file.
25002 @defvr {Scheme Variable} setuid-program-service-type
25003 Type for the ``setuid-program service''. This service collects lists of
25004 executable file names, passed as gexps, and adds them to the set of
25005 setuid-root programs on the system (@pxref{Setuid Programs}).
25008 @defvr {Scheme Variable} profile-service-type
25009 Type of the service that populates the @dfn{system profile}---i.e., the
25010 programs under @file{/run/current-system/profile}. Other services can
25011 extend it by passing it lists of packages to add to the system profile.
25015 @node Shepherd Services
25016 @subsection Shepherd Services
25018 @cindex shepherd services
25020 @cindex init system
25021 The @code{(gnu services shepherd)} module provides a way to define
25022 services managed by the GNU@tie{}Shepherd, which is the
25023 initialization system---the first process that is started when the
25024 system boots, also known as PID@tie{}1
25025 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
25027 Services in the Shepherd can depend on each other. For instance, the
25028 SSH daemon may need to be started after the syslog daemon has been
25029 started, which in turn can only happen once all the file systems have
25030 been mounted. The simple operating system defined earlier (@pxref{Using
25031 the Configuration System}) results in a service graph like this:
25033 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
25035 You can actually generate such a graph for any operating system
25036 definition using the @command{guix system shepherd-graph} command
25037 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
25039 The @var{%shepherd-root-service} is a service object representing
25040 PID@tie{}1, of type @var{shepherd-root-service-type}; it can be extended
25041 by passing it lists of @code{<shepherd-service>} objects.
25043 @deftp {Data Type} shepherd-service
25044 The data type representing a service managed by the Shepherd.
25047 @item @code{provision}
25048 This is a list of symbols denoting what the service provides.
25050 These are the names that may be passed to @command{herd start},
25051 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
25052 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
25053 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
25055 @item @code{requirements} (default: @code{'()})
25056 List of symbols denoting the Shepherd services this one depends on.
25058 @item @code{respawn?} (default: @code{#t})
25059 Whether to restart the service when it stops, for instance when the
25060 underlying process dies.
25063 @itemx @code{stop} (default: @code{#~(const #f)})
25064 The @code{start} and @code{stop} fields refer to the Shepherd's
25065 facilities to start and stop processes (@pxref{Service De- and
25066 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
25067 G-expressions that get expanded in the Shepherd configuration file
25068 (@pxref{G-Expressions}).
25070 @item @code{actions} (default: @code{'()})
25071 @cindex actions, of Shepherd services
25072 This is a list of @code{shepherd-action} objects (see below) defining
25073 @dfn{actions} supported by the service, in addition to the standard
25074 @code{start} and @code{stop} actions. Actions listed here become available as
25075 @command{herd} sub-commands:
25078 herd @var{action} @var{service} [@var{arguments}@dots{}]
25081 @item @code{documentation}
25082 A documentation string, as shown when running:
25085 herd doc @var{service-name}
25088 where @var{service-name} is one of the symbols in @var{provision}
25089 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
25091 @item @code{modules} (default: @var{%default-modules})
25092 This is the list of modules that must be in scope when @code{start} and
25093 @code{stop} are evaluated.
25098 @deftp {Data Type} shepherd-action
25099 This is the data type that defines additional actions implemented by a
25100 Shepherd service (see above).
25104 Symbol naming the action.
25106 @item documentation
25107 This is a documentation string for the action. It can be viewed by running:
25110 herd doc @var{service} action @var{action}
25114 This should be a gexp that evaluates to a procedure of at least one argument,
25115 which is the ``running value'' of the service (@pxref{Slots of services,,,
25116 shepherd, The GNU Shepherd Manual}).
25119 The following example defines an action called @code{say-hello} that kindly
25125 (documentation "Say hi!")
25126 (procedure #~(lambda (running . args)
25127 (format #t "Hello, friend! arguments: ~s\n"
25132 Assuming this action is added to the @code{example} service, then you can do:
25135 # herd say-hello example
25136 Hello, friend! arguments: ()
25137 # herd say-hello example a b c
25138 Hello, friend! arguments: ("a" "b" "c")
25141 This, as you can see, is a fairly sophisticated way to say hello.
25142 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
25146 @defvr {Scheme Variable} shepherd-root-service-type
25147 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
25149 This is the service type that extensions target when they want to create
25150 shepherd services (@pxref{Service Types and Services}, for an example).
25151 Each extension must pass a list of @code{<shepherd-service>}.
25154 @defvr {Scheme Variable} %shepherd-root-service
25155 This service represents PID@tie{}1.
25159 @node Documentation
25160 @chapter Documentation
25162 @cindex documentation, searching for
25163 @cindex searching for documentation
25164 @cindex Info, documentation format
25166 @cindex manual pages
25167 In most cases packages installed with Guix come with documentation.
25168 There are two main documentation formats: ``Info'', a browseable
25169 hypertext format used for GNU software, and ``manual pages'' (or ``man
25170 pages''), the linear documentation format traditionally found on Unix.
25171 Info manuals are accessed with the @command{info} command or with Emacs,
25172 and man pages are accessed using @command{man}.
25174 You can look for documentation of software installed on your system by
25175 keyword. For example, the following command searches for information
25176 about ``TLS'' in Info manuals:
25180 "(emacs)Network Security" -- STARTTLS
25181 "(emacs)Network Security" -- TLS
25182 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
25183 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
25188 The command below searches for the same keyword in man pages:
25192 SSL (7) - OpenSSL SSL/TLS library
25193 certtool (1) - GnuTLS certificate tool
25197 These searches are purely local to your computer so you have the
25198 guarantee that documentation you find corresponds to what you have
25199 actually installed, you can access it off-line, and your privacy is
25202 Once you have these results, you can view the relevant documentation by
25206 $ info "(gnutls)Core TLS API"
25216 Info manuals contain sections and indices as well as hyperlinks like
25217 those found in Web pages. The @command{info} reader (@pxref{Top, Info
25218 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
25219 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
25220 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
25221 Introduction}, for an introduction to Info navigation.
25223 @node Installing Debugging Files
25224 @chapter Installing Debugging Files
25226 @cindex debugging files
25227 Program binaries, as produced by the GCC compilers for instance, are
25228 typically written in the ELF format, with a section containing
25229 @dfn{debugging information}. Debugging information is what allows the
25230 debugger, GDB, to map binary code to source code; it is required to
25231 debug a compiled program in good conditions.
25233 The problem with debugging information is that is takes up a fair amount
25234 of disk space. For example, debugging information for the GNU C Library
25235 weighs in at more than 60 MiB. Thus, as a user, keeping all the
25236 debugging info of all the installed programs is usually not an option.
25237 Yet, space savings should not come at the cost of an impediment to
25238 debugging---especially in the GNU system, which should make it easier
25239 for users to exert their computing freedom (@pxref{GNU Distribution}).
25241 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
25242 mechanism that allows users to get the best of both worlds: debugging
25243 information can be stripped from the binaries and stored in separate
25244 files. GDB is then able to load debugging information from those files,
25245 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
25248 The GNU distribution takes advantage of this by storing debugging
25249 information in the @code{lib/debug} sub-directory of a separate package
25250 output unimaginatively called @code{debug} (@pxref{Packages with
25251 Multiple Outputs}). Users can choose to install the @code{debug} output
25252 of a package when they need it. For instance, the following command
25253 installs the debugging information for the GNU C Library and for GNU
25257 guix package -i glibc:debug guile:debug
25260 GDB must then be told to look for debug files in the user's profile, by
25261 setting the @code{debug-file-directory} variable (consider setting it
25262 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
25266 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
25269 From there on, GDB will pick up debugging information from the
25270 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
25272 In addition, you will most likely want GDB to be able to show the source
25273 code being debugged. To do that, you will have to unpack the source
25274 code of the package of interest (obtained with @code{guix build
25275 --source}, @pxref{Invoking guix build}), and to point GDB to that source
25276 directory using the @code{directory} command (@pxref{Source Path,
25277 @code{directory},, gdb, Debugging with GDB}).
25279 @c XXX: keep me up-to-date
25280 The @code{debug} output mechanism in Guix is implemented by the
25281 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
25282 opt-in---debugging information is available only for the packages
25283 with definitions explicitly declaring a @code{debug} output. This may be
25284 changed to opt-out in the future if our build farm servers can handle
25285 the load. To check whether a package has a @code{debug} output, use
25286 @command{guix package --list-available} (@pxref{Invoking guix package}).
25289 @node Security Updates
25290 @chapter Security Updates
25292 @cindex security updates
25293 @cindex security vulnerabilities
25294 Occasionally, important security vulnerabilities are discovered in software
25295 packages and must be patched. Guix developers try hard to keep track of
25296 known vulnerabilities and to apply fixes as soon as possible in the
25297 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
25298 containing only security updates.) The @command{guix lint} tool helps
25299 developers find out about vulnerable versions of software packages in the
25304 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
25305 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
25306 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
25310 @xref{Invoking guix lint}, for more information.
25313 As of version @value{VERSION}, the feature described below is considered
25317 Guix follows a functional
25318 package management discipline (@pxref{Introduction}), which implies
25319 that, when a package is changed, @emph{every package that depends on it}
25320 must be rebuilt. This can significantly slow down the deployment of
25321 fixes in core packages such as libc or Bash, since basically the whole
25322 distribution would need to be rebuilt. Using pre-built binaries helps
25323 (@pxref{Substitutes}), but deployment may still take more time than
25327 To address this, Guix implements @dfn{grafts}, a mechanism that allows
25328 for fast deployment of critical updates without the costs associated
25329 with a whole-distribution rebuild. The idea is to rebuild only the
25330 package that needs to be patched, and then to ``graft'' it onto packages
25331 explicitly installed by the user and that were previously referring to
25332 the original package. The cost of grafting is typically very low, and
25333 order of magnitudes lower than a full rebuild of the dependency chain.
25335 @cindex replacements of packages, for grafts
25336 For instance, suppose a security update needs to be applied to Bash.
25337 Guix developers will provide a package definition for the ``fixed''
25338 Bash, say @var{bash-fixed}, in the usual way (@pxref{Defining
25339 Packages}). Then, the original package definition is augmented with a
25340 @code{replacement} field pointing to the package containing the bug fix:
25347 (replacement bash-fixed)))
25350 From there on, any package depending directly or indirectly on Bash---as
25351 reported by @command{guix gc --requisites} (@pxref{Invoking guix
25352 gc})---that is installed is automatically ``rewritten'' to refer to
25353 @var{bash-fixed} instead of @var{bash}. This grafting process takes
25354 time proportional to the size of the package, usually less than a
25355 minute for an ``average'' package on a recent machine. Grafting is
25356 recursive: when an indirect dependency requires grafting, then grafting
25357 ``propagates'' up to the package that the user is installing.
25359 Currently, the length of the name and version of the graft and that of
25360 the package it replaces (@var{bash-fixed} and @var{bash} in the example
25361 above) must be equal. This restriction mostly comes from the fact that
25362 grafting works by patching files, including binary files, directly.
25363 Other restrictions may apply: for instance, when adding a graft to a
25364 package providing a shared library, the original shared library and its
25365 replacement must have the same @code{SONAME} and be binary-compatible.
25367 The @option{--no-grafts} command-line option allows you to forcefully
25368 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
25372 guix build bash --no-grafts
25376 returns the store file name of the original Bash, whereas:
25383 returns the store file name of the ``fixed'', replacement Bash. This
25384 allows you to distinguish between the two variants of Bash.
25386 To verify which Bash your whole profile refers to, you can run
25387 (@pxref{Invoking guix gc}):
25390 guix gc -R `readlink -f ~/.guix-profile` | grep bash
25394 @dots{} and compare the store file names that you get with those above.
25395 Likewise for a complete Guix system generation:
25398 guix gc -R `guix system build my-config.scm` | grep bash
25401 Lastly, to check which Bash running processes are using, you can use the
25402 @command{lsof} command:
25405 lsof | grep /gnu/store/.*bash
25409 @node Bootstrapping
25410 @chapter Bootstrapping
25412 @c Adapted from the ELS 2013 paper.
25414 @cindex bootstrapping
25416 Bootstrapping in our context refers to how the distribution gets built
25417 ``from nothing''. Remember that the build environment of a derivation
25418 contains nothing but its declared inputs (@pxref{Introduction}). So
25419 there's an obvious chicken-and-egg problem: how does the first package
25420 get built? How does the first compiler get compiled? Note that this is
25421 a question of interest only to the curious hacker, not to the regular
25422 user, so you can shamelessly skip this section if you consider yourself
25423 a ``regular user''.
25425 @cindex bootstrap binaries
25426 The GNU system is primarily made of C code, with libc at its core. The
25427 GNU build system itself assumes the availability of a Bourne shell and
25428 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
25429 `grep'. Furthermore, build programs---programs that run
25430 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
25431 (@pxref{Derivations}). Consequently, to be able to build anything at
25432 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
25433 Binutils, libc, and the other packages mentioned above---the
25434 @dfn{bootstrap binaries}.
25436 These bootstrap binaries are ``taken for granted'', though we can also
25437 re-create them if needed (more on that later).
25439 @unnumberedsec Preparing to Use the Bootstrap Binaries
25441 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
25442 @c large image, it's hard to scroll. Oh well.
25443 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
25445 The figure above shows the very beginning of the dependency graph of the
25446 distribution, corresponding to the package definitions of the @code{(gnu
25447 packages bootstrap)} module. A similar figure can be generated with
25448 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
25451 guix graph -t derivation \
25452 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
25456 At this level of detail, things are
25457 slightly complex. First, Guile itself consists of an ELF executable,
25458 along with many source and compiled Scheme files that are dynamically
25459 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
25460 tarball shown in this graph. This tarball is part of Guix's ``source''
25461 distribution, and gets inserted into the store with @code{add-to-store}
25462 (@pxref{The Store}).
25464 But how do we write a derivation that unpacks this tarball and adds it
25465 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
25466 derivation---the first one that gets built---uses @code{bash} as its
25467 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
25468 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
25469 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
25470 the Guix source distribution, whose sole purpose is to allow the Guile
25471 tarball to be unpacked.
25473 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
25474 Guile that can be used to run subsequent build programs. Its first task
25475 is to download tarballs containing the other pre-built binaries---this
25476 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
25477 @code{ftp-client.scm} are used for this purpose. The
25478 @code{module-import.drv} derivations import those modules in a directory
25479 in the store, using the original layout. The
25480 @code{module-import-compiled.drv} derivations compile those modules, and
25481 write them in an output directory with the right layout. This
25482 corresponds to the @code{#:modules} argument of
25483 @code{build-expression->derivation} (@pxref{Derivations}).
25485 Finally, the various tarballs are unpacked by the
25486 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
25487 etc., at which point we have a working C tool chain.
25490 @unnumberedsec Building the Build Tools
25492 Bootstrapping is complete when we have a full tool chain that does not
25493 depend on the pre-built bootstrap tools discussed above. This
25494 no-dependency requirement is verified by checking whether the files of
25495 the final tool chain contain references to the @file{/gnu/store}
25496 directories of the bootstrap inputs. The process that leads to this
25497 ``final'' tool chain is described by the package definitions found in
25498 the @code{(gnu packages commencement)} module.
25500 The @command{guix graph} command allows us to ``zoom out'' compared to
25501 the graph above, by looking at the level of package objects instead of
25502 individual derivations---remember that a package may translate to
25503 several derivations, typically one derivation to download its source,
25504 one to build the Guile modules it needs, and one to actually build the
25505 package from source. The command:
25508 guix graph -t bag \
25509 -e '(@@@@ (gnu packages commencement)
25510 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
25514 produces the dependency graph leading to the ``final'' C
25515 library@footnote{You may notice the @code{glibc-intermediate} label,
25516 suggesting that it is not @emph{quite} final, but as a good
25517 approximation, we will consider it final.}, depicted below.
25519 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
25521 @c See <http://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
25522 The first tool that gets built with the bootstrap binaries is
25523 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
25524 for all the following packages. From there Findutils and Diffutils get
25527 Then come the first-stage Binutils and GCC, built as pseudo cross
25528 tools---i.e., with @code{--target} equal to @code{--host}. They are
25529 used to build libc. Thanks to this cross-build trick, this libc is
25530 guaranteed not to hold any reference to the initial tool chain.
25532 From there the final Binutils and GCC (not shown above) are built.
25534 from the final Binutils, and links programs against the just-built libc.
25535 This tool chain is used to build the other packages used by Guix and by
25536 the GNU Build System: Guile, Bash, Coreutils, etc.
25538 And voilà! At this point we have the complete set of build tools that
25539 the GNU Build System expects. These are in the @code{%final-inputs}
25540 variable of the @code{(gnu packages commencement)} module, and are
25541 implicitly used by any package that uses @code{gnu-build-system}
25542 (@pxref{Build Systems, @code{gnu-build-system}}).
25545 @unnumberedsec Building the Bootstrap Binaries
25547 @cindex bootstrap binaries
25548 Because the final tool chain does not depend on the bootstrap binaries,
25549 those rarely need to be updated. Nevertheless, it is useful to have an
25550 automated way to produce them, should an update occur, and this is what
25551 the @code{(gnu packages make-bootstrap)} module provides.
25553 The following command builds the tarballs containing the bootstrap
25554 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
25555 of Coreutils and other basic command-line tools):
25558 guix build bootstrap-tarballs
25561 The generated tarballs are those that should be referred to in the
25562 @code{(gnu packages bootstrap)} module mentioned at the beginning of
25565 Still here? Then perhaps by now you've started to wonder: when do we
25566 reach a fixed point? That is an interesting question! The answer is
25567 unknown, but if you would like to investigate further (and have
25568 significant computational and storage resources to do so), then let us
25571 @unnumberedsec Reducing the Set of Bootstrap Binaries
25573 Our bootstrap binaries currently include GCC, Guile, etc. That's a lot
25574 of binary code! Why is that a problem? It's a problem because these
25575 big chunks of binary code are practically non-auditable, which makes it
25576 hard to establish what source code produced them. Every unauditable
25577 binary also leaves us vulnerable to compiler backdoors as described by
25578 Ken Thompson in the 1984 paper @emph{Reflections on Trusting Trust}.
25580 This is mitigated by the fact that our bootstrap binaries were generated
25581 from an earlier Guix revision. Nevertheless it lacks the level of
25582 transparency that we get in the rest of the package dependency graph,
25583 where Guix always gives us a source-to-binary mapping. Thus, our goal
25584 is to reduce the set of bootstrap binaries to the bare minimum.
25586 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
25587 on-going projects to do that. One of these is about replacing the
25588 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
25589 of increasing complexity, which could be built from source starting from
25590 a simple and auditable assembler. Your help is welcome!
25594 @chapter Porting to a New Platform
25596 As discussed above, the GNU distribution is self-contained, and
25597 self-containment is achieved by relying on pre-built ``bootstrap
25598 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
25599 operating system kernel, CPU architecture, and application binary
25600 interface (ABI). Thus, to port the distribution to a platform that is
25601 not yet supported, one must build those bootstrap binaries, and update
25602 the @code{(gnu packages bootstrap)} module to use them on that platform.
25604 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
25605 When everything goes well, and assuming the GNU tool chain supports the
25606 target platform, this can be as simple as running a command like this
25610 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
25613 For this to work, the @code{glibc-dynamic-linker} procedure in
25614 @code{(gnu packages bootstrap)} must be augmented to return the right
25615 file name for libc's dynamic linker on that platform; likewise,
25616 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
25617 taught about the new platform.
25619 Once these are built, the @code{(gnu packages bootstrap)} module needs
25620 to be updated to refer to these binaries on the target platform. That
25621 is, the hashes and URLs of the bootstrap tarballs for the new platform
25622 must be added alongside those of the currently supported platforms. The
25623 bootstrap Guile tarball is treated specially: it is expected to be
25624 available locally, and @file{gnu/local.mk} has rules to download it for
25625 the supported architectures; a rule for the new platform must be added
25628 In practice, there may be some complications. First, it may be that the
25629 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
25630 above) is not recognized by all the GNU tools. Typically, glibc
25631 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
25632 configure flag (see @code{gcc.scm} for examples of how to handle this).
25633 Second, some of the required packages could fail to build for that
25634 platform. Lastly, the generated binaries could be broken for some
25637 @c *********************************************************************
25638 @include contributing.texi
25640 @c *********************************************************************
25641 @node Acknowledgments
25642 @chapter Acknowledgments
25644 Guix is based on the @uref{http://nixos.org/nix/, Nix package manager},
25645 which was designed and
25646 implemented by Eelco Dolstra, with contributions from other people (see
25647 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
25648 management, and promoted unprecedented features, such as transactional
25649 package upgrades and rollbacks, per-user profiles, and referentially
25650 transparent build processes. Without this work, Guix would not exist.
25652 The Nix-based software distributions, Nixpkgs and NixOS, have also been
25653 an inspiration for Guix.
25655 GNU@tie{}Guix itself is a collective work with contributions from a
25656 number of people. See the @file{AUTHORS} file in Guix for more
25657 information on these fine people. The @file{THANKS} file lists people
25658 who have helped by reporting bugs, taking care of the infrastructure,
25659 providing artwork and themes, making suggestions, and more---thank you!
25662 @c *********************************************************************
25663 @node GNU Free Documentation License
25664 @appendix GNU Free Documentation License
25665 @cindex license, GNU Free Documentation License
25666 @include fdl-1.3.texi
25668 @c *********************************************************************
25669 @node Concept Index
25670 @unnumbered Concept Index
25673 @node Programming Index
25674 @unnumbered Programming Index
25675 @syncodeindex tp fn
25676 @syncodeindex vr fn
25681 @c Local Variables:
25682 @c ispell-local-dictionary: "american";