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 * Locales:: Language and cultural convention settings.
255 * Services:: Specifying system services.
256 * Setuid Programs:: Programs running with root privileges.
257 * X.509 Certificates:: Authenticating HTTPS servers.
258 * Name Service Switch:: Configuring libc's name service switch.
259 * Initial RAM Disk:: Linux-Libre bootstrapping.
260 * Bootloader Configuration:: Configuring the boot loader.
261 * Invoking guix system:: Instantiating a system configuration.
262 * Running Guix in a VM:: How to run Guix System in a virtual machine.
263 * Defining Services:: Adding new service definitions.
267 * Base Services:: Essential system services.
268 * Scheduled Job Execution:: The mcron service.
269 * Log Rotation:: The rottlog service.
270 * Networking Services:: Network setup, SSH daemon, etc.
271 * X Window:: Graphical display.
272 * Printing Services:: Local and remote printer support.
273 * Desktop Services:: D-Bus and desktop services.
274 * Sound Services:: ALSA and Pulseaudio services.
275 * Database Services:: SQL databases, key-value stores, etc.
276 * Mail Services:: IMAP, POP3, SMTP, and all that.
277 * Messaging Services:: Messaging services.
278 * Telephony Services:: Telephony services.
279 * Monitoring Services:: Monitoring services.
280 * Kerberos Services:: Kerberos services.
281 * Web Services:: Web servers.
282 * Certificate Services:: TLS certificates via Let's Encrypt.
283 * DNS Services:: DNS daemons.
284 * VPN Services:: VPN daemons.
285 * Network File System:: NFS related services.
286 * Continuous Integration:: The Cuirass service.
287 * Power Management Services:: Extending battery life.
288 * Audio Services:: The MPD.
289 * Virtualization Services:: Virtualization services.
290 * Version Control Services:: Providing remote access to Git repositories.
291 * Game Services:: Game servers.
292 * Miscellaneous Services:: Other services.
296 * Service Composition:: The model for composing services.
297 * Service Types and Services:: Types and services.
298 * Service Reference:: API reference.
299 * Shepherd Services:: A particular type of service.
304 @c *********************************************************************
306 @chapter Introduction
309 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
310 using the international phonetic alphabet (IPA).} is a package
311 management tool for and distribution of the GNU system.
312 Guix makes it easy for unprivileged
313 users to install, upgrade, or remove software packages, to roll back to a
314 previous package set, to build packages from source, and generally
315 assists with the creation and maintenance of software environments.
318 @cindex GuixSD, now Guix System
319 @cindex Guix System Distribution, now Guix System
320 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
321 complements the available tools without interference (@pxref{Installation}),
322 or you can use it as a standalone operating system distribution,
323 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
324 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
325 group everything under the ``Guix'' banner since, after all, Guix System is
326 readily available through the @command{guix system} command, even if you're
327 using a different distro underneath!}. @xref{GNU Distribution}.
330 * Managing Software the Guix Way:: What's special.
331 * GNU Distribution:: The packages and tools.
334 @node Managing Software the Guix Way
335 @section Managing Software the Guix Way
337 @cindex user interfaces
338 Guix provides a command-line package management interface
339 (@pxref{Package Management}), tools to help with software development
340 (@pxref{Development}), command-line utilities for more advanced usage,
341 (@pxref{Utilities}), as well as Scheme programming interfaces
342 (@pxref{Programming Interface}).
344 Its @dfn{build daemon} is responsible for building packages on behalf of
345 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
346 binaries from authorized sources (@pxref{Substitutes}).
348 @cindex extensibility of the distribution
349 @cindex customization, of packages
350 Guix includes package definitions for many GNU and non-GNU packages, all
351 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
352 user's computing freedom}. It is @emph{extensible}: users can write
353 their own package definitions (@pxref{Defining Packages}) and make them
354 available as independent package modules (@pxref{Package Modules}). It
355 is also @emph{customizable}: users can @emph{derive} specialized package
356 definitions from existing ones, including from the command line
357 (@pxref{Package Transformation Options}).
359 @cindex functional package management
361 Under the hood, Guix implements the @dfn{functional package management}
362 discipline pioneered by Nix (@pxref{Acknowledgments}).
363 In Guix, the package build and installation process is seen
364 as a @emph{function}, in the mathematical sense. That function takes inputs,
365 such as build scripts, a compiler, and libraries, and
366 returns an installed package. As a pure function, its result depends
367 solely on its inputs---for instance, it cannot refer to software or
368 scripts that were not explicitly passed as inputs. A build function
369 always produces the same result when passed a given set of inputs. It
370 cannot alter the environment of the running system in
371 any way; for instance, it cannot create, modify, or delete files outside
372 of its build and installation directories. This is achieved by running
373 build processes in isolated environments (or @dfn{containers}), where only their
374 explicit inputs are visible.
377 The result of package build functions is @dfn{cached} in the file
378 system, in a special directory called @dfn{the store} (@pxref{The
379 Store}). Each package is installed in a directory of its own in the
380 store---by default under @file{/gnu/store}. The directory name contains
381 a hash of all the inputs used to build that package; thus, changing an
382 input yields a different directory name.
384 This approach is the foundation for the salient features of Guix: support
385 for transactional package upgrade and rollback, per-user installation, and
386 garbage collection of packages (@pxref{Features}).
389 @node GNU Distribution
390 @section GNU Distribution
393 Guix comes with a distribution of the GNU system consisting entirely of
394 free software@footnote{The term ``free'' here refers to the
395 @url{http://www.gnu.org/philosophy/free-sw.html,freedom provided to
396 users of that software}.}. The
397 distribution can be installed on its own (@pxref{System Installation}),
398 but it is also possible to install Guix as a package manager on top of
399 an installed GNU/Linux system (@pxref{Installation}). When we need to
400 distinguish between the two, we refer to the standalone distribution as
403 The distribution provides core GNU packages such as GNU libc, GCC, and
404 Binutils, as well as many GNU and non-GNU applications. The complete
405 list of available packages can be browsed
406 @url{http://www.gnu.org/software/guix/packages,on-line} or by
407 running @command{guix package} (@pxref{Invoking guix package}):
410 guix package --list-available
413 Our goal is to provide a practical 100% free software distribution of
414 Linux-based and other variants of GNU, with a focus on the promotion and
415 tight integration of GNU components, and an emphasis on programs and
416 tools that help users exert that freedom.
418 Packages are currently available on the following platforms:
423 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
426 Intel 32-bit architecture (IA32), Linux-Libre kernel;
429 ARMv7-A architecture with hard float, Thumb-2 and NEON,
430 using the EABI hard-float application binary interface (ABI),
431 and Linux-Libre kernel.
434 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel. This is
435 currently in an experimental stage, with limited support.
436 @xref{Contributing}, for how to help!
439 little-endian 64-bit MIPS processors, specifically the Loongson series,
440 n32 ABI, and Linux-Libre kernel.
444 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
445 configuration and Guix takes care of instantiating the configuration in a
446 transactional, reproducible, and stateless fashion (@pxref{System
447 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
448 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
449 Manual}), the well-known GNU utilities and tool chain, as well as the
450 graphical environment or system services of your choice.
452 Guix System is available on all the above platforms except
453 @code{mips64el-linux}.
456 For information on porting to other architectures or kernels,
459 Building this distribution is a cooperative effort, and you are invited
460 to join! @xref{Contributing}, for information about how you can help.
463 @c *********************************************************************
465 @chapter Installation
467 @cindex installing Guix
470 We recommend the use of this
471 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
472 shell installer script} to install Guix on top of a running GNU/Linux system,
473 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
474 with the installation of the package manager, which can be done on top of a
475 running GNU/Linux system. If, instead, you want to install the complete GNU
476 operating system, @pxref{System Installation}.} The script automates the
477 download, installation, and initial configuration of Guix. It should be run
481 @cindex foreign distro
482 @cindex directories related to foreign distro
483 When installed on a foreign distro, GNU@tie{}Guix complements the available
484 tools without interference. Its data lives exclusively in two directories,
485 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
486 such as @file{/etc}, are left untouched.
488 Once installed, Guix can be updated by running @command{guix pull}
489 (@pxref{Invoking guix pull}).
491 If you prefer to perform the installation steps manually or want to tweak
492 them, you may find the following subsections useful. They describe the
493 software requirements of Guix, as well as how to install it manually and get
497 * Binary Installation:: Getting Guix running in no time!
498 * Requirements:: Software needed to build and run Guix.
499 * Running the Test Suite:: Testing Guix.
500 * Setting Up the Daemon:: Preparing the build daemon's environment.
501 * Invoking guix-daemon:: Running the build daemon.
502 * Application Setup:: Application-specific setup.
505 @node Binary Installation
506 @section Binary Installation
508 @cindex installing Guix from binaries
509 @cindex installer script
510 This section describes how to install Guix on an arbitrary system from a
511 self-contained tarball providing binaries for Guix and for all its
512 dependencies. This is often quicker than installing from source, which
513 is described in the next sections. The only requirement is to have
516 Installing goes along these lines:
520 @cindex downloading Guix binary
521 Download the binary tarball from
522 @indicateurl{https://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz},
523 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
524 already running the kernel Linux, and so on.
526 @c The following is somewhat duplicated in ``System Installation''.
527 Make sure to download the associated @file{.sig} file and to verify the
528 authenticity of the tarball against it, along these lines:
531 $ wget https://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
532 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
535 If that command fails because you do not have the required public key,
536 then run this command to import it:
539 $ gpg --keyserver @value{KEY-SERVER} \
540 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
544 and rerun the @code{gpg --verify} command.
545 @c end authentication part
548 Now, you need to become the @code{root} user. Depending on your distribution,
549 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
553 # tar --warning=no-timestamp -xf \
554 guix-binary-@value{VERSION}.@var{system}.tar.xz
555 # mv var/guix /var/ && mv gnu /
558 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
559 The latter contains a ready-to-use profile for @code{root} (see next
562 Do @emph{not} unpack the tarball on a working Guix system since that
563 would overwrite its own essential files.
565 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
566 not emit warnings about ``implausibly old time stamps'' (such
567 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
569 They stem from the fact that all the
570 files in the archive have their modification time set to zero (which
571 means January 1st, 1970.) This is done on purpose to make sure the
572 archive content is independent of its creation time, thus making it
576 Make the profile available under @file{~root/.config/guix/current}, which is
577 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
580 # mkdir -p ~root/.config/guix
581 # ln -sf /var/guix/profiles/per-user/root/current-guix \
582 ~root/.config/guix/current
585 Source @file{etc/profile} to augment @code{PATH} and other relevant
586 environment variables:
589 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
590 source $GUIX_PROFILE/etc/profile
594 Create the group and user accounts for build users as explained below
595 (@pxref{Build Environment Setup}).
598 Run the daemon, and set it to automatically start on boot.
600 If your host distro uses the systemd init system, this can be achieved
603 @c Versions of systemd that supported symlinked service files are not
604 @c yet widely deployed, so we should suggest that users copy the service
607 @c See this thread for more information:
608 @c http://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
611 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
613 # systemctl start guix-daemon && systemctl enable guix-daemon
616 If your host distro uses the Upstart init system:
619 # initctl reload-configuration
620 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
625 Otherwise, you can still start the daemon manually with:
628 # ~root/.config/guix/current/bin/guix-daemon \
629 --build-users-group=guixbuild
633 Make the @command{guix} command available to other users on the machine,
637 # mkdir -p /usr/local/bin
639 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
642 It is also a good idea to make the Info version of this manual available
646 # mkdir -p /usr/local/share/info
647 # cd /usr/local/share/info
648 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
652 That way, assuming @file{/usr/local/share/info} is in the search path,
653 running @command{info guix} will open this manual (@pxref{Other Info
654 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
658 @cindex substitutes, authorization thereof
659 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
660 (@pxref{Substitutes}), authorize them:
663 # guix archive --authorize < \
664 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
668 Each user may need to perform a few additional steps to make their Guix
669 environment ready for use, @pxref{Application Setup}.
672 Voilà, the installation is complete!
674 You can confirm that Guix is working by installing a sample package into
678 # guix package -i hello
681 The @code{guix} package must remain available in @code{root}'s profile,
682 or it would become subject to garbage collection---in which case you
683 would find yourself badly handicapped by the lack of the @command{guix}
684 command. In other words, do not remove @code{guix} by running
685 @code{guix package -r guix}.
687 The binary installation tarball can be (re)produced and verified simply
688 by running the following command in the Guix source tree:
691 make guix-binary.@var{system}.tar.xz
695 ...@: which, in turn, runs:
698 guix pack -s @var{system} --localstatedir \
699 --profile-name=current-guix guix
702 @xref{Invoking guix pack}, for more info on this handy tool.
705 @section Requirements
707 This section lists requirements when building Guix from source. The
708 build procedure for Guix is the same as for other GNU software, and is
709 not covered here. Please see the files @file{README} and @file{INSTALL}
710 in the Guix source tree for additional details.
712 @cindex official website
713 GNU Guix is available for download from its website at
714 @url{https://www.gnu.org/software/guix/}.
716 GNU Guix depends on the following packages:
719 @item @url{http://gnu.org/software/guile/, GNU Guile}, version 2.2.x;
720 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
723 @uref{http://gnutls.org/, GnuTLS}, specifically its Guile bindings
724 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
725 Guile,, gnutls-guile, GnuTLS-Guile});
727 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
730 @c FIXME: Specify a version number once a release has been made.
731 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
733 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON};
734 @item @url{http://zlib.net, zlib};
735 @item @url{http://www.gnu.org/software/make/, GNU Make}.
738 The following dependencies are optional:
742 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
743 Support for build offloading (@pxref{Daemon Offload Setup}) and
744 @command{guix copy} (@pxref{Invoking guix copy}) depends on
745 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
746 version 0.10.2 or later.
749 When @url{http://www.bzip.org, libbz2} is available,
750 @command{guix-daemon} can use it to compress build logs.
753 Unless @code{--disable-daemon} was passed to @command{configure}, the
754 following packages are also needed:
757 @item @url{http://gnupg.org/, GNU libgcrypt};
758 @item @url{http://sqlite.org, SQLite 3};
759 @item @url{http://gcc.gnu.org, GCC's g++}, with support for the
763 @cindex state directory
764 When configuring Guix on a system that already has a Guix installation,
765 be sure to specify the same state directory as the existing installation
766 using the @code{--localstatedir} option of the @command{configure}
767 script (@pxref{Directory Variables, @code{localstatedir},, standards,
768 GNU Coding Standards}). The @command{configure} script protects against
769 unintended misconfiguration of @var{localstatedir} so you do not
770 inadvertently corrupt your store (@pxref{The Store}).
772 @cindex Nix, compatibility
773 When a working installation of @url{http://nixos.org/nix/, the Nix package
774 manager} is available, you
775 can instead configure Guix with @code{--disable-daemon}. In that case,
776 Nix replaces the three dependencies above.
778 Guix is compatible with Nix, so it is possible to share the same store
779 between both. To do so, you must pass @command{configure} not only the
780 same @code{--with-store-dir} value, but also the same
781 @code{--localstatedir} value. The latter is essential because it
782 specifies where the database that stores metadata about the store is
783 located, among other things. The default values for Nix are
784 @code{--with-store-dir=/nix/store} and @code{--localstatedir=/nix/var}.
785 Note that @code{--disable-daemon} is not required if
786 your goal is to share the store with Nix.
788 @node Running the Test Suite
789 @section Running the Test Suite
792 After a successful @command{configure} and @code{make} run, it is a good
793 idea to run the test suite. It can help catch issues with the setup or
794 environment, or bugs in Guix itself---and really, reporting test
795 failures is a good way to help improve the software. To run the test
802 Test cases can run in parallel: you can use the @code{-j} option of
803 GNU@tie{}make to speed things up. The first run may take a few minutes
804 on a recent machine; subsequent runs will be faster because the store
805 that is created for test purposes will already have various things in
808 It is also possible to run a subset of the tests by defining the
809 @code{TESTS} makefile variable as in this example:
812 make check TESTS="tests/store.scm tests/cpio.scm"
815 By default, tests results are displayed at a file level. In order to
816 see the details of every individual test cases, it is possible to define
817 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
820 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
823 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
824 @file{test-suite.log} file. Please specify the Guix version being used
825 as well as version numbers of the dependencies (@pxref{Requirements}) in
828 Guix also comes with a whole-system test suite that tests complete
829 Guix System instances. It can only run on systems where
830 Guix is already installed, using:
837 or, again, by defining @code{TESTS} to select a subset of tests to run:
840 make check-system TESTS="basic mcron"
843 These system tests are defined in the @code{(gnu tests @dots{})}
844 modules. They work by running the operating systems under test with
845 lightweight instrumentation in a virtual machine (VM). They can be
846 computationally intensive or rather cheap, depending on whether
847 substitutes are available for their dependencies (@pxref{Substitutes}).
848 Some of them require a lot of storage space to hold VM images.
850 Again in case of test failures, please send @email{bug-guix@@gnu.org}
853 @node Setting Up the Daemon
854 @section Setting Up the Daemon
857 Operations such as building a package or running the garbage collector
858 are all performed by a specialized process, the @dfn{build daemon}, on
859 behalf of clients. Only the daemon may access the store and its
860 associated database. Thus, any operation that manipulates the store
861 goes through the daemon. For instance, command-line tools such as
862 @command{guix package} and @command{guix build} communicate with the
863 daemon (@i{via} remote procedure calls) to instruct it what to do.
865 The following sections explain how to prepare the build daemon's
866 environment. See also @ref{Substitutes}, for information on how to allow
867 the daemon to download pre-built binaries.
870 * Build Environment Setup:: Preparing the isolated build environment.
871 * Daemon Offload Setup:: Offloading builds to remote machines.
872 * SELinux Support:: Using an SELinux policy for the daemon.
875 @node Build Environment Setup
876 @subsection Build Environment Setup
878 @cindex build environment
879 In a standard multi-user setup, Guix and its daemon---the
880 @command{guix-daemon} program---are installed by the system
881 administrator; @file{/gnu/store} is owned by @code{root} and
882 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
883 Guix tools to build packages or otherwise access the store, and the
884 daemon will do it on their behalf, ensuring that the store is kept in a
885 consistent state, and allowing built packages to be shared among users.
888 When @command{guix-daemon} runs as @code{root}, you may not want package
889 build processes themselves to run as @code{root} too, for obvious
890 security reasons. To avoid that, a special pool of @dfn{build users}
891 should be created for use by build processes started by the daemon.
892 These build users need not have a shell and a home directory: they will
893 just be used when the daemon drops @code{root} privileges in build
894 processes. Having several such users allows the daemon to launch
895 distinct build processes under separate UIDs, which guarantees that they
896 do not interfere with each other---an essential feature since builds are
897 regarded as pure functions (@pxref{Introduction}).
899 On a GNU/Linux system, a build user pool may be created like this (using
900 Bash syntax and the @code{shadow} commands):
902 @c See http://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
903 @c for why `-G' is needed.
905 # groupadd --system guixbuild
906 # for i in `seq -w 1 10`;
908 useradd -g guixbuild -G guixbuild \
909 -d /var/empty -s `which nologin` \
910 -c "Guix build user $i" --system \
916 The number of build users determines how many build jobs may run in
917 parallel, as specified by the @option{--max-jobs} option
918 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
919 @command{guix system vm} and related commands, you may need to add the
920 build users to the @code{kvm} group so they can access @file{/dev/kvm},
921 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
922 (@pxref{Invoking guix system}).
924 The @code{guix-daemon} program may then be run as @code{root} with the
925 following command@footnote{If your machine uses the systemd init system,
926 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
927 file in @file{/etc/systemd/system} will ensure that
928 @command{guix-daemon} is automatically started. Similarly, if your
929 machine uses the Upstart init system, drop the
930 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
931 file in @file{/etc/init}.}:
934 # guix-daemon --build-users-group=guixbuild
939 This way, the daemon starts build processes in a chroot, under one of
940 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
941 environment contains nothing but:
943 @c Keep this list in sync with libstore/build.cc! -----------------------
946 a minimal @code{/dev} directory, created mostly independently from the
947 host @code{/dev}@footnote{``Mostly'', because while the set of files
948 that appear in the chroot's @code{/dev} is fixed, most of these files
949 can only be created if the host has them.};
952 the @code{/proc} directory; it only shows the processes of the container
953 since a separate PID name space is used;
956 @file{/etc/passwd} with an entry for the current user and an entry for
960 @file{/etc/group} with an entry for the user's group;
963 @file{/etc/hosts} with an entry that maps @code{localhost} to
967 a writable @file{/tmp} directory.
970 You can influence the directory where the daemon stores build trees
971 @i{via} the @code{TMPDIR} environment variable. However, the build tree
972 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
973 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
974 This way, the value of @code{TMPDIR} does not leak inside build
975 environments, which avoids discrepancies in cases where build processes
976 capture the name of their build tree.
979 The daemon also honors the @code{http_proxy} environment variable for
980 HTTP downloads it performs, be it for fixed-output derivations
981 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
983 If you are installing Guix as an unprivileged user, it is still possible
984 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
985 However, build processes will not be isolated from one another, and not
986 from the rest of the system. Thus, build processes may interfere with
987 each other, and may access programs, libraries, and other files
988 available on the system---making it much harder to view them as
989 @emph{pure} functions.
992 @node Daemon Offload Setup
993 @subsection Using the Offload Facility
997 When desired, the build daemon can @dfn{offload} derivation builds to
998 other machines running Guix, using the @code{offload} @dfn{build
999 hook}@footnote{This feature is available only when
1000 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1001 present.}. When that
1002 feature is enabled, a list of user-specified build machines is read from
1003 @file{/etc/guix/machines.scm}; every time a build is requested, for
1004 instance via @code{guix build}, the daemon attempts to offload it to one
1005 of the machines that satisfy the constraints of the derivation, in
1006 particular its system type---e.g., @file{x86_64-linux}. Missing
1007 prerequisites for the build are copied over SSH to the target machine,
1008 which then proceeds with the build; upon success the output(s) of the
1009 build are copied back to the initial machine.
1011 The @file{/etc/guix/machines.scm} file typically looks like this:
1014 (list (build-machine
1015 (name "eightysix.example.org")
1016 (system "x86_64-linux")
1017 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1019 (speed 2.)) ;incredibly fast!
1022 (name "meeps.example.org")
1023 (system "mips64el-linux")
1024 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1027 (string-append (getenv "HOME")
1028 "/.ssh/identity-for-guix"))))
1032 In the example above we specify a list of two build machines, one for
1033 the @code{x86_64} architecture and one for the @code{mips64el}
1036 In fact, this file is---not surprisingly!---a Scheme file that is
1037 evaluated when the @code{offload} hook is started. Its return value
1038 must be a list of @code{build-machine} objects. While this example
1039 shows a fixed list of build machines, one could imagine, say, using
1040 DNS-SD to return a list of potential build machines discovered in the
1041 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1042 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1045 @deftp {Data Type} build-machine
1046 This data type represents build machines to which the daemon may offload
1047 builds. The important fields are:
1052 The host name of the remote machine.
1055 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1058 The user account to use when connecting to the remote machine over SSH.
1059 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1060 allow non-interactive logins.
1063 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1064 This is used to authenticate the machine when we connect to it. It is a
1065 long string that looks like this:
1068 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1071 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1072 key can be found in a file such as
1073 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1075 If the machine is running the SSH daemon of GNU@tie{}lsh,
1076 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1077 similar file. It can be converted to the OpenSSH format using
1078 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1081 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1082 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1087 A number of optional fields may be specified:
1091 @item @code{port} (default: @code{22})
1092 Port number of SSH server on the machine.
1094 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1095 The SSH private key file to use when connecting to the machine, in
1096 OpenSSH format. This key must not be protected with a passphrase.
1098 Note that the default value is the private key @emph{of the root
1099 account}. Make sure it exists if you use the default.
1101 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1102 @itemx @code{compression-level} (default: @code{3})
1103 The SSH-level compression methods and compression level requested.
1105 Note that offloading relies on SSH compression to reduce bandwidth usage
1106 when transferring files to and from build machines.
1108 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1109 File name of the Unix-domain socket @command{guix-daemon} is listening
1112 @item @code{parallel-builds} (default: @code{1})
1113 The number of builds that may run in parallel on the machine.
1115 @item @code{speed} (default: @code{1.0})
1116 A ``relative speed factor''. The offload scheduler will tend to prefer
1117 machines with a higher speed factor.
1119 @item @code{features} (default: @code{'()})
1120 A list of strings denoting specific features supported by the machine.
1121 An example is @code{"kvm"} for machines that have the KVM Linux modules
1122 and corresponding hardware support. Derivations can request features by
1123 name, and they will be scheduled on matching build machines.
1128 The @command{guix} command must be in the search path on the build
1129 machines. You can check whether this is the case by running:
1132 ssh build-machine guix repl --version
1135 There is one last thing to do once @file{machines.scm} is in place. As
1136 explained above, when offloading, files are transferred back and forth
1137 between the machine stores. For this to work, you first need to
1138 generate a key pair on each machine to allow the daemon to export signed
1139 archives of files from the store (@pxref{Invoking guix archive}):
1142 # guix archive --generate-key
1146 Each build machine must authorize the key of the master machine so that
1147 it accepts store items it receives from the master:
1150 # guix archive --authorize < master-public-key.txt
1154 Likewise, the master machine must authorize the key of each build machine.
1156 All the fuss with keys is here to express pairwise mutual trust
1157 relations between the master and the build machines. Concretely, when
1158 the master receives files from a build machine (and @i{vice versa}), its
1159 build daemon can make sure they are genuine, have not been tampered
1160 with, and that they are signed by an authorized key.
1162 @cindex offload test
1163 To test whether your setup is operational, run this command on the
1170 This will attempt to connect to each of the build machines specified in
1171 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1172 available on each machine, attempt to export to the machine and import
1173 from it, and report any error in the process.
1175 If you want to test a different machine file, just specify it on the
1179 # guix offload test machines-qualif.scm
1182 Last, you can test the subset of the machines whose name matches a
1183 regular expression like this:
1186 # guix offload test machines.scm '\.gnu\.org$'
1189 @cindex offload status
1190 To display the current load of all build hosts, run this command on the
1194 # guix offload status
1198 @node SELinux Support
1199 @subsection SELinux Support
1201 @cindex SELinux, daemon policy
1202 @cindex mandatory access control, SELinux
1203 @cindex security, guix-daemon
1204 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1205 can be installed on a system where SELinux is enabled, in order to label
1206 Guix files and to specify the expected behavior of the daemon. Since
1207 Guix System does not provide an SELinux base policy, the daemon policy cannot
1208 be used on Guix System.
1210 @subsubsection Installing the SELinux policy
1211 @cindex SELinux, policy installation
1212 To install the policy run this command as root:
1215 semodule -i etc/guix-daemon.cil
1218 Then relabel the file system with @code{restorecon} or by a different
1219 mechanism provided by your system.
1221 Once the policy is installed, the file system has been relabeled, and
1222 the daemon has been restarted, it should be running in the
1223 @code{guix_daemon_t} context. You can confirm this with the following
1227 ps -Zax | grep guix-daemon
1230 Monitor the SELinux log files as you run a command like @code{guix build
1231 hello} to convince yourself that SELinux permits all necessary
1234 @subsubsection Limitations
1235 @cindex SELinux, limitations
1237 This policy is not perfect. Here is a list of limitations or quirks
1238 that should be considered when deploying the provided SELinux policy for
1243 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1244 operations involve contexts that have anything to do with
1245 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1246 but it would be preferrable to define socket rules for only this label.
1249 @code{guix gc} cannot access arbitrary links to profiles. By design,
1250 the file label of the destination of a symlink is independent of the
1251 file label of the link itself. Although all profiles under
1252 $localstatedir are labelled, the links to these profiles inherit the
1253 label of the directory they are in. For links in the user’s home
1254 directory this will be @code{user_home_t}. But for links from the root
1255 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1256 directory, etc, this won’t work. @code{guix gc} would be prevented from
1257 reading and following these links.
1260 The daemon’s feature to listen for TCP connections might no longer work.
1261 This might require extra rules, because SELinux treats network sockets
1262 differently from files.
1265 Currently all files with a name matching the regular expression
1266 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1267 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1268 that name in any profile would be permitted to run in the
1269 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1270 build a package that provides this executable and convince a user to
1271 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1272 At that point SELinux could not prevent it from accessing files that are
1273 allowed for processes in that domain.
1275 We could generate a much more restrictive policy at installation time,
1276 so that only the @emph{exact} file name of the currently installed
1277 @code{guix-daemon} executable would be labelled with
1278 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1279 The downside is that root would have to install or upgrade the policy at
1280 installation time whenever the Guix package that provides the
1281 effectively running @code{guix-daemon} executable is upgraded.
1284 @node Invoking guix-daemon
1285 @section Invoking @command{guix-daemon}
1287 The @command{guix-daemon} program implements all the functionality to
1288 access the store. This includes launching build processes, running the
1289 garbage collector, querying the availability of a build result, etc. It
1290 is normally run as @code{root} like this:
1293 # guix-daemon --build-users-group=guixbuild
1297 For details on how to set it up, @pxref{Setting Up the Daemon}.
1300 @cindex container, build environment
1301 @cindex build environment
1302 @cindex reproducible builds
1303 By default, @command{guix-daemon} launches build processes under
1304 different UIDs, taken from the build group specified with
1305 @code{--build-users-group}. In addition, each build process is run in a
1306 chroot environment that only contains the subset of the store that the
1307 build process depends on, as specified by its derivation
1308 (@pxref{Programming Interface, derivation}), plus a set of specific
1309 system directories. By default, the latter contains @file{/dev} and
1310 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1311 @dfn{container}: in addition to having its own file system tree, it has
1312 a separate mount name space, its own PID name space, network name space,
1313 etc. This helps achieve reproducible builds (@pxref{Features}).
1315 When the daemon performs a build on behalf of the user, it creates a
1316 build directory under @file{/tmp} or under the directory specified by
1317 its @code{TMPDIR} environment variable. This directory is shared with
1318 the container for the duration of the build, though within the container,
1319 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1321 The build directory is automatically deleted upon completion, unless the
1322 build failed and the client specified @option{--keep-failed}
1323 (@pxref{Invoking guix build, @option{--keep-failed}}).
1325 The daemon listens for connections and spawns one sub-process for each session
1326 started by a client (one of the @command{guix} sub-commands.) The
1327 @command{guix processes} command allows you to get an overview of the activity
1328 on your system by viewing each of the active sessions and clients.
1329 @xref{Invoking guix processes}, for more information.
1331 The following command-line options are supported:
1334 @item --build-users-group=@var{group}
1335 Take users from @var{group} to run build processes (@pxref{Setting Up
1336 the Daemon, build users}).
1338 @item --no-substitutes
1340 Do not use substitutes for build products. That is, always build things
1341 locally instead of allowing downloads of pre-built binaries
1342 (@pxref{Substitutes}).
1344 When the daemon runs with @code{--no-substitutes}, clients can still
1345 explicitly enable substitution @i{via} the @code{set-build-options}
1346 remote procedure call (@pxref{The Store}).
1348 @item --substitute-urls=@var{urls}
1349 @anchor{daemon-substitute-urls}
1350 Consider @var{urls} the default whitespace-separated list of substitute
1351 source URLs. When this option is omitted,
1352 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1354 This means that substitutes may be downloaded from @var{urls}, as long
1355 as they are signed by a trusted signature (@pxref{Substitutes}).
1358 @item --no-build-hook
1359 Do not use the @dfn{build hook}.
1361 The build hook is a helper program that the daemon can start and to
1362 which it submits build requests. This mechanism is used to offload
1363 builds to other machines (@pxref{Daemon Offload Setup}).
1365 @item --cache-failures
1366 Cache build failures. By default, only successful builds are cached.
1368 When this option is used, @command{guix gc --list-failures} can be used
1369 to query the set of store items marked as failed; @command{guix gc
1370 --clear-failures} removes store items from the set of cached failures.
1371 @xref{Invoking guix gc}.
1373 @item --cores=@var{n}
1375 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1378 The default value is @code{0}, but it may be overridden by clients, such
1379 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1382 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1383 in the build process, which can then use it to exploit internal
1384 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1386 @item --max-jobs=@var{n}
1388 Allow at most @var{n} build jobs in parallel. The default value is
1389 @code{1}. Setting it to @code{0} means that no builds will be performed
1390 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1391 Setup}), or simply fail.
1393 @item --max-silent-time=@var{seconds}
1394 When the build or substitution process remains silent for more than
1395 @var{seconds}, terminate it and report a build failure.
1397 The default value is @code{0}, which disables the timeout.
1399 The value specified here can be overridden by clients (@pxref{Common
1400 Build Options, @code{--max-silent-time}}).
1402 @item --timeout=@var{seconds}
1403 Likewise, when the build or substitution process lasts for more than
1404 @var{seconds}, terminate it and report a build failure.
1406 The default value is @code{0}, which disables the timeout.
1408 The value specified here can be overridden by clients (@pxref{Common
1409 Build Options, @code{--timeout}}).
1411 @item --rounds=@var{N}
1412 Build each derivation @var{n} times in a row, and raise an error if
1413 consecutive build results are not bit-for-bit identical. Note that this
1414 setting can be overridden by clients such as @command{guix build}
1415 (@pxref{Invoking guix build}).
1417 When used in conjunction with @option{--keep-failed}, the differing
1418 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1419 This makes it easy to look for differences between the two results.
1422 Produce debugging output.
1424 This is useful to debug daemon start-up issues, but then it may be
1425 overridden by clients, for example the @code{--verbosity} option of
1426 @command{guix build} (@pxref{Invoking guix build}).
1428 @item --chroot-directory=@var{dir}
1429 Add @var{dir} to the build chroot.
1431 Doing this may change the result of build processes---for instance if
1432 they use optional dependencies found in @var{dir} when it is available,
1433 and not otherwise. For that reason, it is not recommended to do so.
1434 Instead, make sure that each derivation declares all the inputs that it
1437 @item --disable-chroot
1438 Disable chroot builds.
1440 Using this option is not recommended since, again, it would allow build
1441 processes to gain access to undeclared dependencies. It is necessary,
1442 though, when @command{guix-daemon} is running under an unprivileged user
1445 @item --log-compression=@var{type}
1446 Compress build logs according to @var{type}, one of @code{gzip},
1447 @code{bzip2}, or @code{none}.
1449 Unless @code{--lose-logs} is used, all the build logs are kept in the
1450 @var{localstatedir}. To save space, the daemon automatically compresses
1451 them with bzip2 by default.
1453 @item --disable-deduplication
1454 @cindex deduplication
1455 Disable automatic file ``deduplication'' in the store.
1457 By default, files added to the store are automatically ``deduplicated'':
1458 if a newly added file is identical to another one found in the store,
1459 the daemon makes the new file a hard link to the other file. This can
1460 noticeably reduce disk usage, at the expense of slightly increased
1461 input/output load at the end of a build process. This option disables
1464 @item --gc-keep-outputs[=yes|no]
1465 Tell whether the garbage collector (GC) must keep outputs of live
1469 @cindex garbage collector roots
1470 When set to ``yes'', the GC will keep the outputs of any live derivation
1471 available in the store---the @code{.drv} files. The default is ``no'',
1472 meaning that derivation outputs are kept only if they are reachable from a GC
1473 root. @xref{Invoking guix gc}, for more on GC roots.
1475 @item --gc-keep-derivations[=yes|no]
1476 Tell whether the garbage collector (GC) must keep derivations
1477 corresponding to live outputs.
1479 When set to ``yes'', as is the case by default, the GC keeps
1480 derivations---i.e., @code{.drv} files---as long as at least one of their
1481 outputs is live. This allows users to keep track of the origins of
1482 items in their store. Setting it to ``no'' saves a bit of disk space.
1484 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1485 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1486 ``yes'' causes liveness to flow from derivations to outputs. When both are
1487 set to ``yes'', the effect is to keep all the build prerequisites (the
1488 sources, compiler, libraries, and other build-time tools) of live objects in
1489 the store, regardless of whether these prerequisites are reachable from a GC
1490 root. This is convenient for developers since it saves rebuilds or downloads.
1492 @item --impersonate-linux-2.6
1493 On Linux-based systems, impersonate Linux 2.6. This means that the
1494 kernel's @code{uname} system call will report 2.6 as the release number.
1496 This might be helpful to build programs that (usually wrongfully) depend
1497 on the kernel version number.
1500 Do not keep build logs. By default they are kept under
1501 @code{@var{localstatedir}/guix/log}.
1503 @item --system=@var{system}
1504 Assume @var{system} as the current system type. By default it is the
1505 architecture/kernel pair found at configure time, such as
1506 @code{x86_64-linux}.
1508 @item --listen=@var{endpoint}
1509 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1510 as the file name of a Unix-domain socket if it starts with
1511 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1512 host name or host name and port to listen to. Here are a few examples:
1515 @item --listen=/gnu/var/daemon
1516 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1517 creating it if needed.
1519 @item --listen=localhost
1520 @cindex daemon, remote access
1521 @cindex remote access to the daemon
1522 @cindex daemon, cluster setup
1523 @cindex clusters, daemon setup
1524 Listen for TCP connections on the network interface corresponding to
1525 @code{localhost}, on port 44146.
1527 @item --listen=128.0.0.42:1234
1528 Listen for TCP connections on the network interface corresponding to
1529 @code{128.0.0.42}, on port 1234.
1532 This option can be repeated multiple times, in which case
1533 @command{guix-daemon} accepts connections on all the specified
1534 endpoints. Users can tell client commands what endpoint to connect to
1535 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1536 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1539 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1540 @code{--listen=@var{host}} is suitable on local networks, such as
1541 clusters, where only trusted nodes may connect to the build daemon. In
1542 other cases where remote access to the daemon is needed, we recommend
1543 using Unix-domain sockets along with SSH.
1546 When @code{--listen} is omitted, @command{guix-daemon} listens for
1547 connections on the Unix-domain socket located at
1548 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1552 @node Application Setup
1553 @section Application Setup
1555 @cindex foreign distro
1556 When using Guix on top of GNU/Linux distribution other than Guix System---a
1557 so-called @dfn{foreign distro}---a few additional steps are needed to
1558 get everything in place. Here are some of them.
1562 @anchor{locales-and-locpath}
1563 @cindex locales, when not on Guix System
1565 @vindex GUIX_LOCPATH
1566 Packages installed @i{via} Guix will not use the locale data of the
1567 host system. Instead, you must first install one of the locale packages
1568 available with Guix and then define the @code{GUIX_LOCPATH} environment
1572 $ guix package -i glibc-locales
1573 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1576 Note that the @code{glibc-locales} package contains data for all the
1577 locales supported by the GNU@tie{}libc and weighs in at around
1578 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1579 limited to a few UTF-8 locales.
1581 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1582 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1583 Manual}). There are two important differences though:
1587 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1588 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1589 to make sure the programs of the foreign distro will not end up loading
1590 incompatible locale data.
1593 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1594 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1595 should your Guix profile contain a mixture of programs linked against
1596 different libc version, each libc version will only try to load locale
1597 data in the right format.
1600 This is important because the locale data format used by different libc
1601 versions may be incompatible.
1603 @subsection Name Service Switch
1605 @cindex name service switch, glibc
1606 @cindex NSS (name service switch), glibc
1607 @cindex nscd (name service caching daemon)
1608 @cindex name service caching daemon (nscd)
1609 When using Guix on a foreign distro, we @emph{strongly recommend} that
1610 the system run the GNU C library's @dfn{name service cache daemon},
1611 @command{nscd}, which should be listening on the
1612 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1613 installed with Guix may fail to look up host names or user accounts, or
1614 may even crash. The next paragraphs explain why.
1616 @cindex @file{nsswitch.conf}
1617 The GNU C library implements a @dfn{name service switch} (NSS), which is
1618 an extensible mechanism for ``name lookups'' in general: host name
1619 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1620 The GNU C Library Reference Manual}).
1622 @cindex Network information service (NIS)
1623 @cindex NIS (Network information service)
1624 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1625 lookup implementations: for example, the @code{nss-mdns} plugin allow
1626 resolution of @code{.local} host names, the @code{nis} plugin allows
1627 user account lookup using the Network information service (NIS), and so
1628 on. These extra ``lookup services'' are configured system-wide in
1629 @file{/etc/nsswitch.conf}, and all the programs running on the system
1630 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1633 When they perform a name lookup---for instance by calling the
1634 @code{getaddrinfo} function in C---applications first try to connect to
1635 the nscd; on success, nscd performs name lookups on their behalf. If
1636 the nscd is not running, then they perform the name lookup by
1637 themselves, by loading the name lookup services into their own address
1638 space and running it. These name lookup services---the
1639 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1640 the host system's C library, rather than from the C library the
1641 application is linked against (the C library coming from Guix).
1643 And this is where the problem is: if your application is linked against
1644 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1645 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1646 likely crash or have its name lookups fail unexpectedly.
1648 Running @command{nscd} on the system, among other advantages, eliminates
1649 this binary incompatibility problem because those @code{libnss_*.so}
1650 files are loaded in the @command{nscd} process, not in applications
1653 @subsection X11 Fonts
1656 The majority of graphical applications use Fontconfig to locate and
1657 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1658 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1659 by default. Thus, to allow graphical applications installed with Guix
1660 to display fonts, you have to install fonts with Guix as well.
1661 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1662 @code{font-gnu-freefont-ttf}.
1664 To display text written in Chinese languages, Japanese, or Korean in
1665 graphical applications, consider installing
1666 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1667 has multiple outputs, one per language family (@pxref{Packages with
1668 Multiple Outputs}). For instance, the following command installs fonts
1669 for Chinese languages:
1672 guix package -i font-adobe-source-han-sans:cn
1675 @cindex @code{xterm}
1676 Older programs such as @command{xterm} do not use Fontconfig and instead
1677 rely on server-side font rendering. Such programs require to specify a
1678 full name of a font using XLFD (X Logical Font Description), like this:
1681 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1684 To be able to use such full names for the TrueType fonts installed in
1685 your Guix profile, you need to extend the font path of the X server:
1687 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1688 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1690 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1693 @cindex @code{xlsfonts}
1694 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1695 to make sure your TrueType fonts are listed there.
1697 @cindex @code{fc-cache}
1699 After installing fonts you may have to refresh the font cache to use
1700 them in applications. The same applies when applications installed via
1701 Guix do not seem to find fonts. To force rebuilding of the font cache
1702 run @code{fc-cache -f}. The @code{fc-cache} command is provided by the
1703 @code{fontconfig} package.
1705 @subsection X.509 Certificates
1707 @cindex @code{nss-certs}
1708 The @code{nss-certs} package provides X.509 certificates, which allow
1709 programs to authenticate Web servers accessed over HTTPS.
1711 When using Guix on a foreign distro, you can install this package and
1712 define the relevant environment variables so that packages know where to
1713 look for certificates. @xref{X.509 Certificates}, for detailed
1716 @subsection Emacs Packages
1718 @cindex @code{emacs}
1719 When you install Emacs packages with Guix, the elisp files may be placed
1720 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1722 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1723 directory exists because potentially there may exist thousands of Emacs
1724 packages and storing all their files in a single directory may not be
1725 reliable (because of name conflicts). So we think using a separate
1726 directory for each package is a good idea. It is very similar to how
1727 the Emacs package system organizes the file structure (@pxref{Package
1728 Files,,, emacs, The GNU Emacs Manual}).
1730 By default, Emacs (installed with Guix) ``knows'' where these packages
1731 are placed, so you do not need to perform any configuration. If, for
1732 some reason, you want to avoid auto-loading Emacs packages installed
1733 with Guix, you can do so by running Emacs with @code{--no-site-file}
1734 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1736 @subsection The GCC toolchain
1741 Guix offers individual compiler packages such as @code{gcc} but if you
1742 are in need of a complete toolchain for compiling and linking source
1743 code what you really want is the @code{gcc-toolchain} package. This
1744 package provides a complete GCC toolchain for C/C++ development,
1745 including GCC itself, the GNU C Library (headers and binaries, plus
1746 debugging symbols in the @code{debug} output), Binutils, and a linker
1749 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1750 passed to the linker, add corresponding @code{-rpath} arguments, and
1751 invoke the actual linker with this new set of arguments. You can instruct the
1752 wrapper to refuse to link against libraries not in the store by setting the
1753 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
1757 @c *********************************************************************
1758 @node System Installation
1759 @chapter System Installation
1761 @cindex installing Guix System
1762 @cindex Guix System, installation
1763 This section explains how to install Guix System
1764 on a machine. Guix, as a package manager, can
1765 also be installed on top of a running GNU/Linux system,
1766 @pxref{Installation}.
1770 @c This paragraph is for people reading this from tty2 of the
1771 @c installation image.
1772 You are reading this documentation with an Info reader. For details on
1773 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1774 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1775 Info}. Hit @kbd{l} afterwards to come back here.
1777 Alternately, run @command{info info} in another tty to keep the manual
1783 * Limitations:: What you can expect.
1784 * Hardware Considerations:: Supported hardware.
1785 * USB Stick and DVD Installation:: Preparing the installation medium.
1786 * Preparing for Installation:: Networking, partitioning, etc.
1787 * Guided Graphical Installation:: Easy graphical installation.
1788 * Manual Installation:: Manual installation for wizards.
1789 * After System Installation:: When installation succeeded.
1790 * Installing Guix in a VM:: Guix System playground.
1791 * Building the Installation Image:: How this comes to be.
1795 @section Limitations
1797 As of version @value{VERSION}, Guix System is
1798 not production-ready. It may contain bugs and lack important
1799 features. Thus, if you are looking for a stable production system that
1800 respects your freedom as a computer user, a good solution at this point
1801 is to consider @url{http://www.gnu.org/distros/free-distros.html, one of
1802 the more established GNU/Linux distributions}. We hope you can soon switch
1803 to the Guix System without fear, of course. In the meantime, you can
1804 also keep using your distribution and try out the package manager on top
1805 of it (@pxref{Installation}).
1807 Before you proceed with the installation, be aware of the following
1808 noteworthy limitations applicable to version @value{VERSION}:
1812 The installation process does not include a graphical user interface and
1813 requires familiarity with GNU/Linux (see the following subsections to
1814 get a feel of what that means.)
1817 Support for the Logical Volume Manager (LVM) is missing.
1820 More and more system services are provided (@pxref{Services}), but some
1824 More than 8,500 packages are available, but you might
1825 occasionally find that a useful package is missing.
1828 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1829 as well as a number of X11 window managers. However, some graphical
1830 applications may be missing, as well as KDE.
1833 You have been warned! But more than a disclaimer, this is an invitation
1834 to report issues (and success stories!), and to join us in improving it.
1835 @xref{Contributing}, for more info.
1838 @node Hardware Considerations
1839 @section Hardware Considerations
1841 @cindex hardware support on Guix System
1842 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1843 builds around the kernel Linux-libre, which means that only hardware for
1844 which free software drivers and firmware exist is supported. Nowadays,
1845 a wide range of off-the-shelf hardware is supported on
1846 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1847 Ethernet controllers. Unfortunately, there are still areas where
1848 hardware vendors deny users control over their own computing, and such
1849 hardware is not supported on Guix System.
1851 @cindex WiFi, hardware support
1852 One of the main areas where free drivers or firmware are lacking is WiFi
1853 devices. WiFi devices known to work include those using Atheros chips
1854 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1855 driver, and those using Broadcom/AirForce chips (BCM43xx with
1856 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1857 Linux-libre driver. Free firmware exists for both and is available
1858 out-of-the-box on Guix System, as part of @var{%base-firmware}
1859 (@pxref{operating-system Reference, @code{firmware}}).
1861 @cindex RYF, Respects Your Freedom
1862 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1863 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1864 certification program for hardware products that respect your freedom
1865 and your privacy and ensure that you have control over your device. We
1866 encourage you to check the list of RYF-certified devices.
1868 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1869 web site. It contains a catalog of hardware devices with information
1870 about their support in GNU/Linux.
1873 @node USB Stick and DVD Installation
1874 @section USB Stick and DVD Installation
1876 An ISO-9660 installation image that can be written to a USB stick or
1877 burnt to a DVD can be downloaded from
1878 @indicateurl{https://alpha.gnu.org/gnu/guix/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1879 where @var{system} is one of:
1883 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1886 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1889 @c start duplication of authentication part from ``Binary Installation''
1890 Make sure to download the associated @file{.sig} file and to verify the
1891 authenticity of the image against it, along these lines:
1894 $ wget https://alpha.gnu.org/gnu/guix/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1895 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1898 If that command fails because you do not have the required public key,
1899 then run this command to import it:
1902 $ gpg --keyserver @value{KEY-SERVER} \
1903 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
1907 and rerun the @code{gpg --verify} command.
1910 This image contains the tools necessary for an installation.
1911 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1913 @unnumberedsubsec Copying to a USB Stick
1915 To copy the image to a USB stick, follow these steps:
1919 Decompress the image using the @command{xz} command:
1922 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1926 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1927 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1928 copy the image with:
1931 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1935 Access to @file{/dev/sdX} usually requires root privileges.
1938 @unnumberedsubsec Burning on a DVD
1940 To copy the image to a DVD, follow these steps:
1944 Decompress the image using the @command{xz} command:
1947 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1951 Insert a blank DVD into your machine, and determine
1952 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
1953 copy the image with:
1956 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
1959 Access to @file{/dev/srX} usually requires root privileges.
1962 @unnumberedsubsec Booting
1964 Once this is done, you should be able to reboot the system and boot from
1965 the USB stick or DVD. The latter usually requires you to get in the
1966 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
1968 @xref{Installing Guix in a VM}, if, instead, you would like to install
1969 Guix System in a virtual machine (VM).
1972 @node Preparing for Installation
1973 @section Preparing for Installation
1975 Once you have booted, you can use the guided graphical installer, which makes
1976 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
1977 if you are already familiar with GNU/Linux and if you want more control than
1978 what the graphical installer provides, you can choose the ``manual''
1979 installation process (@pxref{Manual Installation}).
1981 The graphical installer is available on TTY1. You can obtain root shells on
1982 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
1983 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
1984 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
1985 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
1986 which allows you to select text with the left mouse button and to paste it
1987 with the middle button.
1990 Installation requires access to the Internet so that any missing
1991 dependencies of your system configuration can be downloaded. See the
1992 ``Networking'' section below.
1995 @node Guided Graphical Installation
1996 @section Guided Graphical Installation
1998 The graphical installer is a text-based user interface. It will guide you,
1999 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2001 The first dialog boxes allow you to set up the system as you use it during the
2002 installation: you can choose the language, keyboard layout, and set up
2003 networking, which will be used during the installation. The image below shows
2004 the networking dialog.
2006 @image{images/installer-network,5in,, networking setup with the graphical installer}
2008 Later steps allow you to partition your hard disk, as shown in the image
2009 below, to choose whether or not to use encrypted file systems, to enter the
2010 host name and root password, and to create an additional account, among other
2013 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2015 Note that, at any time, the installer allows you to exit the current
2016 installation step and resume at a previous step, as show in the image below.
2018 @image{images/installer-resume,5in,, resuming the installation process}
2020 Once you're done, the installer produces an operating system configuration and
2021 displays it (@pxref{Using the Configuration System}). At that point you can
2022 hit ``OK'' and installation will proceed. On success, you can reboot into the
2023 new system and enjoy. @xref{After System Installation}, for what's next!
2026 @node Manual Installation
2027 @section Manual Installation
2029 This section describes how you would ``manually'' install GNU@tie{}Guix System
2030 on your machine. This option requires familiarity with GNU/Linux, with the
2031 shell, and with common administration tools. If you think this is not for
2032 you, consider using the guided graphical installer (@pxref{Guided Graphical
2035 The installation system provides root shells on TTYs 3 to 6; press
2036 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2037 many common tools needed to install the system. But it is also a full-blown
2038 Guix System, which means that you can install additional packages, should you
2039 need it, using @command{guix package} (@pxref{Invoking guix package}).
2042 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2043 * Proceeding with the Installation:: Installing.
2046 @node Keyboard Layout and Networking and Partitioning
2047 @subsection Keyboard Layout, Networking, and Partitioning
2049 Before you can install the system, you may want to adjust the keyboard layout,
2050 set up networking, and partition your target hard disk. This section will
2051 guide you through this.
2053 @subsubsection Keyboard Layout
2055 @cindex keyboard layout
2056 The installation image uses the US qwerty keyboard layout. If you want
2057 to change it, you can use the @command{loadkeys} command. For example,
2058 the following command selects the Dvorak keyboard layout:
2064 See the files under @file{/run/current-system/profile/share/keymaps} for
2065 a list of available keyboard layouts. Run @command{man loadkeys} for
2068 @subsubsection Networking
2070 Run the following command to see what your network interfaces are called:
2077 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2083 @c http://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2084 Wired interfaces have a name starting with @samp{e}; for example, the
2085 interface corresponding to the first on-board Ethernet controller is
2086 called @samp{eno1}. Wireless interfaces have a name starting with
2087 @samp{w}, like @samp{w1p2s0}.
2090 @item Wired connection
2091 To configure a wired network run the following command, substituting
2092 @var{interface} with the name of the wired interface you want to use.
2095 ifconfig @var{interface} up
2098 @item Wireless connection
2101 To configure wireless networking, you can create a configuration file
2102 for the @command{wpa_supplicant} configuration tool (its location is not
2103 important) using one of the available text editors such as
2107 nano wpa_supplicant.conf
2110 As an example, the following stanza can go to this file and will work
2111 for many wireless networks, provided you give the actual SSID and
2112 passphrase for the network you are connecting to:
2116 ssid="@var{my-ssid}"
2118 psk="the network's secret passphrase"
2122 Start the wireless service and run it in the background with the
2123 following command (substitute @var{interface} with the name of the
2124 network interface you want to use):
2127 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2130 Run @command{man wpa_supplicant} for more information.
2134 At this point, you need to acquire an IP address. On a network where IP
2135 addresses are automatically assigned @i{via} DHCP, you can run:
2138 dhclient -v @var{interface}
2141 Try to ping a server to see if networking is up and running:
2147 Setting up network access is almost always a requirement because the
2148 image does not contain all the software and tools that may be needed.
2150 @cindex installing over SSH
2151 If you want to, you can continue the installation remotely by starting
2155 herd start ssh-daemon
2158 Make sure to either set a password with @command{passwd}, or configure
2159 OpenSSH public key authentication before logging in.
2161 @subsubsection Disk Partitioning
2163 Unless this has already been done, the next step is to partition, and
2164 then format the target partition(s).
2166 The installation image includes several partitioning tools, including
2167 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2168 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2169 the partition layout you want:
2175 If your disk uses the GUID Partition Table (GPT) format and you plan to
2176 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2177 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2180 @cindex EFI, installation
2181 @cindex UEFI, installation
2182 @cindex ESP, EFI system partition
2183 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2184 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2185 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2188 parted /dev/sda set 1 esp on
2192 @vindex grub-bootloader
2193 @vindex grub-efi-bootloader
2194 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2195 @file{/sys/firmware/efi} exists in the installation image, then you should
2196 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2197 Otherwise you should use the BIOS-based GRUB, known as
2198 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2202 Once you are done partitioning the target hard disk drive, you have to
2203 create a file system on the relevant partition(s)@footnote{Currently
2204 Guix System only supports ext4 and btrfs file systems. In particular, code
2205 that reads file system UUIDs and labels only works for these file system
2206 types.}. For the ESP, if you have one and assuming it is
2207 @file{/dev/sda1}, run:
2210 mkfs.fat -F32 /dev/sda1
2213 Preferably, assign file systems a label so that you can easily and
2214 reliably refer to them in @code{file-system} declarations (@pxref{File
2215 Systems}). This is typically done using the @code{-L} option of
2216 @command{mkfs.ext4} and related commands. So, assuming the target root
2217 partition lives at @file{/dev/sda2}, a file system with the label
2218 @code{my-root} can be created with:
2221 mkfs.ext4 -L my-root /dev/sda2
2224 @cindex encrypted disk
2225 If you are instead planning to encrypt the root partition, you can use
2226 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2227 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2228 @code{man cryptsetup}} for more information.) Assuming you want to
2229 store the root partition on @file{/dev/sda2}, the command sequence would
2230 be along these lines:
2233 cryptsetup luksFormat /dev/sda2
2234 cryptsetup open --type luks /dev/sda2 my-partition
2235 mkfs.ext4 -L my-root /dev/mapper/my-partition
2238 Once that is done, mount the target file system under @file{/mnt}
2239 with a command like (again, assuming @code{my-root} is the label of the
2243 mount LABEL=my-root /mnt
2246 Also mount any other file systems you would like to use on the target
2247 system relative to this path. If you have opted for @file{/boot/efi} as an
2248 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2249 found by @code{guix system init} afterwards.
2251 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2252 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2253 sure to initialize them with @command{mkswap}. Assuming you have one
2254 swap partition on @file{/dev/sda3}, you would run:
2261 Alternatively, you may use a swap file. For example, assuming that in
2262 the new system you want to use the file @file{/swapfile} as a swap file,
2263 you would run@footnote{This example will work for many types of file
2264 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2265 btrfs), the required steps may be different. For details, see the
2266 manual pages for @command{mkswap} and @command{swapon}.}:
2269 # This is 10 GiB of swap space. Adjust "count" to change the size.
2270 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2271 # For security, make the file readable and writable only by root.
2272 chmod 600 /mnt/swapfile
2273 mkswap /mnt/swapfile
2274 swapon /mnt/swapfile
2277 Note that if you have encrypted the root partition and created a swap
2278 file in its file system as described above, then the encryption also
2279 protects the swap file, just like any other file in that file system.
2281 @node Proceeding with the Installation
2282 @subsection Proceeding with the Installation
2284 With the target partitions ready and the target root mounted on
2285 @file{/mnt}, we're ready to go. First, run:
2288 herd start cow-store /mnt
2291 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2292 during the installation phase are written to the target disk on @file{/mnt}
2293 rather than kept in memory. This is necessary because the first phase of
2294 the @command{guix system init} command (see below) entails downloads or
2295 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2297 Next, you have to edit a file and
2298 provide the declaration of the operating system to be installed. To
2299 that end, the installation system comes with three text editors. We
2300 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2301 supports syntax highlighting and parentheses matching; other editors
2302 include GNU Zile (an Emacs clone), and
2303 nvi (a clone of the original BSD @command{vi} editor).
2304 We strongly recommend storing that file on the target root file system, say,
2305 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2306 configuration file once you have rebooted into the newly-installed system.
2308 @xref{Using the Configuration System}, for an overview of the
2309 configuration file. The example configurations discussed in that
2310 section are available under @file{/etc/configuration} in the
2311 installation image. Thus, to get started with a system configuration
2312 providing a graphical display server (a ``desktop'' system), you can run
2313 something along these lines:
2317 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2318 # nano /mnt/etc/config.scm
2321 You should pay attention to what your configuration file contains, and
2326 Make sure the @code{bootloader-configuration} form refers to the target
2327 you want to install GRUB on. It should mention @code{grub-bootloader} if
2328 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2329 for newer UEFI systems. For legacy systems, the @code{target} field
2330 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2331 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2332 currently mounted and a @code{file-system} entry is specified in your
2336 Be sure that your file system labels match the value of their respective
2337 @code{device} fields in your @code{file-system} configuration, assuming
2338 your @code{file-system} configuration uses the @code{file-system-label}
2339 procedure in its @code{device} field.
2342 If there are encrypted or RAID partitions, make sure to add a
2343 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2346 Once you are done preparing the configuration file, the new system must
2347 be initialized (remember that the target root file system is mounted
2351 guix system init /mnt/etc/config.scm /mnt
2355 This copies all the necessary files and installs GRUB on
2356 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2357 more information, @pxref{Invoking guix system}. This command may trigger
2358 downloads or builds of missing packages, which can take some time.
2360 Once that command has completed---and hopefully succeeded!---you can run
2361 @command{reboot} and boot into the new system. The @code{root} password
2362 in the new system is initially empty; other users' passwords need to be
2363 initialized by running the @command{passwd} command as @code{root},
2364 unless your configuration specifies otherwise
2365 (@pxref{user-account-password, user account passwords}).
2366 @xref{After System Installation}, for what's next!
2369 @node After System Installation
2370 @section After System Installation
2372 Success, you've now booted into Guix System! From then on, you can update the
2373 system whenever you want by running, say:
2377 sudo guix system reconfigure /etc/config.scm
2381 This builds a new system generation with the latest packages and services
2382 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2383 your system includes the latest security updates (@pxref{Security Updates}).
2385 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2387 @cindex sudo vs. @command{guix pull}
2388 Note that @command{sudo guix} runs your user's @command{guix} command and
2389 @emph{not} root's, because @command{sudo} leaves @code{PATH} unchanged. To
2390 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2393 Join us on @code{#guix} on the Freenode IRC network or on
2394 @email{guix-devel@@gnu.org} to share your experience!
2397 @node Installing Guix in a VM
2398 @section Installing Guix in a Virtual Machine
2400 @cindex virtual machine, Guix System installation
2401 @cindex virtual private server (VPS)
2402 @cindex VPS (virtual private server)
2403 If you'd like to install Guix System in a virtual machine (VM) or on a
2404 virtual private server (VPS) rather than on your beloved machine, this
2407 To boot a @uref{http://qemu.org/,QEMU} VM for installing Guix System in a
2408 disk image, follow these steps:
2412 First, retrieve and decompress the Guix system installation image as
2413 described previously (@pxref{USB Stick and DVD Installation}).
2416 Create a disk image that will hold the installed system. To make a
2417 qcow2-formatted disk image, use the @command{qemu-img} command:
2420 qemu-img create -f qcow2 guixsd.img 50G
2423 The resulting file will be much smaller than 50 GB (typically less than
2424 1 MB), but it will grow as the virtualized storage device is filled up.
2427 Boot the USB installation image in an VM:
2430 qemu-system-x86_64 -m 1024 -smp 1 \
2431 -net user -net nic,model=virtio -boot menu=on \
2432 -drive file=guix-system-install-@value{VERSION}.@var{system}.iso \
2433 -drive file=guixsd.img
2436 The ordering of the drives matters.
2438 In the VM console, quickly press the @kbd{F12} key to enter the boot
2439 menu. Then press the @kbd{2} key and the @kbd{RET} key to validate your
2443 You're now root in the VM, proceed with the installation process.
2444 @xref{Preparing for Installation}, and follow the instructions.
2447 Once installation is complete, you can boot the system that's on your
2448 @file{guixsd.img} image. @xref{Running Guix in a VM}, for how to do
2451 @node Building the Installation Image
2452 @section Building the Installation Image
2454 @cindex installation image
2455 The installation image described above was built using the @command{guix
2456 system} command, specifically:
2459 guix system disk-image --file-system-type=iso9660 \
2460 gnu/system/install.scm
2463 Have a look at @file{gnu/system/install.scm} in the source tree,
2464 and see also @ref{Invoking guix system} for more information
2465 about the installation image.
2467 @section Building the Installation Image for ARM Boards
2469 Many ARM boards require a specific variant of the
2470 @uref{http://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2472 If you build a disk image and the bootloader is not available otherwise
2473 (on another boot drive etc), it's advisable to build an image that
2474 includes the bootloader, specifically:
2477 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2480 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2481 board, a list of possible boards will be printed.
2483 @c *********************************************************************
2484 @node Package Management
2485 @chapter Package Management
2488 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2489 remove software packages, without having to know about their build
2490 procedures or dependencies. Guix also goes beyond this obvious set of
2493 This chapter describes the main features of Guix, as well as the
2494 package management tools it provides. Along with the command-line
2495 interface described below (@pxref{Invoking guix package, @code{guix
2496 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2497 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2498 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2502 guix package -i emacs-guix
2506 * Features:: How Guix will make your life brighter.
2507 * Invoking guix package:: Package installation, removal, etc.
2508 * Substitutes:: Downloading pre-built binaries.
2509 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2510 * Invoking guix gc:: Running the garbage collector.
2511 * Invoking guix pull:: Fetching the latest Guix and distribution.
2512 * Channels:: Customizing the package collection.
2513 * Inferiors:: Interacting with another revision of Guix.
2514 * Invoking guix describe:: Display information about your Guix revision.
2515 * Invoking guix archive:: Exporting and importing store files.
2521 When using Guix, each package ends up in the @dfn{package store}, in its
2522 own directory---something that resembles
2523 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2525 Instead of referring to these directories, users have their own
2526 @dfn{profile}, which points to the packages that they actually want to
2527 use. These profiles are stored within each user's home directory, at
2528 @code{$HOME/.guix-profile}.
2530 For example, @code{alice} installs GCC 4.7.2. As a result,
2531 @file{/home/alice/.guix-profile/bin/gcc} points to
2532 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2533 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2534 simply continues to point to
2535 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2536 coexist on the same system without any interference.
2538 The @command{guix package} command is the central tool to manage
2539 packages (@pxref{Invoking guix package}). It operates on the per-user
2540 profiles, and can be used @emph{with normal user privileges}.
2542 @cindex transactions
2543 The command provides the obvious install, remove, and upgrade
2544 operations. Each invocation is actually a @emph{transaction}: either
2545 the specified operation succeeds, or nothing happens. Thus, if the
2546 @command{guix package} process is terminated during the transaction,
2547 or if a power outage occurs during the transaction, then the user's
2548 profile remains in its previous state, and remains usable.
2550 In addition, any package transaction may be @emph{rolled back}. So, if,
2551 for example, an upgrade installs a new version of a package that turns
2552 out to have a serious bug, users may roll back to the previous instance
2553 of their profile, which was known to work well. Similarly, the global
2554 system configuration on Guix is subject to
2555 transactional upgrades and roll-back
2556 (@pxref{Using the Configuration System}).
2558 All packages in the package store may be @emph{garbage-collected}.
2559 Guix can determine which packages are still referenced by user
2560 profiles, and remove those that are provably no longer referenced
2561 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2562 generations of their profile so that the packages they refer to can be
2565 @cindex reproducibility
2566 @cindex reproducible builds
2567 Guix takes a @dfn{purely functional} approach to package
2568 management, as described in the introduction (@pxref{Introduction}).
2569 Each @file{/gnu/store} package directory name contains a hash of all the
2570 inputs that were used to build that package---compiler, libraries, build
2571 scripts, etc. This direct correspondence allows users to make sure a
2572 given package installation matches the current state of their
2573 distribution. It also helps maximize @dfn{build reproducibility}:
2574 thanks to the isolated build environments that are used, a given build
2575 is likely to yield bit-identical files when performed on different
2576 machines (@pxref{Invoking guix-daemon, container}).
2579 This foundation allows Guix to support @dfn{transparent binary/source
2580 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2581 available from an external source---a @dfn{substitute}, Guix just
2582 downloads it and unpacks it;
2583 otherwise, it builds the package from source, locally
2584 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2585 reproducible, users do not have to trust servers that provide
2586 substitutes: they can force a local build and @emph{challenge} providers
2587 (@pxref{Invoking guix challenge}).
2589 Control over the build environment is a feature that is also useful for
2590 developers. The @command{guix environment} command allows developers of
2591 a package to quickly set up the right development environment for their
2592 package, without having to manually install the dependencies of the
2593 package into their profile (@pxref{Invoking guix environment}).
2595 @cindex replication, of software environments
2596 @cindex provenance tracking, of software artifacts
2597 All of Guix and its package definitions is version-controlled, and
2598 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2599 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2600 Guix instance on a different machine or at a later point in time, which in
2601 turn allows you to @emph{replicate complete software environments}, while
2602 retaining precise @dfn{provenance tracking} of the software.
2604 @node Invoking guix package
2605 @section Invoking @command{guix package}
2607 @cindex installing packages
2608 @cindex removing packages
2609 @cindex package installation
2610 @cindex package removal
2611 The @command{guix package} command is the tool that allows users to
2612 install, upgrade, and remove packages, as well as rolling back to
2613 previous configurations. It operates only on the user's own profile,
2614 and works with normal user privileges (@pxref{Features}). Its syntax
2618 guix package @var{options}
2620 @cindex transactions
2621 Primarily, @var{options} specifies the operations to be performed during
2622 the transaction. Upon completion, a new profile is created, but
2623 previous @dfn{generations} of the profile remain available, should the user
2626 For example, to remove @code{lua} and install @code{guile} and
2627 @code{guile-cairo} in a single transaction:
2630 guix package -r lua -i guile guile-cairo
2633 @command{guix package} also supports a @dfn{declarative approach}
2634 whereby the user specifies the exact set of packages to be available and
2635 passes it @i{via} the @option{--manifest} option
2636 (@pxref{profile-manifest, @option{--manifest}}).
2639 For each user, a symlink to the user's default profile is automatically
2640 created in @file{$HOME/.guix-profile}. This symlink always points to the
2641 current generation of the user's default profile. Thus, users can add
2642 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
2643 variable, and so on.
2644 @cindex search paths
2645 If you are not using the Guix System Distribution, consider adding the
2646 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2647 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2648 shells get all the right environment variable definitions:
2651 GUIX_PROFILE="$HOME/.guix-profile" ; \
2652 source "$HOME/.guix-profile/etc/profile"
2655 In a multi-user setup, user profiles are stored in a place registered as
2656 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2657 to (@pxref{Invoking guix gc}). That directory is normally
2658 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2659 @var{localstatedir} is the value passed to @code{configure} as
2660 @code{--localstatedir}, and @var{user} is the user name. The
2661 @file{per-user} directory is created when @command{guix-daemon} is
2662 started, and the @var{user} sub-directory is created by @command{guix
2665 The @var{options} can be among the following:
2669 @item --install=@var{package} @dots{}
2670 @itemx -i @var{package} @dots{}
2671 Install the specified @var{package}s.
2673 Each @var{package} may specify either a simple package name, such as
2674 @code{guile}, or a package name followed by an at-sign and version number,
2675 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2676 case, the newest version prefixed by @code{1.8} is selected.)
2678 If no version number is specified, the
2679 newest available version will be selected. In addition, @var{package}
2680 may contain a colon, followed by the name of one of the outputs of the
2681 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2682 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2683 name (and optionally version) are searched for among the GNU
2684 distribution modules (@pxref{Package Modules}).
2686 @cindex propagated inputs
2687 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2688 that automatically get installed along with the required package
2689 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2690 @code{package} objects}, for information about propagated inputs in
2691 package definitions).
2693 @anchor{package-cmd-propagated-inputs}
2694 An example is the GNU MPC library: its C header files refer to those of
2695 the GNU MPFR library, which in turn refer to those of the GMP library.
2696 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2697 in the profile; removing MPC also removes MPFR and GMP---unless they had
2698 also been explicitly installed by the user.
2700 Besides, packages sometimes rely on the definition of environment
2701 variables for their search paths (see explanation of
2702 @code{--search-paths} below). Any missing or possibly incorrect
2703 environment variable definitions are reported here.
2705 @item --install-from-expression=@var{exp}
2707 Install the package @var{exp} evaluates to.
2709 @var{exp} must be a Scheme expression that evaluates to a
2710 @code{<package>} object. This option is notably useful to disambiguate
2711 between same-named variants of a package, with expressions such as
2712 @code{(@@ (gnu packages base) guile-final)}.
2714 Note that this option installs the first output of the specified
2715 package, which may be insufficient when needing a specific output of a
2716 multiple-output package.
2718 @item --install-from-file=@var{file}
2719 @itemx -f @var{file}
2720 Install the package that the code within @var{file} evaluates to.
2722 As an example, @var{file} might contain a definition like this
2723 (@pxref{Defining Packages}):
2726 @verbatiminclude package-hello.scm
2729 Developers may find it useful to include such a @file{guix.scm} file
2730 in the root of their project source tree that can be used to test
2731 development snapshots and create reproducible development environments
2732 (@pxref{Invoking guix environment}).
2734 @item --remove=@var{package} @dots{}
2735 @itemx -r @var{package} @dots{}
2736 Remove the specified @var{package}s.
2738 As for @code{--install}, each @var{package} may specify a version number
2739 and/or output name in addition to the package name. For instance,
2740 @code{-r glibc:debug} would remove the @code{debug} output of
2743 @item --upgrade[=@var{regexp} @dots{}]
2744 @itemx -u [@var{regexp} @dots{}]
2745 @cindex upgrading packages
2746 Upgrade all the installed packages. If one or more @var{regexp}s are
2747 specified, upgrade only installed packages whose name matches a
2748 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2750 Note that this upgrades package to the latest version of packages found
2751 in the distribution currently installed. To update your distribution,
2752 you should regularly run @command{guix pull} (@pxref{Invoking guix
2755 @item --do-not-upgrade[=@var{regexp} @dots{}]
2756 When used together with the @code{--upgrade} option, do @emph{not}
2757 upgrade any packages whose name matches a @var{regexp}. For example, to
2758 upgrade all packages in the current profile except those containing the
2759 substring ``emacs'':
2762 $ guix package --upgrade . --do-not-upgrade emacs
2765 @item @anchor{profile-manifest}--manifest=@var{file}
2766 @itemx -m @var{file}
2767 @cindex profile declaration
2768 @cindex profile manifest
2769 Create a new generation of the profile from the manifest object
2770 returned by the Scheme code in @var{file}.
2772 This allows you to @emph{declare} the profile's contents rather than
2773 constructing it through a sequence of @code{--install} and similar
2774 commands. The advantage is that @var{file} can be put under version
2775 control, copied to different machines to reproduce the same profile, and
2778 @c FIXME: Add reference to (guix profile) documentation when available.
2779 @var{file} must return a @dfn{manifest} object, which is roughly a list
2782 @findex packages->manifest
2784 (use-package-modules guile emacs)
2789 ;; Use a specific package output.
2790 (list guile-2.0 "debug")))
2793 @findex specifications->manifest
2794 In this example we have to know which modules define the @code{emacs}
2795 and @code{guile-2.0} variables to provide the right
2796 @code{use-package-modules} line, which can be cumbersome. We can
2797 instead provide regular package specifications and let
2798 @code{specifications->manifest} look up the corresponding package
2802 (specifications->manifest
2803 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2807 @cindex rolling back
2808 @cindex undoing transactions
2809 @cindex transactions, undoing
2810 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2811 the last transaction.
2813 When combined with options such as @code{--install}, roll back occurs
2814 before any other actions.
2816 When rolling back from the first generation that actually contains
2817 installed packages, the profile is made to point to the @dfn{zeroth
2818 generation}, which contains no files apart from its own metadata.
2820 After having rolled back, installing, removing, or upgrading packages
2821 overwrites previous future generations. Thus, the history of the
2822 generations in a profile is always linear.
2824 @item --switch-generation=@var{pattern}
2825 @itemx -S @var{pattern}
2827 Switch to a particular generation defined by @var{pattern}.
2829 @var{pattern} may be either a generation number or a number prefixed
2830 with ``+'' or ``-''. The latter means: move forward/backward by a
2831 specified number of generations. For example, if you want to return to
2832 the latest generation after @code{--roll-back}, use
2833 @code{--switch-generation=+1}.
2835 The difference between @code{--roll-back} and
2836 @code{--switch-generation=-1} is that @code{--switch-generation} will
2837 not make a zeroth generation, so if a specified generation does not
2838 exist, the current generation will not be changed.
2840 @item --search-paths[=@var{kind}]
2841 @cindex search paths
2842 Report environment variable definitions, in Bash syntax, that may be
2843 needed in order to use the set of installed packages. These environment
2844 variables are used to specify @dfn{search paths} for files used by some
2845 of the installed packages.
2847 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2848 environment variables to be defined so it can look for headers and
2849 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2850 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2851 library are installed in the profile, then @code{--search-paths} will
2852 suggest setting these variables to @code{@var{profile}/include} and
2853 @code{@var{profile}/lib}, respectively.
2855 The typical use case is to define these environment variables in the
2859 $ eval `guix package --search-paths`
2862 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2863 meaning that the returned environment variable definitions will either
2864 be exact settings, or prefixes or suffixes of the current value of these
2865 variables. When omitted, @var{kind} defaults to @code{exact}.
2867 This option can also be used to compute the @emph{combined} search paths
2868 of several profiles. Consider this example:
2871 $ guix package -p foo -i guile
2872 $ guix package -p bar -i guile-json
2873 $ guix package -p foo -p bar --search-paths
2876 The last command above reports about the @code{GUILE_LOAD_PATH}
2877 variable, even though, taken individually, neither @file{foo} nor
2878 @file{bar} would lead to that recommendation.
2881 @item --profile=@var{profile}
2882 @itemx -p @var{profile}
2883 Use @var{profile} instead of the user's default profile.
2885 @cindex collisions, in a profile
2886 @cindex colliding packages in profiles
2887 @cindex profile collisions
2888 @item --allow-collisions
2889 Allow colliding packages in the new profile. Use at your own risk!
2891 By default, @command{guix package} reports as an error @dfn{collisions}
2892 in the profile. Collisions happen when two or more different versions
2893 or variants of a given package end up in the profile.
2896 Use the bootstrap Guile to build the profile. This option is only
2897 useful to distribution developers.
2901 In addition to these actions, @command{guix package} supports the
2902 following options to query the current state of a profile, or the
2903 availability of packages:
2907 @item --search=@var{regexp}
2908 @itemx -s @var{regexp}
2909 @cindex searching for packages
2910 List the available packages whose name, synopsis, or description matches
2911 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
2912 Print all the metadata of matching packages in
2913 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
2914 GNU recutils manual}).
2916 This allows specific fields to be extracted using the @command{recsel}
2917 command, for instance:
2920 $ guix package -s malloc | recsel -p name,version,relevance
2934 Similarly, to show the name of all the packages available under the
2935 terms of the GNU@tie{}LGPL version 3:
2938 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
2945 It is also possible to refine search results using several @code{-s}
2946 flags. For example, the following command returns a list of board
2950 $ guix package -s '\<board\>' -s game | recsel -p name
2955 If we were to omit @code{-s game}, we would also get software packages
2956 that deal with printed circuit boards; removing the angle brackets
2957 around @code{board} would further add packages that have to do with
2960 And now for a more elaborate example. The following command searches
2961 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
2962 libraries, and prints the name and synopsis of the matching packages:
2965 $ guix package -s crypto -s library | \
2966 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
2970 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
2971 information on @dfn{selection expressions} for @code{recsel -e}.
2973 @item --show=@var{package}
2974 Show details about @var{package}, taken from the list of available packages, in
2975 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
2979 $ guix package --show=python | recsel -p name,version
2987 You may also specify the full name of a package to only get details about a
2988 specific version of it:
2990 $ guix package --show=python@@3.4 | recsel -p name,version
2997 @item --list-installed[=@var{regexp}]
2998 @itemx -I [@var{regexp}]
2999 List the currently installed packages in the specified profile, with the
3000 most recently installed packages shown last. When @var{regexp} is
3001 specified, list only installed packages whose name matches @var{regexp}.
3003 For each installed package, print the following items, separated by
3004 tabs: the package name, its version string, the part of the package that
3005 is installed (for instance, @code{out} for the default output,
3006 @code{include} for its headers, etc.), and the path of this package in
3009 @item --list-available[=@var{regexp}]
3010 @itemx -A [@var{regexp}]
3011 List packages currently available in the distribution for this system
3012 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3013 installed packages whose name matches @var{regexp}.
3015 For each package, print the following items separated by tabs: its name,
3016 its version string, the parts of the package (@pxref{Packages with
3017 Multiple Outputs}), and the source location of its definition.
3019 @item --list-generations[=@var{pattern}]
3020 @itemx -l [@var{pattern}]
3022 Return a list of generations along with their creation dates; for each
3023 generation, show the installed packages, with the most recently
3024 installed packages shown last. Note that the zeroth generation is never
3027 For each installed package, print the following items, separated by
3028 tabs: the name of a package, its version string, the part of the package
3029 that is installed (@pxref{Packages with Multiple Outputs}), and the
3030 location of this package in the store.
3032 When @var{pattern} is used, the command returns only matching
3033 generations. Valid patterns include:
3036 @item @emph{Integers and comma-separated integers}. Both patterns denote
3037 generation numbers. For instance, @code{--list-generations=1} returns
3040 And @code{--list-generations=1,8,2} outputs three generations in the
3041 specified order. Neither spaces nor trailing commas are allowed.
3043 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
3044 specified generations and everything in between. Note that the start of
3045 a range must be smaller than its end.
3047 It is also possible to omit the endpoint. For example,
3048 @code{--list-generations=2..}, returns all generations starting from the
3051 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3052 or months by passing an integer along with the first letter of the
3053 duration. For example, @code{--list-generations=20d} lists generations
3054 that are up to 20 days old.
3057 @item --delete-generations[=@var{pattern}]
3058 @itemx -d [@var{pattern}]
3059 When @var{pattern} is omitted, delete all generations except the current
3062 This command accepts the same patterns as @option{--list-generations}.
3063 When @var{pattern} is specified, delete the matching generations. When
3064 @var{pattern} specifies a duration, generations @emph{older} than the
3065 specified duration match. For instance, @code{--delete-generations=1m}
3066 deletes generations that are more than one month old.
3068 If the current generation matches, it is @emph{not} deleted. Also, the
3069 zeroth generation is never deleted.
3071 Note that deleting generations prevents rolling back to them.
3072 Consequently, this command must be used with care.
3076 Finally, since @command{guix package} may actually start build
3077 processes, it supports all the common build options (@pxref{Common Build
3078 Options}). It also supports package transformation options, such as
3079 @option{--with-source} (@pxref{Package Transformation Options}).
3080 However, note that package transformations are lost when upgrading; to
3081 preserve transformations across upgrades, you should define your own
3082 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
3083 (@pxref{Defining Packages}).
3086 @section Substitutes
3089 @cindex pre-built binaries
3090 Guix supports transparent source/binary deployment, which means that it
3091 can either build things locally, or download pre-built items from a
3092 server, or both. We call these pre-built items @dfn{substitutes}---they
3093 are substitutes for local build results. In many cases, downloading a
3094 substitute is much faster than building things locally.
3096 Substitutes can be anything resulting from a derivation build
3097 (@pxref{Derivations}). Of course, in the common case, they are
3098 pre-built package binaries, but source tarballs, for instance, which
3099 also result from derivation builds, can be available as substitutes.
3102 * Official Substitute Server:: One particular source of substitutes.
3103 * Substitute Server Authorization:: How to enable or disable substitutes.
3104 * Substitute Authentication:: How Guix verifies substitutes.
3105 * Proxy Settings:: How to get substitutes via proxy.
3106 * Substitution Failure:: What happens when substitution fails.
3107 * On Trusting Binaries:: How can you trust that binary blob?
3110 @node Official Substitute Server
3111 @subsection Official Substitute Server
3115 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3116 that builds packages from Guix continuously for some
3117 architectures, and makes them available as substitutes. This is the
3118 default source of substitutes; it can be overridden by passing the
3119 @option{--substitute-urls} option either to @command{guix-daemon}
3120 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3121 or to client tools such as @command{guix package}
3122 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3125 Substitute URLs can be either HTTP or HTTPS.
3126 HTTPS is recommended because communications are encrypted; conversely,
3127 using HTTP makes all communications visible to an eavesdropper, who
3128 could use the information gathered to determine, for instance, whether
3129 your system has unpatched security vulnerabilities.
3131 Substitutes from the official build farm are enabled by default when
3132 using the Guix System Distribution (@pxref{GNU Distribution}). However,
3133 they are disabled by default when using Guix on a foreign distribution,
3134 unless you have explicitly enabled them via one of the recommended
3135 installation steps (@pxref{Installation}). The following paragraphs
3136 describe how to enable or disable substitutes for the official build
3137 farm; the same procedure can also be used to enable substitutes for any
3138 other substitute server.
3140 @node Substitute Server Authorization
3141 @subsection Substitute Server Authorization
3144 @cindex substitutes, authorization thereof
3145 @cindex access control list (ACL), for substitutes
3146 @cindex ACL (access control list), for substitutes
3147 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3149 must add its public key to the access control list (ACL) of archive
3150 imports, using the @command{guix archive} command (@pxref{Invoking guix
3151 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3152 be compromised and to serve genuine substitutes.
3154 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3155 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3156 the installation prefix of Guix. If you installed Guix from source,
3157 make sure you checked the GPG signature of
3158 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3159 Then, you can run something like this:
3162 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3166 Similarly, the @file{hydra.gnu.org.pub} file contains the public key
3167 of an independent build farm also run by the project, reachable at
3168 @indicateurl{https://mirror.hydra.gnu.org}.
3171 Once this is in place, the output of a command like @code{guix build}
3172 should change from something like:
3175 $ guix build emacs --dry-run
3176 The following derivations would be built:
3177 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3178 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3179 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3180 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3188 $ guix build emacs --dry-run
3189 112.3 MB would be downloaded:
3190 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3191 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3192 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3193 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3198 This indicates that substitutes from @code{@value{SUBSTITUTE-SERVER}} are usable and
3199 will be downloaded, when possible, for future builds.
3201 @cindex substitutes, how to disable
3202 The substitute mechanism can be disabled globally by running
3203 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
3204 guix-daemon}). It can also be disabled temporarily by passing the
3205 @code{--no-substitutes} option to @command{guix package}, @command{guix
3206 build}, and other command-line tools.
3208 @node Substitute Authentication
3209 @subsection Substitute Authentication
3211 @cindex digital signatures
3212 Guix detects and raises an error when attempting to use a substitute
3213 that has been tampered with. Likewise, it ignores substitutes that are
3214 not signed, or that are not signed by one of the keys listed in the ACL.
3216 There is one exception though: if an unauthorized server provides
3217 substitutes that are @emph{bit-for-bit identical} to those provided by
3218 an authorized server, then the unauthorized server becomes eligible for
3219 downloads. For example, assume we have chosen two substitute servers
3223 --substitute-urls="https://a.example.org https://b.example.org"
3227 @cindex reproducible builds
3228 If the ACL contains only the key for @code{b.example.org}, and if
3229 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
3230 then Guix will download substitutes from @code{a.example.org} because it
3231 comes first in the list and can be considered a mirror of
3232 @code{b.example.org}. In practice, independent build machines usually
3233 produce the same binaries, thanks to bit-reproducible builds (see
3236 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3237 (in other words, the server is not authenticated), contrary to what
3238 HTTPS clients such as Web browsers usually do. This is because Guix
3239 authenticates substitute information itself, as explained above, which
3240 is what we care about (whereas X.509 certificates are about
3241 authenticating bindings between domain names and public keys.)
3243 @node Proxy Settings
3244 @subsection Proxy Settings
3247 Substitutes are downloaded over HTTP or HTTPS.
3248 The @code{http_proxy} environment
3249 variable can be set in the environment of @command{guix-daemon} and is
3250 honored for downloads of substitutes. Note that the value of
3251 @code{http_proxy} in the environment where @command{guix build},
3252 @command{guix package}, and other client commands are run has
3253 @emph{absolutely no effect}.
3255 @node Substitution Failure
3256 @subsection Substitution Failure
3258 Even when a substitute for a derivation is available, sometimes the
3259 substitution attempt will fail. This can happen for a variety of
3260 reasons: the substitute server might be offline, the substitute may
3261 recently have been deleted, the connection might have been interrupted,
3264 When substitutes are enabled and a substitute for a derivation is
3265 available, but the substitution attempt fails, Guix will attempt to
3266 build the derivation locally depending on whether or not
3267 @code{--fallback} was given (@pxref{fallback-option,, common build
3268 option @code{--fallback}}). Specifically, if @code{--fallback} was
3269 omitted, then no local build will be performed, and the derivation is
3270 considered to have failed. However, if @code{--fallback} was given,
3271 then Guix will attempt to build the derivation locally, and the success
3272 or failure of the derivation depends on the success or failure of the
3273 local build. Note that when substitutes are disabled or no substitute
3274 is available for the derivation in question, a local build will
3275 @emph{always} be performed, regardless of whether or not
3276 @code{--fallback} was given.
3278 To get an idea of how many substitutes are available right now, you can
3279 try running the @command{guix weather} command (@pxref{Invoking guix
3280 weather}). This command provides statistics on the substitutes provided
3283 @node On Trusting Binaries
3284 @subsection On Trusting Binaries
3286 @cindex trust, of pre-built binaries
3287 Today, each individual's control over their own computing is at the
3288 mercy of institutions, corporations, and groups with enough power and
3289 determination to subvert the computing infrastructure and exploit its
3290 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3291 convenient, we encourage users to also build on their own, or even run
3292 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3293 interesting target. One way to help is by publishing the software you
3294 build using @command{guix publish} so that others have one more choice
3295 of server to download substitutes from (@pxref{Invoking guix publish}).
3297 Guix has the foundations to maximize build reproducibility
3298 (@pxref{Features}). In most cases, independent builds of a given
3299 package or derivation should yield bit-identical results. Thus, through
3300 a diverse set of independent package builds, we can strengthen the
3301 integrity of our systems. The @command{guix challenge} command aims to
3302 help users assess substitute servers, and to assist developers in
3303 finding out about non-deterministic package builds (@pxref{Invoking guix
3304 challenge}). Similarly, the @option{--check} option of @command{guix
3305 build} allows users to check whether previously-installed substitutes
3306 are genuine by rebuilding them locally (@pxref{build-check,
3307 @command{guix build --check}}).
3309 In the future, we want Guix to have support to publish and retrieve
3310 binaries to/from other users, in a peer-to-peer fashion. If you would
3311 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3313 @node Packages with Multiple Outputs
3314 @section Packages with Multiple Outputs
3316 @cindex multiple-output packages
3317 @cindex package outputs
3320 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3321 source package leads to exactly one directory in the store. When running
3322 @command{guix package -i glibc}, one installs the default output of the
3323 GNU libc package; the default output is called @code{out}, but its name
3324 can be omitted as shown in this command. In this particular case, the
3325 default output of @code{glibc} contains all the C header files, shared
3326 libraries, static libraries, Info documentation, and other supporting
3329 Sometimes it is more appropriate to separate the various types of files
3330 produced from a single source package into separate outputs. For
3331 instance, the GLib C library (used by GTK+ and related packages)
3332 installs more than 20 MiB of reference documentation as HTML pages.
3333 To save space for users who do not need it, the documentation goes to a
3334 separate output, called @code{doc}. To install the main GLib output,
3335 which contains everything but the documentation, one would run:
3338 guix package -i glib
3341 @cindex documentation
3342 The command to install its documentation is:
3345 guix package -i glib:doc
3348 Some packages install programs with different ``dependency footprints''.
3349 For instance, the WordNet package installs both command-line tools and
3350 graphical user interfaces (GUIs). The former depend solely on the C
3351 library, whereas the latter depend on Tcl/Tk and the underlying X
3352 libraries. In this case, we leave the command-line tools in the default
3353 output, whereas the GUIs are in a separate output. This allows users
3354 who do not need the GUIs to save space. The @command{guix size} command
3355 can help find out about such situations (@pxref{Invoking guix size}).
3356 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3358 There are several such multiple-output packages in the GNU distribution.
3359 Other conventional output names include @code{lib} for libraries and
3360 possibly header files, @code{bin} for stand-alone programs, and
3361 @code{debug} for debugging information (@pxref{Installing Debugging
3362 Files}). The outputs of a packages are listed in the third column of
3363 the output of @command{guix package --list-available} (@pxref{Invoking
3367 @node Invoking guix gc
3368 @section Invoking @command{guix gc}
3370 @cindex garbage collector
3372 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3373 The @command{guix gc} command allows users to explicitly run the garbage
3374 collector to reclaim space from the @file{/gnu/store} directory. It is
3375 the @emph{only} way to remove files from @file{/gnu/store}---removing
3376 files or directories manually may break it beyond repair!
3379 @cindex garbage collector roots
3380 The garbage collector has a set of known @dfn{roots}: any file under
3381 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3382 cannot be deleted; any other file is considered @dfn{dead} and may be
3383 deleted. The set of garbage collector roots (``GC roots'' for short)
3384 includes default user profiles; by default, the symlinks under
3385 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3386 added with @command{guix build --root}, for example (@pxref{Invoking
3389 Prior to running @code{guix gc --collect-garbage} to make space, it is
3390 often useful to remove old generations from user profiles; that way, old
3391 package builds referenced by those generations can be reclaimed. This
3392 is achieved by running @code{guix package --delete-generations}
3393 (@pxref{Invoking guix package}).
3395 Our recommendation is to run a garbage collection periodically, or when
3396 you are short on disk space. For instance, to guarantee that at least
3397 5@tie{}GB are available on your disk, simply run:
3403 It is perfectly safe to run as a non-interactive periodic job
3404 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3405 Running @command{guix gc} with no arguments will collect as
3406 much garbage as it can, but that is often inconvenient: you may find
3407 yourself having to rebuild or re-download software that is ``dead'' from
3408 the GC viewpoint but that is necessary to build other pieces of
3409 software---e.g., the compiler tool chain.
3411 The @command{guix gc} command has three modes of operation: it can be
3412 used to garbage-collect any dead files (the default), to delete specific
3413 files (the @code{--delete} option), to print garbage-collector
3414 information, or for more advanced queries. The garbage collection
3415 options are as follows:
3418 @item --collect-garbage[=@var{min}]
3419 @itemx -C [@var{min}]
3420 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3421 sub-directories. This is the default operation when no option is
3424 When @var{min} is given, stop once @var{min} bytes have been collected.
3425 @var{min} may be a number of bytes, or it may include a unit as a
3426 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3427 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3429 When @var{min} is omitted, collect all the garbage.
3431 @item --free-space=@var{free}
3432 @itemx -F @var{free}
3433 Collect garbage until @var{free} space is available under
3434 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3435 as @code{500MiB}, as described above.
3437 When @var{free} or more is already available in @file{/gnu/store}, do
3438 nothing and exit immediately.
3442 Attempt to delete all the store files and directories specified as
3443 arguments. This fails if some of the files are not in the store, or if
3444 they are still live.
3446 @item --list-failures
3447 List store items corresponding to cached build failures.
3449 This prints nothing unless the daemon was started with
3450 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3451 @option{--cache-failures}}).
3453 @item --clear-failures
3454 Remove the specified store items from the failed-build cache.
3456 Again, this option only makes sense when the daemon is started with
3457 @option{--cache-failures}. Otherwise, it does nothing.
3460 Show the list of dead files and directories still present in the
3461 store---i.e., files and directories no longer reachable from any root.
3464 Show the list of live store files and directories.
3468 In addition, the references among existing store files can be queried:
3474 @cindex package dependencies
3475 List the references (respectively, the referrers) of store files given
3481 List the requisites of the store files passed as arguments. Requisites
3482 include the store files themselves, their references, and the references
3483 of these, recursively. In other words, the returned list is the
3484 @dfn{transitive closure} of the store files.
3486 @xref{Invoking guix size}, for a tool to profile the size of the closure
3487 of an element. @xref{Invoking guix graph}, for a tool to visualize
3488 the graph of references.
3492 Return the derivation(s) leading to the given store items
3493 (@pxref{Derivations}).
3495 For example, this command:
3498 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3502 returns the @file{.drv} file(s) leading to the @code{emacs} package
3503 installed in your profile.
3505 Note that there may be zero matching @file{.drv} files, for instance
3506 because these files have been garbage-collected. There can also be more
3507 than one matching @file{.drv} due to fixed-output derivations.
3510 Lastly, the following options allow you to check the integrity of the
3511 store and to control disk usage.
3515 @item --verify[=@var{options}]
3516 @cindex integrity, of the store
3517 @cindex integrity checking
3518 Verify the integrity of the store.
3520 By default, make sure that all the store items marked as valid in the
3521 database of the daemon actually exist in @file{/gnu/store}.
3523 When provided, @var{options} must be a comma-separated list containing one
3524 or more of @code{contents} and @code{repair}.
3526 When passing @option{--verify=contents}, the daemon computes the
3527 content hash of each store item and compares it against its hash in the
3528 database. Hash mismatches are reported as data corruptions. Because it
3529 traverses @emph{all the files in the store}, this command can take a
3530 long time, especially on systems with a slow disk drive.
3532 @cindex repairing the store
3533 @cindex corruption, recovering from
3534 Using @option{--verify=repair} or @option{--verify=contents,repair}
3535 causes the daemon to try to repair corrupt store items by fetching
3536 substitutes for them (@pxref{Substitutes}). Because repairing is not
3537 atomic, and thus potentially dangerous, it is available only to the
3538 system administrator. A lightweight alternative, when you know exactly
3539 which items in the store are corrupt, is @command{guix build --repair}
3540 (@pxref{Invoking guix build}).
3543 @cindex deduplication
3544 Optimize the store by hard-linking identical files---this is
3545 @dfn{deduplication}.
3547 The daemon performs deduplication after each successful build or archive
3548 import, unless it was started with @code{--disable-deduplication}
3549 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
3550 this option is primarily useful when the daemon was running with
3551 @code{--disable-deduplication}.
3555 @node Invoking guix pull
3556 @section Invoking @command{guix pull}
3558 @cindex upgrading Guix
3559 @cindex updating Guix
3560 @cindex @command{guix pull}
3562 Packages are installed or upgraded to the latest version available in
3563 the distribution currently available on your local machine. To update
3564 that distribution, along with the Guix tools, you must run @command{guix
3565 pull}: the command downloads the latest Guix source code and package
3566 descriptions, and deploys it. Source code is downloaded from a
3567 @uref{https://git-scm.com, Git} repository, by default the official
3568 GNU@tie{}Guix repository, though this can be customized.
3570 On completion, @command{guix package} will use packages and package
3571 versions from this just-retrieved copy of Guix. Not only that, but all
3572 the Guix commands and Scheme modules will also be taken from that latest
3573 version. New @command{guix} sub-commands added by the update also
3576 Any user can update their Guix copy using @command{guix pull}, and the
3577 effect is limited to the user who run @command{guix pull}. For
3578 instance, when user @code{root} runs @command{guix pull}, this has no
3579 effect on the version of Guix that user @code{alice} sees, and vice
3582 The result of running @command{guix pull} is a @dfn{profile} available
3583 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3584 make sure to add it to the beginning of your search path so that you use
3585 the latest version, and similarly for the Info manual
3586 (@pxref{Documentation}):
3589 export PATH="$HOME/.config/guix/current/bin:$PATH"
3590 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3593 The @code{--list-generations} or @code{-l} option lists past generations
3594 produced by @command{guix pull}, along with details about their provenance:
3598 Generation 1 Jun 10 2018 00:18:18
3600 repository URL: https://git.savannah.gnu.org/git/guix.git
3601 branch: origin/master
3602 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3604 Generation 2 Jun 11 2018 11:02:49
3606 repository URL: https://git.savannah.gnu.org/git/guix.git
3607 branch: origin/master
3608 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3609 2 new packages: keepalived, libnfnetlink
3610 6 packages upgraded: emacs-nix-mode@@2.0.4,
3611 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3612 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3614 Generation 3 Jun 13 2018 23:31:07 (current)
3616 repository URL: https://git.savannah.gnu.org/git/guix.git
3617 branch: origin/master
3618 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3619 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3620 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3623 @ref{Invoking guix describe, @command{guix describe}}, for other ways to
3624 describe the current status of Guix.
3626 This @code{~/.config/guix/current} profile works like any other profile
3627 created by @command{guix package} (@pxref{Invoking guix package}). That
3628 is, you can list generations, roll back to the previous
3629 generation---i.e., the previous Guix---and so on:
3632 $ guix package -p ~/.config/guix/current --roll-back
3633 switched from generation 3 to 2
3634 $ guix package -p ~/.config/guix/current --delete-generations=1
3635 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3638 The @command{guix pull} command is usually invoked with no arguments,
3639 but it supports the following options:
3642 @item --url=@var{url}
3643 @itemx --commit=@var{commit}
3644 @itemx --branch=@var{branch}
3645 Download code from the specified @var{url}, at the given @var{commit} (a valid
3646 Git commit ID represented as a hexadecimal string), or @var{branch}.
3648 @cindex @file{channels.scm}, configuration file
3649 @cindex configuration file for channels
3650 These options are provided for convenience, but you can also specify your
3651 configuration in the @file{~/.config/guix/channels.scm} file or using the
3652 @option{--channels} option (see below).
3654 @item --channels=@var{file}
3655 @itemx -C @var{file}
3656 Read the list of channels from @var{file} instead of
3657 @file{~/.config/guix/channels.scm}. @var{file} must contain Scheme code that
3658 evaluates to a list of channel objects. @xref{Channels}, for more
3661 @item --list-generations[=@var{pattern}]
3662 @itemx -l [@var{pattern}]
3663 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3664 is provided, the subset of generations that match @var{pattern}.
3665 The syntax of @var{pattern} is the same as with @code{guix package
3666 --list-generations} (@pxref{Invoking guix package}).
3668 @ref{Invoking guix describe}, for a way to display information about the
3669 current generation only.
3671 @item --profile=@var{profile}
3672 @itemx -p @var{profile}
3673 Use @var{profile} instead of @file{~/.config/guix/current}.
3677 Show which channel commit(s) would be used and what would be built or
3678 substituted but do not actually do it.
3680 @item --system=@var{system}
3681 @itemx -s @var{system}
3682 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3683 the system type of the build host.
3686 Produce verbose output, writing build logs to the standard error output.
3689 Use the bootstrap Guile to build the latest Guix. This option is only
3690 useful to Guix developers.
3693 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3694 repository and branch to pull from, as well as @emph{additional} repositories
3695 containing package modules that should be deployed. @xref{Channels}, for more
3698 In addition, @command{guix pull} supports all the common build options
3699 (@pxref{Common Build Options}).
3705 @cindex @file{channels.scm}, configuration file
3706 @cindex configuration file for channels
3707 @cindex @command{guix pull}, configuration file
3708 @cindex configuration of @command{guix pull}
3709 Guix and its package collection are updated by running @command{guix pull}
3710 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3711 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3712 customized by defining @dfn{channels} in the
3713 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3714 of a Git repository to be deployed, and @command{guix pull} can be instructed
3715 to pull from one or more channels. In other words, channels can be used to
3716 @emph{customize} and to @emph{extend} Guix, as we will see below.
3718 @subsection Using a Custom Guix Channel
3720 The channel called @code{guix} specifies where Guix itself---its command-line
3721 tools as well as its package collection---should be downloaded. For instance,
3722 suppose you want to update from your own copy of the Guix repository at
3723 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3724 write in @code{~/.config/guix/channels.scm} this specification:
3727 ;; Tell 'guix pull' to use my own repo.
3730 (url "https://example.org/my-guix.git")
3731 (branch "super-hacks")))
3735 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3736 branch of the repository at @code{example.org}.
3738 @subsection Specifying Additional Channels
3740 @cindex extending the package collection (channels)
3741 @cindex personal packages (channels)
3742 @cindex channels, for personal packages
3743 You can also specify @emph{additional channels} to pull from. Let's say you
3744 have a bunch of custom package variants or personal packages that you think
3745 would make little sense to contribute to the Guix project, but would like to
3746 have these packages transparently available to you at the command line. You
3747 would first write modules containing those package definitions (@pxref{Package
3748 Modules}), maintain them in a Git repository, and then you and anyone else can
3749 use it as an additional channel to get packages from. Neat, no?
3751 @c What follows stems from discussions at
3752 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3753 @c earlier discussions on guix-devel@gnu.org.
3755 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3756 publish your personal channel to the world, we would like to share a few words
3761 Before publishing a channel, please consider contributing your package
3762 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3763 to free software of all sorts, and packages in Guix proper are readily
3764 available to all Guix users and benefit from the project's quality assurance
3768 When you maintain package definitions outside Guix, we, Guix developers,
3769 consider that @emph{the compatibility burden is on you}. Remember that
3770 package modules and package definitions are just Scheme code that uses various
3771 programming interfaces (APIs). We want to remain free to change these APIs to
3772 keep improving Guix, possibly in ways that break your channel. We never
3773 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3777 Corollary: if you're using an external channel and that channel breaks, please
3778 @emph{report the issue to the channel authors}, not to the Guix project.
3781 You've been warned! Having said this, we believe external channels are a
3782 practical way to exert your freedom to augment Guix' package collection and to
3783 share your improvements, which are basic tenets of
3784 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3785 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3788 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
3789 @command{guix pull} to pull from it @emph{in addition} to the default Guix
3792 @vindex %default-channels
3794 ;; Add my personal packages to those Guix provides.
3796 (name 'my-personal-packages)
3797 (url "https://example.org/personal-packages.git"))
3802 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3803 add a channel the list of channels that the variable @code{%default-channels}
3804 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3805 Manual}). With this file in place, @command{guix pull} builds not only Guix
3806 but also the package modules from your own repository. The result in
3807 @file{~/.config/guix/current} is the union of Guix with your own package
3811 $ guix pull --list-generations
3813 Generation 19 Aug 27 2018 16:20:48
3815 repository URL: https://git.savannah.gnu.org/git/guix.git
3817 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
3818 my-personal-packages dd3df5e
3819 repository URL: https://example.org/personal-packages.git
3821 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
3822 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
3823 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
3827 The output of @command{guix pull} above shows that Generation@tie{}19 includes
3828 both Guix and packages from the @code{my-personal-packages} channel. Among
3829 the new and upgraded packages that are listed, some like @code{my-gimp} and
3830 @code{my-emacs-with-cool-features} might come from
3831 @code{my-personal-packages}, while others come from the Guix default channel.
3833 To create a channel, create a Git repository containing your own package
3834 modules and make it available. The repository can contain anything, but a
3835 useful channel will contain Guile modules that export packages. Once you
3836 start using a channel, Guix will behave as if the root directory of that
3837 channel's Git repository has been added to the Guile load path (@pxref{Load
3838 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
3839 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
3840 module, then the module will be available under the name @code{(my-packages
3841 my-tools)}, and you will be able to use it like any other module
3842 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
3844 @cindex dependencies, channels
3845 @cindex meta-data, channels
3846 @subsection Declaring Channel Dependencies
3848 Channel authors may decide to augment a package collection provided by other
3849 channels. They can declare their channel to be dependent on other channels in
3850 a meta-data file @file{.guix-channel}, which is to be placed in the root of
3851 the channel repository.
3853 The meta-data file should contain a simple S-expression like this:
3860 (name some-collection)
3861 (url "https://example.org/first-collection.git"))
3863 (name some-other-collection)
3864 (url "https://example.org/second-collection.git")
3865 (branch "testing"))))
3868 In the above example this channel is declared to depend on two other channels,
3869 which will both be fetched automatically. The modules provided by the channel
3870 will be compiled in an environment where the modules of all these declared
3871 channels are available.
3873 For the sake of reliability and maintainability, you should avoid dependencies
3874 on channels that you don't control, and you should aim to keep the number of
3875 dependencies to a minimum.
3877 @subsection Replicating Guix
3879 @cindex pinning, channels
3880 @cindex replicating Guix
3881 @cindex reproducibility, of Guix
3882 The @command{guix pull --list-generations} output above shows precisely which
3883 commits were used to build this instance of Guix. We can thus replicate it,
3884 say, on another machine, by providing a channel specification in
3885 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
3888 ;; Deploy specific commits of my channels of interest.
3891 (url "https://git.savannah.gnu.org/git/guix.git")
3892 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
3894 (name 'my-personal-packages)
3895 (url "https://example.org/personal-packages.git")
3896 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
3899 The @command{guix describe --format=channels} command can even generate this
3900 list of channels directly (@pxref{Invoking guix describe}).
3902 At this point the two machines run the @emph{exact same Guix}, with access to
3903 the @emph{exact same packages}. The output of @command{guix build gimp} on
3904 one machine will be exactly the same, bit for bit, as the output of the same
3905 command on the other machine. It also means both machines have access to all
3906 the source code of Guix and, transitively, to all the source code of every
3909 This gives you super powers, allowing you to track the provenance of binary
3910 artifacts with very fine grain, and to reproduce software environments at
3911 will---some sort of ``meta reproducibility'' capabilities, if you will.
3912 @xref{Inferiors}, for another way to take advantage of these super powers.
3917 @c TODO: Remove this once we're more confident about API stability.
3919 The functionality described here is a ``technology preview'' as of version
3920 @value{VERSION}. As such, the interface is subject to change.
3924 @cindex composition of Guix revisions
3925 Sometimes you might need to mix packages from the revision of Guix you're
3926 currently running with packages available in a different revision of Guix.
3927 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
3928 revisions in arbitrary ways.
3930 @cindex inferior packages
3931 Technically, an ``inferior'' is essentially a separate Guix process connected
3932 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
3933 @code{(guix inferior)} module allows you to create inferiors and to
3934 communicate with them. It also provides a high-level interface to browse and
3935 manipulate the packages that an inferior provides---@dfn{inferior packages}.
3937 When combined with channels (@pxref{Channels}), inferiors provide a simple way
3938 to interact with a separate revision of Guix. For example, let's assume you
3939 want to install in your profile the current @code{guile} package, along with
3940 the @code{guile-json} as it existed in an older revision of Guix---perhaps
3941 because the newer @code{guile-json} has an incompatible API and you want to
3942 run your code against the old API@. To do that, you could write a manifest for
3943 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
3944 manifest, you would create an inferior for that old Guix revision you care
3945 about, and you would look up the @code{guile-json} package in the inferior:
3948 (use-modules (guix inferior) (guix channels)
3949 (srfi srfi-1)) ;for 'first'
3952 ;; This is the old revision from which we want to
3953 ;; extract guile-json.
3956 (url "https://git.savannah.gnu.org/git/guix.git")
3958 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
3961 ;; An inferior representing the above revision.
3962 (inferior-for-channels channels))
3964 ;; Now create a manifest with the current "guile" package
3965 ;; and the old "guile-json" package.
3967 (list (first (lookup-inferior-packages inferior "guile-json"))
3968 (specification->package "guile")))
3971 On its first run, @command{guix package --manifest} might have to build the
3972 channel you specified before it can create the inferior; subsequent runs will
3973 be much faster because the Guix revision will be cached.
3975 The @code{(guix inferior)} module provides the following procedures to open an
3978 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
3979 [#:cache-directory] [#:ttl]
3980 Return an inferior for @var{channels}, a list of channels. Use the cache at
3981 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
3982 This procedure opens a new connection to the build daemon.
3984 As a side effect, this procedure may build or substitute binaries for
3985 @var{channels}, which can take time.
3988 @deffn {Scheme Procedure} open-inferior @var{directory} @
3989 [#:command "bin/guix"]
3990 Open the inferior Guix in @var{directory}, running
3991 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
3992 the inferior could not be launched.
3995 @cindex inferior packages
3996 The procedures listed below allow you to obtain and manipulate inferior
3999 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4000 Return the list of packages known to @var{inferior}.
4003 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4005 Return the sorted list of inferior packages matching @var{name} in
4006 @var{inferior}, with highest version numbers first. If @var{version} is true,
4007 return only packages with a version number prefixed by @var{version}.
4010 @deffn {Scheme Procedure} inferior-package? @var{obj}
4011 Return true if @var{obj} is an inferior package.
4014 @deffn {Scheme Procedure} inferior-package-name @var{package}
4015 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4016 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4017 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4018 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4019 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4020 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4021 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4022 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4023 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4024 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4025 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4026 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4027 These procedures are the counterpart of package record accessors
4028 (@pxref{package Reference}). Most of them work by querying the inferior
4029 @var{package} comes from, so the inferior must still be live when you call
4033 Inferior packages can be used transparently like any other package or
4034 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4035 transparently handled by the @code{packages->manifest} procedure, which is
4036 commonly use in manifests (@pxref{Invoking guix package, the
4037 @option{--manifest} option of @command{guix package}}). Thus you can insert
4038 an inferior package pretty much anywhere you would insert a regular package:
4039 in manifests, in the @code{packages} field of your @code{operating-system}
4040 declaration, and so on.
4042 @node Invoking guix describe
4043 @section Invoking @command{guix describe}
4045 @cindex reproducibility
4046 @cindex replicating Guix
4047 Often you may want to answer questions like: ``Which revision of Guix am I
4048 using?'' or ``Which channels am I using?'' This is useful information in many
4049 situations: if you want to @emph{replicate} an environment on a different
4050 machine or user account, if you want to report a bug or to determine what
4051 change in the channels you are using caused it, or if you want to record your
4052 system state for reproducibility purposes. The @command{guix describe}
4053 command answers these questions.
4055 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4056 displays the channel(s) that it was built from, including their repository URL
4057 and commit IDs (@pxref{Channels}):
4061 Generation 10 Sep 03 2018 17:32:44 (current)
4063 repository URL: https://git.savannah.gnu.org/git/guix.git
4065 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4068 If you're familiar with the Git version control system, this is similar in
4069 spirit to @command{git describe}; the output is also similar to that of
4070 @command{guix pull --list-generations}, but limited to the current generation
4071 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4072 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4073 information is all it takes to describe the revision of Guix you're using, and
4074 also to replicate it.
4076 To make it easier to replicate Guix, @command{guix describe} can also be asked
4077 to return a list of channels instead of the human-readable description above:
4080 $ guix describe -f channels
4083 (url "https://git.savannah.gnu.org/git/guix.git")
4085 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4089 You can save this to a file and feed it to @command{guix pull -C} on some
4090 other machine or at a later point in time, which will instantiate @emph{this
4091 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4092 From there on, since you're able to deploy the same revision of Guix, you can
4093 just as well @emph{replicate a complete software environment}. We humbly
4094 think that this is @emph{awesome}, and we hope you'll like it too!
4096 The details of the options supported by @command{guix describe} are as
4100 @item --format=@var{format}
4101 @itemx -f @var{format}
4102 Produce output in the specified @var{format}, one of:
4106 produce human-readable output;
4108 produce a list of channel specifications that can be passed to @command{guix
4109 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4113 produce a list of channel specifications in JSON format;
4115 produce a list of channel specifications in Recutils format.
4118 @item --profile=@var{profile}
4119 @itemx -p @var{profile}
4120 Display information about @var{profile}.
4123 @node Invoking guix archive
4124 @section Invoking @command{guix archive}
4126 @cindex @command{guix archive}
4128 The @command{guix archive} command allows users to @dfn{export} files
4129 from the store into a single archive, and to later @dfn{import} them on
4130 a machine that runs Guix.
4131 In particular, it allows store files to be transferred from one machine
4132 to the store on another machine.
4135 If you're looking for a way to produce archives in a format suitable for
4136 tools other than Guix, @pxref{Invoking guix pack}.
4139 @cindex exporting store items
4140 To export store files as an archive to standard output, run:
4143 guix archive --export @var{options} @var{specifications}...
4146 @var{specifications} may be either store file names or package
4147 specifications, as for @command{guix package} (@pxref{Invoking guix
4148 package}). For instance, the following command creates an archive
4149 containing the @code{gui} output of the @code{git} package and the main
4150 output of @code{emacs}:
4153 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4156 If the specified packages are not built yet, @command{guix archive}
4157 automatically builds them. The build process may be controlled with the
4158 common build options (@pxref{Common Build Options}).
4160 To transfer the @code{emacs} package to a machine connected over SSH,
4164 guix archive --export -r emacs | ssh the-machine guix archive --import
4168 Similarly, a complete user profile may be transferred from one machine
4169 to another like this:
4172 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4173 ssh the-machine guix-archive --import
4177 However, note that, in both examples, all of @code{emacs} and the
4178 profile as well as all of their dependencies are transferred (due to
4179 @code{-r}), regardless of what is already available in the store on the
4180 target machine. The @code{--missing} option can help figure out which
4181 items are missing from the target store. The @command{guix copy}
4182 command simplifies and optimizes this whole process, so this is probably
4183 what you should use in this case (@pxref{Invoking guix copy}).
4185 @cindex nar, archive format
4186 @cindex normalized archive (nar)
4187 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4188 comparable in spirit to `tar', but with differences
4189 that make it more appropriate for our purposes. First, rather than
4190 recording all Unix metadata for each file, the nar format only mentions
4191 the file type (regular, directory, or symbolic link); Unix permissions
4192 and owner/group are dismissed. Second, the order in which directory
4193 entries are stored always follows the order of file names according to
4194 the C locale collation order. This makes archive production fully
4197 When exporting, the daemon digitally signs the contents of the archive,
4198 and that digital signature is appended. When importing, the daemon
4199 verifies the signature and rejects the import in case of an invalid
4200 signature or if the signing key is not authorized.
4201 @c FIXME: Add xref to daemon doc about signatures.
4203 The main options are:
4207 Export the specified store files or packages (see below.) Write the
4208 resulting archive to the standard output.
4210 Dependencies are @emph{not} included in the output, unless
4211 @code{--recursive} is passed.
4215 When combined with @code{--export}, this instructs @command{guix
4216 archive} to include dependencies of the given items in the archive.
4217 Thus, the resulting archive is self-contained: it contains the closure
4218 of the exported store items.
4221 Read an archive from the standard input, and import the files listed
4222 therein into the store. Abort if the archive has an invalid digital
4223 signature, or if it is signed by a public key not among the authorized
4224 keys (see @code{--authorize} below.)
4227 Read a list of store file names from the standard input, one per line,
4228 and write on the standard output the subset of these files missing from
4231 @item --generate-key[=@var{parameters}]
4232 @cindex signing, archives
4233 Generate a new key pair for the daemon. This is a prerequisite before
4234 archives can be exported with @code{--export}. Note that this operation
4235 usually takes time, because it needs to gather enough entropy to
4236 generate the key pair.
4238 The generated key pair is typically stored under @file{/etc/guix}, in
4239 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4240 key, which must be kept secret.) When @var{parameters} is omitted,
4241 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4242 versions before 1.6.0, it is a 4096-bit RSA key.
4243 Alternatively, @var{parameters} can specify
4244 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4245 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4246 Libgcrypt Reference Manual}).
4249 @cindex authorizing, archives
4250 Authorize imports signed by the public key passed on standard input.
4251 The public key must be in ``s-expression advanced format''---i.e., the
4252 same format as the @file{signing-key.pub} file.
4254 The list of authorized keys is kept in the human-editable file
4255 @file{/etc/guix/acl}. The file contains
4256 @url{http://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4257 s-expressions''} and is structured as an access-control list in the
4258 @url{http://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4261 @item --extract=@var{directory}
4262 @itemx -x @var{directory}
4263 Read a single-item archive as served by substitute servers
4264 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4265 low-level operation needed in only very narrow use cases; see below.
4267 For example, the following command extracts the substitute for Emacs
4268 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4272 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
4273 | bunzip2 | guix archive -x /tmp/emacs
4276 Single-item archives are different from multiple-item archives produced
4277 by @command{guix archive --export}; they contain a single store item,
4278 and they do @emph{not} embed a signature. Thus this operation does
4279 @emph{no} signature verification and its output should be considered
4282 The primary purpose of this operation is to facilitate inspection of
4283 archive contents coming from possibly untrusted substitute servers.
4288 @c *********************************************************************
4290 @chapter Development
4292 @cindex software development
4293 If you are a software developer, Guix provides tools that you should find
4294 helpful---independently of the language you're developing in. This is what
4295 this chapter is about.
4297 The @command{guix environment} command provides a convenient way to set up
4298 @dfn{development environments} containing all the dependencies and tools
4299 necessary to work on the software package of your choice. The @command{guix
4300 pack} command allows you to create @dfn{application bundles} that can be
4301 easily distributed to users who do not run Guix.
4304 * Invoking guix environment:: Setting up development environments.
4305 * Invoking guix pack:: Creating software bundles.
4308 @node Invoking guix environment
4309 @section Invoking @command{guix environment}
4311 @cindex reproducible build environments
4312 @cindex development environments
4313 @cindex @command{guix environment}
4314 @cindex environment, package build environment
4315 The purpose of @command{guix environment} is to assist hackers in
4316 creating reproducible development environments without polluting their
4317 package profile. The @command{guix environment} tool takes one or more
4318 packages, builds all of their inputs, and creates a shell
4319 environment to use them.
4321 The general syntax is:
4324 guix environment @var{options} @var{package}@dots{}
4327 The following example spawns a new shell set up for the development of
4331 guix environment guile
4334 If the needed dependencies are not built yet, @command{guix environment}
4335 automatically builds them. The environment of the new shell is an augmented
4336 version of the environment that @command{guix environment} was run in.
4337 It contains the necessary search paths for building the given package
4338 added to the existing environment variables. To create a ``pure''
4339 environment, in which the original environment variables have been unset,
4340 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
4341 environment variables such as @code{PATH} in their @file{~/.bashrc}
4342 file. As a consequence, when @code{guix environment} launches it, Bash
4343 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
4344 environment variables. It is an error to define such environment
4345 variables in @file{.bashrc}; instead, they should be defined in
4346 @file{.bash_profile}, which is sourced only by log-in shells.
4347 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
4348 details on Bash start-up files.}.
4350 @vindex GUIX_ENVIRONMENT
4351 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
4352 variable in the shell it spawns; its value is the file name of the
4353 profile of this environment. This allows users to, say, define a
4354 specific prompt for development environments in their @file{.bashrc}
4355 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4358 if [ -n "$GUIX_ENVIRONMENT" ]
4360 export PS1="\u@@\h \w [dev]\$ "
4365 ...@: or to browse the profile:
4368 $ ls "$GUIX_ENVIRONMENT/bin"
4371 Additionally, more than one package may be specified, in which case the
4372 union of the inputs for the given packages are used. For example, the
4373 command below spawns a shell where all of the dependencies of both Guile
4374 and Emacs are available:
4377 guix environment guile emacs
4380 Sometimes an interactive shell session is not desired. An arbitrary
4381 command may be invoked by placing the @code{--} token to separate the
4382 command from the rest of the arguments:
4385 guix environment guile -- make -j4
4388 In other situations, it is more convenient to specify the list of
4389 packages needed in the environment. For example, the following command
4390 runs @command{python} from an environment containing Python@tie{}2.7 and
4394 guix environment --ad-hoc python2-numpy python-2.7 -- python
4397 Furthermore, one might want the dependencies of a package and also some
4398 additional packages that are not build-time or runtime dependencies, but
4399 are useful when developing nonetheless. Because of this, the
4400 @code{--ad-hoc} flag is positional. Packages appearing before
4401 @code{--ad-hoc} are interpreted as packages whose dependencies will be
4402 added to the environment. Packages appearing after are interpreted as
4403 packages that will be added to the environment directly. For example,
4404 the following command creates a Guix development environment that
4405 additionally includes Git and strace:
4408 guix environment guix --ad-hoc git strace
4411 Sometimes it is desirable to isolate the environment as much as
4412 possible, for maximal purity and reproducibility. In particular, when
4413 using Guix on a host distro that is not Guix System, it is desirable to
4414 prevent access to @file{/usr/bin} and other system-wide resources from
4415 the development environment. For example, the following command spawns
4416 a Guile REPL in a ``container'' where only the store and the current
4417 working directory are mounted:
4420 guix environment --ad-hoc --container guile -- guile
4424 The @code{--container} option requires Linux-libre 3.19 or newer.
4427 The available options are summarized below.
4430 @item --root=@var{file}
4431 @itemx -r @var{file}
4432 @cindex persistent environment
4433 @cindex garbage collector root, for environments
4434 Make @var{file} a symlink to the profile for this environment, and
4435 register it as a garbage collector root.
4437 This is useful if you want to protect your environment from garbage
4438 collection, to make it ``persistent''.
4440 When this option is omitted, the environment is protected from garbage
4441 collection only for the duration of the @command{guix environment}
4442 session. This means that next time you recreate the same environment,
4443 you could have to rebuild or re-download packages. @xref{Invoking guix
4444 gc}, for more on GC roots.
4446 @item --expression=@var{expr}
4447 @itemx -e @var{expr}
4448 Create an environment for the package or list of packages that
4449 @var{expr} evaluates to.
4451 For example, running:
4454 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4457 starts a shell with the environment for this specific variant of the
4463 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4466 starts a shell with all the base system packages available.
4468 The above commands only use the default output of the given packages.
4469 To select other outputs, two element tuples can be specified:
4472 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4475 @item --load=@var{file}
4476 @itemx -l @var{file}
4477 Create an environment for the package or list of packages that the code
4478 within @var{file} evaluates to.
4480 As an example, @var{file} might contain a definition like this
4481 (@pxref{Defining Packages}):
4484 @verbatiminclude environment-gdb.scm
4487 @item --manifest=@var{file}
4488 @itemx -m @var{file}
4489 Create an environment for the packages contained in the manifest object
4490 returned by the Scheme code in @var{file}.
4492 This is similar to the same-named option in @command{guix package}
4493 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4497 Include all specified packages in the resulting environment, as if an
4498 @i{ad hoc} package were defined with them as inputs. This option is
4499 useful for quickly creating an environment without having to write a
4500 package expression to contain the desired inputs.
4502 For instance, the command:
4505 guix environment --ad-hoc guile guile-sdl -- guile
4508 runs @command{guile} in an environment where Guile and Guile-SDL are
4511 Note that this example implicitly asks for the default output of
4512 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4513 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4514 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4516 This option may be composed with the default behavior of @command{guix
4517 environment}. Packages appearing before @code{--ad-hoc} are interpreted
4518 as packages whose dependencies will be added to the environment, the
4519 default behavior. Packages appearing after are interpreted as packages
4520 that will be added to the environment directly.
4523 Unset existing environment variables when building the new environment, except
4524 those specified with @option{--preserve} (see below.) This has the effect of
4525 creating an environment in which search paths only contain package inputs.
4527 @item --preserve=@var{regexp}
4528 @itemx -E @var{regexp}
4529 When used alongside @option{--pure}, preserve the environment variables
4530 matching @var{regexp}---in other words, put them on a ``white list'' of
4531 environment variables that must be preserved. This option can be repeated
4535 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4539 This example runs @command{mpirun} in a context where the only environment
4540 variables defined are @code{PATH}, environment variables whose name starts
4541 with @code{SLURM}, as well as the usual ``precious'' variables (@code{HOME},
4544 @item --search-paths
4545 Display the environment variable definitions that make up the
4548 @item --system=@var{system}
4549 @itemx -s @var{system}
4550 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4555 Run @var{command} within an isolated container. The current working
4556 directory outside the container is mapped inside the container.
4557 Additionally, unless overridden with @code{--user}, a dummy home
4558 directory is created that matches the current user's home directory, and
4559 @file{/etc/passwd} is configured accordingly. The spawned process runs
4560 as the current user outside the container, but has root privileges in
4561 the context of the container.
4565 For containers, share the network namespace with the host system.
4566 Containers created without this flag only have access to the loopback
4569 @item --link-profile
4571 For containers, link the environment profile to
4572 @file{~/.guix-profile} within the container. This is equivalent to
4573 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
4574 within the container. Linking will fail and abort the environment if
4575 the directory already exists, which will certainly be the case if
4576 @command{guix environment} was invoked in the user's home directory.
4578 Certain packages are configured to look in
4579 @code{~/.guix-profile} for configuration files and data;@footnote{For
4580 example, the @code{fontconfig} package inspects
4581 @file{~/.guix-profile/share/fonts} for additional fonts.}
4582 @code{--link-profile} allows these programs to behave as expected within
4585 @item --user=@var{user}
4586 @itemx -u @var{user}
4587 For containers, use the username @var{user} in place of the current
4588 user. The generated @file{/etc/passwd} entry within the container will
4589 contain the name @var{user}; the home directory will be
4590 @file{/home/USER}; and no user GECOS data will be copied. @var{user}
4591 need not exist on the system.
4593 Additionally, any shared or exposed path (see @code{--share} and
4594 @code{--expose} respectively) whose target is within the current user's
4595 home directory will be remapped relative to @file{/home/USER}; this
4596 includes the automatic mapping of the current working directory.
4599 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4601 guix environment --container --user=foo \
4602 --expose=$HOME/test \
4603 --expose=/tmp/target=$HOME/target
4606 While this will limit the leaking of user identity through home paths
4607 and each of the user fields, this is only one useful component of a
4608 broader privacy/anonymity solution---not one in and of itself.
4610 @item --expose=@var{source}[=@var{target}]
4611 For containers, expose the file system @var{source} from the host system
4612 as the read-only file system @var{target} within the container. If
4613 @var{target} is not specified, @var{source} is used as the target mount
4614 point in the container.
4616 The example below spawns a Guile REPL in a container in which the user's
4617 home directory is accessible read-only via the @file{/exchange}
4621 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
4624 @item --share=@var{source}[=@var{target}]
4625 For containers, share the file system @var{source} from the host system
4626 as the writable file system @var{target} within the container. If
4627 @var{target} is not specified, @var{source} is used as the target mount
4628 point in the container.
4630 The example below spawns a Guile REPL in a container in which the user's
4631 home directory is accessible for both reading and writing via the
4632 @file{/exchange} directory:
4635 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
4639 @command{guix environment}
4640 also supports all of the common build options that @command{guix
4641 build} supports (@pxref{Common Build Options}) as well as package
4642 transformation options (@pxref{Package Transformation Options}).
4644 @node Invoking guix pack
4645 @section Invoking @command{guix pack}
4647 Occasionally you want to pass software to people who are not (yet!)
4648 lucky enough to be using Guix. You'd tell them to run @command{guix
4649 package -i @var{something}}, but that's not possible in this case. This
4650 is where @command{guix pack} comes in.
4653 If you are looking for ways to exchange binaries among machines that
4654 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
4655 publish}, and @ref{Invoking guix archive}.
4660 @cindex application bundle
4661 @cindex software bundle
4662 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
4663 @dfn{software bundle}: it creates a tarball or some other archive
4664 containing the binaries of the software you're interested in, and all
4665 its dependencies. The resulting archive can be used on any machine that
4666 does not have Guix, and people can run the exact same binaries as those
4667 you have with Guix. The pack itself is created in a bit-reproducible
4668 fashion, so anyone can verify that it really contains the build results
4669 that you pretend to be shipping.
4671 For example, to create a bundle containing Guile, Emacs, Geiser, and all
4672 their dependencies, you can run:
4675 $ guix pack guile emacs geiser
4677 /gnu/store/@dots{}-pack.tar.gz
4680 The result here is a tarball containing a @file{/gnu/store} directory
4681 with all the relevant packages. The resulting tarball contains a
4682 @dfn{profile} with the three packages of interest; the profile is the
4683 same as would be created by @command{guix package -i}. It is this
4684 mechanism that is used to create Guix's own standalone binary tarball
4685 (@pxref{Binary Installation}).
4687 Users of this pack would have to run
4688 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
4689 find inconvenient. To work around it, you can create, say, a
4690 @file{/opt/gnu/bin} symlink to the profile:
4693 guix pack -S /opt/gnu/bin=bin guile emacs geiser
4697 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
4699 @cindex relocatable binaries, with @command{guix pack}
4700 What if the recipient of your pack does not have root privileges on
4701 their machine, and thus cannot unpack it in the root file system? In
4702 that case, you will want to use the @code{--relocatable} option (see
4703 below). This option produces @dfn{relocatable binaries}, meaning they
4704 they can be placed anywhere in the file system hierarchy: in the example
4705 above, users can unpack your tarball in their home directory and
4706 directly run @file{./opt/gnu/bin/guile}.
4708 @cindex Docker, build an image with guix pack
4709 Alternatively, you can produce a pack in the Docker image format using
4710 the following command:
4713 guix pack -f docker guile emacs geiser
4717 The result is a tarball that can be passed to the @command{docker load}
4719 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
4720 documentation} for more information.
4722 @cindex Singularity, build an image with guix pack
4723 @cindex SquashFS, build an image with guix pack
4724 Yet another option is to produce a SquashFS image with the following
4728 guix pack -f squashfs guile emacs geiser
4732 The result is a SquashFS file system image that can either be mounted or
4733 directly be used as a file system container image with the
4734 @uref{http://singularity.lbl.gov, Singularity container execution
4735 environment}, using commands like @command{singularity shell} or
4736 @command{singularity exec}.
4738 Several command-line options allow you to customize your pack:
4741 @item --format=@var{format}
4742 @itemx -f @var{format}
4743 Produce a pack in the given @var{format}.
4745 The available formats are:
4749 This is the default format. It produces a tarball containing all the
4750 specified binaries and symlinks.
4753 This produces a tarball that follows the
4754 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
4755 Docker Image Specification}.
4758 This produces a SquashFS image containing all the specified binaries and
4759 symlinks, as well as empty mount points for virtual file systems like
4763 @cindex relocatable binaries
4766 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
4767 anywhere in the file system hierarchy and run from there.
4769 When this option is passed once, the resulting binaries require support for
4770 @dfn{user namespaces} in the kernel Linux; when passed
4771 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
4772 PRoot support, can be thought of as the abbreviation of ``Really
4773 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
4774 if user namespaces are unavailable, and essentially work anywhere---see below
4775 for the implications.
4777 For example, if you create a pack containing Bash with:
4780 guix pack -RR -S /mybin=bin bash
4784 ...@: you can copy that pack to a machine that lacks Guix, and from your
4785 home directory as a normal user, run:
4793 In that shell, if you type @code{ls /gnu/store}, you'll notice that
4794 @file{/gnu/store} shows up and contains all the dependencies of
4795 @code{bash}, even though the machine actually lacks @file{/gnu/store}
4796 altogether! That is probably the simplest way to deploy Guix-built
4797 software on a non-Guix machine.
4800 By default, relocatable binaries rely on the @dfn{user namespace} feature of
4801 the kernel Linux, which allows unprivileged users to mount or change root.
4802 Old versions of Linux did not support it, and some GNU/Linux distributions
4805 To produce relocatable binaries that work even in the absence of user
4806 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
4807 case, binaries will try user namespace support and fall back to PRoot if user
4808 namespaces are not supported.
4810 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
4811 support for file system virtualization. It achieves that by using the
4812 @code{ptrace} system call on the running program. This approach has the
4813 advantage to work without requiring special kernel support, but it incurs
4814 run-time overhead every time a system call is made.
4817 @item --expression=@var{expr}
4818 @itemx -e @var{expr}
4819 Consider the package @var{expr} evaluates to.
4821 This has the same purpose as the same-named option in @command{guix
4822 build} (@pxref{Additional Build Options, @code{--expression} in
4823 @command{guix build}}).
4825 @item --manifest=@var{file}
4826 @itemx -m @var{file}
4827 Use the packages contained in the manifest object returned by the Scheme
4830 This has a similar purpose as the same-named option in @command{guix
4831 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
4832 same manifest files. It allows you to define a collection of packages
4833 once and use it both for creating profiles and for creating archives
4834 for use on machines that do not have Guix installed. Note that you can
4835 specify @emph{either} a manifest file @emph{or} a list of packages,
4838 @item --system=@var{system}
4839 @itemx -s @var{system}
4840 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4841 the system type of the build host.
4843 @item --target=@var{triplet}
4844 @cindex cross-compilation
4845 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
4846 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
4847 configuration triplets,, autoconf, Autoconf}).
4849 @item --compression=@var{tool}
4850 @itemx -C @var{tool}
4851 Compress the resulting tarball using @var{tool}---one of @code{gzip},
4852 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
4854 @item --symlink=@var{spec}
4855 @itemx -S @var{spec}
4856 Add the symlinks specified by @var{spec} to the pack. This option can
4857 appear several times.
4859 @var{spec} has the form @code{@var{source}=@var{target}}, where
4860 @var{source} is the symlink that will be created and @var{target} is the
4863 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
4864 symlink pointing to the @file{bin} sub-directory of the profile.
4866 @item --save-provenance
4867 Save provenance information for the packages passed on the command line.
4868 Provenance information includes the URL and commit of the channels in use
4871 Provenance information is saved in the
4872 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
4873 usual package metadata---the name and version of each package, their
4874 propagated inputs, and so on. It is useful information to the recipient of
4875 the pack, who then knows how the pack was (supposedly) obtained.
4877 This option is not enabled by default because, like timestamps, provenance
4878 information contributes nothing to the build process. In other words, there
4879 is an infinity of channel URLs and commit IDs that can lead to the same pack.
4880 Recording such ``silent'' metadata in the output thus potentially breaks the
4881 source-to-binary bitwise reproducibility property.
4883 @item --localstatedir
4884 @itemx --profile-name=@var{name}
4885 Include the ``local state directory'', @file{/var/guix}, in the resulting
4886 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
4887 profile---by default @var{name} is @code{guix-profile}, which corresponds to
4888 @file{~root/.guix-profile}.
4890 @file{/var/guix} contains the store database (@pxref{The Store}) as well
4891 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
4892 the pack means that the store is ``complete'' and manageable by Guix;
4893 not providing it pack means that the store is ``dead'': items cannot be
4894 added to it or removed from it after extraction of the pack.
4896 One use case for this is the Guix self-contained binary tarball
4897 (@pxref{Binary Installation}).
4900 Use the bootstrap binaries to build the pack. This option is only
4901 useful to Guix developers.
4904 In addition, @command{guix pack} supports all the common build options
4905 (@pxref{Common Build Options}) and all the package transformation
4906 options (@pxref{Package Transformation Options}).
4909 @c *********************************************************************
4910 @node Programming Interface
4911 @chapter Programming Interface
4913 GNU Guix provides several Scheme programming interfaces (APIs) to
4914 define, build, and query packages. The first interface allows users to
4915 write high-level package definitions. These definitions refer to
4916 familiar packaging concepts, such as the name and version of a package,
4917 its build system, and its dependencies. These definitions can then be
4918 turned into concrete build actions.
4920 Build actions are performed by the Guix daemon, on behalf of users. In a
4921 standard setup, the daemon has write access to the store---the
4922 @file{/gnu/store} directory---whereas users do not. The recommended
4923 setup also has the daemon perform builds in chroots, under a specific
4924 build users, to minimize interference with the rest of the system.
4927 Lower-level APIs are available to interact with the daemon and the
4928 store. To instruct the daemon to perform a build action, users actually
4929 provide it with a @dfn{derivation}. A derivation is a low-level
4930 representation of the build actions to be taken, and the environment in
4931 which they should occur---derivations are to package definitions what
4932 assembly is to C programs. The term ``derivation'' comes from the fact
4933 that build results @emph{derive} from them.
4935 This chapter describes all these APIs in turn, starting from high-level
4936 package definitions.
4939 * Package Modules:: Packages from the programmer's viewpoint.
4940 * Defining Packages:: Defining new packages.
4941 * Build Systems:: Specifying how packages are built.
4942 * The Store:: Manipulating the package store.
4943 * Derivations:: Low-level interface to package derivations.
4944 * The Store Monad:: Purely functional interface to the store.
4945 * G-Expressions:: Manipulating build expressions.
4946 * Invoking guix repl:: Fiddling with Guix interactively.
4949 @node Package Modules
4950 @section Package Modules
4952 From a programming viewpoint, the package definitions of the
4953 GNU distribution are provided by Guile modules in the @code{(gnu packages
4954 @dots{})} name space@footnote{Note that packages under the @code{(gnu
4955 packages @dots{})} module name space are not necessarily ``GNU
4956 packages''. This module naming scheme follows the usual Guile module
4957 naming convention: @code{gnu} means that these modules are distributed
4958 as part of the GNU system, and @code{packages} identifies modules that
4959 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
4960 Reference Manual}). For instance, the @code{(gnu packages emacs)}
4961 module exports a variable named @code{emacs}, which is bound to a
4962 @code{<package>} object (@pxref{Defining Packages}).
4964 The @code{(gnu packages @dots{})} module name space is
4965 automatically scanned for packages by the command-line tools. For
4966 instance, when running @code{guix package -i emacs}, all the @code{(gnu
4967 packages @dots{})} modules are scanned until one that exports a package
4968 object whose name is @code{emacs} is found. This package search
4969 facility is implemented in the @code{(gnu packages)} module.
4971 @cindex customization, of packages
4972 @cindex package module search path
4973 Users can store package definitions in modules with different
4974 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
4975 name and module name must match. For instance, the @code{(my-packages
4976 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
4977 relative to the load path specified with @option{--load-path} or
4978 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
4979 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
4980 these package definitions visible to the user interfaces:
4984 By adding the directory containing your package modules to the search path
4985 with the @code{-L} flag of @command{guix package} and other commands
4986 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
4987 environment variable described below.
4990 By defining a @dfn{channel} and configuring @command{guix pull} so that it
4991 pulls from it. A channel is essentially a Git repository containing package
4992 modules. @xref{Channels}, for more information on how to define and use
4996 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
4998 @defvr {Environment Variable} GUIX_PACKAGE_PATH
4999 This is a colon-separated list of directories to search for additional
5000 package modules. Directories listed in this variable take precedence
5001 over the own modules of the distribution.
5004 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5005 each package is built based solely on other packages in the
5006 distribution. The root of this dependency graph is a small set of
5007 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5008 bootstrap)} module. For more information on bootstrapping,
5009 @pxref{Bootstrapping}.
5011 @node Defining Packages
5012 @section Defining Packages
5014 The high-level interface to package definitions is implemented in the
5015 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5016 example, the package definition, or @dfn{recipe}, for the GNU Hello
5017 package looks like this:
5020 (define-module (gnu packages hello)
5021 #:use-module (guix packages)
5022 #:use-module (guix download)
5023 #:use-module (guix build-system gnu)
5024 #:use-module (guix licenses)
5025 #:use-module (gnu packages gawk))
5027 (define-public hello
5033 (uri (string-append "mirror://gnu/hello/hello-" version
5037 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5038 (build-system gnu-build-system)
5039 (arguments '(#:configure-flags '("--enable-silent-rules")))
5040 (inputs `(("gawk" ,gawk)))
5041 (synopsis "Hello, GNU world: An example GNU package")
5042 (description "Guess what GNU Hello prints!")
5043 (home-page "http://www.gnu.org/software/hello/")
5048 Without being a Scheme expert, the reader may have guessed the meaning
5049 of the various fields here. This expression binds the variable
5050 @code{hello} to a @code{<package>} object, which is essentially a record
5051 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5052 This package object can be inspected using procedures found in the
5053 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5054 returns---surprise!---@code{"hello"}.
5056 With luck, you may be able to import part or all of the definition of
5057 the package you are interested in from another repository, using the
5058 @code{guix import} command (@pxref{Invoking guix import}).
5060 In the example above, @var{hello} is defined in a module of its own,
5061 @code{(gnu packages hello)}. Technically, this is not strictly
5062 necessary, but it is convenient to do so: all the packages defined in
5063 modules under @code{(gnu packages @dots{})} are automatically known to
5064 the command-line tools (@pxref{Package Modules}).
5066 There are a few points worth noting in the above package definition:
5070 The @code{source} field of the package is an @code{<origin>} object
5071 (@pxref{origin Reference}, for the complete reference).
5072 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5073 meaning that the source is a file to be downloaded over FTP or HTTP.
5075 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5076 the GNU mirrors defined in @code{(guix download)}.
5078 The @code{sha256} field specifies the expected SHA256 hash of the file
5079 being downloaded. It is mandatory, and allows Guix to check the
5080 integrity of the file. The @code{(base32 @dots{})} form introduces the
5081 base32 representation of the hash. You can obtain this information with
5082 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5083 hash} (@pxref{Invoking guix hash}).
5086 When needed, the @code{origin} form can also have a @code{patches} field
5087 listing patches to be applied, and a @code{snippet} field giving a
5088 Scheme expression to modify the source code.
5091 @cindex GNU Build System
5092 The @code{build-system} field specifies the procedure to build the
5093 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5094 represents the familiar GNU Build System, where packages may be
5095 configured, built, and installed with the usual @code{./configure &&
5096 make && make check && make install} command sequence.
5099 The @code{arguments} field specifies options for the build system
5100 (@pxref{Build Systems}). Here it is interpreted by
5101 @var{gnu-build-system} as a request run @file{configure} with the
5102 @code{--enable-silent-rules} flag.
5108 What about these quote (@code{'}) characters? They are Scheme syntax to
5109 introduce a literal list; @code{'} is synonymous with @code{quote}.
5110 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5111 for details. Here the value of the @code{arguments} field is a list of
5112 arguments passed to the build system down the road, as with @code{apply}
5113 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5116 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5117 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5118 @code{#:configure-flags} is a keyword used to pass a keyword argument
5119 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5123 The @code{inputs} field specifies inputs to the build process---i.e.,
5124 build-time or run-time dependencies of the package. Here, we define an
5125 input called @code{"gawk"} whose value is that of the @var{gawk}
5126 variable; @var{gawk} is itself bound to a @code{<package>} object.
5128 @cindex backquote (quasiquote)
5131 @cindex comma (unquote)
5135 @findex unquote-splicing
5136 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5137 us to introduce a literal list in the @code{inputs} field, while
5138 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5139 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5142 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5143 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5144 of ensuring that they are present (@pxref{Build Systems}).
5146 However, any other dependencies need to be specified in the
5147 @code{inputs} field. Any dependency not specified here will simply be
5148 unavailable to the build process, possibly leading to a build failure.
5151 @xref{package Reference}, for a full description of possible fields.
5153 Once a package definition is in place, the
5154 package may actually be built using the @code{guix build} command-line
5155 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5156 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5157 package definition using the @command{guix edit} command
5158 (@pxref{Invoking guix edit}).
5159 @xref{Packaging Guidelines}, for
5160 more information on how to test package definitions, and
5161 @ref{Invoking guix lint}, for information on how to check a definition
5162 for style conformance.
5163 @vindex GUIX_PACKAGE_PATH
5164 Lastly, @pxref{Channels}, for information
5165 on how to extend the distribution by adding your own package definitions
5168 Finally, updating the package definition to a new upstream version
5169 can be partly automated by the @command{guix refresh} command
5170 (@pxref{Invoking guix refresh}).
5172 Behind the scenes, a derivation corresponding to the @code{<package>}
5173 object is first computed by the @code{package-derivation} procedure.
5174 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
5175 The build actions it prescribes may then be realized by using the
5176 @code{build-derivations} procedure (@pxref{The Store}).
5178 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5179 Return the @code{<derivation>} object of @var{package} for @var{system}
5180 (@pxref{Derivations}).
5182 @var{package} must be a valid @code{<package>} object, and @var{system}
5183 must be a string denoting the target system type---e.g.,
5184 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5185 must be a connection to the daemon, which operates on the store
5186 (@pxref{The Store}).
5190 @cindex cross-compilation
5191 Similarly, it is possible to compute a derivation that cross-builds a
5192 package for some other system:
5194 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5195 @var{package} @var{target} [@var{system}]
5196 Return the @code{<derivation>} object of @var{package} cross-built from
5197 @var{system} to @var{target}.
5199 @var{target} must be a valid GNU triplet denoting the target hardware
5200 and operating system, such as @code{"mips64el-linux-gnu"}
5201 (@pxref{Configuration Names, GNU configuration triplets,, configure, GNU
5202 Configure and Build System}).
5205 @cindex package transformations
5206 @cindex input rewriting
5207 @cindex dependency tree rewriting
5208 Packages can be manipulated in arbitrary ways. An example of a useful
5209 transformation is @dfn{input rewriting}, whereby the dependency tree of
5210 a package is rewritten by replacing specific inputs by others:
5212 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5213 [@var{rewrite-name}]
5214 Return a procedure that, when passed a package, replaces its direct and
5215 indirect dependencies (but not its implicit inputs) according to
5216 @var{replacements}. @var{replacements} is a list of package pairs; the
5217 first element of each pair is the package to replace, and the second one
5220 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5221 the name of a package and returns its new name after rewrite.
5225 Consider this example:
5228 (define libressl-instead-of-openssl
5229 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5231 (package-input-rewriting `((,openssl . ,libressl))))
5233 (define git-with-libressl
5234 (libressl-instead-of-openssl git))
5238 Here we first define a rewriting procedure that replaces @var{openssl}
5239 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5240 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5241 This is exactly what the @option{--with-input} command-line option does
5242 (@pxref{Package Transformation Options, @option{--with-input}}).
5244 The following variant of @code{package-input-rewriting} can match packages to
5245 be replaced by name rather than by identity.
5247 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5248 Return a procedure that, given a package, applies the given @var{replacements} to
5249 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5250 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5251 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5252 replacement for that package.
5255 The example above could be rewritten this way:
5258 (define libressl-instead-of-openssl
5259 ;; Replace all the packages called "openssl" with LibreSSL.
5260 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5263 The key difference here is that, this time, packages are matched by spec and
5264 not by identity. In other words, any package in the graph that is called
5265 @code{openssl} will be replaced.
5267 A more generic procedure to rewrite a package dependency graph is
5268 @code{package-mapping}: it supports arbitrary changes to nodes in the
5271 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5272 Return a procedure that, given a package, applies @var{proc} to all the packages
5273 depended on and returns the resulting package. The procedure stops recursion
5274 when @var{cut?} returns true for a given package.
5278 * package Reference:: The package data type.
5279 * origin Reference:: The origin data type.
5283 @node package Reference
5284 @subsection @code{package} Reference
5286 This section summarizes all the options available in @code{package}
5287 declarations (@pxref{Defining Packages}).
5289 @deftp {Data Type} package
5290 This is the data type representing a package recipe.
5294 The name of the package, as a string.
5296 @item @code{version}
5297 The version of the package, as a string.
5300 An object telling how the source code for the package should be
5301 acquired. Most of the time, this is an @code{origin} object, which
5302 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5303 can also be any other ``file-like'' object such as a @code{local-file},
5304 which denotes a file from the local file system (@pxref{G-Expressions,
5305 @code{local-file}}).
5307 @item @code{build-system}
5308 The build system that should be used to build the package (@pxref{Build
5311 @item @code{arguments} (default: @code{'()})
5312 The arguments that should be passed to the build system. This is a
5313 list, typically containing sequential keyword-value pairs.
5315 @item @code{inputs} (default: @code{'()})
5316 @itemx @code{native-inputs} (default: @code{'()})
5317 @itemx @code{propagated-inputs} (default: @code{'()})
5318 @cindex inputs, of packages
5319 These fields list dependencies of the package. Each one is a list of
5320 tuples, where each tuple has a label for the input (a string) as its
5321 first element, a package, origin, or derivation as its second element,
5322 and optionally the name of the output thereof that should be used, which
5323 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5324 more on package outputs). For example, the list below specifies three
5328 `(("libffi" ,libffi)
5329 ("libunistring" ,libunistring)
5330 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5333 @cindex cross compilation, package dependencies
5334 The distinction between @code{native-inputs} and @code{inputs} is
5335 necessary when considering cross-compilation. When cross-compiling,
5336 dependencies listed in @code{inputs} are built for the @emph{target}
5337 architecture; conversely, dependencies listed in @code{native-inputs}
5338 are built for the architecture of the @emph{build} machine.
5340 @code{native-inputs} is typically used to list tools needed at
5341 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5342 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5343 this area (@pxref{Invoking guix lint}).
5345 @anchor{package-propagated-inputs}
5346 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5347 specified packages will be automatically installed alongside the package
5348 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5349 package}}, for information on how @command{guix package} deals with
5352 For example this is necessary when a C/C++ library needs headers of
5353 another library to compile, or when a pkg-config file refers to another
5354 one @i{via} its @code{Requires} field.
5356 Another example where @code{propagated-inputs} is useful is for languages
5357 that lack a facility to record the run-time search path akin to the
5358 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5359 more. To ensure that libraries written in those languages can find
5360 library code they depend on at run time, run-time dependencies must be
5361 listed in @code{propagated-inputs} rather than @code{inputs}.
5363 @item @code{self-native-input?} (default: @code{#f})
5364 This is a Boolean field telling whether the package should use itself as
5365 a native input when cross-compiling.
5367 @item @code{outputs} (default: @code{'("out")})
5368 The list of output names of the package. @xref{Packages with Multiple
5369 Outputs}, for typical uses of additional outputs.
5371 @item @code{native-search-paths} (default: @code{'()})
5372 @itemx @code{search-paths} (default: @code{'()})
5373 A list of @code{search-path-specification} objects describing
5374 search-path environment variables honored by the package.
5376 @item @code{replacement} (default: @code{#f})
5377 This must be either @code{#f} or a package object that will be used as a
5378 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5381 @item @code{synopsis}
5382 A one-line description of the package.
5384 @item @code{description}
5385 A more elaborate description of the package.
5387 @item @code{license}
5388 @cindex license, of packages
5389 The license of the package; a value from @code{(guix licenses)},
5390 or a list of such values.
5392 @item @code{home-page}
5393 The URL to the home-page of the package, as a string.
5395 @item @code{supported-systems} (default: @var{%supported-systems})
5396 The list of systems supported by the package, as strings of the form
5397 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5399 @item @code{maintainers} (default: @code{'()})
5400 The list of maintainers of the package, as @code{maintainer} objects.
5402 @item @code{location} (default: source location of the @code{package} form)
5403 The source location of the package. It is useful to override this when
5404 inheriting from another package, in which case this field is not
5405 automatically corrected.
5410 @node origin Reference
5411 @subsection @code{origin} Reference
5413 This section summarizes all the options available in @code{origin}
5414 declarations (@pxref{Defining Packages}).
5416 @deftp {Data Type} origin
5417 This is the data type representing a source code origin.
5421 An object containing the URI of the source. The object type depends on
5422 the @code{method} (see below). For example, when using the
5423 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5424 values are: a URL represented as a string, or a list thereof.
5427 A procedure that handles the URI.
5432 @item @var{url-fetch} from @code{(guix download)}
5433 download a file from the HTTP, HTTPS, or FTP URL specified in the
5437 @item @var{git-fetch} from @code{(guix git-download)}
5438 clone the Git version control repository, and check out the revision
5439 specified in the @code{uri} field as a @code{git-reference} object; a
5440 @code{git-reference} looks like this:
5444 (url "git://git.debian.org/git/pkg-shadow/shadow")
5445 (commit "v4.1.5.1"))
5450 A bytevector containing the SHA-256 hash of the source. Typically the
5451 @code{base32} form is used here to generate the bytevector from a
5454 You can obtain this information using @code{guix download}
5455 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5458 @item @code{file-name} (default: @code{#f})
5459 The file name under which the source code should be saved. When this is
5460 @code{#f}, a sensible default value will be used in most cases. In case
5461 the source is fetched from a URL, the file name from the URL will be
5462 used. For version control checkouts, it is recommended to provide the
5463 file name explicitly because the default is not very descriptive.
5465 @item @code{patches} (default: @code{'()})
5466 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5467 file-like objects}) pointing to patches to be applied to the source.
5469 This list of patches must be unconditional. In particular, it cannot
5470 depend on the value of @code{%current-system} or
5471 @code{%current-target-system}.
5473 @item @code{snippet} (default: @code{#f})
5474 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5475 in the source directory. This is a convenient way to modify the source,
5476 sometimes more convenient than a patch.
5478 @item @code{patch-flags} (default: @code{'("-p1")})
5479 A list of command-line flags that should be passed to the @code{patch}
5482 @item @code{patch-inputs} (default: @code{#f})
5483 Input packages or derivations to the patching process. When this is
5484 @code{#f}, the usual set of inputs necessary for patching are provided,
5485 such as GNU@tie{}Patch.
5487 @item @code{modules} (default: @code{'()})
5488 A list of Guile modules that should be loaded during the patching
5489 process and while running the code in the @code{snippet} field.
5491 @item @code{patch-guile} (default: @code{#f})
5492 The Guile package that should be used in the patching process. When
5493 this is @code{#f}, a sensible default is used.
5499 @section Build Systems
5501 @cindex build system
5502 Each package definition specifies a @dfn{build system} and arguments for
5503 that build system (@pxref{Defining Packages}). This @code{build-system}
5504 field represents the build procedure of the package, as well as implicit
5505 dependencies of that build procedure.
5507 Build systems are @code{<build-system>} objects. The interface to
5508 create and manipulate them is provided by the @code{(guix build-system)}
5509 module, and actual build systems are exported by specific modules.
5511 @cindex bag (low-level package representation)
5512 Under the hood, build systems first compile package objects to
5513 @dfn{bags}. A @dfn{bag} is like a package, but with less
5514 ornamentation---in other words, a bag is a lower-level representation of
5515 a package, which includes all the inputs of that package, including some
5516 that were implicitly added by the build system. This intermediate
5517 representation is then compiled to a derivation (@pxref{Derivations}).
5519 Build systems accept an optional list of @dfn{arguments}. In package
5520 definitions, these are passed @i{via} the @code{arguments} field
5521 (@pxref{Defining Packages}). They are typically keyword arguments
5522 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
5523 Guile Reference Manual}). The value of these arguments is usually
5524 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
5525 by the daemon (@pxref{Derivations}).
5527 The main build system is @var{gnu-build-system}, which implements the
5528 standard build procedure for GNU and many other packages. It
5529 is provided by the @code{(guix build-system gnu)} module.
5531 @defvr {Scheme Variable} gnu-build-system
5532 @var{gnu-build-system} represents the GNU Build System, and variants
5533 thereof (@pxref{Configuration, configuration and makefile conventions,,
5534 standards, GNU Coding Standards}).
5536 @cindex build phases
5537 In a nutshell, packages using it are configured, built, and installed with
5538 the usual @code{./configure && make && make check && make install}
5539 command sequence. In practice, a few additional steps are often needed.
5540 All these steps are split up in separate @dfn{phases},
5541 notably@footnote{Please see the @code{(guix build gnu-build-system)}
5542 modules for more details about the build phases.}:
5546 Unpack the source tarball, and change the current directory to the
5547 extracted source tree. If the source is actually a directory, copy it
5548 to the build tree, and enter that directory.
5550 @item patch-source-shebangs
5551 Patch shebangs encountered in source files so they refer to the right
5552 store file names. For instance, this changes @code{#!/bin/sh} to
5553 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
5556 Run the @file{configure} script with a number of default options, such
5557 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
5558 by the @code{#:configure-flags} argument.
5561 Run @code{make} with the list of flags specified with
5562 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
5563 (the default), build with @code{make -j}.
5566 Run @code{make check}, or some other target specified with
5567 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
5568 @code{#:parallel-tests?} argument is true (the default), run @code{make
5572 Run @code{make install} with the flags listed in @code{#:make-flags}.
5574 @item patch-shebangs
5575 Patch shebangs on the installed executable files.
5578 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
5579 is false), copying them to the @code{debug} output when available
5580 (@pxref{Installing Debugging Files}).
5583 @vindex %standard-phases
5584 The build-side module @code{(guix build gnu-build-system)} defines
5585 @var{%standard-phases} as the default list of build phases.
5586 @var{%standard-phases} is a list of symbol/procedure pairs, where the
5587 procedure implements the actual phase.
5589 The list of phases used for a particular package can be changed with the
5590 @code{#:phases} parameter. For instance, passing:
5593 #:phases (modify-phases %standard-phases (delete 'configure))
5596 means that all the phases described above will be used, except the
5597 @code{configure} phase.
5599 In addition, this build system ensures that the ``standard'' environment
5600 for GNU packages is available. This includes tools such as GCC, libc,
5601 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
5602 build-system gnu)} module for a complete list). We call these the
5603 @dfn{implicit inputs} of a package, because package definitions do not
5604 have to mention them.
5607 Other @code{<build-system>} objects are defined to support other
5608 conventions and tools used by free software packages. They inherit most
5609 of @var{gnu-build-system}, and differ mainly in the set of inputs
5610 implicitly added to the build process, and in the list of phases
5611 executed. Some of these build systems are listed below.
5613 @defvr {Scheme Variable} ant-build-system
5614 This variable is exported by @code{(guix build-system ant)}. It
5615 implements the build procedure for Java packages that can be built with
5616 @url{http://ant.apache.org/, Ant build tool}.
5618 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
5619 provided by the @code{icedtea} package to the set of inputs. Different
5620 packages can be specified with the @code{#:ant} and @code{#:jdk}
5621 parameters, respectively.
5623 When the original package does not provide a suitable Ant build file,
5624 the parameter @code{#:jar-name} can be used to generate a minimal Ant
5625 build file @file{build.xml} with tasks to build the specified jar
5626 archive. In this case the parameter @code{#:source-dir} can be used to
5627 specify the source sub-directory, defaulting to ``src''.
5629 The @code{#:main-class} parameter can be used with the minimal ant
5630 buildfile to specify the main class of the resulting jar. This makes the
5631 jar file executable. The @code{#:test-include} parameter can be used to
5632 specify the list of junit tests to run. It defaults to
5633 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
5634 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
5635 because abstract classes cannot be run as tests.
5637 The parameter @code{#:build-target} can be used to specify the Ant task
5638 that should be run during the @code{build} phase. By default the
5639 ``jar'' task will be run.
5643 @defvr {Scheme Variable} android-ndk-build-system
5644 @cindex Android distribution
5645 @cindex Android NDK build system
5646 This variable is exported by @code{(guix build-system android-ndk)}. It
5647 implements a build procedure for Android NDK (native development kit)
5648 packages using a Guix-specific build process.
5650 The build system assumes that packages install their public interface
5651 (header) files to the subdirectory "include" of the "out" output and
5652 their libraries to the subdirectory "lib" of the "out" output.
5654 It's also assumed that the union of all the dependencies of a package
5655 has no conflicting files.
5657 For the time being, cross-compilation is not supported - so right now
5658 the libraries and header files are assumed to be host tools.
5662 @defvr {Scheme Variable} asdf-build-system/source
5663 @defvrx {Scheme Variable} asdf-build-system/sbcl
5664 @defvrx {Scheme Variable} asdf-build-system/ecl
5666 These variables, exported by @code{(guix build-system asdf)}, implement
5667 build procedures for Common Lisp packages using
5668 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
5669 definition facility for Common Lisp programs and libraries.
5671 The @code{asdf-build-system/source} system installs the packages in
5672 source form, and can be loaded using any common lisp implementation, via
5673 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
5674 systems in the format which a particular implementation understands.
5675 These build systems can also be used to produce executable programs, or
5676 lisp images which contain a set of packages pre-loaded.
5678 The build system uses naming conventions. For binary packages, the
5679 package name should be prefixed with the lisp implementation, such as
5680 @code{sbcl-} for @code{asdf-build-system/sbcl}.
5682 Additionally, the corresponding source package should be labeled using
5683 the same convention as python packages (see @ref{Python Modules}), using
5684 the @code{cl-} prefix.
5686 For binary packages, each system should be defined as a Guix package.
5687 If one package @code{origin} contains several systems, package variants
5688 can be created in order to build all the systems. Source packages,
5689 which use @code{asdf-build-system/source}, may contain several systems.
5691 In order to create executable programs and images, the build-side
5692 procedures @code{build-program} and @code{build-image} can be used.
5693 They should be called in a build phase after the @code{create-symlinks}
5694 phase, so that the system which was just built can be used within the
5695 resulting image. @code{build-program} requires a list of Common Lisp
5696 expressions to be passed as the @code{#:entry-program} argument.
5698 If the system is not defined within its own @code{.asd} file of the same
5699 name, then the @code{#:asd-file} parameter should be used to specify
5700 which file the system is defined in. Furthermore, if the package
5701 defines a system for its tests in a separate file, it will be loaded
5702 before the tests are run if it is specified by the
5703 @code{#:test-asd-file} parameter. If it is not set, the files
5704 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
5705 and @code{test.asd} will be tried if they exist.
5707 If for some reason the package must be named in a different way than the
5708 naming conventions suggest, the @code{#:asd-system-name} parameter can
5709 be used to specify the name of the system.
5713 @defvr {Scheme Variable} cargo-build-system
5714 @cindex Rust programming language
5715 @cindex Cargo (Rust build system)
5716 This variable is exported by @code{(guix build-system cargo)}. It
5717 supports builds of packages using Cargo, the build tool of the
5718 @uref{https://www.rust-lang.org, Rust programming language}.
5720 In its @code{configure} phase, this build system replaces dependencies
5721 specified in the @file{Carto.toml} file with inputs to the Guix package.
5722 The @code{install} phase installs the binaries, and it also installs the
5723 source code and @file{Cargo.toml} file.
5726 @cindex Clojure (programming language)
5727 @cindex simple Clojure build system
5728 @defvr {Scheme Variable} clojure-build-system
5729 This variable is exported by @code{(guix build-system clojure)}. It implements
5730 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
5731 using plain old @code{compile} in Clojure. Cross-compilation is not supported
5734 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
5735 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
5736 @code{#:zip} parameters, respectively.
5738 A list of source directories, test directories and jar names can be specified
5739 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
5740 parameters, respectively. Compile directory and main class can be specified
5741 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
5742 Other parameters are documented below.
5744 This build system is an extension of @var{ant-build-system}, but with the
5745 following phases changed:
5750 This phase calls @code{compile} in Clojure to compile source files and runs
5751 @command{jar} to create jars from both source files and compiled files
5752 according to the include list and exclude list specified in
5753 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
5754 has priority over the include list. These lists consist of symbols
5755 representing Clojure libraries or the special keyword @code{#:all} representing
5756 all Clojure libraries found under the source directories. The parameter
5757 @code{#:omit-source?} decides if source should be included into the jars.
5760 This phase runs tests according to the include list and exclude list specified
5761 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
5762 meanings are analogous to that of @code{#:aot-include} and
5763 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
5764 stands for all Clojure libraries found under the test directories. The
5765 parameter @code{#:tests?} decides if tests should be run.
5768 This phase installs all jars built previously.
5771 Apart from the above, this build system also contains an additional phase:
5776 This phase installs all top-level files with base name matching
5777 @var{%doc-regex}. A different regex can be specified with the
5778 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
5779 directories specified in @code{#:doc-dirs} are installed as well.
5783 @defvr {Scheme Variable} cmake-build-system
5784 This variable is exported by @code{(guix build-system cmake)}. It
5785 implements the build procedure for packages using the
5786 @url{http://www.cmake.org, CMake build tool}.
5788 It automatically adds the @code{cmake} package to the set of inputs.
5789 Which package is used can be specified with the @code{#:cmake}
5792 The @code{#:configure-flags} parameter is taken as a list of flags
5793 passed to the @command{cmake} command. The @code{#:build-type}
5794 parameter specifies in abstract terms the flags passed to the compiler;
5795 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
5796 debugging information''), which roughly means that code is compiled with
5797 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
5800 @defvr {Scheme Variable} dune-build-system
5801 This variable is exported by @code{(guix build-system dune)}. It
5802 supports builds of packages using @uref{https://dune.build/, Dune}, a build
5803 tool for the OCaml programming language. It is implemented as an extension
5804 of the @code{ocaml-build-system} which is described below. As such, the
5805 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
5808 It automatically adds the @code{dune} package to the set of inputs.
5809 Which package is used can be specified with the @code{#:dune}
5812 There is no @code{configure} phase because dune packages typically don't
5813 need to be configured. The @code{#:build-flags} parameter is taken as a
5814 list of flags passed to the @code{dune} command during the build.
5816 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
5817 command instead of the more recent @code{dune} command while building
5818 a package. Its default value is @code{#f}.
5821 @defvr {Scheme Variable} go-build-system
5822 This variable is exported by @code{(guix build-system go)}. It
5823 implements a build procedure for Go packages using the standard
5824 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
5825 Go build mechanisms}.
5827 The user is expected to provide a value for the key @code{#:import-path}
5828 and, in some cases, @code{#:unpack-path}. The
5829 @url{https://golang.org/doc/code.html#ImportPaths, import path}
5830 corresponds to the file system path expected by the package's build
5831 scripts and any referring packages, and provides a unique way to
5832 refer to a Go package. It is typically based on a combination of the
5833 package source code's remote URI and file system hierarchy structure. In
5834 some cases, you will need to unpack the package's source code to a
5835 different directory structure than the one indicated by the import path,
5836 and @code{#:unpack-path} should be used in such cases.
5838 Packages that provide Go libraries should install their source code into
5839 the built output. The key @code{#:install-source?}, which defaults to
5840 @code{#t}, controls whether or not the source code is installed. It can
5841 be set to @code{#f} for packages that only provide executable files.
5844 @defvr {Scheme Variable} glib-or-gtk-build-system
5845 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
5846 is intended for use with packages making use of GLib or GTK+.
5848 This build system adds the following two phases to the ones defined by
5849 @var{gnu-build-system}:
5852 @item glib-or-gtk-wrap
5853 The phase @code{glib-or-gtk-wrap} ensures that programs in
5854 @file{bin/} are able to find GLib ``schemas'' and
5855 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
5856 modules}. This is achieved by wrapping the programs in launch scripts
5857 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
5858 environment variables.
5860 It is possible to exclude specific package outputs from that wrapping
5861 process by listing their names in the
5862 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
5863 when an output is known not to contain any GLib or GTK+ binaries, and
5864 where wrapping would gratuitously add a dependency of that output on
5867 @item glib-or-gtk-compile-schemas
5868 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
5869 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
5870 GSettings schemas} of GLib are compiled. Compilation is performed by the
5871 @command{glib-compile-schemas} program. It is provided by the package
5872 @code{glib:bin} which is automatically imported by the build system.
5873 The @code{glib} package providing @command{glib-compile-schemas} can be
5874 specified with the @code{#:glib} parameter.
5877 Both phases are executed after the @code{install} phase.
5880 @defvr {Scheme Variable} guile-build-system
5881 This build system is for Guile packages that consist exclusively of Scheme
5882 code and that are so lean that they don't even have a makefile, let alone a
5883 @file{configure} script. It compiles Scheme code using @command{guild
5884 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
5885 installs the @file{.scm} and @file{.go} files in the right place. It also
5886 installs documentation.
5888 This build system supports cross-compilation by using the @code{--target}
5889 option of @command{guild compile}.
5891 Packages built with @code{guile-build-system} must provide a Guile package in
5892 their @code{native-inputs} field.
5895 @defvr {Scheme Variable} minify-build-system
5896 This variable is exported by @code{(guix build-system minify)}. It
5897 implements a minification procedure for simple JavaScript packages.
5899 It adds @code{uglify-js} to the set of inputs and uses it to compress
5900 all JavaScript files in the @file{src} directory. A different minifier
5901 package can be specified with the @code{#:uglify-js} parameter, but it
5902 is expected that the package writes the minified code to the standard
5905 When the input JavaScript files are not all located in the @file{src}
5906 directory, the parameter @code{#:javascript-files} can be used to
5907 specify a list of file names to feed to the minifier.
5910 @defvr {Scheme Variable} ocaml-build-system
5911 This variable is exported by @code{(guix build-system ocaml)}. It implements
5912 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
5913 of choosing the correct set of commands to run for each package. OCaml
5914 packages can expect many different commands to be run. This build system will
5917 When the package has a @file{setup.ml} file present at the top-level, it will
5918 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
5919 @code{ocaml setup.ml -install}. The build system will assume that this file
5920 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
5921 care of setting the prefix and enabling tests if they are not disabled. You
5922 can pass configure and build flags with the @code{#:configure-flags} and
5923 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
5924 set of flags used to enable tests. The @code{#:use-make?} key can be used to
5925 bypass this system in the build and install phases.
5927 When the package has a @file{configure} file, it is assumed that it is a
5928 hand-made configure script that requires a different argument format than
5929 in the @code{gnu-build-system}. You can add more flags with the
5930 @code{#:configure-flags} key.
5932 When the package has a @file{Makefile} file (or @code{#:use-make?} is
5933 @code{#t}), it will be used and more flags can be passed to the build and
5934 install phases with the @code{#:make-flags} key.
5936 Finally, some packages do not have these files and use a somewhat standard
5937 location for its build system. In that case, the build system will run
5938 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
5939 providing the path to the required findlib module. Additional flags can
5940 be passed via the @code{#:build-flags} key. Install is taken care of by
5941 @command{opam-installer}. In this case, the @code{opam} package must
5942 be added to the @code{native-inputs} field of the package definition.
5944 Note that most OCaml packages assume they will be installed in the same
5945 directory as OCaml, which is not what we want in guix. In particular, they
5946 will install @file{.so} files in their module's directory, which is usually
5947 fine because it is in the OCaml compiler directory. In guix though, these
5948 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
5949 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
5950 @file{.so} libraries should be installed.
5953 @defvr {Scheme Variable} python-build-system
5954 This variable is exported by @code{(guix build-system python)}. It
5955 implements the more or less standard build procedure used by Python
5956 packages, which consists in running @code{python setup.py build} and
5957 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
5959 For packages that install stand-alone Python programs under @code{bin/},
5960 it takes care of wrapping these programs so that their @code{PYTHONPATH}
5961 environment variable points to all the Python libraries they depend on.
5963 Which Python package is used to perform the build can be specified with
5964 the @code{#:python} parameter. This is a useful way to force a package
5965 to be built for a specific version of the Python interpreter, which
5966 might be necessary if the package is only compatible with a single
5967 interpreter version.
5969 By default guix calls @code{setup.py} under control of
5970 @code{setuptools}, much like @command{pip} does. Some packages are not
5971 compatible with setuptools (and pip), thus you can disable this by
5972 setting the @code{#:use-setuptools} parameter to @code{#f}.
5975 @defvr {Scheme Variable} perl-build-system
5976 This variable is exported by @code{(guix build-system perl)}. It
5977 implements the standard build procedure for Perl packages, which either
5978 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
5979 followed by @code{Build} and @code{Build install}; or in running
5980 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
5981 @code{make} and @code{make install}, depending on which of
5982 @code{Build.PL} or @code{Makefile.PL} is present in the package
5983 distribution. Preference is given to the former if both @code{Build.PL}
5984 and @code{Makefile.PL} exist in the package distribution. This
5985 preference can be reversed by specifying @code{#t} for the
5986 @code{#:make-maker?} parameter.
5988 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
5989 passes flags specified by the @code{#:make-maker-flags} or
5990 @code{#:module-build-flags} parameter, respectively.
5992 Which Perl package is used can be specified with @code{#:perl}.
5995 @defvr {Scheme Variable} r-build-system
5996 This variable is exported by @code{(guix build-system r)}. It
5997 implements the build procedure used by @uref{http://r-project.org, R}
5998 packages, which essentially is little more than running @code{R CMD
5999 INSTALL --library=/gnu/store/@dots{}} in an environment where
6000 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6001 are run after installation using the R function
6002 @code{tools::testInstalledPackage}.
6005 @defvr {Scheme Variable} rakudo-build-system
6006 This variable is exported by @code{(guix build-system rakudo)} It
6007 implements the build procedure used by @uref{https://rakudo.org/,
6008 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6009 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6010 installs the binaries, library files and the resources, as well as wrap
6011 the files under the @code{bin/} directory. Tests can be skipped by
6012 passing @code{#f} to the @code{tests?} parameter.
6014 Which rakudo package is used can be specified with @code{rakudo}.
6015 Which perl6-tap-harness package used for the tests can be specified with
6016 @code{#:prove6} or removed by passing @code{#f} to the
6017 @code{with-prove6?} parameter.
6018 Which perl6-zef package used for tests and installing can be specified
6019 with @code{#:zef} or removed by passing @code{#f} to the
6020 @code{with-zef?} parameter.
6023 @defvr {Scheme Variable} texlive-build-system
6024 This variable is exported by @code{(guix build-system texlive)}. It is
6025 used to build TeX packages in batch mode with a specified engine. The
6026 build system sets the @code{TEXINPUTS} variable to find all TeX source
6027 files in the inputs.
6029 By default it runs @code{luatex} on all files ending on @code{ins}. A
6030 different engine and format can be specified with the
6031 @code{#:tex-format} argument. Different build targets can be specified
6032 with the @code{#:build-targets} argument, which expects a list of file
6033 names. The build system adds only @code{texlive-bin} and
6034 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6035 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6036 and @code{#:texlive-latex-base}, respectively.
6038 The @code{#:tex-directory} parameter tells the build system where to
6039 install the built files under the texmf tree.
6042 @defvr {Scheme Variable} ruby-build-system
6043 This variable is exported by @code{(guix build-system ruby)}. It
6044 implements the RubyGems build procedure used by Ruby packages, which
6045 involves running @code{gem build} followed by @code{gem install}.
6047 The @code{source} field of a package that uses this build system
6048 typically references a gem archive, since this is the format that Ruby
6049 developers use when releasing their software. The build system unpacks
6050 the gem archive, potentially patches the source, runs the test suite,
6051 repackages the gem, and installs it. Additionally, directories and
6052 tarballs may be referenced to allow building unreleased gems from Git or
6053 a traditional source release tarball.
6055 Which Ruby package is used can be specified with the @code{#:ruby}
6056 parameter. A list of additional flags to be passed to the @command{gem}
6057 command can be specified with the @code{#:gem-flags} parameter.
6060 @defvr {Scheme Variable} waf-build-system
6061 This variable is exported by @code{(guix build-system waf)}. It
6062 implements a build procedure around the @code{waf} script. The common
6063 phases---@code{configure}, @code{build}, and @code{install}---are
6064 implemented by passing their names as arguments to the @code{waf}
6067 The @code{waf} script is executed by the Python interpreter. Which
6068 Python package is used to run the script can be specified with the
6069 @code{#:python} parameter.
6072 @defvr {Scheme Variable} scons-build-system
6073 This variable is exported by @code{(guix build-system scons)}. It
6074 implements the build procedure used by the SCons software construction
6075 tool. This build system runs @code{scons} to build the package,
6076 @code{scons test} to run tests, and then @code{scons install} to install
6079 Additional flags to be passed to @code{scons} can be specified with the
6080 @code{#:scons-flags} parameter. The version of Python used to run SCons
6081 can be specified by selecting the appropriate SCons package with the
6082 @code{#:scons} parameter.
6085 @defvr {Scheme Variable} haskell-build-system
6086 This variable is exported by @code{(guix build-system haskell)}. It
6087 implements the Cabal build procedure used by Haskell packages, which
6088 involves running @code{runhaskell Setup.hs configure
6089 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6090 Instead of installing the package by running @code{runhaskell Setup.hs
6091 install}, to avoid trying to register libraries in the read-only
6092 compiler store directory, the build system uses @code{runhaskell
6093 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6094 addition, the build system generates the package documentation by
6095 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6096 is passed. Optional Haddock parameters can be passed with the help of
6097 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6098 not found, the build system looks for @code{Setup.lhs} instead.
6100 Which Haskell compiler is used can be specified with the @code{#:haskell}
6101 parameter which defaults to @code{ghc}.
6104 @defvr {Scheme Variable} dub-build-system
6105 This variable is exported by @code{(guix build-system dub)}. It
6106 implements the Dub build procedure used by D packages, which
6107 involves running @code{dub build} and @code{dub run}.
6108 Installation is done by copying the files manually.
6110 Which D compiler is used can be specified with the @code{#:ldc}
6111 parameter which defaults to @code{ldc}.
6114 @defvr {Scheme Variable} emacs-build-system
6115 This variable is exported by @code{(guix build-system emacs)}. It
6116 implements an installation procedure similar to the packaging system
6117 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6119 It first creates the @code{@var{package}-autoloads.el} file, then it
6120 byte compiles all Emacs Lisp files. Differently from the Emacs
6121 packaging system, the Info documentation files are moved to the standard
6122 documentation directory and the @file{dir} file is deleted. Each
6123 package is installed in its own directory under
6124 @file{share/emacs/site-lisp/guix.d}.
6127 @defvr {Scheme Variable} font-build-system
6128 This variable is exported by @code{(guix build-system font)}. It
6129 implements an installation procedure for font packages where upstream
6130 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6131 need to be copied into place. It copies font files to standard
6132 locations in the output directory.
6135 @defvr {Scheme Variable} meson-build-system
6136 This variable is exported by @code{(guix build-system meson)}. It
6137 implements the build procedure for packages that use
6138 @url{http://mesonbuild.com, Meson} as their build system.
6140 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6141 of inputs, and they can be changed with the parameters @code{#:meson}
6142 and @code{#:ninja} if needed. The default Meson is
6143 @code{meson-for-build}, which is special because it doesn't clear the
6144 @code{RUNPATH} of binaries and libraries when they are installed.
6146 This build system is an extension of @var{gnu-build-system}, but with the
6147 following phases changed to some specific for Meson:
6152 The phase runs @code{meson} with the flags specified in
6153 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6154 @code{plain} unless something else is specified in @code{#:build-type}.
6157 The phase runs @code{ninja} to build the package in parallel by default, but
6158 this can be changed with @code{#:parallel-build?}.
6161 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6162 which is @code{"test"} by default.
6165 The phase runs @code{ninja install} and can not be changed.
6168 Apart from that, the build system also adds the following phases:
6173 This phase ensures that all binaries can find the libraries they need.
6174 It searches for required libraries in subdirectories of the package being
6175 built, and adds those to @code{RUNPATH} where needed. It also removes
6176 references to libraries left over from the build phase by
6177 @code{meson-for-build}, such as test dependencies, that aren't actually
6178 required for the program to run.
6180 @item glib-or-gtk-wrap
6181 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6182 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6184 @item glib-or-gtk-compile-schemas
6185 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6186 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6190 Lastly, for packages that do not need anything as sophisticated, a
6191 ``trivial'' build system is provided. It is trivial in the sense that
6192 it provides basically no support: it does not pull any implicit inputs,
6193 and does not have a notion of build phases.
6195 @defvr {Scheme Variable} trivial-build-system
6196 This variable is exported by @code{(guix build-system trivial)}.
6198 This build system requires a @code{#:builder} argument. This argument
6199 must be a Scheme expression that builds the package output(s)---as
6200 with @code{build-expression->derivation} (@pxref{Derivations,
6201 @code{build-expression->derivation}}).
6211 Conceptually, the @dfn{store} is the place where derivations that have
6212 been built successfully are stored---by default, @file{/gnu/store}.
6213 Sub-directories in the store are referred to as @dfn{store items} or
6214 sometimes @dfn{store paths}. The store has an associated database that
6215 contains information such as the store paths referred to by each store
6216 path, and the list of @emph{valid} store items---results of successful
6217 builds. This database resides in @file{@var{localstatedir}/guix/db},
6218 where @var{localstatedir} is the state directory specified @i{via}
6219 @option{--localstatedir} at configure time, usually @file{/var}.
6221 The store is @emph{always} accessed by the daemon on behalf of its clients
6222 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6223 connect to the daemon over a Unix-domain socket, send requests to it,
6224 and read the result---these are remote procedure calls, or RPCs.
6227 Users must @emph{never} modify files under @file{/gnu/store} directly.
6228 This would lead to inconsistencies and break the immutability
6229 assumptions of Guix's functional model (@pxref{Introduction}).
6231 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6232 how to check the integrity of the store and attempt recovery from
6233 accidental modifications.
6236 The @code{(guix store)} module provides procedures to connect to the
6237 daemon, and to perform RPCs. These are described below. By default,
6238 @code{open-connection}, and thus all the @command{guix} commands,
6239 connect to the local daemon or to the URI specified by the
6240 @code{GUIX_DAEMON_SOCKET} environment variable.
6242 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6243 When set, the value of this variable should be a file name or a URI
6244 designating the daemon endpoint. When it is a file name, it denotes a
6245 Unix-domain socket to connect to. In addition to file names, the
6246 supported URI schemes are:
6251 These are for Unix-domain sockets.
6252 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6253 @file{/var/guix/daemon-socket/socket}.
6256 @cindex daemon, remote access
6257 @cindex remote access to the daemon
6258 @cindex daemon, cluster setup
6259 @cindex clusters, daemon setup
6260 These URIs denote connections over TCP/IP, without encryption nor
6261 authentication of the remote host. The URI must specify the host name
6262 and optionally a port number (by default port 44146 is used):
6265 guix://master.guix.example.org:1234
6268 This setup is suitable on local networks, such as clusters, where only
6269 trusted nodes may connect to the build daemon at
6270 @code{master.guix.example.org}.
6272 The @code{--listen} option of @command{guix-daemon} can be used to
6273 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6277 @cindex SSH access to build daemons
6278 These URIs allow you to connect to a remote daemon over
6279 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
6280 A typical URL might look like this:
6283 ssh://charlie@@guix.example.org:22
6286 As for @command{guix copy}, the usual OpenSSH client configuration files
6287 are honored (@pxref{Invoking guix copy}).
6290 Additional URI schemes may be supported in the future.
6292 @c XXX: Remove this note when the protocol incurs fewer round trips
6293 @c and when (guix derivations) no longer relies on file system access.
6295 The ability to connect to remote build daemons is considered
6296 experimental as of @value{VERSION}. Please get in touch with us to
6297 share any problems or suggestions you may have (@pxref{Contributing}).
6301 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6302 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6303 @var{reserve-space?} is true, instruct it to reserve a little bit of
6304 extra space on the file system so that the garbage collector can still
6305 operate should the disk become full. Return a server object.
6307 @var{file} defaults to @var{%default-socket-path}, which is the normal
6308 location given the options that were passed to @command{configure}.
6311 @deffn {Scheme Procedure} close-connection @var{server}
6312 Close the connection to @var{server}.
6315 @defvr {Scheme Variable} current-build-output-port
6316 This variable is bound to a SRFI-39 parameter, which refers to the port
6317 where build and error logs sent by the daemon should be written.
6320 Procedures that make RPCs all take a server object as their first
6323 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6324 @cindex invalid store items
6325 Return @code{#t} when @var{path} designates a valid store item and
6326 @code{#f} otherwise (an invalid item may exist on disk but still be
6327 invalid, for instance because it is the result of an aborted or failed
6330 A @code{&store-protocol-error} condition is raised if @var{path} is not
6331 prefixed by the store directory (@file{/gnu/store}).
6334 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6335 Add @var{text} under file @var{name} in the store, and return its store
6336 path. @var{references} is the list of store paths referred to by the
6337 resulting store path.
6340 @deffn {Scheme Procedure} build-derivations @var{server} @var{derivations}
6341 Build @var{derivations} (a list of @code{<derivation>} objects or
6342 derivation paths), and return when the worker is done building them.
6343 Return @code{#t} on success.
6346 Note that the @code{(guix monads)} module provides a monad as well as
6347 monadic versions of the above procedures, with the goal of making it
6348 more convenient to work with code that accesses the store (@pxref{The
6352 @i{This section is currently incomplete.}
6355 @section Derivations
6358 Low-level build actions and the environment in which they are performed
6359 are represented by @dfn{derivations}. A derivation contains the
6360 following pieces of information:
6364 The outputs of the derivation---derivations produce at least one file or
6365 directory in the store, but may produce more.
6368 @cindex build-time dependencies
6369 @cindex dependencies, build-time
6370 The inputs of the derivations---i.e., its build-time dependencies---which may
6371 be other derivations or plain files in the store (patches, build scripts,
6375 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
6378 The file name of a build script in the store, along with the arguments
6382 A list of environment variables to be defined.
6386 @cindex derivation path
6387 Derivations allow clients of the daemon to communicate build actions to
6388 the store. They exist in two forms: as an in-memory representation,
6389 both on the client- and daemon-side, and as files in the store whose
6390 name end in @code{.drv}---these files are referred to as @dfn{derivation
6391 paths}. Derivations paths can be passed to the @code{build-derivations}
6392 procedure to perform the build actions they prescribe (@pxref{The
6395 @cindex fixed-output derivations
6396 Operations such as file downloads and version-control checkouts for
6397 which the expected content hash is known in advance are modeled as
6398 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
6399 of a fixed-output derivation are independent of its inputs---e.g., a
6400 source code download produces the same result regardless of the download
6401 method and tools being used.
6404 @cindex run-time dependencies
6405 @cindex dependencies, run-time
6406 The outputs of derivations---i.e., the build results---have a set of
6407 @dfn{references}, as reported by the @code{references} RPC or the
6408 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
6409 are the set of run-time dependencies of the build results. References are a
6410 subset of the inputs of the derivation; this subset is automatically computed
6411 by the build daemon by scanning all the files in the outputs.
6413 The @code{(guix derivations)} module provides a representation of
6414 derivations as Scheme objects, along with procedures to create and
6415 otherwise manipulate derivations. The lowest-level primitive to create
6416 a derivation is the @code{derivation} procedure:
6418 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
6419 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6420 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
6421 [#:system (%current-system)] [#:references-graphs #f] @
6422 [#:allowed-references #f] [#:disallowed-references #f] @
6423 [#:leaked-env-vars #f] [#:local-build? #f] @
6424 [#:substitutable? #t] [#:properties '()]
6425 Build a derivation with the given arguments, and return the resulting
6426 @code{<derivation>} object.
6428 When @var{hash} and @var{hash-algo} are given, a
6429 @dfn{fixed-output derivation} is created---i.e., one whose result is
6430 known in advance, such as a file download. If, in addition,
6431 @var{recursive?} is true, then that fixed output may be an executable
6432 file or a directory and @var{hash} must be the hash of an archive
6433 containing this output.
6435 When @var{references-graphs} is true, it must be a list of file
6436 name/store path pairs. In that case, the reference graph of each store
6437 path is exported in the build environment in the corresponding file, in
6438 a simple text format.
6440 When @var{allowed-references} is true, it must be a list of store items
6441 or outputs that the derivation's output may refer to. Likewise,
6442 @var{disallowed-references}, if true, must be a list of things the
6443 outputs may @emph{not} refer to.
6445 When @var{leaked-env-vars} is true, it must be a list of strings
6446 denoting environment variables that are allowed to ``leak'' from the
6447 daemon's environment to the build environment. This is only applicable
6448 to fixed-output derivations---i.e., when @var{hash} is true. The main
6449 use is to allow variables such as @code{http_proxy} to be passed to
6450 derivations that download files.
6452 When @var{local-build?} is true, declare that the derivation is not a
6453 good candidate for offloading and should rather be built locally
6454 (@pxref{Daemon Offload Setup}). This is the case for small derivations
6455 where the costs of data transfers would outweigh the benefits.
6457 When @var{substitutable?} is false, declare that substitutes of the
6458 derivation's output should not be used (@pxref{Substitutes}). This is
6459 useful, for instance, when building packages that capture details of the
6460 host CPU instruction set.
6462 @var{properties} must be an association list describing ``properties'' of the
6463 derivation. It is kept as-is, uninterpreted, in the derivation.
6467 Here's an example with a shell script as its builder, assuming
6468 @var{store} is an open connection to the daemon, and @var{bash} points
6469 to a Bash executable in the store:
6472 (use-modules (guix utils)
6476 (let ((builder ; add the Bash script to the store
6477 (add-text-to-store store "my-builder.sh"
6478 "echo hello world > $out\n" '())))
6479 (derivation store "foo"
6480 bash `("-e" ,builder)
6481 #:inputs `((,bash) (,builder))
6482 #:env-vars '(("HOME" . "/homeless"))))
6483 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
6486 As can be guessed, this primitive is cumbersome to use directly. A
6487 better approach is to write build scripts in Scheme, of course! The
6488 best course of action for that is to write the build code as a
6489 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
6490 information, @pxref{G-Expressions}.
6492 Once upon a time, @code{gexp->derivation} did not exist and constructing
6493 derivations with build code written in Scheme was achieved with
6494 @code{build-expression->derivation}, documented below. This procedure
6495 is now deprecated in favor of the much nicer @code{gexp->derivation}.
6497 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
6498 @var{name} @var{exp} @
6499 [#:system (%current-system)] [#:inputs '()] @
6500 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6501 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
6502 [#:references-graphs #f] [#:allowed-references #f] @
6503 [#:disallowed-references #f] @
6504 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
6505 Return a derivation that executes Scheme expression @var{exp} as a
6506 builder for derivation @var{name}. @var{inputs} must be a list of
6507 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
6508 @code{"out"} is assumed. @var{modules} is a list of names of Guile
6509 modules from the current search path to be copied in the store,
6510 compiled, and made available in the load path during the execution of
6511 @var{exp}---e.g., @code{((guix build utils) (guix build
6512 gnu-build-system))}.
6514 @var{exp} is evaluated in an environment where @code{%outputs} is bound
6515 to a list of output/path pairs, and where @code{%build-inputs} is bound
6516 to a list of string/output-path pairs made from @var{inputs}.
6517 Optionally, @var{env-vars} is a list of string pairs specifying the name
6518 and value of environment variables visible to the builder. The builder
6519 terminates by passing the result of @var{exp} to @code{exit}; thus, when
6520 @var{exp} returns @code{#f}, the build is considered to have failed.
6522 @var{exp} is built using @var{guile-for-build} (a derivation). When
6523 @var{guile-for-build} is omitted or is @code{#f}, the value of the
6524 @code{%guile-for-build} fluid is used instead.
6526 See the @code{derivation} procedure for the meaning of
6527 @var{references-graphs}, @var{allowed-references},
6528 @var{disallowed-references}, @var{local-build?}, and
6529 @var{substitutable?}.
6533 Here's an example of a single-output derivation that creates a directory
6534 containing one file:
6537 (let ((builder '(let ((out (assoc-ref %outputs "out")))
6538 (mkdir out) ; create /gnu/store/@dots{}-goo
6539 (call-with-output-file (string-append out "/test")
6541 (display '(hello guix) p))))))
6542 (build-expression->derivation store "goo" builder))
6544 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
6548 @node The Store Monad
6549 @section The Store Monad
6553 The procedures that operate on the store described in the previous
6554 sections all take an open connection to the build daemon as their first
6555 argument. Although the underlying model is functional, they either have
6556 side effects or depend on the current state of the store.
6558 The former is inconvenient: the connection to the build daemon has to be
6559 carried around in all those functions, making it impossible to compose
6560 functions that do not take that parameter with functions that do. The
6561 latter can be problematic: since store operations have side effects
6562 and/or depend on external state, they have to be properly sequenced.
6564 @cindex monadic values
6565 @cindex monadic functions
6566 This is where the @code{(guix monads)} module comes in. This module
6567 provides a framework for working with @dfn{monads}, and a particularly
6568 useful monad for our uses, the @dfn{store monad}. Monads are a
6569 construct that allows two things: associating ``context'' with values
6570 (in our case, the context is the store), and building sequences of
6571 computations (here computations include accesses to the store). Values
6572 in a monad---values that carry this additional context---are called
6573 @dfn{monadic values}; procedures that return such values are called
6574 @dfn{monadic procedures}.
6576 Consider this ``normal'' procedure:
6579 (define (sh-symlink store)
6580 ;; Return a derivation that symlinks the 'bash' executable.
6581 (let* ((drv (package-derivation store bash))
6582 (out (derivation->output-path drv))
6583 (sh (string-append out "/bin/bash")))
6584 (build-expression->derivation store "sh"
6585 `(symlink ,sh %output))))
6588 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
6589 as a monadic function:
6592 (define (sh-symlink)
6593 ;; Same, but return a monadic value.
6594 (mlet %store-monad ((drv (package->derivation bash)))
6595 (gexp->derivation "sh"
6596 #~(symlink (string-append #$drv "/bin/bash")
6600 There are several things to note in the second version: the @code{store}
6601 parameter is now implicit and is ``threaded'' in the calls to the
6602 @code{package->derivation} and @code{gexp->derivation} monadic
6603 procedures, and the monadic value returned by @code{package->derivation}
6604 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
6606 As it turns out, the call to @code{package->derivation} can even be
6607 omitted since it will take place implicitly, as we will see later
6608 (@pxref{G-Expressions}):
6611 (define (sh-symlink)
6612 (gexp->derivation "sh"
6613 #~(symlink (string-append #$bash "/bin/bash")
6618 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
6619 @c for the funny quote.
6620 Calling the monadic @code{sh-symlink} has no effect. As someone once
6621 said, ``you exit a monad like you exit a building on fire: by running''.
6622 So, to exit the monad and get the desired effect, one must use
6623 @code{run-with-store}:
6626 (run-with-store (open-connection) (sh-symlink))
6627 @result{} /gnu/store/...-sh-symlink
6630 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
6631 new ``meta-commands'' to make it easier to deal with monadic procedures:
6632 @code{run-in-store}, and @code{enter-store-monad}. The former is used
6633 to ``run'' a single monadic value through the store:
6636 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
6637 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6640 The latter enters a recursive REPL, where all the return values are
6641 automatically run through the store:
6644 scheme@@(guile-user)> ,enter-store-monad
6645 store-monad@@(guile-user) [1]> (package->derivation hello)
6646 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6647 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
6648 $3 = "/gnu/store/@dots{}-foo"
6649 store-monad@@(guile-user) [1]> ,q
6650 scheme@@(guile-user)>
6654 Note that non-monadic values cannot be returned in the
6655 @code{store-monad} REPL.
6657 The main syntactic forms to deal with monads in general are provided by
6658 the @code{(guix monads)} module and are described below.
6660 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
6661 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
6665 @deffn {Scheme Syntax} return @var{val}
6666 Return a monadic value that encapsulates @var{val}.
6669 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
6670 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
6671 procedures @var{mproc}@dots{}@footnote{This operation is commonly
6672 referred to as ``bind'', but that name denotes an unrelated procedure in
6673 Guile. Thus we use this somewhat cryptic symbol inherited from the
6674 Haskell language.}. There can be one @var{mproc} or several of them, as
6679 (with-monad %state-monad
6681 (lambda (x) (return (+ 1 x)))
6682 (lambda (x) (return (* 2 x)))))
6686 @result{} some-state
6690 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
6692 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
6694 Bind the variables @var{var} to the monadic values @var{mval} in
6695 @var{body}, which is a sequence of expressions. As with the bind
6696 operator, this can be thought of as ``unpacking'' the raw, non-monadic
6697 value ``contained'' in @var{mval} and making @var{var} refer to that
6698 raw, non-monadic value within the scope of the @var{body}. The form
6699 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
6700 @var{val}, as per @code{let}. The binding operations occur in sequence
6701 from left to right. The last expression of @var{body} must be a monadic
6702 expression, and its result will become the result of the @code{mlet} or
6703 @code{mlet*} when run in the @var{monad}.
6705 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
6706 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
6709 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
6710 Bind @var{mexp} and the following monadic expressions in sequence,
6711 returning the result of the last expression. Every expression in the
6712 sequence must be a monadic expression.
6714 This is akin to @code{mlet}, except that the return values of the
6715 monadic expressions are ignored. In that sense, it is analogous to
6716 @code{begin}, but applied to monadic expressions.
6719 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
6720 When @var{condition} is true, evaluate the sequence of monadic
6721 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6722 @var{condition} is false, return @code{*unspecified*} in the current
6723 monad. Every expression in the sequence must be a monadic expression.
6726 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
6727 When @var{condition} is false, evaluate the sequence of monadic
6728 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6729 @var{condition} is true, return @code{*unspecified*} in the current
6730 monad. Every expression in the sequence must be a monadic expression.
6734 The @code{(guix monads)} module provides the @dfn{state monad}, which
6735 allows an additional value---the state---to be @emph{threaded} through
6736 monadic procedure calls.
6738 @defvr {Scheme Variable} %state-monad
6739 The state monad. Procedures in the state monad can access and change
6740 the state that is threaded.
6742 Consider the example below. The @code{square} procedure returns a value
6743 in the state monad. It returns the square of its argument, but also
6744 increments the current state value:
6748 (mlet %state-monad ((count (current-state)))
6749 (mbegin %state-monad
6750 (set-current-state (+ 1 count))
6753 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
6758 When ``run'' through @var{%state-monad}, we obtain that additional state
6759 value, which is the number of @code{square} calls.
6762 @deffn {Monadic Procedure} current-state
6763 Return the current state as a monadic value.
6766 @deffn {Monadic Procedure} set-current-state @var{value}
6767 Set the current state to @var{value} and return the previous state as a
6771 @deffn {Monadic Procedure} state-push @var{value}
6772 Push @var{value} to the current state, which is assumed to be a list,
6773 and return the previous state as a monadic value.
6776 @deffn {Monadic Procedure} state-pop
6777 Pop a value from the current state and return it as a monadic value.
6778 The state is assumed to be a list.
6781 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
6782 Run monadic value @var{mval} starting with @var{state} as the initial
6783 state. Return two values: the resulting value, and the resulting state.
6786 The main interface to the store monad, provided by the @code{(guix
6787 store)} module, is as follows.
6789 @defvr {Scheme Variable} %store-monad
6790 The store monad---an alias for @var{%state-monad}.
6792 Values in the store monad encapsulate accesses to the store. When its
6793 effect is needed, a value of the store monad must be ``evaluated'' by
6794 passing it to the @code{run-with-store} procedure (see below.)
6797 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
6798 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
6799 open store connection.
6802 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
6803 Return as a monadic value the absolute file name in the store of the file
6804 containing @var{text}, a string. @var{references} is a list of store items that the
6805 resulting text file refers to; it defaults to the empty list.
6808 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
6809 Return as a monadic value the absolute file name in the store of the file
6810 containing @var{data}, a bytevector. @var{references} is a list of store
6811 items that the resulting binary file refers to; it defaults to the empty list.
6814 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
6815 [#:recursive? #t] [#:select? (const #t)]
6816 Return the name of @var{file} once interned in the store. Use
6817 @var{name} as its store name, or the basename of @var{file} if
6818 @var{name} is omitted.
6820 When @var{recursive?} is true, the contents of @var{file} are added
6821 recursively; if @var{file} designates a flat file and @var{recursive?}
6822 is true, its contents are added, and its permission bits are kept.
6824 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
6825 @var{stat})} for each directory entry, where @var{file} is the entry's
6826 absolute file name and @var{stat} is the result of @code{lstat}; exclude
6827 entries for which @var{select?} does not return true.
6829 The example below adds a file to the store, under two different names:
6832 (run-with-store (open-connection)
6833 (mlet %store-monad ((a (interned-file "README"))
6834 (b (interned-file "README" "LEGU-MIN")))
6835 (return (list a b))))
6837 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
6842 The @code{(guix packages)} module exports the following package-related
6845 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
6846 [#:system (%current-system)] [#:target #f] @
6849 value in the absolute file name of @var{file} within the @var{output}
6850 directory of @var{package}. When @var{file} is omitted, return the name
6851 of the @var{output} directory of @var{package}. When @var{target} is
6852 true, use it as a cross-compilation target triplet.
6855 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
6856 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
6857 @var{target} [@var{system}]
6858 Monadic version of @code{package-derivation} and
6859 @code{package-cross-derivation} (@pxref{Defining Packages}).
6864 @section G-Expressions
6866 @cindex G-expression
6867 @cindex build code quoting
6868 So we have ``derivations'', which represent a sequence of build actions
6869 to be performed to produce an item in the store (@pxref{Derivations}).
6870 These build actions are performed when asking the daemon to actually
6871 build the derivations; they are run by the daemon in a container
6872 (@pxref{Invoking guix-daemon}).
6874 @cindex strata of code
6875 It should come as no surprise that we like to write these build actions
6876 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
6877 code@footnote{The term @dfn{stratum} in this context was coined by
6878 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
6879 Kiselyov, who has written insightful
6880 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
6881 on this topic}, refers to this kind of code generation as
6882 @dfn{staging}.}: the ``host code''---code that defines packages, talks
6883 to the daemon, etc.---and the ``build code''---code that actually
6884 performs build actions, such as making directories, invoking
6885 @command{make}, etc.
6887 To describe a derivation and its build actions, one typically needs to
6888 embed build code inside host code. It boils down to manipulating build
6889 code as data, and the homoiconicity of Scheme---code has a direct
6890 representation as data---comes in handy for that. But we need more than
6891 the normal @code{quasiquote} mechanism in Scheme to construct build
6894 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
6895 S-expressions adapted to build expressions. G-expressions, or
6896 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
6897 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
6898 @code{#$}, and @code{#$@@}), which are comparable to
6899 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
6900 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
6901 GNU Guile Reference Manual}). However, there are major differences:
6905 Gexps are meant to be written to a file and run or manipulated by other
6909 When a high-level object such as a package or derivation is unquoted
6910 inside a gexp, the result is as if its output file name had been
6914 Gexps carry information about the packages or derivations they refer to,
6915 and these dependencies are automatically added as inputs to the build
6916 processes that use them.
6919 @cindex lowering, of high-level objects in gexps
6920 This mechanism is not limited to package and derivation
6921 objects: @dfn{compilers} able to ``lower'' other high-level objects to
6922 derivations or files in the store can be defined,
6923 such that these objects can also be inserted
6924 into gexps. For example, a useful type of high-level objects that can be
6925 inserted in a gexp is ``file-like objects'', which make it easy to
6926 add files to the store and to refer to them in
6927 derivations and such (see @code{local-file} and @code{plain-file}
6930 To illustrate the idea, here is an example of a gexp:
6937 (symlink (string-append #$coreutils "/bin/ls")
6941 This gexp can be passed to @code{gexp->derivation}; we obtain a
6942 derivation that builds a directory containing exactly one symlink to
6943 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
6946 (gexp->derivation "the-thing" build-exp)
6949 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
6950 substituted to the reference to the @var{coreutils} package in the
6951 actual build code, and @var{coreutils} is automatically made an input to
6952 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
6953 output)}) is replaced by a string containing the directory name of the
6954 output of the derivation.
6956 @cindex cross compilation
6957 In a cross-compilation context, it is useful to distinguish between
6958 references to the @emph{native} build of a package---that can run on the
6959 host---versus references to cross builds of a package. To that end, the
6960 @code{#+} plays the same role as @code{#$}, but is a reference to a
6961 native package build:
6964 (gexp->derivation "vi"
6967 (system* (string-append #+coreutils "/bin/ln")
6969 (string-append #$emacs "/bin/emacs")
6970 (string-append #$output "/bin/vi")))
6971 #:target "mips64el-linux-gnu")
6975 In the example above, the native build of @var{coreutils} is used, so
6976 that @command{ln} can actually run on the host; but then the
6977 cross-compiled build of @var{emacs} is referenced.
6979 @cindex imported modules, for gexps
6980 @findex with-imported-modules
6981 Another gexp feature is @dfn{imported modules}: sometimes you want to be
6982 able to use certain Guile modules from the ``host environment'' in the
6983 gexp, so those modules should be imported in the ``build environment''.
6984 The @code{with-imported-modules} form allows you to express that:
6987 (let ((build (with-imported-modules '((guix build utils))
6989 (use-modules (guix build utils))
6990 (mkdir-p (string-append #$output "/bin"))))))
6991 (gexp->derivation "empty-dir"
6994 (display "success!\n")
6999 In this example, the @code{(guix build utils)} module is automatically
7000 pulled into the isolated build environment of our gexp, such that
7001 @code{(use-modules (guix build utils))} works as expected.
7003 @cindex module closure
7004 @findex source-module-closure
7005 Usually you want the @emph{closure} of the module to be imported---i.e.,
7006 the module itself and all the modules it depends on---rather than just
7007 the module; failing to do that, attempts to use the module will fail
7008 because of missing dependent modules. The @code{source-module-closure}
7009 procedure computes the closure of a module by looking at its source file
7010 headers, which comes in handy in this case:
7013 (use-modules (guix modules)) ;for 'source-module-closure'
7015 (with-imported-modules (source-module-closure
7016 '((guix build utils)
7018 (gexp->derivation "something-with-vms"
7020 (use-modules (guix build utils)
7025 @cindex extensions, for gexps
7026 @findex with-extensions
7027 In the same vein, sometimes you want to import not just pure-Scheme
7028 modules, but also ``extensions'' such as Guile bindings to C libraries
7029 or other ``full-blown'' packages. Say you need the @code{guile-json}
7030 package available on the build side, here's how you would do it:
7033 (use-modules (gnu packages guile)) ;for 'guile-json'
7035 (with-extensions (list guile-json)
7036 (gexp->derivation "something-with-json"
7038 (use-modules (json))
7042 The syntactic form to construct gexps is summarized below.
7044 @deffn {Scheme Syntax} #~@var{exp}
7045 @deffnx {Scheme Syntax} (gexp @var{exp})
7046 Return a G-expression containing @var{exp}. @var{exp} may contain one
7047 or more of the following forms:
7051 @itemx (ungexp @var{obj})
7052 Introduce a reference to @var{obj}. @var{obj} may have one of the
7053 supported types, for example a package or a
7054 derivation, in which case the @code{ungexp} form is replaced by its
7055 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7057 If @var{obj} is a list, it is traversed and references to supported
7058 objects are substituted similarly.
7060 If @var{obj} is another gexp, its contents are inserted and its
7061 dependencies are added to those of the containing gexp.
7063 If @var{obj} is another kind of object, it is inserted as is.
7065 @item #$@var{obj}:@var{output}
7066 @itemx (ungexp @var{obj} @var{output})
7067 This is like the form above, but referring explicitly to the
7068 @var{output} of @var{obj}---this is useful when @var{obj} produces
7069 multiple outputs (@pxref{Packages with Multiple Outputs}).
7072 @itemx #+@var{obj}:output
7073 @itemx (ungexp-native @var{obj})
7074 @itemx (ungexp-native @var{obj} @var{output})
7075 Same as @code{ungexp}, but produces a reference to the @emph{native}
7076 build of @var{obj} when used in a cross compilation context.
7078 @item #$output[:@var{output}]
7079 @itemx (ungexp output [@var{output}])
7080 Insert a reference to derivation output @var{output}, or to the main
7081 output when @var{output} is omitted.
7083 This only makes sense for gexps passed to @code{gexp->derivation}.
7086 @itemx (ungexp-splicing @var{lst})
7087 Like the above, but splices the contents of @var{lst} inside the
7091 @itemx (ungexp-native-splicing @var{lst})
7092 Like the above, but refers to native builds of the objects listed in
7097 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7098 of the @code{gexp?} type (see below.)
7101 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7102 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7103 in their execution environment.
7105 Each item in @var{modules} can be the name of a module, such as
7106 @code{(guix build utils)}, or it can be a module name, followed by an
7107 arrow, followed by a file-like object:
7110 `((guix build utils)
7112 ((guix config) => ,(scheme-file "config.scm"
7113 #~(define-module @dots{}))))
7117 In the example above, the first two modules are taken from the search
7118 path, and the last one is created from the given file-like object.
7120 This form has @emph{lexical} scope: it has an effect on the gexps
7121 directly defined in @var{body}@dots{}, but not on those defined, say, in
7122 procedures called from @var{body}@dots{}.
7125 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7126 Mark the gexps defined in @var{body}@dots{} as requiring
7127 @var{extensions} in their build and execution environment.
7128 @var{extensions} is typically a list of package objects such as those
7129 defined in the @code{(gnu packages guile)} module.
7131 Concretely, the packages listed in @var{extensions} are added to the
7132 load path while compiling imported modules in @var{body}@dots{}; they
7133 are also added to the load path of the gexp returned by
7137 @deffn {Scheme Procedure} gexp? @var{obj}
7138 Return @code{#t} if @var{obj} is a G-expression.
7141 G-expressions are meant to be written to disk, either as code building
7142 some derivation, or as plain files in the store. The monadic procedures
7143 below allow you to do that (@pxref{The Store Monad}, for more
7144 information about monads.)
7146 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7147 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7148 [#:hash #f] [#:hash-algo #f] @
7149 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7150 [#:module-path @var{%load-path}] @
7151 [#:effective-version "2.2"] @
7152 [#:references-graphs #f] [#:allowed-references #f] @
7153 [#:disallowed-references #f] @
7154 [#:leaked-env-vars #f] @
7155 [#:script-name (string-append @var{name} "-builder")] @
7156 [#:deprecation-warnings #f] @
7157 [#:local-build? #f] [#:substitutable? #t] @
7158 [#:properties '()] [#:guile-for-build #f]
7159 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7160 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7161 stored in a file called @var{script-name}. When @var{target} is true,
7162 it is used as the cross-compilation target triplet for packages referred
7165 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7167 make @var{modules} available in the evaluation context of @var{exp};
7168 @var{modules} is a list of names of Guile modules searched in
7169 @var{module-path} to be copied in the store, compiled, and made available in
7170 the load path during the execution of @var{exp}---e.g., @code{((guix
7171 build utils) (guix build gnu-build-system))}.
7173 @var{effective-version} determines the string to use when adding extensions of
7174 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7176 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7179 When @var{references-graphs} is true, it must be a list of tuples of one of the
7183 (@var{file-name} @var{package})
7184 (@var{file-name} @var{package} @var{output})
7185 (@var{file-name} @var{derivation})
7186 (@var{file-name} @var{derivation} @var{output})
7187 (@var{file-name} @var{store-item})
7190 The right-hand-side of each element of @var{references-graphs} is automatically made
7191 an input of the build process of @var{exp}. In the build environment, each
7192 @var{file-name} contains the reference graph of the corresponding item, in a simple
7195 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7196 In the latter case, the list denotes store items that the result is allowed to
7197 refer to. Any reference to another store item will lead to a build error.
7198 Similarly for @var{disallowed-references}, which can list items that must not be
7199 referenced by the outputs.
7201 @var{deprecation-warnings} determines whether to show deprecation warnings while
7202 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7204 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7207 @cindex file-like objects
7208 The @code{local-file}, @code{plain-file}, @code{computed-file},
7209 @code{program-file}, and @code{scheme-file} procedures below return
7210 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7211 these objects lead to a file in the store. Consider this G-expression:
7214 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7215 #$(local-file "/tmp/my-nscd.conf"))
7218 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7219 to the store. Once expanded, for instance @i{via}
7220 @code{gexp->derivation}, the G-expression refers to that copy under
7221 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7222 does not have any effect on what the G-expression does.
7223 @code{plain-file} can be used similarly; it differs in that the file
7224 content is directly passed as a string.
7226 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7227 [#:recursive? #f] [#:select? (const #t)]
7228 Return an object representing local file @var{file} to add to the store; this
7229 object can be used in a gexp. If @var{file} is a relative file name, it is looked
7230 up relative to the source file where this form appears. @var{file} will be added to
7231 the store under @var{name}--by default the base name of @var{file}.
7233 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7234 designates a flat file and @var{recursive?} is true, its contents are added, and its
7235 permission bits are kept.
7237 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7238 @var{stat})} for each directory entry, where @var{file} is the entry's
7239 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7240 entries for which @var{select?} does not return true.
7242 This is the declarative counterpart of the @code{interned-file} monadic
7243 procedure (@pxref{The Store Monad, @code{interned-file}}).
7246 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7247 Return an object representing a text file called @var{name} with the given
7248 @var{content} (a string or a bytevector) to be added to the store.
7250 This is the declarative counterpart of @code{text-file}.
7253 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7254 [#:options '(#:local-build? #t)]
7255 Return an object representing the store item @var{name}, a file or
7256 directory computed by @var{gexp}. @var{options}
7257 is a list of additional arguments to pass to @code{gexp->derivation}.
7259 This is the declarative counterpart of @code{gexp->derivation}.
7262 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7263 [#:guile (default-guile)] [#:module-path %load-path]
7264 Return an executable script @var{name} that runs @var{exp} using
7265 @var{guile}, with @var{exp}'s imported modules in its search path.
7266 Look up @var{exp}'s modules in @var{module-path}.
7268 The example below builds a script that simply invokes the @command{ls}
7272 (use-modules (guix gexp) (gnu packages base))
7274 (gexp->script "list-files"
7275 #~(execl #$(file-append coreutils "/bin/ls")
7279 When ``running'' it through the store (@pxref{The Store Monad,
7280 @code{run-with-store}}), we obtain a derivation that produces an
7281 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7284 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7286 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7290 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7291 [#:guile #f] [#:module-path %load-path]
7292 Return an object representing the executable store item @var{name} that
7293 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7294 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7296 This is the declarative counterpart of @code{gexp->script}.
7299 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7300 [#:set-load-path? #t] [#:module-path %load-path] @
7302 [#:guile (default-guile)]
7303 Return a derivation that builds a file @var{name} containing @var{exp}.
7304 When @var{splice?} is true, @var{exp} is considered to be a list of
7305 expressions that will be spliced in the resulting file.
7307 When @var{set-load-path?} is true, emit code in the resulting file to
7308 set @code{%load-path} and @code{%load-compiled-path} to honor
7309 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7312 The resulting file holds references to all the dependencies of @var{exp}
7313 or a subset thereof.
7316 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
7317 Return an object representing the Scheme file @var{name} that contains
7320 This is the declarative counterpart of @code{gexp->file}.
7323 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7324 Return as a monadic value a derivation that builds a text file
7325 containing all of @var{text}. @var{text} may list, in addition to
7326 strings, objects of any type that can be used in a gexp: packages,
7327 derivations, local file objects, etc. The resulting store file holds
7328 references to all these.
7330 This variant should be preferred over @code{text-file} anytime the file
7331 to create will reference items from the store. This is typically the
7332 case when building a configuration file that embeds store file names,
7336 (define (profile.sh)
7337 ;; Return the name of a shell script in the store that
7338 ;; initializes the 'PATH' environment variable.
7339 (text-file* "profile.sh"
7340 "export PATH=" coreutils "/bin:"
7341 grep "/bin:" sed "/bin\n"))
7344 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
7345 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
7346 preventing them from being garbage-collected during its lifetime.
7349 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
7350 Return an object representing store file @var{name} containing
7351 @var{text}. @var{text} is a sequence of strings and file-like objects,
7355 (mixed-text-file "profile"
7356 "export PATH=" coreutils "/bin:" grep "/bin")
7359 This is the declarative counterpart of @code{text-file*}.
7362 @deffn {Scheme Procedure} file-union @var{name} @var{files}
7363 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
7364 Each item in @var{files} must be a two-element list where the first element is the
7365 file name to use in the new directory, and the second element is a gexp
7366 denoting the target file. Here's an example:
7370 `(("hosts" ,(plain-file "hosts"
7371 "127.0.0.1 localhost"))
7372 ("bashrc" ,(plain-file "bashrc"
7373 "alias ls='ls --color=auto'"))))
7376 This yields an @code{etc} directory containing these two files.
7379 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
7380 Return a directory that is the union of @var{things}, where @var{things} is a list of
7381 file-like objects denoting directories. For example:
7384 (directory-union "guile+emacs" (list guile emacs))
7387 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
7390 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
7391 Return a file-like object that expands to the concatenation of @var{obj}
7392 and @var{suffix}, where @var{obj} is a lowerable object and each
7393 @var{suffix} is a string.
7395 As an example, consider this gexp:
7398 (gexp->script "run-uname"
7399 #~(system* #$(file-append coreutils
7403 The same effect could be achieved with:
7406 (gexp->script "run-uname"
7407 #~(system* (string-append #$coreutils
7411 There is one difference though: in the @code{file-append} case, the
7412 resulting script contains the absolute file name as a string, whereas in
7413 the second case, the resulting script contains a @code{(string-append
7414 @dots{})} expression to construct the file name @emph{at run time}.
7418 Of course, in addition to gexps embedded in ``host'' code, there are
7419 also modules containing build tools. To make it clear that they are
7420 meant to be used in the build stratum, these modules are kept in the
7421 @code{(guix build @dots{})} name space.
7423 @cindex lowering, of high-level objects in gexps
7424 Internally, high-level objects are @dfn{lowered}, using their compiler,
7425 to either derivations or store items. For instance, lowering a package
7426 yields a derivation, and lowering a @code{plain-file} yields a store
7427 item. This is achieved using the @code{lower-object} monadic procedure.
7429 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
7431 Return as a value in @var{%store-monad} the derivation or store item
7432 corresponding to @var{obj} for @var{system}, cross-compiling for
7433 @var{target} if @var{target} is true. @var{obj} must be an object that
7434 has an associated gexp compiler, such as a @code{<package>}.
7437 @node Invoking guix repl
7438 @section Invoking @command{guix repl}
7440 @cindex REPL, read-eval-print loop
7441 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
7442 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
7443 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
7444 command, @command{guix repl} guarantees that all the Guix modules and all its
7445 dependencies are available in the search path. You can use it this way:
7449 scheme@@(guile-user)> ,use (gnu packages base)
7450 scheme@@(guile-user)> coreutils
7451 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
7455 In addition, @command{guix repl} implements a simple machine-readable REPL
7456 protocol for use by @code{(guix inferior)}, a facility to interact with
7457 @dfn{inferiors}, separate processes running a potentially different revision
7460 The available options are as follows:
7463 @item --type=@var{type}
7464 @itemx -t @var{type}
7465 Start a REPL of the given @var{TYPE}, which can be one of the following:
7469 This is default, and it spawns a standard full-featured Guile REPL.
7471 Spawn a REPL that uses the machine-readable protocol. This is the protocol
7472 that the @code{(guix inferior)} module speaks.
7475 @item --listen=@var{endpoint}
7476 By default, @command{guix repl} reads from standard input and writes to
7477 standard output. When this option is passed, it will instead listen for
7478 connections on @var{endpoint}. Here are examples of valid options:
7481 @item --listen=tcp:37146
7482 Accept connections on localhost on port 37146.
7484 @item --listen=unix:/tmp/socket
7485 Accept connections on the Unix-domain socket @file{/tmp/socket}.
7489 @c *********************************************************************
7493 This section describes Guix command-line utilities. Some of them are
7494 primarily targeted at developers and users who write new package
7495 definitions, while others are more generally useful. They complement
7496 the Scheme programming interface of Guix in a convenient way.
7499 * Invoking guix build:: Building packages from the command line.
7500 * Invoking guix edit:: Editing package definitions.
7501 * Invoking guix download:: Downloading a file and printing its hash.
7502 * Invoking guix hash:: Computing the cryptographic hash of a file.
7503 * Invoking guix import:: Importing package definitions.
7504 * Invoking guix refresh:: Updating package definitions.
7505 * Invoking guix lint:: Finding errors in package definitions.
7506 * Invoking guix size:: Profiling disk usage.
7507 * Invoking guix graph:: Visualizing the graph of packages.
7508 * Invoking guix publish:: Sharing substitutes.
7509 * Invoking guix challenge:: Challenging substitute servers.
7510 * Invoking guix copy:: Copying to and from a remote store.
7511 * Invoking guix container:: Process isolation.
7512 * Invoking guix weather:: Assessing substitute availability.
7513 * Invoking guix processes:: Listing client processes.
7516 @node Invoking guix build
7517 @section Invoking @command{guix build}
7519 @cindex package building
7520 @cindex @command{guix build}
7521 The @command{guix build} command builds packages or derivations and
7522 their dependencies, and prints the resulting store paths. Note that it
7523 does not modify the user's profile---this is the job of the
7524 @command{guix package} command (@pxref{Invoking guix package}). Thus,
7525 it is mainly useful for distribution developers.
7527 The general syntax is:
7530 guix build @var{options} @var{package-or-derivation}@dots{}
7533 As an example, the following command builds the latest versions of Emacs
7534 and of Guile, displays their build logs, and finally displays the
7535 resulting directories:
7538 guix build emacs guile
7541 Similarly, the following command builds all the available packages:
7544 guix build --quiet --keep-going \
7545 `guix package -A | cut -f1,2 --output-delimiter=@@`
7548 @var{package-or-derivation} may be either the name of a package found in
7549 the software distribution such as @code{coreutils} or
7550 @code{coreutils@@8.20}, or a derivation such as
7551 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
7552 package with the corresponding name (and optionally version) is searched
7553 for among the GNU distribution modules (@pxref{Package Modules}).
7555 Alternatively, the @code{--expression} option may be used to specify a
7556 Scheme expression that evaluates to a package; this is useful when
7557 disambiguating among several same-named packages or package variants is
7560 There may be zero or more @var{options}. The available options are
7561 described in the subsections below.
7564 * Common Build Options:: Build options for most commands.
7565 * Package Transformation Options:: Creating variants of packages.
7566 * Additional Build Options:: Options specific to 'guix build'.
7567 * Debugging Build Failures:: Real life packaging experience.
7570 @node Common Build Options
7571 @subsection Common Build Options
7573 A number of options that control the build process are common to
7574 @command{guix build} and other commands that can spawn builds, such as
7575 @command{guix package} or @command{guix archive}. These are the
7580 @item --load-path=@var{directory}
7581 @itemx -L @var{directory}
7582 Add @var{directory} to the front of the package module search path
7583 (@pxref{Package Modules}).
7585 This allows users to define their own packages and make them visible to
7586 the command-line tools.
7590 Keep the build tree of failed builds. Thus, if a build fails, its build
7591 tree is kept under @file{/tmp}, in a directory whose name is shown at
7592 the end of the build log. This is useful when debugging build issues.
7593 @xref{Debugging Build Failures}, for tips and tricks on how to debug
7596 This option has no effect when connecting to a remote daemon with a
7597 @code{guix://} URI (@pxref{The Store, the @code{GUIX_DAEMON_SOCKET}
7602 Keep going when some of the derivations fail to build; return only once
7603 all the builds have either completed or failed.
7605 The default behavior is to stop as soon as one of the specified
7606 derivations has failed.
7610 Do not build the derivations.
7612 @anchor{fallback-option}
7614 When substituting a pre-built binary fails, fall back to building
7615 packages locally (@pxref{Substitution Failure}).
7617 @item --substitute-urls=@var{urls}
7618 @anchor{client-substitute-urls}
7619 Consider @var{urls} the whitespace-separated list of substitute source
7620 URLs, overriding the default list of URLs of @command{guix-daemon}
7621 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
7623 This means that substitutes may be downloaded from @var{urls}, provided
7624 they are signed by a key authorized by the system administrator
7625 (@pxref{Substitutes}).
7627 When @var{urls} is the empty string, substitutes are effectively
7630 @item --no-substitutes
7631 Do not use substitutes for build products. That is, always build things
7632 locally instead of allowing downloads of pre-built binaries
7633 (@pxref{Substitutes}).
7636 Do not ``graft'' packages. In practice, this means that package updates
7637 available as grafts are not applied. @xref{Security Updates}, for more
7638 information on grafts.
7640 @item --rounds=@var{n}
7641 Build each derivation @var{n} times in a row, and raise an error if
7642 consecutive build results are not bit-for-bit identical.
7644 This is a useful way to detect non-deterministic builds processes.
7645 Non-deterministic build processes are a problem because they make it
7646 practically impossible for users to @emph{verify} whether third-party
7647 binaries are genuine. @xref{Invoking guix challenge}, for more.
7649 Note that, currently, the differing build results are not kept around,
7650 so you will have to manually investigate in case of an error---e.g., by
7651 stashing one of the build results with @code{guix archive --export}
7652 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
7655 @item --no-build-hook
7656 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
7657 (@pxref{Daemon Offload Setup}). That is, always build things locally
7658 instead of offloading builds to remote machines.
7660 @item --max-silent-time=@var{seconds}
7661 When the build or substitution process remains silent for more than
7662 @var{seconds}, terminate it and report a build failure.
7664 By default, the daemon's setting is honored (@pxref{Invoking
7665 guix-daemon, @code{--max-silent-time}}).
7667 @item --timeout=@var{seconds}
7668 Likewise, when the build or substitution process lasts for more than
7669 @var{seconds}, terminate it and report a build failure.
7671 By default, the daemon's setting is honored (@pxref{Invoking
7672 guix-daemon, @code{--timeout}}).
7674 @c Note: This option is actually not part of %standard-build-options but
7675 @c most programs honor it.
7676 @cindex verbosity, of the command-line tools
7677 @cindex build logs, verbosity
7678 @item -v @var{level}
7679 @itemx --verbosity=@var{level}
7680 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
7681 output is produced, 1 is for quiet output, and 2 shows all the build log
7682 output on standard error.
7684 @item --cores=@var{n}
7686 Allow the use of up to @var{n} CPU cores for the build. The special
7687 value @code{0} means to use as many CPU cores as available.
7689 @item --max-jobs=@var{n}
7691 Allow at most @var{n} build jobs in parallel. @xref{Invoking
7692 guix-daemon, @code{--max-jobs}}, for details about this option and the
7693 equivalent @command{guix-daemon} option.
7695 @item --debug=@var{level}
7696 Produce debugging output coming from the build daemon. @var{level} must be an
7697 integer between 0 and 5; higher means more verbose output. Setting a level of
7698 4 or more may be helpful when debugging setup issues with the build daemon.
7702 Behind the scenes, @command{guix build} is essentially an interface to
7703 the @code{package-derivation} procedure of the @code{(guix packages)}
7704 module, and to the @code{build-derivations} procedure of the @code{(guix
7705 derivations)} module.
7707 In addition to options explicitly passed on the command line,
7708 @command{guix build} and other @command{guix} commands that support
7709 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
7711 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
7712 Users can define this variable to a list of command line options that
7713 will automatically be used by @command{guix build} and other
7714 @command{guix} commands that can perform builds, as in the example
7718 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
7721 These options are parsed independently, and the result is appended to
7722 the parsed command-line options.
7726 @node Package Transformation Options
7727 @subsection Package Transformation Options
7729 @cindex package variants
7730 Another set of command-line options supported by @command{guix build}
7731 and also @command{guix package} are @dfn{package transformation
7732 options}. These are options that make it possible to define @dfn{package
7733 variants}---for instance, packages built from different source code.
7734 This is a convenient way to create customized packages on the fly
7735 without having to type in the definitions of package variants
7736 (@pxref{Defining Packages}).
7740 @item --with-source=@var{source}
7741 @itemx --with-source=@var{package}=@var{source}
7742 @itemx --with-source=@var{package}@@@var{version}=@var{source}
7743 Use @var{source} as the source of @var{package}, and @var{version} as
7745 @var{source} must be a file name or a URL, as for @command{guix
7746 download} (@pxref{Invoking guix download}).
7748 When @var{package} is omitted,
7749 it is taken to be the package name specified on the
7750 command line that matches the base of @var{source}---e.g.,
7751 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
7752 package is @code{guile}.
7754 Likewise, when @var{version} is omitted, the version string is inferred from
7755 @var{source}; in the previous example, it is @code{2.0.10}.
7757 This option allows users to try out versions of packages other than the
7758 one provided by the distribution. The example below downloads
7759 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
7760 the @code{ed} package:
7763 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
7766 As a developer, @code{--with-source} makes it easy to test release
7770 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
7773 @dots{} or to build from a checkout in a pristine environment:
7776 $ git clone git://git.sv.gnu.org/guix.git
7777 $ guix build guix --with-source=guix@@1.0=./guix
7780 @item --with-input=@var{package}=@var{replacement}
7781 Replace dependency on @var{package} by a dependency on
7782 @var{replacement}. @var{package} must be a package name, and
7783 @var{replacement} must be a package specification such as @code{guile}
7784 or @code{guile@@1.8}.
7786 For instance, the following command builds Guix, but replaces its
7787 dependency on the current stable version of Guile with a dependency on
7788 the legacy version of Guile, @code{guile@@2.0}:
7791 guix build --with-input=guile=guile@@2.0 guix
7794 This is a recursive, deep replacement. So in this example, both
7795 @code{guix} and its dependency @code{guile-json} (which also depends on
7796 @code{guile}) get rebuilt against @code{guile@@2.0}.
7798 This is implemented using the @code{package-input-rewriting} Scheme
7799 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
7801 @item --with-graft=@var{package}=@var{replacement}
7802 This is similar to @code{--with-input} but with an important difference:
7803 instead of rebuilding the whole dependency chain, @var{replacement} is
7804 built and then @dfn{grafted} onto the binaries that were initially
7805 referring to @var{package}. @xref{Security Updates}, for more
7806 information on grafts.
7808 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
7809 and all its dependencies, replacing references to the version of GnuTLS
7810 they currently refer to:
7813 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
7816 This has the advantage of being much faster than rebuilding everything.
7817 But there is a caveat: it works if and only if @var{package} and
7818 @var{replacement} are strictly compatible---for example, if they provide
7819 a library, the application binary interface (ABI) of those libraries
7820 must be compatible. If @var{replacement} is somehow incompatible with
7821 @var{package}, then the resulting package may be unusable. Use with
7824 @item --with-git-url=@var{package}=@var{url}
7825 @cindex Git, using the latest commit
7826 @cindex latest commit, building
7827 Build @var{package} from the latest commit of the @code{master} branch of the
7828 Git repository at @var{url}. Git sub-modules of the repository are fetched,
7831 For example, the following command builds the NumPy Python library against the
7832 latest commit of the master branch of Python itself:
7835 guix build python-numpy \
7836 --with-git-url=python=https://github.com/python/cpython
7839 This option can also be combined with @code{--with-branch} or
7840 @code{--with-commit} (see below).
7842 @cindex continuous integration
7843 Obviously, since it uses the latest commit of the given branch, the result of
7844 such a command varies over time. Nevertheless it is a convenient way to
7845 rebuild entire software stacks against the latest commit of one or more
7846 packages. This is particularly useful in the context of continuous
7849 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
7850 consecutive accesses to the same repository. You may want to clean it up once
7851 in a while to save disk space.
7853 @item --with-branch=@var{package}=@var{branch}
7854 Build @var{package} from the latest commit of @var{branch}. If the
7855 @code{source} field of @var{package} is an origin with the @code{git-fetch}
7856 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
7857 repository URL is taken from that @code{source}. Otherwise you have to use
7858 @code{--with-git-url} to specify the URL of the Git repository.
7860 For instance, the following command builds @code{guile-sqlite3} from the
7861 latest commit of its @code{master} branch, and then builds @code{guix} (which
7862 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
7863 specific @code{guile-sqlite3} build:
7866 guix build --with-branch=guile-sqlite3=master cuirass
7869 @item --with-commit=@var{package}=@var{commit}
7870 This is similar to @code{--with-branch}, except that it builds from
7871 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
7872 Git commit SHA1 identifier.
7875 @node Additional Build Options
7876 @subsection Additional Build Options
7878 The command-line options presented below are specific to @command{guix
7885 Build quietly, without displaying the build log; this is equivalent to
7886 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
7887 (or similar) and can always be retrieved using the @option{--log-file} option.
7889 @item --file=@var{file}
7890 @itemx -f @var{file}
7891 Build the package, derivation, or other file-like object that the code within
7892 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
7894 As an example, @var{file} might contain a package definition like this
7895 (@pxref{Defining Packages}):
7898 @verbatiminclude package-hello.scm
7901 @item --expression=@var{expr}
7902 @itemx -e @var{expr}
7903 Build the package or derivation @var{expr} evaluates to.
7905 For example, @var{expr} may be @code{(@@ (gnu packages guile)
7906 guile-1.8)}, which unambiguously designates this specific variant of
7907 version 1.8 of Guile.
7909 Alternatively, @var{expr} may be a G-expression, in which case it is used
7910 as a build program passed to @code{gexp->derivation}
7911 (@pxref{G-Expressions}).
7913 Lastly, @var{expr} may refer to a zero-argument monadic procedure
7914 (@pxref{The Store Monad}). The procedure must return a derivation as a
7915 monadic value, which is then passed through @code{run-with-store}.
7919 Build the source derivations of the packages, rather than the packages
7922 For instance, @code{guix build -S gcc} returns something like
7923 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
7926 The returned source tarball is the result of applying any patches and
7927 code snippets specified in the package @code{origin} (@pxref{Defining
7931 Fetch and return the source of @var{package-or-derivation} and all their
7932 dependencies, recursively. This is a handy way to obtain a local copy
7933 of all the source code needed to build @var{packages}, allowing you to
7934 eventually build them even without network access. It is an extension
7935 of the @code{--source} option and can accept one of the following
7936 optional argument values:
7940 This value causes the @code{--sources} option to behave in the same way
7941 as the @code{--source} option.
7944 Build the source derivations of all packages, including any source that
7945 might be listed as @code{inputs}. This is the default value.
7948 $ guix build --sources tzdata
7949 The following derivations will be built:
7950 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
7951 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
7955 Build the source derivations of all packages, as well of all transitive
7956 inputs to the packages. This can be used e.g.@: to
7957 prefetch package source for later offline building.
7960 $ guix build --sources=transitive tzdata
7961 The following derivations will be built:
7962 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
7963 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
7964 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
7965 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
7966 /gnu/store/@dots{}-make-4.1.tar.xz.drv
7967 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
7973 @item --system=@var{system}
7974 @itemx -s @var{system}
7975 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
7976 the system type of the build host.
7979 The @code{--system} flag is for @emph{native} compilation and must not
7980 be confused with cross-compilation. See @code{--target} below for
7981 information on cross-compilation.
7984 An example use of this is on Linux-based systems, which can emulate
7985 different personalities. For instance, passing
7986 @code{--system=i686-linux} on an @code{x86_64-linux} system or
7987 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
7988 to build packages in a complete 32-bit environment.
7991 Building for an @code{armhf-linux} system is unconditionally enabled on
7992 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
7993 allow for this functionality, notably the ThunderX.
7996 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
7997 is enabled (@pxref{Virtualization Services,
7998 @code{qemu-binfmt-service-type}}), you can build for any system for
7999 which a QEMU @code{binfmt_misc} handler is installed.
8001 Builds for a system other than that of the machine you are using can
8002 also be offloaded to a remote machine of the right architecture.
8003 @xref{Daemon Offload Setup}, for more information on offloading.
8005 @item --target=@var{triplet}
8006 @cindex cross-compilation
8007 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8008 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
8009 configuration triplets,, autoconf, Autoconf}).
8011 @anchor{build-check}
8013 @cindex determinism, checking
8014 @cindex reproducibility, checking
8015 Rebuild @var{package-or-derivation}, which are already available in the
8016 store, and raise an error if the build results are not bit-for-bit
8019 This mechanism allows you to check whether previously installed
8020 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8021 of a package is deterministic. @xref{Invoking guix challenge}, for more
8022 background information and tools.
8024 When used in conjunction with @option{--keep-failed}, the differing
8025 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8026 This makes it easy to look for differences between the two results.
8029 @cindex repairing store items
8030 @cindex corruption, recovering from
8031 Attempt to repair the specified store items, if they are corrupt, by
8032 re-downloading or rebuilding them.
8034 This operation is not atomic and thus restricted to @code{root}.
8038 Return the derivation paths, not the output paths, of the given
8041 @item --root=@var{file}
8042 @itemx -r @var{file}
8043 @cindex GC roots, adding
8044 @cindex garbage collector roots, adding
8045 Make @var{file} a symlink to the result, and register it as a garbage
8048 Consequently, the results of this @command{guix build} invocation are
8049 protected from garbage collection until @var{file} is removed. When
8050 that option is omitted, build results are eligible for garbage
8051 collection as soon as the build completes. @xref{Invoking guix gc}, for
8055 @cindex build logs, access
8056 Return the build log file names or URLs for the given
8057 @var{package-or-derivation}, or raise an error if build logs are
8060 This works regardless of how packages or derivations are specified. For
8061 instance, the following invocations are equivalent:
8064 guix build --log-file `guix build -d guile`
8065 guix build --log-file `guix build guile`
8066 guix build --log-file guile
8067 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8070 If a log is unavailable locally, and unless @code{--no-substitutes} is
8071 passed, the command looks for a corresponding log on one of the
8072 substitute servers (as specified with @code{--substitute-urls}.)
8074 So for instance, imagine you want to see the build log of GDB on MIPS,
8075 but you are actually on an @code{x86_64} machine:
8078 $ guix build --log-file gdb -s mips64el-linux
8079 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8082 You can freely access a huge library of build logs!
8085 @node Debugging Build Failures
8086 @subsection Debugging Build Failures
8088 @cindex build failures, debugging
8089 When defining a new package (@pxref{Defining Packages}), you will
8090 probably find yourself spending some time debugging and tweaking the
8091 build until it succeeds. To do that, you need to operate the build
8092 commands yourself in an environment as close as possible to the one the
8095 To that end, the first thing to do is to use the @option{--keep-failed}
8096 or @option{-K} option of @command{guix build}, which will keep the
8097 failed build tree in @file{/tmp} or whatever directory you specified as
8098 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8100 From there on, you can @command{cd} to the failed build tree and source
8101 the @file{environment-variables} file, which contains all the
8102 environment variable definitions that were in place when the build
8103 failed. So let's say you're debugging a build failure in package
8104 @code{foo}; a typical session would look like this:
8108 @dots{} @i{build fails}
8109 $ cd /tmp/guix-build-foo.drv-0
8110 $ source ./environment-variables
8114 Now, you can invoke commands as if you were the daemon (almost) and
8115 troubleshoot your build process.
8117 Sometimes it happens that, for example, a package's tests pass when you
8118 run them manually but they fail when the daemon runs them. This can
8119 happen because the daemon runs builds in containers where, unlike in our
8120 environment above, network access is missing, @file{/bin/sh} does not
8121 exist, etc. (@pxref{Build Environment Setup}).
8123 In such cases, you may need to run inspect the build process from within
8124 a container similar to the one the build daemon creates:
8129 $ cd /tmp/guix-build-foo.drv-0
8130 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8131 [env]# source ./environment-variables
8135 Here, @command{guix environment -C} creates a container and spawns a new
8136 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8137 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8138 the container, which would may find handy while debugging. The
8139 @option{--no-grafts} option makes sure we get the exact same
8140 environment, with ungrafted packages (@pxref{Security Updates}, for more
8143 To get closer to a container like that used by the build daemon, we can
8144 remove @file{/bin/sh}:
8150 (Don't worry, this is harmless: this is all happening in the throw-away
8151 container created by @command{guix environment}.)
8153 The @command{strace} command is probably not in the search path, but we
8157 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8160 In this way, not only you will have reproduced the environment variables
8161 the daemon uses, you will also be running the build process in a container
8162 similar to the one the daemon uses.
8165 @node Invoking guix edit
8166 @section Invoking @command{guix edit}
8168 @cindex @command{guix edit}
8169 @cindex package definition, editing
8170 So many packages, so many source files! The @command{guix edit} command
8171 facilitates the life of users and packagers by pointing their editor at
8172 the source file containing the definition of the specified packages.
8176 guix edit gcc@@4.9 vim
8180 launches the program specified in the @code{VISUAL} or in the
8181 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8184 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8185 have created your own packages on @code{GUIX_PACKAGE_PATH}
8186 (@pxref{Package Modules}), you will be able to edit the package
8187 recipes. In other cases, you will be able to examine the read-only recipes
8188 for packages currently in the store.
8191 @node Invoking guix download
8192 @section Invoking @command{guix download}
8194 @cindex @command{guix download}
8195 @cindex downloading package sources
8196 When writing a package definition, developers typically need to download
8197 a source tarball, compute its SHA256 hash, and write that
8198 hash in the package definition (@pxref{Defining Packages}). The
8199 @command{guix download} tool helps with this task: it downloads a file
8200 from the given URI, adds it to the store, and prints both its file name
8201 in the store and its SHA256 hash.
8203 The fact that the downloaded file is added to the store saves bandwidth:
8204 when the developer eventually tries to build the newly defined package
8205 with @command{guix build}, the source tarball will not have to be
8206 downloaded again because it is already in the store. It is also a
8207 convenient way to temporarily stash files, which may be deleted
8208 eventually (@pxref{Invoking guix gc}).
8210 The @command{guix download} command supports the same URIs as used in
8211 package definitions. In particular, it supports @code{mirror://} URIs.
8212 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8213 Guile bindings for GnuTLS are available in the user's environment; when
8214 they are not available, an error is raised. @xref{Guile Preparations,
8215 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8216 GnuTLS-Guile}, for more information.
8218 @command{guix download} verifies HTTPS server certificates by loading
8219 the certificates of X.509 authorities from the directory pointed to by
8220 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8221 Certificates}), unless @option{--no-check-certificate} is used.
8223 The following options are available:
8226 @item --format=@var{fmt}
8228 Write the hash in the format specified by @var{fmt}. For more
8229 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8231 @item --no-check-certificate
8232 Do not validate the X.509 certificates of HTTPS servers.
8234 When using this option, you have @emph{absolutely no guarantee} that you
8235 are communicating with the authentic server responsible for the given
8236 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8238 @item --output=@var{file}
8239 @itemx -o @var{file}
8240 Save the downloaded file to @var{file} instead of adding it to the
8244 @node Invoking guix hash
8245 @section Invoking @command{guix hash}
8247 @cindex @command{guix hash}
8248 The @command{guix hash} command computes the SHA256 hash of a file.
8249 It is primarily a convenience tool for anyone contributing to the
8250 distribution: it computes the cryptographic hash of a file, which can be
8251 used in the definition of a package (@pxref{Defining Packages}).
8253 The general syntax is:
8256 guix hash @var{option} @var{file}
8259 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8260 hash of data read from standard input. @command{guix hash} has the
8265 @item --format=@var{fmt}
8267 Write the hash in the format specified by @var{fmt}.
8269 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8270 (@code{hex} and @code{hexadecimal} can be used as well).
8272 If the @option{--format} option is not specified, @command{guix hash}
8273 will output the hash in @code{nix-base32}. This representation is used
8274 in the definitions of packages.
8278 Compute the hash on @var{file} recursively.
8280 In this case, the hash is computed on an archive containing @var{file},
8281 including its children if it is a directory. Some of the metadata of
8282 @var{file} is part of the archive; for instance, when @var{file} is a
8283 regular file, the hash is different depending on whether @var{file} is
8284 executable or not. Metadata such as time stamps has no impact on the
8285 hash (@pxref{Invoking guix archive}).
8286 @c FIXME: Replace xref above with xref to an ``Archive'' section when
8291 When combined with @option{--recursive}, exclude version control system
8292 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
8295 As an example, here is how you would compute the hash of a Git checkout,
8296 which is useful when using the @code{git-fetch} method (@pxref{origin
8300 $ git clone http://example.org/foo.git
8306 @node Invoking guix import
8307 @section Invoking @command{guix import}
8309 @cindex importing packages
8310 @cindex package import
8311 @cindex package conversion
8312 @cindex Invoking @command{guix import}
8313 The @command{guix import} command is useful for people who would like to
8314 add a package to the distribution with as little work as
8315 possible---a legitimate demand. The command knows of a few
8316 repositories from which it can ``import'' package metadata. The result
8317 is a package definition, or a template thereof, in the format we know
8318 (@pxref{Defining Packages}).
8320 The general syntax is:
8323 guix import @var{importer} @var{options}@dots{}
8326 @var{importer} specifies the source from which to import package
8327 metadata, and @var{options} specifies a package identifier and other
8328 options specific to @var{importer}. Currently, the available
8333 Import metadata for the given GNU package. This provides a template
8334 for the latest version of that GNU package, including the hash of its
8335 source tarball, and its canonical synopsis and description.
8337 Additional information such as the package dependencies and its
8338 license needs to be figured out manually.
8340 For example, the following command returns a package definition for
8344 guix import gnu hello
8347 Specific command-line options are:
8350 @item --key-download=@var{policy}
8351 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
8352 keys when verifying the package signature. @xref{Invoking guix
8353 refresh, @code{--key-download}}.
8358 Import metadata from the @uref{https://pypi.python.org/, Python Package
8359 Index}. Information is taken from the JSON-formatted description
8360 available at @code{pypi.python.org} and usually includes all the relevant
8361 information, including package dependencies. For maximum efficiency, it
8362 is recommended to install the @command{unzip} utility, so that the
8363 importer can unzip Python wheels and gather data from them.
8365 The command below imports metadata for the @code{itsdangerous} Python
8369 guix import pypi itsdangerous
8375 Traverse the dependency graph of the given upstream package recursively
8376 and generate package expressions for all those packages that are not yet
8382 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
8383 is taken from the JSON-formatted description available at
8384 @code{rubygems.org} and includes most relevant information, including
8385 runtime dependencies. There are some caveats, however. The metadata
8386 doesn't distinguish between synopses and descriptions, so the same string
8387 is used for both fields. Additionally, the details of non-Ruby
8388 dependencies required to build native extensions is unavailable and left
8389 as an exercise to the packager.
8391 The command below imports metadata for the @code{rails} Ruby package:
8394 guix import gem rails
8400 Traverse the dependency graph of the given upstream package recursively
8401 and generate package expressions for all those packages that are not yet
8407 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
8408 Information is taken from the JSON-formatted metadata provided through
8409 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
8410 relevant information, such as module dependencies. License information
8411 should be checked closely. If Perl is available in the store, then the
8412 @code{corelist} utility will be used to filter core modules out of the
8413 list of dependencies.
8415 The command command below imports metadata for the @code{Acme::Boolean}
8419 guix import cpan Acme::Boolean
8424 @cindex Bioconductor
8425 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
8426 central repository for the @uref{http://r-project.org, GNU@tie{}R
8427 statistical and graphical environment}.
8429 Information is extracted from the @code{DESCRIPTION} file of the package.
8431 The command command below imports metadata for the @code{Cairo}
8435 guix import cran Cairo
8438 When @code{--recursive} is added, the importer will traverse the
8439 dependency graph of the given upstream package recursively and generate
8440 package expressions for all those packages that are not yet in Guix.
8442 When @code{--archive=bioconductor} is added, metadata is imported from
8443 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
8444 packages for for the analysis and comprehension of high-throughput
8445 genomic data in bioinformatics.
8447 Information is extracted from the @code{DESCRIPTION} file of a package
8448 published on the web interface of the Bioconductor SVN repository.
8450 The command below imports metadata for the @code{GenomicRanges}
8454 guix import cran --archive=bioconductor GenomicRanges
8460 Import metadata from @uref{http://www.ctan.org/, CTAN}, the
8461 comprehensive TeX archive network for TeX packages that are part of the
8462 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
8464 Information about the package is obtained through the XML API provided
8465 by CTAN, while the source code is downloaded from the SVN repository of
8466 the Tex Live project. This is done because the CTAN does not keep
8469 The command command below imports metadata for the @code{fontspec}
8473 guix import texlive fontspec
8476 When @code{--archive=DIRECTORY} is added, the source code is downloaded
8477 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
8478 tree in the TeX Live SVN repository, but from the specified sibling
8479 directory under the same root.
8481 The command below imports metadata for the @code{ifxetex} package from
8482 CTAN while fetching the sources from the directory
8483 @file{texmf/source/generic}:
8486 guix import texlive --archive=generic ifxetex
8490 @cindex JSON, import
8491 Import package metadata from a local JSON file. Consider the following
8492 example package definition in JSON format:
8498 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
8499 "build-system": "gnu",
8500 "home-page": "https://www.gnu.org/software/hello/",
8501 "synopsis": "Hello, GNU world: An example GNU package",
8502 "description": "GNU Hello prints a greeting.",
8503 "license": "GPL-3.0+",
8504 "native-inputs": ["gcc@@6"]
8508 The field names are the same as for the @code{<package>} record
8509 (@xref{Defining Packages}). References to other packages are provided
8510 as JSON lists of quoted package specification strings such as
8511 @code{guile} or @code{guile@@2.0}.
8513 The importer also supports a more explicit source definition using the
8514 common fields for @code{<origin>} records:
8520 "method": "url-fetch",
8521 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
8523 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
8530 The command below reads metadata from the JSON file @code{hello.json}
8531 and outputs a package expression:
8534 guix import json hello.json
8538 Import metadata from a local copy of the source of the
8539 @uref{http://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
8540 relies on the @command{nix-instantiate} command of
8541 @uref{http://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
8542 typically written in a mixture of Nix-language and Bash code. This
8543 command only imports the high-level package structure that is written in
8544 the Nix language. It normally includes all the basic fields of a
8547 When importing a GNU package, the synopsis and descriptions are replaced
8548 by their canonical upstream variant.
8550 Usually, you will first need to do:
8553 export NIX_REMOTE=daemon
8557 so that @command{nix-instantiate} does not try to open the Nix database.
8559 As an example, the command below imports the package definition of
8560 LibreOffice (more precisely, it imports the definition of the package
8561 bound to the @code{libreoffice} top-level attribute):
8564 guix import nix ~/path/to/nixpkgs libreoffice
8569 Import metadata from the Haskell community's central package archive
8570 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
8571 Cabal files and includes all the relevant information, including package
8574 Specific command-line options are:
8579 Read a Cabal file from standard input.
8580 @item --no-test-dependencies
8582 Do not include dependencies required only by the test suites.
8583 @item --cabal-environment=@var{alist}
8584 @itemx -e @var{alist}
8585 @var{alist} is a Scheme alist defining the environment in which the
8586 Cabal conditionals are evaluated. The accepted keys are: @code{os},
8587 @code{arch}, @code{impl} and a string representing the name of a flag.
8588 The value associated with a flag has to be either the symbol
8589 @code{true} or @code{false}. The value associated with other keys
8590 has to conform to the Cabal file format definition. The default value
8591 associated with the keys @code{os}, @code{arch} and @code{impl} is
8592 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
8595 Traverse the dependency graph of the given upstream package recursively
8596 and generate package expressions for all those packages that are not yet
8600 The command below imports metadata for the latest version of the
8601 @code{HTTP} Haskell package without including test dependencies and
8602 specifying the value of the flag @samp{network-uri} as @code{false}:
8605 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
8608 A specific package version may optionally be specified by following the
8609 package name by an at-sign and a version number as in the following example:
8612 guix import hackage mtl@@2.1.3.1
8617 The @code{stackage} importer is a wrapper around the @code{hackage} one.
8618 It takes a package name, looks up the package version included in a
8619 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
8620 release and uses the @code{hackage} importer to retrieve its metadata.
8621 Note that it is up to you to select an LTS release compatible with the
8622 GHC compiler used by Guix.
8624 Specific command-line options are:
8627 @item --no-test-dependencies
8629 Do not include dependencies required only by the test suites.
8630 @item --lts-version=@var{version}
8631 @itemx -l @var{version}
8632 @var{version} is the desired LTS release version. If omitted the latest
8636 Traverse the dependency graph of the given upstream package recursively
8637 and generate package expressions for all those packages that are not yet
8641 The command below imports metadata for the @code{HTTP} Haskell package
8642 included in the LTS Stackage release version 7.18:
8645 guix import stackage --lts-version=7.18 HTTP
8650 Import metadata from an Emacs Lisp Package Archive (ELPA) package
8651 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
8653 Specific command-line options are:
8656 @item --archive=@var{repo}
8657 @itemx -a @var{repo}
8658 @var{repo} identifies the archive repository from which to retrieve the
8659 information. Currently the supported repositories and their identifiers
8663 @uref{http://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
8664 identifier. This is the default.
8666 Packages from @code{elpa.gnu.org} are signed with one of the keys
8667 contained in the GnuPG keyring at
8668 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
8669 @code{emacs} package (@pxref{Package Installation, ELPA package
8670 signatures,, emacs, The GNU Emacs Manual}).
8673 @uref{http://stable.melpa.org/packages, MELPA-Stable}, selected by the
8674 @code{melpa-stable} identifier.
8677 @uref{http://melpa.org/packages, MELPA}, selected by the @code{melpa}
8683 Traverse the dependency graph of the given upstream package recursively
8684 and generate package expressions for all those packages that are not yet
8690 Import metadata from the crates.io Rust package repository
8691 @uref{https://crates.io, crates.io}.
8696 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
8697 repository used by the OCaml community.
8700 The structure of the @command{guix import} code is modular. It would be
8701 useful to have more importers for other package formats, and your help
8702 is welcome here (@pxref{Contributing}).
8704 @node Invoking guix refresh
8705 @section Invoking @command{guix refresh}
8707 @cindex @command {guix refresh}
8708 The primary audience of the @command{guix refresh} command is developers
8709 of the GNU software distribution. By default, it reports any packages
8710 provided by the distribution that are outdated compared to the latest
8711 upstream version, like this:
8715 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
8716 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
8719 Alternately, one can specify packages to consider, in which case a
8720 warning is emitted for packages that lack an updater:
8723 $ guix refresh coreutils guile guile-ssh
8724 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
8725 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
8728 @command{guix refresh} browses the upstream repository of each package and determines
8729 the highest version number of the releases therein. The command
8730 knows how to update specific types of packages: GNU packages, ELPA
8731 packages, etc.---see the documentation for @option{--type} below. There
8732 are many packages, though, for which it lacks a method to determine
8733 whether a new upstream release is available. However, the mechanism is
8734 extensible, so feel free to get in touch with us to add a new method!
8739 Consider the packages specified, and all the packages upon which they depend.
8742 $ guix refresh --recursive coreutils
8743 gnu/packages/acl.scm:35:2: warning: no updater for acl
8744 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
8745 gnu/packages/xml.scm:68:2: warning: no updater for expat
8746 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
8752 Sometimes the upstream name differs from the package name used in Guix,
8753 and @command{guix refresh} needs a little help. Most updaters honor the
8754 @code{upstream-name} property in package definitions, which can be used
8758 (define-public network-manager
8760 (name "network-manager")
8762 (properties '((upstream-name . "NetworkManager")))))
8765 When passed @code{--update}, it modifies distribution source files to
8766 update the version numbers and source tarball hashes of those package
8767 recipes (@pxref{Defining Packages}). This is achieved by downloading
8768 each package's latest source tarball and its associated OpenPGP
8769 signature, authenticating the downloaded tarball against its signature
8770 using @command{gpg}, and finally computing its hash. When the public
8771 key used to sign the tarball is missing from the user's keyring, an
8772 attempt is made to automatically retrieve it from a public key server;
8773 when this is successful, the key is added to the user's keyring; otherwise,
8774 @command{guix refresh} reports an error.
8776 The following options are supported:
8780 @item --expression=@var{expr}
8781 @itemx -e @var{expr}
8782 Consider the package @var{expr} evaluates to.
8784 This is useful to precisely refer to a package, as in this example:
8787 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
8790 This command lists the dependents of the ``final'' libc (essentially all
8795 Update distribution source files (package recipes) in place. This is
8796 usually run from a checkout of the Guix source tree (@pxref{Running
8797 Guix Before It Is Installed}):
8800 $ ./pre-inst-env guix refresh -s non-core -u
8803 @xref{Defining Packages}, for more information on package definitions.
8805 @item --select=[@var{subset}]
8806 @itemx -s @var{subset}
8807 Select all the packages in @var{subset}, one of @code{core} or
8810 The @code{core} subset refers to all the packages at the core of the
8811 distribution---i.e., packages that are used to build ``everything
8812 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
8813 changing one of these packages in the distribution entails a rebuild of
8814 all the others. Thus, such updates are an inconvenience to users in
8815 terms of build time or bandwidth used to achieve the upgrade.
8817 The @code{non-core} subset refers to the remaining packages. It is
8818 typically useful in cases where an update of the core packages would be
8821 @item --manifest=@var{file}
8822 @itemx -m @var{file}
8823 Select all the packages from the manifest in @var{file}. This is useful to
8824 check if any packages of the user manifest can be updated.
8826 @item --type=@var{updater}
8827 @itemx -t @var{updater}
8828 Select only packages handled by @var{updater} (may be a comma-separated
8829 list of updaters). Currently, @var{updater} may be one of:
8833 the updater for GNU packages;
8835 the updater for GNOME packages;
8837 the updater for KDE packages;
8839 the updater for X.org packages;
8841 the updater for packages hosted on kernel.org;
8843 the updater for @uref{http://elpa.gnu.org/, ELPA} packages;
8845 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
8847 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
8849 the updater for @uref{http://www.cpan.org/, CPAN} packages;
8851 the updater for @uref{https://pypi.python.org, PyPI} packages.
8853 the updater for @uref{https://rubygems.org, RubyGems} packages.
8855 the updater for @uref{https://github.com, GitHub} packages.
8857 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
8859 the updater for @uref{https://www.stackage.org, Stackage} packages.
8861 the updater for @uref{https://crates.io, Crates} packages.
8863 the updater for @uref{https://launchpad.net, Launchpad} packages.
8866 For instance, the following command only checks for updates of Emacs
8867 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
8870 $ guix refresh --type=elpa,cran
8871 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
8872 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
8877 In addition, @command{guix refresh} can be passed one or more package
8878 names, as in this example:
8881 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
8885 The command above specifically updates the @code{emacs} and
8886 @code{idutils} packages. The @code{--select} option would have no
8887 effect in this case.
8889 When considering whether to upgrade a package, it is sometimes
8890 convenient to know which packages would be affected by the upgrade and
8891 should be checked for compatibility. For this the following option may
8892 be used when passing @command{guix refresh} one or more package names:
8896 @item --list-updaters
8898 List available updaters and exit (see @option{--type} above.)
8900 For each updater, display the fraction of packages it covers; at the
8901 end, display the fraction of packages covered by all these updaters.
8903 @item --list-dependent
8905 List top-level dependent packages that would need to be rebuilt as a
8906 result of upgrading one or more packages.
8908 @xref{Invoking guix graph, the @code{reverse-package} type of
8909 @command{guix graph}}, for information on how to visualize the list of
8910 dependents of a package.
8914 Be aware that the @code{--list-dependent} option only
8915 @emph{approximates} the rebuilds that would be required as a result of
8916 an upgrade. More rebuilds might be required under some circumstances.
8919 $ guix refresh --list-dependent flex
8920 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
8921 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
8924 The command above lists a set of packages that could be built to check
8925 for compatibility with an upgraded @code{flex} package.
8929 @item --list-transitive
8930 List all the packages which one or more packages depend upon.
8933 $ guix refresh --list-transitive flex
8934 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
8935 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{}
8940 The command above lists a set of packages which, when changed, would cause
8941 @code{flex} to be rebuilt.
8943 The following options can be used to customize GnuPG operation:
8947 @item --gpg=@var{command}
8948 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
8949 for in @code{$PATH}.
8951 @item --keyring=@var{file}
8952 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
8953 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
8954 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
8955 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
8956 information on a tool to manipulate keybox files).
8958 When this option is omitted, @command{guix refresh} uses
8959 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
8960 signing keys. OpenPGP signatures are checked against keys from this keyring;
8961 missing keys are downloaded to this keyring as well (see
8962 @option{--key-download} below.)
8964 You can export keys from your default GPG keyring into a keybox file using
8965 commands like this one:
8968 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
8971 Likewise, you can fetch keys to a specific keybox file like this:
8974 gpg --no-default-keyring --keyring mykeyring.kbx \
8975 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
8978 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
8979 Privacy Guard}, for more information on GPG's @option{--keyring} option.
8981 @item --key-download=@var{policy}
8982 Handle missing OpenPGP keys according to @var{policy}, which may be one
8987 Always download missing OpenPGP keys from the key server, and add them
8988 to the user's GnuPG keyring.
8991 Never try to download missing OpenPGP keys. Instead just bail out.
8994 When a package signed with an unknown OpenPGP key is encountered, ask
8995 the user whether to download it or not. This is the default behavior.
8998 @item --key-server=@var{host}
8999 Use @var{host} as the OpenPGP key server when importing a public key.
9003 The @code{github} updater uses the
9004 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9005 releases. When used repeatedly e.g.@: when refreshing all packages,
9006 GitHub will eventually refuse to answer any further API requests. By
9007 default 60 API requests per hour are allowed, and a full refresh on all
9008 GitHub packages in Guix requires more than this. Authentication with
9009 GitHub through the use of an API token alleviates these limits. To use
9010 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9011 token procured from @uref{https://github.com/settings/tokens} or
9015 @node Invoking guix lint
9016 @section Invoking @command{guix lint}
9018 @cindex @command{guix lint}
9019 @cindex package, checking for errors
9020 The @command{guix lint} command is meant to help package developers avoid
9021 common errors and use a consistent style. It runs a number of checks on
9022 a given set of packages in order to find common mistakes in their
9023 definitions. Available @dfn{checkers} include (see
9024 @code{--list-checkers} for a complete list):
9029 Validate certain typographical and stylistic rules about package
9030 descriptions and synopses.
9032 @item inputs-should-be-native
9033 Identify inputs that should most likely be native inputs.
9039 @itemx source-file-name
9040 Probe @code{home-page} and @code{source} URLs and report those that are
9041 invalid. Suggest a @code{mirror://} URL when applicable. If the
9042 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9043 URL. Check that the source file name is meaningful, e.g.@: is not just a
9044 version number or ``git-checkout'', without a declared @code{file-name}
9045 (@pxref{origin Reference}).
9047 @item source-unstable-tarball
9048 Parse the @code{source} URL to determine if a tarball from GitHub is
9049 autogenerated or if it is a release tarball. Unfortunately GitHub's
9050 autogenerated tarballs are sometimes regenerated.
9053 @cindex security vulnerabilities
9054 @cindex CVE, Common Vulnerabilities and Exposures
9055 Report known vulnerabilities found in the Common Vulnerabilities and
9056 Exposures (CVE) databases of the current and past year
9057 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
9060 To view information about a particular vulnerability, visit pages such as:
9064 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9066 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9070 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9071 @code{CVE-2015-7554}.
9073 Package developers can specify in package recipes the
9074 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
9075 name and version of the package when they differ from the name or version
9076 that Guix uses, as in this example:
9082 ;; CPE calls this package "grub2".
9083 (properties '((cpe-name . "grub2")
9084 (cpe-version . "2.3")))
9087 @c See <http://www.openwall.com/lists/oss-security/2017/03/15/3>.
9088 Some entries in the CVE database do not specify which version of a
9089 package they apply to, and would thus ``stick around'' forever. Package
9090 developers who found CVE alerts and verified they can be ignored can
9091 declare them as in this example:
9097 ;; These CVEs no longer apply and can be safely ignored.
9098 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9101 "CVE-2011-5244")))))
9105 Warn about obvious source code formatting issues: trailing white space,
9106 use of tabulations, etc.
9109 The general syntax is:
9112 guix lint @var{options} @var{package}@dots{}
9115 If no package is given on the command line, then all packages are checked.
9116 The @var{options} may be zero or more of the following:
9119 @item --list-checkers
9121 List and describe all the available checkers that will be run on packages
9126 Only enable the checkers specified in a comma-separated list using the
9127 names returned by @code{--list-checkers}.
9131 @node Invoking guix size
9132 @section Invoking @command{guix size}
9135 @cindex package size
9137 @cindex @command{guix size}
9138 The @command{guix size} command helps package developers profile the
9139 disk usage of packages. It is easy to overlook the impact of an
9140 additional dependency added to a package, or the impact of using a
9141 single output for a package that could easily be split (@pxref{Packages
9142 with Multiple Outputs}). Such are the typical issues that
9143 @command{guix size} can highlight.
9145 The command can be passed one or more package specifications
9146 such as @code{gcc@@4.8}
9147 or @code{guile:debug}, or a file name in the store. Consider this
9151 $ guix size coreutils
9152 store item total self
9153 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9154 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9155 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9156 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9157 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9158 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9159 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9160 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9165 The store items listed here constitute the @dfn{transitive closure} of
9166 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9167 would be returned by:
9170 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9173 Here the output shows three columns next to store items. The first column,
9174 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9175 the store item---that is, its own size plus the size of all its
9176 dependencies. The next column, labeled ``self'', shows the size of the
9177 item itself. The last column shows the ratio of the size of the item
9178 itself to the space occupied by all the items listed here.
9180 In this example, we see that the closure of Coreutils weighs in at
9181 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9182 libraries. (That libc and GCC's libraries represent a large fraction of
9183 the closure is not a problem @i{per se} because they are always available
9184 on the system anyway.)
9186 When the package(s) passed to @command{guix size} are available in the
9187 store@footnote{More precisely, @command{guix size} looks for the
9188 @emph{ungrafted} variant of the given package(s), as returned by
9189 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9190 for information on grafts.}, @command{guix size} queries the daemon to determine its
9191 dependencies, and measures its size in the store, similar to @command{du
9192 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9195 When the given packages are @emph{not} in the store, @command{guix size}
9196 reports information based on the available substitutes
9197 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9198 store items that are not even on disk, only available remotely.
9200 You can also specify several package names:
9203 $ guix size coreutils grep sed bash
9204 store item total self
9205 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9206 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9207 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9208 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
9214 In this example we see that the combination of the four packages takes
9215 102.3@tie{}MiB in total, which is much less than the sum of each closure
9216 since they have a lot of dependencies in common.
9218 The available options are:
9222 @item --substitute-urls=@var{urls}
9223 Use substitute information from @var{urls}.
9224 @xref{client-substitute-urls, the same option for @code{guix build}}.
9226 @item --sort=@var{key}
9227 Sort lines according to @var{key}, one of the following options:
9231 the size of each item (the default);
9233 the total size of the item's closure.
9236 @item --map-file=@var{file}
9237 Write a graphical map of disk usage in PNG format to @var{file}.
9239 For the example above, the map looks like this:
9241 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
9242 produced by @command{guix size}}
9244 This option requires that
9245 @uref{http://wingolog.org/software/guile-charting/, Guile-Charting} be
9246 installed and visible in Guile's module search path. When that is not
9247 the case, @command{guix size} fails as it tries to load it.
9249 @item --system=@var{system}
9250 @itemx -s @var{system}
9251 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
9255 @node Invoking guix graph
9256 @section Invoking @command{guix graph}
9259 @cindex @command{guix graph}
9260 @cindex package dependencies
9261 Packages and their dependencies form a @dfn{graph}, specifically a
9262 directed acyclic graph (DAG). It can quickly become difficult to have a
9263 mental model of the package DAG, so the @command{guix graph} command
9264 provides a visual representation of the DAG. By default,
9265 @command{guix graph} emits a DAG representation in the input format of
9266 @uref{http://www.graphviz.org/, Graphviz}, so its output can be passed
9267 directly to the @command{dot} command of Graphviz. It can also emit an
9268 HTML page with embedded JavaScript code to display a ``chord diagram''
9269 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
9270 emit Cypher queries to construct a graph in a graph database supporting
9271 the @uref{http://www.opencypher.org/, openCypher} query language.
9272 The general syntax is:
9275 guix graph @var{options} @var{package}@dots{}
9278 For example, the following command generates a PDF file representing the
9279 package DAG for the GNU@tie{}Core Utilities, showing its build-time
9283 guix graph coreutils | dot -Tpdf > dag.pdf
9286 The output looks like this:
9288 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
9290 Nice little graph, no?
9292 But there is more than one graph! The one above is concise: it is the
9293 graph of package objects, omitting implicit inputs such as GCC, libc,
9294 grep, etc. It is often useful to have such a concise graph, but
9295 sometimes one may want to see more details. @command{guix graph} supports
9296 several types of graphs, allowing you to choose the level of detail:
9300 This is the default type used in the example above. It shows the DAG of
9301 package objects, excluding implicit dependencies. It is concise, but
9302 filters out many details.
9304 @item reverse-package
9305 This shows the @emph{reverse} DAG of packages. For example:
9308 guix graph --type=reverse-package ocaml
9311 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
9312 you are also interested in cases where OCaml is an implicit dependency, see
9313 @code{reverse-bag} below.)
9315 Note that for core packages this can yield huge graphs. If all you want
9316 is to know the number of packages that depend on a given package, use
9317 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
9318 @option{--list-dependent}}).
9321 This is the package DAG, @emph{including} implicit inputs.
9323 For instance, the following command:
9326 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
9329 ...@: yields this bigger graph:
9331 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
9333 At the bottom of the graph, we see all the implicit inputs of
9334 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
9336 Now, note that the dependencies of these implicit inputs---that is, the
9337 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
9338 here, for conciseness.
9341 Similar to @code{bag-emerged}, but this time including all the bootstrap
9344 @item bag-with-origins
9345 Similar to @code{bag}, but also showing origins and their dependencies.
9348 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
9349 it also takes implicit dependencies into account. For example:
9352 guix graph -t reverse-bag dune
9356 ...@: yields the graph of all packages that depend on Dune, directly or
9357 indirectly. Since Dune is an @emph{implicit} dependency of many packages
9358 @i{via} @code{dune-build-system}, this shows a large number of packages,
9359 whereas @code{reverse-package} would show very few if any.
9362 This is the most detailed representation: It shows the DAG of
9363 derivations (@pxref{Derivations}) and plain store items. Compared to
9364 the above representation, many additional nodes are visible, including
9365 build scripts, patches, Guile modules, etc.
9367 For this type of graph, it is also possible to pass a @file{.drv} file
9368 name instead of a package name, as in:
9371 guix graph -t derivation `guix system build -d my-config.scm`
9375 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
9376 For example, the following command shows the graph for the package
9377 module that defines the @code{guile} package:
9380 guix graph -t module guile | dot -Tpdf > module-graph.pdf
9384 All the types above correspond to @emph{build-time dependencies}. The
9385 following graph type represents the @emph{run-time dependencies}:
9389 This is the graph of @dfn{references} of a package output, as returned
9390 by @command{guix gc --references} (@pxref{Invoking guix gc}).
9392 If the given package output is not available in the store, @command{guix
9393 graph} attempts to obtain dependency information from substitutes.
9395 Here you can also pass a store file name instead of a package name. For
9396 example, the command below produces the reference graph of your profile
9397 (which can be big!):
9400 guix graph -t references `readlink -f ~/.guix-profile`
9404 This is the graph of the @dfn{referrers} of a store item, as returned by
9405 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
9407 This relies exclusively on local information from your store. For
9408 instance, let us suppose that the current Inkscape is available in 10
9409 profiles on your machine; @command{guix graph -t referrers inkscape}
9410 will show a graph rooted at Inkscape and with those 10 profiles linked
9413 It can help determine what is preventing a store item from being garbage
9418 The available options are the following:
9421 @item --type=@var{type}
9422 @itemx -t @var{type}
9423 Produce a graph output of @var{type}, where @var{type} must be one of
9424 the values listed above.
9427 List the supported graph types.
9429 @item --backend=@var{backend}
9430 @itemx -b @var{backend}
9431 Produce a graph using the selected @var{backend}.
9433 @item --list-backends
9434 List the supported graph backends.
9436 Currently, the available backends are Graphviz and d3.js.
9438 @item --expression=@var{expr}
9439 @itemx -e @var{expr}
9440 Consider the package @var{expr} evaluates to.
9442 This is useful to precisely refer to a package, as in this example:
9445 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
9448 @item --system=@var{system}
9449 @itemx -s @var{system}
9450 Display the graph for @var{system}---e.g., @code{i686-linux}.
9452 The package dependency graph is largely architecture-independent, but there
9453 are some architecture-dependent bits that this option allows you to visualize.
9458 @node Invoking guix publish
9459 @section Invoking @command{guix publish}
9461 @cindex @command{guix publish}
9462 The purpose of @command{guix publish} is to enable users to easily share
9463 their store with others, who can then use it as a substitute server
9464 (@pxref{Substitutes}).
9466 When @command{guix publish} runs, it spawns an HTTP server which allows
9467 anyone with network access to obtain substitutes from it. This means
9468 that any machine running Guix can also act as if it were a build farm,
9469 since the HTTP interface is compatible with Hydra, the software behind
9470 the @code{@value{SUBSTITUTE-SERVER}} build farm.
9472 For security, each substitute is signed, allowing recipients to check
9473 their authenticity and integrity (@pxref{Substitutes}). Because
9474 @command{guix publish} uses the signing key of the system, which is only
9475 readable by the system administrator, it must be started as root; the
9476 @code{--user} option makes it drop root privileges early on.
9478 The signing key pair must be generated before @command{guix publish} is
9479 launched, using @command{guix archive --generate-key} (@pxref{Invoking
9482 The general syntax is:
9485 guix publish @var{options}@dots{}
9488 Running @command{guix publish} without any additional arguments will
9489 spawn an HTTP server on port 8080:
9495 Once a publishing server has been authorized (@pxref{Invoking guix
9496 archive}), the daemon may download substitutes from it:
9499 guix-daemon --substitute-urls=http://example.org:8080
9502 By default, @command{guix publish} compresses archives on the fly as it
9503 serves them. This ``on-the-fly'' mode is convenient in that it requires
9504 no setup and is immediately available. However, when serving lots of
9505 clients, we recommend using the @option{--cache} option, which enables
9506 caching of the archives before they are sent to clients---see below for
9507 details. The @command{guix weather} command provides a handy way to
9508 check what a server provides (@pxref{Invoking guix weather}).
9510 As a bonus, @command{guix publish} also serves as a content-addressed
9511 mirror for source files referenced in @code{origin} records
9512 (@pxref{origin Reference}). For instance, assuming @command{guix
9513 publish} is running on @code{example.org}, the following URL returns the
9514 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
9515 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
9518 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
9521 Obviously, these URLs only work for files that are in the store; in
9522 other cases, they return 404 (``Not Found'').
9524 @cindex build logs, publication
9525 Build logs are available from @code{/log} URLs like:
9528 http://example.org/log/gwspk@dots{}-guile-2.2.3
9532 When @command{guix-daemon} is configured to save compressed build logs,
9533 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
9534 URLs return the compressed log as-is, with an appropriate
9535 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
9536 running @command{guix-daemon} with @code{--log-compression=gzip} since
9537 Web browsers can automatically decompress it, which is not the case with
9540 The following options are available:
9543 @item --port=@var{port}
9544 @itemx -p @var{port}
9545 Listen for HTTP requests on @var{port}.
9547 @item --listen=@var{host}
9548 Listen on the network interface for @var{host}. The default is to
9549 accept connections from any interface.
9551 @item --user=@var{user}
9552 @itemx -u @var{user}
9553 Change privileges to @var{user} as soon as possible---i.e., once the
9554 server socket is open and the signing key has been read.
9556 @item --compression[=@var{level}]
9557 @itemx -C [@var{level}]
9558 Compress data using the given @var{level}. When @var{level} is zero,
9559 disable compression. The range 1 to 9 corresponds to different gzip
9560 compression levels: 1 is the fastest, and 9 is the best (CPU-intensive).
9563 Unless @option{--cache} is used, compression occurs on the fly and
9564 the compressed streams are not
9565 cached. Thus, to reduce load on the machine that runs @command{guix
9566 publish}, it may be a good idea to choose a low compression level, to
9567 run @command{guix publish} behind a caching proxy, or to use
9568 @option{--cache}. Using @option{--cache} has the advantage that it
9569 allows @command{guix publish} to add @code{Content-Length} HTTP header
9572 @item --cache=@var{directory}
9573 @itemx -c @var{directory}
9574 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
9575 and only serve archives that are in cache.
9577 When this option is omitted, archives and meta-data are created
9578 on-the-fly. This can reduce the available bandwidth, especially when
9579 compression is enabled, since this may become CPU-bound. Another
9580 drawback of the default mode is that the length of archives is not known
9581 in advance, so @command{guix publish} does not add a
9582 @code{Content-Length} HTTP header to its responses, which in turn
9583 prevents clients from knowing the amount of data being downloaded.
9585 Conversely, when @option{--cache} is used, the first request for a store
9586 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
9587 background process to @dfn{bake} the archive---computing its
9588 @code{.narinfo} and compressing the archive, if needed. Once the
9589 archive is cached in @var{directory}, subsequent requests succeed and
9590 are served directly from the cache, which guarantees that clients get
9591 the best possible bandwidth.
9593 The ``baking'' process is performed by worker threads. By default, one
9594 thread per CPU core is created, but this can be customized. See
9595 @option{--workers} below.
9597 When @option{--ttl} is used, cached entries are automatically deleted
9598 when they have expired.
9600 @item --workers=@var{N}
9601 When @option{--cache} is used, request the allocation of @var{N} worker
9602 threads to ``bake'' archives.
9604 @item --ttl=@var{ttl}
9605 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
9606 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
9607 days, @code{1m} means 1 month, and so on.
9609 This allows the user's Guix to keep substitute information in cache for
9610 @var{ttl}. However, note that @code{guix publish} does not itself
9611 guarantee that the store items it provides will indeed remain available
9612 for as long as @var{ttl}.
9614 Additionally, when @option{--cache} is used, cached entries that have
9615 not been accessed for @var{ttl} and that no longer have a corresponding
9616 item in the store, may be deleted.
9618 @item --nar-path=@var{path}
9619 Use @var{path} as the prefix for the URLs of ``nar'' files
9620 (@pxref{Invoking guix archive, normalized archives}).
9622 By default, nars are served at a URL such as
9623 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
9624 change the @code{/nar} part to @var{path}.
9626 @item --public-key=@var{file}
9627 @itemx --private-key=@var{file}
9628 Use the specific @var{file}s as the public/private key pair used to sign
9629 the store items being published.
9631 The files must correspond to the same key pair (the private key is used
9632 for signing and the public key is merely advertised in the signature
9633 metadata). They must contain keys in the canonical s-expression format
9634 as produced by @command{guix archive --generate-key} (@pxref{Invoking
9635 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
9636 @file{/etc/guix/signing-key.sec} are used.
9638 @item --repl[=@var{port}]
9639 @itemx -r [@var{port}]
9640 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
9641 Reference Manual}) on @var{port} (37146 by default). This is used
9642 primarily for debugging a running @command{guix publish} server.
9645 Enabling @command{guix publish} on Guix System is a one-liner: just
9646 instantiate a @code{guix-publish-service-type} service in the @code{services} field
9647 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
9648 @code{guix-publish-service-type}}).
9650 If you are instead running Guix on a ``foreign distro'', follow these
9655 If your host distro uses the systemd init system:
9658 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
9659 /etc/systemd/system/
9660 # systemctl start guix-publish && systemctl enable guix-publish
9664 If your host distro uses the Upstart init system:
9667 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
9668 # start guix-publish
9672 Otherwise, proceed similarly with your distro's init system.
9675 @node Invoking guix challenge
9676 @section Invoking @command{guix challenge}
9678 @cindex reproducible builds
9679 @cindex verifiable builds
9680 @cindex @command{guix challenge}
9682 Do the binaries provided by this server really correspond to the source
9683 code it claims to build? Is a package build process deterministic?
9684 These are the questions the @command{guix challenge} command attempts to
9687 The former is obviously an important question: Before using a substitute
9688 server (@pxref{Substitutes}), one had better @emph{verify} that it
9689 provides the right binaries, and thus @emph{challenge} it. The latter
9690 is what enables the former: If package builds are deterministic, then
9691 independent builds of the package should yield the exact same result,
9692 bit for bit; if a server provides a binary different from the one
9693 obtained locally, it may be either corrupt or malicious.
9695 We know that the hash that shows up in @file{/gnu/store} file names is
9696 the hash of all the inputs of the process that built the file or
9697 directory---compilers, libraries, build scripts,
9698 etc. (@pxref{Introduction}). Assuming deterministic build processes,
9699 one store file name should map to exactly one build output.
9700 @command{guix challenge} checks whether there is, indeed, a single
9701 mapping by comparing the build outputs of several independent builds of
9702 any given store item.
9704 The command output looks like this:
9707 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
9708 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
9709 updating list of substitutes from 'https://guix.example.org'... 100.0%
9710 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
9711 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9712 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9713 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
9714 /gnu/store/@dots{}-git-2.5.0 contents differ:
9715 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
9716 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
9717 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
9718 /gnu/store/@dots{}-pius-2.1.1 contents differ:
9719 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9720 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9721 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
9725 6,406 store items were analyzed:
9726 - 4,749 (74.1%) were identical
9727 - 525 (8.2%) differed
9728 - 1,132 (17.7%) were inconclusive
9732 In this example, @command{guix challenge} first scans the store to
9733 determine the set of locally-built derivations---as opposed to store
9734 items that were downloaded from a substitute server---and then queries
9735 all the substitute servers. It then reports those store items for which
9736 the servers obtained a result different from the local build.
9738 @cindex non-determinism, in package builds
9739 As an example, @code{guix.example.org} always gets a different answer.
9740 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
9741 case of Git. This might indicate that the build process of Git is
9742 non-deterministic, meaning that its output varies as a function of
9743 various things that Guix does not fully control, in spite of building
9744 packages in isolated environments (@pxref{Features}). Most common
9745 sources of non-determinism include the addition of timestamps in build
9746 results, the inclusion of random numbers, and directory listings sorted
9747 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
9750 To find out what is wrong with this Git binary, we can do something along
9751 these lines (@pxref{Invoking guix archive}):
9754 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
9755 | guix archive -x /tmp/git
9756 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
9759 This command shows the difference between the files resulting from the
9760 local build, and the files resulting from the build on
9761 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
9762 diffutils, Comparing and Merging Files}). The @command{diff} command
9763 works great for text files. When binary files differ, a better option
9764 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
9765 visualize differences for all kinds of files.
9767 Once you have done that work, you can tell whether the differences are due
9768 to a non-deterministic build process or to a malicious server. We try
9769 hard to remove sources of non-determinism in packages to make it easier
9770 to verify substitutes, but of course, this is a process that
9771 involves not just Guix, but a large part of the free software community.
9772 In the meantime, @command{guix challenge} is one tool to help address
9775 If you are writing packages for Guix, you are encouraged to check
9776 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
9777 same build result as you did with:
9780 $ guix challenge @var{package}
9784 where @var{package} is a package specification such as
9785 @code{guile@@2.0} or @code{glibc:debug}.
9787 The general syntax is:
9790 guix challenge @var{options} [@var{packages}@dots{}]
9793 When a difference is found between the hash of a locally-built item and
9794 that of a server-provided substitute, or among substitutes provided by
9795 different servers, the command displays it as in the example above and
9796 its exit code is 2 (other non-zero exit codes denote other kinds of
9799 The one option that matters is:
9803 @item --substitute-urls=@var{urls}
9804 Consider @var{urls} the whitespace-separated list of substitute source
9809 Show details about matches (identical contents) in addition to
9810 information about mismatches.
9814 @node Invoking guix copy
9815 @section Invoking @command{guix copy}
9817 @cindex copy, of store items, over SSH
9818 @cindex SSH, copy of store items
9819 @cindex sharing store items across machines
9820 @cindex transferring store items across machines
9821 The @command{guix copy} command copies items from the store of one
9822 machine to that of another machine over a secure shell (SSH)
9823 connection@footnote{This command is available only when Guile-SSH was
9824 found. @xref{Requirements}, for details.}. For example, the following
9825 command copies the @code{coreutils} package, the user's profile, and all
9826 their dependencies over to @var{host}, logged in as @var{user}:
9829 guix copy --to=@var{user}@@@var{host} \
9830 coreutils `readlink -f ~/.guix-profile`
9833 If some of the items to be copied are already present on @var{host},
9834 they are not actually sent.
9836 The command below retrieves @code{libreoffice} and @code{gimp} from
9837 @var{host}, assuming they are available there:
9840 guix copy --from=@var{host} libreoffice gimp
9843 The SSH connection is established using the Guile-SSH client, which is
9844 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
9845 @file{~/.ssh/config}, and uses the SSH agent for authentication.
9847 The key used to sign items that are sent must be accepted by the remote
9848 machine. Likewise, the key used by the remote machine to sign items you
9849 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
9850 own daemon. @xref{Invoking guix archive}, for more information about
9851 store item authentication.
9853 The general syntax is:
9856 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
9859 You must always specify one of the following options:
9862 @item --to=@var{spec}
9863 @itemx --from=@var{spec}
9864 Specify the host to send to or receive from. @var{spec} must be an SSH
9865 spec such as @code{example.org}, @code{charlie@@example.org}, or
9866 @code{charlie@@example.org:2222}.
9869 The @var{items} can be either package names, such as @code{gimp}, or
9870 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
9872 When specifying the name of a package to send, it is first built if
9873 needed, unless @option{--dry-run} was specified. Common build options
9874 are supported (@pxref{Common Build Options}).
9877 @node Invoking guix container
9878 @section Invoking @command{guix container}
9880 @cindex @command{guix container}
9882 As of version @value{VERSION}, this tool is experimental. The interface
9883 is subject to radical change in the future.
9886 The purpose of @command{guix container} is to manipulate processes
9887 running within an isolated environment, commonly known as a
9888 ``container'', typically created by the @command{guix environment}
9889 (@pxref{Invoking guix environment}) and @command{guix system container}
9890 (@pxref{Invoking guix system}) commands.
9892 The general syntax is:
9895 guix container @var{action} @var{options}@dots{}
9898 @var{action} specifies the operation to perform with a container, and
9899 @var{options} specifies the context-specific arguments for the action.
9901 The following actions are available:
9905 Execute a command within the context of a running container.
9910 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
9913 @var{pid} specifies the process ID of the running container.
9914 @var{program} specifies an executable file name within the root file
9915 system of the container. @var{arguments} are the additional options that
9916 will be passed to @var{program}.
9918 The following command launches an interactive login shell inside a
9919 Guix system container, started by @command{guix system container}, and whose
9923 guix container exec 9001 /run/current-system/profile/bin/bash --login
9926 Note that the @var{pid} cannot be the parent process of a container. It
9927 must be PID 1 of the container or one of its child processes.
9931 @node Invoking guix weather
9932 @section Invoking @command{guix weather}
9934 Occasionally you're grumpy because substitutes are lacking and you end
9935 up building packages by yourself (@pxref{Substitutes}). The
9936 @command{guix weather} command reports on substitute availability on the
9937 specified servers so you can have an idea of whether you'll be grumpy
9938 today. It can sometimes be useful info as a user, but it is primarily
9939 useful to people running @command{guix publish} (@pxref{Invoking guix
9942 @cindex statistics, for substitutes
9943 @cindex availability of substitutes
9944 @cindex substitute availability
9945 @cindex weather, substitute availability
9946 Here's a sample run:
9949 $ guix weather --substitute-urls=https://guix.example.org
9950 computing 5,872 package derivations for x86_64-linux...
9951 looking for 6,128 store items on https://guix.example.org..
9952 updating list of substitutes from 'https://guix.example.org'... 100.0%
9953 https://guix.example.org
9954 43.4% substitutes available (2,658 out of 6,128)
9955 7,032.5 MiB of nars (compressed)
9956 19,824.2 MiB on disk (uncompressed)
9957 0.030 seconds per request (182.9 seconds in total)
9958 33.5 requests per second
9960 9.8% (342 out of 3,470) of the missing items are queued
9962 x86_64-linux: 518 (59.7%)
9963 i686-linux: 221 (25.5%)
9964 aarch64-linux: 128 (14.8%)
9965 build rate: 23.41 builds per hour
9966 x86_64-linux: 11.16 builds per hour
9967 i686-linux: 6.03 builds per hour
9968 aarch64-linux: 6.41 builds per hour
9971 @cindex continuous integration, statistics
9972 As you can see, it reports the fraction of all the packages for which
9973 substitutes are available on the server---regardless of whether
9974 substitutes are enabled, and regardless of whether this server's signing
9975 key is authorized. It also reports the size of the compressed archives
9976 (``nars'') provided by the server, the size the corresponding store
9977 items occupy in the store (assuming deduplication is turned off), and
9978 the server's throughput. The second part gives continuous integration
9979 (CI) statistics, if the server supports it. In addition, using the
9980 @option{--coverage} option, @command{guix weather} can list ``important''
9981 package substitutes missing on the server (see below).
9983 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
9984 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
9985 challenge}, it ignores signatures on those substitutes, which is
9986 innocuous since the command only gathers statistics and cannot install
9989 Among other things, it is possible to query specific system types and
9990 specific package sets. The available options are listed below.
9993 @item --substitute-urls=@var{urls}
9994 @var{urls} is the space-separated list of substitute server URLs to
9995 query. When this option is omitted, the default set of substitute
9998 @item --system=@var{system}
9999 @itemx -s @var{system}
10000 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10001 option can be repeated, in which case @command{guix weather} will query
10002 substitutes for several system types.
10004 @item --manifest=@var{file}
10005 Instead of querying substitutes for all the packages, only ask for those
10006 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10007 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10010 @item --coverage[=@var{count}]
10011 @itemx -c [@var{count}]
10012 Report on substitute coverage for packages: list packages with at least
10013 @var{count} dependents (zero by default) for which substitutes are
10014 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10015 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10016 @var{b} usually lacks substitutes as well. The result looks like this:
10019 $ guix weather --substitute-urls=https://ci.guix.info -c 10
10020 computing 8,983 package derivations for x86_64-linux...
10021 looking for 9,343 store items on https://ci.guix.info...
10022 updating substitutes from 'https://ci.guix.info'... 100.0%
10023 https://ci.guix.info
10024 64.7% substitutes available (6,047 out of 9,343)
10026 2502 packages are missing from 'https://ci.guix.info' for 'x86_64-linux', among which:
10027 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10028 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10029 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10033 What this example shows is that @code{kcoreaddons} and presumably the 58
10034 packages that depend on it have no substitutes at @code{ci.guix.info};
10035 likewise for @code{qgpgme} and the 46 packages that depend on it.
10037 If you are a Guix developer, or if you are taking care of this build farm,
10038 you'll probably want to have a closer look at these packages: they may simply
10042 @node Invoking guix processes
10043 @section Invoking @command{guix processes}
10045 The @command{guix processes} command can be useful to developers and system
10046 administrators, especially on multi-user machines and on build farms: it lists
10047 the current sessions (connections to the daemon), as well as information about
10048 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10049 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10050 listed.}. Here's an example of the information it returns:
10053 $ sudo guix processes
10056 ClientCommand: guix environment --ad-hoc python
10060 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10064 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10065 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10066 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10067 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10068 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10069 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10070 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10073 In this example we see that @command{guix-daemon} has three clients:
10074 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10075 integration tool; their process identifier (PID) is given by the
10076 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10077 @command{guix-daemon} sub-process of this particular session.
10079 The @code{LockHeld} fields show which store items are currently locked by this
10080 session, which corresponds to store items being built or substituted (the
10081 @code{LockHeld} field is not displayed when @command{guix processes} is not
10082 running as root.) Last, by looking at the @code{ChildProcess} field, we
10083 understand that these three builds are being offloaded (@pxref{Daemon Offload
10086 The output is in Recutils format so we can use the handy @command{recsel}
10087 command to select sessions of interest (@pxref{Selection Expressions,,,
10088 recutils, GNU recutils manual}). As an example, the command shows the command
10089 line and PID of the client that triggered the build of a Perl package:
10092 $ sudo guix processes | \
10093 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10095 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10099 @node System Configuration
10100 @chapter System Configuration
10102 @cindex system configuration
10103 The Guix System Distribution supports a consistent whole-system configuration
10104 mechanism. By that we mean that all aspects of the global system
10105 configuration---such as the available system services, timezone and
10106 locale settings, user accounts---are declared in a single place. Such
10107 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10109 One of the advantages of putting all the system configuration under the
10110 control of Guix is that it supports transactional system upgrades, and
10111 makes it possible to roll back to a previous system instantiation,
10112 should something go wrong with the new one (@pxref{Features}). Another
10113 advantage is that it makes it easy to replicate the exact same configuration
10114 across different machines, or at different points in time, without
10115 having to resort to additional administration tools layered on top of
10116 the own tools of the system.
10117 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
10119 This section describes this mechanism. First we focus on the system
10120 administrator's viewpoint---explaining how the system is configured and
10121 instantiated. Then we show how this mechanism can be extended, for
10122 instance to support new system services.
10125 * Using the Configuration System:: Customizing your GNU system.
10126 * operating-system Reference:: Detail of operating-system declarations.
10127 * File Systems:: Configuring file system mounts.
10128 * Mapped Devices:: Block device extra processing.
10129 * User Accounts:: Specifying user accounts.
10130 * Locales:: Language and cultural convention settings.
10131 * Services:: Specifying system services.
10132 * Setuid Programs:: Programs running with root privileges.
10133 * X.509 Certificates:: Authenticating HTTPS servers.
10134 * Name Service Switch:: Configuring libc's name service switch.
10135 * Initial RAM Disk:: Linux-Libre bootstrapping.
10136 * Bootloader Configuration:: Configuring the boot loader.
10137 * Invoking guix system:: Instantiating a system configuration.
10138 * Running Guix in a VM:: How to run Guix System in a virtual machine.
10139 * Defining Services:: Adding new service definitions.
10142 @node Using the Configuration System
10143 @section Using the Configuration System
10145 The operating system is configured by providing an
10146 @code{operating-system} declaration in a file that can then be passed to
10147 the @command{guix system} command (@pxref{Invoking guix system}). A
10148 simple setup, with the default system services, the default Linux-Libre
10149 kernel, initial RAM disk, and boot loader looks like this:
10151 @findex operating-system
10153 @include os-config-bare-bones.texi
10156 This example should be self-describing. Some of the fields defined
10157 above, such as @code{host-name} and @code{bootloader}, are mandatory.
10158 Others, such as @code{packages} and @code{services}, can be omitted, in
10159 which case they get a default value.
10161 Below we discuss the effect of some of the most important fields
10162 (@pxref{operating-system Reference}, for details about all the available
10163 fields), and how to @dfn{instantiate} the operating system using
10164 @command{guix system}.
10166 @unnumberedsubsec Bootloader
10168 @cindex legacy boot, on Intel machines
10169 @cindex BIOS boot, on Intel machines
10172 The @code{bootloader} field describes the method that will be used to boot
10173 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
10174 mode, as in the example above. However, more recent machines rely instead on
10175 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
10176 the @code{bootloader} field should contain something along these lines:
10179 (bootloader-configuration
10180 (bootloader grub-efi-bootloader)
10181 (target "/boot/efi"))
10184 @xref{Bootloader Configuration}, for more information on the available
10185 configuration options.
10187 @unnumberedsubsec Globally-Visible Packages
10189 @vindex %base-packages
10190 The @code{packages} field lists packages that will be globally visible
10191 on the system, for all user accounts---i.e., in every user's @code{PATH}
10192 environment variable---in addition to the per-user profiles
10193 (@pxref{Invoking guix package}). The @var{%base-packages} variable
10194 provides all the tools one would expect for basic user and administrator
10195 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
10196 the GNU Zile lightweight text editor, @command{find}, @command{grep},
10197 etc. The example above adds GNU@tie{}Screen to those,
10198 taken from the @code{(gnu packages screen)}
10199 module (@pxref{Package Modules}). The
10200 @code{(list package output)} syntax can be used to add a specific output
10204 (use-modules (gnu packages))
10205 (use-modules (gnu packages dns))
10209 (packages (cons (list bind "utils")
10213 @findex specification->package
10214 Referring to packages by variable name, like @code{bind} above, has
10215 the advantage of being unambiguous; it also allows typos and such to be
10216 diagnosed right away as ``unbound variables''. The downside is that one
10217 needs to know which module defines which package, and to augment the
10218 @code{use-package-modules} line accordingly. To avoid that, one can use
10219 the @code{specification->package} procedure of the @code{(gnu packages)}
10220 module, which returns the best package for a given name or name and
10224 (use-modules (gnu packages))
10228 (packages (append (map specification->package
10229 '("tcpdump" "htop" "gnupg@@2.0"))
10233 @unnumberedsubsec System Services
10236 @vindex %base-services
10237 The @code{services} field lists @dfn{system services} to be made
10238 available when the system starts (@pxref{Services}).
10239 The @code{operating-system} declaration above specifies that, in
10240 addition to the basic services, we want the OpenSSH secure shell
10241 daemon listening on port 2222 (@pxref{Networking Services,
10242 @code{openssh-service-type}}). Under the hood,
10243 @code{openssh-service-type} arranges so that @command{sshd} is started with the
10244 right command-line options, possibly with supporting configuration files
10245 generated as needed (@pxref{Defining Services}).
10247 @cindex customization, of services
10248 @findex modify-services
10249 Occasionally, instead of using the base services as is, you will want to
10250 customize them. To do this, use @code{modify-services} (@pxref{Service
10251 Reference, @code{modify-services}}) to modify the list.
10253 For example, suppose you want to modify @code{guix-daemon} and Mingetty
10254 (the console log-in) in the @var{%base-services} list (@pxref{Base
10255 Services, @code{%base-services}}). To do that, you can write the
10256 following in your operating system declaration:
10259 (define %my-services
10260 ;; My very own list of services.
10261 (modify-services %base-services
10262 (guix-service-type config =>
10263 (guix-configuration
10265 (use-substitutes? #f)
10266 (extra-options '("--gc-keep-derivations"))))
10267 (mingetty-service-type config =>
10268 (mingetty-configuration
10269 (inherit config)))))
10273 (services %my-services))
10276 This changes the configuration---i.e., the service parameters---of the
10277 @code{guix-service-type} instance, and that of all the
10278 @code{mingetty-service-type} instances in the @var{%base-services} list.
10279 Observe how this is accomplished: first, we arrange for the original
10280 configuration to be bound to the identifier @code{config} in the
10281 @var{body}, and then we write the @var{body} so that it evaluates to the
10282 desired configuration. In particular, notice how we use @code{inherit}
10283 to create a new configuration which has the same values as the old
10284 configuration, but with a few modifications.
10286 @cindex encrypted disk
10287 The configuration for a typical ``desktop'' usage, with an encrypted
10288 root partition, the X11 display
10289 server, GNOME and Xfce (users can choose which of these desktop
10290 environments to use at the log-in screen by pressing @kbd{F1}), network
10291 management, power management, and more, would look like this:
10294 @include os-config-desktop.texi
10297 A graphical system with a choice of lightweight window managers
10298 instead of full-blown desktop environments would look like this:
10301 @include os-config-lightweight-desktop.texi
10304 This example refers to the @file{/boot/efi} file system by its UUID,
10305 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
10306 as returned by the @command{blkid} command.
10308 @xref{Desktop Services}, for the exact list of services provided by
10309 @var{%desktop-services}. @xref{X.509 Certificates}, for background
10310 information about the @code{nss-certs} package that is used here.
10312 Again, @var{%desktop-services} is just a list of service objects. If
10313 you want to remove services from there, you can do so using the
10314 procedures for list filtering (@pxref{SRFI-1 Filtering and
10315 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
10316 following expression returns a list that contains all the services in
10317 @var{%desktop-services} minus the Avahi service:
10320 (remove (lambda (service)
10321 (eq? (service-kind service) avahi-service-type))
10325 @unnumberedsubsec Instantiating the System
10327 Assuming the @code{operating-system} declaration
10328 is stored in the @file{my-system-config.scm}
10329 file, the @command{guix system reconfigure my-system-config.scm} command
10330 instantiates that configuration, and makes it the default GRUB boot
10331 entry (@pxref{Invoking guix system}).
10333 The normal way to change the system configuration is by updating this
10334 file and re-running @command{guix system reconfigure}. One should never
10335 have to touch files in @file{/etc} or to run commands that modify the
10336 system state such as @command{useradd} or @command{grub-install}. In
10337 fact, you must avoid that since that would not only void your warranty
10338 but also prevent you from rolling back to previous versions of your
10339 system, should you ever need to.
10341 @cindex roll-back, of the operating system
10342 Speaking of roll-back, each time you run @command{guix system
10343 reconfigure}, a new @dfn{generation} of the system is created---without
10344 modifying or deleting previous generations. Old system generations get
10345 an entry in the bootloader boot menu, allowing you to boot them in case
10346 something went wrong with the latest generation. Reassuring, no? The
10347 @command{guix system list-generations} command lists the system
10348 generations available on disk. It is also possible to roll back the
10349 system via the commands @command{guix system roll-back} and
10350 @command{guix system switch-generation}.
10352 Although the @command{guix system reconfigure} command will not modify
10353 previous generations, you must take care when the current generation is not
10354 the latest (e.g., after invoking @command{guix system roll-back}), since
10355 the operation might overwrite a later generation (@pxref{Invoking guix
10358 @unnumberedsubsec The Programming Interface
10360 At the Scheme level, the bulk of an @code{operating-system} declaration
10361 is instantiated with the following monadic procedure (@pxref{The Store
10364 @deffn {Monadic Procedure} operating-system-derivation os
10365 Return a derivation that builds @var{os}, an @code{operating-system}
10366 object (@pxref{Derivations}).
10368 The output of the derivation is a single directory that refers to all
10369 the packages, configuration files, and other supporting files needed to
10370 instantiate @var{os}.
10373 This procedure is provided by the @code{(gnu system)} module. Along
10374 with @code{(gnu services)} (@pxref{Services}), this module contains the
10375 guts of Guix System. Make sure to visit it!
10378 @node operating-system Reference
10379 @section @code{operating-system} Reference
10381 This section summarizes all the options available in
10382 @code{operating-system} declarations (@pxref{Using the Configuration
10385 @deftp {Data Type} operating-system
10386 This is the data type representing an operating system configuration.
10387 By that, we mean all the global system configuration, not per-user
10388 configuration (@pxref{Using the Configuration System}).
10391 @item @code{kernel} (default: @var{linux-libre})
10392 The package object of the operating system kernel to use@footnote{Currently
10393 only the Linux-libre kernel is supported. In the future, it will be
10394 possible to use the GNU@tie{}Hurd.}.
10396 @item @code{kernel-arguments} (default: @code{'()})
10397 List of strings or gexps representing additional arguments to pass on
10398 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
10400 @item @code{bootloader}
10401 The system bootloader configuration object. @xref{Bootloader Configuration}.
10403 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
10405 @cindex initial RAM disk
10406 The list of Linux kernel modules that need to be available in the
10407 initial RAM disk. @xref{Initial RAM Disk}.
10409 @item @code{initrd} (default: @code{base-initrd})
10410 A procedure that returns an initial RAM disk for the Linux
10411 kernel. This field is provided to support low-level customization and
10412 should rarely be needed for casual use. @xref{Initial RAM Disk}.
10414 @item @code{firmware} (default: @var{%base-firmware})
10416 List of firmware packages loadable by the operating system kernel.
10418 The default includes firmware needed for Atheros- and Broadcom-based
10419 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
10420 respectively). @xref{Hardware Considerations}, for more info on
10421 supported hardware.
10423 @item @code{host-name}
10426 @item @code{hosts-file}
10428 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
10429 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
10430 Reference Manual}). The default is a file with entries for
10431 @code{localhost} and @var{host-name}.
10433 @item @code{mapped-devices} (default: @code{'()})
10434 A list of mapped devices. @xref{Mapped Devices}.
10436 @item @code{file-systems}
10437 A list of file systems. @xref{File Systems}.
10439 @item @code{swap-devices} (default: @code{'()})
10440 @cindex swap devices
10441 A list of strings identifying devices or files to be used for ``swap
10442 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
10443 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
10444 It is possible to specify a swap file in a file system on a mapped
10445 device, provided that the necessary device mapping and file system are
10446 also specified. @xref{Mapped Devices} and @ref{File Systems}.
10448 @item @code{users} (default: @code{%base-user-accounts})
10449 @itemx @code{groups} (default: @var{%base-groups})
10450 List of user accounts and groups. @xref{User Accounts}.
10452 If the @code{users} list lacks a user account with UID@tie{}0, a
10453 ``root'' account with UID@tie{}0 is automatically added.
10455 @item @code{skeletons} (default: @code{(default-skeletons)})
10456 A list target file name/file-like object tuples (@pxref{G-Expressions,
10457 file-like objects}). These are the skeleton files that will be added to
10458 the home directory of newly-created user accounts.
10460 For instance, a valid value may look like this:
10463 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
10464 (".guile" ,(plain-file "guile"
10465 "(use-modules (ice-9 readline))
10466 (activate-readline)")))
10469 @item @code{issue} (default: @var{%default-issue})
10470 A string denoting the contents of the @file{/etc/issue} file, which is
10471 displayed when users log in on a text console.
10473 @item @code{packages} (default: @var{%base-packages})
10474 The set of packages installed in the global profile, which is accessible
10475 at @file{/run/current-system/profile}.
10477 The default set includes core utilities and it is good practice to
10478 install non-core utilities in user profiles (@pxref{Invoking guix
10481 @item @code{timezone}
10482 A timezone identifying string---e.g., @code{"Europe/Paris"}.
10484 You can run the @command{tzselect} command to find out which timezone
10485 string corresponds to your region. Choosing an invalid timezone name
10486 causes @command{guix system} to fail.
10488 @item @code{locale} (default: @code{"en_US.utf8"})
10489 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
10490 Library Reference Manual}). @xref{Locales}, for more information.
10492 @item @code{locale-definitions} (default: @var{%default-locale-definitions})
10493 The list of locale definitions to be compiled and that may be used at
10494 run time. @xref{Locales}.
10496 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
10497 The list of GNU@tie{}libc packages whose locale data and tools are used
10498 to build the locale definitions. @xref{Locales}, for compatibility
10499 considerations that justify this option.
10501 @item @code{name-service-switch} (default: @var{%default-nss})
10502 Configuration of the libc name service switch (NSS)---a
10503 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
10506 @item @code{services} (default: @var{%base-services})
10507 A list of service objects denoting system services. @xref{Services}.
10509 @item @code{pam-services} (default: @code{(base-pam-services)})
10511 @cindex pluggable authentication modules
10512 Linux @dfn{pluggable authentication module} (PAM) services.
10513 @c FIXME: Add xref to PAM services section.
10515 @item @code{setuid-programs} (default: @var{%setuid-programs})
10516 List of string-valued G-expressions denoting setuid programs.
10517 @xref{Setuid Programs}.
10519 @item @code{sudoers-file} (default: @var{%sudoers-specification})
10520 @cindex sudoers file
10521 The contents of the @file{/etc/sudoers} file as a file-like object
10522 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
10524 This file specifies which users can use the @command{sudo} command, what
10525 they are allowed to do, and what privileges they may gain. The default
10526 is that only @code{root} and members of the @code{wheel} group may use
10533 @section File Systems
10535 The list of file systems to be mounted is specified in the
10536 @code{file-systems} field of the operating system declaration
10537 (@pxref{Using the Configuration System}). Each file system is declared
10538 using the @code{file-system} form, like this:
10542 (mount-point "/home")
10543 (device "/dev/sda3")
10547 As usual, some of the fields are mandatory---those shown in the example
10548 above---while others can be omitted. These are described below.
10550 @deftp {Data Type} file-system
10551 Objects of this type represent file systems to be mounted. They
10552 contain the following members:
10556 This is a string specifying the type of the file system---e.g.,
10559 @item @code{mount-point}
10560 This designates the place where the file system is to be mounted.
10562 @item @code{device}
10563 This names the ``source'' of the file system. It can be one of three
10564 things: a file system label, a file system UUID, or the name of a
10565 @file{/dev} node. Labels and UUIDs offer a way to refer to file
10566 systems without having to hard-code their actual device
10567 name@footnote{Note that, while it is tempting to use
10568 @file{/dev/disk/by-uuid} and similar device names to achieve the same
10569 result, this is not recommended: These special device nodes are created
10570 by the udev daemon and may be unavailable at the time the device is
10573 @findex file-system-label
10574 File system labels are created using the @code{file-system-label}
10575 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
10576 plain strings. Here's an example of a file system referred to by its
10577 label, as shown by the @command{e2label} command:
10581 (mount-point "/home")
10583 (device (file-system-label "my-home")))
10587 UUIDs are converted from their string representation (as shown by the
10588 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
10589 @code{uuid} form expects 16-byte UUIDs as defined in
10590 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
10591 form of UUID used by the ext2 family of file systems and others, but it
10592 is different from ``UUIDs'' found in FAT file systems, for instance.},
10597 (mount-point "/home")
10599 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
10602 When the source of a file system is a mapped device (@pxref{Mapped
10603 Devices}), its @code{device} field @emph{must} refer to the mapped
10604 device name---e.g., @file{"/dev/mapper/root-partition"}.
10605 This is required so that
10606 the system knows that mounting the file system depends on having the
10607 corresponding device mapping established.
10609 @item @code{flags} (default: @code{'()})
10610 This is a list of symbols denoting mount flags. Recognized flags
10611 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
10612 access to special files), @code{no-suid} (ignore setuid and setgid
10613 bits), and @code{no-exec} (disallow program execution.)
10615 @item @code{options} (default: @code{#f})
10616 This is either @code{#f}, or a string denoting mount options.
10618 @item @code{mount?} (default: @code{#t})
10619 This value indicates whether to automatically mount the file system when
10620 the system is brought up. When set to @code{#f}, the file system gets
10621 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
10622 is not automatically mounted.
10624 @item @code{needed-for-boot?} (default: @code{#f})
10625 This Boolean value indicates whether the file system is needed when
10626 booting. If that is true, then the file system is mounted when the
10627 initial RAM disk (initrd) is loaded. This is always the case, for
10628 instance, for the root file system.
10630 @item @code{check?} (default: @code{#t})
10631 This Boolean indicates whether the file system needs to be checked for
10632 errors before being mounted.
10634 @item @code{create-mount-point?} (default: @code{#f})
10635 When true, the mount point is created if it does not exist yet.
10637 @item @code{dependencies} (default: @code{'()})
10638 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
10639 representing file systems that must be mounted or mapped devices that
10640 must be opened before (and unmounted or closed after) this one.
10642 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
10643 a dependency of @file{/sys/fs/cgroup/cpu} and
10644 @file{/sys/fs/cgroup/memory}.
10646 Another example is a file system that depends on a mapped device, for
10647 example for an encrypted partition (@pxref{Mapped Devices}).
10651 The @code{(gnu system file-systems)} exports the following useful
10654 @defvr {Scheme Variable} %base-file-systems
10655 These are essential file systems that are required on normal systems,
10656 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
10657 below.) Operating system declarations should always contain at least
10661 @defvr {Scheme Variable} %pseudo-terminal-file-system
10662 This is the file system to be mounted as @file{/dev/pts}. It supports
10663 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
10664 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
10665 Manual}). Pseudo-terminals are used by terminal emulators such as
10669 @defvr {Scheme Variable} %shared-memory-file-system
10670 This file system is mounted as @file{/dev/shm} and is used to support
10671 memory sharing across processes (@pxref{Memory-mapped I/O,
10672 @code{shm_open},, libc, The GNU C Library Reference Manual}).
10675 @defvr {Scheme Variable} %immutable-store
10676 This file system performs a read-only ``bind mount'' of
10677 @file{/gnu/store}, making it read-only for all the users including
10678 @code{root}. This prevents against accidental modification by software
10679 running as @code{root} or by system administrators.
10681 The daemon itself is still able to write to the store: it remounts it
10682 read-write in its own ``name space.''
10685 @defvr {Scheme Variable} %binary-format-file-system
10686 The @code{binfmt_misc} file system, which allows handling of arbitrary
10687 executable file types to be delegated to user space. This requires the
10688 @code{binfmt.ko} kernel module to be loaded.
10691 @defvr {Scheme Variable} %fuse-control-file-system
10692 The @code{fusectl} file system, which allows unprivileged users to mount
10693 and unmount user-space FUSE file systems. This requires the
10694 @code{fuse.ko} kernel module to be loaded.
10697 @node Mapped Devices
10698 @section Mapped Devices
10700 @cindex device mapping
10701 @cindex mapped devices
10702 The Linux kernel has a notion of @dfn{device mapping}: a block device,
10703 such as a hard disk partition, can be @dfn{mapped} into another device,
10704 usually in @code{/dev/mapper/},
10705 with additional processing over the data that flows through
10706 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
10707 concept of a ``mapped device'' and that of a file system: both boil down
10708 to @emph{translating} input/output operations made on a file to
10709 operations on its backing store. Thus, the Hurd implements mapped
10710 devices, like file systems, using the generic @dfn{translator} mechanism
10711 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
10712 typical example is encryption device mapping: all writes to the mapped
10713 device are encrypted, and all reads are deciphered, transparently.
10714 Guix extends this notion by considering any device or set of devices that
10715 are @dfn{transformed} in some way to create a new device; for instance,
10716 RAID devices are obtained by @dfn{assembling} several other devices, such
10717 as hard disks or partitions, into a new one that behaves as one partition.
10718 Other examples, not yet implemented, are LVM logical volumes.
10720 Mapped devices are declared using the @code{mapped-device} form,
10721 defined as follows; for examples, see below.
10723 @deftp {Data Type} mapped-device
10724 Objects of this type represent device mappings that will be made when
10725 the system boots up.
10729 This is either a string specifying the name of the block device to be mapped,
10730 such as @code{"/dev/sda3"}, or a list of such strings when several devices
10731 need to be assembled for creating a new one.
10734 This string specifies the name of the resulting mapped device. For
10735 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
10736 specifying @code{"my-partition"} leads to the creation of
10737 the @code{"/dev/mapper/my-partition"} device.
10738 For RAID devices of type @code{raid-device-mapping}, the full device name
10739 such as @code{"/dev/md0"} needs to be given.
10742 This must be a @code{mapped-device-kind} object, which specifies how
10743 @var{source} is mapped to @var{target}.
10747 @defvr {Scheme Variable} luks-device-mapping
10748 This defines LUKS block device encryption using the @command{cryptsetup}
10749 command from the package with the same name. It relies on the
10750 @code{dm-crypt} Linux kernel module.
10753 @defvr {Scheme Variable} raid-device-mapping
10754 This defines a RAID device, which is assembled using the @code{mdadm}
10755 command from the package with the same name. It requires a Linux kernel
10756 module for the appropriate RAID level to be loaded, such as @code{raid456}
10757 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
10760 @cindex disk encryption
10762 The following example specifies a mapping from @file{/dev/sda3} to
10763 @file{/dev/mapper/home} using LUKS---the
10764 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
10765 standard mechanism for disk encryption.
10766 The @file{/dev/mapper/home}
10767 device can then be used as the @code{device} of a @code{file-system}
10768 declaration (@pxref{File Systems}).
10772 (source "/dev/sda3")
10774 (type luks-device-mapping))
10777 Alternatively, to become independent of device numbering, one may obtain
10778 the LUKS UUID (@dfn{unique identifier}) of the source device by a
10782 cryptsetup luksUUID /dev/sda3
10785 and use it as follows:
10789 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
10791 (type luks-device-mapping))
10794 @cindex swap encryption
10795 It is also desirable to encrypt swap space, since swap space may contain
10796 sensitive data. One way to accomplish that is to use a swap file in a
10797 file system on a device mapped via LUKS encryption. In this way, the
10798 swap file is encrypted because the entire device is encrypted.
10799 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
10801 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
10802 may be declared as follows:
10806 (source (list "/dev/sda1" "/dev/sdb1"))
10807 (target "/dev/md0")
10808 (type raid-device-mapping))
10811 The @file{/dev/md0} device can then be used as the @code{device} of a
10812 @code{file-system} declaration (@pxref{File Systems}).
10813 Note that the RAID level need not be given; it is chosen during the
10814 initial creation and formatting of the RAID device and is determined
10815 automatically later.
10818 @node User Accounts
10819 @section User Accounts
10823 @cindex user accounts
10824 User accounts and groups are entirely managed through the
10825 @code{operating-system} declaration. They are specified with the
10826 @code{user-account} and @code{user-group} forms:
10832 (supplementary-groups '("wheel" ;allow use of sudo, etc.
10833 "audio" ;sound card
10834 "video" ;video devices such as webcams
10835 "cdrom")) ;the good ol' CD-ROM
10836 (comment "Bob's sister")
10837 (home-directory "/home/alice"))
10840 When booting or upon completion of @command{guix system reconfigure},
10841 the system ensures that only the user accounts and groups specified in
10842 the @code{operating-system} declaration exist, and with the specified
10843 properties. Thus, account or group creations or modifications made by
10844 directly invoking commands such as @command{useradd} are lost upon
10845 reconfiguration or reboot. This ensures that the system remains exactly
10848 @deftp {Data Type} user-account
10849 Objects of this type represent user accounts. The following members may
10854 The name of the user account.
10858 This is the name (a string) or identifier (a number) of the user group
10859 this account belongs to.
10861 @item @code{supplementary-groups} (default: @code{'()})
10862 Optionally, this can be defined as a list of group names that this
10863 account belongs to.
10865 @item @code{uid} (default: @code{#f})
10866 This is the user ID for this account (a number), or @code{#f}. In the
10867 latter case, a number is automatically chosen by the system when the
10868 account is created.
10870 @item @code{comment} (default: @code{""})
10871 A comment about the account, such as the account owner's full name.
10873 @item @code{home-directory}
10874 This is the name of the home directory for the account.
10876 @item @code{create-home-directory?} (default: @code{#t})
10877 Indicates whether the home directory of this account should be created
10878 if it does not exist yet.
10880 @item @code{shell} (default: Bash)
10881 This is a G-expression denoting the file name of a program to be used as
10882 the shell (@pxref{G-Expressions}).
10884 @item @code{system?} (default: @code{#f})
10885 This Boolean value indicates whether the account is a ``system''
10886 account. System accounts are sometimes treated specially; for instance,
10887 graphical login managers do not list them.
10889 @anchor{user-account-password}
10890 @cindex password, for user accounts
10891 @item @code{password} (default: @code{#f})
10892 You would normally leave this field to @code{#f}, initialize user
10893 passwords as @code{root} with the @command{passwd} command, and then let
10894 users change it with @command{passwd}. Passwords set with
10895 @command{passwd} are of course preserved across reboot and
10898 If you @emph{do} want to set an initial password for an account, then
10899 this field must contain the encrypted password, as a string. You can use the
10900 @code{crypt} procedure for this purpose:
10905 (home-directory "/home/charlie")
10908 ;; Specify a SHA-512-hashed initial password.
10909 (password (crypt "InitialPassword!" "$6$abc")))
10913 The hash of this initial password will be available in a file in
10914 @file{/gnu/store}, readable by all the users, so this method must be used with
10918 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
10919 more information on password encryption, and @ref{Encryption,,, guile, GNU
10920 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
10926 User group declarations are even simpler:
10929 (user-group (name "students"))
10932 @deftp {Data Type} user-group
10933 This type is for, well, user groups. There are just a few fields:
10937 The name of the group.
10939 @item @code{id} (default: @code{#f})
10940 The group identifier (a number). If @code{#f}, a new number is
10941 automatically allocated when the group is created.
10943 @item @code{system?} (default: @code{#f})
10944 This Boolean value indicates whether the group is a ``system'' group.
10945 System groups have low numerical IDs.
10947 @item @code{password} (default: @code{#f})
10948 What, user groups can have a password? Well, apparently yes. Unless
10949 @code{#f}, this field specifies the password of the group.
10954 For convenience, a variable lists all the basic user groups one may
10957 @defvr {Scheme Variable} %base-groups
10958 This is the list of basic user groups that users and/or packages expect
10959 to be present on the system. This includes groups such as ``root'',
10960 ``wheel'', and ``users'', as well as groups used to control access to
10961 specific devices such as ``audio'', ``disk'', and ``cdrom''.
10964 @defvr {Scheme Variable} %base-user-accounts
10965 This is the list of basic system accounts that programs may expect to
10966 find on a GNU/Linux system, such as the ``nobody'' account.
10968 Note that the ``root'' account is not included here. It is a
10969 special-case and is automatically added whether or not it is specified.
10976 A @dfn{locale} defines cultural conventions for a particular language
10977 and region of the world (@pxref{Locales,,, libc, The GNU C Library
10978 Reference Manual}). Each locale has a name that typically has the form
10979 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
10980 @code{fr_LU.utf8} designates the locale for the French language, with
10981 cultural conventions from Luxembourg, and using the UTF-8 encoding.
10983 @cindex locale definition
10984 Usually, you will want to specify the default locale for the machine
10985 using the @code{locale} field of the @code{operating-system} declaration
10986 (@pxref{operating-system Reference, @code{locale}}).
10988 The selected locale is automatically added to the @dfn{locale
10989 definitions} known to the system if needed, with its codeset inferred
10990 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
10991 @code{UTF-8} codeset. Additional locale definitions can be specified in
10992 the @code{locale-definitions} slot of @code{operating-system}---this is
10993 useful, for instance, if the codeset could not be inferred from the
10994 locale name. The default set of locale definitions includes some widely
10995 used locales, but not all the available locales, in order to save space.
10997 For instance, to add the North Frisian locale for Germany, the value of
11001 (cons (locale-definition
11002 (name "fy_DE.utf8") (source "fy_DE"))
11003 %default-locale-definitions)
11006 Likewise, to save space, one might want @code{locale-definitions} to
11007 list only the locales that are actually used, as in:
11010 (list (locale-definition
11011 (name "ja_JP.eucjp") (source "ja_JP")
11012 (charset "EUC-JP")))
11016 The compiled locale definitions are available at
11017 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
11018 version, which is the default location where the GNU@tie{}libc provided
11019 by Guix looks for locale data. This can be overridden using the
11020 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
11021 @code{LOCPATH} and locale packages}).
11023 The @code{locale-definition} form is provided by the @code{(gnu system
11024 locale)} module. Details are given below.
11026 @deftp {Data Type} locale-definition
11027 This is the data type of a locale definition.
11032 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
11033 Reference Manual}, for more information on locale names.
11035 @item @code{source}
11036 The name of the source for that locale. This is typically the
11037 @code{@var{language}_@var{territory}} part of the locale name.
11039 @item @code{charset} (default: @code{"UTF-8"})
11040 The ``character set'' or ``code set'' for that locale,
11041 @uref{http://www.iana.org/assignments/character-sets, as defined by
11047 @defvr {Scheme Variable} %default-locale-definitions
11048 A list of commonly used UTF-8 locales, used as the default
11049 value of the @code{locale-definitions} field of @code{operating-system}
11052 @cindex locale name
11053 @cindex normalized codeset in locale names
11054 These locale definitions use the @dfn{normalized codeset} for the part
11055 that follows the dot in the name (@pxref{Using gettextized software,
11056 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
11057 instance it has @code{uk_UA.utf8} but @emph{not}, say,
11058 @code{uk_UA.UTF-8}.
11061 @subsection Locale Data Compatibility Considerations
11063 @cindex incompatibility, of locale data
11064 @code{operating-system} declarations provide a @code{locale-libcs} field
11065 to specify the GNU@tie{}libc packages that are used to compile locale
11066 declarations (@pxref{operating-system Reference}). ``Why would I
11067 care?'', you may ask. Well, it turns out that the binary format of
11068 locale data is occasionally incompatible from one libc version to
11071 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
11072 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
11073 For instance, a program linked against libc version 2.21 is unable to
11074 read locale data produced with libc 2.22; worse, that program
11075 @emph{aborts} instead of simply ignoring the incompatible locale
11076 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
11077 the incompatible locale data, which is already an improvement.}.
11078 Similarly, a program linked against libc 2.22 can read most, but not
11079 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
11080 data is incompatible); thus calls to @code{setlocale} may fail, but
11081 programs will not abort.
11083 The ``problem'' with Guix is that users have a lot of freedom: They can
11084 choose whether and when to upgrade software in their profiles, and might
11085 be using a libc version different from the one the system administrator
11086 used to build the system-wide locale data.
11088 Fortunately, unprivileged users can also install their own locale data
11089 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
11090 @code{GUIX_LOCPATH} and locale packages}).
11092 Still, it is best if the system-wide locale data at
11093 @file{/run/current-system/locale} is built for all the libc versions
11094 actually in use on the system, so that all the programs can access
11095 it---this is especially crucial on a multi-user system. To do that, the
11096 administrator can specify several libc packages in the
11097 @code{locale-libcs} field of @code{operating-system}:
11100 (use-package-modules base)
11104 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
11107 This example would lead to a system containing locale definitions for
11108 both libc 2.21 and the current version of libc in
11109 @file{/run/current-system/locale}.
11115 @cindex system services
11116 An important part of preparing an @code{operating-system} declaration is
11117 listing @dfn{system services} and their configuration (@pxref{Using the
11118 Configuration System}). System services are typically daemons launched
11119 when the system boots, or other actions needed at that time---e.g.,
11120 configuring network access.
11122 Guix has a broad definition of ``service'' (@pxref{Service
11123 Composition}), but many services are managed by the GNU@tie{}Shepherd
11124 (@pxref{Shepherd Services}). On a running system, the @command{herd}
11125 command allows you to list the available services, show their status,
11126 start and stop them, or do other specific operations (@pxref{Jump
11127 Start,,, shepherd, The GNU Shepherd Manual}). For example:
11133 The above command, run as @code{root}, lists the currently defined
11134 services. The @command{herd doc} command shows a synopsis of the given
11135 service and its associated actions:
11139 Run libc's name service cache daemon (nscd).
11141 # herd doc nscd action invalidate
11142 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
11145 The @command{start}, @command{stop}, and @command{restart} sub-commands
11146 have the effect you would expect. For instance, the commands below stop
11147 the nscd service and restart the Xorg display server:
11151 Service nscd has been stopped.
11152 # herd restart xorg-server
11153 Service xorg-server has been stopped.
11154 Service xorg-server has been started.
11157 The following sections document the available services, starting with
11158 the core services, that may be used in an @code{operating-system}
11162 * Base Services:: Essential system services.
11163 * Scheduled Job Execution:: The mcron service.
11164 * Log Rotation:: The rottlog service.
11165 * Networking Services:: Network setup, SSH daemon, etc.
11166 * X Window:: Graphical display.
11167 * Printing Services:: Local and remote printer support.
11168 * Desktop Services:: D-Bus and desktop services.
11169 * Sound Services:: ALSA and Pulseaudio services.
11170 * Database Services:: SQL databases, key-value stores, etc.
11171 * Mail Services:: IMAP, POP3, SMTP, and all that.
11172 * Messaging Services:: Messaging services.
11173 * Telephony Services:: Telephony services.
11174 * Monitoring Services:: Monitoring services.
11175 * Kerberos Services:: Kerberos services.
11176 * LDAP Services:: LDAP services.
11177 * Web Services:: Web servers.
11178 * Certificate Services:: TLS certificates via Let's Encrypt.
11179 * DNS Services:: DNS daemons.
11180 * VPN Services:: VPN daemons.
11181 * Network File System:: NFS related services.
11182 * Continuous Integration:: The Cuirass service.
11183 * Power Management Services:: Extending battery life.
11184 * Audio Services:: The MPD.
11185 * Virtualization Services:: Virtualization services.
11186 * Version Control Services:: Providing remote access to Git repositories.
11187 * Game Services:: Game servers.
11188 * Miscellaneous Services:: Other services.
11191 @node Base Services
11192 @subsection Base Services
11194 The @code{(gnu services base)} module provides definitions for the basic
11195 services that one expects from the system. The services exported by
11196 this module are listed below.
11198 @defvr {Scheme Variable} %base-services
11199 This variable contains a list of basic services (@pxref{Service Types
11200 and Services}, for more information on service objects) one would
11201 expect from the system: a login service (mingetty) on each tty, syslogd,
11202 the libc name service cache daemon (nscd), the udev device manager, and
11205 This is the default value of the @code{services} field of
11206 @code{operating-system} declarations. Usually, when customizing a
11207 system, you will want to append services to @var{%base-services}, like
11211 (append (list (service avahi-service-type)
11212 (service openssh-service-type))
11217 @defvr {Scheme Variable} special-files-service-type
11218 This is the service that sets up ``special files'' such as
11219 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
11221 The value associated with @code{special-files-service-type} services
11222 must be a list of tuples where the first element is the ``special file''
11223 and the second element is its target. By default it is:
11225 @cindex @file{/bin/sh}
11226 @cindex @file{sh}, in @file{/bin}
11228 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
11231 @cindex @file{/usr/bin/env}
11232 @cindex @file{env}, in @file{/usr/bin}
11233 If you want to add, say, @code{/usr/bin/env} to your system, you can
11237 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
11238 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
11241 Since this is part of @code{%base-services}, you can use
11242 @code{modify-services} to customize the set of special files
11243 (@pxref{Service Reference, @code{modify-services}}). But the simple way
11244 to add a special file is @i{via} the @code{extra-special-file} procedure
11248 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
11249 Use @var{target} as the ``special file'' @var{file}.
11251 For example, adding the following lines to the @code{services} field of
11252 your operating system declaration leads to a @file{/usr/bin/env}
11256 (extra-special-file "/usr/bin/env"
11257 (file-append coreutils "/bin/env"))
11261 @deffn {Scheme Procedure} host-name-service @var{name}
11262 Return a service that sets the host name to @var{name}.
11265 @deffn {Scheme Procedure} login-service @var{config}
11266 Return a service to run login according to @var{config}, a
11267 @code{<login-configuration>} object, which specifies the message of the day,
11268 among other things.
11271 @deftp {Data Type} login-configuration
11272 This is the data type representing the configuration of login.
11277 @cindex message of the day
11278 A file-like object containing the ``message of the day''.
11280 @item @code{allow-empty-passwords?} (default: @code{#t})
11281 Allow empty passwords by default so that first-time users can log in when
11282 the 'root' account has just been created.
11287 @deffn {Scheme Procedure} mingetty-service @var{config}
11288 Return a service to run mingetty according to @var{config}, a
11289 @code{<mingetty-configuration>} object, which specifies the tty to run, among
11293 @deftp {Data Type} mingetty-configuration
11294 This is the data type representing the configuration of Mingetty, which
11295 provides the default implementation of virtual console log-in.
11300 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
11302 @item @code{auto-login} (default: @code{#f})
11303 When true, this field must be a string denoting the user name under
11304 which the system automatically logs in. When it is @code{#f}, a
11305 user name and password must be entered to log in.
11307 @item @code{login-program} (default: @code{#f})
11308 This must be either @code{#f}, in which case the default log-in program
11309 is used (@command{login} from the Shadow tool suite), or a gexp denoting
11310 the name of the log-in program.
11312 @item @code{login-pause?} (default: @code{#f})
11313 When set to @code{#t} in conjunction with @var{auto-login}, the user
11314 will have to press a key before the log-in shell is launched.
11316 @item @code{mingetty} (default: @var{mingetty})
11317 The Mingetty package to use.
11322 @deffn {Scheme Procedure} agetty-service @var{config}
11323 Return a service to run agetty according to @var{config}, an
11324 @code{<agetty-configuration>} object, which specifies the tty to run,
11325 among other things.
11328 @deftp {Data Type} agetty-configuration
11329 This is the data type representing the configuration of agetty, which
11330 implements virtual and serial console log-in. See the @code{agetty(8)}
11331 man page for more information.
11336 The name of the console this agetty runs on, as a string---e.g.,
11337 @code{"ttyS0"}. This argument is optional, it will default to
11338 a reasonable default serial port used by the kernel Linux.
11340 For this, if there is a value for an option @code{agetty.tty} in the kernel
11341 command line, agetty will extract the device name of the serial port
11342 from it and use that.
11344 If not and if there is a value for an option @code{console} with a tty in
11345 the Linux command line, agetty will extract the device name of the
11346 serial port from it and use that.
11348 In both cases, agetty will leave the other serial device settings
11349 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
11352 @item @code{baud-rate} (default: @code{#f})
11353 A string containing a comma-separated list of one or more baud rates, in
11356 @item @code{term} (default: @code{#f})
11357 A string containing the value used for the @code{TERM} environment
11360 @item @code{eight-bits?} (default: @code{#f})
11361 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
11364 @item @code{auto-login} (default: @code{#f})
11365 When passed a login name, as a string, the specified user will be logged
11366 in automatically without prompting for their login name or password.
11368 @item @code{no-reset?} (default: @code{#f})
11369 When @code{#t}, don't reset terminal cflags (control modes).
11371 @item @code{host} (default: @code{#f})
11372 This accepts a string containing the "login_host", which will be written
11373 into the @file{/var/run/utmpx} file.
11375 @item @code{remote?} (default: @code{#f})
11376 When set to @code{#t} in conjunction with @var{host}, this will add an
11377 @code{-r} fakehost option to the command line of the login program
11378 specified in @var{login-program}.
11380 @item @code{flow-control?} (default: @code{#f})
11381 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
11383 @item @code{no-issue?} (default: @code{#f})
11384 When set to @code{#t}, the contents of the @file{/etc/issue} file will
11385 not be displayed before presenting the login prompt.
11387 @item @code{init-string} (default: @code{#f})
11388 This accepts a string that will be sent to the tty or modem before
11389 sending anything else. It can be used to initialize a modem.
11391 @item @code{no-clear?} (default: @code{#f})
11392 When set to @code{#t}, agetty will not clear the screen before showing
11395 @item @code{login-program} (default: (file-append shadow "/bin/login"))
11396 This must be either a gexp denoting the name of a log-in program, or
11397 unset, in which case the default value is the @command{login} from the
11400 @item @code{local-line} (default: @code{#f})
11401 Control the CLOCAL line flag. This accepts one of three symbols as
11402 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
11403 the default value chosen by agetty is @code{'auto}.
11405 @item @code{extract-baud?} (default: @code{#f})
11406 When set to @code{#t}, instruct agetty to try to extract the baud rate
11407 from the status messages produced by certain types of modems.
11409 @item @code{skip-login?} (default: @code{#f})
11410 When set to @code{#t}, do not prompt the user for a login name. This
11411 can be used with @var{login-program} field to use non-standard login
11414 @item @code{no-newline?} (default: @code{#f})
11415 When set to @code{#t}, do not print a newline before printing the
11416 @file{/etc/issue} file.
11418 @c Is this dangerous only when used with login-program, or always?
11419 @item @code{login-options} (default: @code{#f})
11420 This option accepts a string containing options that are passed to the
11421 login program. When used with the @var{login-program}, be aware that a
11422 malicious user could try to enter a login name containing embedded
11423 options that could be parsed by the login program.
11425 @item @code{login-pause} (default: @code{#f})
11426 When set to @code{#t}, wait for any key before showing the login prompt.
11427 This can be used in conjunction with @var{auto-login} to save memory by
11428 lazily spawning shells.
11430 @item @code{chroot} (default: @code{#f})
11431 Change root to the specified directory. This option accepts a directory
11434 @item @code{hangup?} (default: @code{#f})
11435 Use the Linux system call @code{vhangup} to do a virtual hangup of the
11436 specified terminal.
11438 @item @code{keep-baud?} (default: @code{#f})
11439 When set to @code{#t}, try to keep the existing baud rate. The baud
11440 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
11443 @item @code{timeout} (default: @code{#f})
11444 When set to an integer value, terminate if no user name could be read
11445 within @var{timeout} seconds.
11447 @item @code{detect-case?} (default: @code{#f})
11448 When set to @code{#t}, turn on support for detecting an uppercase-only
11449 terminal. This setting will detect a login name containing only
11450 uppercase letters as indicating an uppercase-only terminal and turn on
11451 some upper-to-lower case conversions. Note that this will not support
11452 Unicode characters.
11454 @item @code{wait-cr?} (default: @code{#f})
11455 When set to @code{#t}, wait for the user or modem to send a
11456 carriage-return or linefeed character before displaying
11457 @file{/etc/issue} or login prompt. This is typically used with the
11458 @var{init-string} option.
11460 @item @code{no-hints?} (default: @code{#f})
11461 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
11464 @item @code{no-hostname?} (default: @code{#f})
11465 By default, the hostname is printed. When this option is set to
11466 @code{#t}, no hostname will be shown at all.
11468 @item @code{long-hostname?} (default: @code{#f})
11469 By default, the hostname is only printed until the first dot. When this
11470 option is set to @code{#t}, the fully qualified hostname by
11471 @code{gethostname} or @code{getaddrinfo} is shown.
11473 @item @code{erase-characters} (default: @code{#f})
11474 This option accepts a string of additional characters that should be
11475 interpreted as backspace when the user types their login name.
11477 @item @code{kill-characters} (default: @code{#f})
11478 This option accepts a string that should be interpreted to mean "ignore
11479 all previous characters" (also called a "kill" character) when the types
11482 @item @code{chdir} (default: @code{#f})
11483 This option accepts, as a string, a directory path that will be changed
11486 @item @code{delay} (default: @code{#f})
11487 This options accepts, as an integer, the number of seconds to sleep
11488 before opening the tty and displaying the login prompt.
11490 @item @code{nice} (default: @code{#f})
11491 This option accepts, as an integer, the nice value with which to run the
11492 @command{login} program.
11494 @item @code{extra-options} (default: @code{'()})
11495 This option provides an "escape hatch" for the user to provide arbitrary
11496 command-line arguments to @command{agetty} as a list of strings.
11501 @deffn {Scheme Procedure} kmscon-service-type @var{config}
11502 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
11503 according to @var{config}, a @code{<kmscon-configuration>} object, which
11504 specifies the tty to run, among other things.
11507 @deftp {Data Type} kmscon-configuration
11508 This is the data type representing the configuration of Kmscon, which
11509 implements virtual console log-in.
11513 @item @code{virtual-terminal}
11514 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
11516 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
11517 A gexp denoting the name of the log-in program. The default log-in program is
11518 @command{login} from the Shadow tool suite.
11520 @item @code{login-arguments} (default: @code{'("-p")})
11521 A list of arguments to pass to @command{login}.
11523 @item @code{auto-login} (default: @code{#f})
11524 When passed a login name, as a string, the specified user will be logged
11525 in automatically without prompting for their login name or password.
11527 @item @code{hardware-acceleration?} (default: #f)
11528 Whether to use hardware acceleration.
11530 @item @code{kmscon} (default: @var{kmscon})
11531 The Kmscon package to use.
11536 @cindex name service cache daemon
11538 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
11539 [#:name-services '()]
11540 Return a service that runs the libc name service cache daemon (nscd) with the
11541 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
11542 Service Switch}, for an example.
11544 For convenience, the Shepherd service for nscd provides the following actions:
11548 @cindex cache invalidation, nscd
11549 @cindex nscd, cache invalidation
11550 This invalidate the given cache. For instance, running:
11553 herd invalidate nscd hosts
11557 invalidates the host name lookup cache of nscd.
11560 Running @command{herd statistics nscd} displays information about nscd usage
11566 @defvr {Scheme Variable} %nscd-default-configuration
11567 This is the default @code{<nscd-configuration>} value (see below) used
11568 by @code{nscd-service}. It uses the caches defined by
11569 @var{%nscd-default-caches}; see below.
11572 @deftp {Data Type} nscd-configuration
11573 This is the data type representing the name service cache daemon (nscd)
11578 @item @code{name-services} (default: @code{'()})
11579 List of packages denoting @dfn{name services} that must be visible to
11580 the nscd---e.g., @code{(list @var{nss-mdns})}.
11582 @item @code{glibc} (default: @var{glibc})
11583 Package object denoting the GNU C Library providing the @command{nscd}
11586 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
11587 Name of the nscd log file. This is where debugging output goes when
11588 @code{debug-level} is strictly positive.
11590 @item @code{debug-level} (default: @code{0})
11591 Integer denoting the debugging levels. Higher numbers mean that more
11592 debugging output is logged.
11594 @item @code{caches} (default: @var{%nscd-default-caches})
11595 List of @code{<nscd-cache>} objects denoting things to be cached; see
11601 @deftp {Data Type} nscd-cache
11602 Data type representing a cache database of nscd and its parameters.
11606 @item @code{database}
11607 This is a symbol representing the name of the database to be cached.
11608 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
11609 @code{services}, which designate the corresponding NSS database
11610 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
11612 @item @code{positive-time-to-live}
11613 @itemx @code{negative-time-to-live} (default: @code{20})
11614 A number representing the number of seconds during which a positive or
11615 negative lookup result remains in cache.
11617 @item @code{check-files?} (default: @code{#t})
11618 Whether to check for updates of the files corresponding to
11621 For instance, when @var{database} is @code{hosts}, setting this flag
11622 instructs nscd to check for updates in @file{/etc/hosts} and to take
11625 @item @code{persistent?} (default: @code{#t})
11626 Whether the cache should be stored persistently on disk.
11628 @item @code{shared?} (default: @code{#t})
11629 Whether the cache should be shared among users.
11631 @item @code{max-database-size} (default: 32@tie{}MiB)
11632 Maximum size in bytes of the database cache.
11634 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
11635 @c settings, so leave them out.
11640 @defvr {Scheme Variable} %nscd-default-caches
11641 List of @code{<nscd-cache>} objects used by default by
11642 @code{nscd-configuration} (see above).
11644 It enables persistent and aggressive caching of service and host name
11645 lookups. The latter provides better host name lookup performance,
11646 resilience in the face of unreliable name servers, and also better
11647 privacy---often the result of host name lookups is in local cache, so
11648 external name servers do not even need to be queried.
11651 @anchor{syslog-configuration-type}
11654 @deftp {Data Type} syslog-configuration
11655 This data type represents the configuration of the syslog daemon.
11658 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
11659 The syslog daemon to use.
11661 @item @code{config-file} (default: @code{%default-syslog.conf})
11662 The syslog configuration file to use.
11667 @anchor{syslog-service}
11669 @deffn {Scheme Procedure} syslog-service @var{config}
11670 Return a service that runs a syslog daemon according to @var{config}.
11672 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
11673 information on the configuration file syntax.
11676 @defvr {Scheme Variable} guix-service-type
11677 This is the type of the service that runs the build daemon,
11678 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
11679 @code{guix-configuration} record as described below.
11682 @anchor{guix-configuration-type}
11683 @deftp {Data Type} guix-configuration
11684 This data type represents the configuration of the Guix build daemon.
11685 @xref{Invoking guix-daemon}, for more information.
11688 @item @code{guix} (default: @var{guix})
11689 The Guix package to use.
11691 @item @code{build-group} (default: @code{"guixbuild"})
11692 Name of the group for build user accounts.
11694 @item @code{build-accounts} (default: @code{10})
11695 Number of build user accounts to create.
11697 @item @code{authorize-key?} (default: @code{#t})
11698 @cindex substitutes, authorization thereof
11699 Whether to authorize the substitute keys listed in
11700 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
11701 (@pxref{Substitutes}).
11703 @vindex %default-authorized-guix-keys
11704 @item @code{authorized-keys} (default: @var{%default-authorized-guix-keys})
11705 The list of authorized key files for archive imports, as a list of
11706 string-valued gexps (@pxref{Invoking guix archive}). By default, it
11707 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
11709 @item @code{use-substitutes?} (default: @code{#t})
11710 Whether to use substitutes.
11712 @item @code{substitute-urls} (default: @var{%default-substitute-urls})
11713 The list of URLs where to look for substitutes by default.
11715 @item @code{max-silent-time} (default: @code{0})
11716 @itemx @code{timeout} (default: @code{0})
11717 The number of seconds of silence and the number of seconds of activity,
11718 respectively, after which a build process times out. A value of zero
11719 disables the timeout.
11721 @item @code{log-compression} (default: @code{'bzip2})
11722 The type of compression used for build logs---one of @code{gzip},
11723 @code{bzip2}, or @code{none}.
11725 @item @code{extra-options} (default: @code{'()})
11726 List of extra command-line options for @command{guix-daemon}.
11728 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
11729 File where @command{guix-daemon}'s standard output and standard error
11732 @item @code{http-proxy} (default: @code{#f})
11733 The HTTP proxy used for downloading fixed-output derivations and
11736 @item @code{tmpdir} (default: @code{#f})
11737 A directory path where the @command{guix-daemon} will perform builds.
11742 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
11743 Run @var{udev}, which populates the @file{/dev} directory dynamically.
11744 udev rules can be provided as a list of files through the @var{rules}
11745 variable. The procedures @var{udev-rule} and @var{file->udev-rule} from
11746 @code{(gnu services base)} simplify the creation of such rule files.
11749 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
11750 Return a udev-rule file named @var{file-name} containing the rules
11751 defined by the @var{contents} literal.
11753 In the following example, a rule for a USB device is defined to be
11754 stored in the file @file{90-usb-thing.rules}. The rule runs a script
11755 upon detecting a USB device with a given product identifier.
11758 (define %example-udev-rule
11760 "90-usb-thing.rules"
11761 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
11762 "ATTR@{product@}==\"Example\", "
11763 "RUN+=\"/path/to/script\"")))
11766 The @command{herd rules udev} command, as root, returns the name of the
11767 directory containing all the active udev rules.
11770 Here we show how the default @var{udev-service} can be extended with it.
11776 (modify-services %desktop-services
11777 (udev-service-type config =>
11778 (udev-configuration (inherit config)
11779 (rules (append (udev-configuration-rules config)
11780 (list %example-udev-rule))))))))
11783 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
11784 Return a udev file named @var{file-name} containing the rules defined
11785 within @var{file}, a file-like object.
11787 The following example showcases how we can use an existing rule file.
11790 (use-modules (guix download) ;for url-fetch
11791 (guix packages) ;for origin
11794 (define %android-udev-rules
11796 "51-android-udev.rules"
11797 (let ((version "20170910"))
11800 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
11801 "android-udev-rules/" version "/51-android.rules"))
11803 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
11807 Additionally, Guix package definitions can be included in @var{rules} in
11808 order to extend the udev rules with the definitions found under their
11809 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
11810 @var{file->udev-rule} example, we could have used the
11811 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
11812 packages android)} module.
11814 The following example shows how to use the @var{android-udev-rules}
11815 package so that the Android tool @command{adb} can detect devices
11816 without root privileges. It also details how to create the
11817 @code{adbusers} group, which is required for the proper functioning of
11818 the rules defined within the @var{android-udev-rules} package. To
11819 create such a group, we must define it both as part of the
11820 @var{supplementary-groups} of our @var{user-account} declaration, as
11821 well as in the @var{groups} field of the @var{operating-system} record.
11824 (use-modules (gnu packages android) ;for android-udev-rules
11825 (gnu system shadow) ;for user-group
11830 (users (cons (user-acount
11832 (supplementary-groups
11833 '("adbusers" ;for adb
11834 "wheel" "netdev" "audio" "video"))
11837 (groups (cons (user-group (system? #t) (name "adbusers"))
11843 (modify-services %desktop-services
11846 (udev-configuration (inherit config)
11847 (rules (cons android-udev-rules
11848 (udev-configuration-rules config))))))))
11851 @defvr {Scheme Variable} urandom-seed-service-type
11852 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
11853 when rebooting. It also tries to seed @file{/dev/urandom} from
11854 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
11858 @defvr {Scheme Variable} %random-seed-file
11859 This is the name of the file where some random bytes are saved by
11860 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
11861 It defaults to @file{/var/lib/random-seed}.
11866 @deffn {Scheme Procedure} console-keymap-service @var{files} ...
11867 @cindex keyboard layout
11868 Return a service to load console keymaps from @var{files} using
11869 @command{loadkeys} command. Most likely, you want to load some default
11870 keymap, which can be done like this:
11873 (console-keymap-service "dvorak")
11876 Or, for example, for a Swedish keyboard, you may need to combine
11877 the following keymaps:
11879 (console-keymap-service "se-lat6" "se-fi-lat6")
11882 Also you can specify a full file name (or file names) of your keymap(s).
11883 See @code{man loadkeys} for details.
11889 @defvr {Scheme Variable} gpm-service-type
11890 This is the type of the service that runs GPM, the @dfn{general-purpose
11891 mouse daemon}, which provides mouse support to the Linux console. GPM
11892 allows users to use the mouse in the console, notably to select, copy,
11895 The value for services of this type must be a @code{gpm-configuration}
11896 (see below). This service is not part of @var{%base-services}.
11899 @deftp {Data Type} gpm-configuration
11900 Data type representing the configuration of GPM.
11903 @item @code{options} (default: @code{%default-gpm-options})
11904 Command-line options passed to @command{gpm}. The default set of
11905 options instruct @command{gpm} to listen to mouse events on
11906 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
11909 @item @code{gpm} (default: @code{gpm})
11910 The GPM package to use.
11915 @anchor{guix-publish-service-type}
11916 @deffn {Scheme Variable} guix-publish-service-type
11917 This is the service type for @command{guix publish} (@pxref{Invoking
11918 guix publish}). Its value must be a @code{guix-configuration}
11919 object, as described below.
11921 This assumes that @file{/etc/guix} already contains a signing key pair as
11922 created by @command{guix archive --generate-key} (@pxref{Invoking guix
11923 archive}). If that is not the case, the service will fail to start.
11926 @deftp {Data Type} guix-publish-configuration
11927 Data type representing the configuration of the @code{guix publish}
11931 @item @code{guix} (default: @code{guix})
11932 The Guix package to use.
11934 @item @code{port} (default: @code{80})
11935 The TCP port to listen for connections.
11937 @item @code{host} (default: @code{"localhost"})
11938 The host (and thus, network interface) to listen to. Use
11939 @code{"0.0.0.0"} to listen on all the network interfaces.
11941 @item @code{compression-level} (default: @code{3})
11942 The gzip compression level at which substitutes are compressed. Use
11943 @code{0} to disable compression altogether, and @code{9} to get the best
11944 compression ratio at the expense of increased CPU usage.
11946 @item @code{nar-path} (default: @code{"nar"})
11947 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
11948 publish, @code{--nar-path}}, for details.
11950 @item @code{cache} (default: @code{#f})
11951 When it is @code{#f}, disable caching and instead generate archives on
11952 demand. Otherwise, this should be the name of a directory---e.g.,
11953 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
11954 archives and meta-data ready to be sent. @xref{Invoking guix publish,
11955 @option{--cache}}, for more information on the tradeoffs involved.
11957 @item @code{workers} (default: @code{#f})
11958 When it is an integer, this is the number of worker threads used for
11959 caching; when @code{#f}, the number of processors is used.
11960 @xref{Invoking guix publish, @option{--workers}}, for more information.
11962 @item @code{ttl} (default: @code{#f})
11963 When it is an integer, this denotes the @dfn{time-to-live} in seconds
11964 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
11965 for more information.
11969 @anchor{rngd-service}
11970 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
11971 [#:device "/dev/hwrng"]
11972 Return a service that runs the @command{rngd} program from @var{rng-tools}
11973 to add @var{device} to the kernel's entropy pool. The service will fail if
11974 @var{device} does not exist.
11977 @anchor{pam-limits-service}
11978 @cindex session limits
11983 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
11985 Return a service that installs a configuration file for the
11986 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
11987 @code{pam_limits} module}. The procedure optionally takes a list of
11988 @code{pam-limits-entry} values, which can be used to specify
11989 @code{ulimit} limits and nice priority limits to user sessions.
11991 The following limits definition sets two hard and soft limits for all
11992 login sessions of users in the @code{realtime} group:
11995 (pam-limits-service
11997 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
11998 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
12001 The first entry increases the maximum realtime priority for
12002 non-privileged processes; the second entry lifts any restriction of the
12003 maximum address space that can be locked in memory. These settings are
12004 commonly used for real-time audio systems.
12007 @node Scheduled Job Execution
12008 @subsection Scheduled Job Execution
12012 @cindex scheduling jobs
12013 The @code{(gnu services mcron)} module provides an interface to
12014 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
12015 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
12016 Unix @command{cron} daemon; the main difference is that it is
12017 implemented in Guile Scheme, which provides a lot of flexibility when
12018 specifying the scheduling of jobs and their actions.
12020 The example below defines an operating system that runs the
12021 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
12022 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
12023 well as the @command{mkid} command on behalf of an unprivileged user
12024 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
12025 gexps to introduce job definitions that are passed to mcron
12026 (@pxref{G-Expressions}).
12029 (use-modules (guix) (gnu) (gnu services mcron))
12030 (use-package-modules base idutils)
12032 (define updatedb-job
12033 ;; Run 'updatedb' at 3AM every day. Here we write the
12034 ;; job's action as a Scheme procedure.
12035 #~(job '(next-hour '(3))
12037 (execl (string-append #$findutils "/bin/updatedb")
12039 "--prunepaths=/tmp /var/tmp /gnu/store"))))
12041 (define garbage-collector-job
12042 ;; Collect garbage 5 minutes after midnight every day.
12043 ;; The job's action is a shell command.
12044 #~(job "5 0 * * *" ;Vixie cron syntax
12047 (define idutils-job
12048 ;; Update the index database as user "charlie" at 12:15PM
12049 ;; and 19:15PM. This runs from the user's home directory.
12050 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
12051 (string-append #$idutils "/bin/mkid src")
12056 (services (cons (service mcron-service-type
12057 (mcron-configuration
12058 (jobs (list garbage-collector-job
12064 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
12065 for more information on mcron job specifications. Below is the
12066 reference of the mcron service.
12068 On a running system, you can use the @code{schedule} action of the service to
12069 visualize the mcron jobs that will be executed next:
12072 # herd schedule mcron
12076 The example above lists the next five tasks that will be executed, but you can
12077 also specify the number of tasks to display:
12080 # herd schedule mcron 10
12083 @defvr {Scheme Variable} mcron-service-type
12084 This is the type of the @code{mcron} service, whose value is an
12085 @code{mcron-configuration} object.
12087 This service type can be the target of a service extension that provides
12088 it additional job specifications (@pxref{Service Composition}). In
12089 other words, it is possible to define services that provide additional
12093 @deftp {Data Type} mcron-configuration
12094 Data type representing the configuration of mcron.
12097 @item @code{mcron} (default: @var{mcron})
12098 The mcron package to use.
12101 This is a list of gexps (@pxref{G-Expressions}), where each gexp
12102 corresponds to an mcron job specification (@pxref{Syntax, mcron job
12103 specifications,, mcron, GNU@tie{}mcron}).
12109 @subsection Log Rotation
12112 @cindex log rotation
12114 Log files such as those found in @file{/var/log} tend to grow endlessly,
12115 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
12116 their contents in separate files, possibly compressed. The @code{(gnu
12117 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
12118 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
12120 The example below defines an operating system that provides log rotation
12121 with the default settings, for commonly encountered log files.
12124 (use-modules (guix) (gnu))
12125 (use-service-modules admin mcron)
12126 (use-package-modules base idutils)
12130 (services (cons (service rottlog-service-type)
12134 @defvr {Scheme Variable} rottlog-service-type
12135 This is the type of the Rottlog service, whose value is a
12136 @code{rottlog-configuration} object.
12138 Other services can extend this one with new @code{log-rotation} objects
12139 (see below), thereby augmenting the set of files to be rotated.
12141 This service type can define mcron jobs (@pxref{Scheduled Job
12142 Execution}) to run the rottlog service.
12145 @deftp {Data Type} rottlog-configuration
12146 Data type representing the configuration of rottlog.
12149 @item @code{rottlog} (default: @code{rottlog})
12150 The Rottlog package to use.
12152 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
12153 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
12154 rottlog, GNU Rot[t]log Manual}).
12156 @item @code{rotations} (default: @code{%default-rotations})
12157 A list of @code{log-rotation} objects as defined below.
12160 This is a list of gexps where each gexp corresponds to an mcron job
12161 specification (@pxref{Scheduled Job Execution}).
12165 @deftp {Data Type} log-rotation
12166 Data type representing the rotation of a group of log files.
12168 Taking an example from the Rottlog manual (@pxref{Period Related File
12169 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
12175 (files '("/var/log/apache/*"))
12176 (options '("storedir apache-archives"
12182 The list of fields is as follows:
12185 @item @code{frequency} (default: @code{'weekly})
12186 The log rotation frequency, a symbol.
12189 The list of files or file glob patterns to rotate.
12191 @item @code{options} (default: @code{'()})
12192 The list of rottlog options for this rotation (@pxref{Configuration
12193 parameters,,, rottlog, GNU Rot[t]lg Manual}).
12195 @item @code{post-rotate} (default: @code{#f})
12196 Either @code{#f} or a gexp to execute once the rotation has completed.
12200 @defvr {Scheme Variable} %default-rotations
12201 Specifies weekly rotation of @var{%rotated-files} and
12202 a couple of other files.
12205 @defvr {Scheme Variable} %rotated-files
12206 The list of syslog-controlled files to be rotated. By default it is:
12207 @code{'("/var/log/messages" "/var/log/secure")}.
12210 @node Networking Services
12211 @subsection Networking Services
12213 The @code{(gnu services networking)} module provides services to configure
12214 the network interface.
12216 @cindex DHCP, networking service
12217 @defvr {Scheme Variable} dhcp-client-service-type
12218 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
12219 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
12220 is the DHCP client package to use, @code{isc-dhcp} by default.
12223 @deffn {Scheme Procedure} dhcpd-service-type
12224 This type defines a service that runs a DHCP daemon. To create a
12225 service of this type, you must supply a @code{<dhcpd-configuration>}.
12229 (service dhcpd-service-type
12230 (dhcpd-configuration
12231 (config-file (local-file "my-dhcpd.conf"))
12232 (interfaces '("enp0s25"))))
12236 @deftp {Data Type} dhcpd-configuration
12238 @item @code{package} (default: @code{isc-dhcp})
12239 The package that provides the DHCP daemon. This package is expected to
12240 provide the daemon at @file{sbin/dhcpd} relative to its output
12241 directory. The default package is the
12242 @uref{http://www.isc.org/products/DHCP, ISC's DHCP server}.
12243 @item @code{config-file} (default: @code{#f})
12244 The configuration file to use. This is required. It will be passed to
12245 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
12246 object (@pxref{G-Expressions, file-like objects}). See @code{man
12247 dhcpd.conf} for details on the configuration file syntax.
12248 @item @code{version} (default: @code{"4"})
12249 The DHCP version to use. The ISC DHCP server supports the values ``4'',
12250 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
12251 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
12253 @item @code{run-directory} (default: @code{"/run/dhcpd"})
12254 The run directory to use. At service activation time, this directory
12255 will be created if it does not exist.
12256 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
12257 The PID file to use. This corresponds to the @code{-pf} option of
12258 @code{dhcpd}. See @code{man dhcpd} for details.
12259 @item @code{interfaces} (default: @code{'()})
12260 The names of the network interfaces on which dhcpd should listen for
12261 broadcasts. If this list is not empty, then its elements (which must be
12262 strings) will be appended to the @code{dhcpd} invocation when starting
12263 the daemon. It may not be necessary to explicitly specify any
12264 interfaces here; see @code{man dhcpd} for details.
12268 @defvr {Scheme Variable} static-networking-service-type
12269 This is the type for statically-configured network interfaces.
12270 @c TODO Document <static-networking> data structures.
12273 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
12274 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
12275 [#:requirement @code{'(udev)}]
12276 Return a service that starts @var{interface} with address @var{ip}. If
12277 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
12278 it must be a string specifying the default network gateway. @var{requirement}
12279 can be used to declare a dependency on another service before configuring the
12282 This procedure can be called several times, one for each network
12283 interface of interest. Behind the scenes what it does is extend
12284 @code{static-networking-service-type} with additional network interfaces
12290 (static-networking-service "eno1" "192.168.1.82"
12291 #:gateway "192.168.1.2"
12292 #:name-servers '("192.168.1.2"))
12299 @cindex network management
12300 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
12301 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
12302 management daemon that aims to simplify wired and wireless networking.
12304 This service adds the @var{wicd} package to the global profile, providing
12305 several commands to interact with the daemon and configure networking:
12306 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
12307 and @command{wicd-curses} user interfaces.
12310 @cindex ModemManager
12312 @defvr {Scheme Variable} modem-manager-service-type
12313 This is the service type for the
12314 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
12315 service. The value for this service type is a
12316 @code{modem-manager-configuration} record.
12318 This service is part of @code{%desktop-services} (@pxref{Desktop
12322 @deftp {Data Type} modem-manager-configuration
12323 Data type representing the configuration of ModemManager.
12326 @item @code{modem-manager} (default: @code{modem-manager})
12327 The ModemManager package to use.
12332 @cindex NetworkManager
12334 @defvr {Scheme Variable} network-manager-service-type
12335 This is the service type for the
12336 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
12337 service. The value for this service type is a
12338 @code{network-manager-configuration} record.
12340 This service is part of @code{%desktop-services} (@pxref{Desktop
12344 @deftp {Data Type} network-manager-configuration
12345 Data type representing the configuration of NetworkManager.
12348 @item @code{network-manager} (default: @code{network-manager})
12349 The NetworkManager package to use.
12351 @item @code{dns} (default: @code{"default"})
12352 Processing mode for DNS, which affects how NetworkManager uses the
12353 @code{resolv.conf} configuration file.
12357 NetworkManager will update @code{resolv.conf} to reflect the nameservers
12358 provided by currently active connections.
12361 NetworkManager will run @code{dnsmasq} as a local caching nameserver,
12362 using a "split DNS" configuration if you are connected to a VPN, and
12363 then update @code{resolv.conf} to point to the local nameserver.
12366 NetworkManager will not modify @code{resolv.conf}.
12369 @item @code{vpn-plugins} (default: @code{'()})
12370 This is the list of available plugins for virtual private networks
12371 (VPNs). An example of this is the @code{network-manager-openvpn}
12372 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
12378 @deffn {Scheme Variable} connman-service-type
12379 This is the service type to run @url{https://01.org/connman,Connman},
12380 a network connection manager.
12382 Its value must be an
12383 @code{connman-configuration} record as in this example:
12386 (service connman-service-type
12387 (connman-configuration
12388 (disable-vpn? #t)))
12391 See below for details about @code{connman-configuration}.
12394 @deftp {Data Type} connman-configuration
12395 Data Type representing the configuration of connman.
12398 @item @code{connman} (default: @var{connman})
12399 The connman package to use.
12401 @item @code{disable-vpn?} (default: @code{#f})
12402 When true, disable connman's vpn plugin.
12406 @cindex WPA Supplicant
12407 @defvr {Scheme Variable} wpa-supplicant-service-type
12408 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
12409 supplicant}, an authentication daemon required to authenticate against
12410 encrypted WiFi or ethernet networks.
12413 @deftp {Data Type} wpa-supplicant-configuration
12414 Data type representing the configuration of WPA Supplicant.
12416 It takes the following parameters:
12419 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
12420 The WPA Supplicant package to use.
12422 @item @code{dbus?} (default: @code{#t})
12423 Whether to listen for requests on D-Bus.
12425 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
12426 Where to store the PID file.
12428 @item @code{interface} (default: @code{#f})
12429 If this is set, it must specify the name of a network interface that
12430 WPA supplicant will control.
12432 @item @code{config-file} (default: @code{#f})
12433 Optional configuration file to use.
12435 @item @code{extra-options} (default: @code{'()})
12436 List of additional command-line arguments to pass to the daemon.
12441 @defvr {Scheme Variable} iptables-service-type
12442 This is the service type to set up an iptables configuration. iptables is a
12443 packet filtering framework supported by the Linux kernel. This service
12444 supports configuring iptables for both IPv4 and IPv6. A simple example
12445 configuration rejecting all incoming connections except those to the ssh port
12449 (service iptables-service-type
12450 (iptables-configuration
12451 (ipv4-rules (plain-file "iptables.rules" "*filter
12455 -A INPUT -p tcp --dport 22 -j ACCEPT
12456 -A INPUT -j REJECT --reject-with icmp-port-unreachable
12459 (ipv6-rules (plain-file "ip6tables.rules" "*filter
12463 -A INPUT -p tcp --dport 22 -j ACCEPT
12464 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
12470 @deftp {Data Type} iptables-configuration
12471 The data type representing the configuration of iptables.
12474 @item @code{iptables} (default: @code{iptables})
12475 The iptables package that provides @code{iptables-restore} and
12476 @code{ip6tables-restore}.
12477 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
12478 The iptables rules to use. It will be passed to @code{iptables-restore}.
12479 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12481 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
12482 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
12483 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12488 @cindex NTP (Network Time Protocol), service
12489 @cindex real time clock
12490 @defvr {Scheme Variable} ntp-service-type
12491 This is the type of the service running the @uref{http://www.ntp.org,
12492 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
12493 system clock synchronized with that of the specified NTP servers.
12495 The value of this service is an @code{ntpd-configuration} object, as described
12499 @deftp {Data Type} ntp-configuration
12500 This is the data type for the NTP service configuration.
12503 @item @code{servers} (default: @code{%ntp-servers})
12504 This is the list of servers (host names) with which @command{ntpd} will be
12507 @item @code{allow-large-adjustment?} (default: @code{#f})
12508 This determines whether @command{ntpd} is allowed to make an initial
12509 adjustment of more than 1,000 seconds.
12511 @item @code{ntp} (default: @code{ntp})
12512 The NTP package to use.
12516 @defvr {Scheme Variable} %ntp-servers
12517 List of host names used as the default NTP servers. These are servers of the
12518 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
12522 @deffn {Scheme Procedure} openntpd-service-type
12523 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
12524 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
12525 clock synchronized with that of the given servers.
12529 openntpd-service-type
12530 (openntpd-configuration
12531 (listen-on '("127.0.0.1" "::1"))
12532 (sensor '("udcf0 correction 70000"))
12533 (constraint-from '("www.gnu.org"))
12534 (constraints-from '("https://www.google.com/"))
12535 (allow-large-adjustment? #t)))
12540 @deftp {Data Type} openntpd-configuration
12542 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
12543 The openntpd executable to use.
12544 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
12545 A list of local IP addresses or hostnames the ntpd daemon should listen on.
12546 @item @code{query-from} (default: @code{'()})
12547 A list of local IP address the ntpd daemon should use for outgoing queries.
12548 @item @code{sensor} (default: @code{'()})
12549 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
12550 will listen to each sensor that acutally exists and ignore non-existant ones.
12551 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
12553 @item @code{server} (default: @var{%ntp-servers})
12554 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
12555 @item @code{servers} (default: @code{'()})
12556 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
12557 @item @code{constraint-from} (default: @code{'()})
12558 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
12559 This time information is not used for precision but acts as an authenticated
12560 constraint, thereby reducing the impact of unauthenticated NTP
12561 man-in-the-middle attacks.
12562 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
12564 @item @code{constraints-from} (default: @code{'()})
12565 As with constraint from, specify a list of URLs, IP addresses or hostnames of
12566 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
12567 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
12568 @item @code{allow-large-adjustment?} (default: @code{#f})
12569 Determines if @code{ntpd} is allowed to make an initial adjustment of more
12575 @deffn {Scheme variable} inetd-service-type
12576 This service runs the @command{inetd} (@pxref{inetd invocation,,,
12577 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
12578 connections on internet sockets, and lazily starts the specified server
12579 program when a connection is made on one of these sockets.
12581 The value of this service is an @code{inetd-configuration} object. The
12582 following example configures the @command{inetd} daemon to provide the
12583 built-in @command{echo} service, as well as an smtp service which
12584 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
12585 gateway @code{hostname}:
12590 (inetd-configuration
12594 (socket-type 'stream)
12601 (socket-type 'stream)
12605 (program (file-append openssh "/bin/ssh"))
12607 '("ssh" "-qT" "-i" "/path/to/ssh_key"
12608 "-W" "smtp-server:25" "user@@hostname")))))
12611 See below for more details about @code{inetd-configuration}.
12614 @deftp {Data Type} inetd-configuration
12615 Data type representing the configuration of @command{inetd}.
12618 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
12619 The @command{inetd} executable to use.
12621 @item @code{entries} (default: @code{'()})
12622 A list of @command{inetd} service entries. Each entry should be created
12623 by the @code{inetd-entry} constructor.
12627 @deftp {Data Type} inetd-entry
12628 Data type representing an entry in the @command{inetd} configuration.
12629 Each entry corresponds to a socket where @command{inetd} will listen for
12633 @item @code{node} (default: @code{#f})
12634 Optional string, a comma-separated list of local addresses
12635 @command{inetd} should use when listening for this service.
12636 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
12637 description of all options.
12639 A string, the name must correspond to an entry in @code{/etc/services}.
12640 @item @code{socket-type}
12641 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
12643 @item @code{protocol}
12644 A string, must correspond to an entry in @code{/etc/protocols}.
12645 @item @code{wait?} (default: @code{#t})
12646 Whether @command{inetd} should wait for the server to exit before
12647 listening to new service requests.
12649 A string containing the user (and, optionally, group) name of the user
12650 as whom the server should run. The group name can be specified in a
12651 suffix, separated by a colon or period, i.e.@: @code{"user"},
12652 @code{"user:group"} or @code{"user.group"}.
12653 @item @code{program} (default: @code{"internal"})
12654 The server program which will serve the requests, or @code{"internal"}
12655 if @command{inetd} should use a built-in service.
12656 @item @code{arguments} (default: @code{'()})
12657 A list strings or file-like objects, which are the server program's
12658 arguments, starting with the zeroth argument, i.e.@: the name of the
12659 program itself. For @command{inetd}'s internal services, this entry
12660 must be @code{'()} or @code{'("internal")}.
12663 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
12664 detailed discussion of each configuration field.
12668 @defvr {Scheme Variable} tor-service-type
12669 This is the type for a service that runs the @uref{https://torproject.org,
12670 Tor} anonymous networking daemon. The service is configured using a
12671 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
12672 @code{tor} unprivileged user, which is a member of the @code{tor} group.
12676 @deftp {Data Type} tor-configuration
12678 @item @code{tor} (default: @code{tor})
12679 The package that provides the Tor daemon. This package is expected to provide
12680 the daemon at @file{bin/tor} relative to its output directory. The default
12681 package is the @uref{https://www.torproject.org, Tor Project's}
12684 @item @code{config-file} (default: @code{(plain-file "empty" "")})
12685 The configuration file to use. It will be appended to a default configuration
12686 file, and the final configuration file will be passed to @code{tor} via its
12687 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
12688 file-like objects}). See @code{man tor} for details on the configuration file
12691 @item @code{hidden-services} (default: @code{'()})
12692 The list of @code{<hidden-service>} records to use. For any hidden service
12693 you include in this list, appropriate configuration to enable the hidden
12694 service will be automatically added to the default configuration file. You
12695 may conveniently create @code{<hidden-service>} records using the
12696 @code{tor-hidden-service} procedure described below.
12698 @item @code{socks-socket-type} (default: @code{'tcp})
12699 The default socket type that Tor should use for its SOCKS socket. This must
12700 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
12701 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
12702 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
12703 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
12706 If you want to customize the SOCKS socket in more detail, leave
12707 @code{socks-socket-type} at its default value of @code{'tcp} and use
12708 @code{config-file} to override the default by providing your own
12709 @code{SocksPort} option.
12713 @cindex hidden service
12714 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
12715 Define a new Tor @dfn{hidden service} called @var{name} and implementing
12716 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
12719 '((22 "127.0.0.1:22")
12720 (80 "127.0.0.1:8080"))
12723 In this example, port 22 of the hidden service is mapped to local port 22, and
12724 port 80 is mapped to local port 8080.
12726 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
12727 the @file{hostname} file contains the @code{.onion} host name for the hidden
12730 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
12731 project's documentation} for more information.
12734 The @code{(gnu services rsync)} module provides the following services:
12736 You might want an rsync daemon if you have files that you want available
12737 so anyone (or just yourself) can download existing files or upload new
12740 @deffn {Scheme Variable} rsync-service-type
12741 This is the type for the @uref{https://rsync.samba.org, rsync} rsync daemon,
12742 @command{rsync-configuration} record as in this example:
12745 (service rsync-service-type)
12748 See below for details about @code{rsync-configuration}.
12751 @deftp {Data Type} rsync-configuration
12752 Data type representing the configuration for @code{rsync-service}.
12755 @item @code{package} (default: @var{rsync})
12756 @code{rsync} package to use.
12758 @item @code{port-number} (default: @code{873})
12759 TCP port on which @command{rsync} listens for incoming connections. If port
12760 is less than @code{1024} @command{rsync} needs to be started as the
12761 @code{root} user and group.
12763 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
12764 Name of the file where @command{rsync} writes its PID.
12766 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
12767 Name of the file where @command{rsync} writes its lock file.
12769 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
12770 Name of the file where @command{rsync} writes its log file.
12772 @item @code{use-chroot?} (default: @var{#t})
12773 Whether to use chroot for @command{rsync} shared directory.
12775 @item @code{share-path} (default: @file{/srv/rsync})
12776 Location of the @command{rsync} shared directory.
12778 @item @code{share-comment} (default: @code{"Rsync share"})
12779 Comment of the @command{rsync} shared directory.
12781 @item @code{read-only?} (default: @var{#f})
12782 Read-write permissions to shared directory.
12784 @item @code{timeout} (default: @code{300})
12785 I/O timeout in seconds.
12787 @item @code{user} (default: @var{"root"})
12788 Owner of the @code{rsync} process.
12790 @item @code{group} (default: @var{"root"})
12791 Group of the @code{rsync} process.
12793 @item @code{uid} (default: @var{"rsyncd"})
12794 User name or user ID that file transfers to and from that module should take
12795 place as when the daemon was run as @code{root}.
12797 @item @code{gid} (default: @var{"rsyncd"})
12798 Group name or group ID that will be used when accessing the module.
12803 Furthermore, @code{(gnu services ssh)} provides the following services.
12807 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
12808 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
12809 [#:allow-empty-passwords? #f] [#:root-login? #f] @
12810 [#:syslog-output? #t] [#:x11-forwarding? #t] @
12811 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
12812 [#:public-key-authentication? #t] [#:initialize? #t]
12813 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
12814 @var{host-key} must designate a file containing the host key, and readable
12817 When @var{daemonic?} is true, @command{lshd} will detach from the
12818 controlling terminal and log its output to syslogd, unless one sets
12819 @var{syslog-output?} to false. Obviously, it also makes lsh-service
12820 depend on existence of syslogd service. When @var{pid-file?} is true,
12821 @command{lshd} writes its PID to the file called @var{pid-file}.
12823 When @var{initialize?} is true, automatically create the seed and host key
12824 upon service activation if they do not exist yet. This may take long and
12825 require interaction.
12827 When @var{initialize?} is false, it is up to the user to initialize the
12828 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
12829 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
12830 basics,,, lsh, LSH Manual}).
12832 When @var{interfaces} is empty, lshd listens for connections on all the
12833 network interfaces; otherwise, @var{interfaces} must be a list of host names
12836 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
12837 passwords, and @var{root-login?} specifies whether to accept log-ins as
12840 The other options should be self-descriptive.
12845 @deffn {Scheme Variable} openssh-service-type
12846 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
12847 shell daemon, @command{sshd}. Its value must be an
12848 @code{openssh-configuration} record as in this example:
12851 (service openssh-service-type
12852 (openssh-configuration
12853 (x11-forwarding? #t)
12854 (permit-root-login 'without-password)
12856 `(("alice" ,(local-file "alice.pub"))
12857 ("bob" ,(local-file "bob.pub"))))))
12860 See below for details about @code{openssh-configuration}.
12862 This service can be extended with extra authorized keys, as in this
12866 (service-extension openssh-service-type
12867 (const `(("charlie"
12868 ,(local-file "charlie.pub")))))
12872 @deftp {Data Type} openssh-configuration
12873 This is the configuration record for OpenSSH's @command{sshd}.
12876 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
12877 Name of the file where @command{sshd} writes its PID.
12879 @item @code{port-number} (default: @code{22})
12880 TCP port on which @command{sshd} listens for incoming connections.
12882 @item @code{permit-root-login} (default: @code{#f})
12883 This field determines whether and when to allow logins as root. If
12884 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
12885 If it's the symbol @code{'without-password}, then root logins are
12886 permitted but not with password-based authentication.
12888 @item @code{allow-empty-passwords?} (default: @code{#f})
12889 When true, users with empty passwords may log in. When false, they may
12892 @item @code{password-authentication?} (default: @code{#t})
12893 When true, users may log in with their password. When false, they have
12894 other authentication methods.
12896 @item @code{public-key-authentication?} (default: @code{#t})
12897 When true, users may log in using public key authentication. When
12898 false, users have to use other authentication method.
12900 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
12901 This is used only by protocol version 2.
12903 @item @code{x11-forwarding?} (default: @code{#f})
12904 When true, forwarding of X11 graphical client connections is
12905 enabled---in other words, @command{ssh} options @option{-X} and
12906 @option{-Y} will work.
12908 @item @code{allow-agent-forwarding?} (default: @code{#t})
12909 Whether to allow agent forwarding.
12911 @item @code{allow-tcp-forwarding?} (default: @code{#t})
12912 Whether to allow TCP forwarding.
12914 @item @code{gateway-ports?} (default: @code{#f})
12915 Whether to allow gateway ports.
12917 @item @code{challenge-response-authentication?} (default: @code{#f})
12918 Specifies whether challenge response authentication is allowed (e.g.@: via
12921 @item @code{use-pam?} (default: @code{#t})
12922 Enables the Pluggable Authentication Module interface. If set to
12923 @code{#t}, this will enable PAM authentication using
12924 @code{challenge-response-authentication?} and
12925 @code{password-authentication?}, in addition to PAM account and session
12926 module processing for all authentication types.
12928 Because PAM challenge response authentication usually serves an
12929 equivalent role to password authentication, you should disable either
12930 @code{challenge-response-authentication?} or
12931 @code{password-authentication?}.
12933 @item @code{print-last-log?} (default: @code{#t})
12934 Specifies whether @command{sshd} should print the date and time of the
12935 last user login when a user logs in interactively.
12937 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
12938 Configures external subsystems (e.g.@: file transfer daemon).
12940 This is a list of two-element lists, each of which containing the
12941 subsystem name and a command (with optional arguments) to execute upon
12944 The command @command{internal-sftp} implements an in-process SFTP
12945 server. Alternately, one can specify the @command{sftp-server} command:
12947 (service openssh-service-type
12948 (openssh-configuration
12950 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
12953 @item @code{accepted-environment} (default: @code{'()})
12954 List of strings describing which environment variables may be exported.
12956 Each string gets on its own line. See the @code{AcceptEnv} option in
12957 @code{man sshd_config}.
12959 This example allows ssh-clients to export the @code{COLORTERM} variable.
12960 It is set by terminal emulators, which support colors. You can use it in
12961 your shell's ressource file to enable colors for the prompt and commands
12962 if this variable is set.
12965 (service openssh-service-type
12966 (openssh-configuration
12967 (accepted-environment '("COLORTERM"))))
12970 @item @code{authorized-keys} (default: @code{'()})
12971 @cindex authorized keys, SSH
12972 @cindex SSH authorized keys
12973 This is the list of authorized keys. Each element of the list is a user
12974 name followed by one or more file-like objects that represent SSH public
12978 (openssh-configuration
12980 `(("rekado" ,(local-file "rekado.pub"))
12981 ("chris" ,(local-file "chris.pub"))
12982 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
12986 registers the specified public keys for user accounts @code{rekado},
12987 @code{chris}, and @code{root}.
12989 Additional authorized keys can be specified @i{via}
12990 @code{service-extension}.
12992 Note that this does @emph{not} interfere with the use of
12993 @file{~/.ssh/authorized_keys}.
12995 @item @code{log-level} (default: @code{'info})
12996 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
12997 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
12998 page for @file{sshd_config} for the full list of level names.
13000 @item @code{extra-content} (default: @code{""})
13001 This field can be used to append arbitrary text to the configuration file. It
13002 is especially useful for elaborate configurations that cannot be expressed
13003 otherwise. This configuration, for example, would generally disable root
13004 logins, but permit them from one specific IP address:
13007 (openssh-configuration
13009 Match Address 192.168.0.1
13010 PermitRootLogin yes"))
13016 @deffn {Scheme Procedure} dropbear-service [@var{config}]
13017 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
13018 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
13021 For example, to specify a Dropbear service listening on port 1234, add
13022 this call to the operating system's @code{services} field:
13025 (dropbear-service (dropbear-configuration
13026 (port-number 1234)))
13030 @deftp {Data Type} dropbear-configuration
13031 This data type represents the configuration of a Dropbear SSH daemon.
13034 @item @code{dropbear} (default: @var{dropbear})
13035 The Dropbear package to use.
13037 @item @code{port-number} (default: 22)
13038 The TCP port where the daemon waits for incoming connections.
13040 @item @code{syslog-output?} (default: @code{#t})
13041 Whether to enable syslog output.
13043 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
13044 File name of the daemon's PID file.
13046 @item @code{root-login?} (default: @code{#f})
13047 Whether to allow @code{root} logins.
13049 @item @code{allow-empty-passwords?} (default: @code{#f})
13050 Whether to allow empty passwords.
13052 @item @code{password-authentication?} (default: @code{#t})
13053 Whether to enable password-based authentication.
13057 @defvr {Scheme Variable} %facebook-host-aliases
13058 This variable contains a string for use in @file{/etc/hosts}
13059 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
13060 line contains a entry that maps a known server name of the Facebook
13061 on-line service---e.g., @code{www.facebook.com}---to the local
13062 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
13064 This variable is typically used in the @code{hosts-file} field of an
13065 @code{operating-system} declaration (@pxref{operating-system Reference,
13066 @file{/etc/hosts}}):
13069 (use-modules (gnu) (guix))
13072 (host-name "mymachine")
13075 ;; Create a /etc/hosts file with aliases for "localhost"
13076 ;; and "mymachine", as well as for Facebook servers.
13077 (plain-file "hosts"
13078 (string-append (local-host-aliases host-name)
13079 %facebook-host-aliases))))
13082 This mechanism can prevent programs running locally, such as Web
13083 browsers, from accessing Facebook.
13086 The @code{(gnu services avahi)} provides the following definition.
13088 @defvr {Scheme Variable} avahi-service-type
13089 This is the service that runs @command{avahi-daemon}, a system-wide
13090 mDNS/DNS-SD responder that allows for service discovery and
13091 ``zero-configuration'' host name lookups (see @uref{http://avahi.org/}).
13092 Its value must be a @code{zero-configuration} record---see below.
13094 This service extends the name service cache daemon (nscd) so that it can
13095 resolve @code{.local} host names using
13096 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
13097 Service Switch}, for information on host name resolution.
13099 Additionally, add the @var{avahi} package to the system profile so that
13100 commands such as @command{avahi-browse} are directly usable.
13103 @deftp {Data Type} avahi-configuration
13104 Data type representation the configuration for Avahi.
13108 @item @code{host-name} (default: @code{#f})
13109 If different from @code{#f}, use that as the host name to
13110 publish for this machine; otherwise, use the machine's actual host name.
13112 @item @code{publish?} (default: @code{#t})
13113 When true, allow host names and services to be published (broadcast) over the
13116 @item @code{publish-workstation?} (default: @code{#t})
13117 When true, @command{avahi-daemon} publishes the machine's host name and IP
13118 address via mDNS on the local network. To view the host names published on
13119 your local network, you can run:
13122 avahi-browse _workstation._tcp
13125 @item @code{wide-area?} (default: @code{#f})
13126 When true, DNS-SD over unicast DNS is enabled.
13128 @item @code{ipv4?} (default: @code{#t})
13129 @itemx @code{ipv6?} (default: @code{#t})
13130 These fields determine whether to use IPv4/IPv6 sockets.
13132 @item @code{domains-to-browse} (default: @code{'()})
13133 This is a list of domains to browse.
13137 @deffn {Scheme Variable} openvswitch-service-type
13138 This is the type of the @uref{http://www.openvswitch.org, Open vSwitch}
13139 service, whose value should be an @code{openvswitch-configuration}
13143 @deftp {Data Type} openvswitch-configuration
13144 Data type representing the configuration of Open vSwitch, a multilayer
13145 virtual switch which is designed to enable massive network automation
13146 through programmatic extension.
13149 @item @code{package} (default: @var{openvswitch})
13150 Package object of the Open vSwitch.
13156 @subsection X Window
13159 @cindex X Window System
13160 @cindex login manager
13161 Support for the X Window graphical display system---specifically
13162 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
13163 there is no @code{xorg-service} procedure. Instead, the X server is
13164 started by the @dfn{login manager}, by default SLiM.
13166 @cindex window manager
13167 To use X11, you must install at least one @dfn{window manager}---for
13168 example the @code{windowmaker} or @code{openbox} packages---preferably
13169 by adding it to the @code{packages} field of your operating system
13170 definition (@pxref{operating-system Reference, system-wide packages}).
13172 @defvr {Scheme Variable} slim-service-type
13173 This is the type for the SLiM graphical login manager for X11.
13175 @cindex session types (X11)
13176 @cindex X11 session types
13177 SLiM looks for @dfn{session types} described by the @file{.desktop} files in
13178 @file{/run/current-system/profile/share/xsessions} and allows users to
13179 choose a session from the log-in screen using @kbd{F1}. Packages such
13180 as @code{xfce}, @code{sawfish}, and @code{ratpoison} provide
13181 @file{.desktop} files; adding them to the system-wide set of packages
13182 automatically makes them available at the log-in screen.
13184 In addition, @file{~/.xsession} files are honored. When available,
13185 @file{~/.xsession} must be an executable that starts a window manager
13186 and/or other X clients.
13189 @deftp {Data Type} slim-configuration
13190 Data type representing the configuration of @code{slim-service-type}.
13193 @item @code{allow-empty-passwords?} (default: @code{#t})
13194 Whether to allow logins with empty passwords.
13196 @item @code{auto-login?} (default: @code{#f})
13197 @itemx @code{default-user} (default: @code{""})
13198 When @code{auto-login?} is false, SLiM presents a log-in screen.
13200 When @code{auto-login?} is true, SLiM logs in directly as
13201 @code{default-user}.
13203 @item @code{theme} (default: @code{%default-slim-theme})
13204 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
13205 The graphical theme to use and its name.
13207 @item @code{auto-login-session} (default: @code{#f})
13208 If true, this must be the name of the executable to start as the default
13209 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
13211 If false, a session described by one of the available @file{.desktop}
13212 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
13216 You must install at least one window manager in the system profile or in
13217 your user profile. Failing to do that, if @code{auto-login-session} is
13218 false, you will be unable to log in.
13221 @item @code{startx} (default: @code{(xorg-start-command)})
13222 The command used to start the X11 graphical server.
13224 @item @code{xauth} (default: @code{xauth})
13225 The XAuth package to use.
13227 @item @code{shepherd} (default: @code{shepherd})
13228 The Shepherd package used when invoking @command{halt} and
13231 @item @code{sessreg} (default: @code{sessreg})
13232 The sessreg package used in order to register the session.
13234 @item @code{slim} (default: @code{slim})
13235 The SLiM package to use.
13239 @defvr {Scheme Variable} %default-theme
13240 @defvrx {Scheme Variable} %default-theme-name
13241 The default SLiM theme and its name.
13245 @deftp {Data Type} sddm-configuration
13246 This is the data type representing the sddm service configuration.
13249 @item @code{display-server} (default: "x11")
13250 Select display server to use for the greeter. Valid values are "x11"
13253 @item @code{numlock} (default: "on")
13254 Valid values are "on", "off" or "none".
13256 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
13257 Command to run when halting.
13259 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
13260 Command to run when rebooting.
13262 @item @code{theme} (default "maldives")
13263 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
13265 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
13266 Directory to look for themes.
13268 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
13269 Directory to look for faces.
13271 @item @code{default-path} (default "/run/current-system/profile/bin")
13272 Default PATH to use.
13274 @item @code{minimum-uid} (default 1000)
13275 Minimum UID to display in SDDM.
13277 @item @code{maximum-uid} (default 2000)
13278 Maximum UID to display in SDDM
13280 @item @code{remember-last-user?} (default #t)
13281 Remember last user.
13283 @item @code{remember-last-session?} (default #t)
13284 Remember last session.
13286 @item @code{hide-users} (default "")
13287 Usernames to hide from SDDM greeter.
13289 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
13290 Users with shells listed will be hidden from the SDDM greeter.
13292 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
13293 Script to run before starting a wayland session.
13295 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
13296 Directory to look for desktop files starting wayland sessions.
13298 @item @code{xorg-server-path} (default @code{xorg-start-command})
13299 Path to xorg-server.
13301 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
13304 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
13307 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
13308 Script to run after starting xorg-server.
13310 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
13311 Script to run before stopping xorg-server.
13313 @item @code{xsession-command} (default: @code{xinitrc})
13314 Script to run before starting a X session.
13316 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
13317 Directory to look for desktop files starting X sessions.
13319 @item @code{minimum-vt} (default: 7)
13322 @item @code{xserver-arguments} (default "-nolisten tcp")
13323 Arguments to pass to xorg-server.
13325 @item @code{auto-login-user} (default "")
13326 User to use for auto-login.
13328 @item @code{auto-login-session} (default "")
13329 Desktop file to use for auto-login.
13331 @item @code{relogin?} (default #f)
13332 Relogin after logout.
13337 @cindex login manager
13339 @deffn {Scheme Procedure} sddm-service config
13340 Return a service that spawns the SDDM graphical login manager for config of
13341 type @code{<sddm-configuration>}.
13344 (sddm-service (sddm-configuration
13345 (auto-login-user "Alice")
13346 (auto-login-session "xfce.desktop")))
13350 @deffn {Scheme Procedure} xorg-start-command [#:guile] @
13351 [#:modules %default-xorg-modules] @
13352 [#:fonts %default-xorg-fonts] @
13353 [#:configuration-file (xorg-configuration-file @dots{})] @
13354 [#:xorg-server @var{xorg-server}]
13355 [#:xserver-arguments '("-nolisten" "tcp")]
13356 Return a @code{startx} script in which @var{modules}, a list of X module
13357 packages, and @var{fonts}, a list of X font directories, are available. See
13358 @code{xorg-wrapper} for more details on the arguments. The result should be
13359 used in place of @code{startx}.
13361 Usually the X server is started by a login manager.
13364 @cindex @code{-listen tcp}, for X11.
13365 This procedure is useful to override command line options for the X server,
13366 such as having it listen to over TCP:
13372 (modify-services %desktop-services
13373 (slim-service-type config =>
13374 (slim-configuration
13376 (startx (xorg-start-command
13377 #:xserver-arguments '("-listen" "tcp"))))))))
13380 @deffn {Scheme Procedure} xorg-configuration-file @
13381 [#:modules %default-xorg-modules] @
13382 [#:fonts %default-xorg-fonts] @
13383 [#:drivers '()] [#:resolutions '()] [#:extra-config '()]
13384 Return a configuration file for the Xorg server containing search paths for
13385 all the common drivers.
13387 @var{modules} must be a list of @dfn{module packages} loaded by the Xorg
13388 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
13389 @var{fonts} must be a list of font directories to add to the server's
13392 @var{drivers} must be either the empty list, in which case Xorg chooses a
13393 graphics driver automatically, or a list of driver names that will be tried in
13394 this order---e.g., @code{("modesetting" "vesa")}.
13396 Likewise, when @var{resolutions} is the empty list, Xorg chooses an
13397 appropriate screen resolution; otherwise, it must be a list of
13398 resolutions---e.g., @code{((1024 768) (640 480))}.
13400 Last, @var{extra-config} is a list of strings or objects appended to the
13401 configuration file. It is used to pass extra text to be
13402 added verbatim to the configuration file.
13405 @cindex keyboard layout
13406 This procedure is especially useful to configure a different keyboard layout
13407 than the default US keymap. For instance, to use the ``bépo'' keymap by
13408 default on the display manager:
13412 "Section \"InputClass\"
13413 Identifier \"evdev keyboard catchall\"
13415 MatchIsKeyboard \"on\"
13416 Option \"xkb_layout\" \"fr\"
13417 Option \"xkb_variant\" \"bepo\"
13423 (modify-services %desktop-services
13424 (slim-service-type config =>
13425 (slim-configuration
13427 (startx (xorg-start-command
13428 #:configuration-file
13429 (xorg-configuration-file
13431 (list bepo-evdev)))))))))
13434 The @code{MatchIsKeyboard} line specifies that we only apply the configuration
13435 to keyboards. Without this line, other devices such as touchpad may not work
13436 correctly because they will be attached to the wrong driver. In this example,
13437 the user typically used @code{setxkbmap fr bepo} to set their favorite keymap
13438 once logged in. The first argument corresponds to the layout, while the second
13439 argument corresponds to the variant. The @code{xkb_variant} line can be omitted
13440 to select the default variant.
13443 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
13444 Add @var{package}, a package for a screen locker or screen saver whose
13445 command is @var{program}, to the set of setuid programs and add a PAM entry
13446 for it. For example:
13449 (screen-locker-service xlockmore "xlock")
13452 makes the good ol' XlockMore usable.
13456 @node Printing Services
13457 @subsection Printing Services
13459 @cindex printer support with CUPS
13460 The @code{(gnu services cups)} module provides a Guix service definition
13461 for the CUPS printing service. To add printer support to a Guix
13462 system, add a @code{cups-service} to the operating system definition:
13464 @deffn {Scheme Variable} cups-service-type
13465 The service type for the CUPS print server. Its value should be a valid
13466 CUPS configuration (see below). To use the default settings, simply
13469 (service cups-service-type)
13473 The CUPS configuration controls the basic things about your CUPS
13474 installation: what interfaces it listens on, what to do if a print job
13475 fails, how much logging to do, and so on. To actually add a printer,
13476 you have to visit the @url{http://localhost:631} URL, or use a tool such
13477 as GNOME's printer configuration services. By default, configuring a
13478 CUPS service will generate a self-signed certificate if needed, for
13479 secure connections to the print server.
13481 Suppose you want to enable the Web interface of CUPS and also add
13482 support for Epson printers @i{via} the @code{escpr} package and for HP
13483 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
13484 like this (you need to use the @code{(gnu packages cups)} module):
13487 (service cups-service-type
13488 (cups-configuration
13489 (web-interface? #t)
13491 (list cups-filters escpr hplip-minimal))))
13494 Note: If you wish to use the Qt5 based GUI which comes with the hplip
13495 package then it is suggested that you install the @code{hplip} package,
13496 either in your OS configuration file or as your user.
13498 The available configuration parameters follow. Each parameter
13499 definition is preceded by its type; for example, @samp{string-list foo}
13500 indicates that the @code{foo} parameter should be specified as a list of
13501 strings. There is also a way to specify the configuration as a string,
13502 if you have an old @code{cupsd.conf} file that you want to port over
13503 from some other system; see the end for more details.
13505 @c The following documentation was initially generated by
13506 @c (generate-documentation) in (gnu services cups). Manually maintained
13507 @c documentation is better, so we shouldn't hesitate to edit below as
13508 @c needed. However if the change you want to make to this documentation
13509 @c can be done in an automated way, it's probably easier to change
13510 @c (generate-documentation) than to make it below and have to deal with
13511 @c the churn as CUPS updates.
13514 Available @code{cups-configuration} fields are:
13516 @deftypevr {@code{cups-configuration} parameter} package cups
13520 @deftypevr {@code{cups-configuration} parameter} package-list extensions
13521 Drivers and other extensions to the CUPS package.
13524 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
13525 Configuration of where to write logs, what directories to use for print
13526 spools, and related privileged configuration parameters.
13528 Available @code{files-configuration} fields are:
13530 @deftypevr {@code{files-configuration} parameter} log-location access-log
13531 Defines the access log filename. Specifying a blank filename disables
13532 access log generation. The value @code{stderr} causes log entries to be
13533 sent to the standard error file when the scheduler is running in the
13534 foreground, or to the system log daemon when run in the background. The
13535 value @code{syslog} causes log entries to be sent to the system log
13536 daemon. The server name may be included in filenames using the string
13537 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
13539 Defaults to @samp{"/var/log/cups/access_log"}.
13542 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
13543 Where CUPS should cache data.
13545 Defaults to @samp{"/var/cache/cups"}.
13548 @deftypevr {@code{files-configuration} parameter} string config-file-perm
13549 Specifies the permissions for all configuration files that the scheduler
13552 Note that the permissions for the printers.conf file are currently
13553 masked to only allow access from the scheduler user (typically root).
13554 This is done because printer device URIs sometimes contain sensitive
13555 authentication information that should not be generally known on the
13556 system. There is no way to disable this security feature.
13558 Defaults to @samp{"0640"}.
13561 @deftypevr {@code{files-configuration} parameter} log-location error-log
13562 Defines the error log filename. Specifying a blank filename disables
13563 access log generation. The value @code{stderr} causes log entries to be
13564 sent to the standard error file when the scheduler is running in the
13565 foreground, or to the system log daemon when run in the background. The
13566 value @code{syslog} causes log entries to be sent to the system log
13567 daemon. The server name may be included in filenames using the string
13568 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
13570 Defaults to @samp{"/var/log/cups/error_log"}.
13573 @deftypevr {@code{files-configuration} parameter} string fatal-errors
13574 Specifies which errors are fatal, causing the scheduler to exit. The
13579 No errors are fatal.
13582 All of the errors below are fatal.
13585 Browsing initialization errors are fatal, for example failed connections
13586 to the DNS-SD daemon.
13589 Configuration file syntax errors are fatal.
13592 Listen or Port errors are fatal, except for IPv6 failures on the
13593 loopback or @code{any} addresses.
13596 Log file creation or write errors are fatal.
13599 Bad startup file permissions are fatal, for example shared TLS
13600 certificate and key files with world-read permissions.
13603 Defaults to @samp{"all -browse"}.
13606 @deftypevr {@code{files-configuration} parameter} boolean file-device?
13607 Specifies whether the file pseudo-device can be used for new printer
13608 queues. The URI @uref{file:///dev/null} is always allowed.
13610 Defaults to @samp{#f}.
13613 @deftypevr {@code{files-configuration} parameter} string group
13614 Specifies the group name or ID that will be used when executing external
13617 Defaults to @samp{"lp"}.
13620 @deftypevr {@code{files-configuration} parameter} string log-file-perm
13621 Specifies the permissions for all log files that the scheduler writes.
13623 Defaults to @samp{"0644"}.
13626 @deftypevr {@code{files-configuration} parameter} log-location page-log
13627 Defines the page log filename. Specifying a blank filename disables
13628 access log generation. The value @code{stderr} causes log entries to be
13629 sent to the standard error file when the scheduler is running in the
13630 foreground, or to the system log daemon when run in the background. The
13631 value @code{syslog} causes log entries to be sent to the system log
13632 daemon. The server name may be included in filenames using the string
13633 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
13635 Defaults to @samp{"/var/log/cups/page_log"}.
13638 @deftypevr {@code{files-configuration} parameter} string remote-root
13639 Specifies the username that is associated with unauthenticated accesses
13640 by clients claiming to be the root user. The default is @code{remroot}.
13642 Defaults to @samp{"remroot"}.
13645 @deftypevr {@code{files-configuration} parameter} file-name request-root
13646 Specifies the directory that contains print jobs and other HTTP request
13649 Defaults to @samp{"/var/spool/cups"}.
13652 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
13653 Specifies the level of security sandboxing that is applied to print
13654 filters, backends, and other child processes of the scheduler; either
13655 @code{relaxed} or @code{strict}. This directive is currently only
13656 used/supported on macOS.
13658 Defaults to @samp{strict}.
13661 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
13662 Specifies the location of TLS certificates and private keys. CUPS will
13663 look for public and private keys in this directory: a @code{.crt} files
13664 for PEM-encoded certificates and corresponding @code{.key} files for
13665 PEM-encoded private keys.
13667 Defaults to @samp{"/etc/cups/ssl"}.
13670 @deftypevr {@code{files-configuration} parameter} file-name server-root
13671 Specifies the directory containing the server configuration files.
13673 Defaults to @samp{"/etc/cups"}.
13676 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
13677 Specifies whether the scheduler calls fsync(2) after writing
13678 configuration or state files.
13680 Defaults to @samp{#f}.
13683 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
13684 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
13687 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
13688 Specifies the directory where temporary files are stored.
13690 Defaults to @samp{"/var/spool/cups/tmp"}.
13693 @deftypevr {@code{files-configuration} parameter} string user
13694 Specifies the user name or ID that is used when running external
13697 Defaults to @samp{"lp"}.
13701 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
13702 Specifies the logging level for the AccessLog file. The @code{config}
13703 level logs when printers and classes are added, deleted, or modified and
13704 when configuration files are accessed or updated. The @code{actions}
13705 level logs when print jobs are submitted, held, released, modified, or
13706 canceled, and any of the conditions for @code{config}. The @code{all}
13707 level logs all requests.
13709 Defaults to @samp{actions}.
13712 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
13713 Specifies whether to purge job history data automatically when it is no
13714 longer required for quotas.
13716 Defaults to @samp{#f}.
13719 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
13720 Specifies which protocols to use for local printer sharing.
13722 Defaults to @samp{dnssd}.
13725 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
13726 Specifies whether the CUPS web interface is advertised.
13728 Defaults to @samp{#f}.
13731 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
13732 Specifies whether shared printers are advertised.
13734 Defaults to @samp{#f}.
13737 @deftypevr {@code{cups-configuration} parameter} string classification
13738 Specifies the security classification of the server. Any valid banner
13739 name can be used, including "classified", "confidential", "secret",
13740 "topsecret", and "unclassified", or the banner can be omitted to disable
13741 secure printing functions.
13743 Defaults to @samp{""}.
13746 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
13747 Specifies whether users may override the classification (cover page) of
13748 individual print jobs using the @code{job-sheets} option.
13750 Defaults to @samp{#f}.
13753 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
13754 Specifies the default type of authentication to use.
13756 Defaults to @samp{Basic}.
13759 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
13760 Specifies whether encryption will be used for authenticated requests.
13762 Defaults to @samp{Required}.
13765 @deftypevr {@code{cups-configuration} parameter} string default-language
13766 Specifies the default language to use for text and web content.
13768 Defaults to @samp{"en"}.
13771 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
13772 Specifies the default paper size for new print queues. @samp{"Auto"}
13773 uses a locale-specific default, while @samp{"None"} specifies there is
13774 no default paper size. Specific size names are typically
13775 @samp{"Letter"} or @samp{"A4"}.
13777 Defaults to @samp{"Auto"}.
13780 @deftypevr {@code{cups-configuration} parameter} string default-policy
13781 Specifies the default access policy to use.
13783 Defaults to @samp{"default"}.
13786 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
13787 Specifies whether local printers are shared by default.
13789 Defaults to @samp{#t}.
13792 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
13793 Specifies the delay for updating of configuration and state files, in
13794 seconds. A value of 0 causes the update to happen as soon as possible,
13795 typically within a few milliseconds.
13797 Defaults to @samp{30}.
13800 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
13801 Specifies what to do when an error occurs. Possible values are
13802 @code{abort-job}, which will discard the failed print job;
13803 @code{retry-job}, which will retry the job at a later time;
13804 @code{retry-this-job}, which retries the failed job immediately; and
13805 @code{stop-printer}, which stops the printer.
13807 Defaults to @samp{stop-printer}.
13810 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
13811 Specifies the maximum cost of filters that are run concurrently, which
13812 can be used to minimize disk, memory, and CPU resource problems. A
13813 limit of 0 disables filter limiting. An average print to a
13814 non-PostScript printer needs a filter limit of about 200. A PostScript
13815 printer needs about half that (100). Setting the limit below these
13816 thresholds will effectively limit the scheduler to printing a single job
13819 Defaults to @samp{0}.
13822 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
13823 Specifies the scheduling priority of filters that are run to print a
13824 job. The nice value ranges from 0, the highest priority, to 19, the
13827 Defaults to @samp{0}.
13830 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
13831 Specifies whether to do reverse lookups on connecting clients. The
13832 @code{double} setting causes @code{cupsd} to verify that the hostname
13833 resolved from the address matches one of the addresses returned for that
13834 hostname. Double lookups also prevent clients with unregistered
13835 addresses from connecting to your server. Only set this option to
13836 @code{#t} or @code{double} if absolutely required.
13838 Defaults to @samp{#f}.
13841 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
13842 Specifies the number of seconds to wait before killing the filters and
13843 backend associated with a canceled or held job.
13845 Defaults to @samp{30}.
13848 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
13849 Specifies the interval between retries of jobs in seconds. This is
13850 typically used for fax queues but can also be used with normal print
13851 queues whose error policy is @code{retry-job} or
13852 @code{retry-current-job}.
13854 Defaults to @samp{30}.
13857 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
13858 Specifies the number of retries that are done for jobs. This is
13859 typically used for fax queues but can also be used with normal print
13860 queues whose error policy is @code{retry-job} or
13861 @code{retry-current-job}.
13863 Defaults to @samp{5}.
13866 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
13867 Specifies whether to support HTTP keep-alive connections.
13869 Defaults to @samp{#t}.
13872 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
13873 Specifies how long an idle client connection remains open, in seconds.
13875 Defaults to @samp{30}.
13878 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
13879 Specifies the maximum size of print files, IPP requests, and HTML form
13880 data. A limit of 0 disables the limit check.
13882 Defaults to @samp{0}.
13885 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
13886 Listens on the specified interfaces for connections. Valid values are
13887 of the form @var{address}:@var{port}, where @var{address} is either an
13888 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
13889 indicate all addresses. Values can also be file names of local UNIX
13890 domain sockets. The Listen directive is similar to the Port directive
13891 but allows you to restrict access to specific interfaces or networks.
13894 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
13895 Specifies the number of pending connections that will be allowed. This
13896 normally only affects very busy servers that have reached the MaxClients
13897 limit, but can also be triggered by large numbers of simultaneous
13898 connections. When the limit is reached, the operating system will
13899 refuse additional connections until the scheduler can accept the pending
13902 Defaults to @samp{128}.
13905 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
13906 Specifies a set of additional access controls.
13908 Available @code{location-access-controls} fields are:
13910 @deftypevr {@code{location-access-controls} parameter} file-name path
13911 Specifies the URI path to which the access control applies.
13914 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
13915 Access controls for all access to this path, in the same format as the
13916 @code{access-controls} of @code{operation-access-control}.
13918 Defaults to @samp{()}.
13921 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
13922 Access controls for method-specific access to this path.
13924 Defaults to @samp{()}.
13926 Available @code{method-access-controls} fields are:
13928 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
13929 If @code{#t}, apply access controls to all methods except the listed
13930 methods. Otherwise apply to only the listed methods.
13932 Defaults to @samp{#f}.
13935 @deftypevr {@code{method-access-controls} parameter} method-list methods
13936 Methods to which this access control applies.
13938 Defaults to @samp{()}.
13941 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
13942 Access control directives, as a list of strings. Each string should be
13943 one directive, such as "Order allow,deny".
13945 Defaults to @samp{()}.
13950 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
13951 Specifies the number of debugging messages that are retained for logging
13952 if an error occurs in a print job. Debug messages are logged regardless
13953 of the LogLevel setting.
13955 Defaults to @samp{100}.
13958 @deftypevr {@code{cups-configuration} parameter} log-level log-level
13959 Specifies the level of logging for the ErrorLog file. The value
13960 @code{none} stops all logging while @code{debug2} logs everything.
13962 Defaults to @samp{info}.
13965 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
13966 Specifies the format of the date and time in the log files. The value
13967 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
13969 Defaults to @samp{standard}.
13972 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
13973 Specifies the maximum number of simultaneous clients that are allowed by
13976 Defaults to @samp{100}.
13979 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
13980 Specifies the maximum number of simultaneous clients that are allowed
13981 from a single address.
13983 Defaults to @samp{100}.
13986 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
13987 Specifies the maximum number of copies that a user can print of each
13990 Defaults to @samp{9999}.
13993 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
13994 Specifies the maximum time a job may remain in the @code{indefinite}
13995 hold state before it is canceled. A value of 0 disables cancellation of
13998 Defaults to @samp{0}.
14001 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
14002 Specifies the maximum number of simultaneous jobs that are allowed. Set
14003 to 0 to allow an unlimited number of jobs.
14005 Defaults to @samp{500}.
14008 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
14009 Specifies the maximum number of simultaneous jobs that are allowed per
14010 printer. A value of 0 allows up to MaxJobs jobs per printer.
14012 Defaults to @samp{0}.
14015 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
14016 Specifies the maximum number of simultaneous jobs that are allowed per
14017 user. A value of 0 allows up to MaxJobs jobs per user.
14019 Defaults to @samp{0}.
14022 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
14023 Specifies the maximum time a job may take to print before it is
14024 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
14026 Defaults to @samp{10800}.
14029 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
14030 Specifies the maximum size of the log files before they are rotated, in
14031 bytes. The value 0 disables log rotation.
14033 Defaults to @samp{1048576}.
14036 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
14037 Specifies the maximum amount of time to allow between files in a
14038 multiple file print job, in seconds.
14040 Defaults to @samp{300}.
14043 @deftypevr {@code{cups-configuration} parameter} string page-log-format
14044 Specifies the format of PageLog lines. Sequences beginning with percent
14045 (@samp{%}) characters are replaced with the corresponding information,
14046 while all other characters are copied literally. The following percent
14047 sequences are recognized:
14051 insert a single percent character
14054 insert the value of the specified IPP attribute
14057 insert the number of copies for the current page
14060 insert the current page number
14063 insert the current date and time in common log format
14069 insert the printer name
14072 insert the username
14075 A value of the empty string disables page logging. The string @code{%p
14076 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
14077 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
14080 Defaults to @samp{""}.
14083 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
14084 Passes the specified environment variable(s) to child processes; a list
14087 Defaults to @samp{()}.
14090 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
14091 Specifies named access control policies.
14093 Available @code{policy-configuration} fields are:
14095 @deftypevr {@code{policy-configuration} parameter} string name
14096 Name of the policy.
14099 @deftypevr {@code{policy-configuration} parameter} string job-private-access
14100 Specifies an access list for a job's private values. @code{@@ACL} maps
14101 to the printer's requesting-user-name-allowed or
14102 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14103 owner. @code{@@SYSTEM} maps to the groups listed for the
14104 @code{system-group} field of the @code{files-config} configuration,
14105 which is reified into the @code{cups-files.conf(5)} file. Other
14106 possible elements of the access list include specific user names, and
14107 @code{@@@var{group}} to indicate members of a specific group. The
14108 access list may also be simply @code{all} or @code{default}.
14110 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14113 @deftypevr {@code{policy-configuration} parameter} string job-private-values
14114 Specifies the list of job values to make private, or @code{all},
14115 @code{default}, or @code{none}.
14117 Defaults to @samp{"job-name job-originating-host-name
14118 job-originating-user-name phone"}.
14121 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
14122 Specifies an access list for a subscription's private values.
14123 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
14124 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14125 owner. @code{@@SYSTEM} maps to the groups listed for the
14126 @code{system-group} field of the @code{files-config} configuration,
14127 which is reified into the @code{cups-files.conf(5)} file. Other
14128 possible elements of the access list include specific user names, and
14129 @code{@@@var{group}} to indicate members of a specific group. The
14130 access list may also be simply @code{all} or @code{default}.
14132 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14135 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
14136 Specifies the list of job values to make private, or @code{all},
14137 @code{default}, or @code{none}.
14139 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
14140 notify-subscriber-user-name notify-user-data"}.
14143 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
14144 Access control by IPP operation.
14146 Defaults to @samp{()}.
14150 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
14151 Specifies whether job files (documents) are preserved after a job is
14152 printed. If a numeric value is specified, job files are preserved for
14153 the indicated number of seconds after printing. Otherwise a boolean
14154 value applies indefinitely.
14156 Defaults to @samp{86400}.
14159 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
14160 Specifies whether the job history is preserved after a job is printed.
14161 If a numeric value is specified, the job history is preserved for the
14162 indicated number of seconds after printing. If @code{#t}, the job
14163 history is preserved until the MaxJobs limit is reached.
14165 Defaults to @samp{#t}.
14168 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
14169 Specifies the amount of time to wait for job completion before
14170 restarting the scheduler.
14172 Defaults to @samp{30}.
14175 @deftypevr {@code{cups-configuration} parameter} string rip-cache
14176 Specifies the maximum amount of memory to use when converting documents
14177 into bitmaps for a printer.
14179 Defaults to @samp{"128m"}.
14182 @deftypevr {@code{cups-configuration} parameter} string server-admin
14183 Specifies the email address of the server administrator.
14185 Defaults to @samp{"root@@localhost.localdomain"}.
14188 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
14189 The ServerAlias directive is used for HTTP Host header validation when
14190 clients connect to the scheduler from external interfaces. Using the
14191 special name @code{*} can expose your system to known browser-based DNS
14192 rebinding attacks, even when accessing sites through a firewall. If the
14193 auto-discovery of alternate names does not work, we recommend listing
14194 each alternate name with a ServerAlias directive instead of using
14197 Defaults to @samp{*}.
14200 @deftypevr {@code{cups-configuration} parameter} string server-name
14201 Specifies the fully-qualified host name of the server.
14203 Defaults to @samp{"localhost"}.
14206 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
14207 Specifies what information is included in the Server header of HTTP
14208 responses. @code{None} disables the Server header. @code{ProductOnly}
14209 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
14210 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
14211 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
14212 the output of the @code{uname} command. @code{Full} reports @code{CUPS
14213 2.0.0 (@var{uname}) IPP/2.0}.
14215 Defaults to @samp{Minimal}.
14218 @deftypevr {@code{cups-configuration} parameter} string set-env
14219 Set the specified environment variable to be passed to child processes.
14221 Defaults to @samp{"variable value"}.
14224 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
14225 Listens on the specified interfaces for encrypted connections. Valid
14226 values are of the form @var{address}:@var{port}, where @var{address} is
14227 either an IPv6 address enclosed in brackets, an IPv4 address, or
14228 @code{*} to indicate all addresses.
14230 Defaults to @samp{()}.
14233 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
14234 Sets encryption options. By default, CUPS only supports encryption
14235 using TLS v1.0 or higher using known secure cipher suites. The
14236 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
14237 required for some older clients that do not implement newer ones. The
14238 @code{AllowSSL3} option enables SSL v3.0, which is required for some
14239 older clients that do not support TLS v1.0.
14241 Defaults to @samp{()}.
14244 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
14245 Specifies whether the scheduler requires clients to strictly adhere to
14246 the IPP specifications.
14248 Defaults to @samp{#f}.
14251 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
14252 Specifies the HTTP request timeout, in seconds.
14254 Defaults to @samp{300}.
14258 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
14259 Specifies whether the web interface is enabled.
14261 Defaults to @samp{#f}.
14264 At this point you're probably thinking ``oh dear, Guix manual, I like
14265 you but you can stop already with the configuration options''. Indeed.
14266 However, one more point: it could be that you have an existing
14267 @code{cupsd.conf} that you want to use. In that case, you can pass an
14268 @code{opaque-cups-configuration} as the configuration of a
14269 @code{cups-service-type}.
14271 Available @code{opaque-cups-configuration} fields are:
14273 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
14277 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
14278 The contents of the @code{cupsd.conf}, as a string.
14281 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
14282 The contents of the @code{cups-files.conf} file, as a string.
14285 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
14286 strings of the same name, you could instantiate a CUPS service like
14290 (service cups-service-type
14291 (opaque-cups-configuration
14292 (cupsd.conf cupsd.conf)
14293 (cups-files.conf cups-files.conf)))
14297 @node Desktop Services
14298 @subsection Desktop Services
14300 The @code{(gnu services desktop)} module provides services that are
14301 usually useful in the context of a ``desktop'' setup---that is, on a
14302 machine running a graphical display server, possibly with graphical user
14303 interfaces, etc. It also defines services that provide specific desktop
14304 environments like GNOME, XFCE or MATE.
14306 To simplify things, the module defines a variable containing the set of
14307 services that users typically expect on a machine with a graphical
14308 environment and networking:
14310 @defvr {Scheme Variable} %desktop-services
14311 This is a list of services that builds upon @var{%base-services} and
14312 adds or adjusts services for a typical ``desktop'' setup.
14314 In particular, it adds a graphical login manager (@pxref{X Window,
14315 @code{slim-service}}), screen lockers, a network management tool
14316 (@pxref{Networking Services, @code{network-manager-service-type}}), energy and color
14317 management services, the @code{elogind} login and seat manager, the
14318 Polkit privilege service, the GeoClue location service, the
14319 AccountsService daemon that allows authorized users change system
14320 passwords, an NTP client (@pxref{Networking Services}), the Avahi
14321 daemon, and has the name service switch service configured to be able to
14322 use @code{nss-mdns} (@pxref{Name Service Switch, mDNS}).
14325 The @var{%desktop-services} variable can be used as the @code{services}
14326 field of an @code{operating-system} declaration (@pxref{operating-system
14327 Reference, @code{services}}).
14329 Additionally, the @code{gnome-desktop-service},
14330 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
14331 @code{enlightenment-desktop-service-type} procedures can add GNOME, XFCE, MATE
14332 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
14333 services like the backlight adjustment helpers and the power management
14334 utilities are added to the system, extending @code{polkit} and @code{dbus}
14335 appropriately, allowing GNOME to operate with elevated privileges on a
14336 limited number of special-purpose system interfaces. Additionally,
14337 adding a service made by @code{gnome-desktop-service} adds the GNOME
14338 metapackage to the system profile. Likewise, adding the XFCE service
14339 not only adds the @code{xfce} metapackage to the system profile, but it
14340 also gives the Thunar file manager the ability to open a ``root-mode''
14341 file management window, if the user authenticates using the
14342 administrator's password via the standard polkit graphical interface.
14343 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
14344 appropriately, allowing MATE to operate with elevated privileges on a
14345 limited number of special-purpose system interfaces. Additionally,
14346 adding a service of type @code{mate-desktop-service-type} adds the MATE
14347 metapackage to the system profile. ``Adding Enlightenment'' means that
14348 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
14349 are set as setuid, allowing Enlightenment's screen locker and other
14350 functionality to work as expetected.
14352 The desktop environments in Guix use the Xorg display server by
14353 default. If you'd like to use the newer display server protocol
14354 called Wayland, you need to use the @code{sddm-service} instead of the
14355 @code{slim-service} for the graphical login manager. You should then
14356 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
14357 also try starting GNOME on Wayland manually from a TTY with the
14358 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
14359 gnome-session``. Currently only GNOME has support for Wayland.
14361 @deffn {Scheme Procedure} gnome-desktop-service
14362 Return a service that adds the @code{gnome} package to the system
14363 profile, and extends polkit with the actions from
14364 @code{gnome-settings-daemon}.
14367 @deffn {Scheme Procedure} xfce-desktop-service
14368 Return a service that adds the @code{xfce} package to the system profile,
14369 and extends polkit with the ability for @code{thunar} to manipulate the
14370 file system as root from within a user session, after the user has
14371 authenticated with the administrator's password.
14374 @deffn {Scheme Variable} mate-desktop-service-type
14375 This is the type of the service that runs the @uref{https://mate-desktop.org/,
14376 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
14377 object (see below.)
14379 This service adds the @code{mate} package to the system
14380 profile, and extends polkit with the actions from
14381 @code{mate-settings-daemon}.
14384 @deftp {Data Type} mate-desktop-configuration
14385 Configuration record for the MATE desktop environment.
14388 @item @code{mate} (default @code{mate})
14389 The MATE package to use.
14393 @deffn {Scheme Variable} enlightenment-desktop-service-type
14394 Return a service that adds the @code{enlightenment} package to the system
14395 profile, and extends dbus with actions from @code{efl}.
14398 @deftp {Data Type} enlightenment-desktop-service-configuration
14400 @item @code{enlightenment} (default @code{enlightenment})
14401 The enlightenment package to use.
14405 Because the GNOME, XFCE and MATE desktop services pull in so many packages,
14406 the default @code{%desktop-services} variable doesn't include any of
14407 them by default. To add GNOME, XFCE or MATE, just @code{cons} them onto
14408 @code{%desktop-services} in the @code{services} field of your
14409 @code{operating-system}:
14412 (use-modules (gnu))
14413 (use-service-modules desktop)
14416 ;; cons* adds items to the list given as its last argument.
14417 (services (cons* (gnome-desktop-service)
14418 (xfce-desktop-service)
14419 %desktop-services))
14423 These desktop environments will then be available as options in the
14424 graphical login window.
14426 The actual service definitions included in @code{%desktop-services} and
14427 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
14428 are described below.
14430 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
14431 Return a service that runs the ``system bus'', using @var{dbus}, with
14432 support for @var{services}.
14434 @uref{http://dbus.freedesktop.org/, D-Bus} is an inter-process communication
14435 facility. Its system bus is used to allow system services to communicate
14436 and to be notified of system-wide events.
14438 @var{services} must be a list of packages that provide an
14439 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
14440 and policy files. For example, to allow avahi-daemon to use the system bus,
14441 @var{services} must be equal to @code{(list avahi)}.
14444 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
14445 Return a service that runs the @code{elogind} login and
14446 seat management daemon. @uref{https://github.com/elogind/elogind,
14447 Elogind} exposes a D-Bus interface that can be used to know which users
14448 are logged in, know what kind of sessions they have open, suspend the
14449 system, inhibit system suspend, reboot the system, and other tasks.
14451 Elogind handles most system-level power events for a computer, for
14452 example suspending the system when a lid is closed, or shutting it down
14453 when the power button is pressed.
14455 The @var{config} keyword argument specifies the configuration for
14456 elogind, and should be the result of an @code{(elogind-configuration
14457 (@var{parameter} @var{value})...)} invocation. Available parameters and
14458 their default values are:
14461 @item kill-user-processes?
14463 @item kill-only-users
14465 @item kill-exclude-users
14467 @item inhibit-delay-max-seconds
14469 @item handle-power-key
14471 @item handle-suspend-key
14473 @item handle-hibernate-key
14475 @item handle-lid-switch
14477 @item handle-lid-switch-docked
14479 @item power-key-ignore-inhibited?
14481 @item suspend-key-ignore-inhibited?
14483 @item hibernate-key-ignore-inhibited?
14485 @item lid-switch-ignore-inhibited?
14487 @item holdoff-timeout-seconds
14491 @item idle-action-seconds
14493 @item runtime-directory-size-percent
14495 @item runtime-directory-size
14499 @item suspend-state
14500 @code{("mem" "standby" "freeze")}
14503 @item hibernate-state
14505 @item hibernate-mode
14506 @code{("platform" "shutdown")}
14507 @item hybrid-sleep-state
14509 @item hybrid-sleep-mode
14510 @code{("suspend" "platform" "shutdown")}
14514 @deffn {Scheme Procedure} accountsservice-service @
14515 [#:accountsservice @var{accountsservice}]
14516 Return a service that runs AccountsService, a system service that can
14517 list available accounts, change their passwords, and so on.
14518 AccountsService integrates with PolicyKit to enable unprivileged users
14519 to acquire the capability to modify their system configuration.
14520 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
14521 accountsservice web site} for more information.
14523 The @var{accountsservice} keyword argument is the @code{accountsservice}
14524 package to expose as a service.
14527 @deffn {Scheme Procedure} polkit-service @
14528 [#:polkit @var{polkit}]
14529 Return a service that runs the
14530 @uref{http://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
14531 management service}, which allows system administrators to grant access to
14532 privileged operations in a structured way. By querying the Polkit service, a
14533 privileged system component can know when it should grant additional
14534 capabilities to ordinary users. For example, an ordinary user can be granted
14535 the capability to suspend the system if the user is logged in locally.
14538 @defvr {Scheme Variable} upower-service-type
14539 Service that runs @uref{http://upower.freedesktop.org/, @command{upowerd}}, a
14540 system-wide monitor for power consumption and battery levels, with the given
14541 configuration settings.
14543 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
14544 notably used by GNOME.
14547 @deftp {Data Type} upower-configuration
14548 Data type representation the configuration for UPower.
14552 @item @code{upower} (default: @var{upower})
14553 Package to use for @code{upower}.
14555 @item @code{watts-up-pro?} (default: @code{#f})
14556 Enable the Watts Up Pro device.
14558 @item @code{poll-batteries?} (default: @code{#t})
14559 Enable polling the kernel for battery level changes.
14561 @item @code{ignore-lid?} (default: @code{#f})
14562 Ignore the lid state, this can be useful if it's incorrect on a device.
14564 @item @code{use-percentage-for-policy?} (default: @code{#f})
14565 Whether battery percentage based policy should be used. The default is to use
14566 the time left, change to @code{#t} to use the percentage.
14568 @item @code{percentage-low} (default: @code{10})
14569 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14570 at which the battery is considered low.
14572 @item @code{percentage-critical} (default: @code{3})
14573 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14574 at which the battery is considered critical.
14576 @item @code{percentage-action} (default: @code{2})
14577 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14578 at which action will be taken.
14580 @item @code{time-low} (default: @code{1200})
14581 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14582 seconds at which the battery is considered low.
14584 @item @code{time-critical} (default: @code{300})
14585 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14586 seconds at which the battery is considered critical.
14588 @item @code{time-action} (default: @code{120})
14589 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14590 seconds at which action will be taken.
14592 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
14593 The action taken when @code{percentage-action} or @code{time-action} is
14594 reached (depending on the configuration of @code{use-percentage-for-policy?}).
14596 Possible values are:
14606 @code{'hybrid-sleep}.
14612 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
14613 Return a service for @uref{http://udisks.freedesktop.org/docs/latest/,
14614 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
14615 notifications and ways to mount/unmount disks. Programs that talk to UDisks
14616 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
14619 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
14620 Return a service that runs @command{colord}, a system service with a D-Bus
14621 interface to manage the color profiles of input and output devices such as
14622 screens and scanners. It is notably used by the GNOME Color Manager graphical
14623 tool. See @uref{http://www.freedesktop.org/software/colord/, the colord web
14624 site} for more information.
14627 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
14628 Return a configuration allowing an application to access GeoClue
14629 location data. @var{name} is the Desktop ID of the application, without
14630 the @code{.desktop} part. If @var{allowed?} is true, the application
14631 will have access to location information by default. The boolean
14632 @var{system?} value indicates whether an application is a system component
14633 or not. Finally @var{users} is a list of UIDs of all users for which
14634 this application is allowed location info access. An empty users list
14635 means that all users are allowed.
14638 @defvr {Scheme Variable} %standard-geoclue-applications
14639 The standard list of well-known GeoClue application configurations,
14640 granting authority to the GNOME date-and-time utility to ask for the
14641 current location in order to set the time zone, and allowing the
14642 IceCat and Epiphany web browsers to request location information.
14643 IceCat and Epiphany both query the user before allowing a web page to
14644 know the user's location.
14647 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
14648 [#:whitelist '()] @
14649 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
14650 [#:submit-data? #f]
14651 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
14652 [#:submission-nick "geoclue"] @
14653 [#:applications %standard-geoclue-applications]
14654 Return a service that runs the GeoClue location service. This service
14655 provides a D-Bus interface to allow applications to request access to a
14656 user's physical location, and optionally to add information to online
14657 location databases. See
14658 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
14659 web site} for more information.
14662 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
14663 [@w{#:auto-enable? #f}]
14664 Return a service that runs the @command{bluetoothd} daemon, which
14665 manages all the Bluetooth devices and provides a number of D-Bus
14666 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
14667 powered automatically at boot, which can be useful when using a
14668 bluetooth keyboard or mouse.
14670 Users need to be in the @code{lp} group to access the D-Bus service.
14673 @node Sound Services
14674 @subsection Sound Services
14676 @cindex sound support
14678 @cindex PulseAudio, sound support
14680 The @code{(gnu services sound)} module provides a service to configure the
14681 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
14682 preferred ALSA output driver.
14684 @deffn {Scheme Variable} alsa-service-type
14685 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
14686 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
14687 configuration file. The value for this type is a @command{alsa-configuration}
14688 record as in this example:
14691 (service alsa-service-type)
14694 See below for details about @code{alsa-configuration}.
14697 @deftp {Data Type} alsa-configuration
14698 Data type representing the configuration for @code{alsa-service}.
14701 @item @code{alsa-plugins} (default: @var{alsa-plugins})
14702 @code{alsa-plugins} package to use.
14704 @item @code{pulseaudio?} (default: @var{#t})
14705 Whether ALSA applications should transparently be made to use the
14706 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
14708 Using PulseAudio allows you to run several sound-producing applications
14709 at the same time and to individual control them @i{via}
14710 @command{pavucontrol}, among other things.
14712 @item @code{extra-options} (default: @var{""})
14713 String to append to the @file{/etc/asound.conf} file.
14718 Individual users who want to override the system configuration of ALSA can do
14719 it with the @file{~/.asoundrc} file:
14722 # In guix, we have to specify the absolute path for plugins.
14724 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
14727 # Routing ALSA to jack:
14728 # <http://jackaudio.org/faq/routing_alsa.html>.
14732 0 system:playback_1
14733 1 system:playback_2
14750 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
14754 @node Database Services
14755 @subsection Database Services
14759 The @code{(gnu services databases)} module provides the following services.
14761 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
14762 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
14763 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
14764 Return a service that runs @var{postgresql}, the PostgreSQL database
14767 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
14768 creates a database cluster with @var{locale} as the default
14769 locale, stored in @var{data-directory}. It then listens on @var{port}.
14771 @cindex postgresql extension-packages
14772 Additional extensions are loaded from packages listed in
14773 @var{extension-packages}. Extensions are available at runtime. For instance,
14774 to create a geographic database using the @code{postgis} extension, a user can
14775 configure the postgresql-service as in this example:
14779 (use-package-modules databases geo)
14783 ;; postgresql is required to run `psql' but postgis is not required for
14784 ;; proper operation.
14785 (packages (cons* postgresql %base-packages))
14788 (postgresql-service #:extension-packages (list postgis))
14792 Then the extension becomes visible and you can initialise an empty geographic
14793 database in this way:
14797 > create database postgistest;
14798 > \connect postgistest;
14799 > create extension postgis;
14800 > create extension postgis_topology;
14803 There is no need to add this field for contrib extensions such as hstore or
14804 dblink as they are already loadable by postgresql. This field is only
14805 required to add extensions provided by other packages.
14808 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
14809 Return a service that runs @command{mysqld}, the MySQL or MariaDB
14812 The optional @var{config} argument specifies the configuration for
14813 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
14816 @deftp {Data Type} mysql-configuration
14817 Data type representing the configuration of @var{mysql-service}.
14820 @item @code{mysql} (default: @var{mariadb})
14821 Package object of the MySQL database server, can be either @var{mariadb}
14824 For MySQL, a temporary root password will be displayed at activation time.
14825 For MariaDB, the root password is empty.
14827 @item @code{port} (default: @code{3306})
14828 TCP port on which the database server listens for incoming connections.
14832 @defvr {Scheme Variable} memcached-service-type
14833 This is the service type for the @uref{https://memcached.org/,
14834 Memcached} service, which provides a distributed in memory cache. The
14835 value for the service type is a @code{memcached-configuration} object.
14839 (service memcached-service-type)
14842 @deftp {Data Type} memcached-configuration
14843 Data type representing the configuration of memcached.
14846 @item @code{memcached} (default: @code{memcached})
14847 The Memcached package to use.
14849 @item @code{interfaces} (default: @code{'("0.0.0.0")})
14850 Network interfaces on which to listen.
14852 @item @code{tcp-port} (default: @code{11211})
14853 Port on which to accept connections on,
14855 @item @code{udp-port} (default: @code{11211})
14856 Port on which to accept UDP connections on, a value of 0 will disable
14857 listening on a UDP socket.
14859 @item @code{additional-options} (default: @code{'()})
14860 Additional command line options to pass to @code{memcached}.
14864 @defvr {Scheme Variable} mongodb-service-type
14865 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
14866 The value for the service type is a @code{mongodb-configuration} object.
14870 (service mongodb-service-type)
14873 @deftp {Data Type} mongodb-configuration
14874 Data type representing the configuration of mongodb.
14877 @item @code{mongodb} (default: @code{mongodb})
14878 The MongoDB package to use.
14880 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
14881 The configuration file for MongoDB.
14883 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
14884 This value is used to create the directory, so that it exists and is
14885 owned by the mongodb user. It should match the data-directory which
14886 MongoDB is configured to use through the configuration file.
14890 @defvr {Scheme Variable} redis-service-type
14891 This is the service type for the @uref{https://redis.io/, Redis}
14892 key/value store, whose value is a @code{redis-configuration} object.
14895 @deftp {Data Type} redis-configuration
14896 Data type representing the configuration of redis.
14899 @item @code{redis} (default: @code{redis})
14900 The Redis package to use.
14902 @item @code{bind} (default: @code{"127.0.0.1"})
14903 Network interface on which to listen.
14905 @item @code{port} (default: @code{6379})
14906 Port on which to accept connections on, a value of 0 will disable
14907 listening on a TCP socket.
14909 @item @code{working-directory} (default: @code{"/var/lib/redis"})
14910 Directory in which to store the database and related files.
14914 @node Mail Services
14915 @subsection Mail Services
14919 The @code{(gnu services mail)} module provides Guix service definitions
14920 for email services: IMAP, POP3, and LMTP servers, as well as mail
14921 transport agents (MTAs). Lots of acronyms! These services are detailed
14922 in the subsections below.
14924 @subsubheading Dovecot Service
14926 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
14927 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
14930 By default, Dovecot does not need much configuration; the default
14931 configuration object created by @code{(dovecot-configuration)} will
14932 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
14933 certificate will be generated for TLS-protected connections, though
14934 Dovecot will also listen on cleartext ports by default. There are a
14935 number of options, though, which mail administrators might need to change,
14936 and as is the case with other services, Guix allows the system
14937 administrator to specify these parameters via a uniform Scheme interface.
14939 For example, to specify that mail is located at @code{maildir~/.mail},
14940 one would instantiate the Dovecot service like this:
14943 (dovecot-service #:config
14944 (dovecot-configuration
14945 (mail-location "maildir:~/.mail")))
14948 The available configuration parameters follow. Each parameter
14949 definition is preceded by its type; for example, @samp{string-list foo}
14950 indicates that the @code{foo} parameter should be specified as a list of
14951 strings. There is also a way to specify the configuration as a string,
14952 if you have an old @code{dovecot.conf} file that you want to port over
14953 from some other system; see the end for more details.
14955 @c The following documentation was initially generated by
14956 @c (generate-documentation) in (gnu services mail). Manually maintained
14957 @c documentation is better, so we shouldn't hesitate to edit below as
14958 @c needed. However if the change you want to make to this documentation
14959 @c can be done in an automated way, it's probably easier to change
14960 @c (generate-documentation) than to make it below and have to deal with
14961 @c the churn as dovecot updates.
14963 Available @code{dovecot-configuration} fields are:
14965 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
14966 The dovecot package.
14969 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
14970 A list of IPs or hosts where to listen for connections. @samp{*}
14971 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
14972 interfaces. If you want to specify non-default ports or anything more
14973 complex, customize the address and port fields of the
14974 @samp{inet-listener} of the specific services you are interested in.
14977 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
14978 List of protocols we want to serve. Available protocols include
14979 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
14981 Available @code{protocol-configuration} fields are:
14983 @deftypevr {@code{protocol-configuration} parameter} string name
14984 The name of the protocol.
14987 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
14988 UNIX socket path to the master authentication server to find users.
14989 This is used by imap (for shared users) and lda.
14990 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
14993 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
14994 Space separated list of plugins to load.
14997 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
14998 Maximum number of IMAP connections allowed for a user from each IP
14999 address. NOTE: The username is compared case-sensitively.
15000 Defaults to @samp{10}.
15005 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
15006 List of services to enable. Available services include @samp{imap},
15007 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
15010 Available @code{service-configuration} fields are:
15012 @deftypevr {@code{service-configuration} parameter} string kind
15013 The service kind. Valid values include @code{director},
15014 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
15015 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
15016 @code{tcpwrap}, @code{quota-warning}, or anything else.
15019 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
15020 Listeners for the service. A listener is either a
15021 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
15022 an @code{inet-listener-configuration}.
15023 Defaults to @samp{()}.
15025 Available @code{unix-listener-configuration} fields are:
15027 @deftypevr {@code{unix-listener-configuration} parameter} string path
15028 Path to the file, relative to @code{base-dir} field. This is also used as
15032 @deftypevr {@code{unix-listener-configuration} parameter} string mode
15033 The access mode for the socket.
15034 Defaults to @samp{"0600"}.
15037 @deftypevr {@code{unix-listener-configuration} parameter} string user
15038 The user to own the socket.
15039 Defaults to @samp{""}.
15042 @deftypevr {@code{unix-listener-configuration} parameter} string group
15043 The group to own the socket.
15044 Defaults to @samp{""}.
15048 Available @code{fifo-listener-configuration} fields are:
15050 @deftypevr {@code{fifo-listener-configuration} parameter} string path
15051 Path to the file, relative to @code{base-dir} field. This is also used as
15055 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
15056 The access mode for the socket.
15057 Defaults to @samp{"0600"}.
15060 @deftypevr {@code{fifo-listener-configuration} parameter} string user
15061 The user to own the socket.
15062 Defaults to @samp{""}.
15065 @deftypevr {@code{fifo-listener-configuration} parameter} string group
15066 The group to own the socket.
15067 Defaults to @samp{""}.
15071 Available @code{inet-listener-configuration} fields are:
15073 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
15074 The protocol to listen for.
15077 @deftypevr {@code{inet-listener-configuration} parameter} string address
15078 The address on which to listen, or empty for all addresses.
15079 Defaults to @samp{""}.
15082 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
15083 The port on which to listen.
15086 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
15087 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
15089 Defaults to @samp{#t}.
15094 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
15095 Maximum number of simultaneous client connections per process. Once
15096 this number of connections is received, the next incoming connection
15097 will prompt Dovecot to spawn another process. If set to 0,
15098 @code{default-client-limit} is used instead.
15100 Defaults to @samp{0}.
15104 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
15105 Number of connections to handle before starting a new process.
15106 Typically the only useful values are 0 (unlimited) or 1. 1 is more
15107 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
15108 Defaults to @samp{1}.
15112 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
15113 Maximum number of processes that can exist for this service. If set to
15114 0, @code{default-process-limit} is used instead.
15116 Defaults to @samp{0}.
15120 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
15121 Number of processes to always keep waiting for more connections.
15122 Defaults to @samp{0}.
15125 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
15126 If you set @samp{service-count 0}, you probably need to grow
15128 Defaults to @samp{256000000}.
15133 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
15134 Dict configuration, as created by the @code{dict-configuration}
15137 Available @code{dict-configuration} fields are:
15139 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
15140 A list of key-value pairs that this dict should hold.
15141 Defaults to @samp{()}.
15146 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
15147 A list of passdb configurations, each one created by the
15148 @code{passdb-configuration} constructor.
15150 Available @code{passdb-configuration} fields are:
15152 @deftypevr {@code{passdb-configuration} parameter} string driver
15153 The driver that the passdb should use. Valid values include
15154 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
15156 Defaults to @samp{"pam"}.
15159 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
15160 Space separated list of arguments to the passdb driver.
15161 Defaults to @samp{""}.
15166 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
15167 List of userdb configurations, each one created by the
15168 @code{userdb-configuration} constructor.
15170 Available @code{userdb-configuration} fields are:
15172 @deftypevr {@code{userdb-configuration} parameter} string driver
15173 The driver that the userdb should use. Valid values include
15174 @samp{passwd} and @samp{static}.
15175 Defaults to @samp{"passwd"}.
15178 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
15179 Space separated list of arguments to the userdb driver.
15180 Defaults to @samp{""}.
15183 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
15184 Override fields from passwd.
15185 Defaults to @samp{()}.
15190 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
15191 Plug-in configuration, created by the @code{plugin-configuration}
15195 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
15196 List of namespaces. Each item in the list is created by the
15197 @code{namespace-configuration} constructor.
15199 Available @code{namespace-configuration} fields are:
15201 @deftypevr {@code{namespace-configuration} parameter} string name
15202 Name for this namespace.
15205 @deftypevr {@code{namespace-configuration} parameter} string type
15206 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
15207 Defaults to @samp{"private"}.
15210 @deftypevr {@code{namespace-configuration} parameter} string separator
15211 Hierarchy separator to use. You should use the same separator for
15212 all namespaces or some clients get confused. @samp{/} is usually a good
15213 one. The default however depends on the underlying mail storage
15215 Defaults to @samp{""}.
15218 @deftypevr {@code{namespace-configuration} parameter} string prefix
15219 Prefix required to access this namespace. This needs to be
15220 different for all namespaces. For example @samp{Public/}.
15221 Defaults to @samp{""}.
15224 @deftypevr {@code{namespace-configuration} parameter} string location
15225 Physical location of the mailbox. This is in the same format as
15226 mail_location, which is also the default for it.
15227 Defaults to @samp{""}.
15230 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
15231 There can be only one INBOX, and this setting defines which
15233 Defaults to @samp{#f}.
15236 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
15237 If namespace is hidden, it's not advertised to clients via NAMESPACE
15238 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
15239 useful when converting from another server with different namespaces
15240 which you want to deprecate but still keep working. For example you can
15241 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
15243 Defaults to @samp{#f}.
15246 @deftypevr {@code{namespace-configuration} parameter} boolean list?
15247 Show the mailboxes under this namespace with the LIST command. This
15248 makes the namespace visible for clients that do not support the NAMESPACE
15249 extension. The special @code{children} value lists child mailboxes, but
15250 hides the namespace prefix.
15251 Defaults to @samp{#t}.
15254 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
15255 Namespace handles its own subscriptions. If set to @code{#f}, the
15256 parent namespace handles them. The empty prefix should always have this
15258 Defaults to @samp{#t}.
15261 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
15262 List of predefined mailboxes in this namespace.
15263 Defaults to @samp{()}.
15265 Available @code{mailbox-configuration} fields are:
15267 @deftypevr {@code{mailbox-configuration} parameter} string name
15268 Name for this mailbox.
15271 @deftypevr {@code{mailbox-configuration} parameter} string auto
15272 @samp{create} will automatically create this mailbox.
15273 @samp{subscribe} will both create and subscribe to the mailbox.
15274 Defaults to @samp{"no"}.
15277 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
15278 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
15279 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
15280 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
15281 Defaults to @samp{()}.
15288 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
15289 Base directory where to store runtime data.
15290 Defaults to @samp{"/var/run/dovecot/"}.
15293 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
15294 Greeting message for clients.
15295 Defaults to @samp{"Dovecot ready."}.
15298 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
15299 List of trusted network ranges. Connections from these IPs are
15300 allowed to override their IP addresses and ports (for logging and for
15301 authentication checks). @samp{disable-plaintext-auth} is also ignored
15302 for these networks. Typically you would specify your IMAP proxy servers
15304 Defaults to @samp{()}.
15307 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
15308 List of login access check sockets (e.g.@: tcpwrap).
15309 Defaults to @samp{()}.
15312 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
15313 Show more verbose process titles (in ps). Currently shows user name
15314 and IP address. Useful for seeing who is actually using the IMAP
15315 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
15317 Defaults to @samp{#f}.
15320 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
15321 Should all processes be killed when Dovecot master process shuts down.
15322 Setting this to @code{#f} means that Dovecot can be upgraded without
15323 forcing existing client connections to close (although that could also
15324 be a problem if the upgrade is e.g.@: due to a security fix).
15325 Defaults to @samp{#t}.
15328 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
15329 If non-zero, run mail commands via this many connections to doveadm
15330 server, instead of running them directly in the same process.
15331 Defaults to @samp{0}.
15334 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
15335 UNIX socket or host:port used for connecting to doveadm server.
15336 Defaults to @samp{"doveadm-server"}.
15339 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
15340 List of environment variables that are preserved on Dovecot startup
15341 and passed down to all of its child processes. You can also give
15342 key=value pairs to always set specific settings.
15345 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
15346 Disable LOGIN command and all other plaintext authentications unless
15347 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
15348 matches the local IP (i.e.@: you're connecting from the same computer),
15349 the connection is considered secure and plaintext authentication is
15350 allowed. See also ssl=required setting.
15351 Defaults to @samp{#t}.
15354 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
15355 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
15356 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
15357 for caching to be used.
15358 Defaults to @samp{0}.
15361 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
15362 Time to live for cached data. After TTL expires the cached record
15363 is no longer used, *except* if the main database lookup returns internal
15364 failure. We also try to handle password changes automatically: If
15365 user's previous authentication was successful, but this one wasn't, the
15366 cache isn't used. For now this works only with plaintext
15368 Defaults to @samp{"1 hour"}.
15371 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
15372 TTL for negative hits (user not found, password mismatch).
15373 0 disables caching them completely.
15374 Defaults to @samp{"1 hour"}.
15377 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
15378 List of realms for SASL authentication mechanisms that need them.
15379 You can leave it empty if you don't want to support multiple realms.
15380 Many clients simply use the first one listed here, so keep the default
15382 Defaults to @samp{()}.
15385 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
15386 Default realm/domain to use if none was specified. This is used for
15387 both SASL realms and appending @@domain to username in plaintext
15389 Defaults to @samp{""}.
15392 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
15393 List of allowed characters in username. If the user-given username
15394 contains a character not listed in here, the login automatically fails.
15395 This is just an extra check to make sure user can't exploit any
15396 potential quote escaping vulnerabilities with SQL/LDAP databases. If
15397 you want to allow all characters, set this value to empty.
15398 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
15401 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
15402 Username character translations before it's looked up from
15403 databases. The value contains series of from -> to characters. For
15404 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
15405 translated to @samp{@@}.
15406 Defaults to @samp{""}.
15409 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
15410 Username formatting before it's looked up from databases. You can
15411 use the standard variables here, e.g.@: %Lu would lowercase the username,
15412 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
15413 change the @samp{@@} into @samp{-AT-}. This translation is done after
15414 @samp{auth-username-translation} changes.
15415 Defaults to @samp{"%Lu"}.
15418 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
15419 If you want to allow master users to log in by specifying the master
15420 username within the normal username string (i.e.@: not using SASL
15421 mechanism's support for it), you can specify the separator character
15422 here. The format is then <username><separator><master username>.
15423 UW-IMAP uses @samp{*} as the separator, so that could be a good
15425 Defaults to @samp{""}.
15428 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
15429 Username to use for users logging in with ANONYMOUS SASL
15431 Defaults to @samp{"anonymous"}.
15434 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
15435 Maximum number of dovecot-auth worker processes. They're used to
15436 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
15437 They're automatically created and destroyed as needed.
15438 Defaults to @samp{30}.
15441 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
15442 Host name to use in GSSAPI principal names. The default is to use
15443 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
15444 allow all keytab entries.
15445 Defaults to @samp{""}.
15448 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
15449 Kerberos keytab to use for the GSSAPI mechanism. Will use the
15450 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
15451 need to change the auth service to run as root to be able to read this
15453 Defaults to @samp{""}.
15456 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
15457 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
15458 and @samp{ntlm-auth} helper.
15459 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
15460 Defaults to @samp{#f}.
15463 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
15464 Path for Samba's @samp{ntlm-auth} helper binary.
15465 Defaults to @samp{"/usr/bin/ntlm_auth"}.
15468 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
15469 Time to delay before replying to failed authentications.
15470 Defaults to @samp{"2 secs"}.
15473 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
15474 Require a valid SSL client certificate or the authentication
15476 Defaults to @samp{#f}.
15479 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
15480 Take the username from client's SSL certificate, using
15481 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
15483 Defaults to @samp{#f}.
15486 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
15487 List of wanted authentication mechanisms. Supported mechanisms are:
15488 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
15489 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
15490 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
15491 @samp{disable-plaintext-auth} setting.
15494 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
15495 List of IPs or hostnames to all director servers, including ourself.
15496 Ports can be specified as ip:port. The default port is the same as what
15497 director service's @samp{inet-listener} is using.
15498 Defaults to @samp{()}.
15501 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
15502 List of IPs or hostnames to all backend mail servers. Ranges are
15503 allowed too, like 10.0.0.10-10.0.0.30.
15504 Defaults to @samp{()}.
15507 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
15508 How long to redirect users to a specific server after it no longer
15509 has any connections.
15510 Defaults to @samp{"15 min"}.
15513 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
15514 How the username is translated before being hashed. Useful values
15515 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
15516 are shared within domain.
15517 Defaults to @samp{"%Lu"}.
15520 @deftypevr {@code{dovecot-configuration} parameter} string log-path
15521 Log file to use for error messages. @samp{syslog} logs to syslog,
15522 @samp{/dev/stderr} logs to stderr.
15523 Defaults to @samp{"syslog"}.
15526 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
15527 Log file to use for informational messages. Defaults to
15529 Defaults to @samp{""}.
15532 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
15533 Log file to use for debug messages. Defaults to
15534 @samp{info-log-path}.
15535 Defaults to @samp{""}.
15538 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
15539 Syslog facility to use if you're logging to syslog. Usually if you
15540 don't want to use @samp{mail}, you'll use local0..local7. Also other
15541 standard facilities are supported.
15542 Defaults to @samp{"mail"}.
15545 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
15546 Log unsuccessful authentication attempts and the reasons why they
15548 Defaults to @samp{#f}.
15551 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose-passwords?
15552 In case of password mismatches, log the attempted password. Valid
15553 values are no, plain and sha1. sha1 can be useful for detecting brute
15554 force password attempts vs. user simply trying the same password over
15555 and over again. You can also truncate the value to n chars by appending
15556 ":n" (e.g.@: sha1:6).
15557 Defaults to @samp{#f}.
15560 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
15561 Even more verbose logging for debugging purposes. Shows for example
15563 Defaults to @samp{#f}.
15566 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
15567 In case of password mismatches, log the passwords and used scheme so
15568 the problem can be debugged. Enabling this also enables
15570 Defaults to @samp{#f}.
15573 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
15574 Enable mail process debugging. This can help you figure out why
15575 Dovecot isn't finding your mails.
15576 Defaults to @samp{#f}.
15579 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
15580 Show protocol level SSL errors.
15581 Defaults to @samp{#f}.
15584 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
15585 Prefix for each line written to log file. % codes are in
15586 strftime(3) format.
15587 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
15590 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
15591 List of elements we want to log. The elements which have a
15592 non-empty variable value are joined together to form a comma-separated
15596 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
15597 Login log format. %s contains @samp{login-log-format-elements}
15598 string, %$ contains the data we want to log.
15599 Defaults to @samp{"%$: %s"}.
15602 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
15603 Log prefix for mail processes. See doc/wiki/Variables.txt for list
15604 of possible variables you can use.
15605 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
15608 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
15609 Format to use for logging mail deliveries. You can use variables:
15612 Delivery status message (e.g.@: @samp{saved to INBOX})
15624 Defaults to @samp{"msgid=%m: %$"}.
15627 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
15628 Location for users' mailboxes. The default is empty, which means
15629 that Dovecot tries to find the mailboxes automatically. This won't work
15630 if the user doesn't yet have any mail, so you should explicitly tell
15631 Dovecot the full location.
15633 If you're using mbox, giving a path to the INBOX
15634 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
15635 where the other mailboxes are kept. This is called the "root mail
15636 directory", and it must be the first path given in the
15637 @samp{mail-location} setting.
15639 There are a few special variables you can use, eg.:
15645 user part in user@@domain, same as %u if there's no domain
15647 domain part in user@@domain, empty if there's no domain
15652 See doc/wiki/Variables.txt for full list. Some examples:
15654 @item maildir:~/Maildir
15655 @item mbox:~/mail:INBOX=/var/mail/%u
15656 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
15658 Defaults to @samp{""}.
15661 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
15662 System user and group used to access mails. If you use multiple,
15663 userdb can override these by returning uid or gid fields. You can use
15664 either numbers or names. <doc/wiki/UserIds.txt>.
15665 Defaults to @samp{""}.
15668 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
15670 Defaults to @samp{""}.
15673 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
15674 Group to enable temporarily for privileged operations. Currently
15675 this is used only with INBOX when either its initial creation or
15676 dotlocking fails. Typically this is set to "mail" to give access to
15678 Defaults to @samp{""}.
15681 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
15682 Grant access to these supplementary groups for mail processes.
15683 Typically these are used to set up access to shared mailboxes. Note
15684 that it may be dangerous to set these if users can create
15685 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
15686 could allow a user to delete others' mailboxes, or ln -s
15687 /secret/shared/box ~/mail/mybox would allow reading it).
15688 Defaults to @samp{""}.
15691 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
15692 Allow full file system access to clients. There's no access checks
15693 other than what the operating system does for the active UID/GID. It
15694 works with both maildir and mboxes, allowing you to prefix mailboxes
15695 names with e.g.@: /path/ or ~user/.
15696 Defaults to @samp{#f}.
15699 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
15700 Don't use mmap() at all. This is required if you store indexes to
15701 shared file systems (NFS or clustered file system).
15702 Defaults to @samp{#f}.
15705 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
15706 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
15707 supports @samp{O_EXCL} since version 3, so this should be safe to use
15708 nowadays by default.
15709 Defaults to @samp{#t}.
15712 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
15713 When to use fsync() or fdatasync() calls:
15716 Whenever necessary to avoid losing important data
15718 Useful with e.g.@: NFS when write()s are delayed
15720 Never use it (best performance, but crashes can lose data).
15722 Defaults to @samp{"optimized"}.
15725 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
15726 Mail storage exists in NFS. Set this to yes to make Dovecot flush
15727 NFS caches whenever needed. If you're using only a single mail server
15729 Defaults to @samp{#f}.
15732 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
15733 Mail index files also exist in NFS. Setting this to yes requires
15734 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
15735 Defaults to @samp{#f}.
15738 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
15739 Locking method for index files. Alternatives are fcntl, flock and
15740 dotlock. Dotlocking uses some tricks which may create more disk I/O
15741 than other locking methods. NFS users: flock doesn't work, remember to
15742 change @samp{mmap-disable}.
15743 Defaults to @samp{"fcntl"}.
15746 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
15747 Directory in which LDA/LMTP temporarily stores incoming mails >128
15749 Defaults to @samp{"/tmp"}.
15752 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
15753 Valid UID range for users. This is mostly to make sure that users can't
15754 log in as daemons or other system users. Note that denying root logins is
15755 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
15757 Defaults to @samp{500}.
15760 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
15762 Defaults to @samp{0}.
15765 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
15766 Valid GID range for users. Users having non-valid GID as primary group ID
15767 aren't allowed to log in. If user belongs to supplementary groups with
15768 non-valid GIDs, those groups are not set.
15769 Defaults to @samp{1}.
15772 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
15774 Defaults to @samp{0}.
15777 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
15778 Maximum allowed length for mail keyword name. It's only forced when
15779 trying to create new keywords.
15780 Defaults to @samp{50}.
15783 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
15784 List of directories under which chrooting is allowed for mail
15785 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
15786 too). This setting doesn't affect @samp{login-chroot}
15787 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
15788 "/./" in home dirs are ignored. WARNING: Never add directories here
15789 which local users can modify, that may lead to root exploit. Usually
15790 this should be done only if you don't allow shell access for users.
15791 <doc/wiki/Chrooting.txt>.
15792 Defaults to @samp{()}.
15795 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
15796 Default chroot directory for mail processes. This can be overridden
15797 for specific users in user database by giving /./ in user's home
15798 directory (e.g.@: /home/./user chroots into /home). Note that usually
15799 there is no real need to do chrooting, Dovecot doesn't allow users to
15800 access files outside their mail directory anyway. If your home
15801 directories are prefixed with the chroot directory, append "/."@: to
15802 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
15803 Defaults to @samp{""}.
15806 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
15807 UNIX socket path to master authentication server to find users.
15808 This is used by imap (for shared users) and lda.
15809 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
15812 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
15813 Directory where to look up mail plugins.
15814 Defaults to @samp{"/usr/lib/dovecot"}.
15817 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
15818 List of plugins to load for all services. Plugins specific to IMAP,
15819 LDA, etc.@: are added to this list in their own .conf files.
15820 Defaults to @samp{()}.
15823 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
15824 The minimum number of mails in a mailbox before updates are done to
15825 cache file. This allows optimizing Dovecot's behavior to do less disk
15826 writes at the cost of more disk reads.
15827 Defaults to @samp{0}.
15830 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
15831 When IDLE command is running, mailbox is checked once in a while to
15832 see if there are any new mails or other changes. This setting defines
15833 the minimum time to wait between those checks. Dovecot can also use
15834 dnotify, inotify and kqueue to find out immediately when changes
15836 Defaults to @samp{"30 secs"}.
15839 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
15840 Save mails with CR+LF instead of plain LF. This makes sending those
15841 mails take less CPU, especially with sendfile() syscall with Linux and
15842 FreeBSD. But it also creates a bit more disk I/O which may just make it
15843 slower. Also note that if other software reads the mboxes/maildirs,
15844 they may handle the extra CRs wrong and cause problems.
15845 Defaults to @samp{#f}.
15848 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
15849 By default LIST command returns all entries in maildir beginning
15850 with a dot. Enabling this option makes Dovecot return only entries
15851 which are directories. This is done by stat()ing each entry, so it
15852 causes more disk I/O.
15853 (For systems setting struct @samp{dirent->d_type} this check is free
15854 and it's done always regardless of this setting).
15855 Defaults to @samp{#f}.
15858 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
15859 When copying a message, do it with hard links whenever possible.
15860 This makes the performance much better, and it's unlikely to have any
15862 Defaults to @samp{#t}.
15865 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
15866 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
15867 directory only when its mtime changes unexpectedly or when we can't find
15868 the mail otherwise.
15869 Defaults to @samp{#f}.
15872 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
15873 Which locking methods to use for locking mbox. There are four
15878 Create <mailbox>.lock file. This is the oldest and most NFS-safe
15879 solution. If you want to use /var/mail/ like directory, the users will
15880 need write access to that directory.
15882 Same as dotlock, but if it fails because of permissions or because there
15883 isn't enough disk space, just skip it.
15885 Use this if possible. Works with NFS too if lockd is used.
15887 May not exist in all systems. Doesn't work with NFS.
15889 May not exist in all systems. Doesn't work with NFS.
15892 You can use multiple locking methods; if you do the order they're declared
15893 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
15894 locking methods as well. Some operating systems don't allow using some of
15895 them simultaneously.
15898 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
15902 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
15903 Maximum time to wait for lock (all of them) before aborting.
15904 Defaults to @samp{"5 mins"}.
15907 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
15908 If dotlock exists but the mailbox isn't modified in any way,
15909 override the lock file after this much time.
15910 Defaults to @samp{"2 mins"}.
15913 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
15914 When mbox changes unexpectedly we have to fully read it to find out
15915 what changed. If the mbox is large this can take a long time. Since
15916 the change is usually just a newly appended mail, it'd be faster to
15917 simply read the new mails. If this setting is enabled, Dovecot does
15918 this but still safely fallbacks to re-reading the whole mbox file
15919 whenever something in mbox isn't how it's expected to be. The only real
15920 downside to this setting is that if some other MUA changes message
15921 flags, Dovecot doesn't notice it immediately. Note that a full sync is
15922 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
15923 Defaults to @samp{#t}.
15926 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
15927 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
15928 EXAMINE, EXPUNGE or CHECK commands. If this is set,
15929 @samp{mbox-dirty-syncs} is ignored.
15930 Defaults to @samp{#f}.
15933 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
15934 Delay writing mbox headers until doing a full write sync (EXPUNGE
15935 and CHECK commands and when closing the mailbox). This is especially
15936 useful for POP3 where clients often delete all mails. The downside is
15937 that our changes aren't immediately visible to other MUAs.
15938 Defaults to @samp{#t}.
15941 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
15942 If mbox size is smaller than this (e.g.@: 100k), don't write index
15943 files. If an index file already exists it's still read, just not
15945 Defaults to @samp{0}.
15948 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
15949 Maximum dbox file size until it's rotated.
15950 Defaults to @samp{10000000}.
15953 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
15954 Maximum dbox file age until it's rotated. Typically in days. Day
15955 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
15957 Defaults to @samp{"1d"}.
15960 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
15961 When creating new mdbox files, immediately preallocate their size to
15962 @samp{mdbox-rotate-size}. This setting currently works only in Linux
15963 with some file systems (ext4, xfs).
15964 Defaults to @samp{#f}.
15967 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
15968 sdbox and mdbox support saving mail attachments to external files,
15969 which also allows single instance storage for them. Other backends
15970 don't support this for now.
15972 WARNING: This feature hasn't been tested much yet. Use at your own risk.
15974 Directory root where to store mail attachments. Disabled, if empty.
15975 Defaults to @samp{""}.
15978 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
15979 Attachments smaller than this aren't saved externally. It's also
15980 possible to write a plugin to disable saving specific attachments
15982 Defaults to @samp{128000}.
15985 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
15986 File system backend to use for saving attachments:
15989 No SiS done by Dovecot (but this might help FS's own deduplication)
15991 SiS with immediate byte-by-byte comparison during saving
15992 @item sis-queue posix
15993 SiS with delayed comparison and deduplication.
15995 Defaults to @samp{"sis posix"}.
15998 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
15999 Hash format to use in attachment filenames. You can add any text and
16000 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
16001 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
16002 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
16003 Defaults to @samp{"%@{sha1@}"}.
16006 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
16008 Defaults to @samp{100}.
16011 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
16013 Defaults to @samp{1000}.
16016 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
16017 Default VSZ (virtual memory size) limit for service processes.
16018 This is mainly intended to catch and kill processes that leak memory
16019 before they eat up everything.
16020 Defaults to @samp{256000000}.
16023 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
16024 Login user is internally used by login processes. This is the most
16025 untrusted user in Dovecot system. It shouldn't have access to anything
16027 Defaults to @samp{"dovenull"}.
16030 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
16031 Internal user is used by unprivileged processes. It should be
16032 separate from login user, so that login processes can't disturb other
16034 Defaults to @samp{"dovecot"}.
16037 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
16038 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
16039 Defaults to @samp{"required"}.
16042 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
16043 PEM encoded X.509 SSL/TLS certificate (public key).
16044 Defaults to @samp{"</etc/dovecot/default.pem"}.
16047 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
16048 PEM encoded SSL/TLS private key. The key is opened before
16049 dropping root privileges, so keep the key file unreadable by anyone but
16051 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
16054 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
16055 If key file is password protected, give the password here.
16056 Alternatively give it when starting dovecot with -p parameter. Since
16057 this file is often world-readable, you may want to place this setting
16058 instead to a different.
16059 Defaults to @samp{""}.
16062 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
16063 PEM encoded trusted certificate authority. Set this only if you
16064 intend to use @samp{ssl-verify-client-cert? #t}. The file should
16065 contain the CA certificate(s) followed by the matching
16066 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
16067 Defaults to @samp{""}.
16070 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
16071 Require that CRL check succeeds for client certificates.
16072 Defaults to @samp{#t}.
16075 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
16076 Request client to send a certificate. If you also want to require
16077 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
16078 Defaults to @samp{#f}.
16081 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
16082 Which field from certificate to use for username. commonName and
16083 x500UniqueIdentifier are the usual choices. You'll also need to set
16084 @samp{auth-ssl-username-from-cert? #t}.
16085 Defaults to @samp{"commonName"}.
16088 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
16089 Minimum SSL protocol version to accept.
16090 Defaults to @samp{"TLSv1"}.
16093 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
16094 SSL ciphers to use.
16095 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
16098 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
16099 SSL crypto device to use, for valid values run "openssl engine".
16100 Defaults to @samp{""}.
16103 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
16104 Address to use when sending rejection mails.
16105 %d expands to recipient domain.
16106 Defaults to @samp{"postmaster@@%d"}.
16109 @deftypevr {@code{dovecot-configuration} parameter} string hostname
16110 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
16111 and in LMTP replies. Default is the system's real hostname@@domain.
16112 Defaults to @samp{""}.
16115 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
16116 If user is over quota, return with temporary failure instead of
16118 Defaults to @samp{#f}.
16121 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
16122 Binary to use for sending mails.
16123 Defaults to @samp{"/usr/sbin/sendmail"}.
16126 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
16127 If non-empty, send mails via this SMTP host[:port] instead of
16129 Defaults to @samp{""}.
16132 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
16133 Subject: header to use for rejection mails. You can use the same
16134 variables as for @samp{rejection-reason} below.
16135 Defaults to @samp{"Rejected: %s"}.
16138 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
16139 Human readable error message for rejection mails. You can use
16152 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
16155 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
16156 Delimiter character between local-part and detail in email
16158 Defaults to @samp{"+"}.
16161 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
16162 Header where the original recipient address (SMTP's RCPT TO:
16163 address) is taken from if not available elsewhere. With dovecot-lda -a
16164 parameter overrides this. A commonly used header for this is
16166 Defaults to @samp{""}.
16169 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
16170 Should saving a mail to a nonexistent mailbox automatically create
16172 Defaults to @samp{#f}.
16175 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
16176 Should automatically created mailboxes be also automatically
16178 Defaults to @samp{#f}.
16181 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
16182 Maximum IMAP command line length. Some clients generate very long
16183 command lines with huge mailboxes, so you may need to raise this if you
16184 get "Too long argument" or "IMAP command line too large" errors
16186 Defaults to @samp{64000}.
16189 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
16190 IMAP logout format string:
16193 total number of bytes read from client
16195 total number of bytes sent to client.
16197 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
16198 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@}"}.
16201 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
16202 Override the IMAP CAPABILITY response. If the value begins with '+',
16203 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
16204 Defaults to @samp{""}.
16207 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
16208 How long to wait between "OK Still here" notifications when client
16210 Defaults to @samp{"2 mins"}.
16213 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
16214 ID field names and values to send to clients. Using * as the value
16215 makes Dovecot use the default value. The following fields have default
16216 values currently: name, version, os, os-version, support-url,
16218 Defaults to @samp{""}.
16221 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
16222 ID fields sent by client to log. * means everything.
16223 Defaults to @samp{""}.
16226 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
16227 Workarounds for various client bugs:
16230 @item delay-newmail
16231 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
16232 CHECK commands. Some clients ignore them otherwise, for example OSX
16233 Mail (<v2.1). Outlook Express breaks more badly though, without this it
16234 may show user "Message no longer in server" errors. Note that OE6
16235 still breaks even with this workaround if synchronization is set to
16238 @item tb-extra-mailbox-sep
16239 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
16240 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
16241 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
16243 @item tb-lsub-flags
16244 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
16245 This makes Thunderbird realize they aren't selectable and show them
16246 greyed out, instead of only later giving "not selectable" popup error.
16248 Defaults to @samp{()}.
16251 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
16252 Host allowed in URLAUTH URLs sent by client. "*" allows all.
16253 Defaults to @samp{""}.
16257 Whew! Lots of configuration options. The nice thing about it though is
16258 that Guix has a complete interface to Dovecot's configuration
16259 language. This allows not only a nice way to declare configurations,
16260 but also offers reflective capabilities as well: users can write code to
16261 inspect and transform configurations from within Scheme.
16263 However, it could be that you just want to get a @code{dovecot.conf} up
16264 and running. In that case, you can pass an
16265 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
16266 @code{dovecot-service}. As its name indicates, an opaque configuration
16267 does not have easy reflective capabilities.
16269 Available @code{opaque-dovecot-configuration} fields are:
16271 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
16272 The dovecot package.
16275 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
16276 The contents of the @code{dovecot.conf}, as a string.
16279 For example, if your @code{dovecot.conf} is just the empty string, you
16280 could instantiate a dovecot service like this:
16283 (dovecot-service #:config
16284 (opaque-dovecot-configuration
16288 @subsubheading OpenSMTPD Service
16290 @deffn {Scheme Variable} opensmtpd-service-type
16291 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
16292 service, whose value should be an @code{opensmtpd-configuration} object
16293 as in this example:
16296 (service opensmtpd-service-type
16297 (opensmtpd-configuration
16298 (config-file (local-file "./my-smtpd.conf"))))
16302 @deftp {Data Type} opensmtpd-configuration
16303 Data type representing the configuration of opensmtpd.
16306 @item @code{package} (default: @var{opensmtpd})
16307 Package object of the OpenSMTPD SMTP server.
16309 @item @code{config-file} (default: @var{%default-opensmtpd-file})
16310 File-like object of the OpenSMTPD configuration file to use. By default
16311 it listens on the loopback network interface, and allows for mail from
16312 users and daemons on the local machine, as well as permitting email to
16313 remote servers. Run @command{man smtpd.conf} for more information.
16318 @subsubheading Exim Service
16320 @cindex mail transfer agent (MTA)
16321 @cindex MTA (mail transfer agent)
16324 @deffn {Scheme Variable} exim-service-type
16325 This is the type of the @uref{https://exim.org, Exim} mail transfer
16326 agent (MTA), whose value should be an @code{exim-configuration} object
16327 as in this example:
16330 (service exim-service-type
16331 (exim-configuration
16332 (config-file (local-file "./my-exim.conf"))))
16336 In order to use an @code{exim-service-type} service you must also have a
16337 @code{mail-aliases-service-type} service present in your
16338 @code{operating-system} (even if it has no aliases).
16340 @deftp {Data Type} exim-configuration
16341 Data type representing the configuration of exim.
16344 @item @code{package} (default: @var{exim})
16345 Package object of the Exim server.
16347 @item @code{config-file} (default: @code{#f})
16348 File-like object of the Exim configuration file to use. If its value is
16349 @code{#f} then use the default configuration file from the package
16350 provided in @code{package}. The resulting configuration file is loaded
16351 after setting the @code{exim_user} and @code{exim_group} configuration
16357 @subsubheading Mail Aliases Service
16359 @cindex email aliases
16360 @cindex aliases, for email addresses
16362 @deffn {Scheme Variable} mail-aliases-service-type
16363 This is the type of the service which provides @code{/etc/aliases},
16364 specifying how to deliver mail to users on this system.
16367 (service mail-aliases-service-type
16368 '(("postmaster" "bob")
16369 ("bob" "bob@@example.com" "bob@@example2.com")))
16373 The configuration for a @code{mail-aliases-service-type} service is an
16374 association list denoting how to deliver mail that comes to this
16375 system. Each entry is of the form @code{(alias addresses ...)}, with
16376 @code{alias} specifying the local alias and @code{addresses} specifying
16377 where to deliver this user's mail.
16379 The aliases aren't required to exist as users on the local system. In
16380 the above example, there doesn't need to be a @code{postmaster} entry in
16381 the @code{operating-system}'s @code{user-accounts} in order to deliver
16382 the @code{postmaster} mail to @code{bob} (which subsequently would
16383 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
16385 @node Messaging Services
16386 @subsection Messaging Services
16391 The @code{(gnu services messaging)} module provides Guix service
16392 definitions for messaging services: currently only Prosody is supported.
16394 @subsubheading Prosody Service
16396 @deffn {Scheme Variable} prosody-service-type
16397 This is the type for the @uref{https://prosody.im, Prosody XMPP
16398 communication server}. Its value must be a @code{prosody-configuration}
16399 record as in this example:
16402 (service prosody-service-type
16403 (prosody-configuration
16404 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
16407 (int-component-configuration
16408 (hostname "conference.example.net")
16410 (mod-muc (mod-muc-configuration)))))
16413 (virtualhost-configuration
16414 (domain "example.net"))))))
16417 See below for details about @code{prosody-configuration}.
16421 By default, Prosody does not need much configuration. Only one
16422 @code{virtualhosts} field is needed: it specifies the domain you wish
16425 You can perform various sanity checks on the generated configuration
16426 with the @code{prosodyctl check} command.
16428 Prosodyctl will also help you to import certificates from the
16429 @code{letsencrypt} directory so that the @code{prosody} user can access
16430 them. See @url{https://prosody.im/doc/letsencrypt}.
16433 prosodyctl --root cert import /etc/letsencrypt/live
16436 The available configuration parameters follow. Each parameter
16437 definition is preceded by its type; for example, @samp{string-list foo}
16438 indicates that the @code{foo} parameter should be specified as a list of
16439 strings. Types starting with @code{maybe-} denote parameters that won't
16440 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
16442 There is also a way to specify the configuration as a string, if you
16443 have an old @code{prosody.cfg.lua} file that you want to port over from
16444 some other system; see the end for more details.
16446 The @code{file-object} type designates either a file-like object
16447 (@pxref{G-Expressions, file-like objects}) or a file name.
16449 @c The following documentation was initially generated by
16450 @c (generate-documentation) in (gnu services messaging). Manually maintained
16451 @c documentation is better, so we shouldn't hesitate to edit below as
16452 @c needed. However if the change you want to make to this documentation
16453 @c can be done in an automated way, it's probably easier to change
16454 @c (generate-documentation) than to make it below and have to deal with
16455 @c the churn as Prosody updates.
16457 Available @code{prosody-configuration} fields are:
16459 @deftypevr {@code{prosody-configuration} parameter} package prosody
16460 The Prosody package.
16463 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
16464 Location of the Prosody data storage directory. See
16465 @url{https://prosody.im/doc/configure}.
16466 Defaults to @samp{"/var/lib/prosody"}.
16469 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
16470 Additional plugin directories. They are searched in all the specified
16471 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
16472 Defaults to @samp{()}.
16475 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
16476 Every virtual host and component needs a certificate so that clients and
16477 servers can securely verify its identity. Prosody will automatically load
16478 certificates/keys from the directory specified here.
16479 Defaults to @samp{"/etc/prosody/certs"}.
16482 @deftypevr {@code{prosody-configuration} parameter} string-list admins
16483 This is a list of accounts that are admins for the server. Note that you
16484 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
16485 @url{https://prosody.im/doc/creating_accounts}.
16486 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
16487 Defaults to @samp{()}.
16490 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
16491 Enable use of libevent for better performance under high load. See
16492 @url{https://prosody.im/doc/libevent}.
16493 Defaults to @samp{#f}.
16496 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
16497 This is the list of modules Prosody will load on startup. It looks for
16498 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
16499 Documentation on modules can be found at:
16500 @url{https://prosody.im/doc/modules}.
16501 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
16504 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
16505 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
16506 should you want to disable them then add them to this list.
16507 Defaults to @samp{()}.
16510 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
16511 Path to a text file where the shared groups are defined. If this path is
16512 empty then @samp{mod_groups} does nothing. See
16513 @url{https://prosody.im/doc/modules/mod_groups}.
16514 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
16517 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
16518 Disable account creation by default, for security. See
16519 @url{https://prosody.im/doc/creating_accounts}.
16520 Defaults to @samp{#f}.
16523 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
16524 These are the SSL/TLS-related settings. Most of them are disabled so to
16525 use Prosody's defaults. If you do not completely understand these options, do
16526 not add them to your config, it is easy to lower the security of your server
16527 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
16529 Available @code{ssl-configuration} fields are:
16531 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
16532 This determines what handshake to use.
16535 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
16536 Path to your private key file.
16539 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
16540 Path to your certificate file.
16543 @deftypevr {@code{ssl-configuration} parameter} file-object capath
16544 Path to directory containing root certificates that you wish Prosody to
16545 trust when verifying the certificates of remote servers.
16546 Defaults to @samp{"/etc/ssl/certs"}.
16549 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
16550 Path to a file containing root certificates that you wish Prosody to trust.
16551 Similar to @code{capath} but with all certificates concatenated together.
16554 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
16555 A list of verification options (these mostly map to OpenSSL's
16556 @code{set_verify()} flags).
16559 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
16560 A list of general options relating to SSL/TLS. These map to OpenSSL's
16561 @code{set_options()}. For a full list of options available in LuaSec, see the
16565 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
16566 How long a chain of certificate authorities to check when looking for a
16567 trusted root certificate.
16570 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
16571 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
16572 clients, and in what order.
16575 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
16576 A path to a file containing parameters for Diffie-Hellman key exchange. You
16577 can create such a file with:
16578 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
16581 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
16582 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
16583 @samp{"secp384r1"}.
16586 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
16587 A list of "extra" verification options.
16590 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
16591 Password for encrypted private keys.
16596 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
16597 Whether to force all client-to-server connections to be encrypted or not.
16598 See @url{https://prosody.im/doc/modules/mod_tls}.
16599 Defaults to @samp{#f}.
16602 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
16603 Set of mechanisms that will never be offered. See
16604 @url{https://prosody.im/doc/modules/mod_saslauth}.
16605 Defaults to @samp{("DIGEST-MD5")}.
16608 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
16609 Whether to force all server-to-server connections to be encrypted or not.
16610 See @url{https://prosody.im/doc/modules/mod_tls}.
16611 Defaults to @samp{#f}.
16614 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
16615 Whether to require encryption and certificate authentication. This
16616 provides ideal security, but requires servers you communicate with to support
16617 encryption AND present valid, trusted certificates. See
16618 @url{https://prosody.im/doc/s2s#security}.
16619 Defaults to @samp{#f}.
16622 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
16623 Many servers don't support encryption or have invalid or self-signed
16624 certificates. You can list domains here that will not be required to
16625 authenticate using certificates. They will be authenticated using DNS. See
16626 @url{https://prosody.im/doc/s2s#security}.
16627 Defaults to @samp{()}.
16630 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
16631 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
16632 valid certificates for some domains by specifying a list here. See
16633 @url{https://prosody.im/doc/s2s#security}.
16634 Defaults to @samp{()}.
16637 @deftypevr {@code{prosody-configuration} parameter} string authentication
16638 Select the authentication backend to use. The default provider stores
16639 passwords in plaintext and uses Prosody's configured data storage to store the
16640 authentication data. If you do not trust your server please see
16641 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
16642 about using the hashed backend. See also
16643 @url{https://prosody.im/doc/authentication}
16644 Defaults to @samp{"internal_plain"}.
16647 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
16648 Set logging options. Advanced logging configuration is not yet supported
16649 by the Prosody service. See @url{https://prosody.im/doc/logging}.
16650 Defaults to @samp{"*syslog"}.
16653 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
16654 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
16655 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
16658 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
16659 Maximum allowed size of the HTTP body (in bytes).
16662 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
16663 Some modules expose their own URL in various ways. This URL is built
16664 from the protocol, host and port used. If Prosody sits behind a proxy, the
16665 public URL will be @code{http-external-url} instead. See
16666 @url{https://prosody.im/doc/http#external_url}.
16669 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
16670 A host in Prosody is a domain on which user accounts can be created. For
16671 example if you want your users to have addresses like
16672 @samp{"john.smith@@example.com"} then you need to add a host
16673 @samp{"example.com"}. All options in this list will apply only to this host.
16675 Note: the name "virtual" host is used in configuration to avoid confusion with
16676 the actual physical host that Prosody is installed on. A single Prosody
16677 instance can serve many domains, each one defined as a VirtualHost entry in
16678 Prosody's configuration. Conversely a server that hosts a single domain would
16679 have just one VirtualHost entry.
16681 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
16683 Available @code{virtualhost-configuration} fields are:
16685 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:
16686 @deftypevr {@code{virtualhost-configuration} parameter} string domain
16687 Domain you wish Prosody to serve.
16692 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
16693 Components are extra services on a server which are available to clients,
16694 usually on a subdomain of the main server (such as
16695 @samp{"mycomponent.example.com"}). Example components might be chatroom
16696 servers, user directories, or gateways to other protocols.
16698 Internal components are implemented with Prosody-specific plugins. To add an
16699 internal component, you simply fill the hostname field, and the plugin you wish
16700 to use for the component.
16702 See @url{https://prosody.im/doc/components}.
16703 Defaults to @samp{()}.
16705 Available @code{int-component-configuration} fields are:
16707 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:
16708 @deftypevr {@code{int-component-configuration} parameter} string hostname
16709 Hostname of the component.
16712 @deftypevr {@code{int-component-configuration} parameter} string plugin
16713 Plugin you wish to use for the component.
16716 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
16717 Multi-user chat (MUC) is Prosody's module for allowing you to create
16718 hosted chatrooms/conferences for XMPP users.
16720 General information on setting up and using multi-user chatrooms can be found
16721 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
16722 which you should read if you are new to XMPP chatrooms.
16724 See also @url{https://prosody.im/doc/modules/mod_muc}.
16726 Available @code{mod-muc-configuration} fields are:
16728 @deftypevr {@code{mod-muc-configuration} parameter} string name
16729 The name to return in service discovery responses.
16730 Defaults to @samp{"Prosody Chatrooms"}.
16733 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
16734 If @samp{#t}, this will only allow admins to create new chatrooms.
16735 Otherwise anyone can create a room. The value @samp{"local"} restricts room
16736 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
16737 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
16738 restricts to service administrators only.
16739 Defaults to @samp{#f}.
16742 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
16743 Maximum number of history messages that will be sent to the member that has
16744 just joined the room.
16745 Defaults to @samp{20}.
16752 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
16753 External components use XEP-0114, which most standalone components
16754 support. To add an external component, you simply fill the hostname field. See
16755 @url{https://prosody.im/doc/components}.
16756 Defaults to @samp{()}.
16758 Available @code{ext-component-configuration} fields are:
16760 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:
16761 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
16762 Password which the component will use to log in.
16765 @deftypevr {@code{ext-component-configuration} parameter} string hostname
16766 Hostname of the component.
16771 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
16772 Port(s) Prosody listens on for component connections.
16773 Defaults to @samp{(5347)}.
16776 @deftypevr {@code{prosody-configuration} parameter} string component-interface
16777 Interface Prosody listens on for component connections.
16778 Defaults to @samp{"127.0.0.1"}.
16781 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
16782 Raw content that will be added to the configuration file.
16785 It could be that you just want to get a @code{prosody.cfg.lua}
16786 up and running. In that case, you can pass an
16787 @code{opaque-prosody-configuration} record as the value of
16788 @code{prosody-service-type}. As its name indicates, an opaque configuration
16789 does not have easy reflective capabilities.
16790 Available @code{opaque-prosody-configuration} fields are:
16792 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
16793 The prosody package.
16796 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
16797 The contents of the @code{prosody.cfg.lua} to use.
16800 For example, if your @code{prosody.cfg.lua} is just the empty
16801 string, you could instantiate a prosody service like this:
16804 (service prosody-service-type
16805 (opaque-prosody-configuration
16806 (prosody.cfg.lua "")))
16809 @c end of Prosody auto-generated documentation
16811 @subsubheading BitlBee Service
16813 @cindex IRC (Internet Relay Chat)
16814 @cindex IRC gateway
16815 @url{http://bitlbee.org,BitlBee} is a gateway that provides an IRC
16816 interface to a variety of messaging protocols such as XMPP.
16818 @defvr {Scheme Variable} bitlbee-service-type
16819 This is the service type for the @url{http://bitlbee.org,BitlBee} IRC
16820 gateway daemon. Its value is a @code{bitlbee-configuration} (see
16823 To have BitlBee listen on port 6667 on localhost, add this line to your
16827 (service bitlbee-service-type)
16831 @deftp {Data Type} bitlbee-configuration
16832 This is the configuration for BitlBee, with the following fields:
16835 @item @code{interface} (default: @code{"127.0.0.1"})
16836 @itemx @code{port} (default: @code{6667})
16837 Listen on the network interface corresponding to the IP address
16838 specified in @var{interface}, on @var{port}.
16840 When @var{interface} is @code{127.0.0.1}, only local clients can
16841 connect; when it is @code{0.0.0.0}, connections can come from any
16842 networking interface.
16844 @item @code{package} (default: @code{bitlbee})
16845 The BitlBee package to use.
16847 @item @code{plugins} (default: @code{'()})
16848 List of plugin packages to use---e.g., @code{bitlbee-discord}.
16850 @item @code{extra-settings} (default: @code{""})
16851 Configuration snippet added as-is to the BitlBee configuration file.
16855 @subsubheading Quassel Service
16857 @cindex IRC (Internet Relay Chat)
16858 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
16859 meaning that one or more clients can attach to and detach from the
16862 @defvr {Scheme Variable} quassel-service-type
16863 This is the service type for the @url{https://quassel-irc.org/,Quassel}
16864 IRC backend daemon. Its value is a @code{quassel-configuration}
16868 @deftp {Data Type} quassel-configuration
16869 This is the configuration for Quassel, with the following fields:
16872 @item @code{quassel} (default: @code{quassel})
16873 The Quassel package to use.
16875 @item @code{interface} (default: @code{"::,0.0.0.0"})
16876 @item @code{port} (default: @code{4242})
16877 Listen on the network interface(s) corresponding to the IPv4 or IPv6
16878 interfaces specified in the comma delimited @var{interface}, on
16881 @item @code{loglevel} (default: @code{"Info"})
16882 The level of logging desired. Accepted values are Debug, Info, Warning
16887 @node Telephony Services
16888 @subsection Telephony Services
16890 @cindex Murmur (VoIP server)
16891 @cindex VoIP server
16892 This section describes how to set up and run a Murmur server. Murmur is
16893 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
16896 @deftp {Data Type} murmur-configuration
16897 The service type for the Murmur server. An example configuration can
16901 (service murmur-service-type
16902 (murmur-configuration
16904 "Welcome to this Mumble server running on Guix!")
16905 (cert-required? #t) ;disallow text password logins
16906 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
16907 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
16910 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
16911 password with the command that is printed during the activation phase.
16913 It is recommended to register a normal Mumble user account
16914 and grant it admin or moderator rights.
16915 You can use the @code{mumble} client to
16916 login as new normal user, register yourself, and log out.
16917 For the next step login with the name @code{SuperUser} use
16918 the @code{SuperUser} password that you set previously,
16919 and grant your newly registered mumble user administrator or moderator
16920 rights and create some channels.
16922 Available @code{murmur-configuration} fields are:
16925 @item @code{package} (default: @code{mumble})
16926 Package that contains @code{bin/murmurd}.
16928 @item @code{user} (default: @code{"murmur"})
16929 User who will run the Murmur server.
16931 @item @code{group} (default: @code{"murmur"})
16932 Group of the user who will run the murmur server.
16934 @item @code{port} (default: @code{64738})
16935 Port on which the server will listen.
16937 @item @code{welcome-text} (default: @code{""})
16938 Welcome text sent to clients when they connect.
16940 @item @code{server-password} (default: @code{""})
16941 Password the clients have to enter in order to connect.
16943 @item @code{max-users} (default: @code{100})
16944 Maximum of users that can be connected to the server at once.
16946 @item @code{max-user-bandwidth} (default: @code{#f})
16947 Maximum voice traffic a user can send per second.
16949 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
16950 File name of the sqlite database.
16951 The service's user will become the owner of the directory.
16953 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
16954 File name of the log file.
16955 The service's user will become the owner of the directory.
16957 @item @code{autoban-attempts} (default: @code{10})
16958 Maximum number of logins a user can make in @code{autoban-timeframe}
16959 without getting auto banned for @code{autoban-time}.
16961 @item @code{autoban-timeframe} (default: @code{120})
16962 Timeframe for autoban in seconds.
16964 @item @code{autoban-time} (default: @code{300})
16965 Amount of time in seconds for which a client gets banned
16966 when violating the autoban limits.
16968 @item @code{opus-threshold} (default: @code{100})
16969 Percentage of clients that need to support opus
16970 before switching over to opus audio codec.
16972 @item @code{channel-nesting-limit} (default: @code{10})
16973 How deep channels can be nested at maximum.
16975 @item @code{channelname-regex} (default: @code{#f})
16976 A string in form of a Qt regular expression that channel names must conform to.
16978 @item @code{username-regex} (default: @code{#f})
16979 A string in form of a Qt regular expression that user names must conform to.
16981 @item @code{text-message-length} (default: @code{5000})
16982 Maximum size in bytes that a user can send in one text chat message.
16984 @item @code{image-message-length} (default: @code{(* 128 1024)})
16985 Maximum size in bytes that a user can send in one image message.
16987 @item @code{cert-required?} (default: @code{#f})
16988 If it is set to @code{#t} clients that use weak password authentification
16989 will not be accepted. Users must have completed the certificate wizard to join.
16991 @item @code{remember-channel?} (default: @code{#f})
16992 Should murmur remember the last channel each user was in when they disconnected
16993 and put them into the remembered channel when they rejoin.
16995 @item @code{allow-html?} (default: @code{#f})
16996 Should html be allowed in text messages, user comments, and channel descriptions.
16998 @item @code{allow-ping?} (default: @code{#f})
16999 Setting to true exposes the current user count, the maximum user count, and
17000 the server's maximum bandwidth per client to unauthenticated users. In the
17001 Mumble client, this information is shown in the Connect dialog.
17003 Disabling this setting will prevent public listing of the server.
17005 @item @code{bonjour?} (default: @code{#f})
17006 Should the server advertise itself in the local network through the bonjour protocol.
17008 @item @code{send-version?} (default: @code{#f})
17009 Should the murmur server version be exposed in ping requests.
17011 @item @code{log-days} (default: @code{31})
17012 Murmur also stores logs in the database, which are accessible via RPC.
17013 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
17014 or -1 to disable logging to the database.
17016 @item @code{obfuscate-ips?} (default: @code{#t})
17017 Should logged ips be obfuscated to protect the privacy of users.
17019 @item @code{ssl-cert} (default: @code{#f})
17020 File name of the SSL/TLS certificate used for encrypted connections.
17023 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
17025 @item @code{ssl-key} (default: @code{#f})
17026 Filepath to the ssl private key used for encrypted connections.
17028 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
17031 @item @code{ssl-dh-params} (default: @code{#f})
17032 File name of a PEM-encoded file with Diffie-Hellman parameters
17033 for the SSL/TLS encryption. Alternatively you set it to
17034 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
17035 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
17037 @item @code{ssl-ciphers} (default: @code{#f})
17038 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
17041 This option is specified using
17042 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
17043 OpenSSL cipher list notation}.
17045 It is recommended that you try your cipher string using 'openssl ciphers <string>'
17046 before setting it here, to get a feel for which cipher suites you will get.
17047 After setting this option, it is recommend that you inspect your Murmur log
17048 to ensure that Murmur is using the cipher suites that you expected it to.
17050 Note: Changing this option may impact the backwards compatibility of your
17051 Murmur server, and can remove the ability for older Mumble clients to be able
17054 @item @code{public-registration} (default: @code{#f})
17055 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
17057 You can optionally register your server in the public server list that the
17058 @code{mumble} client shows on startup.
17059 You cannot register your server if you have set a @code{server-password},
17060 or set @code{allow-ping} to @code{#f}.
17062 It might take a few hours until it shows up in the public list.
17064 @item @code{file} (default: @code{#f})
17065 Optional alternative override for this configuration.
17069 @deftp {Data Type} murmur-public-registration-configuration
17070 Configuration for public registration of a murmur service.
17074 This is a display name for your server. Not to be confused with the hostname.
17076 @item @code{password}
17077 A password to identify your registration.
17078 Subsequent updates will need the same password. Don't lose your password.
17081 This should be a @code{http://} or @code{https://} link to your web
17084 @item @code{hostname} (default: @code{#f})
17085 By default your server will be listed by its IP address.
17086 If it is set your server will be linked by this host name instead.
17092 @node Monitoring Services
17093 @subsection Monitoring Services
17095 @subsubheading Tailon Service
17097 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
17098 viewing and searching log files.
17100 The following example will configure the service with default values.
17101 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
17104 (service tailon-service-type)
17107 The following example customises more of the Tailon configuration,
17108 adding @command{sed} to the list of allowed commands.
17111 (service tailon-service-type
17112 (tailon-configuration
17114 (tailon-configuration-file
17115 (allowed-commands '("tail" "grep" "awk" "sed"))))))
17119 @deftp {Data Type} tailon-configuration
17120 Data type representing the configuration of Tailon.
17121 This type has the following parameters:
17124 @item @code{config-file} (default: @code{(tailon-configuration-file)})
17125 The configuration file to use for Tailon. This can be set to a
17126 @dfn{tailon-configuration-file} record value, or any gexp
17127 (@pxref{G-Expressions}).
17129 For example, to instead use a local file, the @code{local-file} function
17133 (service tailon-service-type
17134 (tailon-configuration
17135 (config-file (local-file "./my-tailon.conf"))))
17138 @item @code{package} (default: @code{tailon})
17139 The tailon package to use.
17144 @deftp {Data Type} tailon-configuration-file
17145 Data type representing the configuration options for Tailon.
17146 This type has the following parameters:
17149 @item @code{files} (default: @code{(list "/var/log")})
17150 List of files to display. The list can include strings for a single file
17151 or directory, or a list, where the first item is the name of a
17152 subsection, and the remaining items are the files or directories in that
17155 @item @code{bind} (default: @code{"localhost:8080"})
17156 Address and port to which Tailon should bind on.
17158 @item @code{relative-root} (default: @code{#f})
17159 URL path to use for Tailon, set to @code{#f} to not use a path.
17161 @item @code{allow-transfers?} (default: @code{#t})
17162 Allow downloading the log files in the web interface.
17164 @item @code{follow-names?} (default: @code{#t})
17165 Allow tailing of not-yet existent files.
17167 @item @code{tail-lines} (default: @code{200})
17168 Number of lines to read initially from each file.
17170 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
17171 Commands to allow running. By default, @code{sed} is disabled.
17173 @item @code{debug?} (default: @code{#f})
17174 Set @code{debug?} to @code{#t} to show debug messages.
17176 @item @code{wrap-lines} (default: @code{#t})
17177 Initial line wrapping state in the web interface. Set to @code{#t} to
17178 initially wrap lines (the default), or to @code{#f} to initially not
17181 @item @code{http-auth} (default: @code{#f})
17182 HTTP authentication type to use. Set to @code{#f} to disable
17183 authentication (the default). Supported values are @code{"digest"} or
17186 @item @code{users} (default: @code{#f})
17187 If HTTP authentication is enabled (see @code{http-auth}), access will be
17188 restricted to the credentials provided here. To configure users, use a
17189 list of pairs, where the first element of the pair is the username, and
17190 the 2nd element of the pair is the password.
17193 (tailon-configuration-file
17194 (http-auth "basic")
17195 (users '(("user1" . "password1")
17196 ("user2" . "password2"))))
17203 @subsubheading Darkstat Service
17205 Darkstat is a packet sniffer that captures network traffic, calculates
17206 statistics about usage, and serves reports over HTTP.
17208 @defvar {Scheme Variable} darkstat-service-type
17209 This is the service type for the
17210 @uref{https://unix4lyfe.org/darkstat/, darkstat}
17211 service, its value must be a @code{darkstat-configuration} record as in
17215 (service darkstat-service-type
17216 (darkstat-configuration
17217 (interface "eno1")))
17221 @deftp {Data Type} darkstat-configuration
17222 Data type representing the configuration of @command{darkstat}.
17225 @item @code{package} (default: @code{darkstat})
17226 The darkstat package to use.
17228 @item @code{interface}
17229 Capture traffic on the specified network interface.
17231 @item @code{port} (default: @code{"667"})
17232 Bind the web interface to the specified port.
17234 @item @code{bind-address} (default: @code{"127.0.0.1"})
17235 Bind the web interface to the specified address.
17237 @item @code{base} (default: @code{"/"})
17238 Specify the path of the base URL. This can be useful if
17239 @command{darkstat} is accessed via a reverse proxy.
17244 @subsubheading Prometheus Node Exporter Service
17246 @cindex prometheus-node-exporter
17247 The Prometheus ``node exporter'' makes hardware and operating system statistics
17248 provided by the Linux kernel available for the Prometheus monitoring system.
17249 This service should be deployed on all physical nodes and virtual machines,
17250 where monitoring these statistics is desirable.
17252 @defvar {Scheme variable} prometheus-node-exporter-service-type
17253 This is the service type for the
17254 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
17255 service, its value must be a @code{prometheus-node-exporter-configuration}
17256 record as in this example:
17259 (service prometheus-node-exporter-service-type
17260 (prometheus-node-exporter-configuration
17261 (web-listen-address ":9100")))
17265 @deftp {Data Type} prometheus-node-exporter-configuration
17266 Data type representing the configuration of @command{node_exporter}.
17269 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
17270 The prometheus-node-exporter package to use.
17272 @item @code{web-listen-address} (default: @code{":9100"})
17273 Bind the web interface to the specified address.
17278 @subsubheading Zabbix server
17279 @cindex zabbix zabbix-server
17280 Zabbix provides monitoring metrics, among others network utilization, CPU load
17281 and disk space consumption:
17284 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
17285 @item Auto-discovery of servers and network devices and interfaces.
17286 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
17287 @item Distributed monitoring with centralized web administration.
17288 @item Native high performance agents.
17289 @item SLA, and ITIL KPI metrics on reporting.
17290 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
17291 @item Remote command execution through Zabbix proxies.
17294 @c %start of fragment
17296 Available @code{zabbix-server-configuration} fields are:
17298 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
17299 The zabbix-server package.
17303 @deftypevr {@code{zabbix-server-configuration} parameter} string user
17304 User who will run the Zabbix server.
17306 Defaults to @samp{"zabbix"}.
17310 @deftypevr {@code{zabbix-server-configuration} parameter} group group
17311 Group who will run the Zabbix server.
17313 Defaults to @samp{"zabbix"}.
17317 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
17318 Database host name.
17320 Defaults to @samp{"127.0.0.1"}.
17324 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
17327 Defaults to @samp{"zabbix"}.
17331 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
17334 Defaults to @samp{"zabbix"}.
17338 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
17339 Database password. Please, use @code{include-files} with
17340 @code{DBPassword=SECRET} inside a specified file instead.
17342 Defaults to @samp{""}.
17346 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
17349 Defaults to @samp{5432}.
17353 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
17354 Specifies where log messages are written to:
17358 @code{system} - syslog.
17361 @code{file} - file specified with @code{log-file} parameter.
17364 @code{console} - standard output.
17368 Defaults to @samp{""}.
17372 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
17373 Log file name for @code{log-type} @code{file} parameter.
17375 Defaults to @samp{"/var/log/zabbix/server.log"}.
17379 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
17382 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
17386 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
17387 The location of certificate authority (CA) files for SSL server
17388 certificate verification.
17390 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
17394 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
17395 Location of SSL client certificates.
17397 Defaults to @samp{"/etc/ssl/certs"}.
17401 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
17402 Extra options will be appended to Zabbix server configuration file.
17404 Defaults to @samp{""}.
17408 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
17409 You may include individual files or all files in a directory in the
17410 configuration file.
17412 Defaults to @samp{()}.
17416 @c %end of fragment
17418 @subsubheading Zabbix agent
17419 @cindex zabbix zabbix-agent
17421 Zabbix agent gathers information for Zabbix server.
17423 @c %start of fragment
17425 Available @code{zabbix-agent-configuration} fields are:
17427 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
17428 The zabbix-agent package.
17432 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
17433 User who will run the Zabbix agent.
17435 Defaults to @samp{"zabbix"}.
17439 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
17440 Group who will run the Zabbix agent.
17442 Defaults to @samp{"zabbix"}.
17446 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
17447 Unique, case sensitive hostname which is required for active checks and
17448 must match hostname as configured on the server.
17450 Defaults to @samp{"Zabbix server"}.
17454 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
17455 Specifies where log messages are written to:
17459 @code{system} - syslog.
17462 @code{file} - file specified with @code{log-file} parameter.
17465 @code{console} - standard output.
17469 Defaults to @samp{""}.
17473 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
17474 Log file name for @code{log-type} @code{file} parameter.
17476 Defaults to @samp{"/var/log/zabbix/agent.log"}.
17480 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
17483 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
17487 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
17488 List of IP addresses, optionally in CIDR notation, or hostnames of
17489 Zabbix servers and Zabbix proxies. Incoming connections will be
17490 accepted only from the hosts listed here.
17492 Defaults to @samp{("127.0.0.1")}.
17496 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
17497 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
17498 proxies for active checks. If port is not specified, default port is
17499 used. If this parameter is not specified, active checks are disabled.
17501 Defaults to @samp{("127.0.0.1")}.
17505 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
17506 Extra options will be appended to Zabbix server configuration file.
17508 Defaults to @samp{""}.
17512 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
17513 You may include individual files or all files in a directory in the
17514 configuration file.
17516 Defaults to @samp{()}.
17520 @c %end of fragment
17522 @subsubheading Zabbix front-end
17523 @cindex zabbix zabbix-front-end
17525 This service provides a WEB interface to Zabbix server.
17527 @c %start of fragment
17529 Available @code{zabbix-front-end-configuration} fields are:
17531 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
17532 NGINX configuration.
17536 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
17537 Database host name.
17539 Defaults to @samp{"localhost"}.
17543 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
17546 Defaults to @samp{5432}.
17550 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
17553 Defaults to @samp{"zabbix"}.
17557 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
17560 Defaults to @samp{"zabbix"}.
17564 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
17565 Database password. Please, use @code{db-secret-file} instead.
17567 Defaults to @samp{""}.
17571 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
17572 Secret file which will be appended to @file{zabbix.conf.php} file. This
17573 file contains credentials for use by Zabbix front-end. You are expected
17574 to create it manually.
17576 Defaults to @samp{""}.
17580 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
17581 Zabbix server hostname.
17583 Defaults to @samp{"localhost"}.
17587 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
17588 Zabbix server port.
17590 Defaults to @samp{10051}.
17595 @c %end of fragment
17597 @node Kerberos Services
17598 @subsection Kerberos Services
17601 The @code{(gnu services kerberos)} module provides services relating to
17602 the authentication protocol @dfn{Kerberos}.
17604 @subsubheading Krb5 Service
17606 Programs using a Kerberos client library normally
17607 expect a configuration file in @file{/etc/krb5.conf}.
17608 This service generates such a file from a definition provided in the
17609 operating system declaration.
17610 It does not cause any daemon to be started.
17612 No ``keytab'' files are provided by this service---you must explicitly create them.
17613 This service is known to work with the MIT client library, @code{mit-krb5}.
17614 Other implementations have not been tested.
17616 @defvr {Scheme Variable} krb5-service-type
17617 A service type for Kerberos 5 clients.
17621 Here is an example of its use:
17623 (service krb5-service-type
17624 (krb5-configuration
17625 (default-realm "EXAMPLE.COM")
17626 (allow-weak-crypto? #t)
17629 (name "EXAMPLE.COM")
17630 (admin-server "groucho.example.com")
17631 (kdc "karl.example.com"))
17634 (admin-server "kerb-admin.argrx.edu")
17635 (kdc "keys.argrx.edu"))))))
17639 This example provides a Kerberos@tie{}5 client configuration which:
17641 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
17642 of which have distinct administration servers and key distribution centers;
17643 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
17644 specified by clients;
17645 @item Accepts services which only support encryption types known to be weak.
17648 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
17649 Only the most commonly used ones are described here.
17650 For a full list, and more detailed explanation of each, see the MIT
17651 @uref{http://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
17655 @deftp {Data Type} krb5-realm
17656 @cindex realm, kerberos
17659 This field is a string identifying the name of the realm.
17660 A common convention is to use the fully qualified DNS name of your organization,
17661 converted to upper case.
17663 @item @code{admin-server}
17664 This field is a string identifying the host where the administration server is
17668 This field is a string identifying the key distribution center
17673 @deftp {Data Type} krb5-configuration
17676 @item @code{allow-weak-crypto?} (default: @code{#f})
17677 If this flag is @code{#t} then services which only offer encryption algorithms
17678 known to be weak will be accepted.
17680 @item @code{default-realm} (default: @code{#f})
17681 This field should be a string identifying the default Kerberos
17682 realm for the client.
17683 You should set this field to the name of your Kerberos realm.
17684 If this value is @code{#f}
17685 then a realm must be specified with every Kerberos principal when invoking programs
17686 such as @command{kinit}.
17688 @item @code{realms}
17689 This should be a non-empty list of @code{krb5-realm} objects, which clients may
17691 Normally, one of them will have a @code{name} field matching the @code{default-realm}
17697 @subsubheading PAM krb5 Service
17700 The @code{pam-krb5} service allows for login authentication and password
17701 management via Kerberos.
17702 You will need this service if you want PAM enabled applications to authenticate
17703 users using Kerberos.
17705 @defvr {Scheme Variable} pam-krb5-service-type
17706 A service type for the Kerberos 5 PAM module.
17709 @deftp {Data Type} pam-krb5-configuration
17710 Data type representing the configuration of the Kerberos 5 PAM module
17711 This type has the following parameters:
17713 @item @code{pam-krb5} (default: @code{pam-krb5})
17714 The pam-krb5 package to use.
17716 @item @code{minimum-uid} (default: @code{1000})
17717 The smallest user ID for which Kerberos authentications should be attempted.
17718 Local accounts with lower values will silently fail to authenticate.
17723 @node LDAP Services
17724 @subsection LDAP Services
17726 @cindex nslcd, LDAP service
17728 The @code{(gnu services authentication)} module provides the
17729 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
17730 server. In addition to configuring the service itself, you may want to add
17731 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
17732 Switch} for detailed information.
17734 Here is a simple operating system declaration with a default configuration of
17735 the @code{nslcd-service-type} and a Name Service Switch configuration that
17736 consults the @code{ldap} name service last:
17739 (use-service-modules authentication)
17740 (use-modules (gnu system nss))
17746 (service nslcd-service-type)
17747 (service dhcp-client-service-type)
17749 (name-service-switch
17750 (let ((services (list (name-service (name "db"))
17751 (name-service (name "files"))
17752 (name-service (name "ldap")))))
17753 (name-service-switch
17754 (inherit %mdns-host-lookup-nss)
17755 (password services)
17758 (netgroup services)
17759 (gshadow services)))))
17762 @c %start of generated documentation for nslcd-configuration
17764 Available @code{nslcd-configuration} fields are:
17766 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
17767 The @code{nss-pam-ldapd} package to use.
17771 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
17772 The number of threads to start that can handle requests and perform LDAP
17773 queries. Each thread opens a separate connection to the LDAP server.
17774 The default is to start 5 threads.
17776 Defaults to @samp{disabled}.
17780 @deftypevr {@code{nslcd-configuration} parameter} string uid
17781 This specifies the user id with which the daemon should be run.
17783 Defaults to @samp{"nslcd"}.
17787 @deftypevr {@code{nslcd-configuration} parameter} string gid
17788 This specifies the group id with which the daemon should be run.
17790 Defaults to @samp{"nslcd"}.
17794 @deftypevr {@code{nslcd-configuration} parameter} log-option log
17795 This option controls the way logging is done via a list containing
17796 SCHEME and LEVEL. The SCHEME argument may either be the symbols "none"
17797 or "syslog", or an absolute file name. The LEVEL argument is optional
17798 and specifies the log level. The log level may be one of the following
17799 symbols: "crit", "error", "warning", "notice", "info" or "debug". All
17800 messages with the specified log level or higher are logged.
17802 Defaults to @samp{("/var/log/nslcd" info)}.
17806 @deftypevr {@code{nslcd-configuration} parameter} list uri
17807 The list of LDAP server URIs. Normally, only the first server will be
17808 used with the following servers as fall-back.
17810 Defaults to @samp{("ldap://localhost:389/")}.
17814 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
17815 The version of the LDAP protocol to use. The default is to use the
17816 maximum version supported by the LDAP library.
17818 Defaults to @samp{disabled}.
17822 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
17823 Specifies the distinguished name with which to bind to the directory
17824 server for lookups. The default is to bind anonymously.
17826 Defaults to @samp{disabled}.
17830 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
17831 Specifies the credentials with which to bind. This option is only
17832 applicable when used with binddn.
17834 Defaults to @samp{disabled}.
17838 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
17839 Specifies the distinguished name to use when the root user tries to
17840 modify a user's password using the PAM module.
17842 Defaults to @samp{disabled}.
17846 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
17847 Specifies the credentials with which to bind if the root user tries to
17848 change a user's password. This option is only applicable when used with
17851 Defaults to @samp{disabled}.
17855 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
17856 Specifies the SASL mechanism to be used when performing SASL
17859 Defaults to @samp{disabled}.
17863 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
17864 Specifies the SASL realm to be used when performing SASL authentication.
17866 Defaults to @samp{disabled}.
17870 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
17871 Specifies the authentication identity to be used when performing SASL
17874 Defaults to @samp{disabled}.
17878 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
17879 Specifies the authorization identity to be used when performing SASL
17882 Defaults to @samp{disabled}.
17886 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
17887 Determines whether the LDAP server host name should be canonicalised. If
17888 this is enabled the LDAP library will do a reverse host name lookup. By
17889 default, it is left up to the LDAP library whether this check is
17892 Defaults to @samp{disabled}.
17896 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
17897 Set the name for the GSS-API Kerberos credentials cache.
17899 Defaults to @samp{disabled}.
17903 @deftypevr {@code{nslcd-configuration} parameter} string base
17904 The directory search base.
17906 Defaults to @samp{"dc=example,dc=com"}.
17910 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
17911 Specifies the search scope (subtree, onelevel, base or children). The
17912 default scope is subtree; base scope is almost never useful for name
17913 service lookups; children scope is not supported on all servers.
17915 Defaults to @samp{(subtree)}.
17919 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
17920 Specifies the policy for dereferencing aliases. The default policy is
17921 to never dereference aliases.
17923 Defaults to @samp{disabled}.
17927 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
17928 Specifies whether automatic referral chasing should be enabled. The
17929 default behaviour is to chase referrals.
17931 Defaults to @samp{disabled}.
17935 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
17936 This option allows for custom attributes to be looked up instead of the
17937 default RFC 2307 attributes. It is a list of maps, each consisting of
17938 the name of a map, the RFC 2307 attribute to match and the query
17939 expression for the attribute as it is available in the directory.
17941 Defaults to @samp{()}.
17945 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
17946 A list of filters consisting of the name of a map to which the filter
17947 applies and an LDAP search filter expression.
17949 Defaults to @samp{()}.
17953 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
17954 Specifies the time limit in seconds to use when connecting to the
17955 directory server. The default value is 10 seconds.
17957 Defaults to @samp{disabled}.
17961 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
17962 Specifies the time limit (in seconds) to wait for a response from the
17963 LDAP server. A value of zero, which is the default, is to wait
17964 indefinitely for searches to be completed.
17966 Defaults to @samp{disabled}.
17970 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
17971 Specifies the period if inactivity (in seconds) after which the con‐
17972 nection to the LDAP server will be closed. The default is not to time
17975 Defaults to @samp{disabled}.
17979 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
17980 Specifies the number of seconds to sleep when connecting to all LDAP
17981 servers fails. By default one second is waited between the first
17982 failure and the first retry.
17984 Defaults to @samp{disabled}.
17988 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
17989 Specifies the time after which the LDAP server is considered to be
17990 permanently unavailable. Once this time is reached retries will be done
17991 only once per this time period. The default value is 10 seconds.
17993 Defaults to @samp{disabled}.
17997 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
17998 Specifies whether to use SSL/TLS or not (the default is not to). If
17999 'start-tls is specified then StartTLS is used rather than raw LDAP over
18002 Defaults to @samp{disabled}.
18006 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
18007 Specifies what checks to perform on a server-supplied certificate. The
18008 meaning of the values is described in the ldap.conf(5) manual page.
18010 Defaults to @samp{disabled}.
18014 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
18015 Specifies the directory containing X.509 certificates for peer authen‐
18016 tication. This parameter is ignored when using GnuTLS.
18018 Defaults to @samp{disabled}.
18022 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
18023 Specifies the path to the X.509 certificate for peer authentication.
18025 Defaults to @samp{disabled}.
18029 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
18030 Specifies the path to an entropy source. This parameter is ignored when
18033 Defaults to @samp{disabled}.
18037 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
18038 Specifies the ciphers to use for TLS as a string.
18040 Defaults to @samp{disabled}.
18044 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
18045 Specifies the path to the file containing the local certificate for
18046 client TLS authentication.
18048 Defaults to @samp{disabled}.
18052 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
18053 Specifies the path to the file containing the private key for client TLS
18056 Defaults to @samp{disabled}.
18060 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
18061 Set this to a number greater than 0 to request paged results from the
18062 LDAP server in accordance with RFC2696. The default (0) is to not
18063 request paged results.
18065 Defaults to @samp{disabled}.
18069 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
18070 This option prevents group membership lookups through LDAP for the
18071 specified users. Alternatively, the value 'all-local may be used. With
18072 that value nslcd builds a full list of non-LDAP users on startup.
18074 Defaults to @samp{disabled}.
18078 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
18079 This option ensures that LDAP users with a numeric user id lower than
18080 the specified value are ignored.
18082 Defaults to @samp{disabled}.
18086 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
18087 This option specifies an offset that is added to all LDAP numeric user
18088 ids. This can be used to avoid user id collisions with local users.
18090 Defaults to @samp{disabled}.
18094 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
18095 This option specifies an offset that is added to all LDAP numeric group
18096 ids. This can be used to avoid user id collisions with local groups.
18098 Defaults to @samp{disabled}.
18102 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
18103 If this option is set, the member attribute of a group may point to
18104 another group. Members of nested groups are also returned in the higher
18105 level group and parent groups are returned when finding groups for a
18106 specific user. The default is not to perform extra searches for nested
18109 Defaults to @samp{disabled}.
18113 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
18114 If this option is set, the group member list is not retrieved when
18115 looking up groups. Lookups for finding which groups a user belongs to
18116 will remain functional so the user will likely still get the correct
18117 groups assigned on login.
18119 Defaults to @samp{disabled}.
18123 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
18124 If this option is set, functions which cause all user/group entries to
18125 be loaded from the directory will not succeed in doing so. This can
18126 dramatically reduce LDAP server load in situations where there are a
18127 great number of users and/or groups. This option is not recommended for
18128 most configurations.
18130 Defaults to @samp{disabled}.
18134 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
18135 This option can be used to specify how user and group names are verified
18136 within the system. This pattern is used to check all user and group
18137 names that are requested and returned from LDAP.
18139 Defaults to @samp{disabled}.
18143 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
18144 This specifies whether or not to perform searches using case-insensitive
18145 matching. Enabling this could open up the system to authorization
18146 bypass vulnerabilities and introduce nscd cache poisoning
18147 vulnerabilities which allow denial of service.
18149 Defaults to @samp{disabled}.
18153 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
18154 This option specifies whether password policy controls are requested and
18155 handled from the LDAP server when performing user authentication.
18157 Defaults to @samp{disabled}.
18161 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
18162 By default nslcd performs an LDAP search with the user's credentials
18163 after BIND (authentication) to ensure that the BIND operation was
18164 successful. The default search is a simple check to see if the user's
18165 DN exists. A search filter can be specified that will be used instead.
18166 It should return at least one entry.
18168 Defaults to @samp{disabled}.
18172 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
18173 This option allows flexible fine tuning of the authorisation check that
18174 should be performed. The search filter specified is executed and if any
18175 entries match, access is granted, otherwise access is denied.
18177 Defaults to @samp{disabled}.
18181 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
18182 If this option is set password modification using pam_ldap will be
18183 denied and the specified message will be presented to the user instead.
18184 The message can be used to direct the user to an alternative means of
18185 changing their password.
18187 Defaults to @samp{disabled}.
18191 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
18192 List of pam service names for which LDAP authentication should suffice.
18194 Defaults to @samp{()}.
18198 @c %end of generated documentation for nslcd-configuration
18202 @subsection Web Services
18207 The @code{(gnu services web)} module provides the Apache HTTP Server,
18208 the nginx web server, and also a fastcgi wrapper daemon.
18210 @subsubheading Apache HTTP Server
18212 @deffn {Scheme Variable} httpd-service-type
18213 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
18214 (@dfn{httpd}). The value for this service type is a
18215 @code{httpd-configuration} record.
18217 A simple example configuration is given below.
18220 (service httpd-service-type
18221 (httpd-configuration
18224 (server-name "www.example.com")
18225 (document-root "/srv/http/www.example.com")))))
18228 Other services can also extend the @code{httpd-service-type} to add to
18232 (simple-service 'my-extra-server httpd-service-type
18236 (list (string-append
18237 "ServerName "www.example.com
18238 DocumentRoot \"/srv/http/www.example.com\"")))))
18242 The details for the @code{httpd-configuration}, @code{httpd-module},
18243 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
18246 @deffn {Data Type} httpd-configuration
18247 This data type represents the configuration for the httpd service.
18250 @item @code{package} (default: @code{httpd})
18251 The httpd package to use.
18253 @item @code{pid-file} (default: @code{"/var/run/httpd"})
18254 The pid file used by the shepherd-service.
18256 @item @code{config} (default: @code{(httpd-config-file)})
18257 The configuration file to use with the httpd service. The default value
18258 is a @code{httpd-config-file} record, but this can also be a different
18259 G-expression that generates a file, for example a @code{plain-file}. A
18260 file outside of the store can also be specified through a string.
18265 @deffn {Data Type} httpd-module
18266 This data type represents a module for the httpd service.
18270 The name of the module.
18273 The file for the module. This can be relative to the httpd package being
18274 used, the absolute location of a file, or a G-expression for a file
18275 within the store, for example @code{(file-append mod-wsgi
18276 "/modules/mod_wsgi.so")}.
18281 @defvr {Scheme Variable} %default-httpd-modules
18282 A default list of @code{httpd-module} objects.
18285 @deffn {Data Type} httpd-config-file
18286 This data type represents a configuration file for the httpd service.
18289 @item @code{modules} (default: @code{%default-httpd-modules})
18290 The modules to load. Additional modules can be added here, or loaded by
18291 additional configuration.
18293 For example, in order to handle requests for PHP files, you can use Apache’s
18294 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
18297 (service httpd-service-type
18298 (httpd-configuration
18303 (name "proxy_module")
18304 (file "modules/mod_proxy.so"))
18306 (name "proxy_fcgi_module")
18307 (file "modules/mod_proxy_fcgi.so"))
18308 %default-httpd-modules))
18309 (extra-config (list "\
18310 <FilesMatch \\.php$>
18311 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
18312 </FilesMatch>"))))))
18313 (service php-fpm-service-type
18314 (php-fpm-configuration
18315 (socket "/var/run/php-fpm.sock")
18316 (socket-group "httpd")))
18319 @item @code{server-root} (default: @code{httpd})
18320 The @code{ServerRoot} in the configuration file, defaults to the httpd
18321 package. Directives including @code{Include} and @code{LoadModule} are
18322 taken as relative to the server root.
18324 @item @code{server-name} (default: @code{#f})
18325 The @code{ServerName} in the configuration file, used to specify the
18326 request scheme, hostname and port that the server uses to identify
18329 This doesn't need to be set in the server config, and can be specifyed
18330 in virtual hosts. The default is @code{#f} to not specify a
18333 @item @code{document-root} (default: @code{"/srv/http"})
18334 The @code{DocumentRoot} from which files will be served.
18336 @item @code{listen} (default: @code{'("80")})
18337 The list of values for the @code{Listen} directives in the config
18338 file. The value should be a list of strings, when each string can
18339 specify the port number to listen on, and optionally the IP address and
18342 @item @code{pid-file} (default: @code{"/var/run/httpd"})
18343 The @code{PidFile} to use. This should match the @code{pid-file} set in
18344 the @code{httpd-configuration} so that the Shepherd service is
18345 configured correctly.
18347 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
18348 The @code{ErrorLog} to which the server will log errors.
18350 @item @code{user} (default: @code{"httpd"})
18351 The @code{User} which the server will answer requests as.
18353 @item @code{group} (default: @code{"httpd"})
18354 The @code{Group} which the server will answer requests as.
18356 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
18357 A flat list of strings and G-expressions which will be added to the end
18358 of the configuration file.
18360 Any values which the service is extended with will be appended to this
18366 @deffn {Data Type} httpd-virtualhost
18367 This data type represents a virtualhost configuration block for the httpd service.
18369 These should be added to the extra-config for the httpd-service.
18372 (simple-service 'my-extra-server httpd-service-type
18376 (list (string-append
18377 "ServerName "www.example.com
18378 DocumentRoot \"/srv/http/www.example.com\"")))))
18382 @item @code{addresses-and-ports}
18383 The addresses and ports for the @code{VirtualHost} directive.
18385 @item @code{contents}
18386 The contents of the @code{VirtualHost} directive, this should be a list
18387 of strings and G-expressions.
18392 @subsubheading NGINX
18394 @deffn {Scheme Variable} nginx-service-type
18395 Service type for the @uref{https://nginx.org/,NGinx} web server. The
18396 value for this service type is a @code{<nginx-configuration>} record.
18398 A simple example configuration is given below.
18401 (service nginx-service-type
18402 (nginx-configuration
18404 (list (nginx-server-configuration
18405 (server-name '("www.example.com"))
18406 (root "/srv/http/www.example.com"))))))
18409 In addition to adding server blocks to the service configuration
18410 directly, this service can be extended by other services to add server
18411 blocks, as in this example:
18414 (simple-service 'my-extra-server nginx-service-type
18415 (list (nginx-server-configuration
18416 (root "/srv/http/extra-website")
18417 (try-files (list "$uri" "$uri/index.html")))))
18421 At startup, @command{nginx} has not yet read its configuration file, so
18422 it uses a default file to log error messages. If it fails to load its
18423 configuration file, that is where error messages are logged. After the
18424 configuration file is loaded, the default error log file changes as per
18425 configuration. In our case, startup error messages can be found in
18426 @file{/var/run/nginx/logs/error.log}, and after configuration in
18427 @file{/var/log/nginx/error.log}. The second location can be changed
18428 with the @var{log-directory} configuration option.
18430 @deffn {Data Type} nginx-configuration
18431 This data type represents the configuration for NGinx. Some
18432 configuration can be done through this and the other provided record
18433 types, or alternatively, a config file can be provided.
18436 @item @code{nginx} (default: @code{nginx})
18437 The nginx package to use.
18439 @item @code{log-directory} (default: @code{"/var/log/nginx"})
18440 The directory to which NGinx will write log files.
18442 @item @code{run-directory} (default: @code{"/var/run/nginx"})
18443 The directory in which NGinx will create a pid file, and write temporary
18446 @item @code{server-blocks} (default: @code{'()})
18447 A list of @dfn{server blocks} to create in the generated configuration
18448 file, the elements should be of type
18449 @code{<nginx-server-configuration>}.
18451 The following example would setup NGinx to serve @code{www.example.com}
18452 from the @code{/srv/http/www.example.com} directory, without using
18455 (service nginx-service-type
18456 (nginx-configuration
18458 (list (nginx-server-configuration
18459 (server-name '("www.example.com"))
18460 (root "/srv/http/www.example.com"))))))
18463 @item @code{upstream-blocks} (default: @code{'()})
18464 A list of @dfn{upstream blocks} to create in the generated configuration
18465 file, the elements should be of type
18466 @code{<nginx-upstream-configuration>}.
18468 Configuring upstreams through the @code{upstream-blocks} can be useful
18469 when combined with @code{locations} in the
18470 @code{<nginx-server-configuration>} records. The following example
18471 creates a server configuration with one location configuration, that
18472 will proxy requests to a upstream configuration, which will handle
18473 requests with two servers.
18478 (nginx-configuration
18480 (list (nginx-server-configuration
18481 (server-name '("www.example.com"))
18482 (root "/srv/http/www.example.com")
18485 (nginx-location-configuration
18487 (body '("proxy_pass http://server-proxy;"))))))))
18489 (list (nginx-upstream-configuration
18490 (name "server-proxy")
18491 (servers (list "server1.example.com"
18492 "server2.example.com")))))))
18495 @item @code{file} (default: @code{#f})
18496 If a configuration @var{file} is provided, this will be used, rather than
18497 generating a configuration file from the provided @code{log-directory},
18498 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
18499 proper operation, these arguments should match what is in @var{file} to ensure
18500 that the directories are created when the service is activated.
18502 This can be useful if you have an existing configuration file, or it's
18503 not possible to do what is required through the other parts of the
18504 nginx-configuration record.
18506 @item @code{server-names-hash-bucket-size} (default: @code{#f})
18507 Bucket size for the server names hash tables, defaults to @code{#f} to
18508 use the size of the processors cache line.
18510 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
18511 Maximum bucket size for the server names hash tables.
18513 @item @code{extra-content} (default: @code{""})
18514 Extra content for the @code{http} block. Should be string or a string
18515 valued G-expression.
18520 @deftp {Data Type} nginx-server-configuration
18521 Data type representing the configuration of an nginx server block.
18522 This type has the following parameters:
18525 @item @code{listen} (default: @code{'("80" "443 ssl")})
18526 Each @code{listen} directive sets the address and port for IP, or the
18527 path for a UNIX-domain socket on which the server will accept requests.
18528 Both address and port, or only address or only port can be specified.
18529 An address may also be a hostname, for example:
18532 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
18535 @item @code{server-name} (default: @code{(list 'default)})
18536 A list of server names this server represents. @code{'default} represents the
18537 default server for connections matching no other server.
18539 @item @code{root} (default: @code{"/srv/http"})
18540 Root of the website nginx will serve.
18542 @item @code{locations} (default: @code{'()})
18543 A list of @dfn{nginx-location-configuration} or
18544 @dfn{nginx-named-location-configuration} records to use within this
18547 @item @code{index} (default: @code{(list "index.html")})
18548 Index files to look for when clients ask for a directory. If it cannot be found,
18549 Nginx will send the list of files in the directory.
18551 @item @code{try-files} (default: @code{'()})
18552 A list of files whose existence is checked in the specified order.
18553 @code{nginx} will use the first file it finds to process the request.
18555 @item @code{ssl-certificate} (default: @code{#f})
18556 Where to find the certificate for secure connections. Set it to @code{#f} if
18557 you don't have a certificate or you don't want to use HTTPS.
18559 @item @code{ssl-certificate-key} (default: @code{#f})
18560 Where to find the private key for secure connections. Set it to @code{#f} if
18561 you don't have a key or you don't want to use HTTPS.
18563 @item @code{server-tokens?} (default: @code{#f})
18564 Whether the server should add its configuration to response.
18566 @item @code{raw-content} (default: @code{'()})
18567 A list of raw lines added to the server block.
18572 @deftp {Data Type} nginx-upstream-configuration
18573 Data type representing the configuration of an nginx @code{upstream}
18574 block. This type has the following parameters:
18578 Name for this group of servers.
18580 @item @code{servers}
18581 Specify the addresses of the servers in the group. The address can be
18582 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
18583 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
18584 prefix @samp{unix:}. For addresses using an IP address or domain name,
18585 the default port is 80, and a different port can be specified
18591 @deftp {Data Type} nginx-location-configuration
18592 Data type representing the configuration of an nginx @code{location}
18593 block. This type has the following parameters:
18597 URI which this location block matches.
18599 @anchor{nginx-location-configuration body}
18601 Body of the location block, specified as a list of strings. This can contain
18603 configuration directives. For example, to pass requests to a upstream
18604 server group defined using an @code{nginx-upstream-configuration} block,
18605 the following directive would be specified in the body @samp{(list "proxy_pass
18606 http://upstream-name;")}.
18611 @deftp {Data Type} nginx-named-location-configuration
18612 Data type representing the configuration of an nginx named location
18613 block. Named location blocks are used for request redirection, and not
18614 used for regular request processing. This type has the following
18619 Name to identify this location block.
18622 @xref{nginx-location-configuration body}, as the body for named location
18623 blocks can be used in a similar way to the
18624 @code{nginx-location-configuration body}. One restriction is that the
18625 body of a named location block cannot contain location blocks.
18630 @subsubheading Varnish Cache
18632 Varnish is a fast cache server that sits in between web applications
18633 and end users. It proxies requests from clients and caches the
18634 accessed URLs such that multiple requests for the same resource only
18635 creates one request to the back-end.
18637 @defvr {Scheme Variable} varnish-service-type
18638 Service type for the Varnish daemon.
18641 @deftp {Data Type} varnish-configuration
18642 Data type representing the @code{varnish} service configuration.
18643 This type has the following parameters:
18646 @item @code{package} (default: @code{varnish})
18647 The Varnish package to use.
18649 @item @code{name} (default: @code{"default"})
18650 A name for this Varnish instance. Varnish will create a directory in
18651 @file{/var/varnish/} with this name and keep temporary files there. If
18652 the name starts with a forward slash, it is interpreted as an absolute
18655 Pass the @code{-n} argument to other Varnish programs to connect to the
18656 named instance, e.g.@: @command{varnishncsa -n default}.
18658 @item @code{backend} (default: @code{"localhost:8080"})
18659 The backend to use. This option has no effect if @code{vcl} is set.
18661 @item @code{vcl} (default: #f)
18662 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
18663 is @code{#f}, Varnish will proxy @code{backend} using the default
18664 configuration. Otherwise this must be a file-like object with valid
18667 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
18668 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
18669 can do something along these lines:
18672 (define %gnu-mirror
18676 backend gnu @{ .host = "www.gnu.org"; @}"))
18680 (services (cons (service varnish-service-type
18681 (varnish-configuration
18683 (vcl %gnu-mirror)))
18687 The configuration of an already running Varnish instance can be inspected
18688 and changed using the @command{varnishadm} program.
18690 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
18691 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
18692 comprehensive documentation on Varnish and its configuration language.
18694 @item @code{listen} (default: @code{'("localhost:80")})
18695 List of addresses Varnish will listen on.
18697 @item @code{storage} (default: @code{'("malloc,128m")})
18698 List of storage backends that will be available in VCL.
18700 @item @code{parameters} (default: @code{'()})
18701 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
18703 @item @code{extra-options} (default: @code{'()})
18704 Additional arguments to pass to the @command{varnishd} process.
18709 @subsubheading FastCGI
18712 FastCGI is an interface between the front-end and the back-end of a web
18713 service. It is a somewhat legacy facility; new web services should
18714 generally just talk HTTP between the front-end and the back-end.
18715 However there are a number of back-end services such as PHP or the
18716 optimized HTTP Git repository access that use FastCGI, so we have
18717 support for it in Guix.
18719 To use FastCGI, you configure the front-end web server (e.g., nginx) to
18720 dispatch some subset of its requests to the fastcgi backend, which
18721 listens on a local TCP or UNIX socket. There is an intermediary
18722 @code{fcgiwrap} program that sits between the actual backend process and
18723 the web server. The front-end indicates which backend program to run,
18724 passing that information to the @code{fcgiwrap} process.
18726 @defvr {Scheme Variable} fcgiwrap-service-type
18727 A service type for the @code{fcgiwrap} FastCGI proxy.
18730 @deftp {Data Type} fcgiwrap-configuration
18731 Data type representing the configuration of the @code{fcgiwrap} service.
18732 This type has the following parameters:
18734 @item @code{package} (default: @code{fcgiwrap})
18735 The fcgiwrap package to use.
18737 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
18738 The socket on which the @code{fcgiwrap} process should listen, as a
18739 string. Valid @var{socket} values include
18740 @code{unix:@var{/path/to/unix/socket}},
18741 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
18742 @code{tcp6:[@var{ipv6_addr}]:port}.
18744 @item @code{user} (default: @code{fcgiwrap})
18745 @itemx @code{group} (default: @code{fcgiwrap})
18746 The user and group names, as strings, under which to run the
18747 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
18748 the user asks for the specific user or group names @code{fcgiwrap} that
18749 the corresponding user and/or group is present on the system.
18751 It is possible to configure a FastCGI-backed web service to pass HTTP
18752 authentication information from the front-end to the back-end, and to
18753 allow @code{fcgiwrap} to run the back-end process as a corresponding
18754 local user. To enable this capability on the back-end., run
18755 @code{fcgiwrap} as the @code{root} user and group. Note that this
18756 capability also has to be configured on the front-end as well.
18761 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
18762 with some additional features useful for sites of any size.
18764 These features include:
18766 @item Adaptive process spawning
18767 @item Basic statistics (similar to Apache's mod_status)
18768 @item Advanced process management with graceful stop/start
18769 @item Ability to start workers with different uid/gid/chroot/environment
18770 and different php.ini (replaces safe_mode)
18771 @item Stdout & stderr logging
18772 @item Emergency restart in case of accidental opcode cache destruction
18773 @item Accelerated upload support
18774 @item Support for a "slowlog"
18775 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
18776 a special function to finish request & flush all data while continuing to do
18777 something time-consuming (video converting, stats processing, etc.)
18779 ...@: and much more.
18781 @defvr {Scheme Variable} php-fpm-service-type
18782 A Service type for @code{php-fpm}.
18785 @deftp {Data Type} php-fpm-configuration
18786 Data Type for php-fpm service configuration.
18788 @item @code{php} (default: @code{php})
18789 The php package to use.
18790 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
18791 The address on which to accept FastCGI requests. Valid syntaxes are:
18793 @item @code{"ip.add.re.ss:port"}
18794 Listen on a TCP socket to a specific address on a specific port.
18795 @item @code{"port"}
18796 Listen on a TCP socket to all addresses on a specific port.
18797 @item @code{"/path/to/unix/socket"}
18798 Listen on a unix socket.
18801 @item @code{user} (default: @code{php-fpm})
18802 User who will own the php worker processes.
18803 @item @code{group} (default: @code{php-fpm})
18804 Group of the worker processes.
18805 @item @code{socket-user} (default: @code{php-fpm})
18806 User who can speak to the php-fpm socket.
18807 @item @code{socket-group} (default: @code{php-fpm})
18808 Group that can speak to the php-fpm socket.
18809 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
18810 The process id of the php-fpm process is written to this file
18811 once the service has started.
18812 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
18813 Log for the php-fpm master process.
18814 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
18815 Detailed settings for the php-fpm process manager.
18818 @item @code{<php-fpm-dynamic-process-manager-configuration>}
18819 @item @code{<php-fpm-static-process-manager-configuration>}
18820 @item @code{<php-fpm-on-demand-process-manager-configuration>}
18822 @item @code{display-errors} (default @code{#f})
18823 Determines whether php errors and warning should be sent to clients
18824 and displayed in their browsers.
18825 This is useful for local php development, but a security risk for public sites,
18826 as error messages can reveal passwords and personal data.
18827 @item @code{timezone} (default @code{#f})
18828 Specifies @code{php_admin_value[date.timezone]} parameter.
18829 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
18830 This file will log the @code{stderr} outputs of php worker processes.
18831 Can be set to @code{#f} to disable logging.
18832 @item @code{file} (default @code{#f})
18833 An optional override of the whole configuration.
18834 You can use the @code{mixed-text-file} function or an absolute filepath for it.
18838 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
18839 Data Type for the @code{dynamic} php-fpm process manager. With the
18840 @code{dynamic} process manager, spare worker processes are kept around
18841 based on it's configured limits.
18843 @item @code{max-children} (default: @code{5})
18844 Maximum of worker processes.
18845 @item @code{start-servers} (default: @code{2})
18846 How many worker processes should be started on start-up.
18847 @item @code{min-spare-servers} (default: @code{1})
18848 How many spare worker processes should be kept around at minimum.
18849 @item @code{max-spare-servers} (default: @code{3})
18850 How many spare worker processes should be kept around at maximum.
18854 @deftp {Data type} php-fpm-static-process-manager-configuration
18855 Data Type for the @code{static} php-fpm process manager. With the
18856 @code{static} process manager, an unchanging number of worker processes
18859 @item @code{max-children} (default: @code{5})
18860 Maximum of worker processes.
18864 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
18865 Data Type for the @code{on-demand} php-fpm process manager. With the
18866 @code{on-demand} process manager, worker processes are only created as
18869 @item @code{max-children} (default: @code{5})
18870 Maximum of worker processes.
18871 @item @code{process-idle-timeout} (default: @code{10})
18872 The time in seconds after which a process with no requests is killed.
18877 @deffn {Scheme Procedure} nginx-php-fpm-location @
18878 [#:nginx-package nginx] @
18879 [socket (string-append "/var/run/php" @
18880 (version-major (package-version php)) @
18882 A helper function to quickly add php to an @code{nginx-server-configuration}.
18885 A simple services setup for nginx with php can look like this:
18887 (services (cons* (service dhcp-client-service-type)
18888 (service php-fpm-service-type)
18889 (service nginx-service-type
18890 (nginx-server-configuration
18891 (server-name '("example.com"))
18892 (root "/srv/http/")
18894 (list (nginx-php-location)))
18896 (ssl-certificate #f)
18897 (ssl-certificate-key #f)))
18901 @cindex cat-avatar-generator
18902 The cat avatar generator is a simple service to demonstrate the use of php-fpm
18903 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
18904 the hash of a user's email address.
18906 @deffn {Scheme Procedure} cat-avatar-generator-service @
18907 [#:cache-dir "/var/cache/cat-avatar-generator"] @
18908 [#:package cat-avatar-generator] @
18909 [#:configuration (nginx-server-configuration)]
18910 Returns an nginx-server-configuration that inherits @code{configuration}. It
18911 extends the nginx configuration to add a server block that serves @code{package},
18912 a version of cat-avatar-generator. During execution, cat-avatar-generator will
18913 be able to use @code{cache-dir} as its cache directory.
18916 A simple setup for cat-avatar-generator can look like this:
18918 (services (cons* (cat-avatar-generator-service
18920 (nginx-server-configuration
18921 (server-name '("example.com"))))
18926 @subsubheading Hpcguix-web
18928 @cindex hpcguix-web
18929 The @uref{hpcguix-web, https://github.com/UMCUGenetics/hpcguix-web/}
18930 program is a customizable web interface to browse Guix packages,
18931 initially designed for users of high-performance computing (HPC)
18934 @defvr {Scheme Variable} hpcguix-web-service-type
18935 The service type for @code{hpcguix-web}.
18938 @deftp {Data Type} hpcguix-web-configuration
18939 Data type for the hpcguix-web service configuration.
18943 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
18944 configuration. The main items available in this spec are:
18947 @item @code{title-prefix} (default: @code{"hpcguix | "})
18948 The page title prefix.
18950 @item @code{guix-command} (default: @code{"guix"})
18951 The @command{guix} command.
18953 @item @code{package-filter-proc} (default: @code{(const #t)})
18954 A procedure specifying how to filter packages that are displayed.
18956 @item @code{package-page-extension-proc} (default: @code{(const '())})
18957 Extension package for @code{hpcguix-web}.
18959 @item @code{menu} (default: @code{'()})
18960 Additional entry in page @code{menu}.
18962 @item @code{channels} (default: @code{%default-channels})
18963 List of channels from which the package list is built (@pxref{Channels}).
18965 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
18966 The expiration time, in seconds, after which the package list is rebuilt from
18967 the latest instances of the given channels.
18970 See the hpcguix-web repository for a
18971 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
18974 @item @code{package} (default: @code{hpcguix-web})
18975 The hpcguix-web package to use.
18979 A typical hpcguix-web service declaration looks like this:
18982 (service hpcguix-web-service-type
18983 (hpcguix-web-configuration
18985 #~(define site-config
18986 (hpcweb-configuration
18987 (title-prefix "Guix-HPC - ")
18988 (menu '(("/about" "ABOUT"))))))))
18992 The hpcguix-web service periodically updates the package list it publishes by
18993 pulling channels from Git. To that end, it needs to access X.509 certificates
18994 so that it can authenticate Git servers when communicating over HTTPS, and it
18995 assumes that @file{/etc/ssl/certs} contains those certificates.
18997 Thus, make sure to add @code{nss-certs} or another certificate package to the
18998 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
18999 more information on X.509 certificates.
19002 @node Certificate Services
19003 @subsection Certificate Services
19006 @cindex HTTP, HTTPS
19007 @cindex Let's Encrypt
19008 @cindex TLS certificates
19009 The @code{(gnu services certbot)} module provides a service to
19010 automatically obtain a valid TLS certificate from the Let's Encrypt
19011 certificate authority. These certificates can then be used to serve
19012 content securely over HTTPS or other TLS-based protocols, with the
19013 knowledge that the client will be able to verify the server's
19016 @url{https://letsencrypt.org/, Let's Encrypt} provides the
19017 @code{certbot} tool to automate the certification process. This tool
19018 first securely generates a key on the server. It then makes a request
19019 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
19020 checks that the request originates from the host in question by using a
19021 challenge-response protocol, requiring the server to provide its
19022 response over HTTP. If that protocol completes successfully, the CA
19023 signs the key, resulting in a certificate. That certificate is valid
19024 for a limited period of time, and therefore to continue to provide TLS
19025 services, the server needs to periodically ask the CA to renew its
19028 The certbot service automates this process: the initial key
19029 generation, the initial certification request to the Let's Encrypt
19030 service, the web server challenge/response integration, writing the
19031 certificate to disk, the automated periodic renewals, and the deployment
19032 tasks associated with the renewal (e.g.@: reloading services, copying keys
19033 with different permissions).
19035 Certbot is run twice a day, at a random minute within the hour. It
19036 won't do anything until your certificates are due for renewal or
19037 revoked, but running it regularly would give your service a chance of
19038 staying online in case a Let's Encrypt-initiated revocation happened for
19041 By using this service, you agree to the ACME Subscriber Agreement, which
19042 can be found there:
19043 @url{https://acme-v01.api.letsencrypt.org/directory}.
19045 @defvr {Scheme Variable} certbot-service-type
19046 A service type for the @code{certbot} Let's Encrypt client. Its value
19047 must be a @code{certbot-configuration} record as in this example:
19050 (define %nginx-deploy-hook
19052 "nginx-deploy-hook"
19053 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
19054 (kill pid SIGHUP))))
19056 (service certbot-service-type
19057 (certbot-configuration
19058 (email "foo@@example.net")
19061 (certificate-configuration
19062 (domains '("example.net" "www.example.net"))
19063 (deploy-hook %nginx-deploy-hook))
19064 (certificate-configuration
19065 (domains '("bar.example.net")))))))
19068 See below for details about @code{certbot-configuration}.
19071 @deftp {Data Type} certbot-configuration
19072 Data type representing the configuration of the @code{certbot} service.
19073 This type has the following parameters:
19076 @item @code{package} (default: @code{certbot})
19077 The certbot package to use.
19079 @item @code{webroot} (default: @code{/var/www})
19080 The directory from which to serve the Let's Encrypt challenge/response
19083 @item @code{certificates} (default: @code{()})
19084 A list of @code{certificates-configuration}s for which to generate
19085 certificates and request signatures. Each certificate has a @code{name}
19086 and several @code{domains}.
19089 Mandatory email used for registration, recovery contact, and important
19090 account notifications.
19092 @item @code{rsa-key-size} (default: @code{2048})
19093 Size of the RSA key.
19095 @item @code{default-location} (default: @i{see below})
19096 The default @code{nginx-location-configuration}. Because @code{certbot}
19097 needs to be able to serve challenges and responses, it needs to be able
19098 to run a web server. It does so by extending the @code{nginx} web
19099 service with an @code{nginx-server-configuration} listening on the
19100 @var{domains} on port 80, and which has a
19101 @code{nginx-location-configuration} for the @code{/.well-known/} URI
19102 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
19103 these nginx configuration data types.
19105 Requests to other URL paths will be matched by the
19106 @code{default-location}, which if present is added to all
19107 @code{nginx-server-configuration}s.
19109 By default, the @code{default-location} will issue a redirect from
19110 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
19111 you to define what to serve on your site via @code{https}.
19113 Pass @code{#f} to not issue a default location.
19117 @deftp {Data Type} certificate-configuration
19118 Data type representing the configuration of a certificate.
19119 This type has the following parameters:
19122 @item @code{name} (default: @i{see below})
19123 This name is used by Certbot for housekeeping and in file paths; it
19124 doesn't affect the content of the certificate itself. To see
19125 certificate names, run @code{certbot certificates}.
19127 Its default is the first provided domain.
19129 @item @code{domains} (default: @code{()})
19130 The first domain provided will be the subject CN of the certificate, and
19131 all domains will be Subject Alternative Names on the certificate.
19133 @item @code{deploy-hook} (default: @code{#f})
19134 Command to be run in a shell once for each successfully issued
19135 certificate. For this command, the shell variable
19136 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
19137 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
19138 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
19139 contain a space-delimited list of renewed certificate domains (for
19140 example, @samp{"example.com www.example.com"}.
19145 For each @code{certificate-configuration}, the certificate is saved to
19146 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
19147 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
19149 @subsection DNS Services
19150 @cindex DNS (domain name system)
19151 @cindex domain name system (DNS)
19153 The @code{(gnu services dns)} module provides services related to the
19154 @dfn{domain name system} (DNS). It provides a server service for hosting
19155 an @emph{authoritative} DNS server for multiple zones, slave or master.
19156 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
19157 caching and forwarding DNS server for the LAN, which uses
19158 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
19160 @subsubheading Knot Service
19162 An example configuration of an authoritative server for two zones, one master
19166 (define-zone-entries example.org.zone
19167 ;; Name TTL Class Type Data
19168 ("@@" "" "IN" "A" "127.0.0.1")
19169 ("@@" "" "IN" "NS" "ns")
19170 ("ns" "" "IN" "A" "127.0.0.1"))
19172 (define master-zone
19173 (knot-zone-configuration
19174 (domain "example.org")
19176 (origin "example.org")
19177 (entries example.org.zone)))))
19180 (knot-zone-configuration
19181 (domain "plop.org")
19182 (dnssec-policy "default")
19183 (master (list "plop-master"))))
19185 (define plop-master
19186 (knot-remote-configuration
19188 (address (list "208.76.58.171"))))
19192 (services (cons* (service knot-service-type
19193 (knot-configuration
19194 (remotes (list plop-master))
19195 (zones (list master-zone slave-zone))))
19200 @deffn {Scheme Variable} knot-service-type
19201 This is the type for the Knot DNS server.
19203 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
19204 zones, that is to say domain names you would buy from a registrar. This server
19205 is not a resolver, meaning that it can only resolve names for which it is
19206 authoritative. This server can be configured to serve zones as a master server
19207 or a slave server as a per-zone basis. Slave zones will get their data from
19208 masters, and will serve it as an authoritative server. From the point of view
19209 of a resolver, there is no difference between master and slave.
19211 The following data types are used to configure the Knot DNS server:
19214 @deftp {Data Type} knot-key-configuration
19215 Data type representing a key.
19216 This type has the following parameters:
19219 @item @code{id} (default: @code{""})
19220 An identifier for other configuration fields to refer to this key. IDs must
19221 be unique and must not be empty.
19223 @item @code{algorithm} (default: @code{#f})
19224 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
19225 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
19226 and @code{'hmac-sha512}.
19228 @item @code{secret} (default: @code{""})
19229 The secret key itself.
19234 @deftp {Data Type} knot-acl-configuration
19235 Data type representing an Access Control List (ACL) configuration.
19236 This type has the following parameters:
19239 @item @code{id} (default: @code{""})
19240 An identifier for ether configuration fields to refer to this key. IDs must be
19241 unique and must not be empty.
19243 @item @code{address} (default: @code{'()})
19244 An ordered list of IP addresses, network subnets, or network ranges represented
19245 with strings. The query must match one of them. Empty value means that
19246 address match is not required.
19248 @item @code{key} (default: @code{'()})
19249 An ordered list of references to keys represented with strings. The string
19250 must match a key ID defined in a @code{knot-key-configuration}. No key means
19251 that a key is not require to match that ACL.
19253 @item @code{action} (default: @code{'()})
19254 An ordered list of actions that are permitted or forbidden by this ACL. Possible
19255 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
19256 and @code{'update}.
19258 @item @code{deny?} (default: @code{#f})
19259 When true, the ACL defines restrictions. Listed actions are forbidden. When
19260 false, listed actions are allowed.
19265 @deftp {Data Type} zone-entry
19266 Data type represnting a record entry in a zone file.
19267 This type has the following parameters:
19270 @item @code{name} (default: @code{"@@"})
19271 The name of the record. @code{"@@"} refers to the origin of the zone. Names
19272 are relative to the origin of the zone. For example, in the @code{example.org}
19273 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
19274 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
19275 refers to @code{ns.example.org}.
19277 @item @code{ttl} (default: @code{""})
19278 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
19280 @item @code{class} (default: @code{"IN"})
19281 The class of the record. Knot currently supports only @code{"IN"} and
19282 partially @code{"CH"}.
19284 @item @code{type} (default: @code{"A"})
19285 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
19286 address), NS (Name Server) and MX (Mail eXchange). Many other types are
19289 @item @code{data} (default: @code{""})
19290 The data contained in the record. For instance an IP address associated with
19291 an A record, or a domain name associated with an NS record. Remember that
19292 domain names are relative to the origin unless they end with a dot.
19297 @deftp {Data Type} zone-file
19298 Data type representing the content of a zone file.
19299 This type has the following parameters:
19302 @item @code{entries} (default: @code{'()})
19303 The list of entries. The SOA record is taken care of, so you don't need to
19304 put it in the list of entries. This list should probably contain an entry
19305 for your primary authoritative DNS server. Other than using a list of entries
19306 directly, you can use @code{define-zone-entries} to define a object containing
19307 the list of entries more easily, that you can later pass to the @code{entries}
19308 field of the @code{zone-file}.
19310 @item @code{origin} (default: @code{""})
19311 The name of your zone. This parameter cannot be empty.
19313 @item @code{ns} (default: @code{"ns"})
19314 The domain of your primary authoritative DNS server. The name is relative to
19315 the origin, unless it ends with a dot. It is mandatory that this primary
19316 DNS server corresponds to an NS record in the zone and that it is associated
19317 to an IP address in the list of entries.
19319 @item @code{mail} (default: @code{"hostmaster"})
19320 An email address people can contact you at, as the owner of the zone. This
19321 is translated as @code{<mail>@@<origin>}.
19323 @item @code{serial} (default: @code{1})
19324 The serial number of the zone. As this is used to keep track of changes by
19325 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
19326 Always increment it when you make a change in your zone.
19328 @item @code{refresh} (default: @code{(* 2 24 3600)})
19329 The frequency at which slaves will do a zone transfer. This value is a number
19330 of seconds. It can be computed by multiplications or with
19331 @code{(string->duration)}.
19333 @item @code{retry} (default: @code{(* 15 60)})
19334 The period after which a slave will retry to contact its master when it fails
19335 to do so a first time.
19337 @item @code{expiry} (default: @code{(* 14 24 3600)})
19338 Default TTL of records. Existing records are considered correct for at most
19339 this amount of time. After this period, resolvers will invalidate their cache
19340 and check again that it still exists.
19342 @item @code{nx} (default: @code{3600})
19343 Default TTL of inexistant records. This delay is usually short because you want
19344 your new domains to reach everyone quickly.
19349 @deftp {Data Type} knot-remote-configuration
19350 Data type representing a remote configuration.
19351 This type has the following parameters:
19354 @item @code{id} (default: @code{""})
19355 An identifier for other configuration fields to refer to this remote. IDs must
19356 be unique and must not be empty.
19358 @item @code{address} (default: @code{'()})
19359 An ordered list of destination IP addresses. Addresses are tried in sequence.
19360 An optional port can be given with the @@ separator. For instance:
19361 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
19363 @item @code{via} (default: @code{'()})
19364 An ordered list of source IP addresses. An empty list will have Knot choose
19365 an appropriate source IP. An optional port can be given with the @@ separator.
19366 The default is to choose at random.
19368 @item @code{key} (default: @code{#f})
19369 A reference to a key, that is a string containing the identifier of a key
19370 defined in a @code{knot-key-configuration} field.
19375 @deftp {Data Type} knot-keystore-configuration
19376 Data type representing a keystore to hold dnssec keys.
19377 This type has the following parameters:
19380 @item @code{id} (default: @code{""})
19381 The id of the keystore. It must not be empty.
19383 @item @code{backend} (default: @code{'pem})
19384 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
19386 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
19387 The configuration string of the backend. An example for the PKCS#11 is:
19388 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
19389 For the pem backend, the string reprensents a path in the file system.
19394 @deftp {Data Type} knot-policy-configuration
19395 Data type representing a dnssec policy. Knot DNS is able to automatically
19396 sign your zones. It can either generate and manage your keys automatically or
19397 use keys that you generate.
19399 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
19400 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
19401 zone. In order to be trusted, the KSK needs to be present in the parent zone
19402 (usually a top-level domain). If your registrar supports dnssec, you will
19403 have to send them your KSK's hash so they can add a DS record in their zone.
19404 This is not automated and need to be done each time you change your KSK.
19406 The policy also defines the lifetime of keys. Usually, ZSK can be changed
19407 easily and use weaker cryptographic functions (they use lower parameters) in
19408 order to sign records quickly, so they are changed often. The KSK however
19409 requires manual interaction with the registrar, so they are changed less often
19410 and use stronger parameters because they sign only one record.
19412 This type has the following parameters:
19415 @item @code{id} (default: @code{""})
19416 The id of the policy. It must not be empty.
19418 @item @code{keystore} (default: @code{"default"})
19419 A reference to a keystore, that is a string containing the identifier of a
19420 keystore defined in a @code{knot-keystore-configuration} field. The
19421 @code{"default"} identifier means the default keystore (a kasp database that
19422 was setup by this service).
19424 @item @code{manual?} (default: @code{#f})
19425 Whether the key management is manual or automatic.
19427 @item @code{single-type-signing?} (default: @code{#f})
19428 When @code{#t}, use the Single-Type Signing Scheme.
19430 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
19431 An algorithm of signing keys and issued signatures.
19433 @item @code{ksk-size} (default: @code{256})
19434 The length of the KSK. Note that this value is correct for the default
19435 algorithm, but would be unsecure for other algorithms.
19437 @item @code{zsk-size} (default: @code{256})
19438 The length of the ZSK. Note that this value is correct for the default
19439 algorithm, but would be unsecure for other algorithms.
19441 @item @code{dnskey-ttl} (default: @code{'default})
19442 The TTL value for DNSKEY records added into zone apex. The special
19443 @code{'default} value means same as the zone SOA TTL.
19445 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
19446 The period between ZSK publication and the next rollover initiation.
19448 @item @code{propagation-delay} (default: @code{(* 24 3600)})
19449 An extra delay added for each key rollover step. This value should be high
19450 enough to cover propagation of data from the master server to all slaves.
19452 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
19453 A validity period of newly issued signatures.
19455 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
19456 A period how long before a signature expiration the signature will be refreshed.
19458 @item @code{nsec3?} (default: @code{#f})
19459 When @code{#t}, NSEC3 will be used instead of NSEC.
19461 @item @code{nsec3-iterations} (default: @code{5})
19462 The number of additional times the hashing is performed.
19464 @item @code{nsec3-salt-length} (default: @code{8})
19465 The length of a salt field in octets, which is appended to the original owner
19466 name before hashing.
19468 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
19469 The validity period of newly issued salt field.
19474 @deftp {Data Type} knot-zone-configuration
19475 Data type representing a zone served by Knot.
19476 This type has the following parameters:
19479 @item @code{domain} (default: @code{""})
19480 The domain served by this configuration. It must not be empty.
19482 @item @code{file} (default: @code{""})
19483 The file where this zone is saved. This parameter is ignored by master zones.
19484 Empty means default location that depends on the domain name.
19486 @item @code{zone} (default: @code{(zone-file)})
19487 The content of the zone file. This parameter is ignored by slave zones. It
19488 must contain a zone-file record.
19490 @item @code{master} (default: @code{'()})
19491 A list of master remotes. When empty, this zone is a master. When set, this
19492 zone is a slave. This is a list of remotes identifiers.
19494 @item @code{ddns-master} (default: @code{#f})
19495 The main master. When empty, it defaults to the first master in the list of
19498 @item @code{notify} (default: @code{'()})
19499 A list of slave remote identifiers.
19501 @item @code{acl} (default: @code{'()})
19502 A list of acl identifiers.
19504 @item @code{semantic-checks?} (default: @code{#f})
19505 When set, this adds more semantic checks to the zone.
19507 @item @code{disable-any?} (default: @code{#f})
19508 When set, this forbids queries of the ANY type.
19510 @item @code{zonefile-sync} (default: @code{0})
19511 The delay between a modification in memory and on disk. 0 means immediate
19514 @item @code{serial-policy} (default: @code{'increment})
19515 A policy between @code{'increment} and @code{'unixtime}.
19520 @deftp {Data Type} knot-configuration
19521 Data type representing the Knot configuration.
19522 This type has the following parameters:
19525 @item @code{knot} (default: @code{knot})
19528 @item @code{run-directory} (default: @code{"/var/run/knot"})
19529 The run directory. This directory will be used for pid file and sockets.
19531 @item @code{listen-v4} (default: @code{"0.0.0.0"})
19532 An ip address on which to listen.
19534 @item @code{listen-v6} (default: @code{"::"})
19535 An ip address on which to listen.
19537 @item @code{listen-port} (default: @code{53})
19538 A port on which to listen.
19540 @item @code{keys} (default: @code{'()})
19541 The list of knot-key-configuration used by this configuration.
19543 @item @code{acls} (default: @code{'()})
19544 The list of knot-acl-configuration used by this configuration.
19546 @item @code{remotes} (default: @code{'()})
19547 The list of knot-remote-configuration used by this configuration.
19549 @item @code{zones} (default: @code{'()})
19550 The list of knot-zone-configuration used by this configuration.
19555 @subsubheading Dnsmasq Service
19557 @deffn {Scheme Variable} dnsmasq-service-type
19558 This is the type of the dnsmasq service, whose value should be an
19559 @code{dnsmasq-configuration} object as in this example:
19562 (service dnsmasq-service-type
19563 (dnsmasq-configuration
19565 (servers '("192.168.1.1"))))
19569 @deftp {Data Type} dnsmasq-configuration
19570 Data type representing the configuration of dnsmasq.
19573 @item @code{package} (default: @var{dnsmasq})
19574 Package object of the dnsmasq server.
19576 @item @code{no-hosts?} (default: @code{#f})
19577 When true, don't read the hostnames in /etc/hosts.
19579 @item @code{port} (default: @code{53})
19580 The port to listen on. Setting this to zero completely disables DNS
19581 responses, leaving only DHCP and/or TFTP functions.
19583 @item @code{local-service?} (default: @code{#t})
19584 Accept DNS queries only from hosts whose address is on a local subnet,
19585 ie a subnet for which an interface exists on the server.
19587 @item @code{listen-addresses} (default: @code{'()})
19588 Listen on the given IP addresses.
19590 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
19591 The file to read the IP address of the upstream nameservers from.
19593 @item @code{no-resolv?} (default: @code{#f})
19594 When true, don't read @var{resolv-file}.
19596 @item @code{servers} (default: @code{'()})
19597 Specify IP address of upstream servers directly.
19599 @item @code{cache-size} (default: @code{150})
19600 Set the size of dnsmasq's cache. Setting the cache size to zero
19603 @item @code{negative-cache?} (default: @code{#t})
19604 When false, disable negative caching.
19609 @subsubheading ddclient Service
19612 The ddclient service described below runs the ddclient daemon, which takes
19613 care of automatically updating DNS entries for service providers such as
19614 @uref{https://dyn.com/dns/, Dyn}.
19616 The following example show instantiates the service with its default
19620 (service ddclient-service-type)
19623 Note that ddclient needs to access credentials that are stored in a
19624 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
19625 @code{secret-file} below.) You are expected to create this file manually, in
19626 an ``out-of-band'' fashion (you @emph{could} make this file part of the
19627 service configuration, for instance by using @code{plain-file}, but it will be
19628 world-readable @i{via} @file{/gnu/store}.) See the examples in the
19629 @file{share/ddclient} directory of the @code{ddclient} package.
19631 @c %start of fragment
19633 Available @code{ddclient-configuration} fields are:
19635 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
19636 The ddclient package.
19640 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
19641 The period after which ddclient will retry to check IP and domain name.
19643 Defaults to @samp{300}.
19647 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
19648 Use syslog for the output.
19650 Defaults to @samp{#t}.
19654 @deftypevr {@code{ddclient-configuration} parameter} string mail
19657 Defaults to @samp{"root"}.
19661 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
19662 Mail failed update to user.
19664 Defaults to @samp{"root"}.
19668 @deftypevr {@code{ddclient-configuration} parameter} string pid
19669 The ddclient PID file.
19671 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
19675 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
19676 Enable SSL support.
19678 Defaults to @samp{#t}.
19682 @deftypevr {@code{ddclient-configuration} parameter} string user
19683 Specifies the user name or ID that is used when running ddclient
19686 Defaults to @samp{"ddclient"}.
19690 @deftypevr {@code{ddclient-configuration} parameter} string group
19691 Group of the user who will run the ddclient program.
19693 Defaults to @samp{"ddclient"}.
19697 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
19698 Secret file which will be appended to @file{ddclient.conf} file. This
19699 file contains credentials for use by ddclient. You are expected to
19700 create it manually.
19702 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
19706 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
19707 Extra options will be appended to @file{ddclient.conf} file.
19709 Defaults to @samp{()}.
19714 @c %end of fragment
19718 @subsection VPN Services
19719 @cindex VPN (virtual private network)
19720 @cindex virtual private network (VPN)
19722 The @code{(gnu services vpn)} module provides services related to
19723 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
19724 your machine to connect to a VPN, and a @emph{servire} service for your machine
19725 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
19727 @deffn {Scheme Procedure} openvpn-client-service @
19728 [#:config (openvpn-client-configuration)]
19730 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
19733 @deffn {Scheme Procedure} openvpn-server-service @
19734 [#:config (openvpn-server-configuration)]
19736 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
19738 Both can be run simultaneously.
19741 @c %automatically generated documentation
19743 Available @code{openvpn-client-configuration} fields are:
19745 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
19746 The OpenVPN package.
19750 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
19751 The OpenVPN pid file.
19753 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
19757 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
19758 The protocol (UDP or TCP) used to open a channel between clients and
19761 Defaults to @samp{udp}.
19765 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
19766 The device type used to represent the VPN connection.
19768 Defaults to @samp{tun}.
19772 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
19773 The certificate authority to check connections against.
19775 Defaults to @samp{"/etc/openvpn/ca.crt"}.
19779 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
19780 The certificate of the machine the daemon is running on. It should be
19781 signed by the authority given in @code{ca}.
19783 Defaults to @samp{"/etc/openvpn/client.crt"}.
19787 @deftypevr {@code{openvpn-client-configuration} parameter} string key
19788 The key of the machine the daemon is running on. It must be the key whose
19789 certificate is @code{cert}.
19791 Defaults to @samp{"/etc/openvpn/client.key"}.
19795 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
19796 Whether to use the lzo compression algorithm.
19798 Defaults to @samp{#t}.
19802 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
19803 Don't re-read key files across SIGUSR1 or --ping-restart.
19805 Defaults to @samp{#t}.
19809 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
19810 Don't close and reopen TUN/TAP device or run up/down scripts across
19811 SIGUSR1 or --ping-restart restarts.
19813 Defaults to @samp{#t}.
19817 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
19820 Defaults to @samp{3}.
19824 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
19825 Add an additional layer of HMAC authentication on top of the TLS control
19826 channel to protect against DoS attacks.
19828 Defaults to @samp{#f}.
19832 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
19833 Whether to check the server certificate has server usage extension.
19835 Defaults to @samp{#t}.
19839 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
19840 Bind to a specific local port number.
19842 Defaults to @samp{#f}.
19846 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
19847 Retry resolving server address.
19849 Defaults to @samp{#t}.
19853 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
19854 A list of remote servers to connect to.
19856 Defaults to @samp{()}.
19858 Available @code{openvpn-remote-configuration} fields are:
19860 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
19863 Defaults to @samp{"my-server"}.
19867 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
19868 Port number the server listens to.
19870 Defaults to @samp{1194}.
19875 @c %end of automatic openvpn-client documentation
19877 @c %automatically generated documentation
19879 Available @code{openvpn-server-configuration} fields are:
19881 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
19882 The OpenVPN package.
19886 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
19887 The OpenVPN pid file.
19889 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
19893 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
19894 The protocol (UDP or TCP) used to open a channel between clients and
19897 Defaults to @samp{udp}.
19901 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
19902 The device type used to represent the VPN connection.
19904 Defaults to @samp{tun}.
19908 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
19909 The certificate authority to check connections against.
19911 Defaults to @samp{"/etc/openvpn/ca.crt"}.
19915 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
19916 The certificate of the machine the daemon is running on. It should be
19917 signed by the authority given in @code{ca}.
19919 Defaults to @samp{"/etc/openvpn/client.crt"}.
19923 @deftypevr {@code{openvpn-server-configuration} parameter} string key
19924 The key of the machine the daemon is running on. It must be the key whose
19925 certificate is @code{cert}.
19927 Defaults to @samp{"/etc/openvpn/client.key"}.
19931 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
19932 Whether to use the lzo compression algorithm.
19934 Defaults to @samp{#t}.
19938 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
19939 Don't re-read key files across SIGUSR1 or --ping-restart.
19941 Defaults to @samp{#t}.
19945 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
19946 Don't close and reopen TUN/TAP device or run up/down scripts across
19947 SIGUSR1 or --ping-restart restarts.
19949 Defaults to @samp{#t}.
19953 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
19956 Defaults to @samp{3}.
19960 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
19961 Add an additional layer of HMAC authentication on top of the TLS control
19962 channel to protect against DoS attacks.
19964 Defaults to @samp{#f}.
19968 @deftypevr {@code{openvpn-server-configuration} parameter} number port
19969 Specifies the port number on which the server listens.
19971 Defaults to @samp{1194}.
19975 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
19976 An ip and mask specifying the subnet inside the virtual network.
19978 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
19982 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
19983 A CIDR notation specifying the IPv6 subnet inside the virtual network.
19985 Defaults to @samp{#f}.
19989 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
19990 The Diffie-Hellman parameters file.
19992 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
19996 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
19997 The file that records client IPs.
19999 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
20003 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
20004 When true, the server will act as a gateway for its clients.
20006 Defaults to @samp{#f}.
20010 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
20011 When true, clients are allowed to talk to each other inside the VPN.
20013 Defaults to @samp{#f}.
20017 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
20018 Causes ping-like messages to be sent back and forth over the link so
20019 that each side knows when the other side has gone down. @code{keepalive}
20020 requires a pair. The first element is the period of the ping sending,
20021 and the second element is the timeout before considering the other side
20026 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
20027 The maximum number of clients.
20029 Defaults to @samp{100}.
20033 @deftypevr {@code{openvpn-server-configuration} parameter} string status
20034 The status file. This file shows a small report on current connection.
20035 It is truncated and rewritten every minute.
20037 Defaults to @samp{"/var/run/openvpn/status"}.
20041 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
20042 The list of configuration for some clients.
20044 Defaults to @samp{()}.
20046 Available @code{openvpn-ccd-configuration} fields are:
20048 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
20051 Defaults to @samp{"client"}.
20055 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
20058 Defaults to @samp{#f}.
20062 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
20065 Defaults to @samp{#f}.
20072 @c %end of automatic openvpn-server documentation
20075 @node Network File System
20076 @subsection Network File System
20079 The @code{(gnu services nfs)} module provides the following services,
20080 which are most commonly used in relation to mounting or exporting
20081 directory trees as @dfn{network file systems} (NFS).
20083 @subsubheading RPC Bind Service
20086 The RPC Bind service provides a facility to map program numbers into
20087 universal addresses.
20088 Many NFS related services use this facility. Hence it is automatically
20089 started when a dependent service starts.
20091 @defvr {Scheme Variable} rpcbind-service-type
20092 A service type for the RPC portmapper daemon.
20096 @deftp {Data Type} rpcbind-configuration
20097 Data type representing the configuration of the RPC Bind Service.
20098 This type has the following parameters:
20100 @item @code{rpcbind} (default: @code{rpcbind})
20101 The rpcbind package to use.
20103 @item @code{warm-start?} (default: @code{#t})
20104 If this parameter is @code{#t}, then the daemon will read a
20105 state file on startup thus reloading state information saved by a previous
20111 @subsubheading Pipefs Pseudo File System
20115 The pipefs file system is used to transfer NFS related data
20116 between the kernel and user space programs.
20118 @defvr {Scheme Variable} pipefs-service-type
20119 A service type for the pipefs pseudo file system.
20122 @deftp {Data Type} pipefs-configuration
20123 Data type representing the configuration of the pipefs pseudo file system service.
20124 This type has the following parameters:
20126 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20127 The directory to which the file system is to be attached.
20132 @subsubheading GSS Daemon Service
20135 @cindex global security system
20137 The @dfn{global security system} (GSS) daemon provides strong security for RPC
20139 Before exchanging RPC requests an RPC client must establish a security
20140 context. Typically this is done using the Kerberos command @command{kinit}
20141 or automatically at login time using PAM services (@pxref{Kerberos Services}).
20143 @defvr {Scheme Variable} gss-service-type
20144 A service type for the Global Security System (GSS) daemon.
20147 @deftp {Data Type} gss-configuration
20148 Data type representing the configuration of the GSS daemon service.
20149 This type has the following parameters:
20151 @item @code{nfs-utils} (default: @code{nfs-utils})
20152 The package in which the @command{rpc.gssd} command is to be found.
20154 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20155 The directory where the pipefs file system is mounted.
20161 @subsubheading IDMAP Daemon Service
20163 @cindex name mapper
20165 The idmap daemon service provides mapping between user IDs and user names.
20166 Typically it is required in order to access file systems mounted via NFSv4.
20168 @defvr {Scheme Variable} idmap-service-type
20169 A service type for the Identity Mapper (IDMAP) daemon.
20172 @deftp {Data Type} idmap-configuration
20173 Data type representing the configuration of the IDMAP daemon service.
20174 This type has the following parameters:
20176 @item @code{nfs-utils} (default: @code{nfs-utils})
20177 The package in which the @command{rpc.idmapd} command is to be found.
20179 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20180 The directory where the pipefs file system is mounted.
20182 @item @code{domain} (default: @code{#f})
20183 The local NFSv4 domain name.
20184 This must be a string or @code{#f}.
20185 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
20190 @node Continuous Integration
20191 @subsection Continuous Integration
20193 @cindex continuous integration
20194 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
20195 continuous integration tool for Guix. It can be used both for development and
20196 for providing substitutes to others (@pxref{Substitutes}).
20198 The @code{(gnu services cuirass)} module provides the following service.
20200 @defvr {Scheme Procedure} cuirass-service-type
20201 The type of the Cuirass service. Its value must be a
20202 @code{cuirass-configuration} object, as described below.
20205 To add build jobs, you have to set the @code{specifications} field of the
20206 configuration. Here is an example of a service that polls the Guix repository
20207 and builds the packages from a manifest. Some of the packages are defined in
20208 the @code{"custom-packages"} input, which is the equivalent of
20209 @code{GUIX_PACKAGE_PATH}.
20212 (define %cuirass-specs
20214 '((#:name . "my-manifest")
20215 (#:load-path-inputs . ("guix"))
20216 (#:package-path-inputs . ("custom-packages"))
20217 (#:proc-input . "guix")
20218 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
20219 (#:proc . cuirass-jobs)
20220 (#:proc-args . ((subset . "manifests")
20221 (systems . ("x86_64-linux"))
20222 (manifests . (("config" . "guix/manifest.scm")))))
20223 (#:inputs . (((#:name . "guix")
20224 (#:url . "git://git.savannah.gnu.org/guix.git")
20225 (#:load-path . ".")
20226 (#:branch . "master")
20227 (#:no-compile? . #t))
20228 ((#:name . "config")
20229 (#:url . "git://git.example.org/config.git")
20230 (#:load-path . ".")
20231 (#:branch . "master")
20232 (#:no-compile? . #t))
20233 ((#:name . "custom-packages")
20234 (#:url . "git://git.example.org/custom-packages.git")
20235 (#:load-path . ".")
20236 (#:branch . "master")
20237 (#:no-compile? . #t)))))))
20239 (service cuirass-service-type
20240 (cuirass-configuration
20241 (specifications %cuirass-specs)))
20244 While information related to build jobs is located directly in the
20245 specifications, global settings for the @command{cuirass} process are
20246 accessible in other @code{cuirass-configuration} fields.
20248 @deftp {Data Type} cuirass-configuration
20249 Data type representing the configuration of Cuirass.
20252 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
20253 Location of the log file.
20255 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
20256 Location of the repository cache.
20258 @item @code{user} (default: @code{"cuirass"})
20259 Owner of the @code{cuirass} process.
20261 @item @code{group} (default: @code{"cuirass"})
20262 Owner's group of the @code{cuirass} process.
20264 @item @code{interval} (default: @code{60})
20265 Number of seconds between the poll of the repositories followed by the
20268 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
20269 Location of sqlite database which contains the build results and previously
20270 added specifications.
20272 @item @code{ttl} (default: @code{(* 30 24 3600)})
20273 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
20274 are registered for build results. This means that build results are protected
20275 from garbage collection for at least @var{ttl} seconds.
20277 @item @code{port} (default: @code{8081})
20278 Port number used by the HTTP server.
20280 @item --listen=@var{host}
20281 Listen on the network interface for @var{host}. The default is to
20282 accept connections from localhost.
20284 @item @code{specifications} (default: @code{#~'()})
20285 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
20286 where a specification is an association list
20287 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
20288 keys are keywords (@code{#:keyword-example}) as shown in the example
20291 @item @code{use-substitutes?} (default: @code{#f})
20292 This allows using substitutes to avoid building every dependencies of a job
20295 @item @code{one-shot?} (default: @code{#f})
20296 Only evaluate specifications and build derivations once.
20298 @item @code{fallback?} (default: @code{#f})
20299 When substituting a pre-built binary fails, fall back to building
20302 @item @code{cuirass} (default: @code{cuirass})
20303 The Cuirass package to use.
20307 @node Power Management Services
20308 @subsection Power Management Services
20311 @cindex power management with TLP
20312 @subsubheading TLP daemon
20314 The @code{(gnu services pm)} module provides a Guix service definition
20315 for the Linux power management tool TLP.
20317 TLP enables various powersaving modes in userspace and kernel.
20318 Contrary to @code{upower-service}, it is not a passive,
20319 monitoring tool, as it will apply custom settings each time a new power
20320 source is detected. More information can be found at
20321 @uref{http://linrunner.de/en/tlp/tlp.html, TLP home page}.
20323 @deffn {Scheme Variable} tlp-service-type
20324 The service type for the TLP tool. Its value should be a valid
20325 TLP configuration (see below). To use the default settings, simply
20328 (service tlp-service-type)
20332 By default TLP does not need much configuration but most TLP parameters
20333 can be tweaked using @code{tlp-configuration}.
20335 Each parameter definition is preceded by its type; for example,
20336 @samp{boolean foo} indicates that the @code{foo} parameter
20337 should be specified as a boolean. Types starting with
20338 @code{maybe-} denote parameters that won't show up in TLP config file
20339 when their value is @code{'disabled}.
20341 @c The following documentation was initially generated by
20342 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
20343 @c documentation is better, so we shouldn't hesitate to edit below as
20344 @c needed. However if the change you want to make to this documentation
20345 @c can be done in an automated way, it's probably easier to change
20346 @c (generate-documentation) than to make it below and have to deal with
20347 @c the churn as TLP updates.
20349 Available @code{tlp-configuration} fields are:
20351 @deftypevr {@code{tlp-configuration} parameter} package tlp
20356 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
20357 Set to true if you wish to enable TLP.
20359 Defaults to @samp{#t}.
20363 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
20364 Default mode when no power supply can be detected. Alternatives are AC
20367 Defaults to @samp{"AC"}.
20371 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
20372 Number of seconds Linux kernel has to wait after the disk goes idle,
20373 before syncing on AC.
20375 Defaults to @samp{0}.
20379 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
20380 Same as @code{disk-idle-ac} but on BAT mode.
20382 Defaults to @samp{2}.
20386 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
20387 Dirty pages flushing periodicity, expressed in seconds.
20389 Defaults to @samp{15}.
20393 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
20394 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
20396 Defaults to @samp{60}.
20400 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
20401 CPU frequency scaling governor on AC mode. With intel_pstate driver,
20402 alternatives are powersave and performance. With acpi-cpufreq driver,
20403 alternatives are ondemand, powersave, performance and conservative.
20405 Defaults to @samp{disabled}.
20409 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
20410 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
20412 Defaults to @samp{disabled}.
20416 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
20417 Set the min available frequency for the scaling governor on AC.
20419 Defaults to @samp{disabled}.
20423 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
20424 Set the max available frequency for the scaling governor on AC.
20426 Defaults to @samp{disabled}.
20430 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
20431 Set the min available frequency for the scaling governor on BAT.
20433 Defaults to @samp{disabled}.
20437 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
20438 Set the max available frequency for the scaling governor on BAT.
20440 Defaults to @samp{disabled}.
20444 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
20445 Limit the min P-state to control the power dissipation of the CPU, in AC
20446 mode. Values are stated as a percentage of the available performance.
20448 Defaults to @samp{disabled}.
20452 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
20453 Limit the max P-state to control the power dissipation of the CPU, in AC
20454 mode. Values are stated as a percentage of the available performance.
20456 Defaults to @samp{disabled}.
20460 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
20461 Same as @code{cpu-min-perf-on-ac} on BAT mode.
20463 Defaults to @samp{disabled}.
20467 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
20468 Same as @code{cpu-max-perf-on-ac} on BAT mode.
20470 Defaults to @samp{disabled}.
20474 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
20475 Enable CPU turbo boost feature on AC mode.
20477 Defaults to @samp{disabled}.
20481 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
20482 Same as @code{cpu-boost-on-ac?} on BAT mode.
20484 Defaults to @samp{disabled}.
20488 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
20489 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
20490 used under light load conditions.
20492 Defaults to @samp{#f}.
20496 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
20497 Same as @code{sched-powersave-on-ac?} but on BAT mode.
20499 Defaults to @samp{#t}.
20503 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
20504 Enable Linux kernel NMI watchdog.
20506 Defaults to @samp{#f}.
20510 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
20511 For Linux kernels with PHC patch applied, change CPU voltages. An
20512 example value would be @samp{"F:V F:V F:V F:V"}.
20514 Defaults to @samp{disabled}.
20518 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
20519 Set CPU performance versus energy saving policy on AC. Alternatives are
20520 performance, normal, powersave.
20522 Defaults to @samp{"performance"}.
20526 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
20527 Same as @code{energy-perf-policy-ac} but on BAT mode.
20529 Defaults to @samp{"powersave"}.
20533 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
20538 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
20539 Hard disk advanced power management level.
20543 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
20544 Same as @code{disk-apm-bat} but on BAT mode.
20548 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
20549 Hard disk spin down timeout. One value has to be specified for each
20550 declared hard disk.
20552 Defaults to @samp{disabled}.
20556 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
20557 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
20559 Defaults to @samp{disabled}.
20563 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
20564 Select IO scheduler for disk devices. One value has to be specified for
20565 each declared hard disk. Example alternatives are cfq, deadline and
20568 Defaults to @samp{disabled}.
20572 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
20573 SATA aggressive link power management (ALPM) level. Alternatives are
20574 min_power, medium_power, max_performance.
20576 Defaults to @samp{"max_performance"}.
20580 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
20581 Same as @code{sata-linkpwr-ac} but on BAT mode.
20583 Defaults to @samp{"min_power"}.
20587 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
20588 Exclude specified SATA host devices for link power management.
20590 Defaults to @samp{disabled}.
20594 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
20595 Enable Runtime Power Management for AHCI controller and disks on AC
20598 Defaults to @samp{disabled}.
20602 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
20603 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
20605 Defaults to @samp{disabled}.
20609 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
20610 Seconds of inactivity before disk is suspended.
20612 Defaults to @samp{15}.
20616 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
20617 PCI Express Active State Power Management level. Alternatives are
20618 default, performance, powersave.
20620 Defaults to @samp{"performance"}.
20624 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
20625 Same as @code{pcie-aspm-ac} but on BAT mode.
20627 Defaults to @samp{"powersave"}.
20631 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
20632 Radeon graphics clock speed level. Alternatives are low, mid, high,
20635 Defaults to @samp{"high"}.
20639 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
20640 Same as @code{radeon-power-ac} but on BAT mode.
20642 Defaults to @samp{"low"}.
20646 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
20647 Radeon dynamic power management method (DPM). Alternatives are battery,
20650 Defaults to @samp{"performance"}.
20654 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
20655 Same as @code{radeon-dpm-state-ac} but on BAT mode.
20657 Defaults to @samp{"battery"}.
20661 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
20662 Radeon DPM performance level. Alternatives are auto, low, high.
20664 Defaults to @samp{"auto"}.
20668 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
20669 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
20671 Defaults to @samp{"auto"}.
20675 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
20676 Wifi power saving mode.
20678 Defaults to @samp{#f}.
20682 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
20683 Same as @code{wifi-power-ac?} but on BAT mode.
20685 Defaults to @samp{#t}.
20689 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
20690 Disable wake on LAN.
20692 Defaults to @samp{#t}.
20696 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
20697 Timeout duration in seconds before activating audio power saving on
20698 Intel HDA and AC97 devices. A value of 0 disables power saving.
20700 Defaults to @samp{0}.
20704 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
20705 Same as @code{sound-powersave-ac} but on BAT mode.
20707 Defaults to @samp{1}.
20711 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
20712 Disable controller in powersaving mode on Intel HDA devices.
20714 Defaults to @samp{#t}.
20718 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
20719 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
20720 powered on again by releasing (and reinserting) the eject lever or by
20721 pressing the disc eject button on newer models.
20723 Defaults to @samp{#f}.
20727 @deftypevr {@code{tlp-configuration} parameter} string bay-device
20728 Name of the optical drive device to power off.
20730 Defaults to @samp{"sr0"}.
20734 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
20735 Runtime Power Management for PCI(e) bus devices. Alternatives are on
20738 Defaults to @samp{"on"}.
20742 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
20743 Same as @code{runtime-pm-ac} but on BAT mode.
20745 Defaults to @samp{"auto"}.
20749 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
20750 Runtime Power Management for all PCI(e) bus devices, except blacklisted
20753 Defaults to @samp{#t}.
20757 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
20758 Exclude specified PCI(e) device addresses from Runtime Power Management.
20760 Defaults to @samp{disabled}.
20764 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
20765 Exclude PCI(e) devices assigned to the specified drivers from Runtime
20770 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
20771 Enable USB autosuspend feature.
20773 Defaults to @samp{#t}.
20777 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
20778 Exclude specified devices from USB autosuspend.
20780 Defaults to @samp{disabled}.
20784 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
20785 Exclude WWAN devices from USB autosuspend.
20787 Defaults to @samp{#t}.
20791 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
20792 Include specified devices into USB autosuspend, even if they are already
20793 excluded by the driver or via @code{usb-blacklist-wwan?}.
20795 Defaults to @samp{disabled}.
20799 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
20800 Enable USB autosuspend before shutdown.
20802 Defaults to @samp{disabled}.
20806 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
20807 Restore radio device state (bluetooth, wifi, wwan) from previous
20808 shutdown on system startup.
20810 Defaults to @samp{#f}.
20815 @cindex CPU frequency scaling with thermald
20816 @subsubheading Thermald daemon
20818 The @code{(gnu services pm)} module provides an interface to
20819 thermald, a CPU frequency scaling service which helps prevent overheating.
20821 @defvr {Scheme Variable} thermald-service-type
20822 This is the service type for
20823 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
20824 Thermal Daemon, which is responsible for controlling the thermal state
20825 of processors and preventing overheating.
20828 @deftp {Data Type} thermald-configuration
20829 Data type representing the configuration of @code{thermald-service-type}.
20832 @item @code{ignore-cpuid-check?} (default: @code{#f})
20833 Ignore cpuid check for supported CPU models.
20835 @item @code{thermald} (default: @var{thermald})
20836 Package object of thermald.
20841 @node Audio Services
20842 @subsection Audio Services
20844 The @code{(gnu services audio)} module provides a service to start MPD
20845 (the Music Player Daemon).
20848 @subsubheading Music Player Daemon
20850 The Music Player Daemon (MPD) is a service that can play music while
20851 being controlled from the local machine or over the network by a variety
20854 The following example shows how one might run @code{mpd} as user
20855 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
20858 (service mpd-service-type
20864 @defvr {Scheme Variable} mpd-service-type
20865 The service type for @command{mpd}
20868 @deftp {Data Type} mpd-configuration
20869 Data type representing the configuration of @command{mpd}.
20872 @item @code{user} (default: @code{"mpd"})
20873 The user to run mpd as.
20875 @item @code{music-dir} (default: @code{"~/Music"})
20876 The directory to scan for music files.
20878 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
20879 The directory to store playlists.
20881 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
20882 The location of the music database.
20884 @item @code{state-file} (default: @code{"~/.mpd/state"})
20885 The location of the file that stores current MPD's state.
20887 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
20888 The location of the sticker database.
20890 @item @code{port} (default: @code{"6600"})
20891 The port to run mpd on.
20893 @item @code{address} (default: @code{"any"})
20894 The address that mpd will bind to. To use a Unix domain socket,
20895 an absolute path can be specified here.
20900 @node Virtualization Services
20901 @subsection Virtualization services
20903 The @code{(gnu services virtualization)} module provides services for
20904 the libvirt and virtlog daemons, as well as other virtualization-related
20907 @subsubheading Libvirt daemon
20908 @code{libvirtd} is the server side daemon component of the libvirt
20909 virtualization management system. This daemon runs on host servers
20910 and performs required management tasks for virtualized guests.
20912 @deffn {Scheme Variable} libvirt-service-type
20913 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
20914 Its value must be a @code{libvirt-configuration}.
20917 (service libvirt-service-type
20918 (libvirt-configuration
20919 (unix-sock-group "libvirt")
20920 (tls-port "16555")))
20924 @c Auto-generated with (generate-libvirt-documentation)
20925 Available @code{libvirt-configuration} fields are:
20927 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
20932 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
20933 Flag listening for secure TLS connections on the public TCP/IP port.
20934 must set @code{listen} for this to have any effect.
20936 It is necessary to setup a CA and issue server certificates before using
20939 Defaults to @samp{#t}.
20943 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
20944 Listen for unencrypted TCP connections on the public TCP/IP port. must
20945 set @code{listen} for this to have any effect.
20947 Using the TCP socket requires SASL authentication by default. Only SASL
20948 mechanisms which support data encryption are allowed. This is
20949 DIGEST_MD5 and GSSAPI (Kerberos5)
20951 Defaults to @samp{#f}.
20955 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
20956 Port for accepting secure TLS connections This can be a port number, or
20959 Defaults to @samp{"16514"}.
20963 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
20964 Port for accepting insecure TCP connections This can be a port number,
20967 Defaults to @samp{"16509"}.
20971 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
20972 IP address or hostname used for client connections.
20974 Defaults to @samp{"0.0.0.0"}.
20978 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
20979 Flag toggling mDNS advertisement of the libvirt service.
20981 Alternatively can disable for all services on a host by stopping the
20984 Defaults to @samp{#f}.
20988 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
20989 Default mDNS advertisement name. This must be unique on the immediate
20992 Defaults to @samp{"Virtualization Host <hostname>"}.
20996 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
20997 UNIX domain socket group ownership. This can be used to allow a
20998 'trusted' set of users access to management capabilities without
21001 Defaults to @samp{"root"}.
21005 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
21006 UNIX socket permissions for the R/O socket. This is used for monitoring
21009 Defaults to @samp{"0777"}.
21013 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
21014 UNIX socket permissions for the R/W socket. Default allows only root.
21015 If PolicyKit is enabled on the socket, the default will change to allow
21016 everyone (eg, 0777)
21018 Defaults to @samp{"0770"}.
21022 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
21023 UNIX socket permissions for the admin socket. Default allows only owner
21024 (root), do not change it unless you are sure to whom you are exposing
21027 Defaults to @samp{"0777"}.
21031 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
21032 The directory in which sockets will be found/created.
21034 Defaults to @samp{"/var/run/libvirt"}.
21038 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
21039 Authentication scheme for UNIX read-only sockets. By default socket
21040 permissions allow anyone to connect
21042 Defaults to @samp{"polkit"}.
21046 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
21047 Authentication scheme for UNIX read-write sockets. By default socket
21048 permissions only allow root. If PolicyKit support was compiled into
21049 libvirt, the default will be to use 'polkit' auth.
21051 Defaults to @samp{"polkit"}.
21055 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
21056 Authentication scheme for TCP sockets. If you don't enable SASL, then
21057 all TCP traffic is cleartext. Don't do this outside of a dev/test
21060 Defaults to @samp{"sasl"}.
21064 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
21065 Authentication scheme for TLS sockets. TLS sockets already have
21066 encryption provided by the TLS layer, and limited authentication is done
21069 It is possible to make use of any SASL authentication mechanism as well,
21070 by using 'sasl' for this option
21072 Defaults to @samp{"none"}.
21076 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
21077 API access control scheme.
21079 By default an authenticated user is allowed access to all APIs. Access
21080 drivers can place restrictions on this.
21082 Defaults to @samp{()}.
21086 @deftypevr {@code{libvirt-configuration} parameter} string key-file
21087 Server key file path. If set to an empty string, then no private key is
21090 Defaults to @samp{""}.
21094 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
21095 Server key file path. If set to an empty string, then no certificate is
21098 Defaults to @samp{""}.
21102 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
21103 Server key file path. If set to an empty string, then no CA certificate
21106 Defaults to @samp{""}.
21110 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
21111 Certificate revocation list path. If set to an empty string, then no
21114 Defaults to @samp{""}.
21118 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
21119 Disable verification of our own server certificates.
21121 When libvirtd starts it performs some sanity checks against its own
21124 Defaults to @samp{#f}.
21128 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
21129 Disable verification of client certificates.
21131 Client certificate verification is the primary authentication mechanism.
21132 Any client which does not present a certificate signed by the CA will be
21135 Defaults to @samp{#f}.
21139 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
21140 Whitelist of allowed x509 Distinguished Name.
21142 Defaults to @samp{()}.
21146 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
21147 Whitelist of allowed SASL usernames. The format for username depends on
21148 the SASL authentication mechanism.
21150 Defaults to @samp{()}.
21154 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
21155 Override the compile time default TLS priority string. The default is
21156 usually "NORMAL" unless overridden at build time. Only set this is it
21157 is desired for libvirt to deviate from the global default settings.
21159 Defaults to @samp{"NORMAL"}.
21163 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
21164 Maximum number of concurrent client connections to allow over all
21167 Defaults to @samp{5000}.
21171 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
21172 Maximum length of queue of connections waiting to be accepted by the
21173 daemon. Note, that some protocols supporting retransmission may obey
21174 this so that a later reattempt at connection succeeds.
21176 Defaults to @samp{1000}.
21180 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
21181 Maximum length of queue of accepted but not yet authenticated clients.
21182 Set this to zero to turn this feature off
21184 Defaults to @samp{20}.
21188 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
21189 Number of workers to start up initially.
21191 Defaults to @samp{5}.
21195 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
21196 Maximum number of worker threads.
21198 If the number of active clients exceeds @code{min-workers}, then more
21199 threads are spawned, up to max_workers limit. Typically you'd want
21200 max_workers to equal maximum number of clients allowed.
21202 Defaults to @samp{20}.
21206 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
21207 Number of priority workers. If all workers from above pool are stuck,
21208 some calls marked as high priority (notably domainDestroy) can be
21209 executed in this pool.
21211 Defaults to @samp{5}.
21215 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
21216 Total global limit on concurrent RPC calls.
21218 Defaults to @samp{20}.
21222 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
21223 Limit on concurrent requests from a single client connection. To avoid
21224 one client monopolizing the server this should be a small fraction of
21225 the global max_requests and max_workers parameter.
21227 Defaults to @samp{5}.
21231 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
21232 Same as @code{min-workers} but for the admin interface.
21234 Defaults to @samp{1}.
21238 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
21239 Same as @code{max-workers} but for the admin interface.
21241 Defaults to @samp{5}.
21245 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
21246 Same as @code{max-clients} but for the admin interface.
21248 Defaults to @samp{5}.
21252 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
21253 Same as @code{max-queued-clients} but for the admin interface.
21255 Defaults to @samp{5}.
21259 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
21260 Same as @code{max-client-requests} but for the admin interface.
21262 Defaults to @samp{5}.
21266 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
21267 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
21269 Defaults to @samp{3}.
21273 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
21276 A filter allows to select a different logging level for a given category
21277 of logs The format for a filter is one of:
21288 where @code{name} is a string which is matched against the category
21289 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
21290 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
21291 be a substring of the full category name, in order to match multiple
21292 similar categories), the optional "+" prefix tells libvirt to log stack
21293 trace for each message matching name, and @code{x} is the minimal level
21294 where matching messages should be logged:
21311 Multiple filters can be defined in a single filters statement, they just
21312 need to be separated by spaces.
21314 Defaults to @samp{"3:remote 4:event"}.
21318 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
21321 An output is one of the places to save logging information The format
21322 for an output can be:
21326 output goes to stderr
21328 @item x:syslog:name
21329 use syslog for the output and use the given name as the ident
21331 @item x:file:file_path
21332 output to a file, with the given filepath
21335 output to journald logging system
21339 In all case the x prefix is the minimal level, acting as a filter
21356 Multiple outputs can be defined, they just need to be separated by
21359 Defaults to @samp{"3:stderr"}.
21363 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
21364 Allows usage of the auditing subsystem to be altered
21368 0: disable all auditing
21371 1: enable auditing, only if enabled on host
21374 2: enable auditing, and exit if disabled on host.
21378 Defaults to @samp{1}.
21382 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
21383 Send audit messages via libvirt logging infrastructure.
21385 Defaults to @samp{#f}.
21389 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
21390 Host UUID. UUID must not have all digits be the same.
21392 Defaults to @samp{""}.
21396 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
21397 Source to read host UUID.
21401 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
21404 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
21408 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
21411 Defaults to @samp{"smbios"}.
21415 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
21416 A keepalive message is sent to a client after @code{keepalive_interval}
21417 seconds of inactivity to check if the client is still responding. If
21418 set to -1, libvirtd will never send keepalive requests; however clients
21419 can still send them and the daemon will send responses.
21421 Defaults to @samp{5}.
21425 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
21426 Maximum number of keepalive messages that are allowed to be sent to the
21427 client without getting any response before the connection is considered
21430 In other words, the connection is automatically closed approximately
21431 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
21432 the last message received from the client. When @code{keepalive-count}
21433 is set to 0, connections will be automatically closed after
21434 @code{keepalive-interval} seconds of inactivity without sending any
21435 keepalive messages.
21437 Defaults to @samp{5}.
21441 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
21442 Same as above but for admin interface.
21444 Defaults to @samp{5}.
21448 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
21449 Same as above but for admin interface.
21451 Defaults to @samp{5}.
21455 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
21456 Timeout for Open vSwitch calls.
21458 The @code{ovs-vsctl} utility is used for the configuration and its
21459 timeout option is set by default to 5 seconds to avoid potential
21460 infinite waits blocking libvirt.
21462 Defaults to @samp{5}.
21466 @c %end of autogenerated docs
21468 @subsubheading Virtlog daemon
21469 The virtlogd service is a server side daemon component of libvirt that is
21470 used to manage logs from virtual machine consoles.
21472 This daemon is not used directly by libvirt client applications, rather it
21473 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
21474 standalone daemon, the main @code{libvirtd} daemon can be restarted without
21475 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
21476 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
21478 @deffn {Scheme Variable} virtlog-service-type
21479 This is the type of the virtlog daemon.
21480 Its value must be a @code{virtlog-configuration}.
21483 (service virtlog-service-type
21484 (virtlog-configuration
21485 (max-clients 1000)))
21489 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
21490 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
21492 Defaults to @samp{3}.
21496 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
21499 A filter allows to select a different logging level for a given category
21500 of logs The format for a filter is one of:
21511 where @code{name} is a string which is matched against the category
21512 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
21513 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
21514 be a substring of the full category name, in order to match multiple
21515 similar categories), the optional "+" prefix tells libvirt to log stack
21516 trace for each message matching name, and @code{x} is the minimal level
21517 where matching messages should be logged:
21534 Multiple filters can be defined in a single filters statement, they just
21535 need to be separated by spaces.
21537 Defaults to @samp{"3:remote 4:event"}.
21541 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
21544 An output is one of the places to save logging information The format
21545 for an output can be:
21549 output goes to stderr
21551 @item x:syslog:name
21552 use syslog for the output and use the given name as the ident
21554 @item x:file:file_path
21555 output to a file, with the given filepath
21558 output to journald logging system
21562 In all case the x prefix is the minimal level, acting as a filter
21579 Multiple outputs can be defined, they just need to be separated by
21582 Defaults to @samp{"3:stderr"}.
21586 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
21587 Maximum number of concurrent client connections to allow over all
21590 Defaults to @samp{1024}.
21594 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
21595 Maximum file size before rolling over.
21597 Defaults to @samp{2MB}
21601 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
21602 Maximum number of backup files to keep.
21604 Defaults to @samp{3}
21608 @subsubheading Transparent Emulation with QEMU
21611 @cindex @code{binfmt_misc}
21612 @code{qemu-binfmt-service-type} provides support for transparent
21613 emulation of program binaries built for different architectures---e.g.,
21614 it allows you to transparently execute an ARMv7 program on an x86_64
21615 machine. It achieves this by combining the @uref{https://www.qemu.org,
21616 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
21618 @defvr {Scheme Variable} qemu-binfmt-service-type
21619 This is the type of the QEMU/binfmt service for transparent emulation.
21620 Its value must be a @code{qemu-binfmt-configuration} object, which
21621 specifies the QEMU package to use as well as the architecture we want to
21625 (service qemu-binfmt-service-type
21626 (qemu-binfmt-configuration
21627 (platforms (lookup-qemu-platforms "arm" "aarch64" "ppc"))))
21630 In this example, we enable transparent emulation for the ARM and aarch64
21631 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
21632 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
21633 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
21636 @deftp {Data Type} qemu-binfmt-configuration
21637 This is the configuration for the @code{qemu-binfmt} service.
21640 @item @code{platforms} (default: @code{'()})
21641 The list of emulated QEMU platforms. Each item must be a @dfn{platform
21642 object} as returned by @code{lookup-qemu-platforms} (see below).
21644 @item @code{guix-support?} (default: @code{#f})
21645 When it is true, QEMU and all its dependencies are added to the build
21646 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
21647 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
21648 handlers to be used within the build environment, which in turn means
21649 that you can transparently build programs for another architecture.
21651 For example, let's suppose you're on an x86_64 machine and you have this
21655 (service qemu-binfmt-service-type
21656 (qemu-binfmt-configuration
21657 (platforms (lookup-qemu-platforms "arm"))
21658 (guix-support? #t)))
21664 guix build -s armhf-linux inkscape
21668 and it will build Inkscape for ARMv7 @emph{as if it were a native
21669 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
21670 if you'd like to test a package build for an architecture you don't have
21673 @item @code{qemu} (default: @code{qemu})
21674 The QEMU package to use.
21678 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
21679 Return the list of QEMU platform objects corresponding to
21680 @var{platforms}@dots{}. @var{platforms} must be a list of strings
21681 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
21682 @code{"mips64el"}, and so on.
21685 @deffn {Scheme Procedure} qemu-platform? @var{obj}
21686 Return true if @var{obj} is a platform object.
21689 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
21690 Return the name of @var{platform}---a string such as @code{"arm"}.
21693 @node Version Control Services
21694 @subsection Version Control Services
21696 The @code{(gnu services version-control)} module provides a service to
21697 allow remote access to local Git repositories. There are three options:
21698 the @code{git-daemon-service}, which provides access to repositories via
21699 the @code{git://} unsecured TCP-based protocol, extending the
21700 @code{nginx} web server to proxy some requests to
21701 @code{git-http-backend}, or providing a web interface with
21702 @code{cgit-service-type}.
21704 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
21706 Return a service that runs @command{git daemon}, a simple TCP server to
21707 expose repositories over the Git protocol for anonymous access.
21709 The optional @var{config} argument should be a
21710 @code{<git-daemon-configuration>} object, by default it allows read-only
21711 access to exported@footnote{By creating the magic file
21712 "git-daemon-export-ok" in the repository directory.} repositories under
21717 @deftp {Data Type} git-daemon-configuration
21718 Data type representing the configuration for @code{git-daemon-service}.
21721 @item @code{package} (default: @var{git})
21722 Package object of the Git distributed version control system.
21724 @item @code{export-all?} (default: @var{#f})
21725 Whether to allow access for all Git repositories, even if they do not
21726 have the @file{git-daemon-export-ok} file.
21728 @item @code{base-path} (default: @file{/srv/git})
21729 Whether to remap all the path requests as relative to the given path.
21730 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
21731 then if you later try to pull @code{git://example.com/hello.git}, git
21732 daemon will interpret the path as @code{/srv/git/hello.git}.
21734 @item @code{user-path} (default: @var{#f})
21735 Whether to allow @code{~user} notation to be used in requests. When
21736 specified with empty string, requests to @code{git://host/~alice/foo} is
21737 taken as a request to access @code{foo} repository in the home directory
21738 of user @code{alice}. If @var{(user-path "path")} is specified, the
21739 same request is taken as a request to access @code{path/foo} repository
21740 in the home directory of user @code{alice}.
21742 @item @code{listen} (default: @var{'()})
21743 Whether to listen on specific IP addresses or hostnames, defaults to
21746 @item @code{port} (default: @var{#f})
21747 Whether to listen on an alternative port, which defaults to 9418.
21749 @item @code{whitelist} (default: @var{'()})
21750 If not empty, only allow access to this list of directories.
21752 @item @code{extra-options} (default: @var{'()})
21753 Extra options will be passed to @code{git daemon}, please run
21754 @command{man git-daemon} for more information.
21759 The @code{git://} protocol lacks authentication. When you pull from a
21760 repository fetched via @code{git://}, you don't know that the data you
21761 receive was modified is really coming from the specified host, and you
21762 have your connection is subject to eavesdropping. It's better to use an
21763 authenticated and encrypted transport, such as @code{https}. Although Git allows you
21764 to serve repositories using unsophisticated file-based web servers,
21765 there is a faster protocol implemented by the @code{git-http-backend}
21766 program. This program is the back-end of a proper Git web service. It
21767 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
21768 on running the necessary @code{fcgiwrap} daemon.
21770 Guix has a separate configuration data type for serving Git repositories
21773 @deftp {Data Type} git-http-configuration
21774 Data type representing the configuration for @code{git-http-service}.
21777 @item @code{package} (default: @var{git})
21778 Package object of the Git distributed version control system.
21780 @item @code{git-root} (default: @file{/srv/git})
21781 Directory containing the Git repositories to expose to the world.
21783 @item @code{export-all?} (default: @var{#f})
21784 Whether to expose access for all Git repositories in @var{git-root},
21785 even if they do not have the @file{git-daemon-export-ok} file.
21787 @item @code{uri-path} (default: @file{/git/})
21788 Path prefix for Git access. With the default @code{/git/} prefix, this
21789 will map @code{http://@var{server}/git/@var{repo}.git} to
21790 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
21791 with this prefix are not passed on to this Git instance.
21793 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
21794 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
21799 There is no @code{git-http-service-type}, currently; instead you can
21800 create an @code{nginx-location-configuration} from a
21801 @code{git-http-configuration} and then add that location to a web
21804 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
21805 [config=(git-http-configuration)]
21806 Compute an @code{nginx-location-configuration} that corresponds to the
21807 given Git http configuration. An example nginx service definition to
21808 serve the default @file{/srv/git} over HTTPS might be:
21811 (service nginx-service-type
21812 (nginx-configuration
21815 (nginx-server-configuration
21816 (listen '("443 ssl"))
21817 (server-name "git.my-host.org")
21819 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
21820 (ssl-certificate-key
21821 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
21824 (git-http-nginx-location-configuration
21825 (git-http-configuration (uri-path "/"))))))))))
21828 This example assumes that you are using Let's Encrypt to get your TLS
21829 certificate. @xref{Certificate Services}. The default @code{certbot}
21830 service will redirect all HTTP traffic on @code{git.my-host.org} to
21831 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
21832 system services. @xref{Web Services}.
21835 @subsubheading Cgit Service
21837 @cindex Cgit service
21838 @cindex Git, web interface
21839 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
21840 repositories written in C.
21842 The following example will configure the service with default values.
21843 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
21846 (service cgit-service-type)
21849 The @code{file-object} type designates either a file-like object
21850 (@pxref{G-Expressions, file-like objects}) or a string.
21852 @c %start of fragment
21854 Available @code{cgit-configuration} fields are:
21856 @deftypevr {@code{cgit-configuration} parameter} package package
21861 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
21862 NGINX configuration.
21866 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
21867 Specifies a command which will be invoked to format the content of about
21868 pages (both top-level and for each repository).
21870 Defaults to @samp{""}.
21874 @deftypevr {@code{cgit-configuration} parameter} string agefile
21875 Specifies a path, relative to each repository path, which can be used to
21876 specify the date and time of the youngest commit in the repository.
21878 Defaults to @samp{""}.
21882 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
21883 Specifies a command that will be invoked for authenticating repository
21886 Defaults to @samp{""}.
21890 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
21891 Flag which, when set to @samp{age}, enables date ordering in the branch
21892 ref list, and when set @samp{name} enables ordering by branch name.
21894 Defaults to @samp{"name"}.
21898 @deftypevr {@code{cgit-configuration} parameter} string cache-root
21899 Path used to store the cgit cache entries.
21901 Defaults to @samp{"/var/cache/cgit"}.
21905 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
21906 Number which specifies the time-to-live, in minutes, for the cached
21907 version of repository pages accessed with a fixed SHA1.
21909 Defaults to @samp{-1}.
21913 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
21914 Number which specifies the time-to-live, in minutes, for the cached
21915 version of repository pages accessed without a fixed SHA1.
21917 Defaults to @samp{5}.
21921 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
21922 Number which specifies the time-to-live, in minutes, for the cached
21923 version of the repository summary page.
21925 Defaults to @samp{5}.
21929 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
21930 Number which specifies the time-to-live, in minutes, for the cached
21931 version of the repository index page.
21933 Defaults to @samp{5}.
21937 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
21938 Number which specifies the time-to-live, in minutes, for the result of
21939 scanning a path for Git repositories.
21941 Defaults to @samp{15}.
21945 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
21946 Number which specifies the time-to-live, in minutes, for the cached
21947 version of the repository about page.
21949 Defaults to @samp{15}.
21953 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
21954 Number which specifies the time-to-live, in minutes, for the cached
21955 version of snapshots.
21957 Defaults to @samp{5}.
21961 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
21962 The maximum number of entries in the cgit cache. When set to @samp{0},
21963 caching is disabled.
21965 Defaults to @samp{0}.
21969 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
21970 Sort items in the repo list case sensitively.
21972 Defaults to @samp{#t}.
21976 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
21977 List of common prefixes which, when combined with a repository URL,
21978 generates valid clone URLs for the repository.
21980 Defaults to @samp{()}.
21984 @deftypevr {@code{cgit-configuration} parameter} list clone-url
21985 List of @code{clone-url} templates.
21987 Defaults to @samp{()}.
21991 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
21992 Command which will be invoked to format commit messages.
21994 Defaults to @samp{""}.
21998 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
21999 Flag which, when set to @samp{date}, enables strict date ordering in the
22000 commit log, and when set to @samp{topo} enables strict topological
22003 Defaults to @samp{"git log"}.
22007 @deftypevr {@code{cgit-configuration} parameter} file-object css
22008 URL which specifies the css document to include in all cgit pages.
22010 Defaults to @samp{"/share/cgit/cgit.css"}.
22014 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
22015 Specifies a command which will be invoked to format names and email
22016 address of committers, authors, and taggers, as represented in various
22017 places throughout the cgit interface.
22019 Defaults to @samp{""}.
22023 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
22024 Flag which, when set to @samp{#t}, will make cgit generate a HTML
22025 fragment suitable for embedding in other HTML pages.
22027 Defaults to @samp{#f}.
22031 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
22032 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
22033 commit history graph to the left of the commit messages in the
22034 repository log page.
22036 Defaults to @samp{#f}.
22040 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
22041 Flag which, when set to @samp{#t}, allows all filter settings to be
22042 overridden in repository-specific cgitrc files.
22044 Defaults to @samp{#f}.
22048 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
22049 Flag which, when set to @samp{#t}, allows users to follow a file in the
22052 Defaults to @samp{#f}.
22056 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
22057 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
22060 Defaults to @samp{#t}.
22064 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
22065 Flag which, when set to @samp{#t}, will make cgit generate extra links
22066 "summary", "commit", "tree" for each repo in the repository index.
22068 Defaults to @samp{#f}.
22072 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
22073 Flag which, when set to @samp{#t}, will make cgit display the owner of
22074 each repo in the repository index.
22076 Defaults to @samp{#t}.
22080 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
22081 Flag which, when set to @samp{#t}, will make cgit print the number of
22082 modified files for each commit on the repository log page.
22084 Defaults to @samp{#f}.
22088 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
22089 Flag which, when set to @samp{#t}, will make cgit print the number of
22090 added and removed lines for each commit on the repository log page.
22092 Defaults to @samp{#f}.
22096 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
22097 Flag which, when set to @code{#t}, will make cgit display remote
22098 branches in the summary and refs views.
22100 Defaults to @samp{#f}.
22104 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
22105 Flag which, when set to @code{1}, will make cgit use the subject of the
22106 parent commit as link text when generating links to parent commits in
22109 Defaults to @samp{#f}.
22113 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
22114 Flag which, when set to @samp{#t}, will make cgit use the subject of the
22115 parent commit as link text when generating links to parent commits in
22118 Defaults to @samp{#f}.
22122 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
22123 Flag which, when set to @samp{#t}, will make cgit generate linenumber
22124 links for plaintext blobs printed in the tree view.
22126 Defaults to @samp{#t}.
22130 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
22131 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
22132 set any repo specific settings.
22134 Defaults to @samp{#f}.
22138 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
22139 URL used as link to a shortcut icon for cgit.
22141 Defaults to @samp{"/favicon.ico"}.
22145 @deftypevr {@code{cgit-configuration} parameter} string footer
22146 The content of the file specified with this option will be included
22147 verbatim at the bottom of all pages (i.e.@: it replaces the standard
22148 "generated by..."@: message).
22150 Defaults to @samp{""}.
22154 @deftypevr {@code{cgit-configuration} parameter} string head-include
22155 The content of the file specified with this option will be included
22156 verbatim in the HTML HEAD section on all pages.
22158 Defaults to @samp{""}.
22162 @deftypevr {@code{cgit-configuration} parameter} string header
22163 The content of the file specified with this option will be included
22164 verbatim at the top of all pages.
22166 Defaults to @samp{""}.
22170 @deftypevr {@code{cgit-configuration} parameter} file-object include
22171 Name of a configfile to include before the rest of the current config-
22174 Defaults to @samp{""}.
22178 @deftypevr {@code{cgit-configuration} parameter} string index-header
22179 The content of the file specified with this option will be included
22180 verbatim above the repository index.
22182 Defaults to @samp{""}.
22186 @deftypevr {@code{cgit-configuration} parameter} string index-info
22187 The content of the file specified with this option will be included
22188 verbatim below the heading on the repository index page.
22190 Defaults to @samp{""}.
22194 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
22195 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
22196 in the servers timezone.
22198 Defaults to @samp{#f}.
22202 @deftypevr {@code{cgit-configuration} parameter} file-object logo
22203 URL which specifies the source of an image which will be used as a logo
22206 Defaults to @samp{"/share/cgit/cgit.png"}.
22210 @deftypevr {@code{cgit-configuration} parameter} string logo-link
22211 URL loaded when clicking on the cgit logo image.
22213 Defaults to @samp{""}.
22217 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
22218 Command which will be invoked to format the Owner column of the main
22221 Defaults to @samp{""}.
22225 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
22226 Number of items to display in atom feeds view.
22228 Defaults to @samp{10}.
22232 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
22233 Number of entries to list per page in "log" view.
22235 Defaults to @samp{50}.
22239 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
22240 Number of commit message characters to display in "log" view.
22242 Defaults to @samp{80}.
22246 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
22247 Specifies the number of entries to list per page on the repository index
22250 Defaults to @samp{50}.
22254 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
22255 Specifies the maximum number of repo description characters to display
22256 on the repository index page.
22258 Defaults to @samp{80}.
22262 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
22263 Specifies the maximum size of a blob to display HTML for in KBytes.
22265 Defaults to @samp{0}.
22269 @deftypevr {@code{cgit-configuration} parameter} string max-stats
22270 Maximum statistics period. Valid values are @samp{week},@samp{month},
22271 @samp{quarter} and @samp{year}.
22273 Defaults to @samp{""}.
22277 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
22278 Mimetype for the specified filename extension.
22280 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
22281 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
22282 "image/png") (svg "image/svg+xml"))}.
22286 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
22287 Specifies the file to use for automatic mimetype lookup.
22289 Defaults to @samp{""}.
22293 @deftypevr {@code{cgit-configuration} parameter} string module-link
22294 Text which will be used as the formatstring for a hyperlink when a
22295 submodule is printed in a directory listing.
22297 Defaults to @samp{""}.
22301 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
22302 If set to the value @samp{#t} caching will be disabled.
22304 Defaults to @samp{#f}.
22308 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
22309 If set to @samp{#t} showing full author email addresses will be
22312 Defaults to @samp{#f}.
22316 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
22317 Flag which, when set to @samp{#t}, will make cgit omit the standard
22318 header on all pages.
22320 Defaults to @samp{#f}.
22324 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
22325 A list of subdirectories inside of @code{repository-directory}, relative
22326 to it, that should loaded as Git repositories. An empty list means that
22327 all subdirectories will be loaded.
22329 Defaults to @samp{()}.
22333 @deftypevr {@code{cgit-configuration} parameter} file-object readme
22334 Text which will be used as default value for @code{cgit-repo-readme}.
22336 Defaults to @samp{""}.
22340 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
22341 If set to @code{#t} and @code{repository-directory} is enabled, if any
22342 repositories are found with a suffix of @code{.git}, this suffix will be
22343 removed for the URL and name.
22345 Defaults to @samp{#f}.
22349 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
22350 Maximum number of files to consider when detecting renames.
22352 Defaults to @samp{-1}.
22356 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
22357 The way in which repositories in each section are sorted.
22359 Defaults to @samp{""}.
22363 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
22364 Text used as content for the @code{robots} meta-tag.
22366 Defaults to @samp{("noindex" "nofollow")}.
22370 @deftypevr {@code{cgit-configuration} parameter} string root-desc
22371 Text printed below the heading on the repository index page.
22373 Defaults to @samp{"a fast webinterface for the git dscm"}.
22377 @deftypevr {@code{cgit-configuration} parameter} string root-readme
22378 The content of the file specified with this option will be included
22379 verbatim below thef "about" link on the repository index page.
22381 Defaults to @samp{""}.
22385 @deftypevr {@code{cgit-configuration} parameter} string root-title
22386 Text printed as heading on the repository index page.
22388 Defaults to @samp{""}.
22392 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
22393 If set to @samp{#t} and repository-directory is enabled,
22394 repository-directory will recurse into directories whose name starts
22395 with a period. Otherwise, repository-directory will stay away from such
22396 directories, considered as "hidden". Note that this does not apply to
22397 the ".git" directory in non-bare repos.
22399 Defaults to @samp{#f}.
22403 @deftypevr {@code{cgit-configuration} parameter} list snapshots
22404 Text which specifies the default set of snapshot formats that cgit
22405 generates links for.
22407 Defaults to @samp{()}.
22411 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
22412 Name of the directory to scan for repositories (represents
22415 Defaults to @samp{"/srv/git"}.
22419 @deftypevr {@code{cgit-configuration} parameter} string section
22420 The name of the current repository section - all repositories defined
22421 after this option will inherit the current section name.
22423 Defaults to @samp{""}.
22427 @deftypevr {@code{cgit-configuration} parameter} string section-sort
22428 Flag which, when set to @samp{1}, will sort the sections on the
22429 repository listing by name.
22431 Defaults to @samp{""}.
22435 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
22436 A number which, if defined prior to repository-directory, specifies how
22437 many path elements from each repo path to use as a default section name.
22439 Defaults to @samp{0}.
22443 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
22444 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
22447 Defaults to @samp{#f}.
22451 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
22452 Specifies a command which will be invoked to format plaintext blobs in
22455 Defaults to @samp{""}.
22459 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
22460 Specifies the number of branches to display in the repository "summary"
22463 Defaults to @samp{10}.
22467 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
22468 Specifies the number of log entries to display in the repository
22471 Defaults to @samp{10}.
22475 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
22476 Specifies the number of tags to display in the repository "summary"
22479 Defaults to @samp{10}.
22483 @deftypevr {@code{cgit-configuration} parameter} string strict-export
22484 Filename which, if specified, needs to be present within the repository
22485 for cgit to allow access to that repository.
22487 Defaults to @samp{""}.
22491 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
22492 URL which, if specified, will be used as root for all cgit links.
22494 Defaults to @samp{"/"}.
22498 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
22499 A list of @dfn{cgit-repo} records to use with config.
22501 Defaults to @samp{()}.
22503 Available @code{repository-cgit-configuration} fields are:
22505 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
22506 A mask of snapshot formats for this repo that cgit generates links for,
22507 restricted by the global @code{snapshots} setting.
22509 Defaults to @samp{()}.
22513 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
22514 Override the default @code{source-filter}.
22516 Defaults to @samp{""}.
22520 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
22521 The relative URL used to access the repository.
22523 Defaults to @samp{""}.
22527 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
22528 Override the default @code{about-filter}.
22530 Defaults to @samp{""}.
22534 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
22535 Flag which, when set to @samp{age}, enables date ordering in the branch
22536 ref list, and when set to @samp{name} enables ordering by branch name.
22538 Defaults to @samp{""}.
22542 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
22543 A list of URLs which can be used to clone repo.
22545 Defaults to @samp{()}.
22549 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
22550 Override the default @code{commit-filter}.
22552 Defaults to @samp{""}.
22556 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
22557 Flag which, when set to @samp{date}, enables strict date ordering in the
22558 commit log, and when set to @samp{topo} enables strict topological
22561 Defaults to @samp{""}.
22565 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
22566 The name of the default branch for this repository. If no such branch
22567 exists in the repository, the first branch name (when sorted) is used as
22568 default instead. By default branch pointed to by HEAD, or "master" if
22569 there is no suitable HEAD.
22571 Defaults to @samp{""}.
22575 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
22576 The value to show as repository description.
22578 Defaults to @samp{""}.
22582 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
22583 The value to show as repository homepage.
22585 Defaults to @samp{""}.
22589 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
22590 Override the default @code{email-filter}.
22592 Defaults to @samp{""}.
22596 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
22597 A flag which can be used to disable the global setting
22598 @code{enable-commit-graph?}.
22600 Defaults to @samp{disabled}.
22604 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
22605 A flag which can be used to disable the global setting
22606 @code{enable-log-filecount?}.
22608 Defaults to @samp{disabled}.
22612 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
22613 A flag which can be used to disable the global setting
22614 @code{enable-log-linecount?}.
22616 Defaults to @samp{disabled}.
22620 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
22621 Flag which, when set to @code{#t}, will make cgit display remote
22622 branches in the summary and refs views.
22624 Defaults to @samp{disabled}.
22628 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
22629 A flag which can be used to override the global setting
22630 @code{enable-subject-links?}.
22632 Defaults to @samp{disabled}.
22636 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
22637 A flag which can be used to override the global setting
22638 @code{enable-html-serving?}.
22640 Defaults to @samp{disabled}.
22644 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
22645 Flag which, when set to @code{#t}, hides the repository from the
22648 Defaults to @samp{#f}.
22652 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
22653 Flag which, when set to @samp{#t}, ignores the repository.
22655 Defaults to @samp{#f}.
22659 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
22660 URL which specifies the source of an image which will be used as a logo
22661 on this repo’s pages.
22663 Defaults to @samp{""}.
22667 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
22668 URL loaded when clicking on the cgit logo image.
22670 Defaults to @samp{""}.
22674 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
22675 Override the default @code{owner-filter}.
22677 Defaults to @samp{""}.
22681 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
22682 Text which will be used as the formatstring for a hyperlink when a
22683 submodule is printed in a directory listing. The arguments for the
22684 formatstring are the path and SHA1 of the submodule commit.
22686 Defaults to @samp{""}.
22690 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
22691 Text which will be used as the formatstring for a hyperlink when a
22692 submodule with the specified subdirectory path is printed in a directory
22695 Defaults to @samp{()}.
22699 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
22700 Override the default maximum statistics period.
22702 Defaults to @samp{""}.
22706 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
22707 The value to show as repository name.
22709 Defaults to @samp{""}.
22713 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
22714 A value used to identify the owner of the repository.
22716 Defaults to @samp{""}.
22720 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
22721 An absolute path to the repository directory.
22723 Defaults to @samp{""}.
22727 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
22728 A path (relative to repo) which specifies a file to include verbatim as
22729 the "About" page for this repo.
22731 Defaults to @samp{""}.
22735 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
22736 The name of the current repository section - all repositories defined
22737 after this option will inherit the current section name.
22739 Defaults to @samp{""}.
22743 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
22744 Extra options will be appended to cgitrc file.
22746 Defaults to @samp{()}.
22752 @deftypevr {@code{cgit-configuration} parameter} list extra-options
22753 Extra options will be appended to cgitrc file.
22755 Defaults to @samp{()}.
22760 @c %end of fragment
22762 However, it could be that you just want to get a @code{cgitrc} up and
22763 running. In that case, you can pass an @code{opaque-cgit-configuration}
22764 as a record to @code{cgit-service-type}. As its name indicates, an
22765 opaque configuration does not have easy reflective capabilities.
22767 Available @code{opaque-cgit-configuration} fields are:
22769 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
22773 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
22774 The contents of the @code{cgitrc}, as a string.
22777 For example, if your @code{cgitrc} is just the empty string, you
22778 could instantiate a cgit service like this:
22781 (service cgit-service-type
22782 (opaque-cgit-configuration
22786 @subsubheading Gitolite Service
22788 @cindex Gitolite service
22789 @cindex Git, hosting
22790 @uref{http://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
22791 repositories on a central server.
22793 Gitolite can handle multiple repositories and users, and supports flexible
22794 configuration of the permissions for the users on the repositories.
22796 The following example will configure Gitolite using the default @code{git}
22797 user, and the provided SSH public key.
22800 (service gitolite-service-type
22801 (gitolite-configuration
22802 (admin-pubkey (plain-file
22804 "ssh-rsa AAAA... guix@@example.com"))))
22807 Gitolite is configured through a special admin repository which you can clone,
22808 for example, if you setup Gitolite on @code{example.com}, you would run the
22809 following command to clone the admin repository.
22812 git clone git@@example.com:gitolite-admin
22815 When the Gitolite service is activated, the provided @code{admin-pubkey} will
22816 be inserted in to the @file{keydir} directory in the gitolite-admin
22817 repository. If this results in a change in the repository, it will be
22818 committed using the message ``gitolite setup by GNU Guix''.
22820 @deftp {Data Type} gitolite-configuration
22821 Data type representing the configuration for @code{gitolite-service-type}.
22824 @item @code{package} (default: @var{gitolite})
22825 Gitolite package to use.
22827 @item @code{user} (default: @var{git})
22828 User to use for Gitolite. This will be user that you use when accessing
22831 @item @code{group} (default: @var{git})
22832 Group to use for Gitolite.
22834 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
22835 Directory in which to store the Gitolite configuration and repositories.
22837 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
22838 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
22839 representing the configuration for Gitolite.
22841 @item @code{admin-pubkey} (default: @var{#f})
22842 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
22843 setup Gitolite. This will be inserted in to the @file{keydir} directory
22844 within the gitolite-admin repository.
22846 To specify the SSH key as a string, use the @code{plain-file} function.
22849 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
22855 @deftp {Data Type} gitolite-rc-file
22856 Data type representing the Gitolite RC file.
22859 @item @code{umask} (default: @code{#o0077})
22860 This controls the permissions Gitolite sets on the repositories and their
22863 A value like @code{#o0027} will give read access to the group used by Gitolite
22864 (by default: @code{git}). This is necessary when using Gitolite with software
22865 like cgit or gitweb.
22867 @item @code{git-config-keys} (default: @code{""})
22868 Gitolite allows you to set git config values using the "config" keyword. This
22869 setting allows control over the config keys to accept.
22871 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
22872 Set the role names allowed to be used by users running the perms command.
22874 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
22875 This setting controls the commands and features to enable within Gitolite.
22881 @node Game Services
22882 @subsection Game Services
22884 @subsubheading The Battle for Wesnoth Service
22886 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
22887 based tactical strategy game, with several single player campaigns, and
22888 multiplayer games (both networked and local).
22890 @defvar {Scheme Variable} wesnothd-service-type
22891 Service type for the wesnothd service. Its value must be a
22892 @code{wesnothd-configuration} object. To run wesnothd in the default
22893 configuration, instantiate it as:
22896 (service wesnothd-service-type)
22900 @deftp {Data Type} wesnothd-configuration
22901 Data type representing the configuration of @command{wesnothd}.
22904 @item @code{package} (default: @code{wesnoth-server})
22905 The wesnoth server package to use.
22907 @item @code{port} (default: @code{15000})
22908 The port to bind the server to.
22912 @node Miscellaneous Services
22913 @subsection Miscellaneous Services
22915 @cindex fingerprint
22916 @subsubheading Fingerprint Service
22918 The @code{(gnu services fingerprint)} module provides a DBus service to
22919 read and identify fingerprints via a fingerprint sensor.
22921 @defvr {Scheme Variable} fprintd-service-type
22922 The service type for @command{fprintd}, which provides the fingerprint
22923 reading capability.
22926 (service fprintd-service-type)
22931 @subsubheading System Control Service
22933 The @code{(gnu services sysctl)} provides a service to configure kernel
22934 parameters at boot.
22936 @defvr {Scheme Variable} sysctl-service-type
22937 The service type for @command{sysctl}, which modifies kernel parameters
22938 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
22942 (service sysctl-service-type
22943 (sysctl-configuration
22944 (settings '(("net.ipv4.ip_forward" . "1")))))
22948 @deftp {Data Type} sysctl-configuration
22949 The data type representing the configuration of @command{sysctl}.
22952 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
22953 The @command{sysctl} executable to use.
22955 @item @code{settings} (default: @code{'()})
22956 An association list specifies kernel parameters and their values.
22961 @subsubheading PC/SC Smart Card Daemon Service
22963 The @code{(gnu services security-token)} module provides the following service
22964 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
22965 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
22966 manager that coordinates communications with smart card readers, smart cards
22967 and cryptographic tokens that are connected to the system.
22969 @defvr {Scheme Variable} pcscd-service-type
22970 Service type for the @command{pcscd} service. Its value must be a
22971 @code{pcscd-configuration} object. To run pcscd in the default
22972 configuration, instantiate it as:
22975 (service pcscd-service-type)
22979 @deftp {Data Type} pcscd-configuration
22980 The data type representing the configuration of @command{pcscd}.
22983 @item @code{pcsc-lite} (default: @code{pcsc-lite})
22984 The pcsc-lite package that provides pcscd.
22985 @item @code{usb-drivers} (default: @code{(list ccid)})
22986 List of packages that provide USB drivers to pcscd. Drivers are expected to be
22987 under @file{pcsc/drivers} in the store directory of the package.
22992 @subsubheading Lirc Service
22994 The @code{(gnu services lirc)} module provides the following service.
22996 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
22997 [#:device #f] [#:driver #f] [#:config-file #f] @
22998 [#:extra-options '()]
22999 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
23000 decodes infrared signals from remote controls.
23002 Optionally, @var{device}, @var{driver} and @var{config-file}
23003 (configuration file name) may be specified. See @command{lircd} manual
23006 Finally, @var{extra-options} is a list of additional command-line options
23007 passed to @command{lircd}.
23011 @subsubheading Spice Service
23013 The @code{(gnu services spice)} module provides the following service.
23015 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
23016 Returns a service that runs @url{http://www.spice-space.org,VDAGENT}, a daemon
23017 that enables sharing the clipboard with a vm and setting the guest display
23018 resolution when the graphical console window resizes.
23021 @cindex inputattach
23022 @subsubheading inputattach Service
23024 @cindex tablet input, for Xorg
23025 @cindex touchscreen input, for Xorg
23026 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
23027 use input devices such as Wacom tablets, touchscreens, or joysticks with the
23028 Xorg display server.
23030 @deffn {Scheme Variable} inputattach-service-type
23031 Type of a service that runs @command{inputattach} on a device and
23032 dispatches events from it.
23035 @deftp {Data Type} inputattach-configuration
23037 @item @code{device-type} (default: @code{"wacom"})
23038 The type of device to connect to. Run @command{inputattach --help}, from the
23039 @code{inputattach} package, to see the list of supported device types.
23041 @item @code{device} (default: @code{"/dev/ttyS0"})
23042 The device file to connect to the device.
23044 @item @code{log-file} (default: @code{#f})
23045 If true, this must be the name of a file to log messages to.
23049 @subsection Dictionary Services
23051 The @code{(gnu services dict)} module provides the following service:
23053 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
23054 Return a service that runs the @command{dicod} daemon, an implementation
23055 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
23057 The optional @var{config} argument specifies the configuration for
23058 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
23059 default it serves the GNU Collaborative International Dictonary of English.
23061 You can add @command{open localhost} to your @file{~/.dico} file to make
23062 @code{localhost} the default server for @command{dico} client
23063 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
23066 @deftp {Data Type} dicod-configuration
23067 Data type representing the configuration of dicod.
23070 @item @code{dico} (default: @var{dico})
23071 Package object of the GNU Dico dictionary server.
23073 @item @code{interfaces} (default: @var{'("localhost")})
23074 This is the list of IP addresses and ports and possibly socket file
23075 names to listen to (@pxref{Server Settings, @code{listen} directive,,
23076 dico, GNU Dico Manual}).
23078 @item @code{handlers} (default: @var{'()})
23079 List of @code{<dicod-handler>} objects denoting handlers (module instances).
23081 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
23082 List of @code{<dicod-database>} objects denoting dictionaries to be served.
23086 @deftp {Data Type} dicod-handler
23087 Data type representing a dictionary handler (module instance).
23091 Name of the handler (module instance).
23093 @item @code{module} (default: @var{#f})
23094 Name of the dicod module of the handler (instance). If it is @code{#f},
23095 the module has the same name as the handler.
23096 (@pxref{Modules,,, dico, GNU Dico Manual}).
23098 @item @code{options}
23099 List of strings or gexps representing the arguments for the module handler
23103 @deftp {Data Type} dicod-database
23104 Data type representing a dictionary database.
23108 Name of the database, will be used in DICT commands.
23110 @item @code{handler}
23111 Name of the dicod handler (module instance) used by this database
23112 (@pxref{Handlers,,, dico, GNU Dico Manual}).
23114 @item @code{complex?} (default: @var{#f})
23115 Whether the database configuration complex. The complex configuration
23116 will need a corresponding @code{<dicod-handler>} object, otherwise not.
23118 @item @code{options}
23119 List of strings or gexps representing the arguments for the database
23120 (@pxref{Databases,,, dico, GNU Dico Manual}).
23124 @defvr {Scheme Variable} %dicod-database:gcide
23125 A @code{<dicod-database>} object serving the GNU Collaborative International
23126 Dictionary of English using the @code{gcide} package.
23129 The following is an example @code{dicod-service} configuration.
23132 (dicod-service #:config
23133 (dicod-configuration
23134 (handlers (list (dicod-handler
23138 (list #~(string-append "dbdir=" #$wordnet))))))
23139 (databases (list (dicod-database
23142 (handler "wordnet")
23143 (options '("database=wn")))
23144 %dicod-database:gcide))))
23148 @subsubheading Docker Service
23150 The @code{(gnu services docker)} module provides the following service.
23152 @defvr {Scheme Variable} docker-service-type
23154 This is the type of the service that runs @url{http://www.docker.com,Docker},
23155 a daemon that can execute application bundles (sometimes referred to as
23156 ``containers'') in isolated environments.
23160 @deftp {Data Type} docker-configuration
23161 This is the data type representing the configuration of Docker and Containerd.
23165 @item @code{package} (default: @code{docker})
23166 The Docker package to use.
23168 @item @code{containerd} (default: @var{containerd})
23169 The Containerd package to use.
23174 @node Setuid Programs
23175 @section Setuid Programs
23177 @cindex setuid programs
23178 Some programs need to run with ``root'' privileges, even when they are
23179 launched by unprivileged users. A notorious example is the
23180 @command{passwd} program, which users can run to change their
23181 password, and which needs to access the @file{/etc/passwd} and
23182 @file{/etc/shadow} files---something normally restricted to root, for
23183 obvious security reasons. To address that, these executables are
23184 @dfn{setuid-root}, meaning that they always run with root privileges
23185 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
23186 for more info about the setuid mechanism.)
23188 The store itself @emph{cannot} contain setuid programs: that would be a
23189 security issue since any user on the system can write derivations that
23190 populate the store (@pxref{The Store}). Thus, a different mechanism is
23191 used: instead of changing the setuid bit directly on files that are in
23192 the store, we let the system administrator @emph{declare} which programs
23193 should be setuid root.
23195 The @code{setuid-programs} field of an @code{operating-system}
23196 declaration contains a list of G-expressions denoting the names of
23197 programs to be setuid-root (@pxref{Using the Configuration System}).
23198 For instance, the @command{passwd} program, which is part of the Shadow
23199 package, can be designated by this G-expression (@pxref{G-Expressions}):
23202 #~(string-append #$shadow "/bin/passwd")
23205 A default set of setuid programs is defined by the
23206 @code{%setuid-programs} variable of the @code{(gnu system)} module.
23208 @defvr {Scheme Variable} %setuid-programs
23209 A list of G-expressions denoting common programs that are setuid-root.
23211 The list includes commands such as @command{passwd}, @command{ping},
23212 @command{su}, and @command{sudo}.
23215 Under the hood, the actual setuid programs are created in the
23216 @file{/run/setuid-programs} directory at system activation time. The
23217 files in this directory refer to the ``real'' binaries, which are in the
23220 @node X.509 Certificates
23221 @section X.509 Certificates
23223 @cindex HTTPS, certificates
23224 @cindex X.509 certificates
23226 Web servers available over HTTPS (that is, HTTP over the transport-layer
23227 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
23228 that the client can then use to @emph{authenticate} the server. To do
23229 that, clients verify that the server's certificate is signed by a
23230 so-called @dfn{certificate authority} (CA). But to verify the CA's
23231 signature, clients must have first acquired the CA's certificate.
23233 Web browsers such as GNU@tie{}IceCat include their own set of CA
23234 certificates, such that they are able to verify CA signatures
23237 However, most other programs that can talk HTTPS---@command{wget},
23238 @command{git}, @command{w3m}, etc.---need to be told where CA
23239 certificates can be found.
23241 @cindex @code{nss-certs}
23242 In Guix, this is done by adding a package that provides certificates
23243 to the @code{packages} field of the @code{operating-system} declaration
23244 (@pxref{operating-system Reference}). Guix includes one such package,
23245 @code{nss-certs}, which is a set of CA certificates provided as part of
23246 Mozilla's Network Security Services.
23248 Note that it is @emph{not} part of @var{%base-packages}, so you need to
23249 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
23250 most applications and libraries look for certificates by default, points
23251 to the certificates installed globally.
23253 Unprivileged users, including users of Guix on a foreign distro,
23254 can also install their own certificate package in
23255 their profile. A number of environment variables need to be defined so
23256 that applications and libraries know where to find them. Namely, the
23257 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
23258 variables. Some applications add their own environment variables; for
23259 instance, the Git version control system honors the certificate bundle
23260 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
23261 would typically run something like:
23264 $ guix package -i nss-certs
23265 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
23266 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
23267 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
23270 As another example, R requires the @code{CURL_CA_BUNDLE} environment
23271 variable to point to a certificate bundle, so you would have to run
23272 something like this:
23275 $ guix package -i nss-certs
23276 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
23279 For other applications you may want to look up the required environment
23280 variable in the relevant documentation.
23283 @node Name Service Switch
23284 @section Name Service Switch
23286 @cindex name service switch
23288 The @code{(gnu system nss)} module provides bindings to the
23289 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
23290 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
23291 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
23292 extended with new ``name'' lookup methods for system databases, which
23293 includes host names, service names, user accounts, and more (@pxref{Name
23294 Service Switch, System Databases and Name Service Switch,, libc, The GNU
23295 C Library Reference Manual}).
23297 The NSS configuration specifies, for each system database, which lookup
23298 method is to be used, and how the various methods are chained
23299 together---for instance, under which circumstances NSS should try the
23300 next method in the list. The NSS configuration is given in the
23301 @code{name-service-switch} field of @code{operating-system} declarations
23302 (@pxref{operating-system Reference, @code{name-service-switch}}).
23305 @cindex .local, host name lookup
23306 As an example, the declaration below configures the NSS to use the
23307 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
23308 back-end}, which supports host name lookups over multicast DNS (mDNS)
23309 for host names ending in @code{.local}:
23312 (name-service-switch
23313 (hosts (list %files ;first, check /etc/hosts
23315 ;; If the above did not succeed, try
23316 ;; with 'mdns_minimal'.
23318 (name "mdns_minimal")
23320 ;; 'mdns_minimal' is authoritative for
23321 ;; '.local'. When it returns "not found",
23322 ;; no need to try the next methods.
23323 (reaction (lookup-specification
23324 (not-found => return))))
23326 ;; Then fall back to DNS.
23330 ;; Finally, try with the "full" 'mdns'.
23335 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
23336 contains this configuration, so you will not have to type it if all you
23337 want is to have @code{.local} host lookup working.
23339 Note that, in this case, in addition to setting the
23340 @code{name-service-switch} of the @code{operating-system} declaration,
23341 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
23342 @code{avahi-service-type}}), or @var{%desktop-services}, which includes it
23343 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
23344 to the name service cache daemon (@pxref{Base Services,
23345 @code{nscd-service}}).
23347 For convenience, the following variables provide typical NSS
23350 @defvr {Scheme Variable} %default-nss
23351 This is the default name service switch configuration, a
23352 @code{name-service-switch} object.
23355 @defvr {Scheme Variable} %mdns-host-lookup-nss
23356 This is the name service switch configuration with support for host name
23357 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
23360 The reference for name service switch configuration is given below. It
23361 is a direct mapping of the configuration file format of the C library , so
23362 please refer to the C library manual for more information (@pxref{NSS
23363 Configuration File,,, libc, The GNU C Library Reference Manual}).
23364 Compared to the configuration file format of libc NSS, it has the advantage
23365 not only of adding this warm parenthetic feel that we like, but also
23366 static checks: you will know about syntax errors and typos as soon as you
23367 run @command{guix system}.
23369 @deftp {Data Type} name-service-switch
23371 This is the data type representation the configuration of libc's name
23372 service switch (NSS). Each field below represents one of the supported
23389 The system databases handled by the NSS. Each of these fields must be a
23390 list of @code{<name-service>} objects (see below).
23394 @deftp {Data Type} name-service
23396 This is the data type representing an actual name service and the
23397 associated lookup action.
23401 A string denoting the name service (@pxref{Services in the NSS
23402 configuration,,, libc, The GNU C Library Reference Manual}).
23404 Note that name services listed here must be visible to nscd. This is
23405 achieved by passing the @code{#:name-services} argument to
23406 @code{nscd-service} the list of packages providing the needed name
23407 services (@pxref{Base Services, @code{nscd-service}}).
23410 An action specified using the @code{lookup-specification} macro
23411 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
23412 Reference Manual}). For example:
23415 (lookup-specification (unavailable => continue)
23416 (success => return))
23421 @node Initial RAM Disk
23422 @section Initial RAM Disk
23425 @cindex initial RAM disk
23426 For bootstrapping purposes, the Linux-Libre kernel is passed an
23427 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
23428 root file system as well as an initialization script. The latter is
23429 responsible for mounting the real root file system, and for loading any
23430 kernel modules that may be needed to achieve that.
23432 The @code{initrd-modules} field of an @code{operating-system}
23433 declaration allows you to specify Linux-libre kernel modules that must
23434 be available in the initrd. In particular, this is where you would list
23435 modules needed to actually drive the hard disk where your root partition
23436 is---although the default value of @code{initrd-modules} should cover
23437 most use cases. For example, assuming you need the @code{megaraid_sas}
23438 module in addition to the default modules to be able to access your root
23439 file system, you would write:
23444 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
23447 @defvr {Scheme Variable} %base-initrd-modules
23448 This is the list of kernel modules included in the initrd by default.
23451 Furthermore, if you need lower-level customization, the @code{initrd}
23452 field of an @code{operating-system} declaration allows
23453 you to specify which initrd you would like to use. The @code{(gnu
23454 system linux-initrd)} module provides three ways to build an initrd: the
23455 high-level @code{base-initrd} procedure and the low-level
23456 @code{raw-initrd} and @code{expression->initrd} procedures.
23458 The @code{base-initrd} procedure is intended to cover most common uses.
23459 For example, if you want to add a bunch of kernel modules to be loaded
23460 at boot time, you can define the @code{initrd} field of the operating
23461 system declaration like this:
23464 (initrd (lambda (file-systems . rest)
23465 ;; Create a standard initrd but set up networking
23466 ;; with the parameters QEMU expects by default.
23467 (apply base-initrd file-systems
23468 #:qemu-networking? #t
23472 The @code{base-initrd} procedure also handles common use cases that
23473 involves using the system as a QEMU guest, or as a ``live'' system with
23474 volatile root file system.
23476 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
23477 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
23478 such as trying to guess which kernel modules and packages should be included
23479 to the initrd. An example use of @code{raw-initrd} is when a user has
23480 a custom Linux kernel configuration and default kernel modules included by
23481 @code{base-initrd} are not available.
23483 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
23484 honors several options passed on the Linux kernel command line
23485 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
23486 @code{-append} option of QEMU), notably:
23489 @item --load=@var{boot}
23490 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
23491 program, once it has mounted the root file system.
23493 Guix uses this option to yield control to a boot program that runs the
23494 service activation programs and then spawns the GNU@tie{}Shepherd, the
23495 initialization system.
23497 @item --root=@var{root}
23498 Mount @var{root} as the root file system. @var{root} can be a
23499 device name like @code{/dev/sda1}, a file system label, or a file system
23502 @item --system=@var{system}
23503 Have @file{/run/booted-system} and @file{/run/current-system} point to
23506 @item modprobe.blacklist=@var{modules}@dots{}
23507 @cindex module, black-listing
23508 @cindex black list, of kernel modules
23509 Instruct the initial RAM disk as well as the @command{modprobe} command
23510 (from the kmod package) to refuse to load @var{modules}. @var{modules}
23511 must be a comma-separated list of module names---e.g.,
23512 @code{usbkbd,9pnet}.
23515 Start a read-eval-print loop (REPL) from the initial RAM disk before it
23516 tries to load kernel modules and to mount the root file system. Our
23517 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
23518 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
23519 Manual}, for more information on Guile's REPL.
23523 Now that you know all the features that initial RAM disks produced by
23524 @code{base-initrd} and @code{raw-initrd} provide,
23525 here is how to use it and customize it further.
23528 @cindex initial RAM disk
23529 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
23530 [#:linux-modules '()] [#:mapped-devices '()] @
23531 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
23532 Return a derivation that builds a raw initrd. @var{file-systems} is
23533 a list of file systems to be mounted by the initrd, possibly in addition to
23534 the root file system specified on the kernel command line via @code{--root}.
23535 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
23536 @var{mapped-devices} is a list of device mappings to realize before
23537 @var{file-systems} are mounted (@pxref{Mapped Devices}).
23538 @var{helper-packages} is a list of packages to be copied in the initrd. It may
23539 include @code{e2fsck/static} or other packages needed by the initrd to check
23540 the root file system.
23542 When @var{qemu-networking?} is true, set up networking with the standard QEMU
23543 parameters. When @var{virtio?} is true, load additional modules so that the
23544 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
23546 When @var{volatile-root?} is true, the root file system is writable but any changes
23550 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
23551 [#:mapped-devices '()] [#:qemu-networking? #f] [#:volatile-root? #f]@
23552 [#:linux-modules '()]
23553 Return as a file-like object a generic initrd, with kernel
23554 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
23555 mounted by the initrd, possibly in addition to the root file system specified
23556 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
23557 mappings to realize before @var{file-systems} are mounted.
23559 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
23561 The initrd is automatically populated with all the kernel modules necessary
23562 for @var{file-systems} and for the given options. Additional kernel
23563 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
23564 loaded at boot time in the order in which they appear.
23567 Needless to say, the initrds we produce and use embed a
23568 statically-linked Guile, and the initialization program is a Guile
23569 program. That gives a lot of flexibility. The
23570 @code{expression->initrd} procedure builds such an initrd, given the
23571 program to run in that initrd.
23573 @deffn {Scheme Procedure} expression->initrd @var{exp} @
23574 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
23575 Return as a file-like object a Linux initrd (a gzipped cpio archive)
23576 containing @var{guile} and that evaluates @var{exp}, a G-expression,
23577 upon booting. All the derivations referenced by @var{exp} are
23578 automatically copied to the initrd.
23581 @node Bootloader Configuration
23582 @section Bootloader Configuration
23585 @cindex boot loader
23587 The operating system supports multiple bootloaders. The bootloader is
23588 configured using @code{bootloader-configuration} declaration. All the
23589 fields of this structure are bootloader agnostic except for one field,
23590 @code{bootloader} that indicates the bootloader to be configured and
23593 Some of the bootloaders do not honor every field of
23594 @code{bootloader-configuration}. For instance, the extlinux
23595 bootloader does not support themes and thus ignores the @code{theme}
23598 @deftp {Data Type} bootloader-configuration
23599 The type of a bootloader configuration declaration.
23603 @item @code{bootloader}
23604 @cindex EFI, bootloader
23605 @cindex UEFI, bootloader
23606 @cindex BIOS, bootloader
23607 The bootloader to use, as a @code{bootloader} object. For now
23608 @code{grub-bootloader}, @code{grub-efi-bootloader},
23609 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
23611 @vindex grub-efi-bootloader
23612 @code{grub-efi-bootloader} allows to boot on modern systems using the
23613 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
23614 use if the installation image contains a @file{/sys/firmware/efi} directory
23615 when you boot it on your system.
23617 @vindex grub-bootloader
23618 @code{grub-bootloader} allows you to boot in particular Intel-based machines
23619 in ``legacy'' BIOS mode.
23621 @cindex ARM, bootloaders
23622 @cindex AArch64, bootloaders
23623 Available bootloaders are described in @code{(gnu bootloader @dots{})}
23624 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
23625 of bootloaders for a wide range of ARM and AArch64 systems, using the
23626 @uref{http://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
23628 @item @code{target}
23629 This is a string denoting the target onto which to install the
23632 The interpretation depends on the bootloader in question. For
23633 @code{grub-bootloader}, for example, it should be a device name understood by
23634 the bootloader @command{installer} command, such as @code{/dev/sda} or
23635 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
23636 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
23637 system, usually @file{/boot/efi}.
23639 @item @code{menu-entries} (default: @code{()})
23640 A possibly empty list of @code{menu-entry} objects (see below), denoting
23641 entries to appear in the bootloader menu, in addition to the current
23642 system entry and the entry pointing to previous system generations.
23644 @item @code{default-entry} (default: @code{0})
23645 The index of the default boot menu entry. Index 0 is for the entry of the
23648 @item @code{timeout} (default: @code{5})
23649 The number of seconds to wait for keyboard input before booting. Set to
23650 0 to boot immediately, and to -1 to wait indefinitely.
23652 @item @code{theme} (default: @var{#f})
23653 The bootloader theme object describing the theme to use. If no theme
23654 is provided, some bootloaders might use a default theme, that's true
23657 @item @code{terminal-outputs} (default: @code{'gfxterm})
23658 The output terminals used for the bootloader boot menu, as a list of
23659 symbols. GRUB accepts the values: @code{console}, @code{serial},
23660 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
23661 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
23662 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
23663 configuration,,, grub,GNU GRUB manual}).
23665 @item @code{terminal-inputs} (default: @code{'()})
23666 The input terminals used for the bootloader boot menu, as a list of
23667 symbols. For GRUB, the default is the native platform terminal as
23668 determined at run-time. GRUB accepts the values: @code{console},
23669 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
23670 @code{usb_keyboard}. This field corresponds to the GRUB variable
23671 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
23674 @item @code{serial-unit} (default: @code{#f})
23675 The serial unit used by the bootloader, as an integer from 0 to 3.
23676 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
23677 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
23679 @item @code{serial-speed} (default: @code{#f})
23680 The speed of the serial interface, as an integer. For GRUB, the
23681 default value is chosen at run-time; currently GRUB chooses
23682 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
23689 Should you want to list additional boot menu entries @i{via} the
23690 @code{menu-entries} field above, you will need to create them with the
23691 @code{menu-entry} form. For example, imagine you want to be able to
23692 boot another distro (hard to imagine!), you can define a menu entry
23697 (label "The Other Distro")
23698 (linux "/boot/old/vmlinux-2.6.32")
23699 (linux-arguments '("root=/dev/sda2"))
23700 (initrd "/boot/old/initrd"))
23705 @deftp {Data Type} menu-entry
23706 The type of an entry in the bootloader menu.
23711 The label to show in the menu---e.g., @code{"GNU"}.
23714 The Linux kernel image to boot, for example:
23717 (file-append linux-libre "/bzImage")
23720 For GRUB, it is also possible to specify a device explicitly in the
23721 file path using GRUB's device naming convention (@pxref{Naming
23722 convention,,, grub, GNU GRUB manual}), for example:
23725 "(hd0,msdos1)/boot/vmlinuz"
23728 If the device is specified explicitly as above, then the @code{device}
23729 field is ignored entirely.
23731 @item @code{linux-arguments} (default: @code{()})
23732 The list of extra Linux kernel command-line arguments---e.g.,
23733 @code{("console=ttyS0")}.
23735 @item @code{initrd}
23736 A G-Expression or string denoting the file name of the initial RAM disk
23737 to use (@pxref{G-Expressions}).
23738 @item @code{device} (default: @code{#f})
23739 The device where the kernel and initrd are to be found---i.e., for GRUB,
23740 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
23742 This may be a file system label (a string), a file system UUID (a
23743 bytevector, @pxref{File Systems}), or @code{#f}, in which case
23744 the bootloader will search the device containing the file specified by
23745 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
23746 must @emph{not} be an OS device name such as @file{/dev/sda1}.
23751 @c FIXME: Write documentation once it's stable.
23752 Fow now only GRUB has theme support. GRUB themes are created using
23753 the @code{grub-theme} form, which is not documented yet.
23755 @defvr {Scheme Variable} %default-theme
23756 This is the default GRUB theme used by the operating system if no
23757 @code{theme} field is specified in @code{bootloader-configuration}
23760 It comes with a fancy background image displaying the GNU and Guix
23765 @node Invoking guix system
23766 @section Invoking @code{guix system}
23768 Once you have written an operating system declaration as seen in the
23769 previous section, it can be @dfn{instantiated} using the @command{guix
23770 system} command. The synopsis is:
23773 guix system @var{options}@dots{} @var{action} @var{file}
23776 @var{file} must be the name of a file containing an
23777 @code{operating-system} declaration. @var{action} specifies how the
23778 operating system is instantiated. Currently the following values are
23783 Display available service type definitions that match the given regular
23784 expressions, sorted by relevance:
23787 $ guix system search console font
23788 name: console-fonts
23789 location: gnu/services/base.scm:729:2
23790 extends: shepherd-root
23791 description: Install the given fonts on the specified ttys (fonts are
23792 + per virtual console on GNU/Linux). The value of this service is a list
23793 + of tty/font pairs like:
23795 + '(("tty1" . "LatGrkCyr-8x16"))
23799 location: gnu/services/base.scm:1048:2
23800 extends: shepherd-root
23801 description: Provide console login using the `mingetty' program.
23805 location: gnu/services/base.scm:775:2
23807 description: Provide a console log-in service as specified by its
23808 + configuration value, a `login-configuration' object.
23814 As for @command{guix package --search}, the result is written in
23815 @code{recutils} format, which makes it easy to filter the output
23816 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
23819 Build the operating system described in @var{file}, activate it, and
23820 switch to it@footnote{This action (and the related actions
23821 @code{switch-generation} and @code{roll-back}) are usable only on
23822 systems already running Guix System.}.
23824 This effects all the configuration specified in @var{file}: user
23825 accounts, system services, global package list, setuid programs, etc.
23826 The command starts system services specified in @var{file} that are not
23827 currently running; if a service is currently running this command will
23828 arrange for it to be upgraded the next time it is stopped (e.g.@: by
23829 @code{herd stop X} or @code{herd restart X}).
23831 This command creates a new generation whose number is one greater than
23832 the current generation (as reported by @command{guix system
23833 list-generations}). If that generation already exists, it will be
23834 overwritten. This behavior mirrors that of @command{guix package}
23835 (@pxref{Invoking guix package}).
23837 It also adds a bootloader menu entry for the new OS configuration,
23838 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
23839 entries for older configurations to a submenu, allowing you to choose
23840 an older system generation at boot time should you need it.
23843 @c The paragraph below refers to the problem discussed at
23844 @c <http://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
23845 It is highly recommended to run @command{guix pull} once before you run
23846 @command{guix system reconfigure} for the first time (@pxref{Invoking
23847 guix pull}). Failing to do that you would see an older version of Guix
23848 once @command{reconfigure} has completed.
23851 @item switch-generation
23852 @cindex generations
23853 Switch to an existing system generation. This action atomically
23854 switches the system profile to the specified system generation. It
23855 also rearranges the system's existing bootloader menu entries. It
23856 makes the menu entry for the specified system generation the default,
23857 and it moves the entries for the other generatiors to a submenu, if
23858 supported by the bootloader being used. The next time the system
23859 boots, it will use the specified system generation.
23861 The bootloader itself is not being reinstalled when using this
23862 command. Thus, the installed bootloader is used with an updated
23863 configuration file.
23865 The target generation can be specified explicitly by its generation
23866 number. For example, the following invocation would switch to system
23870 guix system switch-generation 7
23873 The target generation can also be specified relative to the current
23874 generation with the form @code{+N} or @code{-N}, where @code{+3} means
23875 ``3 generations ahead of the current generation,'' and @code{-1} means
23876 ``1 generation prior to the current generation.'' When specifying a
23877 negative value such as @code{-1}, you must precede it with @code{--} to
23878 prevent it from being parsed as an option. For example:
23881 guix system switch-generation -- -1
23884 Currently, the effect of invoking this action is @emph{only} to switch
23885 the system profile to an existing generation and rearrange the
23886 bootloader menu entries. To actually start using the target system
23887 generation, you must reboot after running this action. In the future,
23888 it will be updated to do the same things as @command{reconfigure},
23889 like activating and deactivating services.
23891 This action will fail if the specified generation does not exist.
23894 @cindex rolling back
23895 Switch to the preceding system generation. The next time the system
23896 boots, it will use the preceding system generation. This is the inverse
23897 of @command{reconfigure}, and it is exactly the same as invoking
23898 @command{switch-generation} with an argument of @code{-1}.
23900 Currently, as with @command{switch-generation}, you must reboot after
23901 running this action to actually start using the preceding system
23904 @item delete-generations
23905 @cindex deleting system generations
23906 @cindex saving space
23907 Delete system generations, making them candidates for garbage collection
23908 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
23911 This works in the same way as @command{guix package --delete-generations}
23912 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
23913 arguments, all system generations but the current one are deleted:
23916 guix system delete-generations
23919 You can also select the generations you want to delete. The example below
23920 deletes all the system generations that are more than two month old:
23923 guix system delete-generations 2m
23926 Running this command automatically reinstalls the bootloader with an updated
23927 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
23928 longer lists the generations that have been deleted.
23931 Build the derivation of the operating system, which includes all the
23932 configuration files and programs needed to boot and run the system.
23933 This action does not actually install anything.
23936 Populate the given directory with all the files necessary to run the
23937 operating system specified in @var{file}. This is useful for first-time
23938 installations of Guix System. For instance:
23941 guix system init my-os-config.scm /mnt
23944 copies to @file{/mnt} all the store items required by the configuration
23945 specified in @file{my-os-config.scm}. This includes configuration
23946 files, packages, and so on. It also creates other essential files
23947 needed for the system to operate correctly---e.g., the @file{/etc},
23948 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
23950 This command also installs bootloader on the target specified in
23951 @file{my-os-config}, unless the @option{--no-bootloader} option was
23955 @cindex virtual machine
23957 @anchor{guix system vm}
23958 Build a virtual machine that contains the operating system declared in
23959 @var{file}, and return a script to run that virtual machine (VM).
23962 The @code{vm} action and others below
23963 can use KVM support in the Linux-libre kernel. Specifically, if the
23964 machine has hardware virtualization support, the corresponding
23965 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
23966 must exist and be readable and writable by the user and by the
23967 build users of the daemon (@pxref{Build Environment Setup}).
23970 Arguments given to the script are passed to QEMU as in the example
23971 below, which enables networking and requests 1@tie{}GiB of RAM for the
23975 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
23978 The VM shares its store with the host system.
23980 Additional file systems can be shared between the host and the VM using
23981 the @code{--share} and @code{--expose} command-line options: the former
23982 specifies a directory to be shared with write access, while the latter
23983 provides read-only access to the shared directory.
23985 The example below creates a VM in which the user's home directory is
23986 accessible read-only, and where the @file{/exchange} directory is a
23987 read-write mapping of @file{$HOME/tmp} on the host:
23990 guix system vm my-config.scm \
23991 --expose=$HOME --share=$HOME/tmp=/exchange
23994 On GNU/Linux, the default is to boot directly to the kernel; this has
23995 the advantage of requiring only a very tiny root disk image since the
23996 store of the host can then be mounted.
23998 The @code{--full-boot} option forces a complete boot sequence, starting
23999 with the bootloader. This requires more disk space since a root image
24000 containing at least the kernel, initrd, and bootloader data files must
24001 be created. The @code{--image-size} option can be used to specify the
24004 @cindex System images, creation in various formats
24005 @cindex Creating system images in various formats
24008 @itemx docker-image
24009 Return a virtual machine, disk image, or Docker image of the operating
24010 system declared in @var{file} that stands alone. By default,
24011 @command{guix system} estimates the size of the image needed to store
24012 the system, but you can use the @option{--image-size} option to specify
24013 a value. Docker images are built to contain exactly what they need, so
24014 the @option{--image-size} option is ignored in the case of
24015 @code{docker-image}.
24017 You can specify the root file system type by using the
24018 @option{--file-system-type} option. It defaults to @code{ext4}.
24020 When using @code{vm-image}, the returned image is in qcow2 format, which
24021 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
24022 for more information on how to run the image in a virtual machine.
24024 When using @code{disk-image}, a raw disk image is produced; it can be
24025 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
24026 the device corresponding to a USB stick, one can copy the image to it
24027 using the following command:
24030 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
24033 When using @code{docker-image}, a Docker image is produced. Guix builds
24034 the image from scratch, not from a pre-existing Docker base image. As a
24035 result, it contains @emph{exactly} what you define in the operating
24036 system configuration file. You can then load the image and launch a
24037 Docker container using commands like the following:
24040 image_id="$(docker load < guix-system-docker-image.tar.gz)"
24041 docker run -e GUIX_NEW_SYSTEM=/var/guix/profiles/system \\
24042 --entrypoint /var/guix/profiles/system/profile/bin/guile \\
24043 $image_id /var/guix/profiles/system/boot
24046 This command starts a new Docker container from the specified image. It
24047 will boot the Guix system in the usual manner, which means it will
24048 start any services you have defined in the operating system
24049 configuration. Depending on what you run in the Docker container, it
24050 may be necessary to give the container additional permissions. For
24051 example, if you intend to build software using Guix inside of the Docker
24052 container, you may need to pass the @option{--privileged} option to
24056 Return a script to run the operating system declared in @var{file}
24057 within a container. Containers are a set of lightweight isolation
24058 mechanisms provided by the kernel Linux-libre. Containers are
24059 substantially less resource-demanding than full virtual machines since
24060 the kernel, shared objects, and other resources can be shared with the
24061 host system; this also means they provide thinner isolation.
24063 Currently, the script must be run as root in order to support more than
24064 a single user and group. The container shares its store with the host
24067 As with the @code{vm} action (@pxref{guix system vm}), additional file
24068 systems to be shared between the host and container can be specified
24069 using the @option{--share} and @option{--expose} options:
24072 guix system container my-config.scm \
24073 --expose=$HOME --share=$HOME/tmp=/exchange
24077 This option requires Linux-libre 3.19 or newer.
24082 @var{options} can contain any of the common build options (@pxref{Common
24083 Build Options}). In addition, @var{options} can contain one of the
24087 @item --expression=@var{expr}
24088 @itemx -e @var{expr}
24089 Consider the operating-system @var{expr} evaluates to.
24090 This is an alternative to specifying a file which evaluates to an
24092 This is used to generate the Guix system installer @pxref{Building the
24093 Installation Image}).
24095 @item --system=@var{system}
24096 @itemx -s @var{system}
24097 Attempt to build for @var{system} instead of the host system type.
24098 This works as per @command{guix build} (@pxref{Invoking guix build}).
24102 Return the derivation file name of the given operating system without
24105 @item --file-system-type=@var{type}
24106 @itemx -t @var{type}
24107 For the @code{disk-image} action, create a file system of the given
24108 @var{type} on the image.
24110 When this option is omitted, @command{guix system} uses @code{ext4}.
24112 @cindex ISO-9660 format
24113 @cindex CD image format
24114 @cindex DVD image format
24115 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
24116 for burning on CDs and DVDs.
24118 @item --image-size=@var{size}
24119 For the @code{vm-image} and @code{disk-image} actions, create an image
24120 of the given @var{size}. @var{size} may be a number of bytes, or it may
24121 include a unit as a suffix (@pxref{Block size, size specifications,,
24122 coreutils, GNU Coreutils}).
24124 When this option is omitted, @command{guix system} computes an estimate
24125 of the image size as a function of the size of the system declared in
24128 @item --root=@var{file}
24129 @itemx -r @var{file}
24130 Make @var{file} a symlink to the result, and register it as a garbage
24133 @item --skip-checks
24134 Skip pre-installation safety checks.
24136 By default, @command{guix system init} and @command{guix system
24137 reconfigure} perform safety checks: they make sure the file systems that
24138 appear in the @code{operating-system} declaration actually exist
24139 (@pxref{File Systems}), and that any Linux kernel modules that may be
24140 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
24141 RAM Disk}). Passing this option skips these tests altogether.
24144 @cindex on-error strategy
24145 @cindex error strategy
24146 @item --on-error=@var{strategy}
24147 Apply @var{strategy} when an error occurs when reading @var{file}.
24148 @var{strategy} may be one of the following:
24151 @item nothing-special
24152 Report the error concisely and exit. This is the default strategy.
24155 Likewise, but also display a backtrace.
24158 Report the error and enter Guile's debugger. From there, you can run
24159 commands such as @code{,bt} to get a backtrace, @code{,locals} to
24160 display local variable values, and more generally inspect the state of the
24161 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
24162 a list of available debugging commands.
24166 Once you have built, configured, re-configured, and re-re-configured
24167 your Guix installation, you may find it useful to list the operating
24168 system generations available on disk---and that you can choose from the
24169 bootloader boot menu:
24173 @item list-generations
24174 List a summary of each generation of the operating system available on
24175 disk, in a human-readable way. This is similar to the
24176 @option{--list-generations} option of @command{guix package}
24177 (@pxref{Invoking guix package}).
24179 Optionally, one can specify a pattern, with the same syntax that is used
24180 in @command{guix package --list-generations}, to restrict the list of
24181 generations displayed. For instance, the following command displays
24182 generations that are up to 10 days old:
24185 $ guix system list-generations 10d
24190 The @command{guix system} command has even more to offer! The following
24191 sub-commands allow you to visualize how your system services relate to
24194 @anchor{system-extension-graph}
24197 @item extension-graph
24198 Emit in Dot/Graphviz format to standard output the @dfn{service
24199 extension graph} of the operating system defined in @var{file}
24200 (@pxref{Service Composition}, for more information on service
24206 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
24209 produces a PDF file showing the extension relations among services.
24211 @anchor{system-shepherd-graph}
24212 @item shepherd-graph
24213 Emit in Dot/Graphviz format to standard output the @dfn{dependency
24214 graph} of shepherd services of the operating system defined in
24215 @var{file}. @xref{Shepherd Services}, for more information and for an
24220 @node Running Guix in a VM
24221 @section Running Guix in a Virtual Machine
24223 @cindex virtual machine
24224 To run Guix in a virtual machine (VM), one can either use the
24225 pre-built Guix VM image distributed at
24226 @indicateurl{https://alpha.gnu.org/gnu/guix/guix-system-vm-image-@value{VERSION}.@var{system}.xz}
24227 , or build their own virtual machine image using @command{guix system
24228 vm-image} (@pxref{Invoking guix system}). The returned image is in
24229 qcow2 format, which the @uref{http://qemu.org/, QEMU emulator} can
24233 If you built your own image, you must copy it out of the store
24234 (@pxref{The Store}) and give yourself permission to write to the copy
24235 before you can use it. When invoking QEMU, you must choose a system
24236 emulator that is suitable for your hardware platform. Here is a minimal
24237 QEMU invocation that will boot the result of @command{guix system
24238 vm-image} on x86_64 hardware:
24241 $ qemu-system-x86_64 \
24242 -net user -net nic,model=virtio \
24243 -enable-kvm -m 256 /tmp/qemu-image
24246 Here is what each of these options means:
24249 @item qemu-system-x86_64
24250 This specifies the hardware platform to emulate. This should match the
24254 Enable the unprivileged user-mode network stack. The guest OS can
24255 access the host but not vice versa. This is the simplest way to get the
24258 @item -net nic,model=virtio
24259 You must create a network interface of a given model. If you do not
24260 create a NIC, the boot will fail. Assuming your hardware platform is
24261 x86_64, you can get a list of available NIC models by running
24262 @command{qemu-system-x86_64 -net nic,model=help}.
24265 If your system has hardware virtualization extensions, enabling the
24266 virtual machine support (KVM) of the Linux kernel will make things run
24270 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
24271 which may be insufficient for some operations.
24273 @item /tmp/qemu-image
24274 The file name of the qcow2 image.
24277 The default @command{run-vm.sh} script that is returned by an invocation of
24278 @command{guix system vm} does not add a @command{-net user} flag by default.
24279 To get network access from within the vm add the @code{(dhcp-client-service)}
24280 to your system definition and start the VM using
24281 @command{`guix system vm config.scm` -net user}. An important caveat of using
24282 @command{-net user} for networking is that @command{ping} will not work, because
24283 it uses the ICMP protocol. You'll have to use a different command to check for
24284 network connectivity, for example @command{guix download}.
24286 @subsection Connecting Through SSH
24290 To enable SSH inside a VM you need to add a SSH server like @code{(dropbear-service)}
24291 or @code{(lsh-service)} to your VM. The @code{(lsh-service}) doesn't currently
24292 boot unsupervised. It requires you to type some characters to initialize the
24293 randomness generator. In addition you need to forward the SSH port, 22 by
24294 default, to the host. You can do this with
24297 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
24300 To connect to the VM you can run
24303 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
24306 The @command{-p} tells @command{ssh} the port you want to connect to.
24307 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
24308 every time you modify your @command{config.scm} file and the
24309 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
24310 connection to an unknown host every time you connect.
24312 @subsection Using @command{virt-viewer} with Spice
24314 As an alternative to the default @command{qemu} graphical client you can
24315 use the @command{remote-viewer} from the @command{virt-viewer} package. To
24316 connect pass the @command{-spice port=5930,disable-ticketing} flag to
24317 @command{qemu}. See previous section for further information on how to do this.
24319 Spice also allows you to do some nice stuff like share your clipboard with your
24320 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
24323 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
24324 -chardev spicevmc,name=vdagent,id=vdagent
24325 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
24326 name=com.redhat.spice.0
24329 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
24331 @node Defining Services
24332 @section Defining Services
24334 The previous sections show the available services and how one can combine
24335 them in an @code{operating-system} declaration. But how do we define
24336 them in the first place? And what is a service anyway?
24339 * Service Composition:: The model for composing services.
24340 * Service Types and Services:: Types and services.
24341 * Service Reference:: API reference.
24342 * Shepherd Services:: A particular type of service.
24345 @node Service Composition
24346 @subsection Service Composition
24350 Here we define a @dfn{service} as, broadly, something that extends the
24351 functionality of the operating system. Often a service is a process---a
24352 @dfn{daemon}---started when the system boots: a secure shell server, a
24353 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
24354 whose execution can be triggered by another daemon---e.g., an FTP server
24355 started by @command{inetd} or a D-Bus service activated by
24356 @command{dbus-daemon}. Occasionally, a service does not map to a
24357 daemon. For instance, the ``account'' service collects user accounts
24358 and makes sure they exist when the system runs; the ``udev'' service
24359 collects device management rules and makes them available to the eudev
24360 daemon; the @file{/etc} service populates the @file{/etc} directory
24363 @cindex service extensions
24364 Guix system services are connected by @dfn{extensions}. For instance, the
24365 secure shell service @emph{extends} the Shepherd---the
24366 initialization system, running as PID@tie{}1---by giving it the command
24367 lines to start and stop the secure shell daemon (@pxref{Networking
24368 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
24369 service by passing it its @file{.service} specification, and extends the
24370 udev service by passing it device management rules (@pxref{Desktop
24371 Services, @code{upower-service}}); the Guix daemon service extends the
24372 Shepherd by passing it the command lines to start and stop the daemon,
24373 and extends the account service by passing it a list of required build
24374 user accounts (@pxref{Base Services}).
24376 All in all, services and their ``extends'' relations form a directed
24377 acyclic graph (DAG). If we represent services as boxes and extensions
24378 as arrows, a typical system might provide something like this:
24380 @image{images/service-graph,,5in,Typical service extension graph.}
24382 @cindex system service
24383 At the bottom, we see the @dfn{system service}, which produces the
24384 directory containing everything to run and boot the system, as returned
24385 by the @command{guix system build} command. @xref{Service Reference},
24386 to learn about the other service types shown here.
24387 @xref{system-extension-graph, the @command{guix system extension-graph}
24388 command}, for information on how to generate this representation for a
24389 particular operating system definition.
24391 @cindex service types
24392 Technically, developers can define @dfn{service types} to express these
24393 relations. There can be any number of services of a given type on the
24394 system---for instance, a system running two instances of the GNU secure
24395 shell server (lsh) has two instances of @code{lsh-service-type}, with
24396 different parameters.
24398 The following section describes the programming interface for service
24399 types and services.
24401 @node Service Types and Services
24402 @subsection Service Types and Services
24404 A @dfn{service type} is a node in the DAG described above. Let us start
24405 with a simple example, the service type for the Guix build daemon
24406 (@pxref{Invoking guix-daemon}):
24409 (define guix-service-type
24413 (list (service-extension shepherd-root-service-type guix-shepherd-service)
24414 (service-extension account-service-type guix-accounts)
24415 (service-extension activation-service-type guix-activation)))
24416 (default-value (guix-configuration))))
24420 It defines three things:
24424 A name, whose sole purpose is to make inspection and debugging easier.
24427 A list of @dfn{service extensions}, where each extension designates the
24428 target service type and a procedure that, given the parameters of the
24429 service, returns a list of objects to extend the service of that type.
24431 Every service type has at least one service extension. The only
24432 exception is the @dfn{boot service type}, which is the ultimate service.
24435 Optionally, a default value for instances of this type.
24438 In this example, @var{guix-service-type} extends three services:
24441 @item shepherd-root-service-type
24442 The @var{guix-shepherd-service} procedure defines how the Shepherd
24443 service is extended. Namely, it returns a @code{<shepherd-service>}
24444 object that defines how @command{guix-daemon} is started and stopped
24445 (@pxref{Shepherd Services}).
24447 @item account-service-type
24448 This extension for this service is computed by @var{guix-accounts},
24449 which returns a list of @code{user-group} and @code{user-account}
24450 objects representing the build user accounts (@pxref{Invoking
24453 @item activation-service-type
24454 Here @var{guix-activation} is a procedure that returns a gexp, which is
24455 a code snippet to run at ``activation time''---e.g., when the service is
24459 A service of this type is instantiated like this:
24462 (service guix-service-type
24463 (guix-configuration
24465 (use-substitutes? #f)))
24468 The second argument to the @code{service} form is a value representing
24469 the parameters of this specific service instance.
24470 @xref{guix-configuration-type, @code{guix-configuration}}, for
24471 information about the @code{guix-configuration} data type. When the
24472 value is omitted, the default value specified by
24473 @code{guix-service-type} is used:
24476 (service guix-service-type)
24479 @var{guix-service-type} is quite simple because it extends other
24480 services but is not extensible itself.
24482 @c @subsubsubsection Extensible Service Types
24484 The service type for an @emph{extensible} service looks like this:
24487 (define udev-service-type
24488 (service-type (name 'udev)
24490 (list (service-extension shepherd-root-service-type
24491 udev-shepherd-service)))
24493 (compose concatenate) ;concatenate the list of rules
24494 (extend (lambda (config rules)
24496 (($ <udev-configuration> udev initial-rules)
24497 (udev-configuration
24498 (udev udev) ;the udev package to use
24499 (rules (append initial-rules rules)))))))))
24502 This is the service type for the
24503 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
24504 management daemon}. Compared to the previous example, in addition to an
24505 extension of @var{shepherd-root-service-type}, we see two new fields:
24509 This is the procedure to @dfn{compose} the list of extensions to
24510 services of this type.
24512 Services can extend the udev service by passing it lists of rules; we
24513 compose those extensions simply by concatenating them.
24516 This procedure defines how the value of the service is @dfn{extended} with
24517 the composition of the extensions.
24519 Udev extensions are composed into a list of rules, but the udev service
24520 value is itself a @code{<udev-configuration>} record. So here, we
24521 extend that record by appending the list of rules it contains to the
24522 list of contributed rules.
24525 This is a string giving an overview of the service type. The string can
24526 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
24527 @command{guix system search} command searches these strings and displays
24528 them (@pxref{Invoking guix system}).
24531 There can be only one instance of an extensible service type such as
24532 @var{udev-service-type}. If there were more, the
24533 @code{service-extension} specifications would be ambiguous.
24535 Still here? The next section provides a reference of the programming
24536 interface for services.
24538 @node Service Reference
24539 @subsection Service Reference
24541 We have seen an overview of service types (@pxref{Service Types and
24542 Services}). This section provides a reference on how to manipulate
24543 services and service types. This interface is provided by the
24544 @code{(gnu services)} module.
24546 @deffn {Scheme Procedure} service @var{type} [@var{value}]
24547 Return a new service of @var{type}, a @code{<service-type>} object (see
24548 below.) @var{value} can be any object; it represents the parameters of
24549 this particular service instance.
24551 When @var{value} is omitted, the default value specified by @var{type}
24552 is used; if @var{type} does not specify a default value, an error is
24555 For instance, this:
24558 (service openssh-service-type)
24562 is equivalent to this:
24565 (service openssh-service-type
24566 (openssh-configuration))
24569 In both cases the result is an instance of @code{openssh-service-type}
24570 with the default configuration.
24573 @deffn {Scheme Procedure} service? @var{obj}
24574 Return true if @var{obj} is a service.
24577 @deffn {Scheme Procedure} service-kind @var{service}
24578 Return the type of @var{service}---i.e., a @code{<service-type>} object.
24581 @deffn {Scheme Procedure} service-value @var{service}
24582 Return the value associated with @var{service}. It represents its
24586 Here is an example of how a service is created and manipulated:
24590 (service nginx-service-type
24591 (nginx-configuration
24593 (log-directory log-directory)
24594 (run-directory run-directory)
24595 (file config-file))))
24600 (eq? (service-kind s) nginx-service-type)
24604 The @code{modify-services} form provides a handy way to change the
24605 parameters of some of the services of a list such as
24606 @var{%base-services} (@pxref{Base Services, @code{%base-services}}). It
24607 evaluates to a list of services. Of course, you could always use
24608 standard list combinators such as @code{map} and @code{fold} to do that
24609 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
24610 @code{modify-services} simply provides a more concise form for this
24613 @deffn {Scheme Syntax} modify-services @var{services} @
24614 (@var{type} @var{variable} => @var{body}) @dots{}
24616 Modify the services listed in @var{services} according to the given
24617 clauses. Each clause has the form:
24620 (@var{type} @var{variable} => @var{body})
24623 where @var{type} is a service type---e.g.,
24624 @code{guix-service-type}---and @var{variable} is an identifier that is
24625 bound within the @var{body} to the service parameters---e.g., a
24626 @code{guix-configuration} instance---of the original service of that
24629 The @var{body} should evaluate to the new service parameters, which will
24630 be used to configure the new service. This new service will replace the
24631 original in the resulting list. Because a service's service parameters
24632 are created using @code{define-record-type*}, you can write a succinct
24633 @var{body} that evaluates to the new service parameters by using the
24634 @code{inherit} feature that @code{define-record-type*} provides.
24636 @xref{Using the Configuration System}, for example usage.
24640 Next comes the programming interface for service types. This is
24641 something you want to know when writing new service definitions, but not
24642 necessarily when simply looking for ways to customize your
24643 @code{operating-system} declaration.
24645 @deftp {Data Type} service-type
24646 @cindex service type
24647 This is the representation of a @dfn{service type} (@pxref{Service Types
24652 This is a symbol, used only to simplify inspection and debugging.
24654 @item @code{extensions}
24655 A non-empty list of @code{<service-extension>} objects (see below).
24657 @item @code{compose} (default: @code{#f})
24658 If this is @code{#f}, then the service type denotes services that cannot
24659 be extended---i.e., services that do not receive ``values'' from other
24662 Otherwise, it must be a one-argument procedure. The procedure is called
24663 by @code{fold-services} and is passed a list of values collected from
24664 extensions. It may return any single value.
24666 @item @code{extend} (default: @code{#f})
24667 If this is @code{#f}, services of this type cannot be extended.
24669 Otherwise, it must be a two-argument procedure: @code{fold-services}
24670 calls it, passing it the initial value of the service as the first
24671 argument and the result of applying @code{compose} to the extension
24672 values as the second argument. It must return a value that is a valid
24673 parameter value for the service instance.
24676 @xref{Service Types and Services}, for examples.
24679 @deffn {Scheme Procedure} service-extension @var{target-type} @
24681 Return a new extension for services of type @var{target-type}.
24682 @var{compute} must be a one-argument procedure: @code{fold-services}
24683 calls it, passing it the value associated with the service that provides
24684 the extension; it must return a valid value for the target service.
24687 @deffn {Scheme Procedure} service-extension? @var{obj}
24688 Return true if @var{obj} is a service extension.
24691 Occasionally, you might want to simply extend an existing service. This
24692 involves creating a new service type and specifying the extension of
24693 interest, which can be verbose; the @code{simple-service} procedure
24694 provides a shorthand for this.
24696 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
24697 Return a service that extends @var{target} with @var{value}. This works
24698 by creating a singleton service type @var{name}, of which the returned
24699 service is an instance.
24701 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
24705 (simple-service 'my-mcron-job mcron-service-type
24706 #~(job '(next-hour (3)) "guix gc -F 2G"))
24710 At the core of the service abstraction lies the @code{fold-services}
24711 procedure, which is responsible for ``compiling'' a list of services
24712 down to a single directory that contains everything needed to boot and
24713 run the system---the directory shown by the @command{guix system build}
24714 command (@pxref{Invoking guix system}). In essence, it propagates
24715 service extensions down the service graph, updating each node parameters
24716 on the way, until it reaches the root node.
24718 @deffn {Scheme Procedure} fold-services @var{services} @
24719 [#:target-type @var{system-service-type}]
24720 Fold @var{services} by propagating their extensions down to the root of
24721 type @var{target-type}; return the root service adjusted accordingly.
24724 Lastly, the @code{(gnu services)} module also defines several essential
24725 service types, some of which are listed below.
24727 @defvr {Scheme Variable} system-service-type
24728 This is the root of the service graph. It produces the system directory
24729 as returned by the @command{guix system build} command.
24732 @defvr {Scheme Variable} boot-service-type
24733 The type of the ``boot service'', which produces the @dfn{boot script}.
24734 The boot script is what the initial RAM disk runs when booting.
24737 @defvr {Scheme Variable} etc-service-type
24738 The type of the @file{/etc} service. This service is used to create
24739 files under @file{/etc} and can be extended by
24740 passing it name/file tuples such as:
24743 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
24746 In this example, the effect would be to add an @file{/etc/issue} file
24747 pointing to the given file.
24750 @defvr {Scheme Variable} setuid-program-service-type
24751 Type for the ``setuid-program service''. This service collects lists of
24752 executable file names, passed as gexps, and adds them to the set of
24753 setuid-root programs on the system (@pxref{Setuid Programs}).
24756 @defvr {Scheme Variable} profile-service-type
24757 Type of the service that populates the @dfn{system profile}---i.e., the
24758 programs under @file{/run/current-system/profile}. Other services can
24759 extend it by passing it lists of packages to add to the system profile.
24763 @node Shepherd Services
24764 @subsection Shepherd Services
24766 @cindex shepherd services
24768 @cindex init system
24769 The @code{(gnu services shepherd)} module provides a way to define
24770 services managed by the GNU@tie{}Shepherd, which is the
24771 initialization system---the first process that is started when the
24772 system boots, also known as PID@tie{}1
24773 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
24775 Services in the Shepherd can depend on each other. For instance, the
24776 SSH daemon may need to be started after the syslog daemon has been
24777 started, which in turn can only happen once all the file systems have
24778 been mounted. The simple operating system defined earlier (@pxref{Using
24779 the Configuration System}) results in a service graph like this:
24781 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
24783 You can actually generate such a graph for any operating system
24784 definition using the @command{guix system shepherd-graph} command
24785 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
24787 The @var{%shepherd-root-service} is a service object representing
24788 PID@tie{}1, of type @var{shepherd-root-service-type}; it can be extended
24789 by passing it lists of @code{<shepherd-service>} objects.
24791 @deftp {Data Type} shepherd-service
24792 The data type representing a service managed by the Shepherd.
24795 @item @code{provision}
24796 This is a list of symbols denoting what the service provides.
24798 These are the names that may be passed to @command{herd start},
24799 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
24800 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
24801 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
24803 @item @code{requirements} (default: @code{'()})
24804 List of symbols denoting the Shepherd services this one depends on.
24806 @item @code{respawn?} (default: @code{#t})
24807 Whether to restart the service when it stops, for instance when the
24808 underlying process dies.
24811 @itemx @code{stop} (default: @code{#~(const #f)})
24812 The @code{start} and @code{stop} fields refer to the Shepherd's
24813 facilities to start and stop processes (@pxref{Service De- and
24814 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
24815 G-expressions that get expanded in the Shepherd configuration file
24816 (@pxref{G-Expressions}).
24818 @item @code{actions} (default: @code{'()})
24819 @cindex actions, of Shepherd services
24820 This is a list of @code{shepherd-action} objects (see below) defining
24821 @dfn{actions} supported by the service, in addition to the standard
24822 @code{start} and @code{stop} actions. Actions listed here become available as
24823 @command{herd} sub-commands:
24826 herd @var{action} @var{service} [@var{arguments}@dots{}]
24829 @item @code{documentation}
24830 A documentation string, as shown when running:
24833 herd doc @var{service-name}
24836 where @var{service-name} is one of the symbols in @var{provision}
24837 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
24839 @item @code{modules} (default: @var{%default-modules})
24840 This is the list of modules that must be in scope when @code{start} and
24841 @code{stop} are evaluated.
24846 @deftp {Data Type} shepherd-action
24847 This is the data type that defines additional actions implemented by a
24848 Shepherd service (see above).
24852 Symbol naming the action.
24854 @item documentation
24855 This is a documentation string for the action. It can be viewed by running:
24858 herd doc @var{service} action @var{action}
24862 This should be a gexp that evaluates to a procedure of at least one argument,
24863 which is the ``running value'' of the service (@pxref{Slots of services,,,
24864 shepherd, The GNU Shepherd Manual}).
24867 The following example defines an action called @code{say-hello} that kindly
24873 (documentation "Say hi!")
24874 (procedure #~(lambda (running . args)
24875 (format #t "Hello, friend! arguments: ~s\n"
24880 Assuming this action is added to the @code{example} service, then you can do:
24883 # herd say-hello example
24884 Hello, friend! arguments: ()
24885 # herd say-hello example a b c
24886 Hello, friend! arguments: ("a" "b" "c")
24889 This, as you can see, is a fairly sophisticated way to say hello.
24890 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
24894 @defvr {Scheme Variable} shepherd-root-service-type
24895 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
24897 This is the service type that extensions target when they want to create
24898 shepherd services (@pxref{Service Types and Services}, for an example).
24899 Each extension must pass a list of @code{<shepherd-service>}.
24902 @defvr {Scheme Variable} %shepherd-root-service
24903 This service represents PID@tie{}1.
24907 @node Documentation
24908 @chapter Documentation
24910 @cindex documentation, searching for
24911 @cindex searching for documentation
24912 @cindex Info, documentation format
24914 @cindex manual pages
24915 In most cases packages installed with Guix come with documentation.
24916 There are two main documentation formats: ``Info'', a browseable
24917 hypertext format used for GNU software, and ``manual pages'' (or ``man
24918 pages''), the linear documentation format traditionally found on Unix.
24919 Info manuals are accessed with the @command{info} command or with Emacs,
24920 and man pages are accessed using @command{man}.
24922 You can look for documentation of software installed on your system by
24923 keyword. For example, the following command searches for information
24924 about ``TLS'' in Info manuals:
24928 "(emacs)Network Security" -- STARTTLS
24929 "(emacs)Network Security" -- TLS
24930 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
24931 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
24936 The command below searches for the same keyword in man pages:
24940 SSL (7) - OpenSSL SSL/TLS library
24941 certtool (1) - GnuTLS certificate tool
24945 These searches are purely local to your computer so you have the
24946 guarantee that documentation you find corresponds to what you have
24947 actually installed, you can access it off-line, and your privacy is
24950 Once you have these results, you can view the relevant documentation by
24954 $ info "(gnutls)Core TLS API"
24964 Info manuals contain sections and indices as well as hyperlinks like
24965 those found in Web pages. The @command{info} reader (@pxref{Top, Info
24966 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
24967 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
24968 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
24969 Introduction}, for an introduction to Info navigation.
24971 @node Installing Debugging Files
24972 @chapter Installing Debugging Files
24974 @cindex debugging files
24975 Program binaries, as produced by the GCC compilers for instance, are
24976 typically written in the ELF format, with a section containing
24977 @dfn{debugging information}. Debugging information is what allows the
24978 debugger, GDB, to map binary code to source code; it is required to
24979 debug a compiled program in good conditions.
24981 The problem with debugging information is that is takes up a fair amount
24982 of disk space. For example, debugging information for the GNU C Library
24983 weighs in at more than 60 MiB. Thus, as a user, keeping all the
24984 debugging info of all the installed programs is usually not an option.
24985 Yet, space savings should not come at the cost of an impediment to
24986 debugging---especially in the GNU system, which should make it easier
24987 for users to exert their computing freedom (@pxref{GNU Distribution}).
24989 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
24990 mechanism that allows users to get the best of both worlds: debugging
24991 information can be stripped from the binaries and stored in separate
24992 files. GDB is then able to load debugging information from those files,
24993 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
24996 The GNU distribution takes advantage of this by storing debugging
24997 information in the @code{lib/debug} sub-directory of a separate package
24998 output unimaginatively called @code{debug} (@pxref{Packages with
24999 Multiple Outputs}). Users can choose to install the @code{debug} output
25000 of a package when they need it. For instance, the following command
25001 installs the debugging information for the GNU C Library and for GNU
25005 guix package -i glibc:debug guile:debug
25008 GDB must then be told to look for debug files in the user's profile, by
25009 setting the @code{debug-file-directory} variable (consider setting it
25010 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
25014 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
25017 From there on, GDB will pick up debugging information from the
25018 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
25020 In addition, you will most likely want GDB to be able to show the source
25021 code being debugged. To do that, you will have to unpack the source
25022 code of the package of interest (obtained with @code{guix build
25023 --source}, @pxref{Invoking guix build}), and to point GDB to that source
25024 directory using the @code{directory} command (@pxref{Source Path,
25025 @code{directory},, gdb, Debugging with GDB}).
25027 @c XXX: keep me up-to-date
25028 The @code{debug} output mechanism in Guix is implemented by the
25029 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
25030 opt-in---debugging information is available only for the packages
25031 with definitions explicitly declaring a @code{debug} output. This may be
25032 changed to opt-out in the future if our build farm servers can handle
25033 the load. To check whether a package has a @code{debug} output, use
25034 @command{guix package --list-available} (@pxref{Invoking guix package}).
25037 @node Security Updates
25038 @chapter Security Updates
25040 @cindex security updates
25041 @cindex security vulnerabilities
25042 Occasionally, important security vulnerabilities are discovered in software
25043 packages and must be patched. Guix developers try hard to keep track of
25044 known vulnerabilities and to apply fixes as soon as possible in the
25045 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
25046 containing only security updates.) The @command{guix lint} tool helps
25047 developers find out about vulnerable versions of software packages in the
25052 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
25053 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
25054 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
25058 @xref{Invoking guix lint}, for more information.
25061 As of version @value{VERSION}, the feature described below is considered
25065 Guix follows a functional
25066 package management discipline (@pxref{Introduction}), which implies
25067 that, when a package is changed, @emph{every package that depends on it}
25068 must be rebuilt. This can significantly slow down the deployment of
25069 fixes in core packages such as libc or Bash, since basically the whole
25070 distribution would need to be rebuilt. Using pre-built binaries helps
25071 (@pxref{Substitutes}), but deployment may still take more time than
25075 To address this, Guix implements @dfn{grafts}, a mechanism that allows
25076 for fast deployment of critical updates without the costs associated
25077 with a whole-distribution rebuild. The idea is to rebuild only the
25078 package that needs to be patched, and then to ``graft'' it onto packages
25079 explicitly installed by the user and that were previously referring to
25080 the original package. The cost of grafting is typically very low, and
25081 order of magnitudes lower than a full rebuild of the dependency chain.
25083 @cindex replacements of packages, for grafts
25084 For instance, suppose a security update needs to be applied to Bash.
25085 Guix developers will provide a package definition for the ``fixed''
25086 Bash, say @var{bash-fixed}, in the usual way (@pxref{Defining
25087 Packages}). Then, the original package definition is augmented with a
25088 @code{replacement} field pointing to the package containing the bug fix:
25095 (replacement bash-fixed)))
25098 From there on, any package depending directly or indirectly on Bash---as
25099 reported by @command{guix gc --requisites} (@pxref{Invoking guix
25100 gc})---that is installed is automatically ``rewritten'' to refer to
25101 @var{bash-fixed} instead of @var{bash}. This grafting process takes
25102 time proportional to the size of the package, usually less than a
25103 minute for an ``average'' package on a recent machine. Grafting is
25104 recursive: when an indirect dependency requires grafting, then grafting
25105 ``propagates'' up to the package that the user is installing.
25107 Currently, the length of the name and version of the graft and that of
25108 the package it replaces (@var{bash-fixed} and @var{bash} in the example
25109 above) must be equal. This restriction mostly comes from the fact that
25110 grafting works by patching files, including binary files, directly.
25111 Other restrictions may apply: for instance, when adding a graft to a
25112 package providing a shared library, the original shared library and its
25113 replacement must have the same @code{SONAME} and be binary-compatible.
25115 The @option{--no-grafts} command-line option allows you to forcefully
25116 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
25120 guix build bash --no-grafts
25124 returns the store file name of the original Bash, whereas:
25131 returns the store file name of the ``fixed'', replacement Bash. This
25132 allows you to distinguish between the two variants of Bash.
25134 To verify which Bash your whole profile refers to, you can run
25135 (@pxref{Invoking guix gc}):
25138 guix gc -R `readlink -f ~/.guix-profile` | grep bash
25142 @dots{} and compare the store file names that you get with those above.
25143 Likewise for a complete Guix system generation:
25146 guix gc -R `guix system build my-config.scm` | grep bash
25149 Lastly, to check which Bash running processes are using, you can use the
25150 @command{lsof} command:
25153 lsof | grep /gnu/store/.*bash
25157 @node Bootstrapping
25158 @chapter Bootstrapping
25160 @c Adapted from the ELS 2013 paper.
25162 @cindex bootstrapping
25164 Bootstrapping in our context refers to how the distribution gets built
25165 ``from nothing''. Remember that the build environment of a derivation
25166 contains nothing but its declared inputs (@pxref{Introduction}). So
25167 there's an obvious chicken-and-egg problem: how does the first package
25168 get built? How does the first compiler get compiled? Note that this is
25169 a question of interest only to the curious hacker, not to the regular
25170 user, so you can shamelessly skip this section if you consider yourself
25171 a ``regular user''.
25173 @cindex bootstrap binaries
25174 The GNU system is primarily made of C code, with libc at its core. The
25175 GNU build system itself assumes the availability of a Bourne shell and
25176 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
25177 `grep'. Furthermore, build programs---programs that run
25178 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
25179 (@pxref{Derivations}). Consequently, to be able to build anything at
25180 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
25181 Binutils, libc, and the other packages mentioned above---the
25182 @dfn{bootstrap binaries}.
25184 These bootstrap binaries are ``taken for granted'', though we can also
25185 re-create them if needed (more on that later).
25187 @unnumberedsec Preparing to Use the Bootstrap Binaries
25189 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
25190 @c large image, it's hard to scroll. Oh well.
25191 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
25193 The figure above shows the very beginning of the dependency graph of the
25194 distribution, corresponding to the package definitions of the @code{(gnu
25195 packages bootstrap)} module. A similar figure can be generated with
25196 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
25199 guix graph -t derivation \
25200 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
25204 At this level of detail, things are
25205 slightly complex. First, Guile itself consists of an ELF executable,
25206 along with many source and compiled Scheme files that are dynamically
25207 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
25208 tarball shown in this graph. This tarball is part of Guix's ``source''
25209 distribution, and gets inserted into the store with @code{add-to-store}
25210 (@pxref{The Store}).
25212 But how do we write a derivation that unpacks this tarball and adds it
25213 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
25214 derivation---the first one that gets built---uses @code{bash} as its
25215 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
25216 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
25217 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
25218 the Guix source distribution, whose sole purpose is to allow the Guile
25219 tarball to be unpacked.
25221 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
25222 Guile that can be used to run subsequent build programs. Its first task
25223 is to download tarballs containing the other pre-built binaries---this
25224 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
25225 @code{ftp-client.scm} are used for this purpose. The
25226 @code{module-import.drv} derivations import those modules in a directory
25227 in the store, using the original layout. The
25228 @code{module-import-compiled.drv} derivations compile those modules, and
25229 write them in an output directory with the right layout. This
25230 corresponds to the @code{#:modules} argument of
25231 @code{build-expression->derivation} (@pxref{Derivations}).
25233 Finally, the various tarballs are unpacked by the
25234 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
25235 etc., at which point we have a working C tool chain.
25238 @unnumberedsec Building the Build Tools
25240 Bootstrapping is complete when we have a full tool chain that does not
25241 depend on the pre-built bootstrap tools discussed above. This
25242 no-dependency requirement is verified by checking whether the files of
25243 the final tool chain contain references to the @file{/gnu/store}
25244 directories of the bootstrap inputs. The process that leads to this
25245 ``final'' tool chain is described by the package definitions found in
25246 the @code{(gnu packages commencement)} module.
25248 The @command{guix graph} command allows us to ``zoom out'' compared to
25249 the graph above, by looking at the level of package objects instead of
25250 individual derivations---remember that a package may translate to
25251 several derivations, typically one derivation to download its source,
25252 one to build the Guile modules it needs, and one to actually build the
25253 package from source. The command:
25256 guix graph -t bag \
25257 -e '(@@@@ (gnu packages commencement)
25258 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
25262 produces the dependency graph leading to the ``final'' C
25263 library@footnote{You may notice the @code{glibc-intermediate} label,
25264 suggesting that it is not @emph{quite} final, but as a good
25265 approximation, we will consider it final.}, depicted below.
25267 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
25269 @c See <http://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
25270 The first tool that gets built with the bootstrap binaries is
25271 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
25272 for all the following packages. From there Findutils and Diffutils get
25275 Then come the first-stage Binutils and GCC, built as pseudo cross
25276 tools---i.e., with @code{--target} equal to @code{--host}. They are
25277 used to build libc. Thanks to this cross-build trick, this libc is
25278 guaranteed not to hold any reference to the initial tool chain.
25280 From there the final Binutils and GCC (not shown above) are built.
25282 from the final Binutils, and links programs against the just-built libc.
25283 This tool chain is used to build the other packages used by Guix and by
25284 the GNU Build System: Guile, Bash, Coreutils, etc.
25286 And voilà! At this point we have the complete set of build tools that
25287 the GNU Build System expects. These are in the @code{%final-inputs}
25288 variable of the @code{(gnu packages commencement)} module, and are
25289 implicitly used by any package that uses @code{gnu-build-system}
25290 (@pxref{Build Systems, @code{gnu-build-system}}).
25293 @unnumberedsec Building the Bootstrap Binaries
25295 @cindex bootstrap binaries
25296 Because the final tool chain does not depend on the bootstrap binaries,
25297 those rarely need to be updated. Nevertheless, it is useful to have an
25298 automated way to produce them, should an update occur, and this is what
25299 the @code{(gnu packages make-bootstrap)} module provides.
25301 The following command builds the tarballs containing the bootstrap
25302 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
25303 of Coreutils and other basic command-line tools):
25306 guix build bootstrap-tarballs
25309 The generated tarballs are those that should be referred to in the
25310 @code{(gnu packages bootstrap)} module mentioned at the beginning of
25313 Still here? Then perhaps by now you've started to wonder: when do we
25314 reach a fixed point? That is an interesting question! The answer is
25315 unknown, but if you would like to investigate further (and have
25316 significant computational and storage resources to do so), then let us
25319 @unnumberedsec Reducing the Set of Bootstrap Binaries
25321 Our bootstrap binaries currently include GCC, Guile, etc. That's a lot
25322 of binary code! Why is that a problem? It's a problem because these
25323 big chunks of binary code are practically non-auditable, which makes it
25324 hard to establish what source code produced them. Every unauditable
25325 binary also leaves us vulnerable to compiler backdoors as described by
25326 Ken Thompson in the 1984 paper @emph{Reflections on Trusting Trust}.
25328 This is mitigated by the fact that our bootstrap binaries were generated
25329 from an earlier Guix revision. Nevertheless it lacks the level of
25330 transparency that we get in the rest of the package dependency graph,
25331 where Guix always gives us a source-to-binary mapping. Thus, our goal
25332 is to reduce the set of bootstrap binaries to the bare minimum.
25334 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
25335 on-going projects to do that. One of these is about replacing the
25336 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
25337 of increasing complexity, which could be built from source starting from
25338 a simple and auditable assembler. Your help is welcome!
25342 @chapter Porting to a New Platform
25344 As discussed above, the GNU distribution is self-contained, and
25345 self-containment is achieved by relying on pre-built ``bootstrap
25346 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
25347 operating system kernel, CPU architecture, and application binary
25348 interface (ABI). Thus, to port the distribution to a platform that is
25349 not yet supported, one must build those bootstrap binaries, and update
25350 the @code{(gnu packages bootstrap)} module to use them on that platform.
25352 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
25353 When everything goes well, and assuming the GNU tool chain supports the
25354 target platform, this can be as simple as running a command like this
25358 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
25361 For this to work, the @code{glibc-dynamic-linker} procedure in
25362 @code{(gnu packages bootstrap)} must be augmented to return the right
25363 file name for libc's dynamic linker on that platform; likewise,
25364 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
25365 taught about the new platform.
25367 Once these are built, the @code{(gnu packages bootstrap)} module needs
25368 to be updated to refer to these binaries on the target platform. That
25369 is, the hashes and URLs of the bootstrap tarballs for the new platform
25370 must be added alongside those of the currently supported platforms. The
25371 bootstrap Guile tarball is treated specially: it is expected to be
25372 available locally, and @file{gnu/local.mk} has rules to download it for
25373 the supported architectures; a rule for the new platform must be added
25376 In practice, there may be some complications. First, it may be that the
25377 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
25378 above) is not recognized by all the GNU tools. Typically, glibc
25379 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
25380 configure flag (see @code{gcc.scm} for examples of how to handle this).
25381 Second, some of the required packages could fail to build for that
25382 platform. Lastly, the generated binaries could be broken for some
25385 @c *********************************************************************
25386 @include contributing.texi
25388 @c *********************************************************************
25389 @node Acknowledgments
25390 @chapter Acknowledgments
25392 Guix is based on the @uref{http://nixos.org/nix/, Nix package manager},
25393 which was designed and
25394 implemented by Eelco Dolstra, with contributions from other people (see
25395 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
25396 management, and promoted unprecedented features, such as transactional
25397 package upgrades and rollbacks, per-user profiles, and referentially
25398 transparent build processes. Without this work, Guix would not exist.
25400 The Nix-based software distributions, Nixpkgs and NixOS, have also been
25401 an inspiration for Guix.
25403 GNU@tie{}Guix itself is a collective work with contributions from a
25404 number of people. See the @file{AUTHORS} file in Guix for more
25405 information on these fine people. The @file{THANKS} file lists people
25406 who have helped by reporting bugs, taking care of the infrastructure,
25407 providing artwork and themes, making suggestions, and more---thank you!
25410 @c *********************************************************************
25411 @node GNU Free Documentation License
25412 @appendix GNU Free Documentation License
25413 @cindex license, GNU Free Documentation License
25414 @include fdl-1.3.texi
25416 @c *********************************************************************
25417 @node Concept Index
25418 @unnumbered Concept Index
25421 @node Programming Index
25422 @unnumbered Programming Index
25423 @syncodeindex tp fn
25424 @syncodeindex vr fn
25429 @c Local Variables:
25430 @c ispell-local-dictionary: "american";